Exercise your brain
ew light has been shed on the
well-known antidepressant effect of exercise by a pilot study reported
in the British Journal of Sports Medicine. It was suspected that an
endrophin-like substance, phenylethylamine, might be responsible for the
well-being associated with as little as four hours of exercise weekly.
On non-exercising days, urine samples were tested for phenylacetic acid,
a by-product of phenylethylamine turnover. Urine samples were again
collected after treadmill exercise in which heart rate had climbed to at
least 70% of maximal heart rate capacity, a level thought to be capable
of changing mood. Phenylacetic acid levels increased by ~ 77% after
exercise. However, the rise in levels varied widely across the group
tested, with maximal increases seen in those subjects who rated the
exercise as difficult. The authors believe that many factors might be
involved in the phenylacetic acid response to exercise but, considering
that the chemical structure of phenylethylamine is very similar to that
of amphetamines, this chemical might be part of a ‘runner’s high,’
a phenomenon linked to natural endorphin activity in the brain.
November 11 , 2001 TRENDS in Biochemical Sciences Vol. 26 No. 11
Beauty in chemical
chemical involved in immune system signalling may be able to
reverse some types of skin damage caused by sunlight. It could reduce
sunburn by activating DNA-repair mechanisms, suggests a new study by
researchers from Germany-based University
of Munster. This finding raises the possibility that the chemical might
be used to prevent or treat skin cancer. The researchers found that
IL-12 promotes repair rather than blocking ultraviolet rays, as most
sunscreens do.
December 31, 2023 Down To Earth
Injecting a cure
ith the help of a chemical, diabetes
sufferer with early symptoms could be prevented from developing the disease
completely, research has suggested. Trials found that a specific peptide- a
substance formed from amino acids- halted the progression of Type1 diabetes
(the insulin-dependent form that must be treated with injections) in humans
and mice. Jerusalem- based Hadassah-Hebrew University Medical school and
Peptor Limited, a pharmaceutical company also based in Israel, conducted the
research. It is hoped that the discovery could lead to the development of new
life-saving drugs.
December 31, 2023 Down To Earth
Bacteria modify the negative approach
ipid A constitutes much of the outer
lipid coat of disease-causing Gram negative organisms such as Escherichia
coli, Salmonella and Pseudomonas. A novel method of bacterial resistance
has been identified, by which an unusual sugar, aminoarabinose, is attached to
the lipid, with the overall effect of reducing the net negative charge of the
bacterial coat. Antibiotics (e.g. polymyxin) attach to the bacterial lipid
coat via positively charged groups, the interactions of which are lessened
with weakened negativity of the aminoarabinose-coated lipid. Duke University
Medical Center biochemist Christian Raetz (Durham, NC, USA) said, ‘…we
have discovered the enzyme that attaches this modifying group to lipid A, as
well as a novel precursor molecule (named undecaprenyl phosphate-aminoarabinose)
that donates this aminoarabinose to lipid A. It might be possible to redesign
peptide antibiotics to work even against bacteria with aminoarabinose attached
to their lipid A. …Also, one could imagine devising inhibitors of our
aminoarabinose transferase enzyme that would render polymyxin resistant
mutants sensitive again.’ The transferase enzyme was pinpointed by
genetically analysing a polymixin-resistant strain of Salmonella (the arn
T gene codes for the protein responsible for transferring aminoarabinose
to lipid A). A similar gene to arn T
has been identified in resistant strains of E. coli. In future studies, the
scientists will trace the full metabolic pathway, which could yield additional
enzyme targets for inhibitory drugs. These finding are being published in the
Journal of Biological Chemistry.
November 11, 2023 TRENDS in Biochemical Sciences Vol. 26 No. 11
Spinach can cure certain forms of blindness
pinach, the vegetable loved by Popeye,
could prove to be a remedy for certain forms of blindness. Doctors now believe
that an eyedrops containing a protein taken from spinach could be soon
available to treat the millions of people suffering from age-related macular
degeneration of the eye and retinitis pigmentosa.
Age-related macular degeneration is a common eye disease associated
with ageing that gradually destroys sharp central vision. The macula is made
up of millions of light-sensing cells in the middle of the retina. When these
cells degenerate, vision is impaired and if the disease progresses quickly,
blindness follows. Retinitis pigmentosais a genetic disease which affect about
one person in 4,000. Sufferers develop night blindness, then tunnel vision and
finally lose their colour and day vision.
December 2001 Health
Action
Cancer in the air
iving
in an environment polluted with even low levels of benzene can cause
cancer. While exposure to benzene at work place have been known to cause
cancer, a study published recently in the American Journal of Epidemiology
shows that exposure to low concentrations of the chemical such as those
present in vehicular emissions can also cause cancer.
Researchers from the Danish Cancer Society and the National
Environmental Research Institute, Denmark, found that children exposed to
traffic-related air pollution had more chances of being affected by
lymphomas, a cancer of the lymphatic system characterized by enlargement
of the lymph nodes and glands. The researchers studied 1989 cases of
children suffering from leukemia, tumour of the central nervous system and
malignant lymphoma that were registered in the Danish Cancer Registry
during 1968-1991. The histories were compared with the medical records of
5,506 healthy children selected at random. They then collected the
residential history of all these children starting from the time they were
conceived till the time the disease was diagnosed. The information was
used to assess the amount of vehicular pollution they were exposed to.
They also took into consideration other potential causes of cancer such as
exposure to electromagnetic radiation, mother’s age at conception and
level of urbanization.
They found that the risk of Hodgkin’s lymphoma increased by 25
per cent when the amount of benzene in the air was doubled during
pregnancy. Similarly, the risk increased by 51 per cent when the nitrogen
dioxide emissions present in the air doubled.
“This is a suggestive observation that will require
conformation,” says Lucy M Anderson of the National Cancer Institute,
USA. Even Ole Raaschou-Nielson, one of the research team member, agrees.
“We cannot rule out the fact that they might be numerous other factors
which can be the culprits,” says Raaschou-Nielson.
December 15, 2001, Down To Earth
Concern raised for missing biologist
tructural biologist are in shock
following the disappearance of Don Wiley, one of the leading figures in
the field. As Nature went to
press, more than a week after Wiley’s car was found abandoned near
Memphis on a bridge over the Mississippi river, the FBI was still
investigating.
A professor of biochemistry and biophysics at Harvard University,
Wiley has been seen as a candidate for Nobel prize. He won a 1995 Lasker
award for this resolution of the structure of the two classes of major
histocompatibility proteins. These proteins bind to foreign proteins,
altering the immune system to mount a response. Wiley’s work opened up
new vistas in immunology.
His other key work has been on the haemagglutinin protein of the
influenza virus. Wiley’s analyses led to understanding of how the virus
fuses with host-cell membranes. His further work on other viruses suggests
the mechanism may be general.
Wiley was last seen leaving a dinner following a meeting of the
scientific advisory board of St Jude Children’s Research Hospital in
Memphis, where he is said to have been in good spirit.
November 29, 2023 NATURE Vol. 414
Sweet news for diabetics
re you a diabetic? And, insulin’s
your life savior? Then here’s a herb that promises to solve all your
problems. Paneerdatta, a flower
is crushed gently to form small beads, dissolved in a cup of water for 12
hours, filtered and the water then drunk. Doctors say that if this is done
for one month, it will ensure that diabetes is controlled. They also say
that a patient may even discontinue medicines completely after about three
months of regular intake with this potion.
“Details of this are not being given out simply because plans are
afoot to patent this findings,” says Dr. O. P. Saxena , Head of
Department of Botany, Gujarat University.
December 2001, Health Action
First human clones get a cool response
n 25th
November, Advanced Cell Technology (ACT) of Worcester, Massachusetts,
announced that it had created a cloned human embryo. It claimed this as an
important step towards the goal of therapeutic cloning-in which cloned
embryos would be used to harvest embryonic stem (ES) cells to grow
replacement tissues perfectly matched to individual patients.
The ACT team fused adult cumulus cells –
ovarian cells that surround eggs after ovulation – with
human eggs that had been stripped of their own chromosomes.
In a press release, the company said that
the paper provides “the first proof that reprogrammed human cells can
supply tissue”.
The ACT clones are “nowhere near” that
stage, says Alan Colman.
Colman also notes that the development of ACT’s embryos compares
unfavourably with experiments in animals. “Clearly, just extrapolating
from the cow system into the human has not worked very well”, he says.
“With cows you could expect over 30% of the reconstructed eggs to go to
the blastocyst stage”.
Jose Cibelli, ACT’s vice-president of
research and the paper’s lead author, agrees the work is at an early
stage but argues that it is still of interest: “We understand that these
are early and preliminary results, but given the importance of this
emerging field of medicine we decided to publish our results now”.
While scientist debate the significance of
ACT’s finding, political opponents of cloning are attempting to outlaw
the research. The US Senate is considering a bill, already passed by the
House of Representative, that would ban all forms of human cloning, both
reproductive and therapeutic. Observers now expect this to be passed, and
to be signed into law by President George W. Bush.
November
29, 2001 NATURE Vol. 414
Technocure
range of internet enabled software tools that will help
control the spread of the anopheles mosquito-the vector for malaria and
filariasis – have been developed by scientists at the bio-informatics
division of Indian Institute, said the user-friendly programmes developed
by them will help forecast the onset of the disease and enable pro-active
measures by public health officials based on the data collected
and fed into the computer.
December 15, 2023 Down To Earth
US warning on obesity
ome 300,000 Americans a year die
from illnesses caused or worsened by obesity, a toll that may soon
overtake tobacco as the chief cause of preventable deaths, Dr. David
Satcher, the surgeon general , said on Friday. Dr. Satcher called for
major steps by schools, communities and industry to fight obesity.
“We’re
not talking about quick-fix diets,” Dr Satcher said.
“We’re talking about lifestyles.”
About 60 per
cent of adults are overweight or obese, as are nearly 13 per cent
children. According to the surgeon general’s height and weight index, a
5-foot-6 adult is overweight at 160 pounds and obese at 190. The toll of
obesity has been rising and threatens to wipe out progress fighting
cancer, heart disease and other ailments, Dr Satcher warned.
The reason is
not a mystery: People eat more calories – often by shunning fruits and
vegetables in favor of super-size junk foods-than they work off. Losing
even 10 pounds can reduce the risk of getting diabetes or heart disease,
Dr. Satcher said, as can walking 30 minutes a day.
December 15, 2001, Hindustan Times
New Danger
Swiss study
reveals that eating food cooked in a microwave oven may produce abnormal
changes in human blood, cell and the immune system suggestive of
conditions of cancer.
Curiously, the
study conducted as early as 1989 has come to light only recently. The
reason: Swiss courts, under pressure from microwave oven manufacturers,
had reportedly suppressed research by Swiss biologist, Dr. Hans Ulrich-Hertel.
The biologist evidence has been published in the journal What Doctors
Don’t Tell You.
Russian
studies indicate that microwaving meat, milk, cereals and thawing
fruits and vegetables produce carcinogens. Those consuming microwaved
foods have showed a higher incidence of stomach and intestinal cancers.
The US Food
and Drug Administration’s (FDA) Centre for Devices and Radiological
Health (CDRH), however, maintains that microwave oven cannot make food
radioactive or contaminated and cooking in them does not reduce the
nutritional value of foods.
In
the US, all microwave ovens made after 1971 are covered by a radiation
safety standard enforced by the US FDA.
The
major health and safety concerns about microwave ovens are:
i)
Leakage of dangerous microwaves resulting in exposure to radiation
and risk of cancer. Microwave radiation is odourless and invisible, making
it hard to detect. Other health hazards of exposure to microwave radiation
are cataracts, temporary sterility and mental impairment.
ii)
Fires and burns due to overheating /superheating and exploding
foods and drinks.
iii)
The belief and microwave cooking destroys nutrients.
iv)
Cooking in microwave oven does not kill harmful bacteria.
October 2001, Health Action
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Women close gap
but it’s still a man’s world
ashington female scientists have
increased their representation in the US scientific community, but still lag
behind their male colleagues in attending full-time, tenure-track positions,
according to a report by the US National Academic of Sciences. Women had
almost no representation in the community 25 years ago, but in 1995 they
accounted around a third of new a science PhDs and academic faculty in many
fields, though there is wide variation.
In engineering just 7% of degrees and 5% of PhD-level jobs in 1995
went to women, whereas in the biological sciences female scientists were
awarded 50% of all undergraduate degree and 40% of all PhDs.
November
22,. 2001 NATURE Vol. 414
Alternative medicine has bright prospectus
esides traditional medicinal
systems, alternative medicine would have bright prospectus in the coming
year, founder and chairman of Dhyanamandali (Vijayawada) C. Bhikshamaiah
guruji predicted on Monday.
Addressing a press conference after being awarded with ‘Star of
Millennium’ by the National council of Alternative Medicine recently.
Bikshmaiah said that amalgamation of meditation with radionics therapy was
proving good for curing chronic disease.
Stating that Reiki, pranic healing, oil pulling, acupressure,
acupuncture, magnetotherapy, radiation technology, aroma therapy and
naturopathy were some of the alternative medicinal systems available across,
the world, he observed that all the disease were psychosomatic. Insomnia,
depression and stress were responsible for the occurrence of the disease in
a person.
To cure chronic disease like a diabetes and arthritis, Dhyanamandali
has been adopting a procedure called ‘Multiyoga therapy treatment’ by
integrating available alternative medicine systems, he added.
January 2001, Health Action
Reduce stress to tame that flab
isruptions in the human nervous system,
or stress, can concentrate fat around the abdomen, raising the risk of
diabetes as well as heart problems, a study by the university hospital in
the Swedish city of Gothenburg found.
“ The stress system has developed to deal
with periods of brief stress for stone–age man preparing for battle or
flight. But in today’s civilized world, stress is different. One does not
beat up the boss or run away from the mortgage institute, “ said physician
Thoman Ljung, who led the study.
Researchers have found that fat plays an important role in protecting
bones and organs, regulating hormones and the immune system and managing
women’s reproductive systems. Fat produces an important hormone called leptin that communicates with the brain, informing it how the
body’s energy levels are doing.
Simon Coppack, a researcher at
the St Bartholomew’s and the Royal Londan School of Medicine and dentistry
said: “Fat is an organ. You should probably think of it as a little bit
like the liver” the hormone tells the brain when the body needs to eat and
when it has eaten too much. It also plays a role in the reproduction
process. Women with very little body fat, such as anorexics, do not have
periods. Simon Coppack said body fat can contribute to a healthy pregnancy.
“If you went into a pregnancy malnourished, that would be catastrophic for
both baby and mother”, he says.
February 2002, Health Action
Ten medical school in US take to Ayurveda
yurveda the ancient Indian system of
medicine, will be taught as a short-accredited course in ten US medical
schools by the end of 2002.
Measures to popularize Ayurveda was discussed
recently by Indian Health Secretary Shailaja Chandra and Joana Rosario,
Director, National Centre for Complementary and Alternative medicine,
Maryland, U.S.
The Ayurveda course will be taught under the
auspices of the National Institute of Health in Maryland.
Teachers
of Ayurveda system of medicine in India will be sponsored by their
government to visit the Us in January 2002 and present model of the
accredited course in Ayurveda at the NIH.
According to the recent deliberations,
ayurvedic and herbal medicine would be introduced and promoted in the US
where alternative medicine has a big $27, billion market.
“A
lot of research carried out in the West has proved Ayurveda to be effective
in finding a cure for certain psychiatric diseases, arthritis,
Alzheimer’s, diabetes, dysentery and skin ailments.” Said Navin Shah, a
noted urologist of Mary land. Herbal medicines, he said, are becoming very
popular in the US because allopathic drugs are expensive and have several
side-effects.
February 2002, Health Action
New anthrax medicine
cientist in India have created a new
vaccine for anthrax, which they say could be less toxic and more effective
than the one that is currently available. The alternative has been developed
by a team from the Centre for Biotechnology at the New Delhi-based
Jawaharlal Nehru University. It is made up of harmless mutant forms of three
key proteins that together make the toxin that does the damage to humans.
Rakesh Bhatnagar, who led the research team, says the laboratory testing of
the new vaccine has been completed and it would now be subjected to animal
and human trials.
December 15, 2023 Down To Earth
Garlic, remedy for cold
arlic can help alleviate the misery of
the common cold, say scientists who discovered an active ingredient in the
plant which reduces symptoms like sneezing, coughing and a runny nose and
speeds up recovery. The substance also slashes the chance of being
re-infected with a new cold by boosting the immune system. Writing in the
journal Advances in Therapy, the
researcher say allicin, a compound from the garlic bulb known to fight bacteria,
may be a ‘cure’ for the debilitating common cold.
December 2001, Health Action
Nuclear receptor has a role in wound healing
wiss researchers have uncovered a
protein involved in the response to skin injury that helps elucidate the
molecular mechanism and genetics of wound healing, and might lead to
identification of targets for the development of new treatments for skin
disorders.
Walter Wahli and colleagues had previously found that a nuclear
receptor protein, peroxisome proliferator-activated receptor b
(PPARb), is a critical gene
regulator in the cellular response to inflammation, and in differentiation
and migration of keratinocytes in the epidermis.
It has been demonstrated
that the stimulation of the PPARb
gene and then the activation of the PPARb protein
are required in wound healing thereby suggesting that healing defects may
arise from a lack of PPAR gene
expression, or a default in PPAR protein activation, or both combined”,
says Wahli. The investigators also suspect that PPARb
dysfunction could be one of the molecular mechanism underlying psoriasis,
since keratinocyte differentiation induced by inflammation is impaired in
psoriasis.
Wahli suggests that drug
therapies could be developed that accelerate the healing of surgical wounds
and diabetic ulcers by inducing the PPARb
gene or activating the PPARb
protein. Drugs could also be designed to inhibit PPARb
gene expression and PPARB protein activity
to address diseases with an underlying overexpression of PPARb.
Further research will hopefully
identify the genes targeted by PPARb
and explain how this mechanism might apply to other tissue in which PPARb
is expressed.
Theodora Mauro (University of
California at San Francisco, CA, USA) is more sceptical about the findings.
“A previous study using a PPARb
activator improved psoriasis by decreasing keratinocyte differentiation,
suggesting that this receptor stimulates differentiation, not
proliferation”. Unfortunately, says Mauro, the proliferation of
keratinocytes is necessary, at least in the early stages of the wound
repair. She also asks whether PPARb could function in wound healing without PPARa
“It seems as if many of the functions ascribed to PPARb
[anti-inflammatory, pre-differentiative] would hinder not help wound
healing, and that PPARa may be
directing the timing of PPARb
activities for later in the wound healing process”, she says.
December 15,2023 The Lancet Vol. 358
Raised triglyceride concentration is an independent risk for stroke
esearchers in Israel report this week
that a high blood triglyceride concentration is an independent predictor of
stroke in people with coronary heart disease (CHD). “This is the first
large study to provide strong evidence that elevated blood triglyceride
levels, independent of cholesterol levels and its fractions, can predict the
occurrence of stroke among patients already suffering from heart disease”,
asserts lead researcher David Tanne.
Tanne and colleagues followed-up 11 177
people who had CHD, but no history of stroke or transient ischaemic attack (TIA),
for 6-8 years. Of the 941 individuals who developed cerebrovascular disease
during follow-up, 487 had a verified ischaemic stroke or TIA (circulation
2001; 104: 2892-97). “We found that those with high blood triglycerides
[> 200 mg/dL] have a nearly 30-50% higher risk of suffering an ischaemic
attack or TIA, after controlling for well established risk factors for
stroke such as high blood pressure, cigarette smoking, or diabetes”, Tanne
told The Lancet. The researchers
also found that people who had a stroke also had lower concentrations of
high-density lipoprotein (HDL) cholesterol.
“This is well-conducted study
that sheds new light on the relationship of lipids and stroke”, comments
Ralph Sacco (Neurological Institute, New York, NY, USA). “Unlike heart
disease, the relationship between stroke and cholesterol has not been as
clear. New data such as this study provide a stronger link between stroke
and lipids.”
Sacco, who has
previously shown that HDL cholesterol is a protective factor for stroke in
elderly people, suggests that clinicians need to focus more on the control
of lipids as an important modifiable risk factors for stroke.
Tanne agrees with this view
and suggests that clinicians should measure triglyceride concentrations as part of their global
risk factor assessment of stroke in all individuals. “Although measured as
part of a lipid profile, triglycerides are not given sufficient attention
for stroke prevention by practitioners. Triglyceride concentrations may help
to refine the risk of ischaemic stroke.”
Tanne stresses,
however, that further studies are needed to determine whether there is a
similar relation between triglyceride concentrations and stroke in people
without CHD, and also whether lipid-lowering drugs or drug combinations can
help prevent stroke in patients with raised triglyceride concentrations.
December 15, 2023
The Lancet Vol. 358
COX 2 inhibitors may increase risk of heart attack
reatment with certain COX 2 inhibitors,
non-steroidal anti-inflammatory drug that relieve the pain associated with
arthritis, may increase the risk of heart attack according to a
retrospective analysis of two separate marketing studies.
The research comes within weeks of the National Institute for
Clinical Excellence approving these types of drug for use in the NHS in
England and Wales. The institute acknowledgement in a recent technology
appraisal guidance bulletin that there is a such a risk and that COX 2
inhibitors should not be prescribed routinely to patients with
cardiovascular disease.
Researchers from the Cleveland Clinic Foundation in Ohio analyzed the
cardiovascular event rates in two randomized multicentre trials. They also
looked at myocardial infarction rates in the placebo group (23407 patients)
in a meta-analysis of four large aspirin studies.
They found that the annual myocardial infarction rate in the aspirin
placebo group was 0.52%. This compared with 0.74% (P=0.04) for the COX 2
inhibitor rofecoxib (Vioxx) in the Vioxx gastrointestinal outcomes research
(VIGOR) study and 0.80% for the inhibitor celecoxib (Celebrex) in the
celecoxib long term arthritis safety study (CLASS).
Aspirin use was not permitted in the VIGOR study, in which 8076
patients were randomized to receive rofecoxib 50mg a day or naproxen 1000 mg
a day. There were 111 cardiovascular events in the rofecoxib arm and 50
events in the naproxen arm.
September 1, 2023 BMJ.
Vol. 323
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