Molecular basis of the heterogeneity of expression of glycosyl phosphatidylinositol anchored proteins in paroxysmal nocturnal hemoglobinuria

The purpose of these studies was to determine the molecular basis of the phenotypic mosaicism that is a defining feature of paroxysmal nocturnal hemoglobinuria (PNH). Analysis of T cell clones from a female patient revealed four distinct phenotypes based on surface expression of glycosyl phosphatidylinositol-anchored proteins (GPI-AP). When PIG-A (the gene that is mutant in PNH) from these clones was analyzed, four discrete somatic mutations were identified. Analysis of X chromosomal inactivation among the abnormal T cell clones was consistent with polyclonality. Together, these studies demonstrate that the phenotypic mosaicism that is characteristic of PNH is a consequence of genotypic mosaicism and that, at least in this case, PNH is a polyclonal rather than a monoclonal disease. That four distinct somatic mutations were present in a single patient suggests that in conditions that predispose to PNH PIG-A may be hypermutable.     

Procedure of extended hilar bile duct resection and its application for hilar cholangiocarcinoma

BACKGROUND/AIMS: Several surgical procedures from hilar bile duct resection to hepatectomy have been adopted for hilar cholangiocarcinoma. However the details of the surgical procedure and the indications for hilar bile duct resection have not been determined. METHODOLOGY: Pathohistological outcome of resected specimens in five patients undergoing extended hilar bile duct resection was reviewed and compared with 12 patients undergoing partial hepatectomy with caudate lobectomy. RESULTS: Extended hilar bile duct resection was used for older patients, cases of choledochal site and less invasive tumor. The mean lengths of the left hepatic duct (21.7 +/- 7.8 mm) and the anterior hepatic duct (18.0 +/- 3.2 mm) in the specimens resected by extended hilar bile duct resection did not differ from those seen in right and left hepatectomy, respectively. Furthermore, extended hilar bile duct resection removed partial caudal hepatic duct. However the length of the posterior hepatic duct removed by extended hilar bile duct resection (14.3 +/- 2.0 mm) was significantly less than that excised in left hepatectomy (19.3 +/- 6.6 mm) (P < 0.05). The histologic positive margin rate of the extended hilar bile duct resection group (40%) was the same as that of the hepatectomy group (50%). Papillary or nodular form tumor tended to have positive ductal margins in both surgical techniques. On the other hand, flat tumor tended to have high positive rates in both ductal and excisional margins even in hepatectomy. Two cases with positive surgical margin died of local recurrences, however another 3 cases with negative surgical margin are alive without recurrences from 8 to 20 months after surgery. CONCLUSIONS: The indication of extended hilar bile duct resection for hilar cholangiocarcinoma is limited to cases in which the infiltration is confined to the hepatic bifurcation, such as type I and type II of Bismuth classification with regard to papillary and nodular macroscopic appearance.     

Effects of pulmonary rehabilitation in patients with pulmonary tuberculosis sequelae]

Pulmonary rehabilitation was evaluated for a mean period of 3.9 weeks in 37 inpatients with pulmonary tuberculosis sequelae. The rehabilitation program consisted of relaxation, breathing retraining, exercise training, respiratory muscle training and instruction. Significant improvement was shown in VC (n = 37) on average from 1.48 l to 1.59 l, in FEV1.0 (n = 37) from 0.93 l to 1.02 l, in PaO2 (n = 35) from 67.1 Torr to 72.4 Torr, in 6-minute walking distance (n = 29) from 303 m to 339 m, in Pimax (n = 17) from 38.5 cmH2O to 47.5 cmH2O, in activity (n = 23) from 19.6 points to 22.5 points, in dyspnea (n = 22) from 18.4 points to 22.5 points and in QOL (n = 25) from 39.0 points to 44.2 points. The effects of pulmonary rehabilitation did not depend on past thoracic surgery for tuberculosis, pattern of ventilatory impairment, findings of chest radiography, or degree of insufficiency. These data suggest that pulmonary rehabilitation is of benefit for improving pulmonary function, exercise tolerance, symptoms and QOL in patients with pulmonary tuberculosis sequelae.     

Tumor necrosis factor-alpha inhibits generation of glycophorin A+ cells by CD34+ cells

OBJECTIVE: The inhibitory effects of tumor necrosis factor-alpha (TNF-alpha) on cytokine-induced proliferation and differentiation of normal human erythroid progenitors have been characterized extensively, yet little is known about the maturation level of erythroid progenitors that are sensitive to TNF-alpha or of the expression of TNF receptors (TNFRs) in erythroid lineage. The aim of this study was to determine the extent to which human erythroid progenitor cells are sensitive to TNF-alpha, and to relate this to the expression of TNFRs in the erythroid lineage. MATERIALS AND METHODS: Highly purified human CD34+ cells underwent erythroid differentiation, with or without TNF-alpha. We used colony assay as well as a method by which colony-forming unit-erythroid (CFU-E) and glycophorin A (GPA; a specific marker for erythroid lineage) positive cells can be generated in liquid phase from purified human CD34+ cells in the presence of multiple cytokines, including stem cell factor (SCF), interleukin-3 (IL-3), and erythropoietin (EPO). During erythroid differentiation of CD34+ cells, TNFRs expression were monitored. RESULTS: TNF-alpha inhibited the generation of GPA+ cells by CD34+ cells as well as the proliferative capacity of GPA+ cells supported by EPO, IL-3, and SCF. Erythroid progenitors became resistant to the inhibitory effect of TNF-alpha as they matured. The detectable expression of TNFR-I was transient in the early phase of erythroid differentiation, whereas TNFR-II was expressed through the entire course of erythroid differentiation of CD34+ cells. CONCLUSIONS: TNF-alpha suppresses erythropoiesis by inhibiting the generation of GPA+ cells derived from CD34+ cells as well as by inhibiting the proliferative capacity of GPA+ cells. Although the presence of TNFRs does not directly indicate that the receptor(s) mediates death signaling, altered expression of TNFRs depending on the level of maturation may imply altered sensitivities to TNF-alpha in various stage of erythroid progenitors.     

Reduction of gap junction protein connexin 32 in rat atrophic gastric mucosa as an early event in carcinogenesis

This study was conducted to examine the possible relationship among connexin 32 (Cx32) expression, cell proliferation and differentiation in the normal stomach, N-methyl-N′-nitro-nitrosoguanidine (MNNG)-induced atrophic gastritis, and carcinoma in rats. Atrophic gastritis and adenocarcinoma were induced by the administration of MNNG for 8 and 30 weeks, respectively. Cell proliferation was detected by staining with 5-bromo-2′-deoxyuridine (BrdU). The proliferative zone (BrdU-positive zone), located in the lower third of the gastric gland in controls, was elongated in atrophic gastritis. In adenocarcinoma, BrdU-positive cells were distributed diffusely. Cx32 expression was investigated by an indirect immunofluorecence method. In both control and atrophic gastritis specimens, Cx32 fluorescence was abundant in the surface epithelium, but was rarely detected in the glandular portion or the proliferative zone. The length of the Cx32-positive mucosa was significantly less than the control value in atrophic gastritis and no such positive mucosa was visible in adenocarcinoma. The results of this study indicate that the loss of cell-cell communication through the gap junction, associated with elongation of the proliferative cell zone, may be manifested much earlier than carcinoma. We regard this model as useful for investigating the development of atrophic gastritis into gastric carcinoma.