Theophylline in oral mucosal transudate. A practical method for monitoring outpatient therapy.

We tested the utility of a novel collection system that allows measurement of theophylline in oral mucosal transudate (OMT) to calculate serum theophylline concentrations. In 25 adult patients, theophylline levels in OMT correlated better than expectorated saliva with serum theophylline (r = 0.927 for OMT versus r = 0.831 for expectorated saliva, each p < 0.0001). In a subsequent study of 128 patients (118 adults and 10 children aged 4 to 12 yr), OMT and serum theophylline were measured and polynomial regression analysis performed to allow calculation of serum level for any given OMT level. Theophylline levels calculated from OMT values closely followed measured serum theophylline in two normal subjects after administration of either intravenous or oral theophylline. OMT samples collected by 24 patients at home were mailed to the laboratory for testing. Theophylline values from the home collection samples correlated closely (r = 0.930, p < 0.0001) with serum theophylline levels obtained at the same dose of theophylline. These findings suggest that once the relationship of serum to OMT theophylline is established in a given laboratory, the latter can be used to monitor outpatient theophylline therapy in adults (and possibly children) at times of the day otherwise inaccessible to serum sampling.

Prolonged reduction of hepatocyte proliferative ability in rats after a single treatment with carbon tetrachloride.

Female Wistar rats were pretreated with I ml of carbon tetrachloride/kg of body weight or with olive oil. All the rats were given this dose of CCl4 20 or 40 days later. Liver regeneration as evaluated by 3H-thymidine incorporation into liver DNA and by the number of mitotic hepatocytes was markedly impaired in CCl4-pretreated rats when compared with olive oil-pretreated controls. DNA labelling reached only 83 and 59% and mitotic index 35 and 58% of control values, respectively, at 20-day and 40-day time intervals. The variables characteristic of liver damage did not parallel the changes in cell division. About 20% of hepatocytes were necrotic both in the CCl4-pretreated and in the control rats. The activity of serum alanine aminotransferase was higher in the CCl4-pretreated rats. Only serum aspartate aminotransferase activities were somewhat lower when compared to controls. Similarly, serum aminotransferases were much less affected by the pretreatment than the markers of regeneration when two low doses of CCl4 (0.125 ml/kg) were given to rats 20 days apart. The activities of microsomal enzymes aniline hydroxylase and pethidine demethylase were equal in control and in experimental rats 20 days after CCl4 pretreatment which indicated that the effects of CCl4 were not mediated by an overall decrease in cytochrome P-450 enzymes. In summary, a single pretreatment of rats with CCl4 induced changes in liver that lasted for 40 days and impaired liver regeneration when another dose of CCl4 was applied.

Scleroplasty in progressive myopia--selection of materials.

Scleroplastic surgery is known to encounter the pathogenetical agent when the progressive myopia develops. In the first part, the implemented surgical approaches as well as up-to-date surgical techniques are presented. The experimental part is reserved for the selection of material which is necessary to perform scleroplasties. Both the allogenic and xenogenic grafts have been studied for histocompatibility on 20 rabbits. Following materials were used: 2 types of collagenic sponge, native and deproteinated human sclera, modified dura mater as well as both the native and devitalized sclera from rabbits. The best results were obtained with allogenic sclera, deproteinated xenogenic sclera and collagenic sponge. The application of other materials is discussed.

Relationship of liver damage and liver regeneration after carbon tetrachloride treatment in rats.

Various doses of carbon tetrachloride (0.625 mmol to 10 mmol CCl4/kg body weight) were administered to female Wistar rats. Liver damage after a single treatment was evaluated by serum aminotransferase levels and by the extent of necrotic areas in parenchyma. Liver regeneration was evaluated by 3H-thymidine incorporation into liver DNA and by the number of dividing hepatocytes. Mitotic index of hepatocytes rose in parallel with the specific activity of DNA and with the extent of necrosis. However, the activities of serum aminotransferase AST and ALT increased much more rapidly and did not correlate either with necrosis or with regeneration rate. Increased membrane permeability in morphologically intact cells, increased synthesis of the enzymes by the liver as well as the leakage from necrotic cells are discussed as possible causes of the high aminotransferase activities in serum.

No embryotoxicity of exogenous alpha-elastin evidenced through interference with the chick embryonic morphogenetic systems.

The effects of alpha-elastin (1) on the morphogenetic systems of the chick embryo were studied by means of the CHEST (chick embryotoxicity screening test). The subgerminal administration of doses of 0.3 mg and larger induced a growth retardation of the caudal morphogenetic systems (CMS). The administration of single effective doses of 1 subgerminally on the second day and intraamniotically on the third and fourth d of embryogenesis verified the beginning of the direct embryotoxicity range between the doses of 0.3 and 1 mg per embryo. It presents in the theoretical extrapolation for mammals the dose limits between 1 and 10 g.kg-1 of maternal weight. Embryotoxic manifestations (body wall defects, growth retardation and embryolethality) were induced predominantly in the embryos treated on d 2 with the very high doses only. Their frequency was rare. It has been concluded that 1 could be a safe potential natural drug carrier in clinical practice.

Formation of granulomas in liver of silica-treated rats.

Hepatic silicosis was induced in rats by an intravenous injection of saline-suspended silica, 40 mg/kg of body weight. Changes in the liver were examined by biochemical, histological and histochemical methods. Infiltration of the liver parenchyma by polymorphonuclear leucocytes was observed only on the first day after silica treatment. Formation of silicotic nodules began on the first day by clustering of liver macrophages. A 22% increase in liver weight and a 67% increase in total liver DNA reflected accumulation of cells in the liver by day 28 after silica injection. Local cell division contributed to this increase. Almost all cells in the nodules contained carbon when the rats had been given ink before silica. Macrophages showed high activity of lysosomal esterases on the first few days after silica treatment; the activity disappeared later. Large granulomas containing hundreds of cells including lymphocytes were seen 226 days after treatment. Hydroxyproline content per gram of liver tissue increased by 35% and 58% by day 80 and 162, respectively. Connective tissue formed capsules around the nodules and grew to their inside. Activities of lysosomal enzymes, beta-D-galactosidase and acid proteases, in serum were increased by 20% and 300%, respectively, 35 days after treatment. Neither malondialdehyde concentration nor superoxide dismutase activity was elevated in silicotic liver.

Effect of carbanilate local anesthetics on granulation tissue formation.

The effect of local anesthetics pentacaine ((+/-)-trans N-/2-(3-pentyloxy-phenylcarbamoyloxy)-cyclohexyl/- pyrrolidinium chloride), heptacaine (N-/2-(2-heptyloxy-phenyl-carbamoyloxy)-ethyl/-piperidini um chloride) and trimecaine (2, 4, 6-trimethylphenylcarbamoyl)-methyldiethylammonium chloride) on granulation tissue formation in open skin wounds was examined in rats. The anesthetics applied on the wounds 3 times a day for 5 days caused increase in granulation tissue weight, in DNA and hydroxyproline contents. Pentacaine had the most pronounced effects (190% dry weight, 253% DNA and 148% hydroxyproline content when compared to saline-treated controls). The smallest changes were observed after heptacaine treatment.

[Quantitative structure-activity analysis of thiobenzamides]. / Quantitative Struktur-Wirkungs-Analyse der Thiobenzamide.

It is very difficult to meet all prerequisites for the optimization of the tuberculostatic action of thiobenzamides. On the one hand, a strongly polarized C=S bond of the thiocarbamido group is necessary, and on the other hand, the value of the Hammett constant must be positive (to prevent hepatotoxicity). The conjugated system can be extended to reduce the excitation energy of the eta-eta electronic transition. However, the lipophilicity should not be overincreased (to avoid the risk of increased antimitotic activity and acute toxicity). Of the culture media, the Sauton system seems to be best suited since it is the most simple. However, the culture medium according to Sula comes closest to in vivo conditions as it contains proteins and is devoid of surfactants.

Identification of spermine as an inhibitor of erythropoiesis in patients with chronic renal failure.

Fetal mouse liver and normal human bone marrow cell cultures were used for studies on the inhibition of erythroid colony formation (CFU-E) by sera from anemic patients with end-stage renal failure and the polyamine spermine. Sera from each of eight predialysis uremic anemic patients with end-stage renal failure produced a significant (P < 0.001) inhibition of erythroid colony formation in the fetal mouse liver cell cultures when compared to sera from normal human volunteers. In vivo or in vitro dialysis of the uremic sera with a 3,500-dalton exclusion limit membrane removed the inhibitor from uremic sera. The uremic serum dialysate provided by the membrane fractionation was significantly inhibitory in the erythroid cell cultures. When this dialysate was applied to gel filtration chromatography (Bio-Gel P-2) the inhibitor was found to be in the same molecular weight range as [(14)C]spermine. The polyamine spermine produced a dose-related inhibition of erythroid colony formation (CFU-E) in fetal mouse liver and normal human bone marrow cultures. Thus, the following evidence is provided that the in vitro inhibitor of erythropoiesis found in chronic renal failure patients' sera is identical with the polyamine spermine: (a) the inhibitor and radiolabeled spermine appeared in identical Bio-Gel P-2 effluent fractions; (b) when spermine was added to normal human sera at concentrations reported in sera of uremic patients, and studied in both the fetal mouse liver cell culture and normal human bone marrow cultures, a dose-related inhibition of erythroid colony (CFU-E) formation was noted; and (c) the inhibitory effects of crude uremic serum, uremic serum dialysate, and fractions of uremic serum dialysate from a Bio-Gel column, on erythroid colony formation were completely abolished by the addition of a specific rabbit antiserum to spermine.

Effect of endotoxin on granulation tissue formation in rats.

Open wounds were incised in the dorsal skin of female Wistar rats. Solutions of Salmonella typhosa endotoxin (0.25 micrograms to 25 micrograms/ml saline) were applied 3 times a day on granulation tissue formed in the wounds. 5 days of treatment with the lowest endotoxin concentration resulted in 25% increase of the weight of the tissue, a more than 30% increase of DNA content and a 25% increase of hydroxyproline content in the tissue. Further elevation of these values could be obtained by increasing endotoxin concentration by tenfold or hundredfold but these changes were not very pronounced.

Development of a specific antispermine antibody.

Highly specific antibody to spermine was produced in the rabbits by immunization with a spermine-thyroglobulin conjugate of high molar ratio (740:1). Cross-reactivity with spermidine was 1.4-2.2 percent and negligible with putrescine and other compounds of similar structure. The average affinity constant of five pools of antispermine rabbit antisera was Ka = 1.8 +/- 0.2 X 10(8) liter/mole.

Antibody to spermine: a natural biological constituent.

A protein that binds spermine specifically was separated from normal rabbit serum by affinity chromatography. Immunoelectrophoresis, the Ouchterlony immunodiffusion test, and gradient gel electrophoresis indicated that this protein has immunoglobulin characteristics and consists of several populations of antibodies to spermine. These were sequentially released from Sepharose-spermine gel by step-wise elution with solutions ranging in pH from 4 to 1. The binding constants varied from 5.0 x 10(8) to 11.1 x 10(8) liters per mole. These globulins did not react with monoacetylputrescine, L-ornithine, L-lysine, and histamine. Negligible cross-reactivity was detected with spermidine, putrescine, N8-monoacetylspermidine, cadaverine, and diaminopropane. Since perturbations in polyamine metabolism have been identified in several diseases, the study of extracellular polyamine homeostasis may reveal an important regulatory function for this protein.