Replicative aging of human articular chondrocytes during ex vivo expansion

OBJECTIVE: To investigate the contribution of clinical ex vivo expansion protocols to replicative aging of human chondrocytes. METHODS: Primary human chondrocytes were cultured as monolayers after isolation from 7 articular cartilage specimens. Cells were passaged corresponding to 12-19 cell population doublings (cpd). Aliquots of the cells were collected from each passage and analyzed for telomere length and telomerase activity. RESULTS: The rate of telomere shortening was heterogeneous, ranging from 147 to 431 bp/cpd (mean +/- SD 305 +/- 122). Telomerase activity was detected at various time points during passaging in 5 of 7 primary chondrocytes analyzed, but not in native human articular cartilage specimens. According to our data, an 8-10-fold ( approximately 3 cpd) ex vivo expansion of articular chondrocytes, as typically performed for transplantation procedures, leads to telomere erosion in the range of 900 bp. This is comparable with 30 years of aging based on the in vivo rate of telomere shortening of 30 bp/year recently found in chondrocytes. CONCLUSION: If telomere shortening is an important determinant of aging in human articular cartilage, an additional telomere loss due to ex vivo expansion might affect the incidence or time of onset of age-related cartilage disorders. However, given the limited extent of expansion performed in the clinical setting to date, a significant telomere-mediated increase in the risk of malignant transformation or replicative exhaustion of the transplanted cells seems unlikely.     

Effect on blood pressure of lumiracoxib versus ibuprofen in patients with osteoarthritis and controlled hypertension: a randomized trial

OBJECTIVES: Nonsteroidal anti-inflammatory drugs vary in their impact on blood pressure and the effect of lumiracoxib 100 mg once daily has not been studied previously. To examine whether lumiracoxib 100 mg once daily would result in lower 24-h mean systolic ambulatory blood pressure than ibuprofen 600 mg three times daily in osteoarthritis patients with controlled hypertension, a 4-week, randomized, double-blind, parallel-group study was conducted in 79 centres in nine countries. METHODS: Hypertensive osteoarthritis patients of 50 years at least whose office blood pressure was less than 140/90 mmHg on stable antihypertensive treatment were randomized to lumiracoxib (n = 394) 100 mg once daily or ibuprofen 600 mg three times daily (n = 393) and 24-h ambulatory blood pressure monitoring was performed at baseline and end of study. The primary outcome measure was a comparison of the change in 24-h mean systolic ambulatory blood pressure from baseline to week 4. Secondary analyses included other blood pressure-related endpoints and efficacy (pain) measurements. RESULTS: Compared with baseline, the 24-h mean systolic ambulatory blood pressure (least square mean) decreased in lumiracoxib-treated patients (-2.7 mmHg) and increased in ibuprofen-treated patients (+2.2 mmHg) at 4 weeks, estimated difference -5.0 mmHg (95% confidence interval -6.1 to -3.8) in favour of lumiracoxib. The 24-h mean diastolic ambulatory blood pressure changes were -1.5 mmHg (lumiracoxib), +0.5 mmHg (ibuprofen), difference -2.0 mmHg (95% confidence interval -2.7 to -1.3). Efficacy results were comparable. CONCLUSIONS: Treatment with lumiracoxib 100 mg once daily resulted in clinically significant lower blood pressure compared with ibuprofen 600 mg three times daily in osteoarthritis patients with well controlled hypertension.     

Role of allogeneic transplantation in chronic myeloid leukemia

The use of allogeneic hematopoietic stem cell transplantation for the treatment of chronic myeloid leukemia (CML) patients has changed dramatically during the past decade. It was the standard of care for all younger CML patients with a compatible donor before the introduction of imatinib. It is used now as a rescue treatment for patients for whom tyrosine kinase inhibitors have failed. Both treatments, tyrosine kinase inhibitors and allogeneic transplantation, are very powerful and able to control the disease in the long-term. It is therefore of great importance to know the place of each therapy and to integrate allogeneic hematopoietic stem cell transplantation in a risk-adapted way into the treatment plan of each individual patient.     

Chemotaxis of bone marrow derived eosinophils in vivo: A novel method to explore receptor‐dependent trafficking in the mouse

Here, we describe a novel method via which ex vivo cultured mouse bone marrow derived eosinophils (bmEos) can be adoptively transferred into recipient mice in order to study receptor‐dependent recruitment to lung tissue in vivo. Intratracheal instillation of recombinant human eotaxin‐2 (hCCL24) prior to introduction of bmEos via tail vein injection resulted in an approximately fourfold increase in Siglec F‐positive/CD11c‐negative eosinophils in the lungs of eosinophil‐deficient ΔdblGATA recipient mice compared with controls. As anticipated, bmEos generated from CCR3‐gene‐deleted mice did not migrate to the lung in response to hCCL24 in this model, indicating specific receptor dependence. BmEos generated from GFP‐positive BALB/c mice responded similarly to hCCL24 in vitro and were detected in lung tissue of BALB/c WT as well as BALB/c ΔdblGATA eosinophil‐deficient recipient mice, at approximately fourfold (at 5 h post‐injection) and approximately threefold (at 24 h postinjection) over baseline, respectively. Comparable results were obtained with GFP‐positive C57BL/6 bmEos responding to intratracheal hCCL24 in C57BL/6 ΔdblGATA recipient mice. The use of ex vivo cultured bmEos via one or more of these methods offers the possibility of manipulating bmEos prior to transfer into a WT or gene‐deleted recipient host. Thus, this chemotaxis model represents a novel and robust tool for pharmacological studies in vivo.     

CANVAS: a late onset ataxia due to biallelic intronic AAGGG expansions

Journal of Neurology - The ataxias are a group of disorders that manifest with balance, movement, speech and visual problems. They can arise due to dysfunction of the cerebellum, the vestibular...