### A. Overview

Extracellular purines (adenosine, ADP, and ATP) and pyrimidines (UDP and UTP) are important signaling molecules that mediate diverse biological effects via cell-surface receptors termed purine receptors. In this review particular emphasis is placed on the discrepancy between the

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Receptors for Purines and Pyrimidines

BACKGROUND Semen quality is taken as a surrogate measure of male fecundity in clinical andrology, male fertility, reproductive toxicology, epidemiology and pregnancy risk assessments. Reference intervals for values of semen parameters from a fertile population could provide data from which prognosis of fertility or diagnosis of infertility can be extrapolated. METHODS Semen samples from over 4500 men in 14 countries on four continents were obtained from retrospective and prospective analyses on fertile men, men of unknown fertility status and men selected as normozoospermic. Men whose partners had a time-to-pregnancy (TTP) of < or =12 months were chosen as individuals to provide reference distributions for semen parameters. Distributions were also generated for a population assumed to represent the general population. RESULTS The following one-sided lower reference limits, the fifth centiles (with 95th percent confidence intervals), were generated from men whose partners had TTP < or = 12 months: semen volume, 1.5 ml (1.4-1.7); total sperm number, 39 million per ejaculate (33-46); sperm concentration, 15 million per ml (12-16); vitality, 58% live (55-63); progressive motility, 32% (31-34); total (progressive + non-progressive) motility, 40% (38-42); morphologically normal forms, 4.0% (3.0-4.0). Semen quality of the reference population was superior to that of the men from the general population and normozoospermic men. CONCLUSIONS The data represent sound reference distributions of semen characteristics of fertile men in a number of countries. They provide an appropriate tool in conjunction with clinical data to evaluate a patient's semen quality and prospects for fertility.

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World Health Organization reference values for human semen characteristics

WHO laboratory manual for the examination and processing of human semen

In this innovative book, a well-known feminist and sociologist-who is also the founding editor of Gender & Society-challenges our most basic assumptions about gender. Judith Lorber argues that gender is wholly a product of socialization, subject to human agency, organization, and interpretation, and that it is a social institution comparable to the economy, the family, and religion in its significance and consequences. Calling into question the inevitability and necessity of gender, she envisions a society structured for equality, where no gender, racial ethnic, or social class group is allowed to monopolize positions of power.

Paradoxes of gender

http://directory.umm.ac.id/Data%20Elmu/jurnal/A/Animal%20Reproduction%20Science/Vol60-61.Issue1-4.Jul2000/1971.pdf

The causes of reduced fertility with cryopreserved semen

Approaching the next millennium: How should we manage andrology diagnosis in the intracytoplasmic sperm injection era?

The value of in vitro fertilization for the treatment of unexplained infertility.

Acrosin, a neutral proteinase, is located within the acrosome. The aim of this study was to evaluate acrosin concentrations in patients with severe damage of the sperm head and to determine whether acrosin concentration could predict the chances of fertilization in an IVF program. Sixty patients were accepted into this study, prospectively. The patients were divided into two groups, those with a normal morphology of 20 million sperm/ml and >30% progressively motile sperm. The acrosin assays were performed on the semen sample obtained on the day of IVF. Routine IVF insemination procedures were used, and only mature oocytes were considered. The only factor that showed a significant correlation with fertilization was normal morphology (p< 0.01). The mean acrosin level was 73.4 ± 38.6 mIU/10 million sperm in group I and 70.9 ± 42.7 mIU/10 million sperm in group II (no significant d...

Correlation Between Sperm Morphology, Acrosin, and Fertilization in an IVF Program

Semen treatment with progesterone and/or acetyl-L-carnitine does not improve sperm motility or membrane damage after cryopreservation-thawing.

The recognition of carbohydrate epitopes by complimentary protein receptors has been shown to be a critical factor in gamete interaction in many different animal species. In this study it was hypothesized that, in the human, gamete binding requires an interaction between selectin ligands on the zona pellucida and putative egg binding proteins on the sperm surface. The hemizona assay (a unique internally controlled bioassay that evaluates tight binding of sperm to the zona) and advanced methods of carbohydrate analysis were used to test this hypothesis. From these tests it was shown that oligosaccharide recognition is also required for initial human gamete binding. This study suggests the existence of distinct egg binding proteins on human sperm that can bind to selectin ligands. Additionally, the results suggest a possible convergence in the types of carbohydrate sequences recognized during initial human gamete binding and immune/inflammatory cell interactions. Glycoconjugates that manifest selectin-ligand activity and that express specific carbohydrate epitopes have potent contraceptive and immunosuppressive effects. Such specific oligosaccharide sequences may provide an appropriate recognition signal for embryo development and protection.

Sergio Oehninger

Papers

Approaching the next millennium: How should we manage andrology diagnosis in the intracytoplasmic sperm injection era?

The value of in vitro fertilization for the treatment of unexplained infertility.

Correlation Between Sperm Morphology, Acrosin, and Fertilization in an IVF Program

Semen treatment with progesterone and/or acetyl-L-carnitine does not improve sperm motility or membrane damage after cryopreservation-thawing.

Involvement of selectin-like carbohydrate binding specificity in human gamete interaction