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Publication
Journal: Journal of Cell Science
July/8/2009
Abstract
Fertility and embryonic viability are measures of efficient germ cell growth and development. During oogenesis and spermatogenesis, new proteins are required for both mitotic expansion and differentiation. Qualitative and quantitative changes in protein synthesis occur by translational control of mRNAs, mediated in part by eIF4E, which binds the mRNAs 5' cap. IFE-1 is one of five eIF4E isoforms identified in C. elegans. IFE-1 is expressed primarily in the germ line and associates with P granules, large mRNPs that store mRNAs. We isolated a strain that lacks IFE-1 [ife-1(bn127)] and demonstrated that the translation of several maternal mRNAs (pos-1, pal-1, mex-1 and oma-1) was inefficient relative to that in wild-type worms. At 25 degrees C, ife-1(bn127) spermatocytes failed in cytokinesis, prematurely expressed the pro-apoptotic protein CED-4/Apaf-1, and accumulated as multinucleate cells unable to mature to spermatids. A modest defect in oocyte development was also observed. Oocytes progressed normally through mitosis and meiosis, but subsequent production of competent oocytes became limiting, even in the presence of wild-type sperm. Combined gametogenesis defects decreased worm fertility by 80% at 20 degrees C; ife-1 worms were completely sterile at 25 degrees C. Thus, IFE-1 plays independent roles in late oogenesis and spermatogenesis through selective translation of germline-specific mRNAs.
Publication
Journal: European Journal of Clinical Nutrition
October/30/1997
Abstract
OBJECTIVE
To validate the use of an activity diary and predicted BMR for assessment of daily total energy expenditure (TEE) and physical activity level (PAL = TEE/BMR) in adolescents.
METHODS
TEE and PAL estimated from activity diary records kept for seven days and BMR predicted from age, gender and body weight were compared with the results of doubly labelled water (DLW) measurements and indirect calorimetry performed during the same time period.
METHODS
The Unit of paediatric Physiology of the Department of Clinical Physiology, University Hospital, Uppsala, Sweden.
METHODS
Fifty randomly selected 15 y old adolescents (25 boys and 25 girls).
RESULTS
The mean difference between TEE estimated in all adolescents by the activity diary and by DLW methods was 1.2%. The limits of agreement (mean difference 2 s.d.) were -3.47 and 3.77 MD/d, equivalent to a coefficient of variation of 15%. The mean difference between PAL assessed by activity diary records and by DLW measurements was 0.001, and the limits of agreement between the two methods were 0.54.
CONCLUSIONS
The results imply that the activity diary method provides a close estimate of TEE and PAL in population groups.
Publication
Journal: Medicine and Science in Sports and Exercise
January/5/2004
Abstract
OBJECTIVE
To compare two methods for measuring time spent in physical activity of differing absolute intensities.
METHODS
Over a 7-d period, 59 women wore Computer Science and Applications, Inc. (CSA) accelerometers and recorded their activity in physical activity logs (PAL) at 15-min intervals. Three published cut points were used to classify CSA data into resting/light, moderate, and vigorous intensity categories. Data were analyzed using descriptive statistics, Spearman rank-order correlations, and Bland-Altman plots.
RESULTS
The CSA estimates of total (moderate plus vigorous) physical activity using the three cut points ranged from a mean (+/- SD) of 38.1 (+/-26.8) min.d-1 to 312.6 (+/- 101.1) min.d-1. Using the PAL, women self-reported a mean (+/- SD) of 75.1 (+/- 51.7) min.d-1 of total activity. There was fair to modest rank-order agreement between each of the three CSA measures and the PAL measure of total activity, with correlations ranging from r = 0.15 to 0.24. Correlations between CSA and PAL estimates of total activity were higher in women with body mass index values (BMI) below 25 kg.m-2 (r = 0.23-0.38) compared with women with BMI>> or = 25 kg.m-2 (r = 0.06-0.08) but did not differ according to age. Correlations between the three CSA cut points ranged from r = 0.45 to 0.86.
CONCLUSIONS
Three published cut points designed to classify CSA output by intensity level produced different estimates of physical activity participation. Correlations between CSA and PAL measures of activity intensity were fair overall but higher among leaner women.
Publication
Journal: Bio/technology (Nature Publishing Company)
February/9/1992
Abstract
To target recombinant antibodies to the surface of Escherichia coli, we have fused single-chain variable domains to its peptidoglycan associated lipoprotein (PAL). The fusion protein was able to bind antigen and was tightly bound to the murein layer of the cell envelope. Antibody-PAL had little effect on cell growth and viability. In contrast, the expression of single chain antibody alone eventually resulted in cell lysis. Immunofluorescence studies on unfixed cells showed that functional antibodies were accessible at the surface of intact bacteria. This could provide a means of isolating single cells producing specific antibodies from libraries in E. coli by fluorescence assisted cell sorting (FACS). Pal fusions may also be of general interest for the presentation of proteins at the surface of E. coli as, for example, in the production of live vaccines.
Publication
Journal: Development (Cambridge)
March/3/2002
Abstract
The KH domain protein MEX-3 is central to the temporal and spatial control of PAL-1 expression in the C. elegans early embryo. PAL-1 is a Caudal-like homeodomain protein that is required to specify the fate of posterior blastomeres. While pal-1 mRNA is present throughout the oocyte and early embryo, PAL-1 protein is expressed only in posterior blastomeres, starting at the four-cell stage. To better understand how PAL-1 expression is regulated temporally and spatially, we have identified MEX-3 interacting proteins (MIPs) and characterized in detail two that are required for the patterning of PAL-1 expression. RNA interference of MEX-6, a CCCH zinc-finger protein, or SPN-4, an RNA recognition motif protein, causes PAL-1 to be expressed in all four blastomeres starting at the four-cell stage. Genetic analysis of the interactions between these mip genes and the par genes, which provide polarity information in the early embryo, defines convergent genetic pathways that regulate MEX-3 stability and activity to control the spatial pattern of PAL-1 expression. These experiments suggest that par-1 and par-4 affect distinct processes. par-1 is required for many aspects of embryonic polarity, including the restriction of MEX-3 and MEX-6 activity to the anterior blastomeres. We find that PAL-1 is not expressed in par-1 mutants, because MEX-3 and MEX-6 remain active in the posterior blastomeres. The role of par-4 is less well understood. Our analysis suggests that par-4 is required to inactivate MEX-3 at the four-cell stage. Thus, PAL-1 is not expressed in par-4 mutants because MEX-3 remains active in all blastomeres. We propose that MEX-6 and SPN-4 act with MEX-3 to translate the temporal and spatial information provided by the early acting par genes into the asymmetric expression of the cell fate determinant PAL-1.
Publication
Journal: Development (Cambridge)
November/27/2007
Abstract
Temporal control of programmed cell death is necessary to ensure that cells die at only the right time during animal development. How such temporal regulation is achieved remains poorly understood. In some Caenorhabditis elegans somatic cells, transcription of the egl-1/BH3-only gene promotes cell-specific death. The EGL-1 protein inhibits the CED-9/Bcl-2 protein, resulting in the release of the caspase activator CED-4/Apaf-1. Subsequent activation of the CED-3 caspase by CED-4 leads to cell death. Despite the important role of egl-1 transcription in promoting CED-3 activity in cells destined to die, it remains unclear whether the temporal control of cell death is mediated by egl-1 expression. Here, we show that egl-1 and ced-9 play only minor roles in the death of the C. elegans tail-spike cell, demonstrating that temporal control of tail-spike cell death can be achieved in the absence of egl-1. We go on to show that the timing of the onset of tail-spike cell death is controlled by transcriptional induction of the ced-3 caspase. We characterized the developmental expression pattern of ced-3, and show that, in the tail-spike cell, ced-3 expression is induced shortly before the cell dies, and this induction is sufficient to promote the demise of the cell. Both ced-3 expression and cell death are dependent on the transcription factor PAL-1, the C. elegans homolog of the mammalian tumor suppressor gene Cdx2. PAL-1 can bind to the ced-3 promoter sites that are crucial for tail-spike cell death, suggesting that it promotes cell death by directly activating ced-3 transcription. Our results highlight a role that has not been described previously for the transcriptional regulation of caspases in controlling the timing of cell death onset during animal development.
Publication
Journal: Applied and Environmental Microbiology
February/19/2009
Abstract
Two solvent-tolerant Pseudomonas putida S12 strains, originally designed for phenol and p-coumarate production, were engineered for efficient production of p-hydroxystyrene from glucose. This was established by introduction of the genes pal and pdc encoding L-phenylalanine/L-tyrosine ammonia lyase and p-coumaric acid decarboxylase, respectively. These enzymes allow the conversion of the central metabolite L-tyrosine into p-hydroxystyrene, via p-coumarate. Degradation of the p-coumarate intermediate was prevented by inactivating the fcs gene encoding feruloyl-coenzyme A synthetase. The best-performing strain was selected and cultivated in the fed-batch mode, resulting in the formation of 4.5 mM p-hydroxystyrene at a yield of 6.7% (C-mol of p-hydroxystyrene per C-mol of glucose) and a maximum volumetric productivity of 0.4 mM h(-1). At this concentration, growth and production were completely halted due to the toxicity of p-hydroxystyrene. Product toxicity was overcome by the application of a second phase of 1-decanol to extract p-hydroxystyrene during fed-batch cultivation. This resulted in a twofold increase of the maximum volumetric productivity (0.75 mM h(-1)) and a final total p-hydroxystyrene concentration of 21 mM, which is a fourfold improvement compared to the single-phase fed-batch cultivation. The final concentration of p-hydroxystyrene in the water phase was 1.2 mM, while a concentration of 147 mM (17.6 g liter(-1)) was obtained in the 1-decanol phase. Thus, a P. putida S12 strain producing the low-value compound phenol was successfully altered for the production of the toxic value-added compound p-hydroxystyrene.
Publication
Journal: Journal of Bacteriology
September/15/2003
Abstract
Proteins of the Tol-Pal (Tol-OprL) system play a key role in the maintenance of outer membrane integrity and cell morphology in gram-negative bacteria. Here we describe an additional role for this system in the transport of various carbon sources across the cytoplasmic membrane. Growth of Pseudomonas putida tol-oprL mutant strains in minimal medium with glycerol, fructose, or arginine was impaired, and the growth rate with succinate, proline, or sucrose as the carbon source was lower than the growth rate of the parental strain. Assays with radiolabeled substrates revealed that the rates of uptake of these compounds by mutant cells were lower than the rates of uptake by the wild-type strain. The pattern and amount of outer membrane protein in the P. putida tol-oprL mutants were not changed, suggesting that the transport defect was not in the outer membrane. Consistently, the uptake of radiolabeled glucose and glycerol in spheroplasts was defective in the P. putida tol-oprL mutant strains, suggesting that there was a defect at the cytoplasmic membrane level. Generation of a proton motive force appeared to be unaffected in these mutants. To rule out the possibility that the uptake defect was due to a lack of specific transporter proteins, the PutP symporter was overproduced, but this overproduction did not enhance proline uptake in the tol-oprL mutants. These results suggest that the Tol-OprL system is necessary for appropriate functioning of certain uptake systems at the level of the cytoplasmic membrane.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
August/28/1996
Abstract
Doxorubicin (DOX) and its daunosamine-modified derivative, 2-pyrrolino-DOX, which is 500-1000 times more active than DOX, were incorporated into agonistic and antagonistic analogs of luteinizing hormone-releasing hormone (LH-RH). The conjugation of DOX with LH-RH analogs was performed by using N-(9-fluorenylmethoxycarbonyl)-DOX-14-O-hemiglutarate, a dicarboxylic acid ester derivative of DOX. Coupling this derivative covalently to the epsilon-amino group of the D-Lys side chain of agonist [D-Lys6]LH-RH or antagonistic analog AC-D-Nal(2)-D-Phe(4Cl)-D-Pal(3)-Ser-Tyr-D-Lys-Leu-Arg-Pro-D-Ala-NH 2 [where Nal(2) = 3-(2-naphthyl)alanine, Pal(3) = 3-(3-pyridyl)alanine, and Phe(4CI) = 4-chlorophenylalanine] was followed by the removal of the 9-fluorenylmethoxycarbonyl protective group to yield cytotoxic derivatives of LH-RH analogs containing DOX. From these DOX containing LH-RH hybrids, intensely potent analogs with daunosamine-modified derivatives of DOX can be readily formed. Thus, cytotoxic LH-RH agonist containing DOX (AN-152) can be converted in a 66% yield by a reaction with a 30-fold excess of 4-iodobutyraldehyde in N,N-dimethylformamide into a derivative having 2-pyrrolino-DOX (AN-207). Hybrid molecules AN-152 and AN-207 fully preserve the cytotoxic activity of their radicals, DOX or 2-pyrrolino-DOX, respectively, in vitro, and also retain the high binding affinity of the peptide hormone portion of the conjugates to rat pituitary receptors for LH-RH. These highly potent cytotoxic analogs of LH-RH were designed as targeted anti-cancer agents for the treatment of various tumors that possess receptors for the carrier peptide. Initial in vivo studies show that the hybrid molecules are much less toxic than the respective cytotoxic radicals incorporated and significantly more active in inhibiting tumor growth.
Publication
Journal: International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity
December/12/2001
Abstract
OBJECTIVE
To assess the relationship between the mean physical activity level (PAL) and the time spent on activities of three different intensity levels in an elderly population. Data was compared with previously obtained data from a group of younger adults.
METHODS
Fourteen elderly women and 14 elderly men (61+/-4 y; 27+/-5 kg/m(2); 33+/-7% body fat), and 14 young women and 16 young men (27+/-5 y, 24+/-2 kg/m(2)).
METHODS
PAL was determined as average daily metabolic rate (ADMR) combined with a measurement of basal metabolic rate (BMR): PAL=ADMR/BMR. ADMR was measured with the doubly labeled water method. BMR was measured with a ventilated hood system. Time spent on activity and activity intensity was measured by using a tri-axial accelerometer (7x2x0.8 cm, 30 g) over a 2 week interval.
RESULTS
Mean PAL was 1.65+/-0.14. PAL was inversely related to the percentage of time spent on low-intensity activity (lying, sitting and standing), r= -0.43; P<0.05. Older subjects spent significantly more time at these activities than 20 to 35-y-old subjects (82+/-7% vs 65+/-7%; P<0.0001). A significant relation was not observed between PAL and the percentage of time spent on moderate (walking) or high (household activities, exercise and sports) intensity activity, or activity monitoring time (14.4+/-1.2 h/day).
CONCLUSIONS
In the elderly, spending relatively more time on low-intensity activities affects the mean PAL negatively. To obtain a higher PAL does not necessarily imply high-intensity activities like sports.
Publication
Journal: Physical Therapy
May/19/2002
Abstract
OBJECTIVE
The effects of different durations of rehabilitation sessions for the upper extremities (UEs) and lower extremities (LEs) on the recovery of interlimb coordination in hemiplegic gait in patients who have had a stroke were investigated.
METHODS
Fifty-three subjects who had strokes involving their middle cerebral arteries were assigned to rehabilitation programs with (1) an emphasis on the LEs, (2) an emphasis on the paretic UE, or (3) a condition in which the paretic arm (UE) and leg (LE) were immobilized with an inflatable pressure splint (control treatment). The 3 treatment regimens were applied for 30 minutes, 5 days a week, during the first 20 weeks after onset of stroke. All subjects also participated in a rehabilitation program 5 days a week that consisted of 15 minutes of UE exercises and 15 minutes of LE exercises in addition to a weekly 11/2-hour session of training in activities of daily living. A repeated-measures design was used. Differences among the 3 treatment regimens were evaluated in terms of comfortable and maximal walking speeds. In addition, mean continuous relative phase (CRP) between paretic arm and leg (PAL) movements and nonparetic arm and leg (NAL) movements and standard deviations of CRP of both limb pairs as a measurement of stability (variability) were evaluated.
RESULTS
Comfortable walking speed improved in the group that received interventions involving the LEs compared with the group that received interventions involving the UEs and the group that received the control treatment. No differences among the 3 treatment conditions were found for the mean CRP of NAL and PAL as well as the standard deviation of CRP of both limb pairs.
CONCLUSIONS
With the exception of an improved comfortable walking speed as a result of a longer duration of rehabilitation sessions, no differential effects of duration of rehabilitation sessions for the LEs and UEs on the variable we measured related to hemiplegic gait were found. Increasing walking speed, however, resulted in a larger mean CRP for both limb pairs, with increased stability and asymmetry of walking, indicating that walking speed influences interlimb coordination in hemiplegic gait.
Publication
Journal: Journal of Bacteriology
June/6/2005
Abstract
We have previously shown that the TolA protein is required for the correct surface expression of the Escherichia coli O7 antigen lipopolysaccharide (LPS). In this work, delta tolA and delta pal mutants of E. coli K-12 W3110 were transformed with pMF19 (encoding a rhamnosyltransferase that reconstitutes the expression of O16-specific LPS), pWQ5 (encoding the Klebsiella pneumoniae O1 LPS gene cluster), or pWQ802 (encoding the genes necessary for the synthesis of Salmonella enterica O:54). Both DeltatolA and delta pal mutants exhibited reduced surface expression of O16 LPS as compared to parental W3110, but no significant differences were observed in the expression of K. pneumoniae O1 LPS and S. enterica O:54 LPS. Therefore, TolA and Pal are required for the correct surface expression of O antigens that are assembled in a wzy (polymerase)-dependent manner (like those of E. coli O7 and O16) but not for O antigens assembled by wzy-independent pathways (like K. pneumoniae O1 and S. enterica O:54). Furthermore, we show that the reduced surface expression of O16 LPS in delta tolA and delta pal mutants was associated with a partial defect in O-antigen polymerization and it was corrected by complementation with intact tolA and pal genes, respectively. Using derivatives of W3110 delta tolA and W3110 delta pal containing lacZ reporter fusions to fkpA and degP, we also demonstrate that the RpoE-mediated extracytoplasmic stress response is upregulated in these mutants. Moreover, an altered O16 polymerization was also detected under conditions that stimulate RpoE-mediated extracytoplasmic stress responses in tol+ and pal+ genetic backgrounds. A Wzy derivative with an epitope tag at the C-terminal end of the protein was stable in all the mutants, ruling out stress-mediated proteolysis of Wzy. We conclude that the absence of TolA and Pal elicits a sustained extracytoplasmic stress response that in turn reduces O-antigen polymerization but does not affect the stability of the Wzy O-antigen polymerase.
Publication
Journal: Journal of Virology
July/11/1993
Abstract
The use of recombinant viruses for the expression of a wide array of foreign proteins has become commonplace during the last few years. Recently, we have described the construction and characterization of chimeric human immunodeficiency virus type 1 (HIV-1)-poliovirus genomes in which the gag and pol genes of HIV-1 have been substituted for the VP2 and VP3 capsid genes of the P1 capsid precursor region of poliovirus. Transfection of these RNAs into tissue culture cells results in replication of the RNA genome and expression of HIV-1-P1 fusion proteins (W. S. Choi, R. Pal-Ghosh, and C. D. Morrow, J. Virol. 65:2875-2883, 1991). Here we report on the encapsidation and amplification of the minireplicons to obtain sufficient quantities for biological characterization. To do this, HIV-1-poliovirus minireplicon genomes containing the gag or pol gene were transfected into cells previously infected with a recombinant vaccinia virus (VV-P1) which expresses the poliovirus capsid precursor protein, P1 (D. C. Ansardi, D. C. Porter, and C. D. Morrow, J. Virol. 65:2088-2092, 1991). The chimeric minireplicons replicated and expressed the appropriate HIV-1-P1 fusion proteins as determined by immunoprecipitation with HIV-1-specific antibodies. The encapsidated genomes were isolated by ultracentrifugation. Reinfection of cells with the encapsidated chimeric RNA genomes resulted in expression of the HIV-1-Gag-P1 or HIV-1-Pol-P1 fusion protein. Serial passaging of the encapsidated chimeric HIV-1-poliovirus genomes was accomplished by coinfecting cells with the encapsidated minireplicons and VV-P1, resulting in stocks of the encapsidated minireplicons. Northern (RNA) blot analysis of passaged material revealed that no detectable deletions of the chimeric genomes occurred during 14 serial passages. Infection of cells by the encapsidated minireplicons was blocked by antipoliovirus antibodies. Coinfection of cells with encapsidated minireplicons and type 1 Sabin poliovirus resulted in encapsidation of the chimeric genomes by wild-type poliovirus as measured by immunoprecipitation of the HIV-1-P1 fusion proteins with HIV-1-specific antibodies. The results of this study demonstrate the encapsidation of poliovirus minireplicons which express foreign proteins and point to the future use of this system as a potential vaccine vector.
Publication
Journal: European Journal of Clinical Nutrition
June/24/2002
Abstract
OBJECTIVE
Assessment of the effect of a lowered ambient temperature, ie 16 degrees C (61 degrees F), compared to 22 degrees C (72 degrees F), on energy intake (EI), energy expenditure (EE) and respiratory quotient (RQ) in men.
METHODS
Randomized within-subject design in which subjects stayed in a respiration chamber three times for 60 h each, once at 22 degrees C, and twice at 16 degrees C, wearing standardized clothing, executing a standardized daily activities protocol, and were fed in energy balance (EBI): no significant difference between EE and EI over 24 h). During the last 24 h at 22 degrees C, and once during the last 24 h at 16 degrees C, they were fed ad libitum.
METHODS
Nine dietary unrestrained male subjects (ages 24+/-5 y, body mass index (BMI) 22.7+/-2.1 kg/m(2), body weight 76.2+/-9.4 kg, height 1.83+/-0.06 m, 18+/-5% body fat).
RESULTS
At 16 degrees C (EB), EE (total 24 h EE) was increased to 12.9+/-2.0 MJ/day as compared to 12.2+/-2.2 MJ/day at 22 degrees C (P<0.01). The increase was due to increases in sleeping metabolic rate (SMR; the lowest EE during three consecutive hours with hardly any movements as indicated by radar): 7.6+/-0.7 vs 7.2+/-0.7 MJ/day (P<0.05) and diet-induced thermogenesis (DIT; EE-SMR, when activity induced energy expenditure as indicated by radar=0): 1.7+/-0.4 vs 1.0+/-0.4 MJ/day (P<0.01). Physical activity level (PAL; EE/SMR) was 1.63-1.68. At 16 degrees C compared to at 22 degrees C, rectal, proximal and distal skin temperatures had decreased (P<0.01). RQ was not different between the two ambient temperature situations. During ad libitum feeding, subjects overate by 32+/-12% (at 22 degrees C) and by 34+/-14% (at 16 degrees C). Under these circumstances, the decrease of rectal temperature at 16 degrees C was attenuated, and inversely related to percentage overeating (r(2)=0.7; P<0.01).
CONCLUSIONS
We conclude that at 16 degrees C, compared to 22 degrees C, energy metabolism was increased, due to increases in SMR and DIT. Overeating under ad libitum circumstances at 16 degrees C attenuated the decrease in rectal core body temperature.
Publication
Journal: Medical Education
September/29/2008
Abstract
OBJECTIVE
Peer-assisted learning (PAL) has been reported to have educational benefits in cross-year, small-group teaching in other contexts. Accordingly, we explored whether senior medical students are effective tutors for their junior peers in clinical skills education, and how the participants in the learning triad (tutors, learners and simulated patients [SPs]) perceive the learning environment created in PAL.
METHODS
Year 2 students were randomly allocated to one of two groups for skills training. Group 1 (n = 64) were tutored by volunteer Year 6 students, and Group 2 (n = 67) by paid doctors. The results of both groups in a clinical skills examination were compared using an independent samples t-test. Qualitative data, obtained from Year 2 students (n = 125) by written questionnaire and Year 6 students (n = 11) and SPs (n = 3) by focus group interviews, were analysed for themes.
RESULTS
Students receiving PAL did at least as well in the clinical skills examination as students with qualified tutors (difference in mean total score: 0.7 marks out of 112; 95% confidence interval--8 to 2.4). The PAL environment was perceived as 'comfortable' and fostered the development of confidence in all participants. Peer tutors created a more active learning environment than doctor tutors for both learners and SPs and reported personal benefits from teaching.
CONCLUSIONS
With appropriate support, volunteer Year 6 student tutors are as effective as graduate doctors for small-group structured tutorials in clinical skills. Educational relationships were forged between all participants in the learning triad.
Publication
Journal: Molecular Plant Pathology
February/10/2013
Abstract
The moss Physcomitrella patens is an evolutionarily basal model system suitable for the analysis of plant defence responses activated after pathogen assault. Upon infection with the necrotroph Botrytis cinerea, several defence mechanisms are induced in P. patens, including the fortification of the plant cell wall by the incorporation of phenolic compounds and the induced expression of related genes. Botrytis cinerea infection also activates the accumulation of reactive oxygen species and cell death with hallmarks of programmed cell death in moss tissues. Salicylic acid (SA) levels also increase after fungal infection, and treatment with SA enhances transcript accumulation of the defence gene phenylalanine ammonia-lyase (PAL) in P. patens colonies. The expression levels of the genes involved in 12-oxo-phytodienoic acid (OPDA) synthesis, including lipoxygenase (LOX) and allene oxide synthase (AOS), increase in P. patens gametophytes after pathogen assault, together with a rise in free linolenic acid and OPDA concentrations. However, jasmonic acid (JA) could not be detected in healthy or infected tissues of this plant. Our results suggest that, although conserved defence signals, such as SA and OPDA, are synthesized and are probably involved in the defence response of P. patens against B. cinerea infection, JA production appears to be missing. Interestingly, P. patens responds to OPDA and methyl jasmonate by reducing moss colony growth and rhizoid length, suggesting that jasmonate perception is present in mosses. Thus, P. patens can provide clues with regard to the evolution of different defence pathways in plants, including signalling and perception of OPDA and jasmonates in nonflowering and flowering plants.
Publication
Journal: Journal of Periodontology
February/7/1994
Abstract
The purpose of this study was to identify factors which might affect the healing response in intrabony defects treated with guided tissue regeneration. Selected sites presented with deep periodontal lesions with 1, 2, and 3 wall combination intrabony component of 6.1 +/- 2.5 mm. The significance of patient, tooth, and defect characteristics and surgical parameters as predictor variables affecting the regenerative outcome before and following the removal of the barrier membrane was assessed. Outcome was measured as tissue gain under the membrane, regenerated probing attachment level (PAL), and bone fill. The total depth of the intrabony component and the radiographic defect angle significantly affected the amount of tissue gain. Seventy-five percent (75%) of the variability of regenerated PAL and bone fill was explained in terms of tissue gain under the membrane, radiographic width of the defect angle, full mouth bleeding score, and presence or absence of flap coverage of the newly formed tissue. Control of the identified predictor variables might improve the extent and predictability of guided tissue regeneration in the treatment of deep intrabony defects.
Publication
Journal: Molecular Plant-Microbe Interactions
December/17/2008
Abstract
Colonization of roots by selected strains of fluorescent Pseudomonas spp. can trigger induced systemic resistance (ISR) against foliar pathogens in a plant species-specific manner. It has been suggested that early responses in cell suspension cultures in response to rhizobacterial elicitors, such as generation of active oxygen species (AOS) and extracellular medium alkalinization (MA), are linked to the development of ISR in whole plants. Perception of flagellin was demonstrated to elicit ISR in Arabidopsis, and bacterial lipopolysaccharides (LPS) have been shown to elicit several defense responses and to act as bacterial determinants of ISR in various plant species. In the present study, the LPS-containing cell walls, the pyoverdine siderophores, and the flagella of Pseudomonas putida WCS358, P. fluorescens WCS374, and P. fluorescens WCS417, which are all known to act as elicitors of ISR in selected plant species, were tested for their effects on the production of AOS, MA, elevation of cytoplasmic Ca(2+) ([Ca(2+)](cyt)), and defense-related gene expression in tobacco suspension cells. The LPS of all three strains, the siderophore of WCS374, and the flagella of WCS358 induced a single, transient, early burst of AOS, whereas the siderophores of WCS358 and WCS417 and the flagella of WCS374 and WCS417 did not. None of the compounds caused cell death. Once stimulated by the active compounds, the cells became refractory to further stimulation by any of the active elicitors, but not to the elicitor cryptogein from the oomycete Phytophthora cryptogea, indicating that signaling upon perception of the different rhizobacterial compounds rapidly converges into a common response pathway. Of all compounds tested, only the siderophores of WCS358 and WCS417 did not induce MA; the flagella of WCS374 and WCS417, although not active as elicitors of AOS, did induce MA. These results were corroborated by using preparations from relevant bacterial mutants. The active rhizobacterial elicitors led to a rapid increase in [Ca(2+)](cyt), peaking at 6 min, whereas the inactive siderophores of WCS358 and WCS417 elicited a single spike at 1 min. Elicitation of the cells by cell-wall LPS of WCS358 or the siderophore of WCS374 induced a weak, transient expression of several defense-related genes, including PAL and GST. The spectrum of early responses of the suspension cells was not matched by the expression of ISR in whole tobacco plants against Erwinia carotovora pv. carotovora. Of the live bacterial strains, only WCS358 elicited significant ISR, but application of the LPS or the siderophore of all three strains also elicited ISR. Notably, the absence of elicitation of AOS and MA in suspension-cultured cells but induction of ISR in whole plants by the siderophore of WCS358, which was lost upon treatment with the siderophore-minus mutant of WCS358, indicates that the early responses in suspension cells are not predictive of the ability to induce ISR in whole plants. Possible explanations for these discrepancies are discussed.
Publication
Journal: Gastrointestinal Endoscopy
January/22/2012
Abstract
BACKGROUND
The self-expandable metal stent (SEMS) can alleviate malignant colonic obstruction and avoid emergency decompressive surgery.
OBJECTIVE
To document performance, safety, and effectiveness of colorectal stents used per local standards of practice in patients with malignant large-bowel obstruction to avoid palliative stoma surgery in incurable patients (PAL) and facilitate bowel decompression as a bridge to surgery for curable patients (BTS).
METHODS
Prospective clinical cohort study.
METHODS
Two global registries with 39 academic and community centers.
METHODS
This study involved 447 patients with malignant colonic obstruction who received stents (255 PAL, 182 BTS, 10 no indication specified).
METHODS
Colorectal through-the-scope SEMS placement.
METHODS
The primary endpoint was clinical success at 30 days, defined as the patient's ability to maintain bowel function without adverse events related to the procedure or stent. Secondary endpoints were procedural success, defined as successful stent placement in the correct position, symptoms of persistent or recurrent colonic obstruction, and complications.
RESULTS
The procedural success rate was 94.8% (439/463), and the clinical success rates were 90.5% (313/346) as assessed on a per protocol basis and 71.6% (313/437) as assessed on an intent-to-treat basis. Complications included 15 (3.9%) perforations, 3 resulting in death, 7 (1.8%) migrations, 7 (1.8%) cases of pain, and 2 (0.5%) cases of bleeding.
CONCLUSIONS
No control group. No primary endpoint analysis data for 25% of patients.
CONCLUSIONS
This largest multicenter, prospective study of colonic SEMS placement demonstrates that colonic SEMSs are safe and highly effective for the short-term treatment of malignant colorectal obstruction, allowing most curable patients to have 1-step resection without stoma and providing most incurable patients minimally invasive palliation instead of surgery. The risk of complications, including perforation, was low.
Publication
Journal: Journal of Science and Medicine in Sport
July/25/2011
Abstract
Measurement in behavioural epidemiology depends on high resolution and precise and accurate measures of the behaviour of interest. Few questionnaires in the adult population are able to simultaneously collect the multidimensional information that is emerging as being important in the relationship between behaviour and health. This project had two objectives: (1) to develop an adult version of the computer-delivered Multimedia Activity Recall for Children and Adolescents (MARCA), a 24-h activity recall instrument that can measure use-of-time and estimate energy expenditure and (2) to determine the test-retest reliability and convergent validity of the developed adult MARCA. Thirty-eight healthy subjects (mean±SD, 31.7±12.1 yr) completed two recalls of the adult MARCA within 24-h and accelerometer counts were measured on 30 of the subjects. Bland-Altman analysis and intraclass correlation coefficients (ICC) were used to quantify the test-retest reliability of the adult MARCA. Spearman rank correlation coefficients (rho) were used to quantify convergent validity of the adult MARCA compared to accelerometer counts. The test-retest reliability coefficients of the adult MARCA were high with intra-class coefficients ranging from 0.99 to 1.00. Moderate to strong validity was observed for physical activity level (PAL) (MET.min score of accelerometer wear time) and accelerometer counts per minute (rho=0.72). The adult MARCA is a valid and reliable self-report measure of use-of-time and energy expenditure, capable of a wide variety of flexible use-of-time analyses related to a wide range of behaviours.
Publication
Journal: Avian Diseases
May/30/2006
Abstract
The purpose of this study was to develop a multiplex polymerase chain reaction (PCR) protocol useful in the virulence genotyping of Salmonella spp. with the idea that genotyping could augment current Salmonella characterization and typing methods. Seventeen genes associated with Salmonella invasion, fimbrial production, toxin production, iron transport, and intramacrophage survival were targeted by three PCR reactions. Most of these genes are required for full Salmonella virulence in a murine model, and many are also located on Salmonella pathogenicity islands (PAIs) and are associated with type III secretion systems (TTSSs). Once the success of procedures that used positive and negative control strains was verified, the genotypes of 78 Salmonella isolates incriminated in avian salmonellosis (primarily from sick, commercially reared chickens and turkeys) and 80 Salmonella isolates from apparently healthy chickens or turkeys were compared. Eleven of the 17 genes tested (invA, orgA, prgH, tolC, spaN [invJ], sipB, sitC, pagC, msgA, spiA, and iroN) were found in all of the isolates. Another (sopB) was present in all isolates from sick birds and all but one isolate from healthy birds. The remaining five genes (lpfC, cdtB, sifA, pefA, and spvB) were found in 10%-90% of the isolates from sick birds and 3.75%-90% of the healthy birds. No significant differences in the occurrence of these genes between the two groups of isolates were detected. These results suggest that these virulence genes, and presumably the PAls and TTSSs with which they are associated, are widely distributed among Salmonella isolates of birds, regardless of whether their hosts of origin have been identified as having salmonellosis.
Publication
Journal: American Journal of Clinical Nutrition
February/24/2011
Abstract
BACKGROUND
There is an assumption that people in developing countries have a higher total energy expenditure (TEE) and physical activity level (PAL) than do people in developed nations, but few objective data for this assertion exist.
OBJECTIVE
We conducted a meta-analysis of TEE and PAL by using data from countries that have a low or middle human development index (HDI) compared with those with a high HDI to better understand how energy-expenditure variables are associated with development status and population differences in body size.
METHODS
We performed a literature search for studies in which energy expenditure was measured by using doubly labeled water. Mean data on age, weight, body mass index (BMI; in kg/m(2)), TEE, and PAL were extracted, and HDI status was assessed. Pooled estimates of the mean effect by sex were obtained, and the extent to which age, weight, HDI status, and year of publication explained heterogeneity was assessed.
RESULTS
A total of 98 studies (14 studies from low- or middle-HDI countries) that represented 183 cohorts and 4972 individuals were included. Mean (±SE) BMI was lower in countries with a low or middle HDI than in those with a high HDI for both men and women (22.7 ± 1.0 compared with 26.0 ± 0.7, respectively, in men and 24.3 ± 0.7 compared with 26.6 ± 0.4, respectively, in women). In meta-regression models, there was an inverse association of age (P < 0.001) and a positive association of weight (P < 0.001) with TEE for both sexes; there was an association of age only in men with PAL (P < 0.001). There was no association of HDI status with either TEE or PAL.
CONCLUSIONS
TEE adjusted for weight and age or PAL did not differ significantly between developing and industrialized countries, which calls into question the role of energy expenditure in the cause of obesity at the population level.
Publication
Journal: International Immunology
May/1/2002
Abstract
Transitional immature B cells undergo apoptosis and fail to proliferate in response to BCR cross-linking, thus representing a target for negative selection of potentially autoreactive B cells in vivo. In agreement with recent reports, transitional B cells were divided into developmentally contiguous subsets based on their surface expression of CD23. When transferred, CD23(+) transitional B cells readily localized to the splenic follicles and the outer PALS. Compared with CD23(-) transitional B cells, CD23(+) transitional B cells proliferated more vigorously and were rescued from BCR-induced apoptosis to a greater degree, by T cell help signals. However, both CD23(-) and CD23(+) transitional B cells failed to up-regulate CD86 (B7-2) in response to BCR ligation. These findings demonstrate that phenotypically defined subsets within the transitional B cell population are functionally distinct. Specifically, responsiveness to T cell help is a late acquisition corresponding to the stage when the B cells gain access to peripheral compartments enriched in antigen and activated T cells. The failure of transitional B cells to up-regulate CD86 to BCR-mediated stimulation suggests a unique interaction between transitional B cells and T cells with implications for tolerance in the T cell compartment.
Publication
Journal: Chest
November/19/2006
Abstract
OBJECTIVE
To assess whether the presence and duration of air leaks after lobectomy are associated with an increased incidence of cardiopulmonary complications.
METHODS
Propensity score analysis was used on 726 patients undergoing pulmonary lobectomy from 1995 through 2004 to form three well-matched pairs of patients: patients with prolonged air leak (PAL) >> 7 days] and without air leak; patients with short air leak (SAL) [< or = 7 days] and without air leak; and patients with SAL and PAL. These matched groups were then compared to assess postoperative hospital stay and early outcome.
RESULTS
Patients with SAL had a longer postoperative hospital stay compared to patients without air leak (8.6 days vs 7.8 days, respectively; p < 0.0001) but had similar morbidity and mortality. Patients with PAL had a longer postoperative hospital stay compared to patients without air leak (16.2 days vs 8.3 days, respectively; p < 0.0001) and with SAL (16.9 days vs 9 days, respectively; p < 0.0001), but similar cardiopulmonary complications were noted between the groups. Patients with PAL had a higher rate of empyema compared to patients without air leak and with SAL (8.2% vs 0%, p = 0.01 and 10.4% vs.1.1%, p = 0.01, respectively).
CONCLUSIONS
The presence of air leak was not associated with an increased incidence of cardiopulmonary morbidity but was associated with an increased risk of empyema. Future prospective studies are needed to confirm safety of fast track in patients with air leak.
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