A survey of the impact of COVID-19 on the management of animal experiments and laboratory animal facilities in Korea

The pandemic has affected the lives of people all over the world. The effects of the pandemic on laboratory animal facilities and their operations through this unusual global event are poorly understood. Here, we have applied a methodological framework of qualitative approach including semi-structured interviews to investigate laboratory animal operations in Korea and how it has shaped the on-going management and laboratory operations of such facilities. A total of fifty-two individuals, including members and administrators of the Institutional Animal Care and Use Committee (IACUC), researchers, and animal facility managers and staff, were surveyed through purposeful sampling. Survey questions explored how the pandemic impacted the IACUC and the functioning of animal facilities, and what steps to take in preparation of a future pandemic-like crisis. Our survey found evidence of an increase in animal experiments in Korea during the pandemic that correlated with increases in research funding during that period, such as for vaccine development. Also, operational challenges due to pandemic-related health issues in personnel were resolved through overtime, rather than by reducing facility operations. Moreover, a refinement of post-approval monitoring (PAM) practices was also discussed by respondents. Taken together, our study offers insights into animal facility operations during the pandemic and outlines recommendations for safeguarding operations in such future scenarios.

Effects of Tetrahydrolipstatin on Glioblastoma in Mice: MRI-Based Morphologic and Texture Analysis Correlated with Histopathology and Immunochemistry Findings-A Pilot Study

BACKGROUND

This study aimed to investigate the effects of tetrahydrolipstatin (orlistat) on heterotopic glioblastoma in mice by applying MRI and correlating the results with histopathology and immunochemistry.

METHODS

Human glioblastoma cells were injected subcutaneously into the groins of immunodeficient mice. After tumor growth of >150 mm3, the animals were assigned into a treatment group (n = 6), which received daily intraperitoneal injections of orlistat, and a control group (n = 7). MRI was performed at the time of randomization and before euthanizing the animals. Tumor volumes were calculated, and signal intensities were analyzed. The internal tumor structure was evaluated visually and with texture analysis. Western blotting and protein expression analysis were performed.

RESULTS

At histology, all tumors showed high mitotic and proliferative activity (Ki67 ≥ 10%). Reduced fatty acid synthetase expression was measured in the orlistat group (p < 0.05). Based on the results of morphologic MRI-based analysis, tumor growth remained concentric in the control group and changed to eccentric in the treatment group (p < 0.05). The largest area under the receiver operating curve of the predictors derived from the texture analysis of T2w images was for wavelet transform parameters WavEnHL_s3 and WavEnLH_s4 at 0.96 and 1.00, respectively.

CONCLUSIONS

Orlistat showed effects on heterotopically implanted glioblastoma multiforme in MRI studies of mice based on morphologic and texture analysis.

Comparison and discussion of behavior and pathology of four kinds of cerebral palsy disease models

Explore the differences in behavioral and pathological manifestations of rat models of cerebral palsy made by different methods and discuss what types of studies these models are suitable for. Behavioral evaluation and pathological section observation were used to observe and evaluate the model. Conclusion: except for the absence of data of bilateral common carotid artery ligation rats, the other three methods could all achieve a successful cerebral palsy disease model for both behavioral and pathological. For researchers, the selection of intraperitoneal infection model in pregnant rats or unilateral ischemia and hypoxia model in infant rats is sufficient to meet the experimental needs, whereas the selection of the combined method for modeling does not show enough advantages, which not only causes the waste of financial and human resources but also increases the possibility of experimental error made by intervention factors.

Is transmucosal healing of an implant as effective as submerged healing when simultaneous guided bone regeneration is performed? A preclinical study

AIM

To investigate whether transmucosal healing is as effective as submerged healing in terms of buccal bone regeneration when guided bone regeneration (GBR) is performed simultaneously with implant placement.

MATERIALS AND METHODS

In six dogs, buccal dehiscence defects were created in the edentulous mandibular ridge, sized 5 × 5 × 3 mm (length × height × depth). In each defect, a bone-level implant was placed, and four experimental groups were randomly assigned as follows: (i) transmucosal healing with GBR (T-GBR), (ii) transmucosal healing without GBR (T-control), (iii) submerged healing with GBR (S-GBR) and (iv) submerged healing without GBR (S-control). Data analyses were based on histological slides 5 months after implant placement.

RESULTS

The T-GBR group showed significant differences compared to the control groups regarding defect height resolution, buccal bone thickness and mineralized tissue area (p < .05), but showed no significant differences when compared with the S-GBR group (p > .05).

CONCLUSIONS

The mode of healing (transmucosal vs. submerged) does not influence bone regeneration at implant sites. The clinician may therefore choose the approach based on further clinical and patient-specific parameters.

Microscopic in-situ analysis of the mucosal healing around implants treated by protease activated receptor 4-agonist peptide or perpendicularly protruded type I collagen in rats

Enhanced mucosal sealing around titanium implants can reduce complications such as peri-implantitis. The present study aims to investigate the mucosal healing at the early stage around the protease activated receptor 4-agonist peptide (PAR4-AP)- or perpendicularly protruded type I collagen (pCol)-treated titanium implants. A total of 72 implants were placed in 36 rats in the study. Following extractions, two tissue-level implants among the following three different surfaces, PAR4-AP-coated (PAR4 group, n = 24), pCol-treated (pCol group, n = 24) and non-treated (control group, n = 24) ones, were placed in the maxillae of each rat based on a split-mouth design. The specimens retrieved at 8 h (n = 8 per group), 3 days (n = 8 per group), and 2 weeks (n = 8 per group), were immunostained and tissue-cleared, and the signals of laminin-5 and collagen fibers were observed under multiphoton microscopy. Statistical analyses were performed using linear mixed model with post hoc tests to compare differences between the groups. While there was no intergroup difference at 8 h, the laminin-5 at 3 days was more abundant near the PAR4-group-surface, and its area was significantly larger in the PAR4 group (0.0204 ± 0.0194 mm2 ) than the control (0.0019 ± 0.0025 mm2 , p = .001) and pCol (0.0023 ± 0.0022 mm2 , p < .001) groups. The pCol group showed a significantly larger area of collagen fibers (0.0230 ± 0.0148 mm2 ) compared to the control (0.0035 ± 0.0051 mm2 , p = .002) and PAR4 (0.0031 ± 0.0057 mm2 , p < .001) groups at 3 days. At 3 days and 2 weeks, the collagen fiber orientation of the pCol group showed a more perpendicular manner compared to the control and PAR4 groups. The signal of basal lamina and collagen fibers were stronger around the PAR4-AP- and pCol-treated titanium surfaces, respectively during the early healing stage. This could have implications for improved mucosal sealing around dental implants, potentially reducing complications such as peri-implantitis.

Vitamin D3 and omega-3 polyunsaturated fatty acids have beneficial effects on fracture union in an experimental rat model

OBJECTIVES

This study aimed to determine the influences of vitamin D3 and omega-3 polyunsaturated fatty acids (PUFAs) on fracture union in rats radiologically, histologically, and biomechanically.

MATERIALS AND METHODS

Forty-eight male Sprague-Dawley rats (mean weight: 435±31.15 g; range, 398 to 510 g) were indiscriminately separated into four groups, with 12 rats in each: Group 1 was the control group, Group 2 received vitamin D3, Group 3 received omega-3 PUFA, and Group 4 received both vitamin D3 and omega-3 PUFA. One day after surgery, only one intramuscular dose of 50,000 IU/kg vitamin D3 was administered to Group 2. From the first postoperative day until sacrification, 300 mg/kg omega-3 PUFA by oral feeding was administered to Group 3. In Group 4, both an intramuscular dose of 50,000 IU/kg vitamin D3 on the initial postoperative day and 300 mg/kg omega-3 PUFA were administered by oral feeding until sacrification. All rats were sacrificed by intracardiac potassium injection at the sixth postoperative week, and radiological, biomechanical, and histological studies were conducted.

RESULTS

According to the radiological scores, the best scores were obtained in Group 4, and callus density and ossification were advanced in Groups 2 and 3 compared to Group 1. There was no statistically significant distinction between Groups 3 and 4, while a significant distinction was found between Group 4 and Groups 1 and 2. Biomechanically, the advanced values were attained in Groups 1 and 3. However, there was no statistically significant distinction among the groups. Histologically, although the advanced scores were attained in Groups 3 and 4, there was no statistically significant distinction among the groups.

CONCLUSION

The use of omega-3 PUFA together with vitamin D3 might have beneficial influences on fracture union. In the future, the combination of omega-3 PUFA and vitamin D3 might be used as an encouraging treatment choice that contributes to fracture healing.

Characteristics, Whole-Genome Sequencing and Pathogenicity Analysis of Escherichia coli from a White Feather Broiler Farm

Avian colibacillosis, caused by avian Escherichia coli (E. coli), has historically been one of the most prevalent infectious diseases in large-scale poultry production, causing growth delays and mortality in chickens, resulting in huge economic losses. In recent years, the widespread use of antibiotics has led to the emergence of multidrug resistance in E. coli as a significant global problem and long-term challenge. Resistant E. coli can be transmitted to humans through animal products or the environment, which presents significant public health concerns and food safety issues. In this study, we analyzed the features of 135 E. coli strains obtained from a white feather broiler farm in Shandong, China, including antimicrobial susceptibility tests, detection of class 1 integrons, drug resistance genes, virulence genes, and phylogenetic subgroups. It is particularly worrying that all 135 E. coli strains were resistant to at least five antibiotic agents, and 100% of them were multidrug-resistant (MDR). Notably, the resistance genes of blaTEM, blaCTX-M, qnrS, aaC4, tetA, and tetB exhibited a high prevalence of carriage among the tested resistance genes. However, mcr-2~mcr-9 were not detected, while the prevalence of mcr-1 was found to be 2.96%. The most common virulence genes detected were EAST1 (14.07%, encoding enterotoxins) and fyuA (14.81%, encoding biofilm formation). Phylogenetic subgroup analysis revealed that E. coli belonging to groups B2 and D, which are commonly associated with high virulence, constituted 2.22% and 11.11%, respectively. The positive rate of class 1 integrons was 31.1%. Whole-genome sequencing (WGS) and animal experiments were performed on a unique isolated strain called 21EC78 with an extremely strong membrane-forming capacity. The WGS results showed that 21EC78 carried 11 drug resistance genes and 16 virulence genes. Animal experiments showed that intraperitoneal injection with 2 × 105 CFU could cause the death of one-day-old SPF chickens in 3 days. However, the mortality of Luhua chickens was comparatively lower than that of SPF chickens. This study reports the isolation of multidrug-resistant E. coli strains in poultry, which may pose a potential threat to human health via the food chain. Furthermore, the findings of this study enhance our comprehension of the frequency and characteristics of multidrug-resistant E. coli in poultry farms, emphasizing the urgent need for improved and effective continuous surveillance to control its dissemination.

Refinement of Animal Experiments: Replacing Traumatic Methods of Laboratory Animal Marking with Non-Invasive Alternatives

Reliable methods for identifying rodents play an important role in ensuring the success of preclinical studies. However, animal identification remains a trivial laboratory routine that is not often discussed, despite the fact that more than 6 million rodents are used in animal studies each year. Currently, there are extensive regulations in place to ensure adequate anesthesia and to reduce animal suffering during experiments. At the same time, not enough attention is paid to the comfort of rodents during routine identification procedures, which can be painful and cause some complications. In order to achieve the highest ethical standards in laboratory research, we must minimize animal discomfort during the identification phase. In this article, we discuss traumatic methods of identification and describe several painless methods for marking in long-term experimental studies. The use of non-traumatic and non-invasive methods requires the renewal of marks as they fade and additional handling of the rodents. Laboratory personnel must be trained in stress-minimizing handling techniques to make mark renewal less stressful.

[Mechanism of Wuling Capsules against hepatic fibrosis based on network pharmacology and animal experiments]

The present study aimed to explore the underlying mechanism of Wuling Capsules in the treatment of hepatic fibrosis(HF) through network pharmacology, molecular docking, and animal experiments. Firstly, the chemical components and targets of Wuling Capsules against HF were searched from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), Traditional Chinese Medicines Integrated Database(TCMID), GeneCards, and literature retrieval. The protein-protein interaction(PPI) network analysis was carried out on the common targets by STRING database and Cytoscape 3.9.1 software, and the core targets were screened, followed by Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses. Enrichment analysis was conducted on the core targets and the "drug-core component-target-pathway-disease" network was further constructed. Subsequently, molecular docking between core components and core targets was conducted using AutoDock Vina software to predict the underlying mechanism of action against HF. Finally, an HF model induced by CCl_4 was constructed in rats, and the general signs and liver tissue morphology were observed. HE and Masson staining were used to analyze the liver tissue sections. The effects of Wuling Capsules on the levels of inflammatory factors, hydroxyproline(HYP) levels, and core targets were analyzed by ELISA, RT-PCR, etc. A total of 445 chemical components of Wuling Capsules were screened, corresponding to 3 882 potential targets, intersecting with 1 240 targets of HF, and 47 core targets such as TNF, IL6, INS, and PIK3CA were screened. GO and KEGG enrichment analysis showed that the core targets mainly affected the process of cell stimulation response and metabolic regulation, involving cancer, PI3K-Akt, MAPK, and other signaling pathways. Molecular docking showed that the core components of Wuling Capsules, such as lucidenic acid K, ganoderic acid B, lucidenic acid N, saikosaponin Q2, and neocryptotanshinone, had high affinities with the core targets, such as TNF, IL6 and PIK3CA. Animal experiments showed that Wuling Capsules could reduce fat vacuole, inflammatory infiltration, and collagen deposition in rat liver, decrease the levels of inflammatory cytokines TNF-α, IL-6, and HYP, and downregulated the expressions of PI3K and Akt mRNA. This study suggests that the anti-HF effect of Wuling Capsules may be achieved by regulating the PI3K-Akt signaling pathway, reducing the levels of TNF-α and IL-6 inflammatory factors, and inhibiting the excessive deposition of collagen.

[Exploring the therapeutic mechanism of Liuwei Suanzao decoction for perimenopausal insomnia based on network pharmacology and animal experiments]

OBJECTIVE

To explore the therapeutic mechanism of Liuwei Suanzao decoction (LWSZD) for perimenopausal insomnia (PI) based on network pharmacology.

METHODS

TCMSP and Batman-TCM databases were searched for the active ingredients and targets of LWSZD and a herb-active ingredient-target network was constructed, and the disease targets were obtained from the OMIM, Genecards and Gene databases.The common targets were imported into STRING database and Cytoscape software to screen the core therapeutic targets, and GO enrichment and KEGG pathway analyses were performed using DAVID database.Molecular docking of the main active ingredients of LWSZD and the core targets was conducted using AutoDock, and the results were verified by observing the therapeutic effects of LWSZD and zolpidem in a rat model of PI induced by bilateral ovariectomy and intraperitoneal p-chlorophenylalanine injection.

RESULTS

A total of 99 active ingredients, 389 drug targets, 187 PI-related targets, and 15 drug-PI common targets were screened.The core active ingredients were armepavine, sanjoinenine and mairin, and the core targets included ESR1, SIRT1, SERPINE1, COMT and CCL2, which were involved in the positive regulation of transcription from RNA polymerase II promoter, signal transduction, response to drug and positive regulation of transcription and in the pathways of dopaminergic synapses, tyrosine metabolism and tryptophan metabolism.Molecular docking results showed that LWSZD had a strong binding with ESR1, SIRT1 and SERPINE1 and was comparable to zolpidem.In the rat models of PI, treatment with LWSZD effectively alleviated the symptoms of insomnia (P<0.01), improved the levels of estrogen and other HPO axis-related hormones (P<0.05), and promoted the mRNA and protein expressions of ESR1 and SIRT1 in the hypothalamus tissues (P<0.01).

CONCLUSION

The active ingredients armepavine, sanjoinenine and mairin in LWSZD may synergistically regulate the expressions of ESR1, SIRT1 and SERPINE1 to improve PI in rats.

Expression of CXCL12-CXCR4/CXCR7 chemokines in splenic fibrosis of cirrhotic spleen and its therapeutic significance

Introduction

To investigate the expression and treatment of chemokine CXCL12 and its receptor CXCR4/CXCR7.

Methods

The liver cirrhosis hypersplenism model of rats was made with CCL4, and then was detected by immunohistochemistry, Western blot and qRT-PCR.

Results

The area of spleen fibrosis in the model group was significantly larger than that in the control group (p < 0.01), and the expression of CXCL12, CXCR4 and CXCR7 in the model group was significantly higher than that in the control group (p < 0.01).

Conclusions

CXCL12-CXCR4/CXCR7 is abnormally high in splenic fibrosis, and blocking its high expression can slow down the occurrence of hypersplenism.

Thiamine for the Treatment of Cardiac Arrest-Induced Neurological Injury: A Randomized, Blinded, Placebo-Controlled Experimental Study

Background Thiamine supplementation has demonstrated protective effects in a mouse model of cardiac arrest. The aim of this study was to investigate the neuroprotective effects of thiamine in a clinically relevant large animal cardiac arrest model. The hypothesis was that thiamine reduces neurological injury evaluated by neuron-specific enolase levels. Methods and Results Pigs underwent myocardial infarction and subsequently 9 minutes of untreated cardiac arrest. Twenty minutes after successful resuscitation, the pigs were randomized to treatment with either thiamine or placebo. All pigs underwent 40 hours of intensive care and were awakened for assessment of functional neurological outcome up until 9 days after cardiac arrest. Nine pigs were included in both groups, with 8 in each group surviving the entire intensive care phase. Mean area under the curve for neuron-specific enolase was similar between groups, with 81.5 μg/L per hour (SD, 20.4) in the thiamine group and 80.5 μg/L per hour (SD, 18.3) in the placebo group, with an absolute difference of 1.0 (95% CI, -57.8 to 59.8; P=0.97). Likewise, there were no absolute difference in neurological deficit score at the end of the protocol (2 [95% CI, -38 to 42]; P=0.93). There was no absolute mean group difference in lactate during the intensive care period (1.1 mmol/L [95% CI, -0.5 to 2.7]; P=0.16). Conclusions In this randomized, blinded, placebo-controlled trial using a pig cardiac arrest model with myocardial infarction and long intensive care and observation for 9 days, thiamine showed no effect in changes to functional neurological outcome or serum levels of neuron-specific enolase. Thiamine treatment had no effect on lactate levels after successful resuscitation.

Modifiers of radiation effects on breast cancer incidence revealed by a reanalysis of archival data of rat experiments

Cancer risk after exposure to ionizing radiation can vary between individuals and populations, but the impact of factors governing those variations is not well understood. We previously conducted a series of carcinogenesis experiments using a rat model of breast cancer, in which 1654 rats born in 2002-2012 were exposed to γ rays at various doses and ages with or without non-radiation factors including high-fat diet, parity and chemical carcinogens. We herein reanalyze the incidence data from these archival experiments to clarify the effect of age at exposure, attained age, radiation dose and non-radiation factors (i.e. fat, parity, chemicals and birth cohorts) on radiation-related mammary cancer incidence. The analysis used excess relative risk (ERR) and excess absolute risk (EAR) models as well as generalized interaction models. Age-at-exposure dependence displayed a peak of susceptibility at puberty in both the ERR and EAR models. Attained age decreased ERR and increased EAR per unit radiation dose. The dose response was concordant with a linear model. Dietary fat exhibited a supra-multiplicative interaction, chemicals represented a multiplicative interaction, and parity and birth cohorts displayed interactions that did not significantly depart from additivity or multiplicativity. Treated as one entity, the four non-radiation factors gave a multiplicative interaction, but separation of the four factors significantly improved the fit of the model. Thus, the present study supports age and dose dependence observed in epidemiology, indicates heterogenous interactions between radiation and various non-radiation factors, and suggests the potential use of more flexible interaction modeling in radiological protection.

Statistical review of animal trials-A guideline

Any experiment involving living organisms requires justification of the need and moral defensibleness of the study. Statistical planning, design, and sample size calculation of the experiment are no less important review criteria than general medical and ethical points to consider. Errors made in the statistical planning and data evaluation phase can have severe consequences on both results and conclusions. They might proliferate and thus impact future trials-an unintended outcome of fundamental research with profound ethical consequences. Unified statistical standards are currently missing for animal review boards in Germany. In order to accompany, we developed a biometric form to be filled and handed in with the proposal at the concerned local authority on animal welfare. It addresses relevant points to consider for biostatistical planning of animal experiments and can help both the applicants and the reviewers in overseeing the entire experiment(s) planned. Furthermore, the form might also aid in meeting the current standards set by the 3+3R's principle of animal experimentation: Replacement, Reduction, Refinement as well as Robustness, Registration, and Reporting. The form has already been in use by the concerned local authority of animal welfare in Berlin, Germany. In addition, we provide reference to our user guide giving more detailed explanation and examples for each section of the biometric form. Unifying the set of biostatistical aspects will help both the applicants and the reviewers to equal standards and increase quality of preclinical research projects, also for translational, multicenter, or international studies.

Influence of loading and grafting on hard- and soft-tissue healing at immediately placed implants: An experimental study in minipigs

AIM

To histologically evaluate the influence of (1) loading and (2) grafting on osseointegration and peri-implant soft-tissue healing at immediately placed, self-cutting progressive tissue-level implants (TLX) in a minipig model.

MATERIALS AND METHODS

TLX implants (n = 56) were immediately placed following the extraction of the mandibular first and second premolars, bilaterally, in a total of n = 14 minipigs. In each animal, the implant sites were allocated to the following four groups: (1) unloaded with simultaneous grafting using a bovine bone mineral; (2) unloaded without grafting; (3) loaded with simultaneous grafting; and (4) loaded without grafting. Histomorphometric assessments at 4 and 12 weeks (n = 7 animals each) included primary (i.e., bone-to-implant contact [BIC]) and secondary outcome measures (e.g., first BIC [fBIC], junctional epithelium length [JE], connective tissue contact length [CTC], biological width [BW = JE + CTC]).

RESULTS

At 4 weeks, mean BIC values ranged from 74.5 ± 11.6% in Group 2 to 83.8 ± 13.3% in Group 1, and, at 12 weeks, from 75.5% ± 7.9% in Group 2 to 79.9 ± 8.6% in Group 1. Multivariate linear mixed regression did not reveal any associations between BIC and implant loading or grafting at 4 and 12 weeks. At 12 weeks, significantly higher fBIC values were noted in Group 2 when compared with Group 1. All groups showed comparable JE, CTC, and BW values.

CONCLUSIONS

Implant loading and grafting had no major effects on osseointegration and peri-implant soft tissue healing at TLX implants.

Plant-based model for the visual evaluation of electroporated area after irreversible electroporation and its comparison to in-vivo animal data

Electroporation (EP) is widely used in medicine, such as cancer treatment, in form of electrochemotherapy or irreversible electroporation (IRE). For EP device testing, living cells or tissue inside a living organism (including animals) are needed. Plant-based models seem to be a promising alternative to substitute animal models in research. The aim of this study is to find a suitable plant-based model for visual evaluation of IRE, and to compare the geometry of electroporated areas with in-vivo animal data.For this purpose, a variety of fruit and vegetables were selected and visually evaluated after 0/1/2/4/6/8/12/16/24 h post-EP. Apple and potato were found to be suitable models as they enabled a visual evaluation of the electroporated area. For these models, the size of the electroporated area was determined after 0/1/2/4/6/8/12/16/24 h. For apples, a well-defined electroporated area was visual within two hours, while in potatoes it reached a plateau after eight hours only. The electroporated area of apple, which showed the fastest visual results was then compared to a retrospectively evaluated swine liver IRE dataset which had been obtained for similar conditions. The electroporated area of the apple and swine liver both showed a spherical geometry of comparable size. For all experiments, the standard protocol for human liver IRE was followed. To conclude, potato and apple were found to be suitable plant-based models for the visual evaluation of electroporated area after irreversible EP, with apple being the best choice for fast visual results. Given the comparable range, the size of the electroporated area of the apple may be promising as a quantitative predictor in animal tissue. Even if plant-based models cannot completely replace animal experiments, they can be used in the early stages of EP device development and testing, decreasing animal experiments to the necessary minimum.

Development of novel biliary metal stent with coil-spring structure and its application in vivo swine biliary stricture model

Background

As of date, endoscopic biliary stenting with plastic stent (PS) and self-expandable metal stent (SEMS) have been widely used for the palliation of biliary tract strictures. However, these two stents have several limitations regarding the management of biliary strictures caused by intrahepatic and hilar cholangiocarcinoma. PS has short patency and also risks bile duct injury and bowel perforation. SEMS is difficult to revise when occluded by tumor overgrowth. To compensate for such shortcomings, we developed a novel biliary metal stent with coil-spring structure. The aim of this study was to investigate the feasibility and efficacy of the novel stent in a swine model.

Methods

The biliary stricture model was prepared in six mini-pigs using endobiliary radiofrequency ablation. Conventional PS (n=2) and novel stents (n=4) were deployed endoscopically. Technical success was defined as successful stent placement and clinical success was defined as >50% reduction of serum bilirubin level. Adverse events, stent migration, and endoscopic removability for one month after stenting were also assessed.

Results

The biliary stricture was successfully created in all animals. The technical success rate was 100 %, and the clinical success rate was 50% in the PS group and 75% in the novel stent group. In the novel stent group, the median pre- and post-treatment serum bilirubin levels were 3.94 and 0.3 mg/dL. Stent migration occurred in two pigs and two stents were removed by endoscopy. There was no stent-related mortality.

Conclusions

The newly designed biliary metal stent was feasible and effective in a swine biliary stricture model. Further studies are needed to verify the usefulness of the novel stent in the management of biliary strictures.

[Role of animal experiment in acupuncture translational medicine]

The basic biological research of acupuncture originates from clinical practice and serves clinical application. It is the fundamental idea of "acupuncture translational medicine". The animal experiment is indispensable in acupuncture translational medicine, which contributes to simplifying the complex factors affecting the clinical efficacy of acupuncture, observing the effect of the nociceptive stimuli and obtaining the invasive and off-body biomarkers. Focusing on animal experiment, the basic biological research can objectively reveal the structure and function of acupoints, obtain the parameters required by different stimulation methods and clarify the material basis which acupuncture works, so as to provide the references and evidences for acupoint combination and the selection of appropriate stimulation in clinical practice, as well as the development of medical instruments and new drugs.

Comparison of the Virulence of Korean African Swine Fever Isolates from Pig Farms during 2019-2021

African swine fever (ASF) was first reported in South Korea in September 2019, and as of 31 December 2021, a total of 21 cases in domestic pig farms and 1875 ASFV-infected wild boars have been confirmed in the country. With the continued circulation of ASF in wild boars, and subsequent outbreaks in domestic pigs, concerns were raised about the possible changes in virulence occurring among African swine fever viruses (ASFV) circulating in South Korea. In this study, four Korean ASFV strains isolated from domestic pig farms at different time points between 2019 and 2021 were chosen, and used to experimentally infect domestic pigs by intramuscular inoculation to compare their virulence. All challenged pigs died at 4-9 days post-inoculation, with many showing clinical symptoms of fever, depression, loss of appetite, and recumbency. Gross lesions observed at necropsy included enlargement and hemorrhage of the lymph nodes and hydropericardium. The study showed that all four Korean ASFV isolates caused acute forms of illness, which supports the view that virulence among the circulating ASFV isolates in South Korea remained unchanged and highly virulent during this period.

Carcinogenesis from chronic exposure to radio-frequency radiation

The past two decades have seen exponential growth in demand for wireless access that has been projected to continue for years to come. Meeting the demand would necessarily bring about greater human exposure to microwave and radiofrequency (RF) radiation. Our knowledge regarding its health effects has increased. Nevertheless, they have become a focal point of current interest and concern. The cellphone and allied wireless communication technologies have demonstrated their direct benefit to people in modern society. However, as for their impact on the radiation health and safety of humans who are unnecessarily subjected to various levels of RF exposure over prolonged durations or even over their lifetime, the jury is still out. Furthermore, there are consistent indications from epidemiological studies and animal investigations that RF exposure is probably carcinogenic to humans. The principle of ALARA-as low as reasonably achievable-ought to be adopted as a strategy for RF health and safety protection.

Preliminary study of silk fibroin porous scaffold for oral soft-tissue thickening

OBJECTIVES

This study aimed to investigate the feasibility of three different concentrations of silk-fibroin porous scaffolds applied to oral soft-tissue thickening in vivo.

METHODS

Silk-fibroin scaffolds with three different concentrations (1 wt%, 3 wt%, and 5 wt%; denoted as SF1, SF3, and SF5, respectively) were prepared by freeze drying and methanol enhancement. The scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis. Pore size, porosity, and in vitro degradation rate were also evaluated. The three groups of scaffold materials (the experimental sides) and the collagen matrix (the control side) were implanted into the oral mucosa of New Zealand white rabbits. Changed in mucosa thickness before and 3 months after operation were compared. The in vivo metabolism and regeneration effect of each group were observed by histological hematoxylin-eosin (HE) and Masson staining.

RESULTS

SEM showed that the three groups of scaffolds were all cross-linked porous structures. XRD and FTIR showed that the three scaffolds were dominated by a relatively stable Silk Ⅱ structure, which degraded more slowly in vitro. Among them, SF3 had the largest pore size (133.40 μm±22.85 μm) and moderate porosity (90.05%±6.68%). In vivo results showed that the thickening effect of SF1 was similar to that of the control group because of insufficient space-maintenance property. Meanwhile, the properties of SF3 and SF5 were more stable, and the thickening effect was significantly better than those of the control group. However, unlike SF5 that induced obvious inflammation, SF3 showed better degradation, more fibrosis and angiogenesis, and less inflammatory response in vivo.

CONCLUSIONS

Silk-fibroin scaffolds can be applied to effectively thicken soft tissues, among which SF3 (3 wt%) silk fibroin scaffold exhibited the best physicochemical properties, histocompatibility, and mucosal-thickening effect.

Multichannel stimulation module as a tool for animal studies on cortical neural prostheses

Intracortical microstimulation to the visual cortex is thought to be a feasible technique for inducing localized phosphenes in patients with acquired blindness, and thereby for visual prosthesis. In order to design effective stimuli for the prosthesis, it is important to elucidate relationships between the spatio-temporal patterns of stimuli and the resulting neural responses and phosphenes through pre-clinical animal studies. However, the physiological basis of effective spatial patterns of the stimuli for the prosthesis has been little investigated in the literature, at least partly because that the previously developed multi-channel stimulation systems were designed specifically for the clinical use. In the present, a 64-channel stimulation module was developed as a scalable tool for animal experiments. The operations of the module were verified by not only dry-bench tests but also physiological animal experiments in vivo. The results demonstrated its usefulness for examining the stimulus-response relationships in a quantitative manner, and for inducing the multi-site neural excitations with a multi-electrode array. In addition, this stimulation module could be used to generate spatially patterned stimuli with up to 4,096 channels in a dynamic way, in which the stimulus patterns can be updated at a certain frame rate in accordance with the incoming visual scene. The present study demonstrated that our stimulation module is applicable to the physiological and other future studies in animals on the cortical prostheses.

Effect of electroacupuncture on cyclic adenosine monophosphate-protein kinase A-vanillic acid receptor subtype 1 of the transient receptor potential/PLK-protein kinase C-vanillic acid receptor subtype 1 of the transient receptor potential pathway based on RNA-seq analysis in prostate tissue in rats with chronic prostatitis/chronic pelvic pain syndrome

Objective

To investigate the analgesic mechanism of electroacupuncture (EA) in rats with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

Methods

Thirty male SD rats were randomly divided into sham group, model group and EA group, with ten rats in each group. The CP/CPPS model was prepared by injecting 50 μL of complete Freund's adjuvant (CFA) into the ventral lobes of the prostate tissue, and the sham group was injected with the same dose of saline. After 14 days of modeling, EA was applied to Guanyuan (CV4), Zhongji (CV3), Sanyinjiao (SP6) and Huiyang (BL35) in the EA group. After four courses, H&E staining was performed to observe the prostate tissue morphology, transcriptome sequencing (RNA-Seq) was performed for each group, and the selected signaling pathways were verified by qRT-PCR.

Results

The RNA-Seq analysis results suggested that the analgesic effect of EA on CP/CPPS may be achieved by regulating prostate gene expression, which may be related to multiple biological processes and signaling pathways. qRT-PCR results showed that the vanillic acid receptor subtype 1 of the transient receptor potential (TRPV1), phospholipase C (PLC), protein kinase C (PKC), cyclic adenosine monophosphate (cAMP), and protein kinase A (PKA) were all upregulated in the model group compared to the sham group (p < 0.01). Compared with the model group, TRPV1, PLC, PKC, cAMP, and PKA were all downregulated in the EA group (p < 0.05, p < 0.01).

Conclusion

The analgesic mechanism of EA on CP/CPPS may be achieved through modulation of cAMP-PKA-TRPV1/PLC-PKC-TRPV1 signaling pathway.

[Consideration on Animal Experiment in PET/CT]

PET/CT imaging can reflect the physiological metabolic process in living body which is the model experiment incapable to simulate. Animal experiment may be considered for systematic validation of PET/CT products. The obtained research data can be used to evaluate the feasibility, effectiveness and safety of PET/CT products, and be submitted as supporting documents for research data or clinical evaluation data when doing product registration or alteration registration. In this study, the functions and advantages of animal experiments were expounded, and relevant research cases were given as well as the issues that should be paid attention to. It can be a reference for the validation and review of PET/CT products.

[Development of Nasal Continuum Minimally Invasive Surgical Robot System]

In order to improve the operation difficulties in the narrow space of the nasal maxillary sinus, the nasal continuum minimally invasive surgical robot system is designed. The ball-and-socket joints and NiTiNol tubes are used as the main body of the continuum structure to improve the degree of freedom. The hardware systems and software systems are designed. The security control policies are planned. Finally, the robot confirmed prototype experiments are conducted and the feasibility of continuum robot confirmed through master-slave control experiment and animal experiment.

[Mechanism of Liangfu Pills in treatment of functional dyspepsia: based on network pharmacology and experimental verification]

This study aims to explore the potential mechanism of Liangfu Pills in the treatment of functional dyspepsia(FD) based on network pharmacology and molecular docking, and verify the mechanism by animal experiment. The active components of Liangfu Pills were screened from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and the targets of Liangfu Pills were predicted by SwissTargetPrediction. The targets of FD were retrieved from GeneCards. On this basis, the common targets of the disease and the pills were yielded and the protein interaction was retrieved based on STRING. The core targets were screened out, followed by Gene Oncology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis with DAVID. Finally, molecular docking was carried out with the help of AutoDock Tools to predict the binding degree between the effective components of Liangfu Pills and core targets. A total of 19 active components of Liangfu Pills and 591 FD-related targets were screened out by network pharmacology, of which 253 were common targets of the disease and the prescription. Liangfu Pills was mainly involved in the biological processes of response to drug, negative regulation of transcription, positive regulation of apoptotic process, and cell surface receptor signaling pathway, and the KEGG pathways of hypoxia-inducible factor-1(HIF-1) signaling pathway, serotonergic synapse, tumor necrosis factor(TNF) signaling pathway, cyclic adenosine monophosphate(cAMP) signaling pathway, calcium signal pathway, and inflammatory mediator regulation of transient receptor potential(TRP) channels. The results of molecular docking showed that the key active components of Liangfu Pills had certain binding activity to the targets mitogen-activated protein kinase 1(MAPK1), protein kinase B(AKT1), transient receptor potential cation channel subfamily V member 1(TRPV1), 5-hydroxytryptamine receptor 1 A(HTR1 A), and 5-hydroxytryptamine receptor 2 A(HTR2 A). FD was induced in rats, and then Liangfu Pills was given to FD rats for 7 days. The results showed that Liangfu Pills could significantly relieve the symptoms of FD rats, significantly increase the expression of 5-hydroxytryptamine(5-HT), and down-regulate the expression of TRPV1. Through network pharmacology, molecular docking, and experimental verification, this study proved that Liangfu Pills improved FD through multiple components and multiple targets. The result lays a basis for further research on the mechanism and clinical application of Liangfu Pills in the treatment of FD.

Naoluo Xintong Decoction in the Treatment of Ischemic Stroke: A Network Analysis of the Mechanism of Action

The mechanism of action of Naoluo Xintong decoction (NLXTD) for the treatment of ischemic stroke (IS) is unknown. We used network analysis and molecular docking techniques to verify the potential mechanism of action of NLXTD in treating IS. The main active components of NLXTD were obtained from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, and IS targets were collected from the Online Mendelian Inheritance in Man (OMIM), GeneCards, and Drugbank databases; their intersection was taken. In addition, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed and used to build protein-protein interaction networks. AutoDock Vina software was used for molecular docking, and animal experiments were conducted to verify the results. Hematoxylin and eosin staining was used to observe the brain morphology of rats in each group, and real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression level of relative mRNA in the brain tissue of rats. Western blot was used to detect the expression level of relative protein in the brain tissue of rats. Network analysis and molecular docking results showed that CASP3, NOS3, VEGFA, TNF, PTGS2, and TP53 are important potential targets for NLXTD in the treatment of IS. RT-qPCR and western blot results showed that NLXTD inhibited the expression of CASP3, TNF, PTGS2, and TP53 and promoted the expression of VEGFA and NOS3. NLXTD treats IS by modulating pathways and targets associated with inflammation and apoptosis in a multicomponent, multitarget manner.

A coordinate positioning puncture method under robot-assisted CT-guidance: phantom and animal experiments

PURPOSE

To evaluate the accuracy of the robot-assisted computed tomography (CT)-guided coordinate positioning puncture method by phantom and animal experiments.

MATERIAL AND METHODS

In the phantom experiment, seven robot-assisted punctures were made to evaluate the accuracy of the method. In the animal experiment, 18 punctures (nine robotic and nine manual) were made in the livers of nine rabbits. The indicators, such as needle-tract length, angle deviation, puncture accuracy, number of scans required, and radiation exposure dose were compared between manual and robotic punctures. The paired-samples t-test was used for analysis.

RESULTS

In the phantom experiment, the mean accuracy of seven punctures was 2.67 mm. In the animal experiment, there was no significant difference in needle-tract length (32.58 mm vs. 34.04 mm, p = .606), angle deviation (17.21° vs. 21.23° p = .557) and puncture accuracy (8.42 vs. 8.77 mm, p = .851) between the two groups. However, the number CT scans required (2.44 vs. 3.33, p = .002), and the radiation exposure dose (772.98 vs. 1077.89 mGy/cm, p = .003) were lower in the robot group than in the manual group.

CONCLUSIONS

The coordinate positioning puncture method under robot-assisted CT-guidance can reach an accuracy that is comparable to that of the traditional manual CT-guided puncture method and with fewer CT scanning times accompanied with a lower radiation dosage.

Cardiac Arrest in Pigs With 48 hours of Post-Resuscitation Care Induced by 2 Methods of Myocardial Infarction: A Methodological Description

Background

Systematic reviews have disclosed a lack of clinically relevant cardiac arrest animal models. The aim of this study was to develop a cardiac arrest model in pigs encompassing relevant cardiac arrest characteristics and clinically relevant post‐resuscitation care.

Methods and Results

We used 2 methods of myocardial infarction in conjunction with cardiac arrest. One group (n=7) had a continuous coronary occlusion, while another group (n=11) underwent balloon‐deflation during arrest and resuscitation with re‐inflation after return of spontaneous circulation. A sham group was included (n=6). All groups underwent 48 hours of intensive care including 24 hours of targeted temperature management. Pigs underwent invasive hemodynamic monitoring. Left ventricular function was assessed by pressure‐volume measurements. The proportion of pigs with return of spontaneous circulation was 43% in the continuous infarction group and 64% in the deflation‐reinflation group. In the continuous infarction group 29% survived the entire protocol while 55% survived in the deflation‐reinflation group. Both cardiac arrest groups needed vasopressor and inotropic support and pressure‐volume measurements showed cardiac dysfunction. During rewarming, systemic vascular resistance decreased in both cardiac arrest groups. Median [25%;75%] troponin‐I 48 hours after return of spontaneous circulation, was 88 973 ng/L [53 124;99 740] in the continuous infarction group, 19 661 ng/L [10 871;23 209] in the deflation‐reinflation group, and 1973 ng/L [1117;1995] in the sham group.

Conclusions

This article describes a cardiac arrest pig model with myocardial infarction, targeted temperature management, and clinically relevant post‐cardiac arrest care. We demonstrate 2 methods of inducing myocardial ischemia with cardiac arrest resulting in post‐cardiac arrest organ injury including cardiac dysfunction and cerebral injury.

Establishment of a Novel Method for Spinal Discectomy Surgery in Elderly Rats in an In Vivo Spinal Fusion Model

The rat model is a common model for intervertebral disc (IVD) and spinal research. However, complications remain challenging. Standard Operating Procedures (SOPs) are validated methods to minimize complications and improve safety and quality of studies. However, a SOP for rat spinal fusion surgery has been missing until now. Therefore, the aim of the study was to develop a SOP for spinal tail disc surgery in elderly Wistar rats (419.04 ± 54.84 g). An initial preoperative, intraoperative, and postoperative surgical setup, including specific anaesthesia and pain management protocols, was developed. Anaesthesia was induced by subcutaneous injection of a pre-mixture of fentanyl, midazolam, and medetomidin with the addition of 0.5% isoflurane in oxygen and caudal epidural analgesia. The surgery itself consisted of the fixation of a customized external ring fixator with ⌀ 0.8 mm Kirschner wires at the proximal rat tail and a discectomy and replacement with bone morphogenetic protein coated beta-tricalcium-phosphate carrier. The postoperative setup included heating, analgesia with buprenorphine, and meloxicam, as well as special supplementary food. Anaesthesia, surgery, and pain management were sufficient. In the presented optimized SOP, no animals developed any complications. A SOP for spinal surgery in elderly rats in an in vivo spinal fusion model was developed successfully. This novel protocol can improve transparency, reproducibility, and external validity in experimental rat spinal surgery experiments.

Natural Horizontal Gene Transfer of Antimicrobial Resistance Genes in Campylobacter spp. From Turkeys and Swine

Antibiotic-resistant Campylobacter constitutes a serious threat to public health. The clonal expansion of resistant strains and/or the horizontal spread of resistance genes to other strains and species can hinder the clinical effectiveness of antibiotics to treat severe campylobacteriosis. Still, gaps exist in our understanding of the risks of acquisition and spread of antibiotic resistance in Campylobacter. While the in vitro transfer of antimicrobial resistance genes between Campylobacter species via natural transformation has been extensively demonstrated, experimental studies have favored the use of naked DNA to obtain transformants. In this study, we used experimental designs closer to real-world conditions to evaluate the possible transfer of antimicrobial resistance genes between Campylobacter strains of the same or different species (Campylobacter coli or Campylobacter jejuni) and originating from different animal hosts (swine or turkeys). This was evaluated in vitro through co-culture experiments and in vivo with dual-strain inoculation of turkeys, followed by whole genome sequencing of parental and newly emerged strains. In vitro, we observed four independent horizontal gene transfer events leading to the acquisition of resistance to beta-lactams (blaOXA), aminoglycosides [aph(2′′)-If and rpsL] and tetracycline [tet(O)]. Observed events involved the displacement of resistance-associated genes by a mutated version, or the acquisition of genomic islands harboring a resistance determinant by homologous recombination; we did not detect the transfer of resistance-carrying plasmids even though they were present in some strains. In vivo, we recovered a newly emerged strain with dual-resistance pattern and identified the replacement of an existing non-functional tet(O) by a functional tet(O) in the recipient strain. Whole genome comparisons allowed characterization of the events involved in the horizontal spread of resistance genes between Campylobacter following in vitro co-culture and in vivo dual inoculation. Our study also highlights the potential for antimicrobial resistance transfer across Campylobacter species originating from turkeys and swine, which may have implications for farms hosting both species in close proximity.

Evaluation of Resorption and Osseointegration of Autogenous Bone Ring Grafting in Vertical Bone Defect With Simultaneous Implant Placement in Dogs

The aim of this research was to evaluate the resorption and osseointegration of an autogenous bone ring, which was grafted in a local vertical alveolar defect with simultaneous implant placement. Six Beagle dogs were enrolled in the study; their 4 nonadjacent mandibular premolars were extracted, and the buccal plate was removed to create bone defects in 2 of the 4 sites. Three months after extraction, Straumann implants (Ø 3.3 mm, length of 8 mm) were placed in the bone defect sites with simultaneous autogenous bone ring grafting and in the conventional extraction sites. After a 3-month healing period and a 3-month loading period, the animals were euthanized. The harvested samples were analyzed using micro-computed tomography (CT) scanning and histological analysis. From the micro-CT measurements, the average vertical bone resorption of the bone ring was 0.23 ± 0.03 mm, which was not significantly different from that around the conventional implant, 0.24 ± 0.12 mm (P > .05). The ratio of the bone volume to the total volume of the bone ring group was 91.11 ± 0.02, which was higher than that of the control group, 88.38 ± 2.34 (P < .05). From the hard tissue section, the bone rings developed fine osseointegration with the implants and the base alveolar bone. The results suggest autogenous bone ring grafting with simultaneous implant placement can survive in a local vertical bone defect with little bone resorption and good osseointegration in dogs with strict management. A bone ring graft must be compared with guided bone regeneration, and a larger and longer observation must be confirmed in clinical patients.

Addition of autogenous bone chips to deproteinized bovine bone mineral does not have additional benefit in lateral ridge augmentation-A preclinical in vivo experimental study

OBJECTIVE

To compare the outcome after extensive lateral guided bone regeneration using deproteinized bovine bone mineral (DBBM) with or without autogenous bone chips in a canine model of chronic horizontal alveolar ridge defect.

MATERIALS AND METHODS

The second, third and fourth lower premolars of both sides were extracted, and the buccal bone walls were completely removed in five beagle dogs. After 4 weeks, DBBM particles mixed with autogenous bone chips at a ratio of 1:1 were grafted at one side (DBBM/Auto group), while DBBM particles alone were grafted at the contralateral side (DBBM group). The graft materials on both sides were covered by a resorbable collagen membrane and fixation pins. Microcomputed tomographic volume and histomorphometric analyses were performed at 16 weeks post-surgery.

RESULTS

The ridges of both groups were recovered horizontally, but new bone formation beyond the original ridge contour at the defect site was not found. The DBBM group exhibited a larger total radiographic augmented volume and new bone volume compared with the DBBM/Auto group, but the differences were minimal (p > .05). Histologically, the regenerated area and new bone area were also slightly larger without any statistical significance in the DBBM group than in the DBBM/Auto group (p > .05).

CONCLUSION

The addition of autogenous bone chips to DBBM for lateral ridge augmentation may confer no advantage over grafting DBBM alone with respect to both space maintenance and de novo bone formation in dogs.

Breeding and Maintenance of Immunodeficient Mouse Lines under SPF Conditions-A Call for Individualized Severity Analyses and Approval Procedures

In the EU, the breeding of genetically modified laboratory animals is, by definition, an animal experiment if the offspring may experience pain, suffering, or harm. In order to determine the actual burden of genetically modified mice, established methods are available. However, the breeding of immunodeficient mice is considered an experiment requiring a permit, even if no pain, suffering or harm is observed under scientifically required defined hygienic housing conditions, as determined by established methods of severity assessment. This seems contradictory and leads to uncertainty among scientists. With this commentary, we would like to shed light on this topic from different perspectives and propose a solution in terms of individualized severity assessment and approval procedures.

A Surgical Pen-Type Probe Design for Real-Time Optical Diagnosis of Tumor Status Using 5-Aminolevulinic Acid

A surgical microscope is large in size, which makes it impossible to be portable. The distance between the surgical microscope and the observation tissue is 15–30 cm, and the adjustment range of the right and left of the camera is a maximum of 30°. Therefore, the surgical microscope generates an attenuation (above 58%) of irradiation of the optical source owing to the long working distance (WD). Moreover, the observation of tissue is affected because of dazzling by ambient light as the optical source power is strong (55 to 160 mW/cm²). Further, observation blind spot phenomena will occur due to the limitations in adjusting the right and left of the camera. Therefore, it is difficult to clearly observe the tumor. To overcome these problems, several studies on the handheld surgical microscope have been reported. In this study, a compact pen-type probe with a portable surgical microscope is presented. The proposed surgical microscope comprises a small and portable pen-type probe that can adjust the WD between the probe and the observed tissue. In addition, it allows the adjustment of the viewing angle and fluorescence brightness. The proposed probe has no blind spots or optical density loss.

Study on the biocompatibility of Ga-based and Al-assisted self-driven liquid metals in cell and animal experiments for drug delivery

BACKGROUND

With inherent flexibility, high electroconductivity, excellent thermal conductivity, easy printability and biosafety, Ga-based functional liquid metals (LMs) have been extensively evaluated for biomedical applications. When implanted in the biological environment, the safety of the LMs is a major concern for future application.

METHODS

In this study, we conducted several biocompatibility assessments through immersion experiments, in vitro cytotoxicity experiments and in vivo embedding experiments.

RESULTS

The results showed that both the Al-assisted self-driven LM and the LM per se own good biocompatibility and retrievable properties when contacted with living organisms for a relatively long period of time.

CONCLUSION

This study provides preliminary evidence about the biocompatibility of the functional LM materials, such as LM-based soft machine, which would promote and inspire other research to address other tough biomedical issues.

Prevention of the rise in plasma cholesterol and glucose levels by kaki-tannin and characterization of its bile acid binding capacity

BACKGROUND

Bile acid-binding agents, such as cholestyramine and colesevelam, improve both cholesterol and glucose metabolism. Kaki-tannin, a polymerized condensed tannin derived from persimmon (Diospyros kaki), has been shown to have bile acid-binding capacity and a hypocholesterolemic effect. However, its effects on glucose metabolism have not been well studied, and the binding selectivity of kaki-tannin to bile acid molecules has not been reported.

RESULTS

In vivo experiments using mice with high-fat diet-induced obesity showed that kaki-tannin intake (20 g kg^-1 of the diet) increased fecal bile acid excretion by 2.3-fold and prevented a rise in plasma cholesterol levels and fasting plasma glucose levels. Kaki-tannin also suppressed the development of impaired glucose tolerance. To characterize the bile acid-binding capacity of kaki-tannin, we investigated its capacity to bind to eight types of bile acid and cholesterol in vitro. Kaki-tannin showed strong capacity to bind to lithocholic acid (85.5%), which has one hydroxy group. It also showed moderate capacity to bind to bile acids with two hydroxy groups (53.3%), followed by those with three hydroxy groups (39.0%), but kaki-tannin did not show binding capacity to cholesterol. These results suggest that the binding capacity of kaki-tannin to bile acids tends to decrease as the number of hydroxy groups increases. Interestingly, the binding capacity of kaki-tannin correlated with that of cholestyramine (correlation coefficient: r = 0.900).

CONCLUSION

Our findings indicate that kaki-tannin binds preferentially to bile acids with fewer hydroxy groups and has beneficial effects on glucose metabolism as well as cholesterol metabolism. © 2020 Society of Chemical Industry.

First Outbreak of an H5N8 Highly Pathogenic Avian Influenza Virus on a Chicken Farm in Japan in 2020

On 5 November 2020, a confirmed outbreak due to an H5N8 highly pathogenic avian influenza virus (HPAIV) occurred at an egg-hen farm in Kagawa prefecture (western Japan). This virus, A/chicken/Kagawa/11C/2020 (Kagawa11C2020), was the first HPAI poultry isolate in Japan in 2020 and had multiple basic amino acids—a motif conferring high pathogenicity to chickens—at the hemagglutinin cleavage site. Mortality of chickens was 100% through intravenous inoculation tests performed according to World Organization for Animal Health criteria. Phylogenetic analysis showed that the hemagglutinin of Kagawa11C2020 belongs to clade 2.3.4.4B of the H5 Goose/Guangdong lineage and clusters with H5N8 HPAIVs isolated from wild bird feces collected in Hokkaido (Japan) and Korea in October 2020. These H5N8 HPAIVs are closely related to H5N8 HPAIVs isolated in European countries during the winter of 2019–2020. Intranasal inoculation of chickens with 10⁶ fifty-percent egg infectious doses of Kagawa11C2020 revealed that the 50% chicken lethal dose was 10^4.63 and the mean time to death was 134.4 h. All infected chickens demonstrated viral shedding beginning on 2 dpi—before clinical signs were observed. These results suggest that affected chickens could transmit Kagawa11C2020 to surrounding chickens in the absence of clinical signs for several days before they died.

Effects of ATP-binding cassette transporter G2 in extracellular vesicles on drug resistance of laryngeal cancer cells in in vivo and in vitro

Drug resistance is one of the main factors limiting the efficacy of chemotherapy in patients with laryngeal cancer; thus, it is important to investigate the drug resistance of laryngeal cancer. In the present study, the mechanism of the regulation of drug resistance in laryngeal cancer cells by ATP-binding transporter G2 (ABCG2) that is present in the extracellular vesicles (EVs) released by drug-resistant cells was studied in vivo and in vitro. A cisplatin (CDDP)-resistant cell line (AMC-HN-8/CDDP) was established from AMC-HN-8 cells by continuous exposure to increasing concentrations of CDDP. The EVs extracted from the culture medium of AMC-HN-8/CDDP and AMC-HN-8 cells were termed EVs1 and EVs2, respectively. Following 48-h treatment of AMC-HN-8 cells with EVs1 or EVs2, the cells were designated as AMC-HN-8-EVs1 or AMC-HN-8-EVs2. Nude mice bearing AMC-HN-8-EVs1 and AMC-HN-8 cell-derived xenograft tumors were established to detect the effects of EVs on drug resistance. The resistance index of AMC-HN-8/CDDP cells to CDDP was 5.60, which was determined by the MTT assay. The mRNA and protein expression levels of ABCG2 in AMC-HN-8/CDDP cells and EVs1 were significantly higher compared with those in AMC-HN-8 cells and EVs2, respectively (P<0.01). The ABCG2 mRNA and protein levels, and the proliferation index of AMC-HN-8-EVs1 cells were significantly higher compared with those of AMC-HN-8-EVs2 and AMC-HN-8 cells (P<0.01), whereas the apoptotic rate was significantly lower (P<0.01). The mean volume of subcutaneous tumor xenografts in the test group (inoculated with AMC-HN-8-EVs1 cells and intraperitoneally injected with 3 mg/kg CDDP) was significantly higher compared with that in the control group (inoculated with AMC-HN-8 cells and intraperitoneally injected with 3 mg/kg CDDP) (P<0.01), whereas the apoptotic rate of tumor cells was significantly lower (P<0.01). The ABCG2 mRNA and the protein expression levels in the tumor cells of the test group were significantly higher compared with those in the blank (inoculated with AMC-HN-8 cells and was intraperitoneally injected with normal saline) and control groups (P<0.01). The high expression levels of ABCG2 in laryngeal carcinoma cells affected the drug resistance of the cells. The EVs released by drug-resistant cells upregulated the expression of ABCG2 and induced drug resistance in laryngeal carcinoma cells, which may be dependent on the ABCG2 gene carried by the EVs.

The Effect of Curcumin on the Prevention of Myringosclerosis in Rats

OBJECTIVE

The aim of this study was to investigate the preventative effect of oral curcumin (CMN) on myringosclerosis (MS) in an experimental rat model.

METHODS

The study included 21 female Wistar albino rats randomly separated into three groups. Group 1 was given no treatment (control group). In Group 2 and Group 3, the tympanic membrane (TM) was perforated using a sterile ear pick. The rats in Group 3 were administered oral CMN 200 mg/kg/day. All rats were sacrificed after 16 days. Otomicroscopic and histopathologic examinations were performed on the tympanic membranes.

RESULTS

Histopathologic examinations revealed that there were statistically significant differences between Group 2 and Group 3 in terms of MS degrees (p<0.001) and mean thicknesses of TMs (p<0.001), but there were no differences between Group 1 and Group 3. In respect of MS detected by otomicroscopy, a statistically significant difference was determined between Groups 1 and 2 (p<0.001) and between Groups 2 and 3 (p<0.01), but there was no significant difference between Group 1 and Group 3 (p=0.575).

CONCLUSION

Orally administered CMN can prevent myringosclerosis formation in experimentally induced myringotomies.

Towards Accurate Microwave Characterization of Tissues: Sensing Depth Analysis of Open-Ended Coaxial Probes with Ex Vivo Rat Breast and Skin Tissues

Dielectric properties of biological materials are commonly characterized with open-ended coaxial probes due to the broadband and non-destructive measurement capabilities. Recently, potential diagnostics applications of the technique have been investigated. Although the technique can successfully classify the tissues with different dielectric properties, the classification accuracy can be improved for tissues with similar dielectric properties. Increase in classification accuracy can be achieved by addressing the error sources. One well-known error source contributing to low measurement accuracy is tissue heterogeneity. To mitigate this error source, there is a need define the probe sensing depth. Such knowledge can enable application-specific probe selection or design. The sensing depth can also be used as an input to the classification algorithms which can potentially improve the tissue classification accuracy. Towards this goal, this work investigates the sensing depth of a commercially available 2.2 mm aperture diameter probe with double-layered configurations using ex vivo rat breast and skin tissues. It was concluded that the dielectric property contrast between the heterogeneous tissue components has an effect on the sensing depth. Also, a membrane layer (between 0.4-0.8 mm thickness) on the rat wet skin tissue and breast tissue will potentially affect the dielectric property measurement results by 52% to 84%.

Influence of preformed bone defects on key pathogens and bone loss during experimental peri-implantitis formation in a canine model

PURPOSE

To determine the impact of experimentally preformed peri-implant crater-shaped bone defects on the evolution of in situ microbiota and development of bone defects compared to those induced over time by ligature placement only.

METHODS

Implants were installed in the mandibles of eight dogs. Standardized bone defects were preformed in four test animals but not in the other four control animals, prior to implant (3.3 mm × 8 mm) installation. After 2 months of healing, peri-implantitis was induced with silk ligatures in both groups for 2 months. Microbial samples were obtained from implants and teeth for analysis at three time points (qPCR), and the average depths of the bone defects were measured.

RESULTS

At the baseline, the total marker load of periodontal-pathogenic bacteria (TML) for teeth accounted for 5.2% (0-17.4%). After implant healing, TMLs for implants and teeth were comparable (7.1% [0.3-17.4%]). The TML of both groups was 3.5%, 2 months after ligature placement. Bone defects had a mean depth of 1.84 mm at preformed defects and 1.64 mm at control sites (P > 0.05).

CONCLUSION

Preformed defects in the test group showed comparable results to the control group in terms of TML, the incidence of periodontal-pathogenic bacteria, and bone defect depth.

Collagen-Based Matrices for Osteoconduction: A Preclinical In Vivo Study

The aim of this study was to evaluate the influence of additional hydroxyapatite (HA) in collagen-based matrices (CM) and membrane placement on bone formation in calvarial defects. Critical size defects in the calvaria of 16 New Zealand White Rabbits were randomly treated with CM or mineralized collagen-based matrices (mCM). Half of the sites were covered with a collagen membrane. Animals were euthanized after 12 weeks of healing. The samples were studied by micro-CT and histology. Newly formed lamellar bone was observed in all samples at the periphery of the defect. In the central areas, however, new bone composed of both woven and lamellar bone was embedded in the soft tissue. Samples treated with mCM showed more residual biomaterial and induced more small bony islands in the central areas of the defects than samples with CM. Nevertheless, a complete defect closure was not observed in any of the samples at 12 weeks. Membrane placement resulted in a decrease in bone density and height. Significant differences between the groups were revealed only between CM groups with and without membrane coverage for bone height in the central area of the defect. Neither mineralization of CM nor membrane placement improved the osteogenic capacity in this particular defect. Nevertheless, mineralisation influenced bone density without a membrane placement and bone volume underneath a membrane. CM may be used as a scaffold in bone regeneration procedures, without the need of a membrane coverage. Further preclinical studies are warrant to optimise the potential of mCM.

Histological Evaluation of Gingival and Intrabony Periodontal Defects Treated with Platelet-rich Fibrin Using Different Protocols: A Canine Study

PURPOSE

To histologically compare the effects of platelet-rich fibrin (PRF) produced using different protocols on periodontal wound healing/regeneration in periodontal defects in dogs.

MATERIALS AND METHODS

Dehiscence-type gingival recession and two-wall intrabony defects were created bilaterally in the maxillary canines and mandibular premolars, respectively, in four beagle dogs. The recession defects were randomly treated with coronally advanced flap (CAF) alone, CAF and PRF produced via fixed-angle centrifugation (F-PRF; Leukocyte and PRF (L-PRF) protocol) or CAF and PRF produced via horizontal centrifugation (H-PRF). After 2 weeks, the two-wall intrabony defects were randomly treated as follows: open flap debridement (OFD), OFD + F-PRF, OFD + H-PRF and OFD + heated albumin with PRF using bio-heat technologies (Alb-PRF). Eight weeks after the 2nd reconstructive surgery, the animals were euthanised for histological evaluation.

RESULTS

In the PRF-applied defects, new bone and new cementum formation occurred to varying degrees regardless of the protocols used to produce PRF. Particularly in the two-wall intrabony defects, new bone formation extended from the host bone toward the coronal region of the defects in the H-PRF applied sites compared with those in the OFD, F-PRF and Alb-PRF groups, and the H-PRF group showed the greatest amount of newly formed cementum.

CONCLUSION

PRF induced periodontal regeneration in gingival recession and two-wall intrabony defects in dogs. Further studies are needed to determine the optimal protocol for obtaining predictable periodontal regeneration in periodontal defects in humans.

Comparison of Cilostazol and Naftidrofuryl in an Experimental Acute Ischemia-Reperfusion Model

INTRODUCTION

Naftidrofuryl and cilostazol are drugs with proven efficacy in the treatment of claudication in peripheral vascular disease. In this experimental study, we evaluated the effects of naftidrofuryl and cilostazol in ischemia-reperfusion (IR) injury on various tissues.

MATERIALS AND METHODS

40 male albino Wistar rats (8-12 weeks old, 250-350 g.) are randomly divided into 4 groups: Control (Group 1), sham (group 2), cilostazol pre-treatment (group 3), naftidrofuryl pre-treatment (group 4). During 21 days placebo is given to group 2, 12 mg/kg/day cilostazol is given to group 3, 50 mg/kg/day naftidrofuryl is given to group 4 orally. Ischemia and reperfusion are induced at the lower hind limb in Groups 2, 3 and 4. Ischemic muscle, kidney, liver, heart, brain and blood samples are obtained. The total antioxidant capacity, oxidant levels and oxidative stress index are studied for each group.

RESULTS

Both drugs have protective effects of remote organ injury following IR. Systemic effects are similar to each other, both have protective effects of IR injury. It showed no statistical significance in the total antioxidant capacity. Total oxidant levels are significantly affected by cilostazol in the heart (p < 0.01) and by naftidrofuryl in the liver (p < 0.01). The effect on oxidative stress was only significant with cilostazol on the heart (p < 0.01).

CONCLUSION

Cilostazol and naftidrofuryl had beneficial effects in all tissues against tissue damage caused by IR injury. In ischemic muscle, kidney and heart cilostazol had improved outcomes comparing to naftidrofuryl. Naftidrofuryl had benefits over cilostazol in liver tissue.

[Mechanism and experimental verification of Sijunzi Decoction in treatment of ulcerative colitis based on network pharmacology]

To explore the mechanism of Sijunzi Decoction in the treatment of ulcerative colitis(UC) based on network pharmacology. The active components and corresponding targets of Sijunzi Decoction were extracted with Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and the targets were standardized with the help of Uniprot database. The related targets of UC were obtained through GeneCards database and Disgenet database, and the intersection targets of drugs and diseases were screened by R language. The visual regulation network of &quot;active ingredient-disease target&quot; of Sijunzi Decoction was constructed by Cytoscape software, and the protein-protein interaction network was constructed by STRING database. The functional enrichment analysis of gene ontology(GO) and the enrichment analysis of Kyoto encyclopedia of genes and genomes(KEGG) pathway were carried out on Bioconductor platform, and some of the targets were verified by animal experiments. Through database analysis, a total of 135 active components of Sijunzi Decoction, 114 predicted targets and 80 common targets with UC were obtained. The core target proteins included interleukin 6(IL-6), caspase-3(CASP3), vascular endothelial growth factor A(VEGFA), epidermal growth factor receptor(EGFR) and so on. GO functional enrichment analysis involved 102 items, which mainly affected transcription factor activity, enzyme activity, receptor activity and biochemical process regulation. KEGG pathway enrichment analysis showed that 120 items were involved in human cytomegalovirus infection, cancer, apoptosis, inflammation and other pathways. Mouse experiments showed that Sijunzi Decoction could down-regulate the expression of target proteins IL-6 and caspase-3 and inhibit intestinal epithelial cell apoptosis. The treatment of UC with Sijunzi Decoction is the result of the interaction among multi-components, multi-targets and multi-pathways. It is proved by experiments that Sijunzi Decoction may play an effective role by regulating the expression of IL-6 and caspase-3, and getting involved in apoptosis, inflammation and other pathways.

Comparison of KD-SR-01 robotic partial nephrectomy and 3D-laparoscopic partial nephrectomy from an operative and ergonomic perspective: A prospective randomized controlled study in porcine models

BACKGROUND

To investigate the feasibility, validity and security of a new robot platform called KD-SR-01 and compare relative merits of KD-SR-01 robotic partial nephrectomy (KD-RPN) and 3D-Laparoscopic Partial Nephrectomy (3D-LPN).

METHODS

Twelve porcine models were randomly and equally divided for KD-RPN and 3D-LPN. The perioperative outcomes, physical and mental workload of the surgeon were compared. Physical workload was evaluated with surface electromyography. Mental workload was evaluated with National Aeronautics and Space Administration Task Load Index (NASA-TLX).

RESULTS

All surgeries were performed successfully. The average docking time of KD-RPN was 6 min. The estimated blood loss was lower in KD-RPN (p < 0.05). There were no differences in all the other operative variables (p > 0.05). KD-RPN showed advantages in physical workload and was significantly superior in mental workload (p < 0.05).

CONCLUSIONS

KD-RPN is technically feasible, valid and safe in porcine models. It's comparable from operative perspective while KD-RPN had advantages over 3D-LPN from ergonomic perspective.

Evaluation of New Octacalcium Phosphate-Coated Xenograft in Rats Calvarial Defect Model on Bone Regeneration

Bone graft material is essential for satisfactory and sufficient bone growth which leads to a successful implant procedure. It is classified into autogenous bone, allobone, xenobone and alloplastic materials. Among them, it has been reported that heterogeneous bone graft material has a porous microstructure that increases blood vessels and bone formation, and shows faster bone formation than other types of bone graft materials. We observed new bone tissue formation and bone remodeling using Ti-oss^® (Chiyewon Co., Ltd., Guri, Korea), a heterologous bone graft material. Using a Sprague–Dawley rat calvarial defect model to evaluate the bone healing effect of biomaterials, the efficacy of the newly developed xenograft Ti-oss^® and Bio-Oss^® (Geistilch Pharma AG, Wolhusen, Switzerland). The experimental animals were sacrificed at 8 and 12 weeks after surgery for each group and the experimental site was extracted. The average new bone area for the Ti-oss^® experimental group at 8 weeks was 17.6%. The remaining graft material was 22.7% for the experimental group. The average new bone area for the Ti-oss^® group was 24.3% at 12 weeks. The remaining graft material was 22.8% for the experimental group. It can be evaluated that the new bone-forming ability of Ti-oss^® with octacalcium phosphate (OCP) has the bone-forming ability corresponding to the conventional products.

Mapping global research trends in stem cell therapy for inflammatory bowel disease: a bibliometric analysis from 1991 to 2019

BACKGROUND

Inflammatory bowel disease (IBD) represents a series of digestive system abnormalities and parenteral manifestations. Stem cell therapy has been regarded as a promising treatment for IBD.

METHODS

We searched Web of Science Core Collection for publications of interest from 1991 to 2019. Publication performance was analyzed using several bibliometric parameters, including Statplanet to reveal the geographic distribution of the publications, VOSviewer to identify the research landscape of hot topics, and CiteSpace to show keywords with the strongest citation bursts.

RESULTS

A total of 1230 publications were identified, of which 674 articles were analyzed further. The United States was the most productive country and Spanish researchers published the highest quality articles. At a journal level, Gastroenterology published the greatest number of articles, while articles from Gut had the highest citation number. Results from the research landscape analysis of hot topics and the top 20 terms with the strongest citation bursts indicated that animal experiments, immunocytes, intestinal epithelial cells, cytokine expression, and clinical efficacy were the main focuses of research.

CONCLUSION

Stem cell therapy for IBD is currently receiving increasing attention by researchers, with focuses on animal experiments, immunocytes, intestinal epithelial cells, cytokine expression, and clinical efficacy.

Dimensional changes of the maxillary sinus augmented with a collagenated synthetic bone block or synthetic bone particulates: A pre-clinical study in rabbits

OBJECTIVE

To compare the efficacy of a collagenated synthetic bone substitute (C-SBS) to a particulated synthetic bone substitute (P-SBS) in volume maintenance and new bone formations in a rabbit sinus model.

MATERIALS AND METHODS

Either C-SBS or P-SBS was grafted in both sinuses of 16 rabbits. Four (N = 8) or 12 (N = 8) weeks after the surgery, total augmented volume (TAV) and area (TAA), as well as new bone volume (NBV) and area (NBA), were statistically compared by radiographic and histomorphometric analyses (p < .05).

RESULTS

The differences in TAV, NBV, TAA and NBA between C-SBS and P-SBS groups at 4 weeks were not statistically significant. The TAV (267.13 ± 62.08 vs. 200.18 ± 40.32 mm³ ) and NBV (103.26 ± 10.50 vs. 71.10 ± 7.58 mm³ ) in group C-SBS were significantly higher than in group P-SBS at 12 weeks (p < .05). The TAA (19.36 ± 2.88 vs. 14.48 ± 2.08 mm² ) and NBA (5.43 ± 1.20 vs. 3.76 ± 0.78 mm² ) in group C-SBS were significantly higher than in group P-SBS at 12 weeks (p < .05).

CONCLUSIONS

Collagenated synthetic bone substitute grafted in rabbit sinuses demonstrated more favourable outcomes across all outcome measures compared to P-SBS at 12 weeks.