Quantitative analysis of contribution of mild and moderate hyperthermia to thermal ablation and sensitization of irreversible electroporation of pancreatic cancer cells.

INTRODUCTION: Irreversible electroporation (IRE) is an ablation modality that applies short, high-voltage electric pulses to unresectable cancers. Although considered a non-thermal technique, temperatures do increase during IRE. This temperature rise sensitizes tumor cells for electroporation as well as inducing partial direct thermal ablation. AIM: To evaluate the extent to which mild and moderate hyperthermia enhance electroporation effects, and to establish and validate in a pilot study cell viability models (CVM) as function of both electroporation parameters and temperature in a relevant pancreatic cancer cell line. METHODS: Several IRE-protocols were applied at different well-controlled temperature levels (37 °C ≤ T ≤ 46 °C) to evaluate temperature dependent cell viability at enhanced temperatures in comparison to cell viability at T = 37 °C. A realistic sigmoid CVM function was used based on thermal damage probability with Arrhenius Equation and cumulative equivalent minutes at 43 °C (CEM43°C) as arguments, and fitted to the experimental data using "Non-linear-least-squares"-analysis. RESULTS: Mild (40 °C) and moderate (46 °C) hyperthermic temperatures boosted cell ablation with up to 30% and 95%, respectively, mainly around the IRE threshold Eth,50% electric-field strength that results in 50% cell viability. The CVM was successfully fitted to the experimental data. CONCLUSION: Both mild- and moderate hyperthermia significantly boost the electroporation effect at electric-field strengths neighboring Eth,50%. Inclusion of temperature in the newly developed CVM correctly predicted both temperature-dependent cell viability and thermal ablation for pancreatic cancer cells exposed to a relevant range of electric-field strengths/pulse parameters and mild moderate hyperthermic temperatures.

Treat to target (drug-free) inactive disease in DMARD-naive juvenile idiopathic arthritis: 24-month clinical outcomes of a three-armed randomised trial.

QUESTION: Which is the best strategy to achieve (drug-free) inactive disease in juvenile idiopathic arthritis (JIA)? METHODS: In a randomised, single-blinded, study in disease-modifying anti-rheumatic drug (DMARD)-naive patients with JIA, three treatment-strategies were compared: (1) sequential DMARD-monotherapy (sulfasalazine or methotrexate (MTX)), (2) combination therapy MTX + 6 weeks prednisolone and (3) combination therapy MTX +etanercept. Treatment-to-target entailed 3-monthly DMARD/biological adjustments in case of persistent disease activity, with drug tapering to nil in case of inactive disease.After 24 months, primary outcomes were time-to-inactive-disease and time-to-flare after DMARD discontinuation. Secondary outcomes were adapted ACRPedi30/50/70/90 scores, functional ability and adverse events. RESULTS: 94 children (67 % girls) aged median (IQR) 9.1 (4.6-12.9) years were enrolled: 32 in arms 1 and 2, 30 in arm 3. At baseline visual analogue scale (VAS) physician was mean 49 (SD 16) mm, VAS patient 53 (22) mm, erythrocyte sedimentation rate 12.8 (14.7), active joints median 8 (5-12), limited joints 2.5 (1-4.8) and Childhood Health Assessment Questionnaire score mean 1.0 (0.6).After 24 months, 71% (arm 1), 70% (arm 2) and 72% (arm 3) of patients had inactive disease and 45% (arm 1), 31% (arm 2) and 41% (arm 3) had drug-free inactive disease. Time-to-inactive-disease was median 9.0 (5.3-15.0) months in arm 1, 9.0 (6.0-12.8) months in arm 2 and 9.0 (6.0-12.0) months in arm 3 (p=0.30). Time-to-flare was not significantly different (overall 3.0 (3.0-6.8) months, p=0.7). Adapted ACR pedi-scores were comparably high between arms. Adverse events were similar. CONCLUSION: Regardless of initial specific treatments, after 24 months of treatment-to-target aimed at drug-free inactive disease, 71% of recent-onset patients with JIA had inactive disease (median onset 9 months) and 39% were drug free. Tightly controlled treatment-to-target is feasible. TRIAL REGISTRATION NUMBER: 1574.

Measurement and analysis of the impact of time-interval, temperature and radiation dose on tumour cell survival and its application in thermoradiotherapy plan evaluation.

PURPOSE: Biological modelling of thermoradiotherapy may further improve patient selection and treatment plan optimisation, but requires a model that describes the biological effect as a function of variables that affect treatment outcome (e.g. temperature, radiation dose). This study aimed to establish such a model and its parameters. Additionally, a clinical example was presented to illustrate the application. METHODS: Cell survival assays were performed at various combinations of radiation dose (0-8 Gy), temperature (37-42 °C), time interval (0-4 h) and treatment sequence (radiotherapy before/after hyperthermia) for two cervical cancer cell lines (SiHa and HeLa). An extended linear-quadratic model was fitted to the data using maximum likelihood estimation. As an example application, a thermoradiotherapy plan (23 × 2 Gy + weekly hyperthermia) was compared with a radiotherapy-only plan (23 × 2 Gy) for a cervical cancer patient. The equivalent uniform radiation dose (EUD) in the tumour, including confidence intervals, was estimated using the SiHa parameters. Additionally, the difference in tumour control probability (TCP) was estimated. RESULTS: Our model described the dependency of cell survival on dose, temperature and time interval well for both SiHa and HeLa data (R2=0.90 and R2=0.91, respectively), making it suitable for biological modelling. In the patient example, the thermoradiotherapy plan showed an increase in EUD of 9.8 Gy that was robust (95% CI: 7.7-14.3 Gy) against propagation of the uncertainty in radiobiological parameters. This corresponded to a 20% (95% CI: 15-29%) increase in TCP. CONCLUSIONS: This study presents a model that describes the cell survival as a function of radiation dose, temperature and time interval, which is essential for biological modelling of thermoradiotherapy treatments.

CD226 (DNAM-1) is associated with susceptibility to juvenile idiopathic arthritis.

OBJECTIVES: Juvenile idiopathic arthritis (JIA) is considered a complex genetic autoimmune disease. We investigated the association of genetic variants previously implicated in JIA, autoimmunity and/or immunoregulation, with susceptibility to JIA. METHODS: A genetic association study was performed in 639 JIA patients and 1613 healthy controls of northwest European descent. Ninety-three single nucleotide polymorphisms (SNP) were genotyped in a candidate gene approach. Results of the entire JIA patient group (all subtypes) were compared with results obtained, alternatively, with a clinically homogeneous patient group including only oligoarticular and rheumatoid factor (RF) negative polyarticular JIA patients (n=493). Meta-analyses were performed for all SNPs that have been typed in other Caucasian JIA cohorts before. RESULTS: SNPs in or near PTPN22, VTCN1, the IL2-IL21 region, ANKRD55 and TNFA were confirmed to be associated with JIA (p<0.05), strengthening the evidence for involvement of these genes in JIA. In the majority of these replicated SNPs, effect sizes were larger when analysing a homogeneous patient cohort than when analysing all subtypes. We identified two novel associations with oligoarticular and RF-negative polyarticular JIA: CD226 rs763361 (OR 1.30, 95% CI 1.12 to 1.51, p=0.0006) and CD28 rs1980422 (OR 1.29, 95% CI 1.07 to 1.55, p=0.008). Meta-analyses including reported studies confirmed the association of both SNPs with susceptibility to JIA (OR 1.16, p=0.001 and OR 1.18, p=0.001, for rs763361 and rs1980422, respectively). CONCLUSIONS: The CD226 gene has been identified as novel association with JIA, and a SNP near CD28 as a suggestive association. Both genes are probable candidate risk factors, since they are involved in costimulation of T cells.

Chromatin mobility is increased at sites of DNA double-strand breaks.

DNA double-strand breaks (DSBs) can efficiently kill cancer cells, but they can also produce unwanted chromosome rearrangements when DNA ends from different DSBs are erroneously joined. Movement of DSB-containing chromatin domains might facilitate these DSB interactions and promote the formation of chromosome rearrangements. Therefore, we analyzed the mobility of chromatin domains containing DSBs, marked by the fluorescently tagged DSB marker 53BP1, in living mammalian cells and compared it with the mobility of undamaged chromatin on a time-scale relevant for DSB repair. We found that chromatin domains containing DSBs are substantially more mobile than intact chromatin, and are capable of roaming a more than twofold larger area of the cell nucleus. Moreover, this increased DSB mobility, but not the mobility of undamaged chromatin, can be reduced by agents that affect higher-order chromatin organization.

Genetic variation in VTCN1 (B7-H4) is associated with course of disease in juvenile idiopathic arthritis.

OBJECTIVE: The course of disease in juvenile idiopathic arthritis (JIA) is unpredictable with episodes of activity and remission. In order to identify predictive factors, 93 SNPs, JIA subtype, age at onset and ANA status were studied in relation to disease course. METHODS: Genetic and clinical parameters were analysed in a cohort of 272 Caucasian patients with persistent oligoarthritis (n=129), extended oligoarthritis (n=57) and rheumatoid factor negative polyarthritis (n=86). Categories of disease course (remitting (n=65), intermediate (n=96) and unremitting (n=111)) were designed based on the cumulative time spent in active disease in the first 2 years. RESULTS: Univariate analysis revealed association of the course of disease with JIA subtype (p=5.7*10(-5)) and three SNPs; VTCN1 rs10 923 223 (p=4.4*10(-5)), VTCN1 rs12 046 117 (p=0.017) and CDK6 rs42 041 (p=0.038). In a subsequent multivariate ordinal logistic regression analysis, VTCN1 rs10 923 223 (OR 0.41, 95%-CI 0.26 to 0.63) and JIA subtype (OR 3.8, 95%-CI 2.0 to 7.2; OR 2.5, 95%-CI 1.4 to 4.2, for extended oligoarthritis and RF-negative polyarthritis vs persistent oligoarthritis, respectively) were the strongest independent factors for course of disease. CONCLUSIONS: This study provides evidence that VTCN1, encoding B7-H4, is associated with course of disease in selected subtypes of JIA. VTCN1 might be useful in predicting the course of disease.

Disease activity patterns in juvenile systemic lupus erythematosus and its relation to early aggressive treatment.

This study aimed to determine disease activity patterns in juvenile systemic lupus erythematosus (jSLE) and its relation to early treatment. All jSLE patients who visited the outpatient departments of three Dutch university hospitals for at least 6 months were included. Data were retrospectively collected from each patient visit and hospitalization. Patient characteristics, clinical and laboratory findings categorized in organ systems, flare rate, medication use and disease course were analysed. Included were 35 patients (female 77%; White 47%) with a total follow-up of 142 years. Median age at diagnosis was 12.8 years. Flare rate was 0.45/ patient-year. An organ system not earlier involved was affected in 34% of flares. Identifiable disease activity patterns were: chronic active (49%), relapse remitting (14%) and long quiescence (37%), with no significant difference in organ involvement at diagnosis. Positive anti-Sm and non-White ethnicity were significantly associated with a chronic active pattern. In 14 patients with severe symptoms at diagnosis, treatment with intravenous cyclophosphamide and/or biologics and/or intravenous methylprednisone in the first 6 months resulted in a long quiescence pattern in seven patients. In conclusion, distinct disease activity patterns are identifiable in children. Suppression of disease with early aggressive treatment may decrease the rate of progression.

Long-term follow-up on effectiveness and safety of etanercept in juvenile idiopathic arthritis: the Dutch national register.

OBJECTIVE: We undertook an observational study to obtain a complete overview of the long-term effectiveness and safety of etanercept in patients with different juvenile idiopathic arthritis (JIA) subtypes. METHODS: At baseline we collected patient and disease characteristics of all Dutch patients with JIA who started treatment with etanercept. Disease activity was evaluated (at start of the study, after 3 months and then yearly) according to the JIA core set of the American College of Rheumatology paediatric definition for 30, 50 and 70% improvement (ACR Pedi 30, 50 and 70). Use of etanercept and concomitant drugs was monitored. Adverse events were recorded. RESULTS: We included 146 patients with JIA with a median follow-up of 2.5 years per patient (range 0.3-7.3). JIA subtypes represented: 27% systemic, 8% polyarticular rheumatoid factor positive, 38% polyarticular rheumatoid factor negative, 19% oligoarticular extended, 3% enthesitis-related and 5% psoriatica. Most patients (77%) met the criteria of the ACR Pedi 30 in the first 3 months of treatment. For the majority of patients this improvement was sustained; 53 (36%) of all patients met the remission criteria. No other second-line agents were needed in 43 patients. Although patients with systemic JIA responded initially less to etanercept therapy than patients from other subtypes, those who did respond showed equal effectiveness in the long term. Serious adverse events rate was low (0.029 per patient year). CONCLUSIONS: Etanercept is effective and safe in JIA, even for a large proportion of the patients with systemic JIA. The greatest improvement occurred in the first 3 months of treatment, and was sustained for a long time in most patients (up to 75 months).

Transient inhibition of Calyculin A induced premature chromosome condensation by hyperthermia.

The analysis of chromosomal aberrations by premature chromosome condensation (PCC) induced by Calyculin A (Cal) is feasible in tumor biopsies from patients and has the potential to predict sensitivity to radiotherapy. As hyperthermia (HT) improves radiotherapy outcome in certain tumor sites, it was investigated whether PCC induction is still possible after temperatures reached in the clinic. Human cervical carcinoma (CaSki) and lung carcinoma (SW-1573) cells were incubated with Cal to induce PCC immediately after 1 h treatment at temperatures ranging from 41 degrees C to 43 degrees C and after recovery for up to 24 h after treatment with 43 degrees C. Levels of phosphorylated Cdc2 (at the Tyr15 residue), histone H3 (at the Ser10 residue) and Cyclin B1 were investigated by immunoblotting. The amount of cells positive for phosphorylated histone H3 was determined by flow cytometry. Temperatures > or =42.5 degrees C inhibited the induction of PCC by Cal, while recovery of PCC-induction was observed at >20 h after treatment in both cell lines. The phosphorylation status of Cdc2 as well as of histone H3 in cells treated with Cal directly after HT at 43 degrees C was similar to that of cells treated with Cal alone or treated with Cal 24 h after HT at 43 degrees C. HT alone did not affect the levels of phosphorylated Cdc2, while phosphorylation levels of histone H3 were increased as compared with control status of these two proteins. Phosphorylated and total Cyclin B1 levels were not influenced by any of the treatments. Flow cytometric analysis confirmed that HT at 43 degrees C did not interfere with phosphorylation of histone H3. Our data indicate that HT transiently inhibits PCC induction by Cal in a temperature-dependent manner. Therefore, an interval of at least 24 h after HT should be applied before taking tumor biopsies for karyogram analysis of patients treated with temperatures above 42.5 degrees C.

No radiographic wrist damage after treatment to target in recent-onset juvenile idiopathic arthritis.

BACKGROUND: To evaluate radiographic progression of patients with new-onset juvenile idiopathic arthritis (JIA) in response to an early, tightly-controlled, treatment-to-target. METHODS: Patients with JIA participating in the BeSt-for-Kids-study, randomized to 3 treatment strategy arms, were eligible if at least 1 conventional wrist-radiograph was available. Bone damage as reflected by carpal length was assessed using the Poznanski-score. The BoneXpert-method was used to determine the Bone Age (BA, > 5 years) and bone mineral density (BMD) of the wrist. These scores were evaluated over time and compared between the treatment arms and mean JADAS10-score using linear mixed models corrected for age and symptom duration. RESULTS: In 60 patients, 252 radiographs were analysed. Baseline age and symptom duration were different between the arms. No difference in comparison to the healthy reference population was found at baseline for the Poznanski-score (IQR varying from - 0,82; 0.68), nor for BA (varying from - 0.88 to 0.74). Baseline BMD was statistically significantly lower in arm 3 (initial treatment with etanercept and methotrexate) (- 1.48; - 0.68) compared to arm 1 (- 0.84; - 0.04) and arm 2 (- 0.93; 0.15). After treatment to target inactive disease, the Poznanski-scores and the BA remained clinically unchanged, while the BMD in arm 3 improved (p < 0.05 vs arm 1). CONCLUSIONS: Recent-onset JIA patients, treated-to-target aimed at inactive disease, showed no signs of radiographic wrist damage (Poznanski-score, BA or BMD) either at baseline or at follow-up, irrespective of treatment arm. A lower BMD at baseline in arm 3, initially treated with methotrexate and etanercept, improved significantly after treatment. TRIAL REGISTRATION: NTR, NL1504 (NTR1574). Registered 01-06-2009.

The TRAF1/C5 region is a risk factor for polyarthritis in juvenile idiopathic arthritis.

OBJECTIVE: Juvenile idiopathic arthritis (JIA) is a chronic disorder in which both genetic and environmental factors are involved. Recently, we identified the TRAF1/C5 region (located on chromosome 9q33-34) as a risk factor for rheumatoid arthritis (RA) (p(combined) = 1.4 x 10(-8)). In the present study the association of the TRAF1/C5 region with the susceptibility to JIA was investigated. METHODS: A case-control association study was performed in 338 Caucasian patients with JIA and 511 healthy individuals. We genotyped the single nucleotide polymorphism rs10818488 as a marker for the TRAF1/C5 region. RESULTS: The A allele was associated with the susceptibility to rheumatoid factor-negative polyarthritis with an 11% increase in allele frequency (OR 1.54, 95% CI 1.09 to 2.18; p = 0.012). This association was stronger when combining subtypes with a polyarticular phenotype (OR 1.46, 95% CI 1.12 to 1.90; p = 0.004). In addition, we observed a trend towards an increase in A allele frequency in patients with extended oligoarthritis versus persistent oligoarthritis (49%, 38% respectively); p = 0.055. CONCLUSIONS: Apart from being a well replicated risk factor for RA, TRAF1/C5 also appears to be a risk factor for the rheumatoid factor-negative polyarthritis subtype of JIA and, more generally, seems to be associated with subtypes of JIA characterised by a polyarticular course.

Development of a web-based register for the Dutch national study on biologicals in JIA: www.ABC-register.nl.

OBJECTIVES: Most clinical studies use paper case record forms (CRFs) to collect data. In the Dutch multi-centre observational study on biologicals we encountered several disadvantages of using the paper CRFs. These are delay in data collection, lack of overview in collected data and difficulties in obtaining up-to-date interim reports. Therefore, we wanted to create a more effective method of data collection compared with CRFs on paper in a multi-centre study. METHODS: We designed a web-based register with the intention to make it easy to use for participating physicians and at the same time accurate and up-to-date. Security demands were taken into account to secure the safety of the patient data. RESULTS: The web-based register was tested with data from 161 juvenile idiopathic arthritis patients from nine different centres. Internal validity was obtained and user-friendliness guaranteed. To secure the completeness of the data automatically generated e-mail alerts were implemented into the web-based register. More transparency of data was achieved by including the option to automatically generate interim reports of data in the web-based register. The safety was tested and approved. CONCLUSIONS: By digitalizing the CRF we achieved our aim to provide easy, rapid and safe access to the database and contributed to a new way of data collection. Although the web-based register was designed for the current multi-centre observational study, this type of instrument can also be applied to other types of studies. We expect that especially collaborative study groups will find it an efficient tool to collect data.

A comparison of three treatment strategies in recent onset non-systemic Juvenile Idiopathic Arthritis: initial 3-months results of the BeSt for Kids-study.

BACKGROUND: Combination therapy with prednisone or etanercept may induce earlier and/or more improvement in disease activity in Disease Modifying Anti Rheumatic Drug (DMARD) naïve non-systemic Juvenile Idiopathic Arthritis (JIA) patients. Here we present three months clinical outcome of initial treatments of the BeSt-for-Kids study. METHODS: Included patients were randomized to either: 1. initial DMARD-monotherapy (sulfasalazine (SSZ) or methotrexate (MTX)), 2. Initial MTX / prednisolone-bridging, 3. Initial combination MTX/etanercept. Percentage inactive disease, adjusted (a) ACR Pedi30, 50 and 70 and JADAS after 6 and 12 weeks of treatment (intention to treat analysis) and side effects are reported. RESULTS: 94 patients (67% girls, 32 (arm 1), 32 (arm 2) and 30 (arm 3) with median (InterQuartileRange) age of 9.1 (4.7-12.9) years were included. 38% were ANA positive, 10 had oligo-articular disease, 68 polyarticular JIA and 16 psoriatic arthritis. Baseline median (IQR) ACRpedi-scores: VAS physician 49 (40-58) mm, VAS patient 54 (37-70) mm, ESR 6.5 (2-14.8)mm/hr, active joint count 8 (5-12), limited joint count 3 (1-5), CHAQ score 0.88 (0.63-1.5). In arm 1, 17 started with MTX, 15 with SSZ. After 3 months, aACR Pedi 50 was reached by 10/32 (31%), 12/32(38%) and 16/30 (53%) (p = 0.19) and aACR Pedi 70 was reached by 8/32 (25%), 6/32(19%) and 14/30(47%) in arms 1-3 (p = 0.04). Toxicity was similar. Few serious adverse events were reported. CONCLUSION: After 3 months of treatment in a randomized trial, patients with recent-onset JIA achieved significantly more clinical improvement (aACRPedi70) on initial combination therapy with MTX / etanercept than on initial MTX or SSZ monotherapy. TRIAL REGISTRATION: NTR1574 . Registered 3 December 2008.

Effects of cisplatin and gamma-irradiation on cell survival, the induction of chromosomal aberrations and apoptosis in SW-1573 cells.

PURPOSE: Cisplatin was found to radiosensitize SW-1573 cells by inhibition of PLDR. Therefore, it was investigated whether cisplatin combined with gamma-radiation leads to an increase in the number of chromosomal aberrations or apoptotic cells compared with radiation alone. METHODS: Confluent cultures of the human lung carcinoma cell line SW-1573 were treated with 1 microM cisplatin for 1 h, 4 Gy gamma-radiation, or a combination of both. Cell survival was studied by the clonogenic assay. Aberrations were analysed by FISH in prematurely condensed chromosomes (PCC) and the induction of apoptosis by counting fragmented nuclei. RESULTS: A radiosensitizing effect of cisplatin on cell survival was observed if time for PLDR was allowed. An increased number of chromosomal fragments were observed immediately after irradiation compared with 24 h after irradiation whereas color junctions are only formed 24 h after irradiation. No increase in chromosomal aberrations was found after combined treatment, but a significantly enhanced number of fragmented nuclei were observed when confluent cultures were replated after allowing PLDR. CONCLUSION: The inhibition of PLDR by cisplatin in delayed plated SW-1573 cells did not increase chromosomal aberrations, but increased the induction of apoptosis.

[The possible role of microchimerism in the aetiology of autoimmune diseases]. / Mogelijke rol van microchimerisme bij het ontstaan van auto-immuunziekten.

The aetiology of several autoimmune diseases has not yet been elucidated. Microchimerism, the persistence of small numbers ofallogeneic cells in an individual, has been mentioned recently in connection with the occurrence of autoimmune diseases such as systemic sclerosis and juvenile inflammatory idiopathic myopathy. These allogeneic cells can originate from mutual foeto-maternal exchange of blood cells during pregnancy or from a donor after blood transfusion or (organ) transplantation. In some cases, a syndrome then develops that resembles the chronic graft-versus-host reaction after stem-cell transplantation, in which allogeneic cells react with autologous cells. Studies on microchimerism in patients with systemic sclerosis and juvenile inflammatory idiopathic myopathy, compared to controls, sometimes reveal a clearly increased prevalence of microchimerism in patients. However, microchimerism can also be found in healthy individuals. Direct proof of a causal relation between microchimerism and autoimmune diseases does not exist. Additional genetic or environmental factors may be partly responsible for a disturbed balance between tolerance and aggression.

Antibodies to a 15 kD nuclear antigen in patients with juvenile chronic arthritis and uveitis.

Young girls with a pauciarticular onset of juvenile chronic arthritis and circulating antinuclear antibodies are at risk for chronic uveitis. The actual nuclear antigen for these antinuclear antibodies has not been defined. Conventional laboratory techniques, such as counter immunoelectrophoresis, have shown that antibodies to well defined "extractable nuclear antigens" (eg, RNP, Sm, SS-A, and SS-B) are not present in patients with juvenile chronic arthritis. Therefore, other, previously unknown nuclear antigens may be involved. Sera of 64 patients with juvenile chronic arthritis, including 22 patients with chronic anterior uveitis, were studied using the immunoblotting technique to characterize the nuclear antigens. Antinuclear antibodies were present in 12 (55%) of the 22 patients with uveitis, and only in six (14%) of the 42 patients without chronic anterior uveitis. With the immunoblotting technique, antibodies to a 15 kD nuclear antigen were found in 10 (45%) of the 22 patients with chronic anterior uveitis, whereas only two (5%) of the 42 patients without chronic anterior uveitis showed these antibodies (P less than 0.001). Only clearly visible and reproducible lines in the immunoblotting patterns were studied. This may provide a diagnostic tool for the early detection of uveitis and means for further pathogenetic studies.

Long-term follow-up of autologous stem cell transplantation for refractory juvenile idiopathic arthritis.

Since 1997, autologous stem cell transplantation (ASCT) had been applied to more than 40 children with polyarticular or systemic juvenile idiopathic arthritis (JIA). For this review, results of the follow-up are available from 25 children with systemic JIA and six with polyarticular JIA that were reported in detail from eight different pediatric European transplant centers. Before ASCT all children had progressive disease despite the use of corticosteroids, methotrexate (MTX) up to 1 mg/kg/week, cyclosporin (2.5 mg/kg/day) and/or anti-TNFalpha therapy. The clinical follow-up of these children ranges from 8 to 60 months (median 33 months).

Importance of TP53 and RB in the repair of potentially lethal damage and induction of color junctions after exposure to ionizing radiation.

Repair of potentially lethal damage (PLD) was investigated in cells with functional G1-phase arrest with wild-type TP53 and wild-type RB and in cells in which G1-phase arrest was abrogated by inactivation of TP53 or RB. Confluent cultures of cells were plated for clonogenic survival assay either immediately or 24 h after irradiation. Induction of color junctions, an exchange between a painted and unpainted chromosome, was studied in chromosomes 18 and 19 after irradiation with 4 Gy gamma rays. Significant repair of PLD was found in cells carrying both wild-type TP53 and wild-type RB. In cells in which TP53 or RB was inactivated, the survival curves from immediately plated and delayed-plated cells were not significantly different. The numbers of radiation-induced color junctions in chromosomes 18 and 19 were similar in all cell lines. From this study we conclude that a functional G1-phase arrest is important for repair of PLD and that TP53 and RB do not affect the frequencies of induction of color junctions in chromosome 18 or 19.