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Biomedical subjects

L Fischer

Publications and source records attributed to L Fischer.

At least 145 records · Page 8Linked to original sources
PubMed1983

Modulation of synaptic transmission and excitation-contraction coupling in the opener muscle of the crayfish, Astacus leptodactylus, by 5-hydroxytryptamine and octopamine.

The modulatory actions of 5-hydroxytryptamine (5-HT) and octopamine (OA) were investigated in the opener nerve-muscle preparation of the crayfish, Astacus leptodactylus. Membrane resistance and resting potential were unaltered by 5-HT and OA at concentrations up to 2.5 X 10(-5) M; but EPSP-amplitudes were increased, up to 3-fold by OA and up to 18-fold by 5-HT. The lowest effective concentration was 2.5 X 10(-9) M; a maximal effect was produced at 2.5 X 10(-6) M. The effect was reversible only after prolonged washing. The enhancement of EPSPs by 5-HT or OA is due to an increased amplitude of the synaptic current; the current duration is not altered. The facilitation ratio (ratio of amplitudes of a pair of EPSPs) is not significantly affected by 5-HT or OA despite the often enormous increase of the absolute EPSP-amplitudes. The modulatory action also affects the excitation-contraction (e-c) coupling process: the effectiveness of e-c coupling was increased 7.4-fold by 5-HT (2.5 X 10(-6) M) and 18.7-fold by OA (5 X 10(-6) M). The threshold potential of e-c coupling was not affected.

Animals↗
PubMed1982

Between-minute stability in habituated human skill with modestly lowered blood glucose.

Modestly lowered blood glucose (G) occurs with fasting and exercise, increasing variability in forces applied during repetitions of an habituated cycling task. Its effect was studied on stability of the movement cycle pattern of forces from minute to minute. Forces applied at 26 positions in the movement cycle were correlated with each other over 20 one minute samples. Six young men worked (a) 3 hr post-prandial, or as (a) but terminated by feeding 100 g (G) slurry (b) immediately before or (c) 30 minutes before exercise. For each sample, data were averaged over subjects, feet, exercise loads (100 W; 150 W) and 40 movement cycles. Over all conditions together, the movement cycle forces were strongly patterned, implying control by pre-set neural programs. Evoked depressions of blood G below fasting coincided with significant reduction in this patterning. It is suggested that in neural control circuits with modestly depressed blood G, there may be increased sensitivity to feedback over movement cycles.

Adult↗
PubMed1982

Postsynaptic potential and postsynaptic current in muscle fibres with large time-constant. EPSP amplitude is independent of membrane resistance.

1. Equations have been developed for a computer programmed calculation of synaptic current from synaptic potentials (epsps). 2. The method permits separation of presynaptic and postsynaptic effects in experiments involving drugs which affect synaptic transmission. It is particularly applicable where the postsynaptic cells are large as in the case of commonly employed crustacean muscle fibres. 3. Contrary to a widely held view the theoretical approach used predicts that epsp-amplitude is relatively independent of membrane resistance. 4. Confirmation is provided by experiments involving the application of barium which increases, and of GABA which decreases membrane resistance.

Animals↗
PubMed1981

Psychiatric aftercare: identified needs versus referral patterns.

Although psychiatric aftercare has received increased attention, little is known about patients' needs for community resources or about predischarge referral patterns. The authors interviewed hospital staff about needs and referrals for each of 747 patients about to be discharged. Nearly all patients had needs in the medical/therapeutic area and most received referrals. In three other nonmedical aftercare areas needs were identified for a much lower percentage of patients, and identified need was two to three times greater than referrals made. The authors discuss the implications of these findings for the provision of aftercare services.

Adult↗
PubMed1980

An agency model for developing and coordinating psychiatric aftercare.

The development of coordinated systems for delivery of aftercare services to psychiatric patients has lagged far behind the theoretical emphasis on community maintenance. From a collaboration of 29 treatment and rehabilitation facilities, an independent agency was established to improve aftercare services in Metropolitan Toronto. Known as Community Resources Consultants, the agency was designed to facilitate and rationalize the use of existing services, to identify gaps in service, to initiate or cooperate in the development of new services, and to involve hospital and community service personnel in raising the level of expertise in the provision of aftercare. Formal and informal assessments indicate that CRC has had a positive effect on the provision of aftercare services and on professionals' level of awareness of aftercare priorities.

Adult↗
PubMed1979

The ANA position.

Explore the source record for details and available documents.

American Nurses' Association↗
PubMed1978

[The concept of the subculture of the aging reconsidered (author's transl)].

This article reviews the concept of a "subculture of aging" (Rose 1965) and describes the conditions necessary for the development of a subculture. The discussion proves this concept to be ambivalent. On the one hand the term "subculture of aging" covers the acquisition of new age-appropriate roles, on the other hand it stresses segregation of old people from society as a whole. The results of some preliminary studies suggest that intensified age-homogenous interaction may indeed facilitate new patterns of behaviour among older people although they are relatively well integrated. Instead of the label "subculture" the more appropriate term of "partial culture" is proposed.

Aged↗
PubMed1975

[Intra-osseous vascularization of the astragalus].

Using micro-angiography and Spalteholz's technic on twenty cadaveric feet. The arterial vascularisation of talus is described. They emphasize the importance of the internal arterial pedicle coming from the arteria tibialis posterior and entering the corpus tali through its internal wall.

Angiography↗