Genome wide scan for quantitative trait loci affecting tick resistance in cattle (Bos taurus × Bos indicus)

Abstract Background In tropical countries, losses caused by bovine tick Rhipicephalus (Boophilus) microplus infestation have a tremendous economic impact on cattle production systems. Genetic variation between Bos taurus and Bos indicus to tick resistance and molecular biology tools might allow for the identification of molecular markers linked to resistance traits that could be used as an auxiliary tool in selection programs. The objective of this work was to identify QTL associated with tick resistance/susceptibility in a bovine F2 population derived from the Gyr (Bos indicus) × Holstein (Bos taurus) cross. Results Through a whole genome scan with microsatellite markers, we were able to map six genomic regions associated with bovine tick resistance. For most QTL, we have found that depending on the tick evaluation season (dry and rainy) different sets of genes could be involved in the resistance mechanism. We identified dry season specific QTL on BTA 2 and 10, rainy season specific QTL on BTA 5, 11 and 27. We also found a highly significant genome wide QTL for both dry and rainy seasons in the central region of BTA 23. Conclusions The experimental F2 population derived from Gyr × Holstein cross successfully allowed the identification of six highly significant QTL associated with tick resistance in cattle. QTL located on BTA 23 might be related with the bovine histocompatibility complex. Further investigation of these QTL will help to isolate candidate genes involved with tick resistance in cattle.

Genetic diversity of the Brazilian Creole cattle Pé-duro assessed by microsatellites and mitochondrial DNA

The objective of this study was to describe the genetic diversity and structure of the largest Pé-duro population by assessing variation at ten autosomal microsatellite (STR) loci and mitochondrial DNA (mtDNA) sequences. The mean expected heterozygosity was 0.755, the mean observed heterozygosity was 0.600 and significant inbreeding coefficient (Fis) and deviations from the Hardy-Weinberg equilibrium in most of analyzed loci demonstrate the impact of inbreeding and homozygosis on this population. A more in-depth genetic analysis could be achieved by expanding the STR list. The analysis of mtDNA provided evidence of ancestral African taurine haplotypes in Pé-duro and excluded maternal Zebuine introgression. In this report, the main Pé-duro population is genetically portrayed by sampling approximately 40% of it. As this herd represents the core of the Pé-duro conservation program, these findings are of outstanding value for the management and preservation of this Brazilian 'native' cattle breed.

First report of Trypanosoma vivax outbreak in dairy cattle in São Paulo state, Brazil

This is the first description of a Trypanosoma vivax outbreak in the state of São Paulo (municipality of Lins). Fever, jaundice, decreased milk production, weight loss, profuse diarrhea, abortion, anemia, leukocytosis and hyperfibrinogenemia were observed in the affected animals. Thirty-one cows and calves died out of a total of 1080 in the herd. Three cows showed neurological symptoms like dysmetria, ataxia, muscle weakness, ptyalism, lymph node enlargement and submandibular edema. Flagellated hemoparasites were observed in blood smears. The species was diagnosed as T. vivax by means of PCR. This T.vivax strain showed resistance to diaminazene aceturate and the infection spread quickly at the herd. From the ELISA test, 599 serum samples (98.36%) were positive for anti-T.vivax IgG antibodies. This outbreak occurred during a very dry period, which indicates that other factors were involved in the outbreak, such as absence of tabanids and large populations of Haematobia irritans and Stomoxys calcitrans. The increases in these populations may have been due to the use of biosolid waste from sugar and ethanol plants in the sugarcane plantations surrounding the dairy farm.

Comparative study by computed radiography, histology, and scanning electron microscopy of the articular cartilage of normal goats and in chronic infection with caprine arthritis-encephalitis virus

In the northeast of Brazil, caprine arthritis-encephalitis (CAE) is one of the key reasons for herd productivity decreasing that result in considerable economic losses. A comparative study was carried out using computed radiography (CR), histological analysis (HA), and scanning electronic microscopy (SEM) of the joints of CAE infected and normal goats. Humerus head surface of positive animals presented reduced joint space, increased bone density, and signs of degenerative joint disease (DJD). The carpal joint presented no morphological alterations in CR in any of the animals studied. Tarsus joint was the most affected, characterized by severe DJD, absence of joint space, increased periarticular soft tissue density, edema, and bone sclerosis. Histological analysis showed chronic tissue lesions, complete loss of the surface zone, absence of proteoglycans in the transition and radial zones and destruction of the cartilage surface in the CAE positive animals. Analysis by SEM showed ulcerated lesions with irregular and folded patterns on the joint surface that distinguished the limits between areas of normal and affected cartilage. The morphological study of the joints of normal and CAE positive goats deepened understanding of the alteration in the tissue bioarchitecture of the most affected joints. The SEM finding sustained previous histological reports, similar to those found for rheumatoid arthritis, suggesting that the goat infected with CAE can be considered as a potential model for research in this area.

Bovine Teeth in Age Assessment, from Medieval Cattle to Belgian Blue : Methodology, Possibilities and Limitations

The overall aim of the present thesis was to develop and characterise an age assessment method based on incremental lines in dental cementum using contemporary bovine teeth and teeth from archaeological faunal assemblages. The investigations also included two other age assessment methods: tooth wear pattern and macroscopic dental measurements. The first permanent mandibular molar and lower jaws from 70 contemporary cattle of known age and 170 archaeological molar sets from ten different Swedish archaeological sites were used. The following conclusions were drawn: • The number of incremental lines in the dental cementum varied between different parts of the tooth root as well as within one and the same individual. The results from contemporary cattle of known age showed a strong relationship between age and incremental lines in the cementum of the distal part of the mesial root (R2=65.5%) and the known ages of the animals. • With the “best” model variation in age could be explained to 65.5% (R2) by the number of incremental lines. Thus, the remaining age variation (approximately 35%) could not be explained by these lines. Other factors than must thus be responsible. However, with the exception of calves born the present material did not reveal any such significant relationship. • The results from cattle of known age indicate that the method of assessing age on the basis of cemental incremental lines is more reliable than other methods such as tooth wear or tooth measurements. However, by combining counting incremental lines and one variable assessing tooth dimension (tooth height) a slightly stronger relationship could be obtained (R2=74.5%). The results from age assessment of the medieval and post-Reformation cattle emphasize the importance of supplementing any age estimation of archaeological assemblages based on dental indicators with characteristics for the particular assessment model. Furthermore, conclusions based on age assessment with such models can not be drawn with any more detailed time scale than about 2 years leaving at best only 25% (R2) of factors influencing the dental indicator(s) utilized in the model unexplained. The accuracy of the age assessment required by the particular historical context in which the archaeological remains are found should thus decide what level of accuracy should be chosen.

Effect of different live prey, Grapsus grapsus Linnaeus 1758 and Plagusia depressa Fabricius, 1775 zoeas,over histology and biochemical composition of common octopus, octopus vulgaris Cuvier, 1797 paralarvae

[EN] Since paralarval rearing is still the main bottleneck for the development of octopus culture, the aim of the present study was to obtain some information on the feeding strategy and nutritional requirements during paralarval stage. For that purpose just hatched out octopus paralarvae were fed with live preys in three different combinations, trying to match their natural food: Enriched Artemia metanauplii, Grapsus grapsus zoeas supplemented with enriched Artemia, and Plagusia depressa zoeas supplemented with enriched Artemia. Paralarval treatments were carried out during 28 days in triplicates; fibre glass 120 l tanks in flow through system were used. Growth, in terms of dry body weight, mantle length and width, was determined each seven days. A histological study of the paralarval development was carried out. Biochemical composition of preys and paralarvae were determined. Growth was significantly better in paralarvae fed with zoeas and Artemia than in those fed only with Artemia, from day 8 after hatching. Besides a clear effect on the digestive gland histology morphology was observed.

The effects of supplementation of decapod zoea to Artemia basal diet on the digestive gland histology and the fatty acid composition in common octopus (Octopus vulgaris) paralarvae.

[EN]The present study aimed to evaluate the effect of the supplementation of different crab zoeas to enriched Artemia basal diet for O. vulgaris paralarvae during the first month of life. Paralarvae were fed using: enriched Artemia nauplii alone and Artemia co-fed with either first zoea stages of Grapsus adscensionis or Plagusia depressa. The experiment was carried out over a period of 28 days, in 0.12 m3 tanks with a flow-through rearing system. Growth in dry weightas well as mantle length and width were assessed weekly. Additionally, prey and paralarvae fatty acid composition and digestive gland (DG) histology were evaluated.

Identification of CNV and QTL for productive and functional traits in dairy cattle using dense SNP chips

The thesis identify CNV structural variants as possible markers for genomic selection and identify QTL regions for Fatty Acid Content in the Italian Brown Swiss population. Additionally it maps the QTL for mastitis resistance in the Valdostana Red Pied cattle.

A new histology scoring system for the assessment of the quality of human cartilage repair: ICRS II

A reliable and reproducible method is needed to assess cartilage repair.

Plaque characteristics of nonobstructive coronary lesions in diabetic patients: an intravascular ultrasound virtual histology analysis

Patients with diabetes mellitus are known to be at increased risk for acute cardiovascular events. We used intravascular ultrasound virtual histology (IVUS-VH) to examine whether nonobstructive coronary artery lesions of diabetic patients have distinct plaque composition and morphology compared with nondiabetic patients.

Analysis of coronary bifurcations by intravascular ultrasound and virtual histology

Background Regional differences in shear stress have been identified as reason for early plaque formation in vessel bifurcations. We aimed to investigate regional plaque morphology and composition using intravascular ultrasound (IVUS) and virtual histology (IVUS–VH) in coronary artery bifurcations. Methods We performed IVUS and IVUS–VH studies at coronary bifurcations to analyze segmental plaque burden and composition of different segments in relation to their orientation to the bifurcation. Results A total of 236 patients with a mean age of 59 ± 11 years (69% male) were analyzed. Plaque burden was higher at the contralateral vessel wall facing the bifurcation compared to the ipsilateral vessel wall and this difference was true for proximal and distal segments (proximal: 37 ± 12% and 45 ± 15% for segments at the ipsilateral and contralateral vessel wall, respectively, p < 0.001; distal: 37 ± 10% and 47 ± 15% for segments at the ipsilateral and contralateral vessel wall, respectively, p < 0.001). In addition, these segments exhibited a higher proportion of dense calcium and a lower proportion of fibrous tissue and fibro fatty tissue. Conclusions Segments on the contralateral wall of the bifurcation which have previously been identified as regions with low shear stress not only exhibited a higher plaque burden, but also a higher degree of calcification.

Analysis of 1 year virtual histology changes in coronary plaque located behind the struts of the everolimus eluting bioresorbable vascular scaffold

Serial intravascular ultrasound virtual histology (IVUS-VH) after implantation of metallic stents has been unable to show any changes in the composition of the scaffolded plaque overtime. The everolimus-eluting ABSORB scaffold potentially allows for the formation of new fibrotic tissue on the scaffolded coronary plaque during bioresorption. We examined the 12 month IVUS-VH changes in composition of the plaque behind the struts (PBS) following the implantation of the ABSORB scaffold. Using IVUS-VH and dedicated software, the composition of the PBS was analyzed in all patients from the ABSORB Cohort B2 trial, who were imaged with a commercially available IVUS-VH console (s5i system, Volcano Corporation, Rancho Cordova, CA, USA), immediately post-ABSORB implantation and at 12 month follow-up. Paired IVUS-VH data, recorded with s5i system, were available in 17 patients (18 lesions). The analysis demonstrated an increase in mean PBS area (2.39 ± 1.85 mm(2) vs. 2.76 ± 1.79 mm(2), P = 0.078) and a reduction in the mean lumen area (6.37 ± 0.90 mm(2) vs. 5.98 ± 0.97 mm(2), P = 0.006). Conversely, a significant decrease of 16 and 30% in necrotic core (NC) and dense calcium (DC) content, respectively, were evident (median % NC from 43.24 to 36.06%, P = 0.016; median % DC from 20.28 to 11.36%, P = 0.002). Serial IVUS-VH analyses of plaque located behind the ABSORB struts at 12-month demonstrated an increase in plaque area with a decrease in its NC and DC content. Larger studies are required to investigate the clinical impact of these findings.

Comparison between the first and second generation bioresorbable vascular scaffolds: a six month virtual histology study

To compare the intravascular ultrasound virtual histology (IVUS-VH) appearance of the polymeric struts of the first (Revision 1.0) and the second (Revision 1.1) generation bioresorbable vascular scaffold (BVS).

Histology of damaged acetabular cartilage in symptomatic femoroacetabular impingement: an observational analysis

This prospective study on symptomatic adult patients with femoroacetabular impingement (FAI) who underwent open surgical intervention for management was designed to identify any obvious histological differences in the damaged acetabular cartilage within different subgroups of FAI. 20 patients underwent surgical intervention following safe surgical dislocation of the hip. There were 6 cases of cam impingement, 5 cases of pincer impingement and 9 of the mixed type. Pincer impingement cases demonstrated a characteristic focal, well-circumscribed and localized area of severe damage. On the other hand, cases with cam impingement showed a diffuse area of involvement affecting a larger surface of the acetabular cartilage, with degenerative changes, superficial erosions and some discontinuities. A small biopsy specimen of the acetabular rim including bone, cartilage and labrum from the affected zone was obtained in all cases. Histological evaluation was performed under normal and polarized light microscopy. Histological findings helped corroborate the pre-operative diagnosis and also define the unique nature of impingement and specific damage according to the type of impingement.