Laboratory Animal Research最新文献

Rabbits are being increasingly used as companion animals, and in research; thus, the need for proper veterinary care for rabbits has increased. Surgical access is more challenging in rabbits under inhalation anesthesia compared to other animals, such as dogs and cats. Rabbits have a very narrow and deep oral cavity, large incisors, and a large tongue. Moreover, their temporomandibular joint has limited mobility, making it more difficult to approach the larynx. Various methods have been proposed to overcome this difficulty. The video laryngoscope was introduced in 1999 and is useful when airway intubation is unsuccessful using a conventional laryngoscope. We postulated that a video laryngoscope with a modified size 1 Macintosh blade (McGrath MAC Video Laryngoscope, Medtronic, USA) would facilitate the intubation of New Zealand White rabbits. Sixteen specific-pathogen-free male New Zealand White rabbits weighing 3.45-4.70 kg were studied. All rabbits were intubated using the video laryngoscope. Typically, a 3.0 mm endotracheal tube was used for rabbits weighing < 4 kg, while a 3.5 mm tube was used in those weighing > 4 kg. During surgery, anesthesia was well maintained, and there were no major abnormalities in the animals' conditions. No rabbit developed breathing difficulties or anorexia after recovering from anesthesia. We established an intubation method using a video laryngoscope with a modified blade and stylet in the supine (ventrodorsal) position and successfully applied it in 16 rabbits. It is useful for training novices and for treating rabbits in veterinary hospitals with few staff members and animal research facilities where there are insufficient human resources.

Background: Mechanical ventilation is a life-saving therapy for critically ill patients, providing rest to the respiratory muscles and facilitating gas exchange in the lungs. Ventilator-induced lung injury (VILI) is an unfortunate side effect of mechanical ventilation that may lead to serious consequences for the patient and increase mortality. The four main injury mechanisms associated with VILI are: baro/volutrauma caused by overstretching the lung tissues; atelectrauma, caused by repeated opening and closing of the alveoli resulting in shear stress; oxygen toxicity due to use of high ratio of oxygen in inspired air, causing formation of free radicals; and biotrauma, the resulting biological response to tissue injury, that leads to a cascade of events due to excessive inflammatory reactions and may cause multi-organ failure. An often-overlooked part of the inflammatory reaction is oxidative stress. In this research, a mouse model of VILI was set up with three tidal volume settings (10, 20 and 30 mL/kg) at atmospheric oxygen level. Airway pressures and heart rate were monitored and bronchoalveolar lavage fluid (BALF) and lung tissue samples were taken.

Results: We show a correlation between increased inflammation and barrier failure, and higher tidal volumes, evidenced by increased IL-6 expression, high concentration of proteins in BALF along with changes in expression of adhesion molecules. Furthermore, swelling of mitochondria in alveolar type II cells was seen indicating their dysfunction and senescence-like state. RNA sequencing data present clear increases in inflammation, mitochondrial biogenesis and oxidative stress as tidal volume is increased, supported by degradation of Keap1, a redox-regulated substrate adaptor protein.

Conclusions: Oxidative stress seems to be a more prominent mechanism of VILI than previously considered, indicating that possible treatment methods against VILI might be identified by impeding oxidative pathways.

To systematically evaluate the effects of metformin on tumors in experimental animal models of different types of cancer. Pubmed, Embase, Cochrane, and Web of Science databases were searched for studies on metformin used in various experimental animal tumor models from 2008 to 2022. Meta-analysis was performed using STATA 16.0 software after screening literature extraction data and methodological quality evaluation by inclusion and exclusion criteria. A total of 24 studies with 1108 model animals were included. Meta-analysis results showed that this study used meta-analysis for quantitative synthesis of study results and found that tumor model animals of different species showed different degrees of reduction in tumor volume, weight, and number after metformin intervention.

Background: Neuroinflammation plays an important role in cognitive decline and memory impairment in neurodegenerative disorders. Previously, we demonstrated that Humulus japonicus (HJ) has anti-inflammatory effects in rodent models of Alzheimer's disease and Parkinson's disease. The present study aimed to examine the protective potential of HJ extracts against lipopolysaccharide (LPS)-induced cognitive impairment and scopolamine-induced amnesia in mouse models. Cognitive improvement of mice was investigated by novel object recognition test. For analyzing effects on neuroinflammation, immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR) assays were performed.

Results: We found that the oral administration of HJ significantly improved cognitive dysfunction induced by LPS in a novel object recognition test. The LPS-induced activation of microglia was notably decreased by HJ treatment in the cortex and hippocampus. HJ administration with LPS also significantly increased the mRNA expression of interleukin (IL)-10 and decreased the mRNA expression of IL-12 in the parietal cortex of mice. The increased expression of LPS-induced complement C1q B chain (C1bq) and triggering receptor expressed on myeloid cells 2 (Trem2) genes was significantly suppressed by HJ treatment. In addition, HJ administration significantly improved novel object recognition in a scopolamine-induced amnesia mouse model.

Conclusions: These findings revealed that HJ has a beneficial effect on cognitive impairment and neuroinflammation induced by systemic inflammation and on amnesia induced by scopolamine in mice.

Background: Gastrointestinal microbiota, which comprises hundreds of different types of microbes, biologically plays crucial roles in the host's health. Probiotics (PRO) did not always have a positive benefit on the host, depending on strains of microbes and the physiochemical properties of prebiotics (PRE), indicating that the properties of PRE in combination with PRO might have different effects on the gut ecology. The aim of this study was to assess the effects of insoluble or soluble PRE with PRO on intestinal digestive hydrolase, the fecal microbes, and immunological biomarkers in SD rats fed an AIN-93G diet.

Results: Forty, 8-week-old SD rats were randomly assigned to 4 groups with 10 replicates in each; cellulose (CELL), cellulose + probiotics (CELPRO), oatmeal (OATS), and oatmeal + probiotics (OATPRO) groups. After 4-week feeding trial, rats were treated with saline or lipopolysaccharide (LPS, 1 mg/kg) to examine the alleviating effects of PRO and PRE on immunological responses. There was a significant (p < 0.05) decrease in feed intake of rats fed the oatmeal supplemented diet without affecting growth performance. Blood triglyceride was significantly (p < 0.05) decreased in rats fed the oatmeal diet, and aspartate aminotransferase (AST) was significantly (p < 0.05) decreased in rats fed the PRO supplemented diet. Intestinal maltase, sucrose, and lactase activities were significantly (p < 0.05) higher in rats fed PRO compared with rats not fed PRO. Rats fed the oatmeal showed a significant (p < 0.01) increase in the fecal colony forming units (CFU) of Lactobacillus plantarum, Bacillus subtilis, and Saccharomyces cerevisiae compared with those fed cellulose. LPS-treated rats fed PRO showed a significant (p < 0.05) increase in blood secretory immunoglobulin A (sIgA) compared with those not fed PRO. The LPS-treated rats fed PRO resulted in decreased (p < 0.05) blood IL-6 compared with those not fed PRO, indicating that a dietary PRO alleviated inflammatory response in LPS-treated rats.

Conclusions: Dietary oatmeal increased fecal microbes, and PRO supplement resulted in increased intestinal hydrolase and immune functions of the host, demonstrating that soluble PRE with supplemented with PRO could be a more bioactive combination of synbiotics in SD rats.

Animals are studied en masse by biologists around the world in a variety of biomedical and basic research studies. All this research benefits humankind and animals alike as it tackles a wide variety of problems ranging from those of conservation biology to medicine. Research with animal subjects is a complex endeavor that requires the cooperation and collaboration of a large number of experts, from the principal investigator through technicians and vivarium staff to regulatory experts. The research must be conducted in a humane manner that adheres to acceptable practices regulated by local, state and federal guidelines, rules and the law. In this short opinion article, we examine the current state of affairs regarding how researchers, animal support staff and regulatory experts work together. We pay particular attention to potential conflicts that may arise from the occasionally distinct roles played by those involved in animal research, and we provide some suggestions as short- and long-term remedies that have not been previously discussed in the literature.

The animal model deals with the species other than the human, as it can imitate the disease progression, its' diagnosis as well as a treatment similar to human. Discovery of a drug and/or component, equipment, their toxicological studies, dose, side effects are in vivo studied for future use in humans considering its' ethical issues. Here lies the importance of the animal model for its enormous use in biomedical research. Animal models have many facets that mimic various disease conditions in humans like systemic autoimmune diseases, rheumatoid arthritis, epilepsy, Alzheimer's disease, cardiovascular diseases, Atherosclerosis, diabetes, etc., and many more. Besides, the model has tremendous importance in drug development, development of medical devices, tissue engineering, wound healing, and bone and cartilage regeneration studies, as a model in vascular surgeries as well as the model for vertebral disc regeneration surgery. Though, all the models have some advantages as well as challenges, but, present review has emphasized the importance of various small and large animal models in pharmaceutical drug development, transgenic animal models, models for medical device developments, studies for various human diseases, bone and cartilage regeneration model, diabetic and burn wound model as well as surgical models like vascular surgeries and surgeries for intervertebral disc degeneration considering all the ethical issues of that specific animal model. Despite, the process of using the animal model has facilitated researchers to carry out the researches that would have been impossible to accomplish in human considering the ethical prohibitions.

Background: As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research.

Results: In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research.

Conclusions: This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.

Background: Transcranial direct current stimulation (tDCS) has been studied as a tool to stimulate the functional recovery of neurons after stroke. Although this device has recently begun to be utilized for providing neuroprotection in stroke, research on its application conditions is lacking. This study aimed to examine the effects of various tDCS application conditions on cerebral ischemia. Ischemia was induced for 5 min in a gerbil model. The application of tDCS comprised a 20 min stimulation-20 min rest-20 min stimulation protocol, which was implemented simultaneously with the induction of cerebral ischemia. Application time of the tDCS effect on ischemia was confirmed by sampling brain tissues after stimulation using 0.2 mA tDCS at 0, 5, 10 and 60 min after ischemia.

Results: Persistence of the tDCS effect on ischemia was confirmed by sampling brain tissues 5, 7, and 10 days post stimulation, with 0.2 mA tDCS after ischemia. Furthermore, the tissues were stained with cresyl violet and Fluoro-Jade C so as to determine the reduction in neuronal death under all application conditions.

Conclusions: The application of tDCS can be used as a useful intervention for acute phase stroke due to its sustained neuroprotective effect.