Prevalence of deciduous tooth erosion in childhood.

OBJECTIVES: The objective of this study was to estimate the prevalence of deciduous tooth erosion and to identify possible associations with sex, age and toothbrushing frequency in children aged 4-6 years. METHODS: The sample was drawn from attendants (n = 7058) of 57 public preschools in a Brazilian city. Tooth wear index was used to evaluate erosion. Descriptive statistical analysis consisted of the calculation of the prevalence of dental erosion; chi-squared and Fisher's exact tests were performed to verify the association between dental erosion and sex, age and toothbrushing frequency. RESULTS: Two thousand and seven hundred and fifty-nine preschool students were examined. Deciduous tooth erosion was observed in 0.6% of children and its incidence did not differ between sexes. The highest prevalence was observed in children aged 6 years (58.3%) and the most affected sextants were the fourth (22.86%) and sixth (20.00%), indicating that lingual and occlusal tooth surfaces were most frequently involved. The degree of involvement was classified as incipient in 54.29% of children and moderate in 45.71%. The significance level was set at 5%. No association was found between erosion and sex, age or toothbrushing frequency. CONCLUSIONS: The prevalence of deciduous tooth erosion was low in Brazilian children, and this disorder is not considered a public health problem in this part of the population.

Effects of prenatal hypoxia-ischemia on male rat periaqueductal gray matter: Hyperalgesia, astrogliosis and nitrergic system impairment.

Prenatal hypoxic-ischemic insult (HI) may lead to a variety of neurological consequences that may persist throughout adulthood. In the most severe cases, HI is known to increase pain sensitivity which profoundly impacts quality of life. Periaqueductal gray matter (PAG) is a relevant region of the descending pain pathway and its function may be modulated by a complex network that includes nitrergic neurons and glial response, among other factors. Astrocytes, central players in pain modulation, are known to respond to HI by inducing hyperplasia, hypertrophy and increasing the number of their processes and the staining of glial fibrillary acidic protein (GFAP). In this work we investigated the effects of prenatal HI on touch and pain sensitivity, besides the distribution of the neuronal isoform of Nitric Oxide Synthase (nNOS) and GFAP in the PAG of young and adult male rats. At 18 days of gestation, rats had their uterine arteries clamped for 45 min (HI group). SHAM-operated animals were also generated (SHAM group). At post-natal day 30 (P30) or 90 (P90), the offspring was submitted to the behavioral tests of Von Frey and formalin or histological processing to perform immunohistochemistry for nNOS and GFAP. Although there was no significant difference between the groups concerning touch sensitivity, we observed an increase in pain sensitivity in HI P30 and HI P90. The number of nNOS + cells was reduced in HI adult animals in dlPAG and vlPAG. GFAP immunostaining was increased in HI P90 in dlPAG and dmPAG. Our results demonstrated for the first time an increase in pain sensitivity as a consequence of prenatal HI in an animal model. It reinforces the relevance of this model to mimic the effects of prenatal HI, as hyperalgesia.

Poultry offal meal in chicken: traceability using the technique of carbon (13C/12C)- and nitrogen (15N/14N)-stable isotopes.

Studies on the detection of animal by-products in poultry meat are rare and practically nonexistent in chicken meat. With the development of the technique of stable isotopes for traceability purposes and the certification of broiler diet patterns, it has been necessary to know the behavior of the isotopic signature of different tissues in birds, in case of a potential replacement of a diet containing animal ingredients with a strictly vegetable one and vice versa. Thus, this study, carried out at the São Paulo State University, Botucatu Campus, Brazil, aimed to evaluate meat from the breast, thigh, drumstick, and wings to trace the presence of poultry offal meal (OM) in broiler feed using the analysis of stable isotopes of carbon ((13)C/(12)C) and nitrogen ((15)N/(14)N) by mass spectrometry. In total, 720 one-d-old chicks were distributed into 6 groups: vegetable diet (VD) from 1 to 42 d; 8% poultry offal meal (OM) diet from 1 to 42 d; VD from 1 to 21 d and 8% OM diet from 22 to 42 d; VD from 1 to 35 d and 8% OM diet from 36 to 42 d; 8% OM diet from 1 to 21 d and VD from 22 to 42 d; and 8% OM diet from 1 to 35 d and VD from 36 to 42 d. Through the analysis of C and N, it is possible to trace the use of OM in broiler feeding when this ingredient is part of the feeding throughout the breeding phase or when it substitutes a strictly VD even up to 35 d. When an OM diet is substituted by a VD, the animal ingredient has to be part of the feeding for 21 d or longer to be detected by this method.

Anatomical alterations due to polyploidy in cassava, Manihot esculenta Crantz.

Information on anatomical structure is needed by breeders working on improvement for drought tolerance. For studying the effect of polyploidy on cassava anatomy and its significance to tolerance to drought, we induced a polyploidy type of a selected clone (UnB 530) by applying an aqueous solution of 0.2% colchicine on lateral buds for a period of 12 h. The stem identified as tetraploid was propagated to produce the whole plant. Free-hand cross-sections of the median portion between stem internodes were made. They were clarified using 50% sodium hypochlorite solution, stained with 1% safranin-alcian blue, passed through an ethanol series and butyl acetate and mounted in synthetic resin. The tetraploid type showed more prismatic and druse crystals in the cortical parenchyma, and its pericycle fibers had thicker walls. The secondary xylem of tetraploid types was wider than diploid ones, having thinner walls and less starch.

Trap-Nesting Bees in Montane Grassland (Campo Rupestre) and Cerrado in Brazil: Collecting Generalist or Specialist Nesters.

Species richness and seasonal abundance of solitary bees were investigated in rocky, montane grassland (campo rupestre) (1180 m asl) and cerrado sensu stricto (680 m asl) in the Biribiri State Park, Diamantina, state of Minas Gerais, Brazil. Three hundred nineteen nest traps of bamboo canes and black cardboard tubes were monthly inspected at each site during 15 months. A total of eight species of bees built 97 nests. Four species were common to both sites. Tetrapedia aff. curvitarsis Friese and Tetrapedia aff. peckoltii Friese were the most abundant at campo rupestre and cerrado s.s., respectively, followed by Centris analis (Fabricius) in campo rupestre and Centris tarsata Smith in cerrado s.s. The nesting peaks occurred in May in campo rupestre and in February in cerrado s.s. Three cuckoo bees and one bee-fly were collected as natural enemies. The findings suggest that differences between the sites were related more to ecological factors (floral resources, natural nest sites) than to the altitudinal difference. The species richness was similar to that in other habitats with open vegetation. We demonstrate the need to use several types of trap-nest to increase the range of species sampled; some species used only one of the two types traps provided. We also comment on the limitations of trap-nests in cerrado vegetation. Most cerrado species of bees are very selective in their choice for a nesting site, but bees that use trap-nests are more generalists.

Anatomical alterations due to polyploidy in cassava, Manihot esculenta Crantz

Information on anatomical structure is needed by breeders working on improvement for drought tolerance. For studying the effect of polyploidy on cassava anatomy and its significance to tolerance to drought, we induced a polyploidy type of a selected clone (UnB 530) by applying an aqueous solution of 0.2% colchicine on lateral buds for a period of 12 h. The stem identified as tetraploid was propagated to produce the whole plant. Free-hand cross-sections of the median portion between stem internodes were made. They were clarified using 50% sodium hypochlorite solution, stained with 1% safranin-alcian blue, passed through an ethanol series and butyl acetate and mounted in synthetic resin. The tetraploid type showed more prismatic and druse crystals in the cortical parenchyma, and its pericycle fibers had thicker walls. The secondary xylem of tetraploid types was wider than diploid ones, having thinner walls and less starch.