Background/Aims: High morbidity and mortality rates in cirrhotic patients undergoing resections f... more Background/Aims: High morbidity and mortality rates in cirrhotic patients undergoing resections for hepatocellular malignancies underscore the need for identifying a therapy that will decrease fibrosis or enhance hepatic regenerative activity in the perioperative period. Thus, in the present study, 104 carbon tetrachloride-induced cirrhotic rats received either saline (untreated cirrhotic controls) or one of the following agents that have been reported
Aminoacyl-tRNA synthetases are multidomain enzymes that catalyze covalent attachment of amino aci... more Aminoacyl-tRNA synthetases are multidomain enzymes that catalyze covalent attachment of amino acids to their cognate tRNA. Cross-talk between functional domains is a prerequisite for this process. In this study, we investigate the molecular mechanism of site-to-site communication in Escherichia coli prolyl-tRNA synthetase (Ec ProRS). Earlier studies have demonstrated that evolutionarily conserved and/or co-evolved residues that are engaged in correlated motion are critical for the propagation of functional conformational changes from one site to another in modular proteins. Here, molecular simulation and bioinformatics-based analysis were performed to identify dynamically coupled and evolutionarily constrained residues that form contiguous pathways of residue-residue interactions between the aminoacylation and editing domains of Ec ProRS. The results of this study suggest that multiple pathways exist between these two domains to maintain the dynamic coupling essential for enzyme fun...
Human embryonic stem cells (hESCs) were used as a model system of human pancreas development to s... more Human embryonic stem cells (hESCs) were used as a model system of human pancreas development to study characteristics of the polyhormonal cells that arise during fetal pancreas development. HESCs were differentiated into fetal-like pancreatic cells in vitro using a 33-day, 7-stage protocol. Cultures were ~90-95% PDX1-positive by day (d) 11 and 70-75% NKX6.1-positive by d17. Polyhormonal cells were scattered at d17, but developed into islet-like clusters that expressed key transcription factors by d33. Human C-peptide and glucagon secretion were first detected at d17 and increased thereafter in parallel with INS and GCG transcript levels. HESC-derived cells were responsive to KCl and arginine, but not glucose in perifusion studies. Compared to adult human islets, hESC-derived cells expressed ~10-fold higher levels of glucose transporter 1 (GLUT1) mRNA, but similar levels of glucokinase (GCK). In situ hybridization confirmed the presence of GLUT1 transcript within endocrine cells. How...
The purpose of this study was to measure the extent to which geographic residency status and the ... more The purpose of this study was to measure the extent to which geographic residency status and the social environment are associated with disease stage at diagnosis, receipt of treatment, and five-year survival for patients diagnosed with non-small cell lung cancer (NSCLC). This study was a retrospective cohort study of the Georgia Comprehensive Cancer Registry (GCCR) for incident cases of NSCLC diagnosed in the state. Multilevel logistic models were employed for five outcome variables: unstaged and late stage disease at diagnosis; receipt of treatment (surgery, chemotherapy, and radiation); and survival following diagnosis. The social and geographical variables of interest were census tract (CT) poverty level, CT-level educational attainment, and CT-level geographic residency status. Compared to urban residents, rural and suburban residents had increased odds of unstaged disease (suburban OR=1.23, 95% CI: 1.11-1.37; rural OR=1.63, 95% CI: 1.45-1.83). In this study, rural participants...
These data suggest that insulin secretion in WSB mice is blunted specifically in vivo, either due... more These data suggest that insulin secretion in WSB mice is blunted specifically in vivo, either due to a reduced insulin requirement and/or due to factors that are absent or destroyed in vitro. These studies also highlight the role of post-natal growth in determining adult β-cell mass. Mice are important animal models for the study of metabolic physiology and the genetics of complex traits. Wild-derived inbred mouse strains, such as WSB/EiJ (WSB), are unrelated to the commonly studied mouse strains and are valuable tools to identify novel genes that modify disease risk. We have previously shown that in contrast to C57BL/6J (B6) mice, WSB mice fed a high fat diet do not develop hyperinsulinemia or insulin resistance, and had nearly undetectable insulin secretion in response to an intraperitoneal glucose challenge. As hyperinsulinemia may drive obesity and insulin resistance, we examined whether defects in β-cell mass or function could contribute to the low insulin levels in WSB mice. I...
To examine the effects of dorsal angulation deformities of the distal radius with and without tri... more To examine the effects of dorsal angulation deformities of the distal radius with and without triangular fibrocartilage complex (TFCC) rupture on the 3-dimensional kinematics of the distal radioulnar joint (DRUJ) during simulated active motion. Nine fresh-frozen cadaveric specimens were tested in a forearm simulator that produced active forearm rotation. Dorsal angulation deformities of the distal radius with 10°, 20°, and 30° angulation were created. Changes in the position of the ulna relative to the radius at the DRUJ as a consequence of each dorsal angulation deformity were quantified during simulated active supination in terms of volar, ulnar, and distal displacement of the ulna. Testing was performed initially with the TFCC intact and repeated after complete sectioning of the TFCC at its ulnar insertion. Increasing dorsal angulation deformities of the distal radius significantly increased volar, ulnar, and distal displacement of the ulna when the TFCC was intact. Sectioning of...
Prevalence of avian influenza virus (AIV) antibodies in the western Atlantic subspecies of Red Kn... more Prevalence of avian influenza virus (AIV) antibodies in the western Atlantic subspecies of Red Knot (Calidris canutus rufa) is among the highest for any shorebird. To assess whether the frequency of detection of AIV antibodies is high for the species in general or restricted only to C. c. rufa, we sampled the northeastern Pacific Coast subspecies of Red Knot (Calidris canutus roselaari) breeding in northwestern Alaska. Antibodies were detected in 90% of adults and none of the chicks sampled. Viral shedding was not detected in adults or chicks. These results suggest a predisposition of Red Knots to AIV infection. High antibody titers to subtypes H3 and H4 were detected, whereas low to intermediate antibody levels were found for subtypes H10 and H11. These four subtypes have previously been detected in shorebirds at Delaware Bay (at the border of New Jersey and Delaware) and in waterfowl along the Pacific Coast of North America.
The purpose of this study was to compare the fracture resistance to cyclic fatigue of ProTaper Ne... more The purpose of this study was to compare the fracture resistance to cyclic fatigue of ProTaper Next (PTN; Dentsply Tulsa Dental Specialties, Tulsa, OK), ProTaper Universal (PTU, Dentsply Tulsa Dental Specialties), and Vortex Blue (VB, Dentsply Tulsa Dental Specialties) rotary instruments. Twenty instruments each of PTN X1-X5, PTU S1-F5, and VB 20/04-50/04 were rotated until fracture in a simulated canal of 90° and a 5-mm radius using a custom-made testing platform. The number of cycles to fracture (NCF) was calculated. Weibull analysis was used to predict the maximum number of cycles when 99% of the instrument samples survive. VB 20/04-30/04 had significantly higher NCF than PTU S1-F5 and PTN X1-X5. VB 35/04-45/04 had significantly higher NCF than PTU S2-F5 and PTN X2-X5. PTN X1 had higher NCF than PTU S1-F5. PTN X2 had higher NCF than PTU F2-F5. The Weibull distribution predicted the highest number of cycles at which 99% of instruments survive to be 766 cycles for VB 25/04 and the ...
Using 1996 data on defendants accused of felony offenses derived from a district court in a Midwe... more Using 1996 data on defendants accused of felony offenses derived from a district court in a Midwestern jurisdiction, the authors employ bivariate and multivariate analyses to examine for significant differences between Hispanics and other racial and ethnic groups in the dependent variable, bail amount set by judge. To predict differences in the bail amount set by judges for Hispanic and
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.], 2014
Distal humeral hemiarthroplasty is a treatment option for distal humeral fractures, nonunions, an... more Distal humeral hemiarthroplasty is a treatment option for distal humeral fractures, nonunions, and avascular necrosis. The biomechanical effects, however, have not been reported. The purpose of this in vitro study was to quantify the effects of hemiarthroplasty and implant size on elbow joint kinematics. Eight fresh-frozen cadaveric arms were mounted in an in vitro motion simulator. An electromagnetic tracking system quantified elbow kinematics. A custom distal humeral stem was implanted by use of navigation, and 3 humeral articular spools were evaluated: optimally sized, undersized, and oversized. Statistical analysis was performed with repeated-measures analysis of variance. Distal humeral hemiarthroplasty altered elbow kinematics, regardless of implant size. In the valgus position, the optimally sized implant resulted in a mean increase in valgus angulation of 3° ± 1° (P = .003) as compared with the osteotomy control. In the varus position, the optimal and undersized implants bot...
North American Journal of Fisheries Management, 2010
Walleyes Sander vitreus are stocked into Owasco Lake, New York, to provide a sport fishery, but t... more Walleyes Sander vitreus are stocked into Owasco Lake, New York, to provide a sport fishery, but the population must be sustained by annual hatchery supplementation despite the presence of appropriate habitat. Therefore, we evaluated walleye spawning success in Dutch Hollow Brook, a tributary of Owasco Lake, to determine whether early survival limited recruitment. Spawning success during spring 2006 and 2007
Several mechanistic hypotheses have been proposed for how carotenoid pigmentation of integumentar... more Several mechanistic hypotheses have been proposed for how carotenoid pigmentation of integumentary structures can serve as an honest signal of individual quality. These hypotheses are founded on proposed links between carotenoids, immuno responsiveness, and oxidative stress, but an absence of biochemical information on the oxidative pathways of carotenoids has limited the sophistication of such hypotheses. Based on published evidence, we propose that the oxidation of carotenoids for the purpose of ornamentation in birds and reptiles is coupled to the inner mitochondria membrane. We predict that several carotenoid oxidation reactions yielding ornamental pigments occur on the inner mitochondrial membrane. Three of these reactions are proposed to occur within the ubiquinone biosynthesis cluster known as the Coq cluster consisting of approximately a dozen Coq members, tightly integrated and intimately associated with Complex I and III of the electron transport system. Ubiquinone and hig...
Journal of biochemical and biophysical methods, Jan 31, 2004
Antibody adsorption to solid surfaces creates a number of constraints that may interfere with epi... more Antibody adsorption to solid surfaces creates a number of constraints that may interfere with epitope recognition and ligand-antibody interaction. By optimizing the conditions of adsorption, one may minimize these constraints. We have studied several factors that affect the antibody adsorption using atomic force microscopy (AFM) as a readout mechanism. AFM provides a highly sensitive, label-free method for detecting and analyzing molecular interactions. In this report, AFM was used to study antibody properties, the efficiency of particle capture and ligand-antibody interaction using anti-bacteriophage fd antibodies in a solid phase assay format. The capture efficiencies of anti-fd preparations adsorbed onto gold surfaces under various conditions including pH and antibody concentration were determined and compared. The relative sensitivities of each antibody for the capture of phage fd as a function of applied phage concentrations was evaluated. The collective data indicates that AFM...
Goldfish somatotropes contain multiple functionally distinct classes of non-mitochondrial intrace... more Goldfish somatotropes contain multiple functionally distinct classes of non-mitochondrial intracellular Ca(2+) stores. In this study, we investigated the role of mitochondrial Ca(2+) handling in the control of hormone secretion. Inhibition of mitochondrial Ca(2+) uptake with 10 microM ruthenium red (RR) and 10 microM carbonyl cyanide m-chlorophenylhydrazone (CCCP) caused a small and reversible increase in cytosolic [Ca(2+)]. Despite relatively modest global Ca(2+) signals, RR and CCCP stimulated robust GH secretion under basal culture conditions. CCCP-stimulated hormone release was abolished in cells pre-incubated with 50 microM BAPTA-AM, suggesting that elevations in cytosolic [Ca(2+)] mediate this release of GH. Both caffeine-sensitive intracellular Ca(2+) stores and L-type Ca(2+) channels can be the source of the Ca(2+) buffered by mitochondria in somatotropes. The stimulatory effect of RR on caffeine-stimulated GH release was enhanced dramatically in the presence of ryanodine, p...
Vaccination of healthcare workers (HCWs) against influenza is an important component of infection... more Vaccination of healthcare workers (HCWs) against influenza is an important component of infection control in healthcare settings but HCW vaccination rates remain low. Here we review current and emerging strategies for influenza vaccination of HCWs. Professional organizations have recommended annual influenza vaccination for HCWs since 1984, but HCW vaccination rates have improved minimally. Recent studies indicate that comprehensive influenza vaccination programs have failed to achieve adequate influenza vaccination rates for HCWs in spite of allocating substantial resources to HCW vaccination programs. Mandatory HCW influenza vaccination programs have been introduced and clearly outperform traditional comprehensive vaccination programs. Some argue that mandatory vaccination programs infringe on HCW autonomy, and introduction of mandatory vaccination programs can be controversial. Public reporting of institutional HCW influenza vaccination rates is another strategy to achieve high v...
American journal of physiology. Endocrinology and metabolism, 2002
Ca(+) stores may regulate multiple components of the secretory pathway. We examined the roles of ... more Ca(+) stores may regulate multiple components of the secretory pathway. We examined the roles of biochemically independent intracellular Ca(2+) stores on acute and long-term growth hormone (GH) release, storage, and mRNA levels in goldfish somatotropes. Thapsigargin-evoked intracellular Ca(2+) concentration ([Ca(2+)](i)) signal amplitude was similar to the Ca(2+)-mobilizing agonist gonadotropin-releasing hormone, but thapsigargin (2 microM) did not acutely increase GH release, suggesting uncoupling between [Ca(2+)](i) and exocytosis. However, 2 microM thapsigargin affected long-term secretory function. Thapsigargin-treated cells displayed a steady secretion of GH (2, 12, and 24 h), which decreased GH content (12 and 24 h), but not GH mRNA/production (24 h). In contrast to the results with thapsigargin, activating the ryanodine (Ry) receptor (RyR) with 1 nM Ry transiently increased GH release (2 h). Prolonged activation of RyR (24 h) reduced GH release, contents and apparent producti...
Journal of the American Chemical Society, Jan 19, 2002
The antitumor agent (-)-rhazinilam was synthesized in three major steps, namely the pyrrole synth... more The antitumor agent (-)-rhazinilam was synthesized in three major steps, namely the pyrrole synthesis, selective C[bond]H bond activation, and direct macrolactam formation. The key step involved asymmetric C[bond]H bond functionalization (dehydrogenation) of the diethyl group segment in intermediate 6. This was achieved by the attachment of chiral platinum complexes to the proximal nitrogen atom. A high degree of selectivity (60-75% ee) was achieved via the use of oxazolinyl ketone chiral auxiliaries.
In vivo gene manipulation is a cornerstone approach in modern physiology. Cre-Lox technology has ... more In vivo gene manipulation is a cornerstone approach in modern physiology. Cre-Lox technology has been extensively used to delete genes and activate reporters in pancreatic β-cells, bringing new insight into the pathophysiology of diabetes. In all cases, it is important to understand the expression domain of the specific reporter-Cre combination in order to correctly interpret the data. In the case of targeted genes with significant expression and function in the brain, the use of Ins2 promoter driven Cre, commonly known as RIP-Cre, has been shown to confound data interpretation when appropriate controls are not present. The recent article from the Philipson group in Islets provides an important characterization of a new Cre-deleter model, referred to as MIP1-CreER, which employs the mouse Ins1 promoter. This Ins1 promoter, recapitulating the expression pattern of the endogenous Ins1 gene, does not drive significant transgene expression in the brain and therefore is highly specific f...
Determining the costs of sexual ornaments is complicated by the fact that ornaments are often int... more Determining the costs of sexual ornaments is complicated by the fact that ornaments are often integrated with other, non-sexual traits, making it difficult to dissect the effect of ornaments independent of other aspects of the phenotype. Hybridization can produce reduced phenotypic integration, allowing one to evaluate performance across a broad range of multivariate trait values. Here we assess the relationship between morphology and performance in the swordtails Xiphophorus malinche and X. birchmanni, two naturally-hybridizing fish species that differ extensively in non-sexual as well as sexual traits. We took advantage of novel trait variation in hybrids to determine if sexual ornaments incur a cost in terms of locomotor ability. For both fast-start and endurance swimming, hybrids performed at least as well as the two parental species. The sexually-dimorphic sword did not impair swimming performance per se. Rather, the sword negatively affected performance only when paired with a...
Background/Aims: High morbidity and mortality rates in cirrhotic patients undergoing resections f... more Background/Aims: High morbidity and mortality rates in cirrhotic patients undergoing resections for hepatocellular malignancies underscore the need for identifying a therapy that will decrease fibrosis or enhance hepatic regenerative activity in the perioperative period. Thus, in the present study, 104 carbon tetrachloride-induced cirrhotic rats received either saline (untreated cirrhotic controls) or one of the following agents that have been reported
Aminoacyl-tRNA synthetases are multidomain enzymes that catalyze covalent attachment of amino aci... more Aminoacyl-tRNA synthetases are multidomain enzymes that catalyze covalent attachment of amino acids to their cognate tRNA. Cross-talk between functional domains is a prerequisite for this process. In this study, we investigate the molecular mechanism of site-to-site communication in Escherichia coli prolyl-tRNA synthetase (Ec ProRS). Earlier studies have demonstrated that evolutionarily conserved and/or co-evolved residues that are engaged in correlated motion are critical for the propagation of functional conformational changes from one site to another in modular proteins. Here, molecular simulation and bioinformatics-based analysis were performed to identify dynamically coupled and evolutionarily constrained residues that form contiguous pathways of residue-residue interactions between the aminoacylation and editing domains of Ec ProRS. The results of this study suggest that multiple pathways exist between these two domains to maintain the dynamic coupling essential for enzyme fun...
Human embryonic stem cells (hESCs) were used as a model system of human pancreas development to s... more Human embryonic stem cells (hESCs) were used as a model system of human pancreas development to study characteristics of the polyhormonal cells that arise during fetal pancreas development. HESCs were differentiated into fetal-like pancreatic cells in vitro using a 33-day, 7-stage protocol. Cultures were ~90-95% PDX1-positive by day (d) 11 and 70-75% NKX6.1-positive by d17. Polyhormonal cells were scattered at d17, but developed into islet-like clusters that expressed key transcription factors by d33. Human C-peptide and glucagon secretion were first detected at d17 and increased thereafter in parallel with INS and GCG transcript levels. HESC-derived cells were responsive to KCl and arginine, but not glucose in perifusion studies. Compared to adult human islets, hESC-derived cells expressed ~10-fold higher levels of glucose transporter 1 (GLUT1) mRNA, but similar levels of glucokinase (GCK). In situ hybridization confirmed the presence of GLUT1 transcript within endocrine cells. How...
The purpose of this study was to measure the extent to which geographic residency status and the ... more The purpose of this study was to measure the extent to which geographic residency status and the social environment are associated with disease stage at diagnosis, receipt of treatment, and five-year survival for patients diagnosed with non-small cell lung cancer (NSCLC). This study was a retrospective cohort study of the Georgia Comprehensive Cancer Registry (GCCR) for incident cases of NSCLC diagnosed in the state. Multilevel logistic models were employed for five outcome variables: unstaged and late stage disease at diagnosis; receipt of treatment (surgery, chemotherapy, and radiation); and survival following diagnosis. The social and geographical variables of interest were census tract (CT) poverty level, CT-level educational attainment, and CT-level geographic residency status. Compared to urban residents, rural and suburban residents had increased odds of unstaged disease (suburban OR=1.23, 95% CI: 1.11-1.37; rural OR=1.63, 95% CI: 1.45-1.83). In this study, rural participants...
These data suggest that insulin secretion in WSB mice is blunted specifically in vivo, either due... more These data suggest that insulin secretion in WSB mice is blunted specifically in vivo, either due to a reduced insulin requirement and/or due to factors that are absent or destroyed in vitro. These studies also highlight the role of post-natal growth in determining adult β-cell mass. Mice are important animal models for the study of metabolic physiology and the genetics of complex traits. Wild-derived inbred mouse strains, such as WSB/EiJ (WSB), are unrelated to the commonly studied mouse strains and are valuable tools to identify novel genes that modify disease risk. We have previously shown that in contrast to C57BL/6J (B6) mice, WSB mice fed a high fat diet do not develop hyperinsulinemia or insulin resistance, and had nearly undetectable insulin secretion in response to an intraperitoneal glucose challenge. As hyperinsulinemia may drive obesity and insulin resistance, we examined whether defects in β-cell mass or function could contribute to the low insulin levels in WSB mice. I...
To examine the effects of dorsal angulation deformities of the distal radius with and without tri... more To examine the effects of dorsal angulation deformities of the distal radius with and without triangular fibrocartilage complex (TFCC) rupture on the 3-dimensional kinematics of the distal radioulnar joint (DRUJ) during simulated active motion. Nine fresh-frozen cadaveric specimens were tested in a forearm simulator that produced active forearm rotation. Dorsal angulation deformities of the distal radius with 10°, 20°, and 30° angulation were created. Changes in the position of the ulna relative to the radius at the DRUJ as a consequence of each dorsal angulation deformity were quantified during simulated active supination in terms of volar, ulnar, and distal displacement of the ulna. Testing was performed initially with the TFCC intact and repeated after complete sectioning of the TFCC at its ulnar insertion. Increasing dorsal angulation deformities of the distal radius significantly increased volar, ulnar, and distal displacement of the ulna when the TFCC was intact. Sectioning of...
Prevalence of avian influenza virus (AIV) antibodies in the western Atlantic subspecies of Red Kn... more Prevalence of avian influenza virus (AIV) antibodies in the western Atlantic subspecies of Red Knot (Calidris canutus rufa) is among the highest for any shorebird. To assess whether the frequency of detection of AIV antibodies is high for the species in general or restricted only to C. c. rufa, we sampled the northeastern Pacific Coast subspecies of Red Knot (Calidris canutus roselaari) breeding in northwestern Alaska. Antibodies were detected in 90% of adults and none of the chicks sampled. Viral shedding was not detected in adults or chicks. These results suggest a predisposition of Red Knots to AIV infection. High antibody titers to subtypes H3 and H4 were detected, whereas low to intermediate antibody levels were found for subtypes H10 and H11. These four subtypes have previously been detected in shorebirds at Delaware Bay (at the border of New Jersey and Delaware) and in waterfowl along the Pacific Coast of North America.
The purpose of this study was to compare the fracture resistance to cyclic fatigue of ProTaper Ne... more The purpose of this study was to compare the fracture resistance to cyclic fatigue of ProTaper Next (PTN; Dentsply Tulsa Dental Specialties, Tulsa, OK), ProTaper Universal (PTU, Dentsply Tulsa Dental Specialties), and Vortex Blue (VB, Dentsply Tulsa Dental Specialties) rotary instruments. Twenty instruments each of PTN X1-X5, PTU S1-F5, and VB 20/04-50/04 were rotated until fracture in a simulated canal of 90° and a 5-mm radius using a custom-made testing platform. The number of cycles to fracture (NCF) was calculated. Weibull analysis was used to predict the maximum number of cycles when 99% of the instrument samples survive. VB 20/04-30/04 had significantly higher NCF than PTU S1-F5 and PTN X1-X5. VB 35/04-45/04 had significantly higher NCF than PTU S2-F5 and PTN X2-X5. PTN X1 had higher NCF than PTU S1-F5. PTN X2 had higher NCF than PTU F2-F5. The Weibull distribution predicted the highest number of cycles at which 99% of instruments survive to be 766 cycles for VB 25/04 and the ...
Using 1996 data on defendants accused of felony offenses derived from a district court in a Midwe... more Using 1996 data on defendants accused of felony offenses derived from a district court in a Midwestern jurisdiction, the authors employ bivariate and multivariate analyses to examine for significant differences between Hispanics and other racial and ethnic groups in the dependent variable, bail amount set by judge. To predict differences in the bail amount set by judges for Hispanic and
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.], 2014
Distal humeral hemiarthroplasty is a treatment option for distal humeral fractures, nonunions, an... more Distal humeral hemiarthroplasty is a treatment option for distal humeral fractures, nonunions, and avascular necrosis. The biomechanical effects, however, have not been reported. The purpose of this in vitro study was to quantify the effects of hemiarthroplasty and implant size on elbow joint kinematics. Eight fresh-frozen cadaveric arms were mounted in an in vitro motion simulator. An electromagnetic tracking system quantified elbow kinematics. A custom distal humeral stem was implanted by use of navigation, and 3 humeral articular spools were evaluated: optimally sized, undersized, and oversized. Statistical analysis was performed with repeated-measures analysis of variance. Distal humeral hemiarthroplasty altered elbow kinematics, regardless of implant size. In the valgus position, the optimally sized implant resulted in a mean increase in valgus angulation of 3° ± 1° (P = .003) as compared with the osteotomy control. In the varus position, the optimal and undersized implants bot...
North American Journal of Fisheries Management, 2010
Walleyes Sander vitreus are stocked into Owasco Lake, New York, to provide a sport fishery, but t... more Walleyes Sander vitreus are stocked into Owasco Lake, New York, to provide a sport fishery, but the population must be sustained by annual hatchery supplementation despite the presence of appropriate habitat. Therefore, we evaluated walleye spawning success in Dutch Hollow Brook, a tributary of Owasco Lake, to determine whether early survival limited recruitment. Spawning success during spring 2006 and 2007
Several mechanistic hypotheses have been proposed for how carotenoid pigmentation of integumentar... more Several mechanistic hypotheses have been proposed for how carotenoid pigmentation of integumentary structures can serve as an honest signal of individual quality. These hypotheses are founded on proposed links between carotenoids, immuno responsiveness, and oxidative stress, but an absence of biochemical information on the oxidative pathways of carotenoids has limited the sophistication of such hypotheses. Based on published evidence, we propose that the oxidation of carotenoids for the purpose of ornamentation in birds and reptiles is coupled to the inner mitochondria membrane. We predict that several carotenoid oxidation reactions yielding ornamental pigments occur on the inner mitochondrial membrane. Three of these reactions are proposed to occur within the ubiquinone biosynthesis cluster known as the Coq cluster consisting of approximately a dozen Coq members, tightly integrated and intimately associated with Complex I and III of the electron transport system. Ubiquinone and hig...
Journal of biochemical and biophysical methods, Jan 31, 2004
Antibody adsorption to solid surfaces creates a number of constraints that may interfere with epi... more Antibody adsorption to solid surfaces creates a number of constraints that may interfere with epitope recognition and ligand-antibody interaction. By optimizing the conditions of adsorption, one may minimize these constraints. We have studied several factors that affect the antibody adsorption using atomic force microscopy (AFM) as a readout mechanism. AFM provides a highly sensitive, label-free method for detecting and analyzing molecular interactions. In this report, AFM was used to study antibody properties, the efficiency of particle capture and ligand-antibody interaction using anti-bacteriophage fd antibodies in a solid phase assay format. The capture efficiencies of anti-fd preparations adsorbed onto gold surfaces under various conditions including pH and antibody concentration were determined and compared. The relative sensitivities of each antibody for the capture of phage fd as a function of applied phage concentrations was evaluated. The collective data indicates that AFM...
Goldfish somatotropes contain multiple functionally distinct classes of non-mitochondrial intrace... more Goldfish somatotropes contain multiple functionally distinct classes of non-mitochondrial intracellular Ca(2+) stores. In this study, we investigated the role of mitochondrial Ca(2+) handling in the control of hormone secretion. Inhibition of mitochondrial Ca(2+) uptake with 10 microM ruthenium red (RR) and 10 microM carbonyl cyanide m-chlorophenylhydrazone (CCCP) caused a small and reversible increase in cytosolic [Ca(2+)]. Despite relatively modest global Ca(2+) signals, RR and CCCP stimulated robust GH secretion under basal culture conditions. CCCP-stimulated hormone release was abolished in cells pre-incubated with 50 microM BAPTA-AM, suggesting that elevations in cytosolic [Ca(2+)] mediate this release of GH. Both caffeine-sensitive intracellular Ca(2+) stores and L-type Ca(2+) channels can be the source of the Ca(2+) buffered by mitochondria in somatotropes. The stimulatory effect of RR on caffeine-stimulated GH release was enhanced dramatically in the presence of ryanodine, p...
Vaccination of healthcare workers (HCWs) against influenza is an important component of infection... more Vaccination of healthcare workers (HCWs) against influenza is an important component of infection control in healthcare settings but HCW vaccination rates remain low. Here we review current and emerging strategies for influenza vaccination of HCWs. Professional organizations have recommended annual influenza vaccination for HCWs since 1984, but HCW vaccination rates have improved minimally. Recent studies indicate that comprehensive influenza vaccination programs have failed to achieve adequate influenza vaccination rates for HCWs in spite of allocating substantial resources to HCW vaccination programs. Mandatory HCW influenza vaccination programs have been introduced and clearly outperform traditional comprehensive vaccination programs. Some argue that mandatory vaccination programs infringe on HCW autonomy, and introduction of mandatory vaccination programs can be controversial. Public reporting of institutional HCW influenza vaccination rates is another strategy to achieve high v...
American journal of physiology. Endocrinology and metabolism, 2002
Ca(+) stores may regulate multiple components of the secretory pathway. We examined the roles of ... more Ca(+) stores may regulate multiple components of the secretory pathway. We examined the roles of biochemically independent intracellular Ca(2+) stores on acute and long-term growth hormone (GH) release, storage, and mRNA levels in goldfish somatotropes. Thapsigargin-evoked intracellular Ca(2+) concentration ([Ca(2+)](i)) signal amplitude was similar to the Ca(2+)-mobilizing agonist gonadotropin-releasing hormone, but thapsigargin (2 microM) did not acutely increase GH release, suggesting uncoupling between [Ca(2+)](i) and exocytosis. However, 2 microM thapsigargin affected long-term secretory function. Thapsigargin-treated cells displayed a steady secretion of GH (2, 12, and 24 h), which decreased GH content (12 and 24 h), but not GH mRNA/production (24 h). In contrast to the results with thapsigargin, activating the ryanodine (Ry) receptor (RyR) with 1 nM Ry transiently increased GH release (2 h). Prolonged activation of RyR (24 h) reduced GH release, contents and apparent producti...
Journal of the American Chemical Society, Jan 19, 2002
The antitumor agent (-)-rhazinilam was synthesized in three major steps, namely the pyrrole synth... more The antitumor agent (-)-rhazinilam was synthesized in three major steps, namely the pyrrole synthesis, selective C[bond]H bond activation, and direct macrolactam formation. The key step involved asymmetric C[bond]H bond functionalization (dehydrogenation) of the diethyl group segment in intermediate 6. This was achieved by the attachment of chiral platinum complexes to the proximal nitrogen atom. A high degree of selectivity (60-75% ee) was achieved via the use of oxazolinyl ketone chiral auxiliaries.
In vivo gene manipulation is a cornerstone approach in modern physiology. Cre-Lox technology has ... more In vivo gene manipulation is a cornerstone approach in modern physiology. Cre-Lox technology has been extensively used to delete genes and activate reporters in pancreatic β-cells, bringing new insight into the pathophysiology of diabetes. In all cases, it is important to understand the expression domain of the specific reporter-Cre combination in order to correctly interpret the data. In the case of targeted genes with significant expression and function in the brain, the use of Ins2 promoter driven Cre, commonly known as RIP-Cre, has been shown to confound data interpretation when appropriate controls are not present. The recent article from the Philipson group in Islets provides an important characterization of a new Cre-deleter model, referred to as MIP1-CreER, which employs the mouse Ins1 promoter. This Ins1 promoter, recapitulating the expression pattern of the endogenous Ins1 gene, does not drive significant transgene expression in the brain and therefore is highly specific f...
Determining the costs of sexual ornaments is complicated by the fact that ornaments are often int... more Determining the costs of sexual ornaments is complicated by the fact that ornaments are often integrated with other, non-sexual traits, making it difficult to dissect the effect of ornaments independent of other aspects of the phenotype. Hybridization can produce reduced phenotypic integration, allowing one to evaluate performance across a broad range of multivariate trait values. Here we assess the relationship between morphology and performance in the swordtails Xiphophorus malinche and X. birchmanni, two naturally-hybridizing fish species that differ extensively in non-sexual as well as sexual traits. We took advantage of novel trait variation in hybrids to determine if sexual ornaments incur a cost in terms of locomotor ability. For both fast-start and endurance swimming, hybrids performed at least as well as the two parental species. The sexually-dimorphic sword did not impair swimming performance per se. Rather, the sword negatively affected performance only when paired with a...
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