Researchers hope to make mosquito 'flying vaccinator': AFP

TOKYO — Japanese researchers hope one day to turn blood-sucking mosquitoes into deliverers of vaccines that could instead inoculate millions for free.
A new study shows real promise for turning the reviled insects into heroes by genetically modifying them to make them "flying vaccinators", according to scientists at Jichi Medical University north of Tokyo.
The researchers have already genetically modified a mosquito species so that its saliva contains a protein that acts as a vaccine against leishmaniasis, a sandfly-borne disease that triggers terrible skin sores and can be fatal.
The team confirmed that mice bitten by the transgenic mosquito developed an antibody to the disease, meaning they had built up immunity, said Shigeto Yoshida, the associate professor who has led the research.
Similarly the mosquitoes could be used to help combat malaria, perhaps a decade from now, said the malaria expert.
"What's good is that they don't charge you for vaccinations," Yoshida told AFP by telephone on Wednesday.
"You would be vaccinated without even noticing. You wouldn't need any drug and you wouldn't need to show up at a designated place for mass vaccinations."
Repeat bites would only strengthen the immunity, he said.
For now a problem is that no effective vaccine exists, because malaria's antigen, which triggers immune reactions, changes frequently.
However, Yoshida expects science will come up with a solution, and that the transgenic mosquito will ultimately help rid the developing world of a deadly scourge.
Nearly one million people die each year from malaria -- most of them children -- predominantly in Africa and Asia, according to the World Health Organization.
There are several anti-malarial drugs, none of them universally effective, and a treatment, called artemisinin.
"The treatment works but it is beyond the reach of people who need to worry about food for tomorrow. They just can't afford it," Yoshida said. "Malaria is a disease closely linked to poverty. A flying vaccinator matters a lot."
Yoshida conceded the new approach could raise ethical questions about carrying out vaccinations without informed consent.
"Technically speaking I believe it's a matter of 10 years or so, but it's a different issue whether society would accept it," he said.
Another problem is that the vaccinator mosquito may still pick up and spread the infected blood of a malaria-positive person.
Yoshida's team is hoping it can tackle this problem, by also developing a mosquito that kills malaria parasites inside its own body. AFP

Chemical in Bananas Identified as Potent Inhibitor of HIV Infection

ScienceDaily (Mar. 16, 2010) — A potent new inhibitor of HIV, derived from bananas, may open the door to new treatments to prevent sexual transmission of HIV, according to a newly published University of Michigan Medical School study.

Scientists have an emerging interest in lectins, naturally occurring chemicals in plants, because of their ability to halt the chain of reaction that leads to a variety of infections.
In laboratory tests, BanLec, the lectin found in bananas, was as potent as two current anti-HIV drugs. Based on the findings published March 19 in the Journal of Biological Chemistry, BanLec may become a less expensive new component of applied vaginal microbicides, researchers say.
New ways of stopping the spread of the HIV are vitally needed. The rate of new infections of HIV is outpacing the rate of new individuals getting anti-retroviral drugs by 2.5 to1, and at present it appears an effective vaccine is years away.

"HIV is still rampant in the U.S. and the explosion in poorer countries continues to be a bad problem because of tremendous human suffering and the cost of treating it," says study senior author David Marvovitz, M.D., professor of internal medicine at the U-M Medical School.
Although condom use is quite effective, condoms are most successful in preventing infection if used consistently and correctly, which is often not the case.
"That's particularly true in developing countries where women have little control over sexual encounters so development of a long-lasting, self-applied microbicide is very attractive," Markovitz says.
Some of the most promising compounds for inhibiting vaginal and rectal HIV transmission are agents that block HIV prior to integration into its target cell.
The new research describes the complex actions of lectins and their ability to outsmart HIV. Lectins are sugar-binding proteins. They can identify foreign invaders, like a virus, and attach themselves to the pathogen.
The U-M team discovered BanLec, the lectin in bananas, can inhibit HIV infection by binding to the sugar-rich HIV-1 envelope protein, gp120, and blocking its entry to the body.
Co-authors Erwin J. Goldstein, Ph.D., professor emeritus of biological chemistry at U-M and Harry C. Winter, Ph.D., research assistant professor in biological chemistry at U-M, developed the biopurification method to isolate BanLec from bananas. Following their work, the U-M team discovered BanLec is an effective anti-HIV lectin and is similar in potency to T-20 and maraviroc, two anti-HIV drugs currently in clinical use.
Yet therapies using BanLec could be cheaper to create than current anti-retroviral medications which use synthetically produced components, plus BanLec may provide a wider range of protection, researchers say.
"The problem with some HIV drugs is that the virus can mutate and become resistant, but that's much harder to do in the presence of lectins," says lead author Michael D. Swanson, a doctoral student in the graduate program in immunology at the University of Michigan Medical School.
"Lectins can bind to the sugars found on different spots of the HIV-1 envelope, and presumably it will take multiple mutations for the virus to get around them," he says.
Swanson is developing a process to molecularly alter BanLec to enhance its potential clinical utility. Clinical use is considered years away but researchers believe it could be used alone or with other anti-HIV drugs as a vaginal microbicide that prevents HIV infection.
Authors say even modest success could save millions of lives. Other investigators have estimated that 20 percent coverage with a microbicide that is only 60 percent effective against HIV may prevent up to 2.5 million HIV infections in three years.

Good Friends, Rather Than Close Family Ties, Help You Live Longer In Older Age

ScienceDaily (June 16, 2005) — A network of good friends, rather than close family ties, helps you live longer in older age, suggests research in the Journal of Epidemiology and Community Health.

The research team drew on data from the Australian Longitudinal Study of Aging (ALSA), which began in 1992 in Adelaide, South Australia. The study aimed to assess how economic, social, behavioural and environmental factors affected the health and wellbeing of people aged 70 and upwards.
In total, almost 1500 people were asked how much personal and phone contact they had with their various social networks, including children, relatives, friends, and confidants.
Survival was monitored over 10 years. The group was monitored annually for the first four years of the study and then at approximately three yearly intervals.
The research team also considered the impact of factors likely to influence survival rates, such as socioeconomic status, health, and lifestyle.
Close contact with children and relatives had little impact on survival rates over the 10 years. But a strong network of friends and confidants significantly improved the chances of survival over that period.
Those with the strongest network of friends and confidants lived longer than those with the fewest friends/confidants.
The beneficial effects on survival persisted across the decade, irrespective of other profound changes in individuals' lives, including the death of a spouse or close family members, and the relocation of friends to other parts of the country.
The authors speculate that friends may influence health behaviours, such as smoking and drinking, or seeking medical help for troubling symptoms. Friends may also have important effects on mood, self esteem, and coping mechanisms in times of difficulty.
An accompanying editorial suggests that feeling connected to others may provide meaning and purpose that is not only essential to the human condition, but also to longevity, conferring a positive physiological effect on the body in the same way that stress confers a negative effect.

Genetics Of Popularity: Genetic Influence In Social Networks Identified

ScienceDaily (Jan. 27, 2009) — Can't help being the life of the party? Maybe you were just born that way. Researchers from Harvard University and the University of California, San Diego have found that our place in a social network is influenced in part by our genes, according to new findings published in the Proceedings of the National Academy of Sciences.

This is the first study to examine the inherited characteristics of social networks and to establish a genetic role in the formation and configuration of these networks.
The research was conducted by Nicholas Christakis of Harvard, who is professor of sociology in the Faculty of Arts and Sciences and professor of medical sociology at Harvard Medical School, Christopher Dawes and James Fowler, both of UC San Diego.
"We were able to show that our particular location in vast social networks has a genetic basis," says Christakis. "In fact, the beautiful and complicated pattern of human connection depends on our genes to a significant measure."
While it might be expected that genes affect personality, these findings go further, and illustrate a genetic influence on the structure and formation of an individual's social group.
The researchers found that popularity, or the number of times an individual was named as a friend, and the likelihood that those friends know one another, were both strongly heritable. Additionally, location within the network, or the tendency to be at the center or on the edges of the group, was also genetically linked. However, the researchers were surprised to learn that the number of people named as a friend by an individual did not appear to be inherited.
The study included national data (from the National Longitudinal Study of Adolescent Health) for the social networks of 1,110 adolescent twins, both fraternal and identical. The researchers compared the social networks of the identical twins to those of the fraternal twins, and found greater similarity between the identical twins' social network structure than the fraternal twins' networks.
There may be an evolutionary explanation for this genetic influence and the tendency for some people to be at the center while others are at the edges of the group, according to the researchers. If a deadly germ is spreading through a community, individuals at the edges are least likely to be exposed. However, to gain access to important information about a food source, being in the center of the group has a distinct benefit.
"One of the things that the study tells us is that social networks are likely to be a fundamental part of our genetic heritage," says Fowler, associate professor of political science at UC San Diego. "It may be that natural selection is acting on not just things like whether or not we can resist the common cold, but also who it is that we are going to come into contact with."
The findings also illuminate a previously unknown limitation of existing social network models, which had assumed that all members behave as interchangeable cogs. To address these intrinsic differences in human beings that contribute to the formation of social networks, the researchers have created a new mathematical model, called the "attract and introduce" model, which is also explained in this paper and supports the genetic variation of members.
This model creates networks that very closely simulate actual human social networks, and using this model, they found that when someone was placed in any virtual network, they gravitated towards the same place within the network.
Because both health behaviors and germs spread through social networks, understanding how contagions flow through social networks has the potential to improve strategies for addressing public health concerns such as obesity or the flu.
"I think that going forward, we are going to find that social networks are a critical conduit between our genes and important health outcomes," says Fowler.
Fowler and Christakis have also published on other aspects of social networks, such as the spread of obesity, smoking, and happiness.
The research was funded by the National Institute on Aging and the National Science Foundation.

Sleep Deprivation Influences Drug Use in Teens' Social Networks, Study Finds

ScienceDaily (Mar. 20, 2010) — Recent studies have shown that behaviors such as happiness, obesity, smoking and altruism are "contagious" within adult social networks. In other words, your behavior not only influences your friends, but also their friends and so on. Researchers at the University of California, San Diego and Harvard University have taken this a step farther and found that the spread of one behavior in social networks -- in this case, poor sleep patterns -- influences the spread of another behavior, adolescent drug use.


The study, led by Sara C. Mednick, PhD, assistant professor of psychiatry at the University of California, San Diego School of Medicine and the VA San Diego Healthcare System, will be published March 19 in PLoS ONE.
"This is our first investigation of the spread of illegal drug use in social networks," said Mednick. "We believe it is also the first study in any age population on the spread of sleep behaviors through social networks."
Using social network data from the National Longitudinal Study of Adolescent Health, Mednick and her colleagues James H. Fowler, UCSD Department of Political Science and Nicholas A. Christakis, Harvard Medical School, mapped the social networks of 8,349 adolescents in grades 7 through 12. They found clusters of poor sleep behavior and marijuana use that extended up to four degrees of separation (to one's friends' friends' friends' friends) in the social network.

Another novel network effect that they discovered was that teens who are at the center of the network are at greater risk of poor sleep, which in turn means they are more likely to use marijuana -- putting them at the crossroads of two behaviors increases a teenager's vulnerability.
Contrary to the general assumption that drug use has a negative effect on sleep, the researchers also found that sleep loss is likely to drive adolescents to use drugs -- the less they sleep the more likely their friends are to sleep poorly and use marijuana.
"Our behaviors are connected to each other and we need to start thinking about how one behavior affects our lives on many levels," said Mednick. "Therefore, when parents, schools and law enforcement want to look for ways to influence one outcome, such as drug use, our research suggests that targeting another behavior, like sleep, may have a positive influence. They should be promoting healthy sleep habits that eliminate behaviors which interfere with sleep: take the TV out of the child's bedroom, limit computer and phone usage to daytime and early evening hours, and promote napping."
The research was funded by the National Institute of Mental Health, National Institute on Aging and National Institute of Child Health and Human Development.
Sciencedaily.com

Meal Planning a Key to Weight Loss

By Susan Brady

While there are many good weight loss programs out there, the biggest problem people encounter is actually staying on their diet of choice. Support groups, community forums, online weight trackers, trainers at your gym are but a few of the factors that have an effect on how well you do on a diet, but the food and nutrition aspect is foremost and requires a bit of planning. Without it, you are destined to fail. So get off the procrastination wagon, start planning your meals, and give yourself a head start with your weight loss.
The best diet in the world won’t work for you if it involves eating foods you dislike. With a food plan, you are in control. The details of the plan itself are entirely up to you. It’s possible to construct a diet that consists of foods you enjoy, cooked in a manner acceptable to you, with preparation time that fits your lifestyle, at a cost that fits your budget. Your plan may involve eating the same menu everyday. This method eliminates stress because it eliminates the need to constantly count calories. You can spend an hour or two finding recipes that work for you and stay within your allotted calorie (or point or carb) count and devie a shopping list. You might plan two or three different options for each meal so that you will have, for example, one of three breakfast menus you can choose from on any given day. It can be both fun and challenging to plan well-balanced, nutritious meals that fit your lifestyle and please your palate. You can also get help from the hundreds of cookbooks that are published each year. (The library is also a good source for finding cookbooks that match your dietary restrictions.)If eating the same menus day after day is unappealing, you can try one of the numerous successful diet plans; or you may want to join a diet club such as Weight Watchers or TOPS (Take off Pounds Sensibly). Or you may want to participate in a weight control class sponsored by your health plan. Going with a nationally published diet offers the benefit of a diet that is already balanced, calorie controlled, and in place. The same is true with the diet clubs; additionally some people benefit from the group sessions that provide nutritional education and motivational support. Many people find the weekly weigh-ins, at the diet clubs, help them stay on track.
healthnews.com

Morning Sickness, symptoms, Treatment and Prevention

Definition of Morning Sickness

Pregnancy sickness or "morning sickness" is nausea, with or without vomiting, during pregnancy.

Description of Morning Sickness

Morning sickness may occur at any time of the day, especially when the stomach is empty. It affects about one-third to one-half of all expectant women and is most common during the first three months of pregnancy. Some expectant mothers will not experience it until well into the second trimester and a few may never experience morning sickness throughout the pregnancy.
If the nausea and vomiting persist or worsen the woman may have a rare condition called hyperemesis gravidarum. This exaggerated form of morning sickness occurs in fewer than 1 in 250 pregnancies. The symptoms of this condition are frequent and severe nausea and vomiting, inability to “keep anything down," weight loss, signs of dehydration (severe thirst, dry lips and tongue, confusion, rapid breathing and an increased heart rate) and starvation. This condition is treated by immediate hospitalization with intravenous hydration until the woman can tolerate foods and liquids by mouth.

Causes and Risk Factors of Morning Sickness

No one knows for sure the causes of morning sickness. It is known that the neurologic “control” for nausea and vomiting is located in the brain stem. A myriad of physical reasons why this area may be overstimulated during pregnancy have been suggested, including the high level of the pregnancy hormone HCG in the blood in the first trimester, the rapid stretching of the uterine muscles, the relative relaxation of the muscle tissue in the digestive tract (which makes digestion less efficient) and the excess acid in the stomach caused by not eating or by eating the wrong foods.
Emotional factors also influence morning sickness. Morning sickness is unknown in some more primitive societies where lifestyles are simpler, more relaxed and less demanding.
There is evidence that shows that some women with unwanted, unplanned pregnancies suffer debilitating nausea and vomiting, yet experience no morning sickness at all in pregnancies they are happy about. The fact that morning sickness is more common and tends to be more severe in first pregnancies supports the concept that both physical and emotional factors are involved. Physically, the novice pregnant individual is less prepared for the onslaught of hormones and other changes than one who has been through it before.

Treatment of Morning Sickness

There is no currently approved medication available for morning sickness, but the doctor may suggest trying these medication-based treatments if the methods mentioned are not helping:
antacids that are low in sodium and available over-the-counter
vitamin B6
sugar solution that is available over-the-counter
acupressure wristbands (used for seasickness)
antihistamine (prescribed by a doctor) only if the following concerns are evident: persistent vomiting, insufficient weight gain and signs of dehydration
Please talk to your doctor before taking any medication.

Self CareThere are many self care methods of alleviating the symptoms and minimizing the effects of morning sickness. These include:
Eat four to six small meals per day, instead of three heavy meals. An empty stomach and low blood sugar, resulting from long stretches between meals, can trigger nausea, as can eating too much at one meal.
Eat crackers or dry toast 20 to 30 minutes before getting up in the morning, while slightly propped up in bed. Bland foods such as crackers or pretzels may help at any time of day when you feel nauseated.
Minimize the intake of fluids with meals. Instead drink small amounts of fluids frequently between meals.
Eat a diet high in protein and complex carbohydrates, both of which fight nausea.
Drink plenty of fluids, especially if you are losing them through vomiting. If they are easier to get down than solids when your stomach is upset, use them to get your nutrients.
Herbal teas, fruit juices and popsicles are helpful in combating the nauseated feeling.
Take a prenatal vitamin supplement to compensate for nutrients missed through not eating.
Avoid the sight, smell, and taste of foods that make you queasy.
Eat before nausea strikes. Food will be easier to get down and may prevent an attack.
Eat in bed to avoid an empty stomach and to keep the blood sugar on an even keel.
Before you go to bed at night, have a snack that is high in protein and complex carbohydrates.
Get extra sleep and relaxation. Both emotional and physical fatigue can exacerbate morning sickness.
Greet the morning in slow motion – rushing tends to aggravate nausea.
Brush teeth with a toothpaste that does not increase the queasiness and rinse the mouth with a good rinser after each bout of vomiting, as well as after each meal. Not only will this keep the mouth fresh and reduce nausea, it will also decrease the risk of damage to teeth and gums that can occur when bacteria starts working on the regurgitated material in the mouth.
Minimize stress. Morning sickness is more common among women who are under a great deal of stress, either at work or home.

Start running and watch your brain grow, say scientists

The health benefits of a regular run have long been known, but scientists have never understood the curious ability of exercise to boost brain power.
Now researchers think they have the answer. Neuroscientists at Cambridge University have shown that running stimulates the brain to grow fresh grey matter and it has a big impact on mental ability.
A few days of running led to the growth of hundreds of thousands of new brain cells that improved the ability to recall memories without confusing them, a skill that is crucial for learning and other cognitive tasks, researchers said.
The new brain cells appeared in a region that is linked to the formation and recollection of memories. The work reveals why jogging and other aerobic exercise can improve memory and learning, and potentially slow down the deterioration of mental ability that happens with old age.
"We know exercise can be good for healthy brain function, but this work provides us with a mechanism for the effect," said Timothy Bussey, a behavioural neuroscientist at Cambridge and a senior author on the study. The research builds on a growing body of work that suggests exercise plays a vital role in keeping the brain healthy by encouraging the growth of fresh brain cells.
Previous studies have shown that "neurogenesis" is limited in people with depression, but that their symptoms can improve if they exercise regularly. Some antidepressant drugs work by encouraging the growth of new brain cells.
Scientists are unsure why exercise triggers the growth of grey matter, but it may be linked to increased blood flow or higher levels of hormones that are released while exercising. Exercise might also reduce stress, which inhibits new brain cells through a hormone called cortisol.
The Cambridge researchers joined forces with colleagues at the US National Institute on Ageing in Maryland to investigate the effect of running.
They studied two groups of mice, one of which had unlimited access to a running wheel throughout. The other mice formed a control group. In a brief training session, the mice were put in front of a computer screen that displayed two identical squares side by side. If they nudged the one on the left with their nose they received a sugar pellet reward. If they nudged the one on the right, they got nothing.
After training the mice went on to do the memory test. The more they nudged the correct square, the better they scored. At the start of the test, the squares were 30cm apart, but got closer and closer together until they were almost touching. This part of the experiment was designed to test how good the mice were at separating two very similar memories. The human equivalent could be remembering what a person had for dinner yesterday and the day before, or where they parked on different trips to the supermarket.
The running mice clocked up an average of 15 miles (24km) a day. Their scores in the memory test were nearly twice as high as those of the control group. The greatest improvement was seen in the later stages of the experiment, when the two squares were so close they nearly touched, according to a report in the Proceedings of the National Academy of Sciences.
"At this stage of the experiment, the two memories the mice are forming of the squares are very similar. It is when they have to distinguish between the two that these new brain cells really make a difference," Bussey said.
The sedentary mice got steadily worse at the test because their memories became too similar to separate.
The scientists also tried to wrongfoot the mice by switching the square that produced a food reward. The running mice were quicker to catch on when scientists changed them around.
Brain tissue taken from the rodents showed that the running mice had grown fresh grey matter during the experiment. Tissue samples from the dentate gyrus part of the brain revealed on average 6,000 new brain cells in every cubic millimetre. The dentate gyrus is part of the hippocampus, one of the few regions of the adult brain that can grow fresh brain cells.
The Guardian

ICSI (Intra Cytoplasmic Sperm Injection)

What is ICSI?

ICSI is an acronym for intracytoplasmic sperm injection - which is a fancy way of saying "inject sperm in the middle of the egg". ICSI is a very effective method to fertilize eggs in the IVF lab after they have been retrieved from the female.
* IVF with ICSI involves the use of specialized micromanipulation tools and equipment and inverted microscopes that enable embryologists to select and pick up individual sperm in a specially designed ICSI needle.


* Then the needle is carefully advanced through the outer shell of the egg and the egg membrane - and the sperm is injected into the inner part (cytoplasm) of the egg.

* This will usually result in normal fertilization in about 75-85% of eggs injected with sperm.

* However, first the woman must be stimulated with medications and have an egg retrieval procedure so we can obtain several eggs for in vitro fertilization and ICSI.
Who should be treated with intracytoplasmic sperm injection?

There is no "standard of care" in this field of medicine regarding which cases should have the ICSI procedure and which should not.

Some clinics use it only for severe male factor infertility, and some use it on every case. The large majority of IVF clinics are somewhere in the middle of these 2 extremes.

Our thinking about ICSI has changed over time, and we are now doing more ICSI (as a percentage of total cases) than we were 10-12 years ago. As we learn more about methods to help couples conceive, our thinking will continue to evolve.
Common reasons used for performing ICSI

ICSI fertilization procedure in progressNeedle with a sperm inside is advanced to the leftShell of embryo has already been penetrated by needleMembrane of egg (oolemma) is stretching and about to breakSperm head visible at tip of needle

1. Severe male factor infertility that do not want donor sperm insemination.

2. Couples with infertility with:
* Sperm concentrations of less than 15-20 million per milliliter
* Sperm motility less than 35%
* Very poor sperm morphology (subjective - specific cutoff value is debatable)

3. Having previous IVF with no fertilization - or a low rate of fertilization (low percentage of mature eggs that were normally fertilized).

4. Sometimes it is used for couples that have a low yield of eggs at egg retrieval. In this scenario, ICSI is being used to try to get a higher percentage of eggs fertilized than with conventional insemination of the eggs (mixing eggs and sperm together).

How is ICSI performed?

1. The mature egg is held with a specialized holding pipette.

2. A very delicate, sharp and hollow needle is used to immobilize and pick up a single sperm.

3. This needle is then carefully inserted through the zona (shell of the egg) and in to the center (cytoplasm) of the egg.

4. The sperm is injected in the cytoplasm and the needle is removed.

5. The eggs are checked the next morning for evidence of normal fertilization.

Fertilization and pregnancy success rates with ICSI

Fertilization rates for ICSI: Most IVF programs see that about 70-85% of eggs injected using ICSI become fertilized. We call this the fertilization rate, which is different from the pregnancy success rate.

Pregnancy success rates for in vitro fertilization procedures with ICSI have been shown in some studies to be higher than for IVF without ICSI. This is because in many of the cases needing ICSI the female is relatively young and fertile (good egg quantity and quality) as compared to some of the women having IVF for other reasons.

In other words, the average egg quantity and quality tends to be better in ICSI cases (male factor cases) because it is less likely that there is a problem with the eggs - as compared to cases with unexplained infertility. Some unexplained cases have reduced egg quantity and/or quality - which lowers the chances for a successful IVF outcome.

IVF with ICSI success rates vary according to the specifics of the individual case, the ICSI technique used, the skill of the individual performing the procedure, the overall quality of the laboratory, the quality of the eggs, and the embryo transfer skills of the infertility specialist physician.

Sometimes IVF with ICSI is done for "egg factor" cases - low ovarian reserve situations. This is when there is either a low number, or low "quality"of eggs (or both). In such cases, ICSI fertilization and pregnancy success rates tend to be lower.

* This is because the main determinant of IVF success is the quality of the embryos.

* The quality of the eggs is a crucial factor determining quality and viability of embryos.

THE UNDESCENDED TESTICLE

What is an undescended testicle?

The testicle (testis) is responsible for the production of male hormone and also sperm. Before the child is born the testicle migrates down from high in the abdomen and passes through abdominal wall and groin to take its normal position in the scrotum. Undescended testicles are quite common. They may be present in 4% of boys at birth, and there is an even higher incidence in premature infants. Three-fourths of undescended testicles will descend within the first three months of life.

When a testicle is not in the normal scrotal location several possibilities exist:
There may never have been a testicle (congenital absence).
The testicle may have atrophied (withered away) before birth due to torsion (twist) or blockage of the testicular blood vessels.
The testicle may have descended incompletely and may lie within the inguinal canal (just above the scrotum).
The testicle may have not descended properly, but remains within the abdominal cavity.
In some children the testes may be found in the groin, but can be brought down into the scrotum during examination. These 'retractile' testicles also will be seen to descend when the child is in the bathtub. Retractile testicles are due to hyperactive muscles that temporarily pull the testicle into the groin. However, retractile testicles are not believed to injure the testicles and require no treatment.

Why should an undescended testicle be treated?

In humans, the scrotal location of the testicles keeps them cooler than the core body temperature. This lower temperature is important for the development of the testicle as well as for production of normal sperm. Studies have shown that there is an increased risk of infertility in men with a history of undescended testicles. Relocating the testicle into the scrotum may decrease the risk of fertility problems, particularly if done at an early age.

Renal Calculi

Author: Sandy Craig, MD, Adjunct Associate Professor, Department of Emergency Medicine, University of North Carolina at Chapel Hill, Carolinas Medical Center

Introduction

Background

Acute passage of a kidney stone from the renal pelvis through the ureter gives rise to pain at times so excruciating that it has been likened to the discomfort of childbirth. The often sudden, extremely painful episode of renal colic prompts more than 450,000 visits to EDs annually and places emergency physicians on the front line of management of acute nephrolithiasis. ED management is focused on excluding other serious diagnoses and providing adequate pain relief.

Pathophysiology

Most calculi arise in the kidney when urine becomes supersaturated with a salt that is capable of forming solid crystals. Symptoms arise as these calculi become impacted within the ureter as they pass toward the urinary bladder.

Frequency

United States

The lifetime prevalence of nephrolithiasis is approximately 12% for men and 7% for women in the United States, and it is rising. Recurrence rates after the first stone episode are 14%, 35%, and 52% at 1, 5, and 10 years, respectively. An increased incidence has been noted in the southeastern United States, prompting the term "stone belt" for this region of the country.¹

International

Nephrolithiasis occurs in all parts of the world, with a lower lifetime risk of 2-5% in Asia, 8-15% in the West, and 20% in Saudi Arabia.

Mortality/Morbidity

• Approximately 80-85% of stones pass spontaneously.
• Approximately 20% of patients require hospital admission because of unrelenting pain, inability to retain enteral fluids, proximal urinary tract infection (UTI), or inability to pass the stone.
• A ureteral stone associated with obstruction and upper UTI is a true urologic emergency. Complications include perinephric abscess, urosepsis, and death. Immediate involvement of the urologist is essential.

Race

• White males are affected 3-4 times more often than African American males.
• African Americans have a higher incidence of infected ureteral calculi than whites.

Sex

• The male-to-female ratio is approximately 3:1.
• Female patients have a higher incidence of infected hydronephrosis.

Age

Peak onset of symptomatic nephrolithiasis is in the third and fourth decades of life.

• Beware of the patient older than 60 years with an apparent first kidney stone. Consider the possibility of symptomatic abdominal aortic aneurysm (AAA) in the older patient, and rule out this possibility before pursuing the diagnosis of nephrolithiasis. Use bedside ultrasonography if the patient's condition is potentially unstable. CT scan is a reasonable alternative in the stable patient.
• Nephrolithiasis in children is rare; approximately 5-10 children aged 10 months to 16 years are seen annually for the condition at a typical US pediatric referral center.

Clinical

History

Most calculi originate within the kidney and proceed distally, creating various degrees of urinary obstruction as they become lodged in narrow areas, including the ureteropelvic junction, pelvic brim, and ureterovesical junction. Location and quality of pain are related to position of the stone within the urinary tract. Severity of pain is related to the degree of obstruction, presence of ureteral spasm, and presence of any associated infection.

• Stones obstructing the ureteropelvic junction may present with mild-to-severe deep flank pain without radiation to the groin, due to distension of the renal capsule.
• Stones impacted within the ureter cause abrupt, severe, colicky pain in the flank and ipsilateral lower abdomen with radiation to the testicles or the vulvar area. Intense nausea, with or without vomiting, usually is present.
• Stones lodged at the ureterovesical junction also may cause irritative voiding symptoms, such as urinary frequency and dysuria.
• Calculi that have entered the bladder are usually asymptomatic and are passed relatively easily during urination.
• Rarely, a patient reports positional urinary retention (obstruction precipitated by standing, relieved by recumbency), which is due to the ball-valve effect of a large stone located at the bladder outlet.

Physical

The classic patient with renal colic is writhing in pain, pacing about, and unable to lie still, in contrast to a patient with peritoneal irritation, who remains motionless to minimize discomfort.

• Fever is not part of the presentation of uncomplicated nephrolithiasis. If present, suspect infected hydronephrosis, pyonephrosis, or perinephric abscess.
• The most common finding in ureterolithiasis is flank tenderness due to the dilation and spasm of the ureter from transient obstruction as the stone passes from the kidney to the bladder.
• Abdominal examination usually is unremarkable. Bowel sounds may be hypoactive, a reflection of mild ileus, which is not uncommon in patients with severe, acute pain.
• In patients older than 60 years with no prior history of renal stones, the emergency physician should look carefully for physical signs of AAA (see Aneurysm, Abdominal).
• Testicles may be painful but should not be very tender and should appear normal.

Causes

The formation of the 4 basic chemical types of renal calculi is associated with more than 20 underlying etiologies. Stone analysis, together with serum and 24-hour urine metabolic evaluation, can identify an etiology in more than 95% of patients. Specific therapy can result in a remission rate of more than 80% and can decrease the individual recurrence rate by 90%. Therefore, emergency physicians should stress the importance of urologic follow-up, especially in patients with recurrent stones, solitary kidneys, or previous kidney or stone surgery and in all children.²

• Calcium stones (75%): Recent data suggest that a low-protein, low-salt diet may be preferable to a low-calcium diet in hypercalciuric stone formers for preventing stone recurrences.³ Epidemiological studies have shown that the incidence of stone disease is inversely related to the magnitude of dietary calcium intake in first-time stone formers. There is a trend in the urology community not to restrict dietary intake of calcium in recurrent stone formers. This is especially important for postmenopausal women in whom there is an increased concern for the development of osteoporosis. Calcium oxalate, calcium phosphate, and calcium urate are associated with the following disorders:
  • Hyperparathyroidism - Treated surgically or with orthophosphates if the patient is not a surgical candidate
  • Increased gut absorption of calcium - The most common identifiable cause of hypercalciuria, treated with calcium binders or thiazides plus potassium citrate
  • Renal calcium leak - Treated with thiazide diuretics
  • Renal phosphate leak - Treated with oral phosphate supplements
  • Hyperuricosuria - Treated with allopurinol, low purine diet, or alkalinizing agents such as potassium citrate
  • Hyperoxaluria - Treated with dietary oxalate restriction, oxalate binders, vitamin B-6, or orthophosphates
  • Hypocitraturia - Treated with potassium citrate
  • Hypomagnesuria - Treated with magnesium supplements
• Struvite (magnesium ammonium phosphate) stones (15%)
  • Struvite stones are associated with chronic UTI with gram-negative rods capable of splitting urea into ammonium, which combines with phosphate and magnesium. Underlying anatomical abnormalities that predispose patients to recurrent kidney infections should be sought and corrected.
  • Usual organisms include Proteus, Pseudomonas, and Klebsiella species. Escherichia coli is not capable of splitting urea and, therefore, is not associated with struvite stones.
  • UTI does not resolve until stone is removed entirely.
  • Urine pH is typically greater than 7.
• Uric acid stones (6%): These are associated with urine pH less than 5.5, high purine intake (eg, organ meats, legumes, fish, meat extracts, gravies), or malignancy (ie, rapid cell turnover). Approximately 25% of patients with uric acid stone have gout. Serum and 24-hour urine sample should be sent for creatinine and uric acid determination. If serum or urinary uric acid is elevated, the patient may be treated with allopurinol 300 mg daily. Patients with normal serum or urinary uric acid are best managed by alkali therapy alone.
• Cystine stones (2%)
  • Cystine stones arise because of an intrinsic metabolic defect resulting in failure of renal tubular reabsorption of cystine, ornithine, lysine, and arginine.
  • Urine becomes supersaturated with cystine with resultant crystal deposition.
  • These are treated with low-methionine diet (unpleasant), binders such as penicillamine or a-mercaptopropionylglycine, large urinary volumes, or alkalinizing agents. A 24-hour quantitative urinary cystine determination helps to titrate the dose of drug therapy to achieve a urinary cystine concentration of less than 300 mg/L.
• Drug-induced stone disease: A number of medications or their metabolites can precipitate in urine causing stone formation. These include indinavir; atazanavir; guaifenesin; triamterene; silicate (overuse of antacids containing magnesium silicate); and sulfa drugs including sulfasalazine, sulfadiazine, acetylsulfamethoxazole, acetylsulfasoxazole, and acetylsulfaguanidine. emedicine.com

Boost your fertility

Having difficulty getting pregnant? There are some simple ways to help nature along.

If you've been trying to start a family without success, making some simple lifestyle changes may increase your chance of conception and help to ensure a healthy pregnancy. However, there are some factors, such as age, ovulation problems, sperm disorders and damaged fallopian tubes, that you can't change.

Changes you can make

Eat well: if you're a woman, a nutritious, balanced diet will help improve your general health and wellbeing, and ensure your body is able to nourish a baby. If you're a man, healthy eating is also important for sperm production.

Choose a varied diet containing fresh fruit and vegetables, bread, potatoes, rice and other cereals (wholegrain, where possible), milk and dairy products, lean meat, fish and other sources of protein.

Being overweight or very underweight can disrupt your periods and hinder conception

Watch your weight: being overweight or very underweight can disrupt your periods and hinder conception. A woman with a body mass index (BMI) of more than 29 or less than 19 may find it more difficult to conceive.

To work out your BMI, divide your weight in kilograms by your height in metres squared (your height in metres multiplied by itself) or use our BMI calculator. Fertility treatment may not be possible for very overweight or obese women.

Drink wisely: the government advises women trying to conceive to avoid alcohol completely. Men shouldn't drink more than three or four units a day, and should avoid binge drinking to prevent damage to sperm.

Stop smoking: smoking has been linked to infertility and early menopause in women, and sperm problems in men. It also reduces the success of fertility treatments.

Be active: regular moderate exercise (such as brisk walking) for at least 30 minutes a day will help to keep you fit for conception and help to control your weight.

Exercise also reduces stress and boosts levels of endorphins, the body's own feel-good hormones.

Keep cool: for optimum sperm production, the testicles need to be a couple of degrees cooler than the rest of the body. Avoid tight underwear and jeans, and excessively hot baths and saunas.

Think about your job: occupations that involve sitting for long periods, such as long-distance lorry driving, or exposure to environmental chemicals such as paints or pesticides, may affect sperm quality. If this is an issue, discuss it with your work supervisor. Watch an exclusive video interview with Professor William Ledger.

Manage stress: stress doesn't cause infertility, but excessive anxiety can sometimes upset the menstrual cycle. Try to reduce stress levels and give yourself time to relax.

Take folic acid: all women trying for a baby should take a supplement of 400mcg of folic acid a day to help prevent birth defects such as spina bifida.

Check drugs: certain prescription drugs can reduce the chance of conception. If you're taking regular medication, talk to your doctor.

Marijuana and cocaine can affect sperm counts.
Things you can't change

Not all factors affecting fertility are within your control.
Women

For women, the following may affect conception:

Ovulation problems: sometimes, women don't ovulate (release an egg each month) or do so only occasionally.

Reasons include:

* Polycystic ovary syndrome (PCOS), in which numerous small cysts develop on the ovaries and ovulation is erratic.
* The side effects of some medications, such as anti-inflammatory painkillers, chemotherapy and radiation treatment (for example, for cancer).
* Premature ovarian failure (early menopause).
* Hormonal imbalances.


Blocked fallopian tubes: below are the most common causes of inflamed and blocked tubes.

* Sexually transmitted infections (STIs) such as chlamydia and (more rarely) gonorrhoea.
* Endometriosis, in which cells from the lining of the womb implant elsewhere, such as the ovaries.
* Pelvic inflammatory disease, which can be caused by chlamydia and other STIs.
* Previous pelvic surgery - for example, for appendicitis or peritonitis.


Women in their early 20s are about twice as likely to get pregnant as women in their late 30s

Your age: the quantity and quality of your eggs decline with age. Women in their early 20s are about twice as likely to get pregnant as women in their late 30s.

Problems in the womb: problems with the lining of the womb, such as fibroids or physical abnormalities of the womb, can prevent the successful implantation of a fertilised egg.

Other medical conditions: conditions that can affect female fertility include diabetes, epilepsy, thyroid and bowel diseases, as well as gynaecological problems such as a previous ectopic pregnancy or more than one miscarriage.
Men

Male infertility is usually caused by sperm problems. These include:

* Low sperm count (not producing enough sperm), poor sperm quality or poor motility (slow-moving sperm).
* Previous inflammation of, or injury to, the testicles. This includes inflammation caused by mumps, drug treatment, radiotherapy or sporting injuries.
* A previous bacterial infection.
* Previous surgery - for example, to correct a hernia - or undescended or twisted testicles, which can damage the tubes or impair blood flow to the testicles.
* Diabetes, medication or urinary tract surgery can cause retrograde ejaculation, when sperm travels backwards into the bladder.
* Sexual problems, such as the inability to have an erection.

Sexually Transmitted Diseases In Men (STDs)

What are STIs and how can their spread be prevented?

Sexually transmitted diseases (STDs) are infections that are transmitted during any type of sexual exposure, including intercourse (vaginal or anal), oral sex, and the sharing of sexual devices, such as vibrators. In the professional medical arena, STDs are referred to as STIs (sexually transmitted infections). This terminology is used because many infections are frequently temporary. Some STDs are infections that are transmitted by persistent and close skin-to-skin contact, including during sexual intimacy. Although treatment exists for many STDs, others currently are usually incurable, such as HIV, HPV, hepatitis B and C, and HHV-8. What is more, many infections can be present in, and be spread by, patients who do not have symptoms.

The most effective way to prevent the spread of STDs is abstinence. Alternatively, the diligent use of latex barriers, such as condoms, during vaginal or anal intercourse and oral-genital contact helps decrease the spread of many of these infections. Still, there is no guarantee that transmission will not occur. In fact, preventing the spread of STDs also depends upon appropriate counseling of at-risk individuals and the early diagnosis and treatment of those infected.

In this article, the STDs in men have been organized into three major categories: (1) STDs that are associated with genital lesions; (2) STDs that are associated with urethritis (inflammation of the urethra, the canal through which urine flows out); and (3) systemic STDs (involving various organ systems of the body). Note, however, that some of the diseases that are listed as being associated with genital lesions (for example, syphilis) or with urethritis (for example, gonorrhea) can also have systemic involvement.

Depressive disorder

Depression is a complex matter. In recent years, with burgeoning research progress, we are finding out that depression is much more common than many of us thought. At least 15% (and likely more) of women take an antidepressant during their lifetime. Depression is much more common in women than in men, but the reason for this female predominance is unclear.

Depressive disorders have been with mankind since the beginning of recorded history. In the Bible, King David, as well as Job, suffered from this affliction. Hippocrates referred to depression as melancholia, which literally means black bile. Black bile, along with blood, phlegm, and yellow bile were the four humors (fluids) that described the basic medical physiology theory of that time. Depression, also referred to as clinical depression, has been portrayed in literature and the arts for hundreds of years, but what do we mean today when we refer to a depressive disorder? In the 19th century, depression was seen as an inherited weakness of temperament. In the first half of the 20th century, Freud linked the development of depression to guilt and conflict. John Cheever, the author and a modern sufferer of depressive disorder, wrote of conflict and experiences with his parents as influencing his development of depression.

In the 1950s and '60s, depression was divided into two types, endogenous and neurotic. Endogenous means that the depression comes from within the body, perhaps of genetic origin, or comes out of nowhere. Neurotic or reactive depression has a clear environmental precipitating factor, such as the death of a spouse, or other significant loss, such as the loss of a job. In the 1970s and '80s, the focus of attention shifted from the cause of depression to its effects on the afflicted people. That is to say, whatever the cause in a particular case, what are the symptoms and impaired functions that experts can agree make up a depressive disorder? Although there is some argument even today (as in all branches of medicines), most experts agree on the following:
A depressive disorder is a syndrome (group of symptoms) that reflects a sad and/or irritable mood exceeding normal sadness or grief. More specifically, the sadness of depression is characterized by a greater intensity and duration and by more severe symptoms and functional disabilities than is normal.


Depressive signs and symptoms are characterized not only by negative thoughts, moods, and behaviors but also by specific changes in bodily functions (for example, crying spells, body aches, low energy or libido, as well as problems with eating, weight, or sleeping). The functional changes of clinical depression are often called neurovegetative signs. This means that the nervous system changes in the brain cause many physical symptoms that result in diminished participation and a decreased or increased activity level.


Certain people with depressive disorder, especially bipolar depression (manic depression), seem to have an inherited vulnerability to this condition.


Depressive disorders are a huge public-health problem, due to its affecting millions of people. About 10% of adults, up to 8% of teens and 2% of preteen children experience some kind of depressive disorder.
The statistics on the costs due to depression in the United States include huge amounts of direct costs, which are for treatment, and indirect costs, such as lost productivity and absenteeism from work or school.


Adolescents who suffer from depression are at risk for developing and maintaining obesity.


In a major medical study, depression caused significant problems in the functioning of those affected more often than did arthritis, hypertension, chronic lung disease, and diabetes, and in some ways as often as coronary artery disease.


Depression can increase the risks for developing coronary artery disease, HIV, asthma, and many other medical illnesses. Furthermore, it can increase the morbidity (illness/negative health effects) and mortality (death) from these and many other medical conditions.


Depression can coexist with virtually every other mental health illness, aggravating the status of those who suffer the combination of both depression and the other mental illness.


Depression in the elderly tends to be chronic, has a low rate of recovery, and is often undertreated. This is of particular concern given that elderly men, particularly elderly white men have the highest suicide rate.
Depression is usually first identified in a primary-care setting, not in a mental health practitioner's office. Moreover, it often assumes various disguises, which causes depression to be frequently underdiagnosed.


In spite of clear research evidence and clinical guidelines regarding therapy, depression is often undertreated. Hopefully, this situation can change for the better.


For full recovery from a mood disorder, regardless of whether there is a precipitating factor or it seems to come out of the blue, treatment with medication and/or electroconvulsive therapy (ECT) (see discussion below) and psychotherapy are necessary. Medicinenet.com

Swine Flu -- know about

Swine flu (swine influenza) is a respiratory disease caused by viruses (influenza viruses) that infect the respiratory tract of pigs and result in nasal secretions, a barking-like cough, decreased appetite, and listless behavior. Swine flu produces most of the same symptoms in pigs as human flu produces in people. Swine flu can last about one to two weeks in pigs that survive. Swine influenza virus was first isolated from pigs in 1930 in the U.S. and has been recognized by pork producers and veterinarians to cause infections in pigs worldwide. In a number of instances, people have developed the swine flu infection when they are closely associated with pigs (for example, farmers, pork processors), and likewise, pig populations have occasionally been infected with the human flu infection. In most instances, the cross-species infections (swine virus to man; human flu virus to pigs) have remained in local areas and have not caused national or worldwide infections in either pigs or humans. Unfortunately, this cross-species situation with influenza viruses has had the potential to change. Investigators think the 2009 swine flu strain, first seen in Mexico, should be termed novel H1N1 flu since it is mainly found infecting people and exhibits two main surface antigens, H1 (hemagglutinin type 1) and N1 (neuraminidase type1). Recent investigations show the eight RNA strands from novel H1N1 flu have one strand derived from human flu strains, two from avian (bird) strains, and five from swine strains.

Why is swine flu (H1N1) now infecting humans?


Many researchers now consider that two main series of events can lead to swine flu (and also avian or bird flu) becoming a major cause for influenza illness in humans.

First, the influenza viruses (types A, B, C) are enveloped RNA viruses with a segmented genome; this means the viral RNA genetic code is not a single strand of RNA but exists as eight different RNA segments in the influenza viruses. A human (or bird) influenza virus can infect a pig respiratory cell at the same time as a swine influenza virus; some of the replicating RNA strands from the human virus can get mistakenly enclosed inside the enveloped swine influenza virus. For example, one cell could contain eight swine flu and eight human flu RNA segments. The total number of RNA types in one cell would be 16; four swine and four human flu RNA segments could be incorporated into one particle, making a viable eight RNA segmented flu virus from the 16 available segment types. Various combinations of RNA segments can result in a new subtype of virus (known as antigenic shift) that may have the ability to preferentially infect humans but still show characteristics unique to the swine influenza virus (see Figure 1). It is even possible to include RNA strands from birds, swine, and human influenza viruses into one virus if a cell becomes infected with all three types of influenza (for example, two bird flu, three swine flu, and three human flu RNA segments to produce a viable eight-segment new type of flu viral genome). Formation of a new viral type is considered to be antigenic shift; small changes in an individual RNA segment in flu viruses are termed antigenic drift and result in minor changes in the virus. However, these can accumulate over time to produce enough minor changes that cumulatively change the virus' antigenic makeup over time (usually years).

Second, pigs can play a unique role as an intermediary host to new flu types because pig respiratory cells can be infected directly with bird, human, and other mammalian flu viruses. Consequently, pig respiratory cells are able to be infected with many types of flu and can function as a "mixing pot" for flu RNA segments (see Figure 1). Bird flu viruses, which usually infect the gastrointestinal cells of many bird species, are shed in bird feces. Pigs can pick these viruses up from the environment and seem to be the major way that bird flu virus RNA segments enter the mammalian flu virus population.

Infertility

Also called: Sterility

Infertility means not being able to become pregnant after a year of trying. If a woman keeps having miscarriages, it is also called infertility. Lots of couples have infertility problems. About a third of the time, infertility can be traced to the woman. In another third of cases, it is because of the man. The rest of the time, it is because of both partners or no cause is found.

If you think you might be infertile, tell your doctor. For a man, a first step is often a sperm test. For women, doctors run tests to see if their ovaries work properly. Women in their 30s who have been trying to get pregnant for six months should consider seeking help. A woman's chances of having a baby drop rapidly every year after age 30.

Drugs or surgery are common treatments. Happily, two-thirds of couples treated for infertility go on to have babies.

National Women's Health Information Center

Eye test may detect Alzheimer's

A simple eye test might be able to detect Alzheimer's and other diseases before symptoms develop, according to UK scientists.

The technique uses fluorescent markers which attach to dying cells which can be seen in the retina and give an early indication of brain cell death.

The research has been carried out on mice, but human trials are planned.

Scientists from University College London hope this could lead to a high street opticians test for the disease.

The research, which is published in the journal, Cell Death and Disease, could enable scientists to overcome the difficulty of investigating what is happening inside the brains of those with Alzheimer's.

They currently have to rely on expensive MRI scans or post-mortems.

Fluorescent dye

This new technique enables scientists to track the progress of brain disease by looking at dying cells in the retina.

The cells show up as green dots because they absorb the fluorescent dye.

"These findings have the potential to transform the way we diagnose Alzheimer's"

Rebecca Wood, Alzheimer's Research Trust

The research has so far been carried out on mice, but the team is optimistic that the technique can be translated to humans.

Professor Francesca Coredeiro, lead author from University College London Institute of Ophthalmology said: "Few people realise that the retina is a direct, albeit thin, extension of the brain.

"It is entirely possible that in the future a visit to a high-street optician to check on your eyesight will also be a check on the state of your brain."

"I hope that screening for Alzheimer's will be available on the high street within five years."

She said the research could help scientists to see how the disease is progressing by comparing retinal cell death a few weeks apart.

"Currently, the biggest obstacle to research into new treatments for neurodegenerative diseases is the lack of a technique where the brain's response to new treatments can be directly assessed - this technique could potentially help overcome that."

Patient trials

The first patient trials to assess the technique for the eye disease will begin later this year.

Rebecca Wood, Chief Executive of the Alzheimer's Research Trust, said: "These findings have the potential to transform the way we diagnose Alzheimer's, greatly enhancing efforts to develop new treatments and cures.

"If we spot Alzheimer's in its earliest stages, we may be able to treat and reverse the progression of the disease as new treatments are developed.

"Dementia scientists currently lack a way of assessing the brain's responses to new treatments in real time; this technique may help overcome that obstacle.

"700,000 people in the UK live with Alzheimer's and other dementias, and that number is set to double within a generation unless scientists make rapid progress in their race for a cure."

Dr Susanne Sorensen from the Alzheimer's Society also welcomed the research, but stressed much more research was needed to see if the technique could indeed be used to diagnose the disease, or monitor the effects of drugs under development. BBC Health 

High & Low Blood Pressure

Human body possesses closed system of blood circulation which means all the blood is within vessels. Vessels are largely of two types, 1. Arteries and 2. Veins Arteries are those vessels that carry blood from heart to supply whole the body and Veins are those that return all the blood from whole body back to the heart. In between Heart passes whole the blood from lungs so as to oxygenate it. In this way blood circulates in a closed system of vessels.
In order to push blood through the vessels Heart performs its function as a pumping device. Heart exerts a certain force upon an amount of blood at a time so that when blood ejects from it and passes through large vessels it is pressurized. The force exerted on the blood vessel by the heart pumping is known as blood pressure.
In certain individuals it is found that they have naturally a lowered or an elevated blood pressure. In most of cases nearly 90% cause of this problem is not known but in certain cases kidney problem is largely responsible for an elevated BP. Whereas depletion of body fluids as in diarrhea and vomiting of naturally decreased pumping effectiveness of heart may be responsible for a lowered blood pressure.
People who suffer from high blood pressure may suffer from headache, restlessness, tremors, blurring in vision, etc. They are advised to take plenty of fluids and vegetables and fruits and restrict salt, fatty diets, spicy foods, excess dairy products and meat of organs like brain, liver, kidney, etc 

Those people who are having low blood pressure may complain of headache, dizziness, vertigo, excess sleep, cold extremities, etc They should take plenty water, salty diets, fruit juices, and calcium supplements if advised by doctor.
High blood pressure, although does not have any lethal effects in short term but in long term it can kill a person. It may lead to kidney failure, heart attack, stroke, arteriosclerosis, etc
Low blood pressure may end up with circulatory failure, coma and death.
Low blood pressure is more dangerous than high blood pressure.