Acellular dermal tissue study: an ultrastructural evaluation of human and porcine derived tissues in a rat model

The purpose of this study was to evaluate the host response of a human and a porcine derived acellular dermal tissue (ADT) implanted in the subcutaneous tissue of a rat model. Two subcutaneous pockets were surgically created along the dorsal midline of 25 rats (5 rats/group). The human ADT was placed superiorly and the porcine ADT, inferiorly. The animals were sacrificed at 07, 15, 30, 60 and 180 postoperative days (PO) and the ADTs and surrounding soft tissues were assessed for ultrastructural evaluation by transmission electron microscopy. The ultrastructural findings were similar in both materials. Normal collagen and elastic fibers bundles were observed during all experimental moments, as well as macrophages presenting cytoplasmic enlargements digesting cellular portions after 15 PO. From 30 until 180 PO, vacuolar structures filled with an amorphous, electron-transparent substance, were present inside and outside the fibroblasts. Both human and porcine ADT showed similar pattern of ultrastructural response when implanted in the subcutaneous tissue of rats. The porcine ADT appears as a good alternative to be used as a biomaterial.

A comparison of human and porcine acellular dermal tissues in the subcutaneous space of a rat model

The study compared the host response to a human and a porcine acellular dermal tissue implanted in the subcutaneous space of a rat model. The human and porcine acellular grafts were surgically implanted in the subcutaneous tissue of rats (5 rats/group) and the materials were evaluated at 7, 15, 30, 60 and 180 postoperative days (PO). The histological immune response was quantified using a digital image analysis system, which evaluated the number of vessels present in the implants and in the surrounding soft tissue, the area of inflammatory cell infiltration in the grafts, the width of the capsular formation present around the tissues and the area of implants absorbed. The data were submitted to statistical analysis. Light microscopy showed mononuclear cellular infiltration, the presence of a capsular formation surrounding the grafts and the presence of vacuolar structures (optically empty spaces) inside the implants. The image analysis comparing both materials showed significant inflammatory cells in the human graft at 15 and 30 PO, thicker capsular formation in the porcine tissue at 60 PO, increased number of vessels inside the implants and in the surrounding tissues in the porcine graft and a similar absorption pattern in both materials at 180 PO. The histological findings showed that both tissues were well-tolerated when implanted in the subcutaneous tissue of rats, allowing us to consider the porcine acellular dermal graft as a provisional alternative material for reconstructive plastic surgery. Copyright © 2005 Taylor & Francis LLC.

Ovarian response to porcine FSH in association with ablation-induced or spontaneous follicular wave development during the estrous cycle in crossbred and Brazilian Warmblood mares

The primary objective of this study was to examine the follicular and ovulatory responses following treatment with pFSH in association with ablation-induced or spontaneous follicular wave emergence or follicle deviation during diestrus in crossbred (Mangalarga × Arabian) and Brazilian Warmblood mares with a propensity for spontaneous multiple ovulations; secondary considerations were given to the collection of embryos In Experiment 1, crossbred mares were administered (im) saline (control, n= 7) or pFSH (25 mg) when the largest follicle of the ablation-induced follicular wave reached ≥13 mm (n= 7) or ≥20 mm (n= 7) or, after pre-treatment ovulation (Day 0) on Day 6 (n= 7) In Experiment 2, crossbred mares were administered (im) saline (control, n= 10) or a larger dose of pFSH (50 mg, n= 7) when the largest follicle of the ablation-induced follicular wave reached ≥13 mm In Experiment 3, Brazilian Warmblood mares were administered (im) saline (control, n= 7), pFSH (25 mg, n= 7 or 50 mg, n= 5) or EPE (12.5 mg, n= 7) as a positive control on Day 6 Ultrasonic technology was used to ablate all follicles ≥8 mm and to monitor follicular development and detect ovulation Treatment with pFSH or EPE was done twice daily until the largest follicle reached ≥32 mm; thereafter, hCG (2500 IU) was administered (iv) when the largest follicle reached ≥35 mm Artificial insemination was done 12 h after hCG and embryo collections were done 8 d after post-treatment ovulations In Experiments 1 and 2, treatment of crossbred mares with pFSH post-ablation in association with the expected time of wave emergence or follicle deviation did not (P> 0.05) enhance the follicular or ovulatory responses or collection of embryos compared to controls In Experiment 3, although the enhanced ovulatory response of mares to EPE at the expected time of spontaneous wave emergence was not different (P> 0.05) from controls, it was greater (P< 0.05) than the response to pFSH In conclusion, the novelty of using follicle ablation prior to pFSH treatment at the time of wave emergence or follicle deviation did not enhance the follicular or ovulatory responses or collection of embryos to treatment in crossbred mares In addition, the hypothesis that Brazilian Warmblood mares with a greater propensity for spontaneous multiple ovulations are as responsive to pFSH compared to EPE was not supported Thus, the combined experimental results of the present study continue to support the general consensus that pFSH is relatively ineffective for follicular superstimulation/superovulation in mares © 2012 Elsevier B.V.

Grafts of porcine small intestinal submucosa seeded with cultured homologous smooth muscle cells for bladder repair in dogs

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

Validation of cone-beam computed tomography and magnetic resonance imaging of the porcine spine: a comparative study with multidetector computed tomography and anatomical specimens

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

Bat coronavirus in brazil related to appalachian ridge and porcine epidemic diarrhea viruses

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

Induction of short gut syndrome and transplantation in a porcine model

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

Assessment of ALA-induced PpIX production in porcine skin pretreated with microneedles

Photodynamic therapy (PDT) is used for skin treatments of premalignant and cancer lesions and recognized as a non-invasive technique that combines tissue photosensitization and subsequent exposure to light to induce cell death. However, it is limited to the treatment of superficial lesions, mainly due to the low cream penetration. Therefore, the improvement of transdermal distribution of aminolevulinic acid (ALA) is needed. In this study, the kinetics and homogeneity of production of ALA-induced PpIX after the skin pre-treatment with microneedles rollers of 0.5, 1.0 and 1.5 mm length were investigated. An improvement in homogeneity and production of PpIX was shown in a porcine model. Widefield fluorescence imaging three hours after the topical application of ALA-cream in the combined treatment with microeedles rollers.

THE GLYCOPROTEINS OF PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS AND THEIR ROLE IN INFECTION AND IMMUNITY

The porcine reproductive and respiratory syndrome virus (PRRSV) is an economically important pathogen of swine and is known to cause abortion and infertility in pregnant sows and respiratory distress in piglets. PRRSV contains a major glycoprotein (GP5) and three minor glycoproteins (GP2a, GP3, and GP4) on the virion envelope, all of which are required for infectious virus production. To study their interactions amongst each other and with a cellular receptor for PRRSV, CD163, I cloned each of the viral glycoproteins and CD163 in various expression vectors. My studies have shown that while the GP2a, GP3, and GP4 are co-translationally glycosylated, the GP5 is post-translationally glycosylated. By using co-immunoprecipitation (co-IP) assays, strong interaction was demonstrated between GP4 and GP5 proteins, although weak interactions among the other envelope glycoproteins were also detected. Further, GP4 was found to mediate interactions leading to formation of multiprotein glycoprotein complex. My results also show that GP2a and GP4 proteins are the only two GPs that specifically interact with the CD163 molecule and that glycosylation of these GPs is required for efficient interaction. Based on these studies, I have developed an interactome map of the viral GPs and CD163 and have proposed a model of the viral glycoprotein complex and its interaction with CD163. Studies reported here also show that glycan addition at residue 184 (N184) of GP2a, and residues N42, N50, and N131 of GP3 is essential for recovery of infectious virus. Although single site glycosylation mutants of GP4 had no effect on infectious virus production, introduction of double mutations was lethal. The loss of glycan moieties of GP2a, GP3, and GP4 proteins had no effect on host neutralizing antibody production. Overall, I conclude that the PRRSV glycoproteins are co-translationally and post-translationally glycosylated, the GP4 protein is central to mediating interglycoprotein interactions, and along with GP2a, serves as the viral attachment protein that is responsible for interactions with the viral receptor, CD163. Further, glycosylation of GP2a, GP3, and GP4 proteins is required for infectious virus production, efficient interaction with CD163, but does not play any role in neutralizing antibody response in infected animals.

Purification and characterization of aprotinin from porcine lungs

Aprotinin, the most studied serine proteinase inhibitor, was isolated from porcine lung for the first time. The purified porcine aprotinin had an Mr value of similar to 7 kDa. It cross- reacted with polyclonal serum anti- commercial aprotinin. About 1 mu g porcine aprotinin inhibited 6 mu g trypsin whereas 1 mu g commercial soybean inhibitor inhibited only 1 mu g trypsin. The aprotinin gene was also isolated from porcine lung: the deduced amino acid sequence showed 74% identity to bovine aprotinin.

Surgical Performance During Laparoscopic Radical Nephrectomy Is Improved With Training in a Porcine Model

Background and Purpose: Becoming proficient in laparoscopic surgery is dependent on the acquisition of specialized skills that can only be obtained from specific training. This training could be achieved in various ways using inanimate models, animal models, or live patient surgery-each with its own pros and cons. Currently, there are substantial data that support the benefits of animal model training in the initial learning of laparoscopy. Nevertheless, whether these benefits extent themselves to moderately experienced surgeons is uncertain. The purpose of this study was to determine if training using a porcine model results in a quantifiable gain in laparoscopic skills for moderately experienced laparoscopic surgeons. Materials and Methods: Six urologists with some laparoscopic experience were asked to perform a radical nephrectomy weekly for 10 weeks in a porcine model. The procedures were recorded, and surgical performance was assessed by two experienced laparoscopic surgeons using a previously published surgical performance assessment tool. The obtained data were then submitted to statistical analysis. Results: With training, blood loss was reduced approximately 45% when comparing the averages of the first and last surgical procedures (P = 0.006). Depth perception showed an improvement close to 35% (P = 0.041), and dexterity showed an improvement close to 25% (P = 0.011). Total operative time showed trends of improvement, although it was not significant (P = 0.158). Autonomy, efficiency, and tissue handling were the only aspects that did not show any noteworthy change (P = 0.202, P = 0.677, and P = 0.456, respectively). Conclusions: These findings suggest that there are quantifiable gains in laparoscopic skills obtained from training in an animal model. Our results suggest that these benefits also extend to more advanced stages of the learning curve, but it is unclear how far along the learning curve training with animal models provides a clear benefit for the performance of laparoscopic procedures. Future studies are necessary to confirm these findings and better understand the impact of this learning tool on surgical practice.

Detection of porcine circovirus genotypes 2a and 2b in aborted foetuses from infected swine herds in the State of Sao Paulo, Brazil

Background: Porcine circovirus type 2 (PCV2) has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of Sao Paulo, Brazil and to investigate co-infections with other infectious organisms. Findings: Samples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of Sao Paulo were tested for PCV2 by polymerase chain reaction (PCR). Positive samples were additionally tested for porcine parvovirus (PPV), Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%). PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1) or 2b (n = 10). Conclusions: The findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of Sao Paulo is rather low (10.7%) and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.

DETECTION OF GENETIC CHARACTERIZATION OF PORCINE CIRCOVIRUS 2 (PCV2) IN BRAZILIAN WILDLIFE BOARS

A semi-intensive wildlife boars farm presented a clinical history of high mortality in 70 - 90 days-old pigs (> 50 %). Two 90 days-old animals with weight loss and wasting were necropsied and the samples tested for PCV2 by polymerase chain reaction (PCR). The genetic material of PCV2 was sequenced and classified into the PCV2a genotype together with PCV2 sequences obtained from samples of Poland, Brazil, Slovenia and Greece wild boars.

Effect of treatment delay on disease severity and need for resuscitation in porcine fecal peritonitis

Objective: Early treatment in sepsis may improve outcome. The aim of this study was to evaluate how the delay in starting resuscitation influences the severity of sepsis and the treatment needed to achieve hemodynamic stability. Design: Prospective, randomized, controlled experimental study. Setting: Experimental laboratory in a university hospital. Subjects: Thirty-two anesthetized and mechanically ventilated pigs. Interventions: Pigs were randomly assigned (n = 8 per group) to a nonseptic control group or one of three groups in which fecal peritonitis (peritoneal instillation of 2 g/kg autologous feces) was induced, and a 48-hr period of protocolized resuscitation started 6 (Delta T-6 hrs), 12 (Delta T-12 hrs), or 24 (Delta T-24 hrs) hrs later. The aim of this study was to evaluate the impact of delays in resuscitation on disease severity, need for resuscitation, and the development of sepsis-associated organ and mitochondrial dysfunction. Measurements and Main Results: Any delay in starting resuscitation was associated with progressive signs of hypovolemia and increased plasma levels of interleukin-6 and tumor necrosis factor-alpha prior to resuscitation. Delaying resuscitation increased cumulative net fluid balances (2.1 +/- 0.5 mL/kg/hr, 2.8 +/- 0.7 mL/kg/hr, and 3.2 +/- 1.5 mL/kg/hr, respectively, for groups.T-6 hrs, Delta T-12 hrs, and.T-24 hrs; p < .01) and norepinephrine requirements during the 48-hr resuscitation protocol (0.02 +/- 0.04 mu g/kg/min, 0.06 +/- 0.09 mu g/kg/min, and 0.13 +/- 0.15 mu g/kg/min; p = .059), decreased maximal brain mitochondrial complex II respiration (p = .048), and tended to increase mortality (p = .08). Muscle tissue adenosine triphosphate decreased in all groups (p < .01), with lowest values at the end in groups Delta T-12 hrs and.T-24 hrs. Conclusions: Increasing the delay between sepsis initiation and resuscitation increases disease severity, need for resuscitation, and sepsis-associated brain mitochondrial dysfunction. Our results support the concept of a critical window of opportunity in sepsis resuscitation. (Crit Care Med 2012; 40:2841-2849)

Preliminary study of Porcine circovirus type 2 and Torque teno sus virus coinfection frequencies in Brazilian pig herds

Torque teno sus virus (TTSuV) is emergent in swine herds. Recent studies have shown an increased frequency of TTSuV2 in Porcine circovirus type 2 (PCV2)-associated diseases (PCVAD), which are endemic in many swine-producing countries, including Brazil. Coinfection with several other viral and bacterial agents results in an increased incidence of more severe PCVAD. Given the limited information on TTSuV and PCV2 coinfection, especially in Brazilian swine herds, this study made a preliminary estimation of the occurrence of coinfection in swine herds by testing samples from different categories. Between 2008 and 2009, 111 samples of feces and 23 serum samples from 5 swine herds were tested for PCV2 and TTSuVs and the results analyzed for associations between these agents. No significant differences in coinfection frequency were observed for PCV2 1 + TTSuV1 or for PCV2 1 TTSuV2 between nursery piglets (P = 0.730), growing pigs (P = 0.331), or sows (P = 0.472). However, a significant difference was observed for PCV2 1 TTSuV1 1 TTSuV2 between nursery piglets and growing pigs (P = 0.004; Fisher's exact test). Phylogenetic studies agreed with the grouping of TTSuV1 and TTSuV2 into 2 different clades, with no distinct pattern of clustering of these isolates with the animal categories.