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Biomedical subjects

W Burch

Publications and source records attributed to W Burch.

11 recordsLinked to original sources
PubMed1989

Insulin-like growth factor I mediates selective anabolic effects of parathyroid hormone in bone cultures.

PTH was studied for its effects on bone formation in cultured rat calvariae. 0.01-10 nM PTH stimulated [3H]thymidine incorporation into DNA by up to 4.8-fold. Although continuous treatment with PTH for 24-72 h inhibited [3H]proline incorporation into collagen, transient (24 h) treatment enhanced [3H]proline incorporation into collagen 24-48 h after the hormone was removed. The collagen stimulated by PTH was type I and the effect was observed in the periosteum-free bone and was not blocked by hydroxyurea. Furthermore, treatment with 1-100 nM PTH for 24 h increased insulin-like growth factor (IGF) I concentrations by two to fourfold, and an IGF I antibody prevented the PTH stimulation of collagen synthesis, but not its mitogenic effect. In conclusion, continuous treatment with PTH inhibits calvarial collagen, whereas transient treatment stimulates collagen synthesis, and the stimulatory effect is mediated by local production of IGF I.

Animals↗
PubMed1987

Gastric emptying, glucose tolerance, and insulin response after duodenojejunostomy.

We investigated the impact of direct jejunal delivery of various meals on gastric emptying, glucose tolerance, and insulin response in a chronic dog model following duodenojejunostomy. Ten beagle dogs underwent duodenal transection 2 cm distal to the pylorus and end-to-side duodenojejunostomy 20 cm distal to the ligament of Treitz. Three months after operation each dog underwent gastric emptying studies using radiolabeled normal saline, 20% glucose solution, and standardized mixed solid meal. Glucose tolerance tests with plasma insulin determinations were obtained using the glucose meal. After duodenojejunostomy both the rapid exponential pattern of emptying of normal saline and the slower linear pattern of glucose emptying seen in intact dogs were preserved. The linear gastric emptying of the solid meal which was slower than gastric emptying of either of the liquid meals was also preserved. Although integrated plasma glucose levels over 2 hr were 484.8 +/- 40.4 and 456.6 +/- 30.4 mg X hr/dl in intact and duodenojejunostomy dogs, respectively (P greater than 0.05), the initial rate of rise of plasma glucose was significantly delayed in the duodenojejunostomy dogs. But integrated plasma insulin levels over 2 hr differed significantly (P less than 0.05) between the intact (71.6 +/- 9.2 microU X hr/nl) and duodenojejunostomy (48.3 +/- 6.2 microU X hr/nl) dogs. We conclude that duodenojejunostomy (jejunal delivery) preserved the patterns of gastric emptying of saline, glucose, and mixed solid meals; retarded initial plasma glucose response to the glucose meal; and blunted plasma insulin response to the glucose load.

Animals↗
PubMed1976

Mechanism of thyroid allograft rejection.

Balb/c thyroids, held in organ culture for 26 days, survive and function as well as isografts for greater than 100 days in CBA recipients. Uncultured allografts are totally rejected by 20 days after transplantation. Prolonged allograft survival can also be achieved by the treatment of donor animals with cyclophosphamide prior to harvesting tissues for transplantation. These allografts do not survive as well as 26 day cultured allografts, but cyclophosphamide pretreatment reduces the culture time required to achieve indefinite survival to 7 days. The provision of an allogeneic (LD) stimulus by thyroid tissue that is I-region incompatible with the host does not facilitate the rejection of a tolerated cultured allograft. However, activation of the host immune system by an uncultured graft syngeneic to a tolerated cultured allograft leads to the chronic rejection of the cultured transplant. The transfer of a tolerated cultured allograft back to its strain of origin induces an acute inflammatory reaction that causes tissue damage within the transplant but does not lead to the total destruction of the tissue.

Animals↗
PubMed1973

Successful treatment of Pseudomonas cepacia endocarditis with trimethoprim-sulfamethoxazole.

A patient with a history of alcoholism and drug abuse who developed Pseudomonas cepacia endocarditis is described. The organism was found to be resistant in vitro to all common antimicrobial agents except chloramphenicol and trimethoprim-sulfamethoxazole. Treatment failed with penicillin and streptomycin and later with chloramphenicol. Orally administered trimethoprim-sulfamethoxazole, however, resulted in sterilization of the patient's blood and aortic valve which was resected 27 days after the start of therapy. A 6-week course of therapy was completed and, to date (6 months after treatment), there has been no recurrence.

Administration, Oral↗
PubMedDate not supplied

Malignant teratoma of the thyroid in an adult: CT appearance.

A case of malignant teratoma of the thyroid gland is presented. Computed tomography identified an inhomogeneous mass with dense calcifications involving the thyroid gland and compressing the upper airway. Enlarged, peripherally enhancing lymph nodes in the neck and mediastinum suggested its malignant etiology.

Adult↗