Health Scan: Prehistoric TB bacteria discovered near Haifa
Israeli and UK Researchers have found DNA from human tuberculosis bacteria in the 9,000-year-old bones of what a mother and baby found at Atlit-Yam, which is now submerged off the coast of Haifa. It is reportedly the earliest known case of human tuberculosis ever identified, using paleopathology and molecular analysis of the bacteria\’s DNA.
The researchers – headed by Prof. Israel Hershkovitz from Tel Aviv University\’s Sackler Medical School and colleagues from the Hebrew University of Jerusalem and the Universities of Birmingham and Salford in the UK- found that the DNA of M. tuberculosis in these skeletons had lost a particular piece characteristic of a common family of strains present in the world today
The research has just appeared in the online Public Library of Science (PLoS) journal.
The researchers found that the bones date back to the pre-pottery Neolithic Period. This is about 3,000 years earlier than any other reports of human tuberculosis bacteria. They confirmed that the infecting organism is definitely the human strain of tuberculosis and not one that had evolved from bovine tuberculosis. There had been a theory that human TB evolved from bovine TB after the domestication of animals, but gene analysis showed this was extremely unlikely.
The new finding proved that in a community dating after domestication of animals but before the use of animals to produce milk, the infecting strain was the human pathogen. Their proof that the DNA of the M. tuberculosis in these skeletons had lost a particular piece characteristic of a common family of strains existent today provides «a much better idea of the rate of change of the bacterium over time and indicates an extremely long association with humans,» the researchers said.
Tuberculosis is a major global cause of death and disease, and around two billion people – about one third of the world\’s population – are believed to be infected with tubercle bacilli. Yet only around a tenth of infected persons become ill with active disease.
CONNECTIONS BETWEEN SENSES
Hypnosis can induce synesthetic experiences in which one sense triggers the involuntary use of another, according to a new study in the journal Psychological Science, published by the Association for Psychological Society. An international group of researchers suggests that people with synesthesia do not necessarily have extra connections in their brain; rather, their brains may simply do more «cross talking,» and this can be induced by changing inhibitory processes.
The research, «Induced cross-modal synesthetic experience without abnormal neuronal connections,» was conducted by an international group that included Roi Cohen Kadosh, previously a doctoral student at Ben-Gurion University of the Negev under the supervision of Prof. Avishai Henik from BGU\’s psychology department and now at the University College London (UCL); Andres Catena from the University of Granada in Spain; Vincent Walsh from UCL; and Luis Fuentes from University of Murcia in Spain.
People living with synesthesia (known as synesthetes) experience abnormal interactions between the senses. People with digit-color synesthesia, for example, will experience certain numbers in specific colors (for example, they might experience the number seven as red). A possible reason for this phenomenon is the existence of extra connections between brain areas, but this new study suggests otherwise. To explore the alternative theory of more cross talk (disinhibition) between brain areas in synesthetes, Cohen Kadosh and colleagues used posthypnotic suggestion to show that people who are not synesthetes can be induced to have synesthetic experiences.
After inducing digit-color synesthesia, the volunteers reported similar experiences to those undergone by real synesthetes. For example, one participant described her experience while under posthypnotic suggestion as «When I\’m walking on the street, the car registration numbers – if those numbers are on the registration – I see them in those colors.» Moreover, hypnotized participants failed a catch test which was also failed by real synesthetes: when subjects were hypnotized to experience seven as red (for example), they could not detect the number when a black seven was presented on a red background.
Cohen Kadosh explains: «Our study shows that hypnosis can induce synesthetic experiences in people, suggesting that extra brain connections are not needed to experience cross-sensory interactions and that it is a change in inhibitory processes – more cross talk within the brain – that causes these experiences.»
BLOOD TEST FOR DOWN?
Until now, the most accurate way to determine whether a fetus has Down syndrome is to perform invasive procedures such as amniocentesis or a chorionic villae samples. However, this poses a small risk to the fetus, is uncomfortable for the mother and is relatively expensive. Now researchers at the Howard Hughes Medical Institute in Maryland and colleagues at Stanford University in California claim to have developed and tested – in a small study of 18 women – a prenatal blood test that accurately detected the cause of this disability and two other chromosomal defects.
Prof. Stephen Quake and colleagues published their findings recently in the Proceedings of the [US] National Academy of Sciences (PNAS). It has been known for years that a pregnant woman\’s blood contains minute amounts of fetal DNA. The scientists say they have found a way to scan such fetal DNA to find out whether the fetus\’s cells contain extra chromosomes associated with birth detects.
According to a UPI report, the test is claimed to be more accurate than amniocentesis and chorionic villae sampling. «We believe this is the first demonstration of a universal, non-invasive test for Down and other aneuploidies,» Quake said in a statement. «We need a larger clinical study to understand a bit more about the best way to implement it.»
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