Regional variation in the lamina propria T cell receptor V beta repertoire in normal human colon

The Ewing's sarcoma cell line RD-ES, which carries the EWS/FLI-1 fusion gene, responded to the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor lovastatin with growth arrest. Replenishment of mevalonate (MVA) to the arrested cells restored cell growth. However, if tunicamycin (TM), which is an inhibitor of N-linked glycosylation, was present together with MVA the cells remained arrested, indicating that N-linked glycosylation is of importance for growth of Ewing's sarcoma cells. Inhibition of the biosynthesis of EWS/FLI-1 fusion protein by treatment with antisense oligonucleotides also led to growth arrest, suggesting that this protein is of importance for cell growth. We investigated whether MVA synthesis and N-linked glycosylation could be involved in regulation of the expression of the EWS/FLI-1 fusion protein, which in fact contains four potential sites for N-linked glycosylation. We found that inhibition of both HMG-CoA reductase and N-linked glycosylation drastically decreased the expression of the fusion protein, which mainly appears in the cell nuclei. There was no significant difference in the inhibitory effect on the fusion protein between the cytoplasm and the cell nuclei, indicating that the transport of the fusion protein to the cell nucleus is not affected. The fusion protein did not exhibit any gel electrophoretic mobility shift after treatment of the cells with lovastatin or TM, and it did not incorporate [3H]glucosamine. Therefore we can conclude that the fusion protein is not a glycoprotein. The decreased expression of the fusion protein following lovastatin or TM treatment was found to be due to a lowered stability of de novo-synthesized fusion protein. The down-regulation of the fusion protein was correlated to growth arrest. Furthermore, the kinetics between the expression of EWS/FLI-1 fusion protein and the initiation of DNA synthesis in MVA-stimulated cells were similar. Taken together, our data suggest that the regulatory role of N-linked glycosylation in the expression of the EWS/FLI-1 fusion protein is important for growth of Ewing's sarcoma cells. Possible mechanisms underlying TM-induced decrease in EWS/FLI-1 expression may involve the breaking of growth factor receptor pathways.     

Retrospective analysis of the Beijing family of Mycobacterium tuberculosis in preserved lung tissues

Direct repeat spoligotyping of 85 paraffin-embedded lung biopsies was used to investigated the occurrence around Beijing of the Beijing family of Mycobacterium tuberculosis. Samples ranged in time from 1956 to 1990. Hybridization patterns were found with 49 (58%) samples, and 45 (92%) produced typical Beijing family patterns extending over the 34-year period.     

Blood pressure changes during short-term fluoxetine treatment

PURPOSE: To evaluate the potential diagnostic role of mediastinal sonography in patients with cystic fibrosis (CF), we screened the mediastinum of adult CF patients with and without signs of infection and healthy controls. METHODS: Fifty-four consecutive adult patients with CF and 53 healthy volunteers underwent high-resolution mediastinal sonography. The paratracheal region and aorticopulmonary window of each subject were examined for lymph nodes. Each patient was screened for clinical signs of infection. RESULTS: Lymph nodes were detectable in the mediastinum of 39 of 50 CF patients (78%); the mean total lymph node volume was 1.5 +/- 1.7 cm3. Lymph nodes were detectable in the mediastinum of 31 of 50 controls (62%); the mean total lymph node volume in this group was 0.3 +/- 0.3 cm3 (p < 0.001). In the 30 CF patients with signs of infection, the mean total lymph node volume was larger (2.0 +/- 1.8 cm3) than in the 20 CF patients without signs of infection (0.7 +/- 0.9 cm3; p = 0.002). CONCLUSIONS: These results indicate that lymph node volume determination by high-resolution mediastinal sonography may help assess inflammatory activity in patients with CF.     

A randomized, controlled trial of a behavioral intervention to prevent sexually transmitted disease among minority women

Using annual bite-wing radiographs, the incidence and progression of approximal caries (4d-7m) were assessed longitudinally in teenagers and adolescents whose treatment had been based on remineralizing rather than restorative strategies. A closed cohort of 536 children initially was followed from 11 to 22 years of age. The scoring system was: 0 = no visible radiolucency; 1-2 = radiolucency in the enamel up to the enamel-dentin border; 3 = radiolucency with a broken enamel-dentin border but with no obvious progression in the dentin; 4 = radiolucency with obvious spread in the outer half of the dentin, and 5 = radiolucency in the inner half of the dentin. Caries rates were estimated as the number of new lesions/100 tooth surface-years, and the Kaplan-Meier estimate was used to calculate the cumulative survival time of each approximal surface. Three events were used: the transitions from states 0 to 2, 2 to 4 and 3 to 4. The results showed a considerable variation between the surfaces in both caries rates and survival time. For all surfaces combined, the median caries rate from state 0 to 2 was 3.9 new lesions/100 tooth surface-years; from state 2 to 4, the rate was 5.4, and from state 3 to 4 it was 20.3. Of the sound surfaces (state 0), 75% survived 6.3 years without reaching state 2. Given state 2, 75% survived 4.8 years without reaching the outer half of the dentin (state 4), while given a lesion at the enamel-dentin border (state 3), 75% survived 1.3 years without doing the same. The median survival time of lesions from state 3 to 4 was 3.1 years. The group with DMFSappr>1 at the age of 11-12 years had a risk of new approximal enamel lesions (state 0-2) that was 2.5 times greater than that of the group with DMFSappr = 0-1.     

Efficient autoproteolytic processing of the MHV-A59 3C-like proteinase from the flanking hydrophobic domains requires membranes

The replicase gene of the coronavirus MHV-A59 encodes a serine-like proteinase similar to the 3C proteinases of picornaviruses. This proteinase domain is flanked on both sides by hydrophobic, potentially membrane-spanning, regions. Cell-free expression of a plasmid encoding only the 3C-like proteinase (3CLpro) resulted in the synthesis of a 29-kDa protein that was specifically recognized by an antibody directed against the carboxy-terminal region of the proteinase. A protein of identical mobility was detected in MHV-A59-infected cell lysates. In vitro expression of a plasmid encoding the 3CLpro and portions of the two flanking hydrophobic regions resulted in inefficient processing of the 29-kDa protein. However, the efficiency of this processing event was enhanced by the addition of canine pancreatic microsomes to the translation reaction, or removal of one of the flanking hydrophobic domains. Proteolysis was inhibited in the presence of N-ethylmaleimide (NEM) or by mutagenesis of the catalytic cysteine residue of the proteinase, indicating that the 3CLpro is responsible for its autoproteolytic cleavage from the flanking domains. Microsomal membranes were unable to enhance the trans processing of a precursor containing the inactive proteinase domain and both hydrophobic regions by a recombinant 3CLpro expressed from Escherichia coli. Membrane association assays demonstrated that the 29-kDa 3CLpro was present in the soluble fraction of the reticulocyte lysates, while polypeptides containing the hydrophobic domains associated with the membrane pelletes. With the help of a viral epitope tag, we identified a 22-kDa membrane-associated polypeptide as the proteolytic product containing the amino-terminal hydrophobic domain.