OBJECTIVES: Evidence suggests that infection or inflammation is a major contributor to early spontaneous preterm birth (sPTB). Therefore, this study aimed to investigate the development and causes of maternal infection associated with maternal and neonatal outcomes in women with sPTB. METHODS: This was a secondary analysis of a multicenter cross-sectional study with a nested case–control component, the Brazilian Multicentre Study on Preterm Birth (EMIP), conducted from April 2011 to July 2012 in 20 Brazilian referral obstetric hospitals. Women with preterm birth (PTB) and their neonates were enrolled. In this analysis, 2,682 women undergoing spontaneous preterm labor and premature pre-labor rupture of membranes were included. Two groups were identified based on self-reports or prenatal or hospital records: women with at least one infection factor and women without any maternal infection (vulvovaginitis, urinary tract infection, or dental infection). A bivariate analysis was performed to identify potential individual risk factors for PTB. The odds ratios (ORs) with their respective 95% confidence intervals were calculated. RESULTS: The majority of women with sPTB fulfilled at least one criterion for the identification of maternal infection (65.9%), and more than half reported having urinary tract infection during pregnancy. Approximately 9.6% of women with PTB and maternal infection were classified as having periodontal infection only. Apart from the presence of a partner, which was more common among women with infectious diseases (p=0.026; OR, 1.28 [1.03-1.59]), other variables did not show any significant difference between groups. CONCLUSION: Maternal infection was highly prevalent in all cases of sPTBs, although it was not clearly associated with the type of PTB, gestational age, or any adverse neonatal outcomes.

The development of drug delivery systems for photodynamic therapy (PDT) is increasingly demanded due to the hydrophobicity presented by most of photosensitizers molecules. Bacterial cellulose (BC), a highly pure cellulose produced by bacteria, possesses the essential features for applications in drug delivery systems, such as large surface area and excellent loading capacity. BC membranes prepared containing a photosensitizer, chloroaluminum phthalocyanine (ClAlPc), were tested aiming applications as a drug delivery system for PDT skin cancer protocols. BC membranes production was optimized regarding thickness and optical transmission. Thinner membranes lead to higher relative incorporation efficiencies. Skin permeation and retention in vitro tests were performed by using pig's ears as a skin model. ClAlPc was retained at stratum corneum and epidermis/dermis, showing adequate properties for topical administration of ClAlPc. Photophysical studies showed that singlet oxygen production was not affected for ClAlPc compartmentalized in the BC array. BC-ClAlPc membranes did not present cytotoxic effects in vitro.

Introduction. In the year 2009, the World Health Organization declared the Influenza A H1N1 virus as a pandemic. It has been reported that the radiographic pattern in chest x-ray may predict the clinical outcome in patients affected. Objective. To describe the chest x-ray fndings in pediatrics patients with confrmed diagnosis of Influenza H1N1 respiratory infection and its correlation with clinical evolution. Population and methods. A retrospective, analytic and descriptive study of 47 pediatric inpatients with confirmed diagnosis of H1N1 influenza who had available chest x-ray was performed. Medical records were reviewed for underlying medical conditions and patient's outcome. Results. 94% of patients had abnormal x-ray. Consolidation and ground-glass opacities had signifcantly higher frequency in patients who needed more days of oxygen supplement. Initial chest x-ray with lobar consolidation was observed in patients with greater risk of Intensive care unit admission. Conclusion. The most frequent radiological patterns found were ground-glass opacities and peribronchial markings. Lobar consolidation and ground-glass opacities are associated with adverse outcome.

Introducción. En 2009, la OMS declaró a la infección por el virus Influenza A H1N1 como pandemia mundial. Se ha comunicado que el patrón radiológico podría predecir la evolución clínica en pacientes afectados. Objetivo. Describir los hallazgos radiológicos en las radiografías de tórax (Rx) de frente, obtenidas al ingreso institucional, en pacientes pediátricos internados con infección respiratoria por Infuenza A H1N1 y su correlación con la evolución clínica. Población y métodos. Estudio retrospectivo, observacional y descriptivo de la historia clínica y la Rx de frente al ingreso en 47 pacientes con diagnóstico de infección respiratoria por Influenza A H1N1. Resultados. La Rx fue patológica en el 94% de los pacientes. El patrón de condensación fue más frecuente en pacientes que requirieron mayor cantidad de días de oxígeno y mayor riesgo de internación en unidad de cuidados intensivos. El patrón en vidrio esmerilado se asoció también con mayor cantidad de días de oxígeno suplementario. Conclusiones. Las Rx presentaron patrones predominantes en vidrio esmerilado y refuerzo peribronquial. Los niños con hallazgos radiológicos de condensación lobular y vidrio esmerilado al ingreso presentaron una evolución clínica más grave.

Neste trabalho investigou-se a atividade fotodinâmica de octaetilporfirina (OEP), octaetilporfirina de vanadil (VOOEP) e meso-tetramesitilporfirina (m-TMP). Este estudo foi realizado através da determinação da constante da velocidade de fotoxidação (k f) do aminoácido triptofano (Trp). A participação do oxigênio singlete nesta fotoxidação foi determinada através da adição de azida de sódio e água deuterada no meio de reação. Os valores de k f/10-4s-1 para a fotoxidação de Trp demonstraram que OEP (2,80 ± 0.05) é mais eficiente do que m-TMP (1,62 ± 0,07) e VOOEP (0,81 ± 0,08). Os valores de k f foram menores na presença de azida de sódio e maiores na presença de água deuterada, sugerindo que o oxigênio singlete é o responsável pela atividade fotodinâmica de OEP, VOOEP e m-TMP. Estes resultados sugerem também que as diferenças na atividade fotodinâmica entre as porfirinas podem ser associadas com as diferenças na estrutura molecular das mesmas. A presença do grupo vanadil (V=O) interfere claramente na atividade fotodinâmica de OEP causando considerável redução na sua eficiência.

In this work an investigation of the photodynamic efficiency of octaethylporphyrin (OEP), vanadyl octaethylporphyrin (VOOEP), and meso-tetramesitylporphyrin (m-TMP) was done. This study was performed by the determination of photoxidation rate constants (k f) of the tryptophan amino acid (Trp). The mechanism involved in the photoxidation of Trp was also studied using sodium azide (singlet oxygen scavenger) and deuterium oxide. The values of k f/10-4s-1 for Trp photoxidation demonstrated that OEP (2.80 ± 0.05) is more efficient than m-TMP (1.62 ± 0.07) and VOOEP (0.81 ± 0.08). The values of k f were reduced by the presence of sodium azide and increased by deuterium oxide indicating that singlet oxygen is responsible by OEP, VOOEP, and m-TMP photoactivity. These results indicated that differences in the photodynamic activity between porphyrins could be associated with differences in their molecular structures. The presence of vanadyl group (V=O) interferes clearly in the photodynamic activity of OEP causing a considerable reduction in its efficiency.

We conducted a retrospective analysis of the influence of full doses of calcineurin inhibitors [8-10 mg kg-1 day-1 cyclosporine (N = 80), or 0.2-0.3 mg kg-1 day-1 tacrolimus (N = 68)] administered from day 1 after transplantation on the transplant outcomes of a high-risk population. Induction therapy was used in 13% of the patients. Patients also received azathioprine (2 mg kg-1 day-1, N = 58) or mycophenolate mofetil (2 g/day, N = 90), and prednisone (0.5 mg kg-1 day-1, N = 148). Mean time on dialysis was 79 ± 41 months, 12% of the cases were re-transplants, and 21% had panel reactive antibodies >10%. In 43% of donors the cause of death was cerebrovascular disease and 27% showed creatinine above 1.5 mg/dL. The incidence of slow graft function (SGF) and delayed graft function (DGF) was 15 and 60%, respectively. Mean time to last dialysis and to nadir creatinine were 18 ± 15 and 34 ± 20 days, respectively. Mean creatinine at 1 year after transplantation was 1.48 ± 0.50 mg/dL (DGF 1.68 ± 0.65 vs SGF 1.67 ± 0.66 vs immediate graft function (IGF) 1.41 ± 0.40 mg/dL, P = 0.089). The incidence of biopsy-confirmed acute rejection was 22% (DGF 31%, SGF 10%, IGF 8%). One-year patient and graft survival was 92.6 and 78.4%, respectively. The incidence of cytomegalovirus disease, post-transplant diabetes mellitus and malignancies was 28, 8.1, and 0%, respectively. Compared to previous studies, the use of initial full doses of calcineurin inhibitors without antibody induction in patients with SGF or DGF had no negative impact on patient and graft survival.

A terapia fotodinâmica (TFD) está baseada na administração e no acúmulo de fotossensibilizador, por exemplo, de tipo porfirina ou clorina, em tecidos doentes. As clorinas apresentam propriedades fotofísicas semelhantes àquelas das porfirinas, mas com intensificação e deslocamento das bandas Q, o que faz com que sejam bons candidatos para TFD. Neste trabalho relata-se a síntese da 5,10,15-tris(pentafluorofenil)-20-(4-piridil)porfirina, (2), e das clorinas isômeras 4, (5,10,20-tris(pentafluorofenil)-15-(4-piridil)-tetra-hidro-1H- N-metil-pirrolo[3,4-b]porfirina e 5, (5,10,15-tris(pentafluorofenil)-20-(4-piridil)-tetra-hidro-1H- N-metil-pirrolo[3,4-b]porfirina, obtidas a partir de 2, por reação de cicloadição 1,3-dipolar com um ileto azometínico, e respectivas caracterizações estruturais por UV-Vis, RMN e EM-FAB. Foram avaliadas as propriedades fotofísicas, fotoquímicas e fotodegradativas para a nova clorina 4, obtida com melhor rendimento que o seu isômero 5. O rendimento quântico de fotodegradação (fiFd, mol Einstein-1) foi de 0,047±0,014. Foram ainda realizados testes com ácido úrico para demonstrar a capacidade do fotossensibilizador na produção de ¹O2. Os resultados mostraram que a nova clorina 4 pode ser considerada como um bom fotossensibilizador para TFD.

Photodynamic therapy (PDT) is based on the accumulation of a photosensitizer, such as a porphyrin or a chlorin, in a malignant tissue after its administration. Chlorins exhibit photophysical properties similar to those of the porphyrin macrocycles, but with intensified and red-shifted Q bands, making chlorin-containing systems even better candidates for PDT. In this contribution, we report the synthesis of 5,10,15-tris(pentafluorophenyl)-20-(4-pyridyl)porphyrin, (2) and its transformation to the novel chlorin derivatives 4, (5,10,20-tris(pentafluorophenyl)-15-(4-pyridyl)-tetrahydro-1H- N-methyl-pyrrolo [3,4-b]porphyrin and 5, (5,10,15-tris(pentafluorophenyl)-20-(4-pyridyl)-tetrahydro-1H- N-methyl-pyrrolo[3,4-b]porphyrin) by 1,3-dipolar cycloaddition with an azomethine ylide. The new products have been characterized by UV-Vis, ¹H NMR and FAB-MS. The photophysics, photochemical and photobleaching properties of chlorin 4 have been evaluated. Its quantum yield of photobleaching (phiPb, mol Einstein-1) was 0.047±0.014. In order to demonstrate the production of ¹O2 when 4 is used as a photosensitizer, uric acid tests have been carried out. The results indicate that chlorin 4 can be considered a promising photosensitizer in PDT.

Resíduos gerados por curtumes e pela exploração de carvão mineral são produtos potencialmente poluentes em várias regiões do Brasil, principalmente nos estados do Rio Grande do Sul e de Santa Catarina. O presente trabalho foi realizado no campo com o objetivo de avaliar o efeito da adição de resíduos de curtume e rejeito carbonífero sobre o solo e sobre as plantas cultivadas em um Argissolo Vermelho distrófico típico da Estação Experimental Agronômica da UFRGS, localizada no município de Eldorado do Sul (RS). O experimento foi realizado no ano agrícola de 1996/97, em parcelas de 70 m², cultivando-se soja (Glycine max L. Merrill) e milho (Zea mays L.). Tratamentos com a adição de 21,3 e 42,5 t ha-1 de lodo de curtume (LC) com adubação fosfatada e potássica na forma mineral foram comparados com o tratamento com adubação mineral completa (NPK) mais correção da acidez do solo e com a testemunha absoluta. Foram estudados também: (a) adição de resíduo carbonífero (106 t ha-1) mais adubação mineral; (b) resíduo carbonífero (106 t ha-1) mais lodo de curtume (21,3 t ha-1) com adubação fosfatada e potássica; (c) serragem cromada (29 t ha-1) mais adubação mineral (NPK), e (d) Cr mineral (125 kg ha-1) mais lodo de curtume (21,3 t ha-1) com adubação fosfatada e potássica. Foram avaliadas as alterações químicas e biológicas do solo, bem como os efeitos da aplicação dos resíduos sobre o rendimento e absorção de metais pelas plantas. A adição de LC aumentou o valor de pH e o teor de Ca trocável do solo. Não foram constatadas alterações nas concentrações dos metais Cu, Cd, Pb e Ni no solo, aumentando, entretanto, significativamente os teores de Cr. A atividade microbiana avaliada pela produção de CO2 foi estimulada pela adição dos resíduos, mas a população de bactérias, fungos e ctinomicetos não foi afetada. A adição de LC propiciou rendimentos de soja e milho semelhantes aos com adição de fertilizante nitrogenado. A adição de serragem cromada não alterou o rendimento das culturas, enquanto o rendimento de grãos de milho aumentou com a adição de resíduo carbonífero.

Tannery and coal residues are potential pollution sources in numerous regions of Brazil, mainly in the Rio Grande do Sul and Santa Catarina States. In order to evaluate the effects of tannery residue and coal mining refuse on soil properties and cultivated plants, a field experiment was carried out in 1996/97 at the UFRGS Experimental Station, in the Eldorado do Sul county, State of Rio Grande do Sul, Brazil. Corn (Zea mays L.) and soybean (Glycine max L. Merrill) were cultivated on 70 m² plots of a Paleudult Soil. Tannery sludge additions at rates of 21.3 and 42.5 t ha-1 with mineral phosphate and potassium fertilization were compared to mineral fertilization (NPK) with liming and a control treatment. Moreover, treatments with (a) coal mining residue (106 t ha-1) and mineral fertilization; (b) coal mining residue (106 t ha-1) with tannery sludge (21.3 t ha-1) plus mineral phosphate and potassium fertilization; (c) leather shavings (29 t ha-1) with mineral fertilization (NPK), and (d) and a combination of Cr2(SO4)3 (125 kg ha-1 Cr) and 21.3 t ha-1 tannery sludge with mineral phosphate and potassium fertilization were studied. Chemical and biological soil alterations were evaluated, as well as the effect of residue application on the plant yields and heavy metal uptake. Tannery sludge increased the soil pH, exchangeable Ca, and total Cr contents, while no alterations of the Cu, Cd, Pb, and Ni soil contents were observed. Microbial activity, evaluated by the CO2 production, was stimulated by the residue application, but bacteria, fungi and actinomycete populations were not affected. Tannery sludge applications had a similar influence on soybean and corn grain yields as nitrogen fertilizers. Crop yields were not affected by the addition of leather shavings, while coal mining residue increased the corn grain yield.

O presente trabalho foi elaborado com o objetivo de avaliar o rendimento das culturas do trigo, alface e rabanete e as alterações químicas de um Latossolo resultantes da adição de resíduos de curtume e de crômio hexavalente. Microparcelas, constituídas por recipientes com 60 L de solo e mantidas em casa de vegetação, receberam os seguintes tratamentos: testemunha; calcário + NPK; lodo do decantador primário + PK; resíduo de rebaixadeira de couro + calcário + NPK; aparas de couro + calcário + NPK; Cr6+ + calcário + NPK ; Cr6+ + calcário + esterco bovino; calcário + esterco bovino. O lodo continha 8,5 g kg-1 de Cr e foi aplicado em dose correspondente a 8,8 t ha-1. O resíduo de rebaixadeira possuía 17,1 g kg-1 Cr e as aparas de couro, 19,4 g kg-1 Cr. Esses resíduos foram aplicados nas doses correspondentes a 4,4 e 3,8 t ha-1. As doses de Cr6+ (K2Cr2O7) e esterco bovino foram de 100 mg kg-1 e 20 t ha-1, respectivamente. A aplicação de lodo elevou o pH do solo de 5,1 para 5,8; os teores de N, de 1,26 para 1,51 g kg-1, e os teores de Ca, de 4,1 para 5,9 cmol c dm-3, proporcionando rendimentos das três culturas equivalentes aos obtidos com a aplicação de calcário + NPK. Os teores de crômio no solo e nas partes vegetativas das culturas nos tratamentos com aplicação dos resíduos de curtume variaram, respectivamente, de 40,7 a 71,2 e de 0,08 a 2,71 mg kg-1, sendo considerados normais. A adição de resíduo de rebaixadeira de couro ou das aparas de couro não reduziu os rendimentos das culturas e não alterou os teores de Cr do solo e das plantas. A adição de Cr6+ provocou um efeito tóxico nas plantas, sendo responsável pela diminuição do rendimento da cultura do trigo em 91 % e da cultura da alface em 86 %, quando comparadas ao tratamento Calcário + NPK. Este efeito foi diminuído com a adição de agentes redutores como o esterco bovino.

This study was carried out in order to evaluate yields of wheat, lettuce and radish, as well as chemical changes in an Oxisoil due to the addition of tannery waste and hexavalent chromium. Microplots in a greenhouse, which consisted of 60 L plastic pots, received the following treatments: control; lime + NPK; primary tannery sludge + PK; chrome-tanned leather shavings + lime + NPK; finished leather shreds + lime + NPK; Cr6+ + lime + NPK; Cr6+ + lime + cattle manure; lime + cattle manure. The sludge contained 8.5 g kg-1 Cr and was applied at rates of 8.8 t ha-1. The leather shavings contained 17.1 g kg-1 and the shreds, 19.4 g kg-1 Cr. These wastes were applied at rates of 4.4 and 3.8 t ha-1, respectively. The Cr6+ (K2Cr2O7) and the cattle manure rates were 100 mg kg-1 and 20 t ha-1, respectively. Tannery sludge plus PK increased the soil pH (5.1 to 5.8), the soil N (1.26 to 1.51 g kg-1), and the soil Ca (4.1 to 5.9 cmol c dm-3) .Wheat, lettuce and radish yields in this treatment were similar to the ones obtained with lime plus NPK. Chromium concentrations in the soil and crops cultivated with tannery sludge varied from 40.7 to 71.2 and from 0.08 to 2.71 mg kg-1, respectively. These values were considered normal. Additions of chrome-tanned leather shavings and finished leather shreds did not decrease the crop yields or change Cr concentrations in soil or plants. Cr6+ applications caused an intoxication of the plants which provoked a yield drop in wheat and lettuce of 91 and 86 %, respectively, in comparison to lime plus NPK. The toxic effect of Cr6+ decreased when cattle manure was added.

Realizou-se um experimento em laboratório, com o objetivo de avaliar não só a redução do cromo hexavalente aplicado ao solo com ênfase ao efeito da aplicação de carbono orgânico, manganês divalente, mas também a participação da microbiota do solo. Utilizaram-se, como unidades experimentais, amostras de 50 g de um Argissolo, acondicionadas em sacos de polipropileno e incubadas durante 42 dias com calcário para elevar o pH a 6,0 (2,0 t ha-1 de CaCO3 + MgCO3 na proporção de 2:1), Cr6+, esterco bovino e Mn2+ nas doses de 20, 50 e 40 mg kg-1, respectivamente. Metade das amostras foi sujeita à esterilização por autoclavagem com o objetivo de eliminar a atividade biológica. A aplicação de esterco bovino e sulfato de manganês promoveu a total redução do cromo hexavalente para cromo trivalente (Cr6+ → Cr3+) no solo, em 42 dias. Os modelos, quadrático e exponencial, foram os que melhor descreveram a cinética de redução com o tempo. A redução do Cr6+ foi estimulada pela atividade microbiana, sendo 16% maior em amostras de solo não esterilizadas, que continham esterco bovino, em comparação com as mesmas amostras esterilizadas por autoclavagem. Os resultados demonstraram que a descontaminação do solo que contém teores tóxicos de Cr6+ pode ser viabilizada tanto pela incorporação de adubo orgânico como pela manutenção de sua atividade biológica.

A laboratory experiment was carried out to evaluate the hexavalent chromium reduction as affected by organic carbon amendment, Mn2+ and microbial activity. Samples of a Hapludult soil (50 g) were placed in plastic bags (50 g) and incubated during 42 days with lime (2.0 Mg ha-1), Cr6+, cattle manure(organic carbon) and Mn2+ in the doses of 20, 50 and 40 mg kg-1, respectively. Half the samples were sterilized by autoclaving to eliminate biological activity. Cattle manure and Mn sulfate amendment promoted a total soil hexavalent chromium reduction (Cr6+ → Cr3+), during the 42-day period. The quadratic and exponential models were the best to describe the Cr6+ reduction with time. The microbial activity increased this reduction in 16%, in the cattle manure treatment without sterilization. The soil Cr6+ contamination may be eliminated by simple organic matter amendment and by maintaining biologic activity.

O consórcio de eucalipto e acácia negra pode trazer benefícios ecológicos e econômicos, tendo em vista a diversidade ambiental e redução dos custos com adubação nitrogenada. Este trabalho teve o objetivo de quantificar os nutrientes no solo e nas plantas e avaliar o crescimento e a produção de eucalipto em consórcio com acácia negra. Foram estudados sistemas de cultivo simples e consorciado de Eucalyptus saligna (Smith) e Acacia mearnsii (De Wild.), com 45 meses de idade, em Argissolo Vermelho-Amarelo, no estado do Rio Grande do Sul. O espaçamento foi de 4,0 x 1,5 m e, no consórcio, as espécies foram plantadas em fileiras alternadas. Quantificaram-se N total, P, K, Ca, Mg, Al e matéria orgânica no solo e N total, P, K, Ca e Mg nas plantas. Avaliaram-se altura e diâmetro das árvores, bem como o volume de madeira produzido. As amostras de solo foram coletadas nas profundidades de 0-5, 5-10, 10-20 e 20-40 cm. Os resultados demonstraram maior teor de matéria orgânica e nitrogênio total no solo do consórcio em relação ao eucalipto simples. Solo sob cultivo simples de acácia mostrou maior teor de K, Ca e Mg que nos povoamentos em que o eucalipto estava presente. Plantas de eucalipto consorciado absorveram mais nitrogênio (22%) do que as do cultivo simples. O volume total de madeira no consórcio não diferiu do cultivo simples de eucalipto, embora o eucalipto tenha contribuído com 64% da produção do consórcio. O consórcio beneficiou a nutrição de nitrogênio do eucalipto e aumentou o estoque de nitrogênio no ecossistema, enquanto manteve a produção total de madeira.

Mixed plantations of eucalypt and acacia can be beneficial from both the ecological and economic viewpoints, as they increase the biological diversity and reduce the costs of nitrogen fertilization. This trial had the objective to evaluate the effect of mixed plantations of Eucalyptus saligna (Smith) and Acacia mearnsii (De Wild) on soil and stand characteristics. The experiment was carried out on a Red Yellow Latosol, in the state of Rio Grande do Sul, Brazil, and the treatment consisted of pure and mixed stands of the two species. The spacing was of 4 by 1,5 m, and in the mixed stand the species were planted in alternate rows. The evaluations were performed when the stands were 45 months old. The trees were measured for diameter and height for volume estimation, the biomass of the aboveground components was determined and tissue samples taken for chemical analyses. Soil samples were collected from 0-5; 5-10; 10-20, and 20-40 cm depth. Total stem volume did not differ between mixed and eucalypt pure plantations. In the mixed plantation, 64% of the total volume was provided by the eucalypt trees. The eucalypt trees in the mixed stands accumulated more (22%) nitrogen than in the pure stands. Soil organic matter, total nitrogen was higher in the mixed than in the eucalypt pure stand. Soil under the pure stands of Acacia had higher base content than those where eucalypt was present due to eucalypt higher biomass production and nutrient accumulation. Mixed plantation improves eucalypt nitrogen nutrition and increases the nitrogen pools of the ecosystem while maintaining total wood production.

Com o objetivo de avaliar a disponibilidade de nitrogênio do solo para a aveia e o milho, realizou-se um experimento em microparcelas com vinte solos do Rio Grande do Sul. As microparcelas foram constituídas por recipientes com 20 L de solo, com drenagem livre, mantidas em céu aberto e com irrigação quando necessária. Foi determinado o N absorvido por plantas de aveia preta (Avena strigosa ) e por três cultivos sucessivos de milho (Zea mays ). Foram determinados, inicialmente, os teores de N-total e de matéria orgânica dos solos. Antes de cada cultivo, foram também determinados os teores extraíveis de N por KMnO4 0,05 mol L-1, tampão fosfato-borato e por KCl 2 mol L-1 às temperaturas de 100 e 95°C, durante 4 e 16 horas, respectivamente. O N do solo extraído por KCl 2 mol L-1 a 95°C por 16 h apresentou os maiores coeficientes de correlação com o somatório do N acumulado pelas plantas nos quatro cultivos. Os coeficientes de correlação entre o N extraído por todos os métodos químicos e o N acumulado pelas plantas aumentaram com a correção da acidez do solo a pH 6,0.

In order to evaluate organic N availability to oats and corn, a microplot experiment was carried out using 20 types of soil from Rio Grande do Sul State, Brazil. Microplots consisted of 20 L soil plastic pots with free drainage, maintained in an open area, with supplemental irrigation when necessary. N taken up by oats (Avena strigosa) and three corn (Zea mays) crops grown in successions was evaluated. Soil total-N and organic matter contents were initially determined as well as N extracted by acid 0.05 mol L-1 KMnO4, phosphate-borate buffer and by 2 mol L-1 KCl at 100°C and 95°C temperature for 4 and 16 hours, respectively, on samples taken before each crop. N extracted by 2 mol L-1 KCl at 95°C for 16 hours showed the highest correlation coefficient with total-N taken up by plants from all crops. Liming soil to pH 6.0 increased the correlation coefficients for all the tested methods.

São feitas considerações a respeito das novas técnicas de revascularização cerebral. Os resultados obtidos em uma série de 5 doentes, submetidos a 6 anastomoses entre artéria temporal superficial e ramo da cerebral média, foram satisfatórios. Esta técnica relativamente inócua é, quando bem indicada, bastante útil.

Techniques of microsurgical revascularization are reviewed. A series of 5 cases, submited to 6 anastomosis of the superficial temporal artery is presented.

O tratamento cirúrgico da siringomielia é, em geral, considerado decepcionante. Vários tipos de drenagem da cavidade siringomiélica não têm fornecido resultados satisfatórios. Gardner, em magnífica série de trabalhos, mostrou que a siringomielia e as várias malformações associadas à hidrocefalia têm fisiopatogenia única. Baseado em sua teoria, Gardner propôs, em 1958, o bloqueio da comunicação entre o IV ventrículo e o canal central da medula, para o tratamento da siringomielia. Esta técnica não tem sido realizada com muita freqüência. Empregamos o método proposto por Gardner em 4 pacientes, os quais melhoraram após a intervenção cirúrgica.

The surgical treatment of syringomyelic patients is usually considered as deceptional. The drainage methods employed have resulted insatisfactory. Gardner, in a classical series of papers, developed the "hydromyelic theory" to explain syringomyelia and others nervous system malformatins. Founded on his own theory he proposed the blockadge of the communication between the fourth ventricle and the central canal. We have employed this method on 4 patients, with satisfactory results.