Specific Organs Research Articles

Recent advances in self-assembling redox nanoparticles as a radiation protective agent

<abstract> <p>The search for potent radiation-protective drugs for clinical use continues. Studies have, so far, focused on targeting the neutralization of radiation-generated reactive oxygen species (ROS) to protect the cells against the deleterious effects of exposure to ionizing radiation. However, the development of efficacious radioprotective drugs, which are mostly low molecular weight (LMW) compounds, is mainly limited due to their inherent toxicity and rapid excretion from the body. Thus, researchers reformulated these LMW compounds into nano-based formulations. This review discusses recent advances in the use of self-assembling redox nanoparticles as a new group of radioprotective agents. The copolymer micelle (herein referred to as redox nanoparticles; RNP) contains an active part, amino-TEMPO, that effectively scavenges radiation-induced ROS in the body, as demonstrated <italic>in vivo</italic>. With the use of nanoparticle-based technologies, optimized formulations of these LMW ROS-neutralizers lead to the significant reduction of its toxicity, high bioavailability and longer blood circulation, which consequently resulted in its notable enhanced efficacy (for example, increased survival rate, reduced radiation-induced syndromes and organ damage) against the damaging effects of ionizing radiation. Consistent with the available data on the use of RNP and other nano-based radioprotective agents, it can be concluded that the inherent ROS-targeting activity of a drug intended for radiation protection is as vital as its bioavailability in the specific tissues and organs, where the short-lived ROS are produced during radiation exposure. In this review article, we summarized the current status of the development of radioprotective agents, including our self-assembling radioprotective agents.</p> </abstract>

Next-generation materials for RNA-lipid nanoparticles: lyophilization and targeted transfection.

RNA, including mRNA, siRNA and miRNA, is part of a new class of patient treatments that prevent and treat several diseases. As an alternative to DNA therapy using plasmid DNA, RNA functions in the cellular cytosol, avoiding the potential risks of insertion into patient genomes. RNA drugs, including mRNA vaccines, need carrier materials for delivery into the patient's body. Several delivery carriers of mRNA, such as cationic polymers, lipoplexes, lipid-polymer nanoparticles and lipid nanoparticles (LNPs), have been investigated. For clinical applications, one of the most commonly selected types of RNA delivery carrier is LNPs, which are typically formed with (a) ionizable lipids, which bind to RNA; (b) cholesterol for stabilization; (c) phospholipids to form the LNPs; and (d) polyethylene glycol-conjugated lipids to prevent aggregation and provide stealth characteristics. Most RNA-LNP research has been devoted to achieving highly efficient RNA expression in vitro and in vivo. It is also necessary to study the extended storage of RNA-LNPs under mild conditions. One of the most efficient methods to store RNA-LNPs for a long time is to prepare freeze-dried (lyophilized) RNA-LNPs. Future research should include investigating LNP materials for the development of freeze-dried RNA-LNPs using optimal lipid components and compositions with optimal cryoprotectants. Furthermore, the development of sophisticated RNA-LNP materials for targeted transfection into specific tissues, organs or cells will be a future direction in the development RNA therapeutics. We will discuss the prospects for the development of next-generation RNA-LNP materials.

Exosome-based drug delivery systems for the treatment of diabetes and its complications: current opinion

Diabetes medication is based on controlling blood glucose and delaying the onset of related complications and is not a complete cure for diabetes. Conventional drug therapy fails to stop progressive islet β cell failure in diabetic patients. Recent studies have shown that "exosome-based therapy" holds great promise in treating diabetes and its complications. Exosomes are small vesicles that are stable in the bloodstream and can effectively deliver therapeutic drugs to specific tissues or organs through intercellular communication. Using exosomes as carriers for drug delivery offers several advantages. This review summarizes the benefits of exosomal drug delivery systems, drug loading methods, and their applications in treating diabetes and its complications. However, there are still challenges to overcome in using exosomal drug delivery systems, such as large-scale production, assessing the contents of exosomes, and monitoring the safety and effectiveness of the treatment in vivo. In conclusion, this review proposes the therapeutical potential of exosomes as drug carriers for developing novel drugs to provide new strategies for treating diabetes and its complications.

The best of both worlds: mastering nerve regeneration combining biological and nanotechnological tools.

The best of both worlds: mastering nerve regeneration combining biological and nanotechnological tools.

The Neuro-Significance of the Human Faculty of the Will: Emphasizing and Understanding the Operations of the Will in Medical Science

Human life is a conglomeration of many operations working synchronistically in chaotic manner. What we refer to as conscious living has underneath it a series of unconscious activity that are well timed and effectively orchestrated to deliver. A good example is in the activity of white blood cells (WBCs), whose activity and action are triggered when there is a foreigner in the body. Their effectiveness has dubbed them the soldiers of the human body, responding to threats and seeking out ways to nullify any that has arisen, even when the human person is unconscious of the threat. We can cite many other examples to make concrete the assertion that the human life is a conglomeration of much operation working synchronistically in chaotic manner. However, what is important to this research at present is to ascertain the function of the human will in all that pertains to the human life. This is on the conscious plane (for the other cited example on WBCs, are on the unconscious plane). The human will (volition) is an operational faculty that is not attached to any specific organ in the body (albeit in the brain, since its expression is cognitively mediated); the human will is not a physically concrete, but its effect is however felt. Its domain is the conscious plane, and it is there that its effect is felt. The human person is a conscious determiner of his acts and even when medical (biological) science, consider this to be tied to the functioning of the brain; it is to be stated that the human person is not his brain. In consciously determining his acts, many cranial areas are employed; however, it is not these cranial areas that determine the eventual choice that is made. Thus there must be something else. The hypothesis in this research favors the will. This is what we seek to elaborate upon.

Putting infection on the map: Using heatmaps to characterise within- and between-host distributions of trematode metacercariae.

The location of parasites within individual hosts is often treated as a static trait, yet many parasite species can occur in multiple locations or organs within their hosts. Here, we apply distributional heat maps to study the within- and between-host infection patterns for four trematodes (Alaria marcianae, Cephalogonimus americanus, Echinostoma spp. and Ribeiroia ondatrae) within the amphibian hosts Pseudacris regilla and two species of Taricha. We developed heatmaps from 71 individual hosts from six locations in California, which illustrate stark differences among parasites both in their primary locations within amphibian hosts as well as their degree of location specificity. While metacercariae (i.e., cysts) of two parasites (C. americanus and A. marcianae) were relative generalists in habitat selection and often occurred throughout the host, two others (R. ondatrae and Echinostoma spp.) were highly localised to a specific organ or organ system. Comparing parasite distributions among these parasite taxa highlighted locations of overlap showing potential areas of interactions, such as the mandibular inner dermis region, chest and throat inner dermis and the tail reabsorption outer epidermis. Additionally, the within-host distribution of R. ondatrae differed between host species, with metacercariae aggregating in the anterior dermis areas of newts, compared with the posterior dermis area in frogs. The ability to measure fine-scale changes or alterations in parasite distributions has the potential to provide further insight about ecological questions concerning habitat preference, resource selection, host pathology and disease control.

'Passive' nanoparticles for organ-selective systemic delivery: design, mechanism and perspective.

Nanotechnology has shown tremendous success in the drug delivery field for more effective and safer therapy, and has recently enabled the clinical approval of RNA medicine, a new class of therapeutics. Various nanoparticle strategies have been developed to improve the systemic delivery of therapeutics, among which surface modification of targeting ligands on nanoparticles has been widely explored for 'active' delivery to a specific organ or diseased tissue. Meanwhile, compelling evidence has recently been reported that organ-selective targeting may also be achievable by systemic administration of nanoparticles without surface ligand modification. In this Review, we highlight this unique set of 'passive' nanoparticles and their compositions and mechanisms for organ-selective delivery. In particular, the lipid-based, polymer-based, and biomimetic nanoparticles with tropism to different specific organs after intravenous administration are summarized. The underlying mechanisms (e.g., protein corona and size effect) of these nanosystems for organ selectivity are also extensively discussed. We further provide perspectives on the opportunities and challenges in this exciting area of organ-selective systemic nanoparticle delivery.

A Review on Aharawith special referenceto body organs

According to Ayurveda, all living and non living objects in the universe are made up of Panchamahabhutas. In accordance with the requirements of LokaPurushaSamayaSiddhanta1, the world and the human body are connected entities with the same panchabhutaconstitution. Finding things that behave or look like organs and figuring out which foods are ideal for a certain organ or organ system both use the same notion. CarakaSamhitadescribes three supports of life viz. ahara(intake of food), nidra(sleep) and bramhacarya(control of senses and spiritual bliss conducive to the knowledge of Bramhan). Food (ahara) is regarded as the most significant of these. Hitakara/pathyadiet promotes longevity, strength, intelligence, a clear voice, and a healthy complexion in addition to maintaining good health. Organs should be kept healthy to improve our overall quality of life. Different diet products are mentioned for various organs to keep them healthy and disease free.Various pathyaaharaare being mentioned here for specific organs which is to be followed by everyone along with proper Dinacharyaand Ritucharyaaccordingly

Natural and synthetic nanovectors for cancer therapy.

Nanomaterials have been extensively studied in cancer therapy as vectors that may improve drug delivery. Such vectors not only bring numerous advantages such as stability, biocompatibility, and cellular uptake but have also been shown to overcome some cancer-related resistances. Nanocarrier can deliver the drug more precisely to the specific organ while improving its pharmacokinetics, thereby avoiding secondary adverse effects on the not target tissue. Between these nanovectors, diverse material types can be discerned, such as liposomes, dendrimers, carbon nanostructures, nanoparticles, nanowires, etc., each of which offers different opportunities for cancer therapy. In this review, a broad spectrum of nanovectors is analyzed for application in multimodal cancer therapy and diagnostics in terms of mode of action and pharmacokinetics. Advantages and inconveniences of promising nanovectors, including gold nanostructures, SPIONs, semiconducting quantum dots, various nanostructures, phospholipid-based liposomes, dendrimers, polymeric micelles, extracellular and exome vesicles are summarized. The article is concluded with a future outlook on this promising field.

Validity of biopsychosocial model of intervention in contemporary medical practice: Walking a few extra miles

Validity of biopsychosocial model of intervention in contemporary medical practice: Walking a few extra miles

Early Detection of Alzheimer’s Disease Based on Laplacian Re-Decomposition and XGBoosting

The precise diagnosis of Alzheimer’s disease is critical for patient treatment, especially at the early stage, because awareness of the severity and progression risks lets patients take preventative actions before irreversible brain damage occurs. It is possible to gain a holistic view of Alzheimer’s disease staging by combining multiple data modalities, known as image fusion. In this paper, the study proposes the early detection of Alzheimer’s disease using different modalities of Alzheimer’s disease brain images. First, the preprocessing was performed on the data. Then, the data augmentation techniques are used to handle overfitting. Also, the skull is removed to lead to good classification. In the second phase, two fusion stages are used: pixel level (early fusion) and feature level (late fusion). We fused magnetic resonance imaging and positron emission tomography images using early fusion (Laplacian Re-Decomposition) and late fusion (Canonical Correlation Analysis). The proposed system used magnetic resonance imaging and positron emission tomography to take advantage of each. Magnetic resonance imaging system’s primary benefits are providing images with excellent spatial resolution and structural information for specific organs. Positron emission tomography images can provide functional information and the metabolisms of particular tissues. This characteristic helps clinicians detect diseases and tumor progression at an early stage. Third, the feature extraction of fused images is extracted using a convolutional neural network. In the case of late fusion, the features are extracted first and then fused. Finally, the proposed system performs XGB to classify Alzheimer’s disease. The system’s performance was evaluated using accuracy, specificity, and sensitivity. All medical data were retrieved in the 2D format of 256 × 256 pixels. The classifiers were optimized to achieve the final results: for the decision tree, the maximum depth of a tree was 2. The best number of trees for the random forest was 60; for the support vector machine, the maximum depth was 4, and the kernel gamma was 0.01. The system achieved an accuracy of 98.06%, specificity of 94.32%, and sensitivity of 97.02% in the case of early fusion. Also, if the system achieved late fusion, accuracy was 99.22%, specificity was 96.54%, and sensitivity was 99.54%.

ПОЛИМИОЗИТ: НОВЫЙ ВЗГЛЯД НА СТАРУЮ ПРОБЛЕМУ

Idiopathic inflammatory myopathies are the group of rare heterogeneous autoimmune diseases of unknown etiology, characterized by inflammatory le-sions of the striated muscles and skin, as well as the development of specific organ pathology. The history of the study idiopathic inflammatory myopathies has more than 100 years. Initially, this group of diseases included only 2 main subtypes: dermatomysitis and polymyositis. The latter was the main subtype of myopathies, it corresponded to 2/3 of the clinical descriptions of this pa-thology available at that time. The discovery of myositis-specific and myositis-associated autoantibodies at the end of the 20th century made it possible to significantly expand the understanding of the pathogenesis of idiopathic in-flammatory myopathies. Not only the autoimmune genesis of myopathies was proven, but also their immunological heterogeneity, as well as the existence of clinical and immunological subtypes. Today, with no serological markers, no skin lesions, and no unique histo-logical presentation, polymyositis is a difficult-to-diagnose disease that can of-ten be misdiagnosed in patients with another pathology or subtype of idio-pathic inflammatory myopathies. According to most experts, polymyositis is currently a diagnosis of exclusion and is the rarest subtype of idiopathic in-flammatory myopathies, accounting to no more than 5 % of all cases in this group.

Time-Lapse Imaging and Morphometric Analysis of Tracheal Development in Drosophila.

Detailed and quantitative analyses of the cellular events underlying the formation of specific organs or tissues is essential to understand the general mechanisms of morphogenesis and pattern formation. Observation of live tissues or whole-mount fixed specimens has emerged as the method of choice for identifying and quantifying specific cellular and tissular structures within the organism. In both cases, cell and subcellular structure identification and good quality image acquisition for these analyses are essential. Many markers for live imaging and fixed tissue are now available for detecting cell membranes, subcellular structures, and extracellular structures like the extracellular matrix (ECM). Combination of live imaging and analysis of fixed tissue is ideal to obtain a general and detailed picture of the events underlying embryonic development. By applying morphometric methods to both approaches, we can, in addition, obtain a quantitative evaluation of the specific parameters under investigation in morphogenetic and cell biological studies. In this chapter, we focus on the development of the tracheal system of Drosophila melanogaster, which provides an ideal paradigm to understand the formation of branched tubular organs. We describe the most used methods of imaging and morphometric analysis in tubulogenesis using mainly (but not exclusively) examples from embryonic development. We cover embryo preparation for fixed and live analysis of tubulogenesis, together with methods to visualize larval tracheal terminal cell branching and lumen formation. Finally, we describe morphometric analysis and quantification methods using fluorescent images of tracheal cells.

Cytokinins

The extraordinary variety that characterizes the living world in terms of forms and structures is the result of natural selection that allows an organism to be in perfect harmony with its environmental niche. Once a specific shape is acquired, many different factors act together to guarantee phenotypic robustness and developmental stability of the organism. Among these factors, hormones play a key role in the regulation and coordination of growth - they control the activity of a single cell, the progression to tissue organization, the development of specific organs, ending with the development of the entire body. In plants, hormones acquire yet another important role - plants, due to their sessile nature, along with the quest for robust development, rely on plastic development to adapt growth to a changing environment. Plant hormones play a crucial role in sensing and responding to different environmental stimuli, translating these inputs into specific developmental changes that adapt the plant body to the environment. Here, we will focus on cytokinins - a unique class of plant hormones - giving clues on their metabolism, on how they are perceived by cells and how cells change their activity in response to it. Most of the data presented have been derived by studies conducted on Arabidopsis thaliana, a plant used as a model system in plant science.

Acute and subacute oral toxicity characterization and safety assessment of COVID organics® (Madagascar's Anti-COVID Herbal Tea) in animal models.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2. No drug has been generally approved as safe and effective for the treatment of COVID-19. Several therapeutic agents such as COVID Organics® (CVO) have been explored as treatment options. CVO is an herbal tea composed of 62% of Artemisia annua and 38% of other plants. There is presently no existing scientific report and data on the safety and efficacy of CVO herbal drug. Thus, acute and subacute toxicity studies were undertaken to evaluate the safety and toxicity of CVO on short- and long-term usage in animal models. Phytochemical and nutritional compositions of CVO were determined using standard methods. Acute oral toxicity was investigated using female Swiss albino mice (three per group). While subacute oral toxicity was done using female and male Swiss albino rats (five per group). The animals were administered 2000 mg/kg, 5000 mg/kg, therapeutic dose; 5500 mg/kg and supratherapeutic dose; 11,000 mg/kg of CVO herbal product. The control group received water ad libitum. The oral toxicity studies were done in accordance with Organization for Economic Corporation and Development guidelines. The experimental protocol was approved by the Institutional Animal Care and Use Committee, Nigerian Institute of Medical Research (Ethics No. IRB/17/043). CVO is rich in antioxidants: flavonoids (10.3%), tannins (29.1%), and phenolics (434.4 mg). It contains proteins (33.8%), carbohydrates (34.5%), fat (6.8%), and fiber (0.5%). In the acute toxicity study, no mortality was recorded in all the treated and untreated groups. The lethal dose of CVO is >5000 mg/kg body weight. The hematological, biochemical, lipid profile, and histologic parameters were all normal at therapeutic doses when compared to the control group. The acute and subacute oral toxicity studies revealed that CVO is not toxic. The specific organ toxicity evaluations also indicated that CVO has no toxic effects on blood parameters and vital organs structure and function at therapeutic dose. Thus, CVO is safe for short- and long-term usage. We recommend that CVO should be subjected to efficacy studies to investigate whether it is effective for COVID-19 treatment as claimed by the manufacturer.

Identification of biomarkers to stratify response to B-cell-targeted therapies in systemic lupus erythematosus: an exploratory analysis of a randomised controlled trial.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease associated with widespread immune dysregulation and diverse clinical features. Immune abnormalities might be differentially associated with specific organ involvement or response to targeted therapies. We aimed to identify biomarkers of response to belimumab after rituximab to facilitate a personalised approach to therapy. In this exploratory analysis of a randomised controlled trial (BEAT-LUPUS), we investigated immune profiles of patients with SLE recruited to the 52-week clinical trial, which tested the combination of rituximab plus belimumab versus rituximab plus placebo. We used machine learning and conventional statistics to investigate relevant laboratory and clinical biomarkers associated with major clinical response. BEAT LUPUS is registered at ISRCTN, 47873003, and is now complete. Between Feb 2, 2017, and March 28, 2019, 52 patients were recruited to BEAT-LUPUS, of whom 44 provided clinical data at week 52 and were included in this analysis. 21 (48%) of 44 participants were in the belimumab group (mean age 39·5 years [SD 12·1]; 17 [81%] were female, four [19%] were male, 13 [62%] were White) and 23 (52%) were in the placebo group (mean age 42·1 years [SD 10·5]; 21 [91%] were female, two [9%] were male, 16 [70%] were White). Ten (48%) of 21 participants who received belimumab after rituximab and eight (35%) of 23 who received placebo after rituximab had a major clinical response at 52 weeks (between-group difference of 13% [95% CI -15 to 38]). We found a predictive association between baseline serum IgA2 anti-double stranded DNA (dsDNA) antibody concentrations and clinical response to belimumab after rituximab, with a between-group difference in major clinical response of 48% (95% CI 10 to 70) in patients with elevated baseline serum IgA2 anti-dsDNA antibody concentrations. Moreover, among those who had a major clinical response, serum IgA2 anti-dsDNA antibody concentrations significantly decreased from baseline only in the belimumab group. Increased circulating IgA2 (but not total) plasmablast numbers, and T follicular helper cell numbers predicted clinical response and were both reduced only in patients who responded to belimumab after rituximab. Serum IgA2 anti-dsDNA antibody concentrations were also associated with active renal disease, whereas serum IgA1 anti-dsDNA antibody and IFN-α concentrations were associated with mucocutaneous disease activity but did not predict response to B-cell targeted therapy. Patients with a high baseline serum interleukin-6 concentration were less likely to have a major clinical response, irrespective of therapy. This exploratory study revealed the presence of distinct molecular networks associated with renal and mucocutaneous involvement, and response to B-cell-targeted therapies, which, if confirmed, could guide precision targeting of advanced therapies for this heterogenous disease. Versus Arthritis, UCLH Biomedical Research Centre, LUPUS UK, and GSK.

Intravoxel Incoherent Motion Quantification Dependent on Measurement SNR and Tissue Perfusion: A Simulation Study.

The intravoxel incoherent motion (IVIM) model extracts both functional and structural information of a tissue using motion-sensitizing gradients. The Objective of the present work is to investigate the impact of signal to noise ratio (SNR) and physiologic conditions on the validity of IVIM parameters. This study is a simulation study, modeling IVIM at a voxel, and also done 10,000 times for every single simulation. Complex noises with various standard deviations were added to signal in-silico to investigate SNR effects on output validity. Besides, some blood perfusion situations for different tissues were considered based on their physiological range to explore the impacts of blood fraction at each voxel on the validity of the IVIM outputs. Coefficient variation (CV) and bias of the estimations were computed to assess the validity of the IVIM parameters. This study has shown that the validity of IVIM output parameters highly depends on measurement SNR and physiologic characteristics of the studied organ. IVIM imaging could be useful if imaging parameters are correctly selected for each specific organ, considering hardware limitations.

Comparison of Metastatic Patterns Among Neuroendocrine Tumors, Neuroendocrine Carcinomas, and Nonneuroendocrine Carcinomas of Various Primary Organs.

Both neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs) exhibit neuroendocrine differentiation and are classified as neuroendocrine neoplasms (NENs). NECs and nonneuroendocrine neoplasms (non-NENs), such as adenocarcinoma, have similar mutational profiles. The purpose of this study was to identify differences in metastatic patterns and to identify the key factor causing these differences by simultaneously comparing the metastatic patterns of NETs, NECs and non-NENs from various primary organs. We retrieved data for 4,223 patients with NENs and 41,637 patients with non-NENs arising at various primary sites from an institutional database and then compared NET, NEC, and non-NEN metastatic patterns. NETs and NECs showed generally similar metastatic patterns. Most NEN patients had a higher liver organotrophic metastasis rate, lower lung organotrophic metastasis rate, and lower pleural/peritoneal organotrophic metastasis rate than non-NEN patients. Some differences were characteristics of specific organs. Some of these site-specific differences were not caused by NENs but by non-NENs, including a higher bone organotrophic metastasis rate for medullary thyroid carcinoma and a lower bone organotrophic metastasis rate for pulmonary NEN. Other differences were probably caused by NENs, including a higher bone organotrophic metastasis rate for colorectal NETs. Uterine cervical NEC showed unique patterns of metastasis compared to NEN from other sites. Significant differences between the metastatic patterns of NENs and non-NENs were detected. The multigene program that causes neuroendocrine differentiation might be associated with organotropic metastasis.

Unfavorable tumor responses to immunotherapy in the liver: Lessons learned from clinical and preclinical studies

Objective: Immunotherapy with immune checkpoint inhibitors (ICIs) has become a standard of care for many malignancies. The tumor microenvironment (TME) varies across different organs and affects tumor initiation, progression, and treatment outcomes. Organ-specific differential responses to ICIs have been observed in various cancers. The underlying mechanisms warrant further investigation. Data Sources and Study Selection: We enrolled relevant clinical and preclinical studies conducted by our groups and others. Current evidence and data were reviewed and future implication was discussed. Results: In patients with advanced hepatocellular carcinoma or esophageal cancer, non-small cell lung cancer, or melanoma with liver metastases, the efficacy of ICI-based therapy was generally lower in the liver than in other organs. The mouse liver cancer study showed that myeloid-derived suppressor cells (MDSCs) might play a role in immunosuppressive TME in the liver as compared to subcutaneous tissues; targeting MDSCs enhanced anti-tumor efficacy in the liver. The metastatic colon cancer models showed that monotherapy with anti-programmed death ligand-1 (PD-L1) antibody was less effective in suppressing tumor growth in the liver than in subcutaneous tissues. Mechanistically, modulation of hepatic innate immune cells was associated with the improved response of anti-PD-L1 antibody in the liver. Conclusion: The relatively unfavorable tumor response to immunotherapy in the liver of various cancers may be attributable to the immunosuppressive hepatic TME. Future comprehensive immune profiling is required to identify key factors and mechanisms in specific organs to overcome immunosuppressive TME, particularly in the liver.

Distinguishing between ante factum and post factum properties of animal cell lines and demonstrating their use in grouping ray-finned fish cell lines into invitromes.

In this review, animal cell lines are considered to have two classes of attributes: "before-the-fact" (ante factum) and "after-the-fact" (post factum) properties. Fish cell lines from Actinopterygii (ray-finned fishes) are used to illustrate this distinction and to demonstrate how these properties can be used in various ways to categorize cell lines into groups or invitromes. Before-the-fact properties are set at initiation and are properties of the sample and species from which the cell line arose and of the scientist(s) who developed the cell line. On the basis of the Actinopterygii sample, invitromes exist for embryos, larvae, juveniles, adults, and spawning fish, and for most solid organs but rarely for biological fluids. For species, invitromes exist for only a small fraction of the Actinopterygii total. As to their development, scientists from around the world have contributed to invitromes. By contrast, after-the-fact properties are limitless and become apparent during development, characterization, use, and storage of the cell line. For ray-finned invitromes, cell lines appear to acquire immortality during development, are characterized poorly for differentiation potential, have numerous uses, and are stored formally only sporadically. As an example of applying these principles to a specific organ, the skeletal muscle invitrome is used. For ante factum properties, the cell lines are mainly from trunk muscle of economically important fish from 11 orders, 15 families, 19 genera, and 21 species of ray-finned fishes. For post factum properties, fibroblast-like and myogenic cell lines have been described but epithelial-like FHM is most widely used and curated. Considering cell lines by their before- and after-the-fact properties should facilitate integration of new cell lines into the literature and help incorporate the discipline of cell biology into other research areas, particularly the natural history of fishes.