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Biomedical subjects

C Turner

Publications and source records attributed to C Turner.

At least 163 records · Page 9Linked to original sources
PubMed1988

Bone turnover and 1,25-dihydroxycholecalciferol during treatment with phosphate binders.

The effect of dietary phosphate restriction with high-dose aluminum hydroxide or calcium carbonate on bone disease assessed by histomorphometry and on the plasma levels of 1,25-dihydroxycholecalciferol was investigated in 12 children with chronic renal failure (GFR 8 to 45 ml/min/1.73 m2, age 5 to 15 years) over a one year period. Prior to treatment patients had biochemical and histological hyperparathyroidism with greatly increased bone formation rates. During treatment, plasma phosphate levels decreased from the upper to the lower limit of normal for age (pre, 1.69 +/- 0.06 mmol/liter; 6 months, 1.28 +/- 0.06 mmol/liter; 1 year, 1.34 +/- 0.06 mmol/liter; P less than 0.01). Circulating 1,25-dihydroxycholecalciferol rose to supranormal levels within three months and remained high throughout the period of study (pre, 96 +/- 32 pmol/liter; 6 months, 144 +/- 46 pmol/liter; 1 year, 169 +/- 53 pmol/liter; P less than 0.001). Significant falls in bone formation rate at tissue and cellular levels (P less than 0.005) and in total resorption surface (P less than 0.005) were observed. A mild mineralization defect present before treatment worsened, with a decrease in mineral appositional rate (P less than 0.01) and increase in mineralization lag time (P less than 0.01). Staining for aluminum in post-treatment biopsies was positive in 9 of 11 cases. Phosphate restriction produced suppression of biochemical and histological hyperparathyroidism and sustained elevation of circulating 1,25-dihydroxycholecalciferol. The adverse changes in bone mineralization may be related to aluminum hydroxide therapy; calcium carbonate is therefore recommended.

Adolescent↗
PubMed1988

Metronidazole and gentamicin prophylaxis in synergistic aerobe-anaerobe infections in mice.

The efficacy of prophylaxis by intraperitoneal injection of gentamicin, metronidazole or both drugs combined was investigated in a mouse model of mixed infection with Escherichia coli and Bacteroides fragilis. A three dose prophylactic regimen given 12 hourly was studied starting simultaneously with bacterial challenge. Serum antibiotic concentrations lay within the human therapeutic ranges. Metronidazole alone eliminated B. fragilis from the developing infections, but at higher challenge doses the mice developed abscesses which contained E. coli, and mortality was no different from controls. Gentamicin alone eliminated both bacteria and deaths in all infections, but sterile abscesses occurred in two of five animals at the highest challenge dose. Mixed metronidazole + gentamicin abolished all effects of the challenge bacteria, aborting all infections for all challenge doses with no formation of sterile abscesses. It is proposed that, in abdominal surgery, although metronidazole or gentamicin may be effective given alone for low levels of contamination, for higher levels (e.g. colonic surgery) both drugs may be required.

Animals↗
PubMed1988

Prolonged increased responsiveness of canine peripheral airways after exposure to O3.

Because it is relatively insoluble, the oxidant gas O3 may penetrate to small peripheral airways when it is inhaled. Increased responsiveness in large airways after O3 breathing has been associated with the presence of inflammatory cells. To determine whether O3 produces prolonged hyperresponsiveness of small airways associated with the presence of inflammatory cells, we exposed the peripheral lungs of anesthetized dogs to 1.0 ppm O3 for 2 h using a wedged bronchoscope technique. A contralateral sublobar segment was simultaneously exposed to air as a control. In the O3-exposed segments, collateral resistance (Rcs) was increased within 15 min and remained elevated approximately 150% throughout the 2-h exposure period. Fifteen hours later, the base-line Rcs of the O3-exposed sublobar segments was significantly elevated, and these segments demonstrated increased responsiveness to aerosolized acetylcholine (100 and 500 micrograms/ml). There were no differences in neutrophils, mononuclear cells, or mast cells (numbers or degree of mast cell degranulation) between O3 and air-exposed airways at 15 h. The small airways of the lung periphery thus are capable of remaining hyperresponsive hours after cessation of localized exposure to O3, but this does not appear to be dependent on the presence of inflammatory cells in the small airway wall.

Airway Resistance↗
PubMed1988

In vivo exposure to ozone causes increased in vitro responses of small airways.

We examined the effects of in vivo exposure to 3 ppm ozone on in vitro reactivity of large and small airways from dogs. No effects in large airways were detected. However, small airways exposed to O3 had larger responses to receptor-mediated stimuli and similar responses to KCl plus phorbol ester. These results suggest that small airways are more vulnerable to O3 inhalation than are large airways and that receptor-mediated pathways reflect that sensitivity. Another possible explanation is that O3 exposure prevents the epithelium from playing its normal dampening role in responses to contractile agonists.

Animals↗
PubMed1987

Long-term suppression of hyperparathyroidism by phosphate binders in uremic children.

Forty-five children with stable chronic renal failure, not on dialysis, were treated conservatively with a regimen of mild dietary phosphate restriction and high-dose phosphate binders for up to 5 years. Both aluminum hydroxide and calcium carbonate were used initially, but almost all patients were taking calcium carbonate towards the end of the period. Serum immunoreactive parathyroid hormone concentrations were significantly decreased and were within the normal range after 1 year and remained normal during treatment. There was no significant change in renal function over the same treatment period. We conclude that calcium carbonate should be used as the phosphate binder of choice in the long-term suppression of hyperphosphatemia and hyperparathyroidism in uremic children.

Adolescent↗
PubMed1987

Hyperglycemia with and without glycosuria: effect on inulin and para-amino hippurate clearance.

The response of the clearance of inulin (Cin) and para-amino hippurate (CPAH) to acute hyperglycemia with and without glycosuria was investigated in ten, healthy non-diabetic subjects. Standard methodology (UV/P) was used, with a mean clearance calculated from three, 15-minute urine collection periods. Each subject was studied at three levels of blood glucose (mmol/liter) concentration, mean (SE): Level 1, fasting, 4.5 (0.1); Level 2, hyperglycemia below renal threshold for glucose, 7.2 (0.1); Level 3, hyperglycemia with glycosuria, 12.6 (0.5). There was a significant rise in mean Cin (ml/min/1.73 m2) when changing from Level 1 (112[3]) to Level 2 (121[5]), with no further increase on changing to Level 3 (122[4]). With glycosuria Cin fell in some subjects. Mean CPAH (ml/min/1.73 m2) increased through Level 1 (560[27]) to Level 3 (603[34]), with consequently no change in mean filtration fraction at the three levels of glycemia. Our observations show a rise in glomerular filtration rate with mild hyperglycemia below renal threshold, with no further increase during hyperglycemia sufficient to produce glycosuria.

Adult↗
PubMed1987

Investigation of adrenomedullary function in atopic dermatitis.

Adrenomedullary function in patients with atopic dermatitis was assessed by measurement of plasma levels of catecholamines (adrenalin and noradrenalin) and cyclic AMP in response to the stimuli of standing after lying supine, and a 5-min infusion of histamine in the standing position (i.e. histamine plus standing). Plasma clearance of adrenalin was examined by measurement of plasma catecholamine and cyclic AMP levels following a 15-min intravenous infusion of adrenalin in the supine position. Resting plasma levels of adrenalin, cyclic AMP and noradrenalin were not statistically different in atopic patients and normal controls. Standing or intravenous infusion of histamine in the standing position caused a rise in plasma catecholamine levels. Plasma adrenalin, cyclic AMP and noradrenalin levels in response to these stimuli and the rate of clearance of exogenous adrenalin from the plasma were not significantly different in patients with atopic dermatitis and in normal subjects.

Adolescent↗
PubMed1987

Marital therapy outcome measured by therapist, client, and behavior change.

The present research examined marital therapy outcome, in a sample of 88 couples and 22 therapists, through the use of multidimensional criteria from multiple perspectives. Three paper-and-pencil patient self-report instruments were used to measure different aspects of the couple relationship. In addition, therapist post-therapy ratings and objective observer ratings of the couple behavior during therapy were obtained. Past debates about what the "right" criteria might be for measuring therapeutic change prompted our strategy. Special attention was focused on those criteria that could be classified as "inside" or "outside" of the couple relationship. Data analysis revealed a significant relationship between the couples' and therapists' ratings of improvement in therapy. Additionally, husband and wife negative acts (behaviors) in therapy were also significantly correlated with therapists' ratings of improvement. Both statistically significant and clinically significant criteria were employed to evaluate the therapy outcome. Improvement due to therapy as measured by the three self-report instruments varied from 38% to 58%. These differences appeared to stem from the different kinds of information yielded by the specific tests.

Adult↗
PubMed1987

A molecular approach to immunoscintigraphy: a study of the T-antigen conformation on the surface of tumors.

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both alpha and beta configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the beta configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

Animals↗
PubMed1986

Unfair to diabetics.

Explore the source record for details and available documents.

Diabetes Mellitus, Type 1↗