Australian resources for ethical participatory processes in public health research.
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Australia↗
Biomedical subjects
A Madden
Publications and source records attributed to A Madden.
Psychiatric symptoms, functional impairment, and receptivity toward mental health treatment among obstetrical patients.
OBJECTIVE: To examine psychiatric symptomatology and associated functional impairment among pregnant women; and to examine the obstetrical patient's receptivity to discussion of and intervention regarding emotional distress. METHODS: Fifty-seven patients 16 weeks or less pregnant presenting for routine obstetrical appointments at a faculty practice at a major medical center participated in this study. Each completed a self-administered assessment packet regarding psychopathology, functional impairment and service utilization attitudes. Statistical analyses were performed using chi-square and Mann-Whitney tests. RESULTS: Seventeen subjects (29.8 percent) screened positive for at least one anxiety disorder. Fourteen of those subjects also screened positive for depression. Those with positive screens for either anxiety and/or depression had significantly higher levels of functional impairment. Only five (29.4 percent) of the 17 subjects with positive screens reported having discussed an emotional issue with their Ob/Gyn, although 14 (82.4 percent) said that they would be willing to do so. All subjects (100 percent) reported that they would see a mental health professional if their Ob/Gyn referred them. CONCLUSION: Routine screens for mental disorders in early pregnancy appear to be a useful adjunct in an obstetrical setting. Although most had never discussed their emotional concerns with their Ob/Gyn, a substantial proportion of our study sample reported psychiatric symptomatology and significant levels of functional impairment that had not been recognized by their Ob/Gyn. All of the patients in our study sample reported a willingness to see a mental health professional if their Ob/Gyn referred them. Further studies investigating the benefits of antenatal diagnosis and treatment of psychiatric disorders are warranted.
Adult↗
Cesarean delivery of twins and neonatal respiratory disorders.
OBJECTIVE: The objective of this study was to evaluate the risk of neonatal respiratory disorders when cesarean delivery is performed before labor in twin pregnancies. STUDY DESIGN: We reviewed the charts of all patients with twin pregnancies who underwent cesarean delivery before labor after 36 weeks' gestation. All cases in which delivery was done for a clear maternal or fetal indication were excluded. Neonatal respiratory disorders included transient tachypnea of the newborn and respiratory distress syndrome. RESULTS: Delivery was performed between 36 weeks' and 37 weeks 6 days' gestation in 79 patients (62.7%) and between 38 weeks' and 40 weeks 2 days' gestation in 47 patients (37.3%). Respiratory disorders were diagnosed in 15 neonates from 11 pregnancies. Pregnancies in which one or both neonates were diagnosed with respiratory disorders were more likely to have been delivered before 38 weeks' gestation (90.9% vs 60.0%; P =.04) and were more likely to have been conceived spontaneously (54.5% vs 21.7%; P =.03) than those pregnancies with no affected neonates. CONCLUSIONS: Neonatal respiratory disorders are more common in twin pregnancies with cesarean delivery performed before labor before 38 weeks' gestation. Without a clear indication for delivery, waiting until labor or until after 38 weeks' gestation should be considered.
Adult↗
Density estimates of rural dog populations and an assessment of marking methods during a rabies vaccination campaign in the Philippines.
We estimated the population density of dogs by distance sampling and assessed the potential utility of two marking methods for capture-mark-recapture applications following a mass canine rabies-vaccination campaign in Sorsogon Province, the Republic of the Philippines. Thirty villages selected to assess vaccine coverage and for dog surveys were visited 1 to 11 days after the vaccinating team. Measurements of the distance of dogs or groups of dogs from transect lines were obtained in 1088 instances (N = 1278 dogs; mean group size = 1.2). Various functions modelling the probability of detection were fitted to a truncated distribution of distances of dogs from transect lines. A hazard rate model provided the best fit and an overall estimate of dog-population density of 468/km2 (95% confidence interval, 359 to 611). At vaccination, most dogs were marked with either a paint stick or a black plastic collar. Overall, 34.8% of 2167 and 28.5% of 2115 dogs could be accurately identified as wearing a collar or showing a paint mark; 49.1% of the dogs had either mark. Increasing time interval between vaccination-team visit and dog survey and increasing distance from transect line were inversely associated with the probability of observing a paint mark. Probability of observing a collar was positively associated with increasing estimated density of the dog population in a given village and with animals not associated with a house. The data indicate that distance sampling is a relatively simple and adaptable method for estimating dog-population density and is not prone to problems associated with meeting some model assumptions inherent to mark-recapture estimators.
Animal Identification Systems↗
Radial diffusion coefficient mapping.
The two-dimensional mapping of the effective diffusion coefficient of water in tissues may provide a useful method of tissue characterization to complement T1 and T2 relaxation time studies for diagnostic purposes. Current diffusion techniques rely on the application of large gradient strengths and long echo times to achieve the required sensitivity. This, in turn, limits the applicability of the technique to tissues having long T2s with rapid water diffusion. In addition, the inherent directionality of these methods results in only the partial encoding of diffusion information. A modified diffusion sequence is presented, radial diffusion mapping (RAD), which provides enhanced sensitivity diffusion maps by employing gradient sensitization in three orthogonal directions. Results in both phantoms and volunteers are presented, together with an investigation of the effects of T2 on the measurement accuracy. Using RAD, a two- to five-fold improvement in sensitivity was achieved, thus significantly enhancing the dynamic range of the method and allowing more accurate in vivo diffusion measurements to be carried out.
Acetone↗
The unstable ST segment early after thrombolysis for acute infarction and its usefulness as a marker of recurrent coronary occlusion.
To investigate the incidence of early recurrent ST elevation after intravenous thrombolytic therapy for acute myocardial infarction, 12-lead electrocardiograms were continuously monitored for 571 +/- 326 minutes in 31 patients presenting within 4 hours of symptom onset. The study group comprised 9 women and 22 men (mean age +/- standard deviation 53 +/- 12 years), with ST elevation (anterior in 15, inferior in 16) on the initial electrocardiogram, who were given either tissue plasminogen activator (22 patients) or streptokinase (9 patients). Angiography was performed in 30 of 31 patients at 7 to 10 days. Early (less than 3 hours) resolution of ST elevation occurred in 19 patients (61%) at a median of 94 minutes (interquartile range 57 to 113) after thrombolysis, whereas 12 (39%) had no or late (greater than 6 hours) resolution. Eleven of the 19 with early resolution (58%) had either transient (5 patients) or sustained (6 patients) recurrences of ST elevation. Recurrent ST elevation was equal to or more than the initial peak elevation in 9 of 11 patients, and greater than 75% of initial peak in 2. A total of 25 episodes of recurrent ST elevation were observed in the 11 patients (19 transient and 6 sustained episodes), of which 8 (32%) were silent. The proportion of silent episodes was similar for transient (35%) and sustained (33%) recurrences. All patients with sustained recurrent ST elevation had at least 1 preceding transient recurrence. The median duration of transient recurrent ST elevation was 43 minutes (28 to 63).(ABSTRACT TRUNCATED AT 250 WORDS)
Coronary Angiography↗
The water resonance as an alternative pH reference: relevance to in vivo 31P NMR localized spectroscopy studies.
pH measurements require a suitable pH reference within the 31P NMR spectrum with respect to which the chemical shift of Pi, and hence pH, may be calculated. In muscle spectra PCr is prominent and provides a reference frequency. However, recent localized tumor studies have reported the absence of PCr, for example, in breast tumors. The use of the alpha-, beta-, and gamma-ATP peaks as suitable references has been suggested, but the position of the beta- and gamma-ATP peaks is dependent upon the intracellular Mg2+ concentration. The alpha-ATP is not affected by ionic concentrations; however, it contains UDPG and NAD+, the presence of which can lead to peak-shape distortion. This paper considers the use of the H2O resonance from the proton spectrum used for shimming as a suitable pH reference, provided this is also localized to the same region of interest, using a sequence giving rise to eddy current effects comparable to those of the 31P NMR sequence. Localized in vivo measurements in the muscle and brain of volunteers indicate good agreement between the proton and phosphorus chemical shifts, allowing the PCr position to be predicted to within 0.01 ppm in all cases.
Body Water↗
A quantitative analysis of the accuracy of in vivo pH measurements with 31P NMR spectroscopy: assessment of pH measurement methodology.
31P NMR spectroscopy provides a means of monitoring intracellular pH (pHi). In order to determine the significance of observed pH changes, an assessment of the measurement uncertainty is required. This paper considers the possible sources of error involved, firstly in chemical shift assignment and, secondly, in relating chemical shift to pH. A statistical analysis of these errors is presented and an expression for the accuracy of pH measurements obtained using in vivo 31P NMR spectroscopy is derived. Computer simulations and clinical measurements are considered to determine the likely error in clinical measurements. A comparison of pH measurement methodology using a centre-of-gravity calculation, Gaussian and Lorentzian fitting is also presented and discussed.
Humans↗
The effect of non-protein liquid meals on the hepatic venous pressure gradient in patients with cirrhosis.
It has been suggested that protein feeding increases portal pressure in cirrhotic patients, but that carbohydrate and fat have little effect. We examined the relationship between feeding and portal pressure, using different liquid test meals (250 or 500 ml non-protein, 250 ml protein-containing, 500 ml water), in 29 alcoholic patients with cirrhosis and portal hypertension. The mean hepatic venous pressure gradient (HVPG) increased significantly 30 min after the protein meal (10% increase; p = 0.009) and returned to basal levels at 60 min. The mean HVPG also increased significantly after the non-protein meal: after 500 ml the increase was 23% at 30 min (p = 0.046) and 17% at 60 min (p = 0.12); and after 250 ml it was 15% at 30 min (p = 0.012) and 7% at 60 min (p = 0.05). Ingestion of 500 ml water caused a small, non-significant, increase in mean HVPG. Plasma glucagon levels increased significantly at 30 and 60 min after the protein meal, but did not change significantly after the non-protein meal or water. Both protein-containing and non-protein meals significantly elevate HVPG in alcoholic patients with cirrhosis and portal hypertension.
Adult↗
An assessment of the sensitivity of in vivo 31P nuclear magnetic resonance spectroscopy as a means of detecting pH heterogeneity in tumours: a simulation study.
The presence of hypoxia and low pH in tumours is known to influence several treatment modalities including radiotherapy, chemotherapy and hyperthermia. Hypoxic and acidic regions have been demonstrated in tumours using pH and pO2 microelectrodes. The technique has shown marked heterogeneity within individual tumours. A non-invasive measure of intracellular pH is provided by 31P nuclear magnetic resonance (NMR) spectroscopy from determination of the chemical shift of inorganic phosphate, and is being increasingly applied to the study of human tumours in vivo. Based upon the assumption that hypoxic cells are also acidic, we have assessed the ability of a whole-body NMR spectrometer to detect acidic subpopulations within a tumour using simulated tumour spectra. In these simulations the size of the acidic subpopulation, assigned pH values from 5.0 to 7.0, was varied between 5% and 50% of the neutral "control" population. Gaussian noise was added to the simulated spectra giving signal-to-noise ratios for the neutral control inorganic phosphate peak of 3, 5 and 7, which are typical of values encountered in human tumour measurements. From the results of the simulations it seems unlikely that human hypoxic, and presumably acidic, cell fractions, typically 1-15%, will be detected by this method in the presence of signal-to-noise levels characteristic of current equipment. Therefore, whole-body in vivo 31P NMR spectroscopy may fail to identify significant pH heterogeneity within human tumours. Improvements in signal-to-noise and line separation owing to improvements in technique and higher field strength instruments may improve sensitivity to heterogeneous populations.
Cell Hypoxia↗
In-vivo 31P magnetic resonance spectroscopy for monitoring treatment response in breast cancer.
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Antineoplastic Combined Chemotherapy Protocols↗
Direct solid-phase enzymoimmunoassay of testosterone in saliva.
This competitive, solid-phase enzymoimmunoassay for testosterone in saliva is carried out on microtiter plates and involves no chromatographic or extraction steps. With an overnight incubation the detection limit of the assay is 230 fg per well (16.1 pmol/L). There was a good correlation (correlation coefficient 0.95) between testosterone concentrations measured with and without prior extraction of the saliva samples. Repeated assay of three control saliva samples containing a range of testosterone concentrations (200-1000 pmol/L) gave within- and between-assay coefficients of variation of 5.5-13.2%. The analytical procedure is simple and closely resembles already published procedures for the determination of progesterone and estrone (with extraction) in saliva. One person can assay 200 samples in 24 h and the assay is suitable for reproductive and sports medical applications, particularly for projects involving serial sampling and yielding large numbers of samples.
Adolescent↗
Influence of dietary sodium intake on urinary calcium excretion in selected Irish individuals.
The relationship between dietary sodium intake (as assessed by the 24-h urinary excretion of sodium) and urinary calcium excretion was examined in a selected group of free-living Irish individuals (n = 94), under conditions in which the completeness of urine collections was assessed. Results indicated that there was a significant positive correlation between 24-h urinary sodium and calcium excretion for males (r = 0.56, P less than 0.001) and females (r = 0.35, P less than 0.01). In addition, linear regression analysis indicated that mean 24-h urinary calcium excretion increased by 39 mg and 26 mg for a 1 g increment in sodium intake for males and females, respectively. The relationship between dietary sodium intake and urinary calcium excretion was also examined in 12 healthy young adults under controlled dietary conditions. Urinary sodium and calcium excretion values over 24 h were positively correlated for males (r = 0.44, P less than 0.05) and females (r = 0.80, P less than 0.001). However, the relationship was only statistically significant for 5 of the 12 subjects when the data were analysed on an individual basis. Results of this study suggest that salt intake may be an important determinant of urinary calcium loss in certain individuals and, as such, may be a risk factor in the development of osteoporosis. However, further studies are required to establish whether low salt intakes have a beneficial effect on calcium balance in free-living individuals.
Adult↗
The effect of guar gum on carbohydrate-, fat- and protein-stimulated gut hormone secretion: modification of postprandial gastric inhibitory polypeptide and gastrin responses.
The effect of incorporating guar gum into predominantly single-component meals of carbohydrate, fat or protein on liquid gastric emptying and on the secretion of gastric inhibitory polypeptide (GIP), gastrin and motilin, was studied in healthy human volunteers. Volunteers were given either 80 ml Hycal (carbohydrate meal), 150 g cooked lean minced beef (protein meal) or 200 ml double cream (fat meal) either with or without 5 or 6 g guar gum. Liquid gastric emptying was monitored in the fat and protein meals by taking 1.5 g paracetamol, consumed in water, with the meals and monitoring its appearance in circulation. Postprandial insulin and GIP levels were both significantly reduced by addition of guar gum to the carbohydrate meal. Postprandial GIP secretion was also reduced by addition of guar gum to the protein meal, but protein-stimulated gastrin secretion was enhanced by guar gum. There was a significant negative correlation between peak circulating gastrin levels and the corresponding GIP levels. Postprandial GIP secretion and plasma motilin levels were unaffected by addition of guar gum to the fat meal. 5 and 10 g guar gum/l solutions in water possessed buffering capacities between pH 2.75 and 5.5. Guar gum at 5 g/l caused no detectable change in liquid gastric-emptying time. The observed augmentation of gastrin secretion by guar gum following a protein meal could be due either to the buffering capacity of guar gum or to the attenuation of GIP secretion. It is possible that the chronic use of guar gum could be associated with changes in gastric acid secretion.
Adult↗
Installation of an ambient-temperature control system in a 1.5-tesla whole body system to facilitate animal studies.
An ambient-temperature control system, designed to maintain small, anaesthetized animals at physiological temperatures during long examination times, is described. The system is suitable for installation in large bore, whole-body magnets and can be positioned close to the animal under study. Design details and a description of the equipment used is given. The system proved to be satisfactory in maintaining mice at physiological temperatures.
Animals↗