Acute Toxicity of Aqueous Extract from Bredemeyera floribunda Root Bark in an Animal Model.

The medicinal plant Bredemeyera floribunda Willd. is used to treat cardiovascular disease, chronic fatigue, low libido, as well as increased diuresis. However, studies considering the toxicity of this plant are scarce. Develop an aqueous extract of B. floribunda considering traditional use and determine the average lethality (LD50), signs, and symptoms of toxicity. The B. floribunda extract was obtained by immersing the root bark in ultrapure water for 18 hours at 4°C, under constant stirring. The test extract was administered in a single dose of 2.000 mg/kg by gavage to rats. Signs and symptoms of toxicity were determined according to the Hippocratic screening test and compared with the control group. In addition, a necropsy was performed for macroscopic evaluation of the organs in the abdominal cavity. A powder was obtained from aqueous extracts that showed the same organoleptic characteristics and emulsification capacity as those presented by the fresh root when prepared according to popular tradition. The LD50 was greater than the test dose with three animals surviving. On the other hand, necropsy of dead rats showed necrosis and reduction in lung mass, in addition to the presence of foam and excessive distension of the stomach and intestines. The main symptoms of toxicity were anesthesia, ataxia, sedation, loss of muscle strength, and excessive drowsiness in the first 24 hours. There was no difference between the control and extract groups with regard to body mass, food, and water intake, as well as in macroscopy of the heart, liver, lungs, intestines, spleen, pancreas, and kidneys. The aqueous extract of the B. floribunda was considered nontoxic or of very low toxicity. However, it is capable of altering the activity of the central nervous system and causing disorders in the respiratory and digestive systems.

Fly Me to the Micron: Microtechnologies for Drosophila Research.

Multicellular model organisms, such as Drosophila melanogaster (fruit fly), are frequently used in a myriad of biological research studies due to their biological significance and global standardization. However, traditional tools used in these studies generally require manual handling, subjective phenotyping, and bulk treatment of the organisms, resulting in laborious experimental protocols with limited accuracy. Advancements in microtechnology over the course of the last two decades have allowed researchers to develop automated, high-throughput, and multifunctional experimental tools that enable novel experimental paradigms that would not be possible otherwise. We discuss recent advances in microtechnological systems developed for small model organisms using D. melanogaster as an example. We critically analyze the state of the field by comparing the systems produced for different applications. Additionally, we suggest design guidelines, operational tips, and new research directions based on the technical and knowledge gaps in the literature. This review aims to foster interdisciplinary work by helping engineers to familiarize themselves with model organisms while presenting the most recent advances in microengineering strategies to biologists.

Nuclear factor kappa-light-chain-enhancer of activated B cells gene expression involvement in porcine liver transplant experimental model.

PURPOSE: Gene expressions of vascular Endothelial Growth Factor Alpha (VEGFa), Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B cells (NFkB) and cytokines could be useful for identifying potential therapeutic targets to alleviate ischemia-reperfusion injury after liver transplantation. Cytokine gene expressions, VEGFa and NFkB were investigated in a preclinical swine model of liver transplantation. METHODS: A total of 12 pigs were used as donors and recipients in liver transplantation without venovenous bypass or aortic clamping. NFkB, IL-6, IL-10, VEGFa and Notch1 gene expression were assessed. These samples were collected in two specific times: group 1 (n= 6) - control, samples were collected before recipient's total hepatectomy and group 2 - liver transplantation group (n=6), where the samples were collected one hour after graft reperfusion. RESULTS: Liver transplantation was successfully performed in all recipients. Liver enzymes were elevated in the transplantation group. NFkB gene expression was significantly decreased in the transplantation group in comparison with the control group (0.62±0.19 versus 0.39±0.08; p= 0.016). No difference was observed between groups Interleucine 6 (IL-6), interleucine 10 (IL-10), VEGFa and Notch homolog 1 (Notch1). CONCLUSIONS: In this survey a decreased NFkB gene expression in a porcine model of liver transplantation was observed.

Description of the Dunning-Kruger effect in general surgery residents during laparoscopic cholecystectomy: a blinded prospective study.

PURPOSE: The purpose of this study is to assess whether the Dunning-Kruger effect occurs in surgical residents when performing laparoscopic cholecystectomy in a porcine model. METHODS: Prospective blinded study, which counted with forty PGY-1 general surgery residents who agreed to participate in the study were blindly recruited to perform a laparoscopic cholecystectomy in a porcine model. At the end of the procedure, the participants assigned a score of 0-10 for their own performance and the video of the operation was independently assessed by 2 experienced laparoscopic surgeons using a validated tool. RESULTS: Participants were divided into groups of 10 individuals according to objective performance and compared. The group with the worst objective result was inferior to the group with the best objective result (3.77 ± 0.44 vs. 8.1 ± 0.44, p < 0.001), but they were similar in self-perception of performance (5.11 ± 1.69 vs. 6.1 ± 1.79, p = 0.999). CONCLUSIONS: In the studied sample, it was possible to demonstrate the presence of the Dunning-Kruger effect.

Genetic parameters of body weight traits in Mithun (Bos frontalis) using animal model.

Mithun (Bos frontalis), a domestically raised herbivore, holds significant economic importance for the farming community of Northeast India. This study aimed to elucidate the genetic parameters governing Mithun body weight traits across different ages using data from the sole organized semi-intensive Mithun farm in India. Information was gathered from 110 Mithuns born over a period spanning from 2011 to 2022. Body weight taken at week 1 (W1), 1-month (M1), 3-months (M3), 6-months (M6), 9-months (M9), 12-months (M12), 30-months (M30) and 45-months (M45) were considered for the study. The genetic parameters estimation employed the BLUPF90 suite of programs, incorporating univariate Gibbs sampler animal model with fixed effects; season and period of birth, and sex of the animal. Variance and covariance components, including direct additive genetic effects, were estimated. Heritability estimates for the eight body weight traits ranged from 0.47 ± 0.0050 to 0.50 ± 0.0043, indicating varying genetic influence across growth stages. Results revealed that Mithun herd has a substantial genetic variability for growth traits and therefore there is ample scope to select for a better growth rate. Here, we conclude that Month 12 (M12) and Month 9 (M9) body weights exhibit higher heritability, indicating potential for genetic improvement through selective breeding.

Zebrafish as a Model for Lipidomics and Similar Investigations.

Zebrafish (Danio rerio) has emerged as a pivotal model organism in vertebrate development research over several decades. Beyond its contributions to developmental biology, zebrafish have increasingly played a crucial role in the field of lipidomics. Lipidomics, a comprehensive analysis of lipids within biological systems, offers profound insights into lipid metabolism and signaling pathways. This chapter explores the zebrafish's unique attributes that make it an ideal candidate for lipidomics studies. With a genome sharing numerous genetic similarities with humans, zebrafish serve as a powerful model for dissecting lipid metabolism and unraveling the complexities of lipid mediator-related diseases. In this chapter, we delve into specific protocols tailored for utilizing zebrafish in lipidomics research and similar investigations. Through a comprehensive exploration of zebrafish as a model organism, this chapter aims to provide researchers with valuable insights and methodologies for advancing lipidomics studies using zebrafish.

Developing an Animal Model for Swenson Transanal Endorectal Pull-Through: A New Possibility for Training and Research Purposes.

As far as we know, no report uses the Swenson transanal endorectal pull-through technique in an animal model. Our objective is to describe the use of this technique as an experimental model for training and research purposes. Ten Norfolk hybrid rabbits were randomly selected from our experimental laboratory, with a mean weight of 3539.3 (± 678.4) g. Neither colon preparation nor fast were used before the procedures. The surgical technique was based on the description performed by Levitt et al. (2013, J Pediatr Surg. 2013;48(11):2289-2295). Information related to the surgical procedures and the clinical evolution in the postoperative period were recorded and analyzed. There were no deaths or severe complications. The anesthetic and the surgical times were significantly higher for the first three animals of the experiment. Our animal model proved adequate to perform the transanal endorectal Swenson pull-through technique, allowing the training of surgical skills through a model similar to the human, with few anesthetic complications and good postoperative evolution, including postoperative follow-up. We believe that it will serve as a learning tool in many institutions that are continuously searching for improved new techniques and will support new researches in this area.

Study of tree shrew biology and models: A booming and prosperous field for biomedical research.

The tree shrew ( Tupaia belangeri) has long been proposed as a suitable alternative to non-human primates (NHPs) in biomedical and laboratory research due to its close evolutionary relationship with primates. In recent years, significant advances have facilitated tree shrew studies, including the determination of the tree shrew genome, genetic manipulation using spermatogonial stem cells, viral vector-mediated gene delivery, and mapping of the tree shrew brain atlas. However, the limited availability of tree shrews globally remains a substantial challenge in the field. Additionally, determining the key questions best answered using tree shrews constitutes another difficulty. Tree shrew models have historically been used to study hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, myopia, and psychosocial stress-induced depression, with more recent studies focusing on developing animal models for infectious and neurodegenerative diseases. Despite these efforts, the impact of tree shrew models has not yet matched that of rodent or NHP models in biomedical research. This review summarizes the prominent advancements in tree shrew research and reflects on the key biological questions addressed using this model. We emphasize that intensive dedication and robust international collaboration are essential for achieving breakthroughs in tree shrew studies. The use of tree shrews as a unique resource is expected to gain considerable attention with the application of advanced techniques and the development of viable animal models, meeting the increasing demands of life science and biomedical research.

Dynamic Transcriptome Analysis of SFRP Family in Guided Bone Regeneration With Occlusive Periosteum in Swine Model.

BACKGROUND: A variety of congenital or acquired conditions can cause craniomaxillofacial bone defects, resulting in a heavy financial burden and psychological stress. Guided bone self-generation with periosteum-preserved has great potential for reconstructing large bone defects. METHODS: A swine model of guided bone regeneration with occlusive periosteum was established, the rib segment was removed, and the periosteum was sutured to form a closed regeneration chamber. Hematoxylin and eosin staining, Masson's staining, and Safranine O-Fast Green staining were done. Nine-time points were chosen for collecting the periosteum and regenerated bone tissue for gene sequencing. The expression level of each secreted frizzled-related protein (SFRP) member and the correlations among them were analyzed. RESULTS: The process of bone regeneration is almost complete 1 month after surgery, and up to 1 week after surgery is an important interval for initiating the process. The expression of each SFRP family member fluctuated greatly. The highest expression level of all members ranged from 3 days to 3 months after surgery. The expression level of SFRP2 was the highest, and the difference between 2 groups was the largest. Secreted frizzled-related protein 2 and SFRP4 showed a notable positive correlation between the control and model groups. Secreted frizzled-related protein 1, SFRP2, and SFRP4 had a significant spike in fold change at 1 month postoperatively. Secreted frizzled-related protein 1 and SFRP2 had the strongest correlation. CONCLUSIONS: This study revealed the dynamic expression of the SFRP family in guided bone regeneration with occlusive periosteum in a swine model, providing a possibility to advance the clinical application of bone defect repair.

Regrettable Substitutes and the Brain: What Animal Models and Human Studies Tell Us about the Neurodevelopmental Effects of Bisphenol, Per- and Polyfluoroalkyl Substances, and Phthalate Replacements.

In recent decades, emerging evidence has identified endocrine and neurologic health concerns related to exposure to endocrine-disrupting chemicals (EDCs), including bisphenol A (BPA), certain per- and polyfluoroalkyl compounds (PFASs), and phthalates. This has resulted in consumer pressure to remove these chemicals from the market, especially in food-contact materials and personal care products, driving their replacement with structurally or functionally similar substitutes. However, these "new-generation" chemicals may be just as or more harmful than their predecessors and some have not received adequate testing. This review discusses the research on early-life exposures to new-generation bisphenols, PFASs, and phthalates and their links to neurodevelopmental and behavioral alterations in zebrafish, rodents, and humans. As a whole, the evidence suggests that BPA alternatives, especially BPAF, and newer PFASs, such as GenX, can have significant effects on neurodevelopment. The need for further research, especially regarding phthalate replacements and bio-based alternatives, is briefly discussed.

Evaluation of a newly developed oral and maxillofacial surgical robotic platform (KD-SR-01) in head and neck surgery: a preclinical trial in porcine models.

Traditional open head and neck surgery often leaves permanent scars, significantly affecting appearance. The emergence of surgical robots has introduced a new era for minimally invasive surgery. However, the complex anatomy of the head and neck region, particularly the oral and maxillofacial areas, combined with the high costs associated with established systems such as the da Vinci, has limited the widespread adoption of surgical robots in this field. Recently, surgical robotic platform in China has developed rapidly, exemplified by the promise shown by the KangDuo Surgical Robot (KD-SR). Although the KD-SR has achieved some results comparable to the da Vinci surgical robot in urology and colorectal surgery, its performance in complex head and neck regions remains untested. This study evaluated the feasibility, effectiveness, and safety of the newly developed KD-SR-01, comparing it with standard endoscopic systems in head and neck procedures on porcine models. We performed parotidectomy, submandibular gland resection, and neck dissection, collected baseline characteristics, perioperative data, and specifically assessed cognitive workload using the NASA-TLX. None of the robotic procedures were converted to endoscopic or open surgery. The results showed no significant difference in operation time between the two groups (P = 0.126), better intraoperative bleeding control (P = 0.001), and a significant reduction in cognitive workload (P < 0.001) in the robotic group. In conclusion, the KD-SR-01 is feasible, effective, and safe for head and neck surgery. Further investigation through well-designed clinical trials with long-term follow-up is necessary to establish the full potential of this emerging robotic platform.

Methods for Tattooing Xenopus laevis with a Rotary Tattoo Machine.

Animal models expand the scope of biomedical research, furthering our understanding of developmental, molecular, and cellular biology and enabling researchers to model human disease. Recording and tracking individual animals allows researchers to reduce the number of animals required for study and refine practices to improve animal wellbeing. Several well-documented methods exist for marking and tracking mammals, including ear punching and ear tags. However, methods for marking aquatic amphibian species are limited, with the existing resources being outdated, ineffective, or prohibitively costly. In this manuscript, we outline methods and best practices for marking Xenopus laevis with a rotary tattoo machine. Proper tattooing results in high-quality tattoos, making individuals easily distinguishable for researchers and posing minimal risk to animals' health. We also highlight the causes of poor-quality tattoos, which can result in tattoos that fade quickly and cause unnecessary harm to animals. This approach allows researchers and veterinarians to mark amphibians, enabling them to track biological replicates and transgenic lines and to keep accurate records of animal health.

Surgical Implantation of Single-Staged Tissue-Engineered Urothelial Tubes in a Minipig Model.

Reconstructive surgeries are often challenged by a lack of grafting tissue. In the treatment of urogenital malformations, the conventional solution has been harvesting gastrointestinal tissue for non-orthotopic reconstruction due to its abundance to reestablish normal function in the patient. The clinical outcomes after rearranging native tissues within the body are often associated with significant morbidity; thus, tissue engineering holds specific potential within this field of surgery. Despite substantial advances, tissue-engineered scaffolds have not yet been established as a valid surgical treatment alternative, mainly due to the costly and complex requirements of materials, production, and implantation. In this protocol, we present a simple and accessible collagen-based tubular scaffold embedded with autologous organ-specific tissue particles, designed as a conduit for urinary diversion. The scaffold is constructed during the primary surgical procedure, comprises commonly available surgical materials, and requires conventional surgical skills. Secondly, the protocol describes an animal model designed to evaluate the short-term in vivo outcomes post-implantation, with the possibility of additional variations to the procedure. This publication aims to demonstrate the procedure step-by-step, with special attention to the use of autologous tissue and a tubular form.

Accessing the Porcine Brain via High-Speed Pneumatic Drill Craniectomy.

The use of pigs as an experimental animal model is especially relevant in neuroscience research, as the porcine and human central nervous systems (CNS) share many important functional and architectural properties. Consequently, pigs are expected to have an increasingly important role in future research on various neurological diseases. Here, a method to perform an anterior craniectomy through the porcine frontal bone is described. After a midline incision and subsequent exposure of the porcine frontal bone, anatomical landmarks are used to ensure the optimal location of the craniectomy. By careful and gradual thinning of the frontal bone with a rounded drill, a rectangular opening to the dura mater and underlying cerebral hemispheres is achieved. The presented method requires certain surgical materials, including a pneumatic high-speed drill, and some degree of surgical experience. Potential complications include unintended lesions of the dura mater or dorsal sagittal sinus. However, the method is simple, time-efficient, and offers a high degree of reproducibility for researchers. If performed correctly, the technique exposes a large portion of the unaffected pig brain for various neuromonitoring or analyses.

Mouse Models in Circadian Rhythm and Melatonin Research.

This contribution reviews the role of inbred and transgenic mouse strains for deciphering the mammalian melatoninergic and circadian system. It focusses on the pineal organ as melatonin factory and two major targets of the melatoninergic system, the suprachiasmatic nuclei (SCN) and the hypophysial pars tuberalis (PT). Mammalian pinealocytes sharing molecular characteristics with true pineal and retinal photoreceptors synthesize and secrete melatonin into the blood and cerebrospinal fluid night by night. Notably, neuron-like connections exist between the deep pinealocytes and the habenular/pretectal region suggesting direct pineal-brain communication. Control of melatonin biosynthesis in rodents involves transcriptional regulation including phosphorylation of CREB and upregulation of mPer1. In the SCN, melatonin acts upon MT1 and MT2 receptors. Melatonin is not necessary to maintain the rhythm of the SCN molecular clockwork, but it has distinct effects on the synchronization of the circadian rhythm by light, facilitates re-entrainment of the circadian system to phase advances in the level of the SCN molecular clockwork by acting upon MT2 receptors and plays a stabilizing role in the circadian system as evidenced from locomotor activity recordings. While the effects in the SCN are subtle, melatonin is essential for PT functions. Via the MT1 receptor it drives the PT-intrinsic molecular clockwork and the retrograde and anterograde output pathways controlling seasonal rhythmicity. Although inbred and transgenic mice do not show seasonal reproduction, the pathways from the PT are fully intact if the animals are melatonin proficient. Thus, only melatonin-proficient strains are suited to investigate the circadian and melatoninergic systems.

Impact of graft width and chondrolabral junction preservation on labral suction seal integrity in bovine hip models.

OBJECTIVE: This study investigates the biomechanical effects of graft width and chondrolabral junction (CLJ) preservation on the labral suction seal in a bovine hip model and aims to validate this model as a practical alternative for hip biomechanical research by comparing it with human cadaver studies. MATERIALS AND METHODS: Twenty hips from two-year-old male bovines were divided into two main groups: CLJ preserved (CLJ+) and CLJ excised (CLJ-). These groups were further divided into eight subgroups: Group 1 with an intact labrum; Group 2 with labrum excision preserving CLJ; Groups 3 and 4 with labral reconstruction on preserved CLJ using 4.5 mm and 9 mm grafts, respectively; Group 5 with a labral tear at 12 to 3 o'clock position without CLJ preservation; Group 6 with complete labrum excision without CLJ preservation; and Groups 7 and 8 with labral reconstruction on excised CLJ using 4.5 mm and 9 mm grafts. Mechanical tests measuring compression and distraction forces were conducted, recording force-displacement values. RESULTS: Both CLJ+ and CLJ- groups showed that labrum excision resulted in the lowest distraction forces, emphasizing labral integrity. Notably, reconstruction with 9 mm grafts improved distraction forces more than 4.5 mm grafts (p<0.001). The change in distraction forces from intact to excised stages was nearly significant between CLJ+ and CLJ- groups (Δ Intact-excised: CLJ+ vs. CLJ-: 92 N vs. 105 N, p=0.08). Distraction forces were measured at 206±27 Newtons in the CLJ preserved group and 186±24 Newtons in the resected group. CONCLUSIONS: This study demonstrates that increasing the width of the graft, despite being approximately half and a quarter of the native labrum's size, significantly enhances the distraction force in labral reconstruction within a bovine hip model. This improvement is more pronounced than the effects of preserving the CLJ, highlighting the critical role of graft size in maintaining the biomechanical integrity of the labral suction seal.

[Mechanisms of the Effect of Maternal Age-Related Oocyte Aging on Fertility: Transcriptomic Sequencing Analysis of a Zebrafish Model]. / æ¯ä½“å¹´é¾„ç›¸å ³çš„åµæ¯ç»†èƒžè€åŒ–å¯¹ç”Ÿè‚²åŠ›çš„å½±å“æœºåˆ¶ï¼šæ–‘é©¬é±¼æ¨¡åž‹çš„è½¬å½•ç»„å­¦æµ‹åºåˆ†æž.

Objective: Female fertility gradually decreases with the increase in women's age. The underlying reasons include the decline in the quantity and quality of oocytes. Oocyte aging is an important manifestation of the decline in oocyte quality, including in vivo oocyte aging before ovulation and in vitro oocyte aging after ovulation. Currently, few studies have been done to examine oocyte aging, and the relevant molecular mechanisms are not fully understood. Therefore, we used zebrafish as a model to investigate oocyte aging. Three different age ranges of female zebrafish were selected to mate with male zebrafish of the best breeding age. In this way, we studied the effects of maternal age-related oocyte aging on fertility and investigated the potential molecular mechanisms behind maternal age-related fertility decline. Methods: Eight female zebrafish aged between 158 and 195 d were randomly selected for the 6-month age group (180±12) d, 8 female zebrafish aged between 330 and 395 d were randomly selected for the 12-month age group (360±22) d, and 8 female zebrafish aged between 502 and 583 d were randomly selected for the 18-month age group (540±26) d. Male zebrafish of (180±29) d were randomly selected from zebrafish aged between 158 and 195 d and mated with female zebrafish in each group. Each mating experiment included 1 female zebrafish and 1 male zebrafish. Zebrafish embryos produced by the mating experiments were collected and counted. The embryos at 4 hours post-fertilization were observed under the microscope, the total number of embryos and the number of unfertilized embryos were counted, and the fertilization rate was calculated accordingly. The numbers of malformed embryos and dead embryos were counted 24 hours after fertilization, and the rates of embryo malformation and mortality were calculated accordingly. The primary outcome measure was the embryo fertilization rate, and the secondary outcome measures were the number of embryos per spawn (the total number of embryos laid within 1.5 hours after the beginning of mating and reproduction of the zebrafish), embryo mortality, and embryo malformation rate. The outcome measures of each group were compared. The blastocyst embryos of female zebrafish from each group born after mating with male zebrafish in their best breeding period were collected for transcriptomics analysis. Fresh oocytes of female zebrafish in each group were collected for transcriptomics analysis to explore the potential molecular mechanisms of maternal age-related fertility decline. Results: Compared with that of the 6-month group (94.9%±3.6%), the embryo fertilization rate of the 12-month group (92.3%±4.2%) showed no significant difference, but that of the 18-month group (86.8%±5.5%) decreased significantly (P<0.01). In addition, the fertilization rate in the 18-month group was significantly lower than that in the 12-month group (P<0.05). Compared with that of the 6-month group, the embryo mortality of the female zebrafish in the 12-month group and that in the 18-month group were significantly higher than that in the 6-month group (P<0.000 1, P<0.001). There was no significant difference in the number of embryos per spawn or in the embryo malformation rate among the three groups. The results of the transcriptomics analysis of blastocyst embryos showed that some genes, including dusp5, bdnf, ppip5k2, dgkg, aldh3a2a, acsl1a, hal, mao, etc, were differentially expressed in the 12-month group or the 18-month group compared with their expression levels in the 6-month group. According to the KEGG enrichment analysis, these differentially expressed genes (DEGs) were significantly enriched in the MAPK signaling pathway, the phosphatidylinositol signaling system, and the fatty acid degradation and histidine metabolism pathway (P<0.05). The analysis of the expression trends of the genes expressed differentially among the three groups (the 6-month group, the 12-month group, and the 18-month group in turn) showed that the gene expression trends of fancc, fancg, fancb, and telo2, which were involved in Fanconi anemia pathway, were statistically significant (P<0.05). In the results of oocyte transcriptomics analysis, the genes that were differentially expressed in the 12-month group or the 18-month group compared with the 6-month group were mainly enriched in cell adhesion molecules and the protein digestion and absorption pathway (P<0.05). The results of the trends of gene expression in the zebrafish oocytes of the three groups (the 6-month group, the 12-month group, and the 18-month group in turn) showed that three kinds of gene expression trends of declining fertility with growing maternal age had significant differences (P<0.05). Further analysis of the three significantly differential expression trends showed 51 DEGs related to mitochondria and 5 DEGs related to telomere maintenance and DNA repair, including tomm40, mpc2, nbn, tti1, etc. Conclusion: With the increase in the maternal age of the zebrafish, the embryo fertilization rate decreased significantly and the embryo mortality increased significantly. In addition, with the increase in the maternal age of the zebrafish, the expression of mitochondria and telomere-related genes, such as tomm40, mpc2, nbn, and tti1, in female zebrafish oocytes decreased gradually. Maternal age may be a factor contributing to the decrease in oocyte fertilization ability and the increase in early embryo mortality. Maternal age-related oocyte aging affects the fertility and embryo development of the offspring.

Still to ARRIVE at adequate reporting of orthodontic studies involving animal models.

BACKGROUND: The ARRIVE 2.0 guidelines were introduced to improve the reporting of animal studies. The aim of this study was to assess the reporting adherence of orthodontic speciality animal studies in relation to ARRIVE 2.0 guidelines. Associations between the reporting and study characteristics were explored. MATERIALS AND METHOD: An electronic database search was undertaken using Medline via PubMed (www.pubmed.ncbi.nlm.nih.gov) to identify studies meeting the eligibility criteria published between 1 January 2018 and 31 December 2023. Data extraction was performed in duplicate and independently. Descriptive statistics and frequency distributions for the responses to each checklist item were calculated. Mean values for adequate reporting per ARRIVE item were calculated. A sum score was calculated by adding the responses (0 = not reported, 1 = inadequate reporting, 2 = adequate reporting) per item and sub-questions. On an exploratory basis, univariable linear regression between summary score and study characteristics (year of publication, continent of authorship, type of centre, and number of authors) was performed. RESULTS: Three hundred and eighty-four studies were analysed. Variability in the adequate reporting of the ARRIVE 2.0 guideline items was evident. In particular, in 32% of studies, there was a lack of reporting of the priori sample size calculation. Overall, the mean reporting score for the sample was 57.9 (SD 6.7 and range 34-74). There were no associations between score and study characteristics except for a weak association for year of publication with a small improvement over time (each additional year). CONCLUSIONS: The reporting of animal studies relevant to the speciality of orthodontics is sub-optimal in relation to the ARRIVE 2.0 guidelines. There was a tendency for the non-reporting of items pertaining to study sample size, eligibility, methods to reduce bias and interpretation/scientific implications. Greater awareness and reporting adherence to the ARRIVE 2.0 guidelines are required to reduce research waste involving animal models.

Determination of Cardiac Output in a Porcine Model for Ex Vivo Pulmonary Perfusion.

Due to their physiological similarities to humans, pigs are used as experimental models for ex vivo lung perfusion (EVLP). EVLP is a technique that perfuses lungs that are not suitable for transplantation via an extracorporeal circulation pump to improve their function and increase their viability. Existing EVLP protocols are differentiated by the type of perfusion solution and perfusion flow, which varies from 40%-100% of the estimated cardiac output (CO) according to the body surface area (BSA). Devices for measuring CO use simple physical principles and other mathematical models. Thermodilution in animal models continues to be the reference standard for estimating CO because of its simplicity and ease of reproduction. Therefore, the objective of this study was to reproduce the measurement of CO by thermodilution in pigs and compare its precision and accuracy with those obtained by the BSA, weight, and Fick's method, to establish perfusion flow during EVLP. In 23 pigs, a thermodilution catheter was placed in the right jugular vein, and the carotid artery on the same side was cannulated. Blood samples were obtained for gasometry, and CO was estimated by thermodilution, adjusted body surface area, Fick's principle, and per body weight. The CO obtained by the BSA was greater (p = 0.0001, ANOVA, Tukey) than that obtained by the other methods. We conclude that although the methods used in this study to estimate CO are reliable, there are significant differences between them; therefore, each method must be evaluated by the investigator to determine which meets the needs of the protocol.