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Biomedical subjects

I Laing

Publications and source records attributed to I Laing.

At least 55 records · Page 3Linked to original sources
PubMed1986

Chemiluminescent labeled-antibody assay for thyroxin in serum, with magnetic separation of the solid-phase.

A chemiluminescent labeled-antibody immunoassay has been developed for measurement of total thyroxin (T4) in serum. Monoclonal antibodies to T4 labeled with a chemiluminescent acridinium ester are used. Serum samples are incubated with the labeled antibodies and a thyroxin-rabbit immunoglobulin conjugate, then reacted with magnetizable particles containing sheep anti-rabbit immunoglobulin. The total reaction time is 40 min. The chemiluminescence intensity of the solid-phase immune complexes is inversely proportional to the concentration of T4 in the sample. The sensitivity of the assay is 1 nmol/L, and the working range of 20-190 nmol/L is characterized by CVs less than or equal to 10%.

Animals↗
PubMed1985

Isolated adrenocorticotrophin deficiency and empty sella associated with hypothyroidism.

A case of isolated ACTH deficiency is described. The patient had an empty sella and longstanding radio-iodine induced hypothyroidism. The association between isolated ACTH deficiency, empty sella and hypothyroidism is reviewed. It has not previously been recognized that the commonest endocrine association of isolated ACTH deficiency is primary thyroid failure. ACTH secretion does not recover following thyroxine replacement treatment.

Adrenocorticotropic Hormone↗
PubMed1984

High serum thyroxine-binding globulin--an important cause of hyperthyroxinaemia.

Four patients are described who had a significant elevation of serum thyroxine-binding globulin (TBG). Review of these patients indicated that inappropriate therapy for thyrotoxicosis had been given in three cases. A study of our laboratory records revealed that significant TBG elevation was a relatively common phenomenon which occurred in approximately 0.45% of our hospital population. Patients with this abnormality have serum thyroxine levels which are comparable to those with clinical thyrotoxicosis. Tri-iodothyronine is frequently elevated though less so than in patients with clinical thyrotoxicosis. Measurement of TBG is indicated in all cases of hyperthyroxinaemia in which the clinical features of thyrotoxicosis are doubtful. The TRH test was found to be most useful in evaluating the thyroid status of these patients.

Adult↗
PubMed1984

Hyperkalaemia in diabetes mellitus--potential hazards of coexisting hyporeninaemic hypoaldosteronism.

Two patients with insulin-dependent diabetes mellitus (Type I), developed severe, life-threatening hyperkalaemia, the first following treatment with spironolactone, the second during treatment for staphylococcal septicaemia when glucose-induced hyperkalaemia occurred. Investigations demonstrated co-existing hyporeininaemic hypoaldosteronism. Prompt recognition of this combined hormone-deficiency syndrome led to appropriate treatment and recovery. The biochemical features and clinical importance of hyporeninaemic hypoaldosteronism are discussed.

Adult↗
PubMed1984

The preparation and characterization of alkaline phosphatase-thyroxine conjugates and their use in the enzyme immunoassay of thyroxine.

Alkaline phosphatase from calf intestine was conjugated to thyroxine using cyanuric chloride, glutaraldehyde and 1-cyclohexyl-3(-2 morphoinoethyl)-carbodiimide as coupling reagents. The conjugates produced were studied for incorporation of thyroxine, retention of enzyme activity and immunoreactivity in a thyroxine radioimmunoassay system against a range of thyroxine antisera. The use of these conjugates in thyroxine enzyme immunoassay was studied using second-antibody separation. Comparison of the results with radioimmunoassay data was satisfactory and indicates the potential of these conjugates for thyroxine immunoassay. The use of cyanuric chloride as a coupling reagent was unsatisfactory, but good results were obtained with glutaraldehyde. Although satisfactory immunoreactivity of carbodiimide conjugates was observed in a radioimmunoassay system, these results were not reflected in the enzyme immunoassay systems studied.

Alkaline Phosphatase↗
PubMed1983

Endocrine abnormalities in idiopathic haemochromatosis.

Anterior pituitary functions and sex steroid levels were measured in 12 patients with idiopathic haemochromatosis (eight males, four postmenopausal females) and age-matched controls, 12 with diabetes mellitus and five with hepatic cirrhosis. In idiopathic haemochromatosis gonadotrophin deficiency was present in seven of 12 patients including six of seven patients who had clinical evidence of hypogonadism. Basal prolactin levels were significantly lower in the patients with idiopathic haemochromatosis compared with either of the control groups (p less than 0.02). Nine patients with idiopathic haemochromatosis exhibited subnormal prolactin responses to thyrotrophin releasing hormone. Thyroid and adrenocortical functions were normal in all patients with idiopathic haemochromatosis. Testosterone values were subnormal in five of eight males with idiopathic haemochromatosis; females with idiopathic haemochromatosis had significantly lower testosterone values compared with the diabetic females (p less than 0.05). Oestradiol values in both sexes and sex hormone binding globulin values in the males were not significantly different in patients with idiopathic haemochromatosis compared with the controls. Sex hormone binding globulin levels were significantly higher in females with idiopathic haemochromatosis compared with either diabetic or cirrhotic females (p less than 0.05). Impairment of anterior pituitary function occurs in idiopathic haemochromatosis but is selective; gonadotrophin and prolactin deficiencies are common. Clinical hypogonadism is usually hypogonadotrophic in origin.

Aged↗
PubMed1982

Atopy predisposing to acute bronchiolitis during an epidemic of respiratory syncytial virus.

Thirty-one infants admitted to hospital with acute bronchiolitis during an epidemic of respiratory syncytial virus were compared with a control group of 32 infants to establish whether the two groups differed in atopic background. Past history of respiratory illness, eczema, and present reactions to skin testing differed significantly between the two groups. Thus, infants with acute bronchiolitis had a significantly higher atopic predisposition than the controls.

Bronchiolitis, Viral↗
PubMed1982

Hypermineralocorticism without excessive aldosterone secretion: an adrenal carcinoma producing deoxycorticosterone.

A 51-year-old female was thought to have Conn's syndrome because she had hypertension, hypokalaemia and low plasma renin activity. The cause was not aldosterone excess, but there was an adrenal cortical carcinoma producing 11-deoxycorticosterone (DOC) in extremely large quantities, with ineffective 11 beta-steroid hydroxylation. Plasma and urinary aldosterone levels were within the normal range. Blood levels of other steroids including those on the pathways of formation of glucocorticoids and sex steroids were unaffected. The tumor was cultured in vitro and shown by high performance liquid chromatography (HPLC) to produce predominantly DOC from tritiated pregnenolone, with no detectable aldosterone, in agreement with the in vivo results.

Adrenal Cortex Neoplasms↗
PubMed1982

Pregnancies in women with hyperprolactinaemia: obstetric and endocrinological management of 50 pregnancies in 37 women.

Fifty pregnancies occurred in 37 women with hyperprolactinaemia. Thirty women (81%) initially attended with infertility and 24 (65%) had secondary amenorrhoea. Twelve women (31%) had pituitary macroadenomas, of whom seven (19%) were treated with neurosurgery and/or external radiotherapy before conception. Forty-one conceptions (82%) followed treatment with bromocriptine. There were no unusual obstetric or endocrinological complications. Serum prolactin measured at least 6 months post partum when under basal conditions, without bromocriptine and not breast feeding, showed no significant trends compared with initial values. Tumour growth was not stimulated by the high oestrogen levels of pregnancy.

Adolescent↗
PubMed1982

A ligand-binding assay for thyroxine-binding globulin based on polyethylene glycol separation.

A simple ligand-binding assay for thyroxine-binding globulin (TBG) is described. The method depends on the partition of labelled thyroxine between bovine serum albumin and TBG. Differentiation between labelled thyroxine bound to TBG and bovine serum albumin is achieved by the addition of excess TBG antiserum and subsequent precipitation with polyethylene glycol. The results are compared with the Corning Immophase kit method for TBG.

Humans↗
PubMed1981

Rapid non-invasive diagnosis of herpes encephalitis.

A sensitive and specific radioimmunosorbent assay for serum and cerebrospinal fluid (CSF) IgG antibodies against Herpesvirus simplex has been evaluated as an early diagnostic test for herpes encephalitis. When combined with the measurement of albumin in serum and CSF as accurate diagnostic index was obtained in twenty-four out of twenty-six patients. Out of ten patients tested before day 10 of neurological illness, five had positive diagnostic indices. Three patients with negative indices before day 10 had positive indices when re-tested later.

Antibodies, Viral↗
PubMed1981

A correlative study of computed tomography and histology in human and experimental vasogenic cerebral edema.

The computed tomography (CT) scans of nine patients with vasogenic cerebral edema and five monkeys with cryogenic lesions were correlated with histologic findings. The areas of diminished density on the CT scan corresponded to foci of histologically recognizable edema. The attenuation number of the edematous tissue in the human varied from 18.0 to 28.8 Hounsfield units (HU: 1,000 scale) and in the monkey from 27.0 to 34.7 HU. There was a rough correlation between the extent of decrease in the attenuation number and the degree of staining of edematous tissue by the periodic acid-Schiff method. The decreased attenuation number of edematous tissue signifies dilution by edema fluid only when it is above 20 HU or represents a change of less than 12 HU. Lower numbers imply an additional process, possibly transformation of complex into neutral lipids. It is our belief that cerebral edema in the human can be quantitatively studied with the presently available CT scanners.

Adult↗
PubMed1980

Twenty-four hour profiles of serum prolactin during male puberty with and without gynaecomastia.

Twenty-four hour profiles of circulating prolactin have been documented in eight boys with simple delayed puberty, eleven with gynaecomastia, three of whom were retested following its spontaneous resolution, and two normal adult men. Mean 24 h prolactin levels in four boys with delayed puberty and ten with gynaecomastia exceeded the mean levels for the two adult men. A sleep-associated rise in prolactin levels occurred at all stages of puberty irrespective of the presence or absence of gynaecomastia, and in some subjects peaks also occurred during the daytime. Boys with gynaecomastia had higher 24 h means levels of prolactin (P less than 0.05), higher daytime levels (P less than 0.05) and higher sleep-associated levels (P less than 0.05) than did control subjects. These were not related to the degree or duration of the gynaecomastia, but 24 h mean levels of prolactin and oestradiol were positively correlated. In one subject who had had transient galactorrhoea, high levels of circulating prolactin, oestrone and oestradiol fell following spontaneous resolution of the gynaecomastia. We believe that oestrogen: androgen imbalance during the daytime is the major cause of pubertal gynaecomastia, with hyperprolacinaemia (which may cause galactorrhoea) sometimes occurring as a response to relative hyperoestrogenaemia.

Adolescent↗
PubMed1978

A simplified radioimmunoassay procedure for serum progesterone.

A simple, rapid radioimmunoassay for progesterone in unextracted serum is described. Cortisol is used to inhibit progesterone binding to corticosteroid binding globulin. The method has been optimised for the determination of progesterone in pregnancy sera or in the luteal phase of the menstrual cycle.

Female↗