Recording and erasure of photorefractive holograms in undoped BTO crystal at moderate to high intensities of 639.7 nm laser under action of 532 nm laser pre-illumination.

We investigate recording and erasure of photorefractive holographic gratings in an undoped Bi12TiO20 crystal in a moderate to high intensity regime of the recording beams at 639.7 nm without and with the action of laser pre-illumination at 532 nm. The detected hologram without pre-illumination indicates the participation of two photorefractive electronic gratings in its recording process, and the diffracted signal by itself exhibits a fivefold enhancement when the total intensity increases from 38.4 to 214.5 mW/cm2. The dependence of the measured total diffraction efficiency on intensity was investigated and showed linear behavior. At least three gratings are present in the regime of pre-illumination and participate in the writing and erasure of holographic mechanisms. Two of them are electronic, and one is hole-based, with a phase difference of Δϕ between them. The theoretical approach used to analyze the total diffraction efficiency based upon the photorefractivity standard model, and considering the presence of the three gratings, showed good agreement with the holographic erasure experimental data and permitted us to compute Δϕ, which exhibited strong and unusual dependence on the total intensity.

Multicentre evaluation of a direct agglutination test prototype kit (DAT-LPC) for diagnosis of visceral leishmaniasis.

In this study, we assessed the sensitivity, specificity, and diagnostic accuracy of a previously developed direct agglutination test (DAT) using a freeze-dried antigen derived from Leishmania infantum promastigotes and composed in a prototype kit for visceral leishmaniasis (VL) diagnosis, named DAT-LPC. To evaluate DAT-LPC reproducibility, the kit was used to analyse 207 serum samples from VL patients and 80 serum samples from patients with other parasitic infections or healthy subjects in four laboratories from different public health institutions in Brazil. DAT-LPC showed sensitivity between 96·2 and 99·5% (P = 0·14), specificity ranging from 96·2 to 97·5% (P = 0·95), and diagnostic accuracy ranging from 96·5 to 99% (P = 0·34). The inter-laboratory reproducibility of qualitative results was classified as excellent (κ index: 0·94-0·97). The reproducibility of the end-titre results in relation to the reference laboratory, ranged from 31 to 85%. These results demonstrate an excellent performance of the DAT-LPC, and validate it for the diagnosis of VL that could replace the immunofluorescent antibody test as the routine diagnostic test in the Brazilian public health system.

Effects of beta-glucans ingestion (Saccharomyces cerevisiae) on metabolism of rats receiving high-fat diet.

We investigated the effects of beta-glucans (Saccharomyces cerevisiae) ingestion on metabolic parameters of Wistar rats receiving high-fat diet. The experimental period was divided into two stages: in the first one, the animals were divided into two groups containing 12 animals each. The first group received commercial feed and the second received high-fat diet containing 20% of pork fat during 60 days. At the end of this period, body weight, blood glucose and Lee index were assessed. In the second stage, those 24 animals were redivided into four groups: (C) - control diet; (CB) - control diet and treated with Beta-glucan (BG); (O) - obese animals and (OB) - obese animals treated with BG. Animals from groups CB and OB received 30 mg/kg of BG dissolved in saline solution by gavage. Animals from groups C and O received only saline solution for 28 days. The design used was totally randomized in 2 × 2 factorial scheme. Data were submitted to analysis of variance (anova). Animals from OB group showed inferior levels (p < 0.05) of total cholesterol (13.33%), triacylglycerols (16.77%) and blood glucose (23.97%) when compared to the animals from group O. The use of BG has provided smaller increase in Lee index (p < 0.05), without promoting alteration in feed and water consumption, organs weight, HDL-C, LDL+VLDL-C, carcass composition, villus/crypt ratio, and pancreas, kidney and stomach histology. BG from S. cerevisiae promoted beneficial metabolic effects in rats receiving high-fat diet.

Study of IRF6 and 8q24 region in non-syndromic oral clefts in the Brazilian population.

OBJECTIVES: We investigated the association between non-syndromic oral cleft and variants in IRF6 (rs2235371 and rs642961) and 8q24 region (rs987525) according to the ancestry contribution of the Brazilian population. SUBJECTS AND METHODS: Subjects with oral cleft (CL, CLP, or CP) and their parents were selected from different geographic regions of Brazil. Polymorphisms were genotyped using a TaqMan assay and genomic ancestry was estimated using a panel of 48 INDEL polymorphisms. RESULTS: A total of 259 probands were analyzed. A TDT detected overtransmission of the rs2235371 G allele (P = 0.0008) in the total sample. A significant association of this allele was also observed in CLP (P = 0.0343) and CLP + CL (P = 0.0027). IRF6 haplotype analysis showed that the G/A haplotype increased the risk for cleft in children (single dose: P = 0.0038, double dose: P = 0.0022) and in mothers (single dose: P = 0.0016). The rs987525 (8q24) also exhibited an association between the A allele and the CLP + CL group (P = 0.0462). These results were confirmed in the probands with European ancestry. CONCLUSIONS: The 8q24 region plays a role in CL/P and the IRF6 G/A haplotype (rs2235371/rs642961) increases the risk for oral cleft in the Brazilian population.

Analysis of descriptive electrophysiological parameters in contralateral interlimb reflexes on tetraplegic patients.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: The present study aims to analyze and correlate the interlimb reflexes (ILRs), through a standard methodology, in tetraplegic and healthy subjects. The study of the connectivity between the injured spinal cord and the ILR transmission empowers new rehabilitation pathways for tetraplegic patients. SETTING: University Hospital-UNICAMP, Campinas, Brazil. METHODS: A total of 15 chronic tetraplegic patients and 10 healthy subjects were analyzed with the same methodology. Two tests were performed: (i) In test 1, the stimulus was applied to the right-arm radial nerve and the electromyography (EMG) signal collected in contralateral left tibial muscle. (ii) In test 2, the stimulus was applied to the left-leg fibular nerve and EMG collected in contralateral limb biceps, exploring the opposite direction of the pathway. In both tests, the subjects were stimulated with intensities from 5 to 30 mA (5 mA step) and 40 × 500 µs current modulated pulses. Reflexes were detected from the averaging of the 40 EMG sweeps. RESULTS: Each group was analyzed with regard to the reflexes' incidence, amplitude and latency. ILRs were found with similar prominence in both groups. A correlation between the ILR amplitude and the subject injury level was verified. Significant differences were found in the correlation of ILR latency with stimulation charge between healthy and tetraplegic subjects. CONCLUSION: The ILR transmission parameters of healthy and tetraplegic subjects were studied. The results obtained strongly suggest a different ILR transmission between healthy and tetraplegic subjects, reinforcing the hypothesis of nerve regeneration after injury.

First Report of a 16SrIII-L Phytoplasma Associated with Frogskin Disease in Cassava (Manihot esculenta Crantz) in Brazil.

Cassava (Manihot esculenta Crantz) is a major staple crop in developing countries and a large source of raw material for industrial purposes as flour, starch, and ethanol. In July 2012, 24 cassava genotypes (corresponding to 1.85% of the accessions) with typical symptoms of frogskin disease (CFSD) were observed in one of the maintenance areas of the Brazilian Cassava Germplasm (located at Embrapa Cassava & Fruits, Cruz das Almas, Bahia State, Brazil). All diseased plants were asymptomatic on the aboveground parts (leaves and stem). However, for accessions BGM 880, BGM 1094, BGM 1100, BGM 1212, BGM 1218, and BGM 1526, all roots showed a woody appearance, thickened cork-like peel with opaque aspect, and coalescent lip-like slits in a honeycomb pattern. Based on literature description, two pathogens could be associated with CFSD: a dsRNA virus (belonging to family Reoviridae) and a 16SrIII-L phytoplasma (1). To investigate the presence of phytoplasma associated with the CFSD symptoms, total DNA was extracted from 0.5 g of root tissue collected from both symptomatic and asymptomatic roots by scratching the secondary vessel at the center of the cassava root with a CTAB method. The nested PCR was carried out using phytoplasma-specific primer set P1/Tint followed by R16F2n/R16R2, targeting the 16S rRNA gene sequence of 1.2 kb in length, for the final reaction (4). No phytoplasma was detected in asymptomatic cassava roots that were sampled from the same field. A posterior extraction of total RNA was made but no dsRNA was noticed on the agarose gel, and reaction of RT-PCR with specific primers (2) had no amplification. In order to characterize the strains, the 1.2-kb amplicon was digested with BamHI, MseI, MspI, KpnI, and TaqI endonucleases. The resulting patterns indicated that the symptomatic accessions were infected with a phytoplasma belonging to the 16SrIII group, sharing similarities with pseudo gel mapping from the reference strain of Peach X-Disease Phytoplasma (GenBank Accession No. L33733). Nested PCR products from accessions BGM 1526 and BGM 1212 were purified and sequenced by Macrogen, (Seoul, South Korea) in both directions, manually edited, and the consensus sequences were deposited in the NCBI database (GenBank Accession Nos. KF019184 and KF019185). Phylogenetic studies were conducted based on maximum parsimony, neighbor-joining, and maximum likelihood analysis for 16S rRNA. The phytoplasma 16S rRNA gene sequences from both strains had 99% identity (P < 0.0001) with the 16SrIII-L CFSD phytoplasma (EU346761 and AY737647), described by Alvarez et al. (1) infecting cassava in Colombia. To our knowledge, this is the first report of a phytoplasma associated with Cassava Frogskin Disease in Brazil, where only the dsRNA virus was recognized as causing this symptom (3). This is not likely to be an isolated case, and possibly more cassava plants are infected with this phytoplasma in Brazil. Due to the difficulties to observe the symptoms at the field level, this could be an emerging disease in that country. References: (1) E. Alvarez et al. Plant. Dis. 93:1139, 2009. (2) L. A. Calvert et al. J. Phytopathol. 156:647, 2008. (3) L. S. Poltroniere et al. Comun. Tec., Belem-PA. 006:2p, 1999. (4) C. D. Smart et al. Appl. Environ. Microb. 62:2988, 1996.

Adjuvant-induced arthritis promotes vascular hyporesponsiveness to phenylephrine through a nitric oxide-related mechanism.

Arthritis has important cardiovascular repercussions. Phenylephrine-induced vasoconstriction is impaired in rat aortas in the early phase of the adjuvant-induced arthritis (AIA), around the 15th day post-induction. Therefore, the present study aimed to verify the effects of AIA on hyporesponsiveness to phenylephrine in rat aortas. AIA was induced by intradermal injection of Mycobacterium tuberculosis (3.8 mg/dL) in the right hind paw of male Wistar rats (n=27). Functional experiments in isolated aortas were carried out 15 days after AIA induction. Morphometric and stereological analyses of the aortas were also performed 36 days after the induction of AIA. AIA did not promote structural modifications in the aortas at any of the time points studied. AIA reduced phenylephrine-induced contraction in endothelium-intact aortas, but not in endothelium-denuded aortas. However, AIA did not change KCl-induced contraction in either endothelium-intact or denuded aortas. L-NAME (non-selective NOS inhibitor), 1400W (selective iNOS inhibitor), and ODQ (guanylyl cyclase inhibitor) reversed AIA-induced hyporesponsiveness to phenylephrine in intact aortas. 7-NI (selective nNOS inhibitor) increased the contraction induced by phenylephrine in aortas from AIA rats. In summary, the hyporesponsiveness to phenylephrine induced by AIA was endothelium-dependent and mediated by iNOS-derived NO through activation of the NO-guanylyl cyclase pathway.

Rho GTPase activating protein 21-mediated regulation of prostate cancer associated 3 gene in prostate cancer cell.

The overexpression of the prostate cancer antigen 3 (PCA3) gene is well-defined as a marker for prostate cancer (PCa) diagnosis. Although widely used in clinical research, PCA3 molecular mechanisms remain unknown. Herein we used phage display technology to identify putative molecules that bind to the promoter region of PCA3 gene and regulate its expression. The most frequent peptide PCA3p1 (80%) was similar to the Rho GTPase activating protein 21 (ARHGAP21) and its binding affinity was confirmed using Phage Bead ELISA. We showed that ARHGAP21 silencing in LNCaP prostate cancer cells decreased PCA3 and androgen receptor (AR) transcriptional levels and increased prune homolog 2 (PRUNE2) coding gene expression, indicating effective involvement of ARHGAP21 in androgen-dependent tumor pathway. Chromatin immunoprecipitation assay confirmed the interaction between PCA3 promoter region and ARHGAP21. This is the first study that described the role of ARHGAP21 in regulating the PCA3 gene under the androgenic pathway, standing out as a new mechanism of gene regulatory control during prostatic oncogenesis.

Working conditions and common mental disorders in physicians in Brazil.

BACKGROUND: Common mental disorders (CMD) are a marker of work-related psychiatric morbidity. Previous studies have shown a high prevalence in Brazilian health care settings. AIMS: To assess the prevalence of CMD and their associated factors in a group of physicians working at a public health unit in Belo Horizonte, Brazil. METHODS: CMD were evaluated using the self-reporting questionnaire-20 (SQR-20), developed by the World Health Organization and validated for Brazil. The questionnaire consists of 20 questions: four about physical symptoms and 16 about emotional symptoms. Prevalence was calculated as a percentage of physicians with CMD. Poisson univariate and multivariate regression models were applied to assess associated factors. RESULTS: Analysis was based on 227 physicians who answered the SRQ-20 (97% response rate). The prevalence of CMD was 24%. Dissatisfaction and commitment to work remained positively associated with CMD. Having more than one job and significant social support from peers and superiors remained negatively associated with CMD. CONCLUSIONS: Prevalence of CMD is in a similar range to that reported in other countries and in Brazil generally. Aspects related to work were the only ones that were independently associated with CMD. Work-related aspects and the motivation of physicians are important and need to be taken into account to ensure that physicians remain healthy.

Participation of the Cytoskeletal and Lysosomal Compartments in Campylobacter jejuni Invasion of Caco-2 cells, the Cellular Response by Morphometric Analysis and the Presence of Cytokine and Chemokine Transcripts.

This study aimed to evaluate the participation of actin and tubulin in the process of internalisation, the interaction of bacterial phagosomes with lysosomes, the morphometric changes and the expression of inflammatory cytokines in Caco-2 cells infected with Campylobacter jejuni. Both actin and tubulin participated in the process of internalisation. Inside the cells, lysosomes fuse with phagosomes, which may lead to bacterial death because after 2 h, the bacteria were not detected by Transmission electron microscopy (TEM). There is increased expression of TGF-ß3 during the early stages, and IL-8 was expressed after 60 min p.i. This work showed that C. jejuni invades and causes major morphometric changes in epithelial cells. In response, the cells increase their expression of cytokines that can lead to inflammation. The mechanisms of invasion are dependent on actin and tubulin, and once internalised, lysosomes fuse with phagosomes.

Electroanalytical determination of the sunscreen agent octocrylene in cosmetic products.

An electroanalytical method was developed to detect and quantify the sunscreen agent octocrylene (OCR) in cosmetic products. The method was based on electrochemical reduction, using voltammetric techniques. OCR was reduced at -0.97 V vs. Ag/AgCl on a glassy carbon electrode using a mixture of Britton-Robinson buffer (0.04 mol L(-1)) and ethanol (7 : 3, v/v) as the supporting electrolyte solution. Under optimized conditions and square-wave voltammetry, OCR response was linear from 5.0 × 10(-6) to 8.0 × 10(-5) mol L(-1) (r = 0.9995), with a limit of detection of 2.8 × 10(-6) mol L(-1). The proposed electroanalytical method proved simple, fast and suitable for detection and quantification of OCR in samples of cosmetic products, with satisfactory results in the recovery test and analytical determination in real samples.

Oral health-related quality of life in children and adolescents with cerebral palsy: paired cross-sectional study.

OBJECTIVES: To evaluate the impact of oral health conditions on the Oral Health-Related Quality of Life (OHRQoL) in children and adolescents with Cerebral Palsy (CP) and compare with children and adolescents without CP. METHODS: This was a paired cross-sectional study, consisting of 121 children and adolescents with CP and 121 without CP, aged 6 to 14 years. Caregivers filled a socioeconomic-demographic and the Parental-Caregiver Perceptions Questionnaire (P-CPQ). Physical examination of the oral cavity assessed the dental caries experience, need for treatment, consequences of untreated dental caries, presence of dental trauma, bruxism and malocclusion. A descriptive analysis and Kruskal-Wallis and Mann-Whitney tests (p < 0.05) were performed. Variables with p values ≤ 0.20 in the bivariate analysis were included in the adjusted model analysis. Variables with a p value < 0.05 remained in the final Poisson Regression model. RESULTS: Caries experience had a negative impact on the quality of life of both groups, with and without CP. Presence of gastroesophageal reflux and difficulty to opening the mouth also had a negative impact on the OHRQoL of the group with CP. CONCLUSION: Children and adolescents with CP suffered a greater negative impact on OHRQoL than individuals without CP. Difficulty in opening the mouth and the presence of GER had a negative effect on the quality of life of individuals with CP, while dental caries had a negative impact on the OHRQoL of children and adolescents of both groups.

Assessing the environmental benefit of palladium-based single-atom heterogeneous catalysts for Sonogashira coupling.

The Pd-Cu catalysed Sonogashira coupling of terminal alkynes and aryl halides is a cornerstone synthetic strategy for C-C bond formation. Homogeneous organometallic systems conventionally applied are typically not reusable and require efficient downstream Pd removal steps for product purification, making it challenging to fully recover the precious metal. A holistic cradle-to-gate life cycle assessment (LCA) unveils that process footprint can be improved up to two orders of magnitude from repeated catalyst reuse. New classes of heterogeneous catalysts based on isolated metal atoms (single-atom catalysts, SACs) demonstrate promising potential to synergise the benefits of solid and molecular catalysts for efficient Pd utilisation. Here we show that using Pd atoms anchored on nitrogen-doped carbon permits full recovery of the metal and reuse of the catalyst over multiple cycles. A hybrid process using the Pd-SAC with a homogeneous CuI cocatalyst is more effective than a fully heterogeneous analogue based on a bimetallic Pd-Cu SAC, which deactivates severely due to copper leaching. In some scenarios, the LCA-based metrics demonstrate the footprint of the hybrid homogeneous-heterogeneous catalytic process is leaner than the purely homogeneous counterpart already upon single reuse. Combining LCA with experimental evaluation will be a useful guide to the implementation of solid, reusable catalysts for sustainable organic transformations.

Dual Effect of low-level laser therapy (LLLT) on the acute lung inflammation induced by intestinal ischemia and reperfusion: Action on anti- and pro-inflammatory cytokines.

BACKGROUND AND OBJECTIVE: It is unknown if pro- and anti-inflammatory mediators in acute lung inflammation induced by intestinal ischemia and reperfusion (i-I/R) can be modulated by low-level laser therapy (LLLT). STUDY DESIGN/MATERIAL AND METHODS: A controlled ex vivo study was developed in which rats were irradiated (660 nm, 30 mW, 0.08 cm² of spot size) on the skin over the right upper bronchus 1 hour post-mesenteric artery occlusion and euthanized 4 hours later. For pretreatment with anti-tumor necrosis factor (TNF) or IL-10 antibodies, the rats received either one of the agents 15 minutes before the beginning of reperfusion. METHODS: Lung edema was measured by the Evans blue extravasation and pulmonary neutrophils influx was determined by myeloperoxidase (MPO) activity. Both TNF and IL-10 expression and protein in lung were evaluated by RT-PCR and ELISA, respectively. RESULTS: LLLT reduced the edema (80.1 ± 41.8 µg g⁻¹ dry weight), neutrophils influx (0.83 ± 0.02 × 106 cells ml⁻¹), MPO activity (2.91 ± 0.60), and TNF (153.0 ± 21.0 pg mg⁻¹ tissue) in lung when compared with respective control groups. Surprisingly, the LLLT increased the IL-10 (0.65 ± 0.13) in lung from animals subjected to i-I/R. Moreover, LLLT (0.32 ± 0.07 pg ml⁻¹) reduced the TNF-α level in RPAECs when compared with i-I/R group. The presence of anti-TNF or IL-10 antibodies did not alter the LLLT effect on IL-10 (465.1 ± 21.0 pg mg⁻¹ tissue) or TNF (223.5 ± 21.0 pg mg⁻¹ tissue) in lung from animals submitted to i-I/R. CONCLUSION: The results indicate that the LLLT attenuates the i-I/R-induced acute lung inflammation which favor the IL-10 production and reduce TNF generation.

Exploring the association of predisposing factors of Cerebral Palsy and developmental defects of enamel: a case-control study.

AIM: To evaluate the occurrence of developmental defects of enamel (DDE) in children and adolescents with Cerebral Palsy (CP) and to analyze the effect of common factors in the etiology of CP on the occurrence of DDE. METHODS: A case-control study was carried out using the modified DDE index to classify enamel defects. The study group (SG) consisted of 45 participants with CP aged between three and 14 years. The control group (CG) consisted of 88 normotypical schoolchildren, paired by gender and age group. Caregivers answered a questionnaire on their socioeconomic status and medical history. The Chi-square tests, bivariate and multivariate analysis were performed (level significance < 0.05). RESULTS: The occurrence of DDE in SG and CG was 60% and 64.8%, respectively (p value = 0.726). The most frequent defect observed in SG was diffuse opacity (44.4%), followed by demarcated opacity (26.7%) and enamel hypoplasia (2.2%). No difference was observed in the defect's distribution among both groups (p value = 0.083). For SG, the bivariate analysis revealed a statically significant association between the presence of DDE and age group 7-14 years old and maternal schooling below 11 years. After adjusting for confounding variables, age, family income and maternal schooling were not associated with DDE. CONCLUSION: In conclusion, the occurrence of DDE was high and similar in both groups. The pre, peri or post-natal factors associated with CP were not significant for the presence of DDE.

Common mental disorders in late pregnancy in women who wanted or attempted an abortion.

BACKGROUND: In countries where legal abortion is restricted, many unwanted pregnancies are carried to term. Attempting an unsuccessful abortion may influence women's mental health. This study investigated the common mental disorders (CMDs) of depression and anxiety in the third trimester of pregnancy in women who wanted or had attempted an abortion in a poor region of Brazil. METHOD: CMDs were assessed by using the 20-item Self-Reporting Questionnaire (SRQ-20) in all pregnant women aged 18-49 years who were registered with publicly funded primary health care in Recife, Northeast Brazil. RESULTS: The study achieved a high response rate and 1121 (98.9%) women completed the interview. The prevalence of CMDs for the sample was 43.1% [95% confidence interval (CI) 40.2-46.1], and 63.6% (95% CI 55.4-71.2) among the 13.7% of women who attempted an abortion. The association between CMDs and attempted an abortion [odds ratio (OR) 2.05, 95% CI 1.3-3.1] remained after adjustment for confounders. CONCLUSIONS: This study found that attempting an abortion in the current pregnancy was associated with CMDs. Good access to family planning programs, including access to contraceptive methods and safe abortion, should help to improve the mental health of women.

Sequence analysis of 37 candidate genes for male infertility: challenges in variant assessment and validating genes.

BACKGROUND: The routine genetic analysis for diagnosing male infertility has not changed over the last twenty years, and currently available tests can only determine the etiology of 4% of unselected infertile patients. Thus, to create new diagnostic assays, we must better understand the molecular and genetic mechanisms of male infertility. Although next-generation sequencing allows for simultaneous analysis of hundreds of genes and the discovery of novel candidates related to male infertility, so far only a few gene candidates have enough sound evidence to support the gene-disease relationship. OBJECTIVE: Since complementary studies are required to validate genes, we aimed to analyze the presence of potentially pathogenic rare variants in a set of candidate genes related to azoospermia in a hitherto understudied South American population. SUBJECTS AND METHODS: We performed whole exome sequencing in a group of 16 patients with non-obstructive azoospermia from Ribeirão Preto, Brazil. Based on a recent systematic review of monogenic causes of male infertility, we selected a set of 37 genes related to azoospermia, Sertoli-Cell-Only histology, and spermatogenic arrest to analyze. The identified variants were confirmed by Sanger sequencing, and their functional consequence was predicted by in silico programs. RESULTS: We identified potential pathogenic variants in seven genes in six patients. Two variants, c.671A>G (p.(Asn224Ser)) in DMRT1 and c.91C>T (p.(Arg31Cys)) in REC8, have already been described in association with azoospermia. We also found new variants in genes that already have moderate evidence of being linked to spermatogenic failure (TEX15, KLHL10), in genes with limited evidence (DNMT3B, TEX14) and in one novel promising candidate gene that has no evidence so far (SYCE1L). DISCUSSION: Although this study included a small number of patients, the process of rationally selecting genes allowed us to detect rare potentially pathogenic variants, providing supporting evidence for validating candidate genes associated with azoospermia.

Spatiotemporal Dynamics and Natural Mortality Factors of Myzus persicae (Sulzer) (Hemiptera: Aphididae) in Bell Pepper Crops.

Pest populations are mostly regulated by climate, intra- and interspecific competition, natural enemies, and host plant quality. Myzus persicae (Sulzer) (Hemiptera: Aphididae) is a widely adapted aphid in the agroecosystems and is one of the main bell pepper pests. In the present study, we determined the spatial and temporal dynamics and the regulatory factors of M. persicae populations in bell pepper crops. The number of aphids and their natural enemies were evaluated during 2 years in four commercial bell pepper fields. Myzus persicae density data were related to temperature, rainfall, and natural enemies by multiple regression analysis and were then submitted to geostatistical analysis. The density of M. persicae was higher during the plant's reproductive growth stage. Rainfall, Chrysoperla spp., and Toxomerus spp. regulate M. persicae populations. Initial infestations of this pest occur along the edges of the fields and subsequently spread towards the center. This information is useful for integrated management programs aimed at anticipating periods of higher abundance of M. persicae and identifying arthropods to be prioritized in biological control.

Adjuvant-induced arthritis promotes vascular hyporesponsiveness to phenylephrine through a nitric oxide-related mechanism

Arthritis has important cardiovascular repercussions. Phenylephrine-induced vasoconstriction is impaired in rat aortas in the early phase of the adjuvant-induced arthritis (AIA), around the 15th day post-induction. Therefore, the present study aimed to verify the effects of AIA on hyporesponsiveness to phenylephrine in rat aortas. AIA was induced by intradermal injection of Mycobacterium tuberculosis (3.8 mg/dL) in the right hind paw of male Wistar rats (n=27). Functional experiments in isolated aortas were carried out 15 days after AIA induction. Morphometric and stereological analyses of the aortas were also performed 36 days after the induction of AIA. AIA did not promote structural modifications in the aortas at any of the time points studied. AIA reduced phenylephrine-induced contraction in endothelium-intact aortas, but not in endothelium-denuded aortas. However, AIA did not change KCl-induced contraction in either endothelium-intact or denuded aortas. L-NAME (non-selective NOS inhibitor), 1400W (selective iNOS inhibitor), and ODQ (guanylyl cyclase inhibitor) reversed AIA-induced hyporesponsiveness to phenylephrine in intact aortas. 7-NI (selective nNOS inhibitor) increased the contraction induced by phenylephrine in aortas from AIA rats. In summary, the hyporesponsiveness to phenylephrine induced by AIA was endothelium-dependent and mediated by iNOS-derived NO through activation of the NO-guanylyl cyclase pathway.