The Emerging Relevance of the Cysteine Protease Cathepsin S in Disease

Cathepsin S is a lysosomal cysteine protease that has been shown to play a key role in MHC class II antigen presentation. Consequently, it has been extensively evaluated as a therapeutic target in autoimmune diseases, such as rheumatoid arthritis and psoriasis. Additionally, clinical and mechanistic evidence is emerging, revealing its inappropriate expression and secretion in a wide range of disease states including atherosclerosis and tumourigenesis. This review covers the known role and consequences of cathepsin S activity in these pathological disorders, highlighting various studies that have demonstrated its utility as a therapeutic target. This review also examines challenges that exist towards the development of agents that specifically target this protease and discusses the studies to date that have applied cathepsin S inhibitors in disease models.     

3D left ventricular extracellular volume fraction by low-radiation dose cardiac CT: Assessment of interstitial myocardial fibrosis

BackgroundMyocardial fibrosis leads to impaired cardiac function and events. Extracellular volume fraction (ECV) assessed with an iodinated contrast agent and measured by cardiac CT may be a useful noninvasive marker of fibrosis.ObjectiveThe purpose of this study was to develop and evaluate a 3-dimensional (3D) ECV calculation toolkit (ECVTK) for ECV determination by cardiac CT.MethodsTwenty-four subjects (10 systolic heart failure, age, 60 ± 17 years; 5 diastolic failure, age 56 ± 20 years; 9 matched healthy subjects, age 59 ± 7 years) were evaluated. Cardiac CT examinations were done on a 320-multidetector CT scanner before and after 130 mL of iopamidol (Isovue-370; Bracco Diagnostics, Plainsboro, NJ, USA) was administered. A calcium score type sequence was performed before and 7 minutes after contrast with single gantry rotation during 1 breath hold and single cardiac phase acquisition. ECV was calculated as (ΔHU_myocardium/ΔHU_blood) × (1 ? Hct) where Hct is the hematocrit, and ΔHU is the change in Hounsfield unit attenuation = HU_{after iodine} ? HU_{before iodine}. Cardiac magnetic resonance imaging was performed to assess myocardial structure and function.ResultsMean 3D ECV values were significantly higher in the subjects with systolic heart failure than in healthy subjects and subjects with diastolic heart failure (mean, 41% ± 6%, 33% ± 2%, and 35% ± 5%, respectively; P = 0.02). Interobserver and intraobserver agreements were excellent for myocardial, blood pool, and ECV (intraclass correlation coefficient, >0.90 for all). Higher 3D ECV by cardiac CT was associated with reduced systolic circumferential strain, greater end-diastolic and -systolic volumes, and lower ejection fraction (r = 0.70, r = 0.60, r = 0.73, and r = ?0.68, respectively; all P < 0.001).Conclusion3D ECV by cardiac CT can be performed with ECVTK. We demonstrated increased ECV in subjects with systolic heart failure compared with healthy subjects. Cardiac CT results also showed good correlation with important functional heart biomarkers, suggesting the potential for myocardial tissue characterization with the use of 3D ECV by cardiac CT. This trial is registered at www.ClinicalTrials.gov as NCT01160471.     

Asperger syndrome and “non-verbal learning problems” in a longitudinal perspective: Neuropsychological and social adaptive outcome in early adult life

Co-existence of Asperger syndrome (AS) and non-verbal learning disability (NLD) has been proposed based on the observation that people with AS tend to have significantly higher verbal than performance IQ (VIQ>PIQ by ≥15 points), one of the core features of NLD. In the present study we examined neuropsychological and social adaptive profiles with “non-verbal learning problems” associated with NLD in a group of individuals with AS followed from childhood into early adult life. The group was divided into three subgroups: (i) persistent NLD (P-NLD), i.e. NLD (VIQ>PIQ) both in childhood and early adulthood occasions, (ii) childhood NLD (CO-NLD), i.e. NLD (VIQ>PIQ) only at original diagnosis, or (iii) No NLD (VIQ>PIQ) ever (NO-NLD). All three subgroups were followed prospectively from childhood into adolescence and young adult life. One in four to one in five of the whole group of males with AS had P-NLD. The P-NLD subgroup had poorer neuropsychological outcome in early adult life than did those with CO-NLD and those with NO-NLD. There were no unequivocal markers in early childhood that predicted subgroup status in early adult life, but early motor delay and a history of early speech-language problems tended to be associated with P-NLD.     

Metabolism of [U‐13C]glucose in human brain tumors in vivo

Glioblastomas and brain metastases demonstrate avid uptake of 2‐[¹⁸F]fluoro‐2‐deoxyglucose by positron emission tomography and display perturbations of intracellular metabolite pools by ¹H MRS. These observations suggest that metabolic reprogramming contributes to brain tumor growth in vivo. The Warburg effect, excess metabolism of glucose to lactate in the presence of oxygen, is a hallmark of cancer cells in culture. 2‐[¹⁸F]Fluoro‐2‐deoxyglucose‐positive tumors are assumed to metabolize glucose in a similar manner, with high rates of lactate formation relative to mitochondrial glucose oxidation, but few studies have specifically examined the metabolic fates of glucose in vivo. In particular, the capacity of human brain cancers to oxidize glucose in the tricarboxylic acid cycle is unknown. Here, we studied the metabolism of human brain tumors in situ. [U‐¹³ C]Glucose (uniformly labeled glucose, i.e. d ‐glucose labeled with ¹³ C in all six carbons) was infused during surgical resection, and tumor samples were subsequently subjected to ¹³C NMR spectroscopy. The analysis of tumor metabolites revealed lactate production, as expected. We also determined that pyruvate dehydrogenase, turnover of the tricarboxylic acid cycle, anaplerosis and de novo glutamine and glycine synthesis contributed significantly to the ultimate disposition of glucose carbon. Surprisingly, less than 50% of the acetyl‐coenzyme A pool was derived from blood‐borne glucose, suggesting that additional substrates contribute to tumor bioenergetics. This study illustrates a convenient approach that capitalizes on the high information content of ¹³C NMR spectroscopy and enables the analysis of intermediary metabolism in diverse cancers growing in their native microenvironment. Copyright © 2012 John Wiley & Sons, Ltd.     

Association between hospital volume and network membership and an analgesia, sedation and delirium order set quality score: a cohort study

ABSTRACT: INTRODUCTION: Protocols for the delivery of analgesia, sedation and delirium care of the critically ill, mechanically ventilated patient have been shown to improve outcomes but are not uniformly used. The extent to which elements of analgesia, sedation and delirium guidelines are incorporated into order sets at hospitals across a geographic area is not known. We hypothesized that both greater hospital volume and membership in a hospital network are associated with greater adherence of order sets to sedation guidelines. METHODS: Sedation order sets from all nonfederal hospitals without pediatric designation in Washington State that provided ongoing care to mechanically ventilated patients were collected and their content systematically abstracted. Hospital data were collected from Washington State sources and interviews with ICU leadership in each hospital. An expert-validated score of order set quality was created based on the 2002 four-society guidelines. Clustered multivariable linear regression was used to assess the relationship between hospital characteristics and the order set quality score. RESULTS: Fifty-one Washington State hospitals met the inclusion criteria and all provided order sets. Based on expert consensus, 21 elements were included in the analgesia, sedation and delirium order set quality score. Each element was equally weighted and contributed one point to the score. Hospital order set quality scores ranged from 0 to 19 (median = 8, interquartile range 6 to 14). In multivariable analysis, a greater number of acute care days (P = 0.01) and membership in a larger hospital network (P = 0.01) were independently associated with a greater quality score. CONCLUSIONS: Hospital volume and membership in a larger hospital network were independently associated with a higher quality score for ICU analgesia, sedation and delirium order sets. Further research is needed to determine whether greater order-set quality is associated with improved outcomes in the critically ill. The development of critical care networks might be one strategy to improve order set quality scores.     

The relationship between serum sodium and intracranial pressure when using hypertonic saline to target mild hypernatremia in patients with head trauma

During sepsis, the liver plays a key role. It is implicated in the host response, participating in the clearance of the infectious agents/products. Sepsis also induces liver damage through hemodynamic alterations or through direct or indirect assault on the hepatocytes or through both. Accordingly, liver dysfunction induced by sepsis is recognized as one of the components that contribute to the severity of the disease. Nevertheless, the incidence of liver dysfunction remains imprecise, probably because current diagnostic tools are lacking, notably those that can detect the early liver insult. In this review, we discuss the epidemiology, diagnostic tools, and impact on outcome as well as the pathophysiological aspects, including the cellular events and clinical picture leading to liver dysfunction. Finally, therapeutic considerations with regard to the weakness of the pertinent specific approach are examined.