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Biomedical subjects

B E Rabinow

Publications and source records attributed to B E Rabinow.

7 recordsLinked to original sources
PubMed1994

Biomaterials with permanent hydrophilic surfaces and low protein adsorption properties.

Low protein adsorbing polymer films have been prepared with which to fabricate intravenous containers, designed for compatibility with low concentrations of protein drugs. The material is economically manufactured utilizing physical melt blending of water-soluble surface-modifying polymers (PEO, PEOX, PVA, and PNVP) with a base polymer (EVA, PP, PETG, PMMA, SB, and nylon). Permanency of the hydrophilic surfaces so generated was confirmed by surface contact angle experiments and total organic carbon leachables analysis of the aqueous contacting solutions. Binding of IgG, albumin and insulin was studied. A sixfold reduction of protein adsorption was obtained by adding 5% PVA13K to EVA, for IgG at a bulk concentration of 2.5 ppm. Surface bound protein measured by micro-BCA colorimetry, agreed with the solution protein lost, as determined by the Fluoraldehyde procedure. Imaging of the protein exposed plastic surfaces by silver enhanced protein conjugated gold staining agreed with the quantitative assay determinations.

Adsorption↗
PubMed1991

Characterization of cisplatin degradation as affected by pH and light.

The stability of cisplatin in 0.9% sodium chloride solution was studied. Cisplatin was reconstituted with sterile water for injection to achieve a concentration of approximately 1 mg/mL in 0.9% sodium chloride solution. The solutions were placed in flexible polyvinyl chloride containers, clear and amber glass flasks, and plastic syringes and stored at 22-25 degrees C in the dark or exposed to measured amounts of light and assayed periodically for up to 96 days. The initial pH of some of the solutions was adjusted. The stability of cisplatin in the solutions was determined by measuring the concentrations of cisplatin, trichloroammineplatinate(II) (TCAP), and trans-dichlorodiammineplatinum(II) (transplatin) with high-performance liquid chromatography and by measuring solution pH. The effect of adding ethylene oxide and other materials was also determined. TCAP was identified as the predominant degradation product of cisplatin in all the solutions. The rate of degradation was dependent on pH: In the dark, about 0.04% and 0.21% of the cisplatin degraded to TCAP per week at pH 4.3 and 6.3, respectively. The presence of ethylene oxide accelerated cisplatin degradation. Degradation also occurred during exposure to short-wavelength (350-490-nm) visible light. Storage in amber glass flasks offered more protection than storage in clear flasks. Isomerization of cisplatin to transplatin was not observed. The major degradation product of cisplatin was trichloroammineplatinate(II). Solution pH was the predominant factor affecting cisplatin stability.

Chromatography, High Pressure Liquid↗
PubMed1986

Sampling and analysis techniques for monitoring serum for trace elements.

We describe techniques for controlling contamination in the sampling and analysis of human serum for trace metals. The relatively simple procedures do not require clean-room conditions. The atomic absorption and atomic emission methods used have been applied in studying zinc, copper, chromium, manganese, molybdenum, selenium, and aluminum concentrations. Values obtained for a group of 16 normal subjects agree with the most reliable values reported in the literature, obtained by much more elaborate techniques. All of these metals can be measured in 3 to 4 mL of serum. The methods may prove especially useful in monitoring concentrations of essential trace elements in blood of patients being maintained on total parenteral nutrition.

Blood Specimen Collection↗
PubMed1977

Automated system for infrared spectrometric analysis for total CO2 of plasma contained in capillary tubes.

We describe how to assay plasma total CO2 automatically, discretely, and highly specifically by infrared absorption spectrometry. Plasma, 50 mul, is sampled in disposable capillaries and inserted into a block wherein the specimens are protected from exposure to air. A sequencer advances the block and signals a dispenser to flush the sample into a reaction vessel with 2.6 ml fo 50 mmol/liter H2SO4. After 24 s of incubation, the evolved CO2 is swept into a 1-meter infrared gas cell by a stream of nitrogen. A recorder displays the resulting peak in absorbance units. Operation of all valves controlling gas and liquid flow is regulated by the sequencer. In the present version, the time required for analysis of one sample is 65 s. The sample size may be reduced by at least 10-fold and the time sequence accelerated to assay 70-80 specimens per hour.

Autoanalysis↗
PubMed1976

Screening for erros in galactose metabolism with the erythrocyte.

We propose determination of the ratio of the rate of galactose metabolism to glucose metabolism by erythrocytes as a screening test for abnormalities in glucose and galactose metabolism. Packed erythrocytes (20 mul) are incubated for 1 h at 37 degrees C in 0.42 ml of a solution comprising phosphate buffer (pH 7.4), 0.4 mg of glucose, 60 mg of methylene blue, and 50 nCi of either [1-14C]glucose or [1-14C]galactose. Metabolism is then stopped by injecting dilute H2SO4 through a rubber septum sealing the flasks. On incubating the acidified solution for 1 h, the evolved CO2 is trapped in a well containing ethanolamine, which is suspended from the septum. The radioactivity of the well and its contents is measured in a scintillator, and from these data CO2 is calculated. (The scintillation medium is preheated with ethanolamine to eliminate chemiluminescence.) For normal adults mean values for CO2 are 0.468 mumol/liter of erythrocytes per minute for galactose and 37.8 mumol/liter of erythrocytes per minute for glucose. Homozygous galactosemics exhibit no galactose metabolism but the rate for flucose metabolism is normal. Results for parents of homozymotes are described. We review various causes for galactosemia and point out that transfer of galactose through the cell wall and into the erythrocyte is markedly reduced in certain cats and, although unreported, may possibly be a cause for galactosemia in humans.

Adult↗
PubMedDate not supplied

Aluminum in parenteral products: analysis, reduction, and implications for pediatric TPN.

Performance and cost of the best available analytical methodology for the measurement of aluminum in parenteral products are presented. Typical levels of aluminum in representative solutions are summarized. A methodical approach to the minimization of aluminum contamination in the manufacturing process is considered in light of aqueous aluminum chemical considerations. Results of long-term clinical follow-up studies of infants maintained on currently manufactured TPN solutions indicate no adverse pathology arising from aluminum.

Adolescent↗