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D Powell

Publications and source records attributed to D Powell.

At least 145 records · Page 8Linked to original sources
PubMed1979

Prolactin.

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Amenorrhea↗
PubMed1979

Brain and gut.

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Adrenocorticotropic Hormone↗
PubMed1979

Substance P plasma levels in pregnancy and in various clinical disorders.

Using radioimmunoassay, immunoreactive SP (iSP) has been measured in the plasma of 162 hospital patients with various disorders and in the plasma of 67 pregnant women. In pregnancy, iSP was undetectable in 40% women as compared to 12% in other hospital patients. The mean iSP plasma level in pregnancy was 37.8 +/- 4.6 (SEM) as compared to 77.1 +/- 4.9 (SEM) pg/ml in other hospital patients. The results support earlier observations based on bioassay, suggesting that the blood of pregnant women contains higher concentrations of a SP-inactivating factor. Of the hospital patients, elevated levels of iSP were found in patients with chronic leukaemia, in one patient with a basaloid carcinoma of the anus, and in one patient with toxic liver damage and pancreatic insufficiency. No correlation was found between thyroid function and iSP plasma levels. ISP plasma levels in various gastrointestinal disorders were similar to those found in normal subjects.

Cystic Fibrosis↗
PubMed1979

Effect of etomidate on intracranial pressure and cerebral perfusion pressure.

Ten patients with intracranial lesions, anaesthetized with thiopentone and nitrous oxide (70%) in oxygen (30%) received etomidate 0.2 mg kg-1 i.v. Ventilation was controlled in each patient. Intracranial pressure (i.c.p.) and mean arterial pressure (m.a.p.) were recorded. I.c.p. decreased significantly in all patients (0.01 greater than P greater than 0.001). Although PaCO2 decreased during the period of measurement, the extent and time-course of this change suggested that it was not mainly responsible for changes in i.c.p. M.a.p. decreased in most patients, but the decrease was statistically significant only at 3 and 4 min after the administration of etomidate (0.05 greater than P greater than 0.02). The changes in cerebral perfusion pressure (c.p.p.) and heart rate were not clinically or statistically significant. We conclude that etomidate can be used for the induction of anaesthesia in patients with intracranial space-occupying lesions without increasing i.c.p. or seriously reducing c.p.p.

Adult↗
PubMed1979

Acquired hyposegmentation of granulocytes (pseudo-Pelger-Huët anomaly) in a dog.

Hyposegmentation of granulocyte nuclei was diagnosed in an adult dog after unsuccessful attempt at finding an occult chronic infection. Intermittent signs of prostatitis were temporarily observed, but the immature nature of circulating granulocytes persisted nine months. Electron microscopic examination and neutrophil function studies revealed no abnormalities. Since previous blood smear evaluation had been normal, it is proposed that the granulocyte anomaly was acquired and may have resulted from an idiosyncratic reaction to one of several chemotherapeutic agents administered.

Animals↗
PubMed1979

A cholecystokinin-like peptide in crude substance P from human and bovine brain.

The subfractions of crude substance P (SP), Fa, Fb, and Fc, were assayed for SP-like activity (SP-LA) and cholecystokinin octapeptide-like activity (CCK-8-LA) using radioimmunoassays (RIAs) and bioassays. Crude SP preparations from total human and bovine brains, cortex, and subcortex (amygdala, substantia nigra) contain CCK-8-LA as well as SP-LA. Most of SP-LA was contained in Fb, whereas most of CCK-8-LA was in Fc. Fa gave ambiguous results. Pharmacological results previously obtained with Fc may reflect the activity of CCK-like peptide(s).

Animals↗
PubMed1978

Crude substance P from brain contains a cholecystokinin-like peptide.

The subfractions Fa, Fb, and Fc of crude substance P (SP) preparations made from human and bovine brains were analysed for SP and the COOH-terminal octapeptide of cholecystokinin (CCK-8). The methods were specific radioimmunoassays (RIAs) for SP and CCK-8, and bioassays on isolated organs of the guinea pig: the ileum, the gallbladder and the field-stimulated vas deferens. 1. In bioassays of synthetic peptides the vas deferens reacted specifically to SP and the gallbladder to CCK-8. 2. RIAs and bioassays revealed unequivocally that most of SP-like activity was present in Fb, while Fc contained mainly CCK-8-like activity. Varying results were obtained with Fa. 3. The pharmacologically active principle of Fc is CCK-8 or a closely related peptide. Earlier results concerning the pharmacological and neurochemical properties of Fc must be ascribed to this peptide.

Animals↗
PubMed1978

Effects of tracheal intubation on intracranial pressure following induction of anaesthesia with thiopentone or althesin in patients undergoing neurosurgery.

Intracranial pressure (i.c.p.) and mean arterial pressure (m.a.p.) were studied in 20 patients during the induction of anaesthesia for craniotomy. Tubocurarine was administered as the muscle relaxant and either thiopentone or Althesin for the induction of anaesthesia. No significant differences were found in the i.c.p. changes with induction, intubation or pharyngeal packing, between the thiopentone and the Althesin groups. Except for two patients (one in each group) the increases in i.c.p. associated with intubation were small. In these two patients moderate increases from normal values to 28 and 37 mm Hg were recorded, but in one of these patients coughing and straining followed intubation. Marked decreases in m.a.p. were noted in both groups, but the recovery of m.a.p. was significantly more rapid in the Althesin group. Only two patients had i.c.p. values greater than 20 mm Hg before operation and in neither did i.c.p. increase above control values during induction and intubation. Packing the pharynx produced minimal changes in i.c.p. in all patients.

Adult↗
PubMed1978

Effects of fentanyl on intracranial pressure and cerebral perfusion pressure during hypocapnia.

Ten patients presenting for carniotomy were studied. Each was anaesthetized with thiopentone or Althesin followed by tubocurarine and the lungs were hyperventilated with nitrous oxide in oxygen. Fentanyl 0.2 mg was administered i.v. and the intracranial pressure (i.c.p.) and mean arterial pressure were recorded continuously for 10 min. At the time of administration of fentanyl nine of the 10 patients were hypocapnic (PaCO2 less than 4 kPa). The changes in i.c.p. were small. Cerebral perfusion pressures less than 50 mm Hg were observed in two patients who had moderate hypotension before the drug was given. We conclude that fentanyl is a valuable agent in the hyperventilation technique in patients with intracranial space-occupying lesions, provided that hypotension is absent.

Adult↗
PubMed1978

Ectopic insulin and Occam's razor: reappraisal of the riddle of tumour hypoglycaemia.

The concept of ectopic insulin production is challenged on the basis of a review of 120 cases from the literature on extrapancreatic tumours associated with hypoglycaemia in which insulin or insulin-like activity were measured. No case met two or more of five criteria of ectopic hormone production. The evidence indicates that hypoglycaemia of extrapancreatic tumours cannot be attributed to insulin. In those rare cases in which plasma insulin was reported as high, pancreatic beta-cells could not be excluded as the source of insulin. Interestingly, many of these dubious cases had carcinoid histology. The review also points out a close association between some spindle-cell tumours and carcinoid tumours which may be relevant to discussion on the disputed origin of some "mesothelial" tumours. Nonsuppressible insulin-like activity (NSILA) consists of a number of factors mimicking insulin activity which compete with insulin or proinsulin for membrane receptors and may crossreact in bioassays, immunoassays, and receptor assays. The question of whether one or several of these substances may be responsible for extrapancreatic hypoglycaemia remains to be elucidated.

Carcinoid Tumor↗