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PubMed1994

Energy-filtering transmission electron microscopy as a tool for structural and compositional analysis of isolated ferritin particles.

Structural and compositional analysis of isolated horse-spleen ferritin particles was performed by energy filtering transmission electron microscopy (EFTEM). Ferritin particles were collected in ultrathin (2 nm thick) chromium films and analyzed without any additional stain by electron energy-loss spectroscopy (EELS) for iron and carbon and by electron-spectroscopic imaging (ESI) for carbon. The ultrastructure of the proteinaceous shell of the ferritin particle, as obtained by the carbon net-intensity electron spectroscopical and carbon concentration-distribution images, was qualitatively compared to the structure as acquired by a negative-staining procedure. Quantitative analysis of the number of carbon atoms in the ferritin-shell proteins was carried out through an ESI-acquisition protocol and processing procedure with calibrated attenuation filters in the optical path to the TV camera. This procedure included images acquired with calibrated attenuation filters for the compensation of shading and the non-linear performance of the TV camera used in the analytical part of the procedure. A new ¿ESI-Spectra¿ program is proposed that allows element-related spectra to be generated at any place and with any frame size in a contrast-sensitive or other type of image present on the computer monitor screen.

Animals↗
PubMed1996

Expression and function of autocrine motility factor receptor in human choriocarcinoma.

OBJECTIVE: Our purpose was to determine whether human choriocarcinoma cells express autocrine motility factor receptor (AMF-R) and to study its function in this tumor system. STUDY DESIGN: The expression and localization of AMF-R were compared in choriocarcinoma and normal placental trophoblasts using both cell lines and tissue sections. In addition, migratory properties of choriocarcinoma cells and normal placental cells was determined. RESULTS: Using immunofluorescence and immunoperoxidase staining, we have detected the expression of AMF-R in choriocarcinoma cells with receptor clustering on the cell surface, while term placenta cells expressed AMF-R less intensely with no receptor clustering. In choriocarcinoma tissues, AMF-R was strongly expressed in malignant cytotrophoblasts cells while adjacent normal villous trophoblast cells and necrotic regions were weakly or negatively stained. Choriocarcinoma cells responded to AMF-R stimulation with increased cell motility, while term placental cells were unresponsive. CONCLUSION: Human choriocarcinoma cells express functional cell surface AMF-R in vitro and in choriocarcinoma tissue suggesting that this receptor may play an important role in cancer cell motility.

Cell Movement↗
PubMed1997

Structure, subunit topology, and actin-binding activity of the Arp2/3 complex from Acanthamoeba.

The Arp2/3 complex, first isolated from Acanthamoeba castellani by affinity chromatography on profilin, consists of seven polypeptides; two actin-related proteins, Arp2 and Arp3; and five apparently novel proteins, p40, p35, p19, p18, and p14 (Machesky et al., 1994). The complex is homogeneous by hydrodynamic criteria with a Stokes' radius of 5.3 nm by gel filtration, sedimentation coefficient of 8.7 S, and molecular mass of 197 kD by analytical ultracentrifugation. The stoichiometry of the subunits is 1:1:1:1:1:1:1, indicating the purified complex contains one copy each of seven polypeptides. In electron micrographs, the complex has a bilobed or horseshoe shape with outer dimensions of approximately 13 x 10 nm, and mathematical models of such a shape and size are consistent with the measured hydrodynamic properties. Chemical cross-linking with a battery of cross-linkers of different spacer arm lengths and chemical reactivities identify the following nearest neighbors within the complex: Arp2 and p40; Arp2 and p35; Arp3 and p35; Arp3 and either p18 or p19; and p19 and p14. By fluorescent antibody staining with anti-p40 and -p35, the complex is concentrated in the cortex of the ameba, especially in linear structures, possibly actin filament bundles, that lie perpendicular to the leading edge. Purified Arp2/3 complex binds actin filaments with a Kd of 2.3 microM and a stoichiometry of approximately one complex molecule per actin monomer. In electron micrographs of negatively stained samples, Arp2/3 complex decorates the sides of actin filaments. EDC/NHS cross-links actin to Arp3, p35, and a low molecular weight subunit, p19, p18, or p14. We propose structural and topological models for the Arp2/3 complex and suggest that affinity for actin filaments accounts for the localization of complex subunits to actin-rich regions of Acanthamoeba.

Acanthamoeba↗
PubMed1993

Immunocytochemical double staining of cytokeratin and prostate specific antigen in individual prostatic tumour cells.

Early dissemination of malignant cells is the main cause for metastatic relapse in patients with solid tumours. By use of monoclonal antibodies (mAbs) specific for cytokeratins, disseminated individual epithelial tumour cells can now be identified in mesenchymal organs such as bone marrow. Further to characterize such cells in patients with prostate cancer, an immunocytochemical procedure was developed for simultaneous labelling of cytokeratin component no. 18 (CK18) and prostate specific antigen (PSA). In a first step, cells were incubated with mAb ER-PR8 against PSA and secondary gold-conjugated goat anti-mouse antibodies. In a second step, biotinylated mAb CK2 to CK18 was applied as primary antibody and subsequently incubated with complexes of streptavidin-conjugated alkaline phosphatase, which were developed with the Newfuchsin substrate. The binding of gold-labelled antibodies was visualized by silver enhancement. The sensitivity and specificity of the technique was demonstrated on cryostat sections of hyperplastic prostatic tissue, and cytological preparations of LNCaP prostatic tumour cells. Double staining was restricted to cells derived from the secretory epithelium of the prostate. Cross-reactivity between both detection systems was excluded by several controls, including the use of unrelated antibodies of the same isotype and the staining of CK18+/PSA- HT29 colon carcinoma cells. CK18+ cells co-expressing PSA were found in bone marrow aspirates from 5 out of 13 patients with carcinomas of the prostate, a finding that is consistent with the relative fraction of double-positive LNCaP cells. The specificity of CK18 for epithelial tumour cells in bone marrow was supported by negative staining of 12 control aspirates from patients with benign prostatic hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed2005

Syndecan-1 expression--a novel prognostic marker in pancreatic cancer.

OBJECTIVE: Syndecan-1 is a transmembrane receptor that participates in cell-cell and cell-matrix interactions, cell proliferation and cell migration. Expression of syndecan-1 is downregulated in many cancers, but in pancreatic ductal adenocarcinoma it is upregulated. METHOD: We studied the immunohistochemical expression of syndecan-1 in 144 pancreatic adenocarcinomas and evaluated the prognostic value of syndecan-1 expression. Formalin-fixed, paraffin-embedded specimens were stained with mouse monoclonal antibody B-B4 against human syndecan-1. The epithelial and stromal staining was separately evaluated and compared with patient survival, clinical stage and histological grade. RESULT: Epithelial immunoreactivity was observed in most of the pancreatic carcinoma samples: in 70 (49%) of the samples the epithelial staining was weak, in 48 (33%) moderate, in 18 (12%) strong and in only 8 (6%) of the samples the epithelial staining was negative. Stromal staining was weak in 24 (17%), moderate in 31 (22%), strong in 11 (8%) and negative in 78 (54%) of the pancreatic carcinoma samples. Lack of stromal expression predicted a better prognosis (p = 0.002; HR 1.7) and it was independent of stage (p = 0.01; HR = 1.5) and grade (p = 0.0004; HR 2.1) in multivariate analysis. Epithelial expression predicted better prognosis for patients that underwent surgery for cure (n = 94, p = 0.03). CONCLUSION: Stromal syndecan-1 expression is an independent prognostic marker in pancreatic cancer, whereas epithelial syndecan-1 expression predicts better prognosis only in resectable disease.

Acute Disease↗
PubMed2002

Subcellular localization of the NAD+-dependent alcohol dehydrogenase in Entamoeba histolytica trophozoites.

The protozoan parasite Entamoeba histolytica is an ancient eukaryotic cell that shows morphologically atypical organelles and differs metabolically from higher eukaryotic cells. The aim of this study was to determine the subcellular localization of ameba NAD+-dependent alcohol dehydrogenase (ADH2). The enzyme activity was present in soluble and mainly in particulate material whose density was 1.105 in a sucrose gradient. By differential centrifugation, most of the ADH activity sedimented at 160,000 g (160,000-g pellet), similar to the Escherichia coli polymeric ADHE. In the Coomassie staining of the 160,000-g pellet analyzed by electrophoresis, a 96-kDa protein was more prominent than in other fractions; this band was recognized by antibodies against Lactococcus lactis ADHE. By gold labeling, the antibodies recognized the granular material that mainly constitutes the 160,000-g pellet and a material that sedimented along with the internal membrane vesicles. By negative staining, the 160,000-g fraction showed helical rodlike structures with an average length of 103 nm; almost no membrane vesicles were observed in this pellet. In internal membrane fractions, no rodlike structures were found, but protomerlike round structures were observed. These results indicate that the main amebic NAD+-dependent ADH2 activity is naturally organized as rodlike helical particles, similar to bacterial ADHE. Detection of ADH2 in membrane fractions might be explained by cosedimentation of the multimeric ADH during membrane purification.

Acid Phosphatase↗
PubMed1975

Histochemical distribution of acid mucopolysaccharides during circadian rhythm in the cerebellum of Serranus scriba.

Histochemical analysis of AMPS (AB-staining materials) in Serranus scriba brain showed its irregular distribution in different brain regions. The highest AMPS content was observed in the optocoele and ependymal cells lining it, above the marginal telencephalon and optic tectum as well as the molecular cerebellum layer. Particularly significant AMPS concentrations were noted in Purkinje cell regions. The telencephalon and optic tectum showed AB-negative-staining materials. Following histochemical changes during a 24 h period, AMPS concentrations were shown to follow circadian variations, especially in the Purkinje cell region. The highest AMPS content was noted during the morning and the lowest during the evening hours. The above changes were discussed in the context of the role of AMPS in neural functions.

Animals↗
PubMed1996

Prognostic value of p53 in muscle-invasive bladder cancer treated with preoperative radiotherapy.

OBJECTIVES: The relationship of p53 mutations as analyzed immunohistochemically to radiation response and therapeutic outcome was examined in a cohort of 301 patients with muscle-invasive transitional cell carcinoma of the bladder treated relatively uniformly with preoperative radiotherapy (50 Gy in 25 fractions) 4 to 6 weeks prior to radical cystectomy. METHODS: Adequate formalin-fixed paraffin-embedded archival tissue for the immunohistochemical staining of p53 using antibody DO1 was obtained in 109 patients. The median follow-up for those living was 91 months. RESULTS: Overall, p53 staining was positive in 56% of the cases, with 60% positive in Stage T2 (n = 48), 42% in Stage T3a (n = 31), and 63% in Stage T3b (n = 30). Overexpression of p53 did not correlate with actuarial local control, distant metastasis freedom, disease freedom, or overall survival. However, significant associations were seen when these analyses were limited to patients with clinical Stage T3b disease. In this subgroup, the actuarial 5-year rates for patients with p53 positively and negatively stained tumors were 55% and 100%, respectively, for distant metastasis freedom (P = 0.01), 51% and 91% for disease freedom (P = 0.04), and 32% and 91% for overall survival (P = 0.006). Cox proportional hazards models that included p53 staining and other prognostic factors of significance in the univariate analyses revealed p53 to be independently predictive of survival for patients with Stage T3b disease. CONCLUSIONS: The prognostic value of p53 immunostaining rested with Stage T3b patients. Although no correlations were found with radiation response, p53 positivity in this subgroup was associated with a higher rate of distant metastasis and reduced overall survival. For these patients, p53 negativity would indicate that aggressive local treatment (that is, preoperative radiotherapy and cystectomy) is sufficient, whereas p53 positivity would indicate that multiagent chemotherapy is required because of the increased risk of distant metastasis.

Carcinoma, Transitional Cell↗
PubMed1990

The role of intermediate filaments in adrenal steroidogenesis.

Cholesterol is stored in adrenal cells as ester in lipid droplets, which are transported to mitochondria to provide a substrate for steroid hormone synthesis. Using mouse adrenal tumour cells (Y-1), we show here that approximately 33% of the adrenal cell cholesterol ester is bound tightly to intermediate filaments while the rest is either loosely attached or free in the cytosol. Specific binding of droplets to intermediate filaments was demonstrated by immunofluorescence and electron microscopy. Immunofluorescence was based upon Nile Red to stain lipid and antibodies to vimentin, actin and tubulin. Electron microscopy, including immunoelectron microscopy with protein A conjugated to gold particles (5 nm), was used to examine whole mounts of cytoskeletons and intermediate filaments. Immunofluorescence reveals that bound droplets are surrounded by a capsule containing vimentin and can be removed from the filaments by extraction with ethanol or 6 M urea. Negative staining of the urea extracts revealed isolated droplets. To the extent that cholesterol ester is the storage form of steroidogenic cholesterol, the knowledge that lipid droplets containing such esters are attached to intermediate filaments may prove important in unravelling the complex process of the transport of cholesterol to mitochondria.

Adrenal Gland Neoplasms↗
PubMed2002

Expression of the bcl-2 gene and its significance in human pancreatic carcinoma.

OBJECTIVE: To elucidate the expression of the bcl-2 gene in association with both biological characteristics of human primary pancreatic carcinoma and patient's prognosis. METHODS: The s-p immunohistochemistry assay was used to detect the expression of the bcl-2 gene on paraffin-embedded sections from 97 cases of primary pancreatic carcinoma, 32 cases of pancreatitis, and 21 cases of normal pancreas. RESULTS: Among the 97 cases of pancreatic carcinoma, 70 (72.2%) showed positive staining for the bcl-2 protein. In the 32 cases of pancreatitis, 3 (9.4%) showed positive immunostaining for the bcl-2, and in the normal pancreas cases, 1 (4.8%) showed positive immunostaining for the bcl-2. However, the positive staining rates of the bcl-2 protein were lower in tumor tissue from the patients with metastases and tumor-node-metastasis (TNM) stages III, IV than in those from those with non-metastases, well differentiation, non-invasion and TNM stages I, II. The patients with positive immunostaining of bcl-2 have a longer postoperative survival than those with negative staining. CONCLUSIONS: Pancreatic carcinoma expressed a high positivity for bcl-2. Findings suggested that the overexpression of bcl-2 is related to the carcinogenesis and progression of human pancreatic carcinoma. Bcl-2 might be one of the parameters in terms of biological characteristics and good prognosis in patients with pancreatic carcinoma.

Carcinoma↗
PubMed1981

Heterogeneity of serum low density lipoproteins in normal human subjects.

Equilibrium density gradient ultracentrifugation of serum low density lipoprotein (LDL) from twelve healthy human subjects was used to separate six subfractions with mean density ranging from 1.0268 to 1.0597 g/ml. Mean corrected peak flotation rate (Sof) measured by analytic ultracentrifugation, and mean particle diameter determined by negative staining electron microscopy, both declined significantly with increasing density of the subfractions. Major differences in chemical composition of the subfractions were noted, including a significantly lower triglyceride content and higher ratio of cholesteryl ester to triglyceride in the middle fractions compared with those of highest and lowest density. Concentration of fraction 2 correlated positively with HDL (P less than 0.01) and negatively with VLDL (P less than 0.001); concentration of fraction 4 correlated negatively with HDL (P less than 0.05) and positively with VLDL (P less than 0.001) and IDL (P less than 0.01). LDL may thus include subspecies of differing structure and composition which might also have different metabolic and atherogenic roles.

Adult↗
PubMed1992

Prevalence and expression of human papillomavirus in tonsillar carcinomas, indicating a possible viral etiology.

The presence of human papillomavirus (HPV) DNA was assessed in biopsies of tonsillar carcinomas (n = 10) and cases of tonsillitis (n = 7), serving as controls, by general-primer-mediated PCR (GP-PCR). All carcinomas appeared HPV-positive, whereas all cases of tonsillitis were HPV-negative. Additional type-specific PCR for HPV 6, 11, 16, 18, 31 and 33 revealed that 4 carcinomas contained HPV 16 DNA, 4 contained HPV 33 DNA and 1 contained an HPV 16/33 double infection. False positivity was excluded by additional Southern blot analysis of type-specific PCR-positive samples (n = 4). Further characterization of GP-PCR products by sequence analysis revealed that 2 carcinomas contained still uncharacterized HPV genotypes; one of these also contained HPV 33 DNA and one was negative by type-specific PCR. Application of RNA PCR revealed expression of HPV 16 or HPV 33 E7 encoding spliced E6*1 transcripts in all tonsillar carcinomas (n = 4) examined. Additional non-radioactive RNA in situ hybridization performed on 3 biopsies revealed the presence of HPV 16 or HPV 33 E7 transcripts exclusively localized within the carcinoma cells, whereas stroma stained negative. These findings strongly support a role for certain HPV types in the pathogenesis of tonsillar carcinomas.

Amino Acid Sequence↗
PubMed1986

Immunocytochemical distribution of transferrin and its receptor in the developing chicken nervous system.

Transferrin is the plasma protein responsible for iron transport in all vertebrates. While transferrin is known to have growth-promoting activity on a variety of cells in culture, the role of transferrin and its membrane receptor in neuronal development is unknown. Using antibodies to transferrin and transferrin receptors, we studied the immunocytochemical localization of transferrin and its receptor in developing chicken neural tissues by the peroxidase-antiperoxidase method. In 5-day-old embryonic brain, germinal cells of the ventricular zone showed a positive reaction for transferrin receptors but were negative for transferrin. By 6-7 days, transferrin-positive cells were seen in the inner layer of the ventricular zone and a few 'patches' of transferrin-positive cells were also seen in the adjacent area. By 10 days, large neurons throughout the brain were strongly positive for transferrin. By 11-16 days, all neurons in the brain showed a strong positive reaction for the protein. Thereafter, the transferrin-positive reaction became gradually weaker in neurons whereas the walls of blood capillaries showed a positive reaction for transferrin. In the adult brain, neurons showed very weak or negative staining. A similar staining pattern for transferrin was observed in the developing spinal cord and dorsal root ganglia (DRG). By 10-12 days, both spinal cord neurons and DRG neurons showed strong reactions for transferrin. Thereafter, the transferrin-positive reaction gradually diminished in older spinal cord neurons and completely disappeared from DRG neurons. Cultured cerebral hemisphere, spinal cord, and DRG neurons showed positive staining reactions for both transferrin and its receptor. Our results suggest that: transferrin is initially taken up by developing neurons from cerebrospinal fluid via receptor-mediated endocytosis; the accumulation of transferrin ultimately reaches a maximum level within immunoreactive neurons and then declines just prior to hatching; in contrast to other CNS neurons, DRG neurons accumulate transferrin only briefly and then become negative for transferrin by immunocytochemistry; and after closure of the blood-brain barrier, transferrin may reach neurons by transport across capillaries into the 'paravascular' spaces. In view of these results, transferrin may play some important but unrecognized role in early neuronal development in vivo as well as in vitro.

Animals↗
PubMedDate not supplied

Lectin-binding histochemistry of normal and osteoarthritic cartilage tissue.

Fluorescein isothiocyanate (FITC) labelled lectins were applied to study the topographical localisation and distribution of cellular as well as extracellular glycoconjugates in histological sections of normal and degenerative cartilage tissue. Using a biochemically induced model of osteoarthrosis (OA) in the knee joints of rats, the binding pattern of several lectins (wheat germ agglutinin (WGA), concanavalin A (Con A), Ulex europeus agglutinin I (UEA I), soybean agglutinin (SBA), and peanut agglutinin (PNA] in degenerative cartilage was compared with results obtained from normal healthy tissue. In response to osteoarthritic metabolic lesions the binding pattern of WGA revealed an increased cellular staining throughout the whole depth of the tissue which represents the compensatory activity of chondrocytes. The increased anabolic cell activity is maintained by enzymatic degradation of pericellular glycosaminoglycans. Osteoarthritic cartilage exposed positive fluorescence with labelled Con A demonstrating alterations in the composition of matrix glycoconjugates. The incubation of normal healthy cartilage tissue with UEA I, SBA, and PNA resulted in a completely negative staining pattern. In contrast, we could show that the affinity of UEA I to the extracellular matrix was high in degenerative cartilage indicating degradation of matrix macromolecules. The obtained data revealed a significant difference of the lectin-binding pattern between osteoarthritic and normal cartilage tissue. Therefore it can be concluded that lectins are useful histochemical tools to characterize alterations in the integrity of joint tissue by their specific binding patterns.

Animals↗
PubMed2004

Investigations into shaking mink syndrome: an encephalomyelitis of unknown cause in farmed mink (Mustela vison) kits in Scandinavia.

An apparently novel neurological disease clinically characterized by shaking, tremors, seizures, staggering gait, and ataxia was first observed in farmed mink kits in Denmark in 2000 and subsequently in Sweden, Denmark, and Finland in 2001, and again in Denmark in 2002. Lymphoplasmacytic encephalomyelitis was found in the affected kits. The lesions were most severe in the brainstem and cerebellum and consisted of neuronal degeneration and necrosis, neuronophagia, focal and diffuse gliosis, perivascular cuffs formed by lymphocytes, plasma cells and macrophages, and segmental loss of Purkinje cells. Testing was conducted to determine the cause of the disease, including general virological investigations (virus culture, negative-staining electron microscopy, immunoelectron microscopy, polymerase chain reaction for herpesviruses, adenoviruses, pestiviruses, and coronaviruses), tests for specific viral diseases (canine distemper, Borna disease, Louping ill, West Nile virus infection, tick-borne encephalitis, Aleutian disease), tests for protozoa (Toxoplasma gondii, Neospora caninum, Encephalitozoon cuniculi), bacteria (general culture, listeria, Clamydophila psittaci), and intracerebral inoculation of neonatal mice. The results of all these investigations were negative. One group of 3 mink kits inoculated intracerebrally with brain homogenate of affected mink developed clinical signs and histological lesions similar to those observed in naturally infected mink. Based on the histopathological features, it is postulated that the disease is caused by a yet unidentified virus.

Animals↗
PubMed2006

The role of immunolocalization of CD57 and GLUT-1 in cell blocks in fine-needle aspiration diagnosis of papillary thyroid carcinoma.

BACKGROUND: CD57 (Leu7), a marker for natural killer lymphocytes, and glucose transporter-1 (GLUT-1), a facilitative cell surface glucose transport protein, are expressed in a wide spectrum of epithelial malignancies. The usefulness of CD57 and GLUT-1 immunostaining was evaluated as an adjunct to assist in the diagnosis of papillary carcinoma in fine-needle aspirations (FNAs) of the thyroid. METHODS: Immunohistochemical staining for CD57 and GLUT-1 was performed on paraffin-embedded cell blocks of 50 thyroid FNA cases with the following cytologic diagnoses: 1) papillary carcinoma (15 cases); 2) atypical cytology, cannot exclude papillary carcinoma (14 cases); and 3) benign thyroid (21 cases). RESULTS: Fourteen of 15 cases with an unequivocal diagnosis of papillary carcinoma were positive for CD57 and 1 case was negative for CD57. Tissue follow-up confirmed papillary carcinoma in all 15 cases. Of the 14 cases with a diagnosis of atypical cytology, cannot exclude papillary carcinoma, 6 cases were positive for CD57 and subsequent excision confirmed papillary carcinoma in all 6 cases. The remaining 8 cases negative for CD57 included surgically confirmed goiter (5 cases), adenoma (2 cases), and papillary carcinoma (1 case). The follicular cells in all 21 cases with a cytologic diagnosis of benign thyroid were negative for CD57. Histologic follow-up of these cases confirmed the benign cytologic diagnoses. GLUT-1 was negative in all cases. The sensitivity and specificity of CD57 was 91% and 100%, respectively. CONCLUSIONS: CD57 immunostaining is a useful adjunct for the diagnosis of papillary thyroid carcinoma in cell block material. Although negative staining for CD57 does not completely exclude papillary carcinoma, positive staining aids in the accurate diagnosis of malignancy in cytomorphologically equivocal cases. GLUT-1 did not prove to be a useful marker in distinguishing papillary carcinomas.

Biomarkers, Tumor↗
PubMed1995

Significance of epithelial membrane antigen in the work-up of problematic serous effusions.

Differentiation of reactive and/or atypical mesothelial cells from malignant epithelial cells in serous effusions remains a frequent diagnostic problem. Since epithelial membrane antigen (EMA) positive malignant cells in serous effusions have been reported in almost all adenocarcinomas and most malignant mesotheliomas, immunoreactivity for EMA is felt to be less useful than other antibodies in the workup of problematic serous effusions. However, immunostaining of reactive and/or atypical benign mesothelial cells for EMA has not been well studied, with only a few series reporting either weak or negative staining for EMA. This study was undertaken to evaluate how often reactive and/or atypical appearing mesothelial cells stain positively for EMA. One hundred eighty serous effusions (115 pleural, 55 peritoneal, and 10 pericardial) from 123 females and 57 males ages 20 to 89 yr were evaluated in which an antibody panel including EMA was performed on cell blocks (141 cases), cytospins (36 cases), or both (3 cases). Of the 100 cytologically positive cases, EMA immunoreactivity was present in 97/100 (97%) cases. One EMA negative case suspicious for a metastatic renal cell carcinoma was lost to follow-up and not included in the analysis. The remaining three negative cases consisted of malignancies not expected to have EMA positive cells (small cell carcinoma, neuroblastoma, and synovial sarcoma). Therefore, EMA was positive in virtually 100% of the remaining malignant cases. In the 78 cytologically negative cases, EMA positivity was present in 3/78 (3.8%) cases. Clinical follow-up of up to 14 mo in these three cases revealed no evidence of malignancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

The infrastructure of aortic elastic fibers.

Elastic fibers are composed of a central core of elastin that is amorphous and electron-lucent in conventional transmission electron micrographs and peripheral microfibrils. A complex infrastructure within the amorphous elastin of mature rat aorta is made visible by fixation and staining with a glutaraldehyde-ruthenium red mixture in phosphate buffer or osmium-ruthenium red in cacodylate buffer. The infrastructure is composed of at least two interlacing but distinct elastic structural components; a framework of circumferentially orientated microfibrils and a three-dimensional meshwork of filaments that permeate the fiber. The latter resembles a reticulum that has previously been observed in freeze-fractured and negatively stained elastin and attributed to the supramolecular organization of elastin. Microfibrils also extend from the core of the elastic fiber into the surrounding matrix where they appear to function as anchoring fibers. These observations indicate that the elastic properties of the arterial wall are an integrated function of both elastin and microfibrils.

Animals↗