A study on multidimensional time series model of individual age’s measurement in Castanopsis kawakamii population

Studies on disclosing characteristics and endangered mechanisms of Castanopsis kawakamii population ecology have already become an urgent task of protecting C. kawakamii population. The establishment of the standard life table is one of an important work study on C. kawakamii population ecology, and determining individual ages of the plant is necessary for studying age structures and population dynamics of C. kawakamii. There are three main methods of determining individual age of forest population: (1) by annual ring of tree, (2) by individual growth phase, and (3) by DBH and height of tree. However, the three methods have their shortcomings, such as low precision, worse serviceability, high difficulty for operation and so on. In this paper, a new method for determining plant individual ages more accurately is presented on the basis of the method aboU_t “annual ring–time series”. Based on the stem analysis, the multidimensional time series model of diameter growth at breast height in C. kawakamii population was established by U_tilizing the analY_tical method of multidimensional time series: Y_t = 1.325034Y_t-1 ? 0.4711007Y_t-2 ? 284.5648U_t + 569.4783U_t?1 ? 284.8745U_t?2, where Y_t, Y_t-1, Y_t-2 represent diameter growth in C. kawakamii population at t, t ? 10 and t ? 20 years respectively, and U_t, U_t?1, U_t?2 represent individual age in C. kawakamii population at t, t ? 10 and t ? 20 years respectively, the model coefficient correlation is 0.9994. Based on this model CAR(2), the total increment of individual DBH in C. kawakamii population are simulated and regressively verified at different ages. The mean simulating precision of this model was 98.84%, the maximum relative error was 2.56%, bU_t the next was 2.47% and the minimum relative error was 0.07%, showing that this model was suitable for estimating breast-height diameter of C. kawakamii plant. Using the multidimensional time series model, diameter growth of C. kawakamii population for longer time series was estimated in order to gain data for establishing the relationship model of individual age, diameter growth and to increase its precision in determining individual age is by tree ring analysis. A combination method of determining individual age of C. kawakamii population by integrating annual ring data with its diameter using multidimensional time series model, which can improve precision of individual ages in C. kawakami, was produced: A = 9.966671944 + 1.146011591D + 0.041059628D² ? 0.000211907D³, where A and D represent individual age and diameter at breast height respectively in C. kawakamii population, the model coefficient correlation is 0.9998. The combination model, which shows that the regression relationship is significant and the model can exactly predict the individual age of population, is a valuable tool for determining individual ages in endangered plants.     

The inhibitory effect of curcumin on voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells

We investigated the effects of curcumin, the principal active compound of turmeric, on voltage-dependent K⁺ (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells using the voltage-clamp technique. Curcumin reduced the Kv current in a dose-dependent manner with an apparent K_d value of 1.07 ± 0.03 μM. Although curcumin did not alter the kinetics of Kv current activation, it predominantly accelerated the decay rate of channel inactivation. The association and dissociation rate constants of curcumin were 1.35 ± 0.05 μM^?1 s^?1 and 1.47 ± 0.17 s^?1, respectively. Curcumin did not alter the steady-state activation or inactivation curves. Application of train pulses (1 or 2 Hz) increased curcumin-induced blockade of the Kv current, and the recovery time constant also increased in the presence of curcumin suggesting, that the inhibitory action of Kv currents by curcumin was use-dependent. From these results, we concluded that curcumin inhibited vascular Kv current in a state-, time-, and use-dependent manner.     

Nitrogen dioxide oxidizes mitochondrial cytochrome c

We previously reported that high micromolar concentrations of nitric oxide were able to oxidize mitochondrial cytochrome c at physiological pH, producing nitroxyl anion (Sharpe and Cooper, 1998 Biochem. J. 332, 9–19). However, the subsequent re-evaluation of the redox potential of the NO/NO^- couple suggests that this reaction is thermodynamically unfavored. We now show that the oxidation is oxygen-concentration dependent and non stoichiometric. We conclude that the effect is due to an oxidant species produced during the aerobic decay of nitric oxide to nitrite and nitrate. The species is most probably nitrogen dioxide, NO₂^? a well-known biologically active oxidant. A simple kinetic model of NO autoxidation is able to explain the extent of cytochrome c oxidation assuming a rate constant of 3 × 10⁶ M^-1 s^-1 for the reaction of NO₂^? with ferrocytochrome c. The importance of NO₂^? was confirmed by the addition of scavengers such as urate and ferrocyanide. These convert NO₂^? into products (urate radical and ferricyanide) that rapidly oxidize cytochrome c and hence greatly enhance the extent of oxidation observed. The present study does not support the previous hypothesis that NO and cytochrome c can generate appreciable amounts of nitroxyl ions (NO^- or HNO) or of peroxynitrite.     

Bioremediation of oxamyl in sandy soil using animal manures

The bioremediation of the nematicide oxamyl, applied at the recommended rate of 6 l ha^?1 in sandy soil cultivated with tomato and amended with different animal manures at the recommended dose of 2.5 tons ha^?1, was investigated. The experiment was conducted in a controlled environmental chamber under a 16-h photoperiod, with a light intensity of 300 μ Em^?2 s^?1 at 25 °C and relative humidity of 70 ± 5%. The remaining amount of oxamyl in soil was extracted after different time intervals based on the solid phase extraction (SPE) with methanol and then analyzed by HPLC. Only the peak corresponding to oxamyl was observed in the chromatogram and no intermediate could be detected. By the end of the experiment (28 days), the dissipation percentage of oxamyl reached about 99% in the case of bovine manure-amended soil. This rate of disappearance was 1.76 times higher than in unamended-soil, while poultry and sheep manures enhanced the dissipation rate by 1.52 and 1.44 times, respectively. The disappearance rate constants and half-life values of the compound were obtained from the exponential decay equations. The decomposition of oxamyl in the control followed the first order kinetics with t_1/2 of about 26 days. On the other hand, a biphasic model was assumed to explore the disappearance of oxamyl in soil amended with different animal manures where the rate of disappearance in the first phase was faster than the second phase. This is clearly reflected in the half-life (t_1/2) values for the first and second phases, where the t_1/2 values of oxamyl ranged from 3.19 to 5.41 and 9.76 to 43.31 days, respectively. The results demonstrated that animal manures may offer an efficient, cheap, safe, and friendly bioremediator for pesticide-polluted soil.     

Hemodynamic effects of inducible nitric oxide synthase inhibition combined with sildenafil during acute pulmonary embolism

While endogenous nitric oxide (NO) may be relevant to the beneficial hemodynamic effects produced by sildenafil during acute pulmonary embolism (APE), huge amounts of inducible NO synthase (iNOS)-derived NO may contribute to lung injury. We hypothesized that iNOS inhibition with S-methylisothiourea could attenuate APE-induced increases in oxidative stress and pulmonary hypertension and, therefore, could improve the beneficial hemodynamic and antioxidant effects produced by sildenafil during APE. Hemodynamic evaluations were performed in non-embolized dogs treated with saline (n = 4), S-methylisothiourea (0.01 mg/kg followed by 0.5 mg/kg/h, n = 4), sildenafil (0.3 mg/kg, n = 4), or S-methylisothiourea followed by sildenafil (n = 4), and in dogs that received the same drugs and were embolized with silicon microspheres (n = 8 for each group). Plasma nitrite/nitrate (NOx) and thiobarbituric acid reactive substances (TBARS) concentrations were determined by Griess and a fluorometric assay, respectively. APE increased mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance index (PVRI) by 25 ± 1.7 mm Hg and by 941 ± 34 dyn s cm^?5 m^?2, respectively. S-methylisothiourea neither attenuated APE-induced pulmonary hypertension, nor enhanced the beneficial hemodynamic effects produced by sildenafil after APE (>50% reduction in pulmonary vascular resistance). While sildenafil produced no change in plasma NOx concentrations, S-methylisothiourea alone or combined with sildenafil blunted APE-induced increases in NOx concentrations. Both drugs, either alone or combined, produced antioxidant effects. In conclusion, although iNOS-derived NO may play a key role in APE-induced oxidative stress, our results suggest that the iNOS inhibitor S-methylisothiourea neither attenuates APE-induced pulmonary hypertension, nor enhances the beneficial hemodynamic effects produced by sildenafil.     

Moderate hypothermia attenuates α(1)-adrenoceptor-mediated contraction in isolated rat aorta: the role of the endothelium

Moderate hypothermia (25–31 °C) may have a significant influence on vascular tone. We investigated the cellular mechanisms by which moderate hypothermia alters α-adrenoceptor-mediated contraction in rat thoracic aortae. Cyclooxygenase inhibition by indomethacin; nitric oxide (NO) synthase inhibition by l-NAME; potassium channel and endothelium-derived hyperpolarizing factor (EDHF) inhibition by glibenclamide and TEA; G protein inhibition by pertussis toxin; α₂-adrenergic inhibition by yohimbine; and β-adrenergic inhibition by propranolol were assessed for their effect on the contractile response to the α1-adrenoceptor agonist phenylephrine (Phe) in combination with moderate hypothermia (25 °C). Moderate hypothermia produced a shift to the right for the Phe concentration–response curves in endothelium-intact (E+) and endothelium-denuded (E?) aortic rings. The maximal response to Phe in E+ rings was significantly decreased (P < 0.05) at 25 °C compared to 38 °C, whereas there was no significant difference in E? rings. Hypothermia-induced vasorelaxation in E+ rings was attenuated (P < 0.05) following combined pretreatment with l-NAME (10^?4 M) and indomethacin (10^?5 M), whereas other inhibitors had no significant effect. Importantly, the addition of TEA to rings that were pretreated with l-NAME and indomethacin exhibited no further attenuation (P > 0.05) of hypothermia-induced vasorelaxation. The concentrations of cGMP and cAMP, as measured by radioimmunoassay, were significantly increased (P < 0.05) in E+ rings at 25 °C compared to those at 38 °C, whereas there were no significant differences (P > 0.05) in E? rings. The present study demonstrated that rat aortic endothelium is stimulated during moderate hypothermia and that the NO–cGMP and prostacyclin (PGI₂)–cAMP pathways represent endothelium-dependent mechanisms of hypothermia-induced vasorelaxation. In contrast, EDHF may not be associated with hypothermia-induced vasorelaxation.     

Coupled effects of irradiance and iron on the growth of a harmful algal bloom-causing microalga Scrippsiella trochoidea

Effects of irradiance and iron on the growth of a typical harmful algal blooms (HABs) causative dinoflagellate, Scrippsiella trochoidea, were investigated under various irradiances (high light: 70 μmol m^?2 s^?1 and low light: 4 μmol m^?2 s^?1) and iron concentrations (low iron: 0.063 mg L^?1, medium iron: 0.63 mg L^?1 and high iron: 6.3 mg L^?1), and evaluated by the parameters of algal cell density, specific growth rate, optical density and chlorophyll a content. The results indicated that there was significant difference in the cell density of dinoflagellate S. trochoidea between high light and low light intensity treatments across the entire experiments, 7-fold higher at high irradiance as compared with low irradiance, which was further enhanced by the iron concentration. It was found that the maximum cell density of 25 × 10⁴ cell mL^?1 occurred under the combination of high light intensity and high iron concentration, followed by 23 × 10⁴ cell mL^?1 in the combination of high light and medium iron, and 20 × 10⁴ cell mL^?1 in the combination of high light and low iron. There was no significant effect of iron concentration on the cell density under low light intensity. The cell density maintained about 3 × 10⁴ cell mL^?1 across all combinations of iron concentrations and low light in the end of experiments. Such interactive effects of light intensity and iron level dependent were also observed for the specific growth rate, OD₆₈₀ and chlorophyll a content of S. trochoidea. The maximum values of specific growth rate, OD₆₈₀ and chlorophyll a content peaked at the condition of high irradiance and high iron, which were 0.22 d^?1, 0.282 and 0.673 mg L^?1, respectively. In general, their values increased significantly with the increasing of iron concentration at high irradiance, whereas no significant difference was observed among three iron concentrations at low irradiance, all remaining approximately 0.06 d^?1, 0.03 and 0.050 mg L^?1, respectively. Those results suggest that there may be a strong interactive effect between irradiance and iron on microalgal growth and their physiological characteristics. The combination of high light and high iron concentration may accelerate algal cell growth and pigment biosynthesis, thus leading to massive occurrence of HABs.     

Predictive modeling of biomass production by Spirulina platensis as function of nitrate and NaCl concentrations

Effects of nitrate (2.0, 2.5, and 3.0 g L^?1) and salt (0.5, 1.0, 1.5, 2.0 g L^?1) concentrations on biomass production by Spirulina platensis was examined in the Schlösser medium. The highest (p < 0.001) biomass yields and chlorophyll a content was observed at 2.5 g L^?1 nitrate and 1.5 g L^?1 NaCl as 3.495 g L^?1 and 29.92 mg L^?1, respectively. Increment rate of biomass production was especially found between 72 and 216 h. Modified Richards, Schnute, Logistic and Gompertz models was successfully predicted (r² > 0.96 and RSS ? 0.003) biomass production by S. platensis as function of nitrate and salt concentrations. Low residual sum of squares (RSS) and high regression coefficients (r²) indicated that used models were well fitted to the experiment data and it could be regarded as sufficient to describe biomass production of Spirulina sp. Biological variables i.e. production rate (μ) and lag time (λ) for S. platensis ranged 0.012–0.034 h^?1 and 2.43–5.85 h, respectively from biomass production were successfully predicted by modified Logistic model according to low RSS and F-testing value.     

Pseudo-enzymatic hydrolysis of 4-nitrophenyl acetate by human serum albumin: pH-dependence of rates of individual steps

Human serum albumin (HSA) displays esterase activity reflecting multiple irreversible chemical modifications rather than turnover. Here, kinetics of the pseudo-enzymatic hydrolysis of 4-nitrophenyl acetate (NphOAc) are reported. Under conditions where [HSA] ? 5×[NphOAc] and [NphOAc] ? 5×[HSA], the HSA-catalyzed hydrolysis of NphOAc is a first-order process for more than 95% of its course. From the dependence of the apparent rate constants k_app and k_obs on [HSA] and [NphOAc], respectively, values of K_s, k₊₂, and k₊₂/K_s were determined. Values of K_s, k₊₂, and k₊₂/K_s obtained at [HSA] ? 5×[NphOAc] and [NphOAc] ? 5×[HSA] are in good agreement, the deacylation step being rate limiting in catalysis. The pH-dependence of k₊₂/K_s, k₊₂, and K_s reflects the acidic pK_a shift of the Tyr411 catalytic residue from 9.0 ± 0.1 in the substrate-free HSA to 8.1 ± 0.1 in the HSA:NphOAc complex. Accordingly, diazepam inhibits competitively the HSA-catalyzed hydrolysis of NphOAc by binding to Tyr411.     

Horseradish peroxidase compound I as a tool to investigate reactive protein-cysteine residues: from quantification to kinetics

Proteins containing reactive cysteine residues (protein-Cys) are receiving increased attention as mediators of hydrogen peroxide signaling. These proteins are mainly identified by mining the thiol proteomes of oxidized protein-Cys in cells and tissues. However, it is difficult to determine if oxidation occurs through a direct reaction with hydrogen peroxide or by thiol–disulfide exchange reactions. Kinetic studies with purified proteins provide invaluable information about the reactivity of protein-Cys residues with hydrogen peroxide. Previously, we showed that the characteristic UV–Vis spectrum of horseradish peroxidase compound I, produced from the oxidation of horseradish peroxidase by hydrogen peroxide, is a simple, reliable, and useful tool to determine the second-order rate constant of the reaction of reactive protein-Cys with hydrogen peroxide and peroxynitrite. Here, the method is fully described and extended to quantify reactive protein-Cys residues and micromolar concentrations of hydrogen peroxide. Members of the peroxiredoxin family were selected for the demonstration and validation of this methodology. In particular, we determined the pK_a of the peroxidatic thiol of rPrx6 (5.2) and the second-order rate constant of its reactions with hydrogen peroxide ((3.4 ± 0.2) × 10⁷ M^? 1 s^? 1) and peroxynitrite ((3.7 ± 0.4) × 10⁵ M^? 1 s^? 1) at pH 7.4 and 25 °C.     

Methane output of rabbits (Oryctolagus cuniculus) and guinea pigs (Cavia porcellus) fed a hay-only diet: implications for the scaling of methane production with body mass in non-ruminant mammalian herbivores

It is assumed that small herbivores produce negligible amounts of methane, but it is unclear whether this is a physiological peculiarity or simply a scaling effect. A respiratory chamber experiment was conducted with six rabbits (Oryctolagus cuniculus, 1.57 ± 0.31 kg body mass) and six guinea pigs (Cavia porcellus, 0.79 ± 0.07 kg) offered grass hay ad libitum. Daily dry matter (DM) intake and DM digestibility were 50 ± 6 g kg^? 0.75 d^? 1 and 55 ± 6% in rabbits and 59 ± 11 g kg^? 0.75 d^? 1 and 61 ± 3% in guinea pigs, respectively. Methane production was similar for both species (0.20 ± 0.10 L d^? 1 and 0.22 ± 0.08 L d^? 1) and represented 0.69 ± 0.32 and 1.03 ± 0.29% of gross energy intake in rabbits and guinea pigs, respectively. In relation to body mass (BM) guinea pigs produced significantly more methane. The data on methane per unit of BM obtained in this study and from the literature on the methane output of elephant, wallabies and hyraxes all lay close to a regression line derived from roughage-fed horses, showing an increase in methane output with BM. The regression, including all data, was nearly identical to that based on the horse data only (methane production in horses [L d^? 1] = 0.18 BM [kg]^{0.97 (95%CI 0.92–1.02)}) and indicates linear scaling. Because feed intake typically scales to BM^0.75, linear scaling of methane output translates into increasing energetic losses at increasing BM. Accordingly, the data collection indicates that an increasing proportion of ingested gross energy is lost because relative methane production increases with BM. Different from ruminants, such losses (1%–2% of gross energy) appear too small in non-ruminant herbivores to represent a physiologic constraint on body size. Nevertheless, this relationship may represent a physiological disadvantage with increasing herbivore body size.     

Carbon stock and allocation of five restoration ecosystems in subalpine coniferous forest zone in Western Sichuan Province, Southwest China

As the largest carbon pool of the terrestrial ecosystem, forest plays a key role in sequestrating and reserving greenhouse gases. With the method of replacing space with time, the typical restoration ecosystems of herb (dominated by Deyeuxia scabrescens, P1), shrub (dominated by Salix paraqplesia, P2), broadleaf (dominated by Betula platyphylla, P3), mixed forest (dominated by Betula spp. and Abies faxoniana, P4), and climax (dominated by Abies faxoniana, P5) were selected to quantify the carbon stock and allocation in the subalpine coniferous forest in Western Sichuan (SCFS). The results indicated that the soil organism carbon (SOC) stock decreased with the depth of soil layer, and the SOC per layer and the total SOC increased largely with the vegetation restoration. The contribution of SOC to the carbon stock of ecosystems decreased with the vegetation restoration from 89.45% to 27.06%, while the quantity was from 94.00 to 223.00 t C hm^?2. The carbon stock in ground cover increased with the vegetation restoration, and its contribution to the carbon stock of ecosystems was similar (3–4% of the total). Following the vegetation restoration, the plant carbon stock multiplied and reached to 430.86 ± 49.49 t C hm^?2 at the climax phase. During the restoration, the carbon stock of different layers increased, and the contribution of belowground to the carbon stock of ecosystems decreased sharply. The carbon stock on ecosystem scale of the climax phase was 5.89 times that of the herb phase. Our results highlighted that the vegetation restoration in SCFS was a large carbon sink.     

Action of ANP on the nongenomic dose-dependent biphasic effect of aldosterone on NHE1 in proximal S3 segment

The rapid (2 min) nongenomic effects of aldosterone (ALDO) and/or spironolactone (MR antagonist), RU 486 (GR antagonist), atrial natriuretic peptide (ANP) and dimethyl-BAPTA (BAPTA) on the intracellular pH recovery rate (pHirr) via NHE1 (basolateral Na⁺/H⁺ exchanger isoform), after the acid load induced by NH₄Cl, and on the cytosolic free calcium concentration ([Ca²⁺]_i) were investigated in the proximal S3 segment isolated from rats, by the probes BCECF-AM and FLUO-4-AM, respectively. The basal pHi was 7.15 ± 0.008 and the basal pHirr was 0.195 ± 0.012 pH units/min (number of tubules/number of tubular areas = 16/96). Our results confirmed the rapid biphasic effect of ALDO on NHE1: ALDO (10^?12 M) increases the pHirr to approximately 59% of control value, and ALDO (10^?6 M) decreases it to approximately 49%. Spironolactone did not change these effects, but RU 486 inhibited the stimulatory effect and maintained the inhibitory effect. ANP (10^?6 M) or BAPTA (5 × 10^?5 M) alone had no significant effect on NHE1 but prevented both effects of ALDO on this exchanger. The basal [Ca²⁺]_i was 104 ± 3 nM (15), and ALDO (10^?12 or 10^?6 M) increased the basal [Ca²⁺]_i to approximately 50% or 124%, respectively. RU 486, ANP and BAPTA decreased the [Ca²⁺]_i and inhibited the stimulatory effect of both doses of ALDO. The results suggest the involvement of GR on the nongenomic effects of ALDO and indicate a pHirr-regulating role for [Ca²⁺]_i that is mediated by NHE1, stimulated/impaired by ALDO, and affected by ANP or BAPTA with ALDO. The observed nongenomic hormonal interaction in the S3 segment may represent a rapid and physiologically relevant regulatory mechanism in the intact animal under conditions of volume alterations.     

The effect of PI3 kinase inhibitor LY294002 on voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells

AimsWe examined the effect of LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor, on voltage-dependent K⁺ (Kv) channels.Main methodsElectrophysiological recordings were performed in freshly isolated rabbit coronary arterial smooth muscle cells.Key findingsThe Kv current amplitude was inhibited by LY294002 in a dose-dependent manner, with a K_d value of 1.48 μM. Without alteration of the kinetics of activation, LY294002 accelerated the decay rate of Kv channel inactivation. The rate constants of association and dissociation for LY294002 were 1.83 ± 0.01 μM^? 1 s^? 1 and 2.59 ± 0.14 s^? 1, respectively. Application of LY294002 had no significant impact on the steady-state activation or inactivation curves. In the presence of LY294002, the recovery time constant from inactivation was increased, and Kv channel inhibition increased under train pulses (1 or 2 Hz). This indicates that LY294002-induced Kv channel inhibition is use-dependent. Furthermore, pretreatment with another PI3K inhibitor, wortmannin (10 μM), did not affect the Kv current, and did not change the inhibitory effect of LY294002.SignificanceBased on these results, we suggest that LY294002 directly blocks Kv current irrespective of PI3K inhibition.     

Effect of transcatheter renal arterial embolization combined with cryoablation on regulatory CD4+CD25+ T lymphocytes in the peripheral blood of patients with advanced renal carcinoma

ObjectiveTo analyze the effect of Argon-Helium cryosurgery (AHCS) combined with transcatheter renal arterial embolization (TRAE) on the differentiation of regulatory CD4⁺ CD25⁺ T cell (Treg) and its implication in patients with renal carcinoma.MethodsSeventy seven patients are included in the study, and divided into two groups: TRAE group (n = 45, receiving TRAE only) and TRAE + cryoablation group (n = 32, receiving cryoablation 2–3 weeks after TRAE). The percentage of Treg cells and T lymphocyte subsets (CD4⁺T, CD8⁺T, and CD4⁺T/CD8⁺T) in the peripheral blood is measured by flow cytometry previous to the therapy and 3 months after therapy. Meanwhile, the extent of tumor necrosis is measured by MRI or CT 1 month after therapy.ResultsThe percentages of Treg cells of patients in TRAE + cryoablation group decrease from (6.65 ± 1.22)% to (3.93 ± 1.16)%, (t = 42.768, P < 0.01), and the percentages of CD4⁺T and CD4⁺T/CD8⁺T increase significantly (P < 0.01). However, the results of patients in TRAE group show that the percentages of Treg, CD4⁺T, CD8⁺T and CD4⁺T/CD8⁺T increase slightly although the differences had no statistical significance (P > 0.05). The tumor necrosis rate of TRAE + cryoablation group is 57.5%, significantly higher than those of TRAE group, which shows 31.6% (t = 6.784, P < 0.01). The median survival duration of the TRAE + cryoablation group is 20 months, significantly longer than that of the TRAE group (χ² = 7.368, P < 0.01). The decreasing extent of Treg cells is correlated with tumor necrosis rates (r = 0.90, P < 0.01) and life time (r = 0.67, P < 0.01).ConclusionThe therapy of TRAE combined with cryoablation contributes to reduce the percentage of Treg cells and improve the immune situation of patients with renal cell carcinoma, which consequently increase tumor necrosis rate and prolong the patients‘ survival duration.     

Study on alanine aminotransferase kinetics by microchip electrophoresis

Alanine aminotransferase (ALT), which catalyzes the reversible conversion between l-glutamic acid (l-Glu) and l-alanine (l-Ala), is one of the most active aminotransferases in the clinical diagnosis of liver diseases. This work displays a microanalytical method for evaluating ALT enzyme kinetics using a microchip electrophoresis laser-induced fluorescence system. Four groups of amino acid (AA) mixtures, including the substrates of ALT (l-Glu and l-Ala), were effectively separated. Under the optimized conditions, the quantitative analysis of l-Glu and l-Ala was conducted and limits of detection (signal/noise = 3) for l-Glu and l-Ala were 4.0 × 10^?7 and 2.0 × 10^?7 M, respectively. In the reaction catalyzed by ALT, enzyme kinetic constants were determined for both the forward and reverse reactions by monitoring the concentration decrease of substrate AAs (l-Ala and l-Glu), and the K_m and V_max values were 10.12 mM and 0.48 mM/min for forward reaction and 3.22 mM and 0.22 mM/min for reverse reaction, respectively. Furthermore, the applicability of this assay was assessed by analysis of real serum samples. The results demonstrated that the proposed method could be used for kinetic study of ALT and shows great potential in the real application.     

Synthesis of highly potent novel anti-tubercular isoniazid analogues with preliminary pharmacokinetic evaluation

Thirty two novel isoniazid analogues were prepared by one-pot three component condensations of isoniazid (INH), 3-mercaptopropionic acid and various aryl/heteroaryl aldehydes. The synthesized compounds were evaluated for their anti-TB activity against Mycobacterium tuberculosis H37Rv (MTB) and cytotoxicity. Among the compounds, compound N-(2-(4-(benzyloxy) phenyl)-4-oxo-1,3-thiazinan-3-yl) isonicotinamide (17) inhibited MTB with MIC of 0.12 μM and was three times more potent than INH. The main pharmacokinetic parameters after intravenous administration (10 mg/kg body weight) in male Wistar rats viz. t_½, K_el, mean plasma clearance and mean volume of distribution were found to be 1.14 ± 0.20 h, 0.62 ± 0.10 h^?1, 22.48 ± 0.16 mL/kg/min and 1.99 ± 0.49 L, respectively. The systemic absorption was slow after oral administration (50 mg/kg body weight). The peak plasma concentration was found to be 1.31 ± 0.06 μg/mL attained in 3 h. The bioavailability was found to be 16.7%.     

Root health evaluation of three alfalfa varieties in Kerquin sandy land

Without a robust and healthy root system, establishment, productivity, and persistence are compromised. Consequently, research on alfalfa root morphology and health is very important in development of technology for efficient improvement and production of alfalfa. The objectives of this study were to evaluate the root morphology and health of three alfalfa varieties, Algonquin, Golden Queen, and Yellow Flower and to determine relationships among root morphology traits and root health. Yields from these varieties ranged from 5.83 to 43.93 t/ha, total root length ranged from 215.17 to 708.89 mm, root surface area from 124.95 to 468.37 cm², volume from 3.24 to 57.72 cm³, and forks from 1.25 × 10³ to 10.54 × 10³, and tips from 0.65 × 10³ to 3.17 × 10³. Root infestation score was negatively correlated with yield (r = ?0.997, P < 0.01), and was positively correlated with all root morphology traits (r = 0.466–0.997, P < 0.01), and yield was negatively associated with root morphology traits (r = ?0.755 to ?0.998, p < 0.01) with the exception of root tips (r = 0.448, P < 0.01). Results from these analyses indicated that root infestation score was the lowest averaged over age of alfalfa stand in Algonquin. Yield in 2-year old stands was greater in Golden Queen compared to the other two cultivars.     

Storage xyloglucans: potent macrophages activators

Storage xyloglucans from the seeds of Copaifera langsdorffii, Hymenaea courbaril and Tamarindus indica were obtained by aqueous extraction from the milled and defatted cotyledons, XGC, XGJ and XGT, respectively. The resulting fractions showed similar monosaccharide composition with Glc:Xyl:Gal molar ratios of 2.4:1.5:1.0, 3.8:1.5:1,0 and 3.6:2.4:1.0 for XGC, XGJ and XGT, respectively. High-performance size-exclusion chromatography of the polysaccharides showed unimodal profiles, and the average molar mass (M_w) was obtained for XGC (9.6 × 10⁵ g/mol), XGJ (9.1 × 10⁵ g/mol) and XGT (7.3 × 10⁵ g/mol). The immunomodulatory effects of the xyloglucans on peritoneal macrophages were evaluated. Phagocytic activity was observed in macrophages treated with XGT. The effect of XGT was tested on the production of O₂^? and NO. At 25 μg/ml XGT caused a 100% increase in NO production when compared to the control group; however, it did not affect O₂^? production in the absence of PMA. The production of TNF-α, interleukins 1β and 6 by macrophages in the presence of the xyloglucans was evaluated. The polysaccharides affected the production of the cytokines by macrophages to different degrees. XGC caused an enhancement of IL-1β and TNF-α production, compared to the other xyloglucans. For IL-6 production, XGT gave greater stimulation than XGC and XGJ, reaching 87% at 50 μg/ml. XGJ promoted a statistically significant effect on all cytokine productions tested. The results indicate that the xyloglucans from C. langsdorffii, H. courbaril and T. indica can be classified as biological response modifiers (BRM).     

Extracellular alkalinization induces endothelium-derived nitric oxide dependent relaxation in rat thoracic aorta

AimTo investigate the mechanism through which the extracellular alkalinization promotes relaxation in rat thoracic aorta.MethodsThe relaxation response to NaOH-induced extracellular alkalinization (7.4–8.5) was measured in aortic rings pre-contracted with phenylephrine (Phe, 10^?6 M). The vascular reactivity experiments were performed in endothelium-intact and -denuded rings, in the presence or and absence of indomethacin (10^?5 M), NG-nitro-l-arginine methyl ester (L-NAME, 10^?4 M), N-(6-Aminohexyl)-5-chloro-1-naphthalenesulfonamide/HCl (W-7, 10^?7 M), 2,5-dimethylbenzimidazole (DMB, 2 × 10^?5 M) and methyl-β-cyclodextrin (10^?2 M). In addition, the effects of NaOH-induced extracellular alkalinization (pH 8.0 and 8.5) on the intracellular nitric oxide (NO) concentration was evaluated in isolated endothelial cells loaded with diaminofluorescein-FM diacetate (DAF-FM DA, 5 μM), in the presence and absence of DMB (2 × 10^?5 M).ResultsThe extracellular alkalinization failed to induce any change in vascular tone in aortic rings pre-contracted with KCl. In rings pre-contracted with Phe, the extracellular alkalinization caused relaxation in the endothelium-intact rings only, and this relaxation was maintained after cyclooxygenase inhibition; completely abolished by the inhibition of nitric oxide synthase (NOS), Ca²⁺/calmodulin and Na⁺/Ca²⁺ exchanger (NCX), and partially blunted by the caveolae disassembly.ConclusionsThese results suggest that, in rat thoracic aorta, that extracellular alkalinization with NaOH activates the NCX reverse mode of endothelial cells in rat thoracic aorta, thereby the intracellular Ca²⁺ concentration and activating the Ca²⁺/calmodulin-dependent NOS. In turn, NO is released promoting relaxation.