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Biomedical subjects

M Chapman

Publications and source records attributed to M Chapman.

150 records · Page 9Linked to original sources

Low-dose dopamine in patients with early renal dysfunction: a placebo-controlled randomised trial. Australian and New Zealand Intensive Care Society (ANZICS) Clinical Trials Group.

BACKGROUND: Low-dose dopamine is commonly administered to critically ill patients in the belief that it reduces the risk of renal failure by increasing renal blood flow. However, these effects have not been established in a large randomised controlled trial, and use of dopamine remains controversial. We have done a multicentre, randomised, double-blind, placebo-controlled study of low-dose dopamine in patients with at least two criteria for the systemic inflammatory response syndrome and clinical evidence of early renal dysfunction (oliguria or increase in serum creatinine concentration). METHODS: 328 patients admitted to 23 participating intensive-care units (ICUs) were randomly assigned a continuous intravenous infusion of low-dose dopamine (2 microg kg(-1) min(-1)) or placebo administered through a central venous catheter while in the ICU. The primary endpoint was the peak serum creatinine concentration during the infusion. Analyses excluded four patients with major protocol violations. FINDINGS: The groups assigned dopamine (n=161) and placebo (n=163) were similar in terms of baseline characteristics, renal function, and duration of trial infusion. There was no difference between the dopamine and placebo groups in peak serum creatinine concentration during treatment (245 [SD 144] vs 249 [147] micromol/L; p=0.93), in the increase from baseline to highest value during treatment (62 [107] vs 66 [108] micromol/L; p=0.82), or in the numbers of patients whose serum creatinine concentration exceeded 300 micromol/L (56 vs 56; p=0.92) or who required renal replacement therapy (35 vs 40; p=0.55). Durations of ICU stay (13 [14] vs 14 [15] days; p=0.67) and of hospital stay (29 [27] vs 33 [39] days; p=0.29) were also similar. There were 69 deaths in the dopamine group and 66 in the placebo group. INTERPRETATION: Administration of low-dose dopamine by continuous intravenous infusion to critically ill patients at risk of renal failure does not confer clinically significant protection from renal dysfunction.

Analysis of Variance↗

Complementation analyses of Pseudomonas solanacearum extracellular polysaccharide mutants and identification of genes responsive to EpsR.

Many plant-pathogenic bacteria require extracellular polysaccharides (EPS) for successful infection. For example, mutations tht prevent EPS production in the bacterial wilt pathogen, Pseudomonas solanacearum, will reduce the ability to wilt plants. While several P. solanacearum EPS genes have been identified and characterized, a systematic analysis of EPS mutants has not previously been performed. We have screened over 12,000 transposon-tagged mutants and categorized 66EPS::lacZ mutants into nine complementation sets. Five of these are composed of previously characterized EPS structural and regulatory loci; four contain newly described EPS loci. One of the four novel complementation sets has been determined to be defective for both EPS and lipopolysaccharide production. We also used the EPS::lacZ mutants to examine the interaction between P. solanacearum EPS genes. Overexpression of the previously described regulator EpsR was found to down-regulate the expression of genes encoding production of the major acidic form EPS.

Bacterial Proteins↗

Growth and growth hormone therapy in hypochondroplasia.

The growth of 84 patients with hypochondroplasia (56 male, 28 female) was studied. A wide spectrum of severity was found from quite severe short limbed dwarfism to short apparently normal prepubertal children who manifested disproportion only at puberty when growth failed. The onset of puberty was at the normal time but the pubertal growth spurt appeared not to materialize and it is this lack which resulted in severely compromised adult heights of 145-165 cm in boys and 133-151 cm in girls. Twenty (12 M, 8 F) hypochondroplastic children aged between 4.3 and 12.8 years were recruited to a study of the effects of biosynthetic growth hormone. All had normal growth hormone responses (greater than 15 mU/l) to a pharmacological test of growth hormone secretion. Biosynthetic growth hormone in doses between 12-32 mu/m2/week produced a significant acceleration in height velocity standard deviation score (SDS) for chronological age (CA) from a pretreatment mean of -1.66 (SD 1.36) to +1.62 (SD 1.52) (p less than 0.001). Significant increases were also observed in the height SDS for bone age (BA), sitting height (SH) SDS and subischial leg length (SILL) SDS. A longer period will be required to assess the effect of treatment on adult height prognosis.

Adolescent↗

Relationships of lipoprotein lipids to mild fasting hyperglycemia and diabetes in pregnancy.

The available data have been examined to determine if plasma lipids or lipoproteins are altered in pregnant subjects with adult-onset (type II) diabetes, gestational diabetes, or the hyperglycemic extreme of a randomly selected group of pregnant women attending a prepaid health plan. In each of these groups, a trend is observed toward an increase in total plasma and very low density lipoprotein triglycerides and a decrease in high density lipoprotein (HDL) cholesterol. These observations indicate that measurements of plasma triglyceride and HDL cholesterol may be valuable in identifying and quantifying the metabolic abnormality in gestational diabetes and in prognosticating fetal outcome.

Adult↗

Birth centre or labour ward? A comparison of the clinical outcomes of low-risk women in a NSW hospital.

A number of birth centres were established in New South Wales as a result of the Shearman Report (NSW Health Department 1989). The objective of this study was to compare the obstetric outcomes, primarily caesarean section rates, of low-risk women presenting in spontaneous labour to the birth centre with those attending the hospital's conventional labour ward. The study showed that there was no significant difference in the caesarean section rate between the groups (3.5% in the birth centre and 4.3% in the labour ward). We suggest that the site of birthing does not affect clinical outcomes for low-risk women at this hospital. These results are relevant to contemporary clinical practice as they question the basis upon which birth centres have been popularised, that is, the medicalisation of birth in conventional labour wards increases intervention rates.

Adult↗