Influence of shock-induced fighting and social factors on pituitary-adrenal activity, prolactin and catecholamine synthesizing enzymes in rats

The present experiment investigated changes in pituitary-adrenal activity, prolactin and catecholamine synthesizing enzymes in rats exposed to electric shocks in pairs or individually, in comparison to animals receiving no shock and tested in pairs or alone. Pairs of rats repeatedly exposed to electric shocks displayed a lower activation of the pituitary-adrenal system but a stronger activation of the sympathetic-adrenal medullary system than rats shocked individually. There was no differential release of prolactin according to the social setting in which shock occurred. Social factors by themselves influenced plasma corticosterone levels but not plasma levels of ACTH and prolactin nor catecholamine synthesis. The results are discussed in relation to the postulated beneficial effects of fighting on physiological activation produced by electric shock.     

Peripheral injections of vasopressin control behavior by way of interoceptive signals for hypertension

The stimulus properties of peripheral injections of vasopressin were assessed using conditioned taste aversion techniques. Conditioned taste aversion induced by vasopressin was blocked by prior exposure to vasopressin but not to another aversive agent, apomorphine. Prior exposure to behaviorally equivalent doses of another hypertensive agent, angiotensin II, blocked also conditioned taste aversion induced by vasopressin and this effect was fully reciprocal, since prior exposure to AVP blocked the aversive effect of angiotensin II. The protection offered by prior exposure to angiotensin II was not due to an endogenous release of AVP since the aversive properties of angiotensin II were not blocked by administration of a specific antagonist of the vasopressor effects of vasopressin. These data suggest that the interoceptive cues which are responsible for the conditioned taste aversion induced by vasopressin are related to the hypertensive action of this peptide.     

Pentoxifylline and insulin-like growth factor-I (IGF-I) abrogate kainic acid-induced cognitive impairment in mice

Hippocampal insults involving neuroimmune mechanisms can impair learning and memory in a variety of tasks. The present study was designed to assess the effect of pentoxifylline, an inhibitor of tumor necrosis factor alpha (TNFalpha), and insulin-like growth factor-I (IGF-I) on kainate (KA)-induced impairment in spatial memory. Male mice received a subcutaneous injection of a dose of KA (15 mg/kg) that had no cytotoxic effect on hippocampal neurons as confirmed by Fluorojade B staining. This dose resulted in an impairment of spatial memory in a two-trial recognition task 11 days later. Intraperitoneal administration of pentoxifylline (200 mg/kg) abrogated this effect. Repeated intracerebroventricular injection of IGF-I (2 microg/mouse on day 1 followed by 1 microg/mouse on days 2-5) abrogated KA-induced deficits in spatial memory whereas acute IGF-I (2 microg/mouse on day 1 only) had mixed effects. These findings indicate that endogenous TNFalpha is probably involved in the detrimental effects of kainate on cognition and that exogenous IGF-I can oppose these effects, probably by antagonizing TNFalpha-induced neurotoxicity.     

Early postoperative hepatic sonography as a predictor of vascular and biliary complications in adult orthotopic liver transplant patients

OBJECTIVE: Our objective was to quantitatively assess the value of early posttransplantation hepatic artery resistive indexes in predicting vascular and nonvascular complications in adult orthotopic liver transplant (OLT) patients. MATERIALS AND METHODS: Between 1999 and 2001, 110 consecutive adults received grafts. Doppler sonographic graft evaluations measured main, right, and left resistive indexes within 24 to 48 hr after surgery (normal resistive index cutoff, 0.6). Clinical, operative, procedural, and radiologic reports were reviewed for vascular and biliary complications. Frequency, Student's t test, logistic, and regression statistical analyses were performed. RESULTS: even patients (6.4%) had vascular complications, including two (1.8%) hepatic artery and two (1.8%) hepatic vein stenoses, one (0.9%) hepatic vein thrombosis, two (1.8%) portal vein thromboses, and one (0.9%) thrombosis and two (1.8%) stenoses of the inferior vena cava (IVC). In 19 patients (17.3%), biliary complications included anastomotic strictures and leaks 1 week to 18 months after transplantation. In 11 patients (10%), sonographically large hematomas required surgical evacuation. In grafts with vascular complications or large hematomas, the mean early posttransplant main, right, and left indexes were significantly lower (< or = 0.6) than without these complications (p < 0.01). In grafts with and without biliary complications, mean early posttransplant main, right, and left indexes did not differ significantly. CONCLUSION: In adult OLT patients, low early posttransplant hepatic artery resistive indexes were sensitive (100%) and specific (80%) predictors for vascular complications (e.g., hepatic artery, portal vein, hepatic vein, and IVC) but not for biliary complications. All patients with indexes less than 0.6 within 24-48 hr after surgery should be monitored closely for vascular complications.     

Roentgenographic evaluation of the augmented breast.

We performed a retrospective study to determine the sensitivity of mammography in detecting breast cancer arising in women with augmented breasts. Of eight women with breast implants in whom breast cancer developed, six had mammograms before biopsy. Only two of the six cancers were identified mammographically (sensitivity = 33%), and one of these two was seen only in retrospect. In both cases, the mammographic findings suggested a benign rather than a malignant process. All eight women had a palpable mass and early disease, and all are clinically disease-free at present. The sensitivity of mammography in detecting palpable cancers in a control group of women without implants was 92% (118 of 128). For tumors of 2 cm or less, the sensitivity was 88% (58 of 66). These results suggest that the sensitivity of mammography in detecting breast cancer is decreased when implants are present. Further investigations are needed to determine the effects of prostheses on mammographic evaluations.     

Chimerism in the immunohematology laboratory in the molecular biology era

Dual or multiple cell populations, induced by chimeras, have been the subject of many studies. This long-standing fascination with chimeras has revealed a good deal of knowledge about human inheritance. Although historically most chimeras were caused by natural events, certain current medical intervention therapies are increasing the number of situations that can lead to a mixed cell population, that is, the chimeric condition, in humans. Medical therapies such as transfusion, stem cell transplantation, kidney transplantation, and artificial insemination induce temporary and sometimes permanent chimeras. Such natural or therapeutically induced presentations of chimerism can present challenging issues to the clinical immunohematology laboratory with regard to interpretation of results and subsequent patient management. The purpose of this review was to highlight some of these chimeric states and hypothesize how testing DNA from various tissues can cause apparent discrepancies between phenotype and genotype results.