Oral contraceptive progestins and angiotensin-dependent control of the renal circulation in humans

Oral contraceptive (OC) use is associated with increased intra-renal renin-angiotensin-aldosterone system (RAA System) activity and risk of nephropathy, though the contribution of progestins contained in the OC in the regulation of angiotensin-dependent control of the renal circulation has not been elucidated. Eighteen OC users (8 non-diabetic, 10 Type 1 diabetic) were studied in high salt balance, a state of maximal RAA System suppression. Progestational and androgenic activity of the progestin in each OC was standardized to that of the reference progestin norethindrone. Renal plasma flow (RPF) was measured by paraaminohippurate clearance at baseline and in response to angiotensin converting enzyme (ACE)-inhibition. There was a positive correlation between OC progestational activity and the RPF response to ACE-inhibition (r=0.52, p=0.03). Similar results were noted with OC androgenic activity (r=0.54, p=0.02). On subgroup analysis, only non-diabetic subjects showed an association between progestational activity and angiotensin-dependent control of the renal circulation (r=0.71, p=0.05 non-diabetic; r=0.14, p=0.7 diabetic; p=0.07 between groups). Similar results were noted with respect to androgenic activity (r=0.88, p=0.005 non-diabetic; r=−0.33, p=0.3 diabetic; p=0.002 between groups). Our results suggest that the OC progestin component is a significant influence on the degree of angiotensin-dependent control of the renal circulation, though these findings may not apply to women with diabetes

Characterization of murine NYX

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Xanthogranulomatous pyelonephritis presenting as acute pleuritic chest pain: a case report

Abstract Background Xanthogranulomatous pyelonephritis is a rare and serious manifestation of chronic kidney inflammation that can be life-threatening if not recognized and treated appropriately, often with antibiotics and surgery. Affected patients are most commonly females in their fifth or sixth decade of life with a background of obstructive uropathy, nephrolithiasis, or recurrent urinary tract infections who present with vague nonspecific symptoms. Case presentation A 43-year-old woman of Russian ethnicity with a history of nephrolithiasis presented to our emergency department with new left-sided pleuritic chest pain amid a 6-week history of constitutional symptoms including fevers, night sweats, and 7 kg of weight loss. Workup for acute coronary syndrome and pulmonary embolism in our emergency department was negative. Given that she was clinically unwell, she was admitted to internal medicine to expedite workup for the cause of her symptoms. A broad differential diagnosis for various infectious, inflammatory/autoimmune, and neoplastic processes was considered. Based on classic radiographic and histopathologic findings, she was ultimately diagnosed with xanthogranulomatous pyelonephritis of her left kidney, which was a direct consequence of chronic inflammation. This inflammation exhibited spread to local tissues and across her left hemidiaphragm, resulting in a unilateral pleural effusion which explained her chest discomfort. She was treated with antibiotics administered intravenously and urgent total nephrectomy with a good functional outcome. Conclusions Our case illustrates an uncommon but clinically important do-not-miss diagnosis that underlies a common clinical presentation of pleuritic chest pain. The case underscores the importance of maintaining a broad differential diagnosis and organized approach when treating patients with undifferentiated clinical presentations

Working electrode geometry effect : a new concept for fabrication of patterned polymer brushes via SI-seATRP at ambient conditions

First reports concerning the use of atom transfer radical polymerization (ATRP) to prepare patterned hybrid materials appeared more than 20 years ago. However, the development of new methods of preparation of patterned materials is still at the forefront of scientific interest. In this paper, we describe surface-initiated simplified electrochemically mediated ATRP (SI-seATRP) under constant current conditions, used for the fabrication of patterned polymer brushes under ambient conditions at the microliter scale. It is shown that appropriate selection of surface and shape of the working electrode (WE) allows handling the polymerization of (meth)acrylates, acrylates and acrylamides directly on the laboratory bench. The complete procedure includes a minimum amount of reagents and an optimal amount of a catalytic complex equal to 300 ppm. The use of a platinum wire mesh electrode guarantees obtaining polymers forming unique patterns. The observed patterning phenomenon could be explained by the mechanism of electrochemically mediated ATRP (eATRP) and is directly related to the working electrode geometry, and diffusion of the catalyst CuIBr/TPMA (where TPMA: tris(2-pyridylmethyl)amine)

The role of plasmalogens in the photoreactivity of human retinal lipid extracts of different age groups

Purpose: Plasmalogens (PLs) constitute a specific subclass of phospholipids characterized by a vinyl-ether bond in SN-1 position of the glycerol backbone and account for 10% of total phospholipids in the retina, where are considered as sacrificial antioxidants. PLs above 50% of other phospholipids present in the retina contain polyunsaturated fatty acid (PUFA) chain in SN-2 position. In this work we analyzed the influence of PLs on of phospholipids naturally occurring in the human retina (SRL) in a model system and in retinal pigment epithelium cells in vitro. Methods: Lipid composition of human retinal extracts (RLE) has been determined by GC and LC/MS analysis. RLE and SRL with and without PLS were oxidized in the dark in liposomes equilibrated with air at 37°C. Blue-light induced photoreactivity of the oxidized lipid samples was measured in model systems and in ARPE-19 cells in vitro using time-resolved singlet oxygen phosphorescence at 1270nm, electron paramagnetic resonance (EPR) -oximetry, EPR-spin trapping and electrochemical detection of cholesterol hydroperoxides.Results: Human RLE are very sensitive to oxidation despite the presence of endogenous hydrophobic antioxidants. Both oxidised RLE and SRL generate singlet oxygen and superoxide anion upon irradiation with blue light. The observed photoreactivity of lipids extracted from human retinas increases with age of the donor. It also becomes more pronounced with autooxidation in case of both RLE and SRL.Conclusions: Our results indicate that plasmalogens mediate photoreactivity of retinal lipids in a complex way. It is detected by an increase in the photouptake of oxygen and decreased yields of singlet oxygen photogeneration by oxidized phospholipids