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Biomedical subjects

D N Hart

Publications and source records attributed to D N Hart.

141 records · Page 8Linked to original sources
PubMed1981

Localization of HLA-ABC and DR antigens in human kidney.

Monoclonal antibodies to human monomorphic class I and class II major histocompatibility complex (MHC) determinants have been used with immunofluorescence and immunoperoxidase techniques, to localize these antigens in normal human kidneys. HLA-DR antigen was located in the glomeruli (probably on endothelium as well as the mesangium) and within the cells of cortical and medullary tubules. Dendritic cells in the renal interstitium stained brightly for the DR antigen and could be distinguished from the staining of capillary endothelium. The vascular endothelium of large vessels stained less densely for the HLA-DR antigen than for HLA-ABC antigens. The glomeruli stained intensely for the HLA-ABC antigens and diffuse staining of HLA-ABC antigens was also noted within renal tubular cells.

Animals↗
PubMed1981

Passive enhancement of rat renal allografts using mouse monoclonal xenoantibodies.

These studies test the effectiveness for passive enhancement of rat renal allografts of mouse monoclonal xenoantibodies to rat major histocompatibility complex (MHC) antigens. Two fully characterized, noncytotoxic monoclonal antibodies, both of which show some allospecificity, were tested in several different MHC-incompatible strain combinations chosen such that the monoclonal antibodies reacted with the donor but not the recipient strain. The antibody F21-105-1, directed at RT1-A (class I) antigens, interacts with all strains tested except the PVG/c strain and was tested in the LEW to PVG/c and WAG to PVG/c combinations. The antibody F17-23-2, directed to RT1-B (class II or Ia) antigens, interacts with all strains tested except the PVG/c, AUG, and WAG strains and was tested in the LEW to PVG/c and LEW to WAG combinations. Our results demonstrate that noncytotoxic monoclonal xenoantibodies are effective for passive enchancement but that in strong donor-recipient combinations they might not be quite as effective as conventional allosera. Nevertheless, they are likely to be useful reagents for testing the efficacy of passive enhancement in the clinical situation.

Animals↗
PubMed1980

Kidney-specific alloantigen system in the rat. Characterization and role in transplantation.

The alloantibody response of LEW rats immunized with DA kidney homogenate or given vascularized DA kidney grafts was studied using an 125I-anti-Ig binding assay with kidney homogenate as the target tissue. A major component of the sera was found to be directed at a kidney-specific alloantigen. Analysis of LEW X (DA X LEW) F1 backcross rats showed that the locus coding for this antigen was not linked to the major histocompatibility complex (MHC). The use of these backcross rats, typed for both MHC and the kidney alloantigen, as kidney donors to LEW rats showed that the kidney alloantigen did not induce detectable graft damage and that only the DA MHC was involved in primary graft rejection of DA kidneys by LEW rats. Immunofluorescence studies localized the antigen to the basement membrane of proximal convoluted tubules, and to some Bowman's capsules. Strain distribution studies showed that only 2 of 11 strains were negative for the allele under study; these were the LEW and AS strains. Species cross-reactivity studies showed that rabbit, dog, and human kidneys could absorb this specificity, although more weakly than DA kidney.

Animals↗
PubMed1980

Distribution and quantitation of HLA-ABC and DR (Ia) antigens on human kidney and other tissues.

A quantitative estimation of the amounts of human Ia (HLA-DR) and HLA-ABC antigen on a variety of human tissues was performed. Monoclonal antibodies to species-common determinants of HLA-DR and HLA-ABC antigens were absorbed quantitatively with tissue homogenates and cell suspensions, and reassayed for residual activity in a radioimmunobinding assay. Kidney was found to carry 90% as much HLA-DR and 14% as much HLA-ABC antigen as spleen, while liver contained 19 and 9% as much, respectively. Small amounts of both antigens were found on heart; brain carried very little HLA-ABC and virtually no DR. Neither HLA-ABC nor DR was found on erythrocytes or reticulocytes. Of interest was our finding that a small subpopulation of thymocytes (10%) was HLA-DR positive. Platelets contained approximately 5% of the amount of HLA-ABC as spleen and undetectable quantities of HLA-DR, as expected. Chronic lymphatic leukemia (CLL) cells were found to carry 10% as much HLA-ABC and 33% as much DR antigen as spleen, while the values for bone marrow were 15 and 2%, respectively.

Fluorescent Antibody Technique↗
PubMed1980

Passive enhancement and hyperacute rejection of renal allografts in the rat.

Attempts to induce passive enhancement of renal allografts with donor-specific cytotoxic antibody can result in antibody-mediated damage to the grafted organ. Hyperacute renal allograft rejection occurred in the homozygous DA to Lewis strain combination when Lewis anti-DA serum was administered with guinea pig complement. Hyperacute rejection was prevented in four of five rats when Lewis anti-DA F(ab')2 was injected before the administration of Lewis anti-DA serum and complement and these grafts had enhanced survival. Red blood cell absorption of the Lewis anti-DA serum to produce an anti-Ia-like serum, also removed its ability to produce hyperacute rejection without removing its ability to enhance. With appropriate modifications both of these techniques would be applicable to human transplantation.

Absorption↗
PubMed1980

Kidney-specific allo- and autoantibodies in the alloantibody response to rat kidney: the use of kidney homogenate as a target for serological analysis.

LEW anti-DA kidney and DA anti-LEW kidney sera were assayed using an indirect 125I anti-immunoglobulin-binding assay with kidney homogenate as target. This allowed the full spectrum of antibodies to be analysed since the tissue used for immunization was the same as that used as the target in the serological analysis. It was found that around 80% of the LEW anti-DA kidney serum was directed at kidney-specific antigens, approximately half at a kidney-specific alloantigen, and half at a kidney-specific autoantigen. Only a small component, around 20% of the antibodies, was directed at major histocompatibility complex (MHC) antigens. In contrast, the DA anti-LEW kidney serum, which was much weaker, was directed entirely at autoantigens, and was more complex in that at least two autoantigens were involved. None of the DA and LEW kidney autoantibodies reacted with lymphocytes. The potential of this assay system for the study of tissue-specific antibodies, especially autoantibodies in man, is discussed.

Animals↗
PubMed1979

Quantitative studies on the tissue distribution of Ia and SD antigens in the DA and Lewis rat strains.

The tissue distribution of major histocompatibility complex (MHC) antigens in the DA and Lewis (LEW) strains was studied using LEW anti-DA and DA anti-LEW alloantisera. Quantitative absorption analyses were used with quantitative binding assays for SD and Ia antigens. Initial screening showed that the LEW anti-DA serum contained significant amounts of antibodies against both Ia and SD antigens. On the other hand, the DA anti-LEW serum seemed to be directed almost entirely against Ia antigens, and it was not possible to set up assays for SD antigens in the LEW strain. The most surprising finding was the presence of large amounts of Ia antigen on the kidneys of both the DA and LEW strains, one kidney containing as much Ia antigen as half a spleen. Kidney also contained large amounts of SD antigen. Liver had large amounts of SD, but very little Ia. Heart had only small amounts of both SD and Ia. The relevance of these findings to transplantation of the kidney, liver, and heart are discussed. The other tissues studied were brain, spleen, lymph node, thoracic duct lymphocytes, bone marrow, thymus, RBC, and platelets. The most interesting findings were the presence of relatively large amounts of SD antigens on DA RBC, and small amounts of Ia on the thymus and bone marrow.

Animals↗
PubMed1975

Christchurch traffic trauma survey: Part 2, victims and statistics.

The results of a survey carried out at Christchurch Hospital examining the problem of traffic trauma are described. The majority of casualties were in the 15-24 age group and motorcyclists were especially prominent. The type and severity of injuries is discussed for each role, e.g., driver, passenger etc. The availability and use of safety equipment (seat belts and crash helmets) by the victims who came to hospital is also detailed. Accidents were found to occur predominantly (88 percent) in urban areas and very close to the victim's home.

Accidents, Traffic↗
PubMed1975

Christchurch traffic trauma survey: Part 1, Blood alcohol analysis.

Some accurate information concerning the drivers involved in traffic accidents was obtained in a survey at Christchurch Hospital. Investigation of these drivers' occupations revealed that a significant proportion came from the semi-skilled and unskilled occupational groups. Alcohol is confirmed as an important factor in traffic accidents and a number of other characteristics of the drivers are described. The dangers of relying on officially-acquired statistics for research work are revealed.

Accidents, Traffic↗
PubMedDate not supplied

Adolescent and adult lymphoblastic leukaemia: prognostic factors and response to treatment.

Thirty consecutive patients with acute lymphoblastic leukaemia (ALL) who received treatment at Christchurch Hospital between 1972 and 1982 were reviewed. Complete remission (CR) was achieved in 80 per cent with a median survival of 65 weeks. Eleven of 30 patients had one or more of the following features--B cell ALL, a mediastinal mass, the Philadelphia chromosome (Ph1) and age 60 years or older at diagnosis. Although CR was obtained in 8 of these patients none survived three years. The remaining 19 patients were regarded as 'good risk' and treated by moderate intensity chemotherapy schedules. CR was obtained in 16 of these patients (84 per cent) and the estimated 5 year survival was 62 per cent with 6 patients remaining in remission from 5 to 9 years from diagnosis. These results demonstrate the value of objective and reproducible clinical and laboratory findings in defining a subset of ALL patients which may not require high intensity chemotherapy schedules.

Adolescent↗
PubMedDate not supplied

A cytological analysis of FMC-7 positive leukaemias.

The subdivision of the B lymphoid leukaemias by conventional techniques is subjective and poorly reproducible, with a range of cytological diagnoses available for cases which are not typical examples of chronic lymphatic leukaemia or acute lymphoblastic leukaemia. The monoclonal antibody FMC-7 recognizes a determinant on a subpopulation of B lymphoid cell and stains follicular B cells. Routiune FACS analysis of chronic lymphoid leukaemias with a panel of monoclonal antibodies identified a subset of lymphoproliferative disorders (20 of 88) which were FMC-7 positive. a careful 'blind' cytological assessment of this subset gave some support for the suggestion that they were examples of lymphoproliferative disease of follicular origin. Eight cases, however, were considered cytologically typical of CLL. The wider application of this antibody, particularly in sequential studies over a longer time scale may improve objectivity in the classification of this group of diseases.

Antibodies, Monoclonal↗