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PubMed2000

Increased abundance of terrestrial isopod populations in terrestrial ecosystems contaminated with petrochemical wastes.

Arthropods are integral components of the food chain, and because many reside in close association to the soil and its contaminants, their communities may be sensitive indicators of ecotoxicity. We examined the influence of petrochemical contaminants on the abundance of several taxonomic groups of macroarthropods, with an emphasis on isopods, residing on two reference sites and three petrochemical-contaminated sites at an abandoned oil refinery site in southwestern Oklahoma. Relative densities of surface-dwelling macroarthropod assemblages were significantly greater on contaminated sites than reference sites. Differences in terrestrial isopod populations were particularly remarkable and consistent across study sites, with densities approaching 180-fold greater on contaminated than reference sites. Similarity comparisons indicated that abundances and composition of macroarthropod assemblages sampled on the contaminated sites were more similar to one another than to the communities residing on reference sites. Although preliminary, these initial results support the hypothesis that macroarthropod assemblages, in particular isopods, are sensitive to soil contaminants and could be a valuable approach to evaluating the effects of petrochemical contamination of soils on terrestrial ecosystems.

Animals↗
PubMed1999

Allelic diversity at the Mhc-DQA locus in cotton rats (Sigmodon hispidus) and a comparison of DQA sequences within the family muridae (Mammalia: Rodentia).

The cotton rat (Sigmodon hispidus) is a common murid rodent of the southern United States, Mexico, and Central America. Using single-stranded conformation polymorphism analysis and DNA sequencing techniques, 11 DQA exon 2 alleles were detected among 180 S. hispidus from Caddo County, Oklahoma, USA. The alleles represent a single locus exhibiting a high level of polymorphism. Nucleotide and amino acid distance values among DQA alleles of S. hispidus were higher than those within Mus musculus and species of Rattus. Although the distribution of polymorphic amino acid residues among alleles of S. hispidus was similiar to that of Mus and Rattus, some residues of the alpha-helix region were more variable in S. hispidus. Comparisons of nonsynonymous and synonymous substitutions indicated a trend toward higher numbers of nonsynonymous substitutions; however, this difference was not significant statistically among S. hispidus alleles. To examine evolution of DQA alleles within Muridae, we performed a phylogenetic analysis that included DQA alleles from S. hispidus, Peromyscus leucopus, M. musculus, R. norvegicus, and six Australian species of Rattus. Results depicted monophyly for each genus, and this concordance between species and gene trees represents a lack of evidence for trans-species persistence of alleles among these genera.

Alleles↗
PubMed2003

The contribution of C3 and C4 plants to the carbon cycle of a tallgrass prairie: an isotopic approach.

The photosynthetic pathway composition (C(3):C(4) mixture) of an ecosystem is an important controller of carbon exchanges and surface energy flux partitioning, and therefore represents a fundamental ecophysiological distinction. To assess photosynthetic mixtures at a tallgrass prairie pasture in Oklahoma, we collected nighttime above-canopy air samples along concentration and isotopic gradients throughout the 1999 and 2000 growing seasons. We analyzed these samples for their CO(2) concentration and carbon isotopic composition and calculated C(3):C(4) proportions with a two-source mixing model. In 1999, the C(4) percentage increased from 38% in spring (late April) to 86% in early fall (mid-September). The C(4) percentages inferred from ecosystem respiration measurements in 2000 indicate a smaller shift, from 67% in spring (early May) to 77% in mid-summer (late July). We also sampled daytime CO(2 )concentration and carbon isotope gradients above the canopy to determine ecosystem discrimination against (13)CO(2) during net uptake. These discrimination values were always lower than corresponding nighttime ecosystem respiration isotopic signatures would suggest. After accounting for the isotopic disequilibria between respiration and photosynthesis resulting from seasonal variations in the C(3):C(4) mixture, we estimated canopy photosynthetic discrimination. The C(4) percentage calculated from this approach agrees with the percentage determined from nighttime respiration for sampling periods in both growing seasons. Isotopic imbalances between photosynthesis and respiration are likely to be common in mixed C(3):C(4 )ecosystems and must be considered when using daytime isotopic measurements to constrain ecosystem physiology. Given the global extent of such ecosystems, isotopic imbalances likely contribute to global variations in the carbon isotopic composition of atmospheric CO(2).

Carbon Isotopes↗
PubMed2005

Surgeons' economic profiles: can we get the "right" answers?

Hospitals and payers use economic profiling to evaluate physician and surgeon performance. However, there is significant variation in the data sources and analytic methods that are used. We used information from a hospital's cardiac surgery and cost accounting information systems to create surgeon economic profiles. Three scenarios were examined: (1) surgeon modeled as fixed effect with no patient-mix adjustment; (2) surgeon modeled as fixed effect with patient-mix adjustment; (3) and surgeon modeled as random effect with patient-mix adjustment. We included 574 patients undergoing coronary artery bypass surgery at Baptist Medical Center, Oklahoma City, OK between July 1, 1995 and April 30, 1996. We found that profiles reporting unadjusted average surgeon costs may incorrectly identify high- and low-cost outliers. Adjusting for patient-mix differences and treating surgeons as random effects was the preferred approach. These results demonstrate the need for hospitals to reexamine their economic profiling methods.

Aged↗
PubMed2003

Children's response to terrorism: a critical review of the literature.

The advent of major terrorist assaults has ushered in a sense of insecurity and vulnerability heretofore unknown in the US. There is information about the impact of disasters and trauma on children, but relatively little data on the effects of terrorism. The events of September 11, 2001 have underscored the need to examine this issue. This report summarizes recent studies that address the impact of terrorist incidents on children, and examines issues related to mental health services for children in the post-attack environment. Work related to the 1993 bombing of the World Trade Center, the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City, the 1998 bombing of the American Embassy in Nairobi, Kenya, and the September 11 attacks are reviewed. This article indicates significant challenges in the identification, evaluation, and treatment of children potentially in need of attention.

Child↗
PubMed1980

Arrhythmias in sleep apnea.

A 23-year-old black female was referred to the University Hospital of Oklahoma because of "sleep trouble." She complained of falling asleep easily during the daytime. A sleep study was performed which showed prolonged apnea, up to 35 seconds, and prolonged asystole, up to seven seconds, with second-degree heart block. A tracheostomy was performed. She had lost some weight and did well until six months later, when she developed severe throbbing headache with visual blurring. She came to the emergency room and an ECG showed sinus bradycardia with prolonged sinus pauses, up to 2.6 seconds, and first- and second-degree AV block. She had no hypoxia and atropine was ineffective. Electrophysiologic studies were performed. Details of the case are described and mechanisms of the arrhythmias are discussed.

Adult↗
PubMed1977

The asymptomatic bruit.

A review of 144 carotid endarterectomies performed in 108 patients at the Oklahoma Health Science Center over the past six years showed an acceptable operative morbidity and mortality in group of patients with an asymptomatic midcervical bruit who underwent prophylactic carotid endarterectomy prior to anticipated elective surgery. Long-term follow-up showed these patients to be free of neurologic symptoms of fatalities in 100 per cent of long-term survivors and suggests that carefully selected patients with an asymptomatic bruit may undergo carotid endarterectomy to prevent future neurologic complication.

Aged↗
PubMed1985

Is duodenal ulcer perforation best treated with vagotomy and pyloroplasty?

From 1967 to 1980, 65 patients underwent vagotomy and pyloroplasty for treatment of an acute perforated duodenal ulcer at the University of Oklahoma Health Sciences Center. Their age ranged from 15 to 82 years, with a mean age of 49.6 years. All vagotomies were truncal and pyloroplasties were of the Heineke-Mikulicz variety. The condition of each patient was classified as acute or chronic depending on the duration of symptoms before perforation. The postoperative complication rate and perioperative mortality were higher in the group of patients whose symptoms had been present less than 3 months before perforation. Patients who underwent vagotomy and pyloroplasty more than 24 hours after the onset of symptoms had a higher mortality compared with those who were operated on less than 24 hours from the onset of symptoms. We mainly attributed the perioperative death rate of 11 percent to advanced patient age and associated cardiopulmonary disease. There was no significant difference in the rate of postoperative complications in patients over 60 years of age compared with those under 40 years; hence, age alone does not preclude definitive treatment, such as vagotomy and pyloroplasty. The degree of contamination found at operation did not correlate with a poor postoperative course. There was no significant increase in the mortality in the group with gross contamination. Of the patients available for long-term follow-up, 85 percent remained free of symptoms. These results compare favorably with reports for the elective treatment of duodenal ulcer with vagotomy and pyloroplasty. We conclude that vagotomy and pyloroplasty is acceptable, safe, and ideal for patients with acute perforated duodenal ulcers, except when significant cardiopulmonary disease exists or when the duration of perforation is more than 24 hours.

Acute Disease↗
PubMed1986

Is the treatment for thyroglossal duct cysts too extensive?

From 1970 to 1985, 64 patients underwent surgical management for thyroglossal duct cysts at the University of Oklahoma Health Sciences Center. Their ages ranged from 1 to 63 years with a mean of 12.4 years. Ninety-one percent of the patients were available for follow-up. All patients underwent one of three forms of treatment: the classic Sistrunk operation, a modified Sistrunk operation, or excision of the cyst only. Eleven percent had undergone a previous procedure. The majority of patients were found to have a cyst in the midline at the level of the hyoid bone. Eighty-eight percent of the patients underwent excision of the midportion of the hyoid bone. There were no postoperative deaths and the perioperative complication rate was 20 percent, the majority being wound-related. All recurrences took place within 4 months of operation. Factors that appeared to be associated with an increased risk of complications and recurrence included young patient age (less than 10 years), rupture of the cyst at the time of operation, infection, and failure to excise the midportion of the hyoid bone and the suprahyoid tract. One patient was found to have a mixed papillary and follicular carcinoma in the thyroglossal duct. We support the original premise of Sistrunk that "the cure of thyroglossal cyst are unsuccessful unless the epithelium-lined tract, running from the cyst to the foramen cecum is completely removed," including the hyoid bone.

Adolescent↗
PubMedDate not supplied

Studies on the distribution of lipids within fibrous plaques.

The present report is an attempt to determine the nature of the circulation of lipids within fibrous plaques by studying the pattern of lipid distribution within the plaques. The material was obtained from aortas from 405 mammals and birds dying in the Oklahoma City Zoo. Analysis of the pattern of lipid distribution in 187 lipid containing aortic fibrous plaques suggested that most of the lipids entered the plaques at the shoulders and circulated from there toward the centers, usually in the outermost layers of the plaques.

Animals↗
PubMed1984

Radiation-enhanced resistance to oxygen: a possible relationship to radiation-enhanced longevity.

Shortly after gamma-irradiation, flour beetles (Oklahoma strain of Tribolium confusum) exhibited a decline in resistance to oxygen toxicity. Beginning about two weeks after irradiation, however, the LD50 exposure time in pure oxygen was much greater than that of nonirradiated beetles, and this enhanced resistance persisted for about 6 months. The magnitude of the enhancement was a function of dose, and decreased with increasing age at irradiation. These characteristics of a radiation-enhanced resistance to a stress are comparable to the characteristics of radiation-enhanced longevity in Tribolium, in that after irradiation mortality rate is less than that of controls for about 6 months, the magnitude of the effect is dose-dependent, and older beetles are refractory to the effect. Irradiation under anoxic conditions reduced the development of oxygen resistance to the same degree that it reduced acute radiation lethality, suggesting that the amount of biological damage is the critical factor. These results are discussed in terms of the "induced repair" theory of radiation-enhanced longevity of insects.

Aging↗
PubMed1982

Lung cancer excess in an abandoned lead-zinc mining and smelting area.

Analysis of cancer mortality in whites has revealed a significant excess in both males and females in an old lead/zinc mining and smelting area. This area consists of three rural contiguous counties: Cherokee County, Kansas, Jasper County, Missouri, and Ottawa County, Oklahoma. The lung cancer excess has persisted for at least 28 years for males and 5 years for females. A pilot case/control study is underway in Cherokee County to assess the influence of cigarette smoking, occupation, and residence on the lung cancer excess. Analysis will incorporate the histologic findings. From an environmental perspective, there are numerous mine tailings containing lead, zinc, cadmium, sulfur, germanium, and other chemicals. Considerable dust is airborne. Numerous openings (sink holes and bore holes) connect the old mines with the surface. Radium 226 has been detected in the untreated groundwater.

Carcinogens, Environmental↗
PubMed1991

Primary immune responses of selected small mammal species to heterologous erythrocytes.

1. We surveyed the primary humoral immune responsiveness of six small mammal species (Peromyscus leucopus, Microtus pinetorum, Perognathus hispidus, Neotoma floridana, Onychomys leucogaster, Mus musculus) collected from wild populations in central Oklahoma using sheep red blood cells (SRBC) as the immunogen and a splenic plaque-forming cell (PFC) assay. 2. Individuals within each wild species examined produced antibodies to a single intraperitoneal injection of SRBC, however, considerable interspecific and intraspecific variation in responsiveness was indicated. 3. Overall, primary immune responsiveness varied from 0 to 5013 PFC/10(6) cells. Spleen weights, total splenic nucleated cell yields, PFC/spleen, PFC/mg spleen, and PFC/10(6) cells were significantly different among species. 4. Mean cell yield in M. pinetorum was greater than in P. leucopus and CD-1 laboratory mice (included as positive controls). Number of PFC/10(6) cells was greater in CD-1 laboratory mice than P. hispidus and P. leucopus. The coefficient of variation for PFC/10(6) cells in CD-1 laboratory mice was 38% compared to 109, 129, and 56% for M. pinetorum, P. hispidus, and P. leucopus, respectively. 5. Interspecific and intraspecific differences among wild species may be a reflection of disparate life histories and other environmental selection pressures.

Animals↗
PubMedDate not supplied

Predicting alcohol use among young adults.

Factors influencing alcohol use among young people were studied using a questionnaire administered in Oklahoma and Wisconsin to 257 single males and 358 single females between the ages of 17-24. Predictors were broken down into the sets of demographics, family, religion, peer behavioral standards, approval of deviance, value of love and pleasure, and sex role variables. It was hypothesized that the predictors for alcohol use in males would differ from that of females. Data were analyzed separately for both male and female subjects. The multiple regression analysis found that the blocks of demographics, religion, peer behavioral standards, and approval of deviance were positive predictors for the use of alcohol in both males and females. The blocks, value of love and pleasure, and sex role variables were not found to be predictors of alcohol use in both males and females. Block number two (family) was found to be a predictor for females use of alcohol but not for males.

Adolescent↗
PubMed1987

Biochemical serogrouping of clinical isolates of Cryptococcus neoformans.

Three hundred twenty-three clinical isolates of Cryptococcus neoformans of diverse geographic origins were biochemically serogrouped using glycine-cycloheximide-phenol red agar (GCP), the same medium less cycloheximide (GOP), and glycine-L-canavanine bromothymol blue agar (CGB). Twenty isolates gave positive reactions on all three media typical of the B and C serotypes. Three were from the Peoples' Republic of China; three each were from Michigan (two patients) and Louisiana; two each were from California, Georgia, and Virginia; and one each was from Alabama, Florida, North Carolina, Oklahoma, and Tennessee. Two hundred seventy-six isolates were identified as belonging to the A/D serogroup; 272 were of American origin and four were from China. Twenty-seven isolates were biochemically ungroupable. Evaluations of the reactions on all three media were open to subjective interpretations. Utilization of glycine was the most frequent atypical variable; 36 of 276 (13%) A/D isolates utilized glycine while being inhibited by either GCP or CGB or both. Significant differences between A/D and B/C serogroups in terms of susceptibility to 5-fluorocytosine but not to amphotericin B were observed; B/C serogroup isolates appeared to be less susceptible to 5-fluorocytosine in vitro than were the A/D serogroup isolates. These results provided new evidence on the distribution of B/C serogroup isolates of C. neoformans in America and demonstrate the difficulties of using biochemical tests for serotyping purposes. They also offer a possible explanation for the apparent more refractory therapeutic responses of infections caused by B and C serotypes to conventional antifungal chemotherapy.

Amphotericin B↗
PubMed1988

False positive Legionella pneumophila direct immunofluorescent monoclonal antibody test caused by Bacillus cereus spores.

Direct immunofluorescent monoclonal antibody stain testing for Legionella pneumophila in Oklahoma lake water yielded an unknown bacillus with fluorescence intensity equal to that of L. pneumophila stock strains. The organism in question was identified as Bacillus cereus, a ubiquitous bacterium. When B. cereus cultures were studied, fluorescence was seen in spores but not in vegetative cells. Since a positive immunofluorescent monoclonal antibody test (alone) might be considered by some individuals as unequivocal to very good evidence for the presence of L. pneumophila, this finding emphasizes the importance of confirming positive stain results with cultures whenever possible.

Antibodies, Monoclonal↗
PubMed1994

Resuscitation of canine hemorrhagic hypotension with large-volume isotonic crystalloid: impact on lung water, venous admixture, and systemic arterial oxygen saturation.

The objective of this study was to test the hypothesis that after hemorrhagic hypotension, reinfusion of the shed blood with threefold that volume of lactated Ringer's (LR) solution will significantly increase lung water and venous admixture and hence decrease systemic arterial oxygen saturation. A prospective, randomized, fixed-volume hemorrhage laboratory study was performed at the Oklahoma University Health Sciences Center on 18 anesthetized mongrel dogs. After 40 mL/kg of blood were withdrawn through a femoral artery catheter, the dogs were randomized either to the control group (n = 9) that received a reinfusion of the shed blood, or to the LR treatment group (n = 9) that received an intravenous mixture of the shed blood with 120 mL/kg of LR. After fluid resuscitation, pulmonary artery occlusion pressure (PAOP) and cardiac output (CO) were significantly increased in the LR group compared with control animals (PAOP, 18.7 +/- 1.1 vs 13.4 +/- 2.9 mm Hg; CO, 8.14 +/- 1.08 vs 4.59 +/- 0.47 L/min; P < .05 each). However, lung water, venous admixture, and systemic arterial PO2 were similar between groups. In this fixed-volume hemorrhage model, hemodiluting the reinfused shed blood with threefold the volume of LR did not significantly influence lung water, venous admixture, or systemic arterial oxygen saturation.

Animals↗
PubMedDate not supplied

Benign extracerebral fluid collections: a cause of macrocrania in infancy.

In order to determine the frequency and natural history of benign extracerebral fluid collections, computed tomography reports from a period of 26 months at Oklahoma Children's Memorial Hospital were reviewed (total scans: 3,411). Bilateral frontal extracerebral fluid collections were found in 94 infants under 1 year of age. Eighty-two infants had computed tomography scans as part of the evaluation for macrocrania. Thirteen patients had the typical findings of benign extracerebral fluid collections but otherwise were completely asymptomatic. Longitudinal observation for up to 30 months failed to reveal any changes in neurologic status of these patients. Benign extracerebral fluid collections are a relatively common cause of macrocrania in infants. The presence of these fluid collections is not of immediate concern, providing that clinical evaluations fail to identify either neurologic or developmental abnormalities.

Cephalometry↗