Phenotype standardization for drug-induced kidney disease.

Drug-induced kidney disease is a frequent cause of renal dysfunction; however, there are no standards to identify and characterize the spectrum of these disorders. We convened a panel of international, adult and pediatric, nephrologists and pharmacists to develop standardized phenotypes for drug-induced kidney disease as part of the phenotype standardization project initiated by the International Serious Adverse Events Consortium. We propose four phenotypes of drug-induced kidney disease based on clinical presentation: acute kidney injury, glomerular, tubular, and nephrolithiasis, along with the primary and secondary clinical criteria to support the phenotype definition, and a time course based on the KDIGO/AKIN definitions of acute kidney injury, acute kidney disease, and chronic kidney disease. Establishing causality in drug-induced kidney disease is challenging and requires knowledge of the biological plausibility for the specific drug, mechanism of injury, time course, and assessment of competing risk factors. These phenotypes provide a consistent framework for clinicians, investigators, industry, and regulatory agencies to evaluate drug nephrotoxicity across various settings. We believe that this is the first step to recognizing drug-induced kidney disease and developing strategies to prevent and manage this condition

Inadvertent Percutaneous Endoscopic Gastrostomy Tube Placement through the Transverse Colon to the Stomach Causing Intractable Diarrhea: A Case Report

Background. Among patients with chronic disease, percutaneous endoscopic gastrostomy (PEG) tubes are a common mechanism to deliver enteral feedings to patients unable to feed by mouth. While several cases in the literature describe difficulties with and complications of the initial placement of the PEG, few studies have documented the effects of a delayed diagnosis of a misplaced tube. Methods. This case study reviews the hospitalization of an 82 year old male with an inadvertent placement of a PEG tube through the transverse colon. Photos of the placement in the stomach as well as those of the follow up colonoscopy, and a recording of the episodes of diarrhea during the hospitalization were made. Results. The records of this patient reveal complaints of gastrointestinal distress and diarrhea immediately after placement of the tube. Placement in the stomach was verified by endoscopy, with discovery of the tube only after a follow up colonoscopy. The tube remained in place after this discovery, and was removed weeks after the diarrhea was unsuccessfully treated with antibiotics. After tube removal, the patient recovered well and was sent home

Headache Diagnosis in Primary Care

Introduction: Doctors in primary care are responsible for diagnosing and managing patients with headache, but frequently lack confidence in doing so. We aimed to compare Family Practitioners’ (FPs) diagnosis of headaches to classification based on a symptom questionnaire, and to describe how classification links to other important clinical features. Methods: This was an observational study of patients attending primary care doctors for headache. Main outcome measures: Patients completed a questionnaire including the Headache Impact Test, the Migraine Disability Assessment Score, the Hospital Anxiety and Depression Scale, the Illness Perceptions Questionnaire, a satisfaction scale, a service use inventory and a symptom questionnaire rated by two Practitioners with Special Interest (PSIs) in Headache. Results: 255 patients completed questionnaires. There was low agreement between FP diagnosis and classification using the symptom questionnaire. FPs frequently did not use the diagnosis migraine, when patient reported symptoms which justified this. FPs did not classify patients with ≥15 days of headache separately as chronic daily headache (CDH), and this could be because the classification system used does not have that code. Patients classified as CDH using the symptom questionnaire reported more disability, more symptoms of anxiety and depression (HADS), more service use, and less satisfaction with FP care. Conclusion: Patients, who present with headache in primary care, tend to receive non-specific diagnoses. Having a system that would allow separate classification of people with headache of ≥ 15 days a month might help FPs to explore and address associated features with patients in terms of disability, psychological co-morbidity and cost, and improve satisfaction with care

Regression of left ventricular mass following conversion from conventional hemodialysis to thrice weekly in-centre nocturnal hemodialysis

<p>Abstract</p> <p>Background</p> <p>Increased left ventricular mass (LVM) is associated with adverse outcomes in patients receiving chronic hemodialysis. Among patients receiving conventional hemodialysis (CHD, 3×/week, 4 hrs/session), we evaluated whether dialysis intensification with in-centre nocturnal hemodialysis (INHD, 3×/week, 7-8 hrs/session in the dialysis unit) was associated with regression of LVM.</p> <p>Methods</p> <p>We conducted a retrospective cohort study of CHD recipients who converted to INHD and received INHD for at least 6 months. LVM on the first echocardiogram performed at least 6 months post-conversion was compared to LVM pre-conversion. In a secondary analysis, we examined echocardiograms performed at least 12 months after starting INHD. The effect of conversion to INHD on LVM over time was also evaluated using a longitudinal analysis that incorporated all LVM data on patients with 2 or more echocardiograms.</p> <p>Results</p> <p>Thirty-seven patients were eligible for the primary analysis. Mean age at conversion was 49 ± 12 yrs and 30% were women. Mean pre-conversion LVM was 219 ± 66 g and following conversion, LVM declined by 32 ± 58 g (p = 0.002). Among patients whose follow-up echocardiogram occurred at least 12 months following conversion, LVM declined by 40 ± 56 g (p = 0.0004). The rate of change of LVM decreased significantly from 0.4 g/yr before conversion, to -11.7 g/yr following conversion to INHD (p < 0.0001).</p> <p>Conclusion</p> <p>Conversion to INHD is associated with a significant regression in LVM, which may portend a more favourable cardiovascular outcome. Our preliminary findings support the need for randomized controlled trials to definitively evaluate the cardiovascular effects of INHD.</p

The Shapes of Flux Domains in the Intermediate State of Type-I Superconductors

In the intermediate state of a thin type-I superconductor magnetic flux penetrates in a disordered set of highly branched and fingered macroscopic domains. To understand these shapes, we study in detail a recently proposed "current-loop" (CL) model that models the intermediate state as a collection of tense current ribbons flowing along the superconducting-normal interfaces and subject to the constraint of global flux conservation. The validity of this model is tested through a detailed reanalysis of Landau's original conformal mapping treatment of the laminar state, in which the superconductor-normal interfaces are flared within the slab, and of a closely-related straight-lamina model. A simplified dynamical model is described that elucidates the nature of possible shape instabilities of flux stripes and stripe arrays, and numerical studies of the highly nonlinear regime of those instabilities demonstrate patterns like those seen experimentally. Of particular interest is the buckling instability commonly seen in the intermediate state. The free-boundary approach further allows for a calculation of the elastic properties of the laminar state, which closely resembles that of smectic liquid crystals. We suggest several new experiments to explore of flux domain shape instabilities, including an Eckhaus instability induced by changing the out-of-plane magnetic field, and an analog of the Helfrich-Hurault instability of smectics induced by an in-plane field.Comment: 23 pages, 22 bitmapped postscript figures, RevTex 3.0, submitted to Phys. Rev. B. Higher resolution figures may be obtained by contacting the author

Rationale and Design of the Genetic Contribution to Drug Induced Renal Injury (DIRECT) Study

IntroductionNephrotoxicity from drugs accounts for 18% to 27% of cases of acute kidney injury. Determining a genetic predisposition may potentially be important in minimizing risk. The aims of this study are as follows: to determine whether a genetic predisposition exists for the development of drug-induced kidney disease (DIKD), using genome-wide association and whole-genome sequencing studies; to describe the frequency, course, risk factors, resolution and outcomes of DIKD cases; to investigate the role of ethnic/racial variability in the genetics of DIKD; and to explore the use of different tools establishing causality of DIKD.MethodsA total of 800 patients will be enrolled worldwide and blood samples for DNA collected. Data on the patient risk factors, vital signs, laboratory parameters, drug exposure, and DIKD course will be recorded. A panel of nephrologists will adjudicate all cases. Genome-wide association studies will be conducted using population controls matched on biogeographic ancestry to determine whether there is a genetic predisposition to DIKD. The primary endpoint is the identification of specific drug-related polymorphisms associated with DIKD. Secondary endpoints include the following: frequency of DIKD by causal drug and drug combinations; DIKD genetic variability; exploration of causality assessment tools; risk factor identification; description of the course of DIKD, including mortality and dialysis dependency at hospital discharge and 28 and 90 days post-event.ResultsData are currently being analyzed. Results are pending.DiscussionThe Genetic Contribution to Drug Induced Renal Injury (DIRECT) study will be the first observational cohort study to investigate the genetic determinants of DIKD. If the trial is positive, its findings will potentially translate into safer patient outcomes, by genotypic individualization of therapy and minimization of harm

Nucleation and Growth of the Superconducting Phase in the Presence of a Current

We study the localized stationary solutions of the one-dimensional time-dependent Ginzburg-Landau equations in the presence of a current. These threshold perturbations separate undercritical perturbations which return to the normal phase from overcritical perturbations which lead to the superconducting phase. Careful numerical work in the small-current limit shows that the amplitude of these solutions is exponentially small in the current; we provide an approximate analysis which captures this behavior. As the current is increased toward the stall current J*, the width of these solutions diverges resulting in widely separated normal-superconducting interfaces. We map out numerically the dependence of J* on u (a parameter characterizing the material) and use asymptotic analysis to derive the behaviors for large u (J* ~ u^-1/4) and small u (J -> J_c, the critical deparing current), which agree with the numerical work in these regimes. For currents other than J* the interface moves, and in this case we study the interface velocity as a function of u and J. We find that the velocities are bounded both as J -> 0 and as J -> J_c, contrary to previous claims.Comment: 13 pages, 10 figures, Revte

Canalization of the evolutionary trajectory of the human influenza virus

Since its emergence in 1968, influenza A (H3N2) has evolved extensively in genotype and antigenic phenotype. Antigenic evolution occurs in the context of a two-dimensional 'antigenic map', while genetic evolution shows a characteristic ladder-like genealogical tree. Here, we use a large-scale individual-based model to show that evolution in a Euclidean antigenic space provides a remarkable correspondence between model behavior and the epidemiological, antigenic, genealogical and geographic patterns observed in influenza virus. We find that evolution away from existing human immunity results in rapid population turnover in the influenza virus and that this population turnover occurs primarily along a single antigenic axis. Thus, selective dynamics induce a canalized evolutionary trajectory, in which the evolutionary fate of the influenza population is surprisingly repeatable and hence, in theory, predictable.Comment: 29 pages, 5 figures, 10 supporting figure

Recombinant T-Cell Receptor Ligand (RTL) for Treatment of Multiple Sclerosis: A Double-Blind, Placebo-Controlled, Phase 1, Dose-Escalation Study

Background. Recombinant T-cell receptor ligand 1000 (RTL1000) is a single-chain protein construct containing the outer two domains of HLA-DR2 linked to myelin-oligodendrocyte-glycoprotein- (MOG-) 35–55 peptide. Analogues of RTL1000 induce T-cell tolerance, reverse clinical and histological disease, and promote repair in experimental autoimmune encephalomyelitis (EAE) in DR2 transgenic, C57BL/6, and SJL/J mice. Objective. Determining the maximum tolerated dose, safety, and tolerability of RTL1000 in multiple sclerosis (MS) subjects. Methods. This was a multicenter, Phase I dose-escalation study in HLA-DR2+ MS subjects. Consecutive cohorts received RTL1000 doses of 2, 6, 20, 60, 200, and 100 mg, respectively. Subjects within each cohort randomly received a single intravenous infusion of RTL1000 or placebo at a 4 : 2 ratio. Safety monitoring included clinical, laboratory, and brain magnetic resonance imaging (MRI) evaluations. Results. Thirty-four subjects completed the protocol. All subjects tolerated the 2–60 mg doses of RTL1000. Doses ≥100 mg caused hypotension and diarrhea in 3 of 4 subjects, leading to discontinuation of further enrollment. Conclusions. The maximum tolerated dose of RTL1000 in MS subjects is 60 mg, comparable to effective RTL doses in EAE. RTL1000 is a novel approach for MS treatment that may induce immunoregulation without immunosuppression and promote neural repair

Comprehensive comparative outcomes in children with congenital heart disease: The rationale for the Congenital Catheterization Research Collaborative

Clinical research in the treatment of patients with congenital heart disease (CHD) is limited by the wide variety of CHD manifestations and therapeutic options as well as the generally low incidence of CHD. The availability of comprehensive, contemporary outcomes studies is therefore limited. This inadequacy may result in a lack of data‐driven medical decision making. In 2013, clinician scientists at two centers began a research collaboration, the Congenital Catheterization Research Collaborative (CCRC). Over time, the CCRC has grown to include nine cardiac centers from across the United States, with a common data coordinating center. The CCRC seeks to generate high‐quality, contemporary, statistically robust, and generalizable outcomes research which can help address important clinical questions in the treatment of CHD. To date, the CCRC has reported on multicenter outcomes in: neonates with congenital aortic stenosis, infants undergoing right ventricular decompression for pulmonary atresia and intact ventricular septum, and infants with ductal‐dependent pulmonary blood flow. The CCRC has been successful at leveraging large multicenter cohorts of patients in a contemporary period to perform comparative studies. In the future, the CCRC plans to continue to perform hypothesis‐driven retrospective and prospective observational studies of CHD populations where controversy exists or where novel interventions or therapies have emerged. Quality improvement efforts including lesion‐specific registry development may be an additional potential future target.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149494/1/chd12737.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149494/2/chd12737_am.pd