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Biomedical subjects

J F Bach

Publications and source records attributed to J F Bach.

At least 649 records · Page 36Linked to original sources

HLA-A1, B8-phenotype association and HBs antigenemia evolution in 440 hemodialyzed patients.

HBs antigen (HBsAg) has been followed up every month in 440 hemodialyzed patients, typed for 26 HLA alleles of the A and B loci. An abnormally high rate of the HL-A-A1, B8 association (18.6%) was found in the group of patients able to eliminate HBsAg, when compared with the normal French population (5.05%, p less than 10(-4), and with the group of patients unable to eliminate HBsAg (7.0%, less than 0.01). Chronic aggressive hepatitis was only found in the latter. This high frequency of the HLA-A1, B8 association has also been found in patients with seronegative active chronic hepatitis and suggests that this phenotype might be associated with high immune response against HBsAg.

Chronic Disease↗

Demonstration and characterization of a serum factor produced by activated T cells.

Spleen rosette forming cells (RFC) from adult thymectomized mice have a low sensitivity to inhibition by anitheta serum (AOS) and azathioprine (AZ) in comparison with normal spleen or thymus RFC. Thymus extracts and normal mouse serum (but not spleen extracts or thymectomized mouse serum) correct this abnormality after a 30 min in vitro incubation with spleen cells. We report here the existence of a serum factor produced in allogeneic reactions with the same activity on rosettes as thymic factor (TF). This 'allogeneic' factor (AF) is detectable in mice undergoing a graft versus host reaction (GVHR), rejecting skin allografts or allogeneic cells or responding to thymus-dependent antigens such as heterologous red blood cells or BSA. The T-cell origin of AF is indicated by AF presence in nude mice submitted to the same allogeneic stimuli as listed above and in normal mice injected with PVP or LPS. AF is distinct from the thymic factor as shown by differences in electric charge. Moreover, in contrast with TF there is no specific high molecular weight inhibitor of AF. Preliminary biochemical studies indicate that AF is probably a peptide of low molecular weight (greater than 5000 daltons). Its target cell is probably a T-cell precursor.

Animals↗

Relationships between antibodies to native DNA and glomerulonephritis in systemic lupus erythematosus.

Anti-native DNA antibodies have been evaluated in forty-six lupus patients' sera for antigen-binding capacity, affinity and precipitating activity. Diffuse proliferative glomerulonephritis was significantly correlated with the presence of high serum level of free anti-native DNA antibodies. Weak affinities were more often found in patients with than without glomerular changes but several patients had high-affinity anti-DNA antibodies and severe glomerulonephritis. No correlation was found between anti-DNA antibody-precipitating activity and renal lesions.

Antibodies, Antinuclear↗

[The action of D-penicillamine on the distribution of T and B-lymphocytes in rheumatoid arthritis].

Comparative study of the numbers of T and B lymphocytes in cases of rheumatoid polyarthritis treated and untreated with D-penicillamine shows that in the untreated subjects the distribution of these two types of lymphocytes is comparable with that in normal subjects and that D-penicillamine does not alter this distribution. This purely quantitative investigation does not rule out the possibility of functional modifications in the cells studied.

Adult↗

[Biochemical characterization of a circulating thymic factor].

A serum thymic factor has been isolated from pig serum. Its amino-acid sequence has been determined by Edman technique, modified by Gray: Gln-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn. A nonapeptide, synthesized on the basis of this sequence is active in the rosette assay used for the isolation of the biological product, both in vitro (10(-15) M) and in vivo (0.1 ng per Mouse).

Amino Acid Sequence↗

T lymphocytes in kidney allograft recipients.

The spontaneous sheep erythrocyte (E) rosette test was used on 340 occasions to measure T cell levels in 28 renal allograft recipients. The E rosette counts were reduced by high-dose steroids but usually returned towards normal under maintenance treatment with azathioprine and low-dose prednisone. Unexpectedly, rejection crises were more often associated with a decrease in E rosettes before steroid treatment (12 cases) than with an increase in E rosettes (5 cases). Our results show the need for caution in using the E rosette test and more generally B and T cell markers for monitoring anti-graft immunity in renal allograft recipients.

Azathioprine↗

Autoantibodies in D-penicillamine treated rheumatoid arthritis.

The D-penicillamine (D-Pen.) treatment can induce some diseases accompanied by autoantibodies: lupus, pemphigus, myasthenia. The authors present the results of a systematic study of autoantibody occurrence during D-Pen.-treatment of the rheumatoid arthritis (RA): (1) Anti-nuclear antibodies are slightly positive in 34% of the untreated RA. They appear or enhance in 44% of the treated patients (22/50). They reach high titers (1/500) in two clinical-induced lupus and in three asymptomatic cases. (2) Anti-native DNA antibodies are not found in untreated patients. They become markedly enhanced in two clinical lupus as in three asymptomatic cases (3/50). (3) Anti-epidermal intercellular substance-antibodies are absent in non-treated as well as on pemphigus-free treated patients (0/40). They are slightly elevated in 5 induced pemphigus. (4) Anti-striated muscle antibodies are absent in non-treated patients, rarely and moderately elevated (3/40) in the asymptomatic D-Pen.-treated group. These findings could have a practical interest for the survey of the treatment.

Adult↗

Determination of DNA antibodies in normal and pathological sera by a new counterimmunoelectrophoresis method.

A quantitative counter-immunoelectrophoresis technique has been applied to the evaluation of antibodies against native and single-stranded DNA. Anti-DNA antibodies have been found at high dilutions in patients with systematic lupus erythematosus, without correlation with the existence of renal lesions or with the degree of DNA binding assessed by Farr assay. Significant precipitates were also observed at significantly lower dilutions in other pathological situations and in normal subjects, posing the problem of the nature of the precipitates in these cases.

Antibodies↗

Thymic factors.

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Animals↗

Thymic hormone activity and spontaneous autoimmunity in dwarf mice and their littermates.

Serum thymic hormone activity (TA) was determined in hereditary hypopituitary dwarf mice (dw/dw) and their littermates (+/dw or +/+). It was found to be very low in the dwarf animals in comparison to their littermates. At 14 weeks of age, the dwarf littermates exhibited significant glomerular lesions characterized by deposits of IgG, IgG1, IgG2, IgA, IgM and C3, which were augmented by thymectomy of adult females. In contrast, hypopituitary dwarf mice had minimal glomerular deposits of immunoglobulins. Unlike these animals, their littermates showed antinuclear antibodies (ANA) and anti-deoxyribonucleic acid (DNA) antibodies in their serum. The present findings are discussed in relation to recent hypotheses on: (1) the role of the hypophysis in thymus-dependent immunological functions; and (2) the significance of T-cell deficiency in the development of autoimmunity.

Animals↗