Mining MEDLINE for implicit links between dietary substances and diseases.

Motivation: Text mining systems aim at knowledge discovery from text collections. This work presents our text mining algorithm and demonstrates its use to uncover information that could form the basis of new hypotheses. In particular, we use it to discover novel uses for Curcuma longa, a dietary substance, which is highly regarded for its therapeutic properties in Asia.

Semantic relations asserting the etiology of genetic diseases.

Considerable research is being directed at extracting molecular biology information from text. Particularly challenging in this regard is to identify relations between entities, such as protein-protein interactions or molecular pathways. In this paper we present a natural language processing method for extracting causal relations between genetic phenomena and diseases.

NLP-based information extraction for managing the molecular biology literature.

We present research aimed at devising a tool for using natural language processing to identify and extract biomedical information from text for the purpose of assisting researchers in molecular biology manage large amounts of information. A pilot project based on the molecular genetics of diabetes demonstrates our ability to explore the interaction of genomic phenomena and clinical findings. We suggest the cooperation of this extracted information with systems for clustering text and constructing labeled networks of data.

Antiretroviral therapy effects on genetic and morphologic end points in lymphocytes and sperm of men with human immunodeficiency virus infection.

Many human immunodeficiency virus (HIV)-infected persons receive prolonged treatment with DNA-reactive antiretroviral drugs. A prospective study was conducted of 26 HIV-infected men who provided samples before treatment and at multiple times after beginning treatment, to investigate effects of antiretrovirals on lymphocyte and sperm chromosomes and semen quality. Several antiretroviral regimens, all including a nucleoside component, were used.

Rat pleural mesothelial cells adapted to serum-free medium as a model for the study of growth factor effects.

Mesothelial cells are the putative progenitors of mesotheliomas and cell lines have been used as tools to study the responses of these cells to various stimuli, including growth factors. The present study was undertaken to develop a rat mesothelial cell line capable of sustained growth under serum-free conditions with the object of avoiding the possible confounding effects of undefined serum components. Responses of mesothelial cells to epidermal growth factor were shown to differ under serum-free versus low-serum culture conditions.

Acute exposure of female hamsters to carbendazim (MBC) during meiosis results in aneuploid oocytes with subsequent arrest of embryonic cleavage and implantation.

A single oral dose of the fungicide and microtubule poison, MBC, administered to female hamsters at proestrus, results in infertility and early pregnancy loss (1). To characterize the site and mode of action of this effect, direct assessments of oocyte chromosomes, fertilization, and preimplantation embryo development were made. Female hamsters were given a single dose of MBC (1,000 mg/kg) on the afternoon of proestrus (to coincide with meiotic maturation of the oocytes) and either killed shortly after ovulation (day 1) to recover oocytes, or bred and killed on gestation day (gd) 1 to 5 of pregnancy to assess fertilization and preimplantation embryo development and enumerate early implantation sites.

Cytogenetic analysis of malignant skin tumors induced in chemically treated TG-AC transgenic mice.

TG.AC mice (which carry a v-Ha-ras transgene) rapidly develop papillomas in response to 12-O-tetradecanoylphorbol-13-acetate (TPA). Approximately 30% of the papillomas are associated with subsequent development of malignancies.

Nutritional folate-deficiency in Chinese hamster ovary cells. Chromosomal abnormalities associated with perturbations in nucleic acid precursors.

Folate deficiency is known to induce chromosomal abnormalities. We used a nutritionally folate-deficient Chinese hamster ovary (CHO) cell culture system to examine modulation of chromosome damage by purine or pyrimidine supplementation. The cells were cultured in folate-deficient (Fol-) medium or Fol- medium supplemented with thymidine (dT) or hypoxanthine (Hx) until population growth arrest.

Induction of DNA strand breaks in cultured rat embryo cells by crocidolite asbestos as assessed by nick translation.

Asbestos, a proven carcinogen, is reported to have no genotoxic effects. We hypothesized, however, in light of its clastogenic effects that one mechanism by which asbestos induces cell transformation and tumorigenesis involves the induction of DNA strand scission. Cultured rat embryo cells were exposed to low concentrations of International Union Against Cancer crocidolite and examined at intervals ranging from 2 to 48 h.

Chromosomal translocations with specific breakpoints in asbestos-induced rat mesotheliomas.

Cytogenetic analysis was conducted on cells of 15 rat mesotheliomas induced in rats by the i.p. inoculation of crocidolite or chrysotile asbestos.

Molecular analyses of in vivo hypoxanthine-guanine phosphoribosyltransferase mutations in human T-lymphocytes: II. Demonstration of a clonal amplification of hprt mutant T-lymphocytes in vivo.

Recent molecular analysis of in vivo-derived hprt mutant T-lymphocytes cloned from human blood show that mutants occurring at the normal frequency (approximately 5 X 10(-6) in healthy young individuals generally represent independent hprt mutations. Here we report that in an individual with a high mutant frequency (86-620 X 10(-6],92% (61/66) of the mutant clones are descendents of an original mature T-cell precursor that has undergone in vivo clonal expansion. Therefore, these mutants could represent as few as one original hprt mutation.

The creeping vole, Microtus oregoni: karyotype and sex-chromosome differences between two geographical populations.

The G-banded karyotype of the creeping vole, Microtus oregoni, prepared from animals trapped in Oregon and Washington, is presented. The two populations had similar autosomal banding patterns but exhibited striking differences in their sex chromosomes. The X chromosome of voles captured in Oregon was 39% longer than that of voles trapped in Washington.

Characteristics of tumors and tumor cells cultured from experimental asbestos-induced mesotheliomas in rats.

Mesotheliomas developed in rats in the abdominal cavity 6-23 months after peritoneal introduction of chrysotile and crocidolite asbestos. The tumors were strikingly similar to those occurring in man both with regard to histologic features and growth patterns. The authors have cultured cells from these tumors and established epithelial lines with a variety of karyologic features and doubling times shorter than those of normal mesothelial cells.

Incidence of chromosome aberrations in mammalian sperm stained with Hoechst 33342 and UV-laser irradiated during flow sorting.

The separation of two sperm populations is possible using the technique of flow sorting, provided that a significant difference exists in the DNA content of X- and Y-bearing sperm. In order to ascertain whether or not chromosome damage was induced in sorted sperm, chromosome preparations were made from isolated sperm that had been microinjected into hamster eggs. While egg chromosomes exhibited a low frequency of chromosome aberrations, ranging from 4 to 7%, a large proportion of sperm cells exhibited chromosome damage.

Down syndrome in two siblings with 47,XY,+21 and 46,XY/46,XY,-21,+t(21q;21q).

This is the first report in the literature of siblings affected with Down syndrome; one sibling had a nondisjunction of chromosome 21 and the other a (21q;21q) translocation.

The ordered arrangement of chromosomes in the Chinese hamster spermatocyte nucleus.

The question of chromosome distribution in the mammalian nucleus is addressed, and data are provided in support of the ordered arrangement of chromosomes in the Chinese hamster spermatocyte. Testicular cells were dispersed and air-dried without prior fixation, then stained and karyotyped. The position of chromosome telomeres in 217 pachytene spermatocytes was determined in relation to four concentric rings which equally divided the nuclear area.

Ultrastructural changes induced by steroids and gonadotropins in cultured rat Sertoli cells.

Testicular cells readily grew in cultures of seminiferous tubule fragments derived from adult rat testes. They formed confluent monolayers and continued to grow through four passages. The majority of cells had ultrastructural features characteristic of Sertoli cells.

Gonadotrophin-induced reinitiation of meiosis in testes of oestradiol-treated prepubertal rats.

Male rats injected with 50 micrograms oestradiol dipropionate every 5 days from birth were given daily injections of 20 i.u. PMSG from 20 to 29 days of age.

Sequential development and tissue organization in whole mouse embryos cultured from blastocyst to early somite stage.

The development of mouse embryos in culture from the implantation to the head-fold stage was sequentially examined. Our goal was to compare the morphology of embryos grown in vitro to those developed in vivo, published in standard texts, and to delineate the stages involved in the process of tissue differentiation and organization. Mouse blastocysts (stage 6) were collected at 3.

Changes in S-phase associated with differentiation of mouse embryos in culture from blastocyst to early somite stage.

Mouse embryos, cultured for 8 days from the blastocyst (stage 5 of Theiler, 1972) to the 10--12 somite stage (stage 13) were labeled at daily intervals with 5 muCi/ml 3H-thymidine for 2 h, sectioned, and processed for autoradiography. The frequency of labeled cells, as well as the intensity of labeling, exhibited a progressive decline during the period of growth of embryos in culture. Endoderm and ectoderm cells were characterized by significant differences in the labelling index and the rate of DNA syntheses.

Analysis of the progression of meiosis in dispersed rat testicular cells by flow cytofluorometry.

Initiation and progression of meiosis was followed in dispersed rat testicular cells by flow cytofluorometry and cytology. The DNA content of dissociated testicular cells of rats 6--30 days old, killed at daily intervals, was analysed by flow cytofluorometry using propidium iodide as a DNA-specific and quantitative fluorochrome. Testicular cells of a 6-day-old rat showed one peak of fluorescence.