Decomposition of ground biomass of secondary forest and yield of annual crops in no tillage

ABSTRACT The objective of this work was to evaluate the dynamics of decomposition process of chopped secondary forest system, previously enriched with legumes Inga velutina Willd. and Stryphnodendron pulcherrimum (Willd.) Hochr. and the contribution of this process to the nutrient input to the cultivation of corn and bean under no-tillage. The experimental design was a randomized block, split plot with four replications. The plots were two species (I. velutina and S. pulcherrimum) and the subplots were seven times of evaluation (0, 7, 28, 63, 189, 252, 294 days after experiment installation). There was no difference (p ≥ 0.05) between the secondary forest systems enriched and no interaction with times for biomass waste, decomposition constant and half-life time. The waste of S. pulcherrimum trees had higher (p < 0.05) C/N ratio than that I. velutina. However, this one was higher (p < 0.05) in lignin content. Nevertheless, the dynamics of residue decomposition was similar. The corn yield was higher (p < 0.05) in cultivation under I.velutina waste. Meanwhile, the beans planted after corn, shows similar (p > 0.05) yield in both areas, regardless of the waste origin.

Carbohydrates Concentration in leaves of potato plants affected by nitrogen fertilization rates

ABSTRACT At poor conditions of nitrogen (N) in the soil, potato plants may accumulate starch in leaves and be indicative of N nutritional stress. The objective of this work was to determine the effects of N rates (0, 50, 100, 200 and 300 kg ha-1 of N) on the concentrations of carbohydrates (total soluble sugars-TSS, reducing sugars-RS, non-reducing sugars-NRS and starch) in the fourth leaf (FL) of two potato cultivars (Asterix and Atlantic) and their critical levels (CL) associated to the N fertilization rate necessary to obtain the maximum physical (MPE) and economic (MEE) efficiency of tubers. A randomized block design with four replications was used in both experiments. On day 21 after plant emergence, four FL were collected from four plants. Potatoes plants fertilized with low rates of N accumulated less TSS in leaves than those properly fertilized. The opposite occurred with content of starch. The cultivars showed similar responses to five doses of N in relation to contents of starch and TSS. However, the response to the increase in doses of N for RS, NRS and Starch/NRS is cultivar-specific. The correlations between contents of RS, NRS and Starch/NRS with the starch and TSS were dependent on the potato cultivar.

Growth of sugar cane varieties under salinity

ABSTRACT Large salty areas in the Brazilian semi-arid region have limited farming in Northeastern Brazil. One example is the sugar cane cultivation, which reinforces the need of selecting varieties that are more tolerant to salinity. The objective of this study was to evaluate the effect of salinity on growth of ten varieties of sugar cane. The experiment was conducted in a greenhouse, set in the experimental field of Embrapa Semiárido, in Petrolina, Pernambuco State. The experimental design was randomized blocks arranged in a 6 X 10 factorial arrangement, comprised of six levels of salinity (0, 1.0, 2.0, 4.0, 6.0 and 8.0 dS m-1) and ten sugar cane varieties (VAT 90212; RB 72454; RB 867515; Q 124; RB 961003; RB 957508; SP791011; RB 835089; RB 92579 and SP 943206). Salt levels of irrigation water were obtained by adding NaCl, CaCl2.2H2O and MgSO4.7H2O to achieve an equivalent ratio among Na:Ca:Mg of 7:2:1. Sixty days later, plant height, stem diameter (base), number of leaves, stalks and sprouts, leaf area and fresh and dry mass of the aerial part and roots were all measured. The varieties of sugar cane showed similar responses for growth reduction as soil salinity increases, being considered moderately sensitive to salinity.

Outbreak of persistent cutaneous abscesses due to Mycobacterium chelonae after mesotherapy sessions, Lima, Peru

Outbreaks of rapidly growing mycobacteria have been occasionally described. The article reports an outbreak of cutaneous abscesses due to Mycobacterium chelonae following mesotherapy in Lima, Peru. From December 2004 through January 2005, 35 subjects who had participated in mesotherapy training sessions presented with persistent cutaneous abscesses. Thirteen (37%) of these suspected cases consented to underwent clinical examination. Skin punch-biopsies were collected from suspicious lesions and substances injected during mesotherapy were analyzed. Suspected cases were mainly young women and lesions included subcutaneous nodules, abscesses and ulcers. Mycobacterium chelonae was isolated from four patients and from a procaine vial. In conclusion, it is important to consider mesotherapy as a potential source of rapidly growing mycobacteria infections.

A prospective study of cat-scratch disease in Lima-Peru

Cat-Scratch Disease (CSD) is a benign lymphadenitis that may progress to severe or recurrent forms, and it is occasionally associated with morbidity. Between January of 1998 and March of 1999, forty-three suspected CSD patients were assessed in the Hospital Cayetano Heredia and the Instituto de Salud del Niño, in Lima, Peru. Twelve patients had a confirmed diagnosis, 8 of whom were women, and the mean age was 10 years old. The majority (53%) of the cases were encountered in the summer. All patients reported having had contact with cats. Fever, malaise, lymphadenopathy and skin lesions were the most frequent clinical features. Twelve patients had indirect immunofluorescence antibody test titers of between 1/50 and 1/800 for Bartonella henselae and Bartonella clarridgeiae. Two lymph node biopsies were histologically compatible with CSD. No positive blood cultures could be obtained. This is the first Peruvian prospective study able to identify B. henselae and B. clarridgeiae in pediatric patients.

Cutaneous anthrax in Lima, Peru: retrospective analysis of 71 cases, including four with a meningoencephalic complication

Anthrax is a zoonosis produced by Bacillus anthracis, and as an human infection is endemic in several areas in the world, including Peru. More than 95% of the reported naturally acquired infections are cutaneous, and approximately 5% of them can progress to meningoencephalitis. In this study we review the clinical and epidemiological characteristics of the patients with diagnosis of cutaneous anthrax evaluated between 1969 and 2002 at the Hospital Nacional Cayetano Heredia (HNCH) and the Instituto de Medicina Tropical Alexander von Humboldt in Lima, Peru. Seventy one patients were included [49/71 (69%) of them men], with a mean age of 37 years. The diagnoses were classified as definitive (44%) or probable (56%). The most common occupation of the patients was agriculture (39%). The source of infection was found in 63 (88.7%) patients. All the patients had ulcerative lesions, with a central necrosis. Most of the patients (65%) had several lesions, mainly located in the upper limbs (80%). Four patients (5.6%) developed meningoencephalitis, and three of them eventually died. In conclusion, considering its clinical and epidemiological characteristics, cutaneous anthrax must be included in the differential diagnosis of skin ulcers. A patient with clinical suspicion of the disease should receive effective treatment soon, in order to avoid neurological complications which carry a high fatality rate.

Effect of stalk and leaf extracts from Euphorbiaceae species on Aedes aegypti (Diptera, Culicidae) larvae

The objective of this study was to evaluate the larvicidal activity of essential oil aqueous solutions (hydrolates) obtained by steam distillation of stalks and leaves of Croton argyrophylloides, Croton nepetaefolius, Croton sonderianus and Croton zehntneri against Aedes aegypti larvae. Twenty-five larvae of third instar were placed in plastic beckers, containing the hydrolates (50 mL), in a four repetitions scheme. Water was used as control and the number of dead larvae was counted after 24 hours. The data obtained were submitted to Variance Analysis and Tukey test. Significant differences were observed among the hydrolates from different species and from different parts of each plant (p < 0.001). The hydrolates of stalk and leaf from C. nepetaefolius and C. zehntneri and leaf hydrolate of C. argyrophylloides presented 100% mortality against larvae. The compounds present in C. zenhtneri and C. nepetaefolius are oxygenated phenylpropanoids that are more soluble in water than the monoterpenes and sesquiterpenes detected in the oils of C. argyrophylloides and C. sonderianus. This study showed that all species analyzed presented compounds with larvicidal properties, with differences between each plant parts.

Frequency of eosinophilia and risk factors and their association with Toxocara infection in schoolchildren during a health survey in the north of Lima, Peru

During a health survey in a primary school from the district of Carabayllo (North of Lima, Peru), 200 schoolchildren (96 male and 104 female between five to 12 years old) were randomly selected and divided in two groups (as positive or negative group), according to the serologic result of the Toxocara ELISA test from a total population of 646 schoolchildren. All children were analyzed by hematologic tests to determinate the frequency of eosinophilia and leukocytosis. Additionally, all clinical and epidemiological data were also analyzed to determine their association with toxocariasis. From group of children with positive serology, 40% had some type of eosinophilia in contrast to 19% of children with negative serology, and their association was statistically significant (OR = 2.84, p < 0.001). From all signs and symptoms evaluated, only 'dry cough' was more frequent and statistically significant in the positive serology group (OR = 2.79, p < 0.001). Almost all risk factors evaluated were highly frequent and statistically associated to the positive serology. In conclusion, the presence of eosinophilia and the risk factors evaluated in this population were frequently associated to human toxocariasis.

Seroprevalence of human toxocariasis in Andean communities from the Northeast of Lima, Peru

The aim of this study was to assess the seroprevalence of human toxocariasis in three Andean communities from the Northeast of Lima, Peru. A total of 303 subjects including children and adults were studied and blood samples were collected to detect anti-Toxocara antibodies by ELISA-IgG test and by hematological examination; stool samples were collected also for parasitological examination. The overall seroprevalence of toxocariasis observed in the total population was 20.46%, with a significant high proportion in children from one to 10 years old (p = 0.034). Among the subjects with positive serology, 32.26% of them had respiratory disturbances, 22.58% hepatomegaly, 17.74% ocular signs or symptoms, 14.51% abdominal pain, 9.68% neurological involvement, and 4.84% cutaneous signs, but none of these clinical features were associated to a positive serology by multivariate analysis. Furthermore, 79.03% of seropositive subjects also harbored at least one intestinal parasite, which was associated to a positive serology (p < 0.05). The presence of pets within the houses, a previous history of pica or geophagia and the use of public places were also present in this population, but only the latter was associated to the serology (p < 0.05). In conclusion, clinical, serological, and epidemiological evidences for larval Toxocara infection were found in the studied population.

ISOLATION AND MOLECULAR IDENTIFICATION OF POTENTIALLY PATHOGENIC Escherichia coli AND Campylobacter jejuni IN FERAL PIGEONS FROM AN URBAN AREA IN THE CITY OF LIMA, PERU

SUMMARY Feral pigeons (Columbia livia) live in close contact with humans and other animals. They can transmit potentially pathogenic and zoonotic agents. The objective of this study was to isolate and detect strains of diarrheagenic Escherichia coli and Campylobacter jejuniof urban feral pigeons from an area of Lima, Peru. Fresh dropping samples from urban parks were collected for microbiological isolation of E. coli strains in selective agar, and Campylobacterby filtration method. Molecular identification of diarrheagenic pathotypes of E.coliand Campylobacter jejuni was performed by PCR. Twenty-two parks were sampled and 16 colonies of Campylobacter spp. were isolated. The 100% of isolates were identified as Campylobacter jejuni. Furthermore, 102 colonies of E. coli were isolated and the 5.88% resulted as Enteropathogenic (EPEC) type and 0.98% as Shiga toxin-producing E. coli (STEC). The urban feral pigeons of Lima in Peru can act as a reservoir or carriers of zoonotic potentially pathogenic enteric agents.

Parasitismo natural de ovos de triatomíneos por Telenomus fariai lima, 1927 no laboratório

Em novembro/89 verificou-se que o insetário do Centro de Estudos Emmanuel Dias - Bambuí/MG apresentava alta infestação pelo micro himenóptero Telenomus fariai. Em 529 ovos de Panstrongylus megistus e Triatoma vitticeps examinados, 375 (70,9%) apresentavam 1043 exemplares de T. fariai, sendo 955 (91,4%) fêmeas e 90 (8,6%) machos. A seguir, verificou-se também oparasitismo de ovos de Triatoma infestans, e ausência de infestação de ovos de Rhodnius neglectus. As médias de parasitóide por ovo observadas foram de 7,9 em P. megistus; 8,7 em T. vitticeps e 10 em T. infestans. A importância do relato deve-se à possibilidade da infestação de colônias mantidas para fins de pesquisa a partir da introdução em insetários de ovos procedentes do campo, com o estabelecimento de altas taxas de infestação e acentuado declínio da criação. O isolamento e a eliminação dos parasitóides pelo manejo dos ovos parasitados e vedação dos frascos do insetário com tecido de malha estreita (em tomo de 0,25mm) mostraram-se eficientes no controle do T. fariai.

Identificação de um novo foco de esquistossomose mansoni (município de Nova Lima, MG, Brasil)

E relatada a detecção de um novo foco de transmissão da esquistossomose mansoni, no município de Nova Lima (região metropolitana de Belo Horizonte, MG, Brasil). Na localidade conhecida por Banqueta do Bananal, no bairro da Boa Vista, foram capturados 356 exemplares de Biomphalaria glabrata dos quais 30 (8,4%) estavam infectados. Dos 162 moradores submetidos ao exame de fezes, 91 eliminavam ovos de Schistosoma mansoni, apresentando uma prevalência de 56,0%. A ação conjunta dos moradores e da Prefeitura Municipal levou à eliminação do foco, sendo esta uma solução poucas vezes conseguida em situações semelhantes.