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PubMed1979

Complexes of technetium with pyrophosphate, etidronate, and medronate.

The reduction of [99Tc]pertechnetate was studied as a function of pH in complexing media of pyrophosphate, methylene diphosphonate (MDP), and ethane-1, hydroxy-1, and 1-diphosphonate (HEDP). Tast (sampled d-c) and normal-pulse polarography were used to study the reduction of pertechnetate, and normal-pulse polarography (sweeping in the anodic direction) to study the reoxidation of the products. Below pH 6 TcO4-was reduced to Tc(III), which could be reoxidized to Tc(IV). Above pH 10, TcO4-was reduced in two steps to Tc(V) and Tc(IV), each of which could be reoxidized to TcO4-. Between pH 6 and 10 the results differed according to the ligand present. In pyrophosphate and MDP, TcO4- was reduced in two steps to Tc(IV) and Tc(III); Tc(III) could be reoxidized in two steps to Tc(IV) and TcO4-. In HEDP, on the other hand, TcO4- was reduced in two steps to Tc(V) and Tc(III), and could be reoxidized to Tc(IV) and TcO4-. Additional waves were observed; they apparently led to unstable products.

Diphosphates↗
PubMed1979

NADPH production in the oxidative pentose phosphate pathway as source of reducing equivalents in glycolysis of human red cells in vitro.

Studies have been carried out on human erythrocytes in vitro to clarify the deficit of pyruvate formation under conditions when 2,3 DPG is degraded. The results lead to the conclusion that there exist a cross connection between the glycolytic and the oxidative pentose phosphate pathway which is mediated by the NADP/NADPH couple. NADPH serves as additional reducing equivalent in the reaction of the LDH. In the absence of glucose the pool of the metabolites of the pentose phosphate pathway is able to supply glucose-6-phosphate for the production of NADPH by recombination. The reaction of NADPH at the LDH is probably of significance under in vivo conditions.

Diphosphoglyceric Acids↗
PubMed1979

[Microsomal hemoprotein reduction by superoxide radical formed on NADPH-specific flavoprotein].

The superoxide radicals formed on NADPH-specific flavoprotein of liver microsomes can reduce cytochromes c, b5, and P-450. This reaction is inhibited under aerobic conditions by a low molecular weight analog of superoxide dismutase, e.g. the copper-tyrosine complex. The inhibitory effect of the complex is not observed under anaerobic conditions. Based on the results obtained a scheme of the electron transfer between the flavoprotein and haemoproteins involving superoxide radicals is proposed.

Aerobiosis↗
PubMed1975

Nitroblue tetrazolium reduction test in pregnancy.

The use of the nitroblue tetrozolium (NRT) dye reduction test as a screening method for bacterial and fungal infections is now widely recognized. Levels have been reported to be falsely elevated in the pregnant state. This report includes a prospective study which showed that the results of this test in 124 pregnant women were indistinguishable from those of a normal control population. Seven of 8 elevated levels were attributable to infection or allergy. With this data, it is concluded that the NBT test can be used to screen for bacterial and fungal illnesses in a febrile pregnant patient as well as in the general population.

Bacterial Infections↗
PubMed1975

Structural studies of the Xenopus 19S immunoglobulin and 7S immunoglobulin and two immunoglobulin-like proteins.

Xenopus laevis 19S and 7S immunoglobulins (Ig) were extensively reduced and alkylated, their H and L chains spearated and their molecular weights determined. Two kinds of L chains of molecular weight 25,000 and 27,000 were revealed by SDS-polyacrylamide gel electrophoresis. In addition two Ig-like proteins consisting of heavy chains only, of 19S H-type and with similar molecular weight, were detected in Xenopus serum ans isolated. These proteins share common antigenic determinants with Xenopus 19S Ig heavy chains and are devoid of light chain determinants.

Alkylation↗
PubMed1975

Immunological properties of procollagens obtained from the culture medium of dermatosparactic cells.

Rabbit antisera were produced against purified calf dermatosparatic procollagen and against the purified procollagens obtained from the culture medium of calf dermatosparatic cells. These antisera and their derived gamma-globulins were characterized by immunoprecipitation, double immunodiffusion and immunoelectrophoresis. Antiserum directed against dermatosparatic procollagen cross-reacted with the two different forms of procollagen obtained from the culture medium of dermatosparatic calf cells. Antiserum directed against onw of these procollagens, namely (pro alpha1)2 pro alpha2, cross reacted with dermatosparatic procollagen and also cross-reacted with the other procollagen,(pro alpha1)3. Antiserum directed against procollagen (pro alpha1)3 cross-reacted with dermatosparatic procollagen and with the procollagen (pro alpha1)2 pro alpha2. None of the antisera reacted with authentic calf skin collagen, or with the collagen extracted from the cell layer of the dermatosparatic calf cells in culture. Reduction andalkylation of the procollagens abolished the antigen-antibody reactions, while prior digestion of the antigens with bacterial collagenase did not eliminate the immunological reaction. Antigenic determinants in the cell culture procollagens were found at the COOH-terminal non-collagen peptide as well as at the NH2-terminal non-collagen peptide.

Animals↗
PubMed1975

The heterogeneity of anti-DNA antibodies in systemic lupus erythematosus and other diseases.

The antigenic specificities of antinucleic acid antibodies occurring in systemic lupus erythematosus (SLE), chronic active liver disease, and progressive systemic sclerosis (PSS) have been studied by means of haptenic nucleosides and nucleotides coupled to human serum albumin. SLE sera were also tested with dinucleotides. SLE and chronic active liver disease sera showed marked heterogeneity, producing precipitin lines with nucleosides or nucleotides, or both. The reaction might occur with a nucleoside and not with the corresponding nucleotide, or vice versa. The SLE sera reacted to dinucleotides with marked specificity, being able to recognize base sequences or to react with a dinucleotide despite the absence of a reaction with the individual bases. All sera from patients with PSS showed precipitins with RNA, uridine and UMP. PSS sera which reacted with a nucleoside also reacted with the corresponding nucleotide. Antibodies to DNA were found in a smaller proportion of PSS sera than in sera from SLE or chronic active liver disease. Their presence was confirmed by reactivity with thymidine and TMP.

Antibodies, Anti-Idiotypic↗
PubMed1975

[Morphological changes in the small intestine of rats after its temporary exclusion from blood circulation].

The experiments were performed in 56 albino rats (15of them served as a control. The small intestine was excluded from the blood circulation for 45minutes and then pieces of the proximal and distal parts of the intestine were taken forhistological and histochemical study. It was shown that such a term of anemia resulted indeep but reversible changes in the mucous sheath and in the intramural nervous apparatus of thesmall intestine. The state of the organ wall became normal in 15 days after operation.

Acid Phosphatase↗
PubMed1975

[The primary structure of a monoclonic immunoglobulin-L-chain of subgroup IV of the kappa type (Bence-Jones protein Len.)].

The complete amino acid sequence of Bence-Jones protein Len. was established by sequential analysis of tryptic and chymotryptic peptides. The result of these experiments and the comparative sequence analysis with the other 17 completely determined kappa-proteins is incompatible with the serological typisation of protein Len. as a member of subgroup II: There are 18 positions in protein Len. than cannot be associated with any one of the subgroups kappaI, kappaII or kappaIII. Also the average amino acid exchange rate between protein Len. and these subgroups is in the same range as the average amino acid exchange rate between these subgroups. Therefore Bence-Jones protein Len. is the first completely determined representative of a new IV. kappa-type subgroup. The variability of immunoglobulins follows a structural principle in which the single point mutations responsible for the variability are linked. The present paper contains the exact analysis of the linked point mutations within the so far best-investigated subgroup, kappaI (12 completely sequenced proteins). These linked exchanges allow the arrangement of the kappaI proteins in 4 subgroups and their further subdivision. The regularity of this amino acid sequence pattern can only be explained by an evolutionary origin of antibody variability. On the basis of this evolutionary mechanism the relationship of immunoglobulins can be depicted in a phylogenetic tree. Such a tree was therefore constructed for the 18 completely determined Bence-Jones proteins of kappa-type, for the first time taking into account Bence-Jones protein Len. Its topology is in complete agreement with the results of the comparative sequence analysis.

Amino Acid Sequence↗
PubMed1976

The metabolic activation of the carcinogen 1'-hydroxysafrole in vivo and in vitro and the electrophilic reactivities of possible ultimate carcinogens.

Administration of [2',3'-3H]-1'-hydroxysafrole to rats or mice resulted in the formation of hepatic DNA-, ribosomal RNA-, and protein-bound 3H derivatives. Alkaline digestion of the 3H-protein released 0.1 to 0.3% of the 3H as a derivative that was identified as 3'-methylmercaptoisosafrole by its cochromatography in five solvent systems with the synthetic compound. 1'-Hydroxysafrole was metabolized at a low rate by rat and mouse liver cytosols in a 3'-phosphoadenosine 5'-phosphosulfate-dependent reaction to a derivative (presumably the sulfuric acid ester) that was captured by its reaction with RNA. Likewise, 1'-hydroxysafrole was oxidized at a low rate by rat and mouse liver microsomes to 1'-hydroxysafrole-2',3'-oxide in a reduced nicotinamide adenine dinucleotide phosphate-dependent reaction. Both of these electrophilic metabolites are candidate ultimate carcinogenic derivatives of 1'-hydroxysafrole. The electrophilic reactivities of various safrole derivatives with nucleosides were determined to be in the order of 1'-oxosafrole greater than 1'-acetoxysafrole greater than 1'-acetoxysafrole-2',3'-oxide greater than 1'-hydroxysafrole-2',3'-oxide greater than safrole-2',3'-oxide greater than or equal to 1'-oxosafrole-2',3'-oxide. The major reactions were generally observed with guanosine. A major reaction product of 1'-acetoxysafrole and guanosine 5'-monophosphate yielded 3'-hydroxyisosafrole under very mild acidic conditions. These data further substantiate the previous characterization of this reaction product as O-6-(isosafrol-3'-yl)guanylic acid. The syntheses of 1'-oxosafrole, 2',3'-dehydrosafrole, [2',3'-3H]-1'-hydroxysafrole, and the 2',3'-oxed.

Acetyltransferases↗
PubMed1976

[Disadvantages of acid precipitation of proteins during the assay of blood glucose by the enzymatic glucose oxidase-peroxidase system].

In the enzymatic procedure for blood sugar by means of glucose oxidase, acid protein precipitation of blood by perchloric acid or trichloracetic acid liberated oxidizing substances, which enhanced the coloration density in oxidizing the reduced chromogen of the reaction mixture, independently of the hydrogen peroxide generated from glucose, and would give false high values of glycemia, if additional precautions had not been taken. These substances, increasing considerably with times and temperature of blood conservation, would be of peroxide nature, and would accumulate in red blood cells during their exposure to air.

Animals↗