Expansion of CTG repeat in myotonin protein kinase gene on Alu(ins)-HinfI-I background in a myotonic dystrophy patient from India. Mutations in brief no. 210. Online

To determine the founder of Indian myotonic dystrophy mutation, we have studied the expansion of CTG repeats in myotonin protein kinase gene and two intragenic linked loci Alu(ins) / Alu(del) and G/T intron 9 HinfI polymorphism in ten unrelated DM patients from eastern India. Out of these ten patients, reconstruction of haplotype was possible for five patients unambiguously. In the other five cases, haplotype for the normal allele was assumed to be the most common haplotype found in normal individuals from Indian populations. Such analysis showed that in nine cases, the expansion of CTG repeats took place on Alu(ins)-HinfI-2 background indicating common founder with other DM mutation published. However, in one case we observed a different haplotype [Alu(ins)-HinfI-1] which could be a new mutation or due to admixture.     

Congenital leukaemia in Down Syndrome--a case report

A 17 days old male infant, who had features of Down Syndrome, presented with fever, refusal to feed and seizures. He had papular, crusted skin lesions, moderate hepatosplenomegaly and a rapid downhill course. Peripheral blood and bone marrow aspirate showed features of acute leukaemia. Congenital Leukaemia is a rare malignancy associated with a very poor prognosis. Paradoxically, many cases of Congenital Leukaemia, especially in infants with Down Syndrome, show spontaneous remission.     

Targeting cysteine residues of human immunodeficiency virus type 1 protease by reactive free radical species

Nitric oxide (NO) is a naturally occurring free radical with many functions. The oxidized form of NO, the nitrosonium ion, reacts with the thiol group of cysteine residues resulting in their modification to S-nitrosothiols. The human immunodeficiency virus type 1 (HIV-1) protease (HIV-PR) has two cysteine residues that are conserved amongst different viral isolates found in patients with acquired immunodeficiency syndrome (AIDS). In an active dimer, these residues are located near the surface of the protease. We have found that treatment of HIV-PR with different NO congeners results in loss of its proteolytic activity and simultaneous formation of S-nitrosothiols. Sodium nitroprusside inhibited HIV-PR up to 70% and S-nitroso-N-acetylpenicillamine completely inhibited the protease within 5 min of treatment. The pattern of inhibition by NO donors is comparable to its inhibition by N-acetyl pepstatin. Using electrospray ionization-mass spectrometry, we identified the modification of HIV-PR by NO as that of S-nitrosation. Our findings point towards a possible role of NO in mediating resistance to HIV-1 infection.     

Hepatitis C virus core protein modulates the interferon-induced transacting factors of Jak/Stat signaling pathway but does not affect the activation of downstream IRF-1 or 561 gene

Hepatitis C virus (HCV) has a propensity to cause chronic infection, with a low proportion of patients exhibiting a sustained response to interferon-alpha (IFNalpha) therapy. An earlier report suggested that HCV inhibits IFNalpha-induced signal transduction through the Jak/Stat pathway by preventing the formation of the transacting factor ISGF3 complex, although the effect on downstream pathway and the specific viral protein responsible for inhibition of IFNalpha-mediated signal transduction were not elucidated. HCV core protein displays a number of intriguing functional properties and has been implicated in virus-mediated pathogenesis. In this study, we have analyzed the effect of core protein upon IFNalpha- or IFNgamma-induced regulation of the Jak/Stat signaling pathway. HCV core protein expression exhibited a reduced Stat1 expression in IFN-treated mammalian cells. A gel retardation assay suggested a reduced level of formation of the transacting factors, GAF and ISGF3, in IFN-treated cells. Further studies from protein expression and RNase protection assay revealed that the reduced level of GAF or ISGF3 formation could be attributed to modulation of Stat1 protein expression, an important player for innate immunity in host defense mechanism. However, these modulatory effects did not interfere with the activation of the downstream effector genes, IRF-1 and 561, in IFN-treated cells. Stable transfectants of cells after introduction of a plasmid DNA encoding both the structural and the nonstructural proteins of HCV also exhibited a similar effect. Taken together, these results suggest that although expression of the core protein alone or with other HCV proteins modulate transacting factors of Jak/Stat signaling pathway, expression of the downstream effector genes IRF-1 and 561 remains unaffected upon IFN treatment and may contribute to host defense mechanism.     

Fever-like temperature induces maturation of dendritic cells through induction of hsp90

Fever is a phylogenetically conserved biological phenomenon and a common consequence of infection. Here, we examine in vitro and in vivo the effect of febrile temperature on dendritic cells (DC), a key antigen-presenting cell in the immune system. Elevated temperatures are observed to cause immature DC to mature, specifically through elevation of intracellular levels of hsp90. Surprisingly, even brief exposure to elevated temperatures has a powerful effect on the immunostimulatory capacity of DC. These results bear on the mechanisms of the salutary effects of fever as well as of behavioral elevations of temperature such as saunas and warm blankets.     

Oral tonsils: an immunoperoxidase study

Tissue morphometry and the distribution of cells containing immunoglobulin (Ig), J chain and secretory component (SC) were studied in eight oral tonsils. Quantitative immunohistochemistry revealed that IgG-containing cells predominated in all lymphoid compartments (follicles, extrafollicular areas and reticular epithelium) and that the IgG:IgA:IgM class ratios of the overall tonsillar immunocyte population were 13:8:2. Cells containing IgD and IgE were rare. IgG immunocytes showed no significant localisation within a given lymphoid compartment, whereas IgA cells were found predominantly in extrafollicular areas, especially adjacent to surface epithelium, and IgM cells were in follicles. J chain was present within IgM and some IgA cells. Tonsillar crypt and surface epithelium was negative for SC, suggesting that these structures are not directly involved in local mucosal immunity.     

Application of validated mapping algorithms between generic PedsQL scores and utility values to individuals with sickle cell disease

Quality of Life Research - There is a paucity of empirically estimated health state utility (HSU) values to estimate health-related quality of life among individuals with sickle cell disease (SCD)....