Auditory event-related potentials (ERPs) were assessed in young and elderly subjects when stimulus intensity (40 vs. 60 dB SL) and standard/target tone frequency (250/500 Hz and 1000/2000 Hz) were manipulated to study the effects of these variables on the P3(00) and N1, P2 and N2 components. Auditory thresholds for each stimulus type were obtained, and the stimulus intensity was adjusted to effect perceptually equal intensities across conditions for each subject. Younger subjects demonstrated larger P3 amplitudes and shorter latencies than elderly subjects. The low frequency stimuli produced larger P3 amplitude and shorter latencies than the high frequency stimuli. Low intensity stimuli yielded somewhat smaller P3 amplitudes and longer peak latencies than high intensity stimulus tones. Although additional stimulus intensity and frequency effects were obtained for the N1, P2 and N2 components, these generally differed relatively little with subject age. The findings suggest that auditory stimulus parameters contribute to P3 measures, which are different for young compared to elderly subjects.

Acoustic Stimulation↗

PubMedDate not supplied

Non-simultaneous Interaction of exposure to noise and kanamycin intoxication in the chinchilla.

Explore the source record for details and available documents.

Animals↗

PubMedDate not supplied

Radiographic patterns of pulmonary disease.

Pulmonary radiographs are essential adjuncts to the evaluation and diagnosis of suspected pulmonary disease. In the intensive care unit, radiographs are useful to confirm correct positioning of diagnostic and therapeutic devices. Patterns seen on the radiograph may be within broadly normal limits or may be interpreted as abnormal, especially when placed in the clinical context of a specific patient's problem. The description abnormal can be related to both nonspecific and specific radiographic patterns of disease. Nonspecific radiographic patterns of disease include location of disease, temporal course of disease, pleural abnormalities, hyperinflation, extra-alveolar air, atelectasis, bronchiectasis, and vascular disease. Specific radiographic patterns of disease are discrete anatomic structures seen on a radiograph, for example, cavitary and cystic disease. The interpretation of nonspecific and specific radiographic patterns is useful in diagnosis, selection of treatment, and monitoring of the course of disease and the patient's response to treatment.

Diagnosis, Differential↗

PubMedDate not supplied

Splenectomy and antiplatelet agents in thrombotic thrombocytopenic purpura.

Ten patients with thrombotic thrombocytopenic purpura (TTP) were studied retrospectively. The male:female ratio was 2:3 and the median age was 27 years. Six patients were alive one-half to 18 years after the onset of the disease. Four of these patients underwent emergency splenectomy and received antiplatelet drugs. Of the remaining two, one responded to splenectomy and the other had received a short course of aspirin therapy. The study supports the usefulness of splenectomy and/or antiplatelet agents in the treatment of TTP.

Adolescent↗