Additive interactions of calcitonin gene-related peptide and calcitonin on pancreatic exocrine function in conscious dogs

By convention, establishing a physiologic role for a gut peptide requires demonstration of biologic activity that can be reproduced by exogenous administration of the peptide in amounts that yield plasma concentrations that are not higher than those found after a meal. We have tested the hypothesis that the combined action of two inhibitory peptides may lower the effective doses of each. We further hypothesize that combined peptide responses may be responsible for the action of peptide hormones that have been difficult to demonstrate as physiologically relevant mediators, when examined as independently acting substances. In conscious dogs prepared with chronic pancreatic cannulas, stimulated pancreatic exocrine secretions were depressed in a dose-related manner by intravenous infusions of calcitonin (CT) and calcitonin gene-related peptide (CGRP). Doses of 2.0 nmol/kg/hr of both CT and CGRP yielded maximal inhibition of stimulated secretions of both bicarbonate (greater than 85% inhibition) and protein (greater than 55% inhibition). The lowest effective dose for either CT or CGRP, given alone, was 0.75 nmol/kg/hr, but when infused simultaneously, each at the subthreshold dose of 0.50 nmol/kg/hr, significant inhibition of protein and bicarbonate secretion was achieved. Combined infusions of the submaximal dose of 0.75 nmol/kg/hr resulted in an enhanced inhibitory response. To prove that this effect is not simply combined activation of a common receptor, we tested peptide YY (0.1 to 0.5 nmol/kg/hr) combined with CGRP and obtained similar results. Because a meal simultaneously releases a large number of active peptides, we speculate that such potentiated responses do occur physiologically. Cooperative interaction with other agents may be the primary mode of action for certain gut peptides.     

Osteoblastoma: experience with 23 patients.

A retrospective review of 23 patients with osteoblastoma was undertaken in an attempt to answer questions concerning the aggressiveness and potential malignancy of this tumour. Demographic information confirmed that recorded in the literature. There was no suggestion of malignant potential, but, significantly, one tumour persisted, with local recurrence after 11 operations over a period of 27 years. A second tumour, a spinal lesion, occurred (still in a benign form) after a symptom-free period of 17 years. Recognition of aggressive features clinically, radiologically and histologically suggests the need for more aggressive surgical treatment, and late recurrence indicates the need for a more guarded prognosis and longer follow-up.     

Prevention of vascular injuries in revision total hip replacement.

Iliac-vessel injury from total hip arthroplasty is associated with hemorrhagic complications and an increased death rate. The authors identified seven patients who had severe medial displacement of the acetabular prosthesis and associated vascular injury to the iliac vessels after total hip replacement. One patient had two hip replacements. Preoperative findings included a pelvic mass (three hips), pelvic pain (eight), radiologic evidence of cement in the pelvis (three) and the acetabular prosthesis in the pelvis (eight), computed tomographic evidence of cement in the pelvis and proximity of the prosthesis to the iliac vessels (four), and arteriography showing displacement or compression of the iliac vessels (seven). Operative management in all cases involved medial exposure, mobilization and repair of the iliac vessels before revision of the hip prosthesis. Postoperative complications were deep vein thrombosis (three), in spite of prophylaxis, and occlusion of a vein interposition graft (one) requiring placement of a femoral crossover graft. There were no deaths, amputations or hemorrhagic complications. The authors advocate preoperative identification of patients who have iliac-vessel involvement by their total hip prosthesis and initial medial extraperitoneal exposure and repair of these vessels before removal of the displaced acetabular prosthesis.     

Older adults’ preferences for exercising alone versus in groups: Considering contextual congruence

Background: A growing body of research suggests that older exercisers prefer to exercise alone rather than in group-based settings. One limitation of these studies, however, has been that researchers have failed to take into account the age-related characteristics of groups when asking adults about their preferences for exercise settings.Purpose: The overall purpose of this study was to examine the exercise preferences of 947 adults for involvement in standard exercise classes populated by participants from various categories across the age spectrum.Results: The results revealed that when faced with the prospect of exercising with considerably older or younger exercisers, participants found such an exercise context to be largely unappealing. However, in accordance with the basic tenets of self-categorization theory, the results revealed that older and younger adults alike express a positive preference for exercising in standard exercise classes comprised of similarly aged participants.Conclusions: The findings of this study challenge a growing call for exercise interventions for older adults to be primarily directed at the individual-level, and suggest that group-related intervention strategies may indeed be attractive to older exercisers.     

Plate fixation of open fractures of the tibia

The results of immediate plate fixation of 97 open fractures of the tibial shaft in 95 patients are reported. Significant joint stiffness occurred in 11.4% and angular malunion of greater than 5 degrees in any plane was seen in 3.1%. The infection rate was 10.3%. However, even in those cases which develop delayed union or other complications, plate fixation of open fractures can produce excellent recovery of limb function.     

3,5-甾二烯化合物的合成及抗早孕活性

以18-甲基-17β-羟基-17α-乙炔基-雌甾-4-烯-3-酮(18-甲基炔诺酮),17β-羟基-17α-乙缺基-雌甾-4-烯-3-酮(炔诺酮),17β-羟基-17α-乙炔基-雄甾-4-烯-3-酮(妊娠素)和17a-羟基孕甾-4-烯-3,20二酮(17α-羟基黄体酮)为原料,经NaBH,还原、脱水、双键转位和酯化等反应合成一系列3,5-甾二烯化合物,用¹HNMR和MS证明了它们的结构。动物筛选结果表明,17β-丙酰氧基-17α-乙炔基-雌甾-3,5-二烯(IV_b2有明显的抗早孕活性。中断早期妊娠的作用似与其雌激素活性有关。     

Glucose preferences in wild and domestic guinea pigs

Male wild (Cavia aperea) and domestic (C. porcellus) guinea pigs were tested in two-bottle choice tests for preferences between glucose solutions of different concentrations and de-ionized water. Wild males showed significant preferences for concentrations between 0.025 and 0.4 M glucose while domestic males preferred only the 0.2 M glucose solution to de-ionized water. C. aperea males also consumed significantly greater volumes of liquid per kg body $\text{wt.}{}^{\mathrm{<mtext>3</mtext><mtext>4</mtext>}}$ during the glucose tests than did the C. porcellus males. These comparative results contrast sharply with those obtained by other authors with wild and domestic Norway rats.