Vegetative cells of Azotobacter vinelandii contain a system of intracytoplasmic membranes in the form of numerous internal vesicles. The three-dimensional morphology of these internal vesicles was established by an examination of stereopair electron micrographs of negatively stained cells. The vesicles assumed a variety of forms ranging from nearly spherical units to short, curved tubules. Thes...

A nonspecific density labeling technique has been employed to monitor the synthesis of intracytoplasmic membrane in synchronously dividing populations of Rhodopseudomonas sphaeroides. The intracytoplasmic membranes of cells synchronized in D2O-based medium were found to undergo discontinuous decreases in specific density during synchronous cell growth following transfer to H2O-based medium. The...

Intracytoplasmic Sperm Injection (ICSI) is an assisted reproductive technique [4] (ART) initially developed by Dr. Gianpiero D. Palermo [5] in 1993 to treat male infertility [6]. It is most commonly used in conjunction with in vitro [7] fertilization [8] (IVF) or a less commonly used technique called zygote intrafallopian transfer [9] (ZIFT). In natural fertilization [8], the sperm [10] must pe...

background: testis tissue xenografting and the resultant sperm in a xenograft may provide a unique approach to rescue the genetic material of males that die prematurely and is a model for the study of human spermatogenesis and can represent an alternative approach for fertility preservation in cancer patients. this study was aimed to evaluate the xenogenic dog sperm in formation of male pronucl...

background: pregnancy is a successful transplantation. the factors evading rejection of the fetus are poorly understood. recently an interest has grown, in hla-g molecules as one of these factors. since these antigens are mainly expressed on the surface of cytotro-phoblasts that are in direct contact with maternal tissues, it has been suggested that these molecules may have a role in induction ...

The objective of this study was to compare (i) the intracytoplasmic sperm injection outcomes among groups with different total motile sperm count ranges, (ii) the intracytoplasmic sperm injection outcomes between groups with normal and abnormal total motile sperm count, and (iii) the predictive values of WHO 2010 cut-off values and pre-wash total motile sperm count for the intracytoplasmic sper...

abstract background: the intracytoplasmic sperm injection procedure ending with total fertilization failure is very distressfull event for both the clinician and the patient. objective: the aim of this study was to identify independent factors which could be used to identify total fertilization failure before the day of intracytoplasmic sperm injection. materials and methods: this was a retrosp...