Metabolism of 2,4-dinitrotoluene by Salmonella typhimurium strains TA98, TA98NR and TA98/1,8-DNP6, and mutagenicity of the metabolites of 2,4-dinitrotoluene and related compounds to strains TA98 and TA100

The products detected in the incubation of 2,4-dinitrotoluene (2,4-DNT) with Salmonella typhimurium strains TA98 and TA98/1,8-DNP6 were nitrosonitrotoluenes, hydroxylaminonitrotoluenes, aminonitrotoluenes and dimethyl dinitroazoxybenzene. The capacity of TA98NR to reduce 2,4-DNT was much lower than that of TA98 and TA98/1,8-DNP6. The bacterial products showed no mutagenic activity in the Ames assay using TA98 and TA100. These results indicate that the lack of mutagenic activity of 2,4-DNT is not due to low reductive metabolism of 2,4-DNT by the bacteria, but to the lack of mutagenic activity of the bacterial reductive products of 2,4-DNT, including dimethyl dinitroazoxybenzene.

[Interaction of the hypnotic lormetazepam with central benzodiazepine receptor subtypes omega 1, omega 2 and omega 3]

To clarify the action of lormetazepam, 3-hydroxybenzodiazepine, on the benzodiazepine (BZ) receptor subtypes, effects of lormetazepam on motor performance in the traction test and hexobarbital-induced loss of righting reflex in mice and the binding to BZ receptor subtypes were investigated in comparison with those of other BZ hypnotics. Lormetazepam prolonged the duration of hexobarbital-induced loss of righting reflex. The minimal effective dose (1 mg/kg, p.o.) was higher than that of flunitrazepam, lower than those of diazepam and zopiclone, and the same as those of triazolam and brotizolam. Lormetazepam showed the ataxic effect at 10 mg/kg, p.o., but the separation between its effective doses for the hypnotic and ataxic effects was the largest among the hypnotics tested. In the displacement study on [3H]flumazenil binding to cerebellar and spinal cord membranes, lormetazepam bound with a higher affinity to omega 1 receptor (Ki = 10 nM) than to omega 2 receptor (Ki = 29 nM). The GABA-ratios of lormetazepam to omega 1 and omega 2 receptors were 3.9 and 4.0, respectively; and they were higher and lower than those of flunitrazepam to omega 1 and omega 2 receptors, respectively. In the displacement study on [3H] Ro5-4864 binding to kidney membranes, lormetazepam bound with a lower affinity to the omega 3 receptor (Ki = 213 nM) than flunitrazepam. Thus, lormetazepam was suggested to be a potent hypnotic with weaker ataxic effects than other BZ hypnotics, which may be due to its selective and potent agonistic action on central omega 1 receptors.

Synthesis of 5-keto-5-oxime derivatives of milbemycins and their activities against microfilariae

Starting from milbemycin D (1), milbemycin A4 (2) and milbemycin A3 (3), a series of 5-keto-5-oxime derivatives were synthesized by selective oximation at the alpha,beta-conjugated carbonyl function of the 5-ketomilbemycins (4-6). The activities of the synthesized compounds were studied in dogs naturally infested with microfilariae of Dirofilaria immitis. The 5-keto-5-oximes of milbemycin D (7), A4 (8) and A3 (9) had quite high efficacy to control the microfilariae and more potency than their parents, while the 5-O-acyl oximes (11-15) also exhibited high activity.

Cross-resistance patterns in ACNU-resistant glioma sublines in culture

Three ACNU-resistant clones (R1, R3, and R12) were isolated from 9L rat glioma cells under selection pressure of ACNU in vitro. The authors have investigated the mechanisms of resistance and characteristics of these clones at the cellular level by studying cross-resistance patterns to chemical and physical agents. Although these resistant sublines showed complete cross-resistance to methyl-chloroethylnitrosourea (MCNU), no cross-resistance was observed for other alkylating agents, while each of the resistant sublines showed partial cross-resistance to structurally dissimilar toxic agents (vinblastine, Adriamycin, and VP-16). No difference in ACNU uptake was observed between 9L and R3 cells, and resistance patterns among alkylating agents suggested that the mechanism of ACNU resistance was specific to bifunctional nitrosoureas. Based on a transport study, this multidrug resistance could be explained by reduced intracellular uptake of these drugs, but there seemed little possibility that membrane P-glycoprotein, which usually is observed in typical multidrug-resistant cells, was expressed in these ACNU-resistant cells because enhanced drug efflux was not found in ACNU-resistant sublines. Significant collateral sensitivity to L-asparaginase indicated that ACNU might disturb the asparagine synthetic pathways by its mutagenic action. The increased level of total glutathione in the resistant sublines may be one mechanism of radiation or ACNU resistance.

Glutathione and cellular response of ACNU-resistant rat glioma sublines to drugs and radiation

Three ACNU-resistant sublines (R1, R3 and R12) from rat glioma 9L cells showed cross-resistance to vinblastine, adriamycin, and VP-16. Among these, the R3 subline also acquired radioresistance under aerobic conditions. Total glutathione levels in these sublines were elevated 2- to 3-fold. Treatment of the cells with BSO, a specific inhibitor of GSH synthesis, resulted in decreased intracellular total glutathione levels in all 4 cell lines to about 10% of control levels. However, sensitivity to radiation or to chemicals did not change accordingly. Treatment of 9L cells with OTZ, a precursor of cysteine, resulted in a rise in intracellular GSH levels but it did not correlate with sensitivity to X-ray or to ACNU. These results suggest that, in terms of cellular sensitivity to radiation or ACNU, total glutathione level alone cannot serve as a predictive indicator.

Comparison of the acute hemodynamic and coronary vasodilating effects between nicorandil and glyceryl trinitrate

Acute hemodynamic and coronary vasodilating effects of nicorandol (SG-75, Sigmat; CAS 65141-46-0) and glyceryl trinitrate (GTN, nitroglycerin) were examined in 20 subjects under cardiac catheterization and coronary arteriography. Nicorandil 4 mg i.v. produced significant increases in heart rate, cardiac index and stroke volume index and significant decreases in systolic, diastolic and mean blood pressure, pulmonary capillary wedge pressure, left ventricular enddiastolic pressure, systemic vascular resistance and total pulmonary resistance. Degree of percent changes in these parameters by nicorandil were similar to that by GTN 0.3 mg i.v. Coronary vasodilating effects of both drugs were also at the same degree. Results indicate that nicorandil has cardiovascular and coronary vasodilating effects similar to those of GTN when administered intravenously.

Terguride, a dopamine D(2) partial agonist, as a discriminative stimulus in rats

Drug discrimination training with terguride, a 9, 10-transdihydrogenated derivative of lisuride, was carried out using a two-lever food-reinforced procedure (FR 10) in rats, to investigate its influence on central dopaminergic (DA) and serotonergic (5-HT) functions. The terguride (0.05mg/kg, i.p.) discrimination was established within 64 +/- 5 training sessions (mean +/- S.E.) and was stably maintained thereafter. Higher doses of terguride could not be used for discriminative training due to response disruption. In generalization tests with terguride, drug-appropriate responding increased dose-dependently and reached levels of 45 and 99% at 0.01 and 0.05mg/kg i.p. The D(2) agonist lisuride at low doses and the DA autoreceptor agonist (-)-3-PPP substituted for terguride. The DA agonist apomorphine and the 5-HT agonist 5-MeO-DMT produced dose-dependent but incomplete substitution. The D(1) agonist SKF38393, the DA antagonist haloperidol, the D(2) antagonist sulpiride, the D(1) antagonist SCH23390, the 5-HT(1A) agonist 8-OH-DPAT, the 5-HT(1B) agonist m-CPP and the 5-HT(2) agonist DOI were not generalized. In antagonism tests, sulpride completely blocked the terguride-appropriate response, but SCH23390 and the 5-HT antagonist methysergide did not. These results indicate that discriminative stimulus properties of terguride in rats are mediated primarily by activation of receptors with characteristics similar to those of presynaptic D(2) autoreceptors.

[Anxiolytic effects of lisuride and its agonistic action to central 5-HT1A receptors]

Effects of lisuride, a derivative of ergot alkaloid, on central 5-HT1A receptors were investigated biochemically, behaviorally and electroencephalographically (EEG) in rats and rabbits. Effects of lisuride in water-lick conflict tests were also investigated in rats. Lisuride was found to strongly inhibit the bindings of [3H]8-OH-DPAT to 5-HT1A receptors in the raphe nucleus, hippocampus, cortex, amygdala and hypothalamus of rat brain. Inhibitory effects of lisuride on bindings of [3H]8-OH-DPAT in the hippocampus was almost the same as that of 5-HT (Ki = 0.5 nM) and stronger than those of the 5-HT agonist 5-MeO-DMT (Ki = 2.1 nM) or other ergot derivatives (bromocriptine and pergolide, Ki = 3.0 nM). Lisuride (0.1-0.5 mg/kg, i.p.), like 8-OH-DPAT, dose-dependently induced a 5-HT behavioral syndrome in rats. Lisuride affected locomotor activity in rats, whereas 8-OH-DPAT did not. In hippocampal EEG of rabbits, lisuride (0.01-0.03 mg/kg, i.v.), like 8-OH-DPAT and diazepam, dose-dependently inhibited rhythmical slow activity (RSA) induced by acoustical stimulation (3100 Hz) and also inhibited the RSA increased by administration of anxiogenic FG7142. In water-lick conflict tests, lisuride (0.05-0.1 mg/kg, i.p.), like diazepam, increased the number of shocks. These findings indicated that lisuride acts as a strong agonist on central 5-HT1A receptors and suggested that lisuride might be a potential anxiolytic.

Determination of the antiplatelet agent. KB-3022, and its metabolite by high-performance liquid chromatography

A rapid, accurate and reproducible high-performance liquid chromatographic method for the simultaneous determination of a new antiplatelet agent, ethyl 2-[4,5-bis(4-methoxyphenyl)thiazol-2-yl]pyrrol-1-ylacetate (KB-3022), and its main metabolite, 2-[4,5-bis(4-methoxyphenyl)thiazol-2-yl]pyrrol-1-ylacetic acid (desethyl KB-3022), in biological fluids has been developed. KB-3022 and desethyl KB-3022 in plasma or urine were extracted with a mixture of n-hexane and dichloromethane (1:1), separated on a reversed-phase C18 column with a mixture of 0.01 M (NH4)2HPO4 (pH 3.0), acetonitrile and isopropyl alcohol as a mobile phase, and quantitated by ultraviolet absorbance measurement at 340 nm. 4-[2-(4,5-bis(4-methoxyphenyl)thiazol-2-yl)pyrrol-1-yl]butyric acid was used as an internal standard. The detection limit of KB-3022 in plasma was 3 ng/ml, and that of KB-3022 in urine and desethyl KB-3022 in plasma or urine was 1 ng/ml. The coefficients of variation for the determination of KB-3022 or desethyl KB-3022 in plasma or urine were below 5.6%. This method was applied to the determination of the plasma concentration of KB-3022 and desethyl KB-3022 after intravenous administration to rats.

The effect of bile salts on the oral mucosal absorption of human calcitonin in rats

The relationship between the inhibition of the degradation of human calcitonin (HCT) in the supernatant of the rat's oral mucosa homogenate and the promoting effect on the rat's oral mucosal absorption of HCT was investigated by using ten kinds of sodium bile salts. The promoting effects and the inhibition of the degradation by the dihydroxy bile salts were related to the hydrophobicity, respectively. The inhibition of the degradation of HCT was related to the promoting effect on the oral mucosal absorption of HCT in the presence of the dihydroxy bile salts and to the concentration of the bile salts. Furthermore, the micelle formed by the bile salts would be concerned with the inhibition of the degradation of HCT.

[Effects in animal models of depression of lisuride alone and upon coadministration with antidepressants]

Effects of lisuride, a central dopamine and serotonin agonist of the ergot type, in animal models of depression were investigated in comparison with those of desipramine, mianserin and rolipram. Lisuride, like desipramine and mianserin, inhibited reserpine-induced hypothermia in mice (0.5-5.0 mg/kg, i.p.) and suppressed muricide in olfactory bulbectomized rats (ED50 = 0.16 mg/kg, i.p.) in a dose-dependent manner. The anti-muricidal effect was slightly enhanced by the repeated administration of 0.25 mg/kg lisuride. Lisuride (0.05-0.25 mg/kg, i.p.), like desipramine, dose-dependently reduced the duration of immobility in rats forced to swim, and this effect was antagonized by haloperidol. The reduction of immobility time was enhanced by the repeated administration of lisuride; at the same time, the ambulation in rats increased. Furthermore, the immobility-reducing effects of desipramine and rolipram were markedly enhanced by the co-administration of a low dose of lisuride (0.025 mg/kg, i.p.), which by itself had no effect on the immobility time. These results indicate that lisuride may be useful for the treatment of depression and indicate that a low dose of lisuride may enhance the clinical effectiveness of antidepressants such as desipramine.

[Pulmonary embolism as a complication in neurosurgical patients]

The overall incidence of pulmonary embolism (PE) among neurosurgical in-patients, whose ages ranged from 23 to 80, was 0.7%. Our report here is based on five cases of patients with PE. Four of these five patients were over 50 years of age. They had been admitted because of such reasons as brain tumor, spinal cord injury, intracerebral hematoma, and venous sinus thrombosis. Deep vein thrombosis (DVT) was seen in four but none were diagnosed before they had developed PE. Decreased level of consciousness and prolonged bed rest appeared to be common risk factors for PE. Mean duration between admission and onset of PE was 31 days. Although non-specific, tachycardia, tachypnea and hypoxemia were the most common signs and symptoms. As a definitive diagnostic procedure, pulmonary angiography was performed in most of cases. One patient required surgical embolectomy and others were treated with anticoagulation or fibrinolytic agents. In order to prevent recurrent thromboembolic phenomena, ligation of the inferior vena cava was a useful mode of treatment when anticoagulation was not indicated. And this approach seemed to be valid in most neurosurgical patients. We conclude that PE and DVT were not uncommon complications among Japanese neurosurgical patients and they can be treated successfully in collaboration with a cardiovascular surgeon if the diagnosis can be made correctly.

IS421, a new insertion sequence in Escherichia coli

The nucleotide sequence of a new insertion sequence (IS) in Escherichia coli, IS421, was determined. It is 1340 bp long and contains inverted repeats of 22 bp at its termini. It is flanked by 13 bp direct repeats apparently generated upon insertion. There are two ORFs longer than 200 bp in IS421. One can encode a polypeptide of 371 amino acids (aa) and the other, which is on the other strand, can encode a polypeptide of 102 aa. The C-terminal part of the 371 aa polypeptide shows some homology to that of transposases encoded in some other known IS elements. The copy number of IS421 in chromosomal DNA was 4 for E. coli K-12 and B, and 5 for E. coli C, as determined by the Southern hybridization of restriction fragments.

Molecular cloning and the nucleotide sequence of the Clostridium thermocellum trpE gene

The trpE gene of Clostridium thermocellum, a moderately thermophilic and absolutely anaerobic bacterium, was cloned by its ability to complement growth of an Escherichia coli tryptophan auxotroph (trpE) deficient in anthranilate synthase I. The nucleotide sequence of trpE and its flanking region was determined. The trpE gene overlapped at the termination codon with a putative initiation codon of trpG (trp[G]D), as deduced from the amino acid sequence homology with anthranilate synthase II of Serratia marcescens. S1-nuclease mapping of the trpE transcript produced in E. coli cells suggested that the promoter of C. thermocellum was utilized by E. coli. The amino acid sequence of anthranilate synthase I of C. thermocellum predicted from the nucleotide sequence is more similar to that of an extremely thermophilic bacterium, Thermus thermophilus HB8, than that of mesophilic bacteria.

Molecular cloning and nucleotide sequence of Thermus thermophilus HB8 trpE and trpG

The trpE gene of Thermus thermophilus HB8 was cloned by complementation of an Escherichia coli tryptophan auxotroph. The E. coli harboring the cloned gene produced the anthranilate synthase I, which was heat-stable and enzymatically active at higher temperature. The nucleotide sequence of the trpE gene and its flanking regions was determined. The trpE gene was preceded by an attenuator-like structure and followed by the trpG gene, with a short gap between them. No other gene essential for tryptophan biosynthesis was observed after the trpG gene. The amino-acid sequences of the T. themophilus anthranilate synthase I and II deduced from the nucleotide sequence were compared with those of other organisms.

The effect of additives on the oral mucosal absorption of human calcitonin in rats

The oral mucosal absorption of human calcitonin (HCT) was investigated in rats. Enhanced absorption of HCT was observed by coadministration of additives such as sodium deoxycholate, sodium tauroglycocholate, quillajasaponin (Quillayannin P-20), sodium lauryl sulfate, sodium myristate and sugar esters. The contribution of sugar esters to oral mucosal absorption of HCT was studied in some detail. The addition of a sugar ester having a hydrophilic-lipophilic balance value between 11 to 16 was found to be effective in increasing the absorption of HCT. Furthermore, it suggested that the type of constituent fatty acid of sugar ester was one of several important factors for the promotion of the oral mucosal absorption of HCT.

[The study of flomoxef in the pediatric field]

Flomoxef (FMOX; 6315-S), a new synthetic oxacephem antibiotic, was studied in the pediatric field and pharmacokinetic and clinical results obtained were summarized below. 1. The activity of FMOX against Staphylococcus aureus isolated from clinical patients, including latamoxef resistant strains was very high and MIC was approximately less than or equal to 0.39 microgram/ml. This MIC value was lower than other cephem antibiotics such as cefotaxime, cefotiam, cefmetazole, cefamandole. The distribution of MIC's of FMOX against Escherichia coli and Salmonella spp. ranged from 0.05 to 0.78 microgram/ml and from 0.05 to 0.39 microgram/ml, respectively. 2. Serum concentrations of FMOX after dosages of 20 mg/kg and 40 mg/kg with 1 hour intravenous drip infusion were 21.5-27.5 micrograms/ml, 6.00-7.81 micrograms/ml, 0.37-0.59 micrograms/ml at 1, 2, 5 hours after administration, respectively, and T1/2(beta) were 0.61-0.83 hour. Serum concentrations after one shot intravenous injection of 20 mg/kg FMOX were 56.7-90.2 and 0.20-0.26 micrograms/ml at 3-10 minutes and 6 hours after administration, respectively, T1/2(beta) was 1.22 hours and urinary excretion rate was 66.7-69.8% in 6 hours. 3. FMOX was administered to 32 cases (upper and lower respiratory tract infection, and purulent infections) at 3-4 times daily for 4-13 days. In these cases the daily dosage amounted to 41-119 mg/kg. Clinical effectiveness was 97% overall including resistance cases upon other cephem antibiotic treatment. All bacterial species identified including Branhamella catarrhalis, Streptococcus pyogenes, S. aureus, Streptococcus agalactiae, and Haemophilus influenzae were eradicated upon the treatment with FMOX. 4. Only 3 cases of soft stool, 1 case of elevated GOT and GPT, and 1 case of elevated GPT were observed, and all of these adverse reactions were normalized after the completion of treatment.

Amino-acid sequence of a tetrameric, manganese superoxide dismutase from Thermus thermophilus HB8

The amino-acid sequence of a tetrameric manganese superoxide dismutase from Thermus thermophilus HB8 has been determined. The protein was cleaved with cyanogen bromide (BrCN) into four peptides and their alignment was deduced through the fragment of partial cleavage with BrCN and the peptides were produced by cleavage of the protein with o-iodosobenzoic acid. Most of the peptides were sequenced by solid phase Edman degradation. Some of the peptides were sequenced by the Edman dansyl method after sub-fragmentation by proteinase digestion. The amino-acid sequence consists of 203 residues corresponding to a subunit molecular weight of 23,144.

[Evaluation of cefuzonam in the pediatric field]

Cefuzonam (L-105, CZON) was studied in pediatric infections. A summary of the results it as follows: For recently isolated Staphylococcus aureus strains, Peak MICs of CZON were distributed between 0.39 and 0.78 micrograms/ml showing a greater susceptibility of S. aureus to CZON than to cefoperazone (CPZ), latamoxef (LMOX), and cefmenoxime (CMX). Peak MICs of CZON for Escherichia coli were 0.10-0.20 micrograms/ml, similar to those of CPZ, LMOX, and CMX. Ampicillin (ABPC)-resistant strains were also susceptible to CZON. MICs for Salmonella were similar to those for E. coli. Peak MICs of CZON for Vibrio parahaemolyticus were 0.20-0.39 micrograms/ml. The susceptibility of the bacteria to CZON was far greater than to ABPC, and was similar to CPZ, LMOX, and CMX. With 20 mg/kg drip infusion, serum concentrations reached their peaks at the end of administration with values of 20.6-68.7 micrograms/ml, which decreased to 0.43-1.70 micrograms/ml after 2 hours. Half-lives of CZON in serum were 0.68-1.2 hours. With 50 mg/kg drip infusion, serum concentrations reached their peaks at the end of administration with levels of 69.0-82.0 micrograms/ml, and at after 2 hours 1.85-3.45 micrograms/ml. Thus, an apparent dose response was observed. Half-lives of CZON in serum were 0.63-0.99 hours. Urinary recovery rates in 6 hours were 39.9-80.5%. A total of 44 cases of 10 different types of acute pediatric infections was treated by CZON intravenous drip infusion as the main therapeutic procedure. The efficacy rate was 93.2%, and the compound was effective on purulent infections, acute urinary tract infection, etc. with pathogens such as ABPC-resistant S. aureus, E. coli, and Enterococcus faecalis. Dosage levels per day were 50 to 80 mg/kg in most cases. In infections with S. aureus (8 strains), Streptococcus pneumoniae (3 strains), E. faecalis (1 strain), Haemophilus parahaemolyticus (1 strain), Haemophilus parainfluenzae (2 strains), Haemophilus influenzae (11 strains), Bordetella pertussis (1 strain), E. coli (3 strains), a total of 30 strains, bacterial elimination was noted with an exception of 1 strain of S. aureus. The compound was used for 4 to 15 days, but side effects observed clinically were only 1 case of diarrhea and 1 case of thrombocytosis.

[Fundamental and clinical studies with imipenem/cilastatin sodium, a new carbapenem antibiotic, in the field of pediatrics]

Fundamental and clinical evaluations of imipenem/cilastatin sodium (MK-0787/MK-0791) were carried out in pediatric patients. The following results were obtained: After intravenous drip infusion of single doses of 10 mg/10 mg/kg to 20 mg/20 mg/kg of MK-0787/MK-0791 in children, peak plasma levels of MK-0787 ranged from 32.0 to 82.0 micrograms/ml at the end of the infusion. The half-life was 49.9 to 64.0 minutes. The cumulative urinary recovery at 6 to 7 hours after the 1 hour drip infusion ranged from 65.5 to 88.9%. Fecal levels of MK-0787 were 4.2 and 23.1 micrograms/g at 6 hours after a 30-minute intravenous drip infusion of 200 mg/200 mg of MK-0787/MK-0791. MK-0787/MK-0791 was administered by intravenous drip infusion to patients with purulent meningitis. Penetration into the cerebrospinal fluid was satisfactory, as were the clinical responses. MK-0787/MK-0791 was administered clinically in doses of 30 mg/30 mg/kg/day to 200 mg/200 mg/kg/day by intravenous drip infusion 3 or 4 times a day for 3 to 22 days to 26 patients with acute pediatric infections. The clinical response was excellent in 18 patients and good in 8 patients. Eradication occurred with 16 isolates; only two strains of Salmonella-B were not eradicated. Anorexia in 1 patient was the only clinical adverse effect reported, and the only adverse effects found in laboratory tests were eosinophilia and thrombocytosis in 1 patient, respectively, and elevation of the S-GOT and S-GPT in 1 patient.