Effects of guanethidine-induced sympathectomy on the spermatogenic and steroidogenic testicular functions of prepubertal to mature rats

Selective chemical sympathectomy of the internal genital organs of prepubertal to mature male Wistar rats was performed by chronic treatment with low doses of guanethidine. Sympathetic denervation caused an increase in intratesticular progesterone levels in prepubertal and early pubertal rats in addition to a decrease in androstenedione and testosterone levels in prepubertal animals, thus indicating a decrease in the conversion of progesterone into androgen, probably by blocking the steroidogenic enzymatic pathway at the 17 alpha-hydroxylase/17,20 desmolase level. A lower degree of testicular maturation, probably related to reduced androgen activity, was observed in prepubertal and early pubertal sympathectomized rats. Concentration of spermatozoa, on the other hand, was increased in the enlarged cauda epididymidis of late pubertal and mature denervated animals. This result is discussed in terms of the impairment of epididymal mechanisms of seminal emission, fluid resorption and spermatozoal disposal.

Bone regeneration at implants placed into extraction sockets of maxillary incisors in dogs

AimTo compare the influence of autologous or deproteinized bovine bone mineral as grafting material on healing of buccal dehiscence defects at implants installed immediately into the maxillary second incisor extraction socket in dogs.Material and methodsIn the maxillary second incisor sockets of 12 Labrador dogs, implants were installed immediately following tooth extraction. A standardized buccal defect was created and autologous bone particles or deproteinized bovine bone mineral were used to fill the defects. A collagen membrane was placed to cover the graft material, and the flaps were sutured to fully submerge the experimental areas. Six animals were sacrificed after 2 months, and six after 4 months of healing. Ground sections were obtained for histological evaluation.ResultsAfter 2 months of healing, all implants were osseointegrated. All buccal dehiscence defects were completely filled after 2 months irrespective of the augmentation material (autologous bone or Bio-Oss (R)) applied. Bone-to-implant contact (BIC) on the denuded implant surfaces was within a normal range of 30-40%. However, the newly formed tissue at 2 months was partially resorbed (> 50% of the area measurements) after 4 months.ConclusionsApplying either autologous bone or deproteinized bovine bone mineral to dehiscences at implants installed immediately into extraction sockets resulted in high degree of regeneration of the defects with satisfactory BIC on the denuded implant surface.To cite this article:De Santis E, Botticelli D, Pantani F, Pereira FP, Beolchini M, Lang NP. Bone regeneration at implants placed into extraction sockets of maxillary incisors in dogs.Clin. Oral Impl. Res. 22, 2011; 430-437.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 May 2009-31 July 2009

This article documents the addition of 512 microsatellite marker loci and nine pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Alcippe morrisonia morrisonia, Bashania fangiana, Bashania fargesii, Chaetodon vagabundus, Colletes floralis, Coluber constrictor flaviventris, Coptotermes gestroi, Crotophaga major, Cyprinella lutrensis, Danaus plexippus, Fagus grandifolia, Falco tinnunculus, Fletcherimyia fletcheri, Hydrilla verticillata, Laterallus jamaicensis coturniculus, Leavenworthia alabamica, Marmosops incanus, Miichthys miiuy, Nasua nasua, Noturus exilis, Odontesthes bonariensis, Quadrula fragosa, Pinctada maxima, Pseudaletia separata, Pseudoperonospora cubensis, Podocarpus elatus, Portunus trituberculatus, Rhagoletis cerasi, Rhinella schneideri, Sarracenia alata, Skeletonema marinoi, Sminthurus viridis, Syngnathus abaster, Uroteuthis (Photololigo) chinensis, Verticillium dahliae, Wasmannia auropunctata, and Zygochlamys patagonica. These loci were cross-tested on the following species: Chaetodon baronessa, Falco columbarius, Falco eleonorae, Falco naumanni, Falco peregrinus, Falco subbuteo, Didelphis aurita, Gracilinanus microtarsus, Marmosops paulensis, Monodelphis Americana, Odontesthes hatcheri, Podocarpus grayi, Podocarpus lawrencei, Podocarpus smithii, Portunus pelagicus, Syngnathus acus, Syngnathus typhle,Uroteuthis (Photololigo) edulis, Uroteuthis (Photololigo) duvauceli and Verticillium albo-atrum. This article also documents the addition of nine sequencing primer pairs and sixteen allele specific primers or probes for Oncorhynchus mykiss and Oncorhynchus tshawytscha; these primers and assays were cross-tested in both species.

Advertisement call of Scinax littoralis and S. angrensis (Amphibia: Anura: Hylidae), with notes on the reproductive activity of S. littoralis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Analytical method for the design of a machine with aligned and skewed permanent magnets

This work aims to present the design and the evaluation of a standard multi-pole machine with permanent magnets inserted in the rotor by two different geometrical forms: aligned and skewed magnets. The design (new analytical method) was based on a standard 250 W three phase 12-pole induction motor (squirrel cage rotor type), beginning with the original stator constructive data to calculate the magnetic flux density to determine the permanent magnets. In the development of the work, a simple and modular rotor was built reusing the original 12-pole stator (concentrated windings). The machine was evaluated in a laboratory for the purpose of checking the quantity and quality of energy produced with the machine operating as a generator and its start, torque, and performance working as a motor. In conclusion, the modular skewed magnet is an option for electrical machines, for the generation of a reasonable quality, in the context of decentralized generation and a motor with high torque and low energetic consumption.

Enamel Defects in Maxillary Central Incisors of Infants With Unilateral Cleft Lip

Objective: To evaluate the presence of enamel alterations in deciduous maxillary central incisors of infants with unilateral cleft lip and alveolar ridge, with or without cleft palate, and to compare the occurrence and location of these alterations between the central incisor adjacent to the cleft and the contralateral incisor.Design: Intraoral clinical examination was performed after tooth cleaning and drying by a single examiner with the aid of a dental mirror, dental probe, and artificial light, with the child positioned on a dental chair. The defects were recorded in a standardized manner according to the criteria of the Modified Developmental Defects of Enamel Index.Setting: Hospital for Rehabilitation of Craniofacial Anomalies (HRAC) at Bauru, São Paulo, Brazil.Patients: One hundred one infants were evaluated. All were white, of both genders, aged 12 to 36 months and had at least two thirds of the crowns of maxillary incisors erupted.Results: Demarcated opacity was the most common defect at both cleft and noncleft sides, followed by diffuse opacity. The occurrence of hypoplasia at the cleft side was 11.8%. Most defects affected less than one third of the crown.Conclusion: The occurrence of enamel defects in deciduous maxillary central incisors of patients with unilateral cleft lip was 42.6%, mainly affecting the cleft side as to both number and severity.

Fifteen-year Follow-up of a Conservatively Managed, Root-fractured Permanent Incisor

The purpose of this case report was to describe the successful long-term conservative management of a root-fractured permanent maxillary right central incisor in an 8-year-old patient. After the initial approach of splinting the traumatized tooth, the patient was followed on a regular basis for 15 years. Clinically, the crown of the root-fractured incisor showed no displacement or discoloration, and thermal tests suggested pulp vitality over the follow-up period. Radiographically, an increase in the diastasis was observed between the apical and coronal fragments due to both the growth of the alveolar process and the healing with interposition of hard and soft tissue between the fragments and confirmed with computed tomography scan in the 15-year follow-up appointment. (Pediatr Dent 2012;34:156-8) Received June 21, 2010 vertical bar Lost Revision August 18, 2010 vertical bar Accepted August 27, 2010

Autoradiographic investigation of effects of high-dose colchicine on dentinogenesis in rat incisors

Twelve female Wistar rats received 1.5 mg/kg of colchicine (CLC) intravenously. Control animals were similarly injected with isotonic saline solution. The animals were killed 5 h, 24 h, 3 days and 7 days after injection. Ninety minutes prior to sacrifice, all animals received an intraperitoneal injection of 3H-proline. Autoradiograms of maxillary incisors showed that CLC increased the retention of the labeled precursor in the odontoblasts. It was also shown that the odontoblasts in the different sectors of the rat incisor present different sensitivities to the CLC action.

Cell death in ovarioles causes permanent sterility in Frieseomelitta varia worker bees

Frieseomelitta varia worker bees do not lay eggs even when living in queenless colonies, a condition that favors ovary development and oviposition in the majority of highly social bees. The permanent sterility of these worker bees was initially attributed to a failure in ovary morphogenesis and differentiation. Using transmission electron microscopy we found that at the beginning of the pupal phase the ovaries of F. varia workers are formed by four ovarioles, each of them composed of 1) a terminal filament at the apex of the ovarioles, containing juxtaposed and irregularly shaped cells, 2) a germarium with clusters of cystocytes and prefollicular cells showing long cytoplasmic projections that envelop the cystocyte clusters, 3) fusiform interfollicular and basal stalk precursor cells, and 4) globular, irregularly contoured basal cells with large nuclei. However, during the pupal phase an accentuated and progressive process of cell death takes place in the ovarioles. The dying cells are characterized by large membrane bodies, electron-dense apoptotic bodies, vacuoles, vesiculation, secondary lysosomes, enlarged rough endoplasmic reticulum cisternae, swollen mitochondria, pycnotic nuclei, masses of chromatin adjacent to the convoluted nuclear envelope, and nucleoli showing signs of fragmentation. Cell death continues in ovarioles even after the emergence of the workers. Once they become nurse bees, the ovaries have become transformed into a cell mass in which structurally organized ovarioles can no longer be identified. In F. varia workers, ovariole cell death most certainly is part of the program of caste differentiation.

Immediate replantation of maxillary incisors in rats: effects of tooth immersion in sodium fluoride and subsequent removal of the periodontal ligament.

The advantages and disadvantages of maintaining the periodontal ligament (PDL) in immediate replantation as well as chemical treatment of the root surface have been a matter of discussion because the vitality of such tissue in surgery is always questioned. This study evaluated the effects of conserving the tooth in sodium fluoride and the removal of the PDL before replantation of incisors in rats. There was more cementum-dentin resorption in the group with the PDL. The group without the PDL showed more discreet resorption, repair occurred through the newly formed bone tissue in the PDL space and ankylosis was more extensive than in the group with the PDL.

Influence of the diet on in situ disappearance of dry matter, organic matter, and neutral detergent fiber of hydrolysed sugar cane bagasse

The effects of two diets based on hydrolysed sugarcane bagasse (HSB) and whole cottonseed (WCS), with or without oat hay, were analyzed for the in situ disappearance of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) of HSB. Six mature castrated rams with a permanent T ruminai cannula were used in a complete randomized split plot design. The incubation times were 3, 6, 9, 12, 24, 48 and 72h. The diet with oat hay showed higher disappearance indexes for the NDF fraction. Furthermore, the maximum degradation of HSB constituents was reached around 48h of incubation. The diets were T1=64% hydrolyzed sugarcane + 36% whole cottonseed and T2=14% hydrolyzed sugarcane bagasse + 36% cottonseed + 50% oat hay.

Hypogaeic anti epigaeic ant (Hymenoptera: Formicidae) assemblages of atlantic costal rainforest and dry mature and secondary amazon forest in Brazil: Continuums or communities

Meat, flour and sugar baits were used on the soil surface and buried to examine species composition of the ant fauna in three separate tropical forests in Brazil, and to control for the effect of the regional faunal pool. Compositional mosaic diversities were comparable among areas, bait types and foraging strata. Mosaic diversity was independent of mean assemblage size. The number of unique species per sampling unit was correlated with mean assemblage size. Canonical correspondence analysis ordered species first by foraging substrate, second by geographic location, and third by diet. The first axis was significantly correlated with mean similarity and affinity. Mean Mahanalobis distances between centroids of groups based upon foraging strata were significantly larger than between localities, indicating local ecological pressures stronger than regional species pool constraints. As most. species foraged in only one stratum in one geographical position and were not omnivorous, the response of species to environmental gradients (continuums) showed a lower coherency with these patterns than did communities, structured around guilds based upon foraging strata and diet.

In vitro penetration of bleaching agents into the pulp chamber

Aim: To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures. Methodology: Bovine lateral incisors were sectioned 3 mm apical to the cemento-enamel junction and the coronal pulpal tissue was removed. Teeth were divided into six groups (n = 10): G1, G2 and G3 were not submitted to any restorative procedure, while G4, G5 and G6 were submitted to Class V preparations and restored with composite resin. Acetate buffer was placed in the pulp chamber and treatment agents were applied for 60 min at 37°C as follows: G1 and G4, immersion into distilled water; G2 and G5, 10% carbamide peroxide (CP) exposure; G3 and G6, 35% CP bleaching. The buffer solution was removed and transferred to a glass tube where leuco crystal violet and horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined spectrophotometrically at 596 nm. A standard curve made with known amounts of hydrogen peroxide was used to convert the optical density values of the coloured samples into microgram equivalents of hydrogen peroxide. Data were submitted to ANOVA and Tukey's test (5%). Results: Amounts of hydrogen peroxide found in the pulp chamber of G2 and G5 specimens (0.1833 ± 0.2003 μg) were significantly lower (P = 0.001) when compared to G3 and G6 specimens (0.4604 ± 0.3981 μg). Restored teeth held significantly higher (P = 0.001) hydrogen peroxide concentrations in the pulp chamber than intact teeth. Conclusion: Higher concentrations of the bleaching agent produced higher levels of hydrogen peroxide in the pulp chamber, especially in restored teeth.