ATP sparing effect of isoflurane during ischaemia and reperfusion of the canine heart

Sustained dysfunction of myocardial contractility after shortperiods of coronary artery occlusion and reperfusion has beentermed "stunned myocardium". Isoflurane may improve the recoveryof regional myocardial contractility in stunned myocardium.The purpose of the present study was to determine if isofluraneprevents depletion of high energy phosphates after myocardialischaemia-reperfusion and if the reduction in cardiac work duringisoflurane anaesthesia contributes to the preservation of highenergy phosphate metabolism in an acute canine model. Mongreldogs were allocated to one of three groups: controls, anaesthetizedwith urethane and chloralose; ISO group, isoflurane administeredbefore ischaemia; and ISOc group, heart rate and mean arterialpressure controlled to approximately match baseline values.The left anterior descending (LAD) coronary artery was occludedfor 15 min and then reperfused for 60 min during 1.5% end-tidalisoflurane anaesthesia. Full thickness samples of myocardiumwere obtained from the reperfused area (supplied by the LAD)and the non-ischaemic area (supplied by the left circumflexcoronary artery). The concentrations of adenosine monophosphate(AMP), adenosine diphosphate (ADP), adenosine triphosphate (ATP),creatine phosphate (CP) and lactate in the endocardial portionof the myocardium were measured. Arterial pressure, aortic flowin the ascending aorta and rate-pressure product decreased significantlyafter isoflurane. Although the concentration of ATP of the reperfusedarea in the control group showed a significant reduction 60mm after reperfusion, the ISO and ISOc groups had significantlygreater concentrations. Isoflurane anaesthesia maintained myocardialhigh energy phosphate metabolism in reperfused myocardium. Weconclude that the reduction in cardiac work played only a minorrole in the ATP-sparing effect of isoflurane. (Br. J. Anaesth.1995; 74: 563–568)     

Atrial Electrograms and Activation Sequences in the Transition Between Atrial Fibrillation and Atrial Flutter

Transition Between Atrial Fibrillation and Flutter. Introduction: The eletrophysiologic mechanism of atrial fibrillation (AF) has a wide spectrum, and it seems that some atrial regions are essential for the occurrence of a particular type of AF. We focused on one type of AF: AF associated with typical atrial flutter (AFI), which was right atrial (RA) arrhythmia, and sought to investigate intra-atrial electrograms and activation sequences in the transition between AF and AFL.
Methods and Results: Intra-atrial electrograms and activation sequences in the R.A free wall and the septum were evaluated in the transition between AF and AFL in seven patients without organic heart disease (all men; mean age 57 ± 11 years). In five episodes of the conversion of AFL into AF, the AFL cycle length was shortened (from 211 ± 6 msec in stable AFL to 190 ± 15 msec before the conversion, P, 0.001). Interruption of the AFL wavefront and an abrupt activation sequential change induced by a premature atrial impulse resulted in fractionation and disorganization of the septal electrograms. During sustained AF, septal electrograms were persistently fractionated with disorganized activation sequences. However, the RA free-wall electrograms were organized, and the activation sequence was predominantly craniocaudal rather than caudocranial throughout AF. In 12 episodes of the conversion of AF into AFL, the AF cycle length measured in the RA free wall increased (from 165 ± 26 msec at the onset of AF to 180 ± 24 msec before the conversion, P, 0.001). AFL resumed when fractionated septal electrograms were separated and organized to the caudocranial direction, despite the RA free-wall electrograms remaining discrete and sharp with an isoelectric line.
Conclusion: Changes of the electrogram and activation sequence in the atrial septum played an important role in the transition between AF and AFL.     

IgG4-related disease of the thyroid glands

Recent reports on Hashimoto's thyroiditis (HT) with increased numbers of IgG4-positive plasma cells suggest that this type of HT may have a close relationship to IgG4-related disease (IgG4-RD). This unique subgroup of HT is termed as IgG4 thyroiditis and reveals distinct clinical, serological, and sonographic features from the non-IgG4 thyroiditis group. On the basis of immunostaining for IgG4, HT was divided into an IgG4 thyroiditis group and a non-IgG4 thyroiditis group. Clinically, IgG4 thyroiditis was associated with younger age group, lower female-male ratio, higher levels of thyroid autoantibodies, diffuse low echogenicity, more rapid progress requiring surgical treatment and more subclinical hypothyroidism. Serum IgG4 concentrations elevated in IgG4 thyroiditis and decreased significantly after a thyroidectomy. Histopathologically, IgG4 thyroiditis showed a higher grade of stromal fibrosis, lymphoplasmacytic infiltration, and follicular cell degeneration than non-IgG4 thyroiditis. IgG4 thyroiditis may represent IgG4-RD of thyroid gland, because it shares common histopathological characteristics with IgG4-RD in other organs. The identification of IgG4-RD of the thyroid gland opens new insights not only for patient's treatment with HT but also for the development of new therapeutic approaches for this rapidly progressive destructive subtype of HT. This article mainly focuses on reviewing the unique histopathological, clinical, and serological features of IgG4 thyroiditis group of HT. The etiology and genetic changes of HT are also discussed.     

Low prevalence of anti-hepatitis C virus antibodies in female hemodialysis patients without blood transfusion: A multicenter analysis

To investigate whether nosocomial infection with hepatitis C virus (HCV) in chronic hemodialysis patients is related primarily to hemodialysis procedures, a multicenter analysis was carried out on 2,132 chronic hemodialysis patients (male: 1,274, female: 858) from 23 dialysis units using a second-generation anti-HCV antibody assay. The prevalence of anti-HCV antibodies in patients with blood transfusion (29.9%) was significantly higher (P < .0001) than in those without blood transfusion (7.6%). Although the prevalence of anti-HCV antibodies increased with the length of hemodialysis in males without blood transfusion, it did not increase even after long-term hemodialysis (more than 5 years) in females without blood transfusion, who exhibited a rate (1.9%) similar to that of healthy blood donors in Japan. There was a significant correlation between the presence of anti-HCV antibodies and anti-HBs antibody in males without blood transfusion. In anti-HBs antibody-negative male patients without blood transfusion, the prevalence of anti-HCV antibodies was significantly lower compared with anti-HBs antibody-positive male patients without blood transfusion. There was marked difference in the prevalence rate in patients without blood transfusion among dialysis units, and there was no correlation between the prevalence and the mean period of dialysis of each dialysis unit. Although nosocomial infection with HCV appears to be related to the hemodialysis environment, the low prevalence of anti-HCV antibodies in females suggests that dialysis procedures per se may not present the risk of hepatitis C virus infection. © 1996 Wiley-Liss, Inc.     

A Case of Neonatal McCune-Albright Syndrome with Cushing Syndrome and Hyperthyroidism

ABSTRACT. We describe a female newborn infant with McCune-Albright syndrome. In addition to the cutaneous pigmentation, she had apparent manifestations of hyperthyroidism and Cushing syndrome since birth. X-ray examinations showed many scattered lucencies in multiple bones. Endocrinological findings were as follows: serum T4 276 nmol/l; free T4 125 pmol/l; TSH <1 mU/l; serum cortisol >2210 nmol/l; plasma ACTH < 10 pg/ml; urinary free cortisol 865 nmol/day; estradiol 0.36 nmol/l. Regardless of treatment with antithyroid drugs and an inhibitor of 3β-hydroxysteroid dehydrogenase, the patient died of cardiac failure at the age of 4 months. Autopsy findings included a follicle cyst in the right ovary and multinodular hyperplasia in the thyroid and both adrenals. To our knowledge such a severe neonatal form of McCune-Albright syndrome has not been described in the literature.