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3191. HIV prevention in developed countries.
作者: T J Coates.;P Aggleton.;F Gutzwiller.;D Des Jarlais.;M Kihara.;S Kippax.;M Schechter.;J A van den Hoek.
来源: Lancet. 1996年348卷9035期1143-8页
HIV prevention in developed countries is marked by impressive successes and dismal failures. The successes point the way to what works; the failures highlight obstacles that must be overcome. Successes include important behavioural changes among gay and bisexual men, antiviral use to prevent vertical transmission, and securing the safety of the blood supply. New strategies are needed to reach the residual of individuals continuing with unsafe practices (a special hazard in high-prevalence areas); to reach young people who are beginning to engage in sexual relations and injection drug use; and to overcome political opposition to prevention strategies.
3193. Pathophysiology of itching.
Itching is the predominant symptom of skin disease but it is ill-understood and a challenge for future research. Even the major nerve pathways for itch, and its relationship to pain are debatable. In inflamed skin, histamine plays a major role and its mode of release from mast cells in, for example, chronic urticaria is now better appreciated. Tachykinins including substance P and cytokines including interleukin-2 are evidently important peripherally. Opioid mu-receptor-dependent processes activate inhibitory circuits in the central nervous system and regulate the extent of intensity and quality of perceived itch. It is proposed that stimulation of large areas of skin such as by scratching, generates inhibitory activity which suppresses itch excitation. Therapeutic intervention based upon understanding these regulatory processes is a real prospect.
3194. HIV vaccines: where we are and where we are going.
As the HIV-1 epidemic continues to spread world wide, the need for an effective vaccine remains urgent. Efforts to develop such a vaccine have been hampered by three main factors: (a) the extraordinary ability of the virus to mutate; (b) inability of most known specificities of anti-HIV antibodies to neutralise HIV primary isolates consistently; and (c) lack of understanding of the correlates of protective immunity to HIV infection. In view of the complex biology of HIV-host interactions, the most fruitful avenue may be development of multivalent HIV immunogens tailored to HIV isolates in specific geographical locations.
3195. Paediatric HIV infection.
By the year 2000 there will be six million pregnant women and five to ten million children infected with HIV-1. Intervention strategies have been planned and in some instances already started. A timely and cost-effective strategy needs to take into account that most HIV-1 infected individuals reside in developing countries. Further studies are needed on immunological and virological factors affecting HIV-1 transmission from mother to child, on differential disease progression in affected children, and on transient infection.
3196. Antiretroviral drugs for AIDS.
Treatment of HIV disease with antiretroviral agents has changed considerably. We now know that monotherapy is not the best strategy in most cases to combat rapid turnover of virus and development of resistance (the exception being mother-to-child transmission) and various combination drug regimens are being explored. Apart from the main drug groups, consisting of nucleoside analogues, proteinase inhibitors, and reverse-transcriptase inhibitors, many new compounds are under development. The timing of therapy may likewise be important, and the indications of benefit from early initiation of treatment need to be confirmed in randomised trials. Overall, there is far more optimism about the use of drugs in HIV infection than there was several years ago.
3198. HIV-related oral disease.
Few people with HIV infection fall to experience oral lesions during the course of their disease. Oral mucosal and salivary gland manifestations include several that were not seen before the AIDS epidemic, while others are more severe in this population. Oral lesions reflect HIV status and the stage of immunosuppression, are important elements in HIV staging and classification schemes, raise pertinent questions about mucosal aspect of immunosuppression, and provide therapeutic challenges. Their pervasive nature and biological significance emphasise the importance of a careful oral examination as part of the general clinical evaluation.
3199. HIV-related skin diseases.
Disorders of the skin and mucous membranes, including various infections, Kaposi's sarcoma, and miscellaneous conditions, occur throughout the course of HIV infection, affecting more than 90% of patients at some time. These lesions are often the first manifestations of symptomatic HIV disease. Clinicians need to be aware of these diagnoses and the order of their appearance since correct interpretation is essential for counselling patients about the progression of their illness and for initiating appropriate therapy.
3200. The discrepancy in discrepant analysis.
Discrepant analysis is a widely used technique that attempts to provide estimates of sensitivity and specificity in the presence of an imperfect gold-standard. This technique has been applied by many researchers to estimate the sensitivity and specificity of DNA-amplification tests for Chlamydia trachomatis such as the plasmid-based ligase chain-reaction and polymerase chain-reaction tests. However, the sensitivity and specificity estimates obtained by discrepant analysis are upwardly biased, and this bias remains even when a perfect test is used to resolve the discrepant results. This technique should not be adopted for evaluating the performance of a diagnostic test.
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