PubMed Health⌕ Search

Biomedical subjects

B Funk

Publications and source records attributed to B Funk.

28 records · Page 2Linked to original sources
PubMed1990

Xylan degradation by the thermophile Clostridium stercorarium: cloning and expression of xylanase, beta-D-xylosidase, and alpha-L-arabinofuranosidase genes in Escherichia coli.

Seven genes related to arabinoxylan degradation were isolated from a genomic library of the thermophilic bacterium Clostridium stercorarium. The cloned genes include a xylanase gene (xynA), two beta-D-xylosidase genes (bx1A and bx1B), two alpha-L-arabinofuranosidase genes (arfA and arfB), and two genes (celW and celX) encoding enzymes termed celloxylanases, which hydrolyze both xylans and beta-D-cellobiosides. The genes xynA, celX, and bxlB were found to encode the major xylanolytic enzyme activities induced by growth of C. stercorarium on xylan.

Cloning, Molecular↗
PubMed1989

Pharmacokinetics of midazolam in patients recovering from cardiac surgery.

The pharmacokinetics of midazolam has been studied in patients recovering from cardiac surgery, who required sedation for postoperative mechanical ventilation. Twelve males (mean age 64.5 years) with severe heart disease received an infusion of midazolam 15 mg.h-1 for 4 h, starting 1 to 3 h post surgery. Multiple blood samples were collected from each patient during the infusion and up to 48-93 h after it. The pharmacokinetic parameters of midazolam were determined using both moment analysis and the program NONMEM. The average terminal half-life was 10.6 h. The prolonged elimination was mainly due to a decrease in its metabolic clearance (0.25 l.min-1). The maintenance infusion dose of midazolam in such patients should be reduced. The time to recovery after stopping an infusion depends upon the amount of drug in the body at that time and a simulation of the plasma concentrations after various infusion regimens suggests that recovery will be delayed after prolonged (greater than 48 h) administration of midazolam to these patients. However, after shorter infusions (less than 12 h), redistribution of the drug away from the site of action was still occurring and recovery would be expected to be relatively rapid.

Aged↗
PubMed1988

Midazolam in plasma from hospitalized patients as measured by gas-liquid chromatography with electron-capture detection.

The present assay was developed for quantifying midazolam in plasma of patients hospitalized in intensive-care units or undergoing anesthesia and receiving many other drugs as well. Plasma samples are alkalinized with NaOH and midazolam is extracted into n-hexane. The organic phase is evaporated and reconstituted in n-butyl acetate, and the midazolam is quantified by gas-liquid chromatography with electron-capture detection. The calibration graph for midazolam was linear in the ranges 5-200 and 200-800 micrograms/L. The CVs for precision and reproducibility of the assay were less than 8%. The method was very specific for midazolam; most of the drugs commonly used in anesthesia and in the intensive-care unit did not interfere with the assay. The lowest detectable concentration was 1 microgram/L. The method is adaptable for use with an automated chromatographic system.

Aged↗
PubMed1986

A laboratory investigation of two new portable gas analysers.

Two new portable infrared gas analysers, the Irina (Drägerwerke, Lübeck, Germany) and the Normac (Datex Instrumentarium Corporation, Helsinki, Finland), were tested and the results compared to those from such established methods as gaschromatography and the Beckman LB-2 (Beckman, USA) infrared gas analyser using exactly defined gas mixtures from a vaporizer developed in our laboratory. The analysers were evaluated for their accuracy and precision, noise, zero stability, gain stability and the impact of flow, over-pressure, carrier gas and humidity. All three analysers showed good accuracy and precision. The noise level was acceptable except in the older version of the Normac, but this error has now been corrected by the manufacturer. Zero and gain stability are very good; gas flow and over-pressure do not affect the measurement. The influence of carrier gases and humidity is negligible except for the strong N2O effect on the Beckman. We conclude that this new generation of highly sophisticated and reliable but handy analysers will meet the clinical demands.

Anesthesia, Inhalation↗
PubMed1985

Determination of the partial pressure of halothane (or isoflurane) in blood.

A gas chromatographic method is described for the direct quantitative determination of the partial pressure of halothane (or isoflurane) in blood as well as the blood-gas partition coefficient. A head space technique and a flame ionization detector were used. Standard blood was obtained by equilibrating patients' blood with known gas concentrations in a tonometer. Using an infra-red analyser to measure the halothane gas concentration in the tonometer and within the anaesthetic system allowed for the direct comparison of the partial pressure in blood to the partial pressure in the inspired gas. Technical problems associated with this procedure, and with comparable methods, are discussed.

Chromatography, Gas↗
PubMed1975

Metabolic patterns in various structures of the rat nephron. The distribution of enzymes of carbohydrate metabolism.

By means of the microdissection technique applied on kidney tissue, the following results were obtained: Hexokinase, an enzyme of glycolysis, revealed a low activity in the proximal and a high activity in the distal tubule. This distribution pattern is consistent with the finding that glucose is the main fuel for the distal tubule. Glucose-6-phosphatase, an enzyme of gluconeogenesis, demonstrates a significant activity in the distal tubule and in the glomerulus. Both structures are, however, no glucose producers. Phosphoenolpyruvate carboxykinase, the key enzyme of gluconeogenesis, is found only in the segments of the proximal tubule. The distal tubule lacks any activity. This is also the case during starvation and metabolic acidosis when gluconeogenesis is stimulated. Glutamic dehydrogenase, -an enzyme possibly connected with ammoniagenesis-, malate- and lactate dehydrogenase-, enzymes involved with hydrogen transfer through the mitochondrial membrane-, showed a close parallelism to phosphoenolpyruvate carboxykinase in their distribution along the proximal tubule. The bidirectional function of glyceraldehyde-P dehydrogenase is well documented by the close correlation to phosphoenolpyruvate carboxykinase (gluconeogenesis) in the proximal tubule and to pyruvic kinase (glycolysis) in the distal tubule.

Ammonia↗
PubMedDate not supplied

[Effect of smoking and antioxidant vitamin concentrations of pregnant patients on birth weight of newborn infants].

An epidemiological study into the influence of cotinine validated maternal smoking and antioxidant vitamin concentrations on new born infants was carried out from 1992 to 1994 in the Department of Obstetrics and Gynaecology, University of Homburg/Saar. Of 222 participated pregnant women 26% were active smokers and 46% passive smokers. After adjustment a mean reduction in birth weight of 228 g was found in infants born to smokers, without dose correlation. Birth weight was not significantly reduced in infants born to passive smokers. There was no influence to the gestational age. A high correlation was established between maternal serum cotinine and umbilical cotinine (r = 0.91). In actively smoking mothers there was a positive correlation between vitamin E concentration and corrected infant birth weight (r = 0.33). Actively smoking mothers with children with a birthweight lower than the 25th percentile had significantly (p < 0.007) oftener lower vitamin E concentrations. Smoking increases the consumption of vitamin E, so that there is overproduction of peroxides and a reduction in prostacyclin. This lack of prostacyclin may lead to diminished perfusion of the placenta and may explain the birth weight reduction in smoker children.

Adult↗
PubMedDate not supplied

Quality of life in breast cancer.

PURPOSE: Currently, 1,721,700 women are living with breast cancer in the United States. As the number of survivors of breast cancer continues to rise, so must our knowledge about unique quality-of-life concerns. This article reports the results of a study on quality of life in women with breast cancer and validates the model of quality of life in this population. DESCRIPTION OF STUDY: To explore these concerns and to validate a breast cancer quality-of-life model, 21 survivors of breast cancer, across three age strata (younger than 40 years, 40 to 60 years, and older than 60 years), were interviewed and asked to complete quantitative surveys on pain and quality of life. RESULTS: Across all age groups, unique issues of survivorship include those related to physical, psychological, social, and spiritual well-being. In the domain of physical well-being, the areas of worst outcome were in menstrual changes and fertility, fatigue, and pain. In the domain of psychological well-being, predominant needs were in the areas of fear of the spread of cancer, distress from surgery, recurrence, fear of second cancer, impact on self-concept, and fear of future tests. The social well-being subscale identified the greatest disruption in the area of family distress. The spiritual well-being subscale showed greatest disruption in the area of uncertainty, although other aspects of this domain were usually rated in a positive direction (e.g., importance of religious activities). CLINICAL IMPLICATIONS: The data demonstrated the need for further research, assessment, and intervention across each of the quality-of-life domains. There is a significant need to address physical problems; however, the psychological domain demonstrated the greatest area of distress. The multidimensional needs of breast cancer survivors emphasize the need for multidisciplinary collaboration.

Adult↗