Shear controlled crystal size definition in a low molar mass compound using a polymeric solvent

We show that close to monodisperse crystalline fibrils of dibenzylidene sorbitol can be obtained by preparation in a polymeric solvent subjected to extended shear flow.

Effects of Cobalt Chloride in Junctional Epithelium and Reduced Enamel Epithelium of the Rat Maxillary First Molar

Cobalt is one of the main components of cast metal alloys broadly used in dentistry. It is the constituent of 45 to 70% of numerous prosthetic works. There are evidences that metal elements cause systemic and local toxicity. The purpose of the present study was to evaluate the effects of cobalt on the junctional epithelium and reduced enamel epithelium of the first superior molar in rats, during lactation. To do this, 1-day old rats were used, whose mothers received 300mg of cobalt chloride per liter of distilled water in the drinker, during lactation. After 21 days, the rat pups were killed with an anesthetic overdose. The heads were separated, fixed in ""alfac"", decalcified and embedded in paraffin. Frontal sections stained with hematoxylin and eosin were employed. Karyometric methods allowed to estimate the following parameters: biggest, smallest and mean diameters, D/d ratio, perimeter, area, volume, volume/area ratio, eccentricity, form coefficient and contour index. Stereologic methods allow to evaluate: cytoplasm/nucleus ratio, cell and cytoplasm volume, cell number density, external surface/basal membrane ratio, thickness of the epithelial layers and surface density. All the collected data were subjected to statistic analysis by the non-parametric Wilcoxon-Mann-Whitney test. The nuclei of the studied tissues showed smaller values after karyometry for: diameters; perimeter, area, volume and volume/area ratio. Stereologically, it was observed, in the junctional epithelium and in the reduced enamel epithelium, smaller cells with scarce cytoplasm, reflected in the greater number of cells per mm3 of tissue. In this study, cobalt caused epithelial atrophy, indicating a direct action on the junctional and enamel epithelium.

Blendas de polietileno de ultra alto peso molar (PEUAPM) com polietileno linear de média densidade (PELMD) para rotomoldagem

Neste trabalho foi feito um estudo das propriedades reológicas, mecânicas e térmicas de blendas poliméricas contendo 1 e 10% em massa de polietileno de ultra alto peso molar (PEUAPM) e polietileno linear de média densidade (PELMD). As blendas foram obtidas por mistura em extrusora de rosca simples e em extrusora de rosca dupla, para fins de comparação. Na extrusão em rosca dupla foi acrescentado um terceiro componente - óleo mineral, cera ou polietileno de muito baixo peso Molar (PEMBPM) - a fim de promover uma melhor interação entre o PELMD e PEUAPM. As amostras obtidas por moldagem por injeção, rotomoldagem e moldagem por compressão foram submetidas a testes reológicos, térmicos e mecânicos. Foi analisada a influência do tipo de processamento e da composição das blendas sobre morfologia e as propriedades finais destas. A reometria rotacional indicou um gradual aumento da viscosidade das blendas com o aumento da quantidade de PEUAPM adicionado. Análises de microscopia eletrônica de varredura (MEV), microscopia ótica e calorimetria diferencial de varredura (DSC) indicaram uma separação de fases nas blendas, mesmo quando o terceiro componente foi adicionado. Entretanto, as blendas que contém agente de acoplamento apresentaram diferenças na morfologia final, como observado através das análises de microscopia ótica durante a cristalização do sistema polimérico e nas análises de MEV nas amostras moldadas por injeção Para todas as blendas moldadas por injeção, a resistência ao impacto foi menor do que a encontrada para o PELMD puro. Por outro lado, nas amostras rotomoldadas não houve diferença significativa nas propriedades das blendas quando comparadas ao PELMD puro. As amostras extrusadas em rosca dupla, contendo óleo mineral ou cera e, posteriormente, moldadas por compressão apresentaram resistência ao impacto similares aos valores encontrados para o PELMD puro, sem significativas mudanças na processabilidade. Considerando as demais análises de propriedades mecânicas, não foi observada influência do terceiro componente.

Influência da densidade de carga e da massa molar da poliacrilamida na reologia de sistemas microemulsionados

The knowledge of the rheological behavior of microemulsionated systems (SME) is of fundamental importance due to the diversity of industrial applications of these systems. This dissertation presents the rheological behavior of the microemulsionated system formed by RNX 95/alcohol isopropyl/p-toulen sodium sulfonate/kerosene/distilled water with the addition of polyacrylamide polymer. It was chosen three polymers of the polyacrylamide type, which differ in molar weight and charge density. It was studied the addition of these polymers in relatively small concentration 0,1% in mass and maximum concentration of 2,0%. It was made analysis of flow to determine the appearing viscosities of the SME and rheological parameters applying Bingham, Ostwald de Waale and Herschell-Buckley models. The behavior into saline environment of this system was studied for a solution of KCl 2,0%, replacing the distilled water. It was determined the behavior of microemulsions in relation with the temperature through curves of flow in temperatures of 25 to 60ºC in variations of 5ºC. After the analysis of the results the microemulsion without the addition of polymer presented a slight increase in its viscosity, but it does not mischaracterize it as a Newtonian fluid. However the additive systems when analyzed with low concentration of polymer adjusted well to the applied models, with a very close behavior of microemulsion. The higher concentration of the polymer gave the systems a behavior of plastic fluid. The results of the temperature variation point to an increase of viscosity in the systems that can be related to structural changes in the micelles formed in the own microemulsion without the addition of polymer

Double muscle innervation using end-to-side neurorrhaphy in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A curva de regressão da gonadotrofina coriônica humana é útil no diagnóstico precoce da neoplasia trofoblástica gestacional pós-molar?

OBJETIVO: avaliar a utilidade da curva de regressão normal da gonadotrofina coriônica humana (hCG) no diagnóstico precoce de neoplasia trofoblástica gestacional pós-molar (NTG). MÉTODOS: estudo longitudinal, incluindo 105 pacientes com mola hidatiforme completa (MHC) acompanhadas no Centro de Doenças Trofoblásticas de Botucatu, entre 1998 e 2005. Os títulos da hCG sérica foram mensurados quinzenalmente em todas as pacientes. Curvas individuais de regressão da hCG das 105 pacientes foram estabelecidas. A comparação entre a curva de regressão normal estabelecida em nosso serviço com as curvas individuais da hCG foi usada no rastreamento e diagnóstico (platô/ascensão) de NTG. O número de semanas pós-esvaziamento quando a hCG excedeu o limite normal foi comparado com o número semanas em que a hCG apresentou platô/ascensão. RESULTADOS: das 105 pacientes com MHC, 80 apresentaram remissão espontânea (RE) e 25 desenvolveram NTG. Das 80 pacientes com RE, 7 (8,7%) apresentaram, inicialmente, dosagem da hCG acima do normal, mas, no devido tempo, alcançaram a remissão. Todas as 25 pacientes com NTG apresentaram desvio da curva normal da hCG em 3,8±2,5 semanas e mostraram platô ou ascensão em 8,4±2,9 semanas (p<0,001). CONCLUSÕES: a curva de regressão normal da hCG pós-molar pode ser útil para diagnóstico de NTG.

Molar Pregnancy in Adolescents

OBJECTIVE: To describe the clinical presentation of hydatidiform molar pregnancy in women under the age of 20 years. In addition, we sought to understand if this adolescent population manifests differences in clinical factors compared to an adult population that may affect outcome.STUDY DESIGN: We used a database from the New England Trophoblastic Disease Center to analyze clinical data from all women followed for molar pregnancy between 1970 and 2009 with complete follow-up information. This population was stratified by age and clinical parameters including presenting signs, molar histology and development of gestational trophoblastic neoplasia (GTN). Univariable and multivariable logistic regression was employed to discern clinical factors that associated with adolescent age. The Partners Human Research Committee approved this study.RESULTS: We identified 1,494 women diagnosed with hydatidiform mole (HM), of which 220 (14.7%) were adolescents defined as age <20 years. The most common presenting clinical signs were vaginal bleeding and an enlarged uterus compared to dates. Median gestational age at diagnosis was 13.4 weeks, not different from that in the adult population. Similarly, no difference in presenting human chorionic gonadotropin was observed between the adult and adolescent populations. Adolescents presented with a significant overrepresentation of complete mole (86% vs. 75%, p < 0.001) compared to adults. Complete mole was associated with a heightened risk of developing GTN (OR 2.6, 95% CI 1.9-3.5), and despite the association of complete mole with young maternal age, univariable analysis showed no difference in the rate of GTN observed between adolescents and adults (24% vs. 30%, p = 0.08). Multivariable analysis controlling for molar histology demonstrated that adolescent age was associated with a decreased risk of GTN (hazard ratio 0.67, 95% CI 0.48 0.93).CONCLUSION: Adolescents account for a substantial proportion of the population with HM. They commonly present with vaginal bleeding. Though this population develops a complete mole with a higher frequency than adults, adolescents appear to have a significantly decreased risk of developing GTN. (J Reprod Med 2012; 57:225-230)

Gestational Trophoblastic Neoplasia Following Molar Ectopic Pregnancy A Case Report

BACKGROUND: Ectopic molar pregnancy is a gestational trophoblastic disease (GTD) of rare occurrence and therefore not always remembered as a diagnostic possibility.CASE: We describe a case of molar ectopic pregnancy in a primiparous woman who developed gestational trophoblastic neoplasia and required chemotherapy to achieve remission.CONCLUSION This case stresses the important role of histopathologic examination in establishing a diagnosis of ectopic molar pregnancy. Moreover, close follow-up of human chorionic gonadotropin levels is required when a GTD is suspected. (J Reprod Med 2008;53:579-582)

Origin of sensory and autonomic innervation of the rat temporomandibular joint: A retrograde axonal tracing study with the fluorescent dye fast blue

Previous studies that have used retrograde axonal tracers (horseradish peroxidase alone or conjugated with wheat germ agglutinin) have shown that the temporomandibular joint (TMJ) is supplied with nerve fibers originating mainly from the trigeminal ganglion, in addition to other sensory and sympathetic ganglia. The existence of nerve fibers in the TMJ originating from the trigeminal mesencephalic nucleus is unclear, and the possible innervation by parasympathetic nerve fibers has not been determined. In the present work, the retrograde axonal tracer, fast blue, was used to elucidate these questions and re-evaluated the literature data. The tracer was deposited in the supradiscal articular space of the rat TMJ, and an extensive morphometric analysis was performed of the labeled perikaryal profiles located in sensory and autonomic ganglia. This methodology permitted us to observe labeled small perikaryal profiles in the trigeminal ganglion, clustered mainly in the posterior-lateral region of the dorsal, medial and ventral thirds of horizontal sections, with some located in the anterior-lateral region of the ventral third. Sensory perikarya were also labeled in the dorsal root ganglia from C2 to C5. No labeled perikaryal profiles were found in the trigeminal mesencephalic nucleus. on the other hand, autonomic labeled perikaryal profiles were distributed in the sympathetic superior cervical and stellate ganglia, and parasympathetic otic ganglion. Our results confirmed those of previous studies and also demonstrated that: (i) there is a distribution pattern of labeled perikaryal profiles in the trigeminal ganglion; (ii) some perikaryal profiles located in the otic ganglion were labeled; and (iii) the trigeminal mesencephalic nucleus did not show any retrogradely labeled perikaryal profiles.

Comparative Analysis of 2-Flap Designs for Extraction of Mandibular Third Molar

Objective: The objective of the study was to analyze 2-flap designs for surgical extraction of third molar, evaluating the periodontal status of the second lower molar.Study Design: Forty-five lower third molars were extracted from 24 patients. In 23 teeth, a vertical incision to the mandibular ramus was used (technique A), whereas 22 teeth were submitted to classic L-shaped flap (technique B) with controls at 60 and 90 days postoperatively.Results: Pearson correlation coefficient analysis showed a significant correlation only between immediate preoperative probing depth variables from techniques A and B in the studied surfaces. Statistical significances in the preoperative (vestibular) and postoperative day 60 (distovestibular and vestibular) were noted. In contrast, Student t-test showed no statistical difference in probing depths between preoperative and postoperative values, as well as no statistically significant difference regarding the type of incision alone.Conclusions: Technique A allowed a less traumatic surgery, guaranteeing a more comfortable postoperative period.