Search PubMed⌕ Search

Biomedical subjects

J Stein

Publications and source records attributed to J Stein.

At least 361 records · Page 20Linked to original sources
PubMed1987

Proximal and distal regulatory elements that influence in vivo expression of a cell cycle-dependent human H4 histone gene.

We have examined the sequences required in vivo to promote transcription of a cell cycle-regulated human H4 histone gene. Deletion mutants of the 5' flanking region were assayed in mouse cells or fused with the chloramphenicol acetyltransferase (CAT) gene for assay in HeLa cells. The functional limits of the regulatory sequences were shown to extend at least 6.5 kilobases (kb) upstream. Sequences sufficient for correctly initiated transcription were found in the 70 base pairs (bp) immediately 5' to the cap site. A proximal element located 200-400 bp upstream increased the level of transcription several times above the basal level, although not to maximal levels. Maximal levels of expression were achieved with 6.5 kb of 5' flanking sequence adjacent to the proximal promoter sequences or when a distal enhancer element with both position- and orientation-independent function was moved proximal to the promoter. Our results indicate that a series of 5' cis-acting sequences are functionally related to the fidelity and level of expression of this human H4 histone gene.

Animals↗
PubMed1987

Targeting of a chimeric human histone fusion mRNA to membrane-bound polysomes in HeLa cells.

The subcellular location of histone mRNA-containing polysomes may play a key role in the posttranscriptional events that mediate histone mRNA turnover following inhibition of DNA synthesis. Previously, it has been shown that histone mRNA is found primarily on free polysomes that are associated with the cytoskeleton. We report here the construction of an Escherichia coli pBR322 beta-lactamase signal peptide-human H3 histone fusion gene. The fusion transcript is targeted to membrane-bound polysomes and remains stable following interruption of DNA replication. Relocating mRNA within the cell may provide a procedure for studying the posttranscriptional regulation of gene expression.

Cell Membrane↗
PubMed1987

Comparison of an agar slide blood culture device with Bactec 6B for the detection of bacteremia.

Each of 1,018 blood culture specimens was inoculated into Bactec 6B (Johnston Laboratories, Towson, MD) and a biphasic blood culture system that incorporates internal removable agar dip slides (Hylab). Ninety clinically significant pathogens were recovered: 66 from both systems, 14 from Bactec only, and 10 from Hylab only. The mean incubation times to positive of the two systems did not differ when data were examined for gram-negative bacilli, gram-positive cocci, total isolates, and contaminants (P greater than 0.05). Contamination rates were also comparable: Bactec 5.4%, Hylab 7.3% (P greater than 0.05). The Hylab system may offer a practical alternative to Bactec 6B.

Agar↗
PubMed1987

Monoclonal antibodies to the extracellular glucosyltransferases from Streptococcus sobrinus 6715.

Murine monoclonal antibodies (MAbs) were raised against the glucosyltransferases (GTFs) of Streptococcus sobrinus 6715. The antibody panels included MAbs raised against the primer-independent, soluble product enzyme (GTF-Si) which did not cross-react with other GTFs, as well as MAbs raised against the primer-dependent, soluble product enzyme (GTF-Sd) which recognized both GTF-Si and GTF-Sd, thus indicating that these catalytically distinct enzymes share epitopes. MAbs raised against GTF-I recognized several forms of GTF-I and did not cross-react with the GTF-S enzymes. None of the MAbs recognized the major glucan-binding protein of S. sobrinus. Two MAbs inhibited glucan synthesis, one blocking primer synthesis by GTF-Si by 89% and the second inhibiting that by GTF-I by 92%.

Antibodies, Bacterial↗
PubMed1987

C-reactive protein in the assessment of disease activity in juvenile rheumatoid arthritis and juvenile spondyloarthritis.

Disease activity in 31 children with JRA and 12 with JSA was investigated clinically and by serial measurements of serum CRP and ESR over a one-year period. Prior mean duration of disease was 4.3 years. There was a significant correlation of CRP with ESR and both parameters correlated significantly with clinical disease activity. CRP concentrations and ESR in active disease were significantly higher than in moderately active and inactive disease, though neither parameter showed any significant difference between moderately active and inactive disease. Clinical scoring was more sensitive in detection of moderate disease activity than were CRP and ESR. However, in systemic JRA without articular involvement, laboratory parameters were more useful for assessing disease activity.

Adolescent↗
PubMed1986

Histone gene stability during cellular senescence.

The extent to which human histone gene organization is conserved during the in vitro lifespan of human diploid fibroblast-like cells was determined by comparing the restriction patterns of a human H4 and an H3 histone gene from cells of various in vitro ages. No age related change in the organization of these two genes was detected.

Aging↗
PubMed1986

Sequence and organization of genes encoding the human 27 kDa heat shock protein.

The 27 kDa human heat shock protein (hsp27) is encoded by a gene family of 4 members. Two genomic fragments hybridizing to cDNA encoding hsp27 have been isolated, characterized, and sequenced. One clone is a member of a cluster of three genes linked within a 14-18 kb region of the genome and encodes a transcript interrupted by two intervening sequences. A single open reading frame encodes a polypeptide of 22,300 deduced molecular weight. The 5' flanking region contains two transcription start sites and sequences homologous to the Drosophila consensus heat inducible control element. Induction of both potential transcripts follows heat shock in vivo. Accurate heat inducible transcription occurs at both start sites after injection into Xenopus oocytes. The second genomic clone is a processed pseudogene lacking promoter elements and is unlinked with the other members of the hsp27 gene family. The amino acid sequence of human hsp27 shows striking homology with mammalian alpha crystallin, and contains a region towards the carboxy terminus which shares homology with the small hsp of Drosophila and other organisms.

Amino Acid Sequence↗
PubMed1986

Daily reproducibility of electrophysiologic test results in malignant ventricular arrhythmia.

The reproducibility of electrophysiologic testing on successive days was assessed in the absence of antiarrhythmic drug treatment. Forty-two patients, 17 with compromising ventricular tachycardia and 25 with ventricular fibrillation unrelated to myocardial infarction, underwent 2 baseline studies. During the first electrophysiologic study, arrhythmia was induced in 32 of 42 patients (76%); however, during the second study a similar endpoint was reached in only 22 patients (52%) (chi 2 = 5.12, p less than 0.05). Only 18 of the 32 patients (56%) with induced arrhythmia during the first study had a reproducible result. Reproducibility was not related to presence of coronary artery disease, nature of presenting arrhythmia, or endpoint achieved (sustained or nonsustained ventricular tachycardia) during electrophysiologic study. Hence, reproducibility of endpoint during electrophysiologic investigation should be ascertained in each patient before initiating serial drug studies.

Adolescent↗
PubMed1986

Localization of human histone gene transcripts predominantly in the nonmatrix nuclear fraction.

Using S1 nuclease protection assays, we have examined the representation of cell cycle-dependent H4 histone RNAs in the nuclear matrix and nonmatrix nuclear fractions of human cells. Cytoplasmic and nuclear fractions were prepared from exponentially growing HeLa S3 cells by double detergent (sodium deoxycholate and NP40) lysis. The nuclear matrix and nonmatrix nuclear fractions were then prepared by digestion of nuclei with RNase-free DNase I and subsequent high-salt [0.4 M (NH4)2SO4] extraction. Subcellular fractions were characterized by 1) DNA, RNA, and protein composition; 2) electrophoretic analysis of the proteins in each fraction; 3) the representation of 45S ribosomal RNA precursors and processed 18S and 28S ribosomal RNAs; and 4) the presence of mitochondrial RNAs. In contrast to ribosomal and messenger RNA precursors, which are largely associated with the nuclear matrix, the human H4 histone RNAs in the nucleus were found predominantly in the nonmatrix nuclear fraction. The presence of H4 histone RNA in the nonmatrix nuclear fraction appeared to be coupled to DNA replication, since inhibition of DNA synthesis by hydroxyurea resulted in a loss of histone RNA from the nucleus. Our results suggest either that the association of histone RNAs with the nuclear matrix is very transient or that posttranscriptional modifications of the rapidly processed histone gene transcripts do not involve the nuclear matrix.

Cell Cycle↗
PubMed1986

Serial circulating immune complex values and development of metastatic disease in breast cancer and malignant melanoma patients.

A polyethylene glycol precipitation technique was used to determine the levels of circulating immune complexes (CIC) in breast cancer and melanoma patients. All patients in the study had undergone surgery and were free of distant metastatic disease. CIC were measured at two to four time intervals, of 3 to 6 months each, over an average follow-up period of 13.5 months (range 7-20 months). In both groups of patients, metastatic disease developed with a higher frequency in patients who had undetectable CIC levels throughout the follow-up period or had become negative at the time metastases were discovered.

Antigen-Antibody Complex↗
PubMed1986

Role of the RecF gene product in UV mutagenesis of lambda phage.

E. coli recF mutants have a greatly reduced capacity for Weigle mutagenesis of ultraviolet light-irradiated lambda phage. A recF 332::Tn3 mutation was introduced into an E. coli recA441 lexA51 strain which constitutively expresses SOS functions. Weigle mutagenesis of phage lambda could occur in the resulting strain in the absence of host cell irradiation, and was increased when the recA441 (tif) allele was activated by increased temperature and excess adenine. The inability of recF strains to support Weigle mutagenesis can therefore be ascribed to a defect in expression of SOS functions after irradiation.

Bacterial Proteins↗
PubMed1986

Pseudo-widening of cranial sutures as a feature of long-term prostaglandin E1 therapy.

Disturbance of desmogenous ossification of the skull is an extremely rare complication of long-term prostaglandin treatment. This report describes a newborn with pulmonary atresia, ventricular septal defect and ductus-dependent pulmonary blood flow in whom administration of prostaglandin E1 (PGE1) over a period of 96 days produced uncommon clinical and radiologic findings.

Cranial Sutures↗