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Biomedical subjects

A Muigg

Publications and source records attributed to A Muigg.

4 recordsLinked to original sources
PubMed1996

CAG-repeat expansion in androgen receptor in Kennedy's disease is not a loss of function mutation.

Expansion of CAG trinucleotide repeats in androgen receptor gene is present in patients with a rare X-linked inherited form of motor neuron disorder termed Kennedy's disease or spinal and bulbar muscular atrophy (SBMA). This is a late onset progressive disease often associated with mild signs of androgen insensitivity. Defects in androgen receptor (AR) action have been linked to the expansion of the CAG trinucleotide repeats and postulated to be the cause of the disease. We have identified a trinucleotide repeat of 45 in the N-terminus of the AR in two brothers with SBMA and several members in their family (range in the general population is 11-35). Treatment of the patients with androgens failed to improve their clinical symptoms and provided no hint of an anomalous function of the AR. Consistently, functional analysis of the mutant receptor showed hormone binding, transactivation and transrepression potentials identical to that of the wild-type receptor. These results together argue against SBMA being a loss of function mutation of the AR.

Androgens↗
PubMed1993

[Space medicine and life sciences in space].

The examination of pathophysiological disturbances and the process of adaptation in man during space flight is not for optimizing of the biological systems during the training of cosmonauts and astronauts for their stay in space only. These results are also important for medical application on patients. In real microgravity disturbances of motor performances, coordination of movements, accuracy of movements, muscle function as well as structural changes in muscles is found in real microgravity. Spinal reflexes and the control of vestibular system on eye movements are also afflicted. Higher brain functions, especially associative reactions, critical abilities, memory, as well as high brain function like space orientation, body scheme control, geometric and arithmetic analysis and its reproduction, at last speech production, writing and reading are decreased. Vegetative disorders, bone decalcification, primary muscular atrophy occur as well as changes in sleep--wake regulation and diminishing of vigility. Disturbances of blood and body fluid circulation and biologic radiation damage are further effects of man space flight. Several problems of space adaptation can be studied with the methods of the simulated microgravity using the dry water immersion, examination and the bed rest model in special laboratories. The routine medicine is learning from the scientific results of the research in real and simulated microgravity.

Adaptation, Physiological↗
PubMed1993

[Movement disorders in weightlessness].

The system MONIMIR has been developed to study the coordination of eye, head and arm movements as well as spinal reflexes in microgravity and was used during three spaceflights on board of the station MIR. The following investigations in the course of the experiment MONIMIR were performed: (1) slow head movements in three planes, (2.3) fast pointing movements of eyes, head and arm to acoustic and visual targets, (4) tracking movements of eyes, head and arm to visual targets, (5) head and arm movements based on short term memory and (6) patellar-tendon-reflex. In microgravity different functions and effectors showed different nature and degree of disturbance and different courses in adaptation; in most of the tests exactness and velocity of head and arm movement was decreased; head movements were more disturbed than arm movements; fast pointing movements were more severely affected than slow tracking movements which partly improved; visual controlled movements showed better adaptation as only proprioceptive controlled movements; the patellar-tendon-reflex was highly increased. Disturbances were most pronounced in the early stage of the spaceflights; at later stages most of the performances improved. Methods and results can be used not only for improvement of election and health control of cosmonauts/astronauts for future longterm space missions but also for diagnostics and research of adaptational processes in course of diseases or extreme conditions on earth.

Extraterrestrial Environment↗