Analysis Tools
digestive/alimentary system
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• intestinal epithelium brush borders are highly fragile
• brush borders show highly rudimentary rootlets composed of only few short filaments going beyond the level of plasma membrane
• composition of the terminal web, including that of alpha-II-spectrin, myosin IIa, tropomyosin and actin, but not of the microvilli, is altered
• however, distribution of the major cell types of the intestinal epithelium are unaltered and no changes in the organization of villi or crypts is seen
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• microvilli of enterocytes are 20% shorter and show a slight basal constriction
• microvilli of enterocytes lack actin rootlets
• the zone of organelle exclusion from the apical part of the cytoplasm of microvilli is narrowed to about 40% of its width
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• transepithelial resistance in the jejunum is reduced, however the structure of the junctional complexes is preserved
• mice show increased epithelium renewal in the intestine
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• increase in apoptosis rate in the intestinal epithelium
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• mice exhibit increased sensitivity to DSS-induced colitis, developing colitis with anal bleeding or prolapse occurring at day 5 compared to day 7 in wild-type mice
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• females are more sensitive to DSS-induced colitis, with a 50% survival rate at 9 days compared to 12 days for wild-type females, while survival rates of males are no different from wild-type males despite the earlier onset of symptoms
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cellular
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• increase in apoptosis rate in the intestinal epithelium
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immune system
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• mice exhibit increased sensitivity to DSS-induced colitis, developing colitis with anal bleeding or prolapse occurring at day 5 compared to day 7 in wild-type mice
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• females are more sensitive to DSS-induced colitis, with a 50% survival rate at 9 days compared to 12 days for wild-type females, while survival rates of males are no different from wild-type males despite the earlier onset of symptoms
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mortality/aging
| N |
• life span is normal
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• females are more sensitive to DSS-induced colitis, with a 50% survival rate at 9 days compared to 12 days for wild-type females, while survival rates of males are no different from wild-type males despite the earlier onset of symptoms
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hearing/vestibular/ear
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• within the same bundle, a mixture of normal-looking and abnormal stereocilia are frequently observed
• stereocilia of adults are frequently thinner, unusually bent, and of variable length within the same row
• some stereocilia are reduced in width along their entire length, whereas in others, the distal end of the stereocilium is thinner than the proximal end
• in the top region of inner hair cell stereocilia, interfilament distance is slightly, but significantly, increased
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• most inner hair cells and outer hair cells are present in 4 month old mice although a higher degree of outer hair cell loss, particularly in the basal turn, is seen
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• young adult stereocilia of inner hair cells are reduced in length
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• stereocilia of outer hair cells are less affected, however they show signs of degeneration in ageing mice
• by 2 months of age, variations in width on some outer hair cells is seen
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• the stereociliary bundles of outer hair cells are similar to wild-type in overall appearance, however, by 2 months of age, there is evidence of stereocilia fusion and variations in width on some outer hair cells
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• young adult stereocilia of inner hair cells are reduced in width
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• mechanoelectrical transducer currents from P5-P8 apical-coil outer hair cells exhibit minor changes in their adaptation properties, showing a slowing of the fast adaptation
• however, basolateral membrane properties of inner hair cells develop normally
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• mice show increased thresholds of auditory brainstem responses to click stimuli and to tone pips in 4-month and older than 6 months of age mice
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• mice show moderate form of hearing loss in young adults (10-20 dB), progressing to a severe loss (40-50 dB) with age
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nervous system
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• within the same bundle, a mixture of normal-looking and abnormal stereocilia are frequently observed
• stereocilia of adults are frequently thinner, unusually bent, and of variable length within the same row
• some stereocilia are reduced in width along their entire length, whereas in others, the distal end of the stereocilium is thinner than the proximal end
• in the top region of inner hair cell stereocilia, interfilament distance is slightly, but significantly, increased
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• most inner hair cells and outer hair cells are present in 4 month old mice although a higher degree of outer hair cell loss, particularly in the basal turn, is seen
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• young adult stereocilia of inner hair cells are reduced in length
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• stereocilia of outer hair cells are less affected, however they show signs of degeneration in ageing mice
• by 2 months of age, variations in width on some outer hair cells is seen
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• the stereociliary bundles of outer hair cells are similar to wild-type in overall appearance, however, by 2 months of age, there is evidence of stereocilia fusion and variations in width on some outer hair cells
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• young adult stereocilia of inner hair cells are reduced in width
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• mechanoelectrical transducer currents from P5-P8 apical-coil outer hair cells exhibit minor changes in their adaptation properties, showing a slowing of the fast adaptation
• however, basolateral membrane properties of inner hair cells develop normally
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behavior/neurological
| N |
• normal food intake and stool production
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growth/size/body
| N |
• body size and weight are normal
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homeostasis/metabolism
| N |
• mice show normal glucose, cholesterol, triglyceride and creatinine levels
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reproductive system
| N |
• mice are fertile and show a normal reproductive rate
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