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Biomedical subjects

A Engelhardt

Publications and source records attributed to A Engelhardt.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Congenital toxoplasmosis with delayed immune response in children. Diagnostic problems].

A newborn, delivered at term, developed a rapidly increasing hydrocephalus with intracranial calcifications and seizures during the first week of life. Clinical suspicion of congenital toxoplasmosis was at first not confirmed serologically (serum titer in the immunofluorescence test [IFT] of 1:1024 and complement-fixation reaction [CFR] of 1:40 equalling those of the mother; IgM-IFT being negative and the IFT and CFR titers significantly falling within two weeks). But in the further course of the disease the diagnosis of congenital toxoplasmosis was confirmed: 1. Microscopic tachyzoits in CSF when aged six weeks; 2. positive IgM-IFT in serum and CSF from the seventh weeks onwards; 3. steep IFT titer rise in serum and CSF from the 16th week onwards. This case demonstrates that with delayed immune response in the infected child only serial serological tests will exclude or confirm the diagnosis of congenital toxoplasmosis.

Antibodies, Bacterial↗
PubMed1987

[Somatosensory evoked potentials following tactile skin stimulation].

Somatosensory evoked potentials were recorded for tactile stimuli applied to the fingers II and V as well as paravertebrally. The advantage of the painless mechanical stimuli is their specificity and the well defined stimulus localization. The question was therefore if the evoked responses are clearly demarcated. Nack potentials (N22: 22.5 and 22.3 ms) as well as cortical SEP's (P1: 33.2 and 32.8 ms) were easily to derive. It was also possible to get SEP's for segmental paravertebral tactile stimuli. For the finger stimulation an Erb's potential could not be recorded reliably.

Adolescent↗
PubMed1987

Parenteral nutrition with an amino acid solution containing a mixture of dipeptides. Evidence for efficient utilization of dipeptides in man.

Ten healthy human subjects received parenteral nutrition consisting of 80 g of a dipeptide-amino acid mixture and 900 carbohydrate calories infused over a period of 12 h, and then fasted for another period of 12 h. The dipeptides included in the mixture were: glycyl-L-glutamine, glycyl-L-tyrosine, glycyl-L-leucine, glycyl-L-isoleucine, and glycyl-L-valine. Parenteral nutrition with the dipeptide-amino acid mixture was without any adverse reaction in any of the subjects. The urinary excretion of the 5 dipeptides during parenteral nutrition ranged between 1 and 2% of the amount infused. Plasma concentrations of dipeptides during parenteral nutrition, which ranged from 8-96 microM reflected their plasma half-lives. Glycyl-L-glutamine had the longest half-life, glycyl-L-leucine and glycyl-L-tyrosine the shortest half-lives. During parenteral nutrition there were increases in plasma amino acid concentrations including those of glutamine and tyrosine. Discontinuation of parenteral nutrition resulted in the disappearance of dipeptides from plasma, and the dissipation of increased plasma amino acid concentrations. In conclusion, the present results show efficient utilization of glycyl-dipeptides as substrates for parenteral nutrition in man. The results further show that the structure of amino acids in the C-terminal position has a significant influence on the metabolism of dipeptides.

Adult↗
PubMed1985

Ethanol and polyneuropathy.

Two groups of alcoholics (30 patients each)--identified by the MALT score--were examined. Clinical and laboratory investigations showed no connection between thiamine, riboflavin, or Vitamin B6 deficiency and development of the polyneuropathy. Neither the polyneuropathy nor the diminished sensory conduction velocity were related to malnutrition. The relation between the duration of alcoholism and symptoms of polyneuropathy was highly significant in one group. The neurotoxicity of ethanol was confirmed in an experiment with rats.

Adult↗
PubMed1985

[Acute cerebellar encephalitis in adulthood].

Two cases of rare adult cerebellar encephalitis are reported presenting the distinguishing features of acute onset of cerebellar ataxia, distinct ocular oscillations (opsoclonus, ocular flutter, macro square wave jerks) and generalized myoclonic jerks. The EOG-analysis of the cerebellar oculomotor disorder is emphasized. The course is usually benign ("benign encephalitis") differing from the childhood form only in age of onset. Fatal courses are rare and the histopathologic findings in one case suggest mild encephalitis with diffuse perivascular lesions accentuated in the cerebellum, thus not allowing clear clinicotopodiagnostic correlations.

Acute Disease↗
PubMed1980

Detection of acid mucopolysaccharides in human brain tumors by histochemical methods.

Acid mucopolysaccharides (glycosaminoglycans) are identified by histochemical methods in biopsies of 107 human brain tumors. Isomorphous oligodendrogliomas and astrocytomas stained with alcian blue show marked, weblike, or diffuse distribution and concentration of acid mucopolysaccharides. Histochemically, the characteristics of hyaluronic acid and chondroitin sulphate are found. They seem to be closely associated with the cytoplasmic membrane of the tumor cells. Increased dedifferentiation and malignancy lead to a progressive loss of alcianophilia. In tumors such as ependymomas, meningiomas, sarcomas, and medulloblastomas, concentration of alcian blue is found only in the blood vessel walls and connective tissue. In neurinomas a greater amount of acid mucopolysaccharides can be shown not only in the collagen fibers but also in tumor areas of the Antoni-B-type. One case of cerebral neuroblastoma revealed marked alcianophilia of the parenchyma and stroma. As with findings in experimental brain tumors, an altered regulation of the carbohydrate metabolism of the glia cells during neoplastic transformation is discussed as a reason for the alcianophilia of gliomas.

Astrocytoma↗
PubMed1979

Pharmacology and toxicology of Atrovent.

The anticholinergic drug ipratropium bromide (Atrovent) can be described as having pharmacologically a high degree of activity and a certain bronchoselectivity when administered intravenously. Inhalation studies, however, indicate that this is the most suitable route of administration. Inhalation provides with small doses the most effective concentration locally at the smooth muscle of the airways without producing anticholinergic side effects due to absorption from the airways or from the gastrointestinal tract. In certain experimental models of allergic asthma, ipratropium bromide was shown to be capable of influencing favourably bronchoconstriction and mediator release. Extensive toxicological examinations revealed with high doses all typical symptoms of overdosing an anticholinergic drug, like mydriasis, dryness of the mucosae and meteorism with coprostasis. Acute and long term inhalation studies gave no evidence for a functional and morphological impairment of the lungs and airways.

Animals↗
PubMed1977

[Problems in dose finding Practical examples presented on selected series of drugs: bronchospasmolytics, pharmacology (author's transl)].

The beta-adrenergic agents and the anticholinergics are cited as examples of the contribution of experimental pharmacology to determining dosage of bronchodilator drugs in man. With regard to animal species, data from dogs can be extrapolated better to man than data from guinea-pigs. As far as the modes of administration are concerned, results from inhalation studies can be extrapolated directly to man, without conversion. Greater caution is required for parenteral injection and oral administration. However, even here we have an example of effective oral dose in dogs, which correlates with the single dose in man when the difference in body-weight is taken into account. The guinea-pig is unsuitable for the oral testing.

Administration, Oral↗
PubMed1975

Experiences with Al2O3 implantations in humans to bridge resection defects.

Various implants have been developed for the upper and lower extremities and the spine. In order to establish whether endoprostheses made of Al2O3 will show the same good biocompatibility in humans as it has in experiments with animals, endoprostheses implantations were performed in 4 patients: 2 upper arms, 1 radius, 1 vertebra body. The implants were exposed to various loads. The biomechanical conditions were considered in the construction. The results reveal that the knowledge of material properties and prior calculations make possible the development of satisfactory endoprostheses. X-ray examinations confirm these deductions. Good functionality was achieved in vivo with all implants. They were all mechanially anchored, no bone cement was used. Thus the biocompatibility of the material was not limited. A histological examination is made of one implant. The macroscopic examination showed a stable fit and no pathological reactions, X-rays revealed that the bone remained in good contact with the implant. The longest observation period was over 1 1/4 years. Present observations show that the use of Al2O3 implants, without the use of additional materials (bone cement), results in a tight fit of the implants.

Aluminum↗