Assessment of Physical Activity and Sleep Quality Among Doctors and Medical Students: A Cross-Sectional Study From South India.

Introduction: Sleep quality is critical for medical professionals and students, who often face sleep disturbances due to demanding schedules. This study explores the association between physical activity and sleep quality among doctors and medical students in Tamil Nadu, India, addressing a notable gap in existing research.

Methods: This cross-sectional study was conducted in Tamil Nadu, India, targeting doctors and medical students.

Fine structure of neurally differentiated iPS cells generated from a multiple sclerosis (MS) patient: a case study.

We compared the characteristics of neural cells derived from induced pluripotent stem (iPS) cells from a patient with multiple sclerosis versus neurally differentiated control iPS cells of a healthy individual. The iPS cells were differentiated toward the oligodendrocyte lineage using a four-step protocol established for the differentiation of embryonic stem cells. The resulting cell population was immunostained on day 112 of differentiation for the presence of oligodendrocytes and analyzed by transmission electron microscopy (TEM).

Fine structure of progenitor cells in early ectopic human embryos.

This study has documented the major types of lineage progenitor cells at the second level of cell differentiation after the establishment of the primary germ layers in ectopic human embryos in vivo. These correspond to stages 8 and 9 of embryogenesis (weeks 3-4) in the Carnegie collection. The aim of this study was to provide images of fine structure of tissue progenitor cells to compare them with current imaging of their equivalent stem cells identified using fluorescent stem cell markers.

The fine structure of human germ layers in vivo: clues to the early differentiation of embryonic stem cells in vitro.

The fine structure of the three germ layers in human ectopic embryos (stage 7) have been documented by digital light and electron microscopy. The formation of ectoderm, endoderm and mesoderm and notochordal cells, and also the extraembryonic membranes, amnion and yolk sac, are imaged. The germ layers give rise to all the cells and tissues of the human body.

Structural changes of the zona pellucida during fertilization and embryo development.

The zona pellucida (ZP) is a unique extracellular coat surrounding the maturing oocyte, during ovulation, fertilization, and early embryo development. It is formed by three/four glycoproteins. Ultrastructural data obtained with transmission (TEM) and scanning electron microscopy (SEM) were compared with molecular data on the glycoproteins network from ovulation to blastocyst formation.

Outlook: Derivation of embryonic stem cells for therapy: new technologies.

Embryonic stem cells are currently derived from the inner cell mass of human blastocysts, generated from spare embryos donated for research. To overcome ethical concerns raised by destruction of the embryo, two groups of workers have attempted to derive these cells from isolated blastomeres of 8- to 10-cell stage embryos using the embryo biopsy method akin to that used in preimplantation diagnosis. This paper briefly discusses these two techniques in relation to the routine derivation of stem cells from blastocysts.

Mechanics of human blastocyst hatching in vitro.

Critical examination of 30 blastocysts by transmission electron microscopy at various stages of blastulation and hatching, has revealed the presence of specialized, plump, trophoblastic cells at the points of hatching, which seem to aid in initial breaking of the zona pellucida (ZP) and then widen its opening to permit the progressive emergence of the embryo in amoeboid fashion, when it acquires a characteristic dumb-bell shape. These cells are named 'zona-breaker' cells and their characteristics are described. Normally, trophoblast cells in expanding blastocysts are flattened (squamous), forming a continuous robust epithelium with specialized cell junctions.

Critical evaluation of human blastocysts for assisted reproduction techniques and embryonic stem cell biotechnology.

Critical examination of 30 blastocysts by transmission electron microscopy (TEM) reveals cellular features not usually evident, including abnormalities of cell structure and aberrations such as multinucleation, internal fragmentation, phagocytic or degenerating cells. Invariably, such blastocysts are inactive and delay or fail to expand and hatch in vitro. Hatching seems to be a major problem in ageing blastocysts due to inactivity of the surface epithelium of trophoblast cells that do not stretch and expand.

The fine structure of human embryonic stem cells.

The fine structure of human embryonic stem (ES) cell colonies was analysed by transmission electron microscopy (TEM) after 35 passages of in-vitro culture. Most cells formed compact, saucer-shaped colonies with epithelioid cells on the periphery and polygonal cells within the colony. Three morphological types of cells were identified based on their fine structure: undifferentiated cells resembling inner cell mass (ICM) cells of blastocysts; protein-synthesizing cells at the onset of cellular differentiation; and compact masses of secretory cells resembling unicellular goblet cells of the intestine.

Ultrastructural observations of enzymatically treated human blastocysts: zona-free blastocyst transfer and rescue of blastocysts with hatching difficulties.

Enzymatic treatment of the zona pellucida to either soften or remove totally the zona before blastocyst transfer has resulted in high implantation rates. The zona is usually completely dissolved after 1.5 min exposure with 10 IU pronase at 37 degrees C.

Origin and ploidy of multipronuclear zygotes.

Recently, several authors have proposed strategies for correction of triploidy based on the removal of the extra pronucleus at the zygote stage. In the present bioassay, the following were analysed: (1) the different factors that can induce the formation of multipronuclear zygotes in mammals; (2) the different morphological patterns established according to the number of pronuclei and polar bodies that can be observed at the zygote stage and used to distinguish the origin of multipronuclear zygotes; and (3) the pattern of chromosomal segregation during the first mitotic division and ploidy status of the resulting preimplantation embryos. Such an analysis shows that the morphological criterion of counting the number of pronuclei and polar bodies can be misleading and should not be used for ascertaining the origin of tripronuclear zygotes.

Early cleavage to formation of the unilaminar blastocyst in the marsupial Antechinus stuartii: ultrastructure.

The development of Antechinus stuartii from the 2-cell stage to the blastocyst stage in vivo was examined by routine transmission electron microscopy. The 2-8-cell stages had a similar organization of organelles, whereas the 16- to 32-cell stages had pluriblast cells and trophoblast cells forming an epithelium closely apposed to the zona pellucida. Specialized cell-zona plugs were formed at the 8-cell stage, and primitive cell junctions appeared in later conceptuses.

Ultrastructure of preimplantation human embryos co-cultured with human ampullary cells.

Ova with two pronuclei were co-cultured with established human ampullary cell lines and various stages of preimplantation embryonic development were monitored by Nomarski optics and then assessed by transmission electron microscopy (TEM). Fifteen embryos ranging from the 2-cell stage to blastocyst hatching were examined for normal and abnormal features. Their ultrastructure was similar to that of embryos cultured in Whittingham's T6 medium, reported previously.

Micro-centrifugation of human spermatozoa: its effect on fertilization of hamster oocytes after micro-insemination spermatozoal transfer.

Micro-centrifugation (MC) at 6500 r.p.m.

Improved quality of human embryos when co-cultured with human ampullary cells.

Cultured human, ampullary, epithelial cells obtained from fertile women undergoing hysterectomy were evaluated for the support of human embryonic cleavage and growth in vitro. Twelve patients provided 23 embryos for co-culture with subcultured ampullary cells grown in T6 + 15% patient's serum and 18 embryos for growth in T6 + 15% patient's serum alone (controls). Of embryos co-cultured with ampullary cells, 78% cleaved to the compacted embryo stage and 69% cavitated as compared with 50 and 33% respectively for controls (P less than 0.

Establishment of human ampullary cell cultures.

Epithelial cells from the ampulla of healthy oviducts from 16 women aged 33-41 years and at different phases of their menstrual cycles were used to establish primary cultures and the continuation of a cell line. The morphology and behaviour of these cells in vitro were evaluated using Nomarski's inverted optics, scanning and transmission electron microscopy. Cells from all patients produced confluent monolayers in 6-7 days with no significant relationship of cell growth with stage of cycle.

Transfer of human sperm into the perivitelline space of human oocytes after zona-drilling or zona-puncture.

To evaluate the transfer of sperm from severely oligozoospermic men into the perivitelline space of mature oocytes, zona-drilling with acid phosphate-buffered saline (PBS) and direct zona-puncture in the presence of cytochalasin D were studied. Zona-drilling also was done for eggs from patients with previous failed in vitro fertilization (IVF). Forty-seven eggs from seven patients with oligozoospermia and three patients with failed IVF had a mean of between 2.

Fertilization and development of mouse eggs injected under the zona pellucida with single spermatozoa treated to induce the acrosome reaction.

Mouse spermatozoa were capacitated and acrosome reacted by incubation for 30 min to 6 h in modified Tyrode's medium (T6) and in cGMP. The fertilization rates of eggs microinjected with a spermatozoon from samples incubated for 30 min, 2 h, and 6 h in T6 and in cGMP were 36%, 34%, 29%, and 43%, respectively. These rates were not correlated to the percentage of acrosome-reacted spermatozoa identified after these treatments.

The use of amniotic fluid and serum with propanediol in freezing of murine 2-cell embryos.

Human and mouse embryos have been cultured in amniotic fluid (AF). Human AF and human serum (HS) are used in the freeze-thaw of 2-cell mouse embryos. Two hundred seventy-five 2-cell embryos were collected into phosphate-buffered saline with 20% HS and 20% AF and into 100% HS and AF.

Chromosome anomalies in human oocytes failing to fertilize after insemination in vitro.

Three-hundred-and-two unfertilized oocytes left over from successful in-vitro fertilization (IVF) attempts in 143 women (27-42 years) on a follicular stimulating hormone-human menopausal gonadotrophin (FSH-HMG) stimulation regime were subjected to chromosome analysis. Ten oocytes were degenerated with no visible chromosomes and 41 metaphases had chromosomes that were clumped together which could not be interpreted either numerically or structurally. Of the remaining oocytes, 76.