Preclinical Experimental Research Research Articles

Patient-derived tumor models: a suitable tool for preclinical studies on esophageal cancer.

Esophageal cancer (EC) is the tenth most common cancer worldwide and has high morbidity and mortality. Its main subtypes include esophageal squamous cell carcinoma and esophageal adenocarcinoma, which are usually diagnosed during their advanced stages. The biological defects and inability of preclinical models to summarize completely the etiology of multiple factors, the complexity of the tumor microenvironment, and the genetic heterogeneity of tumors severely limit the clinical treatment of EC. Patient-derived models of EC not only retain the tissue structure, cell morphology, and differentiation characteristics of the original tumor, they also retain tumor heterogeneity. Therefore, compared with other preclinical models, they can better predict the efficacy of candidate drugs, explore novel biomarkers, combine with clinical trials, and effectively improve patient prognosis. This review discusses the methods and animals used to establish patient-derived models and genetically engineered mouse models, especially patient-derived xenograft models. It also discusses their advantages, applications, and limitations as preclinical experimental research tools to provide an important reference for the precise personalized treatment of EC and improve the prognosis of patients.

The standards of reporting trials in pets (PetSORT): Explanation and elaboration.

Well-designed randomized controlled trials (RCTs) provide the best evidence of the primary research designs for evaluating the effectiveness of interventions. However, if RCTs are incompletely reported, the methodological rigor with which they were conducted cannot be reliably evaluated and it may not be possible to replicate the intervention. Missing information also may limit the reader's ability to evaluate the external validity of a trial. Reporting guidelines are available for clinical trials in human healthcare (CONSORT), livestock populations (REFLECT), and preclinical experimental research involving animals (ARRIVE 2.0). The PetSORT guidelines complement these existing guidelines, providing recommendations for reporting controlled trials in pet dogs and cats. The rationale and scientific background are explained for each of the 25 items in the PetSORT reporting recommendations checklist, with examples from well-reported trials.

A Study to Assess the Quality of Reporting of Animal Research Studies Published in PubMed Indexed Journals: A Retrospective, Cross-Sectional Content Analysis.

Objectives: A complete and concise pre-clinical experimental research gives detailed information about the disease-specific model, prevents duplication, and saves animal life, money, as well as time. It will also allow readers to effectively interpret and evaluate the work and ensure that others can replicate the experiments described. The present study was conducted to assess the adequacy of animal details provided in published experimental animal studies.Methods: All in vivo studies published as full-text articles in two PubMed indexed journals (one Indian and one international) from January 2011 to December 2019 and satisfying the inclusion norms were included. A checklist consisting of 27 discrete items subdivided under three domains, viz. animal details, disease model, and guidelines, was used. Every article was assessed by two investigators independently for determining the reporting quality.Results: One hundred and seventy-seven studies satisfied the inclusion criteria. Age or age range was reported in 20.34% of the articles in the Indian journal and 5.88% articles in the international journal (p=0.019). Housing and husbandry details were reported in all the articles published in the international journal and 82.7% of the articles in the Indian journal (p=0.001). The disease/pathology studied was given in 70.62% of articles published in the Indian journal and 86.27% of articles published in the international journal (p=0.029). None of the studies provided details of genetic modification, health status, sample size calculation, steps taken to minimize bias, and implementation of randomization.Conclusion: There is a need for optimal reporting of certain relevant animal details, disease models, experimental procedures, sample size calculation, and adherence to guidelines by the researchers for which the reporting was found to be sub-par to improve reproducibility and validity of animal research.

Registration of health and medical research

Registration of health and medical research is an effective way of improving the transparency and credibility of evidence. Registration involves pre-specifying the research objectives, design, methods and analytic plan on...

Analysis of the functioning of the educational and research laboratory “Pharmadar” in the context of the preparation of a Ph.D. on the example of the pedagogical load of the cycle of choice “Preclinical experimental research”

The cycle of choice “Preclinical experimental research” is an integral component of the compulsory discipline “Pharmacology”. Successful pedagogical training of scientific personnel (graduate students) became possible thanks to the development of the curriculum, which, first of all, became possible thanks to the efforts of the scientific personnel of the Pharmadar Educational and Research Laboratory. They provide not only the functioning of the cycle, but also carry out the scientific and practical burden of fulfilling the tasks of scientific research and economic calculation programs. The composition of the mandatory documentation of pedagogical (educational) work, on which the training of graduate students studying the cycle “Preclinical Experimental Research” is carried out, includes: a practical training program for applicants for the degree of candidate of medical sciences in the specialty 14.03.05 – “pharmacology”; the provision on attaching to the Department of Pharmacology approved by the Academic Council in order to master the mandatory program “222 – medicine, pharmacology”; thematic and calendar plans; independent work; list of additional literature; guidelines The laboratory staff, with the help of graduate students and doctoral students, have developed, improved and patented a number of methods for providing preclinical studies. Thus, the functioning of an educational research laboratory creates an optimal and rational scientific and practical basis for the preparation of a Ph.D. by mastering a post-graduate cycle of choice “Preclinical experimental research”, which was shown by the example of the functioning of the laboratory. In the future, it is appropriate and promising to develop a curriculum for English-speaking students, given the constant increase in their number among university entrants, and as a result — increase in the proportion of foreign citizens, among graduates and entering postgraduate study.

Alterations of field potentials in isotropic cardiomyocyte cell layers induced by multiple endogenous pacemakers under normal and hypothermal conditions.

The use of autonomous contracting randomly grown cardiomyocyte monolayers cultivated on microelectrode arrays (MEAs) represents an accepted experimental setting for preclinical experimental research in the field of cardiac electrophysiology. A dominant pacemaker forces a monolayer to adhere to a regular and synchronized contraction. Randomly distributed multiple pacemakers interfere with this dominant center, resulting in more or less frequent changes of propagation direction. This study aims to characterize the impact of changing propagation directions at single electrodes of the MEA on the four intrinsic parameters of registered field potentials (FPs) FPrise, FPMIN, FPpre, and FPdur and conduction velocity (CV) under normal and hypothermal conditions. Primary cultures of chicken cardiomyocytes (n = 18) were plated directly onto MEAs and FPs were recorded in a temperature range between 37 and 29°C. The number and spatiotemporal distribution of biological and artificial pacemakers of each cell layer inside and outside of the MEA registration area were evaluated using an algorithm developed in-house. In almost every second myocardial cell layer, interfering autonomous pacemakers were detected at stable temperatures, showing random spatial distributions with similar beating rates. Additionally, a temperature-dependent change of the dominant pacemaker center was observed in n = 16 experiments. A significant spread-direction-dependent variation of CV, FPrise, FPMIN, and FPpre up to 14% could be measured between different endogenous pacemakers. In conclusion, based on our results, disregarding the spatial origin of excitation may lead to misinterpretations and erroneous conclusions of FP parameters in the verification of research hypotheses in cellular electrocardiology.

The experimental study of the specific pharmacological action of «Artproment» combined gel

The preclinical experimental research concerning the study of the specific pharmacological action of "ArtpromentÒ" gel has been done. The gel developed contains propolis phenolic hydrophobic drug, articaine hydrochloride, menthol and rosemary oil in its composition. The medicine is planned to application in sports medicine with the purpose of treating traumatic injuries of organs of the locomotor apparatus accompanied with sport traumas (bruises, dislocations, sprains, ruptures of ligaments, tendons, etc.).In this work the pharmacological, physiological, instrumental methods of research and methods of mathematical statistics have been used.The study of the analgesic and local anesthetic action of the gel developed was conducted at the premises of the Central Research Laboratory of NUPh under the supervision of Doctor of Pharmacy, professor L.V.Iakovlieva on the model of tail thermoirritation in white rats weighing 180.0-200.0 g. The analgesic and local anesthetic actions were estimated by the ability of the medicine studied to change the pain threshold (duration of the latent period, sеc.) in animals of the test group comparing to the control group in the dose of 25 mg/cm2 and the base in the dose of 30 mg/cm2 after application to the tail.The results of the experiment testify that when studying the influence of the combined gel on the course of the experimental nociceptive response of the central origin the significant analgesic action of "ArtpromentÒ" medicine has been determined; its highest intensity was observed in 2.5 and 3.5 hours after application and is 52 % and 59 %, respectively. Despite the fact that the progress of the pain syndrome in the model of tail thermoirritation is mediated by the central nervous system, it is possible to conclude that the developed gel has an expressed analgesic and local anesthetic action. The medicine shows the significant anti-edema action at the level of the reference medicine "Diclofen-gel" on the carrageenan-induced paw oedema model.Taking into account that injuries of organs of the locomotor apparatus cause manifestation of inflammation and development of oedema it is expedient to study the anti-edema action of "ArtpromentÒ" gel in comparison with "Diclofen-gel", which is the complete analogue by the specific pharmacological action and the partial analogue by the composition. The research was conducted using the carrageenan-induced paw edema model in 24 rats weighing 180.0-200.0 g. Edema was caused by subplantar introduction of 0.1 ml of 1 % solution of carrageenin into one of the hind limbs of the animals of the test and control groups. Development of oedema was registered by increase of the paw’s volume measured in dynamics in 1; 2; 3; 4 і 5 hours with the help of a mechanical oncometer according to A.S. Zakharevsky.The experimental results indicated that the medicine under research exhibits a significant anti-edema action on the level of the reference medicine "Diclofen-gel". It has been experimentally found that the average anti-edema action of the "ArtpromentÒ" gel within 5 hours is 39 %, "Diclofen-gel" – 48 %; it is the evidence of their similarity in the absence of confidence in the index divergence. Therefore, the developed medicine shows the expressed anti-edema action at the level of 40-50 %, this property together with the analgesic and local anesthetic activities allows to recommend it for further study with the purpose of creation of the local medicine for traumatic injuries of the locomotor system treating accompanied with sports traumas (bruises, dislocations, sprains, ruptures of ligaments, tendons, etc.).

A New, Straightforward Ex Vivo Organoid Bladder Mucosal Model for Preclinical Research

We developed an experimental ex vivo organoid bladder mucosal model that can be used for experimental research purposes to create alternatives to current animal models. We developed an ex vivo organoid bladder mucosal model by immobilizing a type I collagen scaffold on the bottom of a Transwell® insert, creating a 2-compartment system. Mucosal biopsies from porcine bladders were placed on top of the scaffold and cultured in different mediums. We evaluated the morphological aspects of biopsy tissue. Cultured samples were assessed by scanning electron microscopy, and immunohistochemical and histochemical staining for cell identification, proliferation and morphology. Cells remained viable in Dulbecco's modified Eagle's medium/F-12 and smooth muscle cell medium for up to 3 weeks. The mucosa retained normal morphological characteristics for up to 1 week. Cells (mostly urothelial cells) proliferated and fully covered the scaffold surface within 3 weeks. We developed an experimental ex vivo organoid model of bladder mucosa for preclinical experimental research. This model could be used for high volume screening for pharmacology and toxicology experiments. It has the potential to replace currently used animal models.

Natalizumab therapy for multiple sclerosis.

The treatment of relapsing remitting multiple sclerosis has witnessed major progress since the first effective disease modifying treatment, ß-interferon, became available in 1993. One of the most remarkable new treatments has been natalizumab. This review describes the evolution of this humanized anti-α4ß1 monoclonal antibody, from preclinical experimental research through proof-of-concept (phase 1/2) and pivotal (phase 3) clinical trials to the now extensive experience of its use in clinical practice. The future potential and challenges of natalizumab and oral therapies with a similar mechanism of action are also discussed.

Wound repair and anti-inflammatory potential of essential oils from cones of Pinaceae: Preclinical experimental research in animal models

Ethnopharmacological relevanceEthnobotanical surveys revealed that Abies bornmulleriana, Abies cilicica, Abies nordmanniana and Cedrus libani have been used to promote wound healing in Turkish folk medicine. Four different fir species (Abies cilicica subsp. cilicica, Abies nordmanniana subsp. bornmulleriana, Abies nordmanniana subsp. equi-trojani, and Abies nordmanniana subsp. nordmanniana), Cedrus libani and Picea orientalis were assessed for their in vivo wound healing and anti-inflammatory activities. Materials and methodsThe essential oils from six different coniferous cones were used. In vivo wound healing activity of the plants was evaluated by linear incision and circular excision experimental wound models subsequently histopathological analysis. The healing potential was comparatively assessed with a reference ointment Madecassol®, which contains 1% extract of Centella asiatica. Additionally acetic acid-induced capillary permeability test was used for the oils’ anti-inflammatory activity. ResultsThe essential oils from Cedrus libani and Abies cilicica subsp. cilicica demonstrated the highest activities on the both wound models. Moreover, the oil from Abies nordmanniana subsp. bornmulleriana was found generally highly effective. On the other hand, the rest of the species did not show any remarkable wound healing effect. Results of the present study support the continued and expanded utilization of these plant species employed in Turkish folk medicine. ConclusionThe experimental study revealed that Cedrus libani and Abies cilicica subsp. cilicica display remarkable wound healing and anti-inflammatory activities.

Liver Transplantation in the Rat: Single-Center Experience With Technique, Long-term Survival, and Functional and Histologic Findings

Orthotopic liver transplantation (OLT) in rats is frequently used as an experimental model. Numerous surgical techniques have been developed that enable the investigator to conduct clinically relevant studies. The objective of this study was to develop a rat model of acute and chronic rejection, to explicitly study technical modifications of vascular anastomoses with precision, and to examine histopathologic and functional changes in the graft. With DA-(RT1av1) rats as donors and Lewis-(RT1) rats as recipients, arterialized OLT was performed using a combined suture, cuff, and splint method. Recipients were divided into 5 groups: syngeneic control rats (group 1), allogeneic control rats (group 2), allogeneic OLT rats with low-dose tacrolimus (FK506) immunosuppression (group 3), allogeneic OLT rats with high-dose tacrolimus immunosuppression (group 4), and allogeneic OLT rats with high-dose tacrolimus immunosuppression and retrograde reperfusion via the infrahepatic caval vein (group 5). After OLT, serum parameters were determined and hepatic biopsy specimens were sampled. We examined the effects of acute rejection with or without immunosuppression therapy at histopathologic evaluation. Liver grafts in syngeneic and allogeneic rats (groups 1, 2, 4, and 5) demonstrated normal serum parameters and histopathologic findings at 10 days after OLT, and 93% survival at 3 months. The simplified technique using 1 suture and 2 cuff anastomoses provided the best short- and long-term survival after OLT in all groups. Retrograde perfusion via the infrahepatic caval vein resulted in lower postoperative liver enzyme values. The present model is feasible, enabling comprehensive preclinical experimental research on liver transplantation. Furthermore, we provide helpful instructions for learning this surgical technique.

The Establishment of a New En Bloc Combined Liver-Small Bowel Transplantation Model in Rats

In order to facilitate preclinical research, we established a new combined liver-small bowel transplantation rat model. Male inbred Wistar rats were chosen as donors and recipients. An en bloc liver-small bowel graft was harvested. During the donor operation, the inferior vena cava in the chest was removed to be used as an interpositional venous graft to anastomose to the portal vein. In the recipient operation the portal veins of donor and recipient were quickly anastomosed using a cuff technique instead of the traditional suture method. Rearterialization was achieved by anastomosing the superior mesenteric artery of graft to the right renal artery of the recipient. The recipient small bowel was resected and intestinal continuity restored simultaneously by two end-to-end anastomoses. The postoperative 5-day survival rate was 77.5% (31/40) and 60-day survival rate, 72.5% (29/40). Recipient rats that tolerated the operation remained healthy. Liver and renal function was normal. The liver and intestinal grafts showed normal histological architecture in all rats surviving for 2 months postoperatively. Our results demonstrated that the present model is feasible, allowing preclinical experimental research on combined liver-small bowel transplantation.

Multiorgan transplantation in the rat: Development of a new microsurgical model

Although transplantation of multiple abdominal viscera (MOTx) has been performed in humans, reproducible animal models and extensive laboratory work are needed to explore the physiological and immunological aspects of this new transplant procedure. We therefore developed a microsurgical model that allows en bloc transplantation of three major abdominal viscera. Using isogeneic rat strain combinations, 30% of the liver, pancreas, and duodenum and a segment of small bowel (SB) were heterotopically transplanted. A segment of aorta that included the celiac axis and the superior mesenteric artery provided the blood supply to the graft. Venous outflow occurred via the graft suprahepatic vena cava into the recipient's infrahepatic vena cava. The graft SB was anastomosed to the native SB. After a training period (N = 15), we could achieve a success rate of 83% (N = 23). Mean operation time was 105 minutes. Macroscopic and microscopic appearance of transplanted organs was normal. This study documents the feasibility of MOTx in the rat and provides a microsurgical model that should facilitate preclinical experimental research in this area.