Search PubMed⌕ Search

Biomedical subjects

E Bock

Publications and source records attributed to E Bock.

At least 163 records · Page 9Linked to original sources

[Amino acid administration in acute, compensated renal failure in the post-traumatic phase].

Three patient groups compensated acute renal failure and previous surgery were evaluated, who had been nourished isocaloric (1700 kcal) and practically isonitrogen (33-35 g amino acid), but of various mixtures of amino acids. Besides the uniform daily energy intake of 750 ml of 40% invert sugar and 250 ml of 20% Lipofundin, the daily amino acid infusion of group I (n = 13) was only 500 ml EAS pfrimmer (34.5 g), of group II (n = 10) 250 ml EAS pfrimmer and 250 ml of 7.5% Intrafusin, and of group III (n = 16) 250 ml EAS pfrimmer and 350 ml Aminofusin Hepar (33.1 g). During evaluation of the aminograms, low initial values under the bottom reference region of glycine, serine, arginine and histidine in serum were recorded at the start of the trial in all 3 patient groups. During the course of the 4-day infusion therapy, the serum values of patients in groups II and III appeared to improve more than those in group I. Contrarily, the serum levels of phenylalanine, methionine and 3-methyl histidine were 2-3 times higher than the reference region at the start of the trial. With regard to a decrease in the high serum levels, patient group II appeared to be superior to groups I and III. No significant differences were observed during the clinical course.

Acute Kidney Injury↗

Monoclonal antibody immunocytochemistry: novel method extending usefulness of monoclonal antibodies for antigen visualization.

We describe a novel procedure combining the multiple-site reactivity of polyclonal antibodies with the defined single epitope-specificity of monoclonal antibodies. The method is based on previous findings that IgG molecules often only react with tissue-bound antigens with one of their two antigen-combining sites; thus, the remaining site is free to bind subsequently added antigen. In the procedure devised, such (undenatured) antigen is subsequently detected by a specific monoclonal antibody and the reaction is finally revealed by immunogold-silver staining. Antibody subpopulations to contaminating antigens may well be present in the polyclonal antiserum and may well bind first to tissue and then to the corresponding contaminants in the crude antigen preparation applied as second layer. Such contaminants will, however, not react with the monoclonal antibody and will therefore not be immunocytochemically detected. The method has been evaluated with one antigen which cannot be detected by monoclonal antibodies in paraffin sections (glial fibrillar acidic protein) and with another antigen (human chorionic gonadotropin) which can only be detected by the monoclonal antibody when occurring in high concentrations. In both cases the procedure resulted in strong specific staining of the antigens with no background.

Animals↗

Rounded atelectasis: considerations on its radiological diagnosis.

Rounded atelectasis is a particular form of peripheral lung collapse, adjacent to the pleura and causing a pulmonary opacity, often resembling a neoplastic mass. Its early identification avoids further investigations with more invasive techniques, especially unnecessary thoracotomy. The aim of this report is to contribute some case studies to the body of information which characterizes this radiographic and tomodensitometric entity; aspiration biopsy can possibly be performed to resolve diagnostic uncertainties.

Adult↗

Expression of the cell adhesion molecules N-CAM and L1 in B16 melanoma cells.

The cell adhesion molecules N-CAM and L1 are important for cell-cell recognition and cell migration and so may be involved in the metastatic process. We have studied the biosynthesis of N-CAM and L1 in the B16 melanoma cell lines B16-F1 and B16-F10 which differ in metastatic capacity. N-CAM was synthesised as two glycosylated polypeptides with Mr of 150,000 and 210,000; L1 was synthesised as one polypeptide with Mr of 215,000. In fetal neurons N-CAM is synthesised as a 135,000 and a 200,000 Mr polypeptide and L1 as a 200,000 Mr polypeptide. Thus, the Mr of N-CAM and L1 in tumour cells appeared to be 10,000-15,000 higher than in the normal cells. L1 was phosphorylated in the tumour cells as in neurons. The tumour cells also phosphorylated the 210,000 Mr N-CAM polypeptide, whereas no phosphorylation of the 150,000 Mr polypeptide was observed. In neuronal cells both the corresponding polypeptides are phosphorylated and thus the biosynthesis of N-CAM in tumour cells seem to differ from that in neuronal cells with regard to phosphorylation. No differences in biosynthesis of N-CAM or L1 were apparent between the two tumour cell lines, B16-F1 and B16-F10.

Antigens, Surface↗

Immunocytochemical demonstration of calmodulin in cells secreting by exocytosis.

Calmodulin is a regulator of several calcium-dependent cellular processes. It has been suggested that it plays a role in the mechanism of secretion. Employing an indirect immunoperoxidase technique at the light microscope level, this study demonstrates the presence of calmodulin in several exocytotic cells (mast cells, thyroid follicular cells, neurohypophyseal neurosecretory terminals, pancreatic beta-cells and pancreatic acinus cells) in rat and man. The positive staining reaction for calmodulin was granular and at least in the case of rat mast cells it appeared to be associated with the granule membrane.

Animals↗

Purification of gamma-enolase messenger ribonucleic acid from rat brain by an immunoadsorption method.

Messenger ribonucleic acid (mRNA) coding for the brain-specific protein gamma-enolase was isolated by an immunopurification procedure. Rat brain polysomes including nascent polypeptide chains were reacted with specific gamma-enolase antibody. The polysome-antibody complexes were subsequently adsorbed to protein A-Sepharose. After extensive washing, RNA was eluted and applied to an oligo(dT)-cellulose column. Purified mRNA was translated in vitro in a mRNA-dependent rabbit reticulocyte lysate system. The synthesized product was identical to gamma-enolase synthesized by free polysomes from rat brain. Immunoisolated gamma-enolase mRNA was enriched 380-fold compared to total mRNA extracted from free polysomes. This result indicates that low-abundance mRNAs may conveniently be isolated from brain tissue by immunoadsorption of polysomes.

Animals↗

Demonstration of immunochemical identity between the nerve growth factor-inducible large external (NILE) glycoprotein and the cell adhesion molecule L1.

The nerve growth factor-inducible large external (NILE) glycoprotein and the neural cell adhesion molecule L1 were shown to be immunochemically identical. Immunoprecipitation with L1 and NILE antibodies of [3H]fucose-labeled material from culture supernatants and detergent extracts of NGF-treated rat PC12 pheochromocytoma cells yielded comigrating bands by SDS-PAGE. NILE antibodies reacted with immunopurified L1 antigen, but not with N-CAM and other L2 epitope-bearing glycoproteins from adult mouse brain. Finally, by sequential immunoprecipitation from detergent extracts of [35S]methionine-labeled early post-natal cerebellar cell cultures or [3H]fucose-labeled NGF-treated PC12 cells, all immunoreactivity for NILE antibody could be removed by pre-clearing with L1 antibody and vice versa.

Adrenal Gland Neoplasms↗

Differentiation markers (S-100, GFAP, NSE and D2) in fetal rat brain cells during malignant transformation in cell culture.

Malignant cell lines obtained by ethylnitrosourea (EtNU)-induced transformation of fetal rat brain cells in culture express protein markers of different types of neural cells. These are the nervous system-characteristic S-100 protein; glial fibrillary acidic protein (GFAP); neuron-specific-enolase (NSE), and the D2-cell adhesion molecule. S-100 protein was absent in fetal brain cells in culture, but gradually appeared in the later stages of malignant transformation and further increased at onset of rapid growth of atypical cells (stage IV). GFAP and D2 were weakly expressed in primary fetal brain cells and did not change throughout malignant transformation. NSE was present in both normal and carcinogen-treated fetal brain cells, and increased at later stages of malignant transformation. From stage III (40-100 days) some cultures were strongly positive and some negative, and the same was seen in the resulting tumorigenic cells about 100 days later. In conclusion the stepwise process of malignant transformation of brain cells in culture ended with a stable phenotype of cells capable of expressing varying types of differentiation markers. The presence of these markers in rat brain cells undergoing malignant transformation may indicate that EtNU given at 18th days of gestation is acting on multipotent neuroectodermal cells.

Animals↗

High cerebrospinal fluid concentration of glial fibrillary acidic protein (GFAP) in patients with normal pressure hydrocephalus.

The concentration of glial fibrillary acidic protein (GFAP) in lumbar cerebrospinal fluid (CSF) was measured in 12 patients with normal pressure hydrocephalus (NPH) 11 patients with primary degenerative dementia (PDD), 8 patients with various other neurological diseases, and 18 patients without signs of organic nervous disease (controls). Mean CSF GFAP concentration was significantly higher in NPH patients: 96 +/- 23 ng/ml (SEM) when compared with PDD patients: 8.2 +/- 1.9 ng/ml (P less than 0.01), or with controls: 4.3 +/- 0.7 ng/ml (P less than 0.01). Only 2 NPH patients had a GFAP concentration within the range of the control group (2-14 ng GFAP/ml CSF). No significant differences were found between the PDD patients and the control group, or between the group of patients with other neurological diseases and the control group. In addition, a rostro-caudal gradient of GFAP in CSF could be demonstrated. In 6 NPH and 2 PDD patients both ventricular and lumbar CSF samples were investigated. In all cases the ventricular GFAP concentration was higher than the lumbar concentration. The difference was statistically significant (P less than 0.01). Our results suggest that determination of CSF GFAP concentration might be of diagnostic value in discrimination between NPH patients and patients with enlarged ventricles associated with degenerative brain disease.

Adult↗

Quantification of glial fibrillary acidic protein (GFAP) in human body fluids by means of ELISA employing a monoclonal antibody.

Soluble glial fibrillary acidic protein (GFAP) was quantified in human cerebrospinal fluid (CSF) and amniotic fluid. A normal value in lumbar CSF of 4.3 +/- 0.7 ng GFAP/ml (mean +/- SEM) was obtained from 18 non-neurological patients. Increased GFAP concentrations in CSF were found in patients with intracranial tumours or with normal pressure hydrocephalus, while normal values were found in multiple sclerosis patients and in patients with degenerative dementia. In addition, a concentration gradient between ventricular and lumbar CSF was demonstrated, the GFAP content being significantly higher in ventricular than in lumbar samples. Amniotic fluids from normal pregnancies contained 13 +/- 5.5 ng GFAP/ml (N = 117). Increased GFAP concentrations were observed in amniotic fluid from some but not all pregnancies with fetal anencephaly or encephalocele, but not from pregnancies with fetal spina bifida or any of the other fetal malformations investigated. The quantification method was an enzyme-linked immunosorbent assay employing a monoclonal antibody specific for GFAP.

Amniotic Fluid↗

Biosynthesis of the neural cell adhesion molecule: characterization of polypeptide C.

The biosynthesis of the neural cell adhesion molecule (N-CAM) was studied in primary cultures of rat cerebral glial cells, cerebellar granule neurons, and skeletal muscle cells. The three cell types produced different N-CAM polypeptide patterns. Glial cells synthesized a 135,000 Mr polypeptide B and a 115,000 Mr polypeptide C, whereas neurons expressed a 200,000 Mr polypeptide A as well as polypeptide B. Skeletal muscle cells produced polypeptide B. The polypeptides synthesized by the three cell types were immunochemically identical. The membrane association of polypeptide C was investigated with methods that distinguish peripheral and integral membrane proteins. Polypeptide C was found to be a peripheral membrane protein, whereas polypeptides A and B were integral membrane proteins with cytoplasmic domains of approximately 50,000 and approximately 25,000 Mr, respectively. The affinity of the membrane binding of polypeptide C increased during postnatal development. The posttranslational modifications of polypeptide C were investigated in glial cell cultures, and it was found to be N-linked glycosylated and sulfated.

Age Factors↗

Enzyme-linked immunosorbent assay for the human glial fibrillary acidic protein using a mouse monoclonal antibody.

Two enzyme-linked immunosorbent assays (ELISAs) have been developed for the quantification of soluble human glial fibrillary acidic protein (GFAP). The specificity of the assays for GFAP is ensured by the use of a monoclonal antibody directed against a GFAP-specific antigenic determinant. One ELISA is a four-layer system working in the concentration range 5-600 ng GFAP/ml. The other ELISA is a five-layer system and includes a biotin/avidin binding reaction. The latter assay has a working range of 0.5-60 ng GFAP/ml. The assays may be used for quantification of GFAP in CSFs, amniotic fluids, and extracts or homogenates of normal and pathological brain material. GFAP in serum could not be quantified because of unidentified interference. CSFs from 18 nonneurological subjects were found to contain 2-14 ng GFAP/ml (mean 4.1 ng/ml), whereas amniotic fluids from 50 normal pregnant women contained up to 24 ng GFAP/ml (mean 12.4 ng/ml). GFAP concentrations in CSFs from 32 multiple sclerosis patients were found not to be elevated compared to the control group.

Adolescent↗

Cell-free synthesis of the D2-cell adhesion molecule: evidence for three primary translation products.

The D2-cell adhesion molecule (D2-CAM) is a membrane glycoprotein that is involved in cell-cell adhesion in the nervous system. To study the biosynthesis of D2-CAM we have translated free and membrane-bound polysomes from rat brain in vitro in the rabbit reticulocyte lysate system. D2-CAM was exclusively synthesized on membrane-bound polysomes. The primary translation products of D2-CAM were three polypeptides of apparent molecular weights 187,000, 134,000, and 112,000. No interconversion between these polypeptides was detected. In contrast to previous suggestions, we conclude that all three D2-CAM polypeptides are primary translation products. When translating polysomes from embryonic and postnatal rat brain, we found that the relative amounts of the three polypeptides synthesized varied with age. Their molecular weights, however, were not age-dependent.

Age Factors↗

A developmental study of the biosynthesis of the neural cell adhesion molecule.

The neural cell adhesion molecule (N-CAM) is a glycoprotein found in neurons, glial cells and muscle cells. In this report we describe developmental changes in biosynthesis of N-CAM polypeptides in rat forebrain explant cultures. N-CAM was synthesized as the following polypeptides: HMr (Mr between 250,000 and 350,000), A (200,000 Mr), B (135,000 Mr) and C (115,000 Mr). The biosynthetic pattern of N-CAM polypeptides changed during development: the biosynthesis of HMr and C increased relative to A and B. N-CAM biosynthesis decreased 100-fold from embryonic day 17 to postnatal day 25; N-CAM turnover decreased 350-fold during the same period. N-CAM polysialylation and sulfatation decreased markedly with age, whereas phosphorylation seemed to be constant during development. Only polypeptides A and B were phosphorylated, whereas A, B and C were sulfated. A was more sulfated and phosphorylated than B. It is concluded that the above described modulations of N-CAM may be of importance in the developmental regulation of cell-cell adhesion.

Age Factors↗

[Efficacy of early amino acid substitution in gastrectomized patients].

Postaggression metabolism is characterized by decisive, hormone dependent metabolic changes. All reactions are directed with top priority toward ensuring the energy supply. To this end glycogenolysis, gluconeogenesis and lipolysis are increased. Since this reaction of the organism can barely be influenced and it appears to be teleologically purposeful, many authors have repeatedly attempted to achieve a utilization of nutrients as high and economic as possible using an infusion regimen adapted to these conditions. We studied the efficiency of one such adapted nutritional regimen during the first four postoperative days in 10 patients who had undergone gastrectomy. The patients were given 1 g/kg B.W. daily of an amino acid solution adapted to postaggression metabolism, plus 4 g/kg B.W. carbohydrates. We found that clinically relevant parameters such as glucose in serum, triglycerides in serum and pre-albumin could be kept in the reference range. Amino acid homeostasis remained stable under the infusion of the stress adapted amino acid solution. A rise in urea production was not observed. We conclude that good conditions for an economic utilization of the amino acids were created by the infusion regimen selected by us. These results probably can still be optimized by targetted preoperative nutrition with the goal of improving the protein status of such patients already during the preoperative phase.

Aged↗

Long-lived metastable states and hysteresis in the binding of acetylcholine to Torpedo california acetylcholine receptor.

Studies of the binding of [3H]acetylcholine to receptor-rich membranes of Torpedo californica electric organ under conditions that normally lead to a state of equilibrium did not give rise to equilibrium binding curves. Instead, the acetylcholine receptor was found to develop very long lived metastable states resulting in hysteresis in binding. Under conditions where the concentration of free [3H]acetylcholine is both less than 0.1 microM and smaller or comparable to the total receptor concentration, the degree of binding of acetylcholine depends on the rate, i.e., the mode, of increasing the acetylcholine concentration (rapid mixing vs. dialysis). The equilibrium positive cooperativity in high-affinity acetylcholine binding previously inferred from the data is deceiving; the curvature in Scatchard representations is a consequence of long-lived nonequilibrium distributions between high-affinity and lower affinity receptor conformers. By manipulation of the experimental conditions, true equilibrium binding, resulting in a linear Scatchard binding curve, was obtained and yielded the apparent equilibrium constant, K = 5 +/- 1 nM at 4 degrees C. The stoichiometry of the high-affinity site associated with this K value was found to be one acetylcholine per receptor monomer (Mr 250 000) when carefully standardized [3H]acetylcholine analyzed for both radiopurity and acetylcholine concentration was used. While our fresh membrane fragments prepared in the presence of 4 mM Ca2+ revealed up to twice as many 125I-alpha-bungarotoxin sites in 0.1% nonionic detergent relative to those assayed in the absence of detergent, nonionic detergent treatment of membrane fragments did not result in any change in total available acetylcholine binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

The neural cell adhesion molecule L1 is distinct from the N-CAM related group of surface antigens BSP-2 and D2.

The neural cell adhesion molecule L1 and the group of N-CAM related molecules, BSP-2 and D2 antigen, are immunochemically distinct molecular species. The two groups of surface molecules are also functionally distinct entities, since inhibition of Ca2+-independent adhesion among early post-natal mouse cerebellar cells by Fab fragments of both antibodies are at least additive, when compared with equal concentrations of the individual antibodies.

Animals↗

An unusual kind of muscular and skeletal involvement in a heroin addict. A case report.

After a brief review of the infectious complications that frequently occur in heroin users, the authors report a case of chronic osteomyelitis affecting the ulnar diaphysis bilaterally. Musculo-cutaneous dystrophic lesions were also present and resulted in forced flexion of the distal phalanges of fingers 2-5. The most likely pathogenetic development discussed.

Adult↗