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W Schneider

Publications and source records attributed to W Schneider.

At least 37 records · Page 2Linked to original sources
PubMed2004

The effect of garlic on arteriosclerotic nanoplaque formation and size.

OBJECTIVE: In an in vitro biosensor model (PCT/EP 97/05212), the interplay between different lipoproteins in arteriosclerotic nanoplaque formation, as well as aqueous garlic extract (0.2-5.0 g/l from LI 111 powder) as a possible candidate drug against arterio/atherosclerosis were tested within the frame of a high throughput screening. METHODS: The processes described below were studied by ellipsometric techniques quantifying the adsorbed amount (nanoplaque formation) and layer thickness (nanoplaque size). A thorough description of the experimental setup has been given previously. RESULTS: Proteoheparan sulfate (HS-PG) adsorption to hydrophobic silica was monoexponential and after approximately 30 min constant. The addition of 2.52 mmol/l Ca2+ led to a further increase in HS-PG adsorption because Ca2+ was bound to the polyanionic glycosaminoglycan (GAG) chains thus screening their negative fixed charges and turning the whole molecule more hydrophobic. Incubation with 0.2 g/l aqueous garlic extract (GE) for 30 min did not change the adsorption of HS-PG. However, the following addition of Ca2+ ions reduced the increase in adsorption by 50.8% within 40 min. The adsorption of a second Ca2+ step to 10.08 mmol/l was reduced by even 82.1% within the next 40 min. Having detected this inhibition of receptor calcification, it could be expected that the build-up of the ternary nanoplaque complex is also affected by garlic. The LDL plasma fraction (100 mg/dl) from a healthy probationer showed beginning arteriosclerotic nanoplaque formation already at a normal blood Ca2+ concentration, with a strong increase at higher Ca2+ concentrations. GE, preferably in a concentration of 1 g/l, applied acutely in the experiment, markedly slowed down this process of ternary aggregational nanoplaque complexation at all Ca2+ concentrations used. In a normal blood Ca2+ concentration of 2.52 mmol/l, the garlic induced reduction of nanoplaque formation and molecular size amounted to 14.8% and 3.9%, respectively, as compared to the controls. Furthermore, after ternary complex build-up, GE similar to HDL, was able to reduce nanoplaque formation and size. The incubation time for HDL and garlic was only 30 min each in these experiments. Nevertheless, after this short time the deposition of the ternary complex decreased by 6.2% resp. 16.5%, i.e. the complex aggregates were basically resolvable. CONCLUSIONS: These experiments clearly proved that garlic extract strongly inhibits Ca2+ binding to HS-PG. In consequence, the formation of the ternary HS-PG/LDL/Ca2+ complex, initially responsible for the 'nanoplaque' composition and ultimately for the arteriosclerotic plaque generation, is decisively blunted.

Arteriosclerosis↗
PubMed2004

Evaluation of a wavelet-based computer-assisted detection system for identifying microcalcifications in digital full-field mammography.

PURPOSE: To evaluate a new wavelet-based computer-assisted detection (CAD) system for detecting and enhancing microcalcifications. MATERIAL AND METHODS: A total of 280 mammograms acquired by full-field digital mammography (Senographe 2000D; G.E. Medical Systems Milwaukee, Wisc., USA) were analyzed with and without a new wavelet-based CAD system for detecting and enhancing microcalcifications. The mammograms comprised roughly equal numbers of cases from each of the BIRADS (Breast Imaging, Reporting and Data System, according to the American College of Roentgenology) categories 1-5. Histologic confirmation was available for all of the 180 cases assigned BIRADS categories 3-5. Four readers interpreted all 280 images for suspicious microcalcifications using a scale of 1-5. The readers alternately assessed 5 images with and 5 without CAD. In a second reading immediately following the first, the readers had to reassess the 280 mammograms. The images that had already been interpreted without CAD were now presented with CAD and vice versa. The images were interpreted as soft copies on a diagnostic mammography workstation (Image Diagnost GmbH, Neufahrn/Munich, Germany). All images interpreted with CAD were presented with enhancement of microcalcifications by wavelet algorithms and prompting of microcalcifications. ROC (receiver operating characteristic) analyses were performed, and image interpretation time with and without CAD was measured. RESULTS: The overall time for interpretation required by all 4 readers together was 483 min with CAD compared to 580 min without CAD. ROC analysis revealed no significant advantage of CAD for the individual readers. Readers 3 (0.811/0.817) and 4 (0.799/0.843) had a slightly improved AUC (area under the curve) with CAD. Readers 1 and 2 had a slightly lower AUC with CAD (0.832 versus 0.861 and 0.818 versus 0.849). CONCLUSION: The CAD system significantly (P<0.05, t test) speeded up image interpretation with respect to the identification of microcalcifications, while the diagnostic quality remained almost identical under the study conditions.

Breast Diseases↗
PubMed2004

18FDG-PET in 733 consecutive patients with or without side-by-side CT evaluation: analysis of 921 lesions.

UNLABELLED: Side-by-side analysis of CT and conventional (18)FDG-PET in oncological imaging is well established. AIM of this study was to find out which patients or diagnostic groups may benefit the most from the newly introduced integrated PET/CT scanners. PATIENTS, METHODS: 407 consecutively admitted oncological patients with accompanying CT (groups A-D) and 326 patients without CT (groups E-G) were examined by conventional ring PET. Two nuclear medicine physicians and two radiologists assessed each patient's PET and CT scans for pathological lesions with regard to localisation and infiltration of adjacent anatomical structures. Patients without pathological PET findings were assigned to groups A (with CT) or E (without CT). If the localisation and/or extent of a pathological PET focus could only be assessed by taking into account the CT scan, the patient was assigned to group C (with CT) or G (without CT). If PET alone was sufficient for both questions the patient was assigned to groups B (with CT) or F (without CT). If neither method allowed for a precise lesion characterisation, the patient was assigned to group D. RESULTS: 38.6% (A, E) of all patients were PET-negative. PET alone sufficed in 20.6% (B, F). Side-by-side reading of PET and CT was needed for 43.5% (C) of patients referred to PET with a current CT. Side-by-side reading of CT and PET did not suffice for 7.3% (D) of patients in that cohort. A total of 28.2% (G) of the cases without CT would have profited from it. The most frequent oncological diagnoses in group D (PET and conventional CT not sufficient) were bronchial carcinoma with abdominal lesions, while in group G (without CT but CT required) head/neck cancer with thoracic lesions was predominant. CONCLUSIONS: Side-by-side reading of PET and already existing conventional CT failed to yield conclusive data with regard to lesion characterisation in only 7.4% of patients so that PET/CT might have been helpful in these cases. 28.2% of the patients without current CT would have profited from an initial PET/CT examination. On the other hand, 59.2% of all patients (negative PET or PET alone sufficing) did not require a CT for lesion characterisation.

Female↗
PubMed2004

Chevron osteotomy in hallux valgus. Ten-year results of 112 cases.

The Chevron osteotomy was described in 1976. There have, however, been only short- to mid-term follow-up reviews, often with small numbers of patients. We looked at 112 feet (73 patients) with a minimum follow-up of ten years following Chevron osteotomy with a distal soft-tissue procedure. Clinical evaluation was calculated using the hallux score of the American Orthopedic Foot and Ankle Society (AOFAS). For 47 feet (30 patients), the results were compared with those from an interim follow-up of 5.6 years. The AOFAS-score improved from a pre-operative mean of 46.5 points to a mean of 88.8 points after a mean of 12.7 years. The first metatarsophalangeal (MTP) angle showed a mean pre-operative value of 27.6 degrees and was improved to 14.0 degrees. The first intermetatarsal (IM) angle improved from a pre-operative mean value of 13.8 degrees to 8.7 degrees. The mean pre-operative grade of sesamoid subluxation was 1.7 on a scale from 0 to 3 and improved to 1.2. Measured on a scale from 0 to 3, arthritis of the first MTP joint progressed from a mean of 0.8 to 1.7. Comparing the results in patients younger and older than 50 years, the Chevron osteotomy performed equally in both age groups. Analysing the subgroup of 47 feet with a post-operative follow-up of both 5.6 and 12.7 years, the AOFAS pain and the overall score showed a further improvement between both follow-up evaluations. The MTP angle, first IM angle and sesamoid position remained unchanged. The progression of arthritis of the first MTP joint between 5.6 and 12.7 years post-operatively was statistically significant. Only one patient required a revision procedure due to painful recurrence of the deformity. Excellent clinical results following Chevron osteotomy not only proved to be consistent, but showed further improvement over a longer follow-up period. The mean radiographic angles were constant without recurrence of the deformity. So far, the statistically significant progression of first MTP joint arthritis has not affected the clinical result, but this needs further observation.

Adult↗
PubMed2004

Temporal arteritis with pauci-immune glomerulonephritis: a systemic disease.

Temporal arteritis is easily diagnosed and responds gratifyingly to treatment. Renal complications are unusual, but nevertheless occur. Earlier, an association between pauci-immune glomerulonephritis and temporal arteritis was shown. We present a patient who clearly had temporal arteritis but also developed cerebral hemorrhage, pulmonary infiltrates related to granulomatous pulmonary vasculitis, and pauci-immune glomerulonephritis. We suggest that temporal arteritis is neither always localized nor temporal. Instead, the condition can be a lethal, systemic disease. Renal involvement in patients with temporal arteritis is not common and the presence of glomerulonephritis is rare [Jennette and Falk 1994]. Lenz et al. [1998] described a patient who developed vision loss, optic nerve atrophy, elevated erythrocyte sedimentation rate, a positive rheumatoid factor and terminal glomerulonephritis. The renal biopsy showed focal and segmental necrotizing glomerulonephritis, despite negative antineutrophil cytoplasmatic antibodies (ANCA), antinuclear antibodies and antiglomerular basement membrane antibodies. Giant cells were identified in the necrotic vessel walls within the kidney. Immunofluorescence was negative and a diagnosis of ANCA-negative pauci-immune glomerulonephritis was made. The patient did not respond to immunosuppression and developed end-stage renal disease. Although the clinical attributes were consistent with temporal arteritis, no temporal artery biopsy was done in that patient. We recently treated a patient with temporal arteritis and pauci-immune glomerulonephritis. Our patient's course was somewhat different in comparison to the patient described by Lenz et al. [1998].

Aged↗
PubMed2003

Tissue engineering of peripheral nerves: Epineurial grafts with application of cultured Schwann cells.

After a simple nerve lesion, primary microsurgical suture is the treatment of choice. A nerve gap has to be bridged, with a nerve graft sacrificing a functioning nerve. Alternatively, tissue engineering of nerve grafts has become a subject of experimental research. It is evident that nerve regeneration requires not only an autologous, allogenous, or biodegradable scaffold, but additional interactions with regeneration-promoting Schwann cells. In this study, we compared epineurial and acellularized epineurial tubes with and without application of cultured Schwann cells as alternative grafts in a rat sciatic nerve model. Autologous nerve grafts served as controls. Evaluation was performed after 6 weeks; afterwards, sections of the graft and distal nerve were harvested for histological and morphometrical analysis. Compared to controls, all groups showed a significantly lower number of axons, less well-shaped remyelinizated axons, and a delay in clinical recovery (e.g., toe spread). The presented technique with application of Schwann cells into epineurial tubes did not offer any major advantages for nerve regeneration. Thus, in this applied model, neither the implantation of untreated nor the implantation of acellularized epineurial tubes with cultured Schwann cells to bridge nerve defects was capable of presenting a serious alternative to the present gold standard of conventional nerve grafts for bridging nerve defects in this model.

Animals↗
PubMed2003

[Replantation at lower leg level].

INTRODUCTION: Replantation in reconstructive surgery is an established procedure due to microsurgical techniques. It can be routinely performed in unilateral lower leg amputation. In some cases of bilateral amputation, in which orthotopic replantation is not possible due to the complex trauma, heterotopic replantation is a therapeutic option. This avoids prosthetic fitting. METHODS: We report five cases of orthotopic and two of heterotopic lower limb replantations. Functional outcome concerning sensibility, mobility, pain, and aesthetic result were assessed clinically and using a questionnaire. RESULTS: Functional outcome and patient satisfaction were good. The psychological situation of the patients as well as mobility and stability of the replanted limbs were satisfying. Heterotopically replanted patients found the replanted legs superior to the prostheses. CONCLUSIONS: We conclude that, in lower leg amputation, attempts should be made to replant the extremity. In bilateral lower leg amputations, at least one limb should be reconstructed, even if "only" a heterotopic replantation can be performed.

Accidents, Occupational↗
PubMed2003

[Myosonographic and electromyographic (EMC) evaluation of donor-site morbidity after microsurgical TRAM flap].

Due to improved microsurgical techniques the role of autologous breast reconstruction is expanding. One reason is the decreased donor-site morbidity compared to other techniques. Perforator based flaps (DIEP flaps) seemingly decrease the damage of the abdominal wall due to flap harvesting. However, complication rate in perforator flaps is still considered to be higher than in TRAM flaps. Additionally, operating time is increased due to the meticulous microsurgical dissection of perforators. To evaluate whether donor-site morbidity is caused by harvesting a part of the rectus muscle (as TRAM flaps), 15 patients after unilateral muscle sparing TRAM flap underwent EMG and myosonographic examination of the rectus muscle. EMG is the only technique to assess the muscle functionally, as the electrical activity of the muscle is recorded, and motor unit recruitment can be shown. EMG examination clearly revealed that harvesting of a muscle sparing TRAM flap did not impair the rectus muscle compared to the intact contralateral muscle. However, motor units were enlarged. Myosonography (in contrast to MRI) detected particular damage of isolated muscle fibres indicating nerve-related muscle changes. Taking all findings together, harvesting of a part of the rectus muscle shows a distinct damage to the muscle. The muscle however still acts functionally. This indicates that problems after harvesting a TRAM flap (bulging, hernias etc.) are not due to the partial removal of muscle, but due to the general dissection of the abdominal wall, as seen in other abdominal operations.

Adult↗
PubMed2003

[Suprascapular nerve entrapment].

Isolated compression of the suprascapular nerve is a rare entity, that is seldom considered in differential diagnosis of shoulder pain. Usually atrophy of supraspinatus and infraspinatus muscles is present, resulting in weakened abduction and external rotation of the shoulder. Mostly the patients do not note the paresis, but complain about a dull and burning pain over the dorsal shoulder region. In a proximal lesion (at level of the superior transverse scapular ligament) electromyography reveals changes in both muscles, while in a distal lesion (spinoglenoidal notch) only the infraspinatus shows a pathology. From 1996 to 2001 we diagnosed an isolated suprascapular entrapment in nine patients. Seven patients were operated: The ligament was removed and the nerve was neurolysed. The average age was 36 years. All patients showed pathological findings in electrophysiological and clinical examination. Five patients had an atrophy of both scapula muscles, two showed only infraspinatus muscle atrophy (one with a ganglion in the distal course of the nerve). Six patients were followed up. All showed an improvement. Pain disappeared and all patients were able to return to work and sport activities. Electrophysiological examination one year after operation revealed normal nerve conduction velocity. The number of motor units, however, showed a reduction by half compared to the healthy side. Lesions without history of trauma are usually caused by repetitive motion or posture. Weight lifting, volley ball and tennis promote the entrapment. Rarely a lesion (either idiopathic or due to external compression) is described for patients who underwent surgery. Patients with a ganglion or a defined cause of compression should be operated, patients who present without a distinct reason for compression should firstly be treated conservatively. Physiotherapy, antiphlogistic medication and avoiding of the pain triggering motion can improve the symptoms. However, if muscle atrophy is evident, an operation is indicated from our experience.

Adult↗
PubMed2003

Orthotopic and heterotopic lower leg reimplantation. Evaluation of seven patients.

Reimplantation is a well-established procedure in reconstructive surgery. This is especially so after amputation of the upper limb since prostheses provide limited function. In unilateral amputation of the lower leg orthotopic reimplantation is the treatment of choice. With bilateral amputation, in which orthotopic reimplantation is not possible because of the complexity of the trauma, heterotopic reimplantation is an option. We report five patients who received orthotopic and two who received heterotopic reimplantations of the lower leg. We assessed the functional outcomewith reference to cutaneous sensation, mobility, pain, and the cosmetic result. The functional outcome was good, as was the patients' satisfaction. Their mobility, stability, and psychological state were satisfactory. Patients with heterotopic reimplantations preferred the reimplanted leg to a prosthesis. Although reimplantation of the lower leg requires prolonged hospitalisation, delayed mobilisation and secondary operations, we conclude that there is an indication for this operation in order to improve the patient's quality of life.

Adolescent↗
PubMed2002

[Are inpatient rehabilitation or ambulatory physical therapy of patients with musculoskeletal problems effective and are patients referred to proper treatment?].

The aim of the present study was to investigate the effectiveness of an inpatient rehabilitation program and outpatient physiotherapy, respectively. Moreover, we wanted to know whether the referral to these two treatment paths was appropriate with regard to the patient's initial health status. According to the referring physician's indication patients with health problems in the cervical, lumbar spine, arm or leg were treated by an inpatient rehabilitation program or by outpatient physiotherapy. These two consecutively recruited patient cohorts were then compared. Those patients treated by the inpatient rehabilitation program differed from the outpatient group with regard to the initial health status and to age. Patients with musculoskeletal problems, who underwent an inpatient rehabilitation program, showed a significantly worse health and functional status than the outpatient group. Therefore, it can be concluded that the indication towards inpatient rehabilitation or outpatient physiotherapy was correctly given by the referring physicians. Patients treated by outpatient physiotherapy did also show a reduced health and functional status in comparison to the average population. Both types of treatment led to statistically significant and clinically relevant improvement of both the health and functional status in all patient groups.

Adult↗
PubMed2002

[Surgical therapy of scrotal edema in elephantiasis congenita hereditaria (Meige type)].

The underlying cause of primary lymphedema is a malformation of the lymph vessel system. Secondary lymphedemas can be due to infections, recurrent inflammation, hypoproteinemia, tumors, operations, or irradiation. As a reaction to persistent edema and interstitial macromolecules, fibrosis occurs. Recurrent inflammations of the indurated and edematous tissue are clinically impressive. The massive form of the scrotal lymphedema leads to painful tautness and sexual dysfunction. A concurrent penile edema can cause dysuria. The deformity of the affected extremities and organs not only leads to restriction of mobility but also to psychological stress due to the disfigurement, even as far as to social deprivation. We report on a surgical technique for treating pronounced scrotal edema by resection and neoscrotal reconstruction using ventral pedunculated scrotal skin flaps in cases of congenital hereditary elephantiasis of the Meige type.

Elephantiasis↗
PubMed2002

Core decompression in early stages of femoral head osteonecrosis--an MRI-controlled study.

We treated 45 hips with idiopathic necrosis of the femoral head stages I-III with core decompression. Average age of patients was 41 (27-68) years and average follow-up 68.9 (31-120) months. In 30 hip joints in stage I, 29 showed no radiographic progression and a complete remission of the changes consistent with necrosis on MRI at the last follow-up. In 27 patients the clinical result based on the Harris Hip Score (HHS) assessment--was excellent (average HHS 91.9 points). Of nine hips in stage II, four had received a total hip arthroplasty, one had deteriorated to stage IV, and four were still classified as stage II (average HHS 95 points). Of six hips in stage III, three had received a total hip arthroplasty and three had deteriorated to stage IV (average HHS 73 points).

Adult↗
PubMed2002

[Contractile reserve as a new parameter for determining the performance of the heart muscle using a noninvasive measuring method].

Chronic cardiac insufficiency is an illness with increasing epidemiological importance and mortality. Therefore different invasive and non-invasive investigation methods for early recording were developed. The left ventricular ejection fraction (LVEF) has played a special role in this direction. The determination of the contractile reserve by means of non-invasive measurement of blood pressure and flow through the aortic valve is a new and up to now widely unknown method for recording the capability and power reserve of the of myocardium. Since no comparative investigations are known from literature and results from a follow-up are not available yet, we tested whether, by means of contractile reserve, the discrimination of subjects with different cardiac power is possible or not. Forty-two men between 44 and 62 years of age belonging to three groups with different cardiac power (persistence trained, healthy subjects and patients with CHD) were examined non-invasively. The main result of the study is that it is possible to distinguish between the three groups significantly by means of the contractile reserve. The largest value (15.25 W +/- 3.46 W) was found in the "persistence trained" group, followed by the "healthy subjects" (10.85 W +/- 4.19 W). The smallest values were from the "patients" group (7.88 W +/- 2.95 W). The differences between the mean values of the CHD "patients" and the "persistence trained" were significant (p < 0.001). Similar comparisons of the groups of "healthy subjects" and "trained persons" and "healthy subjects" and "patients", respectively, yield p values of p = 0.007 and p = 0.040. These differences are also significant. This study is a first investigation and description of the method. A validation only can be achieved by follow-up investigations.

Adult↗
PubMed2002

Examination of the suitability of alpha-tocopherol as a stabilizer for ultra-high molecular weight polyethylene used for articulating surfaces in joint endoprostheses.

The lifetime of articulating surfaces in joint endoprostheses made of ultra-high molecular weight polyethylene (UHMW-PE), especially of UHMW-PE-cups of hip-endoprostheses, is usually limited to 10-15 years due to material failure as a result of oxidation of the UHMW-PE in vivo. In this study the suitability of the natural antioxidant alpha-tocopherol (vitamin E) as a stabilizer for UHMW-PE in these applications was investigated. Specimens with 0.1%, 0.2%, 0.4% and 0.8% w/w alpha-tocopherol as well as unstabilized samples were sintered and sterilized with gamma-rays at 25 kGy in accordance with standard processing methods of cups for total hip-endoprostheses. These specimens were aged in pure oxygen at 70 degrees C and 5 bar as well as in aqueous H2O2 at 50 degrees C. The degree of oxidation was observed by means of FTIR-spectroscopy, DSC analysis and mechanical testing. The FTIR-measurements showed that alpha-tocopherol can prolong the lifetime of UHMW-PE in an oxidative environment by a factor of more than 2.5. In the mechanical tests no embrittlement could be observed with the stabilized samples. A comparison with the standard antioxidant system Irganox 1010/Irgafos 168 (Ciba-Geigy, Switzerland) was carried out and revealed that alpha-tocopherol can even exceed the stabilization effect of this widely-used antioxidant system.

Journal Article↗
PubMed2002

Intimal plaque development and oxidative stress in cholesterol-induced atherosclerosis in New Zealand rabbits.

Although oxidative stress is well known in atherogenesis, the origin, nature and kinetics of free radicals involved have not been well described till now. Here, we correlated parameters of oxidative stress with cellular components during induction and stabilization of aortic intimal lesions which were induced in rabbits by feeding a cholesterol-enriched diet for 6 weeks and a normal diet for further 68 weeks. Plasma lipids, aortic plaque size and composition (macrophages, smooth muscle cells, oxidized LDL by morphometry), as well as aortic radical production (by luminol-enhanced chemiluminescence and TEMPO-9AC fluorescence) were measured after various time points. The parameters of oxidative stress were correlated with the different cellular components of the aortic plaques. The plaques increased until week 21, no significant regression was found until week 74, plasma cholesterol was maximal at week 6. Macrophages, oxidized LDL and generation of different species of free radicals were increased during plaque development, yet with different time kinetics. Whereas chemiluminescence correlated only weakly with the amount of intimal macrophages, strong correlations were found between TEMPO fluorescence and smooth muscle cells (r = 0.4778, P < 0.001) and between macrophages and oxidized LDL (r = 0.5896, P < 0.0001). Different indicators of oxidative stress were increased during plaque progression and stabilization. However, the various correlations show, that distinct types of reactive species secreted probably from macrophages and smooth muscle cells contribute to oxidative stress in the different phases of plaque development.

Animals↗