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Biomedical subjects

D L Wilbur

Publications and source records attributed to D L Wilbur.

At least 19 recordsLinked to original sources

Probable pulmonary anisakiasis accompanying pleural effusion.

The first probable human case of pulmonary anisakiasis is reported. A 37-year-old Japanese person in California developed pleural effusion after consumption of raw salmon at a seafood restaurant in San Francisco. A marked eosinophilia was noted in the blood and pleural exudate. The patient was tested for helminthic infections by intradermal, complement fixation, Ouchterlony, and immunoelectrophoresis tests using antigens of various worm species. A specific precipitin band was recognized only with Anisakis (Type I larvae) antigen.

Adult

An in vitro model for studies of intercellular communication in cultured rat anterior pituitary cells.

The formation of intimate associations among different hormone-secreting cells within the rat adenohypophysis may serve as a possible site for physiologic regulation. In this report we describe a high density plating method which enables us to study cell-to-cell interactions within anterior pituitary cell cultures. Trypsin-dispersed pituitary cell suspensions attach rapidly (within 6 hr) and quantitatively (95-97%) to glass or plastic surfaces when plated in medium containing microM calcium concentrations (pH 7.6-7.8). Freshly plated cell suspensions obtained from female pituitary glands contained subpopulations of mammotrophs 49.3%, somatotrophs 30.3%, gonadotrophs 12.6%, corticotrophs 3.4% and thyrotrophs 1.5%. Epithelial cell colonies were formed during a 3-day culture period as the cells flattened and re-established contacts with neighboring cells. Freeze-fracture electron microscopic analysis of these colonies produced morphological evidence for direct intercellular contacts among the hormone-secreting cells. Large areas of tight junctions and small gap junctions were identified on the membranes of the epithelial cells within these colonies. Cells which contained tight junctions usually contained microvilli and morphological signs of active hormone secretion. Small junctional plaques containing tightly packed intramembrane particles were also occasionally found on the membranes of cells which were actively secreting pituitary hormones. The high density plating procedure which is described in this report provides greater opportunity for cell-cell interaction and thus may prove to be a useful model for evaluating the role of intercellular communication within this tissue.

Animals

Hypophysial portal vascular infusion of TRH in the rat: an ultrasturctural and radioimmunoassay study.

The hypophysial portal vessels and anterior pituitary gland of adult male Wistar rats were exposed surgically. A hypophysial portal vessel was cannulated and infused for one minute with saline or thyrotrophin (TRH). Anterior pituitary glands were collected at 1,5,15,30 or 60 minutes after cessation of infusion, for light and electron microscopic examination. Before and immediately after cannulation of a portal vessel, a 1-ml sample of blood was collected at 1,5,15,30, or 60 minutes, from the femoral vein for radioimmunoassay (RIA) of growth hormone. Thyrotrophs from anterior pituitary glands of rats infused with TRH displayed emiocytic activity at all time-periods studied. Rough endoplasmic reticular (RER) cisternae were dilated at 15 minutes following infusion and remained dilated at 30 and 60 minutes. TRH was observed to stimulate emiocytic activity in most pituitary cell-types. Extensive dilations of RER cisternae were also observed in mammotrophs and gonadotrophs, but were not observed in somatotrophs or adrenocorticotrophs. The demonstration that thyrotrophs, mammotrophs, somatotrophs, and gonadotrophs respond to TRH suggests that some common features may be shared by these cells. Preliminary analysis of the RIA data show that TRH was potent in elevating radioimmunoassayable growth hormone levels. Significant increases (p less than 0.02) in plasma GH levels were present at the earlier time periods studied (1,5, and 15 minutes) following the infusion of TRH, but no at 30 or 60 minutes. These findings provide additional support for the non-specific action of TRH upon hte various adenohypophysial cell types, and demonstrate that TRH stimulates these cells by a direct action on the adenohypophysis.

Animals

An ultrastructural and radioimmunoassay study of anterior pituitary somatotrophs following pituitary portal vessel infusion of growth hormone releasing factor.

The hypophysial portal vessels and anterior pituitary glands of adult male rats were surgically exposed, cannulated and infused for 1 min with saline, growth hormone-releasing factor (GH-RF), and dbcAMP. After cessation of infusion, anterior pituitary glands were collected at 1, 5, 15, 30 or 60 min for electron microscopic and ultrastructural cytochemical examination. Before and after cannulation of a portal vessel a 1-ml sample of blood was collected at 1, 5, 15, 30 or 60 min from the femoral vein for RIA of growth hormone. When viewed ultrastructurally, the initial response following the infusion of GH-RF into a portal vessel was one of granule release. Emiocytic activity was observed at all time intervals studied. This response was followed 30 min later by evidence of increased protein synthesis. Significant increases in plasma GH levels were present at 1, 5, and 15 min following infusion of GH-RF but not at 30 or 60 min. Preliminary analysis of the RIA data suggests that dbcAMP was significantly more potent than GH-RF in elevating radioimmunoassayable plasma GH levels. The results suggest that similar mechanisms of synthesis and release were involved.

Animals