| the effect of substrate analogs on the circular dichroic spectra of thymidylate synthetase from lactobacillus casei. | circular dichroism studies from 290 to 400 nm with the thymidylate synthetase from lactobacillus casei revealed characteristic cotton effects in the presence of various folate analogs plus 5-fluoro-2'-deoxyuridylate. omission of either substrate analog prevented the appearance of the cotton effects. when 5-fluoro-2'-deoxyuridylate and (+/-)-5,10-methylenetetrahydrofolate are mixed with the synthetase, a ternary complex results which yields distinctive minor negative ellipicity bands at 285 and 3 ... | 1975 | 807243 |
| interaction of deoxyuridylate with thymidylate synthetase. | the reaction of deoxyuridylate with lactobacillus casei thymidylate synthetase (methylenetetrahydrofolate: deoxyuridylate c-methyltransferase) in the absence of folate or thiols can be followed by changes in the circular dichroic spectra at 267 nm. these changes at the maximum absorption wavelength of the pyrimidine suggest that on binding the interaction of the pyrimidine ring and the deoxyribose moiety is altered. the binding curve follows the form expected for single site binding. there was n ... | 1975 | 807570 |
| folate concentration and pattern in bovine milk. | | 1975 | 807607 |
| synthesis of a fluorescent derivative of amethopterin,. | fluorescein isothiocyanate was treated with excess diaminopentane and the remaining unsubstituted amino group of the product was condensed, via a carbodiimide-promoted reaction, with a carboxyl group of amethopterin. the final product, a fluorescent derivative of amethopterin, was isolated by chromatography on ae-cellulose and preparative electrophoresis on polyacrylamide. it was shown to be homogeneous by analytical polyacrylamide electrophoresis and thin-layer chromatography. proof of structur ... | 1975 | 807734 |
| synthesis and biological activity of 10-thia-10-deaza analogs of folic acid, pteroic acid, and related compounds. | the 10-thia analogs of pteroic acid, folic acid, their esters, and their 4-amino analogs were synthesized through a reaction sequence involving, as a key step, the condensation of 2-amino-3-cyano-5-chloromethylpyrazine with appropriately substituted thiols. the abilities of the products to inhibit the growth of methotrexate (mtx)-sensitive and mtx-resistant microorganisms were investigated as were their abilities to inhibit dihydrofolic acid reductase and thymidylic acid synthetase. several comp ... | 1975 | 808608 |
| presence of fine spirals (spirosomes) in lactobacillus fermenti and lactobacillus casei. | | 1975 | 809611 |
| radioassay of serum folate with use of pig plasma folate binders. | pig plasma has been used as a source of specific folate binders for the development of a rapid radioassay to measure the concentration of folate in serum. the assay uses 3h-pteroylglutamic acid as tracer and n-5-methyltetrahydrofolic acid for the construction of the standard curve. the assay is run in a two-step incubation system of 15 min each at room temperature. comparison between the results obtained with this method and a microbiological one indicated that for sera with relatively high fola ... | 1975 | 809969 |
| [bacteriocinogeny in lactobacilli of the subgenus streptobacterium]. | bacteriocinogenic properties of 145 strains of l. casei and 23 strains of l. plantarum were studied by the method of delayed antagonism. the capacity for producing bacteriocins was observed in 2 per cent of l. casei and 26 per cent of l. plantarum. the bacteriocins of l. casei and l. plantarum were preliminarily divided into 3 and 2 types respectively by their activity against lactobacilli of different species and the character of the growth inhibition zones of the indicator strain. | 1975 | 810075 |
| competitive protein binding assay for methotrexate. | a competitive protein binding assay has been developed for methotrexate based on the tight binding of this drug to lactobacillus casei dihydrofolate reductase (= tetrahydrofolate dehydrogenase; 5,6,7,8-tetrahydrofolate: nadp+ oxidoreductase; ec 1.5.1.3). free drug may be separated from that bound to reductase by adsorption with dextran--albumin coated charcoal. scatchard plot analysis of the enzyme--drug interaction confirmed the presence of a single homogeneous class of binding sites with an as ... | 1975 | 810804 |
| amino acid analogs. iii: new syntheses of monomethyl- and monophenylglutamic acids. | glutamic acid analogs containing 3- and 4-methyl and 2-, 3-, and 4-phenyl substituents were prepared. the 3- and 4-methyl- and 3- and 4-phenylglutamic acids did not inhibit plasmodium berghei and were nontoxic to the host (mice) at 640 mg/kg. the five analogs in addition to 2-methlglutamic acid were inactive against lactobacillus casei at 1000 mug/ml in a defined medium: against escherichia coli, only 2-methylglutamic acid caused 27% inhibition at 10,000 mug/ml. all six analogs failed to inhibit ... | 1975 | 811786 |
| [serological characteristics of lactobacillus casei var. rhamnosus]. | | 1975 | 811828 |
| [ability of lactobacilli in the human microflora to produce lysozyme]. | lysozyme activity of 403 strains of lactobacilli were investigated; of these 26 were from foreign sets and 377 were isolated from the contents of the stomach, feces and vaginal discharge of healthy adults. the species reference of lactobacillae was confirmed by the results of study of their physiologo-biochemical properties with the aid of 45 tests. a method of agar plates was adapted to determination of lysozyme: the autoclaved suspension of micrococcus lysodeikticus (strain no. 2665) was added ... | 1975 | 812310 |
| thymidylate synthetase catalyzed dehalogenation of 5-bromo-and 5-iodo-2'-deoxyuridylate. | | 1975 | 812499 |
| the effect of medium redox potential on the folate-limited growth of lactobacillus casei var. rhamnosus. | the medium redox potential (eh) influenced the folate-limited growth of lactobacillus casei; the growth response was maximal at an eh of +120 mv (ph 6-35). at raised eh serum folate would support less growth than pteroylglutamic acid, and the response to n5-methyl tetrahydrofolic acid was intermediate between them. pteroylglutamic acid was not destroyed during 24 h incubation at 37 degrees c in medium with eh values between +40 and +440 mv. destruction of n5-methyl tetrahydrofolic acid occurred ... | 1976 | 812947 |
| urease activity in the rumen of sheep and the isolation of ureolytic bacteria. | urease activity in the sheep rumen varied with the diet of the sheep, but appeared to be largely or entirely present in the small bacterial fraction. screening of over 1000 strains of rumen bacteria isolated on different media showed that urease activity was apparently confined to species of staphylococcus, lactobacillus casei var. casei and klebsiella aerogenes. consideration of the numbers in which these occurred and their activities suggested that the bacteria could not be responsible for the ... | 1976 | 812952 |
| [folacin determination in the blood by a fluorimetric method]. | to determine the blood folacin a fluorometric method is proposed. this includes the following stage-wise operations: liberation of combined forms of folacin under the effect of enzymes contained in the blood investigated; quantification of tyrosine to make a correction for changed fluorescence intensity of this amino acid during oxilation of the solution; measurement of the fluorescence of the substances present in the solution before and after their oxidation with potassium permanganate and cal ... | 1975 | 813383 |
| factors affecting substrate binding in lactobacillus casei thymidylate synthetase as studied by equilibrium dialysis. | the binding of deoxynucleoside 5'-monophosphates and various folate derivatives to lactobacillus casei thymidylate synthetase was measured by equilibrium dialysis. the substrate, deoxyuridylate (dump), and the product, thymidylate (dtmp), were bound to the enzyme at a ratio of unity and appeared to compete for the same site. the binding of each was tighter in 50 mm tris-hcl (ph 7.1) than in 50 mm potassium phosphate (ph 7.0). folate derivatives increased the affinity of the enzyme for the substr ... | 1976 | 813762 |
| the effect of diphenylhydantoin on the microbial assay of serum folate. | 1. two modifications fo the usual method of assay for folic acid in solutions are reported which appear to improve this procedure. these are a reduction of incubation time and dilution with 95% ethanol. 2. experimental results are reported which indicate that dilantin (5,5-diphenylhydantoin) does not interfere with the microbiological assay for folic acid. | 1976 | 813913 |
| interaction of 13c-enriched folate with dihydrofolate reductase studies by carbon magnetic resonance spectroscopy. | | 1976 | 814898 |
| formation of ternary complexes of thymidylate synthetase as followed by absorbance, fluorescence, and circular dichroic spectra and gel electrophoresis. | ternary complexes of thymidylate synthetase (form ii and form iii), which are composed of the enzyme, 5-fluorodeoxyuridylate, and the natural isomer of methylenetetrahydrofolate, were generated by titrating thymidylate synthetase (form i) in the presence of 5-fluorodeoxyuridylate with either the enzymatically prepared natural isomer or the chemically prepared racemic mixture of the diastereomers of methylenetetrahydrofolate. such titrations were monitored by absorption, circular dichroic and flu ... | 1976 | 815255 |
| folate transport in lactobacillus casei: solubilization and general properties of the binding protein. | | 1976 | 816354 |
| functional arginine residues involved in coenzyme binding by dihydrofolate reductase. | | 1976 | 816356 |
| the clinical value of the radioassay of serum folate. | measurement of serum folate levels in humans using a radioassay has now been frequenly reported. however, very little data is available assessing the diagnostic value of this test in comparison with other laboratory and clinical information pertaining to folate status. a radioassay, using the folate binder in dried milk was used in parallel with the well established lactobacillus casei microbiological assay. three slightly different modifications of the radioassay were tested. at first, a partia ... | 1976 | 818326 |
| beta-hydroxynorleucine: separation of its isomers and biological studies. | separation of the four isomers of beta-hydroxynorleucine was accomplished by partition column chromatography and asymmetric enzymatic hydrolysis of the n-chloroacetyl derivatives. from these, the corresponding n-chloroacetyl derivatives were made. the purity and configuration of each isomer of the free acid and n-chloroacetylated derivative were ascertained by: (a) paper chromatography in five solvent systems, (b) elemental analysis, (c) van slyke nitrous acid determination of alpha-carbonyl car ... | 1976 | 818362 |
| enzymatic assay for methotrexate in serum and cerebrospinal fluid. | we describe an assay for methotrexate in biological fluids. the assay is based on inhibition by methotrexate of dihydrofolate reductase from lactobacillus casei. the lower limit of sensitivity in serum is 2 x 10(-8) mol (about 10 mug) of methotrexate per liter. within-run precision is +/- 5% (coefficient of variation) and day-to-day variation is 18%. advantages of the assay are ease of manipulation, high sensitivity, and specificity. | 1976 | 819184 |
| transport and utilization of methyltetrahydrofolates by lactobacillus casei. | transport of labeled 5-methyltetrahydrofolate (5-methyl-h4pteglu) and 5-methyl-h4pteglu5 by lactobacillus casei was via a carrier-mediated system. both the natural (l) and unnatural (d) diastereoisomers were transported. active transport was only demonstrated with the monoglutamate. comparisons of growth rates with transport rates demonstrated that pteroypolyglutamates were more effectively utilized by l. casei than the monglutamate derivatives. the rate-limiting step in the utilization of highe ... | 1976 | 819430 |
| effect of sonic treatment on pure cultures and aggregates of bacteria. | pure cultures of a variety of bacteria were treated with ultrasonic energy using a sonic probe. fractions of organisms killed at different sonic energies were calculated, and streptococcus mutans was 600 times more resistant than fusobacterium nucleatum, the most sensitive organism tested. the effects of sonic treatment on aggregates of bacteria were examined, and the results were interpreted as a model of the events that probably occur during the sonic dispersion of dental plaque. | 1976 | 819454 |
| isolation of lipoteichoic acids from butyrivibrio fibrisolvens. | lipoteichoic acid (lta) and deacylated lipoteichoic acid have been isolated from the bovine-rumen gram-negative anaerobe butyrivibrio fibrisolvens by phenol extraction. lipoteichoic acid (21.8 mumol phosphorus/g cells) consisted of a conventional 1, 3-phosphodiester-linked chain of glycerol phosphate units joined covalently to a glycolipid. it was not substituted with glycosyl or d-alalyl ester groups. deacylated lipoteichoic acid (57.5 mumol phosphorus/g cells) was similar in constitution but l ... | 1976 | 819620 |
| determination of erythrocyte vitamin b12 activity. | data presented in this paper show that there is no significant difference between plasma and serum vitam b12 activity when edta is used as the anticoagulant. by drawing 5 ml of blood into a tube containing edta, the whole blood and plasma b12 activity can be measured using lactobacillus leichmannii for the assay as the test organism. erythrocyte b12 levels can be obtained by difference after correcting for hematocrit. sodium heparin appears to inhibit the growth of l. leichmannii. | 1976 | 820180 |
| thymidylate synthetase: studies on peptide containing covalently bound 5-fluoro-2'-deoxyuridylate and 5,10-methylenetetrahydrofolate. | | 1976 | 820346 |
| [rate of disappearance of phagocytized bacteria from polymorphonuclear cells]. | | 1976 | 820361 |
| [changes in the phagocytic capacity of polymorphonuclear cells after remaining in test tubes and after adhesion to a surface]. | | 1976 | 820362 |
| reaction of dihydrofolate reductase with dansyl chloride. chemical modification of a sensitive lysine residue and fluorometric studies of the dansylated enzyme. | dihydrofolate reductase from amethopterin-resistant lactobacillus casei is virtually completely and irreversibly inactivated by relatively low concentrations of dansyl chloride. the complete inactivation can be correlated with the dansylation of a single lysine residue and ca. 90% quenching of protein fluorescence. this quenching phenomenon appears to be due, at least in part, to energy transfer from one or more excited state tryptophan residues to the covalently attached dansyl moiety. under id ... | 1976 | 820367 |
| folate analogues altered in the c9-n10 bridge region. 10-oxafolic acid and 10-oxaaminopterin. | the unambiguous synthesis of two folate analogues, in which the 10-amino group of folic acid was replaced with oxygen, is described. the synthetic sequence employed commercially available methyl p-hydroxybenzoate and n-(2,3-epoxypropyl)phthalimide as starting materials. the use of cesium bicarbonate as a coreactant in the nucleophilic displacement reaction between bromo ketone 3 and the nucleophile 4 was found to be unique in character. the aminoacetonyl oxime 7 obtained by the hydrazinolysis of ... | 1976 | 820858 |
| evidence for extrachromosomal elements in lactobacillus. | three strains of lactobacilli, lactobacillus casei subsp. casei 64h, l. casei subsp. rhamnosus oc91, and l. coryniformis m34, were examined for the presence of plasmids. plasmids of molecular weights of 23 x 10(6) and 16 x 10(6) were found in the first two strains respectively. this represents the first evidence for plasmids in lactobacilli; their function is not presently known. | 1976 | 821936 |
| demonstration of separate binding sites for the folate coenzymes and deoxynucleotides with inactivated lactobacillus casei thymidylate synthetase. | | 1976 | 822852 |
| folate radioassay and crude milk binder. | | 1976 | 822901 |
| purification, properties and immunological relationship of l (+)-lactate dehydrogenase from lactobacillus casei. | the fructose-1,6-bisphosphate-activated l-lactate dehydrogenase (ec 1.1.1.27) from lactobacillus casei atcc 393 has been purified to homogenity by including affinity chromatography (cibacronblue-sephadex-g-200) and preparative polyacrylamide gel electrophoresis into the purification procedures. the enzyme has an mr of 132000-135000 with a subunit mr of 34000. the ph optimum was found to be 5.4 insodium acetate buffer. tris/maleate and citrate/phosphate buffers inhibited enzyme activity at this p ... | 1976 | 823016 |
| chromatography of folates on sephadex g-10. | folates have been separated on columns of sephadex g-10 using spectrophotometric and microbiological detection with lactobacillus casei. the method is suitable especially for the separation of folic acid from other folates, and of dihydrofolic acid derivatives from their tetrahydrofolic acid forms. distribution constants of seven standard folates have been determined. the method has been applied to the determination of folates in cow's milk. chromatographic separation of conjugase treated and un ... | 1976 | 823166 |
| serum folate levels. comparison of microbiologic assay and radioisotope kit methods. | serum folate levels were measured prospectively in 72 patients and six normal controls using the lactobacillus casei microbiologic method and a commercially available sequential-binding radioassay kit method. values between 0 and 14 ng/ml (0 and 31.78 nmol/l) (clinically significant range) obtained by the microbioassay and sequential-binding radioassay were analyzed statistically. the data suggest that comparable values are obtained by the two technics (y = 0.9 x where y = radioassay value). dat ... | 1976 | 823817 |
| production of mannitol by streptococcus mutans. | | 1976 | 823929 |
| glycerol dissimilation and its regulation in bacteria. | | 1976 | 825019 |
| thymidylate synthetase: fluorine-19 nmr characterization of the active site peptide covalently bound to 5-fluoro-2'-deoxyuridylate and 5,10-methylenetetrahydrofolate. | | 1976 | 825116 |
| [sensitivity of the lactobacilli of the subgenus streptobacterium to bacteriocins of lactobacilli of different species]. | sensitivity of 167 cultures of lactobacilli of streptobacterium to 39 bacteriocins produced by l. acidophilus, l. jugurti, l. salivarius, l. lactis, l. helveticus, l. casei, l. plantarum, l. fermenti, l. brevis and l. buchneri was studied. it was found that the cultures of l. casei were sensitive to 30 types of bacteriocins, while the cultures of l. plantarum were sensitive to 9 bacteriocin types. 89.6 per cent of the cultures of l. casei and all cultures of l. plantarum were sensitive to one or ... | 1976 | 826216 |
| the effect of the exogenous folate concentration on the biosynthesis of pteroylpolyglutamates in lactobacillus casei and the folate polyglutamate distribution in escherichia coli. | | 1976 | 826429 |
| the identification of the intracellular folate coenzymes of different cell types. | | 1976 | 826433 |
| delay in metabolism of parenteral folinic acid to 5-methyltetrahydrofolate in man. | | 1976 | 826436 |
| folate coenzyme forms in fibroblasts from patients deficient in 5,10-methylenetetrahydrofolate reductase. | | 1976 | 826437 |
| purification of thymidylate synthetase by means of affinity chromatography on tetrahydroamethopterin-aminoethyl-sepharose. | | 1976 | 826438 |
| [decomposition of grass-fructosanes by lactobacilli from silage (author's transl)]. | lactobacilli isolated from grass silage were shown to belong to lb. plantarum, lb. casei and lb. brevis. in studies on the degradation of fructosanes significant differences among the three species were found. while all strains of l. casei were able to degrade fructosanes from dactylis glomerata or phleum pratense regardless of the degree of polymerization, no nember of lb. plantarum or lb. brevis could attack these polysaccharides. | 1976 | 827143 |
| [bacteriocin typing of lactobacilli of the streptobacterium subgenus]. | sensitivity of 144 l. casei cultures and 23 l. plantarum cultures to the action of 39 bacteriocins produced by lactobacillae of different species was studied by the method of delayed antagonism. by the bacteriocin sensitivity the l. casei cultures were subdivided into 37 and l. plantarum cultures--into 7 bacteriocin types. the method of bacteriocin typing permitted differentiation of the l. casei and l. plantarum cultures, which had the same biochemical and physiological properties, as a number ... | 1976 | 827162 |
| fluorescence study of guanidine hydrochloride denaturation of thymidylate synthetase. | | 1976 | 827292 |
| [elimination from the digestive tract of a "gnotoxenic" child of a "lactobacillus casei" strain, isolated from a commercial preparation: antagonistic effect of an "escherichia coli" strain of human origin, demonstrated in "gnotoxenic" mice (author's transl)]. | a strain of lactobacillus casei from a pharmaceutical preparation became established in the digestive tract of an axenic child. it was eliminated by the first bacteria occurring after inoculation of the child's digestive tract with a human flora, before the child was taken out of the isolator. using "gnotoxenic" mice, we found that the elimination of l. casei was due to a bactericidal effect of the escherichia coli of human origin, within the digestive tract. | 1976 | 828463 |
| the significance of the 'free' folate content of foods is questioned [proceedings]. | | 1976 | 829282 |
| [relationship between a fermented milk beverage and factors involved in dental caries formation]. | | 1975 | 829778 |
| long-term of phenytoin: effects on whole blood and red cell folate and haematological parameters. | patients treated when phenytoin for periods of several months or years have slightly, but significantly lower whole blood and red cell folate values than comparable controls. this holds true irrespective of whether folate is determined microbiologically with lactobacillus casei or by a radioligand method using the bovine milk binder. haematological parameters including hb, mch, mcv and red blood cell counts did not show any alterations and no patient developed any signs of anaemia. this indicate ... | 1977 | 841272 |
| relationship of cytochrome content to the sensitivity of bacteria to nacl on freezing and thawing. | eight species of bacteria representing rod, coccus, gram-positive, and gram-negative forms were tested for their sensitivity to sodium chloride during freezing and thawing. six of the eight species tested were salt-sensitive, though to different degrees, while lactobacillus casei and streptococcus faecalis were resistant. escherichia coli grown anaerobically exhibited only 38% of the salt sensitivity of aerobically grown cells. analysis of cytochrome pigments in the organisms revealed that the s ... | 1977 | 861847 |
| evidence for frequent lysogeny in lactobacilli: temperate bacteriophages within the subgenus streptobacterium. | a total of 17 of 21 lactobacillus strains of the subgenus streptobacterium were lysogenic. two different temperate phages isolated from such lysogens are very similar to lactobacillus casei phage pl-1. the narrow host range of bacteriophage pl-1 appears to be caused by homoimmunity. | 1977 | 916033 |
| folate levels among various populations in central iran. | serum folic acid levels (lactobacillus casei assay) were determined in 467 subjects representing various socioeconomic classes from rural and urban central iran. of the subjects 170 were pregnant females in different trimesters. the mean serum folate levels of the various groups studied ranged from 7.5 to 11.1 ng/ml and are within the normal reported range of 5.9 to 21.0 ng/ml. only two subjects had serum folate levels below 3.0 to 5.9 ng/ml. in anemic subjects (hematocrit is less than 37%), red ... | 1976 | 937234 |
| folic acid binding protein and folate balance in uremia. | to determine the incidence and importance of folate deficiency in uremia, we studied 41 patients who had chronic uremia but who were not receiving hemodialysis. serum folate level was assayed by microbiological, whole serum radioassay, and heat-extracted radioassay techniques. mean serum folate level, as determined with the lactobacillus casei method, was 6.9 ng/ml (normal, more than 3.0 ng/ml). the mean heat-extracted radioassay serum folate level was 6.6 ng/ml. only 10% of our patients had sub ... | 1976 | 938164 |
| amino acid sequence at the fdump binding site of thymidylate synthetase. | cyanogen bromide treatment of thymidylate synthetase of lactobacillus casei, which had been converted to a ternary complex with [2-14c] fdump and 5,10-methylene-tetrahydrofolate followed by s-carboxymethylation, yielded at least four visible peptide bands, the largest with a molecular weight of about 13,000, on polyacrylamide gel electrophoresis in sodium dodecyl sulfate-urea. identical results were obtained with enzyme that had all four of its cysteinyl residues s-carboxymethylated with iodo [i ... | 1976 | 1064857 |
| partial purification and properties of an enzyme from escherichia coli that catalyzes the conversion of glutamic acid and 10-formyltetrahydropteroylglutamic acid to 10-formyltetrahydropterol-gamma-glutamyglutamic acid. | an enzyme that catalyzes the conversion of l-glutamic acid and 10-formyl-h4folic acid (also known as 10-formyl-h4pteroylglutamic acid) to 10-formyl-h4pteroyl-gamma-glutamylglutamic acid has been purified by 74-fold from extracts of escherichia coli. atp, mg-2+, and a monovalent cation (k+ or nh-4, but not na+) are required for the enzyme to function. radioactive and bioautographic analyses revealed the formation of a single product. this product was identified as 10-formyl-h-4pteroyl-gamma-gluta ... | 1975 | 1095054 |
| the effect of oral contraceptives on folate metabolism. iii. plasma clearance and urinary folate excretion. | the plasma clearance of folic acid (pga) and urinary excretion of folates were determined in women on oral contraceptives and in control subjects. the initial phase of plasma clearance of pga (first 5 minutes) was much faster in oral contraceptive users than in the controls, but the subsequent rate of clearance was the same in the two groups. there was a good correlation between the 12-hour urinary folate excretion and serum or red cell folate in both groups. the women on oral contraceptives exc ... | 1975 | 1113011 |
| harmful effect of megadoses of vitamins: electroencephalogram abnormalities and seizures induced by intravenous folate in drug-treated epileptics. | folic acid was administered intravenously during constant eeg monitoring to eight epileptic subjects who had received diphenylhydantoin therapy for more than 1 year. six of the subjects displayed low folate levels by lactobacillus casei assay in plasma and/or whole blood. six patients received 75 mg of folate intravenously over a 30-min period without clinical effect of eeg change. one patient exhibited an increase in spike discharges on the eeg in comparison to the baseline pattern, but no clin ... | 1975 | 1115018 |
| formation of extracellular lipoteichoic acid by oral streptococci and lactobacilli. | examination of the culture fluids from a number of strains of oral streptococci and latobacilli has shown the presence of an erythrocyte-sensitizing antigen with the properties of lipoteichoic acid. the antigen was isolated from the culture fluids of lactobacillus casei and lactobacillus fermentum and characterized chemically and serologically, for other strains, serological evidence for the presence of lipoteichoic acid depends on the reactivity with antiserum specific for the glycerol phosphat ... | 1975 | 1158524 |
| oral contraceptives, serum folate, and hematologic status. | previous reports have suggested deleterious effects on folate balance in users of contraceptives. a study of folate in 526 women attending a family-planning clinic demonstrated, both with the lactobacillus casei assay and with a new radioassay, that the mean serum folate level for women taking oral contraceptives was not significantly lower than that for women in a control group. there was no correlation between serum folate level and length of time oral contraceptives were taken. also, there wa ... | 1975 | 1172864 |
| clinical and laboratory observations on serum folate-binding protein. | we studied the effect of serum folate-binding protein (fbp) on folate radioassays and the relationship of the serum level of unsaturated fbp to the serum folate level in various clinical states. our modification of a heat-extracted radioassay was compared to a whole serum radioassay. our results confirmed the existence of elevated serum levels of unsaturated fbp in some normal subjects, in some women taking oral contraceptives, and in most patients with uremia. elevated levels of unsaturated fbp ... | 1975 | 1174694 |
| metabolism of dihydroaminopterin and the influence of aminopterin and related derivatives on the metabolism of (-)-5-formyl-tetrahydrofolic acid in pediococcus cerevisiae. | [3h]dihydroaminopterin, but not [3h]methotrexate or [3h]aminopterin, was rapidly taken up by resting cell of pediococcus cerevisiae and inhibited the uptake of (-)-5-formyl-tetrahydrofolic acid to more than 90% at a concentration of 25 mum. on the other hand 5-formyl-tetrahydrofolic acid inhibited the uptake of dihydroaminopterin to a similar extent. dihydroaminopterin was metabolized by pediococcus cerevisiae, but not by lactobacillus casei, to a compound tentatively identified as dihydroaminop ... | 1976 | 1247588 |
| the effect of raney nickel on the covalent thymidylate synthetase-5-fluoro-2'-deoxyuridylate-5,10-methylenetetrahydrofolate complex. | raney nickel (ni(h)) catalyzes a specific reductive cleavage of carbon-sulfur bonds and, therefore, can be used to determine whether compounds are covalently bound to proteins through a sulfide linkage. when the covalent thymidylate synthetase-[3h]5-fluoro-2'-deoxyuridylic acid-[14c]-5,10-ch2h4-folate complex (langenbach et al. (1972a), biochem, biophys. res. commun. 48, 1565) was denatured and then shaken with ni(h) at 25 degrees c, both isotopes were rapidly cleaved from the protein, with iden ... | 1976 | 1252451 |
| a study of the growth inhibition of lactobacillus casei by n-alkyl homologs of n-nitro-n-nitrosoguanidine. | n-methyl-(mnng), n-ethyl-(enng), and n-propyl-(pnng) derivatives of n'-nitro-n-nitrosoguanidine inhibited the growth of lactobacillus casei in the order of potency, mnng greater than enng greater than pnng. l-cysteine, gluathione, and dithioerythritol reversed the inhibition on a molar basis. the -sh compounds accelerated the loss of the n-nitroso group in vitro, yielding non-inhibitory n-alkyl nitroguanidines. the significance of the loss of the nitroso group and the size of the n-alkyl group i ... | 1976 | 1253336 |
| irreversible inhibition of thymidylate synthase by pyridoxine (b6) analogues. | three vitamin b6 analogues have been synthesized and tested as inhibitors of thymidylate synthase. the compounds are: 4',5'-dichloro-, 4',5'-dibromo- and 4',5'-diiodo-pyridoxine. all three analogues inhibited the enzyme irreversibly. the kinetic data for the chloro- and bromo-analogues showed that a limiting rate of inhibition is approached as the inhibitor concentration is increased, which indicates that a reversible enzyme:inhibitor affinity complex is formed prior to the irreversible reaction ... | 1992 | 1284431 |
| 1-phenyl-3-trimethylaminopropyl carbodiimide: a new inhibitor of thymidylate synthase. | thymidylate synthase (ec 2.1.1.45) from methotrexate-resistant lactobacillus casei was inactivated by 1-phenyl-3-trimethylaminopropyl carbodiimide (ptc), 1-phenyl-3-dimethyl aminopropyl carbodiimide (pdc), and 1-ethyl-3-dimethyl aminopropyl carbodiimide (edc). in the presence of excess ptc, the inactivation followed pseudo-first order kinetics; the second order rate constant was approximately 200 m-1min-1 at 30 degrees c. the rate of inactivation by ptc was faster than that by either pdc or edc. ... | 1992 | 1285247 |
| effects of cultured milk products by lactobacillus and bifidobacterium species on the secretion of bile acids in hepatocytes and in rats. | whey preparations prepared from cultured milk by 19 lactobacillus (2 species) and 20 bifidobacterium (5 species) strains were examined for the effects of secretion and synthesis of bile acids in primary cultured rat hepatocytes. the stimulating effect of whey preparation on bile acid secretion depended on the species as well as the strains used for milk fermentation. two strains belonging to l. casei sbt 2230 (lc2230) and b. longum sbt 2912 (bl2912) produced the whey which stimulates both the se ... | 1992 | 1291639 |
| membrane transport of folate compounds. | all eukaryotic cells and some prokaryotes that are unable to synthesize folic acid utilize membrane-associated transport systems for acquisition of the pre-formed vitamin or its coenzyme forms from external sources. these transport systems, in addition to providing folates essential for cell replication, are also important because of their role in the internalization of antifolates such as methotrexate (mtx) that are used extensively in cancer chemotherapy. information about the components and m ... | 1992 | 1297801 |
| fatal lung abscess due to lactobacillus casei ss rhamnosus. | a fatal case of community acquired pneumonia due to lactobacillus casei ss rhamnosus is reported. clinicians should be aware of this type of pneumonia. | 1992 | 1298232 |
| [effect of glucose and lactose on the utilization of citrate by lactobacillus casei subsp. rhamnosus atcc 7469]. | the utilization of citrate by lactobacillus casei subsp. rhamnosus atcc 7469 in a complex medium containing glucose, lactose or citrate was investigated, as an approach to the question of the transport of this acid and the possible relationship with the production of flavour compounds (diacetyl and acetoin). this lactobacillus uses citrate as an energy source in the absence of carbohydrates. external ph and growth increases when citrate is added to complex medium. the presence of citrate does no ... | 1992 | 1302866 |
| [histological study of the structure of artificial plaque]. | five cariogenic bacteria were used to produce a plaque, called artificial plaque, by sequential culture in vitro. the results showed that the artificial plaque is very similar to the natural one in morphology and structure. artificial plaque may be taken as an excellent model in vitro for the studies on cariogenicity of dental plaque. | 1992 | 1304541 |
| reversible dissociation and unfolding of the dimeric protein thymidylate synthase. | conditions for in vitro unfolding and refolding of dimeric thymidylate synthase from lactobacillus casei were found. ultraviolet difference and circular dichroism spectra showed that the enzyme was completely unfolded at concentrations of urea over 5.5 m. as measured by restoration of enzyme activity, refolding was accomplished when 0.5 m potassium chloride was included in the refolding mixture. recombination of subunits from catalytically inactive mutant homodimers to form an active hybrid dime ... | 1992 | 1304920 |
| hydrogen peroxide production by lactobacillus species: correlation with susceptibility to the spermicidal compound nonoxynol-9. | facultative anaerobic lactobacilli were recovered from the vaginas of 96.8% of 63 nonpregnant, healthy, premenopausal women. the predominant species were lactobacillus jensenii, lactobacillus acidophilus, and lactobacillus casei. of the women, 74.6% had hydrogen peroxide-producing lactobacilli, 22.2% had non-hydrogen peroxide-producing lactobacilli, and 3.2% had no lactobacilli. none of the 68 isolates had catalase activity. some 68.2% of the isolates were inhibited by concentrations of less tha ... | 1992 | 1316413 |
| humoral igg antibodies to oral microbiota in a population at risk for root-surface caries. | mutans streptococci have been strongly implicated in the initiation of dental caries on coronal surfaces. their role in development of root-surface caries is less clear. the etiologic agents of both types of dental caries are likely to elicit systemic immune responses. the objective of the present study, therefore, was to study the association of clinical variables of disease with humoral igg antibodies to nine oral micro-organisms in 314 adult subjects, aged 45-65 years, who were at risk for ro ... | 1992 | 1321176 |
| distribution of tnf endogenously induced by various immunopotentiators and lactobacillus casei in mice. | intravenous administration of heat-killed lactobacillus casei yit 9018 (lc) elicited endogenous cytotoxic factor (cf) production in icr mice, peaking in serum after 2 h and declining gradually to basal level at 23 h. the endogenous cf production was significantly enhanced by priming with high molecular-weight lignins and glucans, but not by phenylpropenoid precursors or partially hydrolyzed products of glucans. the extent of stimulation of cf production by these priming agents was positively rel ... | 1992 | 1327255 |
| purification methods for recombinant lactobacillus casei thymidylate synthase and mutants: a general, automated procedure. | general procedures for the rapid, large-scale purification of recombinant lactobacillus casei thymidylate synthase and its mutants have been established. an effective method employs sequential phosphocellulose and hydroxylapatite chromatography. crude cell extracts are directly applied to phosphocellulose, and the enzyme is obtained in a nearly pure state by stepwise elution with kcl. the eluate is directly applied to hydroxylapatite, and the homogeneous enzyme is eluted with a gradient of potas ... | 1992 | 1333860 |
| antimicrobial effect of a dental varnish, in vitro. | the effects of a polymer based antimicrobial releasing varnish cervitec were investigated against different gram-positive and gram-negative bacterial strains as well as a yeast using the agar diffusion inhibitory test (adt-test in vitro). as positive controls a 1% chlorhexidine gel and 1% aqueous solution of thymol and a placebo polymer varnish without active agents were employed. the test experimental varnish containing 1% chlorhexidine and 1% thymol showed antimicrobial activity against all gr ... | 1992 | 1336221 |
| cloning and expression of the lysostaphin gene in bacillus subtilis and lactobacillus casei. | the lysostaphin structural gene was cloned in bacillus subtilis dsm402 and in lactobacillus casei 102s. the gene was expressed in both organisms and active lysostaphin was released into the medium. lysostaphin produced by these organisms induced lysis of growing and heat inactivated staphylococci. expression in a protective starter organism is a prerequisite to produce lysostaphin in situ in fermenting foods and hence, to reduce the hygienical risk of staphylococcal food poisoning. | 1992 | 1367977 |
| effects of some l-rhamnosyl derivatives on the adsorption of phage pl-1 to the host lactobacillus casei. | | 1992 | 1368309 |
| fuzzy reasoning system for fault diagnosis of physiological activities in a cultivating process. | aiming at development of a system which supports cultivating operations, a method to diagnose physiological activities in a cultivating process is presented, and a fuzzy expert system for diagnosing lactobacillus casei cultivating process is implemented in this paper. this system can calculate specific rates of cell growth, substrate consumption, and product formation with measuring cell mass concentration, substrate concentration, and product concentration by using a turbidity sensor and hplc. ... | 1992 | 1368352 |
| protoplast transfection of lactobacillus casei by phage pl-1 dna. | polyethylene glycol (peg) mediated transfection of lactobacillus casei atcc 27092 protoplasts by phage pl-1 dna was done. the protoplasts were obtained by treatment with purified pl-1 phage n-acetylmuramidase in the presence of citrate. optimum conditions for transfection were 50% peg 4,000, 15 micrograms protamine sulfate/ml, 0.15 m sucrose, and 10 mm mgso4 in mr medium (ph 6.0). the extent of transfection was proportional to the amounts of dna added, and the greatest efficiency of transfection ... | 1990 | 1368552 |
| purification and characterization of an antihypertensive compound from lactobacillus casei. | antihypertensive compounds were purified from an extract of autologous lactobacillus casei cell lysates. the most effective compounds were polysaccharide-glycopeptide complexes, found in the cell wall. the average molecular weight was estimated as 180,000 from gel filtration using sephacryl s-300. the polysaccharide moiety of the complexes consisted of glucose, rhamnose, and galactose, whereas the glycopeptide moiety consisted of n-acetylglucosamine, n-acetylmuramic acid, asparagine, glutamine, ... | 1990 | 1368639 |
| counter-diffusion of lactose and lactic acid in kappa-carrageenan/locust bean gum gel beads with or without entrapped lactic acid bacteria. | the effective diffusion coefficient (de) and equilibrium partition factor (kp) for lactose and lactic acid in k-carrageenan (2.75% w/w)/locust bean gum (0.25% w/w) (lbg) gel beads (1.5-2.0 mm diameter), with or without entrapped lactobacillus casei subsp. casei (l. casei), were determined at 40 degrees c. results were obtained from transient concentration changes in well-stirred solutions of finite volume in which the beads were suspended. mathematical models of unsteady-state diffusion into and ... | 1992 | 1368894 |
| calcium requirement for protoplast transfection mediated by polyethylene glycol of lactobacillus casei by pl-1 phage dna. | the effects of some divalent cations on protoplast transfection mediated by polyethylene glycol of lactobacillus casei atcc 27092 by pl-1 phage dna in 50 mm tris-maleate buffer (ph 6.0) were investigated. the efficiency of transfection increased about 30 times in the presence of 10 mm ca2+. sr2+ increased the transfection rate as well, but ba2+, mn2+, and mg2+ did not. co2+ and zn2+ inhibited transfection. the simultaneous use of ca2+ and mg2+ increased the transfection efficiency. impairment of ... | 1992 | 1369080 |
| enzyme purification by immobilized metal ion affinity partitioning--application to d-hydroxyisocaproate dehydrogenase. | extraction and purification of d-2-hydroxyisocaproate dehydrogenase from lactobacillus casei has been studied by means of immobilized metal ion affinity partitioning (imap) in aqueous two-phase systems. the partition of the enzyme can be influenced strongly by inclusion of iminodiacetic acid as chelating ligand coupled to polyethylene glycol and loaded with cu2+ ions into the phase system. this applies to polyethylene glycol/dextran as well as polyethylene glycol/salt phase systems. an increase ... | 1992 | 1369240 |
| effect of diet on folates levels and distribution in selected tissues of the rat. | a technique for the extraction, purification and concentration of folates, followed by high performance liquid chromatography assay with fluorometric detection of the three principal derivatives (tetrahydrofolic, 5-methyl-tetrahydrofolic and formyl-tetrahydrofolic acids) has been applied to the determination of tissue folates in rats. the levels found are compared to those of the microbiological assay using lactobacillus casei. when rats were fed a diet containing 1 mg of folic acid per kg of fo ... | 1992 | 1380335 |
| biosynthesis of d-alanyl-lipoteichoic acid: cloning, nucleotide sequence, and expression of the lactobacillus casei gene for the d-alanine-activating enzyme. | the d-alanine-activating enzyme (dae; ec 6.3.2.4) encoded by the dae gene from lactobacillus casei atcc 7469 is a cytosolic protein essential for the formation of the d-alanyl esters of membrane-bound lipoteichoic acid. the gene has been cloned, sequenced, and expressed in escherichia coli, an organism which does not possess dae activity. the open reading frame is 1,518 nucleotides and codes for a protein of 55.867 kda, a value in agreement with the 56 kda obtained by electrophoresis. a putative ... | 1992 | 1385594 |
| comparative acid tolerances and inhibitor sensitivities of isolated f-atpases of oral lactic acid bacteria. | ph activity profiles and inhibitor sensitivities were compared for membrane atpases isolated from three oral lactic acid bacteria, lactobacillus casei atcc 4646, streptococcus mutans gs-5, and streptococcus sanguis nctc 10904, with, respectively, high, moderate, and low levels of acid tolerance. membranes containing f1f0 atpases were isolated by means of salt lysis of cells treated with muralytic enzymes. membrane-free f1f0 complexes were then isolated from membranes by detergent extraction with ... | 1992 | 1386211 |
| structural and functional analysis of two cryptic plasmids from lactobacillus pentosus md353 and lactobacillus plantarum atcc 8014. | the dna sequences of a 2.4 kb plasmid (p353-2) from lactobacillus pentosus md353 and a 1.9 kb plasmid (p8014-2) from lactobacillus plantarum atcc 8014 show 81.5% overall similarity. both plasmids carry elements (replication protein gene, plus-origin and minus-origin of replication), which are typical of plasmids that replicate via a rolling-circle mechanism of replication (rcr). direct evidence for an rcr mechanism was obtained by showing the accumulation of single-stranded plasmid intermediates ... | 1992 | 1387195 |
| isolation and complete sequence of the purl gene encoding fgam synthase ii in lactobacillus casei. | the purl gene from lactobacillus casei, encoding phosphoribosylformylglycinamidine synthase ii involved in the de novo synthesis of purines, was cloned and sequenced. the putative purl product of 741 amino acids (m(r) of 79,575) shows 25% and 53% identity to the homologous enzymes from escherichia coli and bacillus subtilis, respectively. in addition, partial sequences of two other pur genes (purq and purf) and a possible third gene (purc) were obtained. all these genes are organized in an opero ... | 1992 | 1398079 |
| nucleotide and deduced amino acid sequences of the lacr, lacabcd, and lacfe genes encoding the repressor, tagatose 6-phosphate gene cluster, and sugar-specific phosphotransferase system components of the lactose operon of streptococcus mutans. | the complete nucleotide sequences of lacrabcdf and partial nucleotide sequence of lace from the lactose operon of streptococcus mutans are presented. comparison of the streptococcal lac determinants with those of staphylococcus aureus and lactococcus lactis indicate exceptional protein and nucleotide identity. the deduced polypeptides also demonstrate significant, but lower, sequence similarity with the corresponding lactose proteins of lactobacillus casei. additionally, lacr has sequence homolo ... | 1992 | 1400164 |
| antibodies in normal and diseased pulps reactive with microorganisms isolated from deep caries. | immunoglobulin molecules in the supernatant fluids (sf) from pulpal explant cultures have been observed to react with microorganisms implicated in infections of root canals. in this study, the reactivity of immunoglobulin molecules in the sf from normal and irreversible pulpitis pulps to six strains of predominant microorganisms isolated from the immediate layer of carious lesions above the pulps used for explant cultures was investigated using an enzyme-linked immunosorbent assay. two atcc stra ... | 1992 | 1402561 |
| [the intestinal microflora of persons subjected to a radiation lesion]. | the content of large intestine has been studied in persons exposed to radiation injury in consequence of the accident at the chernobyl atomic power plant. it is stated that bifidobacteria (10(7)-10(10) cells in 1 g of feces) prevailed (as in healthy people), bifidobacterium indicum being a dominating species. amount of lactic-acid bacteria in 1 g of defecations of examined patients was within the range of 10(6)-10(9) cells and in certain persons it reached 10(10) cells (primarily fecal enterococ ... | 1992 | 1406381 |
| expression cloning of a human cdna encoding folylpoly(gamma-glutamate) synthetase and determination of its primary structure. | a human cdna for folypoly(gamma-glutamate) synthetase [fpgs; tetrahydrofolate:l-glutamate gamma-ligase (adp forming), ec 6.3.2.17] has been cloned by functional complementation of an escherichia coli folc mutant. the cdna encodes a 545-residue protein of m(r) 60,128. the deduced sequence has regions that are highly homologous to peptide sequences obtained from purified pig liver fpgs and shows limited homology to the e. coli and lactobacillus casei fpgss. expression of the cdna in e. coli result ... | 1992 | 1409616 |