Exon-independent recruitment of SRSF1 is mediated by U1 snRNP stem-loop 3.

SRSF1 protein and U1 snRNPs are closely connected splicing factors. They both stimulate exon inclusion, SRSF1 by binding to exonic splicing enhancer sequences (ESEs) and U1 snRNPs by binding to the downstream 5' splice site (SS), and both factors affect 5' SS selection. The binding of U1 snRNPs initiates spliceosome assembly, but SR proteins such as SRSF1 can in some cases substitute for it. The mechanistic basis of this relationship is poorly understood. We show here by single-molecule methods that a single molecule of SRSF1 can be recruited by a U1 snRNP. This reaction is independent of exon sequences and separate from the U1-independent process of binding to an ESE. Structural analysis and cross-linking data show that SRSF1 contacts U1 snRNA stem-loop 3, which is required for splicing. We suggest that the recruitment of SRSF1 to a U1 snRNP at a 5'SS is the basis for exon definition by U1 snRNP and might be one of the principal functions of U1 snRNPs in the core reactions of splicing in mammals.

Prevention of heartworm infection in dogs using a combination of moxidectin, imidacloprid and praziquantel: evidence from a randomized clinical trial.

The aim of this study was to evaluate the efficacy of a topical combination of moxidectin 3.5%, imidacloprid 10% and praziquantel 10% for the prevention of Dirofilaria immitis (Leidy, 1856) infection in dogs. For this purpose, a randomized and controlled clinical trial was conducted between August 2021 and October 2022, in the municipality of Goiana, state of Pernambuco, north-eastern Brazil, where heartworm is highly prevalent. Of the 213 dogs initially sampled (baseline), 68 (31.9%) were positive for adult antigens (SNAP 4Dx Plus, Idexx) and/or microfilariae (modified Knott's test). On day 0, 140 negative dogs were randomly included in the treatment and control groups, 70 animals each. During the study, 60 dogs (34 treated and 26 untreated) were removed for different reasons. At the end of the study (day 360 ± 2), 36 treated and 44 untreated were sampled and included in the efficacy calculation. The efficacy against the development of adults and microfilariae was 84.7%, with only one treated dog being positive for adult antigens but negative for microfilariae. On the other hand, eight untreated dogs were positive for adult antigens and/or microfilariae, resulting in a significant difference in the number of positives between groups (Chi-square test = 4.706, df = 1, P = 0.0301). Remarkably, the efficacy against the appearance of D. immitis microfilariae was 100% (i.e., all treated dogs negative) and three untreated dogs were positive for microfilariae. The topical combination of moxidectin 3.5%, imidacloprid 10% and praziquantel 10% significantly reduced the risk of D. immitis infection in treated dogs as compared with untreated dogs, in a highly endemic area in north-eastern Brazil.

Expanding Lipidomic Coverage in Multisegment Injection-Nonaqueous Capillary Electrophoresis-Mass Spectrometry via a Convenient and Quantitative Methylation Strategy.

Orthogonal separation techniques coupled to high-resolution mass spectrometry are required for characterizing the human lipidome, given its inherent chemical and structural complexity. However, electrophoretic separations remain largely unrecognized in contemporary lipidomics research compared to established chromatographic and ion mobility methods. Herein, we introduce a novel derivatization protocol based on 3-methyl-1-p-tolyltriazene (MTT) as a safer alternative to diazomethane for quantitative phospholipid (PL) methylation (∼90%), which enables their rapid analysis by multisegment injection-nonaqueous capillary electrophoresis-mass spectrometry (MSI-NACE-MS). Isobaric interferences and ion suppression effects were minimized by performing an initial reaction using 9-fluorenylmethyoxycarbonyl chloride prior to MTT and a subsequent back extraction in hexane. This charge-switch derivatization strategy expands lipidome coverage when using MSI-NACE-MS under positive ion mode with improved resolution, greater sensitivity, and higher throughput (∼3.5 min/sample), notably for zwitterionic PLs that are analyzed as their cationic phosphate methyl esters. Our method was validated by analyzing methyl-tert-butyl ether extracts of reference human plasma, which enabled a direct comparison of 48 phosphatidylcholine and 27 sphingomyelin species previously reported in an interlaboratory lipidomics harmonization study. The potential for plasma PL quantification by MSI-NACE-MS via a serial dilution of NIST SRM-1950 was also demonstrated based on estimation of relative response factors using their reported consensus concentrations. Moreover, lipid identification was supported by modeling predictable changes in the electrophoretic mobility for cationic PLs in conjunction with MS/MS. Overall, this work offers a practical derivatization protocol to expand lipidome coverage in CE-MS beyond the analysis of hydrophilic/polar metabolites under aqueous buffer conditions.

Impact of dental restorations and removable prostheses on potentially malignant oral mucosal disorders in the general population.

STATEMENT OF PROBLEM: Dental restorations and removable dental prostheses have been considered as risk factors for potentially malignant disorders of the oral mucosa. It remains unclear whether amalgam, composite resins, and prosthesis materials can induce potentially malignant disorders. PURPOSE: The purpose of this clinical study was to determine the relationship between the presence of amalgam and composite resin restorations, crowns and fixed partial dentures, and removable prostheses in potentially malignant disorders. MATERIAL AND METHODS: The data of 6041 participants in the population-based Studies of Health in Pomerania (SHIP) were accessed. Potentially malignant disorders had been clinically diagnosed by calibrated dentists and documented with photographs. Dental treatment was subdivided into restored and replaced teeth. Dental restorations were subclassified as buccal composite resin or amalgam restorations. Prosthetic treatment was subclassified into removable partial or complete prostheses and definitive restorations with crowns and fixed partial dentures. RESULTS: In the maxilla, participants with removable prostheses had a higher incidence of potentially malignant disorders than participants not undergoing treatment with removable prostheses (OR 2.12; 95% CI: 1.08-4.18), but not in the mandible (OR 1.30; 95% CI: 0.67-2.53). The surfaces with composite resin restorations were associated with a slightly higher risk of mucosal lesions than those without the restorations (OR 1.04; 95% CI: 1.01-1.07). No significant association was found between amalgam restorations and mucosal lesions. CONCLUSIONS: Participants with removable prostheses have a higher risk of potentially malignant disorders. Composite resin restorations are associated with a higher risk of mucosal lesions, whereas no significant association was found between amalgam restorations and mucosal lesions.

Ticks on reptiles and amphibians in Central Amazonia, with notes on rickettsial infections.

Reptiles and amphibians are exceptional hosts for different ectoparasites, including mites and ticks. In this study, we investigated tick infestations on reptiles and amphibians trapped in Central Amazonia, and also assessed the presence of rickettsial infections in the collected ticks. From September 2016 to September 2019, 385 reptiles (350 lizards, 20 snakes, 12 tortoises, and three caimans) and 120 amphibians (119 anurans and one caecilian) were captured and examined for ectoparasites. Overall, 35 (10%) lizards, three (25%) tortoises and one (0.8%) toad were parasitized by ticks (124 larvae, 32 nymphs, and 22 adults). In lizards, tick infestation varied significantly according to landscape category and age group. Based on combined morphological and molecular analyses, these ticks were identified as Amblyomma humerale (14 larvae, 12 nymphs, 19 males, and one female), Amblyomma nodosum (three larvae, one nymph, and one female), and Amblyomma rotundatum (four larvae, three nymphs, and one female), and Amblyomma spp. (103 larvae and 16 nymphs). Our study presents the first records of A. nodosum in the Amazonas state and suggests that teiid lizards are important hosts for larvae and nymphs of A. humerale in Central Amazonia. Moreover, a nymph of A. humerale collected from a common tegu (Tupinambis teguixin) was found positive for Rickettsia amblyommatis, which agrees with previous reports, suggesting that the A. humerale-R. amblyommatis relationship may be more common than currently recognized.

Predicting Infarct Core From Computed Tomography Perfusion in Acute Ischemia With Machine Learning: Lessons From the ISLES Challenge.

BACKGROUND AND PURPOSE: The ISLES challenge (Ischemic Stroke Lesion Segmentation) enables globally diverse teams to compete to develop advanced tools for stroke lesion analysis with machine learning. Detection of irreversibly damaged tissue on computed tomography perfusion (CTP) is often necessary to determine eligibility for late-time-window thrombectomy. Therefore, the aim of ISLES-2018 was to segment infarcted tissue on CTP based on diffusion-weighted imaging as a reference standard. METHODS: The data, from 4 centers, consisted of 103 cases of acute anterior circulation large artery occlusion stroke who underwent diffusion-weighted imaging rapidly after CTP. Diffusion-weighted imaging lesion segmentation was performed manually and acted as a reference standard. The data were separated into 63 cases for training and 40 for testing, upon which quality metrics (dice score coefficient, Hausdorff distance, absolute lesion volume difference, etc) were computed to rank methods based on their overall performance. RESULTS: Twenty-four different teams participated in the challenge. Median time to CTP was 185 minutes (interquartile range, 180-238), the time between CTP and magnetic resonance imaging was 36 minutes (interquartile range, 25-79), and the median infarct lesion size was 15.2 mL (interquartile range, 5.7-45). The best performance for Dice score coefficient and absolute volume difference were 0.51 and 10.1 mL, respectively, from different teams. Based on the ranking criteria, the top team's algorithm demonstrated for average Dice score coefficient and average absolute volume difference 0.51 and 10.2 mL, respectively, outperforming the conventional threshold-based method (dice score coefficient, 0.3; volume difference, 15.3). Diverse algorithms were used, almost all based on deep learning, with top-ranked approaches making use of the raw perfusion data as well as methods to synthetically generate complementary information to boost prediction performance. CONCLUSIONS: Machine learning methods may predict infarcted tissue from CTP with improved accuracy compared with threshold-based methods used in clinical routine. This dataset will remain public and can be used to test improvement in algorithms over time.

Effects of cold physical plasma on oral lichen planus: An in vitro study (Effects of CAP on OLP).

OBJECTIVES: In the search for more effective and safe treatment avenues, we investigated cold physical plasma as a new treatment modality for therapy of oral lichen planus (OLP). MATERIAL AND METHODS: Healthy and diseased human mucosal tissue samples with a size of 3 mm in diameter obtained from OLP patients were subjected to plasma treatment ex vivo or were left untreated. Tissue sections were quantified for immune-infiltration of CD4+ , CD8+ , CD45RA+ , and CD45R0+ T cells. Moreover, the tissues' inflammatory profile was assessed by analyzing 12 different cytokines in the surrounding media. RESULTS: A significantly increased infiltrate of CD8+ and CD45-R0+ T cells was detected in OLP tissue samples when compared to healthy tissue. A higher concentration of interleukin (IL) 1ß, IL6, IL8, and granulocyte macrophage-colony stimulating factor (GM-CMF) was detected in OLP samples compared to healthy mucosal tissue. For all cytokines and chemokines investigated, 23 out of 24 comparisons showed a decrease in tendency (significant for IL1ß, IL2, IL10, and GM-CSF) in response to plasma treatment. In ex vivo-treated tissue, a decrease of T-cell infiltrate in OLP lesions compared with healthy tissue was observed. CONCLUSION: Our findings suggest cold physical plasma can be a promising therapeutic option for OLP that requires further validation in vivo.

Molecular epidemiology and prevalence of babesial infections in dogs in two hyperendemic foci in Brazil.

Babesial parasites are some of the most ubiquitous blood pathogens and consequently have considerable worldwide veterinary impact. Dogs living in the tropics are highly exposed to babesial parasites, particularly to Babesia vogeli. Limited data on the seroprevalence and molecular prevalence of Babesia spp. in dogs are available in Latin America. We conducted a cross-sectional study combining serological and molecular tests to estimate the seroprevalence and molecular epidemiology of Babesia spp. infections in dogs in two hyperendemic foci in Brazil. A total of 630 privately owned dogs (417 from Goiana municipality, Pernambuco state, north-eastern Brazil, and 213 from São Joaquim de Bicas municipality, Minas Gerais state, south-eastern Brazil) were sampled and molecularly and serologically tested for Babesia spp. Overall, 519 dogs (82.4%) presented detectable IgG antibodies against Babesia spp., and seropositivity was significantly higher in dogs older than 1 year. Molecularly, 34 dogs (5.4%) were positive for a ~ 200 bp fragment of the 18S rRNA gene of Babesia spp. and 88 (14.0%) for a longer fragment (~ 450 bp) of the same gene of Babesia spp. and other protozoa. The 18S rRNA gene sequences generated herein corresponded to B. vogeli (n = 52) or Hepatozoon canis (n = 20). This study confirms a high level of exposure to B. vogeli in two areas of Brazil and highlights that most of the dogs living in these areas are infected during the course of their life, reflected by increased seroprevalence in older dogs. Increased awareness and prevention of tick-borne protozoa infections in dogs from Brazil and Latin America are urgently needed.

Occipital Nerve Stimulation for Refractory Chronic Cluster Headache: A Cost-Effectiveness Study.

INTRODUCTION: Occipital nerve stimulation (ONS) is proposed to treat refractory chronic cluster headache (rCCH), but its cost-effectiveness has not been evaluated, limiting its diffusion and reimbursement. MATERIALS AND METHODS: We performed a before-and-after economic study, from data collected prospectively in a nation-wide registry. We compared the cost-effectiveness of ONS associated with conventional treatment (intervention and postintervention period) to conventional treatment alone (preintervention period) in the same patients. The analysis was conducted on 76 rCCH patients from the French healthcare perspective at three months, then one year by extrapolation. Because of the impact of the disease on patient activity, indirect cost, such as sick leave and disability leave, was assessed second. RESULTS: The average total cost for three months was €7602 higher for the ONS strategy compared to conventional strategy with a gain of 0.07 quality-adjusted life-years (QALY), the incremental cost-effectiveness ratio (ICER) was then €109,676/QALY gained. The average extrapolated total cost for one year was €1344 lower for the ONS strategy (p = 0.5444) with a gain of 0.28 QALY (p < 0.0001), the ICER was then €-4846/QALY gained. The scatter plot of the probabilistic bootstrapping had 80% of the replications in the bottom right-hand quadrant, indicating that the ONS strategy is dominant. The average indirect cost for three months was €377 lower for the ONS strategy (p = 0.1261). DISCUSSION: This ONS cost-effectiveness study highlighted the limitations of a short-time horizon in an economic study that may lead the healthcare authorities to reject an innovative strategy, which is actually cost-effective. One-year extrapolation was the proposed solution to obtain results on which healthcare authorities can base their decisions. CONCLUSION: Considering the burden of rCCH and the efficacy and safety of ONS, the demonstration that ONS is dominant should help its diffusion, validation, and reimbursement by health authorities in this severely disabled population.

Tick infestation on birds in an urban Atlantic Forest fragment in north-eastern Brazil.

Birds are important hosts for various tick species, playing a significant role in their biological life cycle and dispersion. In this study, we investigated tick infestations on birds trapped in an urban remnant of Atlantic Forest in Pernambuco state, Brazil. From February 2015 to March 2017, 541 birds belonging to 52 species were trapped with mist nets and examined for ectoparasites. Birds trapped in the late successional forest were significantly more infested than birds trapped in the early successional forest. In the same way, ectoparasite infestation varied significantly according to bird weight and collection plot. Overall, 198 birds (36.6%) belonging to 27 species were parasitized by ectoparasites (i.e., ticks, lice and/or mites). Ectoparasites were effectively collected from 111 birds, of which 99 belonging to 20 species were infested by ticks (n = 261), namely, Amblyomma longirostre (13 nymphs), Amblyomma nodosum (21 nymphs), Amblyomma varium (one nymph), and Amblyomma spp. (five nymphs and 221 larvae). Most of the ticks (> 90%) were collected from Passeriformes. This study provides the second record of A. varium in Pernambuco state and confirms that birds, especially Passeriformes, are important hosts for larvae and nymphs of Amblyomma spp. in the Atlantic Forest biome of Pernambuco.

Phase 3 randomized, placebo-controlled study of galcanezumab in patients with chronic cluster headache: Results from 3-month double-blind treatment.

OBJECTIVE: To report efficacy and safety of galcanezumab in adults with chronic cluster headache. BACKGROUND: Galcanezumab is a humanized monoclonal antibody that binds to calcitonin gene-related peptide and inhibits its biological activity. METHODS: This study comprised a prospective baseline period, a 12-week double-blind, placebo-controlled treatment period, and a 52-week open-label period. Up to six protocol-specified concomitant preventive medications were allowed if patients were on a stable dose for 2 months prior to the prospective baseline period. Patients were randomized 1:1 to monthly subcutaneous galcanezumab (300 mg) or placebo. The primary endpoint was overall mean change from baseline in weekly attack frequency with galcanezumab compared to placebo. Key secondary endpoints were ≥50% response rate and percentage of patients meeting sustained response. Results from the double-blind treatment period are reported. RESULTS: A total of 237 patients were randomized and treated (120 placebo; 117 galcanezumab). At baseline, the mean age was 45 years and 63% were using ≥1 preventive drug. The primary endpoint was not met; mean change in weekly attack frequency was -4.6 placebo versus -5.4 galcanezumab (p = 0.334). Key secondary endpoints also were not met. Injection site-related treatment-emergent adverse events were more common in the galcanezumab than the placebo group, with significantly more injection site erythema. CONCLUSION: Treatment with galcanezumab 300 mg did not achieve its primary and key secondary endpoints. This study underscores the potential distinct biology of cCH as well as the significant unmet need for safe, effective, and well-tolerated preventive treatment. The safety profile of galcanezumab in cCH is consistent with that observed in trials of episodic CH and migraine. TRIAL REGISTRATION: NCT02438826; https://www.clinicaltrials.gov/ct2/show/NCT02438826.

The mechanisms of a mammalian splicing enhancer.

Exonic splicing enhancer (ESE) sequences are bound by serine & arginine-rich (SR) proteins, which in turn enhance the recruitment of splicing factors. It was inferred from measurements of splicing around twenty years ago that Drosophila doublesex ESEs are bound stably by SR proteins, and that the bound proteins interact directly but with low probability with their targets. However, it has not been possible with conventional methods to demonstrate whether mammalian ESEs behave likewise. Using single molecule multi-colour colocalization methods to study SRSF1-dependent ESEs, we have found that that the proportion of RNA molecules bound by SRSF1 increases with the number of ESE repeats, but only a single molecule of SRSF1 is bound. We conclude that initial interactions between SRSF1 and an ESE are weak and transient, and that these limit the activity of a mammalian ESE. We tested whether the activation step involves the propagation of proteins along the RNA or direct interactions with 3' splice site components by inserting hexaethylene glycol or abasic RNA between the ESE and the target 3' splice site. These insertions did not block activation, and we conclude that the activation step involves direct interactions. These results support a model in which regulatory proteins bind transiently and in dynamic competition, with the result that each ESE in an exon contributes independently to the probability that an activator protein is bound and in close proximity to a splice site.

Third molars and periodontal damage of second molars in the general population.

AIM: The aim of this study was to clarify the association between impacted or erupted third molars and periodontal pathology, assessed by probing depth (PD) and clinical attachment levels (CAL), in adjacent second molars. MATERIALS AND METHODS: Data from the population-based Study of Health in Pomerania (SHIP) was used. This is the first project with whole-body magnetic resonance imaging (WB-MRI) application in a general population setting with dental issues. Calibrated and licensed dentists measured PD and CAL with a periodontal probe. RESULTS: In the mandible, individuals with erupted third molars had a 1.45-fold higher odds ratio (CI:1.03; 2.05; p = 0.031) and individuals with impacted third molars had a 2.37-fold higher odds ratio (CI:1.45; 3.85; p < 0.001) to have higher PD values in the adjacent distal site of second molar than individuals with missing third molars in the total population. These significant associations were even more pronounced in the population free of periodontitis disease. In participants with periodontitis in the maxilla, there was an association of erupted third molars with an increased PD of adjacent molars. CONCLUSION: In particular, in the mandible, those findings could guide dental practitioners more in the direction to remove the third molars after having evaluated the periodontium of the adjacent teeth.

Occipital nerve stimulation improves the quality of life in medically-intractable chronic cluster headache: Results of an observational prospective study.

Background Occipital nerve stimulation (ONS) has been proposed to treat chronic medically-intractable cluster headache (iCCH) in small series of cases without evaluation of its functional and emotional impacts. Methods We report the multidimensional outcome of a large observational study of iCCH patients, treated by ONS within a nationwide multidisciplinary network ( https://clinicaltrials.gov NCT01842763), with a one-year follow-up. Prospective evaluation was performed before surgery, then three and 12 months after. Results One year after ONS, the attack frequency per week was decreased >30% in 64% and >50% in 59% of the 44 patients. Mean (Standard Deviation) weekly attack frequency decreased from 21.5 (16.3) to 10.7 (13.8) ( p = 0.0002). About 70% of the patients responded to ONS, 47.8% being excellent responders. Prophylactic treatments could be decreased in 40% of patients. Functional (HIT-6 and MIDAS scales) and emotional (HAD scale) impacts were significantly improved, as well as the health-related quality of life (EQ-5D). The mean (SD) EQ-5D visual analogic scale score increased from 35.2 (23.6) to 51.9 (25.7) ( p = 0.0037). Surgical minor complications were observed in 33% of the patients. Conclusion ONS significantly reduced the attack frequency per week, as well as the functional and emotional headache impacts in iCCH patients, and dramatically improved the health-related quality of life of responders.

A combination of coenzyme Q10, feverfew and magnesium for migraine prophylaxis: a prospective observational study.

BACKGROUND: Feverfew (Tanacetum parthenium L.), magnesium and coenzyme Q10 are frequently used for migraine prophylaxis. Supplementation with a fixed combination of these three agents (Antemig®, PiLeJe) was investigated in an observational study. METHODS: Adult patients suffering from migraine according to the criteria of the International Headache Society were enrolled by general practitioners (≥2 migraine attacks during previous month; exclusion of chronic migraine and medication overuse) and after a one-month baseline phase, supplemented with one tablet of 100 mg feverfew, 100 mg coenzyme Q10 and 112.5 mg magnesium per day for 3 months. RESULTS: Supplementation significantly reduced the number of days with migraine headache during third month of supplementation compared to baseline phase (1.3 days ±1.5 versus 4.9 days ±2.6, p < 0.0001; n = 68 intention to treat; primary criterion). The decrease was progressive over the period of supplementation and significant from first month (1st month: -2.5 days ±3.1, p < 0.0001; 2nd month: -3 days ±2.8, p < 0.0001). The proportion of patients with a reduction of at least 50% in the number of days with migraine headache was 75% (51/68) after 3 months, with a progressive increase over the period of supplementation (63.2% [43/68] after 1 month and 70.6% [48/68] after 2 months). The proportion of patients with anxiety and depressive symptoms (Hospital Anxiety and Depression Scale) decreased between baseline phase and third month of supplementation from 61.9% (39/63 patients with information available) to 35% (21/60) for depression and from 52.4% (33/63) to 30% (18/60) for anxiety. An improvement of quality of life (Qualité de Vie et Migraine questionnaire) was also observed. The combination was well tolerated. CONCLUSIONS: Results suggest that the proprietary supplement containing feverfew, coenzyme Q10 and magnesium assessed could be beneficial and safe for the prevention of migraine in adult patients and merits further study. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02901756 , retrospectively registered on August 24, 2016.

Immediate versus delayed loading of strategic mini dental implants for the stabilization of partial removable dental prostheses: a patient cluster randomized, parallel-group 3-year trial.

BACKGROUND: Acceptable short-term survival rates (>90 %) of mini-implants (diameter < 3.0 mm) are only documented for mandibular overdentures. Sound data for mini-implants as strategic abutments for a better retention of partial removable dental prosthesis (PRDP) are not available. METHODS/DESIGN: The purpose of this study is to test the hypothesis that immediately loaded mini-implants show more bone loss and less success than strategic mini-implants with delayed loading. In this four-center (one university hospital, three dental practices in Germany), parallel-group, controlled clinical trial, which is cluster randomized on patient level, a total of 80 partially edentulous patients with unfavourable number and distribution of remaining abutment teeth in at least one jaw will receive supplementary min-implants to stabilize their PRDP. The mini-implant are either immediately loaded after implant placement (test group) or delayed after four months (control group). Follow-up of the patients will be performed for 36 months. The primary outcome is the radiographic bone level changes at implants. The secondary outcome is the implant success as a composite variable. Tertiary outcomes include clinical, subjective (quality of life, satisfaction, chewing ability) and dental or technical complications. DISCUSSION: Strategic implants under an existing PRDP are only documented for standard-diameter implants. Mini-implants could be a minimal invasive and low cost solution for this treatment modality. TRIAL REGISTRATION: The trial is registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00007589 ( www.germanctr.de ) on January 13(th), 2015.

Prevalence of Leishmania infection in 205 cats from a referral hospital population in Brazil (2021-2022).

Leishmaniases are a group of neglected diseases of significant public health concern, with Brazil being the primary focus of this disease in the Americas. The municipality of Sobral, in the state of Ceará, is a historical focus of visceral leishmaniasis in both humans and dogs, but data on Leishmania spp. infections in cats are limited. Between April 2021 and February 2022, 205 cats from a referral hospital population were sampled and tested for Leishmania spp. by real-time PCR. Eight cats (3.9%; 95% CI: 1.7-7.5%) tested positive. Among these, three (37.5%) displayed clinical signs compatible with feline leishmaniosis. Non-domiciled cats showed significantly higher positivity compared to domiciled ones (Fisher's exact test, P = 0.0124). Considering their potential role as reservoirs of L. infantum, it is crucial to conduct further studies to understand the Leishmania spp. circulating among cats in Sobral and to implement measures for reducing their exposure to phlebotomine sand fly vectors in this important focus of leishmaniases.

Seasonal dynamics of Amblyomma cajennense (Fabricius, 1787) sensu stricto in a degraded area of the Amazon biome, with notes on Rickettsia amblyommatis infection.

BACKGROUND: The tick Amblyomma cajennense sensu stricto (A. cajennense s.s.) frequently parasitizes animals and humans in the Amazon biome, in addition to being a vector of Rickettsia amblyommatis. In the present study, we evaluated both the population dynamics of A. cajennense s.s. in a degraded area of the Amazon biome and the presence of rickettsial organisms in this tick population. METHODS: The study was carried out in a rural area of the Santa Inês municipality (altitude: 24 m a.s.l.), Maranhão state, Brazil. Ticks were collected from the environment for 24 consecutive months, from June 2021 to May 2023. The region is characterized by two warm seasons: a rainy season (November-May) and a dry season (June-October). We characterized the temporal activity of A. cajennense s.s. on the vegetation by examining questing activity for each life stage (larvae, nymphs, adults [males and females]) in relation to the dry and rainy season. Ticks collected in this study were randomly selected and individually tested by a TaqMan real-time PCR assay that targeted a 147-bp fragment of the rickettsial gltA gene. RESULTS: Overall, 1843 (62.4%) adults (52.6% females, 47.4% males), 1110 (37.6%) nymphs and 398 larval clusters were collected. All adult females and nymphs were morphologically identified as A. cajennense s.s. Larval activity was observed from April to December, with a peak from June to September (dry season); nymph abundance peaked from September to November (transition period between dry and rainy seasons); and adult ticks were abundant from October to May (spring/summer/early autumn). The infection rate by R. amblyommatis in A. cajennense s.s. ticks was at least 7% (7/99). CONCLUSION: Our data suggest a 1-year generation pattern for A. cajennense s.s., with a well-defined seasonality of larvae, nymphs and adults in the Amazon biome. Larvae predominate during the dry season, nymphs are most abundant in the dry-rainy season transition and adults are most abundant in the rainy season. The presence of R. amblyommatis in adult ticks suggests that animals and humans in the study region are at risk of infection by this species belonging to the spotted fever group of Rickettsia.

Rickettsial Infection in Ticks from a National Park in the Cerrado Biome, Midwestern Brazil.

This study was carried out from February 2020 to September 2021 in Parque Nacional das Emas (PNE), a national park located in the Cerrado biome, midwestern Brazil, as well as in surrounding rural properties. Serum and tick samples were collected from dogs, terrestrial small mammals, and humans. Ticks were also collected from the environment. Dogs were infested with Rhipicephalus linnaei adults, whereas small mammals were infested by immature stages of Amblyomma spp., Amblyomma triste, Amblyomma dubitatum, and Amblyomma coelebs. Ticks collected from vegetation belonged to several species of the genus Amblyomma, including A. coelebs, A. dubitatum, Amblyomma naponense, Amblyomma sculptum, and A. triste. Two Rickettsia species were molecularly detected in ticks: Rickettsia parkeri in A. triste from the vegetation and a Rickettsia sp. (designated Rickettsia sp. strain PNE) in A. sculptum and A. triste collected from lowland tapirs (Tapirus terrestris). Based on short gltA gene fragments, this rickettsial organism showed 99.7-100% to Rickettsia tillamookensis. Seroreactivity to Rickettsia antigens was detected in 21.9% of dogs, 15.4% of small mammals, and 23.5% of humans. The present study reveals the richness of ticks and demonstrates the circulation of rickettsial agents in one of the largest conservation units in the Cerrado biome in Brazil. To our knowledge, this is the first report of a rickettsial phylogenetically related to R. tillamookensis in Brazil.

The cerebral representation of temporomandibular joint occlusion and its alternation by occlusal splints.

Occlusal splints are a common and effective therapy for temporomandibular joint disorder. Latest hypotheses on the impact of occlusal splints suggest an altered cerebral control on the occlusion movements after using a splint. However, the impact of using a splint during chewing on its cerebral representation is quite unknown. We used functional magnetic resonance imaging (fMRI) to investigate brain activities during occlusal function in centric occlusion on natural teeth or on occlusal splints in fifteen healthy subjects. Comparisons between conditions revealed an increased activation for the bilateral occlusion without a splint in bilateral primary and secondary sensorimotor areas, the putamen, inferior parietal and prefrontal cortex (left dorsal and bilateral orbital) and anterior insular. In contrast, using a splint increased activation in the bilateral prefrontal lobe (bilateral BA 10), bilateral temporo-parietal (BA 39), occipital and cerebellar hemispheres. An additionally applied individually based evaluation of representation sites in regions of interest demonstrated that the somatotopic representation for both conditions in the pre- and postcentral gyri did not significantly differ. Furthermore, this analysis confirmed the decreasing effect of the splint on bilateral primary and secondary motor and somatosensory cortical activation. In contrast to the decreasing effect on sensorimotor areas, an increased level of activity in the fronto-parieto-occipital and cerebellar network might be associated with the therapeutic effect of occlusal splints.