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At least 955 records · Page 53Linked to original sources
PubMed1995

Prophylaxis with enteral antibiotics in ventilated patients: selective decontamination or selective cross-infection?

Selective decontamination of the digestive tract (SDD) has been evaluated as a method to prevent colonization and infection in ventilated patients in 40 trials. On the basis of an assumption that cross-infection would be reduced as a consequence of SDD and that this would distort the results of SDD studies that used concurrent controls, 14 studies used historic controls. To test this assumption, three observations from the two types of studies were compared. (i) The differences between observed and expected event rates for each study were used to perform a meta-analysis. This revealed that the summary odds ratios for bacteremia and respiratory infection were marked by significant heterogeneity (P > 0.95) and inconsistencies between those derived from studies with concurrent versus studies with historic controls. (ii) Where the data were available, the rates of acquisition of colonization in control groups were higher in studies with concurrent controls than in studies with historic controls. (iii) At least four studies with concurrent controls have shown a pattern of pathogenic isolates consistent with cross-infection between groups. These results are contrary to the initial assumption and suggest the possibility that SDD represents a major cross-infection hazard.

Anti-Bacterial Agents↗
PubMed1989

Selective medium for Pseudomonas aeruginosa that uses 1,10-phenanthroline as the selective agent.

The MIC of 1,10-phenanthroline for 35 Pseudomonas aeruginosa strains was 128 micrograms/ml, whereas 32 micrograms or less per ml inhibited all other microorganisms tested. On the basis of these results, a selective agar for P. aeruginosa which contained 15 g of Trypticase soy broth (BBL Microbiology Systems), 15 g of agar, and 0.1 g of phenanthroline per liter was formulated. Forty-four P. aeruginosa strains yielded a mean efficiency of plating on this medium of 79% of the counts obtained on Trypticase soy agar, which was significantly higher than that obtained with pseudomonas isolation agar or Pseudosel agar. Pseudomonas cepacia, Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas stutzeri, representatives of 13 other genera (including gram-negative rods, gram-positive rods, and cocci), and a yeast were not recovered within 48 h at 35 degrees C when approximately 10(7) CFU were plated on this medium. Only small colonies from one strain each of P. fluorescens and P. putida could be seen at 3 and 7 days, respectively, and they had an efficiency of plating of only less than 0.001%. When 10(7) CFU of either of these strains was plated with 10(2) CFU of P. aeruginosa, it did not interfere with the quantitative recovery of P. aeruginosa.

Culture Media↗
PubMed1999

Comparison of selective broth medium plus neomycin-nalidixic acid agar and selective broth medium plus Columbia colistin-nalidixic acid agar for detection of group B streptococcal colonization in women.

The combination of neomycin-nalidixic acid (NNA) agar and a selective broth medium (SBM) has recently been shown to improve the sensitivity of screening cultures for group B streptococcal (GBS) carriage in women. Because of the relatively high cost of NNA agar, a study was initiated to determine whether Columbia colistin-nalidixic acid (CNA) agar would be an equally sensitive, more economical alternative. A total of 580 cervical-vaginal and/or rectal specimens submitted for detection of GBS were included in the study. Each was plated onto NNA and CNA agar and then inoculated into SBM. GBS were recovered from 95 of 580 (16.4%) specimens, including 61 isolates from CNA, 74 from NNA, 73 from the CNA-SMB combination, and 86 from the NNA-SMB tandem. Of those, 22 isolates were recovered on NNA but not CNA, 9 were cultured on CNA but not NNA, 52 were isolated on both media, and 12 were recovered from subcultures of SBM only. The overall sensitivity of CNA alone (64. 2%) was statistically significantly less than that of NNA agar (77. 9%), as was the sensitivity of combination of CNA plus SBM (76.8%) compared to that of NNA plus SBM (90.5%). Based on these findings, CNA should not be considered an acceptable alternative to NNA for the detection of GBS colonization in women despite potential cost savings.

Agar↗
PubMed1984

Beta-adrenoreceptor mechanisms in essential tremor: a comparative single dose study of the effect of a non-selective and a beta-2 selective adrenoreceptor antagonist.

In order to study the mode of action of beta-adrenoreceptor antagonists in essential tremor the efficacy of single oral doses of 2, 4 and 10 mg LI 32-468, a peripherally acting, selective beta-2 adrenoreceptor antagonist, was compared with a single oral dose of 120 mg propranolol in a randomised, double blind, placebo controlled trial. Both the lowest dose of LI and propranolol were shown to be equally superior to placebo in attenuating tremor magnitude. This finding supports the contention that the beneficial effect of beta-adrenoreceptor antagonists in essential tremor is mediated via peripheral beta-2 receptor mechanisms.

Adrenergic beta-Antagonists↗
PubMed1985

Surgery for epilepsy. Selective partial microsurgical callosotomy for intractable multiform seizures: criteria for clinical selection and results.

A series of 35 patients have been submitted to microsurgical callosotomy since February 1978, their age ranging from 6 to 42 years. The surgical procedure consisted either of a frontal parasagittal trephination or a larger frontoparietal rectangular craniotomy to allow the investigation of the surgical areas of the hemispheres with electrocorticography under local anesthesia. This allowed us to better follow the electrographic abnormalities and plan the extent of the callosal section suited to each case, in particular rostral and genual section, section of the trunk only or subtotal section sparing the splenium. In 2 cases, cortical resection was associated with the split. The callosal fibers which were divided by careful section under the resected portion provided a critical postoperative control of the extent of the lesion. Results and selection criteria will also be analyzed.

Adolescent↗
PubMed2007

Dimension selection for feature selection and dimension reduction with principal and independent component analysis.

This letter is concerned with the problem of selecting the best or most informative dimension for dimension reduction and feature extraction in high-dimensional data. The dimension of the data is reduced by principal component analysis; subsequent application of independent component analysis to the principal component scores determines the most nongaussian directions in the lower-dimensional space. A criterion for choosing the optimal dimension based on bias-adjusted skewness and kurtosis is proposed. This new dimension selector is applied to real data sets and compared to existing methods. Simulation studies for a range of densities show that the proposed method performs well and is more appropriate for nongaussian data than existing methods.

Algorithms↗
PubMed1977

Observations in man of hypoglycaemia during selective and non-selective beta-blockade.

The acute hypoglycaemic reaction is accompanied by a rise in systolic and a slight fall in diastolic blood pressure and a tachycardia. In contrast, during beta-blockade with propranolol there is a rise of both systolic and diastolic blood pressures and bradycardia. Restoration of blood glucose to normal is delayed. With metoprolol there is a lesser increase in diastolic blood pressure and a slight tachycardia. Restoration of the blood glucose to normal is little delayed. When patients liable to hypoglycaemia require a beta-blocking agent, it is suggested that a selective blocker such as metoprolol should be used.

Acute Disease↗
PubMed2004

Stereodivergent synthesis of chiral 2-alkenylaziridines: palladium(0)-catalyzed 2,3-cis-selective aziridination and base-mediated 2,3-trans-selective aziridination.

Whereas treatment of the allylic mesylates of N-protected 2-alkyl-4-amino-(E)-2-alken-1-ols with sodium hydride in DMF yields exclusively the corresponding thermodynamically less stable 2,3-trans-2-alkenyl-3-alkylaziridines, exposure of the methyl carbonates of N-protected 2-alkyl-4-amino-(E)-2-alken-1-ols to a catalytic amount of Pd(PPh(3))(4) in THF or 1,4-dioxane affords predominantly the corresponding thermodynamically more stable 2,3-cis-2-alkenyl-3-alkylaziridines. The kinetically favored trans-selective aziridination would be attributed to the allylic 1,3-strain in aza-anionic intermediates. The conformational analysis of the sterically highly congested 2-alkenylaziridines thus obtained is also presented.

Aziridines↗
PubMed1987

Comparison of vasodilator effects of DN-9693, a selective inhibitor of cyclic AMP phosphodiesterase, and isobutylmethylxanthine, a non-selective one, in dogs.

The present experiments were performed in anesthetized dogs in order to determine if DN-9693, a new antiplatelet agent known to selectively inhibit cyclic AMP phosphodiesterase (PDE), and isobutylmethylxanthine (IBMX), which inhibits both cyclic AMP and GMP PDEs, have different cardiovascular actions. With intra-arterial administration into the left anterior descending coronary, femoral, cranial mesenteric and renal arterial beds perfused at constant pressure with autologous blood, both agents increased blood flow in a similar dose range. DN-9693 was longer-acting than IBMX. Both agents were nearly equi-effective in the femoral circulation, but DN-9693 was 1.5-2 times less effective than IBMX in the others. With intravenous administration, both agents were equi-effective in increasing the maximum rate of rise of left ventricular pressure heart rate and myocardial oxygen consumption and in reducing mean blood pressure. However, DN-9693 was less effective in increasing coronary sinus outflow than IBMX. These results suggest the following: 1) Vasodilation in the somatic rather than the visceral circulation is important in reducing mean blood pressure. 2) Cyclic GMP may not be involved in the cardiac action of PDE-inhibitors. 3) Cyclic GMP may be involved in the vasodilator effect of PDE-inhibitors in the coronary, mesenteric and renal circulations but least involved in the femoral circulation.

1-Methyl-3-isobutylxanthine↗
PubMed1996

Selective growth of thermostable direct hemolysin-producing Vibrio parahaemolyticus in the alimentary tract of a gastropod, Clithon retropictus, at a selected estuary in Japan.

Thermostable direct hemolysin (TDH)-producing Vibrio parahaemolyticus increased in cell number in the alimentary tract of a gastropod. Clithon retropictus, from an undetectable level in July to 2.0 x 10(3)/g in September 1991 at the Sada estuary in the southern part of Japan. It was not detected in microalgae, foods of the gastropod, at the estuary or muddy sediments at a neighboring fishing port. The strain was not detected at two estuaries and two fishing ports ecologically separated from the Sada estuary. Serotypes of the isolated strains were different from those registered as clinical isolates. Our results confirm that TDH-producing V. parahaemolyticus grows selectively in the gastropod at some estuaries in Japan.

Animals↗
PubMed2000

Recommendations for measurement of and conventions for reporting sodium and potassium by ion-selective electrodes in undiluted serum, plasma or whole blood. International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). IFCC Scientific Division Working Group on Selective Electrodes.

Ion-selective electrodes (ISEs) respond to ion-activity and therefore do not sense substance concentration directly. However, it is recognized that sodium and potassium in plasma will continue to be expressed for clinical purposes in terms of substance concentration (mmol/l). A convention is proposed whereby for routine clinical purposes results of ISE measurements of sodium and potassium in undiluted plasma should be reported in terms of substance concentration (mmol/l). In specimens with normal concentrations of plasma water, total CO2, lipids, protein and pH, the values will concur with the total substance concentration as determined for example by flame atomic emission spectrometry (FAES) or ISE measurements on diluted samples. In specimens with abnormal concentrations of plasma water, the results will differ. However, under these circumstances, measurements of sodium and potassium by ISE in the undiluted sample will more appropriately reflect the activity of sodium and potassium and are therefore clinically more relevant than the determination in diluted samples. Detailed recommendations are made about practical procedures to achieve this. The recommended name for this quantity is the substance concentration of ionized sodium or ionized potassium in plasma, as opposed to total sodium or total potassium determined by, e.g. FAES, or ISE measurements on diluted samples.

Calibration↗
PubMed1975

[A gastro-electromyographical study on selective vagotomy and proximal selective vagotomy in the dog (author's transl)].

The gastro-electromyographical changes after vagotomy were studied by means of chronic in-situ experiments on eighteen dogs. Basic electric rhythms (slow spikes) were classified into normo-peristalsis and anti-peristalsis. The periodical rhythm of normo-peristalsis was partly disturbed after selective vagotomy but was more regular after feeding. Normally, rate changes of normo-peristalsis show typical patterns depending on the types of meals. These distinctive features were observed more clearly in S.V. and S.P.V. dogs. The incidence of normo-peristalsis and anti-peristalsis during fasting was high in normal dogs and low in S.V. dogs by night. A high level of anti-peristalsis occurred at the antrum in S.V. dogs. Thus, the numbers of normo-peristaltic waves reaching the antrum were decreased in S.V. dogs. After feeding, anti-peristalsis decreased in S.V. dogs but increased in normal dogs. Anti-peristalsis tended to occur in succession with a short cycle just like extra-systole. The author noted that sometimes anti-peristalsis was propagated towards both the orad and the pylorus simultaneously. In both S.V. and S.P.V. dogs, the denervated corpus seemed to have similar functions. On the other hand, in both the S.P.V. and normal dogs, the antrum seemed to function similarly.

Animals↗
PubMed1986

Selection of effective maximal expiratory parameters to differentiate asthmatic patients from healthy adults by discriminant analysis using all possible selection procedure.

Maximal expiratory volume-time and flow-volume (MEVT and MEFV) curves were drawn for young male nonsmoking healthy adults and for young male nonsmoking asthmatic patients. Eleven parameters, two MEVT (%FVC and FEV1.0%), six MEFV (PFR, V75, V50, V25, V10 and V50/V25), and three MTC parameters (MTC75-50, MTC50-25 and MTC25-RV) were used for the multivariate analysis. The multivariate analysis in this study consisted of correlation coefficient matrix computation, the test for mean values in the multivariates, and the linear discriminant analysis using the all possible selection procedure (APSP). Correlation coefficients among flow rate parameters and flow rate related parameters in high lung volumes were different between the two groups. In the eleven-parameter discriminant analysis by APSP using single parameters, PFR, V75 (flow rate at 75% of forced vital capacity), and FEV1.0% were considered to be the effective parameters. In the seven-parameter discriminant analysis using the parameter groups, the group of all parameters and the %FVC and flow rate-related parameter group were considered to be the effective numerical alternatives to MEFV curves discriminating between healthy adults and asthmatic patients.

Adult↗
PubMed2006

Correlations between perfectionism and coping strategies in response to researcher-selected vignettes or participant-selected events.

Participants, taking classes that met general learning requirements, were 133 men and 240 women from two private, Catholic, liberal arts college campuses. The sample consisted of 131 first-year students, 91 sophomores, 70 juniors, and 81 seniors. The sample was 95.2% Euro-American, consistent with the populations of these campuses, and 98.1% were between 18 and 22 years old. There were five different survey packets. One packet asked participants to report how they coped with a self-selected situation from their own past (Standard Condition). The other four packets asked participants how they would cope with one of four vignettes developed by the researchers. Two vignettes described common social situations, and two described common academic situations a college student would find stressful. The packets were randomly distributed among participants. Several significant correlations between perfectionism and coping strategies were found for the 4 vignettes, but none were found under the Standard Condition. Were there a self-serving bias in participants' reports of past situations in which they remember coping successfully, correlations would be diminished between coping and perfectionism in the Standard Condition.

Adaptation, Psychological↗
PubMed1995

Dietary fiber for cats: in vitro fermentation of selected fiber sources by cat fecal inoculum and in vivo utilization of diets containing selected fiber sources and their blends.

Two experiments were conducted to evaluate the addition of single sources and blends of dietary fibers to cat diets. In Exp. 1, fermentability of selected fibrous substrates by cat fecal microflora was evaluated. After 24 h of fermentation, OM disappearance (OMD) and total short-chain fatty acid (SCFA) production were greatest (P < .05) for citrus pectin, guar gum, and locust bean gum, whereas Solka Floc resulted in the least (P < .05) OMD and total SCFA production. In Exp. 2, six diets were formulated based on results of Exp. 1. The highest (P < .05) digestibilities of DM and OM occurred when cats consumed the diet with no supplemental fiber, and the lowest (P < .05) digestibilities occurred when cats consumed the SCFA blend (SC) diet. Nitrogen and lipid digestibilities also were lowest (P < .05) for cats consuming the SC diet, whereas total dietary fiber (TDF) digestibility (P < .05) was greatest for cats consuming the beet pulp, SC, and combination blend diets. Fecal consistency scores were highest (P < .05) for cats consuming the SC diet, indicating liquid, unformed stools. In conclusion, the in vitro fermentation technique was reasonably accurate in predicting in vivo digestion of fiber. The SC diet, which contained the most fermentable fibers, severely decreased nutrient digestibility and resulted in poor stool characteristics. Diets that contain moderately fermentable fiber provide fermentation end products that may be important in maintaining the health of the gastrointestinal tract of the cat.

Animal Feed↗
PubMed1985

Effect of selective and non-selective antimuscarinics on rectosigmoid motility and gastrointestinal transit.

In 12 healthy volunteers, a rectosigmoid motility index (RSMI) was measured when either placebo, 0.5 mg atropine, or 5 mg pirenzepine was given intravenously as a single dose, double-blind, in random order after a control period of 30 min. Compared with the control period, atropine gave a significant decrease of the RSMI during the entire recorded period of 90 min, whereas pirenzepine inhibited RSMI only during the first two 15-min periods. In another series of experiments, gastrointestinal transit was assessed by means of a radiographic marker method. In healthy volunteers, gastrointestinal transit was estimated (n = 20) and gastric secretion was measured (basally and after modified sham feeding; n = 10) during oral medication with placebo, 50 mg pirenzepine twice daily, or 17.5 mg benzilonium bromide twice daily. In 10 of the volunteers gastrointestinal transit was also estimated with 35 mg benzilonium bromide twice daily, and in the other 10 volunteers with 0.6 mg L-hyoscyamine twice daily. The number of retained markers was significantly lower during pirenzepine than during L-hyoscyamine treatment. Neither dose of benzilonium bromide changed the transit of markers. Compared with non-selective antimuscarinics, the effect of pirenzepine was differential: with equipotently acid-reducing doses the decrease of the RSMI after pirenzepine lasted shorter and gastrointestinal transit was accelerated.

Adult↗
PubMed2000

CD5 is A potential selecting ligand for B-cell surface immunoglobulin: a possible role in maintenance and selective expansion of normal and malignant B cells.

Although the function of CD5 on B cells is unknown, previous studies suggested that CD5 interaction with V(H) framework regions of surface immunoglobulins (Igs) may contribute to survival and expansion of B cells. Here we used B-chronic lymphocytic leukemia (B-CLL) cells and transformed B-cell lines from normal and B-CLL patients to study CD5-Ig interactions. Immobilized Ig binds and permits isolation of CD5 from lysates of CD5-expressing cell lines. Immunoglobulins or Fab fragments of different V(H) families varied in their effectiveness as inhibitors of anti-CD5 staining of CLL cells, appendix and tonsil tissue sections. Human Ig also binds to purified recombinant CD5. We show here for the first time that the unconventional Ig-CD5 interaction maps to the extracellular CD5-D2 domain whereas conventional epitopes recognized by anti-CD5 antibodies are localized in the D1 domain of CD5. We propose that interactions of VH framework regions with CD5 as a ligand may maintain, select or expand normal, autoimmune or transformed B cells and also contribute to skewing of the normal V(H) repertoire.

Antibodies, Monoclonal↗