Key Organ Research Articles

Development of Germ Cell Isolation and Optimal Cryopreservation Method for Lissachatina fulica (L. fulica)

This study aims to develop an optimized method for cryopreserving the germ cells of Lissachatina fulica (L. fulica) using vitrification, as an alternative approach for conserving endangered snail species. First, we isolated several key reproductive organs, including the sperm oviduct, albumen gland, hermaphrodite gland (ovotestis), and hermaphrodite duct from L. fulica. When the ovotestis was finely chopped, numerous sperm with long tails and distinct heads were observed. The staining of sperm nuclei was confirmed using Hoechst 33342 dye. Since the hermaphrodite gland, referred to as the ovotestis, contains both male and female germ cells, we performed tissue staining on the ovotestis using hematoxylin and eosin (H&E) dye. H&E staining of the ovotestis revealed numerous oval-shaped acini containing sperm and early germ cells. Spermatocytes and spermatids were observed within distinct boundaries, with mature sperm appearing following spermatogenesis. To preserve the species of the L. fulica, we introduced vitrification technology to cryopreserve its reproductive organs. The non-vitrification group showed an average cell viability of 96.6%, while the vitrification group had 86.8% after thawing. This study presents a reliable cryopreservation protocol for L. fulica, with potential applications for other endangered snails, supporting conservation efforts to preserve genetic resources and biodiversity.

A coronaviral pore-replicase complex links RNA synthesis and export from double-membrane vesicles.

Coronavirus-infected cells contain double-membrane vesicles (DMVs) that are key for viral RNA replication and transcription, perforated by hexameric pores connecting the vesicular lumen to the cytoplasm. How pores form and traverse two membranes, and how DMVs organize RNA synthesis, is unknown. Using structure prediction and functional assays, we show that the nonstructural viral membrane protein nsp4 is the key pore organizer, spanning the double membrane and forming most of the pore lining. Nsp4 interacts with nsp3 on the cytoplasmic side and with the viral replicase inside the DMV. Newly synthesized mRNAs exit the DMV into the cytoplasm, passing through a narrow ring of conserved nsp4 residues. Steric constraints imposed by the ring predict that modified nucleobases block mRNA transit, resulting in broad-spectrum anticoronaviral activity.

Development and internal validation of prediction model for rebleeding within one year after endoscopic treatment of cirrhotic varices: consideration from organ-based CT radiomics signature

BackgroundRebleeding after endoscopic treatment for esophagogastric varices (EGVs) in cirrhotic patients remains a significant clinical challenge, with high mortality rates and limited predictive tools. Current methods, relying on clinical indicators, often lack precision and fail to provide personalized risk assessments. This study aims to develop and validate a novel, non-invasive prediction model based on CT radiomics to predict rebleeding risk within one year of treatment, integrating radiomic features from key organs and clinical data.Methods123 patients were enrolled and divided into rebleeding (n = 44) and non-bleeding group (n = 79) within 1 year after endoscopic treatment of EGVs. The liver, spleen, and the lower part of the esophagus were segmented and the extracted radiomics features were selected to construct liver/spleen/esophagus radiomics signatures based on logistic regression. Clinic-radiomics combined models and multi-organ combined radiomics models were constructed based on independent model scores using logistic regression. The model performance was evaluated by ROC analysis, calibration and decision curves. The continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI) indices were analyzed.ResultsThe clinical-liver combined model had the highest AUC of 0.931 (95% CI: 0.887–0.974), which was followed by the liver-based model with AUC of 0.891 (95% CI: 0.835–0.74). The decision curves also showed that the clinical-liver combined model afforded a greater net benefit compared to other models within the threshold probability of 0.45 to 0.80. Significant improvements in discrimination (IDI, P < 0.05) and reclassification (NRI, P < 0.05) were obtained for clinical-liver combined model compared with the independent ones.ConclusionThe independent and combined liver-based CT radiomics models performed well in predicting rebleeding within 1 year after endoscopic treatment of EGVs.

Effect of soil and community factors on the yield and medicinal quality of Artemisia argyi growth at different altitudes of the Funiu mountain

Altitude and ecological factors significantly influence plant growth and the accumulation of secondary metabolites. However, current research on the impact of altitude and ecological factors on the yield and medicinal quality of Artemisia argyi (A. argyi) is limited. This study established sampling sites in wild populations of A. argyi across seven altitude ranges on Funiu Mountain. We quantified the yield, output rate of moxa, and key medicinal ingredients. Additionally, we analyzed the response of yield and medicinal quality of wild A. argyi populations to various ecological factors at different altitudes. The results showed that wild populations of A. argyi exhibited higher yields and medicinal quality at altitudes below 500 m. Yield was positively correlated with higher soil total nitrogen (TN) content and lower soil total phosphorus (TP) content, while the improvements in medicinal quality were positively associated with higher population density and lower contents of both soil TN and TP. The variation in soil C/N, C/P, and N/P ratios across different altitudes was substantial, affecting soil mineralization and subsequently influencing the absorption of mineral elements by A. argyi. Notably, the phosphorus content in leaves and stems was negatively correlated with yield and medicinal quality, respectively. In contrast, the accumulation of nitrogen, phosphorus, and potassium in leaves was positively correlated with yield. The differences in the primary medicinal ingredients between the leaves and stems of A. argyi were maximum at altitudes below 500 m. The contents of neochlorogenic acid and cryptochlorogenic acid in both leaves and stems showed a significant positive correlation. In the principal component analysis, the primary medicinal ingredients from the leaves contributed more significantly to the overall quality than those from stems. These results suggest that A. argyi is best suited for cultivation at altitudes below 500 m. Population density and the soil’s TN and TP contents play a crucial role in determining the yield and medicinal quality of A. argyi. Futhermore, the medicinal quality of A. argyi is more indicative of the main medicinal ingredients found in the leaves, while the stems also serve as a key organ for accumulating flavonoids and phenolic acids.

Ammonia Exposure-Induced Immunological Damage in Chicken Lymphoid Organs via TLR-7/MYD88/NF-κB Signaling Pathway and NLRP3 Inflammasome Activation.

Ammonia (NH3) is a hazardous gas that pollutes the environment and causes irritation. Its harmful effects on chickens, including its impact on their immune system, have previously been observed. However, the mechanism by which NH3 exposure causes immune system disorders in chickens remains unclear. The bursa of Fabricius (BF) and thymus are the two main lymphoid organs responsible for the proliferation, differentiation, and selection of B- and T-lymphocytes, both critical for the innate immune response of the host. In this study, we investigated the mechanism of NH3-induced immune dysregulation in broiler chickens. Transmission electron microscopy (TEM) revealed swollen mitochondria and breakage of the large crista lining, membrane deformation, chromatin condensation, increased vacuolation, and blood vessel spasms in the NH3-exposed BF and thymus tissues. Immunofluorescent analysis showed clustering of CD4+ and CD8+ cells, indicating an active immune response to NH3 exposure. Furthermore, NH3 exposure enhanced the mRNA expressions of Toll-like receptor 7 (TLR-7), myeloid differentiation primary response 88 (MYD88), and nuclear factor-kappa B (NF-κB), along with their proteins, and led to activation of the TLR-7/MyD88/NF-κB signaling pathway and NLRP3 inflammasome in chicken thymus tissues. Both mRNA and protein levels of key inflammation-related genes and proteins were upregulated in the NH3-treated group, highlighting a robust inflammatory response due to NH3 exposure. The specific findings of significant structural damage to key lymphoid organs and activation of inflammatory pathways in broiler chickens upon NH3 exposure can provide guidance for future, targeted therapies to improve poultry health.

A latent Axin2+/Scx+ progenitor pool is the central organizer of tendon healing

A tendon’s ordered extracellular matrix (ECM) is essential for transmitting force but is also highly prone to injury. How tendon cells embedded within and surrounding this dense ECM orchestrate healing is not well understood. Here, we identify a specialized quiescent Scx+/Axin2+ population in mouse and human tendons that initiates healing and is a major functional contributor to repair. Axin2+ cells express stem cell markers, expand in vitro, and have multilineage differentiation potential. Following tendon injury, Axin2+-descendants infiltrate the injury site, proliferate, and differentiate into tenocytes. Transplantation assays of Axin2-labeled cells into injured tendons reveal their dual capacity to significantly proliferate and differentiate yet retain their Axin2+ identity. Specific loss of Wnt secretion in Axin2+ or Scx+ cells disrupts their ability to respond to injury, severely compromising healing. Our work highlights an unusual paradigm, wherein specialized Axin2+/Scx+ cells rely on self-regulation to maintain their identity as key organizers of tissue healing.

USP15 inhibits hypoxia-induced IL-6 signaling by deubiquitinating and stabilizing MeCP2.

Methyl-CpG binding protein 2 (MeCP2) is an important X-linked DNA methylation reader and a key heterochromatin organizer. The expression level of MeCP2 is crucial, as indicated by the observation that loss-of-function mutations of MECP2 cause Rett syndrome, whereas an extra copy spanning the MECP2 locus results in MECP2 duplication syndrome, both being progressive neurodevelopmental disorders. Our previous study demonstrated that MeCP2 protein expression is rapidly induced by renal ischemia-reperfusion injury (IRI) and protects the kidney from IRI through transcriptionally repressing the interleukin-6 (IL-6)/signal transducer and activator of transcription 3 signaling pathway. However, the mechanisms underlying the upregulation of MeCP2 have remained elusive. Here, by using two hypoxia cell models, hypoxia and reoxygenation and cobalt chloride stimulation, we confirmed that the removal of lysine 48-linked ubiquitination from MeCP2 prevented its proteasome-dependent degradation under hypoxic conditions. Through unbiased screening based on a deubiquitinating enzymes library, we identified ubiquitin-specific protease 15 (USP15) as a stabilizer of MeCP2. Further studies revealed that USP15 could attenuate hypoxia-induced MeCP2 degradation by cleaving lysine 48-linked ubiquitin chains from MeCP2, primarily targeting its C-terminal domain. Consistently, USP15 inhibited hypoxia-induced signal transducer and activator of transcription 3 activation, resulting in reduced transcription of IL-6 downstream genes. In summary, our study reveals an important role for USP15 in the maintenance of MeCP2 stability and the regulation of IL-6 signaling.

Associations Between Prenatal Vitamin D and Placental Gene Expression

BackgroundVitamin D is a hormone regulating gene transcription. Prenatal vitamin D has been linked to immune and vascular function in the placenta, a key organ of pregnancy. Transcriptome-wide RNA-sequencing can provide a more complete representation of the placental effects of vitamin D. ObjectiveWe investigated the association between prenatal vitamin D levels and placental gene expression in a large, prospective pregnancy cohort. MethodsParticipants were recruited in Shelby County, Tennessee in the Conditions Affecting Neurocognitive Development and Learning in Early childhood (CANDLE) study. Vitamin D (plasma total 25-hydroxyvitatmin D, [25(OH)D]) was measured at mid-pregnancy (16-28 weeks) and delivery. RNA was sequenced from placental samples collected at birth. We identified differentially expressed genes (DEGs) using adjusted linear regression models. We also conducted weighted gene co-expression network analysis (WGCNA). ResultsThe median 25(OH)D of participants was 21.8 ng/mL at mid-pregnancy (N=774, IQR: 15.4-26.5 ng/mL) and 23.6 ng/mL at delivery (N=753, IQR: 16.8-29.1 ng/mL). Placental expression of 17 DEGs was associated with 25(OH)D at mid-pregnancy, but only 1 DEG was associated with 25(OH)D at delivery. DEGs were related to energy metabolism, cytoskeletal function, and transcriptional regulation. We identified 2 WGCNA gene modules whose expression was associated with 25(OH)D at mid-pregnancy and 1 module associated with 25(OH)D at delivery. These modules were enriched for genes related to mitochondrial and cytoskeletal function and were regulated by transcription factors including ARNT2 and FOSL2. We also identified 12 modules associated with 25(OH)D in females and 1 module in males. Conclusions25(OH)D during mid-pregnancy, but not at delivery, is associated with placental gene expression at birth. Future research is needed to investigate a potential role of vitamin D in modulating placental mitochondrial metabolism, intracellular transport, and transcriptional regulation during pregnancy.

A Minimal PBPK Model Describes the Differential Disposition of Silica Nanoparticles In Vivo.

Nanoparticles (NPs) have emerged as promising candidates for drug delivery due to their tunable physical and chemical properties. Among these, silica nanoparticles (SiNPs) are particularly valued for their biocompatibility and adaptability in applications like drug delivery and medical imaging. However, predicting SiNP biodistribution and clearance remains a significant challenge. To address this, we developed a minimal physiologically-based pharmacokinetic (mPBPK) model to simulate the systemic disposition of SiNPs, calibrated using in vivo PK data from mice. The model assesses how variations in surface charge, size, porosity, and geometry influence SiNP biodistribution across key organs, including the kidneys, lungs, liver, and spleen. A global sensitivity analysis identified the most influential parameters, with the unbound fraction and elimination rate constants for the kidneys and MPS emerging as critical determinants of SiNP clearance. Non-compartmental analysis (NCA) further revealed that aminated SiNPs exhibit high accumulation in the liver, spleen, and kidneys, while mesoporous SiNPs primarily accumulate in the lungs. Rod-shaped SiNPs showed faster clearance compared to spherical NPs. The mPBPK model was extrapolated to predict SiNP behavior in humans, yielding strong predictive accuracy with Pearson correlation coefficients of 0.98 for mice and 0.92 for humans. This model provides a robust framework for predicting the pharmacokinetics of diverse SiNPs, offering valuable insights for optimizing NP-based drug delivery systems and guiding the translation of these therapies from preclinical models to human applications.

The role of tissue oxygenation in obesity-related cardiometabolic complications

AbstractObesity is a complex, multifactorial, chronic disease that acts as a gateway to a range of other diseases. Evidence from recent studies suggests that changes in oxygen availability in the microenvironment of metabolic organs may exert an important role in the development of obesity-related cardiometabolic complications. In this review, we will first discuss results from observational and controlled laboratory studies that examined the relationship between reduced oxygen availability and obesity-related metabolic derangements. Next, the effects of alterations in oxygen partial pressure (pO2) in the adipose tissue, skeletal muscle and the liver microenvironment on physiological processes in these key metabolic organs will be addressed, and how this might relate to cardiometabolic complications. Since many obesity-related chronic diseases, including type 2 diabetes mellitus, cardiovascular diseases, chronic kidney disease, chronic obstructive pulmonary disease and obstructive sleep apnea, are characterized by changes in pO2 in the tissue microenvironment, a better understanding of the metabolic impact of altered tissue oxygenation can provide valuable insights into the complex interplay between environmental and biological factors involved in the pathophysiology of metabolic impairments. This may ultimately contribute to the development of novel strategies to prevent and treat obesity-related cardiometabolic diseases.

The role of microRNAs in pregnancies complicated by maternal diabetes.

With the global prevalence of diabetes increasing, more people of reproductive age are experiencing hyperglycaemic pregnancies. Maternal Type 1 (T1DM) or Type 2 (T2DM) diabetes mellitus, and gestational diabetes mellitus (GDM) are associated with maternal cardiovascular and metabolic complications. Pregnancies complicated by maternal diabetes also increase the risk of short- and long-term health complications for the offspring, including altered fetal growth and the onset of T2DM and cardiometabolic diseases throughout life. Despite advanced methods for improving maternal glucose control, the prevalence of adverse maternal and offspring outcomes associated with maternal diabetes remains high. The placenta is a key organ at the maternal-fetal interface that regulates fetal growth and development. In pregnancies complicated by maternal diabetes, altered placental development and function has been linked to adverse outcomes in both mother and fetus. Emerging evidence suggests that microRNAs (miRNAs) are key molecules involved in mediating these changes. In this review, we describe the role of miRNAs in normal pregnancy and discuss how miRNA dysregulation in the placenta and maternal circulation is associated with suboptimal placental development and pregnancy outcomes in individuals with maternal diabetes. We also discuss evidence demonstrating that miRNA dysregulation may affect the long-term health of mothers and their offspring. As such, miRNAs are potential candidates as biomarkers and therapeutic targets in diabetic pregnancies at risk of adverse outcomes.

Impact of nitric oxide donors on capsule, biofilm and resistance profiles of Klebsiella pneumoniae

Klebsiella pneumoniae is considered to be a critical public health threat due to its ability to cause fatal, multi-drug-resistant infections in the bloodstream and key organs. The polysaccharide-based capsule layer that shields K. pneumoniae from clearance via innate immunity is a prominent virulence factor. K. pneumoniae also forms biofilms on biotic and abiotic surfaces. These biofilms significantly reduce penetration by, and antibacterial activity from, traditional antibiotics. Nitric oxide (NO), an endogenous molecule involved in the innate immune system, is equally effective at eradicating bacteria but without engendering resistance. This study investigated the effects of NO-releasing small molecules capable of diverse release kinetics on the capsule and biofilm formation characteristics of multiple K. pneumoniae strains. The use of NO donors with moderate and extended NO-release properties (i.e., half-life >1.8 h) inhibited bacterial growth. Additionally, treatment with NO decreased capsule mucoviscosity in K. pneumoniae strains that normally exhibit hypermucoviscosity. The NO donors were also effective against K. pneumoniae biofilms at the same minimum biocidal concentrations that eliminated planktonic bacteria, while meropenem showed little antibacterial action in the same experiments. These results represent the first account of exogenous NO affecting biomarkers involved in K. pneumoniae infections, and may therefore inform future development of NO-based therapeutics for treating such infections.

Comparative Transcriptome Analysis of Mature Leaves of Dimocarpus longan cv. ‘Sijimi’ Provides Insight into Its Continuous-Flowering Trait

Longan (Dimocarpus longan Lour.) is an important tropical and subtropical fruit, and most of its cultivars bloom once a year (once-flowering, OF). Dimocarpus longan cv. ‘Sijimi’ (SJ) is a tropical ecotype variety that blooms several times a year (continuous-flowering, CF) without the need for low-temperature induction. Several studies have focused on the mechanism of continuous flowering in SJ longan; however, none used leaves as research material. As leaves are a key organ in sensing floral-induction signals, we compared gene-expression differences between mature leaves of CF (SJ) and OF (D. longan cv. ‘Shixia’ (SX) and D. longan cv. ‘Chuliang’ (CL)) longan by transcriptome sequencing. An average of 47,982,637, 43,833,340 and 54,441,291 clean reads were obtained for SJ, SX and CL respectively, and a total of 6745 differentially expressed genes (DEGs) were detected. Following Metabolic pathways, Plant-pathogen interaction and Biosynthesis of secondary metabolites, most of the other genes were assigned to the KEGG classifications of MAPK signaling pathway- plant, Plant hormone signal transduction, Amino sugar and nucleotide sugar metabolism and Starch and sucrose metabolism. WGCNA analysis clustered genes into 27 modules, among which bisque4 and darkorange2 module genes specifically were expressed at low and high levels in SJ, respectively. Different gene-expression patterns were detected between CF and OF longan in bisque4 and darkorange2 modules, especially the high levels of transcription factor (TF) expression and the large number of gibberellic acid (GA)-signaling-pathway-specific genes expressed at high levels in CF longan (SJ). Floral-induction-gene expression levels in CF longan, such as levels of GA-signaling-related and FT genes, were always high. In CF longan, after vegetative-growth accumulation, flowers could be directly induced, thereby eliminating the need for low-temperature induction.

Exploring mercury detoxification in fish: The role of selenium from tuna byproduct diets for sustainable aquaculture

Exposure to mercury (Hg) through fish consumption poses significant environmental and public health risks, given its status as one of the top ten hazardous chemicals. Aquaculture is expanding, driving a surge in demand for sustainable aquafeeds. Tuna byproducts, which are rich in protein, offer potential for aquafeed production, yet their use is challenged by the high content of heavy metals, particularly Hg. However, these byproducts also contain elevated levels of selenium (Se), which may counteract Hg adverse effects. This study examines the fate of dietary Hg and Se in an aquaculture model fish. Biomolecular speciation analyses through hyphenated analytical approaches were conducted on the water-soluble protein fraction of key organs of juvenile rainbow trout (Oncorhynchus mykiss) exposed to various combinations of Hg and Se species, including diets containing tuna byproducts, over a six-month period. The findings shed light on the dynamics of Hg and Se compounds in fish revealing potential Hg detoxification mechanisms through complexation with Hg-biomolecules, such as cysteine, glutathione, and metallothionein. Furthermore, the trophic transfer of selenoneine is demonstrated, revealing novel opportunities for sustainable aquafeed production. Understanding the interactions between Hg and Se in aquaculture systems is crucial for optimizing feed formulations and mitigating environmental risks. This research contributes to the broader goal of advancing sustainable practices in aquaculture while addressing food security challenges.

Liver adrenoceptor alpha-1b plays a key role in energy and glucose homeostasis in female mice.

The liver plays a major role in glucose and lipid homeostasis and acts as a key organ in the pathophysiology of metabolic diseases. Intriguingly, increased sympathetic nervous system (SNS) activity to the liver has been associated with the development and progression of type 2 diabetes and obesity. However, the precise mechanisms by which the SNS regulates hepatic metabolism remain to be defined. While liver alpha1-adrenoceptors were suggested to play a role in glucose homeostasis, the specific subtypes involved are unknown mainly because of the limitations of pharmacological tools. Here we generated and validated a novel mouse model allowing tissue-specific deletion of alpha-1b adrenoceptor (Adra1b) in hepatocytes to investigate the role of liver ADRA1B in energy and glucose metabolism. We found that selective deletion of Adra1b in mouse liver has limited metabolic impact in lean mice. However, loss of Adra1bin hepatocytes exacerbated diet-induced obesity, insulin resistance and glucose intolerance in female, but not male mice. In obese females, this was accompanied by reduced hepatic gluconeogenic capacity and reprogramming of gonadal adipose tissue with hyperleptinemia. Our data highlight sex-dependent mechanisms by which the SNS regulates energy and glucose homeostasis through liver ADRA1B.

Prox1a promotes liver growth and differentiation by repressing cdx1b expression and intestinal fate transition in zebrafish

The liver is a key endoderm-derived multifunctional organ within the digestive system. Prospero homeobox 1 (Prox1) is an essential transcription factor for liver development, but its specific function is not well understood. Here, we show that hepatic development, including the formation of intrahepatic biliary and vascular networks, is severely disrupted in prox1a mutant zebrafish. We find that Prox1a is essential for liver growth and proper differentiation but not required for early hepatic cell fate specification. Intriguingly, prox1a depletion leads to ectopic initiation of a Cdx1b-mediated intestinal program and the formation of intestinal lumen-like structures within the liver. Morpholino knockdown of cdx1b alleviates liver defects in the prox1a mutant zebrafish. Finally, chromatin immunoprecipitation analysis reveals that Prox1a binds directly to the promoter region of cdx1b, thereby repressing its expression. Overall, our findings indicate that Prox1a is required to promote and protect hepatic development by repression of Cdx1b-mediated intestinal cell fate in zebrafish.

Tradisi Pawai Obor dalam Memperingati Tahun Baru Islam di Desa Bukit Peninjauan II Seluma

The torch parade, held annually to commemorate the Islamic New Year (1 Muharram) in Desa Bukit Peninjauan II, serves as a vital cultural and communal event that underscores both social cohesion and cultural preservation. This study investigates the significance and impact of the torch parade on the local community, focusing on how it functions as a vehicle for cultural continuity and social unity. The objectives of the study are to analyze the ways in which the parade fosters community involvement, preserves local traditions, and strengthens social bonds. The methodology employed includes qualitative observations and interviews with key participants and organizers involved in the event. Data collection involved direct observations during the parade, interviews with community members, and analysis of participation records and event feedback. The findings reveal that the parade significantly contributes to the preservation of cultural heritage by engaging multiple generations in the celebration. It acts as a catalyst for social interaction, enhancing community solidarity and collective identity. Additionally, the event provides a platform for the younger generation to actively participate in cultural practices, thereby ensuring the transmission of cultural values. The study concludes that the torch parade not only serves as a festive occasion but also plays a crucial role in maintaining and reviving traditional practices within the community. By fostering a strong sense of communal identity and pride, the event supports the broader objectives of cultural preservation and social cohesion.

Research on Dual-Phase Composite Forming Process and Platform Construction of Radial Gradient Long Bone Scaffold.

The structure and composition of natural bone show gradient changes. Most bone scaffolds prepared by bone tissue engineering with single materials and structures present difficulties in meeting the needs of bone defect repair. Based on the structure and composition of natural long bones, this study proposed a new bone scaffold preparation technology, the dual-phase composite forming process. Based on the composite use of multiple biomaterials, a bionic natural long bone structure bone scaffold model with bone scaffold pore structure gradient and material concentration gradient changes along the radial direction was designed. Different from the traditional method of using multiple nozzles to achieve material concentration gradient in the scaffold, the dual-phase composite forming process in this study achieved continuous 3D printing preparation of bone scaffolds with gradual material concentration gradient by controlling the speed of extruding materials from two feed barrels into a closed mixing chamber with one nozzle. Through morphological characterization and mechanical property analysis, the results showed that BS-G (radial gradient long bone scaffolds prepared by the dual-phase composite forming process) had obvious pore structure gradient changes and material concentration gradient changes, while BS-T (radial gradient long bone scaffolds prepared by printing three concentrations of material in separate regions) had a discontinuous gradient with obvious boundaries between the parts. The compressive strength of BS-G was 1.00 ± 0.19 MPa, which was higher than the compressive strength of BS-T, and the compressive strength of BS-G also met the needs of bone defect repair. The results of in vitro cell culture tests showed that BS-G had no cytotoxicity. In a Sprague-Dawley rat experimental model, blood tests and key organ sections showed no significant difference between the experimental group and the control group. The prepared BS-G was verified to have good biocompatibility and lays a foundation for the subsequent study of the bone repair effect of radial gradient long bone scaffolds in large animals.

Imazalil and prochloraz toxicokinetics in fish probed by a physiologically based kinetic (PBK) model.

Azole fungicides are highly suspected endocrine disruptors (EDs) and are frequently detected in surface water. Among them, there are prochloraz (PCZ), a commonly used moleculefor ED studies, and imazalil (IMZ), a highly suspected ED. Little is known about their toxicokinetic (TK) behavior in fish. Hence, research suggested that an improved risk assessment could be achieved by gaining insight into their TK behavior. The aim of this study is to understand and model the TK of both substances in different fish species, irrespective of the scheme of exposure. TK data from the literature were retrieved including different modes of exposure (per os and waterborne). In addition, two experiments on zebrafish exposed to either IMZ or PCZ were performed to address the lack of in vivo TK data. A physiologically based kinetic (PBK) model applied to IMZ and PCZ was developed, capable of modeling different exposure scenarios. The parameters of the PBK model were simultaneously calibrated on datasets reporting internal concentration in several organs in three fish species (original and literature datasets) by Bayesian methods (Monte Carlo Markov Chain). Model predictions were then compared to other experimental data (i.e., excluded from the calibration step) to assess the predictive performance of the model. The results strongly suggest that PCZ and IMZ are actively transported across the gills, resulting in a small fraction being effectively absorbed by the fish. The model's results also confirm that both molecules are extensively metabolized by the liver into mainly glucuronate conjugates. Overall, the model performances were satisfying, predicting internal concentrations in several key organs. On average, 90% of experimental data were predicted within a two-fold range. The PBK model allows the understanding of IMZ and PCZ kinetics profiles by accurately predicting internal concentrations in three different fish species regardless of the exposure scenario. This enables a proper understanding of the mechanism of action of EDs at the molecular initiating event (MIE) by predicting bioaccumulation in target organs, thus linking this MIE to a possible adverse outcome.

Advancement and Potential Applications of Epididymal Organoids.

The epididymis, a key reproductive organ, is crucial for sperm concentration, maturation, and storage. Despite a comprehensive understanding of many of its functions, several aspects of the complex processes within the epididymis remain obscure. Dysfunction in this organ is intricately connected to the formation of the microenvironment, disruptions in sperm maturation, and the progression of male infertility. Thus, elucidating the functional mechanisms of the epididymal epithelium is imperative. Given the variety of cell types present within the epididymal epithelium, utilizing a three-dimensional (3D) in vitro model provides a holistic and practical framework for exploring the multifaceted roles of the epididymis. Organoid cell culture, involving the co-cultivation of pluripotent or adult stem cells with growth factors on artificial matrix scaffolds, effectively recreates the in vivo cell growth microenvironment, thereby offering a promising avenue for studying the epididymis. The field of epididymal organoids is relatively new, with few studies focusing on their formation and even fewer detailing the generation of organoids that exhibit epididymis-specific structures and functions. Ongoing challenges in both clinical applications and mechanistic studies underscore the importance of this research. This review summarizes the established methodologies for inducing the in vitro cultivation of epididymal cells, outlines the various approaches for the development of epididymal organoids, and explores their potential applications in the field of male reproductive biology.