Effect of verapamil on renal haemodynamics in a portal hypertensive rat model

In order to investigate the effects of verapamil on renal haemodynamics in rats with portal hypertension, verapamil was given at either a low (0.2 mg/kg) or high (2 mg/kg) dose to rats after portal vein ligation. An approximate 12% decrease in mean arterial pressure followed administration of low dose verapamil, with a significant decrease in cardiac output and renal blood flow, as well as reduced portal pressure, observed; these signs were all indicative of a rise in renal vascular resistance. In contrast, the marked fall in both mean arterial pressure and cardiac output with high dose verapamil, accompanied by a significant decrease in portal pressure and no change in renal blood flow, suggests a reduction in renal vascular resistance. This study shows that the acute effects of verapamil on renal haemodynamics may vary with the dose used. Also, acute verapamil administration tends to decrease renal blood flow to alter the autoregulation of the kidney; thus, caution should be taken in the clinical use of verapamil in the treatment of cirrhosis with portal hypertension.     

HEPATIC MICROSOMAL ENZYME INDUCTION AND ADRENAL CRISIS DUE TO o,p''DDD THERAPY FOR METASTATIC ADRENOCORTICAL CARCINOMA

Two cases are described in which metastatic adrenocortical carcinoma associated with Cushing's syndrome was treated with mitotane (o,p'DDD). The first patient had initially been treated by bilateral adrenalectomy and, whilst responding to mitotane biochemically and by remission of metastases, experienced repeated episodes of adrenal crisis requiring a substantial increase in steroid therapy. The second patient failed to respond to the drug, but evidence of hepatic enzyme induction was noted during its administration. It is suggested that hepatic microsomal enzyme induction can occur in association with treatment with mitotane and that this can lead to an increased destruction of exogenous steroid with clinical consequences.     

Active Involvement of Expectant Fathers in Pregnancy: Some Further Considerations

In this followup to her previous JOGN article, the author presents a review of the recent literature on the man's experience of pregnancy and an expanded concept of active involvement of expectant fathers in pregnancy. Active involvement of the expectant father in pregnancy, namely, the acceptance of the emotional impact of pregnancy and the construction of a mental picture of himself as a participant in the caretaking and nurturing of the infant, may enhance the father's later role in parenting. Recent research suggests that for a man to have the opportunity to participate in the early parenting experience, he must negotiate that future role with his partner during pregnancy and prepare consciously for that style of fatherhood. Much additional research is needed concerning a man's experience of pregnancy and childbearing; the concept of "active involvement" may be a springboard for such research. Better understanding of the process of paternal role development is important in the face of expanding women's roles and the increased interest among men in assuming greater childrearing responsibilities.     

Sudden Death in Recipients of Transvenous Implantable Cardioverter Defibrillator Systems:

INTRODUCTION: Transvenous implantable cardioverter defibrillator (ICD) systems are very effective in preventing sudden death; however, little is known about terminal events and potential causes and mechanisms of sudden death in recipients of these devices. METHODS AND RESULTS: We analyzed 74 cases of sudden death among patients enrolled in several clinical investigations of transvenous ICD systems. Eighty-one percent were men (mean age 68+/-10 years), 86% had coronary artery disease, mean left ventricular ejection fraction was 0.27+/-0.11, and two thirds presented with sustained ventricular tachycardia. The final event was witnessed in 65 patients (81%). Based on reported ICD shocks, documented rhythm, and/or postmortem device data, sudden death was deemed tachyarrhythmic in 49 cases (66%), nontachyarrhythmic in 12 (16%), and indeterminate in the remaining 13 (18%). Multivariate analysis of several clinical and nonclinical factors found advanced age (> 65 years, P = 0.03, odds ratio [OR] 1.75, 95 % confidence interval [CI] 1.05 to 2.92), reduced left ventricular ejection fraction (< 0.35, P < 0.01, OR 3.51, CI 1.66 to 7.40), and having antibradycardia pacing ICDs (P = 0.02, OR 5.26, CI 1.37 to 20.0) to be independent predictors of sudden death. One or more predisposing factors and/or potential causes of sudden death were identified in 21 patients (28%). CONCLUSION: In this select group of transvenous ICD recipients, (1) sudden death was associated with ventricular tachycardia/ventricular fibrillation in at least two thirds of cases, (2) nearly one third of patients had one or more factors, some device related, that could have been associated with sudden death, and (3) death ensued despite appropriate ICD therapies and, in many cases, external resuscitation, suggesting acute adverse events as common terminal factors.     

Expression of Melan-A in Spitz,Pigmented Spindle Cell Nevi,and Congenital Nevi: Comparative Immunohistochemical Study

The expression of the antibody Melan-A in 27 benign melanocytic skin lesions (10 congenital nevi, 10 Spitz nevi, and 7 pigmented spindle cell nevi) was compared to that of S100 protein and HMB-45. To evaluate the role of Melan-A in differentiating melanocytic and nonmelanocytic lesions we assessed a number of benign nonmelanocytic skin lesions including neurofibromas, granular cell tumors, and dermatofibromas. Melan-A had an identical staining pattern to S100 protein in the melanocyte population of all lesions, but had the advantage of only staining cells of melanocytic lineage and no other cell types. HMB-45, although staining the junctional components of all lesions with a junctional component, showed varied intensity and distribution in the dermal components. Melan-A is much cleaner than S100 protein, having no background staining, and in skin appears to be specific for melanocytes. The nonmelanocytic lesions did not express Melan-A.     

Severe myocardial injury and rhabdomyolysis from acute oral amphetamine abuse

We report a case of a previously healthy young man who developed severe myocardial injury and rhabdomyolysis after a single oral ingestion of amphetamine. Such major toxicity is more usually associated with the use of intravenous amphetamine or chronic amphetamine abuse. Both physicians and potential drug users need to be aware that a single oral ingestion of amphetamine may produce severe, life-threatening toxicity.     

Lead-Induced Tricuspid Stenosis—Successful Management by Balloon Angioplasty

We describe a case of tricuspid stenosis in a young woman 11 years after endocardial ventricular lead implantation. The cause of the stenosis appears to have been perforation of the septal leaflet by the lead at the time of insertion. We further describe successful management with percutaneous balloon valvuloplasty without the need for lead removal.     

Utility and Safety of Axillo‐subclavian Venous Imaging with Carbon Dioxide (CO2) Prior to Chronic Lead System Revisions

Background: Prior to attempting placement of one or more electrodes to revise existing rhythm control devices, patency of the central veins should be documented, in view of a high incidence of significant chronic occlusions. Since iodinated contrast venography may be contraindicated in select situations, imaging of the axillo‐subclavian venous system with gaseous carbon dioxide (CO₂) was evaluated prospectively in 23 consecutive individuals who were considered for revision of previously implanted pacemaker or automatic cardioverter defibrillator lead systems. Methods: Approximately 20 mL of CO₂ were manually infused via CO₂ primed injection tubing into a vein at or above the level of the antecubital fossa ipsilateral to the side of prior lead placements. Digital subtraction imaging over the axillo‐subclavian region, lower neck, and mediastinum was performed. Formal interpretation was obtained from one of three interventional radiologists and at least one electrophysiologist. Results: Significant venous occlusions were identified in five (22%) patients. Vascular access utilized for the subsequent 18 revisions performed included the imaged patent ipsilateral vein in 14 patients and the contralateral, right‐sided subclavian venous system in three patients. One patient required epicardial left ventricular lead placement. There were no complications from venography. Conclusions: Axillo‐subclavian venography with gaseous CO₂ in patients undergoing pacemaker or implantable cardioverter defibrillator lead revisions is feasible and safe when use of iodinated dye is contraindicated. This technique should be employed in patients with azotemia, dye contrast allergies, or significant inflammation in the vicinity of the intravenous line insertion. (PACE 2010; 790–794)     

Gastric contents in pediatric patients following bone marrow transplantation

Background: Graft versus host disease (GVHD) of the gut is thought to delay gastric emptying and so may increase the risk of aspirating retained contents while under anesthesia. Knowing that gastric emptying is delayed in patients with GVHD might lead one to choose to intubate the trachea for all patients with suspected GVHD, who present for diagnostic esophagogastricduodenoscopy (EGD). We are not aware of published data that gives specific guidance as to the need for intubation in the pediatric bone marrow or stem cell transplantation (BMT) population. This review was intended to evaluate the gastric contents (pH and volume) in this group of patients, to provide anesthesiologists with data that would inform their decisions about airway management for these patients. Methods: Retrospective chart review of patients ≤19 years of age undergoing EGD between 2004 and 2006. Gastric content volume and pH were measured in addition to underlying disease state and treatment. We compared BMT patients with suspected GVHD to nontransplant patients with other underlying gastrointestinal conditions. Results: Data were obtained for 77 patients post‐BMT undergoing EGD, including 40 patients whose biopsies and endoscopic findings were positive for GVHD, and 37 patients with no demonstrable GVHD. Records of 144 non‐BMT patients undergoing EGD within the same study period were also reviewed. Conclusion: Patients in the BMT group overall did not have higher volumes when compared to non‐BMT patients. A secondary comparison of BMT patients who were found to have GVHD vs BMT patients without GVHD suggests that gastric content volume may be elevated with GVHD. Patients in the BMT group had statistically significantly higher gastric pH than patients in the non‐BMT group. It is possible that the higher gastric volume in the GVHD‐positive group could put them at slightly higher risk for aspiration, but the severity of any pneumonitis, should aspiration occur, might be mitigated, by the tendency toward a higher gastric pH in the BMT patients.     

An Overview of Dioxin-Like Compounds,PCB, and Pesticide Exposures Associated with Sexual Differentiation of Neuroendocrine Systems,Fluctuating Asymmetry,and Behavioral Effects in Birds

Dioxin, polychlorinated biphenyls (PCBs), and pesticides impact neural systems in birds due to interference with sexual differentiation. Early endocrine disrupting chemical (EDC) effects may delay maturation and have long-term effects on lifetime reproduction, especially in precocial birds that complete sexual differentiation prior to hatch. Semi-altricial and altricial species appear more resilient to EDC effects and show a gradient in sensitivity, especially in the neuroplastic song system. Embryonic steroid exposure occurs via maternally deposited steroids followed by embryo produced hormones; EDCs potentially affect these developing systems. As such, EDCs can impact lifelong fitness by acting on neural systems that regulate reproduction, metabolism, and behavior.