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- Ovary
gene may explain certain aspects of infertility
Harvard Medical School researchers have uncovered an ovary
gene whose absence from mouse egg cells produced severe
pregnancy complications. The gene, Fmn2, which produces
the protein formin-2, is similar in mice and humans and
offers promise for understanding embryo loss, birth defects,
and infertility in women. The study appears in the December
Nature Cell Biology.
- Study
Helps Explain Gene Silencing In The Developing Embryo
- First
biologic pacemaker created by gene therapy in guinea pigs
Working with guinea pigs, Johns Hopkins scientists have
created what is believed to be the first biologic pacemaker
for the heart, paving the way for a genetically engineered
alternative to implanted electronic pacemakers.
The advance, reported in the Sept. 12 issue of Nature, uses
gene therapy to convert a small fraction of guinea pigs'
heart muscle cells into specialized"pacing" cells.
- Evidence
that adults stem cells differentiate like embryonic stem
cells published in Nature
Researchers at the University of Minnesota Stem Cell Institute
(SCI) have found the first evidence that adult bone marrow-derived
cells can differentiate in vitro and in vivo into cells
of all three embryonic germ layers (endoderm, ectoderm and
mesoderm) in similar manner as embryonic stem cells (ES
cells). SCI Director Catherine Verfaillie, M.D., and her
colleagues call these cells multipotent adult progenitor
cells (MAPCs).
- Embryonic
mouse stem cells reduce symptoms in model for Parkinson's
disease
Embryonic mouse stem cells transformed into neurons in a
lab dish and then transplanted into a rat model for Parkinson's
disease (PD) form functional connections and reduce disease
symptoms, a new study shows. The finding suggests that embryonic
stem (ES) cells may ultimately be useful for treating PD
and other brain diseases.
- 11 January
2002: PROTEOMICS:
Enhanced: Integrating Interactomes, abstract, Science
- 11 January 2002: GENETICS:
Do X Chromosomes Set Boundaries?, abstract, Science
- 11 January 2002: STEM
CELL RESEARCH: Stem Cells May Shore Up Transplanted Hearts,
abstract, Science
- France
challenges patent for genetic screening of breast cancer
The Institut Curie, France's top centre for research,
diagnosis, and treatment of cancer, is challenging the patent
awarded by the European patent office to the US company
Myriad Genetics, of Salt Lake City, Utah, for a test to
screen for predisposition to breast cancer.
- New
System For Transplanting Clusters Of Brain Cells
Bioengineers at Cornell University have demonstrated a system
for transplanting clusters of brain cells, together with
controlled-release microcapsules of protein, to enable cell
differentiation and growth.
- Language
gene found
The first linking of a gene to language could speed our
understanding of this most unique and most controversial
of human abilities.
- US
heads for total ban on human cloning
The US House of Representatives voted by a wide margin on
Tuesday for a total ban on human cloning. The ban covers
not only cloning, but also cloning human embryos for medical
research and "therapeutic cloning", which allows
the harvesting of cells from embryos to treat disease.
- Patents,
Secrecy, and DNA
In this policy forum, Cook-Deegan
and McCormack urge that DNA sequence information contained
in patents be made publicly available soon after patent
applications are filed.
- Can
Genes Explain Biological Complexity?
When it comes to the complexity of organisms we immediately
think of behavioral or morphological complexity or perhaps
wish to count the number of cells in an organism or the
number of genes in the organism's genome. As Szathmary
et al. explain in their Perspective, biological
complexity is not that simple. With the completed sequences
of yeast, worm, fly, and human at hand, it is now clear
that the number of genes cannot account for the complexity
of organisms (the fly genome has about 25,000 genes and
we only have about 35,000). The Perspective authors discuss
whether we should think about complexity in terms of interactions
among gene-regulation networks, using equations similar
to those used by ecologists to determine the multitudinous
interactions within food webs.
- New
Genomes Shed Light on Complex Cells
At a genome sequencing and biology meeting last week, researchers
announced that they have decoded the genetic complement
of fission yeast and are in the midst of sequencing two
fungi. By determining which genes the varied eukaryotic
organisms sequenced to date have in common and removing
those that are also shared by prokaryotes, researchers have
identified the subset of genes that make possible the more
complex cell functioning of eukaryotes.
- BRCA2
gene plays previously unsuspected role in cell division.
- Scientists
isolate premature ovarian failure gene
A genetic mutation appears to produce eyelid defects in
newborns and trigger early onset of menopause decades later.
The finding could help researchers decipher how genetic
processes during fetal development can have immediate manifestations
at birth and also lead to certain age-associated changes
later in life.
- New
evidence of mammals' origins
- Scientists
have found that nearly half of all genes related to
the earliest stages of sperm production reside not on the
male sex (Y) chromosome, but on the X chromosome, raising
the possibility that infertility due to low sperm production
may be X-linked, passed on to sons through their mothers.
- Gene
Linked to Repeat Miscarriage
Variations in an inflammation-related gene may explain why
some women have recurrent miscarriages, according to an
Austrian study.
- Science
and medicine
When sperm meets egg.
- Artificial
Chromosomes Coming to Life
"One of the biggest obstacles to gene therapy is the delivery
of the therapeutic gene to the target tissue so that it
is appropriately expressed. The potential advantages of
using a human artificial chromosome to maintain expression
of a therapeutic gene and the hurdles yet to be overcome
before this gene delivery system can be tried out in the
clinic..."
- Liver
stem cells ; future liver regeneration via cellular therapy
After studies spanning more than a decade, scientists at
the University of North Carolina at Chapel Hill have become
the first to identify and purify hepatic stem cells, progenitor
cells capable of regenerating liver and bile duct tissue."
- US
and UK governments approve stem cell research
- New
link between DNA replication and 'silent' chromosome architecture.
- "New
Clues to How Genes Are Controlled"information about
how the transcription factor called Pit-1, which is needed
to activate the genes for three different hormones, manages
to turn on the right gene without activating the other two..."
- Proteins
Can Transmit Heritable Traits
"...the discovery of a protein that transmits a genetic
trait, a finding that hints at the presence of a menagerie
of undiscovered protein-based "genetic elements" that may
have driven evolution without the need for mutation of DNA
genes".
- Stem
cell technology. Where are we going?
- Microarray
Analysis of Drosophila Development During Metamorphosis
DNA microarray technology allows researchers to visualize
the expression of thousands of genes simultaneously. A team
at Stanford has now used DNA microarray technology to characterize
the changes in gene expression that take place during the
fruit fly Drosophila's metamorphosis to full adulthood.These
results could pave the way for the use of microarrays in
the study of complex genetic events in higher organisms,
including humans.
- Science
Magazine
17 December 1999: BREAKTHROUGH OF THE YEAR:
Capturing the Promise of Youth "Late last year, in a technological
breakthrough that triggered a burst of research and a whirlwind
of ethical debate, two teams of researchers announced that
they had managed to keep embryonic and fetal human cells
at their maximum potential, ready to be steered into becoming
any cell in the body. Building on that achievement, in 1999
developmental biologists and biomedical researchers published
more than a dozen landmark papers on the remarkable abilities
of these so-called stem cells. We salute this work, which
raises hopes of dazzling medical applications and also forces
scientists to reconsider fundamental ideas about how cells
grow up, as 1999's Breakthrough of the Year."
- Molecular
Classification of Cancer: Class Discovery and Class
Prediction by Gene Expression Monitoring.
- The
Promise of Comparative Genomics in Mammals.
- CHEERS!!!!!
Historical Genetics: The Parentage of Chardonnay, Gamay,
and Other Wine Grapes of Northeastern France. [summary
- can be viewed for free once registered]
- The
evolution of the sex chromosomes: step by step.
- September
1999: Learning how organs tell left from right, press release,
Nature.
- September
1999: Ethical Issues in Human Stem Cell Research, National
Bioethics Advisory Commission (NBAC).
- Genetic
benefits enhance the success of polyandrous females,
Proceedings of the National Academy of Sciences.
- Pesticide
exposure and decreased fertilisation rates in vitro,
The Lancet.
- Older
mothers, older fathers
Source: American Journal of Obstetrics and Gynecology 2003;
189: 901-5
Women aged 35 or more have long been known to have an increased
risk of infertility. But does advancing age in the male
partner have similar effects?
The results of previous studies in this area have been conflicting.
To investigate the risk of infertility associated with paternal
age, researchers from the Human Fertility Research Group
at Paule de Viguier Hospital in Toulouse, France, interviewed
3,287 couples in which both partners were within the range
25-44 years.
- Does
paternal age contribute to infertility?
Source: American Journal of Obstetrics and Gynecology 2003;
189: 901-7 Investigating the impact of
the age of the male on fertility in a large European database.
Once men reach the age of 40 years they become a risk factor
for infertility, say researchers. Whereas a maternal age
of 35 years of age and above is a well-known risk factor
for infertility, the impact of the age of the male has been
rarely investigated, note Patrick Thonneau (Paule de Viguier
Hospital, Toulouse, France) and co-workers.
- Primates
successfully give birth following ovarian cryopreservation
The first successful birth following ovarian cryopreservation
in a primate model was reported at the XVII FIGO World Congress
in Santiago, Chile (2-7 November 2003).
Researchers have reported the first successful birth following
ovarian tissue cryopreservation in a monkey. But they stress
the research remains technically challenging at the current
time.
- PGD
reduces recurrent miscarriage abortion rate
A study presented at the XVII FIGO World Congress that was
held in Santiago, Chile (2-7 November 2003) shows that less
than one-third of embryos generated from recurrent miscarriage
couples are normal.
Preimplantation genetic diagnosis (PGD) may have a role
to play in the diagnosis and management of patients with
recurrent miscarriage, according to Spanish researchers.
- First
human ovarian transplant reported Indian gynecologists
reported the first successful ovarian transplant in humans
at the XVII FIGO World Congress held in Santiago, Chile
(2-7 November 2003).
A patient with Turner’s syndrome has been successfully transplanted
with an ovary from her living sister, said Dr. Parvin Mhatre
(Kothari Hospital, Mumbai, India). The transplant was carried
out from a live donor, who was 26 years old and had two
children herself, to her younger sister, aged 17 years,
in March 2002.
The recipient had bilateral streak ovaries and chromosomal
configuration of XO—Turner’s syndrome. The donor and recipient
were immunologically matched by blood group, HLA matching,
and lymphocytic cross matching.
- Sex
ratio at conception shows seasonal variation
Seasonal patterns of conception may help preserve the male
to female sex ratio.
Couples who want to have a boy should try to conceive in
autumn, while the chances of having a girl are increased
by conceiving in spring, study findings indicate.
Given that male fetuses and neonates are more fragile than
females, the study authors believe that the seasonal variation
helps to preserve the sex ratio, by allowing more boys to
be conceived during optimal conditions for pregnancy and
birth.
- Egg-sharing
does not damage a donor’s own chance of a baby say UK researchers
Women who take part in egg sharing programmes run by fertility
clinics are not compromising their chance of having a baby
by donating some of their eggs, according to UK research
published today (Thursday 30 October) in Europe's leading
reproductive medicine journal Human Reproduction[1].
- Danish
study finds that taking a long time to conceive is linked
to problems at birth.
Women who take more than a year to conceive have a higher
than normal risk of having a premature birth, a full-term
baby with low birthweight[1], or a Caesarean section, according
to a large Danish study reported (Thursday 30 October) in
Europe's leading reproductive medicine journal Human Reproduction[2].
- Fever
impact on semen quality confirmed
Testing the validity of claims that semen quality is affected
by febrile illness. Semen quality may be impaired by the
development of a fever up to 2 months before ejaculation,
study findings suggest.
Although previous publications have stated that "it is a
well-known phenomenon that semen quality can be affected
by febrile illness," the data supporting this claim are
of low quality, note Elisabeth Carlsen (Rigshospitalet,
Blegdamsvej, Denmark) and colleagues.
To address this issue, the researchers examined the influence
of febrile episodes on monthly sperm samples of 27 healthy
men, over a 16-month period. htt
- HPV
and p53 inversely correlated in genital tract tumors
Correlating human papillomavirus positivity with p53 over
expression in cervical, vaginal, and vulvar squamous cell
carcinomas. The overexpression of p53 and human papillomavirus
(HPV) infection may reflect independent carcinogenic processes,
say researchers.
While "one well characterized pathway for the induction
of growth arrest and apoptosis is through the activation
of the p53 tumor suppressor protein," human papillomavirus
appears to abrogate this response by targeting the tumor
suppressor for ubiquitin-dependent degradation.
Consequently, it has been suggested that p53 mutations play
a role in HPV negative carcinomas, although evidence of
an inverse relationship between the presence of HPV DNA
and mutant p53 expression is conflicting, explain Yasuko
Koyamatsu (Saga Medical School, Japan) and co-workers.
- ** Fertility
first with tissue transplant **
US scientists use ovarian tissue to produce a live monkey
birth, a move which could benefit women made infertile by
cancer treatment.
The procedure carried out in a rhesus monkey could, researchers
say, be used for humans. The development gives new hope
to women who have become infertile following cancer treatment.
- New
technique allows real-time placenta imaging
Researchers recommend a new imaging technique for staging
human placental development.
Using a new imaging technique, it is now possible to monitor
placental development during pregnancy, reveal researchers
in a finding that holds promise for the real-time diagnosis
of placental pathologies.
"Maldevelopment of placental villous trees and their blood
vessels results in impaired fetal growth, which can greatly
compromise fetal, neonatal, childhood, and adulthood health,"
write Justin Konje (University of Leicester, UK) and colleagues.
However, "there are no means of directly assessing such
maldevelopment."
- First
trimester trisomy screening supported
Researchers test the sensitivity of a combined approach
to first trimester screening for the detection of trisomies
18 and 21.
First trimester screening combining biochemical markers
and fetal nuchal translucency for the detection of trisomies
21 and 18 is an accurate and efficient alternative to second
trimester screening, say researchers.
- Perimenopausal
depression linked to ovarian function
Examining the relationship between changes in mood and pituitary-ovarian
axis function in perimenopausal women.
A normal dietary intake of isoflavones is linked to lower
levels of total body fat in postmenopausal women, and may
prove useful for the prevention of chronic disease.
"Previous studies suggest an association between isoflavone
supplementation and improved body composition," write Deborah
Goodman-Gruen and Donna Kritz-Silverstein from the University
of California in San Diego, USA. However, "the effect of
usual dietary isoflavone consumption on obesity among postmenopausal
women consuming a typical Western diet," has not been reported.
- Oxidative
stress linked to infertility apoptosis
Investigating whether semen quality is associated with apoptosis
in the presence of oxidative stress. High levels of reactive
oxygen species (ROS) in the semen of patients with male
factor infertility are associated with increased levels
of caspase-mediated apoptosis, a study shows.
While both oxidative stress and high rates of apoptosis
have been independently associated with testicular insufficiency
in male infertility, "it is unclear whether the caspase-mediated
pathway is involved in inducing apoptosis in ejaculated
spermatozoa, and, if so, how it is influenced by oxidative
stress," write researchers, led by Xia Wang from the Cleveland
Clinic Foundation in Ohio, USA.
- Iron
supplementation improves birth weight
Scientists hypothesize that prophylactic iron supplementation
in early pregnancy reduces anemia and increases birth weight.
Results from a randomized controlled trial suggest that
prenatal prophylactic iron supplementation in iron-replete,
nonanemic women improves birth weight, and may have beneficial
effects on related health care costs.
- IVF
and ICSI synergy in unexplained infertility
Researchers further examine the value of splitting sibling
oocytes from patients with unexplained infertility between
IVF and ICSI.
- The
International Federation of Gynecology and Obstetrics (FIGO)
has published its World Report on Women's Health 2003, in
a special issue of its journal.
The report consists of a series of articles providing commentary
on a wide range of issues that impact on women's health,
highlighting new developments and initiatives that are leading
to real improvements in care.
- Sex
selection for social reasons: religious and moral perspectives
Two reports in the 25 September 2003 issue of Human Reproduction
suggest that the coming availability of sex selection technology
is not likely to skew the balance between the sexes.
Two experts in religion and reproductive technology respond
to this report and to the way it might be used in the ethics
and public policy debate over the availability of sex selection
technology.
- Fetal
exposure to two chemicals cause of male reproductive disorders
later in life
Primary author of several recent studies involving di-n-butyl
phthalate (DBP) and linuron (L) discusses his findings and
what they mean for understanding human development. (Philadelphia,
PA) – Over the last ten years, US researchers have observed
a marked increase in some male reproductive disorders, including
undescended testicles, increased instances of testicular
cancer, and decreased sperm count.
In the last 20 years the rates for testicular cancer have
grown almost five-fold in Denmark, yet neighboring Finland
has not experienced such a dramatic increase.
In an effort to explain this phenomenon, scientists have
hypothesized that these human male reproductive deficits
may have a common origin: a disturbance in the level of
androgen and other critical hormones during fetal development.
The results from tests with laboratory animals may help
scientists better understand the effect of fetal exposure
to certain chemicals has on male reproduction abilities
later in life.
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