Histological Analysis Research Articles

Abstract 4147632: Unusually Expeditious Expansion of an Atrial Myxoma

Description of the Case Report: A 44-year-old female with a past medical history of unspecified skin cancer presented with exertional dyspnea for 1 day before admission and syncope 7 months before admission. Physical exam was noted for soft low low-pitched diastolic murmur at the cardiac apex, not appreciated on prior exam. Echocardiography revealed a 3.3x4.7 cm pedunculated, homogenous mass in the left atrium obstructing the mitral valve. Serum BNP was measured as 326. An echocardiogram from less than 29 months prior was reviewed and showed no mass in the left atrium. The patient underwent successful surgical resection of the mass. The mass measured approximately 7x6x2 cm. Histologic analysis reported a proliferation of myxoid stroma with cytologically bland spindle cells positive for calretinin, compatible with cardiac myxoma. Following the surgery, the patient experienced resolution of symptoms. Discussion: Atrial myxomas are the most common primary cardiac tumors. They present as mitral valve obstruction, mitral valve regurgitation, arrhythmias, or systemic thromboembolism. They are exceedingly rare with an incidence of 0.5 to 1 case per million individuals annually and typically resected immediately. Therefore, instances with well-documented growth rates are uncommon. In this case, we present an unusually fast-growing myxoma in a woman with shortness of breath and syncope. The reported growth rate of atrial myxomas ranges from 1.3 to 6.9 mm a month. Our patient had a negative echocardiogram less than 2.5 years before her presentation, followed by the development of a 7 x 6 x 2 cm mass. Since the onset is unknown, the precise growth rate of our patient's tumor is unknown but was at least 24 mm/month. It is important to consider myxoma in the differential diagnosis of a woman with new onset murmur and syncopal episode. Furthermore, recognizing the potential for rapid expansion is crucial to assessing the risks versus benefits of myxoma section.

Abstract 4136700: Sodium-Potassium Pump: Newly O-GlcNAc Protein Offering Potential Benefits in Hemorrhagic Shock situation

Hemorrhagic shock(HS) results from significant blood loss, leading to insufficient oxygen delivery, which causes metabolic changes and multi-organ dysfunction.The HS-related acute kidney injury developed by the patient are mainly due to alteration in Na/K ATPase.In previous O-GlcNAcylomic studies, we identified the Na/K ATPase as potentially O-GlcNAcylated.O-GlcNAcylation, a post-translational modification, plays a role in various cellular processes, such as cell survival and stress response.O-GlcNAcylation may have beneficial effect in shock situations. The objective of this study is to ascertain whether Na/K ATPase is O-GlcNAcylated and to elucidate its potential role during HS. Hemorrhagic shock was induced by an exsanguination of rats.They were then randomly treated or not with an O-GlcNAcase inhibitor, the NButGT(10mg/kg), to increase O-GlcNAc level.Blood pressure and heart rate were monitored throughout the experiment.Blood samples were collected for complete blood analysis, including biochemistry and gas measurements. kidneys were immediately frozen for histological and biochemical studies.To study the O-GlcNAcylation of Na/K ATPase an immunoprecipitation and Wheat Germ Agglutinin(WGA) based lectin affinity gel electrophoresis were used. HEK cells were treated with or without NButGT(100µM,6 hours) and/or ouabain(Na/K ATPase inhibitor) and a colorimetric kit was assessed to study O-GlcNAcylation impact on Na/K ATPase activity. O-GlcNAc levels increased by 2 folds in heart and kidney due to the NButGT treatment(p<0.05).Mean arterial pressure(MAP,p<0.01) and bicarbonate(p<0.01) are restored in treated group as kalemia(Sham:4.2 ± 0.1;HS:4.7±0.1;NButGT:4.3 ±0.1;mmol/L;p<0.05) and natremia(Sham:141.5±0.4;HS:139.8±0.5;NButGT:141.9 ±0.4; mmol/L;p<0.01).The study of the O-GlcNAcylation of the Na/K ATPase validated its O-GlcNAcylation.Histological analysis of the kidney showed that HS decreased Na/K ATPase expression, but treatment restored it(Sham:15.1±1.1;HS:10.3±0.6;NButGT:13.78±1.1;%area;p<0.05). An acute increase in O-GlcNAc levels through NButGT enhances Na/K ATPase activity. Increased O-GlcNAcylation during hemorrhagic shock restored MAP and reduced indicators of metabolic acidosis.Treatment with NButGT restored natremia and kalemia.This effect is linked to an increase in the expression and activity of Na/K ATPase.Our study is the first to confirm that Na/K ATPase is regulated by O-GlcNAcylation, particularly in terms of its localization and stability.

Abstract 4138380: Cardiac protection of hiPSC-CMs loaded chitosan cardiac patch in myocardial infarcted swine

Background: The low grafting rate of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) following direct injection into the myocardium limits the efficacy of cardiac repair after myocardial infarction (MI). Chitosan-based scaffolds have emerged as functional biomaterials for designing delivery systems in cardiac therapies. This study aimed to enhance the potency of cardiac repair using a hiPSC-CMs loaded chitosan cardiac muscle patch (hCCMP). Methods: The patches were fabricated using chitosan. Characterization of the chitosan patches involved assessing their swelling rate and porosity. The biocompatibility of the hCCMP was analyzed through scanning electron microscopy (SEM) and the CCK8 assay. 16 Yorkshire swine (15-20 kg, 45-50 days of age) were randomly divided into 4 groups (n=4 per group): Sham, MI without further intervention, MI with an empty patch (without hiPSC-CMs), and MI with hCCMP implantation. One and four weeks post-MI, heart function, Infarction size, myocardial perfusion and metabolism were evaluated via cardiac PET-MRI. Engraftment was assessed through human cardiac troponin T staining. Histological analysis including left ventricular anterior wall thickness, cardiac remodeling, angiogenesis, arterialization, and apoptosis in the infarct border area were analyzed using immunofluorescence. Results: SEM showed that the chitosan patch had regular pore size and good 3D structure; porosity was about (96.7±0.37)%. On day3, the patch swelling rate was about (715±64.55)%. SEM, CCK8 assay showed a normal cells growth in the chitosan patch. The hiPSC-CMs grafted well with chitosan patch delivery systems and was associated with significantly improvement in LV function, infarction size, angiogenesis and cardiomyocyte apoptosis in pigs 4 weeks after MI. Conclusions: The 3D chitosan cardiac patch with hiPSC-CMs loaded can enhance the potency of cardiac repair in pigs after MI and present a novel and promising therapic strategy.

Tracking inflammation resolution signatures in lungs after SARS-CoV-2 omicron BA.1 infection of K18-hACE2 mice.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019 (COVID-19), which can result in severe disease, often characterised by a 'cytokine storm' and the associated acute respiratory distress syndrome. However, many infections with SARS-CoV-2 are mild or asymptomatic throughout the course of infection. Although blood biomarkers of severe disease are well studied, less well understood are the inflammatory signatures in lung tissues associated with mild disease or silent infections, wherein infection and inflammation are rapidly resolved leading to sequelae-free recovery. Herein we described RNA-Seq and histological analyses of lungs over time in an omicron BA.1/K18-hACE2 mouse infection model, which displays these latter features. Although robust infection was evident at 2 days post infection (dpi), viral RNA was largely cleared by 10 dpi. Acute inflammatory signatures showed a slightly different pattern of cytokine signatures compared with severe infection models, and where much diminished 30 dpi and absent by 66 dpi. Cellular deconvolution identified significantly increased abundance scores for a number of anti-inflammatory pro-resolution cell types at 5/10 dpi. These included type II innate lymphoid cells, T regulatory cells, and interstitial macrophages. Genes whose expression trended downwards over 2-66 dpi included biomarkers of severe disease and were associated with 'cytokine storm' pathways. Genes whose expression trended upward during this period were associated with recovery of ciliated cells, AT2 to AT1 transition, reticular fibroblasts and innate lymphoid cells, indicating a return to homeostasis. Very few differentially expressed host genes were identified at 66 dpi, suggesting near complete recovery. The parallels between mild or subclinical infections in humans and those observed in this BA.1/K18-hACE2 mouse model are discussed with reference to the concept of "protective inflammation".

TMOD-36. NANOGLIOS: A MINIATURIZED PATIENT AVATAR ENABLING RAPID AND HIGH-THROUGHPUT PHENOTYPIC SCREENING FOR GLIOMAS

Abstract BACKGROUND Establishing pre-clinical patient derived orthtopical xenograft models for IDH-mutant and H3K27M-mutant gliomas has presented significant histological challenges. There is increasing interest in developing faithful patient-derived ex vivo 3D models to replicate these type of gliomas, aiming to accelerate drug screening efforts. METHOD We developed a rapid approach for establishing nanoliter-sized miniature glioma organoids, termed NanoGlios, by leveraging emulsion microfluidics. We tested the robustness of NanoGlios for neurosphere culture, glioma xenografts, and primary patient samples, focusing on H3K27M-mutant diffuse midline gliomas (DMGs) and IDH-mutant gliomas. We compared the morphological features of NanoGlios to their counterparts using high-content imaging, H&E staining, and histological analysis. Additionally, we evaluated the mutation and gene expression profiles of NanoGlios relative to their counterparts. Furthermore, we conducted proof-of-concept drug screening of NanoGlios with various inhibitors and established an AI-enhanced high-throughput phenotypic imaging-based screening platform. RESULTS We successfully established NanoGlios from various sample sources, including neurospheres, xenografts, and primary tissues harboring H3K27M or IDH1/2 mutations. NanoGlios derived from xenografts or primary tissues captured more heterogeneous patterns as compared to the neuropsheres. We were able to generate thousands of NanoGlios and perform drug assays for hundreds of conditions at passage 0 within two weeks from both resected glioma tissues and xenografts. The AI phenotypic screening enabled us to identify differential responses of NanoGlios to ONC-201 treatment and drug responses to mutant IDH inhibitors Vorasidenib and Ivosidenib, which was not able to be detected by conventional cell viability bulk assays.

Reproductive biology of long-whiskered catfish (Mystus aor) relative to temperature and precipitation from the Kaptai Lake of Bangladesh.

Life-history information is necessary for effective conservation, aquaculture development and broodstock management of fishing populations, especially for fish with significant economic exploitation. Aiming to characterise the life-history traits in relation to the environmental parameters of the long-whiskered catfish, Mystus aor, a commercially important species from Kaptai Lake, Bangladesh, different life-history data were analysed. The monthly condition factor (K) ranged from 1.15 to 1.41, and the relative condition factor (Kn) ranged from 0.14 to 0.25. The estimated relative fecundity was 18474-55504 eggs/per fish, and the maximal oocyte diameter was found in May (0.83 ± 0.11μm). The lengths at first sexual maturity (Lm) for male and female M. aor were 49.5 cm and 54.1 cm, respectively. The GSI was peaked in May for both males and females, and histological analysis also revealed the presence of yolk granules and several mature spermatids in April and May in both sexes. Analysis of environmental data over 40 years in the Kaptai lake ecosystem indicate the significant increase in the precipitation rate in spawning month which is highly correlated with the spawning season. The findings of the current study will serve as a baseline for the conservation and broodstock management in the Kaptai Lake of Bangladesh.

Contribution of disease to Australian sea lion (Neophoca cinerea) pup mortality at Seal Bay, Kangaroo Island, 2016–2022

AbstractThe endangered Australian sea lion (Neophoca cinerea) population is declining, and its conservation is threatened by the species' low fecundity and high pup mortality. This study details reasons for pup deaths and quantifies the impacts of disease and comorbidity. Of 284 dead pups reported from five breeding seasons (2016–2022) at the Seal Bay colony, Kangaroo Island, gross necropsy was conducted on 122, with fecal analysis for hookworm (Uncinaria sanguinis) detection, tissue histology, and bacterial culture performed on subsets. Determinable primary causes of mortality were conspecific trauma (± comorbidity, 41.0%), starvation (24.6%), and infectious disease (hookworm‐associated hemorrhagic enteritis [HAHE] ± bacterial infection, 19.7%). Allowing for comorbidity, 37.7% of pups died with an infectious disease, including 44.0% of deaths with trauma and 41.5% with starvation. In higher mortality summer‐autumn breeding seasons, pups were at greater risk of trauma (p = .001) and subsequent bacterial infection (p < .001). Parasiticide treatment significantly reduced HAHE‐associated (p = .005) and overall mortality (p < .001) risk, suggesting hookworm infection increases pup susceptibility to other causes of mortality. Although the exact causal pathways for this treatment‐related overall mortality benefit remain to be confirmed, intervention appears highly impactful and could benefit species conservation efforts.

INNV-06. ADULT GLIOBLASTOMA WITH MISMATCH REPAIR DEFICIENCY FORMS A DISTINCT HIGH-RISK MOLECULAR SUBGROUP FOR WHICH TREATMENT WITH IPILIMUMAB-NIVOLUMAB SHOWS SURVIVAL ADVANTAGE

Abstract Glioblastoma is the most frequent and malignant primary brain tumor. Although the survival is generally dismal for glioblastoma patients, risk stratification and the identification of high-risk subgroups is important for prompt and aggressive management. The G1-G7 molecular subgroup classification based on the MAPK pathway activation has offered for the first time a non-redundant, all-inclusive classification of adult glioblastoma. Five patients from the large, 220-patient prospective cohort showed germline mutations in mismatch repair (MMR) genes and significantly worse median survival (3.25 months post-surgery) than those from other subgroups or from the rest of the cohort adjusted for age. These tumors were assigned to a new subgroup, G3/MMR, a spin-off from the major G3/NF1 subgroup, as they generally show genomic alterations leading to RAS activation. An integrated clinical, histological, immunohistochemical and molecular analysis of the G3/MMR tumors showed distinct characteristics as compared to other glioblastomas, including those with iatrogenic high tumor mutation burden (TMB), warranting a separate subgroup. Among these, prior history of cancer, midline location or multifocality, presence of multinucleated giant cells, positive p53 and MMR immunohistochemistry, and specific molecular characteristics, including high TMB, alert to this high-risk G3/MMR subgroup. High TMB constitutes the criterium for treatment with immune checkpoint inhibitors in solid cancers. The FDA-approved first-line therapy for advanced non-small cell lung cancer and high-TMB colorectal cancer is with the dual ipilimumab-nivolumab regimen. One of the five G3/MMR subgroup patients received the dual ipilimumab-nivolumab regimen and survived much longer than the rest of the G3/MMR patients, setting a proof-of-principle example for the treatment of these very aggressive G3/MMR glioblastomas.

TMIC-78. CHEMOTHERAPY INDUCED IMMUNOGENIC RESPONSE IN GLIOMA AND IMPLICATIONS FOR THERAPEUTIC STRATEGIES

Abstract INTRODUCTION Many glioblastoma (GBM) treatments fail because they treat tumor cells in isolation and ignore the surrounding microenvironment. In our phase 1b clinical trial of delivery of Topotecan (TPT) via Convection Enhanced Delivery (CED) in glioma, we demonstrated effective tumor cell elimination accompanied by a robust inflammatory response. We hypothesized that TPT induces an immunogenic response resulting in an unfavorable inflammatory landscape. METHODS To characterize chemotherapy’s effect on myeloid cells, we analyzed pre- and post-treatment biopsies from our trial using bulk RNA sequencing to measure canonical myeloid markers. We validated survival benefit of CED in vivo in our tumor model and characterized post-treatment tissue using single cell RNA sequencing (scRNA seq) after 7 days of treatment. We treated slice cultures generated from surgical samples of GBM with TPT and performed scRNA seq and histologic analysis to assess microenvironment changes after 24 hours of treatment. We used several in vitro assays to characterize the direct and indirect mechanisms of myeloid activation. RESULTS Bulk RNA sequencing of post treatment biopsies demonstrates upregulation of markers associated with activated and exhausted immune cell populations such as IBA1, CD68, MSR1, MARCO and loss of markers associated with homeostatic microglia such as P2RY12 and TMEM119. Similar results are found within 7 days of treatment in vivo, however, are not found in human derived samples treated acutely. Treatment of in vitro mono and co-culture systems demonstrate a tumor cell death dependent activation of myeloid cell populations via immunogenic molecules. CONCLUSIONS Chemotherapies eliminate proliferating glioma cells but also induce inflammation. While many investigators have tried to leverage this activation, our results suggest that chronic inflammation contributes to poor prognosis and recurrence. The identification of molecules responsible for this activation point to new therapeutic targets aimed at controlling treatment-induced inflammation, as part of a combinatorial approach to treat GBM.

Thrombo-CARE-cardioembolic stroke etiology in cryptogenic stroke suggested by fibrin-/platelet-rich clot histology : Thrombo-CARE (configuration analysis to refine etiology).

Despite extensive diagnostic efforts, the etiology of stroke remains unclear in up to 30% of patients. Mechanical thrombectomy (MT) potentially enhances etiological determination by (immuno)histological analysis of retrieved thrombotic material. In this monocentric exploratory study, clots from 200 patients undergoing MT were investigated by hematoxylin and eosin, CD3, and CD45 staining. Semiquantitative and computer-based image analysis defined the histological composition and relative fractions of immunohistochemically stained areas. First, we correlated these results with strokes of known etiology. Subsequently, clots of unknown source were characterized with regard to their (immuno)histological profile to attempt etiological classification. Samples from 198 patients were accessible for analysis. Fibrin-/platelet-rich histology appeared in 45(23%), erythrocyte-rich in 18(9%), and mixed histology in 123 (62%) patients. Etiology was classified as cardioembolic in 87(44%), arterioembolic in 37(19%), and as cryptogenic stroke (CS) in 26(13%) cases. 20(23%) patients with cardioembolic stroke and 5(14%) patients with arterioembolic stroke had fibrin-/platelet-rich clots. 8(22%) patients with arterioembolic stroke and 1(1%) patient with cardioembolic stroke had erythrocyte-rich clots. In CS, cardioembolic clot features appeared more than twice as often as arterioembolic clot features. Whereas the association between histology and etiology was significant (p = 0.0057), CD3/CD45 staining did not correlate. Asignificant association between histology and etiology was observed, with the proportion of erythrocyte-rich thrombi being largest among arterioembolic strokes and the proportion of fibrin-/platelet-rich thrombi highest among cardioembolic strokes. Ahigh number of clots from CS presented histological features of cardioembolic clots. Thus, patients with CS and fibrin-/platelet-rich clots particularly require long-term cardiac rhythm monitoring and may benefit from oral anticoagulation.

CNSC-23. CROSSTALK BETWEEN STROKE AND GLIOMA: ISCHEMIA-INDUCED NEURONAL ACTIVATION ON GLIOMA INFILTRATION

Abstract Glioblastoma (GBM) is an aggressive primary brain tumor associated with dismal survival rates. GBM is difficult to treat due to its ability to invade neighboring brain regions, rendering complete surgical resection nearly impossible. Throughout tumor progression, several pathological changes occur in the tumor microenvironment (TME) including increased neuronal hyperactivity. Interestingly, these pathological features also occur in stroke, a leading global cause of death and disease burden. Clinical evidence from large cohort studies reveals a 10% risk of brain tumor development in stroke patients, suggesting a link between these two diseases. However, the intricacies of their association and whether stroke poses a long-term risk for GBM is unclear. To investigate this, we have developed innovative stroke-glioma mouse models to recapitulate and delineate the interrelationship between these two diseases. Our data using these models indicate a substantial increase in tumor growth and infiltration towards the infarct using both human GBM-patient derived glioma cells in immunodeficient mice as well as in immunocompetent de novo mouse GBM. Further, spatial manipulation of stroke and glioma induction revealed that glioma cells preferentially invade the contralateral hemisphere towards the stroke lesion compared to control. This suggests stroke-induced changes may trigger glioma cell infiltration. Histological analysis of the TME shows increased neuronal activity specifically excitatory neuron synaptic marker expression in the leading edge of glioma post-stroke compared to control. Overall, stroke induction may promote tumor growth and infiltration by modulating the TME through increasing excitatory neuronal activation. Together, this study aims to deepen our understanding of the influence of stroke on gliomas, paving the way for invaluable insights essential for identifying at-risk patients and the development of potential treatments for affected patients.

Exploring Mesenchymal Stem Cells versus Minoxidil for Androgenic Alopecia Treatment: A detailed Animal-Based Histological and Morphometric Study.

Androgenic alopecia (AGA), a hair loss condition caused by Dihydrotestosterone (DHT) binding to hair follicle receptors, negatively impacts quality of life for both men and women. Current treatments like minoxidil and finasteride have limitations, highlighting the need for alternative therapies, such as human umbilical cord blood-derived mesenchymal stem cells (HUCB-MSCs). In this study, forty-eight adult male Wistar albino rats (3 months old) were used. The control group (Group I) received no treatment, while the other rats underwent AGA induction via daily subcutaneous testosterone injections (100 mg/kg). These rats developed alopecia and were divided into three groups: AGA (Group II), AGA plus daily minoxidil spray (Group III), and AGA plus a single intradermal injection of HUCB-MSCs (1 ml containing 1x10^5 cells, Group IV). After 4 weeks, the rats were sacrificed, and skin specimens were prepared for histological analysis using H&E, Masson's Trichrome, and immunohistochemical staining for CK 19, VEGF, and TUNEL antibodies. It was shown that HUCB-MSCs treatment reversed structural damage to hair and follicles, normalizing conditions within one week post-injection. The treatment enhanced the anagen phase, suppressed telogen and catagen phases, reduced apoptosis, and increased VEGF and CK 19 immune reactions. Observational follow-up for Groups III and IV revealed that while the minoxidil group experienced significant hair loss after 37 days, the stem cell group exhibited dense and long hair covering the treated area. HUCB-MSC therapy demonstrated superior efficacy over minoxidil with no observed side effects, indicating its potential as a promising alternative for AGA treatment.

A new domestic self-expanding nitinol stent: in vivo preclinical study

Objective. To evaluate the results of implantation of a new domestic self-expanding nitinol stent in experimental animals. Materials and methods. Experimental implantations of a self-expanding nitinol stent were performed in the common iliac artery of three Vietnamese Pot-bellied pigs. In the postoperative period, all animals received dual antiplatelet therapy for 3 months. Vital signs were also assessed throughout the observation period. After 3 months, the animals underwent control angiography and ultrasound examination of the iliofemoral segment, followed by withdrawal from the experiment by euthanasia. The next step was a macroscopic and histological analysis of the stented areas of the vessels. Results. The observation period of the animals was 3 months. Throughout the entire observation period, vital signs in all animals remained within normal values. The results of control angiography and ultrasound examination after 3 months demonstrated patency, as well as the absence of significant in-stent stenoses in two pigs. One animal showed signs of in-stent restenosis. The results of macroscopic and histological analysis showed signs of damage to the subendothelial layer, as well as myointimal hyperplasia. These changes were especially pronounced in the animal with restenosis. Our analysis showed that the presented results were due to excessive oversizing of the implanted stents (20–30 %). Conclusion. Our proposed self-expanding nitinol stent, in general, showed satisfactory results in the in vivo experiment. Nevertheless, it should be borne in mind that severe stent oversizing can cause excessive neointimal proliferation, which, in turn, will lead to the development of restenosis in the long-term postoperative period. In this regard, it is necessary to carry out an additional series of implantation of the presented stent to the experimental animals with less oversizing in order to determine its optimal values for this particular stent model.

Efficient Production of Chondrocyte Particles from Human iPSC-Derived Chondroprogenitors Using a Plate-Based Cell Self-Aggregation Technique

The limited capacity of articular cartilage for self-repair is a critical challenge in orthopedic medicine. Here, we aimed to develop a simplified method of generating chondrocyte particles from human-induced pluripotent stem cell-derived expandable limb-bud mesenchymal cells (ExpLBM) using a cell self-aggregation technique (CAT). ExpLBM cells were induced to form chondrocyte particles through a stepwise differentiation protocol performed on a CAT plate (prevelex-CAT®), which enables efficient and consistent production of an arbitrary number of uniformly sized particles. Histological and immunohistochemical analyses confirmed that the generated chondrocyte particles expressed key cartilage markers, such as type II collagen and aggrecan, but not hypertrophic markers, such as type X collagen. Additionally, when these particles were transplanted into osteochondral defects in rats with X-linked severe combined immunodeficiency, they demonstrated successful engraftment and extracellular matrix production, as evidenced by Safranin O and Toluidine Blue staining. These data suggest that the plate-based CAT system offers a robust and scalable approach to produce a large number of chondrocyte particles in a simplified and efficient manner, with potential application to cartilage regeneration. Future studies will focus on refining the system and exploring its clinical applications to the treatment of cartilage defects.

Alginate–Poly[2-(methacryloyloxy)ethyl]trimethylammonium Chloride (PMETAC) Immunoisolating Capsules Prolong the Viability of Pancreatic Islets In Vivo

Background/Objectives: This study focuses on the development and evaluation of novel alginate–poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (PMETAC) microcapsules for encapsulating pancreatic islets to address insulin deficiency in diabetes. Methods: In previous research, we fabricated and characterized PMETAC microcapsules, evaluating their stability and permeability in vitro. This study further probes the capsules in vivo, focusing on the functional activity of the encapsulated islets post-transplantation, their viability extension, and the assessment of the immunoprotective, antifibrotic properties, and biostability of the capsules. Results: Rabbit-derived islets were encapsulated and transplanted into diabetic rats. The encapsulated islets maintained insulin secretion for up to 90 days, significantly longer than non-encapsulated ones, which ceased functioning after 7 days. Histological analysis demonstrated high biocompatibility of the PMETAC coating, resulting in minimal fibrotic overgrowth around the capsules. Conclusions: The study highlights the critical role of immunoprotection and the tendency to reduce fibrosis in prolonging islet function. These findings suggest that PMETAC-coated capsules offer a promising solution for cell-based therapies in diabetes by improving graft longevity and reducing fibrotic overgrowth.

Biological testing of titanium-containing implants with noble metal coatings in an in vivo experiment

The aim of study is to conduct in vivo biological testing of titanium nickelide samples modifed with Ag/Pt or AuAg/Pt flm heterostructures in comparison with the bare carrier.Material and Methods. Titanium nickelide plates modifed with flm heterostructures made of noble metals and the laboratory mini-pigs used for in vivo tests were the objects of the study. To form flm structures on titanium nickelide samples, the physical gasphase deposition methods: ion plasma deposition (IPD) and thermal (PVD) sputtering were used. The Ag/ Pt or AuAg/Pt heterostructures were characterized by X-ray diffraction and scanning microscopy methods.Results. The biocompatibility of implants before (TiNi, control) and after (Ag/Pt/TiNi and AuAg/Pt/TiNi) modifcation with flm heterostructures was tested in in-vivo experiments on a laboratory animal (mini-pig). General toxic reactions of the body to the injected samples were absent. A comparative macroscopic and histological analysis of the condition of peri-implant tissues after 39 days of implantation was performed. The connective tissue capsule around the TiNi sample revealed the presence of a certain number of lymphocytes, eosinophils and macrophages, but these indicators decrease in the order of TiNi > AuAg/Pt/TiNi > Ag/Pt/TiNi.Conclusion. The positive effect of modifying the titanium nickelide surfaces with noble metal heterostructures on the biocompatibility of metal implants was demonstrated in an in vivo experiment.

Ginsenoside Rg1 Prevents and Treats Acute Pulmonary Injury Induced by High-Altitude Hypoxia

This study aimed to investigate the protective effects of ginsenoside Rg1 on high-altitude hypoxia-induced acute lung injury (ALI) and elucidated its molecular targets and related pathways, specifically its association with the fluid shear stress pathway. Using a combination of bioinformatics analysis and both in vivo and in vitro experiments, we assessed the role of ginsenoside Rg1 in mitigating physiological and biochemical disturbances induced by hypoxia. In the in vivo experiments, we measured arterial blood gas parameters, levels of inflammatory cells and cytokines, erythrocyte and platelet parameters, and conducted histological analysis in rats. The in vitro experiments utilized human pulmonary microvascular endothelial cells (HPMECs) and A549 cells to examine cell viability, intracellular reactive oxygen species (ROS) and Ca2⁺ levels, and mitochondrial function. The results of the in vivo experiments demonstrate that ginsenoside Rg1 significantly increased arterial blood oxygen partial pressure and saturation, elevated arterial blood glucose levels, and stabilized respiratory and metabolic functions in rats. It also reduced inflammatory cells and cytokines, such as tumor necrosis factor-α and interleukin-6, and improved erythrocyte and platelet abnormalities, supporting its protective role through the regulation of the fluid shear stress pathway. Histological and ultrastructural analyses revealed that Rg1 significantly protected lung tissue structure and organelles. In vitro experiments further confirmed that Rg1 improved cell viability in HPMEC and A549 cells under hypoxic conditions, decreased intracellular ROS and Ca2⁺ levels, and enhanced mitochondrial function. These findings collectively demonstrate that ginsenoside Rg1 exerts significant protective effects against high-altitude hypoxia-induced ALI by enhancing oxygen delivery and utilization, reducing inflammatory responses, and maintaining cellular metabolism and vascular function. Notably, the protective effects of Rg1 are closely associated with the regulation of the fluid shear stress pathway, suggesting its potential for treating high-altitude hypoxia-related diseases.

Histological and biochemical analysis of the possible protective effects of luteolin on testicular injury caused by Lead acetate in adult male albino rats.

Histological and biochemical analysis of the possible protective effects of luteolin on testicular injury caused by Lead acetate in adult male albino rats.

Meclozine and growth hormone ameliorate bone length and quality in experimental models of achondroplasia.

Achondroplasia (ACH) is a common skeletal dysplasia associated with short-limbed short stature caused by gain-of-function mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. Meclozine was found to inhibit FGFR3 signaling using a drug repositioning strategy. In some countries, growth hormone (GH) has been employed to ameliorate short stature in children with ACH. This study aims to investigate the effects of meclozine and GH on bone growth and quality using an experimental model of ACH. Meclozine (2mg/kg/day) and/or GH (0.35mg/kg/day) were administered to a mouse model of ACH from the age of 7 to 56days. Body length and body weight of each mouse were measured during these treatments. At the end of treatments, these mice were subjected to micro-computed tomography scans to measure the lengths of long bones and bone mineral density (BMD). The width of the growth plate was quantified by histological analysis. The body and bone length of transgenic mice significantly increased after treatment with meclozine and GH, although there was no additive effect of the combination therapy on promoting bone growth. In contrast, BMD was additively increased by the combination therapy. The width of the growth plate in transgenic mice was significantly increased by both treatments, although the hypertrophic zone was enlarged by meclozine but not by GH. Meclozine or GH may be an option for treating children with ACH to ameliorate bone length and quality, but the additive effect would be limited.

Adverse Effects of Aβ1-42 Oligomers: Impaired Contextual Memory and Altered Intrinsic Properties of CA1 Pyramidal Neurons

Aβ1-42 (amyloid beta) oligomers, the major neurotoxic culprits in Alzheimer’s disease, initiate early pathophysiological events, including neuronal hyperactivity, that underlie aberrant network activity and cognitive impairment. Although several synaptotoxic effects have been extensively studied, neuronal hyperexcitability, which may also contribute to cognitive deficits, is not fully understood. Here, we found several adverse effects of in vivo injection of Aβ1-42 oligomers on contextual memory and intrinsic properties of CA1 pyramidal neurons. Male rats underwent behavioral and electrophysiological studies 1 week after microinjections into the dorsal CA1 region, followed by histological analysis. After 1 week, Aβ1-42 oligomers impaired contextual learning without affecting basic physiological functions and triggered training-induced neuronal excitability. Furthermore, riluzole, a persistent sodium current (INaP) blocker, dose-dependently reduced Aβ1-42 oligomer-induced hyperexcitability. Congo red staining, which detects insoluble amyloid deposits, further identified labeling of CA1 pyramidal neurons while immunohistochemistry with lecanemab, which detects soluble Aβ oligomers, revealed immunoreactivity of both pyramidal and non-pyramidal cells in the target area. Therefore, our study suggests that a single injection of Aβ1-42 oligomers resulted in contextual memory deficits along with concomitant neuronal hyperexcitability and amyloid deposition in the CA1 region after 1 week.