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Biomedical subjects

H Dick

Publications and source records attributed to H Dick.

At least 37 records · Page 2Linked to original sources
PubMed1989

Disturbed endocrine function in the psychoses. II: Discriminant function analysis of multihormone data.

Discriminant function analyses were performed on plasma concentrations of prolactin, growth hormone, cortisol, TSH, and the neurophysins measured over 17 hours in 70 newly admitted drug-free psychiatric patients and 35 control subjects. The hormone data distinguished between patients with different classes of drug-free psychosis (26 schizophrenic, 12 with manic disorder, 10 with major depressive disorder, psychotic subtype, 9 with schizoaffective mania (SAM]. Higher plasma cortisol and lower TSH concentrations separated eight of nine SAM patients from all others.

Bipolar Disorder↗
PubMed1987

Elevated plasma luteinizing hormone concentrations, cryptorchidism and mania.

A young man with acute mania and unilateral cryptorchidism had plasma luteinizing hormone (LH) concentrations that were much higher than the maximum LH concentrations we have found in normal subjects and patients with schizophrenia. Plasma concentrations of testosterone and sex hormone binding globulin were not abnormal, showing that the elevated plasma LH concentrations were probably due to increased secretion of LH-releasing hormone (LHRH). This case supports our previous results which suggest that an abnormally high secretion of LHRH, due presumably to an abnormality in central neurotransmission, may be a feature of acute mania in young men.

Acute Disease↗
PubMed1987

Characteristic plasma hormone changes in Alzheimer's disease.

A systematic endocrine investigation in dementia, depression and control subjects showed that plasma growth hormone (GH) was higher in the morning and plasma TSH concentrations were higher throughout the day in Alzheimer-type dementia (ATD) than in age-matched depressed patients (MDD), and plasma TSH concentrations were also higher throughout the day in female ATD compared with age-matched female control subjects. The increased plasma TSH concentrations could not be due to reduced negative feedback because plasma T3, T4 and rT3 were in the normal range. Plasma concentrations of oestrogen-stimulated neurophysin (ESN) were lower throughout the day in ATD compared with MDD and controls and lower in the morning compared with other dementias. The high plasma GH and TSH concentrations in ATD may reflect the reduced hypothalamic content of somatostatin in ATD, and the reduced concentrations of ESN may reflect reduced cholinergic activity in ATD brain. These selective hormonal changes provide a useful diagnostic test for Alzheimer's disease.

Adult↗
PubMed1987

Increased plasma LH in manic-depressive illness: evidence of a state-independent abnormality.

Basal plasma luteinising hormone concentrations and the LH responses to LH-releasing hormone injection were higher in 11 young men after recovery from mania than in 15 control subjects. Since plasma concentrations of testosterone and sex hormone binding globulin were similar in the recovered manic compared with the control subjects, the increased LH response to LHRH is likely to have been due to the priming effect of LHRH consequent on an increased release of LHRH into hypophysial portal vessel blood. Abnormal control of LHRH, and thereby LH release, is a state-independent feature in male patients with mania and may be a useful trait marker for this disorder.

Adult↗
PubMed1986

Glucocorticoid receptors and depression.

The number of glucocorticoid receptor sites in lymphocytes was estimated and plasma cortisol concentrations measured in 17 depressed patients, 12 patients with chronic schizophrenia, and 31 healthy control subjects. The number of receptor sites was significantly lower in the depressed patients than in either the controls or the patients with chronic schizophrenia, but there were no differences between the groups in the dissociation constants of the glucocorticoid receptors or the plasma cortisol concentrations. When two control subjects were studied intensively over 28 hours a slight diurnal variation in the number of glucocorticoid receptors was detected. The lower numbers of glucocorticoid receptors in the lymphocytes of depressed patients may explain why such patients, who often have hypercortisolaemia, do not show the clinical features of excess production of cortisol.

Adult↗
PubMed1986

Raised plasma cortisol concentrations a feature of drug-free psychotics and not specific for depression.

To determine whether high plasma cortisol concentrations are a distinctive feature of depression or whether plasma cortisol is also elevated in other forms of psychosis, cortisol concentrations were measured in 59 patients with acute functional psychoses, six non-psychotic depressed patients and 37 control subjects, all free of antidepressant and neuroleptic drugs for at least three months. Patients with schizo-affective disorder, manic type, had the highest concentrations throughout the day and those with major depressive disorder, psychotic sub-type had higher concentrations than controls in the afternoon and evening. Manic and schizophrenic patients had cortisol concentrations above controls in the afternoon only. Elevated concentrations were not related to the presence of depressed mood or to duration of stay in hospital, and a return to normal occurred irrespective of the type of treatment used. Thus raised plasma cortisol concentrations are a feature of psychotic illness, but in drug-free patients are not specific for severe depression.

Adolescent↗
PubMed1985

Selective increase in plasma luteinising hormone concentrations in drug free young men with mania.

The hypothalamic-pituitary-gonadal system was investigated in drug free young men with either mania or acute schizophrenia and in age matched controls by measuring, at frequent intervals during a 17 hour "neuroendocrine day," plasma concentrations of luteinising hormone (LH), follicle stimulating hormone, prolactin, testosterone, sex hormone binding globulin (SHBG), and cortisol. Plasma LH in mania was significantly increased compared with the control value at all time periods and increased in the morning and evening samples compared with values in the schizophrenic patients. Plasma prolactin and cortisol concentrations were significantly greater in mania and schizophrenia compared with control values at several times during the day, but there were no significant between group differences in plasma testosterone or SHBG. These results show that in young men with mania there is a major disturbance in the central mechanisms that control the release of LH, the control of prolactin and cortisol secretion is abnormal in mania and acute schizophrenia, and plasma LH concentrations may provide a useful hormonal diagnostic test for mania.

Adolescent↗
PubMed1985

Swarmer cell differentiation of Proteus mirabilis in fluid media.

After 3-4 h in a rich fluid medium such as brain--heart infusion broth, motile nonseptate filaments developed from normal short rods and formed about 80% of the cell mass of Proteus mirabilis PM23. This developmental pattern was not observed in any of the other nine representatives of the species. These filaments were considered to be equivalent to swarmer cells formed on agar media because these cells ceased tumbling (i.e., chemotaxis was repressed), they developed large numbers of flagella (i.e., flagella synthesis and insertion was derepressed), and the distribution of nuclei in the filaments indicated that there was normal segregation. The population of cells grown in a minimal medium supplemented with amino acids and nicotinic acid consisted only of short cells with tumbling motility, despite the production of long cells and swarming on the same medium solidified with ordinary agar (refined agar was not effective). These short cells differentiated in 1-1.5 h in brain--heart infusion broth at 37 degrees C after an initial division. The requirements for initiation of differentiation were good basal nutrition, suitable cations (probably Ca2+ and Na+, or K+), and unknown heat-stable organic factors (molecular weight less than 10 000) present in crude agar and yeast extract. Other components of media promoted swarmer differentiation if it was initiated and these included organic acids (lactate), amino acids (proline or serine), phosphate, and an appropriate ionic environment. Comparison of the observed sequence of length classes in brain--heart infusion broth culture with computer generated growth models suggested that, at the outset of growth, 50% of the products of each short cell division ceased septation but grew in length for about five doubling periods and then divided cells from each end at a faster rate (3-5 times per hour) for return to the short cell pool.

Antibodies, Bacterial↗
PubMed1983

7. Corticosteroid secretion--clinical aspects. Plasma cortisol concentrations in the functional psychoses and Alzheimer type dementia: a neuroendocrine day approach in drug-free patients.

We have investigated the plasma concentration of cortisol in psychotic patients classified according to Feighner's criteria as either depressed, manic, schizophrenic or unclassified, and in 8 patients with Alzheimer's Type Dementia. The patients had been free of either neuroleptic or antidepressant drugs for at least 3 months before the study. Blood sampling was carried out by way of a "neuroendrocrine day" approach in which venous samples were taken at 07:00, 07:30 and 08:00 h; 15:00, 15:30 and 16:00 h; and 23:00, 23:30 and 24:00 h. This approach permits determination of circadian pattern of hormone release and allows for pulsatile hormone release. These preliminary results showed that, contrary to expectation, neither the mean concentrations nor the circadian pattern of plasma cortisol concentrations in patients with depression differed significantly from those in any other group.

Alzheimer Disease↗
PubMed1982

Immediate increases in plasma prolactin and neurophysin but not other hormones after electroconvulsive therapy.

Plasma prolactin, growth hormone, cortisol, luteinising-hormone-releasing hormone (LHRH), thyrotropin-releasing hormone (TRH), and nicotine and oestrogen stimulated neurophysin (NSN and ESN) were measured before and for 6 min after electroconvulsive therapy (ECT) in eight women with severe electroconvulsive therapy (ECT) in eight women with severe depression. Plasma concentrations of NSN and ESN had increased significantly (as much as 10-fold for NSN) within 1 min of the seizure, and concentrations of prolactin had increased within 2-4 min after the seizure. Whereas plasma prolactin and ESN either continued to increase or remained raised throughout the 6 min after seizure, the concentrations of NSN fell to reach a value at 6 min that was approximately 50% of the maximum. There were no increases in any of the other hormones or peptides within the 6 min period under study. Thus ECT has selective effects on hormone release which cannot be attributed simply to a generalised release of pituitary or hypothalamic hormones in response to brain stimulation and/or stress.

Adult↗
PubMed1982

Sex difference in response to alphaxalone anaesthesia may be oestrogen dependent.

The steroid anaesthetic Althesin (Glaxo), which is a mixture of two C21 steroids, alphaxalone (3 alpha-hydroxy-5 alpha-pregnane-11, 20-dione--the active compound) and alphadolone acetate (21-acetoxy-3 alpha-hydroxy-5 alpha-pregnane-11, 20-dione), has been especially useful for the study of forebrain-autonomic and neuroendocrine functions. As determined by the loss of the righting reflex, Child et al. found no sex difference in the anaesthetic dose of Althesin administered intravenously (i.v.). However, in our neuroendocrine studies in which the anaesthetic was administered intraperitoneally (i.p.) and at dosage sufficient to produce surgical anaesthesia and analgesia, we observed a sex difference in the efficacy of Althesin. This may explain the difficulties that have been encountered in obtaining adequate anaesthesia (blockade of the somatomotor response to pain) with Althesin. Here we report, using cortical electroencephalography, that Althesin is a more potent anaesthetic than either sodium pentobarbitone or urethane, and that anaesthesia in the male rat requires about four times more Althesin (administered i.p.) than in the female. This sex difference is age dependent, can be abolished by administering oestrogen to the male, does not depend on sexual differentiation of the brain, and cannot be attributed to a sex difference in the metabolic clearance rate of alphaxolone. These results, taken together with those of Richards and Hesketh, suggest that the effect of alphaxalone may be mediated by interactions with synaptic membranes that are more specific than simply a generalized change in membrane structure, and that these interactions are affected by sex steroids.

Age Factors↗
PubMed1982

Effect of ECT on the neuroendocrine response to apomorphine in severely depressed patients.

Animal studies have suggested that the mechanism of the antidepressant action of ECT may be to increase monoaminergic post-synaptic receptor sensitivity. We have tested this hypothesis in 12 drug-free patients suffering from severe depression, 11 of whom had depressive delusions. The responses of growth hormone, prolactin and cortisol to 0.75 mg subcutaneous apomorphine were examined before and after a successful course of ECT. There were no significant differences between hormonal measurements on the two occasions, with the exception that basal plasma cortisol concentrations were significantly lower following ECT and recovery from depressive illness. These results do not support the hypothesis that ECT increases dopaminergic post-synaptic receptor sensitivity.

Adult↗
PubMed1981

HLA antigens in adults negative for antibody to Epstein-Barr virus (EBV).

Evidence for a genetic component in susceptibility to Epstein-Barr virus (EBV) infection was sought by comparing HLA A and B phenotypes of EBV antibody-negative Scottish medical students and randomly chosen antibody-positive controls. No statistically significant differences were observed, but three antigens, (A10, A29 and B15), were relatively underrepresented in the EBV seronegative group; findings which agree with data previously reported from a similar study in Los Angeles. A strong association between the HLA A1/Blank phenotype and EBV seronegativity, evident in the Los Angeles population, was not confirmed in the present study.

Adult↗
PubMed1978

Metabolism of immunoglobulin A, lymphocyte function, and histocompatibility antigens in patients on anticonvulsants.

Low serum IgA levels were found in patients taking phenytoin, together with evidence of depressed T cell function. There was no correlation between the dose or the serum level. A correlation was found, however, with HL-A status, patients with a low IgA showing increased frequency of HL-A2. It is suggested that epileptic patients with HL-A2 status are likely to develop IgA deficiency when given phenytoin.

Adolescent↗
PubMed1977

Spread of epidermoid carcinoma of the lip along the inferior alveolar nerve.

Reported is a case of epidermoid carcinoma of the lower lip that spread along the inferior alveolar nerve to the cranium. Early clinical symptoms are correlated with radiographic and histopathologic findings, and attention is again called to the fact that carcinomas of the head and neck may occasionally spread along nerve pathways.

Carcinoma, Squamous Cell↗