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Biomedical subjects

J Nusbacher

Publications and source records attributed to J Nusbacher.

At least 19 recordsLinked to original sources
PubMed1992

Prevalence of antibody to human T-cell lymphotropic virus type I/II in people of Caribbean origin in Toronto.

OBJECTIVE: To estimate the prevalence of antibody to human T-cell lymphotropic virus type I/II (anti-HTLV-I/II) in people from an HTLV-I/II-endemic area (the Caribbean) living in a nonendemic region (Canada). DESIGN: Cross-sectional household survey. SETTING: Households in Toronto in 1989. PARTICIPANTS: A modified quota sampling method was used to recruit subjects of Caribbean origin as well as other Canadians. Of 2900 people invited to participate in the study 1323, 743 of Caribbean origin, were interviewed about their background and possible exposure to HTLV-I/II. MAIN OUTCOME MEASURES: Blood samples were analysed for anti-HTLV-I/II by means of an enzyme-linked immunoassay, the result being confirmed by the Western blot technique and radioimmunoprecipitation assay. The samples were also analysed for antibody to human immunodeficiency virus (anti-HIV) and hepatitis B surface antigen (HBsAg) and for surrogate markers of non-A, non-B hepatitis. RESULTS: A total of 853 blood samples (64.5%) were analysed, 483 (56.6%) from subjects of Caribbean origin. The proportion of subjects who agreed to give a blood sample was similar for the Caribbean and non-Caribbean strata. Eleven subjects, all of Caribbean origin (2.3% of the Caribbean stratum), were confirmed to be positive for anti-HTLV-I/II. There were no significant differences between the antibody-positive and antibody-negative subjects with respect to sex, age, racial origin or residence in the Caribbean for at least 22 years. All anti-HTLV-I/II-positive subjects were negative for anti-HIV and HBsAg, and four (36.4%) were positive for antibody to HBsAg and to hepatitis B core antigen. CONCLUSIONS: Except for origin, an association between antibody positivity and other factors could not be demonstrated. The findings suggest that blood donor screening might include place of origin in addition to the usual lifestyle or behavioural factors. However, the need to ensure safety of transfusion must be balanced against the need for participation of all groups in the blood transfusion program.

Adolescent↗
PubMed1989

Donor self-exclusion patterns and human immunodeficiency virus antibody test results over a twelve-month period.

Donor behavior in completing a pre-donation confidential self-exclusion form, which identified blood donors at high-risk of AIDS exposure, was evaluated. The form was completed by all donors during a 12 month period beginning in September, 1985. 188,824 units of blood were collected from 123,608 donors. On the first donation occasion 901 donors (0.73%) laboratory (LAB) designated, 224 (0.18%) did not complete the form correctly, and the remaining 122,483 transfusion (TRAN) designated. A greater proportion of LAB donors were men, under the age of 30 and had not donated in the previous two years than TRAN designated donors. Confirmed reactive anti-HIV, Western blot positive (WB+) results were greater in LAB than TRAN donors (1.664% vs 0.014%) on the first donation occasion. There were 43,982 donors who returned to donate on at least one other occasion. Of these, 43,778 designated TRAN initially, and only 217 (0.49%) changed their designation to LAB on any subsequent donation event. In contrast, of the 204 donors who designated LAB initially, 134 (65.6%) changed to TRAN on at least one other occasion. A variety of designation combinations from LAB to TRAN and back to LAB occurred. Thus, donors who initially LAB designated were more likely to change their designation on at least one other occasion than those who initially designated for TRAN. Of two donors who became anti-HIV WB positive on the second donation, one of these LAB designated on both occasions, was negative for anti-HIV by enzyme-linked immunoassay (EIA-) on the first donation but converted to EIA+, WB+ on the second.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Longitudinal follow-up of blood donors found to be reactive for antibody to human immunodeficiency virus (anti-HIV) by enzyme-linked immunoassay (EIA+) but negative by western blot (WB-).

A cohort of 467 volunteer blood donors who were found to be EIA+/WB- was studied longitudinally for up to two years. EIA screening for anti-HIV and WB testing, regardless of the EIA result, was performed on all 769 subsequent donation events of this cohort to ascertain the consistency of test results over time. The following results were obtained: 1) 8.8% of subsequent donation events were EIA+; 2) Most donors who returned were found to be EIA-/WB-; 3) EIA-/WB? (indeterminate) was 14.5 times more common than EIA+/WB?; 4) EIA and WB results were generally inconsistent from donation to donation; 5) No donor was found to be WB+. These results suggest that, in a volunteer donor population, an EIA+/WB- result may have little value in predicting anti-HIV test results and AIDS infectivity in a future donation. The current practice of not using blood donated subsequently by EIA+/WB- donors unless a re-entry testing scheme is satisfactorily completed should be reconsidered.

Blood Donors↗
PubMed1986

Anti-Rho(D) in two Rh-positive patients receiving kidney grafts from an Rh-immunized donor.

Kidneys from an Rh-negative cadaver donor were transplanted to two Rh-positive patients. The donor's serum contained anti-Rho (D). In both patients, anti-Rho (D) was detected in their serum and on their red cells 3.5 weeks after transplantation. One patient had hemolysis. The antibodies persisted for nearly six months, despite graft rejection and nephrectomy in one case. These antibodies presumably arose from passenger B lymphocytes in the grafts from the Rh-immunized donor.

Anemia, Hemolytic↗
PubMed1979

Inhibition of granulocyte erythrophagocytosis by HLA antisera.

The ability of HLA antisera to inhibit granulocyte erythrophagocytosis (EP) of opsonized red blood cells (RBC) was evaluated. Human granulocytes (PMN) were separated from heparinized whole blood by the Ficoll-Isopaque technique and suspended in McCoy's medium. EP occurred when the PMN were incubated with opsonized RBC. For six HLA antibody specificities evaluated, prior incubation of PMN with HLA antisera resulted in significant inhibition of EP without cytolysis when the PMN donor was positive for the specific HLA antigen, but not when the donor was negative for the antigen. The inhibition was time- and dose-dependent. Prior absorption of HLA antisera with HLA-specific platelets reduced or abolished the inhibition. An example of anti-NB1 also inhibited EP in 4 individuals. These data suggest that HLA antibody may adversely affect granulocyte phagocytic function. Inhibition of EP might be useful in evaluating compatibility prior to granulocyte transfusion.

Blood Platelets↗
PubMed1977

Plateletpheresis using the haemonetics model 30 cell separator.

Plateletpheresis using the Haemonetics Model 30 cell separator results in a mean collection of 5.5 X 10(11) platelets. This product contains substantial numbers of erythrocytes and mononuclear cells which can be effectively removed by centrifugation but with a 23% loss of platelets as well. The mean decrement in donor's platelet count during the procedure, which is 78,000/mm3, is not commensurate with the number of platelets collected suggesting donor platelet mobilization. Platelets collected by this technic, when transfused into unselected recipients, give platelet increments comparable to platelets produced in the standard batch manner.

ABO Blood-Group System↗
PubMed1975

Dissociation of MNSs antigens using sodium deoxycholate fraction of erythrocyte membranes.

A dissociation of the MNSs blood group system has been demonstrated by sodium deoxycholate fractionation of erythrocyte membrane preparations. The MN antigens were localized in a fraction that sedimented at 30,000 g while the Ss antigens remained soluble after 100,000 g centrifugation for donors who were heterozygous at the MN locus. In contrast, fractions derived from erythrocytes of 'homozygous' M or N donors showed M or N activity in both the 30,000 g pellet and 100,000 g supernatant and Ss remained in the 100,000 g supernatant.

Blood Group Antigens↗
PubMedDate not supplied

Granulocyte kinetics in donors undergoing filtration leukapheresis.

Normal blood donors undergoing filtration leukapheresis (FL) have a profound transient neutropenia early in the procedure which is followed by a "rebound" neutrophilia. This phenomenon occurs in unstimulated donors as well as in donors pretreated with either prednisone or dexamethasone. The mechanism for development of the neutropenia was investigated in volunteers throug a nylon filter at 37 C, a significant but transient neutropenia was observed. Plasma rendered cell and stroma-free achieved the same result indicating that plasma alone, when exposed to nylon fibers, is capable of producing neutropenia.

Blood Donors↗
PubMedDate not supplied

The acquisition of granylocytes by leukapheresis: a comparison of continuous flow centrifugation and filtration leukapheresis in normal and corticosteroid-stimulated donors.

Leukapheresis by continuous flow centrifugation (CFC) or filtration (FL) were compared in untreated and corticosteroid-treated donors. The administration of prednisone 60 mg orally 10 to 12 hours before leukapheresis increased significantly both the donor's prepheresis WBC counts and the total granulocyte yields by CFC or FL. Dexamethasone 6 mg iv at the start of FL did not increase granulocyte yields significantly. In untreated donors FL yielded 0.25 x 10(10) granulocytes per liter donor blood processed as compared with 0.05 x 10(10) per liter in CFC donors. Corticosteroid premedication has a greater relative effect in increasing yields by CFC than by FL. Donor reaction rates were between 4 and 6 per cent for both procedures.

Blood Donors↗
PubMedDate not supplied

Plateletpheresis residues: a source of large quantities of human blood lymphocytes.

The residue from single-donor plateletpheresis contains a large number of human mononuclear cells. We have been able to harvest more than 1 X 10(9) viable lymphocytes for laboratory study from the leukocyte-rich sediment that previously had been discarded. Prior to removal by adherence 5 X 10(8) monocytes were also available for future purification, if desired. The physical properties and response to phytohemagglutinin were very similar when lymphocytes isolated from plateletpheresis residues were compared with those obtained directly from veneous blood.

Blood Platelets↗
PubMedDate not supplied

Abdominal pain in donors during filtration leukapheresis.

An unusual donor reaction characterized primarily by lower abdominal and/or perineal pain occurs in 1.2 per cent of donors during filtration leukapheresis (FL). The reaction occurs almost exclusively in female donors. Corticosteroid pretreatment appears to be highly effective in preventing the reaction. The pathogenesis of this donor problem is speculative.

Abdomen↗