Archives for category: Genetics

From Harvard Gazette:

Life evolved in a toxic world long before humans began polluting it, according to a University of Massachusettsenvironmental toxicologist, who added that understanding life’s evolutionary response to environmental poisons can help people to fight destructive effects.

Emily Monosson, an adjunct professor in the UMass Department of Environmental Conservation and author of the book “Evolution in a Toxic World,” said that an understanding of both how rapidly and how slowly life can evolve to fight toxic pollutants is largely missing from toxicology, which is the science of understanding the effects of poisons on life, particularly human life.

Monosson, who spoke Thursday at Harvard’s Haller Hall in an event sponsored by the Harvard Museum of Natural History, said lessons from our evolutionary past that might help us avoid trouble have been ignored by toxicologists and industry alike.

Monosson said she wrote the book in an effort to get toxicologists to think differently about their field, which she said still uses tools that are 40 years old and badly need updating.

“The basic point of doing this book is to get toxicologists to look differently at our field,” Monosson said. “Toxicology needs to change.”

Examples abound on the ramifications of rapid evolution, she said. Bacteria reproduce so fast that they quickly evolve resistance to drugs used to treat disease, resulting in frightening new ailments such as multidrug-resistant tuberculosis. Similarly, insects can rapidly evolve resistance to pesticides, and weeds can evolve resistance to herbicides.

“Roundup Ready” soybeans offer an example where a better understanding of the rapidity of evolution might have helped, Monosson said. The soybean was genetically modified to be resistant to the herbicide Roundup, which could then be sprayed on soybean fields, where it would kill weeds but not the soybeans. Officials believed that the weeds would not become resistant to Roundup. But after blanket applications, it appears that some resistance is evolving.

Slow evolutionary change also holds lessons for toxicologists and industry, Monosson said. Estrogen receptors help to control the body’s use of the critical reproductive hormone. Some industrial chemicals bond with the receptor, widely disrupting reproduction of an array of creatures.

Estrogen receptors are highly conserved, meaning they are widespread among many kinds of creatures and have changed extremely slowly over time, an indication of their evolutionary importance. An understanding of that importance would have helped officials predict that chemicals interfering with them would have widespread and deleterious environmental effects, Monosson said.

“There’s a lot of problems we could have avoided if we understood the power of evolution in the presence of toxic chemicals,” Monosson said.

It is unknown how humans today will respond to the many chemicals, usually at low levels, that our bodies are carrying. Some of these chemicals may be harmless alone but could have interactions with other chemicals in our bodies, Monosson said.

“Those chemicals in us today weren’t in our grandparents,” Monosson said. “If we take an evolutionary approach to understand how systems evolved to detoxify chemicals, maybe we can learn how to do it [ourselves].”

A toxic Earth is nothing new to life, Monosson said. When life began 3.8 billion years ago, there were poisons all around. Besides the presence of metals and other toxins in the environment, early microbes were bombarded from above. The early Earth had little oxygen in the atmosphere and no protective ozone layer to shield the microbes from ultraviolet (UV) rays.

In response, early life evolved an enzyme, photolyase, to repair the UV damage to DNA. That enzyme, though lost in most mammals, remains widespread in other types of creatures.

Another early example involved oxygen, which is very reactive and on the early Earth acted like a poison. Life has since evolved to handle and depend on oxygen. One strategy evolved to break down hydrogen peroxide, a highly toxic chemical that forms naturally in the presence of oxygen, water, and UV rays. Early life developed an enzyme called catalase to detoxify hydrogen peroxide, accelerating the natural breakdown process from weeks to a fraction of a second.

In the future, climate change promises to alter the range of many creatures, putting them in new environments to which they’ll have to adapt. The ozone hole is exposing creatures to higher levels of UV radiation than they’re adapted to handle. And human-generated pollutants continue to be released into the environment, presenting an environmental challenge for a wide array of creatures.

Some, like Hudson River fish that have evolved to thrive despite the presence of polychlorinated biphenyls (PCBs), will evolve their own solutions, but others may need human intervention to handle an environment whose toxicity is changing much more rapidly than in the past.

“The problem today is that in a blink of time, we changed the Earth,” Monosson said. “We’ve added a lot of new synthetic chemicals and redistributed a lot of natural chemicals.”

Read entire article here.

Image by Kris Snibbe/Harvard Staff Photographer.

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From EurekaAlert (a press release about research by Upstream Expert Frederica Perera):

According to a new study, children exposed to high levels of the common air pollutant naphthalene are at increased risk for chromosomal aberrations (CAs), which have been previously associated with cancer. These include chromosomal translocations, a potentially more harmful and long-lasting subtype of CAs.

Researchers from the Columbia Center for Children’s Environmental Health (CCCEH) at the Mailman School of Public Health, Columbia University Medical Center, and the Centers for Disease Control and Prevention (CDC) report the new findings in Cancer, Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Naphthalene is found in both outdoor and indoor urban air. It is present in automotive exhaust, tobacco smoke, and is the primary component of household mothball fumes. Classified as a possible carcinogen by the International Agency for Cancer Research, naphthalene belongs to a class of air pollutants called polycyclic aromatic hydrocarbons (PAH). Prior research at the CCCEH has established a link between prenatal exposure to PAH and increased risk for childhood obesity, IQ deficits, and CAs. The new study is the first to present evidence in humans of CAs, including translocations, associated with exposure to one specific PAH—naphthalene—during childhood.

The researchers followed 113 children, age 5, who are part of a larger cohort study in New York City. They assessed the children’s exposure to naphthalene; a CDC laboratory measured levels of its metabolites—1- and 2-naphthol—in urine samples. (Metabolites are products of the body’s metabolism, and can serve as marker for the presence of a chemical.) Researchers also measured CAs in the children’s white blood cells using a technique called fluorescent in situ hybridization. Chromosomal aberrations were present in 30 children; of these, 11 had translocations. With every doubling of levels of 1- and 2-naphthol, translocations were 1.55 and 1.92 times more likely, respectively, to occur.

CAs have been associated with increased cancer risk in adults. Translocations are of special concern as they result in a portion of one chromosome being juxtaposed to a portion of another chromosome, potentially scrambling the genetic script. “Translocations can persist for years after exposure. Some accumulated damage will be repaired, but not everyone’s repair capacity is the same. Previous studies have suggested that chromosomal breaks can double an adult’s lifetime risk for cancer, though implications for children are unknown,” says first author Manuela A. Orjuela, MD, ScM, assistant professor of clinical environmental health sciences and pediatrics (oncology) at Columbia University Medical Center and a pediatric oncologist at NewYork-Presbyterian Morgan Stanley Children’s Hospital.

To obtain a better sense of the long-term consequences of naphthalene exposure, Dr. Orjuela and other CCCEH investigators are following some of the children in the study as they reach fourth grade. While they expect to see further translocations, they do not expect to see any signs of cancer in the white blood cells. “So far, the translocations seem to be random, and there has been no evidence of the specific translocations that are known to be associated with leukemia. This is entirely expected; leukemia is very rare.” Frederica Perera, DrPH, senior author on the paper, adds that “the findings provide yet more evidence of the vulnerability of the young child to carcinogenic air pollutants.”

The researchers hypothesized that naphthalene exposure was primarily from mothballs, which can release high levels of the chemical. Furthermore, according to previous research, some Caribbean immigrant families use mothballs as an air freshener. Other important sources of naphthalene in indoor air are tobacco smoke, paint fumes, cooking, and heating. The new findings have implications beyond the urban environment as elevated levels of naphthalene metabolites have been documented in rural communities using biomass-burning stoves (coal, wood)—another source of PAH exposure.

From NPR Blog:

The number of children diagnosed with autism jumped 23 percent between 2006 and 2008, according to the latest federal estimate.

Now, 1 in 88 children has been diagnosed with autism, according to figures from the Centers for Disease Control and Prevention.

The rapid rise prompted calls to declare the developmental disorder an epidemic. “This is a national emergency in need of a national plan,” Mark Roithmayr, president of the advocacy group Autism Speaks, said at a CDC media briefing Thursday.

But CDC scientists weren’t about to go that far. Instead, they said that most if not all of that startling increase could be due to better recognition of the disorder by parents, doctors and teachers.

“There is the possibility that the increase in cases is entirely the result of better detection,” Dr. Thomas Frieden, head of the CDC, said at the briefing.

From 2002 to 2008, the number of children diagnosed with an autism spectrum disorder has risen 78 percent, according to this ongoing study, which tracks diagnoses among 8-year-olds in 14 states. It was published in the CDC’s Morbidity and Mortality Weekly Report.

The survey counted not just children who had been given an official diagnosis of autism, but those whose school or medical records included descriptions of behavior typical of the disorder. Those methods have been consistent throughout the study.

Because there is no known cause for autism, the question of what’s fueled the swift rise in diagnoses over the past 20 years has been a major point of contention between advocates and scientists.

“In very much respect to Dr. Frieden, only part of the increase is better diagnoses,” Roithmayr said at the CDC today. “There is a great unknown. Something is going on here that we don’t know.”

Autism Speaks and other advocacy groups have long pressed the federal government to do more research on environmental causes of autism, including the unproven theory that childhood vaccines caused autism. Scientists have tended to focus on genetic causes of autism, and factors such as advanced parental age and premature birth, both of which increase a child’s risk of autism.

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From

Mount Sinai’s Dr. Landrigan discusses how obesity has become an epidemic within the United States. The rates of obesity have tripled since the 1970s, and this has led to a significant increase in type 1 and type 2 diabetes as obese children are at a much higher risk of developing diabetes.

Dr. Landrigan also provides tips on how to prevent obesity and the diabetes that commonly follows obesity. Studies are being conducted at the Children’s Environmental Health Center to determine whether there is a link between common chemicals and obesity.

To view Mount Sinai’s Children’s Health Campaign containing tips, facts, videos, articles and more on important children’s health issues such as diabetes, autism, asthma, allergies and nutrition, click here.

To view the Children’s Environmental Health Center, click here.

From

Mount Sinai’s Dr. Landrigan discusses the rise of autism in the United States. The Children’s Environmental Health Center at Mount Sinai has studied the causes of autism and found that chemical exposures can contribute to autism and other learning disabilities.

To view Mount Sinai’s Children’s Health Campaign containing tips, facts, videos, articles and more on important children’s health issues such as diabetes, autism, asthma, allergies and nutrition, click here.

To view the Children’s Environmental Health Center, click here.

From the Maine Public Broadcasting Network:

Maine is among just a handful of states that require manufacturers to report the use of certain chemicals in their products. It also has the earliest deadine for companies to report. This week the results are in, and more than 650 products are on the list. Business representatives and state regulators say the reported presence of the chemicals does not indicate there’s a risk present. But health advocates say the list will help consumers protect their health from chemicals that leach out of products.

Listen to the four minute story here.

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From The Mail:

Growing up in a remote community on the west coast of Scotland in the Fifties, there was little opportunity for a boy with an embarrassing problem to discuss it with anyone.

‘You can imagine how people would have reacted,’ says Wilf Stevenson, 64, now Lord Stevenson of Balmacara. ‘It is not a subject easy to raise even now.’

Lord Stevenson, opposition whip and former special adviser to Gordon Brown, was born with hypospadias, a condition where the urethra, which delivers urine and sperm, comes out on the shaft of the penis rather than the tip. It does not necessarily affect urinary or sexual function, but it can make urinating difficult.

As Lord Stevenson explains, with some understatement: ‘Although the condition is as common as hare lip or cleft palate, it simply wasn’t talked about, and isn’t now. I just had to deal with it, and it wasn’t easy.’

He is among the one in 50 people (around 1.2 million Britons) thought to have been born with some kind of disorder of sexual development (DSD) as a result of errors in their genetic code.

These cause abnormalities while a baby is growing in the womb, and range from mild genital abnormalities to ‘intersex’ conditions such as congenital adrenal hyperplasia — where the baby has female and male physical characteristics such as a womb and a penis.

Overall, DSDs causing ‘ambiguous’ genitalia affect an estimated one in 1,000 people.

However, Lord Stevenson’s condition is more common — and it may be becoming increasingly so, as a result of ‘gender-bending’ chemicals used in plastics and hormones excreted by women taking the Pill or similar drugs used in animal rearing.

Although the use of growth promoting hormones is illegal in the EU and other countries, there may still be a risk in imported meat. Traces of these hormones have also been found in drinking-water supplies in studies by the Environment Agency and Medical Research Council.

‘There is no doubt that male reproductive disorders are increasing, but for some reason it is hard to get people to recognise the fact,’ says Professor Richard Sharpe of the Medical Research Council’s Centre for Reproductive Health at Edinburgh University, who runs a research group looking specifically at men.

‘It is an issue which ought to attract a great deal more attention,’ he says.
Professor Ieuan Hughes of Cambridge University, whose research focuses on abnormal sexual development in humans, says studies show a rise in the problem of undescended testes, where the organs remain within the body cavity of male babies, creating a risk of future infertility.

‘The latest research shows 7 to 8 per cent of babies are affected, and it was half that in the Sixties,’ he says.

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From the Chicago Tribune:

Pregnant women sacrifice many of life’s simple pleasures — caffeine, sushi, a glass of wine — in the hope that their baby will be born healthy.

But according to a provocative new field of research, what happens during pregnancy can have lasting consequences that emerge decades after the child leaves the hospital. Studies are finding that adult illnesses like heart disease, stroke, cancer and diabetes can have roots in the mysterious months we spend in the womb.

Although genetics and lifestyle choices certainly influence an adult’s risk of getting a disease, researchers now believe that the food a pregnant woman eats, her weight and fitness, her stress level, and the drugs, pollutants and infections she is exposed to can trigger changes that also make her baby vulnerable to disease after birth.

For example, scientists have found that a diet containing excessive protein can suppress fetal growth and lead to adult-onset hypertension. Expectant mothers who starved during their final trimester as a result of the Dutch famine of 1944-45 were more likely to have babies who later developed Type 2 diabetes. And the children of obese mothers also are at high risk of Type 2 diabetes and metabolic syndrome.

“Human beings break down the same reason cars break down; they’re either driven on bad roads or made badly in the first place,” said David Barker, a professor of clinical epidemiology at England’s University of Southampton, who in 1989 initially advanced the idea that coronary heart disease might originate in fetal life. “Some people are just strong and some are not. Being made bad means, biologically, that you have fewer functioning units.”

Experts stress that this field of study is relatively new and that the physical mechanisms that might explain the correlations between stressors in the womb and mechanical problems down the road are unclear.

It is also not lost on researchers that some pregnant women already are wracked with guilt over forgetting their prenatal vitamins or eating hot dogs instead of broccoli.

“I feel like a walking bomb,” said Chicago’s Amy Elstein, 28, who is five months pregnant and fears that her stress levels are affecting her baby. “It’s like my body is not my own. Everything I put into it — what I eat, what I breathe — I worry that will have an effect on my child.”

“Pregnancy feels like a period in your life when you want very badly to do the right thing, but you don’t have control of what’s going to happen, so women look for areas they can control,” said Dr. Ann Borders, an assistant professor of obstetrics and gynecology at Northwestern University. “We’re trying to help women be aware of unhealthy stresses but not freak out that they’re hurting baby for long term.”

The current advice for pregnant women still stands: Eat nutritious foods, exercise, reduce stress and avoid smoking and drinking.

But Barker and other scientists in the field want to step up prenatal care radically because they believe the diets of girls and young women are determining the health of the next generation.

Eventually, this area of research “will make a huge impact on not just what we tell women during pregnancy, but what our children’s health will be,” said Alan Guttmacher, director of the National Institute of Child Health and Human Development.

It was once widely assumed that, aside from cigarette smoke, drugs and excessive alcohol, the uterus, or womb, sheltered the fetus from environmental influences. Scientists also thought that the growing fetus could siphon off necessary nutrients from a mother like a parasite to ensure its survival.

Two decades of research into the fetal origins of disease, however, have challenged both assumptions and led to a revolutionary shift into the thinking about health and development.

According to Barker’s widely accepted fetal origins theory, also referred to as the developmental origins of health and disease, stressors in the womb can permanently change a fetus’s body structure, physiology and metabolism. Those changes then can lead to a higher risk of illness in the future.

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(Image from Flickr.)

From Reuters:

People who have never smoked, but who live in areas with higher air pollution levels, are roughly 20 percent more likely to die from lung cancer than people who live with cleaner air, researchers conclude in a new study.

“It’s another argument for why the regulatory levels (for air pollutants) be as low as possible,” said Francine Laden, a professor at the Harvard School of Public Health, who was not involved in the research.

Though smoking is the number one cause of lung cancer, about one in 10 people who develop lung cancer have never smoked.

“Lung cancer in ‘never smokers’ is an important cancer. It’s the sixth leading cause of cancer in United States,” said Michelle Turner, the lead author of the study and a graduate student at the University of Ottawa.

Previous estimates of how many non-smokers get lung cancer range from 14 to 21 out of every 100,000 women and five to 14 out of every 100,000 men.

The fine particles in air pollution, which can irritate the lungs and cause inflammation, are thought to be a risk factor for lung cancer, but researchers had not clearly teased apart their impact from that of smoking.

In this study, Turner and her colleagues followed more than 180,000 non-smokers for 26 years. Throughout the study period, 1,100 people died from lung cancer.

The participants lived in all 50 states and in Puerto Rico, and based on their zip codes, the researchers estimated how much air pollution they were exposed to — measured in units of micrograms of particles per cubic meter of air.

Pollution levels in different locations ranged from a low of about six units to a high of 38. The levels dropped over time, however, from an average of 21 units in 1979 – 1983, to 14 units in 1999 – 2000, producing an overall average pollution level of 17 units across the study period.

After the team took into account other cancer risk factors, such as second-hand smoke and radon exposure, they found that for every 10 extra units of air pollution exposure, a person’s risk of lung cancer rose by 15 to 27 percent.

The increased risk for lung cancer associated with pollution is small in comparison to the 20-fold increased risk from smoking.

And the study team didn’t prove that the pollution caused the cancer cases, but “there’s lots of evidence that exposure to fine particles increases cardiopulmonary mortality,” Turner told Reuters Health.

Fine particles in air pollution can injure the lungs through inflammation and damage to DNA, Turner’s team writes in its report, published in the American Journal of Respiratory and Critical Care Medicine.

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From Scranton Times-Courier:

The figure is so astounding it appears to be a misprint at first glance.

One in 110.

That’s the number of American children living with an autism spectrum disorder (ASD), based on the most recently published estimates from the Centers for Disease Control and Prevention (CDC). Boys are four to five times more likely than girls to be diagnosed with an ASD. And with a 10 to 17 percent annual growth rate, it is the country’s fastest growing developmental disability, according to the Autism Society.

A 2005 census study commissioned by the Pennsylvania Department of Welfare’s Bureau of Autism Services estimated about 20,000 Pennsylvanians, children and adults, were living with autism, although the study noted that the number was on the conservative side. The bureau now believes that number has grown to between 25,000 and 30,000 state residents.

* * *

While a clear and definitive cause for autism has yet to be determined, most physicians believe genetic makeup plays a significant role. Children who have a sibling or parent with an ASD are at a higher risk of also having one, and ASDs tend to occur more often in people who have certain other medical conditions or genetic disorders, such as Fragile X syndrome, tuberous sclerosis and Down syndrome.

“Really, where we’re sort of at is that the genetic investigations are at their earliest stages,” Dr. Challman said. “A variety of genes have shown to be involved in autism. They have to do with how the brain organizes itself. Brain circuitry. But we don’t know what they do. We just know they affect autism.”

* * *

There may also be environmental factors related to the cause of autism, but, as of yet, “there’s no clear evidence,” Dr. Challman said.

Right now, there are countless studies investigating a number of things that might be a potential environmental contributor, be it prenatally or during the child’s early development. The list includes prenatal vitamins, neurotoxins in the air, water and food supply, industrial waste, levels of bisphenol A (BPA) in kids’ canned foods, food additives and preservatives and pesticides, said Donna Ferullo, director of program research for the Autism Society.

Even maternal stress and age at the time of the child’s birth are being studied, Ms. Ferullo said.

“We live in this soup of low-level exposure. There’s so many threats to the developing brain that we weren’t exposed to years ago,” Ms. Ferullo said. “Environment is suspect, but not clarified. There are numerous environmental factors under investigation. The problem is isolating it.”

For years, there have been fears among many parents’ groups that vaccines were a potential cause of autism. This was due in large part to a study that came out of England several years ago that implicated the MMR vaccine, which protects against measles, mumps and rubella. That study, though, was later found to be fraudulent, Dr. Challman said.

* * *

“So there was some information that was published and it was incorrect and it made people scared,” Dr. Challman said. “It’s a belief that’s not based in science. There’s a mountain of evidence that exonerates vaccines.”

As the CDC collects more data and enhances its surveillance techniques, researchers will begin to understand more about the disease, Mr. Baio said. One recent development, he said, is the establishment of a controlled testing of three groups – children with autism, children with other developmental disabilities and children who appear to be developing typically.

“We’ll be able to compare and contrast across these three groups. The hope of that is we’ll identity some factors, be it risk factors, or things that can assist us with identifying children earlier,” he said. “Then they can get autism-specific treatments much earlier, which would have a much greater outcome.”

“In a lot of ways, we’re behind other fields of study,” Dr. Challman said. “It is frustrating for families. Sometimes the wheels of science do turn rather slowly, but if we persist, we make progress.”

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From the Montreal Gazzette:

Early childhood living conditions provoke biological changes in genes leading to DNA “memory” that can last a lifetime, an international study has found.

Experts have already noted that income, education and neighbourhood resources can have a dramatic effect on children’s health, and that a poor socio-economic environment in infancy can translate into a higher risk of adult disease and early mortality.

But a study published online Thursday in the International Journal of Epidemiology suggests that early experience works changes that are far more than skin deep.

The environment of early childhood influences brain and biological development and leaves a “memory” in the genetic code that affects the way genes function, say researchers from McGill University, the University of British Columbia and the UCL Institute of Child Health in London, England.

“Biological embedding” may help explain why health disadvantages linked to a lower socio-economic origin — including obesity, mental health problems, heart disease, diabetes and other chronic illnesses — can last a lifetime even if living conditions improve later.

The team focused on a small sample — 40 men — from the ongoing British cohort study, which has followed 10,000 people born in March 1958 from birth onward.

The team looked at the DNA of men aged 45 who came from one of two economic extremes: children whose fathers were unskilled workers; and those whose dads were company CEOs and Oxford/Cambridge graduates.

“We wanted to sample from the extremes so that if there was an epigenetic (gene) signal, it would be as clear as possible — and that’s in effect what emerged,” said Clyde Hertzman, director of the UBC-based Human Early Learning Partnership and an author of the study.

After looking at control areas of 20,000 genes, researchers found twice as many genetic differences (1,252 changes) in those brought up in wealth and comfort compared to those raised in poor living conditions (545 changes), making a link between the economics of early life and the biochemistry of DNA.

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From Environmental Health News:

Bisphenol A (BPA) can alter the way genes are read in male rats exposed to the chemical as newborns. The so-called epigenetic changes had lasting effects on reproductive hormone signals into adulthood that may partially explain reported effects of the chemical on male fertility.

The findings add to a growing body of research showing that BPA can impact the way genes are coded and then interpreted later in life during sexual maturity. Such changes have been documented in the brain, prostate and uterus.

The early-life exposures added chemical groups to two important genes on the DNA in the testes and increased the levels of enzymes that control these epigenetic additions. Due to the broader impact on these enzyme levels, newborn BPA exposure may affect more genes and levels of control than identified in the current study.

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From

[Upstream Contributor] Dr. Frederica Perera touches on how the environment around us can make a big impact very early in life and stick with us for a long time. This short take was shot during a break at Keystone Symposia’s meeting on Environmental Epigenomics and Disease Susceptibility held in March 2011 in Asheville, North Carolina.

 

From the Milwaukee Journal Sentinel:

Scientists are learning that health is the function of genes and environment. The work of Milwaukee-based researchers suggests that this principle also applies to the health of a growing fetus and a premature infant.

Michael Laiosa, assistant professor at the University of Wisconsin-Milwaukee School of Public Health, and neonatologist Venkatesh Sampath, an assistant professor of pediatrics at the Medical College of Wisconsin, want to understand how genetics and the environment affect the health of humans during the most vulnerable stages of development.

In Milwaukee, there were 807 infant and fetal deaths between 2005 and 2008, according to the city’s Fetal Infant Mortality Review. A disproportionate number were African-American. Of the 499 who were not stillborn, nearly 54% died from complications of being born too soon.

During gestation and early in life, infants reach developmental milestones at a rapid pace. But in the presence of a dysfunctional gene, toxic exposures, or a combination of both, development is prone to error.

According to Sampath, who is collaborating with colleague Ronald Hines, professor of pharmacology and toxicology at the Medical College, some premature babies may be more susceptible to necrotizing enterocolitis, or NEC, a leading cause of mortality and disability in very low birth-weight preterm infants weighing less than 3½ pounds.

What causes this disease is unknown, but doctors believe that an underdeveloped immune system or intestinal lining may leave a preterm infant’s bowel vulnerable to infection or injury. What results is severe inflammation, which can lead to a deadly infection. Between 25% and 40% of babies afflicted with NEC die.

In their recent study published in the Journal of Surgical Research, Sampath and Hines detected a variant of a gene called NFKB1, differing slightly from the normal form, which is involved in mounting an immune response. Investigators said premature infants with a genetic variant may be at higher risk for developing the potentially fatal NEC.

In the study of 270 very low birth-weight preterm infants, investigators reported that of the 15 infants diagnosed with NEC, all had at least one copy of the defective gene and were disproportionately African-American.

“African-American infants run a higher risk of NEC,” Sampath said of the study findings.

The defective gene turned up in 65% of infants not diagnosed with NEC, suggesting that other factors are involved in the onset of the disease. Sampath said it may be the presence of a particular bacteria, poor blood flow to the intestines, or another malfunctioning gene.

Infants with NEC experience pain, according to Sampath. “It’s a nasty disease,” he said.

Sampath added that those infants who survive a severe case of NEC are at greater risk for developmental delays and cerebral palsy.

Jackie Sevallius, supervisor of the newborn intensive care center at Wheaton Franciscan-St. Joseph hospital in Milwaukee, cares for infants with NEC and said signs of pain in a preterm infant are often subtle and manifest as changes in blood pressure, heart rate, breathing and color.

Very low birth-weight babies unable to muster a cry will express their pain through a facial grimace, said Sevallius.

Whether the variant gene can be used as a marker of NEC susceptibility in preterm infants is not yet clear.

“At this stage, it is preliminary, which means it needs to be addressed in a large amount of patients before we can tell for sure. It is worth further digging,” Sampath said.

David Hackam, professor of surgery at the University of Pittsburgh School of Medicine, said Sampath’s studies may one day offer doctors a way to screen premature infants for increased risk for NEC. Early screening could lead to earlier diagnosis and treatment, he said. Current treatments include changes in feeding, antibiotics and surgery. “These studies make a strong case for further genetic studies to understand this complex and devastating disorder,” Hackam said.

Sampath said he hopes to explore whether this genetic variant can be used to predict other diseases of prematurity.

Developmental origins

How the outside world leaves its imprint on a growing fetus and potentially affects health later in life is an emerging field of research. A pregnant woman’s lifestyle choices, nutrition, exposure to toxicants – and even stress – may modify when and how genes are expressed during the course of fetal development.

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From :

Kent Berridge, Professor of Psychology and Neuroscience at the University of Michigan, Ann Arbor, discusses his lab’s research into fundamental question about the brain and behavior. He discusses how food pleasure is generated in the brain, the neural bases of wanting and liking, and how fear and stress relate to desire.

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