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Biomedical subjects

S A Thompson

Publications and source records attributed to S A Thompson.

At least 163 records · Page 9Linked to original sources
PubMed1979

Fine structural studies of rat seminal vesicle in castrated and intact animals following estrogen treatment.

The effect of estradiol and/or testosterone upon secretion by seminal vesicle in castrated and intact rats was assessed in young adult Sprague-Dawley rats, using light microscopy (LM), transmission (TEM) and scanning (SEM)electron microscopy. Hormones were injected daily for ten days beginning ten days after castrations were performed. The normal rat seminal vesicle, as revealed by SEM, was characterized by a large saccular lumen with highly folded walls. Cell surfaces were covered with microvilli, or occasionally displayed a protruding, ruffled surface, sparsely covered with short microvilli. Cytology was normal in testosterone-treated animals. Estradiol treatment of castrated animals stimulated secretion by seminal vesicle epithelial cells as evidenced by the presence of normal secretory bodies, the presence of RER, and moderately hypertrophied Golgi complexes. These glands were not heavier than were glands from castrated, untreated animals, although the epithelial cells were significantly taller. Secretion was maintained in intact animals treated with estradiol, although glands were smaller and epithelial height was reduced. Estradiol and testosterone treatment in combination did not appear to have an additive effect on secretion, weight of the gland, or epithelial height. The following results support the hypothesis that estrogen-induced prolactin synthesis and release may be involved in the mechanism by which estradiol effected stimulation of seminal vesicle epithelium. Prolactin-treated, castrated animals exhibited focal areas of stimulated epithelium. In hypophysectomized animals (untreated controls), the seminal vesicle epithelium retained some secretory bodies and secretory fluid in the glandular lumen; epithelial height was taller than that in castrated controls. Estrogen treatment reduced the epithelial height to that of castrated controls; there was no evidence of secretion. This suggests that in the absence of anterior pituitary hormones, including prolactin, the stimulatory effect of estradiol on seminal vesicle epithelium was nullified. In adrenalectomized/castrated animals, estradiol treatment stimulated secretion in seminal vesicle epithelium just as in non-adrenalectomized/castrated animals. This indicates that the adrenal gland plays a non-essential role in the action of estrogen on seminal vesicle epithelium.

Adrenal Cortex Hormones↗
PubMed1979

Effects of estrogen upon the fine structure of epithelium and stroma in the rat ventral prostate gland.

We studied the effects of estradiol upon the fine structure of the rat ventral prostate, with special emphasis on the interstitial tissue. Intact and castrated rats were injected with estradiol or testosterone in combination, or with peanut oil (control). Estrogen exerted an antiandrogenic effect on the epithelium of intact animals resulting in lower epithelial height and reduction in the number of cell organelles and secretory bodies; however, the prostate gland did not atrophy to the same degree as that in castrated controls. In castrates, estradiol had no discernible effect upon the glandular epithelium. Although testosterone alone was able to restore glandular morphology to normal in these animals, estrogen in combination prevented regeneration of rough endoplasmic reticulum and elicited the formation of large lipid-like inclusions and the accumulation of secretory bodies in the apical zone of many cells. Intact animals treated with these hormones in combination exhibited many of the same effects except that a more normal configuration of rough endoplasmic reticulum was present. In castrates, the prostatic stroma became thickened, with a large increase in fibrous material between and surrounding each acinus, although smooth muscle cells retained their normal cytology. With estradiol treatment, singly or in combination with testosterone, smooth muscle cells increased in size and number and organelles decreased in number, cytoplasm became more electron dense, and nuclei became more heterochromatic. Surface vesicles were profuse in smooth muscle cells in animals treated with estradiol alone; larger phagocytic-like vacuoles were characteristic of the glands of animals treated with estrogen and testosterone in combination. In these latter treatment groups, testosterone prevented the overall hypertrophy and hyperplasia of the interstitial tissue; to a degree, endogenous testosterone levels in intact animals treated with estradiol alone prevented these effects as well.

Animals↗
PubMed1978

Amniotic fluid phosphatidylglycerol in diabetic pregnancies.

Despite L/S ratios indicating fetal lung maturity, respiratory distress continues to occur more frequently in infants of diabetic mothers. Amniotic fluid pulmonary phospholipids were studied in an attempt to understand the occurrence of false-positive L/S ratios in preterm diabetic pregnancies. Qualitative chromatography assays of surfactant phosphatides revealed reduced or absent phosphatidylglycerol in diabetic amniotic fluid specimens between 34 and 37 weeks' gestation. Mean phosphatidylglycerol in 15 nondiabetic and 29 diabetic specimens was 16 and 4 per cent of total extracted pulmonary phospholipids (P less than 0.001). Non-insulin-dependent diabetic pregnancies had lowest mean per cent phosphatidylglycerol. Respiratory distress occurred in six infants of diabetic mothers delivered preterm with L/S ratios of 2:1 or greater; phosphatidylglycerol was absent in five. The inclusion of phosphatidylglycerol in amniotic fluid phospholipid assessment may be an adjunctive index for fetal lung maturation in diabetic pregnancies.

Amniotic Fluid↗
PubMed1978

Synergistic effects of prolactin and testosterone in the restoration of rat prostatic epithelium following castration.

Prolactin is known to enhance the uptake and metabolism of testosterone in male accessory sex organs and to increase the weight of accessory sex organs from castrated rats over those from controls treated with testosterone alone. The present study was directed toward defining fine structural changes detectable with scanning and transmission electron microscopy which might accompany such responses. Accordingly, rat ventral prostate gland was examined from castrated animals which had received testosterone propionate and ovine prolactin singly or together, or which had received vehicle only. Unoperated animals served as additional controls. Post-castration glandular atrophy was not influenced by prolactin treatment alone. Testosterone restored epithelial height, secretory product, Golgi complexes and rough endoplasmic reticulum, such that cellular and tissue morphology was generally indistinguishable from that of unoperated controls. Prostatic tissue from animals given testosterone and prolactin simultaneously exhibited pleomorphic, cytoplasmic apical projections which extended into the acinar lumen. Transmission electron microscopy demonstrated that these blebs were devoid of organelles and microvilli; scanning electron microscopy revealed that the blebs were highly wrinkled and more numerous than were the projections observed in tissue from animals treated with testosterone alone, or in tissue from unoperated controls. It is suggested that such blebbing may reflect enhanced apocrine secretion in prolactin/testosterone stimulated restoration of the prostate gland in castrated rats.

Animals↗
PubMed1977

A neurohistochemical and histological study of peripheral autonomic neurons of the human bladder neck and prostate.

The histological structure and neurohistochemical properties of peripheral autonomic nerve cells which supply the bladder neck and male genital tract have been examined in the human infant. Two types of neuron have been recognised and their morphological features described. One type was rich in acetylcholinesterase but devoid of catecholamine and occurred in relation to the bladder neck and preprostatic urethra. These cells probalby represent presumptive cholinergic parasympathetic neurons which innervate the urinary bladder. The second type contained noradrenaline and supplied nerve fibres to the musculature of the musculature of the gential tract. These ganglion cells correspond to the 'short' adrenergic neurons which have been described in other species.

Acetylcholinesterase↗
PubMed1976

The embryological development and cytodifferentiation of the pars distalis of the golden hamster (Mesocricetus auratus). A light and electron microscopic study.

The embryological development of cytodifferentiation of the hamster pars distalis was investigated using light and electron microscope techniques in order to obtain basic information for comparison with pituitary development in other mammalian species. The normal chronological events in the development of the hamster pars distalis closely paralleled the pituitary organogenesis of other laboratory rodents. Rathke's pouch formed and touched the infundibulum at 8 1/2 days of gestation and separated from the stomodeum 3 days later. Penetration of vascular elements from the developing hypophysial portal system into the pars distalis occurred at 12 1/2 days gestation. This was also the first day that small secretory granules were seen in any of the parenchymal cells. Further cytodifferentiation during the following prenatal, and first few postnatal days of life revealed granulated cells which, in most cases, could not be identified using morphological criteria or granule size as may be done in the adult. An orderly sequence of inductive and morphological events appears to take place in the developing hamster adenohypophysis paralleling similar events observed in other animals.

Animals↗
PubMed1976

The distribution of concanavalin A binding sites on the intestinal epithelium of the nematodes Ascaris suum and Parascaris equorum.

Receptors for Concanavalin A (Con A), were localized on the intestinal epithelium of the nematodes Ascaris suum and Parascaris equorum. Fixed tissue incubated in 3H-Con A showed labeling of the microvilli surface and basal membrane. Using Con A coupled with peroxidase, the tips of the microvilli of Ascaris suum and the tips and lateral surfaces of Parascaris equorum were stained. The basal membrane of both species was also labeld. No labeling was observed on control tissue incubated without Con A or on tissue incubated with Con A to which alpha-methyl-D-mannoside was added.

Animals↗
PubMed1976

Histochemical light microscopic study of catecholamine containing paraganglia in the human pelvis.

Histological and histochemical techniques have been employed to determine the structure and autonomic innervation of paraganglia located in the human pelvis. In foetal and early postnatal tissues, paraganglia formed rounded cellular masses which were frequently in company with the autonomic nerves and ganglia of the urinary bladder and other pelvic viscera. The constituent cells contained only small amounts of cholinesterase and were unrelated to enzyme positive autonomic nerves; acetylcholinesterase containing nerves were occasionally observed in the capsule and the fibrous septa of the pelvic paraganglia. In early postnatal specimens, pelvic paraganglia frequently contained single or multiple "pacinian-like" corpuscles, each possessing a central region which was rich in both acetyl and pseudocholinesterase. These structures were rarely observed within autonomic ganglia and were absent 4 1/2 years post partum. By means of a histochemical technique, pelvic paraganglia were found to contain catecholamine which was attributed to the presence of relatively large quantities of noradrenaline. These observations have been discussed with particular reference to the results of other studies on the autonomic innervation of paraganglia.

Child, Preschool↗
PubMed1976

Immunohistochemical localization of prolactin cells of the pars distalis in the fetal and neonatal hamster: a light and electron microscopy study.

Using the immunoperoxidase technique, a small number of prolactin cells were first detected in the pars distalis of the hamster near developing sinusoids at 13 1/2 days gestation. Little change in number or distribution of immunoreactive cells was noted until the first few days after birth when a dramatic increase in number of immunoreactive cells was demonstrated throughout the pars distalis. Electron microscopy revealed cells in the fetal and neonatal anterior pituitary which had immunoreactive granules smaller in diameter than those seen in adult pituitary cells.

Animals↗
PubMed1975

Carbohydrate cytochemistry of the intestinal epithelium of Ascaris suum. Nature of the microvilli glycocalyx and basal lamella.

Results of various cytochemical tests demonstrate large deposits of glycogen within the intestinal absorptive cells of Ascaris suum. Carbohydrate material is also associated with the microvilli surface and basal lamella. Staining produced by the periodate-thiocarbohydrazide-osmium procedure was abolished by analine or m-aminophenol. Diastase digestion did not alter the staining on the microvilli surface. Similar results were seen using the silver methenamine procedure. A positive reaction was noted on the microvilli surface, vesicles in both the apical and basal cytoplasm, Golgi apparatus, and basal lamella. Lanthanum nitrate stained the microvilli surface and intercellular spaces between absorptive cells. Alcian blue or cetylpyridinium chloride in combination with lanthanum enhanced the staining produced by lanthanum alone. These results suggest the presence of acidic glycans on both the microvilli surface and basal lamella.

Animals↗
PubMed1975

Amniotic fluid phospholipid analysis in normal and complicated pregnancies.

Amniotic fluid lecithin/sphingomyelin (L/S) ratios were determined at least once in 190 pregnancies. In 127 pregnancies an amniotic fluid specimen was obtained within 72 hours of delivery. This constitutes the corrected group. Respiratory distress was encountered 21 times with 13 of these being clinical hyaline membrane disease (CHMD). The remaining cases were either transient respiratory distress or felt to be aspiration pneumonia. When the L/S ratio was positive and the infant delivered vaginally, there was only one case of CHMD. However, when the patients had grave enough disease to warrant cesarean section, CHMD was encountered in seven cases out of 68 cesarean sections. Of the eight cases of CHMD, five were in mothers whose pregnancy was complicated by diabetes mellitus.

Amniocentesis↗
PubMed1975

Serum prolactin levels in fetal and neonatal hamsters and the relationship to maternal levels.

Immunoreactive prolactin was measured by RIA in 13.5-15.5 day gestation fetal and 0.5-3.5 day neonatal hamster serum and found to significantly reflect rises and falls in maternal levels. On the average, fetal and neonatal levels were 37% of maternal prolactin serum levels. 125I-PRL injected into 13.5-15.5 day pregnant hamsters was demonstrated to cross the placenta and enter fetal circulation. Ten min after injection, fetal serum levels were calculated to be an average of 3.9% of the radioactivity recorded in maternal serum. There is a strong possibility that fetal prolactin serum levels may be, at least in part, attributed to a maternal source.

Animals↗