Evaluating TROPOMI and MODIS performance to capture the dynamic of air pollution in São Paulo state: A case study during the COVID-19 outbreak.

Atmospheric pollutant data retrieved through satellite sensors are continually used to assess changes in air quality in the lower atmosphere. During the COVID-19 pandemic, several studies started to use satellite measurements to evaluate changes in air quality in many different regions worldwide. However, although satellite data is continuously validated, it is known that its accuracy may vary between monitored areas, requiring regionalized quality assessments. Thus, this study aimed to evaluate whether satellites could measure changes in the air quality of the state of São Paulo, Brazil, during the COVID-19 outbreak; and to verify the relationship between satellite-based data [Tropospheric NO2 column density and Aerosol Optical Depth (AOD)] and ground-based concentrations [NO2 and particulate material (PM; coarse: PM10 and fine: PM2.5)]. For this purpose, tropospheric NO2 obtained from the TROPOMI sensor and AOD retrieved from MODIS sensor data by using the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm were compared with concentrations obtained from 50 automatic ground monitoring stations. The results showed low correlations between PM and AOD. For PM10, most stations showed correlations lower than 0.2, which were not significant. The results for PM2.5 were similar, but some stations showed good correlations for specific periods (before or during the COVID-19 outbreak). Satellite-based Tropospheric NO2 proved to be a good predictor for NO2 concentrations at ground level. Considering all stations with NO2 measurements, correlations >0.6 were observed, reaching 0.8 for specific stations and periods. In general, it was observed that regions with a more industrialized profile had the best correlations, in contrast with rural areas. In addition, it was observed about 57% reductions in tropospheric NO2 throughout the state of São Paulo during the COVID-19 outbreak. Variations in air pollutants were linked to the region economic vocation, since there were reductions in industrialized areas (at least 50% of the industrialized areas showed >20% decrease in NO2) and increases in areas with farming and livestock characteristics (about 70% of those areas showed increase in NO2). Our results demonstrate that Tropospheric NO2 column densities can serve as good predictors of NO2 concentrations at ground level. For MAIAC-AOD, a weak relationship was observed, requiring the evaluation of other possible predictors to describe the relationship with PM. Thus, it is concluded that regionalized assessment of satellite data accuracy is essential for assertive estimates on a regional/local level. Good quality information retrieved at specific polluted areas does not assure a worldwide use of remote sensor data.

How mobility restrictions policy and atmospheric conditions impacted air quality in the State of São Paulo during the COVID-19 outbreak.

Mobility restrictions are among actions to prevent the spread of the COVID-19 pandemic and have been pointed as reasons for improving air quality, especially in large cities. However, it is crucial to assess the impact of atmospheric conditions on air quality and air pollutant dispersion in the face of the potential variability of all sources. In this study, the impact of mobility restrictions on the air quality was analyzed for the most populous Brazilian State, São Paulo, severely impacted by COVID-19. Ground-based air quality data (PM10, PM2.5, CO, SO2, NOx, NO2, NO, and O3) were used from 50 automatic air quality monitoring stations to evaluate the changes in concentrations before (January 01 - March 25) and during the partial quarantine (March 16 - June 30). Rainfall, fires, and daily cell phone mobility data were also used as supplementary information to the analyses. The Mann-Whitney U test was used to assess the heterogeneity of the air quality data during and before mobility restrictions. In general, the results demonstrated no substantial improvements in air quality for most of the pollutants when comparing before and during restrictions periods. Besides, when the analyzed period of 2020 is compared with the year 2019, there is no significant air quality improvement in the São Paulo State. However, special attention should be given to the Metropolitan Area of São Paulo (MASP), due to the vast population residing in this area and exposed to air pollution. The region reached an average decrease of 29% in CO, 28% in NOx, 40% in NO, 19% in SO2, 15% in PM2.5, and 8% in PM10 concentrations during the mobility restrictions period compared to the same period in 2019. The only pollutant that showed an increase in concentration was ozone, with a 20% increase compared to 2019 during the mobility restrictions period. Before the mobility restrictions period, the region reached an average decrease of 30% in CO, 39% in NOx, 63% in NO, 12% in SO2, 23% in PM2.5, 18% in PM10, and 16% in O3 concentrations when compared to the same period in 2019. On the other hand, Cubatão, a highly industrialized area, showed statistically significant increases above 20% for most monitored pollutants in both periods of 2020 compared to 2019. This study reinforces that the main driving force of pollutant concentration variability is the dynamics of the atmosphere at its various time scales. An abnormal rainy season, with above average rainfall before the restrictions and below average after it, generated a scenario in which the probable significant reductions in emissions did not substantially affect the concentration of pollutants.

Behavioural responses of stable flies to cattle manure slurry associated odourants.

Stable flies (Stomoxys calcitrans [Diptera: Muscidae] L.) are blood-feeding synanthropic pests, which cause significant economic losses in livestock. Stable fly antennae contain olfactory sensilla responsive to host and host environment-associated odours. Field observation indicated that the abundance of stable flies increased significantly in grasslands or crop fields when cattle manure slurry was applied. Major volatile compounds emanating from manure slurry were collected and identified. Behavioural responses of stable flies to those compounds were investigated in laboratory bioassays and field-trapping studies. Results from olfactometer assays revealed that phenol, p-cresol and m-cresol were attractive to adult stable flies. When tested individually, attraction was higher with lower dosages. Stable flies were most attracted to blends of phenol and m-cresol or p-cresol. Traps with binary blend lures caught more stable flies in field trials as well.

Ultra-high pressure LC for astaxanthin determination in shrimp by-products and active food packaging.

Nowadays, there is increasing interest in natural antioxidants from food by-products. Astaxanthin is a potent antioxidant and one of the major carotenoids in crustaceans and salmonids. An ultra-high pressure liquid chromatographic method was developed and validated for the determination of astaxanthin in shrimp by-products, and its migration from new packaging materials to food simulants was also studied. The method uses an UPLC® BEH guard-column (2.1 × 5 mm, 1.7 µm particle size) and an UPLC® BEH analytical column (2.1 × 50 mm, 1.7 µm particle size). Chromatographic separation was achieved using a programmed gradient mobile phase consisting of (A) acetonitrile-methanol (containing 0.05 m ammonium acetate)-dichloromethane (75:20:5, v/v/v) and (B) ultrapure water. This method was evaluated with respect to validation parameters such as linearity, precision, limit of detection, limit of quantification and recovery. Low-density polyethylene films were prepared with different amounts of the lipid fraction of fermented shrimp waste by extrusion, and migration was evaluated into food simulants (isooctane and ethanol 95%, v/v). Migration was not detected under the tested conditions.

Mannose-binding lectin gene (MBL-2) polymorphism in oral lichen planus.

TNF-α may be associated with the etiopathogenesis of oral lichen planus (OLP), and it has been suggested that polymorphism of mannose-binding lectin (MBL) increases the in vitro production of TNF- α. The aim of the present study was to assess the relevance of genetic diversity of MBL in OLP. The study sample comprised 90 individuals, 45 OLP patients and 45 healthy volunteers. MBL-2 gene was amplified using real-time PCR. Frequency of A/A genotype was 55.6% in OLP and 53.3% in healthy volunteers. Likewise, A/0 heterozygote genotype was found in 42.2% and 35.6%; 2.2% and 11.1%, had the recessive 0/0 genotype respectively. Frequencies of the "A" and "0" alleles were 77% and 23% in the OLP group and 71.2% in control group. There were no statistically significant differences regarding genotype frequency (p = 0.546) or allele frequency (p = 0.497). In conclusion, no significant association was found between polymorphism of MBL-2 gene and OLP.

Cancer gene therapy mediated by RALA/plasmid DNA vectors: Nitrogen to phosphate groups ratio (N/P) as a tool for tunable transfection efficiency and apoptosis.

Cancer gene therapy based on p53 tumor suppressor gene supplementation emerges as one of the most challenging and promising strategies. The development of a suitable gene delivery system is imperative to ensure the feasibility and viability of cancer gene therapy in a clinical setting. The conception of delivery systems based on cell- penetrating peptides may deeply contribute for the evolution of therapy efficacy. In this context, the present work explores the p53 encoding plasmid DNA (pDNA) condensation ability of RALA peptide to produce a suitable intracellular delivery platform. These carriers, formed at several nitrogen to phosphate groups (N/P) ratio, were characterized in terms of morphology, size, surface charges, loading and complexation capacity and the fine structure has been analyzed by Fourier-transformed infrared (FTIR) spectroscopy. Confocal microscopy studies confirmed intracellular localization of nanoparticles, resulting in enhanced sustained pDNA uptake. Moreover, in vitro transfection of HeLa cells mediated by RALA/pDNA vectors allows for gene release and p53 protein expression. From these progresses, apoptosis in cancer cells has been investigated. It was found that N/P ratio strongly tailors gene transfection efficiency and, thus, it can be fine-tuned for desired degree of both protein expression and apoptosis. The great asset of the proposed system relies precisely on the use of N/P ratio as a tailoring parameter that can not only modulate vector´s properties but also the extent of pDNA delivery, protein expression and, consequently, the efficacy of p53 mediated cancer therapy.

Correlation between prepulse inhibition and cortical perfusion during an attentional test in schizophrenia. A pilot study.

BACKGROUND: Processes underlying cortical hypoactivation in schizophrenia are poorly understood but some evidence suggests that a deficient sensory filtering is associated with the condition. This filtering deficit can be studied by using measures of prepulse inhibition (PPI) of the startle reflex. OBJECTIVE: To evaluate the contribution of sensory filtering deficits to cortical hypoperfusion during an attention test in schizophrenia. METHOD: Measurements of PPI of the startle reflex and perfusion during the performance of a Stroop test (assessed with single photon emission tomography) were obtained in 10 acutely treated schizophrenia patients (6 with recent onset, RO) and 16 control subjects. These measurements were compared between patients and controls and the correlation between PPI and perfusion was evaluated within each group, using Statistical Parametric Mapping. RESULTS: In comparison with normal subjects, the patients exhibited lower PPI, although the difference was not statistically significant. Perfusion was significantly lower in the prefrontal and premotor regions of the patients. In the patient group, a statistically significant difference was observed between PPI and perfusion in the parietal, premotor, and cingulate regions. When the associations were analyzed in the RO patients alone, a positive correlation was also found between prefrontal perfusion and PPI, while anterior hippocampal perfusion was inversely related to PPI. CONCLUSIONS: These results support the notion that deficient sensory-motor filtering is associated with decreased cortical task-related activation in schizophrenia.

Challenges in the rabbit haemorrhagic disease 2 (RHDV2) molecular diagnosis of vaccinated rabbits.

Molecular methods are fundamental tools for the diagnosis of viral infections. While interpretation of results is straightforward for unvaccinated animals, where positivity represents ongoing or past infections, the presence of vaccine virus in the tissues of recently vaccinated animals may mislead diagnosis. In this study, we investigated the interference of RHDV2 vaccination in the results of a RT-qPCR for RHDV2 detection, and possible associations between mean Cq values of five animal groups differing in age, vaccination status and origin (domestic/wild). Viral sequences from vaccinated rabbits that died of RHDV2 infection (n=14) were compared with the sequences from the commercial vaccines used in those animals. Group Cq means were compared through Independent t-test and One-way ANOVA. We proved that RHDV2 vaccine-RNA is not detected by the RT-qPCR as early as 15days post-vaccination, an important fact in assisting results interpretation for diagnosis. Cq values of vaccinated and non-vaccinated infected domestic adults showed a statistically significant difference (p<0.05), demonstrating that vaccination-induced immunity reduces viral loads and delays disease progression. Contrarily, in vaccinated young rabbits higher viral loads were registered compared to non-vaccinated kittens. No significant variation (p=0.3824) was observed between viral loads of non-vaccinated domestic and wild RHDV2-victimised rabbits. Although the reduced number of vaccinated young animals analysed hampered a robust statistical analysis, this occurrence suggests that passively acquired maternal antibodies may inhibit the active immune response to vaccination, delaying protection and favouring disease progression. Our finding emphasises the importance of adapting kitten RHDV2 vaccination schedules to circumvent this interference phenomenon.

Detection of virulence-associated genes in pathogenic and commensal avian Escherichia coli isolates.

Poultry colibacillosis due to Avian Pathogenic Escherichia coli (APEC) is responsible for several extra-intestinal pathological conditions, leading to serious economic damage in poultry production. The most commonly associated pathologies are airsacculitis, colisepticemia, and cellulitis in broiler chickens, and salpingitis and peritonitis in broiler breeders. In this work a total of 66 strains isolated from dead broiler breeders affected with colibacillosis and 61 strains from healthy broilers were studied. Strains from broiler breeders were typified with serogroups O2, O18, and O78, which are mainly associated with disease. The serogroup O78 was the most prevalent (58%). All the strains were checked for the presence of 11 virulence genes: 1) arginine succinyltransferase A (astA); ii) E.coli hemeutilization protein A (chuA); iii) colicin V A/B (cvaA/B); iv) fimbriae mannose-binding type 1 (fimC); v) ferric yersiniabactin uptake A (fyuA); vi) iron-repressible high-molecular-weight proteins 2 (irp2); vii) increased serum survival (iss); viii) iron-uptake systems of E.coli D (iucD); ix) pielonefritis associated to pili C (papC); x) temperature sensitive haemaglutinin (tsh), and xi) vacuolating autotransporter toxin (vat), by Multiplex-PCR. The results showed that all genes are present in both commensal and pathogenic E. coli strains. The iron uptake-related genes and the serum survival gene were more prevalent among APEC. The adhesin genes, except tsh, and the toxin genes, except astA, were also more prevalent among APEC isolates. Except for astA and tsh, APEC strains harbored the majority of the virulence-associated genes studied and fimC was the most prevalent gene, detected in 96.97 and 88.52% of APEC and AFEC strains, respectively. Possession of more than one iron transport system seems to play an important role on APEC survival.

Sex-Related Differences in Rat Choroid Plexus and Cerebrospinal Fluid: A cDNA Microarray and Proteomic Analysis.

The choroid plexus (CP) epithelium is a unique structure in the brain that forms an interface between the peripheral blood and the cerebrospinal fluid (CSF), which is mostly produced by the CP itself. Because the CP transcriptome is regulated by the sex hormone background, the present study compared gene/protein expression profiles in the CP and CSF from male and female rats aiming to better understand sex-related differences in CP functions and brain physiology. We used data previously obtained by cDNA microarrays to compare the CP transcriptome between male and female rats, and complemented these data with the proteomic analysis of the CSF of castrated and sham-operated males and females. Microarray analysis showed that 17 128 and 17 002 genes are expressed in the male and female CP, which allowed the functional annotation of 141 and 134 pathways, respectively. Among the most expressed genes, canonical pathways associated with mitochondrial dysfunctions and oxidative phosphorylation were the most prominent, whereas the most relevant molecular and cellular functions annotated were protein synthesis, cellular growth and proliferation, cell death and survival, molecular transport, and protein trafficking. No significant differences were found between males and females regarding these pathways. Seminal functions of the CP differentially regulated between sexes were circadian rhythm signalling, as well as several canonical pathways related to stem cell differentiation, metabolism and the barrier function of the CP. The proteomic analysis identified five down-regulated proteins in the CSF samples from male rats compared to females and seven proteins exhibiting marked variation in the CSF of gonadectomised males compared to sham animals, whereas no differences were found between sham and ovariectomised females. These data clearly show sex-related differences in CP gene expression and CSF protein composition that may impact upon neurological diseases.

Impairment of Interleukin-17A Expression in Canine Visceral Leishmaniosis is Correlated with Reduced Interferon-γ and Inducible Nitric Oxide Synthase Expression.

Dogs are the primary urban reservoir of Leishmania infantum and play a crucial role in the transmission of this parasite to man via sandflies. The spleen and liver are the main target organs of L. infantum infection, but few studies have evaluated the immune response to this infection in the canine liver. To identify the immunological mediators involved in resistance and/or susceptibility to canine visceral leishmaniosis (CVL), we selected 21 dogs naturally infected by L. infantum and classified as asymptomatic or symptomatic. Immunological parameters were analysed and correlations with clinical signs were determined. Symptomatic dogs showed higher numbers of parasites and less leucocyte infiltration in the liver compared with asymptomatic dogs. The progression of this disease was characterized not only by the down regulation of T helper (Th) 1-related cytokines, such as interferon (IFN)-γ and tumour necrosis factor (TNF)-α, but also by the down regulation of genes encoding interleukin (IL)-17A, inducible nitric oxide synthase (iNOS) and IL-10 in the spleen and liver in symptomatic dogs compared with asymptomatic dogs. Importantly, IL-17A gene transcription level was positively correlated with mRNA expression for iNOS and IFN-γ. Th1- and Th17-related cytokines therefore appear to play a role in restricting parasite growth via iNOS activation and decrease susceptibility of dogs to CVL.

Development of an orange juice in-house reference material and its application to guarantee the quality of vitamin C determination in fruits, juices and fruit pulps.

Reference materials are useful for the quality control of analytical procedures and to evaluate the performance of laboratories. There are few and expensive certified reference materials commercially available for vitamin C or ascorbic acid analysis in food matrices. In this study, the preparation and the suitability assessment of an orange juice in-house reference material (RM) for vitamin C analysis in fruits, juices and in fruit pulps is described. This RM was used for the development and full validation of an HPLC method. The results showed excellent linearity (r(2)=0.9995), good accuracy (96.6-97.3%) and precision, as relative standard deviation, ranged from 0.70% to 3.67%. The in-house RM was homogenous and stable at storage conditions (-80°C) during 12 months. According to our results, this in-house RM is an excellent tool to use in quality control and method verification purposes for vitamin C analysis of fruits, juices and fruit pulps matrices. Furthermore, a stabilization solution with perchloric and metaphosphoric acids was developed which prevents degradation of ascorbic acid for a period of 12 months at -80°C.

Infection control in households of drug-resistant tuberculosis patients co-infected with HIV in Mumbai, India.

BACKGROUND: Mumbai has a population of 21 million, and an increasingly recognised epidemic of drug-resistant tuberculosis (DR-TB). OBJECTIVE: To describe TB infection control (IC) measures implemented in households of DR-TB patients co-infected with the human immunodeficiency virus (HIV) under a Médecins Sans Frontières programme. METHODS: IC assessments were carried out in patient households between May 2012 and March 2013. A simplified, standardised assessment tool was utilised to assess the risk of TB transmission and guide interventions. Administrative, environmental and personal protective measures were tailored to patient needs. RESULTS: IC assessments were carried out in 29 houses. Measures included health education, segregating sleeping areas of patients, improving natural ventilation by opening windows, removing curtains and obstacles to air flow, installing fans and air extractors and providing surgical masks to patients for limited periods. Environmental interventions were carried out in 22 houses. CONCLUSIONS: TB IC could be a beneficial component of a comprehensive TB and HIV care programme in households and communities. Although particularly challenging in slum settings, IC measures that are feasible, affordable and acceptable can be implemented in such settings using simplified and standardised tools. Appropriate IC interventions at household level may prevent new cases of DR-TB, especially in households of patients with a lower chance of cure.

Contexte : A Mumbai, population 21 millions, on voit une épidémie de plus en plus reconnue de tuberculose pharmacorésistante (TB-DR).Objectif : Décrire les mesures de lutte contre l'infection (IC) pour la TB mises en place dans les foyers de patients DR-TB coinfectés par le virus de l'immunodéficience humaine (VIH) dans le cadre d'un programme de Médecins Sans Frontières à Mumbai.Méthodes : L'évaluation des mesures de lutte a été réalisée dans les foyers des patients entre mai 2012 et mars 2013. Un outil d'évaluation simplifié a permis d'évaluer le risque de transmission de la TB et de guider les interventions. Les mesures de protection administratives, environnementales et personnelles ont été adaptées aux besoins de chaque patient.Résultats : Ces évaluations ont été réalisées dans 29 foyers. Les mesures mises en œuvre incluaient l'éducation sanitaire, le couchage séparé des patients, une amélioration de la ventilation naturelle par l'ouverture des fenêtres et l'enlèvement des rideaux et autres obstacles à la circulation de l'air, l'installation de ventilateurs et d'extracteurs d'air et la fourniture de masques chirurgicaux pour une durée limitée. Les interventions environnementales ont été réalisées dans 22 maisons.Conclusions: Les mesures IC pour la TB pourraient constituer un élément bénéfique d'un programme intégré de soins de la TB et du VIH dans les foyers et les communautés. Bien qu'il s'agisse d'un défi particulier dans les bidonvilles, des mesures faisables, abordables et acceptables peuvent être mis en œuvre dans ce contexte grâce à des outils simplifiés et standardisés. Des mesures appropriées à domicile peuvent contribuer à éviter de nouveaux cas, surtout dans les foyers des patients qui ont moins de chances de guérison.

Marco de referencia: Mumbai cuenta con una población de 21 millones de habitantes, y presenta una epidemia cada vez más reconocida de tuberculosis farmacorresistente (TB-DR).Objetivo: Describir las medidas de control de la infección (IC) para la TB que se aplican en los hogares de los pacientes coinfectados por el virus de la inmunodeficiencia humana (VIH) y la TB-DR, en el marco del programa de Médicos Sin Fronteras en Mumbai.Métodos: De mayo del 2012 a marzo del 2013 se evaluaron las medidas de IC de la TB en los hogares de los pacientes. Se aplicó un instrumento simplificado normalizado, con el fin de evaluar el riesgo de transmisión de la TB y orientar las intervenciones. Las medidas administrativas, ambientales y de protección personal se adaptaron a las necesidades de los pacientes.Resultados: Se practicaron evaluaciones del IC en 29 casas. Las medidas comportaron educación sanitaria, separación de los espacios donde duermen los pacientes, optimización de la ventilación natural mediante la abertura de las ventanas, la eliminación de las cortinas y los obstáculos al flujo del aire, la instalación de ventiladores y extractores de aire y el suministro de mascarillas de quirófano a los pacientes durante un período limitado. Se llevaron a cabo intervenciones ambientales en 22 casas.Conclusiones: El IC para la TB puede constituir un componente útil de un programa integral de atención de la TB y la infección por el VIH en los hogares y las comunidades. Aunque las intervenciones plantean dificultades en el contexto de las viviendas precarias, se pueden introducir medidas de IC que sean factibles, abordables y aceptables en estos entornos, mediante la utilización de instrumentos sencillos y normalizados. Las intervenciones adecuadas a escala de los hogares también pueden prevenir la aparición de nuevos casos de TB-DR, sobre todo en los hogares de los pacientes con menos probabilidades de curación.

Efeito da suplementação de suínos em terminação com diferentes associações entre minerais sobre o desempenho, as características de carcaça e a viabilidade econômica / Effect of supplementation of finishing swines with different associations between minerals on performance, carcass characteristics and economic viability

Objetivou-se, com este estudo, verificar a influência da suplementação com diferentes associações entre minerais orgânicos sobre o desempenho e as características de carcaça, bem como avaliar sua viabilidade econômica, para suínos em terminação. Foram utilizados 88 machos castrados, divididos entre quatro tratamentos: controle com dieta basal e suplementação com CrFe, MgSe e CrFeMgSe, durante os 28 dias que antecederam o abate. O delineamento experimental foi em blocos ao acaso, com parcela experimental representada por dois animais. Os animais suplementados com CrFeMgSe apresentaram piores índices de peso final, ganho de peso diário e consumo durante todo o período, com consequente redução no peso de carcaça, menor profundidade de lombo, área de olho-de-lombo e menor quantidade de carne magra na carcaça. Houve um aumento no custo da dieta para os grupos CrFe, MgSe e CrFeMgSe, respectivamente. O uso de cromo mais ferro e magnésio mais selênio, associados dois a dois, não altera os parâmetros de desempenho e as características de carcaça. A associação dos quatro minerais, no entanto, promove piora nessas características e aumenta o custo da dieta.(AU)

This study aimed to verify the influence of supplementation with different associations between organic minerals on performance, carcass characteristics and economic viability for finishing swine. 88 castrated males were divided in four treatments: control with basal diet and supplementation with CrFe, MgSe and CrFeMgSe during the 28 days prior to slaughter. The experimental design was randomized blocks with an experimental plot represented by two animals. The animals supplemented with CrFeMgSe had worse final weight, daily weight gain and consumption throughout the period, with consequent reduction in carcass weight, lower loin depth, loin eye area and amount of lean meat. There was an increase in the effective operational cost of diet with CrFe, MgSe and CrFeMgSe groups, respectively. The use of chromium plus iron and magnesium plus selenium, associated two by two, did not alter the performance parameters and carcass. However, the four minerals association promote a worsening in these characteristics and increase the cost of production.(AU)

Hyperphagia resulting from gut denervation in the sea slug, Pleurobranchaea.

Previous research suggests that gut distension by ingested bulk plays an important role in the regulation of food intake in gastropod molluscs. The present study tested whether the bilateral stomatogastric nerves which innervate the esophagus and crop in Pleurobranchaea form a neural pathway carrying information about gut distension to the central nervous system. The posterior branches of the paired stomatogastric nerves were surgically exposed and sectioned in seven experimental animals while the nerves were simply exposed and not sectioned in seven sham-operated control animals. In three, subsequent, daily feeding sessions, the experimental subjects consumed a greater amount of food in terms of percentage of body weight than the control subjects. The experimental animals also gained a greater percentage of body weight and later were found to contain much more food within their guts. The results support the hypothesis that stretch receptors which innervate the gut and which have axons in the stomatogastric nerves form an important negative feedback pathway for the control of feeding in the sea slug.

The Dental Hygiene Program in Portugal.

The Dental Hygiene Program is a fairly recent addition in the field of the health professions in Portugal. In the past 19 years, the programme has developed community activities alongside with clinical work. This programme provides an education that is responsive, scientific and professional, in a learning environment that is dynamic, student-centred and that encourages collaboration between students and faculty. The community activities play a major role in the curricula of the programme and allow the students to develop skills in working with a wide range of population groups and to attend to their specific needs. Dental hygienists are integrated in health teams and work under the supervision of a physician or a dentist. Among other responsibilities, the following functions are part of the scope of the profession: to participate in health education programmes and sensitise the population to the prevention of dental diseases, to participate in the planning, implementation, and evaluation of the public health programmes and to perform clinical treatment for prevention and control of gingivitis, periodontitis, and dental caries. An overview of the activities developed in the year 2002 and future perspectives are presented in this article.

Atividade antimicrobiana in vitro do extrato de Anacardium occidentale L. sobre espécies de Streptococcus / In vitro antimicrobial activity of an extract of Anacardium occidentale L. against Streptococcus species

A atividade antimicrobiana do extrato da casca do caule de Anacardium occidentale L., foi avaliada em três culturas de bactérias isoladas de biofilme dental. A atividade antimicrobiana foi conduzida em placa de Petri pelo método de difusão para determinação da Concentração Inibitória Mínima (CIM) e Concentração Inibitória Mínima de Aderência (CIMA). Inibição aureolar (CIM) foi observada com concentrações de 12,5 mg/mL em S. mutans e 6,25mg/mL em S. mitis e S. sanguis. Os resultados sugerem que o extrato tem efeito na CIMA em concentrações de 0,31 mg/mL em S. mutans e S. mitis e de 0,15 mg/mL em S. sanguis e pode ser usado terapeuticamente na odontologia como agente antibacteriano.

The antimicrobial activity of the extract of the stem bark of Anacardium occidentale L., was evaluated in three cultures of bacteria of the dental plate. The antimicrobial activity was assayed in Petri dishes using the diffusion method for determination of the minimal inhibitory concentration (MIC) and minimal inhibitory concentration of adherence (MICA). Aureolar inhibition (MIC) was observed with concentrations of 12.5 mg/mL in S. mutans and 6.25 mg/mL in S. mitis and S. sanguis. The results suggest that the extract has effect in the MICA in concentrations of 0.31 mg/mL in S. mutans and S. mitis and of 0.15 mg/mL in S. sanguis and therapeuticly can be used in the dentistry as an antibacterial agent.