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W Mohr

Publications and source records attributed to W Mohr.

At least 19 recordsLinked to original sources
PubMed2004

Difference in metallic wear distribution released from commercially pure titanium compared with stainless steel plates.

INTRODUCTION: Stainless steel and commercially pure titanium are widely used materials in orthopedic implants. However, it is still being controversially discussed whether there are significant differences in tissue reaction and metallic release, which should result in a recommendation for preferred use in clinical practice. MATERIALS AND METHODS: A comparative study was performed using 14 stainless steel and 8 commercially pure titanium plates retrieved after a 12-month implantation period. To avoid contamination of the tissue with the elements under investigation, surgical instruments made of zirconium dioxide were used. The tissue samples were analyzed histologically and by inductively coupled plasma atomic emission spectrometry (ICP-AES) for accumulation of the metals Fe, Cr, Mo, Ni, and Ti in the local tissues. Implant corrosion was determined by the use of scanning electron microscopy (SEM). RESULTS: With grades 2 or higher in 9 implants, steel plates revealed a higher extent of corrosion in the SEM compared with titanium, where only one implant showed corrosion grade 2. Metal uptake of all measured ions (Fe, Cr, Mo, Ni) was significantly increased after stainless steel implantation, whereas titanium revealed only high concentrations for Ti. For the two implant materials, a different distribution of the accumulated metals was found by histological examination. Whereas specimens after steel implantation revealed a diffuse siderosis of connective tissue cells, those after titanium exhibited occasionally a focal siderosis due to implantation-associated bleeding. Neither titanium- nor stainless steel-loaded tissues revealed any signs of foreign-body reaction. CONCLUSION: We conclude from the increased release of toxic, allergic, and potentially carcinogenic ions adjacent to stainless steel that commercially pure Ti should be treated as the preferred material for osteosyntheses if a removal of the implant is not intended. However, neither material provoked a foreign-body reaction in the local tissues, thus cpTi cannot be recommend as the 'golden standard' for osteosynthesis material in general.

Adipose Tissue↗
PubMed2004

[Unusual "lipid cysts" in the acetabular labrum of patients with hip joint osteoarthrosis].

Diagnostic pathological examination of surgical specimens from patients with hip joint osteoarthrosis occasionally exhibits as yet undescribed pseudocysts consisting of folded granular membranes in necrotic or chondroid tissues. When stained with Sudan red, the content of these cysts indicates the presence of lipid substances. The presence of S100 protein-positive cells with intracytoplasmic fat vacuoles as well as such cells in the walls indicate that they develop from fat inclusions occurring in the chondroid cells of the labrum. Two different wall structures were detected by electron microscopy. The first type exhibited small walls of a granular material similar to the endoplasmic reticulum that surrounds intracytoplasmic fat globules. The second type consisted of broad layers of very tiny granules indicating a more advanced stage of the development of these cysts. The reason for the occurrence of these "chondrocytogenic lipid cysts" remains unknown-it may be assumed that they are due to mechanical labrum destruction that occurs in osteoarthrosis.

Aged↗
PubMed2004

[Evaluation of percutaneous vertebroplasty in osteoporotic vertebral fractures using a combination of CT fluoroscopy and conventional lateral fluoroscopy].

PURPOSE: Evaluation of vertebroplasty using a combination of CT-fluoroscopy and conventional lateral fluoroscopy in patients with osteoporotic vertebral fractures. MATERIALS AND METHODS: Fifty-eight patients (23male, 35 women, age 69.7 +/- 10.2 years) with painful osteoporotic vertebral fractures were treated with vertebroplasty in conscious sedation and local anesthesia. Spiral-CT with sagittal reconstructions of the respective vertebral bodies was used for classification of the fracture. The cannula was placed under CT-guidance in the ventral third of the respective vertebral bodies and cement instilled under CT fluoroscopy and lateral fluoroscopy. When cement migrated towards the vertebral canal, the injection was immediately stopped for 30 - 60 seconds. After polymerization in this location, the injection was continued until sufficient filling of the vertebra. Results were documented by spiral CT with sagittal reconstructions. RESULTS: A total of 123 vertebral bodies were treated, comprising 39 thoracic and 84 lumbar vertebral bodies, with a mean of 2.1 +/- 1.3 (range 1 to 6) vertebral bodies in each patient and a maximum of 3 vertebral bodies per session. All interventions were successfully completed in conscious sedation and local anesthesia. A mean volume of 5.9 +/- 0.6 ml (range 2 to 14 ml) cement was applied for each vertebra, with 79.7 % of procedures performed using a unilateral access. To achieve a sufficient cement deposit, a bilateral access was used in 20.3 %. The dorsal wall of the vertebra was included in 23.6 % of the fractures. In one case, cement migration into the spinal canal was detected, reducing the diameter of the canal by 30 %. In two other cases, cement leakage was seen at the puncture site of the vertebra (one intercostotransversally in the 10 (th) thoracic vertebra and one dorsolaterally in the 1 (st) lumbar vertebra) with retrograde cement migration through the neuroforamen into the epidural space. In one of these cases, the cannulation of the vertebra had been changed before cement application resulting in a hole in the dorsolateral vertebral wall. However, all patients were discharged without evidence of neurologic complications. Multiplanar reconstructions of CT scans were used for the detection of extraosseous cement leaks: The incidence of extraosseous cement leaks was 4.1 % in epidural veins, 6.5 % in paravertebral vessels (6 veins, 2 arteries), and 17.9 and 11.4 %, respectively, for upper or lower end plates. At discharge, 25 patients (43.1 %) were free of pain and 28 (48.3 %) significantly improved with a considerable reduction of analgetic drugs. Significant complaints persisted in 5 patients (8.6 %) with concomitant degenerative disease in four and vasculitis in one case. CONCLUSION: Percutaneous vertebroplasty is effective for stabilization and pain management of osteoporotic vertebral fractures. The procedure can be safely performed in conscious sedation and local anesthesia. Compared to conventional fluoroscopy alone, CT fluoroscopy provides an excellent additional monitoring of the procedure and probably contributes to the safety of the procedure.

Adult↗
PubMed2003

[Calcifications in temporal arteries -- their morphogenesis in comparison to physiological osteogenesis].

OBJECTIVE: Vascular calcification, traditionally regarded as a dystrophic process, has recently been interpreted as a bone-like biologically regulated phenomenon. Because temporal arteries which also contain calcifications are easily available from biopsies of older individuals with suspected giant cell arteritis, we studied the morphogenesis of this calcification in comparison with the development of fetal bone. MATERIAL AND METHODS: Formaldehyde fixed arteries were processed in paraffin sections and investigated by light-, transmission-, and scanning electron microscopy. The atomic composition of the calcifications was estimated by X-ray microanalysis. Fetal bone, also fixed with formaldehyde, was investigated using identical methods. RESULTS: Early calcifications are often present as focal or diffuse granular mediacalcinosis. With increasing age, calcified granules appear in association with the internal elastic membranes and progress to sheet-like calcifications. Ultrastructurally calcospherites, not rarely exhibiting the Liesegang phenomenon, are the hallmark of early calcifications. In advanced sheet-like calcification calcospherites could be detected as components of the calcified lumps. Calcospherites also appear in endochondral calcification, but are absent in calcified osteoid. The ultrastructure of calcospherites in provisional endochondral ossification differs from that in vascular calcification. Instead of corpuscles as with the Liesegang phenomenon, radial clusters of needle-like crystals resembling apatite are present. While calcospherites of the tunica media often contain a high amount of magnesium, calcified sheets as well as bone exhibited in contrast a low magnesium content. CONCLUSIONS: It is concluded that, comparable to granular mediacalcinosis of the aorta, development of calcified arteriosclerotic plaques, and Mönckeberg's disease, calcification of small muscular temporal arteries is also initially a calcospherite-dependent process. It is generally accepted that these calcified corpuscles represent remnants of calcified necrotic or apoptotic cells. In the phase of confluence with the appearance of sheet-like calcification, a low bone-like magnesium content that differs from the high amount in the isolated medial calcospherites was measured. This finding, together with the observation that calcified sheets contain calcospherites, supports the hypothesis that vascular calcification in general is different from bone formation and has to be regarded as a biphasic process initiated by the appearance of calcospherites and followed by a secondary calcifying phase with the formation of bone-like apatite that leads to rock hard lumps of calcified vessels.

Adult↗
PubMed2003

[Polymorphonuclear granulocytes in rheumatic tissue destruction VIII. Considerations on the inflammatory cartilage destruction in chronic arthritides in comparison with liver injuries by PMN's].

Inflammatory cartilage destruction in chronic arthritides is usually regarded as the process owing to chondrocytic chondrolysis or ingrowth of pannus tissue. Besides these two mechanisms a third one-cartilage degradation directly mediated by polymorphonuclear granulocytes (PMN's) of the synovial fluid-seems to be underestimated. There is growing evidence that PMN's are involved in several non-bacterial organ destructions (e.g., alcoholic hepatitis); thus, two case reports are presented demonstrating cartilage destruction by PMN's via the synovial fluid. It is shown by light and electron microscopy that in florid rheumatoid arthritis, PMN's from the inflamed synovial fluid can gain access to the cartilaginous surface. The adherence of PMN's to the superficial matrix, eventually mediated by immunocomplexes, may activate these cells with the subsequent secretion of destructive enzymes as well as reactive oxygen species. Cartilage degradation may be the consequence. From the morphological findings it is deduced that this mechanism may have important implications for inflammatory cartilage loss.

Aged↗
PubMed2002

[Do polyvinylpyrrolidone (PVP) deposits still occur in internal organs at the turn of the millennium? Observations on three patients from the former USSR].

PVP had been used as a plasma expander following the end of world war II up to relatively recently but after its intracellular storage became known, it was withdrawn from use. Nevertheless, it was used as a retarding agent for subcutaneous and intramuscular administration of drugs until the 1980s and as a consequence pseudotumors have been observed. Three patients from the former USSR are described with PVP storage in the gastric and duodenal mucosa as well as in lymph nodes. The reason for the administration in these patients and the substances applied remain obscure. It is known that PVP infusions are still performed in Taiwan and that it was also injected intraarticularly as an artificial joint lubricant in Russia in the early 1990s. Because cells with intracytoplasmic deposits of PVP can be misdiagnosed as tumor cells and for reasons of general health - "la maladie polyvinylique" [1] may develop - it is still necessary to retain knowledge of the histology of cellular PVP storage.

Adult↗
PubMed2002

[Morphogenesis of media calcinosis in Mönckeberg disease. Light microscopy, scanning electron microscopy and roentgen microanalysis findings].

OBJECTIVE: In contrast to granular mediacalcinosis of the aorta, Mönckeberg's disease is characterized by the occurrence of sheet-like calcification. It is usually said that the pathogenesis of this calcification is unknown. MATERIAL AND METHODS: To obtain some insight into the mechanism leading to this calcification, we performed light microscopic, scanning electron microscopic and X-ray microanalysis investigations on femoral arteries from autopsies. RESULTS: By light microscopy preferentially sheet-like calcifications of different size appeared. In the alizarin red S stain in the neighborhood of these compact structures calcified globules were observed. By SEM in the neighborhood of the compact areas calcified granules were found; the compact structures themselves consisted of granules sticking one onto the other. X-ray microanalysis exhibited high contents of calcium and phosphorus in the compact calcifications; they also showed a minor content of magnesium. Isolated granules inside the compact calcifications showed a nearly identical composition, while granules outside in the surrounding media consisted preferentially from calcium and phosphorus, but they exhibited a slight higher magnesium content. CONCLUSIONS: It is concluded that Mönckeberg's media calcification is due to dystrophic calcification. Calcified matrix vesicles from necrotic cells, as it is assumed for the pathogenesis of the calcification of arteriosclerotic plaques (31), are interpreted as precursors of the solid calcifications which may develop by confluence and sticking one onto the other of calcified globules.

Aged↗
PubMed2002

[Does arteriosclerotic calcinosis of vessel walls imitate osteogenesis? Pathomorphological studies of arteriosclerotic plaque].

OBJECTIVE: For it is supposed that calcification of arteriosclerotic plaques imitates osteogenesis, it was studied whether the morphology of different stages of calcification supports such an assumption. MATERIAL AND METHODS: Investigations were performed on one operation specimen of a dissecting aneurysm of the aorta and five human autopsy aortas. From different arteriosclerotic plaques, paraffin sections without and after EDTA-decalcification were prepared. Light microscopic, scanning (SEM) and transmission electron microscopic (TEM) investigations as well as X-ray microanalysis were performed. RESULTS: By light microscopy, it became obvious that the intensity of calcification of arteriosclerotic plaques is not reflected by the conventional H&E stain--the real amount of calcium-phosphorus deposits becomes only evident by using a special stain, such as the alizarin red S reaction. In the SEM, arteriosclerotic plaques with granular calcification were characterized by accumulations of isolated calcified globules often reflecting the structure of necrotic cells. TEM exhibited even accumulations of calcified bodies corresponding to the shape of cells; cell remnants were present in the neighborhood. X-ray microanalysis of the granules detected calcium and phosphorus and a relative high content of magnesium, reflecting the composition of calcospherites in granular media calcification (71). By SEM, solid calcifications exhibited associations of calcified bodies resembling those of the isolated granules in early calcification but with one stuck onto the other. X-ray microanalysis revealed that these deposits are characterized by high amounts of calcium and phosphorus and a minor component of magnesium in comparison to the isolated granules. CONCLUSIONS: From the investigations it is concluded that calcification of arteriosclerotic plaques imitates the process of granular media calcification which is assumed as "dystrophic" calcification of fragments of necrotic cells. The hypothesis of a "regulated" calcification as it occurs in cartilage or bone cannot be supported for the development of the calcified plaques; however, it cannot be excluded that proteins that are associated with osteogenesis participate in the transition of calcification to ossification in the vessel wall.

Aortic Dissection↗
PubMed2001

5,6-carboxyfluorescein diacetate succinimidyl ester-labeled apoptotic and necrotic as well as detergent-treated cells can be traced in composite cell samples.

Detection of dividing cells by staining with 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) has been widely used in flow-cytometric protocols. We analyzed the fate of CFSE in cells undergoing apoptotic or necrotic cell death, respectively. Peripheral blood mononuclear cells (PBMC) were stained with CFSE. Apoptosis was induced by UVB irradiation and necrosis by incubation at 56 degrees C for 30 min. In some experiments, labeled cells were permeabilized with detergent and CFSE association with nuclei was assessed. We observed that (i) CFSE remains stably detectable in apoptotic and necrotic cells; (ii) CFSE remains stably associated with the nuclei of cells even after their lysis by detergent; (iii) CFSE labeling does not interfere with the induction of cell death; and (iv) CFSE is not transferred from stained dying cells to unstained neighboring counterparts. We conclude that, in addition to tracking viable cells, CFSE can be used to trace dying cells in composite samples. We demonstrated that CFSE labeling does not influence the induction and the execution of apoptosis or necrosis.

Apoptosis↗
PubMed2001

[Cerebral tuberculosis in a patient with Sharp's syndrome].

HISTORY AND ADMISSION DIAGNOSIS: A 57-year-old female patient with fever and impaired consciousness was admitted to the department of neurology after her first epileptic seizure. She had a 9-year history of mixed connective tissue disease (MCTD, Sharp's syndrome) predominantly presenting with pulmonary symptoms and destructive arthritis. Endoprothetic surgery had to be performed several times and she was given long-term immunosuppressive therapy. INVESTIGATIONS: Cerebrospinal fluid analysis showed pleocytosis (59/mm3), high protein concentration (2540 mg/l) and low glucose level (31 mg/dl) compared to blood glucose level (122 mg/dl) the indicating possible tuberculous meningoencephalitis. DIAGNOSIS, TREATMENT AND COURSE: Tuberculostatic therapy was initiated, but despite extensive testing Mycobacterium tuberculosis could initially not be detected by microscopy, culture or amplification techniques (TMA; transcription mediated amplification). Clinical response to antituberculous therapy was poor and the patient developed cerebral ischaemia and hydrocephalus. Because of earlier histological findings from the synovialectomy showing epitheloid cell granuloma a knee joint specimen from a wound drainage was tested and extracerebral tuberculosis was finally confirmed by mycobacterial culture so that tuberculosis as the reason for the meningoencephalitis became highly probable. Despite slight improvements the patient still had hemiparesis and lethargy as neurological sequalae at the end of therapy. CONCLUSION: The case demonstrates the difficulties in the diagnosis of tuberculosis in patients with signs and symptoms similar for those caused by other multisystemic diseases. When tuberculous meningitis is considered, therapy should be initiated even in cases with negative microbiological tests because of severe consequences when treatment is delayed.

Brain Ischemia↗
PubMed2001

[Association of silver granules with elastic fibers in amalgam reaction of mouth mucosa].

OBJECTIVE: Discoloration of the oral mucosa due to amalgam may appear histologically merely as brown pigmentation of the fibrous extracellular matrix. It was the aim of these investigations to identify the fibrous component that contains silver granules. METHODS: Biopsy specimens from seven patients with clinically diagnosed amalgam tattoos were investigated by light and electron microscopy as well as by X-ray microanalysis. RESULTS: Light microscopy revealed small brown discolored fibers in all specimens; in sections stained with Weigert's resorcinfuchsin, they appeared dark violet. Scanning electron microscopy revealed metallic granules associated with thin fibers; by X-ray microanalysis, they exhibited preferentially peaks for silver and sulfur. Transmission electron microscopy detected only electron-dense particles in elastic fibers. CONCLUSIONS: With the different morphological methods, silver granules of amalgam tattoos were exclusively detected within elastic fibers. This result indicates that granular brown discoloration of the matrix fibrils is due to silver impregnation of elastic fibers. Therefore, the histopathological diagnosis of amalgam tattoo is possible even in the absence of larger amalgam particles with black appearance.

Biopsy↗
PubMed2001

[Granular media calcinosis of the aorta. Structural findings, historical review and pathogenetic significance].

Granular mediacalcinosis of the aorta seems to be a forgotten phenomenon that had been intensively investigated at the beginning of the past century. Without knowledge of this older literature we were, first of all, astonished to find in histological sections from aortic aneurysms, appearing "normal" in the H&E stain, severe calcifications of the media in von Kóssa and Alizarin red S stained sections. Therefore, 24 operation specimens of aneurysms were investigated with several morphological methods. In all cases, light microscopy exhibited granular medial calcification with a slight increase of the severity in specimens from older patients. Scanning electron microscopy on paraffin sections revealed calcified globules with diameters of about 1 micron localized between the elastic laminae. By transmission electron microscopy these calcospherites occupied the space between the elastic laminae. X-ray microanalysis exhibited high amounts of calcium and phosphorus and a smaller amount of magnesium. This atomic composition supports the findings of Reid and Andersen (69) indicating that these calcifications are due to the deposition of whitlockite. These morphological findings are supplemented by a review of the older literature. The biological significance of this calcification remains unknown. On the one hand, it may be responsible for the increasing stiffness of the aorta in older age groups--and, on the other hand, a pathogenetic role for the development of dissecting aneurysms cannot be excluded. This may be supported by the effect of beta-aminopropionitril in lathyric rats with destruction of the interlaminar fibers, described by Nakashima and Sueishi (65): it seems possible that a focal increased calcification in the human aorta may disturb the connection between the elastic laminae, thus, facilitating their separation.

Adult↗
PubMed2001

[Juvenile hyaline fibromatosis (JHF)].

The juvenile hyaline fibromatosis (JHF) is a rare tumorous autosomal recessive disease of the connective tissue. The etiopathogenesis of the disease is unknown. Typical diagnostic criteria are multiple hyaline subcutaneous fibroma, filamentous tumors of the skin, gingival hypertrophy, muscle contractures of the extremities and multiple osteolytic bone destructions. Involvement of visceral organs is not described. Mental development and life expectancy are normal. Until today, no causal treatment of the JHF exists. Surgical excision of the dermal tumors is indicated for functional and aesthetic improvement. Complete excision should be executed in the early phase of their development. This has shown the best functional and aesthetic results, especially in facial areas. The progress of the disease is individual. Due to frequent recurrencies, repeated resections and revisions may be necessary. Interdisciplinal counseling and therapy, particularly physiotherapy, may partially improve the state of function.

Child, Preschool↗
PubMed2001

[Long-term outcome of Swanson prosthesis management of the rheumatic wrist joint].

Silicone-wrist arthroplasty has dominated reconstructive surgery of the rheumatoid wrist for a long time. Silicone interposition wrist arthroplasty yielded good clinical results in short and midterm studies. The durability and longevity of the prosthesis however is limited and progressive X-ray deterioration and silicone synovialitis are the main shortcomings. We present the ten-year follow-up results of 102 rheumatoid wrists operated between 1984 and 1992. 72 patients with 82 wrist arthroplasties were clinically and radiologically examined. The mean age at operation was 56.9 years. The average onset of R.A. was 16.1 years. Each wrist was rated on a 100-point scale, with points based on wrist balance, range of motion, pain relief and extensor strength. The postoperative Clayton score averaged 69.4 points. Including revision cases, 51% of the Swanson implants were rated good or excellent, 16% fair, and 33% were judged poor because of pain or prosthesis breakage. Patient satisfaction and pain relief were achieved in 68.2%. Active motion with unrevised implants was 21 degrees extension and 31 degrees flexion. We noticed a moderate increase (7 degrees) for ulnar-radial deviation. There was a progressive deterioration in the radiographic appearance. Implant fracture occurred in 31% of the patients. Subsidence of the implant and significant reduction of carpal height was noticed in 82.5% of the prosthesis. Revision procedures were performed in eleven cases. We conclude that the clinical and radiological results of Swanson silicone interposition arthroplasty will deteriorate with the passage of time. Beyond the potential deleterious effects of silicone, long-term radiological complications such as implant fracture, subsidence and carpal collapse are the main disadvantages of Swanson arthroplasty of the wrist. We therefore currently recommend the MPH-total wrist design in patients with rheumatoid arthritis.

Activities of Daily Living↗
PubMed2001

Acute aortic dissection during pregnancy.

We review the cases of two women with acute aortic dissection during their last trimester of pregnancy who underwent aortic root replacement. One patient with type A dissection had to undergo surgical intervention immediately, and required extracorporal membrane oxygenation for four days. The other patient with a pre-diagnosed Marfan's disease had suffered a type B dissection and had to undergo emergency operation after developing a type A dissection nine days later.

Adult↗