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Biomedical subjects

S Naumann

Publications and source records attributed to S Naumann.

At least 37 records · Page 2Linked to original sources

Development of an integrated wheelchair tray system for augmentative communication.

This paper describes the development of a wheelchair tray system for persons with physical disabilities who require an augmentative communication system. The tray system offers advantages over existing systems by providing a convenient anterior/posterior tilt feature, a means for stowing the tray when not in use, and a method of accommodating communication systems and powered wheelchair controls. Caregivers of seven subjects fitted with the prototype system assessed its performance through the completion of questionnaires provided at the end of 6-week field trials. The technical performance of the systems was also monitored. The prototype system was favorably received by six participants. Several recommendations are made to further increase consumer acceptance of the final tray design.

Adolescent↗

Rehabilitation engineering in pediatrics.

Applications of science and technology in the (re)habilitation of children and young adults can have dramatic, positive influences on their lives. Prosthetics, orthotics, mobility, postural support and seating, communication and education are responsibilities of the rehabilitation engineer. A holistic approach in meeting individual needs for technology is essential. The concerted rehabilitation engineering programme at The Hugh MacMillan Rehabilitation Centre supports service programmes with relevant research and development work.

Biomedical Engineering↗

A three-dimensional kinematic and dynamic model of the lower limb.

A model describing the kinematics and dynamics of the lower limb is presented. The lower limb is modeled as a sequence of four rigid links connected by three universal rotary joints representing the hip, knee and ankle joints. Each joint is modeled as a sequence of three single axis rotational joints thus ascribing to the lower limb a total of 12 degrees of freedom. A method is described to measure the gait variables so that all nine angles can be computed based on the positions of nine markers placed on the subject during a gait study. The gait variables are then used in an iterative Newton-Euler formulation to compute the moments exerted about the axes of each joint during gait.

Adult↗

Humoral antibody response of rabbits to experimental infection with Encephalitozoon cuniculi.

Six female rabbits (Oryctolagus cuniculus) were experimentally infected intravenously with approximately 1.5 X 10(7) live spores of Encephalitozoon cuniculi. Head tilt was observed as the single clinical sign in only one of the six animals. Antibody response was registered over 68 days postinfection using the indirect immunofluorescence test (IFT) for IgM and IgG, and the carbon immunoassay (CIA). IgG titers reached a level of 160-2560 after a latent phase of 13-28 days, followed by a 2-4 week relatively steep increase. The IgM seroconversion was faster than that of IgG and occurred at the beginning of the antibody response. Thus, simultaneous detection of both IgM and IgG allowed the infection to be identified as recent. Long, short, and episodic antibody responses could be distinguished: the IgG titer continued to increase on Day 68 in one animal (long response) and began to decrease between Days 45 and 63 in three other animals (short response). In two additional animals the seroconversion was very short, occurring between Days 13 and 41, and 28 and 52, respectively (episodic response). The CIA proved to be specific, reliable, and simple to perform; titers were slightly higher than in the IFT. Parasite pseudocysts were detected scattered throughout the brain on Day 68 in four of the six rabbits. The persistence of antigen in the brain did not correlate with antibody response, which in most cases was shorter.

Animals↗

A three-quarter type below-elbow socket for myoelectric prostheses.

The Muenster and Northwestern sockets have become universally prescribed for below-elbow amputees with myoelectric prostheses. The most attractive feature of these sockets is that they are self-suspending, thereby obviating the need for a harness. The sockets are designed to encompass the patient's whole elbow. Because of the intimate fit, heat build-up inside the socket is a problem. Patients with myoelectric prostheses are denied the benefit of a stump sock. Ventilation inside the socket is almost zero and excessive perspiration occurs. This leads to maceration and skin problems which negatively affect control, comfort and wearing time. This paper reports on a technique whereby the problem of no ventilation is overcome through the removal of the proximal-posterior quadrant of the socket.

Adult↗

Effect of ankle position on isometric quadriceps strengthening.

A prospective study of 20 normal subjects was undertaken to determine the effect of three ankle positions (active dorsiflexion, active plantar flexion, natural or rest position) on comfort and facilitation of quadriceps contraction in isometric strengthening in a supine position with the hip and knee fully extended. Surface EMG activity was found to be greatest for the vastus lateralis followed by the vastus medialis and least for the rectus femoris. Equal facilitation was apparent with either active ankle dorsiflexion or plantar flexion. Both were superior to the natural (rest) position. In situations where isometric quadriceps exercises are required, the authors recommend either active ankle dorsiflexion or plantar flexion to facilitate quadriceps strengthening. The choice between the two positions should be based on patient comfort.

Adult↗

Head tilt in rabbits caused by pasteurellosis and encephalitozoonosis.

Rabbits (Oryctolagus cuniculus) of non-dwarf (Group A) and dwarf (Group B) strains showing a common clinical sign of head tilt (torticollis) were examined. With 1 exception, all rabbits of group A had otitis and empyema of either one or both middle ears. Pasteurella multocida was isolated from pus and from the nose of all but 1 of these rabbits, and on occasion was also isolated from the brain. By contrast in all dwarf rabbits the presence of the protozoan Encephalitozoon cuniculi was confirmed both histologically and serologically. This parasite did not affect the ears of the animals but rather the central nervous system. We assume that the different exposure to both agents, rather than the degree of susceptibility, was responsible for the differences found between the 2 types of rabbits.

Animals↗

Experimental viral pneumonia in guinea pigs: an ultrastructural study.

Homogenized lung tissue was used to experimentally reproduce lethal viral pneumonia in guinea pigs. The resultant lesions corresponded with those of the spontaneous disease. Pneumonia with necrotic bronchiolar epithelium accompanied by basophilic intranuclear inclusion bodies was the primary finding. With transmission electron microscopy, numerous viral particles were found--mainly within the nucleus of pulmonary epithelial cells but also within the cytoplasm and in extracellular space. The appearance of viral particles, in particular their paracrystalline and crystalline deposition within the nucleus, indicates that our experimentally induced pneumonia was caused by an adenovirus.

Adenoviridae Infections↗

Adenovirus pneumonia in guineapigs: an experimental reproduction of the disease.

The recently described virus-induced pneumonia in guineapigs (Naumann et al., 1981) was experimentally reproducible in newborn animals, though not in preadult animals. Baby hamsters and newborn rats were also not susceptible to infection. 10 of 11 infected newborn guineapigs developed pathological changes identical with those found in spontaneous cases. The incubation period was from 5 to 10 days. The agent could not be cultivated in vitro, and therefore no applicable serological tests could be established. The morphology of the virus, its intranuclear location, the course of the disease and the histopathological and ultrastructural changes strongly suggest that the virus is an adenovirus specific for guineapigs. The virus did not cross-react with human or fowl adenoviruses. It was ether resistant and non-oncogenic in baby rats and hamsters. During a 5-year period we registered a total of 51 spontaneous death cases diagnosed as adenovirus pneumonia in our experimental guineapigs, 4 from own breeding colony.

Adenoviridae Infections↗

Urethral plug--a new secondary male sex characteristic in rat and other rodents.

The plug is an eosinophilic mass, partly homogenous and partly porous, filling the proximal urethra in rats and occasionally extending into the bladder. Its average weight in 131 adult rats was 0.063 g. These plugs are normally present in the urethra of adult male rats, and this seems to be the case for all laboratory Muridae and Cavidae. The absence of a plug in an adult male may be a sign of abnormality associated with failing health. There is an interesting similarity between the amino acid composition of the content of seminal vesicles, that of the urethral plug, and that of the copulatory vaginal plug in female rodents.

Animals↗

Lethal pneumonia in guinea pigs associated with a virus.

No bacteria were observed in an epizootic of lethal pneumonia in guinea pigs. Necrotic bronchitis and bronchiolitis with basophilic intranuclear inclusion bodies in bronchial epithelial cells were characteristic. Although adenovirus infection of guinea pigs has not previously been reported, histological findings paralleled those found in adenovirus infections of other animals including man. Virus particles found by electron-microscopical examination of the lung tissue closely resembled adenoviruses. The disease seemed to have a low contagiousness, a low morbidity (about 0.7%), but an acute course and a high mortality (100%).

Adenoviridae↗