Epicardial Sock Mapping Following Monophasic and Biphasic Shocks of Equal Voltage with an Endocardial Lead System

Mapping After Monophasic and Biphasic Shocks. Introduction: The reason for the increased defibrillation efficacy of biphasic shocks over monophasic shock is not definitely known. Methods and Results: In six anesthetized pigs, we mapped the epicardium after transvenous defibrillation shocks to compare the activation patterns following successful biphasic shocks with unsuccessful monophasic shocks of the same voltage. The heart was exposed and a 510-electrode sock with approximately 4-mm interelectrode spacing was pulled over the entire ventricular epicardium and sutured to the pericardium. Defibrillation catheters were placed in the right ventricular apex and in the superior vena cava. Paired monophasic 12 msec and biphasic 6/6 msec defibrillation shocks were given using an up-down protocol to keep shock strength between the defibrillation thresholds for the two waveforms so that the biphasic shock was successful while the monophasic shock was not. Activation fronts immediately following 60 paired shocks were recorded and analyzed by animated maps of the first derivative of the electrograms. The ventricles were divided into apical (I), middle (II), and basal (III) thirds, and early sites, i.e., the sites from which activation fronts first appeared on the epicardium following the shock, were grouped according to their location. Postshock intervals, i.e., the time from the shock until earliest epicardial activation occurred, were also determined. No ectopic activation fronts followed the shock in 20 biphasic episodes. In the other 40 paired episodes, the number of early sites was smaller after biphasic shocks than after monophasic shocks (monophasic: 198 (total), 3.3 ± 0.9 (mean ± SD) per shock episode; biphasic: 67, 1.1 ± 1.0, P < 0.05]. For biphasic but not monophasic shocks, early sites were less likely to arise from the middle (II) and basal (III) thirds than from the apical third (I) [monophasic: I: 84 (42%), II: 68 (34%), III: 46 (23%); biphasic: I: 49 (73%), II: 10 (15%), III: 8 (12%), P < 0.05]. Postshock intervals were significantly shorter for monophasic shocks (54 ± 14 msec) than for biphasic shocks (75 ± 23 msec, P < 0.05). Conclusion: The decreased number of activation fronts and the longer delay following the shock for the earliest epicardial appearance of those activation fronts that do occur may be responsible for the increased defibrillation efficacy for biphasic shocks.     

Tobacco use among Japanese schoolchildren: results from preliminary study of Japan adolescent smoking survey (JASS)

Over the past two decades many studies have shown associationsbetween smoking and increased health problems. Smoking amongchildren is especially a major public health concern. Preventingyoung people from developing a smoking habit is an importantgoal for school health education. In Japan, it is difficult to collect accurate data regardingadolescent smoking behaviour, because in Japan smoking underthe age of 20 is prohibited by law. Therefore, a large surveyof smoking habits of young Japanese people was overdue. Numeroussurveys have been carried out since the late 1970s, but thesehave been limited in sample size or geographic area. The Japan Adolescent Smoking Survey (JASS) is probably the largestnumerical survey of smoking behaviour and opinions of schoolchildrenever carried out in Japan. Here the authors show the preliminaryresults of JASS. The goals of the JASS study are to standardize the method ofmeasurement in the smoking behaviour of young children. We believeit is now possible to compare national and international smokingrates of young people, and further, to develop and evaluateteaching methods about smoking for schoolchildren on the basisof this standardization. This report presents the tobacco use among schoolchildren inJapan.     

Disposition of Polaprezinc (Zinc l-Carnosine Complex) in Rat Gastrointestinal Tract and Effect of Cimetidine on its Adhesion to Gastric Tissues

The disposition of polaprezinc in the rat gastrointestinal tract was studied by a double tracer method using [¹⁴C]- and [⁶⁵Zn]polaprezinc. At 0·5 h after oral administration of [¹⁴C]-, [⁶⁵Zn]polaprezinc to rats, the ¹⁴C-radioactivity in the gastric contents was comparable with the ⁶⁵Zn-radioactivity. However, a significant difference was observed in the time course of changes in gastric contents between ¹⁴C- and ⁶⁵Zn-radioactivity over 1 h after administration, indicating that polaprezinc existed in complex form at 0·5 h after administration and was dissociated to l -carnosine and zinc in the gastrointestinal tract as a function of time. The adhesion of zinc to stomach mucosa after oral administration of polaprezinc to rats was significantly increased by treatment with cimetidine. These results suggest that the adhesion of zinc to gastric tissues is increased by inhibiting the dissociation of polaprezinc, and that H₂-receptor antagonists, such as cimetidine, may increase anti-ulcer effects of polaprezinc.     

>CASE REPORT: Eosinophilic colitis with high antibody titre against Ascaris suum

Eosinophilic gastroenteritis (EGE) is an inflammatory disease characterized by eosinophilic infiltration of the gastrointestinal tract accompanied by varying abdominal symptoms and usually by peripheral blood eosinophilia. Although the precise aetiology of EGE remains to be determined, contribution of allergic process to certain allergens, such as foods, drugs and parasites, has been repeatedly proposed as the pathogenesis of the disease. Here we report on a rare case of a woman who had extensive eosinophilic infiltration in the descending and rectal colon with a high titre of IgG antibody against Ascaris suum. The patient was successfully treated with prednisolone.     

Sevoflurane in paediatric anaesthesia: effects on respiration and circulation during induction and recovery

This study examined induction and recovery times and respiratory and cardiovascular changes during induction and recovery in paediatric patients undergoing anaesthesia under spontaneous respiration induced with sevoflurane (S group, n= 10) and halothane (H group, n= 9) at 2.4 MAC. FET/FI increased more rapidly, the incidence of breath holding and coughing was less and the recovery time was shorter in the S group compared with the H group. During induction with sevoflurane at 2.4 MAC, min vol/bodyweight decreased due to reduced tidal vol/bodyweight despite increased respiratory frequency, as with halothane at the same MAC. Slight decrease in blood pressure was observed during induction in the S group, while the circulatory depression was not observed during induction in the H group. These results suggest that sevoflurane is a suitable agent for induction under spontaneous respiration with higher concentrations in paediatric anaesthesia.     

Accuracy of stone-casts produced from selected addition-type silicone impressions

Abstract – The present study has shown that there is no correlation between the free curing contraction of three selected addition-type silicone impression materials and the effective contraction determined as the accuracy of stone dies produced in dental impressions of these materials. Depending on specific rheologic properties, the free curing contraction of an impression material can be partly compensated for by flow.     

Dose-dependent biphasic effects of phenobarbital on growth and differentiation of primary culture rat hepatocytes

The actions of phenobarbital, a liver tumour promoter, on growth and differentiation of primary culture normal rat hepatocytes change biphasically as a function of its concentration. At low concentrations of 0.5–2 mmol/L, phenobarbital enhances DNA synthesis of normal adult rat hepatocytes in the presence of epidermal growth factor (EGF) and/or dexamethasone. This is also true for normal suckling (1–2-week-old) rat hepatocytes, without added growth factor(s), in serum-free primary culture. Contrarily, phenobarbital at high concentrations (3–4 mmol/L) suppresses DNA synthesis of suckling rat hepatocytes. Furthermore, phenobarbital inhibits DNA synthesis of transforming growth factor-a-stimulated primary hepatocytes from normal adult rats in a dose-dependent manner within a concentration range of 3–6 mmol/L. When normal adult rat hepatocytes are led to undergo multiple proliferative cycles upon stimulation with hepatocyte growth factor (HGF) and EGF in the chemically defined hepatocyte growth medium (HGM), 3 mmol/L phenobarbital also remarkably suppresses DNA synthesis. Phenobarbital at 3 mmol/L effectively keeps these hepatocytes morphologically differentiated and accelerates restoration of the expression of markers characteristic of differentiated cells after the initial cellular growth phase. In addition, phenobarbital efficiently supports prolonged survival of the hepatocytes.     

Case report: Portal-systemic encephalopathy due to a congenital extrahepatic portosystemic shunt

We present a case of portal-systemic encephalopathy due to a congenital splenorenal shunt. A 69 year old woman was admitted to hospital because of recurrent episodes of disturbed consciousness. The present episode had begun 3 months prior to admission. Although the patient demonstrated mildly slurred speech, the remainder of her neurological examination was unremarkable. She showed no clinical signs of portal hypertension and her liver function, except for a serum hepaplastin test of 58% and an ICG retention rate of 28% at 15 min, was normal. Her serum ammonium level was 210 μg/dL. The venous phase of a superior mesenteric arteriogram revealed a splenorenal shunt and narrowing of the portal vein, which was 4 mm in diameter. The histological findings, demonstrated by a needle liver biopsy specimen, were consistent with mild fibrosis and lymphocytic infiltration. Following the diagnosis of a splenorenal shunt in the absence of liver cirrhosis, ligature of the shunt was performed with a splenectomy. The portal vein pressure after ligature of the shunt rose from 12.5 to 18.8 mmHg. This shunt was thought to be of congenital origin. The high preoperative serum ammonia concentration decreased to the normal range postoperatively and the serum hepaplastin test and ICG retention rate similarly improved postoperatively. A follow-up superior mesenteric arteriogram was performed during the venous phase, demonstrating resolution of the shunt and decreased portal vein narrowing. The patient has suffered no further episodes of disturbed consciousness postoperatively.     

Impact of sociodemographic and diabetes-related characteristics on depressive state among non-insulin-dependent diabetic patients

Abstract  One hundred and fifty-one non-insulin-dependent diabetic patients were assessed to detect sociodemographic, psychological and disease-related characteristics that were related to depressive state among diabetic patients. Depressive state in the patients was correlated with poor social support and low economic status, premorbid neurotic personality and the presence of complications, retinopathy in particular. However, depressive state did not correlate with age, gender, education, serum level of HbA_1C or duration of diabetes. The severity of the depressive state in diabetic patients may vary with the cultural background of the patient and/or the country in which he or she is living. In treating diabetic patients, doctors need to pay special attention to these factors.     

Relationship of angiographic finding with neovascular structure detected by immunohistochemical staining of α-smooth muscle actin in small hepatocellular carcinoma

To elucidate the relationship between angiographic features and histological findings, an immunohistological study of α-smooth muscle actin was performed in 106 patients with small hepatocellular carcinoma. Arterial dominance or portal blood paucity were found in 73 patients (68.9%) on digital subtraction angiography, 88 (83.0%) on computerized tomographic arterial portography and 87 (82.1%) on carbon dioxide-enhanced ultrasonography. Among 73 patients with hypervascularity on angiography, 57 (78.1%) had thick-walled, nuclei-rich and slender-shaped vessels (type II), eight (11, 0%) had thin-walled, nuclei-poor and oval-shaped vessels (type I) and the remaining eight had a mixed type of II and I. Conversely, among 33 patients without hypervascularity, five (15.2%) had a type II, 21 (63.6%) had a type I, five had a mixed type and two had no positive vessel. Tumour size, histological classification and amount of non-triadal vessels were also associated with the angiographic appearance of the tumours. Among varied aspects of the cancer including tumour size, tumour multiplicity, microscopic portal invasion, histological classification, amount of α-smooth muscle actin-positive vessels and shape of α-smooth muscle actin-positive vessels, multivariate logistic regression analysis demonstrated that the shape of α-smooth muscle actin-positive vessels was solely associated with angiographic hypervascularity independently (P < 0.0001). Although the existence of non-triadal vessels characterized hepatocellular carcinoma, angiographic hypervascularity was closely associated with the type II vessel. A morphological change of non-triadal vessel from type I to type II was considered to occur in an early stage of hepatocellular carcinoma.