[Benefits and risks associated to lithium use in psychiatry]. / Vignette thérapeutique de l'étudiant. Bénéfices et risques de l'utilisation du lithium en psychiatrie.

The goal of the article was to provide some clinical recommendations for a secure use of lithium. We described the mechanism of action of lithium, that acts as a mood stabilizer but also has anti-suicidal and neuroprotective effects. We also described the toxics effects of lithium and the toxicological tools that help to prevent and to treat those effects. We concluded that lithium remains a first choice for the treatment of bipolar disorders.

L'article fournit des recommandations cliniques pour utiliser le lithium de façon efficace et sûre. Nous décrivons les mécanismes d'action du lithium, stabilisateur de l'humeur aux propriétés antisuicidaires et neuroprotectrices. Nous détaillons les effets toxiques du lithium et les outils de toxicologie clinique qui permettent de les prévenir et de les diagnostiquer. Le lithium reste le traitement de référence des troubles bipolaires.

Spontaneous pneumothorax in cocaine users.

BACKGROUND: Pneumothorax is one of the respiratory toxic effects of cocaine inhalation. The literature counts several cases, some associated to other respiratory conditions such as pneumomediastinum, haemoptysis and others not requiring surgical treatment. AIM: We present a series of nonHIV cocaine-inhaler subjects who underwent video-assisted thoracoscopic surgery (VATS) for isolated spontaneous pneumothorax. DESIGN: Nine subjects, with a mean age of 24 ± 4 years, admitting cocaine inhalation, developed spontaneous pneumothorax and underwent 10 surgical treatments by means of VATS, at our Institution. RESULTS: Previous pneumothorax occurred in six cases episodes ranged from 0 to 5 (mean 1.6 ± 1.6). Chest computed tomography (CT) scan showed abnormalities in seven cases. All subjects underwent lung apicectomy, apical pleurectomy and mechanical pleurodesis. Seven subjects had also bullectomy. In all cases the visceral pleura was partially covered by fibrinous exudate. Histology of the lung showed small foreign body granulomatous inflammation in fibrotic and/or emphysematous pulmonary parenchyma. Relapse of pneumothorax occurred in one subject at 60 days and it was surgically treated. Mean follow-up was 150 ± 38 months (range 120-239). All subjects are now well, with no evidence of pneumothorax. CONCLUSIONS: Spontaneous pneumothorax in cocaine-inhaler subjects is a reality of which physicians need to be aware. Chest CT scan might not reveal abnormalities. Macroscopically the lung might presents bullae and/or peculiar visceral pleura. Foreign body granulomas observed in the specimens suggest that the particulate component of inhaled substances can injure the lung. Surgical treatment of the bullous disease and mechanical pleurodesis can provide a long-term follow-up without relapse of pneumothorax.

[Biological contamination by micromycetes in dried Boletus edulis: research of aflatoxin B1, B2 G1, G2 and ochratoxin A]. / Contaminazione da funghi filamentosi su Boletus edulis essiccato: ricerca di aflatossina B1, B2 G1, G2 e ocratossina A.

Aim of this survey is to identify those filamentous fungi which parasite Boletus edulis and its group and check the potential presence of secondary metabolites, specifically aflatoxin B1, total aflatoxins and ochratoxin A, in order to assess the risk to consumers' health. Forty samples of dried Boletus edulis, collected by two food industries which distribute the product in many Italian regions, have been analysed. The sampling plan has been conducted from November 2005 to March 2006, collecting 50 g from each commercial category of dried Boletus edulis available in the factory at the time of sampling. All the samples have been tested by visual macroscopic and stereoscopic assays; for some samples--those referred to commercial category presumably at higher risk--we have performed cultural assays as well, typization of isolated micromycetes, extraction and quantification of aflatoxins and ochratoxin A. Mycotoxin detection has been made by HPLC, using the UNI EN 14123 and UNI EN 14132 standard methods, respectively applied to aflatoxins determination in peanuts, pistachios, figs and paprika and to ochratoxin A in barley and coffee. Non pathogenic micromycetes, common in food products, have been frequently observed in cultural assays, while Aspergillus flavus and Aspergillus niger have been found in some samples. However the concentration of aflatoxins was always under the quantification limit. The survey confirm that, if the cold chain is kept throughout the process and the distribution, Boletus edulis and analogue mycetes are not a favourable substratum for the growth and the development of moulds.

Silk fibroin as an organic polymer for controlled drug delivery.

The pharmaceutical utility of silk fibroin (SF) materials for drug delivery was investigated. SF films were prepared from aqueous solutions of the fibroin protein polymer and crystallinity was induced and controlled by methanol treatment. Dextrans of different molecular weights, as well as proteins, were physically entrapped into the drug delivery device during processing into films. Drug release kinetics were evaluated as a function of dextran molecular weight, and film crystallinity. Treatment with methanol resulted in an increase in beta-sheet structure, an increase in crystallinity and an increase in film surface hydrophobicity determined by FTIR, X-ray and contact angle techniques, respectively. The increase in crystallinity resulted in the sustained release of dextrans of molecular weights ranging from 4 to 40 kDa, whereas for less crystalline films sustained release was confined to the 40 kDa dextran. Protein release from the films was studied with horseradish peroxidase (HRP) and lysozyme (Lys) as model compounds. Enzyme release from the less crystalline films resulted in a biphasic release pattern, characterized by an initial release within the first 36 h, followed by a lag phase and continuous release between days 3 and 11. No initial burst was observed for films with higher crystallinity and subsequent release patterns followed linear kinetics for HRP, or no substantial release for Lys. In conclusion, SF is an interesting polymer for drug delivery of polysaccharides and bioactive proteins due to the controllable level of crystallinity and the ability to process the biomaterial in biocompatible fashion under ambient conditions to avoid damage to labile compounds to be delivered.

Early pulmonary recurrence of non-Hodgkin's lymphoma after autologous marrow transplantation: evidence for reinfusion of lymphoma cells?

Disease recurrence is a major cause of failure after autologous bone marrow transplantation for Hodgkin's disease or non-Hodgkin's lymphoma. Relapse usually occurs at sites of previous involvement. The patient described here died of massive pulmonary involvement with Ki-1 antigen (CD30)-positive immunoblastic lymphoma 2 months after transplantation with unpurged autologous marrow. This relapse in a previously uninvolved organ prompted resectioning of the pre-storage marrow biopsy and resulted in identification of one small aggregation of malignant cells. A review of open lung biopsies and necropsies of autologous marrow recipients treated in Seattle identified no other patients with pulmonary malignancy who lacking previous lung tumor or evidence of contiguous pulmonary and mediastinal involvement. These observations raise questions about the assessment of pre-harvest marrow involvement and the need for marrow purging. This case also suggests that organ and tissue localization of malignant cells may be determined by abnormally expressed 'homing' ligands.

Autologous bone marrow transplantation in secondary acute monoblastic leukemia following Hodgkin's disease.

Acute non lymphocytic leukemia (AnLL) is the most common second malignancy (SM) in survivors of childhood Hodgkin's Disease (HD). Chemotherapy responsiveness is usually poor and death ensues briefly after diagnosis. We report the case of a 13 year-old girl, affected by HD, stage IV, mixed cellularity, who developed AnLL one year after the HD treatment was stopped. Autologous Bone Marrow Transplantation (ABMT) was performed 9 months after complete remission (CR) was achieved by chemotherapy. Presently, the patient is alive and on continues CR, 3 years and 7 months after ABMT. ABMT may be a promising approach for secondary AnLL, the prognosis of which is almost invariably fatal with conventional chemotherapy.

Autologous bone marrow transplantation in children with acute myeloblastic leukemia: report from the Italian National Pediatric Registry (AIEOP-BMT).

This report summarizes indications and results of autologous bone marrow transplantation (ABMT) performed in childhood acute myeloid leukemia (AML) in Italy since 1984. A total of 158 patients have been reported from 12 teams to the AIEOP-BMT Registry: 110 have been autografted in first complete remission (CR) and 48 in second remission. Several conditioning regimens have been utilized, mainly consisting of BAVC (an original polichemotherapy schedule, BCNU, mAMSA, VP-16 and Ara-C) (63 cases) and of total body irradiation (TBI) plus Melphalan (33 cases): other 28 patients received different TBI-including regimens, and 34 received various chemotherapy regimens (Busulfan plus cyclophosphamide +/- VP-16, Busulfan plus Melphalan, Melphalan alone). Projected event-free survival (EFS) for patients autografted in first CR is 41.4% (S.E. 5.5%) at 7 years, with a total of 53 patients in continuous CR. EFS is better in patients receiving a TBI-including regimen: 78.8% versus 27.2% (p = 0.0001). In particular, results obtained in a subgroup of 21 cases receiving TBI + melphalan and purged marrow are particularly encouraging, with a EFS > 85% projected a 7 years. The overall EFS in second CR is 41.5% at 7 years, and no difference have been observed after a TBI-including regimen or after a chemotherapy regimen, being EFS 43.1% and 39.3% for these 2 groups respectively. A total of 11 transplant-related deaths occurred, with 5 patients (4.5%) dead in first CR and 6 (12%) dead in second CR within 100 days from transplant. From these data, ABMT is confirmed to represent an effective treatment for AML after first relapse, while the encouraging results obtained in first CR with TBI-including regimens should be confirmed with a longer follow up and a larger number of patients.

Interleukin-2 before and/or after autologous bone marrow transplantation for pediatric acute leukemia patients.

The role of ABMT in the treatment of acute leukemia patients with poor prognosis is controversial because of the high risk of relapse. We attempted to obtain an anti-tumor effect by administering rIL-2 pre- and/or post-ABMT. We report our experience in 10 consecutive pediatric patients: two AML late responders and eight ALL in 2nd or subsequent CR who received ABMT and rIL-2. Five patients (group A) received rIL-2 only post-ABMT. A 120 h/week rIL-2 'induction' cycle at 6 x 10(6) IU/m2/24 h was administered by continuous intravenous infusion for 2 weeks. A further six maintenance rIL-2 cycles at 18 x 10(6) IU/m2/24 h were given 72 h/week on a monthly basis. Five patients (group B) received a single 120 h cycle of rIL-2 at 6 x 10(6)/m2/24 h before BM harvesting. Three of the five group B patients entered the same protocol described above after ABMT. Increased NK and LAK activity were documented. The cycles were well tolerated; no delayed engraftment in group B was observed. One patient in group A and two patients in group B are still in CCR, respectively 47, 42 and 15 months after ABMT. Our rIL-2 regimen; pre- and/or post-ABMT, was safely tolerated and induced significant immunomodulatory effects in pediatric patients

Extracorporeal photochemotherapy for the treatment of graft-versus-host disease.

Photopheresis is an extracorporeal photochemotherapy (ECP) used for the treatment of oncological and autoimmune diseases. Lymphocytes are drawn from the patients by leukapheresis, treated with 8-methoxypsoralen (8-MOP) and ultraviolet light A (UVA) in an extracorporeal system; then, reinfused to the host. Because skin exposure to 8-MOP and UVA (PUVA) has been shown to improve cutaneous GVHD, we evaluated in a pilot study, if ECP might be beneficial for patients with GVHD unresponsive to conventional protocols. In this study, we enrolled 9 children or young adults, with acute (no = 1) or chronic extensive GVHD (no. = 8). A significant improvement was observed in three of the 5 patients with scleroderma-like lesions and in one patient with severe liver involvement. Karnofsky performance score improved from 30-50% to 90% in the 4 responders. The better control of GVHD in these patients allowed a reduction of the immunosuppressive therapy that was, finally, discontinued in two. No significant side effects were observed during ECP. Our results suggest that ECP is a nonaggressive treatment that may benefit patients with c-GVHD unresponsive to standard immunosuppressive therapies.

ABMT for early isolated extramedullary relapse of childhood ALL.

From July 1987 to July 1991, 12 children underwent AMBT following high-dose cytarabine (HD Ara-C) plus 14.4 Gy hyperfractionated total body irradiation (hyfr-TBI) for early isolated extramedullary relapse of ALL, while in first BM remission. No patient received intrathecal prophylaxis following AMBT. One patient died on day +5 due to sepsis and three patients, two of them transplanted in second and third CNS relapse, respectively, died from BM relapse occurring 1.5, 4 and 5 months after AMBT. Eight of the 12 survive disease-free with a median follow-up of 24 months (range 14-62 months). The toxicity of HD Ara-C plus hyfr-TBI was acceptable and well controlled with supportive therapy. These results suggest that ABMT following HD Ara-C plus hyfr-TBI may eradicate leukemia from extramedullary sites of ALL relapse.

Fatal pneumopathy in children after bone marrow transplantation--report from the Italian Registry. Italian Association of Pediatric Hematology-Oncology BMT Group.

We have examined data reported in the AIEOP-BMT Registry in order to determine the incidence, causes and risk factors for fatal pneumopathy after bone marrow transplantation in a pediatric population. Overall, in the Registry 1134 children are reported, 531 of whom received an autologous BMT, 468 allomatched BMT, eight syngeneic, 75 mismatched, 29 unrelated and 23 peripheral blood progenitor cells as rescue after myeloablative therapy in the period 1983-1993. 198 patients out of 1134 (17%) died of transplant-related causes and 86 of them died of pulmonary complications: 12 were recorded as fungal pneumonia, eight bacterial, four bacterial and fungal, six viral, two Pneumocystis carinii pneumonia, 12 ARDS, 13 interstitial, 29 unspecified 'respiratory failure'. Multivariate analysis showed that only type of graft and presence or absence of Pneumocystis carinii prophylaxis influence the cumulative incidence of fatal pneumonia. After autologous BMTs only Pneumocystis carinii prophylaxis was significant in multivariate analysis. After allogeneic BMTs multivariate analysis showed that BMT type, Pneumocystis carinii prophylaxis and GVHD grade seem to maintain their influence on cumulative incidence of fatal pneumonia. After BMT the incidence of fatal pneumopathy in children is low (9%), but it represents the second cause of death after primary disease. Pneumocysti carinii prophylaxis should also be given after autologous BMT.

Allogeneic bone marrow transplantation in children with acute myelogenous leukemia in first remission. Associazione Italiana di Ematologia e Oncologia Pediatrica (AIEOP) and the Gruppo Italiano per il Trapianto di Midollo Osseo (GITMO).

Fifty-nine children, aged 1-15 years, with acute myelogenous leukemia (AML) received a bone marrow transplant (BMT) from an HLA-identical sibling (n = 57) or from an identical twin (n = 2), while in first remission (CR). These children represent, to the best of our knowledge, all children grafted in first CR in 11 Italian centers between 1980 and 1990. Patients were prepared with total body irradiation (TBI) plus cyclophosphamide (CY) (n = 50) or melphalan (n = 2) or with busulfan plus CY (n = 7). GVHD prophylaxis consisted of cyclosporin A (n = 48), methotrexate (n = 7) or cyclosporin and methotrexate (n = 2). Survivors have been followed for 21-137 months (median 59 months). Actuarial relapse-free survival was 58% at 66-137 months (95% confidence interval (CI) 44-72). Actuarial risk of relapse was 23% at 48 months (95% CI 10.9-34.8). Risk of non-relapse deaths was 33% in the period 1980-87 and 4% in the period 1988-90 (p = 0.02). In multivariate analysis patients with a blood cell count > 14 x 10(9)/l at diagnosis showed a lower relapse-free survival compared with patients with counts < 14 x 10(9)/l (p = 0.006). We could not detect an effect of FAB subtype, patient age, time to achieve remission or transplant-related variables, including year of BMT, on relapse-free survival. In conclusion, allogeneic marrow transplantation can achieve long-term relapse-free survival in over 50% of children with AML and should be considered as consolidation therapy if a matched sibling is available.(ABSTRACT TRUNCATED AT 250 WORDS)

Autologous bone marrow transplantation for childhood acute lymphoblastic leukemia in remission: first choice for isolated extramedullary relapse?

Between May 1984 and May 1992, 75 children 3-19 (median 9) years of age underwent autologous marrow transplant. Clinical data were obtained from the BMT Registry of the AIEOP (Italian Association of Pediatric Hemato/Oncology). Fifty-six children were transplanted after marrow +/- other site(s) relapse and 19 after an isolated extramedullary relapse. The transplant preparative regimens varied according to the center performing the transplant. Seven patients (9%) died of transplant-related complications. Forty-four (58.6%) of 75 patients relapsed again following autologous BMT. The 5-year DFS was 27.8%. An isolated extramedullary relapse was the only variable that statistically influenced DFS. In this retrospective study, autologous BMT for patients with ALL in second CR following marrow relapse did not offer an encouraging result (13% probability of DFS at 5 years), whereas autologous BMT following an (early) isolated extramedullary relapse resulted in nearly 70% DFS. Autologous BMT may be appropriate for this latter group of patients.

Severe thrombotic microangiopathy: an infrequent complication of bone marrow transplantation. Gruppo Italiano Trapianto Midollo Osseo (GITMO).

Thrombotic microangiopathy (TMA) usually occurs during the first weeks following transplantation in the setting of systemic infections or graft-versus-host reaction. However, some cases without any evidence of other complications or after autologous transplantation have been reported. Transplant-associated TMA (BMT-TMA) incidence ranges from 0% to 74%, possibly due to different diagnostic criteria. The GITMO Group provided the opportunity to retrospectively study 4334 consecutive Italian patients who received bone marrow transplants (1759 allogeneic and 2575 autologous BMT), during the 1985-1995 period. The present report focuses on patients with severe TMA requiring specific treatment. We identified nine cases of TMA as a complication of allogeneic BMT (0.51%), whereas three patients developed the syndrome after ABMT (0.13%); four of the 12 patients were not receiving CsA at the time of TMA onset. Finally, it is noteworthy that TMA occurred in seven patients as a late complication (up to 90 days after BMT). Despite intensive treatment, five of the seven patients with thrombotic thrombocytopenic purpura died. One death was observed among the five cases with hemolytic uremic syndrome.

Myeloablative therapy and bone marrow rescue in advanced neuroblastoma. Report from the Italian Bone Marrow Transplant Registry. Italian Association of Pediatric Hematology-Oncology, BMT Group.

This study reports a large cooperative experience in myeloablative therapy and bone marrow rescue undertaken to define better the outcome of children with disseminated neuroblastoma after megatherapy. Between 1984 and 1993, 135 children underwent myeloablative therapy with bone marrow transplantation (BMT) in nine Italian Centres. One hundred and seventeen children received unpurged autologous BMT, five allogeneic BMT and 13 peripheral blood progenitor cells as rescue. Of these 135 children, 57 were in 1st CR, 11 in 2nd or subsequent CR, 42 in 1st PR, and 25 had more advanced disease. Twelve children (9%) died of toxicity, 86 relapsed or progressed at 1-68 months (median 7 months) and 80 of these subsequently died of progressive disease. Forty-three children are still alive with 37 in continuous remission at a median of 65 months (30-123 months) after BMT. Overall and disease-free survival at 8 years are 28.5% (s.e. 4.3) and 26% (s.e. 4), respectively. Disease-free survival is 34.6% (s.e. 6.7) for the patients grafted in 1st complete remission, 23.6% (s.e. 6.6) for patients grafted in 1st partial remission, 36.4% (s.e. 14.5) for patients grafted in 2nd or subsequent CR, and 8% (5.4) for patients with advanced disease. We conclude these data confirm that early toxicity of myeloablative therapy is manageable and that myeloablative therapy with bone marrow rescue may contribute to an improved long-term survival of children with disseminated neuroblastoma but the objective of cure of all patients remains distant.

Unrelated donor marrow transplantation: initial experience of the Italian bone marrow transplant group (GITMO).

From 1 September 1988 to 30 September 1993, a search for an unrelated donor (URD) was started for 633 Italian patients. Eighty-five of them (13%) were transplanted. Despite the introduction of more strict criteria for the selection of compatible donors, the percentage of patients who reached transplant increased significantly after December 1992. For patients who started a search before and after January 1993, respectively the probability of transplant by 8 and 16 months from search activation was 4 and 10%, compared to 22 and 37% (P = 0.0001). The average intervals between search activation and graft were 15 and 8 months respectively, for the first and second group (P = 0.0001). Data of 75 consecutive transplants performed up to March 1994 were analyzed. Actuarial 2-year survival was 15% for patients grafted before 1992 and 40% for those grafted after January 1992. In this latter period, survival of patients with malignant and non-malignant disorders was 32 and 67%, respectively. In univariate analysis, patients younger than 16 years (P = 0.01), patients grafted after 1992 (P = 0.01) and patients receiving the marrow from a 6-antigen matched donor (P = 0.01) showed a higher survival probability. Multivariate analysis did not show any difference, probably due to the low number of patients and to short follow-up. The adoption of stricter and more accurate HLA-matching criteria and the consequent reduction of deaths related to acute GVHD were the main reasons for the improvement of survival observed in patients grafted after 1992.

Autologous bone marrow transplantation for childhood acute lymphoblastic leukaemia in Italy. AIEOP/FONOP-TMO Group. Italian Association of Paediatric Haemato-Oncology.

From January 1984 to December 1994, ABMT was performed on 154 children (101 males, 53 females; median age 10, range 3-21 years) with ALL and registered for BMT by the AIEOP (Italian Association of Paediatric Haemato-Oncology). All patients were in CR: 98 were in 2nd CR and 56 were in >2nd CR. Fifteen children (9.7%) died of transplant-related mortality. Ninety-five patients (61.6%) relapsed at a median of 5 (range 1-42) months after ABMT. The 8-year EFS according to pre-BMT status was 34.6% (s.e. 4.9) for 2nd CR patients and 10.6% (s.e. 5.6) for patients in >2nd CR. By univariate analysis, site of relapse (isolated extramedullary (IE) vs BM: EFS = 68.5% vs 18.2%; P < 0.0001) and TBI containing regimen (TBI vs no TBI: EFS = 48.1 vs 15.4%; P = 0.0023) were significant factors for 2nd CR patients. When the 2nd CR subset with BM involvement was analysed, TBI became insignificant (EFS = 25.4 vs 11.8%). No factors influenced EFS in patients in >2nd CR. By multivariate analysis, site of relapse was the only significant factor in 2nd CR patients (P < 0.0001). In conclusion, ABMT is an effective treatment after one early IE relapse. Few patients can be rescued after BM relapse.

Autologous bone marrow transplantation for extramedullary relapse in childhood leukemia. The AIEOP Group and the FONOP. Italian Association of Pediatric Hemato/Oncology.

The role of autologous bone marrow transplantation (ABMT) in childhood ALL after an isolated extramedullary (IE) relapse is controversial. Between December 1984 and November 1995, 52 children underwent ABMT because of an IE relapse. The data were stored in the AIEOP-BMT Registry. Thirty four children were transplanted in 2nd CR; eighteen > 2nd CR. The median duration of 1st CR was 24 (range 3-69) and 18 (range 3-59) months, respectively. The median interval from last CR to ABMT was 6 (range 1-28) and 3 (range 1-81) months, respectively. The 5 year EFS for patients transplanted in 2nd CR was 67.7%, while the 3 year EFS for patients in > 2nd CR was 16.7%. In conclusion, ABMT was an effective treatment in early IE relapse only if performed in 2nd CR.

Autologous bone marrow transplantation for treatment of isolated central nervous system relapse of childhood acute lymphoblastic leukemia. AIEOP/FONOP-TMO group. Associzione Italiana Emato-Oncologia Pediatrica.

The purpose of this study was to assess the role of ABMT in children with ALL who are in 2nd CR after an early isolated CNS relapse. All children experiencing an isolated CNS relapse at 10 AIEOP centers (Associazione Italiana Emato-Oncologia Pediatrica) from 1986 to 1992 were eligible for this study. The series included 69 patients who relapsed within 3 years from diagnosis: 19 underwent ABMT, nine patients underwent ALLO-BMT from an HLA-identical sibling, and 41 received conventional chemotherapy (CHEMO). Statistical analysis was performed using a Cox's regression model, adjusting for the waiting time before transplantation and prognostic factors. The 5 years DFS was 56.3% (s.e. 12.3) for patients in the ABMT group. This compared favorably with the poor result (12.6% (s.e. 5.9)) seen in the CHEMO group. The risk of failures was reduced by one-third in the ABMT group as compared to the CHEMO group in the multivariate analysis (P < 0.01). In the ALLO group four out of nine patients were in CCR 4-5 years post-transplant. This study suggests that ABMT may also represent a valuable therapeutic choice for patients lacking a matched familiar donor in 2nd CR after an early isolated CNS relapse.

Bonding of cartilage matrices with cultured chondrocytes: an experimental model.

The capacity of isolated chondrocytes to join separate masses of cartilage matrix was investigated with composites implanted in subcutaneous pouches in nude mice. Slices of articular cartilage were harvested from lambs and were devitalized by cyclic freezing and thawing. The slices were then either co-cultured with viable allogeneic lamb chondrocytes (experimental) or cultured without such chondrocytes (control). Composites of three slices were constructed with use of fibrin glue and were implanted in nude mice for periods ranging from 7 to 42 days. Bonding of the experimental matrices with viable chondrocytes was achieved at 28 and 42 days, as assessed by direct examination, histology, thymidine uptake, and fluorescence. No bonding occurred in the control composites without viable chondrocytes. We conclude that devitalized cartilage matrix is a scaffold to which isolated chondrocytes can attach and begin to repopulate.