Calcium homeostasis after parathyroidectomy in normal and shocked states

The natural history of parathyroidectomy was studied for 75 weeks in two dogs. After parathyroidectomy, the dogs required intravenous and intramuscular calcium supplementation for 1 week. Despite calcium supplementation, in 2 weeks the ionized calcium (Ca++) level fell from 4.67 mg/dl to 2.39 mg/dl. The Ca++ level rose to 4.25 mg/dl by 7 weeks after which the intramuscular calcium supplement was gradually weaned so that no calcium was given after 20 weeks. The Ca++ level stabilized at 3.15 to 3.25 mg/dl after 20 weeks. Postoperative parathormone (PTH) levels remained low. The response to hemorrhagic shock in these two calcium-independent dogs was compared with that seen in two calcium-dependent dogs 4 weeks after parathyroidectomy and to that seen in two euparathyroid dogs. Shock caused a sharp decrease in Ca++ in all animals that had parathyroid ectomy. Prostaglandin E2 (PGE2) was elevated preoperatively in these dogs and fell markedly during shock. Ca++ remained normal and PGE2 increased slightly after shock in the euparathyroid dogs. Cardiac output rose with resuscitation in the euparathyroid dogs but remained constant in the calcium-dependent dogs and increased slightly in the calcium independent parathyroidectomized animals. PTH levels were low in the parathyroidectomy groups and did not react to shock. PTH increased markedly after resuscitation in the euparathyroid dogs, suggesting its role as an acute-phase hormone. All levels returned to baseline levels within 3 days after shock. Adaptation to hypocalcemia occurs in parathyroidectomized dogs and involves PGE2 as well as other factors. Hemorrhagic shock exceeds this compensatory response which in euparathyroid dogs involves active PTH release in response to hypocalcemia.     

The effects of chemotherapy on murine wound healing and orocutaneous fistula closure

The effects of cisplatin and 5-fluorouracil on wound breaking strength and the rate of closure of an orocutaneous fistula were studied in 80 male rodents. Treatment rats received a total of 4.6 mg/kg cisplatin and 62 mg/kg 5-fluorouracil in six doses/12 days; control rats received 0.9 per cent saline. After treatment, 30 treatment and 30 control rats received a dorsal skin incision which was closed primarily. Wound breaking strength were tested at one, three and five weeks in ten rats from each group. An 8-mm orocutaneous fistula was made in the remaining ten treatment and ten control rats; the rate of closure was noted weekly. Cisplatin and 5-fluorouracil did not significantly impair wound breaking strength at one, three, or five weeks. The rate of closure of the orocutaneous fistula was not effected by cisplatin/5-fluorouracil. The chemotherapy caused severe facial cellulitis and death in four orocutaneous fistula rats. Combined chemotherapy with cisplatin and 5-fluorouracil should not interfere with planned surgical care of head and neck tumors. Concomitant antibiotic coverage, however, is advocated.     

Efficacy of liver wound healing by secondary intent

Nonoperative treatment of liver injury raises questions about liver wound healing (LWH) when the edges are not approximated by primary intent. The efficacy of LWH was studied in 18 dogs and 18 pigs with a total of 108 standard 6-cm injuries. The 36 injuries in six dogs and six pigs were compressed for hemostasis and then allowed to heal by second intent. LWH in these animals was compared to 36 liver wounds in six dogs and six pigs following primary closure (hepatorrhaphy) and 36 liver wounds after omental buttress plus hepatorrhaphy in six dogs and six pigs. Average wound breaking strength (WBS) of liver wounds was studied at 3 weeks (54 wounds) and 6 weeks (54 wounds) with a Chatillon tensiometer and microscopic analysis. The WBS of liver wounds was also compared to normal uninjured liver WBS. The porcine WBS at 3 weeks after healing by second intent (0.31 kg/cm2) was similar to the WBS at 3 weeks after healing by hepatorrhaphy (0.30 kg/cm2) and omental buttress (0.25 kg/cm2). Porcine WBS at 6 weeks after healing by second intent was significantly greater than WBS at 6 weeks after hepatorrhaphy or omental buttress. The canine WBS at 3 weeks after healing by second intent exceeded WBS at 3 weeks after hepatorrhaphy or omental buttress. Canine WBS at 6 weeks after healing by second intent exceeded WBS at 6 weeks after omental buttress and was similar to WBS at 6 weeks after hepatorrhaphy. WBS in all groups paralleled the extent of fibrosis seen on microscopic analysis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Treatment of intracerebral arteriovenous malformations with isobutyl 2- cyanoacrylate: initial clinical experience

From November 1976 to September 1979, 46 patients with intracranial arteriovenous malformations or fistulas participated in a clinical study using isobutyl 2-cyanoacrylate (IBCA), with tantalum, for palliative or preoperative occlusion of the blood supply to the abnormalities. Although failure to obtain satisfactory position of a functioning microcatheter precluded deposition of IBCA 10 times, a total of 51 of a possible 62 feeding vessels were occluded with the tantalum-impregnated glue. The technique, results, and complications are discussed in light of the clinical follow-up, which varied from 12 to 48 months.