A bio-effect directed fractionation study for toxicological and chemical characterization of organic compounds in bottom sediment.

The major aim of this study was to characterize toxic organic compounds in bottom sediments from a PCB polluted bay. To overcome difficulties in pinpointing toxicants in complex environmental samples we applied a bio-effect directed (BED) fractionation approach and investigated the relationships between aromaticity, teratogenicity, and aryl hydrocarbon receptor (AhR) mediated toxicity. Hepatic ethoxyresorufin O-deethylase (EROD) activities and malformations were investigated in rainbow trout (Oncorhynchus mykiss) larvae exposed by injecting sediment extract and fractions (separated by their degree of aromaticity) thereof into newly fertilized eggs. Our results imply that non-additive effects get more pronounced the more complex the exposure. The fraction mainly composed of dicyclic aromatic compounds (DACs), including PCBs, was surprisingly less teratogenic than the fraction mainly composed of polycyclic aromatic compounds (PACs). A major part of the latter potential was isolated in a subfraction mainly composed of three- and four-ring compounds (including alkylated and sulphur-heterocyclic compounds). Though no clear relationship between aromaticity and EROD induction was observed, both the DAC- and the PAC-fractions contributed equally to the EROD induction potential. A major part of the PAC-fraction's induction potential came from a subfraction containing compounds with more than five rings. No clear relationship between teratogenicity and EROD induction was observed, underlining the need for a battery of biomarkers in estimating environmental risk. Two specific malformations not previously described in literature-asymmetric yolk sac and fin edema-could be tracked through the fractionation steps, suggesting that this BED-fractionation strategy is a reliable tool for pinpointing toxic compounds in the environment.     

Erratum to: Quantification of the Global and Local Complexity of the Epithelial-Connective Tissue Interface of Normal, Dysplastic, and Neoplastic Oral Mucosae Using Digital Imaging

published in Pathol. Res. Pract. 199/7: 475–482Page 480 of the above-mentioned article was incompletely printed in the published version due to a production error.Please, find in the following the page 480 in the complete version.We would like to apologize to our authors and readers for this mistake.URBAN & FISCHER Verlag     

Seipin accumulates and traps diacylglycerols and triglycerides in its ring-like structure

Lipid droplets (LDs) are intracellular organelles responsible for lipid storage, and they emerge from the endoplasmic reticulum (ER) upon the accumulation of neutral lipids, mostly triglycerides (TG), between the two leaflets of the ER membrane. LD biogenesis takes place at ER sites that are marked by the protein seipin, which subsequently recruits additional proteins to catalyze LD formation. Deletion of seipin, however, does not abolish LD biogenesis, and its precise role in controlling LD assembly remains unclear. Here, we use molecular dynamics simulations to investigate the molecular mechanism through which seipin promotes LD formation. We find that seipin clusters TG, as well as its precursor diacylglycerol, inside its unconventional ring-like oligomeric structure and that both its luminal and transmembrane regions contribute to this process. This mechanism is abolished upon mutations of polar residues involved in protein–TG interactions into hydrophobic residues. Our results suggest that seipin remodels the membrane of specific ER sites to prime them for LD biogenesis.

Lipid droplets (LDs) are the intracellular organelles responsible for fat accumulation (1). As such, they play a central role in lipid and cellular metabolism (1–4), and they are crucially involved in metabolic diseases such as lipodystrophy and obesity (5–7).Formation of LDs occurs in the endoplasmic reticulum (ER), where neutral lipids (NLs), namely triglycerides (TG) and cholesteryl esters, constituting the core of LDs are synthesized by acyltransferases that are essential for LD formation (8). The current model of LD formation posits that NLs are stored between the two leaflets of the ER bilayer, where they aggregate in nascent oblate lens-like structures with diameters of 40 to 60 nm (9) before complete maturation and budding toward the cytosol (10–13).Recent experiments suggest that LDs form at specific ER sites marked by the protein seipin (14) upon arrival of its interaction partner protein promethin/LDAF1 (lipid droplet organization [LDO] in yeast) (15–19). These recent observations confirm previous works showing that seipin, in addition to modulating LD budding and growth (14, 19–21) and LD–ER contacts (22, 23), is also a major player in the early stages of LD formation, as deletion of seipin leads to TG accumulation in the ER and a delay in the formation of, possibly aberrant, LDs (20, 24).The role of seipin in LD formation is potentially coupled to its function in regulating lipid metabolism (25, 26) and notably that of phosphatidic acid (PA) (27–31). Recently, seipin-positive ER loci have been shown to be part of a larger protein machinery that also includes membrane and lipid remodeling proteins of the TG synthesis pathway (32), most notably, Lipin (Pah1 in yeast) and FIT proteins (Yft2 and Scs3 in yeast), for which PA is either a known substrate (Lipin/Pah1) (33) or a likely one (FIT/Yft2/Scs3) (34).Despite this thorough characterization of the cellular role of seipin in LD formation, the molecular details of its mechanism remain mostly unclear. Recently, the structure of the luminal part of the seipin oligomer has been solved at 3.7 to 4.0 Å resolution using electron microscopy (27, 35), paving the way for the investigation of the relationship between its three-dimensional structure and its mode of action. These studies revealed that the luminal domain of seipin consists of an eight-stranded beta sandwich, together with a hydrophobic helix (HH), positioned toward the ER bilayer. Notably, the seipin oligomer assembles into a ring-like architecture, an unconventional assembly in lipid bilayers that rather resembles the shape of microbial pore-forming assemblies (36) or GroEL-GroES chaperones (37, 38).From a stochiometric point of view, both fluorescence and electron microscopy data are consistent with the presence of a single seipin oligomer per nascent LD (14, 15). Hence, the structure of the luminal part of seipin is consistent with two proposed modes of action: seipin could mark the sites of LD formation by controlling TG flow in and out of the nascent droplet (14), or, alternatively, seipin could help recognize and stabilize preexisting nascent droplets in the ER membrane (20, 21, 39). In both cases, however, the relationship between the role of seipin in LD formation and its ability to regulate lipid metabolism remains unclear.Here, we use coarse-grain (CG) molecular dynamics (MD) simulations to investigate the mechanism of seipin in molecular detail. We find that seipin is able to cluster TG molecules inside its ring-like structure and that both the transmembrane (TM) helices and the luminal domain contribute to this process. Diacylglycerol (DG), the lipid intermediate between TG and PA in the Kennedy pathway, also accumulates around seipin, further promoting the accumulation of TG at very low TG-to-phospholipids ratios. Our data suggest that by accumulating DG and TG molecules, seipin generates ER sites with a specific lipid composition that in turn could promote the sequential recruitment of additional TG- and DG-sensing proteins involved in LD formation, including promethin/LDOs, FIT/Yft2/Scs3, and perilipins.     

Nonalcoholic Fatty Liver Disease: Noninvasive Methods of Diagnosing Hepatic Steatosis

Hepatic steatosis is the buildup of lipids within hepatocytes. It is the simplest stage in nonalcoholic fatty liver disease (NAFLD). It occurs in approximately 30% of the general population and as much as 90% of the obese population in the United States. It may progress to nonalcoholic steatohepatitis, which is a state of hepatocellular inflammation and damage in response to the accumulated fat. Liver biopsy remains the gold standard tool to diagnose and stage NAFLD. However, it comes with the risk of complications ranging from simple pain to life-threatening bleeding. It is also associated with sampling error. For these reasons, a variety of noninvasive radiological markers, including ultrasound, computed tomography, magnetic resonance spectroscopy, and the controlled attenuation parameter using transient elastography and Xenon-133 scan have been proposed to increase our ability to diagnose NAFLD, hence avoiding liver biopsy. The aim of this review is to discuss the utility and accuracy of using available noninvasive diagnostic modalities for fatty liver in NAFLD.     

Angiotensin II type 1 receptor gene polymorphism and serum angiotensin-converting enzyme level in Egyptian children with systemic lupus erythematosus

Angiotensin II, the major effective molecule of the renin-angiotensin system, plays a vital role in the development of systemic lupus erythematosus (SLE). To study angiotensin II type 1 receptor (AT1R) gene polymorphism at (A1166C) in Egyptian children with SLE and its correlation with serum ACE level and SLE manifestations. AT1R gene polymorphism (A1166C) was done in 123 children with SLE in comparison to 100 healthy controls using polymerase chain reaction-based restriction fragment length polymorphism method (PCR-RFLP) and the tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) to confirm the results of the genotyping. Serum ACE level measurement was done using ELISA technique. The frequencies of C-containing genotypes (AC?+?CC) and C-allele of AT1R (A1166C) were significantly higher in SLE patients compared to controls (p?<?0.0001, OR?=?4.9, 95% CI?=?2.7–8.8; p ? 0.0001, OR?=?3.6, 95% CI?=?2.2–5.9, respectively). Lupus nephritis (LN) patients had significantly higher frequency of (AC?+?CC) genotypes and C-allele compared with controls (p ? 0.0001, OR?=?5.1, 95% CI?=?2.7–9.7; p ? 0.0001, OR?=?3.5, 95% CI?=?2.1–6.02, respectively). Mean serum ACE levels were significantly higher in SLE patients compared to controls (p ? 0.0001). There were no associations between AT1R gene polymorphism and serum ACE level and the clinical manifestations of SLE. The AT1R gene polymorphism can be considered a risk factor for the development of SLE in Egyptian children.     

Pre-Angioplasty Instantaneous Wave-Free Ratio Pullback Predicts Hemodynamic Outcome In Humans With Coronary Artery Disease: Primary Results of the International Multicenter iFR GRADIENT Registry

Objectives

The authors sought to evaluate the accuracy of instantaneous wave-Free Ratio (iFR) pullback measurements to predict post-percutaneous coronary intervention (PCI) physiological outcomes, and to quantify how often iFR pullback alters PCI strategy in real-world clinical settings.

HIV, metabolic syndrome X, inflammation, oxidative stress, and coronary heart disease risk

Differences on measures of metabolic syndrome X and coronary heart disease (CHD) risk, as well as potential pathophysiological mediators, inflammation, and oxidative stress, were examined as a function of HIV serostatus and highly active antiretroviral therapy (HAART) regimen with and without protease inhibitors (PIs). Data from 164 men and women, aged 18 to 55 yr, were used to compare 82 HIV⁺ subjects who were free of hepatitis C virus and were on a stable HAART regimen for ≥6 mo, with 82 seronegative subjects matched on age, sex, body mass index, and ethnicity. For the HIV⁺ subjects, after controlling for diabetes status and HIV disease progression, PI exposure was associated with greater oxidative stress, triglyceridemia, and lipidemia than it was for non-PI-exposed HIV⁺ subjects, and the risk of a future myocardial infarction was up to 56% greater in PI-exposed than in non-PI-exposed subjects and 129% greater than in controls. Although it is likely that the greatest proportion of CHD risk in the HIV⁺ subjects may be accounted for by pathological conditions linked to HIV infection in interaction with mediating processes such as inflammation, central obesity, and dyslipidemia, which was greater than in controls, it appears that PI medications may exacerbate oxidative stress and hypertriglyceridemia to enhance this risk.     

Association of anti-ribosomal P protein antibodies with neuropsychiatric and other manifestations of systemic lupus erythematosus

The objective of our study was to determine the prevalence of neuropsychiatric manifestations and anti-ribosomal P antibodies (aRP) in SLE and to examine the diagnostic utility and associations of aRP with neuropsychiatric and other disease manifestations. Thirty two consecutive SLE patients, diagnosed according to the updated 1997 ACR criteria, were studied. A full medical history, rheumatological, neurological, psychiatric examination, and psychometric evaluation, including a battery of tests for cognitive dysfunction and the Symptom Checklist-90-Revised depression and anxiety scales were administered to all patients. Disease activity was scored using the SLEDAI. Neuropsychiatric manifestations were diagnosed and categorized according to the 1999 ACR case definitions for 19 NPSLE syndromes. Laboratory and serologic tests including ANA, anti-ds DNA, anti-cardiolipin antibodies (aCL) and aRP (ELISA) were also carried out. Twenty six (81.2%) patients had one or more NP manifestations. Depression (59.4%), headache (46.9%) and cognitive dysfunction (37.5%) were the commonest NPSLE syndromes. Other less commonly detected manifestations included seizures, anxiety, acute confusional state, stroke, and psychosis. aRP was positive in seven (21.9%) patients, all of whom had one or more NPSLE syndromes. Patients with psychiatric manifestations in general and mood disorders in particular had significantly higher mean titers of aRP than patients without these disorders (p < 0.05). aRP were found to be significantly associated with a younger age at the onset of SLE, with more severe articular manifestations and with the presence but not the severity of depression. aRP were highly specific for NPSLE and depression, and they were highly sensitive for psychosis. Neuropsychiatric manifestations are found in 81.2% of unselected Egyptian SLE patients. The presence of aRP antibodies positively predicts patients with psychiatric manifestations in general and mood disorders in particular, for which aRP is specific, but not sensitive. However, aRP is sensitive for psychosis, so that its absence in patients with SLE may help exclude Lupus psychosis. The authors have no conflicts of interest or disclosures.     

Transurethral resection of ejaculatory duct in infertile men: outcome and predictors of success

Objectives

To evaluate the outcome of transurethral resection of the ejaculatory duct (TURED) in the treatment for ejaculatory duct obstruction (EDO) and define predictors of success.

Materials and methods

We retrospectively evaluated 23 infertile men between 2006 and 20011, who were diagnosed as having EDO. Inclusion criteria were azoospermia or oligozoospermia, low ejaculate volume, low ejaculate PH, little or no fructose in seminal plasma with normal serum levels of gonadotropins and testosterone and evidence of obstruction on transrectal ultrasonography (TRUS) or magnetic resonance images (MRI). Seventeen patients were diagnosed as complete EDO, and the remaining 6 were considered as having partial EDO. All patients were treated by TURED.

Results

Midline cysts were diagnosed in seven cases, and the remaining 16 patients had postinflammatory obstruction of ejaculatory ducts (ED). Overall, a significant improvement of semen quality was achieved after surgery. All patients with partial EDO showed improvements in semen parameters after TURED compared to 23.5?% (4/17) in those with complete EDO. Improvement in sperm count was 71.5?% and 31?% for patients with midline cysts and patients with non-cystic causes of EDO, respectively. Six (26?%) patients developed complications including epididymo-orchitis in 2, watery ejaculate in 3 and conversion to azoospermia in 1. Spontaneous pregnancies were achieved in 3 (13?%) cases: 2 (33.3?%) men with partial and 1 (5.9?%) with complete obstruction.

Conclusion

Partial EDO, whatever the etiology, has an excellent outcome after TURED. Complete EDO due to cysts appears to respond better than postinflammatory obstruction to TURED.