Beta-thalassemia in Iran: a high incidence of the nonsense codon 39 mutation on the island of Queshm

Optic disc blood flow velocity was measured in healthy patients, those with primary open angle glaucoma (POAG), and patients with normal pressure glaucoma (NPG). The velocity of the red blood cells (RBCs) in the capillaries of the optic nerve head (ONH) has been measured with a laser Doppler velocimeter (LDV), and blood viscosity has been evaluated notably by determining the aggregability of the RBCs with an erythroaggregameter. Our results in POAG patients and NPG patients showed that their optic nerve blood flow velocity was reduced and that the aggregability of the RBCs was increased. The hyperaggregability of the erythrocytes is responsible for the increase of the local viscosity in the papillary capillary network. These haemodynamic modifications observed in patients with glaucoma support the hypothesis of a vasogenic mechanism that could impair the optic nerve in glaucoma patients.     

Nanobacteria: an alternative mechanism for pathogenic intra- and extracellular calcification and stone formation

Calcium phosphate is deposited in many diseases, but formation mechanisms remain speculative. Nanobacteria are the smallest cell-walled bacteria, only recently discovered in human and cow blood and commercial cell culture serum. In this study, we identified with energy-dispersive x-ray microanalysis and chemical analysis that all growth phases of nanobacteria produce biogenic apatite on their cell envelope. Fourier transform IR spectroscopy revealed the mineral as carbonate apatite. The biomineralization in cell culture media resulted in biofilms and mineral aggregates closely resembling those found in tissue calcification and kidney stones. In nanobacteria-infected fibroblasts, electron microscopy revealed intra- and extracellular acicular crystal deposits, stainable with von Kossa staining and resembling calcospherules found in pathological calcification. Previous models for stone formation have led to an hypothesis that elevated pH due to urease and/or alkaline phosphatase activity is a lithogenic factor. Our results indicate that carbonate apatite can be formed without these factors at pH 7.4, at physiological phosphate and calcium concentrations. Nanobacteria can produce apatite in media mimicking tissue fluids and glomerular filtrate and provide a unique model for in vitro studies on calcification.     

IgE, IgA, and IgG responses to common yeasts in atopic patients

To assess the incidence of HIV infection and risk factors associated with HIV seroconversion among patients attending clinics for sexually transmitted diseases (STD), medical record reviews were conducted in 12 clinics in 7 U.S. cities. The records of all patients who initially tested negative for HIV from 1991 through 1996 and who received at least one additional HIV test during the study period were reviewed. In each of 7 cities, 5 to 112 patients seroconverted. Of the 286 seroconverters identified in total, 53% (152 of 286) were heterosexual men and 28% (81 of 286) were women. HIV incidence rates among men who have sex with men (MSM) ranged by city from 0.81 to 7.0 new infections/100 person-years. Rates among heterosexual men and women ranged from 0.018 to 1.2 infections/100 person-years. Multivariate analyses showed that drug use was associated with HIV seroconversion only among heterosexuals. Most new HIV infections in these clinics are being transmitted heterosexually and are associated with drug use. Nevertheless, MSM, particularly young MSM, are at greatest risk for HIV in this population: 1 of 47 seroconvert/year. The effective use of targeted prevention efforts depends upon the continued ability to monitor the incidence of HIV infection.     

Molecular and cell biological aspects of neuroendocrine tumors of the gastroenteropancreatic system

Neurons and neuroendocrine cells share a variety of common characteristics. Cell and molecular biological studies in recent years have improved our understanding of physiological and pathophysiological processes such as cellular growth, adhesion, and secretion of neuroendocrine cells. Here we review current findings from the area of basic research and from current clinical research relevant to improving the diagnosis and therapy of neuroendocrine tumors of the gastroenteropancreatic system.     

Stromelysin 3 is overexpressed in human pancreatic carcinoma and regulated by retinoic acid in pancreatic carcinoma cell lines

OBJECTIVE: To develop a simple prognostic index for anticipating more precisely the early clinical course of primary superficial bladder cancer. PATIENTS AND METHODS: The prognostic value of patient and tumour characteristics was examined in 333 patients with primary Ta or T1 bladder cancer who participated in a multicentre prospective study already completed. Primary tumour multiplicity, a diameter of > 3 cm, stage T1, and grade 2 or 3 were independent predictors of earlier recurrence in a multivariate analysis. A simplified prognostic index consisted of the number of adverse tumour characteristics (ATCs) initially present. RESULTS: After a median follow-up of 35.3 months, the 60 patients free of ATCs (19%) had a recurrence-free probability at 12 and 24 months of 86% and 69%, respectively, and none experienced progression. Recurrence outcomes deteriorated consistently as the number of ATCs increased among the other three groups. In patients with 3-4 ATCs, the 12- and 24-month recurrence-free probability was as low as 30% and 19%, and recurrence and tumour rates were about 2.6 times higher than in patients free of ATCs; 7% of these patients experienced progression within 35 months of follow-up. CONCLUSION: A prognostic index based on the number of ATCs (primary tumour multiplicity, diameter > 3 cm, stage T1, and grade 2 or 3) is a strong indicator of the clinical course of superficial bladder cancer within 3 years of the first endoscopic resection. This proposal is suggested for discussion and for validation in future studies but if confirmed, this simple prognostic index may greatly help to identify indicators for adjuvant intravesical therapy and to determine the optimal periodicity of control cystoscopy regimens.     

Retinoic acid receptor gamma1 expression determines retinoid sensitivity in pancreatic carcinoma cells

A highly enriched spindle pole preparation was prepared from budding yeast and fractionated by SDS gel electrophoresis. Forty-five of the gel bands that appeared enriched in this fraction were analyzed by high-mass accuracy matrix-assisted laser desorption/ ionization (MALDI) peptide mass mapping combined with sequence database searching. This identified twelve of the known spindle pole components and an additional eleven gene products that had not previously been localized to the spindle pole. Immunoelectron microscopy localized eight of these components to different parts of the spindle. One of the gene products, Ndc80p, shows homology to human HEC protein (Chen, Y., D.J. Riley, P-L. Chen, and W-H. Lee. 1997. Mol. Cell Biol. 17:6049-6056) and temperature-sensitive mutants show defects in chromosome segregation. This is the first report of the identification of the components of a large cellular organelle by MALDI peptide mapping alone.     

Outcome of hepatitis C patients with and without hepatocellular carcinoma undergoing liver transplant

OBJECTIVE: Hepatitis C virus (HCV) infection is associated with development of hepatocellular carcinoma (HCC). The aim of this study was to examine clinical characteristics and outcome of patients with HCV with or without HCC undergoing liver transplant. METHODS: We reviewed the charts of all 55 patients transplanted between November 1990 and December 1996 for HCV cirrhosis with HCC and compared them with a control group of HCV patients without HCC. Patients with a history of alcohol abuse or HBsAg positivity were excluded. There were 37 men and 18 women, with a mean age of 57.6 yr (range, 19-70 yr) in the HCC group. RESULTS: There was no significant difference between the HCC and nonHCC groups regarding Child's class or United Network for Organ Sharing (UNOS) status at the time of transplant. Twenty-six (45%) patients were diagnosed or suspected of having HCC before transplant. Twenty-five patients (45.5%) had a single focus of HCC. Fourteen percent (seven of 50) of the patients with HCC had been treated with interferon, whereas 12% (six of 52) of patients in the nonHCC group had received interferon. Duration of interferon therapy ranged from 1 to 9 months. All interferon treatment occurred within 5 yr of transplant. A history of intravenous drug use or transfusion was identified in 37 (67%) of HCC patients. Thirty-two patients (58%) without HCC had a parenteral exposure. There was no significant difference in patient or graft survival rates between the patients with and without HCC. CONCLUSION: Approximately one-half of HCC was not detected before liver transplant. There was no significant difference in the mode of transmission, clinical status at the time of transplant, or outcome between the HCV patients with and without HCC.