Methotrexate (MTX) plus ursodeoxycholic acid (UDCA) in the treatment of primary biliary cirrhosis

This placebo-controlled, randomized, multicenter trial compared the effects of MTX plus UDCA to UDCA alone on the course of primary biliary cirrhosis (PBC). Two hundred and sixty five AMA positive patients without ascites, variceal bleeding, or encephalopathy; a serum bilirubin less than 3 mg/dL; serum albumin 3 g/dL or greater, who had taken UDCA 15 mg/kg daily for at least 6 months, were stratified by Ludwig's histological staging and then randomized to MTX 15 mg/m2 body surface area (maximum dose 20 mg) once a week while continuing on UDCA. The median time from randomization to closure of the study was 7.6 years (range: 4.6-8.8 years). Treatment failure was defined as death without liver transplantation; transplantation; variceal bleeding; development of ascites, encephalopathy, or varices; a doubling of serum bilirubin to 2.5 mg/dL or greater; a fall in serum albumin to 2.5 g/dL or less; histological progression by at least two stages or to cirrhosis. Patients were continued on treatment despite failure of treatment, unless transplantation ensued, drug toxicity necessitated withdrawal, or the patient developed a cancer. There were no significant differences in these parameters nor to the time of development of treatment failures observed for patients taking UDCA plus MTX, or UDCA plus placebo. The trial was conducted with a stopping rule, and was stopped early by the National Institutes of Health at the advice of our Data Safety Monitoring Board for reasons of futility. In conclusion, methotrexate when added to UDCA for a median period of 7.6 years had no effect on the course of PBC treated with UDCA alone.     

A respiratory hemocyanin from an insect

Insects possess an elaborate tracheal system that enables transport of gaseous oxygen from the atmosphere directly to the inner organs. Therefore, the presence of specialized oxygen-transport proteins in the circulatory system of insects has been considered generally unnecessary. Here, we show for the first time, to our knowledge, the presence of an ancestral and functional hemocyanin (Hc) in an insect. In the hemolymph of nymphs and adults of the stonefly Perla marginata, a hexameric Hc was identified, which consists of two distinct subunit types of 659 and 655 amino acids. P. marginata Hc displays cooperative oxygen binding with a moderately high oxygen affinity [(half-saturation pressure, P(50) approximately 8 torr (1 torr = 133 Pa)]. No evidence was found for the presence of Hcs in the more evolutionarily advanced holometabolan insects, suggesting that this type of respiratory protein was lost later in insect evolution. However, our results demonstrate that, in contrast to the accepted paradigm, certain basal insects have retained an ancestral blood-based mechanism of gas exchange.     

Hepatocyte-conditioned medium potentiates insulin-like growth factor (IGF) 1 and 2 stimulated DNA synthesis of cultured fat storing cells

ABSTRACT— IGF-1 and IGF-2 stimulate dose-dependently DNA synthesis of nonconfluent cultures of rat fat storing cells, a nonparenchymal type of liver cells pathogenetically involved in the generation of liver fibrosis. Maximum stimulation of [³H] thymidine incorporation of about 2.6-fold above control was reached with 100 ng/ml IGF-1 and 500 ng/ml IGF-2, respectively. The DNA synthesis promoting action of both IGF-1 and IGF-2 was most efficiently potentiated by hepatocyte-conditioned medium raising the stimulatory effect up to 21-fold above control cultures. Lysate of hepatocytes (up to 15 μg protein/ml) was not effective in potentiating the effect of IGF-1. IGF-1 is bound to free carrier protein(s) present in the medium of hepatocytes, but obviously absent in cell lysate. Three molecular weight fractions in the ranges of 67 kd, 35 kd, and 25 kd could be identified in the medium, which potentiate the growth-promoting effect of IGF-1. Applying Western ligand blot analysis, three molecular size classes of IGF-1 binding proteins in the conditioned media of rat hepatocytes were determined. The major binding protein had a M_r of 28–34 kd, a minor portion was localized at M_r 24 kd, whereas trace binding affinities were found at M_r of about 95 kd. It is suggested that IGF-1, IGF-2 and the complex array of IGF-binding proteins secreted by hepatocytes might be involved in the paracrine regulation of growth of fat storing cells. Nonstandard abbreviations: BSA, bovine serum albumin; FCS, fetal calf serum; FSC, fat scoring cells; IGF, insulin-like growth factor; IGFBP, IGF-binding protein; M_r, relative molecular weight; PAGE, polyacrylamide gel electrophoresis; PBS, phosphate-buffered saline; PCcM, hepatocyte-conditioned medium; SDS, sodium dodecyl sulfate; SI, stimulation index.     

Anti-thymocyte globulin overcomes the negative impact of HLA mismatching in transplantation from unrelated donors

OBJECTIVE: About one third of patients requiring allogeneic hematopoetic stem cell transplantation (HSCT) would not find a matched sibling or alternative donor. Allogeneic HSCT from matched unrelated and mismatched donors carries an increased risk of graft-vs-host disease (GVHD) and transplant-related mortality (TRM). MATERIALS AND METHODS: We used anti-thymocyte globulin (ATG-Fresenius) at a median dose of 90 mg/kg body weight as part of a total body irradiation or busulfan-based conditioning regimen for prevention of serious GVHD. All patients received cyclosporine A and short-course methotrexate. We compared outcomes of 65 recipients of human leukocyte antigen (HLA)-mismatched unrelated grafts and 194 recipients of HLA-matched unrelated grafts. Mismatches involved one or two loci. Both groups were comparable in age, graft source, diagnosis, stage of disease, and conditioning regimen, and differed only in dose of ATG administered. RESULTS: For matched and mismatched transplants, respectively, there was no significant difference in graft failure (0.5% vs 3%; p = 0.16), in the cumulative incidence of grade II to IV acute GVHD (45% vs 35%; p = 0.14) and no difference in overall chronic GVHD (42% vs 40%; p = 0.68). Estimated overall survival (OS) and disease-free survival (DFS) at 5 years were 55% vs 50% (p = 0.99) and 47% vs 47% (p = 1.0), respectively. The cumulative incidence of relapse and TRM at 5 years were 24% vs 25% (p = 0.63), and 29% vs 27% (p = 0.59), respectively. CONCLUSION: Inclusion of ATG-Fresenius in the conditioning regimen permits HSCT from mismatched unrelated donors without excess TRM and GVHD, resulting in identical OS and DFS of recipients of HLA-matched and HLA-mismatched grafts.     

Self-expanding metal stents versus plastic prostheses in the palliation of malignant dysphagia: long-term outcome of 153 consecutive patients

BACKGROUND: Malignant dysphagia due to esophagogastric cancer is associated with poor overall prognosis. Placements of self-expandable metal stents or plastic tubes are established methods as palliative treatment options. As an alternative and/or complementary therapy, radiologic techniques (external beam radiation/brachytherapy) and locally endoscopic techniques (laser, APC-beamer, PDT) are often used. STUDY AND GOALS: Retrospective trial of 153 patients treated in our department between 1993 and 2001. Forty-five patients received a plastic tube (Group A) and 108 patients were treated with metal stents (Group B). Both groups were compared for improvement of dysphagia score, survival, recurrent dysphagia and complications. RESULTS: Stent placement was successful in 41 of 45 (93%) patients of Group A and 107 of 108 (99%) of Group B. The median dysphagia score improved significantly in Group A (from 3.03 to 1.55, P = 0.010) and Group B (from 2.77 to 1.44, P = 0.009). Recurrent dysphagia was noted in 12 of 45 (27%) patients of Group A and 27 of 108 (25%) patients of Group B. Median survival time after stent insertion was 78 days (Group A) and 113 days (Group B). Overall complications occurred in 15 of 45 (33%) patients of Group A and 28 of 108 (26%) patients of Group B. However, significantly (P = 0.05) more major complications were seen in Group A than in Group B (22% vs. 9%). CONCLUSIONS: Our results indicate a marginal clinical benefit for metal stents versus plastic tubes in malignant dysphagia in the long run. However, metal stents seem to be safer and associated with a prolonged improvement of dysphagia score.     

The genome of Clostridium kluyveri, a strict anaerobe with unique metabolic features

Clostridium kluyveri is unique among the clostridia; it grows anaerobically on ethanol and acetate as sole energy sources. Fermentation products are butyrate, caproate, and H₂. We report here the genome sequence of C. kluyveri, which revealed new insights into the metabolic capabilities of this well studied organism. A membrane-bound energy-converting NADH:ferredoxin oxidoreductase (RnfCDGEAB) and a cytoplasmic butyryl-CoA dehydrogenase complex (Bcd/EtfAB) coupling the reduction of crotonyl-CoA to butyryl-CoA with the reduction of ferredoxin represent a new energy-conserving module in anaerobes. The genes for NAD-dependent ethanol dehydrogenase and NAD(P)-dependent acetaldehyde dehydrogenase are located next to genes for microcompartment proteins, suggesting that the two enzymes, which are isolated together in a macromolecular complex, form a carboxysome-like structure. Unique for a strict anaerobe, C. kluyveri harbors three sets of genes predicted to encode for polyketide/nonribosomal peptide synthetase hybrides and one set for a nonribosomal peptide synthetase. The latter is predicted to catalyze the synthesis of a new siderophore, which is formed under iron-deficient growth conditions.     

Hydroxyurea for sickle cell disease in children and for prevention of cerebrovascular events: the Belgian experience

Hydroxyurea (HU) is considered to be the most successful drug therapy for severe sickle cell disease (SCD). Nevertheless, questions remain regarding its benefits in very young children and its role in the prevention of cerebrovascular events. There were 127 SCD patients treated with no attempt to reach maximal tolerated doses who entered the Belgian Registry: 109 for standard criteria and 18 who were at risk of stroke only. During 426 patient-years of follow-up for patients with standard criteria, 3.3 acute chest syndromes, 1.3 cerebrovascular events, and 1.1 osteonecrosis per 100 patient-years were observed. A subgroup of 32 patients followed for 6 years experienced significant benefit over this period. In each subgroup of children (younger than 2 years, 2-5, 6-9, and 10-19 years) followed for 2 years, clinical and biologic changes were similar, except for children younger than 2 years who had no total hemoglobin increase and remained at risk of severe anemia. In 72 patients evaluated by transcranial Doppler studies (TCD), 34 patients were at risk of primary stroke and only 1 had a cerebrovascular event after a follow-up of 96 patient-years. These results confirm the benefit of HU, even in very young children, and its possible role in primary stroke prevention.     

Molecular alterations in chronic ulcerative colitis-associated and sporadic hyperplastic polyps: a comparative analysis

OBJECTIVES: There is growing interest in the biological and molecular features and neoplastic potential of colonic hyperplastic polyps because of the recent finding of K-ras mutations in many of these lesions. Hyperplastic polyps may also develop in chronic ulcerative colitis (CUC), but it is unclear if these are biologically similar to the sporadic type. The aim of this study was to evaluate and compare the molecular profile of CUC-associated hyperplastic polyps with sporadic hyperplastic polyps of the colon. METHODS: Thirty-nine hyperplastic polyps from 26 CUC patients, 39 sporadic hyperplastic polyps from 29 age- and sex-matched patients without CUC, and 26 colonic mucosal biopsies from 22 patients with CUC but without hyperplastic polyps were analyzed by polymerase chain reaction for loss of heterozygosity of APC, 3p, p53, and p16 and for mutations in codons 12, 13, and 61 of the K-ras gene. Immunohistochemical evaluations for the proliferation-associated nuclear peptide Ki67 (MIB-1) and p27 were also performed on a subset of hyperplastic polyps. RESULTS: CUC-associated hyperplastic polyps showed a proportion of genetic alterations (47%) similar to that of sporadic hyperplastic polyps (33%) (p > 0.05), and neither significantly differed from chronically inflamed mucosae in CUC patients without hyperplastic polyps. Furthermore, in a small group of CUC patients in which informative tissue was available from both their hyperplastic polyps and adjacent flat colitic mucosae, the polyps contained mutations that were not present in the underlying mucosa. Loss of heterozygosity of APC, 3p, p53, p16, and K-ras mutations were present in 21%, 40%, 27%, 20%, and 19% of CUC patients with hyperplastic polyps, respectively, and in 0%, 11%, 20%, 13%, and 13% of non-CUC patients with sporadic polyps, respectively. Both CUC-associated and sporadic hyperplastic polyps showed a substantial number of cases (46% and 64% of cases, respectively) with loss of p27 expression, and both types of lesions showed similar MIB-1 proliferation indices. CONCLUSIONS: These data suggest that CUC-associated hyperplastic polyps are genotypically similar to the sporadic type. This study adds to the expanding list of molecular alterations that have been discovered in hyperplastic polyps, and lends further support to the controversial theory that these lesions may have neoplastic potential.