Antiretroviral treatment: when to start and with what?

Quantitative ultrasound (QUS) of the calcaneus is a widely utilized method for bone densitometry. However, the meaning of measured parameters, such as speed of sound (SOS) and broadband attenuation (BUA), is not well established. We performed in vitro measurement of dissected human calcaneus (n = 60; male 29, female 31; mean age 81 years) using two QUS machines and also measured bone densities using SXA, DXA and pQCT. Finally, we investigated breaking strength of the calcaneus and studied the correlation with QUS parameters and other assessed parameters. The two QUS measurements were in good agreement in most experiments. SOS correlated most closely with bone mineral densities assessed by pQCT and did not correlate with factors related to bone size, while BUA showed the highest correlation with BMC and association with parameters related with bone size such as bone area and bone width. With maximal breaking stress of the calcaneus, correlations were almost equal among QUS parameters and bone mineral density. We conclude that SOS is the parameter most closely associated with true bone mineral density (g/cm3), whereas BUA represents both bone mineral density and bone size, mimicing BMD assessed by DXA or SXA.     

Antiretroviral therapies

We describe an algorithm which enables us to search the conformational space of the side chains of a protein to identify the global minimum energy combination of side chain conformations as well as all other conformations within a specified energy cutoff of the global energy minimum. The program is used to explore the side chain conformational energy surface of a number of proteins, to investigate how this surface varies with the energy model used to describe the interactions within the system and the rotamer library. Enumeration of the rotamer combinations enables us to directly evaluate the partition function, and thus calculate the side chain contribution to the conformational entropy of the folded protein. An investigation of these conformations and the relationships between them shows that most of the conformations near to the global energy minimum arise from changes in side chain conformations that are essentially independent; very few result from a concerted change in conformation of two or more residues. Some of the limitations of the approach are discussed.     

Antiretroviral therapy for pediatric and adolescent HIV

As the number of children infected in the HIV epidemic increases, the school nurse can play an important role in ensuring that these children receive comprehensive health care. Compliance with following an immunization program for HIV-infected children is a potential problem for various reasons. Many of these children come from homes where the mother also has HIV/AIDS. She is likely to be involved in keeping her family together, caring for her own health needs, and meeting financial and social needs of her family. Access to health care may be limited. The majority of vaccines administered within the first few months of life are parenteral and consist of inactivated antigens. Children or infants who are immunosuppressed may be unable to respond to the immunogen, thus rendering them susceptible to many infectious diseases. Heterosexual transmission and pregnancy compound the problems of HIV/AIDS (Flynn, 1994). Compliance following an immunization schedule becomes a greater challenge when working with the adolescent population. Parents may not understand that the risk of receiving vaccine, MMR for example, is less than the risk of severe complications associated with the diseases themselves. Coordination of care between the child, parent, and school district personnel is imperative to minimize the risk of further health-related problems of the HIV-infected child. Encouraging regular immunizations can decrease the child's susceptibility to infection, and administering medications properly can enhance the benefits of the drug therapy. An excellent resource for answering questions of school nurses related to HIV/AIDS is the National Pediatric and Family HIV Resource Center; contact Elaine Gross, R.N., M.S. at 1-800-362-0071.     

Antiretroviral treatment with nucleoside analogs does not decrease the viremia of the hepatitis C virus in patients with HIV-1 infection

Leiomyosarcoma is an uncommon malignant tumour of the pancreas. Many retroperitoneal leiomyosarcomas grow silently and are extremely large when diagnosed. We report a 45 year old lady who presented with abdominal lump and haemoptysis. Ultrasound guided biopsy of the mass revealed a pancreatic leiomyosarcoma. The patient had lung metastasis and received chemotherapy. She is alive with disease at last followup.     

Antiretroviral therapy during pregnancy. Beyond AZT (ZDV)

Although zidovudine (ZDV) monotherapy remains the standard for the prevention of mother-to-child transmission, it may now be inadequate therapy for treatment of the mother. The safety and efficacy of the newer therapeutic agents have yet to be established during pregnancy; however, the need to maintain maternal health mandates that clinicians understand the benefits and limitations of antiretroviral therapy beyond ZDV.     

Antiretroviral uptake in Australia: medical, attitudinal and cultural correlates

The objective of this study was to describe the medical, attitudinal and cultural correlates of antiretroviral uptake amongst people living with HIV/AIDS (PLWHA) in Australia. Stratified purposive sampling produced a sample of 925 PLWHA, which represents 8.3% of the current population of PLWHA in Australia. Respondents completed a self-administered questionnaire which revealed that 78% of respondents were using antiretroviral drugs for HIV/AIDS. Logistic regression revealed that PLWHA were more likely to use antiretroviral drugs if they had more favourable attitudes toward antiretroviral drugs, if they had been diagnosed with an AIDS-defining illness, and if they had ever had a CD4/T-cell count below 400 copies/ml blood. Women were less likely than men to use antiretroviral drugs, and logistic regression revealed different predictors of antiretroviral drug use amongst men and women. Given the importance of attitudes toward antiretroviral drugs, it is likely that if the current confidence in antiretroviral drugs were to change, this would be reflected in an equally rapid cessation of treatment amongst many PLWHA.     

Antiretroviral therapy for HIV infection. Heartening successes mixed with continuing challenges

Probably nothing in the field of medicine has changed as rapidly over the last decade as antiretroviral (ARV) therapy for HIV infection. New insights into pathogenesis, new tests for measuring virus levels in plasma, and availability of powerful new drugs have combined to transform the care of persons with HIV infection into a field infused with real hope. However, ARV therapy remains complex, expensive, and not universally effective or available. This article focuses on a general approach to the use of ARV agents.     

Antiretroviral treatment of men infected with human immunodeficiency virus type 1 reduces the incidence of heterosexual transmission. Italian Study Group on HIV Heterosexual Transmission

OBJECTIVE: To determine the incidence of heterosexual human immunodeficiency virus type 1 disease transmission and the effect of zidovudine therapy on this risk of transmission. DESIGN: A cohort of 436 monogamous seronegative female sexual partners of human immunodeficiency virus type 1-infected males was followed up for 740 person-years with regular structured interviews and laboratory tests. PATIENTS: At enrollment of the women, 50% of their infected partners had one or more signs of disease progression (symptoms of acquired immunodeficiency syndrome, p24 antigen positivity, or CD4+ cell counts lower than 0.4 x 10(9)/L) and 15% were treated with zidovudine. MAIN OUTCOME MEASURE: Incidence rates of seroconversion were calculated and relative risks were estimated as incidence rate ratios. RESULTS: Twenty-seven women seroconverted during follow-up, and the incidence of seroconversion was 3.7 per 100 person-years. Seroconversion was about six times more frequent (relative risk, 5.8; 95% confidence interval, 2.2 to 15.3) in couples not using condoms. Men with signs of disease progression transmitted infection to their partners more frequently and were more frequently treated with zidovudine. When the risk of transmission was estimated accounting for disease progression, the rate of transmission in zidovudine-treated men was lower than in untreated men (relative risk, 0.5; 95% confidence interval, 0.1 to 0.9). CONCLUSION: Treatment of human immunodeficiency virus type-1 infected men with zidovudine reduces, but does not eliminate, heterosexual transmission of infection. Behavioral counseling that encourages sexual practices with a lower risk of transmission remains the most important method of prevention.