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At least 91 records · Page 5Linked to original sources
PubMed1992

Different patterns of gene expression of topoisomerase II isoforms in differentiated tissues during murine development.

The expression of DNA topoisomerase II alpha and beta genes was studied in murine normal tissues. Northern blot analysis using probes specific for the two genes showed that the patterns of expression were different among 22 tissues of adult mice. Expression levels of topoisomerase II alpha gene were high in proliferating tissues, such as bone marrow and spleen, and undetectable or low in 17 other tissues. In contrast, high or intermediate expression of topoisomerase II beta gene was found in a variety of tissues (15) of adult mice, including those with no proliferating cells. Topoisomerase II gene expression was also studied during murine development. In whole embryos both genes were expressed at higher levels in early than late stages of embryogenesis. Heart, brain and liver of embryos two days before delivery, and these same tissues plus lung and thymus of newborn (1-day-old) mice expressed appreciable levels of the two genes. Interestingly, a post-natal induction of the beta gene expression was observed in the brain but not in the liver; conversely, the expression of the alpha gene was increased 1 day after birth in the liver but not in the brain. However, gene expression of a proliferation-associated enzyme, thymidylate synthase, was similar in these tissues between embryos and newborns. Thus, the two genes were differentially regulated in the post-natal period, and a tissue-specific role may be suggested for the two isoenzymes in the development of differentiated tissues such as the brain and liver. Based on the differential patterns of expression of the two isoforms, this analysis indicates that topoisomerase II alpha may be a specific marker of cell proliferation, whereas topoisomerase II beta may be implicated in functions of DNA metabolism other than replication.

Aging↗
PubMed2006

A comparative study of oxycodone and morphine in a multi-modal, tissue-differentiated experimental pain model.

Visceral pain can be difficult to treat with classical mu-opioid agonists and it has been suggested to use opioids with distinct pharmacological profiles. In animal experiments, oxycodone has shown different effects compared to morphine, and clinical observations have shown that oxycodone may occasionally be superior to, e.g., morphine in the treatment of visceral pain. In the current study, we randomised 24 healthy subjects to treatment with either morphine (30 mg), oxycodone (15 mg) or placebo in a crossover study. The experimental pain model involved multi-modal (mechanical, thermal and electrical) pain tests in the skin, muscles and viscera. The pain tests were carried out at baseline and 30, 60 and 90 min after oral administration of the drugs. The model showed effect of the two opioids compared to placebo on all stimulus modalities in all three types of tissues (all P values <0.001). Both opioids attenuated the sensory response mainly to painful stimulations. Morphine and oxycodone were equipotent in pain modulation of the skin and muscles, but oxycodone had superior analgesic effect to both morphine and placebo on the mechanical (P<0.001) and thermal (P<0.001) stimulations of the oesophagus. In conclusion, the multi-modal and tissue-differentiated pain model could link findings from animal experiments to clinical findings. A different pharmacological profile of oxycodone compared to that of morphine was shown, and thus oxycodone may be a useful alternative to morphine in the treatment of visceral pain syndromes.

Adult↗
PubMed2002

Isolation and differential tissue distribution of two human cDNAs encoding PDE1 splice variants.

A cDNA selection technique has been used to isolate full-length human cDNAs of the phosphodiesterase 1 (PDE1) calcium calmodulin (CaM)-regulated phosphodiesterase gene family. We isolated cDNAs representing multiple splice variants of PDE1A, 1B and 1C from a variety of tissues. Included among these were two novel splice variants for PDE1A and 1B. The first, PDE1A5, encodes a 519-residue protein, which is different from PDE1A1 by the insertion of 14 residues, a divergent carboxy terminus and also differs from PDE1A3 through a divergent amino terminus. Our second novel splice variant represents the first occurrence of a splice variant of the PDE1B gene. PDE1B2 encodes a 516-residue protein and diverges from PDE1B1 by the replacement of the first 38 residues by an alternative 18, which is predicted to be functionally significant. Using the splice variant sequence differences to perform comparative Northern analysis, we have demonstrated that each variant has a differential tissue distribution.

Alternative Splicing↗
PubMed1996

A novel gene family defined by human dihydropyrimidinase and three related proteins with differential tissue distribution.

We have isolated cDNA clones encoding dihydropyrimidinase (DHPase) from human liver and its three homologues from human fetal brain. The deduced amino acid (aa) sequence of human DHPase showed 90% identity with that of rat DHPase, and the three homologues showed 57-59% aa identity with human DHPase, and 74-77% aa identity with each other. We tentatively termed these homologues human DHPase related protein (DRP)-1, DRP-2 and DRP-3. Human DRP-2 showed 98% aa identity with chicken CRMP-62 (collapsin response mediator protein of relative molecular mass of 62 kDa) which is involved in neuronal growth cone collapse. Human DRP-3 showed 94-100% aa identity with two partial peptide sequences of rat TOAD-64 (turned on after division, 64 kDa) which is specifically expressed in postmitotic neurons. Human DHPase and DRPs showed a lower degree of aa sequence identity with Bacillus stearothermophilus hydantoinase (39-42%) and Caenorhabditis elegans unc-33 (32-34%). Thus we describe a novel gene family which displays differential tissue distribution: i.e., human DHPase, in liver and kidney; human DRP-1, in brain; human DRP-2, ubiquitously expressed except for liver; human DRP-3, mainly in heart and skeletal muscle.

Amidohydrolases↗
PubMed2002

Segmentation techniques for tissue differentiation in MRI of ophthalmology using fuzzy clustering algorithms.

This paper presents MRI segmentation techniques to differentiate abnormal and normal tissues in Ophthalmology using fuzzy clustering algorithms. Applying the best-known fuzzy c-means (FCM) clustering algorithm, a newly proposed algorithm, called an alternative fuzzy c-mean (AFCM), was used for MRI segmentation in Ophthalmology. These unsupervised segmentation algorithms can help Ophthalmologists to reduce the medical imaging noise effects originating from low resolution sensors and/or the structures that move during the data acquisition. They may be particularly helpful in the clinical oncological field as an aid to the diagnosis of Retinoblastoma, an inborn oncological disease in which symptoms usually show in early childhood. For the purpose of early treatment with radiotherapy and surgery, the newly proposed AFCM is preferred to provide more information for medical images used by Ophthalmologists. Comparisons between FCM and AFCM segmentations are made. Both fuzzy clustering segmentation techniques provide useful information and good results. However, the AFCM method has better detection of abnormal tissues than FCM according to a window selection. Overall, the newly proposed AFCM segmentation technique is recommended in MRI segmentation.

Algorithms↗
PubMed1997

The absence of accessible vitronectin receptors in differentiated tissue hinders adenoviral-mediated gene transfer to the intestinal epithelium in vitro.

PURPOSE: Adenoviral (Ad) vectors have been used as efficient tools for gene therapy in various tissues, whereas in some differentiated epithelium transduction efficiency is almost abolished. METHODS: Caco-2 cell monolayers were chosen as an in vitro model for the differentiated intestinal epithelium. Fluorescence-labeled adenoviral particles were used for binding studies to cell surfaces. Internalization receptors for adenoviral uptake were detected by a fluorescence-labeled vitronectin antibody. Gene expression was studied by using the beta-galactosidase reporter gene. All experiments were done on undifferentiated and differentiated Caco-2 cells. Furthermore, adenoviral particles were allowed to bind to differentiated Caco-2 monolayers followed by a trypsinization step that disintegrates the monolayers and result in a cell suspension. Gene expression was tested after reseeding the cells into dishes. RESULTS: The results from adenoviral binding studies, vitronectin immunofluorescence detection and gene expression are in good agreement and indicate that virion binding as well as the expression of internalization receptors almost disappear in fully differentiated cells. Nonetheless, adenoviral binding to differentiated monolayers seems to be sufficient to cause up to 53% gene expression, but only if internalization of the vector can be induced by disintegrating the monolayers and releasing free vitronectin receptors. CONCLUSIONS: These findings indicate that gene transfer to the intestinal epithelium utilizing adenoviral vectors is poor and ineffective, because of the lack of sufficient internalization receptors. If these receptors can be exposed in differentiated epithelium, transduction can be made more efficient. Alternatively, a viral vector must be developed whose uptake mechanism is independent of integrin receptor expression like the enteral virus Ad40, or Ad5 could be conjugated to ligands that trigger viral internalization by receptor-mediated endocytosis.

Adenoviridae↗
PubMed1991

The tissue distribution of rat chromogranin A-derived peptides: evidence for differential tissue processing from sequence specific antisera.

The distribution of chromogranin A and related peptides in rat tissues was investigated using sequence specific antisera. N- and C-terminal antisera and a presumptive C-terminal rat pancreastatin antiserum immunostained an extensive neuroendocrine cell population throughout the gastro-entero-pancreatic tract, anterior pituitary, thyroid and all adrenomedullary cells. However, mid- to C-terminal antisera immunostained a subpopulation of chromogranin A positive cells. Most notable of these was with the KELTAE antiserum (R635.1) which immunostained discrete clusters of adrenomedullary cells and antiserum A87A which immunostained a subpopulation of cells in the anterior pituitary and throughout the gastrointestinal tract. The present study has demonstrated the widespread occurrence of chromogranin A and related peptides in rat neuroendocrine tissues and provides evidence of tissue and cell specific processing.

Adrenal Medulla↗
PubMed1990

Differential expression of alternate forms of a Drosophila src protein during embryonic and larval tissue differentiation.

The Dsrc28C gene encodes two major proteins, p66 and p55, each of which contains a tyrosine kinase domain. Using monoclonal antibodies we have completed a detailed investigation of the spatial expression of Dsrc28C proteins during embryonic and larval development. Differentiation of a number of embryonic tissues is accompanied by the induction of Dsrc28C expression. With the exception of the developing salivary glands which express high levels of p66, developing tissues express the p55 form of Dsrc28C. Notable examples are cells of the and peripheral nervous systems which express p55 from the early stages of neurogenesis through the remainder of embryogenesis and pole cells which transiently express p55 during portions of embryonic stages 10 and 11. Nervous system expression includes the cell bodies and neuronal fibers of the central nervous system, the anterior sensory organs, and the peripheral sensory neurons. During larval development, p55 levels within the central nervous system remain high but substantial changes in the pattern of expression take place. p55 gradually disappears from the neuronal fibers of the central nervous system and from embryonic cell bodies. During the third larval instar, the birth of immature neuroblasts within the ventral and midbrain ganglia, but not within the optic ganglia, is marked by a transient high level of p55 expression. All imaginal cells that have been observed within the larva express the p66 protein. The patterns of expression that we have noted suggest that expression of the p55 form of Dsrc28C protein is an early event in the differentiation of neuronal cells, while expression of the p66 form is characteristic of cells committed to ectodermal cell differentiation.

Animals↗
PubMed1998

OP-1 has more effect than mechanical signals in the control of tissue differentiation in healing rat tendons.

Although osteogenic protein 1 (OP-1) is best known for its ability to induce bone formation, it is a differentiation factor with diverse functions in the development of non-bony tissues. It is expressed in developing tendon. We therefore hypothesized that OP-1 might stimulate the differentiation of a tendon callus. Rat achilles tendons were transected and a collagen sponge with or without OP-1 was placed in the defect. OP-1 induced the formation of an ossicle, which reduced tendon strength at 2 weeks postoperatively. Abolition of muscle force by tibial nerve transection or reducing load by forefoot amputation reduced tendon strength by almost half during the same period. Thus, traction forces are potent tendon-tissue inducers. OP-1 reduced the strength of denervated tendons even further, but the induced ossicles appeared similar to those in loaded tendons. Thus, both OP-1 and unloading independently reduced tendon strength. In conclusion, the ability of OP-1 to induce bone was greater that the mechanical and environmental signals for a more traction-resistant tissue, indicating that signal proteins may have more direct or stronger effects than mechanical stimuli on tissue differentiation. We also found that a single percutaneous injection of OP-1 reproducibly induced large amounts of bone in this setting, although it is generally believed that BMPs always need to be inserted with a carrier.

Achilles Tendon↗
PubMed1997

[Tactile sensor for tissue differentiation in minimally invasive ENT surgery].

BACKGROUND: In endoscopic surgery, stereoscopic vision and tactile information about tissue consistency are no longer available to the surgeon. METHODS: To compensate for these sensory deficits, various tissues can be characterized with an electromechanical sensor that records their resonance frequencies. In the future, the sensor will be integrated into surgical instruments, providing the surgeon with information about tactile properties of the tissue. We determined the impedance of tissues removed interoperatively (nasal polyps, lymph nodes, cartilage, bone) and different bony structures in a skull specimen. The examinations were carried out with an experimental setup and subsequently with a prototype of the tactile sensor. RESULTS: Resonance frequency increased with tissue hardness. Measurements with the experimental setup showed resonance frequencies for soft tissues between 15 and 30 Hz. We found that the bony septa of the ethmoid have a resonance frequency of 240-320 Hz and the thicker bony structures at the frontal skull base have a frequency of 780-930 Hz. Measurements of tumors in the upper aerodigestive tract showed that it is possible to differentiate between healthy mucosa, carcinomateous infiltrated mucosa, and carcinomateous undermined mucosa. In case of undermining tumor, the resonance frequency was one third higher than healthy mucosa. These results obtained with the experimental setup were reproduced with the tactile sensor prototype. CONCLUSIONS: The use of tactile information in endoscopic otolaryngological surgery may improve intraoperative tissue differentiation in the future. The safety of minimal invasive operations in head and neck surgery can be increased.

Endoscopes↗
PubMed2006

STAT1 in peripheral tissue differentially regulates homing of antigen-specific Th1 and Th2 cells.

Th1 and Th2 effector CD4+ T cells orchestrate distinct counterregulatory biological responses. To deliver effective tissue Th1- and Th2-type responses, Th1 and Th2 cell recruitment into tissue must be differentially regulated. We show that tissue-derived STAT1 controls the trafficking of adoptively transferred, Ag-specific, wild-type Th1 cells into the lung. Trafficking of Th1 and Th2 cells is differentially regulated as STAT6, which regulates Th2 cell trafficking, had no effect on the trafficking of Th1 cells and STAT1 deficiency did not alter Th2 cell trafficking. We demonstrate that STAT1 control of Th1 cell trafficking is not mediated through T-bet. STAT1 controls the recruitment of Th1 cells through the induction of CXCL9, CXCL10, CXCL11, and CXCL16, whose expression levels in the lung were markedly decreased in STAT1-/- mice. CXCL10 replacement partially restored Th1 cell trafficking in STAT1-deficient mice in vivo, and deficiency in CXCR3, the receptor for CXCL9, CXCL10, and CXCL11, impaired the trafficking of adoptively transferred Th1 cells in wild-type mice. Our work identifies that STAT1 in peripheral tissue regulates the homing of Ag-specific Th1 cells through the induction of a distinct subset of chemokines and establishes that Th1 and Th2 cell trafficking is differentially controlled in vivo by STAT1 and STAT6, respectively.

Adoptive Transfer↗
PubMed1987

S-100 protein immunostaining in teratomatous well-differentiated tissues.

The presence and distribution of S-100 protein were studied in a case of ovarian teratoma using avidin-biotin complex immunoperoxidase method. S-100 immunoreactivity within the well-differentiated teratomatous tissues appeared to mirror that of their normally developed human counterparts, although we could unexpectedly detect S-100 immunoreactivity in bone osteoblasts and osteocytes, and in tooth germ odontoblasts. Choroid plexus-like formations present in the teratoma were also positive. Our results suggest that the presence of S-100 protein might be associated with a basic cell function regardless of the presence of a physiologically end-developed human organism.

Female↗
PubMed1986

[Value of physical parameters and digital signal processing in tissue differentiation].

It was the aim of this study to improve tissue characterization using ultrasonic scatter signals and image processing procedures by computer. Analysis of various tissue probes and phantoms showed that structures can be differentiated by scatter as a function of frequency and angle of scatter. The application of this method as an imaging system was realised by a reconstruction algorithm to compute scatter images. By means of analysing images of the thyroid and prostate we found that the detection rate of computerised texture analysis is much higher than that of visual evaluation.

Diagnosis, Differential↗
PubMed1981

Accumulation of [3H]-ouabain in functionally different canine cardiac tissues: differential Rb+ uptake.

1 In order to understand tissue-specific differences in sensitivity to ouabain, the distribution of [3H]-ouabain was investigated in seven functionally different, canine cardiac tissues. 2 Specialized cardiac tissues (e.g., pacemaker or conducting tissues) accumulate much less ouabain than do the contractile tissues such as the left ventricle or the papillary muscle. 3 This study confirms a greater Rb+ uptake in the Purkinje fibre than in the contractile tissue. 4 The results disprove the hypothesis that a high accumulation of ouabain in the Purkinje fibre is responsible for the well-known sensitivity to ouabain in this tissue.

Animals↗
PubMed2002

Cells of the connective tissue differentiate and migrate into pollen sacs.

In angiosperms, archesporial cells in the anther primordium undergo meiosis to form haploid pollen, the sole occupants of anther sacs. Anther sacs are held together by a matrix of parenchyma cells, the connective tissue. Cells of the connective tissue are not known to differentiate. We report the differentiation of parenchyma cells in the connective tissue of two Gordonia species into pollen-like structures (described as pseudopollen), which migrate into the anther sacs before dehiscence. Pollen and pseudopollen were distinguishable by morphology and staining. Pollen were tricolpate to spherical while pseudopollen were less rigid and transparent with a ribbed surface. Both types were different in size, shape, staining and surface architecture. The ratio of the number of pseudopollen to pollen was 1:3. During ontogeny in the connective tissue, neither cell division nor tetrad formation was observed and hence pseudopollen were presumed to be diploid. Only normal pollen germinated on a germination medium. Fixed preparations in time seemed to indicate that pseudopollen migrate from the connective tissue into the anther sac.

Asteraceae↗
PubMed1979

[Electron microscopic study of the characteristics of skeletogenic tissue differentiation during distraction osteosynthesis].

Electron microscopic examination of the regenerating tissue was performed after distractional osteosynthesis carried out by the method of G. A. Ilizarov. The results showed osteogenesis to occur on the basis of the fibrous tissue formed in diastasis. The observed zones of the regeneration typical of distractional osteosynthesis are due to functional stimulation (tension) resulting in the arrangement of collagen fiber bundles and bone trabeculae in the direction of the extension forces. Cells of the skeletogenic tissue, between the bone fragments are also arranged with their longitudinal axis along the collagen fibril bundles. The ultrastructural pattern of the osteogenesis after distractional osteosynthesis reflects the intensification of the synthesis of glycosaminoglycan-protein complexes forming the main substance of the bone tissue.

Animals↗
PubMed1983

Orbital tissue differentiation with standardized echography.

The standardized A-scan (Kretztechnik 7200 MA) supplemented by contact B-scan and Doppler ultrasound is a time-tested, highly reliable, and noninvasive tool for the evaluation of patients presenting with signs or symptoms suggesting an orbital lesion. Diseases of the orbital adipose tissue, extraocular muscles, optic nerves and periorbital sinuses are detectable within minutes by the experienced examiner. More than 60 types of orbital lesions can then be differentiated, localized, measured, and schematized. While the value of orbital CT scanning has been widely accepted, standardized echography is now also being recognized as an important modality in the diagnosis and management of orbital and periorbital disease. The use of standardized echography results in more frequent and more accurate tissue differentiation, specifically: (1) standardized tumor patterns closely correlate with histologic diagnoses, (2) vascular flow detection and compression testing (hard or soft), (3) detection and diagnosis of optic nerve sheath distention due to increased subarachnoid fluid (eg, benign intracranial hypertension), and (4) greater sensitivity in detecting mild extraocular muscle thickening (eg, Graves' disease). Additional advantages are the noninvasive nature of the procedure (no radiation) and portability of the equipment.

Arteriovenous Fistula↗