Search PubMed⌕ Search

Biomedical subjects

G Fischer

Publications and source records attributed to G Fischer.

At least 541 records · Page 30Linked to original sources
PubMed1982

Civil liability in the field of biomedical engineering and medical physics.

The article deals with the protection the law provides against risks emanating from the use of biomedical equipment. After a brief discussion of public safety regulations, it turns to civil liability for damages involving patients or other persons. Doctors and hospitals using or failing to use biomedical equipment can be held liable for negligent conduct only. The standards of care to be observed in biomedical engineering are thus explained, as is the correct use of the equipment, the safety precautions to be taken, and the expertise of the operator. Another very important subject of the article is the liability of the manufacturers of biomedical equipment. Finally, the extremely difficult question is discussed as to what extent doctors and hospitals are obliged to acquire new but very expensive equipment, and what are the economic limits of this obligation.

Biomedical Engineering↗
PubMed1982

Dimyelia, diplomyelia, and diastematomyelia.

Four types of rare human spinal cord duplications are reported. (1) Dimyelia, a complete duplication of the spinal cord, was observed in a female stillborn dicephalus dibrachius. Histologically the two spinal cords showed symmetric medial hemihypoplasia that included the roots. (2) Diplomyelia, an isolated accessory spinal cord without roots at the ventral lumbosacral level, was observed in a newborn female with a cardiovascular malformation. (3) Complex diastematomyelia: a 9-day-old boy had Arnold-Chiari malformation and an additional diastematomyelia with thoracic meningomyelocele; the left branch of the cord showed further complex multifurcations. (4) Typical diastematomyelia was observed in a stillborn female, born to an adolescent mother at 34 weeks of gestation. The term dimyelia is used to express the condition of total duplication of the spinal cord, by analogy to the term dicephalus in the case of duplicitas. Diastematomyelia means a lateral bifurcation of the spinal cord, independent of whether or not the branches show completely differentiated cord structures with four columns and segmental roots. The term diplomyelia, on the other hand, should be limited to cases of an isolated accessory spinal cord, ventral or dorsal to the normal cord.

Abnormalities, Multiple↗
PubMed1982

[Early stage of a cloverleaf skull malformation].

Cloverleaf skull anomaly was diagnosed sonographically and in the fetogram, together with concomitant chondrodystrophy. This resulted in an indication for intentional abortion in the 29th week. Consequently, this rare form of skull monstrosity could be examined pathologico-anatomically for the first time in a very early stage of foetal development. Contrary to the widely held opinion that the reason for such hideous malformation is a hydrocephalus internus due to a deformation of the skull base, we found a practically negligible hydrocephalus, although the cloverleaf skull had already developed in a very marked manner. Hence, this case contradicts the generally adopted formal pathogenetic interpretation of cloverleaf skull monstrosity.

Abnormalities, Multiple↗
PubMed1981

Erythrocyte filtration and smoking.

Erythrocyte filterability may be influenced by 'acute' smoking with subsequent changes of RBC filterability and by chronic inhalation of cigarette smoke which may lead to chronic alterations. To evaluate chronic alterations of RBC deformability we compared the erythrocyte filtration rates of 60 young, healthy chronic smokers (30 female, 30 male) with those of 60 young, healthy non-smokers (again 30 female and 30 male). The comparison showed a higher filtration rate in the male non-smokers group than in the group of the male smokers, the difference however was not statistically significant. Female smokers and non-smokers did not show any noticeable difference in their RBC filtration rates.

Adolescent↗
PubMed1981

Cerebroside sulfatase activator deficiency induced metachromatic leukodystrophy.

Two siblings of consanguineous parents had presented with a variety of findings indicative of juvenile metachromatic leukodystrophy (MLD). However, instead of the expected profound deficiency of arylsulfatase A (ARS A), their enzyme levels were about half-normal, and enzyme from fibroblasts had properties identical with the properties of enzyme from normal fibroblasts. Nevertheless, the hydrolysis of cerebroside sulfate by growing fibroblasts was markedly attenuated. Supplementation of the fibroblasts with cerebroside sulfatase activator normalized the response in the loading test. These results imply that the fibroblasts, and by extension the patients, are deficient in activator. Although the defective catabolism of cerebroside sulfate and the clinical manifestations in these patients mimic MLD, the molecular basis is distinct from the classical forms of the disorder.

Cerebroside-Sulfatase↗
PubMed1981

[Pulmonary damage caused by cytostatics and paraquat (author's transl)].

Pulmonary damage induced by cytostatics is a rare, although clinically important complication in the chemotherapy of tumours. Early recognition of this partly toxically and partly hypersensitively conditioned processes is of great prognostic importance, since in many cases the unchecked progress of the damage, eventually resulting in pulmonary fibrosis with respiratory insufficiency, can be prevent only by discontinuing the treatment well in time. Examinations of the pulmonary function enable a very early detection of functional disturbances in a lung which has been damaged by cytostatics. Since even the later roentgenological findings are non-specific, final confirmation of the diagnosis is possible by pulmonary biopsy only. Lungs damaged by cytostatics show histologically characteristic patterns, which, however, are non-specific and can become manifest in the same manner, inter alia, in shock and in intoxication by paraquat, since the basic principle of damage underlying these processes is very similar.

Antineoplastic Agents↗
PubMed1981

[Inhibition of stress reactions by magnesium. Beneficial effects of parenteral magnesium therapy on the development of stress ulcers in rats (author's transl)].

In rats fasted for 24 h with drinking-water ad libitum, gastric ulcers were produced by immobilization for 18 h. Subcutaneous injections of magnesium-aspartate-hydrochloride (Maganesiocard) induced pronounced hypermagnesemia after about 1, 7 and 13 h. Macroscopical estimation of gastric lesions as well as the quantitative microscopical examination performed under blind conditions and considering both surface and depth of the ulcers revealed significant protective effects of the magnesium therapy.

Animals↗
PubMed1981

[On the evaluation of health factors in high-rise buildings. 2. Bioclimatological consequences resulting from comparative measurements of the air ionisation in a high-rise building located in a heavily contaminated suburban area and at certain altitudes (author's transl)].

According to accepted scientific theories inhaled small ions deliver their charges in the pulmonary alveoli and this leads to local recharges. This process stimulates structures of the central nervous system and the activity of the endocrine is excited, resulting in an enhancement of the general well-being. These possibilities of interpretation regarding a biological ionic effect are supported, with reservations (e.g. effects produced by a change in climate), by positive medical effects during and after a stay in a well-ventilated mountain climate or also in a sea-climate. Owing to their lower mobility the large ions are inhaled as small ions to an increasing extent. The chemical and physical noxa are delivered and deposited in the respiratory tract. They "stick" the epithelia in the trachea and in the bronchi as well as the endothelia in the lung vesicles. The number of the ciliary movements is reduced. Similar effects are known to be caused also by nicotine abuse. This results in a decreased ability of expectoration and a lower intake of oxygen by the alveoli. These facts could furnish an explanation for the increased vulnerability of city dwellers to infections diseases and to catarrh. The changed ionisation of air in urbanised areas (mainly large ions in high concentrations) definitely represents only one of the many risk factors. In addition to the attempt to characterize bioclimatically local weather conditions by means of the non-conventional parameter "air ionisation" our study has also been intended to establish biologically oriented criteria for the living in a high-rise building in a particularly unfavourable location. Under specific microclimatic conditions the uppermost storeys were at times bioclimatically favoured over the lowermost, especially when shallow air inversion is present. In such cases, small ions exclusively were registered in the upper storeys and large ions in the lower floors.

Air Ionization↗
PubMed1980

Improvement of hearing after microsurgical removal of acoustic neurinoma.

A case of a 3-cm acoustic neurinoma totally excised with preservation of the facial and cochlear nerves is reported. Hearing was not impaired by the operation, but dramatically improved within 2 months. The literature on operations of acoustic tumors with preservation of hearing is reviewed. In patients with some hearing ability, the operation should be conservative, whatever the size of the neurinoma, because there is a fair chance of success.

Adult↗
PubMed1980

[Results of artificial immunization of Rh-negative persons for the production of anti-D(RhO)-antibodies].

By means of a recording sheet the data about 62 artificially immunised male persons are evaluated retrospectively. 51 of them (82.3%) were anti-D-antibodies, with 41 of them having a high titer sufficient for gaining plasma. 2/3 of all test persons formed an accompanying antibody anti-C. In order to avoid this, persons of Rh-formula Cde may be included into artificial immunisation. An anti-E as an accompanying antibody was found in 2/3 of those test persons who had received injections of cDE blood. The blood of this Rh-formula will yield better immunising results than cDe blood. It was only in three immunised persons (4.8%) that side effects with a light or medium course of seriousness could be observed. It is necessary to develop immunobiological investigation methods to recognize those persons prior to the arteficial immunisation, who are suitable or unsuitable for anti-D-antibody formation.

Adult↗
PubMed1980

[Distribution and activities of enzymes in humeral epiphyses of albino rats of a specific age].

In the cartilage epiphysis of newborn, 8-, 30-, and 60-day-old Sporague-Dawley rats, 5'-nucleotidase, adenosine triphosphatase, alkaline and acid phosphatase activities were found. The main centre of activity of nearly all enzyme reactions is situated, with only small temporal differences in animals of all age groups in the middle and distal cells of the column cartilage, the proximal hypertrophic cells and the chondrocytes of the opening zone. The cells of the tangential layer in the articular cartilage of newborn and 8-day-old rats demonstrate 5'-nucleotidase activity.

Acid Phosphatase↗
PubMed1980

[Structure-activity relationship in the enzymatic hydrolysis of dipeptide aryl amides by dipeptidyl peptidase IV].

Quantitative structure activity analysis of the substrate types Ala-Ala-AR and Ala-Pro-AR containing different substituents in the aryl ring showed that the rate-limiting step in the hydrolysis of the alanine substrates by dipeptidyl peptidase IV occurs in th acylation reaction (kcat approximately k2). Probably, the tetrahedral intermediate of the acylation process has a real life time. The positive q-value of the Hammett-equation in k'cat suggests that the N-atom of the arylamide is charged more negatively in the transition state TI not equal to than in the original state TI. The analysis of the quantitative conformation activity relationship (QCAR) gives information on the steric situation in the tetrahedral intermediate of the acylation step near the transition state. The rate limiting step in the hydrolysis of the substrates of the proline type occurs in the deacylation reaction.

Dipeptides↗
PubMed1980

[Fracture of the collum of femur as a consequence of disturbed function in patients with resected stomach (Billroth II) (author's transl)].

Disturbed metabolism of bones like osteoporosis are not completely physiological in elder persons. In all cases it is needed to search for the origin. Under the intestinal factors is a slight calcium deficiency with food of a great importance for genesis of osteoporosis stimulating a occult secondary hyperparathyroidism. If vitamin D-deficiency is added a osteomalacic component is following called "Osteoporomalacia". This mixed form is typical for intestinals. Especially elder patients are endangered because the supplying of calcium and vitamin D also the calcium absorption are decreasing with getting elder. The calcium absorption is also smaller in patients with resected stomach (Billroth II). When the function in resected stomach is disturbed like in our case of afferent-loop-syndrome a osteoporosis with osteomalacic component and pathological fractures can develop. In such cases teamwork is worthwhile.

Aged↗