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Biomedical subjects

K Benson

Publications and source records attributed to K Benson.

48 records · Page 3Linked to original sources
PubMed1983

Serotonin accumulation in granules of storage pool-deficient platelets of Chediak-Higashi cattle.

Platelets from cattle with the Chediak-Higashi (CH) syndrome are virtually devoid of dense granules, serotonin (5-HT), and stored ATP and ADP. The present study determined how the handling of 5-HT in normal cattle platelets differed from that in CH cattle platelets. Normal and CH platelets accumulated 5-[14C]HT to the same extent. After normal and CH platelets were incubated with 5-HT for 12 h most 5-HT is still intact, indicating that it was protected from metabolism. Part of the newly acquired 5-HT in normal and CH platelets was in a pool that was rapidly released by 5 U/ml of thrombin, suggesting that 5-HT was, in part, within granules. Subcellular fractionation studies showed that, whereas most of the newly acquired 5-HT in normal platelets was located in the dense granule fractions, about one fourth was found in the lighter granule fraction that was enriched in alpha-granules. The dense granule fraction was virtually absent in CH platelets, and most of the granule 5-HT was associated with the lighter granule fraction. The mixed granule fraction from CH platelets accumulated 5-HT but the uptake was about 10% of that from normal platelets. Unlike normal granules the uptake of 5-HT by CH granules was only slightly inhibited by reserpine but was reversed by NH4Cl and nigericin treatment.

Animals↗
PubMed1982

Ultrastructure of resting and activated storage pool deficient platelets from animals with the Chédiak-Higashi syndrome.

The ultrastructural of platelets from Chédiak-Higashi (CH) and normal cattle, mink, and cats at rest was studied. Platelets from CH animals had a virtual absence of platelet dense granules. Alpha granules, amorphous membrane-surrounded structures, mitochondria, and microtubules of CH bovine platelets were similar in number and appearance to those in normal bovine platelets. Giant CH granules, present in other cells and considered diagnostic of the syndrome, could not be identified in platelets from CH animals. The open canalicular system and dense tubule system were not readily identifiable in resting bovine platelets. The ultrastructure of normal and CH cattle platelets was evaluated at various stages of ADP-induced aggregation. After platelets changed shape during the first phase of aggregation, the ultrastructural appearance of CH platelets was similar to that of normal platelets. The CH platelets composing the aggregates during irreversible aggregation did not appear as activated as did normal platelets, even though the aggregation tracings were similar. Normal and CH cattle platelets treated with thrombin appeared morphologically similar and were characterized by centrifugal movement of granules.

Adenosine Diphosphate↗
PubMed1979

Phasic events of REM sleep: phenomenology of middle ear muscle activity and periorbital integrated potentials in the same normal population.

Both periorbital integrated potentials (PIPs) and middle ear muscle activity (MEMAs) were recorded in a sample of normal male veterans. Activity measures were constructed for each REM period and for the 10 min preceding and following each REM period. PIPs and MEMAs displayed high levels of internight reliability. PIPs were more abundant than MEMAs; in REM the average PIP rate was almost 8 times the average MEMA rate. Within REM, the proportion of MEMAs and PIPs with concurrent eye movement activity was very similar, 66 and 70%, respectively. Both PIPs and MEMAs had higher rates within REM than within NREM. NREM PIP activity was similar both before and after the REM period, whereas NREM MEMA activity was higher before the REM period than after the REM period. Within REM, the distribution of PIPs and MEMAs was similar for REM periods exceeding 30 min. Within-night trends could nor be established for MEMAs due to limitations of the recording technique; PIPs, however, were generally highest in the middle of the night but still higher at the end of the night than at the beginning. Correlations with psychometric test data showed PIP rate in REM to be related to the psychoticism scale of the Minnesota Multiphasic Personality Inventory and MEMA rate in REM to be inversely related to the Barron Ego Strength scale. No associations were found between the psychometric data and measures of PIP and MEMA leakage from REM into NREM. The potential for pathological intrusion of REM phasic events into the waking stage might be conceptualized in terms of a general ungating of activity with PIP and MEMA rates increasing in both NREM and REM alike.

Adult↗
PubMed1978

REM sleep time and digit span impairment in alcoholics.

In a group of 20 abstinent alcoholics, the amount of REM sleep was correlated with the degree of Digit Span scatter from the modified verbal mean of the WAIS. The Digits Backward component was more strongly related to REM time than was the Digits Forward component, suggesting an association between reduced REM sleep time and short-term memory impairment.

Adult↗
PubMedDate not supplied

Development of a community nurse-led continence service.

Extrapolations from prevalence studies suggest that on average 56,000 adults experience urinary incontinence in Glasgow, a third of whom will have been incontinent during the last week. A review by a multidisciplinary health gain commissioning team concluded that existing continence services in Glasgow had developed opportunistically and that problems exist, e.g. prescription of products without full assessment of continence problems. In response to this situation, a new community nurse-led continence service was introduced in 1995. This article describes the development and evaluation of this new service. For the past 3 years the service has employed five staff nurses and a physiotherapist. The team is solely employed to promote continence. It carries out assessments both in nursing and residential homes and community clinics. The planned evaluation will assess the effectiveness of this team in promoting continence and the future demand for continence nurse-led services.

Adult↗