GS Levels Research Articles

Nerve damage induced skeletal muscle atrophy is associated with increased accumulation of intramuscular glucose and polyol pathway intermediates

Perturbations in skeletal muscle metabolism have been reported for a variety of neuromuscular diseases. However, the role of metabolism after constriction injury to a nerve and the associated muscle atrophy is unclear. We have analyzed rat tibialis anterior (TA) four weeks after unilateral constriction injury to the sciatic nerve (DMG) and in the contralateral control leg (CTRL) (n = 7) to investigate changes of the metabolome, immunohistochemistry and protein levels. Untargeted metabolomics identified 79 polar metabolites, 27 of which were significantly altered in DMG compared to CTRL. Glucose concentrations were increased 2.6-fold in DMG, while glucose 6-phosphate (G6-P) was unchanged. Intermediates of the polyol pathway were increased in DMG, particularly fructose (1.7-fold). GLUT4 localization was scattered as opposed to clearly at the sarcolemma. Despite the altered localization, we found GLUT4 protein levels to be increased 7.8-fold while GLUT1 was decreased 1.7-fold in nerve damaged TA. PFK1 and GS levels were both decreased 2.1-fold, indicating an inability of glycolysis and glycogen synthesis to process glucose at sufficient rates. In conclusion, chronic nerve constriction causes increased GLUT4 levels in conjunction with decreased glycolytic activity and glycogen storage in skeletal muscle, resulting in accumulation of intramuscular glucose and polyol pathway intermediates.

Differences in leaf physiology among juvenile pines and oaks following high-severity wildfire in an Arizona Sky Island Mountain range

Recent increases in wildfire severity are converting pine-oak (Pinus-Quercus) woodland to oak shrubland in many sites in the southwestern United States. A key mechanism underlying this transition is the vigorous resprouting capacity of oaks compared to low regeneration rates in pines following wildfire. Differences among species in leaf physiological characteristics may also contribute to such vegetation type conversions, especially in the context of recent increased regional aridity. To that end, we evaluated variation in leaf functional traits in post-fire recruits five years after the 2011 Horseshoe Two in the Chiricahua Mountains, Arizona, USA. We measured a suite of functional traits in two pines (Pinus engelmannii and P. leiophylla) and two oaks (Quercus hypoleucoides and Q. arizonica), including leaf gas exchange, leaf pigment concentrations, leaf spectral reflectance, and wood xylem δ13C, δ18O isotopes, and integrated water use efficiency (iWUE). The four study species displayed a range of plant functional traits tied to desiccation tolerance. P. engelmannii seedling recruits presented invariably low maximum photosynthetic rate (Amax), stomatal conductance (gs), and transpiration (E), and high relative leaf water content during the peak of the May-June drought, a response strongly indicative of a desiccation-avoidant leaf that prioritizes water conservation over carbon fixation in arid conditions. In contrast, resprouts of both oaks displayed leaf desiccation tolerance, with high levels of gs and E and low relative leaf water content. Gas exchange in P. leiophylla resprouts was more similar to the oaks, except for relative water content, which was similar to that of P. engelmannii. Compared to the other two species, P. engelmannii and Q. hypoleucoides exhibited significantly higher δ13C, δ18O and iWUE values—a pattern that appears to have arisen from different mechanisms in the two species. In desiccation-avoidant P. engelmannii, low instantaneous gs and high δ18O suggested that low stomatal conductance rather than high photosynthetic rates led to high iWUE, whereas lower δ18O and very high pigment concentrations in Q. hypoleucoides suggest a more important role for Amax in this species. Neither fire severity nor physiography influenced the physiological responses in any of the four species, suggesting that the expression of resprout and seedling functional traits is fixed. These results raise the possibility that differences in leaf physiological characteristics contribute to the regeneration success of some oak species and the poor seedling establishment of obligate seeder pines, such as P. engelmannii, after high-severity wildfire in the American Southwest.

Sulodexide increases mRNA expression of glutathione-related genes in human umbilical endothelial cells exposed to oxygen-glucose deprivation.

IntroductionSulodexide (SDX), a heparinoid used to treat vascular diseases, exerts anti-ischemic properties. However, the underlying molecular mechanisms remain unclear. Induction of glutathione (GSH)-dependent genes protects against ischemia. Here, we investigated the effect of SDX on GSH-associated gene expression in human umbilical endothelial cells (HUVECs) using an in vitro ischemia model.MethodsThe transcriptional expression of GSH-related genes (GCLc, xCT, GS, GPx1 and GR) in HUVECs treated without/with SDX (0.5 LRU/ml) under oxygen-glucose deprivation (OGD) condition for 1–6 h was analyzed by real-time polymerase chain reaction.ResultsGCLc and xCT were strongly up-regulated by SDX in HUVECs in the first 2 h of OGD. GS and GPx1 mRNA expression levels were significantly increased during any time interval in ischemic HUVECs treated with SDX. Furthermore, incubation of HUVECs with SDX in OGD for 1–4 h resulted in enhanced expression of GR.ConclusionsOur studies provide the first evidence that SDX activates GSH-related genes in OGD-injured HUVECs.

Exogenous Glucose Mediates the Regulation of Root Morphology and Carbon–Nitrogen Metabolism by Indole-3-Acetic Acid (IAA) in Malus baccata (L.) Borkh. in Soil with Low Organic Carbon Content

The effects of an exogenous organic carbon source (i.e., glucose) and indole-3-acetic acid (IAA) on root architecture and carbon–nitrogen (C–N) metabolism of apple rootstock were evaluated under soil organic matter (SOM)-restricted conditions. Malus baccata (L.) Borkh. seedlings were exposed to 1.5 g kg−1 glucose (GLC), 0.09 g kg−1 IAA, 0.06 g kg−1 2,3,5-triiodobenzoic acid (TIBA, a widely used auxin polar transport inhibitor), GLC + IAA, or GLC + TIBA for 30 days. Both GLC and IAA promoted root architecture and growth by regulating SHY2, SHR, ALF4, and LBD11. They also enhanced C–N metabolism, and accelerated nitrate transformation to amino acids. In contrast, TIBA reduced endogenous IAA content in root and inhibited plant growth and C–N metabolism by downregulating expression of auxin polar transport genes, although auxin biosynthesis genes were induced. These adverse effects could be alleviated in GLC + TIBA, which exhibited higher endogenous IAA content in root than TIBA-treated seedlings alone, due to the upregulated expression of auxin biosynthesis genes (YUCCA8, TAR2, TAA1, and CYP79B3) and polar transport genes (PIN1, AUX1, and LAX2). In addition, the enhanced transcription and activities of enzymes involved in C metabolism (PEPC, NADP-ME, and NADP-ICDH) could provide more organic acids, adenosine triphosphate (ATP), and energy charge for N metabolism in roots under GLC + TIBA than in roots under TIBA. The induced NR, GS, NADH-GDH, NADH-GOGAT activities and mRNA levels of genes involved in N metabolism indicated the higher N assimilation ability in roots under GLC + TIBA than in roots under TIBA alone. In conclusion, exogenous glucose-mediated IAA biosynthesis and polar transport regulates root architecture and C–N metabolism of M. baccata (L.) Borkh. under low-SOM conditions.

Test-retest reliability and measurement errors of grip strength test in patients with traumatic injuries in the upper extremity: a cross-sectional study

BackgroundGrip strength (GS) test is an essential aspect of clinical practice with patients with upper extremity injuries. The random error of GS test was hypothesized to be proportional to the level of GS. The purpose of the current study was to estimate a precise range for the measurement error of GS in patients following traumatic injuries in the upper extremity.MethodsFollowing traumatic injuries in the upper extremity, 109 participants completed GS tests twice one weekend apart. The Bland-Altman plot analysis was adopted to estimate the precise limits of agreement with 95% confidence interval (CI).ResultsThe mean of three consecutive trials had a higher intraclass correlation coefficient of 0.974 (95% CI = 0.963, 0.982) than those of one trial and the mean of the first two trials in injured upper extremities. When GS was ≤20 kg, the upper limit of agreement with 95% CI was estimated as (0.41 × average GS + 1.24), while the lower limit was estimated as (− 0.41 × average GS − 0.39). A table of one-to-one matches between averaged GS ≤ 20 kg and transformed ranges of random errors with 95% certainty was created; the standard error of measurement and minimal detectable change with 95% certainty of GS test were 1.8 and 4.9 kg, respectively. When GS was > 20 kg, the width of agreement with 95% CI ranged from − 4.9 to 5.3 kg, and the standard error of measurement and minimal detectable change with 95% certainty were 1.8 and 5.1 kg, respectively.ConclusionThe one-to-one match table can be considered as a practical tool to judge a change in GS score is real or due to random errors when it is ≤20 kg.

Honokiol alleviates acetaminophen-induced hepatotoxicity via decreasing generation of acetaminophen-protein adducts in liver

AimAcetaminophen (APAP) overdose is the most frequent cause of drug-induced liver damage. Magnolia officinalis is a traditional hepatoprotective Chinese medicine and Honokiol (HO) is the major active constituent. The present study was to investigate the effect of HO on APAP-induced hepatotoxicity and related mechanisms. Main methodsFour groups of mice were subjected to treatment as vehicle, APAP, APAP + HO and APAP + HO + NRF2 inhibitor. The morphological and biochemical assessments were used to evaluate the hepatoprotective effects. The extent of APAP-protein adducts was determined through evaluate the hepatic content 3‑(cystein‑S‑yl)acetaminophen (APAP-Cys), the hydrolysis products of APAP-protein adducts. The activities of CYP2E1, CYP1A2 and CYP3A4 were evaluated by cocktail incubation, and the protein expression levels of NRF2, GCLC, GCLM, GS and GST were evaluated by western blot analysis. Key findingsMorphological and biochemical assessments clearly demonstrated that HO could alleviate APAP-induced liver damage. The hepatoprotective effect of HO was positively associated with the reduction of APAP-protein adducts. Further investigation suggested that HO induced inhibition of CYP 2E1 and CYP2A1 as well as upregulation of GSH co-contributed to the reduction of APAP-protein adducts. Furthermore, HO induced activations of NRF2 and its target enzymes, such as GCLC, GCLM and GST, gave rise to the upregulation of GSH. SignificanceOur results suggested that HO could alleviate APAP-induced liver damage through reducing the generation of APAP-protein adducts, which might be mediated by inhibiting the activity of CYP 2E1 and CYP2A1 as well as enhancing the generation of GSH via NRF2 pathway.

Tetramethylpyrazine attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells through regulating apoptosis, autophagy and oxidative damage.

Background: Bupivacaine (BUP) acts as a local anesthetic, which is extensively used for clinical patients but could generate neurotoxicity in neurons. Tetramethylpyrazine (TET) exhibits strong neuron protective effects against neurotoxicity. Hence, we investigate the effect of TET on BUP-induced neurotoxicity in SH-SY5Y cells.Methods: CCK-8 assay was used to detect cell proliferation in SH-SY5Y cells. In addition, Western blotting was used to examine Bax, Bcl-2, active caspase 3, LC3II, Beclin 1 and p-62 protein levels in cells. Moreover, ELISA assay was used to detect the levels of total glutathione (GS), superoxide dismutase (SOD) and malondialdehyde (MDA) in cells.Results: In this study, we found that TET attenuated the neurotoxicity of BUP on SH-SY5Y cells. Meanwhile, TET alleviated BUP-induced apoptosis in SH-SY5Y cell via decreasing the expressions of active caspase-3 and Bax and increasing the expression of Bcl-2. In addition, monodansylcadaverine staining assay and Western blotting results confirmed that TET induced autophagy in SH-SY5Y cells via increasing the LC3II/I and Beclin 1 levels. Furthermore, TET attenuated BUP-induced oxidative damage in SH-SY5Y cells via upregulation of the levels of total GS and SOD and downregulation of the level of MDA. Interesting, the protective effects of TET against BUP-induced neurotoxicity in SH-SY5Y cells were reversed by autophagy inhibitor 3-methyladenine (3MA).Conclusion: These data indicated that TET may play a neuroprotective role via inhibiting apoptosis and inducing autophagy in SH-SY5Y cells. Therefore, TET may be a potential agent for the treatment of human neurotoxicity induced by BUP.

Polyamines protect mung bean [Vigna radiata (L.) Wilczek] plants against drought stress

Drought is a major environmental factor that limits crops productivity. To cope with the adverse effects of drought, plants have evolved various adaptive mechanisms, such as accumulation of osmolytes. Polyamines (PAs) play an important role in the plant growth and development and response to abiotic stresses. This experiment was conducted to investigate the role of exogenous PAs on drought tolerance of mung bean. Mung bean seeds were soaked in 0 or 100 uM putrescine (Put), spermidine (Spd), spermine (Spm), or their mixture for 10 hr. Then, treated seeds were sown in the field and were exposed to drought stress condition. The growth attributes including shoot length, biomass, leaf area index (LAI), and grain yield markedly reduced due to drought stress. Drought stress also decreased soluble protein content, relative water content (RWC), chlorophyll value, stomatal conductance (gs), and net photosynthetic rate (PN) but increased malondialdehyde (MDA), total soluble sugars (TSS), and proline contents. Nonetheless, seed priming with the mixture of PAs alleviated adverse effects of drought stress and improved all growth attributes. Exogenous application of PAs also increased soluble protein content, RWC, chlorophyll value, PN, and more increased TSS and proline contents but decreased gs and MDA level. These results indicated that seed treatment with PAs especially combined treatment of Put + Spd + Spm could enhance drought tolerance of mung bean plants through the accumulation of osmoprotectants, improving water status, chlorophyll value, and PN as well as reduction of oxidative damage.

Exploring Pairwise Chemical Crosslinking To Study Peptide-Receptor Interactions.

Pairwise crosslinking is a powerful technique to characterize interactions between G protein coupled receptors and their ligands in the live cell. In this work, the "thiol trapping" method, which exploits the proximity-enhanced reaction between haloacetamides and cysteine, is examined to identify intermolecular pairs of vicinal positions. By incorporating cysteine into the corticotropin-releasing factor receptor and either α-chloro- or α-bromoacetamide groups into its ligands, it is shown that thiol trapping provides highly reproducible signals and a low background, and represents a valid alternative to classical "disulfide trapping". The method is advantageous if reducing agents are required during sample analysis. Moreover, it can provide partially distinct spatial constraints, thus giving access to a wider dataset for molecular modeling. Finally, by applying recombinant mini-Gs, GTPγS, and Gαs-depleted HEK293 cells to modulate Gs coupling, it is shown that yields of crosslinking increase in the presence of elevated levels of Gs.

The effect of agglomerate integrity and blending formulation on the mechanical properties of whey protein concentrate powder tablets

In this work, the strength of tablets made from mixtures of whey protein concentrate (WPC) powder and different types of sugar was investigated. The agglomerated WPC powder was pneumatically conveyed (lean phase) at three different air speeds of 10, 20 or 30 m/s to simulate the effects of industrial powder transport, resulting in agglomerates with reduced integrity. Conveyed and control WPC powder, and sugar of three different particle size distributions (i.e., granulated, GS; caster, CS and icing sugar, IS) were analysed for microstructure, particle size, moisture, and flowability. Tensile strength of tablets from WPC powder alone or blended with 0.5–10% sugar was tested. Conveying of WPC powder led to a significant increase in tablet strength, (i.e., from failure strength of 1.67 N/mm2 for control tablets to 2.33, 2.11 and 2.11 N/mm2 after conveying at 10, 20 or 30 m/s, respectively), suggesting that the generation of smaller powder particles led to increased mechanical strength of tablets. The addition of sugar also resulted in a significant increase in tablet strength (e.g., failure strength of 2.34, 2.12 and 2.47 N/mm2 at 1.5% addition level of GS, CS and IS, respectively) and strongest tablets were obtained at 1.5–3% sugar addition and by blending with icing sugar. This study demonstrated, for the first time, that conveying and dry blending of whey protein and sugar powders significantly influenced the rheological properties of resultant tablets.

Increased glutamine anabolism sensitizes non-small cell lung cancer to gefitinib treatment

To better understand the resistance mechanism of non-small cell lung cancers (NSCLCs) to gefitinib, the metabolic profiles of gefitinib-resistant A549 cells and gefitinib-sensitive PC-9 cells were analyzed with a metabolomics analytical platform. A549 and PC-9 cells exhibited significant differences in the levels of glutamine-related metabolites. After gefitinib treatment, the glutamine level decreased in A549 cells but showed no change in PC-9 cells. The glutamine consumed by A549 cells was used to generate ATP and glutathione (GSH). As glutamine utilization was suppressed in gefitinib-treated PC-9 cells, the resulting ATP shortage and ROS accumulation led to cell death. The difference in glutamine metabolism was caused by differential changes in the levels of glutamine synthetase (GS, encoded by glutamate-ammonia ligase (GLUL)). GLUL expression was upregulated in gefitinib-sensitive cells, but it was either absent from gefitinib-resistant cells or no significant change was observed in the gefitinib-treated cells. GLUL overexpression in A549 cells significant sensitized them to gefitinib and decreased their invasive capacity. Conversely, knockout GS in PC-9 cells reduced gefitinib sensitivity and enhanced metastasis. Furthermore, the continuous exposure of gefitinib-sensitive HCC827 cells to gefitinib created gefitinib-resistant (GR) HCC827 cells, which exhibited a GLUL deletion and resistance to gefitinib. Thus, GLUL plays a vital role in determining the sensitivity of NSCLCs to gefitinib. Elevated GS levels mediate increased glutamine anabolism, and this novel mechanism sensitizes NSCLCs to gefitinib. The inhibition of glutamine utilization may serve as a potential therapeutic strategy to overcome gefitinib resistance in the clinic.

Differential expression of Annexin 2, SPINK1, and Hsp60 predict progression of prostate cancer through bifurcated WHO Gleason score categories in African American men.

Although studies have observed several markers correlate with progression of prostate cancer (PCa), no specific markers have been identified that accurately predict the progression of this disease, even in African American (AA) men who are generally at higher risk than other ethnic groups. The primary goal of this study was to explore whether three markers could predict the progression of PCa. We investigated protein expression of Annexin 2 (ANX2), serine peptidase inhibitor, kazal type 1(SPINK1)/tumor-associated trypsin inhibitor (TATI), and heat shock protein 60 (Hsp60) in 79 archival human prostate trans-rectal ultrasound (TRUS) biopsy tissues according to a modified World Health Organization (WHO) classification: normal (WHO1a), Gleason Score (GS6 (WHO1b), GS7 subgroups (WHO2 = 3 + 4, WHO3 = 4 + 3), GS8 (WHO4), and GS9-10 (WHO5). AA men aged 41-90 diagnosed from 1990 to 2013 at Howard University were included. Automated staining assessed expression of each biomarker. Spearman correlation assessed the direction and relationship between biomarkers, WHO and modified WHO GS, age, and 5-year survival. A two-tailed t-test and ANOVA evaluated biomarkers expression in relationship to WHO normal and other GS levels, and between WHO GS levels. A logistic and linear regression analysis examined the relationship between biomarker score and WHO GS categories. Kaplan-Meier curves graphed survival. ANX2 expression decreased monotonically with the progression of PCa while expression of SPINK1/TATI and Hsp60 increased but had a more WHO GS-specific effect; SPINK1/TATI differed between normal and GS 2-6 and HSP60 differed between GS 7 and GS 2-6. WHO GS was found to be significantly and negatively associated with ANX2, and positively with SPINK1/TATI and Hsp60 expression. High SPINK1/TATI expression together with the low ANX2 expression at higher GS exhibited a bi-directional relationship that is associated with PCa progression and survival. Importantly, the data reveal that ANX2, and SPINK1/TAT1 highly associate with WHO GS and with the transition from one stage of PrCa to the next in AA men. Future research is needed in biracial and larger population studies to confirm this dynamic relationship between ANX2 and SPINK1 as independent predictors of PCa progression in all men.

Dietary effects of succinic acid on the growth, digestive enzymes, immune response and resistance to ammonia stress of Litopenaeus vannamei

Organic acids acts as an growth promoter and antimicrobial agent in aquaculture. The present study investigated the effects of a natural organic acid - succinic acid (SA) on the growth, digestive enzymes, immune response and resistance to ammonia stress of Litopenaeus vannamei. The shrimps were firstly fed with diets containing different levels of SA: 0% (Control), 0.25% (SA1), 0.50% (SA2), and 1.0% (SA3) (w/w) for 56 days, followed by an acute ammonia stress for 48 h. The results indicated that dietary of SA improved the growth of shrimp, and increased the survival rate of shrimp after ammonia stress for 48 h. The amylase, lipase and pepsin activity increased in hepatopancreas in three SA group, while trypsin activity was only increased in the SA1 and SA2 groups. At 56 d, T-NOS activity, proPO and HSP70 gene expression level increased in the three SA group, PO activity increased in the SA1 and SA2 groups, T-AOC content and Toll gene expression level increased in the SA2 and SA3 groups, Trx and SOD gene expression level increased in the SA2 group, while Imd, GS and GDH gene expression level was no changes. After exposure to ammonia stress for 48 h, immune biochemical parameters (T-AOC and PO) and genes (proPO, HSP70, Trx and GDH) expression level increased in the three SA group, T-NOS activity, Toll, Imd and GS gene expression level increased in the SA2 and SA3 groups, while SOD gene expression level increased in the SA1 and SA2 groups. These results indicated that SA improved growth, enhanced digestive and immune capacities of L. vannamei against ammonia stress, and may be a potential feed additive for shrimp. The optimal dietary supplementation dosage is 0.50% (w/w) in diet.

Assessment of gelsolin level in women with heart disease after menopause

In the current study, Seventy menopausal women have CHD were admitted to the coronary care unit of AL-Sader teaching hospital in AL-najaf AL-Ashraf during the period from January to April/2016 for the ages were ranging from 40 to 69 years old. The samples were divided into three groups (SA 25, UA 22, AMI 23), while the healthy group was composed of 20. The current study indicated a significant decrease (P<0.05)in serum E2 and GS concentration of CHD compared with healthy group. The serum of E2 and GS concentrations showed a significantly decrease (p<0.05) in AMI compare with UA and SA groups of CHD. The result indicated a positive correlation between E2 and GS. Conclusion: The present study concluded that E2 and GS levels were markers for detection and diagnosis of Coronary heart disease in menopausal women.

Water relations and carbohydrate partitioning of four greenhouse-grown olive genotypes under long-term drought

The four olive genotypes exhibited different responses to drought involving leaf drop and g s reductions (broad-leaved genotypes, good leaf hydration); or growth reductions (narrow-leaved genotypes, dehydration tolerance). There was minor effect on carbohydrate levels. Olive plants of broad-leaved ‘Minuta’ (MN) and ‘Nocellara del Belice’ (NB) and narrow-leaved ‘Passulunara’ (PA) and ‘Biancolilla Siracusana’ (BS) were studied to evaluate their responses to drought. In a greenhouse, 2-year-old rooted cuttings were irrigated to field capacity (WW) or with 20% of WW evapotranspiration (DS) for over 3 months. Subsequently, all pots were rewatered to field capacity for 20 days. Gravimetric soil water content (SWC), leaf relative water content (RWC), stomatal conductance (g s), leaf carbohydrates, percentage of leaf drop and shoot elongation were determined throughout the trial. In WW, SWC fluctuated between 80 and 100% of field capacity, whereas in DS, SWC decreased sharply reaching a minimum level around 30–35% of field capacity after 2 months of drought. At this time, drought induced a significant reduction of: (a) RWC in PA and BS, (b) g s in MN, NB, and PA, and (c) shoot elongation (−23%) in PA. Conversely, drought increased leaf drop in all genotypes, especially in MN and NB. RWC and g s levels were mostly restored after rewatering. Initially, drought induced an increase of mannitol and total carbohydrates in MN and a decrease in NB. At more advanced drought stages, mannitol and total carbohydrates decreased in PA and BS. NB exhibited a general increase of the (mannitol + glucose)/sucrose ratio in response to drought. The two broad-leaved genotypes (MN and NB) maintained similar leaf hydration levels in DS and WW plants proving to be generally intolerant to dehydration, whereas the two narrow-leaved genotypes (PA and BS) tolerated a fair degree of dehydration.

Leaf and Root Growth, Carbon and Nitrogen Contents, and Gene Expression of Perennial Ryegrass to Different Nitrogen Supplies

Nitrogen greatly impacts plant growth and development. The objective of this study was to characterize growth, nitrogen use, and gene expression of perennial ryegrass (Lolium perenne) in response to increasing nitrogen supplies. Perennial ryegrass (cv. Inspire) was grown in sand culture and irrigated with a half-Hoagland solution amended with 0, 0.5, 1.0, 2.5, 5.0, and 7.5 mm nitrogen. Leaf tissues were harvested at 10 days (first cutting) and 20 days (second cutting) and roots were harvested at 20 days. The relatively higher N supply (2.0–7.5 mm) resulted in a larger amount of leaf fresh and dry weight but lower root fresh and dry weight, especially for the second cutting. Root:leaf ratio was higher under low N, but lower under the high N treatment. Leaf N content was relatively higher under 2.5, 5, and 7.5 mm N than under the other three treatments, while 2.5 mm N exhibited relatively higher leaf carbon content for both cuttings. Leaf C:N ratio and leaf nitrogen use efficiency (LNUE) decreased with increasing N supplies for the first cutting but were higher under low N (0–1.0 mm) for both cuttings. Leaf C:N ratio and LNUE did not differ among low N and LNUE also remained unchanged among high N for the second cutting. Root N content increased, but the root C:N ratio and root N use efficiency (RNUE) decreased with increasing N supplies, especially under 2.5, 5.0, and 7.5 mm N. Low (0.5 mm), moderate (2.5 mm), and high (7.5 mm) N were chosen to examine the expression level of NR encoding nitrate reductase and GS1b encoding glutamine synthetase. Treatment of 0.5 mm N had higher expression levels of leaf NR than other two treatments for both cuttings and a higher level of leaf GS for the second cutting. Expression of NR in the roots did not vary among treatments but the expression of GS increased under 2.5 and 7.5 mm, compared with the 0.5 mm N. Differential leaf and root growth and physiological responses to low N (0 to 1 mm) and to moderate to high N (2.5 to 7.5 mm) could be used for examining the natural variation of N use in diverse perennial ryegrass populations.

Hand tactile discrimination, social touch and frailty criteria in elderly people: A cross sectional observational study

Frailty is a common syndrome among elderly and sensory decline may exacerbate functional decline. The hand function, the manual dexterity, the performance of the daily living skills and the social interactions are determined, in a large degree, by sensory integrity. However, hand tactile sensory deterioration has been little explored in frailty. We performed a cross sectional observational study with 181 of institutionalized elders. From the initial sample we selected 50 subjects (68–99 years) who met the inclusion/exclusion criteria. Our goals were (1) to analyse the relationship between tactile discrimination (TD) of the hand, avoidance behaviours and attitudes towards social touch (BATST) and phenotype frailty criteria (unintentional weight loss, self-perception of exhaustion, decrease grip strength − GS, slow walking speed, low level of physical activity), (2) to explore whether other variables can contribute to explain the differences between pre-frail and frail elders. The results showed that increasing age is related to decline of TD of the hand (p=0.021) and to decrease in GS (p=0.025); women have significantly lower level of GS (p=0.001); TD decrease is correlated with higher avoidance BATST (p=0.000) and with lower GS (p=0.000); Lower GS corresponds to more avoidance BATST (p=0.003). Hand TD also can differentiate frail and pre-frail elderly subjects in this sample (p=0.037). Decreased TD of the hand may have implications on the functionality and on interpersonal relationships. TD of the hand also explains frailty levels in this sample. Hand TD should be used in assessment and intervention protocols in pre-frail and frail elders.

AMPK is involved in the differential neonatal performance of chicks hatching at different time

We have recently reported that the hatching time may be in relation to the distinct neonatal performance of female chicks. The present study was aimed to investigate the potential involvement of AMPK, an energy sensor which plays a pivotal role in energy homeostasis, in the distinct performance of the spread of hatching time model. As a result, hypothalamic AMPKα1 isoform gene expression was significantly higher in the late hatcher as compared to that of their early counterparts, whereas the total and phosphorylated levels of AMPKα subunit did not differ between the three hatchers. The hypothalamic orexigenic NPY and AgRP mRNA levels were higher in the late hatchers as compared to the early, and that of the middle hatchers was at an intermediate level. However, the anorexigenic POMC and CRH was also higher expressed in the late hatchers as compared to the early hatchers. In the liver, AMPKα2 mRNA level and the phosphorylation ratio of AMPKα was significantly lower in the late hatchers, as compared to their early counterparts. The hepatic phosphorylated GS levels of the late and middle hatchers were lower than that of their early counterparts. The expression of hepatic FTO gene of the late hatchers was significantly higher than that of their early and middle counterparts. Taken together, AMPK may play a significant role in the different neonatal performance of the spread of hatching time model. The central and peripheral AMPK in late hatchers exhibited a pattern of higher energy intake and lower energy expenditure, which resulted in a faster post-hatch growth.

Physiological response of juvenile hop plants to water deficit

This paper evaluates the response on the rate of photosynthesis (Pn), transpiration (E), stomatal conductance (gs) and water use efficiency (WUE) in 15 genotypes of young hop plants (19 BBCH) grown in greenhouses in the conditions of water deficit for the period of 9 days. On the 9th day, the relative content of water in the experimental plants fluctuated between 70.14-75.20%. The levels of Pn and gs evidently dropped in the monitored species as a result of the water deficit. The decrease of Pn in the experimental plants compared with the control group was largest in the Saaz Os. cl. 72 (by 77.5%), Magnum (by 73.3%) and Columbus (by 62.3%). To the contrary, the lowest Pn decrease was noted in the case of genotypes Saaz Late (by 15.7%), Vital (by 23.9%) and Premiant (by 24.2%). All genotypes except for cv. H16 showed an evident decrease of E. Judging by the highest values of WUE, the most effective water management was shown by Premiant, Vital and Saaz Late genotypes. A significant stomatal limitation of photosynthesis due to water stress was identified in the most widely used Czech cultivar, Saaz Os. cl. 72, with low values of stomatal conductance, photosynthetic rate and transpiration.

Stomatal Conductance Is Essential for Higher Yield Potential of C3 Crops

The present review of gas-exchange studies conducted in rainfed or irrigated field conditions clearly indicates that stomatal conductance (gs) of major crops has been inadvertently increased in the last 50 to 80 years as higher yields were being reached through conventional plant breeding. These findings suggest that high gs rates are critical to optimum growth and yield of modern crops, in particular to crop growth rate (CGR) during seed formation and filling. Several hypotheses are presented that may account for this increase. This review also includes studies in which increases in gs were documented for genetically-engineered plants. However, field evaluations of their gas-exchange performance remain sparse. The main finding of this review is that higher rates of gs should be sought, as we forego the usual consideration of crop plants as single organisms losing water, but rather acknowledge that water does exit a crop canopy along a Soil Plant Atmosphere Continuum (SPAC). In non-limiting or moderately-limiting soil water conditions, high yields are generated by an active SPAC that requires sustained levels of gs. In conditions of high evaporative demand, as in summer afternoons, sustained gs allows for cooler canopies with no mid-day depression in photosynthesis as CO2 remains able to diffuse in the leaf through stomata.