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Results for “Tissue Array Analysis”

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PubMed1991

How do geometric factors influence epidural spinal cord stimulation? A quantitative analysis by computer modeling.

Effects of both anatomic and electrode geometry on the recruitment of rostrocaudal fibers in the spinal cord were investigated by computer simulation of epidural spinal cord stimulation. A three-dimensional model was used, representing the geometry and electrical conductivity of the spinal cord and surrounding tissues, in combination with a model representing the electrical properties of a myelinated nerve fiber. Recruitment contours in the dorsal columns were calculated at various spinal geometries as a function of electrode position, combination and area. Cathodal position appeared to be most significant. Recruitment areas resulting from different contact combinations of a mediodorsal array were almost identical. It was shown that perception threshold largely depends on both dorsal cerebrospinal fluid width and fiber size. The usual bipolar contact separation appeared to approximate the theoretically optimal value, resulting in maximum fiber recruitment at minimum stimulus.

Analgesia, Epidural↗

PubMed1990

In situ hybridization analysis of TGF beta 3 RNA expression during mouse development: comparative studies with TGF beta 1 and beta 2.

To date, three closely-related TGF beta genes have been found in the mouse; TGF beta 1, TGF beta 2 and TGF beta 3. Previous experiments have indicated that TGF beta 1 and TGF beta 2 may play important roles during mouse embryogenesis. The present study now reports the distribution of transcripts of TGF beta 3 in comparison to the other two genes and reveals overlapping but distinct patterns of RNA expression. TGF beta 3 RNA is expressed in a diverse array of tissues including perichondrium, bone, intervertebral discs, mesenteries, pleura, heart, lung, palate, and amnion, as well as in central nervous system (CNS) structures such as the meninges, choroid plexus and the olfactory bulbs. Furthermore, in several organ systems, TGF beta 3 transcripts are expressed during periods of active morphogenesis suggesting that the protein may be an important factor for the growth and differentiation of many embryonic tissues.

Animals↗

PubMed1986

Antigenic interrelationship between the 40-kilodalton cytokeratin polypeptide and desmoplakins.

We describe here antigenic cross-reactivity between the human 40-kilodalton cytokeratin polypeptide [Moll et al] and components of bovine desmosomal plaque, namely desmoplakins I and II. This relationship was revealed by an antibody (KM 4.62), raised against cytoskeletal preparation of cultured human breast adenocarcinoma cells (MCF-7) and selected by immunoblotting and immunofluorescent labeling. In cultured human cells that contain the 40-kD cytokeratin, antibody KM 4.62 labeled arrays of filaments throughout the cytoplasm. This antibody labeled the basal layer of nonkeratinizing squamous epithelia as well as various simple (normal and malignant) epithelia and epithelial elements of the thymus. In liver tissue, labeling was obtained only in bile ducts and canaliculi but not in the hepatocytes. In bovine cells and tissues, on the other hand, immunofluorescent labeling with antibody KM 4.62 was strictly confined to desmosomes. This was verified by double immunolabeling with both antibody KM 4.62 and specific cytokeratin or desmosomal antibodies. Immunoblotting analysis indicated that the former antibody reacts specifically with the high molecular weight components of the bovine desmosomal plaque, namely desmoplakins I and II. These immunochemical results suggest that bovine desmoplakins share same structural relationship with the human acidic, 40-kD cytokeratin.

Animals↗

PubMed1991

Cytochrome c oxidase subunit VIIa isoforms. Characterization and expression of bovine cDNAs.

Subunit VIIa of bovine cytochrome c oxidase occurs in two forms, the so-called heart and liver isoforms, which have been shown by protein analysis to differ in 35% of their amino acids. We have isolated and characterized cDNAs for each isoform. The derived heart-type processed protein is 59 amino acids long, with a 21-residue presequence; the immediate C terminus differs from the established protein sequence. The liver-type processed protein is 60 residues long, with a 23-amino acid presequence. Both presequences are traditional in that they are positively charged and appear amphiphilic when helically arrayed. The presequences are only 22% identical, but they both contain conserved residues indicative of two-step processing of the precursor proteins. Southern blot analysis reveals that the bovine genome contains five to six copies of the liver-type gene as opposed to the presence of a single copy heart-type gene. Transcriptional analysis shows that heart-type message is detectable only in heart and skeletal muscle; the liver type is also seen in heart and muscle and, additionally, in the other tissues examined (liver, brain, and lung). The amino acid sequence EKQKLFQED is conserved in rat and in both isoforms in cow and human and may represent a domain of core subunit function.

Amino Acid Sequence↗

PubMed1990

Hepatic copper concentrations in purebred and mixed-breed dogs.

Histomorphologic, histochemical, and atomic absorption analysis studies were performed on liver tissue from 623 clinically normal purebred and mixed-breed dogs to assess the range of hepatic copper concentrations, the histologic distribution of copper, and the histomorphologic changes associated with the various copper concentrations that were found. Atomic absorption analysis revealed a continuous numerical spectrum ranging from less than 100 parts per million on a dry weight basis (ppm dw) to more than 2,000. No decisive numerical criterion was found that could be used to separate normal from abnormal copper concentrations because of this continuous array. The threshold for histochemical demonstration of copper-containing granules using rhodanine or rubeanic acid staining was 400 ppm dw. At this concentration the copper-containing granules were located in the centrilobular hepatocytes (zone 3 of Rappaport). Copper-containing granules were found in the midzonal and periportal hepatocytes (zones 2 and 1 of Rappaport) in livers with 1,000 ppm dw and higher copper concentrations. The majority of the 623 livers were normal histomorphologically. Multifocal hepatitis characterized by mixed inflammatory cell accumulation and centrilobular distribution was found to be associated with copper concentrations in the range of 2,000 ppm dw or higher. An appropriate upper limit for normal hepatic copper concentration in the dog was not determined based on the present study.

Animals↗

PubMed1979

Histones and histone-DNA ratios in diploid and polyploid cottons.

Histones are nuclear proteins which repress gene transcription and modify chromosome structure. They are remarkably conservative in structure throughout a wide evolutionary array of plants and animals; however, quantitative histone differences have been detected by cytological means in species having extra chromosomes. The purpose of this study was to: 1) isolate and characterize the histones of several Gossypium species and 2) relate differences to known differences in vigor, ploidy level, and genome constitution or size. Histones extracted from isolated nuclei of leaf tissues were characterized by electrophoresis on polyacrylamide gels into 14 subfractions of the five major histone classes. The subfractions were identified by various means including co-electrophoresis with known histone standards. Densitometric analysis revealed only slight quantitative differences in subfraction ratios between species. Histone-DNA ratios were significantly higher in the pentaploid species. This observed increase is considered a result of genome imbalance. These data support the premise that histones may function as generalized gene deactivators in plant species having multiple genomes.

Diploidy↗

PubMed1976

The characterization of the ACTH produced by a primary pituitary tumour in a patient with Cushing's disease.

The nature of ACTH present in pituitary tumours associated with Cushing's disease has not been previously characterized nor correlated with the electron microscopic appearance. The present report describes the culture of tumour tissue obtained from a patient with a pituitary tumour associated with Cushing's disease, and the characterization of the ACTH content of tumour and media by bioassay, immunoassay, and Sephadex G-50 gel filtration. Electron microscopic studies were also performed. The pathological diagnosis was pituitary adenoma with basophilic PAS-positive granules. Electron microscopy showed uniformity of size and shape of the tumour cells, the presence of secretory granules of varying size and density, and disorganized tubular and vacuolar arrays of endoplasmic reticulum. The bioreactive ACTH content of the tumour was 0-29 mug/g, which is markedly below that seen in the normal pituitary, but within the range reported for ectopic ACTH-producing tumours. Immunoreactive ACTH when measured by a C-terminal antibody was five-fold higher than when measured by an N-terminal antibody; the latter gave a value of 1-24 mjg/g. On Sephadex G-50 gel filtration, 9% of the N-terminal immunoreactivity was present in the Vo fraction ('big' ACTH). This latter fraction had a greater percentage of bioreactivity (28%) than previously reported for this molecular species. Analysis of the tumour culture medium revealed a variation in molecular size similar to that seen in the tumour, although the percentage of ACTH of large molecular size was greater, suggesting increased secretion of a possible 'prohormone' by the tumour. Plasma ACTH was characterized by a 2:1 ratio of immunoreactivity (N-terminal) to bioreactivity, and a 4:1 ratio of C-terminal/N-terminal immunoreactivity. This report also appears to be the first of successful short-term tissue culture of a primary ACTH-producing tumour. The granule size was considerably larger than that reported for normal pituitary ACTH-containing cells.

Adenoma↗

PubMedDate not supplied

A computerized system that uses high-frequency data for analysis of myocardial contrast echocardiograms.

Intracoronary and, more recently, intravenous injection of a contrast medium renders it possible to determine myocardial perfusion by use of ultrasound. For the analysis of the data obtained with two-dimensional phased array echocardiographic equipment, two methods can be carried out. First, in the off-line method, the images stored on video tape can be transferred to a computer memory by use of a frame grabber, after which computer analysis of the data can be performed. Second, the phased-array electronics can be directly connected to a computer. In this setup the computer controls the phased array, and the data transported consists of the high-frequency signal. Both methods are described. Some advantages of high-frequency measurements over video-densitometry are the independence of the setup of the two dimensional machine and the higher signal-to-noise ratio. Furthermore, there is the possibility to use the amplitude, phase, and frequency of the high-frequency signal. In this way a detailed study of the contrast medium is possible and the analysis can also be performed for the purpose of a combination with other methods, such as tissue identification.

Computer Systems↗

PubMed1988

Functional pacemaking area in the early embryonic chick heart assessed by simultaneous multiple-site optical recording of spontaneous action potentials.

Pacemaking areas in the early embryonic chick hearts were quantitatively assessed using simultaneous multiple-site optical recordings of spontaneous action potentials. The measuring system with a 10- X 10- or a 12 X 12-element photodiode array had a spatial resolution of 15-30 microns. Spontaneous action potential-related optical signals were recorded simultaneously from multiple contiguous regions in the area in which the pacemaker site was located in seven- to nine-somite embryonic hearts stained with a voltage-sensitive merocyanine-rhodanine dye (NK 2761). In the seven- to early eight-somite embryonic hearts, the location of the pacemaking area is not uniquely determined, and as development proceeds to the nine-somite stage, the pacemaking area becomes confined to the left pre-atrial tissue. Analysis of the simultaneous multiple-site optical recordings showed that the pacemaking area was basically circular in shape in the later eight- to nine-somite embryonic hearts. An elliptical shape also was observed at the seven- to early eight-somite stages of development. The size of the pacemaking area was estimated to be approximately 1,200-3,000 micron2. We suggest that the pacemaking area is composed of approximately 60-150 cells, and that the pacemaking area remains at a relatively constant size throughout the seven- to nine-somite stages. It is thus proposed that a population of pacemaking cells, rather than a single cell, serves as a rhythm generator in the embryonic chick heart.

Action Potentials↗

PubMed1992

High-performance liquid chromatography of sulphonamides extracted from bovine and porcine muscle by solid-phase dispersion.

A method has been developed for the analysis of sulphonamides in bovine and porcine muscle, based on solid-phase dispersion. Muscle tissue was blended with pre-washed C18 coated silica (55-105 microns), and the resulting homogeneous solid packed into a polypropylene syringe barrel. Fatty material was washed from the sample using hexane, and the sulphonamide analytes eluted with dichloromethane. The collected fraction was dried under nitrogen and reconstituted in 20% methanol in 0.01 M sodium acetate/acetic acid (pH 5) buffer. After sonication and filtration, the sample was analysed by high-performance liquid chromatography on a C18 column using UV diode array detection. Individual sulphonamides could be detected down to 0.01 ppm, whilst analyte identity could be confirmed by diode array spectrum down to 0.02 ppm.

Animals↗

PubMed1991

Diffusion of water in biological tissues.

A method is presented for obtaining simple approximate solutions for the problem of self-diffusion in an ordered array of obstacles. Our results are compared with some previous exact and approximate solutions, and we find that our method agrees well with the exact results over a large range of the volume fraction of the obstructions. It is shown that there is an important distinction between measurements of the diffusion coefficient by the capillary flow method and the spin-echo method. The modifications for the spin-echo case are given and applied to recent measurements on the anisotropy of the self-diffusion of water in striated muscle and to measurements on cysts of the brine shrimp. The analysis shows that very large volume fractions of obstructive barriers are required in order to account for the reduction in the diffusion coefficient in biological systems. Thus this model analysis leads to the supposition that a substantial fraction (20-40%) of the cell water is hydration water, or that the diffusion coefficient of the cytoplasmic water is reduced substantially from the free water value. In either case, the conclusion that a substantial fraction of cell water has diffusive properties that are altered by the macromolecules of the cytoplasm seems inescapable. In the case of NMR methodology, the measuring times are such that the values for diffusion are often influenced by the presence of macromolecular structures (obstructions) within the cells. This suggests that obstructions make a significant contribution to the value of the NMR diffusion coefficient and that NMR may have practical value for the evaluation of obstruction effects.

Animals↗

PubMed2026

Tazarotene-Induced Gene 2 Promotes Melanoma Cell Death via the Activation of Endoplasmic Reticulum Stress.

BACKGROUND: Tazarotene-induced gene 2 (TIG2), also known as retinoic acid receptor responder 2 (RARRES2), encodes the secreted protein TIG2, also known as chemerin, which is involved in immune regulation and metabolism. However, its role in melanoma remains unclear. METHODS: TIG2 expression was analyzed using The Cancer Genome Atlas, Genotype-Tissue Expression, OncoDB, and melanoma tissue cDNA arrays. To evaluate its effects on cell viability and death, TIG2 was overexpressed in A2058 and A375 melanoma cells. RNA sequencing (RNA-seq), qPCR, and Western blotting were performed to identify TIG2-regulated genes and signaling pathways. The involvement of chemokines and endoplasmic reticulum (ER) stress was further examined using the C-X-C motif chemokine ligand 10 (CXCL 10)/CXCL11 and the ER stress inhibitor tauroursodeoxycholic acid (TUDCA). RESULTS: TIG2 expression was reduced in melanoma and other skin cancers. TIG2 overexpression significantly reduced cell viability and induced cell death. RNA-seq analysis showed that TIG2 downregulated CXCL10, CXCL11, and CCL2 while upregulating ER stress-related genes such as HERPUD1 and DDIT3. Exogenous CXCL10 or CXCL11 did not reverse TIG2-mediated effects, whereas TUDCA partially restored cell viability and reduced cell death. CONCLUSIONS: These findings suggest that TIG2 suppresses melanoma cell growth by activating ER stress and modulating immune-related chemokines, highlighting its potential therapeutic relevance.

Endoplasmic Reticulum Stress↗

PubMed1990

Electronmicroscopic demonstration of HPV in oral warts.

Human Papilloma Virus (HPV) has been demonstrated in a series of benign proliferative lesions of the skin and the mucosae. The virus has also been found in verrucous laryngeal carcinoma and carcinomas of the oral cavity and other organs. DNA hybridization techniques have classified, the HPV into 51 types, some of which seem to be associated with specific lesions. In order to study the intracellular distribution of HPV, we performed ultrastructural analysis with the electron microscope on 14 specimens taken from 7 patients by large excisional biopsy, which had been histologically classified as "fibropapilloma". From each patient specimens were taken from both the clinically evident lesion and the clinically normal surrounding mucosa. The specimens were fixed with glutaraldehyde, washed with cacodylate buffer, post-fixed with potassium ferrocyanide reduced-osmium tetroxide, block stained with uranyl acetate and embedded in EPON 812. The tissues underwent to amylase digestion before the electron microscopic examination. We found a large number of viral particles in both nuclei and cytoplasm, without forming crystal array structures as described typically for the virus of the verruca vulgaris (HPV-2). No significant differences were found between the cells derived from the clinical lesion and those derived from the surrounding mucosa. The passage of viral particles from infected to not yet infected cells through the intercellular space was observed. Of particular interest, we found a high intracytoplasmatic presence of the virus and its clear abundance in the cells surrounding the clinical lesion.

Adult↗

PubMed1990

Immuno- and affinity probes for electron microscopy: a review of labeling and preparation techniques.

Immuno- and affinity probes are widely used in biology and medicine, and are becoming essential tools for the elucidation of cell structure and function. This article reviews and discusses the bewildering array of probes and preparation techniques now available for the investigation of sectioned material by transmission electron microscopy, with critical analysis of their merits. Emphasis is placed on immunogold probes and methods useful for routine preparation, gathering together information that may be used to improve labeling techniques. New data on inert dehydration for the localization of sensitive epitopes without chemical or cryofixation is presented.

Affinity Labels↗

PubMed1990

slit: an extracellular protein necessary for development of midline glia and commissural axon pathways contains both EGF and LRR domains.

The Drosophila slit locus encodes a protein with four regions containing tandem arrays of a 24-amino-acid leucine-rich repeat (LRR) with conserved flanking sequences (flank-LRR-flank surrounding these arrays), followed by two regions with epidermal growth factor (EGF)-like repeats. Each of these motifs has been implicated in protein-protein interactions as part of an extracellular domain in a variety of other proteins. Analysis of slit cDNA clones reveals that as a consequence of alternative splicing, the locus can code for two distinct protein species differing by 11 amino acids at the carboxyl terminus of the last EGF repeat. The existence of a putative signal sequence and the absence of a transmembrane domain suggest that slit is secreted, an observation supported by an analysis of its expression in tissue culture. Examining the expression pattern of slit in the embryo by antibody staining, enhancer trap detection, and in situ hybridization, we demonstrate that the protein is expressed by a subset of glial cells along the midline of the developing central nervous system. Through immunoelectron microscopy, slit can be seen on the commissural axons traversing the glial cells although it is absent from the cell bodies of these neurons, implying that slit is exported by the glia and distributed along the axons. Finally, we demonstrate that a reduction in slit expression results in a disruption of the developing midline cells and the commissural axon pathways. The embryonic localization, mutant phenotype, and homology of slit to both receptor-binding EGF-like ligands and adhesive glycoproteins suggest that it may be involved in interactions between the midline glial cells, their extracellular environment, and the commissural axons that cross the midline.

Alleles↗

PubMed1991

Design and evaluation of closed-loop feedback control of minimum temperatures in human intracranial tumours treated with interstitial hyperthermia.

The dynamic nature of blood flow during hyperthermia therapy has made the control of minimum tumour temperature a difficult task. The paper presents initial studies of a novel approach to closed-loop control of local minimum tissue temperatures utilising a newly developed estimation algorithm for use with conductive interstitial heating systems. The local minimum tumour temperature is explicitly estimated from the power required to maintain each member of an array of electrically heated catheters at a known temperature, in conjunction with a new bioheat equation-based algorithm to predict the 'droop' or fractional decline in tissue temperature between heated catheters. A closed loop controller utilises the estimated minimum temperature near each catheter as a feedback parameter, which reflects variations in local blood flow. In response the controller alters delivered power to each catheter to compensate for changes in blood flow. The validity and stability of this estimation/control scheme were tested in computer simulations and in closed-loop control of nine patient treatments. The average estimation error from patient data analysis of 21 sites at which temperature was independently measured (three per patient) was 0.0 degree C, with a standard deviation of 0.8 degree C. These results suggest that estimation of local minimum temperature and feedback control of power delivery can be employed effectively during conductive interstitial heat therapy of intracranial tumours in man.

Adult↗

PubMedDate not supplied

Insonation of fixed porcine kidney by a prototype sector-vortex-phased array applicator.

The sector-vortex applicator, an ultrasound phased array with a geometric focus having multiple sectors and tracks, can directly synthesize, without scanning, diffuse focal patterns useful for hyperthermia. A perfused tissue phantom, consisting of an alcohol-fixed porcine kidney with thermocouples placed in the cortex, is insonated by a prototype sector-vortex applicator with 16 sectors and two tracks at an ultrasound frequency of 750 kHz. Steady-state temperature distributions are measured for a wide range of perfusion rates. Results demonstrate that the radius of the heated region can be controlled effectively by choosing the focal mode of the applicator as it is predicted by theoretical analysis.

Animals↗

PubMedDate not supplied

[Ultrastructural demonstration of the human papilloma virus (HPV) in oral proliferative lesions].

The Human Papilloma Virus (HPV) has been found in a series of benign proliferative lesions of the skin and mucosa. The virus has also been found in verrucous laryngeal carcinoma and carcinomas of the oral cavity and other organs. DNA hybridization techniques have made it possible to classify 51 types of HPVs, some appearing to be associated with specific lesions. In order to study the intracellular distribution of HPVs, an ultrastructural morphological analysis was performed with an electron microscope on 10 specimens taken from 5 patients. The specimens were obtained through large excisional biopsy, histologically classified as "fibropapilloma". For each patient specimens were taken from the clinically evident lesion and from the surrounding clinically normal mucosa. The specimens were fixed in glyceraldehyde, washed in a cacodylate buffer, post-fixed in potassium ferrocyanide reduced-osmium tetroxide, stained with uranyl acetate and included in EPON 812. The tissue was subjected to amylase digestion prior to electron microscope examination. A great number of viral particles were found in both the nucleus and the cytoplasm, without forming crystal array structures as typically described for the verruca vulgaris virus (HPV-2). No significant differences could be found between the cells derived from the clinical lesion and those derived from the surrounding mucosa. The passage of viral particles from infected to as yet uninfected cells through the intercellular space could be seen. The high intracytoplasmatic presence of the virus, and its clear abundance in those cells surrounding the clinical lesion, is felt to be of special interest.

Adult↗