Purpose: Correct serotype identification of Streptococcus pneumoniae (pneumococcus) is important for monitoring disease epidemiology and assessing the impacts of pneumococcal vaccines. Furthermore, correct identification and differentiation of the pathogenic S. pneumoniae from closely related commensal species of the mitis group of the genus Streptococcus are essential for correct serotype identification.
View Article and Find Full Text PDFEvent-related brain potentials (ERPs) and magnetic fields (ERFs) were used to compare brain activity associated with selective attention to sound location or pitch in humans. Sixteen healthy adults participated in the ERP experiment, and 11 adults in the ERF experiment. In different conditions, the participants focused their attention on a designated sound location or pitch, or pictures presented on a screen, in order to detect target sounds or pictures among the attended stimuli.
View Article and Find Full Text PDFWe studied orienting and maintenance of spatial attention in audition and vision. Functional magnetic resonance imaging (fMRI) in nine healthy subjects revealed activations in the same superior and inferior parietal, and posterior prefrontal areas in the auditory and visual orienting tasks when these tasks were compared with the corresponding maintenance tasks. Attention-related activations in the thalamus and cerebellum were observed during the auditory orienting and maintenance tasks and during the visual orienting task.
View Article and Find Full Text PDFWe examined the effects of orienting and maintenance of attention on performance and event-related brain potentials (ERPs) in audition and vision. Our subjects selectively attended to sounds or pictures in one location (Maintenance of attention) or alternated the focus of their auditory or visual attention between left and right locations (Orienting of attention) in order to detect and press a response button to infrequent targets among the attended stimuli. Reaction times were longer in the Auditory Orienting condition and hit rates were lower and false alarm rates higher in the Visual Orienting condition than in the corresponding Maintenance conditions.
View Article and Find Full Text PDFWe used behavioral measures and functional magnetic resonance imaging (fMRI) to study the effects of parametrically varied task-irrelevant pitch changes in attended sounds on loudness-discrimination performance and brain activity in cortical surface maps. Ten subjects discriminated tone loudness in sequences that also included infrequent task-irrelevant pitch changes. Consistent with results of previous studies, the task-irrelevant pitch changes impaired performance in the loudness discrimination task.
View Article and Find Full Text PDFCoherent perception of objects in our environment often requires perceptual integration of auditory and visual information. Recent behavioral data suggest that audiovisual integration depends on attention. The current study investigated the neural basis of audiovisual integration using 3-Tesla functional magnetic resonance imaging (fMRI) in 12 healthy volunteers during attention to auditory or visual features, or audiovisual feature combinations of abstract stimuli (simultaneous harmonic sounds and colored circles).
View Article and Find Full Text PDFWe used 3-T functional magnetic resonance imaging to compare the brain mechanisms underlying selective attention to sound location and pitch. In different tasks, the subjects (N = 10) attended to a designated sound location or pitch or to pictures presented on the screen. In the Attend Location conditions, the sound location varied randomly (left or right), while the pitch was kept constant (high or low).
View Article and Find Full Text PDFWe used behavioral and event-related potential (ERP) measures to study the neural mechanisms of involuntary attention switching to changes in unattended sounds. Our subjects discriminated two equiprobable sounds differing in frequency (fundamental frequency 186 or 196 Hz) while task-irrelevant intensity decrements or increments (-3, -6, -9, +3, +6, or +9 dB, standard intensity 60 dB HL) infrequently occurred in the same sounds. In line with the results of previous studies, discrimination performance deteriorated with increasing magnitude of the task-irrelevant intensity change.
View Article and Find Full Text PDFFunctional magnetic resonance imaging (fMRI) was used to examine the processing of infrequent changes occurring in an unattended sound sequence. In event-related brain potentials (ERPs), such sound changes typically elicit several responses, including an enhanced N1, the mismatch negativity (MMN), and the P3a. In the present study, subjects were presented with a repeating sound of 75 ms in duration, which was occasionally replaced, in separate blocks, by a 15-ms, 25-ms, or 35-ms sound (large, medium, and small change, respectively).
View Article and Find Full Text PDFWe studied the effects of sound presentation rate and attention on auditory supratemporal cortex (STC) activation in 12 healthy adults using functional magnetic resonance imaging (fMRI) at 3 T. The sounds (200 ms in duration) were presented at steady rates of 0.5, 1, 1.
View Article and Find Full Text PDFThe processing of abstract stimulus features in the human brain was studied by presenting the subjects with frequent standard tone pairs and infrequent deviant tone pairs. Both pairs varied randomly over a wide frequency and/or intensity range, there being no physically constant standard stimulus. The common feature of the standard pairs was the direction of change within the pair, e.
View Article and Find Full Text PDFNeuropeptides act within the pituitary as autocrine or paracrine factors, modulating the synthesis and release of primary pituitary hormones, and possibly regulating cell proliferation and/or plasticity. Manipulation of the endocrine status of rats produces dramatic long-term changes in the pituitary expression of several peptides, including the neuropeptides galanin and vasoactive intestinal peptide (VIP). Whether or not these changes are caused indirectly by hypothalamic factors, or by hormone actions directly in the pituitary, has been only partially addressed.
View Article and Find Full Text PDFIn four previous case-control studies we have shown an association between exposure to phenoxyacetic acids or chlorophenols and soft-tissue sarcoma (STS). These chemicals are contaminated by dioxins and dibenzofurans, some of which are known carcinogens in experimental animals. In a meta-analysis of our four studies we studied such exposure including the relation to tumour localization and histopathological type of STS.
View Article and Find Full Text PDFThis article presents the joint results of two Swedish case-control studies regarding occupational exposure and female papillary thyroid cancer. Questionnaires inquiring about lifetime occupations and specific occupational exposures were mailed to cases and controls, aged 20 to 70 years. Some 185 female papillary or mixed cancer cases and 426 female controls were included in the analysis.
View Article and Find Full Text PDFPlasma selenium and glutathione peroxidase in erythrocytes were analysed in a case-control study encompassing 164 cases with prostate cancer and 152 controls with benign prostate hyperplasia. Plasma selenium levels were divided into three groups; I > 1.17, II 1.
View Article and Find Full Text PDFAn association between female sex hormones and thyroid cancer has been suggested, but the only well-established risk factor is ionizing radiation. This case-control study was designed to evaluate the association between different aetiological factors and thyroid cancer and encompassed 180 cases aged 20-70 years at the time of diagnosis in 1980-89, and 360 controls. The response rate was 92%.
View Article and Find Full Text PDFResults on 105 cases with histopathologically confirmed non-Hodgkin's lymphoma (NHL) and 335 controls from a previously published case-control study on malignant lymphoma are presented together with some extended analyses. No occupation was a risk factor for NHL. Exposure to phenoxyacetic acids yielded, in the univariate analysis, an odds ratio of 5.
View Article and Find Full Text PDFThe aim of this study was to investigate exposure to diagnostic and therapeutic ionizing radiation as a risk factor for thyroid cancer. This case-control study encompassed 180 women and men with thyroid cancer, aged 20-70 years at the time of diagnoses in 1980-89. From the National Population Registry 360 controls were selected.
View Article and Find Full Text PDFEur J Cancer Prev
January 1994
Levels (microgram/g dry weight) of cadmium (Cd), zinc (Zn) and copper (Cu) were determined in kidneys with renal cell carcinoma from 20 male and 11 female patients. Autopsied kidneys from nine males and eight females who had died of nonmalignant diseases were used as controls. The mean levels in cortex of Cd was in cases 103.
View Article and Find Full Text PDFEur J Cancer Prev
July 1993
A case-control study on thyroid cancer concerning 180 cases and 360 controls aged 20-70 years at diagnosis was performed. Both females and males were included. Of the cases, 63% had had papillary thyroid cancer.
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