Multiple Sclerosis Performance Test: Technical Development and Usability.

INTRODUCTION: In the clinic, the assessment of patients with multiple sclerosis (MS) is typically qualitative and non-standardized. OBJECTIVES: To describe the MS Performance Test (MSPT), an iPad Air® 2 (Apple, Cupertino, CA, USA)-based neurological assessment platform allowing patients to input relevant information without the aid of a medical technician, creating a longitudinal, clinically meaningful, digital medical record. To report results from human factor (HF) and usability studies, and the initial large-scale implementation in a practice setting. METHODS: The HF study examined use-error patterns in small groups of MS patients and healthy controls (n = 14), the usability study assessed the effectiveness of patient interaction with the tool by patients with a range of MS disability (n = 60) in a clinical setting, and the implementation study deployed the MSPT across a diverse population of patients (n = 1000) in a large MS center for routine clinical care. RESULTS: MSPT assessments were completed by all users in the HF study; minor changes to design were recommended. In the usability study, 73% of patients with MS completed the MSPT, with an average administration time of 32 min; 85% described their experience with the tool as satisfactory. In the initial implementation for routine care, 84% of patients with MS completed the MSPT, with an average administration time of 28 min. CONCLUSION: Patients with MS with varying disability levels completed the MSPT with minimal or no supervision, resulting in comprehensive, efficient, standardized, quantitative, clinically meaningful data collection as part of routine medical care, thus allowing for large-scale, real-world evidence generation. FUNDING: Biogen. TRIAL REGISTRATION: NCT02664324.

Pseudoquiste pancreático complicado. reporte de un caso y revisión de la literatura / Complicated pancreatic pseudocyst: report of one case and literature review

Se presenta un caso de seudoquiste pancreático complicado (hemorragia intraquística), siete meses después de un episodio de pancreatitis aguda aparentemente resuelta, el cual fue drenado quirúrgicamente por medio de una cistogastrostomía interna con muy buenos resultados. Se hace una revisión de las características clínicas, radiológicas y modalidades terapéuticas de esta patología que ha cobrado mayor importancia debido al estudio radiológico cada vez utilizado en el diagnóstico de patología pancreática.

Limits to Catalysis by Ribonuclease A.

Bovine pancreatic ribonuclease A (RNase A) catalyzes the cleavage of the P-O(5') bond in RNA. Although this enzyme has been the object of much landmark work in bioorganic chemistry, the nature of its rate-limiting transition state and its catalytic rate enhancement had been unknown. Here, the value of k(cat)/K(m) for the cleavage of UpA by wild-type RNase A was found to be inversely related to the concentration of added glycerol. In contrast, the values of k(cat)/K(m) for the cleavage of UpA by a sluggish mutant of RNase A and the cleavage of the poor substrate UpOC(6)H(4)-p-NO(2) by wild-type RNase A were found to be independent of glycerol concentration. Yet, UpA cleavage by the wild-type and mutant enzymes was found to have the same dependence on sucrose concentration, indicating that catalysis of UpA cleavage by RNase A is limited by desolvation. The rate of UpA cleavage by RNase A is maximal at pH 6.0, where k(cat) = 1.4 × 10(3) s(-1) and k(cat)/K(m) = 2.3 × 10(6) M(-1)s(-1) at 25°C. At pH 6.0 and 25°C, the uncatalyzed rate of [5,6-(3)H]Up[3,5,8-(3)H]A cleavage was found to be k(uncat) = 5 × 10(-9) s(-1) (t(1/2) = 4 years). Thus, RNase A enhances the rate of UpA cleavage by 3 × 10(11)-fold by binding to the transition state for P-O(5') bond cleavage with a dissociation constant of <2 × 10(-15) M.