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Biomedical subjects

B O Barger

Publications and source records attributed to B O Barger.

At least 73 records · Page 4Linked to original sources
PubMed1982

Properdin factor B and acute lymphocytic leukemia (ALL).

One hundred-sixty-four ALL patients were compared to 545 controls for differences in phenotype and gene frequencies at the Properdin factor B locus. In addition, 90 of the ALL patients were immune phenotyped. A significant association with the Bf F allele and ALL was found, resulting in an estimated relative risk of 3.62. There was no difference in the Bf S phenotype between ALL patients and controls. However, those homozygous for the Bf S allele are at a significantly low risk of 0.30 for developing ALL. ALL patients with a non-B/T cell type were 2.5 times more likely to be Bf SS homozygotes; in contrast, those patients with the pre-B cell type were 2.5 more likely to be Bf FF homozygotes. These data suggest association of the Bf locus with an ALL protection and/or susceptibility gene(s).

Alleles↗
PubMed1982

Seronegative rheumatoid arthritis. A distinct immunogenetic disease?

Measurement of serum rheumatoid factor (RF) by conventional methods in patients with rheumatoid arthritis (RA) has repeatedly identified a subpopulation of patients without detectable RF. Previous investigators have consistently confirmed the association of HLA-DR4 with seropositive RA, but studies of seronegative RA have been limited and contradictory. We studied 140 randomly selected patients from Alabama, all of whom had either classic or definite RA, and we were able to complete HLA typing for 110 of these individuals. Eighty were consistently seropositive (on at least 2 separate occasions) and 30 were consistently seronegative (on at least 3 separate determinations). There was no statistically significant difference between the seronegative RA patients and 123 control subjects in the distribution of DR antigens. In seropositive RA, there was a significant increase in DR4 (P less than 0.001; relative risk = 8.02; attributable risk = 49.2%) and a significant decrease in DR3 (P less than 0.001; relative risk = 0.14) and DR7 (0.01 greater than P greater than 0.001; relative risk = 0.33). The clinical data also distinguished between seropositive RA and seronegative RA; subcutaneous nodules (37.5%) and vasculitis (6.3%) were present only in seropositive RA. DR4 positively did not correlate with any of the clinical variables measured in the seropositive RA group. In contrast, DR4 in the seronegative RA group was associated with more destructive disease. The data suggest that seronegative RA represents a disease entity clinically and immunogenetically distinct from seropositive RA. Moreover, our results indicate that DR4 may be a previously undisclosed marker for disease severity in seronegative RA.

Arthritis, Rheumatoid↗
PubMed1982

Associations of properdin factor B with melanoma.

We investigated 98 melanoma patients and 135 normal controls for differences in phenotype and genotype frequencies at the properdin factor B locus. A significant negative association with the Bf-F allele and melanoma was found, resulting in an estimated relative risk of 0.5. The estimated relative risk for developing melanoma among people with the Bf-FF genotype is 0.07. The Bf-S phenotype was significantly increased among the melanoma sample, with an estimated risk of 6.5. The data suggest association of the Bf locus with a melanoma protection and/or susceptibility gene(s).

Complement Factor B↗
PubMed1982

HLA-A, -B, and -DR associations in type I diabetes mellitus with onset after age forty.

It remains to be convincingly demonstrated whether insulin-requiring, ketosis-prone, lean-at-onset, type I diabetics who develop their disease after age 40 have the same disease as the children with similar characteristics. To address this question, we examined the population HLA genetic associations of this group. One hundred forty white, insulin-using diabetics with onset of disease past age 40 yr and 268 normal white controls have thus far been analyzed for HLA type. In the group of patients who were lean-at-onset and/or ketosis-prone (N = 54), there was a significantly increased frequency of DR4 (RR = 4.63; P less than 0.01) and significantly decreased frequency of DR2 (RR = 0.18; P less than 0.05) after correction. DR4 was also significantly increased after correction (RR = 5.72; P less than 0.25) in the subgroup who were both lean and ketosis-prone (N = 23). No significant differences in HLA-DR frequencies were found between the obese and not-ketosis-prone group (N = 69) and controls. No significant associations of HLA-A or-B antigens with either group were observed after correction for the number of antigens tested. To our knowledge, this is the first such study in the United States, and the first demonstrating that late onset diabetics who are lean-at-onset and/or ketosis-prone exhibit HLA-DR antigen associations which are similar to early onset cases.

Adult↗
PubMed1982

Evidence for genetic admixture as a determinant in the occurrence of insulin-dependent diabetes mellitus in U.S. blacks.

In recent years, it has been proposed that genetic admixture may have played a role in the increased frequency of insulin-dependent diabetes mellitus (IDDM) in young U.S. blacks relative to African blacks. In support of this proposal, the similar associations of specific markers of the major histocompatibility complex (MHC) with IDDM in U.S. blacks with respect to U.S. whites have been cited. To determine whether racial admixture was a factor in the increased prevalence, we did three analyses of admixture. In the first we used nine genetic markers (ABO, Rh, Fy, Hp, Gc, Pl, OR, Tfr, and Gm) and determined that there was significantly greater than zero genetic contribution from whites in our sample of U.S. black IDDM patients (9.6 +/- 2.3%, P less than 0.01) when a sample of U.S. blacks without IDDM was used as one "parental" population. In the next two analyses, we estimated the amounts of genetic contribution from whites in the U.S. blacks with and without IDDM using reported gene frequencies for West African blacks for four genetic markers (ABO, Rh, Fy, and Hp). The estimate of admixture (21.4 +/- 2.8%) for the black IDDM sample was greater than that for the U.S. black controls (17.9 +/- 2.3%), although the difference was not significant. Our estimate of genetic contribution from whites, 21.4% for black IDDM patients, supports the assumptions of 20% admixture which MacDonald and Rotter and Hodge used to test their respective models for the inheritance of IDDM. These results support the hypothesis that admixture with the white population is, in part, responsible for the increase in prevalence of IDDM seen in U.S. blacks.

Black People↗
PubMed1982

Increase of HLA-DR4 in melanoma patients from Alabama.

This report describes the association of HLA-DR phenotypes in a population of 91 Caucasian melanoma patients compared with 106 Caucasian controls from the Sunbelt region of the United States. Over 75% of both patients and controls were born in Alabama or a surrounding state. There was a significant increase in the frequency of HLA-DR4 (chi 2 = 12.8; rho = 0.0003). This was present in 38.5% of the patients compared to a 16.0% frequency in the controls, producing a relative risk of 3.3. The difference in DR4 distribution remained significant after correcting for the number of antigens (rho c = 0.0018). The patients were then grouped into two categories, "low risk" and "high risk," based on their clinically assessed risk at presentation for metastatic involvement. The decrease of DR3 in the high-risk group (chi 2 = 5.2; rho = 0.02) suggested that it may represent a marker for long-term survival. Thus, it appears that susceptibility to developing melanoma may be associated with DR4 while survival may be associated with DR3.

Alabama↗
PubMed1981

HLA associations with insulin-dependent diabetes mellitus in a sample of the American Black population.

It has been of considerable interest to determine if the HLA associations with insulin-dependent diabetes mellitus (IDDM) in blacks are the same as in whites in the United States. Seventy-nine black IDDM patients who were under the age of 40 at onset 283 black controls were HLA typed for A, B and C specificities. This is the largest sample of black IDDM patients yet reported. Analysis of HLA antigen frequencies for these samples has revealed an increased frequency of HLA B8 (p less than 0.01), B3 (p less than 0.02) and B15(p less than 0.006), and a decreased frequency of B14 (p less than 0.01). The estimate of relative risks for B8 and B15 was 2.6 and 4.4, respectively. Comparison of a subsample of the black patients (n = 61) and controls (N = 137) revealed increased frequencies of DR3 (p less than 0.0004), DR4 (p less than 0.0002), and DR7 (p less than 0.03) in the IDDM patients. Both HLA DR2 and DR5 were decreased in the diabetic patients (p less than 0.0001 and p less than 0.0002, respectively). All p values were uncorrected. The associations of HLA antigens with IDDM in our black American sample are essentially the same as those found in white IDDM patients. This suggests that the occurrence of IDDM in American blacks may be due to admixture of white genes.

Adolescent↗
PubMed1981

Properdin factor B polymorphism in Black Americans.

Properdin factor B is a genetically-controlled polymorphism that can be demonstrated by agarose gel electrophoresis. The Bf gene frequencies were determined for 194 blacks from the south-eastern United States. The frequencies for Bf-F, Bf-S, Bf-F1, and Bf-S1 are 0.626, 0.034, and 0.013, respectively. The south-eastern blacks have similar Bf frequencies to the South African blacks; however, both these groups are different from blacks from Boston. The frequency differences between south-eastern blacks and Boston blacks may be due to racial admixture differences found in the two populations.

Black People↗
PubMed1979

Local antibody response in chickens: analysis of antibody synthesis to Newcastle disease virus by solid-phase radioimmunoassay and immunofluorescence with class-specific antibody for chicken immunoglobulins.

The antibody response to Newcastle disease virus was monitored in the sera and salivas of adult chickens immunized by two methods: (i) combined intratracheal-intranasal vaccination followed by intratracheal revaccination or (ii) intramuscular vaccination followed by intratracheal revaccination. By solid-phase radioimmunoassay, only immunoglobulin G (IgG) and IgA antibodies to Newcastle disease virus were detected in the salivas, whereas IgA and IgM antibodies were present in egg whites. The first method produced the highest antibody levels in both serum and saliva and, in addition, prevented detectable virus multiplication in the respiratory tracts upon revaccination 4 weeks later. Plasma cells of all three classes were distributed throughout the tissues lining the oral cavities. The highest densities of plasma cells were in the Harderian glands; IgG was the predominant class, whereas IgA and IgM plasma cells were present in almost equal but lower numbers. The Harderian plasma cells were the most likely source of the antibody found in saliva.

Animals↗
PubMed1978

Specific antigens of chicken thymus.

Purified plasma membranes from chicken thymus and bursa cells were prepared and solubilized with sarkosyl (sodium salt of N-methyl-N-(1-oxodecyl)-glycine). Antisera to solubilized thymus plasma membrane (TPM) were produced in rabbits and the globulin fraction obtained by ammonium sulfate precipitation. Four precipitating antigens were detected in solubilized TPM by immunoelectrophoresis. Following absorption with chicken serum and bursa plasma membrane (BPM) immunosorbents, three antigens, designated T1, T2, T3, were specific for the TPM fraction, and one antigen, T1, was found in soluble extracts of thymus tissue. Absorption with isolated plasma membrane and whole cells indicated that the T1 and T2 antigens in solubilized TPM are associated with the plasma membrane but not expressed on the surface of the cell. A common antigen, designated BT, was detected in BPM and TPM fractions and in membrane preparations of spleen. The antigens were not detected in any other tissues or cells including brain, circulating lymphocytes and erythrocytes.

Animals↗
PubMed1977

Comparison of the efficacy and transmissibility of conventional NDV vaccines and vaccines prepared after back-passage through chickens.

In laboratory trials B1 and Lasota stains of Newcastle disease virus (NDV) back-passaged in chickens were found to have a greater spreading potential than presently available B1 and Lasota vaccines. Although the regular B1 and Lasota strains of NDV gave a routine serologic response when administered to 4-week-old chickens via the water, both vaccines had a low spreading potential since the geometric mean titer of the birds in contact with the B1 vaccinated birds did exceed 3.4 and the HI response of the nonvaccinated birds placed with the Lasota vaccinated birds did not exceed 4.1. The results from this study also indicate that these back-passaged vaccines elicit higher HI titers and are possibly more invasive than the regular B1 and Lasota vaccines. The data also suggest that the Lasota strain possesses a slightly greater spreading potential than the B1 strain of NDV.

Administration, Oral↗