Adult Female Pigs Research Articles

Identification and characterization of putative stem cells in the adult pig ovary.

Recently, the concept of 'neo-oogenesis' has received increasing attention, since it was shown that adult mammals have a renewable source of eggs. The purpose of this study was to elucidate the origin of these eggs and to confirm whether neo-oogenesis continues throughout life in the ovaries of the adult mammal. Adult female pigs were utilized to isolate, identify and characterize, including their proliferation and differentiation capabilities, putative stem cells (PSCs) from the ovary. PSCs were found to comprise a heterogeneous population based on c-kit expression and cell size, and also express stem and germ cell markers. Analysis of PSC molecular progression during establishment showed that these cells undergo cytoplasmic-to-nuclear translocation of Oct4 in a manner reminiscent of gonadal primordial germ cells (PGCs). Hence, cells with the characteristics of early PGCs are present or are generated in the adult pig ovary. Furthermore, the in vitro establishment of porcine PSCs required the presence of ovarian cell-derived extracellular regulatory factors, which are also likely to direct stem cell niche interactions in vivo. In conclusion, the present work supports a crucial role for c-kit and kit ligand/stem cell factor in stimulating the growth, proliferation and nuclear reprogramming of porcine PSCs, and further suggests that porcine PSCs might be the culture equivalent of early PGCs.

Greater Surgical Precision of a Flexible Carbon Dioxide Laser Fiber Compared to Monopolar Electrosurgery in Porcine Myometrium

The objective of this experimental animal study was to compare the surgical precision of a flexible CO2 laser fiber with that of monopolar electrosurgery in porcine myometrium. The subjects were 6 live adult non-pregnant female pigs. Linear injury to the uterine horns was created using a flexible CO2 laser fiber at 5W, 10W, and 15W and with monopolar electrosurgery at 10W, 20W, 30W, and 40W in both cut and coagulation modes. Hysterectomy was then performed in the live animals. Cross-sections of the tissue were processed and stained using Masson trichrome to differentiate damaged from undamaged myometrium. Measurement means were compared using analysis of variance with Tukey honest significant difference correction; p <.05 indicated significance. Incision width of the laser at 5W and 10W was significantly less than both monopolar coagulation at all power settings and monopolar cut at 30W and 40W (all p <.01), at 5W was also significantly less than monopolar cut at 10W (p = .03), and at 15W was significantly less than monopolar coagulation at 40W (p = .001). Incision depth of the laser at 5W was significantly less than monopolar coagulation at 40W and laser at 15W (both p = .01), at 15W was significantly greater than monopolar coagulation at 10W and monopolar cut at 10, 20, and 30W (p ≤.01), and increased proportional to power for all 3 energy types. Collateral thermal damage width at all laser power settings was significantly less than at all monopolar coagulation power settings (p ≤.04) with the exception of the laser at 15W compared with monopolar coagulation at 10W (p = .30), and at all laser power settings was significantly less than at all monopolar coagulation power settings (p <.001). Collateral thermal damage depth of the laser at 5W and 10W was significantly less than monopolar cut at 30W (p ≤.002) and increased proportional to power in monopolar coagulation mode but remained constant with the laser. Incising efficiency of the laser at 5W was significantly greater than monopolar coagulation at 10W (p = .04), at 10W was significantly greater than at all monopolar power settings (p ≤.007) except cut at 40W (p = .29), and at 15W was significantly greater than that of every other energy type and power setting tested (p ≤.04). These findings support the hypothesis that CO2 laser energy delivered via a flexible fiber system would exhibit greater surgical precision than monopolar electrosurgery, in both cut and coagulation modes, as defined by 3 parameters: incising efficiency, changes in incision depth compared with width as power increases, and variability in the resulting incision measurements. Because increased thermal damage has been associated with delayed tissue necrosis and adhesion formation, these findings prompt the design of a comparative survival animal study to assess additional clinically relevant parameters.

In Vitro and In Vivo Investigation of the Influence of Implant Surface on the Formation of Bacterial Biofilm in Mammary Implants

Capsular contracture remains the most common complication following breast augmentation surgery, and evidence suggests that bacterial biofilm on the implant surface is responsible. The authors investigated whether the interaction of bacterial biofilm with implants independently determines progression to capsule formation. They also studied the rate of bacterial growth and adhesion to implants. Sixteen adult female pigs had 121 breast implants inserted. Sixty-six implants-23 smooth and 43 textured-were inoculated with a human strain of Staphylococcus epidermidis and received no other treatment. After an average period of 19 weeks, Baker grading was performed and implants were retrieved. For the in vitro study, samples underwent both quantitative bacterial analysis and imaging using confocal laser scanning and scanning electron microscopy. At explantation, there was no significant difference (p = 1.0) in the presence of capsular contracture (Baker grade III and IV) between smooth (83 percent) and textured implants (84 percent). Biofilm was confirmed on 60 of the 66 capsules. Capsules from smooth and textured implants had the same number of infecting bacteria (textured: 3.01 × 10 bacteria/g; smooth: 3.00 × 10 bacteria/g). In vitro, the surface of textured implants showed 11-, 43-, and 72-fold more bacteria at 2, 6, and 24 hours, respectively, compared with smooth implants (p < 0.001). These findings were confirmed by imaging analysis. These results show that textured implants develop a significantly higher load of bacterial biofilm in comparison with smooth implants. Furthermore, in vivo, once a threshold of biofilm forms on either smooth or textured implant surfaces, there seems to be an equal propensity to progress to capsular contracture.

Transgene delivery to endothelial cultures derived from porcine carotid artery ex vivo.

Carotid artery disease is a widespread cause of morbidity and mortality. Porcine models of vascular disease are well established in vivo, but existing endothelial systems in vitro (e.g. human umbilical vein endothelial cells, rat aortic endothelial cultures) poorly reflect carotid endothelium. A reliable in vitro assay would improve design of in vivo experiments and allow reduction and refinement of animal use. This study aimed (1) to develop ex vivo endothelial cultures from porcine carotid and (2) to test whether these were suitable for lentivector-mediated transgene delivery. Surplus carotid arteries were harvested from young adult female Large White pigs within 10 min post-mortem. Small sectors of carotid artery wall (approximately 4 mm×4 mm squares) were immobilised in a stable gel matrix. Cultures were exposed to HIV-derived lentivector (LV) encoding a reporter transgene or the equivalent integration-deficient vector (IDLV). After 7-14 days in vitro, cultures were fixed and labelled histochemically. Thread-like multicellular outgrowths were observed that were positive for endothelial cell markers (CD31, VEGFR2, von Willebrand factor). A minority of cells co-labelled for smooth muscle markers. Sensitivity to cytotoxic agents (paclitaxel, cycloheximide, staurosporine) was comparable to that in cell cultures, indicating that the gel matrix permits diffusive access of small pharmacological molecules. Transgene-expressing cells were more abundant following exposure to LV than IDLV (4.7, 0.1% of cells, respectively). In conclusion, ex vivo adult porcine carotid artery produced endothelial cell outgrowths that were effectively transduced by LV. This system will facilitate translation of novel therapies to clinical trials, with reduction and refinement of in vivo experiments.

The correlation between mineralization degree and bone tissue stiffness in the porcine mandibular condyle

The aim of this study was to correlate the local tissue mineral density (TMD) with the bone tissue stiffness. It was hypothesized that these variables are positively correlated. Cancellous and cortical bone samples were derived from ten mandibular condyles taken from 5 young and 5 adult female pigs. The bone tissue stiffness was assessed in three directions using nanoindentation. At each of three tested sides 5 indents were made over the width of 5 single bone elements, resulting in a total number of 1500 indents. MicroCT was used to determine the local TMD at the indented sites. The TMD and the bone tissue stiffness were higher in bone from the adult animals than from the young ones, but did not differ between cancellous and cortical bone. In the adult group, both the TMD and the bone tissue stiffness were higher in the center than at the surface of the bone elements. The mean TMD, thus ignoring the local mineral distribution, had a coefficient of determination (R(2)) with the mean bone tissue stiffness of 0.55, p < 0.05, whereas the correlation between local bone tissue stiffness and the concomitant TMD appeared to be weak (R (2) 0.07, p < 0.001). It was concluded that the mineralization degree plays a larger role in bone tissue stiffness in cancellous than in cortical bone. Our data based on bone from the mandibular condyle suggest that the mineralization degree is not a decisive determinant of the local bone tissue stiffness.

1825 INTRAVENOUS GLUCOSE TOLERANCE TEST ASSESSMENT OF GLUCOSE-INSULIN KINETICS FOLLOWING TREATMENT OF THE KIDNEY WITH A SUPRA-MAXIMAL DOSE OF SHOCK WAVES IN A PORCINE MODEL OF METABOLIC SYNDROME

INTRODUCTION AND OBJECTIVES: In our continuing efforts to determine whether shock wave lithotripsy (SWL) is a risk factor for the development of diabetes mellitus, we treated the kidney of metabolic syndrome (MetS) pigs with a supra-maximal dose of shock waves (SWs) and assessed the SWL effect on the glucose-insulin kinetic response to an intravenous glucose tolerance test (IVGTT). METHODS: Adult female Ossabaw pigs (9-month-old) were fed an excess calorie atherogenic diet to induce MetS. At 15 months of age, the MetS pigs underwent SWL treatment (4000 SWs, 24 kV at 120 SWs/min using the HM-3 lithotripter; n 7). SWs were targeted to the upper pole calyx of the left kidney because of its close association with the tail of the pancreas?a segment rich in insulin containing -cells. IVGTTs were performed on conscious, fasting MetS pigs before SWL and at 1-month and 2-months post-SWL with frequent blood samples taken for glucose and insulin measurement. RESULTS: Pigs fed an excess calorie atherogenic diet developed features of MetS: obesity, dyslipidemia, insulin resistance and glucose intolerance. Fasting levels of plasma glucose and insulin, as well as their response profile to IVGTTs, were similar before and after SWL. Estimates of insulin resistance, glucose tolerance and pancreatic beta cell function derived from the glucose-insulin kinetics calculated from IVGTTs were not significantly altered following SWL. CONCLUSIONS: The pig?s MetS status was unchanged following overtreatment of the kidney with 4000 high-energy SWs. These findings do not support a single session of SWL in MetS patients as a risk factor for the onset of diabetes mellitus?at least in the short-term.

A Diet High in Resistant Starch Modulates Microbiota Composition, SCFA Concentrations, and Gene Expression in Pig Intestine

Resistant starch (RS) is highly fermentable by microbiota in the colon, resulting in the production of SCFAs. RS is thought to mediate a large proportion of its health benefits, including increased satiety, through the actions of SCFAs. The aim of this study was to investigate the effects of a diet high in RS on luminal microbiota composition, luminal SCFA concentrations, and the expression of host genes involved in SCFA uptake, SCFA signaling, and satiety regulation in mucosal tissue obtained from small intestine, cecum, and colon. Twenty adult female pigs were either assigned to a digestible starch (DS) diet or a diet high in RS (34%) for a period of 2 wk. After the intervention, luminal content and mucosal scrapings were obtained for detailed molecular analysis. RS was completely degraded in the cecum. In both the cecum and colon, differences in microbiota composition were observed between DS- and RS-fed pigs. In the colon these included the stimulation of the healthy gut-associated butyrate-producing Faecalibacterium prausnitzii, whereas potentially pathogenic members of the Gammaproteobacteria, including Escherichia coli and Pseudomonas spp., were reduced in relative abundance. Cecal and colonic SCFA concentrations were significantly greater in RS-fed pigs, and cecal gene expression of monocarboxylate transporter 1 (SLC16A1) and glucagon (GCG) was induced by RS. In conclusion, our data show that RS modulates microbiota composition, SCFA concentrations, and host gene expression in pig intestine. Combined, our data provide an enhanced understanding of the interaction between diet, microbiota, and host.

Purification of swine carbonic anhydrase isoenzymeIIIand measurement of its levels in tissues and plasma

The changes in the levels of carbonic anhydrase isozyme III (CA-III) in swine plasma and urine have not been previously determined or reported. CA-III is relatively specific to skeletal muscles, and should therefore be a useful diagnostic marker for muscle diseases. We isolated CA-III from swine muscle tissues and determined CA-III levels in the plasma and urine from both healthy and diseased pigs. The levels of CA-III in the tissues of female swine (age, 3months) and plasma of young swine (age, 1-5months) and adult female pigs (age, 2-3years) were determined using the ELISA system for swine CA-III. The mean (±SD) levels of CA-III in the skeletal muscles were 3.8±3.2mg/g (wet tissue), and in the plasma, 230±193ng/ml at 1month, 189±208ng/ml at 2months, 141±148ng/ml at 3months, 78±142ng/ml at 4months and 53±99ng/ml at 5months. The mean level of CA-III in the plasma samples from 2- to 3-year-old pigs was 18±60ng/ml. CA-III in the plasma samples was found to decrease from 1month until 3years of age (p<0.01). We performed far-western blotting to clarify the cause of the observed decrease in CA-III in plasma. Our results demonstrated that CA-III is bound to the transferrin and albumin. In addition, we determined that the levels of CA-III in plasma and urine samples were higher in diseased swine compared with the healthy pigs.

Effects of dietary fibers with different fermentation characteristics on feeding motivation in adult female pigs

Dietary fibers can be fermented in the colon, resulting in production of short-chain fatty acids (SCFA) and secretion of satiety-related peptides. Fermentation characteristics (fermentation kinetics and SCFA-profile) differ between fibers and could impact their satiating potential. We investigated the effects of fibers with varying fermentation characteristics on feeding motivation in adult female pigs. Sixteen pair-housed pigs received four diets in four periods in a Latin square design. Starch from a control (C) diet was exchanged, based on gross energy, for inulin (INU), guar gum (GG), or retrograded tapioca starch (RS), each at a low (L) and a high (H) inclusion level. This resulted in a decreased metabolizable energy intake when feeding fiber diets as compared with the C diet. According to in vitro fermentation measurements, INU is rapidly fermentable and yields relatively high amounts of propionate, GG is moderately rapidly fermentable and yields relatively high amounts of acetate, and RS is slowly fermentable and yields relatively high amounts of butyrate. Feeding motivation was assessed using behavioral tests at 1h, 3h and 7h after the morning meal, and home pen behavioral observations throughout the day. The number of wheel turns paid for a food reward in an operant test was unaffected by diet. Pigs on H-diets ran 25% slower for a food reward in a runway test than pigs on L-diets, and showed less spontaneous physical activity and less stereotypic behavior in the hours before the afternoon meal, reflecting increased interprandial satiety. Reduced feeding motivation with increasing inclusion level was most pronounced for RS, as pigs decreased speed in the runway test and tended to have a lower voluntary food intake in an ad libitum food intake test when fed RS-H. In conclusion, increasing levels of fermentable fibers in the diet seemed to enhance satiety in adult pigs, despite a reduction in metabolizable energy supply. RS was the most satiating fiber, possibly due to its slow rate of fermentation and high production of butyrate.

Transdermal Delivery of Adipocyte-Derived Stem Cells Using a Fractional Ablative Laser

Chronic wound healing problems can pose a significant clinical challenge. Transdermal delivery of adipose-derived stem cells (ADSC) may be a possible solution to healing these recalcitrant, debilitating wounds. Pretreatment of the skin with a fractionated laser has already been shown to assist transdermal drug delivery both in vitro and in vivo and may be an ideal approach to facilitating delivery of ADSC to the target tissue. The authors investigate in a porcine model whether ADSC can be delivered transdermally following pretreatment with a fractional laser. After ethics approval was obtained, the abdomens of 2 adult female domestic pigs were pretreated with an erbium:YAG fractionated ablative laser. Following laser treatment, 20 × 10(6) bromodeoxyuridine (BrdU)-labeled ADSC were applied topically to the first animal for 4 hours. The same number of BrdU-labeled ADSC was applied to the second animal for 48 hours. The animals were euthanized at the end of their respective treatment periods, and the BrdU-labeled ADSC were counted after tissue harvest. At 4 hours, an average of 2.40 × 10(6) cells, or 12.0% of the total cells applied, were found in the tissue. At 48 hours, an average of 1.1 × 10(6) cells, or 5.5% of the total cells applied, were seen. This pilot study demonstrates that ADSC can be delivered transdermally through skin that has been pretreated with a laser. Potential future applications of this approach might include wound-healing or aesthetic indications. Further studies need to be conducted to determine the optimal number of ADSC to use in this approach, the best methods of application, and the effect of transdermally delivered ADSC on wound healing.

Abstract 19552: Exercise-Induced Changes in Mechanotransduction Improve Myocardial Function in a Porcine Model of Chronic Occlusion

Introduction: Exercise training has been shown to improve cardiac dysfunction both in patients and animal models of coronary artery disease; however, the underlying cellular and molecular mechanisms have not been completely understood. Transmembrane integrins that connect the extracellular matrix (ECM) and intracellular cytoskeleton are important for mechanotransduction in cardiomyocytes. Hypothesis: The binding probability and adhesion force between integrins-ECM, and their subsequent signaling that is cell stiffness will be increased in the myocytes from exercise-trained animals when compared to the sedentary group. Methods: Ameroid occluders were surgically placed around the proximal left circumflex coronary artery of adult female Yucatan pigs. Twenty-two weeks postoperatively, myocardium was isolated from non-occluded and collateral-dependent regions of sedentary and exercise trained (treadmill run; 5 days/wk for 14 wks) pigs. We used atomic force microscopy for measuring cell stiffness and adhesion force between integrin and fibronectin (FN) in pig cardiomyocytes. In addition, integrins and FN expression were determined. Results: While exercise-trained pigs showed an increase in β1 integrin expression, β3 integrin expression was detected at an increased level in the sedentary myocardium. An increase in the amount of total FN and its fragments were found in the myocardium from collateral-dependent regions of exercise-trained and sedentary pigs when compared to the non-occluded myocardium regions. The peak bond rupture force of FN-integrin (46.4±0.3 pN vs 34.8±0.2 pN), the probability of adhesion (72% vs 54%) and cell stiffness (67.9±4.7 kPa vs 29.0±1.8 kPa) were significantly increased (p&lt;0.05; n=10) in myocytes from exercise-trained pigs when compared to sedentary hearts, which were prevented by function blocking α5 and αv integrin antibodies, respectively. Conclusion: Our data demonstrate that the differences seen in adhesion force, probability and stiffness between the sedentary and exercise-trained myocytes are due to interactions of FN to different integrins, e.g., αvβ3 in sedentary and α5β1 in exercise-trained cells, suggesting potential importance of mechanotransduction pathway for therapeutic development.

Direct Comparison of Percutaneous Circulatory Support Systems in Specific Hemodynamic Conditions in a Porcine Model

Several percutaneous circulatory support systems have been recently introduced into clinical practice for the treatment of cardiogenic shock or refractory nontolerated ventricular tachycardia, in support of high-risk catheter interventions and, occasionally, cardiopulmonary resuscitation. To date, however, a direct comparison of the available systems has not been performed. Adult female pigs (weight 50-60 kg) were used throughout the experiment. Under deep anesthesia and mechanical ventilation, 3 percutaneous circulatory support systems were compared: (1) right atrium-aorta, extracorporeal membrane oxygenation (n=4); (2) left atrium-aorta, TandemHeart system (n=4); (3) left ventricle-aorta, Impella 2.5 system (n=4), and (4) left ventricle-aorta with norepinephrine at 0.1 µg/kg per minute (n=4). Hemodynamic efficacy (mean arterial pressure) was measured at 3 specific conditions: ventricular pacing at 200 and 300 beats per minute, and ventricular fibrillation. Although no or only nonsignificant differences were found among the systems at ventricular pacing of 200 and 300 beats per minute, under ventricular fibrillation, the right atrium-aorta system was significantly the most efficacious, followed by the left atrium-aorta system and the left ventricle-aorta system (P<0.001). However, the left ventricle-aorta system with norepinephrine still maintained mean arterial pressure comparable with the left atrium-aorta system. Differences were seen in the hemodynamic efficacy of available percutaneous circulatory support systems, particularly under the most severe hemodynamic condition, ventricular fibrillation.

Prevention of Biofilm-Induced Capsular Contracture With Antibiotic-Impregnated Mesh in a Porcine Model

A growing body of evidence implicates subclinical (biofilm) infection around breast implants as an important cause of capsular contracture (CC). The authors use an in vivo porcine model to investigate the potential of antibiotic-impregnated mesh as a prophylactic measure against biofilm formation and CC. A total of 28 implants (14 untreated controls, 14 treated with antibiotic mesh) were inserted into 5 adult female pigs. All implants and pockets were inoculated with a human clinical strain of Staphylococcus epidermidis. The implants were left in situ for 16 weeks and then analyzed for contracture using both Baker grading and applanation tonometry. The presence of biofilm infection was assessed by subsequent microbiological analysis of implants and capsules. One untreated implant had extruded and was excluded from analysis. The tissue surrounding the 13 untreated control implants had Baker Grade III/IV CC, whereas no CC was identified around the 14 antibiotic mesh-treated implants. This difference was highly significant (P < .001). Tonometry findings were consistent with the Baker assessments. Although bacterial biofilm was detected on all implants and capsules, the biofilms on the antibiotic-treated implants and surrounding capsules were generally single-layered or isolated in contrast to the multilayer biofilms found on untreated implants and capsules. Based on the findings from this study of a porcine model, the use of antibiotic-impregnated mesh reduces bacterial access to breast implants at the time of surgical insertion and may subsequently protect against subclinical infection and CC.

Altered Expression of Porcine Piwi Genes and piRNA during Development

Three Sus scrofa Piwi genes (Piwil1, Piwil2 and Piwil4) encoding proteins of 861, 985 and 853 aminoacids, respectively, were cloned and sequenced. Alignment of the Piwi proteins showed the high identity between Sus scrofa and Homo sapiens. Relative transcript abundance of porcine Piwil1, Piwil2 and Piwil4 genes in testes, ovaries and oocytes derived from sexually immature and mature animals was examined using Real-Time PCR. Expression of the three Piwi mRNAs was proved to be tissue specific and restricted exclusively to the gonads. In testes of adult pigs the highest relative transcript abundance was observed for the Sus scrofa Piwil1 gene. On the other hand, in testes of neonatal pigs the Piwil1 transcript level was over 2–fold reduced while the level of Piwil2 transcript was higher. As regards the expression of the Piwil4 transcript, its level was 34-fold elevated in testes of neonatal piglet when compared to adult male. In ovaries of prepubertal and pubertal female pigs transcript abundance of the three Piwi genes was significantly reduced in comparison with testes. However, similarly to testes, in ovaries of neonatal pigs the Piwil2 gene was characterized by the highest relative transcript abundance among the three Piwi genes analysed. In prepubertal and pubertal oocytes Piwil1 transcript was the most abundant whereas the expression of Piwil4 was undetectable. We also demonstrated that expression of piRNA occurs preferentially in the gonads of adult male and female pigs. Moreover, a piRNA subset isolated from ovaries was 2–3 nucleotides longer than the piRNA from testes.

An animal model to train Lichtenstein inguinal hernia repair

Inguinal hernia repair is a common surgical procedure, and the majority of operations worldwide are performed ad modum Lichtenstein (open tension-free mesh repair). Until now, no suitable surgical training model has been available for this procedure. We propose an experimental surgical training model for Lichtenstein's procedure on the male and female pig. In the pig, an incision is made 1cm cranially to the inguinal sulcus where a string of subcutaneous lymph nodes is located and extends toward the pubic tubercle. The spermatic cord is located in a narrow sulcus in the pig, thus complicating the procedure if operation should be done in the inguinal canal. The chain of lymph nodes resembles the human spermatic cord and can be used to perform Lichtenstein's hernia repair. This experimental surgical model has been tested on two adult male pigs and three adult female pigs, and a total of 55 surgeons have been educated to perform Lichtenstein's hernia repair in these animals. This new experimental surgical model for training Lichtenstein's hernia repair mimics the human inguinal anatomy enough to make it suitable as a training model. The operation facilitates the training in the positioning and fixation of the mesh and can be performed numerous times on the same pig. It is therefore a useful training method for inexperienced surgeons to obtain experience in aspects of the Lichtenstein procedure.

Evaluation of bacterial contamination after “pure” (totally) transvaginal NOTES® diagnostic peritoneoscopy with biopsies in swine: a comparative study with laparoscopy

Bacterial contamination from viscerotomy is a barrier to natural orifice translumenal endoscopic surgery (NOTES). The aim of this survival study is to evaluate pure (totally) transvaginal NOTES bacterial contamination compared with laparoscopy in pigs. Twelve adult female pigs underwent peritoneoscopy with liver and peritoneal biopsies, using either laparoscopy (Glap, six animals) or pure transvaginal (GNOTES) access, and were maintained alive for 7 days. In all animals, blood cultures were taken at baseline, and after 24 h and 7 days postoperatively. Swab cultures from vagina (GNOTES) and skin (Glap) were obtained pre- and post-antisepsis. Peritoneal fluid culture was obtained at necropsy. For statistical analysis, Glap and GNOTES were compared for presence of positive bacterial cultures (qualitative bacterial analysis) using Fisher's test, with level of significance set at p < 0.05. All animals had good postoperative outcome. One animal had transient perioperative bleeding from a transvaginal access. Two animals in Glap and one in GNOTES had positive blood cultures after the procedure. All animals from GNOTES and Glap presented with mixed flora pre-antisepsis. After antisepsis, one animal (GNOTES) presented with a positive vaginal swab culture (a single bacterial strain was identified). There was no positive skin swab culture in Glap. There were no signs of intra-abdominal infection at necropsy. In two animals, one from Glap and another from GNOTES, intra-abdominal culture was positive for Corynebacterium spp. and Escherichia coli, respectively. There was no correlation between the bacterial flora found at the access site and in the peritoneal cultures. Pure transvaginal peritoneoscopy with liver and peritoneal biopsy in swine is feasible and associated with bacterial contamination comparable to laparoscopy. Peritoneal bacterial contamination was clinically insignificant after 1 week postoperatively. Preoperative antisepsis provided significant reduction of bacterial load prior to transvaginal and laparoscopic procedures.

Effects of dietary fibers with different physicochemical properties on feeding motivation in adult female pigs

The satiating effects of dietary fiber may depend more on physicochemical properties of the fiber than on total fiber intake. These properties are expected to affect satiety feelings and feeding motivation due to different effects in the gastrointestinal tract. The aim of the current study was to assess the effects of fibers with varying physicochemical properties (bulkiness, viscosity and fermentability) on feeding motivation in adult female pigs. Sixteen pair-housed pigs received four diets: lignocellulose (LC), pectin (PEC), resistant starch (RS), and control (C) without fiber, in four periods in a Latin square design. Each fiber was fed at a low (L) followed by a high (H) inclusion level (7days each). At 1h, 3h, and 7h after the morning meal, feeding motivation was assessed in an operant test, where turning a wheel yielded multiple food rewards, and in a runway test, where walking a fixed U-shaped track yielded one food reward. Pigs were observed in their home pen for 6h, using 90-s instantaneous scan sampling. In the operant test, throughout the day feeding motivation was higher for pigs on PEC compared with pigs on LC. In the runway, feeding motivation increased particularly at 1h after the meal for pigs on PEC compared with pigs on RS. Also at 7h, feeding motivation tended to decrease for pigs on RS compared with pigs fed other diets. In their home pen, pigs on PEC showed more feeder-directed behavior compared with pigs on RS. In conclusion, PEC was the least satiating fiber. LC and RS, despite a lower supply of available energy, were the most satiating fibers, possibly due to their bulky and fermentation properties, respectively.

Experimental Administration of the Probiotic Escherichia coli Strain Nissle 1917 Results in Decreased Diversity of E. coli Strains in Pigs

The strain Escherichia coli Nissle 1917 (EcN) is widely used as an efficient probiotic in therapy and prevention of human infectious diseases, especially of the intestinal system. Concurrently, small adult pigs are being used as experimental omnivore models to study human gastrointestinal functions. EcN bacteria were applied to 6 adult healthy female pigs in a 2-week trial. 6 Control animals remained untreated. Altogether, 164 and 149 bacterial strains were isolated from smear samples taken from gastrointestinal mucosa in the experimental and control group, respectively. Each individual E. coli strain was then tested for the presence of 29 bacteriocin-encoding determinants as well as for DNA markers of A, B1, B2 and D phylogenetic groups. A profound reduction of E. coli genetic variance (from 32 variants to 13 ones, P=0.0006) was found in the experimental group, accompanied by a lower incidence of bacteriocin producers in the experimental group when compared to control (21.3 and 34.9%, respectively; P=0.007) and by changes in the incidence of individual bacteriocin types. The experimental administration of EcN strain was not sufficient for stable colonization of porcine gut, but induced significant changes in the enterobacterial microbiota.

Ca2+ sensitization of cardiac myofilament proteins contributes to exercise training-enhanced myocardial function in a porcine model of chronic occlusion

Exercise training has been shown to improve cardiac dysfunction in both patients and animal models of coronary artery disease; however, the underlying cellular and molecular mechanisms have not been completely understood. We hypothesized that exercise training would improve force generation in the myocardium distal to chronic coronary artery occlusion via altered intracellular Ca(2+) concentration ([Ca(2+)](i)) cycling and/or Ca(2+) sensitization of myofilaments. Ameroid occluders were surgically placed around the proximal left circumflex coronary artery of adult female Yucatan pigs. Twenty-two weeks postoperatively, the myocardium was isolated from nonoccluded (left anterior descending artery dependent) and collateral-dependent (formerly left circumflex coronary artery dependent) regions of sedentary (pen confined) and exercise-trained (treadmill run, 5 days/wk for 14 wk) pigs. Force measurements in myocardial strips showed that the percent change in force at stimulation frequencies of 3 and 4 Hz relative to 1 Hz was significantly higher in exercise-trained pigs compared with sedentary pigs. β-Adrenergic stimulation with dobutamine significantly improved force kinetics in myocardial strips of sedentary but not exercise-trained pigs at 1 Hz. Additionally, time to peak and half-decay of intracellular Ca(2+) (340-to-380-nm fluoresence ratio) responses at 1 Hz were significantly decreased in the collateral-dependent region of exercise-trained pigs with no difference in peak [Ca(2+)](i) between groups. Furthermore, the skinned myocardium from exercise-trained pigs showed an increase in Ca(2+) sensitivity compared with sedentary pigs. Immunoblot analysis revealed that the relative levels of cardiac troponin T and β(1)-adrenergic receptors were decreased in hearts from exercise-trained pigs independent of occlusion. Also, the ratio of phosphorylated to total myosin light chain-2, basal phosphorylation levels of cardiac troponin I (Ser(23) and Ser(24)), and cardiac myosin binding protein-C (Ser(282)) were unaltered by occlusion or exercise training. Thus, our data demonstrate that exercise training-enhanced force generation in the nonoccluded and collateral-dependent myocardium was associated with improved Ca(2+) transients, increased Ca(2+) sensitization of myofilament proteins, and decreased expression levels of β(1)-adrenergic receptors and cardiac troponin T.

Exercise training restores contractility in collateral‐dependent myocardium via calcium sensitization of myofilament proteins and changes in phosphorylation of cardiac troponin I (cTnI)

Exercise training has been shown to improve cardiac dysfunction in patients and animal models of coronary artery disease, yet underlying mechanisms have not been elucidated. We hypothesized that exercise training would improve force generation in myocardium distal to chronic coronary artery occlusion via calcium sensitization of myofilaments. Ameroid constrictors were surgically placed around the proximal left circumflex coronary (LCx) artery of adult female Yucatan pigs. Twenty-two weeks postoperatively, myocardium was isolated from control (left anterior descending artery-dependent) and collateral-dependent (formerly LCx-dependent) regions of sedentary (Sed; pen-confined) and exercise-trained (Ex; treadmill; 5 days/wk for 14 wks) pigs. Force measurements in myocardial strips revealed that percent change in force generated at 4 vs. 1 Hz and 3 vs. 1 Hz was significantly higher in collateral-dependent region of Ex vs. Sed. Concurrent studies showed calcium sensitization of myofilaments from collateral-dependent region of Ex. Dobutamine treatment of myocardial strips at 1 Hz significantly improved force kinetics in Sed vs. Ex. Basal phosphorylation levels of cTnI (Ser 22, 23) tended to be elevated in Ex. Thus, calcium sensitization of myofilament proteins in collateral-dependent myocardium and phosphorylation levels of cTnI augment force generation in myocardial strips of Ex pigs. NIH HL064931