Disruption of human limb morphogenesis by a dominant negative mutation in CDMP1.

Chondrodysplasia Grebe type (CGT) is an autosomal recessive disorder characterized by severe limb shortening and dysmorphogenesis. We have identified a causative point mutation in the gene encoding the bone morphogenetic protein (BMP)-like molecule, cartilage-derived morphogenetic protein-1 (CDMP-1). The mutation substitutes a tyrosine for the first of seven highly conserved cysteine residues in the mature active domain of the protein. We demonstrate that the mutation results in a protein that is not secreted and is inactive in vitro. It produces a dominant negative effect by preventing the secretion of other, related BMP family members. We present evidence that this may occur through the formation of heterodimers. The mutation and its proposed mechanism of action provide the first human genetic indication that composite expression patterns of different BMPs dictate limb and digit morphogenesis.

[Urological comorbidities in patients with rheumatoid arthritis : literature review]. / Urologische Begleiterkrankungen bei Patienten mit rheumatoider Arthritis : Literaturübersicht.

Patients with rheumatoid arthritis (RA) have an increased risk of urolithiasis which is further negatively impacted by a reduced bone density. Interstitial cystitis also tends to occur more often in patients with rheumatic diseases. The high incidence of bacterial urogenital infections is influenced by the use of immunomodulating drugs. Many RA patients have to undergo numerous tests until a diagnosis is reached and are then treated as outpatients on a tightly controlled schedule. Despite a closely controlled rheumatological follow-up, urological screening and determination of a baseline prostate-specific antigen (PSA) value (in men over 45 years old) should not be neglected. In patients with an increased risk of renal and bladder neoplasms or when such a diagnosis is known, the benefit of long-term use of high doses of non-steroidal anti-inflammatory drugs (NSAID, aspirin type) should be carefully weighed up with a risk profile and after specialist urological assessment. Patients who suffer from sexual dysfunction due to physical limitations and prolonged medical therapy should undergo urological and gynecological assessment to exclude contributing causes. The use of aphrodisiacs and erection-enhancing drugs (e.g. PDE5 inhibitors, local injection with prostaglandins and vacuum therapy) require prior approval by a medical specialist and also cardiovascular stability. Acute urinary retention is more common in chronic inflammatory musculoskeletal diseases.

Cartilage-derived morphogenetic proteins and osteogenic protein-1 differentially regulate osteogenesis.

Cartilage-derived morphogenetic proteins-1 and -2 (CDMP-1 and CDMP-2) are members of the bone morphogenetic protein (BMP) family, which play important roles in embryonic skeletal development. We studied the biological activities of recombinant CDMP-1 and CDMP-2 in chondrogenic and osteogenic differentiation and investigated their binding properties to type I and type II serine/threonine kinase receptors. In vivo, CDMP-1 and CDMP-2 were capable of inducing dose-dependently de novo cartilage and bone formation in an ectopic implantation assay. In vitro studies using primary chondrocyte cultures showed that both CDMP-1 and CDMP-2 stimulated equally de novo synthesis of proteoglycan aggrecan in a concentration-dependent manner. This activity was equipotent when compared with osteogenic protein-1 (OP-1). In contrast, CDMPs were less stimulatory than OP-1 in osteogenic differentiation as evaluated by alkaline phosphatase activity and expression levels of bone markers in ATDC5, ROB-C26, and MC3T3-E1 cells. CDMP-2 was the least osteogenic in these assays. Receptor binding studies of CDMP-1 and CDMP-2 revealed that both have affinity for the BMP receptor type IB (BMPR-IB) and BMPR-II, and weakly for BMPR-IA. Moreover, using a promoter/reporter construct, transcriptional activation signal was transduced by BMPR-IB in the presence of BMPR-II upon CDMP-1 and CDMP-2 binding. Our data show that distinct members of the BMP family differentially regulate the progression in the osteogenic lineage, and this may be due to their selective affinity for specific receptor complexes.

Effects of cartilage-derived morphogenetic proteins and osteogenic protein-1 on osteochondrogenic differentiation of periosteum-derived cells.

Localization studies and genetic evidence have implicated cartilage-derived morphogenetic proteins-1, -2 (CDMP-1 and CDMP-2), and osteogenic protein-1 (OP-1) in the osteochondrogenic differentiation of mesenchymal progenitor cells during embryonic development and in postnatal life. Based on their expression pattern and the evidence that periosteum contains mesenchymal cells in the cambium layer that can undergo bone and cartilage formation, we hypothesized that CDMPs and OP-1 may be involved in long bone development and fracture healing. To test this hypothesis, periosteum-derived cells from young calves were cultured as monolayers under serum-free conditions with and without the addition of recombinant CDMP-1, CDMP-2 and OP-1. Phenotypic analysis indicate that periosteum-derived cell populations prepared, expanded, and cultured under the conditions described below, constitutively express messenger RNAs for the bone markers osteocalcin, osteopontin and collagen type I, and the chondrogenic markers collagen type II and aggrecan as determined by RT-PCR. Moreover, histologic examinations showed positive staining for alcian blue and alkaline phosphatase (AP). Treatment of periosteum-derived cells with CDMPs and OP-1 resulted in a dose-dependent increase of cell proliferation; CDMP-2 was less active in this regard. Furthermore, all growth factors enhanced osteogenic differentiation as assessed by a time- and dose-dependent stimulation of AP activity and OP-1 increased messenger RNA expression for osteocalcin and collagen type I. We further examined the effects of CDMPs and OP-1 on chondrogenic differentiation of periosteum-derived cells. Both CDMPs and OP-1 stimulated (35)S-sulfate incorporation into newly synthesized macromolecules with OP-1 having a more pronounced stimulatory effect when compared with CDMP-1 and CDMP-2. Our results indicate that distinct members of the BMP-family increase the mitotic and metabolic activity of periosteum-derived cells. The enhancement of both the chondrogenic and osteogenic differentiation suggests that these growth factors might contribute to the local regulation of bone formation and fracture repair.

Laboratory monitoring of thromboprophylaxis with low molecular weight and standard heparin.

This study was made to evaluate assays for monitoring of low dose heparin thromboprophylaxis and to evaluate its efficacy in reduction of hypercoagulation. Patients with medical diseases scheduled for routine thromboprophylaxis were subcutaneously treated with either 5.000 anti XaU low molecular weight (LMW) heparin once daily (n = 20) or 5.000 IU standard (ST) heparin 3 times daily (n = 19). On days 1,2,3, before, 1 and 4 hours after heparin injection APTT, TCT, anti Xa, Heptest, thrombin-antithrombin complexes (TAT), and D-Dimer levels were measured. In the LMW heparin group, median values of APTT and TCT slightly increased after heparin and the ranges of pre- and postinjection values showed extensive overlap. However, values of anti Xa and Heptest markedly increased, showing complete separation of ranges. In the ST heparin group neither APTT, TCT, anti Xa, nor Heptest were significantly different comparing pre- and postheparin values. Half of the patients in both groups had subclinical hypercoagulation at baseline (TAT greater than 5 ng/ml, D-Dimer greater than 200 ng/ml). On day 3 of prophylaxis this percentage was not significantly decreased. Moreover, several patients in both groups increased in TAT and D-Dimer. In the LMWheparin group, negative correlations between body weight and 4 h postinjection heparin levels were found (anti Xa R = -0.50, Heptest R = -0.31) and between 1 h postinjection heparin and TAT and D-Dimer levels 3 h later (TAT-anti Xa R = -0.58, TAT-Heptest R = -0.64, D-Dimer-anti Xa R = -0.32, D-Dimer-Heptest R = -0.33).(ABSTRACT TRUNCATED AT 250 WORDS)

Sucrose permeability as a marker for NSAID-induced gastroduodenal injury.

OBJECTIVE: To evaluate sucrose permeability as a non-invasive test for the monitoring of upper gastrointestinal mucosal damage (uGMD) in patients treated with NSAIDs. METHODS: 40 patients with non-inflammatory joint pain were enrolled in a prospective study. Before and after 14 days of ibuprofen treatment (3 x 400 mg/day), the rates of urinary sucrose excretion after an oral sucrose load were assessed. Individuals with increased sucrose permeability underwent endoscopy. RESULTS: 8 patients (20%) showed abnormal sucrose permeability before taking any NSAID. In 5/20 patients (25%) who completed 2 weeks of ibuprofen medication, sucrose excretion increased above the normal level. Endoscopic examination and biopsy revealed mild uGMD, but no ulceration in 8/11 (72%) patients with increased permeability to this marker. CONCLUSION: Sucrose permeability testing is a sensitive procedure for research protocols on NSAID-induced gastropathy. Since this test also seems to detect slight and clinically insignificant mucosal damage, however, its use in clinical decision-making regarding gastroprotective medication is limited.

Emergency intubation with the Combitube in a grossly obese patient with bull neck.

A grossly obese patient with bull neck required immediate intubation. Endotracheal intubation failed because visualization of the vocal cords was not possible. As an alternative, the Combitube was inserted without difficulty and the patients lungs were ventilated via the Combitube until tracheotomy was performed on the following day. The patient survived and was discharged alive from the hospital 5 weeks later. The Combitube has gained worldwide interest and is now included in the Guidelines of the American Heart Association and the American Society of Anesthesiologists.

[Low dosage long-term treatment with recombinant alpha interferon induces in hairy cell leukemia continuous complete remission]. / Niedrig dosierte Langzeitbehandlung mit rekombinantem Interferon alpha führt bei der Haarzellenleukämie zu einer anhaltenden kompletten Remission.

Long-term treatment with recombinant interferon alpha (IFN) leading to complete remission in a patient with hairy cell leukaemia is presented. Four months after the beginning of treatment with IFN, the parameters of the peripheral blood had normalized. In spite of a continuous dose reduction (to a dose of 1 Mio. U/week) remission could be maintained during the six years of treatment. Two years after the start of treatment with IFN, a metastasizing carcinoma of the prostate was diagnosed, leading to death after four years. With regard to the hairy cell leukaemia, the patient was free of symptoms and the obduction confirmed the complete remission: the histological examination of bone marrow, spleen, liver and lymph nodes showed no more signs of hairy cell leukaemia. This case report shows that long-term treatment with IFN in some cases is effective to induce and to maintain complete remission in hairy cell leukaemia.

Salmon calcitonin and calcium in the treatment of male osteoporosis: the effect on bone mineral density.

OBJECTIVE: To assess the effectiveness of salmon calcitonin in the therapy of male osteoporosis. METHODS: Nine male patients aged 20-73 years with vertebral osteoporosis were included in this study. Patients were prescribed 100 units of salmon calcitonin injected subcutaneously three times per week over a period of three months, followed by three months without salmon calcitonin treatment. Thereafter the patients received another salmon calcitonin cycle for three months as described above. All men received calcium supplementation of 1000 mg/day throughout the study period of 12 months. Bone mineral density of the lumbar spine and at the hip was measured at the beginning and the end of the treatment period using DXA (n = 7) or QCT (n = 2). RESULTS: Baseline evaluation revealed a bone mineral density of the lumbar spine of 0.78 +/- 0.09 g/cm2 and 0.62 +/- 0.09 g/cm2 at the hip. Treatment with salmon calcitonin resulted in a significant increase of vertebral bone mineral density to 0.80 +/- 0.09 g/cm2 (p < 0.015). Femoral bone mineral density also significantly increased after salmon calcitonin therapy to 0.64 +/- 0.11 g/cm2 (p < 0.05). CONCLUSION: These results show that calcium and salmon calcitonin increase bone mineral density in male patients with osteoporosis. Calcium and calcitonin may be useful in the treatment of male osteoporosis; however, further studies are necessary before definite recommendations can be made.

[Autoimmune pancreatitis associated with rheumatoid arthritis: successful combination therapy with steroids and methotrexate]. / Autoimmunpankreatitis assoziiert mit rheumatoider Arthritis. Erfolgreiche Kombinationstherapie mit Steroiden und Methotrexat.

UNLABELLED: MEDICAL HISTORY AND CLINICAL FINDINGS: A 70-year-old female patient suffered from steatorrhea and upper abdominal discomfort for 8 weeks combined with new onset of arthralgia in both hands. Additionally she reported elevated fasting blood glucose levels. The physical examination was without pathological findings except for mild upper abdominal pressure pain. INVESTIGATIONS: Imaging studies, including MRI and ultrasound examinations showed diffuse pancreatic enlargement without peripancreatic vessel involvement. Serological examinations showed elevated Cancer Associated Antigen 19 - 9 (1289 U/ml) and hyperglobulinemia with an IgG level of 170 mg/dl. The inflammatory markers were within normal ranges other than a slightly elevated erythrocyte sedimentation rate (35mm/1 h). Subsequent pancreatic biopsy showed lymphoplasmocellular, neutrophile and eosinophile granulocyte infiltration causing damage of the acinar pancreatic cells, typical for autoimmune pancreatitis (AIP). Magnetic resonance imaging (MRI) confirmed arthritis of both hands. TREATMENT AND COURSE: Medical treatment was started with oral prednisolone (50 mg/day) for one week, tapered to 25 mg/day for another 2 weeks, followed by dose reductions of 5 mg/day every 2 weeks with a final maintenance dose of 5 mg/day for 8 months. After the first week of steroid therapy methotrexate (MTX) was started with an initial dose of 10 mg/week. Dose was raised until a final dosage of 30 mg/week. After 8 months without relapse, the maintenance therapy was reduced to 20 mg/week MTX and corticosteroids were stopped. CONCLUSION: With this treatment regimen the patient has showed complete remission of AIP and arthritis for 36 months. MTX may be successful as an initial basic treatment to reach better control of autoimmune-related extrapancreatic manifestations.

Stimulatory effects of distinct members of the bone morphogenetic protein family on ligament fibroblasts.

OBJECTIVE: To investigate effects of cartilage derived morphogenetic protein-1 and -2 (CDMP-1, CDMP-2), bone morphogenetic protein (BMP)-7 and BMP-6 on metabolism of ligament fibroblasts and their osteogenic or chondrogenic differentiation potential. METHODS: Ligament fibroblasts were obtained from 3 month old calves, plated as monolayers or micromass cultures, and incubated with or without CDMP-1, CDMP-2, BMP-7, and BMP-6. Expression of the indicated growth factors was assessed by RT-PCR and western immunoblotting. The presence of their respective type I and II receptors, and lineage related markers, was investigated in stimulated and unstimulated cells by RT-PCR and northern blotting. Biosynthesis of matrix proteoglycans was assessed by [(35)S]sulphate incorporation in monolayers. Alcian blue and toluidine blue staining was done in micromass cultures. RESULTS: CDMP-1, CDMP-2, BMP-7, and BMP-6 were detected on mRNA and on the protein level. Type I and II receptors were endogenously expressed in unstimulated ligament fibroblasts. The growth factors significantly stimulated total proteoglycan synthesis as assessed by [(35)S]sulphate incorporation. Toluidine blue staining showed cartilage-specific metachromasia in the growth factor treated micromass cultures. Transcription analysis of stimulated ligament fibroblasts demonstrated coexpression of chondrocyte markers but no up regulation of osteogenic markers. CONCLUSION: CDMP-1, CDMP-2, BMP-7, and BMP-6 and their receptors were expressed in ligament tissue. These growth factors induced matrix synthesis in fibroblasts derived from bovine ligament. The preferential expression of cartilage markers in vitro suggests that CDMP-1, CDMP-2, BMP-7, and BMP-6 have the potential to induce differentiation towards a chondrogenic phenotype in ligament fibroblasts. Thus, fibroblasts from ligaments may serve as a source for chondrogenesis and tissue repair.

Decrease of proteinuria in a patient with adult-onset Still's disease and glomerulonephritis after anti-TNFalpha therapy.

We report the case of a 41-year-old man diagnosed with Still's disease. Multiple disease-modifying anti-rheumatic drug (DMARD) therapies failed to induce disease remission or to prevent progressive joint destruction. The man presented with active arthritis and classical Still's rash accompanied by fever. Anti-tumour necrosis factor-alpha (TNFalpha) therapy was planned but during the medical check-up prior to the biological therapy, renal insufficiency with marked proteinuria (PU) was discovered. With PU of 912 mg/24 h a renal biopsy was performed and a histopathological evaluation revealed the diagnosis of a residual mesangio-proliferative immunocomplex-based glomerulonephritis (GN). After excluding contraindications, infliximab therapy was initiated and a good response of the arthritis was documented after 6 weeks. A significant decrease in PU (279 mg/24 h) was noted after the third infliximab infusion. Because of an allergic reaction during the fifth dose, the infliximab was discontinued. During the time frame without anti-TNFalpha therapy, active joint disease reoccurred and the proteinuria increased significantly. Because of the active disease entanercept therapy was initiated. The arthritis diminished and the PU was reduced markedly within 4 weeks. In the follow-up period of 12 months a good response to therapy was sustained. As described by other investigators, the joint disease showed a rapid and sustained response to anti-TNFalpha therapy. The decrease in proteinuria during biological therapy was notable. It was concluded that the significant decrease in PU in this patient was achieved by eliminating the inflammatory activity of the underlying kidney disease.

A comparative bioavailability study on two new sustained-release formulations of disodiummonofluorophosphate versus a nonsustained-release formulation in healthy volunteers.

In 12 healthy volunteers the pharmacokinetic parameters of two new sustained-release formulations of disodiummonofluorophosphate (MFP) (B and C) were compared with those of a nonsustained-release reference preparation (A). This randomized study had a single-dose, triple-cross over design and consisted of 3 trial days separated by a 1-week washout period. Serial blood samples were obtained over a period of 24 hours and 24-hour urine was collected. Serum and urine fluoride concentrations were determined using an ion-sensitive electrode (Orion Research). The results of this study showed a significant reduction of the area under the serum concentration versus time curve (AUC) for the sustained-release formulations (AUC B: 1487 +/- 354 ng/ml x hour, AUC C: 1369 +/- 384 ng/ml x hour) compared with the reference preparation (AUC A: 2374 +/- 652 ng/ml x hour) (B/A: 63%, C/A: 58%) (P < 0.001). Furthermore, the peak serum concentrations of fluoride (Cmax) for B and C (CmaxB: 166 +/- 42 ng/ml, CmaxC: 110 +/- 48 ng/ml) were significantly lower than for A (CmaxA: 380 +/- 77 ng/ml) (P < 0.001). The 24-hour urine fluoride recovery rates were 5.6 +/- 0.7 mg fluoride for A, 3.6 +/- 0.8 mg for B, and 3.2 +/- 1.1 mg for C and corresponded well to the relative fluoride bioavailability, as concluded from the serum fluoride concentration. In conclusion, the sustained-release preparations of MFP led to a decrease of fluoride bioavailability and avoided high peak serum concentrations.

[The effect of Condrosulf (sodium chondroitin sulfate) on proteoglycan synthesis by human osteoarthritic an bovine juvenile articular cartilage chondrocytes--an in vitro study]. / Der Einfluss von Condrosulf (Natriumchondroitinsulfat) auf die Proteoglykansynthese und Zellproliferation osteoarthrotischer humaner und juveniler boviner Gelenksknorpelzellen--eine In-vitro-Untersuchung.

BACKGROUND: Sodiumchondroitinsulfate, Condrosulf, is used in osteoarthritis therapy and belongs to the group of symptomatic slow-acting drugs for osteoarthritis. The aim of this study was to investigate the effects of Condrosulf on total proteoglycan synthesis and cell proliferation in human osteoarthritis and healthy juvenile bovine chondrocytes in vitro. METHODS: Chondrocytes were grown as monolayers and stimulated for 7 (human cartilage), or 4, 8 and 12 days (bovine cartilage) with different concentrations of Condrosulf (100 micrograms/ml, 500 micrograms/ml, 1000 micrograms/ml, 2500 micrograms/ml and 5000 micrograms/ml). Proteoglycan synthesis was measured by [35S]Sulfate incorporation. The cell proliferation rate was determined using a [3H]Thymidin assay. The expression of the cartilage markers aggrecan and collagen type II was assessed by Northern blot analysis. RESULTS: We show that the incubation with Condrosulf did not affect proteoglycan synthesis neither in osteoarthritis, nor in healthy chondrocytes under the present culture conditions. Cell proliferation rate was also not increased by Condrosulf stimulation. The results of the Northern blot assays demonstrated a dose-dependent down regulation of aggrecan expression on mRNA level. CONCLUSIONS: These data indicate a lack of direct anabolic effects of Condrosulf on the biosynthetic activity of cultured articular chondrocytes. The well known ease of clinical symptoms, such as pain or swelling under Condrosulf medication may be interpreted by an interaction with pro-inflammatory cytokines.

Differential expression of the protooncogene bcl-2 in normal and osteoarthritic human articular cartilage.

OBJECTIVE: To investigate the expression of bcl-2 in healthy and osteoarthritic articular cartilage at the transcriptional level and at the protein level. METHODS: bcl-2 mRNA was detected by reverse transcriptase/polymerase chain reaction. The expression of bcl-2 protein was studied using flow cytometry analysis with a monoclonal antibody against intracellular bcl-2 and by immunohistochemistry. RESULTS: mRNA for bcl-2 was detectable in chondrocytes of both healthy and osteoarthritic cartilage. bcl-2 protein was present in the chondrocytes of the middle layer of cartilage by immunohistochemical staining. In osteoarthritis (OA), chondrocytes adjacent to cartilage defects expressed a particularly high signal intensity. Flow cytometry analysis demonstrated the presence of bcl-2 protein in virtually all chondrocytes. CONCLUSION: Our results show that bcl-2 is expressed in healthy adult and osteoarthritic human cartilage. The increased staining of chondrocytes adjacent to osteoarthritic defects indicates a differential regulation of programmed cell death during the degenerative process in OA.

Comparison of serum fluoride levels after administration of monofluorophosphate-calcium carbonate or sodium fluoride: differences in peak serum concentrations.

Fluoride salts are widely used in Europe in the treatment of established osteoporosis with crush fractures for their ability to increase trabecular bone mass. However, in the United States fluorides are still regarded as an experimental drug. In a prospective, randomized study we compared the fluoride pharmacokinetics of enteric-coated sodium fluoride and disodium monofluorophosphate calcium carbonate (MFP-Ca) over the period of 76 h. Twenty subjects (12 females, 8 males), aged 35-80 years, free of gastrointestinal disorders, renal impairment, and liver disease and without prior fluoride intake entered the study. Ten subjects received NaF (11.3 mg fluoride) twice a day and the other ten MFP-Ca (13.2 mg fluoride) twice a day. During the study period of 76 h the patient's usual food intake was not changed. Serum fluoride levels were determined using an ion sensitive electrode. After intake of a single drug preparation of MFP-Ca or NaF, MFP-Ca showed a significantly shorter lag time of absorption and a significantly higher maximal serum fluoride concentration than NaF (P < 0.01). A comparison of fluoride cumulative characteristics of both drugs showed virtually identical serum fluoride levels before intake of the morning dose on all 4 study days, whereas serum fluoride concentrations measured 4 h afterwards were significantly higher for MFP-Ca than for NaF. These data provide evidence of high "peak" serum fluoride levels for MFP-Ca, whereas only small peak-to-trough fluctuations are seen for NaF.

Expression of bone morphogenetic protein 6 in healthy and osteoarthritic human articular chondrocytes and stimulation of matrix synthesis in vitro.

OBJECTIVE: To elucidate the role of bone morphogenetic protein 6 (BMP-6) in human articular cartilage, we investigated whether BMP-6 is expressed in adult human articular chondrocytes and analyzed the potential stimulatory effects of BMP-6 on these cells. In addition, we investigated whether osteoarthritic (OA) and normal cartilage chondrocytes behave differently. METHODS: Endogenous expression of the BMP-6 gene was examined by reverse transcription-polymerase chain reaction. BMP-6 protein was detected by Western immunoblotting. Chondrocytes were grown as monolayer cultures for 7 days in a chemically defined serum-free medium, in the absence or presence of recombinant BMP-6. Proteoglycan (PG) synthesis was measured by (35)S-sulfate incorporation into newly synthesized macromolecules. Cell proliferation was assessed by (3)H-thymidine incorporation. RESULTS: BMP-6 was expressed in both healthy and OA chondrocytes at the messenger RNA and protein levels. Total PG synthesis was significantly increased after BMP-6 stimulation of healthy (mean +/- SEM 191 +/- 11%; P < 0.001) and OA (150 +/- 25%; P < 0.03) chondrocyte cultures. A direct comparison between healthy and OA samples revealed no significant difference. The proliferation rates of normal and OA chondrocytes were not affected by BMP-6 treatment. CONCLUSION: BMP-6 is endogenously expressed in chondrocytes obtained from OA and normal adult human articular cartilage. Furthermore, BMP-6 has the potential to stimulate total PG synthesis in human articular chondrocytes derived from normal as well as OA joints. We conclude that the presence of BMP-6 in adult human articular cartilage indicates a functional role for this growth factor in the maintenance of joint integrity.

Chondrocyte number and proteoglycan synthesis in the aging and osteoarthritic human articular cartilage.

OBJECTIVE: To correlate the number of chondrocytes in healthy and osteoarthritic human articular cartilage with age, and to evaluate the influence of donor age on total proteoglycan synthesis. METHODS: Chondrocytes were isolated from human articular cartilage derived from hip joints with and without osteoarthritic lesions. The cell number was normalised to cartilage sample wet weight. In addition, the influence of age on chondrocyte numbers was assessed histomorphometrically. Chondrocytes were grown as monolayer cultures for seven days in a chemically defined serum-free basal medium. Total proteoglycan synthesis was measured by [(35)S]sulphate incorporation into newly synthesised macromolecules. RESULTS: Chondrocyte numbers in healthy cartilage decreased significantly with advancing age (r = -0.69, p<0.0001). In contrast to healthy specimens, chondrocyte numbers were decreased in osteoarthritic cartilage irrespective of and unrelated to age, and differed markedly, by an average of 38%, from the cell numbers found in healthy individuals (p<0.0001). Regarding synthesis of matrix macromolecules, no dependence on patients' age, either in healthy or in osteoarthritic specimens, could be observed. CONCLUSIONS: Under the experimental conditions employed, chondrocytes from healthy and osteoarthritic joints synthesised comparable amounts of cartilage macromolecules, independent of age or underlying osteoarthritic disease. Thus the decrease in chondrocyte number in aging and osteoarthritic joints could be a crucial factor in limiting tissue replenishment.

[Rheumatic diseases of the ankle joint and tarsus]. / Rheumatische Erkrankungen des Sprunggelenkes und der Fusswurzel.

Diseases of the hindfoot are associated with considerable functional impairment and therefore may hamper patients' movements during gait considerably. Because of biomechanical overload, articular structures, tendons and ligaments are prone to early degenerative changes during the course of rheumatic diseases as visible with plain film radiography, sonography (US), or magnetic resonance imaging (MRI). Findings may occur as arthritis of major joints or in the form of fibroostitis and bursitis of the os calcis. Despite the progressive course of rheumatic diseases and characteristic imaging findings, high variability of X-ray signs may occur. Plain film radiograms and high-resolution ultrasonography play a key role in imaging rheumatic diseases of the hindfoot. MRI supports imaging diagnosis in selected cases. The principal goals of diagnostic imaging are precise and reproducible documentation of morphologic abnormalities and differentiated analysis for planning proper conservative or surgical treatment.

Cartilage-derived morphogenetic protein-1 and -2 are endogenously expressed in healthy and osteoarthritic human articular chondrocytes and stimulate matrix synthesis.

OBJECTIVE: We investigated whether chondrocytes derived from osteoarthritic cartilage may lose their responsiveness to cartilage-derived morphogenetic protein-1, -2 (CDMP-1, -2) and osteogenic protein-1 (OP-1) compared with healthy cells, thus leading to an impaired maintenance of matrix integrity. DESIGN: Chondrocytes were isolated from articular cartilage from patients with and without osteoarthritic lesions. Cells were grown as monolayer cultures for 7 days in a chemically defined serum-free basal medium (BM) in the presence of recombinant CDMP-1, -2, and OP-1. Glycosaminoglycan synthesis was measured by [35S]Sulfate incorporation into newly synthesized macromolecules. Cell proliferation was investigated by [3H]Thymidine incorporation. The endogenous gene expression of CDMPs/OP-1 and their respective type I and type II receptors was examined using RT-PCR. The presence of CDMP proteins in tissue and cultured cells was detected by Western immunoblots. RESULTS: mRNAs coding for CDMPs and their respective receptors are endogenously expressed not only in healthy, but also in osteoarthritic cartilage. CDMP proteins are present in both normal and osteoarthritic articular cartilage and cultured chondrocytes. CDMP-1, CDMP-2 and OP-1 markedly increased glycosaminoglycan synthesis in both healthy (P< 0.01) and osteoarthritic (P< 0.05) human articular chondrocytes. A comparison of the glycosaminoglycan biosynthetic activity between healthy and osteoarthritic samples revealed no detectable difference, neither in stimulated nor in unstimulated cultures. [(3)H]Thymidine incorporation showed that CDMPs/OP-1 did not affect cell proliferation in vitro. CONCLUSION: CDMPs and OP-1 exert their anabolic effects on both healthy and osteoarthritic chondrocytes indicating no loss in responsiveness to these growth factors in OA. The endogenous expression of CDMPs/OP-1 and their receptors suggest an important role in cartilage homeostasis.