Pub Date : 2009-06-01DOI: 10.1093/BIOHORIZONS/HZP016
C. Gregson
Cancer is responsible for approximately 6.7 million deaths and 10.9 million newly diagnosed cases worldwide per year. Currently, the definitive diagnosis of a tissue or cell sample is determined by molecular pathology and histochemical techniques, which assess tumour type, grade and stage. This information also allows for the diagnosis, prognosis and available treatment options to be established. In addition, immunohistochemistry (IHC) in combination with histochemistry is used to determine the surgical margin status of tumours, which can be correlated to the likelihood of recurrence. Matrix-assisted laser desorption/ionization (MALDI) imaging is a mass spectrometry profiling technique, which can be used to simultaneously identify multiple species within a tissue section. The array format of the acquisition allows for the creation of an image that is viewed in a similar way to an IHC section. MALDI imaging could potentially provide an alternative diagnostic assay that could be used to provide cancer prognosis. To assess the suitability of MALDI imaging for this application, sample preparation and MALDI imaging methodology were developed using a2u-globulin as an example protein. This protein is known to be preferably expressed in the kidneys of male rats allowing a proof-of-principle study to be performed comparing the expression levels and localization between male and female rat kidney sections. The expression of a2uglobulin was localized to the cortex region of the kidney, with the levels of a2u-globulin shown to be significantly higher in the male than the female kidney sections. These findings were validated by comparison with IHC data. The proof-of-principle study therefore demonstrated that MALDI imaging could be a potential alternative to current molecular pathology and histochemical techniques for the determination of tumour type, grade and stage as well as the determination of surgical margin status.
{"title":"Optimization of MALDI tissue imaging and correlation with immunohistochemistry in rat kidney sections","authors":"C. Gregson","doi":"10.1093/BIOHORIZONS/HZP016","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP016","url":null,"abstract":"Cancer is responsible for approximately 6.7 million deaths and 10.9 million newly diagnosed cases worldwide per year. Currently, the definitive diagnosis of a tissue or cell sample is determined by molecular pathology and histochemical techniques, which assess tumour type, grade and stage. This information also allows for the diagnosis, prognosis and available treatment options to be established. In addition, immunohistochemistry (IHC) in combination with histochemistry is used to determine the surgical margin status of tumours, which can be correlated to the likelihood of recurrence. Matrix-assisted laser desorption/ionization (MALDI) imaging is a mass spectrometry profiling technique, which can be used to simultaneously identify multiple species within a tissue section. The array format of the acquisition allows for the creation of an image that is viewed in a similar way to an IHC section. MALDI imaging could potentially provide an alternative diagnostic assay that could be used to provide cancer prognosis. To assess the suitability of MALDI imaging for this application, sample preparation and MALDI imaging methodology were developed using a2u-globulin as an example protein. This protein is known to be preferably expressed in the kidneys of male rats allowing a proof-of-principle study to be performed comparing the expression levels and localization between male and female rat kidney sections. The expression of a2uglobulin was localized to the cortex region of the kidney, with the levels of a2u-globulin shown to be significantly higher in the male than the female kidney sections. These findings were validated by comparison with IHC data. The proof-of-principle study therefore demonstrated that MALDI imaging could be a potential alternative to current molecular pathology and histochemical techniques for the determination of tumour type, grade and stage as well as the determination of surgical margin status.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"134-146"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-01DOI: 10.1093/BIOHORIZONS/HZP018
A. Keene
This study examines small mammal populations present within Barn owl corridors on Folly Farm, an Avon Wildlife Trust Reserve located near the village of Bishop Sutton in Bath and North East Somerset. Two corridors were chosen, the primary difference between the two sites being only one has undergone management (grazing). The focus of this study was the Microtus agrestis (Short-tailed field vole) population, the most frequently taken prey item by Barn owls. Apodemus sylvaticus (Wood mice) and Sorex araneus (Common shrew) populations are also discussed as they are frequently taken. Using Longworth live traps, 600 trap-nights data were collected from three sessions in November 2006, February and March 2007. Although M. agrestis was the most abundant species in both corridors, they were more prevalent in the un-grazed corridor (comprising 19 of the 31 individuals). In the corridor that had undergone management, fewer M. agrestis were captured (eight), although a higher species diversity and richness was recorded. Unusually for a grassland habitat, there were nearly as many A. sylvaticus as there were M. agrestis (seven compared with eight) in the grazed corridor. Some small mammal species not usually found in grassland habitats were captured; explanations for these seemingly anomalous results are discussed. Differences in population characteristics between the two corridors are discussed including: sex ratio, weights, seasonal variation and age structure. Pellet analysis from the nearby pair of Barn owls showed that they were preferentially hunting M. agrestis; the pellet data largely mirrored findings of the trapping data.
{"title":"Study of small mammal populations within two Barn owl corridors at Folly Farm","authors":"A. Keene","doi":"10.1093/BIOHORIZONS/HZP018","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP018","url":null,"abstract":"This study examines small mammal populations present within Barn owl corridors on Folly Farm, an Avon Wildlife Trust Reserve located near the village of Bishop Sutton in Bath and North East Somerset. Two corridors were chosen, the primary difference between the two sites being only one has undergone management (grazing). The focus of this study was the Microtus agrestis (Short-tailed field vole) population, the most frequently taken prey item by Barn owls. Apodemus sylvaticus (Wood mice) and Sorex araneus (Common shrew) populations are also discussed as they are frequently taken. Using Longworth live traps, 600 trap-nights data were collected from three sessions in November 2006, February and March 2007. Although M. agrestis was the most abundant species in both corridors, they were more prevalent in the un-grazed corridor (comprising 19 of the 31 individuals). In the corridor that had undergone management, fewer M. agrestis were captured (eight), although a higher species diversity and richness was recorded. Unusually for a grassland habitat, there were nearly as many A. sylvaticus as there were M. agrestis (seven compared with eight) in the grazed corridor. Some small mammal species not usually found in grassland habitats were captured; explanations for these seemingly anomalous results are discussed. Differences in population characteristics between the two corridors are discussed including: sex ratio, weights, seasonal variation and age structure. Pellet analysis from the nearby pair of Barn owls showed that they were preferentially hunting M. agrestis; the pellet data largely mirrored findings of the trapping data.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"155-163"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-01DOI: 10.1093/BIOHORIZONS/HZP015
Sue Bedford
After a period of decline, European Otter (Lutra lutra) populations are showing signs of recovery throughout the UK. Populations in Devon are thought to be almost fully recovered, although exact numbers are unknown; however, there are still rivers within Devon that do not appear to support Otter populations. The aim of this research was to determine the relationship between environmental condition and the presence of Otters by comparing the quality of riparian habitat of rivers with and without evidence of Otters. The research was undertaken in four rivers in Devon, the Rivers Culm, Ken, Coly and Otter: the first two being river stretches with no documented evidence of Otter populations, and the latter two having documented evidence of Otter populations. Along each of the rivers, 10 sections of 50 m were sampled. In each section, the riparian habitat quality was recorded using the Qualitat del Bosc de Riberia index. The biological water quality was determined by calculating Biological Monitoring Water Party scores, and water chemical concentrations were obtained from Environment Agency data. The riparian habitat quality and biological water quality were found to be of significantly lower quality in the river stretches that did not have evidence of Otter populations when compared with those with Otter populations. The chemical water quality was correlated to biological water quality: the quality being worse in the rivers without evidence of Otter populations. The results of this research suggest that rivers with no evidence of Otter populations are generally of worse riparian quality than those supporting Otter populations.
经过一段时间的下降，欧洲水獭(Lutra Lutra)种群在整个英国显示出复苏的迹象。德文郡的种群被认为几乎完全恢复了，尽管确切的数量尚不清楚;然而，德文郡境内仍有一些河流似乎不适合水獭的生存。本研究的目的是通过比较有水獭和没有水獭证据的河流的河岸栖息地质量，确定环境条件与水獭存在之间的关系。这项研究是在德文郡的四条河流中进行的，分别是Culm河、Ken河、Coly河和Otter河:前两条河流没有水獭种群的记录证据，后两条河流有水獭种群的记录证据。沿着每条河流，采样10段50米。在每个剖面中，使用Qualitat del Bosc de Riberia指数记录了河岸栖息地的质量。通过计算生物监测水党得分来确定生物水质，并从环境局的数据中获得水化学浓度。与有水獭种群的河段相比，没有水獭种群证据的河段的河岸生境质量和生物水质明显较低。化学水质与生物水质相关，无水獭种群的河流水质较差。这项研究的结果表明，没有水獭种群证据的河流通常比支持水獭种群的河流质量更差。
{"title":"The effects of riparian habitat quality and biological water quality on the European Otter (Lutra lutra) in Devon","authors":"Sue Bedford","doi":"10.1093/BIOHORIZONS/HZP015","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP015","url":null,"abstract":"After a period of decline, European Otter (Lutra lutra) populations are showing signs of recovery throughout the UK. Populations in Devon are thought to be almost fully recovered, although exact numbers are unknown; however, there are still rivers within Devon that do not appear to support Otter populations. The aim of this research was to determine the relationship between environmental condition and the presence of Otters by comparing the quality of riparian habitat of rivers with and without evidence of Otters. The research was undertaken in four rivers in Devon, the Rivers Culm, Ken, Coly and Otter: the first two being river stretches with no documented evidence of Otter populations, and the latter two having documented evidence of Otter populations. Along each of the rivers, 10 sections of 50 m were sampled. In each section, the riparian habitat quality was recorded using the Qualitat del Bosc de Riberia index. The biological water quality was determined by calculating Biological Monitoring Water Party scores, and water chemical concentrations were obtained from Environment Agency data. The riparian habitat quality and biological water quality were found to be of significantly lower quality in the river stretches that did not have evidence of Otter populations when compared with those with Otter populations. The chemical water quality was correlated to biological water quality: the quality being worse in the rivers without evidence of Otter populations. The results of this research suggest that rivers with no evidence of Otter populations are generally of worse riparian quality than those supporting Otter populations.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"125-133"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-01DOI: 10.1093/BIOHORIZONS/HZP019
D. Parker
The effect of sexual conflict upon mating systems is a controversial topic. The aim of this study was to determine whether postcopulatory choice by females (spermatophore removal) reinforces pre-copulatory choice with respect to male body size and fighting ability, and whether such post-copulatory female choice is influenced by post-copulatory mate guarding by males using Platygryllus primiformis (Orthoptera: Gryllidae; Gryllinae). A no-choice test was used to determine the attractiveness of males and spermatophore attachment time was recorded as a measure of cryptic female choice. Females maintained a pre-copulatory mate choice for large males that were more successful in fighting, shown by a shorter latency to copulation. Larger, males that were more successful in fighting were also preferred by post-copulatory cryptic female choice, shown by a longer spermatophore attachment time, reinforcing pre-copulatory mate choice. Males attempted to counter this selection by guarding females, which increased their spermatophore attachment time. Interestingly, spermatophore attachment time increased similarly for all sizes of male as a result of mate guarding, meaning that females maintained their original choice.
{"title":"Pre- and post-copulatory mate choice in Platygryllus primiformis: cryptic female choice and sexual conflict","authors":"D. Parker","doi":"10.1093/BIOHORIZONS/HZP019","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP019","url":null,"abstract":"The effect of sexual conflict upon mating systems is a controversial topic. The aim of this study was to determine whether postcopulatory choice by females (spermatophore removal) reinforces pre-copulatory choice with respect to male body size and fighting ability, and whether such post-copulatory female choice is influenced by post-copulatory mate guarding by males using Platygryllus primiformis (Orthoptera: Gryllidae; Gryllinae). A no-choice test was used to determine the attractiveness of males and spermatophore attachment time was recorded as a measure of cryptic female choice. Females maintained a pre-copulatory mate choice for large males that were more successful in fighting, shown by a shorter latency to copulation. Larger, males that were more successful in fighting were also preferred by post-copulatory cryptic female choice, shown by a longer spermatophore attachment time, reinforcing pre-copulatory mate choice. Males attempted to counter this selection by guarding females, which increased their spermatophore attachment time. Interestingly, spermatophore attachment time increased similarly for all sizes of male as a result of mate guarding, meaning that females maintained their original choice.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"164-171"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-01DOI: 10.1093/BIOHORIZONS/HZP024
H. Lee
Rab5 GTPases are key regulators of vesicular transport. Known plant Rab5 homologues ARA6 and RHA1 have been assigned to the endocytic and/or biosynthetic vesicular trafficking pathway, but conflicting reports in the literature justify further work on these two GTPases. In this project, binary vectors for Agrobacterium-mediated plant transformation were constructed to drive expression in tobacco leaf epidermis of GTP-trapped mutants of ARA6-green fluorescent protein (GFP) and Venus-RHA1. Confocal laser scanning microscopy revealed key differences in the subcellular localization of the two fluorescently tagged GTPase mutants. When present in the GTP-locked configuration ARA6-GFP is primarily found associated with the tonoplast, whereas Venus-RHA1 is significantly cytosolic. Co-expression of the two fluorescently tagged mutant GTPases with the Golgi markers ST-YFP and ST-CFP, respectively, suggest that neither ARA6 nor RHA1 mutants are mis-targeted to the Golgi apparatus and moreover, they do not show any significant colocalization with each other. The results are consistent with the notion that they differ in their roles within the endocytic and biosynthetic vesicular pathway. A future focus to continue this project would be to use GFP-tagged ARA7, the third plant Rab5 homologue, to verify if the high sequence homology between RHA1 and ARA7 warrants overlapping redundant functions or not.
{"title":"Differential localization of two plant homologues of Rab5 GTPases in the secretory pathway","authors":"H. Lee","doi":"10.1093/BIOHORIZONS/HZP024","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP024","url":null,"abstract":"Rab5 GTPases are key regulators of vesicular transport. Known plant Rab5 homologues ARA6 and RHA1 have been assigned to the endocytic and/or biosynthetic vesicular trafficking pathway, but conflicting reports in the literature justify further work on these two GTPases. In this project, binary vectors for Agrobacterium-mediated plant transformation were constructed to drive expression in tobacco leaf epidermis of GTP-trapped mutants of ARA6-green fluorescent protein (GFP) and Venus-RHA1. Confocal laser scanning microscopy revealed key differences in the subcellular localization of the two fluorescently tagged GTPase mutants. When present in the GTP-locked configuration ARA6-GFP is primarily found associated with the tonoplast, whereas Venus-RHA1 is significantly cytosolic. Co-expression of the two fluorescently tagged mutant GTPases with the Golgi markers ST-YFP and ST-CFP, respectively, suggest that neither ARA6 nor RHA1 mutants are mis-targeted to the Golgi apparatus and moreover, they do not show any significant colocalization with each other. The results are consistent with the notion that they differ in their roles within the endocytic and biosynthetic vesicular pathway. A future focus to continue this project would be to use GFP-tagged ARA7, the third plant Rab5 homologue, to verify if the high sequence homology between RHA1 and ARA7 warrants overlapping redundant functions or not.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"205-211"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-01DOI: 10.1093/BIOHORIZONS/HZP014
J.G. Short
Viruses and their hosts since the dawn of time have been battling for supremacy. In recent years, the ‘Interferon Gateway’ encompassing interferon-alpha and -beta (IFN-a/b) expression, signalling and antiviral responses, has been uncovered. IFN-a/b are cytokines that coordinate the innate and adaptive immune responses to eliminate virus infections from the host. Interferon Stimulated Gene (ISG) products, such as protein kinase R, can prevent the translation of viral and cellular mRNAs to limit viral replication and can also initiate apoptosis if the cell is overwhelmed. In order to replicate, viruses have evolved viral evasion proteins that are able to target all aspects of the host response through a variety of sophisticated mechanisms. Viral evasion proteins can encode cellular domains to interact directly with ISGs and neutralize their function, hijack cellular pathways or degrade antiviral components. The high mutation rates associated with viral replication ensure that viruses will continue to adapt to our defences, but equally the viral evasion proteins are novel drug targets for eliminating or managing virus infections.
{"title":"Viral evasion of interferon stimulated genes","authors":"J.G. Short","doi":"10.1093/BIOHORIZONS/HZP014","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP014","url":null,"abstract":"Viruses and their hosts since the dawn of time have been battling for supremacy. In recent years, the ‘Interferon Gateway’ encompassing interferon-alpha and -beta (IFN-a/b) expression, signalling and antiviral responses, has been uncovered. IFN-a/b are cytokines that coordinate the innate and adaptive immune responses to eliminate virus infections from the host. Interferon Stimulated Gene (ISG) products, such as protein kinase R, can prevent the translation of viral and cellular mRNAs to limit viral replication and can also initiate apoptosis if the cell is overwhelmed. In order to replicate, viruses have evolved viral evasion proteins that are able to target all aspects of the host response through a variety of sophisticated mechanisms. Viral evasion proteins can encode cellular domains to interact directly with ISGs and neutralize their function, hijack cellular pathways or degrade antiviral components. The high mutation rates associated with viral replication ensure that viruses will continue to adapt to our defences, but equally the viral evasion proteins are novel drug targets for eliminating or managing virus infections.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"212-224"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60763966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-01DOI: 10.1093/BIOHORIZONS/HZP020
C. Saunders
Epidemiological evidence suggests that diets rich in fruit and vegetables protect against the development of colon cancer, primarily due to their high levels of polyphenols, in particular a group known as flavonoids. Tomatoes contain significant amounts of the glycosides of the flavonoids quercetin and naringenin. Both quercetin and naringenin have been shown to exert anti-proliferative effects on colon cancer cells, although the effects of whole tomato polyphenol extracts are unclear. The aim of this study was to determine the effect of three tomato varieties, with differing levels of flavonoids and total phenolics, on the proliferation of human colon adenocarcinoma cells. We show that all three varieties were able to significantly inhibit the growth of colon cancer cells, although this activity was found not to be linked to the levels of the flavonoids rutin and naringenin in the tomatoes, but rather to their total phenolic content. We show that the mechanism of growth inhibition was linked to the effects of tomato phenolics on the cell cycle, in that exposure of cells to the tomato extract induced a reduction in the percentage of cells in the S-phase, i.e. those actively synthesizing DNA. These data indicate that tomatoes may help to prevent colon cancer but that their flavonoid content does not appear to determine the magnitude of their biological effect.
{"title":"The anti-proliferative effect of different tomato varieties on the human colon adenocarcinoma cells","authors":"C. Saunders","doi":"10.1093/BIOHORIZONS/HZP020","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP020","url":null,"abstract":"Epidemiological evidence suggests that diets rich in fruit and vegetables protect against the development of colon cancer, primarily due to their high levels of polyphenols, in particular a group known as flavonoids. Tomatoes contain significant amounts of the glycosides of the flavonoids quercetin and naringenin. Both quercetin and naringenin have been shown to exert anti-proliferative effects on colon cancer cells, although the effects of whole tomato polyphenol extracts are unclear. The aim of this study was to determine the effect of three tomato varieties, with differing levels of flavonoids and total phenolics, on the proliferation of human colon adenocarcinoma cells. We show that all three varieties were able to significantly inhibit the growth of colon cancer cells, although this activity was found not to be linked to the levels of the flavonoids rutin and naringenin in the tomatoes, but rather to their total phenolic content. We show that the mechanism of growth inhibition was linked to the effects of tomato phenolics on the cell cycle, in that exposure of cells to the tomato extract induced a reduction in the percentage of cells in the S-phase, i.e. those actively synthesizing DNA. These data indicate that tomatoes may help to prevent colon cancer but that their flavonoid content does not appear to determine the magnitude of their biological effect.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"172-179"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-01DOI: 10.1093/BIOHORIZONS/HZP021
S. Batt
This is the final version of the article. Available from Oxford University Press via the DOI in this record.
这是文章的最终版本。可从牛津大学出版社通过DOI在这一记录。
{"title":"Human attitudes towards animals in relation to species similarity to humans: a multivariate approach","authors":"S. Batt","doi":"10.1093/BIOHORIZONS/HZP021","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP021","url":null,"abstract":"This is the final version of the article. Available from Oxford University Press via the DOI in this record.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"180-190"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-01DOI: 10.1093/BIOHORIZONS/HZP010
Matthew G. Lamont
Deep cerebellar nuclei (DCN) form three symmetrical, bilateral nuclei, deep within the white matter of the cerebellum and represent the sole output of the cerebellum to the central nervous system. Although innervated by spontaneously active inhibitory Purkinje cells, DCN neurons also fire action potentials spontaneously at a relatively high frequency, a property attributed to Kv3 channels. In the present study, an electrophysiological approach was carried out on DCN neurons, the purpose of which was to investigate the properties and elucidate the involvement of Kv3 channels. Using whole-cell patch clamp techniques, electrophysiological recordings from the dentate nucleus were obtained from coronal cerebellar slices of Wistar rats (P 12) in both current and voltage clamp modes. Kv3-mediated currents were investigated in the presence of tetrodotoxin (1 mM), by applying low concentration tetraethyl ammonium (TEA) (100 mM). Current-clamp recordings revealed a population of tonically firing neurons, exhibiting a maximum action potential firing frequency of 18.1+ 6.9 Hz and a steady firing frequency of 14.2+4.8 Hz (n 1⁄4 6). These neurons were also shown to exhibit a mean action potential amplitude of 48.7+ 9.5 mV, mean half-width of 2.9+ 1 ms and mean afterhyperpolarization amplitude of 19.6+ 7.5 mV. Depolarizing sag (indicative of the Ih current), followed by rebound depolarization, was observed in all neurons. Voltageclamped neurons revealed a voltage-dependent slowly inactivating outward current with a peak amplitude of 1538.5+1096.6 pA (n 1⁄4 10). Application of low concentration TEA (100 mM) reduced the current by a statistically significant 19.4+13.4% (P, 0.05; paired t-test) and this effect was reversible. Application of a Boltzmann function yielded a V1/2 value of 9.9 mV for the TEA-sensitive current. As Kv3 channels have been previously localized in DCN, the results suggest that the TEA-sensitive current ( 20% of the total outward current exhibited) is mediated by Kv3 channels.
{"title":"An electrophysiological analysis of deep cerebellar nuclei, with particular focus on Kv3 channels","authors":"Matthew G. Lamont","doi":"10.1093/BIOHORIZONS/HZP010","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP010","url":null,"abstract":"Deep cerebellar nuclei (DCN) form three symmetrical, bilateral nuclei, deep within the white matter of the cerebellum and represent the sole output of the cerebellum to the central nervous system. Although innervated by spontaneously active inhibitory Purkinje cells, DCN neurons also fire action potentials spontaneously at a relatively high frequency, a property attributed to Kv3 channels. In the present study, an electrophysiological approach was carried out on DCN neurons, the purpose of which was to investigate the properties and elucidate the involvement of Kv3 channels. Using whole-cell patch clamp techniques, electrophysiological recordings from the dentate nucleus were obtained from coronal cerebellar slices of Wistar rats (P 12) in both current and voltage clamp modes. Kv3-mediated currents were investigated in the presence of tetrodotoxin (1 mM), by applying low concentration tetraethyl ammonium (TEA) (100 mM). Current-clamp recordings revealed a population of tonically firing neurons, exhibiting a maximum action potential firing frequency of 18.1+ 6.9 Hz and a steady firing frequency of 14.2+4.8 Hz (n 1⁄4 6). These neurons were also shown to exhibit a mean action potential amplitude of 48.7+ 9.5 mV, mean half-width of 2.9+ 1 ms and mean afterhyperpolarization amplitude of 19.6+ 7.5 mV. Depolarizing sag (indicative of the Ih current), followed by rebound depolarization, was observed in all neurons. Voltageclamped neurons revealed a voltage-dependent slowly inactivating outward current with a peak amplitude of 1538.5+1096.6 pA (n 1⁄4 10). Application of low concentration TEA (100 mM) reduced the current by a statistically significant 19.4+13.4% (P, 0.05; paired t-test) and this effect was reversible. Application of a Boltzmann function yielded a V1/2 value of 9.9 mV for the TEA-sensitive current. As Kv3 channels have been previously localized in DCN, the results suggest that the TEA-sensitive current ( 20% of the total outward current exhibited) is mediated by Kv3 channels.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"2 1","pages":"55-63"},"PeriodicalIF":0.0,"publicationDate":"2009-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60763905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-01DOI: 10.1093/BIOHORIZONS/HZP003
J. Berry, N. Bulleid
This work explores the role of the thiol-oxidoreductase ERp57 in the post-translational oxidative folding of the low-density lipoprotein receptor (LDL-R), a cell-surface glycoprotein responsible for the uptake of cholesterol from plasma. The LDL-R provides a general model to analyse oxidative folding of multi-domain proteins in the endoplasmic reticulum; yet its folding pathway is also of specific interest as a high proportion of mutations in disulphide-rich domains of the protein are evident in familial hypercholesterolemia. Previous studies have suggested that the LDL-R forms a set of distinct non-native disulphide intermediates during folding, which are extensively isomer- ized prior to secretion of the native conformer. In addition, ERp57 has been suggested to be predominantly reduced in vivo and to form a mixed disulphide with the LDL-R. In this study, the LDL-R was expressed in both wild-type cells and those lacking the thiol-oxidoreduc- tase ERp57 under conditions that prevent disulphide formation. The protein was then allowed to fold under oxidizing conditions, and samples taken at various timepoints. The electrophoretic mobility of folding intermediates from knock-out cells was compared with that of wild-type cells. The results show that dissimilar disulphide intermediates form between the two cell types, particularly during early stages of folding. A mutant form of ERp57, able to form but unable to resolve mixed disulphides, was also found to form mixed dis- ulphides with the LDL-R. The results signify the requirement for ERp57 in oxidative folding of the LDL-R and also suggest that non- native disulphide intermediates may be central to the process of multi-domain protein folding.
{"title":"ERp57 is involved in the oxidative folding of the low-density lipoprotein receptor in the endoplasmic reticulum","authors":"J. Berry, N. Bulleid","doi":"10.1093/BIOHORIZONS/HZP003","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZP003","url":null,"abstract":"This work explores the role of the thiol-oxidoreductase ERp57 in the post-translational oxidative folding of the low-density lipoprotein receptor (LDL-R), a cell-surface glycoprotein responsible for the uptake of cholesterol from plasma. The LDL-R provides a general model to analyse oxidative folding of multi-domain proteins in the endoplasmic reticulum; yet its folding pathway is also of specific interest as a high proportion of mutations in disulphide-rich domains of the protein are evident in familial hypercholesterolemia. Previous studies have suggested that the LDL-R forms a set of distinct non-native disulphide intermediates during folding, which are extensively isomer- ized prior to secretion of the native conformer. In addition, ERp57 has been suggested to be predominantly reduced in vivo and to form a mixed disulphide with the LDL-R. In this study, the LDL-R was expressed in both wild-type cells and those lacking the thiol-oxidoreduc- tase ERp57 under conditions that prevent disulphide formation. The protein was then allowed to fold under oxidizing conditions, and samples taken at various timepoints. The electrophoretic mobility of folding intermediates from knock-out cells was compared with that of wild-type cells. The results show that dissimilar disulphide intermediates form between the two cell types, particularly during early stages of folding. A mutant form of ERp57, able to form but unable to resolve mixed disulphides, was also found to form mixed dis- ulphides with the LDL-R. The results signify the requirement for ERp57 in oxidative folding of the LDL-R and also suggest that non- native disulphide intermediates may be central to the process of multi-domain protein folding.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"47 1","pages":"13-21"},"PeriodicalIF":0.0,"publicationDate":"2009-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZP003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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