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A peptide with neurotoxic effect on mammals, purified from the venom of the spider Phoneutria nigriventer, was studied regarding its primary structure and its effects on voltage-gated calcium channels. The peptide, named ω-phonetoxin-IIA, has 76 amino acids residues, with 14 Cys forming 7 disulphide bonds, and a molecular weight of 8362.7 Da. The neurotoxicity is a consequence of the peptide's blocking effects on high-voltage-activated (HVA) calcium channels. N-type HVA calcium channels of rat dorsal root ganglion neurons are blocked with affinity in the sub-nanomolar concentration range. The toxin also blocks L-type channels of rat ß pancreatic cells, with an affinity 40 times lower. Although not studied in detail, evidence indicates that the toxin also blocks other types of HVA calcium channels, such as P and Q. No effect was observed on low-voltage-activated, T-type calcium channels. The significant homologies between ω-phonetoxin-IIA and the peptides of the ω-agatoxin-III family, and the overlapping inhibitory effects on calcium channels are discussed in terms of the structure-activity relationship.

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More than 18 million persons in the the world are estimated to have been infected with human immunodefeiciency virus (HIV), the cause of the acquired immunodeficiency syndrome (AIDS). As immunodeficiency progresses, these persons become susceptible to a wide variety of opportunistic infections (OIs). The spectrum of OIs varies among regions of the world. Tuberculosis is the most common serious OI in sub-Saharan Africa and is also more common in Latin America and in Asia than in the United States. Bacterial infections such as toxoplasmosis, cryptosporidiosis, and isosporaisis are also common in Latin America. Fungal infections, including cryptococcosis and Penicillium marneffei infection, appear to be prevalent in Southeast Asia. Despite limited health resources in these regions, some measures that are recommended to prevent OIs in the United States may be useful for prolonging and improving the quality of life of HIV-infected persons. These include trimethoprim-sulfamethoxazole to prevent Pneumocystis carinii pneumonia, toxoplasmosis, and bacterial infections; isoniazid to prevent tuberculosis; and 23-valent pnemococcal vaccine to prevent disease due to Streptococcus pneumoniae. Research is needed to determine the spectrum of OIs and the efficacy of various prevention measures in resource-poor nations, and health officials need to determine a minimum standard of care for HIV-infected persons. An increasing problem in the developing world, HIV/AIDS should receive attention comparable to other tropical diseases (AU).

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Recombinant human interferon gamma enhances neutrophil respiratory burst and bactericidal activity in patients with chronic granulomatous disease. Mononuclear leukocytes of patients with the hyperimmunoglobulinemia E syndrome (Job syndrome) produce low or undetectable levels of this lymphokine. For these reasons we have restudied neutrophil chemotaxis in a group of our patients with the syndrome and determined the effect of recombinant human interferon gamma on the responses. Each of the patients had neutrophil chemotactic responses ranging from 22% to 55% of simultaneous control values (p less than 0.001). After incubation with interferon gamma, a significant improvement in chemotactic responsiveness was observed in the neutrophils of each of the patients (mean 301% of baseline chemotaxis; p less than 0.008). These data suggest the need for a double-blind, placebo-controlled trial of interferon gamma in a larger group of patients with the syndrome of hyperimmunoglobulinemia E and recurrent infections.

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The high cumulative incidence of AIDS and the large percentage of AIDS patients with no identified risks in Belle Glade, Florida, were evaluated through case interviews and neighborhood-based seroepidemiologic studies. It was found that of 93 AIDS patients reported between July 1982 and 1 August 1987, 34 could be directly linked to at least one other AIDS patient or to a person with AIDS-related complex by sexual contact, sharing of needles during intravenous drug abuse (or both), or perinatal exposure; of 877 randomly selected adults, 28 had antibodies to HIV; no person over age 60 and none of 138 children aged 2 to 10 years had antibodies to HIV; no clustering of infected persons within households occurred, except in sex partners; and HIV-seropositive adults were more likely than HIV-seronegative adults to be from Haiti, have a lower income, report sex with intravenous drug abusers, and have a history of previous treatment for sexually transmitted diseases. The presence of antibodies to five arboviruses prevalent in South Florida or the Caribbean did not correlate significantly with HIV infection. The high cumulative rate of AIDS in Belle Glade appears to be the result of HIV transmission through sexual contact and intravenous drug abuse; the evidence does not suggest transmission of HIV through insects.

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Homosexual and heterosexual patients with the acquired immunodeficiency syndrome were compared by risk group. Race; diagnoses; history of sexually transmitted diseases, sexual behavior, and drug use; and socioeconomic indicators differed considerably among risk groups, suggesting different risk factors for acquisition of the syndrome. Patients in the homosexual, intravenous drug user, and Haitian risk groups differed in their serologic response to cytomegalovirus and syphilis testing, presumably due to lifestyle-related exposures. Differences in the rate of recovery of cytomegalovirus, serum levels of IgA and IgG, and antibody titers to Epstein-Barr virus were noted among patients with different diagnoses. We conclude that in studies of risk factors for the acquired immunodeficiency syndrome, patients should be analyzed by risk group and diagnoses.

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Between June 1981 and February 1983, the Centers for Disease Control (Atlanta) received reports of 1,000 patients living in the United States who met a surveillance definition for the acquired immune deficiency syndrome (AIDS). Seventy-three percent of these patients were diagnosed after January 1, 1982. The 1,000 patients included 284 with Kaposi's sarcoma (KS), 497 with Pneumocystis carinii pneumonia (PCP), 83 with KS and PCP, and 136 with opportunistic infections other than PCP. The overall mortality has been 39.2%. Cases have been reported from 32 states and the District of Columbia; New York, California, New Jersey, and Florida account for 82.7% of the reports. All but 61 of the patients could be classified into one or more of the following groups: homosexual or bisexual men, intravenous drug abusers, Haitian natives, or patients with hemophilia. Epidemiologic trends in AIDS cases are consistent with the gradual extension of an infectious agent into new populations.

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