Management of osteoporosis in primary biliary cirrhosis.

Osteoporosis is not a significant problem in the majority of patients with primary biliary cirrhosis (PBC). However, substantial bone-related morbidity may occur in patients with advanced disease, in particular after liver transplantation. The cause of osteoporosis in PBC is multifactorial, and pathophysiological mechanisms specifically related to PBC have not been defined. In general, the principles of management followed in post-menopausal osteoporosis also apply in chronic liver disease. Dual energy X-ray absorptiometry is currently the method of choice for monitoring bone mineral density. Avoidance of conditions with potential negative effects on bone mass, and maintaining adequate serum vitamin D levels and calcium intake form the cornerstone in preventing osteoporosis. Bisphosphonates are the most logical choice when specific medical treatment of PBC-associated osteoporosis is indicated, as well as for preventing bone loss during glucocorticoid treatment and after liver transplantation. Recent studies suggest that active vitamin D analogues are effective alternatives in the post-transplant setting.     

Modified guanidinium thiocyanate method for human sperm DNA isolation

Mammalian sperm chromatin is highly condensed, so isolating DNA from such chromatin can be a formidable task. The procedures that produce high quality DNA from somatic cells fail to yield quality sperm DNA. In this study we have modified the previously used guanidinium method to make it simple and efficient in isolating human sperm DNA. In our method, the lysis buffer contained guanidinium, sodium citrate, sarkosyl, proteinase K and mercaptoethanol. Proteinase K was not used in the original guanidinium method but was included in our protocol. CsCl centrifugation of the lysate, as described in the original procedure, was omitted. Instead, isopropyl alcohol was added directly to the lysis buffer to harvest the DNA. This modified guanidinium method generated high molecular weight DNA while the other two methods resulted in considerable DNA degradation. There was no difficulty in restriction enzyme digestion of DNA prepared by the modified method as revealed by Southern blot analysis. Since the modified guanidinium method is a simple one-step procedure which avoids homogenization, organic solvents, centrifugation and, more importantly, produces degradation-free DNA, it could be the method of choice when DNA from mature germ cells is needed.      

A syndrome resembling thrombotic thrombocytopenic purpura associated with human parvovirus B19 infection.

This is the first report of a patient with a syndrome resembling thrombotic thrombocytopenic purpura associated with a recent human parvovirus B19 infection.     

Double-blind, dose-range-finding study of fleroxacin (RO 23-6240; AM-833) for treatment of complicated urinary tract infections.

In a double-blind randomized trial, we evaluated the efficacy and safety of three oral dosage regimens of fleroxacin, a new fluoroquinolone, once daily in 62 patients for the treatment of complicated urinary tract infections. The regimens compared were 200 mg for 10 days (n = 20), 400 mg for 10 days (n = 21), and 600 mg for 10 days (n = 21). Forty-five patients were evaluable for efficacy. A clinical cure was reached in 78% of the patients. Overall, a favorable bacteriological response (negative culture or reinfection at 4 to 6 weeks) was obtained in 36 of 45 (80%) patients. No significant difference could be found among the three dosage groups. During therapy, one Klebsiella ozaenae strain became resistant and one Pseudomonas aeruginosa strain became less susceptible to fleroxacin. In 13 patients, therapy had to be discontinued due to major adverse events (oliguria [n = 1], psychosis [n = 1], photosensitivity [n = 1], insomnia [n = 1], and nausea [n = 9]). Minor side effects were seen in 13 other patients. Increased dosage correlated significantly (P less than 0.01) with total number of adverse events.     

Thymus dysfunction and chronic inflammatory disease in gp39 transgenic mice

Expression of gp39 on activated T cells provides a co-stimulatory signal in peripheral lymphoid tissue that regulates humoral and cell- mediated immunity. The function of gp39 and its receptor CD40 in thymus remains uncertain. Here we report that overexpression of gp39 in transgenic mouse thymus caused a dose-dependent decline in thymocyte numbers (> 500 fold), loss of cortical epithelium and expansion of CD40+ medullary cells. Transplantation of transgenic bone marrow into normal mice indicated that gp39 significantly diminished thymocyte viability in the context of a 'normal' thymic environment. The peripheral tissues of transgenic mice also accumulated abnormalities in a transgene dose-dependent manner that involved inflammation and lymphoid tissue hypertrophy. Animals with the highest transgene copy numbers acquired a lethal inflammatory bowel disease marked by the infiltration of gp39+ T cells and CD40+ cells into diseased tissues. Examination of cells overexpressing gp39 suggested that these defects were caused, in part, by the saturation of a mechanism that sequesters gp39 inside non-activated cells and thus protects the immune system from inappropriate gp39-CD40 interaction. These results establish a regulatory role for gp39 in thymus function and a causal relationship in mediating chronic inflammatory disease.      

Nontoxigenic strains of Clostridium difficile lack the genes for both toxin A and toxin B.

A total of 39 toxigenic and 20 nontoxigenic strains of Clostridium difficile were tested for the presence of either toxin A or toxin B by the polymerase chain reaction (PCR). All toxigenic strains produced cytotoxin as assayed by using highly sensitive fetal lung fibroblasts and were positive for toxin A as well as toxin B in the PCR assay. All nontoxigenic strains failed to produce toxin and were negative in the PCR assay. This study shows that nontoxigenic strains of Clostridium difficile lack the toxin A as well as the toxin B gene.     

Metabolic encephalopathy can be a potentially life-threatening complication from valproic acid

In two female patients of 62 and 81 years old, a metabolic encephalopathy was diagnosed which was ascribed to the use of valproic acid. Both had elevated ammonia levels in arterial blood, without hepatic failure. The first patient eventually became comatose and required artificial ventilation. After discontinuation of the valproic acid and with the aid of supportive measures, both women recovered. In patients with an impaired level of consciousness who are using valproic acid, a metabolic encephalopathy caused by this drug should be considered. Elevated levels of ammonia can be found but are not mandatory. Discontinuation of valproic acid will lead to recovery of consciousness.