Tissue Reactivity Research Articles

Biodistribution and toxic potential of silver nanoparticles when introduced to the female rat reproductive tract

The prevalence of ionic silver and silver nanomaterials in hygiene products has been increasing due to their antimicrobial activity. While numerous studies have examined the effects of nanosilver in laboratory settings, there is a limited understanding of its impact on reproductive tissues, as well as its biodistribution and toxicity upon intra-vaginal exposure. If ionic or nanosilver enters adjacent and internal tissues via intra-vaginal exposure, the overuse of hygiene products containing silver may potentially threaten woman's health. This study investigated the effects of intra-vaginal silver exposure in Female Fischer 344 rats to single and multiple doses of a commercial product containing silver, along with standard nanosilver materials. Custom tampons were developed to simulate practical usage scenarios. The analysis of tissue biodistribution revealed that epithelial penetration and redistribution of silver was observed with most administered silver eliminated in feces (8–44 %), and secondary tissues containing 1–18 % of the dose, predominantly localized in the reproductive tract. In a subsequent toxicity study, vaginal histopathology indicated a cellular inflammatory reaction (neutrophil infiltration) associated with the presence of foreign silver material upon a single administration. Interestingly, no noticeable difference in histopathology incidence was observed upon multiple exposures to silver compared to the control group. Clinical chemistry and hematology analyses following acute exposure to silver nanomaterials showed no significant abnormalities. Overall, acute vaginal exposure to silver nanomaterials and ionic silver resulted in limited silver persistence, local tissue reactivity, epithelial penetration of silver resulting in accumulation in distant organs, and elimination primarily through feces. In vitro data suggested potential alterations in normal vaginal flora. Long-term studies are still lacking in this area.

Biomechanical risk factors and subacromial pain provocation in healthy manufacturing workers

Objectives. Work-related musculoskeletal disorders (MSDs) of the shoulder may manifest subclinically. By combining risk assessment and clinical instruments, it may be advisable to recognize workers who may develop more complex MSDs early. This study aimed to evaluate the relationship between biomechanical risk factors and subacromial pain provocation in healthy manufacturing workers. Methods. A cross-sectional descriptive observational study was carried out with workers in the furniture manufacturing industry. The occupational repetitive action (OCRA) checklist was applied to detect risk factors and three clinical tests used to detect subacromial tissue reactivity: the supraspinatus test, the painful arc test and the Hawkins–Kennedy test. Results. The positivity of the clinical tests is higher in the supraspinatus test, followed by the Hawkins–Kennedy test, and lowest in the painful arc test, for both the right and left shoulders. No significant associations were found with the overall OCRA checklist index or specific biomechanical factors. Conclusion. The biomechanical risk factors and the provocation of subacromial pain reviewed in this study were not found to be related. Other physical tests that are more sensitive and adapted to workers at risk of developing musculoskeletal shoulder disorders should be explored.

Fast absorbing gut sutures in dermatologic surgery: a systematic review and meta-analysis.

Fast gut cutaneous sutures have become more prominent due to their low tissue reactivity, rapid absorption, and elimination of suture removal visits. It is not known how fast gut sutures compare to other closure modalities. A comprehensive literature review was conducted to identify randomized controlled trials comparing fast gut sutures to alternative closure methods during dermatologic surgery. Data collected included patient and physician assessed cosmetic outcome as well as standardized complication rates. Six studies were included in final analysis and reported on 208 patients. Fast gut sutures were associated with lower physician opinions of final scar when compared to polypropylene sutures (SMD 0.438; 95% CI 0.082 to 0.794). No differences existed between physician opinion of fast gut sutures and cyanoacrylate tissue adhesive (SMD -0.024; 95% CI -0.605 to 0.556). Complications with fast gut suture placement were rare, and included infection, dehiscence, and hematomas. Fast gut sutures were less likely to experience wound dehiscence than tissue adhesive (p = 0.01). If no contraindications to polypropylene sutures exist, they may provide superior cosmetic outcomes compared to fast gut sutures. Further research is required to better quantify cosmetic outcomes and optimal use of fast gut sutures.

A Comparative Analysis of Alkaline Phosphatase Levels in Gingival Crevicular Fluid of Patients Undergoing Growth Modulation Therapy With Twin Block, Forsus Fatigue Resistant, and Clear Block Appliances Compared to Normal Individuals: An In Vivo Study.

Background In the contemporary era, where science and technology know no boundaries, this in vivo study explores the impact of growth modulation therapy using Twin Block, Forsus Fatigue Resistant, and Clear Block appliances on alkaline phosphatase (ALP) levels in gingival crevicular fluid (GCF). Bone physiology involves modeling and remodeling, with orthodontics applying forces to teeth, influencing tissue reactivity and bone modeling. ALP, a marker of osteoblast function, plays a crucial role in bone growth. GCF reflects immunological and inflammatory responses during orthodontic force application, making it a valuable medium for studying ongoing metabolic processes related to bone turnover. Aim The study aims to comparatively analyze ALP levels in GCF during growth modulation therapy, assessing the efficacy of Twin Block, Forsus Fatigue Resistant, and Clear Block appliances. The research involves 30 experimental samples divided into three study groups and a control group. The samples are collected at various time intervals, and ALP levels are analyzed using a spectrophotometer. Statistical analysis includes paired and unpaired t-tests, one-way analysis of variance (ANOVA), and multiple comparisons. Results Results demonstrate a significant increase in ALP levels during the growth modulation therapy, indicating a positive correlation with bone remodeling. Twin Block appears to be the most effective appliance, exhibiting higher ALP activity compared to Clear Block and Forsus groups. Conclusion In conclusion, this study provides valuable insights into the biochemical responses during growth modulation therapy, emphasizing the potential of GCF analysis in understanding orthodontic treatment effects.

Immunotherapy Applications for Thymine Dimers and WT1 Antigen in Renal Cancers: A Comparative Statistical Analysis.

Renal cell carcinoma (RCC) remains incurable in advanced stages. Biomarkers have proven to be quite useful in cancer therapeutics. Herein, we provide a comparative/integrative statistical analysis of seminal immunohistochemistry (IHC) findings for Wilms' Tumor 1 antigen (WT1) and thymine dimers (TDs), emerging as atypical, yet promising, potential biomarkers for RCCs. We assessed WT1/TD reactivity in adult RCC tumor cells, tumor microenvironment (TME), and tumor-adjacent healthy renal tissue (HRT). WT1 positivity was scarce and strictly nuclear in tumor cells, whereas TD-reactive tumor tissues were prevalent. We report statistically significant positive correlations between the density of reactive RCC cellularity and the intensity of nuclear staining for both biomarkers (WT1 - rho = 0.341, p-value = 0.036; TDs - rho = 0.379, p-value = 0.002). RCC stromal TME TD-positivity was much more frequent than WT1 reactivity, apparently proportional to that of the proper RCC cellularity and facilitated by extensive RCC inflammatory infiltration. TDs exhibited nuclear reactivity for most TME cell lines, while RCC TME WT1 expression was rare and inconsistent. In HRTs, TDs were entirely restricted to renal tubular cells, the likely cellular progenitor of most conventional RCC subtypes. In lieu of proper validation, these early findings have significant implications regarding the origins/biology of RCCs and may inform RCC therapeutics, both accounting for the high frequency of immunotherapy-permissive frameshift indels in RCCs, but also hinting at novel predictive clinical tools for WT1-targeted immunotherapy. Overall, the current study represents a meek yet hopefully significant step towards understanding the molecular biology and potential therapeutic targets of RCCs.

Discovery of PSMA in the prostate of the common marmoset (Callithrix jacchus).

Prostate-specific membrane antigen (PSMA) is a biomarker and therapeutic target of high relevance in prostate cancer. Although upregulated PSMA expression is a well-documented feature of prostatic neoplasia in both humans and canids, to date humans are the only species known to express PSMA basally in the prostate. Thus, traditional laboratory animal species have limited utility for studying PSMA biology in the prostate or for predicting efficacy or toxicity of PSMA-targeted agents. PSMA expression in human, macaque, and marmoset prostates was determined by immunohistochemistry, employing an antibody with validated cross-species reactivity in a PSMA-positive control tissue; kidney. We newly discover that the common marmoset endogenously expresses PSMA in non-diseased prostate, similar to humans, and thus may be a valuable preclinical model for researchers studying PSMA.

Effect of the Flavonoid Rutin on the Modulation of the Myenteric Plexuses in an Experimental Model of Parkinson's Disease.

Recent discoveries have shown that enteric glial cells play an important role in different neurodegenerative disorders, such as Parkinson's disease (PD), which is characterized by motor dysfunctions caused by the progressive loss of dopaminergic neurons in the substance nigra pars compacta and non-motor symptoms including gastrointestinal dysfunction. In this study, we investigated the modulatory effects of the flavonoid rutin on the behavior and myenteric plexuses in a PD animal model and the response of enteric glia. Adult male Wistar rats were submitted to stereotaxic injection with 6-hydroxydopamine or saline, and they were untreated or treated with rutin (10 mg/kg) for 14 days. The ileum was collected to analyze tissue reactivity and immunohistochemistry for neurons (HuC/HuD) and enteric glial cells (S100β) in the myenteric plexuses. Behavioral tests demonstrated that treatment with rutin improved the motor capacity of parkinsonian animals and improved intestinal transit without interfering with the cell population; rutin treatment modulated the reactivity of the ileal musculature through muscarinic activation, reducing relaxation through the signaling pathway of nitric oxide donors, and increased the longitudinal contractility of the colon musculature in parkinsonian animals. Rutin revealed modulatory activities on the myenteric plexus, bringing relevant answers regarding the effect of the flavonoid in this system and the potential application of PD adjuvant treatment.

ВПЛИВ АЛКОГОЛЮ НА ЛІПІДНИЙ СКЛАД КРОВІ ТА ЛІПОПЕРОКСИДНІ ПРОЦЕСИ У ТКАНИНАХ МОЗКУ ЩУРІВ З РІЗНОЮ АЛКОГОЛЬНОЮ МОТИВАЦІЄЮ І РІЗНОЮ ЗДАТНІСТЮ ДО НАВЧАННЯ

B a c k g r o u n d . Alcohol, as a factor of negative influence on the organism, induces metabolic changes and may affect cognitive task performance, asnervous tissue is particularly sensitive to ethanol exposure. This sensitivity is manifested through oxidative processes in the brain and alterations in lipid metabolism. The study investigated the sensitivity of oxidative processes in brain tissue and changes in the blood lipid spectrum under the influence of ethanol with different combinations of alcoholization and trainingin rats. M e t h o d s . Male rats aged three to five months were used in the study. Learning ability was assessed in the radialmaze. The impact of ethanol on metabolic processes wase valuated by determining the lipid levels in blood plasma usingthin-layer chromatography. The effect of ethanol and training on brain tissues was examined by determining the amount of malondialdehyde in rat brain tissues spectrophotometrically using the 2-thiobarbituric acidtest. R e s u l t s . Unequali poperoxidative reactivity of rat brain tissues with different alcohol motivations was demonstrated under various combinations of ethanol and training. Rats showing no preference for alcohol exhibited higher lipoperoxidative reactivity, especially those that performed poorly in learning and consumed ethanol after training. Animals that learned well had a lowerlevel of peroxide oxidation after alcohol consumption. Rats preferring alcohol demonstrated the lowest degree of peroxideoxidation in brain tissues. C o n c l u s i o n s . Chronic alcoholism led to alterations in the lipid concentration in the rats' blood, indicating a moderate destabilizing effect of ethanol on lipid metabolism under the conditions of our experiment. High levels of lipid peroxidation in rat brain tissues are characteristic of rats with low alcohol motivation, while training rat spriorto the onset of alcoholismmayreduce the level of lipidperoxidation.

Novel technique for comminuted patellar fixation using suture tape in spiderweb configuration.

Patella fractures account for 1% of skeletal fractures in orthopedic surgery. Simple two-part patella fractures are uncommon; most fractures are comminuted with significant articular involvement. Traditionally, patella fractures have been fixed using a tension band technique with cerclage wire, which has several complications including soft-tissue irritation, implant migration, and breakage, leading to secondary implant removal in up to 37% of patients. Newer fixation methods using cannulated screws, hook plates, mesh plates, and locking plates show promise but are costly and require extensive soft-tissue dissection. There is a need for a better alternative, especially for the elderly with osteoporotic bones. Various authors have described patellar fixation techniques augmented with sutures and suture tape, showing satisfactory outcomes. This paper proposes a novel all-suture tape method for patellar fixation, suitable for common types of patella fractures including AO 34C1.1 (transverse), AO 34C2 (transverse and split), and 34C3 (comminuted). Suture tape is biomechanically superior in both soft tissue and bone. The patient is laid supine with the knee in full extension. A standard anterior midline approach is adopted. After reducing the fracture fragments and securing them with K-wires, non-absorbable suture tapes are used instead of cerclage wire. The tapes are passed multiple times through the soft tissue, creating loops that are then tensioned to compress the fracture fragments. The technique is completed by creating a tension band fixation with additional suture tapes. This technique offers several benefits, including reduced operative time, minimized soft-tissue dissection, and lower risk of implant prominence and irritation. The suture tape's superior tensile strength and low tissue reactivity reduce complications and the need for secondary surgeries. Early results from two cases show union achieved at 3 months without complications, with patients regaining full range of motion. This preliminary technical paper demonstrates the feasibility of using non-metallic implants for patella fracture fixation. The proposed method shows promising results, suggesting a potential shift in the approach to fracture fixation. Further research and larger cohort studies are needed to validate these findings.

Tissue changes and tissue reactivity following osteotomy by a conventional rotary device, an ultrasonic unit, and an Er: YAG laser – A comparative study in humans

IntroductionInnovative technologies from other fields of science are constantly being introduced in medicine. Research works on animals strongly confirm the belief in better results following ultrasound and laser surgery. The main conclusions are based on observations from different animal species, whose biological characteristics differ from those of humans. This requires scientific experiments to be performed and confirmed in humans. Material & methodsHuman mandible specimens harvested in vivo by a conventional low-speed rotary device, an ultrasonic unit, or an Er: YAG laser were studied and analyzed to compare their effects on bone morphology and tissue response following surgery. ResultsThe cutting surface of eighty biopsies was studied, as well the facial edema, pain levels, and jaw dysfunction were followed up in the same eighty patients from whom the slices were obtained. In the piezosurgery and drill groups, the borders exhibited irregular edges full of bone fragments and debris. Thermal alterations within the superficial surface in all bone samples were generally minimal. In all specimens, intact osteocytes were detectable away from the area of direct action of the bone-cutting device. It was established, that the reactive facial edema, pain levels, and jaw disfunction were with milder values following in vivo osteotomy by an ultrasonic unit and Er: YAG laser compared to the conventional drilling. Moreover, the recovery of the patients in these two groups was more pronounced. The observed tissue changes proved to affect the follow-up tissue reactions in the postoperative period (p ≤ 0.05). DiscussionBased on the established effects on human bone by its in vivo cutting, it can be concluded that laser and ultrasonic bone surgery was a superior alternative osteotomy method in humans to conventional drilling.

Biomechanical and tissue reaction: the effects of varying sutures size on canine abdominal wall stitching.

Larger diameter sutures can provide sufficient tensile strength to surgical incisions but may exacerbate the inflammatory response caused by the amount of implanted foreign material. This experiment aims to investigate the differences in biomechanical stability and tissue reactivity after suturing canine midline abdominal incisions with different suture sizes. Assessing the biomechanical differences between USP 2-0, 3-0, and 4-0 PGA sutures using uniaxial tensile testing on ex vivo canine midline skin and fascial muscle tissues using either a simple continuous or simple interrupted technique. mRNA and protein expression levels of inflammatory factors were measured through RT-PCR and ELISA. Tissue reactivity was evaluated using a semi-quantitative scoring system. For strains below 30% in skin and below 50% in muscle, there were no significant differences among groups. The results of skin biomechanical testing showed that the USP 4-0 PGA suture group demonstrated significantly lower maximum tensile strength compared to the USP 2-0 PGA or USP 3-0 PGA suture groups. However, it remained capable of providing at least 56.3 N (1.03 MPa) tensile strength for canine skin incisions, matching the tensile strength requirements of general canine abdominal wall surgical incisions. In addition, there were no statistically significant differences observed in the maximum tensile strength among different size of sutures according to the data of biomechanical testing in muscle. Larger diameter sutures led to increased levels of inflammatory factors (IL-1β, IL-6, TNF-ɑ) and tissue reactivity. Simple interrupted sutures caused higher levels of inflammatory factors in muscular tissue compared to simple continuous sutures. USP 4-0 PGA sutures provide sufficient biomechanical stability for suturing canine abdominal skin and linea alba. Suture size significantly influences tissue reactivity after suturing, with smaller gauge sutures reducing early tissue inflammatory response. Thus, USP 4-0 PGA suture has more advantages to suturing canine abdominal surgical incisions.

Stain normalization methods for histopathology image analysis: A comprehensive review and experimental comparison

The advent of whole slide imaging has brought advanced computer-aided diagnosis via medical imaging and artificial intelligence technologies in digital pathology. The examination of tissue samples through whole slide imaging is commonly used to diagnose cancerous diseases, but the analysis of histopathology images through a decision support system is not always accurate due to variations in color caused by different scanning equipment, staining methods, and tissue reactivity. These variabilities decrease the accuracy of computer-aided diagnosis and affect the diagnosis of pathologists. In this context, an effective stain normalization method has proved as a powerful tool to standardize different color appearances and minimize color variations in histopathology images. This study reviews different stain normalization methods highlighting the main methodologies, contributions, advantages, and limitations of correlated works. The state-of-the-art methods are grouped into four distinct categories. Next, we select ten representative methods from the groups and conduct an experimental comparison to investigate the strengths and weaknesses of different methods and rank them according to selected performance accuracy measures. The quality performances of selected methods are compared in terms of quaternion structure similarity index metric, structural similarity index metric, and Pearson correlation coefficient conducting experiments on three histopathological image datasets. Our findings conclude that the structure-preserving unified transformation-based methods consistently outperform the state-of-the-art methods by improving robustness against variability and reproducibility. The comparative analysis we conducted in this paper will serve as the basis for future research, which will help to refine existing techniques and develop new approaches to address the complexities of stain normalization in complex histopathology images.

A stochastic reaction–diffusion modeling investigation of FLASH ultra-high dose rate response in different tissues

Purpose: The aim of the study was to propose a theory based on topology and geometry of diffusion channels in tissue to contribute to the mechanistic understanding of normal tissue sparing at ultra-high dose rates (UHDRs) and explore an interplay between intra- and inter-track radical recombination through a reaction–diffusion mechanism.Methods: We calculate the time evolution of particle track structures using a system of coupled reaction–diffusion equations on a random network designed for molecular transport in porous and disordered media. The network is representative of the intra- and inter-cellular diffusion channels in tissues. Spatial cellular heterogeneities over the scale of track spacing are constructed by incorporating random fluctuations in the connectivity between network sites, resembling molecular mass and charge heterogeneities at the cellular level.Results: We demonstrate the occurrence of phase separation among the tracks as the complexity in intra- and inter-cellular structure increases. At the strong limit of structural disorder, tracks evolve individually like isolated islands with negligible inter-track as they propagate like localized waves in space, analogous to the Anderson localization in quantum mechanics. In contrast, at the limit of weak disorder in a homogeneous medium, such as water, the neighboring tracks melt into each other and form a percolated network of non-reactive species. Thus, the spatiotemporal correlation among chemically active domains vanishes as the inter-cellular complexity of the tissue increases from normal tissue structure to fractal-type malignancy.Conclusion: Differential FLASH normal tissue sparing may result from the interplay of the proximity of tracks over the intra- and inter-cellular landscape, a transition in the spatial distribution of chemical reactivity, and molecular crowding. In this context, insensitivities in the radiobiological responses of the tumors to FLASH-UHDR are interpreted via a lack of geometrical correlation among isolated tracks. The structural and geometrical complexities of cancerous cells prevent the clustering of tracks over a timescale, in which inter-track chemical reactivities presumably prevail in normal tissues. A series of systematic experiments on radiolysis-induced diffusivity and reactivity in actual normal and cancerous tissues must be performed to classify the tissues potentially spared by FLASH-UHDRs and verify our theory.

Effects of Δ9-Tetrahydrocannabinol and the Aminoalkylindole K2/Spice Constituent JWH-073 on Cardiac Tissue and Mesenteric Vascular Reactivity.

Background: Although use of Cannabis sativa is not associated with serious adverse effects, recreational use of aminoalkylindole (AAI) cannabinoid receptor agonists found in K2/Spice herbal blends has been reported to cause adverse cardiovascular events, including angina, arrhythmia, changes in blood pressure, ischemic stroke, and myocardial infarction. Δ9-Tetrahydrocannabinol (Δ9-THC) is the primary CB1 agonist found in cannabis and JWH-073 is one of the AAI CB1 agonists found in K2/Spice brands sold to the public. Methods: This study used in vitro, in vivo, and ex vivo approaches to investigate potential differences on cardiac tissue and vascular effects betweenJWH-073 and Δ9-THC. Male C57BL/6 mice were treated with JWH-073 or Δ9-THC and cardiac injury was assessed by histology. Effects of JWH-073 and Δ9-THC on H9C2 cell viability and ex vivo mesenteric vascular reactivity were also determined. Results: JWH-073 or Δ9-THC induced typical cannabinoid effects of antinociception and hypothermia but did not promote death of cardiac myocytes. No differences in cell viability were observed in cultured H9C2 cardiac myocytes after 24 h of treatment. In isolated mesenteric arteries from drug-naive animals, JWH-073 produced significantly greater maximal relaxation (96%±2% vs. 73%±5%, p<0.05) and significantly greater inhibition of phenylephrine-mediated maximal contraction (Control 174%±11%KMAX) compared with Δ9-THC (50%±17% vs. 119%±16%KMAX, p<0.05). Discussion: These findings suggest that neither cannabinoid at the concentrations/dose studied caused cardiac cell death, but JWH-073 has the potential for greater vascular adverse events than Δ9-THC through an increased vasodilatory effect.

Activation of inflammasomes and their effects on neuroinflammation at the microelectrode-tissue interface in intracortical implants

Invasive neuroprosthetics rely on microelectrodes (MEs) to record or stimulate the activity of large neuron assemblies. However, MEs are subjected to tissue reactivity in the central nervous system (CNS) due to the foreign body response (FBR) that contribute to chronic neuroinflammation and ultimately result in ME failure. An endogenous, acute set of mechanisms responsible for the recognition and targeting of foreign objects, called the innate immune response, immediately follows the ME implant-induced trauma. Inflammasomes are multiprotein structures that play a critical role in the initiation of an innate immune response following CNS injuries. The activation of inflammasomes facilitates a range of innate immune response cascades and results in neuroinflammation and programmed cell death. Despite our current understanding of inflammasomes, their roles in the context of neural device implantation remain unknown. In this study, we implanted a non-functional Utah electrode array (UEA) into the rat somatosensory cortex and studied the inflammasome signaling and the corresponding downstream effects on inflammatory cytokine expression and the inflammasome-mediated cell death mechanism of pyroptosis. Our results not only demonstrate the continuous activation of inflammasomes and their contribution to neuroinflammation at the electrode-tissue interface but also reveal the therapeutic potential of targeting inflammasomes to attenuate the FBR in invasive neuroprosthetics.

The Impact of DTYMK as a Prognostic Marker in Colorectal Cancer.

Overexpression of deoxythymidylate kinase (DTYMK) has been associated with more aggressiveness and pathological behaviors in hepatocellular carcinoma (HCC) and non-small cell lung cancer (NSCLC). However, the expression of DTYMK and its prognostic significance in colorectal cancer (CRC) patients are yet unknown. The goal of this study was to investigate the DTYMK immunohistochemistry reactivity in CRC tissues and to see how it correlated with various histological and clinical features as well as survival. Several bioinformatics databases and two tissue microarrays (TMAs) of 227 cases were used in this study. Immunohistochemistry assay was used to study the protein expression of DTYMK. Based on the GEPIA, UALCAN, and Oncomine databases, DTYMK expression has increased in tumor tissues at both RNA and protein levels in colorectal adenocarcinoma (COAD) compared to normal tissues. A high DTYMK H-score was found in 122/227 (53%) of the cases, whereas a low DTYMK H-score was found in 105/227. The age at diagnosis (P = 0.036), stage of the disease (P = 0.038), and site of origin (P = 0.032) were all linked to a high DTYMK H-score. Patients with high level of DTYMK had bad overall survival. Interestingly, high DTYMK protein level was associated with PSM2 (P = 0.002) and MSH2 (P = 0.003), but not with MLH2 or MSH6. This is the first study to cover the expression and prognostic significance of DTYMK in CRC. DTYMK was upregulated in CRC and could be considered as a prognostic biomarker.

Molecular Regulation of Concomitant Lower Urinary Tract Symptoms and Erectile Dysfunction in Pelvic Ischemia.

Aging correlates with greater incidence of lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) in the male population where the pathophysiological link remains elusive. The incidence of LUTS and ED correlates with the prevalence of vascular risk factors, implying potential role of arterial disorders in concomitant development of the two conditions. Human studies have revealed lower bladder and prostate blood flow in patients with LUTS suggesting that the severity of LUTS and ED correlates with the severity of vascular disorders. A close link between increased prostatic vascular resistance and greater incidence of LUTS and ED has been documented. Experimental models of atherosclerosis-induced chronic pelvic ischemia (CPI) showed increased contractile reactivity of prostatic and bladder tissues, impairment of penile erectile tissue relaxation, and simultaneous development of detrusor overactivity and ED. In the bladder, short-term ischemia caused overactive contractions while prolonged ischemia provoked degenerative responses and led to underactivity. CPI compromised structural integrity of the bladder, prostatic, and penile erectile tissues. Downstream molecular mechanisms appear to involve cellular stress and survival signaling, receptor modifications, upregulation of cytokines, and impairment of the nitric oxide pathway in cavernosal tissue. These observations may suggest pelvic ischemia as an important contributing factor in LUTS-associated ED. The aim of this narrative review is to discuss the current evidence on CPI as a possible etiologic mechanism underlying LUTS-associated ED.

Abstract 1354: Regulation and roles of polyamines in CD8+ T cell fate and function

Abstract CD8+ T cells play central roles in tumor immune surveillance and are major effectors in adoptive cell therapy (ACT). Thus, strategies that enhance their functions are an urgent clinical need. Metabolic reprogramming determines T cell fate and function, where glycolysis principally drives an effector phenotype while oxidative phosphorylation (OxPhos) drives T cell memory [1]. However, the roles of amino acid catabolism in controlling effector and memory CD8+ T cell fate and function are less well understood [1, 2]. Glutamine is essential for nucleotide biosynthesis and as an anaplerotic fuel source for the tricarboxylic acid (TCA) cycle. Isotope tracing experiments with 13C glutamine or 13C arginine revealed that glutamine is the major source of polyamines in activated CD8+ T cells. Further, activation of CD8+ T cells provokes marked increases in the expression and activity of enzymes that direct polyamine biosynthesis, specifically ornithine decarboxylase (Odc), spermidine synthase (Srm) and spermine synthase (Sms), as well as to increases in the polyamines putrescine, spermidine and spermine. Notably, pharmacologic inhibition of Odc using difluoromethylornithine (DFMO), or genetic deletion of Odc using CD8+ T cells from CD4-Cre;Odcfl/fl mice, augments cytokine production in activated CD8+ T cells, including IFN-γ, TNF-α and granzyme B. Further, metabolic flux analysis indicates that DFMO treatment switches the metabolism of activated CD8+ T cells to rely on OxPhos, a phenotype found in CD8+ tissue resident memory (TRM) cells that play key roles in tissue and anti-tumor immunity anti-tumor reactivity. Indeed, inhibition or loss of Odc augments other TRM phenotypes, including increases in CD69high;CD44high;S1PR1low;CD62Llow cells that define the TRM phenotype. In addition, ACT of DFMO treated CD8+ T cells augments their survival in vivo and augments the generation of CD69+CD103+CD69+CXCR6+ and Ly6C+ TRMs in the bone marrow. Finally, DFMO treatment enhances IFN-γ and TNF-α production in human TILs, and co-treatment with TGF-β polarizes TILs into CD69+CD103+ and CD69+CD49a+ TRM-like cells. We conclude that polyamines are a metabolic check point in CD8+ TRM generation and are an actionable target to improve the anti-tumor immunity of T-cell based immunotherapies. Citation Format: Aya G. Elmarsafawi, Rebecca S. Hesterberg, John L. Cleveland. Regulation and roles of polyamines in CD8+ T cell fate and function [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1354.

Mitigation of Monoamine Oxidase-Related Oxidative stress by Metformin and Empagliflozin in human atrial tissue

Both old and novel antidiabetic drugs have been reported to elicit cardioprotective, partially characterized pleiotropic effects. The present pilot study was aimed at assessing the effects of metformin (a biguanide) and empagliflozin (a SGLT2 inhibitor) on monoamine oxidase (MAO) A and B-related reactive oxygen species (ROS) production and vascular reactivity in atrial tissue isolated from patients subjected to elective cardiac surgery. Samples of atrial tissue were harvested during the surgical procedures, transferred to the laboratory and used for the: reactive oxygen species (ROS) measurements (immune-fluorescence, spectrophotometry–FOX assay) and assessment of MAO expression (qRT-PCR and immune-fluorescence) after incubation with metformin (10 μM, 12 h) and/or empagliflozin (10 μM, 12 h) in the presence vs absence of angiotensin 2 (Ang2, 100 nM), lipopolysaccharide (LPS, 1 μg/ml) and glucose (400 mg/dL). MAO-A and B are expressed in the atrial samples and acute incubation with Ang2, LPS and high glucose increased MAO expression and ROS production. All effects were alleviated in the presence of either antidiabetic drug. No cumulative effect was obtained when the drugs were added together. MAO-A and B are expressed in the human atrial tissue, up-regulated after ex-vivo stimulation with angiotensin 2, lipopolysaccharide and glucose and responsible for increased oxidative stress that was mitigated in the presence of either metformin or empagliflozin.

Tissue Reactivity to, and Stability of, Glaucoma Drainage Device Materials Placed Under Rabbit Conjunctiva.

PurposeTo evaluate tissue reactivity to, and the stability of, glaucoma drainage device materials placed under rabbit conjunctiva in vivo.MethodsDisks (diameter, 3 mm; thickness, ∼0.3 mm) fabricated from poly(styrene-block-isobutylene-block-styrene) (SIBS), silicone, stainless-steel, or glutaraldehyde cross-linked collagen (GACLC) were inserted under rabbit conjunctiva. Conjunctival and scleral sections obtained at 4, 8, and 12 weeks after surgery were immunostained for α-smooth muscle actin (SMA). The ratio of the maximum thickness of the α-SMA–positive conjunctiva to the scleral thickness (α-SMA/S ratio) was calculated. The in vivo stability of the drainage devices at 12 weeks after insertion was evaluated.ResultsThe mean α-SMA/S ratios of the SIBS and silicone groups were lower than that of the stainless-steel group at 4 weeks after surgery (P < 0.05), and that of the SIBS group was lower than that of the GACLC group (P < 0.05). The ratios at 8 weeks after surgery were lower in the SIBS and silicone groups than in the GACLC group (P < 0.01). The ratios at 12 weeks after surgery were lower in the SIBS and silicone groups than in the GACLC group (P < 0.05). The surface areas of GACLC disks explanted from conjunctivae were significantly lower than that of intact disks (P < 0.01).ConclusionsSIBS and silicon were highly biostable and exhibited less tissue reactivity than GACLC in vivo.Translational RelevanceComparisons of materials using animal models can predict the clinical stability and safety of such materials in humans.