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Biomedical subjects

M Siegert

Publications and source records attributed to M Siegert.

At least 19 recordsLinked to original sources

Quantification of cerebrospinal fluid proteins in children by high-resolution agarose gel electrophoresis.

Physiologic alterations in cerebrospinal fluid proteins occur inter alia with aging. Agarose gel electrophoresis discriminates many cerebrospinal fluid proteins and in addition quantifies concentration alterations. This study aimed to investigate the time course of these alterations in children and to establish normative values for cerebrospinal fluid protein properties. In 202 children without diseases known to alter cerebrospinal fluid, normative protein properties were quantified using nephelometry, ultrafiltration, high-resolution electrophoresis, and Gaussian curve fit densitometry. Total protein and protein concentrations (albumin and gamma-globulins) decreased from birth until 7 months age, and, from then on, increased slightly (transthyretin, albumin, and alpha2-proteins) or strongly (gamma-globulins). Protein proportions (transthyretin and transferrin) increased until about 3 years of age and decreased from then on. These normative values for children as quantified by high-resolution agarose gel electrophoresis are presented in a significance-structured percentile table. The time courses of these cerebrospinal fluid properties reflect physiologic alterations of the blood-brain barrier function during childhood.

Adolescent↗

Nutritionally-induced elevation of serum proteinase inhibitors and reduced 3-methylhistidine excretion in the rat.

One group of growing rats was fed ad libitum a low protein and energy diet (PER). A second group was fed a low protein diet (PR). Both these groups showed a gain in weight below that of the control group. A third group was fed a very low protein and energy diet (VPER). A weight gain could also be observed in this group but this gain was lower than those observed in the first two groups. A fourth group that was on a very low protein diet (VPR) gained almost no weight. After 6 weeks a significant reduction in 3-methylhistidine excretion in urine was observed in all the experimental animals with lowest values found in the VPER and VPR groups. Total serum protein levels declined to a certain extent because of the protein and energy restrictions but albumin and transferrin remained largely unaffected. Significantly lower serum concentrations were found only in the VPR group. The rat serum proteinase inhibitors alpha 1-macroglobulin and alpha 1-inhibitor3 decreased when protein and energy were restricted and alpha 1-proteinase inhibitor decreased only in the VPER and VPR groups. alpha 2-macroglobulin and alpha 1-cysteine proteinase inhibitor concentrations increased considerably in the serum of the experimental groups. The results are discussed in relation to the probable role of the latter two inhibitors in the adaptation process when protein and energy were restricted and compared to similar observations recorded in man.

Animals↗

CSF protein profile in infantile spasms. Influence of etiology and ACTH or dexamethasone treatment.

CSF proteins in 107 children ranging from 3 to 24 months of age were analyzed by means of quantitative zone electrophoresis on agarose gel. Subjects included 50 children with infantile spasms, 41 children without CNS disease serving as controls, and 16 infants with acute aseptic meningitis who demonstrated the protein pattern of blood-CSF barrier disturbance. Children with infantile spasms were subdivided into several groups according to etiological categories: symptomatic (pre-, peri-, and postnatal), doubtful, and cryptogenetic. Before any treatment was started, these children showed the protein profile of increased permeability of the blood-CSF barrier, especially for albumin. There was an association between the severity of the changes and the etiological category. Changes were most marked in the symptomatic group, intermediate in the doubtful group, and slight in the cryptogenetic group. No child with infantile spasms of doubtful or unknown etiology revealed changes of the immunoglobulin-containing gamma fractions. Ten children who had received adrenocorticotropic hormone (ACTH) or dexamethasone for 2-11 weeks no longer showed any protein leakage into the CSF. The period of ACTH or dexamethasone treatment was characterized by the following findings: the disappearance or reduction of hypsarrhythmia; the reappearance of normal cerebrovascular permeability for protein; and the occurrence of reversible dilatation of the subarachnoid and intraventricular spaces.

Acute Disease↗

[Serum proteins of growing Gunn rats. Quantitative analysis with agarose gel electrophoresis (author's transl)].

Microprocesses of quantitative agarose gel electrophoresis and biuret total protein evaluation were used for the quantitative estimation of the serum proteins of homozygous and heterozygous Gunn rats. For the analyses carried out in the course of hyperbilirubinemia, 6 microliter of serum were necessary in each case, of which 50-80 microgram were used for electrophoresis. The quantitative evaluation of the phoretogram curves plotted at two wavelengths was carried out with the aid of an analog computer. Eleven fractions were quantitatively covered by the process. Age-related concentration shifts were observed for a number of fractions, especially for albumin, transferrin, and IgG. The results obtained from a large number of animals in longitudinal and cross-sectional examination corroborate various reports found in the relevant literature.

Animals↗