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Biomedical subjects

S Foster

Publications and source records attributed to S Foster.

At least 91 records · Page 5Linked to original sources
PubMed1987

Prevention of Haemophilus influenzae type b infections in high-risk infants treated with bacterial polysaccharide immune globulin.

Apache Indian infants have a high frequency of Haemophilus influenzae type b (Hib) and pneumococcal infections. Forty percent of Hib infections in these infants occur before the age of six months, when active immunization may not be protective. To evaluate the efficacy of passive immunization with a human hyperimmune globulin (bacterial polysaccharide immune globulin [BPIG]) prepared from the plasma of immunized adult donors, we randomly assigned 703 infants in a double-blind fashion to receive 0.5 ml of BPIG per kilogram of body weight (n = 353) or 0.5 ml of saline (n = 350) intramuscularly at 2, 6, and 10 months of age. Hib-antibody levels were significantly higher in BPIG recipients than in placebo recipients at 4, 6, and 10 months of age (P less than 0.001). During the first 90 days after BPIG or placebo injection, no Hib or pneumococcal infections were detected in the BPIG group, whereas seven Hib infections (six cases of bacteremia and one of meningitis) and four pneumococcal infections (bacteremia) were detected in the placebo group (P = 0.007 and 0.06, respectively). During the fourth month, one case of Hib meningitis and two cases of pneumococcal bacteremia developed in the BPIG group, whereas there were no Hib or pneumococcal infections in the placebo group. We conclude that BPIG given at four-month intervals provided significant protection against serious Hib disease for three months, and that in high-risk infants it might be used alone, perhaps at three-month intervals, or together with active immunization.

Antibodies, Bacterial↗
PubMed1987

Lipoxygenase and cyclooxygenase blockade by BW 755C enhances pulmonary hypoxic vasoconstriction.

Lipoxygenase products (leukotrienes) have been proposed as the mediators of pulmonary hypoxic vasoconstriction. However, the supporting data are inconclusive because the lipoxygenase and leukotriene receptor blockers that reduce hypoxic vasoconstriction (such as diethylcarbamazine and the FPL's) have confounding effects. We investigated BW 755C, a potent inhibitor of both lipoxygenase and cyclooxygenase, in eight intact anesthetized dogs with acute left lower lobe atelectasis. We examined two manifestations of hypoxic vasoconstriction: shunt fraction, as an inverse indicator of regional constriction in response to local hypoxia, and the pulmonary pressor response to global alveolar hypoxia, as an index of general hypoxic vasoconstriction. During normoxia, shunt fraction, measured using a sulfur hexafluoride infusion, was 32.0 +/- 7.0%. The pulmonary pressor response to hypoxia, defined as the increase in pulmonary end-diastolic gradient produced by 10% O2 inhalation, averaged 4.5 +/- 1.8 mmHg. Then, during normoxia, BW 755C was administered. Shunt fraction fell in all eight dogs from the previous mean of 32% to 25.5 +/- 6.1% (t = 6.5, P less than 0.0005). The hypoxic pressor response rose in all dogs, from the previous 4.5 mmHg to 9.0 +/- 3.5 mmHg (t = 4.5, P less than 0.005). BW 755C enhances hypoxic vasoconstriction, an effect consistent with its activity as a cyclooxygenase inhibitor. These data do not support a substantive role for the lipoxygenase pathway in hypoxic vasoconstriction.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1987

Self-esteem in nurse anesthesia students: a national investigation.

The purpose of the study was to determine the self-esteem (SE) profile of nurse anesthesia students and identify education or biographic variables that influenced positive self-esteem. It was the assumption of the investigators that these variables, once described, could be used in curriculum planning and development to facilitate positive learning outcomes. A sample of 96 nurse anesthesia students, selected by random stratification, provided data by means of the Tennessee Self-concept Scale (TSCS) and an investigator-devised questionnaire. Correlation coefficients and analysis of variance were run on score subscales of the TSCS grouped according to nine education and biographic variables. Sample TSCS profiles were found comparable to control groups. Students reporting high grade point averages (GPAs) and married students demonstrated higher SE profiles than other groups. Gender, degree of physician mentorship, time in training, degree levels of generic nursing or anesthesia education, years of critical care experience, or anesthesia program base did not significantly influence SE measures.

Achievement↗
PubMed1987

The Monte Carlo simulation of the biological effect of the 10B(n, alpha)7Li reaction in cells and tissue and its implication for boron neutron capture therapy.

The energy deposition in the nucleus of cells exposed to the 10B(n, alpha)7Li neutron capture reaction has been calculated and compared to the measured biological effect of this reaction. It was found that a considerable distribution of hit sizes to the nucleus occurs. The comparison of hit size frequency with the observed survival indicates that not every hit, independent of its size, can lead to cell death. This implies the existence of a hit size effectiveness function. The analysis shows that the location of boron relative to the radiation-sensitive volume of the cell is of great importance and that average dose values alone are of limited use for predicting the biological effect of this reaction. Boron accumulating in the cell nucleus is much more efficient in cell killing than the same amount of boron uniformly distributed; its presence in one cell, however, has little effect on its neighboring cells in a tissue. When boron is present on the cell surface of a tissue (as presumably delivered by antibodies), its cell-killing effect is greatly reduced compared to that in uniform distribution. However, in this case much of the dose to one cell comes from neutron capture reactions occurring on the surface of its neighbor cells. These data have implications for the choice of boron carries in neutron capture therapy. The mathematical analysis carried out here is similar to that proposed recently for low-level exposure effects of radiation, taking mutation and/or carcinogenesis as biological effects. The results here show that high-level exposure to high-LET particles (resulting in cell killing) should be treated in an analogous manner.

Animals↗
PubMed1986

Glycine-based oral rehydration solution: reassessment of safety and efficacy.

We evaluated the safety and efficacy of a glycine-based orally administered rehydration solution by comparing it with a standard oral rehydration solution (ORS) without glycine in a randomized double-blind trial in United States infants (age less than 15 months) given treatment for acute gastroenteritis as inpatients or outpatients. The response to therapy (stool volume and duration of illness) was similar in the two groups, except that in four (13%) of 31 hospitalized infants receiving glycine-ORS hypernatremia developed, (one had symptoms) compared with none of 35 receiving ORS (P less than 0.04). Among the 77 outpatients there were no differences between the groups. This study demonstrates that glycine-ORS did not provide any therapeutic advantage over standard ORS, and hypernatremia developed in some patients receiving glycine-ORS. We suggest that caution be used with this type of solution until further safety studies have been done.

Anti-Bacterial Agents↗
PubMed1985

Bone turnover in early rheumatoid arthritis. 1. Biochemical and kinetic indexes.

Biochemical, hormonal, and kinetic indexes of bone turnover were measured in 17 ambulant female patients with rheumatoid arthritis (RA) of recent onset (mean disease duration 14.2 months) and 19 controls. Mean serum osteocalcin concentration and 85Sr accretion rates were reduced and mean urinary hydroxyproline-creatinine ratios were increased in RA, but these differences were not significant compared with control values. Mean total body potassium (TBK), an index of skeletal muscle mass, was significantly reduced in RA, and the ratio of observed to predicted TBK correlated with indexes of bone formation. No abnormality of skeletal metabolism could be shown in early RA, but reduced rates of bone formation associated with diminished muscle mass may influence the development of osteopenia later in the disease.

Adult↗
PubMed1985

Bone turnover in early rheumatoid arthritis. 2. Longitudinal bone density studies.

Serial measurements of bone mineral in 17 ambulant female patients with rheumatoid arthritis (RA) of recent onset and 19 age matched female controls were made in the radius by computed tomography and in the vertebrae by dual photon absorptiometry. Loss of trabecular bone from the distal radius was more rapid in RA (p = 0.0014), but there was no difference in the rate of loss of bone mineral from the radial midshaft or lumbar spine compared with the controls. This study is consistent with the hypothesis that the predominant form of bone loss early in the disease is the vicinity of affected joints.

Arthritis, Rheumatoid↗
PubMed1985

Calcium absorption in rheumatoid arthritis.

Calcium absorption, assessed by a double isotope method, was found to be impaired in postmenopausal women with rheumatoid arthritis of recent onset (mean 14.2 months) compared with controls. Circulating levels of 1,25-dihydroxyvitamin D (calcitriol) were higher than in controls, suggesting a primary malabsorption of calcium in these patients. The reduction in calcium absorption correlated with several measures of disease activity, suggesting that the disease process was responsible for the intestinal defect, but an effect from non-steroidal anti-inflammatory agents cannot be excluded. A primary reduction in calcium absorption may increase the risk of osteoporosis in women with rheumatoid arthritis.

Adult↗
PubMed1985

Oral rehydration therapy for acute diarrhea in ambulatory children in the United States: a double-blind comparison of four different solutions.

Oral rehydration solutions containing 50 to 90 mmol/L of sodium have recently been recommended for the treatment of diarrhea in both hospitalized and ambulatory children in the United States. Few data are available, however, from ambulatory US children. Therefore, we conducted a randomized double-blind study comparing the use of four different oral rehydration solutions with differing concentrations of sodium, glucose, and base. Ambulatory children less than 2 years of age with acute diarrhea (N = 140) were randomly chosen to receive solutions containing sodium at 90 (solution A), 50 (solution B), and 30 mmol/L (solutions C and D). All oral rehydration solutions contained 20 g/L of glucose except solution D which contained 50 g/L of glucose. Solution A contained bicarbonate as its base source whereas the other three contained citrate. All but three (98%) children were treated uneventfully according to the study protocol, and there were no differences among groups in measurements of clinical outcome. It was concluded that in ambulatory US children, oral rehydration solutions containing 90, 50, or 30 mmol/L of sodium can be used safely for the treatment of mild acute diarrhea and that citrate is as efficacious as bicarbonate in the correction of acidosis.

Ambulatory Care↗
PubMed1985

Role of soy-based, lactose-free formula during treatment of acute diarrhea.

A controlled study was conducted comparing the standard method of treating hospitalized infants with acute diarrhea (limited starvation) with the initiation of "early feeding" using a soy-based, lactose-free formula in infants of an American Indian tribe 12 months of age or younger. Forty-three patients, randomly assigned to group A, were given a soy-based, lactose-free formula four hours after hospitalization, and 44 patients, randomly assigned to group B, received standard therapy (food was withheld for the first 48 hours of hospitalization). After the first 48 hours, the same soy-based, lactose-free formula was given to the group B patients. Fluid intake and output of stool, urine, and vomitus were measured until the diarrhea resolved. Overall, group A patients showed less mean stool output (121 +/- 129 (SD) mL/kg) than group B patients (299 +/- 319 mL/kg) (P less than .001). Furthermore, the duration of illness was significantly shorter in group A patients (54 +/- 28 hours v 93 +/- 56 hours) (P less than .001). It was concluded that soy-based, lactose-free formulas can be safely used during the acute phase of diarrheal illness in infants and that their use shortens the duration of illness and decreases stool output in comparison with standard therapy.

Combined Modality Therapy↗
PubMed1984

A microprocessor-based system for measurement of gas exchange.

The basic physical measurements for determining gas exchange are difficult to make accurately even in a well-equipped, human-performance laboratory with experienced personnel. A fully automated system has been developed to achieve the accuracy of standard laboratory measurements. The application of this instrument extends from critical care to stress-testing. Real-time, multitasking software integrates the data collected from several transducers and analyzers and calculates up to several dozen physiological variables, which are range-checked for reasonableness. The operator is provided with user-friendly means to tailor the data-reporting and- collection functions of the system to his own needs and requirements. Because the instrument is controlled by software, the functions of calibration, measurement, timing, reporting, plotting, and data quality assurance are highly cost-effective. Extensive use of formal test procedures permits verifying all systems and data reliability; it also assures meeting the desired specifications. The ease of operation and high-quality results inherent in this system make it unsurpassed in gas-exchange measurements.

Computers↗
PubMed1984

Outpatient use of oral rehydration solutions in Apache population: effect of instructions on preparation and contamination.

Oral Rehydration Solutions (ORS) containing 90 and 50 mmol/L sodium have recently been recommended for use in ambulatory children in the U.S. These solutions are now marketed in powder form by some commercial companies. However, few data are available in the U.S. on the accuracy with which the solutions are mixed at home or on the bacterial contamination that may occur during mixing. We evaluated the effect of various forms of instructions on the occurrence of bacterial contamination and accuracy of mixing ORS at home by mothers of patients who were dispensed the dry ingredients of an ORS containing 90 mmol/L sodium at the U.S. Public Health Service Hospital, Whiteriver, Arizona. Patients were randomized to one of the four following groups: group I (23 patients) was given written instructions for mixing the solution along with a pre-marked container; group II (22 patients) was given written instructions only; group III (22 patients) was given a premarked container only; and group IV (19 patients) was given neither. All patients were given oral instructions in the preparation of ORS and were asked to refrigerate the reconstituted ORS. We collected samples of ORS at the patient's home 1 day after the clinic visit, to measure their electrolyte content and to identify any bacterial contamination. Mean Na+ concentrations were significantly lower in the ORS prepared by mothers/guardians in groups that were not given a premarked container [82 +/- 13 (II) and 79 +/- 21 (IV) mmol/L vs. 88 +/- 13 (I) and 92 +/- 14 (III) mmol/L; p less than 0.01].(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1983

Ultrastructure of sensory receptors on the labium of the rice brown planthopper.

The ultrastructure of the sensory receptors located on the labium of the rice brown planthopper is described; possible functions of individual receptors are suggested on morphological grounds. Uniporous chemosensilla which may or may not possess a mechanoreceptive dendrite, domed multiporous chemosensilla, and mechanoreceptive pegs are present on the flattened labial tip. Mechanoreceptive pegs are distributed over the labium. The fine structure of a multilobed sensillum located on either side of the labium is also described.

Animals↗
PubMed1983

Sensory receptors associated with the stylets and cibarium of the rice brown planthopper, Nilapavarta lugens.

The stylets of Nilapavarta lugens consist of two maxillae that interlock to form separate food and salivary ducts partially surrounded by two mandibles. The ultrastructure of the sensory innervation of the stylets is described. Each maxilla possesses five neurones which extend to the tip of the stylet. The mandibles also contain five neurones, four of which are paired. The paired neurones comprise a shorter dendrite extending part of the way along the stylet and a longer one extending to the tip. The possible functions of these neurones are discussed. Gustatory receptors are located in the small passageway leading from the food duct to the cibarium. The receptors are in two distinct groups on the epipharyngeal side and one group on the hypopharyngeal side of the food canal. Two to five neurones innervate each receptor which connects to the food canal via a small pore.

Animals↗