Normocytic normochromic anemia due to automatic neuropathy in type 2 diabetic patients without severe nephropathy: a possible role of microangiopathy

We describe here four male patients with long-term and poorly controlled type 2 diabetes mellitus. They shared many common characteristic complications, such as severe autonomic neuropathy, proliferative retinopathy and normocytic normochromic anemia without progressive renal failure and macroangiopathy. They also showed normal levels of erythropoietin and reticulocyte, which was considered relatively low. The coefficient of variation of R–R, a useful method to estimate autonomic failure, showed markedly advanced autonomic neuropathy in all four patients. Coronary angiography did not reveal stenosis, anomaly or collateral vessels, but left ventriclography showed diffuse or partial hypokinesis. Massive proteinuria, high urinary levels of N-acetyl-β-d-glucosamidase (NAG) and β₂-microglobulin (β₂M) were detected, though creatinine clearance (Ccr) was not so deteriorated. Treatment with recombinant erythropoietin increased their hemoglobin and hematocrit levels. These common points have a possibility to be brought about by tubulointerstitial damage and microangiopathy may be involved in it.     

Cytotoxicity of Acetaldehyde‐Derived Advanced Glycation End‐Products (AA‐AGE) in Alcoholic‐Induced Neuronal Degeneration

Abstract : Background: The Maillard reaction that leads to the formation of advanced glycation end‐products (AGEs) plays an important role in the pathogenesis of angiopathy in diabetic patients, in aging and in neurodegenerative processes. We hypothesize that acetaldehyde (AA), one of the main metabolites of alcohol, may be involved in alcohol‐induced neurotoxicity in vivo by formation of AA‐derived AGEs (AA‐AGE) with brain proteins. Methods: AA‐AGE‐bovine serum albumin (BSA) and AA‐AGE‐rabbit serum albumin (RSA) were prepared as described previously. Antibody specific for AA‐AGE was isolated from rabbit antiserum by affinity chromatography. Primary cortical neuronal cell cultures were prepared as described previously. Results: Incubation of cortical neurons with AA‐AGE produced a dose‐dependent increase in neuronal cell‐death, and the neurotoxicity of AA‐AGE was neutralized by the addition of an anti‐AA‐AGE specific antibody, but not by anti‐N‐ethyllysine (NEL) antibody. The AA‐AGE epitope was detected in human brain of alcoholism. Conclusions: We propose that the structural epitope AA‐AGE is an important toxic moiety for neuronal cells in alcoholism.     

Vasopressin responsiveness of subclinical Cushing's syndrome due to ACTH-independent macronodular adrenocortical hyperplasia

OBJECTIVE: Vasopressin (AVP) is reported to be an important factor for regulating cortisol secretion in patients with Cushing's syndrome due to ACTH-independent macronodular adrenocortical hyperplasia (AIMAH). Recently, there have been several case reports of subclinical Cushing's syndrome due to AIMAH, in which the pathophysiological role of AVP has been unknown. The aim was to conduct an extensive investigation of AVP in the autonomous secretion of cortisol in subclinical Cushing's syndrome due to AIMAH. PATIENTS AND MEASUREMENTS: Five cases of AIMAH with subclinical Cushing's syndrome underwent prospective study including physical examination, imaging (MRI, CT and 131I-adosterol scintigraphy) and endocrinological evaluation that comprised basal plasma cortisol levels and urinary excretions of steroid metabolites, a dexamethasone suppression test and an AVP stimulation test. In case 1, left adrenalectomy was performed and the pathological diagnosis of AIMAH was established. An in vitro experiment using the cultured AIMAH adrenal cells was conducted to investigate cortisol secretion and expression of the V1-AVP receptor, mRNA by RT-PCR. RESULTS: All five cases were discovered incidentally to have bilateral adrenal nodules. Imaging by MRI and CT revealed large multinodular lesions in both adrenal glands, which showed positive uptake on 131I-adosterol scintigraphy. Although the basal values of plasma cortisol and urinary excretions of steroid metabolites were within normal limits, autonomous secretion of cortisol was assumed to occur because of lack of suppression during dexamethasone suppression. The five patients had no overt signs of Cushing's syndrome, and they were therefore diagnosed with subclinical Cushing's syndrome due to AIMAH. In all five patients, AVP stimulated cortisol secretion in vivo, whereas desmopressin acetate failed to affect cortisol secretion. In case 1, AVP stimulated cortisol secretion from cultured AIMAH adrenal cells, but this secretion had no relationship with cAMP production. In addition, over-expression of V1-AVP receptor mRNA in AIMAH tissue was determined by RT-PCR. CONCLUSION: Patients with subclinical Cushing's syndrome due to AIMAH commonly exhibit cortisol responsiveness to AVP, and this is probably mediated through activation of overexpressed V1-AVP receptors.     

Epidemiological characteristics and virulence factor of verotoxin-producing Eschericia coli O121:H19 isolated in Akita Prefecture in July 1997

Epidemiological characteristics and virulence factors of VTEC O121:H19 strains isolated in July 1997 from a 15 year old female and a 20 year old male patient suffering from bloody diarrhea and severe abdominal pain were examined. The 2 VTEC O121:H19 isolates showed identical antibiotic susceptibility patterns, biochemical characteristics and plasmid profile while slight differences were observed in their Xba I and Not I PFGE patterns, suggesting that closely related 2 VTEC O121:H19 strains evoked the sporadic infectious cases in July 1997. The 2 VTEC O121:H19 isolates, as well as VTEC O157:H7, possessed eaeA gene and a ca. 60 MDa plasmid which hybridised with CVD 419 probe and produced enterohemolysin. In addition, the VTEC O121:H19 isolates produced almost the same amount of VT-2 in vitro as VTEC O157:H7 did. These results suggested that VTEC O121:H19 possesed the virulence factor comparable to that of VTEC O157:H7. Incidence, molecular epidemiology and infectious source of VTEC O121:H19 in this country have not been sufficiently understood. Antiserum for E. coli serogroup O121 should be manufactured to clarify the epidemiology of the highly virulent VTEC strain.     

Comparison of the ion channel characteristics of proapoptotic BAX and antiapoptotic BCL-2

The BCL-2 family of proteins is composed of both pro- and antiapoptotic regulators, although its most critical biochemical functions remain uncertain. The structural similarity between the BCL-X_L monomer and several ion-pore-forming bacterial toxins has prompted electrophysiologic studies. Both BAX and BCL-2 insert into KCl-loaded vesicles in a pH-dependent fashion and demonstrate macroscopic ion efflux. Release is maximum at ≈pH 4.0 for both proteins; however, BAX demonstrates a broader pH range of activity. Both purified proteins also insert into planar lipid bilayers at pH 4.0. Single-channel recordings revealed a minimal channel conductance for BAX of 22 pS that evolved to channel currents with at least three subconductance levels. The final, apparently stable BAX channel had a conductance of 0.731 nS at pH 4.0 that changed to 0.329 nS when shifted to pH 7.0 but remained mildly Cl⁻ selective and predominantly open. When BAX-incorporated lipid vesicles were fused to planar lipid bilayers at pH 7.0, a Cl⁻-selective (P_K/P_Cl = 0.3) 1.5-nS channel displaying mild inward rectification was noted. In contrast, BCL-2 formed mildly K⁺-selective (P_K/P_Cl = 3.9) channels with a most prominent initial conductance of 80 pS that increased to 1.90 nS. Fusion of BCL-2-incorporated lipid vesicles into planar bilayers at pH 7.0 also revealed mild K⁺ selectivity (P_K/P_Cl = 2.4) with a maximum conductance of 1.08 nS. BAX and BCL-2 each form channels in artificial membranes that have distinct characteristics including ion selectivity, conductance, voltage dependence, and rectification. Thus, one role of these molecules may include pore activity at selected membrane sites.     

Overexpression of p53 protein and histologic grades of dysplasia in colorectal adenomas

PURPOSE: To clarify the relation between tumor-suppressor gene p53 expression and histologic grades of dysplasia in colorectal adenomas, we performed immunohistochemical analysis in a series of 59 colorectal polyps and 40 advanced carcinomas. METHODS: Adenomatous polyps were stained by hematoxylin and eosin and classified into mild, moderate, and severe dysplasia (intramucosal carcinoma), according to the World Health Organization's classification. RESULTS: p53 was positive in 7.1 percent (2/28) of mild, 29.4 percent (5/17) of moderate, and 62.5 percent (5/8) of severe dysplasia. In submucosal and advanced carcinomas, positivity rates were 75 percent (3/4) and 47.5 percent (19/40), respectively. Different staining patterns were found, according to grades of dysplasia. In the adenomas with mild or moderate dysplasia, a few focal crypts showed localized p53-positive staining. Adenomas with severe dysplasia had two different staining types. One was a focal staining type as shown in mild or moderate dysplasia; the other was a diffuse staining type, in which glands with mild or moderate dysplasia, surrounding severe dysplasia area, were also stained. Submucosal and advanced carcinomas showed a strong positive staining in cancer cells only. CONCLUSIONS: Overexpression of p53 protein in adenomas with mild or moderate dysplasia and existence of two types of expression in adenomas with severe dysplasia were observed. These facts suggested the possible existence of different pathways in the adenoma to carcinoma progression.     

Serum levels of healthy adult humans and changes of IgG subclass levels between infected and convalescent phase in respiratory infections

We measured serum levels of IgG subclasses in 100 healthy adult humans and 64 patients with respiratory infections by utilizing the enzyme linked immunosorbent assay (ELISA). The patients were composed of 18 patients with acute bacterial pneumonia and bacterial infection of 9 patients with pulmonary emphysema, 27 patients with chronic bronchitis and 10 patients with bronchiectasis. In healthy adults, serum levels of IgG1 subclass decreased in proportion of age increase. Serum levels of IgG2 rose after 30 years of age. Serum levels of IgG3 and IgG4 showed no remarkable changes by age. In patients with respiratory infectious disease, serum levels of IgG1, IgG2 and IgG4 decreased significantly but IgG3 increased significantly. We also measured serum levels of IgG subclasses in 10 patients with acute bacterial pneumonia and bacterial infection of 5 patients with pulmonary emphysema, 12 patients with chronic bronchitis and 4 patients with bronchiectasis at both infected and convalescent phases. The serum levels of IgG2 in patients with pneumonia and pulmonary emphysema at convalescent phase were significantly lower than those in the patients of infected phase. Other subclasses showed no significant change. We summarized that IgG2 was consumed at the infected phase by protecting against bacterial infections. IgG2 probably has an important role of protecting against bacterial respiratory infections among all IgG subclasses.     

The predictive role of infiltrative growth pattern in early pharyngeal cancers

Conclusion: The infiltrative growth pattern may predict tumor depth and lymph node metastasis. INF-a seems to fall into a low-risk category, and no additional treatment may be required immediately. Objectives: Tumor depth is a predictor of lymph node metastasis in early pharyngeal cancers. An infiltrative growth pattern is also a prognostic factor in other cancers. This study aimed to elucidate the predictive role of infiltrative growth pattern in early pharyngeal cancers. Methods: Thirty-eight lesions from 37 patients who had undergone trans-oral resection of pharyngeal cancers were included. According to the Japanese Classification of Esophageal Cancer, infiltrative growth pattern was classified into three groups; INF-a, INF-b, and INF-c. The correlation between infiltrative growth pattern and tumor depth, cervical lymph node metastasis was analyzed. Results: Of the 38 lesions, 25 were INF-a, nine were INF-b, and four were INF-c lesions. Lymph node metastasis was observed in three INF-b and one INF-c lesions. In contrast, no INF-a had lymph node metastasis. All INF-a lesions showed shallow invasion of the sub-epithelium; INF-b and INF-c lesions had significantly greater depth than INF-a.