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Biomedical subjects

M Arrowood

Publications and source records attributed to M Arrowood.

12 recordsLinked to original sources
PubMed2006

An outbreak of Cryptosporidium hominis infection at an Illinois recreational waterpark.

Cryptosporidium has become increasingly recognized as a pathogen responsible for outbreaks of diarrhoeal illness in both immunocompetent and immunocompromised persons. In August 2001, an Illinois hospital reported a cryptosporidiosis cluster potentially linked to a local waterpark. There were 358 case-patients identified. We conducted community-based and waterpark-based case-control studies to examine potential sources of the outbreak. We collected stool specimens from ill persons and pool water samples for microscopy and molecular analysis. Laboratory-confirmed case-patients (n=77) were more likely to have attended the waterpark [odds ratio (OR) 16.0, 95% confidence interval (CI) 3.8-66.8], had pool water in the mouth (OR 6.0, 95% CI 1.3-26.8), and swallowed pool water (OR 4.5, 95% CI 1.5-13.3) than age-matched controls. Cryptosporidium was found in stool specimens and pool water samples. The chlorine resistance of oocysts, frequent swimming exposures, high bather densities, heavy usage by diaper-aged children, and increased recognition and reporting of outbreaks are likely to have contributed to the increasing trend in number of swimming pool-associated outbreaks of cryptosporidiosis. Recommendations for disease prevention include alteration of pool design to separate toddler pool filtration systems from other pools. Implementation of education programmes could reduce the risk of faecal contamination and disease transmission.

Adolescent↗
PubMed2001

Immunoassay for viable Cryptosporidium parvum oocysts in turbid environmental water samples.

Cryptosporidium parvum oocysts in drinking water have been implicated in outbreaks of diarrheal disease. Current methods for monitoring environmental exposures to C. parvum only account for total number of oocysts without regard for the viability of the parasite. Measurement of oocyst viability, as indicated by an oocyst's ability to excyst, is useful because over time oocysts lose the ability to excyst and become noninfective. Thus, correlating the number of viable oocysts in drinking water with incidence and risk for disease should be more reliable than using the total number of oocysts. We have developed a quantitative assay capable of detecting low numbers of excystable, sporozoite-releasing C. parvum oocysts in turbid water samples. Monoclonal (CP7) and polyclonal antibodies have been developed against a sporozoite antigen released only during excystation or when the oocyst is mechanically disrupted. CP7 is specific for C. parvum and does not react with C. baileyi, C. muris, C. serpentis, Giardia spp., Eimeria spp., or E. nieschulzi. In this assay, oocysts in the test sample are first excysted and then centrifuged. The soluble sporozoite antigen is captured by CP7 attached to a magnetic bead. The captured antigen is then detected by ruthenium-labeled polyclonal antibodies via electrochemiluminescence. The CP7 viability assay can detect as few as 50 viable oocysts in a 1-ml assay sample with a turbidity as high as 200 Nephelometric turbidity units. This sensitive, turbidity-tolerant assay for oocyst viability may permit a better assessment of the disease risk associated with the presence of environmental oocysts.

Animals↗
PubMed2000

Left internal mammary artery intervention: the left radial approach with a new guide catheter.

Coronary intervention involving left internal mammary bypass grafts is an increasingly common challenge for the interventionalist. Although successful in a high percentage of patients, the femoral approach may be technically challenging. The shorter, more direct approach from the left radial artery has potential advantages in these cases. The present study evaluated our experience using a new left transradial internal mammary guide catheter. Angiography alone was successfully performed with the catheter in 40 patients. In an additional 10 patients, internal mammary artery interventional procedures were performed. Angioplasty alone was performed in five patients. Five patients underwent coronary stenting within the internal mammary artery or native left anterior descending artery. Guide catheter backup was satisfactory and angioplasty catheters and/or stents could be advanced to the target lesion with minimal difficulty. No procedural complications occurred. The left radial artery access site is an excellent approach for left internal mammary intervention.

Angioplasty, Balloon, Coronary↗
PubMed1999

Genetic diversity within Cryptosporidium parvum and related Cryptosporidium species.

To assess the genetic diversity in Cryptosporidium parvum, we have sequenced the small subunit (SSU) rRNA gene of seven Cryptosporidium spp., various isolates of C. parvum from eight hosts, and a Cryptosporidium isolate from a desert monitor. Phylogenetic analysis of the SSU rRNA sequences confirmed the multispecies nature of the genus Cryptosporidium, with at least four distinct species (C. parvum, C. baileyi, C. muris, and C. serpentis). Other species previously defined by biologic characteristics, including C. wrairi, C. meleagridis, and C. felis, and the desert monitor isolate, clustered together or within C. parvum. Extensive genetic diversities were present among C. parvum isolates from humans, calves, pigs, dogs, mice, ferrets, marsupials, and a monkey. In general, specific genotypes were associated with specific host species. A PCR-restriction fragment length polymorphism technique previously developed by us could differentiate most Cryptosporidium spp. and C. parvum genotypes, but sequence analysis of the PCR product was needed to differentiate C. wrairi and C. meleagridis from some of the C. parvum genotypes. These results indicate a need for revision in the taxonomy and assessment of the zoonotic potential of some animal C. parvum isolates.

Animals↗
PubMed1998

Stenting in acute coronary syndromes: a comparison of radial versus femoral access sites.

OBJECTIVES: The purpose of the present study was to compare the radial approach with the femoral approach for coronary stenting in patients with acute coronary syndromes. BACKGROUND: Aggressive anticoagulation in patients with acute coronary syndromes increases the risk of femoral vascular complications. The transradial approach has the potential to significantly reduce the incidence of access site bleeding complications in this group of patients. METHODS: One hundred forty-two patients with acute coronary syndromes undergoing coronary stenting were prospectively randomized to have their procedure performed from either the radial or femoral access site and the results compared. RESULTS: Nine of 74 patients randomized to the radial group crossed over to the femoral group (6 negative Allen tests, 3 access failures). Patient demographics were the same in both groups. Primary success was identical: 96% radial, 96% femoral, ns. There were no procedural myocardial infarctions or deaths, and no patient was referred for emergency bypass surgery. There were no access site bleeding complications in the radial group as opposed to 3 (4%) in the femoral group, p < 0.01. Postprocedure length of stay, days (1.4+/-0.2 radial vs. 2.3+/-0.4 femoral, p < 0.01) as well as total hospital length of stay (3.0+/-0.3 radial vs. 4.5+/-0.5 femoral, p < 0.01) were significantly reduced in the radial group. Total hospital charge was also significantly lower in the radial group ($20,476+/-811 radial versus $23,389+/-1,180 femoral, p < 0.01). CONCLUSION: Coronary stenting from the radial approach is efficacious in patients with acute coronary syndromes. Access site bleeding complications are less, and early ambulation results in a shorter hospital length of stay. There was a 15% reduction in total hospital charge in the radial group.

Aged↗
PubMed1997

Inactivation of Cryptosporidium parvum oocysts and Clostridium perfringens spores by a mixed-oxidant disinfectant and by free chlorine.

Cryptosporidium parvum oocysts and Clostridium perfringens spores are very resistant to chlorine and other drinking-water disinfectants. Clostridium perfringens spores have been suggested as a surrogate indicator of disinfectant activity against Cryptosporidium parvum and other hardy pathogens in water. In this study, an alternative disinfectant system consisting of an electrochemically produced mixed-oxidant solution (MIOX; LATA Inc.) was evaluated for inactivation of both Cryptosporidium parvum oocysts and Clostridium perfringens spores. The disinfection efficacy of the mixed-oxidant solution was compared to that of free chlorine on the basis of equal weight per volume concentrations of total oxidants. Batch inactivation experiments were done on purified oocysts and spores in buffered, oxidant demand-free water at pH 7 an 25 degrees C by using a disinfectant dose of 5 mg/liter and contact times of up to 24 h. The mixed-oxidant solution was considerably more effective than free chlorine in activating both microorganisms. A 5-mg/liter dose of mixed oxidants produced a > 3-log10-unit (> 99.9%) inactivation of Cryptosporidium parvum oocysts and Clostridium perfringens spores in 4 h. Free chlorine produce no measurable inactivation of Cryptosporidium parvum oocysts by 4 or 24 h, although Clostridium perfringens spores were inactivated by 1.4 log10 units after 4 h. The on-site generation of mixed oxidants may be a practical and cost-effective system of drinking water disinfection protecting against even the most resistant pathogens, including Cryptosporidium oocysts.

Animals↗
PubMed1996

Operator Radiation Exposure in PTCA: Comparison of Radial and Femoral Approaches.

In order to evaluate the radiation risk associated with PTCA from the right radial approach, operator radiation exposure was prospectively measured in 138 patients (pts) undergoing PTCA from the radial artery approach and in 126 patients from the femoral artery approach. Standard overhead and side table lead curtain shields were used in the femoral group and radial group I (66 pts). In radial group II (72 pts), a movable floor shield was added to the procedure for additional radiation protection. The external whole body dose was measured monthly using film dosimeters. Dose per case and dose per minute of fluoroscopy time were calculated. Operator external whole body dose was significantly higher when PTCA is performed from the radial artery (13.5 +/- 2.1 mrem/case) as compared to the femoral artery (8.8 +/- 1.3 mrem/case) approach (p <.01). This increased radiation exposure was reduced to less than the femoral artery when the movable floor shield is added to standard x-ray protection (3.3 +/- 2.3 mrem/case, p <.01 vs. femoral). Thus, PTCA can be performed from the radial artery approach without increased operator radiation exposure.

Journal Article↗
PubMed1996

Clinical Evaluation of Current Stent Deployment Strategies.

BACKGROUND: Coronary stenting has been demonstrated to reduce the incidence of abrupt closure and restenosis. However, intensive anticoagulation regimens have increased the number of vascular complications and hospital length of stay. Consequently, the potential long-term cost effectiveness of stenting has been jeopardized by a significant increase in procedural and hospital costs. These drawbacks have resulted in evaluation of reduced anticoagulation programs and alternative access sites. METHODS: Access-site and anticoagulation strategies were analyzed in 377 patients who had undergone coronary stenting. Four groups were compared: 114 patients stented from the femoral artery and treated with warfarin, 87 patients stented from the radial artery and treated with warfarin, 88 patients stented from the femoral artery and treated with ticlopidine and aspirin anticoagulation, and 88 patients stented from the radial artery and treated with ticlopidine and aspirin. RESULTS: Primary success was similar in all groups. Subacute closure occurred only in the groups managed with warfarin. Access-site complications occurred only in the groups with femoral access. Total hospital and post-procedure length of stay and total hospital charge were significantly less in the ticlopidine groups. The radial/ticlopidine group was the most cost-effective. CONCLUSIONS: Ticlopidine/aspirin therapy following coronary stenting from either the femoral or radial approach reduced hospital length of stay and hospital charge without subacute closure. Access-site complications were not reduced by femoral/ticlopidine strategy but were eliminated by the radial approach with either anticoagulation regimen. The radial/ticlopidine strategy eliminated access-site complications and significantly reduced hospital length of stay and hospital charge as compared to femoral/ticlopidine and was the most cost-effective strategy.

Journal Article↗
PubMed1996

Right Radial Access for PTCA: A Prospective Study Demonstrates Reduced Complications and Hospital Charges.

OBJECTIVE: The purpose of the present study was to evaluate the hypothesis that angioplasty from the radial artery approach is more cost effective than that from the femoral artery approach. BACKGROUND: Previous studies have demonstrated that angioplasty can safely and effectively be performed from the radial artery approach with a virtual absence of access-site complications. METHODS: One-hundred fifty-two patients were prospectively randomized to have their angioplasty performed from either the radial or femoral approach. Angioplasty results as well as various cost factors were compared. RESULTS: Primary success, number of stents deployed, emergency bypass surgery, PTCA time, fluoroscopy time, amount of contrast media, and catheterization laboratory charge were not significantly different in the two groups. Access-site complications (0 RRA vs. 4 RFA, p <.04), post-procedure length of stay (2.1 days +/- 0.1 RRA vs. 2.6 +/- 0.3 RFA, p <.04), total hospital length of stay (3.6 days +/- 0.2 RRA vs. 4.5 +/- 0.4 RFA, p <.03), and total hospital charge ($14,374 +/- 467 RRA vs. 15,796 +/- 702, p <.05) were all significantly less in the radial group. CONCLUSION: PTCA can be performed from RRA as effectively as RFA without clinically significant access-site complications. Both post-procedure and total hospital stay are reduced, leading to a 9% reduction in total hospital charges.

Journal Article↗
PubMed1995

PTCA using the right radial artery access site.

UNLABELLED: In order to evaluate the right radial artery approach (RRA) in PTCA, our first 50 patients (pts) who had undergone PTCA from this access site were evaluated. Seventy-eight percent of pts were male, 68% had unstable angina or recent MI. Seventy-seven lesions were dilated (31 type A, 32 type B, 13 type C). Access time was 4.3 +/- 2.4 minutes (min). Six French Voda and multipurpose guide catheters were primarily utilized (mean 1.2 guides/case). Several different balloon types were used satisfactorily (mean 1.5 balloons/case). Sheaths were pulled 3.4 +/- 1.2 hours post-procedure when ACT was less than 200 seconds. Compression time was 24.8 +/- 11 and heparin was immediately resumed. No access site complications occurred. Results were compared to a cohort of 100 pts who had undergone PTCA from the right femoral artery approach (RFA). PTCA time, fluoroscopy time, contrast utilized, primary success rate, emergency bypass and cath lab charges were the same in both groups. Access site complications were significantly less in the right radial group (0 RRA vs. 4 RFA, p < .02). Post PTCA length of stay (1.9 +/- 0.3 vs. 3.4 +/- 0.6, p < .05) and total hospital length of stay (3.7 +/- 0.5 vs. 5.2 +/- 0.6, p < .05) were significantly less in the radial group. As a result of the shorter hospital stay, total hospital charge was less in the radial group (14,730 +/- 882 vs. 17,461 +/- 908, p < .05). CONCLUSION: Results of PTCA performed from RRA are similar to those from RFA with a significant reduction in access site complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗