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Biomedical subjects

D White

Publications and source records attributed to D White.

At least 361 records · Page 20Linked to original sources
PubMed1981

Sexual arousability and the menstrual cycle.

Using a balanced experimental design, 30 regularly cycling woman not using oral contraceptives, aged 20 to 30 years, were assessed in a laboratory setting during the follicular, ovulatory, and luteal phases. Sexual arousal was measured by self-report and by photoplethysmographic recordings of vaginal vasocongestion. Plasma estradiol, progesterone, and testosterone were determined by radioimmunoassay. There were marked and consistent individual differences among the women in their sexual arousability. Subjective reports of sexual arousal did not differ among menstrual cycle phases, by physiologic arousal did vary with significantly higher mean levels of arousal occurring during the follicular and luteal phases than during the ovulation phase. While hormones fluctuated predictably with menstrual cycle phase, there were wide individual differences in absolute values among women. The correlations between estradiol, progesterone and testosterone and the subjective and objective assessments of arousability were mainly low and insignificant. Some evidence suggestive of a relation between testosterone and sexual arousability was observed with three subgroups of woman were formed on the basis of relative average testosterone concentrations.

Adult↗
PubMed1980

Safety in hospitals: philosophy of fire defence.

The idea that whole blocks should be warned immediately a fire is discovered, is not generally favoured in Sweden and Denmark. This is one of many fifferences of approach which David White, area education and training officer, Coventry AHA found on his Council of Europe Fellowship study tour. Here he concludes his report begun last week

Accident Prevention↗
PubMed1980

What is the preferred initial method of treatment for squamous carcinoma of the tongue?

The medical records of 152 previously untreated patients with squamous carcinoma of the tongue were reviewed. Radiation, surgery and the combination of both were analyzed with respect to the stage of disease treated, local and regional failure and ultimate salvage. The plan of treatment for a prospective patient is formulated based on the data. Surgery appears to be the best initial treatment for cancers staged T2, T3 and T4. T1 lesions can be treated with either radiation or surgery, and selection should be determined by the pertinent patient factors.

Adolescent↗
PubMed1980

Altered protein synthesis and creatine kinase in breast muscle cell cultures from dystrophic chick embryos.

The total protein synthesis (TPS), myosin synthesis (MS) and creatine kinase (CK) levels in muscle cell cultures obtained from 400 normal (strain 454) and 400 dystrophic chick embryos (strain 455) were investigated. The cultures were obtained from breast muscles of 12 day chick embryos by dissociation in 0.25% trypsin, preplating and plating of 5 x 10(5) floating cells on gelatin coated dishes in Minimal Essential Medium, 10% horse serum and 2% chick embryo extract. After 6 days, when electron-microscopic studies demonstrated good muscle differentiation, cell cultures were labeled with [3H]leucine. TPS and MS, respectively, showed 85% and 65% increases in breast muscle cell cultures from dystrophic chick embryos. The half-life times for total protein and myosin from dystrophics were 19 and 32 hr, respectively as compared with 36 and 48 hr from controls. Noncollagen protein content (NCP) showed 27% decrease in postfusion stage (12 days) of cell cultures from dystrophics. The CK level showed 30% lower values in the cells from dystrophics but 50% higher values in their culture medium. The addition of leupeptin plus pepstatin (50 microgram/ml) to these cultures resotred NCP content, total protein and myosin turnover to normal values and significantly increased TPS and MS. The addition of diphenylhydantoin (DPH) (20 microgram/ml) to cell cultures from dystrophics did not change the NCP content nor the turnover for total protein and myosin but significantly increased TPS, MS and CK while medium CK significantly decreased. The addition of leupeptin plus pepstatin or DPH to muscle cell cultures from normal chick embryos also significantly stimulated TPS and MS.

Animals↗
PubMed1980

Development of Stigmatella aurantiaca: effects of light and gene expression.

Stigmatella aurantiaca, a gliding, gram-negative bacterium, exhibits complex developmental changes upon starvation. In the light the cells aggregate and develop multicellular fruiting bodies with stalks and sporangia within 20 h. Between 23 and 27 h, sonication-resistant myxospores are synchronously formed inside the sporangia. On the other hand, in the dark, the cells aggregate and differentiate into myxospores between 13 and 27 h without forming stalks and sporangia. The pattern of protein synthesis during development in the light as well as in the dark was investigated. Three periods of synthesis, characterized by sharp increases and decreases in the rate of isotope incorporation into certain proteins, were distinguished. In the light these periods corresponded approximately to an early stage before the formation of aggregates, a middle period during which aggregates appeared and developed into fruiting bodies, and a late stage that corresponded to the appearance of myxospores. The pattern of protein synthesis in the dark could also be divided into three stages, but the middle stage was considerably shorter than in the light and showed diminished synthesis of certain proteins that were actively synthesized in the light. In particular, the synthesis of one protein was detected only in samples that developed in the light.

Bacterial Proteins↗
PubMed1980

Photocontrol of development by Stigmatella aurantiaca.

Aggregation and fruiting body formation by Stigmatella aurantiaca were stimulated most effectively by low irradiances of blue light between 400 and 500 nm. At higher irradiances, other wavelengths of light, including those in the far-red region of the spectrum, were also effective.

Light↗
PubMed1980

Morphogenetic effects of light and guanine derivatives on the fruiting myxobacterium Stigmatella aurantiaca.

When low cell densities of the myxobacterium Stigmatella aurantiaca were starved on an inorganic salts and agar medium, cell aggregation and fruiting body formation showed a striking dependency upon the presence of light. This dependency was not manifested when sufficient amounts of guanosine or guanine nucleotides were added to the medium. Light interacted cooperatively with suboptimal concentrations of guanine compounds to promote development. None of the other purine or pyrimidine derivatives, with the exception of adenine, stimulated development. However, aggregates that formed in the presence of adenine did not mature into fruiting bodies and instead disaggregated.

Guanine Nucleotides↗
PubMed1980

Effects of specific cations on aggregation and fruiting body morphology in the myxobacterium Stigmatella aurantiaca.

The cation requirements for fruiting body formation in the myxobacterium Stigmatella aurantiaca on agarose were determined. Calcium alone caused the cells to aggregate into interconnecting ridges. Under these conditions, stalk formation was severely depressed but sporangia frequently formed. The combination of magnesium and manganese was necessary for optimal formation of discrete aggregates (rather than ridges) and stalks. Manganese inhibited sporangium development. The inclusion of calcium into the magnesium-manganese medium overcame the inhibition by manganese and stimulated the production of multiple sporangia.

Calcium↗