The survival of Escherichia coli in nitrogen atmospheres under changing conditions of relative humidity.
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Aerosols↗
Biomedical subjects
C S Cox
Publications and source records attributed to C S Cox.
Quantitative image analysis of skeletal muscle from newborn pigs with myofibrillar hypoplasia and splayleg.
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Animals↗
Free radical activity and loss of plasma antioxidants, vitamin E, and sulfhydryl groups in patients with burns: the 1993 Moyer Award.
This study examines the relationship of burn injury and plasma levels of conjugated dienes, total sulfhydryl groups, and vitamin E in patients with thermal injuries. Plasma neopterin levels were determined as an index of macrophage activity and serine elastase as an index of polymorphonuclear cell activation. Thirteen patients with burns, six survivors and seven nonsurvivors, were studied for the first 4 days, then every other day until postburn day 14. Twelve healthy volunteers served as the control group. Survivors had 56% +/- 4% total body surface area burned, and nonsurvivors had 63.9% +/- % total body surface area burned. The patients with burns, compared with the control group, showed elevated plasma levels of the lipid peroxidation products conjugated dienes (0.767 +/- 0.045 vs 0.269 +/- 0.013 Abs at 233 nm) and reduced levels of the natural scavengers of free radicals, vitamin E (196.2 +/- 12.6 vs 841.1 +/- 22.7 micrograms/dl) and total sulfhydryl groups (54.0 +/- 0.4 vs 15.8 +/- 1.0 mumol/dl). The total sulfhydryl groups/conjugated dienes ratio fell at a greater rate (9.8% +/- 3.2% vs 3.2% +/- 0.7%/day) in nonsurvivors than in survivors (p < 0.05 by Mann-Whitney). The levels of elastase were slightly elevated in the patients with burns, but there was no difference between survivors and nonsurvivors. Normal neopterin levels are 3 to 10 nm/L; peak levels were 119 +/- 48 nm/L in nonsurvivors and 37.4 +/- 10 nm/L in survivors. Patients with burns demonstrated evidence of increased oxygen free radical activity and activation of polymorphonuclear cell and macrophages. Nonsurvivors demonstrated increased consumption of antioxidants compared with survivors.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
ECMO in the management of cardiac failure.
Extracorporeal membrane oxygenation (ECMO) can provide univentricular or biventricular cardiac, as well as respiratory, support; it has extended the application of ECMO to infants and children who develop refractory cardiogenic shock before or after repair of congenital heart defects. The Pediatric Cardiac ECMO Registry, recently established by the Extracorporeal Life Support Organization, reports an overall survival rate of 47%. All were believed to have little chance of survival without mechanical support. ECMO has also been used for perioperative cardiac support after cardiac transplant. Hemorrhage remains the most common complication of ECMO. The future of ECMO for cardiac support depends on development of methods to prevent cardiac failure, improved ECMO techniques, and increased pediatric cardiac transplantation.
Cardiac Output, Low↗
Use of an intravascular oxygenator/carbon dioxide removal device in an ovine smoke inhalation injury model.
The intravascular oxygenator/carbon dioxide removal device (IVOX) is a hollow fiber, implantable membrane oxygenator that lies in the vena cavae and is designed to augment gas exchange during acute respiratory failure. An ovine model of smoke inhalation injury (lethal dose for 50% of animals at 48 hr) was used in eight ewes to test the safety and efficacy of this device. The IVOX was placed in the vena cavae through a right internal jugular vein cut-down. A vacuum pump withdrew O2 through the hollow fiber membrane, and IVOX gas flow was measured with a flow meter. Outlet gas was analyzed for CO2 concentration. Changes in O2 exchange were calculated as changes in mixed venous O2 content with the IVOX on compared with the IVOX off, multiplied by the cardiac output. The IVOX did not significantly change cardiac output, mean arterial pressure, pulmonary artery pressure, or hemoglobin concentration measured every 6 hr for 48 hr. The maximum CO2 exchange averaged 40.2 +/- 10.5 ml CO2/min. The average change in oxygen exchange was 98.4 +/- 76.0 ml O2/min. Iliac vein injury from attempted IVOX placement without fluoroscopic guidance resulted in one death. The authors concluded that the IVOX was safe when properly inserted and provided approximately 25-30% of the gas exchange requirements in this model.
Animals↗
10 years after NHANES I: report of initial followup, 1982-84.
The NHANES I Epidemiologic Followup Study (NHEFS) was jointly initiated by the National Center for Health Statistics and the National Institute on Aging in collaboration with other National Institutes of Health and Public Health Service agencies. The goal of NHEFS is to examine the relationship of baseline clinical, nutritional, and behavioral factors assessed in the first National Health and Nutrition Examination Survey (NHANES I-1971-75) to subsequent morbidity and mortality. Data collection for the initial phase of followup took place between 1982 and 1984 and included tracing of all NHANES I participants, determining their vital status, conducting in-depth interviews with surviving participants or with proxies for those who were deceased or incapacitated, conducting selected physical measurements, obtaining facility records for stays in hospitals or nursing homes that occurred during the period of followup, and obtaining death certificates for decedents. Ninety-three percent of the original cohort was successfully traced. Interviews were conducted for 93 percent of traced, surviving participants and 84 percent of traced, surviving participants and 84 percent of traced, deceased subjects. Physical measurements were obtained for approximately 95 percent of surviving, interviewed subjects. Death certificates are available for more than 95 percent of the decedents, and 18,136 facility records were received for 6,477 subjects.
Adolescent↗
10 years after NHANES I: mortality experience at initial followup, 1982-84.
The NHANES I Epidemiologic Followup Study (NHEFS) was initiated jointly by the National Center for Health Statistics and the National Institute on Aging in collaboration with other National Institutes of Health and Public Health Service agencies. The goal of NHEFS is to examine the relationship of baseline clinical, nutritional, and behavioral factors assessed in the first National Health and Nutrition Examination Survey (NHANES I-1971-75) to subsequent morbidity and mortality. Tracing for the initial followup began in 1981 and ended in 1984. This article compares the mortality experience of the NHEFS cohort with survival probabilities and cause-of-death distributions derived from U.S. vital statistics data. The analysis was done for 28 age-race-sex specific subgroups. The survival of each group of the NHEFS cohort corresponds quite closely to that expected on the basis of the U.S. life table survival probabilities. Mortality differentials by age, race, and sex are also quite similar between NHEFS and U.S. vital statistics. In addition, the cause-of-death distributions among NHEFS participants are quite similar to those expected based on national vital statistics. Thus, there do not seem to be any serious biases in the mortality data. The NHEFS, therefore, provides a unique resource for assessing the effects of baseline sociodemographic, health, and nutritional factors on future mortality in a large, heterogeneous sample that is representative of the nation's population.
Actuarial Analysis↗
Intracorporeal CO2 removal and permissive hypercapnia to reduce airway pressure in acute respiratory failure. The theoretical basis for permissive hypercapnia with IVOX.
Initial studies have shown that the intravascular oxygenator and carbon dioxide removal device (IVOX, Cardiopulmonics, Inc., Salt Lake City, UT) removes approximately 30% of VCO2. After noting increased CO2 removal with increased venous CO2, we developed a conceptual analytical model based on data obtained from patients and laboratory experiments. Increasing the CO2 gradient across the hollow fiber membranes of IVOX increases the operating efficiency of the device. Using the patient management technique of permissive hypercapnia (limiting tidal volumes, respiratory rates, and airway pressures) serves to increase the CO2 gradient across the membrane. The conceptual analytical model predicts that a PaCO2 of 75-80 mm Hg is required to obtain a CO2 gradient that results in IVOX CO2 removal of approximately 90-100 ml CO2/min. This technique may allow a broader application of both permissive hypercapnia and IVOX in acute respiratory failure.
Acute Disease↗
Poisoning mortality, 1985-1995.
Poisoning was reported as the underlying cause of death for 18,549 people in the United States in 1995 and was ranked as the third leading cause of injury mortality, following deaths from motor vehicle traffic injuries and firearm injuries. Poisoning was the leading cause of injury death for people ages 35 to 44 years. Poisoning death rates were higher in 1995 than in any previous year since at least 1979. From 1990 to 1995, the age-adjusted rate of death from poisoning increased 25%; all of the increase was associated with drugs. About three-fourths of poisoning deaths (77%) in 1995 were caused by drugs. The age-adjusted rate of drug-related poisoning deaths for males (7.2 per 100,000) in 1995 was more than twice that for females (3.0 per 100,000). From 1985 to 1995, poisoning death rates for males ages 35-54 years nearly doubled to 20.4 per 100,000, and the drug-related poisoning death rate for males ages 35-54 years nearly tripled, reaching 16.1 per 100,000. From 1990 to 1995, death rates associated with opiates and cocaine more than doubled among males ages 35-54 years. The numbers of opiate and cocaine poisoning deaths for 1995 more than doubled when all multiple cause of death codes were examined instead of only the underlying cause of death codes.
Adolescent↗