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Biomedical subjects

R Barth

Publications and source records attributed to R Barth.

At least 91 records · Page 5Linked to original sources
PubMed1981

Immunofluorescent localization of a Ca2+-dependent neutral protease in hamster muscle.

A Ca2+-dependent neutral thiol protease is widely distributed in mammalian tissues and has been implicated in muscle protein turnover. As a first step to understanding the physiological function of this enzyme, its cellular and subcellular localization has been studied in hamster cardiac and skeletal muscle by means of indirect immunofluorescence. The results showed that the Ca2+-dependent protease is located either at the plasma membrane or in the connective tissue matrix that surrounds the muscle cels. The uniform distribution along membranes and around capillaries indicated that the protease is not confined to connective tissue cells. This evidence, together with the Ca2+-dependence of the enzyme, suggests a distribution throughout the extracellular connective tissue of the muscle. In this position, it would seem unlikely that the enzyme could participate in protein turnover within muscle cells in normal tissue.

Animals↗
PubMed1980

Evaluation of various brain structures in multiple sclerosis with multimodality evoked potentials, blink reflex and nystagmography.

Pattern reversal visual evoked potentials (VEP), blink reflexes, auditory brainstem evoked potentials (ABEP), spinal and scalp recorded somatosensory evoked potentials (SSEP), and nystagmographic records were investigated in 55 patients with multiple sclerosis (MS), who were separated in different categories of probability according to the clinical history, symptoms, and signs. The combined use of different electrophysiological methods forms a sensitive battery for investigating clinically uncertain cases of MS. It was stressed that care should be taken in the interpretation of the electrophysiological findings, since a single lesion in the central nervous system, particularly in the brainstem, may affect different functional systems simultaneously and therefore mimic a disseminated disease.

Adolescent↗
PubMed1980

Limited gallium scans and angiotensin converting enzyme in granulomatous uveitis.

The use of serum angiotensin converting enzyme (ACE) and limited gallium scans of the head, neck, and chest for patients with granulomatous uveitis is described. Mean serum ACE activity was elevated in patients with granulomatous uveitis regardless of the presence of systemic sarcoidosis. Furthermore, pathologic gallium uptake was noted in lacrimal glands, parotid glands, and lungs in some cases. These results indicate that sarcoidosis may be more common than previously believed in these patients.

Adult↗
PubMed1980

Auditory brain stem evoked potentials in patients with multiple sclerosis. Investigations in patients with different degrees of diagnostic probability.

Auditory brain stem evoked potentials (ABEPs) were investigated in 54 patients with the definite or presumed diagnosis of multiple sclerosis and compared with the results of 42 controls. All patients but one had no hearing impairment on clinical examinations. Investigation of ABEPs have shown to be useful when the diagnosis of multiple sclerosis is uncertain.

Adult↗
PubMed1980

Central somatosensory conduction time in diagnosis of multiple sclerosis.

Cervical and cortical somatosensory evoked potentials were recorded in 42 patients with suspected and certain multiple sclerosis. Absolute peak latencies as well as latency differences between the cervical components N9, N11 and N13 and between N13 and cortical N20 were measured. In addition, the right/left differences of these values were analyzed. It ws demonstrated that the central conduction times (inter-peak differences) were more sensitive diagnostic indicators than the absolute peak latencies of the same components. Thus we conclude that conduction time measurement has a complementary role in investigating functional disturbances in multiple sclerosis.

Adolescent↗
PubMed1979

Chemical and physical properties of the carboxypeptidase Y-inhibitor from Baker's yeast.

The purification as well as some characteristics of the carboxypeptidase Y-inhibitor from baker's yeast have been described in a previous report (Matern, H., Hoffmann, M. and Holzer, H. (1974) Proc. Natl. Acad. Sci. U.S. 71, 4874-4878). In this paper, chemical and physical properties of the purified inhibitor are presented. The molecular weight was estimated at 23 400--24 000 and appears to be a monomeric unit. Amino acid analysis and carbohydrate studies are given, showing the existence of three disulfide bonds and one sulfhydryl group per molecule and the absence of carbohydrate residues. The N-terminal amino acid is blocked by an acetyl group. The C-terminal amino acid is lysine. The isoelectric point (pI) is 6.6 and the inhibitor-enzyme complex is stable (at 25 degrees C) betwen pH 5 and 9. The apparent Ki value was calculated as 2.5.10(-9)M.

Amino Acids↗
PubMed1979

Diagnostic validity for different components of pattern shift visual evoked potentials in multiple sclerosis.

Visual evoked potentials, elicited by checkerboard-pattern reversal were recorded from multiple sclerosis patients with different probabilities of diagnosis. Latencies and amplitudes of the different components were analyzed for diagnostic validity. It was demonstrated that the latency of the main positive peak (P2) was the most sensitive parameter. But in a few cases determination of P2 latency and interocular difference of this peak alone failed to detect involvement of the visual system. Additional evaluation of absolute latencies, asymmetries in latency and amplitudes of other components would give evidence in predicting abnormalities of the visual pathways.

Adolescent↗
PubMed1979

[NIH potency tests with inactivated rabies vaccines (author's transl)].

63 NIH tests were analysed. A BPL inactivated tissue culture rabies vaccine No. 108 was compared with the national standard vaccine A 18 fourteen times in different tests. The results show that reproduction of results is unsatisfactory with the NIH test and that this test in its present traditional method with two injections is not very suitable for satisfactory potency evaluation of inactivated rabies vaccines. Proposals for modifications are made.

Animals↗
PubMed1979

Brachial plexus lesions in hemiplegics.

Nine hemiplegic patients with muscular atrophy in the paralysed upper limb have been subjected to a clinical and electrophysiological investigation. In all but one case with circumscribed muscular atrophy in the shoulder girdle or the small hand muscles electromyography showed evidence for denervation. The findings are consistent with traction neuropathy on the brachial plexus and its branches in spastic or hypermobile shoulder joints.

Aged↗
PubMed1978

Studies on the carboxypeptidase Y-inhibitor complex of yeast.

We report in vitro studies on the interaction of several substrates with the carboxypeptidase Y-inhibitor complex of yeast. Inhibition of carboxypeptidase Y cleavage of two peptides by carboxypeptidase Y-inhibitor is shown to be competitive. The experiments show a wide variation in the degree of cleavage of a variety of peptide substrates by carboxypeptidase Y, despite the presence of the inhibitor protein. The most likely explanation for this behaviour is a different capacity for the peptides to dissociate the inhibitor protein from the substrate-binding site of carboxypeptidase Y. While the carboxypeptidase Y-inhibitor is insensitive to proteolytic inactivation when complexed with carboxypeptidase Y, it is sensitive when in the free state. Addition of the substrate, N-Cbz-Phe-Leu, to the carboxypeptidase Y-inhibitor complex, however, allows proteolytic inactivation of the inhibitor protein. We suggest that the proteinase-inhibitor may play a crucial role in the regulation of proteinase activity. The inhibitor protein generally protects proteins from unwanted proteinase action. However, it will allow cleavage of proteins which, by some signal triggered metabolically, become substrates due to the exposure of amino acid sequences normally buried, and exhibiting a high affinity for the proteinase.

Carboxypeptidases↗
PubMed1978

Interaction of receptive field responses and shift-effect in cat retinal and geniculate neurons.

Spike activity of single optic tract fibres and lateral geniculate cells of the lightly anaesthetized immobilized cat were recorded in response to short, small (local) test flashes into the receptive field center before, during and after rapid displacements of a remote, large (global) pattern. 2. The majority of retinal and geniculate neurons failed to produce algebraic summation of the excitatory shift-effect and an excitatory test response. 3. For many cells outside lamina A and A1 of the dorsal lateral geniculate body the test response was smaller than the control even though two excitatory responses were combined. 4. The resonses to displacements of a steady, local spot are weakly affected by simultaneous displacements of a global pattern if the local responses are strong; but if the latter are weak the global shift-effect dominates the response to a displacement of the total pattern. 5. Saccadic suppression may be explained by retinal and geniculate neurons functioning in two modes of local or global responses, both of which cannot be transmitted properly at the same time.

Animals↗