New Paradigms in the Histopathology of NAFLD

Non-alcoholic fatty liver disease (NAFLD) is a rapidly growing global health problem. It can be separated histologically into two broad groups: steatosis, which usually follows a benign clinical course and non-alcoholic steatohepatitis (NASH) that typically has hepatocyte ballooning, necroinflammatory activity and can progress to fibrosis and cirrhosis. More recently the histological spectrum has expanded with the recognition of a paediatric pattern of NASH that has portal-based inflammation and fibrosis without ballooning. An overlap pattern is also described. There is increasing interest in the portal changes of NASH as these correlate with the progression of fibrosis. Disease-associated hepatocyte senescence appears to trigger an alternative regenerative pathway and the development of a periportal ductular reaction (DR), which in turn may have a role in progressive fibrogenesis. Portal inflammation, particularly in association with the DR, is an area of recent study.     

Risk factors for the development of acute lung injury in patients with infectious pneumonia

ABSTRACT: INTRODUCTION: Although pneumonia has been identified as the single most common risk factor for acute lung injury (ALI), we have a limited knowledge as to why ALI develops in some patients with pneumonia and not in others. The objective of this study was to determine frequency, risk factors, and outcome of ALI in patients with infectious pneumonia. METHODS: A retrospective cohort study of adult patients with microbiologically positive pneumonia, hospitalized at two Mayo Clinic Rochester hospitals between January 1, 2005, and December 31, 2007. In a subsequent nested case-control analysis, we evaluated the differences in prehospital and intrahospital exposures between patients with and without ALI/acute respiratory distress syndrome (ARDS) matched by specific pathogen, isolation site, gender, and closest age in a 1:1 manner. RESULTS: The study included 596 patients; 365 (61.2%) were men. The median age was 65 (IQR, 53 to 75) years. In total, 171 patients (28.7%) were diagnosed with ALI. The occurrence of ALI was less frequent in bacterial (n = 99 of 412, 24%) compared with viral (n = 19 of 55, 35%), fungal (n = 39 of 95, 41%), and mixed isolates pneumonias (n = 14 of 34, 41%; P = 0.002). After adjusting for baseline severity of illness and comorbidities, patients in whom ALI developed had a markedly increased risk of hospital death (ORadj 9.7; 95% CI, 6.0 to 15.9). In a nested case-control study, presence of shock (OR, 8.9; 95% CI, 2.8 to 45.9), inappropriate initial antimicrobial treatment (OR, 3.2; 95% CI, 1.3 to 8.5), and transfusions (OR, 4.8; 95% CI, 1.5 to 19.6) independently predicted ALI development. CONCLUSIONS: The development of ALI among patients hospitalized with infectious pneumonia varied among pulmonary pathogens and was associated with increased mortality. Inappropriate initial antimicrobial treatment and transfusion predict the development of ALI independent of pathogen.     

Visual Loss Due to Wernicke Syndrome Following Gastric Bypass

Purpose: To report a case of Wernicke encephalopathy after gastric bypass surgery resulting in vision loss, ophthalmoplegia, and ataxia, all of which reversed with a single dose of IV thiamine. Methods: Observational case report. Results: A 34-year-old woman presented with decreased vision and intermittent diplopia after gastric bypass surgery. She was found to have bilateral limitation of horizontal gaze, decreased vision with bilateral central scotoma and mild disc edema OU. Her cranial magnetic resonance imaging (MRI) was normal. A presumptive diagnosis of Wernicke encephalopathy was made. The patient was admitted, and a single dose of IV thiamine reversed the ophthalmoplegia and vision loss within 24 hours. Conclusion: Wernicke encephalopathy should be considered in patients with vision loss after gastric bypass surgery. The classic triad of confusion, ataxia, and ophthalmoplegia may not be present and, although uncommon, the findings of optic disc edema and vision loss should not deter the clinician from making the diagnosis. Replacement thiamine if given promptly may rapidly reverse the findings.