Hepatic blood flow after acute biliary obstruction and drainage in conscious dogs

BACKGROUND AIMS

Obstructive jaundice is a factor which effects hepatic blood flow and the relative contribution of the hepatic arterial flow and portal venous flow. In this study, and were measured in conscious dogs and the influence of biliary obstruction and drainage was investigated.

MATERIAL AND METHODS

Hepatic arterial flow (HAF) and portal venous flow (PVF) after biliary obstruction and subsequent drainage were continuously measured in conscious dogs using implantable transit time ultrasonic flow-meters.

RESULTS

After biliary obstruction hepatic arterial flow rapidly increased compared to the pre-obstructed values(p < 0.01), while portal venous flow was significantly decreased (p < 0.01). Total hepatic blood flow was initially increased (p < 0.01) until 2 hours after obstruction. It then decreased gradually. After 2 weeks, it was less than the pre-obstructed values, but this was not significant. Biliary drainage was performed after 2 weeks. Hepatic arterial flow subsequently decreased (p < 0.01) and portal venous flow increased (p < 0.05). Blood flow did not change.

CONCLUSION

Biliary obstruction resulted in significant changes in liver circulation. Biliary drainage facilitated recovery from these changes.

The effects of intravenously infused catecholamines on hepatic blood flow in conscious dogs with experimental obstructive jaundice

This study was conducted to examine how the effects of dopamine and dobutamine on hepatic blood flow were influenced by obstructive jaundice in a conscious canine model. Prior to biliary obstruction, portal venous blood flow (PVF) increased in response to the infusion of either dopamine or dobutamine: dopamine infused at 8 micrograms/kg per min produced an increase of 19 +/- 0% in PVF, while dobutamine infused at 16 micrograms/kg per min produced an increase of 30 +/- 2%. Although hepatic arterial blood flow (HAF) decreased dose-dependently in response to the infusion of dopamine, no significant change was observed in HAF in response to any dose of dobutamine. Obstructive jaundice attenuated or completely abolished the PVF-increasing effect of dopamine, whereas it did not significantly alter the effect of dobutamine on hepatic blood flow. In dogs with obstructive jaundice, dopamine at 16 micrograms/kg per min produced a decrease of 17 +/- 3% in PVF. These findings suggest that dobutamine is more effective than dopamine for increasing hepatic blood flow in patients with obstructive jaundice.

Design of a suitable formulation of FK613, a novel antiallergic agent, based on its pharmacokinetic and pharmacodynamic properties in healthy subjects

The pharmacokinetic and pharmacodynamic properties of FK613, a novel indolyl piperidine derivative, were investigated after oral administrations of 5, 10 and 20 mg in hard gelatin capsules to healthy male volunteers. FK613 was rapidly and almost completely absorbed, and >89% was recovered in the urine as the unchanged form. The urinary excretion of FK613 was linearly correlated with plasma concentration and its low water solubility was the main concern regarding the safety. In another experiment using a double-blind crossover design, in which 0 (placebo), 5 and 20 mg FK613 were administered to determine the plasma concentration-effect relationship, suppression of the intradermal histamine-induced skin reaction by FK613 was observed. Thus, the maintenance of a plasma concentration of FK613 in the range of 80-250 ng center dot ml-1 was recommended to ensure the suppression of histamine-induced wheal by >50% and not to exceed the solubility in urine. To achieve this, a new hydrogel-type formulation of FK613 was developed, with the aim both of delaying its absorption, so as to suppress the sharp rise in plasma concentration, and of maintaining the effective concentration for a longer period of time. This formulation was administered after meals at the doses of 20, 30, 40, 50 and 60 mg, and at repeated doses of 40 mg twice daily for 6.5 days to evaluate the pharmacokinetics and safety in healthy subjects. The area under the plasma concentration curve increased linearly with dose, whereas maximum plasma concentration (Cmax) tended to peak as dose increased, indicating the desirable properties of this formulation. Although Cmax exceeded 250 ng/ml at doses of 30 mg or more, no urinary crystal formation was observed on careful inspection of urine.

Single- and multiple-dose pharmacokinetics of AM-1155, a new 6-fluoro-8-methoxy quinolone, in humans

The pharmacokinetics of AM-1155, a new 6-fluoro-8-methoxy quinolone, was examined in healthy male volunteers after the oral administration of a single dose of 100, 200, 400, or 600 mg and multiple doses of 300 mg twice daily for 6.5 days (13 total doses). Throughout the whole study period, AM-1155 was well tolerated in every subject. In the single-dose study, the concentrations in serum reached a peak between 1 and 2 h, and the peak concentrations were 0.873, 1.71, 3.35, and 5.41 micrograms/ml at the doses of 100, 200, 400, and 600 mg, respectively. The elimination half-life was 7 to 8 h, independently of the doses. The unchanged drug was excreted mainly in the urine, with 82 to 88% of the doses appearing for 72 h. The fecal recovery of the unchanged drug amounted to 5.7% for 72 h after a single oral administration of a 400-mg dose. Urinary excretion of metabolites was minimal. The serum protein binding was 20%, independently of the concentrations in serum. The concentrations in saliva were approximately 80% of those in serum. The intake of food had no effect on the pharmacokinetic parameters and urinary excretion of AM-1155 except the slight decrease in area under the concentration-time curve. The concurrent administration of probenecid prolonged the elimination half-life, increased the area under the concentration-time curve, and decreased the apparent total body clearance, renal clearance, urinary recovery of unchanged drug, and the excretion ratio (intrinsic renal clearance of AM-1155/creatinine clearance). This indicated that the tubular secretion contributed to the renal excretion of AM-1155. In the multiple-dose study, the concentrations of AM-1155 in serum and urine reached a steady state within 2 to 3 days. The measured concentrations in serum fitted well the simulation curve, which reflected the persistence of linear pharmacokinetics of AM-1155. In conclusion, AM-1155 is expected to be clinically useful because of its potent antibacterial activity and favorable pharmacokinetics.

The effect of high-energy shock wave therapy combined with cisplatin on mouse hepatoma

It is well documented that high-energy shock waves (HESW) can produce antitumor effects in vivo and in vitro. Furthermore, because HESW can be focused on a limited area, this therapy is considered applicable to the treatment of localized cancer. In this study, we investigated the effects of HESW therapy combined with cisplatin (CDDP) on MH134 hepatoma in a mouse model. Tumor growth was inhibited by 1 mg/kg CDDP treatment in combination with 2,000 HESW administration, but not by 1 mg/kg CDDP treatment only. Moreover, the CDDP concentration in the tumor increased after HESW administration. The active oxygen induced by HESW was then investigated by the electron spin resonance system, and it was found that HESW generated hydroxy-radicals. As oxygen radicals have been reported to change cell membrane potential, it is supposed that active oxygen induced by HESW changes cell membrane permeability, and that CDDP is concentrated in the tumor. Therefore, the combined therapy with HESW and CDDP showed synergistic inhibitory effects on tumor growth.

Enhancement of the antitumor effect by combined use of high-energy shock waves and ATX-70

The antitumor effects of high-energy shock waves (HESW) in combination with ATX-70 [a gallium-porphyrin complex, 2,4-bis(1-decyloxyethyl)-Ga(III)-1,3,5,8-tetramethylporphyrin++ +-6, 7-dipropionyl diaspartic acid [sequence: see text] were investigated. In vitro, the cell damage to mouse MH134 hepatoma after HESW treatment was enhanced by adding ATX-70. In vivo, HESW and ATX-70 combination therapy inhibited cell growth. However, neither HESW treatment alone nor ATX-70 treatment alone inhibited cell growth. These results imply that the antitumor effects of HESW and ATX-70 combined therapy are caused by activation of ATX-70 by HESW.

Pharmacokinetic and pharmacodynamic analysis of a novel leukotriene biosynthesis inhibitor, MK-0591, in healthy volunteers

1. The pharmacokinetic and pharmacodynamic properties of a novel 2-indolealkanoic acid derivative (MK-0591), a potent inhibitor of leukotriene biosynthesis, were investigated in healthy male Japanese volunteers. Single oral doses of 50, 125, 250 and 500 mg and multiple oral doses of 125 mg twice daily for 9.5 days and 250 mg once daily for 10 days were administered. 2. After the single-dose administration following overnight fasting, Cmax and AUC of MK-0591 in plasma increased in a dose-dependent manner, while elimination half-life remained constant (11.2-13.2 h) irrespective of dose. Food intake decreased Cmax and AUC by 71% and 68%, respectively, at a dose of 250 mg. With respect to multiple-dose administration before meals, there were no significant differences in the pharmacokinetic parameters between the first and last days, indicating a lack of significant accumulation of MK-0591 in plasma. Urinary recovery as the unchanged form was negligible throughout the study. 3. Ionophore-stimulated production of leukotriene B4 (LTB4) in blood ex vivo was inhibited significantly from 1 h until 12 to 48 h after single-dose administration as compared with predose value. In parallel, the urinary excretion of endogenous leukotriene E4 (LTE4) was significantly decreased from 4 to 8 h until 48 to 72 h after drug administration. Reduction of ionophore-stimulated LTB4 biosynthesis and urinary excretion of LTE4 following single administration of MK-0591 was statistically significant as compared with placebo group, and the duration of inhibition of LTB4 biosynthesis was dose-related.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin AT1 receptor-mediated attenuation of cardiac hypertrophy due to volume overload: involvement of endothelin

The role of angiotensin II via the angiotensin type 1 (AT1) receptor in the development of volume overload cardiac hypertrophy was investigated in adult male Wistar rats with aortic insufficiency. We examined the effects of specific angiotensin AT1 receptor blockade with losartan (2-n-butyl-chloro-5-hydroxymethyl-1-[(2'-(1H-tetrazol-5-yl) biphenyl-4-yl)methyl]-imidazole potassium) on left ventricular weight and left ventricular angiotensin II and endothelin-1 level to test the possibility that the cardiac action of angiotensin II may be mediated by endogenous endothelin-1. Moreover, to verify the possible involvement of endothelin-1, we measured left ventricular endothelin-1 levels during the hypertrophic process and evaluated the effect of the endothelin ETA receptor specific antagonist, FR139317 ((R)2-[(R)2-[(S)-2-[[1-(hexahydro-1H-azepinyl)]carbonly] amino-4-methylpentanoyl]amino-3-[3-(1-methyl-1H-indolyl) propionyl]amino-3-(2-pyridyl) propionic acid), on left ventricular weight. Two weeks after production of aortic insufficiency, left ventricular weight and left ventricular endothelin-1 concentration were markedly elevated in the rats with aortic insufficiency as compared with the sham-operated control rats, but left ventricular angiotensin II was not changed. Losartan (10 mg/kg/day p.o., 2 weeks) significantly reduced left ventricular weight and left ventricular endothelin-1 level in the rats with aortic insufficiency without affecting blood pressure and there was a significant positive correlation between left ventricular weight and left ventricular endothelin-1 content. Left ventricular endothelin-1 content correlatively increased to left ventricular weight during the development of the left ventricular hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

The axial distribution of nicotine content along hair shaft as an indicator of changes in smoking behaviour: evaluation in a smoking-cessation programme with or without the aid of nicotine chewing gum

1. Hair samples were obtained from subjects at the end of a 6 month smoking-cessation programme carried out with (n = 16) or without (n = 10) the aid of nicotine chewing gum. The axial distribution of nicotine along the hair shaft was determined and compared both with the self-report of smoking behavior and with the concentration of carbon monoxide (CO) in expired air measured at 1 month intervals. 2. A gradual decrease in nicotine content along the hair shaft corresponded to the decrease in self-reported number of cigarettes smoked daily in both the nicotine chewing-gum treated and untreated subjects and with the clinical assessment of abstinence. 3. There was reasonable agreement between the CO content of expired air, the self-reported number of cigarettes smoked daily and the axial distribution of nicotine in 22 of 26 subjects. In the other four subjects there was an apparent disagreement between the CO content of expired air and the other parameters. 4. This study showed that, as a routine marker of smoking status, hair analysis may be preferable to repeated CO measurements since only a single sample at the end of an abstinence programme might be sufficient. However, one problem is that nicotine may dissociate slowly from melanin to limit the ability to mark a sudden cessation of smoking. Also, some nicotine in hair might be attributable to nicotine adsorbed to the outside of hair.

Effects of losartan, an angiotensin II antagonist, on the development of cardiac hypertrophy due to volume overload

To investigate the contribution of a cardiac renin-angiotensin system to cardiac hypertrophy due to volume overload, the effects of losartan, a non-peptide angiotensin (Ang) II type 1 (AT1) receptor antagonist on left ventricular hypertrophy (LVH) was studied. LVH was produced in male Wistar rats by volume overload secondary to aortic insufficiency (AI). Losartan (10 mg/kg/d) was orally administered for 2 weeks after surgery to both AI and sham-operated (control) rats. Two weeks after surgery, aortic pulse pressure and left ventricular (LV) weight were markedly increased in the AI rats as compared with the control group, whereas cardiac angiotensin converting enzyme (ACE) activity remained unchanged. The effects of the chronic administration of losartan an AT1 receptors were verified by the blockade of Ang II pressor response. Losartan treatment produced a significant reduction in LVH in AI rats without affecting the systolic blood pressure. In separate groups of rats, to elucidate the mechanisms of the attenuation of LVH by treatment with losartan, we determined plasma and LV immunoreactive Ang II content and plasma renin activity (PRA). LV Ang II content increased in AI rats, while plasma Ang II content, PRA and II concentration were increased by the treatment. There was a significant positive correlation between LV weight and LV Ang II content. These results suggest that cardiac Ang II, rather than circulating Ang II, plays an important role in the LVH due to volume overload via the AT1 receptor.

Temporal profile of nuclear DNA fragmentation in situ in gerbil hippocampus following transient forebrain ischemia

To determine the time course of nuclear DNA damage in the gerbil hippocampus following transient ischemia, brain sections 48, 72, 96 h and 7 days following 5 min ischemia were evaluated by a specific in situ labeling method of DNA breaks. After 72 h, only the neurons located in the medial part of the CA1 sector were labeled. And then, DNA damage extended to the lateral part of the sector with time.

Time course of appearance of ofloxacin in human scalp hair after oral administration

The time course of appearance of antimicrobial ofloxacin (OFLX) in human scalp hair was monitored in three healthy male volunteers after the oral administration of 100 mg OFLX three times daily for 2 consecutive days. Hair samples were collected from each subject by plucking several strands of frontal hair every day from 1 till 16 days after administration. A single hair was dissolved in 1 M NaOH to extract OFLX by chloroform, and the drug was measured by high-performance liquid chromatography and fluorescence detection. OFLX started to appear in the hair 1 to 3 days after administration and reached the maximal level approximately 4 to 9 days, remaining at almost the same level thereafter. This finding suggests the slow transfer of OFLX from hair follicle cells to hair matrix may be due to the slow dissociation of OFLX from bound melanin.

Pharmacokinetics and tolerance of DU-6859a, a new fluoroquinolone, after single and multiple oral doses in healthy volunteers

The pharmacokinetics and tolerance of DU-6859a, 7-[(7S)-7-amino-5-azaspiro[2,4]heptan-5-yl]-8-chloro-6-fluor o-1-[(1R, 2S)-2-fluoro-1-cyclopropyl]-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid sesquihydrate, were investigated in healthy male Japanese volunteers after single (25, 50, 100, and 200 mg) and multiple (100 mg three times a day for 6 days plus once a day on the 7th day and 50 mg every 12 h for 13 doses) oral doses. DU-6859a was well tolerated at all doses, and all 36 subjects completed the study; mild transient soft stool in five volunteers and mild transient diarrhea in one volunteer on the multiple-dose (100 mg three times a day) study were the only side effects reported. No drug crystals were observed in the urine after the single 200-mg dose and the 100-mg three times a day regimen. DU-6859a was rapidly absorbed in the fasted state. The mean maximum concentration in serum (Cmax) ranged from 0.29 to 1.86 micrograms/ml for the 25- to 200-mg dose, and the mean time to reach Cmax ranged from 1.0 to 1.3 h. The terminal half-life ranged from 4.4 to 5.0 h. The area under the curve increased dose dependently. The serum protein binding of the drug was approximately 50%. The apparent volume of distribution clearly exceeded 1 liter/kg, suggesting good tissue penetration. Within 48 h, the cumulative urinary recovery of unchanged drug amounted to 69 to 74% of the dose administered, while fecal excretion up to 48 h after the 200-mg dose accounted for ca. 3% of the dose. Food intake did not affect the rate and extend of absorption of DU-6859a to a clinically significant extent. During multiple oral dosing, the accumulation of the drug in serum was close to the theoretically predicted values, which indicated that there was virtually no drug accumulation.

An experimental myocardial infarction model in the rat and its properties

The photochemical reaction between rose bengal and light (540 nm) produces thrombotic occlusion in rat coronary artery. We have now developed an experimental myocardial infarction (MI) model by photochemically induced thrombosis (PIT) in rats and investigated the mechanisms responsible for the induction of MI. PIT in the coronary artery induced myocardial ischemia, which was determined by tissue oxygen tension (tpO2), and resulted in MI. Pretreatment with a thromboxane (TX) A2-receptor antagonist, vapiprost, prevented a decrease in myocardial tpO2 and markedly reduced the MI area, although vapiprost inhibited collagen-induced platelet aggregation by 30% ex vivo. An ADP-induced platelet aggregation inhibitor, clopidogrel, also reduced the MI area. In contrast to vapiprost, clopidogrel inhibited collagen-induced platelet aggregation by 90% ex vivo. Pretreatment with a 5-HT2-receptor antagonist, ketanserin, which did not inhibit collagen-induced platelet aggregation ex vivo, prevented the decrease in myocardial tpO2 and reduced the MI area. These results suggest that TXA2, 5-HT and ADP play a role in the induction of MI and that platelet aggregation and other factors induce ischemia in this model.

Pharmacokinetics and safety of intravenous recombinant human superoxide dismutase (NK341) in healthy subjects

Recombinant human superoxide dismutase (rhSOD), NK341, was intravenously administered to healthy male volunteers at doses of 1750-35000 U/kg, and the safety and pharmacokinetic properties were evaluated. There were no abnormal findings attributable to the test drug throughout the study, showing that NK341 was well tolerated in healthy subjects. Tri-exponential elimination of the drug from blood was observed with half-lives of about 20 minutes (alpha phase), 80 minutes (beta phase), and 6 hours (gamma phase). The values of the maximal plasma concentration and the areas under the plasma concentration curves linearly increased with the doses given. On the other hand, the urinary recovery of the drug also increased with the dose, ranging approximately from 3%-45% of the dose. The plasma concentration of the drug measured by an enzyme immunoassay was quite comparable to SOD activity measured by electron spin resonance, suggesting that NK341 was present in blood as the active form of SOD.

Phase I study of E1077, a novel parenteral cephem antibiotic

The safety and pharmacokinetics of E1077, a new injectable cephem antibiotic, were evaluated in healthy male adult volunteers. In the single-dose studies, 100, 250, 500, 1,000, and 2,000 mg of E1077 were administered by intravenous infusion at a constant rate for 60 minutes, then 1,000 mg of the drug by intravenous infusion at a constant rate for 5 minutes. The Cmax were 6.4, 15.7 +/- 12.0, 34.7 +/- 4.6, 63.2 +/- 4.6, 142.7 +/- 5.6, and 131.6 +/- 36.0 (means +/- SD) micrograms/mL, respectively, and the Cmax and AUC increased linearly with the dose. Plasma concentration-time curves were well described by a two-compartment open model. The plasma elimination half life of the drug was 1.88 +/- 0.15 hours. The mean urinary recovery within the first 24 hours was 94.1 +/- 5.1% of the dose. In the multiple-dose study, 2,000 mg of E1077 was intravenously administered at a constant rate over 60 minutes every 12 hours for 4.5 days (a total of nine times). The Cmax after the first and ninth doses were 134.0 +/- 17.4 and 135.5 +/- 15.5 micrograms/mL, respectively, and trough levels in day 1 and day 5 (at 12 hours after the first and ninth administration, respectively) were 2.2 +/- 0.8 and 1.9 +/- 0.4 micrograms/mL, respectively. No accumulation of the drug in plasma was observed. There were no significant differences in plasma levels or in the urinary recoveries between the single- and multiple-dose regimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of bleomycin resistance in a human oral squamous carcinoma cell line and characterisation of bleomycin-resistant and -sensitive clones

We examined the change of sensitivity to antitumour agents by repeated treatment with bleomycin (BLM) using two oral squamous carcinoma cell lines, SCCTF and SCCKN. SCCTF exhibited minimal sensitivity to BLM and strong heterogeneity in BLM sensitivity, whereas SCCKN was highly sensitive to BLM and showed weak heterogeneity. When SCCTF was treated continuously with low-dose BLM (0.1 microgram/ml) but not intermittently with high-dose BLM (1 microgram/ml), the BLM sensitivity was rapidly decreased to acquire drug resistance. On the other hand, SCCKN was completely killed by the same treatments. To investigate the mechanism of induction of resistance in SCCTF, BLM-sensitive and -resistant clones, TF-S and TF-R, were isolated and analysed. Consequently, TF-R showed decreased cellular accumulation and retention of BLM, increased BLM hydrolase activity and elevated DNA repair activity concomitant with increased poly(ADP-ribose) polymerase activity as compared with TF-S. Therefore, it was suggested that antitumour drug-resistant clones were selectively grown from heterogeneous tumour cell population.

Enhancement of thrombolytic efficacy of tissue-type plasminogen activator by adjuvants in the guinea pig thrombosis model

Reocclusion following thrombolysis is a major limitation of thrombolytic therapy with recombinant tissue-type plasminogen activator (rt-PA). We investigated the effects of vapiprost ((1R-(1 alpha(Z),2 beta,3 beta,5 alpha))-7-(5-((1,1'-biphenyl)-4-yl-methoxy)- 3-hydroxy-2-(1-piperidinyl)cyclopentyl)-4-heptenoic acid, a thromboxane A2 receptor antagonist); argatroban ((2R,4R)-4-methyl-1-[N2-(3-methyl-1,2,3,4-tetrahydro-8-quinolinyl)sulfon yl] - L-arginyl)]-2-piperidine-carboxylic acid, a specific thrombin inhibitor) and MK-886 (3-[1-(4-chlorobenzyl)-3-t-butyl-thio-5-isopropylindol-2-yl]-2,2- dimethylpropanoic acid, a specific leukotriene biosynthesis inhibitor) on the thrombolytic efficacy of rt-PA. The guinea pig femoral artery was thrombotically occluded by photochemical reaction between rose bengal and green light. Thirty min after the occlusion, rt-PA was administered and the time (T1) for reopening of the vessel and the frequency of reocclusion (Fro) 24 h after thrombolysis were monitored. With rt-PA alone, T1 was 28 +/- 7 min (n = 10) and Fro was 70%. T1 was reduced to 9 and 20 min by a combination of rt-PA with vapiprost and argatroban respectively. Fro was reduced by all three adjuvants. Histological observations revealed extensive adherence of polymorphonuclear leucocytes to the damaged endothelium at the site of thrombolysis. It is concluded that thromboxane A2, thrombin and leucocytes are involved in reocclusion after thrombolysis.

Pharmacokinetic properties of a novel gastric proton pump inhibitor, (+/-)-2-[(4-methoxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9- yl)sulfinyl]-1H-benzimidazole sodium salt, in healthy subjects

The pharmacokinetics and safety of TY-11345 [(+/-)-2-[(4-methoxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9- yl)sulfinyl]-1H-benzimidazole sodium salt], a novel gastric proton pump inhibitor, were studied in healthy male volunteers after single (20, 40, and 80 mg) and repeated oral doses (60 mg, once daily for 7 days) as enteric-coated tablet. At the single doses of 20 and 40 mg, intragastric pH was continuously monitored in each of two subjects. No abnormal findings definitely attributable to the test drug were observed throughout the study. In the single-dose study, the maximum plasma concentration (Cmax) and area under the plasma concentration-time curve of TY-11345 increased in a dose-proportional manner. The time to reach Cmax was about 3 h after dosing and plasma concentrations declined thereafter with a half-life of about 1 h irrespective of dose. The effect of food intake on the pharmacokinetic parameters of TY-11345, which was evaluated at the dose of 40 mg in a cross-over design, was not significant. TY-11345 was not detected in urine unchanged, while a main metabolite and its conjugate were identified in urine as 32-38% of the dose. An intragastric pH value over 4 was obtained about 3 h after the administration of 40 mg and maintained for more than 5 h, despite the fall of plasma concentration. This effect was less obvious at a dose of 20 mg. In the multiple-dose study, the pharmacokinetics exhibited no substantial difference between the first and last doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Early evaluation of necrotizing fasciitis with use of CT

Gas bubbles are one of the important signs in the clinical diagnosis of necrotizing fasciitis, and radiographs are mandatory. An instance where gas bubbles not found on the plain radiographs were clearly shown by CT, which is a useful method for close monitoring and decompression of gas bubbles situated deeply in the spaces of the maxillo-facial and neck regions.

Analysis of a new fluoroquinolone derivative (Q-35) in human scalp hair as an index of drug exposure and as a time marker in hair

Scalp hair samples were obtained every month for three months after administration from healthy male volunteers who participated in the phase I study of a new antimicrobial fluoroquinolone derivative (Q-35). Hairs were cut into 1 cm long pieces successively from the scalp end. Corresponding pieces of 5 hair strands were dissolved in 1 M NaOH and assessed for Q-35 by HPLC. The drug was detectable in the hairs of all subjects taking either a single (400 mg, n = 6) or repeated oral doses of Q-35 (400 mg/day for 6.5 days, total 2600 mg, n = 6). The hair portions containing the drug were shown in most subjects to move outwards along the hair shafts month by month in proportion to the hair growth rate of about 1 cm/month. Q-35 (600 mg/day) was also given to 6 healthy male volunteers for 6.5 days (total 3900 mg) and hair samples were obtained 1 and 3 months after administration. When Q-35 was analyzed along a single hair shaft, the drug was detectable only in 1-2 consecutive 1 cm long pieces, which were also shown to move outwards along the hair shaft with time. A detailed analysis revealed that the drug was contained only in 2-4 consecutive 2.5 mm long pieces of a single hair collected after 3 months, showing that there was no significant axial diffusion of the drug along the hair shaft with time.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics and safety of NM441, a new quinolone, in healthy male volunteers

The safety and pharmacokinetics of NM441, a prodrug of a new thiazeto-quinoline carboxylic acid derivative, NM394, were evaluated in healthy male volunteers given the drug orally in single doses of 20, 50, 100, 200, and 400 mg, and multiple doses of 300 mg twice daily for 6.5 days. No remarkable abnormalities were observed in symptoms, physical tests, laboratory tests, electrocardiogram (ECG), electroencephalogram (EEG), or equilibrium test. The mean plasma concentrations of active metabolite NM394 peaked between 0.5 and 1.0 hours, and the maximum concentrations were 0.68, 1.09, and 1.88 micrograms/mL at doses of 100, 200, and 400 mg, respectively. The mean half-lives were 7.7 to 8.9 hours and were not affected by dose. The mean urinary excretion rates of NM394 were 46.0, 38.3, and 30.6% of the doses within 48 hours, respectively, and other metabolites were excreted in urine by 7% of the doses. The mean salivary concentrations of NM394 were approximately 20% of the plasma concentrations. The mean fecal excretion rates of NM394 and NM441 were 52.9 and 4.2%, respectively within 72 hours after dosing of 400 mg. The Cmax, AUC, and urinary excretion rates were not altered by food intake, whereas the Tmax was prolonged slightly. In the multiple-dose study, the steady state of plasma concentration of NM394 was achieved on day 3 or 4, and further accumulation did not occur thereafter. The mean urinary excretion rate of NM394 was 49.0% during and 48 hours after the multiple administration. The acceptable safety and tolerance and defined pharmacokinetic characteristics of NM441 support further testing.