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Biomedical subjects

M Duggan

Publications and source records attributed to M Duggan.

At least 19 recordsLinked to original sources
PubMed2006

Quantifying badger exposure and the risk of bovine tuberculosis for cattle herds in county Kilkenny, Ireland.

The objectives of the study were to quantify the levels of badger exposure for cattle and to test the hypothesis that increased badger exposure does not increase the risk of bovine tuberculosis (BTB) in a herd. Information that became available from the targeted removal of badgers over the study period, and from a badger-removal project in county Kilkenny, during 1996-1999 was used. The specific location of cattle within each farm, and the length of time that cattle spent in each farm field during the grazing season, and in the barnyard during winter, was used to build an exposure coefficient to quantify the amount of badger exposure that cattle encountered either on pasture or in the barn. The study design was a matched case-control study in which the control herds were selected using incidence density sampling. During the 4-year study period, 543 badgers were removed and of these 96 badgers were classified as tuberculosis positive; 96 BTB herd breakdowns occurred. There was a significant association between case herds and having a higher badger sett exposure coefficient during 1996-1998. No significant association between case herds and having a higher exposure coefficient based on the number of badgers, or the number of tuberculous badgers, during September 1997-December 1999 was found.

Animals↗
PubMed2004

Interferon treatment of multiple pulmonary malignancies associated with papilloma virus.

Over a period of four years, beginning in spring 1988, a previously healthy man developed a primary squamous cell carcinoma of the tonsil, treated with radiotherapy, followed by 10 distinct, primary bronchial squamous cell carcinomas. Four of the cancers were surgically resected, all of which were positive by hybridization for human papilloma virus (type 16). Following the institution of alpha interferon, three smaller lesions disappeared and a larger one shrank in size, facilitating surgical resection. Over the following seven years no new ones have appeared. The finding of papilloma virus in malignancies should prompt consideration of antiviral therapy.

Adult↗
PubMed2003

Spleen transplantation in miniature swine: surgical technique and results in major histocompatibility complex-matched donor and recipient pairs.

BACKGROUND: Spleen transplantation (Tx) between some strains of rodents can lead to donor-specific tolerance either spontaneously or after a short course of immunosuppression. This study developed a surgical technique for spleen Tx in miniature swine to investigate its immunologic impact in a large animal model. METHODS: The preferred surgical technique of spleen Tx (n=8) involved excision of the donor spleen with its vascular pedicle to the aorta and portal vein. Carrel patches of donor aorta and portal vein were anastomosed to the abdominal aorta and inferior vena cava, respectively, of the (splenectomized) recipient. The results in four major histocompatibility complex-matched pairs that were mismatched for the porcine allelic antigen are reported. Two recipients were untreated, one received a 12-day course of cyclosporine A (CsA) alone, and one received thymic irradiation (700 cGy) and CsA. Hematopoietic cell chimerism was followed by fluorescence-activated cell sorter, and graft survival was assessed by histology. RESULTS: Spleen Tx was technically successful. In two untreated pigs, chimerism was detected in the blood (maximum 5% for 17 and 25 days) and lymph nodes (maximum 6% for 28 and 56 days), but both grafts showed histologic rejection by day 28. In two treated pigs, chimerism was present in the blood for 47 and 57 days, and rejection was prevented, with follow-up for 57 and 217 days, respectively. CONCLUSION: Spleen Tx in major histocompatibility complex-matched pairs treated with CsA+/-thymic irradiation results in prolonged chimerism and is associated with the development of in vivo unresponsiveness to the transplanted spleen.

Animals↗
PubMed2000

Management of aggressive histologic variants of endometrial carcinoma at the Tom Baker Cancer Centre between 1984 and 1994.

OBJECTIVE: The aim of this study was to determine the patient characteristics and outcome of patients with aggressive histologic variants (AV) of endometrial carcinoma, including uterine papillary serous carcinoma (UPSC), uterine clear cell carcinoma (UCCC), and mixed type. METHODS AND MATERIALS: All cases with AV histological type of endometrial carcinoma from January 1984 to December 1994 at the Tom Baker Cancer Centre were identified using the Alberta Cancer Registry. Relevant data from the charts of these patients were entered into a study database (Microsoft Excel) and analyzed for presentation, demography, treatment parameters, and outcome of treatment. All pathology was reviewed at the time of diagnosis. Statistical analysis was performed using the S-plus statistics computer program. Univariate and multivariate analyses were used to assess independent prognostic factors using the Cox proportional hazards model. RESULTS: A total of 103 patients with AV histological type were identified and analyzed; there were 61, 31, and 11 cases of UPSC, CCC, and mixed tumors, respectively. Sixty-three patients had Stage I, 11 had Stage II, 15 had Stage III, and 14 had Stage IV disease. The median age of patients was 67 years with a range of 36 to 86 years. Median follow-up was 60 months with a range of 36 to 156 months. The Cox proportional hazards model showed that lymphvascular space invasion and stage are the two independent prognostic factors affecting recurrence and survival. Forty six percent of all cases underwent surgery alone, 39% underwent treatment which included pelvic RT, and 17% underwent treatment which included chemotherapy. Pelvic recurrence was reduced significantly by radiotherapy in Stages I, II, and III (19% recurrence with no RT vs 7% recurrence with RT, P < 0.005). Chemotherapy improved overall survival, but made little difference in distant relapse rates. CONCLUSIONS: Stage Ia cases treated by surgery alone have a low risk of relapse and need not be offered adjuvant systemic therapy or pelvic radiation. Patients with Ib, Ic, II, and III have significantly lower pelvic failure rates if treated with pelvic radiation, but still have a high distant failure rate. Systemic therapy did not significantly improve distant relapse-free survival, but did extend overall survival. Stage IV patients usually died within 6 months with a few responding to systemic chemotherapy. These results suggest that there is a need for randomized trials for these patients.

Adenocarcinoma, Clear Cell↗
PubMed2000

A comparison of biochemical and functional alterations of rat and human erythrocytes stored in CPDA-1 for 29 days: implications for animal models of transfusion.

Animal models of transfusion are employed in many research areas yet little is known about the storage-related changes occurring in the blood used in these studies. This study assessed storage-related changes in red blood cell (RBC) biochemistry, function and membrane deformability in rat and human packed RBCs when stored in CPDA-1 at 4 degrees C over a 4-week period. Human blood from five volunteers and five bags of rat RBC concentrates (five donor rats per bag) were collected and stored at 4 degrees C. RBC function was assessed by post-transfusion viability and the ability to regenerate adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (DPG) when treated with a rejuvenation solution. Membrane deformability was determined by a micropipette aspiration technique. ATP in rat RBCs declined more rapidly than human RBCs; after 1 week rat ATP fell to the same level as human cells after 4 weeks of storage (rat, 2.2 +/- 0.2 micromol g(-1) Hb; human, 2.5 +/- 0.3 micromol g(-1) Hb). Baseline DPG concentrations were similar in rat and human RBCs (16.2 +/- 2.3 micromol g(-1) Hb and 13.7 +/- 2.4 micromol g(-1) Hb) and declined very rapidly in both species. Human RBCs fully regenerated ATP and DPG when treated with a rejuvenation solution after 4 weeks of storage. Rat RBCs regenerated ATP but not DPG. Post-transfusion viability in rat cells was 79%, 26% and 5% after 1, 2 and 4 weeks of storage, respectively. In rats, decreased membrane deformability became significant (- 54%) after 7 days. Human RBC deformability decreased significantly by 34% after 4 weeks of storage. The rejuvenation solution restored RBC deformability to control levels in both species. Our results indicate that rat RBCs stored for 1 week in CPDA-1 develop a storage lesion similar to that of human RBCs stored for 4 weeks and underscores significant species-specific differences in the structure and metabolism of these cells.

2,3-Diphosphoglycerate↗
PubMed2000

High dose alfentanil as sole anaesthetic induction agent for caesarean section in a patient with severe ischaemic heart disease.

A 43-year-old woman presented at 34 weeks' gestation with pre-eclampsia and intra-uterine growth restriction. She had a past medical history of myocardial infarction and had angina on moderate effort. She also had non-insulin dependent diabetes mellitus, chronic obstructive airways disease and hypercholesterolaemia. The onset of unstable angina, cardiac failure and a deteriorating fetal condition necessitated urgent delivery by caesarean section. General anaesthesia was chosen. High dose alfentanil was used as sole induction agent resulting in minimal haemodynamic change and a successful maternal and fetal outcome.

Journal Article↗
PubMed2000

Effects of inhaled nitric oxide in a rat model of Pseudomonas aeruginosa pneumonia.

OBJECTIVE: Antimicrobial effects of nitric oxide (NO) have been demonstrated in vitro against a variety of infectious pathogens, yet in vivo evidence of a potential therapeutic role for exogenous NO as an antimicrobial agent is limited. Thus, we assessed the effects of inhaled NO on pulmonary infection, leukocyte infiltration, and NO synthase (NOS) activity in a rat model of Pseudomonas aeruginosa pneumonia. DESIGN: Controlled animal study. SETTING: Research laboratory of an academic institution. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: After intratracheal instillation of either P. aeruginosa or saline (sham), rats were randomly exposed to either 40 ppm of inhaled NO or room air (RA) for 24 hrs before they were killed. MEASUREMENTS AND MAIN RESULTS: Inhaled NO in pneumonia rats markedly reduced pulmonary bacterial load (0.02+/-0.01% vs. 0.99+/-0.59% of bacterial input in pneumonia with room air, p < .05) and pulmonary myeloperoxidase activity, a marker of leukocyte infiltration (21.7+/-3.8 vs. 55.0+/-8.1 units in pneumonia with room air, p < .05), but had no effect on systemic hemodynamics or gas exchange. Pneumonia was associated with enhanced pulmonary NOS activity (8.8+/-2.4 vs. 0.2+/-0.1 pmol citrulline/min/mg protein in sham, p < .01) and increased plasma levels of nitrites/nitrates (NOx-; 45+/-7 vs. 16+/-3 micromol/L in sham, p < .01). Inhaled NO therapy attenuated the pneumonia-induced increase in pulmonary calcium-independent NOS activity (p < .05) and markedly increased plasma NOx- levels. Exposure of P. aeruginosa in culture to 40 ppm of ambient NO confirmed a delayed antibacterial effect of NO in vitro. CONCLUSIONS: Inhaled NO has an important antibacterial effect both in vitro and in vivo against P. aeruginosa and is associated with reduced pulmonary leukocyte infiltration in vivo. These results in a rat model of P. aeruginosa pneumonia suggest that future studies should address the possible clinical effects of inhaled NO therapy in pneumonia.

Administration, Inhalation↗
PubMed1999

Rethinking public health: new training for new times.

The new public health agenda will require major changes in the way health authorities, local authorities, Trusts and Primary Care Groups organise and manage their activities. The requirement is for inter-agency co-ordination and inter-professional and inter-sectoral working to a shared agenda, yet the human and resources development planning to achieve these goals has not been done. This paper summarises the key training issues and argues for a collaborative, decentralised and quality assured approach to multidisciplinary public health management education and training. Only with such a joined up human resources plan can Our Healthier Nation succeed where The Health of the Nation signally failed.

Health Planning↗
PubMed1998

Adrenal failure in the critically ill.

Three critically ill patients suffered multiple organ failure secondary to sepsis. Despite adequate supportive therapy and appropriate antibiotic cover, they failed to improve and required inappropriate inotrope support. They had not been treated with steroids or other drugs known to suppress adrenal function. Adrenal insufficiency was suspected. A random cortisol concentration and a short synacthen test demonstrated concentrations below the range expected in all three cases. High-dose steroid therapy was commenced with marked improvement in the short-term. However, in each case sepsis eventually caused death.

Adrenal Insufficiency↗
PubMed1996

Contribution of consultants to care of compromised pregnancies.

Obstetricians often seek consultative services of other specialists in the management of compromised pregnancies. However, the extent of such consultations and the contribution of these consultants have not been addressed in the literature. This study is addresses the contribution of consultants to the care of complicated pregnancies at a tertiary care center. During the 2 1/2 years of this retrospective study, 2263 antepartum admissions were made for pregnancy complications. One hundred sixty-six of those patients were hospitalized 176 times and were treated by one or more consulting physicians for a consultation rate of 7.8%. Eighteen specialties were consulted, including 54 (32%) consultations from maternal fetal medicine, 44 (24%) from internal medicine, 28 (16%) from general surgery, and 22 (12%) from endocrinology. Of the initial admission diagnoses, 87.9% were confirmed and 46 new diagnoses were made by the consultants. A significant positive correlation was noted between the number of consultants, maternal length of hospital stay, and maternal hospitalization cost.

Adult↗
PubMed1996

Sarcoidosis of the pancreas: a case report.

Sarcoidosis involving the pancreas is quite rare, having been reported only 10 times in the English language literature. Its clinical presentation is often similar to pancreatic cancer, with common presenting symptoms including abdominal pain, weight loss, jaundice, and anorexia. Diagnosis has been made in all cases at laparotomy, and in the majority of cases, no previous history of sarcoidosis was reported. Treatment has ranged from observation to pancreaticoduodenectomy for suspected malignancy. Prognosis is favorable with no significant morbidity or mortality reported postoperatively. The case we report is that of a patient with a prior history of sarcoidosis who presented with a clinical picture suggestive of pancreatic malignancy. However, the patient was found to have sarcoidosis involving the pancreas, with no evidence of malignancy at laparotomy.

Cholangiography↗
PubMed1994

Pharmacokinetics and pharmacodynamics of L-703,014, a potent fibrinogen receptor antagonist, after intravenous and oral administration in the dog.

The pharmacokinetics and pharmacodynamics of L-703,014, a fibrinogen receptor antagonist, have been examined in the dog. An analytical method which utilizes methanol precipitation of dog plasma proteins followed by HPLC with an automated column switching technique using the chemical analogue L-704,326 as internal standard was developed for the determination of L-703,014 in dog plasma. The compound was not metabolized in the dog and was eliminated in the kidneys and into bile. Of the administered dose, 68.9 +/- 1.3% (i.v.) and 80.5 +/- 11.9% (p.o.) were recovered in the feces; 20.3 +/- 1.3% (i.v.) and 2.2 +/- 0.2% (p.o.) were recovered in the urine by 72 hr. L-703,014 was 23 +/- 3.4% bound in dog plasma protein and the mean ratio of plasma/whole blood was 1.22 +/- 0.05. The mean terminal half-life was 118 +/- 36 min, the mean steady-state volume of distribution was 0.61 +/- 0.22 L/kg, and the mean plasma clearance was 8 +/- 2 mL/min/kg. Ex vivo platelet aggregation measurements were made by inducing platelet aggregation with 10 micrograms/mL collagen in the presence of 1 microM epinephrine as an agonist. The mean C50 was 44.4 +/- 6.0 ng/mL, and the mean Hill coefficient was 1.5 +/- 0.3. The mean bioavailability was 4.9 +/- 1.4% in dogs administered 2.0 mg/kg (p.o.).

Administration, Oral↗