Cuprizone Administration Alters the Iron Metabolism in the Mouse Model of Multiple Sclerosis.

Cuprizone (CZ) is a widely used copper chelating agent to develop non-autoimmune animal model of multiple sclerosis, characterized by demyelination of the corpus callosum (CC) and other brain regions. The exact mechanisms of CZ action are still arguable, but it seems that the only affected cells are the mature oligodendrocytes, possibly via metabolic disturbances caused by copper deficiency. During the pathogenesis of multiple sclerosis, high amount of deposited iron can be found throughout the demyelinated areas of the brain in the form of extracellular iron deposits and intracellularly accumulated iron in microglia. In the present study, we used the accepted experimental model of 0.2% CZ-containing diet with standard iron concentration to induce demyelination in the brain of C57BL/6 mice. Our aim was to examine the changes of iron homeostasis in the CC and as a part of the systemic iron regulation, in the liver. Our data showed that CZ treatment changed the iron metabolism of both tissues; however, it had more impact on the liver. Besides the alterations in the expressions of iron storage and import proteins, we detected reduced serum iron concentration and iron stores in the liver, together with elevated hepcidin levels and feasible disturbances in the Fe-S cluster biosynthesis. Our results revealed that the CZ-containing diet influences the systemic iron metabolism in mice, particularly the iron homeostasis of the liver. This inadequate systemic iron regulation may affect the iron homeostasis of the brain, eventually indicating a relationship among CZ treatment, iron metabolism, and neurodegeneration.

Stable gastric pentadecapeptide BPC 157 in trials for inflammatory bowel disease (PL-10, PLD-116, PL 14736, Pliva, Croatia). Full and distended stomach, and vascular response.

Gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419, safe in clinical trials for inflammatory bowel disease (PL 10, PLD 116, PLD 14736, Pliva, Croatia)) has a particular cytoprotective/adaptive cytoprotective activity. The cytoprotective/adaptive cytoprotection researches largely neglect that stomach distension could per se jeopardize the mucosal integrity, with constantly stretched mucosa and blood vessels, and sphincters more prone for reflux induction. After absolute alcohol instillation in fully distended rat stomach, gastric, esophageal and duodenal lesions occur. Throughout next 3 min, left gastric artery blood vessels clearly disappear at the serosal site, indicative for loss of vessels both integrity and function. Contrary, constant vessels presentation could predict the beneficial effect of applied agent. After pentadecapeptide BPC 157 instillation into the stomach the vessels presentation remains constant, and lesions of stomach, esophagus, and duodenum are inhibited. Standards (atropine, ranitidine, omeprazole) could only slightly improve the vessels presentation compared to control values, and they have only a partial effect on the lesions. In this review we emphasize BPC 157 unusual stability, and some of its important effects: effectiveness against various lesions in gastrointestinal tract, on nitric oxide (NO)-system, and NO-agents effects, on somatosensory neurons, salivary glands function, recovery of AMP-ADP-ATP system, endothelium protection, effect on endothelin, and on angiogenesis promotion. It also antagonizes other alcohol effects, including acute and chronic intoxication. Given peripherally, it counteracts the consequence of central dopamine system disturbances (receptor blockade), and induces serotonin release in substantia nigra. Therapeutic potential of BPC 157 as a cytoprotective agent is also seen in its capability to heal various wounds. Given directly into the stomach, BPC 157 instantly recovers disturbed lower esophageal and pyloric sphincter pressure in rats after 12-20 months of untreated esophagitis. All these could be suggestive for its role as a natural protectant in gastric juice with particular function throughout stomach distension.

REG can be used to detect cerebrovascular alteration caused by alcoholism.

Despite recent evidence of the beneficial effects of moderate alcohol consumption in arteriosclerosis prevention, the neurotoxic effects of alcohol abuse are well known. Our hypothesis was that uncontrolled alcohol consumption may cause cerebrovascular damage detectable by rheoencepholography (REG), a noninvasive bio-impedance technique for estimating cerebral blood flow. Test subjects were 48 alcoholic patients in Hungary; the control group consisted of 12 drug-addicted and depressed patients in Hungary and 13 healthy male subjects in the United States. Additional subgroups were formed according to smoking habits and average daily alcohol dose. REG was measured by a computer-based system, "Cerberus"; REG anacrotic time above 180 ms was considered pathological. ANOVA showed that daily alcohol consumption and smoking were significantly higher in alcoholics than in drug-addicted and depressed patients. Twelve alcoholics showed a pathological REG anacrotic time. Longer REG anacrotic time was correlated with higher daily alcohol consumption. In the alcoholic group, the steeper regression line of REG slope reflected the pathological impact of alcohol abuse. The healthy control sample showed a nearly identical slope for both REG and age. The correlation of increased REG anacrotic time and daily alcohol consumption supports the hypothesis that REG detects accelerated cerebrovascular aging (arteriosclerosis) in alcoholic subjects.

Cloning, sequencing, structural and molecular biological characterization of placental protein 20 (PP20)/human thiamin pyrophosphokinase (hTPK).

Full-length cDNAs of placental protein 20 (PP20) were cloned by screening a human placental cDNA library, which encode a 243 amino acid protein, identical to human thiamin pyrophosphokinase (hTPK) as confirmed by protein sequence analysis. Genomic alignment showed that the PP20/hTPK gene contains 9 exons. It is abundantly expressed in placenta, as numerous EST clones were identified. As thiamine metabolism deficiencies have been seen in placental infarcts previously, these indicate that PP20/hTPK may have a role in placental diseases. Analysis of the 1kb promoter region showed numerous putative transcription factor binding sites, which might be responsible for the ubiquitous PP20/hTPK expression. This may also be in accordance with the presence of the protein in tissues responsible for the regulation of the exquisite balance between cell division, differentiation and survival. TPK activity of the purified and recombinant protein was proved by mass spectrometry with electrospray ionization. By Western blot, PP20/hTPK was found in all human normal and tumorous adult and fetal tissues in nearly equal amounts, but not in sera. By immunohistochemical and immunofluorescent confocal imaging methods, diffuse labelling in the cytoplasm of the syncytiotrophoblasts and weak staining of the trophoblasts were observed, and the amount of PP20/hTPK decreased from the first trimester to the end of gestation. A 3D model of PP20/hTPK was computed (PDB No.: 1OLY) by homology modelling. A high degree of structural homology showed that the thiamin binding site was highly similar to that of the mouse enzyme, but highly different from the bacterial ones. Comparison of the catalytic centre sequences revealed differences, raising the possibility of designing new drugs which specifically inhibit bacterial and fungal enzymes without affecting PP20/hTPK and offering the possibility for safe antimicrobial therapy during pregnancy.

Opposite regulation of uncoupling protein 1 and uncoupling protein 3 in vivo in brown adipose tissue of cold-exposed rats.

Earlier we reported a 14-fold increase of glycogen in the brown adipose tissue (BAT) in rats when the animals were placed back from cold to neutral temperature. To elucidate the mechanism, here we compared the level of glucose transporter 4 (GLUT4) protein, uncoupling protein (UCP) 1 and UCP3 mRNA and protein expressions in the BAT under the same conditions. We found that the increased GLUT4 level in cold was maintained during the reacclimation. After 1 week cold exposure the mRNA and protein content of UCP1 increased parallel, while the protein level of UCP3 decreased, contrary to its own mRNA level.

[Plasma electrolytes in multiple myeloma]. / A vérplazma elektrolitjai myeloma multiplexben.

The plasma cell myeloma (multiple myeloma, myelomatosis) is a progressive disease, characterized by bone marrow plasmacytomas and the presence of monoclonal antibodies (IgG, IgA, IgD, IgE), or free kappa or lambda immunoglobulin side chains. The monoclonal antibodies or Bence-Jones protein may precipitate in the tubuli and impair kidney function. In addition, the plasma protein concentration may increase at the expense of plasma water level causing unrealistically low electrolyte levels. Since the isoelectric points of immunoglobulins are higher than those of most other plasma proteins, the net charge of plasma proteins may change causing new electrolyte balance. In addition, some monoclonal antibodies are more hydrated than others, and their high concentration may cause not only increased plasma viscosity but further electrolyte imbalance. In the present work the relationship between plasma protein and electrolyte levels is studied in samples of 100 multiple myeloma patients.

Differential effect of shear stress on extracellular signal-regulated kinase and N-terminal Jun kinase in endothelial cells. Gi2- and Gbeta/gamma-dependent signaling pathways.

Shear stress differentially regulates production of many vasoactive factors at the level of gene expression in endothelial cells that may be mediated by mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK) and N-terminal Jun kinase (JNK). Here we show, using bovine aortic endothelial cells (BAEC), that shear stress differentially regulates ERK and JNK by mechanisms involving Gi2 and pertussis toxin (PTx)-insensitive G-protein-dependent pathways, respectively. Shear activated ERK with a rapid, biphasic time course (maximum by 5 min and basal by 30-min shear exposure) and force dependence (minimum and maximum at 1 and 10 dyn/cm2 shear stress, respectively). PTx treatment prevented shear-dependent activation of ERK1/2, consistent with a Gi-dependent mechanism. In contrast, JNK activity was maximally turned on by a threshold level of shear force (0.5 dyn/cm2 or higher) with a much slower and prolonged time course (requiring at least 30 min to 4 h) than that of ERK. Also, PTx had no effect on shear-dependent activation of JNK. To further define the shear-sensitive ERK and JNK pathways, vectors expressing hemagglutinin epitope-tagged ERK (HA-ERK) or HA-JNK were co-transfected with other vectors by using adenovirus-polylysine in BAEC. Expression of the mutant (alpha)i2(G203), antisense G(alpha)i2 and a dominant negative Ras (N17Ras) prevented shear-dependent activation of HA-ERK, while that of (alpha)i2(G204) and antisense (alpha)i3 did not. Expression of a Gbeta/gamma scavenger, the carboxyl terminus of beta-adrenergic receptor kinase (betaARK-ct), and N17Ras inhibited shear-dependent activation of HA-JNK. Treatment of BAEC with genistein prevented shear-dependent activation of ERK and JNK, indicating the essential role of tyrosine kinase(s) in both ERK and JNK pathways. These results provide evidence that 1) Gi2-protein, Ras, and tyrosine kinase(s) are upstream regulators of shear-dependent activation of ERK and 2) that shear-dependent activation of JNK is regulated by mechanisms involving Gbeta/gamma, Ras, and tyrosine kinase(s).

Phenylalanine utilization for protein synthesis in beta-phenylpyruvic acid treated Escherichia coli cells.

The possibility of coupling along the supply routes of phenylalanine from its uptake by the cell, through the charging of specific tRNAs, has been postulated. The experimental approach to testing this hypothesis has been to study the competition between endogenously synthesized and exogenously supplied amino acids, from which preferences for their incorporation into cellular proteins can be deduced. The results indicate that manipulation of the endogenous phenylalanine pool size, achieved by addition of its immediate precursor, beta-phenylpyruvate, does not cause the predicted changes in the incorporation of exogenous labelled phenylalanine into proteins. The evidence favours exogenous phenylalanine being preferentially delivered to the sites of protein synthesis.

Human myeloid cell nuclear differentiation antigen binds specifically to nucleolin.

The human myeloid cell nuclear differentiation antigen (MNDA) is a nuclear protein expressed specifically in cells of the myelomonocytic lineage and regulated by interferon alpha in a cell-specific fashion. MNDA is also a member of a family of interferon-regulated genes of unknown function. In an effort to elucidate the function of MNDA, three techniques (affinity purification, coimmunoprecipitation, and protein blot assay) were used to characterize its specific protein binding activities. Microsequence analysis showed that MNDA bound the 100 kDa nucleolin protein. The identification of nucleolin was confirmed by immunoreaction with specific antibodies. MNDA contains motifs which could account for specific binding to nucleolin. Nucleolin binds other macromolecules and exhibits features consistent with roles in signal transduction, production of ribosomes, nuclear matrix structure, and regulation of transcription. The present results indicate that the function of MNDA is most likely related to interactions with other proteins. Through these associations, MNDA could contribute cell/lineage- and differentiation-specific limits to the function of ubiquitous proteins such as nucleolin. Further analysis of MNDA protein binding could be critical to elucidating the function of MNDA and could contribute to understanding the function of the products of other members of this interferon-inducible family of genes.

A complex cerebrovascular screening system (CERBERUS).

Stroke is unique among neurological diseases since it has a high incidence rate, severe burden of illness, high economic cost, and it may be preventable [1]. Described here is a system for screening the cerebral and vascular status of individuals to detect the initial stages of vascular disorders. The computer based polygraphic system (CERBERUS) questions subjects about risk factors, stresses, neurologic symptoms and monitors impedance pulse waves of the head and extremities, EEG, and ECG. The system has been tested in 691 cases. Doppler control studies were carried out on approximately 300 of these cases. Additional somatic measures and psychological tests related to stroke risk factors were carried out for wide biological basis of possible correlation of CERBERUS data base. The high incidence of cerebrovascular disturbance was established by CERBERUS data, further confirmed by additional data gathered, and moreover was compared by traditional medical records. The polygraphic system is more sensitive at detecting physiological asymmetries of blood flow than even a Doppler measurements. This suggests that it may be a significantly improved means for the differential diagnosis of neurological disease and the screening of subjects for arteriosclerosis, transient ischemic attack and stroke prevention to be offered at the lowest level of medical service.

Acid-extractable amino acid pool in Escherichia coli: possible role in energy-independent amino acid accumulation and protein synthesis.

The acid extractable amino acid pool (AEP) demonstrates time and concentration dependent saturation kinetics in cold-incubated (0-2 degrees C) Escherichia coli cells. Attention is drawn in particular to the contribution of the AEP to the total non-covalently bound amino acid intracellular levels (total pool) at low exogenous amino acid concentrations. Amino acids compete with one another for associations which internally constitute the AEP. Although physicochemically related amino acids tend to be better competitors than other amino acids, the physicochemical relatedness was by no means the sole, or necessarily the main, factor determining competitiveness. On the return of cells to incubation temperatures allowing protein synthesis to proceed, the contribution of the AEP to protein synthesis was explored.

Nucleolin promotes secondary structure in ribosomal RNA.

The effect of nucleolin on the secondary structure of RNA was studied using circular dichroism (CD). Nucleolin caused decreases in the main positive bands and shifts to higher wavelengths in the CD spectra of synthetic polynucleotides such as poly(G) and poly(A) indicating helix destabilizing activity. In contrast, nucleolin effected increases in signal and shifts to lower wavelengths of the peaks of CD spectra of ribosomal RNA, suggesting enhancement of secondary structure. Another major nucleolar RNA binding protein, B23, had helix destabilizing activity but did not enhance RNA secondary structure. It is proposed that nucleolin promotes formation of secondary structure in preribosomal RNA during the early stages of ribosome biogenesis.

[The significance of immunological constellation with regard to the development of hypersensitivity against various chemical compounds (author's transl)]. / Die Bedeutung der immunologischen Konstellation bei der Entwicklung einer Uberempfindlichkeit gegen verschiedene Chemikalien.

Biopon is a generally used detergent containing detergens which does not cause hypersensitivity as was demonstrated by the authors in previous animal experiments. In the present study the authors describe the Haptene character of Biopon which quality could be demonstrated by causing a certain immunological constellation in guinea-pigs on the grounds of a hypothesis. The hypothetical concept consisted in aiding a half-antigen in the organism even in the case of its intradermal injection into a thick immunocompetent cell agglomeration. The authors produced the agglomeration of cells of the skin by means of intradermal injections of alien serum and in with BCG treated animals with tuberculin reaction. Biopon was administered thereafter into the focus by intradermal injection. The presented two aiding methods showed different effects which the authors try to explain by the fact that different adjuvants cause different effects.