Biliary Disorders, Anomalies, and Malignancies in Children.

Biliary abnormalities in children are uncommon, and the spectrum of biliary disorders is broader than in adult patients. Unlike in adults, biliary disorders in children are rarely neoplastic and are more commonly rhabdomyosarcoma rather than cholangiocarcinoma. Pediatric biliary disorders may be embryologic or congenital, such as anatomic gallbladder anomalies, anomalous pancreaticobiliary tracts, various cholestatic processes, congenital cystic lesions, or genetic conditions. They may also be benign, such as biliary filling anomalies, biliary motility disorders, and biliary inflammatory and infectious disorders. Distinguishing these entities with a single imaging modality is challenging. US is the primary imaging modality for initial evaluation of biliary abnormalities in children, due to its wide availability, lack of ionizing radiation, and low cost and because it requires no sedation. Other examinations such as MRI, CT, and nuclear medicine examinations may provide anatomic and functional information to narrow the diagnosis further. Hepatobiliary-specific contrast material with MRI can provide better assessment of biliary anatomy on delayed images than can traditional MRI contrast material. MR cholangiopancreatography (MRCP) allows visualization of the intra- and extrahepatic biliary ducts, which may not be possible with endoscopic retrograde cholangiopancreatography (ERCP). Suspected biliary atresia requires multiple modalities for diagnosis and timely treatment. Determining the type of choledochal cyst calls for a combination of initial US and MRCP. Many benign and malignant biliary masses require biopsy for definitive diagnosis. Knowledge of the imaging appearances of different pediatric biliary abnormalities is necessary for appropriate imaging workup, providing a diagnosis or differential diagnosis, and guiding appropriate management. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Decoding the IGF1 signaling gene regulatory network behind alveologenesis from a mouse model of bronchopulmonary dysplasia.

Lung development is precisely controlled by underlying gene regulatory networks (GRN). Disruption of genes in the network can interrupt normal development and cause diseases such as bronchopulmonary dysplasia (BPD) - a chronic lung disease in preterm infants with morbid and sometimes lethal consequences characterized by lung immaturity and reduced alveolarization. Here, we generated a transgenic mouse exhibiting a moderate severity BPD phenotype by blocking IGF1 signaling in secondary crest myofibroblasts (SCMF) at the onset of alveologenesis. Using approaches mirroring the construction of the model GRN in sea urchin's development, we constructed the IGF1 signaling network underlying alveologenesis using this mouse model that phenocopies BPD. The constructed GRN, consisting of 43 genes, provides a bird's eye view of how the genes downstream of IGF1 are regulatorily connected. The GRN also reveals a mechanistic interpretation of how the effects of IGF1 signaling are transduced within SCMF from its specification genes to its effector genes and then from SCMF to its neighboring alveolar epithelial cells with WNT5A and FGF10 signaling as the bridge. Consistently, blocking WNT5A signaling in mice phenocopies BPD as inferred by the network. A comparative study on human samples suggests that a GRN of similar components and wiring underlies human BPD. Our network view of alveologenesis is transforming our perspective to understand and treat BPD. This new perspective calls for the construction of the full signaling GRN underlying alveologenesis, upon which targeted therapies for this neonatal chronic lung disease can be viably developed.

Educational intervention to adopt selective laser trabeculoplasty as first-line glaucoma treatment: Randomized controlled trial: Educational intervention on selective laser trabeculoplasty.

PURPOSE: To determine the efficacy of an educational intervention on patient adoption and attitudes toward selective laser trabeculoplasty (SLT) as first-line treatment for glaucoma. METHODS: This study is a randomized controlled trial. Subjects include 33 patients within 1-year diagnosis of either primary open-angle glaucoma, ocular hypertension, or pseudoexfoliation syndrome. After informed consent, subjects were randomly assigned to a Usual Care or Educational Intervention group. All subjects completed a pre-intervention questionnaire. The Educational Intervention group was shown a slideshow presentation and a 3-min video and given a post-intervention questionnaire. Follow-up examinations were reviewed for 6 months to determine subject completion of SLT, the primary outcome. Secondary outcomes include assessment of attitude toward SLT before and after intervention. RESULTS: Age, gender, and baseline characteristics between the groups did not differ. The Usual Care group had a higher proportion of African Americans (77% vs 31%, p = 0.04). At 6 months following the intervention, 63% of subjects underwent SLT compared to 35% of Usual Care subjects (p = 0.12). Older age was associated with decreased SLT uptake (OR 0.90, 95% CI 0.82-0.99, p = 0.03). Prior to the intervention, there were no differences in attitudes of both groups regarding SLT therapy. Nineteen percent of Educational Intervention subjects changed positively toward SLT (p = 0.08) and 50% scheduled an SLT appointment after intervention (p = 0.005). CONCLUSIONS: A slideshow and video-based educational intervention may positively enhance patient adoption of SLT.Clinical trial registration name, number, URL: Educational Intervention to Adopt SLT as First-Line Glaucoma Treatment, NCT03365778, https://clinicaltrials.gov/ct2/show/NCT03365778.

Hospital admission as a deprescribing triage point for patients discharged to Residential Aged Care Facilities.

BACKGROUND: Deprescribing may benefit older frail patients experiencing polypharmacy. We investigated the scope for deprescribing in acutely hospitalised patients and the long-term implications of continuation of medications that could potentially be deprescribed. METHODS: Acutely hospitalised patients (n = 170) discharged to Residential Aged Care Facilities, ≥75 years and receiving ≥5 regular medications were assessed during admission to determine eligibility for deprescribing of key drug classes, along with the actual incidence of deprescribing. The impact of continuation of nominated drug classes (anticoagulants, antidiabetics, antiplatelets, antipsychotics, benzodiazepines, proton pump inhibitors (PPIs), statins) on a combined endpoint (death/readmission) was determined. RESULTS: Hyperpolypharmacy (>10 regular medications) was common (49.4%) at admission. Varying rates of deprescribing occurred during hospitalisation for the nominated drug classes (8-53%), with considerable potential for further deprescribing (34-90%). PPI use was prevalent (56%) and 89.5% of these had no clear indication. Of the drug classes studied, only continued PPI use at discharge was associated with increased mortality/readmission at 1 year (hazard ratio 1.54, 95% confidence interval (1.06-2.26), P = 0.025), driven largely by readmission. CONCLUSION: There is considerable scope for acute hospitalisation to act as a triage point for deprescribing in older patients. PPIs in particular appeared overprescribed in this susceptible patient group, and this was associated with earlier readmission. Polypharmacy in older hospitalised patients should be targeted for possible deprescribing during hospitalisation, especially PPIs.

Beliefs and Attitudes of Ophthalmologists Regarding SLT as First Line Therapy for Glaucoma.

PRECIS: Targeted educational interventions for physicians may be useful in increasing adoption of selective laser trabeculoplasty (SLT) as first line therapy for the treatment of glaucoma. PURPOSE: SLT is a safe and effective first line treatment for glaucoma, however, it is underutilized. To evaluate barriers for the widespread adoption of this procedure, we assessed the beliefs and attitudes of ophthalmologists. We developed an educational intervention directed to physicians to increase the consideration of SLT earlier in the glaucoma treatment paradigm. SUBJECTS AND METHODS: In this prospective study, an online survey and educational slide presentation was sent to a group of comprehensive ophthalmologists, ophthalmology residents, and glaucoma specialists. Subjects were asked to respond to questions regarding their beliefs and attitudes towards SLT before and after watching the educational slide presentation. RESULTS: A total of 53 subjects were enrolled. Before watching the slide presentation, 85% of subjects stated they offer SLT to newly diagnosed patients, although only 28% preferred it over medications. While 52% of physicians reported between 0% and 10% of their newly diagnosed patients receive laser therapy, 47% said they would use it as a first line therapy for all or most newly diagnosed glaucoma patients. Most subjects (94%) stated the educational slide presentation convinced them that SLT is appropriate as a first line therapy for treatment of open angle glaucoma. CONCLUSIONS: A better understanding of the barriers for utilizing SLT as a first line therapy provides valuable information to help increase the adoption of this safe and effective procedure. A targeted educational intervention may improve acceptance of SLT as first line therapy for open angle glaucoma.

Wild-type Kras expands and exhausts hematopoietic stem cells.

Oncogenic Kras expression specifically in hematopoietic stem cells (HSCs) induces a rapidly fatal myeloproliferative neoplasm in mice, suggesting that Kras signaling plays a dominant role in normal hematopoiesis. However, such a conclusion is based on expression of an oncogenic version of Kras. Hence, we sought to determine the effect of simply increasing the amount of endogenous wild-type Kras on HSC fate. To this end, we utilized a codon-optimized version of the murine Kras gene (Krasex3op) that we developed, in which silent mutations in exon 3 render the encoded mRNA more efficiently translated, leading to increased protein expression without disruption to the normal gene architecture. We found that Kras protein levels were significantly increased in bone marrow (BM) HSCs in Krasex3op/ex3op mice, demonstrating that the translation of Kras in HSCs is normally constrained by rare codons. Krasex3op/ex3op mice displayed expansion of BM HSCs, progenitor cells, and B lymphocytes, but no evidence of myeloproliferative disease or leukemia in mice followed for 12 months. BM HSCs from Krasex3op/ex3op mice demonstrated increased multilineage repopulating capacity in primary competitive transplantation assays, but secondary competitive transplants revealed exhaustion of long-term HSCs. Following total body irradiation, Krasex3op/ex3op mice displayed accelerated hematologic recovery and increased survival. Mechanistically, HSCs from Krasex3op/ex3op mice demonstrated increased proliferation at baseline, with a corresponding increase in Erk1/2 phosphorylation and cyclin-dependent kinase 4 and 6 (Cdk4/6) activation. Furthermore, both the enhanced colony-forming capacity and in vivo repopulating capacity of HSCs from Krasex3op/ex3op mice were dependent on Cdk4/6 activation. Finally, BM transplantation studies revealed that augmented Kras expression produced expansion of HSCs, progenitor cells, and B cells in a hematopoietic cell-autonomous manner, independent from effects on the BM microenvironment. This study provides fundamental demonstration of codon usage in a mammal having a biological consequence, which may speak to the importance of codon usage in mammalian biology.

Endobronchial Ultrasound-guided Transbronchial Needle Injection of Liposomal Amphotericin B for the Treatment of Symptomatic Aspergilloma.

Surgical treatment with lung resection has traditionally been the treatment of choice for pulmonary cavities containing aspergillomas that cause hemoptysis. Endobronchial ultrasound (EBUS) is a minimally invasive bronchoscopic technique that is commonly used for transbronchial needle aspiration of hilar and mediastinal lymph nodes as well as centrally located parenchymal lesions. Here, we describe a case of a 71-year-old woman who was found to have a cavitary lesion in the lung containing aspergillomas. Under direct ultrasound visualization with EBUS, liposomal amphotericin B was injected into the aspergillomas. These aspergillomas regressed after treatment. To our knowledge, this is the first reported treatment of aspergilloma with EBUS-guided transbronchial needle injection of liposomal amphotericin B.

Dickkopf-1 promotes hematopoietic regeneration via direct and niche-mediated mechanisms.

The role of osteolineage cells in regulating hematopoietic stem cell (HSC) regeneration following myelosuppression is not well understood. Here we show that deletion of the pro-apoptotic genes Bak and Bax in osterix (Osx, also known as Sp7 transcription factor 7)-expressing cells in mice promotes HSC regeneration and hematopoietic radioprotection following total body irradiation. These mice showed increased bone marrow (BM) levels of the protein dickkopf-1 (Dkk1), which was produced in Osx-expressing BM cells. Treatment of irradiated HSCs with Dkk1 in vitro increased the recovery of both long-term repopulating HSCs and progenitor cells, and systemic administration of Dkk1 to irradiated mice increased hematopoietic recovery and improved survival. Conversely, inducible deletion of one allele of Dkk1 in Osx-expressing cells in adult mice inhibited the recovery of BM stem and progenitor cells and of complete blood counts following irradiation. Dkk1 promoted hematopoietic regeneration via both direct effects on HSCs, in which treatment with Dkk1 decreased the levels of mitochondrial reactive oxygen species and suppressed senescence, and indirect effects on BM endothelial cells, in which treatment with Dkk1 induced epidermal growth factor (EGF) secretion. Accordingly, blockade of the EGF receptor partially abrogated Dkk1-mediated hematopoietic recovery. These data identify Dkk1 as a regulator of hematopoietic regeneration and demonstrate paracrine cross-talk between BM osteolineage cells and endothelial cells in regulating hematopoietic reconstitution following injury.

Cross-Species Transcriptome Profiling Identifies New Alveolar Epithelial Type I Cell-Specific Genes.

Diseases involving the distal lung alveolar epithelium include chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and lung adenocarcinoma. Accurate labeling of specific cell types is critical for determining the contribution of each to the pathogenesis of these diseases. The distal lung alveolar epithelium is composed of two cell types, alveolar epithelial type 1 (AT1) and type 2 (AT2) cells. Although cell type-specific markers, most prominently surfactant protein C, have allowed detailed lineage tracing studies of AT2 cell differentiation and the cells' roles in disease, studies of AT1 cells have been hampered by a lack of genes with expression unique to AT1 cells. In this study, we performed genome-wide expression profiling of multiple rat organs together with purified rat AT2, AT1, and in vitro differentiated AT1-like cells, resulting in the identification of 54 candidate AT1 cell markers. Cross-referencing with genes up-regulated in human in vitro differentiated AT1-like cells narrowed the potential list to 18 candidate genes. Testing the top four candidate genes at RNA and protein levels revealed GRAM domain 2 (GRAMD2), a protein of unknown function, as highly specific to AT1 cells. RNA sequencing (RNAseq) confirmed that GRAMD2 is transcriptionally silent in human AT2 cells. Immunofluorescence verified that GRAMD2 expression is restricted to the plasma membrane of AT1 cells and is not expressed in bronchial epithelial cells, whereas reverse transcription-polymerase chain reaction confirmed that it is not expressed in endothelial cells. Using GRAMD2 as a new AT1 cell-specific gene will enhance AT1 cell isolation, the investigation of alveolar epithelial cell differentiation potential, and the contribution of AT1 cells to distal lung diseases.

Deletion of the Imprinted Gene Grb10 Promotes Hematopoietic Stem Cell Self-Renewal and Regeneration.

Imprinted genes are differentially expressed by adult stem cells, but their functions in regulating adult stem cell fate are incompletely understood. Here we show that growth factor receptor-bound protein 10 (Grb10), an imprinted gene, regulates hematopoietic stem cell (HSC) self-renewal and regeneration. Deletion of the maternal allele of Grb10 in mice (Grb10m/+ mice) substantially increased HSC long-term repopulating capacity, as compared to that of Grb10+/+ mice. After total body irradiation (TBI), Grb10m/+ mice demonstrated accelerated HSC regeneration and hematopoietic reconstitution, as compared to Grb10+/+ mice. Grb10-deficient HSCs displayed increased proliferation after competitive transplantation or TBI, commensurate with upregulation of CDK4 and Cyclin E. Furthermore, the enhanced HSC regeneration observed in Grb10-deficient mice was dependent on activation of the Akt/mTORC1 pathway. This study reveals a function for the imprinted gene Grb10 in regulating HSC self-renewal and regeneration and suggests that the inhibition of Grb10 can promote hematopoietic regeneration in vivo.

RAD001 (everolimus) inhibits tumour growth in xenograft models of human hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide and highly resistant to available chemotherapies. Mammalian target of rapamycin (mTOR) functions to regulate protein translation, angiogenesis and cell cycle progression in many cancers including HCC. In the present study, subcutaneous patient-derived HCC xenografts were used to study the effects of an mTOR inhibitor, RAD001 (everolimus), on tumour growth, apoptosis and angiogenesis. We report that oral administration of RAD001 to mice bearing patient-derived HCC xenografts resulted in a dose-dependent inhibition of tumour growth. RAD001-induced growth suppression was associated with inactivation of downstream targets of mTOR, reduction in VEGF expression and microvessel density, inhibition of cell proliferation, up-regulation of p27(Kip1) and down-regulation of p21(Cip1/Waf1), Cdk-6, Cdk-2, Cdk-4, cdc-25C, cyclin B1 and c-Myc. Our data indicate that the mTOR pathway plays an important role in angiogenesis, cell cycle progression and proliferation of liver cancer cells. Our study provides a strong rationale for clinical investigation of mTOR inhibitor RAD001 in patients with HCC.

Brivanib alaninate, a dual inhibitor of vascular endothelial growth factor receptor and fibroblast growth factor receptor tyrosine kinases, induces growth inhibition in mouse models of human hepatocellular carcinoma.

PURPOSE: Hepatocellular carcinoma (HCC) is the fifth most common primary neoplasm; surgery is the only curative option but 5-year survival rates are only 25% to 50%. Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) are known to be involved in growth and neovascularization of HCC. Therefore, agents that target these pathways may be effective in the treatment of HCC. The aim of this study was to determine the antineoplastic activity of brivanib alaninate, a dual inhibitor of VEGF receptor (VEGFR) and FGF receptor (FGFR) signaling pathways. EXPERIMENTAL DESIGN: Six different s.c. patient-derived HCC xenografts were implanted into mice. Tumor growth was evaluated in mice treated with brivanib compared with control. The effects of brivanib on apoptosis and cell proliferation were evaluated by immunohistochemistry. The SK-HEP1 and HepG2 cells were used to investigate the effects of brivanib on the VEGFR-2 and FGFR-1 signaling pathways in vitro. Western blotting was used to determine changes in proteins in these xenografts and cell lines. RESULTS: Brivanib significantly suppressed tumor growth in five of six xenograft lines. Furthermore, brivanib-induced growth inhibition was associated with a decrease in phosphorylated VEGFR-2 at Tyr(1054/1059), increased apoptosis, reduced microvessel density, inhibition of cell proliferation, and down-regulation of cell cycle regulators. The levels of FGFR-1 and FGFR-2 expression in these xenograft lines were positively correlated with its sensitivity to brivanib-induced growth inhibition. In VEGF-stimulated and basic FGF stimulated SK-HEP1 cells, brivanib significantly inhibited VEGFR-2, FGFR-1, extracellular signal-regulated kinase 1/2, and Akt phosphorylation. CONCLUSION: This study provides a strong rationale for clinical investigation of brivanib in patients with HCC.

Targeted inhibition of the extracellular signal-regulated kinase kinase pathway with AZD6244 (ARRY-142886) in the treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common malignancy in Asia and Africa. We previously reported that overexpression of extracellular signal-regulated kinase (ERK) kinase 1/2 (MEK1/2) and ERK1/2 was detected in HCC, and that their activation was required for liver cancer cell proliferation and survival. In the present study, we determined the efficacy of a specific MEK1/2 inhibitor AZD6244 (ARRAY-142886) in treatment of HCC. Treatment of primary HCC cells with AZD6244 led to growth inhibition, elevation of the cleavage of caspase-3 and caspase-7, and cleaved poly(ADP)ribose polymerase, but inhibition of ERK1/2 and p90RSK phosphorylation. Studying the protein expression profile of seven HCC xenografts revealed that their growth rate was positively correlated with the levels of phosphorylated MEK. AZD6244, when given p.o. to mice bearing these xenografts, resulted in a dose-dependent inhibition of tumor growth. AZD6244-induced growth suppression was associated with inactivation of ERK1/2 and p90RSK, and up-regulation of activated caspase-3 and caspase-7, and cleaved poly(ADP)ribose polymerase. Our data suggest that the MEK-ERK pathway plays an important role in the growth and survival of liver cancer cells and that the HCC xenograft models are excellent tools for screening preclinical drugs. Targeted inhibition of the MEK-ERK pathway with AZD6244 may represent an alternative approach for the treatment of this disease.

Xenografts of human hepatocellular carcinoma: a useful model for testing drugs.

PURPOSE: Our aims were to establish and characterize primary human hepatocellular carcinoma xenografts. They were used to screen new drugs and improve our current treatment regimens used in hepatocellular carcinoma. EXPERIMENTAL DESIGN: Primary hepatocellular carcinomas were used to create the xenografts. Western blotting was used to determine the changes in proteins in these xenografts before and after therapies. Apoptotic and cell proliferation were analyzed by immunohistochemistry. RESULTS: Seven lines of xenografts were established from primary human hepatocellular carcinomas. Lines 4-1318, 2-1318, 2006, and 26-1004 grew rapidly in severe combined immunodeficient (SCID) mice and doubled its volume every 48 to 72 hours. Series 5-1318 (5-1318, 30-1004, and 29-1104) grew relatively slowly in SCID mice and required approximately 6 to 10 days to double its tumor volume. Western blot analysis revealed that the growth rate of these xenografts was associated with abnormal expression of proteins associated with the cell cycle, signaling pathways, and tumor suppressor genes. Although hepatocellular carcinoma xenografts expressed the receptors for androgens, estrogens, and progesterone, their growth rate was not affected by either castration or sex steroid hormone supplementation. Cisplatin, oxaliplatin, vitamin D analogue EB1089, and Iressa had no effects on the growth rate in SCID mice. Although 5-fluorouracil exerted mild growth inhibition of these xenografts, i.p. delivery of 2-chloroethyl-3-sarcosinamide-1-nitrosourea (SarCNU) or doxorubicin resulted in a significant growth inhibition. Doxorubicin-induced growth suppression was associated with elevation of p53 and p21(Cip1/Waf1). In addition to up-regulation of p53 and p21(Cip1/Waf1), SarCNU also increased the levels of phosphorylated cdc-2 at Tyr15. CONCLUSION: Hepatocellular carcinoma xenografts are powerful tools for screening drugs and SarCNU may be useful in the treatment of this fatal disease.

Quercetin-induced growth inhibition and cell death in nasopharyngeal carcinoma cells are associated with increase in Bad and hypophosphorylated retinoblastoma expressions.

Nasopharyngeal carcinoma is a common cancer in South-East Asia, especially among people of Chinese origin. In this report, we investigate the effects of quercetin on the growth of wild-type and mutant p53 nasopharyngeal carcinoma cell lines, HK1 and CNE2 respectively. The wild-type p53 HK1 was more susceptible to growth inhibition by quercetin than the mutant p53 CNE2. The ID50 values for HK1 and CNE2 were 35.0 and 54.5 microM respectively. Cell growth arrest was initiated by the up-regulation of retinoblastoma gene expression, resulting in cell cycle arrest in either the G2/M or G0/G1 phase at 14.8 and 52.1 microM quercetin respectively regardless of the p53 status. Flow cytometry experiments revealed that quercetin-induced apoptosis during the first 24 h followed by necrosis in both HK1 and CNE2. Western blot experiments confirmed that cytotoxic killing of HK1 and CNE2 by quercetin was mediated by the up-regulation of pro-apoptotic protein Bad, caspase-3 and -7, resulting in cell death by apoptosis. Our study demonstrates that quercetin inhibits cell growth of nasopharyngeal carcinoma cell lines HK1 and CNE2 by inhibiting cell cycle progression to S phase. Quercetin is also able to induce apoptosis and necrosis in these cells regardless of the p53 status.