A case of atrial septal defect with right-to-left shunting without pulmonary hypertension.

We report a case of a 54-year-old man with atrial septal defect who presented with oxygen desaturation on pulse oximetry. Cardiac magnetic resonance imaging and transesophageal echocardiography showed right-to-left shunting through an atrial septal defect, which was confirmed by superior vena cavography and suggested Eisenmenger syndrome. However, cardiac catheterization revealed a normal pulmonary arterial pressure. Simultaneous measurement of interatrial pressure identified two transient interatrial pressure gradient points, where the right atrial pressure was higher than the left atrial pressure. The patient was finally diagnosed with atrial septal defect without pulmonary hypertension. Right-to-left shunting was primarily caused by a transient interatrial pressure gradient due to a time delay in both initial atrial contraction and completion of passive ventricular filling between the right and left sides of the heart. Surgical closure of the atrial septal defect was performed, and hypoxemia improved. This is the first report of right-to-left shunting without pulmonary hypertension caused by a transient interatrial pressure gradient due to a time delay between the right and left cardiac cycles. Precise assessment of the simultaneous interatrial pressure in addition to diagnostic imaging played a pivotal role in clarifying the etiology of this rare condition. Learning objective: Atrial septal defect with right-to-left shunting without Eisenmenger syndrome is a rare condition. We identified transient interatrial pressure gradients associated with a time delay in both initial atrial contraction and completion of the passive ventricular filling phase, which we considered as the primary mechanism underpinning right-to-left shunting. Simultaneous measurement of interatrial pressure played a pivotal role in elucidating the hemodynamics and abnormal shunt flow mechanism.

Establishment of Mucoepidermoid Carcinoma Cell Lines from Surgical and Recurrence Biopsy Specimens.

Patients with advanced/recurrent mucoepidermoid carcinoma (MEC) have a poor prognosis. This study aimed to establish and characterize human mucoepidermoid carcinoma cell lines from the initial surgical specimen and biopsy specimen upon recurrence from the same patient to provide a resource for MEC research. MEC specimens from the initial surgical procedure and biopsy upon recurrence were used to establish cell lines. The established cell lines were cytogenetically characterized using multi-color fluorescence in situ hybridization and detection, and the sequence of the CRTC1-MAML2 chimeric gene was determined. Furthermore, the susceptibility of head and neck mucoepidermoid carcinoma to standard treatment drugs such as cisplatin, 5-fluorouracil, and cetuximab was investigated. We successfully established unique MEC cell lines, AMU-MEC1, from an initial surgical specimen and AMU-MEC1-R1 and AMU-MEC1-R2 from the recurrent biopsy specimen in the same patient. These cell lines exhibited epithelial morphology and developed in vitro-like cobblestones. They shared eight chromosomal abnormalities, including der(19)ins(19;11)(p13;?), which resulted in a chimeric CRTC1-MAML2 gene, indicating the same origin of the cell lines. The susceptibility of all cell lines to cisplatin and 5-fluorouracil was low. Interestingly, EGFR dependency for cell growth decreased in AMU-MEC-R1 and AMU-MEC-R2 but was retained in AMU-MEC1. These cytogenetic and biochemical findings suggest that the established cell lines can be used to investigate the disease progression mechanisms and develop novel therapeutics for MEC.

Trametinib improves Treg selectivity of anti-CCR4 antibody by regulating CCR4 expression in CTLs in oral squamous cell carcinoma.

Regulatory T-cells (Tregs) play a major role in suppressing anti-tumor immune responses. Mogamulizumab, an anti-CC chemokine receptor type 4 (CCR4) monoclonal antibody, depletes effector Tregs (eTregs). However, the clinical efficacy of mogamulizumab was limited in phase Ia/Ib studies for solid tumors (NCT01929486); the finding suggests that mogamulizumab may also deplete beneficial CCR4+CD8+ T-cells in patients. Therefore, we focused on CTLs and aimed to identify a way to protect CCR4+ CTLs. Here, we evaluated the association of CCR4 expression in cytotoxic T-lymphocytes (CTLs) with antigen and cytokine stimulations and kinase inhibition using cytomegalovirus antigen instead of tumor antigen. CCR4 expression in CTLs was induced by antigen stimulation (mean 3.14-29.0%), enhanced by transforming growth factor-ß1 (TGF-ß1) (mean 29.0-51.2%), and downregulated by trametinib with (mean 51.2-11.4%) or without TGF-ß1 treatment (mean 29.0-6.98%). Phosphorylation of ERK in CD8+ T-cells was suppressed by trametinib. Regarding the effect on immunological function of CTL, trametinib reduced cytokine production but not affected cytotoxicity. Importantly, trametinib alleviated CTL reduction by anti-CCR4 antibody without affecting eTreg depletion because CCR4 expression in eTregs was not downregulated. In conclusion, combination therapy with trametinib may improve the clinical efficacy of mogamulizumab.

MALT lymphoma of the sublingual gland: A case report with current overview of diagnostic and therapeutic strategies.

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is a low-grade B-cell lymphoma. MALT lymphomas involving the sublingual gland are extremely rare. Herein, we report a case of MALT lymphoma of the sublingual gland. Additionally, we discuss challenging diagnostic aspects as well as current treatment strategies.

Essential thrombocythemia complicated with simultaneous two-vessel acute myocardial infarction in the subacute phase of takotsubo cardiomyopathy: A case report.

We report the case of a 79-year-old woman with essential thrombocythemia who presented with simultaneous two-vessel acute myocardial infarction (AMI) in the subacute phase of takotsubo cardiomyopathy. Despite sufficient anticoagulation therapy with warfarin to prevent thrombus formation in the left ventricle, the patient developed simultaneous two-vessel AMI in the right and left circumflex coronary arteries 16 days after the onset of takotsubo cardiomyopathy. Thromboembolism from the left ventricle associated with takotsubo cardiomyopathy was considered a potential cause of this event. However, macroscopic and pathological findings of the aspirated thrombi revealed that the primary cause of AMI was non-organized white platelet thrombi associated with essential thrombocythemia. In addition to oral anticoagulation therapy with warfarin, low-dose aspirin was started. The patient was discharged without any symptoms, and the clinical course has been uneventful for >5 years. This case highlights the potential risk of fatal complications associated with essential thrombocythemia, including simultaneous multivessel AMI. Additionally, pathological findings of the thrombi may play a crucial role in clarifying the etiology in such complicated cases. Appropriate antithrombotic therapy should be selected according to the pathogenesis of the condition. Learning objective: We describe a 79-year-old woman with essential thrombocythemia complicated with simultaneous two-vessel acute myocardial infarction (AMI) in the subacute phase of takotsubo cardiomyopathy. Although patients with essential thrombocythemia are highly predisposed to thrombotic events including AMI, the appropriate antithrombotic regimen remains controversial. The macroscopic and pathological findings of the thrombi play a pivotal role in clarifying the etiology, which may lead to the appropriate antithrombotic therapy.

In Situ PD-L1 Expression in Oral Squamous Cell Carcinoma Is Induced by Heterogeneous Mechanisms among Patients.

The expression of programmed death ligand-1 (PD-L1) is controlled by complex mechanisms. The elucidation of the molecular mechanisms of PD-L1 expression is important for the exploration of new insights into PD-1 blockade therapy. Detailed mechanisms of the in situ expression of PD-L1 in tissues of oral squamous cell carcinomas (OSCCs) have not yet been clarified. We examined the mechanisms of PD-L1 expression focusing on the phosphorylation of downstream molecules of epidermal growth factor (EGF) and interferon gamma (IFN-γ) signaling in vitro and in vivo by immunoblotting and multi-fluorescence immunohistochemistry (MF-IHC), respectively. The in vitro experiments demonstrated that PD-L1 expression in OSCC cell lines is upregulated by EGF via the EGF receptor (EGFR)/PI3K/AKT pathway, the EGFR/STAT1 pathway, and the EGFR/MEK/ERK pathway, and by IFN-γ via the JAK2/STAT1 pathway. MF-IHC demonstrated that STAT1 and EGFR phosphorylation was frequently shown in PD-L1-positive cases and STAT1 phosphorylation was correlated with lymphocyte infiltration and EGFR phosphorylation. Moreover, the phosphorylation pattern of the related molecules in PD-L1-positive cells differed among the cases investigated. These findings indicate that PD-L1 expression mechanisms differ depending on the tissue environment and suggest that the examination of the tissue environment and molecular alterations of cancer cells affecting PD-L1 expression make it necessary for each patient to choose the appropriate combination drugs for PD-1 blockade cancer treatment.

Early diastolic mitral regurgitation in left ventricular aneurysm.

Diastolic mitral regurgitation is a type of functional mitral regurgitation that develops via a reversal of the left atrioventricular pressure gradient during diastole. This study aimed to explore the mechanism underlying early diastolic mitral regurgitation (EDMR) in patients with left ventricular (LV) aneurysms after anterior myocardial infarction (AMI) by assessing the intraventricular pressure difference using vector flow mapping. We enrolled 23 consecutive patients with LV aneurysms (with and without EDMR) and 15 healthy men as controls. In the control group, LV suction began from the apex during early diastole. In contrast, the blood that pooled in the apical aneurysm during systole generated a relatively higher pressure at the apex than at the basal LV during early diastole; consequently, the pressure reversal phenomenon occurred in the LV. Compared to the EDMR- group, the EDMR + group (n = 7) exhibited a significantly higher diastolic time ratio ([time from the second heart sound to the pressure inversion point]/[total diastolic time]) (P < 0.001). The diastolic time ratio was significantly correlated with log BNP, but not with E/A, E/E', or the left atrial expansion index. In conclusion, EDMR in LV aneurysm may be due to a prolonged diastolic time ratio leading to prolonged pressure inversion in the LV during early diastole.

Improving function of cytotoxic T-lymphocytes by transforming growth factor-ß inhibitor in oral squamous cell carcinoma.

Immunotherapy with immune-checkpoint therapy has recently been used to treat oral squamous cell carcinomas (OSCCs). However, improvements in current immunotherapy are expected because response rates are limited. Transforming growth factor-ß (TGF-ß) creates an immunosuppressive tumor microenvironment (TME) by inducing the production of regulatory T-cells (Tregs) and cancer-associated fibroblasts and inhibiting the function of cytotoxic T-lymphocytes (CTLs) and natural killer cells. TGF-ß may be an important target in the development of novel cancer immunotherapies. In this study, we investigated the suppressive effect of TGF-ß on CTL function in vitro using OSCC cell lines and their specific CTLs. Moreover, TGFB1 mRNA expression and T-cell infiltration in 25 OSCC tissues were examined by in situ hybridization and multifluorescence immunohistochemistry. We found that TGF-ß suppressed the function of antigen-specific CTLs in the priming and effector phases in vitro. Additionally, TGF-ß inhibitor effectively restored the CTL function, and TGFB1 mRNA was primarily expressed in the tumor invasive front. Interestingly, we found a significant negative correlation between TGFB1 mRNA expression and the CD8+ T-cell/Treg ratio and between TGFB1 mRNA expression and the Ki-67 expression in CD8+ T-cells, indicating that TGF-ß also suppressed the function of CTLs in situ. Our findings suggest that the regulation of TGF-ß function restores the immunosuppressive TME to active status and is important for developing new immunotherapeutic strategies, such as a combination of immune-checkpoint inhibitors and TGF-ß inhibitors, for OSCCs.