Purification and certain properties of a bacteriocin from Streptococcus mutans

An inhibition factor from Streptococcus mutans strain C3603 (serotype c) was purified and isolated, and its properties indicated that it was a bacteriocin. Bacteriocin C3603 is a basic protein with a pI value of 10 and a molecular weight of 4,800. The activity of this bacteriocin was not affected by pH over a range of 1.0 to 12.0 or by storage at 100 degrees C for 10 min at pH 2.0 to 7.0 or storage at 121 degrees C for 15 min at pH 4.0. Pronase; papain, phospholipase C, trypsin, and alpha-amylase had no effect on the activity of the bacteriocin, whereas alpha-chymotrypsin and pancreatin were partially active against it. Bacteriocin activity was greater against certain S. mutans strains of serotypes b, c, e, and f than against certain S. mutans strains of serotypes a, d, and g. Bacteriocin C3603 was also effective against selected strains of S. sanguis, S. salivarius, S. bovis, S. faecium, S. lactis, Lactobacillus casei, L. plantarum, L. fermentum, Bifidobacterium bifidum, Bifidobacterium longum, Propionibacterium acnes, and Bacteroides melaninogenicus, but it was not effective against certain strains of Escherichia coli, Klebsiella pneumoniae, Corynebacterium parvum, and Candida albicans. The inhibition of S. mutans strains BHT and PS-14 by bacteriocin C3603 was found to be due to the bacteriocidal activity of the bacteriocin. When water or a diet containing bacteriocin C3603 was consumed by gnotobiotic and specific pathogen-free rats infected with S. mutans PS-14, the caries score was found to be significantly reduced.

Plasma and skeletal muscle amino acids following severe burn injury in patients and experimental animals

This study describes and analyzes sequential changes in plasma and skeletal muscle free amino acids following severe burn injury. Plasma free amino acids were determined in children (n = 9) with burns averaging 60% total body surface area and were compared with laboratory beagles (n = 44) which received a flame burn totaling 30% of their body surface area. In addition, needle biopsy specimens were obtained from the semitendonosus muscle in the animals to determine free intracellular amino acids. In both patients and animals the amount of total free amino acids in plasma fell following burn, suggesting relative protein deficiency. This drop was primarily due to a 47% drop in nonessential amino acids. However, plasma phenylalanine was consistently higher than normal following burn, and was strongly associated with death and weight loss in both animals and patients, especially when analyzed as a ratio with tyrosine. This finding suggested excessive catabolism, hepatic dysfunction, or both. Plasma levels of several amino acids correlated significantly with weight loss. Alterations in muscle free amino acids generally were similar to plasma amino acids. Exceptions were muscle alanine and glycine which strongly correlated with weight loss. However, the determination of muscle free amino acid profiles did not yield clinically useful information not available from plasma profiles. Plasma levels of liver enzymes suggested progressive hepatic dysfunction. These studies show that the laboratory beagle is a good model for studying the metabolic alterations of amino acids that accompany burn injury, since they mimic humans in many parameters which appear to be most useful with respect to clinical evaluation.

The increase of the electrophoretic mobility of platelets after laparotomy

A fully automatic instrument for the determination of electrophoretic mobility of colloidal particles was applied to human platelets. A significant increase in platelet electrophoretic mobility was observed one day after a laparotomy. This suggests that a selective consumption of platelets with smaller surface negative charge may occur during postoperative hemostatic plug formation or under surgical stress. In addition, the difference in electrophoretic mobility observed between males and females suggests an effect of estrogen on platelets.

Decrease in Platelet Adenine Nucleotides Content In Patients With Dic, Thrombosis and After Operation

Conditions which induce platelet release reaction in vivo are not yet obvious. To detect the conditions, platelet ATP and ADP content (firefly luciferase method) and plasma beta-thromboglobulin level were measured in 51 healthy young volunteers, 10 patients with typical DIC syndrome during time course of cancer, 27 patients in acute stage of thrombosis in cerebral, coronary and femoral arteries, 29 patients in recovery stage of thrombosis and 69 patients one day before, and one day, one week and one month after a laparotomy. Platelet count and volume were counted by a Coulter Counter and Channelyzer. Platelet aggregation induced by ADP, adrenaline and collagen was also measured. In the healthy, platelet mode volume was 4.21 ± 0.08 μ3 (mean ± SE). beta-TG was 29.9 ± 5.9 ng/ml, and ATP and ADP contents were 5.81 ± 0.17 and 3.19 ± 0.09 μmoles/1011 platelets and ATP/ADP was 1.82 ± 0.05. In DIC, acute stage of thrombosis and one week after laparotomy, platelet volume became to smaller and ADP content decreased significantly. Changes in beta-TG level were rather variable. Platelet aggregation increased in thrombosis and postoperative state, while it decreased in DIC. In DIC, decrease in ATP and ADP content was marked as compared with other groups. It suggests that ADP content In platelets may reflect release reaction in vivo. Following the release reaction, platelet aggregability may increase. However, platelets with large decrease in adenine nucleotides content may have hypofunction.