Human Adipose Tissue-Derived Stem Cells Inhibit Coronary Artery Vasculitis in a Mouse Model of Kawasaki Disease.

BACKGROUND: Adipose tissue-derived mesenchymal stem cells (ADSCs) are used for the treatment of various diseases because of their rapid proliferation and high anti-inflammatory and tissue repair properties. Kawasaki disease is a systemic vasculitis with coronary arteritis and aneurysms occurring in pediatric patients. In this study, we examined serologically and pathologically whether the administration of human ADSCs (hADSCs) to a mouse model of Kawasaki disease could suppress vasculitis. METHODS: Candida albicans water-soluble fractions were intraperitoneally injected into DBA/2 mice for 5 consecutive days to generate a mouse model of Kawasaki disease. The model mice were intravenously administered hADSCs or phosphate-buffered saline (PBS). Serum samples collected on days 15 and 29 were used to compare cytokine levels. Mouse hearts dissected on day 29 were subjected to hematoxylin and eosin and immunohistological staining using Galectin-1 (Gal-1), a protein involved in cardiovascular homeostasis, and CD44, a cell-surface marker of hADSCs. RESULTS: Comparison of inflammation-related cytokines showed a significant decrease in IL-1α expression at day 15 (P<0.05) and IL-6 expression at day 29 (P<0.01) in the hADSCs-treated group compared to the PBS group. Evaluation by hematoxylin and eosin staining showed decreased inflammatory cell infiltration and a tendency towards increased Gal-1 expression in the hADSCs group. CD44 expression was not observed in both the groups. The survival curve showed that the hADSCs group had a significantly longer survival time (P<0.05). CONCLUSIONS: The present experimental results indicate that hADSCs have an early anti-inflammatory effect, and that Gal-1 may be involved in preventing inflammation and reducing tissue damage.

Methylation of PLK-1 Potentially Drives Bendamustine Resistance in Leukemia Cells.

BACKGROUND: Drug resistance remains a significant impediment in leukemia treatment. While Bendamustine hydrochloride (BH) stands out as a promising therapeutic agent for non-Hodgkin' s lymphoma and mantle cell lymphoma, the mechanisms of resistance to BH are not yet fully understood. Our study focuses on elucidating the mechanisms behind bendamustine resistance in leukemia cells, with a specific emphasis on epigenetics. METHODS: Bendamustine-resistant cells were cultivated from human B cell lymphoblastic leukemia cell lines through systematic and sustained exposure to bendamustine, using the limiting dilution method. Gene expression was assessed via real-time polymerase chain reaction, while the expression of the multidrug resistance protein 1 (MDR1) was evaluated using flow cytometry. RESULTS: Bendamustine-resistant leukemia cells exhibited a decreased RNA expression level for Polo-like kinase-1 (PLK-1). Notably, after treatment with the demethylating agent 5-aza-2'-deoxycytidine, PLK-1 gene expression surged significantly, enhancing bendamustine's cytotoxicity in the resistant leukemia cells. However, MDR1 expression, as determined by flow cytometry, remained consistent between parental and bendamustine-resistant leukemia cells. CONCLUSIONS: Our findings indicate that the methylation of the PLK-1 gene plays a pivotal role in modulating PLK-1 expression and is central to the development of bendamustine resistance in leukemia cells.

Successful Transcatheter Arterial Embolization to Control Intratumoral Hemorrhage in Clear-Cell Sarcoma of the Kidney.

Clear-cell sarcoma of the kidney (CCSK) is a rare, aggressive pediatric renal tumor. Intratumoral hemorrhage and tumor rupture are oncologic emergencies requiring a rapid and appropriate response. An 11-year-old boy visited our hospital with abdominal distension of 1 month's duration. Computed tomography (CT) revealed a tumor in the left kidney (size: 200 mm), and analysis of a biopsy specimen confirmed a diagnosis of CCSK. Chemotherapy was initiated to shrink the large, densely vascularized tumor before surgical removal. Two days after starting chemotherapy, the patient developed abdominal and back pain, anemia, and hypotension. CT scanning showed intratumoral bleeding. Emergency transcatheter arterial embolization (TAE) was performed to control the bleeding. Three tumor feeding vessels were identified: an ascending branch from the celiac artery, an intermediate branch from the left renal artery, and a descending branch from the inferior mesenteric artery, of which the intermediate and descending branches were large and bleeding profusely. Therefore, the intermediate branch was injected with ethanol, and the descending branch was treated by gel-foam embolization. Chemotherapy was resumed, and the patient's condition gradually stabilized. The tumor began to shrink, and subsequent chemotherapy progressed well. In week 12 of chemotherapy, the patient underwent tumor resection and left nephrectomy. Postoperative chemotherapy was completed without complications, and there was no recurrence during a 6-year follow-up period. Therefore, TAE can effectively control intratumoral bleeding in pediatric solid tumors, thus preventing high-risk open surgery.

Coronavirus disease 2019 and asthma, allergic rhinitis: molecular mechanisms and host-environmental interactions.

PURPOSE OF REVIEW: Coronavirus disease 2019 (COVID-19), a respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus), is a pandemic in over 120 countries worldwide. Risk factors for severe COVID-19 include older age, ethnicity, sex, comorbidities, and living conditions. Although asthmatics and those with allergies are susceptible to more severe outcomes to viral infections, interestingly, asthma has not been reported to be a major comorbidity of COVID-19. However, there are some conflicting reports on the impact of asthma on COVID-19. The underlying immunological and molecular mechanisms may explain at least in part these observations. Furthermore, environmental factors like air pollution that have detrimental effects on asthma and respiratory illnesses also have an impact on COVID-19. RECENT FINDINGS: Angiotensin-converting enzyme 2 (ACE2) is the receptor for the attachment and entry of SARS-CoV-2 into the host cells that is upregulated by Th1-mediated responses. In asthmatics, ACE2 gene expression is generally reduced and recent studies have shown a negative correlation between the levels of Th2 cytokines including IL-4, IL-5, and IL-13 in airway epithelial cells and other type 2 biomarkers with ACE2 expression. This may explain in part the potential protective role of asthma on COVID-19. Here, we review the relation of respiratory viral illnesses and asthma, the immune-molecular mechanisms of SARS-CoV-2 infection, the impact of asthma on COVID-19 and that of SARS-CoV-2 on asthma and allergic rhinitis, and the impact of environmental factors like air pollution on COVID-19. SUMMARY: Expression of ACE2 in airway epithelial cells in SARS-COV-2 is influenced by inflammatory profile. Respiratory allergic diseases like asthma appear to have a protective effect against SARS-COV-2 infection. However, the clinical association between asthma and SARS-COV-2 is not fully established and the underlying immune-molecular mechanisms may explain these observations.

Changes in Cytokine Profile during Initial Treatment of Pediatric Hemophagocytic Lymphohistiocytosis Associated with Epstein-Barr Virus.

Hemophagocytic lymphohistiocytosis (HLH) associated with Epstein-Barr virus (EBV) infection can be self-limiting, severe/aggressive, or fatal. We report a case of EBV-HLH with persistent fever, severe pancytopenia, hypertriglyceridemia, and hypofibrinogenemia in a 4-year-old boy. Levels of plasma cytokines and chemokines were measured with a Bio-Plex system at 1, 2, 3, 4, 5, and 8 days after hospital admission. Administration of steroid and high-dose intravenous immunoglobulin (1 g/kg) did not alleviate fever or reduce cytokine production; however, after administration of etoposide (an antineoplastic agent), fever decreased immediately, the patient's general condition improved, and levels of IL-6, IL-10, IL-8, MCP-1, IFN-γ, and TNF-α declined after etoposide administration. In particular, IFN-γ production sharply declined, from 1,104.1 pg/mL to 101.5 pg/mL, and IL-6 level decreased from 229.8 pg/mL to 11.0 pg/mL, on the day after initial etoposide administration. There was no later recurrence of symptoms during treatment with dexamethasone, etoposide, and cyclosporine A. This case suggests that early etoposide administration is critical for treatment success and indicates that etoposide promptly inhibits cytokine production.

Therapy-related Secondary Malignancy After Treatment of Childhood Malignancy: Cases from a Single Center.

BACKGROUND: Therapeutic outcomes for childhood malignancy have dramatically improved. However, secondary malignancies are a major concern, as they greatly affect the quality of life of survivors. This retrospective study evaluated the cumulative incidence, clinical features, and outcomes of secondary malignancies at Nippon Medical School Hospital. METHODS: We examined data from 275 cases of primary childhood malignancy diagnosed between 1980 and 2014. Information regarding treatment of the primary malignancy, including irradiation dose, site, and cumulative dose of anticancer drugs, was assessed. We also collected data on secondary malignancy, including patient sex, age at diagnosis, malignancy site, time from primary to secondary malignancy, and outcomes. RESULTS: Secondary malignancies developed in 11 patients and included acute myeloid leukemia (AML) (4), meningioma (4), Ewing sarcoma (1), germ cell tumor (1), and malignant parotid gland tumor (1). The primary malignancies included acute lymphoblastic leukemia (ALL) (9), non-Hodgkin lymphoma (1) and brain tumor (1). In 7 of the 9 ALL patients, chemoradiotherapy was the primary treatment. The meningiomas and 1 solid tumor developed within the radiation field. All AMLs and meningiomas developed within 5 years and after 20 years, respectively, of the primary diagnosis. The 10- and 20-year cumulative incidence rates for secondary malignancy in our hospital were 1.9% and 5.8%, respectively. CONCLUSIONS: Our results revealed that the type of secondary malignancy depends on the interval after the end of treatment for primary malignancy. Meningioma, notably, develops many years after completion of primary malignancy treatment. Early detection during long-term follow-up is therefore essential.

[Allogeneic hematopoietic stem cell transplantation using myeloablative conditioning including total body irradiation for pediatric acute lymphoblastic leukemia: a single-center retrospective analysis].

This study aimed to investigate the clinical outcomes of hematopoietic stem cell transplantation (HSCT) with total body irradiation-based myeloablative conditioning (TBI-MAC) in pediatric patients with acute lymphoblastic leukemia (ALL). We retrospectively examined patients with ALL who underwent HSCT with TBI-MAC from January 2000 to August 2016 at our institute. We enrolled 67 patients with a median follow-up period of 8 years. The 5-year event-free survival (EFS) and overall survival (OS) were 51.2% and 59.6%, respectively. At the first complete remission, HSCT exhibited significantly superior EFS and OS in our patients than that in patients with other diseases. We encountered 57.9% of patients with at least one late complication. Major late complications were short stature (26.3%) and hypogonadism (18.4%). While late complications were observed in several recipients of HSCT, late complication-related deaths occurred in three patients. The TBI-MAC regimen led to favorable clinical outcomes in pediatric patients with ALL who underwent HSCT. Thus, proper evaluation and management of late complications are mandatory.

Two cases with bacteremia suspected to be due to relatively rare Pseudomonas (Flavimonas) oryzihabitans.

Pseudomonas oryzihabitans (formerly Flavimonas oryzihabitans) is a glucose non-fermentative, Gram-negative bacillus which is rarely isolated from human specimens. When isolated, it is on very rare occasion as a causative pathogen of catheter-related bloodstream infection in an immunocompromised patient. Herein, we describe two hematological malignancy patients suspected to have P. oryzihabitans bacteremia. We also review cases with bacteremia due to this pathogen and its microbiological characteristics.