Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0276640 (TEM)
 20,729 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hair cells of the avian inner ear have been shown to regenerate following acoustic or ototoxic insult. The consequences of this regeneration on the acoustic nerve have yet to be defined. The purpose of the present study was to use TEM analysis following cochlear damage and hair cell regeneration to describe afferent and efferent neural terminals on hair cells in the newly repopulated sensory epithelium. Following acoustic overstimulation (12 h, 115 dB SPL, 1500 Hz) adult quail were sacrificed immediately (0 day), or at 2, 12, or 24 weeks. Serial thin sections were taken from the embedded papilla in a plane tangential to the basilar membrane in the area consistent with regenerative activity. Immediately following noise exposure very few hair cells could be seen within the epithelia; afferent terminals on remaining cells appeared normal. Two weeks later afferent terminals showed signs of degeneration; efferent terminals were rarely seen on tall hair cells but remained relatively normal on short hair cells. Three to six months later afferent terminals had regained a more normal appearance but were less numerous on tall hair cells; some return of efferent-like terminals was seen often contacting two tall hair cells. Large normal appearing, efferent terminals remained on short hair cells. These results suggest that regenerated hair cells are likely to receive neural innervation. It would appear that some degeneration of afferent terminals takes place prior to final innervation of new hair cells.
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PMID:Changes in the acoustic nerve after hair cell regeneration. 172 65

Guinea pigs were exposed to pressure wave with a peak pressure value of 175.3dB (SPL). Vestibular test and stereoscopic and TEM observations were performed after the exposure. Vestibular function was normal. Within 48 hours of exposure, slight mechanical injuries of the sensory cells in both the creista and macula were observed, such as displacement of the otolithic membrane, distortion and fusion of cilia and protrusion of the cytoplasm. On the 7th and 14th day, these changes became less marked, but a few cells showed swelling of mitochondria and nerve chalice and abnormalities of afferent nerve terminals, which were supposed to be resulted from metabolic disorders. The significance of these changes was discussed.
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PMID:[Pressure wave-induced damage of the vestibular apparatus in guinea pigs. A transmission electron microscopic study]. 236 81

Morphologic changes in the tegmentum vasculosum (TV) of adult quail after high intensity sound exposure were studied. Quail were continuously exposed to 115 dB SPL, 1500 Hz pure tone in a sound field for 12 h and either sacrificed immediately (0 day), 1, 2, 3, 4, 6 or 10 days later. Serial sections through the basilar papilla at 100 micron intervals from base to apex were obtained for study with light microscopy and TEM. Significant morphologic changes were found within the TV of quail sacrificed on days 0-4. On a quantitative scale, the majority of recovery occurred within the first 24 h. After four days survival the tegmentum appeared nearly normal. This recovery correlates well with the temporal pattern of threshold shift recovery. These results demonstrate a temporal correlation between ultrastructural changes in the TV and functional recovery of hearing after intense sound exposure. A potential etiologic role of the TV in avian temporary threshold shift is suggested.
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PMID:Recovery of noise-induced changes in the dark cells of the quail tegmentum vasculosum. 760 91

In the age-dependent pathway, microRNA 156 (miR156) is essential for the correct timing of developmental transitions. miR156 negatively regulates several SPL genes, which promote the juvenile-to-adult and floral transitions in part through upregulation of miR172. The transcriptional repressors TEMPRANILLO1 (TEM1) and TEM2 delay flowering in Arabidopsis thaliana at least through direct repression of FLOWERING LOCUS T (FT) and gibberellin biosynthetic genes, and have also been reported to participate in the length of the juvenile phase. Levels of TEM mRNA and miR156 decrease gradually, allowing progression through developmental phases. Given these similarities, we hypothesized that TEMs and the miR156/SPL/miR172 module could act through a common genetic pathway. We analyzed the effect of TEMs on levels of miR156, SPL and miR172, tested binding of TEMs to these genes using chromatin immunoprecipitation and analyzed the genetic interaction between TEMs and miR172. We found that TEMs played a stronger role in the floral transition than in the juvenile-to-adult transition. TEM1 repressed MIR172A, MIR172B and MIR172C expressions and bound in vivo to at least MIR172C sequences. Genetic analyses indicated that TEMs affect the regulation of developmental timing through miR172.
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PMID:TEMPRANILLO is a direct repressor of the microRNA miR172. 3131 Mar 97