Anterolateral ligament of the knee-Cadaver study in a Caucasian population

INTRODUCTION

Despite the recognized importance of the anterolateral ligament (ALL) in rotational stability of the knee, some studies still deny its role and even its existence. We studied the prevalence of the ALL in a Caucasian population, as well as its characteristics and anatomical relationships.

MATERIALS AND METHODS

The study was performed on 20 knees from 10 embalmed cadavers. A lateral approach, as described by Steven Claes, was used and the relations of the ALL with the lateral epicondyle, lateral inferior genicular artery, lateral meniscus, Gerdy's tubercle and fibular head were recorded. Its length and its width were also measured.

RESULTS

The ALL was identified in 16 knees. Its origin was at a distance inferior to 1mm posterior and proximal to the lateral femoral epicondyle and insertion within a mean distance of 2.1±0.6mm from de tibial articular surface, 20.6±1.3mm from the Gerdy's tubercle and 20.3±1.2mm from the fibular head. In all cases ALL presented mutual fibers with the lateral meniscus. The length was 35.8±4.6mm and the width was 4.2±1.3/4.9±1.0/6.5±1.5mm at its proximal, middle and distal third, respectively. No difference was found between gender and the dimensions of the ligament.

CONCLUSIONS

The ALL was found in 80% of the knees. Its origin is closely related to the lateral collateral ligament and its insertion is halfway between the fibular head and the Gerdy's tubercle. In all cases, we verified the connection between ALL and the lateral meniscus.

Non-linear conduction due to depinning of charge order domains in Fe3O2BO3

The oxyborate Fe₃O₂BO₃ presents a charge density wave (CDW) transition close to room temperature. As we show here, this is associated with a well defined anomaly in the specific heat. Below this transition, when applying in a single crystal of Fe₃O₂BO₃ a DC voltage above a temperature dependent threshold, a high current is liberated in this material. We study the conduction in single crystals of Fe₃O₂BO₃ with voltage applied parallel and perpendicular to the crystallographic c axis direction. The observed currents are attributed to the depinning of charge ordered domains above a threshold voltage V _T2 that gives rise to a collective conduction due to coherent domains. Compliance limited DC data shows that above a lower threshold voltage depinning is smooth and follows a power law scaling. Similar depinning with power law scaling is also revealed in the AC conductivity.

The impact of a standardized order set for the management of non-hip fragility fractures in a Fracture Liaison Service

We analysed the impact of a standardized order set empowering staff nurses to independently manage a Fracture Liaison Service over a 9-month period. Nurses identified between 30 and 70 % of non-hip fragility fractures to the unit in charge of management over time. The latter managed 58 % of referred patients.

INTRODUCTION

The main goal of this study was to evaluate the impact of a standardized order set empowering nurses to independently manage a fracture liaison service (FLS).

METHODS

Since November 2014, an order set allowed nurses of a Montreal hospital, Quebec, Canada to entirely manage an FLS on their own. Nurses followed an 6-h training program on-site. Emergency department (ED) and orthopaedic outpatient clinic (OC) nurses identified non-hip fragility fractures. Medical day treatment unit (MDTU) nurses were in charge of the management (investigation and treatment initiation). The list of patients, 50 years and older, with a fracture were retrieved for the period of November 2014 to July 2015. Performance was assessed with the rate of identification over time and the rate of management of non-hip fragility fractures.

RESULTS

Over the 9-month period, 346 patients of ≥50 years old were seen for a fracture, of which 190 met fragility criteria (excluding hip fractures). A sinusoid pattern of rates of identification between 30-70 % was observed over time. An average proportion of 58.1 % of fracture patients were managed by MDTU nurses.

CONCLUSIONS

A standardized order set legally allowing nurses to manage an FLS led to identification rates varying from 30-70 % and a management rate close to 60 % for referred patients over a 9-month period, which largely exceeds that of standard care. Identification was mostly compromised by difficulty integrating the order set into routine practice. Enforcement of the hospital policy on fragility fractures could help yield efficiency of identification of osteoporosis-related fractures by the staff.

Immunolocalization of cell wall polymers in grapevine (Vitis vinifera) internodes under nitrogen, phosphorus or sulfur deficiency

The impact on cell wall (CW) of the deficiency in nitrogen (-N), phosphorus (-P) or sulphur (-S), known to impair essential metabolic pathways, was investigated in the economically important fruit species Vitis vinifera L. Using cuttings as an experimental model a reduction in total internode number and altered xylem shape was observed. Under -N an increased internode length was also seen. CW composition, visualised after staining with calcofluor white, Toluidine blue and ruthenium red, showed decreased cellulose in all stresses and increased pectin content in recently formed internodes under -N compared to the control. Using CW-epitope specific monoclonal antibodies (mAbs), lower amounts of extensins incorporated in the wall were also observed under -N and -P conditions. Conversely, increased pectins with a low degree of methyl-esterification and richer in long linear 1,5-arabinan rhamnogalacturonan-I (RG-I) side chains were observed under -N and -P in mature internodes which, in the former condition, were able to form dimeric association through calcium ions. -N was the only condition in which 1,5-arabinan branched RG-I content was not altered, as -P and -S older internodes showed, respectively, lower and higher amounts of this polymer. Higher xyloglucan content in older internodes was also observed under -N. The results suggest that impairments of specific CW components led to changes in the deposition of other polymers to promote stiffening of the CW. The unchanged extensin amount observed under -S may contribute to attenuating the effects on the CW integrity caused by this stress. Our work showed that, in organized V. vinifera tissues, modifications in a given CW component can be compensated by synthesis of different polymers and/or alternative linking between polymers. The results also pinpoint different strategies at the CW level to overcome mineral stress depending on how essential they are to cell growth and plant development.

Agreement between physicians' and nurses' clinical decisions for the management of the fracture liaison service (4iFLS): the Lucky Bone™ program

We determined if nurses can manage osteoporotic fractures in a fracture liaison service by asking a rheumatologist and an internist to assess their clinical decisions. Experts agreed on more than 94 % of all nurses' actions for 525 fragility fracture patients, showing that their management is efficient and safe.

INTRODUCTION

A major care gap exists in the investigation of bone fragility and initiation of treatment for individuals who have sustained a fragility fracture. The implementation of a fracture liaison service (FLS) managed by nurses could be the key in resolving this problem. The aim of this project was to obtain agreement between physicians' and nurses' clinical decisions and evaluate if the algorithm of care is efficient and reliable for the management of a FLS.

METHODS

Clinical decisions of nurses for 525 subjects in a fracture liaison service between 2010 and 2013 were assessed by two independent physicians with expertise in osteoporosis treatment.

RESULTS

Nurses succeeded in identifying all patients at risk and needed to refer 27 % of patients to an MD. Thereby, they managed autonomously 73 % of fragility fracture patients. No needless referrals were made according to assessing physicians. Agreement between each evaluator and nurses was of >97 %. Physicians' decisions were the same in >96 %, and Gwet AC11 coefficient was of >0.960 (almost perfect level of agreement). All major comorbidities were adequately managed.

CONCLUSIONS

High agreement between nurses' and physicians' clinical decisions indicate that the independent management by nurses of a fracture liaison service is safe and should strongly be recommended in the care of patients with a fragility fracture. This kind of intervention could help resolve the existing care gap in bone fragility care as well as the societal economic burden associated with prevention and treatment of fragility fractures.

Relating Water Deficiency to Berry Texture, Skin Cell Wall Composition, and Expression of Remodeling Genes in Two Vitis vinifera L. Varieties

The cell wall (CW) is a dynamic structure that responds to stress. Water shortage (WS) impacts grapevine berry composition and its sensorial quality. In the present work, berry texture, skin CW composition, and expression of remodeling genes were investigated in two V. vinifera varieties, Touriga Nacional (TN) and Trincadeira (TR), under two water regimes, Full Irrigation (FI) and No Irrigation (NI). The global results allowed an evident separation between both varieties and the water treatments. WS resulted in increased anthocyanin contents in both varieties, reduced amounts in cellulose and lignin at maturation, but an increase in arabinose-containing polysaccharides more tightly bound to the CW in TR. In response to WS, the majority of the CW related genes were down-regulated in a variety dependent pattern. The results support the assumption that WS affects grape berries by stiffening the CW through alteration in pectin structure, supporting its involvement in responses to environmental conditions.

Dexamethasone shifts bone marrow stromal cells from osteoblasts to adipocytes by C/EBPalpha promoter methylation

Dexamethasone (Dex)-induced osteoporosis has been described as the most severe side effect in long-term glucocorticoid therapy. The decreased bone mass and the increased marrow fat suggest that Dex possibly shifts the differentiation of bone marrow stromal cells (BMSCs) to favor adipocyte over osteoblast, but the underlying mechanisms are still unknown. In this paper, we established a Dex-induced osteoporotic mouse model, and found that BMSCs from Dex-treated mice are more likely to differentiate into adipocyte than those from control mice, even under the induction of bone morphogenetic protein-2 (BMP2). We also discovered both in vitro and in vivo that the expression level of adipocyte regulator CCAAT/enhancer-binding protein alpha (C/EBPalpha) is significantly upregulated in Dex-induced osteoporotic BMSCs during osteoblastogenesis by a mechanism that involves inhibited DNA hypermethylation of its promoter. Knockdown of C/EBPalpha in Dex-induced osteoporotic cells rescues their differentiation potential, suggesting that Dex shifts BMSC differentiation by inhibiting C/EBPalpha promoter methylation and upregulating its expression level. We further found that the Wnt/beta-catenin pathway is involved in Dex-induced osteoporosis and C/EBPalpha promoter methylation, and its activation by LiCl rescues the effect of Dex on C/EBPalpha promoter methylation and osteoblast/adipocyte balance. This study revealed the C/EBPalpha promoter methylation mechanism and evaluated the function of Wnt/beta-catenin pathway in Dex-induced osteoporosis, providing a useful therapeutic target for this type of osteoporosis.

The in vitro and in vivo genotoxicity of isotretinoin assessed by cytokinesis blocked micronucleus assay and comet assay

Isotretinoin is a retinoic acid frequently used in monotherapy or combined with narrow-band ultraviolet B (NBUVB) irradiation to treat patients with acne and psoriasis vulgaris. As both diseases need frequent and/or prolonged therapeutic interventions, the study of the genotoxicity of retinoids becomes important. Our aim was to study the genotoxic effects of isotretinoin alone or combined with NBUVB. In vitro studies were performed in the absence of S9 metabolic activation using blood from five healthy volunteers, incubated 72 h with isotretinoin (1.2-20 μM) (i.e., at concentrations usually achieved in blood with therapeutic doses as well as at higher concentrations). In vivo studies were also performed using blood from two patients with acne and three patients with psoriasis vulgaris treated with isotretinoin in monotherapy (8 or 20mg/day) or combined with NBUVB (20mg isotretinoin/day+NBUVB). The genotoxic effect was evaluated by the cytokinesis-blocked micronucleus and the comet assays. Our studies showed that isotretinoin alone was not genotoxic when tested in human lymphocytes in vitro and in vivo. There was no clear genotoxic effect in psoriatic patients treated with isotretinoin and NBUVB. The in vitro studies showed that isotretinoin induced apoptosis and necrosis in human lymphocytes at higher doses.

Evaluation of antimicrobial edible coatings from a whey protein isolate base to improve the shelf life of cheese

The objective of this work was to evaluate the effectiveness of antimicrobial edible coatings to wrap cheeses, throughout 60 d of storage, as an alternative to commercial nonedible coatings. Coatings were prepared using whey protein isolate, glycerol, guar gum, sunflower oil, and Tween 20 as a base matrix, together with several combinations of antimicrobial compounds-natamycin and lactic acid, natamycin and chitooligosaccharides (COS), and natamycin, lactic acid, and COS. Application of coating on cheese decreased water loss (~10%, wt/wt), hardness, and color change; however, salt and fat contents were not significantly affected. Moreover, the antimicrobial edible coatings did not permit growth of pathogenic or contaminant microorganisms, while allowing regular growth of lactic acid bacteria throughout storage. Commercial nonedible coatings inhibited only yeasts and molds. The antimicrobial edible coating containing natamycin and lactic acid was the best in sensory terms. Because these antimicrobial coatings are manufactured from food-grade materials, they can be consumed as an integral part of cheese, which represents a competitive advantage over nonedible coatings.

Strength evaluation of a variable diameter acetabular trial implant under realistic loading conditions

A variable diameter acetabular trial implant (VDATI) was designed to reduce the costs related to cleaning, sterilisation and storage of surgical instruments used for total hip arthroplasty. The purpose of this study was to evaluate the mechanical strength of a functional prototype of the VDATI. Experimental testing was performed to identify if the VDATI can resist loading conditions similar to the ones occurring during the surgical procedure and to validate a finite element model (FEM) of the VDATI. The results highlighted the potential of the current concept of the VDATI and demonstrated the relevance to continue its development.

Finite element analysis of an acetabular trial implant

A variable diameter trial liner (VDTL) was designed to reduce the costs related to cleaning, sterilisation and storage of surgical instruments used for total hip arthroplasty. The purpose of this study was to develop a finite element model to evaluate the mechanical behavior of the VDTL before manufacturing of a functional prototype. The finite element analysis consists to identify the maximum stresses applied on the VDTL and compare these values to the yield strength of stainless steel 17-4 (540 MPa) to asses if the VDTL will resist to loading conditions similar to the ones occurring during the surgical procedure. The results demonstrated the need to improve the mechanical strength of the current concept of the VDTL. These results will serve as indications for upcoming design refinements.

Topical Imiquimod Treatment of Lentigo Maligna

Lentigo maligna (LM) is the in situ phase of lentigo maligna melanoma, which may progress to invasive melanoma if left untreated. It mainly occurs on sun-exposed areas of elderly patients. The lesions can be large and conventional surgery can be difficult, particularly on the face. Recent reports indicate that topical imiquimod 5% cream is effective in the treatment of LM. It may be an alternative when surgery or other classical treatments are not possible in elderly patients. We describe an 80-year-old Caucasian woman with a 10-year history of a histologically verified extensive LM of the face. She was treated with imiquimod 5% cream once daily. After four months it showed complete clinical response. One year after the treatment the patient was still free from recurrence.

Comparison of direct health care costs related to the pharmacological treatment of osteoporosis and to the management of osteoporotic fractures among compliant and noncompliant users of alendronate and risedronate: a population-based study

This population-based study aimed to compare direct health care costs related to the pharmacological treatment of osteoporosis and to the management of osteoporotic fractures among compliant and noncompliant users of alendronate and risedronate. During a 2-year follow-up period, compared to those with medication possession ratio (MPR) > or = 80%, women with MPR < 80% incurred significantly higher physician care costs and hospital care costs.

INTRODUCTION

This study aimed to compare direct health care costs related to the treatment of osteoporosis and osteoporotic fractures among compliant and noncompliant users of alendronate and risedronate.

METHODS

A cohort of 15,027 women having initiated alendronate or risedronate was identified. MPR and direct health care costs (physician care, hospital care, drugs) were assessed during a 2-year period. Regression models were used to estimate mean predicted cost for compliant (MPR > or = 80%) and noncompliant (MPR < 80%) women.

RESULTS

Mean predicted physician care cost (in Canadian dollars) was $51 among women with MPR < 80% and $34 among those with MPR > or = 80%: mean difference $17, 95% confidence interval (CI) $2-22. Mean predicted hospital care cost was $568 among women with MPR < 80% and $379 among those with MPR > or = 80%: mean difference $189, 95% CI $56-320. Mean predicted drug cost was $439 among women with MPR < 80% and $1,068 among those with MPR > or = 80%: mean difference $-639, 95% CI $-649 to -629.

CONCLUSION

Compared to compliant women, noncompliant women incurred significantly higher physician care and hospital care costs. Due to lower drug costs, total direct health care costs were lower among noncompliant women.

Evidence for two distinct pathways in TNFalpha-induced membrane and soluble forms of ICAM-1 in human osteoblast-like cells isolated from osteoarthritic patients

OBJECTIVE

The present study aimed to investigate the modulation of membrane-bound intercellular adhesion molecule-1 (mICAM-1) and soluble ICAM-1 (sICAM-1) expression by tumor necrosis factor-alpha (TNFalpha) in human osteoarthritic (OA) osteoblasts.

METHODS

Cultured human primary osteoblasts were stimulated with increasing concentrations of human recombinant TNFalpha. Expression of mICAM-1 and sICAM-1 was evaluated by immunocytochemistry, enzyme-linked immunosorbent assay and semi-quantitative reverse transcriptase-polymerase chain reaction. In addition, we investigated the molecular mechanisms underlying ICAM-1 induction by TNFalpha, focusing on the activation of the mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-kappaB) pathways.

RESULTS

Our data showed that TNFalpha dose-dependently increased mICAM-1 and sICAM-1 expression at the protein and mRNA levels in OA osteoblasts. The inhibitor of de novo mRNA synthesis, actinomycin D, suppressed TNFalpha-induced mICAM-1 and sICAM-1 expression. Upon examination of the signaling components, we found that TNFalpha was a potent activator of p38, p44/42, p54/46 MAPK, and IkappaBalpha (IkappaBalpha). The chemical inhibitors of p38, p44/42 MAPK, and NF-kappaB blocked TNFalpha-induced mICAM-1 expression but not that of sICAM-1. Transfection experiments revealed that p38 MAPK or IkappaB kinase alpha (IKKalpha) overexpression enhanced TNFalpha-induced mICAM-1 production. Furthermore, osteoblasts treatment with a chemical inhibitor of metalloproteinase-9 (MMP-9) activity, a proteolytic enzyme involved in ICAM-1 cleavage, evoked a significant 25% decrease of TNFalpha-induced sICAM-1 release.

CONCLUSION

Taken together, these findings illustrate the central role played by TNFalpha in the regulation of ICAM-1. We suggest that TNFalpha differentially regulates sICAM-1 and mICAM-1 expression and that sICAM-1 release involves, in part, the proteolytic cleavage of mICAM-1 by MMP-9. The capacity of the MMP-9 inhibitor to prevent sICAM-1 production may be useful for the development of novel therapeutic approaches relevant to OA.

Cyclosporin A treatment in severe childhood psoriasis

Though used occasionally, systemic therapies in severe childhood psoriasis have not been systematically investigated. Cyclosporin A (CysA) is effective in adults with severe psoriasis but there are no extensive data regarding the efficacy and safety of its use in childhood psoriasis. In this paper, we describe six children aged between 11 months and 13 years (average: 7.6 years) treated with CysA microemulsion formulation for severe psoriasis, who had been unresponsive to other treatments. The CysA dose ranged from 2 to 4 mg/kg/day, for periods varying from 8 to 105 weeks (mean: 54 weeks). Dose tapering was gradual after lesion improvement and adjusted according to clinical response. Adjuvant therapy with topical steroids, vitamin D3 ointments, coal tar preparations or anthralin was used in all children. Acitretin was used in three patients for short periods. The children were regularly monitored for serum renal and liver function and blood pressure. Improvement of skin lesions was achieved after between 4 and 30 (mean: 12) weeks of treatment, with complete remission in three children. Relapse of lesions occurred in the other children during CysA reduction, but they responded to a dose increase. The treatment was found to be well tolerated and with no significant side-effects. CysA can be used in carefully selected and monitored patients and may represent an alternative tool for severe episodes of psoriasis in children, when other therapies are unsuccessful.

Subchondral and trabecular bone metabolism regulation in canine experimental knee osteoarthritis

OBJECTIVE

To determine trabecular and subchondral bone metabolic changes in experimental canine osteoarthritis (OA).

METHODS

OA was induced in 19 dogs by transection of the anterior cruciate ligament (ACL) of the right knee through a stab wound. Dogs were sacrificed at 8 (n=7) and 12 weeks (n=12) after surgery. Non-operated normal dogs (n=6) were used as controls. After sacrifice, samples were obtained from the weight-bearing area of medial tibial plateaus. Explants and cell cultures were prepared from subchondral and trabecular bone. Osteocalcin (Oc), cellular alkaline phosphatase (ALPase), urokinase plasminogen-activator (uPA), prostaglandin E2 (PGE2), metalloproteinase (MMP) and nitric oxide (NO) were measured using standard procedures.

RESULTS

ALPase production was significantly increased only at week 12 in subchondral and trabecular bone, while an increase in Oc was noted at week 8. uPA and MMP activity were increased significantly at week 12 in subchondral bone, while PGE2 levels were significantly higher in subchondral and trabecular bone at week 12 compared to normal. A decrease in NO production appeared late at week 12 in trabecular bone, whereas NO levels from subchondral bone were significantly increased compared to normal at week 8.

DISCUSSION

Intense bone remodeling takes place in both subchondral and trabecular bone in the knee following ACL transection. This process seems to occur around week 12, although Oc and NO appeared to be involved earlier at 8 weeks. These results suggest that not only subchondral but also trabecular bone metabolism is altered in this OA model.

Treatment with licofelone prevents abnormal subchondral bone cell metabolism in experimental dog osteoarthritis

OBJECTIVES

To determine if treatment with licofelone, a combined 5-lipoxygenase and cyclo-oxygenase inhibitor, in vivo in experimental dog osteoarthritis can modify bone cell metabolism in long term in vitro subchondral osteoblast cell cultures (Ob).

METHODS

Group 1 received sectioning of the anterior cruciate ligament (ACL) of the right knee with no active treatment (placebo group). Groups 2 and 3 received sectioning of the ACL of the right knee, and were given licofelone (2.5 or 5.0 mg/kg daily by mouth, respectively) for eight weeks beginning the day after surgery. Primary Ob were prepared from the subchondral bone plate. Levels of phenotypic markers (alkaline phosphatase activity, osteocalcin release), and urokinase plasminogen activator (uPA) and insulin-like growth factor-1 (IGF-I) levels, were evaluated in each group. Lastly, prostaglandin E(2) (PGE(2)) and leucotriene B(4) levels were evaluated.

RESULTS

No significant differences in alkaline phosphatase activity or osteocalcin release from Ob between the three groups, under either basal or 1,25(OH)(2)D(3) induction were seen. In contrast, treatment with licofelone reduced uPA and IGF-I levels in Ob. PGE(2) levels, which were still raised in the placebo group, were decreased sharply by licofelone. A relationship was found between licofelone treatment and either the reduction in the size of lesions on tibial plateaus or the levels of uPA, IGF-I, or PGE(2).

CONCLUSIONS

Licofelone treatment prevents and/or delays the abnormal metabolism of subchondral osteoblasts in this model. Licofelone reduced PGE(2) levels after long term Ob, suggesting that the reduction in uPA and IGF-I levels is linked, at least in part, to this reduction.

Modulation of IL-1beta, IL-6, TNF-alpha and PGE(2) by pharmacological agents in explants of membranes from failed total hip replacement

Introduction and goal Proinflammatory cytokines and prostaglandin E(2) (PGE(2)) play an important role in the pathophysiology of osteolysis and implant loosening. The aim of this study was to evaluate the role of pharmacological agents in the inhibition of Interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) and PGE(2) in explants of interface membranes from failed total hip replacements (fTHR). Material and methods Membranes from fTHR were retrieved (N=20) and explants were incubated for 72h in the absence or presence of tenidap at three different concentrations (5, 20 or 50 microg/ml) or diclofenac (125 microg/l). IL-1beta, IL-6, TNF-alpha, and PGE(2) levels were measured in the culture medium using ELISA Capture or EIA kits. Statistical analysis was done using the Mann-Whitney U-test. Results A statistically significant inhibition in IL-1beta synthesis was found at tenidap concentrations of 20 microg/ml (71.3%, P< 0.05) and 50 microg/ml (79.3%,P< 0.02). Tenidap reduced IL-6 levels by 90.4% at 20 microg/ml (P< 0.005) and 96.0% (P< 0.05) at 50 microg/ml. Tenidap also reduced the synthesis of TNF-alpha by 66.9% (P< 0.05) and 77.4% at concentrations of 20 microg/ml and 50 microg/ml. Tenidap had a marked suppressive effect of over 90% (P< 0.0001) on PGE(2) synthesis in all three concentrations. Diclofenac (125 microg/l) decreased PGE(2) production by 95% (P< 0.0001), but had no significant effect in IL-1beta, IL-6, and TNF-alpha levels in the culture medium. Conclusion The ability to simultaneously suppress the release of proinflammatory cytokines and PGE(2) may help control osteolysis and prevent aseptic loosening of THR. This effect could increase implant longevity and lead the way to the pharmacological treatment of this pathology.

Peroxisome proliferator-activated receptor gamma activators inhibit MMP-1 production in human synovial fibroblasts likely by reducing the binding of the activator protein 1

OBJECTIVE

To investigate the expression and activity of PPARgamma in human synovial fibroblasts and the effects of PPARgamma agonists on the expression of MMP-1. The molecular mechanisms by which PPARgamma agonists modulate MMP-1 expression were also examined.

METHODS

PPARgamma expression and activity were measured using reverse-transcription polymerase chain reaction (RT-PCR) and transient transfection assays. Human synovial fibroblasts were cultured with IL-1beta in the absence or presence of PPARgamma activators, and the expression and production of MMP-1 were evaluated by Northern blot and ELISA, respectively. The effect of 15d-PGJ(2) on MMP-1 promoter activation was analysed in transient transfection experiments, while electrophoretic mobility shift assays were performed to study the binding activity of the transcription factor AP-1.

RESULTS

PPARgamma was expressed and transcriptionally functional in human synovial fibroblasts. PPARgamma activators (15d-PGJ(2) and BRL 49653) inhibited IL-1beta-induced MMP-1 synthesis in a dose-dependent manner. Similarly, both activators inhibited IL-1-induced MMP-1 mRNA expression. Activation of the human MMP-1 promoter was also attenuated by 15d-PGJ(2), indicating that the inhibitory effect of 15d-PGJ(2) occurs at the transcriptional level. Interestingly, 15d-PGJ(2) reduced both basal and IL-1beta-induced AP-1 binding activity.

CONCLUSIONS

These data indicate that PPARgamma agonists inhibit MMP-1 gene expression by transcriptional mechanisms, and suggest that they may be useful in reducing joint tissue destruction.

Chondrocyte death in experimental osteoarthritis is mediated by MEK 1/2 and p38 pathways: role of cyclooxygenase-2 and inducible nitric oxide synthase

OBJECTIVE

To explore the mechanisms responsible for in situ induction of chondrocyte death in experimental dog osteoarthritic (OA) cartilage. The roles of 2 mitogen activated protein kinases (MAPK), MEK 1/2 and p38, nuclear factor-kappaB (NF-kappaB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and the caspase cascade were investigated.

METHODS

OA knee cartilage was obtained from dogs that had received sectioning of the anterior cruciate ligament and were sacrificed 12 weeks after surgery. Cartilage explants were cultured in different inhibitors: Z-DEVD-FMK (caspase 3 inhibitor), Z-LEHD-FMK (caspase 9 inhibitor), PD 98059 (MEK 1/2 inhibitor). SB 202190 (p38 inhibitor), SN-50 (NF-kappaB inhibitor), NS-398 (COX-2 inhibitor), N-iminoethyl-l-lysine (L-NIL) (iNOS inhibitor). Cartilage specimens were stained for TUNEL reaction and immunostained using specific antibodies for caspase 3, COX-2, iNOS, and nitrotyrosine. Morphometric analyses were performed.

RESULTS

The significant level of chondrocyte death in OA cartilage was markedly decreased by caspase 3 and caspase 9 inhibitors. The two MAPK inhibitors, but not the NF-kappaB inhibitor, decreased chondrocyte death concomitant with the levels of caspase 3 and iNOS. COX-2 level was reduced by all 3 inhibitors. Specific inhibition of either COX-2 or iNOS reduced the level of chondrocyte death and caspase 3. There was evidence of crosstalk between these 2 latter systems; specific inhibition of COX-2 reduced the iNOS level, and selective inhibition of iNOS reduced COX-2 expression. COX-2 and iNOS seem to function in a positive autoregulatory manner that triggers transcription of their own biosynthetic machinery, since the specific inhibition of each system downregulates its expression.

CONCLUSION

This study shows that in the early lesions of experimental OA cartilage in situ, activation of the caspase cascade is responsible for induction of chondrocyte death. Marked inhibition of cell death by caspase inhibitors indicates a significant participation of apoptosis in the phenomenon. This phenomenon is linked to the activation of at least 2 major kinase pathways, MEK 1/2 and p38. These pathways are responsible for upregulating the expression of iNOS and COX-2, each of which seems essential for the induction of apoptosis. Data are provided about possible regulation and interregulation of the COX-2 and iNOS systems by prostaglandin E2 and NO.

Structural transition and pair formation in Fe3O2BO3

We observe for the first time a structural phase transition in the oxyborate Fe3O2BO3 which occurs along three leg ladders present in this material. X-ray diffraction shows that this transition at 283 K is associated with a new phase where atomic displacements occur in alternate directions perpendicular to the axis and within the plane of the ladders. Magnetic data show that these displacements lead to the formation of singlet pairs which dissociate close to the structural transition. Anomalies in the transport properties also occur close to 283 K showing that the structural transition is related to a charge ordering phenomenon in a low dimensional structure.

In vivo dual inhibition of cyclooxygenase and lipoxygenase by ML-3000 reduces the progression of experimental osteoarthritis: suppression of collagenase 1 and interleukin-1beta synthesis

OBJECTIVE

To study the therapeutic effectiveness of ML-3000, a new antiinflammatory drug that has balanced dual inhibitory activity against 5-lipoxygenase and cyclooxygenase, on the development of lesions in the experimental osteoarthritis (OA) dog model, and to determine the action of ML-3000 on the synthesis of collagenase 1 in cartilage and interleukin-1beta (IL-1beta) in synovial membrane.

METHODS

The anterior cruciate ligament of the right stifle joint of 21 mongrel dogs was sectioned with a stab wound. Dogs were divided into 3 groups: group 1 (n = 7) received placebo; groups 2 (n = 7) and 3 (n = 7) were treated with therapeutic dosages of oral ML-3000 at 2.5 mg/kg/day and 5 mg/kg/day, respectively. The dogs began receiving medication the day after surgery and were killed 8 weeks later. The size and grade of cartilage erosions on both the condyles and plateaus were evaluated, and the severity of the cartilage lesions and synovial inflammation was examined histologically. Levels of collagenase 1 in cartilage and IL-1beta in the synovial membrane were measured by immunohistochemistry. In addition, levels of prostaglandin E2 (PGE2) in the synovial fluid and leukotriene B4 (LTB4) in cultured synovial membrane explants were determined using specific enzyme immunoassays.

RESULTS

Serum levels of ML-3000 in treated dogs were within the therapeutic range. ML-3000 significantly decreased the size and grade of the cartilage lesions in tibials and plateaus, compared with placebo. At the histologic level, the severity of cartilage lesions was also decreased in the ML-3000-treated dogs versus the placebo-treated dogs in both the condyles and the plateaus. All 3 OA groups exhibited a notable and similar level of synovial inflammation. ML-3000 significantly decreased the level of PGE2 in synovial fluid and LTB4 production by synovium. It also markedly reduced the levels of collagenase 1 in cartilage and IL-1beta in synovial membrane.

CONCLUSION

ML-3000 significantly reduced the development of lesions in experimental dog OA. The drug acts by reducing the synthesis of the inflammation mediators PGE2 and LTB4 and catabolic factors such as collagenase 1 and IL-1beta, which are known to play an important role in the pathophysiology of OA lesions. The effect of the drug on catabolic factors could possibly be related to its inhibitory action on LTB4 synthesis.

[Efficacy and safety of nebulized L-epinephrine associated with dexamethasone in postintubation laringitis]

OBJECTIVE: To assess the efficacy and safety of the use of nebulized L-epinephrine associated with dexamethasone in postintubation laryngitis. METHODS: We carried out a prospective, randomized, double-blind, placebo controlled study with two cohorts of patients with postintubation laryngitis graded 3 to 6 by Downes-Raphaelly score during two years. Our population was divided into two groups: A and B; both groups received intravenous dexamethasone and two doses of nebulized saline; however, only group B received L-epinephrine. The efficacy was assessed by Downes-Raphaelly score. The side effects of L-epinephrine were evaluated according to the occurrence of cardiac arrhythmia, increased blood pressure, and average heart rate of group B in comparison to group A. RESULTS: Twenty-two patients were included in group A (average score = 4.8) and 19 in group B (average score = 5.2). During treatment, 3 patients in group A presented a score of 8 and were reintubated. This group also showed higher mean clinical scores than group B during the first two hours of the protocol; these results were not statistically significant. No side effects were observed due to epinephrine. The gas blood measurements were adequate in both groups, but better in the control group. CONCLUSIONS: We did not observe increased efficacy for the treatment of postintubation laryngitis when nebulized L-epinephrine was used simultaneously with intravenous dexamethasone. Some indicators, however, did present a favorable trend when combined therapy was used and should be submitted to further evaluation.

Diacerein reduces the excess synthesis of bone remodeling factors by human osteoblast cells from osteoarthritic subchondral bone

OBJECTIVE

Although cartilage degradation characterizes osteoarthritis (OA), there is evidence that remodeling of subchondral bone in this disease is a contributing factor. Therapeutic strategies to modify the metabolism of subchondral bone osteoblasts may be indicated to treat OA. We studied the effects of diacerein and rhein on the metabolic and inflammatory variables of OA subchondral osteoblasts.

METHODS

Human OA primary subchondral osteoblast cells were used. The effect of diacerein and rhein at therapeutic concentrations (5-20 microg/ml) was determined by osteoblast phenotypic factors, alkaline phosphatase, osteocalcin, and cAMP; on metabolic agents urokinase plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and insulin-like growth factor-1 (IGF-1); and on inflammatory mediators interleukin 6 (IL-6), prostaglandin E2 (PGE2), and cyclooxygenase-2 (COX-2).

RESULTS

Diacerein and rhein did not affect either basal and 1,25(OH)2D3 induced alkaline phosphatase or parathyroid hormone (PTH) stimulated cAMP formation. Conversely, they dose dependently and statistically inhibited 1,25(OH)2D3 induced osteocalcin release, a situation explained by a reduction of mRNA levels for osteocalcin. Of the metabolic factors, they inhibited the production of uPA, with rhein showing slightly more potency; inhibitions of 69% and 57% were reached at the highest concentration (20 microg/ml) of rhein and diacerein, respectively. Both drugs also inhibited the PAI-1 level, albeit at a much lower level than for uPA. Interestingly, determination of the uPA/PAI1 ratio revealed that both drugs inhibited it about 55%, suggesting a decrease in uPA activity. In contrast, IGF-1 levels only increased slightly when cells were treated with rhein but not with diacerein. A transient dose dependent effect was found on IL-6 production; an inhibition was noted at low drug concentrations, which returned to basal levels at the highest concentration tested. PGE2 levels increased exponentially and were related to a concomitant increase in COX-2 levels in response to both drugs.

CONCLUSION

Our data indicate that diacerein and rhein do not appear to affect OA subchondral bone cells' basal cellular metabolism, yet both agents reveal a direct effect at reducing the synthetic activities of osteoblasts, which could be responsible for abnormal subchondral bone remodeling occurring during the course of OA.

Endogenous prostaglandin E2 and insulin-like growth factor 1 can modulate the levels of parathyroid hormone receptor in human osteoarthritic osteoblasts

Subchondral bone sclerosis may be important for the onset and/or progression of cartilage loss/damage in human osteoarthritis (OA). OA osteoblasts are resistant to parathyroid hormone (PTH) stimulation, which could explain bone sclerosis via the inhibition of PTH-dependent catabolism. Here, we investigated the molecular mechanism(s) responsible for reduced PTH-dependent cyclic adenosine monophosphate (cAMP) synthesis in OA subchondral osteoblasts. Although cholera toxin (CTX) increased basal cAMP formation in these cells, it failed to stimulate PTH-dependent cAMP synthesis, whereas pertussis toxin (PTX) did not inhibit basal cAMP, yet diminished PTH-dependent cAMP production. Binding of 125I-PTH indicated lower PTH receptor levels in OA than in normal osteoblasts (-50.5 +/- 9.5%). This could be attributed to either reduced expression of the PTH receptor (PTH-R) or altered recycling of existing pools of receptors. Reverse-transcription polymerase chain reaction (RT-PCR) analysis indicated decreased PTH-R messenger RNA (mRNA) levels in OA cells that were highly variable (ranging from -10% to -60%), a situation that reflects disease severity. Interestingly, OA osteoblasts produced more prostaglandin E2 (PGE2) than normal osteoblasts, and using naproxen, a cyclo-oxygenase inhibitor, increased PTH-dependent cAMP formation to a level similar to normal osteoblasts. Because heterologous desensitization can explain a decrease in PTH binding but cannot account for reduced PTH-R expression, we looked at the possible effect of insulin-like growth factor 1 (IGF-1) on this parameter. Blocking IGF-1 signaling with a neutralizing receptor antibody increased 125I-PTH binding in both normal and OA osteoblasts. Conversely, treatments with IGF-1 receptor (IGF-1R) antibody only slightly increased the levels of PTH-R mRNA whereas the addition of IGF-1 significantly reduced PTH-R mRNA levels (-24.1 +/- 7.1%), yet neither PGE2 nor naproxen modified PTH-R levels. These results suggest that both IGF-1 signaling and PGE2 formation repress PTH-dependent response in OA osteoblasts, a situation that can contribute to abnormal bone remodeling and bone sclerosis in OA.

Tufted hair folliculitis after scalp injury

We describe the case of a 38-year-old epileptic man with tufted hair folliculitis. The condition started 5 years ago after a scalp laceration that had been sustained 3 months earlier during an epileptic crisis. There then appeared a circumscribed inflammatory bulging lesion (with exudation and crusts) that evolved to scarring alopecia with tufts of 20 to 30 apparently normal hair shafts. Results of bacteriologic examination of pus extruding from the dilated follicular ostia revealed Staphylococcus aureus. The cutaneous pathologic examination showed polymorphous inflammatory exudate in the upper and mid dermis, which was mostly perifollicular, and the presence of normal and independent follicles in the deep dermis, which, while ascending, converged to a common dilated follicular channel. The patient was treated successively with oral flucloxacillin, erythromycin, ciprofloxacin, and amoxicillin/clavulanic acid and with topical application of erythromycin, clindamycin, povidone iodine, and ketoconazole. Transient improvement was followed by recurrence and enlargement of the affected area.

Carprofen simultaneously reduces progression of morphological changes in cartilage and subchondral bone in experimental dog osteoarthritis

OBJECTIVE

To examine the effect of a nonsteroidal antiinflammatory drug, carprofen, on the structure and metabolism of cartilage and subchondral bone in the experimental osteoarthritic (OA) canine model.

METHODS

Experimental Groups 1 and 2 received a sectioning of the anterior cruciate ligament (ACL) of the right stifle joint, and were administered carprofen (2.2 and 4.4 mg/kg/twice daily/po, respectively) for 8 weeks beginning 4 weeks postsurgery. Group 3 received ACL sectioning and no treatment. Group 4 was composed of unoperated normal dogs. Cartilage macroscopic lesions were assessed, and their histological severity was graded. Specimens of subchondral bones were fixed, decalcified, and stained with hematoxylin/eosin. The level of metalloprotease (MMP) activity in cartilage was measured. Osteoblast cells were prepared from the subchondral bone. The level of synthesis of osteoblast biomarkers (osteocalcin, alkaline phosphatase), as well as urokinase plasminogen activator (uPA) activity and insulin-like growth factor (IGF-1) in the culture medium, was estimated.

RESULTS

Carprofen treatment decreased the width of osteophytes (p < 0.01), the size of cartilage lesions, and the histologic severity of cartilage lesions (p < 0.008). There was no difference in the levels of MMP activity in cartilage between OA and carprofen treated groups. In OA dogs, the subchondral bone plate was thinner and was the site of an extensive remodeling process with numerous lacunae. Dogs treated with carprofen showed a marked decrease in the remodeling activity with normal plate thickness, and subchondral bone morphology resembling that of normal dogs. Osteoblasts from untreated OA dogs showed slightly higher alkaline phosphatase activities and osteocalcin release that reverted back to normal upon carprofen treatment. Moreover, uPA activity and IGF-1 levels were increased in OA dogs and were significantly reduced in carprofen treated dogs.

CONCLUSION

Under therapeutic conditions, treatment with carprofen could reduce the progression of early structural changes in experimental OA. Carprofen treatment also delays and/or prevents the abnormal metabolism of subchondral osteoblasts in this model. The hypothesis of a possible link between the protective effect of carprofen and its effect on subchondral bone is of interest in the context of therapeutic intervention.

Gene therapy for osteoarthritis: new perspectives for the twenty-first century

Morphologic changes observed in osteoarthritis include cartilage erosion and a variable degree of synovial inflammation. Proinflammatory cytokines such as interleukin-1 beta, locally produced by the inflamed synovium, also likely contribute to these alterations. Despite an extensive armamentarium and numerous surgical options, osteoarthritis remains incurable, and an improved approach in the treatment of this disease is imperative. Drug delivery is a major weakness of existing antiarthritic therapies. Local delivery of antiinflammatory cytokines or the in vivo induction of their expression using gene transfer may provide a novel approach for the treatment of osteoarthritis. Evidence of the efficacy of gene therapy in osteoarthritis remains very scarce. To the authors' knowledge, there is no clinical research protocol en route for the treatment of osteoarthritis using gene therapy. The authors present the only two studies that have proved successful in treating animal models of osteoarthritis using gene therapy, and propose an overview of several strategies for the development of gene therapy in osteoarthritis treatment in the future.

Selective inhibition of inducible nitric oxide synthase reduces progression of experimental osteoarthritis in vivo: possible link with the reduction in chondrocyte apoptosis and caspase 3 level

OBJECTIVE

To evaluate the in vivo therapeutic efficacy of N-iminoethyl-L-lysine (L-NIL), a selective inhibitor of inducible nitric oxide synthase, on the progression of structural lesions in the experimental canine model of osteoarthritis (OA), and to explore the effect of L-NIL on the level of chondrocyte apoptosis and of important proteins involved in the apoptotic phenomenon, i.e., caspase 3 (inducer) and Bcl-2 (inhibitor).

METHODS

The OA model was created by sectioning the anterior cruciate ligament. Dogs were placed into 4 experimental groups: unoperated dogs that received no treatment (controls), operated (OA) dogs that received placebo treatment, OA dogs that received oral L-NIL at 10 mg/kg/day, and OA dogs that received oral L-NIL at 1.0 mg/kg/day. In both L-NIL groups, treatment started immediately after surgery. The OA dogs were killed at 12 weeks after surgery.

RESULTS

OA dogs treated with L-NIL showed a reduction in the size of osteophytes and a significant decrease in the severity of macroscopic and histologic cartilage lesions on both condyles and plateaus, compared with untreated OA dogs. L-NIL treatment also significantly decreased metalloprotease activity in cartilage. Immunohistochemical analysis revealed that the levels of chondrocyte apoptosis, caspase 3, and Bcl-2 were markedly increased in OA cartilage (P < 0.0001). A positive correlation between the levels of chondrocyte apoptosis and levels of caspase 3 was found (r = 0.54, P < 0.0001). OA dogs treated with the higher dosage L-NIL showed significantly reduced levels of chondrocyte apoptosis (P < 0.003) and caspase 3 (P < 0.04), but no effect on the increased level of Bcl-2 was demonstrated.

CONCLUSION

This study shows that L-NIL reduces the progression of experimental OA. This effect could be related to a reduced level of chondrocyte apoptosis and is likely mediated by a decrease in the level of caspase 3 activity. A sparing effect of L-NIL on the increased level of Bcl-2 may also be a contributing factor.

[Mechanical evaluation of a ligament fixation system for ACL reconstruction at the tibia in a canine cadaver model]

OBJECT

Excellent fixation of an artificial ligament in bone is mandatory for initial stability. ACL reconstruction with the LARS artificial ligament may fail if anchorage to bone is inadequate. The weak metaphyseal bone of the proximal tibia is prone to inadequate fixation. This study evaluates the initial mechanical stability of two techniques with an interference screw on the tibial side of an ACL reconstruction with the LARS ligament.

METHODS

Six left tibias were obtained from 1 to 3 year old mongrel dog weighing 20 to 26 kg. ACL straight line reconstruction according to the technique described by J.P. Laboureau was performed with a 4.5 mm drill. Two tunnels were created in the tibia, one oblique and one transverse, the latter 2 cm below the former. Reconstruction was done with a 30-fiber LARS ligament and a 5.2 mm x 15 mm conical titanium cannulated interference screw. Group I had an interference screw in the oblique tunnel and group II had an interference screw in the transverse tunnel. Pull-out tests were performed parallel to the oblique tunnel on an Instron 8521 machine at a speed of 5 mm per minute until failure. The oblique tunnel was tested first then the transverse tunnel.

RESULTS

Group I (n = 6): sliding value = 238 +/- 115 N. Group II (n = 6): sliding value = 998 +/- 148 N. This is statistically significant (p < 0.001, student t-test).

CONCLUSION

One interference screw in a transverse tibial tunnel for ACL reconstruction with the LARS ligament is 4 times more resistant on loading and impact than an oblique screw.

Pharmacologic therapy of osteoarthritis

This article presents a brief review of the most current therapies that are used for the relief of the symptoms related to osteoarthritis. The agents used either systematically or locally are described, providing the rationale for their usage in the treatment of osteoarthritis. Moreover, new therapies that have reached clinical evaluations and that can possibly reduce or stop the progression of the disease--namely the inhibitors of metalloproteases--are presented. Overall, it is obvious that significant progress has been made toward the development of new therapeutic agents to reduce the symptoms as well as the structural changes of the disease.

Selective inhibition of inducible nitric oxide synthase in experimental osteoarthritis is associated with reduction in tissue levels of catabolic factors

OBJECTIVE

We used the experimental dog model of osteoarthritis (OA) to examine the in vivo effects of N-iminoethyl-L-lysine (L-NIL), a selective inhibitor of the inducible nitric oxide synthase (iNOS), on the tissue level and distribution of interleukin-1beta (IL-1beta), collagenase-1, stromelysin-1, cyclooxygenase-2 (COX-2), iNOS and nitrotyrosine, through immunohistochemical and morphometric analysis.

METHODS

Cartilage and synovial membrane specimens were obtained from 3 experimental groups of dogs: Group I--unoperated dogs that received no treatment; Group II--dogs subjected to a sectioning of the anterior cruciate ligament of the right knee and given no treatment; and Group III--operated dogs that received oral treatment with L-NIL (10 mg/kg twice daily/po) for 10 weeks starting immediately after surgery. The operated dogs were killed 10 weeks post-surgery. The tissue distributions of IL-1beta, metalloproteases (MMP), COX-2, iNOS and nitrotyrosine were documented by immunohistochemistry using specific antibodies, and quantified by morphometric analysis.

RESULTS

In cartilage, the cell scores (percentage of chondrocytes staining positive for the antigen) for iNOS and 3-nitrotyrosine were dramatically enhanced in OA specimens compared to normal (p < 0.0001). However, the cartilage of dogs treated with L-NIL showed significantly lower cell scores for iNOS (p<0.0001, condyle; p<0.001, plateau), nitrotyrosine (p<0.0004; p<0.0001) and COX-2 (p<0.0001; p<0.001) compared to that of untreated OA dogs. Similar findings were observed for collagenase-1 and stromelysin-1, where the increased cell scores of these 2 MMP in OA cartilage were reduced after treatment with L-NIL (collagenase: p<0.002, condyle; p<0.0003, plateau; stromelysin: p<0.006; p<0.0001). The increased cell scores for the IL-1beta, COX-2, iNOS and nitrotyrosine found in the synovial lining and mononuclear cell infiltrate of operated animals were also found to be markedly reduced in dogs treated with L-NIL.

CONCLUSION

Our study demonstrates for the first time in vivo in an experimental model of OA, that a selective inhibition of iNOS by L-NIL and the subsequent decreased production of NO also results in a marked decrease in production of major catabolic factors such as MMP, IL-1beta and peroxynitrite, as well as a reduction in COX-2 expression.

Reduction in the structural changes of experimental osteoarthritis by a nitric oxide inhibitor

OBJECTIVE

To evaluate the in-vivo therapeutic efficacy of N -iminoethyl-L-Lysine (L-NIL), a selective inhibitor of inducible nitric oxide synthase (iNOS) in a dose response study, on the progression of lesions in the experimental osteoarthritic (OA) dog model.

DESIGN

The sectioning of the anterior cruciate ligament of the right stifle joint of mongrel dogs was done by a stab wound. Dogs were separated into experimental groups: Group 1 received no treatment, Groups 2, 3, and 4 received oral L-NIL (0.3, 1 or 10mg/kg/day, respectively) starting immediately after surgery. The OA dogs were killed at 12 weeks after surgery.

RESULTS

Macroscopically, L-NIL decreased the size of the cartilage lesions on condyles and plateaus. The histologic severity of the cartilage lesions was decreased in the L-NIL-treated dogs. This effect was more pronounced at the highest dosage tested (3 and 10mg/kg/day).

CONCLUSIONS

This study confirms the effectiveness of L-NIL, a selective inhibitor of iNOS, in attenuating the progression of experimental OA. It also clearly shows that the effect is dose-dependent.

[Resection of the anterior cruciate ligament of the knee using arthroscopy induces arthrosis in dogs. Validity of the Pond-Nuki model]

INTRODUCTION AND GOAL

The dog model of osteoarthritis is the one most used for the study of the pathophysiology of this disease, given its resemblance to human osteoarthritis. Although the percutaneous section of the ligament is the most known technique, variability of and iatrogenic lesions might occur. The goal of this study was to validate the arthroscopic technique regarding the osteaorthritic lesions found in the percutaneous Pond-Nuki dog model.

METHODS

The arthroscopic section of the canine anterior cruciate ligament (ACL) was compared to the percutaneous technique. Six dogs were operated percutaneously (Group I) and another six by arthroscopy (Group II). At eight weeks, animals were sacrificed and analysis were done on the osteophytes (mm) and cartilage lesions [macroscopy (Pelletier scale: grade 0-4, and size, mm2)] and [microscopy (Mankin scale: 0-14)] on femoral condyles and tibial plateaus.

RESULTS

Osteophytes (Group I: 3.4 mm, Group II: 4.4 mm) and cartilage lesions (grade: 2.07 and 1.67; size: 27.9 and 33.9 m, respectively) on both femoral condyles and tibial plateaus are similar and not statistically different. Total microscopic scoring for both groups (6.2 and 6.5, respectively) are also similar and not statistically significant.

DISCUSSION

Experimental osteoarthritis induced by arthroscopic transection of the ACL in dogs is characterised by macroscopic and microscopic lesions that resemble those found after percutaneous stab transection. Arthroscopic technique is more reliable and the present results allow its validation regarding the classical percutaneous technique.

Diacerhein and rhein reduce the interleukin 1beta stimulated inducible nitric oxide synthesis level and activity while stimulating cyclooxygenase-2 synthesis in human osteoarthritic chondrocytes

OBJECTIVE

To evaluate the in vitro effects of diacerhein, a new drug for the treatment of osteoarthritis (OA), and its active metabolite, rhein, on the production of nitric oxide (NO), prostaglandin (PGE2), cyclooxygenase-2 (COX-2), as well as the production and expression of the inducible nitric oxide synthase (iNOS) in human OA chondrocytes. These results were compared to those of the nonsteroidal antiinflammatory drug (NSAID) naproxen.

METHODS

Human OA chondrocytes were incubated in the presence or absence of 25 units/ml recombinant human interleukin-1beta (rhIL-1beta) with or without therapeutic concentrations of diacerhein and rhein at 5, 10, and 20 microg/ml and naproxen at 30 and 90 microg/ml. Effect of the drugs was also tested on both OA chondrocytes and cartilage explants on increasing IL-1beta concentration (0-100 units/ml). The NO and PGE2 levels were determined in the culture medium using the Griess reaction and a specific ELISA, respectively. Production of COX-2 and synthesis and expression of iNOS were quantitated by Western blot and Northern blot, respectively.

RESULTS

The IL- 1beta induced NO production was inhibited by both diacerhein and rhein in a time and dose dependent fashion, with statistical significance reached at the therapeutic concentration of 20 microg/ml. A decrease over 80% was found at 24, 48, and 72 h incubation. This was consistent for both chondrocytes and cartilage explants even in the presence of high IL-1beta concentration (100 units/ml). Moreover, this effect appeared to result from iNOS transcriptional and/or post-transcriptional events as indicated by a decrease in this enzyme level for both the mRNA and protein. Naproxen, however, showed only a slight inhibition of IL-1beta induced NO production at the highest dose used, 90 microg/ml. A maximum decrease of 23% in IL-1beta induced NO production was recorded after a 72 h incubation. In contrast to naproxen, which abrogated PGE2 and had no effect on COX-2 synthesis, rhein and diacerhein at 5 and 10 microg/ml produced an enhancement in their levels.

CONCLUSION

Diacerhein and rhein, in contrast to an NSAID, are potent inhibitors of IL-1beta induced NO production by chondrocytes and cartilage, without reducing PGE2 production.

Collagenase-1 and collagenase-3 synthesis in normal and early experimental osteoarthritic canine cartilage: an immunohistochemical study

OBJECTIVE

The coexistence of different collagenases in cartilage suggests the possibility of specific roles for these enzymes in the degradation of the collagen network in osteoarthritis (OA). We investigated the in situ synthesis and distribution of collagenase- and collegenase-3 in normal and early experimental OA cartilage.

METHODS

The OA model was created on 12 mongrel dogs by sectioning the anterior cruciate ligament of the right stifle joint with a stab wound. Dogs were divided into 3 groups of 4 animals each, and sacrificed at 4, 8, and 12 weeks, respectively. A 4th group (n = 4) of unoperated dogs was used as control. Articular cartilage from femoral condyles and tibial plateaus was examined histologically to grade severity of lesions, and immunohistochemical and morphometric analyses were performed to detect the presence of chondrocytes producing collagenase-1 and -3.

RESULTS

In OA dogs, the histologic severity of lesions increased with time, being most severe at 8 and 12 weeks after surgery. In cartilage from OA compared to unoperated dogs, the immunoreactivity was 5-9 times higher (p < 0.0002) for collagenase-1, and 3-6 times higher (p < 0.0002) for collagenase-3, in both femoral condyles and tibial plateaus. Although the cell score increased throughout the cartilage, comparison of the superficial and upper intermediate layers (superficial) with the lower intermediate and deep layers (deep) revealed a significantly higher level for collagenase-1 (p < 0.007) in the superficial layers, contrary to the collagenase-3 data, which indicated a higher level (p < 0.007) in the deep layers. For collagenase- , the cell score increased steadily up to the 12th week, and for collagenase-3, the elevation peaked at 8 weeks. Correlation between the histologic severity and cell score in cartilage specimens from unoperated and OA dogs revealed the highest coefficient for collagenase- at the superficial layers (r = 0.69, p < 0.0001), while for collagenase-3, this was noted at the deep layers (r = 0.65, p < 0.0004).

CONCLUSION

The number of chondrocytes involved in the synthesis of collagenase-1 and collegenase-3 increases dramatically in the early phase of OA. However, the difference in the topographic distribution of these enzymes, as well as the variation in their correlation pattern, may reflect a different function allocated for each collagenase in the OA cartilage degradation process.

[Trends in HIV/AIDS-related knowledge, attitudes, and practices in a Rio de Janeiro slum population]

The study aims to evaluate the present stage of knowledge, attitudes, and behavior related to HIV/AIDS in the population of Rio de Janeiro's Rocinha slum, the target of a control program over the last 6 years. We interviewed two hundred and ten people of both sexes, ranging from 13 to 49 years of age, and the results were compared with those of a study conducted in 1990 with the same methodology and sample size. The analysis showed an association between single males and more preventive behavior. Misconceptions about the role of mosquito bites and blood donation in the transmission of HIV persist, almost in the same proportion. Comparing the two samples, there was a significant increase in the role of HIV/AIDS education provided by schools, and the study also identified an increase in the rates and regularity of condom use. More efforts should be made to reduce misconceptions about HIV transmission and the vulnerability of couples. The study also highlights the need for more consistent policies related to condom distribution to the general population.

[Therapeutic of septic children with purpuric presentation with two antibiotic schedules]

OBJECTIVE: The authors evaluate the therapeutic efficacy of two antibiotic schedules, ceftriaxone alone and the combined use of ampicillin and chloramphenicol, in the treatment of septic children with purpuric presentation.METHODS: A randomized open clinical trial was conducted including septic children with purpuric presentation treated at a pediatric intensive care unit from April 1988 to June 1992. All cases with systemic purpura standing for less than a week were included in one of two groups, except for those recently hospitalized or with previous hemorrhagic disturbs. Patients in group A received ampicillin and chloramphenicol and those in group B were given ceftriaxone. Quantitative parameters were adopted to compare the efficacy of the two antibiotic schedules: sensitivity of bacteria isolated at blood and liquor cultures, complications, therapeutic procedures, period of hospitalization, and sequelae.RESULTS: 19 cases were included in the group A and 16 in group B, both homogenous on clinical-laboratorial aspects. The parameters evaluated did not show different efficacy between the two antimicrobial schedules tested, except for the number of complications observed during hospitalization, which was higher among the children that received ampicillin and chloramphenicol. The overall mortality for the patients treated was 13.8%, excluded the undernourished. CONCLUSIONS: The authors verify similar clinical therapeutic efficacy with the combined use of ampicillin and chloramphenicol or ceftriaxone, as observed previously. It must be pointed that the number of complications detected during hospitalization were higher in the group that received the combined antibiotic schedule. Low mortality in the present study may be attributed to the early diagnosis and therapeutic measures adopted at the pediatric intensive care unit.

Reduced progression of experimental osteoarthritis in vivo by selective inhibition of inducible nitric oxide synthase

OBJECTIVE

To evaluate the in vivo therapeutic efficacy of N-iminoethyl-L-lysine (L-NIL), a selective inhibitor of inducible nitric oxide synthase (iNOS), on the progression of lesions in an experimental osteoarthritis (OA) dog model. The effect of L-NIL on metalloprotease activity, levels of interleukin-1beta (IL-1beta), prostaglandin E2 (PGE2), and nitrite/nitrate in synovial fluid was determined.

METHODS

The OA model was created by sectioning the anterior cruciate ligament of the right stifle joint of mongrel dogs by a stab wound. Dogs were separated into experimental groups: Group 1 was made up of unoperated dogs that received no treatment, group 2 were operated dogs with no treatment, and group 3 were operated dogs that received oral L-NIL (10 mg/kg/twice daily) starting immediately after surgery. The OA dogs were killed at 10 weeks after surgery.

RESULTS

Experiments showed that dog OA cartilage explants in culture produced an increased amount of NO (nitrite). Immunohistochemical study demonstrated that this was due to an increased level of iNOS in chondrocytes. OA dogs treated with L-NIL showed a reduction in the incidence of osteophytes compared with the untreated OA dogs (58% versus 92%) as well as in their size (mean +/- SEM 1.92 +/- 0.58 mm versus 5.08 +/- 0.66 mm). Macroscopically, L-NIL decreased the size of the cartilage lesions by approximately 50% both on condyles and plateaus. The histologic severity of both the cartilage lesions and synovial inflammation was significantly decreased in the L-NIL-treated dogs. Treatment with L-NIL also significantly decreased both collagenase and general metalloprotease activity in the cartilage and the levels of IL-1beta, PGE2, and nitrite/nitrate in synovial fluid.

CONCLUSION

This study demonstrated the effectiveness of a selective inhibitor of iNOS, L-NIL, in attenuating the progression of experimental OA. The data suggest that L-NIL may act by reducing the activity of metalloproteases in cartilage and the production of IL-1beta by synovium, both of which are known to play a major role in the pathophysiology of OA structural changes.

Study of NADH stability using ultraviolet-visible spectrophotometric analysis and factorial design

The chemical stability of nicotinamide adenine dinucleotide coenzyme (NADH/NAD+) and its derivatives (NADPH/NADP+) was investigated using changes in the UV-visible absorption spectra of these compounds. The spectra of cofactor (reduced form) were monitored at 340 nm wavelength in different buffers, showing a faster degradation in phosphate buffer. This was assigned to the adduct formation between phosphate and NADH (pyridine ring). The three-factor-two-level factorial design study evaluated the contributions: buffers (phosphate and Pipes 0.1 M), pH's (6.8 and 7.8), and temperature (25 and 30 degrees C). The freshly prepared aqueous solutions of coenzyme were analyzed after 40 min under the different conditions (eight assays in triplicate) of the experiment. The main observed effects of the NADH oxidation were, in increasing order, pH, temperature, and buffer without appreciable interactive effects. Therefore, it was verified that the better conditions for cofactor use were alkaline media employing Pipes buffer or its derivatives and low temperatures.

The effects of tenidap on canine experimental osteoarthritis: II. Study of the expression of collagenase-1 and interleukin 1beta by in situ hybridization

OBJECTIVE

To examine the effect of tenidap on the expression of collagenase- and interleukin 1beta (IL-1beta) genes in experimental canine osteoarthritis (OA).

METHODS

The anterior cruciate ligaments of the right stifle joints of experimental dogs were sectioned by a stab wound incision and tissues samples were taken. Four dogs had received no treatment, 4 were treated with oral omeprazole (20 mg/day), and another 4 were treated with tenidap (3 mg/kg/bid) and omeprazole (20 mg/day). The dogs received medication for 8 weeks; all dogs were sacrificed at the end of this period. Tissues from 4 healthy dogs were used as controls. IL-1beta and collagenase-1 gene expression were measured in synovial membrane (synovial lining cells and mononuclear cell infiltrate) and collagenase-1 expression in cartilage using in situ hybridization techniques. Results were calculated as the percentage of cells expressing the gene, and expressed as cell score.

RESULTS

The collagenase-1 cell score in the full thickness samples was significantly higher in OA cartilage than in normal cartilage, both in condyles and plateaus (p < 0.0002). Tenidap treated dogs showed a significantly lower cell score in femoral condyles and tibial plateaus in the superficial (p < 0.0002), deep (p < 0.005, p < 0.002, respectively), and full thickness (p < 0.0002) layers compared to OA dogs. No staining for collagenase-1 was observed in normal membrane. In OA synovial membrane, the collagenase-1 cell score was high in both the synovial lining cells and mononuclear cell infiltrate. Tenidap treated dogs showed a significantly lower score compared to OA tissue in both the synovial lining cells (p < 0.03) and the mononuclear cell infiltrate (p < 0.03). The relative decrease in the collagenase-1 cell score in the tenidap treated dogs was more pronounced in the mononuclear cell infiltrate. Staining for IL-1beta was observed in only a few lining cells in normal synovial membrane from unoperated dogs. In OA synovial membrane from untreated dogs, staining for IL-1beta was intense and was found in all dog specimens. The cell score was significantly higher in OA lining cells (p < 0.03) and mononuclear cell infiltrate (p < 0.03) compared to normal. In tenidap treated dogs, the score for IL-1beta was significantly lower than in OA, both in synovial lining cells (p < 0.03) and mononuclear cell infiltrate (p < 0.03).

CONCLUSION

Tenidap significantly reduced in vivo expression of collagenase-1 and IL-1beta in experimental OA. These data are an extension of our previous study and showed that tenidap exerts its protective effects on OA lesions, likely by reducing the catabolic pathways of the disease.