Infectious Aortitis Due to Salmonella Species Masquerading as Lung Malignancy.

Infectious aortitis is a rare but devastating vascular infection with mortality exceeding 40%. Early diagnosis is crucial but often hampered by radiographic mimickers. We report a patient who was thought to have lung cancer but ultimately found to have an infected aortic aneurysm and bacteremia owing to Salmonella species. Owing to surgical contraindications, he was treated palliatively with an initial regimen of intravenous ampicillin/sulbactam followed by lifelong oral antibiotic suppression. He ultimately rejected his diagnosis, discontinued medications, and was lost to follow-up. (Level of Difficulty: Intermediate.).

Temperature-responsive solid-liquid separations with charged block-copolymers of poly(N-isopropyl acryamide).

Temperature responsive charged block-copolymers of poly(N-isopropylacrylamide) (PNIPAM) have been used in the solid-liquid separation of alumina mineral particles from aqueous solution. The effects of temperature, polymer charge-sign and fraction of charged segment have been investigated. Batch settling and adsorption studies showed that rapid sedimentation results for suspensions with polymers of opposite charge-sign to the particle surface-charge (counterionic) at 50 °C. Cooling the suspensions after flocculation at 50 °C was found to increase the final solids volume fraction of the sediment beds formed through a mechanism related to partial desorption of polymer and the reduction of the hydrophobic attraction. Suspension stability results after dosing with polymers of similar charge-sign to the particle surface-charge (co-ionic) at both 25 and 50 °C. Increasing the amount of polymer charge increased the influence of polymer charge-sign on the adsorption and solid-liquid separation behavior. The performance of the charged block copolymers are compared to that of the random charged copolymer and neutral homopolymer PNIPAM structures.

Segmental Arterial Mediolysis (SAM) Leading to Chronic Renal Insufficiency.

BACKGROUND: Segmental arterial mediolysis (SAM) is a rare self-limiting non-atherosclerotic, non-inflammatory vasculopathy. SAM typically affects the visceral arteries of the abdomen to include the celiac, mesenteric, and renal arteries. SAM has a favorable prognosis in most cases with an asymptomatic course but can have mortality rates as high as 50% due to acute aneurysmal rupture. Very few cases of adverse long-term sequelae involving SAM have been described, and this report of chronic kidney disease represents a sentinel case illustrating that chronic disease can and does occur as a result of SAM and should be investigated for at follow-up. CASE PRESENTATION: In this case report, we describe a case of a 45-year-old male with erectile dysfunction but without any readily identifiable risk factors for chronic kidney disease (CKD) or vasculopathy, who presented with bilateral renal infarction and parenchymal infarcts due to SAM and who subsequently developed CKD at follow-up. We conduct a mini-literature review that discusses the pathogenesis of SAM in the context of vasospastic diseases, as well as compares the outcomes of observation-only, versus medical-management, versus endovascular-interventions in patients with SAM. CONCLUSION: This is the first case to our knowledge of CKD occurring as an outcome of SAM without any preceding significant comorbidity, highlighting that whereas SAM is of itself rare and typically resolves, chronic disease can linger and should be evaluated for on follow-up. Further, we argue that radiological evidence of precursor vasospastic disease may exist in several locations apart from the index lesion and thus warrants wider whole-body radiographic exploration for lesions as an opportunity to prevent chronic sequelae as illustrated in this case report from occurring. Finally, a review of published case-series suggests that disease progression is less likely to occur after endovascular-intervention compared to observation-only or medical management and the risk of intervention vs conservative management should therefore be discussed with the patient.

Cashew-Induced Oxalate Nephropathy: A Rare Cause of Acute Renal Failure.

We present a rare case of cashew-induced oxalate nephropathy in a 69 year old veteran male with history of type 2 diabetes mellitus, nephrolithiasis, and undiagnosed chronic kidney disease (CKD). Oxalate nephropathy is a rare cause of acute renal failure with poor prognosis. The various causes of oxalate nephropathy are categorized as primary or secondary hyperoxaluria. Primary hyperoxaluria is caused by genetic mutation in genes involved in the metabolism of glyoxylate. Secondary hyperoxaluria is caused by mal-absorptive state, excessive intake of oxalate-rich diet, inflammatory diseases, and medications such as orlistat and antibiotics. Diet-induced oxalate nephropathy is often identified after unexplained acute kidney injury in patients with underlying CKD. Definitive diagnosis requires renal biopsy as laboratory tests are non-specific. A simple dietary history in CKD patients during routine primary care visit may lead to early diagnosis and lead to prevention of acute renal failure and progression of renal disease.

Atrial fibrillation as a presenting symptom of Cardiac Sarcoid.

We submit an unusual presentation of spontaneous atrial fibrillation in a young fit active-duty U.S. military African-American male without evidence of structural heart disease. His atrial fibrillation was refractory to several ablation treatments over the course of 3 years. Subsequently he was diagnosed with extracardiac sarcoidosis and fluorodeoxyglucose-positron emission tomography (FDG-PET) scan identified bi-atrial hypermetabolic lesions, concerning for cardiac sarcoidosis. Given the low incidence of atrial fibrillation in patients < 45 years-of-age, this case report aims to underscore consideration of cardiac sarcoidosis as a subclinical contributor towards developing atrial fibrillation in the appropriate patient population. Broadly more investigations are needed to explore the role of cardiac sarcoidosis with atrial involvement and the likelihood of developing atrial arrhythmias.

A Case of Cardiac Papillary Fibroelastoma - An Increasingly Described Cardiac Tumor with Fatal Consequences.

Papillary fibroelastomas (PFE) are rare primary cardiac tumors characterized by non-malignant, pedunculated, endocardial lesions with a significant risk of embolic potential and death. With improvements in the imaging quality and availability of transthoracic echocardiograms (TTE), the diagnosis of PFE has become more common in the last 2 decades. PFE is changing from a rare "zebra" diagnosis to one that community providers will encounter in their practice and must appropriately treat to prevent morbidity and mortality. Data shows that there are significant survival and morbidity benefit associated with surgical excision over non-operative management, with the benefit of anticoagulation remaining unclear at this time. We report a case describing the diagnostic workup and management of a 58-year-old woman who presented with an unidentified endocardial mass determined to be a PFE. Based on current literature, we favor a strategy of early surgical excision of PFE for an optimal reduction in mortality and thromboembolic sequelae associated with this pathology.

Cooperative catalysis with block copolymer micelles: a combinatorial approach.

A rapid approach to identifying complementary catalytic groups using combinations of functional polymers is presented. Amphiphilic polymers with "clickable" hydrophobic blocks were used to create a library of functional polymers, each bearing a single functionality. The polymers were combined in water, yielding mixed micelles. As the functional groups were colocalized in the hydrophobic microphase, they could act cooperatively, giving rise to new modes of catalysis. The multipolymer "clumps" were screened for catalytic activity, both in the presence and absence of metal ions. A number of catalyst candidates were identified across a wide range of model reaction types. One of the catalytic systems discovered was used to perform a number of preparative-scale syntheses. Our approach provides easy access to a range of enzyme-inspired cooperative catalysts.

Temperature responsive flocculation and solid-liquid separations with charged random copolymers of poly(N-isopropyl acrylamide).

Temperature-responsive random copolymers based on poly(N-isopropyl acrylamide) (PNIPAM) with 15 mol% of either acrylic acid or dimethylaminoethyl acrylate quaternary chloride were prepared. The effect of the charge and its sign were investigated in the solid-liquid separation of silica and alumina mineral suspensions. The results were compared to PNIPAM homopolymer of similar molecular weight. PNIPAM copolymers of the same charge as the particles (co-ionic PNIPAM) act as dispersants at both 25°C and 50°C. Flocculation occurs when counter-ionic PNIPAM facilitates selective aggregation and rapid sedimentation of minerals at both 25°C and 50°C. Adsorption and desorption studies showed that, unlike non-ionic PNIPAM, little desorption of the counter-ionic copolymers from the oxides occurred after cooling a suspension from 50°C to below the lower critical solution temperature. Thus, incorporation of counter-ionic charge into the temperature sensitive polymer PNIPAM was found to reduce the sediment bed consolidation upon cooling when compared to PNIPAM homopolymers. The lack of secondary consolidation upon cooling is attributed to attractive inter-particle forces, such as conventional polyelectrolyte flocculation mechanisms (bridging, charge neutralization or charge patch) which persist at both 25°C and 50°C when counter-ionic PNIPAM is used. On the other hand, it was possible to obtain rapid sedimentation with the counter-ionic PNIAPMs even when they were added to the suspension already at 50°C, a process which has not been possible with neutral PNIPAM homopolymers.

Solid-liquid separations with a temperature-responsive polymeric flocculant: effect of temperature and molecular weight on polymer adsorption and deposition.

The effects of temperature and molecular weight of the temperature-responsive polymer, poly(N-isopropylacrylamide) (PNIPAM) were investigated in the solid-liquid separation of silica and alumina mineral particles. Suspensions dosed with PNIPAM at 25 degrees C were stable and did not settle. When the temperature was raised above the polymer lower critical solution temperature (LCST) (>32 degrees C), the suspensions were found to have high settling rates, large particle aggregate sizes and high suspension shear yield stresses (tau(y)). The sediment bed solids volume fraction (phi(f)), of these suspensions was found to increase after a temperature decrease below the polymer LCST and was attributed to a decrease in the attractive particle-particle interactions as shown by a corresponding decrease in shear yield stress, with decreasing temperature. Settling rates were found to increase with molecular weight when suspensions were dosed at 25 degrees C and settled at 50 degrees C. Increasing polymer molecular weight resulted in increased molecular polymer adsorption at 25 degrees C. Greater initial adsorbed amounts of polymer on the surface produced more nucleation sites for deposition of additional polymer as the temperature was increased from 25 degrees C to above the LCST where polymer phase separation occurred. When the polymer was dosed at 50 degrees C, the rate of sedimentation was very low. Under these conditions, the polymer molecules associate with each other to form polymer aggregates of typically 1250 nm diameter. These colloidal polymer aggregates do not readily deposit on the particles surfaces such that mineral particle aggregation does not readily occur.

Temperature controlled surface hydrophobicity and interaction forces induced by poly (N-isopropylacrylamide).

Poly (N-isopropylacrylamide) (PNIPAM) is a temperature responsive polymer. At temperature below its lower critical solution temperature (LCST 32 degrees C) PNIPAM is soluble in water and hydrophilic. At temperature above the LCST, the polymer becomes hydrophobic and insoluble in water. At temperatures above the LCST, PNIPAM has been shown to induce flotation of previously hydrophilic minerals. The mechanism is believed to be an increase in particle hydrophobicity when PNIPAM adsorbs to the particle surfaces at high temperature. This paper investigates the interaction forces between bare silica surfaces in PNIPAM solutions. The influence of three phase contact angles on these interactions, in the presence of polymers of different molecular weights, is also examined. It was found that the presence of PNIPAM on silica surfaces significantly increases their hydrophobicity at a temperature above the LCST. The AFM measurements of surface forces at high temperature also showed that strong adhesion is present between the PNIPAM coated surfaces, which is absent in the absence of polymer. These findings lead to the conclusion that the detected attractive force and subsequent adhesion result from hydrophobic attraction induced by PNIPAM at temperature above the LCST.