Effect of divalent cations on structure-function relationships of the antitumor protein α-sarcin

α-Sarcin binds one Zn(II) cation per protein molecule, with a K_d value of 0.9 mM, determined by equilibrium dialysis experiments. Ca(II), Mg(II), and Mn(II) do not bind to α-sarcin. Cd(II) and Co(II) also behave as Zn(II). The binding produces local modifications on the protein conformation affecting the microenvironment of tryptophan residues. The three cations modify the fluorescence emission of the protein. The near-u. v. circular dichroism spectrum of the protein is also altered. The binding of Zn(II) and related cations does not modify the secondary structure of the protein. The ribonucleolytic activity of a-sarcin is inhibited upon Zn(II) binding, but no alteration of the ability of the protein to aggregate phospholipid vesicles has been observed.     

ETHANOL DECREASES BASAL CYTOSOLIC-FREE CALCIUM CONCENTRATION IN CULTURED SKELETAL MUSCLE CELLS

We analysed the effect of ethanol on basal cytosolic-free calciumconcentration ([Ca²⁺]₁) in cultured rat myocytes. Ethanol causeda dose-dependent decrease of the resting [Ca²⁺]₁). Removal ofethanol was followed by a transitory increase of [Ca²⁺]₁ abovethe basal level. In cells chronically exposed to ethanol, [Ca²⁺]₁normalized to the previous level.     

A functional and clinical reinterpretation of human perineal neuromuscular anatomy: Application to sexual function and continence

Modern anatomical and surgical references illustrate perineal muscles all innervated by branches of the pudendal nerve but still organized into anatomically distinct urogenital and anal triangles with muscles inserting onto a central perineal body. However, these conflict with the anatomy commonly encountered during dissection. We used dissections of 43 human cadavers to characterize the anatomical organization of the human perineum and compare our findings to standard references. We found bulbospongiosus and the superficial portion of the external anal sphincter (EAS) were continuous anatomically with a common innervation in 92.3% of specimens. The superficial transverse perineal muscle inserted anterior and lateral to the midline, interdigitating with bulbospongiosus. The three EAS subdivisions were anatomically discontinuous. Additionally, in 89.2% of our sample the inferior rectal nerve emerged as a branch of S3 and S4 distinct from the pudendal nerve and innervated only the subcutaneous EAS. Branches of the perineal nerve innervated bulbospongiosus and the superficial EAS and nerve to levator ani innervated the deep EAS. In conclusion, we empirically demonstrate important and clinically relevant differences with perineal anatomy commonly described in standard texts. First, independent innervation to the three portions of EAS suggests the potential for functional independence. Second, neuromuscular continuity between bulbospongiosus and superficial EAS suggests the possibility of shared or overlapping function of the urogenital and anal triangles. Clin. Anat. 29:1053–1058, 2016. © 2016 Wiley Periodicals, Inc.     

Childhood acute lymphoblastic leukaemia presenting as jaundice

ABSTRACT An unusual presentation of acute lymphoblastic leukaemia (ALL) in a 6-year-old girl is reported. She presented with unilateral cervical lymphadenopathy, a mixed obstructive/cholestatic jaundice and a progressive pancytopenia. Ultrasound examination revealed an obstructed common bile duct with gross thickening of the wall of the duct and intrahepatic bile duct dilatation. The jaundice resolved with high dose intravenous (i.v.) methylprednisolone. It is postulated that this was due to infiltration of the common bile duct, given the failure to demonstrate any other cause for the bile duct pathology.     

Radiofrequency Catheter Ablation of Ventricular Tachycardia Guided by Nonsurgical Epicardial Mapping in Chronic Chagasic Heart Disease

We report a case of a 63-year-old women with Chagas'disease and recurrent, syncopal VT treated by RF catheter ablation in whom endocardial application of RF energy was guided by nonsurgical epicardial mapping. The procedure was undertaken in the electrophysiology laboratory under deep anesthesia. VT was interrupted after 2.4 seconds of application and rendered noninducible afterwards. Two weeks after the procedure, a distinct morphology VT was induced by programmed ventricular stimulation, and the patient was started on amiodarone, remaining asymptomatic 12 months after the procedure.     

Results of Delivered Therapy for VT or VF in Patients with Third-Generation Implantable Cardioverter Defibrillators

Third-generation implantable cardioverter defibrillators (ICDs) offer tiered therapy and can provide significant advantage in the management of patients with life-threatening arrhythmias. Three different types of ICDs were implanted in 21 patients with ventricular tachycardia (VT) or ventricular fibrillation (VF). Arrhythmia presentation was VT(76%), VF(10%), or both (14%). The mean left ventricular ejection fraction for the group was 32.4 ± 7%. No surgical mortality occurred. Prior to discharge individual EPS determined the final programmed settings of the ICDs. During a mean follow-up of 13 ± 1.4 months (range 2–20) the overall patient survival was 85.7%. No sudden arrhythmic or cardiac death occurred. Twenty of 21 patients (95%) received therapy by their device. In 14 patients (67%) antitachycardia pacing (A TP) was programmed "on," 13 of which was self-adaptative autodecremental mode. There were 247 VT episodes, 231 of which were subjected to ATP with 97% success and 3% acceleration or failure. Low energy shocks reverted all other VT episodes. VF episodes were successfully reverted by a single shock (93%), two shocks (6%), or three shocks (1 %). We conclude that ATP therapy of VT is successful in the large majority of episodes with rare failures, and that VF episodes are generally terminated by a single ICD shock.     

RELATIONSHIP BETWEEN ETHANOL-RELATED DISEASES AND NUTRITIONAL STATUS IN CHRONICALLY ALCOHOLIC MEN

Two-hundred and fifty chronically alcoholic men (mean age, 41± 11 years) entering an alcoholism treatment programwere studied. Detailed clinical history, nutritional assessmentand measurement of muscle strength by electronic myometer wereperformed in each case. In addition, hepatic ultrasonographyand liver biopsy, echocardiography and radionuclide cardiacscanning, and electrophysiological testing of peripheral nerveswere performed when there was clinical evidence of liver disease,cardiomyopathy or neuropathy, respectively. Alcoholic cirrhosiswas diagnosed in 20 cases, skeletal myopathy in 117, dilatedcardiomyopathy in 20 and peripheral neuropathy in 41 cases.No patients with chronic myopathy or cardiomyopathy showed eitherclinical or laboratory evidence of malnutrition. Patients withcirrhosis showed a significantly lower lean body mass than controls(P = 0.03) and significantly lower nutritional protein levelsthan those alcoholics without cirrhosis. Alcoholics with peripheralneuropathy had significantly lower anthropometric parametersand nutrition protein levels than their counter parts (P <0.001). However, in the multivariate analysis, the only independentfactor for developing these complications of alcoholism wasthe total lifetime dose of ethanol (P < 0.001). We concludethat alcohol-related diseases are common in asymptomatic alcoholicmen and these diseases appear to be due to an accumulative toxiceffect of ethanol. Age and nutritional status do not seem toplay a part in the development of such diseases.     

Drug-related behavior change for HIV transmission among American injection drug users

While high risk drug-related behaviors for human immunodeficiency virus (HIV) transmission among injection drug users (IDUs) are asserted to have declined over time in response to the AIDS epidemic, evidence from longitudinal cohorts has been sparse. In a cohort of 810 IDUs (442 seronegatives and 368 seropositives) in Baltimore, we identified drug-related risk behaviors at four consecutive semi-annual visits. Using robust methods for repeated measurements and multiple logistic regression, we estimated the probabilities of maintaining and reducing risk behaviors according to HIV serostatus and time in the study. Seropositive participants were more likely to maintain lower risk behaviors, and behavior maintenance increased with time in study for both seronegative and seropositive IDUs. Greater risk reduction (towards non-use and not sharing injection equipment) was seen among seropositive IDUs, with behavior change occurring soon after enrollment in the study. While behavior changes have been reported, many active IDUs, especially those still at risk for acquiring HIV infection, have not adequately reduced their risk. Continuing prevention programs and efforts in vaccine development are imperative to reduce the risk of HIV infection among IDUs.