Light acclimation of photosynthesis in three charophyte species

The main aim of this study was to investigate if the charophyte species Chara baltica, Chara canescens (two populations from the Baltic Sea (BS) and the Gulf of Korinth, Greece (GK)), and Lamprothamnium papulosum exhibit different acclimation capacities to irradiance. Growth, photosynthesis and pigment content were examined in the laboratory under six irradiance conditions (35–500 μmol photons m⁻² s⁻¹). Growth experiments showed increasing growth rates from 35 μmol photons m⁻² s⁻¹ (∼10 mg fresh weight (FW)) up to 70 μmol photons m⁻² s⁻¹ (∼20 mg FW) in C. baltica, from 35 μmol photons m⁻² s⁻¹ (∼15 mg FW) up to 380 μmol photons m⁻² s⁻¹ (∼145 mg FW) in C. canescens (BS), and up to the highest growth irradiance in algae of L. papulosum (35 μmol: ∼5 mg FW; 500 μmol: ∼20 mg FW). The species were tested for their ability to acclimate to different growth irradiances (E_g) by calculating P_max (maximum photosynthesis rate at saturating irradiances), α (the efficiency of light utilization at limiting irradiance), and E_k (the light saturation point of photosynthesis, P_max/α). All species exhibited increasing P_max with increasing E_g. Whereas both populations of C. canescens increased α with increasing E_g, L. papulosum and C. baltica did not acclimate α at all. E_k, the irradiance at which photosynthesis ceased to be light-limited, was constant for all Chara species within the range of irradiances tested. Chl a/Chl b ratios of all species were constant over the whole range of E_g. Chl a/carotenoid ratios were constant in C. baltica, whereas Chl a/carotenoid ratios in L. papulosum and C. canescens (BS) decreased from 250 and 70 μmol photons m⁻² s⁻¹ upwards, respectively. Pigmentation analysis showed that Chl a/carotenoid acclimation was mainly caused by species-specific capacity to raise the content of lutein and carotene (C. canescens (BS), C. canescens (GK)) and xanthophyll cycle pigments (XCP; L. papulosum). The non-photochemical quenching (NPQ) capacities of L. papulosum, C. canescens (BS), and C. canescens (GK) were dependent from preacclimation status of algae, whereas NPQ of C. baltica was independent from growth irradiance.Our results indicate that C. baltica and C. canescens (BS) were light saturated within the chosen irradiances, whereas C. canescens (GK) and L. papulosum did not reach their limits of high-light acclimation. The photosynthetic pigments lutein, α- and β-carotene are suggested to act as photo-protective pigments in L. papulosum and C. canescens.     

Sex-specific light acclimation of Chara canescens (Charophyta)

Bisexual populations of the charophyte Chara canescens (Desv. et Loisel. in Loisel., 1810) containing male and female individuals are rarely found. Two experiments were carried out to study whether male and female algae from the same site exhibit different physiological capacities, especially with respect to light acclimation.Algae from two different shore levels and from laboratory cultures acclimated to six irradiance conditions (35–500 μmol photons m⁻² s⁻¹) were compared. Field measurements showed that both female and male algae of C. canescens are able to acclimate to daily changes in solar irradiance. The quantum yield of Photosystem II (PSII) decreased with increasing irradiance in the morning and increased with decreasing irradiance in the afternoon. Growth experiments showed increasing growth rates from 35 μmol photons m⁻² s⁻¹ (∼7 mg FW) up to 500 μmol photons m⁻² s⁻¹ (∼27 mg FW) in female and male C. canescens. The irradiance saturation point for photosynthesis (E_k) was about 140 μmol m⁻² s⁻¹ for both sexes within the whole range of acclimation irradiances. The maximum photosynthesis rate at saturating irradiances (P_max) of male algae was highest at E_k, whereas P_max of female algae was highest at 500 μmol photons m⁻² s⁻¹. The photosynthetic efficiency in the light-limited range (α) increased in female C. canescens and decreased in male C. canescens. The ratio of the non-photochemical quenching parameter (NPQ) to the relative electron transport rates rETR_(MT) increased in both sexes with irradiance, but showed a steeper increase in male than in female algae. Pigment analysis showed similar acclimation pattern for male and female C. canescens. Chl a/Chl b ratios of both sexes were constant over the whole range of E_g, whereas Chl a/carotenoid ratios in male and female C. canescens decreased from 70 μmol photons m⁻² s⁻¹ upwards. Pigment analysis pointed out that the carotenes α-, β- and γ-carotene were more prominent in male than in female algae.Our results indicate that female C. canescens are more efficient in light acclimation than male algae from the same site. Nevertheless, further investigations of bisexual C. canescens populations resolving CO₂-uptake mechanisms and/or genetic differences are needed.     

A novel biotransformation of astragalosides to astragaloside IV with the deacetylation of fungal endophyte Penicillium canescens

Under the deacetylation of fungal endophyte Penicillium canescens, which was isolated from pigeon pea, a novel and highly efficient biotransformation method of astragalosides to astragaloside IV in Radix Astragali was investigated. After single factor tests of the biotransformation procedure, the optimum biotransformation conditions were confirmed as the liquid solid ratio 20:1, the biotransformation temperature 30 °C, time 36 h and pH 7, respectively. Final content of astragaloside IV in Radix Astragali reached 7.66 ± 0.44 mg/g, which was 5.51-fold to that of untreated one and contents of astragaloside I and astragaloside II significantly decreased. The immobilized Ca-alginate gel beads with P. canescens could be reused at least for 13 runs. This is the first report that fungal endophyte was applied for the biotransformation of astragalosides to astragaloside IV in Radix Astragali and this novel high-efficiency biotransformation method will be an alternative to enhance the content of astragaloside IV in Radix Astragali in commercial process.     

Biocontrol of major postharvest pathogens on apple using Rhodotorula glutinis and its effects on postharvest quality parameters

The biocontrol activity of Rhodotorula glutinis on gray mold decay and blue mold decay of apple caused by Botrytis cinerea and Penicillium expansum, respectively, was investigated, as well as its effects on postharvest quality of apple fruits. The results show there was a significant negative correlation between concentrations of the yeast cells and the disease incidence of the pathogens. The higher concentration of the R. glutinis, the better effect of the biocontrol capacity. At concentrations of R. glutinis 1 × 10⁸ CFU ml^?1, the amount of gray mold decay was completely inhibited after 5 days incubation at 20 °C, after challenge with B. cinerea spores suspension of 1 × 10⁵ spores ml^?1; While the blue mold decay was completely inhibited at concentrations of 5 × 10⁸ CFU ml^?1, at challenged with P. expansum spores suspension of 5 × 10⁴ spores ml^?1_. These results demonstrated that the efficacy of R. glutinis in controlling of gray mold decay of apples was better than the efficacy of controlling blue mold. R. glutinis within inoculated wounds on apples increased in numbers at 20 °C from an initial level of 9.5 × 10⁵ CFU per wound to 2.24 × 10⁷ CFU at 20 °C after 1 day. The highest population of the yeast was recovered 4 days after inoculation, the yeast population in wounds increased by 56.9 times. After that, the population of the yeast began to decline very slowly. R. glutinis significantly reduced the incidence of natural infections on intact fruit from 75% in the control fruit to 28.3% after 5 days at 20 °C, and from 58.3 to 6.7% after 30 days at 4 °C followed by 4 days at 20 °C. R. glutinis treatment had no deleterious effect on quality parameters after 5 days at 20 °C or after 30 days at 4 °C followed by 4 days at 20 °C.     

ACTN3 Gene R577X Polymorphism Associated with High-Density Lipoprotein Cholesterol and Adiponectin in Rugby Players

Objective: To determine the relationship between the R577X polymorphism of the α-actinin-3 (ACTN3), which may play a role in the individual differences observed in the effects of exercise on health benefits and antiatherogenic markers (i.e., high-density lipoprotein cholesterol [HDL-C] and adiponectin) in athletes.Methods: Seventy-six male rugby players (mean age 19.8 years) were enrolled in this study. Genomic DNA was extracted from peripheral blood samples, and restriction fragment length polymorphism-polymerase chain reactions were conducted to assess ACTN3 genotypes. Body mass index (BMI), waist circumference, serum lipids including HDL-C, and adiponectin levels were measured. Current smoking and alcohol intake habits were evaluated with a questionnaire. All of the parameters were compared between 2 groups displaying frequently observed genotypes: one group consisting of patients having either the R/R or R/X genotype and a second group with the X/X genotype.Results: The frequency of the X allele was 0.55 and the distribution of the genotypes was 35.5% (n = 27) for X/X, 39.5% (n = 30) for R/X, and 25.0% (n = 19) for R/R. Serum HDL-C and adiponectin levels were significantly higher in X/X genotype compared to the R/R or R/X genotype (HDL-C 1.6 ± 0.3 [SD] vs. 1.4 ± 0.2 mmol/L; P<.01, adiponectin 8.8 ± 2.6 vs. 6.9 ± 2.3 μg/mL; P<.01), even after adjustments for confounders (P<.01).Conclusion: There may be a relationship between the ACTN3 genotype and HDL-C and adiponectin levels in rugby players. This may be useful information when determining the individual responses of antiatherogenic markers to exercise.Abbreviations:ACTN3 = α-actinin-3BMI = body mass indexCVD = cardiovascular diseaseHDL-C = high-density lipoprotein cholesterolLDL-C = low-density lipoprotein cholesterolR = arginine (R) at amino acid position 577 of the ACTN3 proteinTC = total cholesterolTG = triglycerideX = truncation at amino acid position 577 of the ACTN3 protein     

The synthesis of cholestane and furostan saponin analogues and the determination of sapogenin's absolute configuration at C-22

A facile and efficient way for the synthesis of cholestane and furostan saponin analogues was established and adopted for the first time. Following this strategy, starting from diosgenin, three novel cholestane saponin analogues: (22S,25R)-3β,22,26-trihydroxy-cholest-5-ene-16-one 22-O-[O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside] 11, (25R)-3β,16β,26-trihydroxy-cholest-5-ene-22-one 16-O-[O-α-l-rhamnopyranosyl-(1 → 2)-α-d-glucopyranoside] 14 and (25R)-3β,16β,26-trihydroxy-cholest-5-ene-22-one 16-O-[O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside] 17, three novel furostan saponin analogues: (22S,25R)-furost-5-ene-3β,22,26-triol 22-O-(α-d-glucopyranoside) 23, (22R,25R)-furost-5-ene-3β,22,26-triol 22-O-(α-d-glucopyranoside) 24 and (22S,25R)-furost-5-ene-3β,22,26-triol 22-O-[O-α-l-rhamnopyranosyl-(1 → 2)-α-d-glucopyranoside] 26, were synthesized ultimately. The structures of all the synthesized analogues were confirmed by spectroscopic methods. The S-chirality at C-22 of cholestane was confirmed by Mosher's method. The absolute configuration at C-22 of furostan saponin analogues was distinguished by conformational analysis combined with the NMR spectroscopy. The cytotoxicities of the synthetic analogues toward four types of tumor cells were shown also.     

Insulin-like growth factor axis gene polymorphisms modify risk of pancreatic cancer

Objective: Insulin-like growth factor (IGF)-axis genes plays a critical role in cancer development and progression via their impact on the RAS/MAPK/ERK and PI3 K/AKT/mTOR signaling pathways. We hypothesized that IGF-axis genetic variants modify individual susceptibility to pancreatic cancer. Methods: We retrospectively genotyped 41 single-nucleotide polymorphisms of 10 IGF-axis genes (IGF1, IGF2, IGF1R, IGF2R, IGFBP1, IGFBP3, IGFBP5, IRS1, IRS2, and IRS4) in 706 pancreatic cancer patients and 706 cancer-free controls using Sequenom and TaqMan technology. The association between genotype and pancreatic cancer risk was evaluated using multivariate logistic regression. A P value ≤.007 at a false discovery rate of 10% was set as the significance level. Results: We observed that the IGF1 *10212C>A and Ex4+2776G>A and IGF1R IVS2?70184A>G and IVS2+46329T>C variant genotypes were significantly associated with decreased pancreatic cancer risk (odds ratio [OR] range, 0.60–0.75) and that IGFBP1 Ex4+111A>G (I253M) was significantly associated with increased pancreatic cancer risk (OR = 1.46) after adjusted for other risk factors and multiple comparisons (P ≤ .007). IGF2R and IGFBP3 variant haplotypes were associated with increased and decreased pancreatic cancer risk, respectively (P < .001). We also observed a weak interaction of the IGF1R IVS2+46329T>C and IGF2R Ex45+11C>T (L2222L) genotypes with diabetes (P_interaction = .05) and interaction of IGF2R and IRS1 genotypes with alcohol consumption (P_interaction = .03 and .019, respectively) on increased pancreatic cancer risk. Conclusion: These findings support our hypothesis that polymorphic variants of IGF-axis genes act alone or jointly with other risk factors to affect susceptibility to pancreatic cancer.     

Impact of fluctuating temperatures on development of the koinobiont endoparasitoid Venturia canescens

The effect of temperature on the biology of Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae) is well understood under constant temperature conditions, but less so under more natural, fluctuating conditions. Herein we studied the influence of fluctuating temperatures on biological parameters of V. canescens. Parasitized fifth-instar larvae of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) were reared individually in incubators at six fluctuating temperature regimes (15–19.5 °C with a mean of 17.6 °C, 17.5–22.5 °C with a mean of 19.8 °C, 20–30 °C with a mean of 22.7 °C, 22.5–27.5 °C with a mean of 25 °C, 25.5-32.5 °C with a mean of 28.3 °C and 28.5–33 °C with a mean of 30 °C) until emergence and death of V. canescens adults. Developmental time from parasitism to adult eclosion, adult longevity and survival were recorded at each fluctuating temperature regime. In principle, developmental time decreased with an increase of the mean temperature of the fluctuating temperature regime. Upper and lower threshold temperatures for total development were estimated at 34.9 and 6.7 °C, respectively. Optimum temperature for development and thermal constant were 28.6 °C and 526.3 degree days, respectively. Adult longevity was also affected by fluctuating temperature, as it was significantly reduced at the highest mean temperature (7.0 days at 30 °C) compared to the lowest one (29.4 days at 17.6 °C). Survival was low at all tested fluctuating temperatures, apart from mean fluctuating temperature of 25 °C (37%). Understanding the thermal biology of V. canescens under more natural conditions is of critical importance in applied contexts. Thus, predictions of biological responses to fluctuating temperatures may be used in population forecasting models which potentially influence decision-making in IPM programs.     

The novel allele (3R) of the VNTR polymorphism in the XRCC5 promoter region dramatically decreases the gene expression

Polymorphism of variable number of tandem repeats (VNTR) in the promoter region of X-ray repair cross-complementing 5 (MIM: 194364, XRCC5; rs6147172) was reported. The aim of the present study is to evaluate the influence of this polymorphism on XRCC5 mRNA levels. Genotypes of XRCC5 VNTR were determined by high resolution of melting analysis (HRMA). The quantitative XRCC5 mRNA expression (compared to ß-actin expression) among 0R/1R, 1R/2R, and 1R/3R genotypes was investigated. There was a negative correlation between the overall number of tandem repeats and XRCC5 expression (r = ?0.965, df = 7, P < 0.001). The mRNA level of XRCC5 decreased as function of number of tandem repeats. The 3R allele of the VNTR polymorphism in the XRCC5 promoter region dramatically decreases the gene expression.     

Oral morphology and dietary choices of goats on rangeland

The morphometrics of mandible and teeth of mixed-breed goats on rangeland were analyzed to investigate the association between the oral apparatus and diet type. Canonical relationship between sets of mandible measurements (7) and main plants ingested (17) indicated that, overall, oral characteristics tended to modify ingestive behavior (canonical correlation = 0.81). In general, incisor length had a greater effect (absolute value of standardized coefficient: AVSC = 0.56) on ingestion of Nolina cespitifera than did other mandible variables. Incisor width influenced the ingestion of Parthenium incanum (AVSC = 0.47) and Flourensia cernua (AVSC = 0.43). Distance between the bases of the last most lateral incisors (I₄ or corners) was associated with the ingestion of Atriplex canescens (AVSC = 0.54) and Florensia cernua (AVSC = 0.69). Incisor breath was important for the consumption of Larrea tridentata (AVSC = 0.68) and Cowania plicata (AVSC = 0.50). The ingestion of Agave lechuguilla (AVSC = 0.51) and Sphaeralcea angustifolia (AVSC = 0.43) were influenced principally by muzzle width. Distance between first molars was the variable most closely associated to the ingestion of Buchloe dactyloides (AVSC = 0.51) and Croton dioicus (AVSC = 0.62). Mandible length had a greater effect on the ingestion of F. cernua and Atriplex canescens than did other oral traits. Variation in the oral apparatus did not affect percentage of grasses, forbs and shrubs of goat diets. Fecal nitrogen, fecal phosphorous and number of species consumed were not related to oral traits. These results suggest that different dimensions in the oral apparatus of grazing goats lead to divergent selection of range plants, without altering the quality of their diet.     

Shivering and non-shivering thermogenesis in a marsupial,the eastern barred bandicoot (Perameles gunnii)

We investigated the metabolic rate of the Tasmanian marsupial, the eastern barred bandicoot, Perameles gunnii, before and after acclimation to cold temperature (5 °C) for a 2-week period. Although body temperature did not change significantly, we observed a significant increase in the metabolic rate (MR) when measured at 5 °C before and after cold acclimation. Nor-epinephrine had a significant effect on the metabolic rate when measured in the thermoneutral zone and when measured at 5 °C after cold acclimation; however, there was no significant increase when measured at 5 °C before cold acclimation. Nor-epinephrine also resulted in a small but significant decrease in body temperature. Electromyography (EMG) measurements were obtained before and after cold acclimation during shivering. Shivering decreased after two weeks of cold exposure indicating that the bandicoot had acclimated to that temperature. Nor-epinephrine (NE) significantly reduced shivering before but not after cold acclimation. The metabolic rate and shivering decreased in the adult eastern barred bandicoot after acclimation at 5 °C and nor-epinephrine had similar effects to cold acclimation. Our findings of minor changes in thermal conductance suggest that insulation differences were unlikely explanations for our results. These experiments indicate that this marsupial is able to increase its heat production by non-shivering thermogenesis.     

Bioactivity of powders and essential oils of three Asteraceae plants as post-harvest grain protectants against three major coleopteran pests

Powders and essential oils were obtained from Achillea biebersteinii, A. fragrantissima and Ageratum conyzoides and tested for their insecticidal activity against Sitophilus oryzae, Rhyzopertha dominica and Tribolium castaneum. Composition of the oils was identified by gas chromatography (GC) and GC/mass spectrometry (MS). The tested plants showed adulticidal activity, where toxicity varied with dosage of the plant product, the insect tested and the exposure period. When mixed with grains as ground powders, a dosage of 20 g/kg grains killed 88.2, 73.6 and 64.4% of S. oryzae after 12 days of exposure with 79.6, 63.3 and 48% reduction in progeny for powders of A. biebersteinii, A. conyzoides and A. fragrantissima, respectively. Under the same assay conditions, A. biebersteinii and A. conyzoides powders killed 100% of R. dominica. T. castaneum was less susceptible to the plant powders. The LC₅₀ values for powders were 22.8, 31.6 and 39.7 mg/g grains for A. biebersteinii, 27.1, 35.4 and 47.8 mg/g grains for A. conyzoides and 36.9, 48.3 and 78.6 mg/g grains for A. fragrantissima against R. dominica, S. oryzae and T. castaneum, respectively. Upon fumigation, a dose of 60 μl/L air of A. biebersteinii and A. conyzoides oils was sufficient to kill 100% of R. dominica after 12 days of adult exposure, while 91.3% adult mortality was recorded in the case of A. fragrantissima oil. S. oryzae and T. castaneum showed a great susceptibility to the plant oils. Powders exhibited a moderate to strong residual activity where A. conyzoides showed the greatest grain protecting activity.     

From chronic kidney disease to transplantation: the roles of obestatin

This study was designed to investigate the possible effect of sitagliptin on renal damage induced by renal ischemia reperfusion (I/R) in diabetic rats. T2DM in rats was induced by the administration of nicotinamide (230 mg/kg, i.p.), 15 min prior to a single dose of streptozotocin (65 mg/kg, i.v.). In vivo renal I/R was performed in both T2DM and normal rats. Each protocol comprised ischemia for 30 min followed by reperfusion for 24 h and a treatment period of 14 days before induction of ischemia. Sitagliptin treated diabetic rats that underwent renal I/R demonstrated significant decrease in the serum concentrations of aspartate aminotransferase (p < 0.01), urea nitrogen (p < 0.01) and creatinine (p < 0.001) compared to renal I/R in diabetic rats. Lipid peroxidation, xanthine oxidase activity, myeloperoxidase activity and nitric oxide level in renal tissue were significantly (p < 0.05, p < 0.001, p < 0.01, p < 0.05 respectively) decreased after renal I/R in sitagliptin treated rats compared to diabetic rats. Antioxidant enzymes like glutathione (p < 0.05), glutathione peroxidase (p < 0.001), superoxide dismutase (p < 0.05) and catalase (p < 0.001) were significantly increased after renal I/R in sitagliptin treated diabetic rats compared to non treated diabetic rats. The typical DNA laddering was observed when renal I/R performed in diabetic rats, which indicates cell apoptosis. Sitagliptin treated rats demonstrated a decrease in DNA fragmentation and apoptosis. Furthermore, renal histopathology preserved in sitagliptin treated rats verified protection against renal I/R in diabetes. The results of present investigation established sitagliptin treatment attenuated renal damage induced by renal I/R in diabetic rats.     

Concentration-dependent effects of resveratrol and metabolites on the redox status of human erythrocytes in single-dose studies

Dietary trans-resveratrol (RES) is rapidly metabolized into sulfated and glucuronated conjugates in humans. This study focused on the in vitro determination of the antioxidant capacity of RES and its main physiological metabolites and on its relevance in vivo. In vitro, RES, RES-3-O-sulfate (R3S) and 3-O-glucuronide (R3G) showed antioxidant activities at a concentration of 1 mM when compared to Trolox using an assay in which the antioxidant inhibits iron-induced linoleic acid oxidation: 0.87±0.08 mM Trolox equivalents (TE) for RES, 0.52±0.01 mM TE for R3S and 0.36±0.02 mM TE for R3G. At a concentration of 1 μM, compounds promoted linoleic acid peroxidation (RES −0.30±0.09 mM TE, R3S −0.48±0.05 mM TE and R3G −0.57±0.07 mM TE). To elucidate whether these effects were reflected in vivo, total antioxidant capacity, reactive oxygen species (ROS), conjugated fatty acid dienes (CD), superoxide dismutase (SOD) and catalase (CAT) activities were determined in human plasma and erythrocytes over 24 h, after oral intake of either 0.05 g RES as piceid or 5 g RES. Oral administration of RES did not show an impact on total antioxidant capacity, ROS or CD. However, enzymatic activities of ROS scavenging SOD and CAT were significantly lower after high-dose compared to low-dose administration of RES (P<.03 and P<.01). In conclusion, in healthy subjects, neither 0.05 g nor 5 g RES changed blood oxidative state, although our in vitro data point to a prooxidative activity of low concentrations of RES and its metabolites, which could be important in vivo for individuals with compromised antioxidant defense capacity.     

Association of a polymorphism of the apolipoprotein E gene with chronic kidney disease in Japanese individuals with metabolic syndrome

The purpose of the present study was to identify genetic variants that confer susceptibility to chronic kidney disease (CKD) in Japanese individuals with metabolic syndrome. The study population comprised 2150 Japanese individuals with metabolic syndrome, including 411 subjects with CKD [estimated glomerular filtration rate (eGFR) < 50 mL/min/1.73m²] and 1739 controls (eGFR ≥ 60 mL/min/1.73m²). The genotypes for 100 polymorphisms of 80 candidate genes were determined. The chi-square test, multivariable logistic regression analysis with adjustment for covariates, as well as a stepwise forward selection procedure revealed that nine polymorphisms of APOE, ABCA1, PTGS1, TNF, CPB2, AGTR1, OR13G1, and GNB3 were associated (P < 0.05) with the prevalence of CKD. Among these polymorphisms, the ? 219G → T polymorphism of APOE (rs405509) was most significantly associated with CKD in Japanese individuals with metabolic syndrome.     

Different O3 response of sensitive and resistant snap bean genotypes (Phaseolus vulgaris L.): The key role of growth stage,stomatal conductance,and PSI activity

The ozone (O₃) biomonitoring system based on sensitive (S156) and resistant (R123) genotypes of snap bean (Phaseolus vulgaris L.), was tested in a fumigation experiment, with the aim of: (i) assessing the performance of the S156/R123 system under simulated climatic conditions and O₃ levels often found in Mediterranean sites; (ii) contributing to identify possible ecophysiological mechanisms determining the different O₃ sensitivity of S156 and R123, along different plant growth stages. In contrast with what reported by other authors, differences in stomatal O₃ uptake were evident between sensitive and resistant plants. In particular, R123 plants showed an O₃-induced stomatal closure (−38.1% than the control) during flowering and the onset of visible injury, a behaviour that can be regarded as an O₃ avoidance mechanism. At the end of the fumigation period (AOT40 = 4.66 ppm h), despite the reduction of assimilation and the photoprotective down regulation of PSII photochemistry, the capacity to reduce the final electron acceptors beyond PSI was up-regulated, particularly in S156, while the PSI activity remained constant in both genotypes, an unusual response to O₃ stress. Increased energy demand for maintenance and repair processes also determined increased dark respiration rates (Rd) in all fumigated plants; nocturnal stomatal conductance (g_sN) was also enhanced, differently in the two genotypes, with possible implication for higher nocturnal stomatal uptake of S156 in field conditions. No clear genotype × O₃ effect was instead detected on pod biomass, although a significant O₃-induced reduction of yield was evident in both genotypes.     

Rhizobium ruizarguesonis sp. nov., isolated from nodules of Pisum sativum L

Four strains, coded as UPM1132, UPM1133^T, UPM1134 and UPM1135, and isolated from nodules of Pisum sativum plants grown on Ni-rich soils were characterised through a polyphasic taxonomy approach. Their 16S rRNA gene sequences were identical and showed 100% similarity with their closest phylogenetic neighbors, the species included in the ‘R. leguminosarum group’: R. laguerreae FB206^T, R. leguminosarum USDA 2370^T, R. anhuiense CCBAU 23252^T, R. sophoreae CCBAU 03386^T, R. acidisoli FH13^T and R. hidalgonense FH14^T, and 99.6% sequence similarity with R. esperanzae CNPSo 668^T. The analysis of combined housekeeping genes recA, atpD and glnII sequences showed similarities of 92-95% with the closest relatives. Whole genome average nucleotide identity (ANI) values were 97.5-99.7% ANIb similarity among the four strains, and less than 92.4% with closely related species, while digital DNA-DNA hybridization average values (dDDH) were 82-85% within our strains and 34-52% with closely related species. Major fatty acids in strain UPM1133^T were C18:1 ω7c / C18:1 ω6c in summed feature 8, C14:0 3OH/ C16:1 iso I in summed feature 2 and C18:0. Colonies were small to medium, pearl-white coloured in YMA at 28 °C and growth was observed in the ranges 8-34 °C, pH 5.5-7.5 and 0-0.7% (w/v) NaCl. The DNA G + C content was 60.8 mol %. The combined genotypic, phenotypic and chemotaxonomic data support the classification of strains UPM1132, UPM1133^T, UPM1134 and UPM1135 into a novel species of Rhizobium, for which the name Rhizobium ruizarguesonis sp. nov. is proposed. The type strain is UPM1133^T (=CECT 9542^T = LMG 30526^T).     

Occurrence of human-pathogenic Enterocytozoon bieneusi,Giardia duodenalis and Cryptosporidium genotypes in laboratory macaques in Guangxi,China

Captive nonhuman primates have been identified as common hosts of Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium hominis, and Cyclospora spp., thus are potential reservoirs of some enteric parasites in humans. However, few studies have examined the source and human-infective potential of enteric parasites in laboratory nonhuman primates. In the present work, 205 fecal specimens were collected from three groups of captive Macaca fascicularis kept in different densities in a laboratory animal facility in Guangxi, China, and examined by PCR for E. bieneusi, G. duodenalis, Cryptosporidium spp., and Cyclospora spp. The infection rates of E. bieneusi and G. duodenalis were 11.3% and 1.2% in Group 1 (young animals kept individually; n = 168), 72.2% and 11.1% in Group 2 (young animals kept in groups; n = 18), and 31.6% and 5.3% in Group 3 (adults kept in groups; n = 19), respectively. Sequence analysis of PCR products showed the presence of five E. bieneusi genotypes, with genotype D (in 16/36 genotyped specimens) and a new genotype (in 15/36 genotyped specimens) as the dominant genotypes. All five E. bieneusi genotypes belonged to the zoonotic group (Group 1). The G. duodenalis genotypes (assemblages AII and B) in five specimens and C. hominis subtype (IdA14) in one specimen were also known human-pathogens, although the Cyclospora seen in one animal appeared to be unique to macaque monkeys. The higher infection rate in younger animals reared in groups and common occurrence of zoonotic genotypes indicated that human-pathogenic E. bieneusi could be transmitted efficiently in captive nonhuman primates, and group-housing was a risk factor for transmission of zoonotic pathogens in young nonhuman primates in research facilities.     

Interactions between IL17A, IL23R, and STAT4 polymorphisms confer susceptibility to intestinal Behcet's disease in Korean population

AimsAlthough polymorphisms in IL23R have recently been proposed to predispose to Behcet's disease (BD), associations between IL23R polymorphisms and intestinal BD have yet to be elucidated. We therefore performed a study to evaluate whether IL17A, IL23R, and STAT4 polymorphisms are associated with susceptibility to intestinal BD in the Korean population.Main methodsSingle nucleotide polymorphisms (SNP) in the IL17A, IL23R, and STAT4 genes were analyzed using DNA sequencing, denaturing high performance liquid chromatography, and TaqMan genotyping assays.Key findingsIndividual polymorphism analysis revealed that the TT genotype of IL17A rs8193036 (odds ratio (OR) 2.10, 95% confidence interval (CI) (1.12–3.92), p = 0.021), and GG + GT genotype of IL23R rs1884444 (OR 1.92, 95% CI (1.03–3.57), p = 0.034) was associated with the development of intestinal BD. When these two genotypes were combined, the risk of BD increased compared to that of patients with no-risk or one-risk genotype (OR 2.21, 95% CI (1.13–4.34), p = 0.021). Furthermore, statistically significant gene–gene interactions were observed between G149R in IL23R vs. rs11685878 in STAT4, rs2275913 in IL17A vs. rs7574865 in STAT4, and rs11889341 in STAT4 vs. rs2275913 in IL17A. The haplotypes of IL17A had a positive association with intestinal BD risks, whereas those of IL23R were protective for disease development.SignificanceOur results indicate that the interaction of specific IL17A, IL23R, and STAT4 SNPs modulate susceptibility to intestinal BD in the Korean population, suggesting that the IL-17/23 axis plays a significant role in disease pathogenesis.     

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.