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At least 811 records · Page 45Linked to original sources
PubMed1991

Difference spectroscopic and kinetic studies on the interaction of lactate dehydrogenase with structurally related triazine dyes.

Difference spectroscopy and enzyme kinetics were employed to study the interaction of lactate dehydrogenase (LDH) from rabbit muscle with the azo-dye Procion Red HE-3B and two of its structural variants in order to follow the significance of the sulphonated terminal rings for the strength and specificity of binding. Procion Red HE-3B possesses a significantly higher affinity to LDH compared to the dye Cibacron Blue F3G-A, a well characterized pseudo-biospecific ligand of dehydrogenases. Moreover, Procion Red HE-3B showed competition towards the cofactor NAD+/NADH. The enzyme-dye complex is mainly stabilized by hydrophobic interactions, but other binding forces cannot be excluded. LDH possesses one dye-binding site per subunit. As a binding region the active center of LDH, preferentially the hydrophobic nicotinamide pocket is involved. Removal of the negatively charged sulphonic acid group from the terminal rings of Procion Red HE-3B decreases the affinity to LDH significantly but does not change the type of binding. Addition of an anilino group to the terminal rings of Procion Red HE-3B does not affect the affinity to the active site significantly but enables the binding on other sites with lower affinity in dependence on the dye concentration.

Animals↗
PubMed1991

[Anatomical variability of the left gastric artery and vein in newborn infants].

Structural variants of the left gastric artery (LGA) and left gastric vein (LGV) in newborns have been studied on 93 preparations of the stomach with ++extra-organic arteries and on 90 preparations of the stomach with ++extra-organic veins. There is certain correlation between the length of the trunk and character of branching of the LGA. A branch of the LGA, running to the posterior surface of the cardial part in the upper part of the gastric body, which is not described in the literature, has been found. Rather often in newborn children from the iliac trunk instead of the LGA, a left gastro-hepatic trunk has got off. The number of tributaries from the posterior surface of the gastric body to the LGV is found to be significantly greater than the number of tributaries from the anterior surface of the gastric body to this vein.

Age Factors↗
PubMed1976

[Course and outcome of treatment of synovial sarcoma].

The results of exploration of 126 patients with synovial sarcoma are reported; males -- 70, females -- 54, aged from 4 to 74 years old. The tumor was found to be localized as follows: the extremities -- 117 (upper -- 33, lower -- 84), and the body -- 9 patients. Seven structural variants of synovial sarcoma were differentiated: 1) alveolar -- 19, 2) adenomatous -- 10, 3) histioid -- 65, 4) perithelial --3, 5) fibrous -- 6, 6) gigantic-cell -- 3 and 7) mixed -- 20 patients. The patients were treated surgically (56 patients) and using the combined technics (70 patients). The most favourable results were noted in treatment of patients with adenomatous and fibrous types of synovial sarcoma, worse issues -- in patients with gigantic-cell and perithelial forms. Synovial sarcomas of histioid and mixed types occupy the intermediate place. The most malignant character of the neoplasm was observed in patients with alveolar tumor.

Adolescent↗
PubMed1991

A mouse brain homolog of the Drosophila Shab K+ channel with conserved delayed-rectifier properties.

We have cloned and expressed a mouse brain K+ channel that is the homolog of the Drosophila Shab K+ channel. Mouse and Drosophila Shab K+ channels (mShab and fShab, respectively) represent an instance of K+ channels and structurally related species that are both functionally and structurally conserved; most kinetic, voltage-sensitive, and pharmacological properties are similar for the 2 channels. The greatest functional difference between the currents is recovery from inactivation, which is several times slower for mShab than for fShab currents. In addition to conserved structure, the mShab polypeptide has an unusually long nonconserved region at the carboxyl end of the protein. Truncation of 293 residues from the carboxyl end produced no noticeable change in voltage-sensitive, kinetic, or pharmacological properties. Thus, the measured functional properties of mShab are determined by the remaining 564 residues, most of which are conserved. The mShab and fShab channels are naturally occurring structural variants having substitutions in conserved portions that appear relatively neutral with respect to all measured properties except for, possibly, the rate of recovery from inactivation. The mShab current closely resembles a native delayed-rectifier-type potassium current, IK, in hippocampal neurons.

Amino Acid Sequence↗
PubMed1978

[The appearance of pathognostic inclusion bodies in verruca vulgaris (author's transl)].

Pathognostic inclusion bodies develop in the nucleus. They frequently occur in the upper layers of the pathologically changed stratum spinosum. They are stained in an amphophilic or basophilic manner. Their structure is a nearly homogenous, finely grained or plaquelike one. The inclusion bodies contain masses of human wart viruses in a cristalline-like arrangement or are irregularily distributed. Feulgen staining is positive. Different pictures of inclusion bodies are demonstrated in paraffin sections. The knowledge of structural variants is very helpful in biopsy diagnosis of veruca vulgaris.

Cell Nucleus↗
PubMed1989

Isolation and characterization of a glycosylated form of human insulin-like growth factor I produced in Saccharomyces cerevisiae.

Expression and secretion of human insulin-like growth factor-I (IGF-I) in Saccharomyces cerevisiae was achieved by linking an actin (ACT) promoter to an MF alpha 1 prepro leader peptide/IGF-I gene fusion. Purified human IGF-I from yeast culture media was found to contain, in addition to the native form, also a glycosylated variant. Structural studies showed that both IGF-I forms were processed identically, resulting in 70-amino-acid long polypeptides, with intact N-terminal and C-terminal residues of glycine and alanine, respectively. The glycosylation site was determined to threonine-29 (Thr29), by 1H NMR spectroscopy and protein sequence analysis of an isolated tryptic peptide(22-36). No other glycosylation sites were found. Only mannose was detected in the sugar analysis, with an estimated content of 4.5% w/w corresponding to 2 mannose residues per molecule of IGF-I. The carbohydrate structure, determined by 1H and 13C NMR spectroscopy, was found to be alpha-D-Manp(1----2)alpha-D-Manp(1----3)Thr corresponding to an O-linked glycoprotein structure. No other post-translational modifications could be identified in the glycosylated IGF-I form. Furthermore, this form was highly active, comparable to native IGF-I, exhibiting a specific activity of 20,500 units/mg, as determined by a radio-receptor assay.

Actins↗
PubMed1989

Beta+-thalassemia in cis of a sickle cell gene: occurrence of a promoter mutation on a beta s chromosome.

An atypical sickle cell trait with a very low level of hemoglobin S and features of heterozygous beta-thalassemia was recently described. In vitro globin chain synthesis strongly suggested the presence of the two abnormalities on the same chromosome. We report the corresponding beta S-thal gene. DNA sequence revealed a C----T base substitution in the distal promoter element CACCC, at position-88 from the cap site, in addition to the expected GAG----GTG mutation responsible for the structural variant (beta 6 Glu----Val). Reticulocyte mRNA titration and transient assay of the mutant gene in COS cells showed a defect in beta-mRNA production. Restriction haplotype and DNA sequence analyses revealed that the doubly mutated gene is associated with haplotype 19 (or Benin/Algeria haplotype). In particular, we found the (AT)9(T)4 repeated sequences specifically encountered 5' to the beta S gene of Benin Algeria type. These results support the view that the beta S-thal gene resulted from an independent thalassemic mutation having occurred on a beta S chromosome rather than (a) from a beta S mutation having altered a beta-thalassemic gene or (b) from a recombination event between two chromosomes, each carrying one of the mutations.

Anemia, Sickle Cell↗
PubMed1989

[The effect of culturing conditions on the karyotypic structure of two cell sublines of Indian muntjak skin fibroblasts].

The "therapeutic" doses of antibiotics, routinely applied to prevent microbial contamination in cultured cells, decrease the frequency of modal class cells and increase that of cells of other classes in sublines of Indian muntjak skin fibroblasts. In MT-subline, with 9 chromosomes in the modal class, the loss of cells with some large chromosomes occurred almost frequently. In terms of the formula of the karyotype main structural variant, this change is described as (-1-0-1-1). In M-subline, with 7 chromosomes in the modal class, the similar result is mainly achieved due to a decrease in the cell number with Y1-chromosome to be described as (0-0-0-0-1). The study of frequency of deviation from the chromosome number in the MSVK has shown that in the MT-subline, rather than in the M-subline, different chromosomes are incidentally involved in the karyotypic rearrangement. In both the sublines antibiotics induced chromosomal aberrations, primarily increasing the number of dicentrics. Preferential involvement of some chromosomes in the dicentric formation was observed. Cytogenetical parameters are more affected by antibiotics in the MT-subline. The data obtained indicate that even low concentrations of antibiotics may induce karyotypic changes in cells cultures.

Animals↗
PubMed1985

Diversity of glycoprotein deficiencies in Glanzmann's thrombasthenia.

The platelet proteins of 9 thrombasthenic patients from 7 families were analysed by high resolution two-dimensional gel electrophoresis (HR-2DE) and crossed immunoelectrophoresis (CIE). In 7 patients both glycoproteins (GPs) IIb and IIIa were absent or reduced to roughly the same extent. In two related patients only a trace of GP IIb-IIIa complex was detected in CIE, but HR-2DE revealed a glycopeptide in the position of GP IIIa in an amount comparable to type II thrombasthenia. This GP IIIa-like component was neither recognized normally by anti-GP IIb-IIIa antibodies nor labeled by surface iodination. In unreduced-reduced two-dimensional gel electrophoresis two components were observed in the region of GP IIIa. The assumption of a structural variant of GP IIIa in the two related patients is discussed.

Blood Platelet Disorders↗
PubMed1986

Heart myosin light chain 2 gene. Nucleotide sequence of full length cDNA and expression in normal and hypertensive rat.

We have isolated and characterized a cDNA recombinant plasmid (pRLC429) specific for the rat heart myosin light chain 2 (MLC2). The cDNA insert consists of 446 base pairs, including a 72-base pair segment of the 3'-untranslated region. Additional 5'-sequence, not present in plasmid pRLC429, was obtained by primer extension of the cDNA. The extended cDNA sequence combined with the plasmid pRLC429 sequence provided the codon information for the entire MLC2 polypeptide and partial sequences for the 3'- and 5'-noncoding regions of MLC2 mRNA. The predicted amino acid sequence for rat heart MLC2 showed a high homology with the sequences available for the chicken (83%) and human heart (80%) MLC2s. However, the homology between rat heart MLC2 and its counterpart in rat skeletal muscle is relatively low (67%). On the basis of the nuclease S1 protection assay with uniformly labeled single-stranded pRLC429 DNA, subcloned into M13mp18 phage vector, we conclude that the rat atrial muscle also contains MLC2 of the ventricular type. In an attempt to ascertain whether structural variants of MLC2 are expressed in hypertrophic heart muscle, we examined the RNAs from spontaneously hypertensive rat where there is a natural progression of hypertrophy associated with an increase in blood pressure. The RNA isolated from 7-, 13-, and 18-week-old spontaneously hypertensive rat hearts protected the same length DNA against S1 nuclease as was observed with RNAs from the age-matched normal rat hearts, suggesting that there is a single MLC2 gene transcript expressed in both the normal and hypertrophic heart muscle cells.

Amino Acid Sequence↗
PubMed1986

[Biosynthesis in the rat liver of a common form of monooxygenase induced by xenobiotics of a methylcholanthrene series].

Injection of Wistar rats with five structurally different inducers of methylcholanthrene-type (polycyclic aromatic and heterocyclic hydrocarbons, chloro-derivatives of biphenyl and dibenzo-p-dioxin) results in the de novo synthesis of two P-448 hemoproteins (molecular weight 56 000 and 53 000 Da) differing in their functional and immunochemical properties in liver microsomes. A comparison of catalytic and immunochemical characteristics of five cytochrome P-448 forms (Mr = 56 000 Da) as well as the data from electrophoretic, proteolytic and inhibitory analyses revealed no differences in the preparations used, with the exception of 2,3,7,8-tetrachloro-dibenzo-p-dioxin-induced microsomes characterized by a low level of this cytochrome P-448 form and a higher molecular activity as compared with 3,4-benzpyrene and 7-ethoxyresorufin-induced microsomes. The experimental results do not confirm the hypothesis on the feasibility of induced synthesis of a variety of individual forms of monooxygenase that would correlate with the number of structural variants of inducers.

Animals↗
PubMed1985

Cyclosporine: the agent and its actions.

The serendipitous discovery of a new species of fungi T inflatum Gams coupled with the diligent investigations of Borel to dissect the immunosuppressive action of CsA have yielded a new reagent of compelling therapeutic moment. Due to its relatively specific inhibition of lymphokine generation by T helper cells, the drug displays relatively high therapeutic efficacy for the immune system. The major obstacle to almost uniform success is drug-induced nephrotoxicity, which not only occurs frequently but also is discerned with difficulty from allograft rejection. Nephrotoxicity may occur in the absence of toxic CsA drug levels, and therefore cannot be totally excluded by presently available tools, probably due to synergistic injuries to the allograft by drugs, donor ischemia, procurement injury, rejection, and so forth. Although present data and likely hypotheses suggest that immunosuppressive and nephrotoxic effects are closely correlated, careful chemical dissection of the differential immunosuppressive and toxic activities of CsA metabolites and/or structural variants may afford new approaches to improve the therapeutic window for effective CsA use.

Animals↗
PubMed1988

[Effect of cultivation conditions on the karyotype structure of a cell subline of the kangaroo rat kidney].

Variations in cultivation conditions were found to exert influence on the distribution of cells for chromosome number by changing the modal class. The change of the HMEM medium for the EMEM medium during 2-6 passages results in the appearance of a new modal class with 16 chromosomes. The change in the chromosome number is preferably due to the loss of one X chromosome within the main structural variant of the karyotype (MSVK). On the other hand, the change of the HMEM medium for the F12 medium during 4-6 passages does not affect the cell distribution for the chromosome number. A comparative analysis of the total frequency of the MSVK cells and that of MSVK cells of the modal class showed that the karyotypic changes took place in all the variants, both in the modal class and beyond it due to other additive SVK. An exception is the variant NBLD (change of HMEM for the F12 during 6 passages). In this case chromosome changes occur mostly in the modal class, primarily due to the redistribution of chromosomes in groups. In all the variants there is an insignificant frequency of chromosomes, morphologically different from the MSVK. This confirms the findings according to which chromosomal changeability in the NBLD may be associated mostly with the change in the number of homologous chromosomes rather than with chromosomal aberrations. The frequency of chromosomal aberrations is the same in all the variants examined. The dependence of karyotypic characteristics on culture media mentioned above indicate that care should be taken in choice of culture conditions for permanent cell lines.

Animals↗
PubMed1986

[Morphologic changes in the adrenal cortex in Itsenko-Cushing's syndrome].

Having studied the results of investigation of 132 patients with Icenko-Cushing syndrome (68 out of them with different structural variants of adrenal tumours, 68--without adrenal tumours), the authors came to the conclusion that adenomas of dark and mixed polymorphic cells belong to hormonally active adrenal tumours, while light-cell monomorphic adenomas belong to hormonally inactive tumours. An electron-microscopic study provides identification of signs of functional activity in adenomas and cancer tumours, to clear up the additional criteria of anaplasia in them. In patients with Icenko-Cushing syndrome, but without a tumour in the adrenal cortex ultrastructural changes in corticocytes are characteristic of the increase of cellular proliferation and the decrease of incretory activity. The follow-up results of surgical treatment were studied in all cases.

Adenoma↗
PubMedDate not supplied

[Intraspecies variability of the normal human karyotype].

On the basis of data from literature the number of different normal structural variants of each human chromosome is calculated. Assuming independent combination of chromosome variants, the number of possible combinations of variants of all 22 pairs of autosomes and the probability of an individual to be hormozygous for the most frequent variants of all the autosome pairs simultaneously are estimated. The results obtained show that nearly each individual possesses a unique karyotype--a unique set of properties of chromosome heterochromatic regions.

Chromosomes, Human↗
PubMed1980

[Interstitial substance of a chondrosarcoma (a histochemical study].

The content of acid mucopolysaccharides of the interstitial matrix of various structural variants of chondrosarcoma was studied in the operation material of 28 chondrosarcomas. The chondrosarcoma tissue contained a large amount of sulphated mucopolysacharides and a low amount of hialuronic acid. The quantity and quality of mucopolysaccharides directly depended on the degree of maturity of the tumour tissue which was reflected morphologically in the scarcity of intercellular substance in the tissue.

Adolescent↗
PubMed1983

[Development of the thoracic duct in the prenatal period of human ontogeny].

In 40 series of histological sections performed in human embryos and prefetuses from 4 up to 20 weeks of development, as well as in 20 corpses of fetuses and stillborns, it has been stated that the anlage of the thoracic duct appear in 6-7-week-old fetuses as lymphatic clefts surrounded with mesenchymal cells that are situated near large veins in the areas of the most active morphogenesis. Connecting with each other, the clefts form the jugular and retroperitoneal lymph sacs and a well branching network of canals. From the latter, on the 7th-8th week of development a plexus of lymph vessels appear, and later on (on the 8th-9th week)--bilaterally situating trunks of the thoracic duct. Further development of the thoracic duct is connected with the lymph nodes formation, their germs appear on the 9th-10th week along the course of the left trunk, as well as along the ductal branches and anastomoses. The formation of the lymph nodes results in reduction of some trunks and plexuses of the thoracic duct. Owing to this, its form in 14-15-week-old prefetuses resembles the one in newborns. Disturbances in the formation processes of the lymph nodes along the course of the reducing ductal areas, as well as their formation along the course of its main trunk can result in various structural variants of the thoracic duct in children and grown-up persons. Histogenesis of the thoracic duct wall and formation of the lymph nodes are not completed by birth.

Gestational Age↗
PubMed1983

Proline-rich polypeptides bound to rat prostatic binding protein. The primary structure of the two main components, proline-rich polypeptides IV and V.

The complete primary structures of the two main forms, PRP-IV and PRP-V, of a proline-rich polypeptide bound in vivo to rat prostatic binding protein has been determined. Their sequences were established using manual Edman degradation of the native polypeptide and of purified fragments derived from trypsin and thermolysin digestions. Both polypeptides contain 38 amino acid residues (Mr = 4397 and 4339); cysteine, methionine, and serine are missing. In spite of the high proline content (21%), no polyproline stretches were detected. PRP-IV and PRP-V show an extensive structural homology and differ only by three substitutions. These amino acid replacements are located in the NH2-terminal part of the molecule at positions 6 (His leads to Pro), 10 (Pro leads to His), and 11 (Asp leads to Gly). Moreover, each component displays a microheterogeneity at several positions in the sequence which indicates that multiple structural variants exist for PRP-IV and PRP-V. These data not only suggest the existence in rat ventral prostate of a multigene family coding for the proline-rich polypeptides but also the occurrence of a pronounced genetic polymorphism for these components. In addition, a remarkable sequence homology is observed between the PRP components and the region of the B chain in the precursor of mouse renin.

Amino Acid Sequence↗