Effect of pre-cooling on the shelf-life and quality of formosa papaya.

Papaya is a climacteric fruit, rapidly ripening after harvesting due to ethylene production and increased respiratory rate. This swift ripening results in softening of fruit tissues, shortening the fruit shelf life. Pre-cooling serves as an alternative to minimize fruit ripening and post-harvest losses by reducing metabolism. This study aimed to evaluate the effect of pre-cooling on the quality and conservation of Formosa 'Tainung I' papaya. Papayas at maturation stage II were obtained from a commercial orchard with conventional production. The experimental design was a completely randomized 4×6 split-plot scheme, with pre-cooling treatments (Control, without pre-cooling treatment; pre-cooling at 15 °C in a cold chamber; pre-cooling at 7 °C in a cold chamber; and forced-air cooling at 7 °C) in the plot, and days of storage (0, 7, 14, 21, 28, and 35 days) in the subplot. Pre-cooling effectively delayed the ripening and senescence of Formosa papaya, reducing the loss of green color and firmness. Regardless of the treatment used, chilling injury and incidence of fungi from the genus Fusarium and Alternaria limited the shelf life of Formosa 'Tainung I' papaya up to 21 days of storage. Additionally, the appearance of hardened regions in the pulp compromised the sensory quality of the fruits, necessitating further investigation into the causes of this disorder.

Maturation and antioxidant activity of 'Giombo' and 'Rama Forte' persimmons produced in the Brazilian semiarid.

The objective of this work was characterizing persimmons of the 'Giombo' and 'Rama Forte' cultivars harvested at different ripening stages in the Brazilian semiarid. Fruits were harvested at three ripening stages - green, semi-ripe and ripe - then evaluated for the following characteristics: fruit weight and diameter, skin and pulp color, fruit firmness, pulp pH, soluble solids content, titratable acidity, SSC/TA ratio, total soluble sugars, reducing sugars, astringency index, and the contents of tannin, vitamin C, carotenoid, ß-carotene, and total extractable polyphenols. Also, total antioxidant activity by the DPPH and ABTS methods and pectin methylesterase, and polygalacturonase enzyme activities were evaluated. Two experiments were carried out in a completely randomized design, one for each cultivar, with treatments consisting of different stages of maturation, with five replications of three fruits each. Data were submitted to analysis of variance and the differences between the means were compared using the Tukey test at 5% probability. Fruit firmness and soluble solids content did not vary between maturation stages for any of the cultivars. However, the skin color index increased with advancing maturation for both 'Giombo' and 'Rama Forte'. The astringency index, the content of total extractable polyphenols, soluble tannins and the antioxidant capacity were lower in fruits harvested at the ripe stage, for both cultivars. It can be concluded that persimmons of the 'Giombo' and 'Rama Forte' cultivars present better physicochemical quality characteristics when harvested when ripe, with a totally yellow skin.

Salt stress and organic fertilization on the growth and biochemical metabolism of Hylocereus costaricensis (red pitaya) seedlings / Estresse salino e fertilização orgânica sobre o crescimento e metabolismo bioquímico de mudas de Hylocereus costaricensis (pitaia vermelha)

Red pitaya (Hylocereus costaricensis) is a promising species, with high cultivation potential due to the organoleptic and functional qualities of its fruits. However, irrigation water salinity can affect the crop yield. Therefore, materials rich in organic substances can minimize the damage caused by excess salts in soil and/or water. Thus, the objective of this study was to evaluate the influence of organic matter sources as attenuators of salt stress on the production and biochemical responses of red pitaya seedlings. A completely randomized design in 4 × 5 factorial scheme, with five sources of organic matter (humus, sheep manure, biofertilizer, organic compost and sand + soil) and four salinities (0.6, 2.6, 4.6 and 6.6 dS m-1) with four replicates and two plants per plot was used. The shoot length, root length, cladode diameter, number of cladodes, number of sprotus, root volume, shoot dry mass, root dry mass and total dry mass, root and shoot dry mass ratio, chlorophyll a, b and total, amino acids and soluble sugars were evaluated at 120 days after the treatments began to be applied. Red pitaya is moderately tolerant to salinity (ECw from 4.0 to 6.0 dS m-1). Organic compost and sheep manure attenuate the harmful effects of salinity on red pitaya seedlings. Under salt stress conditions, red pitaya plants increase their levels of proline, amino acids and total sugars.

A pitaia vermelha (Hylocereus costaricensis) é uma promissora espécie, com elevado potencial de cultivo devido às qualidades organolépticas e funcionais de seus frutos. Entretanto, a salinidade da água de irrigação pode afetar o rendimento produtivo da cultura. Diante disso, materiais ricos em substâncias orgânicas podem minimizar os danos provocados pelo excesso de sais no solo e/ou na água. Assim, o objetivo deste trabalho foi avaliar a influência de fontes de matéria orgânica como atenuante do estresse salino na produção e respostas bioquímicas de mudas de pitaia vermelha. O delineamento inteiramente casualizado em esquema fatorial 4 × 5, com cinco fontes de matéria orgânica (húmus, esterco ovino, biofertilizante, composto orgânico e areia + solo) e quatro salinidade (0.6, 2.6, 4.6 e 6.6 dS m-1), com quatro repetições e duas plantas por vaso foi utilizado. O comprimento da parte aérea, comprimento da raiz, diâmetro do cladódio, número de cladódios, número de brotos, volume da raiz, massa seca da parte aérea, massa seca da raiz e massa seca total, razão da massa seca da raiz e da parte aérea, clorofila a, b e total, aminoácidos e os açúcares solúveis foram avaliados aos 120 dias após o início da aplicação dos tratamentos. A pitaia vermelha é moderadamente tolerante a salinidade. O composto orgânico e estrume ovino atenuam os efeitos nocivos da salinidade nas mudas de pitaia vermelha. Sob condições de estresse salino, as plantas aumentam os níveis de aminoácidos e açúcares totais.

Effect of plasma and heat treatments on orange juice quality.

Heat treatment is used in the orange juice industry to neutralize the action of pathogenic microorganisms. However, it can reduce the nutritional value of the juice. Thus, our study assessed the cold plasma treatment as an alternative method against Escherichia coli and Candida albicans in 'Lima' orange juice. Both, plasma and heat treatments, reduced the amount of E. coli in the juice, inactivating 16.72 and 100%, respectively. Plasma did not inactivate C. albicans, but heat treatment inactivated 100%. Plasma and heat treatment increased Hue angle and luminosity (more yellowish juice). Plasma reduced vitamin C, carotenoids, and polyphenols content, while increased flavonoids. Heat treatment reduced the carotenoid content. However, neither heat nor plasma treatment altered the antioxidant activity. The plasma treatment reduced the intensity of color (chroma), the soluble solids content and the acidity ratio, total sugars, and the vitamin C content of juice compared to the heat-treated and control juices. Plasma-treated juice showed increased levels of yellow flavonoids, total phenolics and antioxidant activity until the 12th day of storage.

Effect of plasma and heat treatments on orange juice quality / Efeito de plasma e tratamento térmico na qualidade do suco de laranja

Heat treatment is used in the orange juice industry to neutralize the action of pathogenic microorganisms. However, it can reduce the nutritional value of the juice. Thus, our study assessed the cold plasma treatment as an alternative method against Escherichia coli and Candida albicans in 'Lima' orange juice. Both, plasma and heat treatments, reduced the amount of E. coli in the juice, inactivating 16.72 and 100%, respectively. Plasma did not inactivate C. albicans, but heat treatment inactivated 100%. Plasma and heat treatment increased Hue angle and luminosity (more yellowish juice). Plasma reduced vitamin C, carotenoids, and polyphenols content, while increased flavonoids. Heat treatment reduced the carotenoid content. However, neither heat nor plasma treatment altered the antioxidant activity. The plasma treatment reduced the intensity of color (chroma), the soluble solids content and the acidity ratio, total sugars, and the vitamin C content of juice compared to the heat-treated and control juices. Plasma-treated juice showed increased levels of yellow flavonoids, total phenolics and antioxidant activity until the 12th day of storage.

O tratamento térmico é utilizado na indústria de suco de laranja para neutralizar a ação de microrganismos patogênicos. No entanto, pode reduzir o valor nutricional do suco. Assim, o estudo avaliou o tratamento com plasma frio como método alternativo contra Escherichia coli e Candida albicans em suco de laranja 'Lima'. Ambos os tratamentos, plasma e calor, reduziram a quantidade de E. coli no suco, inativando 16.72 e 100%, respectivamente. O plasma não inativou C. albicans, mas o tratamento térmico inativou 100%. Plasma e tratamento térmico aumentaram o ângulo Hue e a luminosidade do suco (tom mais amarelo). O plasma reduziu o conteúdo de vitamina C, carotenóides e polifenóis, enquanto aumentou os flavonóides. O tratamento térmico reduziu o teor de carotenóides. No entanto, nem o calor nem o tratamento com plasma alteraram a atividade antioxidante. O tratamento com plasma reduziu a intensidade da cor (croma), o teor de sólidos solúveis e a razão de acidez, açúcares totais e o teor de vitamina C do suco em comparação com os sucos tratados termicamente e controle. O suco tratado com plasma apresentou maiores teores de flavonóides amarelos, fenólicos totais e atividade antioxidante até o 12º dia de armazenamento.

Salt stress and organic fertilization on the growth and biochemical metabolism of Hylocereus costaricensis (red pitaya) seedlings.

Red pitaya (Hylocereus costaricensis) is a promising species, with high cultivation potential due to the organoleptic and functional qualities of its fruits. However, irrigation water salinity can affect the crop yield. Therefore, materials rich in organic substances can minimize the damage caused by excess salts in soil and/or water. Thus, the objective of this study was to evaluate the influence of organic matter sources as attenuators of salt stress on the production and biochemical responses of red pitaya seedlings. A completely randomized design in 4 × 5 factorial scheme, with five sources of organic matter (humus, sheep manure, biofertilizer, organic compost and sand + soil) and four salinities (0.6, 2.6, 4.6 and 6.6 dS m-1) with four replicates and two plants per plot was used. The shoot length, root length, cladode diameter, number of cladodes, number of sprotus, root volume, shoot dry mass, root dry mass and total dry mass, root and shoot dry mass ratio, chlorophyll a, b and total, amino acids and soluble sugars were evaluated at 120 days after the treatments began to be applied. Red pitaya is moderately tolerant to salinity (ECw from 4.0 to 6.0 dS m-1). Organic compost and sheep manure attenuate the harmful effects of salinity on red pitaya seedlings. Under salt stress conditions, red pitaya plants increase their levels of proline, amino acids and total sugars.

Restoration over time and sustainability of Schinus terebinthifolius Raddi.

The success of recovery programs on degraded areas is dependent on the genetic material to be used, which should present heterozygosity and genetic diversity in native and recovered populations. This study was carried out to evaluate the model efficiency to enable the recovery of a degraded area of the Lower São Francisco, Sergipe, Brazil. The target species for this study was Schinus terebinthifolius Raddi. Three populations were analyzed, the recovered area, seed-tree source population, and native tree population border established to the recovered area. The random amplified polymorphic DNA (RAPD) markers were used for diversity analysis. Genetic structure was estimated to evaluate the level of genetic variability existent in each population. There was no correlation between the spatial distribution and the genetic distances for all trees of the recovered area. The heterozygosity present in the recovered population was higher than the native tree population. The seed-tree source population presents genetic bottlenecks. Three clusters were suggested (ΔK = 3) with non-genetic structure. High intra-population genetic variability and inter-population differentiation are present. However, gene flow may also introduce potentially adaptive alleles in the populations of the recovered area, and the native population is necessary to ensure the sustainability and maintenance of the populations by allelic exchange.

Populations of Erythrina velutina Willd. at risk of extinction.

The goal of this study was to characterize the structure of two natural populations of the coral tree using RAPD and ISSR markers. The study evaluated all individuals in two different areas in the northeastern region of Brazil: the first was in the riparian area, 10 km x 100 m along the edge of the lower São Francisco River, and the second was in the municipality of Pinhão, in a semiarid region between the municipalities of Neópolis and Santana do São Francisco. We used all the coral trees present in those two areas (37 individuals). The results of the RAPD and ISSR markers were highly congruent, supporting the reliability of the techniques used. Similarity was estimated using the Jaccard arithmetic complement index. A dendrogram was constructed using the unweighted pair group method with arithmetic mean cluster algorithm, and the robustness of the data was bootstrapped with 5000 replicates. A principal coordinate analysis was performed on the basis of Jaccard coefficients. The total genetic variation observed was 21%, corresponding to the variation between the populations, and 79% of the variation was observed within the populations.

Assessing change in quality of life using the Oral Health Impact Profile (OHIP) in patients with different dentofacial deformities undergoing orthognathic surgery: a before and after comparison.

Dentofacial deformities and their treatment have physical and psychological repercussions on quality of life (QOL). Seventy-four patients were evaluated preoperatively (T0) and at 4-6 months postoperatively (T1). Oral health-related QOL was assessed using the short form of the Oral Health Impact Profile (OHIP-14). There was a statistically significant reduction in the average overall OHIP-14 score between T0 (13.23±6.45) and T1 (3.26±4.19). In addition, there were significant decreases in all seven OHIP-14 domains. Class III patients benefited in all domains evaluated, while a significant improvement was seen only in the psychological disability domain for class I patients. Class II patients showed a significant benefit in all domains except the domain of functional limitation. With regard to the total sample (n=74) and class III patients (n=58), correlations between domains were identified for all domains. The same correlation was not identified for class I (n=5) and II (n=11) patients. The entire sample and class III patients showed significant improvements in OHIP-14 scores for all degrees of postoperative sensory disturbance in the upper and lower lips, except for patients with degree 5 (extreme) disturbance of the upper lip. Orthognathic surgical treatment had a positive impact on oral health-related QOL in the patients evaluated.

First record of larval Pseudoproleptus sp. (Nematoda: Cystidicolidae) in fish host.

Infective third-stage larvae of the cystidicolid nematode Pseudoproleptus sp. were found encapsulated in the mesentery of the freshwater fish Satanoperca jurupari Heckel (Cichlidae) from the Guamá River, close to the Amazon River Delta, Pará State, Brazil. The prevalence in fish (total body length 9-24 cm) examined from March 2009 to June 2010 (n=53) was 37%, with an intensity of 4-45 (mean 14±11) larvae per fish. The nematode larvae (body length 16.2-21.6mm), characterized by the cephalic end provided with a helmet-like cuticular structure having a thickened free posterior margin, were studied based on light and scanning electron microscopy. Fish play a role of paratenic hosts for this nematode species. This is the first record of a larval nematode of the genus Pseudoproleptus from fish, and the second record of a larval nematode belonging to Cystidicolidae in the Amazon and in the Neotropics. Additional larval specimens were found free in the stomach of only 0.9% Ageneiosus ucayalensis Castelnau (Auchenipteridae) examined (n=205). This finding can be considered as occasional parasitism.

Cytokine levels in serious cardiopathy of Chagas disease after in vitro stimulation with recombinant antigens from Trypanosoma cruzi.

The clinical manifestations of human Chagas disease are associated with distinct and complex host-parasite interactions that directly involve the host's immune system. In this study, we analysed the relationship between the production of intracytoplasmic cytokines after in vitro stimulation with the recombinant antigens CRA (cytoplasmatic repetitive antigen) or FRA (flagellar repetitive antigen) from Trypanosoma cruzi and the chronic cardiac or indeterminate clinical forms of Chagas disease. The chagasic patient groups consisted of 39 individuals, selected at the Chagas Disease Unit of the Oswaldo Cruz University Hospital, whom presented either a cardiac form without cardiac dilatation (CARD 1), cardiac form with cardiac dilatation (CARD 2) or indeterminate form (IND). Blood samples were obtained from these patients and cultured in the presence of CRA or FRA. The cytokines produced by lymphocytes and monocytes after antigen stimulation were analysed by flow cytometry. Our results showed that the IFN-γ and TNF-α, produced by CD8+ T lymphocytes after in vitro stimulation with CRA, differed among chagasic patients with CARD 1, CARD 2 or IND. We propose that these cytokines could be utilized as immunological markers for clinical cardiac forms of Chagas disease. In a prospective study of patients presenting IND and CARD 1, the assay performed in this paper could serve as a tool to monitor therapeutic interventions, thus improving the patient's quality of life.

Chagas' disease: IgG isotypes against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive antigens of Trypanosoma cruzi in chronic Chagasic patients.

The wide range of clinical Chagas' disease manifestations, of which heart involvement is the most significant, because of its characteristics, frequency and consequences, and lack of treatment and cure, justify research in this area. Specific immunoglobulin G (IgG) antibody subclasses have been associated with human Chagas' disease. Thus, in this study, the profile of IgG subclasses against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive T. cruzi-specific antigens was correlated with cardiac (CARD, n=33), cardiodigestive (CD, n=7), and indeterminate (IND, n=20) forms of Chagas' disease by indirect enzyme-linked immunosorbent assay (ELISA). IgG subclasses were detected in almost all Chagas patients studied. Nevertheless, only specific IgG2 isotype FRA was found with a significant statistical difference in CARD patients when compared to IND patients. This result suggests the potential use of this isotype for prognostic purposes, for monitoring the progression of chronic Chagas' disease, and for predicting the risk of CARD damage. This is important information, as it could help physicians to evaluate and manage the treatment of their patients. However, a follow-up study is necessary to confirm our result.

Parasitóides da família Pteromalidae (Hymenoptera: Pteromalidae) coletados em fezes de gado bovino em uma propriedade rural do município de Panamá, Goiás / Parasitoids of family Pteromalidae (Hymenoptera: Pteromalidae) collected in cattle dung in a rural property of the municipal district of Panamá, Goiás

The frequency 01 Pteromalidae species lound in Diptera pupae that were collected Irom cattle 'dung in Pandmá, State 01 Goiás, Brazil, between May and December 2003 was studied. The pupae were obtained by the jlotation method and were individually placed in gelatin capsules until the emergence 01 the adultjlies or their parasitoids. The overall percentage 01 parasitism was i4. 7. The percentage 01 parasitismpresented by the parasitoids Pachycrepoideus vindemmiae (Rondani), Spalangia cameroni Perkins,Spalangia drosophilae Ashmead, Spalangia endius Walker, Spalangia nigra Latrielle and Spalangia nigroaenea Curtis were i. 7, iA, 2.4, 0.7, 204 and 6. i, respectively.

Superparasitismo de spalangia nigroaenea curtis (hymenoptera: pteromalidae) em fezes bovinas no brasil / Superparasitism by spalangia nigroaenea curtis (hymenoptera: pteromalidae) in cyrtoneurina pararescita couri (diptera: muscidae) collected from bovine dung in brazil

RESUMO Este estudo relata a ocorrência de superparasitismo em pupas de Cyrtoneurina pararescita Couri (Diptera: Muscidae) pelo parasitóide Spalangia nigroaenea Curtis (Hymenoptera: Pteromalidae) em fezes bovinas em Itumbiara, Goiás, Brasil. Amostras de fezes foram coletadas em intervalos de duas semanas de sua exposição no campo, levadas para o laboratório para extração das pupas pelo método de flutuação. As pupas foram individualizadas em cápsulas de gelatina e mantidas até a emergência das moscas e/ou parasitóides. Foram coletadas duas pupas de C. pararescita, das quais de cada uma emergiram 2 parasitóides pertencentes a espécie S. nigroaenea. Este é o primeiro relato de superparasitismo de S. nigroaenea em pupas de C. pararescita em fezes bovinas no Brasil.

ABSTRACT This study reports the occurrence of superparasitism in pupae of Cyrtoneurina pararescita Couri (Diptera: Muscidae) by the parasitoid Spalangia nigroaenea Curtis (Hymenoptera: Pteromalidae) in bovine dung in Itumbiara, Goias, Brazil. Manure samples, collected at two intervals, were taken to the laboratory and the pupae were extracted by water flotation. The pupae were placed in gelatin capsules until the emergence of flies or their parasitoids. Parasitoids of the species S. nigroaenea emerged from two of the pupae. This is the first report of superparasitism by S. nigroaenea in pupae of C. pararescita in bovine dung in Brazil.

Parasitóides da família Pteromalidae (Hymenoptera: Pteromalidae) coletados em fezes de gado bovino em uma propriedade rural do município de Panamá, Goiás / Parasitoids of family Pteromalidae (Hymenoptera: Pteromalidae) collected in cattle dung in a rural property of the municipal district of Panamá, Goiás

The frequency of Pteromalidae species found in Diptera pupae that were collected from cattle dung in Panamá, State of Goiás, Brazil, between May and December 2003 was studied. The pupae were obtained by the flotation method and were individually placed in gelatin capsules until the emergence of the adult flies or their parasitoids. The overall percentage of parasitism was 14.7%. The percentage of parasitism presented by the parasitoids Pachycrepoideus vindemmiae (Rondani), Spalangia cameroni Perkins, Spalangia drosophilae Ashmead , Spalangia endius Walker, Spalangia nigra Latrielle and Spalangia nigroaenea Curtis were 1.7%, 1.4%, 2.4%, 0.7%, 2.4% and 6.1%, respectively.(AU)

Occurrence of Leishmania donovani parasitemia in plasma of infected hamsters.

Intracardiac transfusion of plasma, mononuclear cell fraction and blood of infected hamster donors induced visceral leishmaniasis in normal hamster receptors. At the moment of transfusion, the donors already showed all the typical signs of the disease: ascites, cachexia, as well as splenomegaly and a high parasite load in the spleen and liver. All transfused hamsters developed typical visceral leishmaniasis between 90 and 120 days, indicating that all blood products were infectious. Transfusion of the mononuclear cell fraction induced the highest values of parasitic load (spleen, 766 Leishman Donovan Units (LDU); liver, 2650 LDU), splenomegaly and hepatomegaly (spleen-liver/body relative weight: 1.130 and 6.870, respectively). Animals that received the plasma fraction also developed visceral leishmaniasis, showing similar parasitic load (spleen, 107 LDU; liver, 220 LDU) and spleen-liver/body relative weight (1.005 and 6.35, respectively) than those transfused with whole blood. The finding of typical Leishmania donovani infection in animals transfused with plasma demonstrates the possibility of the extracellular location of parasites, free in this blood fraction deprived of red and white blood cells. Fluorescence-assisted cell sorter analysis (FACS) of plasma showed the presence of particles corresponding in size to amastigotes, which fluoresced strongly with the serum of a patient with Kala-azar (73%), but not with normal serum.

Acute retrovirus syndrome among prospectively identified homosexual men with incident HIV infection in Brazil. Projecto Praça Onze Study Group.

BACKGROUND: Symptoms associated with HIV infection are common among HIV seroconverters, but the acute retroviral syndrome (ARS) is a diagnostic challenge because of the absence of a sensitive and specific case definition. We conducted an analysis of HIV seroconverters in Projeto Praça Onze, a HIVNET HIV seroincidence study among homosexual men in Rio de Janeiro. METHODS: Information from study subjects enrolled in Projeto Praça Onze who were documented HIV seroconverters were compared with nonseroconverters. At each semiannual study visit, participants were asked about HIV seroconversion symptoms and sexually transmitted diseases (STDs) during the preceding 6 months. All information was collected before the laboratory evaluation. A classification tree analysis was used to identify an ARS case definition, first using clinical information and then after including risk factor data for seroconversion in our cohort. RESULTS: As of July 1998, 674 volunteers were enrolled and 34 of these seroconverted; information was available for 33 of these. Among the seroconverters, 11 (34%) denied any symptoms, and 22 (66%) reported one or more symptoms, the most common of which were fever (25% of seroconverters versus 7% of nonseroconverters; p <.01), night sweats (9% versus 2%, respectively; p =.05), incapacitating disease (ID) for >/=3 days (27% versus 7%, respectively; p <.001), and weight loss of >/=2 kg (21% versus 9%, respectively; p =.05). STDs were more common in seroconverters (gonorrhea: 9% versus 1%, respectively; p <.01 and condyloma: 9% versus 3%, respectively; p =. 08). The first case definition was ID for >3 days, fever, pharyngitis, and myalgia (seroconverters, 3 of 32, versus nonseroconverters, 2 of 640). The second case definition was was ID for >3 days, anti-core hepatitis b-positive, and age <21 years (seroconverters: 6 of 32 versus nonseroconverters 4 of 640). The sensitivity and specificity for the first and second case definitions were: 9.4%, 99.4%, and 18.8%, 99.8%, respectively. CONCLUSIONS: Among HIV seroconverters, symptoms consistent with ARS were common. We were unable to identify a sensitive case definition that could be used as a screening tool. Although the clinical case definition was not validated, the specificity of our case definitions was high, suggesting that subjects within this HIV risk group who fulfill the case definition should be tested for HIV.

Identification of a high-risk heterosexual population for HIV prevention trials in Rio de Janeiro, Brazil. Projeto Praço Onze Study Group.

The study of interventions to prevent HIV transmission requires access to populations with a high rate of HIV transmission. We estimated HIV incidence among heterosexual males and females who were seen at an HIV testing site in Rio de Janeiro, Brazil. Stored sera from individuals who visited the site between March and December 1998 were analyzed using the sensitive/less sensitive (S/LS) assay and a chart abstraction was performed. During the study period, 6353 serum samples were tested. Of those tested, 1203 were found to be HIV-seropositive or indeterminate, of which 1050 (87%) remained available for further testing. In addition, 84 serum samples, representing 63 adults, were found to produce results suggesting early HIV infection. Of these, 14 were heterosexual and female (median age, 38 years), and 19 were heterosexual and male (median age, 25 years). The estimated HIV seroincidence was 1.9 (95% confidence limits (CL), 0.9%-3.9%) and 2.8 (95% CL, 1.4%-5.3%) per 100 person-years among heterosexual women and men, respectively. A survey on willingness to participate in future placebo-controlled HIV vaccine trials in this population indicated that 54.5% and 53.9% of heterosexual women and men, respectively, indicated that they would definitely be willing to participate. We have identified a heterosexual population in Rio de Janeiro with a high rate of HIV transmission willing to participate in placebo-controlled vaccine trials. This study demonstrates the usefulness of the newly described S/LS assay, which allows one to estimate HIV incidence from single serum specimens.

Effect of antiretroviral therapy on HIV shedding in semen.

BACKGROUND: The effect of antiretroviral therapy on seminal HIV shedding in the community remains unknown. OBJECTIVE: To evaluate the effect of antiretroviral therapy on HIV shedding in semen. DESIGN: Prospective cohort study. SETTING: University hospital in Rio de Janeiro, Brazil. PATIENTS: 93 HIV-infected men. INTERVENTION: Antiretroviral therapy as prescribed by each patient's physician. MEASUREMENT: HIV RNA in semen and blood plasma before and after introduction of therapy. RESULTS: At baseline, HIV RNA was detected in 69 semen samples (74%) and 89 blood samples (96%). Six months after introduction of therapy, HIV RNA was detected in 29 semen samples (33%) and 33 blood samples (38%). The mean reduction in levels of HIV RNA in semen at 6 months was 1.65 log10 units. CONCLUSIONS: Antiretroviral therapy reduces shedding of HIV in semen, which probably in tum reduces HIV transmissibility. However, a substantial proportion of patients may still be infectious and may have drug-resistant strains of the virus.

Incident HIV infection in a high-risk, homosexual, male cohort in Rio de Janeiro, Brazil.

An HIV seroincidence study was conducted to identify a high-risk population for HIV prevention trials. Inclusion criteria were male gender, homosexual behavior, age between 18 and 50 years, and negative HIV serostatus; 862 study subjects were screened and 753 were enrolled and observed during follow-up for a mean of 1.5 years. In this population, 34 people had HIV seroconversions for an overall annual seroincidence of 3.1% (95% confidence interval [CI], 2.1%-4.1%). Among study subjects <20 years old, annual incidence was 8.4% (95% CI, 1.7%-15%). Independent risk factors for seroconversion were age <25 years (p = .01), hepatitis B core antibody seropositivity (p > .01), sex at first encounter in the preceding 6 months (p = .11), and a history of gonorrhea or condyloma in the 6 months before seroconversion (p = .04 and p = .08, respectively). At enrollment, 85% of the eventual seroconverters said they would participate in a vaccine trial; all agreed to participate when told there would be a placebo arm. Follow-up rates were 97%, 91%, and 88% at 6, 12, and 18 months, respectively. The HIV-1 subtype was B for each of the first 17 seroconverters. These data demonstrate the suitability of this cohort for HIV prevention trials, based on high HIV incidence and retention rates, and a willingness to participate in such trials.