Publications by authors named "Alexander KreSS"

We present a comprehensive dataset comprising head- and eye-centred video recordings from human participants performing a search task in a variety of Virtual Reality (VR) environments. Using a VR motion platform, participants navigated these environments freely while their eye movements and positional data were captured and stored in CSV format. The dataset spans six distinct environments, including one specifically for calibrating the motion platform, and provides a cumulative playtime of over 10 h for both head- and eye-centred perspectives.

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Self-motion induces sensory signals that allow to determine travel distance (path integration). For veridical path integration, one must distinguish self-generated from externally induced sensory signals. Predictive coding has been suggested to attenuate self-induced sensory responses, while task relevance can reverse the attenuating effect of prediction.

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Self-motion through an environment induces various sensory signals, i.e., visual, vestibular, auditory, or tactile.

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The gold standard of saving fresh tissue in liquid nitrogen has some serious disadvantages in that this process is not available in daily medical routine practices even in many tumor centers. Our approach of a new minimally invasive technique is obtaining urothelial cells via micro-brushing the urinary bladder on the occasion of urological routine methods such as transurethral resection (TUR). Urothelial cells were obtained from 25 patients via two different micro-brushes from tumor tissue and from macroscopically healthy tissue during TUR.

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Introduction: The early development of progressive scoliosis with pelvic obliquity is the most significant orthopaedic problem for non-ambulatory children with spinal muscular atrophy (SMA).

Patients: 24 SMA patients were operated on for scoliosis using the ISOLA(®) system and 17 patients using a telescopic rod. The average age at spinal surgery was 12.

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Purpose: Bone loss around uncemented femoral components is suspected to precede implant loosening and contribute to problems in revision surgery. Short-stemmed cementless femoral components are designed to preserve proximal femoral bone stock and ultimately the longevity of the prosthesis.

Methods: With quantitative computed tomography-assisted osteodensitometry, we prospectively analyzed femoral cortical and cancellous bone density (BD) and contact area changes of an uncemented collum femoris preserving stem (n = 38) 10 days, 1, 3 and 7 years post-operatively.

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Recently, rs11892031[A] has been identified in a genome-wide association study (GWAS) to confer increased risk of urinary bladder cancer (UBC). To confirm this association and additionally study a possible relevance of exposure to urinary bladder carcinogens, we investigated the IfADo UBC study group, consisting of eight case-control series from different regions including 1,805 cases and 2,141 controls. This analysis was supplemented by a meta-analysis of all published data, including 13,395 cases and 54,876 controls.

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The impact of total hip arthroplasty on strain adaptive bone remodeling has been extensively analyzed by dual-energy x-ray absorptiometry. In this study, we present a prospective computed tomography-assisted study of periacetabular cortical and cancellous bone mineral density (in milligrams of calcium hydroxyapatite [CaHA] per milliliter, or mgCaHA/mL) changes 10 days and 1, 3, and 7 years after press-fit cup implantation for 38 hips in vivo. Cancellous bone mineral density decreased by Ø -63% ventral and Ø -85% dorsal to the cup; cortical bone mineral density, by Ø -22% ventral and Ø -18% dorsal to the cup.

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Currently, twelve validated genetic variants have been identified that are associated with urinary bladder cancer (UBC) risk. However, those validated variants explain only 5-10% of the overall inherited risk. In addition, there are more than 100 published polymorphisms still awaiting validation or disproval.

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Even though periprosthetic bone loss is common after total hip arthroplasty, there is no scientific evidence whether it compromises the survival of the prosthesis. Using quantitative computed tomography-assisted osteodensitometry, we determined the pattern of periacetabular bone density (BD) changes of two different press-fit cups (54 hips) 10 days, 1 year and 3 years post-operatively. We measured cortical and cancellous BD at three points of time and evaluated the effects of patient-specific characteristics [age, gender, body mass index (BMI)], clinical function, and BD at index operation.

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Background: As a follow-up of a previously reported three-year study, we analyzed the periprosthetic acetabular cortical and cancellous bone density changes at ten years after implantation of a press-fit cup.

Methods: Prospective clinical, radiographic, and quantitative computed tomography examinations were performed within ten days and at mean periods of one, three, and ten years after total hip arthroplasty with a press-fit cup, a femoral stem with a tapered design, and alumina-alumina pairing. Periacetabular cortical and cancellous bone density (mg CaHA/mL) in the cranial, ventral, and dorsal regions about the cup were measured for twenty-four hips in vivo.

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Genotyping N-acetyltransferase 2 (NAT2) is of high relevance for individualized dosing of antituberculosis drugs and bladder cancer epidemiology. In this study we compared a recently published tagging single nucleotide polymorphism (SNP) (rs1495741) to the conventional 7-SNP genotype (G191A, C282T, T341C, C481T, G590A, A803G and G857A haplotype pairs) and systematically analysed if novel SNP combinations outperform the latter. For this purpose, we studied 3177 individuals by PCR and phenotyped 344 individuals by the caffeine test.

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Ceramic-on-ceramic coupling is thought to be a durable alternative to metal- or alumina-on-polyethylene pairing. No evidence exists suggesting superior clinical and radiological results for hydroxyapatite-coated stems versus uncoated stems. The aim of this study is to report the performance of an alumina-on-alumina bearing cementless total hip arthroplasty and to compare stems with a tapered design with and without hydroxyapatite coating.

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Single nucleotide polymorphism (SNP) rs710521[A], located near TP63 on chromosome 3q28, was identified to be significantly associated with increased bladder cancer risk. To investigate the association of rs710521[A] and bladder cancer by new data and by meta-analysis including all published data, rs710521 was studied in 1,425 bladder cancer cases and 1,740 controls that had not been included in previous studies. Blood samples were collected from 1995 to 2010 in Germany (n = 948/1,258), Hungary (n = 262/65), Venezuela (n = 112/190) and Pakistan (n = 103/227) supplemented by a meta-analysis of 5,695 cases and 40,187 controls.

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Aim: Tissue sparing hip prostheses are becoming more and more popular especially for the treatment of younger patients. The objective of this study was to evaluate the clinical and radiological results after insertion of a tissue sparing hip prosthesis.

Method: In 47 consecutive non-selected patients (50 hips), the clinical and radiographic results of cementless total hip arthroplasty using a collum femoris preserving stem, a pressfit cup and an alumina-polyethylene pairing were prospectively evaluated.

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Background: Aseptic implant loosening and periprosthetic bone loss are major problems after total hip arthroplasty (THA). We present an in vivo method of computed tomography (CT) assisted osteodensitometry after THA that differentiates between cortical and cancellous bone density (BD) and area around the femoral component.

Method: Cortical and cancellous periprosthetic femoral BD (mg CaHA/mL), area (mm(2)) and contact area between the prothesis and cortical bone were determined prospectively in 31 patients 10 days, 1 year, and 6 years after uncemented THA (mean age at implantation: 55 years) using CT-osteodensitometry.

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Stress-shielding and periprosthetic bone loss after total hip arthroplasty (THA) may be clinically relevant for high-demand patients. Analysis of cortical and cancellous bone density (BD) changes in vivo after THA is of interest to basic science researchers and joint reconstruction surgeons. An insufficient periprosthetic bone stock may predispose to migration, early mechanical failure, and major problems in revision surgery.

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Periprosthetic bone loss after total hip arthroplasty is common. It can be progressive and, in the extreme, may compromise survival of the prosthesis. With quantitative computed tomography, we determined the pattern of periacetabular cortical and cancellous bone density changes after press-fit cup implantation with alumina liners.

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Introduction: Proximal tibial bone quality is an important factor in implant mechanical stability following total knee arthroplasty. Quantitative computed tomography (CT) osteodensitometry has been used to measure the change in bone density post-operatively. We sought to validate the inter-observer reliability of these measurements.

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Background: There are few dual X-ray absorptiometry (DXA) studies on periacetabular bone density changes after cup implantation. This study was designed to analyze the load-transfer mechanism and stress pattern of periacetabular cortical and cancellous bone after implantation of a ihemispherical titanium alloy press-fit cup with alumina-alumina pairing in vivo. We introduced a novel method of computed tomography (CT)-assisted osteodensitometry.

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Introduction: This study was initiated to evaluate the reproducibility of a novel method for measuring the periacetabular bone density after insertion of cemented and uncemented acetabular cups using CT in vivo.

Materials And Methods: CT scans were obtained from 20 patients after cemented polyethylene cup implantation (ZCA, Zimmer, USA) and 20 patients after uncemented titanium alloy cup fixation (Cerafit, Ceraver, France). A manual segmentation of cancellous and cortical pelvic bone ventral, dorsal and cranial to the cup was undertaken.

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