A critical role for collagen II in cartilage matrix degradation: Collagen II induces pro‐inflammatory cytokines and MMPs in primary human chondrocytes

We report a process that results in the acceleration of matrix degradation in human articular cartilage, a phenomenon commonly observed in osteoarthritis (OA). The study was conducted by (1) examining the potential of collagen II in modulating the gene expression profile of primary human chondrocytes (PHCs), and (2) investigating the involvement of pro‐inflammatory signaling cascades. We first tested the collagen II‐dependent induction of pro‐inflammatory cytokines and matrix metalloproteinases (MMPs) in PHCs. PHCs were incubated with or without monomeric (i.e., nonfibrillar) collagen II. Cells were then analyzed by RT‐PCR for the expression of MMP1, MMP3, MMP13, MMP14, and IL‐1β. ELISA was used to quantify IL‐6 and IL‐8 release. To examine the influence of collagen II signaling, specifically the role of MAPK p38, a p38‐inhibitor was added prior to collagen treatment. Changes in IκB concentration were monitored by immunoblot analysis to detect NFκB signaling. Results indicated that incubation of PHCs with collagen II did produce a dose‐dependent induction of MMP1, MMP3, MMP13, MMP14, as well as cytokines IL‐1β, IL‐6, and IL‐8. At the same time, inhibition of p38 and IκB degradation revealed that collagen II‐dependent gene induction also involves MAPK p38 and NFκB signaling. Thus, we provide evidence for a collagen II‐dependent feed‐forward mechanism whereby collagen II induces first MMPs and pro‐inflammatory cytokines and then release of collagen II fragments from mature collagen II fibers. This, in turn, induces more pro‐inflammatory cytokines and MMPs, and the process is repeated, which results in the acceleration and perpetuation of cartilage matrix degradation. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:65–70, 2009     

The Effects of botulinum toxin A on muscle histology during distraction osteogenesis

Distraction osteogenesis is a highly successful method of bone formation, yet muscle fibrosis and contractures can result in significant morbidity. In the current study, we investigate the efficacy of botulinum toxin A in preventing fibrosis and potentially increasing muscle development in distracted muscles. Fifteen New Zealand White rabbits underwent tibial distraction at 1.5 mm/day until a 20% gain was achieved. Treatment groups were divided by drug (saline or botulinum toxin) and target muscle (gastrocnemius or tibialis anterior). Two additional control animals received no treatment. Bromeodeoxyuridine was delivered continuously throughout the 8‐week experiment, and following muscle harvest. Tissues were stained for BrdU, Pax‐7, vimentin, and haematoxylin and eosin staining. Mitotic activity increased in all distracted animals; however, in the animals receiving botulinum toxin A injections into the gastrocnemius, the antagonist tibialis anterior suffered up to 9% less fibrosis than distraction alone (p = 0.024). Use of botulinum A toxin did not appear to promote or improve neogenesis of muscle fibers, nor did it decrease fibrosis in the injected muscles. It appears from this study, and a previously published study on the effects of this toxin on muscle function, that botulinum A toxin maybe of some benefit in decreasing morbidity in the antagonist muscle but not the muscle injected with the toxin. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:310–317, 2009     

Recombinant human platelet‐derived growth factor BB (rhPDGF‐BB) and beta‐tricalcium phosphate/collagen matrix enhance fracture healing in a diabetic rat model

Diabetes mellitus is a common systemic disease that has been associated with poor fracture healing outcomes. The mechanism through which diabetes impairs bone regeneration is unknown. One possible mechanism may be related to either decreased or uncoordinated release of local growth factors at the fracture site. Indeed, previous studies have found reduced platelet‐derived growth factor (PDGF) levels in the fracture callus of diabetic rats, suggesting that local application of PDGF may overcome the negative effects of diabetes and promote fracture healing. To test this hypothesis, low (22 µg) and high (75 ug) doses of recombinant human PDGF‐BB (rhPDGF‐BB) were applied directly to femur fracture sites in BB Wistar diabetic rats that were then compared to untreated or vehicle‐treated animals. rhPDGF‐BB treatment significantly increased early callus cell proliferation compared to that in control specimens. Low dose rhPDGF‐BB treatment significantly increased callus peak torque values (p < 0.05) at 8 weeks after fracture as compared to controls. High dose rhPDGF‐BB treatment increased callus bone area at 12 weeks postfracture. These data indicate that rhPDGF‐BB treatment ameliorates the effects of diabetes on fracture healing by promoting early cellular proliferation that ultimately leads to more bone formation. Local application of rhPDGF‐BB may be a new therapeutic approach to treat diabetes‐impaired fracture healing. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 1074–1081, 2009     

Validation of a new method for determination of cup orientation in THA

Our goal was to validate accuracy, consistency, and reproducibility/reliability of a new method for determining cup orientation in total hip arthroplasty (THA). This method allows matching the 3D‐model from CT images or slices with the projected pelvis on an anteroposterior pelvic radiograph using a fully automated registration procedure. Cup orientation (inclination and anteversion) is calculated relative to the anterior pelvic plane, corrected for individual malposition of the pelvis during radiograph acquisition. Measurements on blinded and randomized radiographs of 80 cadaver and 327 patient hips were investigated. The method showed a mean accuracy of 0.7 ± 1.7° (?3.7° to 4.0°) for inclination and 1.2 ± 2.4° (?5.3° to 5.6°) for anteversion in the cadaver trials and 1.7 ± 1.7° (?4.6° to 5.5°) for inclination and 0.9 ± 2.8° (?5.2° to 5.7°) for anteversion in the clinical data when compared to CT‐based measurements. No systematic errors in accuracy were detected with the Bland–Altman analysis. The software consistency and the reproducibility/reliability were very good. This software is an accurate, consistent, reliable, and reproducible method to measure cup orientation in THA using a sophisticated 2D/3D‐matching technique. Its robust and accurate matching algorithm can be expanded to statistical models. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1583–1588, 2009     

Novel quinolone CHM‐1 induces apoptosis and inhibits metastasis in a human osterogenic sarcoma cell line

Novel 2‐phenyl‐4‐quinolone compounds have potent cytotoxic effects on different human cancer cell lines. In this study, we examined anticancer activity and mechanisms of 20‐fluoro‐6,7‐methylenedioxy‐2‐phenyl‐4‐quinolone (CHM‐1) in human osterogenic sarcoma U‐2 OS cells. CHM‐1‐induced apoptosis was determined by flow cytometric analysis, DAPI staining, Comet assay, and caspase inhibitors. CHM‐1‐inhibited cell migration and invasion was assessed by a wound healing assay, gelatin zymography, and a Transwell assay. The mechanisms of CHM‐1 effects on apoptosis and metastasis signaling pathways were studied using Western blotting and gene expression. CHM‐1 induced G2/M arrest and apoptosis at an IC₅₀ (3 µM) in U‐2 OS cells and caspase‐3, ‐8, and ‐9 were activated. Caspase inhibitors increased cell viability after exposure to CHM‐1. CHM‐1‐induced apoptosis was associated with enhanced ROS generation, DNA damage, decreased ΔΨ_m levels, and promotion of mitochondrial cytochrome c release. CHM‐1 stimulated mRNA expression of caspase‐3, ‐8, and ‐9, AIF, and Endo G. In addition, CHM‐1 inhibited cell metastasis at a low concentration (<3 µM). CHM‐1 inhibited the cell metastasis through the inhibition of MMP‐2, ‐7, and ‐9. CHM‐1 also decreased the levels of MAPK signaling pathways before leading to the inhibition of MMPs. In summary, CHM‐1 is a potent inducer of apoptosis, which plays a role in the anticancer activity of CHM‐1. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1637–1644, 2009     

Dynamic changes in salivary cortisol and secretory immunoglobulin A response to acute stress

Psychological stress leads to the secretion of cortisol. While this psychoneuroendocrine response helps to maintain physiological as well as psychological homeostasis under stress, exaggerated release of cortisol can suppress aspects of immune function and have negative effects on health. The present study set out to investigate the dynamic changes in salivary secretory immunoglobulin A (sIgA) and cortisol before and after acute stress, and to analyse the relationship between sIgA and cortisol trend. Thirty‐five healthy subjects took part in this study. All subjects underwent an acute stress test (mental arithmetic task). Salivary cortisol and sIgA responses were assessed repeatedly before the stress test, immediately after the stress test and 20 min after the stress test. The levels of salivary cortisol and sIgA both significantly increased after the acute mental arithmetic challenge. However, the increase of sIgA is transient; the sIgA fall was significantly correlated with the cortisol rise during the 20 min after stress (r = 0.569, p < 0.001). These results may help determine the timing of effective intervention in order to reduce the hypersecretion of cortisol and improve mucosal immune function. Copyright © 2008 John Wiley & Sons, Ltd.     

Rectal fistulae after salvage high‐intensity focused ultrasound for recurrent prostate cancer after combined brachytherapy and external beam radiotherapy

OBJECTIVE

To report on the high rectal fistula rate associated with salvage high‐intensity focused ultrasound (HIFU) after the failure of combined brachytherapy and external beam radiotherapy (EBRT) for prostate cancer; salvage ablative therapy for prostate cancer is indicated when there is local recurrence after RT, brachytherapy or their combination.

PATIENTS AND METHODS

We retrospectively reviewed all men with prostate cancer treated with HIFU between 1 March 2005 and 31 May 2007, and identified five men treated after the failure of both brachytherapy and EBRT for localized prostate cancer.

RESULTS

Three of the five men had iodine‐seed implantation brachytherapy combined with EBRT as primary treatment, one had high‐dose rate brachytherapy combined with EBRT and one had salvage iodine‐seed brachytherapy for failed EBRT. Three of the five patients developed a recto‐urethral fistula after HIFU.

CONCLUSIONS

The high rate of recto‐urethral fistula formation in this group might reflect an impaired blood supply or HIFU‐associated near‐field heating of the rectal wall. Tissue viability and healing might affect this group regardless of the salvage method. Careful patient selection and avoidance of rectal diagnostic biopsies might minimize the risk. Emerging ablative therapies regarded as less invasive than traditional therapies must be used with caution.     

How successful is the conservative management of pelvi‐ureteric junction obstruction in adults?

OBJECTIVE

To assess the conservative management of pelvi‐ureteric junction obstruction (PUJO), according to severity, accepted in paediatric urology but rarely reported in adults.

PATIENTS AND METHODS

A series of 23 patients (median age 58 years, 17 men and six women) with asymptomatic or minimally symptomatic PUJO were managed conservatively. The patients’ age, preference and comorbidities were considered. The diagnosis of PUJO was based on intravenous urography and isotopic renography. After stringently reviewing the renograms based on relative renal function (RRF) and output efficiency (OE), 15 patients had an OE consistent with definitive PUJO. One patient had no further imaging due to associated comorbidities. Ten patients had right PUJO, three left and one with bilateral PUJO, with unilateral conservative management. The follow‐up included annual renography and clinical consultation. Laparoscopic pyeloplasty was considered for patients with a >10% loss of RRF and/or <40% RRF during the follow‐up.

RESULTS

Overall, 14 of 15 patients had renograms during the follow‐up. The mean RRF of the affected kidney at diagnosis was 48.6% which marginally decreased to 46.7% after a median (range) follow‐up of 44 (23–75) months. The RRF of 11 patients remained stable and in three decreased significantly (median 11% RRF), requiring pyeloplasty. None of the patients became symptomatic throughout the follow‐up.

CONCLUSION

In asymptomatic adults the conservative management of PUJO appears to be safe during a short‐ to medium‐term follow‐up. We recommend that patients are regularly followed with renography and seen promptly should they become symptomatic. A longer follow‐up is needed in a larger group to confirm these findings.     

A critical assessment of the prognostic value of clear cell,papillary and chromophobe histological subtypes in renal cell carcinoma: a population‐based study

OBJECTIVE

To assess the magnitude of the effect of histological subtype (HS, the three most common being clear cell, papillary and chromophobe) on cause‐specific mortality (CSM) from renal cell carcinoma (RCC).

PATIENTS AND METHODS

Univariable and multivariable Cox regression models included data from 11 618 patients treated with nephrectomy between 1988 and 2004 in nine Surveillance Epidemiology and End Results registries. We tested whether HS represents an independent predictor of CSM, and whether HS adds to the ability of other variables to predict CSM. The covariates comprised age, year of surgery, T stage, nodal status, M stage and Fuhrman grade.

RESULTS

In a multivariable model predicting CSM, HS was an independent predictor (P = 0.03), but failed to improve the accuracy of the model (+0.1% gain when HS was included in the model).

CONCLUSION

Although we confirmed that HS is an independent predictor for CSM, there was no gain in accuracy when HS was added to standard predictors of CSM. From a practical perspective, this implies that patients with clear cell, papillary and chromophobe HS share similar natural histories after nephrectomy, provided that other cancer characteristics are accounted for. From a statistical perspective, in multivariable models of CSM, the clear cell, papillary and chromophobe HS might be included as a single entity.