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Results for “Morphological Characterization”

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PubMed1976

Analytical subcellular fractionation studies on rat liver and on isolated jejunal enterocytes with special reference to the separation of lysosomes, peroxisomes and mitochondria.

1. Enterocytes were isolated from rat jejunum and characterized morphologically. 2. Attempts to separate the enterocyte subcellular organelles, characterized by their marker enzymes, with isopycnic centrifugation were unsuccessful but good separation of peroxisomes, lysosomes and mitochondria was achieved by sedimentation through a shallow sucrose density gradient with a super-imposed inverse gradient of low-molecular-weight dextran. 3. The properties and enzyme activities of the principal subcellular organelles in rat liver cells and enterocytes were compared.

Animals↗

PubMed1997

Structural and genetic analysis of a mutant of Rhodobacter sphaeroides WS8 deficient in hook length control.

Motility in the photosynthetic bacterium Rhodobacter sphaeroides is achieved by the unidirectional rotation of a single subpolar flagellum. In this study, transposon mutagenesis was used to obtain nonmotile flagellar mutants from this bacterium. We report here the isolation and characterization of a mutant that shows a polyhook phenotype. Morphological characterization of the mutant was done by electron microscopy. Polyhooks were obtained by shearing and were used to purify the hook protein monomer (FlgE). The apparent molecular mass of the hook protein was 50 kDa. N-terminal amino acid sequencing and comparisons with the hook proteins of other flagellated bacteria indicated that the Rhodobacter hook protein has consensus sequences common to axial flagellar components. A 25-kb fragment from an R. sphaeroides WS8 cosmid library restored wild-type flagellation and motility to the mutant. Using DNA adjacent to the inserted transposon as a probe, we identified a 4.6-kb SalI restriction fragment that contained the gene responsible for the polyhook phenotype. Nucleotide sequence analysis of this region revealed an open reading frame with a deduced amino acid sequence that was 23.4% identical to that of FliK of Salmonella typhimurium, the polypeptide responsible for hook length control in that enteric bacterium. The relevance of a gene homologous to fliK in the uniflagellated bacterium R. sphaeroides is discussed.

Amino Acid Sequence↗

PubMed2005

Radial glial cells derived from the neonatal rat spinal cord: morphological and immunocytochemical characterization.

Radial glial cells are transiently bipolar cells in the developing central nervous system, best known for their role in guiding migrating neurons. The aim of the present study was to investigate phenotypic characteristics of these bipolar precursor cells in a mixed glial cell culture system derived from the rat neonatal spinal cord. Morphological characterization was assessed by cell-specific immunocytochemical markers (nestin, vimentin, 3CB2) and transmission electron microscopy. Our study yielded substantial evidence showing that the bipolar cells exhibit immunocytochemical and ultrastructural features of radial glial cells. Immunohistochemistry of the neonatal rat spinal cord using the same cell-specific markers suggested these cells are likely derived from the subependymal zone, ventral commissure, and dorsomedial septum. We believe our data recommend this mixed glial culture system to be a valuable tool in studying radial glial cells in vitro.

Animals↗

PubMed1993

Effect of topical 5-aminosalicylic acid (5-ASA) therapy on rectal mucosal biopsy morphology in chronic ulcerative colitis.

Classic teaching emphasizes that chronic ulcerative colitis is characterized morphologically by the presence of fixed architectural and cellular mucosal changes that categorize the process as chronic. To examine the effect of topical 5-aminosalicylic acid (5-ASA) enemas on the presence of six histological features of chronicity in established chronic ulcerative colitis, 123 mucosal biopsies were taken prospectively at 1-month intervals, all from the same anatomic location (10 cm), from 14 patients treated with either 5-ASA or placebo enemas. The biopsies were evaluated for the presence of mixed inflammation in the lamina propria, crypt architectural abnormalities, basally located lymphoid aggregates, basal plasmacytosis, villiform surface epithelial configuration, and Paneth cell metaplasia. Overall, 29% of biopsies from 64% of patients were histologically normal (no chronic features, no active disease). Compared with patients treated with placebo enemas, patients treated with 5-ASA enemas showed a significantly higher percentage of normal biopsies (36% ASA group vs. 12% placebo group; p = 0.005) and a lower percentage occurrence of each individual histological feature of chronicity. In addition, patients treated with 5-ASA had a higher average number of normal biopsies per patient (3.0) than those treated with placebo enemas (1.3). Therefore, histologically normal-appearing mucosal biopsies do occur in established cases of chronic ulcerative colitis, and this finding is enhanced by treatment with 5-ASA enemas. Awareness of these results should prevent the presence of normal rectal mucosal biopsy findings in chronic ulcerative colitis patients from being misinterpreted as either evidence against this diagnosis or as representing focal skip areas characteristic of Crohn's disease.

Administration, Topical↗

PubMed2003

Morphological and immunocytochemical characterization of cultured fibroblast-like cells derived from adult human synovial membrane.

The synovial membrane (SM) is a source of multipotent mesenchymal stem cells (MSCs), which appeared microscopically to be a relatively homogeneous population of fibroblast-like cells (FCs) in culture (De Bari et al., 2001). The aim of this study was to investigate phenotypic characteristics of the SM-derived FCs (SD-FCs) that could elucidate their origin inside the synovial tissue. Morphological characterization of SD-FCs was assessed by electron microscopy and by expression of surfactant protein A (SPA). This study, yielded substantial evidence that SD-FCs show ultrastructural and immunocytochemical features of type B synoviocytes; they contained characteristic lamellar bodies (LBs) that are secreted by exocytosis. LB secretion ability was maintained upon passaging (P3-P10). Immunocytochemistry showed that SD-FCs express surfactant protein A (SP-A). Taken together, these results indicate that multipotent SD-MSCs may originate from the synovial lining, having a phenotype highly similar to that of type B synoviocytes. We believe our data highlight the potent ability of type B synoviocytes to have a multilineage differentiation potential.

Adipocytes↗

PubMedDate not supplied

Phenotypic characterization of mononuclear cell infiltrate in chronic active hepatitis (CAH) of different etiology.

The morphologic characterization of portal and lobular infiltrates of chronic active hepatitis (CAH) was performed on liver biopsy sections from 18 patients: 6 HBsAg-positive/anti-delta-negative with tissue signs of hepatitis B virus (HBV) replication, 6 HBsAg-positive/anti-delta-positive with tissue signs of hepatitis delta virus (HDV) replication, and 6 HBsAg-negative without clinical or serologic evidence of autoimmune disease. No statistically significant differences were found among all the three groups of patients studied. Results from the 6 HBsAg-negative cases with T4/T8 ratio greater than 1 confirm the differences reported between this type and autoimmune forms of CAH. The lack of statistically significant differences among patients with CAH of different etiology suggests that etiologic factors play a minor role in determining the characteristics of the inflammatory liver infiltrates.

Adolescent↗

PubMed2005

Matching procedure to morphology improves outcomes in neonates with tricuspid atresia.

OBJECTIVE: This study was undertaken to characterize morphologic substrate of tricuspid atresia with ventriculoarterial concordance and discriminate management strategies that lead to successful definitive repair. METHODS: From 1999 to 2004, a total of 150 babies with type I tricuspid atresia were enrolled from first diagnosis at 26 institutions. Antegrade pulmonary blood flow was absent in 19%, restricted in 54%, and unrestricted in 28%. Competing-risk methodology determined the time-related prevalence and risk factors for death versus cavopulmonary anastomosis and subsequent death versus Fontan completion. RESULTS: Overall 5-year survival was 86%. Initial palliation included systemic-pulmonary arterial shunt in 64%, pulmonary artery banding in 11%, and cavopulmonary anastomosis in 24%. Median age at cavopulmonary anastomosis was 6 months, with 83% undergoing bidirectional Glenn shunt and 17% undergoing hemi-Fontan procedure. By the age of 2 years, 89% had cavopulmonary anastomosis, 6% were dead, and 4% remained alive without cavopulmonary anastomosis. Risk factors for death without cavopulmonary anastomosis included presence of mitral regurgitation (P = .03) and palliation with systemic-pulmonary arterial shunts not originating from the innominate artery (P = .04). Factors associated with decreased transition rate to cavopulmonary connection included patient variables (younger admission age to a participating institution, noncardiac anomalies) and procedural variables (larger systemic-pulmonary arterial shunt diameter, previous palliation). Of patients undergoing cavopulmonary anastomosis, 75% had undergone a Fontan operation within 3 years. CONCLUSION: Smaller shunt size and decreased pulmonary blood flow decrease mortality after initial palliation and increase the rate of successful transition to cavopulmonary anastomosis. Outcomes can be improved by placing smaller shunts from the innominate artery, especially in patients with any mitral regurgitation.

Cardiac Surgical Procedures↗

PubMed1981

New morphological findings on platelets in Bernard-Soulier syndrome.

Bernard-Soulier Syndrome is characterized morphologically by many giant platelets in the peripheral blood. However, the mechanism of large platelet production has not yet been clarified. Our electron microscopic examinations revealed that some platelets have two or three definite circumferential bundles of microtubules, whereas no pathological findings were obtained in the liberation of platelets from megakaryocytes by light microscopy. From these observations, we consider that the giant platelets of Bernard-Soulier Syndrome are formed by fusion of two or three platelets while they are circulating in the peripheral blood stream.

Adult↗

PubMed1991

[The distribution and characterization of sulfated-proteoglycans in the normal human lamina cribrosa].

The distribution and morphological characterization of the sulfated-proteoglycans in the normal human lamina cribrosa under the electron microscope after staining with cationic-dye (Cuprolinic-Blue) in critical electrolyte condition were studied. Three types of Cuprolinic-Blue positive filaments were identified associated with collagen in the lamina cribrosa according to their size, electro-density and their relation to the collagen fibrils. The thin and short Cuprolinic-Blue positive filaments (referred to as CB-1 filament in this communication) distributed over the collagen fibers in relatively regular fashion. The intermediate-sized Cuprolinic-Blue positive filaments (CB-2) were seen randomly associated with collagen fibers. The clusters of large CB-3 filaments were seen unevenly associated with loosely packed collagen fibers. The higher electron density of CB-2 and CB-3 filaments than those of CB-1 filaments were also demonstrated. Cuprolinic-Blue positive dots and blots as well as various sizes of filaments could be identified in the basal lamina surrounding the collagen beams and in the basement membrane of the blood vessels.

Aged↗

PubMedDate not supplied

Oncostatin M induces interleukin-6 and cyclooxygenase-2 expression in human vascular smooth muscle cells : synergy with interleukin-1beta.

Oncostatin M (OSM), a cytokine first identified from activated monocytes and T lymphocytes, is one of the most potent autocrine growth factor for AIDS and Kaposi's sarcoma. Little is known about the effects of OSM on normal vascular cells. We thus exposed human aortic smooth muscle cells (hASMCs) to OSM, examined cell proliferation and morphology, and determined interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2) expression. OSM had a weak antiproliferative effect. After a 4-day incubation with 100 ng/mL OSM, cell count decreased to 69+/-3% of control. However, OSM induced striking changes in hASMC morphology, characterized by a polyclonal shape, in contrast to the spindle morphological feature of control hASMCs. OSM stimulated the release of IL-6 by hASMCs in a dose-dependent way; after a 48-hour exposure, values were 8.5+/-0.7, 29.7+/-3.5, 50.9+/-4.4, and 73.8+/-7.6x10(3) U/mL (n=6) at OSM concentrations of 0, 1, 10, and 100 ng/mL, respectively. OSM induced marked expression of COX-2 protein and mRNA. Leukemia inhibitory factor had no effect on hASMCs, indicating that OSM effects on hASMCs were mediated by the OSM type II receptor and not by the leukemia inhibitory factor receptor. OSM used the JAK/STAT signaling pathway, as demonstrated by rapid phosphorylation of JAK1 and specific activation of STAT1. Interestingly, OSM acted in synergy with IL-1beta on IL-6 production and COX-2 expression. In conclusion, OSM is a novel regulator of human smooth muscle cell functions, acting in concert with IL-1beta, and OSM may play a role in major vascular diseases such as atherosclerosis.

Cells, Cultured↗

PubMed1981

Freeze-fracture study of isolated lysosomes of rat liver.

Freeze-fracture electron microscopy was utilized to pursue the morphological characterization of isolated lysosomes. Combining biochemical data of purity and morphological criteria of identification, it was possible to describe the convex and concave fracture faces of lysosomes. We have compared these with the corresponding faces of tritosomes i.e. lysosomes isolated after injection of Triton WR-1339 into the animal.

Animals↗

PubMed2004

Isoform specific function of calpain 2 in regulating membrane protrusion.

Previous studies have demonstrated a role for calpains in cell migration through their capacity to regulate focal adhesion dynamics and rear retraction. In this study, we provide evidence that calpains also modulate membrane protrusion activity in fibroblasts. We find that an immortalized Capn4(-/-) fibroblast line displays an altered morphology, characterized by numerous thin membrane projections and increased transient membrane activity. Furthermore, we show that protrusion kinetics of lamellipodia at the leading edge are improperly regulated in Capn4(-/-) cells, leading to impaired net forward lamellipodial extension. To address the isoform specific functions of calpain 1 and calpain 2 during cell protrusion, we stably introduced small interfering RNAs (siRNAs) targeting each isoform into a fibroblast cell line. Despite a loss in calpain 1 activity, calpain 1 knockdown cells show normal morphology and membrane protrusion dynamics. However, cells in which calpain 2 is knocked down are characterized by a protrusive morphology, increased transient membrane activity and altered protrusion kinetics, similar to the Capn4(-/-) fibroblasts. Additionally, we find that calpain 2, but not calpain 1, is required for proteolysis of the cytoskeletal and focal adhesion proteins FAK, paxillin, spectrin, and talin. Together, our findings support a novel role for calpain 2 in limiting membrane protrusions and in regulating lamellipodial dynamics at the leading edge of migrating cells.

Animals↗

PubMedDate not supplied

Proliferative synovitis in hemophilia: biochemical and morphologic observations.

The synovium removed from the knee of a 10-year-old with hemophilia A was characterized morphologically and biochemically. The specimen showed villous hypertrophy with hyperplasia of synovial lining cells which contained abundant intracytoplasmic granules of hemosiderin. Monolayer cultures prepared from enzymatically dispersed tissue were characterized by pigment-laden fibroblast-like cells and round cells. Both explants of synovium and adherent cells secreted a large amount of latent collagenase and neutral proteinase into the culture medium. The secretion of these enzymes dropped sharply and intracellular pigment decreased with passage of these cultures. Lysozyme was secreted by the explants but was not detected in the monolayer culture medium. These data establish the degradative potential of the synovitis found in hemophilia and support the concept that recurrent hemarthrosis without inflammation is sufficient in and of itself to produce proliferative synovitis.

Cells, Cultured↗

PubMed2006

Surface characterization by atomic force microscopy of sterilized PLGA microspheres.

Atomic force microscopy (AFM) is recognized a suitable and powerful technique for surface and morphological analysis. Even if until now this technique has not been frequently used in the pharmaceutical field, it can contribute to an accurate morphologic characterization of microspheres and nanospheres. In this work, atomic force microscopy has been used to perform the surface characterization of sterilized microspheres. The aim is to investigate the morphologic modifications induced by gamma irradiation on poly(lactide-co-glycolide) microspheres loaded with ovalbumin and to compare the results obtained by AFM to those obtained by scanning electron microscopy (SEM). The results obtained show that, with respect to SEM, AFM can give some additional information regarding the modifications induced by gamma-irradiation on microspheres surface morphology. The significant changes in surface roughness after irradiation are indicative of damage due to gamma-irradiation. The unchanged surface roughness values calculated for microspheres containing PEG in their matrix, suggest that this polymer exerts a protective effect towards gamma-irradiation.

Drug Carriers↗

PubMed2003

Analysis of eggplant ( Solanum melongena)-related germplasm: morphological and AFLP data contribute to phylogenetic interpretations and germplasm utilization.

A total of 94 Solanum accessions, including eggplants and related species, were morphologically characterized based on greenhouse observations, and molecularly analysed by the AFLP technique. Morphological parameters were helpful in assessing similarities or differences among accessions, and molecular data were used to support morphological conclusions. A dendrogram was computed based on the Dice genetic distances using the neighbour-joining method. The analysis was efficient in the assignment of a species name for eight out of nine accessions that were not previously classified, and revealed that 14 further accessions were misnamed in the collection originally received. The results indicate that the taxonomy of Solanum sections and subgenera including several species should be reconsidered. The AFLP technique was revealed as an efficient tool in determining genetic relationships among species. In general, morphological observations were consistent with molecular data, indicating that both approaches complemented to define the phylogenetic status of a large genus like Solanum. In terms of eggplant breeding, the molecular analysis of the Melongena complex, and of the other sections of the subgenus Leptostemonum, establishes useful germplasm relationships in the gene pool available for the genetic improvement of the cultivated species. The results we have provided highlight an urgent necessity to include molecular parameters in handling and characterizing the genebank-deposited germplasm related to cultivated crops.

Breeding↗

PubMed1977

Comparison of thirty-seven strains of Vd-3 bacteria with Agrobacterium radiobacter: morphological and physiological observations.

Thirty-seven cultures of Vd-3 bacteria, isolated from clinical specimens, were characterized morphologically and physiologically. The cultures produced positive reactions when tested for oxidase, urease, nitrate reduction, phenylalanine deaminase, oxidative metabolism of carbohydrate substrates, and 3-ketolactose production. These peritrichously flagellated microorganisms were isolated primarily from the respiratory tract. When compared to authentic strains of Agrobacterium, they appeared to be most similar to A. radiobacter. Gas-liquid chromatography of trimethylsilyl derivatives of whole-cell hydrolysates of some of the Vd-3 strains and A. radiobacter yielded nearly identical elution patterns. The Vd-3 cultures were identified as probable strains of A. radiobacter. A method is presented for differentiating cultures of A. radiobacter from other similar bacteria encountered in clinical specimens. Although these bacteria rarely occur in clinical specimens, the clinical microbiologist should be familiar withe their outstanding characteristics.

Bacterial Infections↗

PubMed1997

The distribution of beta-amyloid precursor protein in rat cortex after systemic kainate-induced seizures.

In the current study we employed immunohistochemical techniques to identify neuronal and glial cells in specific brain areas that modulate beta-amyloid precursor protein (betaAPP) synthesis following kainate-induced seizures. In addition, antibodies directed against the FOS protein, which is generated by activation of the immediate early gene c-fos and is temporally associated with ongoing seizure activity, were used to identify transneuronal pathways activated after kainate-induced seizures (KIS). It was therefore possible to correlate the appearance of activated neuronal pathways identified by FOS-like immunoreactivity (LI) and PAPP-LI in alternate sections. In addition, we employed immunohistochemical procedures to characterize morphological changes in neuronal and glial cells following kainate-induced seizures in both young and adult rats. Our results demonstrate a specific pattern of FOS-LI induced by kainate injection. In older animals FOS-LI spreads out from limbic cortical regions, including the piriform and entorhinal cortex, to other cortical regions, including the parietal and somatosensory cortices. Seizures were associated with decrease in neuronal betaAPP-LI in both young and adult rats, whereas glial betaAPP-LI markedly increased. The increase in betaAPP-LI glia was far more extensive in adult than in young rats and the anatomical distribution of betaAPP-LI glia was grossly correlated with FOS-LI. The spread of betaAPP-LI follows seizure-activated transsynaptic pathways. It is likely that the sequence of events following kainate injection is initially triggered by c-fos gene expression, which is rapidly followed by modulation of betaAPP synthesis in parallel to, or preceding, morphological changes of both microglia and astrocytes. The present study, which extensively characterized early changes in c-fos expression and betaAPP-LI in glia following kainate-induced seizures, is a potentially useful animal model for the in vivo study of numerous facets of betaAPP synthesis and the possible role of such processes in Alzheimer's disease.

Age Factors↗

PubMed1997

Establishment of a new continuous clear cell sarcoma cell line. Morphological and cytogenetic characterization and detection of chimaeric EWS/ATF-1 transcripts.

Clear cell sarcoma (CCS), a rare tumour of deep soft tissues, often has a t(12; 22) (q13; q12) translocation that induces the formation of a hybrid EWS/ATF-1 gene. To investigate these alterations further, we established a new continuous cell line directly from a CCS taken from a 9-year-old girl. The cultures were characterized with respect to morphological, ultrastructural, immunohistochemical and karyotypical features and were tested by reverse transcription PCR (RT-PCR) for chimaeric EWS/ATF-1 transcripts. The continuous cell line, designated KAO, is tumorigenic in nude mice, and the resultant tumours resemble the primary CCS. The tumour cells and the cultured cells have melanosomes in their cytoplasm and are immunoreactive with the melanoma-specific antibody HMB45, but do not express S-100 protein. The cultured CCS cells have the t(12; 22)(q13; q12) translocation and express the hybrid EWS/ATF-1 gene. No transcripts of the hybrid gene were detected in a malignant cutaneous melanoma tested simultaneously. Although CCS and malignant melanoma are morphologically related, the present results suggest that their geneses differ at the chromosome and molecular levels. They also indicate that chromosome analysis and detection of fusion EWS/ATF-1 transcripts may be useful adjuvant tools for the diagnosis of CCS.

Activating Transcription Factor 1↗