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Biomedical subjects

T A Bensinger

Publications and source records attributed to T A Bensinger.

At least 19 recordsLinked to original sources
PubMed1977

Instability of the oxy form of sickle hemoglobin and of methemoglobin in isopropanol.

Oxygenated hemoglobin from water-lysed sickle erythrocytes preciptated more rapidly than hemoglobin from normal cells when exposed to 17% isopropanol in 0.1 M tris, pH 7.4, buffer (the isopropanol solubility test of Carrell and Kay). Precipitates became visible after approximately 20 minutes of incubation with SS, AS, or SC blood, while AC hemoglobin and normal adult A hemoglobin required 40-60 minutes of precipitate. Methemoglobin comprised less than 1.5% of the total hemoglobin present in all samples under study. Significant preciptation of methemoglobin did not occur unless methemoglobin levels were greater than 8%. Solubilization of the precipitate in 6M urea-barbital buffer and subsequent electrophoresis demonstrated that the insoluble material was sickle hemoglobin (Betas chain). The results of these experiments confirm previous findings indicating that even fully oxygenated sickle hemoglobin is unstable.

1-Propanol↗
PubMed1977

Prolonged maintenance of 2,3-DPG in liquid blood storage: use of an internal CO2 trap to stabilize pH.

A close relationship exists between the decrease in concentration of 2,3-diphosphoglycerate (2,3-DPG) and a fall in the pH of stored blood. Buffering the stored red cells with bicarbonate is one solution to the problem of maintaining pH during storage. The effectiveness of this buffer depends upon loss from the stored blood of carbonic acid in the form of CO2. We describe a system in which the CO2 is trapped in a small internal package which contains calcium hydroxide, or calcium hydroxide embedded in Silastic. A medium containing bicarbonate, adenine, glucose, phosphate and mannitol (BAGPM) is added after initial packing of the erythrocytes. With this approach, it has been possible to maintain 2,3-DPG at 92 percent of original, and ATP was approximately 62 percent of initial levels at the end of 42 days of storage if an internal Silastic bag containing calcium was used in bags agitated once weekly. More frequent agitation (five times weekly) produced acceptable maintenance of both 2,3-DPG (78 percent of original) and ATP (44 percent of original) after 42 days of storage when a Silastic block impregnated with calcium hydroxide was utilized to absorb CO2.

Adenosine Triphosphate↗
PubMed1977

Maintenance of low screen filtration pressure in blood stored in a new liquid medium: BAGPM.

Formation of microaggregates in blood stored in conventional media is reflected by rapidly rising screen filtration pressure (SFP). We show that the BAGPM (bicarbonate, adenine, glucose, phosphate, and mannitol) blood preservation system maintains SFP at near normal levels throughout the storage period of 42 days. Whenever the SFP had a tendency to rise in BAGPM blood, filtration through a routine in-line blood filter reverted SFP back to baseline levels. Blood from the same donors stored in citrate-phosphate-dextrose (CPD) adenine had a rapidly rising SFP by 7 to 14 days of storage. Filtration through the routine blood filter had no effect on the SFP of blood stored in CPD-adenine, CPD, or ACD. BAGPM not only maintains adequate levels of ATP and 2,3-diphosphoglyceric acid (2,3-DPG) during full 42 days of storage but also offers a unique system in which microparticulate material is prevented from forming, with maintenance of low SFP, perhaps because of its low leukocyte, platelet, and fibrinogen content.

Blood Preservation↗
PubMed1975

Redesigned apparatus for anaerobic measurement of blood pH at low temperatures.

A newly designed apparatus for anaerobic measurement of blood pH at low temperatures is presented. This apparatus features a larger glass electrode surface area, which is necessary to overcome the increased resistance of the glass as blood pH determinations at 0-15 C. are undertaken. Utilization of this equipment has confirmed the deltapH per degree C. of whole blood to be 0.0156, while intracellular pH of blood has a deltapH per degree C. of 0.0165.

Acid-Base Equilibrium↗
PubMed1975

Endogenous production of carbon monoxide as measured simultaneously in blood and gas phase.

Endogenous carbon monoxide (CO) production rates and total body haemoglobin content were determined simultaneously in blood and gas phase in 15 individuals. At 24% oxygen (O2) concentration in the closed rebreathing system, a correlation was obtained which revealed that a 1 mumole rise in CO in the gas phase of the system was the result of 48.94 +/- 5.3 (SE) mumoles of CO rise in the body. Three individuals had heat-damaged red cells reinjected intravenously to determine if the recovery rate of the subsequently produced CO was proportionate in both the gas phase and blood phase. Changes in blood CO concentration were not consistently detected by gas phase analysis. Prediction of CO production rates utilizing gas phase data alone did not reflect accurately CO production rates determined from blood carboxyhaemoglobin rises.

Carbon Monoxide↗
PubMed1975

Effect of blood in the gut on measurements of endogenous carbon monoxide production.

Changes induced in measurements of endogenous carbon monoxide (CO) production by blood in the lumen of the gut were studied in five normal volunteers. The study was undertaken because exogenous heme is absorbed by intestinal mucosal cells where the porphyrin ring is split with the release of CO that could contribute to blood CO levels and lead to a fallacious diagnosis of hemolytic disease. Volunteers who consumed 200 ml of their own blood doubled their endogenous production of CO (0.69 versus 0.34 mumoles/kg/hr). This suggested that at least 3% of the ingested heme was degraded and recovered as CO within 2 1/2 hr. Measurements of serum bilirubin also showed a significant increase after ingestion of blood. These data indicate that blood in the gastrointestinal tract can interfere with quantification of heme and bilirubin turnover from measurements of either endogenous CO production or bilirubin and suggest that this might occur with the ingestion of meat.

Blood Physiological Phenomena↗