Effects of verapamil on the cellular accumulation of daunorubicin in blast cells and on the chemosensitivity of leukaemic blast progenitors in acute myelogenous leukaemia

Verapamil, a calcium channel blocker, was studied for its effects on the cellular daunorubicin (DNR) accumulation in blast cells and on the sensitivity of the blast progenitors to DNR in 30 acute myelogenous leukaemia (AML) patients. Using flow cytometry, verapamil was shown to increase the accumulation of DNR in blast cells. The effect was more prominent in the patients who showed poorer response to chemotherapy including DNR. The per cent increases of DNR content by verapamil were 6.4 +/- 6.3% and 19.5 +/- 23.1% in the 16 responders and the 14 nonresponders, respectively (P less than 0.05). The data suggest the presence of enhanced efflux of DNR in nonresponders. Marked variation in the effects of verapamil among nonresponders suggests the heterogeneity of the mechanisms of drug resistance involved. Verapamil also enhanced the sensitivity of blast progenitors to DNR. The degree of increase of cellular DNR accumulation by verapamil correlated with the degree of increase in chemosensitivity of blast progenitors (nonresponders, P less than 0.005; responders, P less than 0.05). We conclude that enhanced efflux of DNR in blast progenitors may be related to remission induction failure in at least some of resistant AML patients.     

Tissue-specific overexpression of lipoprotein lipase causes tissue-specific insulin resistance

Insulin resistance in skeletal muscle and liver may play a primary role in the development of type 2 diabetes mellitus, and the mechanism by which insulin resistance occurs may be related to alterations in fat metabolism. Transgenic mice with muscle- and liver-specific overexpression of lipoprotein lipase were studied during a 2-h hyperinsulinemic-euglycemic clamp to determine the effect of tissue-specific increase in fat on insulin action and signaling. Muscle-lipoprotein lipase mice had a 3-fold increase in muscle triglyceride content and were insulin resistant because of decreases in insulin-stimulated glucose uptake in skeletal muscle and insulin activation of insulin receptor substrate-1-associated phosphatidylinositol 3-kinase activity. In contrast, liver-lipoprotein lipase mice had a 2-fold increase in liver triglyceride content and were insulin resistant because of impaired ability of insulin to suppress endogenous glucose production associated with defects in insulin activation of insulin receptor substrate-2-associated phosphatidylinositol 3-kinase activity. These defects in insulin action and signaling were associated with increases in intracellular fatty acid-derived metabolites (i.e., diacylglycerol, fatty acyl CoA, ceramides). Our findings suggest a direct and causative relationship between the accumulation of intracellular fatty acid-derived metabolites and insulin resistance mediated via alterations in the insulin signaling pathway, independent of circulating adipocyte-derived hormones.     

Influenza A H1N1 pdm09‐associated myocarditis during zanamivir therapy

A 9‐year‐old girl developed influenza A H1N1 pdm09‐associated myocarditis and pericarditis 2 days after starting zanamivir therapy. The virus was detected in the respiratory tract but not in the serum or pericardial effusion. The virus sampled from the respiratory tract had normal susceptibility to neuraminidase inhibitors. Although no differences in interferon‐γ, interleukin (IL)‐1β, and tumor necrosis factor‐α were observed between the plasma and pericardial effusion, some inflammatory cytokines or chemokines (IL‐6 and IL‐8) and vascular endothelial growth factor were remarkably elevated in the pericardial effusion compared with the plasma. This suggested that the influenza virus, after infecting the respiratory tract, affected the myocardium, causing myocarditis to gradually develop, which might have been followed by an autoreactive pericarditis causing increased pericardial effusion. Therefore, influenza‐associated myocarditis should be considered when influenza patients have respiratory and cardiac involvement, even during treatment with a neuraminidase inhibitor.     

Quantitative analysis of K-ras gene mutation in pancreatic tissue obtained by endoscopic ultrasonography-guided fine needle aspiration: clinical utility for diagnosis of pancreatic tumor

OBJECTIVES: Endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) has become established in the diagnosis of pancreatic cancer. The combination of pathological diagnosis and analysis for mutant K-ras gene was investigated to improve the accuracy of diagnosis. METHODS: EUS-FNA was performed in 34 patients with pancreatic masses (26 adenocarcinomas and eight chronic pancreatitis). Mutant ras gene was analyzed semiquantitatively in the specimens obtained by EUS-FNA as well as in pancreatic juice obtained by ERCP. RESULTS: Mutant gene was detected at high amounts (more than 2% of total ras genes) in 20 of 26 (77%) specimens of EUS-FNA and in 12 of 19 (63%) of pancreatic juice in cases with pancreatic carcinoma. Cytological diagnosis of malignancy by EUS-FNA was found in 16 of 26 (62%) patients with pancreatic cancer. Accurate diagnosis of the carcinoma was 21 of 26 (81%) by combined cytology and molecular method of EUS-FNA, and increased to 23 of 26 (88%) by adding molecular analysis of pancreatic juice. In contrast, mutant gene was absent or low level despite suspicious cytology in patients with benign pancreatic lesion. CONCLUSION: Quantitative analysis of mutant ras gene supplemented conventional cytology of EUS-FNA and ERCP. Detection of mutation at high amounts may represent pancreatic cancer, whereas its absence increased the possibility of benign lesion.     

Supplementation with tetrahydrobiopterin prevents the cardiovascular effects of angiotensin II-induced oxidative and nitrosative stress

OBJECTIVE: The pteridine cofactor tetrahydrobiopterin (BH4) has emerged as a critical determinant of endothelial nitric oxide synthase (eNOS) activity. When BH4 availability is limited, eNOS does not produce nitric oxide (NO) but instead generates superoxide. BH4 may reverse endothelial dysfunction due to cardiovascular disease, including atherosclerosis, coronary artery disease and hypertension. In this study, the influence of BH4 on cardiovascular parameters and the production of free radicals following angiotensin II (Ang II) infusion was assessed. METHODS: BH4 (20 mg/kg per day in drinking water) was administered with Ang II (300 ng/kg per min subcutaneously, osmotic pump) for 7 days in Sprague-Dawley rats. In addition, BH4 was also given in vehicle-infused rats. RESULTS: Treatment with BH4 significantly prevented some of the effects of Ang II, such as impaired vascular responses to acetylcholine, hypertension and increases in heart weight index values. Treatment with BH4 also significantly reduced Ang II-induced increases in inducible NO synthase expression, nitrotyrosine immunostaining, NO production and superoxide anion formation in rats. CONCLUSION: These results indicate that BH4 might prevent the development of hypertension and myocardial hypertrophy, as well as the Ang II-induced production of superoxide and NO, thereby reducing the production of peroxynitrite. Therefore, BH4 may protect against the cardiovascular manifestations of oxidative and nitrosative stress in this experimental model of Ang II-mediated hypertension.     

Effect of post-transplant double filtration plasmapheresis on recurrent focal and segmental glomerulosclerosis in renal transplant recipients

In the present study, we reviewed the effect of post-transplant double filtration plasmapheresis (DFPP) on recurrent focal segmental glomerulosclerosis (FSGS) in the transplanted kidney allograft. Sixteen patients with post-transplant recurrent FSGS were enrolled in this study. Out of 16 patients with recurrent FSGS after transplantation, five did not receive DFPP and lost their grafts, while 11 did receive DFPP and four of these patients lost their grafts. Seven patients were able to maintain normal renal function for an average observation period of 57.1 +/- 40.7 months (range 7-125 months). In five patients who had a significant reduction in urinary protein after DFPP, the urinary protein level decreased from 26.60 +/- 23.05 g/day (range 3.34-62.6 g/day) to 2.95 +/- 3.42 g/day (range 0.02-8.64 g/day) and renal function was maintained. The beneficial effects of DFPP on graft outcome were more likely to occur if the patients experienced a marked drop in urinary excretion. Thus, post-transplant DFPP appears to be effective for reducing urinary protein levels and improving long-term graft survival. With the small numbers in this trial, however, none of the findings were statistically significant. We recommend the use of post-transplant DFPP to prevent the progression of recurrent FSGS.     

Perfectionism underlying psychological background correlated with the symptoms of functional dyspepsia

BACKGROUNDS: Early satiety, bloating, and postprandial distress are common symptoms in patients with functional dyspepsia (FD) and anorexia nervosa (AN). Perfectionism is known to be associated with AN, accompanied by abnormal eating behavior. We analyzed perfectionism in FD as compared with that in AN, and investigated the correlation of perfectionism with abdominal symptoms. METHODS: The study group comprised 168 patients with FD according to the Rome II criteria (65% females, mean age 47.7 years) and 101 with AN according to the DSM-IV criteria (100% females, mean age 23 years). As control, 130 healthy subjects (81% females, mean age 26.2 years) were studied. Frost's Multidimensional Perfectionism Scale (FMPS) was used to evaluate perfectionism. Abdominal symptoms were evaluated on the Gastrointestinal Symptoms Rating Scale (GSRS). RESULTS: All subscale scores except for organization were significantly higher in patients with AN than in controls. The parental criticism (PC) score in patients with FD was also significantly higher than that in controls, but lower than that in patients with AN. PC was significantly correlated with the total GSRS, particularly indigestion scores of FD patients (P = 0.0476 and P = 0.0294). CONCLUSIONS: Perfectionism such as PC underlying the psychological background of FD patients may be correlated with their abdominal symptoms.     

Coronary sinus pacing initiates counterclockwise atrial flutter while pacing from the low lateral right atrium initiates clockwise atrial flutter: Analysis of episodes of direct initiation of atrial flutter

Introduction: Rapid atrial pacing in sinus rhythm may directly induce atrial flutter without provoking intervening atrial fibrillation, or initiate atrial flutter indirectly, by a conversion from an episode of transient atrial fibrillation provoked by rapid atrial pacing. The present study was performed to examine whether or not the direct induction of clockwise or counterclockwise atrial flutter was pacing-site (right or left atrium) dependent. Methods and Results: We analyzed the mode of direct induction of atrial flutter by rapid atrial pacing. In 46 patients with a history of atrial flutter, rapid atrial pacing with 3 to 20 stimuli (cycle LENGTH = 500 − 170 ms) was performed in sinus rhythm to induce atrial flutter from 3 atrial sites, including the high right atrium, the low lateral right atrium, and the proximal coronary sinus, while recording multiple intracardiac electrograms of the atria. Direct induction of atrial flutter by rapid atrial pacing was a rare phenomenon and was documented only 22 times in 15 patients: 3, 11, and 8 times during stimulation, respectively, from the high right atrium, low lateral right atrium, and the proximal coronary sinus. Counterclockwise atrial flutter (12 times) was more frequently induced with stimulation from the proximal coronary sinus than from the low lateral right atrium (8 vs 1, P = .0001); clockwise atrial flutter (10 times) was induced exclusively from the low lateral right atrium (P = .0001 for low lateral right atrium vs proximal coronary sinus, P = .011 for low lateral right atrium vs high right atrium). Conclusions: Direct induction of either counterclockwise or clockwise atrial flutter was definitively pacing-site dependent; low lateral right atrial pacing induced clockwise, while proximal coronary sinus pacing induced counterclockwise atrial flutter. Anatomic correlation between the flutter circuit and the atrial pacing site may play an important role in the inducibility of counterclockwise or clockwise atrial flutter.     

Chronic hepatitis C associated with anti-liver/kidney microsome-1 antibody is not a subgroup of autoimmune hepatitis

To determine whether “autoimmune hepatitis type IIb” should be categorized as a subgroup of autoimmune hepatitis, we conducted a clinicopathological study of 25 adult Japanese patients who were positive for anti-liver/kidney microsome-1 (anti-LKM-1) antibody and infected with the hepatitis C virus (HCV). Anti-LKM-1 was determined by indirect immunofluo-rescence and by the double immunodiffusion assays we have developed. Twenty-two patients did not present any unusual symptoms or any associated diseases during the course of their chronic HCV infection. The spectrum of HCV genotypes of these patients did not significantly differ from that of anti-LKM-1-negative Japanese patients with chronic hepatitis C. Histological examination of liver biopsy specimens showed the usual characteristics of chronic hepatitis C and lack of characteristics of autoimmune hepatitis type I. No disease-specific HLA haplotypes were noted, and HLA-DR4, which is detectable in 88.7% of Japanese patients with autoimmune hepatitis type I, was detected in only 50.0% of our group, the same rate as the background frequency. Prednisolone was effective in none of the six patients treated, but interferon was effective in six of ten treated patients (60%). From these results, we conclude that “autoimmune hepatitis type IIb” should not be categorized as autoimmune hepatitis, and that this subgroup is essentially chronic hepatitis C in which an autoantibody has been produced during the course of chronic HCV infection.