Success rate of current human-derived gastric cancer organoids establishment and influencing factors: A systematic review and meta-analysis.

BACKGROUND: Human-derived gastric cancer organoids (GCOs) are widely used in gastric cancer research; however, the culture success rate is generally low. AIM: To explore the potential influencing factors, and the literature on successful culture rates of GCOs was reviewed using meta-analysis. METHODS: PubMed, Web of Science, and EMBASE were searched for studies. Two trained researchers selected the studies and extracted data. STATA 17.0 software was used for meta-analysis of the incidence of each outcome event. The adjusted Methodological Index for Non-Randomized Studies scale was used to assess the quality of the included studies. Funnel plots and Egger's test were used to detect publication bias. Subgroup analyses were conducted for sex, tissue source, histological classification, and the pathological tumor-node-metastasis (pTNM) cancer staging system. RESULTS: Eight studies with a pooled success rate of 66.6% were included. GCOs derived from women and men had success rates of 67% and 46.7%, respectively. GCOs from surgery or biopsy/endoscopic submucosal dissection showed success rates of 70.9% and 53.7%, respectively. GCOs of poorly-differentiated, moderately-differentiated and signet-ring cell cancer showed success rates of 64.6%, 31%, and 32.7%, respectively. GCOs with pTNM stages I-II and III-IV showed success rates of 38.3% and 65.2%, respectively. Y-27632 and non-Y-27632 use showed success rates of 58.2% and 70%, respectively. GCOs generated with collagenase were more successful than those constructed with Liberase TH and TrypLE (72.1% vs 71%, respectively). EDTA digestion showed a 50% lower success rate than other methods (P = 0.04). CONCLUSION: GCO establishment rate is low and varies by sex, tissue source, histological type, and pTNM stage. Omitting Y-27632, and using Liberase TH, TrypLE, or collagenase yields greater success than EDTA.

In vitro research of oral microscope-assisted implant surface decontamination.

OBJECTIVES: To investigate the effect of oral microscope-assisted surface decontamination on implants in vitro. METHODS: Twelve implants that fell off because of severe peri-implantitis were collected, and decontamination was carried out on the surfaces of implants through curetting, ultrasound, titanium brushing, and sandblasting at 1×, 8×, or 12.8× magnifications. The number and sizes of residues on the implants' surfaces after decontamination were determined, and the decontamination effect was analyzed according to the thread spacing in the different parts of the thread. RESULTS: 1) The 8× and 12.8× groups scored lower for implant surface residues than the 1× group (P<0.000 1), and the 12.8× group scored lower than the 8× group (P<0.001); 2) no difference in residue score was found between the wide and narrow thread pitch (P>0.05), and the 8× and 12.8× groups had lower scores than the 1× group (P<0.001); 3) the lowest number of contaminants was observed at the tip of the thread, whereas the highest was observed below the thread, and the difference was significant (P<0.001). However, the thread pitch had no effect on the number of contaminants in different areas (P>0.05); 4) the residue scores of the 8× and 12.8× groups were lower than those of the 1× group at the thread tip and above, sag, and below the thread of the implants (P<0.05). CONCLUSIONS: Residues on the surfaces of contaminated implants can be effectively removed by using an oral microscope. After decontamination, the residues of pollutants were mainly concentrated below the thread of the implants, and the thread pitch of the implants had no significant effect on the residues.

Antioxidant Activity of New Sulphur- and Selenium-Containing Analogues of Potassium Phenosan against H2O2-Induced Cytotoxicity in Tumour Cells.

Among known phenolic antioxidants, the overwhelming majority of compounds have lipophilic properties and the number of known water-soluble compounds is very small. The list of hydrophilic phenolic antioxidants can be expanded via the synthesis of a structurally related series of polyfunctional compounds for further research on their biological activity in vitro. New sulphur- and selenium-containing analogues of antioxidant potassium phenosan were synthesised. In vitro cytotoxicity and cytostaticity as well as antioxidant activity against H2O2-induced cytotoxicity to human cell lines (HepG2, Hep-2 and MCF-7) were investigated by high-content analysis. A selenium-containing analogue showed higher biological activity than did a sulphur-containing one. As compared to the activity of potassium phenosan, the selenium-containing analogue had a cell line-dependent antioxidant effect against H2O2-induced cytotoxicity: comparable in HepG2 cells and greater in Hep-2 cells. The selenium-containing analogue significantly increased the death of MCF-7 cells at concentrations above 50 µM. The sulphur-containing analogue has lower biological activity as compared to potassium phenosan and the selenium-containing analogue.

Role and relevance of fish cell lines in advanced in vitro research.

INTRODUCTION: Cell line derived from fish has been established as a promising tool for studying many key issues of aquaculture covering fish growth, disease, reproduction, genetics, and biotechnology. In addition, fish cell lines are very useful in vitro models for toxicological, pathological, and immunological studies. The easier maintenance of fish cell lines in flexible temperature regimes and hypoxic conditions make them preferable in vitro tools over mammalian cell lines. Great excitement has been observed in establishing and characterizing new fish cell lines representing diverse fish species and tissue types. The well-characterized and authenticated cell lines are of utmost essential as these represent cellular functions very similar to in vivo state of an organism otherwise it would affect the reproducibility of scientific research. CONCLUSION: The fish cell lines have exhibited encouraging results in several key aspects of in vitro research in aquaculture including virology, nutrition and metabolism, production of vaccines, and transgenic fish production. The review paper reports the cell lines developed from fish, their characterization, and biobanking along with their potential applications and challenges in in vitro research.

Reducing sources of variance in experimental procedures in in vitro research.

Background: Lack of reproducibility in preclinical research poses ethical and economic challenges for biomedical science. Various institutional activities by society stakeholders of leading industrialised nations are currently underway with the aim of improving the situation. Such initiatives are usually concerned with high-level organisational issues and typically do not focus on improving experimental approaches per se. Addressing these is necessary in order to increase consistency and success rates of lab-to-lab repetitions. Methods: In this project, we statistically evaluated repetitive data of a very basic and widely applied lab procedure, namely quantifying the number of viable cells. The purpose of this was to assess the impact of different parameters and instrumentations which may constitute sources of variance in this procedure. Conclusion: By comparing the variability of data acquired under two different procedures, featuring improved stringency of protocol adherence, our project attempts to identify the sources and propose guidelines on how to reduce such fluctuations. We believe our work can contribute to tackling the repeatability crisis in biomedical research.

In Vitro Mechanical and Biological Properties of 3D Printed Polymer Composite and ß-Tricalcium Phosphate Scaffold on Human Dental Pulp Stem Cells.

3D printed biomaterials have been extensively investigated and developed in the field of bone regeneration related to clinical issues. However, specific applications of 3D printed biomaterials in different dental areas have seldom been reported. In this study, we aimed to and successfully fabricated 3D poly (lactic-co-glycolic acid)/ß-tricalcium phosphate (3D-PLGA/TCP) and 3D ß-tricalcium phosphate (3D-TCP) scaffolds using two relatively distinct 3D printing (3DP) technologies. Conjunctively, we compared and investigated mechanical and biological responses on human dental pulp stem cells (hDPSCs). Physicochemical properties of the scaffolds, including pore structure, chemical elements, and compression modulus, were characterized. hDPSCs were cultured on scaffolds for subsequent investigations of biocompatibility and osteoconductivity. Our findings indicate that 3D printed PLGA/TCP and ß-tricalcium phosphate (ß-TCP) scaffolds possessed a highly interconnected and porous structure. 3D-TCP scaffolds exhibited better compressive strength than 3D-PLGA/TCP scaffolds, while the 3D-PLGA/TCP scaffolds revealed a flexible mechanical performance. The introduction of 3D structure and ß-TCP components increased the adhesion and proliferation of hDPSCs and promoted osteogenic differentiation. In conclusion, 3D-PLGA/TCP and 3D-TCP scaffolds, with the incorporation of hDPSCs as a personalized restoration approach, has a prospective potential to repair minor and critical bone defects in oral and maxillofacial surgery, respectively.

The (in)adequacy of translational research in dentistry.

Translational research, as the name suggests, "translates" research findings into clinical practice to improve the health of human beings. The translational process builds on information from experiments conducted at a basic level (i.e., in vitro and/or animal studies) and progresses over experimental human studies for efficacy, efficiency, and safety to implementation. Therefore, all steps in the process should be based on studies conducted with the highest methodological quality possible in order to provide accurate and useful information. Furthermore, the systematic dissemination of new procedures/techniques should be done only when they have been proven to be effective and safe. This focus article describes examples of new techniques/procedures in dentistry that have not resulted from an adequate translational research process since the initial evidence was published. These procedures are generally characterised by lack of good evidence, particularly on their potential harms, and lack of adequate chronological order, regarding the translational research process (i.e., human research being conducted before animal research). Even so, they seem to be widely disseminated, and their promotion involves a wide range of sources, including social media. Some guidance is proposed to improve the quality of the translational research process in dentistry, as well as the level of awareness of all parties involved with the use of this research: clinicians, researchers, and patients. By improving the translational research process, optimization of the application and use of these resources, with less risk to the patients, is expected.

Stereolithographic Surgical Guide with a Combination of Tooth and Bone Support: Accuracy of Guided Implant Surgery in Distal Extension Situation.

A distal free-end situation could result in insufficient stability of the surgical guide, and could reduce accuracy of the static guided implant surgery (sGIS). The purpose of this study was to investigate the accuracy of sGIS using a combination tooth-and-bone supported stereolithographic (SLA) surgical guide in distal extension situation. Thirty dentists, each placed three implants at the Federal Dentaire Internationale (FDI) teeth positions #46, #47 (a distal extension situation), and #36 (a single tooth gap) via the surgical guide on a model fixed to a manikin. Pre- and post-operative computed tomography (CT) images of the models were superimposed, and the positional and angular deviations of the implants were measured with metrology software. An analysis of variance (ANOVA) test was performed to evaluate the intergroup differences. No significant differences were found for all the positional and angular deviations among the three implant sites, except the bucco-lingual deviation at the implant platform in the #47 position (0.43 ± 0.19 mm) that was significantly larger than the #46 (0.21 ± 0.14 mm) and #36 (0.24 ± 0.25 mm) positions (p < 0.0001). Within the limits of this study, we conclude that, in distal extension situation of missing mandibular molars, adding a bone-supported strut in the distal part of the surgical guide can be beneficial to the accuracy of the sGIS.

Minimum Information and Quality Standards for Conducting, Reporting, and Organizing In Vitro Research.

Insufficient description of experimental practices can contribute to difficulties in reproducing research findings. In response to this, "minimum information" guidelines have been developed for different disciplines. These standards help ensure that the complete experiment is described, including both experimental protocols and data processing methods, allowing a critical evaluation of the whole process and the potential recreation of the work. Selected examples of minimum information checklists with relevance for in vitro research are presented here and are collected by and registered at the MIBBI/FAIRsharing Information Resource portal.In addition, to support integrative research and to allow for comparisons and data sharing across studies, ontologies and vocabularies need to be defined and integrated across areas of in vitro research. As examples, this chapter addresses ontologies for cells and bioassays and discusses their importance for in vitro studies.Finally, specific quality requirements for important in vitro research tools (like chemical probes, antibodies, and cell lines) are suggested, and remaining issues are discussed.

What does basic science tell us about the use of uterotonics?

Pharmacotherapy with uterotonics remains the mainstay of the management for post-partum haemorrhage. Clinical studies evaluating the efficacy of these drugs are fraught with confounders, which may influence uterine contractility and blood loss. For this reason, a range of techniques have been developed to study myometrial function in vitro, allowing for the comparison of various drugs in a controlled-simulated physiological environment. In this review, we focus on the main classes of uterotonic drugs and outline their molecular and physiological basis of action. We explore the evidence related to appropriate drug dosing and relative efficacy, and compare the evidence gleaned from clinical and in vitro studies. We discuss the mechanism of oxytocin desensitisation and how basic science has helped us understand this phenomenon. We also discuss the in vitro research findings for each of the main classes of uterotonic drugs that have contributed to an improved understanding of the management of post-partum haemorrhage and, ultimately, better care for mothers.

Canada's Assisted Human Reproduction Act: Pragmatic Reforms in Support of Research.

Canada's Assisted Human Reproduction Act is long overdue for Parliamentary review. We argue that the current regulation of research using human reproductive materials is not proportionate, not responsive to the uncertain threats posed to human and environmental health and safety, and is not considerate of diverse values in a democratic society. We propose tailored regulatory carve-outs for in vitro research for currently prohibited activities, such as gene editing, and for the exercise of Ministerial Discretion for access by Canadians to experimental in vivo interventions that are currently prohibited, such as mitochondrial replacement therapy. Our recommendations are bounded by constitutional constraints that recognize political and practical challenges in keeping oversight of this research under Federal jurisdiction, whether conducted in academic or private sectors. The proposed nuanced regulatory scheme should be overseen by a new national Agency, modeled on a blend of the Canadian Stem Cell Oversight Committee and Assisted Human Reproduction Canada.

Advances in research on cis-9, trans-11 conjugated linoleic acid: a major functional conjugated linoleic acid isomer.

Conjugated linoleic acid (CLA) consists of a group of positional and geometric conjugated isomers of linoleic acid. Since the identification of CLA as a factor that can inhibit mutagenesis and carcinogenesis, thousands of studies have been conducted in the last several decades. Among the many isomers discovered, cis-9, trans-11 CLA is the most intensively studied because of its multiple, isomer-specific effects in humans and animals. This paper provides an overview of the available data on cis-9, trans-11 CLA, including its isomer-specific effects, biosynthesis, in vivo/in vitro research models, quantification, and the factors influencing its content in ruminant products.

Novel murine dendritic cell lines: a powerful auxiliary tool for dendritic cell research.

Research in vitro facilitates discovery, screening, and pilot experiments, often preceding research in vivo. Several technical difficulties render Dendritic Cell (DC) research particularly challenging, including the low frequency of DC in vivo, thorough isolation requirements, and the vulnerability of DC ex vivo. Critically, there is not as yet a widely accepted human or murine DC line and in vitro systems of DC research are limited. In this study, we report the generation of new murine DC lines, named MutuDC, originating from cultures of splenic CD8α conventional DC (cDC) tumors. By direct comparison to normal WT splenic cDC subsets, we describe the phenotypic and functional features of the MutuDC lines and show that they have retained all the major features of their natural counterpart in vivo, the splenic CD8α cDC. These features include expression of surface markers Clec9A, DEC205, and CD24, positive response to TLR3 and TLR9 but not TLR7 stimuli, secretion of cytokines, and chemokines upon activation, as well as cross-presentation capacity. In addition to the close resemblance to normal splenic CD8α cDC, a major advantage is the ease of derivation and maintenance of the MutuDC lines, using standard culture medium and conditions, importantly without adding supplementary growth factors or maturation-inducing stimuli to the medium. Furthermore, genetically modified MutuDC lines have been successfully obtained either by lentiviral transduction or by culture of DC tumors originating from genetically modified mice. In view of the current lack of stable and functional DC lines, these novel murine DC lines have the potential to serve as an important auxiliary tool for DC research.