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At least 55 records · Page 3Linked to original sources
PubMed1984

Analysis of collagen types synthesized by rabbit ear cartilage chondrocytes in vivo and in vitro.

This study compares the collagen types present in rabbit ear cartilage with those synthesized by dissociated chondrocytes in cell culture. The cartilage was first extracted with 4M-guanidinium chloride to remove proteoglycans. This step also extracted type I collagen. After pepsin solubilization of the residue, three additional, genetically distinct collagen types could be separated by fractional salt precipitation. On SDS (sodium dodecyl sulphate)/polyacrylamide-gel electrophoresis they were identified as type II collagen, (1 alpha, 2 alpha, 3 alpha) collagen and M-collagen fragments, a collagen pattern identical with that found in hyaline cartilage. Types I, II, (1 alpha, 2 alpha, 3 alpha) and M-collagen fragments represent 20, 75, 3.5, and 1% respectively of the total collagen. In frozen sections of ear cartilage, type II collagen was located by immunofluorescence staining in the extracellular matrix, whereas type I collagen was closely associated with the chondrocytes. Within 24h after release from elastic cartilage by enzymic digestion, auricular chondrocytes began to synthesize type III collagen, in addition to the above-mentioned collagens. This was shown after labelling of freshly dissociated chondrocytes with [3H]proline 1 day after plating, fractionation of the pepsin-treated collagens from medium and cell layer by NaCl precipitation, and analysis of the fractions by CM(carboxymethyl)-cellulose chromatography and SDS/polyacrylamide-gel electrophoresis. The 0.8 M-NaCl precipitate of cell-layer extracts consisted predominantly of type II collagen. The 0.8 M-NaCl precipitate obtained from the medium contained type I, II, and III collagen. In the supernatant of the 0.8 M-NaCl precipitation remained, both in the cell extract and medium, predominantly 1 alpha-, 2 alpha-, and 3 alpha-chains and M-collagen fragments. These results indicate that auricular chondrocytes are similar to chondrocytes from hyaline cartilage in that they produce, with the exception of type I collagen, the same collagen types in vivo, but change their cellular phenotype more rapidly after transfer to monolayer culture, as indicated by the prompt onset of type III collagen synthesis.

Animals↗
PubMed1981

Light and electron microscopic study of ear cartilage in a case of relapsing polychondritis evolving under corticoid treatment.

Light and electron microscope studies of the ear cartilage in a patient with relapsing polychondritis (RP) under corticoid treatment are reported. Unilateral auricular deformation evolved without inflammatory epidoses and the lesions consisted mainly of marginal erosions filled with fine collagen fibrils and containing degenerating perichondrial cells in their basal parts. Degenerative cells were scattered throughout the perichondrium, but cartilage erosions only occurred when numerous cells were affected in a same area. Cartilage outside the eroded zones did not seem to be modified. Cartilage lesions thus appear to be a result of a chondrocyte renewal defect leading to loss of proteoglycans and elastic fibers, with only collagen remaining. These data suggest that inflammation is probably not the initial pathogenic process responsible for cartilage injury in RP, but that a metabolic defect in perichondrial cells might be involved.

Adrenal Cortex Hormones↗
PubMed1990

[Ear cartilage as tarsus replacement (with long-term results)].

The authors report on 52 lid operations in combination with the transplantation of ear cartilage to serve as tarsus. The preoperative diagnoses were: ectropion (22); entropion (5); tumors (18); lid reconstruction following trauma (7). The long-term results were determined in 24 patients with 29 lids, with an average follow-up time of 26 months. The lid margin fit and the cartilage was palpable in nearly 90% of the long-term results; 83% of the patients were content with the cosmetic outcome.

Cartilage↗
PubMed1979

Ear cartilage grafts to the nose.

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.

Cartilage↗
PubMed1998

Endoscopic otoplasty in the rabbit model: effect of mechanical abrasion on ear cartilage deformation.

The purpose of this study was (1) to introduce an endoscopic technique for performing otoplasty; (2) to compare the durability of folding with scoring, sutures, or abrasion; and (3) to study the histologic changes associated with three techniques. Thirteen adult New Zealand White rabbits (26 ears) were divided into three otoplasty groups: bent cartilage (nine ears), cut cartilage (nine ears), or endoscopic abrasion of cartilage (eight ears). In all three groups, the ears were folded using external mattress sutures, with a transverse 180-degree fold. Sutures were removed at 1 to 6 weeks, and the ears followed for 4 weeks postoperatively. Ear-folding angles were followed weekly from suture removal to 4 weeks postoperatively. After sacrifice, the ear cartilage was harvested for histologic analysis. The ears were maintained in a 180-degree ventral fold by splinting sutures, which were removed at various times. Four weeks after suture removal, the mean ear angles were 13 degrees in the bent (control) group, 84 degrees in the cut group, and 132 degrees in the abraded group. The differences between the abraded and cut versus bent groups were significant (p = 0.0001 and 0.0073, respectively). There was no significant difference between the abraded versus cut groups. Histologic analysis showed perichondrial thickening on the convex surface in all of the groups. Fibrocartilage was produced in the cut and abraded groups. Based on histologic observation, the repair cartilage in the cut group was more fibrous, whereas that in the endoscopic group was more abundant with marked degenerative changes in the central zone. A new method of percutaneous endoscopic otoplasty in the rabbit model is described. This study showed that endoscopic otoplasty produced folding that was well maintained during the study period.

Animals↗
PubMed1970

The metabolic heterogeneity of rabbit ear cartilage chondroitin sulphate.

The only glycosaminoglycans that can be isolated from the ear cartilage of 2-month-old rabbits are chondroitin 4-sulphate and chondroitin 6-sulphate. These chondroitin sulphates exhibit molecular-weight polydispersity when isolated from tissue by papain digestion. The chondroitin sulphate is metabolically heterogeneous in that radioactive precursors [(14)C]glucose or [(35)S]sulphate are preferentially incorporated into the higher-molecular-weight polymers both in vivo and in vitro. No transfer of radioactivity from the high-molecular-weight chondroitin sulphate to the low-molecular-weight chondroitin sulphate was seen during 15 days in vivo. It is suggested that there are at least two pools of proteoglycan in the tissue. One of these pools is metabolically active whereas the other is not.

Animals↗
PubMed1978

[Valve-neoglottis by placing ear cartilage and mucosa on inverted lateral tracheal wall after liquid insufficiency of a Staffieri fistula (author's transl)].

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.

Cartilage↗
PubMedDate not supplied

Salvage of ear cartilage in patients with acute full-thickness burns.

Three cases in which the temporoparietal fascial flap was used to salvage denuded ear cartilage during the acute period after burn injury are reported. Patients' burns ranged from 30% to 75% total body surface area. The full-thickness burn was acutely excised, exposing the auricular cartilage. The temporoparietal facial flap was elevated and wrapped around the cartilage. The flap was then covered with a split-thickness skin graft. All flaps and skin grafts survived. Additional reconstructive procedures have been performed on two of the patients and are planned for the third.

Acute Disease↗
PubMed1996

Surgical treatment of lagophthalmos in facial palsy: ear cartilage graft for elongating the levator palpebrae muscle.

Ocular exposure, conjunctival irritation and corneal keratitis are disturbing consequences of facial paralysis with lagophthalmos. Many techniques have been described for correcting this condition. A new method for decreasing the palpebral fissure is presented. An ear cartilage graft is interposed between the tarsal plate and the levator palpebrae superioris muscle. 12 patients with paralysis of the orbicularis oculi muscle, as assessed by electromyography, were treated with this technique. The palpebral fissure was decreased by 2-3 mm in all cases. 11 patients showed significant improvement of their eye symptoms. One patient, in whom the palpebral fissure could not be closed sufficiently to protect the eye, required additional lengthening by 4 mm of the cartilage graft and a lateral tarsorrhaphy.

Adult↗
PubMed2005

Management of radiation-induced tracheocutaneous tissue defects by transplantation of an ear cartilage graft and deltopectoral flap.

Patients suffering from head and neck cancer often require temporary tracheostomy during therapy. The tracheostomy can usually be closed when postoperative swelling decreases and swallowing ability recovers. However, some patients, especially after adjuvant radiotherapy, may develop severe chronic wounds resulting in persistent tracheocutaneous fistula. Local wound care and plastic reconstruction strategies are required in such cases. We present two patients with head and neck cancer treated with primary surgical regimen including temporary tracheostomy and adjuvant radiotherapy. Both patients developed a persistent, poorly healing wound with persistent tracheocutaneous tissue defect. After local debridement and wound care, the peristomal necrotic tissue was excised down to the level of the trachea. The defect of the anterior tracheal wall was closed with a autogenous ear cartilage graft. The graft was harvested from the cavum conchae and sutured to the tracheal defect. The soft tissue defect was covered by transposition of a well-vascularized, fasciocutaneous deltopectoral flap. In both cases, the flaps healed satisfactorily. The donor defect was closed primarily. Complications were not observed in these two cases. A flexible tracheo-bronchoscopy showed no stenosis of the trachea at the site of cartilage graft transplantation. In conclusion, treatment of persistent radiated tracheocutaneous defects by cartilage graft and deltopectoral flap turned out to be a safe and reliable procedure which can be performed as a one-stage method with low morbidity at the donor site.

Cutaneous Fistula↗
PubMed2000

Nasal reconstruction using both cranial bone and ear cartilage.

In this article, an anatomic reconstruction is described using cranial bone graft for the bony part of the nose while reconstructing the cartilaginous part with ear cartilage. This modification provides protection of the nose from the traumatic forces creating a flexible nasal tip. A modification is described and compared with the nasal reconstruction by calvarial bone itself.

Adult↗
PubMed2000

Purification and some properties of UDP-xylosyltransferase of rat ear cartilage.

UDP-xylosyltransferase (UDP-D-xylose:proteoglycan core protein beta-D-xylosyltransferase EC 2.4.2.26) initiates the formation of chondroitin sulfate in the course of proteoglycan biosynthesis. The enzyme catalyzes the transfer of D-xylose from UDP-D-xylose to specific serine residues in the core protein. A procedure for purification of xylosyltransferase from rat ear cartilage was developed which includes ammonium sulfate fractionation, chromatography on heparin-agarose, on Sephacryl S300 and finally a substrate affinity chromatography applying the dodeca peptide Q-E-E-E-G-S-G-G-G-Q-G-G. The specific activity of the purified enzyme was about 420 mU per mg protein. The purification factor was about 26.000 with 27% yield. In SDS-polyacrylamide gel electrophoresis, the highly purified enzyme is homogeneous and yields only a single distinct band of 78 kDa. An apparent molecular mass of 71 kDa was determined for the native enzyme. These data suggest a monomeric structure for the enzyme. Xylosyltransferase activity was found to depend essentially on the presence of divalent metal ions. The K(m) value for UDP-D-xylose was determined to 6.5 micromol/l and for the dodeca peptide Q-E-E-E-G-S-G-G-G-Q-G-G as xylose acceptor to 8 micromol/l.

Amino Acid Sequence↗