300 resultados para fixed prosthodontics
Resumo:
Osteopontin (OPN) is a secreted, calcium-binding phosphorylated glycoprotein involved in several physiological and pathological events such as angiogenesis, apoptosis, inflammation, wound healing, vascular remodeling, calcification of mineralized tissues, and induction of cell proteases. There is growing interest in the role of OPN in breast cancer. In an attempt to obtain new insight into the pathogenesis of OPN-associated breast carcinomas, an immunohistochemical panel with 17 primary antibodies including cytokeratins and key regulators of the cell cycle was performed in 100 formalin-fixed paraffin-embedded samples of invasive breast carcinomas. OPN was expressed in 65% of tumors and was negatively correlated with estrogen (p=0.0350) and progesterone (p=0.0069) receptors, but not with the other markers and clinicopathological features evaluated including age, menstrual status, pathological grading, tumor size, and metastasis. There was no correlation between OPN expression and carcinomas of the basal-like phenotype (p=0.1615); however, OPN correlated positively with c-erbB-2 status (p=0.0286) and negatively with carcinomas of the luminal subtype (p=0.0353). It is well known that carcinomas overexpressing c-erbB-2 protein have a worse prognosis than luminal tumors. Here, we hypothesize that the differential expression of OPN in the first subtype of carcinomas may contribute to their more aggressive behavior. (Int J Biol Markers 2008; 23: 154-60)
Resumo:
The tissue microarray (TMA) technique allows multiple tissue samples in a single block. Commercial adhesive tape is used to avoid the loss of tissue samples during the immunostaining process. Few reports exist in the literature comparing the use of these adhesive tapes to other adhesive techniques. The objective of this study was to compare loss of sections adhered to slides using commercial adhesive tapes versus using silanized only slides. TMA was constructed with varying tissues using a fixed-base device (Beecher Instruments), placing 108 cylinders of 1 mm diameter in duplicate, spaced 1.2 mm apart. Section of 4 mu m were cut from the TMA block and adhered to 30 silanized slides and 30 commercial glass slides using adhesive tape, according to manufacturer`s recommendations. Vimentin immunoexpression was evaluated by immunohistochemistry. Antigenic recovery was realized in citrate buffer using a microwave oven. Cylinder loss in the immunohistochemical process was quantified and expressed as: total (>80%), almost complete (75-79%), or partial (50-74%). The commercial adhesive tape group presented lesser total loss (1.1 versus 6.4%), almost complete loss (2.2 versus 3.5%), and partial loss (2.1 versus 3.8%) than the silanized slide group (ANOVA, P < 0.05). The sum of total and almost complete losses in the silanized slide group was 9.9%, greater than the losses in slides using commercial adhesive tapes (3.3%) and less than reported and considered acceptable in the literature (10-30%). In conclusion, the use of silanized only slides presents very satisfactory results, requires less training, and reduces costs significantly, thus justifying their use in research.
Resumo:
The aim of the present study was to evaluate the genetic and environmental factors affecting records of longissimus muscle area (LMA) and back fat thickness (BF) obtained between the 12th and 13th ribs, and rump fat thickness (RF) between the hook and pin bones, measured by real-time ultrasound in Nelore cattle. Also, weight records of 22,778 animals born from 1998 to 2003, in ten farms across six Brazilian states were used. Carcass traits as measured by ultrasound of the live animal were recorded from 2002 to 2004 in 2590 males and females with ages varying from 450 to 599 days. Fixed models including farm, year and season of birth, sex and type of feed effects, and the covariates age of dam (AOD) and age of animal at measurement were used to study the effect of environmental factors on these traits. The genetic parameters for LMA, BF and RF were estimated with two and three-trait animal models with 120-day weights using a restricted maximum likelihood method. All environmental effects significantly affected carcass traits, with the exception of year of birth for BF and RF and AOD for LMA. The heritability estimates for LMA, BF and RF were 0.35, 0.51 and 0.39, respectively. Standard errors obtained in one-trait analyses were from 0.07 to 0.09. Genetic correlation estimates between LMA and the two traits of subcutaneous fat were low (close to zero) and 0.74 between BF and RF, indicating that the selection for LMA should not cause antagonism in the genetic improvement of subcutaneous fat measured by real-time ultrasound. (C) 2007 Elsevier B.V. All fights reserved.
Resumo:
Saimiri sciureus is one of the smallest Cebidae native of Amazon region and also found at the biological reserve of northeast Atlantic forest. It is an omnivore animal, with diversified diet that directly influences the lingual mucosa, which includes certain types of papillae with different organization levels. The present study attempted to describe the morphological and ultrastructure aspects of the dorsal surface of the S. sciureus. Five tongues of de S. sciureus were analyzed from three males and two females who died from natural causes and were obtained from breeding colonies of CENP-Ananindeua-PA. Main macroscopic features were a general triangular shape with a craniocaudal elongation pointed apex. Tissue samples-apex, body, and root of tongue-were fixed in modified Karnovsky solution, following standard scanning protocol, mounted in stubs, coated by gold, and analyzed by Scanning Electron Macroscopy (SEM). Four types of papillae were described: filiform (along all tissue extension with 154 mu m of diameter), fungiform (along all tissue extension with 272 mu m of diameter), vallate [just three units in caudal (dorsal) portion with 830 mu m of diameter] and foliate (one pair at caudolateral surface with similar to 13 projections and 3000 mu m in length). Data analysis indicates that the distribution and ultra structural morphology of the S. sciureus lingual papillae are some similar to other primates. Microsc. Res. Tech. 74:484-487, 2011. (C) 2010 Wiley-Liss, Inc.
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In the present paper were analysed the three-dimensional characteristics of the interface epithelium-connective tissue surface of finger prints of Cebus apella monkey employing the scanning electron microscopic methods. The connective tissue core (CTC) and epithelial papillae were examined verifying the three-dimensional configuration of the tissue projections. The samples were fixed in Bouin solsution for histologic preparations and in modified Karnovsky for examine to observe in scanning electron microscopy. After treatment in the 10% NaOH solution during 3 to 5 days, the surface of finger prints revealed a distribution of CTC of lamina propria in situ showing original three-dimensional SEM images. The linear and circular dispositions CTC, and the furrows were clearly identified. Each pointed papilla presented a large base and longitudinal disposition of thick collagen fiber bundles and in some areas with a complex reticular formations. The longitudinal furrows between the pointed papillae exhibited a dense layer of connective tissue and showed only low CTC or laminar in shape. The presence of numerous foramina of sweat gland were noted in three-dimensional SEM images.
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This study aimed to develop a plate to treat fractures of the mandibular body in dogs and to validate the project using finite elements and biomechanical essays. Mandible prototypes were produced with 10 oblique ventrorostral fractures (favorable) and 10 oblique ventrocaudal fractures (unfavorable). Three groups were established for each fracture type. Osteosynthesis with a pure titanium plate of double-arch geometry and blocked monocortical screws offree angulanon were used. The mechanical resistance of the prototype with unfavorable fracture was lower than that of the fcworable fracture. In both fractures, the deflection increased and the relative stiffness decreased proportionally to the diminishing screw number The finite element analysis validated this plate study, since the maximum tension concentration observed on the plate was lower than the resistance limit tension admitted by the titanium. In conclusion, the double-arch geometry plate fixed with blocked monocortical screws has sufficient resistance to stabilize oblique,fractures, without compromising mandibular dental or neurovascular structures. J Vet Dent 24 (7); 212 - 221, 2010
Resumo:
The amino acid R or K at position 333 on the glycoprotein of the rabies virus is considered necessary for virulence in adult mice. Although some exceptions exist, substitution at this position causes expression of a phenotype that is either less pathogenic or non-virulent. To date, such substitutions have only been found in fixed strains of rabies virus. In this study, the authors found 333H, 333N, and 333Q substitutions at this position in rabies virus street strains isolated from non-hematophagous bats in Brazil. These strains showed pathogenicity and lethality on passage using adult mice with the intracerebral route and were confirmed rabies-positive by immunofluorescent assay. This suggests that these strains maintain virulence. Our findings indicate that rabies virus street strains with these substitutions exist in the field and may result in infection cycles.
Resumo:
One hundred fifty-one Erysipelothrix spp. isolates from Brazilian swine were characterized by serotyping, determination of antimicrobial susceptibility, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE). Among all isolates, 139 were classified in 18 different serotypes and serotype 2b was the most frequent. The susceptibility profiles of the isolates were very similar among each other, which did not permit subtyping Erysipelothrix spp. isolates by the antimicrobial susceptibility testing. Despite the fact that AFLP and PFGE provided the same discriminatory index (0.98), PFGE was more discriminatory than AFLP, given the types of groups it generates. Regardless the technique employed (AFLP or PFGE), no discrimination between recent and historical isolates was established, neither a fixed epidemiologic pattern for their grouping was observed. Nevertheless, AFLP could be an interesting alternative for discriminating the Erysipelothrix species, while PFGE could be an indication for discerning this bacterium according to the serotypes. (C) 2011 Elsevier Inc. All rights reserved.
Resumo:
The complete genome sequence of wild-type rabies virus (RABV) isolated from a wild Brazilian hoary fox (Dusicyon sp.), the BR-Pfx1 isolate, was determined and compared with fixed RABV strains. The genome structure and organization of the BR-Pfx1 isolate were composed of 11,924 nt and included the five standard genes of rhabdoviruses. Sequences of mRNA start and stop signals for transcription were highly conserved among all structural protein genes of the BR-Pfx1 isolate. All amino acid residues in the glycoprotein (G) gene associated with pathogenicity were retained in the BR-Pfx1 isolate, while unique amino acid substitutions were found in antigenic region I of the nucleoprotein gene and III of G. These results suggest that although the standard genome structure and organization of the RABV isolate are common between the BR-Pfx1 isolate and fixed RABV strains, the unique amino acid substitutions in functional sites of the BR-Pfx1 isolate may result in different biological characteristics from fixed RABV strains.
Resumo:
Gap junctional intercellular communication (GJIC) and connexin expression (Cx26 and Cx32) in mouse liver were studied after administration of 4-bis[2-(3,5 dichloropyridyloxy)]benzene (TCPOBOP), a phenobarbital-like enzyme inducer. Female C57BI/6 mice were administered TCPOBOP (5.8 mg/kg BW) and euthanized 0, 24, 48 and 72 hours later. Liver samples were snap frozen, or fixed in formalin, or submitted to GJIC analysis. The proliferating cell nuclear antigen (PCNA) immunohistochemistry and the Western blotting for Cx26 and Cx32 were performed. After 48 and 72 h of drug administration the liver-to-body weight ratio was increased 70% and 117% (p < 0.0001), respectively. There were temporal-dependent alterations in liver histopathology and a significant increase in cell proliferation was noted after 48h and sustained after 72h, though to a lesser extent (p < 0.0001). In addition. TCPOBOP administration induced apoptosis, which appeared to be time-dependent showing statistical significance only after 72h (p < 0.0001). Interestingly, a transient disruption by nearly 50% of GJIC capacity was detected after 48 h of drug ingestion, which recovered after 72 h (p = 0.003). These GJIC changes were due to altered levels of Cx26 and Cx32 in the livers of TCPOBOP-treated mice. We concluded that a single administration of TCPOBOP transiently disrupted the levels of GJIC due to decreased expression of connexins and increased apoptotic cell death in mouse liver. (C) 2009 Elsevier GmbH. All rights reserved.
Resumo:
Numerous studies have shown that it is possible to manipulate follicular and luteal dynamics, thereby eliminating the need for oestrus detection in embryo transfer (ET) programmes. Fixed-time ET (FTET) protocols are based on the use of gonadotrophin-releasing hormone (GnRH) and prostaglandin (PG) F or progesterone/progestogen (P4)-releasing devices and oestradiol. The FTET protocols increases the proportion of recipients transferred, and therefore pregnancy rates, compared with the use of PGF followed by ET 7 days after oestrus. Furthermore, the addition of equine chorionic gonadotrophin (eCG) to the P4 and oestradiol-based FTET protocols results in an even higher proportion of recipients transferred, and thus higher pregnancy rates. The beneficial effect of eCG treatment may be related to increased growth of the dominant follicle and increased plasma P4 concentrations during the subsequent luteal phase. In Bos taurus x Bos indicus recipients, pregnancy rates were positively correlated with the diameter of the corpus luteum (CL) and the number of CL at ET. When repeat-breeder Holstein cows were used as recipients, FTET protocols increased number of recipients transferred and pregnancy rates compared with the traditional PGF-based synchronisation protocols. In conclusion, the use of FTET protocols eliminates the need for the detection of oestrus and results in a greater proportion of recipients transferred and satisfactory pregnancy rates. Thus, FTET optimises the use of recipients, reducing labour and animal handling and facilitating the use of ET.
Resumo:
This study was conducted to determine the effect of pre-exposure of oocytes to Ricinus communis (RCA-1) lectin and osteopontin (OPN) in uterine tube fluid (UTF) on in vitro sperm-egg binding and fertilization. In vitro-matured bovine oocytes were incubated (39 degrees C, 5% CO(2) in air) for 2 h in the following treatments: (i) 500 mu l of fertilization medium (FM); (ii) 250 mu l of FM with 0.25 ml of non-luteal ampullary uterine tube fluid (NLAUTF); (iii) 250 mu l of FM with 250 mu l of NLAUTF and 4 mu l of RCA-1 lectin; (iv) 250 mu l of FM with 250 mu l of NLAUTF, a rabbit polyclonal antibody (1:200) against purified bovine milk OPN, and RCA-1 lectin; (v) 500 mu l of FM and RCA-1 lectin. Following incubation, oocytes were washed, placed in FM with 2 mu g heparin, and incubated with 1 x 10(5) frozen-thawed spermatozoa per 10 oocytes. Oocytes used to assess sperm binding were stained with Hoescht 33342, and the number of sperm bound per zona pellucida counted. The remaining oocytes were fixed in acid alcohol, stained with 1% acetate-orcein and observed to determine the presence of pronuclei. More sperm bound to the zona pellucida (mean +/- SEM) when oocytes were incubated in treatment 3 (59.0 +/- 5.5) than in treatments 2 (46.4 +/- 5.6), 4 (18.1 +/- 5.4), 5 (33.4 +/- 5.6) or 1 (32.5 +/- 5.6). More oocytes were fertilized when incubated in treatment 3 (91% +/- 3.0) than in 2 (84% +/- 3.0), 4 (40% +/- 3.0), 5 (77% +/- 3.0) or 1 (76% +/- 3.0). As in previous studies, this study suggests that RCA-1 lectin enhances binding of UTF-derived OPN to bovine oocytes, resulting in increased sperm-egg binding and fertilization in vitro and a possible role in fertilization.
Resumo:
The present study was conducted to determine the affect of pre-treating of oocytes and/or sperm with a rabbit polyclonal antibody against recombinant cattle lipocalin type prostaglandin D synthase (alpha L-PGDS) on in vitro sperm-oocyte binding and fertilization. In vitro matured cattle oocytes were incubated (39 degrees C, 5% CO2 in air) for I It in the following treatments either 500 mu L of fertilization medium (FM) or FM with alpha L-PGDS (1:2000). Frozen-thawed spermatozoa were washed by a 45/90% layered Percoll gradient centrifugation and incubated for I h either FM or FM with a L-PGDS. This study utilized five different treatments: (1) no antibody (control); (2) a rabbit IgG against a non-bovine antigen, bacterial histidase (alpha-hist); (3) a L-PGDS at fertilization time (with fertilization medium); (4) alpha L-PGDS-treated oocytes; or (5) a L-PGDS-treated sperm. Pre-treated oocytes were incubated with 10 X 10(4) washed spermatozoa per 25 oocytes. Oocytes used to assess sperm binding were stained with Hoescht 33342, and the number of sperm bound per zonae pellucidae counted. The remaining oocytes were fixed in acid alcohol, stained with 1% acetate-orcein and observed to determine the presence of pronuclei. More sperm bound to the zonae pellucidae when oocytes and/or sperm were pre-treated with alpha. L-PGDS: (1) 26.4 +/- 3.0; (2) 25.6 +/- 3.0; (3) 59.7 +/- 3.0; (4) 56.4 +/- 3.0; and (5) 57.1 +/- 3.0. Addition of alpha L-PGDS with sperm, oocytes, or both, decreased fertilization (P < 0.05) compared with the control: (1) 89.2 +/- 2.0%; (2) 87.5 +/- 2.0%; (3) 19.4 +/- 2.0%; (4) 27.2 +/- 3.1%; and (5) 14.1 +/- 3.4%. The alpha L-PGDS reacts with both oocytes and spermatozoa, resulting in increases of in vitro sperm-oocyte binding and inhibition of fertilization. These observations suggest that L-PGDS may have a role in cattle fertilization. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
Contents The current study examined the protective effects of l-glutamine and cytochalasin B during vitrification of immature bovine oocytes. Oocyte vitrification solution (PBS supplemented with 10% FCS, 25% EG, 25% DMSO and 0.5 m trehalose) was the vitrification control. Treatments were the addition of 7 mu g/ml cytochalasin B, 80 mm glutamine or both cytochalasin and glutaminine for 30 s. After warming, oocytes were matured in vitro for 24 h, fixed and stained with Hoechst (33342) for nuclear maturation evaluation. l-glutamine improved the vitrified/warmed immature bovine oocytes viability (32.8%), increasing the nuclear maturation rates compared to other treatments and the no treatment vitrified control (17.4%). There was, however, no effect of cytochalasin B on in vitro maturation (14.4%).
Resumo:
The objectives of this investigation were to understand transplacental transport of iron by secreted uteroferrin (UF) and haemophagous areas of water buffalo placenta and clarify the role(s) of blood extravasation at the placental-maternal interface. Placentomes and interplacentomal region of 51 placentae at various stages of gestation were fixed, processed for light and transmission electron microscopy, histochemistry and immunohistochemistry. Haemophagous areas were present in placentomes collected between 4 and 10 months of pregnancy. Perl`s reaction for ferric iron was negative in placentomes, but positive in endometrial glands. Positive staining for UF indicated areas in which it was being taken up by phagocytosis and/or fluid phase pinocytosis in areolae of the interplacentomal mesenchyme, with little staining in endometrial stroma. Imunohistochemistry detected UF in trophectoderm of haemophagous regions of placentomes and in other parts of the foetal villous tree, but the strongest immunostaining was in the epithelial cells and lumen of uterine glands. Ultrastructural analyses indicated that erythrophagocytosis was occurring and that erythrocytes were present inside cells of the chorion that also contained endocytic vesicles and caveolae. Results of this study indicate that both the haemophagous areas of placentomes and the areolae at the interface between chorion and endometrial glands are important sites for iron transfer from mother to foetal-placental tissues in buffalo throughout pregnancy.