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Biomedical subjects

B B Barrett

Publications and source records attributed to B B Barrett.

7 recordsLinked to original sources
PubMed1995

Characterization of reactions after exclusive transfusion of white cell-reduced cellular blood components.

BACKGROUND: Potential adverse effects of white cells (WBCs) within transfused cellular blood components include febrile nonhemolytic transfusion reactions (FNHTRs), alloimmunization, transmission of infectious diseases, transfusion-related acute lung injury, and immunomodulation. Although exclusive use of WBC-reduced components to prevent alloimmunization and cytomegalovirus transmission has been studied, the use of these components to avert FNHTR has not been examined. STUDY DESIGN AND METHODS: Transfusion reactions (FNHTRs, allergic reactions, and others) were characterized in recipients of 12,277 WBC-reduced single-donor apheresis platelets (SDAPs) and/or red cells (RBCs). Medical and laboratory evaluations for possible infectious and immunologic (alloimmunization) causes of each reaction were undertaken, and the benefit of further modification of components for the prevention of subsequent reactions was also evaluated. RESULTS: Transfusion reactions occurred after 481 (3.92%) of 12,277 transfusions. Allergic reactions occurred more commonly after transfusion of SDAPs (3.69%) than of RBCs (0.51%). Conversely, FNHTRs occurred more commonly after transfusion of RBCs (2.15%) than of SDAPs (1.58%). HLA antibodies were present in a posttransfusion sample from 27 (10.6%) of 255 patients; bacterial contamination was a possible cause of only 2 (0.42%) of 481 reactions. In patients with recurrent FNHTRs, further WBC reduction in components did not wholly prevent further FNHTRs. CONCLUSION: The incidence of FNHTRs and alloimmunization after exclusive transfusion of WBC-reduced RBCs and SDAPs was low. Further WBC reduction in components transfused to patients with a history of recurrent FNHTRs does not completely prevent subsequent reactions.

Antibodies↗
PubMed1979

Nonlinear least-squares regression programs for microcomputers.

Nonlinear least-squares regression can be performed on a microcomputer with BASIC language capability and 8K or more bytes of random access memory. At least five nonlinear regression programs written in BASIC exist, two of which have been implemented on microcomputers. These programs and some of their characteriscics are described. Advantages and disadvantages of performing nonlinear regression on microcomputers are contrasted with use of nonlinear regression programs requiring large computers.

Computers↗
PubMed1967

Chromatographic studies of sera from calves vaccinated with brucella abortus, strain 19.

The presence of antibody was detected by agglutination tests in the serum of calves four days after vaccination with Brucella abortus strain 19. Titres had reached a maximum by seven to ten days post-vaccination. Sucrose density-gradient ultracentrifugation demonstrated that the earliest antibodies were macroglobulins, IgM (19Sgamma; gammaM)-globulins. Lighter antibodies, IgG (7Sgamma(2); gammaG)-globulins, appeared a few days later. With time, antibody titres fell, IgM declining somewhat more quickly than IgG. After revaccination some seven months later, there was a rapid rise in both IgM and IgG.Anion-exchange column chromatography (DEAE-cellulose) and gel filtration (Sephadex G-200) were applied in separating the two forms of antibody. The former method, in which a gradient buffer system was used, proved to be the more efficient; the IgG antibodies apeared in early eluates at pH 7.8 to 8.0 and low ionic strength, 0.03M, whereas IgM was eluted late when the pH had fallen below 6.0 and the molarity had increased to beyond 0.2. DEAE cellulose chromatography detected IgG as well as IgM sera collected as early as five days after vaccination.

Agglutination Tests↗
PubMed1966

Anaplasmosis: comparison of complement fixation methods and study of the cattle population of southern Alberta.

The standard procedure for the complement-fixation test adopted in 1958 by the Animal Disease Eradication Division of the U.S. Department of Agriculture for testing of anaplasmosis was compared with the routine method used in our laboratory. In general a good agreement was observed between the two methods, although some standard control sera having a low titre in the U.S.D.A. test gave a slightly higher reaction in the A.D.R.I. test, whereas the reverse was observed with certain high titre control sera. None of the differences in titre were sufficient to change the interpretation of the tests.A survey of 3090 field samples collected from southern Alberta close to United States border detected 3 serological reactions in 3 different herds. In one of these, the animal was negative when retested 3 months later. In a second animal the serum titre was still present 11 weeks later but the blood from this animal failed to transmit infection to a susceptible splenectomized calf. In the case of the third herd the animal had been disposed of at the time of retest but all other animals in this herd at the time the reacting animal was examined were still serologically negative. This survey failed to reveal the presence of anaplasmosis in the Canadian animals investigated.

Alberta↗
PubMedDate not supplied

Effect of heat on the conversion of di-2-ethylhexyl phthalate to mono-2-ethylhexyl phthalate in human plasma.

Plasma di-2-ethylhexyl phthalate (DEHP), which accumulates during blood storage in plastic bags, gives rise to plasma mono-2-ethylhexyl phthalate (MEHP). This also in plasma samples awaiting analysis, which are no longer stored in plastic bags. Heating plasma samples at 60 C for 25 to 30 minutes in a water bath effectively halts conversion of DEHP to MEHP during subsequent room temperature storage for at least 100 hours. This result is consistent with the view that MEHP accumulation in plasma is due to enzymatic hydrolysis of DEHP by esterase (s) which can be heat-inactivated.

Blood Preservation↗
PubMedDate not supplied

Identification of the metabolites of di-(2-ethylhexyl) phthalate in urine from the African green monkey.

The metabolites of di-(2-ethylhexyl) phthalate (DEHP) found in urine from African Green monkeys after intravenous administration of the 14C-labeled parent compound were isolated and identified. Criteria of identification included cochromatography with rat-derived standards on direct-phase HPLC and a variety of gas-chromatographic columns, as well as correspondence of mass spectra (70-eV electron impact and methane positive chemical ionization) with those of known standards. Approximately 80% of the urinary metabolites were excreted in the form of glucuronide conjugates. This is analogous to what has been reported for the urinary metabolites of DEHP from humans, but in clear contrast to the metabolites found in rat urine. Rat urinary metabolites of DEHP are excreted unconjugated, and consist primarily of derivatives more highly oxidized than the major metabolites produced by monkey or human. It is suggested that the African Green monkey may be a better model for human metabolism of DEHP than is the rat.

Animals↗