Impairment in preattentive visual processing in patients with Parkinson's disease. (57/49462)

We explored the possibility of whether preattentive visual processing is impaired in Parkinson's disease. With this aim, visual discrimination thresholds for orientation texture stimuli were determined in two separate measurement sessions in 16 patients with idiopathic Parkinson's disease. The results were compared with those of 16 control subjects age-matched and 16 young healthy volunteers. Discrimination thresholds were measured in a four-alternative spatial forced-choice paradigm, in which subjects judged the location of a target embedded in a background of distractors. Four different stimulus configurations were employed: (i) a group of vertical targets among horizontal distractors ('vertical line targets'); (ii) targets with varying levels of orientation difference on a background of spatially filtered vertically oriented noise ('Gaussian filtered noise'); (iii) one 'L' among 43 '+' signs ('texton'), all of which assess preattentive visual processing; and (iv) control condition, of one 'L' among 43 'T' distractors ('non-texton' search target), which reflects attentive visual processing. In two of the preattentive tasks (filtered noise and texton), patients with Parkinson's disease required significantly greater orientation differences and longer stimulus durations, respectively. In contrast, their performance in the vertical line target and non-texton search target was comparable to that of the matched control subjects. These differences were more pronounced in the first compared with the second session. Duration of illness and age within the patient group correlated significantly with test performance. In all conditions tested, the young control subjects performed significantly better than the more elderly control group, further indicating an effect of age on this form of visual processing. The results suggest that, in addition to the well documented impairment in retinal processing, idiopathic Parkinson's disease is associated with a deficit in preattentive cortical visual processing.  (+info)

Automated collection of quality-of-life data: a comparison of paper and computer touch-screen questionnaires. (58/49462)

PURPOSE: To evaluate alternative automated methods of collecting data on quality of life (QOL) in cancer patients. After initial evaluation of a range of technologies, we compared computer touch-screen questionnaires with paper questionnaires scanned by optical reading systems in terms of patients' acceptance, data quality, and reliability. PATIENTS AND METHODS: In a randomized cross-over trial, 149 cancer patients completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30, version 2.0 (EORTC QLQ-C30), and the Hospital Anxiety and Depression Scale (HADS) on paper and on a touch screen. In a further test-retest study, 81 patients completed the electronic version of the questionnaires twice, with a time interval of 3 hours between questionnaires. RESULTS: Fifty-two percent of the patients preferred the touch screen to paper; 24% had no preference. The quality of the data collected with the touch-screen system was good, with no missed responses. At the group level, the differences between scores obtained with the two modes of administration of the instruments were small, suggesting equivalence for most of the QOL scales, with the possible exception of the emotional, fatigue, and nausea/vomiting scales and the appetite item, where patients tended to give more positive responses on the touch screen. At the individual patient level, the agreement was good, with a kappa coefficient from 0.57 to 0.77 and percent global agreement from 61% to 97%. The electronic questionnaire had good test-retest reliability, with correlation coefficients between the two administrations from 0.78 to 0.95, kappa coefficients of agreement from 0.55 to 0.90, and percent global agreement from 56% to 100%. CONCLUSION: Computer touch-screen QOL questionnaires were well accepted by cancer patients, with good data quality and reliability.  (+info)

Quality of life in head and neck cancer patients: validation of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-H&N35. (59/49462)

PURPOSE: The aim of this study was to define the scales and test the validity, reliability, and sensitivity of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-H&N35, a questionnaire designed to assess the quality of life of head and neck (H&N) cancer patients in conjunction with the general cancer-specific EORTC QLQ-C30. PATIENTS AND METHODS: Questionnaires were given to 500 H&N cancer patients from Norway, Sweden, and the Netherlands as part of two prospective studies. The patients completed the questionnaires before, during (Norway and Sweden only), and after treatment, yielding a total of 2070 completed questionnaires. RESULTS: The compliance rate was high, and the questionnaires were well accepted by the patients. Seven scales were constructed (pain, swallowing, senses, speech, social eating, social contact, sexuality). Scales and single items were sensitive to differences between patient subgroups with relation to site, stage, or performance status. Most scales and single items were sensitive to changes, with differences of various magnitudes according to the site in question. The internal consistency, as assessed by Cronbach's alpha coefficient, varied according to assessment point and within subsamples of patients. A low overall alpha value was found for the speech and the senses scales, but values were higher in assessments of patients with laryngeal cancer and in patients with nose, sinus, and salivary gland tumors. Scales and single items in the QLQ-H&N35 seem to be more sensitive to differences between groups and changes over time than do the scales and single items in the core questionnaire. CONCLUSION: The QLQ-H&N35, in conjunction with the QLQ-C30, provides a valuable tool for the assessment of health-related quality of life in clinical studies of H&N cancer patients before, during, and after treatment with radiotherapy, surgery, or chemotherapy.  (+info)

Validity and reproducibility of a quantitative food frequency questionnaire for a cohort study in Japan. (60/49462)

BACKGROUND: A self-administered quantitative food frequency questionnaire (Qx) was developed for a population-based cohort study on cancer in Takayama, Japan. METHODS: The Qx was tested among 58 male and 59 female volunteers. Average daily nutrient intakes for the previous year calculated from the Qx were compared with those from 3-day food records and four 24-h recalls. The Qx was also validated among 37 volunteers by comparing the nutrient intakes calculated from the Qx with 12 1-day food records during a year. We also calculated the intra-class correlation coefficients for various nutrients between the Qx and the second Qx administered by the same volunteers 1 year after the first survey. RESULTS: Pearson correlation coefficients between total energy from the Qx and 3-day records were 0.38 for men and 0.25 for women and those between the Qx and 24-h recalls were 0.19 and -0.02 for men and women, respectively. Correlations between the several nutrients from the Qx and 3-day records ranged from 0.2 to 0.5 for both men and women. These correlations after energy adjustment ranged from 0.2 to 0.6 for men and from 0.1 to 0.7 for women. In general, the correlations for various nutrients between the Qx and 12 1-day records were higher than those described above. The intra-class correlation coefficients ranged from 0.46 to 0.78 in men and from 0.36 to 0.67, except for vitamin C in women. When the information on portion size was excluded, almost all of the above indices showed somewhat lower figures. CONCLUSION: These results suggest that our food frequency questionnaire with portion size information can be used to estimate nutrient intakes of each individual.  (+info)

Ketotifen and cardiovascular effects of xamoterol following single and chronic dosing in healthy volunteers. (61/49462)

AIMS: To study whether desensitization occurs after long-term administration of the 1-adrenoceptor partial agonist xamoterol and, if so, whether this can be influenced by ketotifen. METHODS: In a double-blind, randomized design 10 young, healthy males received ketotifen (2 x 1 mg day(-1) p.o.) or placebo for 3 weeks with xamoterol (2 x 200 mg day(-1) p.o.) administered concomitantly during the last 2 weeks. 'l1-adrenoceptor mediated responses were assessed as exercise-induced tachycardia and isoprenaline-induced shortening of heart rate corrected electromechanical systole (QS2c); isoprenaline-induced tachycardia was measured as a mixed beta1-/beta2-adrenoceptor-mediated effect. RESULTS: The first dose of xamoterol significantly increased resting heart rate and systolic blood pressure and significantly shortened QS2c. The last dose of xamoterol after 2 weeks of treatment still produced the same responses. Ketotifen did not influence these effects of xamoterol on resting haemodynamics. The first dose of xamoterol caused a rightward shift of the exercise- and isoprenaline-induced tachycardia (mean dose ratios+/-s.e.mean: 1.20+/-0.05 and 2.46+/-0.23) and the isoprenaline-evoked shortening of QS2c (dose ratio 3.59+/-0.68). This rightward shift was even more pronounced after 2 weeks xamoterol treatment. This additional rightward shift after 2 weeks of xamoterol was not affected by ketotifen (mean difference (95% CI) of log transformed dose ratios between placebo and ketotifen: exercise tachycardia 0.001 (-0.03; 0.04); isoprenaline tachycardia 0.03 (-0.15; 0.21); isoprenaline induced shortening of QS2c 0.13 (-0.22; 0.48)). CONCLUSIONS: In humans xamoterol is a partial beta1-adrenoceptor agonist with positive chrono- and inotropic effects at rest and antagonistic properties under conditions of beta-adrenoceptor stimulation. These effects were well maintained after chronic dosing with no signs of beta1-adrenoceptor desensitization. Ketotifen does not change the beta-adrenoceptor mediated responses of xamoterol after chronic dosing.  (+info)

Species identification and strain differentiation of dermatophyte fungi by analysis of ribosomal-DNA intergenic spacer regions. (62/49462)

Restriction fragment length polymorphisms (RFLPs) identified in the ribosomal-DNA (rDNA) repeat were used for molecular strain differentiation of the dermatophyte fungus Trichophyton rubrum. The polymorphisms were detected by hybridization of EcoRI-digested T. rubrum genomic DNAs with a probe amplified from the small-subunit (18S) rDNA and adjacent internal transcribed spacer (ITS) regions. The rDNA RFLPs mapped to the nontranscribed spacer (NTS) region of the rDNA repeat and appeared similar to those caused by short repetitive sequences in the intergenic spacers of other fungi. Fourteen individual RFLP patterns (DNA types A to N) were recognized among 50 random clinical isolates of T. rubrum. A majority of strains (19 of 50 [38%]) were characterized by one RFLP pattern (DNA type A), and four types (DNA types A to D) accounted for 78% (39 of 50) of all strains. The remaining types (DNA types E to N) were represented by one or two isolates only. A rapid and simple method was also developed for molecular species identification of dermatophyte fungi. The contiguous ITS and 5.8S rDNA regions were amplified from 17 common dermatophyte species by using the universal primers ITS 1 and ITS 4. Digestion of the amplified ITS products with the restriction endonuclease MvaI produced unique and easily identifiable fragment patterns for a majority of species. However, some closely related taxon pairs, such as T. rubrum-T. soudanense and T. quinkeanum-T. schoenlenii could not be distinguished. We conclude that RFLP analysis of the NTS and ITS intergenic regions of the rDNA repeat is a valuable technique both for molecular strain differentiation of T. rubrum and for species identification of common dermatophyte fungi.  (+info)

Evaluation of accuracy and repeatability of identification of food-borne pathogens by automated bacterial identification systems. (63/49462)

The performances of five automated microbial identification systems, relative to that of a reference identification system, for their ability to accurately and repeatedly identify six common food-borne pathogens were assessed. The systems assessed were the MicroLog system (Biolog Inc., Hayward, Calif.), the Microbial Identification System (MIS; MIDI Inc., Newark, Del.), the VITEK system (bioMerieux Vitek, Hazelwood, Mo.), the MicroScan WalkAway 40 system (Dade-MicroScan International, West Sacramento, Calif.), and the Replianalyzer system (Oxoid Inc., Nepean, Ontario, Canada). The sensitivities and specificities of these systems for the identification of food-borne isolates of Bacillus cereus, Campylobacter jejuni, Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and verotoxigenic Escherichia coli were determined with 40 reference positive isolates and 40 reference negative isolates for each pathogen. The sensitivities of these systems for the identification of these pathogens ranged from 42.5 to 100%, and the specificities of these systems for the identification of these pathogens ranged from 32.5 to 100%. Some of the systems had difficulty correctly identifying the reference isolates when the results were compared to those from the reference identification tests. The sensitivity of MIS for the identification of S. aureus, B. cereus, E. coli, and C. jejuni, for example, ranged from 47.5 to 72. 5%. The sensitivity of the Microlog system for the identification of E. coli was 72.5%, and the sensitivity of the VITEK system for the identification of B. cereus was 42.5%. The specificities of four of the five systems for the identification of all of the species tested with the available databases were greater than or equal to 97.5%; the exception was MIS for the identification of C. jejuni, which displayed a specificity of 32.5% when it was tested with reference negative isolates including Campylobacter coli and other Campylobacter species. All systems had >80% sensitivities for the identification of Salmonella species and Listeria species at the genus level. The repeatability of these systems for the identification of test isolates ranged from 30 to 100%. Not all systems included all six pathogens in their databases; thus, some species could not be tested with all systems. The choice of automated microbial identification system for the identification of a food-borne pathogen would depend on the availability of identification libraries within the systems and the performance of the systems for the identification of the pathogen.  (+info)

Use of PCR and sodium dodecyl sulfate-polyacrylamide gel electrophoresis techniques for differentiation of Prevotella intermedia sensu stricto and Prevotella nigrescens. (64/49462)

Primers were designed from 16S rRNA sequences of Prevotella intermedia sensu stricto and Prevotella nigrescens and were used to discriminate these two species by PCR. The results were compared with those from the PCR technique using primers designed from arbitrarily primed PCR products by Guillot and Mouton (E. Guillot and C. Mouton, J. Clin. Microbiol. 35:1876-1882, 1997). The specificities of both assays were studied by using P. intermedia ATCC 25611, P. nigrescens ATCC 33563, 174 clinical isolates of P. intermedia sensu lato, and 59 reference strains and 58 clinical isolates of other Prevotella species and/or common oral flora. In addition, the usefulness and reliability of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the differentiation of the two species were examined by comparing the results with those from PCR assays. The controversial lipase test for distinguishing these species was also carried out. Unambiguous differentiation was made by both PCR assays, and the results matched each other. The SDS-PAGE assay was found to misidentify a few strains tested, compared with the results of PCR assays. The lipase test was positive for both species, including the reference strains of P. intermedia and P. nigrescens. We conclude that both PCR assays are simple, rapid, reliable, and specific methods which could be used in clinical studies and that the lipase test is not valuable in the differentiation. The reliable discrimination of the two species by SDS-PAGE is questionable.  (+info)