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Biomedical subjects

R Warren

Publications and source records attributed to R Warren.

At least 163 records · Page 9Linked to original sources
PubMed1991

Fasted state impedes recovery of porcine hepatic oxygen consumption after warm hepatic ischemia.

The most effective means to prepare the hepatic donor liver for harvest, preservation, and transplantation are not known. Studies have shown that in combination with an injury to the liver, fasting reduces hepatic function. This study randomized 20 market pigs, 20 to 45 kg, to an overnight fast (fed group) or a 42-hour fast (fasted group). Under general anesthetic perfusion of the portal vein and hepatic artery were controlled. Studies were performed at high flow (30 ml/min/kg portal flow and 10 ml/min/kg arterial flow) and after a 90-minute period of warm ischemia (no flow). Flow was restored at 25% of the original (low flow), then increased to 50% of the original (medium flow). After the ischemic insult, the fed group improved hepatic oxygen consumption at a faster rate than the fasted group (p less than 0.05 by ANOVA). In addition, significant differences were noted between the fed and fasted groups in the amount of insulin delivered by the portal venous system to the liver (p less than 0.001 by ANOVA). Hepatic oxygen consumption was related to insulin delivery (r2 = 0.46; p less than 0.001) for both groups. The data suggest that acute changes in the nutritional status of both the donor and the recipient may affect hepatic recovery from ischemia.

Amino Acids↗
PubMed1990

Relationships between catastrophic cognitions and body sensations in anxiety disordered, mixed diagnosis, and normal subjects.

Clark's (Behaviour Research and Therapy, 24, 461-470, 1986) cognitive model proposes that panic attacks result from the catastrophic misinterpretation of certain body sensations. The present study examined correlations between feared body sensations and catastrophic cognitions. It was hypothesized that regardless of diagnostic status meaningful correlations between sensations and cognitions would be obtained. Three groups--anxiety disordered patients (n = 33), nonanxiety disordered patients (n = 57), and normals (n = 60)--completed the Agoraphobic Cognitions Questionnaire and the Body Sensations Questionnaire. Results generally supported the hypothesis and the cognitive model of panic and anxiety. Limitations of the correlational methodology are discussed, and treatment implications are noted.

Agoraphobia↗
PubMed1990

Propranolol treatment of paruresis (psychogenic urinary retention): a brief case report.

Propranolol, a nonselective beta-blocker, was administered to a client with paruresis (psychogenic urinary retention) following a novel in vivo exposure treatment. The client did not report a significant increase in his ability to urinate in public facilities during subsequent exposures. Rationale for including propranolol as an adjunct to exposure therapy of paruresis is discussed.

Adult↗
PubMed1990

Recombinant IL-4 inhibits IL-6 synthesis by adherent peripheral blood cells in vitro.

IL-4 has been shown to participate in interregulatory networks with other cytokines including IL-2, IFN-gamma, IL-1 beta, and TNF-alpha. The ability of recombinant IL-4 (rIL-4) to modulate the synthesis and release of IL-6 was investigated in vitro. LPS-stimulated adherent cells (AC) from human peripheral blood secreted IL-6 as determined by ELISA and bioassay with the B9 hybridoma cell line. The secretion of IL-6 peaked between 12-16 h after LPS stimulation. The addition of rIL-4 inhibited LPS-induced IL-6 production measured at 8 h. The inhibitory effect of rIL-4 on IL-6 secretion was dose-dependent and occurred at doses as low as 0.001 U/ml (0.01 pg/ml). Recombinant IL-4 was added to the cultures for various periods and removed by aspiration of the medium and washing the cells. The subsequent LPS-induction of IL-6 secretion was reduced in cultures exposed to rIL-4 for as little as 5 minutes indicating that the effect of rIL-4 on the monocytes was rapid and irreversible. Northern blot analysis revealed that the effect of rIL4 on LPS-induced production of IL-6 by AC occurred at least in part at the level of transcription. In contrast, PMA-induced IL-6 gene transcription was not affected by rIL-4. These findings indicate that rIL-4 can regulate the synthesis of IL-6 by adherent peripheral blood mononuclear cells.

Acute-Phase Reaction↗
PubMed1990

The lateral arm fascial free flap: its anatomy and use in reconstruction.

Free fascial transfer has been used for reconstruction of gliding surfaces of the upper and lower extremities or when thin, pliable coverage is required (hand, heel, nose, and ear). In our experience with the lateral arm fasciocutaneous flap, we have found that the fascia alone is an excellent source of tissue for free flap transfer. A thorough investigation of the microscopic, gross, and radiographic anatomy of the lateral arm fascia was undertaken by the study of 25 fresh cadavers. Vascular pathways were mapped, their locations were analyzed, and then they were correlated with the elevation, design, and transfer of the flap. The lateral arm has a large fascial component located anterior and posterior to the lateral intermuscular septum, which itself lies between the triceps and the brachialis and brachioradialis muscles. It is perfused by the posterior radial collateral artery (PRCA), one of the terminal branches of the profunda brachii. This vessel (PRCA) provides at least four fascial branches from 1 to 15 cm proximal to the lateral epicondyle, the largest of which is located an average of 9.7 cm superior to the lateral epicondyle. Fascia up to 12 x 9 cm may be used with good axial perfusion. The histologic cross sections demonstrate the complex anatomy of the fascia itself, as well as its relation to the nutrient vessels. We have applied the lateral arm fascial flap in five cases of upper extremity reconstruction. We have also found this flap valuable in preservation of underlying anatomic detail for total reconstruction of the ear and nose when local tissue and more conventional flaps were not available.

Adult↗
PubMed1989

Mediation of anorexia by human recombinant tumor necrosis factor through a peripheral action in the rat.

Human recombinant tumor necrosis factor (TNF) produces significant anorexia in the rat which persists for up to 24 h after a single dose (5 micrograms/325 g rat). Dose-response studies indicate similar potencies for TNF following central or peripheral administration. Brain 125I-TNF levels were more than 100-fold greater after intracerebroventricular than i.v. injection, whereas blood levels of radioactivity were quite similar following both routes of administration. Gel filtration chromatography and precipitation by trichloroacetic acid showed that the radioactive label which exited the central nervous system was associated with intact TNF. The rapid effusion of 125I-TNF from the central nervous system resulted in detection of similar levels of the cytokine in a number of important target tissues (skin, muscle, fat) relative to that detected after peripheral administration. After i.v. or intracerebroventricular administration, blood levels of TNF declined rapidly to nearly undetectable levels over 4 h. However, the anorexia induced by TNF was sustained, and feeding remained depressed between 6 and 24 h postadministration. These observations suggest that TNF produces its anorectic effects at peripheral sites, possibly through mediators.

Animals↗
PubMed1989

Quantitative study of glutamic acid decarboxylase-immunoreactive neurons and cytochrome oxidase activity in normal and partially deafferented rat hindlimb somatosensory cortex.

Somatosensory cortex reorganizes following restricted deafferentation so that deprived neurons acquire new receptive fields. Electrophysiological data suggest that a decrease in inhibition might be one of the mechanisms contributing to these changes. This hypothesis was tested by evaluating quantitatively glutamic acid decarboxylase (GAD) immunoreactivity and cytochrome oxidase (CO) activity in normal and partially deafferented rat hindlimb somatosensory cortex. In normal animals, there were laminar differences in the frequencies of GAD+ cells that correlated with the levels of CO activity. Two weeks after transection of the sciatic nerve, CO levels were reduced in all layers of the hindlimb somatosensory cortex contralateral to the nerve transection whereas the frequencies of GAD+ cells were unchanged except in layer IV where a 16% decrease was observed. This observation is consistent with the hypothesis that the expression of GAD in layer IV is partially controlled by the amount of afferent input. The ability of novel inputs to develop stable patterns of excitation in deafferented somatosensory cortex may depend upon the reduction of GABAergic inhibition which follows deafferentation.

Animals↗
PubMed1989

Death by default.

Explore the source record for details and available documents.

Emergency Service, Hospital↗
PubMed1989

Cognitive bias and irrational belief as predictors of avoidance.

Cognitive bias, i.e. overestimates of subjective probability and cost of catastrophic events, and irrational belief were explored as predictors of avoidance. Three groups-anxiety disordered clients, a mixed group of clinic outpatients, and normals--were administered several self-report inventories. Multiple regression analyses were used to investigate a modified version of the Agoraphobic Cognitions Questionnaire, the Belief Scale, and the Body Sensations Questionnaire as predictors of avoidance, as measured by the Mobility Inventory. It was hypothesized that frequency x probability x cost of catastrophic cognitions (and the occurrence of the events they represent) would be a better predictor of avoidance than frequency alone. It was also hypothesized that irrational thinking would be a significant predictor of avoidance. The results generally supported the hypotheses, with subjective probability emerging as a particularly potent predictor of avoidance. Theoretical and clinical implications are discussed.

Adult↗
PubMed1989

Ephedrine-induced thermogenesis as an adjunct to cognitive restructuring and covert conditioning: a proposal for treatment of obese individuals.

Experimental investigators have discussed the therapeutic potential of ephedrine as a thermogenic agent in the treatment of obese individuals. Because research into thermogenesis and the role of sympathetic nervous system stimulation in weight control primarily has emphasized pharmacological interventions, the authors suggest that cognitive restructuring and covert conditioning procedures could be valuable psychotherapeutic additions to a pharmacologically derived weight-loss regimen. Furthermore, it is concluded that additional clinical research is necessary to determine the efficacy of integrating ephedrine therapy and cognitive-behavioral psychotherapeutic procedures as adjuncts to a multidimensional program for treating obesity.

Adipose Tissue↗
PubMed1988

Measurements of placental, decidual, and fetal proteins before and after chorionic villus sampling.

Circulating placental [human chorionic gonadotrophin (hCG), Schwangerschafts protein 1 (SP1), pregnancy-associated plasma protein A (PAPP-A), decidual (pregnancy protein 12 (PP12), and fetal alphafetoprotein (AFP)] proteins were measured immediately before and within 1 h in 18 women undergoing diagnostic chorionic villus sampling (CVS) in the first trimester. An elevation of serum AFP levels was consistently seen, while fluctuations in excess of 10 per cent of the pre-CVS levels of SP1 and PP12 were seen in the majority of patients. Fluctuations in hCG and PAPP-A were consistently less than 10 per cent of pre-CVS values. Post-CVS changes in levels were not apparently associated with any feature of the technique, the pregnancy, or its outcome (one missed abortion). As feto-maternal haemorrhage is a common event, anti-D should be offered to rhesus-negative women undergoing CVS. In the prediction of subsequent miscarriage, only hCG and PAPP-A measurements should be considered.

Abortion, Spontaneous↗
PubMed1988

Variable expression of Lactobacillus casei cell wall-induced coronary arteritis: an animal model of Kawasaki's disease in selected inbred mouse strains.

Mice receiving a single intraperitoneal injection of Lactobacillus casei cell wall fragments in aqueous suspension develop an asymmetric inflammatory coronary arteritis which histologically mimics the lesions seen in the coronary arteritis of children with Kawasaki's disease. A large variety of mice with genetically determined defects of the immune system were evaluated in this study to determine the influence of these defects on disease expression. Only the C3H/Hej mouse with defective macrophage function and poor production of IL-1 and TNF following stimulation with LPS failed to develop disease. This study suggests that further evaluation of macrophage function in children with Kawasaki's disease may provide important clues to its pathogenesis and treatment.

Acute Disease↗