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New
In Vitro Fertilization (IVF) Gold Standard Declared
At a recent
conference in Montreal/Canada about "Measuring Human Embryo
Quality" several IVF research groups exchanged the latest on
single embryo transfer, which has become the standard for in
vitro fertilization.
These techniques are important for treating infertile couples.
In the past
an in vitro fertilized egg was implanted into the woman's
uterus, but the success rate of a normal pregnancy was extremely
low (in the order of 15% to 20%).
Subsequently
more than one fertilized egg was implanted to improve the success
rate, but this led to twins, triplets and multiple pregnancies with
a high complication rate and death due to premature deliveries.
Subsequently it was found that the success rate was much higher
after a few cell divisions, which were allowed to take place outside
the uterus in vitro cultures. Dr. William Schoolcraft (director
of the Colorado Centre for Reproductive Medicine at a private clinic
in Englewood, Col.) reported that embryos that were cultured for
5 days until the blastocyst stage in vitro are much more
stable for implantation.
For the past
5 to 6 years they and other groups have only employed this technique,
which according to him is now the gold standard. Although they were
largely still using two embryos for transfer into the uterus for
IVF. It has become increasingly clear that the risk of twin pregnancies
in these already high risk situations is ranging from 4- to 10-times
the risk of a single embryo transferred (singleton) into the uterus.
Because of this his group has decided to only do singleton transfers.
The other new finding is that it matters tremendously what culture
medium is used for incubating the fertilized egg for the 5 day period
in culture and what the exact conditions are. They found that for
optimal results they have to use two different growth media, the
first 3 days a low glucose or glucose free medium that mimics the
environment of the fallopian tube. On day 4 and 5 the medium must
mimic the environment inside the uterus, which requires it to be
rich in amino acids and contain glucose.
An embryologist,
Dr. Barry Behr from the Stanford University Medical Centre in California,
reported that the same culture medium is not necessarily suitable
for all patients, but individualization and close observation of
the wellbeing of the embryo and the mother is necessary. To optimize
maximum quality of the embryos growth factors may also have to be
introduced into the culture medium and further research is going
on in this direction.
This report
is based on a summary in The Medical Post , June 24, 2003, page
8.
Here is a useful
link regarding the topic of infertility: Link
to chapter on infertility in my nethealthbook.com
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Report
Says: High Blood Pressure Increasing In The US
Dr. Hajjar,
of the University of South Carolina in Columbia and Dr. Kotchen,
of the
Medical College
of Wisconsin in Milwaukee have compared a large group of people
in the US in the years 1999-2000 with prior studies in 1988-1991and
1991-1994 where peoples' blood pressures were measured.
The latest study
involved more than 5000 people, the prior studies more than 9000
people each. Almost 29% of the population has a blood pressure of
140/90 or higher in the latest study.
Compared to
the 1988-1991study this is a significant increase of 3.7%. More
than half of this was explained on the basis that the population's
weight (measured by body mass index calculation) had increased.
The sub groups who had the largest increase in blood pressure were
as follows:
1. diabetics
with high blood pressure. In this high risk group only about 25%
had a blood pressure readings of less than 130/85, which is the
target value.
2. Mexican Americans
had a significantly poorer awareness and control of their elevated
blood pressures than the non-Hispanic whites and non-Hispanic blacks.
3. Women as
a group were poorer in blood pressure controlling than men.
4. People above
the age of 60 had a much higher rate of uncontrolled blood pressure
as well.
The study concluded
that by concentrating campaigns and efforts on these four target
groups significant gains could be made in terms of control of blood
pressure, reduction of strokes, heart attacks and kidney damage.
Here are some
links regarding high blood pressure and prevention of strokes and
heart attacks to various chapters of my nethealthbook.com:
High
blood pressure link.
Heart
attack link.
Stroke
link.
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Food And
Mood
"Food affects
your mood" is the heading of an article by Dr.Susan Biali (practising
family physician with a degree in dietetics) in the June 24, 2003
edition of The Medical Post (page 24). According to her there is
good evidence in the medical literature to indicate that a number
of biologically active brain hormones depend on what we eat. There
are 5 major items that she pointed out, which I summarized below
in tabular form.
| Brain
food components that affect your mood |
| Food
item: |
Comments: |
| omega-3-fatty
acids |
Chinese
and Taiwanese eat much more of these and have 10 times less
depression than North Americans |
| DHA,
a long-chain omega-3-fatty acid |
our
daily intake is 100mg less per day than 50 years ago due to
our diet being based on commercial livestock; lack of DHA leads
to depression |
| too
much omega-6-arachidonic acid in "junk foods" |
ratio
of omega-6 to omega-3 arachidonic acid has increased from fast
food consumption; this leads to depression |
| folate
and Vit.B12 |
deficiency
associated with depression |
| tryptophan
|
an essential
amino acid that is needed to make serotonin, a brain hormone
without which we experience depression |
The medical
literature points to the importance of these various food factors
to allow us to have a balanced brain metabolism. When these ingredients
are present our mood is more likely to be normal with more resilience
to depression.
The literature
centers around various population groups in comparison with the
North American population. For instance, in an article of the Dec.
2000 issue of Psychiatric Clinics of North America a study was reported
that found that Taiwanese and Chinese people consume a lot more
omega-3 fatty acid rich foods such as fish than North Americans.
In the same
study the rate of major depression was found to be 10-times more
frequent in North Americans and the investigators felt that this
was so because of the brain hormone stabilizing effect of the omega-3
fatty acids. Other researchers suggest that chronic stress might
lead to a depletion of omega-3 fatty acids in the brain through
an oxydation process, which eventually results in depression.
Several nutritional
factors appear to have caused deficiency states of essential brain
nutrients, one being the junk foods like candy bars, French fries,
hamburgers etc. leading to a dysbalance of the omega-6 fatty acid
to omega-3 fatty acid ratio. Another factor is the increase of consumption
of highly refined carbohydrates (sugar
and starch), often also called high glycemic foods. This is known
to lead to the metabolic syndrome, also called syndrome of insulin
resistance. Finally many people still have too much fat in their
diets with a high amount of hydrogenated vegetable oils (see link).
It is also important to note that folate,
Vit. B6 and Vit.B12 are required for prevention of hardening of
the arteries by lowering homocysteine levels.
So what is "brain
food" ? Dr. Biali pointed out in her article that it is always
best to start with a low fat, well balanced food plan where junk
foods are avoided and where vegetables and fruit provide the low
to medium glycemic index carbohydrates. Fish should be eaten at
least three times per week to provide the brain with the essential
omega-3 fatty acids.
It is probably
not recommendable to take tryptophan as a supplement: in 1989 several
fatalities occurred from impurities in commercial tryptophan and
many researchers are concerned about dysbalancing the network of
brain hormones by giving an overdose of only one amino acid, but
not giving enough of the others. It is much safer to simply eat
enough protein (meat, soy protein, milk products) and the body can
pick and choose what it needs in terms of amino acids including
tryptophan. With folates one needs to be careful not to exceed 0.8
mg per day as with mega-doses of folate in the 15 mg range toxic
symptoms of vivid dreams, disturbed sleep patterns and even occasional
seizures developped. A good multivitamin supplement will not only
provide the right folate dose, but also Vit. B12, which is also
needed to prevent depression.
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Obesity
And Metabolic Syndrome
In the June
10, 2003 edition, following page24, of The Medical Post there was
a minisymposium on obesity and the metabolic syndrome (also known
as the "syndrome of hyperinsulinism").
Four specialists
had a discussion about this topic: Dr. Ehud Ur (endocrinologist,
Dalhousie University, Halifax, N.S., Canada), Dr. Robert Dent (Director
of the Weight Management Clinic, Ottawa Hospital, Ont.), Dr. Dominique
Garrel (Director of Department of Nutrition and endocrinologist,
University of Montreal, Quebec), and Dr. Arya Sharma (Prof. of Medicine,
McMaster University, Hamilton, Ont.).
Introduction:
Obesity is now
a health threat that about 25% of the North American population
is suffering from. There is still a lot of discussion what the exact
criteria should be, but the Third Report of the National Cholesterol
Education Program Expert Panel on Detection, Evaluation, and Treatment
of High Blood Cholesterol in Adults (ATP III) has simplified the
detection of the metabolic syndrome.
| Elements
leading to the diagnosis of "metabolic syndrome" |
| Finding: |
Comments: |
| abdominal
obesity |
waist
circumference more than 102 cm in men or more than 88 cm in
women |
| elevated
triglyceride level |
level
of 150 mg/dl or higher |
| low
HDL cholesterol level |
under
40 mg/dl in men or under 50 mg/dl in women |
| elevated
blood pressure |
systolic
or diastolic blood pressure exceeding 130/85 mm Hg |
| high
fasting blood glucose level |
fasting
glucose higher than 110 mg/dl |
The experts
agree that when three or more of the criteria mentioned in
this table are positive the person would be considered to have metabolic
syndrome.
There is a wide
age-related variety: in one study only 7% had metabolic syndrome
in the age group of 20 to 29. The same study found 40% of study
participants had the metabolic syndrome in the age group of 70 years
and older. It is thought that too many calories coupled with too
little activity over a longer period of time, perhaps coupled in
some people with a genetic tendency to develop metabolic syndrome,
leads to an accumulation of abdominal (so-called"visceral")
fat.
Because fat
cells have their own hormone systems (leptins
etc.) there is a change of metabolism including an elevation of
the insulin level with associated loss of "insulin sensitivity".
So, the more obese a person becomes, the less effective insulin
becomes in transporting blood sugar through cell walls. At the same
time the liver metabolism is changing with the good cholesterol
(HDL) being less produced and the bad cholesterol (LDL) being overproduced.
The liver will produce a different mix of coagulation factors, which
leads to a tendency to form clots in the veins of the legs and in
the lungs. As the pancreatic capacity for insulin production gets
exhausted over a period of time, the patient eventually develops
type 2 diabetes mellitus. Due to the risk of the coronary arteries
clogging up with the cholesterol changes and the accelerated hardening
of arteries from diabetes, the risk for getting severe heart attacks
in obese people with the metabolic syndrome when compared to a normal
weight population is about 4-fold.
Treatment
of metabolic syndrome:
The experts
agreed that a reduction of only 5% to 10% of the body weight through
a sensible combination of a mild exercise program (e.g. walking
30 to 45 minutes every day) and a calorie reduced food intake will
make a significant difference in terms of normalization of the body
chemistry. It is my estimate that perhaps 70% to 90% of all cases
of obesity and metabolic syndrome can be treated this way.
However, the
remaining cases should continue to see their physician and be followed
like the doctor would follow someone who has high blood pressure.
There are two types of medications available and they have nothing
to do with the Phen-Fen diet pills from not too long ago that were
found to cause pulmonary hypertension. These new diet pills are
fairly safe and show weight loss results provided the patient co-operates
with regard to a modified to low fat diet and some degree of regular
exercise.
1. Sibutramine
(brand name: Meridia) is a specific brain hormone
inhibitor in the area where the appetite zone is located (serotonine
and norepinephrine reuptake inhibitor). This medication helps the
patient by experiencing satiety sooner so that the patient does
not feel deprived despite less calorie consumption.
It is the medication
of choice for those who tend to eat a lot. Like with other anti-depressants
side-effects are a dry mouth, heart rate increases and sleep loss
(insomnia).
2. Orlistat
(brand name: Xenical) inhibits fat uptake
at the level of the gastrointestinal wall (gastrointestinal lipase
inhibitor). This leads to an inhibition of fat absorption by about
30%. The patient needs to keep the fat intake down to about 2 oz.
(=60 gm) per day. If the patient consumes more fat, the side-effect
of orlistat will be flatulence, abdominal cramps and diarrhea. If
the patient is on a strict low fat diet, there would not be enough
fat in the gut for the medication to be effective.
At this point
it is not known how long the patient should be on such weight loss
medication, if this was the chosen route. The experts felt that
1 year would be reasonable, but that the patient should be observed
by the treating physician and it may be necessary after some intermission
to go for another year of therapy all the way attempting to permanently
change eating and exercise habits as an ongoing maintenance program.
Here is a link
to another reference about the metabolic
syndrome (syndrome of insulin resistance).
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Beware
Of Binges
In the June
16, 2003 issue of Time (page 73) an article appeared under the heading
"Summertime booze". A study from the Buffalo University
showed that women, in particular, have to be conscious that drinking
3 or 4 drinks at one time on the weekend is not the same as drinking
the same 3 to 4 drinks over the course of one week.
A study looking
at the frequency of breast cancer in relation to drinking patterns
found that the binge drinking women had a 80% higher breast cancer
risk than the controls who drank 3 to 4 drinks at a time (but only
one drink per day). Jo Freudenheim, the epidemiologist involved
in this study, suggested that perhaps with the binge drinking alcohol's
toxic potential for breast cancer cells had been reached whereas
with one drink at a time over one week this level was never encountered.
In another study
from the Buffalo University liver toxicity as a result of alcohol
exposure was examined. These researchers used blood tests to measure
liver enzymes, which were leaking from the liver cells as a result
of the toxic effect of alcohol. Both men and women were tested and
various drinking patterns were also studied. Men who drink several
drinks daily had the highest liver enzyme counts (reflecting the
toxic effect of alcohol on the liver). However, women who drink
only on weekends had even higher counts of the liver enzymes than
men! Women who drank on an empty stomach had much higher liver enzymes
in these studies than men where this effect did not show (with men
it did not matter whether they drank with food or on an empty stomach).
The researchers concluded that binge drinking appears to affect
women more than men. Generally speaking the higher the amount of
alcohol consumed, the more toxic the effects on body cells and on
the liver. Moderation may be in order.
Comments:
These
type of studies are particularly important in view of the fact of
marketing techniques of the wine industry. Wine and alcoholic beverages
are being protrayed as being a good source of bioflavonoids that
are lowering cholesterol and would prevent or postpone heart attacks.
Some of the data on cancer indicates that for ovarian cancer and
colorectal cancer there may not be a safe low dose as even one drink
per day can have a measurable effect on cancer risk. On the other
hand, bioflavonoids are abundantly present in raw vegetables and
fruit, so there is no panic about not getting enough heart attack
preventing foods. Finally, a bit of common sense does not harm:
alcohol is a cell toxin, so it should be diluted (nothing stronger
than wine) and if you desire a drink, use it in moderation.
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