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PubMed1995

Ultrastructure of cardiac myocytes in the greater bandicoot rat (Bandicota indica).

Cardiac myocytes in the left ventricle and atrium of the greater bandicoot rat (Bandicota indica) were examined by transmission electron microscopy. The fine structure showed typical features of mammalian cardiac myocytes. In atrial myocytes, however, the areas occupied by mitochondria were much smaller than that filled with myofibrils. The decrease in mitochondria and the abundance of myofibrils are thought to be an ultrastructural adaptation to the large body size of this species. Many conducting myocytes were observed in both atrium and ventricle. The atrial conducting myocytes were ultrastructurally different from the Purkinje fibers of the ventricle. We suggest that the abundance and the ultrastructural variation of conducting myocytes are related to the physiological aspects, such as body size, of this animal.

Animals↗
PubMed1998

Sexually dimorphic effects of aging on rat somatotroph cells. An immunohistochemical and ultrastructural study.

Aging produces alterations in certain functions of the hypothalamo-pituitary axis that result in sexually dimorphic changes in the somatotrophs. Since quantitative morphological data on these age-associated alterations are scarce, we prompted to make a morphometric immunohistochemical assessment as well as undertake an ultrastructural study of the somatotrophic (GH) cell population in male and female rats of different ages. Young (3-month-old), old (20-month-old), and senescent (29-month-old) Sprague-Dawley rats of both sexes were sacrificed by rapid decapitation, their pituitaries immediately dissected out, and processed for both immunohistochemistry and electron microscopy. Analysis of different morphometric parameters revealed that surface density, volume density, and cell density significantly decreased in old and senescent rats as compared to young animals, with this reduction being clearly more marked in females. Both the GH-cell area and perimeter decreased in senescent male rats, while these parameters increased in senescent females. The ultrastructure of the GH cells from old and senescent animals of both sexes evinced changes suggestive of an immature state, with some somatotrophs having the appearance of cells undergoing an involutive process. We conclude that aging has a differential impact on the GH cells of male and female rats with respect to the immunohistochemical and ultrastructural features of that cell population.

Aging↗
PubMed2005

Ultrastructural studies and Na+,K+-ATPase immunolocalization in the antennal urinary glands of the lobster Homarus gammarus (Crustacea, Decapoda).

Unlike in crustacean freshwater species, the structure and ultrastructure of the excretory antennal gland is poorly documented in marine species. The general organization and ultrastructure of the cells and the localization of Na(+),K(+)-ATPase were examined in the antennal gland of the adult lobster Homarus gammarus. Each gland is composed of a centrally located coelomosac surrounded ventrally by a labyrinth divided into two parts (I and II) and dorsally by a voluminous bladder. There is no differentiated nephridal tubule between them. The labyrinth and bladder cells have in common a number of ultrastructural cytological features, including basal membrane infoldings associated with mitochondria, apical microvilli, and cytoplasmic extrusions, and a cytoplasm packed with numerous vacuoles, vesicles, lysosome-like bodies, and swollen mitochondria. Each type of cell also presents distinctive characters. Na(+),K(+)-ATPase was detected through immunofluorescence in the basal part of the cells of the labyrinth and in the bladder cells with an increasing immunostaining from labyrinth I to the bladder. No immunoreactivity was detected in the coelomosac. The cells of the labyrinth and of the bladder present morphological and enzymatic features of ionocytes. The antennal glands of the lobster thus possess active ion exchanges capabilities.

Animals↗
PubMed1994

Ultrastructural observation of Pneumocystis carinii in bronchoalveolar lavage fluid from non-AIDS patients with P carinii pneumonia.

To investigate the morphology of Pneumocystis carinii in vivo, we studied the ultrastructure of P carinii in bronchoalveolar lavage fluid (BALF) obtained from four non-AIDS patients with P carinii pneumonia (PCP), and observed the morphologic changes after treatment in one patient. Every form recognized in the normal life cycle of P carinii, ie, thick-walled cysts, crescent-shaped cysts, and trophozoites, was detected in the pretreatment BALF specimens. In the posttreatment BALF, P carinii revealed marked ultrastructural changes such as the elongation of thick-walled cysts, the degeneration of intracystic bodies, and the disappearance of trophozoites. Massive debris derived from P carinii was still found in the BALF even after the treatment. Examination of P carinii in BALF, including ultrastructural observations, might help us to evaluate the disease status and the effect of treatment in patients with PCP.

Aged↗
PubMed1983

Ultrastructural subtypes of pulmonary adenocarcinoma. A correlation with patient survival.

A retrospective study of 34 patients (33 male and one female) was conducted to evaluate a potential correlation between patient survival, propensity to metastasize and specific subtypes of pulmonary adenocarcinomas as determined by ultrastructural examination. Previous electron microscopic studies of pulmonary adenocarcinomas have demonstrated proliferations of three types of cells: mucus, Clara, and alveolar cells. Specific ultrastructural markers of these cell types were assessed in the 34 cases. All cases in this study had a light microscopic diagnosis of adenocarcinoma originating in the pulmonary parenchyma and a follow-up of at least one year. Features such as patient survival time, extent of metastatic involvement, response to therapy, and overall tumor behavior were compared in reference to the cell of origin, in an effort to try to elucidate if such ultrastructural subclassification lent itself to any clinical correlations. Light microscopic growth patterns and special stains were not found to distinguish these neoplasms histogenetically, emphasizing the important role of electron microscopy for an accurate classification.

Adenocarcinoma↗
PubMed1999

Ultrastructural localization of Hsp-72 examined with a new polyclonal antibody raised against the truncated variable domain of the heat shock protein.

In spite of the intensive search for the determination of the continuously widening physiological and pathological roles of different stress proteins, their ultrastructural localization at the electron microscopic (EM) level has hardly been examined. As it becomes increasingly evident that the function and physiological effectiveness of stress proteins are highly dependent on their spatial location and their associations with diverse regulator proteins, the demand for morphological studies which can identify their detailed distribution within the cells is evident. The reason for the practical lack of studies carried out at the EM level, lies in the shortage of reagents with suitable specificity and avidity necessary for this type of examination. To create such a reagent, a polyclonal antibody was raised using a recombinant truncated form of the inducible Hsp-72 protein. The antibody was extensively characterized, using different immunochemical methods to determine and verify its specificity, and then it was tried in ultrastructural examinations. Using the new antibody, it was possible to analyze the intracellular distribution of Hsp-72 with the immunogold technique. The localization of Hsp-72 was demonstrated directly at the ultrastructural level in the cytoplasm (especially at the cisterns of the RER), in the nucleus (mainly around the heterochromatic regions) and at both sides of the nuclear envelope close to the membrane pores. Apart from these localizations, Hsp-72 was found in several membrane bordered intracellular structures, which mainly belong to the endosomal-lysosomal system. We provide the first morphological verification of the appearance of Hsp-72 on the surface of the cells. Also novel is the indication, that the stress protein may recycle from the cell surface using a common route which includes coated pits and the endosomal system.

3T3 Cells↗
PubMed1998

Histochemical and ultrastructural study of skeletal muscle in patients with sepsis and multiple organ failure syndrome (MOFS).

Muscle biopsies for histochemical and ultrastructural analysis were obtained from seven critically ill patients admitted to the Intensive Care Unit of the "Domingo Luciani" Hospital, Caracas, Venezuela. The sample included two patients with sepsis of abdominal origin, and five that presented sepsis/MOFS, with renal, hepatic, and respiratory disturbances and muscular weakness. Sections were examined for myosin adenosine triphosphatase (ATPase) after pre-incubation with both acid buffer (pH 4.37 and 4.6) and alkaline buffer (pH 10.3), for reduced nicotinamide dinucleotide diaphorase (NADHd), and for alpha-glycerophosphate dehydrogenase (alpha-GPDH). Sections were stained with hematoxilin and eosin to look for pathological changes and examined with a transmission electron microscope. Skeletal muscle of patients in early stage of sepsis showed a normal aspect with light microscopy, but at the ultrastructural level some of the fibres showed atrophy and some capillaries looked altered. Patients with sepsis/MOFS exhibited an evident muscle disorder with oedema, infiltrate, atrophy and segmental necrosis. All fibre types showed decrease in diameter; specially fibre types IIA and IIB. Intramuscular capillaries were thickened and occluded, indexes of capillarity were slightly reduced, and fibre oxidative activity was decreased. At ultrastructural level fibres showed severe atrophy, contractile system disorganization and segmental necrosis. Capillaries were also altered and the mononuclear cell infiltrate was abundant and represented by macrophages, lymphocytes and mastocytes.

Adolescent↗
PubMed2000

Ultrastructural features of the gut in the white sturgeon, Acipenser transmontanus.

Electron-microscopic examinations of the sturgeon gut were performed. Oesophageal goblet cells were abundant in the stratified epithelium. The ultrastructural features of the secretory granules of the oesophageal and intestinal goblet cells were quite similar to those of other vertebrates. Lobules of multilocular adipose tissue were observed in the deep tunica propriasubmucosa of the oesophagus, in close association with vasculature and large fibre bundles of myelinated and unmyelinated axons. Similarly composed nerve fibre bundles were observed in the cardiac stomach, too. The presence of myelinated axons is an unusual feature in the vertebrate enteric nervous system. Cardiac and fundic zones of the stomach showed an epithelium with columnar ciliated and non-ciliated cells, the latter equipped with fuzzy microvilli. Cells lining the tubular gastric proper glands were markedly granulated. Intestinal superficial epithelium was columnar and contained ciliated, as well as non-ciliated and goblet cells. In the tunica propria all over the intestine, the presence and ultrastructure of granulated cells was in addition described. Intraepithelial granulated leukocytes were seen throughout the alimentary canal. Various types of endocrine cells were seen both in the stomach and in the intestine, the size of their granules was measured and their ultrastructure described and compared to that of mammalian cell types.

Animals↗
PubMed2002

Chronic hypoxia induced ultrastructural changes in the rat adrenal zona glomerulosa.

The adrenal cortex plays an important role in adaptation to various forms of stress, including hypoxia. While physiological changes in the aldosterone metabolism during hypoxia have been extensively described, few studies have focused on the morphological changes in the adrenal glands under chronic hypoxia. We studied the ultrastructure of the zona glomerulosa of 6-month-old Wistar rats exposed to chronic normobaric hypoxia. Animals were divided into two groups: control (n=12) and hypoxic (n=12). In this latter group, the animals were kept at 7% O2 concentration after a gradual adaptation (21, 15, 12, 10, 8, 7 vol% O2). The duration of the study was 112 days. In comparison with normoxic rats, body weight and adrenal gland weight of hypoxic animals was significantly reduced by 18.5% (p=0.006) and 14.7% (p=0.001) respectively. The thickness of the zona glomerulosa decreased due to atrophy of cells. The main ultrastructural changes observed were: 1) a decrease in, or complete elimination of, lipid droplet content; 2) a marked increase in lysosome number; and 3) the presence of giant mitochondria. Our findings show that rats fail to adapt to severe chronic hypoxia. The ultrastructural changes in the zona glomerulosa found in the present study could reflect changes in the aldosterone pathway.

Adrenal Glands↗
PubMed2004

Ultrastructural localization of integrin subunits alpha3 and alpha6 in capillarized sinusoids of the human cirrhotic liver.

Normal liver sinusoids are not lined by a basement membrane (BM). In contrast, in the course of development of liver cirrhosis, a structured BM is formed de novo in the space of Disse. This BM contributes to the inhibition of the metabolic function of the liver but the pathogenic background of the formation of this perisinusoidal BM is still unclear. Integrins of the beta1-class are generally essential for BM stability and some of them (such as alpha2beta1, alpha3beta1 and alpha6beta1) appear de novo in the perisinusoidal space of the cirrhotic liver. Their cellular distribution in capillarized sinusoids as well as the correlation between their cellular distribution and the formation of the microvascular BM in the cirrhotic liver has not been shown at the ultrastructural level. In the present work we aimed to clarify this issue. We focused on integrins alpha3beta1 and alpha6beta1 and localised them ultrastructurally in human cirrhotic liver microvessels using postembedding immunogold which allows the ultrastructural localization of antigens with high resolution in the tissue. The newly formed basement membrane of capillarized sinusoids was visualized by means of fixation with addition of tannic acid, which enables the visualization of structures of the extracellular matrix with the highest resolution. Also, we carried out laminin detection using postembedding immunogold. Our results show that both alpha3beta1 and alpha6beta1 are expressed on the surface of both hepatocytes and endothelial cells, i.e. on both sides of the newly formed basement membrane. This latter shows zones of higher density both in close proximity to the endothelial and to the hepatocytic surfaces which resemble laminae densae. We propose that hepatocytes and endothelial cells may, therefore, by expressing such integrins, contribute to the formation of this pathological BM in the microvessels of the human cirrhotic liver. On stellate cells, which are major producers of BM components, both integrins alpha3beta1 and alpha6beta1 were also localized.

Basement Membrane↗
PubMed1975

Changes in ultrastructure of rat ovaries after early postnatal x-ray irradiation.

Female rate were irradiated with 190R of X-rays at 10 days of age and ovarian ultrastructures were studied 4 and 7 months after irradiation. Ultrastructural changes were found in germinal epithelial cells, fibroblasts in the tunica albuginea and interstitial cells. The germinal epithelial cells exhibited various signs of degeneration but no sign of proliferation. Electron density of their basal part was reduced considerably. Their mitochondria became swollen and free ribosomes decreased in number. The nuclei often protruded from the free surface of these cells. These cells frequently fragmented and,finally, the complete desquamation occurred. The basement membrane became unevently thickened. Nuclei of enlarged fibroblasts in the tunica albuginea became irregular ellipsoid in shape, and the nuclear envelope was occasionally invaginated. Various cytoplasmic organelles of the fibroblasts were well-developed. Some abnormal invasion of cytoplasm into the nucleus was found in the interstitial cells showing the ultrastructural characteristics of steroid hormone synthesis. Various cytoplasmic organelles and inclusions invaded into the nucleus of these cells and the nuclear envelope sometimes disappeared locally. These interstitial cells contained a large number of irregular-shaped electron dense mitochondria with vesicular cristae, and numerous dilated vesicles of smooth-surfacedendoplasmic reticulum (SER). The cells of anovular follicles in the irradiated ovariesresembled, in fine structure, the granulosa cells in normal primary follicles of the non-irradiated ovaries. These cells seem to be less affected by early postnatal irradiation.

Animals↗
PubMed1994

Effect of cryopreservation on development and ultrastructure of preimplantation embryos from the dasyurid marsupial Sminthopsis crassicaudata.

The effect of different cryopreservation methods on the development and ultrastructure of preimplantation embryos of Sminthopsis crassicaudata, a small carnivorous marsupial and member of the family Dasyuridae, was investigated. Females were primed with 1 iu pregnant mares' serum gonadotrophin to induce oestrus and ovulation. Mating generally ensued and, approximately 6 days after priming, embryos were collected and cultured in 5% CO2 in air at 35 degrees C for 18-22 h in either Dulbecco's modified Eagles medium (DMEM) with high glucose or human tubal fluid medium (HTF), both supplemented with 10% fetal calf serum. Cleavage rates were higher in DMEM than in HTF. One slow and two ultrarapid freezing methods were used. Two out of 12 (17%) embryos cleaved in culture after freezing and thawing using the slow regimen, compared with six of 16 (38%) non-frozen controls. In addition, two of 11 (18%) embryos cleaved in culture following ultrarapid freezing and thawing by one of the two methods, compared to 31 of 41 (76%) non-frozen controls. Most of the embryos appeared morphologically normal under the light microscope after freezing and thawing by the slow regimen, but considerable variation in the degree of ultrastructural damage to the cellular organelles was evident with the transmission electron microscope. The rather low rate of cleavage after freezing and thawing was probably due, at least in part, to ultrastructural damage of the cells.

Animals↗
PubMed1995

Ultrastructure of the dorsal skins of hairless descendants derived from Mexican hairless dogs.

Ultrastructural characteristics of the dorsal skin of hairless descendants derived from Mexican hairless dogs (3-month-, 1-year- and 5-year-old) were investigated and compared with those of age-matched beagles. Except that beagles had no melanocytes in epidermis, there was no essential difference in ultrastructural characteristics of epidermis between hairless dogs and beagles. In the Stratum basale of epidermis of hairless dogs, a small number of melanocytes and a few Langerhans cell (LC)-like cells were observed among keratinocytes. Melanocytes contained many melanosomes and a few premelanosomes. LC-like cells were characterized by electron-lucent cytoplasm and lobulated nucleus and lacked melanin granules, tonofilaments and desmosomal attachments. Unlike LC in humans and rodents, these LC-like cells did not contain Birbeck granules. Although age-related ultrastructural changes of dorsal skin were generally not clear both in hairless dogs and in beagles, cells containing melanin granules were not infrequently observed among dermal collagen bundles in 5-year-old hairless dogs.

Animals↗
PubMed1981

[The effects of zinc on cadmium-induced ultrastructural changes in rat livers (author's transl)].

The superimposed effects of oral zinc administration on cadmium-induced ultrastructural changes in rat livers were studied. Twenty female rats were divided into 4 groups. To the diet for group I was added 200 ppm Cd for daily about 10 g diet, to that for group II 200 ppm of Zn and that for group III 200 ppm of Cd and Zn each. The group IV was the control. All of the four groups was sacrificed after 9 months of administration. In addition to examine the liver by an electron-microscope, Cd concentration in the liver was analyzed by atomic absorption spectrophotometry. The Cd contents in the livers of group III were significantly reduced compared with those of group I. Apparent ultrastructural changes; i.e., deterioration of rough endoplasmic reticula, losses of glycogen particles, and proliferation of smooth endoplasmic reticula, were observed in the livers of group I. Meanwhile, these changes were significantly mild in those of group III. From these results, it is suggested that Cd inhibits protein synthesis and glycogen metabolism in the liver and that Zn partly protects the liver from Cd-induced ultrastructural changes.

Animals↗
PubMed1987

[Ultrastructural study of conjunctival biopsies in metabolic diseases of the nervous system].

Forty conjunctival biopsies from children suffering from metabolic diseases of the CNS were studied ultrastructurally. In 20 cases they were abnormal (8 mucopolysaccharidosis, 6 GM1 gangliosidosis, 4 infantile neuroaxonal dystrophy, 1 GM2 gangliosidosis, 1 late infantile ceroid lipofuscinosis). In the 20 remaining cases the biopsies did not show abnormalities. From these, 2 were proven as Leigh disease and Hallervorden-Spatz disease in which there is no conjunctival ultrastructural alterations; in 2 cases (one metachromatic leukodystrophy and one adrenoleukodystrophy) the results were false negative); in 4 clinically suspected cases of late infantile ceroid lipofuscinosis no alterations were observed and the results were not conclusive. In the remaining 12 cases the negatives allowed to rule out lysosomal disorders. The ultrastructural study of the conjunctival biopsy is an important tool for the diagnosis of neurological metabolic diseases of children mainly when sophisticated biochemical procedures are not available.

Biopsy↗
PubMedDate not supplied

Chronic murine myocarditis due to Trypanosoma cruzi--an ultrastructural study and immunochemical characterization of cardiac interstitial matrix.

In an attempt to define the mouse-model for chronic Chagas' disease, a serological, histopathological and ultrastructural study as well as immunotyping of myocardium collagenic matrix were performed on Swiss mice, chronically infected with Trypanosoma cruzi strains: 21 SF and Mambaí (Type II); PMN and Bolivia (Type III), spontaneously surviving after 154 to 468 days of infection. Haemagglutination and indirect immunofluorescence tests showed high titres of specific antibodies. The ultrastructural study disclosed the cellular constitution of the inflammatory infiltrate showing the predominance of monocytes, macrophages with intense phagocytic activity, fibroblasts, myofibroblasts and abundant collagen matrix suggesting the association of the inflammatory process with fibrogenesis in chronic chagasic cardiomyopathy. Arteriolar and blood capillary alterations together with dissociation of cardiac cells from the capillary wall by edema and inflammation were related to ultrastructural lesions of myocardial cells. Rupture of parasitized cardiac myocells contribute to intensify the inflammatory process in focal areas. Collagen immunotyping showed the predominance of Types III and IV collagen. Collagen degradation and phagocytosis were present suggesting a reversibility of the fibrous process. The mouse model seems to be valuable in the study of the pathogenetic mechanisms in Chagas cardiomyopathy, providing that T. cruzi strains of low virulence and high pathogenicity are used.

Animals↗
PubMed2002

Ultrastructural alterations in adult Schistosoma mansoni caused by artemether.

Progress has been made over the last decade with the development and clinical use of artemether as an agent against major human schistosome parasites. The tegument has been identified as a key target of artemether, implying detailed studies on ultrastructural damage induced by this compound. We performed a temporal examination, employing a transmission electron microscope to assess the pattern and extent of ultrastructural alterations in adult Schistosoma mansoni harboured in mice treated with a single dose of 400 mg/kg artemether. Eight hours post-treatment, damage to the tegument and subtegumental structures was seen. Tegumental alterations reached a peak 3 days after treatment and were characterized by swelling, fusion of distal cytoplasma, focal lysis of the tegumental matrix and vacuolisation. Tubercles and sensory organelles frequently degenerated or collapsed. Typical features of subtegumental alterations, including muscle fibres, syncytium and parenchyma tissues, were focal or extensive lysis, vacuolisation and degeneration of mitochondria. Severe alterations were also observed in gut epithelial cells and vitelline cells of female worms. Our findings of artemether-induced ultrastructural alterations in adult S. mansoni confirm previous results obtained with juvenile S. mansoni and S. japonicum of different ages.

Animals↗
PubMed2005

Ultrastructure of spermiogenesis and the spermatozoon of Macracanthorhynchus hirudinaceus (Pallas, 1781) (Acanthocephala: Archiacanthocephala), a parasite of the wild boar Sus scrofa.

The present paper describes the ultrastructure of spermiogenesis and the spermatozoon of Macracanthorhynchus hirudinaceus, an acanthocephalan parasite of the wild boar Sus scrofa. At the beginning of spermatogenesis, spermatocytes exhibit synaptonemal complexes and 2 centrioles. In the spermatid, only 1 centriole remains, generating a flagellum with a 9+2 pattern. Another ultrastructural feature observed during the spermiogenesis of M. hirudinaceus is the condensation of the chromatin, forming a "honeycomb" structure in the old spermatid and a homogeneous, electron-dense structure in the spermatozoon. The mature spermatozoon of M. hirudinaceus presents a reversed anatomy, as has been described previously in other species of the Acanthocephala. The spermatozoon is divided into 2 parts: an axoneme, and a nucleocytoplasmic derivative. The spermatozoon flagellum exhibits a 9+2 or 9+0 pattern. The process of spermiogenesis and the ultrastructural organization of the spermatozoon of M. hirudinaceus are compared with available data regarding other acanthocephalan species.

Acanthocephala↗