PubMed Health⌕ Search

Biomedical subjects

P Parth

Publications and source records attributed to P Parth.

5 recordsLinked to original sources

Motor and cognitive testing of bone marrow transplant patients after chemoradiotherapy.

Assessment of cognitive and motor performance of bone marrow transplant patients prior to, during, and following intensive toxic chemoradiotherapy may provide an important adjunct to measures of physiological and medical status. The present study is an attempt to assess whether, as side-effects, these aggressive treatments result in cognitive performance deficits, and if so, whether such changes recover posttreatment. Measurement of cognitive ability in this situation presents special problems not encountered with one-time tests intended for healthy adults. Such tests must be sensitive to changes within a single individual, which emphasizes the crucial importance of high reliability, stability across repeated-measures, and resistance to confounding factors such as motivation and fatigue. The present research makes use of a microbased portable test battery developed to have reliable and sensitive tests which were adapted to study the special requirements of transplant patients who may suffer cognitive deficits as a result of treatment. The results showed slight but significant changes in neuropsychological capacity when compared to baseline levels and controls, particularly near the beginning of treatment. The sensitivity of the battery in detecting such subtle temporary changes is discussed in terms of past research showing effects of other stressors, such as stimulated high altitude and ingestion of alcohol, on these measures.

Adolescent↗

Numerosity judgments in peripheral vision: limitations of the cortical magnification hypothesis.

We studied visual numerosity judgments for linear dot arrays with regular spacing under central and off-axis observation conditions. Results indicate that an appropriate increase in stimulus size, as determined by the human cortical magnification factor, may compensate for the retinal inhomogeneity of numerosity judgments. Such a compensation, however, is no longer possible if in the numerosity judgments observers are deprived of the cue of overall dot-array length. Thus, there are aspects of the relative insensitivity of peripheral visual function that are not captured by purely geometrical considerations of the retino-cortical projection.

Adult↗

[Characterization of the effect of analgesics on the assessment of experimental pain in man. Pethidine and tramadol in a double-blind comparison].

The effect of the opioid analgesics tramadol and pethidine on experimentally induced pain was investigated in a double blind study with healthy volunteers. Using a constant current shocker, compensating the changes of the skin resistance, a constantly increasing pain stimulus was produced. Detection-, pain-, and tolerance-thresholds were assessed before and three times after intravenous injection of either pethidine (1 mg/kg bodyweight), tramadol (2 mg/kg bodyweight) or placebo (NaCl). While the two analgesics caused an increase of all three thresholds the placebo did not cause any threshold changes. The rise of the detection threshold after application of tramadol and pethidine suggests a sedation effect. However, in relation to the analgesic effect this sedation effect is stronger with tramadol than with pethidine. With the dosage used in this experiment, there is no difference in the analgesic effect of tramadol and pethidine. Compensating for intra- and interindividual changes in skin resistance, the pain stimulation method used in this study provides a good quantification of the effects of analgesics.

Adult↗