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Biomedical subjects

P Bennett

Publications and source records attributed to P Bennett.

At least 163 records · Page 9Linked to original sources
PubMed1989

Androgens in hirsute women referred for electroepilation.

One hundred and five hirsute women were examined. Elevated levels of at least one androgen were found in 58 women, most often free testosterone, dehydroepiandrosterone sulfate and delta 4-androstenedione. No significant correlation was found between level of androgens and hirsutism score or frequency of menstrual disturbances other than amenorrhea. Fifty-three women were examined at least 6 months after electroepilation. A significant decrease in hirsutism score and frequency of self-treatment was found. Scarring was not observed. Electroepilation performed by an experienced person should be recommended as an excellent treatment for hirsutism.

Adult↗
PubMed1989

The physiology of the testes in the Göttingen mini pig.

Capillary blood flow (133xenon clearance), deep testicular and muscle temperature (needle thermistor) and androgenic hormone concentrations in peripheral blood samples (RIA) were measured and the histology (needle biopsies) evaluated in 16 anaesthetized, mature Göttingen mini pigs. The blood flow was 0.26 +/- 0.10 ml x g-1 x min-1. The testicular temperature was 33.6 +/- 1.4 degrees C, and the body temperature 37.2 +/- 0.9 degrees C. The plasma levels of testosterone were 15.2 +/- 10.1 nmol x l-1, of dihydrotestosterone 0.99 +/- 0.98 nmol x l-1, dehydro-epi-androsterone sulphate 441 +/- 333, nmol x l-1, and the delta-4 androstenedione level was 9.2 +/- 7.0 nmol x l-1. Sexual-hormone-binding-globulin was immeasurable. The histological appearance was judged to 7.8 +/- 1.0 by a testicular biopsy score (scale 10-1). The results from the present investigation are in the same range of order as in other mammals and it is concluded that the mature, male Göttingen mini pig is a useful model for reproductive research.

Animals↗
PubMed1988

Effect of oestrogen and progestagen on gonadotrophins and sex hormones in oophorectomized women.

Five premenopausal women were followed with measurements of androgens, oestrogens, gonadotrophins and sex hormone binding globulin (SHBG) after ovariectomy for benign disease. After a period of 6 weeks without treatment the women were treated with oestradiol 4 mg daily for 8 weeks, oestradiol 4 mg plus norethisterone acetate (NETA) 2 mg daily for 8 weeks and finally oestradiol 4 mg daily for another 8 weeks. The levels of androgens did not change during the various periods. As usual during oral treatment oestrone and oestrone sulphate were elevated while oestradiol levels were in the pre-operative range during treatment, regardless of the addition of NETA. SHBG was elevated during oestrogen-only treatment, while addition of NETA normalized the concentration of SHBG. In the combined NETA period concentrations of free oestradiol and non-SHBG-bound oestradiol were significantly elevated, and gonadotrophins returned to premenopausal levels, in contrast to the high levels in the oestrogen-only periods. Using oral oestrogen therapy it may be preferable to add a progestagen rather than elevate the oestrogen dose. Progestagen will result in more free oestradiol and give greater relief of symptoms, but the potentially harmful effect of progestagens on blood lipids must be considered.

Adult↗
PubMed1988

Clinical evaluation of the Pollenex BP-850 automatic sphygmomanometer.

Eighty subjects were assigned to two conditions in which readings of blood pressure were taken simultaneously by an observer using a Hawkesley Random Zero Sphygmomanometer and by a Pollenex BP-850 Automatic Sphygmomanometer either in its standard form or silenced to stop it bleeping whilst recording blood pressure. Forty subjects were assigned to a comparison group, where simultaneous readings by two observers were taken from one Hawkesley. Analyses performed included correlations, t-tests, and Bland and Altman's (Lancet, 1986, i: 307-310) differences against the mean method. Cues from observer behaviours or the bleeping Pollenex resulted in higher concordance between measures in the standard condition and the Hawkesley comparison condition. However, even in the silent condition the Pollenex proved to be as reliable a monitor of blood pressure as the Hawkesley.

Adult↗
PubMed1988

Effect of alcohol and glucose infusion on pituitary-gonadal hormones in normal females.

During 1 h, median 976 mmol ethanol in 5.5% glucose was administered i.v. to six healthy female volunteers (aged 26-37 years) in the luteal phase of the menstrual cycle. The median maximal blood ethanol concentration was median 33.5 mmol/l and serum ethanol concentrations of 2 mmol/l were reached after 8 h. Four of the women participated in a control experiment with infusion of an equal volume of glucose 5.5%. Venous blood samples were drawn 5 times during the 24-h follow up period. Serum concentrations of sex steroids and pituitary hormones decreased in both ethanol and control experiments and the results did not differ significantly. The lowest hormone concentrations were observed 1-5 h after the start of infusion. Oestradiol, oestrone and oestrone-sulphate concentrations decreased 24-46% compared to basal values. 5 alpha-dihydro-testosterone levels decreased 23-31%, androstenedione and dehydroepiandrosterone-sulphate levels decreased 6-48%, while testosterone levels did not change significantly. Prolactin concentrations were reduced by 41-51% of basal values and luteinizing hormone concentrations by 37-68% Follicle stimulating hormone levels did not change significantly. Stress factors or haemodilution are not likely explanations of the observed changes in hormone concentrations. A circadian rhythm could not explain changes in hormones of non-adrenal origin.

Adult↗
PubMed1988

Thyroid hormones and thyroxine-binding globulin in relation to liver function and serum testosterone in men with alcoholic cirrhosis.

In 73 euthyroid male patients with histologically verified alcoholic cirrhosis, thyroid hormones, thyroxine-binding globulin (TBG) and testosterone concentrations (total, non-protein- and non-SHBG-bound) were studied in relation to each other and to the degree of liver dysfunction. Serum concentrations of triiodothyronine (T3) decreased significantly (p less than 0.05) and thyroid-stimulating hormone (TSH) increased with progressing liver dysfunction. Serum concentrations of tetraiodothyronine (T4), TBG and T4/TBG ratio did not correlate significantly with liver function. Serum T3 concentrations correlated significantly (Kendall Tau-beta = -0.33, p = 0.001) with total serum testosterone concentrations, while there was a negative correlation (Kendall Tau-beta = -0.20, p = 0.025) between testosterone and TSH values. No correlation was found between testosterone concentrations and serum levels of TBG. It is proposed that the association between T3 and TSH on one hand and testosterone concentrations on the other reflects a covariation of these variables with liver function. The TBG level was normal in most patients and was not correlated to testosterone concentrations.

Adult↗
PubMed1988

Effect of oral testosterone treatment on serum concentrations of sex steroids gonadotrophins and prolactin in alcoholic cirrhotic men. Copenhagen Study Group for Liver Diseases.

The aim of this study was to examine the serum concentrations of sex steroids and pituitary hormones in a randomly selected group of alcoholic cirrhotic men participating in a randomized, placebo-controlled study on the efficacy of oral testosterone treatment on the liver. Before treatment, patients (n = 25) had median serum concentrations of testosterone, oestradiol, non-protein bound oestradiol, non-sex hormone binding globulin (SHBG) bound oestradiol and oestrone sulphate which did not differ significantly from those of healthy controls (n = 16), but the patients had significantly (P less than 0.01) higher median serum concentrations of oestrone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin. The patients were randomized to treatment with either oral micronized testosterone (200 mg t.d.s.) or placebo for a median duration of 1 year. In the placebo group (n = 8), hormone concentrations at follow-up were not significantly different from those at entry apart from a significant (P less than 0.05) increase in FSH concentrations. Median concentrations of testosterone, oestrone, and oestrone sulphate increased significantly (P less than 0.05) in the testosterone-treated group (n = 17) when compared with concentrations at entry and concentrations in the placebo group. The testosterone-treated group had significantly (P less than 0.05) higher serum concentrations of non-protein bound and non-SHBG bound oestradiol when compared with concentrations at entry, but no significant changes were observed regarding serum oestradiol and prolactin concentrations. Both LH and FSH concentrations decreased significantly (P less than 0.05) in the testosterone-treated group when compared with concentrations at entry and concentrations in the placebo group.

Adult↗
PubMed1988

The effect of oral testosterone on serum TBG levels in alcoholic cirrhotic men.

Seventy-three euthyroid male patients with alcoholic cirrhosis of the liver were randomly allocated to oral testosterone (200 mg t.i.d.) or placebo and followed for up to 36 months. Triiodothyronine (T3), tetraiodothyronine (T4), thyroxine binding globulin (TBG) and T4/TBG ratio were determined before entry and during follow-up. No significant differences were observed before entry or during follow-up between the two treatment groups. T3, T4 and T4/TBG ratio did not change significantly during follow-up, while TBG concentrations decreased (P less than 0.05). Using a multivariate test, it is demonstrated that testosterone treatment significantly reduced TBG concentrations in cirrhotic men with preserved liver function, like normal men, but not in patients with moderate liver dysfunction. The lack of effect of testosterone in patients with more advanced cirrhosis may be due to a decreased function of sex hormone receptors in their liver.

Administration, Oral↗
PubMed1988

A multi-disciplinary approach to the prevention of coronary heart disease.

The South Birmingham Coronary Prevention Project is described, in which health checks by practice nurses in GPs' surgeries are combined with direct patient access to a secondary referral system. Where appropriate, health check attenders are offered the choice of either counselling by the practice nurse, direct referral to their GP, or direct referral to secondary intervention, including dietary advice for patients with high serum cholesterol, stress management training for mild hypertension, and smoking cessation groups run by specialist workers. Further developments of the project may be toward increasing areas of nurses intervention, for example running lipid clinics, and combining with Look After Your Heart! in the workplace. Progress in each of these areas is described and discussed.

Coronary Disease↗
PubMed1987

Hypertension and indicators of coronary heart disease in Wallis Polynesians: an urban-rural comparison.

A comparative study of hypertension, and indicators of and risk factors for coronary heart disease was undertaken in samples of rural Wallisians of Wallis Island, and first generation Wallisian migrants in the urban centre of Noumea, New Caledonia. Approximately 20% of the adult population of the two communities was included in the study. Higher mean blood pressure and hypertension prevalence in Wallisians in Noumea compared to those in Wallis was documented. There was no significant rise in blood pressure with age in rural Wallisian males. Wallisians in Noumea tended to be more obese than those in Wallis (particularly females). Although differences in the extent of obesity appeared to explain some of the differences in blood pressure between populations of Wallis and Noumea, other environmental factors (such as salt intake) are probably important. There was a trend for a higher prevalence of Q wave changes on the ECG in urbanized Wallisians compared to their rural counterparts. There was no significant or consistent differences in plasma lipid concentrations between the two groups. The prevalence of diabetes was 7 and 4 times higher in Noumea compared to Wallis for males and females respectively. Differences in diabetes and hypertension prevalence are more likely to account for the variation in ischaemic heart disease than plasma lipid levels.

Adult↗
PubMed1987

Campylobacter jejuni enteritis associated with raw goat's milk.

During a three-week period in July 1983, six cases of Campylobacter jejuni enteritis in King County, Washington were associated with a dairy that produced raw goat's milk. Four patients consumed the dairy's milk, and the other two patients comprised an employee of the dairy and her infant son. Two case-control studies confirmed that, at the time the cases occurred, consumption of the dairy's milk was a risk factor for C. jejuni enteritis in King County. C. jejuni was isolated from the intestinal tract of three of the dairy's goats. Two of the three isolates, as well as those from five of the patients (all of those tested), were Lior serotype 36. That serotype was not encountered among 14 other C. jejuni isolates from King County during the period of the outbreak, including three isolates from goats at another inspected dairy. The study shows that raw goat's milk may transmit C. jejuni infection from animals to humans, as other investigators have shown for unpasteurized cow's milk.

Adolescent↗
PubMed1987

Androgens and oestrogens before and following oral testosterone administration in male patients with and without alcoholic cirrhosis.

Compared with controls (N = 9), alcoholic cirrhotic men (N = 14) showed: significantly (P less than 0.05) higher serum concentrations of sexual hormone binding globulin (SHBG), androstenedione, oestrone, oestradiol, non-protein bound oestradiol, and non-SHBG bound oestradiol; significantly (P less than 0.05) lower concentrations of albumin and non-SHBG bound testosterone; no significant differences regarding concentrations of testosterone, dihydrotestosterone, non-protein bound testosterone, oestrone sulphate, and SHBG bound oestradiol. Following oral administration of 400 mg of micronized testosterone, serum concentrations of testosterone, dihydrotestosterone, androstenedione, and oestrone increased significantly (P less than 0.05) in both groups, cirrhotic patients reaching significantly (P less than 0.01) higher concentrations than controls. Further, in the cirrhotic group, the serum concentrations of oestrone sulphate, oestradiol, non-protein bound oestradiol, and non-SHBG bound oestradiol, and the urinary excretion of oestrogen increased significantly P less than 0.05). In conclusion, peroral testosterone administration decreases the serum oestradiol/testosterone ratio in patients with normal livers as well as in patients with alcoholic cirrhosis, but the latter group obtains significantly higher oestrogen concentrations.

Administration, Oral↗
PubMed1986

The ultrastructural location of C-protein, X-protein and H-protein in rabbit muscle.

Purified antibodies to the thick filament accessory proteins, C-protein, X-protein and H-protein, have been used to label fibres of three rabbit muscles, psoas (containing mainly fast white fibres), soleus (containing mainly slow red fibres) and plantaris (a muscle of mixed fibre type) and their location has been examined by electron microscopy. These accessory proteins are present on one or more of a set of eleven transverse stripes about 43 nm apart that have been observed previously in each half A-band. Each protein has a limited set of characteristic distributions. H-protein is present on stripe 3 (counting from the M-line) in the majority of psoas fibres but is absent in soleus and plantaris muscle. C-protein can occur on stripes 4-11 (the commonest pattern seen in psoas); on stripes 5-11 (in psoas and plantaris); on stripes 3 together with stripes 5-11 (in plantaris); or on none (in red fibres of all three muscles). X-protein can occur on stripes 3-11 in the red fibres of all three muscles; on stripe 4 only (in psoas and plantaris); on stripes 3 and 4 (in psoas and plantaris) or on none. Stripes labelled with anti-X are wider than those labelled with anti-C and consist of a doublet with an internal spacing of 16 nm. The patterns for the three accessory proteins, while overlapping, are in no case identical; this suggests the proteins do not simply substitute for one another. The precise axial positions of the anti-C labelled stripes differ from those of the anti-X stripes; the anti-X stripes lie about 8-9 nm further from the M-line than the corresponding anti-C stripes. This implies that the inner member of an X-protein doublet lies in a very similar position to a C-protein stripe. The anti-H labelled stripe seen in most psoas fibres lies 14 nm nearer the M-line than stripe 3 of the anti-X labelled array in psoas red fibres and is staggered from a continuation of the C-protein array by about 4 nm. The labelling patterns were constant within a fibre and suggest a very precise assembly mechanism. The number of classes of fibre, as defined by the accessory proteins present and their arrangement, exceeds the number of fibre types presently recognized.

Animals↗
PubMed1986

Rapid changes in plasma androgens during insulin withdrawal in male type 1 (insulin-dependent) diabetics.

Plasma concentrations of testosterone, androstenedione and dihydrotestosterone were measured in 15 Type 1 (insulin-dependent) diabetics with (n = 8) and without (n = 7) B-cell function during 12 h of insulin withdrawal and compared with those of 8 normal subjects. Before insulin withdrawal no significant difference was found in androgen concentrations between the diabetic and the normal subjects. The normal diurnal profiles, with highest androgen concentrations in the morning before insulin withdrawal (08:00) and lowest concentrations at 20:00 h were maintained in the diabetics. However, testosterone and dihydrotestosterone concentrations were lower in the diabetics after 4 h of insulin withdrawal and remained so throughout the study. The concentrations of androstenedione were not significantly different between diabetics and normal subjects except after 4 h of insulin withdrawal. Despite the patients without B-cell function were more metabolically decompensated from after 4 h of insulin withdrawal compared with patients with B-cell function, no significant differences were found in androgen concentrations between the two groups although a tendency to lower concentrations were seen in the group without B-cell function.

Adolescent↗
PubMed1986

Serum steroid levels in intact and endocrine ablated BALB/c nude mice and their intact littermates.

An investigation was made of the serum steroid levels found in intact and endocrine ablated nude mice of both sexes and in their intact homozygous littermates. The results showed that nude mice have a normal steroidogenesis, but with decreased levels of circulating steroids compared to those of the littermates. The efficacy of the endocrine ablations was confirmed by the reduction in serum oestrone following oophorectomy, and by the reduction in serum testosterone and progesterone following orchiectomy. The normal steroidogenesis in nude mice, and the similarities between mouse and man with regard to changes in serum steroids following oophorectomy and orchiectomy, support the usefulness of human tumor xenograft models for the study of hormone-tumor interactions.

Animals↗
PubMed1986

Adrenergic modulation of the delayed rectifier potassium channel in calf cardiac Purkinje fibers.

We have investigated the modulation of the delayed rectifier potassium channel in calf cardiac Purkinje fibers by the neurohormone norepinephrine. We find that 0.5 microM norepinephrine increases this K channel current by a factor of 2.7. A maximal increase of about four was found for concentrations of 1 microM and above. Norepinephrine produced a small (less than 5 mV) and variable shift of the K channel reversal potential toward more negative values. The kinetics of the potassium channel are well described by a two-exponential process, both in the absence and presence of norepinephrine. However, norepinephrine substantially decreases the slower time constant with no significant effect on the fast time constant. Potassium channel activation curves in the presence of norepinephrine are very similar to control curves except at large positive potentials. A simple sequential three-state model for this channel can reproduce these data both with and without norepinephrine. The logarithms of the rate constants derived from this model are quadratic functions of voltage, suggesting the involvement of electric field-induced dipoles in the gating of this channel. Most of the kinetic effects of norepinephrine appear to be on a single rate constant.

Animals↗
PubMed1986

Fundamental voice frequency measured by electroglottography during continuous speech. A new exact secondary sex characteristic in boys in puberty.

The variation of fundamental voice frequency measured by the average of 2000 consecutive electroglottographic cycles in a reading situation has been examined in relation to pubertal development and androgens. Fundamental frequency among other parameters was related to height (r -0.82), pubic hair stage (r -0.87), testis volume (r -0.78), total testosterone (r -0.73) and serum hormone binding globulin (r 0.75). Single observations of fundamental frequency show a clear grouping of results under and over 200 Hz. Fundamental frequency of more than 200 Hz and serum testosterone of more than 10 nmol/l probably represent values for a boy in puberty. There seem to be comparable relations with other androgens and with serum hormone binding globulin.

Adolescent↗