Choosing a Private Practice: Q&A with Thomas A. Bensinger, MD, FACP.

The Focus on Fellows column will focus on how to get started in private practice. The columns may include a Q&A, articles written from a new practitioner's perspective, or advice from senior oncologists. The Q&A below is between a new practitioner and a more experienced one.

The in vivo survival of red blood cells stored in modified CPD with adenine: report of a multi-institutional cooperative effort.

In order to provide data in support of licensure applications for citrate-phosphate-dextrose (CPD) supplemented with adenine, a multi-institutional cooperative effort was organized to determine survivability of red blood cells subjected to prolonged liquid storage. Two manufacturers supplied plastic multiple bag blood storage containers prefilled with modified CPD (glucose 25% greater than the normal concentration) supplemented with adenine (17.0 to 17.

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.

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.

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).

Additional studies concerning the metabolism of packed erythrocytes in CPD adenine.

Studies concerning the relationship between glucose level, hematocrit to which cells were packed (within three hours of initial collection) and adenosine triphosphate (ATP) concentration were undertaken in CPD supplemented with adenine (0.25 mM final concentration). It was found that apparently adequate ATP levels could be maintained in 90 per cent hematocrit packed units at 42 days only if glucose was present in amounts 1.

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.

The effect of agitation on in vitro metabolism of erythrocytes stored in CPD-adenine.

Agitation of blood stored in plastic containers has been reported to lead to improved posttransfusion survival and it has been found that, in some media, agitation has improved erythrocyte 2,3-diphosphoglycerate (2,3-DPG) levels. Using CPD II media (CPD with 277.5 mM glucose and 2.

In vitro metabolism of packed erythrocytes stored in CPD-adenine.

In vitro metabolism of erythrocytes packed at 70 and 90 per cent hematocrits and stored in various CPD-adenine preservatives was studied. It was found that maintenance of acceptable levels of adenosine triphosphate (ATP) for the full 42 days of storage could be accomplished only if glucose levels were doubled from the standard 138.7 mM concentration to 277.

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.

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.