Category Archives: Human Reproduction

30-05-2012 05:35 Suvarna News 24X7 - 29 May 2012 In the human reproductive process, two kinds of sex cells, or gametes, are involved. The male gamete, or sperm, and the female gamete, the egg or ovum, meet in the female's reproductive system to create a new individual. Both the male and female reproductive systems are essential for reproduction.

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The United Nations hosted its first-ever high-level panel on violence and discrimination based on sexual orientation and gender identity in early March. Convened by the government of South Africa, some, including me, would argue that this event is at least 10 years overdue. Nonetheless, seeing Ban Ki Moon, the Secretary General of the U.N., in an opening video statement uneqivocally offer his support in this struggle was extraordinary:

I've been doing LGBT human-rights work for two decades, and this was probably the "gayest," or certainly the most theatrical, U.N. moment I've encountered. As house lights lowered within the U.N. Human Rights Council in Geneva, strips of lighting on hundreds of desks in the room cast an eerie florescent glow. The ceiling, a three-dimensional, wildly colored, apocalyptic landscape, was set in emergency-lighting haze as a giant, onscreen Secretary General implored states to address and prevent violations. Pretty moving stuff, actually. With many LGBT- and sexual-rights activists attending from global south and north alike, the Council was duly queered and filled with intrigue.

This event was a landmark within the U.N. system, but it represents a particular win amidst a rollercoaster of to and fro in the political landscape of sexual rights, and specifically sexual orientation and gender identity ("SOGI," as we now call it), within the U.N. The backlash against any "progressive" or feminist focus on sexuality -- including claims for autonomous decision making about sex or reproduction, or sexuality education, or even freedom from discrimination -- is fierce and crosses continents with dizzying speed.

While the SOGI panel was breaking new ground in Geneva, at literally the same time at the U.N. in New York, the Holy See (which functions as a state within the U.N.), conservative governments, and a handful of U.S. right-wing organizations were boldly doing damage at the Commission on the Status of Women, the U.N.'s annual meeting on rights of women. Their goals were tried and true: In government negotiations, promote a monolithic heterosexual notion of "the" family; block promotion of comprehensive sexuality education; weaken any language that could support women's access to abortion or reproductive-health services, and stifle references to "key populations" affected by the AIDS pandemic -- specifically men who have sex with men, or sex workers.

In these spaces of global governance, the resistance to women's and LGBT rights is profound and often revealed in side programming alongside the official negotiations. Back in Geneva, two days after the pioneering SOGI panel, the Holy See hosted a hastily put-together, somewhat veiled anti-gay, unofficial event at the Human Rights Council. Abortion-related rights provide the Holy See's other rallying point, with support of conservative governments and many U.S. right-wing groups. Some of the unofficial U.N. events these groups host are (this can't be said diplomatically) mindblowing: some promote the value of breastfeeding but maintain a main plot that links abortion to breast cancer. For the record, the World Health Organization debunked this connection years ago. These events come across as desperate attempts to roll back the clock or, in this case, the legacy of progressive social movements, scientific evidence-based study, and even international human-rights law. And they're painful to sit through, too.

OK, so that was March in the UN. Bring on April and the U.N. Commission on Population and Development (CPD), another annual, week-long, governmental meeting in New York attended by many sexual- and reproductive-rights and right-wing organizations. Fasten your seatbelts: Here's another swervy ride.

The CPD always has a theme related to health; this year's was "adolescents and youth." Remarkably, the CPD produced a resolution calling on governments to protect human rights of adolescents and youth "to have control over and decide freely and responsibly on matters related to their sexuality, including sexual and reproductive health," and to provide them with "evidence-based comprehensive education on human sexuality." These are big wins that fly in the face of conservative efforts to regulate sexuality of young people. But these gains came with compromises. Gender- and sexual-rights language became lightning rods, because they were seen as "covers" for sexual orientation and gender identity.

So even as an official human-rights panel on sexual orientation and gender identity takes place in one U.N. site, the ideas supporting that work become lynchpins in another U.N. venue 3,000 miles away. And even when allies try to focus on the daily violence and discrimination LGBT people face in all regions, what's heard by those in opposition is entirely different: They hear (because they want to) "demise of marriage," "the ruin of the family," and "the end of child bearing."

There was a not-very-interesting walkout by some governments as the official panel on sexual orientation and gender identity began at the Council. In fact, some of the same delegates who left the room were spotted in the overflow viewing gallery minutes later. Activism lesson: If you're going to stage a walkout, at least leave the building. Their opposition generally rested on weak and manipulated arguments about international law: "Homosexuality is a 'Western import,' is not mentioned in the Universal Declaration of Human Rights, and has no place being discussed in a context of international law," or, "This discussion is about affording 'special rights' to a specific group."

These arguments are, of course, paper-thin. The human-rights framework argues that all people should be able to enjoy all human rights, and that no one should be subjected to violence (including torture, extrajudicial killing, or violence in the home) or discrimination (including arbitrary arrest, or denial of education or health care).

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Cynthia Rothschild: Oh, the Drama! The UN Human-Rights System Tackles Sexual Orientation and Gender Identity

BACKGROUND

DDX3Y (DBY), located within AZoospermia Factor a (AZFa) region of the human Y chromosome (Yq11), encodes a conserved DEAD-box RNA helicase expressed only in germ cells and with a putative function at G1–S phase of the cell cycle. Deletion of AZFa results most often in germ cell aplasia, i.e. Sertoli-cell-only syndrome. To investigate the function of DDX3Y during human spermatogenesis, we examined its expression during development and maturation of the testis and in several types of testicular germ cell tumours (TGCTs), including the pre-invasive carcinoma in situ (CIS) precursor cells which are believed to originate from fetal gonocytes.

METHODS

DDX3Y protein expression was analysed during development in different tissues by western blotting. The localization of DDX3Y in normal fetal and prepubertal testis tissue of different ages as well as in a series of distinct TGCT tissue samples (CIS, classical seminoma, spermatocytic seminoma, teratoma and embryonal carcinoma) was performed by immunohistochemistry.

RESULTS

Germ cell-specific expression of DDX3Y protein was revealed in fetal prospermatogonia but not in gonocytes and not before the 17th gestational week. After birth, DDX3Y was expressed at first only in the nuclei of Ap spermatogonia, then also in the cytoplasm similarly to that seen after puberty. In CIS cells, DDX3Y was highly expressed and located predominantly in the nuclei. In invasive TGCT, significant DDX3Y expression was found in seminomas of the classical and spermatocytic type, but not in somatically differentiated non-seminomas, consistent with its germ-cell specific function.

CONCLUSIONS

The fetal germ cell DDX3Y expression suggests a role in early spermatogonial proliferation and implies that, in men with AZFa deletion, germ cell depletion may begin prenatally. The strong expression of DDX3Y in CIS cells, but not in gonocytes, indicates phenotypic plasticity of CIS cells and suggests partial maturation to spermatogonia, likely due to their postpubertal microenvironment.

Source:
http://humrep.oxfordjournals.org/rss/current.xml

BACKGROUND

An efficient method for cryopreservation of human oocytes may offer solutions to legal and ethical problems in routine infertility programs and may also be used for fertility preservation for medical and social reasons.

METHODS

We conducted an observational longitudinal cohort multicentric study to investigate the efficacy and reproducibility of oocyte cryopreservation outcomes in IVF/ICSI cycles. Moreover, the effects of patient and cycle characteristics on the delivery rate (DR) were analyzed.

RESULTS

In 486 cycles performed in 450 couples, 2721 oocytes were warmed and 2304 of them survived cryopreservation (84.7%). Of the 2182 oocytes subjected to ICSI, the rates of fertilization and development to top-quality embryos were 75.2 and 48.1%, respectively. A total of 128 deliveries were obtained (26.3% per cycle and 29.4% per transfer) for 450 patients (28.4%) and 147 babies were live born from 929 embryos transferred (15.8%). The forward logistic regression analysis on a per patient basis showed that female age [odds ratio (OR): 0.93, 95% confidence interval (CI): 0.88–0.98], number of vitrified oocytes (OR: 1.08, 95% CI: 1.01–1.17) and the day of transfer (OR: 1.97, 95% CI: 1.14–3.42) influenced DR. By recursive partitioning analysis, it can be estimated that more than eight oocytes vitrified are required to improve the outcome (22.6 versus 46.4% DR, respectively). When fewer oocytes are available in women aged >38 years, results are dramatically reduced (12.6 versus 27.5% DR, respectively). Conversely, when >8 oocytes are available, blastocyst culture represents the most efficient policy (62.1% DR; data from one center only).

CONCLUSIONS

Oocyte vitrification is an efficient and reliable approach, with consistent results between centers and predictable DRs. It should be applied routinely for various indications. A predictive model is proposed to help patient counselling and selection.

Source:
http://humrep.oxfordjournals.org/rss/current.xml

BACKGROUND

The use of ovarian stimulation, to stimulate a multi-follicular response for assisted reproduction treatments, may force the production of oocytes from follicles that do not reach optimal maturation, possibly yielding oocytes that are not fully competent. The present study aimed to define the follicular environment and oocyte competence of unstimulated pre-ovulatory follicles, to compare it with that of similar-sized stimulated follicles. For this purpose, we analyzed the follicular hormonal milieu, the oocyte meiotic spindle, the embryo development and the cumulus cells gene expression (GE) profiles.

METHODS AND RESULTS

The study population was divided in two groups: (i) 42 oocyte donors undergoing unstimulated cycles and (ii) 18 oocyte donors undergoing controlled ovarian stimulation cycles (COS). Follicular fluid was analyzed to quantify the concentrations of estradiol (E2), progesterone (P), FSH, LH, testosterone (T) and androstendione (4). T was higher in the COS group, while 4, E2 and LH were significantly higher in unstimulated cycles. The cumulus oophorus cells (CC) surrounding the oocyte were removed and their GE profiles were analyzed with microarrays. There were 18 differentially expressed genes in CC: 7 were up-regulated and 11 were down-regulated in the COS cycles. The microarray was validated by qRT–PCR. The analysis of spindle structure revealed no significant differences between the groups, except for the parameter of length which presented differences. The fertilization ability and embryo morphology on Days 2, 3 and 4 did not show any significant differences between groups.

CONCLUSIONS

The use of ovarian stimulation induces changes in the follicular fluid and in CC GE that may affect immune processes, meiosis and ovulation pathways. Although these differences do not seem to relate to early-stage embryo morphology, the implications of some of the molecules, especially ALDH1A2, CTSL and ZNF33B at the CC level, deserve to be addressed in future studies.

Source:
http://humrep.oxfordjournals.org/rss/current.xml

BACKGROUND

Growth factors and cytokines are present in small quantities in the oviduct and uterus and some are synthesized by the growing embryo. Granulocytes–macrophage colony-stimulating factor (GM-CSF) is known as an important regulator, which enhances cell proliferation and reduces apoptosis in developing blastocysts, during normal fetal and placental development. The purpose of this study is to investigate whether adding GM-CSF to the culture media affects blastulation or the chromosomal status of mouse embryos.

METHODS

Murine embryos were cultured in vitro from the 2-cell stage until the blastocyst stage in the presence of different concentrations of GM-CSF of 0 ng/ml (control), 1, 2, 5 and 10 ng/ml. The development of each embryo was noted and the embryos were then spread for fluorescence in situ hybridization (FISH) using locus-specific probes (LSI) for chromosomes 2, 11 and 16 in all embryos.

RESULTS

No difference in the blastulation potential was noted with the addition of 1 and 2 ng/ml of GM-CSF compared with the controls, but there was a significant decrease (P < 0.001) in the blastulation rate in the 5 and 10 ng/ml concentrations. The rate of mosaicism/aneuploidy noted in all GM-CSF groups (1, 2, 5 and 10 ng/ml) was slightly higher than in the control group (0 ng/ml GM-CSF) but the differences were not significant. In the mosaic embryos from the GM-CSF cultured groups, the percentage of aneuploid cells was statistically higher than in the control group.

CONCLUSIONS

GM-CSF exerted a negative impact on blastocyst development at higher concentrations. GM-CSF did not affect the rates of mosaicism/aneuploidy, but did increase the percentage of aneuploid cells within the mosaic embryos. Adding GM-CSF to the culture media for clinical use requires further studies either on human or animal models to evaluate its long-term effects.

Source:
http://humrep.oxfordjournals.org/rss/current.xml