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Biomedical subjects

R Stevens

Publications and source records attributed to R Stevens.

211 records · Page 12Linked to original sources
PubMedDate not supplied

A randomized study of ondansetron syrup in children: evaluation of taste acceptability and tolerance.

Ondansetron, a highly selective 5-HT3 receptor antagonist, is available in an intravenous (IV) formulation and tables, but syrup would be particularly useful in children. As chemotherapy can affect taste perceptions, this study was undertaken to determine the preference between two flavors of ondansetron syrup in children undergoing chemotherapy. Fifty-nine children, randomized into a multicenter, double-blind, crossover study, each received 5 mg/m2 of IV ondansetron daily before chemotherapy. The syrup was then randomly given in two doses, one of each flavor, strawberry and grape, 30 minutes apart. The preference was assessed 30 minutes after the second dose of syrup had been administered. Taste was assessed by the child against a panel of five faces. Of those children expressing any preference, 70% preferred the strawberry flavor. Overall, 59% of children preferred the strawberry flavor, whilst 25% preferred grape (P = 0.005) and 15% expressed no preference. The only adverse event assessed as drug related by the investigator was constipation, which occurred in one patient. In conclusion, a strong preference was found for the strawberry formulation. The ondansetron syrup was safe and well tolerated.

Antiemetics↗
PubMedDate not supplied

Surveying public health nurses' continuing education needs: collaboration of practice and academia.

In the last twenty years, entry level requirements for public health nursing have shifted to less and less educational preparation. Many agencies hire registered nurses with associate degree or diploma preparation who have no experience. The shift in entry level requirements has challenged public health nursing administrators and educators to examine continuing education needs to meet knowledge deficits among public health nurses. The study reported here presents findings from a national survey of 56 state and territorial health departments. The results clarify the continuing education needs and issues related to the educational gaps of public health nurses of the 1990s.

Clinical Competence↗
PubMedDate not supplied

Neonatal alloimmune thrombocytopenia may be less severe in a subsequent pregnancy.

Neonatal alloimmune thrombocytopenia (NAIT) is more common than previously appreciated. Clinical presentation is varied, but it is generally a severe disorder and it is said to be more severe in subsequent pregnancies. The authors present a case of fatal disseminated intravascular coagulation that was diagnosed as NAIT only after presentation of a subsequent surviving sibling with intracranial hemorrhage and thrombocytopenia. Despite the perinatal complications, this second sibling had good neurodevelopmental outcome. This is the first reported case of less severe disease occurring in a subsequent pregnancy.

Adult↗
PubMedDate not supplied

Deliberate epidural air injection in dogs: a radiographic study.

To investigate whether and to what extent air bubbles are present in the epidural space after injections of air, the authors designed an experiment using a chronic dog model. The epidural space was entered at the sixth or seventh lumbar interspace in six mongrel dogs (weight, 20 to 27 kg). Loss-of-resistance (LOR) to saline was tested to identify the epidural space. Three milliliters of air were injected via a Tuohy needle, followed by 5 ml of contrast material (Isovue 300, Squibb Diagnostics). Anterior-posterior (AP) and lateral radiographs were taken on day 1. On days 2, 4, and 8, the procedure was repeated, omitting the air injection. Radiographs were read by a neuroradiologist. Air bubbles were radiographically demonstrated in all six dogs on day 1, and in three of six dogs on day 2. No air was seen on later films. The air bubbles seen were small and few in number but often located near intervertebral spaces. The authors' findings suggest that injection of large volumes of epidural air should be avoided, particularly when N2O is used as part of the anesthetic or when performing diagnostic peridurography since N2O may expand the volume of existing bubbles and interfere with filling of the epidural space by local anesthetics or contrast material.

Air↗
PubMedDate not supplied

Synthetic amphipathic sequences of surfactant protein-B mimic several physicochemical and in vivo properties of native pulmonary surfactant proteins.

A mixture of lipids and proteins unique to the lung lines the airspaces of all mammalian species. This mixture, termed pulmonary surfactant, is essential for normal lung function. We have synthesized selected amino acid sequences of one of the major low molecular weight surfactant proteins to find whether these peptides can duplicate effects of native protein. Peptide/lipid mixtures approximate results found with native surfactant proteins both in vitro and in vivo. Effects found with native proteins or synthetic peptides include association with, and ordering of, surfactant lipid; changes in surface tension with surface compression; rapid adsorption of lipids from subphase to surface; and improvements in oxygenation of surfactant-deficient rats.

Amino Acid Sequence↗
PubMedDate not supplied

HIV seroprevalence in newborns in New York State.

The prevalence of human immunodeficiency virus (HIV) infection was determined in women at the time of childbirth throughout New York State between November 30, 1987, and November 30, 1988. Mandatory blood specimens (276,609) obtained from all newborns were examined for HIV. The overall HIV seroprevalence rate was 0.66% (1816 newborns), with 0.16% in Upstate New York and 1.25% in New York City. Rates for newborns whose mothers were aged 20 to 29 years (1.30%) and 30 to 39 years (1.35%) were significantly higher than rates for those with mothers younger than 20 years of age (0.72%). Rates of seropositivity were higher among blacks (1.8%) and Hispanics (1.3%) than among whites (0.13%). Seropositivity of HIV was higher in zip code areas with high rates of drug use (2.2%) than in the rest of New York City (0.8%). It is estimated that more than 726 HIV-infected children were born in New York State during the 1-year study period, using 40% as the probable proportion of seropositives that will become infected.

Adult↗
PubMedDate not supplied

Developing an advanced radiographer curriculum at the baccalaureate level.

Curriculum design for the baccalaureate degree in radiologic technology has been the subject of discussion for many years. Several investigators have identified the need for such a curriculum in radiologic technology; however, a definitive official statement has yet to surface concerning the purpose of the degree. A conceptual model for the baccalaureate curriculum in radiologic technology is presented as well as the process used to develop such a curriculum.

Curriculum↗
PubMedDate not supplied

Incorporating general education competencies in the radiography curriculum.

Due to the absence of general education (ie, arts and sciences) competencies in radiography accreditation standards, individual programs vary with regard to the amount and type of general education offered. Throughout the last 15 years, renowned educators have repeatedly suggested that, amongst other things, career mobility for the radiographer could be improved as a result of introducing general education into the curriculum. A method for incorporating general education competencies in the radiography curriculum through revision of the accreditation standards is presented.

Curriculum↗
PubMedDate not supplied

Effect of cimetidine, probenecid, and ketoconazole on the distribution, biliary secretion, and metabolism of [3H]taxol in the Sprague-Dawley rat.

Male Sprague-Dawley rats had their bile ducts cannulated and were dosed with [3H]taxol (2 mg/kg, 68-77 microCi/mg) as a continuous intravenous infusion for 6 hr so that the plasma concentrations, tissue distribution, metabolism, and biliary secretion of taxol could be studied. Defining potential drug-drug interactions of taxol with cimetidine (90 mg/kg), probenecid (360 mg/kg), and ketoconazole (50 mg/kg) was motivated by frequent concomitant clinical use or the potential to reduce clearance of taxol so that lower doses could be used. At 6 hr, rats were killed. Samples of blood (plasma), lung, spleen, liver, kidney, heart, skeletal muscle, brain, testes, and fat were obtained. Taxol and metabolites were measured by total radioactivity counting and HPLC separation using on-line radioactivity detection. Concentrations of taxol in plasma increased to 0.19 microM in the control rats and did not reach steady-state by 6 hr. Lung, spleen, liver, and kidneys had the greatest tissue taxol concentrations [4.7-5.7 nmol/g (microM)] and were > 25-fold higher than the simultaneous 6-hr plasma taxol concentration. Taxol concentrations in brain and testes were negligible, 0.06 and 0.07 nmol/g, respectively. Radioactive metabolites were not found in plasma or most tissues. Only liver had appreciable concentrations of taxol and metabolites; however, > 80% of hepatic radioactivity was parent taxol. Through 6 hr of collection, 24% of the dose was secreted in the bile approximately 38% of which was as parent taxol. Cimetidine had no effect on the distribution, metabolism, or elimination of [3H]taxol. Probenecid did not effect tissue distribution or plasma concentrations of taxol.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Inhalation of nitrous oxide expands epidural air bubbles.

BACKGROUND AND OBJECTIVES: Epidural air bubbles are known to persist for more than 24 hours after injection. Nitrous oxide may cause expansion of these bubbles. METHODS: Nine dogs were anesthetized. Ten mL air and 9 mL of iophendylate were injected into the lumbar epidural space. Control animals (n = 3) breathed halothane in 100% oxygen. Experimental animals (n = 6) breathed halothane in 70/30 nitrous oxide/oxygen. Lateral radiographs were taken before and just after injection, and again 3 hours after breathing either 70% nitrous oxide or 100% oxygen. Epidural space pressure was monitored and recorded during these 3 hours. RESULTS: In all experimental animals, an increase in bubble size was observed. In the control animals, bubble size either remained the same or decreased. Epidural space pressure did not change in any animal. CONCLUSIONS: Inhalation of nitrous oxide results in expansion of epidural air bubbles. This may cause displacement of epidural local anesthetics it large volumes of air are present in the epidural space.

Anesthesia, Epidural↗
PubMedDate not supplied

Pharmacokinetics and pharmacodynamics of subcutaneous interleukin-2 in HIV-infected patients.

STUDY OBJECTIVES: To assess the pharmacokinetics and pharmacodynamics of subcutaneously administered interleukin-2 (IL-2) in patients infected with the human immunodeficiency virus (HIV). DESIGN: Open, dose-escalating phase I clinical trial. SETTING: Government research hospital. PATIENTS: Eighteen patients infected with HIV. INTERVENTIONS: Recombinant IL-2 at dosages of 12, 15, or 18 MIU/day was administered subcutaneously once or twice/day for 5 consecutive days every 2 months. A total of 28 cycles of therapy were included in the analysis. MEASUREMENTS AND MAIN RESULTS: Concentrations of IL-2 in serum were determined by a commercial enzyme-linked immunosorbent assay. Interleukin-2 was well absorbed, with peak concentrations from 21.9-112.9 IU/ml. Absorption was slow, with mean (+/- SD) time to maximum of 4.4 +/- 1.8 hours and a lag time of 26.9 +/- 13.7 minutes. Elimination half-life was 3.3 +/- 0.9 hours. The concentrations had wide variability both within and among patients. Levels of tumor necrosis factor-alpha were increased. Maximum body temperature and systemic side effects were associated with peak serum levels. CONCLUSION: Interleukin-2 is well absorbed after subcutaneous injection in HIV-infected patients, and that route of administration is an alternative to intravenous infusions.

Adult↗