Effect of astaxanthin on kidney function impairment and oxidative stress induced by mercuric chloride in rats.

Reactive oxygen species are implicated as mediators of tissue damage in the acute renal failure induced by inorganic mercury. Astaxanthin (ASX), a carotenoid with potent antioxidant properties, exists naturally in various plants, algae, and seafoods. This paper evaluated the ability of ASX to prevent HgCl(2) nephrotoxicity. Rats were injected with HgCl(2) (0 or 5 mg/kg b.w., sc) 6h after ASX had been administered (0, 10, 25, or 50mg/kg, by gavage) and were killed 12h after HgCl(2) exposure. Although ASX prevented the increase of lipid and protein oxidation and attenuated histopathological changes caused by HgCl(2) in kidney, it did not prevent creatinine increase in plasma and delta-aminolevulinic acid dehydratase inhibition induced by HgCl(2). Glutathione peroxidase and catalase activities were enhanced, while superoxide dismutase activity was depressed in HgCl(2)-treated rats when compared to control and these effects were prevented by ASX. Our results indicate that ASX could have a beneficial role against HgCl(2) toxicity by preventing lipid and protein oxidation, changes in the activity of antioxidant enzymes and histopathological changes.

Medical examiner samples: a source for dengue surveillance

Post-mortem medical examiner samples may be useful for sentinel surveillance of disorders usually detected by antibody determinations on specimens from ill patients or from surveys. We found anti-dengue IgM positivity in 3(23/780) and anti-dengue IgG positivity in 77(597/777) of sera obtained at the Puerto Rico medical examiner (Institute of Forensic Sciences) in December 2000, April 2001, and October 2001. This approach may be a useful alternative for estimating the population prevalence of serologic markers for dengue and other infectious diseases.

Effect of human immunodeficiency virus type 1 on intracellular activation and superoxide production by neutrophils.

The immunopathogenesis of AIDS is associated with the development of opportunistic infections by intracellular pathogens that can invade and reproduce freely because of impaired cellular functions. Neutrophils from asymptomatic human immunodeficiency virus (HIV) type 1-infected persons and from symptomatic patients with AIDS were found to retain normal phagocytosis activity while producing significantly less superoxide than neutrophils from HIV-1-negative subjects, when stimulated through Fc receptors or protein kinase C. After priming with a synthetic HIV-1 envelope peptide and stimulation via the Fc receptor, the neutrophils from HIV-1-negative controls had suppressed superoxide production, reduced phosphorylation of two unidentified cellular proteins, and increased expression of a third phosphoprotein. These results suggest that HIV-1 can produce direct functional damage of neutrophils through binding of envelope components to the cell membrane.

Properties of virus-like particles produced by SIV-chronically infected human cell clones.

SIVsm chronically infected cultures were obtained after infection of CEMX174 cells with either SIVsmH3 or SIVsmE660. These phenotypically CD4 cells, formed syncytia but only when cocultivated with CD4+ cells. Single cell clones were derived from these cultures and examined for the production of virus-specific proteins. The majority of the clones expressed SIV p27 antigen and low levels of virus reverse transcriptase activity. Western blot analysis, performed with either monoclonal or polyclonal sera, showed that a chronically infected clone (B7) produced particles which contained envelope (gp135 and gp43), gag precursors and gag proteins (p27, p16 and p8). However, these particles (SIVsmB7) lacked detectable levels of vpx and of integrase, and contained several fusion proteins which expressed viral protease antigens. This defective virus failed to infect established CD4+ cell lines, as well as primary cultures of macrophages and of peripheral blood lymphocytes, obtained both from humans and from rhesus macaques. Lack of infection correlated with lack of viral DNA detection by PCR amplification of genomic DNA extracted from these cell cultures. In addition, SIVsmB7 virus lacked infectivity in vivo. Rhesus macaques inoculated with high concentrations of SIVsmB7 showed no viremia and their PBMC were PCR negative. Thus, B7 cells produced stable, non-infectious virus mutants, which contained env and gag proteins, but lacked detectable amounts of vpx and of enzymes required for virus replication. Due to the high constitutive expression of this virus-like particle, we are now testing this preparation as a vaccine.

Opportunistic invasion of the heart in Hispanic patients with acquired immunodeficiency syndrome.

One hundred consecutive patients who died of the acquired immunodeficiency syndrome (AIDS) were studied with an emphasis on the heart. Thirty-two patients showed pathologic changes. The pathologic findings included infection by Histoplasma capsulatum, Toxoplasma gondii, Mycobacterium tuberculosis, cytomegalovirus. Cryptococcus neoformans, and atypical mycobacteria. Noninfectious pathologic findings included nonspecific myocarditis, focal necrosis, focal fibrosis, and acute subendocardial infarction.

AIDS and the heart in the Caribbean: a silent entity.

PIP: Autopsies were performed by the cardiac pathology laboratory of 74 of 100 consecutive AIDS patients who died in Puerto Rico. The 32 with cardiac pathology are reviewed here. There were 27 males and 5 females, averaging 33 years old. 84% were heroin users and/or homosexual, and of the remaining 16%, 2 had heroin users and/or homosexual, and of the remaining 16%, 2 had received blood transfusions. The immediate cause of death was either respiratory or nervous system failure. One case of pericardial effusion (300 ml) associated with pleural effusion and ascites was found, but it was not clinically evident. 6 had cardiomegaly defined by cardiac mass 350 gm in males or 300 gm in females. There were no EKG findings other than sinus tachycardia with occasional ventricular premature beats. The most common pathological finding was nonspecific myocarditis. There were 5 cases with histoplasma showing cardiac foci of histiocytes, 3 with cardiac toxoplasma foci, 3 with mycobacterium granulomas in the myocardium or pericardium, 2 with cytomegalovirus myocarditis with intranuclear inclusions, 2 with cryptococcus neoformans, and 1 with atypical mycobacteria in the myocardium. 2 additional patients had coagulation necrosis of myocardial fibers. These results indicate that myocarditis is common in AIDS patients in Puerto Rico, especially in intravenous heroin users, and its causes are multiple. The clinical picture in terms of congestive heart failure or arrhythmias, however, is silent.^ieng