Biomedical subjects

F Maurer

Publications and source records attributed to F Maurer.

At least 19 recordsLinked to original sources

PubMed2002

[Good long term results with a cemented straight femoral shaft prosthesis made of titanium].

A higher-than-average rate of aseptic loosening has been postulated to be associated with the combination of a titanium stem and bone cement. In this prospective follow-up study we therefore investigated our first consecutive series of 250 implantations of a cemented femoral shaft prosthesis made of titanium alloy (BiCONTACT((R)), Aesculap, Tuttlingen, Germany). Average time of follow-up evaluation was 9.7 years (range 8.7-10.3 years). At follow-up, mean patient age was 81 years; 89 patients with 93 hips have deceased and two could not be located. Follow-up rate was 98.7% for the patients still alive at time of follow-up evaluation. Five patients have been revised, two for infection and one for aseptic loosening of a varus-malaligned stem; two radiologically well-fixed stems had been revised during acetabular revision. Survival estimate showed a calculated cumulative survival rate of 97.5% after 11 years [confidence limits: 99.0% (upper) and 94.1% (lower)]. The average Harris hip score at time of follow-up was 82.25 points.Radiologically, signs of loosening could be detected in 3 stems: in one case varus malalignement deteriorated with time and in 2 cases osteolyses developed together with significant polyethylene wear. All 3 patients experienced only mild pain and revision had not been indicated so far. In conclusion, the long-term follow-up results with this cemented titanium femoral component are encouraging and are comparable to other successful cemented femoral components in primary total hip arthroplasty. No increased risk for aseptical loosening was associated to the combination of titanium and cement in this specific stem. Design parameters seem to play an important role in the development of aseptic loosening in cemented titanium stems.

Adult↗

PubMed2001

MR-guided biopsy of musculoskeletal lesions in a low-field system.

Thirty magnetic resonance (MR)-guided biopsies were obtained from 20 skeletal and 10 soft-tissue lesions in 31 patients using an open 0.2 T MR system equipped with interventional accessories. The results from aspiration (N = 3), core biopsy (N = 15), and transcortical trephine biopsy (N = 12) were evaluated for accuracy and clinical efficacy. Specimens were successfully obtained from 29 patients. Results were clinically effective in 23 patients, rated definitive in 16, nonconclusive in 9, and unspecific in 2 patients. A false diagnosis due to sampling error occurred in 2 patients, and biopsy sampling was impossible in one case. The best diagnostic yield was achieved from nontranscortical biopsies of osteolytic or soft-tissue masses. Results from transcortical biopsies were less specific due to the predominance of benign lesions. MR fluoroscopy for needle guidance was applied in 13 patients. Complete needle placement inside the magnet could be performed in 16 patients. MR-guided biopsy using an open low-field MR imager is feasible and clinically effective and will become a valuable tool in the management of musculoskeletal lesions. J. Magn. Reson. Imaging 2001;13:761-768.

Adolescent↗

PubMed2001

[Soft tissue chondromatosis of the foot: diagnosis and therapy].

Chondromas of the soft tissue are uncommon, benign tumors. They are most frequently found adjacent to periarticular tissues or tenosynovium with a predilection for the hands and feet. We report a case of a patient with a large, increasing tumor of the left foot. Because of subjective complaints and mechanical irritation the patient was scheduled for surgery. The preoperative radiological work-up showed popcorn like clusters of calcifications around the dorsum of the foot. The tumor mass was reduced using several incisions. Histology showed soft tissue chondromatosis of the foot without malignancy. Following the operative procedure, the patient was free of pain and able to wear normal shoes. This case illustrates the clinical and radiological characteristics as well as the surgical treatment of progressive soft tissue chondromatosis.

Adult↗

PubMed2001

Results of a cemented titanium alloy straight femoral shaft prosthesis after 10 years of follow-up.

Two-hundred fifty implantations of a cemented femoral stem made of titanium alloy in 239 patients were followed for 9.7 years (range 8.7-10.3 years). Eighty-nine patients with 93 hips have died and two could not be located. Five hips have been revised, two for infection, one for aseptic loosening and two during revision of the cup. Three stems showed radiological loosening but have not been revised. The average hip score was 85. The results are encouraging and comparable to other cemented femoral stems.

Adult↗

PubMed2001

Rupture of the patellar tendon: a review of 68 cases and a retrospective study of 29 ruptures comparing two methods of augmentation.

Rupture of the patellar tendon is a rare injury requiring acute repair to reestablish knee extensor continuity and to allow early motion. Different pathomechanisms have been postulated, and multiple techniques for repair have been described in the literature. Firstly, the current study reviews the epidemiology, pathomechanism, and risk factors. Secondly, we compare the outcome of two augmentation techniques after end-to-end sutures: reinforcement with either a wire cerclage or a PDS cord. In the first part of the study, the medical records of 66 patients with 68 ruptures were reviewed. For the second part, 33 patients were included who had no prior injury to the extensor mechanism of the knee and had suffered an indirect, low-velocity injury followed by immediate repair. Twenty-seven patients with 29 ruptures of the patellar tendon returned for follow-up. Follow-up averaged 8.1 years (range 1-16 years). In the follow-up group, 22 ruptures had augmentation with a wire cerclage (group A), and 7 ruptures had augmentation with a 2-mm PDS cord (group B). Follow-up evaluation consisted of a subjective questionnaire, a physical and radiographic examination, the Hospital for Special Surgery Knee Score, and the Insall-Salvati ratio. Nineteen patients underwent Cybex isokinetic strength testing of the quadriceps. Indirect, low-velocity injuries occurred most often in the 30-40 year age group, whereas complex knee traumas or knee luxations were more evenly distributed. In 10 of 46 patients with an indirect, low-velocity injury, there was a history of prior injury and illness to the extensor mechanism of the knee, compared with 1 of 22 patients with a high-velocity complex knee trauma. In the follow-up group, no patient sustained a rerupture. Two of 22 patients had an extension lag in group A compared with no extension lag in group B. Average flexion in group A was 130 degrees (SD 29 degrees) compared with 137 degrees (SD 12 degrees ) in group B. The average Hospital for Special Surgery Knee Score was 92 (SD 17) in group A and 96 (SD 12) in group B. Three patients were dissatisfied. All had radiographic signs of retropatellar osteoarthritis. In contrast, 9 of 26 patients who were satisfied with their result had radiographic signs of retropatellar osteoarthritis. A postoperative difference in the Insall-Salvati ratio did not correlate with the development of osteoarthritis. Both augmentation techniques are reliable and demostrate good intermediate to long-term results. The outcome did not show significant differences. To avoid reoperation for removal of the cerclage wire, a PDS cord can be used. The infection rate seems to be higher in the PDS group. A larger prospective study group is necessary to determine whether this phenomenon can be reproduced.

Female↗

PubMed2001

Allogeneic cancellous bone graft and a Burch-Schneider ring for acetabular reconstruction in revision hip arthroplasty.

BACKGROUND: There is an ever-increasing number of failed hip arthroplasties associated with massive deficiency of acetabular bone stock consisting of a segmental or cavitary defect. This study was undertaken to evaluate the long-term results after use of morselized cryopreserved allogeneic bone graft and an antiprotrusio cage to treat such a deficiency. METHODS: From January 1, 1988, to January 1, 1994, forty-one patients (forty-one hips) with an acetabular defect classified as type IIl or IV according to the American Academy of Orthopaedic Surgeons system were operated on with use of a Burch-Schneider ring and morselized cryopreserved allogeneic cancellous bone graft. Thirty-eight patients (thirty-eight hips) were available for clinical and radiographic follow-up examinations at an average of 7.3 years (range, 4.2 to 9.4 years) after surgery. RESULTS: All measured clinical parameters had improved significantly by the time of the follow-up examination (p < 0.0001). Radiographs confirmed that none of the thirty-eight hips had any measurable migration or displacement of the acetabular component and that osseous consolidation occurred only within the grafted area in all patients. CONCLUSION: Acetabular reconstruction with use of morselized cryopreserved allogeneic cancellous bone graft and the Burch-Schneider ring can be highly successful in managing massive acetabular deficiencies in revision hip arthroplasty.

Acetabulum↗

PubMed2000

[Treatment results after primary and secondary resection of the radial head].

Apart from comminuted fractures of the radial head the indication for resection of the radial head is discussed controversially. To evaluate our own results, the hospital notes of 113 patients treated between 1.1.1984-31.12.1994 in our clinic by posttraumatic primary or secondary radial head resection were examined retrospectively. 79 patients were controlled by clinical and radiological examination with an average follow-up of 37.8 months. We examined at 46 patients the influence of additional lesions of the elbow joint on the functional outcome. In 33 patients follow up was done with special regard to the time of resection. Poor results due to the score from Radian and Riseborough especially followed secondary radial head resection (> 14 days after trauma) and in case of additional elbow lesions. We could not observe problems of the wrist joint after radial head resection as described by other authors. According to our own experience primary resection is recommended in case of doubtful reconstruction of the radial head. In these fracture types radial head resection should not be seen as an alternative treatment because of the worse results following secondary resection.

Adolescent↗

PubMed2000

Results of an uncemented straight femoral shaft prosthesis after 9 years of follow-up.

The first consecutive 250 implantations of an uncemented, proximally anchored straight femoral shaft prosthesis (BiCONTACT) in 236 patients are included in this prospective follow-up study. Average time of follow-up evaluation was 8.9 years (range, 7.4-10.7 years). At follow-up, 27 patients had died, and 2 could not be located. Seven patients underwent revision-2 for infection, 1 for recurrent dislocation, 2 for component undersizing with rapid subsidence, and 1 for aseptic loosening of a varus-malaligned stem; 1 radiologically well-fixed stem had been revised during acetabular revision. Overall survival was 97.1% after 11 years (confidence limits, 98.7% [upper] and 93.6% [lower]). The average Harris Hip score at time of follow-up was 84.3 points. Radiologically, tiny reactive lines (<2 mm) were present in the distal zones of the femoral shaft, but no radiolucencies could be found in the proximal anchoring zone. The midterm to long-term follow-up results with the evaluated femoral component are encouraging and are comparable to those of modern techniques of cementing in primary total hip arthroplasty.

Adult↗

PubMed2000

The molecular basis for the aberrant production of plasminogen activator inhibitor type 2 in THP-1 monocytes.

Plasminogen activator inhibitor type 2 (PAI-2) is a urokinase inhibitor that is expressed primarily in monocytes. THP-1 monocytes, however. contain a unique defect in the production of PAI-2 in that the PAI-2 transcript is truncated and the expressed protein inactive (1). Here we describe the basis of this mutation in THP-1 cells. Southern blot analysis of THP-1-derived genomic DNA indicated that there were no obvious deletions in the structure of the PAI-2 gene. However, assessment of the THP-1-derived PAI-2 transcript by RT-PCR indicated that only exons seven and eight of the normal PAI-2 mRNA could be detected. Cloning of the 5' region of the PAI-2 mRNA by 5-'RACE indicated that the PAI-2 cDNA derived from THP-1 cells is approximately 1329 bp long and contains 180 bp of sequence derived from intron 5. followed by sequences corresponding to exons seven and eight of the normal PAI-2 mRNA. The presence of the intron five fragment in endogenous THP-1 derived PAI-2 mRNA was confirmed by Northern blotting. The absence of any wild-type PAI-2 mRNA in these cells suggests that one copy of the PAI-2 allele has been deleted. The remaining allele producing the truncated mRNA appears to have undergone a translocation event and contains a mutation that has disrupted the splicing of the PAI-2 primary transcript.

Cloning, Molecular↗

PubMed1999

An AU-rich sequence in the 3'-UTR of plasminogen activator inhibitor type 2 (PAI-2) mRNA promotes PAI-2 mRNA decay and provides a binding site for nuclear HuR.

The plasminogen activator inhibitor type 2 (PAI-2) gene is regulated by transcriptional and post-transcriptional processes. We have previously shown that insertion of the 3'-untranslated region (3'-UTR) of PAI-2 mRNA into the 3'-UTR of a beta-globin reporter mRNA reduces constitutive beta-globin mRNA expression and that this requires, at least in part, an AU-rich motif. Here we have directly assessed the role of this motif in PAI-2 mRNA stability using both chimeric and non-chimeric reporter systems. We first show that the full-length PAI-2 mRNA is indeed unstable with a half-life of 1 h. Using the c-fos promoter-driven human growth hormone (HGH) mRNA as a reporter, we demonstrate that the 580 nt 3'-UTR of PAI-2 accelerates chimeric HGH mRNA decay in a process which is dependent on the intact AU-rich sequence. Furthermore, disruption of this motif within a constitutively expressed PAI-2 cDNA produces a 2.5- and 2. 7-fold increase in PAI-2 mRNA and protein levels in HT-1080 cells, respectively. RNA electrophoretic mobility shift and supershift assays indicate that this motif provides a specific binding site for cellular proteins that include nuclear HuR. Taken together, these data show that a correlation exists between the binding of HuR to the AU-rich motif in vitro and the destabilizing properties conferred by this sequence in vivo.

3' Untranslated Regions↗

PubMed1999

[Spontaneous healing of a juvenile bone cyst of the tibia after pathological fracture].

Up to the present only few cases of spontaneous healing of juvenile bone cysts after pathological fractures were published. Most authors will not accept the possibility of a "healing fracture" in bone cysts because of missing documentation. In our clinic we could observe spontaneous healing of a juvenile bone cyst of the tibia after a pathological fracture in a ten-year old boy. Therefore healing of bone cysts after fracture is proven. On the other hand healing of bone cysts following conservative treatment after a fracture is not sure. Conservative treatment depends on the localization and type of the fracture. We recommend nonoperative treatment of first pathological fractures in small-sized bone cysts. This kind of treatment can be especially advised for young patients up to the tenth year because there are only few complications in fracture healing and a relatively high recurrence rate following operative treatment. In case of a refracture there are better conditions for fracture healing after surgery.

Bone Cysts↗

PubMed1999

Phase II study of oral trofosfamide as palliative therapy in pretreated patients with metastatic soft-tissue sarcoma.

This phase II study investigated the activity of continuously administered oral trofosfamide in chemotherapy-pretreated patients with metastatic soft-tissue sarcoma (STS). Trosfosfamide is an oxazaphosphorine with ifosfamide as the predominant metabolite. Eighteen patients with a median age of 60 years were treated with trofosfamide given as continuous oral treatment. Starting dose was 300 mg/day for 7 days and subsequently 150 mg/day. All patients had previously received at least one chemotherapy regimen including doxorubicin and ifosfamide. Three patients achieved partial responses (18%) and nine a disease stabilization (53%) for an overall response rate of 18% (95% CI: 0.5-35%). Median progression-free interval was 4 months (0-17 months) and median overall survival was 10 months (4-39+) months. Toxicity was generally mild. Only one WHO grade III nausea, but no other non-hematologic WHO grade III/IV toxicity occurred. Leukopenia WHO grade III/IV was observed in four patients (22%). No thrombocytopenia <50,000/microl and no neutropenic infection was seen. Continuously administered oral trofosfamide is a well-tolerated palliative treatment in anthracycline/oxazaphosphorin-pretreated patients with advanced STS achieving responses and/or disease stabilization in up to 70% of patients.

Administration, Oral↗

PubMed1998

Transcriptional regulation of the tissue-type plasminogen-activator gene in human endothelial cells: identification of nuclear factors that recognise functional elements in the tissue-type plasminogen-activator gene promoter.

The gene encoding human tissue-type plasminogen activator (t-PA) is regulated in a cell-type-specific manner. Previous studies in non-endothelial cells have indicated that basal and phorbol ester mediated induction is controlled by a cAMP response element (CRE) referred to as the tPACRE, and an activating protein 2 (AP-2)-like site. The classification of the AP-2-like site was assigned on the basis of its sequence homology, but has been shown in some cell systems to be recognised by promoter-specific transcription factor-1 (Sp-1). Here, we have investigated the transcriptional regulation of the t-PA gene in endothelial cells and addressed the functional roles of the tPACRE and the Sp-1/AP-2-like sites. 5'-RACE experiments indicate that the t-PA gene uses two transcription initiation sites in these cells with the downstream site being preferred. Functional analyses of the t-PA promoter using reporter-gene constructs transfected into C11STH endothelial cells demonstrate that the first 410 bp of the t-PA promoter confers an increase in reporter-gene activity on treatment with 4beta-phorbol 12-myristate 13-acetate (PMA). Mutagenesis of either the tPACRE or the Sp-1/AP-2 site weakens both basal and inducible expression, while disruption of both sites renders the promoter completely unresponsive. Using supershift assays, we identify the predominant tPACRE-binding proteins in nuclear extracts prepared from both C11STH cells and primary umbilical vein endothelial cells (HUVECs) as activating transcription factor 2, CREB (cAMP-responsive-element-binding protein), CREM (cAMP response element modulator) and c-jun. Treatment of cells with PMA results in a selective recruitment of jun-D to the tPACRE, while Sp-1 was identified as the major transcription factor that recognises the AP-2-like site. Based on this data and previous reports, we have reassigned this as a Sp-1-binding site. Finally, the identification of specific endothelial-derived t-PACRE-binding proteins suggests an integral role for these factors in the regulation of t-PA gene expression in human endothelial cells.

Base Sequence↗

PubMed1998

[Injuries in sledding].

Tobogganing is a very popular outdoor winter recreational activity. In order to elucidate the patterns of injuries associated with tobogganing all patients with an injury caused by falls from or collisions while on or being hit by a sled were sampled prospectively between the period of November 1996 and March 1997. 50 patients were included in this study, aged from 7 to 69 years (mean 25.5 years). Of these, 14 (= 28%) patients required admission to hospital lasting from 1 to 31 days (mean 13.5 days), 11 (22%) needed an operation. Over all we could register 55 injuries; the lower extremity was the region most commonly injured (63.6%), followed by upper extremity with 21.8%. The most common injury was the sprain of the knee. The most severe injuries could be found at the lower limb and at the vertebral column, including four fractures of the lower leg and 8 ankle-joint fractures as well as two fractures of the lumbar spine. The most common single procedure was the open reduction and internal fixation of a fibular fracture. In 48.6% of the cases the riders struck an object (tree, wall, post), while 32.4% fell from the toboggan caused by environmental conditions such as a bump or a ditch. The most important risk factor was an unadjusted speed referred to the environmental circumstances. Preventive strategies include tobogganing in adequate environmental conditions with no trees, no post or other stationary objects that could result in a collision. Speed should be adapted to the slope conditions.

Acceleration↗

PubMed1997

[Rehabilitation following hip fractures].

In the rehabilitation of patients with acetabular fractures, we try to achieve anatomical reconstruction of the joint as well as unlimited mobility. This is important for the patient's reintegration at work and in social life. These aims can only be reached with joint effort of the patient him/herself and all the different specialists concerned with the treatment. Functional physiotherapy should start as early as possible after trauma. Prophylaxis of joint stiffness, thrombosis, pneumonia and soft-tissue ulcers due to immobilization are not only important in the beginning. The restoration of circulation and resorption in the affected tissues, in addition to creation of global sensorimotor motion patterns, are the main aspects of this therapy. Definite long-term success should be ensured by concomitant ergotherapy and well-timed measures for the patient to regain his/her occupational abilities.

Acetabulum↗

PubMed1997

A peer education model for teaching breast self-examination to undergraduate college women.

The incidence of breast cancer in women continues to rise, and there is no known cause or prevention. Additionally, > 70% of all diagnosed breast cancer has no known risk factor involved. Early detection is mandatory for survival from this disease, but only three imperfect methods are available: mammography, clinical examination, and breast self-examination (BSE). One-third of all breast cancer cases occur in women under the age of 50 years, and this is a period when mammography is ineffective and clinical examination is infrequent. Consequently, BSE is highly significant for this age group. However, women do not perform BSE on a consistent monthly basis. The significant developmental characteristic of late adolescence and young adulthood is the formation of a personal identity. This age group is also heavily influenced by their peers. Therefore, a BSE program that incorporates peer education and elements essential to positive identity formation may be an effective means to establishing BSE as a normal health routine in young women.

Adolescent↗

PubMed1997

[Hip dislocations and hip fractures--acetabular fractures. Indication, technique and results of conservative treatment].

Despite the great number of publications during the last 10 years concerning the indication, technique and results of operative treatment of acetabular fractures, conservative treatment still has an important role when considering the therapeutic possibilities. Because of the modern techniques of radiological imaging and improvement of diagnostic facilities, a more defined indication for treatment becomes possible. Conventional X-rays, completed by special projections like the Ala and Obturator view, and a CT scan allow determination of the fracture type (the Letournel/Judet classification or the AO classification). The most suitable treatment can then be adapted to the individual circumstances of the patient, i.e., age, general condition and overall severity of traumatic impairment. Determination of the intact part of the weight-bearing dome is important in selecting the most adequate therapeutic procedure. The larger the intact roof arc, the better the prognosis. Together with the X-ray controls following axial and facultative lateral extensions, the indication for conservative treatment can be confirmed. Early active motion of the injured limb, followed by walking exercises with partial weight-bearing, are important aspects of nonoperative treatment. Conservative treatment is recommended in non-displaced fractures or in fractures with little displacement, transverse fractures of the lower region or severely comminuted acetabular fractures with no possibility of reconstruction. Our clinical and radiological follow-up of 97 patients with acetabular fractures from the years 1981-1990 showed that the majority were treated conservatively (approx. 70%). The functional result after an average observation period of more than 70 months was good or excellent (based on the Merle d'Aubigné score). We feel it is important to look at operative and conservative treatment of acetabular fractures as two complementary non-competitive therapeutic methods. The choice of treatment should be based on an exact diagnosis considering fracture type, the individual circumstances of the patient, and application of the necessary diagnostic facilities. Conservative treatment can lead to excellent long-term results.

Acetabulum↗

PubMed1996

Plasminogen activator inhibitor type 2 gene induction by tumor necrosis factor and phorbol ester involves transcriptional and post-transcriptional events. Identification of a functional nonameric AU-rich motif in the 3'-untranslated region.

Plasminogen activator inhibitor type 2 (PAI-2) mRNA and antigen levels are synergistically induced in HT-1080 fibrosarcoma cells when treated with a combination of tumor necrosis factor (TNF) and phorbol 12-myristate 13-acetate (PMA). Here we demonstrate that this effect is not fully reflected at the level of gene transcription, suggesting a contribution of post-transcriptional events in this induction. Insertion of the 3'-untranslated region (3'-UTR) of PAI-2 mRNA into the 3'-UTR of a rabbit beta-globin reporter gene reduces beta-globin-PAI-2 chimeric mRNA expression in stably transfected cells. The region within the PAI-2 3'-UTR responsible for this effect is located within the 368-nucleotide sequence preceding the poly(A) tail, a segment that includes a nonameric UUAUUUAUU motif. Mutagenesis of this element abolishes the PAI-2 3'-UTR destabilizing effect, revealing a functional role for this motif. TNF and PMA co-treatment of transfected cells increases beta-globin-PAI-2 chimeric mRNA expression 3-4-fold, indicating that the inherently unstable 3'-UTR of PAI-2 mRNA can become stabilized in response to TNF and PMA. Our results indicate that induction of PAI-2 gene expression by TNF and PMA involves both direct transcription as well as mRNA stabilization, the latter involving an AU-rich nonameric motif in the 3'-UTR.

Animals↗