Experimental poisoning by Senecio brasiliensis in calves: quantitative and semi-quantitative study on changes in the hepatic extracellular matrix and sinusoidal cells

A matriz extracelular (MEC) desempenha um papel importante em lesões hepáticas crônicas e tem sido estudada em modelos de intoxicação experimental. em bovinos, no entanto, não há estudos específicos sobre a MEC hepática normal ou com lesões crônicas. Por isso, foi desenvolvido um modelo de intoxicação experimental hepático usando Senecio brasilliensis, uma planta que contém alcalóides pirrolizidínicos e causa lesão hepática dependente da dose. Cinco bezerros receberam por via oral, 0.38g/kg de folhas secas por 24 dias. Biópsias hepáticas foram obtidas a cada 15 dias durante 60 dias. Sinais clínicos de complicações digestivas surgiram da terceira semana do experimento. Um bezerro morreu aos 45 dias e os outros quatro foram avaliados até os 60 dias. As biópsias hepáticas foram processadas para microscopia óptica, imuno-histoquímica e microscopia eletrônica de transmissão. No trigésimo dia, as lesões hepáticas eram progessivas caracterizadas por vacuolização hepatocelular, necrose, apoptose, megalocitose, e fibrose centrolobular, pericelular e portal. Foram realizadas avaliações quantitativas e semi-quantitativas de componentes da MEC hepática antes e após o aparecimento das lesões. Foi realizada morfometria do colágeno total e do sistema de fibras elásticas. Colágeno total e colágenos tipos I e III aumentaram progressivamente em todos os locais do fígado. Mudanças na localização, quantidade e disposição do sistema de fibras elásticas foram também observadas. Houve um aumento significativo de células de Kupffer aos 30 dias e de células sinusoidais totais aos 45 e 60 dias. As lesões hepáticas neste experimento foram progressivas mesmo após a remoção da planta. Lesões de fibrose severa foram localizadas principalmente nos espaços porta, seguido por fibrose veno-oclusiva e pericelular. Os colágenos tipo I e tipo III foram observados no fígado normal e no fígado dos bezerros afetados, com predomínio do tipo I. Nos bezerros afetados o aumento do colágeno total e do sistema de fibras elásticas foi paralelo ao aumento no número das células sinusoidais.

Prospective Evaluation of Dietary Treatment in Childhood Constipation: High Dietary Fiber and Wheat Bran Intake Are Associated With Constipation Amelioration

Objectives: The aim of the study was to evaluate, over 24 months, the intake of dietary fiber (DF) and the bowel habit (BH) of constipated children advised a DF-rich diet containing wheat bran.Patients and Methods: BH and dietary data of 28 children with functional constipation defined by the Boston criteria were obtained at visit 1 (V1, n = 28) and at 4 follow-up visits (V2-V5, n = 80). At each visit the BH was rated BAD (worse/unaltered; improved but still complications) or RECOVERY (REC) (improved, no complications; asymptomatic), and a food intake questionnaire was applied. DF intake was calculated according to age (year)+5 to 10 g/day and bran intake according to international tables. Nonparametric statistics were used.Results: Median age (range) was 7.25 years (0.25-15.6 years); 21 children underwent bowel washout (most before V1/V2), and 14 had the last visit at V3/V4. DF intake, bran intake, and the BH rate significantly increased at V2 and remained higher than at V1 through V2 to V5. At V1, median DF intake was 29.9% below the minimum recommended and at the last visit 49.9% above it. Twenty-four children accepted bran at 60 visits, at which median bran intake was 20 g/day and median proportion of DF due to bran 26.9%. Children had significantly higher DF and higher bran intake at V2 to V5 at which they had REC than at those at which they presented BAD BH. DF intake > age+10 g/day was associated with bran acceptance and REC. At the last visit 21 children presented REC (75%); 20 of them were asymptomatic and 18 were off washout/laxatives.Conclusions: High DF and bran intake are feasible in constipated children and contribute to amelioration of constipation.

Injectable gels of anionic collagen : rhamsan composites for plastic correction: Preparation, characterization, and rheological properties

The present article describes the preparation and characterization A anionic Collagen gels obtained from porcine intestinal submucosa after 72 h of alkaline treatment and in the form of rhamsan composites to develop injectable biomaterials for plastic for construction. All materials were characterized by SDS/polyacrylamide gel electrophoresis, infrared spectroscopy, thermal stability, potentiometric titration, rheological properties, and fluidity tests. Biocompatibility was appraised after the injection of anionic collagen:rhamsan composites at 2.5% in 60 North Folk rabbits. Independently of processing, the Collagen's secondary structure was preserved in all cases, and after 72 h of hydrolysis the Collagen was characterized by a carboxyl group content of 346 :L 9, which, at physiological pH, corresponds to an increase of 106 17 negative charges, in comparison to native Collagen, due to the selective hydrolysis of asparagine and glutamine carboxyamide side chain. Rheological studies of composites at pH 7.4 in concentrations of 2, 4, and 6% (in proportions of 75:1 and 50:1) showed a viscoelastic behavior dependent on the frequency, which is independent of concentration and proportion. In both, the concentration of the storage modulus always predominated over the loss modulus (G' > G and delta < 45 degrees). The results from creep experiments confirmed this behavior and showed that anionic collagen:rhamsan composites at pH 7.4 in the proportion of 50:1 are less elastic and more susceptible to deformation in comparison to gels in the proportion of 75:1, independent of concentration. This was further confirmed by flow experiments, indicating that the necessary force for the extrusion of anionic collagen:rhamsan composites, in comparison to anionic Collagen, was significantly smaller and with a smooth flow. Biocompatibility studies showed that the tissue reaction of anionic collagen:rhamsan composites at 2.5% in the proportion of 75:1 was compatible with the application of these gels in plastic reconstruction. These results suggest that the association of Collagen with rhamsan may be a good alternative in the replacement of glutaraidehyde to stabilize the microfibril assembly of commercial Collagen gel preparations. (c) 2005 Wiley Periodicals, Inc.

Collagen dysplasia (cutaneous asthenia) in a cat

Hereditary collagen dysplasias comprise a complex group of connective-tissue disorders that result in the reduced tensile strength of affected tissues. These processes are called cutaneous asthenia in the skin of dogs and cats. We report here the case of a crossbred male cat, aged 6 months, that presented with two skin wounds in the region of the right thorax and right iliac tuberosity. The skin of these regions and of the animal's dorsum was hyperextensible, smooth to the touch, and easily torn with minor trauma. Microscopic examination of skin samples revealed reduced dermal connective tissue consisting of shortened and fragmented collagen fibers. Normal fibers were intermingled with altered fibers. Ultrastructural changes in collagen fibers included disorientation of fibrils within the same bundle, marked spacing differences, and variation in the diameter of transverse sections. The fibrils maintained the transverse striations characteristic of normal collagen.

Influence of feeding regime and finishing system on lamb muscle fiber and meat quality

Avaliou-se a influência dos níveis nutricionais da ovelha antes do parto, da idade à desmama e do sistema de terminação sobre as fibras musculares e a qualidade da carne dos cordeiros. Utilizaram-se matrizes mestiças Ile de France × Bergamacia criadas a pasto. As ovelhas foram divididas em dois grupos: um com suplementação alimentar 30 dias antes do parto e outro sem suplementação. Os animais (ovelha e cordeiros) foram subdivididos de acordo com a idade à desmama (45 ou 60 dias de idade) e os cordeiros desmamados foram submetidos a três sistemas de terminação: confinamento com dieta completa; confinamento somente com feno; e confinamento somente no pasto. O abate dos cordeiros foi realizado aos 30 kg de peso vivo ou aos 150 dias de idade. As características de carcaça analisadas foram morfofisiologia da fibra do músculo longissimus dorsi, fragmentação miofibrilar pós-morte (maturados nos dias 0, 3 e 7 pos mortem) e redução do pH e da temperatura da carne pós-abate. Não houve efeito da suplementação às ovelhas ou da idade à desmama sobre nenhuma das características avaliadas. A composição em fibras de contração lenta e oxidativa, contração rápida e oxidativa ou contração rápida e glicolítica não foi alterada pelos fatores em estudo, mas a área transversal das fibras foi menor nos cordeiros terminados com feno, assim como os valores de pH, temperatura e as medidas dos fragmentos de miofibrila. Com o aumento do tempo de maturação de 0 para 3 e 7 dias post mortem, houve redução do comprimento dos fragmentos de miofibrilas. O sistema de terminação de cordeiros em confinamento somente com feno interfere mais intensamente na qualidade da carne que o sistema de terminação a pasto ou em confinamento com dieta completa.

Age-related changes in muscle fiber type frequencies and cross-sectional areas in straightbred and crossbred rabbits

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Muscle fiber type characterization and myosin heavy chain (MyHC) isoform expression in Mediterranean buffaloes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro cultivation of canine multipotent mesenchymal stromal cells on collagen membranes treated with hyaluronic acid for cell therapy and tissue regeneration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of Adipose Tissue-Derived Mesenchymal Stem Cells for Experimental Tendinitis Therapy in Equines

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Clinical evaluation and induced corneal vascularization study by native and anionic collagen membranes in rabbits corneas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Clinical and histological evaluation of subepithelial connective tissue after collagen sponge implantation in the human palate

Rocha AL, Shirasu BK, Hayacibara RM, Magro-Filho O, Zanoni JN, Araujo MG. Clinical and histological evaluation of subepithelial connective tissue after collagen sponge implantation in the human palate. J Periodont Res 2012; 47: 758765. (c) 2012 John Wiley & Sons A/S Background and Objective: Successful root-coverage treatment depends on the thickness of the donor tissue. This study aimed to evaluate the thickness of donor tissue after augmentation of the connective tissue in the palatal area by implantation of lyophilized collagen sponge (Hemospon (R)). Material and Methods: Ten patients with an indication for root coverage, whose palate was deficient in adequate connective tissue, were recruited. The procedure was carried out in two stages. In the first stage, the palatal thickness in the donor site was measured at three standardized points (points 1, 2 and 3), from the distal of the canine to the distal of the first molar, and the lyophilized collagen sponge was inserted. In the second stage, the palatal thickness over the implant was measured (at points 1, 2 and 3), two biopsies of the palatal mucosa were collected one over the implant (experimental sample) and the other on the contralateral side (control sample) and then root-coverage treatment was performed. Analyses consisted of clinical assessment of the palatal measurements before and after sponge implantation, and histological assessment of the experimental and control biopsy samples. Data were analyzed using the Wilcoxon test. Results: Both analyses showed a significant increase in mean thickness, of 1.08 mm of neoformed tissue in the clinical analysis (the tissue at point 2 was the thickest of the three points) and of 0.53 mm in the histological analysis. Conclusion: The insertion of lyophilized collagen sponge induced a significant increase in the thickness of palatal connective tissue.

Exposed collagen in aged resin-dentin bonds produced on sound and caries-affected dentin in the presence of chlorhexidine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The controlled release of antibiotic by hydroxyapatite: Anionic collagen composites

Major problems with the treatment of osteomyelitis are associated with poor antibiotic distribution at the site of infection due to limited blood circulation to the skeletal tissue. Improved treatment procedures have been used in drug delivery systems that include bioceramics and natural and synthetic polymers. This work reports the development of anionic collagen:hydroxyapatite composite paste for sustained antibiotic release. Antibiotic release by the composite was characterized by two steps. In the first, 15.0 +/- 4.9% was released in the first 5 h (n = 53) by a normal Fick diffusion mechanism. In the second step, only 16.8 +/- 2.2% was released after 7 days. In conclusion, hydroxyapatite:anionic collagen composite can be an efficient support for sustained antibiotic release in the treatment of osteomyelitis because most of the antibiotic release may be associated with composite bioresorption, thus permitting antibiotic release throughout the healing process. Hydroxyapatite:anionic collagen paste showed good biocompatibility associated with bone tissue growth with material still being observed after 60 days from the time of implants.

Tissue response to polyanionic collagen: elastin matrices implanted in rat calvaria

The tissue response to polyanionic collagen matrices, prepared from bovine pericardium and implanted subperiosteally in rat calvaria, was studied. The materials were implanted in 72 male rats (Rattus norvegicus, albinus, Holtzman), randomly divided into four groups: GI-MBP hydrolyzed for 24 h; GII-MBP hydrolyzed for 36 h; GIII-MBP hydrolyzed for 48 h; GIV-native M BP. The materials were explanted after 15, 30 and 60 days and analyzed by routine histological procedures. Except for group IV (native bovine pericardium), polyanionic collagen from groups GI, GII and GIII showed low inflammatory reaction associated with bone formation, partially or completely integrated to the cranial bone; group GIV was characterized by an intense inflammatory reaction with occasional dystrophic mineralization and with occasional bone formation at 60 days when there was a decrease in the inflammatory reaction. Thus, the MBP from groups I, II and III were biologically compatible, enhancing bone formation with a slight delay at 60 days in GII. (C) 2002 Elsevier B.V. Ltd. All rights reserved.