TREE-ring analysis is one of the important ways for paleoclimatic reconstruction because tree-ring series of several hundred or even thousands of years are available, and can be matched orextended and accurately dated...TREE-ring analysis is one of the important ways for paleoclimatic reconstruction because tree-ring series of several hundred or even thousands of years are available, and can be matched orextended and accurately dated, and the tree rings can record changes in climate. In China,several thousand paleoclimatic series of data are obtained from the historical documents,展开更多
Elizabeth Fisher and Victor collaboratively for many years on Tybulewicz have worked the Down syndrome mouse model project. Elizabeth Fisher＇s background is in molecular genetics and mouse models, with an interest in...Elizabeth Fisher and Victor collaboratively for many years on Tybulewicz have worked the Down syndrome mouse model project. Elizabeth Fisher＇s background is in molecular genetics and mouse models, with an interest in anueploidy. Victor Tybulewicz is an immunologist whose primary interest is in signal transduction from the antigen receptors of B and T cells.展开更多
BACKGROUND There is an intimate crosstalk between cancer formation,dissemination,treatment response and the host immune system,with inducing tumour cell death the ultimate therapeutic goal for most anti-cancer treatme...BACKGROUND There is an intimate crosstalk between cancer formation,dissemination,treatment response and the host immune system,with inducing tumour cell death the ultimate therapeutic goal for most anti-cancer treatments.However,inducing a purposeful synergistic response between conventional therapies and the immune system remains evasive.The release of damage associated molecular patterns(DAMPs)is indicative of immunogenic cell death and propagation of established immune responses.However,there is a gap in the literature regarding the importance of DAMP expression in oesophageal adenocarcinoma(OAC)or by immune cells themselves.AIM To investigate the effects of conventional therapies on DAMP expression and to determine whether OAC is an immunogenic cancer.METHODS We investigated the levels of immunogenic cell death-associated DAMPs,calreticulin(CRT)and HMGB1 using an OAC isogenic model of radioresistance.DAMP expression was also assessed directly using ex vivo cancer patient T cells(n=10)and within tumour biopsies(n=9)both pre and post-treatment with clinically relevant chemo(radio)therapeutics.RESULTS Hypoxia in combination with nutrient deprivation significantly reduces DAMP expression by OAC cells in vitro.Significantly increased frequencies of T cell DAMP expression in OAC patients were observed following chemo-(radio)therapy,which was significantly higher in tumour tissue compared with peripheral blood.Patients with high expression of HMGB1 had a significantly better tumour regression grade(TRG 1-2)compared to low expressors.CONCLUSION In conclusion,OAC expresses an immunogenic phenotype with two distinct subgroups of high and low DAMP expressors,which correlated with tumour regression grade and lymphatic invasion.It also identifies DAMPs namely CRT and HMGB1 as potential promising biomarkers in predicting good pathological responses to conventional chemo(radio)therapies currently used in the multimodal management of locally advanced disease.展开更多
A commonly used anesthetic, isoflurane, can impair auditory function in a dose-dependent manner. However, in rats, isoflurane-induced auditory impairments have only been assessed with auditory brainstem responses; a m...A commonly used anesthetic, isoflurane, can impair auditory function in a dose-dependent manner. However, in rats, isoflurane-induced auditory impairments have only been assessed with auditory brainstem responses; a measure which is unable to distinguish if changes originate from the central or peripheral auditory system. Studies performed in other species, such as mice and guinea-pigs, suggests auditory impairment stems from disrupted OHC amplification. Despite the wide use of the rat in auditory research, these observations have yet to be replicated in the rat animal model. This study used distortion product otoacoustic emissions to assess outer hair cell function in rats that were anesthetized with either isoflurane or a ketamine/xylazine cocktail for approximately 45 min. Results indicate that isoflurane can significantly reduce DPOAE amplitudes compared to ketamine/xylazine, and that responses were more variable with isoflurane than ketamine/xylazine over the 45-min test period. Based on these observations, isoflurane should be used with caution when assessing peripheral auditory function to avoid potentially confounding effects.展开更多
BACKGROUND In the contemporary era of cancer immunotherapy,an abundance of clinical and translational studies have reported radiotherapy(RT)and immunotherapies as a viable option for immunomodulation of many cancer su...BACKGROUND In the contemporary era of cancer immunotherapy,an abundance of clinical and translational studies have reported radiotherapy(RT)and immunotherapies as a viable option for immunomodulation of many cancer subtypes,with many related clinical trials ongoing.In locally advanced disease,chemotherapy or chemoradiotherapy followed by surgical excision of the tumour remain the principal treatment strategy in oesophageal adenocarcinoma(OAC),however,the use of the host immune system to improve anti-tumour immunity is rapidly garnering increased support in the curative setting.AIM To immunophenotype OAC patients’immune checkpoint(IC)expression with and without radiation and evaluate the effects of checkpoint blockade on cell viability.METHODS In the contemporary era of cancer immunotherapy,an abundance of studies have demonstrated that combination RT and IC inhibitors(ICIs)are effective in the immunomodulation of many cancer subtypes,with many related clinical trials ongoing.Although surgical excision and elimination of tumour cells by chemotherapy or chemoradiotherapy remains the gold standard approach in OAC,the propagation of anti-tumour immune responses is rapidly garnering increased support in the curative setting.The aim of this body of work was to immunophenotype OAC patients’IC expression with and without radiation and to establish the impact of checkpoint blockade on cell viability.This study was a hybrid combination of in vitro and ex vivo models.Quantification of serum immune proteins was performed by enzyme-linked immunosorbent assay.Flow cytometry staining was performed to evaluate IC expression for in vitro OAC cell lines and ex vivo OAC biopsies.Cell viability in the presence of radiation with and without IC blockade was assessed by a cell counting kit-8 assay.RESULTS We identified that conventional dosing and hypofractionated approaches resulted in increased IC expression(PD-1,PD-L1,TIM3,TIGIT)in vitro and ex vivo in OAC.There were two distinct subcohorts with one demonstrating significant upr展开更多
Proterozoic orogens commonly host a range of hydrothermal ores that form in diverse tectonic settings at different times. However, the link between mineralization and the regional-scale tectonothermal evolution of oro...Proterozoic orogens commonly host a range of hydrothermal ores that form in diverse tectonic settings at different times. However, the link between mineralization and the regional-scale tectonothermal evolution of orogens is usually not well understood, especially in areas subject to multiple hydrothermal events.Regional-scale drivers for mineral systems vary between the different classes of hydrothermal ore, but all involve an energy source and a fluid pathway to focus mineralizing fluids into the upper crust. The Mount Olympus gold deposit in the Proterozoic Capricorn Orogen of Western Australia, was regarded as an orogenic gold deposit that formed at ca. 1738 Ma during the assembly of Proterozoic Australia. However,the trace element chemistry of the pyrite crystals closely resembles those of the Carlin deposits of Nevada,with rims that display solid solution gold accompanied by elevated As, Cu, Sb, Hg, and Tl, surrounding gold-poor cores. New SHRIMP UeP b dating of xenotime intergrown with auriferous pyrite and ore-stage alteration minerals provided a weighted mean^(207) Pb*/^(206) Pb* date of 1769 ± 5 Ma, interpreted as the age of gold mineralization. This was followed by two discrete episodes of hydrothermal alteration at 1727 ± 7 Ma and 1673 ± 8 Ma. The three ages are linked to multiple reactivation of the crustal-scale Nanjilgardy Fault during repeated episodes of intracratonic reworking. The regional-scale drivers for Carlin-like gold mineralization at Mount Olympus are related to a change in tectonic regime during the final stages of the intracratonic 1820 -1770 Ma Capricorn Orogeny. Our results suggest that substantial sized Carlin-like gold deposits can form in an intracratonic setting during regional-scale crustal reworking.展开更多
Extremity reconstruction surgery is increasingly performed rather than amputation for patients with large-segment pathologic bone loss.Debate persists as to the optimal void filler for this“limb salvage”surgery,whet...Extremity reconstruction surgery is increasingly performed rather than amputation for patients with large-segment pathologic bone loss.Debate persists as to the optimal void filler for this“limb salvage”surgery,whether metal or allograft bone.Clinicians focus on optimizing important functional gains for patients,and the risk of devastating implant infection has been thought to be similar regardless of implant material.Recent insights into infection pathophysiology are challenging this equipoise,however,with both basic science data suggesting a novel mechanism of infection of Staphylococcus aureus(the most common infecting agent)into the host lacunar–canaliculi network,and also clinical data revealing a higher rate of infection of allograft over metal.The current translational study was therefore developed to bridge the gap between these insights in a longitudinal murine model of infection of allograft bone and metal.Real-time Staphylococci infection characteristics were quantified in cortical bone vs metal,and both microarchitecture of host implant and presence of host immune response were assessed.An orders-of-magnitude higher bacterial burden was established in cortical allograft bone over both metal and cancellous bone.The establishment of immune-evading microabscesses was confirmed in both cortical allograft haversian canal and the submicron canaliculi network in an additional model of mouse femur bone infection.These study results reveal a mechanism by which Staphylococci evasion of host immunity is possible,contributing to elevated risks of infection in cortical bone.The presence of this local infection reservoir imparts massive clinical implications that may alter the current paradigm of osteomyelitis and bulk allograft infection treatment.展开更多
Lutein is a dietary carotenoid of particular nutritional interest as it is preferentially taken up by neural tissues. Often linked with beneficial effects on vision, a broader role for lutein in neuronal differentiati...Lutein is a dietary carotenoid of particular nutritional interest as it is preferentially taken up by neural tissues. Often linked with beneficial effects on vision, a broader role for lutein in neuronal differentiation has emerged recently, although the underlying mechanisms for these effects are not yet dear. The purpose of this study was to investigate the effect of lutein on neuronal differentiation and explore the associated underpinning mechanisms. We found that lutein treatment enhanced the differentiation of SH-SYSY cells, specifically increasing neuronal arborization and expression of the neuronal process filament protein microtubule-associated protein 2. This effect was mediated by the intracellular phosphoinositide-3-kinase （PI3K） signaling pathway. While PI3K activity is a known trigger of neuronal differentiation, more recently it has also been shown to modulate the metabolic state of cells. Our analysis of bioenergetics found that lutein treatment increased glucose consumption, rates of glycolysis and enhanced respiratory activity of mitochondrial complexes. Concomitantly, the generation of reactive oxygen species was increased （con- sistent with previous reports that reactive oxygen species promote neuronal differentiation）, as well as the production of the key metabolic intermediate acetyl-CoA, an essential determinant of epigenetic status in the cell. We suggest that lutein-stimulated neuronal differentiation is mediated by PI3K-dependent modulation of mitochondrial respiration and signaling, and that the consequential metabolic shifts initiate epigenetically dependent transcriptomic reprogramming in support of this morphogenesis. These obser- vations support the potential importance of micronutrients supplementation to neurogenesis, both during normal development and in regenerative repair.展开更多
One technical fishway and two innovative nature-like fishways were installed at three dams on the Acushnet River in Acushnet, Massachusetts to facilitate migration of river herring and juvenile American eels （elvers...One technical fishway and two innovative nature-like fishways were installed at three dams on the Acushnet River in Acushnet, Massachusetts to facilitate migration of river herring and juvenile American eels （elvers）. Pre-construction and post-construction monitoring of river herring and elver populations used census counting and abundance estimation, respectively. Numbers of adult river herring returning to the upstream spawning grounds during the pre-construction phase were very low; elver counts declined during the pre-construction period and served as baseline levels to determine the effectiveness of the new fishways. Post-construction monitoring of river herring and elvers indicated an increasing trend of spawning adult river herring returning to the spawning grounds, with the total count in the fourth year of post-construction representing an increase of 1,140% over baseline, pre-construction conditions. Results also show increased elver recruitment into the river as well as increased proportions of elvers accessing habitat in the upper watershed that was mostly inaccessible prior to fishway installation. The new fishways at the three dams on the river have improved diadromous fish passage, thereby increasing the probability of restoring healthy populations of river herring and American eels to the Acushnet River system.展开更多
Paraquat is a broad-spectrum herbicide known to produce lung injury via oxidative stress-mediated mechanisms. Different pharmacological strategies have been explored to reduce the formation of these reactive oxygen sp...Paraquat is a broad-spectrum herbicide known to produce lung injury via oxidative stress-mediated mechanisms. Different pharmacological strategies have been explored to reduce the formation of these reactive oxygen species and/or prevent their toxic effects in the treatment of paraquat poisoning. The present study was carried out to investigate whether the antioxidant (L-tocopherol, incorporated into liposomes and delivered directly to the lungs of rats, could protect the organ against the long-term toxic effects of paraquat.Plain liposomes (composed of dipalmitoylphosphatidylcholine, DPPC) or α-tocopherol liposomes (8 mg α-tocopherol/kg body weight) were administered intratracheally to animals 24 h prior to an intraperitoneal injection of paraquat dichloride (20 mg/kg) and rats wefe killed 0, 1, 4, 6, 8, 10, 12, 16, 19 or 24 days after paraquat treatment. Results of this study showed that lungs of animals treated with paraquat were extensively damaged,as evidenced by significant increases in lung weight and decreases in lung angiotensin converting enzyme (ACE) and alkaline phosphatase enzyme (AKP) activities. Moreover,paraquat treatme; resulted in a significant reduction in the number of neutrophils in the blood of rats with a concurrent increase in the pulmonary myeloperoxidase activity,suggestive of neutrophil infiltration in the lungs of treated animals. Pretreatment of rats with liposomes alone did not significantly alter the paraquat-induced changes of all parameters examined. On the other hand, pretreatment of rats with (t-tocopherol liposomes,24 h prior to paraquat challenge, attenuated paraquat-induced changes in ACE, AKP and myeloperoxidase activities but failed to prevent increases in lung weight. Thus, pretreatment of rats with liposome-associated α-tocopherol appears to protect the lung against some of the toxic effects of paraquat展开更多
文摘TREE-ring analysis is one of the important ways for paleoclimatic reconstruction because tree-ring series of several hundred or even thousands of years are available, and can be matched orextended and accurately dated, and the tree rings can record changes in climate. In China,several thousand paleoclimatic series of data are obtained from the historical documents,
基金the Brain Research Trust,the Wellcome Trust,the UK Medical Research Council and the AnEUploidy grant from Framework Programme 6 from the European Union Commission for funding
文摘Elizabeth Fisher and Victor collaboratively for many years on Tybulewicz have worked the Down syndrome mouse model project. Elizabeth Fisher＇s background is in molecular genetics and mouse models, with an interest in anueploidy. Victor Tybulewicz is an immunologist whose primary interest is in signal transduction from the antigen receptors of B and T cells.
文摘BACKGROUND There is an intimate crosstalk between cancer formation,dissemination,treatment response and the host immune system,with inducing tumour cell death the ultimate therapeutic goal for most anti-cancer treatments.However,inducing a purposeful synergistic response between conventional therapies and the immune system remains evasive.The release of damage associated molecular patterns(DAMPs)is indicative of immunogenic cell death and propagation of established immune responses.However,there is a gap in the literature regarding the importance of DAMP expression in oesophageal adenocarcinoma(OAC)or by immune cells themselves.AIM To investigate the effects of conventional therapies on DAMP expression and to determine whether OAC is an immunogenic cancer.METHODS We investigated the levels of immunogenic cell death-associated DAMPs,calreticulin(CRT)and HMGB1 using an OAC isogenic model of radioresistance.DAMP expression was also assessed directly using ex vivo cancer patient T cells(n=10)and within tumour biopsies(n=9)both pre and post-treatment with clinically relevant chemo(radio)therapeutics.RESULTS Hypoxia in combination with nutrient deprivation significantly reduces DAMP expression by OAC cells in vitro.Significantly increased frequencies of T cell DAMP expression in OAC patients were observed following chemo-(radio)therapy,which was significantly higher in tumour tissue compared with peripheral blood.Patients with high expression of HMGB1 had a significantly better tumour regression grade(TRG 1-2)compared to low expressors.CONCLUSION In conclusion,OAC expresses an immunogenic phenotype with two distinct subgroups of high and low DAMP expressors,which correlated with tumour regression grade and lymphatic invasion.It also identifies DAMPs namely CRT and HMGB1 as potential promising biomarkers in predicting good pathological responses to conventional chemo(radio)therapies currently used in the multimodal management of locally advanced disease.
基金Research supported in part by grants from the National Institutes of Health to AS (F31DC015933) and RS (R01DC014452)the American Academy of Audiology to ASthe China Scholarship Council (No.201606095027) to DL
文摘A commonly used anesthetic, isoflurane, can impair auditory function in a dose-dependent manner. However, in rats, isoflurane-induced auditory impairments have only been assessed with auditory brainstem responses; a measure which is unable to distinguish if changes originate from the central or peripheral auditory system. Studies performed in other species, such as mice and guinea-pigs, suggests auditory impairment stems from disrupted OHC amplification. Despite the wide use of the rat in auditory research, these observations have yet to be replicated in the rat animal model. This study used distortion product otoacoustic emissions to assess outer hair cell function in rats that were anesthetized with either isoflurane or a ketamine/xylazine cocktail for approximately 45 min. Results indicate that isoflurane can significantly reduce DPOAE amplitudes compared to ketamine/xylazine, and that responses were more variable with isoflurane than ketamine/xylazine over the 45-min test period. Based on these observations, isoflurane should be used with caution when assessing peripheral auditory function to avoid potentially confounding effects.
文摘BACKGROUND In the contemporary era of cancer immunotherapy,an abundance of clinical and translational studies have reported radiotherapy(RT)and immunotherapies as a viable option for immunomodulation of many cancer subtypes,with many related clinical trials ongoing.In locally advanced disease,chemotherapy or chemoradiotherapy followed by surgical excision of the tumour remain the principal treatment strategy in oesophageal adenocarcinoma(OAC),however,the use of the host immune system to improve anti-tumour immunity is rapidly garnering increased support in the curative setting.AIM To immunophenotype OAC patients’immune checkpoint(IC)expression with and without radiation and evaluate the effects of checkpoint blockade on cell viability.METHODS In the contemporary era of cancer immunotherapy,an abundance of studies have demonstrated that combination RT and IC inhibitors(ICIs)are effective in the immunomodulation of many cancer subtypes,with many related clinical trials ongoing.Although surgical excision and elimination of tumour cells by chemotherapy or chemoradiotherapy remains the gold standard approach in OAC,the propagation of anti-tumour immune responses is rapidly garnering increased support in the curative setting.The aim of this body of work was to immunophenotype OAC patients’IC expression with and without radiation and to establish the impact of checkpoint blockade on cell viability.This study was a hybrid combination of in vitro and ex vivo models.Quantification of serum immune proteins was performed by enzyme-linked immunosorbent assay.Flow cytometry staining was performed to evaluate IC expression for in vitro OAC cell lines and ex vivo OAC biopsies.Cell viability in the presence of radiation with and without IC blockade was assessed by a cell counting kit-8 assay.RESULTS We identified that conventional dosing and hypofractionated approaches resulted in increased IC expression(PD-1,PD-L1,TIM3,TIGIT)in vitro and ex vivo in OAC.There were two distinct subcohorts with one demonstrating significant upr
基金funded through an ARC linkage grant (LP130100922) and industry scholarship by Northern Star Resources as a part of a PhD by I. O.Fielding. S. P. the financial support of the Australian Research Council and Auscope NCRIS
文摘Proterozoic orogens commonly host a range of hydrothermal ores that form in diverse tectonic settings at different times. However, the link between mineralization and the regional-scale tectonothermal evolution of orogens is usually not well understood, especially in areas subject to multiple hydrothermal events.Regional-scale drivers for mineral systems vary between the different classes of hydrothermal ore, but all involve an energy source and a fluid pathway to focus mineralizing fluids into the upper crust. The Mount Olympus gold deposit in the Proterozoic Capricorn Orogen of Western Australia, was regarded as an orogenic gold deposit that formed at ca. 1738 Ma during the assembly of Proterozoic Australia. However,the trace element chemistry of the pyrite crystals closely resembles those of the Carlin deposits of Nevada,with rims that display solid solution gold accompanied by elevated As, Cu, Sb, Hg, and Tl, surrounding gold-poor cores. New SHRIMP UeP b dating of xenotime intergrown with auriferous pyrite and ore-stage alteration minerals provided a weighted mean^(207) Pb*/^(206) Pb* date of 1769 ± 5 Ma, interpreted as the age of gold mineralization. This was followed by two discrete episodes of hydrothermal alteration at 1727 ± 7 Ma and 1673 ± 8 Ma. The three ages are linked to multiple reactivation of the crustal-scale Nanjilgardy Fault during repeated episodes of intracratonic reworking. The regional-scale drivers for Carlin-like gold mineralization at Mount Olympus are related to a change in tectonic regime during the final stages of the intracratonic 1820 -1770 Ma Capricorn Orogeny. Our results suggest that substantial sized Carlin-like gold deposits can form in an intracratonic setting during regional-scale crustal reworking.
基金the Musculoskeletal Transplant Foundation/Musculoskeletal Tumor Society grant number 20161236.Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under the Ruth L.Kirschstein National Research Service Award Number T32AR059033 and Award Number 5K08AR069112-01.+2 种基金The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.Confocal laser scanning microscopy was performed at the CNSI Advanced Light Microscopy/Spectroscopy Shared Resource Facility at UCLA,supported with funding from NIH-NCRR shared resources grant(CJX1-443835-WS-29646)and NSF Major Research Instrumentation grant(CHE-0722519).Support for LysEGFP mice was provided by the Training Program in Pharmacology:From Bench to Bedside at the University of California,Davis,supported by Grant NIH T32 GM099608(to Leif S.Anderson).Statistical support was provided by Nicholas J.Jackson,Ph.D.MPH,and the research described was supported by NIH/National Center for Advancing Translational Science(NCATS)UCLA CTSI Grant Number UL1TR001881.
文摘Extremity reconstruction surgery is increasingly performed rather than amputation for patients with large-segment pathologic bone loss.Debate persists as to the optimal void filler for this“limb salvage”surgery,whether metal or allograft bone.Clinicians focus on optimizing important functional gains for patients,and the risk of devastating implant infection has been thought to be similar regardless of implant material.Recent insights into infection pathophysiology are challenging this equipoise,however,with both basic science data suggesting a novel mechanism of infection of Staphylococcus aureus(the most common infecting agent)into the host lacunar–canaliculi network,and also clinical data revealing a higher rate of infection of allograft over metal.The current translational study was therefore developed to bridge the gap between these insights in a longitudinal murine model of infection of allograft bone and metal.Real-time Staphylococci infection characteristics were quantified in cortical bone vs metal,and both microarchitecture of host implant and presence of host immune response were assessed.An orders-of-magnitude higher bacterial burden was established in cortical allograft bone over both metal and cancellous bone.The establishment of immune-evading microabscesses was confirmed in both cortical allograft haversian canal and the submicron canaliculi network in an additional model of mouse femur bone infection.These study results reveal a mechanism by which Staphylococci evasion of host immunity is possible,contributing to elevated risks of infection in cortical bone.The presence of this local infection reservoir imparts massive clinical implications that may alter the current paradigm of osteomyelitis and bulk allograft infection treatment.
文摘Lutein is a dietary carotenoid of particular nutritional interest as it is preferentially taken up by neural tissues. Often linked with beneficial effects on vision, a broader role for lutein in neuronal differentiation has emerged recently, although the underlying mechanisms for these effects are not yet dear. The purpose of this study was to investigate the effect of lutein on neuronal differentiation and explore the associated underpinning mechanisms. We found that lutein treatment enhanced the differentiation of SH-SYSY cells, specifically increasing neuronal arborization and expression of the neuronal process filament protein microtubule-associated protein 2. This effect was mediated by the intracellular phosphoinositide-3-kinase （PI3K） signaling pathway. While PI3K activity is a known trigger of neuronal differentiation, more recently it has also been shown to modulate the metabolic state of cells. Our analysis of bioenergetics found that lutein treatment increased glucose consumption, rates of glycolysis and enhanced respiratory activity of mitochondrial complexes. Concomitantly, the generation of reactive oxygen species was increased （con- sistent with previous reports that reactive oxygen species promote neuronal differentiation）, as well as the production of the key metabolic intermediate acetyl-CoA, an essential determinant of epigenetic status in the cell. We suggest that lutein-stimulated neuronal differentiation is mediated by PI3K-dependent modulation of mitochondrial respiration and signaling, and that the consequential metabolic shifts initiate epigenetically dependent transcriptomic reprogramming in support of this morphogenesis. These obser- vations support the potential importance of micronutrients supplementation to neurogenesis, both during normal development and in regenerative repair.
文摘One technical fishway and two innovative nature-like fishways were installed at three dams on the Acushnet River in Acushnet, Massachusetts to facilitate migration of river herring and juvenile American eels （elvers）. Pre-construction and post-construction monitoring of river herring and elver populations used census counting and abundance estimation, respectively. Numbers of adult river herring returning to the upstream spawning grounds during the pre-construction phase were very low; elver counts declined during the pre-construction period and served as baseline levels to determine the effectiveness of the new fishways. Post-construction monitoring of river herring and elvers indicated an increasing trend of spawning adult river herring returning to the spawning grounds, with the total count in the fourth year of post-construction representing an increase of 1,140% over baseline, pre-construction conditions. Results also show increased elver recruitment into the river as well as increased proportions of elvers accessing habitat in the upper watershed that was mostly inaccessible prior to fishway installation. The new fishways at the three dams on the river have improved diadromous fish passage, thereby increasing the probability of restoring healthy populations of river herring and American eels to the Acushnet River system.
文摘Paraquat is a broad-spectrum herbicide known to produce lung injury via oxidative stress-mediated mechanisms. Different pharmacological strategies have been explored to reduce the formation of these reactive oxygen species and/or prevent their toxic effects in the treatment of paraquat poisoning. The present study was carried out to investigate whether the antioxidant (L-tocopherol, incorporated into liposomes and delivered directly to the lungs of rats, could protect the organ against the long-term toxic effects of paraquat.Plain liposomes (composed of dipalmitoylphosphatidylcholine, DPPC) or α-tocopherol liposomes (8 mg α-tocopherol/kg body weight) were administered intratracheally to animals 24 h prior to an intraperitoneal injection of paraquat dichloride (20 mg/kg) and rats wefe killed 0, 1, 4, 6, 8, 10, 12, 16, 19 or 24 days after paraquat treatment. Results of this study showed that lungs of animals treated with paraquat were extensively damaged,as evidenced by significant increases in lung weight and decreases in lung angiotensin converting enzyme (ACE) and alkaline phosphatase enzyme (AKP) activities. Moreover,paraquat treatme; resulted in a significant reduction in the number of neutrophils in the blood of rats with a concurrent increase in the pulmonary myeloperoxidase activity,suggestive of neutrophil infiltration in the lungs of treated animals. Pretreatment of rats with liposomes alone did not significantly alter the paraquat-induced changes of all parameters examined. On the other hand, pretreatment of rats with (t-tocopherol liposomes,24 h prior to paraquat challenge, attenuated paraquat-induced changes in ACE, AKP and myeloperoxidase activities but failed to prevent increases in lung weight. Thus, pretreatment of rats with liposome-associated α-tocopherol appears to protect the lung against some of the toxic effects of paraquat
