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At least 1,531 records · Page 85Linked to original sources
PubMed2001

[Granulosa cell tumors: structural and ultrastructural analysis].

UNLABELLED: These ovarian neoplasm derive from the ovarian stromal component constituting around the 5 to 12% of all ovarian tumors. OBJECTIVE: To examine the histopathological and ultrastructural morphologic characteristic of the neoplastic cells and the patognomonic element of these tumors: Call Exner's Bodies MATERIALS AND METHODS: The materials corresponded to 2 women of 52 and 55 years. The syntomatology was abdominal tumor that went in increase. The materials were fractioned for the histopathological conventional study and for ultrastructural analysis. For this last one, they were fixed in Karnovsky, refix in osmio and included in Araldita. RESULTS: By means of the different observations it was determined in both cases the nuclear atipia, indentations nuclei and prominent nucleoli. In one of the cases the presence of Bodies of Call-Exner was detected, and ultrastructurally was compound by whirled fibrils and amorphous material, with dense structures electron to its around. It was interest the infiltrated of plasmatic cells around the tumors cells. These neoplasms are of interest due to their impredictible behavior and to the hormonal production that can originate alterations in other organs of the genital apparatus.

Female↗
PubMed1992

[A clinical and ultrastructural study of Fechtner syndrome in two Japanese families].

This is a report of Fechtner syndrome in two Japanese families. Six members of family I and three members of family II were studied. All but one had macrothrombocytopenia and leukocyte inclusion bodies, four had deafness, four had persistent proteinuria and none had cataracts. Under a diagnosis of ITP, two of them had splenectomy which resulted in no response. History revealed, other family members with deafness and/or nephritis were confirmed in both families. Ultrastructural studies of leukocytes showed oval inclusion bodies with unclear borders containing many fine ribosome like granules and randomly scattered filaments. Ultrastructural studies of macrothrombocytes were unremarkable except for a well-developed open canalicular system. More than half of megakaryocytes had uneven basophilic speckles in the cytoplasm, which were positive for Unna-Pappenheim staining. Ultrastructurally, widening of demarcating systems and remaining ribosomes were noted in the cytoplasma of mature megakaryocytes.

Deafness↗
PubMed1992

Ultrastructural study of experimental myocarditis induced by cardiovirus (EMCV-M) in swine.

Eight 6-week-old piglets were inoculated with a strain of encephalomyocarditis virus (EMCV) isolated from an outbreak which occurred naturally in the Po Valley in 1988. Two non-infected animals, kept in the same cage, were used as controls. Out of the eight inoculated piglets, two died and two were suppressed on the 2nd post infection day (PID), the four remaining were killed on the 5th, 7th, 11th and 15th PIDs. Control animals were killed at the end of the experiment. The pathogenesis of myocarditis has been studied using routine methods (Alcian-PAS, Masson's trichrome, Gomori's for reticulin and Mallory's stain), histochemical techniques (ATPase and NADH-TR reactions) and ultrastructural observations (TEM). All the inoculated piglets showed macro and/or microscopic lesions of lymphocytic myocarditis, only in one case associated with fibrinous exudation. One control piglet also showed myocarditic lesions, probably due to a contact infection. An early myocardial fibrosis was already present on the 5th PID. Ultrastructurally the cardiac muscle cells showed severe myofibrillar losses and other regressive alterations. Only on the 15th PID did we observe calcification of the degenerating myocytes, while ultrastructurally we detected needle-like calcium deposits in the mitochondria from the 5th PID. From the 5th PID in the areas of myocarditis the myocytes showed a reduction and/or absence of ATPase and NADH-TR reactions. On TEM, one or more aggregates of viral particles in crystalline array were detected in the cytoplasm of many endothelial cells.

Adenine↗
PubMedDate not supplied

Immuno-lectin histochemistry and ultrastructure in two cases of globoid cell leukodystrophy (Krabbe's disease).

Two cases of globoid cell leukodystrophy (Krabbe's disease) have been studied by means of conventional histological, immunohistochemical and ultrastructural methods. Lectins specific for several different carbohydrates, Ricinus communis (RCA-1), peanut agglutinin (PNA), wheat germ agglutinin (WGA) and Concanavalin A (Con A) have been utilized both at optical and ultrastructural level. In both cases a strong positive labeling of the globoid cells could be observed light-microscopically. Ultrastructurally immunogold deposits only of RCA-I and WGA in the typical Krabbe's inclusions have been clearly demonstrated.

Acetylgalactosamine↗
PubMed1992

A preliminary study of correlation of immuno-histological and ultrastructural characteristics of neural granuloma in leprosy patients.

With an aim to better understand the pathogenesis of nerve damage in leprosy, peripheral nerve biopsies from six untreated leprosy cases (3 BT/TT and 3 BL/LL) were studied by electronmicroscopy and immuno-histology. In addition to routine histopathology for diagnosis, infiltrating cells of granuloma were characterized after preparation of single cell suspension. The lymphocytes in the lesion were characterized by E and EAC rosetting and macrophage phagocytic system (MPS) cells were studied using histochemical markers like esterase and peroxidase. The results indicate that the lymphocyte content was significantly greater in tuberculoid neural granuloma compared to lepromatous nerves and these formed rosettes with sheep erythrocytes (E) and expressed HLA-DR antigen suggesting that they are activated T cells. Infiltrating macrophages in both the tuberculoid and lepromatous neural granuloma were esterase positive, peroxidase negative and did not form rosettes with sheep erythrocytes or EAC. Ultrathin sections of tuberculoid granuloma showed lymphocytes clearly associated to epithelioid macrophages having well developed Golgi apparatus and rough endoplasmic reticulum. Correlation of these immunological and ultrastructural characters suggests that hypersensitivity mechanisms are possibly responsible for nerve damage in tuberculoid leprosy. Ultrastructural examination of lepromatous nerves, on the other hand, showed the predominance of macrophages with large nucleus, heavily bacillated Schwann cells, and a few lymphocytes. The correlation of immuno-histological and ultrastructural characters indicates that the mechanism(s) of nerve damage in lepromatous leprosy are basically different wherein hypersensitivity appears to play a very limited role.

Academies and Institutes↗
PubMedDate not supplied

The ultrastructure of fresh and cultured cells in fifteen soft tissue and bone tumors.

Cultured cells from 15 soft tissue and bone tumors and surgical specimens from 14 of these were studied by electron microscopy. The cells, cultured for one to five weeks, maintained ultrastructural features similar to those found in the fresh tumor tissue. The ultrastructural characteristics of the cultured cells were distinct enough for diagnostic purposes. Short-term cultures from all tumors were subjected to cytogenetic analysis. Clonal chromosome aberrations were found in 11 of the tumors and normal karyotypes in the remaining four. Ultrastructural analysis of cultured cells can be used for cell type identification and tumor classification.

Adolescent↗
PubMed1992

[Ultrastructure of amitosis and mitosis of the liver].

Thousands of liver cells of several ultrastructural investigation programs of our laboratory have been evaluated in respect to amitosis and mitosis. Multiplication of hepatocytes by amitosis and mitosis often leads to bi-, tri- and multinucleated cells. No striking ultrastructural changes have been observed in the hepatocytes of human and animal livers. There are no indications of enhanced autophagocytosis or other signs of dedifferentiation. However, non-hepatocytes suffer ultrastructural changes during mitosis: endothelial cells reduce their organelles in number, round up their shape and form microvilli reaching between the microvilli of hepatocytic sinusoidal membrane. Mitotic Kupffer cells contain only small phagosomes and are separated from hepatocytes by endothelial cell processes.

Animals↗
PubMedDate not supplied

Ultrastructure of pinealocytes in mice implanted with Colon 38 adenocarcinoma.

OBJECTIVES: Relationship between the pineal gland and neoplastic disease has been repeatedly shown in many both experimental and clinical studies. However, morphological studies of the pineal gland in animals with experimentally-induced tumors are rare. Therefore, we decided to investigate the ultrastructure of pinealocytes in mice with implanted Colon 38 adenocarcinoma. MATERIAL AND METHODS: Male adult B6D2F1 mice were used in this study. The animals were divided into two groups. Eight mice were subcutaneously implanted with Colon 38 cell suspension, whereas the other eight intact animals served as controls. Three weeks after tumor implantation four animals from each group were sacrificed by spinal cord dislocation at 12:00 h or 24:00 h. The pineal glands were removed and processed for electron microscopic studies. The cross-sectional areas of the pinealocyte and its nucleus, and relative volume of mitochondria, Golgi apparatus, lysosomes, granular endoplasmic reticulum, and lipid droplets, as well as the number of dense-core vesicles were estimated using a digital analyzer connected on-line to IBM-PC computer. Statistical analysis of the data was performed using Student's t-test and Snedecor F test. RESULTS: In the pineal glands of the tumor-bearing animals killed during the daytime diminished size of pinealocytes and their nuclei, decreased relative volume of granular endoplasmic reticulum, lysosomes, and lipid droplets as well as decreased number of dense-core vesicles were observed. On the contrary, the relative volumes of mitochondria and Golgi apparatus were increased in these animals. In the tumor-bearing animals killed at night, however, increased cross-sectional areas of pinealocytes, and decreased number of dense-core vesicles were observed. CONCLUSIONS: The results of our study suggest that the presence of the malignant tumor influences the morphology of pineal cells in mice. Considering the fact that different patterns of ultrastructural changes were demonstrated in pinealocytes in different tumor types in various species, it seems that the character of the ultrastructural changes observed in tumor-bearing animals depends on the animal species and tumor type.

Adenocarcinoma↗
PubMed2003

Ultrastructural changes in the remnant kidney (after 5/6 nephrectomy) glomerulus after losartan and atenolol treatment.

The aim of our study was to investigate the effect of losartan on the changes in the early stages (at week 4) of experimental chronic renal failure after 5/6 nephrectomy compared with the impact of atenolol. Attention was focused on the ultrastructural changes in the renal corpuscles. Twenty-seven male Wistar rats were divided into three groups: nephrectomized group, nephrectomized losartan-treated group and nephrectomized atenolol-treated group. Rats were kept in a climate-controlled facility, where animals were housed under standard conditions on a 12-hour light/dark cycle and fed with standard rodent chow. Angiotensin receptor antagonist losartan (180 mg/L) or beta-blocking agent atenolol (750 mg/L) was added to the drinking water and treatment was started on the first day after the operation. Systolic blood pressure and 24 hour protein excretion was measured every week. Nephrectomized rats had higher proteinuria and systolic blood pressure than the treated rats. Rats were killed 4 weeks after surgery. Early stage renal disease was characterized by glomerular hypertrophy and focal segmental glomerulosclerosis. The morphological study revealed that ultrastructural changes in the atenolol-treated group were smaller than those in the nephrectomized and losartan-treated groups. Glomerular basement membrane (GBM) thickness was significantly increased in losartan-treated (206.8 nm) and atenolol-treated (198.8 nm) rats compared to nephrectomized (169.2 nm) rats. The podocytes demonstrated hypertrophy and foot process effacement, especially in nephrectomized group. In conclusion, our results show that firstly, treatment with losartan and atenolol significantly increased GBM thickening and secondly, treatment with atenolol reduced ultrastructural changes in the podocytes.

Adrenergic beta-Antagonists↗
PubMed2003

Effect of mannitol in experimental spinal cord injury: an ultrastructural and electrophysiological study.

BACKGROUND: Although many experimental and clinical studies were performed on the pathophysiology and treatment of spinal cord injury (SCI), the electrophysiological and ultrastructural changes of the spinal cord were not precisely evaluated. AIMS: To investigate the effect of mannitol on Somatosensory Evoked Potentials (SSEP), postoperative neurological recovery and ultrastructural findings after an experimental SCI. SETTING: The experimental microsurgery laboratory of a university hospital. DESIGN: A prospective, randomized animal study. MATERIAL AND METHODS: Sprague-Dawley rats were used and divided into three groups (Groups I-III) for this study. Those in Group I were control animals who underwent laminectomy only, and non-traumatized spinal cord samples were obtained 2 weeks later. SCI was produced in Groups II and III using clip compression technique, and cord samples were obtained 2 weeks later. The rats in Group II received 2 g/kg of 20% mannitol intraperitoneally, immediately and three hours after trauma was induced; and those in Group III received the same amount of 0,9% NaCl in the same manner. Preoperative and postoperative SSEP records at the end of 2 weeks were obtained. Electron microscopy examination of the cord samples was done at 2 weeks postoperatively. STATISTICAL ANALYSIS USED: Fischer's Exact Test. RESULTS: SSEP records, ultrastructural findings and clinical recovery showed that minor neural damage and significant recovery occurred in Group II. CONCLUSION: This study demonstrates that the administration of 2 g/kg of 20% mannitol produces significant improvement in the neural structures and protects the spinal cord following injury.

Animals↗
PubMed2003

[Effects of sunlight and temperature on ultrastructure and functions of chloroplast of cucumber in solar greenhouse].

Studies on the effects of sunlight and temperature on the ultrastructure and functions of leaf chloroplasts of cucumber (Cucumis sativus L.) in solar greenhouse showed that the size of cells, chloroplasts, and starch grains and the number of chloroplast, grana, grana lamella and grana thickness of leaf chloroplast of cucumber increased with lowering leaf position. The microstructure of leaves and the ultrastructure of chloroplast of cucumber leaves were different because of the difference of temperature and sunlight among different months. In January, the light intensity was lower, and the cell size of cucumber leaves was larger than that in May, but the number of chloroplasts was less than that in May. The relationships between photosynthetic rate (Pn) and ultrastructure of chloroplast of cucumber leaves were not direct and very close. The Pn of the fourth leaf of cucumber was the highest, that of the first spreading out leaf was the second, and the near ground leaves had the lowest Pn. The primary reasons of the difference of Pn among different position leaves were that the leaf age and accepted light intensity were different. If different position leaves of cucumber accepted the same sunlight intensity, the difference of Pn among leaves of different positions would be smaller. Less efficient light hours and lower light intensity were the main factors influencing cucumber growth and yield in solar greenhouse. Comparatively, under sunny circumstance, the restriction of temperature on cucumber growth was very small, but in cloudy days, lower temperature induced by low light intensity became a key factor that restricted cucumber growth.

Chloroplasts↗
PubMed2003

Ultrastructural determinants of murine achilles tendon strength during healing.

The mechanisms by which tendon strength is established during growth and development and restored following injury are not completely understood and are likely to be complex, multifactorial processes. Several studies examining the relationship between mechanical behavior and ultrastructural characteristics of tendons and ligaments during growth and maturation suggest that collagen fibril diameter is strongly correlated with tendon strength. Because of the similarities between development and repair processes of musculoskeletal tissues, increases in tendon strength during healing may be related to increases in fibril ultrastructural parameters such as fibril size, numerical density, and area fraction. In this study, we compared murine Achilles tendons at various time points after tenotomy with sham-operated controls in tensile tests to failure and examined tendons using electron microscopy to assess collagen fibril ultrastructure. We found that in the 6-week period following Achilles tenotomy, fibril mean diameter remained significantly smaller than sham-side diameter by a factor of 2-3. Despite the persistently small fibril size, increasing numerical density resulted in a gradual increase in fibril area fraction. Biomechanical strength did not reach that of intact tendons until some time between 5 and 7 weeks, approximately the same time period when fibril area fraction began to approach sham values. These data suggest that parameters other than collagen fibril size are most responsible for increased tendon strength during healing.

Achilles Tendon↗
PubMedDate not supplied

Cytochemical and ultrastructural changes in the osteoclast-like giant cells of giant cell tumor of bone following bisphosphonate administration.

Giant cell tumor of bone (GCT) is a local aggressive neoplasm of bone characterized by expansive osteolytic lesions at the epiphysis of long bones. Bisphosphonates have been used to prevent bone resorption in secondary osteolytic tumors because of their strong anti-osteoclastic action. The authors studied the apoptosis and ultrastructural changes induced in osteoclast-like giant cells of GCT, following treatment with the aminobisphosphonate pamidronate in 16 patients with GCT of bone. Transmission electron microscopy (TEM) was used to identify ultrastructural changes, indicative of apoptosis, in the cytoplasm and the nucleus of the giant cells. Significant changes were observed in tumor samples from all 16 patients. In the cytoplasm these changes were characterized by abundant large tubular vesicles containing a central electrodense core scattered through the cytoplasm. In addition, mitochondria in the sections from pamidronate-treated patients appeared to be edematous when compared with sections from untreated patients. Nuclear changes in the giants cells were characterized by the formation of dense chromatin material scattered throughout the nucleus. The TUNEL labeling assay indicated that the mean pretreatment apoptotic index of 7.8% increased to 53% following pamidronate treatment. This was statistically significant (p<.001) and correlated well with the ultrastructural changes noted on TEM. The formation of abundant tubular vesicles in giant cells following bisphosphonate treatment may reflect disturbed vesicular trafficking and may affect the bone resorbing activity of giant cells.

Apoptosis↗
PubMed1992

An ultrastructural analysis of tumor-promoting phorbol diester-induced degranulation of human basophils.

Release reactions stimulated in human basophils by a variety of secretagogues show biochemical and morphologic differences as well as similarities. Biochemical differences include those of rate, amount, and order of mediator release, as well as mediator type released or generated. Morphologic diversity of release reactions includes prototypic anaphylactic degranulation (AND), or piecemeal degranulation (PMD), and a continuum of anatomic release comprised of PMD followed by AND that is seen when human basophils are stimulated by the bacterial peptide, formyl methionyl leucyl phenylalanine (FMLP). AND is characterized by extrusion of membrane-free granules through multiple plasma membrane pores; PMD is characterized by partially to completely empty, nonfused granule containers in the cytoplasm of basophils. AND is further characterized by diminished-to-absent granules and reduced cytoplasmic vesicles at peak histamine release intervals; PMD does not show decreases in numbers of granules, and cytoplasmic vesicles are plentiful. Smooth membrane-bound vesicles with granule particles and vesicles that appear empty comprise this organelle population. PMD is the single most evident activation change present in basophils that traffic into tissues in multiple diseases in vivo. In this study, we examined the ultrastructural kinetic morphology associated with stimulation of human basophils with tetradecanoyl phorbol acetate (TPA)--a tumor-promoting phorbol diester known to elicit histamine (but not LTC4) release. Partially purified human basophils were prepared for electron microscopy and examined either after control incubations in buffer alone or at 0 time, 1, 2, 5, 10, 30, and 45 minutes after TPA stimulation. Standard morphology and ultrastructural quantitation of vesicles and granules and contents of vesicles or alteration of granules was done and compared with previous ultrastructural kinetic analyses of human basophil release reactions stimulated by different triggers. Like biochemical studies that have determined that TPA is a unique secretogogue for human basophils, the morphology stimulated by TPA and associated with histamine release was also unique. For example, very minor images of AND were evident. Far greater amounts of PMD were imaged. PMD was associated with approximately 50% alteration of cytoplasmic granules by 45 minutes after TPA stimulation. This evidence of empty granules was associated with, and preceded by, a rapid, extensive, and sustained increase in particle-containing cytoplasmic vesicles, as compared with buffer controls (P < 0.001 for each TPA stimulation time compared with unstimulated basophils). In addition, previously undescribed interactions of releasing granules and their overlying plasma membranes characterized TPA-stimulated cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Basophils↗
PubMed2003

[Ultrastructural changes of the skeletal muscle cells of rats subjected to exhausting exercises and the protective effect of vitamin E].

OBJECTIVE: To investigate the ultrastructural changes of the mitochondria in the skeletal muscle cells of rats subjected to repeated exhausting exercises on treadmill and the protective effect of oral vitamin E. METHODS: Thirty male SD rats were randomized into control group (n=10), exhausting exercise group (n=10) and exhausting exercise group with oral vitamin E treatment (n=10), with the latter two groups taking repeated exhausting running exercises on the treadmill in a course of 4 weeks. At the end of the course of exercises, the rats were sacrificed and the quadriceps femoris muscles isolated for observation the ultrastructures of the skeletal muscle cells by transmission electron microscope (TEM). RESULTS: After 4-week exhausting exercises, the myofilaments of the skeletal muscle were seen in disordered alignment, and the mitochondria exhibited abnormal morphological changes of swelling and vacuolar degeneration. In vitamin E-treated rats also undertaking the exercise, the ultrastructures of the skeletal muscle cells were almost normal as compared with the normal control group. CONCLUSION: Vitamin E can protect the function of the skeletal muscle mitochondria of rats taking repeated exhausting exercises.

Animals↗
PubMedDate not supplied

Hyalinizing spindle cell tumor with giant rosettes and low-grade fibromyxoid sarcoma: an immunohistochemical and ultrastructural comparative investigation.

Hyalinizing spindle cell tumor with giant rosettes (HSCTGR) and low-grade fibromyxoid sarcoma (LGFMS) are 2 variants of fibrosarcoma, which share several clinicopathologic features. This study compares the light microscopic, immunohistochemical, and ultrastructural features of 2 examples of HSCTGR and 3 of LG FMS to determine the degree of overlap of these 2 tumors. HSCTGR were composed of bland spindle cells within hyalinized to myxoid stroma. Scattered throughout the lesions were characteristic rosette-like structures, formed by a central collagenous core surrounded by spindled neoplastic cells. LGFMS consisted of a mixture of fibrous and myxoid areas, composed of fibroblast-like cells arranged in a swirling, whorled growth pattern. Immunohistochemical analysis showed diffuse positivity for vimentin in all cases, while few scattered tumor cells stained for CD57, CD34, factor XIIIA, and actin. The extracellular matrix showed intense positivity for type IV collagen, laminin, and fibronectin, with the exception of myxoid areas of LGFMS and the central core of the giant rosettes in HSCTGR. Ultrastructurally, both tumor types were composed of cells with the features of fibroblasts, embedded in a collagenous stroma with irregular deposits of amorphous basal lamina-like substance. In conclusion, HSCTGR and LGFMS share similar immunophenotypic and ultrastructural features, and together with other fibrosing fibrosarcomas, like sclerosing epithelioid fibrosarcoma, may constitute a subset of fibrosarcomas formed by fibroblasts capable of producing large amounts of basal lamina-like material.

Adult↗
PubMed2003

[Toxic effects of Cd2+ pollution on the biochemical and physiological characters and ultrastructure of Alternanthera philoxeroides].

By imitating different concentration Cd2+ polluted water environment, this paper dealt with the changes of some biochemical and physiological characters and the damage of ultrastructure in leaves of Alternanthera philoxeroides. The result showed that SOD and POD activity first increased in the low concentration pollution and then decreased with the concentration of pollution raised. The content of chlorophyll, chlorophyll a/b value, CAT activity and the content of soluble protein all declined continually. With the concentration of pollution increased, the ultrastructure of cell nuclei, chloroplast and mitochondria became deformed, the permutation of structure inside disordered, swelled, membrane disrupted and vesiculated. The changes of some biochemical and physiological characters accorded with the damage of cell ultrastructure.

Amaranthaceae↗
PubMed1992

Cytoarchitecture and ultrastructural characteristics of the area octavolateralis of the urodele amphibian Pleurodeles waltlii.

The cytoarchitecture of the area octavolateralis (AOL) in Pleurodeles waltlii is studied by means of normal stained material. In addition, the main ultrastructural features of the cells in the AOL are described. In the AOL, three columns, one upon the other (dorsal, intermediate and ventral), are present. Each one includes a medially located cell group and lateral neuropil. While rostrally the three are well represented, the dorsal subdivision do not reach the same caudal extent where the intermediate column forms a small lobe. The ultrastructure of the neurons in the AOL reveals similarities with other cell types in the amphibian brain. A comparative analysis of the ultrastructure of vestibular cells with other vertebrates is also discussed.

Animals↗