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Biomedical subjects

S Peters

Publications and source records attributed to S Peters.

At least 271 records · Page 15Linked to original sources
PubMed1982

Developmental overproduction and selective attrition: new processes in the epigenesis of birdsong.

All phases of song development from infancy to adulthood were studied intensively in a group of laboratory-reared birds. Male swamp sparrows, Melospiza georgiana, trained with tape-recorded songs in infancy, developed song some 8 months later, averaging 2.2 song types per bird. Analysis of the intermediate stage of plastic song revealed that the birds generated 4 to 5 times more song material than was needed for the species-specific song repertoire. The excess was discarded at the time of full song crystallization. Indications that the attrition process is selective include tendencies to retain imitated rather than nonimitated elements, and the rejection of heterospecific elements. Attrition may also be influenced by vocal stimulation at the time of song crystallization, providing an opportunity for behavioral adjustment even though new themes can no longer be learned. Attrition has been described in the transition in human infants from babbling to speech.

Animals↗
PubMed1982

[Examinations by psychological tests in basic stages and pure residual syndromes of schizophrenic diseases (author's transl)].

Three groups of schizophrenic diseases which cannot be differentiated with regard to psychopathological cross-section syndromes were investigated by psychological tests: one group (22 cases) of reversible postpsychotic basic stages and two groups of pure residual syndromes with an average duration of disease of 9.3 years (20 cases) and 17.5 years (21 cases). All three groups revealed findings deviating significantly from the norm. The pathological values were most marked in the performance scale of HAWIE (Hamburg-WAIS), which in all groups showed a significant lowering of performance compared with verbal scale (which corresponds approximately to the premorbid intelligence level), in "KVT" and in measures of sensory-motor reaction time by "Wiener Reaktionsgerät", less in "Benton test" and in examination with "Schreibdruckwaage". Reversible postpsychotic asthenic basic stages could not be significantly differentiated in psychological tests from pure residual syndromes which were comparable with regard to sex and age at the onset of the disease and--in the pure residues group of 1980--with regard to age and school success. The decrease of performance in the reaction test, in the concentration test of Abels, and in the averbal part of HAWIE correlated with symptoms and factors which were found with the help of "Frankfurter Beschwerdefragebogen" in the same patients. This positive correlation was more distinct in the reversible postpsychotic basic stages than in pure residues. The findings support the global hypothesis that the deficiencies of schizophrenic stages with a component of reversible or irreversible pure potential reduction are based on disturbances of perception and interpretation of information. Also that there are no fundamental differences between cerebro-organic or psychosyndromes of schizophrenic diseases determined by the dynamic and cognitive disorders of pure deficiency.

Adult↗
PubMed1982

Partial purification and characterization of hemolysin from a psychrotrophic kanagawa-positive marine Vibrio.

Psychrotrophic Kanagawa-positive marine vibrios were isolated from soft-shelled clams (Mya arenaria) collected in Yaquina Bay, Oreg. The 235 vibrio isolates obtained were screened for Gram reaction and morphology, Kanagawa reaction on Wagastsuma agar, and response to selected biochemical tests. The vibrio selected for further study was grown in broth, and the hemolysin was precipitated from a cleared supernatant with solid ammonium sulfate. The hemolytic substance was partially purified by DEAE-cellulose and Sephadex G-100 column chromatography. The hemolysin contained protein essential for activity, was thermolabile, and was more active against rabbit erythrocytes at 37 degrees C than at lower temperatures. The molecular weight was estimated at 55,000 by using a Sephadex G-100 column. Hemolytic activity was partially inactivated by gangliosides and lowered against horse erythrocytes. The hemolysin did not react with antibody prepared against vibriolysin from Vibrio parahaemolyticus WP-1 by the Ouchterlony method. The hemolysin was high in aspartic and glutamic acids and low in arginine and histidine. Electrophoresis on a sodium dodecyl sulfate-polyacrylamide gel gave three major bands. The hemolysin from a psychrotrophic vibrio and the hemolytic exotoxin of V. parahaemolyticus had some similar and dissimilar characteristics. The possibility that a Vibrio sp. other than V. parahaemolyticus might serve as the reservoir for the Kanagawa phenotype is discussed.

Journal Article↗
PubMed1980

Serotonin and pulmonary hypertension in human septic ARDS.

Pulmonary hypertension gives an indication of poor prognosis in adult respiratory distress syndrome (ARDS) complicating sepsis. In this study, we examined the role of the platelet and the vasoactive amine, serontonin, in pulmonary hypertension accompanying septic ARDS. The lack of any significant difference in platelet number (delta + 3.9 +/- 8.4, X 10(3)/mm3) or serum serotonin (delta - 0.03 +/- 0.06 nm/mm3) across the pulmonary vascular bed (pulmonary artery minus pulmonary vein), would suggest that platelet sequestration and/or release of serotonin is not a major factor in septic ARDS. However, we did note a direct positive relationship between serum serotonin (Ss) and the pulmonary artery diastolic minus pulmonary capillary wedge pressure (PAd-PCWP) gradient (r = 0.64, p < 0.01) implying that serum serotonin may be related to pulmonary hypertension in septic ARDS.

Blood Platelets↗
PubMed1980

[Evaluation of a simple nursing load score (author's transl)].

It becomes increasingly important to assess the nursing load in geriatric medicine in order to gauge the needs of the geriatric patients. To this purpose a simple system is needs. We evaluated a Swedish (1) scoring system by comparing thr nursing load in 3 geriatric wards (with a total of 171 patients 1977 and 160 patients 1978) at the end of the calender year. The nursing load was similarly distributed in each ward at the beginning and the end of the observation period. Marked differences was observed between patients who were discharged, who remained in the clinic or who died within the one year period. Of particular importance is the finding that mental deterioration correlated significantly (p smaller than 0.001) with increased overall nursing requirements. This points to the great importance of psychogeriatric diseases for future demand in nursing care.

Aged↗