A modification of lactoferrin isolation method]

A modified method was developed to isolate lactoferrin from women's colostrum by means of ion-exchange chromatography on a Servacel CM-52 column and gel filtration on a Toyoperal HW-52 column. These changes simplified the basic method and decreased the length of the procedure without affecting the biological activity and purity of the preparation. The modified method can be recommended to produce lactoferrin suitable for the use as a pharmaceutical preparation and nutritional additive to milk substitutes.     

Pharmacokinetics of semisynthetic cephalosporins for parenteral use on surgical patients]

Pharmacokinetics of 4 cephalosporanic antibiotics for parenteral use, i. e. cephaloridine, cephradine, cephazoline and cephacetryl was studied in surgical patients with normal function of the kidneys and liver. The first 3 drugs were well absorbed after intramuscular administration, their maximum serum levels being achieved during the first hour. High blood levels of cephacetryl were determined after its intravenous administration. When cephaloridine, cephradine and cephazoline were administered in equal doses, it was found that the first 2 drugs did not practically differ with respect to the values of the serum levels, the rate of elimination from the blood, the rate and level of excretion with the urine. Cephazoline was characterized by higher blood levels and slower elimination from the blood.     

Comparative study of cephalexin and cephradine distribution in the body of rats]

Distribution regularities of cephalexin and cephradine, 2 semisynthetic cephalospor in antibiotics for oral use were studied on rats. It was found that the cephalosporins had a capacity for satisfactory penetration through the histochematological barriers. The drugs were rather rapidly absorbed from the gastrointestinal tract of the rats into the blood. Their maximum blood levels were determined 1 hour after the administration. The highest cephalosporin concentrations were detected in the kidneys and liver. Still, the level of cephradine in the kidneys was lower and that in the liver was higher than the levels of cephalexin. The lowest concentrations were found in the skeletal muscles. The character of cephradine distribution in the lungs, heart and spleen differed from that of cephalexin; the maximum concentrations of cephradine in these organs were achieved 1 hour after its administration, while those of cephalexin were achieved in 30 minutes. The antibiotics were not detected in the brain tissue. No increase in the concentration gradient with time was observed.     

Partial antigenic structure of group H10 flagellins in Escherichia coli and its genetic determination

The study of flagellar antigens classified with serotype H10 has been made in E. coli belonging to different OK-groups. These antigens have been shown to differ in their partial structure. Group H10 antigens have been found to comprise 7 variants, and their partial structure has been determined. The study has shown that antigenic variants of the same type occur in E. coli belonging to different OK-groups and different variants may occur in strains within the same OK-group. The data obtained in the study of the expression of genes, responsible for the synthesis of flagellin, in the system of isogenic strains suggest that differences in the partial structure between the variants of group H10 antigens are linked with differences between the corresponding alleles of the flagellin-specifying gene. The differentiation of these antigens by means of factor-specific antibodies may prove to be of practical importance for solving the problems of the epidemiology and etiology of diseases caused by E. coli having group H10 flagellar antigens.     

Comparative study of the interaction of cephalosporins with blood serum proteins and organ homogenates

Interaction of 7 semisynthetic antibiotics (cephaloridine, cephalexin, cephradine, cephazolin, cephalotin, cephacetrile and cephapirin) with proteins of human, bovine and rabbit blood serum, as well as organ and tissue homogenates of rats was studied comparatively. The study showed that binding of the cephalosporins by the blood serum depended on both the chemical structure of the antibiotic and the species affiliation of the protein substrate. The binding lvels of cephazolin and cephalotin by the blood serum proteins (except bovine serum) were the highest, while the binding level of cephaloridine was the lowest. A significant decrease in the values of binding by the serum proteins of the drugs with high percentage of binding was observed when the drug concentrations in solution were increased. Binding of the cephalosporins by the blood serum proteins was in most cases completely reversible. The activity of the cephalosporins decreased in the presence of the rat organ and tissue homogenates. The levels of the activity decrease as compared to the theoretical ones were the highest with the use of cephalotin, cephacetrile and cephapirin. The lowest values of detection of these antibiotics were noted on their incubation with the liver, kidneys and lungs.     

Biological and physicochemical properties of the alpha- and beta-forms of cephaloridine]

Alfa- and delta forms of cephalosporin were compared. Biological activity, lantimicrobial spectrum and innocuousness of the forms and their physico-chemical properties were investigated with the methods of infrared and ultraviolet spectrophotometry and derivatography. No significant differences in the biological properties of alfa- and delta forms of cephalosporin were found. However, the ingrared spectrum of the delta-form was indicative of higher stability of its molecule, which was confirmed by higher thermostability of delta-cephalosporin.     

The fractionation of non-histone chromosomal proteins from rat kidney and liver and their DNA complexes by using the cation exchangers phosphocellulose and SE-Sephadex]

Results of the gradient chromatography of chromosomal nonhistone proteins of the rat liver and kidney and their complexes with DNA on the phosphocellulose and SE-Sephadex are presented. The profiles of elution of the preparation of the homologous tissues with NaCl linear gradient of 0.1-1.0 M are equal. In the fractions of 0.4-0.5 M NaCl, protein components are discovered only in the samples of kidney.     

Dispersal of four fritillary butterflies within identical landscape

Both species-specific traits and landscape configuration, such as area and connectivity of habitat patches plus the character of uninhabitable matrix, affect animal movements in fragmented landscapes. Difficulties with disentangling species-specific and landscape effects have obscured comparisons among species, hindering the understanding of dispersal in metapopulations. To circumvent this complication, we performed a mark–recapture study of four related nymphalid butterflies within identical landscape and in single season. The studied species were three Melitaeinae checkerspots (Euphydryas aurinia, Melitaea athalia, Melitaea diamina) and one Argynnini fritillary (Brenthis ino). Applying the Virtual Migration model revealed that (1) except for mortality within habitat, model parameters differed from those found for the studied species elsewhere; (2) the three Melitaeinae species were more akin in movement parameters than the Argynnini representative (i.e., B. ino); (3) within Melitaeinae, differences between sexes were more prominent than differences among species; (4) Melitaeinae males left natal patches more readily than females, while the opposite applied to B. ino; (5) males of M. diamina and both sexes of B. ino exhibited highest values of dispersal mortality; (6) except for females of M. diamina and both sexes of B. ino, immigration and emigration scaled with area in females but not in males. Finding (1) demonstrates that geometry of habitat network affects mobility considerably and that transferring dispersal parameters across systems is unwarranted. Still, (2–6) demonstrate that within identical networks, related species follow similar dispersal patterns, suggesting that conservation scenarios suitable for a well-studied model species would suite related species as well.