Management of neonatal and infant aortic thrombosis: A single-center case series.

Neonatal and infant aortic thrombosis is a rare albeit life-threatening thrombotic event, particularly seen in premature infants with an arterial catheter in place. We describe our institutional experience and approach to the management of 11 infants with occlusive or nearly occlusive aortic thrombosis. We observed at least partial thrombus resolution in all patients. Complications related to our management included minor bleeding in two children receiving thrombolytic therapy, and two major bleeding events in children receiving anticoagulation alone. Our experience adds to the growing body of evidence that thrombolysis and thrombectomy should be considered in managing neonatal/infant aortic thrombosis.

Hospital acquired venous thromboembolism in children with sickle cell disease.

Sickle cell disease (SCD) is well recognized as a hypercoagulablestate, however, it remains unclear whether a subgroup of children with SCD at higher risk of venous thromboembolic event (VTE) during hospitalization may benefit from thromboprophylaxis. Our objectives were to describe the clinical characteristics, outcomes and recurrence of hospital acquired VTE in patients with SCD younger than 21 years. This was a single center retrospective study. Data regarding demographics, reason for admission, location of VTE, risk factors like central venous catheter (CVC), intensive care unit (ICU) admission among others were extracted from electronic medical records over a 10-year study period (2011-2021). Recurrence of VTE at 1 and 5 years was assessed. Descriptive statistics were used as indicated. We identified a total of 20 VTE events over the 10-year study period. Six of these events occurred in those younger than 12 years of age. Fourteen (70%) VTE events occurred in the HbSS or HbSßThal0 genotypes compared to 6 (30%) in HbSC. Most common VTE was isolated pulmonary embolism (PE) (n = 10, 50%). VTE were most often associated with acute chest syndrome (ACS) (n = 14, 70%), ICU admissions (n = 10, 50%) and CVC (n = 5/9, 55%). One patient died from the VTE event. One patient with additional underlying risk factors had a recurrent VTE at 13 months. Our study suggests that ICU admission, ACS and presence of CVC increases the risk of VTE in children and young adults with SCD, but larger studies are indicated to validate our findings.

Two-year carcinogenicity study of a novel plasticizer, bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (Eco-DEHCH), by oral diet in Han Wistar rats.

Plasticizers are necessary for the usability of various products, including food contact materials. Exposure to plasticizers is most commonly made through the oral route. Several plasticizers have been reported to have adverse effects on humans and the environment. Thus, the present study aimed to determine the long-term toxicity and carcinogenicity of a novel plasticizer called bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (Eco-DEHCH), which is an ecofriendly and biologically less harmful replacer. Groups of 50 male and 50 female Han Wistar rats were fed Eco-DEHCH at daily doses of 1,600, 5,000, or 16,000 ppm in their diet for at least 104 weeks. The rats were regularly monitored for mortality, clinical signs, body weight, food consumption, food efficiency, and perceivable mass. All animals were subjected to complete necropsy and histopathological examination. The results indicate that the rats well tolerated chronic exposure to Eco-DEHCH at highest daily doses of 16,000 ppm, with was equivalent to 805.1 mg/kg/day in males and 1060.6 mg/kg/day in females and did not show signs of toxicity or carcinogenicity. In conclusion, Eco-DEHCH could be a safe and promising alternative plasticizer.

Hematopoietic stem and progenitor cells confer cross-protective trained immunity in mouse models.

Recent studies suggest that infection reprograms hematopoietic stem and progenitor cells (HSPCs) to enhance innate immune responses upon secondary infectious challenge, a process called "trained immunity." However, the specificity and cell types responsible for this response remain poorly defined. We established a model of trained immunity in mice in response to Mycobacterium avium infection. scRNA-seq analysis revealed that HSPCs activate interferon gamma-response genes heterogeneously upon primary challenge, while rare cell populations expand. Macrophages derived from trained HSPCs demonstrated enhanced bacterial killing and metabolism, and a single dose of recombinant interferon gamma exposure was sufficient to induce similar training. Mice transplanted with influenza-trained HSPCs displayed enhanced immunity against M. avium challenge and vice versa, demonstrating cross protection against antigenically distinct pathogens. Together, these results indicate that heterogeneous responses to infection by HSPCs can lead to long-term production of bone marrow derived macrophages with enhanced function and confer cross-protection against alternative pathogens.

The Common Marmoset-Biomedical Research Animal Model Applications and Common Spontaneous Diseases.

Marmosets are becoming more utilized in biomedical research due to multiple advantages including (1) a nonhuman primate of a smaller size with less cost for housing, (2) physiologic similarities to humans, (3) translatable hepatic metabolism, (4) higher numbers of litters per year, (5) genome is sequenced, molecular reagents are available, (6) immunologically similar to humans, (7) transgenic marmosets with germline transmission have been produced, and (8) are naturally occurring hematopoietic chimeras. With more use of marmosets, disease surveillance over a wide range of ages of marmosets has been performed. This has led to a better understanding of the disease management of spontaneous diseases that can occur in colonies. Knowledge of clinical signs and histologic lesions can assist in maximizing the colony's health, allowing for improved outcomes in translational studies within biomedical research. Here, we describe some basic husbandry, biology, common spontaneous diseases, and animal model applications for the common marmoset in biomedical research.

The bacterial microbiota regulates normal hematopoiesis via metabolite-induced type 1 interferon signaling.

Antibiotic therapy, especially when administered long term, is associated with adverse hematologic effects such as cytopenia. Signals from the intestinal microbiota are critical to maintain normal hematopoiesis, and antibiotics can cause bone marrow suppression through depletion of the microbiota. We reported previously that STAT1 signaling is necessary for microbiota-dependent hematopoiesis, but the precise mechanisms by which the gut microbiota signals to the host bone marrow to regulate hematopoiesis remain undefined. We sought to identify the cell type(s) through which STAT1 promotes microbiota-mediated hematopoiesis and to elucidate which upstream signaling pathways trigger STAT1 signaling. Using conditional knockout and chimeric mice, we found that the microbiota induced STAT1 signaling in non-myeloid hematopoietic cells to support hematopoiesis and that STAT1 signaling was specifically dependent on type I interferons (IFNs). Indeed, basal type I IFN signaling was reduced in hematopoietic progenitor cells with antibiotic treatment. In addition, we discovered that oral administration of a commensal-derived product, NOD1 ligand, rescues the hematopoietic defects induced by antibiotics in mice. Using metabolomics, we identified additional microbially produced candidates that can stimulate type I IFN signaling to potentially rescue the hematopoietic defects induced by antibiotics, including phosphatidylcholine and γ-glutamylalanine. Overall, our studies define a signaling pathway through which microbiota promotes normal hematopoiesis and identify microbial metabolites that may serve as therapeutic agents to ameliorate antibiotic-induced bone marrow suppression and cytopenia.

Broad-Spectrum Antibiotics Deplete Bone Marrow Regulatory T Cells.

Bone marrow suppression, including neutropenia, is a major adverse effect of prolonged antibiotic use that impairs the clinical care and outcomes of patients with serious infections. The mechanisms underlying antibiotic-mediated bone marrow suppression remain poorly understood, with initial evidence indicating that depletion of the intestinal microbiota is an important factor. Based on our earlier studies of blood and bone marrow changes in a mouse model of prolonged antibiotic administration, we studied whether changes in megakaryocytes or regulatory T cells (Tregs), two cell types that are critical in the maintenance of hematopoietic stem cells, contribute to antibiotic-mediated bone marrow suppression. Despite increased platelet numbers, megakaryocytes were unchanged in the bone marrow of antibiotic-treated mice; however, Tregs were found to be significantly depleted. Exogenous addition of Tregs was insufficient to rescue the function of bone marrow from antibiotic-treated mice in both colony formation and transplantation assays. These findings indicate that the intestinal microbiota support normal Treg development to protect healthy hematopoiesis, but that the restoration of Tregs alone is insufficient to restore normal bone marrow function.

PKM2 in Canine Mammary Tumors: Parallels to Human Breast Cancer.

PKM2 is a pyruvate kinase isoform that is the final and rate-limiting step in aerobic glycolysis in tumor cells. Increased expression of PKM2 has been detected in human cancers. The present study examined the expression of PKM2 in canine mammary tumors and assessed its prognostic significance. Paraffin sections of 5 adenomas, 67 carcinomas, and 5 samples of nonneoplastic hyperplasia from 77 dogs, aged 8 to 18 y, were evaluated. Significantly higher levels of PKM2 were detected among the carcinomas compared with all other tissues examined. The level of PKM2 expression in carcinoma tissue correlated positively with the tumor grade. These findings suggest that PKM2 may have a similar role in canine mammary tumors to its role in human breast cancer. As such, canine mammary tumors may be useful models for studies focused on the progression of human neoplastic disease.

Transient Abnormal Myelopoeisis and Mosaic Down Syndrome in a Phenotypically Normal Newborn.

Transient abnormal myelopoiesis (TAM) is a common and potentially fatal neonatal complication of newborn babies with Down syndrome (DS). Children born with mosaic DS are also at risk of developing TAM. However, due to their variable phenotypes, early identification of patients with mosaic DS may be difficult; thus, early diagnosis of TAM is just as challenging. In this report, we describe a case of a phenotypically normal newborn who presented with concerns for neonatal leukemia. The diagnosis of mosaic DS and TAM was confirmed with abnormal GATA1 mutation testing, highlighting the importance of early GATA1 mutation testing in newborn leukemia with high suspicion for TAM.

Use of 3D Human Liver Organoids to Predict Drug-Induced Phospholipidosis.

Drug-induced phospholipidosis (PL) is a storage disorder caused by the formation of phospholipid-drug complexes in lysosomes. Because of the diversity of PL between species, human cell-based assays have been used to predict drug-induced PL in humans. We established three-dimensional (3D) human liver organoids as described previously and investigated their liver characteristics through multiple analyses. Drug-induced PL was initiated in these organoids and in monolayer HepG2 cultures, and cellular changes were systemically examined. Organoids that underwent differentiation showed characteristics of hepatocytes rather than HepG2 cells. The organoids also survived under PL-inducing drug conditions for 48 h and maintained a more stable albumin secretion level than the HepG2 cells. More cytoplasmic vacuoles were observed in organoids and HepG2 cells treated with more potent PL-induced drugs, but to a greater extent in organoids than in HepG2 cells. Lysosome-associated membrane protein 2, a marker of lysosome membranes, showed a stronger immunohistochemical signal in the organoids. PL-distinctive lamellar bodies were observed only in amiodarone-treated organoids by transmission electron microscopy. Human liver organoids are thus more sensitive to drug-induced PL and less affected by cytotoxicity than HepG2 cells. Since PL is a chronic condition, these results indicate that organoids better reflect metabolite-mediated hepatotoxicity in vivo and could be a valuable system for evaluating the phospholipidogenic effects of different compounds during drug development.

BCOR-CCNB3 fusion-positive clear cell sarcoma of the kidney.

Clear cell sarcoma of the kidney (CCSK) is the second most common malignant pediatric renal tumor. Two of the recurrent somatic alterations reported in CCSK are BCL-6 corepressor (BCOR) internal tandem duplication (ITD) and YWHAE-NUTM2B/E gene fusion. A minority of patients with CCSKs have other rare somatic alterations. We report two patients with CCSK showing BCOR-CCNB3 (where CCNB3 is cyclin B3) fusion, who had similar clinical presentation of a large renal mass with tumor thrombus extending through the inferior vena cava into the right atrium and a favorable response to chemotherapy. We recommend BCOR-CCNB3 fusion testing for all patients with CCSK who lack BCOR-ITD or YWHAE-NUTM2B/E gene fusions.

EZH2 Expression in Naturally Occurring Canine Tumors.

Enhancer of zeste homolog 2 (EZH2) shows upregulated expression in tumors and is an important driver of tumor development and progression. However, the mechanism underlying the mediation of tumor aggressiveness by EZH2 remains unclear. We here investigated the levels of EZH2 in various normal and tumorous dog tissues and compared these patterns with those of the corresponding human tissues. Immunohistochemical analysis showed positive staining for EZH2 in 76 of 82 cases of canine tumors, whereas low or negligible staining occurred in normal tissues and other canine tumors, including hepatocellular adenoma and lipoma. In particular, canine lymphoma, melanoma, basal cell tumors, squamous cell carcinoma, and prostate cancer all show EZH2 overexpression, as do their human counterparts. Given the similarities of spontaneous canine tumors to human cancers, we believe that these canine tumors can be used as animal models in future research and clinical trials in the development of EZH2 inhibitors.

Multireaction monitoring of 12 peptides for lowered immunity screening.

A multireaction monitoring method using high-performance liquid chromatography-tandem mass spectrometry was developed for 12 target peptides for determination of endogenous peptide concentrations in human serum. Chromatographic separation conditions were optimized and recoveries for liquid-liquid extraction, solid-phase extraction (SPE), and ultrafiltration of endogenous peptides from human serum were compared, and the SPE method was selected for 12 targeted peptide extractions. The optimized SPE method gave recoveries higher than 60 % for all targeted peptides. The limit of detection was 10 ng/ml for most peptides, except for N-formyl-methionyl-leucyl-phenylalanine (NFMLP) and adrenocorticotropic hormone (ACTH) (18-39). The limit of detection for these two peptides was 1 ng/ml. The real serum samples of 25 elderly and 23 young people were analyzed using the optimized extraction and analysis method. Half of the 12 peptides were below the limit of quantification, and B-type natriuretic peptide, cholecystokinin, ACTH(7-38), substance P, NFMLP, and valyl-glutamyl-prolyl-isoleucyl-prolyl-tyrosine were quantified in the concentration range from 0.1 to 50 ng/ml. The concentration of ACTH(7-38) was significantly higher in elderly people and that of NFMLP was significantly lower in elderly people compared with young people (p < 0.0001). This result implies that there be a possible relationships between ACTH, NFMLP and lowered immunity.