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Biomedical subjects

S Pearce

Publications and source records attributed to S Pearce.

At least 73 records · Page 4Linked to original sources
PubMed1990

Cognitive responses and the control of post-operative pain.

This paper examines the relationship between spontaneous cognitive responses and reported pain experience in an acute pain population. Fifty-two patients, admitted for planned major surgery, had their pain intensity, distress and coping responses assessed 48 hours post-operatively. Significant correlations were obtained between negative responses and ratings of pain intensity and distress. No significant correlation was obtained between the analgesic dose and any other variable. The implications of the findings for the management of post-operative pain are discussed.

Abdomen↗
PubMed1990

Hypothyroidism and deficiency of the nocturnal thyrotropin surge in children with hypothalamic-pituitary disorders.

The circadian pattern of serum TSH in normal children, aged 5-18 yr, is characterized by a nocturnal surge and is presumably related in some way to a biological clock within the central nervous system. To look for patients deficient in the nocturnal TSH surge, we studied 52 children with hypothalamic-pituitary disorders. Thirteen of the children were hypothyroid, as judged by subnormal serum free T4 (FT4). The hypothyroid patients had a mean nocturnal TSH surge of 22% (range, -30% to +114%), significantly less than that of normal controls (mean, 124%; 95% confidence limits, 47-300%; n = 96; P less than 0.01). Only 1 of the hypothyroid children had a value for the nocturnal TSH surge (114%) that was within the normal range. Nineteen of the 52 patients with hypothalamic-pituitary disorders had subnormal nocturnal TSH surges; their mean iodothyronine values were significantly less than those of the 33 patients with normal surges [total T4, 73 +/- 4 (mean +/- SE) vs. 109 +/- 3 nmol/L (P less than 0.01); FT4, 13 +/- 1.0 vs. 19 +/- 0.5 pmol/L (P less than 0.01)]. These data demonstrate a clear association of a deficient nocturnal TSH surge and low iodothyronine concentration in children with hypothalamic-pituitary disorders. We performed both TRH tests and nocturnal TSH surge tests in 11 of the children with central hypothyroidism; TRH was abnormal in only 2, while the nocturnal surge test was abnormal in 10 of the 11. We suggest that the nocturnal surge of TSH is important for maintenance of thyroid function and conclude that the nocturnal TSH surge is a much more sensitive test than the TSH response to TRH for the diagnosis of central hypothyroidism.

Adolescent↗
PubMed1990

Effect of high-density lipoprotein on bovine granulosa cells: progesterone production in newly isolated cells and during cell culture.

It has been proposed that changes in steroidogenesis which occur during early development of the corpus luteum may be due to increased availability of lipoproteins. Bovine follicular fluid, however, contains significant amounts of high-density lipoprotein (HDL), and granulosa cells are exposed to this lipoprotein before ovulation. To determine whether bovine granulosa cells can utilize HDL the effects of this lipoprotein on freshly isolated, non-luteinized granulosa cells and on granulosa cells undergoing luteinization in serum-free culture were examined. Cells were isolated from non-atretic, antral follicles and cultured for 12 h in 10% (v/v) lipoprotein-deficient serum to allow cell attachment. After this time cells were cultured in serum-free medium. During culture the cells underwent functional luteinization as assessed by an increase in basal progesterone output (9.6-fold in 7 days) which was associated with a marked increase in activity of cholesterol side-chain cleavage and loss of aromatase activity. Dibutyryl cyclic AMP (dbcAMP) increased basal production of progesterone about twofold but HDL alone had no effect. Addition of HDL plus dbcAMP, in contrast, caused a very marked stimulation (up to ten times) of basal steroidogenesis. This trophic effect of HDL and dbcAMP lasted at least 2 weeks. Activity of cholesterol side-chain cleavage was stimulated (threefold over basal) by dbcAMP during culture but HDL was without effect, alone or with dbcAMP. Addition of HDL (in the presence or absence of dbcAMP) to freshly isolated granulosa cells had no significant stimulatory effect on progesterone production over 12 h in six experiments, and in two of these experiments a significant inhibitory effect was seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

A randomized controlled trial of medroxyprogesterone acetate and psychotherapy for the treatment of pelvic congestion.

The value of medroxyprogesterone acetate (MPA) and of psychotherapy in the treatment of lower abdominal pain due to pelvic congestion was assessed in a randomized controlled trial. Eighty-four women with abnormal pelvic venography were assigned to one of four treatment groups: MPA alone, MPA plus psychotherapy, placebo alone, and placebo plus psychotherapy. Women were treated for 4 months and thereafter followed up regularly for 9 months with pain assessments, pelvic ultrasound scanning, and hormone measurements. During treatment, MPA showed a significant benefit in terms of a reduction in visual analogue scale pain score, with 73% of women reporting at least 50% improvement compared with 33% of those treated with placebo. At 9 months after the end of therapy there was no overall significant effect of MPA or psychotherapy, but there was an interaction between MPA and psychotherapy, with 71% of the women in this group showing a greater than or equal to 50% reduction in pain score. Therapy with MPA is a useful first-line therapy for women with pain associated with demonstrable pelvic congestion.

Adult↗
PubMed1989

Anxiety, type A personality and endocrine responses to surgery.

Twenty-seven patients underwent major abdominal surgery. Trait Anxiety and Type A personality were measured pre-operatively, and plasma cortisol, adrenaline and noradrenaline were measured pre-, per- and post-operatively. Anxiety correlated positively with noradrenaline but negatively with cortisol and adrenaline. Type A also showed opposite correlations with adrenaline and noradrenaline.

Adolescent↗
PubMed1989

Three methods compared for estimating the fraction of testosterone and estradiol not bound to sex-hormone-binding globulin.

Here we propose and validate, both theoretically and experimentally, a new technique for measuring the percentage of non-sex-hormone-binding globulin (SHBG) bound to testosterone and estradiol. In this method, SHBG is saturated with 1 mumol of 5 alpha-dihydrotestosterone per liter and the non-protein-bound fraction is subsequently measured in treated and untreated samples by centrifugal ultrafiltration dialysis (CUFD). We compared this technique with two previously published methods for measuring the percentage of albumin-bound steroid--ammonium sulfate precipitation and heat denaturation of SHBG followed by CUFD--and also with previously published computer predictions. The ammonium sulfate precipitation gave results closest to the computer-predicted percentage of albumin-bound testosterone and estradiol. Of the two techniques involving CUFD, the 5 alpha-dihydrotestosterone saturation method was the more reproducible. Results by both CUFD methods were higher than the computer-based predictions for albumin-bound steroid in pregnancy serum, in part perhaps because the CUFD measurements represent the non-SHBG-bound fraction rather than that which is albumin-bound alone.

Ammonium Sulfate↗
PubMed1988

Enzyme-linked immunosorbent assay for ileal human goblet cell mucin.

A sandwich ELISA for measuring ileal human goblet cell mucin has been developed with a linear response range 0.2 to 1.5 ng mucin protein. It can be used to quantitate the mucin present in dilute and unpurified samples without interference from other glycoproteins and proteins. Reduction of the mucin decreased the reactivity by only 14% indicating that the assay reacts almost as well with mucin glycopeptides as with native mucin. The assay has the advantages over previously described immunoassays for mucin of giving a result in 6 h, detecting slightly lower concentrations of mucin, and is more sensitive, quantitative and specific than the traditional protein or periodic acid-Schiff assays used for glycoproteins.

Animals↗
PubMed1988

Psychological and somatic factors in women with pain due to pelvic congestion.

Chronic pelvic pain in association with dilated pelvic veins and polycystic ovaries is a common complaint in women in the reproductive years, regardless of whether or not they have been pregnant. These women have a higher incidence of deaths and illnesses amongst family members and close relatives which makes them pay more attention to physical complaints such as pain which may make them more susceptible to environmental "stress" of daily life. A hypothesis is put forward which would link the effects of stress to the somatic changes observed in women with what is here described as the pelvic pain syndrome.

Adult↗
PubMed1988

The relationship of preoperative distress to endocrine and subjective responses to surgery: support for Janis' theory.

To test Janis' theory that preoperative worry can improve postoperative recovery, endocrine and subjective responses were measured in 27 patients undergoing major abdominal surgery which entailed threat to their health or longevity. Questionnaires to assess emotional and somatic state were completed preoperatively and for 7 days postoperatively. Plasma cortisol, noradrenaline, adrenaline, and glucose were measured pre-, per-, and postoperatively. Preoperatively, noradrenaline correlated positively with pain and distress, and adrenaline negatively. Postoperatively, endocrine levels and distress were not clearly related. Nevertheless, preoperative pain negatively correlated with postoperative adrenaline and cortisol levels. This, and the negative correlation between preoperative distress and postoperative pain are consistent with Janis' theory. In addition, we found that the longer patients waited on the day of surgery, the greater were the cortisol, noradrenaline, and glucose responses.

Adolescent↗
PubMed1987

Pelvic pain in women.

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Colonic Diseases, Functional↗
PubMed1986

Site of gossypol inhibition of steroidogenesis in purified mouse Leydig cells.

Gossypol, a phenolic compound that has been studied as a potential male contraceptive, inhibits basal and LH-stimulated testosterone release from Leydig cells in vitro. The present study investigates the mechanism of this inhibition using preparations of purified mouse Leydig cells. Gossypol inhibited LH-stimulated progesterone, 17-hydroxyprogesterone and androstenedione production by mouse Leydig cells incubated in vitro. It also inhibited dibutyryl cyclic AMP-stimulated production of testosterone but was without effect in the presence of added pregnenolone or 25-hydroxycholesterol. These results suggest gossypol exerts its major inhibitory effect on Leydig cell function at a point between LH-dependent stimulation of cyclic AMP dependent protein kinase activity and increased availability of cholesterol for side chain cleavage.

17-alpha-Hydroxyprogesterone↗
PubMed1986

Inhibition by gossypol of cyclic AMP production in mouse Leydig cells.

Gossypol has been shown to inhibit steroidogenesis in leydig cells. This study examined the mechanism of this action by investigating the effect of gossypol on leydig cell hCG receptor binding, adenylate cyclase activity and cyclic AMP production in leydig cells. Gossypol had no effect on hCG binding to cell membranes but inhibited LH-stimulated cyclic AMP production in whole purified leydig cells. It also reduced the stimulation caused by LH, Gpp(NH)p, forskolin and fluoride in membranes from leydig cells and also from liver. It is therefore possible that gossypol affects cyclic AMP production at the level of ATP conversion to cyclic AMP, although effects on the G-protein and catalytic subunit cannot be ruled out.

Adenylyl Cyclases↗
PubMed1985

The viability of mouse Leydig cells in vitro following incubation with gossypol.

Gossypol, a phenolic compound that has been studied as a potential male contraceptive, has also been shown to inhibit basal and LH-stimulated testosterone production by mouse Leydig cells in vitro. This inhibition persists even when cells treated with gossypol are washed prior to reincubation with LH. While gossypol has been reported to be cytotoxic, its effect on steroidogenesis does not appear to be a consequence of cytotoxicity as there was no reduction in the number of viable cells after incubations in which inhibition of testosterone production was observed.

Animals↗
PubMed1984

Diagnosis of pelvic varicosities in women with chronic pelvic pain.

45 women with a history of lower-abdominal pain of more than 6 months' duration for which no obvious cause had been found during laparoscopy (pelvic-pain syndrome) were investigated with transuterine pelvic venography. For comparison venography was carried out on 10 women in whom pathology was considered to be a likely cause for their pain and 8 women admitted for tubal ligation and who had no pain. Pelvic varicosities and congestion unrelated to parity or the menstrual cycle were commonly found in women with the pelvic-pain syndrome. A score for quantifying the severity of the pelvic vascular abnormalities has been devised; a value of 5 or more gave a diagnostic sensitivity of 91% and a specificity of 89% for the pelvic-pain syndrome.

Adult↗
PubMed1984

Development of a variable stiffness external fixation system for stabilization of segmental defects of the tibia.

The mechanical properties of a variable stiffness external fixation system were explored. Initial testing of a unilateral fixator configuration demonstrated that system rigidity could be increased by maximizing pin separation distance in the fracture component and the number of pins used while minimizing pin separation distance across the fracture site and the sidebar offset distance from bone. A triangulated system composed of half pin frames mounted anteriorly and medially on the tibial aspects and linked by crossbars was devised. Progressive disassembly of the frame was shown to result in progressive decreases in fixator rigidity in all planes.

Biomechanical Phenomena↗