Cytogenetical aspects of testicular cells in economically important species of coreidae family (Heteroptera)

Some cytogenetical aspects of spermatozoa formation were studied in 9 Coreidae Brazilian species: Anasa bellator, Athaumastus haematicus, Chariesterus armatus, Dallacoris obscura, Dallacoris pictus, Leptoglossus gonagra, Leptoglossus zonatus, Sphictyrtus fasciatus, and Zicca annulata. Similarly to the other species described to date, all the species studied herein showed cystic spermatogenesis, a reddish membrane covering the testes, a X0 sex determining system, a pair of m-chromosomes, intersticial chiasmata in most autosomes, and autosomes dividing reductionally at first meiotic division and equationally in the second 1 while sex chromosomes, divide equationally and reductionally at first and second meiotic division, respectively. In addition, it was observed that the sex chromosome is heteropycnotic at prophase and that heteropycnotic chromosomal material is found in the nuclei at spermiogenesis. In the species studied, the diploid chromosome number ranged from 19 to 25. It was 19 in S. fasciatus (16A+2m+X0); 21 in A. bellator, A. haematicus, D. obscura, D. pictus, L. gonagra, and L. zonatus (18A+2m+X0); 23 in Z. annulata (20A+2m+X0); and 25 in C. armatus (22A+2m+X0). © 2007 The Japan Mendel Society.

On the study of the dynamical aspects of parasitemia in the blood cycle of malaria

Malaria is an important cause of morbidity and mortality worldwide. One striking aspect regarding malaria is the fact that individuals living in endemic areas do not develop immunity against the parasite, falling ill whenever they are exposed tothe parasite. The understanding of why immunity is not developed in the usual way against Plasmodium is crucial to the improvement of treatment and prevention. In this work, we study some aspects of the dynamics of the blood cycle of malaria using both modelling and data analysis of observed case-histories described by parasitemia time series. By comparing our simulations with experimental results we have shown that the different behaviour observed among patients may be associated to differences in the efficiency of the immune system to control the infection. © EDP Sciences/Societa Italiana di Fisica/Springer-Verlag 2007.

Biological aspects of Amblyomma brasiliense (Acari: Ixodidae) under laboratory conditions

Although Amblyomma brasiliense Aragão 1908 has been reported as one of the most aggressive ticks to humans in Brazil, information about the biology of this tick species is virtually inexistent. This work reports data on the life cycle of A. brasiliense fed on rabbits and pigs and maintained in an incubator at 20°C, 90% RH and 12 h of light for off-host development. Tick yield of adult females fed on pigs and rabbits was 81.2% and 58.3%, respectively. Females fed on pigs had mean engorgement weight of 862.3 mg and egg mass of 208 mg, while females fed on rabbits had mean engorgement weight of 606.1 mg and egg mass of 160 mg; these values did not differ statistically between host species. Feeding period of female ticks fed on pigs (10 days) was significantly shorter than that on rabbits (17 days). Mean preoviposition period was slightly longer (35.9 days) for ticks fed on pigs than on rabbits (30 days). The minimum incubation period of eggs of ticks from both host species was similar and over 100 days. Egg production efficiency was low for females fed on both hosts (less than 30% and 20% for ticks from pigs and rabbits, respectively). More than 55% of larvae and 79% of nymphs fed on rabbits, set free inside the feeding chambers, engorged successfully. These ticks attained an engorgement weight of 1.3 and 18.2 mg, respectively, and fed for approximately 5 days. The minimum pre-molt period was 30 days for engorged larvae and over 44 days for nymphs. Molting success was low, less than 50% in the case of larvae and less than 20% for nymphs. Further studies are required to better determine the off-host requirements of this tick species. © 2008 Springer Science+Business Media B.V.

Clinical and immunological aspects of newcastle disease vaccination in budgerigars (Melopsittacus undulatus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bovine abortion associated with Neospora caninum: Diagnosis and epidemiological aspects of a dairy cattle herd in the northeast region of São Paulo state, Brazil

The objective of this study was to report the presence of Neospora caninum-associated abortion in bovines at a farm in the northeast region of São Paulo State. In January 2010, it was sent to the Department of Pathology, UNESP-Jaboticabal, a bovine fetus with an estimated age of seven months, which was natural of a dairy farm with 300 animals and an average daily production of 3,000 liters of milk, nearly 20 liters per cow. The animals were vaccinated against rabies, foot and mouth disease, carbuncle, brucellosis, leptospirosis, bovine herpes virus type I and bovine viral diarrhea virus. The herd consisted of purebred Holstein animals, Jersey, and mostly by crossbred animals 7-8 (gir x holstein). During necropsy, samples of the serosanguineous liquid present at the thoracic cavity and the heart of the fetus were collected for the detection of anti-Neospora caninum antibodies through Indirect Immunofluorescence Assay (IFA). Fragments of brain, cerebellum, tongue, liver, heart and kidneys were collected for the execution of histopathology (HP), immunohistochemistry (IHC) and Polymerase Chain Reaction. In order that IFA could be performed, the owner was requested blood samples without anticoagulants of the mother and other cows in the farm, with or without a history of abortion. At necropsy, it was verified a severe autolysis of the fetus. The serology of the fetus was 1:25, while the serology of the mother was 1:3,200. At HP, it was observed discrete multifocal non-suppurative encephalomyelitis characterized by gliosis and mononuclear inflammatory infiltration associated with cellular debris. DNA amplification of N. caninum was positive in fragments of brain, tongue, cerebellum, heart and kidneys. At IHC, it has been observed immunoreactivity to a cyst located in the tongue. The owner reported that his herd showed endemic episodes of abortion, while 27.69% (18/65) of the 65 animals sampled were seropositive. Although it has not been a significant difference (p>0.05), a higher seropositivity was observed in animals with a history of abortion (10/26) 38.46%, in comparison with animals without previous abortion (8/39) 20.51%. These findings show that the abortion under study was provoked by the protozoan N. caninum, while this is the first report concerning cattle in the northeast region of São Paulo State.

Chagas disease and triatomine biology (Heteroptera, Triatominae), with emphasis on aspects of spermatogenesis

A century after the discovery of Chagas disease, it is still one of the most important parasitic diseases affecting humans. The subfamily Triatominae is important in medical health, because these insects are vectors of Trypanosoma cruzi, the etiologic agent of Chagas disease. These insects are also of important cytological relevance because they have particular cell characteristics, such as persistence of nucleolar material in spermatogenesis. The germ cells of the animal kingdom have chromatoid bodies (CBs) in their cytoplasm that can originate from nucleolar material that is fragmented in the early stages of spermatogenesis and plays an important role in cellular communication between the spermatids during spermiogenesis. Currently, there are few studies on the function and formation of the CB in nucleologenesis, especially with emphasis on the ultrastructure of the cells involved in spermatogenesis of insects. Considering the importance of knowledge about the triatomine fauna, we conducted a study of the biogeography and reports of these insects and a survey of patients with Chagas disease in the northwestern region of São Paulo State. Data collected from 1995 to 2009 indicated 700 individuals with Chagas disease, demonstrating a range of 0 to 40 years, which shows that the disease may be active in this region. Moreover, of the 1150 patients treated for cardiomyopathy, 44% were chagasic. Regarding the triatomines noted and captured in the period from 2004 to 2009, the species were Triatoma sordida and Rhodnius neglectus, with T. sordida being the most abundant. In addition, some triatomines were infected by T. cruzi in various developmental stages. We also analyzed the nucleolar cycle and fibrillarin nucleolar protein expression in CB of spermatogenic cells of T. infestans and T. sordida, using histological, ultrastructural and immunocytochemical techniques. The results revealed fibrillarin nucleolar protein expression in the nucleus and in some cytoplasmic spots of germ cells during spermatogenesis in triatomines. These data suggest that fibrillarin could be a constituent of CB, which was most likely derived from nucleolar fragmentation. This is the first time that fibrillarin protein expression has been shown in CB during spermatogenesis progression in triatomines. Knowledge about the biology of triatomines was deepened in this study and, in particular, the structural and ultrastructural aspects of spermatogenesis in triatomines. This study showed that the disease may be active in the northwestern region of São Paulo and expanded our knowledge of the biology of triatomines, the main vectors of Chagas disease. © FUNPEC-RP.

Biologic and genetics aspects of chagas disease at endemic areas

The etiologic agent of Chagas Disease is the Trypanosoma cruzi, transmitted through blood-sucking insect vectors of the Triatominae subfamily, representing one of the most serious public health concerns in Latin America. There are geographic variations in the prevalence of clinical forms and morbidity of Chagas disease, likely due to genetic variation of the T. cruzi and the host genetic and environmental features. Increasing evidence has supported that inflammatory cytokines and chemokines are responsible for the generation of the inflammatory infiltrate and tissue damage. Moreover, genetic polymorphisms, protein expression levels, and genomic imbalances are associated with disease progression. This paper discusses these key aspects. Large surveys were carried out in Brazil and served as baseline for definition of the control measures adopted. However, Chagas disease is still active, and aspects such as host-parasite interactions, genetic mechanisms of cellular interaction, genetic variability, and tropism need further investigations in the attempt to eradicate the disease. Copyright 2012 Marilanda Ferreira Bellini et al.

Morphological aspects of the liver of the Podocnemis expansa (Testudines, podocnemididae)

The liver of P. expansa was characterized morphohistologically. To this end, twenty livers from clinically healthy male and female Podocnemis expansa, weighing from 2.0 to 4,5 kg, supplied by the commercial breeder Fazenda Moenda da Serra, in Araguapaz, state of Goiás, Brazil, were analyzed macro-and microscopically. The coelomatic cavity was opened and the topography of the fresh organs was examined visually. After the histological preparation, the slides were stained with Hematoxylin and Eosin (HE), Periodic Acid-Schiff (PAS), Gomori Trichrome, Reticulin and Picrosirius. The liver of P. expansa is a voluminous organ with an approximately rectangular shape and brown coloration, varying from light to dark shades, and is divided into a right lobe, left lobe, and a central portion. The right lobe is the largest of the three portions. The gall bladder is located in a depression in the caudal portion of the right lobe, where the gall duct begins and empties into the duodenum. Histologically, the hepatocytes are arranged in the form of double cords surrounded by winding sinusoidal capillaries. In cross section, they resemble acini containing approximately two to five hepatocytes surrounding a probable central biliary canaliculus. The hepatocytes are polyhedral or pyramidal in shape, of uniform size, with a few central nuclei and others displaced peripherally, and the cytoplasm is little eosinophilic when analyzed by the HE staining technique. The parenchyma is supported by delicate reticular fibers surrounding hepatocytes and sinusoids. The parenchyma and perisinusoidal spaces contain large quantities of melanomacrophages, mainly close to the portal spaces.

Some aspects of chicken behavior and welfare

Brazil is the world leader in broiler production and export. It achieved this position mainly to its excellent supply chain structure and climate, which favor poultry and grain production throughout its territory. Although Brazilian egg production is not as important as broiler production, this segment presents great potential of increasing its share in the global market. However, as elsewhere in the world, Brazilian poultry production faces the challenge to balance two elements within its supply chain: cruelty and productivity. The consumers of the European Union (EU) are very concerned with animal welfare issues. In order to increase its share in the European market, and eventually in the world market, Brazilian poultry producers must understand the effects of production systems on poultry welfare, and try to develop systems that are suited for its climate and other production conditions. There is a consensus that the natural behaviors performed by poultry in intensive production systems allow better welfare. This objective of this review is to present scientific research studies that relate different behaviors to chicken welfare. Poultry behavior is a reflex of their welfare status at a particular moment, and it is related to internal (physiological) and external (environmental) factors. Several natural behaviors that favor welfare, as well as undesirable behaviors, may be stimulated by environmental enrichment. The correct interpretation of the behaviors expressed by poultry, including their frequency, duration, and sequence, may be used to estimate their welfare. Animal production is an import sector of Brazilian economy. It significantly contributes to the Gross Domestic Product (GDP), in terms of products destined both to domestic consumption and exports. New technologies applied to products and management practices have been developed for field application, aiming at improving producers' productivity and profitability. In order to comply with the European Union's (EU) guidelines for animal protein production, Brazilian poultry production needs to undergo a process of adaptation. In May, 2007, the EU Commission established its new guidelines for animal welfare in poultry production, pressured by consumer demand. In the EU, there is a growing concern among consumers as to how poultry are reared and slaughtered. European consumers are in the fore front of the demand of high quality products produced with under better welfare conditions, and have spread this concern throughout the world. Beaumont et al. (2010) mentioned that European consumers frequently perceive that standard commercial poultry production has poor animal welfare practices. According to Nääs et al. (2008), Brazilian poultry production today needs to find a balance between cruelty and productivity. In fact, ensuring animal welfare may provide better financial results, as it increases the producer's profit margins and allows maintaining Brazilian chicken export quotas to the EU. França (2008) noted that biological studies that define ethical limits and guidelines for poultry production foster the development of new production practices that may ensure good product quality and productivity without putting bird welfare at risk. Gonyou (1994) states that, when animal welfare started to be studied, the only behavioral factors considered were those related to feeding and reproduction. These first studies used as indicators of animal welfare reduced life expectancy, impaired growth, impaired reproduction, body damage, disease, immunosuppression, adrenal activity, behavior anomalies, and self-narcotization (Broom, 1991). However, current studies evaluate additional indicators, such as natural behaviors, behavioral needs, preferences, behavioral problems, emotional state, cognitive abilities, etc. In the field of ethology, the expression of natural behavior is a frequently used tool used to estimate the welfare of poultry destined to human consumption. According to Bracke & Hopster (2006), natural behavior can be defined as the behavior the animal normaly presents when exposed to conditions similar to its natural habitat. Natural behaviors are pleasurable and promote biological functions that are meaningful to the animal's welfare. The definition of natural behavior, though, does not include the bird's behavior when sick, in flight or during aggression, since these are not considered pleasurable situations. Considering layer behavioral needs in the design of housing facilities optimize their welfare. Mishra et al. (2005) verified that ISA Brown layers spent, during 24 hours, around 97% of the time in the nest, feeding, walking, resting, or dust bathing, and that 57% of these behaviors did not depend on environmental enrichment. It was also observed that hens had preferred behavioral sequences, which included foraging and comfort behaviors, such as wing-stretching and preening. The present review aims at discussing, albeit not exhaustively, scientific research studies on the behavior of Gallusgallus domesticus and its relationship to welfare. The following behaviors are reviewed: feather pecking, scratching, dust bathing, nesting, locomotion activities, and aggressive behaviors. These behaviors are the most frequently observed in commercial broiler, broiler breeder, and layer farming, and therefore, monitoring their incidence may contribute to measure poultry welfare.

At least two indigenous species of the Bemisia tabaci complex are present in Brazil

Bemisia tabaci is one of the most important global agricultural insect pests, being a vector of emerging plant viruses such as begomoviruses and criniviruses that cause serious problems in many countries. Although knowledge of the genetic diversity of B. tabaci populations is important for controlling this pest and understanding viral epidemics, limited information is available on this pest in Brazil. A survey was conducted in different locations of São Paulo and Mato Grosso states, and the phylogenetic relationships of B. tabaci individuals from 43 populations sampled from different hosts were analysed based on partial mitochondrial cytochrome oxidase 1 gene (mtCOI) sequences. According to the recently proposed classification of the B. tabaci complex, which employs the 3.5% mtCOI sequence divergence threshold for species demarcation, most of the specimens collected were found to belong to the Middle East-Asia Minor 1 species, which includes the invasive populations of the commonly known B biotype, within the Africa/Middle East/Asia Minor high-level group. Three specimens collected from Solanun gilo and Ipomoea sp. were grouped together and could be classified in the New World species that includes the commonly known A biotype. However, six specimens collected from Euphorbia heterophylla, Xanthium cavanillesii and Glycine maxima could not be classified into any of the 28 previously proposed species, although according to the 11% mtCOI sequence divergence threshold, they belong to the New World high-level group. These specimens were classified into a new recently proposed species named New World 2 that includes populations from Argentina. Middle East-Asia Minor 1, New World and New World 2 were differentiated by RFLP analysis of the mtCOI gene using TaqI enzyme. Taq I analysis in silico also differentiates these from Mediterranean species, thus making this method a convenient tool to determine population dynamics, especially critical for monitoring the presence of this exotic pest in Brazil. © 2012 Blackwell Verlag, GmbH.

Eco-physiological aspects of melaleuca seed germination

The invasive behavior of melaleuca (Melaleuca quinquenervia) plants in wetlands is due to its aggressive regeneration strategy, which is based on its seeds germination performance. Understanding of the eco-physiological aspects of the seed germination in melaleuca plants may significantly contribute for the development of management strategies. The objective of this research was to learn how the germination of M. quinquenervia seeds are affected by light and temperature. Melaleuca seeds were placed on filter paper moistened with 12 ml of distilled water at temperatures between 10 and 45°C. Germination was evaluated in dark and light conditions. Seed germination, first count of seed germination (seven days), germination speed index and germination mean time were determined up to 40 days after seeding, when germination had ceased in most of the treatments. After that period, the seeds were transferred to conditions of 30°C and light, which was found to be ideal in the previous phase. Seed germination was daily evaluated up to 63 days when it was again observed no longer to occur. The treatment repetitions were distributed in the growth-chamber according to a completely randomized design in a factorial scheme (eight temperatures x two light conditions) and four repetitions. The data were submitted to analysis of variance with the F test and the means were adjusted to polynomial and non linear regression models. The highest seed germination performance was observed to take place under conditions of 27.3°C with light. The temperatures of 35 and 40°C in the dark induced thermal inhibition of seed germination. The temperature of 45°C was lethal to the seeds.

Phenotypic and metabolic aspects of prostatic epithelial cells in aged gerbils after antisteroidal therapy: Turnover in the state of chromatin condensation and androgen-independent cell replacement

The gerbil is a rodent considered a good model for studies of prostatic morphophysiology under different experimental conditions. Studies involving castration and steroidal blockers of aged gerbils showed that the glandular epithelium persists after long-term therapy, preventing the organ atrophy. Thus, the objective of this study was to evaluate the phenotypic characteristics and behavior of prostatic epithelial cells that remained after different periods of hormone ablation in aged gerbils. The identification of elements that influenced the survival of this cell type was performed by morphometric, nuclear phenotypes, ultrastructural and immune histochemical analysis. The most significant responses to treatment, by analyzing morphometric features, were observed during the first three time points (day 1, day 3, and day 7), after which there appeared to be an adjustment of the gland to the hormone ablation. All treatments led to changes in the state of chromatin condensation, DNA methylation pattern and phenotypic changes indicated cell senescence. Additionally, an increase in the basal cells seemed to guarantee self-renewal properties to the epithelium. These data indicate that changes occur at many levels, including gene expression and nuclear architecture in the epithelial cells, when aging and steroidal blockade are associated. These aspects are important when considering castration-resistant prostate cancer, a malignant tumor posing difficult therapeutic intervention. © 2013 Elsevier GmbH. All rights reserved.

Immunological aspects of fresh-frozen allogeneic bone grafting for lateral ridge augmentation

Objectives: To present some immunological aspects of fresh-frozen allogeneic bone grafting for lateral bone augmentation, based on the quantitative evaluation of IL-10, IL-1β, IFN- γ and TNF- α in patients sera. Material and methods: Thirty-three partially or totally edentulous patients received fresh-frozen allogeneic bone (AL - 20 patients) or autologous bone onlay block grafts (AT - 13 patients) prior to oral implant placement. Blood samples were collected from each patient at various time-points during a 6 month-period (baseline, 14, 30, 90 and 180 days postoperatively). Quantitative evaluation of IL-10, IL-1β, IFN- γ and TNF- α was performed by enzyme linked immunosorbent assay (ELISA). Results: For all evaluated markers and at all evaluated periods, inter-group comparisons showed no statistically significant differences between the groups, while the observed values were within normal levels. For AL-treated patients, intra-group evaluation showed statistically significant increase of TNF-α from baseline to 90 (P < 0.001) and 180 (P < 0.01) days, and from 14 to 90 (P < 0.01) and 180 (P < 0.05) days. IFN- γ showed intercalated results, with a decrease from baseline to 14 days (P < 0.05), and increase from 14 to 90 days (P < 0.001) and 180 (P < 0.05) days. No differences between the periods of evaluation were found for the AT group. Conclusions: AL grafting for lateral bone augmentation, similar to AT grafting, does not seem to challenge the immune system significantly. © 2012 John Wiley & Sons A/S.

On computational aspects of discrete Sobolev inner products on the unit circle

In this paper, we show how to compute in O(n2) steps the Fourier coefficients associated with the Gelfand-Levitan approach for discrete Sobolev orthogonal polynomials on the unit circle when the support of the discrete component involving derivatives is located outside the closed unit disk. As a consequence, we deduce the outer relative asymptotics of these polynomials in terms of those associated with the original orthogonality measure. Moreover, we show how to recover the discrete part of our Sobolev inner product. © 2013 Elsevier Inc. All rights reserved.

Aspects of Mechanical Behavior and Modeling of a Tropical Unsaturated Soil

The research studies the applicability of two elastoplastic models for the collapse prediction of the lateritic soil profile from Southeastern Brazil. These tropical soils have peculiar geotechnical behavior, due to their mineralogical composition and porous structure coming from intense process of formation. Two elastoplastic models were analyzed: the Barcelona Basic Model (BBM) and another one based on BBM, however developed for tropical soils. Oedometric tests with suction control were performed at three distinct depths of the soil profile. The BBM was not suitable for the upper layer of the soil profile, because BBM considers the compressible behavior of the soil in function of the reduction of the elastoplastic compressibility index with the increase of the matric suction. The model developed for tropical soils showed better suited to the compressible behavior of the soil profile, resulting in good prediction of the collapse potential, mainly by accepting increasing values of the elastoplastic compressibility index of the soil profile with the matric suction rise. © 2013 Springer Science+Business Media Dordrecht.