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Background— In vitro studies suggest that phosphorylation of titin reduces myocyte/myofiber stiffness. Titin can be phosphorylated by cGMP-activated protein kinase. Intracellular cGMP production is stimulated by B-type natriuretic peptide (BNP) and degraded by phosphodiesterases, including phosphodiesterase-5A. We hypothesized that a phosphodiesterase-5A inhibitor (sildenafil) alone or in combination with BNP would increase left ventricular diastolic distensibility by phosphorylating titin. Methods and Results— Eight elderly dogs with experimental hypertension and 4 young normal dogs underwent measurement of the end-diastolic pressure-volume relationship during caval occlusion at baseline, after sildenafil, and BNP infusion. To assess diastolic distensibility independently of load/extrinsic forces, the end-diastolic volume at a common end-diastolic pressure on the sequential end-diastolic pressure-volume relationships was measured (left ventricular capacitance). In a separate group of dogs (n=7 old hypertensive and 7 young normal), serial full-thickness left ventricular biopsies were harvested from the beating heart during identical infusions to measure myofilament protein phosphorylation. Plasma cGMP increased with sildenafil and further with BNP (7.31±2.37 to 26.9±10.3 to 70.3±8.1 pmol/mL; P <0.001). Left ventricular diastolic capacitance increased with sildenafil and further with BNP (51.4±16.9 to 53.7±16.8 to 60.0±19.4 mL; P <0.001). Changes were similar in old hypertensive and young normal dogs. There were no effects on phosphorylation of troponin I, troponin T, phospholamban, or myosin light chain-1 or -2. Titin phosphorylation increased with sildenafil and BNP, whereas titin-based cardiomyocyte stiffness decreased. Conclusion— Short-term cGMP-enhancing treatment with sildenafil and BNP improves left ventricular diastolic distensibility in vivo, in part by phosphorylating titin.

In the modern age of advanced surgical techniques and pharmacologic management, bacterial spinal infections (SIs) can be managed (either eradicated or suppressed) in many hosts. However, the optimal management of SIs may be limited by patient comorbidities, which do not allow for surgical management, or limited by antimicrobial options due to side effects, toxicities, or emerging drug resistance. In these settings, frank and honest discussion regarding risks and benefits of treatment should be pursued, including that the SI may be a terminal illness. In this case series, we present 3 patients who had bacterial SIs whose treatments were limited by the above-mentioned factors. Furthermore, each case presented challenges regarding optimal medical management of somatic and neuropathic pain associated with the SI.

Methylphenidate is a psychostimulant originally used for the treatment of attention-deficit disorder. Methylphenidate inhibits neuronal neurotransmitter transporters involved in the uptake of dopamine and norepinephrine at the level of the synapse. Inhibition of these transmitter transporters leads to increased concentrations of dopamine and norepinephrine in the synapse, which results in increasing alertness. The stimulant effect of methylphenidate has been used for the treatment of major depression, poststroke depression, cognitive enhancement in patients with brain tumors, neurodegenerative disorders, HIV disease, fatigue, and as a treatment for delirium and sedation associated with opioid use. Other areas where methylphenidate has been evaluated include gait disorders in the elderly individuals and the treatment of apathy in dementia. Analgesic effects have been demonstrated in preclinical models but true analgesic effects remain to be proven in humans. This article reviews the current use of methylphenidate for symptom management with a critical look at the evidence base for its efficacy in the conditions described.

AbstractBackgroundBiochemical tests have been recommended as endpoints for clinical trials in primary biliary cirrhosis (PBC) because the use of liver transplantation and death as endpoints in ursodeoxycholic acid (UDCA) therapeutic trials is unfeasible. The best inclusion criteria cut‐off values and cut‐off for demonstrating treatment success have not been defined.AimOur aim was to determine the optimal biochemical values for patient inclusion and to define values for treatment success in therapeutic trials.MethodsWe performed a retrospective review of 73 patients with PBC treated with UDCA followed over 36 months. Following one year of UDCA therapy, the likelihood of developing clinical endpoints of varices, ascites, encephalopathy, death or transplantation over the ensuing two years, based on degrees of elevation of biochemical markers, was analyzed using chi‐square or Fisher's exact test.ResultsPatients with ALP≥2 X upper limit of normal (ULN) had a 2‐fold greater likelihood of developing endpoints compared to patients with lower values (23% versus 11%), (p < 0.05). Patients with bilirubin > 1 mg/dL were 4 times more likely to develop endpoints compared to those with lower values (33% versus 8%), (p = 0.02). These values help identify the patient population for adjunctive therapy trials. Patients with ALP ≤1.67 X ULN and bilirubin ≤1mg/dL demonstrated the least likelihood of reaching adverse clinical endpoints and can be used to define treatment success.ConclusionOptimal ALP and Bilirubin levels can be used as appropriate biochemical criteria for patient selection and defining treatment success in future clinical trials in patients with PBC.

Objective A study was undertaken to estimate the fraction of intracranial aneurysms that might be amenable to treatment with the pipeline embolization device (PED), a current flow diverter device, and to determine the types of aneurysms that are probably not amenable to treatment with this device. Methods A retrospective analysis of 200 consecutive intracranial aneurysms as seen on three-dimensional rotational angiography images was conducted. Based on aneurysm and parent artery morphology, four independent observers experienced in the use of the PED judged the likelihood that a given aneurysm could theoretically be treated with one or more PED using a 5-point scale: grades 1 and 2 indicated amenability to treatment with multiple devices; grade 3 indicated amenability to treatment with one device; and grades 4 and 5 indicated the aneurysm would not be amenable to treatment with the PED. Aneurysms were analyzed on the basis of anatomical factors only. Rupture status was not considered. Interobserver agreement was determined. Results 94 of 200 aneurysms (47%) were judged to be likely to be amenable to treatment with the PED; 50 cases (25%) were judged to be amenable to the use of multiple overlapping devices while, in 44 cases (22%), coverage with a single device was preferred. There was a significant relationship between the location of the aneurysm and the grade of the aneurysm (p<0.0001). Conclusion On the basis of anatomical configuration, nearly half of the aneurysms in this study were likely to be amenable to treatment with the PED.

AbstractBackgroundCholangiocarcinomas (CCAs) are highly desmoplastic neoplasms with a tumour microenvironment plentiful in myofibroblasts (MFBs).MFB‐derivedPDGF‐BBsurvival signalling is a mediator ofCCAcell resistance to apoptotic stimuli. This raises the concept that targetingPDGFR‐β, a cognate receptor ofPDGF‐BB, represents a potential strategy for the treatment of humanCCA.AimsHerein, we examine a role for inhibitingPDGFR‐β in restoringCCAcell sensitivity to apoptotic stimuliin vitroandin vivo.MethodsWe employed humanCCAsamples from 41 patients (19 intrahepatic and 22 extrahepaticCCAsamples), the humanCCAcell linesKMCH‐1 andHUCCT‐1 as well as shPDGFR‐β‐KMCH‐1 and human myofibroblasticLX‐2 cells for these studies.In vivo‐experiments were conducted using a syngeneic rat orthotopicCCAmodel.ResultsOf severalMFB‐derived growth factors profiled,PDGF‐BBandCTGFwere most abundantly expressed; however, onlyPDGF‐BBattenuated tumour necrosis factor‐related apoptosis‐inducing ligand (TRAIL) cytotoxicity. Co‐culturingCCAcells withPDGF‐BB‐secretingMFBs significantly decreasedTRAIL‐inducedCCAcell apoptosis when compared with monoculture conditions; this cytoprotective effect was abrogated in the presence of the tyrosine kinase inhibitors imatinib mesylate or linifanib, which inhibitPDGFR‐β. Consistent with these findings,MFB‐imparted cytoprotection also was abolished whenPDGFR‐β was knocked down as demonstrated in shPDGFR‐β‐KMCH‐1 cells. Finally, administration of imatinib mesylate increasedCCAcell apoptosis and reduced tumour growth in a rodentin vivo‐CCAmodel that mimics the human disease.ConclusionsTargetingPDGFR‐β sensitizesCCAcells to apoptotic stimuli and appears to be therapeuticin vivo.

Background Based on changes in core physical therapy documents and problems with the earlier version, the Physical Therapist Clinical Performance Instrument (PT CPI): Version 1997 was revised to create the PT CPI: Version 2006. Objective The purpose of this study was to validate the PT CPI: Version 2006 for use with physical therapist students as a measure of clinical performance. Design This was a combined cross-sectional and prospective study. Methods A convenience sample of physical therapist students from the United States and Canada participated in this study. The PT CPI: Version 2006 was used to collect CPI item–level data from the clinical instructor about student performance at midterm and final evaluation periods in the clinical internship. Midterm evaluation data were collected from 196 students, and final evaluation data were collected from 171 students. The students who participated in the study had a mean age of 24.8 years (SD=2.3, range=21–41). Sixty-seven percent of the participants were from programs in the United States, and 33% were from Canada. Results The PT CPI: Version 2006 demonstrated good internal consistency, and factor analysis with varimax rotation produced a 3-factor solution explaining 94% of the variance. Construct validity was supported by differences in CPI item scores between students on early compared with final clinical experiences. Validity also was supported by significant score changes from midterm to final evaluations for students on both early and final internships and by fair to moderate correlations between prior clinical experience and remaining course work. Limitations This study did not examine rater reliability. Conclusion The results support the PT CPI: Version 2006 as a valid measure of physical therapist student clinical performance.

We report the clinical presentation and laboratory findings of a 69-year-old man with fragile X-associated tremor ataxia syndrome (FXTAS), a progressive neurodegenerative disorder, who was noted to have monoclonal gammopathy of undetermined significance (MGUS), a plasma cell proliferative disorder and a precursor disease of multiple myeloma. Both MGUS and FXTAS are associated with microRNA (miRNA) dysregulation. We speculate that individuals with FXTAS may be predisposed to MGUS and further studies are warranted regarding this association.