Hypertrophy of the masseter muscle. Clinical aspects--etiology--therapy

Masseteric muscle hypertrophy is a problem occurring in daily practice. Main complaints are isolated swelling of the masseteric muscle, myalgia, and functional disturbances of the parotid gland. Diagnosis is effected by inspection, palpation and anterior posterior radiograph. Sialography, CT, EMG are rarely used. Main points in the discussion of the aetiology are congenital genesis, the psychological factor, habits and occlusal disorders. The therapy consists of surgical reduction of the hypertrophied muscle as well as of conservative methods.     

Canine myocardial reperfusion injury: protection by a free radical scavenger, N-2-mercaptopropionyl glycine

Oxygen-derived free radicals and their metabolites may contribute to the extension of irreversible cellular injury, which occurs on reperfusion of the previously ischemic myocardium. Therefore, therapy directed against the toxic effects of reactive oxygen species may provide protection to the ischemic myocardium, which undergoes subsequent reperfusion. We evaluated the effectiveness of N-2-mercaptopropionyl glycine (MPG), a free radical scavenger, to limit the extent of irreversible injury resulting from 90 min of ischemia followed by 6 h of reperfusion in a canine model of myocardial infarction. In three groups of dogs, MPG (20 mg/kg) was administered as a constant infusion into the left atrium. Group I received MPG for 2 h, starting 15 min before occlusion of the left circumflex coronary artery and ending 15 min after reperfusion. Group II received MPG for 1 h, starting 15 min before reperfusion. Group III received MPG for 1 h beginning 45 min after reperfusion. Each group was compared with its respective saline control group. Infarct size was reduced by 35% in Group I (32.2 +/- 5.1% vs. 47.7 +/- 3.4% of the area at risk, p less than 0.05) and Group II (31.4 +/- 3.6% vs. 47.5 +/- 5.1% of the area at risk, p less than 0.025) in comparison with the saline treated control animals. In contrast, in Group III infarct size did not differ significantly from the saline-treated control group (45.9 +/- 3.3% vs. 47.7 +/- 3.5% of the area at risk). The percent of left ventricle at risk did not differ among the groups. The beneficial effects of MPG could not be explained on the basis of hemodynamic differences. In addition, MPG did not influence regional myocardial blood flow. In vitro studies indicated that MPG effectively scavanges O2- generated by the hypoxanthine-xanthine oxidase reaction, as well as by PMA-activated polymorphonuclear leukocytes. Based on these observations, we propose that MPG exerts its beneficial effects by protecting against free radical-mediated damage during the early phase of reperfusion.     

Obstructed voiding in the female

Bladder outlet obstruction in women is rare. The characteristics and aetiology of the condition in 163 females are discussed and their relation to treatment evaluated.     

Distinct p53/56lyn and p59fyn domains associate with nonphosphorylated and phosphorylated Ig-alpha.

Among the earliest detectable events in B-cell antigen receptor-mediated signal transduction are the activation of receptor-associated Src-family tyrosine kinases and the tyrosine phosphorylation of Ig-alpha and Ig-beta receptor subunits. These kinases appear to interact with resting B-cell antigen receptor complexes primarily through the Ig-alpha chain antigen receptor homology 1 (ARH1) motif. Recent studies showed a dramatic increase in the amount of Src-family kinase p59fyn bound to Ig-alpha when ARH1 motif tyrosines were phosphorylated. To explore the submolecular basis of these interactions, we conducted mutational analysis to localize sites in p53/56lyn and p59fyn that bind nonphosphorylated and phosphorylated Ig-alpha. Here we report that distinct regions within these kinases bind nonphosphorylated and phosphorylated Ig-alpha ARH1 motifs. The N-terminal 10 residues mediate binding to the nonphosphorylated Ig-alpha ARH1 motif. Association with the phosphorylated Ig-alpha ARH1 motif is mediated by Src homology 2 domains. These findings suggest a mechanism whereby ligand-induced Ig-alpha tyrosine phosphorylation initiates a change in the orientation of an associated kinase that may alter its activity and/or access to substrates and other effectors.     

cAMP production via the adenylyl cyclase pathway is reduced in RCS rat RPE.

cAMP production was investigated in retinal pigment epithelium (RPE) cells isolated from normal rats and from rats with an inherited retinal dystrophy (Rdy/p+). In normal RPE cells, 5'-[N-Ethylcarboxamido]-adenosine (A2 receptors) produced a fivefold increase in the level of cyclic adenosine monophosphate (cAMP) over basal levels. However, only a onefold increase in cAMP was observed in dystrophic cells. cAMP production by prostaglandins E1 and E2 (prostaglandin receptors) in dystrophic RPE cells was only 29-38% of the level observed in normal cells. Direct stimulation of adenylyl cyclase by 10 mumol/l forskolin increased cAMP levels in normal RPE cells by 90 fold over basal, but only by sixfold in the dystrophic cells. These data suggest there may be a defect in the adenylyl cyclase signaling pathway in dystrophic RPE cells.     

Self-efficacy in weight management

Self-efficacy is an important mediating mechanism in advancing understanding of the treatment of obesity. This study developed and validated the Weight Efficacy Life-Style Questionnaire (WEL), improving on previous studies by the use of clinical populations, cross-validation of the initial factor analysis, exploration of the best fitting theoretical model of self-efficacy, and examination of change in treatment. The resulting 20-item WEL consists of five situational factors: Negative Emotions, Availability, Social Pressure, Physical Discomfort, and Positive Activities. A hierarchical model was found to provide the best fit to the data. Results from two separate clinical treatment studies (total N = 382) show that the WEL is sensitive to changes in global scores as well as to a subset of the five situational factor scores. Treatment programs may be incomplete if they change only a subset of the situational dimensions of self-efficacy. Theoretical and clinical implications are discussed.