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At least 37 records · Page 2Linked to original sources
PubMed1978

Fatigue-induced damage in glutaraldehyde-preserved heart valve tissue.

Glutaraldehyde-preserved porcine mitral leaflet tissue has been subjected to extended accelerated fatigue loading in Ringer's solution containing 0.15% glutaraldehyde. Five tissue test pieces were subjected to cyclic tensile stresses of 50 and 200 Gm. per square millimeter and to 300 million to 800 million accumulated fatigue cycles. Tissue disruption occurred in each of the fatigued test pieces. Tensile loading, apart from reducing the acuteness of the collagen waveform and thereby decreasing tissue compliance, does not contribute significantly to the disruption process nor its rate of occurrence. Compressive flexure occurring during the unloading half of the fatigue cycle, however, does induce damage in the tissue. Mechanisms involved in the disruptive processes have been identified by conducting simultaneous morphologic and stress/strain observations on both the fatigued and unfatigued tissues in their wet functional condition. This vulnerability of the preserved tissue to compressive flexure could well affect the long-term durability of the glutaraldehyde-preserved heterograft valve, and this possibility is discussed in relation to the clinical use of these valves.

Animals↗
PubMed1978

Assessment of a tissue transport-medium in preservation of tissue-fixed immunoglobulins and complement demonstrated by direct immunofluorescence. A pilot study with skin from SLE patients.

The present work was undertaken in order to test the value of a tissue transport-medium (Histocon) for direct immunofluorescence studies. For this purpose one skin biopsy was performed on each forearm of 26 patients with systemic lupus erythematosus. One of the specimens was left in ice-cold Histocon solution for 4, 8, or 20 hours, and the other was immediately quick-frozen. The results of the immunofluorescence tests with the two methods yielded similar results. It is concluded that the solution allows the preservation of tissue-fixed immunoglobulins and complement during short periods of transport.

Adult↗
PubMed1979

Donor cornea contamination with McCarey-Kaufman medium preservation.

A patient had corneal infection with Staphylococcus aureus after keratoplasty from tissue preserved in McCarey-Kaufman medium. The small, successfully treated corneal infection was from the same organism cultured from the tissue culture medium at the time of transplantation. Possible sources of donor-tissue contamination included the increase in ocular flora seen in postmortem eyes, blood-borne bacteria, lack of sterile technique in securing donor tissue, inadequate irrigation of the tissue, and inadequate use of topical antibiotics on the tissue. Preservation medium and specimens from medium-preserved and refrigerated corneas should be cultured before and during surgery.

Administration, Topical↗
PubMed1979

Penetrating keratoplasty using McCarey-Kaufman preserved corneal tissue.

Two hundred consecutive penetrating keratoplasties, using suitable donor corneas stored in modified tissue culture medium (M-K medium), were performed by a single surgeon over a 21-month period. Two hundred consecutive cultures of the donor corneosclearl rims for aerobic and anaerobic bacteria and fungi, done immediately after surgery, yielded 25 positive cultures for aerobic and anerobic bacteria and three for fungi. No clinical infections nor primary donor failures were encountered with patients after one to 21 months of follow-up. Preservation of excised corneas by trained technicians, under rigidly sterile, laminar-flow, tissue culture conditions appears to be a convenient, safe, and effective method of corneal preservation which permits elective keratoplasty.

Adolescent↗
PubMed1975

[Transplantation and preservation of tissue-typized skin in burns].

At the Department of Plastic Surgery and Burns, Berufsgenossenschaftliche Unfalklinik Ludwigshafen-Oggersheim, a skinbank with typed skin has been established. The storage system consists of deep-freezing at -196 degrees C in liquid nitrogen. The transplantation of HL-A typed skin was evaluated from the clinical and histological point of view. Due to the effort necessary for such an undertaking this method is critically reviewed.

Burns↗
PubMed1977

Computerized tomography of in vitro abdominal organs--effect of preservation methods on attenuation coefficient.

The effect of formalin, freezing, and refigeration on the attenuation coefficient of fresh abdominal tissue of rhesus monkeys and dogs was investigated over a 1-week period. These techniques were used individually and in combinations designed to simulate circumstances involved in future in vitro investigations of human specimens. Statistically significant alterations of attenuation coefficients were found to occur at all scanning times within the first week except for the first 48 hr of formalin storage. Refrigeration resulted in the largest alteration. The results indicate the attenuation coefficients of tissues preserved by these three methods may be altered and that the magnitude of the change will vary according to the preservation techniques, tissue, and duration between tissue death and scanning.

Animals↗
PubMed1978

Ultrastructural localization of nonheme celluar iron with ferrocyanide.

The Prussian blue reaction was evaluated at the ultrastructural level as a cytochemical method to identify ferric and ferrous iron in rat bone marrow and splenic macrophages. Satisfactory tissue preservation and staining were achieved after fixation for 1 hr in 3% glutaraldehyde and exposure for 30 min to Perls's ferrocyanide solution before routine osmication and embedding. The acid ferrocyanide solution formed cuboidal and irregular electron-opaque deposits which localized ferric iron in the macrophage siderosomes and hyaloplasm. When thin sections were directly stained with the acid ferrocyanide, the stain deposits were much less distinct. The size and number of cytes exhibited sparse evenly distributed stain deposits. Several cells displayed abundant precipitates on the inner surface of the plasmalemma. Prussian blue precipitates were occasionally seen in mitochondria and nuclear euchromatin. Although osmium tetroxide post-fixation improved tissue preservation, it did not enhance the density of the ferri-ferrocyanide precipitate. The ferrocyanide solution yielded cuboidal deposits also in clots impregnated with ferritin, and electron diffraction analysis confirmed the symmetrical crystal structure of these stain precipitates. Smaller irregular precipitates were formed in clots impregnated with FeCl3, or Fe2 (SO4)3 solutions, despite the equally interpreted as indicating that the iron hydroxide core or protein structure of ferritin and hemosiderin contributed to the formation of the ultrastructurally evident cuboidal precipitates, but were not necessary for the formation of a colored reaction product. The acid ferrocyanide solution failed to stain clots formed in FeCI2, CuCI2 or CuCI solutions. Staining with a ferricyanide solution identified only sparse foci of ferrous iron in some siderosomes. This study demonstrates that the Prussian blue reaction can be used ultrastructurally to localize iron cations bound to some nonheme iron binding proteins.

Animals↗
PubMed1978

Prostacyclin: a potentially valuable agent for preserving myocardial tissue in acute myocardial ischemia.

Prostacyclin, a potent, naturally occurring prostaglandin exerts a variety of cardiovascular and cellular actions of potential value in acute myocardial ischemia. These properties include the reduction of systemic blood pressure without changing heart rate, the lowering of coronary vascular and total peripheral resistance, the inhibition of platelet aggregation and the concomitant formation of thromboxane B2, and the reduction of the release of lysosomal enzymes.

Animals↗
PubMed1975

Postmortem fixation of human lungs for electron microscopy.

A simple method of lung tissue preservation immediately post mortem by transthoracic injection of stained glutaraldehyde is described. By repetitive injections at varying time intervals after death it can be shown qualitatively and quantitatively by morphometry that normal lung tissue shows good preservation for at least 8 hours, whereas autolysis sets in shortly after death in diseased lungs.

Autolysis↗
PubMed2026

Spatial Integration of Protein and Chromosomal States Reveals Early Copy-Number Changes and Genotype-Associated Immune Neighborhoods in Serous Ovarian Cancer Evolution.

UNLABELLED: Detecting chromosomal copy-number alterations together with protein-defined cell states in intact tissue is critical for understanding early clonal evolution and microenvironmental interactions in cancer. We developed ORION-FISH, which integrates high-plex tissue imaging with a morphology-preserving DNA fluorescence in situ hybridization (DNA-FISH) workflow and single-cell registration, yielding measurements concordant with clinical FISH. In high-grade serous ovarian carcinoma (HGSOC), ORION-FISH recapitulated known chromosomal changes while revealing subclonal heterogeneity missed by targeted sequencing. Applied to serous tubal intraepithelial carcinomas, precursors of HGSOC, ORION-FISH identified intermixed epithelial cells with MYC or CCNE1 copy-number gains, as well as concurrent alterations associated with distinct immune microenvironments. In addition, epithelial cells with MYC and CCNE1 copy-number gains were detected in morphologically normal fallopian tube epithelium, along with rare MDM4 increases across epithelial lineages. Together, ORION-FISH provides a framework linking chromosomal copy-number states to protein-defined phenotypes within preserved tissue architecture, enabling context-aware interrogation of early copy-number diversification at single-cell resolution. SIGNIFICANCE: We introduce ORION-FISH, a spatially resolved workflow integrating multiplexed protein imaging with DNA-FISH to map genomic alterations within intact tissues. Applying this approach to ovarian cancer precursors reveals early copy-number diversification and associations with the local immune context, providing a foundation for studying how genomic and microenvironmental states coevolve during tumor initiation.

Female↗
PubMed1979

Influence of fixation conditions on the performance of glutaraldehyde-treated porcine aortic valves: towards a more scientific basis.

To maintain optimum mechanical properties in glutaraldehyde-treated heart-valve tissue the full collagen crimp geometry originally present in the relaxed fresh tissue should be retained. By varying the pressure at which glutaraldehyde fixation is carried out, considerable alterations to this crimp geometry can be achieved. The mechanical stiffness of the preserved tissue is consequently affected, and this in turn has a striking influence on both the opening behaviour of the valve and the degree of strain localisation in the leaflet tissue. A pressure of 100 mmHg eliminated the collagen crimp geometry entirely, and this resulted in the formation of sites of local strain or kinks in the valve leaflets during opening. It is expected that this strain localisation phenomenon will influence the long-term fatigue durability of the treated tissue. Pressures even as low as 4 mmHg result in significant reductions of crimp geometry. Fresh valves should therefore be fixed under a positive head of pressure sufficient only to ensure that the leaflets seal along their coapting free margins. A pressure of less than 1 mmHg was sufficient to achieve this. Leaflets of the commercially available Hancock valve show features similar to valves fixed in glutaraldehyde at about 100 mmHg pressure.

Animals↗
PubMed1976

[Collagen synthesis, studied by sub microscopic methods in beta-propiolactone and in tendon homografts, preserved by gamma irradiation].

In dog experiments homologous tendos conserved in beta-propiolacton and by means of gamma-radiation have been transplanted by the authors. After the 1st, 3rd and 8th post-operative week various regions of the graft and the recipient tendon stump have been examined by means of light--, polarisation microscopic and electron microscopic method. The examinations have unanimously shown that the tendon grafts conserved in beta-propiolacton are reorganized quickly, within 8 weeks nearly completely besides hardly visible inflammatory reaction. In the meantime, the originally collagen fibrous framework is decomposed and on it a new collagen fibrous structure develops, and thus a new tendon--capable to function--is formed. On the other hand, the reorganization of the grafts conserved with gamma-radiation is protracted or it fails to occur, and cicatrization is observed. Some problems of the modern tissue preservation, the collagen synthesis occurring in the active fibroblasts, the secretion of the collagen precursory substance into the extracellulary space, as well as the formation, the structure and the constitution of the newly synthesized collagen fibres--forming the transplant--are discussed by the authors. The obtained results are demonstrated in light-, polarization microscopic and electron microscopic pictures.

Animals↗
PubMed1976

The endothelium of clear corneal transplants.

The endothelium of 36 clear penetrating keratoplasties, performed 1 to 19 years previously, was examined and photographed with the clinical specular microscope. There were fewer central endothelial cells in the transplants than in normal corneas. There was no significant correlation between graft endothelial cell density and corneal thickness, rejection episodes, the disease necessitating kertoplasty, or the method of donor tissue preservation. Corneas transplanted from younger donors to younger recipients had significantly more central endothelial cells. Transplanted corneas appeared to lose endothelial cells over a period of time, just as normal corneas do.

Adolescent↗
PubMed1979

Utilization of cadaver tissue for a scanning electron microscopic study of the insertion of the masseter muscle.

1. The generally poor state of soft tissue preservation that complicates observations by gross dissection and light microscopy posed no hindrance to scanning electron microscopic (SEM) studies of bone surface, because all of the soft tissues are chemically removed. 2. Specific and identifiable surface patterns representing locations of periosteal and fibrous muscle attachments can be readily observed in cadaver tissue with the SEM. 3. SEM observations confirmed earlier literature concerning the extent of periosteal and intraosseus attachments of the masseter muscle. The masseter muscle attached periosteally on the lateral surface of the mandible and along the inferior border. Just above the inferior border, a ridge of intraosseous attachment was noted. 4. The correlation of SEM observation of bone surface patterns with gross dissection and light microscopy demonstrated that SEM can be useful in determining the extent of muscle attachments in cadaver tissue even when the soft tissue is poorly preserved.

Adult↗
PubMed1978

The donor kidney: I. Morphology of adequate preservation.

The structure of the dog kidney can be preserved in hypothermic intracellular-type solutions, but after 6 hours the appearance of pathologic focal changes such as mild oedema, lesions of the cellular elements, podocyte heteromorphism, vacuolization, disintegration of the basal membrane and of the cytomembrane structrues and even cell degeneration, is unavoidable.

Alkaline Phosphatase↗