Fresh Pig Research Articles

Ablation efficiency and laser safety of a novel superpulsed thulium fiber laser: a in vitro study.

To assess the ablation efficiency of the Superpulsed Thulium Fiber Laser (SP-TFL) and investigate the thermal effects of SP-TFL. A SP-TFLwas employed to evaluate ablation efficiency. Fresh ex-vivo pig kidneys and ureters were utilized to evaluate the renal pelvis and ureter temperature changes, different irrigation rates(0, 15, 38mL/min) and a long pulse width were used. The research indicated that as laser output power increased, ablation rates significantly increased. Ablation rates(mg/min) were higher and the energy per ablated mass(J/mg) was lower at lower frequencies(10-50Hz). Under the same frequency and single pulse energy, super short and short pulse widths demonstrated higher ablation rates at higher frequencies (exceeding 100Hz). The temperature of the renal pelvis and ureter decreased with increasing irrigation rates. In the renal pelvis, without irrigation, the temperature quickly reached the critical threshold of 43℃. The irrigation rate was 15ml/min and power was no more than 18W, the renal pelvis temperature did not reach 43℃. When the irrigation rate were 38ml/min, the temperature did not risen to 43℃. In the ureter, without irrigation, the temperature also quickly reached 43℃. The temperature reached 43℃ when the power exceeded to12W with an irrigation rate of 15ml/min. With an irrigation rate of 38ml/min, the temperature reached 43℃ at a laser power of 30W. The SP-TFL demonstrated promising ablation effectiveness especially for lower frequencies and super short and short pulse widths model. Proper irrigation rates, single pulse energy, frequency and pulse width are crucial during lithotripsy.

Methanization Test of Water Hyacinth and Azolla in Co-digestion and Fertilizing Value of Digestates in Benin (West Africa)

Faced with the need for an alternative energy source following the extreme pressure exerted on woody resources accompanied by the increase of aquatic pests which invade water resources, the construction of mini reactors producing clean energy, biogas based on these invasive plants becomes a challenge. This investigation aims to assess the methane production potential of water hyacinth and Azolla in co-digestion and the fertilizing quality of the digestates obtained. A bio methanization test based on various combinations of organic substrates composed of water hyacinth and Azolla alone or in co-digestion under laboratory conditions at mesophilic temperature and neutral pH after 27 days was carried out. The source of enrichment in anaerobic microorganisms for fermentation processes in micro bioreactors consists of fresh pig manure. It appears that the combination of organic substrates including 75% of water hyacinth generated the maximum quantity of methane which is 1234 liters for one ton of organic substrates. This methane production is 1.93 times greater than that of the bioreactor containing water hyacinth alone, 1.90 times that containing azolla, 1.5 times that containing 25% water hyacinth +75% azolla then 3.04 times that containing the bioreactor composed of a high proportion of crushed Azolla filiculoides. The digestates are rich in N, P, K, Ca and Mg and had an amending power according to the NFU 44051 standard. For the construction of bioreactors with aquatic pests for the benefit of communities, co-digestion with a combination of substrates with a high proportion of water hyacinth is suggested.

Characterization of the in vitro penetration and first-pass metabolism of genistein and daidzein using human and pig skin explants and Phenion full-thickness skin models.

OECD test guideline compliant skin penetration studies, which also comply with the SCCS basic criteria, are lacking for genistein and daidzein. Therefore, we have measured their penetration and metabolism using ex vivo explants of fresh (i.e., metabolically viable) pig skin, fresh and frozen human skin, and Phenion full-thickness (FT) models. Preliminary studies using fresh pig skin helped to define the optimal experimental conditions. The dermal absorption of 10nmoles/cm2 genistein and daidzein in ethanol was comparable in all four models. A first-pass metabolism in skin to glucuronide and sulfate metabolites was demonstrated for both chemicals in all models except frozen human skin. The main difference between fresh skin models was the overall extent of metabolism and the relative ratio of each metabolite, for example, much lower sulfate conjugates were formed in pig skin incubations. The extent of parent chemical metabolized and the contribution of the glucuronide pathway were relatively lower in PhenionFT models than in fresh human skin, possibly due to a higher penetration rate in this model and differences in the expression of functional metabolizing enzymes. When metabolism in human skin was abolished by freezing, more radiolabelled chemical remained in the skin tissue but the overall dermal absorption was unchanged. In conclusion, this initial characterization study showed that all models tested indicated that genistein and daidzein extensively penetrated the skin when applied to skin in ethanol. All fresh skin models produced the same metabolites, with the known species difference in the sulfation pathway demonstrated in pig skin.

Effect of vehicle on the in vitro penetration and metabolism of genistein and daidzein in ex vivo skin explants and the Phenion full-thickness skin model.

In a read-across assessment of the safety of genistein and daidzein in cosmetic products, additional information was required to account for differences in their systemic exposure after topical application in a typical body lotion formulation. Therefore, we measured the penetration and metabolism of two doses (3 and 30 nmoles/cm2) of genistein and daidzein applied in ethanol and in a body formulation to fresh pig skin, fresh and frozen human skin, and PhenionFT models. Both chemicals readily penetrated all skin models when applied in ethanol. The same sulfate and glucuronide metabolites were formed in fresh pig skin, fresh human skin, and PhenionFT models, which also all demonstrated that (a) these pathways could be saturated between 3 and 30 nmoles/cm2 and (b) the extent of metabolism of daidzein was lower than genistein. Although the relative amounts of radiolabeled chemical in human skin and medium compartments were altered by freezing, their overall bioavailability was not affected. The greatest impact on the bioavailability and distribution of both chemicals was observed when they were applied in the formulation. Most of the dose applied in the formulation was retained on the skin surface, especially at 30 nmoles/cm2 (60%-90%), resulting in much lower amounts in the medium and/or skin. In conclusion, all four skin models demonstrated first-pass metabolism of genistein and daidzein and a marked alteration in their disposition by applying them in a body lotion formulation. This supports the use of fresh pig skin and PhenionFT models as alternatives to human skin for investigating skin metabolism and formulation effects for these two chemicals. The results were used to develop the dermal module of a PBPK model and dose setting for organ-on-chip experiments. They could also be used to refine internal exposure estimates in regulatory safety assessments.

Utility of pig head model as an oculoplastic wet lab surgical training tool

ABSTRACT Purpose To assess the utility of pig head model as an oculoplastic surgical training tool. Methods Fresh pig head was availed for surgical workshop for entropion correction, eyelid margin repair, and evisceration with implant for oculoplastic surgery-naïve participants. Skill improvement, surgical understanding, and performance of the participants were evaluated both subjectively and objectively by trained oculoplastic surgeons. Subjective assessment was done by a standardized questionnaire based on Likert scale shared with the participants post training. Objective evaluation was done by the faculty based on a three-point scale and a competency-based surgical assessment rubric. Results There were 18 surgery-naïve participants in the workshop which comprised ophthalmology residents and comprehensive ophthalmologists. About 88.88% of the participants were able to perform the lid margin and sub-tarsal dissection in entropion surgery. While performing lid tear repair, 94.44% were correctly able to identify the grey line and anterior and posterior lamellae. About 83.33% of the participants were able to place an implant in the scleral shell or intraconal space. About 83.33% of the participants noted that texture and tissue maneuvering were similar to the human eye while performing surgical steps. About 94.44% of the participants reported better understanding, development of skill and additional confidence after training. The median score on objective assessment was 3. The performance on real patients resulted in a median score of 4 for entropion correction. Conclusion Porcine orbital dissection is an available, affordable, and useful tool for oculoplastic surgical training. Training on porcine model can improve anatomical understanding, clinical judgement, and surgical efficiency in trainees.

Construction of a novel tissue engineered meniscus scaffold based on low temperature deposition three-dimenisonal printing technology

To investigate the construction of a novel tissue engineered meniscus scaffold based on low temperature deposition three-dimenisonal (3D) printing technology and evaluate its biocompatibility. The fresh pig meniscus was decellularized by improved physicochemical method to obtain decellularized meniscus matrix homogenate. Gross observation, HE staining, and DAPI staining were used to observe the decellularization effect. Toluidine blue staining, safranin O staining, and sirius red staining were used to evaluate the retention of mucopolysaccharide and collagen. Then, the decellularized meniscus matrix bioink was prepared, and the new tissue engineered meniscus scaffold was prepared by low temperature deposition 3D printing technology. Scanning electron microscopy was used to observe the microstructure. After co-culture with adipose-derived stem cells, the cell compatibility of the scaffolds was observed by cell counting kit 8 (CCK-8), and the cell activity and morphology were observed by dead/live cell staining and cytoskeleton staining. The inflammatory cell infiltration and degradation of the scaffolds were evaluated by subcutaneous experiment in rats. The decellularized meniscus matrix homogenate appeared as a transparent gel. DAPI and histological staining showed that the immunogenic nucleic acids were effectively removed and the active components of mucopolysaccharide and collagen were remained. The new tissue engineered meniscus scaffolds was constructed by low temperature deposition 3D printing technology and it had macroporous-microporous microstructures under scanning electron microscopy. CCK-8 test showed that the scaffolds had good cell compatibility. Dead/live cell staining showed that the scaffold could effectively maintain cell viability (>90%). Cytoskeleton staining showed that the scaffolds were benefit for cell adhesion and spreading. After 1 week of subcutaneous implantation of the scaffolds in rats, there was a mild inflammatory response, but no significant inflammatory response was observed after 3 weeks, and the scaffolds gradually degraded. The novel tissue engineered meniscus scaffold constructed by low temperature deposition 3D printing technology has a graded macroporous-microporous microstructure and good cytocompatibility, which is conducive to cell adhesion and growth, laying the foundation for the in vivo research of tissue engineered meniscus scaffolds in the next step.

Percutaneous Fluoroscopic-Guided Celiac Plexus Approach: Results in a Pig Cadaveric Model.

Celiac plexus block (CPB) and neurolysis (CPN) are used for pain management in people suffering from abdominal tumours or chronic pancreatitis. The fluoroscopically guided approach common in human medicine has not been described in veterinary settings. The aim of this study was to describe a fluoroscopic approach to the celiac plexus (CP) in fresh pig cadavers. Twelve animals were included in the procedure. Cadavers were positioned in sternal position and, under fluoroscopic guidance, a Chiba needle was inserted parasagittal at 6 cm from the spinal midline at the level of the last thoracic vertebra. From the left side, the needle was directed medio-ventrally with a 45° angle towards the T15 vertebral body; once the vertebral body was contacted, the needle was advanced 1 cm ventrally towards the midline. Iodinated contrast was injected to confirm the location. Following this, 2 mL of dye (China ink) was injected. A laparotomy was performed, and dyed tissue was dissected and prepared for both histochemical and immunohistochemical techniques. In 10 out of 12 samples submitted for histological evaluation, nervous tissue belonging to CP was observed. Fluoroscopy guidance allows for feasible access to the CP in swine cadavers in this study. Further studies are warranted to determine the efficacy of this technique in swine and other veterinary species.

Technological and Physical-Chemical Evaluation of Cotton Gauzes Impregnated with Semisolid Preparations for Wound Healing.

Chronic wounds are marked by an extended healing period during which damaged tissues fail to undergo orderly and timely repair. Examples of chronic wounds encompass venous ulcers, pressure ulcers, and diabetic foot ulcers. The process of wound healing is complex and dynamic, relying on the interplay and response among various cells and mediators. In this study, four marketed wound dressing products based on cotton gauzes impregnated with different semisolid products (namely Betadine® 10%, Connettivina® Bio Plus Fitostimoline® Plus, and Non-Ad® gauzes) have been characterized for their physicochemical properties and ex vivo behaviors. More in detail, the pH and rheological features of semisolid formulations impregnating the gauzes were analyzed along with their ability to adhere to the gauzes. The most promising ones were selected and compared in ex vivo experiments on fresh pig skin. The pH measurements showed an acidic environment for all the tested solutions, albeit with variations in mean values, ranging from 2.66 to 4.50. The outcomes of rheological studies demonstrated that all the semisolid preparations impregnating the gauzes exhibited a pseudoplastic behavior, with significant differences in the pseudoplasticity index across the preparations, which is likely to influence their ability to adhere to the gauze. A rheological study in oscillatory mode revealed rheological behavior typical of a viscous solution only for the cream impregnating non-paraffin gauzes. The other products exhibited rheological behavior typical of a weak gel, which is expected to be advantageous as regards the capability of the semisolid preparation to create and maintain the space within the wound and to provide protection to the injured tissue. Results of ex vivo experiments demonstrated that Fitostimoline® Plus was more effective than Connettivina® Bio Plus in promoting both skin hydration and energy.

Effect of boiled-water-cooking time on quality and characteristic of flavor components in pig large intestines

Fresh pig large intestines have a heavy initial off-flavor and a strong pungent smell that may cause discomfort to the consumer. To examine how boiled-water cooking of the pig large intestines affects the quality characteristics and flavor profiles, changes in shear force, cooking loss, volatile flavor compounds, and other physical and chemical indexes were measured in pig large defatted intestines using gas chromatography-odor-mass spectrometry detector (GC-O-MS), and electronic nose (E-nose) and texture analyzer. The results showed that indole, 3-methylindole, and 4-methylphenol were the characteristic volatile substances that caused visceral off-odor to the pig large intestines. After boiled-water-cooking, the content of acids decreased, while the aldehydes increased. Group B20 boiled for 20 min showed the highest volatile substance content in pig large intestines. However, the contents of the off-odor components 4-methylphenol, indole, and 3-methylindole in the samples decreased by 56.5%, 45.5%, and 20.4%, respectively, after continuous boiling for 10 min. The odor of the late stage samples (mainly after B20) was significantly different from the control group (R0) and those of the early stage of boiling (B0, B5). As cooking time was increased, the texture of intestines became tender, the shear force decreased, and the fat percentage initially decreased before stabilizing. This study provides a theoretical support for the quality change of pig large intestines during heating.

Feasibility of frozen soft tissues to simulate fresh soft tissue conditions in cone beam CT scans.

To evaluate the feasibility of frozen soft tissues in simulating fresh soft tissues of pig mandibles using cone beam CT (CBCT). Two fresh pig mandibles with soft tissues containing 2 tubes filled with a radiopaque homogeneous solution were scanned using 4 CBCT units and 2 field-of-view (FOV) sizes each. The pig mandibles were deep-frozen and scanned again. Three cross-sections were exported from each CBCT volume and grouped into pairs, with one cross-section representing a fresh and one a frozen mandible. Three radiologists compared the pairs and attributed a score to assess the relative image quality using a 5-point scale. Mean grey values and standard deviation were obtained from homogeneous areas in the tubes, compared using the Wilcoxon matched-pair signed-rank test and subjected to Pearson correlation analysis between fresh and frozen physical states (α = .05). Subjective evaluation revealed similarity of the CBCT image quality between fresh and frozen states. The distribution of mean grey values was similar between fresh and frozen states. Mean grey values of the frozen state in the small FOV were significantly greater than those of the fresh state (P = .037), and noise values of the frozen state in the large FOV were significantly greater than those of the fresh state (P = 0.007). Both mean grey values and noise exhibited significant and positive correlations between fresh and frozen states (P < 0.01). The freezing of pig mandibles with soft tissues may serve as a method to prolong their usability and working time when CBCT imaging is planned.

The effects of exogenous substances on the color of heated bones.

Burned bone coloration has been used for decades to help in the bioanthropological analysis of burned human bones. However, there is a variety of factors that can interfere with the coloration manifested by bones exposed to heat, resulting in colors that differ from the usual black to white gradient. In this study, we evaluated possible causes of unusual coloration changes and hues in burned bone. For that purpose, defleshed fresh pig (Sus scrofa) ribs as well as fresh and dry human clavicles were burned at four different temperatures (500, 700, 900 and 1100°C) in contact with different materials (CaO, Zn, Fe, Cu, Mn, and polyester cloth). Observable color changes were assessed through naked eye observation and description, Munsell color charts, and reflectance spectrophotometry. Additionally, chemical changes in bone were assessed using Fourier-transform infrared spectroscopy in attenuated total reflectance (FTIR-ATR) and x-ray fluorescence (XRF). Our results showed that some materials did affect usual burned bone coloration (Fe, Mn, Cu, Zn) and correspondent FTIR-ATR and XRF spectra. As for other materials, although no effect on visual bone coloration was observed, they still affected FTIR-ATR and XRF spectra (CaO and cloth). This study can contribute to the anthropological analysis of burned human remains, providing some answers to what can cause unusual types of heat-induced colorations.

Quantification of smooth muscle in human airways by polarization-sensitive optical coherence tomography requires correction for perichondrium.

Quantifying airway smooth muscle (ASM) in patients with asthma raises the possibility of improved and personalized disease management. Endobronchial polarization-sensitive optical coherence tomography (PS-OCT) is a promising quantitative imaging approach that is in the early stages of clinical translation. To date, only animal tissues have been used to assess the accuracy of PS-OCT to quantify absolute (rather than relative) ASM in cross sections with directly matched histological cross sections as validation. We report the use of whole fresh human and pig airways to perform a detailed side-by-side qualitative and quantitative validation of PS-OCT against gold-standard histology. We matched and quantified 120 sections from five human and seven pig (small and large) airways and linked PS-OCT signatures of ASM to the tissue structural appearance in histology. Notably, we found that human cartilage perichondrium can share with ASM the properties of birefringence and circumferential alignment of fibers, making it a significant confounder for ASM detection. Measurements not corrected for perichondrium overestimated ASM content several-fold (P < 0.001, paired t test). After careful exclusion of perichondrium, we found a strong positive correlation (r = 0.96, P < 0.00001) of ASM area measured by PS-OCT and histology, supporting the method's application in human subjects. Matching human histology further indicated that PS-OCT allows conclusions on the intralayer composition and in turn potential contractile capacity of ASM bands. Together these results form a reliable basis for future clinical studies.NEW & NOTEWORTHY Polarization-sensitive optical coherence tomography (PS-OCT) may facilitate in vivo measurement of airway smooth muscle (ASM). We present a quantitative validation correlating absolute ASM area from PS-OCT to directly matched histological cross sections using human tissue. A major confounder for ASM quantification was observed and resolved: fibrous perichondrium surrounding hyaline cartilage in human airways presents a PS-OCT signature similar to ASM for birefringence and optic axis orientation. Findings impact the development of automated methods for ASM segmentation.

Animal study: Basic mechanism of vocal cord paralysis caused by button battery ingestion in children

PurposeVocal cord paralysis has been reported as a common complication of button battery (BB) ingestion, and there is a need to confirm the mechanism of vocal cord paralysis for the development of a standardized treatment. MethodsA new CR2032 BB and artificial saliva were placed in a fresh pig esophagus with the recurrent laryngeal nerve (RLN); the negative electrode faced the nerve in the experimental group, while the positive electrode faced the nerve in the control group. The pH values of the intra- and extraesophageal walls were measured simultaneously. Pathological examination was performed after the esophagus and nerves were damaged. ResultsAfter BB ingestion, the pH near the intraesophageal negative electrode increased rapidly, reaching 11.5 at 30 min and over 14 at 6 h, while the extraesophageal pH did not change at 1 h and began to accelerate after 2 h, reaching 10 at 6 h. After 6 h of exposure, the pathological section showed that the structure of the mucosa, submucosa, and muscle layer were destroyed; chromatin in the nucleus faded, and part of the nerve bundle in the adventitia had liquefaction necrosis. ConclusionThe basic mechanism of vocal cord paralysis caused by BB ingestion is that the OH− generated by the electrolytic reaction of the negative electrode penetrates the esophageal wall and corrodes the RLN, which may be the cause of vocal cord paralysis caused by BB ingestion without esophageal perforation.

The alteration of the structure and macroscopic mechanical response of porcine patellar tendon by elastase digestion.

Background: The treatment of patellar tendon injury has always been an unsolved problem, and mechanical characterization is very important for its repair and reconstruction. Elastin is a contributor to mechanics, but it is not clear how it affects the elasticity, viscoelastic properties, and structure of patellar tendon. Methods: The patellar tendons from six fresh adult experimental pigs were used in this study and they were made into 77 samples. The patellar tendon was specifically degraded by elastase, and the regional mechanical response and structural changes were investigated by: (1) Based on the previous study of elastase treatment conditions, the biochemical quantification of collagen, glycosaminoglycan and total protein was carried out; (2) The patellar tendon was divided into the proximal, central, and distal regions, and then the axial tensile test and stress relaxation test were performed before and after phosphate-buffered saline (PBS) or elastase treatment; (3) The dynamic constitutive model was established by the obtained mechanical data; (4) The structural relationship between elastin and collagen fibers was analyzed by two-photon microscopy and histology. Results: There was no statistical difference in mechanics between patellar tendon regions. Compared with those before elastase treatment, the low tensile modulus decreased by 75%-80%, the high tensile modulus decreased by 38%-47%, and the transition strain was prolonged after treatment. For viscoelastic behavior, the stress relaxation increased, the initial slope increased by 55%, the saturation slope increased by 44%, and the transition time increased by 25% after enzyme treatment. Elastin degradation made the collagen fibers of patellar tendon become disordered and looser, and the fiber wavelength increased significantly. Conclusion: The results of this study show that elastin plays an important role in the mechanical properties and fiber structure stability of patellar tendon, which supplements the structure-function relationship information of patellar tendon. The established constitutive model is of great significance to the prediction, repair and replacement of patellar tendon injury. In addition, human patellar tendon has a higher elastin content, so the results of this study can provide supporting information on the natural properties of tendon elastin degradation and guide the development of artificial patellar tendon biomaterials.

Effect of moisture content on larval gut microbiome and the conversion of pig manure by black soldier fly

The study investigated the influence of varied moisture levels in pig manure on the gut microbiome of black soldier fly larvae (BSFL) and their waste conversion efficiency. This encompassed alterations in nutrient components of both BSFL and pig manure, diversity and characterization of the BSFL gut microbiota, and the reciprocal effects between the BSFL gut microbiota and their growth performance and nutrient composition. Additionally, the investigation delved into the changes in the bacterial community and the presence of potential pathogenic bacteria in pig manure. An initial mixture of fresh pig manure and wheat bran was prepared with a 60 % moisture content (Group A). Distilled water was subsequently added to adjust the moisture levels, resulting in mixtures with 65 % (Group B), 70 % (Group C), and 75 % (Group D) moisture content. Each group underwent BSFL digestion over ten days. Groups C (3.87 ± 0.05 mg/worm) and D (3.97 ± 0.08 mg/worm) showed significantly higher bioconversion efficiencies and enhanced BSFL growth compared to Groups A (2.66 ± 0.21 mg/worm) and B (3.09 ± 0.09 mg/worm) (P < 0.05). A 75 % moisture level was identified as ideal, positively influencing fecal conversion efficiency (FCE) (9.57 ± 0.14 %), crude fat intake (8.92 ± 0.56 %), protein (46.60 ± 0.54 %), and total phosphorus (1.37 ± 0.08 %) from pig manure, and subsequent nutrient accumulation in BSFLs. A decline in larval crude ash content indicated higher organic matter and an increased pig manure conversion rate with elevated moisture. High-throughput sequencing and diversity analyses confirmed different moisture contents influenced the BSFL gut microbiota. Bacteroidetes (32.7–62.0 %), Proteobacteria (6.8–29.3 %), Firmicutes (5.8–23.4 %), and Actinobacteria (1.9–29.0 %) were predominant phyla. A 75 % moisture content significantly impacted the BSFL biomass conversion and growth performance. Additionally, Larval feces met non-hazardous fertilizer standards, according to NY-525 (2012).

Absence of Anaphylactic Reactions to Injection of Hemoglobin Vesicles (Artificial Red Cells) to Rodents.

The safety and efficacy of hemoglobin vesicles (HbVs) as artificial oxygen carriers encapsulating a purified and concentrated Hb solution in liposomes have been studied extensively. The HbV surface, modified with PEG by incorporating a PEG-conjugated phospholipid, is beneficial for storage and biocompatibility. However, it might be possible that interaction of PEG and the pre-existing anti-PEG antibody in the bloodstream causes acute adverse reaction. This study used two sets of experiments with rats and guinea pigs to ascertain whether the anti-PEG antibody generated by the PEG-modified HbV injection can induce anaphylactic reactions. SD rats received repeated intravenous injection of HbV at a dose rate of 16 or 32 mL/kg three times. Not anti-PEG IgG but anti-PEG IgM was detected. Nevertheless, no anaphylactic reaction occurred. Guinea pigs were used to study the presence of active systemic anaphylaxis further after injections of the PEG-modified liposomes used for HbV. The animals were sensitized by three repeated subcutaneous injections of PEG-modified liposomes (PEG-liposome) along with adjuvant at 1 week intervals. For comparison, unmodified liposomes (liposome) and 10 times excessively PEG-modified liposomes with ionizable lipid (10PEG-DODAP-liposome) were used. Inclusion of PEG modification induced not only anti-PEG IgM but also anti-PEG IgG. Three weeks after the final injection, intravenous injection of both PEG-liposome and liposome (1 mL/kg) induced no anaphylactic reaction. However, the injection of 10PEG-DODAP-liposome showed one lethal anaphylaxis case and one mild anaphylaxis case. Antisera obtained from the animal sensitized as described above were inoculated (0.05 mL) intradermally into fresh guinea pigs. The presence of passive cutaneous anaphylaxis was evaluated after intravenous injections (1 mL/kg) of three liposomes with Evans blue. No dye leakage was detected at any inoculated skin point for PEG-liposome or liposome, but a slight leakage was detected in one inoculated skin point for 10PEG-DODAP-liposome. These results indicate the absence of acute allergic reactions at repeated injections of HbVs despite the anti-PEG antibody induction. Not all the PEG-modified liposomes show anaphylaxis, and it may depend on the amount of PEGylated phospholipid and lipid composition of PEG-modified liposomes.

ASSESSMENT OF THE CONTRIBUTION OF WILDLIFE AND DOMESTIC PIGS IN HEPATITIS E VIRUS TRANSMISSION AND ZOONOTIC POTENTIAL IN EASTERN ROMANIA

Hepatitis E virus (HEV) has been confirmed within the landscape of the European food industry, representing a significant factor in the dissemination of HEV among European citizens. Food-borne transmission of HEV appears to be a major route in Europe, pigs and wild boars being the main source. The results of this study highlight an overall HEV seroprevalence of 12.8% (95%CI: 7.95-17.75) in wild boars and detection of HEV RNA in all three fresh pig liver batches sampled from a slaughterhouse in Iași County. Given the prevalent dietary preferences in Romania, pork stands out as a highly favored food choice among the populace. However, the popularity of pork also raises concerns, as there exists the occasional risk of contamination with HEV, presenting a potential threat to consumer health. Ongoing surveillance, regulatory measures, and public awareness initiatives collectively may represent a comprehensive strategy to protect the consumers and ensure the safety of pork products in the market.

IN VITRO EVALUATION OF A NOVEL AUTOMATIC INTRAOPERATIVE BLOOD LOSS MONITOR.

Introduction: Accurate and real-time monitoring of surgical blood loss is essential for ensuring intraoperative safety. However, there is currently no standard way to assess the amount of blood lost in patients during surgery. This study aims to evaluate the accuracy and precision of a new automatic intraoperative blood loss monitor, which can measure both free blood volume and blood content in sponges in real time. Methods: The monitor uses an integrated photoelectric probe to gauge hemoglobin levels in both free blood and blood taken from surgical sponges. These data, combined with initial hemoglobin levels, are processed using specific calculations to determine blood volume. We created 127 diverse free blood samples and 160 blood-containing sponge samples by using fresh pig blood and physiological saline. The monitor then measured these samples. We subsequently compared its measurements with actual values acquired through physical measurements, detecting both agreement and measurement errors. Repeated measurements were performed to calculate the coefficient of variation, thereby evaluating the monitor's precision. Results: The estimated blood loss percentage error of the monitor was 5.2% for free blood, -5.7% for small sponge, -6.3% for medium sponge, and -6.6% for large sponge. The coefficient of variation of free blood with different hemoglobin concentrations measured by the monitor was less than 10%. Bland-Altman analysis showed that the limits of agreement between the monitor and the reference method were all within the acceptable clinical range. Conclusion: The new automatic intraoperative blood loss monitor is an accurate and reliable device for monitoring both free blood and surgical sponge blood, and shows high performance under various clinical simulation conditions.

Pig slurry organic matter transformation and methanogenesis at ambient storage temperatures.

Manure management is a significant source of global methane emissions, and there is an increased interest in understanding and predicting emissions. The hydrolysis rate of manure organic matter is critical for understanding and predicting methane emissions. We estimated hydrolysis rate constants of crude protein, fibers, and lipids and used the Arrhenius equation to describe its dependency on temperature. Simultaneously, measurements of methane emission, 13/12 C isotope ratios, and methanogen community were conducted. This was achieved by incubating fresh pig manure without inoculum at 10°C, 15°C, 20°C, and 25°C for 85 days in a lab-scale setup. Hydrolysis of hemicellulose and cellulose increased more with temperature than crude protein, but still, hydrolysis rate of crude protein was highest at all temperatures. Results suggested that crude protein consisted of multiple substrate groups displaying large differences in degradability. Lipids and lignin were not hydrolyzed during incubations. Cumulative methane emissions were 7.13±2.69, 24.6±8.00, 66.7±4.8, and 105.7±7.14 gCH4 kgVS -1 at 10°C, 15°C, 20°C, and 25°C, respectively, and methanogenic community shifted from Methanosphaera toward Methanocorpusculum over time and more quickly at higher temperatures. This study provides important parameter estimates and dependencies on temperature, which is important in mechanistic methane emission models. Further work should focus on characterizing quickly degradable substrate pools in the manure organic matter as they might be the main carbon source of methane emission from manure management.

Investigation of microbial communities across swine slaughter stages and disinfection efficacy assessment in a pig slaughterhouse

The processing environment of pig slaughterhouses is a significant potential source of bacterial contamination in pork products for sale. In this study, we employed 16S rRNA sequencing and diversity analysis to characterize the heterogeneity of microbiota on carcass surfaces and environment of a swine slaughterhouse. Furthermore, we assess variations in microbiota across swine slaughter stages, as well as the effectiveness of disinfection by analysing microbial diversity before and after disinfection. The results indicated that the predominant genus present in all samples were Psychrobacter spp., followed by Acinetobacter spp. The occurrence of cross-contamination within the slaughterhouse is prevalent, particularly during interactions involving fresh pig carcasses, including worker operations, tools, and machinery. Remarkably, trimming emerges as a critical control point and a pivotal factor in cross-contamination. The disinfection procedure were partly effective in reducing of microbial contamination of the environment, significantly reducing bacterial diversity and favoring some genera such as Psychrobacter and Weissella confusa. This study provides a deeper understanding of microbial contamination in abattoirs and emphasizes the importance of disinfection. Moreover, it offers scientific suggestions for implementing effective disinfection.