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Biomedical subjects

J B Lewis

Publications and source records attributed to J B Lewis.

105 records · Page 6Linked to original sources
PubMed1974

Cell-free synthesis of adenovirus 2 proteins programmed by fractionated messenger RNA: a comparison of polypeptide products and messenger RNA lengths.

Cytoplasmic RNA extracted from human tissue culture cells infected with adenovirus type 2 was used to program protein synthesis in a cell-free system derived from mammalian cells. Analysis of the protein product by polyacrylamide gel electrophoresis revealed ten adenovirus-specific polypeptides. Five of these were further identified by analysis of tryptic peptides. Translation of RNA fractionated by sedimentation through sucrose gradients containing formamide demonstrated seven size classes of RNA, each of which programmed the synthesis of only one or two virus-specific polypeptides. Six of the virus-specific polypeptides were translated from RNAs much larger than expected for the size of the polypeptide.

Adenoviridae↗
PubMed1968

The oxidation of aminoacetone by a species of Arthrobacter.

1. A micro-organism similar to Arthrobacter globiformis has been isolated from sewage by elective growth on a medium containing l-threonine as sole source of carbon and nitrogen. 2. Washed cell suspensions of the organism catalyse the complete disappearance of aminoacetone from the medium and its almost complete oxidation. 3. In the presence of iodoacetate, aminoacetone disappearance is accompanied by the accumulation of methylglyoxal, about 70% of the aminoacetone removed being accounted for in this way. 4. It is suggested that the conversion of aminoacetone into methylglyoxal is catalysed by an amine oxidase.

Acetone↗
PubMedDate not supplied

Should nurses be required to administer care to patients with AIDS? Students respond.

A total of 40 baccalaureate nursing students were assigned to write a paper that expressed their opinions about providing care to patients with acquired immunodeficiency syndrome (AIDS) and to give the rationale used to support their views. Although 75% of the students believed that nurses should provide care to patients with AIDS, 25% expressed either negative or ambivalent feelings about providing such care. Moreover, many of the same rationales were offered to substantiate all three attitudes, emphasizing the need for definitive guidelines for decision making.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

What parents should know about estrogen-like compounds in dental materials.

The use of pit and fissure sealants has been reported to increase exposure to xenoestrogens. Because these estrogen-mimics are suspected of having many deleterious effects in animals, and perhaps humans, several types of studies were undertaken by our Biocompatibility Group. We confirmed that bisphenol A (BPA) and bisphenol A dimethacrylate (BPA-DM) have proliferative effects in cells with high levels of estrogen receptors. However, BPA was not detected by our group in American-made sealants, and BPA-DM was detectable in only a few. In addition, the surface layer of the sealant can be treated to reduce the possibility of unpolymerized BPA-DM being left on the tooth. We believe it is important to reassure parents that their children are less likely to be exposed to BPA from sealants than from the ingestion of soft drinks or canned food.

Animals↗
PubMedDate not supplied

Chemopreventive effects of green tea polyphenols correlate with reversible induction of p57 expression.

Green tea polyphenols are known to induce apoptosis in certain types of tumor cells. However, the mechanism(s) that enables normal cells to evade the apoptotic effect is still not understood. In this study, Western blot analysis combined with cycloheximide treatment was used to examine the effects of green tea polyphenols on the expression levels of p57, a cyclin-dependent kinase and apoptosis inhibitor, in normal human keratinocytes and in the oral carcinoma cell lines SCC25 and OSC2. The results showed that the most potent green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), induced p57 in normal keratinocytes in a dosage- and time-dependent manner, while the levels of p57 protein in oral carcinoma cells were unaltered. The differential response in p57 induction was consistent with the apoptosis status detected by annexin V assay. The data suggest that the chemopreventive effects of green tea polyphenols may involve p57-mediated cell cycle regulation in normal epithelial cells.

Aged↗