HLA-B27 did not protect against COVID-19 in patients with axial spondyloarthritis - data from the ReumaCov-Brasil Registry

BACKGROUND

Some studies have suggested the HLA-B27 gene may protect against some infections, as well as it could play a benefit role on the viral clearance, including hepatitis C and HIV. However, there is lack of SARS-CoV-2 pandemic data in spondyloarthritis (SpA) patients.

AIM

To evaluate the impact of HLA-B27 gene positivity on the susceptibility and severity of COVID-19 and disease activity in axial SpA patients.

METHODS

The ReumaCoV-Brasil is a multicenter, observational, prospective cohort designed to monitor immune-mediated rheumatic diseases patients during SARS-CoV-2 pandemic in Brazil. Axial SpA patients, according to the ASAS classification criteria (2009), and only those with known HLA-B27 status, were included in this ReumaCov-Brasil's subanalysis. After pairing them to sex and age, they were divided in two groups: with (cases) and without (control group) COVID-19 diagnosis. Other immunodeficiency diseases, past organ or bone marrow transplantation, neoplasms and current chemotherapy were excluded. Demographic data, managing of COVID-19 (diagnosis, treatment, and outcomes, including hospitalization, mechanical ventilation, and death), comorbidities, clinical details (disease activity and concomitant medication) were collected using the Research Electronic Data Capture (REDCap) database. Data are presented as descriptive analysis and multiple regression models, using SPSS program, version 20. P level was set as 5%.

RESULTS

From May 24th, 2020 to Jan 24th, 2021, a total of 153 axial SpA patients were included, of whom 85 (55.5%) with COVID-19 and 68 (44.4%) without COVID-19. Most of them were men (N = 92; 60.1%) with mean age of 44.0 ± 11.1 years and long-term disease (11.7 ± 9.9 years). Regarding the HLA-B27 status, 112 (73.2%) patients tested positive. There were no significant statistical differences concerning social distancing, smoking, BMI (body mass index), waist circumference and comorbidities. Regarding biological DMARDs, 110 (71.8%) were on TNF inhibitors and 14 (9.15%) on IL-17 antagonists. Comparing those patients with and without COVID-19, the HLA-B27 positivity was not different between groups (n = 64, 75.3% vs. n = 48, 48%, respectively; p = 0.514). In addition, disease activity was similar before and after the infection. Interestingly, no new episodes of arthritis, enthesitis or extra-musculoskeletal manifestations were reported after the COVID-19. The mean time from the first symptoms to hospitalization was 7.1 ± 3.4 days, and although the number of hospitalization days was numerically higher in the B27 positive group, no statistically significant difference was observed (5.7 ± 4.11 for B27 negative patients and 13.5 ± 14.8 for B27 positive patients; p = 0.594). Only one HLA-B27 negative patient died. No significant difference was found regarding concomitant medications, including conventional or biologic DMARDs between the groups.

CONCLUSIONS

No significant difference of COVID-19 frequency rate was observed in patients with axial SpA regarding the HLA-B27 positivity, suggesting a lack of protective effect with SARS-CoV-2 infection. In addition, the disease activity was similar before and after the infection.

TRIAL REGISTRATION

This study was approved by the Brazilian Committee of Ethics in Human Research (CONEP), CAAE 30186820.2.1001.8807, and was registered at the Brazilian Registry of Clinical Trials - REBEC, RBR-33YTQC. All patients read and signed the informed consent form before inclusion.

Ex vivo UV-vis and FTIR photoacoustic spectroscopy of natural nanoemulsions from cellulose nanocrystals and saponins topically applied into the skin: Diffusion rates and physicochemical evaluation

Nanoemulsions are increasingly gaining importance in the development of topically applied medicine and cosmetic products because their small droplets favor the penetration rates of active compounds into the body. In this scenario, the measurements of their diffusion rates as well as eventual physicochemical changes in the target tissues are of utmost importance. It is also recognized that the use of natural surfactants can avoid allergic reactions as frequently observed for synthetic products. The natural saponins extracted from Sapindus Saponaria have the property of forming foam and are exploited as biocompatible and biodegradable, while cellulose nanocrystals are known to increase the stability of a formulation avoiding the coalescence of drops at the interface. Therefore, nanoemulsions combining natural saponins and cellulose nanocrystals are promising systems that may facilitate greater diffusion rates of molecules into the skin, being candidates to substitute synthetic formulations. This study applied the Photoacoustic Spectroscopy technique to measure the diffusion rates and the physicochemical properties of nanoemulsified formulations containing saponins and cellulose nanocrystals topically applied to the skin. The ex vivo study combined the first-time photoacoustic measurements performed in both ultraviolet-visible and mid-infrared spectral regions. The toxicity of these formulations in L929 cells was also evaluated. The results showed that the formulations were able to propagate throughout the skin to a depth of approximately 756 μm, reaching the dermal side. The non-observation of absorbing band shifting or new bands in the FTIR spectra suggests that there were no structural changes in the skin as well as in the formulations after the nanoemulsions administration. The cytotoxicity results showed that the increase of cellulose nanocrystals concentration decreased cellular toxicity. In conclusion, the results demonstrated the advantage of combining photoacoustic methods in the ultraviolet-visible and mid-infrared spectral regions to analyze drug diffusion and interaction with the skin tissues. Both methods complement each other, allowing the confirmation of the nanoemulsion diffusion through the skin and also suggesting there were no detectable physicochemical changes in the tissues. Formulations stabilized with saponins and cellulose nanocrystals showed great potential for the development of topically administered cosmetics and drugs.

P-661 dydrogesterone as an alternative to supress LH surge in single stimulus protocols with follitropin delta

Study question

Is oral dydrogesterone (DYG) 30 mg daily efficient on prevention of premature luteinizing hormone (LH) surge in ART cycles?

Summary answer

Oral dydrogesterone demonstrated to be as safe and effective as GnRH-ant in IVF/ICSI cycles intended to freeze-all / PGT-A, oocyte preservation and embryo banking programs

What is known already

The use of progesterone (PG) to inhibit pituitary LH surge during ovarian stimulation have been described over the last decades. Due to its harmful effect on the endometrium, PG suppression is mainly reserved for freeze-all cycles. Dydrogesterone (DYG), a known and safe synthetic progesterone, has been tested for this purpose based on the concept of its more selective PG receptors activity, which could reduce the inconveniences of side effects with less relevant androgenic, estrogenic, glyco or mineralocorticoid activity. Accordind to some recent work, DYG would be an effective tool both in cycles intended to freeze-all or in oocyte preservation strategies.

Study design, size, duration

Observational, comparative single center study, comparing the effect of DYG and gonadotropin releasing hormone (GnRH) antagonists on prevention of premature luteinizing hormone (LH) surge as well as to evaluate the number of metaphase II oocytes. From January 2019 to January 2020, 143 no age restrictions patients underwent both IVF/ICSI or oocyte preservation, all of them receiving the same single stimulus protocol with follitropin delta (Rekovelle).

Participants/materials, setting, methods

92 IVF/ICSI plus 51 oocyte cryopreservation cycles underwent deltafollitropin (Rekovelle®, Ferring Pharmaceuticals) in a fixed daily and individualized SC-dose. Clinical decision led to a GnRH-antagonist (CTA-Cetrorelix acetate, Cetrotide®, Merck) 0,25 mg/d initiated in a flexible schedule in presence of one follicle ≥14 mm and continued throughout the stimulation period (48 cycles) or dydrogesterone (DYG), 10mg 8/8 hours (Duphaston®, Abbott) combined to gonadotrophin from the beginning of stimulation until the day after the trigger (95 cycles).

Main results and the role of chance

DYG-group had a mean age significantly higher (37.8 x 35.8-p 0.002) but there were no differences in mean parameters of BMI (24.08 x 24.81), days of stimulation (9.95 x 10.08), AMH (2.30 x 2.52), AFC (14.6 x 16.2). In the same way, no differences were observed between follicles 15 mm to 18 mm (3.06 x 3.68) and ≥ 18 mm (4.56 x 3.9), with a tendency for a greater number of larger follicles in the DYG-group. Metaphase II oocytes (7.48 x 7.33) was similar in both groups. One patient from each group experienced a premature LH surge (3.54 x 3.06) and one case in the DYG-group had no oocyte in a single 20mm aspirated follicle. There happened no cancelling. No patients experienced moderate to severe ovarian hyper stimulation syndrome, even when AMH>3 ng/mL. Cancelling criteria: no follicles with a diameter 17 mm by day 15. Oocyte retrieval took place 36 hours after trigging. Primary outcome was the incidence of premature LH surge. Secondary outcomes included follicles ≥ 15 mm and < 18 mm and ≥ 18 mm on hCG day, metaphase II oocytes, number of cancelled cycles and OHSS symptoms. Statistics were performed by Mann-Whitney test.

Limitations, reasons for caution

The main limitation point is the small number of patients. Despite having relative experience with the use of DYG, in this work we limited the sample to consider only one type of stimulus protocol, making the groups more homogeneous for the analysis.

Wider implications of the findings

Dydrogesterone is as effective as GnRH-ant in reducing premature LH surge. It can be considered for IVF/ICSI cycles intended to freeze-all / PGT-A, oocyte preservation and for embryo banking strategies, representing lower costs in these cases.

Trial registration number

not applicable

The Evaluation of Different Treatments of Incipient Caries Lesions: An in Situ Study of Progression Using Fluorescence-based Methods

CLINICAL RELEVANCE

Effective methods to control incipient caries lesions are needed. In this investigation, several methods provide encouraging results.

SUMMARY

This study aimed to evaluate in situ the inhibition of incipient caries lesion progression using different treatment protocols and to evaluate the effectiveness of fluorescence-based methods (DIAGNOdent, DIAGNOdent pen, and VistaProof fluorescence camera [FC]) in monitoring this process. The research was conducted in four phases: (1) at baseline, (2) after a first cariogenic challenge, (3) after treatment modalities, and (4) after a second cariogenic challenge. Sixteen volunteers used intraoral acrylic palatal appliances, each containing six enamel blocks (n=96). The cariogenic challenge was performed using a 20% sucrose solution over a 14-day period. The appliances were removed eight times a day and, upon removal, two drops of the solution were placed onto each enamel block. The enamel blocks were randomly assigned to three treatment groups: fluoride varnish ([FV] Duraphat; n=32), resin infiltrant ([RI] Icon; n=32), and adhesive system ([AS] Scotchbond; n=32). At the end of each phase, the surface microhardness (SMH) was measured, and two trained examiners evaluated the specimens using fluorescence-based methods. In addition, integrated mineral loss (ΔΔZ; vol%.min x μm) and lesion depth (ΔLD; μm) were evaluated using transverse microradiography. A two-way analysis of variance and a Tukey post hoc test were calculated (α=5%). Significant differences in SMH were observed according to the treatment, phases, and interaction of factors (p<0.001). Treatment with FV resulted in significantly higher SMH values in phases 3 and 4 compared to RI and AS, with the last two treatments resulting in similar values (p>0.05). The ΔΔZ value was similar for FV and AS but significantly higher for RI (p=0.016). ΔLD was not significantly different among the groups (p=0.126). Significant differences in the measurement of fluorescence for each fluorescence-based method were observed between each phase of the study (p<0.05). It can be concluded that all treatments were effective in inhibiting the in situ progression of incipient lesions, although to different degrees, with minor mineral loss changes observed for the AS and FV. Besides, all fluorescence-based methods tested, except for that using the FC device, were effective in monitoring caries lesion progression.

The effect of food insecurity on the prevalence of adult obesity in New Jersey counties

Obesity and food insecurity are prevalent public health concerns that influence factors at both the individual and community levels. Given that obesity is linked to a number of health concerns including heart disease and diabetes, national efforts have been formed to reduce obesity rates among these populations. The purpose of the study is to determine the effect of food-insecure households and associated risk factors on the prevalence of obesity among adults in New Jersey counties. The researchers hypothesized that counties with higher rates of food-secure households and associated risk factors would yield higher rates of obesity among the adult population. An ecological cross-sectional study was performed using secondary data from New Jersey Health Assessment and Census databases focused specifically on all 21 counties in New Jersey. The independent variables were selected from the social indicators available in the datasets consulted: food insecurity rate, physical activity rate, median household income, frequent mental health distress, routine health visit, and percent of adults self-reporting good, very good, or excellent health status. These independent variables were tested against adult obesity rates among New Jersey counties. It was revealed that rising obesity rates among adults were linked to increased rates of food insecurity, lower median household income, and lower perceived health status. Future research may investigate additional social determinants in relation to obesity rates in order to improve public health interventions within communities to increase health outcomes among adults.

Key messages

Obesity and food insecurity are prevalent public health concerns that influence factors at both the individual and community levels. Rising obesity rates among adults are linked to increased rates of food insecurity, lower median household income, and lower perceived health status.

Factors influencing food insecurity rates: A county by county observation from 2017 in New Jersey

This observational study aimed to investigate food insecurity prevalence for children under 18 in New Jersey using secondary data from 2017. Total food insecurity rates per county for children under 18 and all people were gathered from the NJ Department of Health. Age and Sex 5-year estimates for total population and children were collected from the US Census. The median income in the past 12 months from 2013-2017 was collected from the US Census in addition to family poverty status in the past 12 months from 2013-2017. Additional data was collected from the Social Capital Index. A bivariate analysis and a chi-square test revealed that nine independent variables were correlated to food insecurity prevalence by county in New Jersey among children under the age of 18. The significant variables were total food insecurity prevalence for all people in a county (p=.000), median income in the past 12 months in 2017 age-adjusted dollars (p=.000), percent of families below the poverty level (p=.000), county-level index (p=.000), family unity (p=.000), institutional health (p=.002), collective efficacy (p=.003), percent of adults over the age of 18 not covered under any type of health coverage (p=.006), and percent of families headed by a single parent (p=.000). Regarding the multivariate analysis, only two variables were still significant. Median income (p=.030) and poverty status (p=.007). These two variables are strongly associated with food insecurity prevalence among children under the age of 18. Health insurance status and household income are correlated with food insecurity. Food insecure children were more likely to live in areas with high deprivation and experience both individual-level poverty and neighborhood deprivation.

Key messages

Median income and poverty status are strongly associated with food insecurity prevalence among children under the age of 18. Food insecure children were more likely to live in areas with high deprivation and experience both individual level poverty and neighborhood deprivation.

A Medium for the Presumptive Detection of Enterobacter sakazakii in Infant Formula: Interlaboratory Study

A standard method for the detection of Enterobacteriaceae was modified for the presumptive detection of Enterobacter sakazakii, and the modified method was validated in an interlaboratory trial with 16 laboratories from 8 European countries. The modification included a differential-elective medium for the isolation of E. sakazakii, consisting of nutrient agar (NA) supplemented with 4-methyl-umbelliferyl α-D-glucoside (α-MUG). A 25 g sample was added to 225 mL buffered peptone water. After incubation at 35° or 37°C for 16 or 20 h, 10 mL nonselective enrichment was transferred into 90 mL selective enrichment. The selective enrichment was streaked on violet-red bile glucose agar (VRBGA) and incubated at 37°C for 24 h. It was streaked in parallel on NA plates supplemented with α-MUG at 50 mg/L and incubated at 25°C for 16 h, and afterwards for an additional 24 h at room temperature in the dark. E. sakazakii appeared as vivid yellow colonies under normal light and showed blue/violet fluorescence under UV light on NA + α-MUG plates. Validation samples represented powdered infant formula without E. sakazakii (blanks) and with low (1–10 colony-forming units [CFU]/25 g) and medium (1–10 CFU/g) contamination levels. All samples contained Pseudomonas aeruginosa and Lactobacillus spp. as background flora. The specificity for blank samples was 100%. The sensitivity of the low contamination level was similar for VRBGA and NA + α-MUG, i.e., 66.7% (66.7% accordance, 53.9% concordance). For the medium level the sensitivities were 96.7% (93.3% accordance, 93.5% concordance) for VRBGA and 98.3% (96.9% accordance, 96.9% concordance) for NA + α-MUG.

Local treatment with ascorbic acid accelerates recovery of post-sutured Achilles tendon in male Wistar rats

Tendon rupture is a very frequent accident involving average people and high-performance athletes. Clinical studies describe tendon recovery as a painful and slow process involving different biochemical and histological events. Ascorbic acid (AA) is a potent antioxidant as well as an important cofactor for collagen synthesis. In the current study, we evaluated if local treatment with AA is able to promote tendon repair in tenotomized rats. Animals were submitted to Achilles tendon rupture followed by surgical suture. Control and AA groups received in loco injection of saline solution (0.9% NaCl) and 30 mM AA, respectively. Histological and functional recovery of Achilles tendon tissue was evaluated at 7, 14, and 21 days post-surgery. Hematoxylin/eosin staining and collagen fluorescence analysis showed intense disarrangement of tendon tissue in the saline group. Tenotomized animals also showed hypercellularity in tendon tissue compared with non-tenotomized animals. The Achilles functional index (AFI) showed a significant decrease of tendon functionality in tenotomized animals at 7, 14, and 21 days post-surgery. AA accelerated tissue organization and the recovery of function of the Achilles tendons. The beneficial effect of AA treatment was also observed in the organization of the collagen network. Data presented in the current work showed that in loco treatment with AA accelerated the recovery of injured Achilles tendon post-surgery.

Clinical biochemistry of rescued Magellanic Penguins (Spheniscus magellanicus): serum or heparinized plasma?

ABSTRACT In the last few years, an increasing number of debilitated Magellanic penguins (Spheniscus magellanicus) has been rescued and taken to rehabilitation centers on Brazil’s southern coast to be clinically treated and evaluated for re-introduction. This work aims to compare the viability of heparinized plasma with the viability of serum for biochemistry analyses under rehabilitation conditions. Blood sampled from 31 physically healthy rescued penguins was processed into serum/plasma-paired samples and analyzed for 12 biochemical parameters: alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), cholesterol (CHOL), creatine kinase (CK), gamma-glutamyl transpeptidase (GGT), glucose, (GLU) lactate dehydrogenase (LDH), total proteins (TP), triglycerides (TG), urea (UR), and uric acid (UA).The results showed that six paired samples presented visual signs of hemolysis (visual hemolytic score≥1), four of which occurred exclusively in the serum counterpart. Significant differences (P≤ 0.5) between sample types were found for CHOL (3%), GLU (6%) and TG (52%). Only TG was considered clinically relevant (>10%). All mean/median results fell within the available reference intervals by the Association of Zoos and Aquariums (Penguin, 2014). In conclusion, we verified that heparinized plasma is a viable sample for the clinical biochemistry of rescued Magellanic penguins as it yields compatible results with serum, while providing practical benefits. The adoption of this practice favors a faster bird recovery, by minimizing blood sampling volume, and optimizes material resources, allowing use of the same collector tube as for hematology.

Comparison Between Drug Costs for the Systemic Treatment of Metastatic Lung Cancer, Overall Survival Gain and Economic Growth in Brazil

Background: Systemic treatment of patients with metastatic lung cancer is considered a major advancement in the field of oncology. Although undeniable progress has been made in the treatment of such patients, affordability of the more recently implemented treatments, for people in the less developed parts of the world has been questioned. Aim: To expose the disparity between cancer drugs costs, survival gain and economic growth in a developing country (Brazil), using first line therapy to metastatic lung cancer (nonsquamous only without driver mutations) as an example. Methods: First we analyzed the costs of all included first-line systemic therapy regimens from NCCN guidelines for metastatic lung cancer (nonsquamous and no driver mutation identified) over the last two decades, dividing the therapy in five broad categories, each one corresponding to a “generation” of treatment. The following regimens were considered: single-agent chemotherapy (cisplatin), first-generation platinum doublet (cisplatin/carboplatin + etoposide), second-generation platinum doublet (cisplatin/carboplatin + vinorelbine/gemcitabine/docetaxel/paclitaxel), third-generation platinum doublet (cisplatin/carboplatin + pemetrexed) and immunotherapy (pembrolizumab). After that, we identified in the pivotal studies, how much median overall survival cumulative gain was obtained in each generation of treatment in comparison with the last one. Then we compiled the data and compared, in graphics, with economic metrics observed for Brazil during the same period, such as nominal gross domestic product (GDP) growth, GDP per capita and inflation. Results: It was observed that the current choice of first line therapy for metastatic nonsquamous lung cancer, without driver mutation: cisplatin + pemetrexed or immunotherapy (for patients with high PD-L1 expression), now costs more than 130 to 200 times the price of single-agent cisplatin. Median overall survival has been increased from 4-6 months to around 10-12 months (all patients considered) or 30 months (for patients with high PD-L1 expression), with small incremental gains for each generation of treatment. In comparison, Brazilian GDP had an increase of 85% during the same time span, while GDP per capita increased 45%. Conclusion: The exponential rising in the price of the drugs surpassed much of the economic growth of Brazil in the last two decades. Although the observed median overall survival has been steadily increasing during the same time span, reaching now an impressive mark of 30.2 months (for patients with a high level of PD-L1 expression), it is not in the same pace as the cost of the drugs. This provides major questions about affordability and access to such treatments, especially in developing countries with larger populations, even if their economy is rapidly growing.

Resemblance in physical activity levels: The Portuguese sibling study on growth, fitness, lifestyle, and health

OBJECTIVES

To investigate the relationships of biological, behavioral, familial, and environmental characteristics with siblings´ physical activity (PA) levels as well as the intrapair resemblance in PA.

METHODS

The sample comprises 834 (390 females) biological siblings [brother-brother (BB), sister-sister (SS), brother-sister (BS)] aged 9 to 20 years. Total PA index (TPAI) was estimated by questionnaire. Information on potential behavioral, familial, and environmental correlates was obtained by self-report; body mass index (BMI), biological maturation, and physical fitness were measured. Multilevel models were used to analyze siblings´ clustered data, and sibling resemblance was estimated with the intraclass correlation (ρ).

RESULTS

On average, younger sibs, those more physically fit, and those with more parental support had greater TPAI. Further, BB pairs had higher TPAI levels than SS or BS pairs, but also had greater within-pair variance. When adjusted for all covariates, SS pairs demonstrated greater resemblance in TPAI (ρ = 0.53, 95%CI = 0.38-0.68) than BS (ρ = 0.26, 95%CI = 0.14-0.43) or BB pairs (ρ = 0.18, 95%CI = 0.06-0.44).

CONCLUSIONS

Age, physical fitness, and parental support were the best predictors of TPAI levels. A moderate level of resemblance in TPAI was observed in SS pairs, while lower resemblance was found for BS and BB pairs. These findings may be due to differences in the roles of shared genetic factors, familial, and environmental characteristics across different sibling types.

Correlates of children's compliance with moderate-to-vigorous physical activity recommendations: a multilevel analysis

This study aimed to investigate the association between individual and school characteristics associated with the number of school days children comply with moderate-to-vigorous physical activity (MVPA) recommendations. Sample comprises 612 Portuguese children, aged 9-11 years, from 23 schools. Time spent in MVPA was measured by accelerometry, while individual-level correlates were obtained by anthropometry and questionnaires. School-level variables were collected by questionnaire, and accelerometer wear time and season were also considered. Maximum likelihood estimates of model parameters were obtained via a multilevel analysis with children as level-1, and school as level-2. Children who spent more time in sedentary activities and girls were less likely to comply with MVPA/daily. More mature children and those who use active transportation to school were more likely to attain the PA recommendation. Furthermore, greater accelerometer wear time and spring season increased the chance to achieve the recommended MVPA. In terms of school-level correlates, a greater number of available facilities was negatively associated with children MVPA compliance. Given the set of variables, our results showed that individual characteristics seem to be more relevant for children's compliance rates with PA/day than school context variables, which should be taken into account in the implementation of school policies and practices.

Height, weight, body composition, and waist circumference references for 7- to 17-year-old children from rural Portugal

The purpose of this study was (1) to develop references of height, weight, body mass index (BMI), waist circumference and body fat for rural Portuguese children and adolescents and (2) to compare these results with other international references. The sample comprised 3094 children and adolescents aged 7-17 years from Vouzela, a central region in Portugal. Height, weight, BMI, waist circumference and body fat were measured. Centile curves were constructed using the LMS method. The Vouzela sample showed similar height median values compared to Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) percentile curves but greater values for weight and BMI. Percent body fat 50th percentile was greater in Vouzela children and adolescents compared to their international peers, except for boys aged 8-12 years. Boys' waist circumference median values were similar to those from the USA, whilst girls were similar until 12 years of age, after which the differences increased with age. The percentile curves constructed provide population specific references for growth and body composition of children and adolescents from rural Portugal. It is expected that they will be a useful tool for clinical and public health settings in rural Portugal.

QUALIDADE MICROBIOLÓGICA DE QUEIJO MINAS FRESCAL COMERCIALIZADO NO MUNICÍPIO DE SANTA HELENA, PR, BRASIL

RESUMO No período de maio de 2008 a abril de 2009 foi avaliada a qualidade microbiológica de 40 amostras de queijo Minas Frescal produzidas artesanalmente e inspecionadas pelo Serviço de Inspeção Estadual e Federal no Município de Santa Helena, PR, através da quantificação do número mais provável de coliformes termotolerantes, contagem de Staphylococcus spp., pesquisa de bolores e leveduras, presença/ausência de Salmonella spp. e Listeria monocytogenes. Quanto à presença de coliformes termotolerantes, apresentaram-se em desacordo com o estabelecido pela ANVISA segundo a Resolução n° 12 de 02 de janeiro de 2001, 90% das amostras artesanais e 55% das inspecionadas. Em relação à enumeração de Staphylococcus spp., 100% das amostras artesanais e 25% das amostras inspecionadas apresentaram-se em desacordo com o estabelecido pela legislação. Salmonella spp. e Listeria monocytogenes não foram isoladas em 25 g do produto, mostrando que em relação a estes agentes as amostras de queijo analisadas, tanto de produção artesanal quanto as inspecionadas, apresentaram-se dentro dos padrões estabelecidos (ausência em 25 g do produto). Os resultados revelaram que, do total de amostras analisadas, somente 15% apresentaram-se de acordo com os padrões estabelecidos pela ANVISA, estando um número elevado de amostras artesanais (100%) e inspecionadas (70%) fora dos limites estabelecidos pela legislação. Portanto, maior atenção deve ser tomada pelas autoridades sanitárias, uma vez que tais produtos podem colocar em risco a saúde do consumidor.

Search for scalar neutrino superpartners in e+mu final states in pp collisions at sqrt[s]=1.96 TeV

We report a search for R-parity-violating production and decay of sneutrino particles in the emu final state with 1.04+/-0.06 fb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider in 2002-2006. Good agreement between the data and the standard model prediction is observed. With no evidence for new physics, we set limits on the R-parity-violating couplings lambda'311 and lambda312 as a function of the sneutrino mass.

Measurement of the forward-backward charge asymmetry in top-quark pair production

We present the first measurement of the integrated forward-backward charge asymmetry in top-quark-top-antiquark pair (tt) production in proton-antiproton (pp) collisions in the lepton+jets final state. Using a b-jet tagging algorithm and kinematic reconstruction assuming tt + X production and decay, a sample of 0.9 fb(-1) of data, collected by the D0 experiment at the Fermilab Tevatron Collider, is used to measure the asymmetry for different jet multiplicities. The result is also used to set upper limits on tt+X production via a Z' resonance.

Search for ZZ and Zgamma* production in pp[over ] collisions at square root s=1.96 TeV and limits on anomalous ZZZ and ZZgamma* couplings

We present a study of micro micro micro micro, eeee, and micro micro ee events using 1 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp[over ] Collider at square root s=1.96 TeV. Requiring the lepton pair masses to be greater than 30 GeV, we observe one event, consistent with the expected background of 0.13+/-0.03 events and with the predicted standard model ZZ and Zgamma* production of 1.71+/-0.15 events. We set an upper limit on the ZZ and Zgamma* cross section of 4.4 pb at the 95% C.L. We also derive limits on anomalous neutral trilinear ZZZ and ZZgamma* gauge couplings. The one-parameter 95% C.L. coupling limits with a form-factor scale Lambda=1.2 TeV are -0.28<f(40)(Z)<0.28, -0.31<f(50)(Z)<0.29, -0.26<f(40)(gamma)<0.26, and -0.30<f(50)(gamma)<0.28.

Search for flavor-changing-neutral-current d meson decays

We study the flavor-changing-neutral-current process c-->u micro(+) micro(-) using 1.3 fb(-1) of pp[over ] collisions at square root s = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the charged-current mediated D(s)(+) and D(+)-->phipi(+) --> micro(+)micro(-)pi(+) final states with significance greater than 4 standard deviations above background for the D(+) state. We search for the continuum neutral-current decay of D(+)-->pi(+) micro(+) micro(-) in the dimuon invariant mass spectrum away from the phi resonance. We see no evidence of signal above background and set a limit of B(D(+) --> pi(+) micro(+) micro(-))<3.9 x 10(-6) at the 90% C.L. This limit places the most stringent constraint on new phenomena in the c--> u micro(+) micro(-) transition.

Measurement of the shape of the boson-transverse momentum distribution in pp --> Z/gamma* --> e+e- + X events produced at square root s = 1.96 TeV

We present a measurement of the shape of the Z/gamma* boson transverse momentum (q(T)) distribution in pp --> Z/gamma* --> e(+)e(-) + X events at a center-of-mass energy of 1.96 TeV using 0.98 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron collider. The data are found to be consistent with the resummation prediction at low q(T), but above the perturbative QCD calculation in the region of q(T)>30 GeV/c. Using events with q(T)<30 GeV/c, we extract the value of g(2), one of the nonperturbative parameters for the resummation calculation. Data at large boson rapidity y are compared with the prediction of resummation and with alternative models that employ a resummed form factor with modifications in the small Bjorken x region of the proton wave function.

Search for Randall-Sundrum gravitons with 1 fb(-1) of data from pp collisions at sqrt(s)=1.96 TeV

We search for decays of Kaluza-Klein excitations of the graviton in the Randall-Sundrum model of extra dimensions to e+ e(-) and gamma gamma in 1 fb(-1) of pp collisions at sqrt(s)=1.96 TeV collected by the D0 detector at the Fermilab Tevatron. We set 95% confidence level upper limits on the production cross section times branching fraction, which translate into lower limits on the mass of the lightest excitation between 300 and 900 GeV for values of the coupling k/MPl between 0.01 and 0.1.

Observation and properties of the orbitally excited B_(s2)(*) meson

We report the direct observation of the excited L=1 state B_(s2)(*) in fully reconstructed decays to B+K-. The mass of the B_(s2)(*) meson is measured to be 5839.6+/-1.1(stat)+/-0.7(syst) MeV/c(2), and its production rate relative to the B+ meson is measured to be [1.15+/-0.23(stat)+/-0.13(syst)]%.

Search for W' bosons decaying to an electron and a neutrino with the D0 detector

This Letter describes the search for a new heavy charged gauge boson W' decaying into an electron and a neutrino. The data were collected with the D0 detector at the Fermilab Tevatron pp[over] Collider at sqrt[s]=1.96 TeV, and correspond to an integrated luminosity of about 1 fb(-1). Lacking any significant excess in the data in comparison with known processes, an upper limit is set on sigma_(W') x B(W')-->e nu), and a W' boson with mass below 1.00 TeV can be excluded at the 95% C.L., assuming standard-model-like couplings to fermions. This result significantly improves upon previous limits and is the most stringent to date.

Study of the decay Bs(0)-->Ds(*)Ds(*)

We report a study of the decay Bs(0)-->Ds(*)Ds(*) using a data sample corresponding to 1.3 fb(-1) of integrated luminosity collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. One Ds(*) meson was partially reconstructed in the decay Ds-->phi mu nu, and the other Ds(*) meson was identified using the decay Ds-->phi pi where no attempt was made to distinguish Ds and Ds(*) states. For the branching fraction Br(Bs(0)-->Ds(*)Ds(*)) we obtain a 90% C.L. range [0.002,0.080] and central value 0.039(-0.017)(+0.019)(stat)(-0.015)(+0.016)(syst). This was subsequently used to make the most precise estimate of the width difference DeltaGamma(s)CP in the Bs(0)-Bs(0) system: DeltaGamma(s)CP/Gamma(s)=0.079(-0.035)(+0.038)(stat)(-0.030)(+0.031)(syst).

Search for production of single top quarks via tcg and tug flavor-changing-neutral-current couplings

We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb{-1} of lepton+jets data from pp[over] collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters kappa{g}{c}/Lambda and kappa{g}{u}/Lambda, where kappa{g} define the strength of tcg and tug couplings, and Lambda defines the scale of new physics. The limits at 95% C.L. are kappa{g}{c}/Lambda<0.15 TeV-1 and kappa{g}{u}/Lambda<0.037 TeV-1.

Measurement of the Lambdab0 lifetime using semileptonic decays

We report a measurement of the Lambda(b)(0) lifetime using a sample corresponding to 1.3 fb(-1) of data collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. The Lambda(b)(0) baryon is reconstructed via the decay Lambda(b)(0)-->micronuLambda(c)(+)X. Using 4437+/-329 signal candidates, we measure the Lambda(b)(0) lifetime to be tau(Lambda(b)(0))=1.290(-0.110)(+0.119)(stat)(-0.091)(+0.087)(syst) ps, which is among the most precise measurements in semileptonic Lambda(b)(0) decays. This result is in good agreement with the world average value.

Properties of L=1 B(1) and B(2)* mesons

This Letter presents the first strong evidence for the resolution of the excited B mesons B(1) and B(2)* as two separate states in fully reconstructed decays to B(+)(*)pi(-). The mass of B(1) is measured to be 5720.6+/-2.4+/-1.4 MeV/c(2) and the mass difference DeltaM between B(2)* and B(1) is 26.2+/-3.1+/-0.9 MeV/c;{2}, giving the mass of the B(2)* as 5746.8+/-2.4+/-1.7 MeV/c(2). The production rate for B(1) and B(2)* mesons is determined to be a fraction (13.9+/-1.9+/-3.2)% of the production rate of the B+ meson.

Measurement of the Lambda b lifetime in the exclusive decay Lambda b --> J/psi Lambda

We have measured the Lambda b lifetime using the exclusive decay Lambda b --> J/psi Lambda, based on 1.2 fb(-1) of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda b decays, where the J/psi and Lambda are identified via the decays J/psi --> mu+ mu- and Lambda --> ppi, we measured the Lambda b lifetime to be tau(Lambda b)=1.218 (+0.130)/(-0.115) (stat) +/- 0.042(syst) ps. We also measured the B0 lifetime in the decay B0 --> J/psi(mu+ mu-)K(0)/(S)(pi+ pi-) to be tau(B0)=1.501 (+0.078)/(-0.074) (stat) +/- 0.050(syst) ps, yielding a lifetime ratio of tau(Lambda b)/tau(B0)=0.811 (+0.096)/(-0.087) (stat) +/- 0.034(syst).

Search for stopped gluinos from pp collisions at square root s = 1.96 TeV

Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb(-1) of pp collisions at square root(s) = 1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such "stopped gluinos" decaying into a gluon and a neutralino (chi(1)(0)). Limits are placed on the (gluino cross section) x (probability to stop) x [BR(g --> g chi(1)(0))] as a function of the gluino and chi(1)(0) masses, for gluino lifetimes from 30 micros-100 h.