Strength of a Zirconia- Reinforced Glass-Ceramic After Diamond Bur Adjustment.

INTRODUCTION: Adjustments with diamond burs on the ceramic surface can affect its roughness and decrease flexural strength. This study evaluated the effect of polishing or glazing on the surface roughness and biaxial flexural strength of a zirconia-reinforced lithium silicate glass-ceramic upon adjustment with diamond burs. METHODS: Seventy disks were prepared according to ISO 6872 and divided into seven groups (n = 10) according to different adjustments and finishing processes. Surface roughness was measured prior to biaxial flexural strength testing. The topography was analyzed using an atomic force microscope , fracture markings were identified using a stereomicroscope and representative specimens were analyzed using scanning electron microscopy. RESULTS: The use of diamond burs significantly increased the surface roughness and decreased the strength of the evaluated ceramic (p⟨0.05). Polishing reduced the ceramic's roughness but resulted in flexural strength similar to that of the groups with wear (p⟩0.05). The glaze-treated specimens showed flexural strength statistically similar to the control group (p>0.05) but higher roughness, similar to those with wear. CONCLUSIONS: Polishing reduced the surface roughness but did not affect the biaxial flexural strength of the ZLS ceramic. At the same time, the application of glaze after wear increased the strength.

Cardiovascular disease in early kidney transplantation: comparison between living and deceased donor recipients.

BACKGROUND: Cardiovascular disease (CVD) mortality is extremely high among kidney transplant recipients (KTRs), particularly in the first months after transplantation. Few data are available comparing the cardiovascular profile between KTRs from living versus deceased donors. OBJECTIVES AND METHODS: The aim of the present study was to evaluate the prevalence of CVD in the first 2 months following transplantation, among 120 KTRs of living versus deceased donor organs. RESULTS: Left ventricular hypertrophy was observed in 65% of patients, coronary artery calcification in 30%, and cardiac arrhythmias in 46%. CVD was more prevalent among KTRs from deceased versus living donors: ventricular hypertrophy 87% versus 59% (P = .008); coronary artery calcification 42% versus 24% (P = .04); and cardiac arrhythmias 59% versus 39% (P = .06). Multiple logistic regression analysis adjusted for age and dialysis vintage, showed graft donor to not be associated with the prevalence of any CVD (ß coefficient 0.912, 95% confidence interval 0.276-3.012, P = .88). CONCLUSION: In conclusion, the present study demonstrated an elevated prevalence of CVD among KTRs. Patient characteristics, mainly longer length on dialysis seemed to contribute to a greater prevalence of cardiovascular complications among KTRs from deceased compared with living donors on univariate but not multivariate analysis.

[Epidemiological pattern of lymphatic filariasis in children living in endemic areas]. / Perfil epidemiológico da filariose linfática em crianças residentes em áreas endêmicas.

OBJECTIVE: Lymphatic filariasis still represents a major public health problem in the city of Recife. In spite of the fact that previous surveys had already shown high frequency of microfilaraemia in pediatric population, the prevalence of filarial disease and the microfilaraemic pattern of this group were unknown. This paper describes the clinical-epidemiological pattern of filariasis in children and adolescents living in two highly endemic areas of Recife. METHODS: The parasitological survey was done through a census carried out between December 1990 and July 1991. Thick drop technique (45 micro l) was performed on a total of 1,464 children and adolescents between the ages of 5 and 14, of whom 967 were submitted to clinical examination. Positive cases had their blood recollected (60 micro l) to measure the microfilaraemic density. RESULTS: The microfilaraemia prevalence was 6.4 %. In the age groups of 5 to 9 and 10 to 14 a microfilaraemia prevalence of respectively 4.6% and 8.3% was observed. The microfilaraemic density varied from 3 to 864 microfilariae per 60 microl of blood, there having been no statistically significant difference between the sexes and age groups (p<0.05). 6 cases (0.6 %) of acute filarial disease and 11 of chronic filarial disease (1.1%) were identified, hydrocele being the principal manifestation found. Lymphadenopathy was found in 22% of the children, statistical association with microfilaraemia being observed (p<0.001). CONCLUSIONS: The results of the parasitological survey show the strong presence of children in the contingent of microfilaraemic individuals, indicating an early and intense exposure to filariasis in the population studied.

Y-linked suppressors of the sex-ratio trait in Drosophila mediopunctata.

X-linked meiotic drive causing female-biased progenies is known to occur in nine Drosophila species and is called 'sex-ratio'. In D. mediopunctata this trait is associated with the X:21 chromosome inversion and has variable expression. We describe here a powerful Y-linked suppressor system of sex-ratio expression in this species. There are two types of Y chromosomes (suppressor and nonsuppressor) and two types of X:21 chromosomes (suppressible and unsuppressible). Sex-ratio expression is suppressed in males with the 21suppressible/Ysuppressor genotype, whereas the remaining three genotypes produce female-biased progenies.

Autosomal suppressors of sex-ratio in Drosophila mediopunctata.

The sex-ratio trait has been described as the production of progenies with excess of females due to X-linked meiotic drive in the parental males. This trait has a variable expression in Drosophila mediopunctata. We describe here the existence and chromosomal localization of autosomal suppressors of sex-ratio in this species. There are at least four such genes (one on each major autosome) and the strongest effect is localized on chromosome IV. These genes possibly result from the operation of 'Fisher's Principle'; a mechanism of Natural Selection leading to a 1:1 sex ratio.

Chronic stress from the Goiania 137Cs radiation accident.

At the invitation of the Brazilian government, the authors conducted a multidisciplinary field study in Goiania, Brazil, 3 1/2 years after an accident involving 137Cs, a radioactive cesium isotope. They compared subjects exposed to low levels of ionizing radiation, subjects who experienced anticipatory stress from fear of radiation exposure, and a nonirradiated control group. Results indicated the presence of chronic stress, as measured by psychological, behavioral, and neuroendocrine indices, in subjects who were exposed as well as in subjects fearful of potential radiation exposure. Anticipatory stress associated with potential exposure to ionizing radiation resulted in a level of stress similar to that from actual exposure to ionizing radiation. These findings have implications for past and future radiation accidents.

[Simulation in the teaching of the cardiorespiratory system: a report of innovative experience]. / Simulação no ensino do sistema cardiorrespiratório: relato de uma experiência inovadora.

The nurse teachers in charge of the Auxiliary Nursing Course at the Heart Institute (InCor-FMUSP) propose simulation as an innovative teaching strategy and describe its application to the Cardiorespiratory System. By doing this, they make their students participate actively in their classes, thus improving the teaching-learning process.

Age and sex-ratio expression in Drosophila mediopunctata.

The sex-ratio trait--production of progenies with excess of females due to X-linked meiotic drive in parental males--has a variable expression in Drosophila mediopunctata. We tested the effect of male age and found that aging increases the expression of sex-ratio, a fact relevant for the interpretation of field data and for experimental design.

Osteomalacia secondary to renal tubular acidosis in a patient with primary Sjögren's syndrome.

We report a case of a 41-year-old woman whose disease manifested as osteomalacia and whose etiological investigation revealed renal tubular acidosis secondary to primary Sjögren's syndrome. Proximal tubular dysfunction was also present and was documented by increased urinary excretion of beta-2-microglobulin and retinol-binding protein. The patient showed clinical and laboratory improvement after treatment with oral potassium citrate, calcium supplements and steroids.

The use of dacron plates for dot enzyme-linked immunosorbent assay (dot-ELISA).

Dacron (polyethylenetherephthalate) is proposed as a matrix for dot-ELISA procedures, as an alternative to nitrocellulose. Plates of dacron were partially hydrazinolyzed and hydrazide groups introduced were converted to azide groups. The derivative dacron-antigen was covalently linked on to the plates through these azide groups. The derivative dacron-antigen was exaustively washed according to CROOK and antigen was still fixed onto the plates. Protein F1A purified from Yersinia pestis was used as a model. Titration of sera from immunized and non immunized rabbits against this protein was carried out by employing the dot-ELISA method. No significant difference was observed using dacron-antigen and nitrocellulose-antigen preparations. However, both procedures showed to have a significant better performance in comparison with the passive hemagglutination method. The specificity and reproductibility of the dot-ELISA assay using both preparations showed a similar behaviour. Nitrocellulose preparation was stable at 4 degrees C, 28 degrees C and -20 degrees C for 90 days, whereas the dacron-antigen derivative was stable only when stored at 4 degrees C. Dacron-antigen derivative could be re-used when the spot developing was proceeded using 4-chloro-1-naphtol as substrate.

[Effects of non-specific immunopotentiators on experimental Schistosoma mansoni infection. I. Levamisole]. / Efeitos de imunopotenciadores não específicos na infecção experimental pelo Schistosoma mansoni. I. Levamisole.

The effects of levamisole on the histopathological changes, host's resistance and "in vivo" chemotaxis in Schistosoma mansoni experimental infection of C57Bl/10 inbred mice were studied. Prophylactic treatment resulted in an increase in the number of adult worms obtained by perfusion and also increased the mortality rate (p < 0.05). The histopathological changes (liver and intestines) were similar in all the groups. A significant reduction of "in vivo" chemotaxis occurred in infected control mice as well as in those submitted to prophylactic treatment with levamisole. Chemotactic activity reached the same levels of normal control mice (non-infected and non-treated with levamisole), when the curative scheme was used. Levamisole seems to increase the susceptibility of inbred C57Bl/10 mice to the infection with S. mansoni when administered prior to the infection and increase the chemotactic activity to normal levels when given after infection.

Natural lectin activity in the haemolymph of Panstrongylus megistus (Heteroptera: Reduviidae).

The haemolymph of Panstrongylus megistus showed a natural lectin activity for a wide range of vertebrate erythrocytes. Agglutination was observed against all vertebrate erythrocytes tested (human ABO, duck, rabbit, mouse, sheep, chicken and cow). Cow erythrocytes showed the lowest titre. Concerning human erythrocytes, the lectin activity was similar in the types A+, B+ and AB+ while the highest activity was observed in the type O+. Determination of minimal inhibitory concentrations was carried out with human erythrocytes type O+. Agglutination was inhibited by several carbohydrates (rhamnose, D-galactose, raffinose, D-lactose and D-fucose). Rhamnose was reported as the strongest inhibitor (0.78 mM). The results suggest the presence of more than one lectin in the haemolymph of P. megistus.