Developmental competence of IVM pig oocytes after SCNT in relation to the shrinkage pattern induced by hyperosmotic treatment

The objective of this study was to examine the developmental competence of IVM pig oocytes in relation to the pattern of morphologic changes after exposure to hyperosmotic medium to select oocytes of a higher quality. IVM oocytes were treated with a hyperosmotic (593 mOsm) medium containing NaCl, sorbitol, or sucrose. Oocytes that shrunk spherically (SSP oocytes) or in irregular shapes (SIR oocytes) were collected separately, and washed for 15 minutes in an isotonic (297 mOsm) medium for recovery. Irrespective of the chemicals used, hyperosmotic treatment of oocytes for 1 hour or 15 minutes did not alter embryonic development after parthenogenesis (PA) and SCNT. A significantly higher proportion of SSP oocytes developed to the blastocyst stage (34.0%) compared with SIR oocytes (15.8%) after PA. The intracellular glutathione content was significantly higher in SSP oocytes than in SIR oocytes. Conversely, the reactive oxygen species level was significantly higher in SIR oocytes than in SSP oocytes. The maturation promoting factor level as measured by p34^cdc2 kinase activity was not influenced by hyperosmotic treatment itself but was 1.3-fold higher (P < 0.05) in SSP oocytes than in SIR oocytes. When IVM oocytes were divided into two groups according to their diameters (large and small), and treated separately in hyperosmotic medium, significantly more SSP oocytes (71.4%) were found in the large oocytes than in the small oocytes (51.4%). Moreover, the proportion of metaphase II oocytes was significantly higher in SSP oocytes than in SIR oocytes in both groups (98.5% vs. 73.1% in large oocytes, and 92.2% vs. 48.0% in small oocytes). After SCNT, a significantly higher proportion of SSP oocytes displayed blastocyst formation (36.4%) than untreated (29.0%) and SIR oocytes (22.1%). Our results demonstrated that SSP oocytes were of a higher quality than SIR oocytes, which was shown by higher intracellular glutathione and maturation promoting factor levels, lower reactive oxygen species levels, and improved embryonic development to the blastocyst stage after PA and SCNT.     

Copper uptake induces self-assembly of 18.5 kDa myelin basic protein (MBP)

Myelin basic protein (MBP) is predominantly found in the membranes of the myelin sheath of the central nervous system and is involved in important protein-protein and protein-lipid interactions in vivo and in vitro. Furthermore, divalent transition metal ions, especially Zn²⁺ and Cu²⁺, seem to directly affect the MBP-mediated formation and stabilization of the myelin sheath of the central nervous system. MBP belongs to the realm of intrinsically disordered proteins, and only fragmentary information is available regarding its partial structure(s) or supramolecular arrangements. Here, using standard continuous wave and modern pulse electron paramagnetic resonance methods, as well as dynamic light scattering, we demonstrate the uptake and specific coordination of two Cu²⁺ atoms or one Zn²⁺ atom per MBP molecule in solution. In the presence of phosphates, further addition of divalent metal ions above a characteristic threshold of four Cu²⁺ atoms or two Zn²⁺ atoms per MBP molecule leads to the formation of large MBP aggregates within the protein solution. In vivo, MBP-MBP interactions may thus be mediated by divalent cations.     

Bioimpedance Analysis Parameters and Epicardial Adipose Tissue Assessed by Cardiac Magnetic Resonance Imaging in Patients With Heart Failure

There is increasing evidence that body composition should be considered as a systemic marker of disease severity in congestive heart failure (CHF). Prior studies established bioelectrical impedance analysis (BIA) as an objective indicator of body composition. Epicardial adipose tissue (EAT) quantified by cardiac magnetic resonance (CMR) is the visceral fat around the heart secreting various bioactive molecules. Our purpose was to investigate the association between BIA parameters and EAT assessed by CMR in patients with CHF. BIA and CMR analysis were performed in 41 patients with CHF and in 16 healthy controls. Patients with CHF showed a decreased indexed EAT (22 ± 5 vs. 34 ± 4 g/m², P < 0.001) and phase angle (PA) (5.5° vs. 6.4°, P < 0.02) compared to healthy controls. Linear regression analysis showed a significant correlation of CMR indexed EAT with left ventricular ejection fraction (LV‐EF) (r = 0.56, P < 0.001), PA (r = 0.31, P = 0.01), total body muscle mass (TBMM) (r = 0.41, P = 0.001), fat‐free mass (FFM) (r = 0.30, P = 0.02), and intracellular water (ICW) (0.47, P = 0.0003). Multivariable analysis demonstrated that LV‐EF was the only independent determinant of indexed EAT (P < 0.0001). Receiver operating characteristic curve analysis indicated good predictive performance of PA and EAT (area under the curve (AUC) = 0.86 and 0.82, respectively) with respect to cardiac death. After a follow‐up period of 5 years, 8/41 (19.5%) patients suffered from cardiac death. Only indexed EAT <22 g/m² revealed a statistically significant higher risk of cardiac death (P = 0.02). EAT assessed by CMR correlated with the BIA‐derived PA in patients with CHF. EAT and BIA‐derived PA might serve as additional prognostic indicators for survival in these patients. However, further clinical studies are needed to elucidate the prognostic relevance of these new findings.     

Arachidonic acid alleviates the detrimental effects of acetylsalicylic acid on human granulosa cells performance in vitro

Here, we investigated the biological effects of arachidonic acid (AA) in human cumulus granulosa cells (CGCs) after exposure to ASA. Cells were isolated from the follicular fluid and incubated with 0.5 mM acetylsalicylic acid (ASA) and 50 µM AA. Cell viability was analyzed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. E₂ and P₄ levels were measured by chemiluminescence assay. Expression of genes including CYP19A1, FACN, and SCD1 was measured by real‐time polymerase chain reaction assay. Oxidative status was analyzed by monitoring glutathione peroxidase activity. The fatty acid profile was analyzed by the gas chromatography technique. Enzyme‐linked immunosorbent assay was used to measure prostaglandin E₂ (PGE₂) in CGCs after exposure to ASA and AA. Protein levels of the estrogen receptor were studied by immunofluorescence staining. Ultrastructural changes were evaluated by transmission electron microscopy imaging. ASA treatment reduced E₂ production, Cyp19a1 expression, glutathione peroxidase (GPx) activity, and estradiol receptor expression in CGCs. The addition of AA prevented the ASA‐induced E₂ reduction (p < .05) and expression of Cyp19a1. Moreover, AA increased the antioxidant capacity of CGCs exposed to ASA by promoting GPx activity (p < .05). AA increased monounsaturated fatty acid/saturated fatty acid ratio compared with the ASA group (p < .05). AA supplementation triggered the synthesis and secretion of PGE₂ in ASA‐treated CGCS (p < .05). Cytoplasmic vacuolation observed in the ASA group and treatment with AA intensified vacuolation rate. The expression of the estrogen receptor was increased after AA supplementation. Data demonstrated that AA decreased the detrimental effects of ASA on human CGCs after 72 hr.     

Experimental Removal and Recovery of Subtidal Grazers Highlights the Importance of Functional Redundancy and Temporal Context

The extent to which different grazers are functionally redundant has strong implications for the maintenance of community structure and function. Grazing by red urchins (Strongylocentrotus franciscanus) on temperate rocky reefs can initiate a switch from invertebrate or macroalgal dominance to an algal crust state, but can also cause increases in the density of molluscan mesograzers. In this study, we tested the hypothesis that red urchins and lined chitons (Tonicella spp.) are redundant in the maintenance of available space, defined as encrusting algae and bare rock. In a factorial field experiment replicated at three sites, we reduced the densities of urchins and chitons on subtidal rock walls for nine months. The effects of grazers were interpreted in the context of natural temporal variation by monitoring the benthic community one year before, during, and after grazer removal. The removal of each grazer in isolation had no effect on the epilithic community, but the removal of both grazers caused an increase in sessile invertebrates. The increase was due primarily to clonal ascidians, which displayed a large (∼75%) relative increase in response to the removal of both grazers. However, the observed non-additive responses to grazer removal were temporary and smaller than seasonal fluctuations. Our data demonstrate that urchins and chitons can be redundant in the maintenance of available space, and highlight the value of drawing conclusions from experimental manipulations within an extended temporal context.     

Effect of ionic liquids on the solution structure of human serum albumin

The effect of several ionic liquids (ILs) on the solution structure of human serum albumin (HSA) is revealed by continuous wave electron paramagnetic resonance (EPR) spectroscopy and nanoscale distance measurements with double electron-electron resonance (DEER) spectroscopy. HSA, the most abundant protein in human blood, is able to bind and transport multiple fatty acids (FAs). Using spin-labeled FA, the uptake of the FA by the protein and their spatial distribution in the protein can be monitored. The FA distribution provides an indirect yet effective way to characterize the structure of the protein in solution. Addition of imidazolium-based ILs to an aqueous solution of HSA/FA conjugates is accompanied by significant destabilization and unfolding of the protein's tertiary structure. In contrast, HSA maintains its tertiary structure when choline dihydrogenphosphate (dhp) is added. The comparison of FA distance distributions in HSA with and without choline dhp surprisingly revealed that with this IL, the FA anchoring units are in better agreement with the crystallographic data. Furthermore, the FA entry point distribution appears widened and more asymmetric than in pure buffer. These results indicate that choline dhp as a cosolvent may selectively stabilize HSA conformations closer to the crystal structure out of the overall conformational ensemble.     

Genetic loci associated with plasma phospholipid n-3 fatty acids: a meta-analysis of genome-wide association studies from the CHARGE Consortium

Long-chain n-3 polyunsaturated fatty acids (PUFAs) can derive from diet or from α-linolenic acid (ALA) by elongation and desaturation. We investigated the association of common genetic variation with plasma phospholipid levels of the four major n-3 PUFAs by performing genome-wide association studies in five population-based cohorts comprising 8,866 subjects of European ancestry. Minor alleles of SNPs in FADS1 and FADS2 (desaturases) were associated with higher levels of ALA (p = 3×10⁻⁶⁴) and lower levels of eicosapentaenoic acid (EPA, p = 5×10⁻⁵⁸) and docosapentaenoic acid (DPA, p = 4×10⁻¹⁵⁴). Minor alleles of SNPs in ELOVL2 (elongase) were associated with higher EPA (p = 2×10⁻¹²) and DPA (p = 1×10⁻⁴³) and lower docosahexaenoic acid (DHA, p = 1×10⁻¹⁵). In addition to genes in the n-3 pathway, we identified a novel association of DPA with several SNPs in GCKR (glucokinase regulator, p = 1×10⁻⁸). We observed a weaker association between ALA and EPA among carriers of the minor allele of a representative SNP in FADS2 (rs1535), suggesting a lower rate of ALA-to-EPA conversion in these subjects. In samples of African, Chinese, and Hispanic ancestry, associations of n-3 PUFAs were similar with a representative SNP in FADS1 but less consistent with a representative SNP in ELOVL2. Our findings show that common variation in n-3 metabolic pathway genes and in GCKR influences plasma phospholipid levels of n-3 PUFAs in populations of European ancestry and, for FADS1, in other ancestries.     

Accuracy and cut-off values of pepsinogens I, II and gastrin 17 for diagnosis of gastric fundic atrophy: influence of gastritis

Background

To establish optimal cutoff values for serologic diagnosis of fundic atrophy in a high-risk area for oesophageal squamous cell carcinoma and gastric cancer with high prevalence of Helicobacter pylori (H. pylori) in Northern Iran, we performed an endoscopy-room-based validation study.

Methods

We measured serum pepsinogens I (PGI) and II (PGII), gastrin 17 (G-17), and antibodies against whole H. pylori, or cytotoxin-associated gene A (CagA) antigen among 309 consecutive patients in two major endoscopy clinics in northeastern Iran. Updated Sydney System was used as histology gold standard. Areas under curves (AUCs), optimal cutoff and predictive values were calculated for serum biomarkers against the histology.

Results

309 persons were recruited (mean age: 63.5 years old, 59.5% female). 84.5% were H. pylori positive and 77.5% were CagA positive. 21 fundic atrophy and 101 nonatrophic pangastritis were diagnosed. The best cutoff values in fundic atrophy assessment were calculated at PGI<56 µg/l (sensitivity: 61.9%, specificity: 94.8%) and PGI/PGII ratio<5 (sensitivity: 75.0%, specificity: 91.0%). A serum G-17<2.6 pmol/l or G-17>40 pmol/l was 81% sensitive and 73.3% specific for diagnosing fundic atrophy. At cutoff concentration of 11.8 µg/l, PGII showed 84.2% sensitivity and 45.4% specificity to distinguish nonatrophic pangastritis. Exclusion of nonatrophic pangastritis enhanced diagnostic ability of PGI/PGII ratio (from AUC = 0.66 to 0.90) but did not affect AUC of PGI. After restricting study samples to those with PGII<11.8, the sensitivity of using PGI<56 to define fundic atrophy increased to 83.3% (95%CI 51.6–97.9) and its specificity decreased to 88.8% (95%CI 80.8–94.3).

Conclusions

Among endoscopy clinic patients, PGII is a sensitive marker for extension of nonatrophic gastritis toward the corpus. PGI is a stable biomarker in assessment of fundic atrophy and has similar accuracy to PGI/PGII ratio among populations with prevalent nonatrophic pangastritis.     

Prevalence of accessory deep peroneal nerve in referred patients to an electrodiagnostic medicine clinic

Background

Variations in the branching of posterior cord are important during surgical approaches to the axilla and upper arm, administration of anesthetic blocks, interpreting effects of nervous compressions and in repair of plexus injuries. The patterns of branching show population differences. Data from the African population is scarce.

Objective

To describe the branching pattern of the posterior cord in a Kenyan population.

Materials and methods

Seventy-five brachial plexuses from 68 formalin fixed cadavers were explored by gross dissection. Origin and order of branching of the posterior cord was recorded. Representative photographs were then taken using a digital camera (Sony Cybershot ^R, W200, 7.2 Megapixels).

Results

Only 8 out of 75 (10.7%) posterior cords showed the classical branching pattern. Forty three (57.3%) lower subscapular, 8(10.3%) thoracodorsal and 8(10.3%) upper subscapular nerves came from the axillary nerve instead of directly from posterior cord. A new finding was that in 4(5.3%) and in 3(4%) the medial cutaneous nerves of the arm and forearm respectively originated from the posterior cord in contrast to their usual origin from the medial cord.

Conclusions

Majority of posterior cords in studied population display a wide range of variations. Anesthesiologists administering local anesthetic blocks, clinicians interpreting effects of nerve injuries of the upper limb and surgeons operating in the axilla should be aware of these patterns to avoid inadvertent injury. A wider study of the branching pattern of infraclavicular brachial plexus is recommended.