Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0262471 (ENT)
 5,307 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study, one has determined the relative role of plasma membrane equilibrative (Na+-independent) ENT nucleoside transport proteins (particularly ENT2) in the uptake of antiviral nucleoside analogues for comparison with the previously reported drug transport properties of concentrative (Na+-dependent) CNT nucleoside transport proteins. The human and rat nucleoside transport proteins hENT1, rENT1, hENT2 and rENT2 were produced in Xenopus oocytes and investigated for their ability to transport three 3'-deoxy-nucleoside analogues, ddC (2'3'-dideoxycytidine), AZT (3'-azido-3'-deoxythymidine) and ddI (2'3'-dideoxyinosine), used in human immunodeficiency virus (HIV) therapy. The results show, for the first time, that the ENT2 transporter isoform represents a mechanism for cellular uptake of these clinically important nucleoside drugs. Recombinant h/rENT2 transported ddC, ddI and AZT, whilst h/rENT1 transported only ddC and ddI. Relative to uridine, h/rENT2 mediated substantially larger fluxes of ddC and ddI than h/rENT1. Transplanting the amino-terminal half of rENT2 into rENT1 rendered rENT1 transport-positive for AZT and enhanced the uptake of both ddC and ddI, identifying this region as a major site of 3'-deoxy-nucleoside drug interaction.
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PMID:Transport of antiviral 3'-deoxy-nucleoside drugs by recombinant human and rat equilibrative, nitrobenzylthioinosine (NBMPR)-insensitive (ENT2) nucleoside transporter proteins produced in Xenopus oocytes. 1146 8

Both the incidence and prevalence of human immunodeficiency virus infection are increasing in the world. Diseases of ENT districts are more frequent in human immunodeficiency virus-infected patients and involve all the otolaryngological sites. The otorhinolaryngological manifestations in association with HIV infection are mainly atypical, so common in the clinical practice, really aspecific and very frequent in ENT daily routine (such as sinusitis, otitis, etc.) and, therefore, immunodeficiency may not be suspected. In other cases, ENT evidence is more peculiar or unusual, such as opportunistic infections, rare neoplasm and tumours with an unusual course, giving a very high suspect of a human immunodeficiency virus-related infection. The most frequent malignant neoplasm is Kaposi's Sarcoma which is extremely rare in non-human immunodeficiency virus-infected subjects; the second most frequent is non-Hodgkin's lymphoma with 50% in extranodal sites (oral and maxillary sinus). Following a review of the literature, modifications caused by current antiretroviral treatment on head and neck manifestations of human immunodeficiency virus infection have been evaluated. Highly active antiretroviral therapy is a new therapeutic strategy, based on poly-chemo-therapeutic schemes, providing simultaneously two or more anti-retroviral drugs. We have used highly active antiretroviral therapy in human immunodeficiency virus infection since 1997, substituting previous mono-chemotherapy based on Zidovudine or Didanosine alone. Highly active antiretroviral therapy is extremely efficient in reducing the viral load of human immunodeficiency virus and increasing CD4+ T-lymphocyte count. These biological effects are associated with an improvement in immune functions. To evaluate the effects of highly active antiretroviral therapy on otorhinolaryngological manifestations in human immunodeficiency virus infection, we performed a retrospective study on 470 adults, observed over 14 years (1989-2002) and constantly receiving the same treatment, with follow-up from 7 to 80 months. A total of 250 subjects underwent mono-antiretroviral chemotherapy (1989-1996), while 220 underwent highly active antiretroviral therapy (1997-2002). The results of the retrospective study showed that highly active antiretroviral therapy has greatly improved the control of the immune-deficiency (increasing the range of CD4+), reducing the number of otorhinolaryngological manifestations (also tumours). On the other hand, 2 patients presented sudden unilateral hearing loss following treatment: toxicity due to association of new drugs cannot be excluded.
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PMID:Human immunodeficiency virus infection: personal experience in changes in head and neck manifestations due to recent antiretroviral therapies. 1608 Mar 13