Search PubMed⌕ Search

Biomedical subjects

C Selby

Publications and source records attributed to C Selby.

68 records · Page 4Linked to original sources
PubMed1984

Oral contraceptive agents do not affect serum prolactin in normal women.

A total of 230 healthy women attending family planning clinics took part in a cross-sectional study, comparing contraceptive histories and serum prolactin levels. It was found that the distribution histogram of serum prolactin was markedly skewed to the right in all main groups, but that the distribution profile was not affected by use of oestrogen-containing contraceptives. Neither the dose of oestrogens nor duration of their use affected prolactin levels. We have thus found that currently available combined oral contraceptive agents have no effect on serum prolactin. Analysis of the skewed raw data yields a 'normal' range of 110-700 mU/l, higher than that usually accepted.

Adolescent↗
PubMed1984

A simple DHEAS loading test in the antepartum diagnosis of placental sulphatase deficiency.

The accurate antenatal diagnosis of placental sulphatase deficiency (PSD) is essential if this condition is to be distinguished from others in which levels of oestrogen are low. In this study we have evaluated a simple protocol determining the serum oestradiol response to 50 mg of dehydroepiandrosterone sulphate (DHEAS) given intravenously to twelve women with low serum or urinary oestrogens. Seven of the women had PSD confirmed by other means, the remaining five had other reasons for the low oestrogen levels. In affected pregnancies the rise in oestradiol was lower, the peak occurred earlier and the level fell towards baseline at 60 min. In the unaffected women, timing of the peak value was not consistent and there was no trend towards basal values at 60 min. There was clear discrimination between the two groups at all times after the injection, but the separation was greater at 60 min.

Dehydroepiandrosterone↗
PubMed1983

Nuclear progesterone uptake by endometrial tissue in cases of subfertility.

To investigate the ability of steroid hormones to interact with endometrium, particularly in cases of unexplained subfertility, intact cells were incubated with tritiated progesterone and oestradiol and their uptake into the nuclei was measured. Samples were taken at dilatation and curettage from 23 fertile women, 14 women with unexplained primary subfertility, and 9 patients whose primary subfertility could be explained. Serum oestradiol and progesterone levels were not significantly different between the three groups, nor were values of 3H-oestradiol uptake. However, low (below 5 pmol/mg DNA) values for nuclear 3H-progesterone uptake were present in most samples from women with unexplained subfertility but in only about half of the women in the other two groups. This biochemical defect may be the cause of some cases of unexplained subfertility.

Cell Nucleus↗
PubMed1983

Detection of photomutagens in natural and synthetic fuels.

The contribution of non-ionizing radiation to synfuel-related skin carcinogenesis is largely unknown. We have employed a modification of the Salmonella histidine reversion test system to detect photomutation by various fuel substances. For photomutation testing we washed and resuspended cells in buffer, irradiated with 'visible' light in the presence of test substance, and removed aliquots after various light exposures for assay by the plate incorporation method. We have assayed photomutagenicity and microsome-mediated mutagenicity of a crude petroleum, a shale oil, and coal hydrogenation process intermediates. Photomutagenicity was studied using one concentration of each oil; peak revertants per plate for most oils tested were relatively similar to revertants per plate with microsomal activation of the same oil at the corresponding concentration. The shale oil was an exception to this pattern: with light activation, peak revertant numbers per plate were approximately 10 times the value observed with microsomal activation. The samples tested are not assumed to be representative of all petroleums, shale oils or coal oils. Our results do suggest that environmental radiation may be a significant factor in synfuel-related skin carcinogenesis and that photomutagens may be different from enzyme-activatable promutagens.

Animals↗
PubMed1983

Changes in plasma steroid hormones during treatment of preterm labour with ritodrine-HCl.

Peripheral plasma concentrations of unconjugated oestradiol 17-beta, progesterone and total oestriol were measured in 21 patients presenting with 'uncomplicated' preterm labour. Serial measurements were made during intravenous treatment with ritodrine over a period of 24 h. Mean levels of unconjugated oestradiol 17-beta fell significantly during infusion with ritodrine. Changes in progesterone levels remained within the range of diurnal fluctuations normally found in uncomplicated late pregnancy. Mean total oestriol levels fell significantly, but the changes did not exceed normal variations. No correlation was found between the magnitude, the rate or the timing of changes in any of the hormones measured and the short or long term effects of ritodrine on uterine activity. Although alterations in the peripheral oestrogen concentrations may be a direct effect of beta-mimetics, it is unlikely that this mechanism is important in the inhibition of uterine activity.

Adolescent↗
PubMed1981

The somatomedin activity in plasma from patients with multiple mechanical injuries: with observations on plasma cortisol.

The somatomedin activity (SMA) was assayed in 247 plasma samples from 30 patients with moderate or severe injuries. The injury severity score (ISS) was assessed for each patient and ranged from 9 to 50. The plasma SMA was reduced or eliminated within 4 days of injury. The activity then increased in the patients who recovered, normal levels being attained within 1 or 2 weeks of the injury. Five patients had at least one further fall in plasma SMA during treatment. Seven patients died and 4 of these had little or no SMA before death. The magnitude and duration of the depression of SMA after injury correlated both with the ISS and with the probability of mortality. The plasma cortisol concentration was elevated in all but 4 patients within 48 hours of injury. There was no relationship between the plasma SMA and the cortisol concentration. When plasma samples from 10 patients taken soon after injury were mixed with normal human serum, samples from only 1 patient were found to contain an inhibitor(s) of SMA. The reduced plasma SMAs in the remaining patients may have resulted from the impaired production of somatomedins (SM), the degradation of SM, the dilution of circulating SM with transfusion fluids or the binding of SM to damaged tissues.

Accidents↗
PubMed1980

Progesterone, fluid, and electrolytes in premenstrual syndrome.

Changes in mood, plasma progesterone concentration, urinary volume, sodium excretion, sodium:potassium ratio, and body weight during the menstrual cycle were determined in 18 women with premenstrual syndrome and 10 symptomless (control group) women. Plasma progesterone concentration was higher in the women with symptoms during the postovulatory phase of the cycle, and the peak progesterone concentration appeared earlier. The changes in progesterone concentration were accompanied by a natriuresis and diuresis that fell towards preovulatory values in the premenstrual phase. Sodium retention was not confined to any definite period. Mood symptoms occurred after the changes in progesterone and electrolyte concentrations. Progesterone deficiency is probably not the cause of premenstrual syndrome. Thus treatment with progesterone is probably illogical unless a deficiency is detected. Treatment should be aimed at preventing the natriuretic effect of progesterone in the postovulatory phase and the sodium-retaining and water-retaining effects of aldosterone in the premenstrual phase.

Affect↗
PubMed1979

Treatment of premenstrual syndrome by spironolactone.

Spironlactone was given to 28 women in a double blind cross over trial during four menstrual cycles. Hormonal profiles were measured during the first two cycles. Plasma aldosterone was elevated in the premenstrual phase of the cycles but there was no significant difference between symptomatic and asymptomatic groups. The rise in serum progesterone was higher in the symptomatic group during the postovulatory phase. The administration of spironolactone reduced weight and relieved psychological symptoms in more than 80 per cent of the symptomatic group.

Aldosterone↗
PubMed1978

Somatomedin activity in synovial fluid from patients with joint diseases.

The somatomedin activity in synovial fluids from 50 patients with a variety of joint diseases has been studied and compared with the activity in each of the patient's own serum and a standard reference serum (SRS). The porcine costal cartilage bioassay of Van den Brande and Du Caju (1974a) has been used with the isotopes 3H-thymidine and 35S-sulphate. Synovial fluids from most patients with post-traumatic and post-operative effusions, osteoarthritis and arthritis associated with psoriasis, Reiter's disease, and ankylosing spondylitis stimulated the synthesis of DNA and proteoglycans in cartilage. Synovial fluids from patients with rheumatoid arthritis either had impaired capacity to stimulate DNA synthesis, or they inhibited it; a similar, but less evident pattern was observed for proteoglycan synthesis. Some synovial fluids from patients with miscellaneous synovitides stimulated, while others inhibited cartilage metabolism. It is concluded that the synovial fluid from patients with rheumatoid arthritis and from some patients with miscellaneous synovitides contained an inhibitor(s) to DNA and possibly proteoglycan synthesis. The sera from nearly all the patients stimulated both DNA and proteoglycan synthesis, but the somatomedin potency ratios for serum in terms of SRS were generally less than 1.0. There was a significant inverse correlation between the serum somatomedin potency ratio and the age of the patient.

Adolescent↗
PubMedDate not supplied

Inhibition of neutrophil adherence and movement by acute cigarette smoke exposure.

Peripheral blood neutrophils were harvested and exposed acutely in vitro to physiologically attainable levels of cigarette smoke. The adherence of radiolabeled neutrophils subsequently to alveolar epithelial cell monolayers was measured. In contrast to control cells, smoke-exposed neutrophils were significantly less adherent and failed to increase their adherence following stimulation with phorbol ester or f-met-leu-phe (fMLP). Flow cytometric analysis of the cell surface adhesion protein CD18 demonstrated no significant change in expression following in vitro smoke exposure and, furthermore, no increase in surface CD18 of smoke-exposed cells following consecutive fMLP stimulation was demonstrated. Acute in vivo cigarette smoking of up to 4 cigarettes also did not alter peripheral blood neutrophil CD18 expression. Cell spreading and chemokinesis, but not chemotaxis, was also impaired following in vitro smoke exposure. These data suggest that acute cigarette smoke may impair the crucial neutrophil functions of adherence and movement. However, the chronic effects of cigarette smoke exposure may clearly differ.

Adult↗
PubMedDate not supplied

Factors affecting neutrophil transit during acute pulmonary inflammation: minireview.

Recent studies confirm data that for over a century have suggested that the lungs are an important source of noncirculating neutrophils. Many factors control how neutrophils pass through the normal lungs, including the unique and complex structure of the pulmonary capillary bed, local hemodynamic factors, neutrophil deformability, and neutrophil-endothelial interactions. Alterations in these factors are likely to influence neutrophil traffic in the lungs in disease processes where neutrophil-induced lung injury has been implicated. In recent years experimental approaches using in vitro techniques have been used to study neutrophil function. Such studies, together with in vivo studies in whole animals and to a limited extent in humans, will help to elucidate the important mechanisms in neutrophil sequestration in the acute and chronically inflamed lung. Novel avenues of therapeutic intervention in neutrophil traffic through the lungs may then be possible. However, whether interference with this cell, which forms a major defense mechanism in the lungs, is advisable, remains a matter for debate.

Acute Disease↗