Chromosome evolution in the lizard genus Gekko (Gekkonidae, Squamata, Reptilia) in the East Asian islands.

The lizard genus Gekko consists of over 30 species distributed in Asia and Oceania. From the insular region of East Asia including Japan and Taiwan, 9 species (G. hokouensis, G. japonicus, G. shibatai, G. tawaensis, G. vertebralis,G. yakuensis, and 3 undescribed species) are currently recognized. We made karyological analyses for all these species. Their karyotypes invariably consisted of 2N = 38 chromosomes, but exhibited considerable variation in fundamental number (ranging from 56-62). Substantial chromosomal variation was detected even among populations of a morphologically relatively uniform species, G. hokouensis. Populations of G. hokouensis from the central and northern Ryukyus exhibited prominent female heteromorphic (i.e., ZW type) sex chromosomes. Populations of the southern Ryukyus exclusive of Yonagunijima also had ZW sex chromosomes, whose heteromorphisms were, however, much less prominent. The other G. hokouensis populations including the topotypic continental representatives and the population from Yonagunijima of the southern Ryukyus exhibited no sex chromosome heteromorphism at all. These results strongly suggest that G. hokouensis in the current taxonomic definition actually includes more than 2 species. The process of chromosomal evolution in the East Asian Gekko is hypothesized.

Coronary risk factors in Kawasaki disease treated with additional gammaglobulin.

AIMS: To assess the hypothesis that an additional intravenous gammaglobulin (IVGG) infusion, if administered early, may prevent coronary artery lesions (CAL) in patients with Kawasaki disease (KD) who do not respond to initial IVGG therapy. METHODS: Forty four KD patients (17 with CAL and 27 without CAL), treated with additional IVGG because of persistent or recrudescent fever after initial IVGG therapy, were studied. Main outcome measures were the presence of CAL by echocardiography and the number of febrile days before and after start of additional IVGG infusion (pre- and post-additional IVGG). RESULTS: In univariate analyses, risk factors for CAL were the number of febrile days pre-additional IVGG, the number of febrile days post-additional IVGG, the number of days that initial IVGG was divided over, the white blood cell count pre- and post-additional IVGG, and the C reactive protein concentration pre-additional IVGG. In a multivariate analysis, the only independent risk factor was the number of febrile days pre-additional IVGG (> or =10 days; odds ratio 7.86; 95% CI 1.44 to 42.8; p = 0.02). CONCLUSIONS: Among KD patients with persistent or recrudescent fever after initial IVGG therapy, administration of additional IVGG before the first 10 febrile days was associated with a decreased prevalence of CAL, when compared with the prevalence in those who were retreated later. An additional IVGG infusion, if administered early, may prevent CAL in initial IVGG non-responders.

[Clinical and bacteriological studies on panipenem/betamipron in pediatrics. Kanagawa Research Group for Infectious Diseases of Children].

Following its introduction into the market, PAPM/BP (panipenem/betamipron) was clinically studied in 188 evaluable cases out of 207 cases primarily of respiratory infectious diseases treated at the pediatric departments of 15 hospitals. In the clinical evaluation, the drug proved effective in three of three cases of sepsis; three of three cases of suppurative meningitis; nine of ten cases of laryngopharyngitis, six of seven cases of tonsillitis, 56 of 63 cases of acute bronchitis, 90 of 98 cases of pneumonia, and one of one case of phyothorax, all of which are respiratory infectious diseases; one of one case of secondary infection of a chronic respiratory disease; and two of two cases of lymphadenitis, which is a disease of the soft dermal structure. The overall efficacy rate was 91.0% (171/188 cases). In the bacteriological study, Gram-positive bacteria were eliminated in five of five strains of S. aureus, 30 of 31 strains of S. pneumoniae (96.8%), and three of three strains of S. pyogenes. Gramnegative bacteria were eliminated in 15 of 17 strains of H. influenzae (88.2%), three of four strains of M. catarrhalis, and two of two strains of K. pneumoniae. The overall elimination rate was 92.1% (70/76 strains). In the 23 strains of S. pneumoniae that were examined, penicillin-resistant strains accounted for 56.5%, showing an elimination rate of 100%. No serious adverse effects were observed, and the incidence of adverse effects was 1.45%. As for abnormalities in laboratory tests, levels of GOT and GPT increased in eight cases (3.88%), LDH increased in one case (0.48%), and neutropenia occurred in one case (0.51%). These results suggest that PAMP/BP could be considered the first choice in the treatment of infectious diseases in pediatrics, due to its effectiveness and high level of safety.

The pathogenic role of Staphylococcus epidermidis capsular polysaccharide/adhesin in a low-inoculum rabbit model of prosthetic valve endocarditis.

BACKGROUND: The capsular polysaccharide/adhesin (PS/A) antigen of Staphylococcus epidermidis was required to produce endocarditis in a rabbit model in which infection resulted from hematogenous spread of bacteria from a contaminated catheter in the jugular vein. However, many prosthetic valve endocarditis (PVE) infections probably result from direct contamination of the valve with small numbers of bacteria during surgery. The role of PS/A in this situation was evaluated by modifying a rabbit model of endocarditis to partially mimic PVE. METHODS AND RESULTS: A Teflon catheter was contaminated with graded inocula of either PS/A-positive S epidermidis strain M187sp11 or the PS/A-negative, isogenic strain M187sn3 and inserted into the left ventricle through the aortic valve. The PS/A-positive strain had a 50% infectious dose of 1.1 x 10(2) cfu (95% CI, 3.3 to 3.7 x 10(3)) compared with 8.5 x 10(4) cfu of the PS/A-negative strain (95% CI, 8.6 x 10(3) to 8.5 x 10(5)). The odds for developing endocarditis were estimated to be 42 times higher for any given inoculum level of the PS/A-positive strain (P = .1). When the PS/A-positive strain was adherent to a catheter surface it survived in rabbit blood, whereas under the same conditions the PS/A-negative strain was killed approximately 90% in 1 hour. CONCLUSIONS: Direct contamination of an intraventricular foreign body by low levels of PS/A-positive S epidermidis results in endocarditis in rabbits, but at suitably high doses PS/A-negative strains have sufficient virulence to infect cardiac vegetations. PS/A enhances but is not absolutely required for bacterial virulence in a rabbit model of PVE.

Potentiation of Staphylococcus epidermidis catheter-related bacteremia by lipid infusions.

Lipid infusions given to low-birth-weight neonates are associated with coagulase-negative staphylococcal bacteremia. A rabbit model of catheter-related Staphylococcus epidermidis bacteremia was used to compare infection rates between animals receiving 20% lipid infusions with those receiving 10% glucose infusions. Bacterial growth was detected in 43 (66%) of 65 blood cultures obtained during lipid infusions but only 6 (7%) of 91 blood cultures obtained during glucose infusions (P < .001). S. epidermidis was cultured from 7 of 9 catheters recovered from lipid-infused rabbits but from only 3 of 13 catheters from glucose-infused rabbits (P = .016). Lipid but not glucose solutions containing low levels of protein (0.1%-1.0%) supported the survival and growth of S. epidermidis. These results suggest that lipids contribute to the survival and growth of S. epidermidis on contaminated catheters, enhancing the potential of these organisms to disseminate and cause bacteremia.

Transposon mutants of Staphylococcus epidermidis deficient in elaboration of capsular polysaccharide/adhesin and slime are avirulent in a rabbit model of endocarditis.

Virulence comparisons were made in a rabbit model of endocarditis between wild-type and transposon mutants of Staphylococcus epidermidis deficient in elaboration of the capsular polysaccharide/adhesin (PS/A) and slime. The parental phenotype grew from 36 (61%) of 59 cultures of blood. The PS/A-negative phenotype grew in 1 (1%) of 98 cultures of blood (P < .001). No animals infected with PS/A-negative strains developed endocarditis compared with 75% of rabbits infected with PS/A-positive strains. PS/A-producing strains survived better than did PS/A-deficient strains in intact, absorbed rabbit or human serum plus human leukocytes. There was also greater deposition of C3 onto the PS/A-deficient strains than with the PS/A-producing isogenic strains. PS/A functions as an antiphagocytic bacterial capsule preventing C3 deposition and phagocytosis; loss of this structure increases the strain's susceptibility to opsonic killing and decreases its virulence.

Endemic nosocomial transmission of Staphylococcus epidermidis bacteremia isolates in a neonatal intensive care unit over 10 years.

To assess long-term nosocomial transmission, trends in antibiotic resistance, and expression of potential virulence factors, 86 randomly selected Staphylococcus epidermidis bloodstream isolates obtained from 80 patients in a neonatal intensive care unit (NICU) over a 10-year period were studied. Pulsed-field gel electrophoresis (PFGE) analysis of SmaI-digested whole chromosomal DNA revealed distinctive banding patterns that persisted in the NICU over long periods. Pattern A included 22 isolates (26%) obtained during 1983-1990, and pattern B included 24 isolates (28%) from 1983 to 1991. All 10 isolates examined in 1984 fell into one of these two patterns. Isolates with either pattern expressed polysaccharide/adhesin (PSA) and slime; 90% and 87% were resistant to oxacillin and gentamicin, respectively, with no trends over time. These findings suggest that distinct clones of S. epidermidis can become endemic in NICUs over periods as long as a decade and that nosocomial transmission plays an important role in neonatal S. epidermidis bacteremia.

Occurrence of capsular polysaccharide/adhesin among clinical isolates of coagulase-negative staphylococci.

Clinical isolates of coagulase-negative staphylococci were analyzed for elaboration of the capsular polysaccharide/adhesion (PS/A) and extracellular biofilm or slime. Of the 151 analyzed, 103 (68%) produced PS/A and 69 (46%) made extracellular slime; 87% of the slime-producing isolates made PS/A. Among isolates from all clinical infections examined except peritonitis, PS/A-positive isolates bound significantly (P < .001) more colony-forming units after 15 min to 1.5-cm segments of silicone-elastomer catheter than did PS/A-negative isolates. Slime-positive isolates were not more adherent than slime-negative isolates, because 42% of the PS/A-positive isolates were slime-negative. Thus, PS/A expression is common among clinical isolates of coagulase-negative staphylococci, accounting for most slime-positive and a proportion of slime-negative isolates.

[Pharmacokinetics and clinical efficacy of flomoxef in neonates].

Clinical pharmacology and efficacy of flomoxef (FMOX) in neonates were investigated. And the following results were obtained. 1. Mean serum concentrations of FMOX at 30 minutes after administration were 24.3 micrograms/ml, 47.6 micrograms/ml, and 85.8 micrograms/ml at doses of 10 mg/kg, 20 mg/kg, and 40 mg/kg administered, respectively. 2. Mean serum half-lives of FMOX were 3.4 hours in 0-3 day-old neonates, and 2.6 hours in 4 day-old or older subjects. 3. A dose response was evident among different dose groups given 10 mg/kg, 20 mg/kg, and 40 mg/kg. 4. Urinary recovery rates of FMOX in the first 6 hours after administration ranged between 12.8 and 51.1%. 5. FMOX was effective in 7 out of 8 cases in which causative pathogens were identified. 6. Diarrhea was observed in 1 case as a side effect of the drug, but the symptom was relieved soon after the completion of the treatment. There was no case in which any abnormal laboratory results were observed. 7. FMOX has a broad spectrum of activities against Gram-positive and Gram-negative aerobes and anaerobes. It is stable against most of beta-lactamases. It was demonstrated to be highly effective in our study, and yet without any serious side effects. FMOX is therefore considered to be one of the useful agents of the first choice for the treatment of bacterial infections such as sepsis and urinary tract infections in neonates and infants.

[Pharmacokinetics and clinical safety of aztreonam in neonates].

Clinical pharmacology and safety of aztreonam (AZT) in the neonatal period were investigated. The results obtained are summarized as follows. 1. Serum concentrations of AZT at 30 minutes after administration of 10 mg/kg were 22.1-32.2 micrograms/ml and those of 20 mg/kg 22.5-75.9 micrograms/ml. 2. Serum half-lives of AZT were 3.5-6.6 hours in 0-3 day-old neonates, and 2.0-4.0 hours in neonates 4 day-old or older. 3. A dose response was evident between the 10 mg/kg administration group and the 20 mg/kg group. 4. Urinary recovery rates of AZT in the first 6 hours after administration ranged between 17.8 and 69.9%. 5. No clinical side effects were observed in the administration of AZT alone (6 cases), or in combination with ampicillin (9 cases). Thrombocytosis was observed in 1 case as an abnormal laboratory finding, but it returned to normal within 1 week after the completion of AZT administration. 6. AZT had a potent antimicrobial activity against Gram-negative aerobes and hardly induced beta-lactamase. Furthermore, side effects were not observed in this study. Therefore, AZT is considered to be useful for the treatment of urinary tract infections and other serious infections caused by Gram-negative pathogens even in the neonatal period.

[Pharmacokinetics and clinical studies on cefsulodin in neonates].

Pharmacokinetics and clinical studies on cefsulodin (CFS) were conducted in neonates. 1. MIC's of CFS, sulbenicillin and gentamicin (GM) were determined using 7 strains of Pseudomonas aeruginosa clinically isolated from neonates and maintained as stock cultures. CFS was found to be nearly as active as GM. 2. When CFS 20 mg/kg was administered to a 12-day-old neonate by intravenous bolus injection, serum concentrations were 8.7 micrograms/ml before administration and 51.7 micrograms/ml at 30 minutes, 44.4 micrograms/ml at 1 hour, 38.6 micrograms/ml at 2 hours and 11.1 micrograms/ml at 6 hours after administration. The half-life was 2.5 hours. 3. CFS was administered alone or combination with other drugs to 3 neonates. The drug was clinically effective in 2 cases and slightly effective in another. Bacteriologically, one case was rated as decreased, another as replaced, and the remaining one as unchanged. 4. Neither side effects nor abnormal laboratory values attributable to CFS were found.

[Pharmacokinetic and clinical studies on cefmenoxime in neonates and premature infants].

Pharmacokinetic and clinical studies on cefmenoxime (CMX) in neonates and premature infants were conducted. The results are summarized as follows. 1. Intravenous administration of CMX at 20 mg/kg, via bolus injection or 1-hour drip infusion, produced at sufficiently high blood concentration. As it is the case with other cephem antibiotics, the half-life varied with age and tended to become shorter with aging. 2. There were intergroup differences in urinary recovery of the drug, but urinary concentrations were generally high. 3. In the clinical evaluation, 12 out of 15 cases which were evaluable for efficacy were rated "excellent" or "good". 4. Side effects were evaluated in 27 cases. A bleeding tendency was found in 1 case, eosinophilia in 1 case, elevated GOT in 1 case, and positive PIVKA II in 4 cases. It is, therefore, concluded that CMX is a highly useful drug for the treatment of bacterial infections in neonates and premature infants.

[Pharmacokinetics and clinical efficacy of imipenem/cilastatin sodium in neonates].

Clinical pharmacology and clinical efficacy and safety of imipenem/cilastatin sodium (IPM/CS), a beta-lactam antibiotic with a carbapenem nucleus and a dehydropeptidase-I inhibitor, were investigated in newborns. 1. Peak serum concentrations of IPM/CS at a dose of 20 mg/20 mg/kg were achieved at the end of 60-minute infusion. Maximum serum levels of IPM and CS were 44.2 micrograms/ml and 70.0 micrograms/ml, respectively, in neonates with ages 0-3 days. IPM and CS peak levels in premature infants with ages 0-3 days were 47.2 micrograms/ml and 56.1 micrograms/ml, respectively. IPM and CS peak levels in neonates 4 day-old or older were 35.0 micrograms/ml and 41.5 micrograms/ml, respectively, and in premature infants of similar ages were 45.7 micrograms/ml and 65.3 micrograms/ml, respectively. 2. Mean serum half-lives of IPM and CS in 0-3 day-old neonates were 1.6 hours and 3.1 hours, respectively, and the mean serum half-lives in premature infants were 2.1 hours and 4.6 hours, respectively. In neonates 4 day-old or older, the mean serum half-lives of IPM and CS were 1.6 hours and 2.6 hours, respectively, and in premature infants they were 1.5 hours and 1.9 hours, respectively. 3. A dose response was evident between doses of 10 mg/10 mg/kg and 20 mg/20 mg/kg of IPM and CS. 4. Urinary recovery rates of IPM for the 0- to 6-hour post IPM/CS infusion period ranged between 27.2 and 46.6%. For CS, urinary recovery rates for the 0- to 6-hour post IPM/CS infusion period ranged between 25.3 and 100.8%. 5. Clinical efficacy was evaluated in 9 patients and 7 patients showed excellent or good responses. 6. Of 14 patients who received IPM/CS treatment, 1 patient showed hematuria, leukopenia and thrombocytopenia, and 3 patients showed eosinophilia. However, these adverse reactions improved after the completion of therapy. 7. IPM has excellent antimicrobial activity against aerobic and anaerobic Gram-positive and Gram-negative bacteria. In this study, coadministration of IPM and CS produced good clinical responses and no serious adverse reactions. It is hence concluded that IPM/CS sodium is very useful for the treatment of severe bacterial infections in neonates, especially in the presence of beta-lactamase resistant strains and in polymicrobial infections.

[Pharmacokinetic and clinical evaluations on ceftriaxone in neonates and premature infants].

Ceftriaxone (CTRX) was clinically evaluated and its pharmacokinetics studied in neonates and premature infants, and the results obtained are summarized as follows. 1. Average blood levels of CTRX after intravenous administration of 10 mg/kg in 3 neonates with birth weights of 2,500 g or more were 45.32 mcg/ml at 15 minutes, 28.91 mcg/ml at 1 hour, 15.76 mcg/ml at 6 hours, and 16.28 mcg/ml at 12 hours, and the half-life was 9.93 hours. The half-life in a newly born premature infant (less than 1 day) was 28.90 hours, and in a premature infant 6 days old it was 12.90 hours. 2. Average blood levels after intravenous administration of 20 mg/kg to 2 neonates aged 0 and 3 days with birth weights of 2,500 g or more, were 129.7 mcg/ml at 15 minutes, 60.94 mcg/ml at 1 hour, 32.04 mcg/ml at 6 hours, and 24.23 mcg/ml at 12 hours, and the half-life was 8.95 hours. The half-life in a newly born premature infant (less than 1 day) was 20.70 hours. 3. Urinary recovery rates of CTRX in 12 hours after intravenous administration of 10 or 20 mg/kg to 6 neonates aged 0 to 3 days (including premature infants) ranged from 13.8 to 50.6%. 4. Clinical efficacies of CTRX were excellent or good in 3 of 4 neonates including infants suspected of having infections (efficacy rate: 75%). 5. As a side effect, diarrhea was noted in 1 case.

[Comparative, controlled study on an ampicillin suppository (KS-R 1) with an oral form of ampicillin in urinary tract infections].

Subjects were in-patients with bacterial urinary tract infections, ranging in age 4 months to 11 years 4 months. As a rule, daily dose was either four 125 mg (in potency) suppositories or four 125 mg (in potency) oral form given at 6-hour intervals over a period of 5 days. The number of children subjected to this study was 105. These children were divided into 2 groups (suppository 54; oral form 51) with matched pretreatment background factors. Therapeutic effectiveness rates were 70.4% for the suppository and 66.7% for the oral form, and no significant difference was observed between the 2 groups. Rates of efficacy by severity, presence or absence of underlying and/or complication diseases, daily dose and causative microorganisms did not differ significantly between the 2 groups. There was no significant difference in time-courses of improvement of clinical signs and symptoms between the 2 groups. Eradication rates for causative microorganisms were 65.9% for the suppository and 62.5% for the oral form. Most frequently isolated causative microorganisms were Escherichia coli and Proteus mirabilis. No significant differences were recognized in the therapeutic effect and usefulness evaluated by physicians in charge. The frequency of side effects did not differ significantly between the suppository group (6 with diarrhea and 1 with anal pain: 12.1%) and the oral form group (5 with diarrhea, 1 with displeasure and 1 with vomiting: 12.7%). Abnormal laboratory findings appeared in 6 cases (2 with eosinophilia, 2 with increased GOT and 2 with increased GPT) in the suppository group and 7 cases (2 with eosinophilia, 2 with thrombocytosis, 2 with increased GOT and 1 with increased GPT) in the oral form group.

[Basic and clinical studies of cefotiam in neonates and premature infants].

The effect of cefotiam (CTM) on neonates and premature infants was examined in basic and clinical studies. Minimum inhibitory concentrations of CTM against 190 clinically isolated strains kept by this department were investigated. This drug was found to have a strong antibacterial effect against Escherichia coli, Klebsiella spp., Proteus mirabilis and Streptococcus agalactiae, Staphylococcus aureus and Staphylococcus epidermidis, although some strains were resistant. The CTM was given to 0-3, 4-7, and greater than or equal to 8 day-old premature infants and neonates by intravenous injection at the dose of 20 mg/kg, and we studied changes in serum CTM levels over time. Mean serum CTM levels were 62.3 micrograms/ml at 15 minutes and 16.4 micrograms/ml at 6 hours after the injection, with the half-life of 3.6 hours, for the 0-3 day-old premature infants. They were 38.5 micrograms/ml at 15 minutes and 10.1 micrograms/ml at 6 hours, with the half-life of 2.9 hours, for the 0-3 day-old neonates. Those levels were 22.5 micrograms/ml at 15 minutes and 2.9 micrograms/ml at 6 hours, with the half-life of 1.9 hours, for the 4-7 day-old neonates, and 51.8 micrograms/ml at 15 minutes and 1.0 micrograms/ml at 6 hours, with the half-life of 1.1 hours, for the greater than or equal to 8 day-old neonates. The CTM was given to 0-3 and greater than or equal to 8 day-old premature infants and neonates by 1-hour intravenous drip infusion at the dose of 20 mg/kg, and changes in serum CTM levels after the infusion were followed. The 0-3 day-old premature infant (there was only one subject) had a peak serum CTM level of 21.0 micrograms/ml 1 hour after the start of the infusion (that is, at the time of its completion), with the level decreased to 8.6 micrograms/ml at 7 hours and the half-life was 5.4 hours. The mean peak serum CTM level in 0-3 day-old neonates were 36.7 micrograms/ml at 1 hour, which decreased to a mean of 7.0 micrograms/ml at 7 hours; the half-life was 2.3 hours.(ABSTRACT TRUNCATED AT 400 WORDS)

[Influence of cefroxadine dry syrup on intestinal bacterial flora].

Influence of cefroxadine (CXD) dry syrup on intestinal bacterial flora was studied in mice infected with 4 species of bacteria, namely, Escherichia coli, Enterococcus faecalis, Bacteroides fragilis and Bifidobacterium breve, and in pediatric patients having infections in the respiratory tract and cutaneous/soft tissues. The results were summarized as follows: CXD dry syrup was administered for 5 consecutive days to mice infected with the 4 species. No considerable changes were observed in levels of bacteria in the feces and in different parts of digestive tracts. Eleven pediatric patients were orally administered with 30-54 mg/kg of CXD dry syrup a day for 7-15 consecutive days. Symptom of diarrhea was noted in 2 patients. Dominant species of the intestinal flora such as E. coli, Bifidobacterium, and Bacteroides sometimes decreased in patients treated with CXD dry syrup. In general, however, decreases in numbers of these bacteria were insignificant. Changes of intestinal flora in patients treated with CXD dry syrup were apparently smaller than those treated with ampicillin and were similar to those treated with cephalexin or amoxicillin.

[Fundamental and clinical evaluation of ceftazidime in neonates and premature infants].

Fundamental and clinical evaluation of ceftazidime (CAZ) were carried out in neonates and premature infants, and the results obtained are summarized below. Serum concentrations of CAZ after administration of 20 mg/kg were satisfactorily high regardless of the route of administration; bolus intravenous injection or 1-hour intravenous drip infusion. Like other cephem antibiotics, half-lives tended to be shorter as day-ages of subject became higher. Although there were some differences in urinary recovery rates between different dosage groups, they were generally high. Clinical efficacy was either excellent or good in all 21 assessable cases. In 23 cases examined for adverse effects, diarrhea was observed in 1 case, and elevation of GOT and GPT, in another case.

[Fundamental and clinical studies on imipenem/cilastatin sodium in pediatrics].

Fundamental and clinical studies were carried out on imipenem/cilastatin sodium (MK-0787/MK-0791) in pediatric patients. The following results were obtained. A total of 238 clinical isolates stocked by our department was employed to determine the minimum inhibitory concentrations (MICs) of MK-0787 against various species of bacteria. The MK-0787 showed strong antibacterial activities against E. coli, Salmonella, Klebsiella, Proteus, Serratia, E. faecalis and S. epidermidis. Somewhat weaker activities were observed against P. aeruginosa and S. aureus. The MK-0787/MK-0791 was drip-infused intravenously into patients over a period of 1 hour, and serum levels of MK-0787 and MK-0791 were determined. At the dose level of 10 mg/10 mg/kg, the mean serum levels of MK-0787 and MK-0791 were 29.9 micrograms/ml and 18.1 micrograms/ml at 1 hour and 3.4 micrograms/ml and 1.3 micrograms/ml at 3 hours, respectively. The half-lives were 0.89 hour for MK-0787 and 0.99 hour for MK-0791. At the dose level of 20 mg/20 mg/kg, the mean serum levels of MK-0787 and MK-0791 were 46.3 micrograms/ml and 45.2 micrograms/ml at 1 hour and 5.5 micrograms/ml and 3.1 micrograms/ml at 3 hours, respectively. The half-lives were 0.97 hour for MK-0787 and 0.83 hour for MK-0791. At the dose level of 40 mg/40 mg/kg, the mean serum levels of MK-0787 and MK-0791 were 104.0 micrograms/ml and 80.9 micrograms/ml at 1 hour and 7.8 micrograms/ml and 5.9 micrograms/ml at 3 hours, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)