PubMed Health⌕ Search

Biomedical subjects

J W Delahunt

Publications and source records attributed to J W Delahunt.

At least 19 recordsLinked to original sources
PubMed1999

Naturally occurring osteoarthritis in the metacarpophalangeal joints of wild horses.

This study identified changes consistent with osteoarthritis; articular cartilage damage, subchondral bone sclerosis and marginal osteophytes, in the metacarpophalangeal joints of wild New Zealand horses. The articular cartilage lesions were identified by Indian ink staining techniques and histology. The lesions occurred on the proximodorsal aspect of the first phalanx (P1) and were more severe on the medial compared to the lateral eminence of the bone, and their severity increased with age. The bone mineral density of the subchondral bone underlying the cartilage lesions, assessed using conventional radiography and dual energy absorptiometry, also increased with age and with severity of the overlying cartilage lesion. Subjective assessment of cabinet radiographs revealed that the subchondral bone sclerosis was greater in horses with severe articular cartilage damage. Ossicles, with a distinct trabecular bone pattern, were identified at the proximo-dorsal margin of P1 in 8 specimens from 5 horses from the older age groups (greater than age 5 years). The results of this study demonstrate age-related changes consistent with osteoarthritis in the metacarpophalangeal joints of wild horses. There appears to be a significant relationship between subchondral bone sclerosis and overlying cartilage degeneration in the proximodorsal aspect of P1. We have identified an age-related osteoarthritic process naturally present in horses; and postulate that the stresses of racing and training may accelerate this ageing process.

Absorptiometry, Photon↗
PubMed1998

A randomized trial of short-term treatment of Graves' disease with high-dose carbimazole plus thyroxine versus low-dose carbimazole.

OBJECTIVE: The optimal treatment regimen with thionamide drugs remains a matter for debate. We have investigated whether high doses of carbimazole, when compared with low doses, reduce relapse rates of Graves' disease. DESIGN: In an open label, randomized, prospective trial of treatment of Graves' disease we compared high doses of carbimazole (6 months of 100 mg carbimazole per day plus thyroxine) to low-dose carbimazole treatment (starting at 25 mg and titrating the carbimazole dose with the aim to maintain serum thyroid function test results within the normal reference range). PATIENTS: Thirty-seven patients with a first episode of Graves' disease were enrolled. MEASUREMENTS: During the 6 months of treatment we evaluated the rate of normalization of serum thyroid function tests, changes in serum thyroid auto-antibody levels and the rate of side-effects during treatment. After completion of the 6-month treatment course patients were observed for 2 years for evidence of relapse of Graves' disease. RESULTS: There were no differences between the two groups either in the rate of normalization of serum thyroid function tests or in serum thyroid auto-antibody levels during treatment. Of the 17 patients randomized to high-dose treatment seven suffered treatment side-effects, compared to only one of the 20 patients receiving low-dose treatment (P < 0.006). There was no significant difference in 2-year post-treatment remission rates on an intention-to-treat basis between the two treatment groups (18.7% vs. 5.9%, P = NS). However, for those patients who completed 6 months of treatment (high-dose group = 9, low-dose group = 16), multivariate survival analysis demonstrated a significantly longer median relapse-free interval (P < 0.04) in the high-dose group (27 weeks; 25th percentile: 9.6 weeks, 75th percentile: 75 weeks) versus the low-dose group (6 weeks; 25th percentile: 4.8 weeks, 75th percentile: 13.1 weeks). CONCLUSIONS: High-dose carbimazole treatment delays, but does not prevent, relapse from Graves' disease in those patients able to tolerate the treatment. However, it leads to more frequent side-effects than conventional dose treatment.

Adult↗
PubMed1995

Lack of evidence for pituitary thyrotroph down-regulation after 1 week of oral thyrotrophin-releasing hormone and metoclopramide under conditions of constant peripheral thyroid hormone levels.

We investigated the pituitary thyrotrophin (TSH) response to repeated oral (non-pulsatile) thyrotrophin-releasing hormone (TRH) administration and potential modifying effects of dopamine antagonist treatment under conditions of constant peripheral thyroid hormone levels. In a randomized double-blind crossover trial, seven hypothyroid subjects, euthyroid on L-thyroxine, received 1 week each of oral TRH (40 mg, 12 hourly) plus metoclopramide (10 mg, 8 hourly) and TRH (40 mg, 12 hourly) plus placebo (one capsule, 8 hourly). At the beginning and end of each treatment period five samples of blood for estimation of serum TSH were taken over 1 h before ("baseline") and seven samples over 2 h after the treatment combination was given ("stimulated"). Serum free thyroxine, free triiodothyronine and prolactin levels also were measured. Mean log10 +/- SEM (log10 mIU/l) "baseline" serum levels TSH were -0.177 +/- 0.183 (median 0.345 mIU/l (untransformed); range (r) 0.03-10.11 mIU/l; first quartile (1q) 0.22 mIU/l; third quartile (3q) 2.48 mIU/l) before and 0.182 +/- 0.107 (median 1.385 mIU/l; r = 0.45-19.8 mIU/l; 1q = 0.9 mIU/l; 3q = 1.78 mIU/l) after 1 week of treatment (p < 0.02). There were no significant differences between oral TRH plus metoclopramide and oral TRH plus placebo. Peripheral thyroid hormone levels and the "stimulated" TSH response (expressed as area under curve after TRH and metoclopramide or placebo; min.log10 mIU/l) remained unchanged after 1 week. In the absence of changes in peripheral thyroid hormone levels, oral TRH over 1 week may not result in down-regulation of anterior pituitary thyrotrophs.2+ f2p4

Administration, Oral↗
PubMed1994

Serum enzymes in hypothyroidism.

AIM: To report three cases of hypothyroidism detected because of unexplained elevation of serum enzyme levels on biochemical testing. METHODS: Clinical details and serum enzyme results were obtained before and after L-thyroxine (T4) replacement therapy. RESULTS: The three patients all had serum creatine kinase (CK) levels > 2000 U/L, aspartate aminotransferase (AST) > 90 U/L, and lactate dehydrogenase (LD) > 300 U/L at presentation, with these levels being 10-15, 2-6, and 2-3 times the upper reference limits respectively. CK isoenzyme determination was consistent with skeletal muscle origin. Thyroid function tests performed after consultation with the clinical biochemist confirmed the biochemical diagnosis of primary hypothyroidism. A rapid fall toward normal serum enzyme levels occurred in response to T4 replacement therapy. CONCLUSIONS: Although serum enzymes are an integral part of both the liver and cardiac profiles provided by laboratory, they are not organ specific, and changes may reflect dysfunction elsewhere in the body. Elevations of serum CK (and other muscle enzymes) may occur in hypothyroid subjects, the cause of which has not been established. The clinical diagnosis of hypothyroidism requires a high index of suspicion and should be considered in patients with unexplained persistent elevations of serum muscle enzymes.

Adult↗
PubMed1993

Hirsutism. Practical therapeutic guidelines.

Hirsutism is the transformation of fine vellus hair to visible, thickened terminal hair under androgenic stimulus. The most common causes of hirsutism are familial, idiopathic or polycystic ovarian disease. Patient distress is the prime indication for therapy. Drug treatment should be continued for 12 months before assessing response. Spironolactone is generally the drug tried first. Ovarian hormones, e.g. medroxyprogesterone acetate plus ethinylestradiol, or cyproterone acetate plus ethinylestradiol may be added if response is inadequate.

Female↗
PubMed1992

Treatment of extensively invasive (giant) prolactinomas with bromocriptine.

We report four cases of extensively invasive giant prolactinomas. No tumour was suitable for total or near total resection because of invasion into surrounding bone. All had undergone radiotherapy prior to dopamine agonist therapy. Prolactin levels were between 103,000 mlU/L and 1,700,000 mlU/L at presentation, but all tumours responded to bromocriptine therapy and prolactin levels fell into the normal range in three patients within two to 24 months. The fourth patient's level fell to just above the reference range (700 mlU/L) within 36 months. None of the patients has died of their pituitary tumour or related complications to date. Giant prolactinomas appear to be exquisitely sensitive to treatment with bromocriptine. The role of radiotherapy is unclear, but it might contribute to long term control. Surgery should be limited to control of local complications.

Adult↗
PubMed1992

Predictors of osteopenia in premenopausal women with anorexia nervosa.

The study retrospectively evaluated risk factors for osteopenia in anorexia nervosa (AN) patients. Sixty-nine outpatient, female anorexia nervosa patients (age range 20-40 years, mean 27.5) at varying stages of recovery, and 31 controls had lumbar spine trabecular bone density assessed with single energy computed tomography (CT) scans. An investigator-based, semistructured interview assessed weight and menstrual histories from age 10. Current exercise and dietary calcium levels were categorized and lifetime durations in categories were estimated for each subject. Bone density was significantly lower in the patient group (mean 120 mg/cm3) than in the controls (mean 148 mg/cm3, P less than 0.001). Bone density correlated significantly with duration of illness, amenorrhea, and weight histories but not with measures of dietary calcium or exercise histories. The most important predictor of bone loss on stepwise multiple regression analysis was duration of AN (23% of variance, P less than 0.001), and duration of an inadequate calcium intake in adolescence explained a further 5% of the variance (P = 0.052). There was no evidence that regular exercise and adequate dietary calcium prevented bone loss related to prolonged periods of low weight and amenorrhea in these subjects.

Adult↗
PubMed1991

The management of Graves' disease in New Zealand: results of a national survey.

OBJECT: to compare treatment of Graves' disease in New Zealand with treatment in Europe and the United States of America (USA). METHODS: we circulated a questionnaire used in recent surveys in Europe and USA to all specialist physicians in New Zealand registered with the Medical Council. In the questionnaire a patient with uncomplicated Graves' disease was given as an index case, followed by eight clinical variations with regard to goitre size, severity, sex, age and previous treatment. RESULTS: two hundred and ninety-six (79%) out of 374 physicians responded to a preliminary letter asking whether they would be willing to participate in the survey. Of the respondents 71 (24%) saw more than two patients with Graves' disease per year and were included in the analysis (186 saw fewer than two cases per year and 39 failed to return questionnaires). For the index case, 55% of New Zealand respondents would treat with antithyroid drugs, 41% with radioiodine and 4% with surgery. For the index case and its variations the use of radioactive iodine by New Zealand physicians was greater than their European, but less than their American, counterparts. Surgery was infrequently recommended in any of the countries except for the patient with a large goitre, for whom 24% of New Zealand and 51% of European respondents would recommend subtotal thyroidectomy. CONCLUSION: we have demonstrated a spectrum of behaviour by physicians in the treatment of Graves' disease based on infrequent use of surgery and the willingness to use radioactive iodine instead of treatment with antithyroid drugs. New Zealand physicians appear to be more conservative in the use of radioiodine than their American, but less than their European counterparts.

Adult↗
PubMed1991

Once daily, low dose, short term antithyroid drug treatment of Graves' disease is followed by an unacceptably high relapse rate.

Thirty-six patients with hyperthyroid Graves' disease were treated with low doses of antithyroid drugs until thyroid function test results indicated euthyroidism or mild hypothyroidism (median treatment period three months, range 1.5-8 months). Less than one-half (42%) of the patients remained hyperthyroid after two months of treatment, but 21% were still thyrotoxic after three months of treatment. Of 32 patients who completed treatment and entered the observation period after treatment was withdrawn, 27 (84%) have relapsed, two have remitted for one year or more and three have been followed for less than one year without relapse. Although once daily, low dose, short term antithyroid drug treatment of patients with Graves' disease in the Wellington area satisfactorily controls the hyperthyroidism in the majority of cases, it is followed by an unacceptably high relapse rate.

Adolescent↗
PubMed1990

Serum forms of testosterone in men after an hCG stimulation: relative increase in non-protein bound forms.

A postulated function of steroid binding proteins in serum is to smooth changes in steroid levels. To test this, testosterone levels in six normal men were increased by injecting 6000 IU hCG i.m., and changes in serum forms of testosterone were measured. Blood was collected every 10 min for 2.5 h and then once a day for 4 days. By day 4 the mean serum testosterone level had risen to 178% +/- 13% (SEM) of a mean basal level (first five samples). This rise was less than that in free testosterone (221% +/- 18%), which was in turn less than the rise in the non-SHBG-bound fraction (255% +/- 19%). The concentrations of SHBG and albumin were constant. Thus, two putative bioactive fractions of testosterone, the free and non-SHBG-bound, increased to a greater extent than did total testosterone. Because the binding protein concentrations were constant, this implies they may act not as a buffer, but as an enhancer of active testosterone over this time interval.

Adult↗
PubMed1990

Do thermoregulatory reflexes pass through the hypothalamus? Studies of chronic hypothermia due to hypothalamic lesion.

A 38-year-old man presented with chronic hypothermia. He also had evidence of hypothalamo-pituitary dysfunction and CT scans showed a discrete hypothalamic lesion. Thermoregulatory impairment was found although there was normal circulatory control of blood pressure. Reflex vasodilatation could be initiated when hypothermia was present and also in response to raised body temperature. Shivering was initiated reflexly but did not otherwise occur. These observations imply that thermoregulatory reflexes are independent of central thermoregulatory mechanisms and do not pass through the hypothalamus.

Adult↗
PubMed1989

Investigation of osteopaenia in anorexia nervosa.

Sixty-nine female patients, mean age 27.5 years (range 20-40), with a past or current history of anorexia nervosa (DSM III-R) had spinal trabecular bone density assessed by single energy quantitative CT scan. Current exercise and dietary calcium levels were assessed by detailed questionnaires and categorized. A semi-structured interview was used to record weight, menstruation, exercise and dietary calcium intake histories from early adolescence. Serum sex hormones and total calcium assays were measured. Bone density was significantly lower in the patients compared to 31 controls. Bone density was significantly positively correlated with body mass index, and negatively correlated with illness duration and duration of amenorrhoea. Exercise levels, dietary calcium intake and taking an oestrogen pill did not correlate significantly with bone density. Recovered patients did not have osteopaenia but they had shorter illness histories than non-recovered patients. Management to minimise bone loss should focus on weight gain and resumption of normal menstruation.

Adult↗
PubMed1988

Mean platelet volume is increased in hyperthyroidism.

In 28 unselected patients with hyperthyroidism, platelet count, platelet hematocrit, mean platelet volume, and platelet distribution width were measured at the time of presentation and again when the patients were euthyroid. On return to the euthyroid state, there were highly significant falls in the mean values of the mean platelet volume (16% decline, P less than 0.001) and the platelet hematocrit (16% decline, P less than 0.001) and a slight but highly significant increase in the mean value of the platelet distribution width (2% increase, P less than 0.01). A decline in mean platelet volume was observed in 24 of 28 patients (86%); three patients showed no change. There was no significant change in the mean value of the platelet count. The observed effects of thyrotoxicosis on platelets appeared to be largely independent of the well-known effects on erythrocytes and white blood cells. An increase in mean platelet volume is a regular feature of hyperthyroidism that has not previously been described.

Adult↗
PubMed1987

Resolution of acromegaly after removal of a bronchial carcinoid shown to secrete growth hormone releasing factor.

A 29 year old woman with an enlarged pituitary fossa and classical acromegaly, possibly present for ten years, had biochemical and partial somatic resolution of the disorder after removal of a bronchial carcinoid tumour. In addition, galactorrhea stopped, menstruation returned after two years, and amenorrhea and elevated prolactin levels fell towards normal. Immunocytochemistry showed numerous growth hormone releasing factor (GRF) staining cells in the tumour. The tumour cells, when cultured, produced a supernatant selectivity stimulating human pituitary somatotrophic cell cultures to produce growth hormone (GH). The bronchial carcinoid did not secrete detectable GH, but extracts of it, and preoperative serum contained GRF immunoreactivity which coeluted with synthetic human pancreatic GRF.

Acromegaly↗
PubMed1986

The relationship of anxiety and depression to symptoms of hyperthyroidism using operational criteria.

Twenty-six females and seven males with newly diagnosed, untreated hyperthyroidism were administered a structured questionnaire designed to identify anxiety and depression using operational criteria. By DSM III criteria, 10 patients were found to have depression and 15 anxiety. The number of anxiety symptoms paralleled the number of hyperthyroid symptoms whereas depressive symptoms did not. Prior history of psychiatric disease and family history of psychiatric disease did not predict anxiety or depression in patients with hyperthyroidism. The number with depression and anxiety was felt to be artificially inflated by the concurrent presence of somatic thyroid symptoms. Psychiatric practitioners should be careful to exclude patients with hyperthyroidism before a primary psychiatric diagnosis is made.

Adult↗
PubMed1985

Dexamethasone suppression test as a simple measure of stress?

Non-suppression of cortisol by dexamethasone has been described as a biological marker of a diagnostic subgroup of depressed patients. This paper presents the hypothesis that the degree of non-suppression is a variable that reflects the quantity of stress or distress experienced by the patient rather than relating to a specific diagnosis. Such a quantitative measure of stress would be valuable for research in general medicine as well as in psychiatry. Testing of this postulate should apply a more precise interpretation of endocrine principles than has been applied to the dexamethasone suppression test to date.

Depression, Chemical↗