Valuable clinical tips from recent medical meetings.

AIDS: Recent medical meetings have included presentations on dietary, pharmacologic, and biotechnological studies that have immediate value in improving the life span or health of persons with HIV. Several of these advances are highlighted, such as famciclovir has been approved for herpes treatment in HIV-infected people and Vitamin E supplementation of at least 400 IU daily can help lower the risk of heart problems. Results from several clinical trials are included.^ieng

Medical highlights of the 12th World AIDS Conference.

AIDS: The underlying theme of the 12th World AIDS Conference in Geneva was that while significant progress has been made in fighting the epidemic worldwide, there are still areas in which the disease is spreading and infection rates are increasing. Some have estimated that 40 million individuals in the developing countries may be infected by the year 2000. The conference was attended by 13,000 people who were briefed on vaccine development, current treatment regimens, promising drugs under development or in testing, treatment of opportunistic infections, advances in understanding and treating AIDS-related dementia, and policy issues.^ieng

Antimicrobial agents and chemotherapy: highlights of the 38th Interscience Conference.

AIDS: The 38th Interscience Conference on Antimicrobial Agents and Chemotherapy featured information on new antiretroviral treatments, changes in dosing, and new vaccine information. Adefovir dipivoxil (Preveon) is a new nucleoside reverse transcriptase inhibitor that is administered once daily. A study of adefovir dipivoxil is described and the side effects are detailed. A clinical trial of the protease inhibitor Nelfinavir (Viracept) has shown that dosing twice a day may be as effective as the currently prescribed three times a day. Since lower dosing tends to increase a patient's adherence to treatment, it may have a long-term positive effect on treating HIV. Other drug treatments and possible changes in dosing are presented. A pneumococcal vaccine study is described, and it was found that the vaccine did not lead to an increase in viral load. Immunization against Pneumococcus is suggested for all adults who are HIV-infected.^ieng

New discoveries in the treatment of AIDS-related cancers.

AIDS: AIDS-related cancer research may also lead to advances in cancer treatment in HIV-negative people. Significant findings in the treatment of AIDS-related cancers were presented at the American Society of Clinical Oncology meeting. Researchers at the Center for AIDS Research at the University of California, San Diego, found that granulocyte-colony stimulating factor (G-CSF/Neupogen) was well-tolerated when administered to patients with AIDS. G-CSF could be administered to enhance the immune system rather than having patients undergo bone marrow transplantation. Vinorelbine (Navelbine), a chemotherapeutic agent, could be effective for the treatment of HIV-positive patients with previously-treated Kaposi's sarcoma (KS), according to Dr. Domenico Erranto of the Centro Di Riferimento Oncologia, Italy. The effects of commonly-used medications, particularly immunosupressive chemotherapy agents, on HIV viral replication are unknown. Preliminary findings from the AIDS Malignancy Program at the Illinois Masonic Cancer Center in Chicago suggest that standard chemotherapeutic agents do not significantly affect HIV activity when used in combination with anti-HIV drug therapies.^ieng

Another protease inhibitor proves highly effective.

AIDS: Nelfinavir (Viracept) is a well-tolerated and effective protease inhibitor, especially when used in combination with nucleoside analogues. When used in triple combination, it is even more effective. An ongoing trial showed that 11 patients showed no detectable level of virus after 12 weeks, and after 20 weeks, there were no new HIV-related infections in the group. The trial is continuing.^ieng

Clarithromycin for MAC prevention offers additional benefits.

AIDS: The use of clarithromycin in preventing Mycobacterium avium complex (MAC) may also prevent a number of other opportunistic infections in AIDS patients. A large multinational study showed a reduction in Pneumocystis carinii pneumonia (PCP), community-acquired pneumonia (CAP), and giardiasis, an intestinal disorder. The study involved participants with CD4 counts below 100.^ieng

Macrolides, azalides, and streptogrammins.

AIDS: The Third International Conference on the Macrolides, Azalides, and Streptogramins was held in Lisbon, Portugal. Conferees were given news on the latest advances in the development of innovative antibiotics belonging to these increasingly important groups of drugs, and learned of their expanding clinical indications. The following areas were emphasized at the conference: multiresistant gram-positive bacteremias in patients with serious underlying infections, azithromycin's effectiveness against acute community-acquired pneumonia, results of clarithromycin plus ethambutol in HIV-infected patients with MAC bacteremia, duodenal ulcers associated with Helicobacter pylori infections, and use of roxithromycin against AIDS-related cryptosporidium diarrhea.^ieng

ICAAC: what else is new?

AIDS: Three HIV-related topics were discussed at the 1995 Interscience Conference on Antimicrobial Agents and Chemotherapy. 1) Protease inhibitors given in high doses are able to delay resistance, even when given as monotherapy. Combination therapies are more successful than monotherapies, and triple combinations are more effective than double combinations. 2) A cytomegalovirus (CMV) vaccine was well-tolerated and effective in healthy CMV-immune adults. A phase III clinical trial found valaciclovir, a new antiviral agent, to be more effective than acyclovir for preventing CMV in advanced HIV infection. A unique surgically-placed intraocular implant, which delivers ganciclovir, appears to slow the progression of CMV retinitis more than intravenous ganciclovir. 3) Clarithromycin is the best drug for preventing and treating Mycobacterium avium complex (MAC). The three-drug treatment combination of clarithromycin, rifabutin, and ethambutol is more effective than the four-drug combination of ciprofloxacin, ethambutol, rifampin, and clofazamine.^ieng

Highlights of the Eighth European Cancer Conference.

AIDS: Clinical and research oncologists, cancer nurses, and other healthcare professionals met to discuss the latest advances in prevention and treatment of cancers at the Eighth European Cancer Conference. Professionals discussed a novel treatment (Irinotecan) for advanced colorectal cancers; a unique anticancer agent (Docetaxel) effective in hard-to-treat head and neck cancer; a highly active neoadjuvant chemotherapy regimen for operable breast cancer; and a cytoprotective agent (Amifostine) capable of protecting normal tissue from radiation and chemotherapeutic toxicity.^ieng

Doxil offers hope to KS sufferers.

AIDS: The Food and Drug Administration (FDA) has given market clearance to Doxil, an injectable stealth liposome formulation of doxorubicin, for treatment of Kaposi's sarcoma (KS) in AIDS patients with disease that has progressed on prior combination chemotherapy or in patients who are intolerant to such therapy. The drug has a circulating half-life of approximately fifty hours, thus enabling the stealth liposomes to concentrate the encapsulated drug in areas of the body where new blood vessels are being formed and are leaky, such as tumors. To be eligible for the Sequus Pharmaceutical (Doxil) program, patients must meet medical and financial criteria. Interested parties may contact the Doxil Patient Assistance Program.^ieng

Non-HIV highlights of the 35th Interscience Conference on Antimicrobial Agents and Chemotherapy.

AIDS: The main non-HIV presentations at the 1995 Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) are reviewed. Issues addressed vancomycin resistance, the use of antibiotics in overcoming drug resistance, two new classes of antibiotics that are active against resistant gram-positive bacteria, hepatitis A screening for low-risk prospective travelers to developing countries, a new antiviral agent (valaciclovir) for use against genital herpes, amphotericin B lipid therapy for invasive candidiasis, and cryptosporidium as a major cause of severe diarrhea.^ieng

Highlights of the Eighth International Conference on Antiviral Research.

AIDS: Discussions and research findings of the Eighth International Conference on Antiviral Research held in April 1995, which examined the development of new antiviral agents and novel therapeutic combinations against HIV infection and AIDS-related infections, are summarized. Specific topics include the combination of antiretroviral treatment approaches and novel chemoimmunotherapeutics and the long-term safety and efficacy of ddI and d4T. The paper concludes by summarizing research findings concerning therapies for cytomegalovirus disease and herpes.^ieng

Lamivudine useful against hepatitis B-HIV co-infection.

AIDS: Research is showing lamivudine (3TC) is useful against hepatitis B-HIV co-infection in severely immunodeficient HIV-HBV co-infected persons when given 300 mg twice daily. The open-label study cited involved 29 HIV-HBV co-infected persons, with mean CD4+ counts of about 100. Patients were also positive for HBV antigens for at least one year. After six months of treatment with 3TC, all patients tested were negative for HBV-DNA. It was found that when 3TC was stopped, HBV-DNA went up, and when it was resumed, HBV-DNA went down again. While under therapy, patients showed no detectable DNA replication.^ieng

Loss of naive T cells may play major role in weakened immune response.

AIDS: New evidence suggests that HIV weakens the patient's immune system not by devastating the body's CD4+ cells, but by destroying naive T cells. In people with AIDS, naive T cell and (adult) memory cell ratio become skewed, with about eighty percent of the T cells being memory T cells. Naive T cell loss reduces the patient's ability to respond to new dangers, thus explaining the AIDS patient's susceptibility to opportunistic disease. A longitudinal study is needed to establish the role of naive T cells in HIV-positive persons and the impact of HIV infection on these cells. Dr. Mario Roederer of Stanford University School of Medicine states that treatment options must include treatment that restores the immune system, and that strategies must take into account a patient's naive T-cell count.^ieng

Arginine synthesis and nitrogen excretion in the myxomycete Physarum polycephalum.

The nitrogen excretory metabolism of the myxomycete Physarum polycephalum was studied. When cultured in partially defined broth medium or on agar, the principal excretory product was ammonia nitrogen. A small, variable quantity of urea was excreted in liquid culture. No uric acid or other purines were detected in the cultures. When microplasmodia were incubated with sodium [14C]bicarbonate, radioisotope was incorporated into citrulline, arginine, and urea. Incubation with L-[carbamoyl-14C]citrulline yielded labelled arginine, urea, and CO2. Substantial urease activity was found in extracts of the microplasmodia. These results, in conjunction with the lack of an absolute nutritional requirement for arginine, provide evidence that Physarum has a functional arginine biosynthetic pathway, an arginase, and a urease.