SEARCH · PubMed Health

Results for “Morphological Characterization”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources

PubMed1985

Induction of malignant transformation by various chemicals in Balb/3T3 clone A31-1-1 cells and biological characterization of some transformants.

Balb/c A31-1-1 cells were used for the study of transformation induction by chemicals with different mutagenic specificities. We show that survival of these cells and therefore the calculated transformation frequency per cells at risk is dependent upon the cell density at the time of treatment. It is suggested that equal cell densities should be used for measuring survival values and transformation induction. The quantitative results obtained are discussed in the light of the known mutagenic mechanisms of the chemicals tested. We also characterized morphologically transformed foci induced by different chemicals with respect to some biological properties. Anchorage independence was determined by testing growth in soft agar, loss of contact inhibition was quantitated by measuring maximum cell densities and malignancy was tested by tumor induction in nude mice. Although no very close correlation between these parameters and morphology was observed, the most malignant clones are also the ones with the highest values in the other tests. Our data make one or few genetical targets for transformation induction likely. We therefore speculate that the diverse phenotypes obtained might be due to differential activation of one or very few transforming genes in these cells.

Animals↗

PubMed1984

Immunolocalization of myosin and tropomyosin in cells undergoing ciliogenesis during regeneration of rat tracheal epithelium.

During the regeneration of the mucociliary lining of the respiratory airways, many cells differentiate into ciliated cells. Early stages of ciliogenesis in these cells is characterized morphologically by appearance of MTOC, filosomes and centrioles throughout the apical cytoplasm. Tracheas removed during the period of ciliated cell differentiation which occurs 50-60 hr after minor mechanical injury were paraformaldehyde fixed and specific affinity sites for antitropomyosin and antimyosin antibodies were demonstrated by an indirect immunoperoxidase technique. The epithelium, after development of the osmiophilic reaction product, was embedded in epoxy and observed unstained with an electron microscope. Both antibodies had similar and specific binding sites in filosomes, MTOCs, microfilaments and on the microtubule triplets and foot processes of centrioles. Such localization suggests that these mechanochemical proteins may in addition to microfilament stabilization and contraction serve a specialized function in ciliogenesis.

Animals↗

PubMed1991

Demonstration of cytomegalovirus and retrovirus pseudotypes in cultured guinea pig cells.

A mixed viral infection with a cytomegalovirus and a retrovirus in cultured guinea pig embryo (GPE) cells was investigated. The expression of an endogenous guinea pig retrovirus (GPRV) in cultured guinea pig cells was induced by a medium containing 5-bromo-2'-deoxyuridine and dexamethasone. When the induced GPE cells were superinfected with a guinea pig cytomegalovirus (GPCMV), pseudotype virions were observed. Morphological characterization of both viruses and their locations within infected cells was achieved by examination of thin sections of infected cells with transmission electron microscopy. Immunolabeling with colloidal gold particles, 5 or 15 nm in size, permitted the identification of each virus type using GPCMV- or GPRV-specific polyclonal antibodies and the detection of a population of GPCMV and GPRV particles which expressed antigens of both viruses on their envelopes. Enhanced reverse transcriptase activity of GPRV and reduced infectivity titers of GPCMV was noted in dually infected cultures. These data suggest that interaction between GPCMV and GPRV had occurred in dually infected GPE cells and that expression of GPRV was enhanced.

Animals↗

PubMed1993

Strain differences in the ratio of synaptic body types in photoreceptors of the rat retina.

In the retinal outer plexiform layer of seven different rat strains, synaptic bodies (SB) were counted and, according to their morphology, characterized as synaptic ribbons (SR), synaptic spheres (SS) or intermediate structures. It was found that absolute SB numbers showed relatively small variations while SR/SS ratios differed considerably between the strains investigated. These results are discussed with respect to retinal pigmentation and to formation and degradation, respectively, of synaptic ribbons.

Animals↗

PubMed1985

The differentiation of L5/A10 myoblast cell line (a subclone of L5 line) is controlled by changes of culture conditions.

We report here that it is possible to induce differentiation in a subline of L5 myoblast line (L5/A10) by manipulating the culture media. When L5/A10 myoblast are cultured in F14 supplemented with 10% fetal calf serum the cells grow with a division time of 12 h and reach confluency at a cell density of approximately 2.4 X 10(5) cells per cm2, without undergoing differentiation, characterized, morphologically, by formation of multinucleated fibers, and biochemically, by the synthesis of muscle specific proteins such as creatine phosphokinase or myokinase. However, cells, grown in F14 + 10% fetal calf serum, will undergo regular differentiation after a limited number of division when transferred to F14 medium supplemented with limiting concentrations (1-2%) of fetal calf serum. Investigations of the biochemistry of myoblast differentiation in cell culture will be facilitated by the availability of a cell line that can undergo differentiation under controlled conditions.

Adenylate Kinase↗

PubMed1989

Interfollicular small lymphocytic lymphoma: the diagnostic significance of pseudofollicles.

The pathologic, immunologic, and clinical features of 25 cases of interfollicular (IF) small lymphocytic lymphoma (SLL) characterized by pseudofollicles (PFs) in the IF region of the lymph nodes and by multiple reactive follicles (RFs) were examined. IFSLL is characterized morphologically by variable numbers and sizes of prolymphocytes (nuclei showing one centrally located prominent nucleolus) in the PFs and by small round lymphocytes in the IF region. The lymph nodes in our cases had multiple RFs (100%) and patent or partially patent sinuses (72%), with moderate expansion of the IF region (48%) and typically absent or minimal perinodal infiltration (48%). In 48% of the cases, the PFs surrounded the RFs, producing a pseudo-mantle zone pattern. Immunologic study showed the medium and large prolymphocytes to be mildly LN 1- and LN 2-positive, whereas the small prolymphocytes and lymphocytes were LN 1-negative and moderately LN 2-positive. Few cells in the IF region stained with UCHL-1 antibody. These data indicate the marked preponderance of the non-follicular center cell type of B cells in the IF areas. In all 11 cases tested, a monoclonal B cell population was found. The mean age of the patients was 62 years, with a male to female ratio of 1:1.7. B symptoms were present in 20% of the patients. Nineteen percent of the patients had clinical stage I or II disease, whereas 81% had stage IV disease. The median absolute lymphocyte count was 3,239 X 10(6), with a range of 767 to 13,770 X 10(6) cells/L. In six cases, the lymphocyte count was above 4,000 X 10(6), and in no case was it more than 15,000 X 10(6). It was difficult to distinguish these cases of IFSLL from lymphadenitis and other non-Hodgkin's lymphomas because it was difficult to recognize the subtle PF pattern in the presence of a partially preserved lymph node architecture. Because of the partially retained lymph node architecture and the expansion of the IF region by PFs, this lymphoma is thought to originate from the IF small B lymphocytes, which displayed an in situ growth pattern. Moreover, because of the predominant disease in the lymph nodes and the similarity of features in PFs and follicles, we conclude that IFSLL is a disease that is primary to the lymph nodes. IFSLL should be distinguished from mantle zone lymphoma and chronic lymphocytic leukemia.

Adult↗

PubMed1992

Analysis of epithelial and lymphoid phenotypic markers in relation to growth pattern of colorectal adenomas.

The relationship of villous to tubular adenomas is poorly understood and often difficult to characterize morphologically. A villous growth pattern in colorectal adenomas has been associated with a higher frequency of high-grade dysplasia. We compared phenotypic markers using immunoperoxidase techniques in paired samples of villous (75% to 100% villous) and pure tubular adenomas matched for size and degree of dysplasia, which were selected by review of 1,000 polyps from our files. The following monoclonal antibodies were used: CAM 5.2 and AE1/AE3 to cytokeratins; B18, D14, B7.1, and B7.8 to four distinct carcinoembryonic antigen epitopes; Leu-M1 and LN3 to HLA-DR antigen; LN2 to invariant chain class II major histocompatibility complex; LN1 and MB2 to B-cell markers; UCHL1 and MT1 to T-cell markers; Leu-7 to natural killer cells; Mac 387 to macrophages; S-100 to Langerhans-type cells; and a polyclonal antibody to secretory component. LN3 reactivity correlated with villous morphology and secretory component correlated with tubular morphology. Combined HLA-DR and secretory component expression discriminated between tubular and villous growth patterns in 12 of 15 pairs of adenomas (P less than .001). LN2 was expressed more frequently than LN3, but did not correlate with growth pattern. Neuroendocrine cells (Leu-7) were more frequent in tubular adenomas. Carcinoembryonic antigen epitopes did not relate to growth pattern. We did not confirm previously reported differences in cytokeratin expression. We concluded that among the markers tested, HLA-DR expression, which may have an immunologic basis, is most characteristic of colorectal adenomas that exhibit a villous growth pattern.

Adenoma↗

PubMed1992

Chediak-Higashi lymphoblastoid cell lines: granule characteristics and expression of lysosome-associated membrane proteins.

Chediak-Higashi syndrome (CHS) is characterized morphologically by the presence of giant lysosomal granules resulting from the dysregulated fusion of primary lysosomes. Lysosome-associated membrane proteins comprise a family of highly glycosylated proteins which are postulated to facilitate many aspects of normal lysosomal function. In this study, Epstein-Barr virus-transformed lymphoblastoid cell lines derived from a patient with CHS were analyzed for the presence of giant granules and the expression of the lysosome-associated membrane proteins lamp1 and lamp2. Giant myeloperoxidase positive granules typical of CHS, which had a complex structure when examined by electron microscopy, could be demonstrated in the lymphoblastoid cell lines. In situ immunofluorescence with antibodies directed against lamp1 and lamp2 demonstrated abundant expression of each of these proteins in the giant CHS granules. Lack of expression of lysosomal cathepsin G in these granules was also noted. These observations suggest that the lymphoblastoid cell lines provide a convenient model for the study of Chediak-Higashi granules and the lysosome-associated membrane proteins and provide additional evidence that CHS is a "lysosomal" disease. Further study will be necessary to delineate whether the function of these membrane proteins is altered in Chediak-Higashi syndrome.

Antigens, CD↗

PubMed1979

Multifocal fibrous pseudotumor of testicular tunics. Possible clinical dilemma.

A morphologic characterization of a tunical multifocal fibrous pseudotumor is presented because of the clinical dilemma this rare entity causes urologists and pathologists. This report demonstrates the necessity for familiarity with testicular pseudotumors in order to avoid an unnecessary orchiectomy. If histopathologic examination of biopsies from every pseudotumor nodule fails to demonstrate malignancy, excision of the entire tunics including the pseudotumors is appropriate therapy.

Adult↗

PubMed1976

Home humidifier thermophilic actinomycete isolates.

Twenty-seven thermophilic actinomycete isolates obtained from humidification systems or living-bedroom areas of individuals with suspected but unproved home environment-related respiratory disease were characterized morphologically and biochemically. All isolates were demonstrated to be members of the Thermoactinomyces genus. Two previously misidentified isolates were reclassified as a Thermoacetinomyces sp. Thus, all of our thermophilic actinomycete humidifier isolates studied to date have been identified as either Thermoactinomyces vulgaris or Thermoactinomyces sp. Large numbers of unidentified thermotolerant bacteria have also been isolated from virtually all residual humidifier water samples and their possible role in production of "humidifier-associated" respiratory disease is unknown.

Actinomycetales↗

PubMed1990

Induction of micronucleated and binucleate cells in Chinese hamster ovary (CHO) cells by cis-diamminedichloroplatinum (II): a morphological and morphometric study.

The mutagenicity and cytotoxicity of cis-diamminedichloroplatinum (II) (cisplatin) at doses of 5, 10 and 20 micrograms/ml in Chinese hamster ovary (CHO) cells have been examined. A morphological characterization of several cell types induced by cisplatin was carried out. The frequencies of both cells with micronuclei and binucleate cells as a time-dependent parameter have also been studied. Whilst the number of cells with micronuclei was found to decrease with time, the number of binucleate cells increased. The possible kinetic mechanism for the production of binucleate cells and cells with micronuclei is discussed. A morphometric analysis was also performed. The nuclear area in both treated and control nuclei was measured with the IBAS image analysis system. The results of this analysis show that a continuous reduction in the nuclear size in the control cells is produced. However the size of the treated cells increased after treatment.

Animals↗

PubMed1995

Renal involvement in feline immunodeficiency virus infection: p24 antigen detection, virus isolation and PCR analysis.

Renal alterations characterized morphologically by glomerular and tubulo-interstitial lesions and clinically by a heavy proteinuria and sometimes by renal failure are frequent in feline immunodeficiency virus (FIV) infected cats. To investigate the possible role of local FIV replication in the genesis of this renal damage, renal tissues of 15 consecutive naturally infected and five non-infected cats were examined for traces of the virus by immunohistochemistry, using a monoclonal anti-p24 antibody in a streptavidin-biotin peroxidase labeled system, cultivation and polymerase chain reaction (PCR). Tubular epithelial cells as well as scattered interstitial inflammatory and glomerular cells were positive for p24 antigen in 13 cats. Viral isolation was successful in seven cats, and FIV gag DNA and RNA sequences were detected in 14 and five cats, respectively. Control cats were constantly negative. Although not conclusive, these results suggest that a direct role of FIV in the induction of the renal damage observed in infected animals is possible.

Animals↗

PubMed1996

An anti-CD3 epsilon serum detects T lymphocytes in paraffin-embedded pathological tissues in many animal species.

The in situ identification of T cells has been difficult and restricted to frozen tissue samples of a limited range of species. In this study, we demonstrate that an antiserum recognizing a phylogenetically conserved part of the CD3 epsilon cytoplasmic tail detects T cells of many avian and mammalian species in formalin-fixed paraffin-embedded tissue sections. This antiserum enables the morphological characterization of normal and pathological lymphoid tissues and lymphoid infiltrations in experimental work and in animal disease.

Animals↗

PubMed1991

Induction of LFA-1-mediated homotypic adhesions in promonocytic U-937 cells occurs independently of cell differentiation.

The differentiation of monocytes into macrophages occurs along with a marked increase in LFA-1-dependent intercellular adhesions. Similarly, the phorbol ester-induced differentiation of U-937 promonocytic cells into macrophage-like cells is morphologically characterized by an important increase in LFA-1/ICAM-1-dependent intercellular homotypic adhesions. Since an important functional role in activation of human T cells has been demonstrated for LFA-1-dependent adherence, we have analyzed whether the induction of LFA-1-dependent intercellular adhesion of human monocytic cells is necessarily accompanied by differentiation of these cells. We found that treatment of the promonocytic U-937 cells with the anti-LFA-1 mAb NKI-L16 induces formation of intercellular clusters, but does not induce cell differentiation as determined by several differentiation markers. These markers include the arrest of cell proliferation, production of reactive oxygen species, changes in the cell surface expression of differentiation-associated antigens such as the transferrin receptor, CD11b and CD11c and changes in the levels of several specific gene transcripts such as CD18 antigen, c-myc, ornithine decarboxylase and vimentin. These findings suggest that LFA-1-dependent adhesion and differentiation of monocytic cells are independent processes.

Antibodies, Monoclonal↗

PubMed1989

The effect of substrate composition and condition on resorption by isolated osteoclasts.

Osteoclasts isolated from 10-day-old rabbits were studied in a cell culture system to obtain further insight into the possible mechanisms involved in the process of bone resorption. Osteoclasts were cultured on the surfaces of devitalized mammalian bones, a composite of polycrystalline synthetic hydroxyapatite and geological single crystal hydroxyapatite. The structural interaction of osteoclasts with these various substrates was morphologically characterized by using a scanning electron microscope. Viable osteoclasts were observed to adhere and extend pseudopodia and filopodia for all cases of calcium-phosphate surfaces. However, actual resorbing process was only observed in devitalized bone surfaces. Resorption pits of various sizes were found in multiple series and showed a preference for mineral-exposed area over collagen-exposed area. The difference observed between resorption of those areas of bone surface and the failure of osteoclasts to resorb non-tissue substrates are discussed in relation to current theories of the mechanisms of mineral dissolution and resorption in mammalian calcified tissues.

Animals↗

PubMed1992

Role of ochratoxin in disease causation.

Under experimental conditions renal damage has been induced by alimentary exposure to ochratoxin A in all single-stomach animals tested so far, including rodents, dogs, pigs and birds, and even in young ruminants still functioning as single-stomach animals. Most information on ochratoxin-induced nephropathy has been obtained in pigs during experimental studies comprising structural as well as functional changes. The renal damage is characterized morphologically by atrophy of the proximal tubules, interstitial cortical fibrosis and sclerotized glomeruli, and functionally by impairment of tubular function indicated by a decrease in TmPAH/Cin and reduced ability to produce concentrated urine. The renal effect has been observed using exposure levels of ochratoxin A in the range 200 to 4000 micrograms/kg feed. Field cases of ochratoxin-induced nephropathy in pigs have been encountered in many countries, and the disease mycotoxic porcine nephropathy (MPN) is recognized as an endemic disease entity in several northern and central European countries. Epidemics of MPN have been reported, closely related to excessive climatic conditions in periods preceding harvest. Ochratoxin A is a recognized renal carcinogen in the mouse. In female pigs exposed to alimentary ochratoxin A for 2 years, no renal cancer was observed. Ochratoxin A is metabolized and excreted relatively fast in animals, with an RL50 (residue elimination) in the pig of a few days for various tissues. Past exposure data is a requirement in retrospective epidemiological studies, but because of the short RL50 values tissue analysis for ochratoxin A is unlikely to provide that kind of data, in animals or in humans. In order to meet this demand a procedure has been developed, using renal biopsy material for activity analysis of two renal tubular enzymes, phosphoenolpyruvate carboxykinase and gamma-glutamyl transpeptidase. In pigs exposed to ochratoxin A for 1 week a 40% reduction of the enzyme activity was observed. The dose-related activity decrease of the two enzymes was accompanied by a dose-related aggravation of renal impairment, as measured by a reduction of TmPAH/Cin, suggesting that these enzymes are sensitive indicators of ochratoxin A-induced nephropathy.

Animals↗

PubMed1994

Granular layer collaterals of the unipolar brush cell axon display rosette-like excrescences. A Golgi study in the rat cerebellar cortex.

The unipolar brush cell (UBC) is a medium-sized neuron located in the granular layer of the cerebellar cortex and morphologically characterized by a single dendritic shaft terminated by a brush-like tuft [Mugnaini and Floris, J. Comp. Neurol., in press]. This neuronal class is mostly encountered in the vestibular part of the cerebellum, although also present in the rest of the vermal folia. The UBC axon, as seen in Golgi impregnated material, has a tortuous course throughout the granular layer and gives off number of collaterals of variable diameter. Some of the axon collaterals enter the white matter only for a short distance, after which they ascend into the granular layer. Astonishingly, some of the thick granular collaterals of these axons display characteristic expansions resembling the rosette excrescences seen on mossy fibers. In our series these rosettes are mostly of the simple type [Palay, S. and Chan-Palay, V., Cerebellar Cortex. Cytology and Organization, Springer, Berlin, 1974], i.e. short swellings with simple globular contours. The exact projection targets and functional effect of the UBC axon and granular rosettes have still to be demonstrated.

Animals↗

PubMed1982

Fractionation of the rat ventral prostate with respect to isolation and exocytosis of the prostatic secretion protein.

The ventral prostate was fractionated into one mitochondrial and three microsomal fractions. The different fractions were characterized morphologically and chemically. An interesting finding was that upon homogenization the endoplasmic reticulum membranes often turned 'inside-out' giving rise to microsomes with ribosomes attached to the inside of the vesicles. The secretion of the prostatic secretion protein was studied by means of isotopic pulse labeling using radioactive leucine. Peak radioactivity in the microsomal fraction was obtained at 2 h after injection with a relatively rapid fall. The radioactivity in the secretory fluid displayed a continuous increase up to 8 h followed by a plateau. When prostatic secretion protein was purified from secretory fluid and microsomes using a Con A-Sepharose column it showed a typical precursor-product relationship with an early peak at 60 min in microsomal prostatic secretion protein followed by a peak in secretory fluid at 4 h. Vinblastine blocked the release of labeled secretion protein into the secretory fluid, a phenomenon characteristic for secretory proteins which are exocytosed by means of fusion between secretory granules and the plasma membrane. Following intravenous injection of [3H]estramustine, accumulation was seen in the secretory fluid. Some estramustine probably binds to newly synthesized prostatic secretion protein and follows the same route of intracellular transport and extracellular discharge as does prostatic secretion protein.

Animals↗