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Biomedical subjects

C Brown

Publications and source records attributed to C Brown.

At least 451 records · Page 25Linked to original sources
PubMed1984

Inhibition of bacterial aggregation by serum- and blood-derived proteins.

Human and animal sera contain potent inhibitors of saliva-mediated aggregation of oral streptococci. The inhibitors consist of a high-molecular-weight heat-labile factor and a lower-molecular-weight heat-activated factor. The latter appears to be serum albumin. Analyses of purified blood-derived proteins indicated that several high-molecular-weight proteins (fibrinogen, fibronectin, and ferritin) were able to inhibit aggregation at low concentrations. These data suggest that high-molecular-weight proteins may modulate the aggregation process.

Animals↗
PubMed1984

Effects of age and steroid treatment on prostaglandin production by the rat uterus in relation to implantation.

Prostaglandin (PG) production by the uterus of ovariectomized virgin rats, with and without replacement steroid therapy, was compared in animals aged 4-5 and 13-14 months. The synthesizing capacities of the uterus for PGE-2, PGF-2 alpha. 6-keto-PGF-1 alpha and thromboxane (TX) B-2 (expressed as the amounts synthesized per mg protein by the homogenized tissue during a 90-min incubation) were significantly lower in the ageing uteri than in young uteri. The PG and TX synthesizing capacities of the young uteri, but not of the ageing uteri, were stimulated by sequential treatment with oestradiol and progesterone implants. Tissue concentrations in and release from the uteri of PGE-2, but not of PGF-2 alpha, were significantly lower in ageing rats than in younger rats, and occurred irrespective of the hormonal status. Treatment with steroids did not stimulate the tissue concentrations in or release from the uterus of PGE-2 or PGF-2 alpha in young or ageing rats. Since PGs, particularly PGE-2, produced by the rat uterus have been implicated as mediators of the implantation process, reduced production of PGE-2 by the ageing uterus may explain the lower implantation rate and the consequent reduction in fertility of ageing rats.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

Multicenter clinical evaluation of ketoconazole in the treatment of cutaneous fungal infections.

An open, multicenter study was conducted to evaluate the efficacy and adverse effects of ketoconazole in patients with cutaneous fungal infections seen in typical dermatology practices. One hundred twelve American investigators entered 954 patients into this trial. Responses based on clinical and mycologic assessments were available on 672 patients. Mycologic evaluations were conducted using pre- and post-therapy wet mounts in potassium hydroxide. Eighty percent of these patients were mycologically clear and clinically rated as either excellent (cured) or marked improvement. Adverse effects were mild to moderate in severity and only rarely caused therapy to be interrupted. Gastrointestinal effects were the most frequently reported complaints.

Adolescent↗
PubMed1984

Renal handling of urate during water immersion in the nephrotic syndrome.

Renal handling of urate was examined in 11 patients with nephrotic syndrome before, during, and after 4 h of water immersion up to the neck. Urinary urate excretion, urate clearance, and fractional excretion of urate all increased significantly during water immersion, and decreased in the hour following water immersion. During water immersion fractional excretion of urate rose to a maximum of 16 ml/ml of glomerular filtrate, and fell towards control levels on removal from the bath. It is concluded that either there is a decrease in proximal tubular urate reabsorption or secretion caused by water immersion. In contrast, diurnal control studies showed no significant change in fractional excretion of urate during the same period of the day. It is postulated that the increased fractional excretion of urate on water immersion is due to hypervolemia induced by the hydrostatic pressure of the water on the lower limbs and abdomen.

Adolescent↗
PubMed1983

Insulin secretion: combined effects of phorbol ester and A23187.

The effect of the ionophore, A23187, and/or the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), on insulin secretion were compared with those of glucose. Glucose induces a biphasic pattern of insulin secretion; A23187 a comparable initial spike but no second phase; and TPA a slowly progressive increase. Combined A23187 and TPA evoke a pattern similar to that induced by glucose. Forskolin enhances both phases of glucose- induced and of TPA-A23187-induced insulin secretion. These results are interpreted in terms of a model of cell activation in which two branches of the calcium messenger system, the calmodulin branch and the C-kinase branch, control, respectively, the initial and sustained phases of insulin secretion.

Animals↗
PubMed1983

Diazepam-induced NaCl solution intake: independence from renal factors.

Rehydrating rats injected with diazepam (8 mg/kg, SC) increased their intake of 2.0% NaCl solution. Neither bilateral nephrectomy nor bilateral ureter ligation interfered with the increased NaCl solution ingestion produced by diazepam. It is concluded that the increased intake of the NaCl solution is not secondary to renal water-electrolyte losses nor dependent upon intact renal benzodiazepine receptors.

Animals↗
PubMed1983

Irritable bowel syndrome: relationship of disorders in the transit of a single solid meal to symptom patterns.

The time taken for a solid meal to pass through the stomach, small intestine, and colon was measured in 61 patients with irritable bowel syndrome, subdivided according to their presenting symptoms, and in 53 healthy volunteers. Small bowel transit times were significantly shorter in patients who complained predominantly of diarrhoea (3.3 +/- 0.3 vs 4.2 +/- 0.2 h; p = 0.01; n = 21) and significantly longer in patients who complained predominantly of constipation (5.4 +/- 0.3 vs 4.2 +/- 0.2 h; p less than 0.01; n = 23) or pain and distension (5.4 +/- 0.4 vs 4.2 +/- 0.2 h; p less than 0.01; n = 17) compared with controls. Whole gut transit times were shorter in patients who complained of diarrhoea (35 +/- 5 vs 53 +/- 4 h; p less than 0.01), and longer in patients with constipation (87 +/- 13 vs 53 +/- 4 h; p less than 0.05) compared with controls. No significant differences in gastric emptying rates were shown between any of the patient groups and normal controls. Thirty-four patients reported pain, particularly in the right iliac fossa, during the meal transit test, and in 25 of these (74%), the onset of the pain was associated with the arrival of residues of the test meal in the caecum. Our results indicate that irritable bowel syndrome should be considered a disease of the small intestine as well as the colon.

Adult↗
PubMed1983

Ectopic ACTH-producing lung cancer presenting with prostatic metastasis.

The case is described of a patient presenting with prostatic symptoms and a biopsy proven neoplasm in the prostate gland. Radical radiotherapy initially given to the pelvis produced satisfactory symptomatic improvement with tumour regression, but the patient subsequently developed endocrine complications which led to the site of the primary carcinoma being reconsidered. The case illustrates the ubiquitous nature of aggressive metastatic cancer.

ACTH Syndrome, Ectopic↗
PubMed1983

Renal calcium and magnesium handling in water immersion in nephrotic patients.

The effect of water immersion to the neck on renal calcium and magnesium handling was studied in 11 nephrotic patients. There was an increase in the urinary excretion of both calcium and magnesium on immersion, and a return towards preimmersion control values in the hour following immersion. Clearances of calcium and magnesium, and fractional excretion of calcium and of magnesium all increased significantly during water immersion, and decreased in the postimmersion hour. However, magnesium excretion was 10-50 times greater than calcium excretion. Fractional excretion of sodium was highly significantly related to fractional excretion of calcium (p less than 0.001) and magnesium (p less than 0.001). The relationship between fractional excretion of phosphate and fractional excretion of calcium was statistically significant (p less than 0.05), as was that between fractional excretion of phosphate and that of magnesium (p less than 0.01). Magnesium and calcium fractional excretions were significantly correlated (p less than 0.01). It was concluded that the increase in calcium and magnesium excretion on immersion is likely to be related to the sodium diuresis caused by central hypervolemia due to immersion.

Adolescent↗
PubMed1983

ELISA assay for IgG autoantibody to G-actin: comparison of chronic active hepatitis and acute viral hepatitis.

An ELISA was developed to test for IgG autoantibody to rabbit skeletal muscle G-actin in liver disease. To express results of the ELISA, we used a single reference serum with known high anti-actin activity, and assessed binding of test sera as a percentage of that displayed by the reference antiserum. Antibody to G-actin was measured in 40 sera from patients with chronic active hepatitis (CAH), 39 from acute viral hepatitis A (Hep A), 46 from acute viral hepatitis B (Hep B), 23 from non-A, non-B hepatitis (Hep non-A, non-B), 31 from systemic lupus erythematosus (SLE), 21 from scleroderma and 93 from normal persons. The results were compared with those obtained using indirect immunofluorescence tests with frozen sections of rodent stomach or fibroblast monolayers as substrates. Anti-G-actin activity of serum was significantly higher (P less than 0.001) in CAH (mean 63% +/- 23, range 18-110) than in controls (mean 15% +/- 12, range 0-51), systemic lupus erythematosus (mean 25% +/- 16, range 8-76), scleroderma (mean 23% +/- 13, range 3-59), Hep A (mean 24% +/- 11, range 6-25), Hep B (17% +/- 8, range 2-36), or Hep non-A, non-B (mean 23% +/- 11, range 7-53). There was no significant difference (P greater than 0.05) in the occurrence of anti-G-actin activity of serum in Hep A, Hep B or non-A, non-B compared with controls. At an ELISA reading of greater than or equal to 40% (mean + 2 s.d. of controls) the assay detected autoantibodies to G-actin in 85% of CAH, compared to 80% on fibroblast monolayers and 70% on rodent stomach. The ELISA described in the present study is a simple, sensitive and quantitative assay for autoantibody to G-actin. It should prove useful in assessing subspecificities of actin antibodies in liver diseases, and in differential diagnosis, particularly CAH from acute viral hepatitis.

Actins↗
PubMed1983

Nodular adrenal hyperplasia and Cushing's syndrome.

Clinical, biochemical, operative, and postmortem findings have established nodular adrenal hyperplasia as a clinicopathologic entity and a cause of Cushing's syndrome. The possibility exists that there is a relationship among the various forms of adrenal and pituitary diseases that lead to hyperadrenocorticism. This may include a continuous sequence from bilateral adrenal hyperplasia to micronodular and macronodular hyperplasia to a unilateral adrenocortical adenoma and even carcinoma. We report the investigation and management of six patients with Cushing's syndrome caused by bilateral nodular adrenal hyperplasia who were treated by operation at the Glasgow Royal Infirmary, Scotland from 1975 to 1979. Investigations included a variety of biochemical and radioimmunoassay tests on plasma and urine, provocative and inhibition tests, scanning (ultrasonography, computed tomography, and iodocholesterol), arteriography, and selective venous sampling. All patients underwent a bilateral adrenalectomy by the posterior approach. The adrenal glands varied in size from 4.9 to 18 gm and histology showed that they had the features of bilateral nodular adrenal hyperplasia. Five patients did well after operation; they are presently receiving replacement steroid therapy, and at a 3- to 7-year follow-up there was no evidence of Nelson's syndrome. Advances in drug therapy (medical adrenalectomy) with aminoglutethimide, metyrapone, and O,p-DDD should not at present cause a change in our surgical approach to this condition.

Adrenal Glands↗