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Results for “Morphological Characterization”

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PubMedDate not supplied

[Morphological features of the pulmonary sequestration].

The pulmonary sequestration corresponds to pulmonary tissue intra or extra-lobar with systemic arterial nutrition and collateral bronchial ramification. It is infrequent and the intra-lobar identification depends on the correct clinical signs and morphology. The correct study includes imagiologic identification of the systemic artery and morphological characterization of parenchymal changes. These allow identification of abnormal pulmonary parenchyma in intra-lobar cases and were observed using histochemical and immunohistochemical routine methods, both in intra and extra-lobar cases. Four cases of intra-lobar sequestration and four cases of extra-lobar sequestration were studied with application of histochemical techniques--Movat's pentachrome stain and Verhoeff--and immunolabelling with CK7 and TTF1. The parenchymal inflammatory distortion by collagenization was constantly seen as was BALT hyperplasia and pleuritis. By using Movat's pentachrome stain we characterized the sequestration by identifying the artery and the parenchymal changes. The CK7 was useful in the identification of parenchymal damage, together with the antibody anti-TTF1 that had a variable expression, stronger in areas of inflammation because of PII hyperplasia.

Adolescent↗

PubMed2000

Primary cell cultures of bovine colon epithelium: isolation and cell culture of colonocytes.

Epithelial cells from bovine colon were isolated by mechanical preparation combined with an enzymatic digestion from colon specimens derived from freshly slaughtered animals. After digestion with collagenase I, the isolated tissue was centrifuged on a 2% D-sorbitol gradient to separate epithelial crypts which were seeded in collagen I-coated culture flasks. By using colon crypts and omitting the seeding of single cells a contamination by fibroblasts was prevented. The cells proliferated under the chosen culture conditions and formed monolayer cultures which were maintained for several weeks, including subcultivation steps. A population doubling time of about 21 hr was estimated in the log phase of the corresponding growth curve. During the culture period the cells were characterized morphologically and enzymatically. By using antibodies against cytokeratine 7 and 13 the isolated cells were identified as cells of epithelial origin. Antibodies against vimentin served as negative control. Morphological features such as microvilli, desmosomes and tight junctions, which demonstrated the ability of the cultured cells to restore an epithelial like monolayer, were shown by ultrastructural investigations. The preservation of the secretory function of the cultured cells was demonstrated by mucine cytochemistry with alcian blue staining. A stable expression of enzyme activities over a period of 6 days in culture occurred for gamma-glutamyltranspeptidase, acid phosphatase and NADH-dehydrogenase activity under the chosen culture conditions. Activity of alkaline phosphatase decreased to about 50% of basal value after 6 days in culture. Preliminary estimations of the metabolic competence of these cells revealed cytochrome P450 1A1-associated EROD activity in freshly isolated cells which was stable over 5 days in cultured cells. Then activity decreased completely. This culture system with primary epithelial cells from the colon will be used further as a model for the colon epithelium in toxicological studies in vitro.

Alkaline Phosphatase↗

PubMed1999

The pathology of pituitary tumors.

The pathologist plays an important role in the distinction of pituitary adenomas from other tumors and tumor-like lesions of the sellar region, and in the accurate morphologic characterization of pitutiary adenomas. A clinicopathologic classification of pituitary adenomas is based on cell differentiation correlated with clinical evidence of hormone secretion; this classification emphasizes clinically relevant features that can offer guidance for patient management. The application of a rational approach to the immunohistochemical analysis of these lesions can be used to evaluate pathogenetic and prognostic markers and to predict responses to specific therapeutic modalities.

Adenoma↗

PubMedDate not supplied

The challenge of the solitary pulmonary nodule: diagnostic assessment with multislice spiral CT.

The advent of fast multiscale computed tomography (MSCT) technology has sparked new interest in the noninvasive assessment of the solitary pulmonary nodule (SPN). Fast scanning within a single breath-hold period, simultaneous acquisition of multiple thin slices with subsequent morphologic characterization of the nodule, determination of perfusion patterns as well as growth rates has led to unprecedented improvements in this emerging field. This article reviews the capabilities of MSCT in the diagnostic assessment of the SPN.

Biopsy, Needle↗

PubMed1997

Studies on the mechanism of dimethylnitrosamine-induced acute liver injury in mice.

Male and female adult C3H- +/+, C3H-gld/gld.lpr/lpr (gld.lpr) and CBA-lprcg/lprcg (lprcg) mice were given a single i.p. dose of 30 mg/kg dimethylnitrosamine (DMN). Liver tissues were collected from mice killed 6, 12, 24 and 36 hrs post treatment, and the progression of the lesions was characterized morphologically and by the TUNEL method. DMN induced centrilobular hepatic injury accompanied with acute hemorrhage, and all mice died 36 to 48 hrs after the dosing. At 12 hrs after DMN administration, centrilobular hepatocytes revealed nuclear chromatin clumping. At 24 hrs, hepatocyte nuclei became fragmented to form apoptotic cells. Ultrastructurally, chromatin was condensed into a compact granular mass or crescent granular cap at the nuclear periphery. At 36 hrs, the number of apoptotic cells increased and they protruded into the sinusoid or were engulfed by the neighboring hepatocytes. A TUNEL-positive signal preceded the morphological changes and a few normal appearing centrilobular hepatocytes were positive 6 hrs post dosing. Endothelial damage was seen immunohistochemically at 24 hrs by disruption of type IV collagen and factor VIII-related antigen, resulting in massive hemorrhage in the centrilobular to mid zone. No inflammatory reactions were observed throughout the degeneration. The findings indicate that a single i.p. administration of DMN induced severe and fatal toxicity in liver tissues in mice which resembled human fulminant hepatitis. However, as gld-lpr and lprcg mice defective in apoptosis through the Fas system also showed similar severe liver damage, the Fas/Fas ligand system is not involved in DMN-induced liver apoptosis. No other organs or tissues were damaged, and the control mouse liver was intact.

Acute Disease↗

PubMed2004

Bioelectrical impedance assay to monitor changes in cell shape during apoptosis.

Apoptosis is a strictly regulated and genetically encoded cell 'suicide' that may be triggered by cytokines, depletion of growth factors or certain chemicals. It is morphologically characterized by severe alterations in cell shape like cell shrinkage and disintegration of cell-cell contacts. We applied a non-invasive electrochemical technique referred to as electric cell-substrate impedance sensing (ECIS) in order to monitor the apoptosis-induced changes in cell shape in an integral and quantitative fashion with a time resolution in the order of minutes. In ECIS the cells are grown directly on the surface of small gold-film electrodes (d = 2 mm). From readings of the electrical impedance of the cell-covered electrode, performed with non-invasive, low amplitude sensing voltages, it is possible to deduce alterations in cell-cell and cell-substrate contacts. To improve the sensitivity of this impedance assay we used endothelial cells derived from cerebral micro-vessels as cellular model systems since these are well known to express electrically tight intercellular junctions. Apoptosis was induced by cycloheximide (CHX) and verified by biochemical and cytological assays. The time course of cell shape changes was followed with unprecedented time resolution by impedance readings at 1 kHz and correlated with biochemical parameters. From impedance readings along a broad frequency range of 1-10(6) Hz we could assign the observed impedance changes to alterations on the subcellular level. We observed that disassembly of barrier-forming tight junctions precedes changes in cell-substrate contacts and correlates strongly with the time course of protease activation.

Animals↗

PubMedDate not supplied

Nuclear structure and intranuclear retention of premature RNAs.

Eukaryotic cells are highly compartmentalized, each compartment being surrounded by a lipid bilayer. This membrane-based organization allows cells to use their volumes to encode information. The lack of intranuclear membranes suggested that the nucleus was largely devoid of structural organization. However, recent work has defined numerous specialized nuclear subdomains. Importantly, RNA processing factors do not display random distribution but cluster in defined nuclear bodies. Although these structures are well characterized morphologically, their function in relation to RNA metabolism remains elusive. In this review, we will discuss the putative participation of nuclear substructures in a quality control step of RNA biogenesis, the nuclear retention of premature RNA.

Animals↗

PubMedDate not supplied

Unusual myocardial (myostromal) "repair" in cardiac transplant patient.

A 57-year-old man received a cardiac allograft for severe ischemic heart disease. His endomyocardial biopsy at eight weeks postoperatively showed a focus of unusual myocardial morphology characterized by small diameter myocytes associated with loose, myxoid appearing stroma and a myocytic mitotic figure. We feel this may represent a unique type of myocardial repair.

Biopsy↗

PubMed2003

Comparisons of norcantharidin cytotoxic effects on oral cancer cells and normal buccal keratinocytes.

Norcantharidin (NCTD) is the demethylated analogue of cantharidin. In this study, multi-parameter assessments of morphological alterations, clonogenic efficiency, cell growth curves, DNA synthesis, and DNA strand break were employed to determine and compare the cytotoxic effects of NCTD on oral cancer KB cell line and normal buccal keratinocytes. The results showed NCTD induced significant cytotoxicity in KB cells after 24 h of exposure. Normal buccal keratinocytes were more resistant to NCTD induced cytotoxicity. The IC(50) of 24 h NCTD treatment for KB and keratinocytes were 15.06 and 216.29 microg/ml, respectively with a keratinocyte/KB selective index of 14.36. Anoikis and membrane blebbing, morphological characterization of apoptosis, were observed in about 90% of KB cells after exposure to 100 microg/ml of NCTD for 24 h compared to about 30% in keratinocytes. In addition, inhibition of colony formation was noted in KB cells even when exposed to low concentration of drug (5 microg/ml) for a short period of time (6 h). NCTD inhibited subsequent cell proliferation in KB but growth of normal keratinocytes was retarded only temporarily. NCTD inhibited DNA synthesis in both KB and normal keratinocytes. However, keratinocytes were more sensitive to DNA synthesis inhibition by low dose of NCTD. Significant DNA strand break was noted in KB cells only after cell viability was reduced to less than 60% of the control. In comparison, normal keratinocytes were resistant to NCTD induced DNA strand break. These results indicated KB cells were more sensitive to NCTD induced cytotoxicity compared to normal keratinocytes. NCTD may be of value in treating oral cancers. The underlying mechanisms of the differential actions of NCTD on these two cell types are worthy of further investigations.

Bridged Bicyclo Compounds, Heterocyclic↗

PubMed2001

Osteoprogenitor cells of mature human skeletal muscle tissue: an in vitro study.

The presence of osteogenic progenitors in human skeletal muscle is suggested by the formation of ectopic bone in clinical and experimental conditions, but their direct identification has not yet been demonstrated. The aims of this study were to identify osteogenic progenitor cells in human skeletal muscle tissue and to expand and characterize them in culture. Specimens of gracilis and semitendinosus muscle were obtained from young adults and digested to separate the connective tissue and satellite cell fractions. The cells were cultured and characterized morphologically and immunohistochemically using antibodies known to be reactive with primitive osteoprogenitor cells, pericytes, intermediate filaments, and endothelial cells. Alkaline phosphatase activity and osteocalcin gene expression were also determined. In the early stages of culture, the connective tissue cells obtained were highly positive for primitive osteoprogenitor cell and for pericyte markers. Alkaline phosphatase activity was detectable at early stages of culture and rose as a function of time, whereas primitive osteoprogenitor cell markers declined and osteocalcin mRNA expression became detectable by reverse transcriptase-polymerase chain reaction (RT-PCR). It is shown that human skeletal muscle connective tissue contains osteogenic progenitor cells. Their identification as pericytes, perivascular cells with established osteogenic potential, suggests a cellular link between angiogenesis and bone formation in muscle tissue. These cells are easily cultured and expanded in vitro by standard techniques, providing an alternative source of osteogenic progenitor cells for possible cell-based therapeutic use in certain conditions.

Actins↗

PubMed2002

Comparison of european Trichobilharzia species based on ITS1 and ITS2 sequences.

Schistosomes are parasites of considerable medical and veterinary importance and, therefore, all aspects of their biology have been intensively studied. In contrast, our knowledge of species of the largest genus, Trichobilharzia, is insufficient. Because morphological characterization of Trichobilharzia species provides a limited number of criteria for species determination, molecular data are required. In the present paper, we sequenced internal transcribed spacers ITS1 and ITS2, and 5.8S ribosomal RNA (rRNA) genes of 3 European Trichobilharzia species (T. regenti, T. szidati and T. franki). We showed that ITS1 and ITS2 sequences can be used in species identification. Repetitive elements were found in ITS1 of all 3 Trichobilharzia species; their number and length varied depending on the species. Phylogenetic analysis showed that the visceral T. franki is more related to the nasal T. regenti, than to the visceral T. szidati. The newly designed primer, which is specific for T. regenti, might be used as a tool for diagnosis of this potential pathogen.

Animals↗

PubMed2003

Tholurna dissimilis and generic delimitations in Caliciaceae inferred from nuclear ITS and LSU rDNA phylogenies (Lecanorales, lichenized ascomycetes).

The phylogenetic relationships of Tholurna dissimilis were investigated in relation to a phylogeny of twenty-three species in Caliciaceae and eighteen species from Physciaceae. ITS and LSU regions of the nuclear ribosomal DNA were used for the reconstruction of phylogenies by maximum parsimony methods. Calicium adaequatum was shown to be the closest relative of and possibly congeneric with Tholurna. Calicium is thus not monophyletic unless Tholurna is included. Calicium in the molecular phylogeny contains several distinct clades, which to some extent can be characterized morphologically. Cyphelium in a traditional sense is probably not monophyletic. Cyphelium s. str. has immersed apothecia, large smooth spores and a very thin excipulum throughout. C. inquinans and C. karelicum, which form a distinct and highly supported clade, may be accommodated in Acolium, possibly along with other Cyphelium and Calicium species. The phylogenies presented here do not support the recognition of neither Physciaceae nor Caliciaceae in a narrow sense, but they also do not exclude this. Numerous spliceosomal and unclassified insertions were found in the LSU sequences. They to some extent offered phylogenetic information both with respect to location and by their sequence similarities.

Ascomycota↗

PubMed2001

Preparation of chitosan gel beads by ionotropic molybdate gelation.

A new process is described for the preparation of chitosan gel beads using molybdate as the gelling agent. This new gelation technique leads to a structure different from that produced during alkaline coagulation of a chitosan solution. Instead of a morphology characterized by large open pores, gel beads produced in a molybdate solution, under optimum conditions (pH 6; molybdate concentration, 7 g x L(-1)), have a double layer structure corresponding to a very compact 100-microm thick external layer and an internal structure of small pores. Experimental conditions, especially pH and molybdate concentration, were selected to optimize molybdate content and the stability of the bead shape.

Biocompatible Materials↗

PubMed2005

High performance organic field-effect transistors based on amphiphilic tris(phthalocyaninato) rare earth triple-decker complexes.

LB films of three amphiphilic tris(phthalocyaninato) rare earth triple-decker complexes with crown-ethers as hydrophilic heads and long alkyl chains as hydrophobic tails have been prepared and found to display very well ordered layer structures, as proved by pi-A isotherms, UV-vis and polarized absorption spectra, X-ray diffraction experiments, and microscopic morphology characterization. These LB films have been fabricated into field-effect transistor (FET) devices, which show carrier mobilities as high as 0.24-0.60 cm2 V-1 s-1, among the highest mobilities achieved thus far for all LB film-based OFETs.

Journal Article↗

PubMed2006

Dendron-tethered and templated CdS quantum dots on single-walled carbon nanotubes.

CdS nanoparticles on the surface of single-walled carbon nanotubes (SWNTs) were templated and stabilized through the initial attachment of 1 --> 3 C-branched amide-based dendrons and were both photophysically and morphologically characterized. The CdS clusters were shown to be ca. 1.4 nm in diameter as calculated from their optical absorption spectra and exhibited reduced fluorescence emission intensity at 434 nm compared to that of CdS quantum dots stabilized by untethered dendrons due to partial emission quenching by the SWNT. Unchanged UV absorption behavior of these materials indicated that they are stable > 90 days at 25 degrees C.

Journal Article↗

PubMed2006

Calcium copper-titanate thin film growth: tailoring of the operational conditions through nanocharacterization and substrate nature effects.

A novel approach based on a molten multicomponent precursor source has been applied for the MOCVD fabrication of high-quality CaCu(3)Ti(4)O(12) (CCTO) thin films on various substrates. The adopted in situ strategy involves a molten mixture consisting of Ca(hfa)(2).tetraglyme, Ti(tmhd)(2)(O-iPr)(2), and Cu(tmhd)(2) [Hhfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; tetraglyme = 2,5,8,11,14-pentaoxapentadecane; Htmhd = 2,2,6,6-tetramethyl-3,5-heptandione; O-iPr = isopropoxide] precursors. Film structural and morphological characterizations have been carried out by several techniques [X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM)], and in particular the energy filtered TEM mapping and X-ray energy dispersive (EDX) analysis in TEM mode provided a suitable correlation between nanostructural properties of CCTO films and deposition conditions and/or the substrate nature. Correlation between the nanostructure and optical/dielectric properties has been investigated exploiting spectroscopic ellipsometry.

Journal Article↗

PubMed2006

Polymer films on electrodes: investigation of ion transport at poly(3,4-ethylenedioxythiophene) films by scanning electrochemical microscopy.

Electropolymerization, morphology characterization, and ion transport of poly(3,4-ethylenedioxythiophene) (PEDOT) films doped with different counterions (chloride, ferrocyanide (FCN), and poly(p-styrenesulfonate) (PSS-)) on a platinum electrode were investigated using scanning electrochemical microscopy (SECM) during both potential step (chronocoulometric) and cyclic voltammetric scans. An ultramicroelectrode (UME) tip was positioned close to the surface of a PEDOT-modified substrate electrode, and the responses of both electrodes to a substrate potential step or linear sweep were monitored simultaneously. Chloride or ferrocyanide (FCN) ejection during PEDOT reduction was shown to be a function of the reduction potential. The nature of the cation in the bulk solution was not found to be important in the kinetics of ion transport in PEDOT+/FCN- films. Direct evidence for the incorporation of cations of Ru(NH3)6(3+/2+) in a PEDOT film during its reduction was also obtained by SECM measurements. The adsorption of Ru(NH3)6(3+) in fully oxidized PEDOT+/PSS- films was observed and attributed to ion exchange between the Na+ co-ion of PSS- and Ru(NH3)6(3+) in the bulk solution.

Bridged Bicyclo Compounds, Heterocyclic↗

PubMedDate not supplied

A novel assay reveals that weakly basic model compounds concentrate in lysosomes to an extent greater than pH-partitioning theory would predict.

Many weakly basic drugs incubated with cells have been shown to specifically accumulate in lysosomes. The mechanistic basis and substrate specificity for this sequestration have not been rigorously evaluated; however, conditions are favorable for a pH-partitioning type accumulation. In some circumstances, this compartmentalization can be very extensive, which can impact the therapeutic efficacy of a drug. Despite the pharmaceutical importance, direct quantitative assessments of drug accumulation in lysosomes have not been previously described. We report here a novel magnetic capture technique that allows for quick and efficient isolation of lysosomes from cultured HL-60 cells that have been preincubated with model compounds. The amount of compound associated with the isolated fraction is determined by HPLC. Extensive biochemical and morphological characterizations of isolated lysosomes, together with HPLC data, allowed for estimates to be made regarding the concentration of model compounds in lysosomes. The corresponding theoretically determined concentration values, based on pH-partitioning theory, were also calculated for comparison purposes. Interestingly, experimentally determined values were approximately 3-15 times higher than theoretically predicted values. This finding suggests that mechanisms, in addition to pH-partitioning, may play a significant role in the accumulation of drugs in lysosomes.

Cell Line, Tumor↗