Pleurovenous Shunt Placement for the Management of Nonmalignant Pleural Effusion.

Therapeutic thoracentesis is a first-line therapy in the management of patients with medically refractory, nonmalignant pleural effusion. However, when required in short intervals, serial thoracenteses can lead to increased procedure-related complications and negatively impact quality of life. Alternative treatment options vary depending on the etiology of fluid accumulation. Hepatic hydrothorax secondary to cirrhosis is a common cause of medically refractory pleural effusion encountered by interventional radiologists. In select patients in whom surgical pleurodesis, transjugular intrahepatic portosystemic shunt placement, and/or tunneled pleural catheter placement cannot be performed or provide inadequate relief, implantation of a pleurovenous (Denver) shunt may assist in palliation. The Denver shunt system allows decompression of pleural fluid into the central venous circulation by utilizing unidirectional valves and a manually operated subcutaneous pump. Though limited reports have described favorable technical and clinical success, more research is required to determine the safety and efficacy of this procedure. This article discusses pleurovenous shunt placement, postprocedure shunt evaluation, and potential associated complications.

Pediatric Orthopaedic Consults From Chiropractic Care.

Alternative medicine in pediatrics is expanding, with chiropractic now a common choice for families seeking alternative medical care. Currently, there is sparse information in the literature exploring the role of chiropractic in orthopaedic pathology. The objective of this case series is to present pediatric patients who received treatment from chiropractors and orthopaedic physicians as well as to review the respective existing research. Data collected included chiropractic diagnosis, orthopaedic diagnosis, imaging studies, treatments, and complications. Twenty-three patients were studied. Scoliosis, Legg-Calvé-Perthes disease, developmental dysplasia of the hip, cerebral palsy, skeletal dysplasia, and slipped capital femoral epiphysis were diagnoses included. Children had multiple sessions of chiropractic for management of these conditions. The parents' perception for chiropractic was positive in every case. Delayed referral, misdiagnosis, adverse events from manipulative therapy, and ineffective treatments were observed in the present study. More research is indicated to validate chiropractic in children with orthopaedic pathology. (Journal of Surgical Orthopaedic Advances 27(1):58-63, 2018).

Acid ceramidase is upregulated in AML and represents a novel therapeutic target.

There is an urgent unmet need for new therapeutics in acute myeloid leukemia (AML) as standard therapy has not changed in the past three decades and outcome remains poor for most patients. Sphingolipid dysregulation through decreased ceramide levels and elevated sphingosine 1-phosphate (S1P) promotes cancer cell growth and survival. Acid ceramidase (AC) catalyzes ceramide breakdown to sphingosine, the precursor for S1P. We report for the first time that AC is required for AML blast survival. Transcriptome analysis and enzymatic assay show that primary AML cells have high levels of AC expression and activity. Treatment of patient samples and cell lines with AC inhibitor LCL204 reduced viability and induced apoptosis. AC overexpression increased the expression of anti-apoptotic Mcl-1, significantly increased S1P and decreased ceramide. Conversely, LCL204 induced ceramide accumulation and decreased Mcl-1 through post-translational mechanisms. LCL204 treatment significantly increased overall survival of C57BL/6 mice engrafted with leukemic C1498 cells and significantly decreased leukemic burden in NSG mice engrafted with primary human AML cells. Collectively, these studies demonstrate that AC plays a critical role in AML survival through regulation of both sphingolipid levels and Mcl-1. We propose that AC warrants further exploration as a novel therapeutic target in AML.

Discovery of somatic STAT5b mutations in large granular lymphocytic leukemia.

Large granular lymphocytic (LGL) leukemia is characterized by clonal expansion of cytotoxic T cells or natural killer cells. Recently, somatic mutations in the signal transducer and activator of transcription 3 (STAT3) gene were discovered in 28% to 40% of LGL leukemia patients. By exome and transcriptome sequencing of 2 STAT3 mutation-negative LGL leukemia patients, we identified a recurrent, somatic missense mutation (Y665F) in the Src-like homology 2 domain of the STAT5b gene. Targeted amplicon sequencing of 211 LGL leukemia patients revealed 2 additional patients with STAT5b mutations (N642H), resulting in a total frequency of 2% (4 of 211) of STAT5b mutations across all patients. The Y665F and N642H mutant constructs increased the transcriptional activity of STAT5 and tyrosine (Y694) phosphorylation, which was also observed in patient samples. The clinical course of the disease in patients with the N642H mutation was aggressive and fatal, clearly different from typical LGL leukemia with a relatively favorable outcome. This is the first time somatic STAT5 mutations are discovered in human cancer and further emphasizes the role of STAT family genes in the pathogenesis of LGL leukemia.

Discovery of marinopyrrole A (maritoclax) as a selective Mcl-1 antagonist that overcomes ABT-737 resistance by binding to and targeting Mcl-1 for proteasomal degradation.

The anti-apoptotic Bcl-2 family of proteins, including Bcl-2, Bcl-X(L) and Mcl-1, are well-validated drug targets for cancer treatment. Several small molecules have been designed to interfere with Bcl-2 and its fellow pro-survival family members. While ABT-737 and its orally active analog ABT-263 are the most potent and specific inhibitors to date that bind Bcl-2 and Bcl-X(L) with high affinity but have a much lower affinity for Mcl-1, they are not very effective as single agents in certain cancer types because of elevated levels of Mcl-1. Accordingly, compounds that specifically target Mcl-1 may overcome this resistance. In this study, we identified and characterized the natural product marinopyrrole A as a novel Mcl-1-specific inhibitor and named it maritoclax. We found that maritoclax binds to Mcl-1, but not Bcl-X(L), and is able to disrupt the interaction between Bim and Mcl-1. Moreover, maritoclax induces Mcl-1 degradation via the proteasome system, which is associated with the pro-apoptotic activity of maritoclax. Importantly, maritoclax selectively kills Mcl-1-dependent, but not Bcl-2- or Bcl-X(L)-dependent, leukemia cells and markedly enhances the efficacy of ABT-737 against hematologic malignancies, including K562, Raji, and multidrug-resistant HL60/VCR, by ∼60- to 2000-fold at 1-2 µM. Taken together, these results suggest that maritoclax represents a new class of Mcl-1 inhibitors, which antagonizes Mcl-1 and overcomes ABT-737 resistance by targeting Mcl-1 for degradation.