Influence of thymosin and the supernatant of cultured mouse thymus reticuloepithelial cell on mouse immune responses

Effects of the humoral factor extracted from the calf thymus (thymosin: Goldstein et al.) and the supernatant of cultured mouse thymus reticuloepithelial cell (TRC) on immunological functions of the mouse lymphocytes were studied, and the following conclusions were drawn: Thymosin treatment did not alter the capacity to form anti-SRBC antibody in adult mice which were lethally irradiated and reconsituted with bone marrow cells. When the spleen cells from JCL-ICR mice thymectomized within 24 hr after birth were cultured with thymosin or supernatant of cultured ICR-TRC, the Thy 1 positive cells were increased. A significant increase in the mitogenic (PHA, Con A) reactivity of BALB/C spleen cells was observed when these cells were preincubated in medium containing thymosin for 24 hr. The NZB spleen cells, however, exhibited spleen cells showed a slightly potentiated response only to Con A. Similarly, thymosin enhanced the MLC reaction of the spleen cells from BALB/C mice with preincubation for 2 hr, but not enhanced that from NZB mice.

A novel method for evaluating the outer membrane permeability to beta-lactamase-stable beta-lactam antibiotics

A novel method is described which allows estimation of the outer membrane permeability to beta-lactamase-stable beta-lactams by determining antibiotic concentrations in the periplasm. The method is based on measurement of the inhibiting activity of beta-lactamase-stable beta-lactams on the hydrolysis of a substrate by periplasmic beta-lactamase. Application of the method to carbenicillin revealed that the high level of resistance to carbenicillin of an Escherichia coli strain acquiring the plasmid encoding ampicillin resistance resulted from the poor ability of carbenicillin to penetrate the outer membrane of E. coli.

Effects of organic and inorganic mercurials on thyroidal functions

Acute effects of methylmercuric chloride and mercuric chloride on thyroidal functions were examined. The organic mercurial concentration of 4 x 10(-5) M inhibited by 50% of Na+K+ATPase in the membraneous preparation from the hog thyroid, and 6 x 10(-7) M of the inorganic mercurial showed the same extent of the inhibition. The Mg2+ ATPase activity in the preparation was neither affected by CH3HgCl up to a concentration of 2 x 10(-3) M, nor by HgCl2 up to 1 x 10(-4) M. After an intraperitoneal injection to mice of 5 micrograms of mercurial per gram body weight daily for 2 consecutive days, the 4-hour and the 24-hour uptakes of 131I by the thyroids were partially reduced by both organic and inorganic mercurials. A significant reduction in percentages of labeled iodothyronines was demonstrated to suggest that mercurial may cause a coupling defect in the synthesis of iodothyronines. Incubation of hog thyroglobulin with 8 x 10(-3) M of methylmercuric chloride caused no observable aberration in slab disc electrophoreogram, but the protein was apparently denatured by the same concentration of mercuric chloride suggesting that thyroglobulin may carry a large binding capacity against either mercurial, but the inorganic mercurial can be more potent denaturant of the protein. The in vitro lysosomal hydrolysis of the mercurial-pretreated rat thyroglobulin which was labeled with 125I in vivo and fortified with the carrier hog thyroglobulin was not affected, but the direct addition of either mercurial in the medium resulted in a significant inhibition of the proteolytic action. Iodotyrosine deiodinase in the thyroid was inhibited by both mercurials in in vitro and in vivo systems. A partial reduction in the serum bound 131I-iodide in both mercurial treated groups was observed at 4 hours and 24 hours after the radioiodide administration. The blood thyroxine levels estimated by radioimmunoassay were quite reduced in the inorganic mercurial treated group and also moderately reduced in the methylmercurial treated group, indicating that the hormone secretion was affected by mercurials.

Enterobacter cloacae outer membrane permeability to ceftizoxime (FK 749) and five other new cephalosporin derivatives

The ability of ceftizoxime to penetrate the outer membrane was compared with those of five other new cephalosporins: cefotiam, cefuroxime, cefotaxime, cefmetazole and cefoxitin, using a clinical isolate of Enterobacter cloacae as a test strain. Estimation of permeability was performed by a method utilizing the inhibitory activities of the cephalosporins against beta-lactamase located in the periplasm. Of the cephalosporins tested, both ceftizoxime and cefmetazole gave remarkably high concentrations in the periplasm, several times higher than those of cefotaxime and cefoxitin and ten or more times higher than those of cefuroxime and cefotiam. The approximate permeability coefficient of ceftizoxime was also several times higher than those of cefotiam and cefmetazole and over ten times higher than those of cefoxitin, cefuroxime and cefotaxime.

Pharmacokinetics of ceftizoxime in animals after parenteral dosing

The pharmacokinetic profile of ceftizoxime was studied in mice, rats, dogs, and monkeys given the drug in a single parenteral dose. The serum data after an intravenous injection were analyzed by the two-compartment open model. Cefotiam, cefmetazole, cefotaxime, and cefamandole were used as reference drugs. High concentrations of ceftizoxime were attained in the sera of all test animals and in the tissues of rats after parenteral dosing. The serum concentrations of ceftizoxime were higher than those of the other antibiotics in large animals (dogs and monkeys), but were lower in small animals (mice and rats). About 80% of ceftizoxime was excreted unchanged in the 24-h urine of all species tested. The biliary excretion of ceftizoxime was low: 3.7% in rats and 0.59% in dogs. However, therapeutically significant concentrations of ceftizoxime were found in the bile of dogs. Ceftizoxime was stable in biological fluids such as serum, urine, and tissue homogenates, but cefotaxime was unstable in rat tissue homogenates. Binding of ceftizoxime to serum protein in all species was the lowest of all the antibiotics: 31% for humans, 17% for dogs, and 32% for rats.

In vitro and in vivo antibacterial activities of FR-31564, a new phosphonic acid antibiotic

FR-31564, a new phosphonic acid antibiotic, was active against most Gram-negative bacteria except Serratia marcescens and glucose-nonfermenting Gram-negative rods excluding Pseudomonas aeruginosa. The antibacterial activity in vitro of FR-31564 was stronger than that of fosfomycin especially against Escherichia coli, Klebsiella pneumoniae, Enterobacter species and P. aeruginosa. FR-31564 also was active against Gram-negative bacteria resistant to beta-lactam antibiotics and against gentamicin-resistant strains of P. aeruginosa. The antibacterial activity in vitro of FR-31564, like that of fosfomycin, was enhanced when 10% rabbit blood was added to the nutrient agar. The therapeutic efficacy of FR-31564 in experimental infections in mice was superior to that of fosfomycin in infections due to most Gram-negative bacteria used, and was similar to that of gentamicin in infections due to Citrobacter freundii, Proteus rettgeri and Proteus inconstans B. The protective effect of FR-31564, particularly in the P. aeruginosa infection, was superior to that of other control drugs including gentamicin.

FR-31564, a new phosphonic acid antibiotic: bacterial resistance and membrane permeability

Mutants which acquired resistance to FR-31564 were also resistant to fosfomycin and vice versa. Some exceptions to cross-resistance were found among clinical isolates of certain species. FR-31564 was found to be incorporated into bacterial cells more efficiently than fosfomycin although the extent of incorporation varied among species. In particular, the uptake rate of FR-31564 by a strain of Pseudomonas aeruginosa was ten times that of fosfomycin. The uptake rate of FR-31564 by both FR-31564- and fosfomycin-resistant mutants was less than one-tenth of that by the parent strain. FR-31564 was scarcely inactivated in the culture broths of FR-31564-resistant strains. All of the FR-31564-resistant mutants of P. aeruginosa came under the classification of strains lacking an L-alpha-glycerophosphate transport system.

Antibiotic resistance of indole-positive Klebsiella pneumoniae

Resistance patterns to antibiotics differed markedly between indole-positive and indole-negative Klebsiella pneumoniae strains. Multiple-drug-resistant strains were almost exclusively indole-negative. Ampicillin and kanamycin resistances in the indolepositive strains tested were not transmissible, whereas many of those resistances in the indole-negative strains were transmissible, together with other drug resistances to an Escherichia coli recipient. The substrate profile of the beta-lactamase from the indole-positive strains was fairly different from that of the beta-lactamase mediated by the ampicillin resistance plasmid.

Some properties of hog thyroidal membrane-bound adenosine tri-phosphatase: proteolytic activation of Mg-dependent activity

The ATPase preparations from the hog thyroid was preincubated with various amounts of trypsin. The activity of Mg-ATPase was consistently elevated. On the contrary, the Na, K-ATPase activity decreased with increasing amounts of trypsin. The effects were similar to those which were observed in the enzyme preparations treated with basis polyamino acids as previously reported. This phenomenon seemed to be specific in the preparations from the thyroid. The Mg-dependent activity was increased after pretreatment with trypsin or poly-L-lysine (PLL) when CTP, ITP and UTP were used as substrate. Thus the substrate specificity of Mg-ATPase was low. The enzyme-kinetics using ATP as substrate showed that the increase in activity was due to an increase in Vmax and not to a change in Km. The activity of Mg-ATPase was increased even after 30 min of preincubation with trypsin, while the Na, K-ATPase activity was almost diminished. These results suggest that the activity of Mg-ATPase in the preparation from the thyroid is specifically changed by the modification of the molecular environment of the enzyme with trypsin or basic polyamino acids.

Comparison of antibacterial activity of a new cephalosporin, ceftizoxime (FK 749) with other cephalosporin antibiotics

FK 749 is a distinctive new parenteral cephalosporin antibiotic with a broad antibacterial spectrum which is more potently active against a wide variety of Gram-negative bacilli, including the opportunistic pathogens such as Citrobacter and Enterobacter species and Serratia marcescens, than SCE 963, T 1551 and cefmetazole. The activity of FK 749 against Escherichia coli, Klebsiella pneumoniae, pyogenes was by far superior to that of the three other antibiotics. These test organisms were not resistant to FK 749. The antibacterial activity of FK 749 against Pseudomonas aeruginosa was almost the same as that of ticarcillin but was inferior to that of gentamicin and T 1551. The bactericidal activity of FK 749 against E. coli, K. pneumoniae and Proteus mirabilis was more potent than that of the three other antibiotics. FK 749, like cefmetazole, was extremely stable to beta-lactamases. In studies in mice, the therapeutic effect of subcutaneous injection of FK 749 against various infections due to Gram-negative bacilli was by far superior to that of SCE 963, T 1551 and cefmetazole, was almost the same as that of SCE 963 and cefmetazole against Staphylococcus aureus infection and that of ticarcillin against P. aeruginosa infection.

Ceftizoxime (FK 749), a new parenteral cephalosporin: in vitro and in vivo antibacterial activities

FK 749 is a new parenteral cephalosporin derivative which is more active against various gram-negative bacilli, including the opportunistic pathogens such as Enterobacter, Citrobacter species, and Serratia marcescens, than cephalosporins and cephamycins such as cefotiam, cefamandole, cefuroxime, cefotaxime, and cefmetazole. FK 749 was especially active against gram-negative organisms resistant to these related antibiotics. FK 749 was more potent in bactericidal activity than the other antibiotics, and the activity was clearly enhanced in the presence of 90% defibrinated rabbit blood. The therapeutic effect of subcutaneously injected FK 749 in mice infected with various gram-negative bacilli was far superior to that of cefotiam, cefamandole, cefuroxime, and cefmetazole and was almost the same as that of cefmetazole in mice infected with Staphylococcus aureus and that of ticarcillin in mice infected with Pseudomonas aeruginosa. FK 749 has, in general, nearly the same in vitro and in vivo antibacterial activities as cefotaxime. The former had more potent bactericidal activity in the presence of the blood than the latter and showed more excellent therapeutic effect than cefotaxime against infections caused by large inoculum sizes.

Antibacterial activity of ceftizoxime (FK 749), a new cephalosporin, against cephalosporin-resistant bacteria, and its stability to beta-lactamase

Antibacterial activity of FK 749 against ampicillin-resistant clinical isolates of Escherichia coli was compared with those of other newly developed cephalosporins. FK 749 was the most active against strains possessing R-plasmids specifying ampicillin resistance and those whose resistance was chromosomally determined. The susceptibility of ampicillin-susceptible E. coli to FK 749 was not decreased by transduction of ampicillin resistance-specifying plasmids. However, most of the transconjugants acquired a high level of resistance to cefoperazone and cefamandole and a moderate level of resistance to cefoperazone and cefamandole and a moderate level to cefotiam. FK 749 was highly stable to both penicillinase- and cephalosporinase-type beta-lactamases, including R-plasmid-mediated beta-lactamase. Its level of resistance to beta-lactamases was comparable to those of cefoxitin, cefmetazole, and cefotaxime, slightly superior to that of cefuroxime, and much superior to those of cefotiam, cefamandole, and cefoperazone.

Inhibitory effect of Pseudomonas aeruginosa on the phagocytic and killing activity of rabbit polymorphonuclear leukocytes: mechanisms of action of a polymorphonuclear leukocyte inhibitor

The polymorphonuclear leukocyte (PMN) inhibitor isolated from a strain of Pseudomonas aeruginosa which is resistant to the phagocytic and killing activities of rabbit PMN inhibited migration of PMN and engulfment of latex particles by PMN. In studies of the bactericidal metabolism of PMN, the PMN inhibitor did not inhibit the intracellular activity and extracellular release of lysosomal enzymes. However, the PMN inhibitor caused a decrease of Nitro Blue Tetrazolium reduction. The PMN inhibitor had a cytotoxic effect on PMN and inhibited [14C]tyrosine uptake in intact PMN inhibitor had no inhibitory effect on protein synthesis in cell extracts.

Inhibitory effect of Pseudomonas aeruginosa on the phagacytic and killing activities of rabbit polymorphonuclear leukocytes: purification and characterization of an inhibitor of polymorphonuclear leukocyte function

A clinically isolated strain of polymorphonuclear leukocyte (PMN)-resistant Pseudomonas was found to produce an extracellular substance (PMN inhibitor) that inhibits the phagocytic and killing activities of PMN. The PMN inhibitor was purified from culture filtrates by precipitation with (NH4)2SO4 and chromatography on phosphocellulose, diethylaminoethyl-cellulose, and Sephadex G-100. The preparation was homogenous as judged by disc gel electrophoresis. The purified PMN inhibitor appeared to be a protein with a molecular weight of approximately 65,000 that was inactivated by heating and by exposure to a proteolytic enzyme.

Turner's syndrome with a duplication-deficiency X chromosome derived from a maternal pericentric inversion X chromosome

A 31-year-old woman of short stature with severe oligomenorrhea was found to carry a duplication-deficiency X chromosome, 46,X,rec(X)dup q,inv(X)(p22q11), inherited from her mother who carried a pericentric inversion X chromosome, 46,X,inv(X)(p22q11). By a combination of autoradiography and BUdR incorporation, the duplication-deficiency X chromosome was always found to be the inactive and late replicating one. In the cultured fibroblasts with the recombinant X chromosome, some of the cells were seen to have bipartite X chromatin bodies. In the mother with inv(X), the normal and the inverted X chromosome were inactivated at random.