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Biomedical subjects

K Hall

Publications and source records attributed to K Hall.

At least 289 records · Page 16Linked to original sources

Somatomedin A levels in patients with Cushing's disease.

The serum levels of immunoreactive somatomedin A (SMA) in 23 patients with Cushing's disease, aged 6-61 years, were within the range of healthy subjects for their ages. No correlation was found between SMA and the excretion of cortisol. After im administration of hGH (8 IU = 4 mg) daily for 3 days there was a significant rise in SMA, both determined by radioimmunoassay and radioreceptor assay. Thus no impairment was found in the GH-dependent SMA levels or the ability of hGH to generate somatomedin, which indicates that the growth retarding effect of cortisol is most likely due to a direct effect on the tissue. After treatment with stereotactic radiation to the hypophysis there was a significant decrease in cortisol excretion without any change in SMA levels, indicating the possibility to achieve a selective impairment of the ACTH-cortisol axis.

Adolescent↗

Cell-surface immunoglobulin and insulin receptor expression in an EBV-negative lymphoma cell line and its EBV-converted sublines.

Membrane Ig and insulin receptors were assayed in the EBV-negative Ramos lymphoma line and its EBV-converted sublines by surface fluorescence. 125I-protein A-binding assay, immunoprecipitation, and insulin receptor assay. The original Ramos line expressed surface IgM but not IgD and had a low concentration of insulin receptors. Ten of 10 converted lines expressed IgD and a variable but usually high insulin-binding capacity. Molecular weight analysis of immunoprecipitated Ig showed the presence of 2 mu-chains and 2 delta-chains. One of each heavy chain type could be characterized as membrane Ig, whereas the other was cytoplasmic. Antisera against the lambda-chain precipitated mu and delta heavy chains as well, indicating that the delta-chain expressed on the membrane of the EBV-converted Ramos lines is bound to the lambda light chain. The results show that the differentiation of a Burkitt lymphoma line is not completely "frozen" and can be induced to change in a more "activated" direction by EBV conversion.

Binding Sites↗

Plasma ACTH in patients with bronchogenic carcinoma.

Immunoreactive ACTH before and five hours after administration of 2 mg of dexamethasone was determined in patients examined in hospital for abnormalities on chest X-ray. Thirty patients had primary bronchial cancer, 15 had other lung conditions, mostly inflammatory infiltrations. The mean total ACTH and ACTH after dexamethasone suppression were significantly higher in the patients with bronchial cancer than in patients with other lung lesions or healthy controls. ACTH in plasma after administration of glucocorticoids was predominantly big ACTH. Several of the cancer patients had, however, ACTH levels within the same range as the other subjects. These results indicate that plasma ACTH determinations are of limited value as tumour markers for the detection of lung cancer although it is still possible that repeated sampling in patients with elevated ACTH levels may be of value when monitoring the therapy.

Administration, Oral↗

Hyperinsulinaemia in hyperprolactinaemic women.

The metabolic sequelae of hyperprolactinaemia were studied over a 12 h period of normal meals and activity in nine young females hyperprolactinaemic subjects and fourteen matched controls. In the patients, fasting blood glucose and serum insulin concentrations were normal, as was the blood glucose response to meals; the insulin rise with meals was, however, exaggerated and hyperinsulinaemia persisted throughout the day (mean +/- SEM 12 h serum insulin, 26 +/- 8 vs. 16 +/- 9 mu/l, P < 0.01). Blood lactate, pyruvate and alanine response to meals was also increased. Blood glycerol (mean 12 h blood glycerol 0.06 +/- 0.01 vs. 0.09 +/- 0.01 mmol/l, P < 0.01) and blood 3-hydroxybutyrate (mean 12 h blood 3-hydroxybutyrate 0.03 +/- 0.01 vs. 0.05 +/- 0.01 mmol/l, P < 0.05) concentrations were lower in hyperprolactinaemic subjects. There was a strong negative correlation between mean insulin and mean 3-hydroxybutyrate levels in the afternoon period (rs = -0.92, P < 0.01). Excess circulating prolactin in young female is associated with normoglycaemic hyperinsulinaemia. The changes in blood metabolite levels observed are probably secondary to the increased insulin concentrations.

Adult↗

Metrizamide cisternography in pituitary and juxtapituitary lesions.

Seventy-five suprasellar metrizamide cisternograms were obtained, 25 in normal individuals who had had cervical myelography and 50 in patients with pituitary or juxtapituitary lesions. The technique accurately delineates a suprasellar extension of a small or moderate-sized pituitary lesion and usually shows its relationship to the optic chiasm. Large suprasellar masses, however, are not well visualized. 'Empty sellae' are readily demonstrated and have a high incidence in both normal individuals and those with pituitary tumors. This procedure can be supplemented by metrizamide CT cisternography and is simpler to perform and often better tolerated by patients than is pneumoencephalography.

Acromegaly↗

Serum levels of immunoreactive somatomedin A in the rat: some developmental aspects.

Immunoreactive somatomedin A (SMA) was determined in rat serum collected at 20 days of gestation and at 5, 15, 25, and 50 days of postnatal age. Adult levels were shown to be GH dependent. A rapid rise in immunoreactive SMA was observed after 15 days of postnatal age, and this was attributed to the triggering of the SMA-GH regulatory system by nutritional factors at weaning. Circulating levels of immunoreactive SMA were reduced during early development and in pregnancy, raising the possibility that early growth is regulated by an embryonic form of SM which is not detected by the SMA RIA.

Aging↗

Somatomedin A levels in serum from healthy children and from children with growth hormone deficiency or delayed puberty.

Serum somatomedin A (SMA) has been determined in healthy children (n = 188) in relation to age using both a radioimmunoassay and a radioreceptor assay. The SMA levels, only 50% of adult values at birth, rise gradually with age and reach adult levels at 10 years of age. There is a significant correlation (r = 0.46 P less than 0.001) between SMA determined by the two methods throughout childhood except during puberty. Immunoreactive SMA shows a marked pubertal rise in values with a peak 2 years earlier for girls than boys, which is not observed by the radioreceptor assay technique. In boys with delayed puberty the increase in immunoreactive SMA is seen first when the testes reach a size of 5 ml. Children with growth hormone deficiency (n = 30) had significantly lower levels of SMA than health age-matched controls. Immunoreactive SMA gives a better separation of these groups than the values obtained by radioreceptor assay.

Adolescent↗

Glucose tolerance, growth hormone and somatomedin levels in osteosarcoma patients.

Intravenous glucose tolerance, insulin response to glucose, the sensitivity of the periphery to insulin as well as growth hormone and somatomedin levels were determined in osteosarcoma patients and control subjects matched by age, sex, weight an length. The insulin response to glucose and the peripheral sensitivity to insulin were evaluated by using the individual blood glucose and plasma insulin curves for parameter identification in a mathematical model. The mean glucose tolerance was significantly decreased in the patients, most likely due to decreased peripheral insulin sensitivity. Plasma growth hormone levels were normal in all patients which was also the case with somatomedin levels determined by both radioreceptor- and radioimmunoassay.

Adolescent↗

Longitudinal growth and dental development in osteosarcoma patients.

The body height at 8.0 years and at the time of diagnosis, as well as the dental maturity, were analysed in a sample of patients with classical and primary osteosarcoma, registered in Sweden between 1972 and 1974, in order to investigate whether these patients have an accelerated body height growth. In contrast to previous reports the height development was found to be normal. The dental maturity was also normal.

Adolescent↗

Stereotactic radiosurgery in Cushing's syndrome: acute radiation effects.

Stereotactic radiosurgery was used for selective destruction of adrenocorticotropic hormone (ACTH)-producing adenomas in 18 patients with Cushing's syndrome. A radiation-induced lesion in the most anterior part of the sella turcica caused remission of the disease. The acute increase in ACTH and cortisol secretion that occurred in the majority of patients had no predictable relationship to the final outcome. Decreased cortisol excretion during the first three weeks after treatment was positively correlated to favourable long-term results. The treatment is a therapeutic alternative to open selective excision of the adenoma.

Adenoma↗

Effects of bromocriptine on pituitary tumour size.

In a prospective study designed to assess the influence of bromocriptine on pituitary tumour size 12 patients with pituitary tumours, eight of whom had suprasellar extensions, were treated for three months with 20 mg of bromocriptine daily after a gradual increase to this dose. The group comprised eight women and four men, five with prolactin-secreting adenomas, four with acromegaly, two with functionless adenomas, and one with Nelson's syndrome. All five patients with prolactin-secreting adenomas showed a reduction in pituitary tumour size as assessed by computerised tomography and metrizamide cisternography accompanied by a fall in prolactin concentrations and clinical and biochemical improvement in their hypopituitarism. One patient in this group had a visual-field defect before treatment, and this resolved. There was no radiological evidence of reduction in tumour size in the remaining seven patients, though this might refect the fairly short duration of treatment, particularly in view of the ancillary evidence of clinical, biochemical, and visual-field improvement in some of the patients. These results emphasise the potential value of bromocriptine in treating patients with large prolactinomas or recurrences of such tumours after previous chiasmal decompression and conventional external megavoltage irradiation on the pituitary.

Adult↗

Visual scanning and matching dysfunction in brain-damaged patients with drawing impairment.

Visual matching and visual exploration were examined in 7 normal subjects and 20 brain-damaged patients with drawing impairment measured by the Bender Gestalt Visual-Motor Test. Right brain-damaged patients made significantly more errors of rotation and integration than left brain-damaged patients. Selecteded Bender figures were also used as stimuli for both visual matching and visual exploration tests. The ability to match Bender figures was found to be impaired in right but not left brain-damaged patients. All patients showed eye movement and fixation patterns different from those normals. Patients essentially had more fixations and shorter fixation durations. Significant intercorrelations were found between the total Bender Gestalt score and visual matching and visual exploration scores. These findings indicate that visual matching and visual exploration measures can be used to evaluate perceptual impairment in individuals who do not have adequate motor responses or where impaired motor responses may confound interpretations about visual cognitive impairment.

Adult↗