Changes In Tissue Ultrastructure Research Articles

Spatiotemporal changes in mechanical matrisome components of the human ovary from prepuberty to menopause.

Spatiotemporal changes in mechanical matrisome components of the human ovary from prepuberty to menopause.

Environmentally relevant concentration of chromium activates Nrf2 and alters transcription of related XME genes in liver of zebrafish

Fish is an excellent model to decipher the mechanism of toxicity of aquatic contaminants such as hexavalent chromium (Cr [VI]). The present study looked into the manifestation of stress in liver of zebrafish exposed to an environmentally relevant concentration (2 mgL−1), and the functioning of the cytoprotective machinery that pacifies the formed stress. The results lead us to hypothesize that oxidative stress plays a key role in chromium-induced toxicity resulting in lipid peroxidation and extensive changes in tissue ultrastructure. In treated fish, production of reactive oxygen species, increase in reduced glutathione content and increase in malondialdehyde content along with enhanced catalase activity were evident. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) was found to increase both at transcriptional and translational level and its translocation into the nucleus was confirmed by fluorescence-based immunohistochemical studies. The mRNA levels of genes like Nqo1, Cyp1a and Cu/Zn Sod were found to increase whereas Ho1, Hsp70 and Ucp2 were down-regulated. The sensitivity of these genes towards Cr [VI] validates their candidature as important biomarkers of Cr [VI] exposure in zebrafish.

The Germinal Epithelium of the Testis in Children with Cryptorchidism in the Ultrastructural Section

Relevance. Male fertility is largely dependent on the timely testicular descent into the scrotum and the formation of the two major divisions of the testis: interstitial and seminiferous tubules.
 The purpose of research - to reveal ultrastructural changes in the germinal epithelium of the testes with cryptorchidism and assess their degree of severity of patients of different age.
 Materials and methods. To study the ultrastructure of testis in 30 children with inguinal retention testicular biopsy runtime relegated gonads were done. Before surgery clinically and sonographically determined testicle in the groin area. Children age 1 to 14 years. All the children with unilateral cryptorchidism. In the study of testicular tissue ultrastructural changes in cryptorchidism revealed 3 types of state tubules and germinal epithelium. Changes in type I revealed 4 cases (13%). In type II tubules in the testis revealed mixed cell type: along with light cells therein are determined cells with dark cytoplasm and signs of destruction - 13 boys (46.4%). In 11 (37%) boys identified type III tubules dominated cells with signs of degradation.
 Conclusions. The study revealed destructive changes of the germinal epithelium of the seminiferous tubules with cryptorchidism: vacuolization of cytoplasm, cytoplasmic foci of local degradation of the matrix, swelling of mitochondria, cristae destruction and devastation of the mitochondrial matrix, pycnosis cores and peritubular interstitial testicular sclerosis, signs of microcirculation disorders.

Ultrastructural changes during the fatigue of bone

Repetitive mechanical loading of bone can lead to ultrastructural-level damage, which can lead to fracture if not repaired. Skeletal fractures result not only from a loss in bone mass, but also because of alterations in tissue quality. Therefore, it is important to also delineate how changes in tissue ultrastructure affect the mechanistic response of bone to its physical environment. In this overview, factors affecting tissue quality, in particular fatigue resistance, are reviewed, followed by examples of recent work that has identified ultrastructural and compositional changes that occur in bone during fatigue.

Survival, feeding and embryo development of Gyrodactylus gasterostei (Monogenea: Gyrodactylidae).

Viviparous gyrodactylid monogeneans which are detached from their host may form an important source of infection in fish communities. This is particularly significant for these ectoparasites which have no specific free-living stage and where transmission usually occurs through transfer of adult parasites when fish come into close contact. In this study, in vitro survival of Gyrodactylus gasterostei was correlated with changes in tissue ultrastructure of parents and their embryos during detachment and following return to a host. At 10 degrees C, detached worms survived for up to 89 h (50%) survival = 20 h) with mortality influenced by both age-independent and age-dependent factors. The gastrodermis of attached, fed parasites is syncytial and contains a variety of vesicles and feeding vacuoles. However, following detachment and starvation, degenerative changes occur within the gastrodermis, eventually leading to marked damage to the embryo/s. When starved worms reattached to a fish, they began browsing on host epithelial cells within 1 min and ultrastructural evidence for phagocytic activity in the gastrodermis was detected after 5 min. Putative waste vacuoles increased in abundance after 5-30 min on the new host, coinciding with the reappearance of electron-dense vesicles and possibly indicating completion of the first intracellular cycle of digestion. Parental feeding directly influenced the normal cyclical maturation and regression of the uterine lining between births. In extreme cases, starvation led to detached parasites (6.1%) aborting their embryos. However, even short periods off the host influenced development and survival of embryos, suggesting that temporary interruption of nutrient flow to the embryo can significantly affect gyrodactylid reproductive rates.

Effect of lidocaine on cholera vibrio-induced changes in the jejunum, renal medulla, and lungs of suckling rabbits

Lidocaine injected into suckling rabbits infected with a virulent strain ofVibrio cholerae abolishes the development of hydropic and ballooning degeneration the jejunal enterocytes. Secretory granules and lipid inclusions accumulate in jejunal enterochromaffin cells and interstitial cells of renal medulla, respectively, and are not released into the vascular bed. In pulmonary tissue ultrastructural changes are mild, and capillary epithelium is undamaged, indicating that lidocaine stimulates pulmonary enzymes which inactivate biologically active substances implicated in the pathogenesis of cholera.

Amiodarone toxicity: II. Desethylamiodarone-induced phospholipidosis and ultrastructural changes during repeated administration in rats

The contribution of desethylamiodarone (DEA), principal metabolite of the antiarrhythmic drug amiodarone, to the major side effects of amiodarone is unclear. The effects of repeated DEA administration to rats on tissue drug accumulation, ultrastructural changes, and phospholipid concentrations were studied. Two groups ( n = 8/group) of male Sprague-Dawley rats (250 g body wt) were administered a 5% aqueous solution of DEA (Dose I, 40 mg/kg/day; Dose II, 60 mg/kg/day) intraperitoneally for 21–23 days, while a third group (control, n = 8) received saline. DEA levels were significantly higher with Dose II compared to Dose I in the lung, liver, kidney, spleen, heart, and serum while the tissue to serum ratios were similar with both doses for all tissues except the heart. DEA administration caused a significant elevation in the lipid phosphorus levels of liver, lung, and alveolar macrophages compared to control levels. A strong positive correlation ( p < 0.01) was found between tissue DEA levels and lipid phosphorus for the above tissues. Electron microscopy revealed the presence of lipid inclusion bodies in liver, lung, and alveolar macrophages of DEA-treated rats. A dose-dependent increase in the percentage of vacuolar surface area was found in the lung and alveolar macrophages. The tissue ultrastructural changes after repeated DEA dosing were qualitatively similar to our previous findings with amiodarone. Increased lung and liver phospholipid levels with repeated DEA doses may result from a potent inhibitory action of DEA on tissue phospholipase A as has been observed by others in in vitro studies.

Response of Japanese quail fed seed meal from sunflowers grown on a municipal sludge-amended soil: elevation of cadmium in tissues.

Sunflowers were grown on soil amended with 224 metric tons/ha of municipal sewage sludge from Syracuse, N.Y. The yield of sunflower seeds was reduced by 47.2% by the sludge addition. The harvested seeds contained 1.71 ppm dry weight of cadmium. Deoiled seed meal was incorporated as 25 and 50% of semipurified diet and fed to male and female Japanese quail. The concentrations of cadmium were higher in kidney, liver, muscle, and eggs of birds fed the sludge-grown seed meal as compared to control quail. Tissue concentrations of cadmium increased with increasing dietary levels of sludge-grown seed meal. No significant differences (p greater than 0.05) were observed between dietary treatments in the activity of hepatic microsomal p-nitroanisole O-demethylase or aminopyrine N-demethylase in the male birds. Additionally, no mutagenic activity, either direct or with metabolic activation, was found in quail eggs. No observable changes in tissue ultrastructure were observed under electron microscopy in any of the treatment groups. There were no significant (p greater than 0.05) differences among the dietary treatment groups in feed intake, growth rate, egg production, or egg hatchability.

Toxicologic studies with male sheep grazing on municipal sludge-amended soil.

Growing sheep were grazed for 152 d on grass-legume forage growing on soil that had been amended with municipal sewage sludge from Syracuse, N.Y., at 224 metric tons per hectare. Cadmium was higher, but not significantly (p greater than 0.05), in tissues of sheep fed the sludge-grown forage as compared to controls. No significant differences between the sludge or control treatments were found in weight of the complete or cauda epididymis or in percent progressive motility of cauda epididymal sperm. The sludge-treatment group had significantly larger testes (p less than 0.025) when expressed as a percentage of body weight, and higher blood uric acid values (p less than 0.05). There were no observable changes in tissue ultrastructure of liver, kidney, muscle, or testes as examined by electron microscopy in either of the treatment groups. There were no significant differences for rate of animal weight gain, carcass weight, dressing percentage, or quality or yield grade of the carcases between the treatment groups.

Changes in tissue ion contents and ultrastructure of food-deprived immature American eels, Anguilla rostrata (LeSueur)

The fasting-induced ultrastructural and ionic changes which occur in American eel (Anguilla rostrata) tissues were studied following 6 (fasted) and 12 (starved) months of food deprivation. Muscle and liver Na+ and Ca2+ ion contents generally rose at the expense of plasma ion concentrations; K+ levels changed little. The fiber area (size) of red (RM) and white (WM) muscles declined with the length of the fast. However, the relative proportion of RM myofibrils actually increased suggesting that red fiber performance was maintained during the fasting period. WM performance probably drops significantly as a result of a decreased fiber size and the relative volume of myofibrils present. Liver morphometric changes became apparent only after 12 months of food deprivation, although a significant increase was noted in the volume of the cell occupied by endoplasmic reticulum at 6 months. These studies indicate that tissue ultrastructural changes occurred with food deprivation in eels and that these were consistent with previously observed alterations in tissue protein and enzyme activities. It is proposed that these modifications are associated with the mobilization of tissue metabolic reserves, and not necessarily a dramatic metabolic reorganization of American eel tissues during food deprivation.

Ultrastructural Effects of Acute Kepone Treatment in Rats

KeponeR (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta[cd]pentalen-2-one) is an insecticide effective against ants and roaches. It can cause severe toxicity in fishes, birds, rodents and man. Prominent effects include hepatic lipid deposition and hypertrophy, impairment of reproductive capacity and neurological disorders. Mitochondrial oligomycin-sensitive Mg2+-ATPase is also inhibited. The present study is a preliminary investigation of tissue ultrastructural changes accompanying physiological signs of acute toxicity, which after two days treatment include: pronounced hypersensitivity and tremor, various degrees of anorexia and adipsia, and decreased weight gain.Three different series of adult male Sprague-Dawley rats (Charles River or CD-I) were treated by intubation with Kepone in corn oil at a dose of 50 mg per kg for 3 successive days or at 200 ppm in food for 8 days. After ether anesthesia, rats were immediately perfused via a cannula in the left ventricle with 4% p-formaldehyde and 0.5% glutaraldehyde in Millonig's phosphate buffer at pH 7.2 for 20-30 min at 22°C.