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At least 487 records · Page 27Linked to original sources
PubMed2004

Method for creating ideal tissue fusion in soft-tissue structures using radio frequency (RF) energy.

Bipolar radiofrequency (RF) energy can successfully seal vascular structures up to 7 mm by fusing collagen and elastin in the lumen. Valleylab has created a system to expand this technology beyond vessel sealing with the development of a closed-loop, feedback-control RF generator that closely monitors tissue fusion. This generator, operating with a loop time of approximately 250 micros, continuously adjusts energy output, creating optimized soft-tissue fusion through structural protein amalgamation. In the first study, RF energy was applied to canine lung using the new-generation generator and lung-prototype device. A lobectomy was completed, sealing the lobar bronchus, parenchyma, and pulmonary vasculature. Chronic performance of the seals was evaluated at necropsy on postoperative days 7 and 14. In a second study, RF energy was applied to porcine small intestine using the same closed-loop generator and anastomosis prototype device. Acute tissue fusion was assessed qualitatively for hemostasis and seal quality. Terminal tissue evaluation was completed on postoperative day 7 and analyzed histopathologically. Histopathology confirmed acute and chronic tissue fusion in both the lung and intestine. Normal pathological healing was substantiated by angiogenesis, granulation, and proliferation of fibroblasts. Preliminary studies using canine lung and porcine small intestine demonstrate the potential of this closed-loop generator for soft-tissue amalgamation. Advanced monitoring capabilities make this fusion system applicable in many soft-tissue structures with adequate collagen and elastin. Further investigation of potential surgical applications needs to be completed.

Anastomosis, Surgical↗
PubMed2004

[Improvement of protein preparation methods for bronchial epithelial tissues and establishment of 2-DE profiles from carcinogenic process of human bronchial epithelial tissues].

OBJECTIVE: To optimize the protein preparation methods for bronchial epithelial tissues, to establish two-dimensional gel electrophoresis profiles from different stages tissues of human bronchial epithelial carcinogenic process, and to provide a base for identifying carcinogenesis-associated proteins of lung squamous carcinoma. METHODS: After obtaining samples of the normal-metaplasia-dysplasia-carcinoma tissues of human bronchial epithelia, improved deoxycholate-trichloroaetic acid (DOC-TCA) precipitation was used to extract and purify the total proteins of bronchial epithelial samples. Immobilized pH gradient two-dimensional polyacrylamide gel electrophoresis (2-DE) was used to seperate the total proteins of the samples. After silver staining, ImageMaster 2-DE image analysis software was applied to analyze 2-DE images. RESULTS: The total proteins extracted with improved DOC-TCA precipitation was used to perform 2-DE. 2-DE patterns with high resolution and reproducibility from different stages were obtained. The average spots for normal epithelium, metaplasia, dysplasia and invasive carcinoma were 1190 +/- 63, 1 227 +/- 69, 1272 +/- 71 and 1326 +/- 82, respectively. One of the squmous metaplasia tissues was chosen and repeated 2-DE for 3 times. Averagely 1216 +/- 75 spots were detected among the 3 gels of metsplasia tissues and 1082 +/- 67 spots were matched. The average matching rate was 89.3% and protein spots in the 3 gels had a good reproducibility. The average position deviation of matched spots in different gels was 0.835 +/- 0.247 mm in IEF direction, and 0.921 +/- 0.104 mm in SDS-PAGE direction. CONCLUSION: Improved DOC-TCA precipitation is a proper method for protein sample preparation of bronchial epithelial tissues. The well-resolved, reproducible 2-DE profiles from different stage tissues of human bronchial epithelial carcinogenic process have been primarily established.

Bronchi↗
PubMed1991

Myocardial tissue fraction--correction for partial volume effects and measure of tissue viability.

We have compared two independent methods of correcting the systematic underestimation in measurements of myocardial radiotracer concentration due to wall motion and small transmural wall thickness in cardiac PET studies. The first technique was based on measurement of the tissue fraction by fitting 15O-labeled water dynamic PET data. The other technique involved the subtraction of the C15O-blood volume scan from the transmission data, producing an image of extravascular density. In normal myocardial regions, both values were observed to be about 60% of myocardial tissue density. The tissue fraction was approximately 10% larger than the extravascular density in normal tissue regions. The ratio of alpha/Dev indicates the proportion of the total extravascular tissue for a given ROI that is perfusable by water--independent of the partial volume effect. This ratio was confirmed to be the expected value in normal tissue regions but was reduced in regions of infarction. The use of 15O-water, C15O and transmission data may aid in the differentiation between perfusable and nonperfusable tissue in the infarcted myocardium.

Adult↗
PubMed1977

[Selective local hyperthermy of tumor tissue. Homogenized energy supply also to deep-seated tissues by high-performance decametric wave coil section plus dual system raster motion (author's transl)].

Based on results of selective tumor tissue hyperacidification and whole-body hyperthermy the paper deals with the advantages of local hyperthermy and gives a review of the various methods of energy supply for hyperthermy in living tissue. It follows a presentation of physical and biophysical fundamentals on selective local hyperthermy of tumor tissue by radiation, by r. f. rotational magnetic fields and by r. f. capacitor fields. Using a gelatine phantom for measuring the energy supply with the various modes of local hyperthermy it is then shown that it is solely the divergent rotational magnetic field which allows to substantially reduce the inhomogeneity of energy supply also in z-direction (increasing depth in body tissue) by introducing a relative raster motion of the applicator in x-y-direction (plane parallel to body surface). It is only the introduction of the x-y raster principle combined with a described dual system array (CMT Selectotherm System) which permits the high and rather homogeneous supply of thermal energy also to deep-seated tumor tissue in the patient without concomitant critical superheating of tissues near the skin. Finally the paper gives a theoretical derivation of the temperature profile for selective local hyperthermy of tumor tissue. With due consideration of heat dissipation by convection and conduction, this endeavour shows rather promising aspects for the therapeutic efficiency obtainable in each case of treatment.

Animals↗
PubMed1988

Sheep bronchoalveolar carcinoma: tissue associated protein complex (TAPC) in normal lung tissue and in the tumor differed quantitatively.

Sheep lungs experimentally and naturally affected by bronchoalveolar carcinoma were washed out exhaustively of soluble components by phosphate-buffered saline, pH 7.4 (PBS), followed by glycine buffer, pH 2.8 (GB), and then again by 1M KCl followed by PBS. The tissue matrix (TM) of the tumor-free region and the tumor-affected tissue were analysed separately by sodium dodecyl sulfate (SDS) polyacrylamide electrophoresis. Normal lung tissues obtained from normal sheep served as controls. Several protein fractions and fragments, identified in both the normal and the tumorous lung, have the molecular weight (MW) of 130,000-228,000, as compared with the major soluble tissue associated protein having MW of 70,000. Coomassie blue staining used in the SDS polyacrylamide system and alkaline phosphatase immunoreaction used in the Enzyme Linked Immunosorbant Assay (ELISA) showed tenfold increased concentration of the TAPC in the TM of the tumor tissue and in the blood of tumor-affected animals, respectively. Total concentration of the TAPC in the serum of tumor-affected animals was higher than in the normal. Immunofluorescent antibody test (IAT) detected the TAPC in the cytoplasm of tumor as well as in normal lung cells, and the study suggested that the TAPC reaches the peripheral blood during tissue destruction occurring at the tumor site, as observed by light and electron microscopy (LM and EM). The concentration of each of the TAPC fractions was higher in the tumor-affected sheep lung as compared with normal sheep lung. Antibodies prepared against the TAPC fractions were toxic to sheep lung cells in tissue culture. Tumor cells were more susceptible.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1986

Tissue levels, tissue angiotensin converting enzyme inhibition and antihypertensive effect of the novel antihypertensive agent alacepril in renal hypertensive rats.

Tissue levels, tissue angiotensin I converting enzyme (ACE) inhibition and hypotension were examined 20 min, 1, 5 and 14 h after oral administration of 1-[(S)-3-acetylthio-2-methylpropanoyl]-L-prolyl-L-phenylalanine (alacepril, DU-1219) (37.5 mg (92 mumol)/kg) or 1-[(S)-3-mercapto-2-methylpropanoyl]-L-proline (captopril) (20.0 mg (92 mumol)/kg) in renal hypertensive rats, using 14C-labeled compounds. Alacepril exerted a more gradual and more sustained antihypertensive effect than captopril. The maximal hypotension was observed 1 and 5 h after administration of captopril and alacepril, respectively. After administration of [14C]captopril, serum level reached the maximum at 20 min and then decreased rapidly. After administration of [14C]alacepril, serum level reached the maximum at 1 h and decreased more slowly than after [14C]captopril. Time course patterns of tissue levels were essentially in parallel with those of serum levels. Captopril exerted the maximal reduction of ACE activity in tissues 20 min after oral administration and thereafter, the reduction was diminished with time rapidly. [14C]Alacepril showed gradual reduction (the maximum at 1 h) and recovery of ACE activity relative to captopril. After oral administration of [14C]alacepril, tissue unbound fractions contained captopril and its derived metabolites while serum unbound fraction contained the intermediate metabolite desacetyl-alacepril (DU-1227) as well. Correlations between ACE inhibition and tissue levels and between changes in tissue ACE inhibition and in blood pressure with time after oral administration of the two agents were discussed. Furthermore, the direct comparison of alacepril and captopril was attempted by the difference in blood pressures and in ACE inhibitions induced after oral administration of the agents.

Angiotensin-Converting Enzyme Inhibitors↗
PubMedDate not supplied

Heat-labile prolactin immunoreactivity in normal human tissues: artifacts of peptide hormone radioimmunoassay in human tissues.

We recently demonstrated that a substantial proportion of the previously reported widespread distribution of human chorionic gonadotropin-like material in nonplacental normal human tissues is due to non-specific activity of tissue proteases (Adejuwon & Segal, 1984). The study was extended to another polypetide hormone, measured by the same general method of radioimmunoassay. Normal tissue samples of colon (n = 1) and testes (n = 5) obtained at surgery were analysed by a highly specific and sensitive radioimmunoassay (RIA) for human prolactin (hPRL). All tissues investigated appeared to contain immunoreactive hPRL-like material (6.7 +/- 5.3 ng/g weight, mean +/- s.d.) Heat at 55 degrees C for 15-20 min was found to have no effect on the immunoreactivity of purified hPRL. Exposure of normal tissues to these conditions was, however, found to completely eliminate the hPRL-like immunoreactivity. The factor present in these normal tissues giving positive radioimmunoassay results for hPRL is not identical to native hPRL. It may be due to tissue proteases interfering with the radioligand assay. True polypeptide hormone immunoreactivity must be distinguished from proteolytic activity by treatment with heat or protease inhibitor.

Colon↗
PubMed1986

[A study on the penetration of cefmenoxime into bile and gallbladder tissues and the pathological changes of inflamed tissues].

The penetration of cefmenoxime (CMX) into bile and gallbladder tissues was studied. A dose of 2 g CMX was given intravenously to each of patients with gallstones. Concentrations of CMX in the gallbladder tissues were 120.6 +/- 39.8 micrograms/g in normal tissues about 2 hours after the administration and 128.3 +/- 52.3 micrograms/g in inflamed tissues. The penetration of CMX into gallbladder tissue tended to decrease in proportion to the severity of inflammation, but the difference between the 2 groups, normal and inflamed tissues, were not statistically significant. The penetration of CMX into gallbladder tissue was presumed to increase in proportion to increase in the serum concentration of CMX. The result indicated that the achievement of high concentrations of CMX in the serum is important in the treatment of biliary tract diseases.

Adult↗
PubMed1976

Chemosurgery for skin cancer: fixed tissue and fresh tissue techniques.

Complete microscopical control of the excision of cancer of the skin is achieved by removing tissues layer by layer and examining the undersurface of each layer by means of frozen sections. If the cancer is extensive and complicated or if it is of a type readily spread over an excisional surface, the tissues are fixed in situ with zinc chloride prior to excision (chemosurgery, fixed tissue technique). If the cancer is not too extensive or complicated, the tissues are excised in the fresh, unfixed state (chemosurgery, fresh tissue technique). Both techniques are highly reliable; for example, in two consecutive series of basal cell carcinomas treated chemosurgically, the five-year rate of cure was 99.3% for the 9,351 lesions removed by the fixed tissue technique and 97% for the 127 lesions removed by the fresh tissue technique.

Biopsy↗
PubMed1982

Effect of histamine and bradykinin on lymph and tissue fluid composition in the rabbit hindlimb: evidence for two compartments in tissue fluid.

In the rabbit hindleg lymph and tissue fluid were collected before and during close intraarterial infusions of histamine (2.5 and 10 micrograms/min) or bradykinin (0.4 microgram/min). Protein concentration was higher in the tissue fluid than in the lymph. During the 2h of the experiment in the control animals protein concentration increased in the lymph and decreased in the tissue fluid. Lymph flow decreased in the controls and it was not significantly influenced by histamine but was in the majority of animals (14 of 20) grossly augmented by bradykinin. Lymphatic protein and LDH fluxes were increased both by bradykinin and histamine. In animals where the vasoactive agents failed to alter lymph flow LDH concentration in the lymph increased significantly without comparable changes in the tissue fluid. On the other hand, in experiments where lymph flow was increased lymphatic LDH activity decreased but the activity in tissue fluid remained unchanged. It is concluded that the interstitial fluid is composed of two compartments. Only the perivascular compartment of tissue fluid is drained directly by the lymph vessels and lymph is essentially a recent microvascular filtrate. The second compartment of the interstitial fluid in rinsing the cells and connective tissue fibres, it is parallelly coupled and in exchange with the perivascular compartment.

Animals↗
PubMed1996

mRNA expression of matrix metalloproteinases and tissue inhibitors of metalloproteinase in interface tissue around implants in loosening total hip arthroplasty.

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) play an important role in tissue destruction and remodeling. Nine samples of cement interface tissues from nine patients who had failed cemented total hip arthroplasty (THA) were obtained for revision of THA and analyzed on mRNA expression of MMPs and TIMPs. The preoperative serial radiographic examinations revealed an apparent clear zone around all implants. We excluded septic loosening as one of the factors affecting THA. Three samples were obtained from three different sites of the acetabular interface tissue in each patient. After extraction of total RNA from 27 samples, we used the reverse-transcriptional polymerase chain reaction (RT-PCR). mRNA of MMP-1, -2, -3, -9, and TIMP-1 and -2 was detected in the interface tissue. MMP-10 mRNA was not detected, yet MMP-1 and MMP-3 mRNA were commonly observed. TIMP-2 mRNA was also strongly expressed compared to TIMP-1. It was thus demonstrated that MMPs and TIMPs were produced locally in the cemented tissue of THA loosening. These findings may suggest that MMPs and TIMPs expressed around the implants play a critical role in the progression of aseptic loosening of THA.

Aged↗
PubMed2005

Chitosan particles agglomerated scaffolds for cartilage and osteochondral tissue engineering approaches with adipose tissue derived stem cells.

It is well accepted that natural tissue regeneration is unlikely to occur if the cells are not supplied with an extracellular matrix (ECM) substitute. With this goal, several different methodologies have been used to produce a variety of 3D scaffolds as artificial ECM substitutes suitable for bone and cartilage tissue engineering. Furthermore, osteochondral tissue engineering presents new challenges since the combination of scaffolding and co-culture requirements from both bone and cartilage applications is required in order to achieve a successful osteochondral construct. In this paper, an innovative processing route based on a chitosan particles aggregation methodology for the production of cartilage and osteochondral tissue engineering scaffolds is reported. An extensive characterization is presented including a morphological evaluation using Micro-Computed Tomography (microCT) and 3D virtual models built with an image processing software. Mechanical and water uptake characterizations were also carried out, evidencing the potential of the developed scaffolds for the proposed applications. Cytotoxicity tests show that the developed chitosan particles agglomerated scaffolds do not exert toxic effects on cells. Furthermore, osteochondral bilayered scaffolds could also be developed. Preliminary seeding of mesenchymal stem cells isolated from human adipose tissue was performed aiming at developing solutions for chondrogenic and osteogenic differentiation for osteochondral tissue engineering applications.

Adipose Tissue↗
PubMed2005

Bioscaffolds in tissue engineering: a rationale for use in the reconstruction of musculoskeletal soft tissues.

Bioscaffolds derived from animal tissues can be an appealing substrate to induce the formation of functional tissue (histogenesis) within the context of tissue engineering. Bioscaffolds obtained from the extracellular matrix not only contain collagen, which can provide mechanical support, but also include the required biologically active molecules that provide a stimulus for active tissue remodeling. Manufacturing, processing, and the tissue source of the biological scaffold affect the biologic outcome and are important in predicting the clinical results. This article discusses the merits and limitations of using bioscaffolds in soft tissue engineering.

Animals↗
PubMed2004

Acquired disorders of elastic tissue: part I. Increased elastic tissue and solar elastotic syndromes.

Elastic fibers in the extracellular matrix are an integral component of dermal connective tissue. The resilience and elasticity required for normal structure and function of the skin may be attributed to the network of elastic tissue. Advances in our understanding of elastic tissue physiology provide a foundation for studying the pathogenesis of elastic tissue disorders. Many acquired disorders are nevertheless poorly understood due to the paucity of reported cases. Several acquired disorders in which accumulation or elastotic degeneration of dermal elastic fibers produces prominent clinical and histopathologic features have recently been described. They include elastoderma, linear focal elastosis, and late-onset focal dermal elastosis and must be differentiated from better-known disorders, among them acquired pseudoxanthoma elasticum, elastosis perforans serpiginosa, and Favré-Racouchot syndrome. Learning objective At the conclusion of this learning activity, participants should understand the similarities and differences between acquired disorders of elastic tissue that are characterized by an increase in elastic tissue, as well as the spectrum of solar elastotic dermatoses.

Connective Tissue Diseases↗
PubMedDate not supplied

The effect of intermittent cold treatment on the adipose tissue of the cat. Apparent transformation from white to brown adipose tissue.

Young cats (Felis domestica), aged 10-13 weeks, were intermittently exposed to a temperature of -30 degrees C for two periods of 1 hr per day. Animals were sacrificed on the 7th day and adipose tissue from the perirenal, pericardial, axillary, interscapular, and subcutaneous-inguinal depots was examined by electron microscopy and analysed stereologically. All examined depots were morphologically changed after cold treatment. Adipose tissue of perirenal, pericardial, and axillary depots showed a greater decrease in lipid content than the interscapular and subcutaneous-inguinal depots, but other changes were similar. Compared to the control group, which consisted of typical white adipose tissue, the diameter of adipose cells examined after cold treatment was diminished, in extreme cases to 18 micron (from 75 micron in the control group). The number of capillaries per cell was doubled (as evaluated on semithin sections). The most dramatic changes were observed in the mitochondria. Their volume increased to 0.48 micron 3 (from 0.13 micron 3 in the control), and the surface density of mitochondrial cristae per mitochondrial volume increased to 50 micron 2/micron 3 (from 32 in the control). Pleomorphism in mitochondrial size and inner structure and the presence of intramitochondrial electron-dense bodies and crystalline structures led us to conclude that the cold stress induced an increase in the absolute number of mitochondria in the adipose cells. The adipose tissue after cold treatment thus morphologically resembled the brown adipose tissue of cold-acclimated rodents. This implies that the adipose tissue of young cats can change its morphology and function, depending on the requirements of the organism.

Acclimatization↗
PubMed2001

Tissue-specific expression of the human CYP19 (aromatase) gene in ovary and adipose tissue of transgenic mice.

In humans, the CYP19 (aromatase P450) gene is expressed in a number of tissues, including gonads, placenta, adipose tissue, skin and brain. The 5'-untranslated regions (UTR) of CYP19 mRNA transcripts in these tissues are encoded by different tissue-specific first exons, which are alternatively spliced onto a common site just upstream of the start of translation in exon II. In ovary, the 5'-UTR of CYP19 transcripts is encoded by exon IIa, which lies just upstream of exon II, while in adipose, the 5'-UTR of CYP19 transcripts is encoded by exon I.4, which lies >20 kb upstream of exon II. To map genomic sequences required for ovary- and adipose-specific CYP19 expression, fusion genes containing 2700, 278 and 43 bp of DNA flanking the 5'-end of ovary-specific exon IIa, or 348 bp of 5'- flanking DNA and 170 bp of adipose-specific exon I.4 were linked to the human growth hormone (hGH) gene, as reporter, and introduced into transgenic mice. We observed that CYP19(IIa):hGH fusion genes containing as little as 278 bp of exon IIa 5'-flanking sequence were expressed at high levels in an ovary-specific manner in transgenic mice, while the CYP19(IIa)(-43):hGH fusion gene was not expressed in any tissue. These results suggest that sequences between -43 and -278 bp upstream of exon IIa mediate ovary-specific CYP19 gene expression. In mice carrying the CYP19(I.4)(-348):hGH fusion gene, transgene expression was detected in skin and in mammary adipose, but not in any of the other tissues examined. These results indicate that genomic elements within -348 and +170bp of adipose-specific exon I.4 mediate adipose- and skin-specific CYP19 gene expression. Studies are in progress using transgenic mice to further define the response elements that mediate ovary and adipose-specific hCYP19 gene expression.

5' Untranslated Regions↗
PubMed1996

Forms of lipoprotein lipase in rat tissues: in adipose tissue the proportion of inactive lipase increases on fasting.

Previous studies have shown that the ratio of lipoprotein lipase (LPL) catalytic activity to LPL mass in tissues differs in different conditions, but it is not clear whether this occurs by a change in the catalytic efficiency of the LPL molecules, or because of a shift in the relation between active and inactive forms of the enzyme. To explore this, we have measured LPL activity and mass in detergent extracts of rat tissues. LPL specific activity was high and similar in heart, skeletal muscle, lung and brain. The liver had significantly lower specific activity, which is in accord with previous findings that the liver takes up and catabolizes LPL. The specific activity was also low in adipose tissue from fasted rats. When tissue extracts were applied to columns of heparin-agarose and eluted by a gradient of NaCl, a peak of active LPL was eluted at 1.0 M NaCl, but there was also a peak of inactive LPL protein, which was eluted at 0.6 M NaCl. In adipose tissue, LPL activity decreased by 70-80% during an overnight fast, whereas LPL mass decreased by only 20-40%. The mass ratio between inactive and active LPL, as separated by heparin-agarose chromatography, increased from 0.5 to over 2 during the fast. In hearts there was no significant difference between fed and fasted rats in total LPL activity, LPL mass or in the distribution between inactive and active forms. The results indicate that the relation between inactive (probably monomeric) and active (dimeric) forms of LPL is a target for post-translational regulation in adipose tissue.

Adipose Tissue↗
PubMed1989

Anionic salivary proteins associated with connective tissue disorders: sialated tissue kallikreins.

Parotid saliva was collected from 32 patients with rheumatoid arthritis, 10 with systemic lupus erythematosus, three with mixed connective tissue disease, 12 with progressive systemic sclerosis, two with primary Sjögren's syndrome, and four with Raynaud's syndrome. Tissue kallikreins were measured by radioimmunoassay, and saliva samples were subjected to isoelectric focusing followed by immunoblotting or silver staining. The results showed that the saliva of patients with connective tissue diseases contained increased amounts of immunoreactive tissue kallikrein. In addition, there was an increase in the multiple forms of anionic tissue kallikreins, resulting mainly from a shift in their distribution towards that of higher sialic acid content and lower isoelectric point. These changes were most obvious in patients with systemic lupus erythematosus. Novel or unusual glycosylation may explain the occurrence of increased amounts of anionic salivary proteins in connective tissue diseases.

Adolescent↗