Thermal decomposition of mercerized linter cellulose and its acetates obtained from a homogeneous reaction

Cellulose acetates with different degrees of substitution (DS, from 0.6 to 1.9) were prepared from previously mercerized linter cellulose, in a homogeneous medium, using N,N-dimethylacetamide/lithium chloride as a solvent system. The influence of different degrees of substitution on the properties of cellulose acetates was investigated using thermogravimetric analyses (TGA). Quantitative methods were applied to the thermogravimetric curves in order to determine the apparent activation energy (Ea) related to the thermal decomposition of untreated and mercerized celluloses and cellulose acetates. Ea values were calculated using Broido's method and considering dynamic conditions. Ea values of 158 and 187 kJ mol-1 were obtained for untreated and mercerized cellulose, respectively. A previous study showed that C6OH is the most reactive site for acetylation, probably due to the steric hindrance of C2 and C3. The C6OH takes part in the first step of cellulose decomposition, leading to the formation of levoglucosan and, when it is changed to C6OCOCH3, the results indicate that the mechanism of thermal decomposition changes to one with a lower Ea. A linear correlation between Ea and the DS of the acetates prepared in the present work was identified.

Polychaete assemblage of an impacted estuary, Guanabara Bay, Rio de Janeiro, Brazil

Thirty-eight stations were sampled in Guanabara Bay, Rio de Janeiro, Brazil, to assess the spatio-temporal diversity and biomass of sublittoral polychaetes. Samples were collected during the dry (September 2000) and rainy season (May 2001) in shallow sublittoral sediments. The polychaete spatial composition showed a heterogeneous distribution throughout the bay. A negative gradient of diversity and biomass was observed towards the inner parts of the bay and sheltered areas. A wide azoic area was found inside the bay. Some high-biomass and low-diversity spots were found near a sewage-discharge point. In these areas, the polychaete biomass increased after the rainy season. A diversified polychaete community was identified around the bay mouth, with no dramatic changes of this pattern between the two sampling periods. Deposit-feeders were dominant in the entire study area. The relative importance of carnivores and omnivores increased towards the outer sector, at stations with coarse sediment fractions. Guanabara Bay can be divided into three main zones with respect to environmental conditions and polychaete diversity and biomass patterns: A) High polychaete diversity, hydrodynamically exposed areas composed of sandy, oxidized or moderately reduced sediments with normoxic conditions in the water column. B) Low diversity and high biomass of deposit and suspension-feeding polychaete species in the middle part of the bay near continental inflows, comprising stations sharing similar proportions of silt, clay and fine sands. C) Azoic area or an impoverished polychaete community in hydrodynamically low-energy areas of silt and clay with extremely reduced sediments, high total organic matter content and hypoxic conditions in the water column, located essentially from the mid-bay towards the north sector. High total organic matter content and hypoxic conditions combined with slow water renewal in the inner bay seemed to play a key role in the polychaete diversity and biomass. Sedimentation processes and organic load coming from untreated sewage into the bay may have negatively affected the survivorship of the fauna.

Color/race inequalities in oral health among Brazilian adolescents

This study assessed oral health outcomes (perceived dental treatment need, untreated dental caries, gingival bleeding, periodontal pockets, and pain in teeth and gums), in relation to color/race inequalities among adolescents in each Brazilian region. The database included dental examination and interview of 16,833 15-19-year-old adolescents, surveyed by the Brazilian health authority, from May 2002 to October 2003, in accordance with international diagnostic criteria standardized by the World Health Organization. Prevalence ratios estimated by Poisson regression, and controlled by socioeconomic status and access to fluoridated piped water, assessed oral health differentials among color/race groups and country's regions. Except for periodontal pockets, prevalence figures were higher in the North and Northeast: perceived dental treatment needs, untreated dental caries, gingival bleeding at probing and pain in teeth and gums varied between 80-83%, 75-76%, 38-43%, and 17-18%, respectively, in these regions. Adolescents living in the Southeast - the richest Brazilian region - presented a better general profile of oral health than their counterparts living in the remaining regions; they had a lower prevalence of untreated dental caries (54%) and unfavorable gingival status (29%). However, the Southeast presented color/race inequalities in all oral health outcomes, with a poorer profile systematically affecting browns or blacks, depending on the oral health condition under consideration. These results reinforce the need for expanding the amplitude of health initiatives aimed at adolescent oral health. Socially appropriate health programs should concurrently aim at the reduction of levels of oral disease and its inequalities.

Transtornos psiquiátricos no pós-parto

OBJETIVO: O pós-parto é um período de alterações biológicas, psicológicas e sociais. Essa é considerada a época mais vulnerável para a ocorrência de transtornos psiquiátricos. A disforia puerperal, a depressão pós-parto e a psicose pós-parto têm sido classicamente relacionadas ao pós-parto. Atualmente, tem sido observado que os transtornos ansiosos também estão associados a esse período. MÉTODO: Neste artigo é feita uma revisão da bibliografia acerca de transtornos psiquiátricos no pós-parto a partir de artigos encontrados no PubMed e no SciELO entre os anos de 2000 e 2009. Livros, teses e outros artigos considerados relevantes citados no material consultado também foram incluídos. RESULTADOS: A disforia puerperal ocorre em 50% a 85% das mulheres, o quadro é leve e transitório e não requer tratamento. A depressão pós-parto tem prevalência em torno de 13%, pode causar repercussões negativas na interação mãe-bebê e em outros aspectos da vida da mulher e deve ser tratada. A psicose pós-parto é rara, aparecendo em cerca de 0,2% das puérperas. Tem quadro grave que envolve sintomas psicóticos e afetivos, havendo risco de suicídio e infanticídio e geralmente requerendo internação hospitalar. Os transtornos ansiosos podem ser exacerbados ou precipitados no pós-parto, especialmente o transtorno de ansiedade generalizada, o transtorno de estresse pós-traumático e o transtorno obsessivo-compulsivo. CONCLUSÃO: Apesar de não serem reconhecidos como entidades diagnósticas pelos sistemas classificatórios atuais, os transtornos mentais no puerpério apresentam peculiaridades clínicas que merecem atenção por parte de clínicos e pesquisadores.

Prevalência de cárie não tratada na dentição decídua em áreas urbanas e rurais do Estado de São Paulo, Brasil

OBJETIVO: Descrever os diferenciais urbano-rurais da prevalência de cárie dentária em crianças com dentição decídua no Estado de São Paulo e identificar fatores associados. MÉTODOS: Participaram do estudo 24 744 crianças de 5 a 7 anos examinadas no Levantamento Epidemiológico de Saúde Bucal do Estado de São Paulo. Utilizou-se a análise multinível para verificar se havia associação entre a prevalência de cárie não tratada e as características sociodemográficas das crianças examinadas ou os aspectos socioeconômicos das cidades participantes. RESULTADOS: Ser negro ou pardo (razão de chances, ou OR, ajustada = 1,27), estudar na área rural (OR ajustada = 1,88) e freqüentar a escola pública (OR ajustada = 3,41) foram identificados como determinantes individuais de chance mais elevada de apresentar um ou mais dentes decíduos com cárie não tratada. Ser do sexo feminino (OR ajustada = 0,83) foi identificado como fator de proteção para essa condição. Os coeficientes negativos obtidos para as variáveis independentes de segundo nível indicaram que o perfil de saúde bucal das cidades participantes se beneficiou de valores mais elevados de índice de desenvolvimento humano municipal (b = -0,47) e da adição de flúor à rede de águas (b = -0,32). CONCLUSÕES: A prevalência de cárie não tratada é influenciada por fatores sociodemográficos de ordem individual e contextual. O presente estudo apresenta informações epidemiológicas das áreas rurais do Estado de São Paulo, oferecendo subsídios para o planejamento estratégico e normativo das ações de saúde bucal nos sistemas locais de saúde, com o intuito de contribuir para a promoção de eqüidade em saúde bucal

Metabolic osteopathy in celiac disease: importance of a gluten-free diet

Reduced bone mineral density (BMD) is frequently found in individuals with untreated celiac disease (CD), possibly due to calcium and vitamin D malabsorption, release of pro-inflammatory cytokines, and misbalanced bone remodeling. A gluten-free diet (GFD) promotes a rapid increase in BMD that leads to complete recovery of bone mineralization in children. Children may attain normal peak bone mass if the diagnosis is made and treatment is given before puberty, thereby preventing osteoporosis in later life. A GFD improves, but rarely normalizes, BMD in patients diagnosed with CD in adulthood. In some cases, nutritional supplementation may be necessary. More information on therapeutic alternatives is needed

Topochemical distribution of lignin and hydroxycinnamic acids in sugar-cane cell walls and its correlation with the enzymatic hydrolysis of polysaccharides

Background: Lignin and hemicelluloses are the major components limiting enzyme infiltration into cell walls. Determination of the topochemical distribution of lignin and aromatics in sugar cane might provide important data on the recalcitrance of specific cells. We used cellular ultraviolet (UV) microspectrophotometry (UMSP) to topochemically detect lignin and hydroxycinnamic acids in individual fiber, vessel and parenchyma cell walls of untreated and chlorite-treated sugar cane. Internodes, presenting typical vascular bundles and sucrose-storing parenchyma cells, were divided into rind and pith fractions. Results: Vascular bundles were more abundant in the rind, whereas parenchyma cells predominated in the pith region. UV measurements of untreated fiber cell walls gave absorbance spectra typical of grass lignin, with a band at 278 nm and a pronounced shoulder at 315 nm, assigned to the presence of hydroxycinnamic acids linked to lignin and/or to arabino-methylglucurono-xylans. The cell walls of vessels had the highest level of lignification, followed by those of fibers and parenchyma. Pith parenchyma cell walls were characterized by very low absorbance values at 278 nm; however, a distinct peak at 315 nm indicated that pith parenchyma cells are not extensively lignified, but contain significant amounts of hydroxycinnamic acids. Cellular UV image profiles scanned with an absorbance intensity maximum of 278 nm identified the pattern of lignin distribution in the individual cell walls, with the highest concentration occurring in the middle lamella and cell corners. Chlorite treatment caused a rapid removal of hydroxycinnamic acids from parenchyma cell walls, whereas the thicker fiber cell walls were delignified only after a long treatment duration (4 hours). Untreated pith samples were promptly hydrolyzed by cellulases, reaching 63% of cellulose conversion after 72 hours of hydrolysis, whereas untreated rind samples achieved only 20% hydrolyzation. Conclusion: The low recalcitrance of pith cells correlated with the low UV-absorbance values seen in parenchyma cells. Chlorite treatment of pith cells did not enhance cellulose conversion. By contrast, application of the same treatment to rind cells led to significant removal of hydroxycinnamic acids and lignin, resulting in marked enhancement of cellulose conversion by cellulases.

Measurement of fungicide efficacy on post-harvest diseases: wound anthracnose, quiescent anthracnose, crown rot

Introduction. This protocol aims at evaluating (a) the efficacy of new fungicides for the control of post-harvest diseases, (b) the efficacy of various application methods for the chemical control of post-harvest diseases, and (c) the quality of the fungicide solution during the same packing day where this solution is recycled. The principle, key advantages, starting plant material, time required and expected results are presented. Materials and methods. Materials required and details of the eighteen steps of the protocol (fruit sampling and inoculum preparation, wound anthracnose study, quiescent anthracnose study, and crown-rot study) are described. Results. Comparison between untreated control bananas and bananas treated with fungicide allows the calculation of the fungicide treatment efficacy.

A Novel Organotellurium Compound (RT-01) as a New Antileishmanial Agent

Leishmaniasis is a neglected disease and endemic in developing countries. A lack of adequate and definitive chemotherapeutic agents to fight against this infection has led to the investigation of numerous compounds. The aim of this study was to investigate the effect of RT-01, an organotellurane compound presenting biological activities, in 2 experimental systems against Leishmania amazonensis. The in vitro system consisted of promastigotes and amastigotes forms of the parasite, and the in vivo system consisted of L. amazonensis infected BALB/c mice, an extremely susceptible mouse strain. The compound proved to be toxic against promastigotes and amastigotes. The study also showed that treatment with RT-01 produces an effect similar to that treatment with the reference antimonial drug, Glucantime, in L. amazonensis infected mice. The best results were obtained following RT-01 intralesional administration (720 mu g/kg/day); mice showed significant delay in the development of cutaneous lesions and decreased numbers of parasites obtained from the lesions. Significant differences in tissue pathology consisted mainly of no expressive accumulation of inflammatory cells and well-preserved structures in the skin tissue of RT-01-treated mice compared with expressive infiltration of infected cells replacing the skin tissue in lesions of untreated mice. These findings highlight the fact that the apparent potency of organotellurane compounds, together with their relatively simple structure, may represent a new avenue for the development of novel drugs to combat parasitic diseases.

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and high plasma homocysteine in chronic hepatitis C (CHC) infected patients from the Northeast of Brazil

Background/Aim: Hyperhomocysteinemia due to Methylenetetrahydrofolate Reductase (MTHFR) gene, in particular the C677T (Ala222Val) polymorphism were recently associated to steatosis and fibrosis. We analyzed the frequency of MTHFR gene in a cross-sectional study of patients affected by Chronic Hepatitis C (CHC) from Northeast of Brazil. Method: One hundred seven-four untreated patients with CHC were genotyped for the C677T MTHFR. Genomic DNA was extracted from peripheral blood cells and the C677T MTHFR polymorphism was identified by PCR-RFLP. The homocysteine (Hcy) levels were determined by chemiluminescence method. All patients were negative for markers of Wilson's disease, hemochromatosis and autoimmune diseases and have current and past daily alcohol intake less than 100 g/week. Results: Among subjects infected with CHC genotype non-1 the frequency of MTHFR genotypes TT was 9.8% versus 4.4% genotype 1 (p = 0.01). Nevertheless, association was found between the MTHFR genotype TT x CT/CC polymorphism and the degree of steatosis and fibrosis in both hepatitis C genotype (p < 0.05). A significant difference was found on plasma Hcy levels in patients with steatosis regardless of HCV genotype (p = 0.03). Conclusion: Our results indicate that plasma Hcy levels is highly prevalent in subjects with chronic hepatits C with steatosis regardless of HCV genotype and vitamin deficiency. The presence of genotype TT of MTHFR C677T polymorphism was more common in CHC genotype non-1 infected patient regardless of histopathological classification and genotype TT+CT frequencies were significant in the presence of fibrosis grade 1+2 and of steatosis in CHC infected patients from the northeast of Brazil regardless of HCV genotype. The genetic susceptibility of MTHFR C677T polymorphism should be confirmed in a large population.

Prognostic factors for progression of liver structural lesions in chronic hepatitis C patients

AIM: To evaluate the epidemiological, clinical, laboratory and histological variables capable of predicting the progression of hepatic structural disturbances in chronic hepatitis C patients during the time interval between two liver biopsies. METHODS: Clinical charts of 112 chronic hepatitis C patients were retrospectively analyzed, whereas liver biopsies were revised. Immunohistochemical detection of interferon receptor was based on the Envision-Peroxidase System. RESULTS: In the multivariate analysis, the variables in the age at first biopsy, ALT levels, presence of lymphoid aggregates and siderosis were the determinants of the best model for predicting the severity of the disease. The direct progression rate of hepatic structural lesions was significantly higher in untreated patients, intermediate in treated non-responders and lower in treated responders to antiviral therapy (non-treated vs responders, 0.22 +/- 0.50 vs -0.15 +/- 0.46, P = 0.0053). Immuno-expression of interferon receptor is not a relevant factor. CONCLUSION: The best predictors of the progression of fibrosis are age at the first liver biopsy, extent of ALT elevation, inflammation at liver histology and hepatic siderosis. Antiviral treatment is effective in preventing the progression of liver structural lesions in chronic hepatitis C patients. (C) 2008 WJG. All rights reserved.

The Effects of Commercially Available Preservative-Free FDA-Approved Triamcinolone (Triesence (R)) on Retinal Cells in Culture

Purpose: To evaluate the effects of Triesence (R) (TRI), a new preservative-free triamcinolone approved by the U. S. Food and Drug Administration (FDA) for intraocular use, on human retina pigment epithelial (ARPE-19) and rat neurosensory (R28) cells in culture. Methods: ARPE-19 and R28 cell cultures were treated 24 h with 1,000, 500, 200, or 100 mu g/mL of crystalline (cTRI) or 1,000, 500, or 200 mu g/mL of solubilized (sTRI). TRI was solubilized by centrifuging the drug, discarding the supernatant containing the vehicle and then resuspending the drug pellet in an equivalent amount of Dimethyl sulfoxide to achieve the same concentration as the commercial preparation. Percentage of cell viability (CV) was evaluated by a trypan blue dye-exclusion assay. The mitochondrial membrane potential (Delta Psi m) was analyzed with the JC-1 assay. The caspase-3/7 activity was measured by a fluorochrome assay. Results: In the ARPE-19 cultures, the cTRI caused a decrease in CV at 1,000 mg/mL (13.03 +/- 6.51; P < 0.001), 500 mu g/mL (28.87 +/- 9.3; P < 0.001), 200 mu g/mL (54.93 +/- 5.61; P < 0.001), and 100 mu g/mL (82.53 +/- 0.65; P < 0.005) compared with the untreated controls (96.98 +/- 0.16). In R28 cultures, the cTRI treatment also reduced CV values significantly (P < 0.001) for the 1,000 mu g/mL (22.73 +/- 2.44), 500 mu g/mL (34.63 +/- 1.91), 200 mu g/mL (58.70 +/- 1.39), and 100 mu g/m (75.33 +/- 2.47) compared with the untreated controls (86.08 +/- 3.54). Once the TRI was solubilized (sTRI), the CV and Delta Psi m remained similar to the untreated controls for both ARPE-19 and R28 cells. The sTRI treatment with 1,000, 500, and 200 mu g/mL increased in caspase-3/7 activity in ARPE-19 cells (P < 0.01) and in R28 cells (P < 0.05) compared with dimethyl sulfoxide equivalent controls. Conclusion: The crystalline form of TRI (cTRI) can cause a significant decrease in CV to cultured retinal cells. Once the TRI is solubilized (sTRI), at the same concentrations, the cells remain viable with no decrease in CV or Delta Psi m. The sTRI can, however, increase caspase-3/7 activity, thus suggesting some degree of apoptosis.

Challenges and opportunities for primary, secondary, and tertiary prevention of Chagas' disease

A century after its discovery, Chagas' disease still represents a major public health challenge in Latin America. Moreover, because of growing population movements, an increasing number of cases of imported Chagas' disease have now been detected in non-endemic areas, such as North America and some European countries. This parasitic zoonosis, caused by Trypanosoma cruzi, is transmitted to humans by infected Triatominae insects, or occasionally by non-vectorial mechanisms, such as blood transfusion, mother to fetus, or oral ingestion of materials contaminated with parasites. Following the acute phase of the infection, untreated individuals enter a chronic phase that is initially asymptomatic or clinically unapparent. Usually, a few decades later, 40-50% of patients develop progressive cardiomyopathy and/or motility disturbances of the oesophagus and colon. In the last decades several interventions targeting primary, secondary and tertiary prevention of Chagas' disease have been attempted. While control of both vectorial and blood transfusion transmission of T cruzi (primary prevention) has been successful in many regions of Latin America, early detection and aetiological treatment of asymptomatic subjects with Chagas' disease (secondary prevention) have been largely underutilised. At the same time, in patients with established chronic disease, several pharmacological and non-pharmacological interventions are currently available and have been increasingly used with the intention of preventing or delaying complications of the disease (tertiary prevention). In this review we discuss in detail each of these issues.

High-Dose Antipsychotic Medication; A Practical Pocket Checklist

There is evidence that a significant number of patients with schizophrenia and other chronic psychotic psychosis are prescribed high-dose antipsychotic drugs despite the fact that clinical guidelines recommend the routine use of a single antipsychotic drug in a standard dose. The prescriptions for high-dose and combined antipsychotic drugs are relatively common in clinical practice. This occurs despite the fact that results of published trials of high-dose antipsychotic drug treatment for schizophrenia provide little evidence to support effectiveness of using high-dose antipsychotic treatment and most importantly such strategy is not recommended. Moreover, there is mounting evidence of higher incidence of side effects and mortality associated with high dose antipsychotic treatment. Therefore we are presenting a practical pocket checklist which is aimed at minimizing predicted and unpredicted side effects during such treatments.

VIABILITY OF SPORULATED OOCYSTS OF NEOSPORA CANINUM AFTER EXPOSURE TO DIFFERENT PHYSICAL AND CHEMICAL TREATMENTS

The aim of the present study was to evaluate the viability of Neospora caninum sporulated oocysts after various chemical and physical treatments. Bioassays in gerbils and molecular techniques (PCR-RFLP) were used for identification of the oocysts shed by experimentally infected dogs. Sporulated oocysts were purified and divided into 11 treatment groups as follows: absolute ethanol for 1 hr; 20 C for 6 hr; 4 C for 6 hr; 60 C for 1 min; 100 C for 1 min; 10% formaldehyde for 1 hr; 10% ammonia for 1 hr; 2% iodine for 1 hr; 10% sodium hypochlorite for I hr; 70% ethanol for I hr; and one group was left untreated and kept as a positive control. All chemical treatments were performed at room temperature (37 C). A total of 33 gerbils, or 3 gerbils per treatment, were used for bioassays. After treatment, the oocysts were divided into aliquots of 1,000 oocysts and orally administered to gerbils. After 63 days, the gerbils were anesthetized and killed with 0.2 ml of T61; blood and tissue samples were collected for serological (IFAT and western blotting), molecular (real-time PCR), histopathology, and immunohistochemical tests. Treatments were considered effective only if all 5 detection techniques tested negative. High temperatures at 100 C for 1 min and 10% sodium hypochlorite for 1 hr were the only treatments that met this condition, effectively inactivating all oocysts.