Sprifermin (rhFGF18) versus vehicle induces a biphasic process of extracellular matrix remodeling in human knee OA articular cartilage ex vivo.

Sprifermin, recombinant human fibroblast growth factor 18 (rhFGF18), induces cartilage regeneration in knees of patients with osteoarthritis (OA). We hypothesized that a temporal multiphasic process of extracellular matrix (ECM) degradation and formation underlie this effect. We aimed to characterize the temporal ECM remodeling of human knee OA articular cartilage in response to sprifermin treatment. Articular cartilage explants from patients with knee OA (npatients = 14) were cultured for 70 days, with permanent exposure to sprifermin (900, 450, 225 ng/mL), FGF18 (450 ng/mL), insulin-like growth factor-1 (100 ng/mL, positive control) or vehicle (nreplicates/treatment/patient = 2). Metabolic activity (AlamarBlue) and biomarkers of type IIB collagen (PIIBNP) formation (Pro-C2 enzyme-linked immunosorbent assay [ELISA]) and aggrecanase-mediated aggrecan neo-epitope NITEGE (AGNx1 ELISA) were quantified once a week. At end of culture (day 70), gene expression (quantitative reverse transcription polymerase chain reaction) and proteoglycan content (Safranin O/Fast green staining) were quantified. The cartilage had continuously increased metabolic activity, when treated with sprifermin/FGF18 compared to vehicle. During days 7-28 PIIBNP was decreased and NITEGE was increased, and during days 35-70 PIIBNP was increased. At end of culture, the cartilage had sustained proteoglycan content and relative expression of ACAN < COL2A1 < SOX9 < COL1A1, indicating that functional chondrocytes remained in the explants. Sprifermin induces a temporal biphasic cartilage remodeling in human knee OA articular cartilage explants, with early-phase increased aggrecanase activity and late-phase increased type II collagen formation.

Sprifermin (rhFGF18) enables proliferation of chondrocytes producing a hyaline cartilage matrix.

OBJECTIVE: Fibroblast growth factor (FGF) 18 has been shown to increase cartilage volume when injected intra-articularly in animal models of osteoarthritis (OA) and in patients with knee OA (during clinical development of the recombinant human FGF18, sprifermin). However, the exact nature of this effect is still unknown. In this study, we aimed to investigate the effects of sprifermin at the cellular level. DESIGN: A combination of different chondrocyte culture systems was used and the effects of sprifermin on proliferation, the phenotype and matrix production were evaluated. The involvement of MAPKs in sprifermin signalling was also studied. RESULTS: In monolayer, we observed that sprifermin promoted a round cell morphology and stimulated both cellular proliferation and Sox9 expression while strongly decreasing type I collagen expression. In 3D culture, sprifermin increased the number of matrix-producing chondrocytes, improved the type II:I collagen ratio and enabled human OA chondrocytes to produce a hyaline extracellular matrix (ECM). Furthermore, we found that sprifermin displayed a 'hit and run' mode of action, with intermittent exposure required for the compound to fully exert its anabolic effect. Finally, sprifermin appeared to signal through activation of ERK. CONCLUSIONS: Our results indicate that intermittent exposure to sprifermin leads to expansion of hyaline cartilage-producing chondrocytes. These in vitro findings are consistent with the increased cartilage volume observed in the knees of OA patients after intra-articular injection with sprifermin in clinical studies.

Spotting and designing promiscuous ligands for drug discovery.

The promiscuous binding behavior of bioactive compounds forms a mechanistic basis for understanding polypharmacological drug action. We present the development and prospective application of a computational tool for identifying potential promiscuous drug-like ligands. In combination with computational target prediction methods, the approach provides a working concept for rationally designing such molecular structures. We could confirm the multi-target binding of a de novo generated compound in a proof-of-concept study relying on the new method.

Osteoarthritis year in review 2015: soluble biomarkers and the BIPED criteria.

OBJECTIVE: To review and summarize biomarker data published from April 2014 to May 2015 to provide insight to the ongoing work in the field of osteoarthritis (OA). Furthermore, to summarize the BIPED criteria and set it in context of the medical needs of 2015. METHODS: PubMed was used as searching machine: Time period 2014/04/01-2015/05/01, MeSH term [Biomarker] AND [Osteoarthritis], Language; English, Full text available. Reviews were excluded. Only papers describing protein based biomarkers measured in human body fluids from OA patients were included. RESULTS: Biomarkers of joint tissue turnover, cytokines, chemokines and peptide arrays were measured in different cohorts and studies. Amongst those were previously tested biomarkers such as osteocalcin, Carboxy-terminal cross-linked fragment of type II collagen (CTX-II) and cartilage oligomeric matrix protein (COMP). A majority of the biomarker were classified as I, B or B biomarkers according to the BIPED criteria. Work is continuing on testing biomarkers in OA. There is still a huge, unmet medical need to identify, test, validate and qualify novel and well-known biomarkers. A pre-requisite for this is better characterization and classification of biomarkers to their needs, which may not be reached before higher understanding of OA phenotypes has been gained. In addition, we provide some references to some recent guidelines from Food and Drug Administration (FDA) and European Medicines Agency (EMA) on qualification and usage of biomarkers for drug development and personalized medicine, which may provide value to the field.

Multi-objective active machine learning rapidly improves structure-activity models and reveals new protein-protein interaction inhibitors.

Active machine learning puts artificial intelligence in charge of a sequential, feedback-driven discovery process. We present the application of a multi-objective active learning scheme for identifying small molecules that inhibit the protein-protein interaction between the anti-cancer target CXC chemokine receptor 4 (CXCR4) and its endogenous ligand CXCL-12 (SDF-1). Experimental design by active learning was used to retrieve informative active compounds that continuously improved the adaptive structure-activity model. The balanced character of the compound selection function rapidly delivered new molecular structures with the desired inhibitory activity and at the same time allowed us to focus on informative compounds for model adjustment. The results of our study validate active learning for prospective ligand finding by adaptive, focused screening of large compound repositories and virtual compound libraries.

Stroke: who's counting what?

INTRODUCTION: Patients with stroke are often selected for epidemiological reporting and research using ICD-9-CM (ICD-9) diagnostic codes. This study addresses the accuracy of these codes in identifying patients with stroke. METHODS: A sample of 279 patients with new stroke and 392 non-stroke (no evidence of new stroke) patients were identified by medical record review from 11 Veterans Affairs Medical Centers. Administrative records containing ICD-9-CM diagnoses were matched with this sample. Coding sensitivity and specificity were determined using individual ICD-9 codes and two coding algorithms. RESULTS: Significant variation was found in the accuracy of cerebrovascular ICD-9-CM codes in identifying patients diagnosed with stroke. Two coding algorithms were identified with the following performance statistics based on the sampled populations: 1) 91-percent sensitivity, 40-percent specificity; and 2) 54-percent sensitivity, 87-percent specificity. DISCUSSION/CONCLUSIONS: Variability in identifying patients with stroke using ICD-9 codes has been reported in the literature and confirmed. Two coding algorithms for maximizing sensitivity or specificity are proposed. Caution is urged when using ICD-9-coded administrative data to identify patients with stroke.

Stroke care: a method for measuring compliance with AHCPR guidelines.

The purpose of this article is to describe a method for converting practice guidelines to measurement criteria. To evaluate the processes of care received by patients with stroke at 11 Veteran's Administration hospital sites, we developed a measurement system based on Agency for Health Care Policy and Research (AHCPR) Post-Stroke Rehabilitation Clinical Practice Guidelines. Guideline recommendations were used as the framework for identifying important dimensions of care, and for developing chart abstraction instruments for both the acute and postacute settings. Using a modified Delphi technique to solicit opinions from an expert panel, a method was developed for aggregation of item-level chart abstraction components to overall guideline compliance scores. The measurement system was shown to have good-to-excellent intrarater and interrater reliability at the item, dimension, and overall compliance score levels. Abstraction of a sample of 100 medical records demonstrated the ability of the instruments to detect variability in processes of post-stroke care. This study provides the foundation for future research, which will evaluate associations between processes of post-stroke care, as measured by this medical chart abstraction system, and patient outcomes. (All abstraction instruments, criteria, and scoring algorithms described in this article are available for download at http://www2.kumc.edu/coa.)

Differences in rehabilitation services and outcomes among stroke patients cared for in veterans hospitals.

OBJECTIVE: To examine the relationship of services for post-acute care (PAC) to stroke patient outcomes. DATA SOURCES/STUDY SETTING: Veterans Health Administration (VHA) hospitals from two facility-level surveys and extant data files. STUDY DESIGN: Cross-sectional study of veterans hospitalized with acute stroke during the period June 1995 through May 1996 in one of 182 geographically distinct locations within the VHA. Study variables included (1) a typological classification of hospitals according to the level of PAC; (2) a taxonomy of rehabilitation characteristics, including personnel, physical facilities, coordination of care, and hospital characteristics; and (3) patient outcomes (discharge destination, length of stay). DATA COLLECTION/EXTRACTION METHODS: Data were collected from two mailed surveys and extant data files. Rehabilitation variables were identified for the study in conjunction with a panel of expert rehabilitation researchers and clinicians, using an a priori model for measuring rehabilitation characteristics. Two sets of variables were derived to categorize these rehabilitation characteristics: (1) a rehabilitation typology, classifying the VA hospitals according to the continuum of PAC settings in the facility, and (2) a rehabilitation taxonomy that used an empirical approach to derive a list of key rehabilitation characteristics. PRINCIPAL FINDINGS: Twenty-seven percent of veterans with acute stroke were cared for in VA hospitals with neither a geriatric nor a rehabilitation unit, and 50 percent were cared for in hospitals without a rehabilitation unit. Hospitals with rehabilitation units had the greatest sophistication, and those with geriatric units had intermediate sophistication in rehabilitation organization and resources. Statistically significant differences were found in outcomes for stroke patients cared for in hospitals classified according to the continuum of post-acute care on site. Exploratory multivariable analyses revealed independent associations between stroke patient outcomes and (1) staffing ratios for nurses and physicians, (2) the diversity of physician and rehabilitation staff, (3) presence of a simulated home environment, and (4) the total number of care settings on site. CONCLUSIONS: The PAC continuum defines an important hierarchy of stroke rehabilitation services.

The structure and structural effects of VA rehabilitation bedservice care for stroke.

The purpose of this study was to: 1) examine the variation in organizational structure within rehabilitation bed-service units (RBU) in the Veterans Health Administration (VHA), and 2) evaluate the effects of RBU and parent hospital structure on stroke rehabilitation outcomes. Two VHA-wide surveys of acute and rehabilitation services for stroke were linked with 2 y of VHA rehabilitation outcomes for stroke patients. A random effects mixed model was used to adjust for patient level covariates, control for unique site effects, and test for facility level structural effects. After adjusting for patient covariates, four structural variables were associated with length of stay or patient functional gain. These results indicate that rehabilitation structure is important to rehabilitation outcome. The individual variables identified in this study, namely, diverse multidisciplinary staff, expert physician leadership, staff participation in team care, and richer rehabilitation equipment resources, may represent the distinct aspects of a successful, comprehensive rehabilitation unit.

Stroke rehabilitation outcome variation in Veterans Affairs rehabilitation units: accounting for case-mix.

OBJECTIVE: To assess variation in stroke outcomes and create a case-mix adjustment model for stroke rehabilitation in Veterans Affairs Medical Centers. DESIGN: Observational SETTING AND PATIENTS: Within Veteran's Health Administration hospitals, there are 63 acute rehabilitation bedservice units that care for approximately 2,000 stroke patients annually. MAIN OUTCOME MEASURES: Functional gain in FIM points, length of stay (LOS), LOS efficiency (FIM gain/LOS). RESULTS: Significant variation in average patient functional gain, LOS, and LOS efficiency was observed among the 37 highest-volume rehabilitation units. Using analysis of covariance, a model was developed that adjusted functional gain and LOS (logged LOS) unit means using 10 potential covariates identified in a literature review and in pilot studies. Four and six covariates, respectively, were retained in the final models for FIM gain and LOS. The R2 for FIM gain and LOS accounted for by rehabilitation unit alone increased from .07 to .31 (FIM gain) and from .13 to .34 (logLOS) with the addition of the significant covariates to each model. CONCLUSIONS: As much as 24% of the variation in two important stroke rehabilitation outcomes is attributable to largely immutable patient and system characteristics (eg, patient function on admission, age, days since stroke onset, year of discharge, marital status, and referral source). Hence, controlling for case-mix is critical for accurate comparison of unit outcomes. Further, the variation in LOS efficiency between VA rehabilitation units suggests a large potential for cost and resource utilization savings system-wide.

A comparison of in-house and regionalized computerized tomography scanning: clinical impact and cost.

Over a two-year interval, computerized tomography (CT) scans at an urban, 400-bed Department of Veterans Affairs medical center (VAMC) were obtained in three ways. First, an in-house low-efficiency machine was used. Then, scans were done at another area hospital, in effect duplicating some aspects of regionalizing services. Finally, a high-efficiency in-house machine was used. Clinical outcomes and costs of diagnosing 181 bronchogenic cancer patients were compared across the three time periods to identify any differences associated with regionalization of CT services. Patient groups were homogeneous with respect to sociodemographic characteristics, clinical presentation, and severity of disease. The first part of the analysis investigated whether the site of CT scanning affected clinical outcomes. Diagnostic procedures, surgical results, mortality, and length of stay were compared using one-way analysis of variance. Significant differences were found only for conventional tomography and CT utilization rates. While conventional tomography declined across the periods, CT utilization increased, exceeding national trends. The second part of the analysis examined the costs of CT scanning. During the regionalized period, the hospital paid a fixed fee of $519 per scan. Estimated costs of in-house scans were $285 in the low-efficiency and $141 in the high-efficiency periods. Charge-based payments made to the external facility and differences in the volumes of patients scanned internally account for the cost differences. The analysis showed that while regionalized CT scanning did not compromise the quality of care for these VA patients, it was more costly. Results suggest that VA hospital administrators should carefully consider ownership and payment arrangements when comparing regionalized and in-house provision of services.

Observer reliability in CT and MRI of the abdomen/pelvis.

The purpose of this research was to evaluate two sources of error in the performance of computerized tomography (CT) and magnetic resonance imaging (MRI) of the abdomen/pelvis. The sources of error assessed were inter- and intra-observer reliability. Thirty abdomen/pelvis CT scans were randomly selected from each of three hospitals (university, VA, military) with different CT scanners. Two radiologists were recruited from each site to be CT observers. Forty-five abdomen/pelvis MRI scans were randomly selected from two institutions with different MRI scanners. Four observers were recruited to read the MRI scans. All scans were read blind without clinical information or patient identification. Overall inter-observer and intra-observer diagnostic agreement was significantly higher for MRI compared to CT. Inter-observer diagnostic agreement rates were also significantly higher for MRI when the etiologies of neoplastic vascular and metabolic/toxic were assigned. Observer experience in CT (range: 5-9 yr) or MRI (range: 2-4 yr) was not statistically associated with improved diagnostic agreement. This research addresses many of the criticisms of the MRI literature and compares MRI favorably to CT.

Naloxone, tardive dyskinesia, and endogenous beta-endorphin.

The subjects were 13 psychiatric inpatients with tardive dyskinesia. Each subject participated in two sessions. Either naloxone (10 mg) or placebo was administered intravenously during each session. In a subset of subjects (n = 7), blood samples for beta-endorphin were drawn before and at 30 and 60 minutes after the injection. The Abnormal Involuntary Movement Scale was administered before and at 10, 20, 40, 60, 120, and 360 minutes after the injection. Double-blind procedures were maintained throughout the experiment. Neither naloxone nor placebo had any appreciable effect on the involuntary movements. Naloxone elicited a significant increase in the plasma beta-endorphin.

An endogenous ligand to the benzodiazepine receptor: preliminary evaluation of its bioactivity.

Chromatographic separation of aqueous brain extracts yields a peptide containing fraction which competitively inhibits 3H-diazepam binding to its receptor. An intracerebral-ventricular injection of this isolated fraction results in altered responses in pharmacological and behavioral tests which are similar to those observed when diazepam is administered in the same fashion. The most pronounced effect was obtained in the conflict test. Changes observed in other tests, such as blocking pentylenetetrazole convulsions, altering motility or reducing hyperthermia, were also consistent with the actions of diazepam. At the dose used, neither diazepam nor the brain extract altered muscular co-ordination in two ataxia evaluations. Thus, the animals' performance in the other paradigms would not be adversely influenced by immobilization side-effects. The results reported here support the notion that an endogenous factor does exist in brain which can act like the benzodiazepine drugs when tested for bioactivity in animal studies.