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Synchrotron-based tomographic phase-contrast X-ray imaging (SRµCT or SRnCT) is a versatile isotropic three-dimensional imaging technique that can be used to study biological samples spanning from single cells to human-sized specimens. SRµCT and SRnCT take advantage of the highly brilliant and coherent X-rays produced by a synchrotron light source. This enables fast data acquisition and enhanced image contrast for soft biological samples owing to the exploitation of phase contrast. In this Review, we provide an overview of the basics behind the technique, discuss its applications for biologists and provide an outlook on the future of this emerging technique for biology.We introduce the latest advances in the field, such as whole human organs imaged with micron resolution, using X-rays as a tool for virtual histology and resolving neuronal connections in the brain. [ABSTRACT FROM AUTHOR]

Cell-instructive biomaterials are an essential component in tissue engineering and regenerative medicine. In the past three decades since the term "Tissue Engineering" was coined, researchers have made significant progress towards regenerating disease or damage tissues and organs by combining innovations in biomaterials, signaling molecules and cell therapies. However, challenges persist including limitations in properties of cell-instructive biomaterials, lack of advanced manufacturing technologies for precise spatiotemporal control of key players in tissue engineering, and hurdles in clinical translation and regulatory process. In this perspective article, we briefly review the current state of the field including the evolution in our understanding of the role biomaterial mechanics and scaffolding architecture, development of self-healing and modular biomaterials, and progress in advanced manufacturing technologies such as 3D bioprinting. In addition, we discuss about how innovation in research technologies including multi-omics and spatial biology, and advanced imaging modalities may pave the way for enhancing our understanding about cellbiomaterial interactions. Finally, we present our perspective as early career clinicians and researchers on the key role and potential impact that clinicianscientists can generate in the development, validation, clinical translation and adoption of the next-generation of cell-instructive biomaterials for application in engineering tissues and organs to impact human health. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cafeteria diet (CAF) is a succesful tool for establishing animal obesity model. This study purposed to show immunoexpression and oxidant-antioxidant status in the various organ tissues of Wistar rats fed CAF. METHODS: Two groups (six rats per group) of Wistar albino rats were fed CAF and standard chow (control) diets for eight weeks. After experimental procedure, the animals were sacrificed. Intestine, stomach, liver, kidney, spleen, heart, lung, and pancreas tissues were sent to Pathology Department and inducible nitric oxide synthase (iNOS), nuclear factor- κB (NF-κB) and cannabinoid receptor-1 (CB-1) immunoexpressions were assessed. Also, plasma liver function tests and lipid levels were measured total oxidant capacity (TOC) and total antioxidant capacity (TAC) were evaluated in both plasma and liver tissue. RESULTS: The immunoexpressions of NF-κB, iNOS and CB-1 were higher in the experiment group for all tissues. TOC was significantly higher in the experiment group, for both plasma and liver tissue (p < 0.001 and p = 0.02). TAC was higher in the experiment group's plasma measurement (p = 0.02), while there was no difference in the liver tissue between experiment and control groups (p = 0.11). CONCLUSION: CAF-induced obesity may be related to increased immunoexpression and oxidative damage in the various organs. Systemic problems should be considered and these phenomenon should be studied more comprehensively. [ABSTRACT FROM AUTHOR]

Microdosimetry studies are a description to better understand the mechanisms of biological effects of ionizing radiation to improve cancer and minimize environmental and occupational hazards. Due to the impossibility of studying living human organs, and reducing animal experimentation, microdosimeter walls are made of alternative tissue-equivalent materials such as A-150 tissue-equivalent plastic and polyethylene to obtain experimental results. In order to measure dose and dose distribution with high accuracy in micron dimensions in body tissues, it is necessary to investigate microdosimetric quantities and determine under what conditions these alternative materials can be used instead of tissues. In this article, by using the Geant4 simulation code, we have studied the relative difference of the studied quantities in microdosimetry of A-150 tissue-equivalent plastic and polyethylene with three major body tissues including soft, fat and compact (cortical) bone tissue and for this purpose, we simulated the microdosimeter of right cylinders with 2 microns' sizes for neutron beam with energies of 0.1, 1, and 10 MeV. We observed that the maximum relative difference percentage of the frequency-mean lineal energy of soft, fat, and compact bone tissue in comparison with polyethylene is 6.26, 6.3, and 12.89%, respectively. It in comparison with A-150 tissue-equivalent plastic is 3.21, 3.25, and 13.75%, respectively. Therefore, we can use these alternative materials instead of the mentioned tissues by applying these corrections. We found that the use of alternative tissue equivalent materials depends on the neutron energy and tissue type; full details are reported in the text of the article. [ABSTRACT FROM AUTHOR]

Simple Summary: Selenium is a trace element needed for proper growth and development in both humans and animals. The aim of this study was to determine the concentration of total selenium in the main tissues and to evaluate the differences in tissue distribution in beef cattle with different selenium status. It was found that despite receiving supplementation, 44.44% of the examined cattle were deficient in selenium. The highest percentage of deficient animals was recorded among the heifers (62.5%), and the lowest in bulls (30.43%). Differences in Se tissue distribution were observed between Se-deficient animals and those with normal Se status. The organs most susceptible to Se deficiency are the semitendinosus muscle, lungs, heart and liver. Our findings confirm that Se deficiencies can be found among supplemented animals. Selenium deficiency in beef cattle may be related to the uneven uptake of the element, but also to the individual predispositions of animals. It is recommended to monitor Se levels to detect deficiencies and, if necessary, to respond by increasing selenium supply. The aim of this study was to determine the Se concentration in the main tissues of beef cattle and to evaluate the differences in tissue distribution between animals with different selenium status. Selenium concentration was determined in the serum, longissimus dorsi muscle, semitendinosus muscle, kidney, heart, liver, spleen and lungs of cows, heifers and beef bulls, using spectrofluorimetric method. Despite receiving supplementation, 55.6% animals demonstrated an optimal Se level, while 44.4% were deficient. The mean serum Se concentration was significantly higher (p < 0.05) in animals with a normal Se status than in Se-deficient animals. Differences in Se tissue distribution were observed between Se-deficient animals and those with normal Se status. The organs most susceptible to Se deficiency are the semitendinosus muscle, lungs, heart and liver. In both normal and Se-deficient animals, significantly higher Se concentrations were observed in the kidney than other organs (p < 0.05), and the lowest in the muscles. As Se deficiencies can be found among supplemented animals, the level of Se should be monitored in beef cattle in order to detect possible Se deficiencies, which may have negative health effects for animals and reduce the value of animal products as a source of Se in the human diet. [ABSTRACT FROM AUTHOR]

For centuries, the brain has been considered a single organ from an anatomical and functional perspective. However, while the cerebral cortex, consisting of many lobes and lobules, generally creates voluntary actions, autonomous parts of the brain also carry out vital activities such as survival, reproduction, and nutrition. The functions of the group of organs that carry out basic vital activities are modulated by autonomous ganglia that work like the deep intelligence networks of the brain. Information and energy packets produced as different molecules in vital organs and sent to the autonomous ganglia are decoded. These packages are then made available for use by cells, tissues, and organs. This deep information, purified and summarized by the autonomic ganglia, is presented to the cerebral cortex after passing through the control of the brainstem and insula. As a result, the entire brain and all the organs under its control decide together what to do. From this conceptual perspective, the brain is a united states group with different states under its management; the autonomic ganglia can also be thought of as the brain's deep intelligence networks. [ABSTRACT FROM AUTHOR]

The question of whether donors should be able to set conditions on who can receive their tissue has been discussed by bioethicists, but so far there has been little consideration of whether the answer to this question should be different depending on the type of tissue under discussion. In this article, we compare the donation of organs with the donation of reproductive material such as sperm, eggs, and embryos, exploring possible arguments for allowing donors to set conditions in one case but not the other. After considering arguments from procreative liberty, special parental obligations, and donors meeting their genetic offspring, we find that there is no ethically defensible reason to have different policies between these two cases. As a consequence, we conclude that jurisdictions operating with this inconsistency should consider moving their policies into better alignment. We also make some recommendations for the standardisation of the terminology around conditional donation. [ABSTRACT FROM AUTHOR]

The propagation of acoustic waves in fluids and solids produces fascinating phenomena that have been studied since the late 1700s and through to today, where it is finding broad application in manipulating fluids and particles at the micro to nano-scale. Due to the recent and rapid increase in application frequencies and reduction in the scale of devices to serve this new need, discrepancies between theory and reality have driven new discoveries in physics that are underpinning the burgeoning discipline. While many researchers are continuing to explore the use of acoustic waves in microfluidics, some are exploring vastly smaller scales, to nanofluidics and beyond. Because many of the applications incorporate biological material--organelles, cells, tissue, and organs--substantial effort is also being invested in understanding how ultrasound interacts with these materials. Surprisingly, there is ample evidence that ultrasound can be used to directly drive cellular responses, producing a new research direction beyond the established efforts in patterning and agglomerating cells to produce tissue. We consider all these aspects in this mini-review after a brief introduction to acoustofluidics as an emerging research discipline. [ABSTRACT FROM AUTHOR]

New psychoactive substances continue to appear on the drug market, and alpha-pyrrolidinoisohexanophenone (α-PiHP) is one of the most popular cathinone derivatives. In this article, we report a case of death caused by α-PiHP. Based on the toxicological results of the studied case along with autopsy, histopathological findings and crime-scene information, fatal intoxication with α-PiHP was accepted as the final cause of death. α-PiHP and its metabolite (OH-α-PiHP) were detected and quantified in all postmortem materials (blood collected from the heart, the femoral vein and the dural venous sinuses; vitreous humor; cerebrospinal fluid; cerebral cortex; brainstem; cerebellum; bile; liver; kidney; heart; pancreas; spleen; thyroid gland; lung; adipose tissue; stomach and intestine). To date, this is the first case of determination of α-PiHP and its metabolite in postmortem specimens. In our opinion, α-PiHP and its metabolite concentration database can be helpful in the interpretation of fatal cases. [ABSTRACT FROM AUTHOR]

The study of chromatin accessibility across tissues and developmental stages is essential for elucidating the transcriptional regulation of various phenotypes and biological processes. However, the chromatin accessibility profiles of multiple tissues in newborn pigs and across porcine liver development remain poorly investigated. Here, we used ATAC-seq and rRNA-depleted RNA-seq to profile open chromatin maps and transcriptional features of heart, kidney, liver, lung, skeletal muscle, and spleen in newborn pigs and porcine liver tissue in the suckling and adult stages, respectively. Specifically, by analyzing a union set of protein-coding genes (PCGs) and two types of transcripts (lncRNAs and TUCPs), we obtained a comprehensive annotation of consensus ATAC-seq peaks for each tissue and developmental stage. As expected, the PCGs with tissue-specific accessible promoters had active transcription and were relevant to tissue-specific functions. In addition, other non-coding tissue-specific peaks were involved in both physical activity and the morphogenesis of neonatal tissues. We also characterized stage-specific peaks and observed a close association between dynamic chromatin accessibility and hepatic function transition during liver postnatal development. Overall, this study expands our current understanding of epigenetic regulation in mammalian tissues and organ development, which can benefit both economic trait improvement and improve the biomedical usage of pigs. [ABSTRACT FROM AUTHOR]

Biomimicking organ phantoms with vivid biological structures and soft and slippery features are essential for in vitro biomedical applications yet remain hither to unmet challenges in their fabrication such as balancing between spatial structural complexity and matchable mechanical properties. Herein, 3D printable tissue‐mimicking elastomeric double network hydrogels with tailorable stiffness are evolved to idiosyncratically match diverse biological soft tissues by regulating the compositions of hydrogel matrix and the density of metal coordination bonds. Relying on digital light processing 3D printing, various mechanically tunable biomimetic volumetric hydrogel organ constructs with structural complexity and fidelity, including kidney, brain, heart, liver, stomach, lung, trachea, intestine, and even the intricate vascularized tissues, are fabricated faultlessly. Proof‐of‐concept 3D printed hydrogel heart and liver phantoms provide sophisticated internal channels and cavity structures and external realistic anatomical architectures that more closely mimic native organs. For the in vitro application demonstration, a 3D printed hydrogel brain phantom with tortuous cerebral arteries and slippery characters serves as an effective neurosurgical training platform for realistic simulation of endovascular interventions. This platform offers a means to construct mechanically precisely tunable hydrogel‐based biomimetic organ phantoms that are expected to be used in surgical training, medical device testing, and organs‐on‐chips. [ABSTRACT FROM AUTHOR]

Lipids are biomolecules involved in numerous (patho-)physiological processes and their elucidation in tissue samples is of particular interest. However, tissue analysis goes hand in hand with many challenges and the influence of pre-analytical factors can intensively change lipid concentrations ex vivo, compromising the results of the whole research project. Here, we study the influence of pre-analytical factors on lipid profiles during the processing of homogenized tissues. Homogenates from four different mice tissues (liver, kidney, heart, spleen) were stored at room temperature as well as in ice water for up to 120 min and analyzed via ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). Lipid class ratios were calculated since their suitability as indicators for sample stability has been previously illustrated. Only approx. 40% of lipid class ratios were unchanged after 35 min, which was further reduced to 25% after 120 min during storage at room temperature. In contrast, lipids in tissue homogenates were generally stable when samples were kept in ice water, as more than 90% of investigated lipid class ratios remained unchanged after 35 min. Ultimately, swift processing of tissue homogenates under cooled conditions represents a viable option for lipid analysis and pre-analytical factors require more attention to achieve reliable results. [ABSTRACT FROM AUTHOR]

Spatially resolved transcriptomics of tissue sections enables advances in fundamental and applied biomedical research. Here, we present Multiplexed Deterministic Barcoding in Tissue (xDBiT) to acquire spatially resolved transcriptomes of nine tissue sections in parallel. New microfluidic chips were developed to spatially encode mRNAs over a total tissue area of 1.17 cm2 with a 50 µm resolution. Optimization of the biochemical protocol increased read and gene counts per spot by one order of magnitude compared to previous reports. Furthermore, the introduction of alignment markers allowed seamless registration of images and spatial transcriptomic spots. Together with technological advances, we provide an open-source computational pipeline to prepare raw sequencing data for downstream analysis. The functionality of xDBiT was demonstrated by acquiring 16 spatially resolved transcriptomic datasets from five different murine organs, including the cerebellum, liver, kidney, spleen, and heart. Factor analysis and deconvolution of spatial transcriptomes allowed for in-depth characterization of the murine kidney. Examining the spatially resolved transcriptome of tissue sections promises advances in biomedical research. Here, the authors present xDBiT, a versatile, microfluidics-based approach to cost-effectively measure the spatial transcriptome of multiple tissue sections in parallel. [ABSTRACT FROM AUTHOR]

Background: Normal tissue complication probability (NTCP) models are often based on doses retrieved from delineated volumes. For retrospective doseresponse studies focusing on organs that have not been delineated historically, automatic segmentation might be considered. However, automatic segmentation risks generating considerable delineation errors and knowledge regarding how these errors impact the estimated organ dose is important. Furthermore, organ-at-risk (OAR) dose uncertainties cannot be eliminated and might affect the resulting NTCP model. Therefore, it is also of interest to study how OAR dose errors impact the NTCP modeling results. Purpose: To investigate how random delineation errors of the proximal bronchial tree, heart, and esophagus impact the estimated OAR dose, and to investigate how random errors in the doses used for dose-response modeling affect the estimated NTCPs. Methods: We investigated the impact of random delineation errors on the estimated OAR dose using the treatment plans of 39 patients treated with conventionally fractionated radiation therapy of non-small-cell lung cancer. Study-specific reference structures were defined by manually contouring the proximal bronchial tree, heart and esophagus. For each patient and organ, 120 reshaped structures were created by introducing random shifts and margins to the entire reference structure. The mean and near-maximum dose to the reference and reshaped structures were compared. In a separate investigation, the impact of random dose errors on the NTCP model was studied performing dose-response modeling with study sets containing treatment outcomes and OAR doses with and without introduced errors. Universal patient populations with defined population risks, dose-response relationships and distributions of OAR doses were used as ground truth. From such a universal population, we randomly sampled data sets consisting of OAR dose and treatment outcome into reference populations.Study sets of different sizes were created by repeatedly introducing errors to the OAR doses of each reference population. The NTCP models generated with dose errors were compared to the reference NTCP model of the corresponding reference population. Results: A total of 14 040 reshaped structures with random delineation errors were created. The delineation errors resulted in systematic mean dose errors of less than 1% of the prescribed dose (PD).Mean dose differences above 15% of PD and near-maximum doses differences above 25% of PD were observed for 211 and 457 reshaped structures, respectively. Introducing random errors to OAR doses used for dose-response modeling resulted in systematic underestimations of the median NTCP. For all investigated scenarios, the median differences in NTCP were within 0.1 percentage points (p.p.) when comparing different study sizes. Conclusions: Introducing random delineation errors to the proximal bronchial tree, heart and esophagus resulted in mean dose and near-maximum dose differences above 15% and 25% of PD, respectively. We did not observe an association between the dose level and the magnitude of the dose errors. For the scenarios investigated in this study, introducing random errors to OAR doses used for dose-response modeling resulted in systematic underestimations of the median NTCP for reference risks higher than the universal population risk. The median NTCP underestimation was similar for different study sizes, all within 0.1 p.p. [ABSTRACT FROM AUTHOR]

There is no authoritative characterization of the attributes of the hemolymph node (HLN) since Gibbes' first description in 1884. Early reports showed that HLN are found near the kidney in human and animals with the feature of numerous erythrocytes in sinuses. Subsequent studies mainly focused on anatomy and histology, such as the source, distribution, and quantity of erythrocytes in sinuses. Recent articles mentioned that the emergence of HLN was related to immunity, but there was no strong evidence to support this hypothesis. Therefore, it is still uncertain whether the HLN is an organ of anatomy, histology, or immunology. It has been found that the development of HLN could be elicited in the parathymic area by stimuli such as Escherichia coli, allogeneic breast cancer cells, and renal tissue that were injected/transplanted into the tail of rats in our pilot studies. In this study, the model of the HLN was established by transferring allogeneic renal tissue in the rat. Intrasinusoidal erythrocytes of the node were the component for producing a red macroscopic appearance, while macrophage-erythrocyte-lymphocyte rosettes were the major immunomorphological changes, reflecting the immune activity against the invasion of the allogeneic tissue within the node. Therefore, the HLN is an immunomorphological organ. [ABSTRACT FROM AUTHOR]

This article discusses ownership and property issues in three-dimensional (3D) bioprinting from the perspective of the tangible aspect of the technology. Many scholars have examined property issues in the intangible aspect of the technology, namely, the intellectual property issue. Since a major component of 3D bioprinting is cells taken from patients and donors, it is important to explore the right of ownership over the physical product, including cells used in the 3D bioprinting process and the 3D bioprinted organ itself. What is the extent of the donor's right over his/her cells taken for use in 3D bioprinting and even the 3D bioprinted organ - the product of those cells? For example, can the cell donor determine how his/her cells are used, or even who gets the 3D bioprinted organ? What rights does a person have over the commercial use of his/her cells or tissue for 3D bioprinting? [ABSTRACT FROM AUTHOR]

Steyn-Ross and coworkers describe the ex vivo quantification of tissue oxygen consumption by measuring oxygen partial pressure as a function of probe depth using thin slices of cortical brain tissue [[9]]. Eleven articles are published in the Special Issue, which deals with various tissue and organ regeneration questions or the modelling or summary of the research models used in this process. The recovery of cells after tissue and organ injury is a complex process. [Extracted from the article]

Tissue engineering (TE) is the multi-disciplinary approach to building 3D human tissue equivalents in the laboratory. The advancement of medical sciences and allied scientific disciplines have aspired to engineer human tissues for three decades. To date there is limited use of TE tissues/organs as replacement body parts in humans. This position paper outlines advances in engineering of specific tissues and organs with tissue-specific challenges. This paper outlines the technologies most successful for engineering tissues and key areas of advancement. [ABSTRACT FROM AUTHOR]

The development of new advanced constructs resembling structural and functional properties of human organs and tissues requires a deep knowledge of the morphological and biochemical properties of the extracellular matrices (ECM), and the capacity to reproduce them. Manufacturing technologies like 3D printing and bioprinting represent valuable tools for this purpose. This review will describe how morphological and biochemical properties of ECM change in different tissues, organs, healthy and pathological states, and how ECM mimics with the required properties can be generated by 3D printing and bioprinting. The review describes and classifies the polymeric materials of natural and synthetic origin exploited to generate the hydrogels acting as "inks" in the 3D printing process, with particular emphasis on their functionalization allowing crosslinking and conjugation with signaling molecules to develop bio-responsive and bio-instructive ECM mimics. [Display omitted] [ABSTRACT FROM AUTHOR]

G protein-coupled receptors (GPCRs) transfer extracellular signals across cell membranes by activating intracellular heterotrimeric G proteins. Several studies suggested G proteins as novel drug targets for the treatment of complex diseases, e.g., asthma and cancer. Recently, we developed specific radiotracers, [³H]PSB-15900-FR and [³H]PSB-16254-YM, for the Gαq family of G proteins by tritiation of the macrocyclic natural products FR900359 (FR) and YM-254890 (YM). In the present study, we utilized these potent radioligands to perform autoradiography studies in tissues of healthy mice, mouse models of disease, and human tissues. Specific binding was high, while non-specific binding was extraordinarily low, giving nearly identical results for both radioligands. High expression levels of Gαq proteins were detected in healthy mouse organs showing the following rank order of potency: kidney > liver > brain > pancreas > lung > spleen, while expression in the heart was low. Organ sub-structures, e.g., of mouse brain and lung, were clearly distinguishable. Whereas an acute asthma model in mice did not result in altered Gαq protein expressions as compared to control animals, a cutaneous melanoma model displayed significantly increased expression in comparison to healthy skin. These results suggest the future development of Gαq-protein-binding radio-tracers as novel diagnostics. [ABSTRACT FROM AUTHOR]

Cells are the basic unit of human organs that are not fully understood. The revolutionary advancements of optical imaging allowed us to observe single cells in whole organs, revealing the complicated composition of cells with spatial information. Therefore, in this review, we revisit the principles of optical contrast related to those biomolecules and the optical techniques that transform optical contrast into detectable optical signals. Then, we describe optical imaging to achieve three-dimensional spatial discrimination for biological tissues. Due to the milky appearance of tissues, the spatial information blurred deep in the whole organ. Fortunately, strategies developed in the last decade could circumvent this issue and lead us into a new era of investigation of the cells with their original spatial information. [ABSTRACT FROM AUTHOR]

By understanding and applying the physics of cellular self-assembly, scientists aim to predict tissue behaviors and accelerate the regeneration of human tissues and organs. [ABSTRACT FROM AUTHOR]

The ability to create complex three-dimensional cellular models that can effectively replicate the structure and function of human organs and tissues in vitro has the potential to revolutionize medicine. Such models could facilitate the interrogation of developmental and disease processes underpinning fundamental discovery science, vastly accelerate drug development and screening, or even be used to create tissues for implantation into the body. Realization of this potential, however, requires the recreation of complex biochemical, biophysical, and cellular patterns of 3D tissues and remains a key challenge in the field. Recent advances are being driven by improved knowledge of tissue morphogenesis and architecture and technological developments in bioengineering and materials science that can create the multidimensional and dynamic systems required to produce complex tissue microenvironments. In this article, we discuss challenges for in vitro models of tissues and organs and summarize the current state-of-the art in biomaterials and bioengineered systems that aim to address these challenges. This includes both top-down technologies, such as 3D photopatterning, magnetism, acoustic forces, and cell origami, as well as bottom-up patterning using 3D bioprinting, microfluidics, cell sheet technology, or composite scaffolds. We illustrate the varying ways that these can be applied to suit the needs of different tissues and applications by focussing on specific examples of patterning the bone-tendon interface, kidney organoids, and brain cancer models. Finally, we discuss the challenges and future prospects in applying materials science and bioengineering to develop high-quality 3D tissue structures for in vitro studies. [ABSTRACT FROM AUTHOR]

To study the pharmacokinetics and tissue distribution characteristics of Polygonatum sibiricum (P. sibiricum) polysaccharide administered orally and intravenously in rats, the latest quantitative analysis method was established where P. sibiricum polysaccharide was labeled with fluorescein isothiocyanate (FITC) in plasma and tissues. Quantitative analysis method of P. sibiricum polysaccharide in rat plasma and tissues was established by fluorescence spectrophotometry with FITC as a highly sensitive fluorescent molecular probe. The results showed that P. sibiricum polysaccharide was successfully labeled with FITC, and the degree of substitution was 0.55 %. Pharmacokinetic characteristics showed that oral administration (ig) and intravenous injection (iv) were consistent with the characteristics of two-compartment model. PRP-TYR-FITC administered orally was poorly absorbed in rats with low bioavailability. After a single ig and iv administration in rats for 8 h, P. sibiricum polysaccharide can be distributed in most tissues. The analysis results showed that P. sibiricum polysaccharide was distributed mostly in lung, kidney and liver for both routes of administration. When taking orally, the distribution pattern was: lung > liver > kidney > small intestine > stomach > heart > spleen > brain. When taking intravenously, the distribution pattern was: liver > lung > kidney > small intestine > heart > stomach > spleen > brain. Fluorescence labeling of P. sibiricum polysaccharide by FITC was successfully realized. This method was proved to be suitable for the study of pharmacokinetics and tissue distribution of P. sibiricum polysaccharide in rats. The above research lays foundation for further elucidating the clinical pharmacological mechanism of polysaccharide in P. sibiricum. • PRP was successfully labeled with new highly sensitive FITC firstly. • Pharmacokinetics of PRP in rats was studied for the first time. • The tissue distribution of PRP-TYR-FITC was studied by CLSM. [ABSTRACT FROM AUTHOR]

Total mercury (THg) concentrations were measured in wild alligators inhabiting a coastal marsh in southern Louisiana, to determine the tissue distribution of THg among various body organs and tissue compartments. Concentrations of THg in claws and dermal tail scutes were compared to those in blood, brain, gonad, heart, kidney, liver, and skeletal muscle to determine if the former tissues, commonly available by non-lethal sampling, could be used as measures of body burdens in various internal organs. Mercury was found in all body organs and tissue compartments. However, overall, THg concentrations measured in alligators were below the FDA action level for fish consumption and were comparable to previous data reported from southwestern Louisiana. Our results suggest consumption of meat from alligators found in this region may be of little public health concern. However, the extended period of time between sampling (in this study) and the present-day highlight the need for continuous, additional, and more recent sampling to ensure consumer safety. Total mercury concentrations were highest in the kidney (3.18 ± 0.69 mg/kg dw) and liver (3.12 ± 0.76 mg/kg dw). THg levels in non-lethal samples (blood, claws, and dermal tail scutes) were positively correlated with all tissue THg concentrations (blood: R2 = 0.513–0.988; claw: R2 = 0.347–0.637, scutes: R2 = 0.333–0.649). Because THg concentrations from blood, claws, and scutes were correlated with those of the internal organs, non-lethal sampling methods may be a viable method of estimating levels of THg in other body tissues. [ABSTRACT FROM AUTHOR]

The widespread use and increased exposure of nanoparticles call for technology to quantify their concentration and size distribution in biological matrices. As ex situ evaluation, facile extraction with high fidelity and efficiency is critical. In this work, single particle inductively coupled plasma mass spectrometry (spICP-MS) was used for nanoparticle number and distribution analysis, where a facile and highly efficient mechanically assisted alkaline digestion has been developed to extract nanoparticles at low alkali concentration. The optimization was performed using chicken tissues in vitro mixed with 30 nm gold nanoparticles, mixture of 30 nm and 60 nm gold nanoparticles, and 45 nm silver nanoparticles, respectively, which is, then, mechanically ground to form tissue homogenate and 2% TMAH is added. The nanoparticles are extracted with a recovery of more than 94% for all the spiked nanoparticle tissue samples. The extraction method has also been attempted to be applied to extract single-sized gold nanoparticles from various organs of mice mixed in vivo with the nanoparticles through intravenous injection, and led to consistent results with acid digestion. Mice injected intravenously with double-sized gold nanoparticle mixture were also studied, further showing that gold nanoparticles of 30 nm and 60 nm have no significant difference in their biodistribution in the same organ. To the best of our knowledge, this is the first attempt for multiple nanoparticles being extracted simultaneously and measured quantitatively from various organs, such as the heart, liver, spleen, lungs, and kidneys. We believe this method is beneficial to the safety assessment and toxicokinetics studies for nanoparticles in tissues. [ABSTRACT FROM AUTHOR]

Identifying body fluids and organ tissues is highly significant as they can offer crucial evidence in criminal investigations and aid the court in making informed decisions, primarily through evaluating the biological source and possibly at the activity level up to death or fatal damage. In this study, organ tissue-specific CpG markers were identified from Illumina's methylation EPIC array data of nine organ tissues, including epidermis, dermis, heart, skeletal muscle, blood, kidney, brain, lung, and liver, from autopsies of 10 Koreans. Through the validation test using 43 samples, 18 hypomethylation markers, with two markers for each organ tissue type, were selected to construct a SNaPshot assay. Two multiplex assays involving forward and reverse SBE primers were designed to help investigators accurately determine the organ origin of the analyzed tissue samples through repeated analysis of the same PCR products for markers. The developed multiplex demonstrated high accuracy, achieving 100.0 % correct detection of the presence of nine organ tissue types in 88 samples from autopsies of 10 Asians. However, two lung samples showed additional positive indications of the presence of blood. An interlaboratory comparison using 80 autopsy samples (heart, skeletal muscle, blood, kidney cortex, kidney medulla, brain, lung, and liver) from 10 individuals in Germany revealed overall comparable results with correct detection of the presence of eight organ tissue types in 92.5 % samples (74 of 80 samples). In the case of six samples, it was impossible to determine the correct tissue successfully due to drop-outs of unmethylation signals at target tissue marker loci. One of these lung samples revealed only non-intended off-target signals for blood. The observed differences might be due to differences in sample collection during routine autopsy, technical differences due to the PCR cycler, and the threshold used for signal calling. Indicating the presence of additional tissue type and off-target unmethylation signals seems alleviated by applying more stringent hypomethylation thresholds. Therefore, the developed SNaPshot multiplex assays will be valuable for forensic investigators dealing with organ tissue identification, as well as for prosecutors and defense aiming to establish the circumstances that occurred at the crime scene. • Organ tissue typing can be done successfully using tissue-specific DNA methylation markers. • Markers identified with the EPIC array can be used in a SNaPshot assay. • Interlaboratory comparison demonstrated successful implementation and applicability of the assay. • Assay validation prior application is needed as equipment and analytical threshold can impact detection and interpretation. [ABSTRACT FROM AUTHOR]

The article titled "Clay Sculpture-Inspired 3D Printed Microcage Module Using Bioadhesion Assembly for Specific-Shaped Tissue Vascularization and Regeneration" discusses a new method for creating tissue engineering grafts using 3D printing and adhesive hydrogels. The authors, Zhenxing Wang, Jiaming Sun, and their colleagues, demonstrate the effectiveness of this approach in building tissue engineering grafts in vivo. This innovative technique has the potential to revolutionize the field of organ replacement by enabling the construction of large-scale tissue engineering grafts. [Extracted from the article]

Understanding the inner morphology of intact tissues is one of the most competitive challenges in modern biology. Since the beginning of the twentieth century, optical tissue clearing (OTC) has provided solutions for volumetric imaging, allowing the microscopic visualization of thick sections of tissue, organoids, up to whole organs and organisms (for example, mouse or rat). Recently, tissue clearing has also been introduced in clinical settings to achieve a more accurate diagnosis with the support of 3D imaging. This review aims to give an overview of the most recent developments in OTC and 3D imaging and to illustrate their role in the field of medical diagnosis, with a specific focus on clinical applications. [ABSTRACT FROM AUTHOR]

Organ-on-a-chip technology aims to reproduce the key physiological features of human organs and tissues, even complex actions of multi-organ interaction. While organ-on-a-chips at single-organ level has made notable achievement during the last decade, multi-organ-on-a-chips, which manifests unique advantages, has started gathering attention only recently. In this viewpoint, we discuss the current status of organ-on-a-chip technology, with a specific emphasis on multi-organ-on-a-chip. Key technological advances contributing to the maturation of the field, and challenges that need to be addressed before wider adoption in relevant fields are discussed. We will share our perspectives on how the multi-organ-on-a-chip can improve the drug development process. [ABSTRACT FROM AUTHOR]

8‐Prenylnaringenin (8‐PN), a hop flavonoid, is a promising food substance with health benefits. Compared with nonprenylated naringenin, 8‐PN exhibits stronger estrogenic activity and prevents muscle atrophy. Moreover, 8‐PN prevents hot flushes and bone loss. Considering that prenylation reportedly improves the bioavailability of flavonoids, we compared the parameters related to the bioavailability [pharmacokinetics and tissue distribution in C57/BL6 mice, binding affinity to human serum albumin (HSA), and cellular uptake in HEK293 cells] of 8‐PN and its mother (non‐prenylated) compound naringenin. C57/BL6 mice were fed an 8‐PN or naringenin mixed diet for 22 days. The amount of 8‐PN (nmol/g tissue) in the kidneys (16.8 ± 9.20), liver (14.8 ± 2.58), muscles (3.33 ± 0.60), lungs (2.07 ± 0.68), pancreas (1.80 ± 0.38), heart (1.71 ± 0.27), spleen (1.36 ± 0.29), and brain (0.31 ± 0.09) was higher than that of naringenin. A pharmacokinetic study in mice demonstrated that the Cmax of 8‐PN (50 mg/kg body weight) was lower than that of naringenin; however, the plasma concentration of 8‐PN 8 h after ingestion was higher than that of naringenin. The binding affinity of 8‐PN to HSA and cellular uptake in HEK293 cells were higher than those of naringenin. 8‐PN bioavailability features assessed in mouse or human model experiments were obviously different from those of naringenin. [ABSTRACT FROM AUTHOR]

Hepatitis B virus (HBV) infection is a worldwide health burden. Metabolomics analysis has revealed HBV-induced metabolism dysregulation in liver tissues and hepatocytes. However, as an infectious disease, the tissue-specific landscape of metabolic profiles of HBV infection remains unclear. To fill this gap, we applied untargeted nuclear magnetic resonance (NMR) metabolomic analysis of the heart, liver, spleen, lung, kidney, pancreas, and intestine (duodenum, jejunum, ileum) in HBV-transgenic mice and their wild-type littermates. Strikingly, we found systemic metabolic alterations induced by HBV in liver and extrahepatic organs. Significant changes in metabolites have been observed in most tissues of HBV-transgenic mice, except for ileum. The metabolic changes may provide novel therapeutic targets for the treatment of HBV infection. Moreover, tissue-specific metabolic profiles could speed up the study of HBV induced systemic metabolic reprogramming, which could help follow the progression of HBV infection and explain the underlying pathogenesis. [ABSTRACT FROM AUTHOR]

Tissue engineering (TE) aims to generate bioengineered constructs which can offer a surgical treatment for many conditions involving tissue or organ loss. Construct generation must be guided by suitable assessment tools. However, most current tools (e.g. histology) are destructive, which restricts evaluation to a single-2D anatomical plane, and has no potential for assessing constructs prior to or following their implantation. An alternative can be provided by laboratory-based x-ray phase contrast computed tomography (PC-CT), which enables the extraction of 3D density maps of an organ's anatomy. In this work, we developed a semi-automated image processing pipeline dedicated to the analysis of PC-CT slices of oesophageal constructs. Visual and quantitative (density and morphological) information is extracted on a volumetric basis, enabling a comprehensive evaluation of the regenerated constructs. We believe the presented tools can enable the successful regeneration of patient-specific oesophagus, and bring comparable benefit to a wide range of TE applications. Phase contrast computed tomography (PC-CT) is an imaging modality which generates high resolution volumetric density maps of biological tissue. In this work, we demonstrate the use of PC-CT as a new tool for guiding the progression of an oesophageal tissue engineering (TE) protocol. Specifically, we developed a semi-automated image-processing pipeline which analyses the oesophageal PC-CT slices, extracting visual and quantitative (density and morphological) information. This information was proven key for performing a comprehensive evaluation of the regenerated constructs, and cannot be obtained through existing assessment tools primarily due to their destructive nature (e.g. histology). This work paves the way for using PC-CT in a wide range of TE applications which can be pivotal for unlocking the potential of this field. [Display omitted] [ABSTRACT FROM AUTHOR]

Vertebrate organs are arranged in a stereotypic, species-specific position along the animal body plan. Substantial morphological variation exists between related species, especially so in the vastly diversified teleost clade. It is still unclear how tissues, organs and systems can accommodate such diverse scaffolds. Here, we use the distinctive arrangement of neuromasts in the posterior lateral line (pLL) system of medaka fish to address the tissue-interactions defining a pattern. We show that patterning in this peripheral nervous system is established by autonomous organ precursors independent of neuronal wiring. In addition, we target the keratin 15 gene to generate stuck-in-the-midline (siml) mutants, which display epithelial lesions and a disrupted pLL patterning. By using siml/wt chimeras, we determine that the aberrant siml pLL pattern depends on the mutant epithelium, since a wild type epithelium can rescue the siml phenotype. Inducing epithelial lesions by 2-photon laser ablation during pLL morphogenesis phenocopies siml genetic mutants and reveals that epithelial integrity defines the final position of the embryonic pLL neuromasts. Our results using the medaka pLL disentangle intrinsic from extrinsic properties during the establishment of a sensory system. We speculate that intrinsic programs guarantee proper organ morphogenesis, while instructive interactions from surrounding tissues facilitates the accommodation of sensory organs to the diverse body plans found among teleosts. [Display omitted] • Epithelial integrity defines pLL patterning in medaka. • Patterning occurs regardless of nerve connectivity. • Primary organs' migration is independent of one another and depends on local cues. • Secondary organs' patterning is robust even on aberrant pLL initial conformation. • Hierarchical organization could be relevant for pLL adaption to diverse body plan. [ABSTRACT FROM AUTHOR]

Modern science is developing at a rapid pace and today, especially during the epidemic situation, scientific events are in demand, which allow us to consider topical issues that interest participants from different areas, individual ways to solve the same problem, listen to lectures by invited experts, and establish valuable contacts. On May 27-31, 2021 in Almaty, Kazakhstan, on the premises of the al-Farabi Kazakh National University, Higher School of Medicine, the Department of Fundamental Medicine, and the Eurasian Association of Morphologists held the XXVII International Symposium of Morphological Sciences ISMS 2021. This Morphological Congress was held, the first time, in 1971, in Mexico City, with the subsequent editions organized every two years in Argentina, Israel, the USA, Brazil, Portugal, Italy, Japan and many other countries (https://www.symposiamorphologica.com/). The decision to hold the Symposium in 2020 in Kazakhstan was made at the meeting of the International Committee of Symposia on Morphological Sciences (ICSMS) on June 5, 2018 in Prague (Czech Republic) as a part of the XXVI International Symposium of Morphological Sciences. The advantage of votes over other candidate countries (South Africa, Argentina) allowed Kazakhstan to take a huge responsibility for holding this Forum. [ABSTRACT FROM AUTHOR]

[Display omitted] • The state-of-the-art of 3D bioprinting is comprehensively reviewed with emphasis on design and processing aspects. • Major applications in the biomedical area, including the repair of bone, soft tissues and organs, are considered. • The current limitations and the latest evolutions of bioprinting-based strategies are examined. • Existing results and new horizons are discussed to provide a picture being useful to both senior and early-stage researchers. 3D bioprinting techniques have emerged as a flexible tool in tissue engineering and regenerative medicine to fabricate or pattern functional 3D bio-structures with precise geometric designs, bridging the divergence between engineered and natural tissue constructs. A significantly increasing development has been achieved in understanding the relationship between the 3D-printing process and the structures, properties, and applications of the objects created. The ongoing advancement of novel biomaterial inks has enabled manufacturing of models and in vitro implants capable of achieving some level of success in preclinical trials. Remarkable progress in cell biology and biology-inspired computational design has assisted in achieving the latest milestone with planned tissue- or organ-like constructs having specific levels of functionality. However, biofabricated constructs still have a long way to go before reaching clinics. This review presents a picture of 3D bioprinting in the context of tissue engineering and regenerative medicine, with focus on biomaterials-related and design-centred aspects. Biomedical applications are described in detail in relation to major tissues or organs considered in the human body. Current technical limitations, challenges, future prospects and improvements are critically outlined and discussed. [ABSTRACT FROM AUTHOR]

The article titled "Retraction: Mesenchymal Stromal Cells for Tissue-Engineered Tissue and Organ Replacements" discusses the retraction of a review article published in Transplant International in 2012. The retraction was prompted by the discovery that the article cited another paper from the same authors, which had been retracted due to falsification of data. The investigation by the Swedish National Board for Assessment of Research Misconduct confirmed the falsification. The review article in question claimed that tissue engineering had already achieved successful human tissue and organ replacements, citing the retracted paper as evidence. The editor-in-chief of Transplant International retracted the review article based on these findings. [Extracted from the article]

INTRODUCTION: This talk will discuss the applications of tissue engineering in two areas of medicine: regenerative engineering of whole organs at the clinical scale, and modelling of diseases and therapeutic modalities using microsized “organs on chip” platforms. EXPERIMENTAL: Engineering of human tissues involves the use of human stem cells (in most cases derived from a sample of blood) and two engineering components that are “instructing” the cells how to form a specific tissue. Th first component is a tissue specific biomaterial scaffold that serves as a structural and logistic template for tissue formation. The second component is the bioreactor designed to provide homeostasis and tissue-specific molecular and physical regulatory factors, as well as sensing and imaging modalities necessary to monitor and measure tissue development and function. In all cases, we aim to recapitulate the cell niches, using bioengineering tools. RESULTS AND DISCUSSION: To illustrate the state of the art in the field and reflect on the current challenges and opportunities, this talk will discuss representative examples of whole organ engineering and organs-on chip models of injury, disease and regeneration. At the clinical scale, the goal is to achieve regeneration by treating the whole organ damaged by injury of disease. We will discuss regenerative engineering of a joint (that can be engineered de novo), and the lung and heart (that are being regenerated with the use of therapeutic cells). In organs-on-chip platforms, microsized human tissues are matured to adult-like phenotypes and functionally linked by vascular perfusion containing circulating cells and factors. At the micro-scale, we will focus on organs on chip models of cancer metastasis, radiation damage, and side effects of some common drugs. Finally, we will discuss the key challenges the field is currently facing. CONCLUSIONS: Tissue engineering is increasingly successful in recapitulating human physiology in health and disease, in patient-specific settings, supporting the development of high-fidelity research models and treatment modalities tailored to the specific patient. [ABSTRACT FROM AUTHOR]

• A systematic assessment of 18 potential reference genes (RGs) in 10 different ovine tissues was carried out to identify internal control genes for qPCR analysis. • Four algorithms: geNorm, NormFinder, BestKeeper, and Delta Ct (ΔCt), were employed to rank the stability of these RGs. • RefFinder was used for a comprehensive ranking, identifying ACTB, PPIB, BACH1 , and B2M as the most stable RGs. • RPS9, RPS15 , and PGK1 showed variable expression across different tissues. • Validation was performed using qPCR analysis of four target genes in the skin from two sheep breeds. Quantitative PCR (qPCR) is a widely-used technique for quantifying the expression of target genes across various tissues, as well as under different pathological and physiological conditions. One of the challenges associated with this method is the need to identify optimal reference genes (RGs) that maintain consistent expression levels under diverse experimental settings, thereby ensuring accurate biological interpretation. In this study, we conducted a thorough analysis of 18 candidate RGs (ACTB , BACH1 , B2M , GAPDH , HMBS , HPRT1 , PGK1 , PPIA , PPIB , RPLP0 , RPL19 , RPS9 , RPS15 , RPS28 , SDHA , TBP , UXT , and YWHAZ) across 10 ovine tissues (muscle, skin, kidney, liver, intestine, rumen, lung, testis, heart, and spleen) obtained from five individual sheep. We aimed to identify genes with stable expression across these tissues. A literature-based survey helped us shortlist candidate genes representing various functional classes from multiple livestock species. We employed four algorithms: geNorm, NormFinder, BestKeeper, and Delta Ct (ΔCt), to rank these genes based on their stability. A consistent trend in the rankings was observed across these different algorithms. RefFinder was then used for a comprehensive ranking, integrating the outputs from the various methods. ACTB, PPIB, BACH1 , and B2M emerged as the most stable RGs, while RPS9, RPS15 , and PGK1 displayed variable expression. We validated our findings through qPCR analysis of four target genes (ACTN2, CRYAB, DLK1 , and TRIM54) in the skin samples from two different sheep breeds. Based on these results, we recommend ACTB, PPIB, BACH1 , and B2M as reliable internal control genes for qPCR experiments involving diverse ovine tissues. [ABSTRACT FROM AUTHOR]

Background: Coronavirus disease (COVID-19) is the pandemic caused by SARS-CoV-2 that has caused more than 2.2 million deaths worldwide. We summarize the reported pathologic findings on biopsy and autopsy in patients with severe/fatal COVID-19 and documented the presence and/or effect of SARS-CoV-2 in all organs. Methods and findings: A systematic search of the PubMed, Embase, MedRxiv, Lilacs and Epistemonikos databases from January to August 2020 for all case reports and case series that reported histopathologic findings of COVID-19 infection at autopsy or tissue biopsy was performed. 603 COVID-19 cases from 75 of 451 screened studies met inclusion criteria. The most common pathologic findings were lungs: diffuse alveolar damage (DAD) (92%) and superimposed acute bronchopneumonia (27%); liver: hepatitis (21%), heart: myocarditis (11.4%). Vasculitis was common only in skin biopsies (25%). Microthrombi were described in the placenta (57.9%), lung (38%), kidney (20%), Central Nervous System (CNS) (18%), and gastrointestinal (GI) tract (2%). Injury of endothelial cells was common in the lung (18%) and heart (4%). Hemodynamic changes such as necrosis due to hypoxia/hypoperfusion, edema and congestion were common in kidney (53%), liver (48%), CNS (31%) and GI tract (18%). SARS-CoV-2 viral particles were demonstrated within organ-specific cells in the trachea, lung, liver, large intestine, kidney, CNS either by electron microscopy, immunofluorescence, or immunohistochemistry. Additional tissues were positive by Polymerase Chain Reaction (PCR) tests only. The included studies were from numerous countries, some were not peer reviewed, and some studies were performed by subspecialists, resulting in variable and inconsistent reporting or over statement of the reported findings. Conclusions: The main pathologic findings of severe/fatal COVID-19 infection are DAD, changes related to coagulopathy and/or hemodynamic compromise. In addition, according to the observed organ damage myocarditis may be associated with sequelae. [ABSTRACT FROM AUTHOR]

Purpose: We have previously reported on a polymeric micellar formulation of Cyclosporine A (CyA) based on poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO5K-b-PCL13K) capable of changing drug biodistribution and pharmacokinetic profile following intravenous administration. The objective of the present study was to explore the potential of this formulation in changing the tissue distribution and pharmacokinetics of the encapsulated CyA following oral administration making comparisons with Sandimmune®. Methods: The in vitro CyA release and stability CyA-loaded PEO-b-PCL micelles (CyA-micelles) were evaluated in biorelevant media. The pharmacokinetics and tissue distribution of orally administered CyA-micelles or Sandimmune® and tissue distribution of traceable Cyanine-5.5 (Cy5.5)-conjugated PEO-b-PCL micelles were then investigated in healthy rats. Results: CyA-micelles showed around 60–70% CyA release in simulated intestinal and gastric fluids within 24 h, while Sandimmune® released its entire CyA content in the simulated intestinal fluid. CyA-micelles and Sandimmune® showed similar pharmacokinetics, but different tissue distribution profile in rats. In particular, the calculated AUC for CyA-micelles was higher in liver, comparable in heart, and lower in spleen, lungs, and kidneys when compared to that for Sandimmune®. Conclusions: The results point to the influence of excipients in Sandimmune® on CyA disposition and more inert nature of PEO-b-PCL micelles in defining CyA biological interactions. [ABSTRACT FROM AUTHOR]

This work focuses on the development, validation and application of an analytical method for the determination of twenty organochlorine pesticides (OCPs) in human tissues using salting-out liquid–liquid extraction and dispersive liquid–liquid microextraction for sample preparation and gas chromatography–mass spectrometry to analyze the obtained extracts. Measurement of the concentration levels of these toxics in tissues can be used to assess the risk of the population to exposure. The linearity of the proposed method was verified in the 10–1,000 ng/g range. The sensitivity was evaluated calculating the limits of detection (LODs) for 20 OCPs (α-, β-, γ- and δ-hexachlorocyclohexane (HCH), α- and β-endosulfan, endosulfan sulfate, aldrin, dieldrin, endrin, endrin ketone, endrin aldehyde, α- and γ-chlordane, 4,4′-dichlorodiphenyltrichloroethane, 4,4′-dichlorodiphenyldichloroethylene (DDE), 4,4′-dichlorodiphenyldichloroethane, heptachlor, heptachlor epoxide and methoxychlor), most of them being found between 1.0 and 16 ng/g. The intra- and interday precisions were <12% for relative standard deviation values. The accuracy of the method was evaluated by recovery studies, which gave recovery percentages in the 85–109% range. Seven different tissues (liver, kidney, heart, spleen, lung, brain and abdominal fat) from eight autopsies were analyzed, and only three cases were seen to have β-HCH and 4,4′-DDE in abdominal fat, while 4,4′-DDE was also detected in the heart of one case. The rest of the samples were free of the studied OCPs at least above the corresponding LODs. [ABSTRACT FROM AUTHOR]

A modified calibration curve method based on the combination of standard addition and traditional calibration curve methods was employed for the quantification of Prussian blue nanoparticles in rats in the presence of endogenous iron interferences. The assay was performed using inductively coupled plasma – optical emission spectrometry (ICP-OES) with yttrium as the internal standard, and validated in biomatrices including liver, heart, kidneys, lungs, spleen and whole blood. For the liver tissue, the intra-day and inter-day precision were 7.84% or less, and the accuracy was between 99.88% and 102.37%. For kidneys, lungs, heart, spleen, and blood, at each exo-additive level from 0.4 to 3.2 µg/mL, the intra-day accuracy was between 98.74% and 102.09%, and the intra-day precision was 6.17% or less. For the addition of no analyte, the intra-day accuracy was between 96.42% and 107.52%, and the intra-day precision was 15.67% or less. The stability was investigated at 25 °C for 24 h and 4 °C for 15 days in liver standard addition samples, and no significant degradation occurred under these conditions. This method was successfully applied to the preliminary pharmacokinetics and tissue distribution study of Prussian blue nanoparticles in rats. This approach may also be applied to the quantification of other ferruginous materials in the biological matrices with endogenous iron. [ABSTRACT FROM AUTHOR]

The article offers information on Foramen caecum that is an opening in an organ or tissue ending blindly. Topics include examines that the Foramen caecum ossis frontalis in the fossa cranii anterior, rostral of the crista frontalis; and considered that the embryonic duct thyreoglossus, a foramen caecum persists behind the sulcus terminalis at the transition to the base of the tongue.

Rcd4 is a poorly characterized Drosophila centriole component whose mammalian counterpart, PPP1R35, is suggested to function in centriole elongation and conversion to centrosomes. Here, we show that rcd4 mutants exhibit fewer centrioles, aberrant mitoses, and reduced basal bodies in sensory organs. Rcd4 interacts with the C-terminal part of Ana3, which loads onto the procentriole during interphase, ahead of Rcd4 and before mitosis. Accordingly, depletion of Ana3 prevents Rcd4 recruitment but not vice versa. We find that neither Ana3 nor Rcd4 participates directly in the mitotic conversion of centrioles to centrosomes, but both are required to load Ana1, which is essential for such conversion. Whereas ana3 mutants are male sterile, reflecting a requirement for Ana3 for centriole development in the male germ line, rcd4 mutants are fertile and have male germ line centrioles of normal length. Thus, Rcd4 is essential in somatic cells but is not absolutely required in spermatogenesis, indicating tissue-specific roles in centriole and basal body formation. [ABSTRACT FROM AUTHOR]

Biomedical engineers are at the forefront of developing novel treatments to improve human health, however, many products fail to translate to clinical implementation. In vivo pre-clinical animal models, although the current best approximation of complex disease conditions, are limited by reproducibility, ethical concerns, and poor accurate prediction of human response. Hence, there is a need to develop physiologically relevant, low cost, scalable, and reproducible in vitro platforms to provide reliable means for testing drugs, biomaterials, and tissue engineered products for successful clinical translation. One emerging approach of developing physiologically relevant in vitro models utilizes decellularized tissues/organs as biomaterial platforms for 2D and 3D models of healthy and diseased tissue. Decellularization is a process that removes cellular content and produces tissue-specific extracellular matrix scaffolds that can more accurately recapitulate an organ/tissue's native microenvironment compared to other natural or synthetic materials. Decellularized tissues hold enormous potential for in vitro modeling of various disease phenotypes and tissue responses to drugs or external conditions such as aging, toxin exposure, or even implantation. In this review, we highlight the need for in vitro models, the advantages and limitations of implementing decellularized tissues, and considerations of the decellularization process. We discuss current research efforts towards applying decellularized tissues as platforms to generate in vitro models of healthy and diseased tissues, and where we foresee the field progressing. A variety of organs/tissues are discussed, including brain, heart, kidney, large intestine, liver, lung, skeletal muscle, skin, and tongue. Many biomedical products fail to reach clinical translation due to animal model limitations. Development of physiologically relevant in vitro models can provide a more economic, scalable, and reproducible means of testing drugs/therapeutics for successful clinical translation. The use of decellularized tissues as platforms for in vitro models holds promise, as these scaffolds can effectively replicate native tissue complexity, but is not widely explored. This review discusses the need for in vitro models, the promise of decellularized tissues as biomaterial substrates, and the current research applying decellularized tissues towards the creation of in vitro models. Further, this review provides insights into the current limitations and future of such in vitro models. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Lyophilization is a practical method for product storage and transportation; it commonly is used in the food and pharmaceutical industries. Lyophilization also is used for preserving biological samples such as serum, plasma and animal tissues. We found that lyophilization does not affect the stability of RNAs and proteins in tissue samples. To investigate histological characteristics, we prepared lyophilized tissues for paraffin sectioning and hematoxylin and eosin (H & E) staining. We also measured water loss from organs during lyophilization. We used immunohistochemistry of frozen brain sections to identify potential protective effects of three concentrations of sucrose, glucose and trehalose against the effects of lyophilization. H & E staining revealed vacuoles in heart, lung, liver, kidney, spleen and brain after lyophilization without pretreatments, especially heart and kidney. We found that 10% solutions of sucrose, glucose and trehalose helped preserve tissue morphology. Immunohistochemistry of frozen brain tissue showed that 10% glucose and 30% sucrose preserved cellular characteristics and immunogenicity following lyophilization. Lyophilization removed > 70% of the water from organs, and lyophilized tissues without protectants were not suitable for histological study. Overall, we found that 10% glucose helped preserve both optimal tissue morphology and immunogenicity of freeze-dried tissue. [ABSTRACT FROM AUTHOR]