Apoptosis, bcl2 expression, and cell cycle analyses in nickel(II)-treated normal rat kidney cells

Nickel compounds are carcinogenic to human and are potent inducers of kidney and lung tumors in experimental animals. In this study, the effects of nickel(II) acetate on apoptosis, cell cycle and bcl2 expression in normal rat kidney (NRK- 52E) cells were investigated. Nickel(II) induced apoptosis in NRK-52E cells as demonstrated by DNA laddering. Apparent DNA laddering was observed in cells treated with 480 microM for 48 hr. In the flow cytometric analysis using propidium iodide fluorescence, an increase of cell proportion in G2/M phase was shown in cells exposed to at least 320 microM of nickel(II) acetate, from 7.7% for 0 microM of nickel(II) to 16.5% for 480 microM of nickel(II) acetate. Induction of apoptotic cell death by nickel(II) was accompanied by reduction of bcl2 protein expression, while the level of p53 protein was not changed. Taken together, our data indicate that nickel(II)-induced apoptosis in NRK-52E cells is accompanied by G2/M cell cycle arrest, regardless of p53 function, and that bcl2-mediated signaling pathway may be involved in positive regulation of nickel(II)-induced apoptotic cell death in NRK-52E cells.

Body Weight, Body Mass Index, Plasma Leptin, Insulin and Fasting Glucose Level in Schizophrenic Patients Receiving Olanzapine / 신경정신의학

OBJECTIVE: The aim this study was to investigate possible mechanisms behind olanzapine-associated weight gain. METHOD: Thirteen psychiatric inpatients (all meeting DSM-IV criteria for schizophrenia or schizophreniform disorder) receiving olanzapine in Soonchunhyang university Chun-an hospital were studied. Body weight, plasma leptin, insulin and fasting glucose levels were measured five-times over 6 weeks. Body mass index (BMI) was calculated. RESULT: At the end of sixth week, body weight, BMI, plasma leptin, insulin and fasting glucose levels were significantly increased from baseline. Both insulin and leptin plasma levels were significantly increased from baseline at the end of the sixth week of treatment. Both body weight and BMI were significantly increased from baseline at the end of the first week, the fourth week and sixth week, respectively. Fasting glucose was significantly increased from baseline at the end of the fourth week and sixth week, respectively. Between baseline and sixth week, the body weight, BMI, plasma leptin and fasting glucose levels were significantly correlated to insulin level. There was a tendency toward a correlation between BMI and leptin level, whereas no correlation was found between body weight and leptin. CONCLUSION: Olanzapine treatment was associated with weight gain and elevated level of leptin, insulin and fasting glucose. Elevated insulin levels and hyperleptinemia may be mechanisms behind olanzapine-induced weight gain.

Characterization of aberrant FHIT transcripts in gastric adenocarcinomas

Aberrant transcripts of FHIT (fragile histidine triad) have been reported in several types of primary tumors and cell lines, including gastric carcinoma. The role of these aberrant transcripts in tumorigenesis is not clear yet. Forty-eight aberrant-sized FHIT transcripts with various lengths and number in 35 cases of gastric adenocarcinomas were further characterized. Aberrant transcripts, with deletions and/or insertions, were frequently observed in 20 cases of tumors. Sequence analysis demonstrated that different types of aberrant transcripts used normal splice sites but skipped exons, contained the inserts with the part of intron 5 sequences, or used the FHIT cDNA sequence 179-180 as a cryptic splice acceptor site. Most of aberrant transcripts lacked exon 5 and were presumably non-functional as the translation initiation codon is located in exon 5. Additionally, other transcripts, indicative of additional splice processing, either deletions or insertions, were expressed in several tumors. Taken together, our data indicate that the FHIT gene expression is frequently altered in gastric adenocarcinomas by aberrant splicing, and suggest that different types of aberrant transcripts may result during the multi-step splice processing.

Nickel (II)-induced apoptosis and G2/M enrichment

Treatment with certain DNA-damaging agents induce a complex cellular response comprising pertubation of cell cycle progression and/or apoptosis on proliferating mammalian cells. Our studies were focused on the cellular effects of nickel (II) acetate, DNA-damaging agent, on Chinese hamster ovary (CHO) cells. Fragmented DNAs were examined by agarose gel electrophoresis and cell cycle was determined by DNA flow cytometry using propidium iodide fluorescence. Apparent DNA laddering was observed in cells treated with 240 microM nickel (II) and increased with a concentration-dependent manner. Treatment of nickel (II) acetate resulted in apoptosis which was accompanied by G2/M cell accumulation. Proportion of CHO cells in G2/M phase was also significantly increased in cells exposed to at least 480 microM nickel (II) from 57.7% of cells in the G0/G1 phase, 34.7% in the S phase, and 7.6% in the G2/M1 phase for 0 microM nickel (II), to 58.6%, 14.5%, and 26.9% for 640 microM nickel (II). These findings suggest that nickel (II) can modulate cellular response through some common effectors involving in both apoptotic and cell cycle regulatory pathways.

Monoclonal antibody production and characterization for the measurement of plasma high density lipoprotein

We prepared two monoclonal antibodies-A-I30 and A-I4 to HDL apo A-I-with the ultimate goals of expressing and overproducing the valuable immunodiagnostic single chain Fv by phage display libraries in E, coli. Monoclonal antibodies were produced by immunizing mice with apolipoprotein A-I, and purified from ascitic fluid by affinity chromatography on a Protein A Sepharose CL-4B column. The specificity of A-I30 and A-I4 was confirmed by ELISA and Western blotting. The dissociation constants(Kd) of antigen-antibody complex obtained by enzyme linked immunosorbent assay(ELISA) method were 2.25 x 10(-8) M for A-I30 and 2.15 x 10(-8) M for A-I4. The experimental values of Kd are shown to be close to those obtained by immunoprecipitation of the radiolabeled antigen. From the above results, it was shown that A-I30 and A-I4 could be provided as excellent reagents for the determination of plasma HDL concentrations in clinical specimens using ELISA.

Perceptions of Teachers to the Specific Behavioral Objectives in Basic Medical Sciences and its Implementation in Teaching Situation / 한국의학교육

The purpose of this study was to investigate the perceptions of teachers to the learning objectives (specific behavioral objectives, SBO) of their own specialty subjects at real educational situation and also to examine how and when teachers use the SBO. A questionnaire was constructed through a series of discussion at the task force meetings. Opinions from the members were gathered and a list of 21 items of question was generated and finally rephrased each question item to make 20 closed-type and 1 open-type questionnaire. The questionnaires were administered to all the faculties who have been engaged in teaching a subject of basic medical sciences. Although the response rate of the questionnaire was 43%, fairly even distribution of rank proportion of responded faculties were analyzed that could give strong convince of acceptable level of the results. The analysis showed that most of the faculties have fairly high perceptions to the necessity of SBO in teaching situations, while only 25% of thorn administered the SBO to their students. About 33% of the responded faculties construct SBO individually, and 25% have joined to a group work in their own department. A booklet, "Specific Behavioral Objectives in Basic Medical Sciences", has been well known and 85% of them used the booklet as a reference to make their own SBO. 65% of the faculties keep the booklets and the remaining groups answered that they don't have it although some of them have been seen it before.