The melatonin action on stromal stem cells within pericryptal area in colon cancer model under constant light

Constant light (LL) is associated with high incidence of colon cancer. MLT supplementation was related to the significant control of preneoplastic patterns. We sought to analyze preneoplastic patterns in colon tissue from animals exposed to LL environment (14 days; 300 lx), MLT-supplementation (10 mg/kg/day) and DMH-treatment (1,2 dimethylhydrazine; 125 mg/kg). Rodents were sacrificed and MLT serum levels were measured by radioimmunoassay. Our results indicated that LL induced ACF development (p < 0.001) with a great potential to increase the number of CD133(+) and CD68(+) cells (p < 0.05 and p < 0.001). LL also increased the proliferative process (PCNA-Li; p < 0.001) as well as decreased caspase-3 protein (p < 0.001), related to higher COX-2 protein expression (p < 0.001) within pericryptal colonic stroma (PCCS). However, MLT-supplementation controlled the development of dysplastic ACF (p < 0.001) diminishing preneoplastic patterns into PCCS as CD133 and CD68 (p < 0.05 and p < 0.001). These events were relative to decreased PCNA-Li index and higher expression of caspase-3 protein. Thus, MLT showed a great potential to control the preneoplastic patterns induced by LL. (C) 2011 Elsevier Inc. All rights reserved.

High CO(2)/H(+) dialysis in the caudal ventrolateral medulla (Loeschcke`s area) increases ventilation in wakefulness

Central chemoreception, the detection of CO(2)/H(+) within the brain and the resultant effect on ventilation, was initially localized at two areas on the ventrolateral medulla, one rostral (rVLM-Mitchell`s) the other caudal (cVLM-Loeschcke`s), by surface application of acidic solutions in anesthetized animals. Focal dialysis of a high CO(2)/H(+) artificial cerebrospinal fluid (aCSF) that produced a milder local pH change in unanesthetized rats (like that with a similar to 6.6 mm Hg increase in arterial P(CO2)) delineated putative chemoreceptor regions for the rVLM at the retrotrapezoid nucleus and the rostral medullary raphe that function predominantly in wakefulness and sleep, respectively. Here we ask if chemoreception in the cVLM can be detected by mild focal stimulation and if it functions in a state dependent manner. At responsive sites just beneath Loeschcke`s area, ventilation was increased by, on average, 17% (P < 0.01) only in wakefulness. These data support our hypothesis that central chemoreception is a distributed property with some sites functioning in a state dependent manner. (C) 2010 Elsevier B.V. All rights reserved.

Genetic and environmental factors affecting ultrasound measures of longissimus muscle area and backfat thickness in Nelore cattle

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.

Co-Expression of Leptin and Oestrogen Receptors in the Preoptic-Hypothalamic Area

The interaction between the reproductive axis and energy balance suggests that leptin acts as a possible mediator. This hormone acts in the regulation of metabolism, feeding behaviour and reproduction. Animals homozygous for the gene `ob` (ob/ob) are obese and infertile, and these effects are reversed after systemic administration of leptin. Thus, the present study aimed to determine: (i) whether cells that express leptin also express oestrogen receptors of type-alpha (ER-alpha) or -beta (ER-beta) in the medial preoptic area (MPOA) and in the arcuate (ARC), dorsomedial (DMH) and ventromedial hypothalamic nucleus and (ii) whether there is change in the gene and protein expression of leptin in these brain areas in ovariectomised (OVX) animals when oestrogen-primed. Wistar female rats with normal oestrous cycles or ovariectomised oestrogen-primed or vehicle (oil)-primed were utilised. To determine whether there was a co-expression, immunofluorescence was utilised for double staining. Confocal microscopy was used to confirm the co-expression. The technique of real-time polymerase chain reaction and western blotting were employed to analyse gene and protein expression, respectively. The results obtained showed co-expression of leptin and ER-alpha in the MPOA and in the DMH, as well as leptin and ER-beta in the MPOA, DMH and ARC. However, we did not detect leptin in the MPOA, ARC and DMH using western blotting and there was no statistical difference in leptin gene expression in the MPOA, DMH, ARC, pituitary or adipose tissue between OVX rats treated with oestrogen or vehicle. In conclusion, the results obtained in the present study confirm that the brain is also a source of leptin and reveal co-expression of oestrogen receptors and leptin in the same cells from areas related to reproductive function and feeding behaviour. Although these data corroborate the previous evidence obtained concerning the interaction between the action of brain leptin and reproductive function, the physiological relevance of this interaction remains uncertain and additional studies are necessary to elucidate the exact role of central leptin.

Protein requirements for Blue-fronted Amazon (Amazona aestiva) growth

The objective of this study was to evaluate the protein requirements for hand-rearing Blue-fronted Amazon parrots (Amazona aestiva). Forty hatchlings were fed semi-purified diets containing one of four (as-fed basis) protein levels: 13%, 18%, 23% and 28%. The experiment was carried out in a randomized block design with the initial weight of the nestling as the blocking factor and 10 parrots per protein level. Regression analysis was used to determine relationships between protein level and biometric measurements. The data indicated that 13% crude protein supported nestling growth with 18% being the minimum tested level required for maximum development. The optimal protein concentration for maximum weight gain was 24.4% (p = 0.08; r(2) = 0.25), tail length 23.7% (p = 0.09; r(2) = 0.19), wing length 23.0% (p = 0.07; r(2) = 0.17), tarsus length 21.3% (p = 0.06; r(2) = 0.10) and tarsus width 21.4% (p = 0.07; r(2) = 0.09). Tarsus measurements were larger in males (p < 0.05), indicating that sex must be considered when studying developing psittacines. These results were obtained using a highly digestible protein and a diet with moderate metabolizable energy levels.

Canine infection by Rickettsiae and Ehrlichiae in southern Brazil

This study evaluated the infection caused by Rickettsia and Ehrlichia agents among dogs in southern Brazil. A total of 389 dogs were tested by the indirect immunofluorescence assay (IFA) for Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommii, Rickettsia rhipicephali, Rickettsia bellii, and Ehrlichia canis. Overall, 42.4% (165/389) of the dogs were seroreactive to at least one Rickettsia species, but only 11 canine sera reacted with another Rickettsia species without reacting with R. parkeri. A total of 100 (25.7%) canine sera showed titers to R. parkeri at least 4-fold higher than those to any of the other rickettsial antigens, allowing us to consider that these dogs were infected by R. parkeri. Dogs that had direct contact with pasture or forest areas were > 2 times more likely to be seroreactive to Rickettsia than dogs with no such direct contact. Only 19 (4.8%) of the 389 dogs were seroreactive to E. canis.

Ticks (Acari : ixodidae) infesting wild birds in an Atlantic forest area in the state of Sao Paulo, Brazil, with isolation of Rickettsia from the tick Amblyomma longirostre

During field work in Nazare Paulista, state of Sao Paulo, Brazil, we found 13 (56.5%) of 23 birds (mostly Passeriformes) to be infested by 28 larvae and I nymph of Amblyomma spp. Two larvae were reared to the adult stage, being taxonomically identified as Amblyomma parkeri Fonseca and Aragao, whereas five larvae and one nymph were identified as Amblyomma longirostre Koch. All six A. longirostre specimens were shown to be infected by rickettsia, as demonstrated by polymerase chain reaction (PCR) targeting two rickettsial genes (gltA and ompA) or isolation of rickettsia in cell culture from one of the ticks. This isolate was designated as strain AL, which was established in Vero cell culture and was molecularly characterized by DNA sequencing fragments of the rickettsial genes gltA, htrA, ompA, and ompB. Phylogenetic analyses inferred from ompA and ompB partial sequences showed a high degree of similarity of strain AL with Rickettsia sp. strain ARANHA, previously detected by PCR in A. longirostre ticks from Rondonia, northern Brazil. We conclude that strain AL is a new rickettsia genotype belonging to the same species of strain ARANHA, which are closely related to Candidatus `R. amblyomniii`. Further studies should elucidate if strains AL and ARANHA are different strains of Candidatus `R. amblyommii` or are a new species.

Rickettsial infections of dogs, horses and ticks in Juiz de Fora, southeastern Brazil, and isolation of Rickettsia rickettsii from Rhipicephalus sanguineus ticks

The present study was performed in an area endemic for Brazilian spotted fever (BSF) in Juiz de Fora, state of Minas Gerais, Brazil, during the years 2007 and 2008, when fatal cases of BSF (caused by Rickettsia rickettsii) were reported. Adult ticks (Acari: Ixodidae) identified as Rhipicephalus sanguineus (Latreille) and Amblyomma cajennense (Fabricius) were collected from dogs and horses, respectively, and tested by polymerase chain reaction (PCR). Overall, 13.1% of the Rh. sanguineus ticks and none of the A. cajennense were found to be infected with R. rickettsii. Two isolates of R. rickettsii were successfully established in Vero cell culture from two Rh. sanguineus ticks. An indirect immunofluorescence assay (IFA) using R. rickettsii antigens detected blood serological reaction to R. rickettsii in 67.9% (53/78) of dogs and 41.0% (16/39) of horses living in the study area. Larval offspring from two Rh. sanguineus engorged females, naturally infected by R. rickettsii, were reared to adult stage in the laboratory. All active stages (larvae, nymphs, adults) remained 100% infected by R. rickettsii, which was efficiently transmitted to naive rabbits. Overall, the results of the present study indicate a potential risk for transmission of R. rickettsii to humans by Rh. sanguineus, an occurrence yet to be documented in Brazil.

Genotyping of Toxoplasma gondii isolates from free range chickens in the Pantanal area of Brazil

The aim of this paper was to genetically characterize Toxoplasma gondii isolates from free range chickens in regions of Brazilian territory in the state of Mato Grosso do Sul (MS) where T. gondii strains have never been studied. In total, T. gondii isolates from 22 free range chickens were included in this study. Fifty chickens from Eldorado, thirty from Rio Verde and ten from Aquidauana were sampled between January and April 2007. In relation to the genetic diversity of T. gondii isolates from chickens in MS, the magnitude of the diversity in the isolates sampled in this study was comparable to the overall diversity in a composite data set. These 22 isolates in MS revealed 11 genotypes, whereas the 321 isolates ever genotyped in Brazil have revealed 95 genotypes. The values of Simpson`s Diversity Index for the whole population of T. gondii isolates in Brazil, the whole population of T. gondii isolates from chickens in Brazil and the population surveyed in this study were 0.97, 0.95 and 0.90, respectively. Seven of the 11 genotypes revealed from chicken isolates from MS are newly described genotypes and six of them each have a single isolate. In conclusion, the results obtained from isolates in MS corroborate previous studies on T. gondii isolates in Brazil, thus confirming their diversity and atypicality. Nonetheless, the applicability of PCR-RFLP markers for epidemiological inferences remains controversial. (c) 2011 Elsevier B.V. All rights reserved.

Occurrence of antibodies anti-Neospora caninum, anti-Toxoplasma gondii, and anti-Leishmania chagasi in serum of dogs from Para State, Amazon, Brazil

A cross-sectional study was conducted to determine the occurrence of anti-Toxoplasma gondii, anti-Neospora caninum, and anti- Leishmania chagasi antibodies in dogs of the state of Para, Brazil. For this purpose, 129 blood samples were collected from dogs of different ages and gender. Samples of 72 dogs were collected from 39 rural properties from 19 municipalities, and 57 samples were from stray dogs, collected after captivity by the Center of Zoonosis Control from the municipality of Santar,m. The sera were analyzed for anti-T. gondii and anti-N. caninum antibodies by indirect fluorescent antibody tests with cutoff values of 1:16 and 1:50, respectively. For the presence of L. chagasi antibodies, enzyme-linked immunosorbent assay was used and positive results were confirmed by immunochromatographic method using the recombinant antigen K39. Of the total of 129 dogs, 90 (69.8%) were positive for T. gondii, 16 (12.4%) for N. caninum, and 30 (23.3%) for L. chagasi. Antibodies for all three parasites were found simultaneously in seven dogs (5.4%), mostly in urban dogs (six of seven). No association was observed related to gender and location (urban or rural) of dogs and occurrence of N. caninum and T. gondii antibodies although, regarding L. chagasi, higher prevalence was found in females (P < 0.02) and in dogs from urban location (P < 0.001). From the 39 farms, in 30 (76.9%) at least one dog was positive for T. gondii or N. caninum or both. Higher occurrence of Leishmania antibodies was observed in N. caninum-negative dogs (P < 0.05).

Impacts of Animal Traffic on the Brazilian Amazon Parrots (Amazona species) Collection of the Quinzinho de Barros Municipal Zoological Park, Brazil, 1986-2007

Eleven species of Amazon parrots (genus Amazona) are known to occur in Brazil, and nest poaching and illegal traffic pose serious conservation threats to these species. When the illegal owners realize these animals are incompatible with their expectations and lifestyle, or when the police arrests traders and owners, these trafficked animals are often considered unfit for release and sent to local zoos and captive breeders. A retrospective survey of animal and necropsy records from 1986 to 2007 was used to evaluate the impacts of animal traffic on the population composition and mortality patterns of Amazon parrots at the Quinzinho de Barros Municipal Zoological Park, Sorocaba, Brazil. Data were obtained for 374 Amazon parrots of ten Brazilian species, and there was evidence that the studied population could be split into two major groups: a majority belonging to the Amazona aestiva species and a minority belonging to the remaining species. In comparison, the animals of the first group were more frequently admitted from traffic-related origins (98 vs. 75%), had a shorter lifespan (median 301 days vs. 848 days) and a higher mortality within the first year postadmission (54 vs. 37%), were less likely to receive expensive treatments, and were more frequently housed off-exhibit. On an average, parrots were found to have a short postadmission lifespan (median 356 days), with 92.5% of the birds dying within their first five years in captivity. The paper discusses the difficult dilemmas these incoming traffic-related animals pose to zoo management and official anti-traffic policies. Zoo Biol 29:600-614, 2010. (C) 2010 Wiley-Liss, Inc.

The Importance of Adhesive Area Delimitation in a Microshear Bond Strength Experimental Design

Purpose: The purpose of this study was to assess the influence of adhesive area delimitation on the microshear bond strength of different adhesives to dentin. Materials and Methods: Eighteen bovine incisors were sectioned and the exposed dentin surfaces were prepared with 600-grit SIC paper. These teeth were randomly divided into three groups, according to the adhesive to be applied: two-step etch-and-rinse Adper Single Bond 2 (3M ESPE), two-step self-etching Clearfil SE Bond (Kuraray), and one-step Clearfil S(3) Bond (Kuraray). On each dentin surface, 4 samples were built up with the composite resin Z100 (3M ESPE); on 2 of these, a suggested area delimitation technique was employed. After 24 h of storage in water at 37 degrees C, samples were subjected to the microshear bond strength test, and the failure modes were evaluated under optical and scanning electron microscopes. The obtained results were statistical analyzed using two-way ANOVA and Tukey`s test. Results: Groups without area delimitation presented significantly higher bond strength results (p < 0.05) and a higher incidence of cohesive failures. In these groups, fractures tended to occur beyond the limits of the actual adhesive area, while the area restriction technique succeeded in avoiding this phenomenon. The three adhesives performed similarly when area delimitation was employed (p > 0.05), but Clearfil S(3) Bond showed significantly higher bond strength results when no area delimitation was taken into account (p < 0.05). Conclusion: The extension of the adhesive area beyond the limits of the composite cylinder may play an important role in the results of microshear bond strength tests, while the suggested area delimitation technique may lead to less questionable outcomes.

Squamous Cell Carcinoma of the Tongue and Floor of the Mouth: Analysis of Survival Rate and Independent Prognostic Factors in the Amazon Region

Oral squamous cell carcinoma (OSCC) accounts for more than 95% of all malignant neoplasms in the oral cavity. Although several studies have shown the epidemiology of this cancer in Brazil, there do not seem to be any studies that describe the prognostic factors related to OSCC in the Amazon region. Therefore, the aim of this study was to determine the survival rate and prognostic significance of different factors in patients from this region affected by OSCC. Data from 85 patients with histologically confirmed squamous cell carcinoma of the tongue and floor of the mouth identified from the Ofir Loyola Hospital archives were collected and analyzed using univariate (log-rank test) and multivariate (Cox proportional hazard model) tests. The overall 5-year survival rate was found to be 27%. Univariate analysis showed that the 5-year survival rate was significantly higher for younger (<= 45 y) female patients, patients with T1-2 tumors and clinically clear neck nodes (N0), patients with early stage cancers (AJCC stage I-II), and patients treated with surgical procedures. However, multivariate analysis showed that the 5-year survival rate was significantly higher only in the younger patients and those who underwent surgical treatment. The age of the patient at the moment of diagnosis and treatment with surgical procedures were the only independent prognostic factors that affected the 5-year survival rate of the patients in this region.