Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eighteen unrelated Chinese patients with insulin-dependent diabetes mellitus (IDDM) were analyzed for HLA Class II genes using a variety of molecular biological techniques including restriction fragment length polymorphism (RFLP), polymerase chain reaction with allele-specific oligonucleotides (PCR-ASO) and direct DNA sequencing. The high frequency of DR3/DR4 heterozygotes found in the Chinese with IDDM strengthens the importance of this combination of haplotypes in IDDM susceptibility since it is present in two genetically distant populations--Chinese and Caucasians. The frequency of DRw9, a rare allele in the Caucasian population, is much higher in the Chinese. Moreover, the DQ beta chain linkage of DRw9 was different in IDDM patients compared with control subjects. In contrast with previous results, codon 57 of the DQ beta chain was aspartic acid in DRw9 Chinese IDDM patients. Furthermore, one particular DRw9-DQw9 haplotype may be associated with IDDM susceptibility in the Chinese population.
 ...
PMID:Aspartic acid at position 57 of the HLA-DQ beta chain in insulin-dependent diabetes mellitus: an association with one DRw9-DQw9 subtype in the Chinese population. 180 12

HLA Class II polymorphisms were analysed in 27 families with at least one Type I diabetic proband using Southern blotting technique according to 10th Histocompatibility Workshop Standards. The probes used were DRB, DQA1, DQB1 and DOB. We have studied 108 haplotypes and performed segregation analysis with HLA serology and restriction fragment length polymorphism (RFLP) data and compared "affected" with "non-affected" haplotypes (not inherited by IDDM patients). RFLPs correlated well with DR and DQ serology and detected additional polymorphisms. In particular, DQB polymorphism analysis showed segregation of the DQw3 splits with 88.5% of the DR4 affected haplotypes bearing the DQw3.2 split (now DQw8) and 11.5% the DQw3.1 split (now DQw7) while in the non-affected DR4 haplotypes 33.3% were DQw3.2 and 66.6% were DQw3.1. Haplotype analysis showed that DR4-DQw3.2 was in strong linkage with the U fragment (2.1 kb Taq I) of DQA2 (DX alpha) and with the L fragment (5.4 kb BamH I) of DOB. This study confirms previous observations of DQB polymorphisms in heterozygous IDDM patients, supports the protective effect of DQw3.1 (DQw7) against the development of the disease and demonstrates the importance of DQw3.2 (DQw8) for susceptibility to Type I diabetes.
 ...
PMID:Restriction fragment length polymorphism analysis of HLA haplotypes in families with type I diabetes mellitus. 196 92

There is evidence that certain alleles at the HLA-DQ locus are correlated with susceptibility to insulin-dependent diabetes mellitus (IDDM) and in particular that DQ beta-chain alleles containing aspartic acid at position 57 are protective. The availability of a large group of patients with IDDM enabled us to assess the role of HLA-DQ alleles in susceptibility to the disease in order to confirm and extend recent observations derived from studies of smaller numbers of patients. Using allele-specific oligonucleotide probes and the polymerase chain reaction, we studied 266 unrelated patients with IDDM and 203 unrelated normal subjects for eight HLA-DQ beta-chain alleles. Two major findings emerged from these studies. First, the presence of an HLA-DQw1.2 allele was protective. Only 6 of the 266 patients with IDDM (2.3 percent) were positive for HLA-DQw1.2, as compared with 74 of the 203 normal subjects (36.4 percent; P less than 0.001). Thus, persons with the HLA-DQw1.2 allele, which is one of the polymorphic forms of the beta chain of the HLA-DQ molecule, rarely had IDDM, no matter which other HLA-DQ beta-chain allele they inherited ("dominant protection"). Second, the presence of the HLA-DQw8 allele increased the risk of IDDM. The relative risk of IDDM was 5.6 in persons homozygous for HLA-DQw8, and it was similar in persons with the HLA-DQw1.1/DQw8 or HLA-DQw2/DQw8 haplotype ("dominant susceptibility"). However, the relative risk of IDDM in persons who had the HLA-DQw1.2/DQw8 haplotype was 0.37, demonstrating that the protective effect of HLA-DQw1.2 predominated over the effect of HLA-DQw8. We conclude that the presence of the HLA Class II antigen DQw1.2 is strongly protective against the development of IDDM, and that complete HLA-DQ typing is necessary for accurate assessment of susceptibility to IDDM.
 ...
PMID:Analysis of HLA-DQ genotypes and susceptibility in insulin-dependent diabetes mellitus. 234 40

Over a period of 5 years, lymphocyte subpopulations and their markers of activation were studied prospectively in 56 first degree relatives of Type 1 (insulin-dependent) diabetic probands. Lymphocytes were phenotyped using a panel of monoclonal antibodies which recognise CD3, CD4, CD8 lymphocytes, K/NK cells, HLA Class II products and IL-2 receptors (IL-2r). Twenty-six subjects were negative for islet cell antibody (ICA), 18 had complement fixing ICA (CF-ICA) and 12 only conventional ICA (ICA-IgG). The total number of observations (blood samples collected) was 386. Overall, changes in T cell data were observed in the three groups of first degree relatives compared to 70 normal subjects without a family history of diabetes. Six individuals developed Type 1 diabetes in the course of the study. They all possessed CF-ICA and five out of six showed a persistent reduction (less than 1.5) of the CD4/CD8 lymphocyte ratio before the clinical onset of the disease. Activated lymphocytes were found on two occasions in two of these subjects. We conclude that imbalance of lymphocyte immunoregulatory subsets is present before the onset of Type 1 diabetes in susceptible individuals; the persistence of a reduced CD4/CD8 lymphocyte ratio may reflect the ongoing process leading to B-cell destruction.
 ...
PMID:Persistent reduction of CD4/CD8 lymphocyte ratio and cell activation before the onset of type 1 (insulin-dependent) diabetes. 250 62

The majority of the genetic component in insulin dependent (Type 1) diabetes mellitus can be explained by associations with genes on short arm of chromosome 6 located in the major histocompatibility complex. With the advent of cloning of the HLA Class II region genes it has been possible to refine the previous known association of HLA-DR3 and DR4 with this disease. Strong associations of IDDM have now been shown to exist with the DQB1 gene and/or linked genes, although this does not completely explain the HLA susceptibility to this disease.
 ...
PMID:The major histocompatibility complex and insulin dependent (type 1) diabetes. 257 93

Physiologically, HLA Class II molecules are primarily expressed on immunoregulatory cells. In recent years, it has been shown that tissues affected by autoimmunity, including beta cells of 'diabetic' pancreases, 'inappropriately' express these glycoproteins. Cytokines are potent Class II inducers on a variety of cells but they exert a heterogenous effect when incubated with different human endocrine cells, i.e. thyroid cells are readily inducible, beta cells are much more resistant. The fine modulation of Class II expression by cytokines has been extensively studied and recent information on their action on endocrine cells is reported here. The possibility that distinct environmental factors from those postulated until now may be responsible for triggering the inappropriate expression of MHC molecules in epithelial cells in vivo is also emphasized. Despite several similarities between human Type I diabetes and spontaneous animal models of the disease, major differences still exist. Transgenic models have now been produced. However, even if they offer interesting new insights, they have not so far provided the decisive answer to explain the pathogenesis of human autoimmune diseases.
 ...
PMID:Inappropriate expression of HLA class II molecules in endocrine epithelial cells: the phenomenon, the new experimental data and comparison with animal models. 267 70

HLA Class II serological and DQ beta restriction fragment length polymorphisms (RFLPs) were compared in 69 patients with insulin-dependent diabetes mellitus (IDDM) and 81 healthy British Caucasoid controls. The backbone of the analysis was formed by two Taq 1 RFLPs of the DQ beta region designated T2 omega and T6. The two are not allelic and can be inherited individually, together on one, or separately on both, parental haplotypes, the latter almost invariably in association with DR4. In our study the frequency in IDDM patients of both T2 omega and T6 together (relative risk for IDDM = 6.4) is similar to that of DR3/DR4 (relative risk for IDDM = 5.4) with an even higher relative risk for IDDM when they are combined, (relative risk = 18 with 95 per cent confidence limits between 14 and 22). We have thus defined DQ beta RFLPs which tightly associate with IDDM individuals with DR4.
 ...
PMID:DQ beta restriction fragment length polymorphism and its relationship to insulin dependent diabetes mellitus. 290 34

The normally functioning immune system is subject to intricate networks of regulatory mechanisms: it is therefore not surprising to find that autoimmune diseases present a complex pathogenic picture in which the relative contributions of various factors probably determine the precise nature and course of disease. This is particularly evident in the effector mechanisms of organ-specific autoimmunity which are described in this chapter. These ultimately give rise to the disease symptoms, and can be directly cytotoxic, or may either stimulate or block functional activity or growth of the target cells. Their various contributions to human diseases are becoming more firmly established, as in Type I diabetes, or are only now being described, as in the case of EC-Ab in protracted diarrhea of infancy and as evidenced by the growing lists of receptor-stimulating or -blocking antibodies. The nature and precise location of relevant autoantigens is also coming under closer scrutiny. The answers to the question of why these diseases arise in the first place remain more elusive. However, it is again likely that a variety of factors can contribute. The attractive possibility of a role for idiotypic interactions is gaining ground, particularly within the context of antibodies to hormones and their receptors. Another potential mechanism which we believe may be of central importance, particularly in the development of organ-specific destructive autoimmunity, and which we have discussed here in detail, is the aberrant expression of HLA Class II molecules by target cells. Whether this is actually an initiating factor is presently not known, but its potential for promoting pathogenesis both early and late in the process is clear. Furthermore, the complex nature of the regulation of epithelial Class II expression may help to explain the heterogeneity of features and course of disease in different patients with the same underlying pathology. All these advances in our basic understanding of the disease processes should ultimately lead to more effective and specific means of therapeutic intervention.
 ...
PMID:Organ-specific autoimmunity: a 1986 overview. 302 54

Inappropriate expression of HLA Class II (D/DR) molecules has been detected in the target cells of most autoimmune diseases including Type I (insulin-dependent) diabetes. The possibility that this phenomenon is due to the action of lymphocytes or some of their products has been investigated by analysing in vitro the modulation of HLA products in Beta cells. Monolayer cultures from 25 human pancreatic glands were supplemented with alpha-interferon (IFN), beta-IFN or gamma-IFN, interleukin 2 (IL-2) and supernatants from activated lymphocytes. In addition, lectins and a variety of other hormones, biological products and chemicals were tested. Major histocompatibility complex (MHC) expression was assessed by double immunofluorescence technique using monoclonal antibodies to non-polymorphic determinants of Class I and Class II molecules and the pancreatic cells were identified by antibodies to islet hormones and other cytoplasmic antigens. gamma-IFN and lectins produced a parallel enhancement of HLA-A,B,C expression in islet, exocrine/ductal cells and fibroblasts. HLA-D/DR was inducible in all pancreatic cell types, except endocrine islet cells which did not produce Class II molecules in response to any of the stimuli including supernatants from activated lymphocytes. Exocrine/ductal cells from glands of patients with chronic pancreatitis spontaneously expressed Class II products, but islet cells were devoid of any detectable D/DR. These data are consistent with recent observations which have indicated that in the 'diabetic' pancreas inappropriate Class II expression in the Beta cells occurs independently of the presence of lymphocytes infiltrating the islets, and make it necessary to postulate that other factors are responsible for the Class II induction in Beta cells in human Type I diabetes.
 ...
PMID:Differential expression and regulation of MHC products in the endocrine and exocrine cells of the human pancreas. 309 71

By the end of March, 1987, 550 couples had been enrolled in the Habitual Miscarriage Outpatient Department at Keio University Hospital in Japan. The average rate of miscarriages during the past 8 years at this hospital was 16.12%. Average number of miscarriages suffered by those couples was 3.09 +- 1.13. Average age of the husband was 34.5 +- 0.3, and that of the wife was 32.8 +- 0.3. All of those who miscarried 2 or 3 times underwent thorough clinical tests. The results showed organic disorders such as uterine myoma (22), arched uterus (16), cervical incompetency (14), double uterus (9), endocrine abnormalities such as hyperthyroidism (6) and hypothyroidism (7), metabolic disorders such as diabetes, rheumatism, and chromosomal abnormality (15/252). In HLA Class II typing, DR antibody was commonly possessed by many couples who had habitual miscarriages. Testings of reproductive wastages both at fertilization and nidation did not yield significant results because of defective methods. Surgical removal of uterine myoma, plastic unification of double uterus, and immunological therapy were among the methods used for treating infertility. Immunotherapy used at Keio University Hospital is as follows: 30 ml venum is taken from the husband aseptically; lymphocyte is isolated from the venum via Ficoll conray; its concentration is adjusted to 3.0-4.0X107/ml; intracutaneous injection of it is given to his wife every 2 - 4 weeks. This therapy resulted in 96 cases of pregnancy among 150 couples. 3 year follow-up study on 42 births show that those babies are healthy and normal in every respect.
 ...
PMID:[Comprehensive examination and treatment on reproductive wastage]. 330 74


1 2 Next >>