Smell loss associated with SARS-CoV-2 is not clinically different from other viruses: a multicenter cohort study.

BACKGROUND: Although the COVID-19 pandemic has increased the prevalence of cases with olfactory loss, other respiratory viruses can also cause this condition. We aimed to compare the prevalence of acute SARS-CoV-2 infection and other respiratory viruses in patients with sudden smell loss, and to assess the impact of SARS-CoV-2 viral load and co-infection on olfactory symptoms. METHODS: Patients with sudden smell loss were recruited in a multicenter prospective cohort study in 15 hospitals in Brazil. Clinical questionnaire, Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory test and nasopharyngeal swab to perform a PCR-based respiratory viral panel were collected at first visit (day 0) and 30 and 60 days after recruitment. RESULTS: 188 of 213 patients presented positive test result for SARS-CoV-2, among which 65 were co-infected with other respiratory viruses (e.g., rhinovirus, enterovirus, and parainfluenza). 25 had negative test results for SARS-CoV-2. Patients in both SARSCoV-2 and non-SARS-CoV-2 groups had objective anosmia (less than 2 points according to the psychophysical olfactory CCCRC) at day 0, with no significant difference between them. Both groups had significant smell scores improvement after 30 and 60 days, with no difference between them. Co-infection with other respiratory viruses, and SARS-CoV-2 viral load did not impact olfactory scores. CONCLUSION: Patients with sudden smell loss associated with SARS-CoV-2 and other respiratory viruses had similar presentation, with most participants initiating with anosmia, and total or near total recovery after 60 days. SARS-CoV-2 viral load and co-infections with other respiratory viruses were not associated with poorer olfactory outcomes.

Protective effect of sex steroid hormones on morphological and cellular outcomes after neonatal hypoxia-ischemia: A meta-analysis of preclinical studies.

Sex steroid hormones play an important role in fetal development, brain functioning and neuronal protection. Growing evidence highlights the positive effects of these hormones against brain damage induced by neonatal hypoxia-ischemia (HI). This systematic review with meta-analysis aims to verify the efficacy of sex steroid hormones in preventing HI-induced brain damage in rodent models. The protocol was registered at PROSPERO and a total of 22 articles were included. Moderate to large effects were observed in HI animals treated with sex steroid hormones in reducing cerebral infarction size and cell death, increasing neuronal survival, and mitigating neuroinflammatory responses and astrocyte reactivity. A small effect was evidenced for cognitive function, but no significant effect for motor function; moreover, a high degree of heterogeneity was observed. In summary, data suggest that sex steroid hormones, such as progesterone and 17ß estradiol, improve morphological and cellular outcomes following neonatal HI. Further research is paramount to examine neurological function during HI recovery and standardization of methodological aspects is imperative to reduce the risk of spurious findings.

Postoperative radiotherapy in prostate cancer: When and how? - An update review.

Radical prostatectomy (RP) has been found to be curative in most cases of prostate cancer (PCa); however, 20-40% of patients have a biochemical recurrence (BCR) of the disease. Prostatic specific antigen prostate-specific antigen (PSA) levels are used to assess patient prognosis after surgery; however, there is no consensus about the optimal PSA level that defines BCR. Detection of very low volume disease and early detection of the disease are very important predictors for clinical outcomes in BCR, as early salvage radiation therapy (SRT) provides a possibility of a cure. The aim of this study is to review briefly about important and controversies in radiotherapy after radical prostatectomy. No guideline exists to select ideal patients for each treatment, but there are tools currently being developed; genetic tests and prostate-specific membrane antigen (PSMA) positron emission tomography (PET) may be able to identify patients with worse outcomes who would benefit from more treatment.

Determination of Phenolic Acids in Sugarcane Vinasse by HPLC with Pulse Amperometry.

A reversed-phase liquid chromatographic separation with pulsed amperometric detection of phenolic acids at a glassy carbon electrode is described. Chromatographic separation was carried out in isocratic conditions using 0.20 mol·L-1 acetic acid (pH 5.0)/water (80 : 20, v/v) as mobile phase under constant working potential mode of 0.80 V. Chromatographic peaks presented high resolution and separation. Calibration curves exhibited excellent correlation coefficients, above 0.995. Linear ranges of the analytes, in mg L-1, were of 0.018-18 (gallic acid), 0.146-19 (vanillic acid), 0.13-17 (caffeic acid), 0.016-16 (ferulic acid), and 0.008-17 (p-coumaric acid), respectively. Limits of detection ranged from 1.6 to 97 µg·L-1 and precision varied in 1.73-3.78% interval. Concentrations of 19 ± 0.51 mg·L-1 and 7.8 ± 2.5 mg·L-1 were found for vanillic and caffeic acids, respectively, in a sugarcane vinasse sample. Gallic, ferulic, and p-coumaric acids were not detected. Recovery results demonstrated that the proposed method is accurate, and it can be used to detect and quantify phenolic acids in sugarcane vinasse without any influence of interferents.

Synthesis and oxidation of 2-hydroxynevirapine, a metabolite of the HIV reverse transcriptase inhibitor nevirapine.

Nevirapine (11-cyclopropyl-5,11-dihydro-4-methyl-6H-dipyrido[3,2-b:2',3'-e][1,4]diazepin-6-one, NVP) is a non-nucleoside HIV-1 reverse transcriptase inhibitor used to prevent mother-to-child transmission of the virus. However, severe hepatotoxicity and serious adverse cutaneous effects have raised concerns about the safety of NVP administration. NVP metabolism yields several phenol-type derivatives conceivably capable of undergoing further metabolic oxidation to electrophilic quinoid species that could react with bionucleophiles. The covalent adducts thus formed might be at the genesis of toxic responses. As an initial step to test this hypothesis, we synthesized the phenolic metabolite, 2-hydroxy-NVP, and investigated its oxidation in vitro. Using potassium nitrosodisulfonate and sodium periodate as model oxidants, we obtained evidence for fast generation of an electrophilic quinone-imine, which readily underwent hydrolytic conversion to fully characterized spiro derivatives, 1'-cyclopropyl-4-methyl-1H,1'H-spiro[pyridine-2,2'-pyrido[2,3-d]pyrimidine]-3,4',6(3'H)-trione in aqueous media and 1'-cyclopropyl-4-methyl-1'H,2H-spiro[pyridine-3,2'-pyrido[2,3-d]pyrimidine]-2,4',6(1H,3'H)-trione in non-aqueous media. The spiro compound generated in aqueous solution underwent subsequent hydrolytic degradation of the NVP ring system, whereas the one formed in non-aqueous media was stable to hydrolysis. The product profile observed with the chemical oxidants in aqueous solution was replicated using lactoperoxidase-mediated oxidation of 2-hydroxy-NVP. These observations suggest that metabolic activation of NVP, via Phase I oxidation to 2-hydroxy-NVP and subsequent generation of a quinone-imine, could occur in vivo and play a role in NVP-induced toxicity.

Geometrical content of Leslie coefficients.

In this work, we will study how the effective geometry acquired by nematic molecules under thermal vibration contribute to the determination of the Leslie coefficients. To do this, we will divide this work in two sections. In the first section, we present the geometrical fundamentals of the so-called Hess-Baalss (HB) approach [D. Baalss and S. Hess, Phys. Rev. Lett. 57, 86 (1986)] where we show that its basic assumptions can be understood as a geometrical interpretation of de Gennes' passage from the microscopic to the macroscopic order parameter. In the second section, we use an extended version of the HB approach [M. Simões, K. Yamaguti, and A. J. Palangana, Phys. Rev. E 80, 061701 (2009)] to obtain the geometrical contribution to each Leslie coefficient. Our results will be compared with experimental data, and we will show that the Miesowicz's coefficients are connected as long as the ratio α(3)/α(4) between these Leslie coefficients can be considered small.

Evidence for a subtle structural symmetry breaking in EuB(6).

This work presents a systematic Raman scattering study and first-principles calculations for the EuB(6) system. Evidence for the presence of an incipient (∼1 × 10(-4) Å) tetragonal symmetry break of its crystalline structure was found. Forbidden Raman modes at ω(fRm(1))∼1170 cm(-1), ω(fRm(2))∼1400 cm(-1), and ω(fRm(3))∼1500  cm(-1) were observed. The tetragonal symmetry of ω(fRm(2)) and ω(fRm(3)) together with spin-polarized first-principles simulations of the structural and magnetic properties fully support such a break of symmetry. Our data and calculations explain the occurrence of ferromagnetism in Eu hexaborides, previously reported.

Epithelial cells treated with genistein inhibit adhesion and endocytosis of Paracoccidioides brasiliensis.

Paracoccidioidomycosis is caused by Paracoccidioides brasiliensis, which although not formally considered an intracellular pathogen, can be internalized by epithelial cells in vitro and in vivo. The mechanisms used by P. brasiliensis to adhere to and invade non-professional phagocytes have not been identified. The signal-transduction networks, involving protein tyrosine kinase (PTK) and protein phosphatase activities, can modulate crucial events during fungal infections. In this study, the involvement of PTK has been investigated in P. brasiliensis adherence and invasion in mammalian epithelial cells. A significant inhibition of the fungal invasion occurred after the pre-treatment of the epithelial cells with genistein, a specific tyrosine kinase inhibitor, indicating that the tyrosine kinase pathway is involved in P. brasiliensis internalization. In contrast, when the fungus was treated, a slight (not significant) inhibition of PTK was observed, suggesting that PTK might not be the fungus' transduction signal pathway during the invasion process of epithelial cells. An intense PTK immunofluorescence labeling was observed in the periphery of the P. brasiliensis infected cells, little PTK labeling was found in both uninfected cells and yeast cells, at later infection times (8 and 24 h). Moreover, when the epithelial cells were treated with genistein and infected with P. brasiliensis, no labeling was observed, suggesting the importance of the PTK in the infectious process. These results suggest that PTK pathway participates in the transduction signal during the initial events of the adhesion and invasion processes of P. brasiliensis to mammalian epithelial cells.

Interação de Paracoccidioides brasiliensis com células endoteliais / Interaction of Paracoccidioides brasilienses with endothelial cells

A paracoccidioidomicose apresenta um amplo espectro de manifestações clínicas e Paracoccidioides brasiliensis, seu agente etiológico, pode atingir vários tecidos com ênfase ao pulmão. A migração de fungos patogênicos através da camada de células endoteliais é considerada pré-requisito para a invasão de múltiplos órgãos e sua disseminação. No presente estudo verificou-se a adesão de P. brasiliensis às células endoteliais in vitro e se esta adesão poderia representar um mecanismo para a disseminação do fungo. Para tanto, além da técnica convencional de microscopia ótica, uma outra metodologia foi desenvolvida, emblocando os cordões umbilicais em parafina, no intuito de detectar o fungo presente no material (in vivo). Experimento de migração de P. brasiliensis através da monocamada de células endoteliais também foi realizado, e nos poços sem células, a migração de células leveduriformes foi maior em menor período de tempo. Os fungos conseguiram passar através da monocamada, quando comparados com o controle sem as células, mas com redução em torno de 30%. Isso mostra que a monocamada foi parcialmente impediente para o fungo, mas que este foi capaz de migrar através dessas células. Em nossos experimentos com estas células, houve grande dificuldade de se encontrar P. brasiliensis aderido ao tapete celular nos períodos de tempo padronizados. Sugere-se com esses resultados que o fungo atravessa as células endoteliais de uma maneira muito rápida, que não pode ser detectada através do cultivo in vitro. Portanto, P. brasiliensis teria capacidade de atravessar rapidamente as células endoteliais e provavelmente alcançar tecidos mais profundos

Heme oxygenase isoform-specific expression and distribution in the rat kidney.

BACKGROUND: The heme oxygenase (HO) genes, HO-1 and HO-2, are the limiting steps in heme degradation and in the regulation of renal heme-dependent enzymes. Previously we reported that selective overexpression of renal HO-1 resulted in a decrease of microsomal heme and the cytochrome P450-dependent arachidonic acid metabolite, 20 HETE, a vasoconstrictor. The present study was undertaken to explore the relative expression and contribution of each of the HO isoforms to HO activity in the rat kidney. METHODS AND RESULTS. Renal HO activity increased above control levels after an injection of the inducers of HO activity, heme or SnCl2. Stannous Mesoporphyrin (SnMP), a nonselective inhibitor of HO, when used alone or in combination with heme or SnCl2, decreased HO activity. Heme alone and combined with SnCl2 decreased the levels of heme content by 13 and 35%, respectively. Western blot analysis showed that both SnCl2 and heme readily induced HO-1 protein, whereas HO-2 was constitutively expressed. Immunohistochemistry showed the distribution of the HO-1 isoform primarily in proximal convoluted tubules. Western blot analysis exhibited relatively higher levels of HO-1 in isolated proximal tubules and relatively higher HO-2 levels in the thick ascending limbs of the loop of Henle and preglomerular arterioles. In vivo administration of HO-1 and HO-2 antisense oligodeoxynucleotides further confirmed that HO-2, but not HO-1, contributed to the basal HO activity; however, following induction of HO with heme, antisense to HO-1, but not to HO-2, inhibited the induced levels of HO activity. CONCLUSION: These results suggest that HO-2 is constitutively expressed in the rat kidney mainly within tubular and arteriolar structures, and its activity may modulate physiological function under basal conditions. On the other hand, the basal levels of expression of HO-1 in the rat kidney are relatively low, and its contribution to HO activity and the regulation of hemoproteins such as cytochrome P450 become apparent only under pathophysiological conditions causing HO induction.

[An integrated medical image network of patient records: experience of the Picture Archiving and Communication System (PACS) of the Gustave-Roussy Institute]. / Un réseau d'images médicales intégrées au dossier du patient: expérience du Picture Archiving and Communication System (PACS) de l'Institut Gustave-Roussy.

The PACS (Picture Archiving and Communication System) is a central radiologic image archiving system coupled with an information system which allows rapid access to these images. It permits rapid access of the entire file of radiologic images of a patient for radiologists and clinicians. After installation of an MRI and CT scan unit at the IGR, a PACS system was installed in July, 2000. The preparation phase and characteristics of the PACS system at the IGR are described here. The data in the literature and the short experience of the PACS system at the IGR show benefits of this system at several levels: improved efficiency (for technicians, radiologists, and secretaries), improved image quality and interpretation, improved clinical management of patients resulting from more timely image interpretation and execution of clinical decisions, increased ease of image transfer for tele-imagery, and improved teaching and publication possibilities. The PACS significantly modifies work habits since the interpretation and consultation of images is done exclusively at the console and progressively obviates the need for actual films.

Adherence and intracellular parasitism of Paracoccidioides brasiliensis in Vero cells.

Paracoccidioides brasiliensis is a dimorphic fungus known to produce invasive systemic disease in humans. The 43-kDa glycoprotein of P. brasiliensis is the major diagnostic antigen of paracoccidioidomycosis and may act as a virulence factor, since it is a receptor for laminin.Very little is known about early interactions between this fungus and the host cells, so we developed in vitro a model system employing cultured mammalian cells (Vero cells), in order to investigate the factors and virulence mechanisms of P.brasiliensis related to the adhesion and invasion process. We found that there is a permanent interaction after 30 min of contact between the fungus and the cells. The yeasts multiply in the cells for between 5 and 24 h. Different strains of P. brasiliensis were compared, and strain 18 (high virulence) was the most strongly adherent, followed by strain 113 (virulent), 265 (considered of low virulence) and 113M (mutant obtained by ultraviolet radiation, deficient in gp43). P. brasiliensis adhered to the epithelial cells by a narrow tube, while depressions were noticed in the cell surface, suggesting an active cavitation process. An inhibition assay was performed and it was verified that anti-gp43 serum and a pool of sera from individuals with paracoccidioidomycosis were able to inhibit the adhesion of P. brasiliensis to the Vero cells. Glycoprotein 43 (gp43) antiserum abolished 85% of the binding activity of P. brasiliensis. This fungus can also invade the Vero cells, and intraepithelial parasitism could be an escape mechanism in paracoccidioidomycosis.

Characterization of a Rab11 homologue in Trypanosoma cruzi.

Vesicle trafficking between organelles occurs through fusion of donor and specific acceptor membranes. This process is highly regulated and ensures proper direction in sorting and packaging of a number of molecules in eukaryotic cells. Monomeric GTPases of the Rab family play a pivotal role in the control of membrane fusion and vesicle traffic. In this paper, we characterize a Trypanosoma cruzi Rab 11 homologue (TcRab11) that shares at, the amino acid level, 40% similarity with human rab11, Arabdopsis thaliana rab11 and yeast rab11 homologue genes. Western blot analysis, using a polyclonal rabbit antiserum raised against a synthetic peptide derived from the COOH-terminus of predicted the TcRab11 protein, reacted to a 26kDa protein. In immunofluorescence assays, TcRab 11, was shown to be expressed in epimastigote and amastigote forms, but it was absent in trypomastigotes. Interestingly, the TcRab11 product seems to be located at the reservosome complex, a site of active endocytosis and vesicle fusion present only in the epimastigote stage. Therefore, TcRab11 may represent the first molecular marker of this peculiar organelle.

Pathogenesis II: fungal responses to host responses: interaction of host cells with fungi.

Most of our knowledge concerning the virulence determinants of pathogenic fungi comes from the infected host, mainly from animal models and more recently from in vitro studies with cell cultures. The fungi usually present intra- and/or extracellular host-parasite interfaces, with the parasitism phenomenon dependent on complementary surface molecules. Among living organisms, this has been characterized as a cohabitation event, where the fungus is able to recognize specific host tissues acting as an attractant, creating stable conditions for its survival. Several fungi pathogenic for humans and animals have evolved special strategies to deliver elements to their cellular targets that may be relevant to their pathogenicity. Most of these pathogens express surface factors that mediate binding to host cells either directly or indirectly, in the latter case binding to host adhesion components such as extracellular matrix (ECM) proteins, which act as 'interlinking' molecules. The entry of the pathogen into the host cell is initiated by fungal adherence to the cell surface, which generates an uptake signal that may induce its cytoplasmic internalization. Once this is accomplished, some fungi are able to alter the host cytoskeletal architecture, as manifested by a rearrangement of microtubule and microfilament proteins, and this can also induce epithelial host cells to become apoptotic. It is possible that fungal pathogens induce modulation of different host cell pathways in order to evade host defences and to foster their own proliferation. For a number of pathogens, the ability to bind ECM glycoproteins, the capability of internalization and the induction of apoptosis are considered important factors in virulence. Furthermore, specific recognition between fungal parasites and their host cell targets may be mediated by the interaction of carbohydrate-binding proteins, e.g., lectins on the surface of one type of cell, probably a parasite, that combine with complementary sugars on the surface of host-cell. These interactions supply precise models to study putative adhesins and receptor-containing molecules in the context of the fungus-host interface. The recognition of the host molecules by fungi such as Aspergillus fumigatus, Paracoccidioides brasiliensis and Histoplasma capsulatum, and their molecular mechanisms of adhesion and invasion, are reviewed in this paper.

Negative regulation of human heme oxygenase in microvessel endothelial cells by dexamethasone.

Heme oxygenase-1 (HO-1) is a stress protein, and its induction has been suggested to participate in defense mechanisms against agents that promote oxidative injury such as endotoxins and heme. We have shown that the inflammatory cytokines, interleukin-6 (IL-6) and heme-induced HO-1 gene expression, were suppressed by dexamethasone (Dex) in a sustained manner. We examined the mechanism by which the anti-inflammatory agent, Dex, inhibits IL-6 and heme-induced HO-1 expression in rabbit coronary endothelial cells. Endothelial cells treated with heme (10 microM) and IL-6 (25 ng/ml), increased HO-1 mRNA 15- and 60-fold, respectively. The activity of HO was increased 3-fold after such treatment. Although Dex failed to inhibit heme-mediated HO-1 mRNA and HO activity, it was able to reverse IL-6-stimulated HO activity. Several human HO-1 promoter-drive chloramphenicol acetyltransferase (CAT) constructs were examined to analyze IL-6 and Dex-mediated modulation of the HO-1 gene in endothelial cells. CAT assays revealed that the HO-1 promoter region between -180 and -1500 might contain a Dex-mediated negative regulator. Gel mobility shift assays using nuclear extracts from IL-6-treated endothelial cells showed a binding to the synthetic 21 base pairs of the HO-1 sequence that contains the putative STAT3 sequence. STAT3-specific probe inhibited nuclear binding protein to the putative HO-1-STAT3 sequence. This suggests that IL-6 induction of human HO-1 is mediated via the JAK-STAT pathway and that Dex inhibition of gene expression is carried out by activation of a transcriptional protein in competition with the STAT3 binding site.

Differential effects of heme oxygenase isoforms on heme mediation of endothelial intracellular adhesion molecule 1 expression.

Heme oxygenase (HO), by catabolizing heme to bile pigments, down-regulates cellular hemoprotein, hemoglobin, and heme; the latter generates pro-oxidant products, including free radicals. Two HO isozymes, the products of distinct genes, have been described; HO-1 is the inducible isoform, whereas HO-2 is suggested to be constitutively expressed. We studied the inducing effect of several metal compounds (CoCl(2), stannic mesoporphyrin, and heme) on HO activity. Additionally, we studied HO-1 expression in experimental models of adhesion molecule expression produced by heme in endothelial cells, and the relationship of HO-1 expression to the induced adhesion molecules. Flow cytometry analysis showed that heme induces intracellular adhesion molecule 1 (ICAM-1) expression in a concentration (10-100 microM)- and time (1-24 h)-dependent fashion in human umbilical vein endothelial cells. Pretreatment with stannic mesoporphyrin, an inhibitor of HO activity, caused a 2-fold increase in heme-induced ICAM-1 expression. In contrast, HO induction by CoCl(2) decreased heme-induced ICAM-1 expression by 33%. To examine the contribution of HO-1 and HO-2 to endothelial HO activity, specific antisense oligonucleotides (ODNs) of each isoform were tested for their specificity to inhibit HO activity in cells exposed to heme. Endothelial cells exposed to heme elicited increased HO activity, which was prevented (70%) by HO-1 antisense ODNs. HO-2 antisense ODN inhibited heme-induced HO activity by 21%. Addition of HO-1 antisense ODNs prevented heme degradation and resulted in elevation of microsomal heme. Western blot analysis showed that HO-1 antisense ODNs selectively inhibited HO-1 protein and failed to inhibit HO-2 protein. Incubation of endothelial cells with HO-1 antisense enhanced heme-dependent increase of ICAM-1. In contrast, addition of HO-2 antisense to endothelial cells failed to increase adhesion molecules. The role of glutathione, an important antioxidant, was examined on heme-induced ICAM-1 expression. Endothelial cells pretreated with a glutathione precursor, N-acetylcysteine, or glutathione ester, showed a decrease in heme-induced ICAM-1 expression of 37 and 44%, respectively, suggesting that the mechanism of ICAM-1 induction by heme may be partly dependent on the levels of antioxidant. It is possible that amelioration of the heme-induced oxidative stress and expression of ICAM-I is due, in part, to the induction of HO-1 activity. Regulation of HO activity in this manner may have clinical applications.

Retinal pigment epithelial cell-based gene therapy against hemoglobin toxicity.

To determine if overexpression of the human heme oxygenase (HO-1) protects retinal pigment (RPE) cells from hemoglobin toxicity, a human RPE cell line was infected by an adenoviral vector containing the HO-1 (Ad-HO-1) gene or transfected with a plasmid containing the cytomegalovirus promoter and HO-1 cDNA (pRc/CMV-HO-1) complexed to cationic liposomes. Phase contrast microscopy and acid phosphatase activity were examined to insure homogeneity of the cell line. Mitochondrial cytochrome and microsomal heme content were measured in both transduced and control cells. RPE cells were then challenged with hemoglobin and their viability estimated. We determined that cells transfected with Ad HO-1 overexpressed HO-1 compared to control cells: HO-1 mRNA levels were increased 3-fold within 3 days, decreasing in 7 days. In addition, we permanently transfected RPE cells with HO-1 gene. Transfected cell clones selected for neomycin resistance had elevated levels of HO activity 3-fold higher than control. Transfected cells exposed to hemoglobin had a survival rate of 93%; non-transfected cells had a 65-75% rate of survival. Transfected cells overexpressing HO-1 proved highly viable when challenged with hemoglobin. HO-1 appears to be an important component of the cellular anti-oxidant defense mechanisms against hemoglobin toxicity. However, the choice of transient or permanent expression of HO-1 against hemoglobin toxicity and hemorrhage needs to be further evaluated.

Myoelectric activity during unilateral chewing in healthy subjects: cycle duration and order of muscle activation.

STATEMENT OF PROBLEM: Craniomandibular disorders, unilateral mastication, and asymmetry of masticatory muscles appear to be related to each other. Thus, it is of interest to investigate masticatory muscle activity during unilateral mastication in healthy subjects. PURPOSE: This study monitored contractile activity of the right and left masticatory muscles during right- and left-side gum chewing. MATERIAL AND METHODS: Electromyographic techniques were used to determine chewing cycle duration and duration of contractile activity of the masticatory muscles (right and left masseter and anterior temporalis muscles) during unilateral chewing in 40 subjects without orofacial pain. The time-course of activation of the 4 muscles was also investigated. RESULTS: Electromyographic traces showed extensive interindividual variation. In both right- and left-side chewing tests, and regardless of whether the masseter or the temporalis muscles were considered, mean duration of the contraction phase did not differ significantly between the working and nonworking sides. The working side temporalis contracted first, whether alone or at the same time as the other muscles. CONCLUSIONS: In healthy subjects, no significant differences in masticatory muscle activity should be expected between either the right and left or the working and nonworking sides.

[Spinal cord injuries in children]. / Traumatismo raquimedular em crianças.

Spinal cord injuries are rare in children, in face of their higher mobility comparing to adults. The high cervical and the thoracic segments of the spine are more frequently affected. In the last 10 years we had 90 cases of spinal injuries in our service being 12 with neurologic deficient (8 male and 4 female) and four of them without radiographic abnormality, even in the dynamics studies. The authors emphasise the possibility of occurrence of neurologic deficit in children after trauma, even without any radiographic abnormality.