Biomedical subjects

Gregory A Wilson

Publications and source records attributed to Gregory A Wilson.

4 recordsLinked to original sources

PubMed2006

Outcomes of cardiopulmonary resuscitation and predictors of survival in patients undergoing coronary angiography including percutaneous coronary interventions.

We studied the outcome of cardiopulmonary resuscitation (CPR) in patients undergoing coronary angiography (CA) and/or percutaneous coronary interventions (PCI). Of 51,985 CA and PCI patients treated between January 1, 1990, and December 31, 2000, 114 required CPR. Records were reviewed for relationships between patient characteristics and various procedures and short-term survival. Long-term survival was compared with that of a matched cohort of patients who did not have an arrest during catheterization and a matched cohort from the general Minnesota population. Over the 11-year period, the overall incidence of CPR was 21.9 per 10,000 procedures. This rate decreased from 33.9 per 10,000 before 1995 to 13.1 per 10,000 after 1995. Overall survival to hospital discharge after CPR was 56.1%. Survival to discharge was less frequent with a history of congestive heart failure, previous coronary artery bypass graft surgery, hemodynamic instability during the procedure, and with prolonged or emergent catheterizations. Pulseless electrical activity (versus asystole or ventricular fibrillation) indicated very poor short-term survival. Interestingly, short-term survival was not related to the extent of coronary artery disease. Long-term survival of patients who survived cardiac arrest was comparable to that of those who did not have arrest during catheterization. In conclusion, the incidence of periprocedural CPR during diagnostic or interventional coronary procedures decreased after 1995. Patients who received CPR in the cardiac catheterization lab have a remarkably frequent survival to hospital discharge rate. Long-term survival of these patients is only minimally reduced.

Aged↗

PubMed2005

Phylogeographic history and gene flow among giant Galápagos tortoises on southern Isabela Island.

Volcanic islands represent excellent models with which to study the effect of vicariance on colonization and dispersal, particularly when the evolution of genetic diversity mirrors the sequence of geological events that led to island formation. Phylogeographic inference, however, can be particularly challenging for recent dispersal events within islands, where the antagonistic effects of land bridge formation and vicariance can affect movements of organisms with limited dispersal ability. We investigated levels of genetic divergence and recovered signatures of dispersal events for 631 Galápagos giant tortoises across the volcanoes of Sierra Negra and Cerro Azul on the island of Isabela. These volcanoes are among the most recent formations in the Galápagos (<0.7 million years), and previous studies based on genetic and morphological data could not recover a consistent pattern of lineage sorting. We integrated nested clade analysis of mitochondrial DNA control region sequences, to infer historical patterns of colonization, and a novel Bayesian multilocus genotyping method for recovering evidence of recent migration across volcanoes using eleven microsatellite loci. These genetic studies illuminate taxonomic distinctions as well as provide guidance to possible repatriation programs aimed at countering the rapid population declines of these spectacular animals.

Animals↗

PubMed2003

Bayesian inference of recent migration rates using multilocus genotypes.

A new Bayesian method that uses individual multilocus genotypes to estimate rates of recent immigration (over the last several generations) among populations is presented. The method also estimates the posterior probability distributions of individual immigrant ancestries, population allele frequencies, population inbreeding coefficients, and other parameters of potential interest. The method is implemented in a computer program that relies on Markov chain Monte Carlo techniques to carry out the estimation of posterior probabilities. The program can be used with allozyme, microsatellite, RFLP, SNP, and other kinds of genotype data. We relax several assumptions of early methods for detecting recent immigrants, using genotype data; most significantly, we allow genotype frequencies to deviate from Hardy-Weinberg equilibrium proportions within populations. The program is demonstrated by applying it to two recently published microsatellite data sets for populations of the plant species Centaurea corymbosa and the gray wolf species Canis lupus. A computer simulation study suggests that the program can provide highly accurate estimates of migration rates and individual migrant ancestries, given sufficient genetic differentiation among populations and sufficient numbers of marker loci.

Animal Migration↗

PubMed2003

Predictors of survival following cardiac arrest in patients undergoing noncardiac surgery: a study of 518,294 patients at a tertiary referral center.

BACKGROUND: The authors determined the incidence of cardiac arrest and predictors of survival following perioperative cardiac arrest in a large population of patients at a tertiary referral center. METHODS: Medical records of patients who experienced cardiac arrest in the perioperative period surrounding noncardiac surgery between January 1, 1990, and December 31, 2000, were reviewed. Logistic regression identified characteristics associated with immediate (>or= 1 h) and hospital survival, with P <or= 0.01 considered statistically significant. RESULTS: Cardiac arrest occurred in 223 of 518,294 anesthetics (4.3 per 10,000) during the study period. Frequency of arrest for patients receiving general anesthesia decreased over time (7.8 per 10,000 during 1990-1992; 3.2 per 10,000 during 1998-2000). The frequency of arrest during regional anesthesia (1.5 per 10,000) and monitored anesthesia care (0.7 per 10,000) remained consistent. Immediate survival after arrest was 46.6%, and hospital survival was 34.5%. Twenty-four patients (0.5 per 10,000) had cardiac arrest related primarily to anesthesia. From multivariate analysis, patients who experienced arrest due to bleeding were less likely to survive hospitalization (P = 0.001). Survival was also lower for patients who experienced arrest during nonstandard working hours (P = 0.006) and for patients who had protracted hypotension before arrest (P < 0.001). CONCLUSIONS: The overall frequency of arrest for patients receiving anesthesia decreased during the study period. Most arrests were not due to anesthesia-related causes, and most patients experiencing anesthesia-related arrest survived to hospital discharge. Although many factors determining survival may not be amenable to modification, the fact that arrests during nonregular working hours had worse outcomes may indicate that the availability of human resources influences survival.

Adolescent↗