Node Tissue Research Articles

Integrative multi-omics analysis reveals the role of tumor-associated endothelial cells and their signature in prognosis of intrahepatic cholangiocarcinoma

This study aims to investigate the interplay between tumor-associated endothelial cells (TECs) and immune cells within the tumor microenvironment (TME) and its impact on tumor prognosis. We conducted single-cell RNA sequencing (scRNA-seq) of tumor, normal, and lymph node tissues obtained from intrahepatic cholangiocarcinoma (ICC) patients to reveal the role of TECs in tumor angiogenesis and their significant heterogeneity. Meanwhile, we identified genes highly expressed in TECs and constructed TEC signatures (TEC.Sig). Next, we calculated TEC scores of samples based on TEC.Sig. Patients with higher TEC scores exhibited a higher frequency of KRAS mutations, which was associated with increased infiltration of neutrophils and immature dendritic cells (iDCs), and decreased numbers of natural killer (NK), CD4 + T, and CD8 + T effector memory (Tem) cells, indicating an inflammation-dominated immunosuppressive phenotype. In contrast, BAP1 mutations and CXCL12 overexpression showed a contrasting trend. Spatial transcriptomics analysis and histological experiments further confirmed that TECs interacted with various tumor-killing immune cells through the CXCL12/CXCR4 axis. Multiple tumor immunotherapy datasets confirmed that the TEC.Sig could predict patient responses to immunotherapy. The TEC score is a promising and reliable biomarker for predicting genetic mutations and prognosis in ICC patients. Enhancing the regulation of the CXCL12/CXCR4 signaling pathway may represent a potential novel therapeutic target for ICC treatment.

Inorganic nitrogen inhibits symbiotic nitrogen fixation through blocking NRAMP2-mediated iron delivery in soybean nodules

Symbiotic nitrogen fixation (SNF) in legume-rhizobia serves as a sustainable source of nitrogen (N) in agriculture. However, the addition of inorganic N fertilizers significantly inhibits SNF, and the underlying mechanisms remain not-well understood. Here, we report that inorganic N disrupts iron (Fe) homeostasis in soybean nodules, leading to a decrease in SNF efficiency. This disruption is attributed to the inhibition of the Fe transporter genes Natural Resistance-Associated Macrophage Protein 2a and 2b (GmNRAMP2a&2b) by inorganic N. GmNRAMP2a&2b are predominantly localized at the tonoplast of uninfected nodule tissues, affecting Fe transfer to infected cells and consequently, modulating SNF efficiency. In addition, we identified a pair of N-signal regulators, nitrogen-regulated GARP-type transcription factors 1a and 1b (GmNIGT1a&1b), that negatively regulate the expression of GmNRAMP2a&2b, which establishes a link between N signaling and Fe homeostasis in nodules. Our findings reveal a plausible mechanism by which soybean adjusts SNF efficiency through Fe allocation in response to fluctuating inorganic N conditions, offering valuable insights for optimizing N and Fe management in legume-based agricultural systems.

Eosinophilic gastroenteritis, a rare case report and literature review

Abstract Introduction/Objective Eosinophilic gastroenteritis (EGE) is a rare inflammatory condition affecting the gastrointestinal tract, initially described by Kaijser et al. in 1937. It manifests as eosinophil-rich infiltration throughout the GI tract, often accompanied by peripheral eosinophilia. EGE is categorized under eosinophilic gastrointestinal disorders (EGIDs), alongside eosinophilic esophagitis (EOE) and eosinophilic colitis (EC). Symptoms vary based on the affected GI segment. This report aims to present a case of extensive EGE in a young male patient and review of similar cases to enhance clinical and histopathologic understanding. Methods/Case Report A 29-year-old male presented with abdominal pain, nausea, vomiting, and recent weight loss. He had a history of similar abdominal symptoms for a few years. Previous extensive investigations were inconclusive. Current imaging revealed soft tissue nodules, mild splenomegaly, and biliary dilation. Laboratory tests showed no significant abnormalities. Endoscopy revealed a gastric antral ulcer with marked eosinophilic infiltration on microscopy. Results (if a Case Study enter NA) NA Conclusion Eosinophilic gastroenteritis is an uncommon disease that presents with variable non-specific symptoms which require a high level of suspicion for diagnosis. EGE diagnosis requires excluding other causes of eosinophil accumulation. There is no clear distinction between the upper normal and abnormally increased eosinophils in GIT biopsies. Peripheral eosinophilia is common, along with other abnormal laboratory findings. Diagnosis relies on histopathology due to nonspecific symptoms. Clinicians and pathologists face challenges in diagnosing EGE, emphasizing the importance of considering it in the differential diagnoses. Efforts to establish diagnostic criteria for EGE are limited, despite its long-known existence. The condition’s vague symptoms necessitate a high level of clinical suspicion, with diagnosis primarily based on histopathologic features.

Inter-laboratory comparison of real-time quaking-induced conversion (RT-QuIC) for the detection of chronic wasting disease prions in white-tailed deer retropharyngeal lymph nodes.

The rapid geographic spread of chronic wasting disease (CWD) in white-tailed deer (WTD; Odocoileus virginianus) increases the need for the development and validation of new detection tests. Real-time quaking-induced conversion (RT-QuIC) has emerged as a sensitive tool for CWD prion detection, but federal approval in the United States has been challenged by practical constraints on validation and uncertainty surrounding RT-QuIC robustness between laboratories. To evaluate the effect of inter-laboratory variation on CWD prion detection using RT-QuIC, we conducted a multi-institution comparison on a shared anonymized sample set. We hypothesized that RT-QuIC can accurately and reliably detect the prions that cause CWD in postmortem samples from medial retropharyngeal lymph node (RPLN) tissue despite variation in laboratory protocols. Laboratories from 6 U.S. states (Michigan, Minnesota, Missouri, New York, Pennsylvania, Wisconsin) were enlisted to compare the use of RT-QuIC in determining CWD prion status (positive or negative) among 50 anonymized RPLNs of known prion status. Our sample set included animals of 3 codon 96 WTD genotypes known to affect CWD progression and detection (G96G, G96S, S96S). All 6 laboratories successfully identified the true disease status consistently for all 3 tested codon 96 genotypes. Our results indicate that RT-QuIC is a suitable test for the detection of CWD prions in RPLN tissues in several genotypes of WTD.

Efficacy of echolaser smart interface-guided laser ablation in volume reduction of symptomatic benign thyroid nodules.

The management of benign symptomatic thyroid nodules until recent years has been limited to surgery, radioactive iodine treatment, or surveillance which is associated with the burden of morbidity of complications or symptom non-relief as well as cost. Laser ablation has emerged as a minimally invasive alternative, this uses laser energy to thermally ablate nodule tissue, leading to volume reduction and symptom relief. Long-term treatment response data is growing but remains limited in the United States. Our study aims to quantify the effectiveness of laser ablation in reducing the volume of thyroid nodules over a 12 to 18-month period. Retrospective review of data was conducted for 63 adults with cytologically benign, solid symptomatic thyroid nodules ranging from 1.333 cm3 to 103.794 cm3 in volume. Ultrasound-guided laser thermal ablation was performed on all nodules using EchoLaser X4 Smart Interface device with 1064 nm diode laser to deliver total ablation energy (joules), calculated per device guidelines. Serial sonographic volume measurements were conducted 1 month, 3 -6 months, 6 - 12 months, and 12 to 18 months post-ablation intervals. Study cohort was comprised of 63 thyroid nodules. reduction in nodule volume increased progressively over time, with median reductions of 46.05% [STD 21.8] at 1 month, 60.33% [STD 20.1] at 3-6 months, 68.69% [STD 18.8] at 6-12 months, and 64.04% [STD 19.27] at 12-18 months. A total of 62, 56, 42, and 17 nodules had available data for analysis at these respective intervals. This study demonstrated a marked progressive reduction of thyroid nodule volume following ablation. The treatment appears to be consistently effective in reducing symptoms across a wide range of nodule sizes, although the degree of volume reduction varies. The results of our study underscore the potential of laser ablation as a viable treatment option for thyroid nodules, with a sustained reduction in nodule volume observed over an extended post-procedure period.

8133 Spatial Transcriptomic Profiling of Pituitary Corticotroph Carcinoma: Uncovering Architectural Complexity

Abstract Disclosure: D. Zhang: None. M. Bergsneider: None. M.B. Wang: None. W. Kim: None. H. Vinters: None. A.P. Heaney: None. Most pituitary corticotroph adenomas are benign but ∼15% are refractory to conventional surgical, medical and even radiotherapeutic management. This tumor subset invade sellar adjacent structures, and in rare cases metastasize locally within the central nervous system or to neck lymph nodes (LN) or more distant organs such as the liver. To better understand the potential interactions between tumor cells and neighboring tissues during these progressive stages, we used spatial transcriptomics (ST, Visium, 10x Genomics) to profile the genetic composition and native architecture of 4 surgically resected corticotroph tumor paraffin-embedded samples collected from the same patient over several years. Samples 1& 2 invaded the sino-nasal mucosa, sample 3 the parietal dura, sample 4 the clival bone, and sample 5 had metastasized locally to a neck LN. Quality of the 4 samples was confirmed by DV200 score (51 ± 7%). An average of 2,473 tissue spots per tissue sample were obtained after sequencing with a median of 4,893 genes detected per spot. We then used the Seurat analytic pipeline to reconstitute spatial transcriptional distribution that authentically mirrored histologically verifiable structures. These included the main tumor area itself, it’s invading tumor edge, adjacent normal epithelium, dura, and LN tissue. Further deconvolution analysis revealed a distinct cellular composition at the invading tumor edge which was tissue context specific. For instance, a proliferative cell population was noted between the central tumor area and it’s invasive margin, B cell and fibroblast cell enrichment was prominent at sino-nasal mucosal invasive margins, whereas endothelial and pericyte cells were prominent along the tumor/ normal pituitary border. . As expected, the central tumor area expressed genes associated with corticotroph hormone production including POMC, NNAT, GAL and GNAS, genes associated with mitochondrial energy metabolism such as ATP5F1E, NDUFA8 and COX7B as well as transcripts related to lipid kinase activity (GKG, CERKL, PIK3C2G, DGKK). Most intriguingly, tumor cells at the fore-front of the invading edge expressed high level of cyclin-dependent kinases, potentially reflecting higher proliferative rates of these invasive margin cells. Additional studies to validate and define the role of theses invasive margin transcripts are now warranted to translate our profiling findings into potential drug targets. In summary, this is the first use of spatial transcriptomics to delineate the evolving transcriptomic features in a series of surgically resected pituitary corticotroph tumors from the same patient that progressed over time to a locally metastatic corticotroph carcinoma. It provides unparalleled insights into the differential transcriptional topography of corticotroph tumor tissue and most importantly, its invading edge and may identify novel therapeutic targets. Presentation: 6/3/2024

6634 Dual-Mediated PTH And Osteolytic Hypercalcemia In Metastatic Endometrial Carcinoma

Abstract Disclosure: C.K. Persaud: None. D.J. Beckman: None. Background: Hypercalcemia of malignancy occurs in 20-30% of advanced stage cancer patients. Etiologies include parathyroid hormone-related peptides (PTHrP)-mediated, osteolytic metastases-mediated, overproduction of 1,25-dihydroxycholecalciferol, and rarely parathyroid hormone (PTH)-mediated. PTH-mediated hypercalcemia of malignancy is rare and occurs through ectopic PTH production or primary hyperparathyroidism. We report a rare case of both PTH-mediated and osteolytic-mediated hypercalcemia in the setting of malignancy. Clinical Case: A 57-year-old female with history of endometrial cancer and multiple solid organ metastasis, presented with two weeks of progressive poor oral intake, nausea, emesis, and right flank pain. On hospital admission, she had a serum calcium of >20.1 mg/dL (8.6-10.2), PTH of 203 pg/mL (15.0-65.0), and creatinine of 1.7 mg/dL (0.7-1.2, baseline 1.3). Non-contrasted CT chest/abdomen/pelvis noted increased size of known right adrenal metastasis, new left adrenal metastasis, periaortic lymphadenopathy, and scattered nodules in the subcutaneous tissues of the abdomen and chest, however bone metastasis were not noted. Patient’s hypercalcemia was treated with zoledronic acid, calcitonin, cinacalcet, and eventually denosumab due to difficulty controlling hypercalcemia. Additional labs obtained during evaluation included ionized calcium >2.5 nmol/L (1.12-1.32), PTHrP <2.0 pmol/L (<2.0), 1,25-dihydroxycholecalciferol <10 pg/mL (21-65). Patient’s right adrenal metastasis biopsy one month prior to admission was subsequently stained for PTH and was negative. Technetium-99m sestamibi scan was obtained for localization of parathyroid adenoma or carcinoma. The scan did not localize, however did show numerous new lytic lesions in the skull, spine, sternum, rib cage, and right humerus. Patient’s hospital course was complicated by progressively worsening renal function, anemia, and thrombocytopenia. Patient was discharged to a long-term acute rehab facility off hypercalcemia treatment with a corrected calcium of 10.0 mg/dL. Conclusion: PTH-mediated hypercalcemia is a rare cause of hypercalcemia of malignancy. PTH levels are typically low or low-normal in osteolytic mediated hypercalcemia. Generally, if PTH is elevated in hypercalcemia, an alternate etiology is not evaluated. This case highlights a rare dual-mediated hypercalcemia of malignancy. The patient’s PTH level elevation was discordant with her high degree of hypercalcemia and prolonged treatment course. She was subsequently found to have widespread bone metastases contributing to hypercalcemia. While multiple etiologies of hypercalcemia can be rare, it is important to evaluate for all contributing causes, especially with additional clinical conditions, such as malignancy. Presentation: 6/3/2024

8078 TERT Positive Thyroid Nodule in the Setting of Metastatic Melanoma

Abstract Disclosure: E. Langnas: None. S. Chao: None. K.M. Gomes: None. A. Bhan: None. Metastatic disease to the thyroid gland is uncommon with a reported incidence of up to 4% in post-surgical specimens. Lung cancer is the most common primary tumor site in autopsy series. Clinically, renal cell carcinoma is the most common primary tumor site. Metastatic melanoma to the thyroid gland is clinically rare, however, in autopsy series, it has been reported with incidence of up to 39%. A 61-year-old man presented to the endocrinology clinic for an incidentally detected thyroid nodule. He had recently presented with a chronic cough, prompting a chest x-ray that revealed pulmonary nodules. Subsequent computed tomography (CT) showed numerous bilateral lung nodules measuring up to 2.5 cm and an incidental thyroid nodule. Ultrasound of the thyroid identified a 2.7 cm mixed cystic-solid right thyroid nodule. No risk factors for thyroid cancer were identified. His TSH was 3.51uIU (0.45 - 5.33 uIU/mL). The thyroid nodule was biopsied, and pathology revealed atypical spindle cells with irregular nuclear membranes and scattered histiocytes. A further review with cytopathology suggested non-thyroidal origin of the cells. Molecular testing with AFIRMA reported a telomerase reverse transcriptase (TERT) promoter mutation at C228T. The sequencing was negative for TERT C250T, BRAF, RET, PETC1, PTC3 and MTC. Due to concerns about metastatic disease, a positron-emission tomography (PET)-CT was conducted, revealing hypermetabolic lesions in numerous bilateral lung nodules, right thyroid nodule, porta hepatis lymph node, and a soft tissue nodule within the greater curvature of the gastric body. Subsequent biopsies of the right lung and gastric body confirmed the diagnosis of metastatic melanoma. On further questioning, it was found that the patient had a history of a skin lesion on his back that was excised several years ago with pathology reporting tumoral melanosis. Malignant melanoma has a poor prognosis due to high recurrence and metastatic rates. In melanoma, TERT promoter mutations are the most common mutations in noncoding regulatory regions. TERT C228T mutations and C250T mutations are seen in malignant melanoma and studies have shown that TERT promoter mutations are associated with aggressive clinical behavior. These TERT promoter mutations can also be seen in various other cancers including primary thyroid cancers with a similar association with more aggressive thyroid tumor characteristics. Our case describes a patient with a thyroid nodule and molecular testing noting a TERT promoter mutation. Both primary thyroid cancer and metastatic disease to the thyroid should be considered in these cases. This case also highlights the importance of obtaining a thorough history of prior malignancy in patients with thyroid nodules to assess the risk of metastatic disease. Presentation: 6/1/2024

8135 A Rare Case of Late Recurrence of Graves’ Disease Decades After Radioactive Iodine Therapy: Is it Really a Definitive Treatment?

Abstract Disclosure: K.S. Hill: None. R. Osman: None. Graves’ disease (GD) is the most common cause of hyperthyroidism in the US and worldwide. Radioactive iodine (RAI) therapy has excellent success rates in treatment of GD. Studies have demonstrated that RAI successfully treats GD with a single session in the majority of cases. Recurrence after RAI, if it occurs, is most commonly seen in the first year after RAI. However, this is rare particularly in patients who have developed evidence of successful treatment in the form of post-ablative hypothyroidism. Only a few case reports have demonstrated recurrence of GD more than 10 years after treatment of GD with RAI and development of post-ablative hypothyroidism. We report a case of GD recurrence approximately 30 years after ablation. A 69 y/o woman presented for evaluation of hyperthyroidism and newly discovered thyroid nodule. Her history was significant for GD with orbitopathy diagnosed in the early 1990s and treated with RAI. Following the ablation, she developed hypothyroidism and was managed for over 20 years on levothyroxine therapy. In recent years she began to develop symptoms of palpitations and heat intolerance with biochemical evidence of thyrotoxicosis despite reductions in her levothyroxine dose. She also developed recurrence of her orbitopathy, confirmed by ophthalmology. During this time, a neck CT incidentally described an atrophic thyroid gland with a 9 mm soft tissue nodule in the left thyroid bed. Follow up ultrasound showed a 1.1 cm nodule with increased vascularity in the left thyroid bed with an otherwise atrophic gland and no lymphadenopathy. Her levothyroxine was stopped for one month in preparation for a thyroid uptake scan, during which TSH increased to 15 mcU/mL. Scan showed overall severely decreased radioactive iodine uptake of the gland consistent with prior ablation although there was a faint uptake most focally conspicuous on the left side inferiorly. Thyroid stimulating immunoglobulin (TSI) was elevated at 1.35 IU/L (Ref 0.00-0.55). After discussion with the patient, the decision was made for surgical treatment with thyroidectomy. Pathology was benign. She was continued on her prior dose of levothyroxine 75 mcg daily however now with clinical and biochemical evidence of hypothyroidism requiring continued increase in levothyroxine dose to normalize TSH levels. GD is the most common cause of hyperthyroidism and RAI therapy is the most common definitive treatment for GD in the US. Recurrence of GD after ablative hypothyroidism is rare, particularly in the case of late recurrence decades after ablation. Only a few cases are reported in the literature, ours with the longest interval-to-relapse. Recurrence of orbitopathy may be the first clue. Our case highlights the need to continue to monitor clinically for recurrence of Graves’ disease long after RAI use. Presentation: 6/3/2024

Integrative analysis of H&E and IHC identifies prognostic immune subtypes in HPV related oropharyngeal cancer

BackgroundDeep learning techniques excel at identifying tumor-infiltrating lymphocytes (TILs) and immune phenotypes in hematoxylin and eosin (H&E)-stained slides. However, their ability to elucidate detailed functional characteristics of diverse cellular phenotypes within tumor immune microenvironment (TME) is limited. We aimed to enhance our understanding of cellular composition and functional characteristics across TME regions and improve patient stratification by integrating H&E with adjacent immunohistochemistry (IHC) images.MethodsA retrospective study was conducted on patients with Human Papillomavirus-positive oropharyngeal squamous cell carcinoma (OPSCC). Using paired H&E and IHC slides for 11 proteins, a deep learning pipeline was used to quantify tumor, stroma, and TILs in the TME. Patients were classified into immune inflamed (IN), immune excluded (IE), or immune desert (ID) phenotypes. By registering the IHC and H&E slides, we integrated IHC data to capture protein expression in the corresponding tumor regions. We further stratified patients into specific immune subtypes, such as IN, with increased or reduced CD8+ cells, based on the abundance of these proteins. This characterization provided functional insight into the H&E-based subtypes.ResultsAnalysis of 88 primary tumors and 70 involved lymph node tissue images reveals an improved prognosis in patients classified as IN in primary tumors with high CD8 and low CD163 expression (p = 0.007). Multivariate Cox regression analysis confirms a significantly better prognosis for these subtypes.ConclusionsIntegrating H&E and IHC data enhances the functional characterization of immune phenotypes of the TME with biological interpretability, and improves patient stratification in HPV( + ) OPSCC.

Design of a Phantom Mimicking Rectal Lymph Nodes for Magnetomotive Ultrasound

ObjectiveDurable and stable phantoms for verifying and validating the new magnetomotive ultrasound technique are lacking. Here we propose a phantom design to address this need. MethodsA mixture of styrene-butylene/ethylene-styrene (SEBS) in mineral oil and glass beads as a scattering material acted as a bulk material, in which a polyvinyl alcohol (PVA) inclusion containing magnetic nanoparticles in water solution and graphite was embedded. The design mimics nanoparticle-laden lymph nodes embedded in mesorectal fat, as would be the clinical scenario for diagnostic support of staging rectal cancer using magnetomotive ultrasound. ResultsThe estimated reflection between the insert and bulk material was 10%, matching the clinical case of a lymph node within fat (9%). Speed of sound, attenuation, and Young's modulus of the bulk material were matched with those of body fat. The insert also matched the acoustic and elastic properties of lymph node tissue except for attenuation, which was lower than that given in the literature. Glass beads and graphite were used to control backscatter levels in the respective tissue mimics, providing a contrast of -3.8 dB that was consistent with clinical image appearance. The magnitude of magnetomotion remained stable in three separate samples over the course of 3 weeks. ConclusionWe have developed a phantom for magnetomotive ultrasound that combines the stability of an oil-based bulk material with the necessity of using a water-based material for the insert. The production procedure may be applied to other phantoms where one tissue type needs to be embedded within another.

12498 Outcomes In Thyroid Cancer Patients Having Undergone Us-guided (usg) Fine Needle Aspiration Sampling Of Cervical Lymph Nodes And Soft Tissue Nodules

12498 Outcomes In Thyroid Cancer Patients Having Undergone Us-guided (usg) Fine Needle Aspiration Sampling Of Cervical Lymph Nodes And Soft Tissue Nodules

CEACAM1 increased the lymphangiogenesis through miR-423-5p and NF- kB in Non-Small Cell Lung Cancer

BackgroundLung cancer causes significant mortality, with invasion and metastasis being the main features that cause most cancer deaths. Lymph node metastasis is the primary metastatic route in non-small cell carcinoma (NSCLC) and influences the staging and prognosis of NSCLC. Cumulative studies have reported that Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is involved in the progression of various cancers. However, few studies have discussed the function of CEACAM1 in lymphangiogenesis in NSCLC. Here, we examined how CEACAM1 influences lymphangiogenesis in NSCLC. MethodsA total of 30 primary squamous cell carcinoma (LUSC) patients diagnosed with LN metastasis were prospectively selected. LUSC tumor tissues, para-cancerous tissues, and positive lymph node tissues were harvested. The expression and subcellular location of CEACAM1, CD31, and LVYE1 in clinical samples were detected by immunohistochemistry. Next, the CEACAM1 and hsa-miR-423-5p expressions were detected by qPCR. The protein expression of lymphangiogenesis-associated proteins and critical cytokines of the NF–κB pathway in HDLECs was detected by Western blot. A tube formation assay was performed to detect the lymphangiogenesis in different groups. The interaction between CEACAM1 and hsa-miR-423-5p was verified using a dual luciferase assay. ResultsCEACAM1 was found to be a potential gene associated with lung cancer prognosis. It was positively correlated with angiogenesis and lymphangiogenesis. Then, we detected the function of CEACAM1 in lymphangiogenesis and found that CEACAM1 promoted lymphangiogenesis. hsa-miR-423-5p overexpression inhibited lymphangiogenesis via targeting CEACAM1. Finally, we observed that CEACAM1 can activate the NF–κB pathway and, therefore, promote lymphangiogenesis. ConclusionWe found that CEACAM1 enhanced lymphangiogenesis in NSCLC via NF-kB activation and was repressed by miR-423-5p. This suggests the value of CEACAM1 as a new therapeutic marker in NSCLC.

Modeling the atrioventricular conduction axis using human pluripotent stem cell-derived cardiac assembloids

The atrioventricular (AV) conduction axis provides electrical continuity between the atrial and ventricular chambers. The "nodal" cardiomyocytes populating this region (AV canal in the embryo, AV node from fetal stages onward) propagate impulses slowly, ensuring sequential contraction of the chambers. Dysfunction of AV nodal tissue causes severe disturbances in rhythm and contraction, and human models that capture its salient features are limited. Here, we report an approach for the reproducible generation of AV canal cardiomyocytes (AVCMs) with invivo-like gene expression and electrophysiological profiles. We created the so-called "assembloids" composed of atrial, AVCM, and ventricular spheroids, which effectively recapitulated unidirectional conduction and the "fast-slow-fast" activation pattern typical for the vertebrate heart. We utilized these systems to reveal intracellular calcium mishandling as the basis of LMNA-associated AV conduction block. In sum, our study introduces novel cell differentiation and tissue construction strategies to facilitate the study of complex disorders affecting heart rhythm.

ThP1.10 - Expression Pattern of Arginase In Tumour Tissue In Male Breast Cancer

Abstract Aim To study the expression pattern of arginase in tumor tissue of male breast cancer (MBC) by immunohistochemistry (IHC). Methods We retrospectively analysed the data of 21 MBC patients who were treated in our centre from January 2018 to March 2022. Immunohistochemical analysis of arginase expression was performed in tumor and lymph node tissue with primary arginase-1 antibody (1:300 dilution). Results The mean patient age was 57 years (33–81 years). 10 patients (48%) had metastatic disease at presentation, while early breast cancer (EBC) and locally advanced breast cancer (LABC) constituted 19% and 33%, respectively. Invasive ductal carcinoma was the predominant histology, with luminal being the major subtype. Modified radical mastectomy was done in 9 patients (43%), and palliative chemotherapy was given to all metastatic patients. IHC analysis revealed a lack of arginase expression in the tumor tissue even though it was expressed in the surrounding neutrophils. Conclusion Contrary to the majority of existing literature, ours was an IHC-based study, which provides a more accurate estimation of arginase expression at the cellular level. The lack of arginase expression obtained in our study may point towards the non-expression of the enzyme in MBC. This suggests that arginase is not a tissue biomarker in MBC. Taking other studies with protein expression into account, arginase should be treated, if necessary, only as a blood biomarker.

Reference gene evaluation for normalization of gene expression studies with lymph tissue and node‑derived stromal cells of patients with oral squamous cell carcinoma.

Profiling studies using reverse transcription quantitative PCR (RT-qPCR) require reliable normalization to reference genes to accurately interpret the results. A stable reference gene panel was established to profile metastatic and non-metastatic lymph nodes in patients with oral squamous cell carcinoma. The stability of 18S ribosomal RNA (18SrRNA), ribosomal Protein Lateral Stalk Subunit P0 (RPLP0), ribosomal Protein L27 (RPL27), TATA-box binding protein (TBP), hypoxanthine phosphoribosyl-transferase 1 (HPRT1), beta-actin (ACTB), glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) and vimentin (VIM) was evaluated, as reference genes for profiling patient-derived lymph node stromal cells (LNSCs; N=8; N0:6, N+:2) and lymph node tissues (Patients:14, Nodes=20; N0:7; N+:13). The genes were initially assessed based on their expression levels, specificity, and stability rankings to identify the best combination of reference genes. VIM was excluded from the final analysis because of its low expression (high quantification cycle >32) and multiple peaks in the melting curve. The stability analysis was performed using Reffinder, which utilizes four tools; geNorm, NormFinder, BestKeeper and Comparative ∆Ct methods, thereby enabling the computing of a comprehensive ranking. Evaluation of the gene profiles indicated that while RPLP0 and 18SrRNA were stable in both lymph node tissues and LNSCs, HPRT1, RPL27 were uniquely stable in these tissues whereas ACTB and TBP were most stable in LNSCs. The present study identified the most stable reference gene panel for the RT-qPCR profiling of lymph node tissues and patient-derived LNSCs. The observation that the gene panel differed between the two model systems further emphasized the need to evaluate the reference gene subset based on the disease and cellular context.

Safety and practicality of an excisional lymph node study driving HIV cure research in South Africa.

Studying diseased human tissues offers better insights into the intricate interactions between pathogens and the human host. In conditions such as HIV and cancers, where diseases primarily manifest in tissues, peripheral blood studies are limited in providing a thorough understanding of disease processes and localized immune responses. We describe a study designed to obtain excisional lymph nodes from volunteers for HIV reservoir studies. Since study commencement in 2015, 181 lymph node excisions have been performed, resulting in collection of 138 lymph node tissues. Lymph nodes were surgically excised from study volunteers using a minimally invasive procedure, performed in a minor theater under local anesthesia. The surgery takes less than 30 minutes to complete, minimizing risk and stress on the volunteer. The small incision made during the procedure typically heals within a week. The associated discomfort is generally manageable, and participants are often able to resume their regular activities within a day. Only 5.5% of the study participants experienced minor adverse events, such as swelling and prolonged wound healing, recovering within 2 weeks with no serious adverse events reported. Our study demonstrates that when done with outmost care, obtaining excised lymph nodes for research is relatively safe and practical.

A cross-sectional study to correlate nuclear fixative properties of formal saline and clarke’s fluid for histomorphology evaluation of human tissues

Abstract Background: Formal saline is an extensively used cheapest and easily available tissue fixative. However, formalin has been proven to have carcinogenic effects. Clarke’s fluid is an alternative to formal saline and is effective in maintaining the morphological and cellular architecture. Objectives: The objective of the study was to compare the nuclear fixative properties of Clarke’s fluid and formal saline. Materials and Methods: The fresh human tissues of thin skin, large-sized arteries, lymph nodes, spleen, and ileum were obtained from the fresh cadaver. The tissues were fixed in two different fixatives namely 10% formalin and Clarke’s fluid. Then, the tissues were histologically processed. The hematoxylin and eosin-stained serial sections of tissues were graded based on the ease of microtomy, cytoplasmic, and nuclear staining scores. Results: The nuclear properties of all the tissues immersed in Clarke’s fluid showed a median score of 3 and Grade 2 for formal saline; cytoplasmic properties for spleen and skin were median scores of Grade 3 for Clarke’s fluid. The artery was graded 3 for both the fixatives. The Kruskal–Wallis test when applied to nuclear properties, cytoplasmic adequacy, and tissue shrinkage for tissues stained with Clarke’s fluid was statistically significant (P < 0.01). This inferred that Clarke’s fluid is a better nuclear fixative than formal saline. Conclusion: The imminent risks associated with formal saline paved us to explore substitute fixatives, which could provide better results and safety for laboratory workers. Clarke’s fluid is an excellent substitute for formal saline as a nuclear fixative.

CD19-CAR T-cell therapy induces deep tissue depletion of B cells

ObjectivesCD19-targeting chimeric antigen receptor (CAR) T-cell therapy can induce long-term drug-free remission in patients with autoimmune diseases (AIDs). The efficacy of CD19-CAR T-cell therapy is presumably based on deep tissue...

Shear-wave elastography as a supplementary tool for axillary staging in patients undergoing breast cancer diagnosis

BackgroundPreoperative evaluation of axillary lymph node status is crucial for the selection of both systemic and surgical treatment in early breast cancer. This study assessed the particular role of additional shear wave elastography (SWE) in axillary staging in patients undergoing initial breast cancer diagnostics.MethodsOne hundred patients undergoing axillary lymph node biopsy due to a sonographically suspicious axillary lymph node were prospectively evaluated with SWE using virtual touch tissue imaging quantification (VTIQ). Mean values of tissue stiffness for axillary tissue and lymph node tissue were measured prior to core-cut biopsy of the lymph node. All lymph nodes were clip-marked during the biopsy. Cut-off values to differentiate between malignant and benign lymph nodes were defined using Youden’s index.ResultsLymph nodes with evidence of malignant tumor cells in the final pathological examination showed a significantly higher velocity as measured by SWE, with a mean velocity of 3.48 ± 1.58 m/s compared to 2.33 ± 0.62 m/s of benign lymph nodes (p < 0.0001). The statistically optimal cutoff to differentiate between malignant and benign lymph nodes was 2.66 m/s with a sensitivity of 69.8% and a specificity of 87.5%.ConclusionsLymph node metastases assessed with SWE showed significantly higher elasticity values compared to benign lymph nodes. Thus, SWE provides an additional useful and quantifiable parameter for the sonographic assessment of suspicious axillary lymph nodes in the context of pre-therapeutic axillary staging in order to differentiate between benign and metastatic processes and support the guidance of definitive biopsy work-up.Critical relevance statementShear-wave elastography provides an additional useful and quantifiable parameter for the assessment of suspicious axillary lymph nodes in the context of pre-therapeutic axillary staging in order to differentiate between benign and metastatic processes and support guiding the definitive biopsy work-up.Key PointsSWE is a quantifiable ultrasound parameter in breast cancer diagnosis.SWE shows a significantly higher velocity in malignant lymph nodes.SWE is useful in improving the sensitivity and specificity of axillary staging.Graphical