Occlusal caries detection on 3D models obtained with an intraoral scanner. A validation study.

OBJECTIVES: To evaluate the diagnostic performance of visual caries assessment on 3D dental models obtained using an intraoral scanner and to compare it with the performance of the clinical visual inspection. METHODS: Fifty-three permanent posterior teeth scheduled for extraction were randomly selected and included in this study. One to three independent examination sites on the occlusal surface of each tooth were clinically inspected using International Caries Detection and Assessment System (ICDAS) criteria. Afterwards, the examined teeth were scanned intraorally with a 3D intraoral scanner (TRIOS 4, 3Shape TRIOS A/S, Copenhagen, Denmark) using white and blue-violet light (415 nm wavelength) to capture the colour and fluorescence signal from the tissues. Six months after the clinical examination, the same examiner conducted the on-screen assessment of the obtained 3D digital dental models at the selected examination sites using modified ICDAS criteria. Both tooth colour and fluorescence texture with high resolution were assessed. Lastly, an independent examiner conducted the histological examination of all teeth after extraction. Using histology as the reference test, Sensitivity (SE), Specificity (SP), Accuracy (ACC), area under the Receiver Operating Characteristic (ROC) curve, and Spearman's correlation coefficient were calculated for the clinical and on-screen ICDAS assessments. RESULTS: The ACC values of the evaluated methods varied between 0.59-0.79 for initial caries lesions and 0.77-0.99 for moderate-extensive caries lesions. Apart from SE values corresponding to caries in the inner half of enamel, no significant difference was observed between clinical visual inspection and on-screen assessment. In addition, no difference was found in the assessment of 3D models with tooth colour alone or supplemented with fluorescence for all the evaluated diagnostic measures. CONCLUSIONS: On-screen visual assessment of 3D digital dental models with tooth colour or fluorescence showed a similar diagnostic performance to the clinical visual inspection when detecting and classifying occlusal caries lesions on permanent teeth. CLINICAL SIGNIFICANCE: 3D intraoral scanning can aid the detection and classification of occlusal caries as part of patient screening and can potentially be used in remote caries assessment for clinical and research purposes.

Echocardiographic changes in anorexia nervosa: a pathophysiological adaptation or a disease?

Anorexia Nervosa is one of the most common form of eating disorders. Cardiac involvement occurs in approximately 80% of patients. Few reports focused on the association between body weight fluctuations and echocardiographic abnormalities, considering linear measurements. We describe echocardiographic and clinical features among male and female patients with anorexia nervosa and the effect of weight gain on these parameters. We performed a single center, retrospective study of patients followed at a dedicated multidisciplinary Unit. The study population consisted of 81 patients, mean age 25 ± 11 years, 94% female. Median body mass index was 14.4 kg/m2 (25th-75th percentile 12.7-15.6 kg/m2). Patients with body mass index below the median value had more often pericardial effusion, smaller left ventricular mass and left ventricular end-diastolic volume and thinner interventricular septum. However, when indexed to body surface area, left ventricular mass and volumes were within the normal range in 90% of population. Patients with pericardial effusion showed mitral valve abnormalities and lower values of white blood cells and platelets, although within normal limits. Presence of pericardial effusion was not related to inflammatory parameters or low plasma protein levels. In 39 patients who displayed weight gain during a median follow-up of 189 days (25th-75th percentile 47-471), increased left ventricular mass, interventricular septum thickness, white blood cells and platelet count and decreased pericardial effusion were observed. Patients with anorexia nervosa have a specific echocardiographic pattern which seems to be proportional to the body size, suggesting a pathophysiological adaptation to the lack of substrates.

Probing Water Mobility in Human Dentine with Neutron Spectroscopy.

The aim of this study was to investigate hydrogen mobility within innate and demineralized human dentine. Dentine sections from extracted human molars, demineralized or not, were analyzed by combining neutron spectroscopy with thermal analysis. For the thermal analysis of the samples, differential scanning calorimetry and thermal gravimetric analysis, coupled with Fourier transform infrared spectroscopy, were performed. The hydrogen dynamics of water, collagen, and hydroxyl groups present in the samples were investigated via neutron spectroscopy. From the mass loss observed from the thermogravimetric analysis curves up to 600 °C, the same amount of organic content is identified in the samples. From the differential scanning calorimetry curves, a higher change in enthalpy associated with the denaturation of collagen is registered in the demineralized dentine; that is, a structural change occurs in the collagen subsequent to demineralization. Since the intensity measured by neutron spectroscopy is dominated by the signal from hydrogen, in our samples-coming mostly from the bulk-like and loosely bound water as well as from the collagen itself-higher proton mobility within the demineralized dentine was detected when compared with innate dentine. In the demineralized dentine, this proton mobility amounts to 80%, while the remaining hydrogen accounts for a combination of 1) structural hydroxyls, as a result of the incomplete dissolution of the mineral phase by acid etching, and 2) hydrogen tightly bound in the collagen structure. By combining neutron spectroscopy with the calorimetry data, our findings support the idea that hydroxyapatite protects the collagen in innate dentine. Demineralized dentine, however, acts as a sponge where free bulk-like water is trapped.

Oral health-related quality of life and complications after treatment with partial removable dental prosthesis.

The aims of this study were to measure and describe the oral health-related quality of life (OHRQoL) and to identify the complications caused by partial removable dental prosthesis (RDPs) in patients 1-5 years after treatment. Complications were identified in 65 patients who were treated with 83 RDPs (48 upper, 35 lower). OHRQoL was measured using the OHIP-49 before treatment and at the baseline (1-2 months after treatment) and follow-up (1-5 years after treatment) examinations. The types and numbers of oral problems that were experienced were described based on OHIP items with a score of 3 and 4. A significant improvement (P < 0·05) in the total OHIP-49 was registered from pre-treatment (mean 42, SD ± 37) to baseline (mean 29, SD ± 27) and from pre-treatment to 1-5 years after treatment (mean 32, SD ± 30). There was no significant difference between the baseline and 1- to 5-year follow-up examinations. Problems with eating and appearance registered at pre-treatment were improved at baseline and after 1-5 years. Problems with dentures that had been registered pre-treatment were improved at baseline but reoccurred after 1-5 years. The two most frequent complications were ill-fitting RDPs and inflammation of the oral mucosa, followed less frequently by fractures of the clasps. Treatment with RDPs improved OHRQoL, but denture-related problems partly remained, and new problems related to RDPs occurred 1-5 years after treatment. The two most frequent complications were ill-fitting RDPs and inflammation of the oral mucosa.

Bariatric surgery versus medications in the treatment of type 2 diabetes.

Type 2 diabetes mellitus (T2DM) is associated with increased risk of severe comorbidities and mortality; its prevalence is increasing worldwide, linked with the increasing prevalence of obesity. Weight loss prevents the development of T2DM in obese subjects, and can reverse T2DM in morbid obesity. This paper reviews bariatric surgery as a means for prevention and treatment of T2DM and its complications, in comparison with medical treatment, and analyzes the possible mechanisms involved. In morbidly obese patients bariatric surgery results in stable weight loss and long-term reduction in incidence and prevalence of obesity-related comorbidities, especially T2DM. The efficacy of bariatric surgery in improving and normalizing glucose levels has been confirmed by a large number of studies, comparing surgery with medical therapy. When compared to each other, malabsorptive and mixed malabsorptive/restrictive surgery techniques have shown better outcomes than restrictive techniques in terms of T2DM remission. However it is demonstrated that T2DM can reappear in the following years, especially in patients with advanced age, female sex, longer duration of T2DM, poorer glycemic control, use of insulin before surgery and weight regain. Bariatric surgery is superior to conventional medical therapy in inducing significant weight loss and control of T2DM. Weight loss has pleiotropic effects: T2DM can disappear and then re-appear as a result of persistent beta-cells impairment, while other effects last much longer, as reduction of blood pressure and improvement of lipids and of kidney function. This is probably the reason for long-term prevention of cardiovascular events and of mortality in obese and in obese-diabetic patients. The effect of bariatric surgery on diabetic retinopathy is still controversial.

Retention of Root Canal Posts: Effect of Cement Film Thickness, Luting Cement, and Post Pretreatment.

The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement, pretreatment with tribochemical silicate coating significantly increased retention of the posts. Increased cement film thickness resulted in decreased retention of untreated posts and of pretreated posts luted with zinc phosphate cement. Increased cement film thickness had no influence on retention of pretreated posts luted with resin cement. Thus, retention of the posts was influenced by the type of luting cement, by the cement film thickness, and by the post pretreatment.

Bulk-fill resin composites: polymerization contraction, depth of cure, and gap formation.

The bulk-filling of deep, wide dental cavities is faster and easier than traditional incremental restoration. However, the extent of cure at the bottom of the restoration should be carefully examined in combination with the polymerization contraction and gap formation that occur during the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk-fill materials produced a significantly larger depth of cure and polymerization contraction. Although most of the bulk-fill materials exhibited a gap formation similar to that of the conventional resin composite, two of the low-viscosity bulk-fill resin composites, x-tra base and Venus Bulk Fill, produced larger gaps.

Application of the urban water use model for urban water use management purposes.

The aim of this work is to present an application of the urban water use (UWU) model, which is a support decision tool to define the best group of efficient water use measures for UWU management purposes. Therefore, the UWU was developed under integrated urban water management (IUWM) and strategic planning principles to promote a systemic approach for decision taking. The IUWM considers the interfaces between water service systems, while by strategic planning it is possible to elaborate a vision to be achieved in future scenarios. Specifically to define the best measure group of efficient water use, the UWU has many alternatives for these measures, which are based on water demand management, decentralized sanitation, ecological sanitation and sustainable urban drainage system philosophies. In this context, the UWU application presented was developed for Seara city, Santa Catarina State, Brazil. In this application a vision and five scenarios were built. The measure groups were composed by greywater systems, filterstrips, water saving devices in buildings, and water loss reduction in water supply systems and wastewater treatment system. In this context the UWU model was applied. The measure group that presented the highest effectiveness was based on the water demand management and decentralized sanitation strategies.

CONTROL OF SOIL-BORNE DISEASES BY DIFFERENT COMPOSTS IN POTTED VEGETABLE CROPS.

The composting process and the type and nature of wastes and raw materials influence the maturity, quality and suppressiveness of composts. Variability in disease suppression also depends on the pathosystem, on soil or substrate type, on chemical-physical conditions, like pH and moisture, and on the microbial component of compost. The aim of the research was to evaluate the suppressiveness of composts, originated from green wastes and/or municipal biowastes, and produced by different composting plants located in Europe. The composts were tested against soil-borne pathogens in greenhouse on potted plants: Fusarium oxysporum f.sp. busilici/basil, Pythium ultimum/cucumber, Rhizoctonia solani/bean. Composts were blended with a peat substrate at different dosages (10, 20 and 50% vol./vol.) 14 days before seeding or transplanting. Pythium ultimum and Rhizoctonia solani were mixed into the substrate at 0.5 g of wheat kernels L(-1) 7 days before seeding, while, in the case of Fusarium oxysporum f.sp. basilici, chlamydospores were applied at 1 x 10(4) CFU/g. Seeds of basil, cucumber and bean were sown into 2 L pots in greenhouse. The number of alive plants was counted and above ground biomass was weighed 30 days after seeding. The number of infected cucumber and basil plants was significantly reduced by increasing dosages of composts, but municipal compost was phytotoxic when applied at high dosages compared to green compost. Moreover, municipal compost increased the disease caused by Rhizoctonia solani on bean. The use of compost in substrates can be a suitable strategy for controlling soil-borne diseases on vegetable crops, but results depend on type of composts, application rates and pathosystems.

Other aspects of bariatric surgery: liver steatosis, ferritin and cholesterol metabolism.

Bariatric surgery developed in the late 1970 to treat severe hyperlipidemias in overweight individuals, not necessarily obese. Several techniques have been developed, and the concept has come first of a surgery for morbid obesity, then of a cure for diabetes in morbid obesity. There are other aspects of bariatric surgery that deserve attention, beyond BMI and diabetes, such as hypertension, poor life expectancy, increased prevalence of cancer, congestive heart failure, social inadequacy. The aim of this presentation is to review some recent development in clinical research, in the fields of liver steatosis, ferritin metabolism, and cholesterol metabolism. Liver steatosis, also called fatty liver encompasses a graduation of diseases with different clinical relevance and prognosis. NAFLD correlates with atherosclerosis, insulin resistance and diabetes mellitus. There is now evidence that weight loss, obtained through diet or restrictive surgery, reduces the prevalence (and the severity) of NAFLD. An other issue is represented by serum ferritin concentrations, that are strongly associated with fibrosis, portal and lobular inflammation in NAFLD patients, especially in the presence of obesity. Body iron contributes to excess oxidative stress already at non iron overload concentrations. Moreover, serum ferritin is an important and independent predictor of the development of diabetes. Weight loss is accompanied by reduction of ferritin, more after restrictive than malabsorptive surgery. Metabolic changes are greater after malabsorptive or mixed surgery than after purely restrictive surgery, and this has been ascribed to a greater weight loss. Studies comparing the two kinds of surgery indicate that, for the same amount of weight loss, decrease of cholesterol is greater with the former than with the latter techniques, and this difference is mainly due to a greater reduction of intestinal absorption of cholesterol. In the choice of surgery for the single patient, among other aspects, malabsorptive surgery seems to be more indicated in subjects with hyperlipidemia, especially with high cholesterol levels.

La cirugía bariátrica se desarrolló a finales de la década de los 70 para tratar la hiperlipidemia severa en personas con sobrepeso, no necesariamente obesos. A lo largo de los años se han desarrollado varias técnicas quirúrgicas que han sido utilizadas en primer lugar en la obesidad mórbida y posteriormente en el tratamiento de la diabetes. Hay otros aspectos de la cirugía bariátrica que merecen atención más allá del IMC y la diabetes, como la hipertensión, la pobre esperanza de vida, una mayor prevalencia de cáncer, insuficiencia cardíaca e inadaptación social. El objetivo de este artículo es revisar los recientes avances clínicos en campos de investigación relacionados con la esteatosis hepática, el metabolismo de ferritina y el metabolismo del colesterol. La esteatosis hepática, también llamada hígado graso abarca una serie de las enfermedades con diferente pronóstico y relevancia clínica. El Hígado Graso No Alcohólico (NAFLD siglas en ingles) se correlaciona con la aterosclerosis, resistencia a la insulina y diabetes mellitus. Hoy en día existen evidencias de que la pérdida de peso que se obtiene a través de la dieta o cirugía restrictiva, reduce la prevalencia (y la gravedad) de la NAFLD. Otro tema de estudio incluye las concentraciones de ferritina sérica, que están fuertemente asociadas con la fibrosis e inflamación lobular y portal en pacientes con NAFLD, especialmente en presencia de obesidad. El exceso de hierro corporal en obesos contribuye a un aumento del estrés oxidativo debido a una sobrecarga en su concentración. Por otra parte, la ferritina sérica es un indicador importante e independiente del desarrollo de la diabetes. La pérdida de peso se acompaña de una disminución de la ferritina. Esta disminución es más evidente tras una cirugía restrictiva que tras una malabsortiva. Los cambios metabólicos son mayores después de una cirugía malabsortiva o mixta que tras una cirugía puramente restrictiva, y esto se ha atribuido a una mayor pérdida de peso. Estudios que comparan los dos tipos de cirugía indican que, para la mismo índice de pérdida de peso, la disminución de colesterol es mayor con las primeras técnicas que con las últimas, y esta diferencia se debe principalmente a una mayor reducción de la absorción intestinal del colesterol. En la elección de la cirugía para un paciente concreto, entre otros aspectos, la cirugía de malabsorción parece estar más indicada en sujetos con hiperlipemia, especialmente con altos niveles de colesterol.

Cuspal deflection and microleakage in premolar teeth restored with bulk-fill flowable resin-based composite base materials.

OBJECTIVES: To assess the cuspal deflection and cervical microleakage of standardised Class II cavities incrementally filled with a dimethacrylate RBC or bulk-fill flowable RBC bases. METHODS: Twenty-four sound upper premolar teeth with Class II cavities were allocated to three groups (n=8). Restoration of the teeth involved the placement of an RBC (GrandioSO) in eight oblique increments (Group A) or Groups B and C were restored to within 2 mm of the palatal cusp in a single increment with bulk-fill flowable RBC bases (SDR and x-tra base) before the two occlusal cavity increments were placed with GrandioSO. Buccal and palatal cusp deflections were recorded postirradiation using a twin channel deflection measuring gauge. Following restoration, the teeth were thermocycled, immersed in 0.2% basic fuchsin dye for 24h, sectioned and examined for cervical microleakage. RESULTS: The mean total cuspal deflection for the oblique incremental restoration technique was 11.26 (2.56) µm (Group A) and 4.63 (1.19) µm (Group B) and 4.73 (0.99) µm (Group C) for the bulk-fill flowable RBC bases. A significant increase in the mean total cuspal deflection for the incrementally filled GrandioSO compared with the SDR (P=0.007) and x-tra base (P=0.005) restored teeth was evident. No significant difference in the cervical microleakage scores was recorded between groups AC (P>0.05). CONCLUSIONS: The bulk-fill flowable RBC bases significantly reduced cuspal deflection compared with a conventional RBC restored in an oblique incremental filling technique with no associated change in cervical microleakage recorded.

Sequential analysis of multistage hepatocarcinogenesis reveals that miR-100 and PLK1 dysregulation is an early event maintained along tumor progression.

MicroRNAs (miRNAs) have an important role in a wide range of physiological and pathological processes, and their dysregulation has been reported to affect the development and progression of cancers, including hepatocellular carcinoma (HCC). However, in the plethora of dysregulated miRNAs, it is largely unknown which of them have a causative role in the hepatocarcinogenic process. In the present study, we first aimed to determine changes in the expression profile of miRNAs in human HCCs and to compare them with liver tumors generated in a rat model of chemically induced HCC. We found that members of the miR-100 family (miR-100, miR-99a) were downregulated in human HCCs; a similar downregulation was also observed in rat HCCs. Their reduction was paralleled by an increased expression of polo like kinase 1 (PLK1), a target of these miRNAs. The introduction of miR-100 in HCC cells impaired their growth ability and their capability to form colonies in soft agar. Next, we aimed at investigating, in the same animal model, if dysregulation of miR-100 and PLK1 is an early or late event along the multistep process of hepatocarcinogenesis. The obtained results showed that miR-100 downregulation (i) is already evident in very early preneoplastic lesions generated 9 weeks after carcinogenic treatment; (ii) is also observed in adenomas and early HCCs; and (iii) is not simply a marker of proliferating hepatocytes. To our knowledge, this is the first work unveiling the role of a miRNA family along HCC progression.

Prevalence of anti-Toxoplasma gondii antibodies in dairy cattle, dogs, and humans from the Jauru micro-region, Mato Grosso state, Brazil.

In order to determine the prevalence of anti-Toxoplasma gondii antibodies, 2000 serum samples from female dairy cattle belonging to 50 farms in the southwest of Mato Grosso state were analyzed by the indirect fluorescent antibody test (IFAT> or =64). Serum samples from 61 dogs (IFAT> or =40) and 116 humans (IFAT=40), all from the same farm, were also tested. Among these samples, 1420 (71.0%) cattle, 54 (88.5%) dogs, and 113 (97.4%) humans were seropositive for the infection. No significant differences (P> or =0.05) were observed for risk factors associated with the occurrence of toxoplasmosis in humans due to contaminated sources such as fresh milk, cheese/sausage, and contact with felines or other animals. The presence of felines can indicate the likelihood of a contaminated environment, posing a risk to the human population and other animals. The work presented herein is the first report to evaluate the seroprevalence of T. gondii in bovines from the Southwest region of the Mato Grosso state, Brazil.

Acute liver and renal failure during treatment with buprenorphine at therapeutic dose.

Buprenorphine is a semi-synthetic opioid derivative commonly used in the treatment of heroin addiction. Life-threatening complications have been described following overdoses while few cases of hepatotoxicity due to drug use at therapeutic doses have been recently described in hepatitis C virus carriers. In these cases, however, histological assessment was not exhaustive and no extra-hepatic organ failure was observed. We describe herein a case of acute liver and kidney failure in a patient with previously latent hepatitis C virus chronic infection following recommended doses of buprenorphine. Histology did not demonstrate any feature compatible with hepatitis C virus reactivation or liver cirrhosis and suspension of the treatment led to the resolution of both liver and kidney failure. Causality criteria fulfillment indicates a high probability of buprenorphine-induced liver toxicity. No signs of pre-existant kidney impairment or of pre- or post-renal causes were observed. Since buprenorphine is metabolized through cytochrome P450 3A4, we genotyped six genetic polymorphisms previously described in poor metabolizers but could not confirm these pharmacogenetic bases in this case. In conclusion, we surmise that buprenorphine at suggested doses can induce liver and kidney failure in susceptible individuals, possibly through direct mitochondrial toxicity.

Chromosome 9 instability and alterations of p16 gene in squamous cell carcinoma of the lung and in adjacent normal bronchi: FISH and immunohistochemical study.

AIMS: p16, a tumour suppressor gene located at 9p21 chromosome and involved in cell cycle regulation, is often inactivated in lung carcinoma. Inactivation is also supported by the loss of p16 protein, a strong inhibitor of cyclin-dependent kinase (CDK) 4 and 6. The aim of this study was to examine alterations of p16 both in pulmonary squamous cell carcinoma (SCC) and in morphological normal bronchi contiguous with neoplasia. METHODS AND RESULTS: p16 gene and chromosome 9 alterations were examined by fluorescence in situ hybridization and the expression of p16 protein by immunohistochemistry in pulmonary surgical specimens from 31 patients with SCC. As controls, surgical specimens from 13 patients with non-neoplastic pathology were examined. Tumours showed molecular alterations for p16 gene and chromosome 9 abnormalities in, respectively, 29/31 and 19/31 cases respectively. p16 protein was unexpressed in 29/31 cases. In morphologically normal bronchi p16 gene and chromosome 9 alterations occurred in, respectively, 13/31 and 4/31 cases respectively; loss of protein immunoreactivity occurred in 14/31 cases. No alterations were seen in any of the control cases. CONCLUSIONS: Inactivation of p16 gene in histologically normal bronchi could aid the identification of individuals at risk of developing SCC of the lung.

Spermatozoal ultrastructure in three species of the genus Uca Leach, 1814 (Crustacea, Brachyura, Ocypodidae).

Morphological aspects of spermatozoa in marine animals have been used in recent decades as phylogenetic criteria (spermiotaxonomy). This paper presents ultrastructural descriptions of the spermatozoa from Uca maracoani, U. thayeri, and U. vocator. A small portion of the vas deferens of each species was examined under the transmission and scanning electron microscopy. The ultrastructural analysis showed that each spermatophore consists of a varying number of spermatozoa embedded in a dense fibrillar matrix surrounded by a membrane. The spermatozoa of U. maracoani, U. thayeri, and U. vocator are typical of brachyurans. The voluminous acrosome is characterized by three different layers. The postero-lateral surface of the acrosome is cupped by the reduced cytoplasm, and the anterior surface is covered by the operculum. The perforatorium consists of coiled, helicoidal membranous tubules and is continuous with the cytoplasm. The nucleus is composed by uncondensed chromatin and presents several lateral arms distributed over the entire equatorial plane of the cell. The presence of the apical button is a well defined character among all species of the genus Uca, but in U. thayeri it was not observed. The accessory opercular ring can be found in the three studied species, but in distinct development degree. Two centrioles were detected in U. thayeri and U. vocator, but only one was found in U. maracoani. The presence of centrioles in the mature spermatozoa is the first account for the genus Uca upto-date. Considering the ultrastructure of the spermatozoa of U. maracoani, U. thayeri, and U. vocator, we suggest that these three species partially follow the morphological patterns previously described in other Thoracotremata brachyurans. The absence of the apical button in U. thayeri spermatozoa may represent an evolutionary novelty in the genus Uca.

Population and reproductive biology of the crab Uca burgersi (Crustacea: Ocypodidae) in three subtropical mangrove forests

Population and reproductive biology were studied in three populations of the crab Uca burgersi Holthuis, 1967, in the Indaiá, Cavalo and Ubatumirim mangrove forests (Ubatuba, São Paulo State, Brazil). Crabs were collected during low tide (August 2001 through July 2002), by digging the sediment, with a standard capture effort (two persons for 30 min.). Carapace width was measured, and gonad developmental stage was recorded from all specimens. U. burgersi was most abundant in the Cavalo mangrove, where the largest male was found. Juvenile crabs were found year-round at all three sites. However, the ratio of ovigerous females was very low, even null in the Cavalo mangrove. The gonad development rate indicated that U. burgersi was reproducing continuously, but more intensively during spring and summer, with recruitment occurring in winter. The synchrony between the populational and reproductive biology in the three areas showed that local features were not the limiting factors. It is suggested that this species is a habitat generalist.

Estudiamos la biología poblacional y reproductiva de tres poblaciones de Uca burgersi Holthuis, 1967, en los manglares de Indaiá, Cavalo y Ubatumirim (Ubatuba, São Paulo, Brasil). Los cangrejos fueron recolectados por excavación de sedimentos, con un esfuerzo de capturaestándar (dos personas por 30 min), durante la marea baja, entre agosto 2001 y julio 2002. En todos los especimenes se midió la anchura del caparazón y se registró la etapade desarrollo gonadal. Esta especie fue más abundante en Cavalo, donde se halló el macho de mayor tamaño.Encontramos juveniles en los tres sitios, durante todo el período de estudio. Sin embargo, la proporción de hembrasovígeras fue muy baja (nula en Cavalo). Según el desarrollo gonadal, el periodo reproductivo fue continuo allí, pero más intenso durante la primavera y el verano, con reclutamiento en el invierno. La sincronía entre la biologíapoblacional y reproductiva de las tres poblaciones, demuestra que las características locales no fueron los factores limitantes. Se sugiere que esta especie es generalista con respecto al hábitat.

Influence of curing rate of resin composite on the bond strength to dentin.

This study determined whether the strength with which resin composite bonds to dentin is influenced by variations in the curing rate of resin composites. Resin composites were bonded to the dentin of extracted human molars. Adhesive (AdheSE, Ivoclar Vivadent) was applied and cured (10 seconds @ 1000 mW/cm2) for all groups. A split Teflon mold was clamped to the treated dentin surface and filled with resin composite. The rate of cure was varied, using one of four LED-curing units of different power densities. The rate of cure was also varied using the continuous or pulse-delay mode. In continuous curing mode, in order to give an energy density totaling 16 J/cm2, the power densities (1000, 720, 550, 200 mW/cm2) emitted by the various curing units were compensated for by the light curing period (16, 22, 29 or 80 seconds). In the pulse-delay curing mode, two seconds of light curing at one of the four power densities was followed by a one-minute interval, after which light cure was completed (14, 29, 27 or 78 seconds), likewise, giving a total energy density of 16 J/cm2. The specimens produced for each of the eight curing protocols and two resin composites (Tetric EvoCeram, Ivoclar Vivadent; Filtek Supreme XT, 3M ESPE) were stored in water at 37 degrees C for seven days. The specimens were then either immediately subjected to shear bond strength testing or subjected to artificial aging (6,000 cycles between 5 degrees C and 55 degrees C baths) prior to testing. Failure modes were also assessed. The shear bond strengths were submitted to factorial analysis of variance, and the failure modes were submitted to a Chi-square test (alpha = 0.05). All but power density (curing mode, resin composite material and mode of aging) significantly affected shear bond strength. The curing mode and resin composite material also influenced the failure mode. At the selected constant energy density, pulse-delay curing reduced bonding of the resin composite to dentin.

Inadequate dietary intake but not renal tubular acidosis is associated with bone demineralization in primary biliary cirrhosis.

BACKGROUND: Metabolic bone disease associated with primary biliary cirrhosis (PBC) is inadequately characterized. Renal tubular acidosis (RTA) may lead to bone loss through chronic mobilization of skeletal calcium salts to buffer increased acid load. AIM: To evaluate the prevalence of RTA in PBC and establish the relationships among bone mineral density (BMD), renal function and nutritional status. METHODS: We enrolled 69 female patients with compensated PBC and 35 control patients with chronic hepatitis C. RTA was searched in all patients, and 24-h dietary recalls were collected at enrolment. BMD was measured by dual-energy X-ray absorptiometry at the femur neck, lumbar spine and radius ultradistalis sites. RESULTS: No patients received a diagnosis of RTA. BMD values (Z-scores) showed only little deviation from normal population with no difference between PBC and controls. Osteopoenic PBC patients (T-score < 1) showed significantly lower daily phosphorus intake [median: 672 (288-1374) vs. 921 (253-1923) mg/day; P = 0.037], with a trend towards lower caloric intake than their nonosteopoenic counterparts. CONCLUSIONS: Renal tubular acidosis is uncommon in compensated PBC. Cholestasis is not associated with an increased risk of bone demineralization. Inadequate dietary intake may be a preventable factor contributing to bone loss in PBC.