Efeito de doses de nitrapirina (2-cloro-6-triclorometil piridina), na nitrificação do sulfato de amônio e da uréia, em dois solos (LE e Pml) do Estado de São Paulo

Foram adicionados aos solos LE e Pml 36 ppm de N, na forma de sulfato de amonio e uréia, com 0; 1,2; 2,4 e 4,8 ppm de nitrapirina. Os solos foram incubados por 150 dias à temperatura entre 25ºC e 30ºC, com 75% do seu poder de embebição. Aos 50, 100 e 150 dias de incubação, procedeu-se a determinação dos teores de NO-3 e calculou-se a porcentagem de inibição da nitrificação nos tratamentos com nitrapirina Verificou-se que o teor de NO-3 no solo diminui significativamente, quando o sulfato de amonio e a uréia são associados com nitrapirina. A nitrapirina inibe igualmente a nitrificação do sulfato de amonio e da uréia, e apresenta inicialmente porcentagem de inibição da nitrificação (1%) no LE que no Pml. O tempo de ação da nitrapirina no solo ultrapassa 150 dias.

Síntese e atividade fitotóxica de 2-fenil-6,7-exo-isopropilidenodioxi-8-oxabiciclo [3.2.1]oct-2-eno

The [3+4] cycloaddition between furan and the oxyallyl cation generated from 1-bromo-1-phenylpropan-2-one (4), resulted in the formation of 2-phenyl-8-oxabicyclo[3.2.1]oct-6-en-3-one (5) in 30% yield. This compound was further converted into 2-phenyl-6,7-exo-isopropylidenedioxi-8-oxabicyclo[3.2.1]oct-2-ene (13) in 35.4% yield. The selective effect of compound (13) and its isomer 3-phenyl-6,7-exo-isopropylidenedioxi-8-oxabicyclo[3.2.1]oct -2-ene (1a) on the radicle growth of Sorghum bicolor L. (sorghum) and Cucumis sativus L. (cucumber) were evaluated. For both plants, compound 13 showed to be more potent than its isomer 1a.

Síntese de novas fitotoxinas derivadas do 8-oxabiciclo[3.2.1]oct-6-en-3-ona

The [4+3] cycloaddition was utilized in order to prepare 8-oxabicyclo[3.2.1]oct-6-en-3-one (1) derivatives. The correspondent acetonide 6 was converted into several alcohols (11-16). Addition of aryllithium reagents to 6 resulted in 3-(2-fluorophenyl)-6,7-exo-isopropylidenedioxy -8-oxabicyclo[3.2.1]octan-3alpha-ol (11, 72%) and 3-(2,4-dimethoxyphenyl)-6,7-exo-isopropylidenedioxy-8-oxabicyclo[3.2.1]octan -3alpha-ol (16, 20%). The 3-butyl-6,7-exo-isopropylidenedioxy-8-oxabicyclo[3.2.1]octan-3 alpha-ol (15, 56%) was obtained through a Grignard reaction. Reduction of 6 resulted in 6,7-exo-isopropylidenedioxy-8-oxabicyclo[3.2.1]octan-3 beta-ol (7, 62%) and 6,7-exo-isopropylidenedioxy-8-oxabicyclo[3.2.1]octan-3 alpha-ol (8, 20%). The alcohols were treated with thionyl chloride in pyridine, and the corresponding alkenes were obtained with 31-80% yield. The effect of these compounds on the development of radicle and aerial parts of Sorghum bicolor was evaluated.

Caracterização de 2,2',4,4',6,6'-hexanitroestilbeno via análises instrumentais

2,2',4,4',6,6'-hexanitrostilbene (HNS) is a very important high explosive that is used in a range of military, aerospace and industrial formulations owing to its suitable properties. It is an insensitive and thermaly stable explosive that can be produced from 2,4,6-trinitrotoluene (TNT). This paper shows the characterization of synthesized HNS by different techniques, such as elementary analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR) and through the determination of the heat of combustion in a calorimeter.

PRENYLATED XANTHONES FROM Rheedia acuminata (reprinted from Acta Amazônica, 23(2/3):181-185)

Pyranojacareubin; 1,5-dihydroxy-6',6'-dimethyl-2H-pyran(2,,3':6,7) -6",6"-dime-thyl-2H,4H-pyran(2",3":2,3)xanthone and a new xanthone l,6-dihydroxy-5-methoxy-6',6'-dime-thyl-2H-pyran(2',3':3,2)-7-(3,3-dimethylprop-2-enyl)xanthone were isolated from the ether extract of the root bark of Rheedia acuminata together with friedelin and friedelanol.

Efeitos do ácido 2-cloroetilfosfônico na maturação de folhas em cultura de fumo (Nicotiana tabacun L.)

Estudou-se a influência do ácido 2-cloroetilfosfônico, aplicado em cultura de fumo (Niaotiana tabacum L.) cultivar "Goianinho", em condições de campo, visando uniformizar e antecipar a colheita das folhas. Aplicou-se o produto comercial Ethrel (240 g/l de i.a), nas dosagens de 2,4, 6 e 8 litros/ha, quando nas folhas apre sentavam, na maior parte da planta o crescimento máximo. Após 6 dias do tratamento, foram as folhas colhidas, contadas e pesadas. Os resultados obtidos mostraram que o regulador vegetal utilizado promoveu um amadurecimento mais precoce, antecipando e uniformizando a colheita das folhas de fumo, independentemente das concentrações utilizadas, que não diferiram entre si.

A doença de Chagas no Paraná

In recent speech in Curitiba (May 22nd, 1954), Dr. Mario Pinotti, Director, Serviço Nacional da Malaria, informed that his personnel started on February, 1953, a survey upon chagas Disease in 23 counties of the State of Paraná, South Brazil. out of 895 places surveyed, 678, or 75.7%, were infected by Triatoma infestans klug 1834 and in 234 out of those 678, or 34.5%, this vector was infected by Trypanosoma cruzi. The general natural infection of the insects examined reached 18.86%. The serological survey (Machado-Guerreiro test) was positive in 10.7% of the persons examined in jacarezinho and in 28.3% of those living in Bôa Vista. These data suggested the author to actualise the subject. During his control of severe outbreack of malaria in the North part of Paraná, from march to June 1917 he worked in 8 counties. March 1917 he photographed in Boa Vista four girls, severe cases of chronic malaria, two of which showed bi-palpebral oedema, later on considered by Dr. Pinho Simões (1943) as Romanã syndrome (created in 1935) and Prof. Salvador Mazza (1946) classified as typical cases of Chagas' Disease. now, being elapsed 36 years, the National Service of Malaria confirmed the discovery. The region surveyed was populated, in the beginning of this century, by immigrants from the State of Minas Gerais, from where the author believes that were imported the disease and its vectors. In April 1917 the A. discovered that the old town Jatahy was a big focus of Triatoma megista (now Panstrongylus megistus0. All its 43 houses were strongly infested by such hematophagus and amongst the 200 inhabitants seen many were suspicious cases of chronic cases of Chagas's Disease. In the Indians town (three tribes) of S. Pedro D' Alcantara, situated in front of Jatahy, in the left side of the river Tibagy, there were no Triatomas nor suspicious cases of trypanosomiasis. In 1919 the author started the control of the endemics by destroying the foci of Triatomas and reforming the housing. In 1946 he returned to jatahy and found the sanitary conditions of the town and its inhabitants much better. Climate of the region is favorable to spreading of all tropical diseases, being very suitable one for an extensive sanitary survey. In 1943 Dr. Pinho Simões examined 85 triatomas ( T. infestans) from six counties of the North region and found 40, or 46% infected by Trypanosoma cruzi. The highest incidences were; Joaquim Tavora 74.2% and Carlópolis 26.9%. These counties seem to be infested by Itaporanga county of São Paulo State. in 1953 Serviço nacional da Malária proved that 19 out of 23 counties surveyed were infested by Triatoma infestans. They examined 7,701 of this insect and found 1,453 positive for Trypanosoma cruzi, or 18.9%. in two counties, Jacarezinho and Sengés, were examined 2,588 human bloods, not selected, and 323, or 12.6% of such samples were positive for Chagas' Disease. This year the Malaria Service is doing insects survey in 25 other counties and DDTising infested domiciles of another eight. Such activity is very promising and should be extended to other places.

Velocidade da água e a distribuição de larvas e pupas de Chirostilbia pertinax (Kollar) (Diptera, Simuliidae) e macroinvertebrados associados

O presente trabalho objetivou investigar a relação entre a velocidade da água e a distribuição dos estágios imaturos de Chirostilbia pertinax (Kollar, 1832) e os macroinvertebrados bentônicos associados. As coletas foram realizadas em cinco pontos, no trecho superior do Rio dos Sinos, no Estado do Rio Grande do Sul. A fauna bentônica foi amostrada com substratos artificiais, que permaneceram instalados nos locais de maior corenteza d'água por períodos de 14 dias. Antes do recolhimento dos substratos foram realizadas medidas de velocidade d'água no local da sua instalação. Essas medidas foram agrupadas em três classes: baixa (0,20 a 0,63 m/s), média (0,64 a 1,07 m/s) e alta (1,08 a 1,50 m/s) para posterior relação com a distribuição da fauna coletada. Para avaliar a influência da velocidade de água sobre a distribuição dos macroinvertebrados e a abundância de C. pertinax foi realizada uma regressão múltipla. As coletas resultaram em 39.598 indivíduos, sendo 33.418 simulídeos e 6.180 macroinvertebrados associados. Entre os simulídeos 5.704 espécimes correspondem a larvas do último ínstar e pupas, dos quais 828 são de C. pertinax. Quanto à distribuição dessa espécie, 30,8% ocorreram na classe de baixa velocidade d'água, 24,9% na velocidade média e 44,3% na alta velocidade. Foi observado que a abundância de C. petinax aumenta à medida que os macroinvertebrados predadores diminuem e os organismos não predadores aumentam (GLM, R² = 0,207; F 2,50 = 6,536; P = 0,003). Esses resultados revelam que os imaturos de C. pertinax têm uma tendência em ocupar um microhábitat com menor ocorrência de predadores.

Kinetics of chronic inflammation in Nile tilapia fed n‑3 and n‑6 essential fatty acids

The objective of this work was to investigate the effect of dietary supplementation with essential fatty acids on the kinetics of macrophage accumulation and giant cell formation in Nile tilapia (Oreochromis niloticus). The supplementation sources were soybean oil (SO, source of omega 6, n‑6) and linseed oil (LO, source of omega 3, n‑3), in the following proportions: 100% SO; 75% SO + 25% LO; 50% SO + 50% LO; 25% SO + 75% LO; and 100% LO (four replicates per treatment). After a feeding period of three months, growth performance was evaluated, and glass coverslips were implanted into the subcutaneous connective tissue of fish, being removed for examination at 2, 4, 6, and 8 days after implantation. Growth performance did not differ between treatments. Fish fed 100% linseed oil diet had the greatest macrophage accumulation and the fastest Langhans cell formation on the sixth day. On the eighth day, Langhans cells were predominant on the coverslips implanted in the fish feed 75 and 100% linseed oil. n‑3 fatty acids may contribute to macrophage recruitment and giant cell formation in fish chronic inflammatory response to foreign body.

Determinação das energias de ativação para nucleação de precipitados e difusão da prata na liga cu-2%al com adições de prata

As energias de ativação para nucleação de precipitados ricos em prata e de difusão da prata no cobre, em ligas de Cu-2%Al contendo 2, 4, 6, 8, 10 e 12%Ag, em peso, foram determinadas utilizando-se medidas de variação da microdureza com a temperatura e o tempo de envelhecimento. Os resultados indicaram que, com o método utilizado, é possível obter valores para as energias de ativação para nucleação da fase rica em prata e de difusão da prata no cobre bastante próximos daqueles citados na literatura.

Efeito de subdoses de 2,4-D na produtividade de uva itália e suscetibilidade da cultura em função de seu estádio de desenvolvimento

Durante os anos agrícolas de 2002-2003 e 2003-2004 foram conduzidos trabalhos no município de Maringá - PR, com o objetivo de avaliar o dano potencial de subdoses de 2,4-D sobre plantas de uva, imitando depósitos decorrentes de deriva. No primeiro experimento, a aplicação foi realizada cerca de 30 dias após a poda de inverno, num pomar de uva Itália. As doses utilizadas foram de 6,72; 13,44; 26,88; 53,76 e 107,52 g de equivalente ácido (e.a.) por hectare de 2,4-D, equivalentes a depósitos de 1,0%; 2,0%; 4,0%; 8,0% e 16,0%, assumindo-se uma aplicação de 1 L ha-1 (670 g e.a. ha-1). Nessa data, as plantas encontravam-se na fase de emissão de cachos e florescimento (estádio 15). O surgimento de sintomas visuais de fitointoxicação foi imediato e proporcional às doses aplicadas. A produtividade da cultura foi afetada por todas as doses aplicadas nesse estádio de crescimento. No entanto, mesmo com as injúrias severas registradas na dose mais alta, as plantas afetadas se recuperaram após duas podas para as condições de manejo regionais (duas safras por ano). No segundo experimento, foram aplicadas doses equivalentes a derivas de 1,0 e 2,0% (6,72 e 13,44 g e.a. ha-1) em três estádios do ciclo de desenvolvimento. A aplicação de doses < 13,44 g e.a. ha-1 (2,0% de deriva simulada) a partir do estádio de "meia-baga", não causou repercussões negativas em termos de injúrias visuais e produtividade.

An improved HPLC method for the quantitation of 6-mercaptopurine and its metabolites in red blood cells

A procedure is described for the rapid determination of the intra-erythrocyte concentration of 6-mercaptopurine (6-MP) and its metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP). Erythrocytes (8 x 10(8) cells) in 350 µl Hanks solution containing 7.5 mg dithiothreitol were treated with 50 µl 70% perchloric acid. The precipitate was removed by centrifugation (13,000 g) and the supernatant hydrolyzed at 100°C for 45 min. After cooling, 100 µl was analyzed directly by HPLC using a Radialpack Resolve C18 column eluted with methanol-water (7.5:92.5, v/v) containing 100 mM triethylamine. 6-TG, 6-MP and the hydrolysis product of 6-MMP, 4-amino-5-(methylthio)carbonyl imidazole, were monitored at 342, 322 and 303 nm using a Shimadzu SPD-M10A diode array UV detector. The analytes eluted at 5.3, 6.0 and 10.2 min, respectively. The calibration curves were linear (r² > 0.998), and the analytical recoveries were 73.2% for 6-TG, 119.1% for 6-MP and 97.4% for 6-MMP. The intra- and inter-assay variations were highest for 6-MP (9.6 and 14.3%, respectively). The lowest detectable concentrations were 3, 3 and 25 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The quantification limits (coefficients of variation <15%) were 8, 10 and 70 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The method was applied to the analysis of 183 samples from 36 children under chemotherapy for acute lymphoblastic leukemia. The concentrations of the metabolites in the red cells of the patients ranged from 0 to 1934 pmol/8 x 10(8) erythrocytes for 6-TGN, and from 0 to 105.8 and 0 to 45.9 nmol/8 x 10(8) erythrocytes for 6-MP and 6-MMP, respectively. The procedure gave results that were in agreement with those obtained with other methods designed to detect cases of non-compliance with treatment, including patient interviews and medical evaluation, among others, demonstrating its applicability to monitoring the treatment of leukemic children.

Can organic and transgenic soy be used as a substitute for animal protein by rats?

We evaluated the protein quality of organic and transgenic soy fed to rats throughout life. Thirty female Wistar rats were divided into three groups (N = 10): organic soy group (OSG) receiving organic soy-based diet, genetically modified soy group (GMSG) receiving transgenic soy-based diet, and a control group (CG) receiving casein-based diet. All animals received water and isocaloric diet (10% protein), ad libitum for 291 days. After this, the weight of GMSG animals (290.9 ± 9.1 g) was significantly lower (P <= 0.04) than CG (323.2 ± 7.9 g). The weight of OSG (302.2 ± 8.7 g) was between that of the GMSG and the CG. Protein intake was similar for OSG (308.4 ± 6.8 g) and GMSG (301.5 ± 2.5 g), and significantly lower (P <= 0.0005) than the CG (358.4 ± 8.1 g). Growth rate was similar for all groups: OSG (0.80 ± 0.02 g), GMSG (0.81 ± 0.03 g) and CG (0.75 ± 0.02 g). In addition to providing a good protein intake and inducing less weight gain, both types of soy were utilized in a manner similar to that of casein, suggesting that the protein quality of soy is similar to that of the standard protein casein. The groups fed soy-based diet gained less weight, which may be considered to be beneficial for health. We conclude that organic and transgenic soy can be fed throughout life to rats in place of animal protein, because contain high quality protein and do not cause a marked increase in body weight.

Acetylcholine and bradykinin enhance hypotension and affect the function of remodeled conduit arteries in SHR and SHR treated with nitric oxide donors

Discrepancy was found between enhanced hypotension and attenuated relaxation of conduit arteries in response to acetylcholine (ACh) and bradykinin (BK) in nitric oxide (NO)-deficient hypertension. The question is whether a similar phenomenon occurs in spontaneously hypertensive rats (SHR) with a different pathogenesis. Wistar rats, SHR, and SHR treated with NO donors [molsidomine (50 mg/kg) or pentaerythritol tetranitrate (100 mg/kg), twice a day, by gavage] were studied. After 6 weeks of treatment systolic blood pressure (BP) was increased significantly in experimental groups. Under anesthesia, the carotid artery was cannulated for BP recording and the jugular vein for drug administration. The iliac artery was used for in vitro studies and determination of geometry. Compared to control, SHR showed a significantly enhanced (P < 0.01) hypotensive response to ACh (1 and 10 µg, 87.9 ± 6.9 and 108.1 ± 5.1 vs 35.9 ± 4.7 and 64.0 ± 3.3 mmHg), and BK (100 µg, 106.7 ± 8.3 vs 53.3 ± 5.2 mmHg). SHR receiving NO donors yielded similar results. In contrast, maximum relaxation of the iliac artery in response to ACh was attenuated in SHR (12.1 ± 3.6 vs 74.2 ± 8.6% in controls, P < 0.01). Iliac artery inner diameter also increased (680 ± 46 vs 828 ± 28 µm in controls, P < 0.01). Wall thickness, wall cross-section area, wall thickness/inner diameter ratio increased significantly (P < 0.01). No differences were found in this respect among SHR and SHR treated with NO donors. These findings demonstrated enhanced hypotension and attenuated relaxation of the conduit artery in response to NO activators in SHR and in SHR treated with NO donors, a response similar to that found in NO-deficient hypertension.

Nutritional status and body composition after 6 months of patients switching from continuous ambulatorial peritoneal dialysis to automated peritoneal dialysis

Our objective was to determine if automated peritoneal dialysis (APD) leads to changes in nutritional parameters of patients treated by continuous ambulatory peritoneal dialysis (CAPD). Twenty-six patients (15 males; 50.5 ± 14.3 years) were evaluated during CAPD while training for APD and after 3 and 6 months of APD. Body fat was assessed by the sum of skinfold thickness and the other body compartments were assessed by bioelectrical impedance. During the 6-month follow-up, 12 patients gained more than 1 kg (GW group), 8 patients lost more than 1 kg (LW group), and 6 patients maintained body weight (MW group). Except for length on dialysis that was longer for the LW group compared with the GW group, no other differences were found between the groups at baseline. After 6 months on APD, the LW group had a reduction in body fat (24.5 ± 7.7 vs 22.1 ± 7.3 kg; P = 0.01), body cell mass (22.6 ± 6.2 vs 21.6 ± 5.8 kg, P = 0.02) and phase angle (5.4 ± 0.9 vs 5.1 ± 0.8 degrees, P = 0.004). In the GW group, body fat (25 ± 7.6 vs 27.2 ± 7.6 kg, P = 0.001) and body cell mass (20.1 ± 3.9 vs 20.8 ± 4.0 kg, P = 0.05) were increased. In the present study, different patterns of change in body composition were found. The length of previous dialysis treatment seems to be the most important factor in determining these nutritional modifications.