Unequal Impact of COL1A1 and COL1A2 Variants on Dentinogenesis Imperfecta.

Dentinogenesis imperfecta (DI) is the main orodental manifestation of osteogenesis imperfecta (OI) caused by COL1A1 or COL1A2 heterozygous pathogenic variants. Its prevalence varies according to the studied population. Here, we report the molecular analysis of 81 patients with OI followed at reference centers in Brazil and France presenting COL1A1 or COL1A2 variants. Patients were submitted to clinical and radiographic dental examinations to diagnose the presence of DI. In addition, a systematic literature search and a descriptive statistical analysis were performed to investigate OI/DI phenotype-genotype correlation in a worldwide sample. In our cohort, 50 patients had COL1A1 pathogenic variants, and 31 patients had COL1A2 variants. A total of 25 novel variants were identified. Overall, data from a total of 906 individuals with OI were assessed. Results show that DI was more frequent in severe and moderate OI cases. DI prevalence was also more often associated with COL1A2 (67.6%) than with COL1A1 variants (45.4%) because COL1A2 variants mainly lead to qualitative defects that predispose to DI more than quantitative defects. For the first time, 4 DI hotspots were identified. In addition, we showed that 1) glycine substitution by branched and charged amino acids in the α2(I) chain and 2) substitutions occurring in major ligand binding regions-MLRB2 in α1(I) and MLBR 3 in α2(I)-could significantly predict DI (P < 0.05). The accumulated variant data analysis in this study provides a further basis for increasing our comprehension to better predict the occurrence and severity of DI and appropriate OI patient management.

Electrostatic frequency reduction: A negative stiffness mechanism for measuring dissipation in a mechanical oscillator at low frequency.

Broadband seismometers and gravitational wave detectors make use of mechanical resonators with a high quality factor to reduce Brownian noise. At low frequency, Brownian noise is ultimately dominated by internal friction in the suspension, which has a 1/f noise compared with the white noise arising from viscous dissipation. Internal friction is typically modeled as a frequency-dependent loss and can be challenging to measure reliably through experiment. In this work, we present the physics and experimental implementation of electrostatic frequency reduction (EFR) in a mechanical oscillator-a method to measure dissipation as a function of frequency. By applying a high voltage to two parallel capacitor plates, with the center plate being a suspended mass, an electrostatic force is created that acts as a negative stiffness mechanism to reduce the system's resonance frequency. Through EFR, the loss angle can be measured as a function of frequency by measuring amplitude decay response curves for a range of applied voltages. We present experimental measurements of the loss angle for three metal helical extension springs in the nominal frequency range 0.7-2.9 Hz at 0.2 Hz intervals, demonstrating the possibility for fine adjustment of the resonance frequency for loss angle measurements. A quality factor proportional to the resonance frequency squared was measured, an indication that internal friction and other non-viscous dissipation elements, such as electrostatic damping, were the prominent loss mechanisms in our experiments. Finally, we consider the implications of Brownian noise arising from internal friction on a low 1/f noise seismometer.

Partial caries removal in deep caries lesions: a 5-year multicenter randomized controlled trial.

OBJECTIVE: This multicenter randomized controlled clinical trial aimed to compare the outcomes of stepwise excavation (SW) and partial caries removal (PCR) regarding the maintenance of pulp vitality in deep caries lesions over 5 years. METHODS: At baseline, 299 permanent molars with deep caries lesions were randomly assigned to control or test groups. The control group received the stepwise excavation treatment (SW), while the test group received partial caries removal from the pulpal wall followed by restoration in a single session (PCR). Treatments were conducted in two centers located in the cities of Porto Alegre (South Brazil) and Brasília (Midwest Brazil). Survival analysis was performed to compare PCR and SW over time (Weibull regression models). The primary outcome of this study was pulp vitality, determined by the combination of the following characteristics: positive response to cold test, negative response to percussion, absence of spontaneous pain, and absence of periapical lesion (radiographic examination). RESULTS: This 5-year study includes data pertaining to 229 teeth: 121 teeth actually examined at the 5-year appointment, and 108 teeth contributed with data collected in previous follow-ups (18 months or 3 years). Survival analysis showed success rates of 80% in PCR group and 56% in SW group (p < 0.001). Failure was significantly associated with treatment [PCR, HR=0.38; 95%CI=0.23-0.63)] and region [South, HR=2.22; 95%CI=1.21-4.08]. CONCLUSION: PCR significantly reduced the occurrence of pulp necrosis when compared with SW. CLINICAL RELEVANCE: This study supports the PCR as a single-visit technique to manage deep caries lesions in permanent teeth.

Experiments match simulations in a multiple post reentrant cavity.

Microwave reentrant cavities are used for many applications in science and engineering. The potential for both high mechanical tunability and high electric quality factors make them important tools in many areas. They are usually resonant cylindrical cavities with a central post, which makes a small gap spacing with the cavity wall. By adding an arbitrary number of extra posts, they are generalized to a type of multiple post reentrant cavity. This new approach has been theoretically studied but no experimental results have been presented. The main purpose of this work was to compare experimental modes with simulated ones from a reentrant cavity made of forty nine cylindrical posts. Each post could be moved using a screw in order to make tunable gap spacing between the post top and the cavity cover. Eight different gap setups were made making it possible to investigate thirty six different reentrant modes at room temperature. The lowest frequency percentage agreement between experiment and simulation was 91.31%, and the best one was 99.92%. Taking into account all the modes, 94.44% of them agreed above 96%. Thus, we have determined an experimental procedure suitable to investigate the reentrant modes from multiple post cavities. There is a wide range of potential applications for such cavities due to their unique features compared to conventional ones.

Timing and quality of sleep in a rural Brazilian family-based cohort, the Baependi Heart Study.

Sleep is modulated by several factors, including sex, age, and chronotype. It has been hypothesised that contemporary urban populations are under pressure towards shorter sleep duration and poorer sleep quality. Baependi is a small town in Brazil that provides a window of opportunity to study the influence of sleep patterns in a highly admixed rural population with a conservative lifestyle. We evaluated sleep characteristics, excessive daytime sleepiness, and chronotype using the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Morningness-Eveningness Questionnaire questionnaires, respectively. The sample consisted of 1,334 subjects from the Baependi Heart study (41.5% male; age: 46.5 ± 16.2 y, range: 18-89 years). Average self-reported sleep duration was 07:07 ± 01:31 (bedtime 22:32 ± 01:27, wake up time: 06:17 ± 01:25 hh:min), sleep quality score was 4.9 + 3.2, chronotype was 63.6 ± 10.8 and daytime sleepiness was 7.4 ± 4.8. Despite a shift towards morningness in the population, chronotype remained associated with reported actual sleep timing. Age and sex modulated the ontogeny of sleep and chronotype, increasing age was associated with earlier sleep time and shorter sleep duration. Women slept longer and later, and reported poorer sleep quality than men (p < 0.0001). This study provides indirect evidence in support of the hypothesis that sleep timing was earlier prior to full urbanisation.

Polymorphisms assessment in the promoter region of IL12RB2 in Amazon leprosy patients.

Leprosy displays a wide clinical spectrum that is dependent of the type of immune response. We investigate here whether polymorphisms in the promoter region of the IL12RB2 gene are associated with susceptibility or resistance to clinical forms of leprosy. Nucleotide sequencing of the promoter region of IL12RB2 encompassing SNPs -1035 A/G, -1033 T/C, -1023 A/G, -650 del/G and -464 A/G was performed on DNA samples from 105 leprosy patients and 108 healthy controls. However, none of the SNPs were associated with susceptibility to the disease or any of its clinical forms. Similarly, haplotype analysis did not show any association. The haplotype -1035A/-1033T/-650G/-464A was prevalent, and homozygosity for this haplotype was associated to a lower distribution of CD4(+) T cells (p=0.041). Our data suggest that polymorphisms present in the promoter region of IL12RB2 may not be associated with susceptibility to leprosy or its clinical forms.

One-year assessment of surgical outcomes in Class III patients using cone beam computed tomography.

The purpose of this study was to apply a novel method to evaluate surgical outcomes at 1 year after orthognathic surgery for Class III patients undergoing two different surgical protocols. Fifty patients divided equally into two groups (maxillary advancement only and combined with mandibular setback) had cone beam computed tomography (CBCT) scans taken pre-surgery, at splint removal, and at 1-year post-surgery. An automatic cranial base superimposition method was used to register, and shape correspondence was applied to assess, the overall changes between pre-surgery and splint removal (surgical changes) and between splint removal and 1-year post-surgery at the end of orthodontic treatment (post-surgical adaptations). Post-surgical maxillary adaptations were exactly the same for both groups, with 52% of the patients having changes >2mm. Approximately half of the post-surgical changes in the maxilla for both groups were vertical. The two-jaw group showed significantly greater surgical and post-surgical changes in the ramus, chin, and most of the condylar surfaces (P<0.05). Post-surgical adaptation on the anterior part of the chin was also more significant in the two-jaw group (P<0.05). Regardless of the type of surgery, marked post-surgical adaptations were observed in the regions evaluated, which explain the adequate maxillary-mandibular relationship at 1-year post-surgery on average, with individual variability.

Partial removal of carious dentine: a multicenter randomized controlled trial and 18-month follow-up results.

AIM: The aim of this study was to evaluate the effectiveness of partial removal of carious dentine and restoration in a single session (PDR) and stepwise excavation (SW), both of which are treatments for deep carious lesions, in Public Health Services in Brazil. INCLUSION CRITERIA: patients ≥6 years old, permanent molars with deep caries lesions (having a radiolucency halfway or more into dentine) and pulp vitality but absence of spontaneous pain, positive percussion test, and periapical alterations. The subjects received either PDR (test group) or SW (control group). The radiological and clinical exams were performed after a mean time of 18 months. OUTCOMES: success was defined as pulp sensitivity to cold test and absence of periapical alterations. RESULTS: Of the 299 treatments performed, 146 were SW and 153 were PDR; 122 were amalgam restorations and 168 resin-composite restorations. There were no differences between the groups regarding the baseline characteristics (i.e. age, gender and family income). After 18 months, 212 evaluations were performed, which indicated 99 and 86% success rates in the PDR and SW groups, respectively (p = 0.016). Reasons for failure were: PDR - 1 pulpitis; SW - 8 pulpitis; 1 osteitis; 4 necrosis; 1 endodontic treatment. None of the baseline variables were significantly associated with the outcomes. CONCLUSION: The retention of carious dentine does not interfere in pulp vitality. Data from this 18-month study suggest that the procedure of reopening the cavity to remove the residual infected dentine is not necessary.

Photobiostimulation on wound healing treatment by ClAlPc-nanoemulsion from a multiple-wavelength portable light source on a 3D-human stem cell dermal equivalent.

This research evaluated the effect of multiple-wave lasertherapy on the healing process of surgical wounds based on in vitro models denominated stem-dermal equivalents. These human skin models were obtained from a co-culture of dermal cells and bone marrow mesenchymal stem cells. The experimental tests were carried out using a LED portable to multiple waves (operating at 660 nm and 810 nm) at different doses to induce photobiostimulation (10 to 70 mJ.cm-2). Moreover, a photosensitizer drug was employed as a new advanced designed nanomaterial, being a nanoemulsion with biopolymers to obtain an efficient drug delivery system to release lipophilic compounds. The studies were performed considering the light combination application monitoring the kinetic contraction of the dermal equivalent model and the quantification of important macromolecules (as metaloproteases derivatives), related directly with wound healing process. Results showed that an appropriate photomodulation using the combination of both wavelengths (in the red and infrared range) is possible, such that it can contribute to wound healing therapy and/or other pathological skin disease treatment.

Randomized trial of partial vs. stepwise caries removal: 3-year follow-up.

This randomized, multicenter clinical trial evaluated the effectiveness of 2 treatments for deep caries lesions - partial caries removal (PCR) and stepwise excavation (SW) - with respect to the primary outcome of pulp vitality for a 3-year follow-up period. Inclusion criteria were as follows: patients with permanent molars presenting deep caries lesions (lesion affecting ≥ 1/2 of the dentin on radiographic examination), positive response to a cold test, absence of spontaneous pain, negative sensitivity to percussion, and absence of periapical lesions (radiographic examination). Teeth randomly assigned to PCR (test) received incomplete caries removal and filling in a single session. Outcome success was evaluated by assessment of pulp vitality, determined by pulp sensitivity to a cold test and the absence of periapical lesions. Data were analyzed by a Weibull regression model with shared frailty term (survival analysis). At baseline, 299 treatments were executed: PCR, 152 and SW, 147. By the end of the 3-year follow-up period, 213 teeth had been evaluated. Adjusted survival rates were 91% for PCR and 69% for SW (p = 0.004). These results suggest that there is no need to re-open a cavity and perform a second excavation for pulp vitality to be preserved (Clinical trials registration NCT00887952).

IFN-γ +875 microsatellite polymorphism as a potential protection marker for leprosy patients from Amazonas state, Brazil.

Polymorphisms present in the first intron of IFN-γ may have an important role in the regulation of the immune response, which could have functional consequences for gene transcription. Leprosy patients are characterized by different immune responses in different clinical forms. We investigated a possible association of the +874 polymorphism and CA repeats present in the first intron of IFN-γ with susceptibility to leprosy and with the manifestation of the different clinical forms. Nucleotide sequencing was performed with samples from 108 leprosy patients and 113 controls subjects, as well as immunophenotyping of CD(4)(+), CD(8)(+) and CD(69)(+) T cells by flow cytometry. The data showed that there were no significant differences between patients and control subjects, as well as according classification of Ridley-Jopling. However, the A/A genotype was significantly increased in paucibacillary patients (p=0.028) and the microsatellite encoding 16 CA repeats were significantly associated with paucibacillary compared to multibacillary patients (p=0.019). Individuals homozygous for the +874 A allele, the mean level of CD(4)(+) and CD(69)(+) T cells was higher. Our data suggest that polymorphisms present in the first intron of IFN-γ are not associated with susceptibility to leprosy, nevertheless, the +874 polymorphism and the CA repeats number encoded in IFN-γ gene may be related to a higher cellular immune response in patients and are consistently more frequently detected in PB patients.

Control of experimental pulmonary tuberculosis depends more on immunostimulatory leukotrienes than on the absence of immunosuppressive prostaglandins.

Prostaglandins (PGs) and leukotrienes (LTs) are produced in Mycobacterium tuberculosis (Mtb)-infected lungs and have immune suppressive and protective effects, respectively. Considering that both of these mediators are produced during mycobacterial infection, we investigated the specific and relative biological importance of each in regulating host response in experimental tuberculosis. Administration of celecoxib, which was found to reduce lung levels of PGE(2) and increase LTB(4), enhanced the 60-day survival of Mtb-infected mice in 14%. However administration of MK-886, which reduced levels of LTB(4) but did not enhance PGE(2), reduced 60-day survival from 86% to 43% in Mtb-infected mice, and increased lung bacterial burden. MK-886 plus celecoxib reduced survival to a lesser extent than MK-886 alone. MK-886- and MK-886 plus celecoxib-treated animals exhibited reduced levels of the protective interleukin-12 and gamma-interferon. Our findings indicate that in this model, the protective effect of LTs dominates over the suppressive effect of PGs.

Evidence for eosinophil recruitment, leukotriene B4 production and mast cell hyperplasia following Toxocara canis infection in rats.

It is well known that eosinophilia is a key pathogenetic component of toxocariasis. The objective of the present study was to determine if there is an association between peritoneal and blood eosinophil influx, mast cell hyperplasia and leukotriene B(4) (LTB(4)) production after Toxocara canis infection. Oral inoculation of 56-day-old Wistar rats (N = 5-7 per group) with 1000 embryonated eggs containing third-stage (L3) T. canis larvae led to a robust accumulation of total leukocytes in blood beginning on day 3 and peaking on day 18, mainly characterized by eosinophils and accompanied by higher serum LTB(4) levels. At that time, we also noted increased eosinophil numbers in the peritoneal cavity. In addition, we observed increased peritoneal mast cell number in the peritoneal cavity, which correlated with the time course of eosinophilia during toxocariasis. We also demonstrated that mast cell hyperplasia in the intestines and lungs began soon after the T. canis larvae migrated to these compartments, reaching maximal levels on day 24, which correlated with the complete elimination of the parasite. Therefore, mast cells appear to be involved in peritoneal and blood eosinophil infiltration through an LTB(4)-dependent mechanism following T. canis infection in rats. Our data also demonstrate a tight association between larval migratory stages and intestinal and pulmonary mast cell hyperplasia in the toxocariasis model.

Evidence for eosinophil recruitment, leukotriene B4 production and mast cell hyperplasia following Toxocara canis infection in rats

It is well known that eosinophilia is a key pathogenetic component of toxocariasis. The objective of the present study was to determine if there is an association between peritoneal and blood eosinophil influx, mast cell hyperplasia and leukotriene B4 (LTB4) production after Toxocara canis infection. Oral inoculation of 56-day-old Wistar rats (N = 5-7 per group) with 1000 embryonated eggs containing third-stage (L3) T. canis larvae led to a robust accumulation of total leukocytes in blood beginning on day 3 and peaking on day 18, mainly characterized by eosinophils and accompanied by higher serum LTB4 levels. At that time, we also noted increased eosinophil numbers in the peritoneal cavity. In addition, we observed increased peritoneal mast cell number in the peritoneal cavity, which correlated with the time course of eosinophilia during toxocariasis. We also demonstrated that mast cell hyperplasia in the intestines and lungs began soon after the T. canis larvae migrated to these compartments, reaching maximal levels on day 24, which correlated with the complete elimination of the parasite. Therefore, mast cells appear to be involved in peritoneal and blood eosinophil infiltration through an LTB4-dependent mechanism following T. canis infection in rats. Our data also demonstrate a tight association between larval migratory stages and intestinal and pulmonary mast cell hyperplasia in the toxocariasis model.

Autosomal-dominant ankyloglossia and tooth number anomalies.

Ankyloglossia is a congenital oral anomaly characterized by the presence of a hypertrophic lingual frenulum. It frequently accompanies X-linked cleft palate and is sometimes seen alone due to mutations in the gene encoding the transcription factor TBX22, while knockout of Lgr5 in the mouse results in ankyloglossia. The aim of the present study was to characterize the phenotype and to verify sequence variations in the LGR5 gene in a Brazilian family with ankyloglossia associated with tooth number anomalies. Twelve individuals of three generations were submitted to physical, oral, and radiographic examinations and molecular analysis. Eight had ankyloglossia with various degrees of severity. Six also had hypodontia in the lower incisor region; one had a supernumerary tooth in this region, and another had a supernumerary tooth in the lower premolar region. The characterization of this family determined an autosomal-dominant inheritance and excluded the LGR5 gene mutations as being involved in the pathogenesis of this condition.

Penile carcinoma: the role of koilocytosis in groin metastasis and the association with disease specific survival.

PURPOSE: We evaluated the influence of koilocytosis, and other clinical and pathological variables in the risk of groin metastasis and death in penile cancer patients. MATERIALS AND METHODS: From January 1994 to January 2004, 172 patients with squamous cell carcinoma of the penis were treated at a single cancer center. Of these patients 144 were retrospectively studied to analyze prognostic factors and establish the role of koilocytosis in penile cancer. Univariate and multivariate analyses were performed, and Kaplan-Meier survival curves were generated. RESULTS: A total of 102 patients (71%) underwent groin dissection, of whom 84 (58.3%) had inguinal metastasis. Koilocytosis was present in 91 patients (63.1%) and it was associated with low and moderate primary tumor grade on univariate analysis (p = 0.0005). Although koilocytosis statistically correlated with Jackson stage (p = 0.017) and tumor grade (p = 0.002), it had no impact on disease specific survival (p = 0.912). Metastatic inguinal disease correlated with patient age, Jackson and disease specific survival. Only Jackson stage and inguinal relapse after groin dissection influenced overall survival on multivariate analysis (each p = 0.001). CONCLUSIONS: According to all studied variables only patient age and Jackson stage correlated with an increased risk of groin disease. Koilocytosis was rarely found in high grade penile tumors and it did not correlate with a high risk of metastatic groin disease or death.

Neurotropism and neuropathological effects of selected rhabdoviruses on intranasally-infected newborn mice.

Viral neurotropism is the ability of viruses to infect neuronal cells. This is well studied for herpesviruses, rabies-related viruses, and a few others, but it is poorly investigated among almost all arboviruses. In this study, we describe both the neurotropism and the neuropathological effects of Amazonian rhabdoviruses on the brains of experimentally infected-newborn mice. Suckling mice were intranasally infected with 10(-4) to 10(-8) LD50 of viruses. Animals were anaesthetized and perfused after they had become sick. Immunohistochemistry using specific anti-virus and anti-active caspase three antibodies was performed. All infected animals developed fatal encephalitis. Survival time ranged from 18 h to 15 days. Viruses presented distinct species-dependent neurotropism for CNS regions. Histopathological analysis revealed variable degrees of necrosis and apoptosis in different brain regions. These results showed that viruses belonging to the Rhabdoviridae family possess distinct tropism for CNS structures and induce different pattern of cell death depending on the CNS region.

Isolamento do Toxoplasma gondii de exsudato peritoneal e orgaos de camundongos com infeccao experimental / Isolation of Toxoplasma gondii from peritoneal exudate and organs of mice with experimental infection

Foram examinados exsudatos peritoneais e orgaos (cerebro, coracao, pulmao e musculo estriado) de 53 camundongos infectados experimentalmente pelo Toxoplasma gondii, sendo 21 na fase aguda e 32 na cronica. Camundongos albinos, machos, de cerca de 25 g e 2 meses de idade foram inoculados, por via intraperitoneal, com 0,5 ml de exsudato peritoneal (taquizoitas) ou macerado de cerebro (cistos) de camundongos previamente infectados. O exame a fresco foi feito no exsudato peritoneal, entre 3 e 12 dias apos inoculacao e no cerebro, apos 10 dias. Foram realizadas inoculacoes de macerados de orgaos em novos camundongos (repiques) para a recuperacao do parasita no exsudato ou no cerebro. Na infeccao aguda as positividades foram, ao exame a fresco: exsudato peritoneal 19/19, pulmao 12/14, musculo 6/9, coracao 4/9 e cerebro 1/3. Apos inoculacao: exsudato peritoneal 5/5, cerebro 2/2, coracao 19/19, pulmao 13/13 e musculo 14/17. Apos estes ultimos resultados foram registrados 9 novos orgaos positivos. A positividade final (igual a recuperacao do parasita) foi: exsudato peritoneal 19/19 (100 por cento), coracao 15/17 (88,5 por cento), musculo 12/14 (85,7 por cento), pulmao 14/14 (100 por cento) e cerebro 2/3 (66,6 por cento)...

Ação do sal de cozinha sobre o Toxoplasma gondii / Action of table salt on Toxoplasma gondii

O baixo resultado encontrado por nos no isolamento do Toxoplasma gondii de embutidos de carne de porco procedentes de Erechim (RS) (uma positiva em 40 amostras) levou-nos a pesquisar a acao do sal de cozinha, presente nesses embutidos, sobre taquizoitas e cistos do parasita. Foram obtidos exsudatos peritoneais (taquizoitas) e macerados de cerebros (cistos) de camundongos previamente inoculados com cepas de Toxoplasma gondii isoladas do material de Erechim. A este inoculo foi acrescentado sal de cozinha refinado, comum, nas concentracoes de 2,2 por cento, 2,5 por cento e 3,0 por cento habitualmente usadas no preparo dos embutidos. O tempo de exposicao ao sal foi de 24 e 48 horas, 3-5 e 7 dias, a 4 graus Celsius, apos o qual, camundongos albinos, machos, foram inoculados, por via intraperitoneal, com 0,5 ml desses inoculos, padronizados quanto ao numero de parasitas. Os resultados mostraram que, nas concentracoes de sal a 2,2 por cento, 2,5 por cento e 3,0 por cento e exposicoes de 24 e 48 horas, todos os camundongos inoculados com taquizoitas mais sal morreram, menos um, provavelmente nao infectado, (um sobrevivente em 28 inoculados). Na concentracao de 3,0 por cento e exposicao durante 3-5 e 7 dias houve 10 sobreviventes em 37 animais inoculados (27 por cento), sendo que com 5 e 7 dias, 7 de 15 camundongos sobreviveram (46,6 por cento)...