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Biomedical subjects

R Clifford

Publications and source records attributed to R Clifford.

31 records · Page 2Linked to original sources
PubMed1995

A pilot study of alcohol and drug-related traffic accidents and death in two Jamaican parishes, 1991.

This study is a preliminary effort to document the role of drugs in motor vehicle accidents as it examines the presence of alcohol, marijuana and cocaine in blood samples of thirty-one motor vehicle fatalities. The study identified that males (90.3%) and pedestrians (41.9%) were killed most often. Evidence of alcohol intake was found in 77.5% of the fatalities and 35.5% had alcohol levels above the legal acceptable limits. Traces of marijuana were found in 22.5% and a combination of alcohol and marijuana in 22.5% of the victims.

Accidents, Traffic↗
PubMed1994

Molecular analysis of the Drosophila EGF receptor homolog reveals that several genetically defined classes of alleles cluster in subdomains of the receptor protein.

Mutations in the torpedo gene, which encodes the fruitfly homolog of the epidermal growth factor receptor (DER), disrupt a variety of developmental processes in Drosophila. These include the survival of certain embryonic ectodermal tissues, the proliferation of the imaginal discs, the morphogenesis of several adult ectodermal structures and oogenesis, torpedo is genetically complex: a number of alleles of the gene differentially affect the development of specific tissues, such as the eye, wing, bristles and ovary. In addition, torpedo mutations exhibit interallelic complementation. Molecular analysis of 24 loss-of-function mutations in the torpedo gene provides insights into the mechanistic basis of its genetic complexity. We observe an intriguing correlation between molecular lesions and mutant phenotypes. Alleles that differentially affect specific developmental processes encode receptors with altered extracellular domains. Alleles that fully or partially complement a wide range of embryonic and postembryonic torpedo mutations encode receptors with altered intracellular domains. From these findings we conclude the following. First, the torpedo protein may be activated by tissue-specific ligands. Second, the torpedo receptor tyrosine kinase may phosphorylate multiple substrates. Third, signal transduction by torpedo appears to require the physical association of receptors. Finally, the extracellular domain of the Torpedo protein may play an essential role in mediating receptor-receptor interactions.

Alleles↗
PubMed1992

The torpedo (DER) receptor tyrosine kinase is required at multiple times during Drosophila embryogenesis.

The torpedo (DER) gene of Drosophila, which encodes a receptor tyrosine kinase of the EGF receptor subfamily, is essential for oogenesis, embryogenesis and imaginal disc development. To gain insight into the nature of the signals transduced by the torpedo product, we have characterized the gene's loss-of-function phenotype in the embryo. Through the induction of germline clones, we provide a genetic demonstration that maternal torpedo product does not contribute to zygotic development. Thus, the embryonic lethal phenotypes examined accurately reflect the consequences of eliminating all gene activity from the zygote. Temperature-shift experiments with the conditional allele topIF26 show that torpedo is required at two distinct times during embryonic development: the gene is first needed for germband retraction and for the production of anterior, posterior and ventral cuticle, then later for the secretion of ventral denticles. Since denticle formation can be severely disrupted in topIF26 animals without affecting cuticle production, the early and late requirements for torpedo appear to be functionally unrelated. torpedo, therefore, is required at multiple times in the development of the ventral epidermis, and may transduce qualitatively different signals. Since the early requirement for torpedo correlates with the first visible defect in embryonic development, increased cell death in the amnioserosa, cephalic ectoderm and ventral epidermis, the abnormalities in cuticle production and germband shortening seen in the mutant may be secondary consequences of a primary defect in cell viability. Given that the onset of cell death in torpedo embryos is not preceded by any obvious defects in mitogenesis, the establishment of cell identities or the maintenance of gene expression, it is possible that torpedo transduces a signal necessary for cell survival per se during early embryogenesis. During late embryogenesis, torpedo may mediate the reception of a second signal which regulates ventral epidermal cell differentiation.

Animals↗
PubMed1985

Power in nursing.

Explore the source record for details and available documents.

Assertiveness↗
PubMed1978

Development of masturbation in college women.

To elucidate a number of hypotheses about the development of sexual responsivity in women, a random sample of 100 undergraduate women was interviewed about their masturbation histories, techniques in masturbation, and the relationship of masturbation to intercourse. Masturbation had been practiced by 74%. It began most commonly as an accidental discovery. Learning the sexual nature of masturbation from peers and written sources seemed to result in methods more imitative of heterosexual activities and to increase the enjoyment and goal-directedness of the behavior. The view that experiencing sexual pleasure depends on social transmission of scripts was thus supported. Several techniques were related to orgasm ability in masturbation and intercourse. Women who were orgasmic in masturbation and who masturbated with that goal were more likely to continue the behavior than those with other goals. Frequency of masturbation and frequency of intercourse were not related, failing to support the notion of a unitary "sex drive". Nor was "clitoral fixation" documented by any relationship between reliance on clitoral stimulation in both masturbation and intercourse. Masturbating to orgasm was not related to orgasm ability in intercourse.

Adolescent↗
PubMed1978

Prognosis in tetanus: Use of data from therapeutic trials.

There is a need in clinical tetanus for a simple prognostic classification for all patients at time of admission to the hospital. Data from three randomized clinical trials performed in India in the 1960s, which contained information on several prognostic variables for 1,385 patients, have been used to study different methods of prognosis. A logistic regression performed on the combined data from the trials suggested that the probability of death is related separately to the period of onset (the time from the first symptom to generalized reflex spasms), to the time from first symptom to admission to the hospital, and to the clinical assessment of severity of tetanus on admission; the effects of these variables have been studied by tabulation. A new system is proposed for assigning patients to three prognostic groups, defined by time from first symptom to admission and whether or not reflex spasms were present on admission to the hospital. The range of fatality rates is 10%--63%. Neonates are assigned to a separate group with a fatality rate of 72%. Other prognostic groupings are also explored in case it is felt that the above method relies too heavily on local arrangements for medical care.

Child, Preschool↗