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Biomedical subjects

I Lambert

Publications and source records attributed to I Lambert.

At least 37 records · Page 2Linked to original sources
PubMed1983

The comparative biologic and toxic potencies of polychlorinated biphenyls and polybrominated biphenyls.

Aroclor 1254 and fireMaster BP-6, two commercial polychlorinated biphenyl (PCB) and polybrominated biphenyl (PBB) preparations, exhibit comparable biologic and toxic effects. In the present study the commercial PBB was more active than Aroclor 1254 in causing thymic atrophy in male Wistar rats. However, a direct comparison of the relative effects of bromine vs chlorine substituents is not possible with the commercial PBB and PCB mixtures due to their complex congeneric composition. This study reports the synthesis and biologic and toxic effects of a series of laterally substituted 3,3',4,4'-tetrahalobiphenyls which contain the following variable molecular Cl/Br ratios; Br4, Br3Cl, Br2Cl2 (two isomers), BrCl3, and Cl4. 3,3',4,4'-Tetrabromobiphenyl and 3,4,4'-tribromo-3'-chlorobiphenyl (150 mumol/kg)-pretreated animals significantly inhibited the growth rate of and caused thymic atrophy in immature male Wistar rats whereas those isostereomers with reduced Br (and increased Cl) content were either less active or inactive. Pretreatment of male Wistar rats with 10 mumol/kg of the 3,3',4,4'-tetrahalobiphenyls and determination of their effects as inducers of the hepatic microsomal drug-metabolizing enzymes also illustrated the effects of the relative Cl/Br ratios on induction potencies. Both 3,3',4,4'-tetrabromo- and 3,4,4'-tribromo-3'-chlorobiphenyl maximally induced the cytochrome P-448-dependent monooxygenases, benzo[a]pyrene and 4-chlorobiphenyl hydroxylase; the order of potency of the other isostereomers was 4,4'-dibromo-3,3'-dichloro- congruent to 3,4-dibromo-3',4'-dichlorobiphenyl greater than 4-bromo-3,3',4'-trichloro- greater than 3,3',4,4'-tetrachlorobiphenyl. With few exceptions this order of potency was observed for the induction of benzo[a]pyrene hydroxylase and ethoxyresorufin O-deethylase in rat hepatoma cells in culture and for their relative binding affinities to the rat cytosolic receptor protein. The data clearly demonstrate that the biologic activities of this group of isosteric halogenated biphenyls are enhanced with increasing bromine substitution and also support the hypothesis that the activities of this class of chemicals are mediated through the receptor.

Animals↗
PubMed1983

Effects of hypo and hyperosmotic media on rabbit renal cortical slices.

Rabbit kidney cortex slices behave as osmometers when withstanding either hyperosmotic shocks or hypo-osmotic shocks of amplitude up to P1/P2 = 1.25. For hypo-osmotic shocks of amplitude larger or equal to P1/P2 = 1.5 a volume regulation process occurs. Na+ is the main osmotic effector implicated in volume control.

Animals↗
PubMed1983

Effect of osmotic shocks on rabbit kidney cortex slices.

Rabbit kidney cortex slices behave an osmometers when withstanding hyperosmotic or hyposmotic shocks of amplitude up to pi 1/pi 2 = 1.25. For hyposmotic shocks of amplitude larger than or equal to pi 1/pi 2 = 1.50, the maximum swelling achieved is less than what can be expected on the basis of the van't Hoff relation, thereby indicating that a volume regulation process is taking place. Volume regulation in kidney slices can be dissociated into two distinct phases. The first one, of swelling limitation, is very rapid and keeps maximum cell volume at values lower than expected when the tissue is considered as an osmometer. This phase is followed by a slow volume readjustment process during which volume progressively decreases towards control values. The major intracellular osmotic effector loss during both swelling limitation and volume readjustment is Na+. The overall volume regulation process is insensitive to furosemide, vanadate, and bumetanide. Swelling limitation is blocked by addition of ouabain. Contrary to what has been believed previously, there is, however, no need to implicate control of the activity of a ouabain-sensitive, Na+/K+ pump in the Na-dependent volume regulation mechanism.

Amino Acids↗
PubMed1979

[Immunochemical properties and therapeutic usefulness of the preparation Igalina produced by Biomed].

In order to obtain higher concentration of IgA-antibodies in commercial gammaglobulin preparations, used for treatment of hipo - and dysimmunoglobulinemia states, there are produced two preparations: "Gamma-A- Konzentrat " of Behringwerke and " Igalina " of Biomed . The first one was examined and described by us previously (4, 12). Now we present our studies on Igalina . The examinations were performed using electrophoresis on cellulose acetate, double diffusion in agar gell using 15 specific antisera to plasma proteins and immunoelectrophoresis with anti-IgG, IgA and IgM. There were detected traces of albumin, transferin , alfa2 macroglobulin, haptoglobin fibrinogen and presence of IgA, IgG and IgM. We also observed the split of IgG line in immunoelectrophoresis at the cathode and to Fc and Fab fragments. The concentrations of IgA, IgG and IgM were evaluated using Mancini method (IgA--920 IU/ml, IgG--1640 IU/ml IgM 2500 IU/ml). Concentrations of chosen antibodies in Igalina were: ASO--1000 U/ml, anti- Staphylolisins 8 U/ml, agglutinins antistaphilococal 1 : 320, diphtheria antitoxins 42 U/ml, agglutinins antithyphi 1 : 20----1 : 640. They were 4 to 100 times higher than in plasma serum. Isohaemagglutinins were not detected. Igalina was used for preventive treatment of children contacted with viral infections or therapeutically for children who demonstrated first symptoms of viral infections of respiratory tracts. Preparation was given 48 times to 40 children. This group included 19 newborns and 10 children with I and IV type of dysimmunoglobulinemia or hipoimmunoglobulinemia . Doses ranged from 0,5 ml up to 1,0 ml/kg body weight. Estimations of IgA, IgG and IgM concentrations in serum and saliva of children (using Mancini method) were carried out before injection of Igalina and on the third and seventh day after injection. Results of studies were statistically evaluated, and besides the lack of significant differences we found some rise of IgA and IgG concentrations. We would like to underline also that in 6 children with hipo or dysimmunoglobulinemia the levels of IgA and IgG reached normal value on the third day after injection of Igalina . Investigations of secretory piece in saliva in the same period were carried out too. In three patients we could find the presence of secretory piece just after injection of Igalina . We did not found antibodies to IgA in patients' sera after treatment. The clinical results of treatment as well as toleration of the drug were good and very good.

Adjuvants, Immunologic↗
PubMed1975

[Investigation on protein and protein fractions concentration in the serum of healthy children over one year old (author's transl)].

Protein concentration and the relative percentage of protein fractions in serum have been studied in 2 to 15 years old 226 healthy children. The mean values and standard deviation were calculated for every year of child life. The correlation analysis of all parameters investigated with the age of the children was also presented, as well as the relationships between the various parameters.

Adolescent↗
PubMed1975

[Study of the antigenic properties of the duodenum juice in children with cystic fibrosis (author's transl)].

Comparative study of the antigenic properties of the duodenal juice has been carried out; the samples of duodenal juice were collected from the following three groups of children: 1) healthy children 2) children with lambliosis 3) children with cystic fibrosis. The method of double diffusion and precipitation in agar according to Ouchterlony and immunoelectrophoresis technique according to Scheidegger were used. The author's own specific rabbit antisera were applied. On the basis of the results achieved the conclusion may be drawn that the duodenum content of children suffering from cystic fibrosis includes, apart from antigens immunologically identical with the duodenal content of healthy children, also a separate antigen with specific traits for cystic fibrosis. It was also found that a pathological mucoprotein, appearing sporadically in the duodenum juice of children with lambliosis is in no connection with the antigen specific for cystic fibrosis.

Age Factors↗
PubMed1975

[A direct micromethod for transferrin level determination in human serum (author's transl)].

All the methods of quantitative estimation of transferrin concentration applied until recently have consisted in calculating the amount of this protein through the amount of iron bound in the blood serum. For this purpose the total iron binding capacity of serum (TIBC) has to be determined and then transferrin concentration is calculated. The calculation is based on the fact found by Ehrenberg and Laurell (1955) that two atoms of trivalent iron are selectively bound with one molecule of transferrin. The disadvantage of this method consists mainly in the necessity to carry out the measurement twice in every serum sample and in the large amount of material necessary for the analyses: this is a great inconvenience for pediatric clinics. The single-radial diffusion method in agar-gel was evaluated to be very advantageous for quantitative estimation of transferrin because of its simple technique and reaction specifity. The quantitative estimation is possible by the pilot calibration curve that represents the relationship of the diameter of a given circle and transferrin concentration. The quantity of material necessary for analysis amounts to not more than 5 mul of serum. Specific antitransferrin serum has to be imported and this seems to be the only reason why the said technique has not been used in Poland so far. The sera and vaccine laboratories in Warsaw have recently started to produce this antiserum and pure human transferrin. This has stimulated us to work out the single-radial diffusion method in agar based on Polish antiserum and Polish standard. The quality of the Polish specific rabbit antitransferrin serum and Polish pure human transferrin was tested by the immunoelectrophoretic method. The above findings provide the evidence that the Polish reagents are as good as those of the Behringwerke. Single-radial diffusion in agar gel should be carried out under the following conditions. 1) reaction temperature: 20-22degreesC 2) reaction time 24 hours 3) optimum concentration of antitransferrin serum in agar is 1:5.2. The error of the immunochemical method was determined experimentally and was found to be 9.05%. The results obtained with Polish and Behringwerke reagents were compared and were very similar.

Animals↗