Pub Date : 1900-01-01DOI: 10.2174/1874360900801010034
G. Hoffmann, V. Leichtfried, A. Griesmacher, C. Bartenbach, M. Canazei, S. Staggl, W. Schobersberger
Shift work is associated with alterations in physiological circadian patterns resulting in chronic diseases, e.g. cardiovascular disorders or major depression. The intensity and spectral composition of light is known to affect the 24 h- rhythm of our body. We investigated the effects of two different lighting environments on parameters of circadian rhythm and performance in healthy volunteers during an experimental night shift. Test light with a low color temperature was compared to normal light with a higher color temperature. Melatonin synthesis, red and white blood count, blood pressure, heart rate and indicators of performance were analyzed. Nocturnal increases in melatonin were more pronounced under low color temperature lighting conditions. This was not associated with limited degrees of arousal or vigilance. Mainte- nance of a normal nocturnal rhythm of melatonin with adapted illumination may provide a benefit for employees well- being without affecting their productivity.
{"title":"Effects of Light With Reduced Short Wavelength Components on Parameters of Circadian Rhythm and Performance in an Experimental Night Shift Model","authors":"G. Hoffmann, V. Leichtfried, A. Griesmacher, C. Bartenbach, M. Canazei, S. Staggl, W. Schobersberger","doi":"10.2174/1874360900801010034","DOIUrl":"https://doi.org/10.2174/1874360900801010034","url":null,"abstract":"Shift work is associated with alterations in physiological circadian patterns resulting in chronic diseases, e.g. cardiovascular disorders or major depression. The intensity and spectral composition of light is known to affect the 24 h- rhythm of our body. We investigated the effects of two different lighting environments on parameters of circadian rhythm and performance in healthy volunteers during an experimental night shift. Test light with a low color temperature was compared to normal light with a higher color temperature. Melatonin synthesis, red and white blood count, blood pressure, heart rate and indicators of performance were analyzed. Nocturnal increases in melatonin were more pronounced under low color temperature lighting conditions. This was not associated with limited degrees of arousal or vigilance. Mainte- nance of a normal nocturnal rhythm of melatonin with adapted illumination may provide a benefit for employees well- being without affecting their productivity.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128268556","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 : 1900-01-01DOI: 10.2174/1874360900901010028
R. Davey, A. Notini, W. Chiu, J. Hodge, G. Nicholson, J. Zajac, A. Turner
We assessed androgen receptor (AR) expression in osteoclasts in vitro and in situ. Rat multinucleated osteo- clasts expressed detectable AR protein in situ, and AR mRNA was detected in mouse and human derived osteoclast-like cells in vitro. Dihydrotestosterone treatment did not affect human osteoclast-like cell formation or resorption in vitro.
{"title":"Androgen Receptor Expression and Function in Osteoclasts","authors":"R. Davey, A. Notini, W. Chiu, J. Hodge, G. Nicholson, J. Zajac, A. Turner","doi":"10.2174/1874360900901010028","DOIUrl":"https://doi.org/10.2174/1874360900901010028","url":null,"abstract":"We assessed androgen receptor (AR) expression in osteoclasts in vitro and in situ. Rat multinucleated osteo- clasts expressed detectable AR protein in situ, and AR mRNA was detected in mouse and human derived osteoclast-like cells in vitro. Dihydrotestosterone treatment did not affect human osteoclast-like cell formation or resorption in vitro.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"255 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133015440","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 : 1900-01-01DOI: 10.2174/1874360900801010044
X. Mao, P. Archambeau, Waheed Baqai, S. Larsen, J. Archambeau
Progressive evolution of retinal vascular in diabetic retinopathy leads to blindness in up to 8,000 patients yearly. The major purpose of this investigation was to determine proton radiation dose response of the eye's retinal vascu- lature in the hypergalactosemia induced rat model of diabetic-like retinopathy and gain insight of possible role of proton radiotherapy in controlling diabetic retinopathy. A single dose range of proton radiation (8, 14, and 20 Gy) was delivered to one eye of each rat at 4 months following induction of hypergalactosemia. The opposite eye of each rat, which was not irradiated, showed normal progression of retinopathy. Stereologic techniques were used to quantify tissue parameters in situ in a retinal digest preparation that allowed unobstructed access to the vasculature. 15 months following 50% galactose diet, characteristic histopathological lesions of retinopathy such as capillary endothelial cell proliferation, capillary clo- sure, capillary microaneurysms, pericyte loss developed in non-irradiated eyes. The endothelial cell densities for rat re- ceiving 50% galactose diet were significantly higher than that of control (p<0.05). Proton irradiation inhibited significant endothelial cell proliferation at dose from 14Gy to 20Gy (p<0.05), yet not diminished pericyte loss at current dose sched- ule. These findings indicated beneficial effects of proton radiation on hypergalactosemia induced diabetic-like retinopa- thy. Our study should have an impact on further studies to optimize radiation treatment strategies for diabetic retinopathy.
{"title":"Radiobiological Study of Retinal Microvessel Proliferation in Diabetic-like Rat Model","authors":"X. Mao, P. Archambeau, Waheed Baqai, S. Larsen, J. Archambeau","doi":"10.2174/1874360900801010044","DOIUrl":"https://doi.org/10.2174/1874360900801010044","url":null,"abstract":"Progressive evolution of retinal vascular in diabetic retinopathy leads to blindness in up to 8,000 patients yearly. The major purpose of this investigation was to determine proton radiation dose response of the eye's retinal vascu- lature in the hypergalactosemia induced rat model of diabetic-like retinopathy and gain insight of possible role of proton radiotherapy in controlling diabetic retinopathy. A single dose range of proton radiation (8, 14, and 20 Gy) was delivered to one eye of each rat at 4 months following induction of hypergalactosemia. The opposite eye of each rat, which was not irradiated, showed normal progression of retinopathy. Stereologic techniques were used to quantify tissue parameters in situ in a retinal digest preparation that allowed unobstructed access to the vasculature. 15 months following 50% galactose diet, characteristic histopathological lesions of retinopathy such as capillary endothelial cell proliferation, capillary clo- sure, capillary microaneurysms, pericyte loss developed in non-irradiated eyes. The endothelial cell densities for rat re- ceiving 50% galactose diet were significantly higher than that of control (p<0.05). Proton irradiation inhibited significant endothelial cell proliferation at dose from 14Gy to 20Gy (p<0.05), yet not diminished pericyte loss at current dose sched- ule. These findings indicated beneficial effects of proton radiation on hypergalactosemia induced diabetic-like retinopa- thy. Our study should have an impact on further studies to optimize radiation treatment strategies for diabetic retinopathy.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127760818","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 : 1900-01-01DOI: 10.2174/1874360900801010023
Analía M. Furio, Ramiro Fontão, N. Falco, J. Ruiz, R. Caccuri, D. Cardinali
Dexamethasone has a neurotoxic action on rodent hippocampus. The objective of this study was to examine the extent of neuroprotection exerted by melatonin on that neurotoxic effect. A group of 24 rats received 9 daily subcutaneous injections of 0.5 mg/kg of dexamethasone. Half of them received 25 μg/ml of melatonin in the drinking water for 10 days. Controls included rats injected with vehicle or rats injected with vehicle plus melatonin in the drinking water. At the end of treatment, the brains were processed for a morphometric analysis, the results being expressed as percent number of ab- normal hipoccampal neurons (defined as necrotic cells) per field. Melatonin decreased by 77 % the effect of dexametha- sone (p< 0.001). A laterality of neurotoxic effect of dexamethasone was apparent in rats that did not receive melatonin (percent of necrotic cells in left and right hippocampus: 32.0 ± 4.4 and 19.6 ± 1.9 %, respectively, p< 0.01). The results indicate a protective effect of melatonin on glucocorticoid neurotoxicity in the rat hippocampus.
{"title":"Neuroprotective Effect of Melatonin on Glucocorticoid Toxicity in the Rat Hippocampus","authors":"Analía M. Furio, Ramiro Fontão, N. Falco, J. Ruiz, R. Caccuri, D. Cardinali","doi":"10.2174/1874360900801010023","DOIUrl":"https://doi.org/10.2174/1874360900801010023","url":null,"abstract":"Dexamethasone has a neurotoxic action on rodent hippocampus. The objective of this study was to examine the extent of neuroprotection exerted by melatonin on that neurotoxic effect. A group of 24 rats received 9 daily subcutaneous injections of 0.5 mg/kg of dexamethasone. Half of them received 25 μg/ml of melatonin in the drinking water for 10 days. Controls included rats injected with vehicle or rats injected with vehicle plus melatonin in the drinking water. At the end of treatment, the brains were processed for a morphometric analysis, the results being expressed as percent number of ab- normal hipoccampal neurons (defined as necrotic cells) per field. Melatonin decreased by 77 % the effect of dexametha- sone (p< 0.001). A laterality of neurotoxic effect of dexamethasone was apparent in rats that did not receive melatonin (percent of necrotic cells in left and right hippocampus: 32.0 ± 4.4 and 19.6 ± 1.9 %, respectively, p< 0.01). The results indicate a protective effect of melatonin on glucocorticoid neurotoxicity in the rat hippocampus.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"71 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120895832","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 : 1900-01-01DOI: 10.2174/1874360900801010001
R. Hardeland, B. Poeggeler
The perception of melatonin as a mediator of darkness, formed in a circadian fashion, circulating in subnano- molar concentrations, and removed as 6-sulfatoxymelatonin, reflects only a sector within a spectrum of actions. This ubiquitous compound present in bacteria and eucaryotes is exceptionally pleiotropic, in terms of binding proteins, receptor distribution, G protein coupling, electron-exchange reactions, and secondary effects by metabolites, such as 5- methoxytryptamine and methoxylated kynuramines. Membrane receptors are located, e.g., in the vertebrate suprachias- matic nucleus, pars tuberalis, brain, vasculature, and leukocytes. Binding proteins include quinone reductase 2, ROR/RZR transcription factors, calmodulin, calreticulin, nuclear and mitochondrial proteins. Actions via hormonal subsystems, growth factors, neurotransmission and immune system lead to further secondary effects. Single-electron transfer reactions are basis of radical scavenging, non-enzymatic metabolism and interactions with electron transport systems. The metabo- lite, N 1 -acetyl-5-methoxykynuramine, is a potent inhibitor of prostaglandin synthesis and of neuronal NO synthase, an NO scavenger and a mitochondrial modulator.
{"title":"Melatonin Beyond Its Classical Functions","authors":"R. Hardeland, B. Poeggeler","doi":"10.2174/1874360900801010001","DOIUrl":"https://doi.org/10.2174/1874360900801010001","url":null,"abstract":"The perception of melatonin as a mediator of darkness, formed in a circadian fashion, circulating in subnano- molar concentrations, and removed as 6-sulfatoxymelatonin, reflects only a sector within a spectrum of actions. This ubiquitous compound present in bacteria and eucaryotes is exceptionally pleiotropic, in terms of binding proteins, receptor distribution, G protein coupling, electron-exchange reactions, and secondary effects by metabolites, such as 5- methoxytryptamine and methoxylated kynuramines. Membrane receptors are located, e.g., in the vertebrate suprachias- matic nucleus, pars tuberalis, brain, vasculature, and leukocytes. Binding proteins include quinone reductase 2, ROR/RZR transcription factors, calmodulin, calreticulin, nuclear and mitochondrial proteins. Actions via hormonal subsystems, growth factors, neurotransmission and immune system lead to further secondary effects. Single-electron transfer reactions are basis of radical scavenging, non-enzymatic metabolism and interactions with electron transport systems. The metabo- lite, N 1 -acetyl-5-methoxykynuramine, is a potent inhibitor of prostaglandin synthesis and of neuronal NO synthase, an NO scavenger and a mitochondrial modulator.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120858865","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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