Ppt

Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by Ppt

  • ppt salinity

  • Selected Abstracts


    Oestrogen receptor-alpha activation augments post-exercise myoblast proliferation

    ACTA PHYSIOLOGICA, Issue 1 2010
    A. Thomas
    Abstract Aim:, Our laboratory has shown that oestrogen acts to augment myoblast (satellite cell) activation, proliferation and total number and that this may occur through an oestrogen receptor (OR)-mediated mechanism. The purpose of this study was to further investigate the mechanism of oestrogen influence on augmentation of post-exercise myoblast numbers through use of a specific OR-, agonist, propyl pyrazole triol (PPT). Methods:, Ovariectomized rats were used (n = 64) and separated into four groups: sham, oestrogen supplemented, agonist supplemented, and a combined oestrogen and agonist supplemented group. These groups were further subdivided into control (unexercised) and exercise groups. Surgical removal of white vastus and soleus muscles was performed 72 h post-exercise. Muscle samples were immunostained for the myoblast markers Pax7 and MyoD. Results:, A significant increase in total (Pax7-positive) and activated (MyoD-positive) myoblasts was found in all groups post-exercise. A further significant augmentation of total and activated myoblasts occurred in oestrogen supplemented, agonist supplemented and the combined oestrogen and agonist supplemented groups post-exercise in white vastus and soleus muscles relative to unsupplemented animals. Conclusion:, These results demonstrate that both oestrogen and the specific OR-, receptor agonist, PPT, can significantly and to similar degrees augment myoblast number and activation following exercise-induced muscle damage. This suggests that oestrogen acts through an OR-mediated mechanism to stimulate myoblast proliferation following exercise, with OR-, playing a primary role. [source]


    Historical review of sample preparation for chromatographic bioanalysis: pros and cons

    DRUG DEVELOPMENT RESEARCH, Issue 3 2007
    Min S. Chang
    Abstract Sample preparation is a major task in a regulated bioanalytical laboratory. The sample preparation procedure significantly impacts assay throughput, data quality, analysis cost, and employee satisfaction. Therefore, selecting and optimizing an appropriate sample preparation method is essential for successful method development. Because of our recent expertise, this article is focused on sample preparation for high-performance liquid chromatography with mass spectrometric detection. Liquid chromatography with mass spectrometric detection (LC-MS) is the most common detection technique for small molecules used in regulated bioanalytical laboratories. The sample preparation technologies discussed are pre-extraction and post-extraction sample processing, protein precipitation (PPT), liquid,liquid extraction (LLE), offline solid-phase extraction (SPE), and online solid-phase extraction. Since all these techniques were in use for more than two decades, numerous applications and variations exist for each technique. We will not attempt to categorize each variation. Rather, the development history, a brief theoretical background, and selected references are presented. The strengths and the limitations of each method are discussed, including the throughput improvement potential. If available, illustrations from presentations at various meetings by our laboratory are used to clarify our opinion. Drug Dev Res 68:107,133, 2007. ©2007 Wiley-Liss, Inc. [source]


    Side-to-side differences in pressure pain thresholds and pericranial muscle tenderness in strictly unilateral migraine

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2008
    C. Fernández-de-las-Peñas
    Previous studies dealing with pressure pain sensitivity or muscle tenderness in migraine have shown conflicting results. Our aim was to explore the differences in mechanical pain sensitivity and pericranial muscle tenderness between patients with unilateral migraine and healthy controls, and to analyse side-to-side differences in both study groups. Pressure pain thresholds (PPT) at cephalic and neck points, plus local and total tenderness scores were blindly assessed in 25 patients with strictly unilateral migraine and 25 healthy subjects. For PPT in the neck there were significant differences between groups (F = 47.029; P < 0.001) and sides (F = 6.363; P < 0.01), and a significant interaction between group and side (F = 5.201; P = 0.02), while PPT in the cephalic point showed differences between groups (F = 11.774; P < 0.001), but not sides (F = 2.838; P = 0.1). The total tenderness score showed significant differences between groups (F = 6.800; P < 0.01) and sides (F = 17.699; P < 0.001), along with a significant interaction between group and side (F = 14.420; P < 0.001). Patients had lower PPT and increased pericranial tenderness on the symptomatic side as compared with the non-symptomatic side and to either side in controls (P < 0.001), whereas no significant differences were identified between the non-symptomatic side and controls (P > 0.9). In migraine patients, PPT levels and muscle tenderness scores were negatively correlated (P < 0.001). The enhancement of local tenderness scores was related to hyperesthesia of specific muscles (sternocleidomastoid, suboccipital, and temporalis) rather than a generalized pericranial tenderness. Future studies should investigate the neuro-physiological basis for the laterality of allodynic and hyperalgesic responses in unilateral migraine. [source]


    Juvenile-onset neuronal ceroid lipofuscinosis with infantile CLN1 mutation and palmitoyl-protein thioesterase deficiency

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2007
    R. Kälviäinen
    Accurate diagnosis, especially in progressive hereditary diseases, is essential for the treatment and genetic counseling of the patient and the family. Neuronal ceroid lipofuscinoses (NCL) are amongst the most common groups of neurodegenerative diseases. Infantile, juvenile, and adult-onset types with multiple genotype,phenotype associations have been described. A fluorimetric enzyme assay for palmitoyl protein thioesterase (PPT) from leukocytes and fibroblasts has been previously developed to confirm the diagnosis of infantile NCL. We describe a patient with juvenile-onset NCL phenotype with a new CLN1 mutation and deficient PPT activity. Over 40 different mutations have been found in patients with PPT deficiency, indicating that screening for known mutations is not an efficient way to diagnose this disorder. Therefore, PPT enzyme analysis should precede mutation analysis in suspected PPT deficiency, particularly in patients with granular osmiophilic deposits (GROD) or in patients who have negative ultrastructural data. The use of enzyme assay led to the diagnosis of this patient with juvenile-onset Finnish variant NCL with PPT deficiency, and we expect that greater awareness of the utility of the enzymatic assay may lead to identification of other similar cases awaiting a definitive diagnosis. [source]


    c-Src kinase activation regulates preprotachykinin gene expression and substance P secretion in rat sensory ganglia

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2003
    Orisa J. Igwe
    Abstract Increased synthesis of substance P (SP) in the dorsal root ganglia (DRG) and enhanced axonal transport to and secretion from the primary afferent sensory neurons might enhance pain signalling in the spinal dorsal horn by modifying pronociceptive pathways. IL-1, increases SP synthesis by enhancing the expression of preprotachykinin (PPT) mRNA encoding for SP and other tachykinins in the DRG. Stimulation of IL-1 receptor by IL-1, may induce the phosphorylation of tyrosine residues in many effector proteins through the activation of p60c-src kinase. The hypothesis that the synthesis of SP in and secretion from the primary sensory ganglia are regulated by the activation of p60c-src kinase induced by IL-1, was tested. Pretreatment of DRG neurons in culture with herbimycin A, genistein or PP2, three structurally different nonreceptor tyrosine kinase inhibitors that act by different mechanisms, decreased the kinase activity of p60c-src induced by the activation of IL-1 receptor. PP3, a negative control for the Src family of tyrosine kinase inhibitor PP2 had no effect. Herbimycin A and genistein also decreased IL-1,-induced expression of PPT mRNA-encoding transcripts and the levels of SP-li synthesized in the cells and secreted into the culture medium in a concentration-dependent manner. SB 203580 [a p38 mitogen-activated protein kinase (p38 MAPK) inhibitor] and PD 98059 (a p44/42 MAPK kinase inhibitor) were ineffective in modulating IL-1,-induced SP synthesis and secretion, and p60c-src kinase activity in DRG neurons. Whereas, IL-1 receptor antagonist and cycloheximide inhibited IL-1,-evoked secretion of SP-like immunoreactivity (SP-li), actinomycin D decreased it significantly but did not entirely abolish it. These findings show that phosphorylation of specific protein tyrosine residue(s) following IL-1 receptor activation might play a key role in IL-1, signalling to modulate PPT gene expression and SP secretion in sensory neurons. In view of the role of SP as an immunomodulator, these studies provide a new insight into neural-immune intercommunication in pain regulation in the sensory ganglia through the IL-1,-induced p60c-src activation. [source]


    Screening of plenum cables using a small-scale fire test protocol

    FIRE AND MATERIALS, Issue 1 2006
    Mohammed M. Khan
    Abstract The extent of flame propagation of electric cables in the FM Global intermediate-scale parallel panel test (PPT) using a 60 kW sand burner has been correlated with a dimensional fire propagation index (FPI,)[(m/s1/2)/(kW/m)2/3] derived from ignition and vertical propagation tests in small-scale ASTM E-2058 Fire Propagation Apparatus (FPA). Two distinct types of fire behavior were observed in the PPT. The cables that did not propagate beyond the vicinity of the ignition burner flames have a FPI equal to or less than 7 [(m/s1/2)/(kW/m)2/3], whereas cables that propagated to the top of the 4.9 m parallel panels had a FPI equal to or greater than 14 [(m/s1/2)/(kW/m)2/3]. All the plenum rated (Ul-910 or NFPA 262 tested) cables tested in this study did not exhibit flame propagation in the PPT, had FPI values of 7 [(m/s1/2)/(kW/m)2/3] or less and generated considerably lower smoke than those cables that propagated in the PPT. Based on this study, it is suggested that FPI measured in ASTM E-2058 FPA may be used for screening cables for UL-910 or NFPA262 tests, thus requiring substantially less cable to be supplied for testing. Copyright © 2005 John Wiley & Sons, Ltd. [source]


    Penile pharmacotesting in diagnosing male erectile dysfunction: evidence for lack of accuracy and specificity

    INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2002
    Antonio Aversa
    Penile pharmacotesting (PPT) with alprostadil (PGE1) represents the most common diagnostic approach to male erectile dysfunction (ED). A positive response , i.e. normal erectile rigidity of sustained duration , is presumed to exclude venous or arterial pathology with enough accuracy. To test this assumption we compared PPT vs. flowmetric results obtained by colour-duplex Doppler ultrasound (CDDU) in patients (pts) undergoing diagnostic evaluation for ED under conditions of maximal cavernous relaxation. A total of 195 non-consecutive impotent pts were diagnosed after dynamic CDDU as non-vasculogenic (NOR), or having arteriogenic (AR), veno-occlusive (VO) or mixed (MX) ED. Maximal erection obtained after PPT was scored as: type-1 (full tumescence , no sustained rigidity, angle on the abdominal plane >90°), type-2 (sustained partial erection, valid for intromission, angle=90°) and type-3 (sustained full erection, angle <90°). Comparing PPT with flowmetric results, we found that a type-3 response had 20% false negative diagnosis of NOR (17% of AR- and 3% of VO- and MX-ED, respectively), while a type-2 response had 63% false negative diagnosis (20% of AR, 37% of VO- and 6% MX-ED, respectively). Type-1 response was associated with the presence of VO dysfunction in 99% of cases. These data suggest that a positive response to PPT (type-2 and type-3) assessed by the visual rating of erection is associated with both arterial (up to 20%) and/or VO (up to 43%) ED, as detected by CDDU. We conclude that PPT alone is a misleading diagnostic test to exclude vascular ED and that dynamic CDDU should be offered to pts investigated for male ED. [source]


    Defining and maximizing PPT,a novel performance parameter for IEEE 802.11 DCF

    INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 9 2006
    Yun Li
    Abstract Much research has been conducted on saturation throughput of IEEE802.11 DCF, and has led to some improvement. But increasing the successful transmission probability of packet is also important for saving stations' battery energy and decreasing the packet delay. In this paper, we define a new performance parameter, named Product of successful transmission Probability and saturation Throughput (PPT), for 802.11 DCF, which binds successful transmission probability and saturation throughput together. An analysis is given to maximize PPT. An expression of optimal minimum contention windows (CWmin) is obtained analytically for maximizing PPT. For simplicity, we give a name DCF-PPT to the 802.11 DCF that sets its CWmin according to this expression. The performance of DCF-PPT is simulated with different stations in terms of saturation throughput, successful transmission probability and PPT. The simulation results indicate that, compared to 802.11 DCF, DCF-PPT can significantly increase the PPT and successful transmission probability (about 0.95) on condition that the saturation throughput is not decreased. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Oestrogen Receptors Enhance Dopamine Neurone Survival in Rat Midbrain

    JOURNAL OF NEUROENDOCRINOLOGY, Issue 4 2010
    M. L. Johnson
    Previous findings in our laboratory and elsewhere have shown that ovariectomy of rats in adulthood attenuates cocaine-stimulated locomotor behaviour. Ovarian hormones enhance both cocaine-stimulated behaviour and increase dopamine overflow after psychomotor stimulants. The present study aimed to determine whether ovarian hormones have these effects in part by maintaining dopamine neurone number in the substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA) and to investigate the roles of specific oestrogen receptors (ERs) in the maintenance of mesencephalic dopamine neurones. To accomplish this goal, we used unbiased stereological techniques to estimate the number of tyrosine hydroxylase-immunoreactive (TH-IR) cell bodies in midbrain regions of intact, ovariectomised and hormone-replaced female rats and mice. Animals received active or sham gonadectomy on postnatal day 60 and received vehicle, 17,-oestradiol (E2) or selective ER agonists propyl-pyrazole-triol (PPT, ER,) or diarylpropionitrile (DPN, ER,) for 1 month post-surgery. In both rats and mice, ovariectomy reduced the number of TH-IR cells in the SNpc and VTA. Replacement with E2, PPT or DPN prevented or attenuated the loss observed with ovariectomy in both rats and mice. An additional study using ER knockout mice revealed that adult female mice lacking ER, had fewer TH-IR cells in midbrain regions than wild-type mice, whereas mice lacking ER, had TH-IR cell counts comparable to wild-type. These findings suggest that, although both ER subtypes play a role in the maintenance of TH-IR cell number in the SNpc and VTA, ER, may play a more significant role. [source]


    The effects of manual therapy and exercise directed at the cervical spine on pain and pressure pain sensitivity in patients with myofascial temporomandibular disorders

    JOURNAL OF ORAL REHABILITATION, Issue 9 2009
    R. LA TOUCHE
    Summary, No studies have investigated the effects of the treatments directed at the cervical spine in patients with temporomandibular disorders (TMD). Our aim was to investigate the effects of joint mobilization and exercise directed at the cervical spine on pain intensity and pressure pain sensitivity in the muscles of mastication in patients with TMD. Nineteen patients (14 females), aged 19,57 years, with myofascial TMD were included. All patients received a total of 10 treatment session over a 5-week period (twice per week). Treatment included manual therapy techniques and exercise directed at the cervical spine. Outcome measures included bilateral pressure pain threshold (PPT) levels over the masseter and temporalis muscles, active pain-free mouth opening (mm) and pain (Visual Analogue Scale) and were all assessed pre-intervention, 48 h after the last treatment (post-intervention) and at 12-week follow-up period. Mixed-model anovas were used to examine the effects of the intervention on each outcome measure. Within-group effect sizes were calculated in order to assess clinical effect. The 2 × 3 mixed model anova revealed significant effect for time (F = 77·8; P < 0·001) but not for side (F = 0·2; P = 0·7) for changes in PPT over the masseter muscle and over the temporalis muscle (time: F = 66·8; P < 0·001; side: F = 0·07; P = 0·8). Post hoc revealed significant differences between pre-intervention and both post-intervention and follow-up periods (P < 0·001) but not between post-intervention and follow-up period (P = 0·9) for both muscles. Within-group effect sizes were large (d > 1·0) for both follow-up periods in both muscles. The anova found a significant effect for time (F = 78·6; P < 0·001) for changes in pain intensity and active pain-free mouth opening (F = 17·1; P < 0·001). Significant differences were found between pre-intervention and both post-intervention and follow-up periods (P < 0·001) but not between the post-intervention and follow-up period (P > 0·7). Within-group effect sizes were large (d > 0·8) for both post-intervention and follow-up periods. The application of treatment directed at the cervical spine may be beneficial in decreasing pain intensity, increasing PPTs over the masticatory muscles and an increasing pain-free mouth opening in patients with myofascial TMD. [source]


    The effect of tooth clenching on the sensory and pain perception in the oro-facial region of symptom-free men and women

    JOURNAL OF ORAL REHABILITATION, Issue 7 2009
    I. OKAYASU
    Summary, The aim of this study was (i) to examine the effect of light tooth contact as in diurnal tooth clenching on the tactile detection threshold (TDT), the filament-prick pain detection threshold (FPT) and the pressure pain threshold (PPT) in the oro-facial region and (ii) to examine the possible gender difference in this effect on the tactile and pain perception. Twenty healthy volunteers participated. The TDT and the FPT were measured by means of Semmes-Weinstein monofilaments, on the cheek skin (CS) overlying the masseter muscles (MM) and on the skin overlying the palm side of the thenar skin (TS). The PPT was measured at the central part of the MM using a pressure algometer. Each parameter was measured before and after keeping light tooth contact for 5 min (session 1) and after keeping the jaw relaxed for 5 min (session 2) as a control. Although there were no significant session effects on any of the parameters, there were significant effects of experimental condition on the TDT in both men and women (P < 0·001). Men had a significant higher FPT of the left CS (P < 0·05) and TS (P < 0·01) and a significant higher PPT of the MM than women (P < 0·001). These results illustrate that sensitivity to pain (FPT, PPT) was higher in women than in men. Although there were no significant gender differences in habituation of sensory perception, the increase of TDT after clenching/no clenching was larger in women, which warrants further study. [source]


    Pressure,pain threshold of oral mucosa and its region-specific modulation by pre-loading

    JOURNAL OF ORAL REHABILITATION, Issue 11 2003
    T. Ogawa
    summary Once subjected to denture wearing, oral mucosa has to withstand mechanical loads of various levels and durations. However, how this load affects oral mucosal sensitivity is unknown. This study investigated the pressure,pain threshold (PPT) of oral mucosa with or without pre-loading. An electric pressure algometer was developed specifically for measuring the PPT of oral mucosa. Measurements of 10 dentulous maxillae showed that the baseline PPT (BPPT) of the palatal site was 4·9- and 3·7-fold greater than that of the labial or buccal sites, respectively. The PPT of the labial site decreased significantly compared with its BPPT after 2 s,100% BPPT and 5 s,100% BPPT pre-loading. The PPT of the palatal site increased after 5 s,50% BPPT and 5 s,80% BPPT and 0·2 s,100% BPPT and 2 s,100% BPPT pre-loading. The PPT of the buccal site did not change after all levels and durations of pre-loadings tested. These results indicated the disproportionate modulation of oral mucosal PPT following various loads, suggesting that oral mucosa possesses region-specific psychophysical tolerance to mechanical stimuli. [source]


    Pressure,pain threshold determination in the oral mucosa: validity and reliability

    JOURNAL OF ORAL REHABILITATION, Issue 7 2002
    T. Ogimoto
    Fundamental knowledge of pain in the oral mucosa is lacking. We determined the validity and reliability of the pressure,pain threshold (PPT) measurement in the oral mucosa using a newly developed hand-held pressure algometer. Ten dentulous subjects were recruited, and the PPT was measured at the bilateral buccal (on the attached gingiva apical to the midline of the upper first premolars, 3 mm from the mucogingival junction) and the palatal sites (mid-point between the bilateral upper first molars). The PPT linearly increased with an increase in load-rate (P < 0·0001). The PPT yielded a high intra-individual stability both for the same-day consecutive trials and weekly sessions. The palatal site revealed a 4- to 4·65-fold greater PPT than the buccal sites (Bonferroni, P < 0·0001), whereas no difference was found between the bilateral buccal sites (P=0·663). Despite a great interindividual variation in the PPT, significant intra-individual correlations were found among the measurement sites. This suggested differences in individual sensitivity to pain in the oral mucosa, which may determine overall pain sensation specific to an individual. A pressure algometer described herein reliably assessed the PPT in the oral mucosa and sensitively discriminated PPT differences at different sites and at different load-rates, suggest-ing the reliability and validity of PPT measure-ments in the oral mucosa for clinical and research investigations. [source]


    Osteogenesis induced by extracorporeal shockwave in treatment of delayed osteotendinous junction healing

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2010
    Ling Qin
    Abstract Healing at the osteotendinous junction (OTJ) is challenging in orthopedic surgery. The present study aimed to test extracorporeal shockwave (ESW) in treatment of a delayed OTJ healing. Twenty-eight rabbits were used for establishing a delayed healing (DH) model at patella-patellar-tendon (PPT) complex after partial patellectomy for 4 weeks and then were divided into DH and ESW groups. In the ESW group, a single ESW treatment was given at postoperative week 6 to the PPT healing complex. The samples were harvested at week 8 and 12 for radiographic and histological evaluations with seven samples for each group at each time point. Micro-CT results showed that new bone volume was 1.18 ± 0.61,mm3 in the ESW group with no measurable new bone in the DH group at postoperative week 8. Scar tissue formed at the OTJ healing interface of the DH group, whereas ESW triggered high expression of VEGF in hypertrophic chondrocytes at week 8 and regeneration of the fibrocartilage zone at week 12 postoperatively. The accelerated osteogenesis could be explained by acceleration of endochondral ossification. In conclusion, ESW was able to induce osteogenesis at OTJ with delayed healing with enhanced endochondral ossification process and regeneration of fibrocartilage zone. These findings formed a scientific basis to potential clinical application of ESW for treatment of delayed OTJ healing. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:70,76, 2010 [source]


    Inflammatory Pain Reduction In Rats By Local Treatment With oATP, A Selective Inhibitor Of P2X7 ATP Receptor

    JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2001
    G Dell'Antonio
    Peptide neurotransmitters, as substance P or ATP, are released during inflammatiory processes by the nerve endings of sensory fibers. ATP is also released from the cytoplasm of damaged cells at the site of inflammation. It acts at the level of many P2X subtypes of purinoreceptors. The receptor for extracellular ATP named P2Z/P2X7 is selectively blocked by the periodate oxidized ATP (oATP). We have hypothesized that P2X subunits present on peripheral sensory nerve terminals, able to initiate a nociceptive signal, could be blocked by local treatment with oATP, so inducing pain relief. Male inbred Fisher rats weighing about 250 g were used. Unilateral inflammation into rat hind paw was induced by intraplantar injection of Freund's complete adjuvant (FCA). The following signs of inflammation, from 3 to 48 h after FCA injection, were detected: increased paw volume, increased paw temperature and hyperalgesia. The latter was evaluated using an algesiometric test wich measured the paw pressure threshold (PPT, expressed in g). We treated some rats, bearing paw inflammation by 12 h, with local injection of 56 ,M oATP. We showed a significant reduction of hyperalgesia in treated rats (PPT = 190 ± 2.3 in inflamed paw of oATP treated vs. PPT = 60 ± 1.6 in inflamed paw of untreated rats, at 60 min following oATP innoculation). We showed also that treatment with oATP was more efficient than treatment with diclofenac in reducing local inflammatory pain (PPT expressed as percentage of the maximum possible effect = 60 ± 0.5, at 120 min following intraplantar administration of oATP, vs. 25 ± 1.9 at the same time following intraplantar administration of diclofenac). The use of polyclonal antibody anti P2X7 receptor to perform immunohistochemical analysis of inflamed tissue, showed a reduction of receptor expression at the level of nerve endings in sections obtained from rat paw treated with oATP with respect to sections obtained from untreated rats. Such an effect was independent on the recruitment of immunocytes in inflamed tissue. Our results demonstrate that ATP exerts a key role in the pathophysiology of peripheral inflammation and that oATP may be effective in treating inflammatory pain. [source]


    Kinetic Analysis and Optimization for the Catalytic Esterification Step of PPT Polymerization

    MACROMOLECULAR THEORY AND SIMULATIONS, Issue 1 2005
    Saptarshi Majumdar
    Abstract Summary: A well-validated kinetic scheme has been studied for PPT, poly(propylene terephthalate) polymerization process in batch and semi-batch mode with tetrabutoxytitanium (TBOT), a proven catalyst. Optimization study and analysis for PPT are rare, as the industrial relevance of PPT just became vibrant due to the commercial availability of one of its monomers in industrial scale in the recent past. Correctness of the analysis is checked by a new approach and parameters for the model are estimated from available experimental data. Solubility of terephthalic acid (TPA) is less in reaction medium and this effect is also considered along with the reaction scheme. Several simulations have been performed to see various process dynamics and this ultimately helps in formulating optimization problems. Using recently developed and well tested real-coded non-dominated sorting genetic algorithm-II, a state-of-the art evolutionary optimization algorithm, a couple of three objective optimization problems have been solved and corresponding Pareto sets are presented. Results show remarkably promising aspects of productivity enhancement with an improvement in product quality. Sensitivity analysis for relatively uncertain solubility parameter is also performed to estimate its effect over the proposed optimal solutions. Multiobjective Pareto front for 3 objectives: degree of polymerization, time and (bTPA,+,bPG). [source]


    The Pain Provocation Technique for Adolescents with Chronic Pain: Preliminary Evidence for Its Effectiveness

    PAIN MEDICINE, Issue 6 2010
    Tanja Hechler PhD
    Abstract Objective., This study aims to investigate the effectiveness of the "pain provocation technique" (PPT),a focused treatment strategy incorporating interoceptive exposure (i.e., imagining increases in pain intensity), bilateral stimulation (tactile stimulation), and implementation of pain-related coping to decrease pain intensity,for adolescents suffering from chronic pain. Design., Prospective observational comparative study. Methods., Adolescents utilizing PPT (19 boys and 21 girls) within multimodal inpatient treatment were compared with adolescents in standard multimodal inpatient treatment matched for age, gender, and diagnosis. Core outcome variables (pain intensity, disability, emotional distress) were assessed at admission and 3 months posttreatment. Results., Adolescents in the PPT group demonstrated a sharper decrease in pain intensity and school aversion. Both groups demonstrated significant reductions in disability and emotional distress. Conclusions., Results are discussed in terms of the importance of focused treatment strategies such as interoceptive exposure for adolescents suffering from disabling chronic pain. Future studies are warranted to carefully investigate the effectiveness and possible process of change during the PPT such as sensory, cognitive, emotional, and memory aspects. [source]


    Functional genomics of phosphate antiport systems of plastids

    PHYSIOLOGIA PLANTARUM, Issue 4 2003
    Ulf-Ingo Flügge
    Plant cells require a co-ordination of metabolism between their major compartments, the plastids and the cytosol, in particular as certain metabolic pathways are confined to either compartments. The inner envelope membrane of the plastids forms the major barrier for metabolite exchange and is the site for numerous transport proteins, which selectively catalyse metabolite exchanges characteristic for green and/or non-green tissues. This report is focused on the molecular biology, evolution and physiological function of the family of phosphate translocators (PT) from plastids. Until now, four distinct subfamilies have been identified and characterized, which all share inorganic phosphate as common substrate, but have different spectra of counter exchange substrates to fulfil the metabolic needs of individual cells and tissues. The PTs are named after their main transported substrate, triose phosphate (TPT), phosphoenolpyruvate (PPT), glucose 6-phosphate (GPT) and xylulose 5-P (XPT). All PTs belong to the TPT/nucleotide sugar transporter (NST) superfamily, which includes yet uncharacterized PT homologues from plants and other eukaryotes. Transgenic plants or mutants with altered transport activity of some of the PTs have been generated or isolated. The analysis of these plant lines revealed new insights in the co-ordination and flexibility of plant metabolism. [source]


    Pollen presentation and pollination syndromes, with special reference to Penstemon

    PLANT SPECIES BIOLOGY, Issue 1 2000
    James D. Thomson
    Abstract Pollen presentation theory (PPT) allows for a re-examination of some classic themes in pollination biology. Here, we outline its implications in the context of bee- and bird-adapted species of Penstemon and Keckiella (Scrophulariaceae). PPT models the optimal schedule of pollen presentation, based on the frequency of visits by pollinators, and the capacities of those pollinators to remove and deposit pollen. High visitation rates, high removal and low deposition all favor plants that present pollen in many small doses. Dosing is achieved through gradual opening of anthers and through anthers opening only narrowly. We hypothesize that bees have higher rates of removal and lower rates of deposition than birds; therefore, bee-pollinated species should have anthers that open more gradually and less completely than bird-pollinated species. Before presenting preliminary results that affirm this prediction, we critically discuss the characterization of species by pollination syndrome. PPT sheds new light on why plants may specialize on particular pollinators. Stebbins' most effective pollinator can be recast as the pollinator that deposits more of the pollen that it removes, thereby making other visitors into conditional parasites. Pollinator shifts might occur when a pollinator with low removal and high deposition becomes abundant; the plants would then be selected to discourage their previous pollinators who are now parasites. Bird-pollination may favor anthers that open quickly and widely, thereby making bees wasteful parasites. Bee-pollination may favor anthers that open slowly and narrowly, thereby making birds ineffective pollinators. In paired comparisons of closely related species, the hummingbird-visited species were redder, had narrower or longer floral tubes, more exserted anthers and stigmas, less pronounced landing platforms, more inclined orientation, produced more nectar of a lower concentration, and had anthers that dehisce faster and more extensively. [source]


    A simplified protein precipitation/mixed-mode cation-exchange solid-phase extraction, followed by high-speed liquid chromatography/mass spectrometry, for the determination of a basic drug in human plasma

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 18 2006
    Y.-J. Xue
    A simplified protein precipitation/mixed-mode cation-exchange solid-phase extraction (PPT/SPE) procedure has been investigated. A mixture of acetonitrile and methanol along with formic acid was used to precipitate plasma proteins prior to selectively extracting the basic drug. After vortexing and centrifugation, the supernatants were directly loaded onto an unconditioned Oasis® MCX µElution 96-well extraction plate, where the protonated drug was retained on the negatively charged sorbent while interfering neutral lipids, steroids or other endogenous materials were washed away. Normal wash steps were deemed unnecessary and not used before sample elution. The sample extracts were analyzed under both conventional and high-speed liquid chromatography/tandem mass spectrometry (LC/MS/MS) conditions to examine the feasibility of the PPT/SPE procedure for human plasma sample clean-up. For the conventional LC/MS/MS method, chromatographic separation was achieved on a C18, 2.1,×,50,mm column with gradient elution (k,,=,5.5). The mobile phase contained 0.1% formic acid in water and 0.1% formic acid in acetonitrile. For the high-speed LC/MS/MS method, chromatographic separation was achieved on a C18, 2.1,×,10,mm guard column with gradient elution (k,,=,2.2, Rt,=,0.26,min). The mobile phase contained 0.1% formic acid in water and 0.001% trifluoroacetic acid in acetonitrile. Detection for both conventional and high-speed LC/MS/MS methods was by positive ion electrospray tandem mass spectrometry on a ThermoElectron Finnigan TSQ Quantum Ultra, where enhanced resolution (RP 2000; 0.2,amu) was used for high-speed LC/MS/MS. The standard curve, ranging from 0.5 to 100,ng/mL, was fitted to a 1/x weighted quadratic regression model. This combined PPT/SPE procedure effectively eliminated time-consuming sorbent conditioning and wash steps, which are essential for a conventional mixed-mode SPE procedure, but retained the advantages of both PPT (removal of plasma proteins) and mixed-mode SPE (analyte selectivity). The validation results demonstrated that this PPT/SPE procedure was well suited for both conventional and high-speed LC/MS/MS analyses. In comparison with a conventional mixed-mode SPE procedure, the simplified PPT/SPE process provided comparable sample extract purity. This simple sample clean-up procedure can be applied to other basic compounds with minor modifications of PPT solvents. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Control of Cell Number in the Bed Nucleus of the Stria Terminalis of Mice: Role of Testosterone Metabolites and Estrogen Receptor Subtypes

    THE JOURNAL OF SEXUAL MEDICINE, Issue 4pt1 2010
    Shin-ichi Hisasue MD
    ABSTRACT Introduction., The bed nucleus of the stria terminalis (BNST) exhibits several sex differences that may be related to male sexual behavior and gender identity. In mice and rats, sex differences in the principal nucleus of the BNST (BNSTp) are due to sexually dimorphic cell death during perinatal life. Although testosterone treatment of newborn female rats increases BNSTp cell number, the relevant hormone metabolite(s) are not known, and the effect of testosterone on the development of BNSTp cell number in mice has not been examined. Aim., To identify the sex hormone metabolites and receptors controlling cell number, volume, and cell size in the BNSTp of mice. Methods., In the first experiment, C57BL/6J male mice were injected on the day of birth with peanut oil; females were injected with testosterone propionate (TP), estradiol benzoate (EB), dihydrotestosterone propionate (DHTP), or oil alone, and the BNSTp of all animals was examined in adulthood. In the second experiment, to compare effects of EB to the effects of estrogen receptor subtype specific agonists, newborn female mice were injected with EB, propyl-pyrazole-triol (PPT, a selective estrogen receptor alpha [ER,] agonist), or diarylpropionitrile (DPN, a selective estrogen receptor beta [ER,] agonist). Main Outcome Measures., Nuclear volume measurements and stereological cell counts in the BNSTp in adulthood. Results., TP treatment of newborn females completely masculinized both BNSTp volume and cell number. EB masculinized neuron number, whereas DHTP had no effect on volume or cell number. In the second experiment, EB again fully masculinized neuron number in the BNSTp and in this study also masculinized BNSTp volume. PPT and DPN each significantly increased cell number, but neither completely mimicked the effects of EB. Conclusions., We conclude that estrogenic metabolites of testosterone control sexually dimorphic cell survival in the BNSTp and that activation of both ER, and ER, may be required for complete masculinization of this brain region. Hisasue S, Seney ML, Immerman E, and Forger NG. Control of cell number in the bed nucleus of the stria terminalis of mice: Role of testosterone metabolites and estrogen receptor subtypes. J Sex Med 2010;7:1401,1409. [source]


    Plastidic metabolite transporters and their physiological functions in the inducible crassulacean acid metabolism plant Mesembryanthemum crystallinum

    THE PLANT JOURNAL, Issue 3 2000
    Rainer E. Häusler
    Summary The inducible crassulacean acid metabolism (CAM) plant Mesembryanthemum crystallinum accumulates malic acid during the night and converts it to starch during the day via a pathway that, because it is located in different subcellular compartments, depends on specific metabolite transport across membranes. The chloroplast glucose transporter (pGlcT) and three members of the phosphate translocator (PT) family were isolated. After induction of CAM, transcript amounts of the phosphoenolpyruvate (PEP) phosphate translocator (PPT) and the glucose-6-phosphate (Glc6P) phosphate translocator (GPT) genes were increased drastically, while triose phosphate (TP) phosphate translocator (TPT) and the pGlcT transcripts remained unchanged. PPT- and GPT-specific transcripts and transporter activities exhibited a pronounced diurnal variation, displaying the highest amplitude in the light. pGlcT transcripts were elevated towards the end of the light period and at the beginning of the dark period. These findings, combined with diurnal variations of enzyme activities and metabolite contents, helped to elucidate the roles of the PPT, GPT, TPT and pGlcT in CAM. The main function of the PPT is the daytime export from the stroma of PEP generated by pyruvate orthophosphate:dikinase (PPDK). The increased transport activity of GPT in the light suggests a higher requirement for Glc6P import for starch synthesis rather than starch mobilization. Most likely, Glc6P rather than 3-phosphoglycerate or triose phosphates is the main substrate for daytime starch biosynthesis in M. crystallinum plants in which CAM has been induced (CAM-induced), similar to non-green plastids. In the dark, starch is mobilized both phosphorylytically and amylolytically and the products are exported by the GPT, TPT and pGlcT. The transport activities of all three phosphate translocators and the transcript amounts of the pGlcT adapt to changing transport requirements in order to maintain high metabolic fluxes during the diurnal CAM cycle. [source]


    Adult neuronal ceroid lipofuscinosis with palmitoyl-protein thioesterase deficiency: First adult-onset patients of a childhood disease

    ANNALS OF NEUROLOGY, Issue 2 2001
    Otto P. Van Diggelen PhD
    The fluorogenic enzyme assay for palmitoyl-protein thioesterase (PPT) has greatly facilitated the diagnosis of infantile neuronal ceroid lipofuscinosis (Santavuori-Haltia disease) and the search for possible new variants with atypical clinical presentation. Here, we present the first cases of adult neuronal ceroid lipofuscinosis with onset in the fourth decade of life due to a profound deficiency of PPT. The causative mutations in the CLN1 gene were the known, deleterious mutation R151X and the novel missense mutation G108R. Patients presented at onset (31 and 38 years), with psychiatric symptoms only. At present (ages 56 and 54 years), visual, verbal, and cognitive losses have progressed and both patients have cerebellar ataxia and cannot walk without support. [source]


    Amelioration of collagen-induced arthritis and immune-associated bone loss through signaling via estrogen receptor ,, and not estrogen receptor , or G protein,coupled receptor 30

    ARTHRITIS & RHEUMATISM, Issue 2 2010
    Cecilia Engdahl
    Objective The effects of estrogen may be exerted via the nuclear estrogen receptors (ERs) ER, or ER, or via the recently proposed transmembrane estrogen receptor G protein,coupled receptor 30 (GPR-30). The purpose of this study was to elucidate the ER specificity for the ameliorating effects of estrogen on arthritis and bone loss in a model of postmenopausal rheumatoid arthritis (RA). Methods Female DBA/1 mice underwent ovariectomy or sham operation, and type II collagen,induced arthritis was induced. Mice were treated subcutaneously 5 days/week with the specific agonists propylpyrazoletriol (PPT; for ER,), diarylpropionitrile (DPN; for ER,), G1 (for GPR-30), or with a physiologic dose of estradiol. Clinical arthritis scores were determined continuously. At termination of the study, bone mineral density (BMD) was analyzed, paws were collected for histologic assessment, serum was analyzed for cytokines and markers of bone and cartilage turnover, and bone marrow was subjected to fluorescence-activated cell sorting. Results Treatment with PPT as well as estradiol dramatically decreased the frequency and severity of arthritis. Furthermore, estradiol and PPT treatment resulted in preservation of bone and cartilage, as demonstrated by increased BMD and decreased serum levels of bone resorption markers and cartilage degradation markers, whereas no effect was seen after DPN or G1 treatment. Conclusion In a well-established model of postmenopausal RA, ER,, but not ER, or GPR-30 signaling, was shown to ameliorate the disease and the associated development of osteoporosis. Since long-term treatment with estrogen has been associated with significant side effects, increased knowledge about the mechanisms behind the beneficial effects of estrogen is useful in the search for novel treatments of postmenopausal RA. [source]


    Tachykinin expression in cartilage and function in human articular chondrocyte mechanotransduction

    ARTHRITIS & RHEUMATISM, Issue 1 2003
    S. J. Millward-Sadler
    Objective To assess whether substance P and the corresponding neurokinin 1 (NK1) receptor are expressed in human articular cartilage, and whether these molecules have a role in chondrocyte mechanotransduction. Methods Transgenic studies, immunohistochemistry, Western blotting, and reverse transcriptase,polymerase chain reaction were used to assess the expression of the preprotachykinin (PPT) gene, substance P, and NK1 in developing mice, in adult human articular cartilage, and in human chondrocytes in culture. Chondrocytes obtained from PPT knockout mice and human articular chondrocytes were mechanically stimulated in the presence or absence of inhibitors of substance P signaling, and cell membrane potentials or relative levels of aggrecan messenger RNA (mRNA) were measured. Results Replacing a region of the PPT gene transcriptional site that contains a dominant repressor of the proximal promoter activity with the constitutive minimal promoter of the human ,-globin promoter allowed expression of a marker gene in areas of chondrogenesis during mouse development and in adult chondrocytes grown in culture. Adult human articular chondrocytes expressed endogenous PPT mRNA, substance P, and the corresponding NK1 receptor in vivo and in vitro. Blockade of substance P signaling by a chemical antagonist to the NK1 receptor inhibited chondrocyte responses to mechanical stimulation. Conclusion Substance P is expressed in human articular cartilage and is involved in chondrocyte mechanotransduction via the NK1 receptor in an autocrine and paracrine manner. This suggests that substance P and the NK1 receptor have roles in the maintenance of articular cartilage structure and function that were previously unrecognized. [source]


    Antioxidant and Hepatoprotective Effects of Cyathea phalerata Mart. (Cyatheaceae)

    BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2008
    Mariana Appel Hort
    The in vitro antioxidant potential of the crude extract (CE), precipitate (PPT), aqueous fraction (AQF), n-butanolic fraction (BUF) and ethyl acetate fraction (EAF) from C. phalerata was evaluated through the scavenging of diphenyl-1-picryl-hydrazyl-hydrate (DPPH), superoxide anion (O2,,) (nitroblue tetrazolium assay) and hydroxyl radicals (OH,) (deoxyribose assay), and lipid peroxidation in rat liver homogenate. In these assays, it was observed that EAF had marked antioxidant potential, especially as a scavenger of the OH, radical and in inhibiting lipid peroxidation. The in vivo evaluation of oxidative stress (DNA fragmentation, membrane lipoperoxidation and carbonyl protein formation) and the antioxidant defenses (concentration of reduced glutathione, as well as catalase and glutathione S-transferase activities) were measured in mice pre-treated with EAF (10, 30 or 100 mg/kg, orally) and later exposed to carbon tetrachloride (CCl4). The EAF decreased thiobarbituric acid reactive substances levels, DNA damage and carbonyl protein contents, and increased catalase and glutathione S-transferase activities. Based on these results, it is concluded that the EAF from C. phalerata protects liver from oxidative stress induced by CCl4 in mice and these effects are probably related to the antioxidant activity associated with the free radical scavenging property of this fraction. [source]


    Endothelin-1 increases cholinergic nerve-mediated contraction of human bronchi via tachykinin synthesis induction

    BRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2001
    Bruno D'Agostino
    In some asthmatics, muscarinic receptor antagonists are effective in limiting bronchoconstrictor response, suggesting an abnormal cholinergic drive in these subjects. There is a growing body of evidences indicating that cholinergic neurotransmission is also enhanced by endothelin-1 (ET-1) in rabbit bronchi, mouse trachea and in human isolated airway preparations. We investigated the role of secondary mediators in ET-1 induced potentiation of cholinergic nerve-mediated contraction in human bronchi, in particular the possible role of neuropeptides in this phenomenon. Bronchial tissues after endothelin treatment were exposed to a standard electrical field stimulation (EFS) (30% of EFS 30Hz)-induced contraction. In addition, in some experiments, preparations were treated with a tachykinin NK2 receptor antagonist and subsequently exposed to the same protocol. HPLC and RIA were performed on organ bath fluid samples. Moreover, the human bronchi were used for the ,-PPT (preprotachykinin) mRNA extraction and semiquantitative reverse transcription polymerase chain reaction (RT , PCR), prior to and 30 , 40 min following ET-1 challenge. The selective tachykinin NK2 receptor antagonist, SR48968, was effective to reduce ET-1 potentiation of EFS mediated contraction. HPLC or RIA showed significant increased quantities of NKA in organ bath effluents after EFS stimulation in bronchi pretreated with ET-1. Finally, ,-PPT mRNA level after stimulation of bronchi with ET-1 was increased about 2 fold respect to control untreated bronchi. In conclusion, this study demonstrated that, at least in part, the ET-1 potentiation of cholinergic nerve-mediated contraction is mediated by tachykinin release, suggesting that in addition to nerves, several type of cells, such as airway smooth muscle cell, may participate to neuropeptide production. British Journal of Pharmacology (2001) 134, 1447,1454; doi:10.1038/sj.bjp.0704395 [source]


    Quantitative Comparison of Ginsenosides and Polyacetylenes in Wild and Cultivated American Ginseng

    CHEMISTRY & BIODIVERSITY, Issue 4 2010
    Jing-Rong Wang
    Abstract Quantitative comparison of seven ginsenosides in wild and cultivated American ginseng revealed that the Rg1/Rd ratio presented a significantly large difference between cultivated and type-I (one of the defined chemotypes) wild American ginseng, facilitating this ratio as a characteristic marker for differentiating these two groups. Similarly, the ratio (Rg1+Re)/Rd, and the ratio of protopanaxatriol (PPT)-type ginsenosides to protopanaxadiol (PPD)-type ginsenosides showed a large difference between these two groups. On the other hand, type-II wild samples were found to have high Rg1/Rb1 and Rg1/Re ratios and low panaxydol/panaxynol ratio, which is entirely different from Type-I American ginseng, but is very similar to that of Asian ginseng. This not only suggests that the chemotype should be taken into consideration properly when using these parameters for differentiating American and Asian ginseng, but also indicates that type-II wild American ginseng may have distinct pharmacological activities and therapeutic effects. [source]


    Evaluation of some factors affecting the agreement between the Proview Eye Pressure Monitor and the Goldmann applanation tonometer measurements

    CLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 4 2007
    Pinakin Gunvant BS Optom PhD FAAO
    Background:, Our aim was to examine whether training level and ocular factors could account for part of the difference in intraocular pressure (IOP) measured using the Goldmann applanation tonometer (GAT) and Proview Eye Pressure Monitor (PPT). Methods:, One hundred and nineteen individuals (238 eyes) were enrolled in the study. The mean age was 35.8 years (range 21 to 79). All study participants obtained IOP measurements using the PPT after hearing instructions on how to perform PPT. Glaucoma patients obtained additional IOP measurements using PPT after viewing an instructional video and after 30 days of home use. IOP was also measured using the GAT at each experimental session. Results:, The difference in IOP measured by the GAT and the PPT was 0.55 ± 3.38 mmHg, 0.17 ± 3.79 mmHg and -1.30 ± 3.79 mmHg for myopic, emmetropic and hypermetropic groups, respectively, which were statistically significant (ANCOVA; p = 0.014). The difference in IOP between GAT and PPT was not significantly different for measurements obtained after verbal instructions, instructional video or after 30 days of home use (Repeated-ANCOVA; p = 0.30). The overall agreement between the GAT and the PPT was poor. Intra-class correlation coefficient was 0.575, and the 95% confidence interval (CI) of agreement was -6.93 to +6.73 mmHg. Conclusion:, There was a small systematic difference in IOP measured by the GAT and PPT when comparing the different refraction groups; however, this level of difference between the groups is unlikely to be of clinical significance. The level of training in using the PPT did not influence its measurements. The limits of agreement between the PPT and the GAT were wide and long-term use of PPT did not improve its agreement. [source]


    Responses of dryland soil respiration and soil carbon pool size to abrupt vs. gradual and individual vs. combined changes in soil temperature, precipitation, and atmospheric [CO2]: a simulation analysis

    GLOBAL CHANGE BIOLOGY, Issue 9 2009
    WEIJUN SHEN
    Abstract With the large extent and great amount of soil carbon (C) storage, drylands play an important role in terrestrial C balance and feedbacks to climate change. Yet, how dryland soils respond to gradual and concomitant changes in multiple global change drivers [e.g., temperature (Ts), precipitation (Ppt), and atmospheric [CO2] (CO2)] has rarely been studied. We used a process-based ecosystem model patch arid land simulator to simulate dryland soil respiration (Rs) and C pool size (Cs) changes to abrupt vs. gradual and single vs. combined alterations in Ts, Ppt and CO2 at multiple treatment levels. Results showed that abrupt perturbations generally resulted in larger Rs and had longer differentiated impacts than did gradual perturbations. Rs was stimulated by increases in Ts, Ppt, and CO2 in a nonlinear fashion (e.g., parabolically or asymptotically) but suppressed by Ppt reduction. Warming mainly stimulated heterotrophic Rs (i.e., Rh) whereas Ppt and CO2 influenced autotrophic Rs (i.e., Ra). The combined effects of warming, Ppt, and CO2 were nonadditive of primary single-factor effects as a result of substantial interactions among these factors. Warming amplified the effects of both Ppt addition and CO2 elevation whereas Ppt addition and CO2 elevation counteracted with each other. Precipitation reduction either magnified or suppressed warming and CO2 effects, depending on the magnitude of factor's alteration and the components of Rs (Ra or Rh) being examined. Overall, Ppt had dominant influence on dryland Rs and Cs over Ts and CO2. Increasing Ppt individually or in combination with Ts and CO2 benefited soil C sequestration. We therefore suggested that global change experimental studies for dryland ecosystems should focus more on the effects of precipitation regime changes and the combined effects of Ppt with other global change factors (e.g., Ts, CO2, and N deposition). [source]