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J Pindyck

Publications and source records attributed to J Pindyck.

29 records · Page 2Linked to original sources
PubMed1980

Cost accounting in plateletpheresis: comparison of two techniques.

Cost comparison of two comparably effective techniques of plateletpheresis, a manual method and an automated discontinuous flow centrifugation technique, is presented using a hypothetical model. The former procedure costs $62.48 per pheresis for disposables and labour as opposed to $78.32 per pheresis for disposables and labour for the latter. The annual volume of plateletpheresis at which the accumulated costs equal the total charges, i.e. the 'break-even' point, is calculated and found to be 63.7 for the automated technique and 10.9 for the manual method, if the charge for each is $200.00. For the manual method at a current charge of $80.00, the break even point is 85.8. The assumptions underlying this hypothetical model are examined, and the effects of deviation from these assumptions are analyzed in terms of the break even point. Cost accounting of plateletpheresis is shown to be dependent upon the choice of approach to allocation of costs, the assumptions of the cost accounting model, and the selection of an appropriate charge.

Blood Transfusion↗
PubMed1978

Fibrinogen synthesis in serum-free hepatocyte cultures: stimulation by glucocorticoids.

Fibrinogen synthesis was investigated in cultures of chicken embryo hepatocytes initiated and maintained in chemically defined, serum-free medium. 11-Hydroxy glucocorticoids caused a 3-fold stimulation of fibrinogen synthesis. Half-maximal stimulation was achieved with 1 nM corticosterone or hydrocortisone, as compared with only 0.1 nM dexamethasone. Increased fibrinogen production in the presence of these glucocorticoids was characterized by a 4-hr delay in onset, a sensitivity to actinomycin D, and a requirement for the continuous presence of the steroid. Crossed immunoelectrophoresis permitted analysis of the simultaneous effects of glucocorticoids on the synthesis of more than 20 plasma proteins secreted in culture. The absence of an effect on the synthesis of most of these proteins was in sharp contrast to the 3-fold increase in fibrinogen production. Sera from a variety of animals also stimulated an increase in fibrinogen synthesis that was similar in degree but less specific than that due to glucocorticoids and that partially masked the response of the cells to the steroid hormones. The presence of an anticoagulant in the medium was found to be necessary for detection of the fibrinogen secreted in culture. Although insulin was routinely included in the chemically defined medium, the cells synthesized fibrinogen and responded to glucocorticoids in the absence of hormonal supplementation of the medium. These findings are consistent with the thesis that variations in glucocorticoid levels contribute to the regulation of fibrinogen production in the intact animal.

Animals↗
PubMedDate not supplied

Measures to decrease the risk of acquired immunodeficiency syndrome transmission by blood transfusion. Evidence of volunteer blood donor cooperation.

We studied whether volunteers giving blood to the Greater New York Blood Program (GNYBP) cooperated with procedures implementing public health recommendations intended to decrease the risk of acquired immunodeficiency syndrome (AIDS) transmission by blood transfusion. Predonation medical screening was expanded to exclude donors who might be ill with AIDS. To exclude possible asymptomatic carriers of the disease, members of groups at increased risk of AIDS were asked either not to give blood or to give it for laboratory studies. A confidential questionnaire, administered to all donors after medical screening, provided the vehicle for donors to advise the GNYBP whether their donation was for laboratory studies or for patient transfusion. We found that the number of male donors decreased; AIDS-related questions in medical history led to a 2 percent increase in donor rejections; 97 percent of donors said their blood could be used for transfusions; 1.4 percent said their blood could be used for laboratory studies only; and 1.6 percent did not respond. Only units designated for transfusion were released to hospitals. People who indicated that their donation was for laboratory studies had a higher prevalence of markers for hepatitis B virus and of antibodies to cytomegalovirus. White cell counts and helper/suppressor T lymphocyte ratios were not significantly different in the two groups. We conclude that volunteer donors have cooperated with the established procedures. None of the laboratory assays identified blood units donated by individuals who, based on information about AIDS high-risk groups, designated their donation for laboratory studies.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Human T-cell lymphotropic virus in volunteer blood donors.

Serum samples collected in 1985 and 1986 from 18,257 donors to the Greater New York Blood Program were screened by enzyme-linked immunoassay for antibody to human T-cell lymphotropic virus (anti-HTLV). Fifteen samples (0.08%) were confirmed positive: 7 by radioimmunoprecipitation assay (RIPA) alone, 6 by Western blot alone, and 2 by combined results from both tests. One donor, whose original test result was uninterpretable because multiple nonspecific bands were present on RIPA, clearly tested positive on subsequent specimens. Follow-up testing of individuals with this type of result may be needed to resolve their HTLV status. Anti-HTLV prevalence increased with age and was significantly more common in black or Hispanic donors and in those born in the Caribbean than in other donors. All anti-HTLV-positive donors were negative for antibody to HIV-1, and only one donor (7% of those positive) would have been excluded by any of the routine donor screening tests used at that time.

Blood↗
PubMedDate not supplied

Application of electroimmunoassay to the study of plasma protein synthesis in cultured hepatocytes.

Electroimmunoassay has been applied to the study of plasma protein synthesis and secretion in liver cell cultures. The assay is performed on unconcentrated samples of culture medium containing the secreted plasma proteins and yields results within 2 hours. The characteristics of plasma protein production by the cultured hepatocytes coupled with the sensitivity of this assay permit the study of plasma protein in synthesis and its regulation by hormones and other agents without the routine use of radioisotopes.

Animals↗