Microencapsulation of pancreatic islets with canine ear cartilage for immunoisolation

Improving human islet transplantation is often limited by the shortage of donors and the side effects of immunosuppressive agents. If immunoisolation is properly used, it can overcome these obstacles. Because artificial materials are adopted in this technique, however, there are still multiple issues with biocompatibility and foreign body reactions. We developed a chondrocyte microencapsulated immunoisolated islet (CMI-islet) that allows living cells to act as the immunoisolating material. To manufacture CMI-islets for xenotransplantation, isolated rat pancreatic islets were placed on low cell-binding culture dishes. Subsequently, expanded canine auricular cartiage primary cells were seeded on these dishes at a high density and maintained in a suspended state via a shaking culture system. Morphological evaluations showed good islet viability and a clear progression of the islet- encapsulation events. When the cells were challenged with glucose, they were able to secrete sufficient insulin according to glucose concentrations. The CMI-islets responded better to the glucose challenge than did nude pancreatic islets and created better glucose-insulin feedback regulation. Moreover, insulin secretion into the culture medium was confirmed over a period of 100 days, showing the survival and secretory capacity of the CMI-islet cells. By microencapsulating pancreatic islets with recipient ear cartilage cells, long-term insulin secretion can be maintained and the response to glucose challenges improved. This new immunodelusion technology differs from other immunoisolation techniques in that the donor tissue is enclosed with the recipient's tissue, thus allowing the transplanted cells to be recognized as recipient cells. This microencapsulation method may lead to developing viable xenotransplantation techniques that do not use immunosuppressive drugs.

Risk factors for cartilage infections of the ear

BACKGROUND

Investigation and case-control study to identify risk factors in a large outbreak in 2003 of auricular chondritis associated with piercing.

METHODS

Epidemiologic, environmental, and laboratory (pulsed-field gel electrophoresis) investigation, and case-control study. Telephone interviews were conducted for 15 cases and 61 controls. Odds ratios were determined for risks of infection.

RESULTS

Of 15 confirmed cases, nine (60%) were hospitalized (median duration 4.4 days) and treated with intravenous/oral antibiotics. Cases required surgical treatment and multiple antibiotics. Risk factors for infection included piercing location and the use of a contaminated aftercare solution. Pseudomonas aeruginosa isolates, nine from patients and four from the aftercare solution, were indistinguishable by pulsed-field gel electrophoresis; one from the sink at the facility differed by two bands.

CONCLUSIONS

This study demonstrates the serious consequences of cartilage piercing, identifies specific risk factors for infection, and suggests the importance of implementation and assurance of safe procedures.

[Allograft antigenicity of human ear cartilage and effect of cell extraction on antigenicity]

OBJECTIVE

To study the allograft antigenicity of human ear cartilage and the effect of the cell extraction on antigenicity.

METHODS

The human ear cartilage was acellular by cell extraction with Triton X-100. Then the cartilage and the acellular cartilage were analyzed by anti-MHC-I immunohistochemical staining, the reaction of the peripheral blood mononuclear(PBM) cells to the cartilage and the acellular cartilage and the migration of the PBM cells toward the cartilage and the acellular cartilage.

RESULTS

The result of human ear cartilage was positive for the anti-MHC-I immunohistochemical staining, whereas that of the acellular cartilage was negative for the staining. The reactive proliferation of the PBM cells was more when they were co-cultured with human ear cartilage than that when they were cultured alone in vitro(P < 0.05), but the acellular cartilage did not show the same phenomena (P > 0.05); when the cartilage and the acellular cartilage were co-cultured with the PBM cells, the PBM cells migrated to the cartilage much more than that to acellular cartilage(P < 0.01).

CONCLUSION

Human ear cartilage has allograft antigenicity and its antigenicity can be removed by cell extraction with Triton X-100.

A case of multisymptomatic relapsing polychondritis in a 22-year-old woman

A case of multisymptomatic relapsing polychondritis in a 22-year-old woman. We report a case of a 22-year-old woman with relapsing polychondritis (RP)--a rare and little known systemic autoimmune disease characterised by episodic inflammation of cartilaginous structures (ear, nose, bronchi, trachea, larynx, ribs, cardiovascular system). This patient presents with a seven-year history, initiated by the saddle nose. The patient developed a multitude of symptoms: auricular chondritis, ocular symptoms, recurrent arthritis, respiratory complications (laryngotracheomalacia, bilateral vocal cord palsy), sensorineural hearing loss and enchondroma of the humeral bone. The examination of an auricle biopsy by an immunofluorescent method and a positive serum reaction from the patient to normal cartilage supported the immunological nature of relapsing polychondritis. Treatment consisted of orally administered prednisone and diaminodiphenylsulfone (Dapsone).

Molecular basis of type II collagen autoimmune disease: observations of arthritis, auricular chondritis and tympanitis in mice

A type II collagen autoimmune response results in arthritis, auricular chondritis and tympanosclerosis in humans and animals. The purpose of this study is to further define the molecular and pathogenic events involved in these lesions in rodents. Type II collagen fragment CB11-specific monoclonal antibodies induced lesions in joints, ear lobes and tympanic membranes. In immunized mice, the thickness of tympanic membranes increased to two- to fourfold normal size. Electron micrography showed that the arrangement of collagen fibers is irregular in both radial and auricular layers, containing fibroblasts, a homogeneous material resembling low-density cholesterol crystals and cell infiltration. The mice with auricular chondritis had lymphocytes expressing V beta-8 T cell receptor (TCR) in arthritic joints and lymphocytes expressing V beta-6 TCR in ear lobe lesions. A monoclonal antibody specific to the TCR V beta-8 subfamily suppressed the onset of arthritis. Sequence analyses of the V beta structure of TCR involved in the lesions confirm the immunohistologic study.

Immunopathogenesis of canine aural haematoma

Data are presented from 15 dogs with aural haematoma. The series included six Labrador retrievers and four golden retrievers and the mean age was 8.0 +/- 3.02 years. Five dogs had evidence of pruritic skin disease and five further cases had other concurrent disease. Haematology and serum biochemistry were normal in 12 and 13 of the 15 dogs, respectively. All dogs were Coombs' negative and serum antinuclear antibody had negative or low titres in all the 11 cases tested. Histopathological examination of biopsies from the affected ears revealed variable degrees of erosion of auricular cartilage with fibrovascular granulation tissue filling the cartilage defects. There was minimal perichondral inflammation. The biopsies were studied by immunohistochemistry for deposition of immunoglobulin G (IgG), immunoglobulin M (IgM) and complement C3. In one dog there was basement membrane zone deposition of IgG and in another there was focal interepithelial deposition of both IgG and IgM. The findings of this study do not support an autoimmune pathogenesis for canine aural haematoma, but suggest that an early immunological event may underlie the observed cartilage erosion.

Class II antigenicity of human cartilage: relevance to the use of homologous cartilage graft for reconstructive surgery

The presence and distribution of class II transplantation antigens was studied on fresh and Merthiolate-preserved human nasal, tracheal, auricular, and rib cartilage using monoclonal antibodies in an indirect immunoperoxidase method. Substantial class II antigen expression was found on cells of the superficial area of the perichondrium of the nasal, auricle, and tracheal cartilages. In contrast, cartilage tissue lacked cells with detectable class II antigens. Our results indicate that the host response to fresh cartilage graft is induced by class II antigens presented in the perichondrium. A complete disappearance of this class II antigenicity of perichondrium can be achieved by means of an adequate Merthiolate preservation.

[Antigenicity of the auricular cartilage and its modification by vital preservation. 1. Xenogeneic transplantation of human auricular concha cartilage to the rabbit]

By means of xenotransplantation of human auricular cartilage to rabbits tests were carried out to see, if antigenicity is reduced through storing elastic cartilage either in a nutrient solution (Ham F 12) at 4 degrees C above zero or in a tissue culture (Ham F 12 + 10% serum of a calf-foetus) at 37 degrees C above zero, and if vital preservation prevents degeneration- and resorption processes of cartilage. The results were compared to transplants of fresh, not treated cartilages, and those preserved with cialit and merthiolate. It turned out that these vital preservation methods seem to cause an extensive loss of the cartilages characteristic qualities and that they keep degeneration- and resorption processes at a minimal level. Big differences between storage in nutrient solution and tissue culture could not be observed.

[Effect of glutaraldehyde on the species-specific antigenicity of xenogeneic cartilage]

Present results showed that an extract of xenogeneic cartilage may inhibit the complement activity of human serum, while an extract of xenogeneic cartilage treated with glutaraldehyde may enhance this effect. This finding suggested that treatment with glutaraldehyde does not decrease species-specific antigenicity of xenogeneic cartilage.

Relapsing polychondritis. Immunomicroscopic findings in cartilage of ear biopsy specimens

Two cases of relapsing polychondritis are reported. Direct immunofluorescence examination of ear biopsy specimens in both patients showed the presence of granular deposits of immunoglobulins and the C3 component of complement at the chondrofibrous junction. These findings suggest that immunomicroscopic examination of ear cartilage could be diagnostically useful in this disease.