Analysis of bile acids by micro high-performance liquid chromatography with postcolumn enzyme reaction and fluorometric detection

Free and conjugated bile acids in human sera were analyzed by micro high-performance liquid chromatography with detection by an immobilized hydroxysteroid dehydrogenase postcolumn reaction and a spectrofluorometer. Bile acids could be effectively collected on a precolumn, 10 X 0.2 mm I.D., packed with silica-ODS (octadecylsilane), by passing a dilute phosphate solution of a serum through it. The detection limit was 0.13-0.28 pmole for a single-to-noise ratio of 2. An amount of 0.1 ml of serum was enough for analysing each bile acid in it.

[Experimental study on the action mechanism of a new bronchodilator agent, BB-1502]

The action mechanism of the bronchodilator activity of BB-1502 was studied in comparison with aminophylline. Orally administered BB-1502 did not inhibit passive cutaneous anaphylaxis in rats, an immediate allergic reaction of Type I, but strongly protected the same antigen-mediated anaphylactic asthma by the intraduodenal route, the activity being approximately 13 times more potent than that of aminophylline. BB-1502 also inhibited IgG-mediated anaphylactic asthma in guinea pigs by the oral route. Both IgE- and IgG-mediated histamine releases from rat lung were similarly inhibited by BB-1502, the potency being 2--3 times that of aminophylline. Disodium cromoglycate showed specific inhibition of the IgE-mediated reaction. BB-1502 and aminophylline showed nonspecific inhibition of the spasms of guinea pig ileum elicited by histamine, acetylcholine and BaCl2. Both compounds inhibited cyclic AMP and cyclic GMP phosphodiesterases (PDEs) derived from guinea pig organs. BB-1502 specifically inhibited the cyclic AMP PDE of lung and brain origins, while aminophylline showed no such specificity. The results of the present study suggested that the bronchodilator and anti-asthmatic actions of BB-1502 might, at least in part, be due to the regulation of cyclic nucleotide PDEs.

Purification and fluorometric assay of proteinase A from yeast

Proteinase A was purified from commercial baker's yeast to homogeneity by using affinity chromatography. Simple and sensitive fluorometric assay procedures were developed for this enzyme, where Suc-Arg-Pro-Phe-His-Leu-Leu-Val-Tyr-4-methylcoumaryl-7-amide and dimethylcasein were used as synthetic substrate and protein substrate, respectively. Proteinase A cleaved the former substrate at the Leu-Val bond. The extent of the cleavage was monitored by measuring the amount of fluorescent 7-amino-4-methylcoumarine produced by the successive cleavage with an auxiliary enzyme, aminopeptidase M, or by measuring the fluorescence generated by the reaction of newly formed amino groups with fluorescamine. In the assay with the latter substrate, the amounts of newly formed amino groups were measured by the reaction with fluorescamine. The optimal pH of the reaction was 5.0 to 5.5. The methods were applied to the study of the effects of denaturing agents on the activity of proteinase A.

[Pharmacokinetics of a new antitumor antibiotic, neothramycin, after intrapleural administration]

In 5 patients with malignant pleural effusion, neothramycin (NTM) was intrapleurally administered at a dose of 30 mg in 3 cases and 40 mg in 2 cases and the pharmacokinetics was studied by using compartment models. The results were as follows: 1) Pleural levels of NTM were described by a mono-exponential equation and the half-life ranged from 3.45 to 6.48 hr. 2) The time to reach the maximum plasma level was 1 to 2 hr after pleural administration. The maximum levels were 54 to 106.4 ng/ml with the 30 mg dosage and 74.7 to 79.2 ng/ml with the 40 mg dosage, followed by a slow decline, with T1/2 ranging from 6.54 to 17.80 hr. 3) The elimination half-life of NTM in the plasma after intrapleural administration was much longer than that after intravenous administration. This phenomenon can be explained by a "flip-flop model": in this case, the rate of transfer from the pleural space to the plasma was much slower than that of the elimination from the plasma. 4) The parameters, K1 and K2, which were obtained by the deconvolution method, seemed to reflect the transfer of NTM between the pleural space and the plasma. 5) In 3 out of the 4 evaluable cases, an extreme decrease in the pleural fluid volume and suppression of reswelling were observed, including a case found to be negative for tumor cells upon cytodiagnosis.

Cerebral vasodilation and spasmolytic activity of diltiazem in anesthetized animals

The effects of diltiazem on the cerebral blood flow and cerebrovascular spasm were studied in pentobarbital anesthetized animals. In Rhesus monkeys, the common carotid and internal carotid blood flow were measured by an electromagnetic flowmeter. Diltiazem (10-300 micrograms/kg, i.v.) dose-dependently increased both the common carotid and internal carotid blood flow, and the increase in internal carotid blood flow persisted for a longer period than that in the common carotid blood flow. In dogs, regional blood flow in the cerebral cortex (rCBF) was measured by means of the hydrogen gas clearance method. Diltiazem (20 micrograms/kg/min, i.v.) increased rCBF by about 20% of the control during the infusion, and the increase in rCBF was still continued 40 min after the infusion was stopped. In cats, the basilar artery was exposed by craniotomy through the transcervico-transclival approach, and vasospasm was induced by topical administration of 5-HT, PGF2 alpha and incubated blood. Diltiazem, either applied topically to the artery (100 micrograms/ml) or infused continuously into the femoral vein (20 or 40 micrograms/kg/min), suppressed the vasoconstriction evoked by the spasmogen.

[Change of pattern of gastric emptying after selective proximal vagotomy]

The patterns of gastric emptying after selective proximal vagotomy (SPV) and SPV with pyloroplasty (SPV + D) were studed using a liquid labelled with 99mTc-DTPA. By means of on-line computer facility, it was possible to analyse the relative role of the Whole stomach and the antrum within the overall frame work of gastric emptying. In the time/activity curve of the whole stomach, all of 3 groups emptied in exponential curve. Comparing with normal subjects, SPV subjects were tending to empty slowly, while SPV + D subjects were tending to empty rapidly. In the time/activity curve of the antrum, normal and SPV + D subjects had two types of emptying--one was represented in the decreasing curve and another was represented in the increasing-decreasing curve. While SPV subjects had only one type of emptying which was represented in the increasing-decreasing curve. From a consideration of the pattern of gastric emptying curve, SPV subjects had two different emptying states compared with normal subjects--one was the delay of entering the antrum from the fundic side of stomach, and the other was that effective antral emptying did not readily start. While SPV + D kept more neally normal gastric emptying that it of SPV.

A study of esterase--its application to biotransformation of midecamycin derivatives

Esterases of intestinal mucosa and liver from human and rat were used to study the biotransformation of midecamycin derivatives. In the in vitro experiment with rat esterases, the 4"-acyl derivatives were more easily hydrolyzed than the 9-acyl derivatives. Among the 9-acyl esters, the highest hydrolytic activity was observed with butyrate. In the in vivo experiment, when the rats were administered with the derivatives of 4"-depropionylmidecamycin (M1) orally, comparatively more 9-acyl metabolites were excreted in the urine, but the amount of the 4"-acyl metabolites was very small. In the in vitro experiment with human esterases, the 9-acyl esters were hydrolyzed more easily than the 4"-acyl esters. Among the 9-acyl esters of M1, the highest hydrolytic activity was observed with butyrate. When the 9-acyl esters were administered to humans, the n-butyl ester was hydrolyzed faster than the acetyl ester. When the 9,4"-diacetyl ester was administered to humans, comparatively more 4"-acyl metabolites were excreted in the urine. These results suggest that the experiment with the use of these esterases is useful to estimate the biotransformation of midecamycin derivatives.

[Tissue distribution of 9, 3"-diacetylmidecamycin in the pregnant rat and in the rat following repeated administration (author's transl)]

The tissue distribution of 9, 3"-diacetylmidecamycin (MOM) was studied in the pregnant rats and in the rats following repeated administration. After oral administration of MOM (200 mg/kg) in the pregnant rats, the levels in the placenta and in the uterus were 2-3 times higher than that in the blood, however the levels in the amniotic fluid and in the fetus were 1/10-1/20 of the blood levels. After the third administration of MOM in the first day (30 mg/kg p.o./dose, 3 times/day, 4-hour interval), the levels in the liver, kidney, lungs, spleen, salivary glands and thymus were 1.5-12 times higher than that in the blood; the level in the muscle was almost equal to that in the blood; and the levels in the brain were 1/3-1/10 of the blood level. The tissue distribution patterns after repeated administrations were found to be similar to those of the first day administrations.

[Effect of acetyllactoylcholine-1,5-naphthalene disulfonate on the motility of stomach]

The effect of TM-723 on the motility of stomach was investigated by using the electromyogram, extraluminal strain gauge force transducer in dog and by measuring the human gastric emptying time. Three mongrel dogs were equipped with two bipolar electrodes on the serosal surface of the antrum and single bipolar electrode and single strain gauge on the surface of the body. Both the peristaltic spike discharge and contractile activity were recorded during 30 minutes before and 60 minutes after administration of TM-723 1 mg/kg, 3 mg/kg and 5 mg/kg, iv. The peristaltic spikes were suddenly disappeared on administration of TM-723 and after then, recurrent peristaltic spikes were recognized with prolonged interval and increased propagation velocity for about four minutes. The contractile activity increased with the administration of TM-723 for a minute. Gastric emptying time were measured on four healthy men by using of the test meal containing 300 muCi of 99mTc-DTPA before and after administration of TM-723 50 mg per os. The following results were obtained that three of four men had accelerated emptying time and one had no remarkable changes after taking TM-723. These studies suggest that TM-723 activates the motility of the stomach.

Electrochemical and ESR studies on Cu(II) complexes of bleomycin and its related compounds

The 1:1 Cu(II) complexes of bleomycin (BLM) A2, BLM B2, epi-BLM B2, iso-BLM B2, depyruvamide-BLM A2, deglyco-BLM B2 and the structurally related peptides (P-5m, P-3A and P-3) have been comprehensively investigated by ESR and electrochemical methods. ESR spectra for Cu(II) complexes of BLM A2, epi-BLM B2, depyruvamide-BLM A2 and P-3 revealed the axially symmetric g-anisotropies. In contrast, ESR features of the iso-BLM B2, deglyco-BLM B2, P-5m and P-3A complexes, which lack the sixth ligation by the 3-O-carbamoyl group of mannose, exhibited rhombic g-anisotropies with decrease of the A parallel values. The cyclic voltamograms showed that all of the Cu(II) complexes underwent the well defined quasi-reversible one-electron Cu(II)/Cu(I) coupled redox reaction. The inverse of the redox potential, which measures the effective strength of the ligand field splitting, gave a linear relation with the observed g parallel value of each Cu(II) complex except for depyruvamide-BLM and P-3. The present results confirmed that the 3-O-carbamoyl group of the mannose moiety of the BLM molecule contributes to the stability of the metal site in BLM-Cu(II) complexes by ligation at the sixth coordination site.

Pharmacological studies on BB-1502, a new bronchodilator

The pharmacological activities of BB-1502 (9-cyclohexyl-2-n-propoxy-9H-adenine), a potent bronchodilator and inhibitor of cyclic AMP phosphodiesterase, were compared with those of aminophylline in a number of biological systems. IOn vitro, BB-1502 relaxed guinea pig tracheal tissue at a concentration ca. 600 times lower than that required for aminophylline. The ability of BB-1502 to inhibit cyclic AMP phosphodiesterase of guinea pig lung origin was 15 times greater than that of aminophylline. The direct bronchodilator activity of BB-1502 determined in guinea pigs by the intraduodenal route was 5 times greater and the duration of the action longer than that of aminophylline. In dogs, intraduodenal BB-1502 inhibited bronchoconstriction induced by pilocarpine, histamine, or acetylcholine and the activity of the new compound was 4 to 7 times more potent than that of aminophylline. In experimental asthma studies, orally administered BB-1502 protected guinea pigs from allergy-induced asthma provoked by an antigen challenge with aerosolized egg albumin and here the potency was 4 times greater that that of aminophylline. Ascaris antigen-induced asthma in dogs was completely inhibited by the oral administration of BB-1502 in a dose of 1 mg/kg with significant protection seen at 0.3 and 0.1 mg/kg. No complete protection was obtained with aminophylline in the dog asthma model. Cardiovascular effects observed with guinea pigs and dogs following the oral administration of BB-1502 were considerably less than those seen with aminophylline. CNS side effects were nil in rats when BB-1502 was given at 3 times the dose that produced significant stimulation by aminophylline. Acute lethal toxicity determined in mice by the oral route was similar for BB-1502 and aminophylline.

[Bronchodilator actions of diltiazem in vitro and in vivo (author's transl)]

Bronchodilator effects of diltiazem were investigated in the isolated guinea pig tracheal chain and in the anesthetized cat. Interaction of diltiazem with isoproterenol (iso) was also examined. Diltiazem (10(-4) g/ml) relaxed by 70% the tracheal chain contracted by histamine, 10(-5) g/ml. This effect of diltiazem was not affected by pretreatment with propranolol, 3 X 10(8) g/ml. Diltiazem (400 microgram/kg, i.v.) diminished by 20% the elevation of intratracheal pressure induced by serotonin aerosol, the effect of which lasted for approximately 20 min. On the other hand, diltiazem (10(-5) g/ml) produced no influence on the iso-induced relaxation of the guinea pig trachea. In the anesthetized dog, diltiazem (20 microgram/kg/min, i.v.) did not affect the iso-induced bronchodilation when histamine was used as a spasmogen, while the positive chronotropic action of iso was diminished. On the contrary, propranolol (30 microgram/kg, i.v.) potentiated the bronchoconstrictor effect of histamine and suppressed both the bronchodilating and positive chronotropic actions of iso. Thus, the effects of diltiazem differed from those of propranolol. In summary, diltiazem showed bronchodilation both in vitro and in vivo, although the activity was not so potent, With regard to the iso-induced bronchodilation, diltiazem had no effect at a dose which diminished the positive chronotropic action of iso.

Acute toxicity and pharmacokinetics of dibekacin mice

The LD50 values of dibekacin to mice were determined following three different methods of administration, namely, intravenous constant infusion, intravenous bolus injection, and intramuscular injection. The serum levels of dibekacin were pharmacokinetically analyzed. The differences in LD50 values between the methods of administration were discussed from the viewpoints of pharmacokinetics. 1) The LD50 value following the intravenous constant infusion was higher than that following the intravenous bolus injection and approached the level of that following the intramuscular injection, when the infusion rate of the drug was decreased by increasing the infusion period. 2) The biological half-life of dibekacin in mice was 24--45 min. 3) The volume of distribution increased as its dose increased, and a linear correlation was noted between log Vd and log (dose). 4) The difference among the maximum serum concentrations calculated with dibekacin following the administration of LD50 was small, which coincided with the results of the experiment that the serum concentrations of dibekacin at the death following the administration of LD100 were almost the same regardless of the method of administration.

Pharmacokinetics of dibekacin in rabbits and dogs

The behaviors of dibekacin after three administration methods to rabbits and dogs were pharmacokinetically analysed. 1) In both rabbits and dogs, the pharmacokinetic constants for the intravenous constant infusion and intramuscular injection were similar to each other, and the serum levels after the intravenous constant infusion for 1 hr were similar to those after the intramuscular injection except the peak time. 2) In both rabbits and dogs, Vd increased with the dose and a linear correlation was noted between log Vd and log (dose). 3) The tissue concentrations of dibekacin decreased with the decrease in the serum concentration. 4) A correlation equation, log T 1/2 = 0.194 . log B + 1.128, was obtained, where T 1/2 and B represent the biological half-life of dibekacin and the body weight of animals, respectively. It was suggested that the pharmacokinetic behaviors of dibekacin in human beings can be predicted from the results of the animal experiments.

[Effects of diltiazem on hemodynamics and His bundle electrogram in the anesthetized dog (author's transl)]

Effects of diltiazem, a calcium antagonist, on the cardiovascular system in the pentobarbital anesthetized dogs were investigated. Diltiazem (100 micrograms/kg and 300 micrograms/kg, i.v.) decreased blood pressure, heart rate and total peripheral resistance, while cardiac output and stroke volume were markedly increased. The max dp/dt of left ventricular pressure tended to increase with a dose of 100 micrograms/kg. Left ventricular end-diastolic pressure was slightly increased with a dose of 400 micrograms/kg. Rate pressure product was significantly reduced. Diltiazem (30 micrograms/kg and 100 micrograms/kg) increased pulmonary arterial flow together with the increase in both systolic and diastolic pulmonary arterial pressure. Diltiazem (100 micrograms/kg) increased common carotid, femoral and superior mesenteric arterial blood flow by 30 to 40%, whereas vertebral blood flow was increased by over 100%. The dose dependency in the vertebral blood flow was remarkable. Response of the vertebral artery to diltiazem was similar to that reported in the case of the coronary artery. In the His bundle electrogram, diltiazem increased the AH interval by about 10% at 100 micrograms/kg and 25% at 200 micrograms/kg, without changing the HV interval. Diltiazem-induced AH prolongation was completely depressed by epinephrine but only partially so by CaCl2. Thus, the effects of diltiazem on sinus rhythm and AV conduction in the anesthetized dog were more potent than the effects on cardiac contractility, although weaker than the effects of the vasodilating action. The vasodilator effects appear to be the primary action of diltiazem on the cardiovascular system.

Developmental process of chronic subdural collections of fluid based on CT scan findings

One hundred twenty-four follow-up scans were performed on 24 patients who had had posttraumatic subdural collections of low density. Of the 24 patients, 6 developed chronic subdural hematomas. Six other subdural collections showed a temporary increase in attenuation but eventually resolved. The remaining 12 subdural collections resolved without apparent increase in density. Illustrative cases are presented with computed tomographic scans. The identity of these posttraumatic subdural lesions of low density is discussed. They seem to be posttraumatic subdural hygromas.

[Mechanism of action of certain fibrinolytic bis-tetrahydroisoquinolines: their antagonists and histamine- and 5-hydroxytryptamine-releasing effects (author's transl)]

1, 1'-Heptamethylene-bis-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline (HBDT) and 1, 1'-tetramethylene-bis-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline (bisobrin) produced an edema when given subcutaneously into the hind paws of rats. The inhibitory effects of various antagonists on the paw edema and fibrinolysis induced by HBDT were examined in rats to determine whether chemical mediators other than histamine were involved. The relation of histamine to the fibrinolytic activity of these bis-tetrahydroisoquinoline derivatives has already been reported. Both edema and fibrinolysis were significantly inhibited by pretreatment with promethazine, cyproheptadine or phentolamine, but not by dibenamine, propranolol, atropine, indomethacin or pyridinolcarbamate. epsilon-Aminocaproic acid inhibited the fibrinolytic activity completely without any effect on the paw edema. HBDT released 5-hydroxytryptamine (5-HT) along with histamine from rat peritoneal mast cells. However, the amount of released 5-HT was considerably smaller than that of histamine. These results suggested that bis-tetrahydroisoquinolines released both histamine and 5-HT and that these mediators produced paw edema and induced fibrinolysis by enhancement of plasmin production.

Three additional examples of anti-Xga and Xg blood groups among the Japanese

Three examples of anti-Xga identified in Japanese donors are reported. Two of these were stimulated by pregnancy, while the antibody stimulation of the other one remains unknown. All of these antibodies had the ability to bind complement. A dosage effect was observed in an anti-Xga serum. The Xga gene frequency for 529 unrelated Japanese was 0.681, similar to that for Caucasians. Tests on 125 Japanese families with 242 offspring for Xga antigen are also reported.

[Hypotensive effects of diltiazem hydrochloride in the normotensive, spontaneously hypertensive and renal hypertensive rats (author's transl)]

In conscious and anesthetized normotensive rats, intravenous administration of diltiazem (0.1--3 mg/kg) produced a dose-related decrease in blood pressure. Administration of diltiazem (1--50 mg/kg) into the duodenum of anesthetized rats also reduced the blood pressure in a dose related manner. In parallel with the change in blood pressure, the heart rate increased in conscious rats and decreased in anesthetized animals. Such an increase in the heart rate was suppressed by pretreatment with propranolol. Similarly, in conscious spontaneously hypertensive rats (SHR), diltiazem dose-dependently decreased the blood pressure and increased the heart rate after intravenous administration (0.03--1 mg/kg). Oral administration of diltiazem (100 mg/kg) also reduced the blood pressure of SHR. In addition, the progressive increase in blood pressure in young SHR was significantly suppressed by chronic oral administration of diltiazem (30 mg/kg). The blood pressure in conscious renal hypertensive rats was also decreased with diltiazem (50 mg/kg p.o.). On the other hand, it was demonstrated that the pressor responses to norepinephrine and angiotensin II in the anesthetized normotensive rats were non-competitively inhibited by intravenous administration of diltiazem at a dose which had no effect on the blood pressure.