U. Haller
University of Zurich
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Featured researches published by U. Haller.
Obstetrics & Gynecology | 1995
Gabriel N. Schaer; Ossi R. Koechli; Bernhard Schuessler; U. Haller
Objective To assess the reproducibility of a new method for evaluation of the bladder neck with perineal ultrasound and to compare it with lateral chain urethrocystography. Methods In the first phase, two investigators examined 40 patients using perineal ultrasound to assess the reproducibility of a new measurement method for the determination of the bladder neck position. In the second phase, 60 patients were evaluated by perineal ultrasound and lateral chain urethrocystography. Results With perineal ultrasound, there was good interexaminer agreement for determining bladder neck position, funneling, and bladder neck descent at rest and during the Valsalva maneuver, but not for the posterior angle β during straining. Comparisons of sonographic and x-ray assessments showed good agreement for the bladder neck position at rest, but not during Valsalva, whereas the posterior angle, funneling, and bladder base descent differed between the two techniques at rest as well as during Valsalva. Conclusion With our new method for determining the position of the bladder neck, perineal ultrasound is reliable technique that allows reproducible static and dynamic evaluation. Lateral chain urethrocystography is superior to perineal ultrasound only if bladder neck funneling is the aim of the evaluation; it is inferior if bladder neck mobility during maximal Valsalva is being investigated.
European Radiology | 2000
Rahel A. Kubik-Huch; W. Dörffler; G. K. von Schulthess; B. Marincek; O.R. Köchli; Burkhardt Seifert; U. Haller; Hans C. Steinert
Abstract. The aim of this study was to compare prospectively the accuracy of whole-body positron emission tomography (PET), CT and MRI in diagnosing primary and recurrent ovarian cancer. Nineteen patients (age range 23–76 years) were recruited with suspicious ovarian lesions at presentation (n = 8) or follow-up for recurrence (n = 11). All patients were scheduled for laparotomy and histological confirmation. Whole-body PET with FDG, contrast-enhanced spiral CT of the abdomen, including the pelvis, and MRI of the entire abdomen were performed. Each imaging study was evaluated separately. Imaging findings were correlated with histopathological diagnosis. The sensitivity, specificity and accuracy for lesion characterization in patients with suspicious ovarian lesions (n = 7) were, respectively: 100, 67 and 86 % for PET; 100, 67 and 86 % for CT; and 100, 100 and 100 % for MRI. For the diagnosis of recurrent disease (n = 10), PET had a sensitivity of 100 %, specificity of 50 % and accuracy of 90 %. The PET technique was the only technique which correctly identified a single transverse colon metastasis. Results for CT were 40, 50 and 43 %, and for MRI 86, 100 and 89 %, respectively. No statistically significant difference was seen. Neither FDG PET nor CT nor MRI can replace surgery in the detection of microscopic peritoneal disease. No statistically significant difference was observed for the investigated imaging modalities with regard to lesion characterization or detection of recurrent disease; thus, the methods are permissible alternatives. The PET technique, however, has the drawback of less accurate spatial assignment of small lesions compared with CT and MRI.
International Journal of Cancer | 2001
André Fedier; Viola A. Schwarz; Heinrich Walt; Renato Delli Carpini; U. Haller; Daniel Fink
Sporadic breast carcinomas demonstrate microsatellite instability, reflecting the presence of DNA mismatch repair‐deficient cells, in about one fourth of cases at the time of diagnosis. Loss of DNA mismatch repair has been reported to result in resistance not only to cisplatin and alkylating agents but also to the topoisomerase II poison doxorubicin, suggesting an association between DNA mismatch repair and topoisomerase II poison‐induced cytotoxicity. Our study investigates the relationship between loss of MSH2 or MLH1 function and sensitivity to the topoisomerase I and II poisons, and to the taxanes, 2 classes of cytotoxic drugs commonly used in breast cancer. Two pairs of cell lines proficient and deficient in mismatch repair due to loss of either MSH2 or MLH1 function were used. Loss of either MSH2 or MLH1 function resulted in resistance to the topoisomerase II poisons doxorubicin, epirubicin and mitoxantrone, whereas only loss of MLH1 function was associated with low‐level resistance to the topoisomerase I poisons camptothecin and topotecan. In contrast, there was no resistance to docetaxel and paclitaxel. Our data support the hypothesis that both MSH2 and MLH1 are involved in topoisomerase II poison‐mediated cytotoxicity, whereas only MLH1 is involved in topoisomerase I poison‐mediated cytotoxicity. Since our study shows that loss of DNA mismatch repair does not result in resistance to the taxanes, these drugs can be recommended for use in breast cancer deficient in mismatch repair.
Journal of Photochemistry and Photobiology B-biology | 1998
Simone Müller; Heinrich Walt; Diana Dobler-Girdziunaite; Dagmar M. Fiedler; U. Haller
Photodynamic eradication of tumour cells depends on the presence of a photosensitizer and light delivery to the cells. The present study investigated the influence of fractionated light (on-off mode) on cell killing as documented by a colony-forming assay. Photosensitizers were m-THPC (ethanol soluble, Foscan) and m-THPC-MD (water soluble, both from Scotia Pharmaceuticals, Guildford, UK). Fractionated laser light at a wavelength of 652 nm with a light duration of 0.05 s was more effective than continuous illumination at the same power density for both photosensitizers. We propose that fractionated laser light is more toxic due to short phases of recovery during the dark intervals, probably resulting in more singlet oxygen under these conditions. By use of Foscan, for example, and fractionated laser light, a similar effect is expected for the treatment of solid tumours. In this case we expect improvements in photodynamic therapy (PDT) for patients by lowering the concentrations of photosensitizer and/or by reducing the applied light dose.
Breast Journal | 2004
Mathias K. Fehr; Rene Hornung; Zsuzsanna Varga; Daniel Burger; Thomas Hess; U. Haller; Daniel Fink; Gustav K. von Schulthess; Hans C. Steinert
Abstract: Axillary lymph node dissection (ALND) is the standard of care for nodal staging of patients with invasive breast cancer. Due to significant somatic and psychological side effects, replacement of ALND with less invasive techniques is desirable. The goal of this study was to evaluate the clinical usefulness of axillary lymph node (ALN) staging by means of positron emission tomography (PET) with 18F‐fluorodeoxyglucose (FDG) in breast cancer patients qualifying for sentinel lymph node biopsy (SLNB). FDG‐PET was performed within 1 week before surgery in 24 clinically node‐negative breast cancer patients with tumors smaller than 3 cm. Sentinel lymph nodes (SLNs) were identified by preoperative lymphoscintigraphy following peritumoral technetium 99m‐labeled colloid albumin injection, and by intraoperative gamma detector and blue dye localization. Following SLNB, a standard ALND was performed. Serial sectioning and immunohistochemistry of the SLN as well as standard histologic examination of the non‐SLN was performed. FDG‐PET detected all primary breast cancers. Staging of ALNs by PET was accurate in 15 of 24 patients (62.5%), whereas PET staging was false negative in 8 of 10 node‐positive patients and false‐positive in 1 patient. The sensitivity, specificity, positive predictive value, and negative predictive value of FDG‐PET for nodal status was 20%, 93%, 67%, and 62%, respectively. The mean diameter of false‐negative ALN metastases was 7.5 mm (range 1–15 mm). Lymph node staging using FDG‐PET is not accurate enough in clinically node‐negative patients with breast cancer qualifying for SLNB and should not be used for this purpose.
American Journal of Obstetrics and Gynecology | 1995
Gabriel N. Schaer; Ossi R. Koechli; U. Haller
OBJECTIVE Our purpose was to determine and compare the total annual costs for reusable and single-use laparoscopic instruments. STUDY DESIGN Records were kept over a 12-month period of all laparoscopic operations (performed only with reusable instrumentation), the surgical instruments used, depreciation costs, and all associated expenses (repairs, maintenance, replacements, cleaning, sterilization, wages). The total cost was then calculated and compared with the total cost (purchase price plus disposal fees) that single-use instruments would have caused for the same operations. RESULTS The total cost for single-use instruments would have been more than seven times that for reusable instruments. CONCLUSION We have decided to continue using reusable instruments for most of our laparoscopic operations. However, single-use instruments are used in situations in which they present a definite advantage. A proper balance is thus sought between the importance of cost factors, on the one hand, and the recognition of the need for the best instrument available for certain procedures, on the other.
Obstetrics & Gynecology | 1995
Gabriel N. Schaer; Ossi R. Koechli; Bernhard Schuessler; U. Haller
Objective To assess the efficacy of ultrasound contrast medium when imaging bladder neck anatomy in perineal ultrasound. Methods In 39 women with clinically and urodynamically proven urinary stress or stress-urge incontinence, a new echogenic contrast medium (Echovist) was administered transurethrally and perineal ultrasound was performed. Women were examined in the upright position both without and with ultrasound contrast medium at rest and during Valsalva maneuver, and the pictures of the bladder base, bladder neck, and urethra were compared. Results With the subject in the upright position, the contrast medium lay at the lowest point of the bladder and resulted in a reverse picture of the bladder base and bladder neck and clear visualization of these structures. In women with urinary stress incontinence, the ultrasound contrast medium entered the urethra during Valsalva, and bladder neck funneling was identified more accurately than without contrast medium. With Echovist, bladder neck funneling was detected in 38 of the 39 cases, compared with only 19 when it was not used. Furthermore, when the bladder neck, urethra, or bladder base were not visible with plain perineal ultrasound, they were seen when ultrasound contrast medium was used. The contrast agent was well tolerated, and there were no adverse side effects. Conclusion The use of ultrasound contrast medium improves visualization of the bladder neck anatomy. Bladder neck funneling and urinary leakage are seen more distinctly, and this improves the diagnostic reliability in female urinary stress incontinence.
Photochemistry and Photobiology | 1998
René Hornung; Heinrich Walt; Nigel E. A. Crompton; Kristin A. Keefe; Brigitte Jentsch; Gloria Perewusnyk; U. Haller; Ossi R. Köchli
Photodynamic therapy (PDT) uses laser light to activate a photosensitizer that has been absorbed preferentially by cancer cells after systemic administration. A photo‐toxic reaction ensues resulting in cell death and tissue necrosis. Some cells, however, may survive PDT. This study was performed to determine if surviving human breast cancer cells (MCF‐7) can become resistant to PDT, chemotherapy or radiotherapy. The MCF‐7 cells were cultured under standard conditions prior to being exposed to the photosensitizer, 5,10,15,20‐meta‐tet‐ra(hydroxyphenyl)chlorin (zn‐THPC), for 24 h and then irradiated with laser light (652 nm). Surviving cells were allowed to regrow by allowing a 2 week interval between each additional PDT. After the third and final treatment, colony formation assays were used to evaluate the sensitivity of cultured cells to ionizing radiation and PDT and the ATP cell viability assay tested in vitro chemosen‐sitivity. Flow cytometry was used to analyze the cell cycle. No alterations in the cell cycle were observed after three cycles of PDT with m‐THPC. Similar responses to chemotherapy and ionizing radiation were seen in control and treatment groups. The m‐THPC‐sensitized PDT did not induce resistance to subsequent cycles of PDT, chemo‐ or radiotherapy. Photodynamic therapy with m‐THPC may represent a novel adjunctive treatment of breast cancer that may be combined with surgery, chemotherapy or ionizing radiation.
Acta Obstetricia et Gynecologica Scandinavica | 1999
Daniel Fink; Daniele Perucchini; Gabriel N. Schaer; U. Haller
OBJECTIVE To investigate the differential diagnostic capacity of the frequency-volume chart in 132 women with urinary incontinence. MATERIAL AND METHOD For each patient, the readings of two 24-h frequency-volume charts were compared to the urodynamic diagnosis which was used as the gold standard in 73 genuine stress incontinent women, in 23 urge incontinent women, and in 36 women with mixed incontinence. RESULTS The total voided volume, the mean voided volume, the largest single voided volume, and the smallest single voided volume were statistically differentiating single parameters among the three groups (p<0.05). Applying logistic regression to the two well-defined groups of patients, the one with urge incontinence and the one with genuine stress incontinence, the frequency of micturition during nighttime revealed the best discriminatory power for these conditions. CONCLUSION This study shows that in the frequency-volume chart micturition during nighttime discriminates best between urge and stress incontinence.
Urology | 1996
Gabriel N. Schaer; Ossi R. Koechli; Bernhard Schuessler; U. Haller
OBJECTIVES To assess the efficacy of ultrasound medium when imaging bladder neck anatomy with perineal ultrasound. METHODS In 10 female patients with urinary stress or stress-urge incontinence, a new echogenic contrast medium (Echovist) was intravesically administered and perineal ultrasound performed. The examination was done with the women in the upright position both without and with ultrasound contrast medium at rest and during pressing, and the pictures of the bladder base, bladder neck, and urethra were compared. RESULTS With the patient in the upright position, the ultrasound contrast medium enters the urethra during pressing and bladder neck funneling is identified more accurately than without contrast medium. With Echovist, bladder neck funneling was detected in 9 of the 10 cases but without it in only 4 cases. CONCLUSIONS The use of ultrasound contrast medium results in a better visualization of the bladder neck anatomy. Bladder neck funneling and urinary leakage are seen more distinctly, and this improves the diagnostic reliability in female urinary stress incontinence. This pilot study supports the necessity for further investigations in the use of ultrasound contrast medium as a diagnostic improvement of perineal ultrasound.