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Biomedical subjects

D Peacock

Publications and source records attributed to D Peacock.

14 recordsLinked to original sources
PubMed2001

Long-term comparative trial of positive expiratory pressure versus oscillating positive expiratory pressure (flutter) physiotherapy in the treatment of cystic fibrosis.

OBJECTIVE: The objective was to evaluate the long-term effects of physiotherapy with an oscillating positive pressure device ("flutter") compared with physiotherapy with the use of a positive expiratory pressure (PEP) mask in patients with cystic fibrosis (CF). STUDY DESIGN: Forty children with CF were randomly assigned to performing physiotherapy with the PEP mask or the flutter device for 1 year. Clinical status, pulmonary function, and compliance were measured at regular intervals throughout the study. RESULTS: The flutter group demonstrated a greater mean annual rate of decline in forced vital capacity compared with the PEP group (-8.62 +/- 15.5 vs 0.06 +/- 7.9; P =.05) with a similar trend in forced expiratory volume in 1 second (-10.95 +/- 19.96 vs -1.24 +/- 9.9; P =.08). There was a significant decline in Huang scores (P =.05), increased hospitalizations (18 vs 5; P =.03), and antibiotic use in the flutter group. CONCLUSION: Flutter was not as effective in maintaining pulmonary function in this group of patients with CF compared with PEP and was more costly because of the increased number of hospitalizations and antibiotic use.

Adolescent↗
PubMed1999

The horizontal equity of health care in New Zealand.

OBJECTIVE: Given that 'equal access for equal need' is a clearly articulated goal of the New Zealand public health system, this study is an attempt to determine if access to public health care services in New Zealand is, for people of equal health need, independent of income. METHOD: Information on health status, income and health service utilisation for just over 6,000 New Zealanders was obtained from the national Household Health Survey 1992-93. Using standardised expenditure concentration curves and a concentration index, the distribution of health service use by individuals in different income groups, as a proxy for access, was illustrated and quantified. RESULTS: The results suggest either appropriate or slightly excess use of services by the poor given their estimated health need. Due to analytical problems caused by data deficiencies, these results must be regarded as tentative. CONCLUSION: For the period under study, no evidence was found to indicate significant access barriers to publicly funded health care for people on different incomes. This study has served to demonstrate one approach to measuring inequality and analysing the relationship between inequality and inequity. Given the reforms to the health sector since 1993, ongoing monitoring of equity of access to health care services is essential. IMPLICATIONS: Given the income-related disparities in health that do exist, the public health community should endeavour to develop techniques to monitor the delivery of publicly funded health care to ensure that further inequity is not borne by the poor.

Adolescent↗
PubMed1997

Long-term comparative trial of conventional postural drainage and percussion versus positive expiratory pressure physiotherapy in the treatment of cystic fibrosis.

OBJECTIVE: We report the results of a long-term comparative trial of physiotherapy by the positive expiratory pressure (PEP) technique with a PEP mask (Astra Meditec) versus conventional postural drainage and percussion (PD&P). Forty patients, ages 6 to 17 years, with Shwachman scores between 52 and 93, attending the cystic fibrosis clinic were enrolled in the study and randomly assigned to one of two groups. Group A (control) continued to perform physiotherapy by using PD&P for a 1-year period, whereas patients assigned to group B performed physiotherapy with the PEP technique for the same period. Compliance with physiotherapy was closely monitored for both groups throughout the study. Clinical status and pulmonary function (forced vital capacity [FVC], FEV1, and FEF25-75) were measured at 3-month intervals. Group B (PEP) demonstrated improved pulmonary function in all parameters as measured by change in percent predicted value for age, gender, and height. The changes in pulmonary function over the study period were: FVC, +6.57; FEV1, +5.98; and FEF25-75, +3.32. This improvement was significantly different from that of group A (PD&P) whose pulmonary function declined in all parameters (FVC, -2.17; FEV1, -2.28; FEF25-75, -0.24). The differences between treatment groups were statistically significant for the changes in FVC (p = 0.02) and FEV(1) (p = 0.04). Our results indicate that for our patients with cystic fibrosis, pulmonary physiotherapy with the PEP technique was superior to conventional physiotherapy with the PD&P technique.

Adolescent↗
PubMed1997

Complications of long-term drainage of fetal pleural effusion: case report and review of the literature.

Severe fetal pleural effusion and ascites in the second trimester are associated with poor prognosis. We present a case where long-term drainage of several pleural effusion by a double reverse pig tail stent was achieved. Although the ultimate outcome was successful, complications seen in this case include accidental placement of the proximal opening of the catheter, first into the myometrium, then between amnion and chorion; development of oligohydramnios; intrathoracic migration of the catheter. Review of the literature reveals a multitude of other complications associated with this procedure, specifically difficulties at the time of placement and failure of function due to obstruction, migration of the catheter, or removal by the fetus. It is important to consider these complications in the counseling and management of the patients. Ongoing research is required to further improve the design of the catheters.

Adult↗
PubMed1984

Methadone poisoning due to accidental contamination of prescribed medication.

Two infants presented with fever and signs of brainstem dysfunction, including impaired consciousness, miosis, absence of oculocephalic responses, respiratory depression and a very peculiar tremor of the tongue and floor of the mouth. They were found to have methadone poisoning caused by accidental contamination of prescribed antibiotics in the same pharmacy, which was a dispensing centre for a methadone maintenance program. They recovered with supportive treatment only.

Anti-Bacterial Agents↗
PubMed1978

Evolutionary change in invertebrate cytochrome C.

Recently published amino acid sequences are compared to those of other cytochromes c. Molecular phylogenies constructed by using an ancestral sequence method are compared to the classical biological view of invertebrate evolution. Problems associated with the analysis of sequences of different chain lengths and of high variability are discussed, and the logistics of increasing the representation of key invertebrate phyla is assessed.

Amino Acid Sequence↗
PubMed1973

D-3-hydroxybutyrate dehydrogenase from Rhodopseudomonas spheroides. Kinetic mechanism from steady-state kinetics of the reaction catalysed by the enzyme in solution and covalently attached to diethylaminoethylcellulose.

1. The reversible NAD(+)-linked oxidation of d-3-hydroxybutyrate to acetoacetate in 0.1m-sodium pyrophosphate buffer, pH8.5, at 25.0 degrees C, catalysed by d-3-hydroxybutyrate dehydrogenase (d-3-hydroxybutyrate-NAD(+) oxidoreductase, EC 1.1.1.30), was studied by initial-velocity, dead-end inhibition and product-inhibition analysis. 2. The reactions were carried out on (a) the soluble enzyme from Rhodopseudomonas spheroides and (b) an insoluble derivative of this enzyme prepared by its covalent attachment to DEAE-cellulose by using 2-amino-4,6-dichloro-s-triazine as coupling agent. 3. The insolubilized enzyme preparation contained 5mg of protein/g wet wt. of total material, and when freshly prepared its specific activity was 1.2mumol/min per mg of protein, which is 67% of that of the soluble dialysed enzyme. 4. The reactions catalysed by both the enzyme in solution and the insolubilized enzyme were shown to follow sequential pathways in which the nicotinamide nucleotides bind obligatorily first to the enzyme. Evidence is presented for kinetically significant ternary complexes and that the rate-limiting step(s) of both catalyses probably involves isomerization of the enzyme-nicotinamide nucleotide complexes and/or dissociation of the nicotinamide nucleotides from the enzyme. Both catalyses therefore are probably best described as ordered Bi Bi mechanisms, possibly with multiple enzyme-nicotinamide nucleotide complexes. 5. The kinetic parameters and the calculable rate constants for the catalysis by the soluble enzyme are similar to the corresponding parameters and rate constants for the catalysis by the insolubilized enzyme.

Acetoacetates↗
PubMed1973

D-3-hydroxybutyrate dehydrogenase from Rhodopseudomonas spheroides. Kinetics of radioisotope redistribution at chemical equilibrium catalysed by the enzyme in solutions.

1. The reversible NAD(+)-linked oxidation of d-3-hydroxybutyrate to acetoacetate in 0.1m-sodium pyrophosphate buffer, pH8.5, at 25.0 degrees C, catalysed by d-3-hydroxybutyrate dehydrogenase (d-3-hydroxybutyrate-NAD(+) oxidoreductase, EC 1.1.1.30), was studied kinetically at chemical equilibrium by monitoring radioisotope redistribution with sodium dl-hydroxy[3-(14)C]butyrate and [4-(3)H]NAD(+)(labelled in the nicotinamide ring). 2. When all substrates are maintained at concentrations approaching saturation (approx. 3-50 times the K(m) values) the first-order rate constant for the enzyme-catalysed interconversion of NAD(+) and NADH is much smaller than that for the enzyme-catalysed interconversion of d-3-hydroxybutyrate and acetoacetate. 3. The rate of interconversion of NAD(+) and NADH increases initially with increasing concentrations of d-3-hydroxybutyrate and acetoacetate (ratio of concentrations maintained constant), passes through a maximum and approaches closely to zero at saturating concentrations of the latter substrates. 4. The rates of interconversion of NAD(+) and NADH and of d-3-hydroxybutyrate and acetoacetate increase with increasing concentration of NAD(+) (up to 66 times its K(m) value) and NADH (up to 180 times its K(m) value) (ratio of the concentrations of the nicotinamide nucleotides maintained constant). 5. These findings support the description of this catalysis as an ordered Bi Bi mechanism with no detectable alternative pathway, in which the interconversion of the central ternary complexes is not rate-limiting, and provide no evidence for the formation of dead-end complexes. 6. The solubility of 2,4-dinitrophenylhydrazine in HCl exhibits an acidity optimum, the maximum solubility at 25.0 degrees C (3.8mg/ml, 19mm) occurring at 2.29m-HCl; in solutions of this acidity acetone 2,4-dinitrophenylhydrazone is relatively insoluble (0.098mg/ml, 0.413mm).

Acetoacetates↗
PubMed1970

Kinetic studies of formate dehydrogenase.

1. The kinetic mechanism of formate dehydrogenase is a sequential pathway. 2. The binding of the substrates proceeds in an obligatory order, NAD(+) binding first, followed by formate. 3. It seems most likely that the interconversion of the central ternary complex is extremely rapid, and that the rate-limiting step is the formation or possible isomerization of the enzyme-coenzyme complexes. 4. The secondary plots of the inhibitions with HCO(3) (-) and NO(3) (-) are non-linear, which suggests that more than one molecule of each species is able to bind to the same enzyme form. 5. The rate of the reverse reaction with carbon dioxide at pH6.0 is 20 times that with bicarbonate at pH8.0, although no product inhibition could be detected with carbon dioxide. The low rate of the reverse reaction precluded any steady-state analysis as the enzyme concentrations needed to obtain a measurable rate are of the same order as the K(m) values for NAD(+) and NADH.

Adenine Nucleotides↗