Asthma and Bacteria – A Possible Link

Asthma remains a baffling disease that impacts a growing number of individuals, especially children. Asthma is characterized by a constriction and swelling of the airways. The symptoms include the production of mucus and more importantly coughing, wheezing and a shortness of breath. Currently there is no cure for this condition but medications can be used to control it. The severity of this disease varies widely; it can be vary from a nuisance to a life threatening condition.

Recent evidence suggests that there is a strong connection between asthma and the kinds of bacteria that the body ordinarily harbors. Some years ago, Dr. Gary Huffnagle, an immunologist from the University of Michigan, subjected experimental mice to yeast introduced into their intestines; mold spores placed in their noses and an antibiotic drug. These animals began showing signs of asthma and blood tests indicated immune system dysfunction.

In addition, studies have indicated that children raised on farms are much less prone to suffer from diseases of the lung, including asthma, and Dr. William Cookson, a respiratory physician from the Imperial College of London, suggests that exposure to a diverse bacterial environment in childhood may play a protective role. Additionally, children born via the sterile environment of a cesarean section are more prone to suffering from asthma than those that have passed through the birth canal, and children that have had multiple courses of antibiotics are more likely to have asthma than their counterparts.

The relationship between asthma and the bacteria that ordinarily reside within the body is an exceedingly complex one. Yet, it has become clear that children who are stricken by asthma have different bacteria within their bodies and often a less diverse population than non-asthmatic children. The findings of these studies reinforce what has long been suspected regarding asthma,

Deepwater Horizon Blowout - Existence of Undersea Plumes of Oil

The environmental catastrophe caused by the blowout of the Deepwater Horizon at the Macondo well site resulted in the largest offshore oil spill in history. Although much of the surface oil contamination has been significantly mitigated, there remains an issue regarding the existence of undersea hydrocarbon plumes.

These plumes have been tracked by Dr. Richard Camilli and his colleagues from the department of Applied Ocean Physics and Engineering at the Woods Hole Oceanographic Institution. As a result of the blowout, more than 4 million barrels of oil were released into the Gulf of Mexico. Since the source of the spill was some 1500 meters beneath the surface, this resulted in the formation of undersea plumes of oil. On account of the complex variables that are involved in plume formation – the interplay of gas and oil in multiphase flow and the solubility of each of the constituents in the complex mixture - , it is exceedingly difficult to derive models that can reliably predict the behavior of hydrocarbons under such conditions.

In spite of the daunting problems associated with this catastrophe, the investigators were able to detect and measure the hydrocarbon plumes. They discovered the presence of a continuous plume of oil more than 35 kilometers in length at an approximate depth of 1100 meters. This plume persisted for months without signs of significant biodegradation.

Further studies by other investigators, however, have shown that the presence of the plume stimulated the growth of bacteria that are known to degrade hydrocarbons. The encouraging aspect of their findings is that, “the potential exists for intrinsic bioremediation of the oil plume in the deep-water column without substantial oxygen drawdown.”

The existence of undersea hydrocarbon plumes in the Gulf of Mexico has inspired scientific investigators to study their properties. The results of their work may lead to strategies designed to counter the ill effects of similar human catastrophes should they happen in the future.

Virus Discovered as a Causative Agent in a Disease Prevalent in Central China

There have been many reported cases of a deadly fever outbreak in Central China. Numerous instances have been reported for the last three summers. The inexplicable illness is characterized by high fever and gastrointestinal distress (GI). Many of the individuals impacted by this illness bled severely, and, most alarmingly, as many as 30% of the victims have died. At first, scientists at the Chinese Center for Disease Control and Prevention (CDC) postulated that the disease was a form of human granulocytic anaplasmosis (HGA) a bacterial infection spread through tick bites.

Xue-jue Yu, a visiting scientist studying this illness at the Chinese CDC’s National Institute of Communicable Disease Control and Prevention (NICDC), was skeptical of this explanation. According to him, the mortality was too high, and, more conclusively, examination of blood samples did not reveal the presence of Anaplasma phagocytophilum - the bacterial agent that is responsible for HGA. Pursuing this problem, his team finally discovered a new type of bunyavirus as the culprit. Members of this family of viruses include the hantavirus and the Rift Valley fever virus. Hantavirus is responsible for a serious illness referred to as hantavirus pulmonary syndrome (HPC) spread by infected rats to humans. Yu’s results were subsequently reported in the New England Journal of Medicine (NEJM).

This is a rather disturbing finding and may point to the emergence of a new virus with a potentially deadly outcome for those infected. It is certainly worth increased attention on the part of public health professionals throughout the world.

Uncovering the Mode of Action of H. pylori Known to Cause Stomach Cancer and Gastric Ulcers

There are a number of cancers that have been linked definitively to infectious agents. T-cell leukemia has been shown to be caused by HTLV1, a retrovirus very similar to the virus that causes AIDS. The human papillomavirus (HPV) has been implicated in cervical cancer, and primary liver cancer has been shown to be caused by the Hepatitis B virus.

There is now clear evidence that a bacterial infection commonly found in the stomach caused by Helicobacter pylori (H. pylori) is responsible for stomach ulcers and cancer of the stomach. It has been found in 70% of those individuals with stomach cancer and is carried by 50% of the world’s people. This bacterium has a characteristic corkscrew morphology – shape. It has been proposed that the H. pylori pathogen is protected from the harsh acidic conditions of the stomach by its ability to bore into the protective gastric mucosal lining. It has also been established that H. pylori infection may lead to chronic inflammation that can trigger either gastric ulcers or cancer.

Dr. Nina Salama and her team at the Fred Hutchinson Cancer Research Center in Seattle successfully created genetically modified H. pylori that lacked four essential shape-forming proteins and as a result the organism lost its corkscrew morphology. As a consequence, these modified bacteria became less effective in attacking gastric tissue. H. pylori has a shape that is shared by other virulent bacteria including Vibrio cholerae that causes cholera and Campylobacter jejuni that is responsible for bacterial diarrhea.

Currently H. pylori is resistant to treatment with traditional antibiotics. However, discoveries such as the ones made by Dr. Salama offer hope that a more complete understanding of the mechanism of infection may eventually prove useful in treating the infection and preventing gastric ulcers and cancer in the future.

Kidney Disease as a Consequence of Genetic Resistance to a Parasite

It has been well established that carriers of the sickle cell trait – predominantly found in sub-Saharan African populations - have an innate resistance to malaria. There is now evidence of an analogous relationship between a genetically-determined resistance against an infective agent and disease - in this case involving kidney disease.

Research results coming out of the laboratory of Martin Pollak, a nephrologist and human geneticist from the Harvard Medical School in Boston, have established a link between certain renal (kidney) conditions and a parasite called Trypanosoma brucei that is spread in African populations by a tsetse fly vector and causes African sleeping sickness. The kidney diseases studied were focal segmental glomerulosclerosis and end stage kidney disease; both of these maladies are four or five times more prevalent in African American populations than those of European origins.

As a result of exhaustive genetic analysis, Pollak and his team identified two variants in the so-called APOL1 gene that strongly correlates with kidney illness. The variants were referred to as G1 and G2. G1 turned up in 52% of glomerulosclerosis patients as compared to 18% of controls, and the G2 variant was found to be 50% more common with either kidney disease. Furthermore, they went on to determine that if both of the APOL1 genes (genes normally exist in pairs – one residing on each member of a chromosome pair) carried one of the disease-bearing variants, the probability of expressing kidney disease would increase seven fold.

The APOL1 gene is responsible for the production of apolipoprotein L-1. It has been demonstrated that the apolipoprotein L-1 promotes degradation of the trypanosome parasite by forming pores in its membrane. Pollak and his colleagues discovered that individuals, who carried either G1 or G2 in their blood plasma, effectively killed a subspecies of parasite T. brucei rhodesiense that is resistant to the normal gene product as did the synthetic versions of the variant proteins.

These are very interesting findings that point to the complex relationship between parasites and the hosts they infect. In addition, the fact that the man-made variants G1 and G2 proved efficacious in killing the parasite may prove to be clinically useful.

Genetic Basis of Tibetans’ Adaptation to High Altitude

The ability of native Tibetans to tolerate high altitude is, of course, legendary. Tibetans living on the Tibetan plateau at elevations that exceed 4000 meters are exposed to an atmosphere that has oxygen concentrations that are approximately 40% lower than that which is available at sea level. From a biological perspective it is of interest to know how this has been achieved.

From the evidence accumulated by Jian Wang and his associates from the University of California at Berkeley, Tibetans have acquired a number of inherited adaptations to this extreme environment, including – higher birth weight, higher hemoglobin – the protein found in red blood cells that binds oxygen - levels, higher oxygen saturation in the blood of infants and adults following exercise when compared with a control group of Han Chinese who moved to Tibet and are genetically distinct. Tibetans have occupied the Tibetan Plateau for over 25,000 years, possibly enough time to accumulate genetic adaptations through natural selection.

In an attempt to delineate the genetic characteristics of these adaptations, the investigators analyzed the DNA from both Tibetans and the control group. There results demonstrated, in fact, a single-nucleotide polymorphism (SNP) – a single point variation in the DNA studied – from a gene that encodes for the EPAS1 protein. This protein has been shown to be involved in the body’s response to hypoxia – low oxygen environment. This change occurred at a much higher frequency in native Tibetans than in the control group of Han Chinese.

These results represent a very important finding in regards to the fact that this beneficial genetic modification occurred over a very brief interval of time as compared to previously studied human genetic adaptations.

An Argument for a Dramatic Improvement in the Science Education of Our Children

The technological wonders of the modern age are quite spectacular. One of the most profound of these is the Hubble telescope. Many human lives are saved and horrific diseases are averted daily due to the great strides made in the arena of health and medicine. The additional examples that could be cited are too numerous to mention here. Technological improvements are a direct outcome of the application of scientific enquiry and discovery.

The human world is beset with many problems that demand solution – the most urgent of these being climate change. There is a growing body of scientific evidence that supports this contention, including:

•Record setting high temperatures during the last ten years
•Erratic, severe and unusual weather conditions
•Increase in the frequency and severity of forest fires
•Increased acidity in the world’s oceans that has impacted the health of coral, phytoplankton and shelled creatures especially oyster larvae
•Melting and receding of glaciers worldwide
•Melting of the ice in the Arctic Ocean during the summer months.

The science that has established the relationship between the increased concentration of carbon dioxide and methane, the so-called greenhouse gases, resulting from human activity is clear and irrefutable.

In spite of these data, there is a marked resistance in this country to accept not only the obvious implication of these observations, but the meaningfulness of the observations themselves. This, to me, is extremely disturbing, for inaction or lack of sufficient resolve to confront this issue will inevitably result in disastrous consequences for future generations.

This inability to grasp the urgency of the issues that confront us is a direct result of the failure to educate our children in the realm of science. Science has some essential characteristics that make it exceedingly well suited for problem solving. It is cooperative effort; scientific advances are a direct result of strides made by investigators in the past as well as the present. Science depends on a growing body of knowledge; it builds upon all that has been already discovered. In addition, the scientific process is open-minded; any hypothesis or law must fit the data that is accumulated through observation. If new data does not fit the interpretation then the conclusions need to be modified to accommodate the newly acquired facts. Science requires a rigorous thought process that relies on higher-order functions in the human brain.

In my judgment, it is not possible to meet the challenges we face in this technologically-driven world without a sufficiently adequate education in the sciences. We have failed abysmally in this regard in the United States. Ignorance is not bliss by any stretch of the imagination. Ignorance will inevitably lead to erroneous conclusions and ultimate disaster.