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Biomedical subjects

M Segall

Publications and source records attributed to M Segall.

At least 55 records · Page 3Linked to original sources
PubMed1983

Planning and politics of resource allocation for primary health care: promotion of meaningful national policy.

Securing resources for primary health care (PHC) involves consideration of the entire health sector: the higher levels of the health service as well as the primary level, and the private and/or social security sub-sectors as well as the government service. Reshaping resource distribution is less a redistribution of existing resources than the allocation of new resources in accordance with PHC priorities. In this the planning of future current costs is a crucial element and requires a budgetary system that identifies expenditures by geographical area and level of care. Resources should be allocated geographically to reduce health care inequalities through the provision of an appropriate mix of different levels of care. Central resource planning and local health care programming (with 'dialogue' between the two) should be the basic planning division of labour, which largely resolves the so-called top-down/bottom-up dichotomy. The private medical sub-sector exerts economic, ideological and political influences on the public health service. Compulsory health insurance schemes can have some similar effects. Success of a PHC policy requires that governments adopt a holistic approach to the health sector. The allocation of health care resources on the bases of need and equity, as opposed to demand, is a political decision. The establishment of a national PHC policy backed up by adequate resources involves a specific politico-technical exercise with four components: research, planning, policy formulation, and government policy decision-making. The resource planning method, based on social epidemiology, is contrasted with conventional health planning methods, based on epidemiology. The articulation of these two approaches is discussed in terms of WHO's Managerial Process for National Health Development.

Costs and Cost Analysis↗
PubMed1983

The effect of mismatching for HLA-DR in recipients of renal allografts sharing one HLA-ABC haplotype with related donors.

The effects of mismatching for DR antigens on renal allograft survival rates have largely been restricted to analyses of cadaver transplant results. Analyses of HLA matching in recipients of transplants from related donors have focused on the number of haplotypes shared between the recipients without regard to DR, or on the total number of HLA antigens mismatched, or on the degree of MLC responsiveness of the recipient to the donor. Most related donor-recipient pairs sharing only one HLA haplotype will be mismatched for DR at the other haplotype, but because there are a limited number of DR alleles, sharing of DR antigens on the mismatched haplotypes occurs relatively frequently. To determine the influence of mismatching for DR on the fate of renal allografts from related donors, we analyzed the results of 172 kidney transplants from related donors who shared one HLA-ABC haplotype with the recipient. There were 156 primary grafts and 16 retransplants; 147 donor-recipient pairs were satisfactory typed for DR antigens. Because genotyping was not usually done, we performed two analyses under two different assumptions. The first assumption was that individuals expressing less than or equal to 1 DR antigen had null antigens, or were homozygous for DR; the alternative assumption was that blanks were true antigens and individuals with blanks were heterozygous. The first assumption is more likely to be correct, and is the assumption used in most analyses of the effect of DR antigen mismatches on the results of cadaveric transplantation. Under the first assumption, of the 147 related donor-recipient pairs in whom DR typing was satisfactory, 33% were mismatched for 0, 64% for 1, and 3% for 2 DR antigens. The one-year absolute graft survival rates in recipients of kidneys from donors with 0 mismatches for DR was 92% (n = 49); in those with one mismatch for DR it was 82% (n = 94); and from those with two mismatches it was 50% (n = 4). The one-year graft survival rate in 25 donor-recipient pairs in which one or both members could not be satisfactorily DR typed was 76%. Differences in graft survival rates between the 0 and 1 and the 1 and 2 DR-mismatched groups were not statistically significant.(ABSTRACT TRUNCATED AT 400 WORDS)

Graft Rejection↗
PubMed1983

On the concept of a socialist health system: a question of Marxist epistemology.

This paper concerns the best approach to the concept of a socialist health system. It first criticizes a narrow empiricism, which reduces the subject to a phenomenalistic study of existing health systems in socialist countries, paying insufficient attention to historical contexts and developments and to the worldwide evolution of socialist ideas. Such a rightist empiricism, separating practice from theory, is then contrasted with a leftist idealism, which separates theory from practice. The latter approach entails abstract models of an ideal socialist health system with many characteristics, without specifying which are the necessary and sufficient ones for applying the global designation "socialist." This leads to epistemological confusion and a deterministic view of the relation of the social formation to the health system, which is in fact complex. A socialist health system is best seen as an aspect of socialist theory rather than as an actual social entity. Viewed this way, it can act as a continuing guide to social practice and be enriched by that practice. Taking an appropriate class standpoint, socialist health theory should relate to social factors in the causation of disease and in the capacity of peoples to undertake health-related activities and to the social control of health care services and related industries.

Communism↗
PubMed1983

Dissociation in expression of MB1/MT1 and DR1 alloantigens in mutants of a lymphoblastoid cell line.

Cytotoxicity tests with alloantisera were used to study the expression of HLA-D region antigens in HLA-DR-null mutants of a human lymphoblastoid cell line. The initial cell line contained just one copy of the MHC as a haplotype that included DR1 and MB1/MT1. Gamma ray mutagenesis of the single haplotype cells followed by selection with complement and an anti-DR monoclonal antibody were then used to isolate DR-null mutants. Two categories of mutants were identified with a panel of alloantisera. Expressions of DR1 and MB1/MT1 were simultaneously lost in four mutants. Nine mutants still expressed MB1/MT1 but had lost the expression of DR1. The dissociated loss of expression of MB1/MT1 and DR1 antigens is evidence for separate genetic control of these alloantigens. The methods used exemplify a versatile approach for conveniently inducing separations of closely linked loci of the MHC.

Cell Line↗
PubMed1982

HLA and susceptibility to type I diabetes. Hypothesis.

Positive associations between the antigens D(R)3 and D(R)4 and negative associations of D(R)2 have been reported with insulin dependent or type I diabetes mellitus. It has been suggested that susceptibility factor(s) associated with the D(R)3 and D(R)4 haplotypes and a resistance factor associated with the D(R)2 haplotype may be involved in the pathogenesis of the disease. We propose a hypothesis herein which attempts to unify these findings based on our present understanding suggesting (a) the existence of multiple antigenic determinants associated with any one D(R) haplotype and (b) the sharing of "single" D region encoded determinants between what we now refer to as different D(R) haplotypes. The hypothesis, in its simplest form, focuses on a single D region determinant which can be found associated at different frequencies with the various D haplotypes as potentially explaining the findings.

Diabetes Mellitus↗
PubMed1980

Cloned primed-lymphocyte-test reagents in the dissection of HLA-D.

Human T lymphocytes obtained as blasts on day 4 from a primary mixed leukocyte culture (MLC) were cloned in the presence of T cell growth factor (TCGF) and feeder cells. Parameters important in producing higher-specific-activity TCGF were evaluated; irradiation of the responding cells as well as removal of adherent cells or inclusion of indomethacin in the culture was important. In addition, the presence of an irradiated lymphoblastoid cell line (LCL) cell in the TCGF-producing system enhanced activity in the supernate. The long-term maintenance of progeny from clones was achieved by utilizing the LCL autologous with either the responding or sensitizing cells from the initial MLC as feeder cells. Under those conditions, clones could be expanded for 7 or more wk with the maintenance of PLT reactivity. Had all the cells in each clone been maintained for the full 7 wk, more than 1 X 10(10) cells could have been developed in each clone. The cloned reagents provide a higher degree of antigen-specific reactivity than do normal PLT cells. It is to be anticipated that as the requirements for cloning are made more stringent, including the recloning of the cells, these reagents will aid greatly in the dissection of the complexity attendant to HLA-D.

Clone Cells↗
PubMed1980

Complexity of the HLA-D region studied by primed-lymphocyte test.

The results obtained by mixed lymphocyte culture (MLC), HLA-D and -DR typing, and primed lymphocyte test (PLT) in the F. family give some indication of the complexity of the HLA-D region in man. Two siblings identical for HLA-A, -B, -C, -D, and -DR by typing are mutually MLC-stimulatory. PLT studies indicate that one of these siblings expresses D-region determinants of both of the mother's haplo-types, suggesting an intra-D recombinant. These results suggest that the D region contains genes for a number of different determinants.

Epitopes↗
PubMed1980

Vascular tufts in retrolental fibroplasia.

Three cases of retrolental fibroplasia with vascular tufts at different locations are described. They probably represent mesenchymal proliferation in response to severe hypoxia. The tufts are reddish-pink in color and angiographically do not leak fluorescein. When present posterior to the equator they suggest an immature retinal circulation and the visual prognosis is poor.

Adolescent↗
PubMed1980

Rubella maculopathy.

Three patients with known history of congenital rubella and sudden decrease of vision are presented. Two of the 3 patients had previous eye examinations which showed typical rubella (salt and pepper) retinopathy. All 3 showed macular lesions associated with presumed subretinal neovascularisation.

Child↗
PubMed1979

Increased frequencies of aberrant sperm as indicators of mutagenic damage in mice.

We have tested the effects of TEM in 3 strains of mice using the sperm morphology assay. In addition, we have made an attempt to evaluate this test system with respect to experimental design, statistical problems and possible interlaboratory differences. Treatment with TEM results in significant increases in the percent of abnormally shaped sperm. These increases are readily detectable in sperm treated as spermatocytes and spermatogonial stages. Our data indicate possible problems associated with inter-laboratory variation in slide analysis. We have found that despite the introduction of such sources of variation, our data were consistent with respect to the effects of TEM. Another area of concern in the sperm morphology test is the presence of "outlier" animals. In our study, such animals comprised 4% of the total number of animals considered. Statistical analysis of the slides from these animals have shown that this problem can be dealt with and that when recognized as such, "outliers" do not effect the outcome of the sperm morphology assay.

Animals↗
PubMed1977

Mixed leukocyte culture incompatibility index for donor-recipient selection in kidney transplantation.

The mixed leukocyte culture test has been applied to selection of histocompatibility non-identical donor-recipient pairs for renal transplantation. The clinical course of transplant recipients who have histocompatibility mismatches but low mixed leukocyte culture stimulation is similar to that of mixed leukocyte culture and histocompatibility identical recipients. Living donor-recipient pairs with high mixed leukocyte culture stimulation had no better graft survival than cadaver recipients. An incompatibility index derived from mixed leukocyte culture may aid in the selection of satisfactory non-identical living related donors and may help avoid use of immunologically unsatisfactory living donors.

Cadaver↗