Knowledge and practice of Brazilian pediatricians on gastroesophageal reflux disease in infants / Conhecimento e prática de pediatras brasileiros sobre a doença do refluxo gastroesofágico em lactentes

OBJECTIVE: To assess the knowledge and practice of pediatricians about infants with physiological reflux and gastroesophageal reflux disease. METHODS: 140 pediatricians were interviewed during two scientific events in 2009 and 2010. The questions referred to two clinical cases of infants. One with symptoms of infant regurgitation (physiological reflux) and another with gastroesophageal reflux disease. RESULTS: Among 140 pediatricians, 11.4% (n=16) and 62.1% (n=87) would require investigation tests, respectively for infant regurgitation (physiological reflux) and gastroesophageal reflux disease. A series of upper gastrointestinal exams would be the first requested with a higher frequency. Medication would be prescribed by 18.6% (n=6) in the case of physiological reflux and 87.1% (n=122) in the case of gastroesophageal reflux disease. Prokinetic drugs would be prescribed more frequently than gastric acid secretion inhibitors. Sleeping position would be recommended by 94.2% (n=132) and 92.9% (n=130) of the respondents, respectively for the case of physiological reflux and gastroesophageal reflux disease; however, about half of the respondents would recommend the prone position. Only 10 (7.1%) of the pediatricians would exclude the cow's milk protein from the infants' diet. CONCLUSIONS: Approaches different from the international guidelines are often considered appropriate, especially when recommending a different position other than the supine and prescription of medication. In turn, the interviews enable us to infer the right capacity of the pediatricians to distinguish physiologic reflux and gastroesophageal reflux disease correctly. .

OBJETIVO: Avaliar o conhecimento e a prática de pediatras brasileiros na assistência ao lactente com refluxo fisiológico e doença do refluxo gastroesofágico. MÉTODOS: Foram entrevistados 140 médicos pediatras em dois eventos científicos em 2009 e 2010. As perguntas referiam-se a dois casos clínicos de lactentes, um com quadro compatível com regurgitação do lactente (refluxo fisiológico) e outro com doença do refluxo gastroesofágico. RESULTADOS: Dos 140 participantes, 11,4% (n=16) e 62,1% (n=87) solicitariam exame para lactentes, respectivamente, com refluxo fisiológico e doença do refluxo gastroesofágico. O primeiro exame solicitado com maior frequência seria a radiografia contrastada de esôfago, estômago e duodeno. Medicação seria prescrita por 18,6% (n=26) para o caso de refluxo fisiológico e 87,1% (n=122) para o caso de doença do refluxo gastroesofágico. Procinéticos seriam prescritos com maior frequência do que os redutores da secreção ácida gástrica. Prescrição de posição para dormir fez parte das recomendações de 94,2% (n=132) e 92,9% (n=130) dos entrevistados, respectivamente, para os casos de refluxo fisiológico e doença do refluxo gastroesofágico. Entretanto, cerca da metade dos entrevistados não recomendaria o decúbito dorsal. Prescrição de dieta de exclusão do leite de vaca para um lactente com quadro de doença do refluxo gastroesofágico seria feita por apenas 10 (7,1%) dos participantes. CONCLUSÕES: Condutas diferentes das diretrizes internacionais são frequentemente consideradas adequadas, especialmente quanto à recomendação de posição diferente do decúbito dorsal e prescrição de medicamentos. As respostas permitem inferir a capacidade de correta diferenciação entre refluxo fisiológico e doença do refluxo gastroesofágico. .

Children's eating behavior: comparison between normal and overweight children from a school in Pelotas, Rio Grande do Sul, Brazil / Comportamento alimentar infantil: comparação entre crianças sem e com excesso de peso em uma escola do município de Pelotas, RS

OBJECTIVE: To evaluate differences in children's eating behavior in relation to their nutritional status, gender and age. METHODS: Male and female children aged six to ten years were included. They were recruited from a private school in the city of Pelotas, Rio Grande do Sul, southern Brazil, in 2012. Children´s Eating Behaviour Questionnaire (CEBQ) subscales were used to assess eating behaviors: Food Responsiveness (FR), Enjoyment of Food (EF), Desire to Drink (DD), Emotional Overeating (EOE), Emotional Undereating (EUE), Satiety Responsiveness (SR), Food Fussiness (FF) and Slowness in Eating (SE). Age-adjusted body mass index (BMI) z-scores were calculated according to the WHO recommendations to assess nutritional status. RESULTS: The study sample comprised 335 children aged 87.9±10.4 months and 49.3% had normal weight (n=163), 26% were overweight (n=86), 15% were obese (n=50) and 9.7% were severely obese (n=32). Children with excess weight showed higher scores at the CEBQ subscales associated with "food approach" (FR, EF, DD, EOE, p<0.001) and lower scores on two "food avoidance" subscales (SR and SE, p<0.001 and p=0.003, respectively) compared to normal weight children. Differences in the eating behavior related to gender and age were not found. CONCLUSIONS: "Food approach" subscales were positively associated to excess weight in children, but no associations with gender and age were found. .

OBJETIVO: Avaliar diferenças no comportamento alimentar infantil em função do estado nutricional, do sexo e da idade. MÉTODOS: O estudo incluiu crianças na faixa de seis a dez anos, de ambos os sexos, de uma escola privada em Pelotas (RS), em 2012. Para avaliar o comportamento alimentar usaram-se as subescalas do questionário Children's Eating Behaviour Questionnaire (CEBQ): resposta à comida (FR), prazer de comer (EF), desejo de beber (DD), sobreingestão emocional (EOE), subingestão emocional (EUE), resposta à saciedade (SR), seletividade (FF) e ingestão lenta (SE). Avaliou-se o estado nutricional por meio do escore-z do IMC/idade. RESULTADOS: Participaram 335 crianças de 87,9±10,4 meses. Apresentaram eutrofia 49,3% (n=163), sobrepeso 26% (n=86), obesidade 15% (n=50) e obesidade grave 9,7% (n=32). Crianças com excesso de peso tiveram maior pontuação nas subescalas de "interesse pela comida" (FR, EF, DD, EOE, p<0,001) e menor pontuação nas subescalas de "desinteresse pela comida" (SR e SE, p<0,001 e p=0,003, respectivamente), se comparadas com as crianças com peso adequado. Não foram observadas diferenças no comportamento alimentar segundo sexo e idade. CONCLUSÕES: Observou-se que comportamentos alimentares que refletem "interesse pela comida" estão associados positivamente ao excesso de peso, mas não foi encontrada associação com o sexo e a idade da criança. .

Complementary data on four methods for sampling free-living ticks in the Brazilian Pantanal / Dados complementares de quatro métodos para amostragem de carrapatos em vida livre no Pantanal brasileiro

In this study, four methods for sampling free-living ticks that are used in ecological and human tick-bite risk studies were evaluated. Cloth dragging, carbon dioxide traps and visual searches and inspection of plant litter on the ground were used in field and forest areas within the Brazilian Pantanal. Among the three tick species collected, Amblyomma sculptum predominated, followed by Amblyomma parvum and Amblyomma ovale. Dragging, a cheap and simple technique, yielded the highest numbers of ticks, particularly nymphs. The visual search detected a high number of adult ticks and provided information on tick questing height. Even though laborious, plant litter examination showed that large numbers of ticks may use this stratum. Carbon dioxide (CO2) traps are expensive and difficult to handle, but they are highly efficient for adult ticks, especially A. parvum. These data indicate that one method alone is incapable of providing a representative sample of the tick fauna in a particular area and that multiple techniques should be used for tick population studies.

Neste estudo, foram avaliados quatro métodos de amostragem de carrapatos em vida livre, usados em estudos ecológicos e avaliação do risco de picadas em humanos. Arraste de flanela, armadilhas de gás carbônico (CO2), busca visual e inspeção de serrapilheira foram aplicados em áreas campestres e florestais no Pantanal brasileiro. Dentre três espécies coletadas, a predominância foi de Amblyomma sculptum, seguida por Amblyomma parvum e Amblyomma ovale. O arraste, técnica simples e de baixo custo, resultou em maior número de carrapatos, particularmente de ninfas. A busca visual detectou alto número de carrapatos adultos e forneceu informações sobre altura de espera por hospedeiros. Apesar de trabalhoso, o exame da serrapilheira demonstrou que grande número de carrapatos pode utilizar esse estrato. Armadilhas de CO2 têm custo elevado e são difíceis de manusear, entretanto, são altamente eficientes para carrapatos adultos, em especial para A. parvum. Esses dados indicam que somente um método é incapaz de fornecer amostra representativa da ixodofauna em uma área particular e que, para estudos populacionais, técnicas múltiplas devem ser usadas.

Endoparasites of horses from the Formiga city, located in center-west region of the state of Minas Gerais, Brazil / Endoparasitas de equinos provenientes do município de Formiga, localizado na região Centro-oeste do estado de Minas Gerais, Brasil

With the aim of studying the endoparasite fauna of horses from the Formiga city, located in center-west region of the state of Minas Gerais, 25 animals that were naturally infected with helminths were evaluated. By means of parasitological necropsies, different endoparasites were found. The subfamily Cyathostominae presented the highest incidence, followed by Trichostrongylus axei, Oxyuris equi, Triodontophorus serratus, Strongyloides westeri, Strongylus edentatus, Habronema muscae, Parascaris equorum, Probstmayria vivipara, Strongylus vulgaris, Gasterophilus nasalis, Anoplocephala magna and Anoplocephala perfoliata. In the present study, if the species Probstmayria vivipara was not considered in the prevalence, the frequency of Cyathostominae was equivalent to 94.85%. The results obtained in this study allowed us to detect and identify different species of helminths in horses, and confirmed the high incidence of nematodes belonging to the subfamily Cyathostominae in the center-west region of Minas Gerais.

Com o objetivo de estudar a fauna de endoparasitas de equinos da Região Centro-Oeste do Estado de Minas Gerais, 25 animais naturalmente infectados por helmintos foram avaliados. Por meio de necropsias parasitológicas, diferentes endoparasitas foram identificados. A sub - família Cyathostominae apresentou maior incidência, seguido por Trichostrongylus axei, Oxyuris equi, Triodontophorus serratus, Strongyloides westeri, Strongylus edentatus, Habronema muscae, Parascaris equorum, Probstmayria vivipara, Strongylus vulgaris, Gasterophilus nasalis, Anoplocephala magna e Anoplocephala perfoliata. No presente estudo, se não for considerada a espécie Probstmayria vivipara na prevalência, a frequência de Cyathostominae é equivalente a 94,85%. Os resultados obtidos neste estudo, permitiu detectar e identificar diferentes espécies de helmintos em equinos, bem como confirmar a elevada incidência de nematódeos pertencentes à sub-família Cyathostominae na Região Centro-Oeste de Minas Gerais.

Cuidar da saúde do vizinho: atuação do antropólogo Charles Wagley no Serviço Especial de Saúde Pública* / Caring for the health of your neighbor: the work of anthropologist Charles Wagley with the Serviço Especial de Saúde Pública

Recupera a atuação do antropólogo Charles Wagley como alto funcionário do Serviço Especial de Saúde Pública, programa de cooperação estabelecido entre EUA e Brasil na Segunda Guerra Mundial. Convocado a colaborar nos esforços de guerra, atuou na política de migração do Programa da Borracha. À luz dessa experiência de intervenção, do contexto marcado pela promoção do desenvolvimento e por questões então prementes no campo da antropologia, este estudo propõe-se retomar a obra Uma comunidade amazônica. Trata-se de discutir o estudo de comunidade conduzido na localidade amazônica que Wagley conheceu ainda durante as missões do Serviço e cuja realidade considerou ilustrativa de uma região subdesenvolvida, levando-o a refletir sobre mudança social e o papel das ciências.

The article focuses on the work of Charles Wagley as a top staff member with Serviço Especial de Saúde Pública (Special Public Health Service), a US-Brazil cooperation program established during World War II. Taking into consideration Wagley’s experience with migration policy under Brazil’s Rubber Program, as well as the context of development promotion and the issues then on the anthropological agenda, the article explores Wagley’s community study of the Amazon town he visited while on SESP missions, published in the book Uma comunidade amazônica (Amazon Town). Encountering a reality that he believed emblematic of underdevelopment, Wagley was led to reflect on social change and the role of science.

The methyl ester of rosuvastatin elicited an endothelium-independent and 3-hydroxy-3-methylglutaryl coenzyme A reductase-independent relaxant effect in rat aorta

The relaxant effect of the methyl ester of rosuvastatin was evaluated on aortic rings from male Wistar rats (250-300 g, 6 rats for each experimental group) with and without endothelium precontracted with 1.0 µM phenylephrine. The methyl ester presented a slightly greater potency than rosuvastatin in relaxing aortic rings, with log IC50 values of -6.88 and -6.07 M, respectively. Unlike rosuvastatin, the effect of its methyl ester was endothelium-independent. Pretreatment with 10 µM indomethacin did not inhibit, and pretreatment with 1 mM mevalonate only modestly inhibited the relaxant effect of the methyl ester. Nω-nitro-L-arginine methyl ester (L-NAME, 10 µM), the selective nitric oxide-2 (NO-2) inhibitor 1400 W (10 µM), tetraethylammonium (TEA, 10 mM), and cycloheximide (10 µM) partially inhibited the relaxant effect of the methyl ester on endothelium-denuded aortic rings. However, the combination of TEA plus either L-NAME or cycloheximide completely inhibited the relaxant effect. Inducible NO synthase (NOS-2) was only present in endothelium-denuded aortic rings, as demonstrated by immunoblot with methyl ester-treated rings. In conclusion, whereas rosuvastatin was associated with a relaxant effect dependent on endothelium and hydroxymethylglutaryl coenzyme A reductase in rat aorta, the methyl ester of rosuvastatin exhibited an endothelium-independent and only slightly hydroxymethylglutaryl coenzyme A reductase-dependent relaxant effect. Both NO produced by NOS-2 and K+ channels are involved in the relaxant effect of the methyl ester of rosuvastatin.

[Study of the effect of light and heat on rosuvastatin calcium stability]

The effect of light on the stability of rosuvastatin was investigated by exposing rosuvastatin powder to white light [neon light] between 100 to 3000 Luxes for 3 days, according to health and safety requirements. In addition, five series of rosuvastatin powder was exposed, for 3 days, to different colors of light: White, blue, green, orange and red, with intensity 1000 Luxes. Also, the effect of heat on stability of rosuvastatin was studied. Three series were stored in the dark for 24 hours. The first series was stored without any additive under heat temperatures 30, 40, 50, 60 and 90°C with HR 100%. The second series was conducted under the same previous conditions of humidity and temperatures with 20% Calcium ascorbate as an anti oxidant. The third one was incubated in dry heat under the same temperatures, without any additive. All samples were analyzed using HPLC with a column C18 octadecyl, [250 mm X 4.6 mm]. The Studies have shown that rosuvastatin starts to deteriorate when exposed to white light, intensity of 200 Luxes for three days. The percentage of deteriorated rosuvastatin increases to reach more than 50% as light intensity increase to 3000 luxes. The study shows that the increase of temperature with the existence of humidity [relative humidity 100%] destroys rosuvastatin, and the addition of calcium ascorbat improves its stability in these conditions, while dry temperature up to 90° has no negative effect on its stability, and the lights [white, green, blue] destroy mainly Rosuvastatin, on the other side the lights red and orange have no any destroying effect on it, therefore we can use these lights [red and orange] successfully for lighting the laboratories and production sections during its preparation and its control in drugs factories for conservation its stability

Analysis of binding energy activity of imatinib and Abl tyrosine kinase domain based on simple consideration for conformational change: An explanation for variation in imatinib effect in mutated type.

Imatinib is a clinically well-tolerated small molecule inhibitor that exerts selective, dual inhibition on the transforming growth factor beta and platelet-derived growth factor pathways. The recognition of an inactive conformation of Abl, in which a catalytically important Asp-Phe-Gly motif is flipped by approximately 180 degrees with respect to the active conformation, underlies the specificity of the cancer drug imatinib, which is used to treat chronic myelogenous leukemia. However, conformational analysis shows that the effect of the drug depends on the potential energy, which varies due to the alpha rotatable angles of the Abl tyrosine kinase domain. In this study, the author determines the change of binding energy between the Abl tyrosine kinase domain, due to the variation in rotatable angles, and bond lengthening. According to this study, the ratio between the required binding energy between the wild and mutated types is equal to 1: 1.16.

Bases biomoleculares do fotoenvelhecimento: [revisão] / Molecular basis of photoaging: [review]

Com o aumento da expectativa de vida, o estudo do processo de envelhecimento orgânico tem sido estimulado. O envelhecimento da pele, órgão que espelha os sinais do tempo, é processo de deterioração progressiva, tempo-dependente, e pode ser intensificado pela exposição solar, então designado fotoenvelhecimento. O dano das radiações sobre diversas estruturas celulares e cutâneas leva a alterações morfológicas nesses componentes, fruto de modificações biomoleculares. Muitas pesquisas são desenvolvidas com o intuito de combater ou minimizar os efeitos do fotoenvelhecimento, porém a principal estratégia nesse sentido continua sendo a prevenção, só conseguida pelo progressivo desvendar dos mecanismos fisiopatogênicos envolvidos nesse processo.

As a result of the increase in life expectancy, the study of the organic process of aging has been stimulated. Skin ageing, which reflects the signs of time, is a time-dependent process of progressive deterioration that can be intensified by sun exposure, which is known as photoaging. The damage of radiation on various cell structures and on the skin results in molecular and morphological changes to these components. Many research studies are performed to try to minimize the effects of photoaging; however, the main strategy to manage it is still prevention, which will only be achieved once we learn about the mechanisms involved in the process.

Treatment of invasive fungal infections: stability of voriconazole infusion solutions in PVC bags

Voriconazole is a novel broad-spectrum antifungal drug, employed in the treatment of invasive fungal infections, and represents an alternative to amphotericin B treatment. The manufacturer recommends that any unused reconstituted product should be stored at 2ºC to 8ºC, for no more than 24 h, but no recommendations about i.v. infusion solutions are given. Previous works have reported on the stability of voriconazole in polyolefin bags and just one in 5 percent dextrose polyvinyl chloride (PVC) bags, at a 4 mg.mL-1 concentration. In this work, the stability of voriconazole as an i.v. infusion solution in 0.9 percent sodium chloride and in 5 percent dextrose, in PVC bags, at 0.5 mg.mL-1, stored at 4 ºC and at room temperature, protected from light, was evaluated. These infusion solutions were analyzed for a 21-day period. Chemical stability was evaluated by HPLC assay. Visual inspection was performed and pH of the solutions was measured. No color change or precipitation in the solutions was observed. The drug content remained above 90 percent for 11 days in 0.9 percent sodium chloride and for 9 days in 5 percent dextrose solutions. The i.v. infusion solutions stored at room temperature were not stable. At room temperature, the voriconazole content dropped down to 88.3 and 86.6 percent, in 0.9 percent sodium chloride or 5 percent dextrose solutions, respectively, two days after admixture. Assays performed at the end of the study suggest the sorption of voriconazole by the PVC bags. The results of this study allow cost-effective batch production in the hospital pharmacy.

Heterocycles from 2-Amino-4-[3,4,5-trimethoxy-phenyl]-Naphtho[2,1-b]-4H-pyran-3-carbonitrile

The TITLE compound 1 was prepared and subjected to react with different electrophilic reagents such as phenyl isothiocyanate, benzoyl chloride, 2-cyanocinnamonitrile, ethoxymethylenediethyl- malonate, formamide and carbon disulphide to give the naphtha-pyranopyrimidine derivative 3, naphtha [2,1-b]-4H-pyran derivative 7-9, naphtha [2,1-b]-4H-pyranopyrimidine 10 and naphtha [2,1-b]-4H-pyrano-1,3-thiazine derivative 11, respectively. Treatment of 3 with ethyl bromoacetate and hydrazine hydrate afforded 4 and 5. The hydrazine derivative 5 reacted with benzoylacetone and yielded the pyrazole derivative 6. The IR, [1]H-NMR and Mass spectra of the synthesized compounds were discussed

Study of the interaction surface for the c-Src-imatinib complex by a molecular dicing technique.

With the beginning of the new millennium, a new and exciting era for cancer therapy has begun with the appearance of molecular targeted drugs. Imatinib is a clinically well-tolerated small molecule that exerts selective, dual inhibition of the transforming growth factor beta (TGFbeta) and platelet-derived growth factor (PDGF) pathways. Imatinib is also suggested as a chemopreventive for recurrent and metastatic malignancies. An interesting point to be clarified regarding the mechanism of imatinib is its interaction with c-Src. Fortunately, complexing of c-Src and imatinib has recently reported, which provides a basis for further study of the interactions between the two molecules. In the present study, the author used the technique named molecular dicing to study the interaction surface between the two molecules. Accordingly, the interaction surface in c-Scr and imatinib could be identified.

Reaction of substituted pyrimidines with photochemically generated t-BuO* radicals.

Humans are exposed to various organic peroxides through chemical, pharmaceutical and cosmetic products. On photolysis, these peroxides produce alkoxyl radicals and hydroxyl radicals. The reaction of *OH radicals with DNA and its constituents have been extensively studied, but very little is known about the reactions of alkoxyl radicals with DNA and its constituents. In view of this, the oxidation of pyrimidine bases viz., thymine, uracil, cytosine, 5-bromouracil, 6-methyluracil and 1,3-dimethyluracil by t-BuO* radicals in aqueous solution at pH 7.5 has been carried out. The reaction between pyrimidine and t-BuO* is followed by measuring the absorbance of pyrimidine at the respective lambdamax. The rates of oxidation of pyrimidines are calculated from the plot of absorbance vs time. The rates of oxidation of pyrimidines have been found to increase with increase in [t-BuOOH], [pyrimidine] and light intensity. The quantum yields are calculated from the initial rates of oxidation of pyrimidine and the measured light intensity at 254 nm the wavelength at which t-BuOOH is activated to give radicals. The quantum yields are found to depend on [pyrimidine] as well as on [t-BuOOH] while they are independent of light intensity. The product analysis was carried out on HPLC with UV-visible detector. The corresponding 5,6-dihydroxypyrimidine and isobarbituric acid have been identified by comparing the retention times of the authentic samples. On the basis of experimental results and product analysis, it is suggested that t-BuOOH on photolysis gives t-BuO* radical, which initiates the reaction by adding to C (5) or C (6) position of pyrimidine base, leading to the formation of pyrimidine base radical via hydrolysis. The pyrimidine radical further reacts with t-BuO* radical to give the final product. This study predicts the probable transient pyrimidine radicals.

Phosphate radical induced oxidation of pyrimidine bases in aqueous solution.

The photooxidation of pyrimidine bases viz., uracil and cytosine in presence of peroxydiphosphate (PDP) in aqueous solution at natural pH (approximately 7.5) has been carried out in a quantum yield reactor using a high-pressure mercury lamp. The rates of oxidation and quantum yields of pyrimidine oxidation have been found to increase with increase in [PDP] while they are independent of [pyrimidine] and light intensity. On the basis of these experimental results, product analysis and existence of isosbestic points a probable mechanism is suggested in which peroxydiphosphate ion on photolysis gives phosphate radical anions which initiates the reaction by adding to C(5) or C(6) of pyrimidine base leading to the formation of pyrimidine radical via radical cation or hydrolysis. This further reacts with PDP and gives the final products 5,6-dihydroxy pyrimidine and isobarbituric acid.

Synthsis, antimicrobial and antifungal activities of some pyrimidine derivatives

Several chalcones derivatives [1] were prepared from 2, 4-dimethoxyacetophenone, when beta-[4-substituted phenyl]-2, 4-dimethoxyacrylophenone [1] reacted with guanidine hydrochloride, thiourea and urea afforded aminopyrimidine [2], pyrimidinethione [7] and oxopyrimidine [8], respectively. Furthermore, compounds [2], [7] and [8] were subjected to different reactions yielding different pyrimidine derivatives. Representative members of these compounds were subjected to preliminary antimicrobial and antifungal screening and most of these compounds showed significant activities

Synthesis and antimicrobial activity of certain pyrimidine derivatives

Hydrazinolysis of 3 gave compounds 4, 5 and 6 according to reaction conditions. Certain fused pyrimidine derivatives such as triazolo compound [7] and tetrazolo [8] were obtained from the reaction of 4 with CS2/NaOH and NaNO2/HCL, respectively. Refluxing 4 with chloroacetyl chloride yielded compounds 13 and 15 according to reaction conditions. On the other h and, reacting 3, 5 and 6 with some aldehydes gave 9a-e, 17a-e and 22a-g. Treating 5 with acetyl acetyl acetone and isothiocyanates afforded compounds 18 and 19a, b, respectively. Condensation of 1, 4, 5 and 6 with p-toluene sulfonyl chloride furnished 11, 12, 16 and 21, respectively. The benzyl derivative [23] was converted into the chloroderivative [24] which was reacted with some amines to yield 25. Also, compound 26 was obtained from 23. Some of the synthesized compounds were screened for their antimicrobial activity

Similarities inferred from the studies of long range correlations among mitochondrial DNA sequences.

Existence of long range correlations within the DNA sequences of living organism has immense importance in understanding the language of DNA sequences. Recently it has been reported that long range correlations occur in DNA sequences. Some investigators claimed that these type of correlations occur only on intron containing DNA sequences. Some observers, however, have the opinion that long range correlations do not distinguish between the intron containing DNA sequences and intronless DNA sequences. The biological origin of long range correlations in the DNA sequences is not clearly known. In this paper we have demonstrated that long range correlations also occur on intronless mitochondrial DNA sequences, indicating that these special type of correlations are not the unique features for intron containing DNA sequences. We have also demonstrated that long range correlations simply originate in the region around which there is a large variation of pyrimidine and purine ratios. The similarities among the mitochondrial DNA sequences can be inferred by computing the fractal exponents in the region where there is a large variation of pyrimidine and purine ratio, as well as in the region where the ratio of pyrimidine and purine fluctuates in a nearly constant manner. In other words the similarities among the mitochondrial DNA sequences cannot be inferred by calculating the fractral exponents for the whole sequence.

Synthesi of 3-Heterocyclic-5,6-diphenylpyridazines

The reactions of 5,6-diphenyl-3-hydrazinopyridazine with different reagents and methods of synthesis of some of pyridazine derivatives, e.g. 3-[pyrazol-1-yl] pyridazines, 1-[pyridazin-3-yl] pyrazolo [3,4-d] pyrimidines, 3-[pyridazin-3-yl] pyridazines, s-triazolo [4,3-b] pyridazines and tetrazolo [1, 5-b] pyridazines were carried out. The structure were confirmed by spectral methods [IR, 1H-NMR, MS]

Hydrazidoyl halides in heterocyclic synthesis.II+: Synthesis of several new pyrazole, pyrazolo [5,1-c] 1,2,4-Triazine, pyrimidine and thiazole derivatives

Several new pyrazole, pyrazolo [5, 1-c]-1, 2, 4-triazine, pyrimidine and thiazole derivatives were synthesised by the reactions of 2-bromo-1-benzofurylglyoxal-2-[3-phenyl-pyrazol-5-yl]-hydrazone with a variety of reagents. Structures were established by elemental and spectral data

Molecular mechanics studies of homopolymeric and mixed sequence Py.Pu*Pu triple helices.

DNA triple helices containing two purine strands and one pyrimidine strand (C.G*G and T.A*A) have been studied, using model building followed by energy minimisation, for different orientations of the third strand resulting from variation in the hydrogen bonding between the Watson-Crick duplex and the third strand and the glycosidic torsion angle in the third strand. Our results show that in the C.G*G case the structure with a parallel orientation of the third strand, resulting from Hoogsteen hydrogen bonds between the third strand and the Watson-Crick duplex, is energetically the most favourable while in the T.A*A case the antiparallel orientation of the third strand, resulting from reverse Hoogsteen hydrogen bonds, is energetically the most favourable. These studies when extended to the mixed sequence triplexes, in which the second strand is a mixture of G and A, correspondingly the third strand is a mixture of G and A/T, show that though the parallel orientation is still energetically more favourable, the antiparallel orientation becomes energetically comparable with an increasing number of thymines in the third strand. Structurally, for the mixed triplexes containing G and T in the third strand, it is seen that the basepair non-isomorphism between the C.G*G and the T.A*T triplets can be overcome with some changes in the base pair parameters without much distortion of either the backbone or the hydrogen bonds.