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Biomedical subjects

B Leblanc

Publications and source records attributed to B Leblanc.

30 records · Page 2Linked to original sources

Immunocytochemistry of thyroid C-cell complexes in dogs.

Ten thyroid C-cell complexes from five male and five female Beagle dogs, 1 to 2 years old, were studied using single and double immunocytochemical staining with the peroxidase-antiperoxidase technique. The antigens tested included thyroglobulin, calcitonin, calcitonin gene-related peptide, somatostatin, neuron specific enolase, and neurotensin. All C-cell complexes contained four cell types in various proportions: 1) follicular cells staining for thyroglobulin; 2) C-cells staining for calcitonin, calcitonin gene-related peptide, and neuron specific enolase; 3) stellate cells and cuboidal cells in follicle-like structures staining positively for somatostatin; and 4) undifferentiated cells staining negatively for all antigens. No positive immunoreactivity for neurotensin was detected. These findings support the hypothesis that thyroid C-cell complexes are ultimobranchial remnants that can give rise to thyroid follicles and C-cells.

Animals↗

Pancreatic endocrine responses to nutrients and bombesin after segmental pancreas autotransplantation in dogs.

The capacity of autotransplanted (ATP) distal pancreas segments with systemic venous and peritoneal exocrine drainage to support physiologic control of plasma glucose levels was tested, and compared with the functions of "simulated autotransplants" (SATP) prepared with similar dissection and peritoneal exocrine drainage, but with hepatic portal venous drainage, in dogs. In ATP in the postabsorptive state, plasma levels of glucose, immunoreactive insulin (IRI) and immunoreactive glucagon (IRG1) were normal. Autotransplants resulted in impaired glucose tolerance after meals with impaired early insulin responses, and the normal brisk rise of IRG1 in the plasma was delayed and reduced through the first 30 min of feeding. In ATP, also, the response to bombesin was abnormal; the normal stimulation of release of both IRI and IRG1 was delayed in both cases. In studies of responses to oral and intravenous glucose in ATP and SATP dogs, similar mild degrees of glucose intolerance were found with both routes of administration; however, whereas in ATP dogs increases of IRI were highly exaggerated with both routes of administration of glucose, in SATP dogs plasma IRI rose from subnormal levels in the postabsorptive state through subnormal increments with both routes of administration. Further studies are necessary to determine the relative importance of denervation and reduction of the mass of the pancreas in these effects, and to assess the significance of the differences in blood insulin levels in the two preparations.

Administration, Oral↗

Histology and histomorphometry of the tibia growth in two turkey strains.

Qualitative and quantitative histological methods on decalcified and undecalcified specimens were used for comparing the linear and radial growth of the tibia in two turkey strains: a light strain, Betina, without leg problems and a heavy strain, Maxiboul, with leg problems. Groups of 10 clinically healthy male turkeys of each strain were studied at 2, 6, 8, 16, and 20 weeks of age. Three histomorphometric parameters of longitudinal growth were quantitated in the proximal growth plate and metaphysis. These were: height of the proliferative zone, density of ossification buds (metaphyseal sprouts), and volume of metaphyseal trabecular bone. Four histomorphometric parameters of radial growth were quantitated in the diaphysis. These were cortical thickness, active zone/total surface, density of maturing osteons in the active zone, and bone apposition rate at the maturing primary osteons level. The results showed some evidence for factors predisposing to leg problems in the Maxiboul strain. At 8 weeks, the Maxiboul strain had a lower ossification bud density (13.1/mm2 vs. 20.7/mm2; P less than .05) and a lower metaphyseal trabecular bone volume (16.4% vs. 22.0%; P less than .05) when compared to the Betina strain. No difference was detected in the cortical thickness of the diaphysis in the two strains except at 2 weeks of age (799 microns vs. 387 microns; P less than .001), despite the heavier weight of the Maxiboul strain.

Animals↗

Eosinophilic fasciitis. Ultrastructural study of an early biopsied case.

A 55-year-old women with eosinophilic fasciitis was biopsied 8 weeks after the onset of her illness. Under the electron microscope the changes were almost exclusively located in the fascia with many active fibroblasts, accumulation of protocollagen fibrils (10-50 A diameter), elastic fibre remodelling and numerous degranulating mast cells. The inflammatory infiltrate was dense and mostly composed of lymphocytes and plasma cells, with 16% eosinophils. The connective tissue changes may be part of a healing process following microinjury of the fascia. However, large numbers of lymphocytes and plasma cells are unusual in the healing process and are more common in the cellular reaction of morphea. Nevertheless, the absence of macrophages in subcutaneous fat, together with large number of eosinophils in the fascia may be considered to be distinctive features of eosinophilic fasciitis.

Biopsy↗

[Sciatica caused by disk herniation in children. Apropos of 4 cases].

The authors report 4 cases of sciatica from disk herniation occurring in children under 16. It happens rarely in this age range, as is shown in the review of the literature performed for this article. The symptomatology is similar to that in adults. The physical signs are much more prominent than the functional signs. An original traumatism, sometimes severe, is often encountered. The standard X-ray examination is of little use in diagnosis, while contrast studies (opaque myelography, phlebography) clearly show the lesions of compression. Surgical treatment is frequent but not compulsory, following the same rules than in the adults. The post-operative results are usually excellent.

Adolescent↗

[Ureteroscopy versus in situ extracorporeal shockwave lithotripsy in the treatment of calculi of the distal ureter].

In a retrospective study from a unique center (St. Luc Hospital, Montreal) stone clearance of 88 consecutive distal ureteral calculi (below pelvic brim) treated by extracorporeal shock wave lithotripsy in situ were compared to a group of 94 distal ureteral calculi treated by ureteroscopy during the same period. Our results show 84% success rate for ureteroscopy which is clearly superior than 58% stone clearance rate at 3 month follow-up for ESWL Success rate was influenced by stone size in the ESWL group but not in the ureteroscopy group. This study reveals similar success rate for calculi smaller than 6 mm but for larger calculi, success rate of ureteroscopy is significantly superior.

Adolescent↗