A pilot study of polyunsaturated phosphatidyl choline in fulminant and subacute hepatic failure

Present pilot study was conducted to evaluate efficacy and safety of polyunsaturated phosphatidyl choline (PPC) in a phase III clinical trial in patients of fulminant and subacute hepatic failure over one year period in a prospective randomised blinded controlled design. We found that in patients of fulminant hepatic failure, recovery period from encephalopathy was faster and mortality rate lower in the test group of patients who received PPC in a dose of 350 mg thrice daily for 6 to 8 weeks as compared to the control groups who did not receive it. In the patients of subacute hepatic failure, recovery from encephalopathy was faster, mortality rate lower and regression of ascites was significantly higher (P = 0.0022) in test group of patients who received PPC as compared to the control group. However, as the number of patients in the present pilot study is small, we propose that larger clinical trials are warranted in this direction to prove the efficacy and safety of PPC in fulminant and subacute hepatic failure.     

Direct detection and identification of Mycobacterium tuberculosis and Mycobacterium bovis in bovine samples by a novel nested PCR assay: correlation with conventional techniques

Mycobacterium tuberculosis and M. bovis infect animals and humans. Their epidemiologies in developed and developing countries differ, owing to differences in the implementation of preventive measures (World Health Organization, 1999). Identification and differentiation of these closely related mycobacterial species would help to determine the source, reservoirs of infection, and disease burden due to diverse mycobacterial pathogens. The utility of the hupB gene (Rv2986c in M.tuberculosis, or Mb3010c in M.bovis) to differentiate M. tuberculosis and M. bovis was evaluated by a PCR-restriction fragment length polymorphism (RFLP) assay with 56 characterized bovine isolates (S. Prabhakar et al., J. Clin. Microbiol. 42:2724-2732, 2004). The degree of concordance between the PCR-RFLP assay and the microbiological characterization was 99.0% (P < 0.001). A nested PCR (N-PCR) assay was developed, replacing the PCR-RFLP assay for direct detection of M. tuberculosis and M. bovis in bovine samples. The N-PCR products of M. tuberculosis and M. bovis corresponded to 116 and 89 bp, respectively. The detection limit of mycobacterial DNA by N-PCR was 50 fg, equivalent to five tubercle bacilli. M. tuberculosis and/or M. bovis was detected in 55.5% (105/189) of the samples by N-PCR, compared to 9.4% (18/189) by culture. The sensitivities of N-PCR and culture were 97.3 and 29.7, respectively, and their specificities were 22.2 and 77.7%, respectively. The percentages of animals or samples identified as infected with M.tuberculosis or M. bovis by N-PCR and culture reflected the clinical categorizations of the cattle (P of <0.05 to <0.01). Mixed infection by N-PCR was detected in 22 animals, whereas by culture mixed infection was detected in 1 animal.     

Regulation of the replication initiator protein p65cdc18 by CDK phosphorylation

Cyclin-dependent kinases (CDKs) promote the initiation of DNA replication and prevent reinitiation before mitosis, presumably through phosphorylation of key substrates at origins of replication. In fission yeast, the p65^cdc18 protein is required to initiate DNA replication and interacts with the origin recognition complex (ORC) and the p34^cdc2 CDK. Here we report that p65^cdc18 becomes highly phosphorylated as cells undergo the G₁→S phase transition. This modification is dependent on p34^cdc2 protein kinase activity, as well as six consensus CDK phosphorylation sites within the p65^cdc18 polypeptide. Genetic interactions between cdc18⁺ and the S-phase cyclin cig2⁺ suggest that CDK-dependent phosphorylation antagonizes cdc18⁺ function in vivo. Using site-directed mutagenesis, we show that phosphorylation at CDK consensus sites directly targets p65^cdc18 for rapid degradation and inhibits its replication activity, as strong expression of a constitutively hypophosphorylated mutant form of p65^cdc18 results in large amounts of DNA over-replication in vivo. Furthermore, the over-replication phenotype produced by this mutant p65^cdc18 is resistant to increased mitotic cyclin/CDK activity, a known inhibitor of over-replication. Therefore, p65^cdc18 is the first example of a cellular initiation factor directly regulated in vivo by CDK-dependent phosphorylation and proteolysis. Regulation of p65^cdc18 by CDK phosphorylation is likely to contribute to the CDK-driven “replication switch” that restricts initiation at eukaryotic origins to once per cell cycle.     

New evidence from magnetic resonance imaging of brain changes after climbs at extreme altitude

The aim of the present study was to look for anatomical changes in climbers' brains, using magnetic resonance imaging (MRI), after extremely high-altitude climbs and to relate them to possible associated risk factors. Clinical history, neurological examinations and MRI were carried out on a group of nine climbers before and after climbing to over 7500 m without the use of supplementary oxygen. None of the subjects showed any neurological dysfunctions. In five climbers MRI abnormalities (high signal areas, cortical atrophy) were observed before the expedition. After the descent, two of them showed new high intensity signal areas recorded by MRI. Both subjects suffered severe neurological symptoms during the climb. The present study suggested that the brain changes observed by MRI could be related to the severity of clinical events at high altitude. However, we do not know the exact meaning of such MRI findings or the reason for their location, predominantly in posterior regions of the brain. The new evidence that a high percentage of climbers show MRI brain abnormalities, and especially the appearance of changes after the ascent, reinforces the possibility of a potential neurological risk in high-altitude climbing.     

Water-clear cell adenoma of the parathyroid gland: a rare entity

Water-clear cell hyperplasia is a rare but well-documented cause of primary hyperparathyroidism. Parathyroid adenomas of water-clear cell type are exceptionally rare, and only five case reports are available at present in the medical literature. We report an additional case of water-clear cell adenoma of the parathyroid gland, and the differential diagnoses are discussed.     

Molecular characterization of a carnation etched ring virus isolate from India

Incidence of the Carnation etched ring virus (CERV), the only DNA virus reported to date on carnation, was investigated by a bioassay using a partially purified virus as inoculum and then by a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Out of 61 carnation cultivars analyzed 41 (67%) were found positive. The virus positivity was verified by polymerase chain reaction (PCR) and nucleotide sequencing. The amplified 1349 bp fragment was by about 98% and 96% identical with respect to coat protein (CP) and enzymatic polyprotein genes, respectively, as compared to the sequences available in the database. In terms of amino acid sequence similarity, the homology values were 99% and 97%, respectively. Comparison with other caulimoviruses revealed that CERV is most closely related to the Cauliflower mosaic virus (CaMV). High genetic stability of CERV may be attributed to the fact that it has evolved from the same initial sequence in an original host. Because of global market of cut flowers and vegetative propagation it has been dispersed around the world.     

Molecular cloning and characterization of a novel gene of Candida albicans,CDR1, conferring multiple resistance to drugs and antifungals

By functional complementation of a PDR5 null mutant of Saccharomyces cervisiae, we have cloned and sequenced the multidrug-resistance gene CDR1 of Candida albicans. Transformation by CDR1 of a PDR5-disrupted host hypersensitive to cycloheximide and chloramphenicol resulted in resistance to cycloheximide, chloramphenicol and other drugs, such as the antifungal miconazole, with collateral hypersensitivity to oligomycin, nystatin and 2,4 dinitrophenol. Our results also demonstrate the presence of several PDR5 complementing genes in C. albicans, displaying multidrug-resistance patterns different from PDR5 and CDR1. The nucleotide sequence of CDR1 revealed that, like PDR5, it encodes a putative membrane pump belonging to the ABC (ATP-binding cassette) superfamily. CDR1 encodes a 1501-residue protein of 169.9 kDa whose predicted structural organization is characterized by two homologous halves, each comprising a hydrophobic region with a set of six transmembrane stretches, preceded by a hydrophilic nucleotide binding fold.