Compatibility of Medical-Grade Polymers with Dense CO(2).

This study reports the effect of exposure to liquid carbon dioxide on the mechanical properties of selected medical polymers. The tensile strengths and moduli of fourteen polymers are reported. Materials were exposed to liquid CO(2), or CO(2) + trace amounts of aqueous H(2)O(2), at 6.5 MPa and ambient temperature. Carbon dioxide uptake, swelling, and distortion were observed for the more amorphous polymers while polymers with higher crystallinity showed little effect from CO(2) exposure. Changes in tensile strength were not statistically significant for most plastics, and most indicated good tolerance to liquid CO(2). These results are relevant to evaluating the potential of liquid CO(2)-based sterilization technology.

Vertical Flux of Biogenic Carbon in the Ocean: Is There Food Web Control?

Models of biogenic carbon (BC) flux assume that short herbivorous food chains lead to high export, whereas complex microbial or omnivorous food webs lead to recycling and low export, and that export of BC from the euphotic zone equals new production (NP). In the Gulf of St. Lawrence, particulate organic carbon fluxes were similar during the spring phytoplankton bloom, when herbivory dominated, and during nonbloom conditions, when microbial and omnivorous food webs dominated. In contrast, NP was 1.2 to 161 times greater during the bloom than after it. Thus, neither food web structure nor NP can predict the magnitude or patterns of BC export, particularly on time scales over which the ocean is in nonequilibrium conditions.

High tech home care: surviving and prospering in a changing environment.

Managed care plans are expanding rapidly into new marketplaces. Reimbursement for home infusion therapy, including parenteral and enteral nutrition, is significantly affected under managed care, especially when capitated payment mechanisms are used. Home care companies have experienced downsizing, mergers, acquisitions, and fierce competition in the managed care environment. Clinicians who are entering the home care setting may find that, in addition to clinical expertise, their marketability depends on a set of new skills and abilities in order to prosper in this new environment.

Strategies for improving corporate philanthropy toward health care providers.

The authors report the results of a survey examining corporate donation behavior relative to the health care industry. The findings suggest that, despite the poor economic conditions of recent years, companies have continued to make substantial contributions--particularly to the health care industry--and that the single most identifiable factor influencing the availability of funds in any given year was the company's expected earnings in that year. Additionally, the authors suggest criteria that influence whether a company donates to a particular organization as well as the expected benefits and methods of recognizing donations. Finally, they discuss preferred solicitation methods along with marketing implications for the health care industry.

Current status of home infusion therapy.

The growth of home infusion therapy has been influenced by external forces that have changed the access to and use of health care. As home infusion therapy expands into other alternate care settings, clinicians, regardless of discipline, must be cognizant of how daily clinical practice is affected by regulations, changes in legislation, and consumerism.

Experience with home aerosolized pentamidine treatment in patients with AIDS.

Pneumocystis carinii pneumonia (PCP is the most frequent opportunistic infection in patients with AIDS and is the most common cause of death in these patients. Conventional parenteral trimethoprim/sulfamethoxazole or parenteral pentamidine treatment is often not completed because of frequent incidence of adverse reactions. Aerosolized pentamidine appears to be better tolerated and is considered an alternative treatment for PCP in both hospital and community settings. This report describes our experience with 34 patients with AIDS who received aerosolized pentamidine at home. All patients were over 18 years old and had received either parenteral or aerosolized pentamidine within a medically supervised setting before home treatment was initiated. The Respigard II nebulizer system powered by an oxygen source was used as the delivery system. All patients took two puffs of metaproterenol sulfate 10 minutes prior to two 15-minute sessions of pentamidine inhalation. No relapse or adverse reactions were observed in patients. Large randomized clinical trials currently are underway to compare the value of aerosolized pentamidine with other forms of treatment for PCP.

Clinical evaluation of elastomeric hydrogel peripheral catheters during home infusion therapy.

The use of elastomeric hydrogel (Aquavene, Menlo Care, Menlo Park, Calif.) peripheral catheters in home infusion therapy was prospectively evaluated. Elastomeric hydrogel catheter composition differs from that of conventional peripheral catheters made of Teflon or silicone in that it softens upon insertion and expands two gauge sizes within 30 minutes of insertion. Fifty-four test catheters were successfully placed in 44 home infusion therapy patients, for a total dwell time of 290 days. Average dwell time was 5.37 days, with a range of 1 to 20 days. The extension of dwell time beyond the accepted standard of 72 hours was not associated with an increased incidence of phlebitis when compared to the incidence of phlebitis reported in the scientific literature. The ability to extend peripheral catheter dwell time without increasing the incidence of catheter-related complications may have major clinical and economic advantages for the payors, providers, and consumers of home infusion therapy.

Initiation of a home hemotherapy program using a primary nursing model.

A home hemotherapy pilot study was implemented based on a primary nursing model. Seventy-one patients received a total of 248 units of red blood cells and 104 units of platelets during 137 home transfusions. In no case did a clinical change in patient status require the interruption of the transfusion. Total nursing time for the pretransfusion, transfusion, and posttransfusion follow-up visits for each patient averaged 4.36 hours, while another 4.45 hours accounted for nurse travel to and from the home and the blood bank. Home hemotherapy is a viable option for selected homebound patients. Program success is dependent on staff education, strict clinical guidelines, and an acknowledgment of the time required to provide quality patient care.

Gastrointestinal manifestations of the acquired immunodeficiency syndrome.

AIDS-related gastrointestinal disease is common, presenting a challenge to all nutritional support clinicians. Patients frequently suffer from weight loss, diarrhea, malabsorption, and cachexia. Many factors complicate the course of AIDS-related gastrointestinal disease, including decreased food intake (resulting from fatigue and malaise), increased metabolic demand and nutritional requirements, and identifiable gastrointestinal pathology. Gastrointestinal pathology is well-documented, and in approximately 50% of persons with AIDS-related gastrointestinal disease, a causative agent can be identified. In general, treatment of AIDS-related gastrointestinal disease is not always curative. Much of the chronic gastrointestinal dysfunction is caused by recurring opportunistic pathogens that are resistant to chemotherapy. Often, patient care and long-term management can focus only on fluid and electrolyte balance, nutritional support, and symptom control. Even clinically stable patients have been diagnosed as chronically malnourished and, for reasons that remain unclear, are prone to rapid nutritional deterioration during disease exacerbations. Published reports of nutritional assessment and intervention in persons with AIDS are now appearing in the literature. However, the eventual mortality associated with AIDS still results in a hesitancy on the part of many clinicians to prescribe aggressive nutritional support, especially parenteral nutrition. Who to treat and at what stage of illness becomes the question. As new agents, such as AZT, are prescribed on a more frequent basis for persons with AIDS, the use of nutritional support as adjunctive therapy early in the course of disease becomes an issue. Although improving nutrition has not been shown to reverse any of the cellular immunodeficiency caused by HIV infection, quality of life may be improved. In specific cases, nutritional support, whether through diet counseling, food programs, or intervention with enteral or parenteral nutrition, appears to improve strength and endurance, thus enhancing quality of life.

Effect of low extracellular calcium on gallbladder contraction in vitro.

Increases in intracellular calcium ion mediate smooth muscle contraction, but the requirement for extracellular calcium availability during this process is unclear. We studied the intact guinea pig gallbladder in an organ bath to define the effect of low bath calcium on contractile responses to varying doses of cholecystokinin-octapeptide, histamine, and acetylcholine. The contractile responses to cholecystokinin-octapeptide and acetylcholine were dependent on the presence of calcium in the bath, with a 40-100% reduction in contraction when buffer with no added calcium was used. In contrast, the contractile response to histamine was unchanged when stimulation was carried out in low calcium buffer. The contractions of the guinea pig gallbladder induced by cholecystokinin-octapeptide and acetylcholine, but not histamine, appear to require near-physiologic levels of extracellular calcium.

Diel interactions of oxygenic photosynthesis and n(2) fixation (acetylene reduction) in a marine microbial mat community.

Diel variations in N(2) fixation (acetylene reduction), CO(2) fixation, and oxygen concentrations were measured, on three separate occasions, in a marine microbial mat located on Shackleford Banks, North Carolina. Nitrogenase activity (NA) was found to be inversely correlated with CO(2) fixation and, in two of the three diel periods studied, was higher at night than during the day. Oxygen concentrations within the top 3 mm of the mat ranged from 0 to 400 muM on a diel cycle; anaerobic conditions generally persisted below 4 mm. NA in the mat was profoundly affected by naturally occurring oxygen concentrations. Experimentally elevated oxygen concentrations resulted in a significant depression of NA, whereas the addition of the Photosystem II inhibitor 3(3,4-dichlorophenyl)-1,1-dimethylurea decreased oxygen concentrations within the mat and resulted in a significant short-term enhancement of NA. Mat N(2)-fixing microorganisms include cyanobacteria and heterotrophic, photoautotrophic, and chemolithotrophic eubacteria. Measured (whole-mat) NA is probably due to a combination of the NA of each of these groups of organisms. The relative contributions of each group to whole-mat NA probably varied during diel and seasonal (successional) cycles. Reduced compounds derived from photosynthetic CO(2) fixation appeared to be an important source of energy for NA during the day, whereas heterotrophic or chemolithotrophic utilization of reduced compounds appeared to be an important source of energy for NA at night, under reduced ambient oxygen concentrations. Previous estimates of N(2) fixation calculated on the basis of daytime measurements may have seriously underestimated diel and seasonal nitrogen inputs in mat systems.

The antiarrhythmic effects of d-sotalol.

The antiarrhythmic properties of d-sotalol were studied in 38 patients undergoing electrophysiologic studies. Programmed electrical stimulation studies were performed in 28 men and in 10 women with a mean age of 67 years and a mean ejection fraction of 37 +/- 3%. All patients had inducible ventricular tachycardia while they were off all antiarrhythmic therapy. D-sotalol was given as a 2 mg/kg infusion over 15 minutes and did not significantly change the PR, QRS, or QTc intervals from baseline values in the group as a whole. In the group protected by d-sotalol, the percent change in the QTc interval as well as the percent change in refractoriness was significantly increased as compared to the group not protected. D-sotalol also significantly decreased heart rate. D-sotalol prevented the induction of ventricular tachycardia in 18 of the 38 patients, while significantly slowing the rate of the ventricular tachycardia in the group that could still have tachycardia provoked. Seventeen patients were tested on procainamide and only four were protected, while d-sotalol prevented the induction of ventricular tachycardia in 7 of these 17. Eleven patients were discharged on oral d-sotalol doses ranging from 100 to 400 mg twice daily. One patient died 1 month post discharge due to an acute myocardial infarction, and one patient had a cardiac arrest while on d-sotalol and survived and was switched to amiodarone therapy. The remaining nine patients are alive and well at 14 +/- 3 months. D-sotalol appears to be an effective antiarrhythmic drugs and appears to be well tolerated.

Nutrition education in schools of nursing in the United States. Part 2: The status of nutrition education in schools of nursing.

To explore whether nurses in academic institutions are being adequately educated to care for patients' nutritional needs, we conducted a survey of National League for Nursing accredited baccalaureate programs in the United States and their associated graduate programs. Data indicate that nutrition content is an integral part of baccalaureate nursing programs. Less emphasis is reported on nutrition content at the graduate level. Recommendations include revision of the substantive nutritive content and increased clinical experience in nutrition in both undergraduate and graduate nursing education.