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Biomedical subjects

C Walzer

Publications and source records attributed to C Walzer.

At least 37 records · Page 2Linked to original sources
PubMed1996

New alterations of serum glycoproteins in alcoholic and cirrhotic patients revealed by high resolution two-dimensional gel electrophoresis.

Plasma protein are synthesized and secreted by the liver. Several reports have shown that excessive consumption of ethanol interferes with the hepatic protein synthesis and/or secretion. This study was undertaken to identify the plasma/serum proteins altered in two groups of patients with different alcohol-related diseases: actively drinking alcoholic patients group without liver disease and alcohol cirrhotic patients group. Two-dimensional gel electrophoresis was used to separate proteins with high resolution. Proteins were detected by silver staining and glycoproteins were specifically visualized and analyzed after lectin blotting followed by chemiluminescence detection. Different protein alterations were identified in each group of patients. In the alcoholic group, two new glycosylation modifications of serum proteins were identified. An abnormal microheterogeneity of haptoglobin and alpha1-antitrypsin was detected in the serum of all alcoholic patients. We also characterized by two-dimensional gel electrophoresis the carbohydrate deficient transferrin. The modifications of haptoglobin, alpha1-antitrypsin and transferrin present a similar change of charge and molecular weight in the two-dimensional gel electrophoresis pattern. These qualitative estimations support the hypothesis of a general mechanism of liver glycosylation alteration of serum proteins induced by excessive alcohol consumption. The immunoglobulin alterations were easily visualized and identified for the cirrhotic and the alcoholic patients. And finally, the decrease of haptoglobin and albumin spots for cirrhotic patients was confirmed.

Alcoholism↗
PubMed1996

Immunodetection and quantitation of imidazoline receptor proteins in platelets of patients with major depression and in brains of suicide victims.

BACKGROUND: Imidazoline receptors are a newly discovered family of receptors, some of which, like alpha 2-adrenoceptors, have a presynaptic inhibitory effect on the release of norepinephrine. The aim of this study was to identify by immunodetection imidazoline receptor proteins in human platelets and the brain to assess their status in depression and suicide. METHODS: Platelets were collected from 26 drug-free depressed patients and 26 controls. Specimens of frontal cortex (Brodmann area 9) were collected from 13 suicide victims and 11 controls. Levels of imidazoline receptor proteins were assessed by immunoblotting techniques. Solubilized imidazoline receptors were separated by gel electrophoresis, transferred to nitrocellulose membranes, labeled with a specific anti-imidazoline receptor antiserum, and quantitated by image analysis. RESULTS: Platelet and brain membranes expressed similar 45-kd imidazoline receptor proteins, and their mean +/- SEM immunoreactivities were found to be increased in depressed patients (platelets, 40% +/- 5%) and suicide victims (brain, 51% +/- 14%). Platelets also expressed a 35-kd imidazoline receptor protein that was also found to be up-regulated in depressed patients (21% +/- 4%). In contrast, brain membranes did not express this 35-kd protein but revealed a 29/30-kd imidazoline receptor protein that was found to be down-regulated in suicide victims (19% +/- 3%). In a subset of depressed patients who underwent antidepressant treatment, a change in the immunoreactivity of the up-regulated 45-kd platelet imidazoline receptor protein (-35% +/- 5%), but not of the 35-kd protein, was observed. CONCLUSION: The results support a role for the newly discovered imidazoline receptors (mainly the 45-kd receptor expressed in the brain and platelets) in the pathogenesis of depression.

Adult↗
PubMed1995

Human blood platelet protein map established by two-dimensional polyacrylamide gel electrophoresis.

Two-dimensional (2-D) maps of cytosol and enriched-membrane platelet proteins has allowed the identification of more than 25 spots by three different methods: matching of the platelet gels with other 2-D reference maps, immunoblotting with chemiluminescence detection, and N-terminal sequencing. Different G protein (guanosine triphosphate-binding protein) subunits, cytoskeletal proteins, and proteins common to the human liver, red blood cells and plasma were identified. The two platelet protein maps presented here contribute to the project of identification of human cell and body fluid proteins. They may serve as working tools since platelets are popular models for the study of central nervous system neurotransmitter systems and stimulus-response coupling mechanisms.

Blood Platelets↗
PubMed1995

Rapid detection of the main human plasma glycoproteins by two-dimensional polyacrylamide gel electrophoresis lectin affinoblotting.

Glycoprotein modifications in the glycan moiety can occur in diseases such as cancers, inflammatory processes and alcoholism. We combined high-resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) with lectin affinoblotting in order to establish the normal human plasma glycoprotein map. Human plasma proteins were separated by mini 2-D PAGE (7 x 9 cm), transferred onto polyvinylidene difluoride membranes and incubated with biotinylated lectins. We focused our study on lectins binding sialic acid and galactose residues. Known plasma glycoproteins such as alpha 1-antitrypsin, alpha 1-antichymotrypsin, alpha 2-HS glycoprotein, alpha 1-acid glycoprotein, haptoglobin beta-chain and transferrin were easily detected in ng amounts. This protocol was adequate to establish a normal plasma glycoprotein map and will allow the study of glycoproteins in diseases.

Electrophoresis, Gel, Two-Dimensional↗
PubMed1995

Alcohol flushing, patch test, and ADH and ALDH genotypes in Brazilian ethnic groups.

Self reports of flushing reaction after drinking, cutaneous sensitivity to alcohol (patch test), and genotypic determination of ADH2, ADH3, and ALDH2 were studied in 53 Brazilian volunteers of different ethnic groups. Genotypes were determined using single-strand conformation polymorphism in discontinuous buffer electrophoresis. Analysis of the results indicated several cases of a reported flushing reaction among ALDH2 1/1 individuals, while all but 2 cases of ALDH2 heterozygotes reported a flushing reaction. The latter subjects also had a negative result in the patch test. These preliminary results indicate that variability in the facial flushing reaction to alcohol seems to be a phenomenon resulting not only from the presence of a deficient ALDH2*2 allele, but also from other polymorphisms of alcohol-metabolizing enzymes.

Adult↗
PubMed1994

Analysis of glycoproteins separated by two-dimensional gel electrophoresis using lectin blotting revealed by chemiluminescence.

The carbohydrate structures of blotted glycoproteins can be analyzed by probing with lectins. The objective of the present work was to optimize the lectin blotting of human plasma glycoproteins separated by two-dimensional gel electrophoresis and the detection by the sensitive chemiluminescence method. The proposed detection method was found to be ten times more sensitive than a standard colorimetric reaction. Furthermore, the generated signals are detected on a X-ray film and provide a permanent record. The method is also very reliable when compared to the colorimetric detection. The present procedure for glycoprotein analysis is particularly well suited for screening changes in glycosylation of proteins in biological samples.

Adamantane↗
PubMed1994

Influence of genetic variation in alcohol and aldehyde dehydrogenase on serotonin metabolism.

The influence of genetic variation in alcohol dehydrogenase (ADH; EC 1.1.1.1) and aldehyde dehydrogenase (ALDH; EC 1.2.1.3) on the metabolic pattern of serotonin (5-hydroxytryptamine, 5-HT) in humans was examined from the relative urinary concentrations of the end products 5-hydroxyindole-3-acetic acid (5-HIAA) and 5-hydroxytryptophol (5-HTOL). Healthy Caucasian (Swedish) and Oriental (Chinese) subjects were genotyped for ADH2, ADH3 and ALDH2 by a PCR/SSCP technique. The 5-HTOL/5-HIAA ratios ranged between 0.9-9.4 pmol/nmol (4.4 +/- 1.8, mean +/- SD, n = 143). No significant difference in the 5-HT metabolic pattern was observed between Caucasians and Orientals (4.3 +/- 1.8 and 4.4 +/- 1.8 pmol/nmol, respectively), nor between any of the ADH2, ADH3 and ALDH2 genotypes. Despite the modulatory effects of genetic variation of these enzymes on ethanol metabolism, the present results indicate that the individual isozyme composition of ADH2, ADH3 and ALDH2 is not important for the metabolic pattern of 5-HT.

Alcohol Dehydrogenase↗
PubMed1993

Plasma and red blood cell protein maps: update 1993.

This publication updates the reference plasma and red blood cell protein maps obtained with immobilized pH gradients. Seventeen polypeptide spots or chains were partially characterized by direct N-terminal sequencing or by sequencing of peptides obtained from enzymatic digestion. Additional new polypeptides and previously known proteins are listed in a table and/or labeled on the protein maps, thus providing the 1993 update of the human plasma and red blood cell two-dimensional gel SWISS-2DPAGE database. SWISS-2DPAGE and the SWISS-PROT protein sequence databases are closely linked together through the use of common accession numbers.

Amino Acid Sequence↗
PubMed1993

Determination of human alcohol dehydrogenase and acetaldehyde dehydrogenase genotypes by single strand conformation polymorphism in discontinuous buffer electrophoresis.

Under appropriate conditions single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) products allows the detection of single base mutations in a given DNA fragment. We adapted this method for the routine determination of allele variants of human alcohol and acetaldehyde dehydrogenase without radioisotopic labeling. After PCR amplification of the selected exon, the DNA fragments were heat-denatured and loaded on a polyacrylamide gel containing glycerol. For electrophoresis a discontinuous buffer system was used with sulfate as leading ion and borate as trailing ion. The DNA bands were revealed by silver staining. Acrylamide concentrations, ionic strength and electrophoresis temperature were systematically investigated for each DNA fragment. The polymorphisms detected by SSCP were identical to those found by hybridization with 32P-labeled allele-specific oligonucleotides. This method avoids the use of radioactivity, is less expensive and simpler than the allele-specific oligonucleotide (ASO) methodology and thus particularly suited for routine analysis.

Alcohol Dehydrogenase↗
PubMed1992

Red blood cell protein map: a comparison between carrier-ampholyte pH gradient and immobilized pH gradient, and identification of four red blood cell enzymes.

The aim of this study was (a) to establish a red blood cell (RBC) protein map with immobilized pH gradient for the first dimension (b) to compare the pattern with previously published RBC protein map obtained with carrier-ampholyte pH gradients and (c) to localize four new enzymes on the map (i.e. 6-phosphogluconic dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glutathione peroxidase and superoxide dismutase). This publication provides the most updated RBC polypeptide pattern with twelve proteins or enzymes localized on the map.

Blood Protein Electrophoresis↗
PubMed1989

Thermolysin treatment: a new method for dermo-epidermal separation.

The epidermis of superficial human skin samples could easily be separated from the dermis following incubation at +4 degrees C for 1 h in a solution containing 250-500 micrograms/ml thermolysin, a proteolytic enzyme hitherto mostly used for protein analysis. Light and electron microscopy revealed that the dermo-epidermal separation occurred at the basement membrane between the sites of bullous pemphigoid antigen and laminin and that the hemidesmosomes were selectively disrupted. The cohesion and morphology of the separated epidermis as well as the immunologic parameters investigated were not altered by this procedure. The clear cut dermo-epidermal separation produced by thermolysin treatment differed from the separation obtained with trypsin, which predominantly occurred between basal and suprabasal cells by disruption of desmosomes.

Adult↗
PubMed1987

Ultrastructural study of the long-term development of two experimental cutaneous calcinoses (topical calciphylaxis and topical calcergy) in the rat.

Skin calcification induced by topical calciphylaxis was provoked by a subcutaneous injection of iron chloride in rats previously sensitized by dihydrotachysterol. A cutaneous topical calcergy was induced by an injection of potassium permanganate. An electron-microscopical study of the long-term evolution of both these models of calcification was made. After the initial stages, mineralization of the connective tissue continued by a secondary nucleation process without matrix vesicles. The mineral composed of needle-like structures, apatite in nature, was mainly deposited between and around collagen fibrils, and showed various arrangements in calcified plaques. Intrafibrillar calcification was rarely observed and appeared only in the later stages. The extension of calcified deposits then stopped. Finally, there was a fragmentation of the mineralized area which was progressively surrounded by uncalcified collagen fibrils. A demineralization process, caused by cells such as macrophages and multinucleated giant cells, rather than a resorption of the calcified deposits, was noted. It is important to emphasize that, in both models of ectopic calcification, an evolution toward ectopic ossification was never observed, which is perhaps due to the absence of extensive resorption mechanisms.

Animals↗
PubMed1986

Cytochemical expression of epidermal peroxidase and cytochrome oxidase activities in pathological skin conditions of man.

The cytochemical expression of epidermal peroxidase and cytochrome oxidase activity was recently well documented in normal human skin. We report here its expression in basal and squamous cell carcinomas, actinic keratoses, psoriasis, allergic contact dermatitis, seborrheic keratoses, and autosomal dominant ichthyosis vulgaris. The two enzyme activities were evaluated using the diaminobenzidine method. If present, the two enzymes were always localized in the same organelles as in normal epidermis: endogenous peroxidase in the nuclear envelope and endoplasmic reticulum, and cytochrome oxidase in mitochondria. In basal and squamous carcinomas, actinic keratoses and psoriasis, the keratinocytes lost their peroxidase activity, but maintained their cytochrome oxidase activity. In seborrheic keratoses, allergic contact dermatitis and ichthyosis vulgaris, the cytochrome oxidase activity was greatly reduced or abolished in keratinocytes, Langerhans' cells, and melanocytes, whereas the peroxidase activity was present as in normal epidermis. These results indicate that the two peroxidatic enzymes studied are not interrelated and alternatively suppressed by different cellular dysfunctions.

3,3'-Diaminobenzidine↗
PubMed1986

[Direct identification of Chlamydia trachomatis using fluorescent monoclonal antibodies in infections of the lower urogenital tract].

Direct identification of Chlamydia trachomatis with fluorescent monoclonal antibodies in smears was recently introduced for a rapid diagnosis of lower urogenital tract infections. In the present study the performance of this method was compared with that of the classical cell culture procedure with McCoy cells and iodine staining on 880 clinical specimens (table I). One hundred and twenty specimens in which one of the two methods failed for technical reasons are therefore not available for comparison. Among the remaining 760 specimens there was agreement between the two methods in 724 (95 p. 100). The sensitivity of direct identification was 85 p. 100, its specificity 97 p. 100 (table II). Our results are comparable to those reported in the literature and confirm that direct identification of Chlamydia trachomatis with fluorescent monoclonal antibodies is a useful, reasonably sensitive method for rapid diagnosis of this infection. Failures, which are relatively frequent (8 p. 100 in our series), are mostly due to inadequate specimen collection, the smears containing no epithelial cell.

Antibodies, Monoclonal↗
PubMed1984

[Generalized ichthyosis associated with a spastic syndrome of the lower limbs, a variant of Sjögren-Larsson syndrome? Light and electron microscopy study of ichthyosis and its evolution with oral etretinate treatment].

A generalized ichthyosis with an associated spastic syndrome of the lower extremities, clinically suggestive of Sjögren-Larsson syndrome, was observed in a Tunisian boy. The fatty acid analysis of the serum phospholipids revealed significant abnormalities in the fatty acid pattern of phospholipids. However, the alterations observed were different from those reported in Sjögren-Larsson syndrome. We report light and electron microscopic changes in the ichthyotic skin of this patient, which have not been previously reported in lamellar ichthyosis and in Sjögren-Larsson syndrome. The epidermis was moderately hyperplastic and covered with a thick, compact, orthokeratotic stratum corneum. The stratum spinosum was strikingly altered in some areas. Varying numbers of keratinocytes contained big vacuoles, measuring often up to the size of the nuclei; the vacuoles, were well limited but only partially lined by a membrane, they were empty or contained small amounts of a flaky material. Attempts to stain the vacuoles with PAS, Alcian blue and Fettrot were negative. Etretinate treatment produced a marked shedding of the horny layer without significant improvement of the clinical appearance. The described microscopical alterations of the epidermis remained mostly unchanged during treatment, but, in addition, a marked oedema and vacuolisation of the upper stratum granulosum was observed.

Child↗
PubMed1983

Ultrastructural demonstration of endogeneous peroxidase activity in mammalian epidermis.

With the diaminobenzidine method, endogenous peroxidase activity was demonstrated in the nuclear envelope and in the endoplasmic reticulum of non-keratinized keratinocytes and Langerhans cells of the epidermis of the newborn mouse, adult guinea pig and man. In the guinea pig all non-keratinized layers of keratinocytes showed this enzyme activity, whereas in the two other species examined peroxidase activity was limited to the suprabasal layers. The most pronounced activity was found in the Langerhans cells. The melanocytes were negative. With the same method, cytochrome c/cytochrome oxidase activity could be localized in the mitochondria of all epidermal cells of mouse and man, but not in the guinea pig.

3,3'-Diaminobenzidine↗
PubMed1983

Calcergy and calciphylaxis: timed appearance of gamma-carboxyglutamic acid and osteocalcin in mineral deposits.

gamma-Carboxyglutamate (Gla), a calcium binding amino acid whose synthesis depends on vitamin K, has been found in association with pathologic calcifications. It is of interest therefore to examine the role of Gla-containing proteins in the formation of nonskeletal mineralized tissues. Calcergy and calciphylaxis, experimentally induced models of pathologic calcification, offer the opportunity to study the formation of mineral deposits in the absence of an endochondral sequence of bone formation. Before induction of subcutaneous calcinosis by topical treatment with the direct calcergen, KMnO4, or by challenging dihydrotachysterol-sensitized animals with FeCl2, control specimens contain no gamma-carboxyglutamic acid. With the initial formation of cytoplasmic vesicles, calcium content of the tissues increases and Gla is detected. Gla levels are further elevated with the appearance of poorly crystalline apatite-like crystallites. Origin of protein bound Gla was established by positive identification of osteocalcin by radioimmunoassay. Gla and osteocalcin appear concomitant with the earliest mineral deposits observed by electron microscopy and micro X-ray analysis. The formation of organized extracellular pattern by X-ray diffraction allowed sufficient mineral accumulation for detection with calcium, Gla, and osteocalcin increasing allowed sufficient mineral accumulation for detection of an apatite-like pattern by X-ray diffraction with calcium, Gla, and osteocalcin increasing proportionately as mineral is deposited.

1-Carboxyglutamic Acid↗