Early morphological and chemical changes induced by cisplatin in the guinea pig organ of Corti

1986 ◽  
Vol 100 (12) ◽  
pp. 1375-1383 ◽  
Author(s):  
Spiro D. Comis ◽  
Peter H. Rhys-Evans ◽  
Michel P. Osborne ◽  
James O. Pickles ◽  
David J. R. Jeffries ◽  
...  

AbstractGuinea pigs were treated with a single dose of Cisplatin (5 mg IP). After 2–4 days the cochleas were prepared for morphological analysis by scanning electron microscopy and chemical analysis by X-ray dispersive microanalysis. Following Cisplatin, the bundles of stereocilia on the hair cells were found to be rough, disarrayed, fused, and finally absorbed. Significant increases were found in the levels of calcium, sulphur, and phosporus in the abnormal hair cells. It is suggested that the high calcium levels might be due to the inhibition of enzymes which normally keep cytoplasmic calcium low, and that some of the changes in the stereocilia might be secondary to this.

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P194-P195
Author(s):  
Gao Xia

Problem Pug is an ENU mutated mouse model for X-linked dominant hypophosphatemic rickets (XLH) in human. Mapping and sequence analysis revealed that Pug mutation is a unique Phe-to-Ser transition at amino acid 80 of PHEX protein leading to the loss of Phex function. Patients with XLH and Pug mutant mice exhibit abnormal phenotypes including growth retardation, hypophosphatemia and osteomalacia. In addition, hearing impairment was also found in some hypophosphatemic mouse models and patients. Here, we used the Pug mutant mice to study the role of Phex gene in the pathology of hearing impairment. Methods Auditory brainstem responses(ABR) to click and 8,16,32kHz stimuli were employed to measure pug mice of 1–8 months old. Serial sections were used to detect the abnormalities involving the temporal bone, stria vascularis, the organ of Corti, spiral ganglion cells, and scanning electron microscopy was performed to exam the basilar membrane of pug mice. Results Auditory brainstem responses test showed that Pug mice have elevated hearing thresholds. Histology analysis demonstrated a thickened temporal bone with many interspersed areas of nonmineralization surrounding the mutant cochlea and decreased numbers of neuronal processes in the organ of Corti, mostly in basal turns. Furthermore, abnormal stereocilia of inner and outer hair cells of the Corti organ were identified by scanning electron microscopy. Inner and outer hair cells were also greatly reduced in Pug mice. Conclusion The impaired hearing function and the morphological abnormalities of inner ears are induced by the mutation of Phex gene. Significance Pug mice have structural and functional defects in the inner ear and may serve as a new disease model of sensorineural deafness. Support This work was supported by the ground of JiangSu Province Femouse Doctor Project(RC2007010).


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
M. L. Zimny ◽  
A. C. Haller

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.


Author(s):  
Yun Lu ◽  
David C. Joy

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.


Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.


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