Quantitative structure-activity relationships (QSAR) of trimedlure isomers.

Trimedlure (tert-butyl 4- and 5-chloro-cis- andtrans-2-methylcyclohexane-1-carboxylate), a mixture of eight isomers, is used as an attractant for detecting and monitoring the male Mediterranean fruit fly. This paper reports the quantitative structure-activity relationship (QSAR), via CHEMX, of the eight purified isomers (racemic mixtures) of trimedlure. The relationship between structure and attractiveness is demonstrated by utilizing male medfly field catch on day 0 of the individual isomers vs.

Contribution of O6-alkylguanine and N-alkylpurines to the formation of sister chromatid exchanges, chromosomal aberrations, and gene mutations: new insights gained from studies of genetically engineered mammalian cell lines.

O6-methyl- and O6-ethylguanine are the major premutagenic and precarcinogenic lesions induced in DNA by monofunctional alkylating agents, albeit formed in minor amounts. The involvement of these lesions in SCE and aberration formation is less clear. We have analyzed the contribution of O6-alkylguanine to SCE and aberration formation, as well as its toxic and point mutation inducing effect in transgenic Chinese hamster ovary (CHO) cell lines that express variable amounts of human O6-methylguanine-DNA methyltransferase (MGMT).

Stress factors affecting expression of O6-methylguanine-DNA methyltransferase mRNA in rat hepatoma cells.

O6-Methylguanine-DNA methyltransferase (MGMT) is decisively involved in protecting mammalian cells against genotoxic effects of alkylating carcinogens. We analysed regulation of MGMT expression after exposing rat hepatoma H4IIE cells to various 'stress' factors. Treatments that damage DNA such as alkylation, hydrogen peroxide, ultraviolet or X-ray exposure, as well as restriction enzymes introduced into cells by electroporation or arrest of replication by hydroxyurea significantly induced MGMT mRNA (2.

Evidence of seasonal eggs in Anopheles punctipennis (Diptera: Culicidae).

Anopheles punctipennis (Say), collected in October from resting sites in Illinois, deposited two morphologically distinct types of egg batches. One type was similar to the seasonal "winter" egg of Anopheles walkeri Theobald, with an extensive exochorion that covered all except the tip of the egg. Laboratory rearing of isofemale lines, under two different light-dark and temperature cycles, demonstrated that both types of eggs were intraspecific variants.

Genomic differences between O6-methylguanine-DNA methyltransferase proficient (Mex+) and deficient (Mex-) cell lines: possible role of genetic and epigenetic changes in conversion of Mex+ into Mex-.

Cell lines that possess O6-methylguanine-DNA methyltransferase (MGMT) repair activity (Mex+ phenotype) or are deficient for MGMT (Mex-) are compared at genomic level. It is shown that 1) 208F rat cells do not contain the MGMT gene, as detected by Southern blot hybridization. 2) Mex- HeLa MR and CHO-9 cells express very low amounts of MGMT mRNA, as detected by PCR.

The check-up of reproductive health and genetic counseling.

The Hungarian Family Planning Program was a feasibility study on combining methods of periconceptional care. The first step was the check-up of reproductive health, including family history of the couples, case history of females, pre-pregnancy examination (vaginal and cervical smears), and the measurement of basal body temperature, sperm examination, psycho-sexual exploration and exclusion of some risk factors. This preconception screening program was carried out by graduate trainee nurses to identify those participants secondary health services.

Transfection and expression of human O6-methylguanine-DNA methyltransferase (MGMT) cDNA in Chinese hamster cells: the role of MGMT in protection against the genotoxic effects of alkylating agents.

O6-Methylguanine-DNA methyltransferase (MGMT) is responsible for removal of O6-alkylguanine from DNA induced by alkylating mutagens/carcinogens. To analyze the involvement of O6-alkylguanine in the generation and MGMT in avoidance of various genotoxic effects of alkylating agents, we transfected Chinese hamster ovary (CHO) cells that lack MGMT activity with human MGMT cDNA cloned into a mammalian expression vector (pSV2MGMT). A high proportion (60-80%) of transfectants selected for a cotransfected neo gene survived treatment with high doses of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and N-hydroxyethyl-N-chloroethylnitrosourea (HeCNU).

Inducibility of the DNA repair gene encoding O6-methylguanine-DNA methyltransferase in mammalian cells by DNA-damaging treatments.

The inducibility of the mammalian O6-methylguanine-DNA methyltransferase (MGMT) gene encoding the MGMT protein (EC 2.1.1.

Diagnostic characterization of Anopheles freeborni and An. hermsi by hybrid crosses, frequencies of polytene X chromosomes and rDNA restriction enzyme fragments.

A polytene chromosome analysis was prepared from Anopheles freeborni collected from 25 locations in north and central California, and parts of Washington and Oregon. The X chromosome banding pattern, thought previously to be specific to An. hermsi, was common in mosquitoes collected from foothill regions in California, and in all samples from Washington and Oregon.

Accuracy of blood glucose estimates in adolescents with diabetes mellitus.

Although self-monitoring of blood glucose (SMBG) is an integral part of the daily self-care regimen for the effective management of insulin-dependent diabetes mellitus (IDDM), compliance with this task remains a significant problem, particularly for adolescents. Research should be focused on identifying other management approaches which may supplement SMBG. One potential approach involves placing greater reliance on the patient's own ability to estimate glucose levels.

AIDS education: the Rhode Island experience.

AIDS prevention, by public school education, is designed to change knowledge, attitudes, and future behavior. This study evaluated the impact of a state-mandated educational program on a sample of 2709 adolescents. Changes from pre to posttest were evaluated using standardized change scores and comparisons between the experimental and a delayed education control group were made.

Identification of human genes involved in repair and tolerance of DNA damage.

An overview is presented on strategies of cloning mammalian DNA repair genes. Complementation of human and rodent repair defects and mutagen hypersensitivities by chromosome and DNA mediated gene transfer and mRNA microinjection is described, and the features of the cloned human DNA repair genes are summarized. It is shown that transfection of repair deficient cell lines with cloned bacterial and human genes may give rise to protection from the genotoxic effects of mutagens.

[Validity of clinico-chemical and hematologic findings in the elderly--results of a randomized study].

The distinction between age-related and pathological laboratory findings in elderly is most important to diagnosis and treatment of disease. 111 pensioners (77 females, 34 men) are investigated. Pathological laboratory findings are more frequently than expected.

Complementation of N-hydroxyethyl-N-chloroethylnitrosourea hypersensitivity of Mex- cells by microinjection of mRNA from Mex+ cells.

Chinese hamster ovary (CHO-9) and HeLa MR cells lack detectable amounts of O6-alkylguanine DNA alkyltransferase (phenotypically Mex-) and are hypersensitive to the toxic effect of N-hydroxyethyl-N-chloroethylnitrosourea (HeCNU), as compared to Mex+ derivatives. Microinjection of size-fractionated polyA+ mRNA extracted from HeLa S3 (Mex+) into CHO-9 and HeLa MR cells, or from ataxia telangiectasia (Mex+) into HeLa MR cells, gave rise to an increase in survival following treatment with toxic doses of HeCNU. Transient complementation of the Mex- phenotype was achieved with an RNA population 0.

Casein kinase II is elevated in solid human tumours and rapidly proliferating non-neoplastic tissue.

Protein kinase CKII (i.e. casein kinase II, CKII, NII) is expressed at a higher level in rapidly proliferating tissues and in solid human tumours (e.

Accuracy of symptom perception in childhood asthma.

Children's reports of their asthma symptoms are used as important data in the assessment and management of pediatric asthma, but little is known about the accuracy of such reports. Children's subjective perception of the level of asthma symptoms was correlated with peak expiratory flow rate measures on average of 34 observations for 37 children with asthma. Subjective/objective correlations for a given child varied from 0.

Reimer-Tiemann adducts as potential insect antifeedant agents Reviewing the structure-activity relationship theory of the antifeedant, warburganal.

Structure-activity relationships of naturally occurring enedials with antifeedant activity againstSpodoptera species have been extended via the synthesis and bioassay of a series of Reimer-Tiemann adducts. The activities attributed to the different chemical structures of these and other analogs interacting with the chemoreceptor site have been observed; a three-pronged mode of substrate binding via aromatic pyrrole formation, Michael addition of free sulfhydryl moieties, and van der Waals interactions of the A ring has been postulated to account for these observations.

The impact of AIDS education on junior and senior high school students. A pilot study.

Prevention, through school-based education campaigns, has been suggested as a response to the AIDS crisis although the impact of such education is unproven. The seventh and tenth grade classes (n = 313) in one Rhode Island school district were surveyed regarding AIDS knowledge, attitudes, and coping skills before and after a two-session educational program. Following instruction, students reported more knowledge, greater tolerance of AIDS patients, and more hesitancy toward high-risk behaviors, but the changes were modest.