Growth promotion in wheat seedlings altered by conditions in the culture medium of Azospirillum brasilense.

Agricultural management using technologies that help farmers increase productivity and reduce production costs must be promoted to ensure agricultural sustainability. The objective of the study was to achieve the pH effect of growth solution, chemical treatment, use of osmoprotector additive and mineral nitrate presence, on the activity of growth promoting bacteria, Azospirillum brasilense, and its effects on the physiological quality of seeds and wheat seedling growth. The first experiment evaluated the physiological quality of seeds and the second experiment was divided into four, evaluating the growth of wheat seedling in a hydroponic system. The experiments were prolonged in a very randomized design, with four replications. The physiological quality of the seeds was evaluated by germination tests, first germination count, length of the shoot and root and dry mass of the shoot and root. Initial growth was evaluated by quantifying the dry mass of the leaf shoot and root and the root system intervals. The pH of the solution and the presence of nitrogen did not influence the effects of inoculation of the A. brasilense bacteria. With the use of chemical treatment and osmoprotective additive, A. brasilense had no effect on the growth of wheat seedlings.

Frozen spatial coherence.

Inspired by the concept of coherent frozen waves, this paper introduces one possible theoretical framework of its partially coherent version, a frozen spatial coherence, in which a desired two-point correlation structure of an optical field is created on the propagation axis by superposing partially coherent zero-order Bessel beams. It is shown that the cross-spectral density can be given a description in terms of a two-dimensional Fourier series, analogous to the one-dimensional approach of coherent frozen waves. The formalism is applied to the design of a partially coherent field which is highly coherent only if the pair of points in the propagation axis belong to a predetermined and finite range and highly incoherent outside that range.

Detection and quantification of hepatitis E virus in the absence of IgG and IgM anti-HEV in HIV-positive patients.

AIMS: To improve RT-qPCR with an internal control and a synthetic standard curve to detect HEV in HIV co-infected patients. METHODS AND RESULTS: A single-stranded RNA (ssRNA) and a double-stranded DNA (dsDNA) synthetic curve were designed, compared to the international reference panel for HEV genotypes, and tested to quantify and detect a reference panel for HEV genotypes. The detection limit of the RNA synthetic curve (50 copies per ml) was better than the DNA synthetic curve (100 copies per ml) and the WHO standard curve (250 copies per ml). Then, 280 serum samples from HIV-positive patients were tested for HEV RNA, which was detected in 3·6% of serum samples. The viral load ranged from 2 × 102 copies per ml to 4·78 × 108 copies per ml. HEV IgM/IgG antibodies were not detected in the RNA-positive patients. Sequencing analysis of HEV showed that the virus belongs to genotype 3 (HEV GT3). CONCLUSIONS: Real-time PCR was a useful tool to estimate co-infection with HEV/HIV, even in patients with low viral loads and undetectable anti-HEV IgG and IgM antibodies. SIGNIFICANCE AND IMPACT OF THE STUDY: Hepatitis E virus genotype 3 (HEV GT3) has been associated with silent chronic hepatitis and cirrhosis in HIV-positive subjects worldwide, but there is a lack of data on this co-infection in Brazil.

Seroprevalence of hepatitis E antibodies in a population of recyclable waste pickers in Brazil.

BACKGROUND: Hepatitis E virus (HEV) infection represents an important cause of acute viral hepatitis. Selective waste collection is a widespread activity carried out by the urban poor, and recyclable waste pickers have a lifestyle that makes this group highly vulnerable to unfavorable socio-economic and environmental factors. To date, the epidemiology of HEV infection in this population remains unknown. OBJECTIVES: To assess the seroprevalence of hepatitis E-specific antibodies in a population of recyclable waste pickers in Brazil. STUDY DESIGN: Between April 2010 and May 2011, a cross-sectional study was conducted among recyclable waste pickers from all 15 recycling cooperatives in Goiânia City, Central Brazil. The participants were tested for serological markers indicative of HEV infection. RESULTS: Of 432 individuals asked to participate in the survey, 431 (99.8%) agreed to participate. Twenty-four of 431 participants were anti-HEV IgG positive by ELISA. Of these, 22 were confirmed positive by immunoblot, resulting in an anti-HEV IgG prevalence of 5.1% (95% CI: 3.4-7.6). In addition, four individuals were anti-HEV IgM positive by ELISA. Of these, three (0.7%; 95% CI: 0.4-2.4) were confirmed anti-HEV IgM positive by immunoblot, but were HEV RNA negative. One was concurrently positive for anti-HEV IgG. Only age>40 years was independently associated with the presence of anti-HEV. CONCLUSIONS: These findings demonstrated that the prevalence of HEV antibodies among recyclable waste pickers in Central Brazil is relatively low and increased with age.

Hepatitis E virus infection in Latin America: a review.

Data reported during recent years reveal the complex picture of the epidemiology of hepatitis E virus (HEV) infection in Latin America. Whereas in countries like Argentina and Brazil is almost identical to the characteristic of most countries from North America and Europe, HEV in the Caribbean and Mexico involves the water-borne, non-zoonotic viral genotypes responsible for epidemics in Asia and Africa. Nevertheless, Latin America has been considered a highly endemic region for hepatitis E in the scientific literature, a generalization that ignores the above complexity. In addition, reports from isolated Amerindian communities, which display well known, important and very specific epidemiological features for hepatitis B and D virus infections are neither taken into account when considering the epidemiology of hepatitis E in the region. This review updates compilation of the available information for the HEV infection, both among humans and other mammals, in Latin America, discusses the strengths and the weaknesses of our current knowledge, and identifies future areas of research.

Óleo essencial de Baccharis trimera (Less. ) DC. sobre o potencial fisiológico de sementes de feijão caupi / The essential oil effects of Baccharis trimera (Less. ) DC. on the physiological potential of cowpea bean seeds

O presente trabalho teve como objetivo avaliar o efeito alelopático do óleo essencial de plantas de carqueja, Baccharis trimera (Less.) DC., sobre a germinação de sementes de feijão Vigna unguiculata (L.) Walp. Foi avaliado o efeito do óleo essencial de B. trimera sobre V. unguiculata nas dosagens 20 μL, 15 μL, 10 μL, 5 μL e testemunha. A qualidade fisiológica das sementes foi determinada pela porcentagem de emergência, velocidade de emergência e índice de velocidade de emergência. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 5 x 2 com cinco repetições. Não foi observado efeito inibidor do óleo essencial de B. trimera na germinação de sementes de feijão caupi, caracterizando-se como de efeito alelopático benéfico. De acordo com os resultados obtidos, o óleo essencial de B. trimera revelou-se eficiente na manutenção da viabilidade dessas sementes.

This research aimed to evaluate the allellopathic effect of essential oils of the Baccharis trimera (Less.) DC. plants on the seeds germination of cowpea Vigna unguiculata (L.) Walp. The effect of B. trimera essential oil on V. unguiculata was evaluated at levels of 20 μL, 15 μL, 10 μL, 5 μL and control. The physiologic quality of the seeds was determined by percentage emergence, the rate of speed emergence and speed emergence index. The data analysis was carried out using an entirely randomized design, in a 5 x 2 factorial scheme with five repetitions. An inhibitory effect of B. trimera essential oil on bean seeds germination was not observed, which is characterized as a beneficial allelopathic effect. Based on the results, the B. trimera essential oil proved efficient in the viability maintenance of these seeds.

Viabilidade de sementes de feijão caupi após o tratamento com óleo essencial de citronela (Cymbopogon winterianus Jowitt) / Viability of Vigna unguiculata bean seeds treated with essential oil of Java grass (Cymbopogon winterianus Jowitt)

O tratamento de sementes com óleos essenciais é um método alternativo que auxilia o manejo integrado de pragas. O objetivo deste trabalho foi avaliar a influência do tratamento de sementes de feijão Vigna unguiculata (L.) Walp. com o óleo essencial de citronela (Cymbopogon winterianus Jowitt). Foi avaliado o efeito do óleo essencial de C. winterianus sobre V. unguiculata nas dosagens 20 µL, 15 µL, 10 µL, 5 µL e testemunha. A qualidade fisiológica das sementes foi determinada pela porcentagem de emergência, velocidade de emergência e índice de velocidade de emergência. A análise dos dados foi realizada no delineamento inteiramente casualizado, disposto em esquema fatorial 5 x 2 com cinco repetições. As sementes fumigadas apresentaram diferenças estatísticas entre os parâmetros avaliados em relação à testemunha. O óleo essencial de citronela revelou potencialidade alelopática sobre a germinação de sementes de feijão que variou de acordo com a concentração do óleo.

Seed treatment with essential oils is an alternative method tool in integrated pest management. The objective of this study was to evaluate the effect of treating Vigna unguiculata (L.) Walp. bean seeds with essential oil of Java grass (Cymbopogon winterianus Jowitt). The effect of C. winterianus essential oil on P. vulgaris was evaluated at levels of 20 µL, 15 µL, 10 µL, 5 µL and control. The physiologic quality of the seeds was determined by percentage emergence, speed emergence and speed emergence index. The data analysis was carried out using an entirely randomized design, in a 5 x 2 factorial scheme with five repetitions. The fumigated bean seeds showed the statistics differences among the analyzed parameters when was compared with the no treated check. The essential oil of Java grass revealed allelopathic potentiality on bean seed germination which varied according to the oil concentration.

The use of dried blood spots for assessing antibody response to hepatitis A virus after natural infection and vaccination.

During recent years, vaccination against hepatitis A has been implemented in several countries. It is expected that the increase in mass vaccination against hepatitis A will eventually result in a decreased prevalence of anti-HAV antibodies in the general population. For this reason, a suitable clinical sample for diagnosis of hepatitis A must be sufficiently sensitive to enable detection of lower antibodies titers. In this study, the feasibility of using dried blood spots (DBS) was assessed for the detection of anti-HAV antibodies after a natural infection and vaccination. Seventy-four DBS and paired plasma samples were obtained from a group of college students for a cross-sectional hepatitis A seroepidemiological study. Forty-six students seronegative for anti-HAV were selected randomly and immunized with an inactivated hepatitis A vaccine using an 0-6 month schedule. Seroconversion was monitored in paired plasma and DBS samples 6 months after the first dose followed by a period of 8 and 24 months after the second dose. A strong correlation between OD/CO rates of paired plasma and DBS samples for the detection of anti-HAV was observed. The sensitivity and specificity of the DBS compared with plasma for the detection of anti-HAV antibodies after natural infection was 100%. The sensitivity of DBS in samples collected 24 months after the second dose of hepatitis A vaccine was 95.4%. The results showed that DBS samples can be used for the detection of anti-HAV antibodies both after natural infection or vaccination.

Kinetics of hepatitis A virus replication in vivo and in vitro using negative-strand quantitative PCR.

The replication of hepatitis A virus (HAV) is via a complementary negative-strand RNA. Each negative strand may serve as a template for the synthesis of many positive strands. The aim of this study was to detect the intermediate replicative (negative strand) of HAV in order to monitor its replication in vitro and in vivo. Real-time polymerase chain reaction (PCR) was standardized to detect the intermediate replicative of HAV in cell culture and liver from non-human primates infected experimentally. HAV primers from the 5' non-translated region and VP3 were used in the cDNA synthesis of negative-strand RNA. The negative strand was detected in the infected cell lines and liver by highly strand-specific rTth recombinant Thermus thermophilus DNA polymerase reverse transcription followed by quantitative PCR. The results indicate that the negative-strand HAV RNA can be detected in vivo and in vitro. This model is an approach for assessing the dynamic patterns of replication and should represent a valuable tool for the monitoring of HAV replications in cell cultures and for the evaluation of experimental infections in animal models.

Leishmania infantum-induced primary and challenge infections in rhesus monkeys (Macaca mulatta): a primate model for visceral leishmaniasis.

Visceral leishmaniasis (VL) was experimentally induced in rhesus macaques (Macaca mulatta) by intravenously inoculating 2 x 10(7)amastigotes/kg of body weight of Leishmania infantum. The macaques developed a systemic disease showing characteristic features of human VL such as fever, diarrhoea, body weight loss, anaemia, hypergammaglobulinaemia and transient lymphocytosis, as well as lymph node, liver and/or spleen enlargement. Nine weeks after infection, one primate showed pronounced weight loss, became moribund and was euthanized. The necropsy findings included granulomas composed of parasite-containing macrophages, lymphocytes and plasma cells in the liver, spleen and lymph nodes. The remaining macaques had a sustained course of infection but developed a mild-to-moderate illness that subsequently showed evidence of self-cure. Of note, pathological findings included a typical cell-mediated immunity-induced granulomatous reaction that had an effect on the control of parasite replication. All infected monkeys responded with increased production of anti-Leishmania-specific IgG antibodies. Despite the fact that clinical resistance to L. infantum was not consistently associated with a parasite-specific cell-mediated immune response, drug-cured macaques from the primary infection acquired immunity to homologous re-infection. These findings point to the feasibility of using the L. infantum macaque model for pre-clinical evaluation of novel chemotherapeutics or vaccine candidates for human VL.