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Biomedical subjects

W L Bayer

Publications and source records attributed to W L Bayer.

At least 19 recordsLinked to original sources
PubMed1992

Use of platelets and other transfusion products in patients with malignancy.

The need for blood components for oncology patients is small compared with the need for patients with hematologic malignancies. Appropriate use of blood components is necessary, not only medically, but also because of limited supply and availability. Agreement on when to use components is extremely important. In fact, at the time of this writing, the Transfusion Practices Committee of the AABB is conducting an extensive survey on the use of platelets in the oncology and hematology cancer patients (Questionnaire on Institutional Policy on Platelet Transfusion Practice for Hematology/Oncology Patients). The results will, it is hoped, provide a consensus on the proper times and counts that require prophylactic use of components for these patients. Since these patients use the vast majority of components (see Table 15), their proper use is imperative to maintaining an adequate platelet and frozen plasma supply. Transfusion support in cancer patients is vital for their survival. Platelets, in particular, are necessary to prevent serious bleeding. However, refractoriness to platelet transfusions can develop. It must be appreciated that refractoriness is not a general problem and need not require the expensiveness of a universal decision for handling all platelet transfusions in the same manner. Total refractoriness probably occurs in 15 to 20% of patients frequently transfused. In patients in whom frequent platelet transfusion is anticipated, that is, bone marrow transplantation, the development of platelet refractoriness may be reduced by using SDPC and administering them through leukocyte filters. Patients who become refractory to either random or SDPC can either be cross-matched for single-donor platelets that are compatible or can be given HLA-A,B matched platelets. Certainly, the success of platelet transfusion in leukemic patients cannot be denied, since only a small number of these patients now die because of bleeding due to platelet refractoriness. Most of the serious bleeding still seen is associated with sepsis. The risks from transfusion must always be considered. Fortunately, with increased monitoring of the blood supply, they have been reduced. As with any therapeutic regimen, these risks must be weighed against the benefit the patient may gain. Transfusion should always be used prudently.

Blood Component Transfusion↗
PubMed1992

Use of blood components in cancer patients with bleeding.

The need for blood components for oncology patients is small compared with the need for patients with hematologic malignancies. The subject is important because use of these valuable components is dependent on a limited supply and availability. Agreement on when to use components is extremely important. In fact, at the time of this writing, the Transfusion Practices Committee of the American Association of Blood Banks is conducting an extensive survey on the use of platelets in oncology and hematology cancer patients (Questionnaire on Institutional Policy on Platelet Transfusion Practice for Hematology/Oncology Patients). The results will, we hope, provide a consensus on the proper times and counts that require prophylactic use of components for these patients. Because these patients use the vast majority of components (see Table 15), their proper use is imperative to maintaining an adequate platelet and frozen plasma supply. Transfusion support in cancer patients is vital for their survival. Platelets, in particular, are necessary to prevent serious bleeding. The risks from transfusion must always be considered. Fortunately, with increased monitoring of the blood supply, they have been reduced. As with any therapeutic regimen, these risks must be weighed against the benefit the patient may gain. Transfusion should always be used prudently.

Blood Coagulation Disorders↗
PubMed1991

The use of a recombinant immunoblot assay in the interpretation of anti-hepatitis C virus reactivity among prospectively followed patients, implicated donors, and random donors.

Samples from prospectively followed recipients, their respective donors, and a cohort of random donors were used to evaluate the specificity and efficacy of a recombinant immunoblot assay (RIBA) as an adjunct to anti-hepatitis C virus (HCV) testing by enzyme immunoassay (EIA). RIBA reacted (RIBA+) in 100 percent of patients who developed hepatitis associated with anti-HCV seroconversion documented by EIA and in 100 percent of the EIA-positive (EIA+) donors implicated in these cases. In contrast, RIBA reacted in none of 10 recipients who were EIA+ but did not develop hepatitis, in none of 7 EIA+ patients with hepatitis B or cytomegalovirus infection, in 33 percent of EIA+ donors who were not implicated in hepatitis transmission, and in 37 percent of EIA+ random donors. Hence, the vast majority of EIA+ individuals who have ancillary evidence of HCV infection react on RIBA, whereas the majority of EIA+ individuals in low-risk settings do not react (RIBA-negative, or RIBA-). There was a strong association between RIBA reactivity and the presence of a surrogate marker (elevated alanine aminotransferase [ALT] and/or antibody to hepatitis B core antigen); 43 percent of RIBA+ implicated donors had a surrogate marker as compared to none of 14 EIA+, RIBA- donors. Among EIA+ random donors, 77 percent of those with a surrogate marker were RIBA+, as compared with 29 percent of those without a surrogate marker. In addition, in EIA+ donors, RIBA reactivity correlated with the extent of ALT elevation; 86 percent of those with an ALT greater than 135 IU per L were RIBA+ compared with 18 percent of those with an ALT less than 30 IU per L.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood↗
PubMed1991

Voluntary human immunodeficiency virus testing: acceptance levels and identification of seropositive individuals.

Of 4340 clients of a clinic for those with sexually transmitted diseases who were eligible for voluntary, confidential, serologic testing for the human immunodeficiency virus, 4246 (97.8%) consented to testing; 23 (0.5%) were seropositive. Of 94 persons who declined voluntary testing but who were tested in a blinded study, nine (9.6%) were seropositive. Seropositive persons who declined voluntary testing did not conceal their association with a risk group, while only 61% of seropositive individuals who accepted voluntary testing admitted to inclusion in a risk group before the test. Voluntary testing appears to be insufficient, because 28% of the seropositive individuals were not identified as being seropositive; also, there was a significant deficiency associated with identification of risk at pretest counseling among persons agreeing to voluntary testing.

AIDS Serodiagnosis↗
PubMed1987

Use of capillary blood for the evaluation of iron status.

The accuracy and precision of measurements of iron status made on the capillary blood from a single 75 X 1-mm microhematocrit tube were evaluated in 301 normal volunteers. After recording the hematocrit value, a hematofluorometer was used to assay erythrocyte protoporphyrin directly on the packed red cell fraction. Values in the low normal range were 50-100% higher than assays by an extraction technique in simultaneously collected venous blood. However, measurements in the iron deficient range were only 12% greater. Plasma ferritin concentration was determined by using an enzyme-linked immunoassay on 10-microliters plasma retrieved after measuring the hematocrit. Capillary values were approximately 7% higher than venous concentrations, the proportional difference being consistent throughout the measured range. When the individual measurements were combined to calculate the iron storage status of each individual, the frequency distribution of iron stores in 141 female volunteers between 18 and 36 years of age was approximately Gaussian and paralleled that calculated for women aged 18-44 years in NHANES II. These studies demonstrate that iron status can be determined accurately from the measurement of hematocrit, erythrocyte protoporphyrin, and ferritin on a single microhematocrit tube of capillary blood.

Adolescent↗
PubMed1986

AIDS retrovirus antibodies in hemophiliacs treated with factor VIII or factor IX concentrates, cryoprecipitate, or fresh frozen plasma: prevalence, seroconversion rate, and clinical correlations.

Antibodies to the AIDS retrovirus, specifically to human T cell lymphotropic virus, type III, and AIDS-associated retrovirus, were detected with increasing prevalence in a population of 190 hemophiliacs from western Pennsylvania between 1981 and 1984: 7.7% in 1981, 20.0% in 1982, 45.5% in 1983, and 62.5% in 1984. The seropositive included approximately three fourths of those receiving factor VIII concentrate, nearly one third of those receiving factor IX concentrate, nearly one fifth of those receiving cryoprecipitate, and none of those receiving fresh frozen plasma. The seroconversion rate, determined on 43 seropositive hemophiliacs from this group who were serially sampled, was 0% in 1977, 4.7% in 1978, 4.9% in 1979, 2.6% in 1980, 10.5% in 1981, 52.9% in 1982, 87.5% in 1983, and 100% in 1984. Of 27 seropositive for three or more years (since 1982 or before), four (15%) have developed AIDS and seven (26%), diffuse lymphadenopathy (ARC); of 16 seropositive for less than three years, none has developed AIDS and three (19%) have developed ARC. The mean time from seroconversion to onset of ARC, 0.8 +/- 0.2 years (SEM), was shorter (P less than .001) than the time to onset of AIDS, 4.1 +/- 0.6 years. These findings confirm the widespread presence of AIDS retrovirus and support the association of these retroviruses with the acquired immunodeficiency syndrome and related conditions.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Early and late antigens of human cytomegalovirus: electroimmunodiffusion assay of numbers, relationships, and reactivities with donor sera.

Early antigens (EA) of human cytomegalovirus extracted from cytosine arabinoside-blocked cells infected with 0.01-20 infectious units (IU)/cell were assayed with human serum by electroimmunodiffusion (EID). The number of detectable EA types increased from one to eight as the IU/cell was raised from 0.01 to 10. There was no increase in the number of EA with further increases in IU/cell, with prolonged culture, or when detergent was included in the extraction buffer. At least five of the eight EA gave reactions of identity with late-time antigens (LTA) extracted from unblocked cells at late times postinfection. In studies on a panel of sera from donors who were excreting virus and donors who were not, EID was as sensitive as conventional techniques (complement fixation and indirect hemagglutination for LTA, indirect immunofluorescence for EA) in detection of both types of antibodies from excretors but less sensitive in not detecting low levels of the antibodies in some of the sera from nonexcretors. No consistent relationships were observed between donor virological status and the numbers or types of antibodies to EA and LTA.

Antigens, Viral↗
PubMed1984

Relation of titers of antibodies to CMV in blood donors to the transmission of cytomegalovirus infection.

Titers of antibody to cytomegalovirus (CMV) of 529 persons whose blood had been supplied to 51 selected patients who underwent open-heart surgery were determined by indirect hemagglutination (IHA) and IgM-specific indirect immunofluorescence (IFA). Twenty-eight patients showed evidence of active CMV infection after transfusion (seroconversion or a fourfold rise in titer by IHA), whereas 23 showed no serological change. Patients with active CMV infections had received, on average, a greater number of blood units (12.9 vs. 7.9), of which more were seropositive (6.9 vs. 3.5), than did patients who showed no serological change. Those seropositive units of blood that had been transfused into the group that showed evidence of active infection, however, had a lower geometric mean titer than did those transfused into the group that showed no serological change (1:654 vs. 1:1,360). Seven (1.3%) of the 529 blood donors had CMV-specific IgM titers (by IFA) of greater than or equal to 1:16; each of the seven recipients of their blood subsequently showed evidence of active CMV infection. This study suggests that donor blood with high IHA titers may prevent transmission of CMV infection, whereas blood from donors with IgM antibody to CMV may transmit CMV.

Antibodies, Viral↗
PubMed1982

Detection of antibodies to cytomegalovirus by an improved counterimmunoelectrophoretic procedure.

An improved counterimmunoelectrophoretic (CIE) procedure for detection of antibodies to human cytomegalovirus (CMV) is described. The procedure, which uses high ionic strength buffer and concentrated antigen, is as sensitive and specific as complement fixation (CF), indirect hemagglutination (IHA), and anti-complement immunofluorescence (ACIF) but requires concentration of some sera. In studies on sera from 118 normal blood donors, the percent correlation of CIE results with those by CF, IHA, and ACIF were 97.5, 98.3, and 98.3, respectively, and exceeded slightly the correlations among the latter three procedures. The appearance of precipitation immediately or early after a CIE run and of more than one line of precipitate was indicative of high titers by the other procedures, while single lines of late precipitation occurred with most low titer sera but also with many of those of high titer.

Antibodies, Viral↗
PubMed1979

Antigens of human cytomegalovirus: electroimmunodiffusion assay and comparison among strains.

The antigens of strain AD169 of human cytomegalovirus (CMV) were extracted by various methods and at different times following the appearance of cytopathic effects (c.p.e.) in infected fibroblasts. Assay with a pooled human serum in electroimmunodiffusion (EID) revealed that the most reactive preparations were obtained by shell-freeze (SF) extraction on the fourth day after 4+c.p.e. As many as 20 antigens could be detected in the original gels, most of which were stable upon storage at 4 degrees C for up to 4 weeks; of these, about 14 can be reproducibly seen on photographs. EID runs on day 4 SF preparations from high-passage CMV strains C87 and Davis and low passage recent isolates VD14, 1694 and 1723 resolved, respectively, 15, 15, 13, 11 and 11 antigens in the original gels (11, 9, 11,8 and 9 are visible in photographs). Strains 1694 and 1723 shared fewer antigens with one another and with high passage strains than were shared among the latter, whereas VD14 had relatively large numbers of antigens common to both low and high passage strains. At least six antigens were common to all strains.

Antigens, Viral↗
PubMed1975

A serum haemagglutinating property dependent upon polycarboxyl groups.

A serum agglutinin reactive with red cells in the presence of polycarboxyl groups is reported. It is likely that this represents an additional example of the type of agglutinin previously described as agglutinating red cells in the absence of ionized calcium. Experimental evidence is presented indicating that it is free polycarboxyl groups that potentiate agglutination and that any metal ion, such as calcium, capable of chelating with these groups will prove to be inhibitory.

ABO Blood-Group System↗
PubMed1975

Cytomegalovirus infection in a volunteer blood donor population.

Among 223 volunteer blood donors who were studied for evidence of cytomegalovirus (CMV) infection, 58 percent had complement-fixing antibody and 59 percent had indirect hemagglutinating antibody to CMV. No virus was isolated from any donor's washed leukocytes or leukocyte-rich plasma in fibroblast monolayer culture. In seven asymptomatic donors (3 percent), CMV was recovered from urine cultures obtained at the time of blood donation. However, at the time of reexamination, viruria was no longer present and serum antibody titers had not changed. In the three patients studied who received blood from three of the cytomegaloviruric donors, serological evidence of CMV infection developed (fourfold or greater indirect hemagglutinating antibody rise), and one recipient also developed cytomegaloviruria; no illnesses was associated with these infections. Further study is needed to establish that the detection of viruria in donors may identify potentially infective blood.

Antibodies, Viral↗