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Biomedical subjects

D Weightman

Publications and source records attributed to D Weightman.

At least 19 recordsLinked to original sources
PubMed1989

Cross-reaction of eye muscle antibodies with thyroid tissue in thyroid-associated ophthalmopathy.

The nature of the association of ophthalmopathy with autoimmune thyroid disease is not understood. Serum autoantibodies to eye muscle have previously been identified and in this study we have explored the hypothesis that there may be shared antigenic determinants between orbital and thyroid tissues. Sera were obtained from patients in whom eye muscle antibodies (EMAb) had been detected by an enzyme-linked immunosorbent assay (ELISA); the sera were preincubated with membrane preparations of thyroid or eye muscle, hepatic membranes being used as control. Tissue-binding antibodies were removed from serum by centrifugation and the supernatant serum was analysed using an indirect ELISA and by immunoblotting. In the ELISA, all sera gave a positive response for EMAb. In one serum, the binding was entirely non-specific. All sera showed significant neutralization of EMAb by eye muscle. In six sera there was reduction of EMAb after exposure to thyroidal antigens, indicative of cross-reaction. Western blotting confirmed the non-specific nature of the binding in one serum. In five of the remaining nine sera, protein bands were identified which interacted specifically with eye muscle and, in two of these, the same determinants were neutralized by preincubation with thyroid tissue. The Western blots confirmed the findings in the ELISA. The determinants recognized by IgG were variable between patients and no common antigen could be identified. This study demonstrates that, in some cases of thyroid-associated ophthalmopathy, there is cross-reaction of EMAb with thyroidal antigens, but this is variable and not found in every case. This may explain the association of the disease with autoimmune thyroid disease, at least in some cases.

Autoantibodies↗
PubMed1985

Opiate receptor blockade and diurnal pituitary and adrenal hormone levels.

Peripheral pituitary hormone levels exhibit circadian variations though the mechanism of these changes is unknown. In order to investigate the possible role of endogenous opiates in such changes we have studied the influence of opiate receptor blockade with naloxone (6.8 mg) on pituitary hormones in the morning and again in the evening in six normal male volunteers. Basal ACTH, cortisol, aldosterone and prolactin were higher in the morning than in the evening. Following naloxone at 0700h both ACTH and cortisol rose indicating a tonic inhibition of ACTH by endogenous opiates at that time. At 2230h cortisol rose following naloxone but ACTH did not, suggesting that endogenous opiates do not play an important role in the diurnal rhythm of this hormone and consistent with the suggestion that endogenous opiates can effect cortisol levels independently of their action on ACTH. Neither aldosterone nor prolactin were influenced by naloxone. In contrast TSH was unaffected by naloxone in the morning but fell in the evening (mean + SE decrement over 120 min -0.6 +/- 0.3 mU/l as compared with the control +0.6 +/- 0.4 mU/l; p less than 0.01). Thus, endogenous opiates probably tonically stimulates TSH levels in the evening when TSH may increase and possibly play a role in the circadian rhythm of TSH.

Adrenal Cortex Hormones↗
PubMed1984

"Therapeutic" serum concentration of phenytoin: the influence of seizure type.

Serum phenytoin concentrations were monitored prospectively in 26 patients with previously untreated partial epilepsy, during monotherapy with phenytoin. Only six remained entirely seizure-free, although only four experienced further tonic-clonic seizures. There was no correlation between serum phenytoin concentrations and freedom from partial seizures in those patients in whom such seizures recurred. There did appear to be a correlation between serum phenytoin concentration and freedom from tonic-clonic seizures.

Adolescent↗
PubMed1983

Plasma concentrations of sodium valproate: their clinical value.

Plasma valproate concentrations were monitored prospectively in 54 previously untreated adult patients with epilepsy. Dose and plasma concentration were highly correlated. Adverse effects were common in association with plasma levels above 100 micrograms/ml. In patients suffering tonic-clonic seizures without focal symptoms, no seizures occurred when plasma levels were higher than 50 micrograms/ml. In patients with partial seizures, it was difficult to define a lower limit to a therapeutic range.

Clinical Trials as Topic↗
PubMed1983

A study of embolism in mitral valve disease and atrial fibrillation.

A number of possible risk factors, clinical, radiological, biochemical, and social have been examined in one group of 34 cases of mitral valve disease and four of lone atrial fibrillation, all of whom gave a history of embolism, and also in a group of 24 cases of mitral valve disease who gave no such history. All were on long-term anticoagulant treatment. Comparison of the two groups disclosed no features that would distinguish those who ran the greater risk of embolism from the remainder other than that the men in the former group were older and of shorter stature. At comparable age, the women with a history of embolism had smaller left atria. Examination of a special group of nine patients who had had embolism despite anticoagulant treatment also disclosed no special features, other than a greater age at the time of their first embolism. Fibrinolytic activity was less and the level of beta thromboglobulin was greater than normal in both groups. Those with proven risk of embolism were not distinguished by higher values of this platelet protein. Neither variable correlated with the type of heart disease. No positive association was found between cigarette smoking and the risk of embolism. Embolism was significantly more likely to occur between 0801 and 1600 hours than at other times of day.

Atrial Fibrillation↗
PubMed1982

Tizanidine in the treatment of spasticity.

A double-blind crossover trial compared tizanidine with baclofen in 36 patients with spasticity. Tizanidine appeared to reduce lower limb spasticity more effectively and to have fewer side effects, but no statistically significant differences emerged when the two drugs were compared. An additional open study of tizanidine confirmed the beneficial action in a selected minority of patients with spasticity. This drug may have an important role in the management of spasticity, but further studies are required.

Adult↗
PubMed1982

A comparison of phenytoin and valproate in previously untreated adult epileptic patients.

Eighty-eight patients with the onset of epilepsy in adult life were randomly allocated to treatment with sodium valproate (600 mg/day), or phenytoin (300 mg/day), and followed up for at least 12 months. Both drugs were highly effective in the control of tonic-clonic seizures, irrespective of whether they were accompanied by focal features, but were markedly less effective in the control of partial seizures. Two patients exhibited acute allergic reactions to phenytoin. No significant differences have yet emerged in the efficacy of the two drugs, and valproate may be considered as a "fist-line" anticonvulsant in the treatment of adult onset epilepsy.

Adolescent↗
PubMed1981

Placebo-controlled study of phenobarbitone and phenytoin in the prophylaxis of febrile convulsions.

Of 138 children who had a first febrile convulsion before their second birthday, 48 were treated with phenobarbitone, 47 with phenytoin, and 43 with a placebo for 12 months. Drug levels were monitored and adverse effects of the drugs were noted. Compared with placebo, phenobarbitone significantly reduced recurrences among children under 14 months old at the time of their first convulsion, but nor among older children. Phenytoin was an ineffective prophylactic agent. Ideal drug levels were difficult to maintain, and many recurrences occurred when concentrations were suboptimal. Behavioural disturbance in children taking phenobarbitone was not a serious problem. The decision to give continuous prophylaxis for febrile convulsions is complex, and each case must be judged on its merits. For children who have a first seizure before 14 months of age prophylaxis may be advisable and phenobarbitone is effective.

Age Factors↗
PubMed1981

Atopy does not predispose to RSV bronchiolitis or postbronchiolitic wheezing.

Twenty-six 8-year-old children who had had respiratory syncytial virus (RSV) bronchiolitis in infancy and their paired controls underwent skin and blood tests to assess the role of immunodeficiency and atopy in the pathogenesis of RSV bronchiolitis and the wheezing that may follow it. There was no difference between patients and controls in prevalence of atopy; positive results of prick tests to common antigens; eosinophil counts; yeast opsonisation defect; C2 deficiency; IgG, IgA, IgM, and IgE concentrations; or IgE antibody to dermatophagoides, timothy-grass pollen, and cat fur. Those of the children who had had RSV bronchiolitis and who continued to wheeze had a slightly higher mean eosinophil count and levels of IgE antibody to dermatophagoides than those who did not wheeze. Exercise-induced bronchial lability, though higher in patients than controls, did not correlate significantly with eosinophil counts or IgE concentrations. The genetic factors predisposing to RSV bronchiolitis and postbronchiolitic wheezing may differ from those predisposing to atopic asthma, though exclusive breast feeding may protect against both.

Bronchiolitis, Viral↗
PubMed1981

Altered dopaminergic regulation of thyrotrophin release in patients with prolactinomas: comparison with other tests of hypothalamic-pituitary function.

This study was carried out to test the hypothesis that sustained hyperprolactinaemia in patients with prolactinomas stimulates hypothalamic dopaminergic activity via a short loop positive feedback effect of prolactin (PRL). The intensity of dopamine (DA) effects on the pituitary around the adenoma was evaluated by measuring thyroid stimulating hormone (TSH) responses to intravenous injection of domperidone (10 mg) a new DA receptor blocking drug that does not penetrate the blood-brain barrier. TSH responses have been compared with those of PRL to the same agent. Eight females with prolactinomas showed greater TSH release after domperidone than nine normal females (sum of TSH increments over 20 min 17.5 +/- 1.7 v. 8.9 +/- 1.5 mu/l, P less than 0.001) whilst PRL release was reduced (sum of PRL increments over 120 min 5.9 +/- 2.4 v. 21.8 +/- 3.8 mu/l x 10(-3), P less than 0.01). Amongst nineteen hyperprolactinaemic females with apparently normal pituitary fossae (plain skull X-ray), ten showed an exaggerated TSH response (delta TSH, 4.2 +/- 0.6 mu/l, range 2.5-9.0 mu/1) and reduced PRL response to domperidone, comparable with established tumor cases. In the remaining nine normal fossa hyperprolactinaemic females, the TSH and PRL responses to dopaminergic were similar to normal females. These results support the initial hypothesis and indicate the coexistence of a defect in the dopaminergic inhibition of PRL release and increased dopaminergic inhibition of TSH release in patients with prolactinomas. The presence of an exaggerated TSH response to DA antagonism in a euthyroid, radiologically normal (plain skull X-ray), hyperprolactinaemic patient is compatible with the presence of an autonomously-functioning, PRL secreting, pituitary microadenoma and the TSH changes seen in these patients after DA antagonist administration can be readily detected by sensitive TSH radioimmunoassay.

Adenoma↗
PubMed1980

Beta-thromboglobulin in antecubital vein blood in relation to history of a stroke.

The levels of beta-thromboglobulin (BTG) have been measured in the blood of 22 male and 22 female elderly patients who gave a past history of stroke, and in 31 males and 88 females of comparable age who gave no such history. Comparisons were made within and between the groups. In the stroke patients the relationship between BTG and age was not significant for either sex, nor was there a difference between the sexes. In the BTG/time from stroke relationship the females showed significantly higher levels the longer the time that had elapsed since the stroke, and this could not be explained solely by the factor of ageing. For males, on the other hand, there was a non-significant fall in BTG with days from stroke. In 'normal' subjects the BTG/age relationship was significant in females but not in males. No significant differences were demonstrated between the BTG/age relationships between the stroke and control groups and this was true for both sexes. The potential value of estimations of BTG in the elderly is discussed.

Aged↗
PubMed1979

beta-thromboglobulin in antecubital vein blood--the influence of age, sex and blood group.

Samples of blood for estimation of beta-thromboglobulin (B.T.G.) in normal subjects have been obtained both from blood donors at the end of their donation and from other volunteers by standard venepuncture. The former was a satisfactory method in males only. By standard venepuncture females have on average lower values than males and in the pre-menopausal age groups the difference is statistically significant. Mean values vary little up to 59 years after which they rise slowly but steadily. There is no significant difference in the mean B.T.G. values between the ABO blood groups.

ABO Blood-Group System↗
PubMed1979

Rectal paracetamol in small children with fever.

37 febrile children aged between 3 months and 6 years were treated with paracetamol in a dose of 15--20 mg/kg by either oral elixir or rectal suppository. The rectal route was found to have an equal antipyretic effect and offers a practical alternative in those children for whom the oral route is not possible.20

Acetaminophen↗