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Biomedical subjects

D M Murphy

Publications and source records attributed to D M Murphy.

At least 37 records · Page 2Linked to original sources
PubMed2001

Assessment of the rate of solid-phase gastric emptying in ponies by means of the 13C-octanoic acid breath test: a preliminary study.

The aim of this study was to assess the feasibility of applying the 13C-octanoic acid breath test for assessment of gastric emptying in ponies by investigating the pattern of 13C enrichment in breath following the administration of a test meal +/- 13C-octanoic acid. After a 14 h fast, the ponies received either no meal (Test I) or a standardised test meal labelled with 0 mg (Test II), 125 mg (Test III), 250 mg (Test IV) or 500 mg (Test V) 13C-octanoic acid. For each test (I-V), exhaled breath samples were collected in duplicate at 1 h and immediately before ingestion of the test meal and at frequent intervals thereafter for 12 h. Breath samples were analysed by continuous flow isotope ratio mass spectrometry. Three indices of breath 13C-enrichment were computed; half dose recovery time (t1/2), gastric emptying coefficient (GEC) and time to peak breath 13C-enrichment t(max). For Tests I and II, the ratio of 13CO2:12CO2 remained stable for the duration of the sampling period. For Tests III, IV and V, an increase in the ratio of 13CO2:12CO2 was detected. The test was reproducible within individuals, and intersubject variation was low. Further validation studies of this noninvasive technique are justified.

Animal Feed↗
PubMed2000

Renal transplantation in patients with an augmentation cystoplasty.

OBJECTIVE: To retrospectively review our experience over a 10-year period of renal transplantation in patients with augmented bladders and thus assess the safety of this procedure. PATIENTS AND METHODS: Ten transplant recipients who had previously undergone augmentation cystoplasty were reviewed; a cadaveric kidney was transplant in each case. The donor ureter was anastomosed to the augment bladder in six patients, in three to the native ureter and in one the donor renal pelvis was anastomosed to the native ureter. RESULTS: No patients died and nine of the 10 grafts were functioning at a mean follow-up of 27 months. The mean (SD) serum creatinine level at the follow-up was 100.8 (27.25) mmol/L. Four patients had 10 episodes of urosepsis requiring hospital admission, with only one graft lost. CONCLUSION: Renal transplantation can be performed safely in patients with an augmentation cystoplasty.

Adolescent↗
PubMed2000

The clinical and economic impact of deep chest surgical site infections following coronary artery bypass graft surgery.

STUDY OBJECTIVES: To examine how deep chest surgical site infections following coronary artery bypass graft (CABG) surgery impact hospital inpatient length of stay (LOS), costs, and mortality. SETTING: A large, Midwestern community medical center. DESIGN: All CABG patients who developed deep chest infection (n = 41) were compared to a set of control subjects (n = 160) systematically selected as every tenth uninfected CABG patient. Clinical data were abstracted from patient records, and cost information was obtained from the cost accounting database of the hospital. RESULTS: Variables that significantly increased the risk of deep chest surgical site infection included obesity (odds ratio [OR], 11; p = 0. 0001), renal insufficiency (OR, 8.9; p = 0.0001), connective tissue disease (OR, 25.4; p = 0.0003), reexploration for bleeding (OR, 8.2; p = 0.0015), and the timing of antibiotic prophylaxis (> 60 min before incision; OR, 5.3; p = 0.0128). Within 1 year postoperatively, patients with deep chest surgical site infection had a mortality rate of 22%, vs 0.6% for uninfected patients (p = 0.0001). Infected patients also incurred an average of 20 additional hospital days (p = 0.0001). Univariate analysis indicated that patients who developed deep chest surgical site infection incurred $20,012 in additional costs in the first year (p = 0.0001). Infected patients who died incurred on average $60,547 more than infected patients who survived (p = 0.034). Multivariate analysis confirmed the magnitude of the estimate of the cost for deep chest surgical site infection ($18, 938; p = 0.0001). CONCLUSIONS: Deep chest surgical site infections following CABG surgery are associated with significant increases in LOS, hospitalization costs, and mortality. These results suggest the need for improved infection control measures to reduce deep chest surgical site infection rates.

Aged↗
PubMed1999

Artificial urinary sphincter insertion in renal transplant recipients.

The prosthetic urinary sphincter has contributed significantly to the improved management of urinary incontinence during the past 25 years. However, the safety of these devices in immunosuppressed patients is not well reported. We describe the successful insertion of the AMS 800 artificial urinary sphincter in two renal transplant recipients.

Adult↗
PubMed1999

Results of a comprehensive infection control program for reducing surgical-site infections in coronary artery bypass surgery.

OBJECTIVE: To evaluate the efficacy of a comprehensive infection control program on the reduction of surgical-site infections (SSIs) following coronary artery bypass graft (CABG) surgery. DESIGN: Prospective cohort study. SETTING: 1,000-bed tertiary-care hospital. PATIENTS: Persons undergoing CABG with or without concomitant valve surgery from April 1991 through December 1994. INTERVENTIONS: Prospective surveillance, quarterly reporting of SSI rates, chlorhexidene showers, discontinuation of shaving, administration of antibiotic prophylaxis in the holding area, elimination of ice baths for cooling of cardioplegia solution, limitation of operating room traffic, minimization of flash sterilization, and elimination of postoperative tap-water wound bathing for 96 hours. Logistic regression models were fitted to assess infection rates over time, adjusting for severity of illness, surgeon, patient characteristics, and type of surgery. RESULTS: 2,231 procedures were performed. A reduction in infection rates was noted at all sites. The rate of deep chest infections decreased from 2.6% in 1991 to 1.6% in 1994. Over the same period, the rate of leg infections decreased from 6.8% to 2.7%, and of all SSI from 12.4% to 8.9%. The adjusted odds ratio (OR) for all SSIs for the end of 1994 compared to December 31, 1991, was 0.37 (95% confidence interval [CI95], 0.22-0.63). For deep chest and mediastinal infections, the adjusted OR comparing the same period was 0.69 (CI95, 0.28-1.71). CONCLUSIONS: We observed significant reductions in SSI rates of deep and superficial sites in CABG surgery following implementation of a comprehensive infection control program. These differences remained significant when adjusted for potential confounding covariables.

Adult↗
PubMed1999

Identification and characterization of three subtypes of radiation response in normal human urothelial cultures exposed to ionizing radiation.

In an attempt to assess genetic variation underlying the variation in human responses to radiation exposure, measurements of apoptosis, necrosis and induction of key proteins were made in primary explant cultures of human normal urothelium and correlated with growth post- exposure to a range of doses of (60)Co. These data were validated by similar experiments using CBA/H and C57/BL6 mouse strains, known to exhibit genetically determined differences in response to radiation. The data for human tissues show a wide variation in response with three broad categories being identifiable. The commonest had a hypersensitive response involving considerable apoptosis in the low dose region, followed by 'induction' of a survival response at higher doses involving the persistence of abnormal cells. The pattern of gene expression was consistent with suppression of apoptosis. The second category showed no induction of survival and considerable necrosis was seen in the progeny. The rarest category showed an extremely hypersensitive low dose response and despite induction of a survival response, the sensitivity to higher doses was very severe. Considerable apoptosis and necrosis were seen in these cultures. In the mouse experiments, strain CBA/H (mice known to exhibit genetic instability post-irradiation) had lower levels of delayed cell death and apoptosis than C57/BL6 mice (which exhibit significantly less instability). It is concluded that there is a variation in response to radiation between human patient cultures which is detectable in this system and which is consistent with a pattern of radiation- induced delayed death/apoptosis correlating with long-term genomic stability. The mouse experiments demonstrate the importance of genetic factors in determining these responses.

Animals↗
PubMed1999

The role of intraoperative heparin in cyclosporine treated cadaveric renal transplant recipients.

PURPOSE: We analyze the effect of intraoperative heparin in cadaveric renal transplantation. MATERIALS AND METHODS: We examined the records of 100 consecutive cadaveric transplant recipients who received 5,000 units of heparin at the time of vascular clamping (group 1), and compared the incidence of graft thrombosis and postoperative hemorrhagic complications to 100 consecutive cadaveric transplant recipients who did not receive heparin (group 2). The groups were similar in terms of donor age, sex, number of transplant recipients, sensitization, multiple vessels, delayed graft function and human leukocyte antigen mismatch. All patients received cyclosporine based triple therapy immunosuppression. All explanted grafts were examined histologically to rule out hyperacute rejection. RESULTS: There was no statistical difference between the 2 groups. The overall incidence of graft thrombosis was 5% (6% in group 1 and 4% in group 2). There was a greater need for blood transfusion in group 1, with 25 patients requiring transfusion postoperatively versus 14 in group 2. CONCLUSIONS: Intraoperative heparin did not reduce the incidence of graft thrombosis in this retrospective study. It did increase the postoperative blood transfusion requirements. As a result of this analysis, we have abandoned its use.

Adult↗
PubMed1998

Application of liquid chromatography-mass spectrometry(n) analyses to the characterization of novel glyburide metabolites formed in vitro.

The application of bench-top ion-trap atmospheric pressure ionization mass spectrometry in the characterization of in vitro metabolites of glyburide is discussed. The metabolites formed in vitro by rat, dog, monkey and human liver microsomes were separated by reversed-phase high-performance liquid chromatography (HPLC) and characterized by mass spectrometry (MS)n experiments. The utility of data dependent MS1-MS2-MS3 analyses, where the mass spectrometer makes "real-time" decisions about the experiment to be performed, are described using the characterization of two novel metabolites of glyburide as an example. The metabolite profiles from each species were similar. Six cyclohexyl hydroxylation products were detected, as well as two novel monooxygenation products formed via hydroxylation of the ethyl chain at the benzylic position, and alpha to the amide nitrogen. The ion-trap with electrospray ionization proved to be a sensitive and reliable HPLC detection system that provided important chemical structure information.

Animals↗
PubMed1997

Experience using the Quinton Permcath for haemodialysis in the Irish Republic.

BACKGROUND: The Quinton Permcath has been widely used for temporary vascular access in patients requiring haemodialysis. Placement under direct vision into the internal jugular vein minimizes the complication rate. This access modality is being used more and more for long-term access in the elderly and in patients where other access modalities are unavailable or have failed. METHODS: We reviewed the results of 50 central venous Permcaths inserted under direct vision in 61 patients, over a 4-year period. The overall survival and complication rates are estimated. A detailed description of the catheter insertion and removal is provided. RESULTS: Seventy-six per cent of patients were successfully managed using the Permcath for a median duration of 105 days. In addition, nine patients (18%) had catheters functioning without complications for over 1 year. Twenty-six (42.6%) catheters were removed for complications. Seven patients had a single and two had second catheter reinsertion during the course of the study. CONCLUSIONS: The Quinton Permcath remains a reliable method for short-term vascular access. When other access modalities are unavailable, it may offer a valuable alternative for long-term haemodialysis.

Adolescent↗
PubMed1997

Anesthesia patient risk: a quantitative approach to organizational factors and risk management options.

The risk of death or brain damage to anesthesia patients is relatively low, particularly for healthy patients in modern hospitals. When an accident does occur, its cause is usually an error made by the anesthesiologist, either in triggering the accident sequence, or failing to take timely corrective measures. This paper presents a pilot study which explores the feasibility of extending probabilistic risk analysis (PRA) of anesthesia accidents to assess the effects of human and management components on the patient risk. We develop first a classic PRA model for the patient risk per operation. We then link the probabilities of the different accident types to their root causes using a probabilistic analysis of the performance shaping factors. These factors are described here as the "state of the anesthesiologist" characterized both in terms of alertness and competence. We then analyze the effects of different management factors that affect the state of the anesthesiologist and we compute the risk reduction benefits of several risk management policies. Our data sources include the published version of the Australian Incident Monitoring Study as well as expert opinions. We conclude that patient risk could be reduced substantially by closer supervision of residents, the use of anesthesia simulators both in training and for periodic recertification, and regular medical examinations for all anesthesiologists.

Accidents↗
PubMed1997

Report of spores of Henneguya salminicola (Myxozoa) in human stool specimens: possible source of confusion with human spermatozoa.

The spores of Henneguya salminicola, a common tissue parasite of salmonid fishes in the northern hemisphere, were observed in stool specimens from two different patients with diarrhea. The spores' superficial resemblance to human spermatozoa resulted, in one instance, in an incorrect report, leading to suspicion of sexual abuse. H. salminicola spores and human spermatozoa can be differentiated on the basis of size, morphology, and staining characteristics. Laboratory personnel who perform microscopic examinations of stool specimens for ova and parasites should be aware that spores of H. salminicola may be seen from time to time.

Animals↗
PubMed1997

Further investigation of the response of human uroepithelium to low doses of cobalt-60 gamma radiation.

Explant cultures of normal human uroepithelium were established, exposed to a range of 60Co gamma-ray doses from 0.1-5 Gy and grown for 14 days. Expression of Myc, p53 and Bc12 proteins in the epithelial cells which grew from irradiated explants was measured in situ using immunocytochemistry. The results show that overexpression of Bc12 with low Myc expression correlated with resistance to radiation as shown by the extent of growth detected on day 14. Strong staining for Myc coupled with low or absent Bc12 expression generally correlated with radiosensitivity, although the level of p53 of the culture was critical in these cases. None of the proteins on their own correlated with radiation response. What appeared to be critical was the balance of cells expressing Bc12 and Myc proteins. Building on the results presented in a previous paper which showed a division of cultures from patients into those showing monotonic and nonmonotonic responses, this study presents results for explant cultures from a greater number of patients and attempts to characterize the profile of expression of the above proteins in the uroepithelium of these patients. It shows that high Bc12/Myc ratios were found in cultures which showed a non-monotonic and resistant dose response. Where Myc was the dominant protein in the culture postirradiation, a radiosensitive and monotonic response tended to occur. Since the proteins are being detected in the distant progeny of irradiated cells, it is likely that changes induced by radiation in the cell population are stable. The measurement of these two proteins can be made in cultured biopsy material and may therefore have predictive value in radiotherapy and radiation protection. Both normal and tumor biopsies from bladder mucosa showed similar correlations between Bc12/Myc ratios and growth postirradiation.

Apoptosis↗
PubMed1996

Demonstration of a bilateral projection from the rostral nucleus of the solitary tract to the medial parabrachial nucleus in rat.

This study examined the projection from the rostral nucleus of the solitary tract (rNST) to the medial parabrachial nucleus (mPBN) in male Wistar rats using DiI as a retrograde tracer and biotinylated dextran as an anterograde tracer. Following successful unilateral injection of DiI into the mPBN (n = 8), retrogradely labeled neurons were always found in the rNST both ipsilateral and contralateral to the pontine injection site. Significantly, approximately 25% of the total number of DiI-labeled neurons were located in the contralateral rNST. The labeled neurons were located throughout the rostral-caudal extent of the rNST with the most cells being located in the central portion of the nucleus, and the fewest located ventromedially and dorsolaterally. Supporting the findings of the retrograde labeling study, axons and terminals, anterogradely labeled by injecting biotinylated dextran unilaterally into the rNST (n = 4), were always found in both the ipsilateral and contralateral mPBN. Although the intensity of anterograde labeling was higher ipsilaterally, a mirror-image staining pattern consistently was present contralaterally. These results indicate that there is a substantial contralateral component of the projection from the rNST to the mPBN. This suggests that convergence of gustatory information from the two sides of the oral cavity may occur within the pons before processing in higher brain centers. These findings may have important implications as to where and how bilateral gustatory information is processed and integrated.

Animals↗