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At least 1,513 records · Page 84Linked to original sources
PubMed1999

Effects of tea polyphenols on cardiac function and myocardial ultrastructure in rats after repeated +Gz stress.

Objective. To observe the effects of tea polyphenols (TP) on cardiac function and myocardial ultrastructure in rats after repeated +10 Gz stress. Method. Twenty four male Wistar rats were randomly divided into three groups (n=8 each): group A (control), group B (+10 Gz), group C (+Gz with TP). Group B and C were repeatedly exposed to +10 Gz (each for 30 s, onset rate about 0.5 G/s, 3 times/d with +1 Gz 1 min intervals, 3 d/wk, 4 weeks in total), but group A was only submitted to +1 Gz. TP (200 mg kg-1) was given orally to group C about 1 h prior to the +Gz experiment, and distilled water was given to group A and B. Function of isolated rat working hearts and myocardial ultrastructure were observed. Result. A significant decrease of left ventricular systolic pressure (LVSP) and injury of myocardial structure in rats were demonstrated after repeated +10 Gz stress. But TP could remarkably elevate the LVSP and improve myocardial ultrastructural injury in +10 Gz stressed rats. Conclusion. These results indicated that repeated high G exposure may produce cardiac structural and functional injuries in rats which might be partly related to free radical metabolism; and antioxidant TP had significant protective effects on the hearts of +Gz stressed rats.

Acceleration↗
PubMed2002

[Correlation between tissue ultrastructure changes of small testis and sex hormone].

OBJECTIVES: To investigate the tissue ultrastructure changes of small testis and sex hormone and their correlation. METHODS: The patients were divided into small tests (n = 8) and control group(n = 12). FSH, LH, T were determined by radioimmunassay. Diameter and wall thickness of convoluted seminiferous tubule were investigated with light microscope and electro microscopy on small testis tissue morphology and ultrastructure. RESULTS: FSH, LH, T of small testis and control group were (21.05 +/- 9.15) IU/L vs (6.74 +/- 3.52) IU/L, (22.88 +/- 6.25) IU/L vs (6.60 +/- 1.48) IU/L and (0.30 +/- 0.04) nmol/L vs (17.55 +/- 9.25) nmol/L, respectively. Seminiferous tubule diameter and wall thickness were(37.33 +/- 6.80) microns vs (198.46 +/- 29.84) microns and (10.30 +/- 1.82) microns vs (2.95 +/- 0.20) microns. Small testis tissue ultrastructure changed significantly. CONCLUSIONS: Pathologic changes of small testis tissue in many parts such as seminiferous tubule, germinal epithelium, Sertoli cell, Leydig cell, limiting membrance and blood vessel may relate with genetics and immunoreaction.

Adult↗
PubMed2002

[Ultrastructural observation of normal spermatozoa incubated with ROS in vitro].

OBJECTIVES: To observe ultrastructural changes of spermatozoa after incubate with reactive oxygen species (ROS). METHODS: Spermatozoa of normal physiological functions selected from semen samples by Percoll gradient centrifugation technique were regarded as normal sperm models in present study. Ultrastructural changes of spermatozoa observed by transmission electron microscope after model spermatozoa were incubated with ROS generated by hypoxanthine and xanthine oxidase under aerobic environment. RESULTS: After model spermatozoa were incubated with ROS, impairment of various extent in membrane and acrosome of spermatozoa and abnormality in mitochondria of spermatozoa were found. CONCLUSIONS: Excessive ROS may cause ultrastructural change in membrane, acrosome and mitochondria of spermatozoa and impair function of spermatozoa.

Adult↗
PubMed2002

[Ultrastructural observation of detrusor in BPH patients].

OBJECTIVES: To observe the detrusor ultrastructure in BPH patients and to investigate the relationship between detrusor instability and ultrastructure. METHODS: The patients were divided into groups of detrusor instability(DI) and detrusor stability(DS) according to urodynamics examination. The structure of the detrusor were observed by light microscopy and transmission electron microscopy(TEM). RESULTS: The intercellular intermediate junctions and cytoplasmic process junctions in DS were 11.34 +/- 3.23 and 4.26 +/- 1.78 respectively. The intercellular intermediate junctions decreased obviously (3.12 +/- 1.47, P < 0.01) instead of a large amount of cytoplasmic process junctions (26.37 +/- 7.14, P < 0.01) in DI. CONCLUSIONS: There is a close relevance between intercellular junctions and DI. The observation of the ultrastructure of the detrusor is helpful for the diagnosis of BPH with DI and for the clinical treatment.

Aged↗
PubMedDate not supplied

Effects of estradiol benzoate on the ultrastructure of the pinealocyte in the ovariectomized rat.

OBJECTIVE: The aim of this study was to examine the effects of ovariectomy and ovariectomy followed by estradiol benzoate administration on the ultrastructure of pinealocytes in female rat. DESIGN: For this purpose 15 female Wistar rats were used. Animals were divided into three groups. Group I and II were designated as sham-ovariectomized (control) and ovariectomized, respectively. Group III was ovariectomized and daily injected with estradiol benzoate for one month. At the end of the experiment, all animals were anesthetized with ketamine for fixation by vascular perfusion. Pineal glands of groups I, II and III were removed. All specimens were examined by electron microscopy. RESULTS: Ovariectomy caused an increase of lipid droplets, mitochondria and ribosomes. Rough endoplasmic reticulum was extensive in the cytoplasm. Estradiol administration to ovariectomized rats resulted in formation of less extensive lipid droplets, mitochondria and ribosomes compared to pinealocyte ultrastructure of both control and ovariectomized rats. Extensiveness of rough endoplasmic reticulum in the pinealocytes of estradiol-administrated rats was similar to that in controls. CONCLUSIONS: The results confirm relationship between the pineal gland and gonads in the rat and it has been suggested that estradiol benzoate reverses the ultrastructural changes, which indicate increased cell activation, occurring in the pinealocytes after ovariectomy.

Animals↗
PubMed2002

Ultrastructural alterations of endothelium covering advanced atherosclerotic plaque in human carotid artery visualised by scanning electron microscope.

Human atherosclerotic plaque morphology at its various stages was extensively documented using light microscopy. However, much less is known of the ultrastructure of the human atherosclerotic plaque, in particular of ultrastructure of endothelial cells in atherosclerosis. Here, we analysed alterations of endothelial cells covering advanced atherosclerotic plaque in carotid artery using scanning electron microscope. Examination was performed on specimens from atherosclerotic lesions of the interior carotid artery, collected from 8 patients who had undergone endarterectomy. We found wide spectrum of pathological alterations of the luminal surface of atherosclerotic plaque. In dominant part of the vessel, endothelial layer was preserved but displayed pronounced irregularities in endothelial architecture including appearance of cuboidal cells. Some endothelial cells were covered by numerous microvilli and/or contained "craters" disrupting continuous surface of the endothelium. Platelets and leukocytes adhering to endothelium were frequently observed. There were also areas of the vessel lumen with endothelial denudation, in which the subendothelial surface containing fibrin proteins and collagen fibrils were visible. Interestingly, signs of proliferation of endothelial cells tending to cover the partially denuded vessel were observed. In summary, in scanning electron microscope, preserved endothelial cells of advanced atherosclerotic plaque displayed pronounced pathology; whether any of these changes represent the ultrastructural correlate of endothelial dysfunction remains to be established.

Aged↗
PubMed2001

[Ultrastructure changes of electrical injury in rats].

OBJECTIVE: To observe ultrastructure changes of electrical injury in rats. METHODS: An experimental model of rats suffered from the low voltage were designed. Ultrastructure changes of electrical injured tissues were observed under transmission electron microscope. RESULTS: (1) Plasma of epithelium was concreted in the affected areas and inner membrane system was broken. (2) Hypercontraction bands were observed in skeleton muscles. (3) There was dissolved necrosis and hypercontraction bands in the myocardium. (4) Vacuoles were found in plasma of endothelium of blood vessels on electrical current path, and myelin sheath of nerve fiber were loosed. CONCLUSION: The above mentioned ultrastructure changes could be used as assistant diagnostic index of electrocution. The mechanism of the changes were discussed.

Animals↗
PubMedDate not supplied

An ultrastructural evaluation of the effect of hydrocortisone on rabbit cartilage.

Pharmacologic and supra-pharmacologic doses of hydrocortisone acetate did not effect ultrastructural alteration of chondrocytes in articular cartilage of mature rabbits. Early biomechanical alterations are unaccompanied by ultrastructural cytological changes. Not until advanced biochemical alteration is effected by large, repetitive doses, does the ultrastructural alteration begin.

Animals↗
PubMed2001

[Effects of losartan on renal ultrastructure in diabetic rats].

OBJECTIVE: To observe the effects of losartan on renal ultrastructure in streptozotocin diabetic rats. METHODS: Male SD rats were randomly divided into 2 groups: normal control group (NC group) and diabetic group. Diabetic group was induced by streptozocin (65 mg.kg-1) abdominal injection. Four weeks later, diabetic rats were further divided into 2 groups: diabetic rats treated with losartan (DL group, 20 mg.kg-1.d-1, by gavage) and diabetic unteated control group (DC group). Renal ultrastructure of each group was observed before and after 12 weeks of treatment respectively. RESULTS: The ultrastructure alterations in DL group including mesangial expansion and thickening of glomerular basement membrane (GBM), were lighter than those in DC group. CONCLUSION: Losartan can prevent renal pathological progress in diabetic rats. It is suggested that losartan may have some renal protective effects.

Animals↗
PubMed2001

[Experimental study on effect of xinfeng capsule in treating rats' adjuvant arthritis on ultrastructure of synoviocyte and splenic lymphocyte].

OBJECTIVE: To observe the effect of Xinfeng capsule (XFC) on the ultrastructure of synoviocyte and splenic lymphocyte in rat adjuvant arthritis (AA) model. METHODS: Sixty rats were randomly divided into normal control group, model group, XFC group and Tripterygium wilfordii polycoside (TP) group, 15 in each. Complete adjuvant 0.1 ml was injected into right posterior metatarsus of rats subcutaneously to induce inflammation, except that in the normal control. The ultrastructural change including mitochondria swelling, vacuolation and ridge pathologic change of synoviocyte and splenic lymphocyte was observed by transmission electron microscopy (TEM). The mitochondria lesion rate (MLR) of each group was then calculated. RESULTS: The swelling degree of right posterior metatarsus in XFC and TP group obviously lowered after treatment (P < 0.05). MLR of synoviocyte in the XFC group and the TP group after treatment was also obviously lower than that in the model group (P < 0.05). MLR of splenic lymphocyte in the XFC group reduced markedly (P < 0.05) after treatment, while in the TP group, the change was insignificant (P > 0.05). In comparison with TP group, the reduction of both MLR of synoviocyte and splenic lymphocyte after treatment in the XFC group was more significant (P < 0.05). CONCLUSION: XFC could lower the degree of swelling in AA rats like TP did, but XFC could improve ultrastructural change of rat's synovicocyte and splenic lymphocyte better than that of TP, which was likely the morphological basis of XFC's therapeutical effect.

Animals↗
PubMed2002

The influence of nitric oxide synthesis modulation on the pancreatic acinar cells in caerulein-induced acute pancreatitis. An ultrastructural and morphometric study.

The goal of our study was to evaluate the influence of NO synthesis modulation on the ultrastructural changes in the pancreatic acinar cells in connection with morphometric assessment of the volume and numerical densities of mitochondria (Vvm, Nvm) and zymogen granules (Vvz, Nvz) in caerulein-induced acute pancreatitis (AP). During AP induction rats were treated with L-arginine--substrate for NO synthesis, N(G)-nitro-L-arginine (L-NNA)--NO synthase inhibitor, gliceryl trinitrate (NTG)--NO donor, L-arginine+L-NNA or saline. This study demonstrated that administration of L-NNA leads to the formation of numerous, large autophagosomes and mitochondria oedema in pancreatic acinar cells. Treatment with L-arginine or NTG during AP induction resulted in a diminution of the ultrastructural changes with a concomitant increase of Vvz. Vvm and Nvm were significantly lower in the L-arginine treated group compared to the untreated AP. The results indicate that: L-NNA enhances damage to acinar cells which may be indicative of a protective role for endogenous NO in oedematous AP. The application of L-arginine or NTG decreases the damage to acinar cells evaluated ultrastructurally, suggesting the morphological changes accompanying the onset of AP in rats after the administration of either substrate for endogenous NO synthesis or exogenous NO donor follow a favourable course.

Animals↗
PubMed1976

Ultrastructure of mouse mononuclear phagocytes in bone marrow colonies grown in vitro.

Recently a new method was developed to culture bone marrow cells in a liquid medium on a glass surface. Two kinds of colonies develop in these cultures, namely mononuclear phagocyte and granulocyte colonies. The study of the ultrastructure of the cells in the mononuclear phagocyte colonies was the primary aim of the present study. The architecture of the mononuclear phagocyte colonies appeared to be quite different from that of the granulocyte colonies, since in the latter, the cells lie close together in dense clusters, whereas in mononuclear phagocyte colonies the cells are more loosely dispersed with the highest cell density at the center and stellate orientation of the cells at the periphery. However, both kind of colonies grow entirely separate from each other and mixed colonies are not observed. Electron microscopy showed that there are three types of cell in the mononuclear phagocyte colonies, i.e., monoblasts, promonocytes, and macrophages. The ultrastructure of the promonocytes and macrophages of the colonies is similar to that of the same types of cell isolated directly from the mouse. The monoblast, the most immature cell of mononuclear phagocyte colonies has not been characterized before. The ultrastructure of this cell is clearly distinct from that of the promonocyte in having a round contour without pseudopods, a nuclear to cytoplasmic ratio greater than one, a cytoplasm that contains many polyribosomes, a few small granules, and a small Golgi complex surrounded by a few short strips of rough endoplasmic reticulum.

Bone Marrow↗
PubMed1976

Effects of adriamycin on ultrastructure of nucleoli in the heart and liver cells of the rat.

Ultrastructural studies of the effects of adriamycin on liver and cardiac cell nucleoli of the rat showed that nucleolar segregation occurred within 1 hr after an i.v. injection of a 40-mg/kg dose. Between 3 and 27 hr after this single dose, liver cell nucleoli progressively reverted to a normal ultrastructure. Nucleoli of rat myocardial cells did not recover but underwent further fragmentation, segragation, and conversion to ring-shaped structures. The ultrastructural alterations of myocardial cell nucleoli may represent an important aspect of adriamycin toxicity.

Animals↗
PubMed2003

[Morphology of the rat's brain in and after a space flight: ultrastructure of the "blue spot"].

Electron microscopy was used to explore ultrastructure of the livor extracted from the brain of rats on day-13 aboard U.S. space shuttle Columbia (STS-58), and in 5-6 hrs. after landing following the 14-d mission. As compared with the ground controls, the rats flown in microgravity reduced the total number of axodendrite synapses (ADS) by 21% and functional ADS--by 39.7%. After touchdown the total ADS number remained lowered by 16.5%; however, the percentage of highly active ADS exceeded this parameter in the ground controls. Results of the analysis of the ADS number in conjunction with the ultrastructural changes in axonal terminals and dendrites suggest a sharp decrease of the afferent influx towards the livor neurons during microgravity, whereas modifications of the livor neuron ultrastructure point to a decline in their functional activity. These data serve as an experimental proof of the hypothesized development of the hyponoradrenergic syndrome by mammals in microgravity.

Animals↗
PubMed2003

[Ultrastructural study of proprioceptors in extraocular muscles of congenital nystagmus subjects].

OBJECTIVE: To observe the ultrastructure and the light microscopic structure alterations of the proprioceptors in the extraocular muscles (EOM) of congenital nystagmus (CN) subjects and discuss the probable effect and its mechanism of these alterations on CN to approach a new reasonable treatment for CN. METHODS: Twenty-one proprioceptors (muscle spindles) from 8 extraocular muscles of two typical CN were studied under both light microscope and transmission electron microscope. They were compared with 15 proprioceptors obtained from normal fresh cadavers. RESULTS: The proprioceptors in the EOM of CN subjects were smaller and their inner capsules became collapsed, discontinuous and vacuolated. At the same time, the muscle fibers and some endings of sensory nerves of EOMs from CN also had degenerative ultrastructural changes. CONCLUSIONS: The ultrastructure of the proprioceptors, muscle fibers and nerve endings in the EOMs of CN subjects are all changed compared with that of the controls. These alterations probably affect EOM's function and its proprioceptive input, which are probably related to the etiology and pathogenesis of CN.

Adult↗
PubMed2001

[Effects of acute infrasound exposure on vestibular and auditory functions and the ultrastructural changes of inner ear in the guinea pig].

OBJECTIVE: To define the effects of acute infrasound exposure on vestibular and auditory functions and the ultrastructural changes of inner ear in guinea pigs. METHODS: The animals involved in the study were exposed to 8 Hz infrasound at 135dB SPL for 90 minutes in a reverberant chamber. The sinusoidal pendular test (SPT), auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) were respectively detected pre-exposure and at 0(within 2 hrs), 2 and 5 day after exposure. The ultrastructures of the inner ear were observed by scanning electron microscopy. RESULTS: The slow-phase velocity and the frequency of the vestibular nystagmus elicited by sinusoidal pendular test (SPT) declined slightly following infrasound exposure, but the changes were not significant (P > 0.05). No differences in the ABR thresholds, the latencies and the interval peak latencies of I, III, V waves were found between the normal and the experimental groups, and among experimental groups. The amplitudes of DPOAE at any frequency declined remarkably in all experimental groups. The ultrastructures of the inner ear were damaged to different extent. CONCLUSION: Infrasound could transiently depress the excitability of the vestibular end-organs, decrease the function of OHC in the organ of Corti and cause damage to the inner ear of guinea pigs.

Animals↗
PubMed2003

[Effects of mifepristone on ultrastructure of placental Hofbauer cells in early human pregnancy].

OBJECTIVE: To investigate the effects of mifepristone on the ultrastructure of Hofbauer cells in human early pregnant placenta. METHODS: Twenty 6 - 9 week pregnant women with indications of pregnancy termination were recruited and randomly assigned to mifepristone group(n = 10) and D & C group (n = 10). Villi were collected and studied with transmission electron microscope. RESULTS: In comparison with the control group, the ultrastructure of Hofbauer cells of mifepristone group showed the following changes: the cells were markedly edematous. The number of cytoplasmic processes of Hofbauer cells deceased obviously. In the cytoplasm of Hofbauer cells, the size of vacuoles enlarged and of mitochondria minimized. Rough endoplasmic reticulum and Golgi complex were under-developed. Lysosomes were rare. The nuclei enlarged and showed irregular shape. CONCLUSIONS: Mifepristone may change the phagocytosis' water and electrolyte transportation and immunological function of Hofbauer cells by influencing the ultrastructure of the Hofbauer cells. Therefore it can influence the development of pregnancy.

Abortion, Induced↗
PubMed2003

[Ultrastructure of cultured cartilage, articular cartilage, growth plate and meniscus].

OBJECTIVE: To investigate possibility of cartilage cultured in centrifuge tube as graft materials. METHODS: Articular chondrocytes isolated from a 3-week-old rabbit formed cartilage after cultivation for 2 weeks. Articular cartilage of humeral head, growth plate of proximal tibia and meniscus were collected from a 6-week-old rabbit. The ultrastructure of chondrocytes and extracellular matrix in the three kinds of cartilages and cultured cartilage were observed by transmission electronic microscopy. RESULTS: Cartilage cultured in centrifuge tube possessed unique ultrastructure and was similar to articular cartilage and growth plate, but it was markedly different from meniscus. The four kinds of cartilages were characteristic of respectively different chondrocytes and extracellular matrix. Cultured cartilage showed typical apoptosis of chondrocytes and "dark chondrocytes" appeared in growth plate. Condrocyte apoptosis was not seen in articular cartilage and meniscus. CONCLUSION: Cartilage cultured in centrifuge tube has unique ultrastructure and may be used as graft materials for articular cartilage and growth plate.

Animals↗