Desmineralización de la Dentina Humana Producida por Irrigantes Endodónticos Combinados

El objetivo de este trabajo fue evaluar el efecto de soluciones de irrigación endodónticas solas y combinadas sobre iones calcio y fosfato de la dentina radicular ex vivo. Se emplearon 56 discos de dentina obtenidos del tercio medio radicular de premolares inferiores unirradiculares extraídos por razones ortodóncicas. Los discos se dividieron al azar en 8 grupos (n=7). Grupo I: agua destilada (AD), Grupo II: hipoclorito de sodio (NaClO) 1 %, Grupo III: EDTA 17 %, Grupo IV: ácido maleico (AM) 5 %, Grupo V: ácido acético (AA) 5 %, Grupo VI: EDTA 17 % + NaClO 1 %, Grupo VII: AM 5 % + NaClO 1 %, Grupo VIII: AA 5 % + NaClO 1 %. Los segmentos de dentina permanecieron en contacto a 37° C durante 5 min y 2,5 minutos en cada solución cuando se usaron en forma sucesiva. Se determinó la concentración de iones calcio de las soluciones mediante espectrometría de absorción atómica y la concentración de iones fosfatos mediante colorimetría (Wienner Lab.). Los resultados se expresaron en mg/ml/gr de tejido. Para el análisis estadístico se utilizó ANOVA y Test de Tukey. AA 5 % y EDTA 17 % se comportaron de manera similar utilizados solos durante 5 minutos, NaClO 1 % no mostró diferencias con el AD. AM 5 % eliminó significativamente más calcio y fosfato que todos los grupos. Todas las soluciones desmineralizaron la dentina, pero AM 5 % durante 5 min fue la solución que más afectó el componente inorgánico de la dentina.

The aim of the present study was to evaluate ex vivo irrigating solutions effect under calcium and phosphates dentin ions, using them alone and combined. In this study 56 dentin discs where used. They were obtained from middle third of mandibular single-root premolars extracted for orthodontics reasons. Discs were randomly divided into 8 groups (n:7). Group I: Distilled water (DW), Group II: 1 % sodium hypochlorite (NaOCl), Group III: 17 % EDTA, Group IV: 5 % maleic acid (MA), Group V: 5 % acetic acid (AA), Group VI: 17 % EDTA + 1 % NaOCl, Group VII: 5 % MA + 1 % NaOCl, Group VIII: 5 % AA + 1 % NaOCl. Dentin segments were kept in contact with irrigating solutions at 37°C for 5 minutes, when used alone, or for 2.5 minutes when used combined. After that, calcium ions (using absorption atomic spectrometry) and phosphorus ions (by colorimetry Wienner Lab.) were determined. Results were expressed in mg/ml/g tissue. Statistical analysis was performed by ANOVA and Tukey test. 5 % AA and 17 % EDTA eliminated similar concentrations of calcium and phosphates ions from dentin at 5 minutes exposure time, while 1 % NaOCl did not present statistical differences with control. 5 % MA eliminated significantly more calcium and phosphates ions than the rest of analyzed groups. Every tested solutions demineralized human dentin, but 5 % MA used for 5 minutes did it the most.

Could pulmonary low-dose radiation therapy be an alternative treatment for patients with COVID-19 pneumonia? Preliminary results of a multicenter SEOR-GICOR nonrandomized prospective trial (IPACOVID trial).

PURPOSE: To evaluate the efficacy and safety of lung low-dose radiation therapy (LD-RT) for pneumonia in patients with coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: Inclusion criteria comprised patients with COVID-19-related moderate-severe pneumonia warranting hospitalization with supplemental O2 and not candidates for admission to the intensive care unit because of comorbidities or general status. All patients received single lung dose of 0.5 Gy. Respiratory and systemic inflammatory parameters were evaluated before irradiation, at 24 h and 1 week after LD-RT. Primary endpoint was increased in the ratio of arterial oxygen partial pressure (PaO2) or the pulse oximetry saturation (SpO2) to fractional inspired oxygen (FiO2) ratio of at least 20% at 24 h with respect to the preirradiation value. RESULTS: Between June and November 2020, 36 patients with COVID-19 pneumonia and a mean age of 84 years were enrolled. Seventeen were women and 19 were men and all of them had comorbidities. All patients had bilateral pulmonary infiltrates on chest X­ray. All patients received dexamethasone treatment. Mean SpO2 pretreatment value was 94.28% and the SpO2/FiO2 ratio varied from 255 mm Hg to 283 mm Hg at 24 h and to 381 mm Hg at 1 week, respectively. In those who survived (23/36, 64%), a significant improvement was observed in the percentage of lung involvement in the CT scan at 1 week after LD-RT. No adverse effects related to radiation treatment have been reported. CONCLUSIONS: LD-RT appears to be a feasible and safe option in a population with COVID-19 bilateral interstitial pneumonia in the presence of significant comorbidities.

Vitiligo in equine: a four-year case study of a roan horse - case report / [Vitiligo em equinos: um estudo de caso de quatro anos de um cavalo roan - relato de caso]

Vitiligo is a dermatological disease affecting both animals and humans. It is characterized by depigmented macules of varying shape and size, originated from melanocyte destruction. Even though there are some theories tackling causation, disease etiopathology is not yet certain. Moreover, lesion areas can either increase or diminish over time, and therefore, available treatment alternatives tend to prove inconsistencies. No epidemiological data or registered cases were found for equines in Brazil. The horse in this case description displayed depigmentation areas in facial regions, including upper lip, nose and lips. However, the individual did not happen to develop any systemic alteration. Through clinical evaluation, backed by a histopathological exam, a definitive vitiligo diagnosis was obtained. However, no therapeutic plan was stipulated. The animal was accompanied for four years, during which period some affected areas diminished while others increased in size. In addition, emergence of new skin lesions was also observed during the time the animal was studied. Overall, this disease does not display alterations to organism functionality, only aesthetic changes. Therefore, treatment plans may vary from case to case, occasionally being even ruled out.(AU)

O vitiligo é uma doença dermatológica que pode afetar animais e humanos. Caracteriza-se por áreas despigmentadas, de formas e tamanhos variáveis, que surgem devido a destruição dos melanócitos. Existem algumas teorias que tentam explicar a etiopatogenia da doença, entretanto ainda não é totalmente esclarecida. As lesões podem aumentar ou diminuir com o tempo, por isso os tratamentos disponíveis são inconsistentes. Não foram encontrados dados epidemiológicos ou relatos de vitiligo em cavalos no Brasil. O equino deste relato apresentava lesões despigmentadas na região da face, incluindo pálpebras, narina e lábios, sem alterações sistêmicas. Por meio da avaliação clínica em conjunto com o exame histopatológico obteve-se o diagnóstico definitivo de vitiligo. Não foi instituído nenhuma terapia, e o equino foi acompanhado durante quatro anos. Durante esse período algumas lesões diminuíram e outras aumentaram de tamanho sendo também observado o aparecimento de novas lesões. O vitiligo não traz alterações sistêmicas, apenas mudanças estéticas, por isso a escolha pelo tratamento dependerá de cada caso.(AU)

Idiopathic seasonal alopecia in horse: case report / Alopecia sazonal idiopática em equino: relato de caso

This report describes the first case of idiopathic seasonal alopecia in a horse in Brazil. The disease is of unknown etiology, characterized by alopecic processes in the thoracic and lateral abdominal regions, in a bilaterally symmetrical way. An eight-year-old male grade horse was treated presenting hair loss in a bilaterally symmetrical manner in the arm and abdomen areas, without any other associated clinical signs. The areas with alopecia showed no pruritus, inflammation or scaling. On the epidermis, the histological evaluation presented irregular hyperplasia, hyperpigmentation, compact orthokeratosis, edema and an inflammatory infiltrate. The hair follicles were active and containing hair shaft. The case was monitored with photographic records for two consecutive years (2012 to 2014), in which the hair fall occurred at the end of autumn with spontaneous hair growth in the middle of the summer. The diagnosis was based on the history, histopathology and photographic follow-up performed. Although mentioned in the literature, this is the first clinical and pathological description of such disorder affecting an equine in Brazil.(AU)

Relata-se o primeiro caso de alopecia sazonal idiopática em um equino no Brasil, doença de etiologia desconhecida, caracterizada por processos alopécicos, nas regiões torácicas e abdominais laterais, de forma simétrica bilateralmente. Um equino mestiço, macho, de oito anos de idade, foi atendido sob queixa de perda dos pelos em regiões do tórax e do abdômen, simétrica bilateralmente, sem qualquer outro sinal clínico associado. As regiões alopécicas não apresentavam prurido, inflamação nem descamação. A avaliação histológica revelou, na epiderme, hiperplasia irregular, hiperpigmentação e ortoqueratose compacta, edema e infiltrado inflamatório. Os folículos pilosos estavam ativos e contendo hastes de pelos. O caso foi acompanhado com registros fotográficos durante dois anos consecutivos (2012 a 2014), com a queda do pelo acontecendo no final do outono e com retorno espontâneo em meados do verão. O diagnóstico baseou-se no histórico, na histopatologia e no acompanhamento fotográfico. Mesmo sendo mencionada na literatura, esta é a primeira descrição clínico-patológica de tal distúrbio acometendo um equino no Brasil.(AU)

Stephanofilariasis in beef cattle - case report / Estefanofilariose em bovinos de corte - relato de caso

Stephanofilariasis is an ulcerative dermatitis caused by nematodes that affect cattle in several countries in the world. However, it has not been described in beef cattle in Brazil. The objective of this study is to describe three cases of stephanofilariasis, which occurred in beef cows in the municipality of Ipê, RS, Brazil. The disease was characterized by pruritic, ulcerated and crusty seasonal lesions present in the cranial region of the udder. The diagnosis was confirmed by analyses of secretions stained smears and by direct optical microscopic examination of the sediment and the treatment was effectively carried out with topical trichlorphon. This report indicates that stephanofilariasis should be included as a differential diagnosis for dermatopathies in beef cattle in Brazil.(AU)

A estefanofilariose é uma dermatite ulcerativa causada por nematódeos que acometem bovinos em vários países do mundo, no entanto não tem sido descrita em bovinos de corte no Brasil. O objetivo do trabalho é a descrição de três casos de estefanofilariose em vacas de corte ocorridos no município de Ipê, RS. A enfermidade foi caracterizada por lesões sazonais pruriginosas, ulceradas e crostosas, presentes na região cranial do úbere. O diagnóstico foi confirmado pela análise dos esfregaços corados das secreções e por exame direto do sedimento em microscopia óptica, e o tratamento foi realizado de maneira eficaz com triclorfon tópico. Este relato demonstra que a estefanofilariose deve ser incluída como diagnóstico diferencial nas dermatopatias em bovinos de corte no Brasil.(AU)

Human prostasomes from normozoospermic and non-normozoospermic men show a differential protein expression pattern.

Prostasomes are exosomes such as extracellular vesicles, produced in the prostatic epithelium and released into the seminal plasma, that play an important role enhancing male fertility. Although some studies have demonstrated that prostasomes have a rich proteomic content, it is still unclear if that proteomic content varies depending on the male fertility status. Prostasomes from 12 normozoospermic and 14 non-normozoospermic seminal samples were isolated by differential ultracentrifugation. Protein content was studied by quantitative mass spectrometry and compared between both cohorts. We identified 1282 proteins with 745 of them (57.8%) being present in all seven prostasome pools. Forty-seven of those commonly present proteins showed differential expression levels in both cohorts. Specifically, prostasomes from non-normozoospermic samples showed a pattern of protein underexpression for a group of proteins including several proteins from the spermatozoa's energy production pathways as well as some proteins directly implicated in sperm activity. Variations in prostasomal protein content levels may have a relevant correlation with male fertility and thus could be of great utility as a biomarker of fertility status.

Systemic toxic reaction due to multiple honeybee stings in equine: Case report / Reação tóxica sistêmica devido a múltiplas ferroadas de abelha em equino: relato de caso

Accidents caused by insects of the Hymenoptera are rarely described in large animals. The attacks caused by honeybee (Apis mellifera) may cause severe consequences and its intensity changes according to the number of stings. Local and systemic reactions can occur, including progression to death. This report describes a case of honeybee attack on an equine, which took place in the city of Lages, in the state of Santa Catarina, Brazil. In the clinical assessment the horse showed apathy, anorexia, head and pectoral edemas, dyspnea, icteric mucosa, increased mandibular lymph nodes and darkened urine. The blood count showed anemia and serum biochemical tests suggested, muscular and hepatic lesions. The urinalysis test indicated hemoglobinuria and increased clotting time. Treatment included lactate Ringer's solution fluid therapy, furosemide, promethazine, corticosteroids and 20% mannitol solution. Hot and cold compresses were applied alternately on areas with edema. There was a satisfactory response to treatment and the animal was discharged after 30 days in veterinary hospital. The description of honeybee sting accidents in large animals is important because of the evolution that can lead to death. The early approach associated with appropriate treatment, avoiding the worsening of the lesions is fundamental for the recovery of the patient.(AU)

Os acidentes causados por insetos da ordem Hymenoptera são raramente descritos em grandes animais. Os ataques provocados por abelhas (Apis mellifera) causam consequências graves, e sua intensidade varia de acordo com a quantidade de ferroadas. Reações locais a sistêmicas podem ocorrer, incluindo a evolução para a morte. Este relato descreve um caso de ataque por abelhas em equino, ocorrido no município de Lages, SC. No exame clínico, o equino apresentava apatia, anorexia, edema de cabeça e região peitoral, dispneia inspiratória, mucosas ictéricas, linfonodos mandibulares aumentados e urina de coloração marrom-escura. O hemograma evidenciou anemia hemolítica, e os exames de bioquímica sérica sugeriram lesão muscular e lesão hepática. A urinálise demonstrou hemoglobinúria, e o tempo de coagulação apresentava-se aumentado. Como tratamento, foram administrados solução de ringer com lactato, furosemida, prometazina, corticosteroides e solução de manitol a 20%. Compressas quentes e frias foram aplicadas alternadamente sobre as áreas de edema. Houve adequada resposta ao tratamento instituído e o animal recebeu alta hospitalar após 30 dias de internamento. A descrição de casos de acidentes por picadas de abelhas em grandes animais é importante devido à evolução, que pode levar à morte. A abordagem precoce associada ao tratamento adequado, evitando o agravamento das lesões, é fundamental para a recuperação do paciente.(AU)

Alteraciones de la hemostasia y trombosis asociadas a enfermedad tiroidea, a propósito de 2 casos / Changes in haemostasis and thrombosis associated with thyroid disease: Presentation of 2 cases

Existe una relación entre las enfermedades tiroideas y las alteraciones de la hemostasia primaria y secundaria. La asociación más repetida en esta línea son los estados de hipocoagulabilidad con el hipotiroidismo clínico y la trombofilia vascular (hipercoagulabilidad y/o hipofibrinólisis) con el hipertiroidismo. Sin embargo, existen estudios recientes que han detectado alteraciones de la hemostasia -primaria y secundaria- relacionadas con enfermedades tiroideas con hormonas normales, evidenciando otros mecanismos patogénicos aún desconocidos. Presentamos el caso de 2 pacientes con enfermedades tiroideas que requerían cirugía: un bocio multinodular y un carcinoma papilar de tiroides, ambos con hormonas normales y que presentaron trastornos de la hemostasia descubiertos en el estudio preoperatorio, revelando un déficit de factor vii y un déficit de factor xi junto con una trombopatía no filiada, respectivamente (AU)

There is a relationship between thyroid diseases and primary and secondary changes in haemostasis. The most frequent association between them are hypocoagulability states with clinical hypothyroidism and vascular thrombophilia (hypercoagulability and/or hypofibrinolysis) with hyperparathyroidism. However, there are recent studies that have detected changes in haemostasis -primary and secondary- associated with thyroid diseases with normal hormone levels, suggesting other pathogenic mechanisms not yet known. The cases are presented of 2 patients with thyroid disease that required surgery: one multinodular goitre and one papillary carcinoma of the thyroid, both with normal hormone levels. They were shown to have haemostasis disorders during the preoperative work up. These showed a Factor VII deficiency and a Factor XI deficiency along with a thrombotic disease of unknown origin, respectively (AU)

Changes in haemostasis and thrombosis associated with thyroid disease: Presentation of 2 cases. / Alteraciones de la hemostasia y trombosis asociadas a enfermedad tiroidea, a propósito de 2 casos.

There is a relationship between thyroid diseases and primary and secondary changes in haemostasis. The most frequent association between them are hypocoagulability states with clinical hypothyroidism and vascular thrombophilia (hypercoagulability and/or hypofibrinolysis) with hyperparathyroidism. However, there are recent studies that have detected changes in haemostasis -primary and secondary- associated with thyroid diseases with normal hormone levels, suggesting other pathogenic mechanisms not yet known. The cases are presented of 2 patients with thyroid disease that required surgery: one multinodular goitre and one papillary carcinoma of the thyroid, both with normal hormone levels. They were shown to have haemostasis disorders during the preoperative work up. These showed a Factor VII deficiency and a Factor XI deficiency along with a thrombotic disease of unknown origin, respectively.

Characterization of Neuwiedin, a new disintegrin from Bothrops neuwiedi venom gland with distinct cysteine pattern.

Disintegrins are cysteine-rich toxins containing the RGD motif exposed in a loop that binds integrins such as αIIbß3, α5ß1 and αvß3. The flexibility of the RGD loop, controlled by the profile of the cysteine pairs and the residues flanking the RGD sequence, are key structural features for the functional activity of these molecules. Recently, our group reported a transcript in the venom gland of Bothrops neuwiedi corresponding to a new P-II SVMP precursor, BnMPIIx, in which the RGD-binding loop includes many substituted residues and unique cysteine residues at the C-terminal. In this paper, we obtained the recombinant disintegrin domain of BnMPIIx, Neuwiedin, which inhibited ADP-induced platelet aggregation, endothelial cell adhesion to fibrinogen and tube formation in Matrigel with no particular selectivity to αIIbß3 or endothelial cell integrins. This value was also comparable to the inhibition observed with other recombinant disintegrins with conserved cysteine positions and residues in RGD loop. In this regard, Neuwiedin is an important component to understand the functional relevance of the diversity generated by accelerated evolution of venom toxins as well as to find out eventual new disintegrin-dependent targets that may be approached with disintegrins.

Prevalence of occupational hazards in patients with different types of epithelial sinonasal cancers.

BACKGROUND: Occupational exposure to carcinogens contributes greatly to the etiology of sinonasal cancer (SNC), but the role of different risk factors in determining different histological subtypes is disputed. METHODOLOGY: All consecutive surgical epithelial SNC cases (case-series study) underwent a systematic occupational medicine examination to determine previous exposure to a wide range of work-related chemical hazards. RESULTS: We investigated 65 SNC cases including intestinal-type adenocarcinoma [ITAC] squamous-cell carcinoma [SCC], and others. Occupational exposure was recognized for 39 cases. Occupational exposures were sensibly more frequent among ITAC than among SCC or other histotypes. Occupational exposure in ITAC cases was to leather or wood dust only, while among non-ITAC cases, we recognised exposure to formaldehyde, solvents and metal fumes. A high proportion of SNC with occupational exposure originated in the ethmoidal epithelium. CONCLUSION: In our case-series of SNC, a very high frequency of previous occupational exposure to carcinogens was detected, suggesting that occupational hazards may be associated to the aetiopathogenesis, primarily for ITAC, but also for other histotypes. Besides leather or wood, other chemical agents must be recognized as occupational risk factors.

[Prospectic evaluation of the Italian Workers' Compensation Authority in a large case series of Occupational sino-nasal cancers]. / Studio prospettico sulla valutazione in sede INAIL di un'ampia sistica di TuNS professionali.

Sino-nasal cancer (SNC) are rare tumours with an elevated occupational etiological fraction, due both to well-established risk factors (wood and leather) and to more rare carcinogens. We evaluated the assessment for workers' compensation performed by the Italian Authority (INAL) in a case-series of occupational SNC (N = 45). We observed an elevated proportion of cases that were recognised as occupational, overall (36 on 39) and for any histotype. INAIL tended to recognize as professional not only patients with exposure to wood and leather but also cases with a documented exposure to formaldehyde, metal, polycyclic hydrocarbons. Significant differences across Italian macro-regions appeared, when the amount of worker compensation was investigated.

Crotoxin is responsible for the long-lasting anti-inflammatory effect of Crotalus durissus terrificus snake venom: involvement of formyl peptide receptors

In the present study, it was investigated which components are responsible for the antiinflammatory properties of Crotalus durissus terrificus venom (CdtV). The effect of crotoxin,as well as of other CdtV components was evaluated on edema, cell migration and alterations in leukocyte–endothelium interactions induced by carrageenan. Crotoxin (40 mg kg 1) was injected at different time periods before or after the injection of carrageenan (15 mg kg 1)into the mouse hind paw, peritoneum or scrotum. Results showed that crotoxin, but not other CdtV components, significantly inhibited inflammatory edema and cell migration when administered before or after carrageenan injection in mice. This toxin also prevented the occurrence of alterations in leukocyte–endothelium interactions induced by carrageenaninjection, such as the increase in adhered cells. In animals pretreated with Boc2 (a selective antagonist of formyl peptide receptors), crotoxin showed neither inhibitoryeffects on edema and cell migration, nor prevented alterations in leukocyte–endothelium interactions induced by carrageenan. These findings demonstrate that crotoxin is thecomponent responsible for the long-lasting anti-inflammatory activity of crude C. durissus terrificus venom, and activation of formyl peptide receptors seems to play a major role inthis effect.

Crotoxin is responsible for the long-lasting anti-inflammatory effect of Crotalus durissus terrificus snake venom: involvement of formyl peptide receptors.

In the present study, it was investigated which components are responsible for the anti-inflammatory properties of Crotalus durissus terrificus venom (CdtV). The effect of crotoxin, as well as of other CdtV components was evaluated on edema, cell migration and alterations in leukocyte-endothelium interactions induced by carrageenan. Crotoxin (40 microg kg(-1)) was injected at different time periods before or after the injection of carrageenan (15 mg kg(-1)) into the mouse hind paw, peritoneum or scrotum. Results showed that crotoxin, but not other CdtV components, significantly inhibited inflammatory edema and cell migration when administered before or after carrageenan injection in mice. This toxin also prevented the occurrence of alterations in leukocyte-endothelium interactions induced by carrageenan injection, such as the increase in adhered cells. In animals pretreated with Boc2 (a selective antagonist of formyl peptide receptors), crotoxin showed neither inhibitory effects on edema and cell migration, nor prevented alterations in leukocyte-endothelium interactions induced by carrageenan. These findings demonstrate that crotoxin is the component responsible for the long-lasting anti-inflammatory activity of crude C. durissus terrificus venom, and activation of formyl peptide receptors seems to play a major role in this effect.

Pastas de hidróxido de calcio preparadas con diferente soluciones. Acción solvente / Calcium hydroxide pastes mixed with different wehicles. Solvent action

Una de las sustancias más utlizadas para la desinfección de los conductos radiculares es el hidróxido de calcio. Es un polvo fuertemente alcalino que puede ser mezclado con difrentes vehículos y usado como pasta de obturación intermedia. Se han propuesto diferentes vehículos para formar la pasta de hidróxido de calcio, tales como agua destilada, solución fisiológica, anestesia, propilenglicol, paramonoclorofenol alcanforado entre otros. Estudios recientes han sugerido combinar el polvo del Ca (OH)2 con soluciones de irrigación par amejorar su acción solvente sobre el tejido pulpar y antibacteriana especialmente frete al E. faecalis y Candida albicans que mosraron ser resistentes a las pastas tradicionales. Objetivo: En este trabajo se comparó la acción solvente sobre el tejido pulpar bovino de diferentes pasats de hidroxido de calcio. Material y Métodos: Se usarón pulpas bovinas extraídas de animales jóvenes sobre las que se evaluó la acción de pastas de hidróxido de calcio con hipoclorito de sodio 1% hidróxido de calcio con gluconato de clorhexidina 1%, hidróxido de calcio con solución fisiológica, hasta 21 días. Se evaluó la capacidad de disulación del del tejido pulpar de estas pastas, usando como teztigo los vehículo mendionados. Los datos se analizaron estadísticamente con el test de Kruskal Wallis. Resultados y Conclusiones: Las tres pastas de hidróxdo de calcio se comportaron en forma semejante, con respecto a su acción solvente (AU)

Calcium hydroxide is frequently used as an atiseptic agent of root canals. It is ana alcaline powder and can be mixed with differente vehices to be used as an ntracanal medication. Astes can be developed using distilled water, CI NA 0,7% solution, anesthetics solutions, propylene glycol, camphorated paramonochloreophenol among others. Recent studies suggest using Ca (OH)2 with irrigating solutions to get a paste with better sovent and antibacerial action on pulpar tissue, specially against E. faecalis and Candida albicans. Objective: Comparison of solvent action of different calcium fydroxide pastes on bovine pulpar tissue is the main objectie of our study. Materials and Method.: We have used young boine pulpes and pastes of Ca (OH)2 with 1% sodium hypochlorite, with 1% chlorhexidine gluconate, with 0,7% Cl Na during 21 days. We evaluted disolution o pulpar tissue and each vhicle was our control group. Data was statisically analized using Kruskal Wallis test. Results and concluissions: All three calcium hdroxide pastes had similar solvent action (AU)

Collagen binding is a key factor for the hemorrhagic activity of snake venom metalloproteinases.

Snake venom metalloproteinases (SVMPs) are multifunctional enzymes involved in several symptoms following snakebite, such as severe local hemorrhage. Multidomain P-III SVMPs are strongly hemorrhagic, whereas single domain P-I SVMPs are not. This indicates that disintegrin-like and cysteine-rich domains allocate motifs that enable catalytic degradation of ECM components leading to disruption of capillary vessels. Interestingly, some P-III SVMPs are completely devoid of hemorrhagic activity despite their highly conserved disintegrin-like and cysteine-rich domains. This observation was approached in the present study by comparing the effects of jararhagin, a hemorrhagic P-III SVMP, and berythractivase, a pro-coagulant and non-hemorrhagic P-III SVMP. Both toxins inhibited collagen-induced platelet aggregation, but only jararhagin was able to bind to collagen I with high affinity. The monoclonal antibody MAJar 3, that neutralizes the hemorrhagic effect of Bothrops venoms and jararhagin binding to collagen, did not react with berythractivase. The three-dimensional structures of jararhagin and berythractivase were compared to explain the differential binding to collagen and MAJar 3. Thereby, we pinpointed a motif within the Da disintegrin subdomain located opposite to the catalytic domain. Jararhagin binds to both collagen I and IV in a triple helix-dependent manner and inhibited in vitro fibrillogenesis. The jararhagin-collagen complex retained the catalytic activity of the toxin as observed by hydrolysis of fibrin. Thus, we suggest that binding of hemorrhagic SVMPs to collagens I and IV occurs through a motif located in the Da subdomain. This allows accumulation of toxin molecules at the site of injection, close to capillary vessels, where their catalytic activity leads to a local hemorrhage. Toxins devoid of this motif would be more available for vascular internalization leading to systemic pro-coagulant effects. This reveals a novel function of the disintegrin domain in hemorrhage formation.

BnP1, a novel P-I metalloproteinase from Bothrops neuwiedi venom: biological effects benchmarking relatively to jararhagin, a P-III SVMP.

Snake venom metalloproteinases (SVMPs) have been extensively studied and their effects associated with the local bleeding observed in human accidents by viper snakes. Representatives of P-I and P-III classes of SVMPs similarly hydrolyze extracellular matrix proteins or coagulation factors while only P-III SVMPs induce significant hemorrhage in experimental models. In this work, the effects of P-I and P-III SVMPs on plasma proteins and cultures of muscle and endothelial cells were compared in order to enlighten the mechanisms involved in venom-induced hemorrhage. To reach this comparison, BnP1 was isolated from B. neuwiedi venom and used as a weakly hemorrhagic P-I SVMPs and jararhagin was used as a model of potently hemorrhagic P-III SVMP. BnP1 was isolated by size exclusion and anion-exchange chromatographies, showing apparent molecular mass of approximately 24kDa and sequence similarity with other members of SVMPs, which allowed its classification as a group P-I SVMP. The comparison of local effects induced by SVMPs showed that BnP1 was devoid of significant myotoxic and hemorrhagic activities and jararhagin presented only hemorrhagic activity. BnP1 and jararhagin were able to hydrolyze fibrinogen and fibrin, although the latter displayed higher activity in both systems. Using HUVEC primary cultures, we observed that BnP1 induced cell detachment and a decrease in the number of viable endothelial cells in levels comparable to those observed by treatment with jararhagin. Moreover, both BnP1 and jararhagin induced apoptosis in HUVECs while only a small increase in LDH supernatant levels was observed after treatment with jararhagin, suggesting that the major mechanism involved in endothelial cell death is apoptosis. Jararhagin and BnP1 induced little effects on C2C12 muscle cell cultures, characterized by a partial detachment 24h after treatment and a mild necrotic effect as evidenced by a small increase in the supernatants LDH levels. Taken together, our data show that P-I and P-III SVMPs presented comparable effects except for the hemorrhagic activity, suggesting that hydrolysis of coagulation factors or damage to endothelial cells are not sufficient for induction of local bleeding.

Prognostic value of differential expression of Laminin-5 gamma2 in oral squamous cell carcinomas: correlation with survival.

In oral squamous cell carcinomas of the head and neck, Laminin-5 gamma2 has been associated with tissue invasion, lymph node metastasis and histopathological grading. In the present study, we compared the expression of the subunit gamma2 of Laminin-5 under normal, dysplastic and invading epithelia in 65 biopsies previously diagnosed for oral squamous cell carcinoma. The number of gamma2-positive cells were analyzed in relation to patients' survival, tumor grading, size of the lesion, TNM stage, histopathological pattern of invasion and inflammatory reaction. Biopsies of oral squamous cell carcinomas were deparaffinised, processed for antigen unmasking procedures and stained with antibody anti-Laminin-5 gamma2. By light microscopy, 4 optical fields of x200 were selected in three different areas including normal, dysplastic and invading epithelia. Positive cells were counted and divided into three categories, which included <20 cells, between 21 and 50 cells and >50 stained cells. Patient survival was analyzed by Kaplan-Mayer curves. gamma2-positive cells were found in the basal layer of dysplastic epithelium, within inflammatory infiltrate, at the margins of differentiated invading islands and at the forefront of undifferentiated invading nests. Observations showed that an increased number of gamma2-positive cells correlated significantly with a shorter life expectancy under invading epithelia (log-rank test p<0.05), not when a count was performed under normal or dysplastic epithelia of the same patient. The number of gamma2-positive cells also correlated with the histopathological pattern of invasion. Our results show that gamma2 may be a reliable prognostic tool for oral squamous cell carcinomas.

Patterns of phase-dependent spiral wave attenuation in excitable media.

We show that introducing periodic planar fronts with long excitation duration can lead to spiral attenuation. The attenuation occurs periodically over cycles of several planar fronts, forming a variety of complex spatiotemporal patterns. We find that these attenuation patterns occur only at specific phases of the descending fronts relative to the rotational phase of the spiral. These patterns fall into two general classes, each defined by a specific expression for the number of attenuated spirals per cycle of planar fronts, and represented by a structured diagram in parameter space. The spiral attenuation patterns we observe remain stable in time and do not change during the evolution of the system.