Male Minipigs Research Articles

Approachability and Sensory Changes Following Mild Traumatic Brain Injury in Pigs

Background/Objectives: Traumatic brain injury (TBI) is a global healthcare concern affecting millions, with wide-ranging symptoms including sensory and behavioral changes that can persist long-term. Due to similarities with human brain cytoarchitecture and inflammation, minipig models are advantageous for translational TBI research. However, gaps in knowledge exist regarding their behavioral and sensory sequelae following injury. Methods: Therefore, in this study, we assessed changes in approachability using a forced human approach task (FHAT) and mechanical nociception using the von Frey test in adult male and female Yucatan minipigs for up to one week following a sham or central fluid percussion injury (cFPI). Specifically, the FHAT assessed each animal’s response to a forced interaction with either a known or unknown experimenter. To evaluate changes in nociceptive sensory sensitivity, von Frey monofilaments ranging from 0.008 to 300 g of force were applied to the pinna of the ear or base of the tail. Results: We found that forced approachability was affected by experimenter familiarity as well as cFPI in a sex-specific manner at subacute timepoints. We also found reductions in sensitivity following cFPI on the ear in male minipigs and on the tail in female minipigs. Conclusion: Overall, the current study demonstrates that cFPI produces both behavioral and sensory changes in minipigs up to one-week post-injury.

Assessment of basic pharmacokinetic parameters of dapagliflozin in TTS formulations in male minipigs

Given the extended time over which diabetes treatment is administered, the transdermal delivery system is anticipated to be a more suitable option for older individuals who may experience difficulty swallowing. The continuous delivery of dapagliflozin and more stable plasma levels are anticipated to reduce the incidence of side effects and the frequency of dosing. The objectives of the study were to determine the safety and plasma pharmacokinetics of dapagliflozin in male minipigs following application of the ointment and skin patch. In the initial phase of the study, the potential for transdermal permeation of dapagliflozin from ointment and transdermal patch to blood plasma of 15 male Göttingen minipigs was investigated. In the subsequent phase, the efficacy of utilising patches of varying strengths and sizes was assessed. The LC/MS method was employed to quantify the concentration of the active substance. The transportation of the studied API to the general circulation and accumulation in tissues were confirmed. The maximum drug concentration (122.99 ng/mL) in plasma was observed on the fourth day of application. The highest calculated Cmax was 131.91 ng/mL with a mean AUC0-last of 6620.7 ng h/mL. Following transdermal administration, dapagliflozin is excreted in the urine. The trend between urinary dapagliflozin 3-O-glucuronide levels and urinary glucose excretion was also observed. The transdermal patch has been demonstrated to be an effective drug delivery system for dapagliflozin.

Rheological and Lipid Characterization of Minipig and Human Skin Tissue: A Comparative Study Across Different Locations and Depths.

Understanding the rheology of minipig and human skin is crucial for enhancing drug delivery methods, particularly for injections. Despite many studies on skin's viscoelasticity, especially the subcutaneous layer, comparative analyses across different clinical sites are scarce, as is data on the impact of hydration or lipid levels. This study employs shear rheology and lipid analysis to evaluate viscoelasticity and lipid content across three anatomical locations-breast, belly, and neck and three different depth layers in Yucatan minipigs. It reports on how viscoelastic properties change with frequency, time, and strain, noting strain-stiffening and shear-thinning at high strain amplitudes. Human male and female abdominal tissues are also compared to minipig tissues, highlighting distinct viscoelastic traits and lipid's role in them. The findings suggest the existence of species, anatomical location, tissue depth, and sex-based rheological differences.Furthermore, the use of male minipig models for studying human male subcutaneous tissue is discussed.

High fat diet is associated with gut microbiota dysbiosis and decreased gut microbial derived metabolites related to metabolic health in young Göttingen Minipigs.

The objectives were 1) to characterize a Göttingen Minipig model of metabolic syndrome regarding its colon microbiota and circulating microbial products, and 2) to assess whether ovariectomized female and castrated male minipigs show similar phenotypes. Twenty-four nine-week-old Göttingen Minipigs were allocated to four groups based on sex and diet: ovariectomized females and castrated males fed either chow or high-fat diet (HFD) for 12 weeks. At study end, body composition and plasma biomarkers were measured, and a mixed meal tolerance test (MMT) and an intravenous glucose tolerance test (IVGTT) were performed. The HFD groups had significantly higher weight gain, fat percentage, fasting plasma insulin and glucagon compared to the chow groups. Homeostatic model assessment of insulin resistance index (HOMA-IR) was increased and glucose effectiveness derived from the IVGTT and Matsuda´s insulin sensitivity index from the MMT were decreased in the HFD groups. The HFD groups displayed dyslipidemia, with significantly increased total-, LDL- and HDL-cholesterol, and decreased HDL/non-HDL cholesterol ratio. The colon microbiota of HFD minipigs clearly differed from the lean controls (GuniFrac distance matrix). The main bacteria families driving this separation were Clostridiaceae, Fibrobacteraceae, Flavobacteriaceae and Porphyromonadaceae. Moreover, the species richness was significantly decreased by HFD. In addition, HFD decreased the circulating level of short chain fatty acids and beneficial microbial metabolites hippuric acid, xanthine and trigonelline, while increasing the level of branched chain amino acids. Six and nine metabolically relevant genes were differentially expressed between chow-fed and HFD-fed animals in liver and omental adipose tissue, respectively. The HFD-fed pigs presented with metabolic syndrome, gut microbial dysbiosis and a marked decrease in healthy gut microbial products and thus displayed marked parallels to human obesity and insulin resistance. HFD-fed Göttingen Minipig therefore represents a relevant animal model for studying host-microbiota interactions. No significant differences between the castrated and ovariectomized minipigs were observed.

Comparison of the fecal bacterial microbiota in mice, rats, and pigs after oral administration of alpha-glycosyl isoquercitrin.

Alpha-glycosyl isoquercitrin (AGIQ) is composed of isoquercitrin and its glucosylated derivatives and has many biological activities, including anti-inflammatory, antioxidant, and anti-cancer properties. However, the effect of AGIQ administered orally on gut microbiota composition remains unclear. The objective of this study was to evaluate the effect of AGIQ on the gut microbiota of animals in different dose groups. Male rats and mice received different doses of AGIQ (1.5%, 3%, or 5% w/v) in diet for carcinogenic or chronic toxicity studies (rasH2 mice: 6 months; Sprague-Dawley rats: 12 months). Male minipigs received 100, 300, or 1000 mg/kg/day for 28 days. Fecal samples were collected from the different animal species and analyzed using 16S-rRNA gene sequencing. No significant changes were observed in alpha and beta diversity of the gut microbiota. Characteristic bacteria that responded to AGIQ were identified in each animal species, and, interestingly, Kineothrix alysoides, a butyrate-producing bacterium, was commonly detected in all three species, suggesting that it may be related to the biological activities of AGIQ. AGIQ selectively modulated the number of beneficial butyrate-producing commensal bacterium beneficial bacteria without changing the diversity of gut microbiota, which further supports the safe use of AGIQ in food products.

Cardiovascular Response to Intraneural Right Vagus Nerve Stimulation in Adult Minipig

ObjectiveThis study explored intraneural stimulation of the right thoracic vagus nerve (VN) in sexually mature male minipigs to modulate safe heart rate and blood pressure response. Material and MethodsWe employed an intraneural electrode designed for the VN of pigs to perform VN stimulation (VNS). This was delivered using different numbers of contacts on the electrode and different stimulation parameters (amplitude, frequency, and pulse width), identifying the most suitable stimulation configuration. All the parameter ranges had been selected from a computational cardiovascular system model. ResultsClinically relevant responses were observed when stimulating with low current intensities and relatively low frequencies delivered with a single contact. Selecting a biphasic, charge-balanced square wave for VNS with a current amplitude of 500 μA, frequency of 10 Hz, and pulse width of 200 μs, we obtained heart rate reduction of 7.67 ± 5.19 beats per minute, systolic pressure reduction of 5.75 ± 2.59 mmHg, and diastolic pressure reduction of 3.39 ± 1.44 mmHg. ConclusionHeart rate modulation was obtained without inducing any observable adverse effects, underlining the high selectivity of the intraneural approach.

2-Oxidation, 3-methyl hydroxylation, and 6-hydroxylation of skatole, a contributor to the odour of boar-tainted pork meat, mediated by porcine liver microsomal cytochromes P450 1A2, 2A19, 2E1, and 3A22

The 2-oxidation, 3-methyl hydroxylation, and 6-hydroxylation of skatole (a contributor to boar taint) mediated by minipig liver microsomes and recombinant P450 enzymes expressed in bacterial membranes were investigated. At low substrate concentrations of 10 µM, the formation rates of indole-3-carbinol, 6-hydroxyskatole, and the sum of 3-methyloxindole, indole-3-carbinol, and 6-hydroxyskatole in male minipig liver microsomes were significantly lower than those in female minipig liver microsomes. Compensatory 3-methyloxindole and indole-3-carbinol formation in minipig liver microsomes, which lack 6-hydroxyskatole formation in males, was mediated partly by liver microsomal P450 1A2 and P450 1A2/2E1, respectively. These enzymes were suppressed by typical P450 inhibitors in female minipig liver microsomes. Among the 14 pig P450 forms evaluated, P450 2A19 was the dominant form mediating 3-methyloxindole, indole-3-carbinol, and 6-hydroxyskatole formation from skatole at substrate concentrations of 100 µM. Positive cooperativity was observed in 3-methyloxindole formation from skatole mediated by male minipig liver microsomes and by pig P450 3A22 with Hill coefficients of 1.2–1.5. These results suggest high skatole 2-oxidation, 3-methyl hydroxylation, and 6-hydroxylation activities of pig P450 2A19 and compensatory skatole oxidations mediated by pig P450 1A2, 2E1, or 3A22 in male minipig liver microsomes.

Prevention of Esophageal Stricture after Endoscopic Submucosal Dissection with an Autologous Esophageal Epithelial Cell Suspension: An Animal Study.

Severe esophageal stricture decreases patient's quality of life after circumferential endoscopic submucosal dissection (ESD). We aimed to evaluate the efficacy of autologous esophageal epithelial cell suspensions in preventing esophageal stricture after circumferential ESD. Twelve male mini-pigs underwent circumferential ESD and were randomized into four groups: G1 (control), G2 (esophageal stent), G3 (autologous esophageal epithelial cell suspension), and G4 (autologous esophageal epithelial cell suspension combined with esophageal stent). Post-ESD status was observed in each group, and endoscopy was performed weekly. Esophageal stents were removed 3 weeks after ESD. The esophageal stricture rates and histologic characteristics were assessed 4 weeks after ESD. G1 showed the greatest weight loss (p < 0.05). Dysphagia scores were not significantly different among the groups. The esophageal mucosal stricture rates were 77.7 ± 2.9%, 74.2 ± 1.9%, 69.2 ± 3.8% and 65.9 ± 1.9% in G1-4, respectively; with the highest in G1 (G1 vs. G3, p = 0.005; G1 vs. G4, p = 0.001). The regenerated epithelium lengths were 4.408 ± 1.980 mm, 8.319 ± 0.857 mm, 11.801 ± 2.455 mm and 12.353 ± 1.111 mm in G1-4, respectively. The lowest degree of re-epithelialization was observed in G1, followed by G2, with the highest degrees in G3 and G4 (G1 vs. G3, p = 0.001; G1 vs. G4, p = 0.000). The maximum wound fibrosis thicknesses were 2.546 ± 0.389 mm, 2.136 ± 0.231 mm, 1.126 ± 0.211 mm and 1.131 ± 0.438 mm in G1-4, respectively, with higher degrees in G1 and G2 than in G3 and G4 (G1 vs. G3, p = 0.001; G1 vs. G4, p = 0.001). Autologous esophageal epithelial cell suspensions can promote re-epithelialization and reduce fibrosis, thus decreasing esophageal stricture severity after ESD.

Imaging findings in a minipig with congenital portosystemic shunt.

A 15-month-old, male minipig was presented with a clinical history of seizure activity for one year. The minipig was the smallest among the littermates and was referred due to an elevated blood ammonia level with suspected portosystemic shunt (PSS). Ultrasound and CT angiography were consistent with a congenital extrahepatic PSS. To the author's knowledge, this is the first description of a congenital extrahepatic PSS diagnosed by ultrasound and contrast-enhanced computed tomography in a minipig (pig). Partial shunt closure was performed by interventional stent application.

Establishment of type 2 diabetes mellitus models using streptozotocin after 3 months high-fat diet in Bama minipigs

In the past twenty years, the number of adults with diabetes has tripled. Most studies have been conducted using rodent models of type 2 diabetes mellitus (T2DM), and the developed drugs have low clinical conversion efficiency. Therefore, it is urgent to establish a more human-like large animal model to explore T2DM pathogenesis and formulate new disease prevention and control strategies. This study was designed to establish and validate a T2DM model using minipigs fed a high-fat or high-cholesterol/high-fat diet and injected with low-dose streptozotocin (STZ). We examined the influence of the STZ injection timing with a diet high in fat (HFD) compared with one high in cholesterol and fat (HCFD) on the atherosclerotic lesions accelerated by T2DM. Male Bama minipigs (n = 24) were randomly divided into five groups. The control group was fed a normal diet for 9 months. The STZ + HFD and STZ + HCFD groups were infused with 90 mg/kg STZ and then fed a high-fat diet or high-cholesterol and high-fat diet for 9 months, respectively. The HFD + STZ and HCFD + STZ groups were fed a high-fat diet or a high-cholesterol and high-fat diet, respectively, for 9 months (after 3 months, these pigs were injected intravenously with 90 mg/kg STZ). During the induction period, animal body weight, BMI, and serum GLU, INS, TG, TC, HDL-C, LDL-C, FFA, ALT, AST, CRE, and BUN were detected monthly intervals. IVGTT and insulin release tests were performed at 3-month intervals. At the end of the test, the coronary artery and abdominal aorta were examined by computed tomography and pathological observations, and the thickness of the basement membrane of the capillary of the retina and kidney glomerulus was measured under a transmission electron microscope. The serum glucose concentrations were normal in all groups except the HFD + STZ and HCFD + STZ groups. Animals fed an HFD for 9 months did not develop apparent atherosclerotic lesions, but atherosclerotic lesions were seen in the animals fed an HCFD. Hyperglycemia accelerated the formation of atherosclerotic lesions on the intimal surface of the abdominal aorta. Low-dose STZ after 3 months of HFD or HCFD successfully established a T2DM model in minipigs. The HFD did not induce apparent atherosclerotic lesions, but these were seen with the HCFD. Hyperglycemia accelerated atherosclerosis in the minipigs.

Multiparametric CMR imaging of myocardial structure and function changes in diabetic mini-pigs with preserved LV function: a preliminary study

BackgroundThe purpose of this study is to dynamically monitor the myocardial structure and function changes in diabetic mini-pigs by 1.5 T cardiac magnetic resonance.MethodsThree male mini-pigs underwent cardiac magnet resonance (CMR) imaging, and histologic examination. T1-mapping was acquired at basal, mid and apical segments. CMR feature-tracking (CMR-FT) is used to quantify left ventricle global longitudinal (LVGLS), circumferential (LVGCS) and radial strain (LVGRS). Epicardial adipose tissue (EAT) was evaluated using a commercially available software.ResultsLeft ventricular mass (LVM), myocardial native T1 value, extracellular volume (ECV) value and EAT were increased gradually after 6 months of modeling, while LVGLS decreased gradually after 6 months of modeling (LVM: 24.5 (23.4, 26.7) vs. 42.7 (41.4, 44.6) g/m2, p < 0.001; Native T1: 1005.5 (992.6, 1010.7) vs. 1028.7 (1015.5, 1035.6) ms, p = 0.041; EAT: 16.1 (14.5, 18.2) vs. 24.6 (20.8, 26.9) mL, p = 0.020; ECV: 21.4 (20.2, 23.9) vs. 28.9 (26.7, 30.3) %, p = 0.011; LVGLS: − 22.8 (− 21.4, − 23.9) vs. − 17.4 (− 17.2, − 19.2)%, p = 0.008). The diffuse myocardial interstitial fibrosis was found in histology samples.ConclusionThe progressive impairments in LV structure and myocardial deformation occurs in diabetic mini-pigs. T1 mapping and CMR-FT technology are promising to monitor abnormal changes of diabetic myocardium in the early stage of diabetic cardiomyopathy.

PULP TISSUE MORPHOLOGY IN EXPERIMENTAL PULPITIS BY USING DIFFERENT MATERIALS FOR DIRECT PULP CAPPING

The minimally invasive concept of treatment in clinical medicine and, in particular, in dentistry is associated with the introduction of pulp-saving treatment technologies into clinical practice. The aim of the study was to identify the reaction of the structure of pulp tissues in traumatic pulpitis in the experiment using various means and techniques of direct pulp capping. The experiment was carried out on male minipigs aged 4–5 months with deciduous dentition. Milk molars were selected for trepanation. After teeth preparation under anesthesia, the crowns of the first and second milk premolars were trepanned on the vestibular surface in the cervical region with pulp probing until bleeding. After bleeding has been stopped, the trepanation hole was closed with various preparations. For direct pulp capping we used mineral trioxide aggregate (MTA) — containing silicate material and glass ionomer cement (GIC). All samples of teeth with experimental pulpitis using MTA-containing materials (Rutdent), tricalcium silicate materials (Biodentin) and even GIC (Vitremer) did not reveal inflammatory changes in the pulp tissues when they were directly covered with various materials. Of all the experimental samples of pulpitis, inflammation was detected with a sample of the Rutdent material with fragment damage to the pulp. With traumatic pulpitis and the use of various materials for direct pulp capping, active reparative regeneration of pulp tissue was revealed. All studied materials contribute to the reparation of the pulp after damage and reduction of pulp inflammation.

Combined Cardiopulmonary Assessments Using Impedance and Digital Implants in Conscious Freely Moving Cynomolgus Monkeys, Beagle Dogs, and Göttingen Minipigs: Pharmacological Characterization and Social Housing Effects.

Respiratory monitoring, using impedance with implanted telemetry in socially housed animals, was not possible until the recent development of digital signal transmission. The objective of this study was to evaluate digital telemetry monitoring of cardiopulmonary parameters (respiratory rate, tidal volume, minute volume, electrocardiography (DII), systemic arterial blood pressure, physical activity, and body temperature) in conscious, single-housed, non-rodent species commonly used in toxicology studies following administration of positive/negative controls (saline, dexmedetomidine, morphine, amphetamine, and doxapram), and also, the effects of various social housing arrangements in untreated female and/or male cynomolgus monkeys, Beagle dogs, and Göttingen minipigs (n = 4 per species). Aggressions were observed in socially housed male minipigs, however, which prevented pair-housed assessments in this species. All tested pharmacological agents significantly altered more than one organ system, highlighting important inter-organ dependencies when analyzing functional endpoints. Stress-related physiological changes were observed with single-housing or pair-housing with a new cage mate in cynomolgus monkeys and Beagle dogs, suggesting that stable social structures are preferable to limit variability, especially around dosing. Concomitant monitoring of cardiovascular and respiratory parameters from the same animals may help reduce the number of animals (3 Rs) needed to fulfill the S7A guidelines and allows for identification of organ system functional correlations. Globally, the data support the use of social housing in non-rodents for safety pharmacology multi-organ system (heart and lungs) monitoring investigations.

Effects of Cryofrequency in the Different Swine Skin Tissue Layers: &amp;lt;i&amp;gt;In Vitro&amp;lt;/i&amp;gt; and &amp;lt;i&amp;gt;in Vivo&amp;lt;/i&amp;gt; Study

Introduction: Cryofrequency is a novel therapy which was developed with the combination of cold (cryotherapy) and heat (radiofrequency) application, causing a thermal shock effect on skin tissue. The thermal shock is believed to alter local metabolism. Objective: To investigate the effect of cryofrequency on the skin tissue of a mini pig in an in vitro and in vivo experimental model. Methodology: A small swine of the S. domesticus species, a male mini-pig (30 kg weight) was elected for the in vivo procedure subject. The in vitro step was performed on the extracted abdominal part of another subject of the same species and breed. Then, after the application of cryofrequency in the monopolar and bipolar form in vivo, a histological analysis was performed. Results: A higher temperature variation was observed comparing the pilot study in vitro with respect to the experimental one in vivo. Microscopically, an increase of collagen fibers and blood supply and decreased adipose tissue was observed after cryofrequency application. Conclusion: With the bipolar cryofrequency, no reduction of adipose tissue was observed, but regarding the connective tissue, extensive areas of collagen deposition were observed, as well as a great amount of new-formed collagen fibers.

Donor Cell Fate in Particulated Juvenile Allograft Cartilage for the Repair of Articular Cartilage Defects

Background: Particulated juvenile allograft cartilage (PJAC) has demonstrated good clinical efficacy in repairing articular cartilage defects, but the related repair mechanism after transplant and the biological characteristics of the transplanted cells are still unclear. Purpose: To study the efficacy of PJAC in repairing full-thickness cartilage defects and the specific fate of donor cells to provide experimental evidence for its clinical application. Study Design: Controlled laboratory study. Methods: Twenty female Guizhou minipigs were randomly divided into an experimental group and a control group. An 8-mm cylindrical full-thickness cartilage defect was created in the femoral trochlea of 1 knee in all minipigs. The experimental group received transplant of PJAC from 5 male juvenile Guizhou minipigs (PJAC group; n = 10) and the control group received autologous cartilage chips (ACC group; n = 10). Follow-up assessments were conducted at 1 month and 3 months to track the transplanted cells by the male-specific sex-determining region Y-linked (SRY) gene; tissue sections were hybridized in situ, and O’Driscoll histological scoring was performed according to hematoxylin and eosin staining, safranin O and fast green staining, and toluidine blue O staining, as well as immunohistochemical evaluation of aggrecan and Sry-type HMG-box 9 (SOX9). Results: All 20 Guizhou minipigs were followed; no infection or incision healing disorder occurred after the operation. By SRY in situ hybridization, the SRY signal of the transplanted cells was positive in the repaired tissue of the defect, and the SRY positive signal could still be detected in repaired tissue at 3 months postoperatively. The average number of positive cells was 68.6 ± 11.91 at 1 month and 32.6 ± 3.03 at 3 months (confocal microscope: ×400), and the difference was statistically significant. The O’Driscoll histological scores were 14 ± 0.71 in the ACC group and 9.8 ± 0.84 in the PJAC group at 1 month, and 18 ± 1.20 in the ACC group and 17.4 ± 1.14 in the PJAC group at 3 months. The scores were statistically significant between the ACC group and PJAC group at 1 month. The positive rates of SOX9 in the PJAC and ACC groups at 1 month were 67.6% ± 3.78% and 63.4% ± 5.30%, respectively, and the difference was not statistically significant (P > .05). The positive rates of SOX9 in the PJAC and ACC groups at 3 months were 68.8% ± 2.69% and 17.1% ± 1.26%, respectively, and the difference was statistically significant (P < .05). The positive rates of aggrecan in the PJAC and ACC groups at 1 month were 40.5% ± 2.78% and 42.4% ± 0.54% respectively, and the difference was not statistically significant (P > .05). The positive rates of aggrecan in the PJAC and ACC groups at 3 months were 40.8% ± 1.50% and 30.1% ± 2.44%, respectively, and the difference was not statistically significant (P > .05). Conclusion: An animal model was established with Guizhou minipigs, and the cartilage defect was repaired with PJAC from male minipigs. The SRY gene positive signal could be detected from the repaired tissue by in situ hybridization, indicating that the transplanted cells survived at least 3 months. The key genes of cartilage formation, SOX9 and aggrecan, were expressed at 1 month and 3 months, and SOX9 expression was stronger in the PJAC group than the ACC group at 3 months. Clinical Relevance: This study suggests that it is feasible to study the biological characteristics of transplanted cells in the cartilage region by the sex-determining gene.

The experimental study of shunt-decompression arterialized vein flap

BackgroundArterialized vein flap is a kind of unphysiological flap. Unphysiological reconstruction of blood circulation leads to higher load than that supported by physiological flap and is the culprit of flap swelling, blood stasis, skin blistering, and necrosis after flap grafting. To resolve the multiple disadvantages of traditional flap grafting, by introducing the principles of fluid mechanics, shunt-decompression surgery is prepared to decline the circulation preload and improve the prognosis of arterialized vein flap grafting.MethodsBy introducing the principles of fluid mechanics, we established the model of shunt-decompression arterialized vein flap, which satisfied the common properties of general fluid that the interface pressure between object and fluid is reduced when the velocity of fluid is increased and vice versa—the effect of Bernoulli. Under this rule, we anastomose the arterialized vein to the branch of main artery of recipient region or make end-to-side anastomosis, which can maintain the blood flow of main artery, decrease the perfusion of flap, and preserve the decompressive effect of main artery to branches. From March, 2016 to September, 2016, we performed animal experiments on ten male bama mini pigs with average weight of 28 ± 2.35 kg. Superior epigastric artery of pig was used for feeding artery to arterialize the superficial epigastric veins. The total area of flap is 8 cm × 6 cm. End-to-side anastomosis and end-to-end anastomosis were established in experimental group and control group, respectively. Doppler speckle perfusion imaging apparatus was used to monitor the alterations of flap perfusion, blood flow of flap, tissue swelling and survival of flaps.ResultsThe average flap perfusion (PU) at 1 week after surgery is 83.62 ± 3.14 in experimental group and 98.14 ± 6.54 in control group, respectively (P < 0.05), indicating the significant reduction of flap blood perfusion in experimental group as compared with control group. As to the survival of flaps, 7 flaps completely survived, 3 showed partial necrosis, and no one was found as complete necrosis in experimental group, while only 3 flaps survived, and 4 flaps and 3 flaps showed partial necrosis and complete necrosis in control group, respectively (P < 0.05).ConclusionBased on the physiological features of arterialized vein flap and its problems in clinical application, we improved the anastomosis strategy of flap grafting and obtained excellent experimental outcomes, which provides an insight for the clinical application of arterialized vein flaps.

Toxicological profile of IQG-607 after single and repeated oral administration in minipigs: An essential step towards phase I clinical trial

IQG-607 is an anti-tuberculosis drug candidate, with a promising safety and efficacy profile in models of tuberculosis infection both in vitro and in vivo. Here, we evaluated the safety and the possible toxic effects of IQG-607 after acute and 90-day repeated administrations in minipigs. Single oral administration of IQG-607 (220 mg/kg) to female and male minipigs did not result in any morbidity or mortality. No gross lesions were observed in the minipigs at necropsy. Repeated administration of IQG 607 (65, 30, or 15 mg/kg), given orally, for 90 days, in both male and female animals did not cause any mortality and no significant body mass alteration. Diarrhea and alopecia were the clinical signs observed in animals dosed with IQG-607 for 90 days. Long-term treatment with IQG-607 did not induce evident alterations of blood cell counts or any hematological parameters. Importantly, the repeated schedule of administration of IQG-607 resulted in increased cholesterol levels, increased glucose levels, decrease in the globulin levels, and increased creatinine levels over the time. Most necropsy and histopathological alterations of the organs from IQG-607-treated groups were also observed for the untreated group. In addition, pharmacokinetic parameters were evaluated. IQG-607 represents a potential candidate molecule for anti-tuberculosis drug development programs. Its promising in vivo activity and mild to moderate toxic events detected in this study suggest that IQG-607 represents a candidate for clinical development.

Effect of time and temperature on anticoagulant-dependent pseudothrombocytopenia in Göttingen minipigs.

A marked decrease in thrombocyte count was observed between subsequent measurements of the same EDTA blood sample in several minipigs, but little information was available explaining this finding. The objective was to evaluate the impact of several preanalytic variables on thrombocyte counts in minipigs, in order to improve understanding of the invitro thrombocyte decrease observed. Hematology blood samples from male and female Göttingen minipigs were collected using EDTA or citrate as an anticoagulant. Samples were stored under different conditions (room temperature, 4°C, or 37-38°C) and were analyzed approximately 0.5 to oneh, 3.5-4h, 7-7.5h, and 28-29h after collection. In EDTA blood samples from male minipigs stored at room temperature, there was a progressive thrombocyte decrease over time up to -71% after 29h, caused by invitro aggregation. In females, no consistent change was seen up to 7.5h, but there was a decrease up to -47% after 29h. Thrombocyte count was most stable during storage at 4°C. No consistent marked decrease in thrombocyte counts was seen for citrated blood at room temperature, although such a decrease was present in a few individual animals. Study results provide evidence for an anticoagulant-dependent pseudothrombocytopenia in minipigs progressing over time and depending on the storage temperature of the blood sample. It is therefore recommended to perform thrombocyte counts as soon as possible after blood collection, and in case of low counts, investigate for the presence of artifactual platelet clumping.

A safety evaluation of profound hypothermia-induced suspended animation for delayed resuscitation at 90 or 120\xa0min

BackgroundThe successful treatment of military combat casualties with penetrating injuries is significantly dependent on the time needed to get the patient to an adequate treatment facility. Profound hypothermia-induced suspended animation for delayed resuscitation (SADR) is a novel approach for inducing cardiac arrest and buying additional time for such injuries. However, the time used to safely administer circulatory arrest (CA) is controversial. The goal of this study was to evaluate the safety of hypothermia-induced SADR over 90 and 120 min time intervals.MethodsSixteen male BAMA minipigs were randomized into two groups: CA90 group (90 min, n = 8) and CA120 group (120 min, n = 8). Cannulation of the right common carotid arteries and internal jugular veins was performed to establish cardiopulmonary bypass for each animal. Through the perfusion of cold organ preservation solution (OPS), cardioplegia and profound hypothermia (15 °C) were induced. After CA, cardiopumonary bypass (CPB) was restarted, and the animals were gradually re-warmed and resuscitated. The animals were assisted with ventilators until spontaneous breathing was achieved. The index of hemodynamic perioperative serum chemistry values [alanine transaminase (ALT), aspartate aminotransferase (AST), creatinine (CR), lactic dehydrogenase (LDH) and troponin T (TnT)] and survival were observed from pre-operation to 7 days post-operation.ResultsFifteen animals were enrolled in the experiment, while 1 animal in CA120 group died from surgical error. All 8 animals in CA90 group recovered, with only 1 animal displaying mild disability. However, in CA120 group, only 2 animals survived with severe disability, and the other 5 animals died after 2 days post-operation. In CA90 group, the perioperative serum chemistry values increased at 1 day post-operation (ALT 84.43 ± 18.65 U/L; AST 88.99 ± 23.19 U/L; Cr 87.90 ± 24.49 μmol/L; LDH 1894.13 ± 322.26 U/L; TnT 0.849 ± 0.135 ng/ml) but decreased to normal or almost normal levels at 7 days post-operation (ALT 52.48 ± 9.04 U/L; AST 75.23 ± 21.46 U/L; Cr 82.69 ± 18.41 μmol/L; LDH 944.67 ± 834.32 U/L; TnT 0.336 ± 0.076 ng/ml).ConclusionsProfound hypothermia-induced SADR is an effective method for inducing cardiac arrest. Our results indicate that inducing CA for 90 min (at 15 °C) is safer than doing so for 120 min. Our results indicate that 120 min of CA at 15 °C is dangerous and can result in high mortality and severe neurological complications. Further experimentation is needed to determine whether 120 min of CA at temperatures lower than 15 °C can lead to safe recovery.

Different Patterns of Cartilage Mineralization Analyzed by Comparison of Human, Porcine, and Bovine Laryngeal Cartilages

Laryngeal cartilages undergo a slow ossification process during aging, making them an excellent model for studying cartilage mineralization and ossification processes. Pig laryngeal cartilages are similar to their human counterparts in shape and size, also undergo mineralization, facilitating the study of cartilage mineralization. We investigated the processes of cartilage mineralization and ossification and compared these with the known processes in growth plates. Thyroid cartilages from glutaraldehyde-perfused male minipigs and from domestic pigs were used for X-ray, light microscopic, and transmission electron microscopic analyses. We applied different fixation and postfixation solutions to preserve cell shape, proteoglycans, and membranes. In contrast to the ossifying human thyroid cartilage, predominantly cartilage mineralization was observed in minipig and domestic pig thyroid cartilages. The same subset of chondrocytes responsible for growth plate mineralization is also present in thyroid cartilage mineralization. Besides mineralization mediated by matrix vesicles, a second pattern of cartilage mineralization was observed in thyroid cartilage only. Here, the formation and growth of crystals were closely related to collagen fibrils, which served as guide rails for the expansion of mineralization. It is hypothesized that the second pattern of cartilage mineralization may be similar to a maturation of mineralized cartilage after initial matrix vesicles-mediated cartilage mineralization.