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Biomedical subjects

S Radke

Publications and source records attributed to S Radke.

At least 19 recordsLinked to original sources
PubMed2006

Expression of the angiomatrix and angiogenic proteins CYR61, CTGF, and VEGF in osteonecrosis of the femoral head.

Angiogenesis and bone repair are closely linked processes. VEGF, CYR61, and CTGF have been identified as signaling factors that control angiogenesis and could be important in fracture healing. The purpose of this study was to investigate the expression of these signaling factors in osteonecrosis of the femoral head. Twenty-one bone cylinders were retrieved from hips of patients with osteonecrosis of the femoral head at different ARCO stages. Immunohistochemistry for CD34, CYR61, CTGF, and VEGF expression was done on each bone cylinder representing the different regions of osteonecrosis (necrosis, fibrosis, transition zone, and edematous area). VEGF, CYR61, and CTGF were expressed in samples with osteonecrosis. Particularly VEGF and CYR61 were highly expressed in the edematous area. CYR61 was also highly expressed in the transition zone. CTGF was expressed mainly in the area of marrow fibrosis and edema. CYR61, CTGF, and VEGF are expressed to different degrees in the different repair zones of osteonecrosis. Particularly, the high expression of VEGF and CYR61 in the edematous area may represent a consequence of hypoxia and indicate a role of these proteins in the repair processes ongoing in osteonecrosis.

Adult↗
PubMed2004

Knee arthroplasty for spontaneous osteonecrosis of the knee: unicompartimental vs bicompartimental knee arthroplasty.

Spontaneous osteonecrosis of the knee (SON) is an osteonecrosis that mainly affects the medial femoral condyle. In endstage SON, knee arthroplasty is the therapy of choice. Because of the unicompartimental nature of the knee, unicondylar knee arthroplasty is considered an ideal implant for treatment of this condition. The purpose of this study was to prove that the long-term results of unicondylar implants are better than the results of bicondylar implants for the treatment of SON. All patients treated for SON between 1984 and 2000 have been recorded. Two groups were formed according to the implant used. In all patients the preoperative radiograph was analyzed according to stage and size of the osteonecrotic lesion and the osteoarthritic changes. Postoperatively, the Knee Society Score and the radiograph were recorded. Thirty-nine patients were included in this study, of which 23 patients were treated by a unicondylar implant and 16 by a bicondylar implant. On a short-term basis, unicondylar implants had better clinical results; however, on a long-term basis bicondylar implants were better. In comparison, only unicondylar implants had to be revised. Radiolucency lines were mainly observed in patients with unicondylar impants and large areas of osteonecrosis. Our long-term results suggest that patients with SON are better treated by bicondylar implants. The reasons for the higher failure rate for unicondylar implants are poor bone stock and secondary arthritic changes.

Aged↗
PubMed2004

Magnetic resonance imaging criteria of successful core decompression in avascular necrosis of the hip.

To identify imaging criteria that determine the outcome of core decompression (CD) in femoral-head avascular necrosis (AVN). Radiographs and magnetic resonance imaging (MRI) of 65 hips with early stage AVN treated by core decompression between January 1990 and December 2000 for AVN were reviewed. All hips were categorized into two groups according to the result of CD using total hip arthroplasty (THA) as an end point. Hips that had no THA at follow-up were allocated to group I; those treated with a THA were allocated to group II. CD results were calculated for each group using THA as an end point. The parameters analyzed were the presence or absence of edema associated with the double-line sign on the preoperative MRI, the type of epiphyseal scar (ES) according to Jing, and the type of necrosis according to Mitchell. On follow-up, 45 hips had no THA (group I); 20 patients had a THA (group II). Patients with a radiographic crescent sign and those with edema associated with the double-line sign progressed to THA significantly more frequently. The extent of the necrosis had less discriminatory effect between the two groups. ES and necrotic tissue types had no prognostic value. In regard to the success of CD, it is important to differentiate on MRI between a double line sign plus bone marrow edema and a double-line sign only.

Adult↗
PubMed2003

Transient bone marrow edema syndrome progressing to avascular necrosis of the hip - a case report and review of the literature.

Transient bone marrow edema syndrome (TMES) is a rare disease of unknown etiology. Diagnosis is made by exclusion. There is still controversy as to whether TMES is considered to be a reversible form of avascular necrosis (AVN), a disease entity of its own or a form of non-traumatic algodystrophy. We here describe the extremely rare occurrence of three cases of TMES that progressed to AVN.

Adult↗
PubMed2003

Epidermoid cyst mimicking monoarticular arthritis of the great toe.

Local swellings of the foot are a common presentation in rheumatological practice. In the following case report, an epidermoid cyst presenting with the typical features of monoarticular arthritis is described in a 27-year-old woman. The differential diagnosis of forefoot swelling is discussed, with particular emphasis on epidermoid cysts and monoarticular arthritis.

Adult↗
PubMed2003

Arthrodesis in the treatment of hallux rigidus.

We reviewed 34 patients (38 joints) with hallux rigidus treated from 1989 to 1999 with arthrodesis of the first metatarsophalangeal joint. Average patient age at time of surgery was 52 (24-71) years, and the mean follow-up was 54 (18-116) months. There were six superficial infections, and all arthrodeses united. There was a good functional result with a significant pain reduction. The mean postoperative American Orthopaedic Foot and Ankle Society (AOFAS) score was 53 (5-84) points.

Adult↗
PubMed2003

Annexin A1 processing is associated with caspase-dependent apoptosis in BZR cells.

Annexins are widely distributed and have been described in lung as well as in other cells and tissues. Annexin I (ANX AI) is a member of the calcium-dependent phospholipid binding protein family. Besides its anti-inflammatory function, ANX AI has been involved in several mechanisms such as the Erk repression pathway or apoptosis. To investigate the role of ANX AI on apoptosis in broncho-alveolar cells, we have constructed a plasmid containing the ANX AI full length cDNA. Transfected BZR cells displayed a higher level of both forms of ANX AI (37 and 33 kDa) as well as a decrease in cell viability (two-fold versus cells transfected with an empty vector). In order to analyse the endogenous ANX AI processing during stimulus-induced apoptosis, BZR cells were treated with a commonly used inducer, i.e. C2 ceramides. In these conditions, microscopic analysis revealed chromatin condensation in dying cells and the Bcl-2, Bcl-x(L)/Bax mRNA balance was altered. Caspase-3 is one of the key executioners of apoptosis, being responsible for the cleavage of many proteins such as the nuclear enzyme poly(ADP-ribose) polymerase (PARP). We demonstrate that caspase-3 was activated after 4 h treatment in the presence of ceramide leading to the cleavage of PARP. Dose-response experiments revealed that cell morphology and viability modifications following ceramide treatment were accompanied by an increase in endogenous ANX AI processing. Interestingly, in both ceramide and transfection experiments, the ANX AI cleaved form was enhanced whereas pre-treatment with the caspase inhibitor Z-VAD-fmk abolished ANX AI cleavage. In conclusion, this study demonstrates a complex regulatory role of caspase-dependent apoptosis where ANX AI is processed at the N-terminal region which could give susceptibility to apoptosis upon ceramide treatment.

Annexin A1↗
PubMed2003

Transient marrow edema syndrome of the hip: results after core decompression. A prospective MRI-controlled study in 22 patients.

BACKGROUND: Transient marrow edema syndrome (TMES) of the hip is a disease of acute onset and severe functional disability. There is histological evidence for an ischemic etiology of TMES of the hip. Core decompression as applied for avascular necrosis (AVN) of the hip is therefore a therapeutic alternative to conservative therapy, the latter leading only to a reduction of symptoms but never a shortening of the course of the disease. METHODS: Between January 1998 and June 2000, 22 hips with TMES were treated with core decompression in our department. TMES was diagnosed by exclusion. MRI was done preoperatively and at 6 months postoperatively. The postoperative MRI result was classified into three categories. RESULTS: After an average of 7.2 (range 1-30) days, all patients were pain-free after core decompression. In 2 patients, TMES progressed to AVN despite core decompression. All others had no signal alterations of the head of the femur on MRI after 6 months. The postoperative Harris Hip Score (HHS) in patients with TMES was on average 93.7 (range 77-95); in patients with AVN, the postoperative HHS was 47 (range 45-49). CONCLUSION: Our results demonstrate that core decompression of the hip significantly shortens the natural course of disease of TMES of the hip.

Adult↗
PubMed2003

Treatment of transient bone marrow oedema of the hip--a comparative study.

Between 1990 and 2000, we treated 43 patients with transient bone marrow oedema of the hip. Five were treated with nonsteroidal antiinflammatory drugs (NSAIDs) and limited weight bearing, and 38 by core decompression followed by limited weight bearing. At follow-up 2-10 years later, all patients were assessed by a structured interview as well as the Harris hip score (HHS) and the Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC). Both groups reached the same clinical outcome (HHS and WOMAC). Core decompression enabled a significantly faster recovery. There were no complications, but progression to avascular necrosis was seen in both groups. Core decompression induced fast pain relief, making it the preferable treatment.

Adolescent↗
PubMed2002

[The juxtaacetabular ganglion].

A juxtaarticular ganglion (JAG) is a rare tumor-like lesion of the acetabulum, causing chronic hip disability. Due to its location, a JAG is a special form of an intraosseous ganglion. There is a lack of histological criteria to differentiate a JAG from an osteoarthritic cyst. The clinical findings of a JAG are determined by its proximity to the joint gap and its extraarticular extension. In a case report the necessary diagnostics as well as the therapeutic consequences are discussed.

Acetabulum↗
PubMed2002

Detection of differentially expressed genes in particle disease using array-filter analysis.

UNLABELLED: The precise cellular mechanism of osteolysis in particle disease is still unknown. The aim of the study was to screen for new gene products in macrophages during particle contact. METHOD: In an established macrophage model THP1-cells (human monocytic cells) were differentiated under the influence of vitamin D3 and GM-CSF into macrophage-like cells (MLC). MLCs were incubated each with different concentrations of polyethylene particles, Lipopolysaccharids (LPS) and controls. Isolated RNA was transcribed into complementary radioactive 32P labeled cDNA. This probe was hybridised on an human cDNA expression array and analysed by autoradiography. To obtain a more reliable method quantifying mRNA, the reverse transcriptase polymerase chain reaction (RT-PCR) was used. RESULTS: The arrays showed an upregulation of the following genes by particles: TNF-Rezeptor 2, IL-1 Receptor Antagonist, Bone Morphogenic Protein 4 and HM 145. This was proven three times using RT-PCR and statistically significant in comparison to the controls. LPS induced the same upregulation except for HM145 whereas particles caused downregulation of this mRNA expression. CONCLUSION: Our results prove that the model of differentiated THP-1 cells treated with PE particles is a suitable system to analyse differential gene expression patterns, since the induction of the major positive control genes TNF alpha and IL1 beta were detected by this approach. BMP 4 is known as signal protein which mediates ectopic bone formation and can also be interpreted as a contra regulatory gene. HM 145 belongs to the leukocyte chemotactic peptide receptor family. HM 145 seems to be one of the first genes that is enhanced along the septical pathway but less expressed by contact with particles. Analysis of HM 145 expression might help to diagnose septic versus aseptic loosening of prosthesis.

Bone Morphogenetic Protein 4↗
PubMed2001

Correlation of power Doppler sonography with vascularity of the synovial tissue of the knee joint in patients with osteoarthritis and rheumatoid arthritis.

OBJECTIVE: To examine the significance of power Doppler sonography (PDS) in the diagnosis of synovial hypertrophy of the knee joint by verifying and comparing the PDS findings with histopathologic findings of synovial membrane vascularity. METHODS: The knee joints of 23 patients who were undergoing arthroplasty of the knee joint because of osteoarthritis or rheumatoid arthritis were examined with ultrasound before arthroplasty. The vascularity of the synovial membrane was classified semiquantitatively using PDS. A sample of synovial tissue was obtained during the arthroplasty, and the vascularity of the synovial tissue was evaluated by immunohistochemistry (factor VIII) and was graded qualitatively by a pathologist who was unaware of the PDS findings. The visual qualitative grading by the examiner was controlled by analyzing PDS images and histologic samples using a digital image evaluation system. RESULTS: The correlation between the qualitative PDS results and the qualitative grading of the vascularity by the pathologist was 0.89 by Spearman's rho (P < 0.01). The Pearson correlation coefficient between the digital analysis of the PDS images and the digital analysis of the tissue sections was 0.81 (P < 0.01). Digital image analysis and qualitative grading by the examiner had a correlation of 0.89 by Spearman's p (P < 0.01) for the PDS images. The correlation between the qualitative estimation of vascularity by the pathologist and the digital image analysis was 0.88 by Spearman's rho (P < 0.01). CONCLUSION: In the present study, PDS proved to be a reliable diagnostic method for qualitative grading of the vascularity of the synovial tissue. In clinical practice, PDS allows further differentiation of the hypertrophic synovium.

Adult↗
PubMed2001

[MRI of the shoulder. Degenerative changes and rotator cuff tears].

MRI currently offers the best imaging information for the diagnosis of subacromial pain syndrome, rotator cuff tears and osteoarthritis of the shoulder. The excellent anatomical and tissue specific imaging allows a detailed evaluation of the rotator cuff as well as the adjacent bony structures. If the cause of subacromial pain can not be determined despite extensive clinical, sonographical and radiological examination, MRI is indicated if there is a suspected pathology of the bony structures or the glenohumeral joint that could influence the further therapeutic procedures. In addition, MRI evaluation of muscular atrophy has become an important factor for determining appropriate therapy, particularly in cases of massive rotator cuff tears.

Acromion↗
PubMed2001

Transient bone marrow oedema of the foot.

We treated ten patients who on the basis of MRI were suspected to have transient bone marrow oedema. In eight cases the talus was affected, in one the cuboid and in one the navicular bone. All patients had acute onset pain at the ankle. Four were treated with core decompression and had an immediate pain relief. Six were treated conservatively and became also pain-free but with considerable delay.

Acute Disease↗
PubMed1999

Requirements of protein kinase cdelta for catalytic function. Role of glutamic acid 500 and autophosphorylation on serine 643.

Recently, we reported that, in contrast to protein kinase C (PKC)alpha and betaII, PKCdelta does not require phosphorylation of a specific threonine (Thr505) in the activation loop for catalytic competence (Stempka et al. (1997) J. Biol. Chem. 272, 6805-6811). Here, we show that the acidic residue glutamic acid 500 (Glu500) in the activation loop is important for the catalytic function of PKCdelta. A Glu500 to valine mutant shows 76 and 73% reduced kinase activity toward autophosphorylation and substrate phosphorylation, respectively. With regard to thermal stability and inhibition by the inhibitors Gö6976 and Gö6983 the mutant does not differ from the wild type, indicating that the general conformation of the molecule is not altered by the site-directed mutagenesis. Thus, Glu500 in the activation loop of PKCdelta might take over at least part of the role of the phosphate groups on Thr497 and Thr500 of PKCalpha and betaII, respectively. Accordingly, PKCdelta exhibits kinase activity and is able to autophosphorylate probably without posttranslational modification. Autophosphorylation of PKCdelta in vitro occurs on Ser643, as demonstrated by matrix-assisted laser desorption ionization mass spectrometry of tryptic peptides of autophosphorylated PKCdelta wild type and mutants. A peptide containing this site is phosphorylated also in vivo, i.e. in recombinant PKCdelta purified from baculovirus-infected insect cells. A Ser643 to alanine mutation indicates that autophosphorylation of Ser643 is not essential for the kinase activity of PKCdelta. Probably additional (auto)phosphorylation site(s) exist that have not yet been identified.

Animals↗
PubMed1991

Differential expression of epidermal growth factor-related proteins in human colorectal tumors.

Amphiregulin (AR) and cripto are proteins that are structurally related to epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha). AR is also functionally related to this family of growth regulatory molecules and is able to bind and activate the 170-kDa EGF receptor (EGFR). Human EGFR-3 (HER3)/ERBB3 is a recently identified protein related to the EGFR that is widely expressed in breast carcinomas and is a candidate receptor for EGF-like growth factors. Differential expression of these putative ligands and receptors in transformed cells suggests that they may function in an autocrine manner to regulate tumor cell growth. Specific mRNA transcripts for TGF-alpha [4.8 kilobases (kb)], AR (1.4 kb), cripto (2.2 kb), and HER3 (6.2 kb) were expressed in a majority of human colon cancer cell lines. HER3 mRNA was detected in 55% of primary or metastatic human colorectal carcinomas but in only 22% of normal colon mucosa and 32% of normal liver samples. In contrast, cripto and AR mRNA were expressed in 60-70% of primary or metastatic human colorectal cancers but in only 2-7% of normal human colonic mucosa. Immunostaining also detected AR protein in primary and metastatic colorectal tumors but not in normal colon or uninvolved liver. These findings suggest that cripto and AR may be useful markers to discriminate between normal and malignant colonic epithelium and may provide a selective growth advantage for colorectal carcinomas.

Actins↗
PubMedDate not supplied

[The role of MRI in therapy and follow-up after surgical treatment of osteochondrosis dissecans of the talus].

AIM: Our study was designed to evaluate the use of magnetic resonance imaging (MRI) in the follow-up of surgically treated osteochondrosis dissecans (OCD) of the talus. METHOD: We investigated 16 patients (18 joints) with OCD of the talus, surgically treated in our department between 1990 and 1997. All of them had preoperative MRI scans of the affected ankle. The mean follow-up was 40 months (8-82). All patients were evaluated by clinical examination, plain radiography and MRI using a standard protocol. RESULTS: The clinical Bray score improved significantly from 58 preoperative to 82 postoperative. Using a visual analogue scale we saw a significant reduction of the patients pain level post-op. In 72% of the patients the preoperative MRI was able to predict the accurate stage of the cartilage. Postoperative MRI showed no more lesion in 3, intact articular cartilage in 11, and disrupted cartilage in 4 joints. There was no correlation between clinical, plain radiographical, and MRI findings postoperative. CONCLUSION: Arthroscopy remains the golden standard in evaluating articular cartilage. Using our data, MRI is not the method of choice in the follow-up of surgically treated OCD lesions of the talus. Postoperative use of intravenous contrast media gave no additional information. Postoperative MRI should be reserved only for symptomatic patients to gather additional information about the actual state of the OCD. Afterwards a prompt arthroscopy of the symptomatic ankle should be performed.

Adolescent↗