Search PubMed⌕ Search

Biomedical subjects

D Williams

Publications and source records attributed to D Williams.

At least 559 records · Page 31Linked to original sources
PubMed1980

Optimization of diagnostic discrimination applied to the amniotic fluid lecithin/sphingomyelin ratio.

An unrecognized disparity frequently separates the intuitive reliance placed on laboratory information by those who produce it and those who use it. To harmonize these dissimilar perceptions requires quantitative measures of the information contained in laboratory data. The assay of the lecithin/sphingomyelin ratio in amniotic fluid is used as an example to analyze the discriminatory ability of a test. This assay can be optimized from the different viewpoints of sensitivity, specificity, diagnostic effectiveness or value. In each case test results are interpreted in the light of different factors and so the optimal decision threshold to separate positive from negative results may vary. Appreciation of this concept would endow the interpretation of laboratory tests with the same flexibility traditionally available to other clinical information.

Amniotic Fluid↗
PubMed1980

Transhepatic embolisation of gastro-oesophageal varices in the management of variceal haemorrhage.

The difficulty of controlling variceal haemorrhage has led to the recent development of methods designed to sclerose the bleeding vessels. This study describes the application of percutaneous transhepatic portal catheterization with embolisation and sclerosis of varices in eight consecutive patients admitted with bleeding oesophago-gastric varices. Portal hypertension was documented and varices demonstrated in each case. Bleeding ceased rapidly in seven patients, two patients rebled 1-3 weeks after the procedure, and five patients were subsequently discharged from hospital. In no instance was death related to continued gastrointestinal haemorrhage. Initial experience with transheptic embolisation of bleeding oesophago-gastric varices indicates that this technique is effective in controlling variceal haemorrhage.

Adult↗
PubMed1980

Hemoglobinopathies observed in the population of the Southeastern United States (SE-USA).

A survey of nearly 250,000 citizens of Georgia and South Carolina conducted during the past twenty years has led to the detection of over 40 abnormal hemoglobins and several additional hemoglobinopathies. The presence of some of these hemoglobin abnormalities cause (severe) clinical symptoms but others remain undetected unless a specific search is initiated. The incidence of Hb S varies slightly among the populations of different areas, and appears to be the highest in the coastal counties of Georgia and South Carolina. A survey of over 17,000 persons of mainly high school and college age has shown that a significant number of cases with clinically significant hemoglobinopathies will remain undetected unless such surveys are actively promoted.

Adolescent↗
PubMed1979

The right to strike.

Explore the source record for details and available documents.

Collective Bargaining↗
PubMed1979

The clinical measurement of urinary total hydroxyproline excretion.

The effect of dietary control on the day-to-day variation in total hydroxyproline excretion has been examined in two studies. In the first, a normal volunteer ate a controlled diet containing varying gelatin supplements for several weeks. In the second, the effect of removing hydroxyproline-containing foods from the diets of 8 volunteers was examined. Both studies confirm that the day-to-day variation in total hydroxyproline excretion falls when the gelatin content of the diet is decreased, whether the results are expressed as total hydroxyproline excretion rate or as the total hydroxyproline: creatinine ratio. This fall in variation takes place within 24 h of dietary control beginning and therefore longer periods of dietary restrictions to achieve optimum precision in the measurement of total hydroxyproline are unnecessary. For some analytical methods, results are better expressed as the ratio total hydroxyproline:creatinine than as the total hydroxyproline excretion rate.

Adult↗
PubMed1979

Value of cytology for detecting endometrial abnormalities in climacteric women receiving hormone replacement therapy.

Over six months 113 endometrial specimens from 110 menopausal women receiving hormone replacement therapy were examined by two cytologists and two histopathologists. Specimens were obtained by aspiration with the Isaacs cell sampler immediately before Vabra suction curettage, both procedures being performed in the outpatient department without anaesthetic. The histologists agreed with each other on the classification of 85 specimens (75.2%) and the cytologists agreed on the classification of 44 (38.9%). In only 15 cases (13.3%) did all four observers agree. Of the three cases of cystic or adenomatous hyperplasia detected histologically, only one was diagnosed by cytology. Furthermore, both cases of adenocarcinoma escaped detection by cytology, though a third case--later confirmed-"was suspected by one cytologist alone. Use of the Isaacs endometrial cell sampler cannot be advocated for routine screening of women with climacteric symptoms receiving hormone replacement therapy. Efforts should be made to establish the correct dose and duration of treatment with an oestrogen-progestogen preparation in order to avoid over-stimulating the endometrium and the need for regular screening for endometrial abnormalities.

Adenocarcinoma↗
PubMed1979

Histochemical characterization of monoamine oxidase in ependyma of rat hypothalamus.

Monoamine oxidase (MAO) activity has been demonstrated histochemically in rat hypothalamic ependyma using the sulphate-tetrazolium and coupled peroxidatic techniques with tryptamine, tyramine, 5-hydroxytryptamine and benzylamine as substrates. Both methods were applied to cryostat sections with and without exposure to selective amine oxidase inhibitors, including the selective A-MAO inhibitor clorgyline, and the B-MAO inhibitor deprenyl. Our results show that both cuboidal-columnar and tanycyte ependyma contain one or more forms of MAO not generally present in the hypothalamus. It is suggested that ependymal MAO may form an amine-barrier system modulating the movement and effect within the hypothalamus of specific cerebrospinal fluid or blood monoamines.

Animals↗
PubMed1979

A comparison of chromium sesquioxide and [51Cr]chromic chloride as inert markers in calcium balance studies.

1. Chromium sesquioxide (Cr2O3; 1.5 g/day) and [51Cr]chromic chloride [51CrCl3 (0.3 muCi/day)] were compared as continuously administered non-absorbed markers for the correction of faecal recoveries in 14 calcium balance studies each lasting at least 18 days. 2. The mean recoveries of each, 98.4% for Cr2O3 and 101.9% for 51CrCl3, were not significantly different from 100%. 3. The two markers reduced the uncertainity in a typical 3 x 6 day calcium balance study to a similar extent (SD = 1.4 mmol/day for Cr2O3 and SD = 1.5 mmol/day for 51CrCl3. 4. 51CrCl3 is a convenient and satisfactorily alternative to Cr2O3 when the laboratory hazards associated with estimating the latter cannot easily be eliminated.

Calcium↗
PubMed1979

The identification of 'casein' in human breast cancer.

A retrospective study of ninety-six cases of breast cancer was carried out to determine the prognostic values of a casein immunolocalization technique. This was performed using an indirect immunofluorescence method with antisera raised in rabbits to pooled human casein. Fluorescence positivity was graded according to its intensity and distribution. The pathology of each tumour was studied and the tumour type, histological grade and tissue response assessed. The relationship between these observations and the casein content of the tumour was studied. In addition the correlation between casein content and age, menopausal state, clinical staging and survival was investigated. The incidence of casein positivity in our series was 50% with approximately half of the positive cases showing strong fluorescence. There was a relationship between casein content and the age of the patients, with casein being more frequently found in tumours from younger patients. Tumours with a high casein content, in general, show a poorer survival than the group as a whole. This difference in survival was most marked in the first eight years after operation and restricted to those tumours in clinical stage I and histological grade I. The presence of casein in the tumours did not appear to be related to the other factors examined.

Adult↗