The polymorphism and haplotype of TLR3 gene in grass carp (Ctenopharyngodon idella) and their associations with susceptibility/resistance to grass carp reovirus

Toll-like receptors (TLRs) have emerged as crucial sensors of invading microbes through recognition of pathogen-associated molecular patterns (PAMPs) in viruses, bacteria, fungi and protozoa. The polymorphisms in TLRs are closely associated with the resistance to pathogen infections. TLR3 involved in the recognition of double stranded RNA in humans, mice, pigs and fishes. In present study, the nucleotide sequence polymorphisms of TLR3 gene in grass carp (Ctenopharyngodon idella) (CiTLR3) were investigated to explore their association with susceptibility/resistance to grass carp reovirus (GCRV). Twelve single nucleotide polymorphisms (SNPs) and an ins/del mutation were detected in the complete sequence of CiTLR3. Ten of them were sited in the non-coding region. The two SNPs in exon were synonymous mutation. The ins/del mutation was coincidental at the start codon. To investigate the association between the polymorphism and the susceptibility/resistance to GCRV, we selected eight SNPs in the non-coding region and analyzed the genotype and allele distribution in susceptible and resistant groups with PCR-RFLP. The statistical results indicated that only ?764 G/T was significantly associated with the resistance of grass carp to GCRV both in genotype (P = 0.040) and allele (P = 0.025). Linkage disequilibrium analysis revealed ?543 A/G, ?488 G/T, 4116 G/T and 4731 C/T were linkage disequilibrium, and haplotype analysis revealed that haplotype GTTT frequency in susceptible group was significantly higher than that in the resistant group (OR = 2.01, 95% CI 0.996–4.043, P = 0.049). To further confirm the correlation, an additional infection experiment was carried out. The mortality in the ?764 GG genotype individuals was significantly lower than GT genotype (OR = 0.208, 95% CI 0.067–0.643, P = 0.011) and TT genotype (OR = 0.183, 95% CI 0.052–0.648, P = 0.015). All the results indicated that haplotype GTTT and genotype ?764 TT and ?764 GT individuals were susceptible to GCRV while ?764 GG was resistant, which could be the optional markers for selective breeding for the GCRV-resistant grass carp in future.     

A novel SNP of the GHRL gene in goat and its association with growth traits

Ghrelin, an endogenous gland for growth hormone secretagogue receptor, has been shown to stimulate food intake and control energy homeostasis and lipid metabolism. So, ghrelin precursor (GHRL) gene is a potential candidate gene for caprine growth traits. In this study, we detected the polymorphism of the caprine GHRL gene by PCR–SSCP and DNA sequencing methods in 459 individuals from four goat breeds. A novel single nucleotide polymorphism (SNP) (IVS2 + 147G > A) was detected. Frequencies of IVS2 + 147G allele varied from 0.842 to 1.000. The association of IVS2 + 147G > A with growth traits was analyzed and IVS2 + 147G > A was shown to be associated with growth traits. Individuals with genotype AG were significantly higher than those of individuals with genotype GG in circumference of chest and cannon and trunk index (P < 0.05 or P < 0.01). Moreover, there was a tendency that genotype AG individuals had better performance in other aspects such as body height and body length than genotype GG individuals although no significant differences appeared (P > 0.05). We suggested that IVS2 + 147G > A could be a perfect molecular marker in marker-assisted selection (MAS).     

Screening for Booroola (FecB) and Galway (FecXG) mutations in Indian sheep

This study reports the status of the Booroola (FecB) and Galway (FecX^G) mutations in Indian sheep breeds. The Kendrapada sheep (n = 46) was genotyped for the presence of FecB and FecX^G mutations, while the Garole (n = 34), Malpura (n = 30), and Decanni sheep (n = 15) for the FecX^G mutation. The FecB and FecX^G genotyping was carried out by forced restriction fragment length polymorphism PCR technique. In the present study, FecB mutation was discovered in the Kendrapada sheep of Orissa, which is now the second prolific sheep of India after the Garole. Out of 46 individuals of Kendrapada sheep, 26 were homozygous (BB), 15 heterozygous (B+) and 5 non-carriers (++) for the FecB mutation. The frequency of the FecB allele in this sample was about 0.73. Results indicated that the frequency of the FecB mutation is high, but the gene is not fixed in the population as reported in Garole sheep. None of sheep breeds carried the FecX^G mutation. The discovery of the FecB mutation in Kendrapada sheep will facilitate the use of FecB allele in improving the prolificacy of non-prolific sheep breeds of India.     

IL6-174 G/C gene polymorphism and its relation to serum IL6 in Egyptian children with community-acquired pneumonia

Cytokines are involved in the pathogenesis of community acquired pneumonia (CAP). The aim of this study is to investigate the association of IL6-174 G/C gene polymorphism with CAP in Egyptian children, to assess its effect on CAP outcome and to determine its effect on the serum IL6 levels in these children.IL6-174 G/C gene polymorphism was genotyped in 210 Egyptian children (100 patients with CAP and 110 healthy controls) using PCR-RFLP, while the serum IL6 levels were measured by ELISA method.We found a significant association between the GG genotype, G allele of IL6-174 G/C SNP and susceptibility to CAP (P = 0.02, 0.01 respectively). However, GG genotype and G allele were protective against severe sepsis (p = 0.004), acute respiratory failure (p < 0.001) and hospital mortality (p < 0.001). Serum IL6 levels were significantly increased in these children while there was no relation between GG genotype and serum IL6.In conclusion, IL6-174 G/C gene polymorphism may contribute to susceptibility to CAP in Egyptian children.     

Association of TP53 codon 72 and CDH1 genetic polymorphisms with colorectal cancer risk in Bangladeshi population

Till now no pharmacogenetic study of TP53 codon 72 (Arg72Pro) and CDH1 rs16260 (-160C<A) genes has been reported on Bangladeshi population relating those with colorectal cancer. So the aim of the study is to determine whether there is an elevated risk of colorectal cancer development with TP53 codon 72 and CDH1 rs16260 genetic polymorphism in Bangladeshi population for the first time. To investigate the association of these two SNPs, we conducted a case-control study with 288 colorectal cancer patients and 295 healthy volunteers by using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. We found an increased risk of association between Arg/Pro heterozygosity (adjusted OR = 2.58, 95% CI = 1.77–3.77, p < 0.05) and Pro/Pro mutant homozygosity (adjusted OR = 2.92, 95% CI = 1.78–4.78, p < 0.05) along with the combined genotype (Arg/Pro + Pro/Pro) (adjusted OR = 2.70, 95% CI = 1.90–3.82, p < 0.05) and colorectal cancer predisposition. In case of CDH1 rs16260 polymorphism, C/A heterozygous and A/A mutant homozygous are significantly (p < 0.05) found to be associated with colorectal cancer risk with adjusted OR of 1.94 and 2.63, respectively. The combined genotype of C/A and A/A was also found to be strongly associated with colorectal cancer risk compared to C/C genotype (adjusted OR = 2.02, 95% CI = 1.42–2.87, p < 0.05). In conclusion, heterozygosity and mutant homozygosity as well as the combination of both TP53 Arg72Pro and CDH1 rs16260 polymorphisms are responsible to increase the risk of colorectal cancer development in Bangladeshi population.     

Kinetics of cellulose hydrolysis by halostable cellulase from a marine Aspergillus niger at different salinities

Kinetics of cellulose hydrolysis with halostable cellulase from a marine Aspergillus niger was analyzed at different salinities. Cellulase activity in 8% NaCl solution was 1.43 folds higher than that in NaCl free solution. Half saturation constant, K_m (15.6260 g/L) and the rate constant of deactivation, K_de (0.3369 g/L h) in 8% NaCl solution was lower than that (18.6364 g/L), 0.3754 (g/L h) in NaCl free solution. The maximum initial hydrolysis velocity, V_max (25.5295 g/L h), in 8% NaCl solution was higher than that in NaCl free solution (25.0153 g/L h). High salinity increased affinity to the cellulase to the substrate and thermostability. Halostable cellulase from a marine Aspergillus niger was valuable for cellulose hydrolysis under high salinity conditions.     

Ligand-based CoMFA and CoMSIA studies on chromone derivatives as radical scavengers

The antioxidant activity for a series of chromone compounds, evaluated by DPPH free radical scavenging assay, were subjected to 3D-QSAR studies using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). All 48 chromone derivatives were geometry optimized by AM1 and HF/6-31G^* calculations. The CoMFA and CoMSIA results were compared between different alignment strategies. The best CoMFA model obtained from HF/6-31G^* optimization with field fit alignment gave cross-validated r² (q²) = 0.821, noncross-validated r² = 0.987, S = 0.095, and F = 388.255. The best CoMSIA model derived from AM1 optimized structures and superimposition alignment gave q² = 0.876, noncross-validated r² = 0.976, S = 0.129, and F = 208.073, including electrostatic, hydrophobic, hydrogen bond donor and acceptor fields. The contour maps provide the fruitful structure–radical scavenging activity relationships which are useful for designing new compounds with higher activity.     

Stomatal,biochemical and morphological factors limiting photosynthetic gas exchange in the mangrove associate Hibiscus tiliaceus under saline and arid environment

The effect of salinity on leaf area and the relative accumulation of Na⁺ and K⁺ in leaves of the mangrove associate Hibiscus tiliaceus were investigated. Photosynthetic gas exchange characteristics were also examined under arid and non-arid leaf conditions at 0, 10, 20 and 30‰ substrate salinity. At salinities ≥ 40‰, plants showed complete defoliation followed by 100% mortality within 1 week. Salinities ≤ 30‰ were negatively correlated with the total leaf area per plant (r² = 0.94). The reduction in the total plant leaf area is attributed to the reduction in the area of individual leaves (r² = 0.94). Selective uptake of K⁺ over Na⁺ declined sharply with increasing salinity, where K⁺/Na⁺ ratio was reduced from 6.37 to 0.69 in plants treated with 0 and 30‰, respectively. Under non-arid leaf condition, increasing salinity from 0 to 30‰ has significantly reduced the values of the intrinsic components of photosynthesis V_c,max (from 50.4 to 18.4 μmol m⁻² s^-1), J_max (from 118.0 to 33.8 μmol photons m⁻² s⁻¹), and V_TPU (from 6.90 to 2.30 μmol m⁻² s⁻¹), while stomatal limitation to gas phase conductance (S_L) increased from 14.6 to 38.4%. Water use efficiency (WUE) has subsequently doubled from 3.20 for the control plants to 8.93 for 30‰ treatment. Under arid leaf conditions, the stomatal factor (S_L) was more limiting to photosynthesis than its biochemical components (73.4 to 26.6%, respectively, at 30‰). It is concluded that salinity causes a drastic decline in photosynthetic gas exchange in H. tiliaceus leaves through its intrinsic and stomatal components, and that the apparent phenotypic plasticity represented by the leaf area modulation is unlikely to be the mechanism by which H. tiliaceus avoids salt stress.     

HapMap-based study identifies risk sub-region on chromosome 19q13.3 in relation to lung cancer among Chinese

Background: Chromosome 19q13.3 has been identified as one of the regions that associate with cancer risk in previous studies. Methods: We systematically examined the 70.772 kb region comprising four genes on chromosome 19q13.3 among Chinese using the haplotype-tagging SNP (htSNP) approach and the HapMap platform. The study involved 339 lung cancer cases and 358 non-cancer controls. Two htSNPs (rs1046282 and rs735482) captured most of the common haplotypes of CD3EA and the combined effects of sixteen htSNPs provided high coverage of common haplotypes of ERCC2, PPP1R13L, CD3EAP and ERCC1. Results: Both carriers of variant CC genotype [adjusted OR (95% CI) = 1.28 (1.02–1.60), P = 0.04] and variant C-allele among >20 years’ smokers [OR (95% CI) = 2.13 (1.24–3.67), P = 0.006] for CD3EAP rs735482 were at increased risk of lung cancer. Four haplotype blocks of strong linkage disequilibrium were identified. The haplotype ERCC2 rs3916874^G and rs238415^C [OR (95% CI) = 1.26 (1.02–1.57), P = 0.03] in block 1 and the haplotype PPP1R13L rs4803817^A, CD3EAP rs1046282^T, rs735482^C, ERCC1 rs3212980^A, rs3212964^G [OR (95% CI) = 3.56 (1.55–8.18), P = 0.005] in block 3 were associated with lung cancer risk. MDR (multifactor dimensionality reduction) analysis demonstrated the best significant model of two-attributes containing smoking duration and rs2298881 in ERCC1 (P = 0.004–0.005) and suggested that the effects of high-order interactions among smoking duration and ERCC2, PPP1R13, ERCC1 htSNPs could modulate lung cancer risk. Conclusions: HapMap-based study of 19q13.3 identified that genetic variation of CD3EAP and two loci were associated with lung cancer risk and interaction of smoking duration and genetic variants was the strongest predictor of lung cancer risk in a Chinese population.     

Stomatal,biochemical and morphological factors limiting photosynthetic gas exchange in the mangrove associate Hibiscus tiliaceus under saline and arid environment

The effect of salinity on leaf area and the relative accumulation of Na⁺ and K⁺ in leaves of the mangrove associate Hibiscus tiliaceus were investigated. Photosynthetic gas exchange characteristics were also examined under arid and non-arid leaf conditions at 0, 10, 20 and 30‰ substrate salinity. At salinities ≥ 40‰, plants showed complete defoliation followed by 100% mortality within 1 week. Salinities ≤ 30‰ were negatively correlated with the total leaf area per plant (r² = 0.94). The reduction in the total plant leaf area is attributed to the reduction in the area of individual leaves (r² = 0.94). Selective uptake of K⁺ over Na⁺ declined sharply with increasing salinity, where K⁺/Na⁺ ratio was reduced from 6.37 to 0.69 in plants treated with 0 and 30‰, respectively. Under non-arid leaf condition, increasing salinity from 0 to 30‰ has significantly reduced the values of the intrinsic components of photosynthesis V_c,max (from 50.4 to 18.4 μmol m⁻² s^-1), J_max (from 118.0 to 33.8 μmol photons m⁻² s⁻¹), and V_TPU (from 6.90 to 2.30 μmol m⁻² s⁻¹), while stomatal limitation to gas phase conductance (S_L) increased from 14.6 to 38.4%. Water use efficiency (WUE) has subsequently doubled from 3.20 for the control plants to 8.93 for 30‰ treatment. Under arid leaf conditions, the stomatal factor (S_L) was more limiting to photosynthesis than its biochemical components (73.4 to 26.6%, respectively, at 30‰). It is concluded that salinity causes a drastic decline in photosynthetic gas exchange in H. tiliaceus leaves through its intrinsic and stomatal components, and that the apparent phenotypic plasticity represented by the leaf area modulation is unlikely to be the mechanism by which H. tiliaceus avoids salt stress.     

Monitoring of carbamate and organophosphate resistance levels in Nilaparvata lugens based on bioassay and quantitative sequencing

The resistance levels to carbamate (CB) and organophosphate (OP) insecticides were determined by topical application in 14 field strains of Nilaparvata lugens. The resistance levels of N. lugens to CB and OP were 1.3–47.5-fold and 1.4–14.4-fold higher than a susceptible strain, respectively. A quantitative sequencing (QS) protocol was established to determine the allele frequencies of four acetylcholinesterase point mutations putatively associated with CB and OP resistance. The allele frequencies of the four mutations (G119A, F/Y330S, F331H and I332L) in field strains' ranges are ca. 0.0–51.7%, 0.0–88.9%, 5.1–56.0% and 6.7–57.3%, respectively. The F331H and I332L were tightly linked to each other, suggesting that these mutations may occur simultaneously. In correlation analysis, G119A was not well correlated with actual resistance levels (r² = < 0.232), whereas F331H and I332L showed a better correlation with the resistance levels of benzofuranyl methylcarbamates (r² = 0.595). This finding indicates that F331H and I332L mutation frequencies may be used as molecular markers for detecting carbamate resistance in N. lugens. A QS protocol detecting the F331H and I332L mutation frequencies could therefore be employed as a supportive tool for the rapid monitoring of CB insecticide resistance levels in N. lugens.     

Growth of the fungus Paecilomyces lilacinus with n-hexadecane in submerged and solid-state cultures and recovery of hydrophobin proteins

The filamentous fungus Paecilomyces lilacinus was grown on n-hexadecane in submerged (SmC) and solid-state (SSC) cultures. The maximum CO₂ production rate in SmC (V_max = 11.7 mg CO₂ L_g⁻¹ day⁻¹) was three times lower than in SSC (V_max = 40.4 mg CO₂ L_g⁻¹ day⁻¹). The P. lilacinus hydrophobin (PLHYD) yield from the SSC was 1.3 mg PLHYD g protein⁻¹, but in SmC, this protein was not detected. The PLHYD showed a critical micelle concentration of 0.45 mg mL⁻¹. In addition, the PLHYD modified the hydrophobicity of Teflon from 130.1 ± 2° to 47 ± 2°, forming porous structures with some filaments <1 μm and globular aggregates <0.25 μm diameter. The interfacial studies of this PLHYD could be the basis for the use of the protein to modify surfaces and to stabilize compounds in emulsions.     

Forming nanoparticles of α-amylase and embedding them into solid surfaces

In the current work nanoparticles (NPs) of α-amylase were generated in an aqueous solution using high-intensity ultrasound, and were subsequently immobilized on polyethylene (PE) films, or polycarbonate (PC) plates, or on microscope glass slides. The α-amylase NPs coated on the solid surfaces have been characterized by ESEM, TEM, FTIR, XPS and AFM. The substrates immobilized with α-amylase were used for hydrolyzing soluble potato starch to maltose. The amount of enzyme introduced in the substrates, leaching properties, and the catalytic activity of the immobilized enzyme were compared. The catalytic activity of the amylase deposited on the three solid surfaces was compared to that of the same amount of free enzyme at different pHs and temperatures. α-Amylase coated on PE showed the best catalytic activity in all the examined parameters when compared to native amylase, especially at high temperatures. When immobilized on glass, α-amylase showed better activity than the native enzyme over all pH and temperature values studied. However, the immobilization on PC did not improve the enzyme activity at any pH and any temperature compared to the free amylase. The kinetic parameters, K_m and V_max were also calculated. The amylase coated PE showed the most favorable kinetic parameters (K_m = 5 g L⁻¹ and V_max = 5E−07 mol mL⁻¹ min⁻¹). In contrast, the anchored enzyme-PC exhibited unfavorable kinetic parameters (K_m = 16 g L⁻¹, V_max = 4.2E−07 mol mL⁻¹ min⁻¹). The corresponding values for amylase-glass were K_m = 7 g L⁻¹, V_max = 1.8E−07 mol mL⁻¹ min⁻¹, relative to those obtained for the free enzyme (K_m = 6.6 g L⁻¹, V_max = 3.3E−07 mol mL⁻¹ min⁻¹).     

Development of a microfluidic device for determination of cell osmotic behavior and membrane transport properties

An understanding of cell osmotic behavior and membrane transport properties is indispensable for cryobiology research and development of cell-type-specific, optimal cryopreservation conditions. A microfluidic perfusion system is developed here to measure the kinetic changes of cell volume under various extracellular conditions, in order to determine cell osmotic behavior and membrane transport properties. The system is fabricated using soft lithography and is comprised of microfluidic channels and a perfusion chamber for trapping cells. During experiments, rat basophilic leukemia (RBL-1 line) cells were injected into the inlet of the device, allowed to flow downstream, and were trapped within a perfusion chamber. The fluid continues to flow to the outlet due to suction produced by a Hamilton Syringe. Two sets of experiments have been performed: the cells were perfused by (1) hypertonic solutions with different concentrations of non-permeating solutes and (2) solutions containing a permeating cryoprotective agent (CPA), dimethylsulfoxide (Me₂SO), plus non-permeating solute (sodium chloride (NaCl)), respectively. From experiment (1), cell osmotically inactive volume (V_b) and the permeability coefficient of water (L_p) for RBL cells are determined to be 41% [n = 18, correlation coefficient (r²) of 0.903] of original/isotonic volume, and 0.32 ± 0.05 μm/min/atm (n = 8, r² > 0.963), respectively, for room temperature (22 °C). From experiment (2), the permeability coefficient of water (L_p) and of Me₂SO (P_s) for RBL cells are 0.38 ± 0.09 μm/min/atm and (0.49 ± 0.13) × 10⁻³ cm/min (n = 5, r² > 0.86), respectively. We conclude that this device enables us to: (1) readily monitor the changes of extracellular conditions by perfusing single or a group of cells with prepared media; (2) confine cells (or a cell) within a monolayer chamber, which prevents imaging ambiguity, such as cells overlapping or moving out of the focus plane; (3) study individual cell osmotic response and determine cell membrane transport properties; and (4) reduce labor requirements for its disposability and ensure low manufacturing costs.     

Soluble receptor for advanced glycation end products as a potential biomarker to predict weight loss and improvement of insulin sensitivity by a very low calorie diet of obese human subjects

IntroductionObesity is associated with low-grade systemic inflammation which is thought to trigger the development of comorbidities such as type 2 diabetes. The soluble receptor for advanced glycation end products (sRAGE) belongs to the innate immune system and has been linked to obesity, recently. The aim of the present study was to examine whether serum sRAGE concentrations are related to the grade of weight loss and improvement of insulin resistance due to a very low calorie diet (VLCD).Methods22 severe obese subjects (Median Body Mass Index (BMI): 44.5 kg/m²) were included in a dietary intervention study of 6 month, consisting of a very low calorie formula diet phase (VLCD: 800 kcal/d) for 12 weeks and a following 12 week weight maintenance phase. Fasting glucose, fasting insulin, adiponectin, leptin and sRAGE were determined from sera. Insulin sensitivity was estimated by Homeostasis Model Assessment (HOMA) index and leptin-to-adiponectin-ratio (LAR).ResultsMean body weight reduction by VLCD accounted to 21.7 kg with a significant improvement of insulin resistance. At baseline, sRAGE serum levels were significantly inversely related to BMI (r_S = −0.642, p = 0.001) and HOMA (r_S = −0.419, p = 0.041). Of interest, sRAGE serum levels at baseline were significantly lower in study subjects with greater reduction of BMI (p = 0.017). In addition, a significantly greater HOMA reduction was observed in subjects with lower sRAGE serum levels at baseline (p = 0.006). Finally, correlation analysis revealed, that changes of sRAGE serum levels were significantly correlated to changes of BMI (r_S = −0.650, p = 0.022) during intervention.ConclusionAnti-inflammatory sRAGE might be a potential future biomarker to predict weight loss and improvement of insulin resistance by a VLCD whereby lower baseline sRAGE serum levels indicate a better outcome of the dietary intervention.     

Supplementation of ammonium bicarbonates for the treatment of fruit cordial wastewater by anaerobic digestion process

Lack of nitrogenous substrate and buffering capacity have been identified as causing failure in previous work on the treatment of fruit cordial wastewater using anaerobic continuous stirred tank reactors. In this study, ammonium bicarbonate was proposed to be used as the substrate for nitrogenous and buffering resources. In order to determine the toxicity effect of the ammonium salts on the anaerobic system, a series of concentration from 0 to 40 mg L^?1 was tested. Biogas production was used as the indicator for NH₄⁺ toxicity. The results showed no indication that methanogen was affected by the additional ammonium salt within the dosing regime. Application of the specific mathematical function (G = G_m^k/t) to describe the kinetic of biogas production, suggested that the optimal concentration of ammonium bicarbonate that can be used is 10 mg L^?1. This study also shows that the dosage regime up to 40 mg L^?1 can be used to supplement the lack of nitrogenous and buffering capacity for the anaerobic digestion process of the fruit cordial wastewater using CSTR.     

Pharmacological evaluation of R(+)-pulegone on cardiac excitability: Role of potassium current blockage and control of action potential waveform

IntroductionR(+)-pulegone is a ketone monoterpene and it is the main constituent of essential oils in several plants. Previous studies provided some evidence that R(+)-pulegone may act on isolated cardiac myocytes. In this study, we evaluated in extended detail, the pharmacological effects of R(+)-pulegone on cardiac tissue.MethodsUsing in vivo measurements of rat cardiac electrocardiogram (ECG) and patch-clamp technique in isolated myocytes we determinate the influence of R(+)-pulegone on cardiac excitability.ResultsR(+)-pulegone delayed action potential repolarization (APR) in a concentration-dependent manner (EC₅₀ = 775.7 ± 1.48, 325.0 ± 1.30, 469.3 ± 1.91 μM at 10, 50 and 90% of APR respectively). In line with prolongation of APR R(+)-pulegone, in a concentration-dependent manner, blocked distinct potassium current components (transient outward potassium current (I_to), rapid delayed rectifier potassium current (I_Kr), inactivating steady state potassium current (I_ss) and inward rectifier potassium current (I_K1)) (EC₅₀ = 1441 ± 1.04; 605.0 ± 1.22, 818.7 ± 1.22; 1753 ± 1.09 μM for I_to, I_Kr, I_ss and I_K1, respectively). The inhibition occurred in a fast and reversible way, without changing the steady-state activation curve, but instead shifting to the left the steady-state inactivation curve (V_1/2 from −56.92 ± 0.35 to −67.52 ± 0.19 mV). In vivo infusion of 100 mg/kg R(+)-pulegone prolonged the QTc (∼40%) and PR (∼62%) interval along with reducing the heart rate by ∼26%.ConclusionTaken together, R(+)-pulegone prolongs the APR by inhibiting several cardiomyocyte K⁺ current components in a concentration-dependent manner. This occurs through a direct block by R(+)-pulegone of the channel pore, followed by a left shift on the steady state inactivation curve. Finally, R(+)-pulegone induced changes in some aspects of the ECG profile, which are in agreement with its effects on potassium channels of isolated cardiomyocytes.     

Plants as bioindicator for temperature interpolation purposes: Analyzing spatial correlation between botany based index of thermophily and integrated temperature characteristics

The success of interpolation techniques relies heavily on the density and regularity of field reference data points. For instance temperature interpolations in the Arctic are hampered by few and scattered meteorological stations. The major objective of this study is to analyze the spatial relationship between plants, defined in terms of an index of thermophily (I_t) and temperature distribution. The study area is located in Kongsfjorden, northwest Spitsbergen (Svalbard). A systematic recording of floristic data covering the study area was made within quadrates of 1 km × 1 km (93 units). For each of them, the I_t was calculated. I_t provides a synthetic measure by which plants are taken as temperature indicators at a long time scale. Temperature values were recorded by means of 39 temperature loggers during the summer 2000. The model for spatial interpolation of temperature was developed using multiple regression of remote sensed data (Landsat TM) and topographical features derived from a digital elevation model (DEM). Continuous temperature layers were calculated at a spatial resolution of 50 m × 50 m, and aggregated to a resolution of 1 km × 1 km in order to correspond with the observed botanical units. Different maps were produced showing spatial distribution of the modelled temperature and I_t. Correlations between the I_t and temperature values derived from the modelled temperature layers were systematically explored. Correlation between the I_t and temperatures works well as standard deviation of residues is 0.7 °C only. Highest correlations (r) of I_t and the spatial distribution of temperature were obtained for: (a) maximum average temperature for August, excluding all areas higher than 100 m above sea level (0.75), (b) average daily maximum temperature for July–October (0.67), (c) average temperature for July and August (0.64, 0.65), and (d) when temperature range is >8 °C (0.55). Areas with low correlations between I_t and temperature were mainly attributed to the fact that these measurements represent (a) different time scales and (b) different spatial scales. However, results from this study have shown that calculating I_t provide a mean for restoring selected temperature parameters and thus can contribute to fill in and extend the network of field data points for temperature interpolation purposes.     

Genetic polymorphisms in the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene and prostate cancer risk in Caucasian men

Background: Catechol-estrogen metabolites can induce carcinogenesis by acting as endogenous tumor initiators. Glucuronidation, mediated by the UDP-glucuronosyltransferase 1A1 (UGT1A1) enzyme, is a main metabolic pathway of estrogen detoxification in steroid target tissues, such as the prostate. The aim of our study was to investigate the possible correlation between UGT1A1 promoter gene polymorphisms and prostate cancer risk. Patients and methods: 129 patients with prostate cancer and 260 healthy controls were included in our study. A(TA)TAA promoter polymorphism of UGT1A1 gene was studied using the Fragment Analysis Software of an automated DNA sequencer and three genotypes (homozygous 7/7, heterozygous 6/7 and normal homozygous 6/6) were identified. Results: No significant differences were observed between the cancer group and controls regarding the genotyping distribution of the three UGT1A1 promoter genotypes (P > 0.05). Also, no association was found between overall disease risk and the presence of the polymorphic homozygous genotype (TA(7)/TA(7) vs TA(6)/TA(7) + TA(6)/TA(6)) (P = 0.18). In addition, no association was revealed between UGT1A1 genotype distribution and Gleason score (P = 0.55). Conclusion: Our data suggest that the TA repeat polymorphism of UGT1A1 gene does not seem to alter prostate cancer risk susceptibility in Caucasian men.