Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001175 (AIDS)
 120,706 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Blood coagulation factor IX (Christmas factor) is a plasma protein which is required for normal haemostasis. A functional deficiency of factor IX results in haemophilia B, a bleeding disorder which is generally treated by infusions of factor IX concentrates prepared from pooled human plasma. The use of human blood products is connected with the risk of transmitting viral agents responsible for diseases such as hepatitis B and AIDS. Recombinant DNA techniques may provide the means to produce the required proteins without exposing the patients to these risks and at lower costs. One of the problems which has to be overcome before recombinant factor IX can be used for therapeutical purposes is related to the vitamin K-dependent carboxylation of its 12 NH2-terminal glutamate residues. In cell cultures this carboxylation, which is required to render the protein its procoagulant activity, is far from complete, especially at high expression levels. In this paper we describe the in vitro carboxylation of non and/or partly carboxylated recombinant factor IX produced by transformed Chinese hamster ovary cells. The identity of the newly formed Gla residues was verified and it could be demonstrated that all carboxyl groups had been incorporated into the recombinant factor IX.
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PMID:In vitro carboxylation of a blood coagulation factor IX precursor produced by recombinant-DNA technology. 274 97

Hemophilia is an inherited hemorrhagic disease which is due to the insufficiency of Factor VIII, or Factor IX, or Factor XI. Hemophilia patients are regarded as special patients with increased dental problems. The present paper consists of two parts. In the first part the types of hemophilia, ways of transmission, severity forms, and clinical characteristics are described. In the second part a protocol concerning the dental treatment of hemophilia patients is presented. There are four basic types of hemophilia: hemophilia A or classical hemophilia or Factor VIII deficiency, hemophilia B or Christmas disease, hemophilia C and von Willebrand's disease. Hemophilia is transmitted either as a sex-linked recessive or as an autosomal dominant trait, depending on the type of the disease. The severity of hemophilia depends on the amount of the coagulation factor present. According to this amount, there are four scales of severity. The clinical characteristics of the disease also depend on the amount of the factor present and vary, from occasional bleedings to serious and even life-threatening bleeding episodes. In the second part of the paper the special psychological and physiological problems of the hemophiliacs are discussed. In addition, there is reference to the hematologic coverage these patients need, as well as to the protection measures for the dental personnel against hepatitis and AIDS. The dental treatment plan at the office is presented in detail, including a discussion of the advantages and disadvantages of the treatment of hemophilia patients in the operating room under general anesthesia.
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PMID:[Hemophilic patients. Treatment protocol in the dental office]. 297 76

Approximately 1% of all AIDS cases are haemophiliacs. LAV/HTLV-III is transmitted by blood and in factor VIII concentrates. Since 1981, increasing numbers of haemophiliacs have been infected, as indicated by detection of antibodies to LAV/HTLV-III. Up to 90% of haemophiliacs in some populations are now seropositive, but to date less than 1% have progressed to clinical AIDS. Immunological abnormalities, in particular reduced T-lymphocyte helper/suppressor ratios, are common in haemophiliacs treated with factor VIII. Such abnormalities do not necessarily indicate past infection by the AIDS virus, but they may predispose to infection following exposure to the virus. Blood Transfusion agencies are introducing screening tests for antibodies to LAV/HTLV-III to help prevent the spread of AIDS by blood products. Heat treated factor VIII concentrate is now available and appears not to transmit AIDS. Factor IX concentrate may also transmit LAV/HTLV-III, but less frequently. A few cases of AIDS have occurred in Haemophilia B (Christmas Disease) patients.
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PMID:AIDS and haemophilia. 300 17

We compared recipients of eight lots of factors VIII and IX voluntarily withdrawn from distribution because one donor was known to have subsequently developed the acquired immunodeficiency syndrome with a nonexposed cohort matched by age, sex, and factor use. The factor VIII recipient cohorts did not differ in prevalence of antibody to human immunodeficiency virus (HIV) (exposed, 75%; nonexposed, 86%), T-cell subset numbers (median: exposed, 619 T-helper cells per cubic millimeter; nonexposed, 659 T-helper cells per cubic millimeter), T-helper to T-suppressor ratios, or immunoglobulin levels. Exposed individuals had higher levels of immune complexes by C1q binding and staphylococcal binding assays and lower responses to phytohemagglutinin and concanavalin A. However, only the staphylococcal binding assay values were outside the normal range for our laboratory. Factor IX recipient cohorts did not differ in HIV antibody prevalence (exposed, 30%; nonexposed, 40%) or any immune tests. Although exposed and nonexposed individuals did not differ from each other in a clinically meaningful fashion at initial testing, both the exposed and nonexposed cohorts had high rates of HIV seroprevalence. Market withdrawals were clearly insufficient means of limiting the spread of HIV in hemophilic patients; however, the currently available methods of donor screening and viral inactivation of blood products will prevent continued exposure within this population.
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PMID:Effects of exposure to factor concentrates containing donations from identified AIDS patients. A matched cohort study. 301 5

Factor IX is the precursor of a serine protease that functions in the intrinsic blood clotting pathway. Deficiencies in this plasma glycoprotein result in haemophilia B (or Christmas disease) and occur in about 1 in 30,000 males. Patients are currently treated with fresh frozen plasma or prothrombin complex concentrates prepared from pooled plasma from normal individuals. There are several problems with this method of treatment, including the probable exposure of the patients to contaminants such as the viral agents responsible for hepatitis and AIDS (acquired immune deficiency syndrome). As a first step towards an alternative source of pure human factor IX, we report here on the use of recombinant DNA techniques to produce biologically active factor IX in cultured mammalian cells. Stable cell lines were produced by cotransfecting a baby hamster kidney (BHK) cell line with a plasmid containing a gene for factor IX and a plasmid containing a selectable marker. Protein secreted by these cell lines reduces the clotting time of plasma from factor IX-deficient patients. We present additional evidence that this protein is authentic human factor IX.
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PMID:Expression of active human factor IX in transfected cells. 389 76

This study updates estimates of the cumulative incidence of AIDS among Italian patients with congenital coagulation disorders (mostly hemophiliacs), and elucidates the role of age at seroconversion, type and amount of replacement therapy, and HBV co-infection in progression. Information was collected both retrospectively and prospectively on 767 HIV-1 positive patients enrolled in the on-going national registry of patients with congenital coagulation disorders. The seroconversion date was estimated as the median point of each patient's seroconversion interval, under a Weibull distribution applied to the overall interval. The independence of factors associated to faster progression was assessed by multivariate analysis. The cumulative incidence of AIDS was estimated using the Kaplan-Meier survival analysis at 17.0% (95% CI = 14.1-19.9%) over an 8-year period for Italian hemophiliacs. Patients with age greater than or equal to 35 years exhibited the highest cumulative incidence of AIDS over the same time period, 32.5% (95% CI = 22.2-42.8%). Factor IX recipients (i.e. severe B hemophiliacs) had higher cumulative incidence of AIDS (23.3% vs 14.2%, p = 0.01) than factor VIII recipients (i.e. severe A hemophiliacs), as did severe A hemophiliacs on less-than-20,000 IU/yearly of plasma-derived clotting factor concentrates, as opposed to A hemophiliacs using an average of more than 20,000 IU (18.8% vs 10.9%, p = 0.02). No statistically significant difference in progression was observed between HBsAg-positive vs HBsAg-negative hemophiliacs (10.5% vs 16.4%, p = 0.10). Virological, immunological or both reasons can account for such findings, and should be investigated from the laboratory standpoint.
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PMID:Clinical factors associated with progression to AIDS in the Italian cohort of HIV-positive hemophiliacs. G.I.C.C. Gruppo Italiano Coagulopatie Congenite. 797 72

Evolution of HIV infection was studied in 480 hemophiliacs A and 78 hemophiliacs B treated in the "Centre-West" Region. 23.3% hemophiliacs A and 46.1% hemophiliacs B were contaminated by HIV. In this region, HIV seroprevalence in hemophiliacs A was lower than the prevalence noted at the national level (51.2%); this is certainly due to the use of frozen cryoprecipitates in the treatment of a high number of hemophiliacs A. A higher number of hemophiliacs B developed the disease: 12.5% hemophiliacs A versus 22% hemophiliacs B. Moreover hemophilic B patients had a more rapid evolution towards the disease since 6 out of 14 hemophiliacs A and 7 out of 8 hemophiliacs B with AIDS died. The fact that hemophiliacs B were significantly older than hemophiliacs A might be one of the reasons, but it must be noted that the contamination often occurred earlier in hemophiliacs B and was perhaps more important. The more severe evolution in the hemophiliac B group noted in our region is not found in American studies, which may be due to the different ways of preparing Factor IX concentrates in France and the United States.
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PMID:[HIV infection among type A and B hemophiliacs]. 825 52