Growth of homotransplanted ear cartilage in baby rabbits.
Our study verifies that homografted ear cartilage in baby rabbits does, indeed, grow in size. It showed an average increase of 75 percent in length and 211 percent in area.
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Our study verifies that homografted ear cartilage in baby rabbits does, indeed, grow in size. It showed an average increase of 75 percent in length and 211 percent in area.
The velocity vector field of the growing rabbit ear cartilage has been investigated between 12 and 299 days. Empirical curves have been computed for path lines and for velocities between 12 and 87 days. The tissue movement has been found to behave as an irrotational flow of material. Stream lines and velocity equipotential lines have been calculated and provide akinematic description of the changes during growth. The importance of a knowledge of the velocity vector in physical descriptions of growth and morphological differentiation at the tissue and cellular levels is emphasized.
The stimulatory effects of N6, O2'-dibutyrl adenosine 3',5'-monphosphate on proteoglycan released from immature rabbit ear cartilage were studied in viltro. Cartilage incubayed in medium containing dibutyryl cyclic AMP resulted in a significant increase of proteoglycans released in concentrations above 0.5 mM. Theophylline (1 mM) which did not significantly stimulate proteoglycans released alone, was found to potentiate the action of this nucleotide. ATP, 5'-AMP and butyric acid in the presence of theophylline, did not stimulate proteolgycans released. The addition of protein or RNA synthesis inhibitors depressed proteoglycans released by dibutyryl cyclic AMP and theophylline. Gel chromatogrphic and chemical investigation of the proteoglycans released into the culture media in the presence of dibutylic cyclic AMP indicated a reduction in the proportion of protein associated with these complexes. This result, together with enzyme inhbitor studies, leads us to speculate that the observed action of dibutyryl cyclic AMP on rabbit ear cartilages may be mediated by the neutral proteases.
Light microscopic and for the first time electron microscopic (EM) studies of involved elastic ear cartilage in a patient with relapsing polychondritis confirm the superficial location of the inflammatory reaction. EM studies of deep cartilage were identical to those on controls except for a rare necrotic cell. Superficial cartilage showed a finely granular electron-dense material. This material, which may be protein, possibly of enzyme or immunoglobulin origin, also surrounded some elastic fibrils. Findings of predominantly superficial changes and the multisystem disease in the present patient and in many others suggest that the cartilage destruction is part of a systemic inflammatory disease.
We describe the correction of lower eyelid ptosis in patients with an anophthalmic orbit, using ear cartilage grafts. This procedure has been particularly useful in the scarred or previously reconstructed lower eyelid.
We present our experience in the treatment of secondary nasal deformities caused by excessive resection of the nasal dorsum. We have used ear cartilage autografts, with good results and (on the whole) little or no resorption (some have been followed for 10 years). We consider it essential to correctly shape the transplant and to hold it firmly in the proper position for a period of not less than one week.
Six month after laryngectomy with a neoglottis phonatoria (Staffieri) one patient developed increasing trouble when swallowing liquids. When the patient was operated on again, the upper end of the trachea was closed up to a small anterior opening, by turning the lateral parts of the trachea into the lumen with dexon sutures. On this material cartilage from the ear was transplanted (because of the missing epiglottis) and covered with a free transplant of mucosa from the pharynx underneath the Staffieri fistula. After this second stage operation the patient had no more trouble when swallowing liquids and he developed again a good voice.
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Electron microscopic autoradiography of connective tissue obtained from mice and rabbits previously injected with 35SO4 indicated that sulphated proteoglycans are localized on collagen fibrils. Ruthenium Red-positive transverse belts surrounding fibrils near the a-bands were heavily labelled, but fine lateral filaments of Ruthenium Red-positive material were not. These filaments, which interconnect collagen fibrils in a variety of connective tissues may represent linear aggregations of hyaluronic acid, glycoproteins and non-sulphated or long-lived sulphated proteoglycans.
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Stiffening and tenderness of the helix of the ear, with radiologically demonstrable calcific deposits, has been reported in various conditions such as frostbite, and also in Addison's disease. To a total of 14 clinical observations with only 4 well documented cases, a first autopsy report of the disorder in a case of tuberculosus Addison's disease is added. It is shown that the elastic cartilage of the pinna, of the epiglottis and of the trachea undergoes ossification without preceding dystrophic or metastatic calcification. The ossification has been observed only in males with longstanding Addison's disease treated exclusively with mineralocorticoids over a long period. The possible pathogenetic mechanisms are discussed. An important factor seems to be the long-standing glucocorticoid deficiency.
The clinical course of the recurrent auricle cartilage inflammation was described. In Polish literature there were only 4 cases published. The etiopathogenesis, symptomatology and treatment were described.
Bovine ear cartilage contains more hyaluronic acid than do hyaline cartilages of the same animal. Most of it is in the elastin-rich residue not extractable by 4 M guanidinium chloride where it is associated with chondroitin sulphate in low relative concentration and of lower molecular weight than in non-elastic cartilage residue.
Chondrocytes were isolated enzymatically from rabbit ear cartilage, grown in vitro or as autotransplants for 1, 2 or 5 weeks and then examined by transmission electron microscopy. A confluent monolayer formed rapidly in vitro and the cells later grew in multiple overlapping layers, producing thick sheets of cartilaginous tissue. The cells retained a normal structure throughout the period of observation and, like the chondrocytes in intact cartilage, showed numerous microfilaments, and extensive granular endoplasmic reticulum and a prominent Golgi complex. Large amounts of intercellular matrix were laid down in vitro consisting of thin collagen fibrils, small rounded or polygonal granules believed to represent proteoglycans and patches and fibres of elastin. Chondrocytes in intramuscular autotransplants reconstituted an elastic cartilage. The exogenous origin of the cells in the transplants was verified by labeling of the lysosomes by exposure of the cells to colloidal thorium dioxide particles prior to injection. Structurally, the cells and the matrix of the transplants conformed to the above description. Accumulations of elastin-like material were sometimes observed in the Golgi vacuoles of the cells. Extracellularly, such conglomerates aggregated in connection with bundles of microfibrils, building up mature elastic fibres with a dense amorphous structure. The culture and transplant systems characterized here provide suitable experimental models for studies on development, growth and aging of elastic cartilage, including various aspects of the formation and turnover of elastic fibres and other macromolecular matrix components.
Possible interrelationships of copper-deficient (copper-deficient ration) and hypothyroid (thiouracil treatment) states in rats were examined. Clinical signs, necropsy changes, and thyroxine concentrations were determined in 6 groups of rats treated as follows: group A--nontreated control; group B--thiouracil treated; group C--fed copper-deficient ration; group D--thiouracil treated and fed copper-deficient ration; group E--thyroid-stimulating hormone (TSH) treated; and group F--TSH treated and fed copper-deficient ration. Clinical signs occurred first and were most severe in the thiouracil-treated rats fed copper-deficient ration and included conformational changes and slower maturation, weakening of ear cartilage, middle ear changes (reflected by tilting of heads), and alopecia. Fatty infiltration of hepatic tissue was found in all rats fed copper-deficient rations, and considerable fluid retention occurred in rats fed copper-deficient ration and subjected to daily TSH treatment. Adrenal gland weights were 81% of control values (adjusted for body weight) in thiouracil-treated rats fed copper-deficient ration, and hypophysis weights were 114 and 154% of control values in thiouracil-treated rats and thiouracil-treated rats fed copper-deficient ration, respectively. Thyroid gland weights were 281% of control values in both thiouracil-treated rats and thiouracil-treated rats fed copper-deficient ration. Plasma thyroxine concentrations were markedly reduced (9% of control value) in thiouracil-treated rats fed copper-deficient ration. Thus, copper-deficient and hypothyroid states were considerably enhanced when the 2 existed concurrently, giving added meaning and necessity to close surveillance of trace mineral concentrations and thyroid gland status.
Level lines of the specific growth rate and field lines of the gradient of the specific growth rate of developing ear cartilage have been computed. A single centre of maximum specific growth rate occurs in the midline and moves with time from the tip towards the base. Its movement is consistent with the progressive increase in area of the ear cartilage and with its consequent changes in form. The relationships of the centre for maximum specific growth rate to other maxima for the rates of production of cellular material, intercellular material, cell surface area and for material derivatives of intercellular volume fraction, cell volume fraction and cell surface density are discussed.
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Because increased uptake of 99mTc-diphosphonate (ethane-hydroxy-1, 1-diphosphonate) occasionally occurs in the anterior neck region, the possible increased affinity of the diphosphonate bone-scanning agent for cartilage was investigated. In vivo scintigraphic studies and organ analyses from rats and rabbits injected with this bone scintigraphic agent were performed. Trachea-to-muscle uptake ratios were a high 45:1 in adult Sprague-Dawley rats and approached the femur-to-muscle ratio of 93:1. Technetium-99m-diphosphonate uptake was also increased, but to a lesser extent, in xiphoid cartilage, tendon, and ear cartilage; this was proportional to the calcium content of the organ. The thyroid showed a high affinity for free pertechnetate but not 99mTc-diphosphonate, providing further evidence that the increased neck uptake of this 99mTc-diphosphonate is due to tracheal, not thyroid activity. In addition, premedication of three patients with 200 mg of potassium-perchlorate did not block this neck uptake. Interpretation of scintigraphs performed with 99mTc-diphosphonate that show lesions in the cervical spine should take into account the potential for false-positive readings caused by this increased tracheal uptake.