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Biomedical subjects

D W Wilson

Publications and source records attributed to D W Wilson.

At least 163 records · Page 9Linked to original sources

An effective and reliable computerised system for storage and retrieval of references to scientific publications.

A suite of programs has been implemented to facilitate the storage and retrieval of references to published works in a typical scientific research establishment. The retrieval process is governed by searches for specified combinations of keywords, author names, individual references, and lengths of time that references have been held on file. The system currently caters for approximately 1290 journals together with abstracts, reports, supplements, symposia, proceedings and books. Five years experience has proved the system to be reliable and effective, and it requires only 1.5 technician-days per week to operate it and to input about 25 000 articles annually. This system fulfills a requirement felt by many specialised institutions in providing localised control over quantities of information which are too large to be processed manually.

Bibliographies as Topic↗

Assessment of testicular function by the radioimmunoassay of testosterone in saliva.

A sensitive RIA (500 fg/tube) has been developed for assay of testosterone in male saliva and extensively validated. In normal male saliva samples, morning concentrations (368 +/- 167 pmol/l) were significantly higher than evening samples (212 +/- 132 pmol/l). The circadian rhythm was confirmed by COSINOR analysis. Levels of testosterone in saliva, in response to HCG stimulation, accurately reflected the increase observed in matched plasma samples. Synacthen administration, although increasing circulating cortisol levels, caused no significant change in plasma and salivary testosterone concentrations. Prostatic cancer patients on diethylstilboestrol therapy had low salivary (47--122 pmol/l) and plasma (1.0--2.8 nmol/l) testosterone concentrations. Correct assessment of testicular function following stimulation and treatment regimens requires multiple sampling. Since saliva samples are easily collected by non-invasive techniques they represent an attractive alternative to plasma for evaluation of androgenicity.

Adolescent↗

Internal quality control of radioimmunoassays: monitoring of error.

A cumulative sum technique has been specially designed to monitor the error between replicate determinations made on quality control plasma for consecutive batches of assays. This procedure has played a vital role in assessing assay performance. Special consideration has been given to small sample sizes (n = 2 or 3) which is generally the rule rather than the exception in many situations. This technique has been applied to numerous steroid radioimmunoassays and has ensured that both the mean value and the standard error of hormone levels of a quality control pool were under control. Data from routine assays of oestriol and testosterone in plasma from women are presented. Since this technique provides a sensitive measure of monitoring error, it assists the endocrinologist in elucidating statistical inferences which are a manifestation of assay performance.

Estriol↗

Oxygen incineration and electron microscope x-ray microanalysis of mineral particles in biological tissues.

Techniques employed for the recovery from biological tissues of noncombustible fine particles such as asbestos, talc, kaolin and diatomaceous material were assessed by electron microscope x-ray microanalysis. Recovery procedures which have been proven successful for lung tissue were found to be impracticable for more solid types of tissues. Digestion techniques employing acids, alkalis or enzymes and standard incineration procedures were found to be unsatisfactory for human adrenal, cervix, liver and ovarian tissues when the resultant residues were examined by electron microscope microanalysis. The recovered particles were often completely masked with residues which were shown to be composed of organic elements. The use of oxygen during the incineration process completely removed this contaminating material in nearly all cases studied. When such procedures were used, clearly defined particles were recovered from the tissue, thereby permitting x-ray analysis. A quantitative analysis could then be made to estimate the particle content in a variety of tissues.

Electron Probe Microanalysis↗

Internal quality control of radioimmunoassays.

A modified cumulative sum technique has been applied to radioimmunoassay quality control data. The method is approximately 50% more efficient in detecting systematic changes in the mean and variance of quality control values for plasma samples than more widely used conventional methods. The salient features of the technique have been restricted to changes in the mean quality control value of a plasma pool, but potential applications to changes in variance and as a diagnostic aid to problems in radioimmunoassay have been evaluated. The method is independent of computing facilities and statistical expertise since all computations have been presented in the form of a nomogram and thus can be used by technicians at the bench.

Estradiol↗

An improved enzyme immunoassay for progesterone in human plasma.

We describe an enzyme immunoassay for progesterone in which we use a progesterone-11alpha-hemisuccinyl-horseradish peroxidase conjugate as the "label" and an antiserum raised in rabbits to a progesterone-11alpha-hemisuccinyl-bovine serum albumin conjugate. In this assay, antibody-bound and free steroid are separated by using a second antibody precipitation procedure. The assay has a lower limit of sensitivity of 10 pg/assay tube and satisfies the usual criteria of specificity, precision, and accuracy. Results obtained with a comparison radioimmunoassay and our procedure agreed well (r = 0.98). Eighty samples can be assayed per day. It is not only well suited for surveys where accurate determination of progesterone concentrations in small plasma aliquots is required, but also for monitoring ovulation induction in patients attending infertility clinics.

Cross Reactions↗

The operative management of the difficult supracondylar fracture of the humerus in the child.

A series of supracondylar fractures of the humerus in children is presented. The majority was reduced by closed manipulation. The difficult fractures were defined as those in which adequate reduction either could not be achieved by manipulation or was not maintained, or those in which neurological or vascular complications occurred. Such cases were treated by open reduction and internal fixation. The results were assessed with regard to loss of elbow movement, deformity and symptoms. The results of the operative series were comparable with those achieved by closed manipulation in the easier cases. No secondary corrective procedures were necessary. It is concluded that closed manipulation should be used routinely as the method of treatment for supracondylar fractures of the humerus in children, except in the difficult case, for which operative treatment should be undertaken. Stiffness or deformity does not follow open reduction and internal fixation.

Adolescent↗

Effects and residues of dietary hexachlorobenzene in growing swine.

Crossbred weanling gilts were fed a standard ration containing 0, 1, 10, or 100 ppm purified hexachlorobenzene (HCB) for 13 wk. No mortalities, ill health, neurological disorders, or significant depressions in weight gain were observed. Postmortem examination revealed brightly fluorescent livers at all levels of HCB. The group receiving 100 ppm had a tendency for smaller spleens, larger livers with swollen hepatocytes, and decreased lymphocytes. HCB accumulated in the dissectable fat of growing swine to concentrations five- to sevenfold higher than the dietary concentration; residues in 11 other tissues examined were below the dietary concentration.

Adipose Tissue↗

Sturcture-activity relationship of daunorubicin and its peptide derivatives.

The synthesis of potentially specific antitumor peptide derivatives of daunorubicin is presented. The interaction specificites of the drugs with nucleic acids have been examined via stop-flow kinetics as well as the inhibition of DNA template activity. It is found that the biological activity of the daunorubicin derivatives against the mouse P388 tumor is directly proportional to RNA polymerase inhibition and inversely proportional to the rate of dissociation of the DNA complex. It is concluded that the biological efficacy of drugs which act at the replicative and transcriptional level may be estimated by the more rapid in vitro techniques provided that problems of permeability, solubility, stability, etc., in vivo are not encountered.

Animals↗

Effects of noise and perceived control on ongoing and subsequent aggressive behavior.

Two experiments examined the effects of high-intensity (95 dB [A]) noise on ongoing and postnoise aggressive behavior. In Experiment 1, subjects were angered or treated in a neutral manner and given an opportunity to aggress against another subject while being exposed to high-intensity (95 dB) or low-intensity (55 dB) noise. Results indicated that high-intensity noise facilitated aggression for previously angered individuals. Experiment 2 examined postnoise aggression in which subjects completed a math task under high-intensity noise with or without perceived control over the noise. In comparison to a no-noise control, it was found that angered subjects with no control revealed an increase in aggression, whereas perceived-control subjects were no different from no-noise subjects. Results are discussed in terms of the recent Glass and Singer work on noise and task performance and the effects of perceived control on mediating the effects of stressful conditions.

Adaptation, Psychological↗