Relative effects of forced vital capacity and ALSFRS-R on survival in ALS.

INTRODUCTION/AIM: Amyotrophic lateral sclerosis (ALS) is a degenerative neuromuscular disease with marked clinical heterogeneity. This heterogeneity can be partly captured by clinical measures, such as the forced vital capacity (FVC) and ALS Functional Rating Scale-Revised (ALSFRS-R). We aimed to further characterize the performance of these clinical measures, including their independence and additivity, in predicting mortality. METHODS: We leveraged the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT ALS) database, which includes data from 23 clinical trials (n = 2050). The primary exposures were baseline FVC and ALSFRS-R. The primary outcome was 1-y mortality. We performed correlation analyses, survival analyses and assessed classification performance using receiver operator characteristic (ROC) curves. RESULTS: FVC and ALSFRS-R were weakly correlated (r = 0.31, p < .001). A 1-SD increase in FVC (hazard ratio [HR]: 0.66; 95% confidence interval [CI]: 0.59-0.74) and ALSFRS-R (HR: 0.75; 95% CI: 0.68-0.82) were associated with reduced risk of 1-y mortality. ROC analyses showed optimal predictive cutoffs at 80% for FVC (area under the curve [AUC]: 0.69) and 38 for ALSFRS-R (AUC: 0.67). After stratifying patients based on these cutoffs, we found a marked reduction (HR: 0.25; 95% CI: 0.19-0.33) in incident mortality for patients in the high FVC and high ALSFRS-R group relative to the low FVC and low ALSFRS-R group. DISCUSSION: ALSFRS-R and FVC are comparable predictors of survival that are only weakly correlated. When considered together, they synergistically predict survival. As such, consideration of both measures should be a routine part of prognostication in care of patients with ALS.

Primary Pulmonary Chondrosarcoma: A Case Report and Literature Review.

Chondrosarcomas are tumors consisting of osseous or cartilaginous stroma. They are not an uncommon pathology; however, primary pulmonary chondrosarcomas arising in lung parenchyma are extremely rare, with few cases published in literature. Herein, we present a case with biopsy-proven primary pulmonary chondrosarcoma after exclusion of primary origin elsewhere. In the case presented in this report, we demonstrate the clinical presentations, pulmonary function tests, and the radiological findings of this rare tumor in a young male patient. Further, we present a brief review of existing literature for patients with similar pathology.

Skeletal Response to Soluble Activin Receptor Type IIB in Mouse Models of Osteogenesis Imperfecta.

Osteogenesis imperfecta (OI) is a heritable connective tissue disorder primarily due to mutations in the type I collagen genes (COL1A1 and COL1A2), leading to compromised biomechanical integrity in type I collagen-containing tissues such as bone. Bone is inherently mechanosensitive and thus responds and adapts to external stimuli, such as muscle mass and contractile strength, to alter its mass and shape. Myostatin, a member of the TGF-ß superfamily, signals through activin receptor type IIB to negatively regulate muscle fiber growth. Because of the positive impact of myostatin deficiency on bone mass, we utilized a soluble activin receptor type IIB-mFc (sActRIIB-mFc) fusion protein in two molecularly distinct OI mouse models (G610C and oim) and evaluated their bone properties. Wild-type (WT), +/G610C, and oim/oim mice were treated from 2 to 4 months of age with either vehicle (Tris-buffered saline) or sActRIIB-mFc (10 mg/kg). Femurs of sActRIIB-mFc-treated mice exhibited increased trabecular bone volume regardless of genotype, whereas the cortical bone microarchitecture and biomechanical strength were only improved in WT and +/G610C mice. Dynamic histomorphometric analyses suggest the improved cortical bone geometry and biomechanical integrity reflect an anabolic effect due to increased mineral apposition and bone formation rates, whereas static histomorphometric analyses supported sActRIIB-mFc treatment also having an anti-catabolic impact with decreased osteoclast number per bone surface on trabecular bone regardless of sex and genotype. Together, our data suggest that sActRIIB-mFc may provide a new therapeutic direction to improve both bone and muscle properties in OI. © 2018 American Society for Bone and Mineral Research.

Soluble activin receptor type IIB decoy receptor differentially impacts murine osteogenesis imperfecta muscle function.

INTRODUCTION: Osteogenesis imperfecta (OI) is characterized by skeletal fragility and muscle weakness. In this study we investigated the effects of soluble activin type IIB receptor (sActRIIB-mFc) on muscle mass and function in 2 distinct mouse models of OI: osteogenesis imperfecta murine (oim) and +/G610C. METHODS: Wild-type (WT), +/G610C, and oim/oim mice were treated from 2 to 4 months of age with Tris-buffered saline (vehicle) or sActRIIB-mFc and their hindlimb muscles evaluated for mass, morphology, and contractile function. RESULTS: sActRIIB-mFc-treated WT, +/G610C, and oim/oim mice had increased hindlimb muscle weights and myofiber cross-sectional area compared with vehicle-treated counterparts. sActRIIB-mFc-treated oim/oim mice also exhibited increased contractile function relative to vehicle-treated counterparts. DISCUSSION: Blocking endogenous ActRIIB was effective at increasing muscle size in mouse models of OI, and increasing contractile function in oim/oim mice. ActRIIB inhibitors may provide a potential mutation-specific therapeutic option for compromised muscle function in OI. Muscle Nerve 57: 294-304, 2018.

Decreasing maternal myostatin programs adult offspring bone strength in a mouse model of osteogenesis imperfecta.

During fetal development, the uterine environment can have effects on offspring bone architecture and integrity that persist into adulthood; however, the biochemical and molecular mechanisms remain unknown. Myostatin is a negative regulator of muscle mass. Parental myostatin deficiency (Mstntm1Sjl/+) increases muscle mass in wild-type offspring, suggesting an intrauterine programming effect. Here, we hypothesized that Mstntm1Sjl/+ dams would also confer increased bone strength. In wild-type offspring, maternal myostatin deficiency altered fetal growth and calvarial collagen content of newborn mice and conferred a lasting impact on bone geometry and biomechanical integrity of offspring at 4 mo of age, the age of peak bone mass. Second, we sought to apply maternal myostatin deficiency to a mouse model with osteogenesis imperfecta (Col1a2oim), a heritable connective tissue disorder caused by abnormalities in the structure and/or synthesis of type I collagen. Femora of male Col1a2oim/+ offspring from natural mating of Mstntm1Sjl/+ dams to Col1a2oim/+sires had a 15% increase in torsional ultimate strength, a 29% increase in tensile strength, and a 24% increase in energy to failure compared with age, sex, and genotype-matched offspring from natural mating of Col1a2oim/+ dams to Col1a2oim/+ sires. Finally, increased bone biomechanical strength of Col1a2oim/+ offspring that had been transferred into Mstntm1Sjl/+ dams as blastocysts demonstrated that the effects of maternal myostatin deficiency were conferred by the postimplantation environment. Thus, targeting the gestational environment, and specifically prenatal myostatin pathways, provides a potential therapeutic window and an approach for treating osteogenesis imperfecta.