European Journal of Applied Physiology and Occupational Physiology, 1986
To investigate whether ventilation frequency could be entrained to a sub-harmonic of the exercise... more To investigate whether ventilation frequency could be entrained to a sub-harmonic of the exercise rhythm, 19 experimentally naive male volunteers were tested during steady state bicycle ergometry and arm cranking under conditions of constant applied workload. Each exercise was performed at two separate ventilatory loads, one within the linear range and the other in the curvilinear range of ventilatory response to exercise. A preferred exercise rhythm was initially adopted (4 rain.) followed by forced incremented and decremented rhythm changes each lasting 3 min during a 12 rain exercise period. Ventilation, pedal pulse train and heart rate were sampled at 17 Hz on a PDP 11/23 computer. Ratios of limb frequency to dominant respiratory frequency were determined following Fourier analysis of these signals. Data that lay within + 0.05 of an integer and half-integer ratio were accepted as indices of entrainment, provided that the observed entrained scores were statistically significant. Ventilation frequency showed a clear, but intermittent tendency to entrain with limb frequency. This tendency was greater during bicycle ergometry, possibly as a consequence of task familiarisation, although both exercise entrainments were independent of workload. No difference between preferred versus varied exercise rhythm was evident, but more entrainment (p < 0.01) was observed during a decremental change in exercise rhythm. These responses do not appear to support an appreciable role for limb-based afferents in the control of entrainment. The results of this study provide evidence that exercise rhythm has some regulatory role in the control of breathing during moderate rhythmical laboratory-based exercise ergometry.
The Center for New York City Neighborhoods (CNYCN) was created in 2008 to coordinate and expand s... more The Center for New York City Neighborhoods (CNYCN) was created in 2008 to coordinate and expand services to New York City residents at risk of losing their home to foreclosure. Through comprehensive citywide programming that includes legal services, housing counseling, community outreach and education. CNYCN is proposing to create a call center that will be organized as a first line
The purpose of this study was to evaluate the feasibility of metabonomics technology for developi... more The purpose of this study was to evaluate the feasibility of metabonomics technology for developing a rapid-throughput toxicity screen using 2 known hepatotoxicants: carbon tetrachloride (CCl 4 ) and ␣-naphthylisothiocyanate (ANIT) and 2 known nephrotoxicants: 2-bromoethylamine (BEA) and 4-aminophenol (PAP). In addition, the diuretic furosemide (FURO) was also studied. Single doses of CCl 4 (0.1 and 0.5 ml/kg), ANIT (10 and 100 mg/kg), BEA (15 and 150 mg/kg), PAP (15 and 150 mg/kg) and FURO (1 and 5 mg) were administered as single IP or oral doses to groups of 4 male Wistar rats/dose. Twenty-four-h urine samples were collected pretest, daily through Day 4, and on Day 10 (high dose CCl 4 and BEA only). Blood samples were taken on Days 1, 2, and 4 or 1, 4, and 10 for clinical chemistry assessment, and the appropriate target organ was examined microscopically. NMR spectra of urine were acquired and the data processed and subjected to principal component analyses (PCA). The results demonstrated that the metabonomic approach could readily distinguish the onset and reversal of toxicity with good agreement between clinical chemistry and PCA data. In at least 2 instances (ANIT and BEA), PCA analysis suggested effects at low doses, which were not as evident by clinical chemistry or microscopic analysis. Furosemide, which had no effect at the doses employed, did not produce any changes in PCA patterns. These data support the contention that the metabonomic approach represents a promising new technology for the development of a rapid throughput in vivo toxicity screen.
Glycoprotein H/glycoprotein L (gH/gL) complexes of herpesviruses are required for fusion of infec... more Glycoprotein H/glycoprotein L (gH/gL) complexes of herpesviruses are required for fusion of infecting virions with host cell membranes. In human cyto- megalovirus (HCMV), neutralizing monoclonal anti- bodies (MAb) specific for gH inhibit the transfer of a fluorescent probe to the host cell from labelled virus particles. In similar fashion, in the present study, neutralizing gH-specific MAb inhibited HCMV- induced fusion-from-without
Antimicrobial Resistance and Infection Control, 2015
Extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae are often susceptible in vitro ... more Extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae are often susceptible in vitro to β-lactam/β-lactamase inhibitor (BLBLI) combination antibiotics, but their use has been limited by concerns of clinical inefficacy. We aimed to compare outcomes between patients treated with BLBLIs and carbapenems for bloodstream infection (BSI) caused by cefotaxime non-susceptible (likely ESBL- or AmpC β-lactamase-producing) Escherichia coli and Klebsiella pneumoniae. All adult patients with a BSI caused by cefotaxime non-susceptible E. coli or K. pneumoniae were included from May 2012-May 2013. We compared outcomes between patients who had definitive monotherapy with a carbapenem to those who had definitive monotherapy with a BLBLI. There were 92 BSIs that fulfilled the microbiological inclusion criteria. 79 (85.9%) were caused by E. coli and 13 (14.1%) by K. pneumoniae. Four out of 23 (17.4%) patients treated with carbapenem monotherapy and 2 out of 24 (8.3%) patients treated with BLBLI monotherapy died (adjusted HR for survival 0.91, 95% CI 0.13 to 6.28; p = 0.92). The time to resolution of systemic inflammatory response syndrome (SIRS) criteria did not vary between the treatment groups (adjusted HR 0.91, 95% CI 0.32 to 2.59; p = 0.97). The length of hospital admission post-positive blood culture was slightly longer in patients treated with BLBLIs (median duration 15 vs. 11 days), although this was not significant (adjusted HR 0.62; 95% CI 0.27 to 1.42; p = 0.26). There were no significant differences in subsequent isolation of carbapenem resistant organisms (4.3% vs. 4.2%, p = 1.0), C. difficile infection (13.0% vs. 8.3%, p = 0.67) or relapsed BSI (0% vs. 2%, p = 0.23). BLBLIs appear to have a similar efficacy to carbapenems in the treatment of cefotaxime-resistant E. coli and K. pneumoniae bloodstream infections. Directed therapy with a BLBLI, when susceptibility is proven, may represent an appropriate carbapenem-sparing option.
Elevated B-type natriuretic peptide (BNP) regulates cGMP-phosphodiesterase activity. Its elevatio... more Elevated B-type natriuretic peptide (BNP) regulates cGMP-phosphodiesterase activity. Its elevation is regarded as an early compensatory response to cardiac failure where it can facilitate sympathovagal balance and cardiorenal homeostasis. However, recent reports suggest a paradoxical proadrenergic action of BNP. Because phosphodiesterase activity is altered in cardiovascular disease, we tested the hypothesis that BNP might lose its efficacy by minimizing the action of cGMP on downstream pathways coupled to neurotransmission. BNP decreased norepinephrine release from atrial preparations in response to field stimulation and also significantly reduced the heart rate responses to sympathetic nerve stimulation in vitro. Using electrophysiological recording and fluorescence imaging, BNP also reduced the depolarization evoked calcium current and intracellular calcium transient in isolated cardiac sympathetic neurons. Pharmacological manipulations suggested that the reduction in the calcium...
The prevalence of carbapenemase producing Enterobacteriaceae (CPE) has been increasing 25 worldwi... more The prevalence of carbapenemase producing Enterobacteriaceae (CPE) has been increasing 25 worldwide. bla IMP has been reported as the predominant carbapenemase-encoding gene 26 within Enterobacteriaceae in Australia. However, there is limited data currently available on 27 CPE from Queensland, Australia. A total of 58 CPE isolates were isolated between July 2009 28 and March 2014 from Queensland hospitals. The clonality of isolates was determined by rep-29 PCR Diversilab TM . The isolates were investigated for the resistance mechanisms by PCR 30 carbapenemase, ESBL, AmpC β-lactamase, aminoglycoside resistance and plasmid-mediated 31 quinolone resistance genes. The plasmid types associated with carbapenemase encoding 32 genes were characterised. The majority of the CPE were E. cloacae (n=29). The majority of 33
Background: Patients with BSIs caused by gram-negative organisms have a high rate of mortality. O... more Background: Patients with BSIs caused by gram-negative organisms have a high rate of mortality. Our objectives were to identify the predictors of mortality associated with gram-negative BSIs in ICUs. Methods: A multicenter, retrospective cohort study between 2005 and 2007 was performed, including 808 patients with BSIs due to Enterobacteriaceae. Results: 265 (32.8%) patients were identified as having BSI with onset in the ICU. The BSIs were caused by E. coli (n = 90), Klebsiella spp. (n = 107) or Enterobacter spp. (n = 68). The overall 28-day mortality rate was 30.1% (80 of 265). In multivariate analysis, significant predictors of mortality were APACHE Π severity score > 25 at the time of infection (OR 10.7 [CI 4.5 - 25.7], P < 0.001) and need for vasopressor use (OR 4.2 [2.2 - 8.0], P < 0.001). In multivariate analysis of patients with the highest quartile of Apache Π scores, male sex (OR 4.82 [CI 1.15 - 20.29], P = 0.03) and vasopressor use (OR 4.07 [CI 1.1 - 15.1], P = 0...
Background: Extended-spectrum beta-lactamases (ESBLs) commonly found in Enterobacteriaceae have b... more Background: Extended-spectrum beta-lactamases (ESBLs) commonly found in Enterobacteriaceae have been of TEM and SHV types in the United States. However, detection of CTX-M-type ESBLs is increasingly reported. Methods: Bacteremic isolates of Escherichia coli and Klebsiella pneumoniae were collected at three tertiary medical centers in Northeastern United States (Pennsylvania, New York, and Massachusetts) between 2005 and 2007. ESBL producing isolates were identified by standard phenotypic methods and characterized by PCR and sequencing. Results: A total of 855 bacteremic isolates were available for study. Sixty-four isolates (7.5%; 47 K. pneumoniae and 17 E. coli) produced ESBLs. The ESBL types observed in K. pneumoniae were SHV (85%), KPC (19%), and CTX-M (2%). Specific SHV types included SHV-2a, 5, 7, 12, 30 and 31. All KPC-positive isolates were from the New York site and produced either KPC-2 or 3. In E. coli, CTX-M was the most common (41%), followed by SHV (35%) and TEM (6%). C...
Antimicrobial agents and chemotherapy, Jan 13, 2015
The novel extended-spectrum β-lactamase (ESBL), PME-1, was first described in 2010 from a Pseudom... more The novel extended-spectrum β-lactamase (ESBL), PME-1, was first described in 2010 from a Pseudomonas aeruginosa strain obtained from multiple clinical specimens from a single patient admitted to University of Pittsburgh Medical Center in 2008.….
Pulse modulated fluorescence has increasingly been used as an ecological tool to examine changes ... more Pulse modulated fluorescence has increasingly been used as an ecological tool to examine changes in the vertical distribution of microphytobenthic cells within the upper layers of estuarine sediments (most often using the minimum fluorescence yield F o ) as well as to indicate the health of the community (using the maximum PS II quantum efficiency F v /F m ). However, the practicalities of in situ measurements, often dictates that short dark adaptation periods must be used (∼15 min). The use of far-red light as an alternative to dark adaptation was investigated in natural migratory microphytobenthic biofilms and artificial non-migratory biofilms. Prolonged periods of darkness (∼24 h) were not adequate to achieve 'true' measurements of F o and F v /F m , which require complete oxidation of Q A and full reversal of non-photochemical quenching (NPQ). In some instances, stable values were only achieved using far-red light. Prolonged exposure to dark/far-red light led to a downwards migration of cells in natural assemblages, as seen by a reduction in both F o and the maximum fluorescence yield (F m ). In non-migratory biofilms, F m increased in the dark and far-red treatments, indicating a reversal of NPQ, whereas F o decreased in far-red light but increased in the dark. It is suggested that far-red light and darkness differentially affected the balance between NPQ reversal and Q A oxidation that lead to the measured F o yield. The use of far-red light as an alternative to dark adaptation is discussed and the implications of short (e.g., 15 min) dark adaptation times used in situ are discussed with reference to the vertical migration of cells within sediment biofilms.
Pulse amplitude modulated (PAM) fluorescence has been used as a proxy of microphytobenthic biomas... more Pulse amplitude modulated (PAM) fluorescence has been used as a proxy of microphytobenthic biomass after a dark adaptation period of 15 min to stabilise the minimum fluorescence yield (F o 15 ). This methodology was investigated for in situ migratory and ex situ engineered non-migratory biofilms, comparing dark adaptation to low (5% ambient) and far-red light treatments over different emersion periods. Far-red and low light reduced potential errors resulting from light history effects, by reversal of non-photochemical quenching after 5 min of treatment, compared to over 10 min required by conventional dark adaptation. An in situ decline of minimum fluorescence yield over 15 min was observed during the dark adaptation for migratory biofilms, but was not observed in the nonmigratory biofilms indicating that the major cause of decline was downward vertical migration of cells into the sediment. This pattern occurred in far-red light after 10 min, but not for the low light treatment, indicating that low light maintained the biomass at the 15 PSII photochemical efficiency after a saturating pulse, after 10 s or 5, 10 and 15 min of treatment, respectively NPQ Non-photochemical fluorescence quenching PPFD
... SU Gerbersdorf (*) Institute of Hydraulic Engineering, University of Stuttgart, Pfaffenwaldri... more ... SU Gerbersdorf (*) Institute of Hydraulic Engineering, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany e-mail: Sabine.Gerbersdorf@iws.uni-stuttgart.de J Soils Sediments (2009) 9:640652 DOI 10.1007/s11368-009-0142-5 Page 2. Keywords CSM . ...
Neuronal nicotinic acetylcholine receptors (nAChRs) are a family of ligand gated ion channels whi... more Neuronal nicotinic acetylcholine receptors (nAChRs) are a family of ligand gated ion channels which are widely distributed in the human brain. Multiple subtypes of these receptors exist, each with individual pharmacological and functional profiles. They mediate the effects of nicotine, a widely used drug of abuse, are involved in a number of physiological and behavioural processes and are additionally implicated in a number of pathological conditions such as Alzheimer's disease, Parkinson's disease and schizophrenia. The nAChRs have a pentameric structure composed of five membrane spanning subunits, of which nine different types have thus far been identified and cloned. The multiple subunits identified provide the basis for the heterogeneity of structure and function observed in the nAChR subtypes and are responsible for the individual characteristics of each. A substantial amount of information on human nAChR structure and function has come from studies on neuroblastoma cel...
Page 1. Eur. J. Phycol. (2002), 37: 485492. # 2002 British Phycological Society DOI: 10.1017\S09... more Page 1. Eur. J. Phycol. (2002), 37: 485492. # 2002 British Phycological Society DOI: 10.1017\S0967026202003888 Printed in the United Kingdom 485 Determination of microphytobenthic biomass using pulse-amplitude modulated minimum fluorescence ...
European Journal of Applied Physiology and Occupational Physiology, 1986
To investigate whether ventilation frequency could be entrained to a sub-harmonic of the exercise... more To investigate whether ventilation frequency could be entrained to a sub-harmonic of the exercise rhythm, 19 experimentally naive male volunteers were tested during steady state bicycle ergometry and arm cranking under conditions of constant applied workload. Each exercise was performed at two separate ventilatory loads, one within the linear range and the other in the curvilinear range of ventilatory response to exercise. A preferred exercise rhythm was initially adopted (4 rain.) followed by forced incremented and decremented rhythm changes each lasting 3 min during a 12 rain exercise period. Ventilation, pedal pulse train and heart rate were sampled at 17 Hz on a PDP 11/23 computer. Ratios of limb frequency to dominant respiratory frequency were determined following Fourier analysis of these signals. Data that lay within + 0.05 of an integer and half-integer ratio were accepted as indices of entrainment, provided that the observed entrained scores were statistically significant. Ventilation frequency showed a clear, but intermittent tendency to entrain with limb frequency. This tendency was greater during bicycle ergometry, possibly as a consequence of task familiarisation, although both exercise entrainments were independent of workload. No difference between preferred versus varied exercise rhythm was evident, but more entrainment (p < 0.01) was observed during a decremental change in exercise rhythm. These responses do not appear to support an appreciable role for limb-based afferents in the control of entrainment. The results of this study provide evidence that exercise rhythm has some regulatory role in the control of breathing during moderate rhythmical laboratory-based exercise ergometry.
The Center for New York City Neighborhoods (CNYCN) was created in 2008 to coordinate and expand s... more The Center for New York City Neighborhoods (CNYCN) was created in 2008 to coordinate and expand services to New York City residents at risk of losing their home to foreclosure. Through comprehensive citywide programming that includes legal services, housing counseling, community outreach and education. CNYCN is proposing to create a call center that will be organized as a first line
The purpose of this study was to evaluate the feasibility of metabonomics technology for developi... more The purpose of this study was to evaluate the feasibility of metabonomics technology for developing a rapid-throughput toxicity screen using 2 known hepatotoxicants: carbon tetrachloride (CCl 4 ) and ␣-naphthylisothiocyanate (ANIT) and 2 known nephrotoxicants: 2-bromoethylamine (BEA) and 4-aminophenol (PAP). In addition, the diuretic furosemide (FURO) was also studied. Single doses of CCl 4 (0.1 and 0.5 ml/kg), ANIT (10 and 100 mg/kg), BEA (15 and 150 mg/kg), PAP (15 and 150 mg/kg) and FURO (1 and 5 mg) were administered as single IP or oral doses to groups of 4 male Wistar rats/dose. Twenty-four-h urine samples were collected pretest, daily through Day 4, and on Day 10 (high dose CCl 4 and BEA only). Blood samples were taken on Days 1, 2, and 4 or 1, 4, and 10 for clinical chemistry assessment, and the appropriate target organ was examined microscopically. NMR spectra of urine were acquired and the data processed and subjected to principal component analyses (PCA). The results demonstrated that the metabonomic approach could readily distinguish the onset and reversal of toxicity with good agreement between clinical chemistry and PCA data. In at least 2 instances (ANIT and BEA), PCA analysis suggested effects at low doses, which were not as evident by clinical chemistry or microscopic analysis. Furosemide, which had no effect at the doses employed, did not produce any changes in PCA patterns. These data support the contention that the metabonomic approach represents a promising new technology for the development of a rapid throughput in vivo toxicity screen.
Glycoprotein H/glycoprotein L (gH/gL) complexes of herpesviruses are required for fusion of infec... more Glycoprotein H/glycoprotein L (gH/gL) complexes of herpesviruses are required for fusion of infecting virions with host cell membranes. In human cyto- megalovirus (HCMV), neutralizing monoclonal anti- bodies (MAb) specific for gH inhibit the transfer of a fluorescent probe to the host cell from labelled virus particles. In similar fashion, in the present study, neutralizing gH-specific MAb inhibited HCMV- induced fusion-from-without
Antimicrobial Resistance and Infection Control, 2015
Extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae are often susceptible in vitro ... more Extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae are often susceptible in vitro to β-lactam/β-lactamase inhibitor (BLBLI) combination antibiotics, but their use has been limited by concerns of clinical inefficacy. We aimed to compare outcomes between patients treated with BLBLIs and carbapenems for bloodstream infection (BSI) caused by cefotaxime non-susceptible (likely ESBL- or AmpC β-lactamase-producing) Escherichia coli and Klebsiella pneumoniae. All adult patients with a BSI caused by cefotaxime non-susceptible E. coli or K. pneumoniae were included from May 2012-May 2013. We compared outcomes between patients who had definitive monotherapy with a carbapenem to those who had definitive monotherapy with a BLBLI. There were 92 BSIs that fulfilled the microbiological inclusion criteria. 79 (85.9%) were caused by E. coli and 13 (14.1%) by K. pneumoniae. Four out of 23 (17.4%) patients treated with carbapenem monotherapy and 2 out of 24 (8.3%) patients treated with BLBLI monotherapy died (adjusted HR for survival 0.91, 95% CI 0.13 to 6.28; p = 0.92). The time to resolution of systemic inflammatory response syndrome (SIRS) criteria did not vary between the treatment groups (adjusted HR 0.91, 95% CI 0.32 to 2.59; p = 0.97). The length of hospital admission post-positive blood culture was slightly longer in patients treated with BLBLIs (median duration 15 vs. 11 days), although this was not significant (adjusted HR 0.62; 95% CI 0.27 to 1.42; p = 0.26). There were no significant differences in subsequent isolation of carbapenem resistant organisms (4.3% vs. 4.2%, p = 1.0), C. difficile infection (13.0% vs. 8.3%, p = 0.67) or relapsed BSI (0% vs. 2%, p = 0.23). BLBLIs appear to have a similar efficacy to carbapenems in the treatment of cefotaxime-resistant E. coli and K. pneumoniae bloodstream infections. Directed therapy with a BLBLI, when susceptibility is proven, may represent an appropriate carbapenem-sparing option.
Elevated B-type natriuretic peptide (BNP) regulates cGMP-phosphodiesterase activity. Its elevatio... more Elevated B-type natriuretic peptide (BNP) regulates cGMP-phosphodiesterase activity. Its elevation is regarded as an early compensatory response to cardiac failure where it can facilitate sympathovagal balance and cardiorenal homeostasis. However, recent reports suggest a paradoxical proadrenergic action of BNP. Because phosphodiesterase activity is altered in cardiovascular disease, we tested the hypothesis that BNP might lose its efficacy by minimizing the action of cGMP on downstream pathways coupled to neurotransmission. BNP decreased norepinephrine release from atrial preparations in response to field stimulation and also significantly reduced the heart rate responses to sympathetic nerve stimulation in vitro. Using electrophysiological recording and fluorescence imaging, BNP also reduced the depolarization evoked calcium current and intracellular calcium transient in isolated cardiac sympathetic neurons. Pharmacological manipulations suggested that the reduction in the calcium...
The prevalence of carbapenemase producing Enterobacteriaceae (CPE) has been increasing 25 worldwi... more The prevalence of carbapenemase producing Enterobacteriaceae (CPE) has been increasing 25 worldwide. bla IMP has been reported as the predominant carbapenemase-encoding gene 26 within Enterobacteriaceae in Australia. However, there is limited data currently available on 27 CPE from Queensland, Australia. A total of 58 CPE isolates were isolated between July 2009 28 and March 2014 from Queensland hospitals. The clonality of isolates was determined by rep-29 PCR Diversilab TM . The isolates were investigated for the resistance mechanisms by PCR 30 carbapenemase, ESBL, AmpC β-lactamase, aminoglycoside resistance and plasmid-mediated 31 quinolone resistance genes. The plasmid types associated with carbapenemase encoding 32 genes were characterised. The majority of the CPE were E. cloacae (n=29). The majority of 33
Background: Patients with BSIs caused by gram-negative organisms have a high rate of mortality. O... more Background: Patients with BSIs caused by gram-negative organisms have a high rate of mortality. Our objectives were to identify the predictors of mortality associated with gram-negative BSIs in ICUs. Methods: A multicenter, retrospective cohort study between 2005 and 2007 was performed, including 808 patients with BSIs due to Enterobacteriaceae. Results: 265 (32.8%) patients were identified as having BSI with onset in the ICU. The BSIs were caused by E. coli (n = 90), Klebsiella spp. (n = 107) or Enterobacter spp. (n = 68). The overall 28-day mortality rate was 30.1% (80 of 265). In multivariate analysis, significant predictors of mortality were APACHE Π severity score > 25 at the time of infection (OR 10.7 [CI 4.5 - 25.7], P < 0.001) and need for vasopressor use (OR 4.2 [2.2 - 8.0], P < 0.001). In multivariate analysis of patients with the highest quartile of Apache Π scores, male sex (OR 4.82 [CI 1.15 - 20.29], P = 0.03) and vasopressor use (OR 4.07 [CI 1.1 - 15.1], P = 0...
Background: Extended-spectrum beta-lactamases (ESBLs) commonly found in Enterobacteriaceae have b... more Background: Extended-spectrum beta-lactamases (ESBLs) commonly found in Enterobacteriaceae have been of TEM and SHV types in the United States. However, detection of CTX-M-type ESBLs is increasingly reported. Methods: Bacteremic isolates of Escherichia coli and Klebsiella pneumoniae were collected at three tertiary medical centers in Northeastern United States (Pennsylvania, New York, and Massachusetts) between 2005 and 2007. ESBL producing isolates were identified by standard phenotypic methods and characterized by PCR and sequencing. Results: A total of 855 bacteremic isolates were available for study. Sixty-four isolates (7.5%; 47 K. pneumoniae and 17 E. coli) produced ESBLs. The ESBL types observed in K. pneumoniae were SHV (85%), KPC (19%), and CTX-M (2%). Specific SHV types included SHV-2a, 5, 7, 12, 30 and 31. All KPC-positive isolates were from the New York site and produced either KPC-2 or 3. In E. coli, CTX-M was the most common (41%), followed by SHV (35%) and TEM (6%). C...
Antimicrobial agents and chemotherapy, Jan 13, 2015
The novel extended-spectrum β-lactamase (ESBL), PME-1, was first described in 2010 from a Pseudom... more The novel extended-spectrum β-lactamase (ESBL), PME-1, was first described in 2010 from a Pseudomonas aeruginosa strain obtained from multiple clinical specimens from a single patient admitted to University of Pittsburgh Medical Center in 2008.….
Pulse modulated fluorescence has increasingly been used as an ecological tool to examine changes ... more Pulse modulated fluorescence has increasingly been used as an ecological tool to examine changes in the vertical distribution of microphytobenthic cells within the upper layers of estuarine sediments (most often using the minimum fluorescence yield F o ) as well as to indicate the health of the community (using the maximum PS II quantum efficiency F v /F m ). However, the practicalities of in situ measurements, often dictates that short dark adaptation periods must be used (∼15 min). The use of far-red light as an alternative to dark adaptation was investigated in natural migratory microphytobenthic biofilms and artificial non-migratory biofilms. Prolonged periods of darkness (∼24 h) were not adequate to achieve 'true' measurements of F o and F v /F m , which require complete oxidation of Q A and full reversal of non-photochemical quenching (NPQ). In some instances, stable values were only achieved using far-red light. Prolonged exposure to dark/far-red light led to a downwards migration of cells in natural assemblages, as seen by a reduction in both F o and the maximum fluorescence yield (F m ). In non-migratory biofilms, F m increased in the dark and far-red treatments, indicating a reversal of NPQ, whereas F o decreased in far-red light but increased in the dark. It is suggested that far-red light and darkness differentially affected the balance between NPQ reversal and Q A oxidation that lead to the measured F o yield. The use of far-red light as an alternative to dark adaptation is discussed and the implications of short (e.g., 15 min) dark adaptation times used in situ are discussed with reference to the vertical migration of cells within sediment biofilms.
Pulse amplitude modulated (PAM) fluorescence has been used as a proxy of microphytobenthic biomas... more Pulse amplitude modulated (PAM) fluorescence has been used as a proxy of microphytobenthic biomass after a dark adaptation period of 15 min to stabilise the minimum fluorescence yield (F o 15 ). This methodology was investigated for in situ migratory and ex situ engineered non-migratory biofilms, comparing dark adaptation to low (5% ambient) and far-red light treatments over different emersion periods. Far-red and low light reduced potential errors resulting from light history effects, by reversal of non-photochemical quenching after 5 min of treatment, compared to over 10 min required by conventional dark adaptation. An in situ decline of minimum fluorescence yield over 15 min was observed during the dark adaptation for migratory biofilms, but was not observed in the nonmigratory biofilms indicating that the major cause of decline was downward vertical migration of cells into the sediment. This pattern occurred in far-red light after 10 min, but not for the low light treatment, indicating that low light maintained the biomass at the 15 PSII photochemical efficiency after a saturating pulse, after 10 s or 5, 10 and 15 min of treatment, respectively NPQ Non-photochemical fluorescence quenching PPFD
... SU Gerbersdorf (*) Institute of Hydraulic Engineering, University of Stuttgart, Pfaffenwaldri... more ... SU Gerbersdorf (*) Institute of Hydraulic Engineering, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany e-mail: Sabine.Gerbersdorf@iws.uni-stuttgart.de J Soils Sediments (2009) 9:640652 DOI 10.1007/s11368-009-0142-5 Page 2. Keywords CSM . ...
Neuronal nicotinic acetylcholine receptors (nAChRs) are a family of ligand gated ion channels whi... more Neuronal nicotinic acetylcholine receptors (nAChRs) are a family of ligand gated ion channels which are widely distributed in the human brain. Multiple subtypes of these receptors exist, each with individual pharmacological and functional profiles. They mediate the effects of nicotine, a widely used drug of abuse, are involved in a number of physiological and behavioural processes and are additionally implicated in a number of pathological conditions such as Alzheimer's disease, Parkinson's disease and schizophrenia. The nAChRs have a pentameric structure composed of five membrane spanning subunits, of which nine different types have thus far been identified and cloned. The multiple subunits identified provide the basis for the heterogeneity of structure and function observed in the nAChR subtypes and are responsible for the individual characteristics of each. A substantial amount of information on human nAChR structure and function has come from studies on neuroblastoma cel...
Page 1. Eur. J. Phycol. (2002), 37: 485492. # 2002 British Phycological Society DOI: 10.1017\S09... more Page 1. Eur. J. Phycol. (2002), 37: 485492. # 2002 British Phycological Society DOI: 10.1017\S0967026202003888 Printed in the United Kingdom 485 Determination of microphytobenthic biomass using pulse-amplitude modulated minimum fluorescence ...
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