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Biomedical subjects

G Pritchard

Publications and source records attributed to G Pritchard.

18 recordsLinked to original sources
PubMed2007

Using ultrasonic fetal size measurements to estimate gestational age in Brisbane, Australia.

The purpose of this paper was to construct population-specific charts of gestational age (GA) from antenatal ultrasound biometry assessment using a large sample of normal Australian pregnancies when examination was carried out to a standard protocol by experienced operators. All consenting eligible women attending a large Brisbane clinic between January 1993 and April 2003 with GA between 15 and 41 weeks, determined before examination from the last menstrual period date and concordant with the biometric-derived gestation published within the Australian Society for Ultrasound in Medicine (ASUM) policies and statements, were recruited into the prospective study if fulfilling the inclusion criteria. Biparietal diameter, femur length, abdominal circumference and head circumference measurements were recorded using ASUM standard protocol for mid and third trimester obstetric morphology scans. Statistical analyses were carried out using polynomial regression models and thorough diagnostic checks were undertaken. Included within the study were separate scans for 20,555 pregnancies from 17,660 women. Equations, means and 95% reference intervals for GA were derived for each sonographic measurement. These new population-specific regression equations complement those previously published in the same sample of Australian pregnancies. Once validated, we believe they should form the basis of a new Australian standard for ASUM.

Adult↗
PubMed2004

Reticular basement membrane thickening in airways of lung transplant recipients is not affected by inhaled corticosteroids.

INTRODUCTION: Chronic rejection is a major problem for all lung transplant programmes, which is functionally manifested by fixed airflow limitation, Bronchiolitis Obliterans Syndrome (BOS). The inclusion of a Pre-BOS category, BOS(0 approximately p), in newly revised guidelines, recognizes the potential importance of early changes. We have previously demonstrated reticular basement membrane (Rbm) thickening in clinically stable lung transplant recipients free from BOS. The present study extends this, testing the hypothesis that inhaled corticosteroid (ICS) therapy will lead to a decrease in Rbm thickness in lung transplant recipients. METHODS: A parallel group, bronchoscopic intervention study of clinically stable lung allograft recipients, free from BOS, but with evidence of airway inflammation. Following baseline assessment of Rbm thickening, subjects were randomized to 3 months of either chlorofluorocarbon-driven beclomethasone diproprionate (BDP) 400 microg b.i.d., or a formulation designed to yield at least an equivalent dose, hydrofluoroalkane-driven BDP, 200 microg b.i.d. RESULTS: Three months treatment with a moderate dose of ICS, including a formulation designed for preferential small airway deposition, had no effect on Rbm thickening (13+/-3 vs. 14+/-5 microm post-ICS). CONCLUSION: Our data would suggest that airway remodelling can occur early in lung allografts and is not affected by moderate dose ICS therapy. Longitudinal studies are required to describe the pathophysiological processes involved in BOS, and specifically to elucidate potential relationships between airway remodelling, airflow obstruction and allograft failure.

Adolescent↗
PubMed2004

Ultrasonic fetal size measurements in Brisbane, Australia.

The purpose of this paper was to construct population-specific charts of fetal biometry for 11-41 weeks gestation in relation to known gestational age from a large population of normal Australian pregnancies when examination is performed to a standard protocol by experienced operators. All consenting eligible women attending a large Brisbane clinic between January 1993 and April 2003 were recruited. Menstrual history was taken prior to examination. Measurements were performed to a standard protocol. Prospective assessment was made about the association between gestational age from the last menstrual period and biometry. Exclusion principles were applied. Statistical analyses were performed using polynomial regression models and thorough diagnostic checks were undertaken. Included within the study were separate scans for 20 555 pregnancies from 17 660 women. Equations, means and 95th reference intervals were derived and reported for the following sonographic measurements: biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Population-specific regression equations for BPD, HC, AC and FL have been proposed for Australian pregnancies. Once validated by others, we believe they will warrant consideration for adoption by the Australasian Society for Ultrasound in Medicine.

Australia↗
PubMed2004

Objective assessment of criteria for selection of donor lungs suitable for transplantation.

BACKGROUND: Donor organ shortage severely limits lung transplantation as a therapeutic option, yet many potential donor lungs are deemed unsuitable by clinical selection criteria. METHODS: Of 39 consecutive potential donor lungs, 14 were accepted and 25 excluded by clinical selection criteria. All were evaluated prospectively by clinical assessment, bronchoscopy, and bronchoalveolar lavage (BAL) to evaluate objectively the discrimination of pulmonary infection and injury. RESULTS: Accepted donors were significantly younger than those excluded (mean (SD) age 36.7 (15.3) years v 49.5 (13.2) years; p = 0.009, unpaired t test) and were more likely to have suffered traumatic brain death (50% v 20%; p = 0.07, Fisher's exact test). Oxygenation (PaO(2):FiO(2)) was higher in accepted donors than in excluded donors (median (range) 63.2 (48-82.5) kPa v 43.1 (7.7-71.7) kPa; p = 0.0001, Mann-Whitney test). Positive formal BAL culture was more frequent in accepted donors (75%) than in those excluded (43%; p = 0.1, Fisher's exact test). There was no significant difference in the percentage and concentration of neutrophils in BAL fluid between accepted and excluded donors (median (range) 37.9 (0-96.9)% and 44.6 (0-1190)x10(3)/ml v 36 (1-98.1)% and 46 (0.2-1457)x10(3)/ml), nor in the BAL fluid concentration of tumour necrosis factor-alpha (140 (0-340) pg/ml v 160 (0-760) pg/ml) or interleukin 8 (810 (33-17 600) pg/ml v 540 (0-15 110) pg/ml). CONCLUSION: Current selection criteria are poor discriminators of pulmonary injury and infection and lead to the exclusion of potentially usable donor lungs.

Adult↗
PubMed2003

Preliminary findings of quorum signal molecules in clinically stable lung allograft recipients.

BACKGROUND: Infection with bacteria such as Pseudomonas is common in lung allograft recipients, particularly during chronic rejection. Analysis of sputum samples from patients with cystic fibrosis infected with Pseudomonas aeruginosa or Burkholderia cepacia has indicated the presence of bacterial N-acylhomoserine lactones (AHLs) quorum sensing signalling molecules. AHLs not only control the expression of bacterial virulence genes but are also involved in stimulating the maturation of antibiotic resistant biofilms and host chemokine release. It was hypothesised that AHLs may be detected even in clinically stable lung transplant recipients free of clinical infection or rejection. METHODS: Three 60 ml samples of bronchoalveolar lavage (BAL) fluid were taken from nine stable lung transplant recipients 3-12 months after transplantation. Detection of AHLs was carried out on dichloromethane extracted supernatants using the bioluminescence based AHL reporter plasmid pSB1075. This responds to the presence of AHLs with long acyl chains (C10-C14), generating light. Synthetic AHLs were included as positive controls. RESULTS: Five of the nine BAL fluid supernatants exhibited AHL activity, suggesting the presence of AHLs with long N-acyl chains. There was no correlation between the levels of AHLs detected or their absence and BAL fluid microbiology or diagnosis before transplantation. CONCLUSIONS: This is the first evidence for the presence of AHL quorum sensing signals in human lung allograft recipients, even in subjects with no rejection or apparent infection. Further longitudinal follow up of these preliminary findings is required to elucidate potential links with infection, rejection, and allograft deterioration.

Bronchoalveolar Lavage Fluid↗
PubMed1999

Clopidogrel bioavailability: absence of influence of food or antacids.

Two open, randomized, crossover bioavailability studies were carried out to assess the influence of concurrent antacid medication and food on the bioavailability of clopidogrel. A fed/fasting study was conducted in 12 elderly male subjects. Each subject took a single 75 mg dose of clopidogrel on two occasions-in the morning after an overnight fast, either during a standardized breakfast, or with breakfast delayed by 4 hours after dosing. A washout period of 7 days was observed between the two dosings. Twelve healthy male subjects participated in the antacid study. They fasted overnight and for 4 hours after dosing and took a single 75 mg dose of clopidogrel at 8:00 a.m. on two occasions separated by a washout period of 14 days. For one dose, Maalox 2 x 400 mg tablets were taken 1 hour before the clopidogrel dose. Pharmacokinetic parameters of SR26334, the main circulating metabolite of clopidogrel, were derived from plasma concentrations of the latter compound determined before and at regular intervals over 36 hours after dosing. For the fed/fasting study, mean Cmax values (+/-SD) were 2.7+/-0.62 mg/L and 2.1+/-0.96 mg/L for the fasting state and the fed state, respectively and the 90% CI of Cmax ratio was [0.57 - 0.97]. Mean AUC(0-obs) values (AUC to the last observed value) were 7.1+/-1.6 mg.h/L and 7.4+/-1.64 mg.h/L, respectively, and the 90% Cl of AUC ratios were [0.90 - 1.02] and [0.89 - 0.97], respectively. For the antacid study, mean Cmax values were 2.6+/-0.84 mg/L and 2.5+/-0.87 mg/L for the no-antacid regimen and the antacid regimen, respectively, and the 90% CI of Cmax ratio was [0.74 - 1.16]. Mean AUC(0-obs) values were 6.3+/-1.34 mg.h/L and 5.8+/-1.33 mg.h/L, respectively, and the 90% CI of AUC ratios was [0.89+/-0.97]. Thus, exposure to SR26334, and therefore net absorption of clopidogrel, was not significantly modified by food or by prior antacid ingestion.

Adolescent↗
PubMed1997

Do trandolapril and indomethacin influence renal function and renal functional reserve in hypertensive patients?

AIMS: To assess the effect of trandolapril (2 mg once daily) and indomethacin (25 mg three times daily), alone and in combination, on renal function and renal functional reserve in hypertensive patients (DBP 95-115 mmHg) requiring regular non-steroidal anti-inflammatory drugs (NSAIDs). METHODS: Randomized, double-blind, placebo-controlled, four way crossover design. After 3 weeks treatment renal plasma flow (RPF) and glomerular filtration rate (GFR) were measured using the p-aminohippurate (PAH) and inulin methods. Renal functional reserve was estimated by measuring RPF and GFR at the end of an intravenous infusion of dopamine 2 microg kg(-1) and 10% amino acid solution. RESULTS: There was no significant difference in RPF between treatments: -22.79 ml min(-1) (95% CI -54.82, 9.24) for placebo and trandolapril, -10.37 ml min(-1) (95% CI -30.7, 9.96) for placebo and indomethacin, -14.78 ml min(-1) (95% CI -50.33, 20.77) for placebo and trandolapril with indomethacin. There was no significant difference in functional reserve RPF between treatments: -34.96 ml min(-1) (95% CI -119.8, 49.88) for placebo and trandolapril, 29.78 ml min(-1), -15.18, 74.74) for placebo and indomethacin, and -25.84 ml min(-1) (95% CI -87.62, 35.94) for placebo and trandolapril with indomethacin. There was no significant difference in GFR between treatments: -1.01 ml min(-1) (95% CI -7.45, 5.42) for placebo and trandolapril, -7.88 ml min(-1) (95% CI -15.08, -0.68) for placebo and indomethacin, and -0.36 ml min(-1) (95% CI -7.58, 6.86) for placebo and trandolapril with indomethacin. There was no significant difference in functional reserve GFR between treatments: 5.13 ml min(-1) (95% CI -4.97, 15.23) for placebo and trandolapril, 6.31 ml min(-1) (95% CI -1.88, 14.5) for placebo and indomethacin, 7.21 ml min(-1) (95% CI 1.26, 13.16) for placebo and trandolapril with indomethacin. CONCLUSION: In hypertensives chronic treatment with NSAIDs or ACEI alone or in combination did not change RPF or GFR and did not change renal functional reserve capacity of RPF or GFR.

Adult↗
PubMed1996

Indomethacin does not attenuate the hypotensive effect of trandolapril.

This is a randomised, double-blind, placebo-controlled, four-way crossover study to determine if indomethacin attenuates the hypotensive effect of trandolapril. Twenty-three hypertensive patients (diastolic blood pressure (DBP) 95-115) requiring NSAID were recruited. Seventeen completed the study. Three week treatment periods: trandolapril 2 mg od and indomethacin 25 mg tds, trandolapril 2 mg and placebo, indomethacin and placebo, placebo and placebo. Clinic and ambulatory BP after 3 weeks of each treatment. Study had 85% power to detect a 5 mm Hg difference in BP (s.d. 7 mm Hg). End of treatment clinic BPs were: 152.9/98 mm Hg (95% CI 147.2, 158.6/95.8, 101.4) with placebo and placebo; 150.4/94.9 mm Hg (95% CI 144.7, 156.1/92.1, 97.7) with trandolapril and indomethacin; 148.2/96.5 mm Hg (95% CI 142.5, 153.9/93.7, 99.3) with trandolapril and placebo; and 156.6/97.4 mm Hg (95% CI 150.9, 162.3/94.6, 100.2) with indomethacin and placebo. There were no significant interactions between trandolapril and indomethacin for clinic systolic BP (SBP) (P = 0.79) or clinic DBP (P = 0.87). When trandolapril treatments (placebo or with indomethacin) were compared to treatments without trandolapril (placebo or indomethacin), trandolapril lowered clinic SBP by 5.4 mm Hg (P = 0.047) and DBP by 2.3 mm Hg (P = 0.08). Mean ambulatory BP was: 140.6/88.2 mm Hg (trandolapril and placebo); 142.8/89.7 mm Hg (trandolapril and indomethacin); 149.6/95.0 mm Hg, (indomethacin and placebo); 147.7/94.0 mm Hg (placebo and placebo). Compared with placebo, trandolapril and placebo lowered BP by 6.5/7.5 mm Hg (P < 0.001, SBP; P < 0.001, DBP). Compared with indomethacin, trandolapril and indomethacin lowered BP by 5.0/5.5 mm Hg (P = 0.001, SBP; P < 0.001, DBP). In the present study trandolapril 2 mg lowered clinic SBP and ambulatory BP, but indomethacin did not attenuate this. Indomethacin had no significant effect on either clinic or ambulatory BP. The antihypertensive effects of trandolapril in this study were modest. Patient selection factors may have contributed to the observed responses, but it seems unlikely from these data that a clinically important drug interaction has occurred.

Adult↗
PubMed1990

A randomized trial of dietary intervention with essential fatty acids in patients with categorized cysts.

Two hundred women with breast cysts proven by aspiration were entered into a randomized double-blind trial of Efamol (evening primrose oil) at a dose of 6 capsules daily or equivalent placebo dose for a year. Cysts were categorized by initial electrolyte composition, and follow-up continued for 1 year posttherapy. Recurrent cyst formation in the first year was slightly (but not significantly) lower in the Efamol group compared with the placebo-treated group. The Efamol treatment was well tolerated as the dropout rate was only 7% and equal in both the active and placebo groups. The initial electrolyte composition did not predict for cyst recurrence.

Adult↗
PubMed1983

Buerger's disease of the sigmoid colon.

Buerger's disease of the sigmoid colon is reported. This is an unusual site of involvement by the disease. Review of the literature has revealed only four other cases.

Colon, Sigmoid↗
PubMed1983

Prevalence of chlamydial infection in promiscuous women.

Chlamydia trachomatis was isolated from the cervix of 18 (33%) of 55 women who admitted to two or more casual sexual contacts to one (3%) of 32 women who admitted to one casual contact in the preceding month. The chlamydial infections did not produce characteristic clinical features. Since promiscuous women are at high risk of acquiring chlamydial infection, they should be regarded as a priority group when resources for chlamydial isolation are limited.

Chlamydia Infections↗