Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As dendritic antigen-presenting cells in skin and mucous membranes, Langerhans cells (LC) are found in areas at risk of inoculation by the human immunodeficiency virus (HIV). LC have been reported as targets for HIV-1. The aim of the present study was to investigate whether LC can be experimentally infected by HIV provided by a cell-free infection system. A cell-free suspensions was prepared from viral particles provided by chronically infected cell lines (U937 or H9 cells) by low-speed centrifugation followed by 0.45-microns filtration. LC-enriched epidermal cell (EC) suspensions with no CD3+ cells (assessed by flow cytometry and electron microscopy) and uninfected U937 cells (cell-free infection system control) were infected with two isolates (HTL VIII-B and RF). The infectiousness of the cell-free virus fluids was controlled on U937 cells where proviral DNA was amplified (gag, pol, and env gene sequences by the polymerase chain reaction, PCR) and release of virus particles into the supernatant was controlled either by measure of the reverse transcriptase (RT) activity or detection of viral RNA amplified by RT-PCR for the gag gene sequences). Proviral DNA (gag gene sequences) was found in LC-enriched epidermal cellular DNA from day 4 post-infection with isolate HTL VIII-B and from day 7 with isolate RF. Although the RT activity did not reach a significantly high level, viral RNA was found in the supernatant of LC-enriched EC cultures at the same time as proviral DNA was detected in LC.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Detection of HIV-specific DNA sequences in epidermal Langerhans cells infected in vitro by means of a cell-free system. 772 34

Hemophilia A is caused by a deficiency of factor-VIII procoagulant (fVIII) activity. The current treatment by frequent infusions of plasma-derived fVIII concentrates is very effective but has the risk of transmittance of blood-borne viruses (human immunodeficiency virus [HIV], hepatitis viruses). Use of recombinant DNA-derived fVIII as well as gene therapy could make hemophilia treatment independent of blood-derived products. So far, the problematic production of the fVIII protein and the low titers of the fVIII retrovirus stocks have prevented preclinical trials of gene therapy for hemophilia A in large-animal models. We have initiated a study of the mechanisms that oppose efficient fVIII synthesis. We have established that fVIII cDNA contains sequences that dominantly inhibit its own expression from retroviral as well as from plasmid vectors. The inhibition is not caused by instability of the fVIII mRNA (t1/2, > or = 6 hours) but rather to repression at the level of transcription. A 305-bp fragment is identified that is involved in but not sufficient for repression. This fragment does not overlap the region recently identified by Lynch et al (Hum Gene Ther 4:259, 1993) as a dominant inhibitor of RNA accumulation. The repression is mediated by a cellular factor (or factors) and is independent of the orientation of the element in the transcription unit, giving the repressor element the hallmarks of a transcriptional silencer.
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PMID:Expression of the blood-clotting factor-VIII cDNA is repressed by a transcriptional silencer located in its coding region. 772 75

Three examples of human plasma-derived concentrates, intermediate-purity factors VIII and IX, and fibrinogen were spiked with tissue culture-grown human immunodeficiency virus type 1 (HIV-1) strain RF. All examples were freeze-dried and heated at 80 degrees C for 72 hours by using validated production process models. HIV-1 infectivity was measured by a syncytial infectivity assay in C8166 cells and then compared with levels determined by nested HIV polymerase chain reaction (PCR). The infectivity assay demonstrated a reduction index of at least 4.5 log10, while PCR showed an average 1.7 log10. Large amounts of HIV-1 RNA (10(5)) were still detectable by PCR in samples in which infectivity assays failed to detect any HIV-1. These data suggest that HIV-1 PCR levels do not parallel HIV-1 infectivity levels during virus-inactivation procedures involved in coagulation factor concentrate production. PCR was able to detect the RNA associated with inactivated HIV-1 particles in the factor concentrates, which allows the conclusion that PCR is not a useful test with which to monitor virus-inactivation procedures such as heating at 80 degrees C for 72 hours. This judgment contrasts with the more definite and sensitive role of PCR in diagnosing HIV-1 infection in patients in whom a positive HIV-1 PCR result correlates with active HIV-1 infection and with PCR's usefulness in monitoring virus removal.
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PMID:A comparison of polymerase chain reaction and an infectivity assay for human immunodeficiency virus type 1 titration during virus inactivation of blood components. 823 26

Virucidal methods to inactivate infectious agents are based on various methods of heating or chemically treating plasma concentrates of coagulation factors VIII and IX used in the treatment of hemophilia A and B. This clinical evaluation of the viral safety of such 'treated' concentrates is mainly based on the prospective study of previously untreated hemophiliacs by means of clinical and serological markers of viral infection. Although there have been a few focal episodes of human immunodeficiency virus (HIV) transmission by clotting factors, these have been traced to ineffective virucidal methods that are no longer used or to clerical errors during the manufacturing process. Viral inactivation by pasteurization, vapor heating, heating in the lyophilized state at 80 degrees C and addition of solvent/detergent definitely decreases the risk of infection with hepatitis B and C. The current screening of plasma units for antibody to hepatitis C virus prior to inclusion in pools for concentrate production should further decrease the risk of hepatitis C infection. Other viruses, such as parvovirus and the hepatitis A virus, may still cause infections because they are quite resistant to virucidal methods. On the whole, virucidal methods have greatly reduced the risk of new HIV infections and, to a lesser degree, hepatitis.
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PMID:Clinical evaluation of viral safety of coagulation factor VIII and IX concentrates. 803 99

Synthetic peptide antigens corresponding to the entire third variable region V3, the principal neutralizing determinant of the human immunodeficiency virus (HIV) envelope glycoprotein of HIV-1 subtype B (1), HIV-2 subtype A (5), and HIV-2 subtype B (7) were synthesized by solid-phase peptide synthesis (Table 1). 1 and 5 were also prepared as their GlcNAc-glycosylated forms at the natural N-glycosylation site NXT (positions 6-8; peptides 4 and 6). Additionally, the proposed beta-turn region of 1 (GPGR; positions 15-18) was altered by introducing D-Ala17 (2) and D-Pro16 (3). All compounds have been studied by two-dimensional NMR techniques. Interproton distances and 3JNH/H alpha coupling constants derived from NMR data are used as restraints in distance geometry and ENSEMBLE-Distance and angle-bound driven dynamics calculations. The stimulations led to disordered conformations except for a high propensity of a beta II-turn in the region GPXR (positions 15-18) in 1, 2, and 4. In 3 (G-D-ProGR, positions 15-18), a type beta I'-turn was mainly found instead. For peptide 7, the consensus sequence of HIV-2 subtype B, a type beta II-turn was also found although the primary structure (VSGL; positions 15-18) differs grossly from the HIV-1 peptide 1. With the exception of 2, all beta II-turns were able to form a canonically opened beta-turn by a 180 degree rotation of phi(G17). Surprisingly, compounds 5 and 6 that are highly similar to 7 showed no beta II-type turn within MSGL (positions 15-18). They form a type beta VIII-turn across the tetrapeptide SGLV (positions 16-19) together with a non-canonical turn conformation across LMSG (positions 14-17) leading to an S-conformation. The reaction of the peptides with HIV-positive sera from patients infected with different subtypes of HIV-1 and HIV-2 was tested in enzyme-linked immunosorbent assays (ELISA reactions). No HIV-2 sera reacted peptide 1 and no HIV-1 sera showed reactivity to peptide 5. We propose that certain amino acid exchanges within the V3 domain lead to altered conformations of the V3 loop resulting in antibodies that show altered binding properties to the peptide antigens used in the ELISA reactions.
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PMID:Secondary structural elements as a basis for antibody recognition in the immunodominant region of human immunodeficiency viruses 1 and 2. 862 Aug 73

Ten patients with asymptomatic human immunodeficiency virus (HIV) infection were treated for typhoid fever at King Edward VIII Hospital, Durban, South Africa, from 1993 through 1995. The mean age was 23.7 years (range, 8-33 years), with a female-to-male ratio of 9 to 1 and mortality and morbidity rates of 20% and 10%, respectively. Common presenting manifestations were fever (100%), relative bradycardia (50%), and diarrhea (40%). With respect to epidemiologic and clinical characteristics, we noted no significant differences among these 10 HIV-positive and 32 HIV-negative patients treated for typhoid fever during the same period. However, we found hepatic dysfunction in the form of an isolated increase in aspartate aminotransferase (p < 0.01) and abnormal urinary findings suggestive of glomerulonephritis (p = 0.01) more frequently in HIV-positive patients.
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PMID:Typhoid fever and asymptomatic human immunodeficiency virus infection. A report of 10 cases. 941 66

Cells with fibroblast-like features were isolated from the villous tissue of normal term human placentas. Immunocytochemical characterization of the cells showed that they were vimentin-positive but negative for factor-VIII, CD14 and CD4. Thus, the cells are mesenchymal and are not endothelial cells, macrophages or trophoblast. These cells were exposed to nine different cell-free virus isolates, including seven isolates of human immunodeficiency virus type 1 (HIV-1), one HIV-2 isolate and one simian immunodeficiency virus isolate (SIVmac251). The susceptibility of the cells to infection was evaluated by immunocytochemical and virological techniques. No evidence of infection could be found using immunofluorescence microscopy or by p24 antigen capture and reverse transcriptase assays. However, virus rescue experiments using 11 different target cell types provided evidence that the placental fibroblasts were susceptible to infection with HIV-1Lai, HIV-1IIIB, HIV-2CBL-20, and SIVmac251, yet were resistant to infection by all other isolates. The infected fibroblasts exhibited neither cytopathic effects nor released virus into the culture medium. For each infected fibroblast population, some, but not all, indicator target cell lines or human peripheral blood mononuclear cells were able to rescue the respective virus. Based on these observations, we conclude that placental fibroblasts can be infected with HIV during transplacental transmission and could act as virus reservoirs, capable of infecting other fetal cells.
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PMID:Infection of primary human placental fibroblasts with HIV-1, HIV-2, and SIV. 967 89

A prospective observational study over a 6-month period on women presenting with infertility was conducted at King Edward VIII Hospital (KEH), South Africa. The aim of the study was to establish the patient profile and investigations performed on women presenting with infertility. One hundred women were recruited. The mean age of the women was 31 years and 60% had secondary infertility. The mean duration of infertility was 7.2 years; 61% had histories suggestive of pelvic inflammatory disease and approximately half (49%), had had previous infertility investigations; 16% of the women were HIV (human immunodeficiency virus) antibody positive and 16% had positive syphilis serology. Tubal factors were identifiable in 77%, ovulatory factors in 21% and uterine factors in 21%. Male factor infertility was present in 21%. The study confirms that in developing countries, tubal factors are the commonest cause of infertility.
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PMID:Infertility profile at King Edward VIII Hospital, Durban, South Africa. 970 Feb 83

Known since the beginning of the first millenium, the hemophilias are among the most frequent inherited disorders of blood coagulation and definitely the most severe. In the 1970s, with the availability of concentrated preparations of the deficient coagulation factors VIII and IX and with the large-scale adoption of home treatment, hemophilia care became one of the most gratifying examples of successful secondary prevention of a chronic disease. Unfortunately, in the early 1980s It was recognized that factor concentrates prepared from plasma pooled from thousands of donors transmitted the hepatitis and the human immunodeficiency viruses. The scientific community reacted promptly to the devastation brought about by hepatitis and AIDS. The last 15 years of the second millenium have witnessed the development of methods that applied during concentrate manufacturing inactivate viruses escaping the screening procedures. The adoption of these measures has reduced dramatically the risk of transmission of bloodborne infections. The production of recombinant factors and their availability for patient treatment epitomize progress in hemophilia care through DNA technology. Methods based on the polymerase chain reaction (PCR) have unraveled an array of gene lesions associated with hemophilia, permitting improved secondary control of the disease through carrier detection in women from affected families and prenatal termination of their affected male infants. This article will review the aforementioned areas of progress and discuss unresolved problems (such as treatment of patients with antibodies, the risk of new infectious complications, and the issue of secondary tumors). Hopes and expectations for further improvement in the third millenium and particularly the prospects of hemophilia cure through gene replacement therapy will also be mentioned.
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PMID:The hemophilias: progress and problems. 1059 59

Lentiviral vectors have the potential to play an important role in hemophilia gene therapy. The present study used human immunodeficiency virus (HIV)-based lentiviral vectors containing an EF1alpha enhancer/promoter driving human factors VIII (hFVIII) or IX (hFIX) complementary DNA expression for portal vein injection into C57Bl/6 mice. Increasing doses of hFIX-expressing lentivirus resulted in a dose-dependent, sustained increase in serum hFIX levels up to approximately 50-60 ng/mL. Partial hepatectomy resulted in a 4- to 6-fold increase (P < 0.005) in serum hFIX of up to 350 ng/mL compared with the nonhepatectomized counterparts. The expression of plasma hFVIII reached 30 ng/mL (15% of normal) but was transient as the plasma levels fell concomitant with the formation of anti-hFVIII antibodies. However, hFVIII levels were persistent in immunodeficient C57Bl/6 scid mice, suggesting humoral immunity-limited gene expression in immunocompetent mice. This study demonstrates that lentiviral vectors can produce therapeutic levels of coagulation factors in vivo, which can be enhanced with hepatocellular proliferation.
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PMID:Therapeutic levels of human factor VIII and IX using HIV-1-based lentiviral vectors in mouse liver. 1091 Sep 39


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