Causal structures and causal boundaries

We give an up-to-date perspective with a general overview of the theory of causal properties, the derived causal structures, their classification and applications, and the definition and construction of causal boundaries and of causal symmetries, mostly for Lorentzian manifolds but also in more abstract settings.Comment: Final version. To appear in Classical and Quantum Gravit

Cigarette Lighter Fluid Induced Gastric Ulcer: A Severe Complication of Delayed Foreign Body Removal

The majority of foreign bodies ingested pass uneventfully through the gastrointestinal tract without endoscopic intervention. Nevertheless, certain ingested objects pose a greater risk for complications and are more challenging to remove than others. This case report describes a 49-year-old male who swallowed a cigarette lighter causing a gastric ulcer. The lighter was successfully removed by flexible endoscopy using a polypectomy snare. Urgent removal is required due to the shape of the object and its hazardous contents. This is the first case report published in the United States describing cigarette lighter ingestion and management

Anticoagulation for the Pregnant Patient with a Mechanical Heart Valve, No Perfect Therapy: Review of Guidelines for Anticoagulation in the Pregnant Patient

Heart valve replacement with a mechanical valve requires lifelong anticoagulation. Guidelines currently recommend using a vitamin K antagonist (VKA) such as warfarin. Given the teratogenic effects of VKAs, it is often favorable to switch to heparin-derived therapies in pregnant patients since they do not cross the placenta. However, these therapies are known to be less effective anticoagulants subjecting the pregnant patient to a higher chance of a thrombotic event. Guidelines currently recommend pregnant women requiring more than 5 mg a day of warfarin be switched to alternative therapy during the first trimester. This case report highlights a patient who was switched to alternative therapy during her first pregnancy and suffered a devastating cerebrovascular accident (CVA). Further complicating her situation was during a subsequent pregnancy; this patient continued warfarin use during the first trimester and experienced multiple transient ischemic attacks (TIAs). This case highlights the increased risk of thrombotic events in pregnant patients with mechanical valves. It also highlights the difficulty of providing appropriate anticoagulation for the pregnant patient who has experienced thrombotic events on multiple anticoagulants

A Curious Case of Proximal Muscle Weakness with Eosinophilic Polymyositis

Eosinophilic polymyositis (EPM) is part of a rare disorder, eosinophilic myopathies (EM), which is a form of polymyositis characterized by the presence of eosinophils in muscle biopsy sections and occasionally blood eosinophilia. Herein, we are presenting an interesting case of eosinophilic polymyositis presenting with muscle pain with no other organ systems involved

Barriers to treatment of chronic hepatitis C with direct acting antivirals in an urban clinic

Introduction and aim: Direct-acting antiviral (DAA) agents are highly effective for treatment of chronic hepatitis C virus (HCV) yet access to treatment remains a serious challenge. The aim of this study was to identify barriers to treatment initiation with DAA-containing regimens in an urban clinic setting. Materials and methods: A retrospective cohort of all chronic HCV patients seen in an urban academic practice in Jacksonville, FL, USA from 1/2014 to 1/2017 was analyzed. Baseline characteristics were recorded and a review of medical records was performed to identify barriers to treatment initiation and overall success rates. Results: Two-hundred and forty patients with chronic HCV were analyzed. Fifty-six percent of patients were African-American and 63% were insured through Medicaid/county programs or uninsured. Sixty-nine percent had barriers to initiating antiviral therapy categorized as psychosocial (n = 112), provider (n = 26), medical (n = 20), and insurance-related factors (n = 7). The most commonly encountered psychosocial barriers included failure to keep appointments (79/240, 33%), active substance abuse (18/240, 8%), and failure to obtain laboratory testing (11/240, 5%). Overall, only 27% of patients evaluated were initiated on DAA-containing regimens with 18% reaching SVR12 within the 36-month study period. Conclusion: In conclusion, only 27% of patients who presented to an urban academic practice with chronic HCV received DAA-containing regimens over a 36-month period. Psychosocial issues were the major barriers to antiviral therapy. These findings illustrate the need for an integrated approach that addresses psychosocial factors as well as comorbidities and adherence to care in order to increase rates of HCV treatment in at risk patients