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Publication
Journal: PLoS ONE
July/4/2011
Abstract
Pathogenesis-related protein-5 (PR-5) has been implicated in plant disease resistance and its antifungal activity has been demonstrated in some fruit species. However, their roles, especially their interactions with the other defense responses in plant cells, are still not fully understood. In this study, we have cloned and characterized a new PR-5 cDNA named PdPR5-1 from the European plum (Prunus domestica). Expression of PdPR5-1 was studied in different cultivars varying in resistance to the brown rot disease caused by the necrotrophic fungus Monilinia fructicola. In addition transgenic Arabidopsis, ectopically expressing PdPR5-1 was used to study its role in other plant defense responses after fungal infection. We show that the resistant cultivars exhibited much higher levels of transcripts than the susceptible cultivars during fruit ripening. However, significant rise in the transcript levels after infection with M. fructicola was observed in the susceptible cultivars too. Transgenic Arabidopsis plants exhibited more resistance to Alternaria brassicicola. Further, there was a significant increase in the transcripts of genes involved in the phenylpropanoid biosynthesis pathway such as phenylalanine ammonia-lyase (PAL) and phytoalexin (camalexin) pathway leading to an increase in camalexin content after fungal infection. Our results show that PdPR5-1 gene, in addition to its anti-fungal properties, has a possible role in activating other defense pathways, including phytoalexin production.
Publication
Journal: Resuscitation
September/28/2009
Abstract
BACKGROUND
The quality of life support delivered during cardiopulmonary resuscitation affects outcomes. However, little data exist regarding the quality of resuscitation delivered to children and factors associated with adherence to American Heart Association (AHA) resuscitation guidelines.
METHODS
Pediatric residents from an academic, tertiary care hospital.
METHODS
Prospective, observational cohort study of residents trained in the AHA PALS 2000 guidelines managing a high-fidelity mannequin simulator programmed to develop pulseless ventricular tachycardia (PVT).
METHODS
Proportion of residents who: (1) started compressions in < or =1min from onset of PVT, (2) defibrillated in < or =3min and (3) factors associated with time to defibrillation.
RESULTS
Seventy of eighty (88%) residents participated. Forty-six of seventy (66%) failed to start compressions within 1min of pulselessness and 23/70 (33%) never started compressions. Only 38/70 (54%) residents defibrillated the mannequin in < or =3min of onset of PVT. There was no significant difference in time elapsed between onset of PVT and defibrillation by level of post-graduate training. However, residents who had previously discharged a defibrillator on either a patient or a simulator compared to those who had not were 87% more likely to successfully defibrillate the mannequin at any point in time (hazard ratio 1.87, 95% CI: 1.08-3.21, p=0.02).
CONCLUSIONS
Pediatric residents do not meet performance standards set by the AHA. Future curricula should focus training on identified defects including: (1) equal emphasis on "airway and breathing" and "circulation" and (2) hands-on training with using and discharging a defibrillator in order to improve safety and outcomes.
Publication
Journal: Plant Physiology and Biochemistry
August/12/2009
Abstract
Plants typically respond to environmental stresses by inducing antioxidants as a defense mechanism. As a number of these are also phytochemicals with health-promoting qualities in the human diet, we have used mild environmental stresses to enhance the phytochemical content of lettuce, a common leafy vegetable. Five-week-old lettuce (Lactuca sativa L.) plants grown in growth chambers were exposed to mild stresses such as heat shock (40 degrees C for 10 min), chilling (4 degrees C for 1d) or high light intensity (800 micromolm(-2)s(-1) for 1d). In response to these stresses, there was a two to threefold increase in the total phenolic content and a significant increase in the antioxidant capacity. The concentrations of two major phenolic compounds in lettuce, chicoric acid and chlorogenic acid, increased significantly in response to all the stresses. Quercetin-3-O-glucoside and luteolin-7-O-glucoside were not detected in the control plants, but showed marked accumulations following the stress treatments. The results suggest that certain phenolic compounds can be induced in lettuce by environmental stresses. Of all the stress treatments, high light produced the greatest accumulation of phenolic compounds, especially following the stress treatments during the recovery. In addition, key genes such as phenylalanine ammonia-lyase (PAL), l-galactose dehydrogenase (l-GalDH), and gamma-tocopherol methyltransferase (gamma-TMT) involved in the biosynthesis of phenolic compounds, ascorbic acid, and alpha-tocopherol, respectively, were rapidly activated by chilling stress while heat shock and high light did not appear to have an effect on the expression of PAL and gamma-TMT. However, l-GalDH was consistently activated in response to all the stresses. The results also show that these mild environmental stresses had no adverse effects on the overall growth of lettuce, suggesting that it is possible to use mild environmental stresses to successfully improve the phytochemical content and hence the health-promoting quality of lettuce with little or no adverse effect on its growth or yield.
Publication
Journal: PLoS ONE
October/21/2013
Abstract
BACKGROUND
Lycoris aurea, also called Golden Magic Lily, is an ornamentally and medicinally important species of the Amaryllidaceae family. To date, the sequencing of its whole genome is unavailable as a non-model organism. Transcriptomic information is also scarce for this species. In this study, we performed de novo transcriptome sequencing to produce the first comprehensive expressed sequence tag (EST) dataset for L. aurea using high-throughput sequencing technology.
RESULTS
Total RNA was isolated from leaves with sodium nitroprusside (SNP), salicylic acid (SA), or methyl jasmonate (MeJA) treatment, stems, and flowers at the bud, blooming, and wilting stages. Equal quantities of RNA from each tissue and stage were pooled to construct a cDNA library. Using 454 pyrosequencing technology, a total of 937,990 high quality reads (308.63 Mb) with an average read length of 329 bp were generated. Clustering and assembly of these reads produced a non-redundant set of 141,111 unique sequences, comprising 24,604 contigs and 116,507 singletons. All of the unique sequences were involved in the biological process, cellular component and molecular function categories by GO analysis. Potential genes and their functions were predicted by KEGG pathway mapping and COG analysis. Based on our sequence analysis and published literatures, many putative genes involved in Amaryllidaceae alkaloids synthesis, including PAL, TYDC OMT, NMT, P450, and other potentially important candidate genes, were identified for the first time in this Lycoris. Furthermore, 6,386 SSRs and 18,107 high-confidence SNPs were identified in this EST dataset.
CONCLUSIONS
The transcriptome provides an invaluable new data for a functional genomics resource and future biological research in L. aurea. The molecular markers identified in this study will provide a material basis for future genetic linkage and quantitative trait loci analyses, and will provide useful information for functional genomic research in future.
Publication
Journal: Journal of Biological Chemistry
August/14/1994
Abstract
In response to growth, metabolic, and other signals, eukaryotic cells regulate protein biosynthesis through post-translational mechanisms which target the alpha subunit of eukaryotic initiation factor-2 (eIF-2 alpha). Previous efforts to study transcriptional mechanisms underlying this regulation identified a novel transcription factor (alpha-Pal) for the eIF-2 alpha gene. To gain insights into the overall biological function of alpha-Pal, we cloned its cDNA. Sequence analysis of the encoded protein reveals that alpha-Pal is a putative bZIP transcription factor. Surprisingly, both the protein sequence and the DNA-recognition site (TGCGCATGCGCA) of this human protein are strongly homologous to those of two evolutionarily distant developmental transcription factors, P3A2 and ewg. Since P3A2 directs territory-specific transcription of muscle genes in sea urchin embryos, and ewg apparently directs transcription of flight muscle and neuronal genes in Drosophila embryos, it is likely that alpha-Pal directs similar gene transcription during human embryogenesis. In other studies, we also identified genes containing alpha-Pal-binding sequences as those involved in cellular proliferation, or the growth-responsive metabolic pathways, energy transduction, translation, and DNA replication/repair. Such data suggest that alpha-Pal also functions to modulate the transcription of metabolic genes required for cellular growth.
Publication
Journal: Journal of Clinical Periodontology
January/5/2000
Abstract
In the present prospective clinical trial, the effect of various regenerative procedures performed at sites with angular bone defects were evaluated. The main outcome variable was probing attachment alteration.
METHODS
40 subjects, aged 32-61 years participated. They met the following inclusion criteria: (i) presence of generalized, advanced periodontal tissue destruction; (ii) presence of 2 similar, contralateral, angular bone defects (experimental sites) located in either the maxilla or the mandible; (iii) the defect site must exhibit a probing pocket depth (PPD) of>> or = 6 mm, a probing attachment level (PAL) of>> or = 7 mm, and a depth of the intrabony component of>> or = 3 mm. All subjects had a good oral hygiene standard, were in good general health and did not use any medication. Prior to the start of the study, all subjects received non-surgical treatment for periodontal disease. Baseline clinical measurements (plaque, gingivitis, PPD, PAL and soft tissue recession) of the selected experimental sites were obtained 6 months after the completion of basic therapy. The 40 subjects were randomly divided into 4 treatment groups including 10 subjects each: 3 membrane groups and one Emdogain group. 1 h before surgery, the patients were given 3 g of Amoxicillin. No other antibiotics were prescribed. The test and control sites were treated during the same surgical session. Full thickness flaps were elevated and the exposed root surfaces were planed. Membrane placement: The root surface was rinsed with saline. A barrier membrane (Guidor or Resolut or Periodontal (e-PTFE) material) was positioned to cover the defect and the adjacent 2-3 mm of bone tissue. The control treatment was identical to the test treatment with the exception of barrier placement. Emdogain placement: The exposed root surfaces at both the test and control sites were, during a 2-min period, conditioned with a 24% EDTA gel. Emdogain was applied to the exposed root surface of the test site. In the control site, the vehicle, the PGA gel, was used as placebo control. The flaps were closed and sutured to obtain a complete coverage of the intrabony defect.
RESULTS
Re-examinations, which were performed 12 months after surgery, disclosed that regenerative therapy, including either the use of barrier membranes or application of enamel matrix proteins to an instrumented root surface in an angular, intrabony defect, enhanced outcome variables such as probing pocket depth and probing attachment gain. It was furthermore demonstrated that clinical improvements were better at sites with deep, than at sites with shallow, intrabony defects.
CONCLUSIONS
The 4 regenerative modalities tested appeared to be equally effective in terms of PPD reduction and PAL gain, and superior to open flap curettage alone.
Publication
Journal: Journal of Medical Microbiology
August/9/2006
Abstract
In a search for novel bioactive cell surface structures of periodontal pathogens, it was found that sera from two patients with Actinobacillus actinomycetemcomitans-associated infections reacted strongly at 17 kDa on immunoblots of A. actinomycetemcomitans outer-membrane protein (OMP) preparations. The 17 kDa antigen was also recognized by anti-CsgA (Escherichia coli curli major subunit) antibody. The 17 kDa A. actinomycetemcomitans protein was identified as peptidoglycan-associated lipoprotein (PAL; AaPAL) by two-dimensional immunoblotting and subsequent sequence analysis by mass spectrometry and bioinformatics tools. AaPAL was an OMP and a lipoprotein, and it had an OmpA-like domain. In a group of middle-aged subjects (n = 26), serum reactivity to AaPAL was associated with the presence of periodontitis but not with the oral detection of A. actinomycetemcomitans. Both human sera and rabbit antisera against three different types of antigens, the gel-purified AaPAL, A. actinomycetemcomitans whole-cell antigens, and CsgA, recognized putative PALs of oral haemophili in addition to AaPAL. The results demonstrated that the novel AaPAL is a conserved bacterial lipoprotein. It is expressed in vivo and is strongly immunoreactive. The antigenic cross-reactivity found between AaPAL and oral haemophili may enhance local and systemic immuno-inflammatory reactions in periodontitis.
Publication
Journal: Cancer Letters
December/21/2000
Abstract
The recently identified decoy receptor 3 (DcR3) binds to FasL and inhibits FasL-induced apoptosis, and is considered to play a role in the immune escape system of neoplastic cells. To examine the involvement of DcR3 in the immune evasions of virus-associated lymphoma, we analyzed the amplification and expression of DcR3, using dot blot and in situ hybridization (ISH), in 45 cases, which included 17 cases with Epstein-Barr virus (EBV)-associated lymphoma (seven pyothorax-associated B-cell lymphomas (PAL); ten natural killer lymphoma (NKL)), seven cases with adult T-cell leukemia lymphoma (ATLL), 13 Hodgkin's disease (eight EBV-associated cases; five non-EBV-associated cases), and eight control cases (three reactive lymphadenopathy; five non-EBV-associated-B-cell lymphoma). EBV-associated PAL and NKL exhibited DcR3 amplification and expression in lymphoma cells. ATLL also showed DcR3 expression and amplification. The cases with DcR3 amplification showed DcR3 expression; however, the expression was confined in the neoplastic cells, but not in the reactive cells. In Hodgkin's disease (HD), DcR3 was expressed only in Hodgkin and Reed-Sternberg giant (H-RS) cells. However, DcR3 was not expressed or amplified in reactive lymphadenopathy. Non-EBV-associated B-cell lymphoma also rarely expressed DcR3, and showed no amplification except in two cases, in which rare expression was present. Our results suggest that EBV and HTLV-I probably use DcR3 to escape from the immune system during lymphomagenesis, or virus-infected lymphoma cells with DcR3 expression might be selected in the multistep tumorigenesis.
Publication
Journal: Journal of Biological Chemistry
June/24/1998
Abstract
To understand what processes contribute to the agonist-induced internalization of subtypes of muscarinic acetylcholine receptors, we analyzed the role of arrestins. Whereas the m2 mAChR has been shown to undergo augmented internalization when arrestins 2 and 3 are overexpressed (Pals-Rylaarsdam, R., Gurevich, V. V., Lee, K. B., Ptasienski, J. A., Benovic, J. L., and Hosey, M. M. (1997) J. Biol. Chem. 272, 23682-23689), the agonist-induced internalization of m1, m3, and m4 mAChRs was unchanged when arrestins 2 or 3 were overexpressed in transiently transfected HEK-tsA201 cells. Furthermore, when a dominant-negative arrestin was used to interrupt endogenous arrestin function, there was no change in the internalization of the m1, m3, and m4 mAChR whereas the internalization of the beta2 adrenergic receptor was completely blocked. Wild-type and GTPase-deficient dominant-negative dynamin were used to determine which endocytic machinery played a role in the endocytosis of the subtypes of mAChRs. Interestingly, when dynamin function was blocked by overexpression of the GTPase-deficient dynamin, agonist- induced internalization of the the m1, m3, and m4 mAChRs was suppressed. These results suggested that the internalization of the m1, m3, and m4 mAChRs occurs via an arrestin-independent but dynamin-dependent pathway. To ascertain whether domains that confer arrestin sensitivity and dynamin insensitivity could be functionally exchanged between subtypes of mAChRs, chimeric m2/m3 receptors were analyzed for their properties of agonist-induced internalization. The results demonstrated that the third intracellular loop of the m2 mAChR conferred arrestin sensitivity and dynamin insensitivity to the arrestin-insensitive, dynamin-sensitive m3 mAChR while the analogous domain of the m3 mAChR conferred arrestin resistance and dynamin sensitivity to the previously arrestin-sensitive, dynamin-insensitive m2 mAChR.
Publication
Journal: PLoS ONE
July/16/2013
Abstract
BACKGROUND
Physical inactivity is a growing public health problem, and the fourth leading risk factor for global mortality. Conversely, indigenous populations living traditional lifestyles reportedly engage in vigorous daily activity that is protective against non-communicable diseases. Here we analyze physical activity patterns among the Tsimane, forager-horticulturalists of Amazonian Bolivia with minimal heart disease and diabetes. We assess age patterns of adult activity among men and women, test whether modernization affects activity levels, and examine whether nascent obesity is associated with reduced activity.
RESULTS
A factorial method based on a large sample of behavioral observations was employed to estimate effects of age, sex, body mass index, and modernization variables on physical activity ratio (PAR), the ratio of total energy expenditure to basal metabolic rate. Accelerometry combined with heart rate monitoring was compared to the factorial method and used for nighttime sampling. Tsimane men and women display 24 hr physical activity level (PAL) of 2.02-2.15 and 1.73-1.85, respectively. Little time was spent "sedentary", whereas most activity was light to moderate, rather than vigorous. Activity peaks by the late twenties in men, and declines thereafter, but remains constant among women after the early teens. Neither BMI, fat free mass or body fat percentage are associated with PAR. There was no negative effect of modernization on physical activity.
CONCLUSIONS
Tsimane display relatively high PALs typical of other subsistence populations, but of moderate intensity, and not outside the range of developed populations. Despite rapidly increasing socioeconomic change, there is little evidence that total activity has yet been affected. Overweight and obesity are more prevalent among women than men, and Spanish fluency is associated with greater obesity in women. The lack of cardiovascular disease among Tsimane is unlikely caused by activity alone; further study of diet, food intake and infectious disease is needed.
Publication
Journal: Molecular Microbiology
July/15/2002
Abstract
Several proteins of the Tol/Pal system are required for group A colicin import into Escherichia coli. Colicin A interacts with TolA and TolB via distinct regions of its N-terminal domain. Both interactions are required for colicin translocation. Using in vivo and in vitro approaches, we show in this study that colicin A also interacts with a third component of the Tol/Pal system required for colicin import, TolR. This interaction is specific to colicins dependent on TolR for their translocation, strongly suggesting a direct involvement of the interaction in the colicin translocation step. TolR is anchored to the inner membrane by a single transmembrane segment and protrudes into the periplasm. The interaction involves part of the periplasmic domain of TolR and a small region of the colicin A N-terminal domain. This region and the other regions responsible for the interaction with TolA and TolB have been mapped precisely within the colicin A N-terminal domain and appear to be arranged linearly in the colicin sequence. Multiple contacts with periplasmic-exposed Tol proteins are therefore a general principle required for group A colicin translocation.
Publication
Journal: Journal of Morphology
November/30/1976
Abstract
A staging system has been devised for normal regeneration from the upper arm in the mature axolotl. It consists of seven externally definable stages: (1) Wound healing (WH): (2) Dedifferentiation (DD); (3) Early bud (EB); (4) Medium bud (MB); (5) Late bud (LB); (6) Palette (Pal), and (7) Digital outgrowth (DO). Serial histological sections of 38 regenerating limbs were used to correlate gross stages with microscopic events in the regenerative process.
Publication
Journal: Journal of Histochemistry and Cytochemistry
November/1/2004
Abstract
The development of peripheral lymphoid tissues requires a series of cognate interactions between hemopoietic and stromal cell populations, including reticular fibroblasts, which form the mesenchymal scaffolding of distinct tissue compartments. Here we describe the formation of different fibroblastic domains in the mouse spleen white pulp by using two new rat monoclonal antibodies (MAbs). In the white pulp, MAb IBL-10 labels both T- and B-cell zone reticular elements at various intensities. The IBL-10hi subset was found primarily at the edge between the peripheral part of the PALS and follicles, and the IBL-10lo compartment was distributed evenly within the white pulp. The IBL-10hi subset appeared during the first 2 postnatal weeks and was absent in SCID mice. The white pulp fibroblast subset identified with MAb IBL-11 had a different tissue distribution and kinetics of ontogeny, with an appearance overwhelmingly restricted to the PALS and a narrow rim at the edge of the follicular border area toward the marginal zone. The appearance of IBL-11-positive reticular cells was delayed compared with that of the IBL-10lo-positive subset. The formation was independent of the influence of antigen receptor-bearing lymphocytes, as evidenced by the presence of IBL-11-positive fibroblasts in SCID mice. By transferring various lymphocyte subsets into SCID mice, partial compartmentalization of the white pulp fibroblasts could be induced, indicating that these mesenchymal fibroblast precursors retain their ability to differentiate upon encountering mature T- or B-cells.
Publication
Journal: Southeast Asian Journal of Tropical Medicine and Public Health
March/8/2000
Abstract
Chemical pesticides are still commonly used in Thailand for control of agricultural pests and disease vectors. Organophosphates, carbamates and synthetic pyrethroids are commonly used for agricultural purposes, whereas synthetic pyrethroids have become more popular and predominate for public health use. The genetic selection of insecticide resistance (whether physiological, biochemical or behavioral) in pests and disease vectors has been extensively reported worldwide (Brown and Pal, 1971). The long-term intensive use of chemical pesticides to control insect pests and disease vectors is often cited as the reason behind the development of insecticide resistance in insect populations. Unfortunately, reliable information on vector resistance patterns to pesticides in Thailand is sparse because of a remarkable shortage of carefully controlled, systematic studies. This review gathers useful information on what is presently known about disease vector resistance to chemical pesticides in Thailand and provides some possible management strategies when serious insecticide resistance occurs.
Publication
Journal: Medicine and Science in Sports and Exercise
November/7/1995
Abstract
We examined the ability of the Tritrac-R3D to estimate daily energy expenditure (EE) and characterize the physical activity patterns of free-living humans. Daily EE was estimated by the Tritrac, a 3-d physical activity log (PAL), and a 7-d recall (SDR). Digital storage of activity data by the Tritrac allowed us to tabulate the number of minutes the monitor recorded EE at specific activity intensities. Twenty-five men and women (mean age and body mass 26.7 yr, 72.5 kg) wore the monitor for 7 d. The Tritrac significantly underestimated daily EE compared with the PAL and SDR, 2552.7 vs 2915.5 kcal.d-1 and 2530.0 vs 2840.3 kcal.d-1, respectively (both, P < 0.01). Correlations between the Tritrac and PAL and the SDR were r = 0.82 and r = 0.77 (both, P < 0.001). Compared with the PAL, the Tritrac overestimated time accumulated in sedentary activities (862.7 vs 827.2 min.d-1) but underestimated time accumulated in active behaviors (37.5 vs 78.0 min.d-1). In conclusion, these data suggest the Tritrac ranks activity levels similarly to the PAL and SDR but it significantly underestimates free-living energy expenditure.
Publication
Journal: PLoS ONE
May/6/2013
Abstract
BACKGROUND
Objectively measuring daily physical activity (PA) using an accelerometer is a relatively expensive and time-consuming undertaking. In routine clinical practice it would be useful to estimate PA in patients with chronic obstructive pulmonary disease (COPD) with more simple methods.
OBJECTIVE
To evaluate whether PA can be estimated by simple tests commonly used in clinical practice in patients with COPD.
METHODS
The average number of steps per day was measured for 7 days with a SenseWear Pro™ accelerometer and used as gold standard for PA. A physical activity level (PAL) of <1.4 was considered very inactive. Univariate and multivariate analyses were used to examine the relationship between the 6-minute walking distance (6MWD), the number of stands in the Sit-to-Stand Test (STST), hand-grip strength and the total energy expenditure as assessed by the Zutphen Physical Activity Questionnaire (TEE(ZPAQ)). ROC curve analysis was used to identify patients with an extremely inactive lifestyle (PAL<1.4).
RESULTS
In 70 patients with COPD (21 females) with a mean [SD] FEV(1) of 43.0 [22.0] %predicted, PA was found to be significantly and independently associated with the 6MWD (r = 0.69, 95% CI 0.54 to 0.80, p<0.001), STST (r = 0.51, 95% CI 0.31 to 0.66, p = 0.001) and TEEZPAQ (r = 0.50, 95% CI 0.30 to 0.66, p<0.001) but not with hand-grip strength. However, ROC curve analysis demonstrated that these tests cannot be used to reliably identify patients with an extremely inactive lifestyle.
CONCLUSIONS
In patients with COPD simple tests such as the 6-Minute Walk Test, the Sit-to-Stand Test and the Zutphen Physical Activity Questionnaire cannot be used to reliably predict physical inactivity.
Publication
Journal: Plant Physiology
June/28/2010
Abstract
The isoflavonoid conjugates medicarpin-3-O-glucoside-6''-O-malonate (MGM), afrormosin-7-O-glucoside (AG), and afrormosin-7-O-glucoside-6''-O-malonate (AGM) were isolated and characterized from cell suspension cultures of alfalfa (Medicago sativa L.), where they were the major constitutive secondary metabolites. They were also found in alfalfa roots but not in other parts of the plant. The phytoalexin medicarpin accumulated rapidly in suspension cultured cells treated with elicitor from Colletotrichum lindemuthianum, and this was subsequently accompanied by an increase in the levels of MGM. In contrast, net accumulation of afrormosin conjugates was not affected by elicitor treatment. Labeling studies with [(14)C]phenylalanine indicated that afrormosin conjugates were the major de novo synthesized isoflavonoid products in unelicited cells. During elicitation, [(14)C]phenylalanine was incorporated predominantly into medicarpin, although a significant proportion of the newly synthesized medicarpin was also conjugated. Treatment of (14)C-labeled, elicited cells with l-alpha-aminooxy-beta-phenylpropionic acid, a potent inhibitor of PAL activity in vivo, resulted in the initial appearance of labeled medicarpin of very low specific activity, suggesting that the phytoalexin could be released from a preformed conjugate under these conditions. Our data draw attention to the involvement of isoflavone hydroxylases during the constitutive and elicitor-induced accumulation of isoflavonoids and their conjugates in alfalfa cell cultures.
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Publication
Journal: Plant Journal
August/10/2008
Abstract
RNA-directed RNA-polymerases (RdRs) are essential in small interfering RNA (siRNA) biogenesis and appear to be functionally specialized. We examined the consequences of silencing RdR2 in Nicotiana attenuata with a field release, and transcriptional, two-dimensional proteomic and metabolite analyses. NaRdR2-silenced plants (irRdR2) had large reductions (46% of wild type) in 22-24-nt small RNAs (smRNAs), and smaller reductions (35, 23 and 26% of wild type) in the 19-21, 25-27 and 28-30-nt smRNAs, respectively. When planted into their native habitats in the Great Basin Desert, irRdR2 plants had impaired growth and reproductive output, which were associated with reduced levels of leaf phenolics (rutin and 4'-chlorogenic acid) and MYB and PAL transcripts, but were unaffected in their herbivore resistance. These phenotypes were confirmed in glasshouse experiments, but only when irRdR2 plants were grown with UV-B radiation. irRdR2 plants had wild-type levels of elicited phytohormones and resistance to Manduca sexta attack, but when exposed to UV-B, had reduced growth, fitness, levels of MYB and PAL transcripts, and phenolics. Proteins related to protection against oxidative and physiological stresses, chromatin remodeling and transcription were also downregulated. Silencing the MYB gene by virus-induced gene silencing (VIGS) in wild-type plants reduced levels of PAL transcripts and phenolics, as it did in UV-exposed irRdR2 plants. Bioinformatic analysis revealed that genes involved in phenylpropanoid biosynthesis contained a large number of smRNA binding motives, suggesting that these genes are targets of smRNAs. We conclude that although NaRdR2 transcripts are upregulated in response to both UV-B and herbivore elicitation, the responses they regulate have been tailored to provide protection from UV-B radiation.
Publication
Journal: Planta
November/10/2015
Abstract
Salicylic acid (SA) is an important plant hormone, and its exogenous application can induce tolerance to multiple environmental stresses in plants. In this study, we examine the potential involvement of endogenous SA in response to chilling in cucumber (Cucumis sativus L.) seedlings. A low temperature of 8 °C induces a moderate increase in endogenous SA levels. Chilling stimulates the enzymatic activities and the expression of genes for phenylalanine ammonia-lyase (PAL) and benzoic acid-2-hydroxylase rather than isochorismate synthase. This indicates that the PAL enzymatic pathway contributes to chilling-induced SA production. Cucumber seedlings pretreated with SA biosynthesis inhibitors accumulate less endogenous SA and suffer more from chilling damage. The expression of cold-responsive genes is also repressed by SA inhibitors. The reduction in stress tolerance and in gene expression can be restored by the exogenous application of SA, confirming the critical roles of SA in chilling responses in cucumber seedlings. Furthermore, the inhibition of SA biosynthesis under chilling stress results in a prolonged and enhanced hydrogen peroxide (H2O2) accumulation. The application of exogenous SA and the chemical scavenger of H2O2 reduces the excess H2O2 and alleviates chilling injury. In contrast, the protective effects of SA are negated by foliar spraying with high concentrations of H2O2 and an inhibitor of the antioxidant enzyme. These results suggest that endogenous SA is required in response to chilling stress in cucumber seedlings, by modulating the expression of cold-responsive genes and the precise induction of cellular H2O2 levels.
Publication
Journal: FEBS Letters
September/4/2013
Abstract
We report a novel regulatory mechanism by which reactive oxygen species (ROS) regulate fumonisin B1 (FB1)-induced cell death. We found that FB1 induction of light-dependent ROS production promoted the degradation of GFP-labeled chloroplast proteins and increased phenylalanine ammonia lyase (PAL) activity, PALPAL activity, PALPAL inhibitor significantly blocked FB1-induced lesion formation and SA increase. Our results demonstrate that light-dependent ROS accumulation stimulates the degradation of chloroplastic proteins and up-regulates PAL-mediated SA synthesis, thus promoting FB1-induced light-dependent cell death.
Publication
Journal: Clinical Oral Implants Research
April/27/2005
Abstract
The purpose of this randomized clinical trial was to compare the clinical outcome of two different surgical approaches for the treatment of peri-implantitis. Seventeen patients with ITI(R) implants were included consecutively over a period of 5 years. The patients were randomized with a lottery assignment. Ten patients were treated with resective surgery and modification of surface topography (test group). The remaining seven patients were treated with resective surgery only (control group). Clinical parameters (suppuration, modified plaque index - mPI, modified bleeding index - mBI, probing pocket depth - PPD, pseudopocket - DIM, mucosal recession - REC, probing attachment level - PAL) were recorded at baseline, as well as 6, 12, 24 and 36 months after treatment. The cumulative survival rate for the implants of the test group was 100% after 3 years. After 24 months, two hollow-screw implants of control group were removed because of mobility. Consequently, the cumulative survival rate was 87.5%. The recession index in the control group was significantly lower than in the test group at 24 months (Student's t-value of -2.14). On the contrary, control group showed higher PPD, PAL and mBI indexes than test group (Student's t-values of +5.5, +2.4 and +9.61, respectively). The PPD and mBI indexes for the implants of the control group were significantly higher at baseline than 24 months later (Student's t-values of +3.18 and +3.33, respectively). Recession and PAL indexes resulted in values significantly lower than baseline (Student's t-values of -4.62 and -2.77, respectively). For the implants of the test group PPD and mBI indexes were significantly higher at baseline than 36 months after (Student's t-values of +11.63 and +16.02, respectively). Recession index resulted in values significantly lower at baseline (Student's t-value of -5.05). No statistically significant differences were found between PAL index measurement at baseline and 36 months later (Student's t-value of +0.89). In conclusion, resective therapy associated with implantoplasty seems to influence positively the survival of oral implants affected by inflammatory processes.
Publication
Journal: Ophthalmic and Physiological Optics
June/17/2009
Abstract
OBJECTIVE
To evaluate the effectiveness of progressive addition lenses (PALs), with a near addition of +1.50 D, on the progression of myopia in Chinese children.
METHODS
We enrolled 178 Chinese juvenile-onset acquired myopes (aged 7-13 years, -0.50 to -3.00 D spherical refractive error), who did not have moderately or highly myopic parents, for a 2-year prospective study. They were randomly assigned to the PAL group or single vision (SV) group. Primary measurements, which included myopia progression and ocular biometry, were performed every 6 months. Treatment effect was adjusted for important covariates, by using a multiple linear regression model.
RESULTS
One hundred and forty-nine subjects (75 in SV and 74 in PAL) completed the 2-year study. The myopia progression (mean +/- S.D.) in the SV and PAL groups was -1.50 +/- 0.67 and -1.24 +/- 0.56 D, respectively. This difference of 0.26 D over 2 years was statistically significant (p = 0.01). The lens type (p = 0.02) and baseline spherical equivalent refraction (p = 0.05) were significant contributing factors to myopia progression. Mean increase in the depth of vitreous chamber was 0.70 +/- 0.40 and 0.59 +/- 0.24 mm, respectively. This difference of 0.11 mm was statistically significant (p = 0.04). Age (p < 0.01) was the only contributing factor to the elongation of vitreous chamber. Different near phoria (p < 0.01) and gender (p = 0.02) caused different treatment effects when wearing SV lenses. However, there were no factors found to influence the treatment effect of wearing PALs.
CONCLUSIONS
Compared with SV lenses, myopia progression was found to be retarded by PALs to some extent in Chinese children without moderately or highly myopic parents, especially for subjects with near esophoria or females.
Publication
Journal: Journal of Clinical Periodontology
August/30/1998
Abstract
48 adult patients with untreated periodontitis harboring subgingival Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis as assessed by PCR were randomly assigned to receive full-mouth scaling alone (control) or scaling with systemic metronidazole plus amoxicillin and supragingival irrigation with chlorhexidine digluconate (test). In patients harboring A. actinomycetemcomitans intraorally at baseline, the adjunctive antimicrobial therapy resulted in a significantly higher incidence of probing attachment level (PAL) gain of 2 mm or more compared to scaling alone over 12 months (p<0.05). In addition, suppression of A. actinomycetemcomitans in subgingival plaque below detectable levels was associated with an increased incidence of PAL gain. In contrast, patients initially harboring P. gingivalis but not A. actinomycetemcomitans in the oral cavity showed a significantly higher incidence of PAL loss following adjunctive antimicrobial therapy compared to scaling alone (p<0.05). When the presence of pathogens at baseline was disregarded in the analysis, adjunctive antimicrobial therapy did not significantly enhance clinical treatment outcome. The results indicated that adults with untreated periodontitis harboring A. actinomycetemcomitans may benefit from the adjunctive antimicrobial therapy for a minimum of 12 months, whereas, the regimen may adversely affect the clinical treatment outcome of patients harboring P. gingivalis but not A. actinomycetemcomitans.
Publication
Journal: Plant Physiology
June/28/2010
Abstract
Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) is involved in the lignification of pine suspension cultures in response to an elicitor prepared from an ectomycorrhizal fungus. To elucidate the molecular basis of this response, PAL was purified to homogeneity from jack pine (Pinus banksiana) suspension cultures using anion-exchange and chromatofocussing fast protein liquid chromatography. Physical characterization of the enzyme revealed that pine PAL was similar to PAL from other plant sources. Pine PAL had a pH optimum of 8.8, an isoelectric point of 5.75, and a native molecular mass of 340 kilodaltons. The enzyme appears to be a tetramer composed of 77 kilodalton subunits. Chromatographic and western blot analyses were used to identify possible isoenzymic changes in pine PAL in response to elicitation and to determine the nature of the increase in PAL activity associated with inducible lignification in these cultures. Only one species of PAL was detected in P. banksiana cell cultures and increased quantities of this protein were correlated with the enhanced enzyme activity observed in elicited cultures. P. banksiana PAL was not feedback-inhibited by a wide range of phenolic compounds at micromolar concentrations, including the reaction product cinnamic acid. Our data suggest that a different set of metabolic and molecular controls must be in place for the regulation of PAL in pine.
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