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T Fischer

Publications and source records attributed to T Fischer.

At least 19 recordsLinked to original sources
PubMed2006

[Renal transplant: color duplex ultrasound and contrast-enhanced ultrasound in the evaluation of the early postoperative phase and surgical complications].

Contrast ultrasound is a promising and straightforward method that is superior to established sonographic techniques such as conventional B-mode scanning which is used for volume measurement and hematoma demonstration. Color Doppler is important for the evaluation of rejection, the detection of perfusion defects, and complete vascularization in the diagnostic evaluation of kidney grafts. Moreover, contrast US has the potential for tumor characterization in transplanted kidneys. A single examination by contrast ultrasound can answer a variety of questions with respect to the early postoperative phase and chronic damage. New applications of contrast US will arise from the further technical development of ultrasound equipment. The rapid technical advances seen in recent years have been followed by the introduction of new software tools for the analysis of raw datasets or the improved visualization of microbubbles at very low energy. Initial studies show that efficient and early diagnosis of rejection is possible. Surgical complications like perfusion defects or hematoma can also be identified.

Animals↗
PubMed2006

Multivariate statistical analysis of metal concentrations in teeth of residents of Silesian region, southern Poland.

Concentrations of 11 metals (Cd, Cr, Cu, Fe, Mn, Pb, Zn, Na, K, Ca, and Mg) were assayed in the teeth of two populations of the Silesian region. The first group (n = 83) comprised the residents of Katowice-Szopienice, a town located in the center of the Upper Silesian industrial region, in close proximity to a Pb plant, whereas the other was a group of residents of the agricultural community Strumień (n = 44). The concentrations of all the trace metals were found to be higher in the teeth of Katowice-Szopienice residents. The methods of cluster analysis distinguished two clusters of metals in the teeth: essential (Ca, Na, Mg, Zn, and K) and trace (Cd, Mn, Cr, Cu, Fe, and Pb) elements. Euclidean distances reflected the differences in concentrations between the two groups. The results obtained were analyzed using principal component analysis. Four principal factors accounted for 68.1% of the total variance for Katowice-Szopienice residents and for 80.1% for Strumień residents. The first factor showed high contributions of Cu and Cr, elements present in humans as a result of diet, and also Mn for Katowice-Szopienice residents because of environmental contamination. The second factor was characterized by large Zn and Cd fractions and, for Katowice-Szopienice residents, Pb and K as well. The diversified exposure of both populations was reflected by the differences in Euclidean distances and contribution of particular elements with respect of principal components.

Adolescent↗
PubMed2006

Production of dense plasmas with sub-10-fs laser pulses.

Close to solid state density plasmas with peak electron temperatures of about 190 eV have been generated with sub-10-fs laser pulses incident on solid targets. Extreme ultraviolet (XUV) spectroscopy is used to investigate the K shell emission from the plasma. In the spectra, a series limit for the H- and He-like resonance lines becomes evident which is explained by pressure ionization in the dense plasma. The spectra are consistent with computer simulations calculating the XUV emission and the expansion of the plasma.

Journal Article↗
PubMed2006

Real-time elastography--an advanced method of ultrasound: First results in 108 patients with breast lesions.

OBJECTIVES: To evaluate whether real-time elastography, a new, non-invasive method for the diagnosis of breast cancer, improves the differentiation and characterization of benign and malignant breast lesions. METHODS: Real-time elastography was carried out in 108 potential breast tumor patients with cytologically or histologically confirmed focal breast lesions (59 benign, 49 malignant; median age, 53.9 years; range, 16-84 years). Tumor and healthy tissue were differentiated by measurement of elasticity based on the correlation between tissue properties and elasticity modulus. Evaluation was performed using the three-dimensional (3D) finite element method, in which the information is color-coded and superimposed on the B-mode ultrasound image. A second observer evaluated the elastography images, in order to improve the objectivity of the method. The results of B-mode scan and elastography were compared with those of histology and previous sonographic findings. Sensitivities and specificities were calculated, taking histology as the gold standard. RESULTS: B-mode ultrasound had a sensitivity of 91.8% and a specificity of 78%, compared with sensitivities of 77.6% and 79.6% and specificities of 91.5% and 84.7%, respectively, for the two observers evaluating elastography. Agreement between B-mode ultrasound and elastography was good, yielding a weighted kappa of 0.67. CONCLUSIONS: Our initial clinical results suggest that real-time elastography improves the specificity of breast lesion diagnosis and is a promising new approach for the diagnosis of breast cancer. Elastography provides additional information for differentiating malignant BI-RADS (breast imaging reporting and data system) category IV lesions.

Adolescent↗
PubMed2006

[A new method for standardized diagnosis following renal transplantation. Ultrasound with contrast enhancement].

Ultrasound (US) imaging is an important diagnostic tool following renal transplantation. Unfortunately, due to the heterogeneity of the recipients and their multimorbidity, imaging procedures in the early phase after kidney transplantation are difficult and of limited use. We performed a study to evaluate the use of a contrast enhancer for US examination as a standardized method in the follow-up of kidney transplant recipients.The study included 40 recipients: 32 were examined on the 5th to 7th day following transplantation and 8 patients at the time when clinically suspicious findings occurred (acute rejection, tumor, acute tubular necrosis). Following the intravenous application of the contrast medium, pictures were taken during the arterial and parenchymatous phase and compared with conventional B-mode and power Doppler pictures of the same visual plane. Three examiners assessed different parameters of the transplant organ (max. vascularized area, suspected hematomas, tumors, rejection, acute tubular necrosis). Findings were confirmed by histological results of a biopsy if rejection, tumor, or acute tubular necrosis were suspected. Application of ultrasound contrast medium significantly increased visualization of the vascularized kidney area. Also, US findings in the follow-up after acute rejection therapy corresponded with the clinical course; 19 hematomas could be detected with contrast medium compared to only 9 without. With contrast medium a perfusion deficit was detectable in three patients compared to one patient with power Doppler US. Also, US contrast medium helped to detect tumor vascularization in two patients in whom conventional sonography suspected no abnormality. Ultrasound contrast medium enhancement is a reproducible, reliable, and easy to apply method which is superior to conventional sonography in the follow-up after kidney transplantation. This method is also helpful to detect and control acute rejections and to better visualize hematomas, deficits of perfusion, and tumors.

Adolescent↗
PubMed2006

[Ten years of laparoscopic living kidney donation. From an extravagant to a routine procedure].

Ten years ago the first laparoscopic living donor nephrectomy (LDN) was performed. Today, LDN is a routine operation in many US-American transplantation centers and an increasing number of centers in Europe are practicing LDN. In this article the different aspects of LDN for donor, kidney, recipient and operating surgeon are evaluated. We performed a literature research concerning LDN and the different aspects. Our own experience, as the largest LDN center in Germany, is part of the evaluation. Laparoscopic extraction of a kidney from a living donor is as safe for the donor as the open approach. At the same time, LDN offers multiple advantages like reduced pain and shorter convalescence. For the donated kidney and the recipient no disadvantages occur from the laparoscopic technique, as long as special intra- and perioperative demands are met. For the operating surgeon multiple developments have expanded the technical armentarium. LDN is safe for donor, recipient and kidney. Central issue of an optimal LDN is sufficient experience with laparoscopic urological techniques.

Directed Tissue Donation↗
PubMed2006

[Acute ovarian vein thrombosis in the third trimestre].

BACKGROUND: Ovarian vein thrombosis is a known complication in the peri- and postpartum phase. Its incidence is documented as 1:600 to 1:2000. Concerning ovarian vein thrombosis in earlier stages of pregnancy there are only very few case reports. CASE REPORT: We report on a woman in her third pregnancy who presented with acute abdominal pain in the 27th week of gestation. After a long car drive she felt an acute pain in the upper right abdomen which moved down to the right lower abdomen. On admission the obstetrical examination showed no pathology. There were no contractions. Clinical and sonographic examination could not reveal the cause of the pain. As adequate analgesia failed to relieve the pain, an explorative laparotomy was performed. It showed a dilated right ovarian vein of 3 cm diameter with a thrombus reaching the confluence to the vena cava. The ovarian vessels were resected and the adnectomy on the right side performed. Anticoagulation was initiated. There were no complications during the postoperative course. The pregnancy proceeded normally. After 10 days the patient could be dismissed in good condition. Laboratory diagnostic showed an deficiency in protein C. At 39 weeks of gestation a planned caesarean section was performed without any complications.

Acute Disease↗
PubMed2006

[Characterization of sonographically detected breast lesions using three-dimensional data sets].

PURPOSE: The diagnostic value of 3D ultrasound (US) was evaluated in comparison to 2D US on the basis of a set of pre-defined criteria for breast lesions. The individual criteria were correlated with the histological findings and they were ranked according to their significance for lesion characterization in both 3D US and 2D US. MATERIALS AND METHODS: A total of 92 breast lesions were examined of which 61 were malignant and 31 were benign, as confirmed by histology of core biopsy specimens (Aplio 80, Toshiba, Otawara, Japan). The 2D and 3D data sets were stored digitally. The vascular tree was stored separately using 3D fusion. In addition, a power Doppler (PD) examination was performed. A total of 644 individual images were evaluated by two independent readers. The lesions were evaluated using established criteria (BI-RADS classification). For statistical evaluation, the individual US measurements were classified according to the following two groups: those suggesting malignant lesions and those suggestive of benign lesions. Pearsons's chi-square test was performed for both groups. The 2D and 3D techniques were compared directly using kappa (kappa) statistics. Odds ratios (OR) were determined for the purpose of weighting the individual criteria. The sensitivities and specificities of 2D and 3D US were calculated. RESULTS: The diagnostic value of 3D US was comparable to that of 2D US, with only slight differences observed for specific measurements. Analysis of 2D US data indicated that there was a strong correlation between malignant tumor growth and two specific 2D criteria: lesion margin and effect of the lesion on adjacent breast tissue (r (2) = 0.632, p < 0.001). Analysis of 3D images indicated that the significant measurements for tumor malignancy were shape and lesion margin in sagittal, transverse (r (2) = 0741, p < 0.001), and frontal views (r (2) = 0.592, p < 0.001) as well as retraction and lesion demarcation in the frontal views (r (2) = 0.649, p < 0.001). The comparison of 2D and 3D yielded primarily moderate (kappa = 0.412) to good (kappa = 0.789) agreement between the individual criteria. Crucial criteria for lesion characterization were the effect of the lesion on adjacent breast tissue (OR 47.8 [16.0-143.3]) in 2D US and the lesion margin (OR 36.4 [15.3-86.6]) and the 3 additional criteria of the frontal plane (OR 21.9-32.9) in 3D US. The two US techniques had comparable sensitivities (2D/3D 95-97 %/92-95 %) and specificities (2D/3D 54-58 %/61-67 %). The reconstructed 3D view of the vascular tree was subjectively considered to be helpful by both readers. A higher degree of vascularization was observed with 3D US. CONCLUSIONS: The diagnostic role of 3D ultrasound in the diagnostic evaluation of breast cancer is comparable to that of 2D US. Our findings illustrate the significance of the evaluation of frontal views in lesion characterization.

Adult↗
PubMed2006

Histone deacetylase inhibition by valproic acid down-regulates c-FLIP/CASH and sensitizes hepatoma cells towards CD95- and TRAIL receptor-mediated apoptosis and chemotherapy.

Hepatocellular carcinoma (HCC) is highly resistant to chemotherapy, leading to a poor prognosis of advanced disease. Inhibitors of histone deacetylase (HDACi) induce re-differentiation in tumor cells and thereby re-establish sensitivity towards apoptotic stimuli. HDACi are entering the clinical stage of tumor treatment, and several substances are currently being tested in clinical trials to prove their efficacy in the treatment of leukemias and solid tumors. In this study, we investigated the impact of the HDACi valproic acid (VA) on TRAIL- and CD95-mediated apoptosis in hepatoma cells, as well as its sensitizing effect on a chemotherapeutic agent. Treatment of HepG2 cells with VA increased sensitivity to CD95-mediated apoptosis (4% apoptosis vs. 42%), and treatment with epirubicin (74% vs. 90% viability). Caspase-3 activity was significantly enhanced in cells treated with VA plus anti-CD95 antibodies compared to cells treated with antibodies alone. In parallel, VA strongly augmented the effect of TNF-related apoptosis-inducing ligand (TRAIL or Apo2 ligand) on HepG2 cells (10% vs. 58% apoptosis). VA induced down-regulation of cellular FLICE-inhibitory protein (c-FLIP/CASH, also known as Casper/iFLICE/FLAME-1/CLARP/MRIT/usurpin), providing a possible molecular mechanism underlying the increased sensitivity towards cell death-mediated apoptosis. HDAC inhibitors are a promising class for the treatment of leukemias. In addition, among other class members, VA deserves further evaluation as a treatment option for patients with advanced HCC.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Cine magnetic resonance imaging vs high-resolution ultrasonography for detection of adhesions after laparoscopic and open incisional hernia repair: a matched pair pilot analysis.

BACKGROUND: Intraabdominal adhesions represent nonspecific complications before or after laparoscopic or open incisional hernia repair. The objective of this matched control pilot study was to display long-term adhesions noninvasively by applying functional cine magnetic resonance (MR) imaging, as compared with applying high-resolution ultrasonography (US). METHODS: The study group, composed of 17 consecutive patients (12 men and 5 women; mean age, 52 years), underwent laparoscopic intraperitoneal onlay mesh repair using expanded polytetrafluoroethylene (ePTFE) mesh. Their mean body mass index was 30 kg/m(2), and the size of the hernia was 95 cm(2). Another group, matched for age, gender, and type of hernia, was subjected to open abdominal wall repair using the preperitoneal sublay technique with a large-pore, low-weight polypropylene mesh. For cine MR imaging (1.5 T), section-by-section dynamic depiction of induced visceral slide throughout the entire abdomen was achieved by applying transverse or sagittal true fast imaging with steady-state precession sequences. The location and type of adhesions were compared with high-resolution ultrasonography using nine segments of the abdominal map. RESULTS: The patients subjected to laparoscopic and open incisional hernia repair were examined 16 and 28 months after surgery. The findings showed functional cine MR imaging as superior to high-resolution ultrasonography for assessing the amount of intraabdominal adhesions (n = 53 vs n = 3; p < 0.01). Most frequently, adhesions were seen between small bowel loops and the abdominal wall (n = 22), followed by bowel-to-bowel adhesions (n = 19; p < 0.05). However, adhesions between small bowel loops and the abdominal wall occurred more frequently after open mesh repair (p < 0.05). Furthermore, a strong correlation was observed between patient complaints and findings with cine MR imaging (p < 0.05). Maximum pain correlated significantly with the region of the most distinctive adhesions (p < 0.05). CONCLUSIONS: Functional cine MR imaging represents a reliable noninvasive technique for detecting long-term adhesions after open and laparoscopic incisional hernia repair. The study results suggest that this approach has distinct advantages over high-resolution ultrasonography.

Adult↗
PubMed2005

[3D ultrasound (3D US) in the diagnosis of focal breast lesions].

BACKGROUND: It was to analyse whether 3D breast US is able to enhance the diagnosis of focal breast lesions. MATERIAL AND METHODS: 60 patients were examined with 2D- and 3D US (GE logiq 9, 14 MHz). The solid lesions were analyzed by using the BIRADS classification. As standard of reference, histopathologic results were available in all cases. RESULTS: 38 malignant and 22 benign lesions were analyzed. With 2D US the sensitivity/specificity was 92/81%, with 3D US 97/72%, and by combination of 2D and 3D 97/81%. Characteristics of benign solid masses included a round or oval shape as well as clearly defined and sharply demarcated margins. CONCLUSIONS: 3D US allows to demonstrate breast masses in multiple planes. Distorsion of the surrounding soft tissues is an important sign indicative of malignancy.

Breast Neoplasms↗
PubMed2005

Accidental head injuries in children under 5 years of age.

AIM: To evaluate the type and nature of head injuries sustained by children under the age of 5 years who present to a busy accident and emergency (A&E) department following an accidental fall. MATERIALS AND METHODS: This study included all children under the age of 5 years, who over an 8-month period were referred to our A&E Department with head injury following an accidental fall. Data were collected regarding the height of the fall, whether or not stairs were involved, the type of surface that the child landed on and the height of the child. This was correlated with any soft-tissue injury or skull fracture. RESULTS: A total of 72 children (aged 4 months to 4.75 years) fulfilled all the criteria for an accidental fall. The heights of the falls ranged from less than 50 cm to over 3 m, with the majority below 1 m. Of the falls, 49 were onto a hard surface and 23 were onto a soft surface. Of the 72 children, 52 had visible evidence of head injury, 35 (71%) of 49 being the result of falls onto hard surfaces and 17 (74%) of 23 onto soft (carpeted) surfaces. There was no significant difference in the type of surface that resulted in a visible head injury. A visible head injury was seen in all children who fell from a height of over 1.5 m and in 95% of children who fell over 1 m. Of the 72 children, 32 (44%) had skull radiographs performed in accordance with established guidelines and 4 (12.5%) were identified as having a fracture. Of the 3 linear parietal fractures 2 were inflicted by falls of just over 1 m (from a work surface) and 1 by a fall of 80 to 90 cm onto the hard-edged surface of a stone fire surround. The 4th was a fracture of the base of skull following a fall from more than 3 m (from a first-storey window). CONCLUSIONS: In the vast majority of domestic accidents children do not suffer significant harm. Skull fractures are rare and probably occur in less than 5% of cases. To cause a skull fracture the fall needs to be from over 1 m or, if from a lesser height, then a small-area impact point should be considered an integral component of the injury.

Accidental Falls↗
PubMed2005

[Visualization and quantification of large bowel motility with functional cine-MRI].

PURPOSE: To develop and evaluate a method to visualize and quantify large bowel motility using functional cine MRI. METHODS: Fifteen healthy individuals (8 males, 7 females, 20 to 45 years old) with no history or present symptoms of bowel disorders were enrolled in a functional cine MRI examination at 6 a. m. after a starving phase for at least eight hours before and after oral administration of Senna tea (mild stimulating purgative). Two consecutive sets of repeated measurements of the entire abdomen were performed using a 1.5 T MRI system with coronal T2-weighted HASTE sequences anatomically adjusted to the course of the large bowel. A navigator technique was used for respiratory gating at the level of the right dorsal diaphragm. The changes in diameter (given in cm) were measured at 5 different locations of the ascending (AC), transverse (TC) and descending colon (DC), and assessed as parameters for the bowel motility. RESULTS: The mean values as a statistical measure for large bowel relaxation were determined. Before ingestion of Senna tea, the mean diameter measured 3.41 cm (ascending colon), 3 cm (transverse colon) and 2.67 cm (descending colon). After the ingestion of Senna tea, the mean diameter increased to 3.69 cm (ascending colon) to 3.4 cm (transverse colon) and to 2.9 cm (descending colon). A statistically significant difference was demonstrated with the Wilcoxon test (level of confidence 0.05). For the determination of dynamic increase, the changes of the statistical scatter amplitude to the mean value were expressed as percentage before and after the ingestion of Senna tea. Thereby, an increase in variation and dynamic range was detected for the AC (112.9 %) and DC (100 %), but a decrease in the dynamics for the TC (69 %). CONCLUSION: A non-invasive method for the assessment of bowel motility was developed for the first time. The use of functional cine MRI utilizing a prokinetic stimulus allowed visualisation and quantification of large bowel motility. Further studies have to determine whether this technique is clinically relevant.

Adult↗
PubMed2005

[Transarterial embolization for uterine fibroids: clinical success rate and results of magnetic resonance imaging].

PURPOSE: To analyze the clinical success rate and the findings of magnetic resonance imaging (MRI) after uterine artery embolization of symptomatic leiomyomas (fibroids) of the uterus. MATERIALS AND METHODS: This is a prospective single-center case study of 80 consecutively treated patients, followed for 3 - 6 months (group I), 7 - 12 months, (group II), and 13 - 25 months (group III). MRI was used to determine the uterine volume and size of the dominant leiomyoma. Symptoms and causes requiring repeat interventions were analyzed. RESULTS: Significant (p < 0.01) volume reduction of the uterus (median: 34.95 % confidence interval [CI]: 30.41 - 41.76 %) and dominant leiomyoma (median: 52.07 %, CI: 47.71 - 61.57 %) was found. The decrease in uterine volume (I-III: 22.68 %, 33.56 %, 47.93 %) and dominant leiomyoma volume (I-III: 41.86 %, 62.16 %, 73.96 %) progressed with the follow-up time. Bleeding resolved significantly (p < 0.0001) in all three follow-up groups (groups I-III: 92.86 %, 95.23 %, 96.67 %). Furthermore, urinary frequency (groups I-III: 70 %, 75 %, 82.35 %) and sensation of pelvic pressure (groups I-III: 42.86 %, 60 %, 93.75 %) improved, which was statistically significant in group III (p < 0.01). The number of leiomyomas correlated (p < 0.05) with improvement of the bleeding and the pelvic pressure. Repeat therapy was necessary for complications in four patients (5 %) and for therapeutic failure in three patients (3.8 %). Permanent amenorrhea was observed in four patients (5 %) of age 45 years or older. CONCLUSION: Uterine artery embolization of uterine leiomyomas has a high clinical success rate with an acceptable incidence of complications and repeat interventions.

Adult↗
PubMed2005

[Endovenous treatment of primary varicose veins: an effective and safe therapeutic alternative to stripping?].

Endovenous laser therapy (EVLT) is a new, minimally invasive therapeutic option for treating primary varicose veins and provides an effective and safe alternative to conventional surgical management (stripping). Short-term and intermediate-term outcome is comparable to surgical stripping in terms of elimination of venous reflux (90 % - 98 %), resolution of visible varices (85 %), and improvement of subjective complaints such as sensations of heaviness and tension (96 %). Complications occur in 1 % - 3 % of cases, which is markedly below the rate of conventional surgical management (up to 30 %). The intermediate-term incidence of recurrent varicosis in a vein treated by EVLT depends on the laser fluence applied and is reported to range from 7 % - 9 % compared to 10 % - 20 % after surgical intervention. Based on a review of the current literature and our own experience, this survey article presents an overview of the indications and contraindications, the technique and pathophysiology of laser-induced venous occlusion, and the results and possible complications of EVLT.

Anesthesia↗
PubMed2005

[Prevention of preeclampsia].

Preeclampsia is accompanied by high fetal and maternal morbidity and mortality and to a high degree responsible for preterm delivery. The pathophysiologic mechanisms underlying this disease remain poorly understood. Accordingly, only few causative or preventive therapeutical strategies are known. One such example for a preventive strategy is the use of aspirin (ASA) which directly affects the imbalance of vasodilative prostacycline and vasoconstrictive thromboxane. Recently, some studies are indicating a preventive effect of vitamin C and E substitution. In contrast, early antihypertensive therapy did not prevent later progression of the disease. Furthermore, sodium restriction, calcium and magnesium substitution, fish oil substitution, or steroid therapy are without any effect regarding the later development of preeclampsia. It is of utmost importance to further elucidate underlying pathophysiological mechanisms to improve therapeutical and preventive strategies.

Aspirin↗