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J Rost

Publications and source records attributed to J Rost.

At least 19 recordsLinked to original sources
PubMed2006

[Histopathologic quality of prostate core biopsy specimens: comparison of an MR-compatible biopsy needle and a ferromagnetic biopsy needle used for ultrasound-guided prostate biopsy].

PURPOSE: The histopathologic quality of core biopsy specimens obtained via MRI-guided prostate biopsy using a 16G MR-compatible needle was compared to that of biopsies obtained via ultrasound-guided biopsy using a conventional 18G stainless steel biopsy needle. MATERIAL AND METHODS: A retrospective analysis was performed for a total of 247 transrectal prostate biopsy specimens obtained from 32 patients. A total of 117 tissue cores were obtained from 15 patients (PSA of 10.8 ng/ml, age 64 years) who underwent an MRI-guided prostate biopsy using a 16G (1.7 mm) MR-compatible biopsy needle made of titanium alloy. The remaining 130 tissue cores were obtained from 17 patients (PSA of 6.7 ng/ml, age 68 years) who underwent a transrectal ultrasound-guided prostate biopsy using an 18G (1.3 mm) ferromagnetic stainless steel biopsy needle. The length and width of the histologic sections prepared from the tissue cores were measured to calculate the area. The histopathologic quality of the specimens was assessed microscopically using tissue fragmentation, the presence of crush artifacts, and the overall accessibility as criteria. Each of these features was assigned a score from 0 to 3. All 3 features contributed equally to the overall score which ranged from 0 (no tissue) to 9 (optimal quality). RESULTS: The overall quality scores assigned to the biopsies obtained with a 16G MR-compatible needle and an 18G ferromagnetic needle can be considered to be equivalent to a mean difference between patient related median scores of the specimens of - 0.05 (95 % confidence interval [- 0.46; 0.36]) and a given equivalence limit of 1. The MRI biopsies showed more tissue fragmentation (p = 0.001) but fewer crush artifacts (p = 0.022) while the accessibility did not differ significantly between the two needle types (p = 0.064). There was also no significant difference in the calculated areas of the tissue cores (p = 0.236). According to the different calibers of the biopsy needles, the lengths (p = 0.008) and widths (p = 0.000) of the biopsy specimens differed significantly. CONCLUSIONS: The core biopsy specimens obtained with an MR-compatible 16G titanium alloy biopsy needle are of the same histopathologic quality as specimens obtained with a ferromagnetic 18G stainless steel needle.

Aged↗
PubMed2005

Net radiation balance for two forested slopes on opposite sides of a valley.

Measurements of the net radiation balance of two forested sites on the opposite slopes of a valley in south-western Germany, made over 3 years, are presented in this study. Radiation sensors were mounted horizontally on two measurement towers above two beech stands. The direct part of the measured short-wave incoming radiation was adjusted according to the slope's angle to convert horizontally measured radiation data into surface-parallel radiation fluxes. During periods when contemporaneous measurements of slope-parallel and horizontal radiation fluxes were available, the calculation of surface-parallel radiation fluxes from the horizontally recorded net radiation components were compared with measured values. The net radiative fluxes parallel to the slopes were calculated for a period of 36 months and analysed. Results show that the different aspects of both sites cause significant differences of the net radiation balance. In June, when the elevation of the sun is highest, incoming solar radiation K downward arrow received on the NE-slope was 9% lower than K downward arrow received on the SW-slope. During the winter months, the differences were much greater and incoming solar radiation to the NE-slope was 50% of that to the SW-slope. Due to the differing solar irradiance, net radiation fluxes were significantly higher on the SW-slope than on the NE-slope. For long-wave radiation only small differences between both slopes could be found. Since radiative fluxes determine the energy balance and hence the microclimate and water balance of a forest stand, these differences in the net radiation balance between the slopes are important for the vegetation.

Altitude↗
PubMed1998

[Numerical studies of the effect of prosthetic implants on the strain energy density distribution in the femur].

In this study the distribution of the strain energy density (SED) in the natural femur as well as changes of it due to the implantation of an artificial hip joint has been investigated. Because of recently published theoretical considerations the volume related SED was used to describe the respective biomechanical loading situation completely. By means of parameter variation different load cases were simulated. The calculated SED-distributions were compared with the respective results of the natural femur. Thus, the known reasons of failures of hip joint prostheses has been proofed numerical. It was shown that the SED is a suitable mechanical parameter to simulate bone remodeling after hip joint replacement.

Biomechanical Phenomena↗
PubMed1998

[The relationship between the perceived threat of environmental problems and the formation of action intentions].

The results of a study using questionnaires at two measuring points in high schools in North Germany are reported and discussed. This article analyzes the students' reasons and motivation for more or less environmentally friendly behavior. An integrated theoretical concept of motivation for human action formed the theoretical basis. The action genesis process was subdivided into the phases of forming motives, intentions and volition. Following a presentation of this theoretical concept and its definition with regard to competing and compatible theoretical hypotheses, the methodological procedure is described whereby the various motivation structures of the pupils questioned were analyzed. Mixed distribution models were used which allow modelling of complex multivariate relationships (latent class analysis and mixed Rasch models). The results show strong positive relationships among the variables of the motivation, the intention and the volition phases, but with isolated area-specific motivation patterns and moderator effects of certain cognitive variables.

Adaptation, Psychological↗
PubMed1997

Standardization of gastric aspirate technique improves yield in the diagnosis of tuberculosis in children.

BACKGROUND: The diagnosis of tuberculous disease in children remains a difficult one, based on epidemiologic investigation, Mantoux skin testing and suggestive radiologic findings. Because children with pulmonary tuberculosis are unable to produce sputum, gastric aspirates remain the procedure of choice for microbiologic confirmation of tuberculous disease; however, yield is frequently low. OBJECTIVES: To evaluate the effect of a standardized gastric aspirate collection protocol on diagnostic culture yield. METHODS: The gastric aspirate culture yield for Mycobacterium tuberculosis in 13 historical control children with clinically confirmed tuberculosis from 1979 to 1994 was compared with the yield in 8 children with tuberculous disease after institution of a standardized gastric aspirate collection protocol involving physician education, strict timing of collection, base neutralization of aspirate specimens and expedited processing. RESULTS: Retrospective survey of gastric aspirate results in Rhode Island from 1979 to 1994 revealed that only 1 of 13 cases (8%) of pediatric pulmonary tuberculosis were confirmed in this manner. During a 12-month period after institution of a protocol, gastric aspirates yielded positive cultures in 4 of 8 children (50%) with pulmonary tuberculosis, a yield that compares favorably with the sensitivities of 20 to 52% published in the literature. CONCLUSIONS: Attention to the technique of gastric aspirate collection, and expedited processing in particular, appears to improve the yield of this diagnostic procedure for pediatric tuberculosis.

Child↗
PubMed1995

Food-initiated outbreak of methicillin-resistant Staphylococcus aureus analyzed by pheno- and genotyping.

An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) involving 27 patients and 14 health-care workers (HCW) was studied. The outbreak started in the hematology unit of the University Hospital Rotterdam, Dijkzigt, The Netherlands, and spread to the surgical unit. Twenty-one patients (77.8%) developed clinical disease, and five died. Subsequently, MRSA was detected in food and in the throat of one of the HCW who prepared food for hematology patients. Food contaminated by an HCW most likely caused the first case of MRSA septicemia. This route of transmission has not been described before. The outbreak strain was probably transmitted to the surgical unit by a colonized nurse, where it caused an explosive outbreak. Airborne probably transmitted to the surgical unit by a colonized nurse, where it caused an explosive outbreak. Airborne MRSA transmission played an important role in disseminating the organism. The outbreak was controlled within 6 months by intensifying surveillance, temporarily closing the affected wards, treating carriers, and instituting an MRSA ward outside the hospital. Phage typing, insertion sequence probing, protein A gene typing, and DNA fingerprinting by PCR revealed that all outbreak-related isolates were identical. By pulsed-field gel electrophoresis, all but one of the outbreak-related isolates were determined to be identical. Protein A gene typing identified numerous (11) repeat units in all outbreak-related isolates, which supports the suggestion that the outbreak strain may have been more virulent and more transmissible than other MRSA strains. Pheno- and genotyping studies underlined the value of DNA fingerprinting methods for investigation of MRSA epidemiology. Optimal discriminatory power was achieved by combining the results of four genotyping methods.

Base Sequence↗
PubMed1994

[Individual differences in solving spatial problems of the IST and IST-70 subtest on "cube problems"].

Spatial ability is one of the primary mental abilities which has been subject of many empirical studies--especially in the factor analytical research. Analysing the mental processes when solving space tasks, e. g. by means of retrospective verbal reports, two different strategies can be distinguished. The first strategy (called "holistical" strategy) can be described as a mental rotation of the given stimulus, the second one (called "analytical" strategy) is characterised by nontransformal mental processes, e. g. pattern matching processes. In order to identify those different strategies, test items are required, which have different solution probabilities when being solved with different strategies. The "cube tasks" of the IST and IST-70 by Amthauer (1953, 1970) are of this type, as Putz-Osterloh (1977) has found in an experiment. The hypothesis of individual differences in solving space tasks was tested in two different samples. First the "cube tasks" of the IST-70 were administrated to 264 applicants for the pilot job. Data analyses using the mixed-Rasch-model (Rost, 1990) confirmed the hypothesis of an "analytical" and "holistical" strategy. In the second study 2558 pupils of the 7th grade were tested with the "cube tasks" of the IST. A latent class analysis of their response patterns revealed basically the "holistical" and "analytical" strategy and, in addition, four strategies which can be explained by motivational factors.

Adolescent↗