Fast Heating of Imploded Core with Counterbeam Configuration.

A tailored-pulse-imploded core with a diameter of 70 µm is flashed by counterirradiating 110 fs, 7 TW laser pulses. Photon emission (>40 eV) from the core exceeds the emission from the imploded core by 6 times, even though the heating pulse energies are only one seventh of the implosion energy. The coupling efficiency from the heating laser to the core using counterirradiation is 14% from the enhancement of photon emission. Neutrons are also produced by counterpropagating fast deuterons accelerated by the photon pressure of the heating pulses. A collisional two-dimensional particle-in-cell simulation reveals that the collisionless two counterpropagating fast-electron currents induce mega-Gauss magnetic filaments in the center of the core due to the Weibel instability. The counterpropagating fast-electron currents are absolutely unstable and independent of the core density and resistivity. Fast electrons with energy below a few MeV are trapped by these filaments in the core region, inducing an additional coupling. This might lead to the observed bright photon emissions.

Direct heating of a laser-imploded core by ultraintense laser-driven ions.

A novel direct core heating fusion process is introduced, in which a preimploded core is predominantly heated by energetic ions driven by LFEX, an extremely energetic ultrashort pulse laser. Consequently, we have observed the D(d,n)^{3}He-reacted neutrons (DD beam-fusion neutrons) with the yield of 5×10^{8} n/4π sr. Examination of the beam-fusion neutrons verified that the ions directly collide with the core plasma. While the hot electrons heat the whole core volume, the energetic ions deposit their energies locally in the core, forming hot spots for fuel ignition. As evidenced in the spectrum, the process simultaneously excited thermal neutrons with the yield of 6×10^{7} n/4π sr, raising the local core temperature from 0.8 to 1.8 keV. A one-dimensional hydrocode STAR 1D explains the shell implosion dynamics including the beam fusion and thermal fusion initiated by fast deuterons and carbon ions. A two-dimensional collisional particle-in-cell code predicts the core heating due to resistive processes driven by hot electrons, and also the generation of fast ions, which could be an additional heating source when they reach the core. Since the core density is limited to 2 g/cm^{3} in the current experiment, neither hot electrons nor fast ions can efficiently deposit their energy and the neutron yield remains low. In future work, we will achieve the higher core density (>10 g/cm^{3}); then hot electrons could contribute more to the core heating via drag heating. Together with hot electrons, the ion contribution to fast ignition is indispensable for realizing high-gain fusion. By virtue of its core heating and ignition, the proposed scheme can potentially achieve high gain fusion.

Performance of a rapid human metapneumovirus antigen test during an outbreak in a long-term care facility.

Using a newly developed rapid test, an outbreak of human metapneumovirus (HMPV) infection in a long-term care facility was detected within only 2 days after the onset of symptoms in a putative index case. The outbreak was almost under control within 8 days mainly by zoning patients, with the exception of two cases of HMPV that were diagnosed 16 and 17 days after the onset of the outbreak. According to an immunological diagnosis as well as the rapid test, it was eventually proven that 18 patients had HMPV infections. We suspected that even asymptomatic residents, who had not been completely separated from the facility population, were a source of infection. That suggested that all asymptomatic residents should be tested and that the separation of the infected patients should be absolute, if an outbreak of HMPV infection is suspected in such a facility.

Fusion using fast heating of a compactly imploded CD core.

A compact fast core heating experiment is described. A 4-J 0.4-ns output of a laser-diode-pumped high-repetition laser HAMA is divided into four beams, two of which counterilluminate double-deuterated polystyrene foils separated by 100 µm for implosion. The remaining two beams, compressed to 110 fs for fast heating, illuminate the same paths. Hot electrons produced by the heating pulses heat the imploded core, emitting x-ray radiations >20 eV and yielding some 10(3) thermal neutrons.

Negative effect of transforming growth factor-beta-1 on intestinal anastomotic tissue regeneration.

To examine the involvement of transforming growth factor-beta(1 )(TGF-beta(1)) in intestinal anastomotic repair, we administered a TGF-beta(1)-neutralizing antibody to rats after operation, and then examined its influence on the healing process and interaction with other peptide growth factors. Thirty male Sprague-Dawley rats were subjected to primary anastomosis after transection of the small intestine (n = 30) and treated by intraperitoneal administration of IgG (n = 15) or the TGF-beta(1) neutralizing antibody (n = 15). Treatment with the antibody against TGF-beta(1) resulted in more definite mucosal growth and increased vascularity on day 5 after surgery. Augmented mRNA expression of epidermal growth factor and vascular endothelial growth factor, and an increased number of cells that expressed these peptides in granulation tissue were demonstrated by RT-PCR and immunohistochemical staining. Taken together it was indicated that TGF-beta(1) has negative effects on regeneration of the bowel wall mucosa and angiogenesis in the course of intestinal anastomotic wound healing.

Molecular epidemiology of astroviruses in Japan from 1995 to 1998 by reverse transcription-polymerase chain reaction with serotype-specific primers (1 to 8).

In addition to the serotype-specific primers described previously (1 to 7), a new serotype 8-specific primer has been designed, allowing detection of all astrovirus serotypes. A total of 1,382 diarrheal stool samples in 5 regions in Japan were examined by reverse transcription-polymerase chain reaction (RT-PCR). The incidence of astrovirus infection in all 5 regions was 5.9% (82 of 1,382 samples) and infection occurred mainly from November to April. Serotypes 1, 3, and 4 were detected in 66, 14, and 2 of the 82 positive samples, respectively. None of the other serotypes was detected. The highest detection rate was from 0 to 1 year old, 39.0%, and the next highest was from 1 to 2 years old, 34.1%. The primers provide a useful approach for study of the epidemiology of astroviruses.

Serotypes of human rotaviruses in 7 regions of Japan from 1984 to 1997.

Human rotavirus (HRV) serotypes were studied from diarrheal stool specimens in children in 7 regions of Japan (Sapporo, Tokyo, Maizuru, Osaka, Kagawa, Kurume, and Saga) from 1984 to 1997 by enzyme immunoassay (EIA) with serotype-specific monoclonal antibodies against serotypes 1, 2, 3, and 4. In addition, reverse transcription-polymerase chain reaction (RT-PCR) was conducted for analysis of "others" which included nonserotypable and mixed-serotype rotavirus specimens by EIA. In 3756 rotavirus-positive specimens, serotype 1 was detected in 2649 (70.5%), serotype 2 in 362 (9.6%), serotype 3 in 232 (6.2%) and serotype 4 in 196 (5.2%). Overall, serotype 1 was predominant from 1984 to 1997, although there were a few cases in which serotype 2, 3 and 4 became predominant based on area and year. The frequency of serotype 1 has gradually increased since 1993. Twenty two, 2, 3 and 1 among 57 specimens of "others" by EIA from Tokyo, Maizuru, Sapporo and Kurume in 1995-1996 and 1996-1997 were determined as serotypes 1, 2, 3, and 9 by RT-PCR, respectively.

[Plasmodium falciparum infection in a 8-year old boy].

A 8-year old Japanese boy who returned from Tanzania was admitted to our hospital because of fever, vomiting, and headache. He was diagnosed as a Plasmodium falciparum infection verified by a blood smear. He was treated with quinine and halofantrine, and recovered completely. Malaria infection should be considered when patients return from Malaria endemic areas.

Nedaplatin and 5-FU combined with radiation in the treatment for esophageal cancer.

A series of patients with esophageal cancer was treated with chemotherapeutic regimens of the new antitumor platinum preparation nedaplatin plus 5-FU in combination with radiation therapy, and the therapeutic responses, side effects, and complications were clinically assessed. There were 2 patients with a complete response and 11 patients with a partial response, hence, a response rate of 76.5%. Major adverse reactions were those of hematological toxicity and included leukopenia (13 patients, 76.5%), thrombocytopenia (8 patients, 47.1%), and lowered serum hemoglobin concentration (9 patients, 52.9%). The leukopenia and thrombocytopenia, though of a grade 3 severity in 3 and 2 patients, respectively, subsided spontaneously in all affected cases. Gastrointestinal adverse reactions were mild and included appetite loss in 7 patients (41.2%) and nausea in 2 patients (11.8%). The only abnormality in renal function observed was a slight elevation of serum creatinine in one patient. The combined therapy of chemotherapy with nedaplatin and 5-FU plus radiation produced a high response rate in the treatment of carcinoma of the esophagus and was associated with reduced gastrointestinal and renal toxicity. The results indicate the combined therapy with nedaplatin to be clinically useful.

[Basic and clinical studies on tazobactam/piperacillin in pediatric field].

A drug susceptibility test of the combination drug TAZ/PIPC, which consists of a newly developed beta-lactamase inhibitor, tazobactam (TAZ), and one of penicillin antibiotics, piperacillin (PIPC), with combination ratio of 1:4 in potency, was conducted with stock strains and clinical isolates. The clinical efficacy and safety of its injection was also evaluated in children with a variety of infectious diseases. The results were as follows: 1. In susceptibility test, 114 strains from 4 species of stock strains were treated with 8 drugs, that is, TAZ/PIPC, PIPC, penicillin G (PCG), ampicillin (ABPC), cefotiam (CTM), cefotaxime (CTX), ceftazidime (CAZ), and sulbactam/cefoperazone (SBT/CPZ). Of three clinically isolated species from patients, Staphylococcus aureus (S. aureus) was treated with TAZ/PIPC, PIPC, methicillin (DMPPC), CTM, CTX, and SBT/CPZ, and the others were treated with the same drugs except for DMPPC. The MICs were measured for these bacterial strains inoculated at the concentration of 10(6) CFU/ml. The MIC90 values of TAZ/PIPC against 45 strains of Streptococcus pyogenes (S. pyogenes), one of the stock cultures of Gram-positive cocci, were 0.05 microgram/ml and similar to those of PIPC, CTM, CAZ, and SBT/CPZ. The MICs of TAZ/PIPC for 28 strains of Streptococcus agalactiae (S. agalactiae) were 0.39 microgram/ml and similar to those of PIPC, CTM, CAZ, and SBT/CPZ. As for Gram-negative bacilli, the MIC90 of TAZ/PIPC against 10 strains of Bordetella pertussis (B. pertussis) were 0.10 microgram/ml and similar to those of PIPC. The MIC90 of TAZ/PIPC against 31 strains of Haemophilus influenzae (H. influenzae) were 0.05 microgram/ml and similar to those of PIPC, CTX, and SBT/CPZ. Regarding Gram-positive cocci isolated from patients received this combination drug, the MIC90 of TAZ/PIPC against 2 strains of S. aureus, a non beta-lactamase producing strain and a low-beta-lactamase producing strain, were 0.78 microgram/ml and 3.1 micrograms/ml, respectively; the former value was similar to those of PIPC, DMPPC, CTM, and CTX, and the latter was similar to those of PIPC, DMPPC, CTX, and SBT/CPZ. Of 4 strains of Streptococcus pneumoniae, 2 strains were inhibited at 0.05 microgram/ml, and the others at 1.56 micrograms/ml; both values were similar to those of PIPC, SBT/CPZ. As for Gram-negative bacilli, 6 of 7 strains of H. influenzae did not produce beta-lactamase and 1 strain was a high producer. The MICs of TAZ/PIPC against beta-lactamase nonproducing strains were < or = 0.025 microgram/ml in 5 strains and 0.39 microgram/ml in 1 strain, and the values were similar to those of PIPC and SBT/CPZ. While the MIC of TAZ/PIPC against the high beta-lactamase producing strain was 0.78 microgram/ml; similar to that of SBT/CPZ and smaller than that of PIPC. 2. The results of clinical effects on 7 diseases in 33 cases were as follows: TAZ/PIPC was clinically judged "excellent" in 17 (51.5%); good in 14 (42.4%); fair in 2 (6.1%). No case with no response was seen in this study, and the total efficacy rate of "excellent" and "good" was 93.9%. 3. Bacteriological effects were evaluated in 17 strains of 4 species, and all of them were eradicated. 4. Adverse reactions were judged in 35, which consisted of 33 in which the clinical effects were evaluated and 2 dropped from this study. Of these cases, diarrhea was observed in 4 (11.4%). 5. Laboratory tests revealed an increase in platelets in 1 of 32 cases (3.1%), and eosinophilia in 2 of 29 cases (6.9%). Biochemical profile showed an increase in GPT alone and abnormal increases in both GOT and GPT in 1 each out of 21 cases.

[Clinical study on azithromycin in 10% fine granules and 100mg capsules in the field of pediatrics].

Azithromycin (AZM), a new oral macrolide antibiotic, in 10% fine granules or 100 mg capsules was given to pediatric patients to treat various infections. The following results were obtained in our studies of AZM for its antibacterial activities against clinical isolates, its pharmacokinetics, its efficacy, and its safety. 1. MICs of AZM, erythromycin (EM) and clarithromycin (CAM) were determined against a total of 57 strains all at 10(6) cfu/ml. Among Gram-positive cocci, MICs of AZM ranged from 0.78 to > 100 micrograms/ml against Staphylococcus aureus (20 strains), from 0.05 to 0.1 microgram/ml against Streptococcus pyogenes (11 strains), and from 0.0125 to 3.13 micrograms/ml against Streptococcus pneumoniae (10 strains). These MICs were similar to those of the other macrolides. Among Gram-negative bacilli, MICs of AZM were 0.05 micrograms/ml against Moraxella subgenus Branhamella catarrhalis (1 strain), from 0.78 to 3.13 micrograms/ml against Haemophilus influenzae (9 strains), 0.78 micrograms/ml against Haemophilus parainfluenzae (1 strain) and 6.25 micrograms/ml against salmonella sp. (1 strain). These values were similar to or lower than those of the other macrolides. Against Mycoplasma pneumoniae, MICs of AZM were < or = 0.0008 micrograms/ml in three strains. One strain of M. pneumoniae showed tolerance to AZM at MIC 25 micrograms/ml. The other agents exhibited higher MIC than AZM against this organism. 2. Plasma samples were collected from five patients receiving fine granules and four patients receiving capsules for drug level determination. The patients received AZM at 10.0 approximately 16.3 mg/kg body weight once daily for 3 days. Drug concentrations in plasma at two hours after Day 3 dosing were in a range between 0.02 and 0.19 micrograms/ml for fine granules and were in a range between 0.11 and 0.42 micrograms/ml for capsules. 3. Urine samples were collected from four patients receiving fine granules and four patients receiving capsules. Drug levels were determined to be 3 micrograms/ml at post-treatment 48 hours for fine granules and post-treatment 72 hours for capsules. Urinary excretion rates of AZM in three patients on capsules lied in a range between 4.69 and 10.17%. 4. Effectiveness of AZM in fine granules was evaluated in 128 patients having a total of 19 different infections. AZM was rated "excellent" in 51 patients, "good" in 63, "fair" in 8, "poor" in 6, resulting in an efficacy rate of 89.1%. Effectiveness of AZM in capsular form was evaluated in 23 patients with five different infections. AZM was found "excellent" in 13 patients and "good" in 10, resulting in an efficacy rate of 100%. 5. AZM in fine granules eradicated 45 strains of 54 in 8 different bacteria. AZM in capsules eradicated 9 strains of 10 strains in 6 different bacteria. 6. As for adverse reactions, one patient complained of eruption, one vomiting, one loose stool, five diarrhea, when administered with fine granular form of AZM. One patient on AZM capsules experienced urticaria and vomiting. 7. As for abnormal laboratory changes, three patients were found with decreased WBC, seven with increased eosinophil, two with increased GOT and GPT, one with increased GPT. They were all on fine granular form of AZM. As far as abnormalities found in patients administered with AZM in capsular form, two showed decreased WBC, one decreased WBC along with increased eosinophil, and three increased eosinophil.

All-optical modulation with anomalous photovoltaic film on a Ti:LiNbO(3) waveguide modulator.

An anomalous photovoltaic film formed by simultaneous oblique sputter deposition of CdTe and CdS from different directions was integrated onto LiNbO(3) and combined with a Mach-Zehnder-type interferometric waveguide modulator. Irradiation by 830-nm laser light with low intensity near 1 mW of the photovoltaic film induced anomalous photovoltages of ~5 V, which is as high as the half-wave voltage. This photovoltage was used to control the signal light in the waveguide. Modulation by external light was demonstrated with a response time of 0.1 s. Because of the presence of CdS with a photoconductive effect, the response time was much faster than that of conventional anomalous photovoltaic films formed by oblique deposition of CdTe.

[Pharmacokinetic and clinical evaluation of cefozopran in premature and newborn patients].

Cefozopran (SCE-2787, CZOP), which is already on the market with a variety of approved indications in infectious diseases for adult patients, was administered to premature and newborn patients to evaluate the pharmacokinetics and the clinical efficacy. 1. Pharmacokinetics CZOP was intravenously administered at doses of 10.0 mg/kg, 21.4 mg/kg and 40.0 mg/kg to premature and newborn patients, and the blood concentrations and urinary excretion rate were examined. The blood CZOP concentrations were 31.7 and 65.5 micrograms/ml at 30 minutes after administration of 10.0 mg/kg and 40.0 mg/kg, respectively. The elimination half life was 1.78 hours and 2.31 hours, and the urinary recovery was 110.7% and 53.7% within 6 hours after administration, respectively. In the patient given 21.4 mg/kg, the blood CZOP concentration was 36.4 mg/kg at 1 an hour after administration and the elimination half life was 3.97 hours. The urinary recovery was 29.6% within 5 hours after administration. 2. Clinical results The clinical efficacy was evaluated in 19 patients and judged "good" or better in 13 of them with the efficacy rate or 68.4%. The bacteriological response was evaluated in 10 patients from whom Gram-positive cocci of S. aureus (6 strains), S. pneumoniae (1 strain) and E. faecalis (1 strain) and Gram-negative bacilli of H. influenzae (2 strains) and E. coli (2 strains) were isolated as possible causative organisms. With exception of 1 strain each of S aureus and H influenzae, which were not tested after the treatment with CZOP, all of these strains were found to be eradicated. 3. Adverse drug reactions (ADRs) of signs and symptoms and abnormal alterations of laboratory test values. Safety evaluation was made in 24 patients. ADRs of signs and symptoms were recognized in none of them. As abnormal alterations of laboratory test values, increased eosinophils in 3 patients, elevated GOT in one and elevated GPT in one were recognized. These results indicate that CZOP is a drug useful for treatment of infections in premature and newborn patients.

[Pharmacokinetic, bacteriological and clinical studies of SY5555 in the pediatric field].

Pharmacokinetic, bacteriological and clinical studies on SY5555, a new oral penem, were carried out, and the following results were obtained. 1. MICs were determined for 6 drugs, SY5555, clavulanic acid/amoxicillin (CVA/AMPC), cefaclor (CCL), cefotiam (CTM), cefpodoxime (CPDX), cefdinir (CFDN) against 20 strains of bacteria isolated from patients who were subsequently treated with SY5555. MICs of SY5555 for Gram-positive cocci ranged from 0.05 to 0.10 microgram/ml against 10 strains of Staphylococcus aureus. The MIC was < or = 0.025 microgram/ml against one strain of Streptococcus pyogenes, and MICs were from < or = 0.025 to 0.39 microgram/ml against Streptococcus pneumoniae. These MIC values were equivalent or superior to those of the other 5 drugs. MICs of SY5555 for Gram-negative bacilli were 0.39 and 6.25 micrograms/ml against Haemophilus influenzae, and these values were equivalent to those of the other drugs, except CPDX. The MIC of SY5555 was 0.39 microgram/ml against 2 strains of Escherichia coli, and this value was equivalent or superior to those of CVA/AMPC and CCL, similar or inferior to those of CPDX and CFDN, and inferior to that of CTM. The MICs of several drugs were determined for 10 strains of Bordetella pertussis and 30 strains of Campylobacter jejuni isolated from patients before this clinical study. The MICs of SY5555 against the 10 strains of B. pertussis were compared with those of 7 drugs, CCL, CTM, CPDX, ampicillin (ABPC), piperacillin (PIPC), imipenem (IPM) and erythromycin (EM). The MIC of SY5555 was 0.78 microgram/ml against all of the strains. This value was superior to those of CCL, CTM and CPDX, similar or inferior to that of IPM and inferior to those of PIPC and EM. The MICs of SY5555 against the 30 strains of C. jejuni were compared with those of 7 drugs. CCL, CTM, CPDX, CFDN, ABPC, IPM and EM, and the MIC of SY5555 was < or = 0.025 microgram/ml or 0.05 microgram/ml and these values were equivalent or superior to those of the 7 reference drugs. 2. SY5555 dry syrup was administered orally at 30 min. after meals, to a total of 5 patients, at doses of 5.0 and 10.0 mg/kg to 2 patients each and at a dose of 15.0 mg/kg to one patient and the plasma concentrations were determined. Peak concentrations were detected 1 to 3 hours after administration in all patients and the peak concentrations were 0.93 and 1.21 micrograms/ml at the 5.0 mg/kg dose, 2.85 and 5.49 micrograms/ml at the 10.0 mg/kg dose and 5.79 micrograms/ml at the 15.0 mg/kg dose.(ABSTRACT TRUNCATED AT 400 WORDS)

Catheter-related infections by Hansenula anomala in children.

During August and September, 1992, we experienced 4 cases of Hansenula anomala (H. anomala, synonym Pichia anomala) fungemia in immunocompromised patients. Two patients had been suffering from a malignant disease, 3 of them had received broad-spectrum antibiotics and a central venous catheter (CVC) had been inserted in all of them. H. anomala was isolated as the sole pathogen from all 4 patients. Three of them responded favorably to fluconazole after withdrawal of the catheter, but one failed. H. anomala should be considered as a possible cause of catheter-related infections.

Detection of cytomegalovirus DNA in urine from newborns in NICU using a polymerase chain reaction.

To investigate the natural course of viral shedding during the newborn period, the presence of Cytomegalovirus (CMV) DNA in specimens at 3, 7, 14, 21 and 28 days of life was examined using the polymerase chain reaction (PCR) method. At the 3rd day of life, the viral DNA positive rate in the urine was 7% (4/60), at the 7th day 7% (3/46), at the 14th day 10% (2/20), at the 21st day 10% (1/10), and at the 28th day 25% (1/5). CMV was also detected in samples co-cultivated with HeLa 229 cells and this positive rate was 5% (3/60). The viral positive rate in newborns did not correlate with the gestational age, body weight, or serum IgM level. Six congenital infection cases were identified; two of which were small-for-date babies (SFD) and three of which were born with premature rupture of membranes (PROM). They had no complications during the six months after birth.

Genetic variation in VP7 gene of human rotavirus serotype 2 (G2 type) isolated in Japan, China, and Pakistan.

Sequence analysis of the gene encoding the major neutralization glycoprotein (VP7) was performed on sixteen human isolates of serotype 2 of rotavirus in Japan, China, and Pakistan and their genetic variations were examined. Comparative studies of their nucleotide and deduced amino acid sequences between the sixteen isolates and the HU5 strain revealed an overall homology of more than 94%. A higher degree of homology in nucleotides was observed among the sixteen isolates than between HU5 and the isolates. A total of thirteen amino acid residues frequently converted to another amino acid. Out of the thirteen, five amino acid residues belonging to the major neutralizing epitope regions (C, E, and F in this communication) converted frequently. From the amino acid sequences three subtypes, subtype 1, subtype 2, and intermediate, were suggested to be classified as previously reported for serotype 1 (Xin et al, Virology, 1993, 197: 813-816).

[A child with iritis due to Chlamydia pneumoniae infection].

A case of uncommon iritis due to Chlamydia pneumoniae (C. pneumoniae) is reported. The patient was a 9-year-old boy who had suffered from cough, pharyngeal pain, and low grade fever. The symptoms persisted for more than 1 month in spite of an oral cephem antibiotic. Ophthalmalgia, congestion around the iris and cough had lasted with alleviation and exacerbation. A diagnosis of C. pneumoniae infection was made by specific polymerase chain reaction (PCR) method and microimmunofluorescence test (MIF). The symptoms subsided with administration of clarithromycin (CAM: 300 mg/day) for 2 weeks. Because of the simultaneous alleviation of iritis, C. pneumoniae infection was considered to introduce the iritis. Much remains to be clarified about this pathogenesis of iritis and more detailed evaluations are required.

[Bacteriological, pharmacokinetic and clinical studies on biapenem (L-627) in the pediatric field].

Antibacterial activities were determined and pharmacokinetics and a clinical studies were performed on biapenem (L-627), a novel parenteral carbapenem antibiotic, in infections in children. The following results were obtained: 1. MICs of L-627 against clinical isolates were as follows: Among Gram-positive bacteria, MICs were 0.78 microgram/ml to > 100 micrograms/ml against 3 strains of methicillin-resistant Staphylococcus aureus (MRSA), and 0.10 microgram/ml to 0.39 microgram/ml against 8 strains of methicillin-sensitive S. aureus (MSSA), MICs against 5 of them were similar to those of imipenem (IPM), and MICs against 3 of them were slightly higher than those of IPM. MICs were < or = 0.025 microgram/ml to 0.39 microgram/ml against 7 strains of Streptococcus pneumoniae, and were similar to those of IPM, and lower than those of ceftazidime (CAZ) and piperacillin (PIPC). Among Gram-negative bacteria, MICs were 0.78 microgram/ml and 3.13 micrograms/ml against 2 strains of Haemophilus influenzae, and were similar to those of IPM. 2. Maximum plasma concentrations determined by the bioassay method after intravenous infusion of L-627 over 30 minutes at doses of 6.0 and 12.0 mg/kg, respectively, in 2 different pairs of 2 children each (total 4 cases) were observed upon completion of the treatment. Maximum concentrations at a dose of 6.0 mg/kg were 28.8 micrograms/ml and 24.6 micrograms/ml, and at a dose of 12.0 mg/kg were 65.4 micrograms/ml and 39.6 micrograms/ml, exhibiting a dose response. Plasma half lives in the beta phase were 0.97 and 1.20 hours at 6.0 mg/kg, and 0.72 and 0.94 hour at 12.0 mg/kg. Plasma concentrations determined by the HPLC method were lower than those determined by the bioassay. 3. Urinary excretion rates in the first 5.5 hours after the 6.0 mg/kg dose were 81.4 and 75.3%, and after the 12.0 mg/kg dose were 91.0 and 73.8%, and these values were higher than those obtained using HPLC. 4. Concentrations of L-627 in cerebrospinal fluid were determined in 2 cases of purulent meningitis. In one case, 30.3 mg/kg of L-627 was infused intravenously over 30 minutes and concentrations on days 1, 3, 7 and 14 observed at 60, 60, 45 and 45 minutes after respective dosages were 7.60, 1.30, 1.42 and 0.38 microgram/ml. Cerebrospinal fluid-plasma concentration ratio was determined on days 7 and 14 to be 5.5 and 1.2% respectively.(ABSTRACT TRUNCATED AT 400 WORDS)