Bryostatin 1-induced modulation of nucleoside transporters and 2-chlorodeoxyadenosine influx in WSU-CLL cells

WSU-CLL cells, a fludarabine resistant B-cell chronic lymphocytic leukemia cell line, has been shown to exhibit enhanced sensitivity to 2-chlorodeoxyadenosine (2-CdA) following 48-72 h exposure to bryostatin 1. For 2-CdA to manifest its chemotherapeutic activity, it must first enter the cell through one of several specific nucleoside transporter systems. We present data to show that bryostatin 1-induced enhanced influx of 2-CdA is in part the result of bryostatin 1-induced modulation of nucleoside transporters in WSU-CLL cells. The bi-directional equilibrative NBMPR sensitive transporters in WSU-CLL cells were significantly down-regulated 90 min post-exposure to 1-200 nM bryostatin 1. This down-regulation was evident up to 144 h. In contrast, WSU-CLL cells exhibited a transient increase in Na+-dependent concentrative 2-CdA influx from 48 to 96 h after bryostatin 1 exposure which was evident for a longer duration than that accounted for by the increase in deocycytidine kinase activity. These data may, in part, explain the enhanced efficacy of 2-CdA seen in WSU-CLL cells following 48-72 h exposure to bryostatin 1. It may raise questions as to the importance of the bi-directional transporters in determining the resistance or sensitivity of CLL cells to 2-CdA or other nucleoside analogues.     

DFNB39, a recessive form of sensorineural hearing impairment, maps to chromosome 7q11.22-q21.12

This article describes the identification of a novel locus (DFNB39) responsible for an autosomal recessive form of hearing loss segregating in a Pakistani consanguineous family. The hearing impaired members of this family present with profound prelingual sensorineural hearing impairment and use sign language for communications. Linkage was established to microsatellite markers located on chromosome 7q with a maximum multipoint lod score of 3.8. The region of homozygosity spans a 19 cM region that is bounded by markers D7S3046 and D7S644.     

Non-MHC driven exacerbation of experimental thyroiditis in the postpartum period

Many human autoimmune diseases, including those of the thyroid gland, are affected by immune changes during pregnancy and the postpartum period. To investigate this influence, we have developed an animal model of pregnancy thyroiditis by using thyroglobulin (Tg)-induced experimental autoimmune thyroiditis (EAT). We now report a study of the post-partum period in mice with EAT. At 5 weeks postpartum, which was 9 weeks after the completion of a Tg immunization regime, the mean thyroiditis grade was significantly increased in the postpartum group from 0.23 to 0.43 (p<0.05) and the thyroiditis Index, which reflected both the frequency and severity of thyroiditis, was similarly increased compared to controls (29.0 vs 9.0). When Tg immunized CBA/J (H-2k) female mice were mated with BALB/c (H-2d) males, there was a similar increase in the severity of thyroiditis in the postpartum period as seen with CBA/J males suggesting that allogeneic factors were not able to further this postpartum exacerbation. Spleen cell IL-4 secretion was enhanced in the postpartum but only in the presence of thyroiditis indicating enhanced activity of Th2 immune responses. There were no differences in IFN-gamma secretion, titers of anti-Tg, CD8+ & CD4+ T cells and T cell chemokine receptor (CCR5, CCR3) expression between non-pregnant control mice with thyroiditis and postpartum thyroiditis. In summary, we found that the severity of EAT during the postpartum was significantly greater than in non-pregnant control mice and was associated with enhanced Th2 immune responses. The allogenicity of the pregnancy had no influence on these findings. The lack of allogenic impact was in contrast to earlier observations in pregnancy itself where an exacerbation of thyroiditis was male strain-dependent and involved primarily Th1 responses. This indicated that the postpartum exacerbation of autoimmune thyroid disease was not a simple response to fetal antigens but secondary to unique postpartum factors.     

CD1 genotyping of patients with Mycobacterium malmoense pulmonary disease

Mycobacterium malmoense is an opportunistic mycobacterium that occasionally causes disease in non-immunosuppressed individuals. As only a few individuals exposed to these organisms actually develop clinical disease, it is possible there is a genetic component to susceptibility. CD1 molecules are capable of presenting antigens from more virulent mycobacteria to T cells; therefore, we were interested in discovering whether recently described polymorphisms in CD1 molecules modulated susceptibility to M. malmoense pulmonary disease. The CD1 system comprises five genes (CD1A, -B, -C, -D, and -E) located on chromosome 1 (1q22-23). CD1 molecules are structurally and functionally related to major histocompatibility complex (MHC) class I molecules and are expressed on dedicated antigen-presenting cells. The primary function of CD1 molecules is to present lipid and glycolipid antigens to T cells. We have developed an allele-specific polymerase chain reaction-sequence-specific primer (PCR-SSP) method of CD1 genotyping. Using this method, we compared the allele and haplotype frequencies of CD1 in 49 HIV-negative patients with M. malmoense pulmonary disease with those in 342 normal controls. The CD1A and CD1E alleles were nominally identified as CD1A*01, CD1A*02, CD1E*01 and CD1E*02, and the control gene frequencies were found to be 5%, 95%, 67% and 33%, respectively. No significant difference was observed between the patient and control cohorts. Positive linkage disequilibrium values of 0.73 were observed between CD1A*02 and CD1E*01 (P<0.0001; chi2 test), and 0.94 between CD1A*01 and CD1E*02 (P<0.0001; chi2 test). Typing was also performed for two previously described CD1D alleles (CD1D*01 and CD1D*02), although only CD1D*01 was detected.     

Wegener's granulomatosis. Immunomicroscopic and ultrastructural study of four cases

Four cases of Wegener's granulomatosis involving lung are reported in which immunomicroscopy demonstrated that the parenchymal and vascular infiltrates were composed primarily of T cells and monocytes. No IgG, IgA, IgM, or C3 was identified in pulmonary vessels or alveolar septa. Ultrastructural studies failed to demonstrate dense deposits in alveolar septal capillaries or interstitium. These findings indicate that a cellular immune mechanism is active in these forms of pulmonary vasculitis and that immune complex deposition does not play a role.     

Inflammation: the link between insulin resistance, obesity and diabetes

Recent data have revealed that the plasma concentration of inflammatory mediators, such as tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), is increased in the insulin resistant states of obesity and type 2 diabetes, raising questions about the mechanisms underlying inflammation in these two conditions. It is also intriguing that an increase in inflammatory mediators or indices predicts the future development of obesity and diabetes. Two mechanisms might be involved in the pathogenesis of inflammation. Firstly, glucose and macronutrient intake causes oxidative stress and inflammatory changes. Chronic overnutrition (obesity) might thus be a proinflammatory state with oxidative stress. Secondly, the increased concentrations of TNF-alpha and IL-6, associated with obesity and type 2 diabetes, might interfere with insulin action by suppressing insulin signal transduction. This might interfere with the anti-inflammatory effect of insulin, which in turn might promote inflammation.     

Alopecia universalis as a single abnormality in an inbred Pakistani kindred

A Pakistani kindred comprising 5 generations contained 9 males and 4 females with alopecia universalis as a single abnormality without any associated defects. The skin biopsy from the scalp showed hair follicles without hair. Analysis of the pedigree is strongly suggestive of autosomal recessive inheritance, and consanguineous loops could account for all affected persons being homozygous for the abnormal allele. © 1993 Wiley-Liss, Inc.     

Identification of a Strong Promoter of Bacteriophage MB78 that Lacks Consensus Sequence Around Minus 35 Region and Interacts with Phage Specific Factor

A strong promoter of bacteriophage MB78 does not have minus 35 consensus sequence although it has a TGn motif immediately upstream of minus 10 sequence as well as the AT rich UP element. It is efficiently recognised by the sigma 70 RNA polymerase, however, a phage-specific factor competes with sigma 70 RNA polymerase for binding to this region, the binding of the factor being stronger than that of the polymerase. Contrary to the reports in the literature the polymerase appears not to bind to the UP element whereas the phage-specific factor does. The latter seems to be involved in the regulation of the promoter activity. This revised version was published online in July 2006 with corrections to the Cover Date.