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PubMed1999

The ultrastructure of a compomer adhesive interface in enamel and dentin, and its marginal adaptation under dentinal fluid as compared to that of a composite.

OBJECTIVES: To visualise the ultrastructure of the interface of SCA compomer adhesive and of Optibond composite adhesive in enamel and dentin, and to relate the findings to the marginal adaptation of these two products in mixed class V restorations. METHODS: The ultrastructure was investigated using a scanning electron microscope (SEM) with and without prior argon ion etching, an environmental SEM, a field emission SEM, a confocal laser scanning microscope, and a transmission electron microscope. The marginal adaptation was quantified in mixed class V restorations by using the replica technique and a SEM under simulated dentinal fluid before and after simultaneous mechanical and thermal loading. RESULTS: The ultrastructure of the compomer adhesive interface differed from those of the composite. However, no significant difference was discerned as regards the percentage of "continuous margin" in the enamel marginal area before loading, and in the dentin area before and after loading (p < 0.05; unpaired t-test). Only after loading, the percentage of "continuous margin" in enamel was significantly (p < 0.05; unpaired t-test) better than that of the compomer. SIGNIFICANCE: The results indicated that the ultrastructure of the adhesive interface allowed no clear conclusions to be drawn as to the quality of marginal adaptation.

Compomers↗
PubMedDate not supplied

Protection of hepatocyte mitochondrial ultrastructure and function by strict blood glucose control with insulin in critically ill patients.

BACKGROUND: Maintenance of normoglycaemia by use of insulin reduces morbidity and mortality of patients in surgical intensive care. Studies on mitochondrial function in critical illness or diabetes suggest that effects of intensive insulin therapy on mitochondrial integrity contribute to the clinical benefits. METHODS: Enzyme activities of the respiratory-chain complexes and oxidative-stress-sensitive glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were measured by spectrophotometry in 36 snap-frozen samples of liver and skeletal muscle obtained after death from patients who had been randomly assigned intensive (normoglycaemia) or conventional (hyperglycaemia) insulin therapy and who were similar in terms of admission diagnoses and causes of death. Mitochondrial ultrastructure was examined by electron microscopy in a random subgroup (n=20). FINDINGS: In the liver, hypertrophic mitochondria with an increased number of abnormal and irregular cristae and reduced matrix electron density were observed in seven of nine conventionally treated patients. Only one of 11 patients given intensive insulin treatment had these morphological abnormalities (p=0.005). The effect on ultrastructure was associated with higher activities of respiratory-chain complex I (median 1.53 [IQR 1.14-3.01] vs 0.81 [0.54-1.43] U/g liver; p=0.008) and complex IV (1.69 [1.40-1.97] vs 1.16 [0.97-1.40] U/g; p=0.008) in the intensive group than in the conventional group. There was no detectable difference in GAPDH activity. In skeletal muscle, mitochondrial ultrastructure and function were not affected by intensive insulin therapy. INTERPRETATION: Strict glycaemic control with intensive insulin therapy prevented or reversed ultrastructural and functional abnormalities of hepatocyte mitochondria. The lack of effect on skeletal-muscle mitochondria suggests a direct effect of glucose toxicity and glucose control, rather than of insulin, as the likely explanation. RELEVANCE TO PRACTICE: Maintenance or restoration of mitochondrial function and cellular energetics is another therapeutic target, in addition to optimisation of cardiac output, systemic oxygen delivery, and regional blood flow, that might improve outcome for critically ill patients. Our findings could help to explain the mechanism underlying the reduction in mortality found when normoglycaemia was maintained with insulin, and further support use of intensive insulin therapy in this setting.

APACHE↗
PubMed2000

Development of tailor-made collagen-glycosaminoglycan matrices: EDC/NHS crosslinking, and ultrastructural aspects.

The many biocharacteristics of glycosaminoglycans (GAGs) make them valuable molecules to be incorporated in collagenous biomaterials. To prepare tailor-made collagen-GAG matrices with a well-defined biodegradability and (bioavailable) GAG content, the crosslinking conditions have to be controlled. Additionally, the ultrastructural location of GAGs in engineered substrates should resemble that of the application site. Using chondroitin sulfate (CS) as a model GAG, these aspects were evaluated. The methodology was then applied for other GAGs. CS was covalently attached to collagen using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). A maximum of about 155 mg CS/g matrix could be immobilized. CS incorporation and bioavailability, as evaluated by interaction with specific antibodies and glycosidases, was dependent on the molar ratio EDC:carboxylic groups of CS. The denaturation temperature could be modulated from 61 to 85 degrees C. The general applicability of EDC/NHS for immobilizing GAGs was demonstrated with dermatan sulfate, heparin, and heparan sulfate. These matrices revealed comparable physico-chemical characteristics, biodegradabilities, and preserved bioavailable GAG moieties. At the ultrastructural level, GAGs appeared as discrete, electron-dense filaments, each filament representing a single GAG molecule. Distribution was independent of GAG type. They were observed throughout the matrix fibers and at the outer sites, and located, either parallel or orthogonally, at the periphery of individual collagen fibrils. Compositional and ultrastructural similarity between matrices and tissue structures like cartilage and basement membranes can be realized after attachment of specific GAG types. It is concluded that EDC/NHS is generally applicable for attachment of GAGs to collagen. Modulation of crosslinking conditions provides matrices with well-defined GAG contents, and biodegradabilities. Ultrastructural similarities between artificially engineered scaffolds and their possible application site may favor the use of specific collagen-GAG matrices in tissue engineering.

Animals↗
PubMed2002

Ultrastructural identification of dividing cells in the adult mammalian central nervous system.

In most parts of the adult mammalian central nervous system cell division is a relatively rare event, which makes it difficult to study at the ultrastructural level. We designed a protocol for reliable ultrastructural identification of proliferating cells in a tissue volume using DNA-incorporated 5-bromo-2-deoxyuridine (BrdU) as a marker. After BrdU administration the tissue is fixed and embedded in hydrophilic resin (LR Gold) and then cut in serial 1-2 microm sections and mounted on glass slides. BrdU is detected at the light microscopic level using immunogold labeling followed by silver enhancement, according to a standard procedure. After detection of labeled nuclei the section is reembedded in resin on the same glass slide. The glass is then dissolved in hydrofluoric acid and labeled cells cut in ultrathin sections for further ultrastructural analysis. The technique was tested and refined in sections of the intestine containing numerous dividing cells and, once optimized, was then applied to identify the ultrastructure of slowly proliferating putative stem cells in the adult mouse spinal cord.

Animals↗
PubMed1996

Assessing ultrastructure of crustacean and insect neuromuscular junctions.

Motor nerve terminals of arthropods provide excellent models for study of synaptic transmission, and their ultrastructure can be investigated in the same endings from which physiological recordings have been obtained. An experimental procedure for marking a recording site for subsequent ultrastructural analysis is described. The most commonly used procedure for ultrastructural analysis has been serial sectioning and three-dimensional reconstruction. This procedure has the advantage of providing information about the entire nerve terminal, including quantitative information on number, sizes, and relative positions of individual synapses and presynaptic 'active zones'. However, several errors may be generated in the process of viewing the sections and making the reconstruction; these errors can in principle lead to overestimation of synapse and active zone size. The errors become relatively more serious for smaller structures. Procedures for alleviating some of the possible errors are outlined. It is desirable to have additional information from other methods, such as freeze-fracture replication, to guide analysis of reconstructions from serial sections. Combined physiological and ultrastructural analysis of arthropod terminals has shown that each terminal has many small synapses, differing in size and in number of active zones, and that in some terminals, many of the observed synapses have a very low probability of transmission when nerve impulses occur at low frequencies.

Animals↗
PubMed2000

Responses of spruce seedlings (Picea abies) to exhaust gas under laboratory conditions--II. Ultrastructural changes and stomatal behaviour.

This study examines the effects of exhaust gas exposure on the epistomatal wax structure and mesophyll ultrastructure in needles of Norway spruce (Picea abies (L.) Karst.) seedlings. Stomatal diffusive resistance was also measured. Two independent exhaust gas fumigations were performed: 100 and 200 ppb measured as NO(x), for 10 days and 50, 100 and 200 ppb NO(x) for 19 days. The obstructive effect of exhaust gas exposure on epistomatal wax tubules was apparent. The stomata became covered by flat and solid wax resulting from the structural degradation of the wax crystalloids. Increasing the exhaust gas concentration in the chamber atmosphere exacerbated the degradation of the wax structure. Exhaust gas exposure induced aggregation and electron translucence of plastoglobuli, swelling of thylakoids, increase of cytoplasmic lipids and slight increase of vesiculation of cytoplasm in mesophyll cells of current and previous year needles. These changes were exemplified in current year needles. Damage to the epicuticular waxes and mesophyll ultrastructure of spruce needles most likely reflects the NO(x) and volatile hydrocarbon fraction. The alterations in epicuticular waxes and mesophyll ultrastructure can be related to accelerated senescence of the youngest, photosynthetically active, needle generation. The exhaust gas also resulted in decreased diffusive stomatal resistance at night which indicates that the exhaust gas exposure disturbed the gas exchange of spruce seedlings. The results show that even relatively short-term exposure to realistic concentrations of exhaust gas in the atmosphere can induce rather severe injuries to the needle surface structure as well as ultrastructure at the cellular level.

Journal Article↗
PubMed1991

Dermatofibrosarcoma protuberans. A histological and ultrastructural study of 11 cases with emphasis on the study of recurrences and histogenesis.

Eleven cases of dermatofibrosarcoma protuberans (DFSP) (6 male: 5 female; mean age +/- SD: 48.7 +/- 16.1 years) were reviewed in an attempt to correlate the histological and ultrastructural findings with the recurrence pattern of these tumours and to shed light on their histogenesis. Six (54.5%) of the tumours recurred: 3 with a similar appearance to the primary tumours, 2 with fibroblastic malignant fibrohistiocytic pattern (F-MFH), and one with fibrosarcomatous features (F), confirmed ultrastructurally. In one primary tumour with associated F features there were two recurrences. The ultrastructural findings of 6 primary tumours (2 with and 4 without recurrences) showed a predominance of primitive mesenchymal cells. The comparison between the features (sex, age, site, necrosis, mitotic rate size) of recurring DFSP vs DFSP without recurrences did not yield any significant difference. At follow-up (range: 11-108 months) all patients were alive and well. These findings support the assumption that DFSP originates from primitive mesenchymal cells that are able to show, at least, F and F-MFH differentiation, and corroborate the low-grade malignancy of DFSP regardless of their macroscopic, histologic and ultrastructural characteristics.

Adult↗
PubMed1982

Endometrial hyperplasia and carcinoma. Are ultrastructural, biochemical and immunocytochemical studies useful in distinguishing between them?

Endometrial hyperplasia and carcinoma represent different points in a disease continuum which may be difficult to distinguish using standard histologic criteria. The role of ancillary biochemical, ultrastructural and immunocytochemical techniques in understanding the normal physiologic responses to hormonal stimuli is briefly considered in order to serve as a basis for an analysis of abnormal proliferative states. Not surprisingly, the ultrastructural and biochemical features of hyperplastic and carcinomatous endometria demonstrate a progressive continuum of abnormalities. The role of the immunohistologic detection of CEA, HCG, Casein, and other markers in distinguishing between the various endometrial diseases is discussed. The endometrium represents one of the more spectacular of endocrine target organs in which marked morphologic and ultrastructural changes occur throughout a women's lifetime. Such changes include those accompanying the menarche and the menopause as well as the extensive remodelling which occurs during the reproductive years. During the latter period, the endometrium cyclically proliferates, undergoes secretory differentiation, regresses, degenerates and regenerates. These regularly occurring changes are distinctive and have been described in histological detail, (Noyes et al., 1950, Noyes, 1973, Dallenbach-Hellweg, 1974), as well as ultrastructurally (Cavazos and Lucas, 1973, Ferenczy and Richart, 1974, Ferenczy, 1977). Morphological studies, coupled with advances in knowledge of steroid biochemistry, have confirmed that the cyclic morphological alterations are under the regulatory role of estrogens and progesterone.

Adenocarcinoma↗
PubMed2000

Ultrastructural analysis of 20 intraosseous endolymphatic sacs from patients with cerebello-pontine angle tumours. A surgically obtained control material for histopathological studies.

OBJECTIVE: The purpose of this work was to collect a surgically obtained, freshly fixed material of the human intraosseous endolymphatic sac. This biopsy material was used to describe the normal ultrastructure as well as to serve as a control material for histopathological studies on Ménière's disease in particular. METHOD: The specimens, obtained during surgery for cerebello-pontine angle tumours, were fixed by immersion and then prepared by routine methods for transmission electron microscopy. The ultrastructural analysis was focused on intraluminal content, epithelial cell layer, subepithelial space, and morphological signs of immunological activity. The ultrastructure was analysed in relation to inner ear sensory function, tumour diagnosis, and patient's age and sex. RESULTS: As it was possible to obtain numerous specimens with an intact bony shell, the intraluminal substance could be analysed. Two separate epithelial cell types are described: one less abundant, often lighter and mitochondria-rich cell type; the other, often darker, epithelial cell with fever mitochondrias. Some of the latter cell types showed signs of active secretion. The subepithelial space was characterized by loose connective tissue adjacent to the epithelial lining, being more dense toward the bone. Elastic fibres were seen surrounding the entire endolymphatic sac. Macrophages in the intraluminal space and lymphocytes in the epithelial and subepithelial layers are described. No distinct morphology correlating to inner ear sensory function, tumour diagnosis, or patient's age and sex was revealed. CONCLUSIONS: This study confirms previously described, extensive variations in form and structure of the human endolymphatic sac. Various factors, such as surgical trauma, previous treatment, and processing method, can affect the ultrastructure and must be taken into consideration. The specimens described in this work appear to constitute a good control material for histopathological study of the human endolymphatic sac. It is still necessary to obtain large control materials such as this, as surgical specimens from patients with Ménière's disease are uncommon.

Adult↗
PubMedDate not supplied

The effect of radiofrequency energy on the ultrastructure of joint capsular collagen.

This study evaluated the effect of radiofrequency energy on the histological and ultrastructural appearance of joint capsular collagen. Femoropatellar joint capsular specimens from adult sheep were treated with one of three treatment temperatures (45 degrees C, 65 degrees C, and 85 degrees C) with a radiofrequency generator or served as control in a randomized block design. Twenty-four specimens (n = 6) were processed for histological examination as well as ultrastructural analysis using transmission electron microscopy. A computer-based area determination program was used to calculate the area affected in histological samples. Histological changes consisted of thermal tissue damage characterized by collagen fiber fusion and fibroblastic nuclear pyknosis at all application temperatures with clear demarcations between treated and untreated tissue. Mean tissue affected ranged from 50.4% for 85 degrees C to 22.5% for 45 degrees C. There was a strong correlation between treatment temperature and percent area affected (P < .001, R2 = .65). Ultrastructural alterations included a general increase in cross-sectional fibril diameter and loss of fibril size variation with increasing treatment temperature. Longitudinal sections of collagen fibrils showed increased fibril diameter and the loss of cross-striations in the treated groups. Thermally induced ultrastructural collagen fibril alteration is likely the predominant mechanism of tissue shrinkage caused by application of radiofrequency energy.

Animals↗
PubMedDate not supplied

Tamoxifen induces ultrastructural alterations in membranes of Bacillus Stearothermophilus.

Tamoxifen (TAM), a non-steroid antiestrogen, is the mostly used drug for chemotherapy and chemoprevention of breast cancer. However, the mechanisms by which TAM inhibits cell proliferation in breast cancer are not fully understood. TAM strongly incorporates in biomembranes and a variety of effects have been assigned to biophysical and biochemical interactions with membranes. Therefore, a better understanding of the physicochemical basis of interaction of TAM with biomembranes is essential to elucidate the molecular mechanisms of action. A strain of Bacillus stearothermophilus has been used as a model to clarify the interaction of TAM with the cell membrane. TAM effects on the ultrastructure of membranes of this bacterium were evaluated by electron microscopy. Important ultrastructural alterations were observed in B. stearothermophilus treated with TAM, namely change in the geometry of the membrane profile from asymmetric to symmetric, disaggregation of ribosomes, coagulation of the cytoplasmic matrix, occurrence of mesossomes, appearance of fractures in membranes and the alteration of the ultrastructure of cell wall. These ultrastructural alterations confirm that TAM is a membrane-active drug and that membrane damage may be involved in molecular mechanisms of cell death induced by this drug.

Dose-Response Relationship, Drug↗
PubMed1989

Ultrastructural pathology of iron overload.

The study of the ultrastructural changes in the iron-laden organism has indicated the presence of a number of 'defensive' features, best understood if examined according to a concept of biological levels. At the molecular level, the main features are: the increased capacity of cells to bind toxic, inorganic iron to a specific storage protein, apoferritin, which becomes visible due to its iron-containing, electron-opaque core; since iron itself is involved in the de-repression of apoferritin synthesis, the number of assembled ferritin molecules depends on the amount of unbound iron present in the cell; there is a maximal, cell line-specific concentration of cytosolic ferritin; ferritin particles have a variable iron content, with richer molecules having a tendency to form clusters. At the cellular level, the transport of ferritin into the lysosomal compartment with formation of ferritin and haemosiderin-containing siderosomes enables further segregation of iron and permits cell survival even in the new steady-state of cytosiderosis. When siderosomes increase beyond a cell line-specific concentration, signs of organelle alteration followed by cellular death are noted. At the tissue level, the contributory ultrastructural observations include finding of early intercellular fibrosis, atypical (amorphous) iron deposition, as well as the accessibility of a detailed assessment of iron distribution in various cell types, i.e. endothelium, parenchymal cells, RE cells. The ultrastructural study of material obtained from human subjects with various stages of iron overload and of experimental animals facilitates the understanding of the process of iron overload itself and of the ensuing cellular damage. The recent emphasis on iron as a putative contributory factor in infections, as well as its role in neoplasia, has provided new directions for research, both clinical and experimental. Ultrastructural observations, combined with biochemical, immunological and biophysical investigations, are mandatory for providing answers to the numerous pending questions related to iron metabolism. Sequential electron microscopic studies of iron-laden cells enable the evaluation of chelating agents in either clinical or experimental conditions.

Ferritins↗
PubMed2002

Ultrastructure of the Schistosoma mansoni cercaria.

The cercaria of the schistosome parasite is a short-lived, free-swimming larval stage that is infective for the mammalian, definitive host. This atlas describes the ultrastructure of the cells that comprise the cercaria of Schistosoma mansoni, a leading causative agent of human schistosomiasis. In addition to the cells which make up the various organ systems, such as the nervous, tegumental, osmoregulatory, muscular and primordial digestive systems, also we show the ultrastructure of those cells whose organization or location are not as well defined structurally but are essential nevertheless for the success of the parasite. These latter include the various support cells, and those cells that, upon differentiation into the adult worm, serve reproductive functions. A description is also given of the cells whose sole functions are realized only at the cercarial stage, chiefly involved in the vigorous act of skin penetration. Although we include a detailed review of the ultrastructure of S. mansoni cercariae, much of the information reported has not been previously published. In summary, this paper brings together an ultrastructural description of all the cell types presently known that make up the much studied larval stage of this medically important trematode.

Animals↗
PubMed1999

Ultrastructural characteristics of TSH-producing adenomas with special reference to its close similarity to BFA-treated pituitary adenoma cells.

Two of 420 patients with pituitary adenoma who underwent operation from 1989 to 1997 had thyroid stimulating hormone (TSH) producing adenoma. We investigated these TSH cell adenomas with immunohistochemical and ultrastructural methods and compared their ultrastructural features with brefeldin A (BFA, 0.5 mg/ml) treated pituitary adenoma cells. BFA-treated pituitary adenomas include a prolactin (PRL) cell adenoma, a growth hormone (GH) cell adenoma, an adrenocorticotropic hormone (ACTH) cell adenoma, a gonadotroph adenoma, and a plurihormonal adenoma. Immunohistochemical staining disclosed that one of the TSH cell adenomas produced only TSH-beta and that another produces both TSH-beta and FSH-beta. Ultrastructural analysis showed the abundance of oval-shaped dilated rough endoplasmic reticulum (rER). Within the dilated rER, the mistlike deposit or deposit along the inner margin of the rER membrane was observed. On the other hand, BFA-treated cultured pituitary adenoma cells showed the opening of the cavity of the rER cisterna and they enlarged to an oval form with time and revealed an accumulation of electron-dense deposits within the dilated rER. These ultrastructural similarities between TSH cell adenoma and BFA-treated pituitary adenoma cells indicate the functional disturbances in the secretory passage through the Golgi apparatus in TSH cell adenoma cells.

Adenoma↗
PubMed2001

Chaetotaxy and ultrastructure of sensory receptors in the cercaria of a species of Allassogonoporus Olivier, 1938. (Digenea:Lecithdendriidae).

A standard procedure that combines chaetotaxic, ultrastructural and neuromorphological observations has recently provided a new perspective to the study of cercarial sensory systems. In the present work, we aimed to extend the use of this combination of techniques to investigate the chaetotaxy of Allassogonoporus sp. in conjunction with the ultrastructure of sensory receptors and neuromorphology. Five nerve regions were distinguished. A conspicuous bilobed cerebral ganglion was observed at the level of the pharynx. The chaetotaxic pattern was generally consistent with that of other lecithodendriids. Four types of receptors were distinguished with scanning electron microscopy. These types differed in cilium length (short, moderately long or long) and tegumentary collar length (moderately low or high). Internal ultrastructure of receptor type IIAL revealed an unsheathed cilium, a closed basal body, septate extracellular junctional complexes and thickened nerve collars. Some receptor types were site-specific. Long uniciliated receptors were found mainly on the dorsal surface, whereas short uniciliated receptors were widespread across the tegument. Ultrastructure and site-specificity observations suggest that most sensory receptors are mechanoreceptors, probably reflecting the important role mechanoreception plays in host finding.

Acetylthiocholine↗
PubMed1989

Ultrastructural changes in IgA nephropathy in relation to histologic and clinical data.

In order to evaluate the ultrastructural changes in IgA nephropathy (IgAN) and their relationship with light microscopic and clinical features, renal biopsy material from 239 Korean patients with IgAN was studied by light, electron and immunofluorescence microscopy. Forty-one were children and 198 were adults. Modified classification of Meadow et al (1972) for Henoch-Schönlein nephritis was used for the histologic grading of glomerular lesions. Forty-three adults (18%) exhibited histologic grades IV and V lesions in association with more severe clinical findings, when compared to the remaining 196 patients with histologic grades I to III. A significant difference was noted between children and adults in the severity of the glomerular lesions (P less than 0.01). Mesangial deposits were observed in all (100%), subendothelial deposits in 37%, subepithelial deposits in 18%, abnormalities in glomerular basement membrane (GBM) in 20%, mesangiolysis in 44%, and mesangial interposition in 25%. The frequency of GBM abnormalities and subepithelial deposits in children was significantly higher than that seen in adults (P less than 0.01). The abnormalities of GBM were not related to more severe clinical manifestations when our analysis was restricted to grade III histologic lesions. All of the above ultrastructural changes except for mesangial deposits were associated with more severe histologic grading in adults (P less than 0.025 or P less than 0.01). Yet a correlation between these ultrastructural changes and histologic grading could not be studied in children due to confinement of their histology within a more benign group. These results suggest that the five ultrastructural parameters described here appear to bear important prognostic value in adults with IgAN.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Ultrastructural comparison of penile cavernous tissue between hypertensive and normotensive rats.

Our aim was to compare the ultrastructure of penile cavernous tissue in the spontaneous hypertensive rat (SHR) and normotensive rat, and study the relation of blood pressure with erectile function. After injection of apomorphine (APO), penile erectile frequency in 16-week-old SHR (group A) and Wistar-Kyoto rat (WKY) (group B) was observed and noted. The ultrastructure of the penile cavernous tissue was studied by scanning electron microscope and transmission electron microscope. The mean blood pressures were significantly higher in group A than in group B (P=0; 171.20+/-10.94 and 117.60+/-12.38, n=5, for group A and group B, respectively). After treatment of the two groups with APO, the erectile frequency in group A was significantly less than in group B (P=0.007; 0.40+/-0.55 and 2.40+/-1.14, n=5, for group A and group B, respectively). Significant ultrastructural pathological changes were observed in the tunica albuginea and penile cavernous tissue of SHR. The elastic fibers were decreased and the collagen fibers of the sinusoid were increased in group A. The tunica albuginea thickness (mean+/-s.d.) was 100.20+/-7.22 microm and 126.00+/-7.65 microm in group A and group B, respectively. The tunica albuginea of group A was significantly thinner than that in B (P=0.001). Some endothelial cells and smooth muscle cells exhibited damaged mitochondria, and endoplasmic reticulums and Schwann cells were degenerated in group A. Although the function of penile erection might be affected by a secondary effect related to endothelial dysfunction of hypertension, these ultrastructural pathological changes of the penile cavernous tissue might also be one of the important mechanisms of erectile dysfunction caused by hypertension.

Animals↗
PubMed1998

Acute myeloblastic leukemia with minimal myeloid differentiation: phenotypical and ultrastructural characteristics.

AML-M0 is an infrequent form of acute myeloblastic leukemia characterized by negative reaction with myeloperoxidase (MPO), Sudan Black and lymphoid antigens and positivity for CD13 or CD33. In the present study we describe the immunophenotypical and ultrastructural characteristics of a group of AML-M0 in adult patients. Nine out 218 AML leukemias (4.1%) fulfilled the AML-M0 criteria. CD13 or CD33 were positive in eight out nine cases, with two or more positive myeloid antigens being present in 82% of the cases. Immunological MPO was positive in 57% of the cases and CD68 in 33%. In no case megakaryocytic and erythroid markers present. Four cases (44%) expressed CD7 and TdT but only two coexpressed both antigens. In none of the cases was CD3 or CD22 cytoplasmic expression found. Ultrastructurally, a low number of granules was seen in all cases whereas ferritin particles or rhopheocytosis were not observed. Ultrastructural MPO was positive in one out of five cases and platelet peroxidase (PPO) was negative in the four cases studied. Two out of six cases showed karyotypic abnormalities (hypotetraploidy and a complex karyotype, respectively). In two out three cases a rearranged pattern for JH gene was observed. TCR (Cbeta and Jgamma) rearrangements were not detected in any case. AML-M0 is an infrequent form of acute myeloblastic leukemia. A large panel of myeloid monoclonal antibodies (MoAb) and the study of the cytoplasmic expression of myeloid antigens is necessary to diagnose this form of leukemia. AML-M0 usually coexpress lymphoid markers. Ultrastructural studies may be of help to discard an immature erythroid proliferation.

Adult↗