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Biomedical subjects

H Meguro

Publications and source records attributed to H Meguro.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Antibacterial activities of a carbapenem antibiotic, biapenem (L-627), against penicillin-resistant Streptococcus pneumoniae].

Antibiotic susceptibilities were evaluated for 48 strains of Streptococcus pneumoniae collected in 1992-1993 at Ichihara City of Chiba Prefecture. Twenty two (46%) of the 48 strains were benzylpenicillin (PCG) insensitive or resistant (PRSP) judged from the MICs of PCG to higher than 0.1 microgram/ml. MICs of piperacillin and cefotaxime increased as the MICs of PCG increased. However, elevations of MICs of imipenem and biapenem (L-627) were small in spite of the increases of MICs of PCG. L-627 was effective in a case of purulent meningitis due to PC-insensitive S. pneumoniae. Thus, L-627 is a candidate to be used in treatment of PRSP infections including purulent meningitis.

Humans↗
PubMed1994

[Clinical evaluation of a new carbapenem antibiotic, biapenem (L-627), in the pediatric field].

Biapenem (L-627) was evaluated for its safety and efficacy in 27 children with various bacterial infections. L-627 was effective in cases with osteomyelitis due to Staphylococcus aureus, pneumonia and purulent meningitis due to penicillin-resistant Streptococcus pneumoniae, and urinary tract infections due to Enterococcus faecalis, Escherichia coli, or Pseudomonas aeruginosa. However, L-627 failed to produce good responses in 2 of 7 cases of Haemophilus influenzae infections. Pharmacokinetic parameters of 30-minutes infusion of 12 mg/kg were as follows: Cmax 29-46 micrograms/ml, T 1/2 0.68-0.94 hr. Adverse reactions were minimal. These data suggest that L-627 is safe in children, and is valuable especially for treatment of infections in immunocompromised hosts and infections due to multiply resistant bacteria.

Adolescent↗
PubMed1994

[Pharmacokinetic and clinical studies with cefozopran in the pediatric field. Pediatric Study Group of Cefozopran].

We investigated pharmacokinetics and clinical effectiveness of a newly developed cephem antibiotic cefozopran (SCE-2787, CZOP) against various pediatric infections in 18 institutions and their affiliates. We obtained the following results. 1. Serum concentration and urinary excretion rates Pharmacokinetics of CZOP in children was examined after intravenous injection and 30-minute drip infusion of 10, 20 and 40 mg/kg of CZOP. Peak serum concentrations of CZOP in 30 minutes after intravenous injection were 21.7, 51.5 and 77.8 micrograms/ml, respectively, showing a clear dose response. Half-lives were 1.99, 1.85 and 1.67 hours, respectively. In the first 6 hours after administration, urinary excretion rates of CZOP were 87.3, 67.4 and 84.1%, respectively. In the cases of 10, 20 and 40 mg/kg administration of CZOP 30-minute drip infusion, peak serum concentration of CZOP in 30 minutes, when the infusion was completed, were 38.1, 72.8 and 95.6 micrograms/ml, respectively. Again, there was a clear dose response. Half-lives were 1.67, 1.69 and 1.43 hours, respectively. In the first 6 hours after administration, urinary excretion rates of CZOP were 53.9, 59.7 and 77.3%, respectively. Cerebrospinal fluid concentrations of CZOP administered by intravenous injection of 50 mg/kg to patients with purulent meningitis were 1.6 to 43.4 micrograms/ml in 1 to 1.5 hours after administration. 2. Clinical study Clinical efficacy was evaluated in 337 cases. The largest number of cases, 138 cases, were found in 2 to < 6-year olds. The majority of the patients were under age 9, and 70 cases were of less than 1-year old infants. 183 cases were males and 154 cases were females. In terms of illness, a majority, or 185 cases, suffered from pneumonia, followed by 39 cases of UTI and 23 infections of the skin and soft tissue. There were 7 cases of purulent meningitis. In 218 cases, CZOP was administered at a daily dose of 60- < 80 mg/kg. The drug was administered for 6-10 days, the most frequent duration, in 188 cases. In the cases where causative organisms were identified (group A), the efficacy rates ("excellent" and "good") obtained were 100% (5/5) against purulent meningitis, 100% (2/2) against sepsis, 98.3% (119/121) against pneumonia, 100% (13/13) against acute bronchitis, 100% (11/11) against upper respiratory tract infection, 96.3% (26/27) against UTI. Overall, "excellent" and "good" responses were observed in 97.5% (197/202) of cases with known causative organisms.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1994

[Clinical studies of arbekacin sulfate in the pediatric field].

UNLABELLED: A clinical investigation was carried out to evaluate arbekacin, an aminoglycoside, in the treatment of MRSA infections (pneumonia, septicemia, etc.) of pediatric patients. The obtained results are summarized as follows. 1. CLINICAL RESULTS: Excluding those patients who met the present exclusion criteria and withdrawal cases from a total of 18 patients, 10 patients (3, 6, and 1 cases of septicemia, pneumonia, and urinary tract infection, respectively) were subjected to clinical evaluation. These were composed of 1, 1, 6, and 2 cases of neonate, infants, pre- and school age children, respectively. Excellent, good and fair results were obtained in 5, 2, and 3 patients, respectively; thus, the efficacy rate was 70.0%. The efficacy rate by disease was 100%, 50.0% and 100% in septicemia, pneumonia, and urinary tract infection, respectively. The bacteriological eradication were obtained in 70.0% of the total patients; by disease, these rates were 100% and 50.0% in septicemia/urinary tract infection and in pneumonia, respectively. The MIC50 as well as the MIC80 against MRSA strains isolated from 9 patients were 0.39 microgram/ml and 1.56 micrograms/ml, respectively. No adverse reactions were observed in the 15 patients, while in laboratory test values, one case each out of 12 patients examined showed gamma-GTP elevation, proteinuria, and hematuria. 2. Pharmacokinetics: The pharmacokinetics of the agent was investigated in a total of 9 patients, which included 1 neonate and 4 cases each of pre- and school age children. The Cmax, 4.85-8.83 micrograms/ml, was observed immediately after the termination of the instillation. The T1/2's were 4.96 hours, 1.24-2.54 hours, and 1.78-1.88 hours in the neonate, the pre- and the school age children, respectively; in the neonate the half-life was longer. When 1.92-2.7 mg/kg were administered to 3 each of the pre- and school age children, urinary excretion rates in the first 6-8 hours were 40.1-56.5% of the dosages administered. In all cases, the urinary concentrations were highest in the first 2 hours, after the administration, and then gradually decreased. These results suggest that arbekacin is a useful antibiotic for treating MRSA infections in the pediatric field.

Adolescent↗
PubMed1994

[Pharmacokinetic and clinical studies of SY5555 in the pediatric field. Pediatric Study Group of SY5555].

SY5555, a new oral penem, was pharmacokinetically and clinically evaluated in the pediatric field and the following results were obtained: 1. Pharmacokinetics Pharmacokinetics of SY5555 dry syrup (powder which is dissolved before use) was investigated in 64 children. At a dose level of 3 mg (potency)/kg, Cmax and T1/2 were 0.33 micrograms/ml and 0.95 hours (n = 1), respectively, in the non-fasting state. At a dose level of 5 mg/kg Cmax and T1/2 were 2.09 +/- 1.25 micrograms/ml and 1.20 +/- 1.07 hours, respectively, in the fasting state, and were 1.21 +/- 0.70 micrograms/ml and 1.33 +/- 0.90 hours, respectively, in the non-fasting state. At a dose level of 10 mg/kg, Cmax and T1/2 were 2.96 +/- 1.89 micrograms/ml and 0.89 +/- 0.43 hours, respectively, in the fasting state, and were 2.45 +/- 1.37 micrograms/ml and 1.17 +/- 0.53 hours, respectively, in the non-fasting state. At a dose level of 15 mg/kg, Cmax and T1/2 were 4.30 +/- 2.15 micrograms/ml and 0.82 +/- 0.09 hours, respectively, in the non-fasting state. Data of Cmax and AUC showed that plasma concentration of the drug depended on dose levels. Urinary recovery rates in the first 6 hours were 1.71% (n = 1) in the non-fasting state at a dose level of 3 mg/kg, 4.13 +/- 1.40% in the fasting state and 4.17 +/- 3.29% in the fasting and the non-fasting state, respectively at a dose level of 5 mg/kg, and 6.02% (n = 1) and 4.64 +/- 2.81%, respectively, at a dose level of 10 mg/kg. At a dose level of 15 mg/kg, urinary recovery rate in the first 6 hours was 7.97% (n = 2) in the non-fasting state. 2. Clinical results 1) Dry syrup The clinical efficacy of the SY5555 dry syrup was evaluated in 506 cases. SY5555 was administered at daily doses of 15-30 mg/kg divided into 3 equal doses to most patients. Daily doses of 12- < 18 mg/kg were given to 46.6% of the patients. The overall clinical efficacy rate was 92.9%, and this drug was effective in 93.0% of the 301 patients for whom the causative pathogens were identified, and in 92.7% of the 205 patients with infections for whom the causative pathogens were unknown. The efficacy rate at daily doses of 12 - < 18 mg/kg was 94.5% similar to those obtained at daily doses of 18- < 27 mg/kg (91.7%) or 27- < 33 mg/kg (91.3%). The bacteriological eradication rate was 82.3%.(ABSTRACT TRUNCATED AT 400 WORDS)

Absorption↗
PubMed1993

Selective expression of the glutamate receptor channel delta 2 subunit in cerebellar Purkinje cells.

The primary structure of a putative subunit of the mouse glutamate receptor channel, designated as the delta 2 subunit, has been deduced by cloning and sequencing the cDNA. The delta 2 subunit has four putative transmembrane segments characteristic for neurotransmitter-gated ion channels, and shares 56% amino acid sequence identity with the delta 1 subunit of the mouse glutamate receptor channel and 14-24% identity with the subunits of the AMPA-, kainate- or NMDA-selective glutamate receptor channel. RNA blot and in situ hybridization analyses show that the delta 2 subunit mRNA is localized in cerebellar Purkinje cells. Furthermore, immunoblot and immunohistochemical analyses suggest that the delta 2 subunit protein is actually expressed in vivo in Purkinje neurons. The selective localization of the delta 2 subunit in Purkinje cells may imply a role of the delta 2 subunit in Purkinje cell-specific function such as the cerebellar LTD.

Amino Acid Sequence↗
PubMed1993

Simultaneous determination of hydroperoxides of phosphatidylcholine, cholesterol esters and triacylglycerols by column-switching high-performance liquid chromatography with a post-column detection system.

A method for the simultaneous determination of hydroperoxides of phosphatidylcholines (PC), triacylglycerols (TG) and cholesterol esters (CE) has been developed. A sample was separated into a combined TG and CE hydroperoxides fraction and a PC hydroperoxides fraction on a short silica column. The fractions were introduced into an ODS column and another silica column by a valve-switching device. The PC hydroperoxides were monitored by a post-column detection system with diphenyl-1-pyrenylphosphine, and the TG and CE hydroperoxides were monitored by another switching device. With this system, the hydroperoxides were determined at the picomole level within 32 min. Their detection limits were 2-4 pmol at a signal-to-noise ratio of 3, and the relative standard deviations of the peak areas were 1.6-3.1%. This method was successfully applied to determine lipid hydroperoxides in human plasma.

Cholesterol↗
PubMed1993

Determination of triacylglycerol and cholesterol ester hydroperoxides in human plasma by high-performance liquid chromatography with fluorometric postcolumn detection.

Cholesterol ester (ChE) and triacylglycerol (TG) hydroperoxides in human plasma were determined by high-performance liquid chromatography with postcolumn detection with diphenyl-1-pyrenylphosphine. Human plasma was extracted once with n-hexane. 2,6-Di-tert.-butyl-4-methylphenol and N-stearylcinnamide were added to human plasma before extraction as an antioxidation agent and an internal standard, respectively. The detection limits of both ChE and TG hydroperoxides were 1 pmol. The sample size was minimized to 250 microliters for each run. The recoveries of ChE and TG hydroperoxides from fresh plasma were ca. 90 and 80%, respectively. The relative standard deviations (n = 8) of their values in frozen human plasma were 5.4% (ChE hydroperoxides, 298 nM) and 5.7% (TG hydroperoxides, 267 nM). No TG hydroperoxides and 24.5 +/- 9.6 nM (n = 15) ChE hydroperoxides were detected in fresh human plasma. The relative standard deviation (n = 8) of ChE hydroperoxides values in fresh plasma was 5.8% (27.1 nM).

Cholesterol Esters↗
PubMed1993

A convenient evaluation of the stereoselectivity of lipase-catalyzed hydrolysis of tri-O-acylglycerols on a chiral-phase liquid chromatography.

A general method was developed using chiral-phase chromatography in order to evaluate the stereoselectivities of lipases-catalyzed hydrolysis of tri-O-acylglycerols independent of acyl groups. 1,2-Di-O-acyl-sn-glycerols or its enantiomer 2,3-di-O-acyl-sn-glycerols in the enzymatic reaction mixtures were derivatized to the key compound, 1,2-di-O-benzoyl-3-O-tert-butyldimethylsilyl-sn-glycerol 2 (+) or its enantiomer 2' (-), respectively. The enantiomers were separated on a chiral-phase HPLC, and the method was highly sensitive to determine the stereoselectivities of lipases.

Chromatography, High Pressure Liquid↗
PubMed1993

Determination of the lipase stereoselectivities using circular dichroism (CD); lipases produce chiral di-O-acylglycerols from achiral tri-O-acylglycerols.

A general method was described to determine the optical purity of 1,2 (or 2,3)-di-O-acylglycerols via a key compound, 3 (or dibenzoyl-sn-glycerol (3 or 3'). The chiral di-O-acylglycerols were first silylated and the acyl groups were removed by the Grignard degradation to 3 (or 1) O-tert-butyldimethylsilyl-sn-glycerol and subsequent benzoylation lead to the key compound 3 or 3' without racemization. The optical purity was determined from the strong exciton Cotton effect of 3 (+) or 3' (-) at 238 nm in the concentration of ca. 1 mM. The method was successfully applied to determine the stereoselectivities of lipases (EC 3.1.1.3) from three origins, bacteria, mammal and fungus such as Pseudomonas (AP, 89% optical purity, sn-1 preference), porcine pancreatin (PPL, 9.3% optical purity, sn-3 preference) and Candida (CC, sn-2 preference) using tripalmitin. The similar studies were extended to tri-O-benzoylglycerol (6) and tri-O-(cyclohexanecarbonyl)glycerol (5). All the enzymes showed high stereoselectivities with tri-O-benzoylglycerol. PPL and AP showed high and low stereoselectivities with tri-O-(cyclohexanecarbonyl)glycerol, while low and high stereoselectivities with tri-O-palmitoylglycerol, respectively. The results show that the stereoselectivities are ruled by the origins of lipases and acyl groups. The structures of the recognition site might be associated with enantioselectivities of the enzymes.

Animals↗
PubMed1993

Synthesis of 4'-C-methylnucleosides.

Several 4'-C-methylnucleosides were prepared. 1H-NMR studies on these nucleotides showed that they have the 3'-exo furanose ring conformation different from the 3'-endo conformation of natural nucleosides.

Magnetic Resonance Spectroscopy↗
PubMed1993

[Criteria for clinical evaluation of antibiotics in pediatrics. The purpose and process for establishing the criteria].

This paper describes the purpose and process for establishing "Criteria for Clinical Evaluation of Antibiotics in the Pediatric Field", which was reported in the Japanese Journal of Antibiotics Vol. 46, May, 1993. The Criteria Committee was organized in November 1991. Four meetings were held to establish the draft criteria. The criteria were applied to the evaluation of oral cephem S-1108 and parenteral cephem SCE-2787. When the criteria were compared with the conventional criteria, the results indicated that no difference was obtained in the efficacy rate as a whole, the sum of "Good" and "Excellent" cases, but there was a difference in the cases judged to be "Excellent". Partial alteration was made to the draft criteria and the Committee produced the final version of the criteria. However, the criteria are far from complete, so it will be subjected to further revision it accordance with future advance in chemotherapy.

Bacterial Infections↗
PubMed1993

[Effect of cefditoren pivoxil on carnitine metabolism in pediatric patients].

Carnitine metabolism was studied in 16 pediatric patients with various infections under the treatment with cefditoren pivoxil (CDTR-PI) in granular form. Pivalic acid released from pivaloyloxymethyl ester of the drug was metabolized to pivaloylcarnitine. As results, an increase in urinary carnitine excretion (predominantly as pivaloylcarnitine) and, a decrease in free carnitine concentration and a high acyl/free carnitine ratio in serum (plasma) were observed during the treatment. When the dosing was terminated, pivaloylcarnitine in plasma and then in urine disappeared, and the concentration of free carnitine, acyl/free carnitine ratio returned to the normal range. No carnitine-related side effects were observed throughout the study.

Bacterial Infections↗
PubMed1993

[Clinical evaluation of S-1108 in children].

A new oral cephem antibiotic, S-1108, was evaluated for its clinical efficacy and safety in children. S-1108 was effective in 95% of the 59 examined cases of respiratory, middle ear, skin and urinary tract infections. S-1108 was highly effective in infections of Streptococcus pyogenes, Haemophilus influenzae and Escherichia coli, but was less effective in penicillin-resistant Streptococcus pneumoniae and Staphylococcus aureus infections. The serum half-life was 1.26 +/- 0.36 hours upon after meal administration of 4 mg/kg. No severe adverse reaction was encountered. From these data, S-1108 appears to be safe and effective in children with susceptible bacterial infections.

Bacterial Infections↗
PubMed1993

[A clinical study on cefditoren pivoxil granules in the pediatric field].

The clinical efficacy of cefditoren pivoxil (CDTR-PI, ME 1207) was evaluated in 45 patients with various infections. CDTR-PI was administered after meals at a dose of 3 mg/kg t.i.d. to most patients. The clinical efficacy rate was 95.3%. As side effects, diarrhea occurred in 2 patients. Cefditoren showed excellent antibacterial activities against Haemophilus influenzae, Streptococcus pyogenes and Streptococcus pneumoniae, and was more effective against Staphylococcus aureus than other cephems.

Administration, Oral↗
PubMed1992

Molecular diversity of the NMDA receptor channel.

Two novel subunits of the mouse NMDA receptor channel, the epsilon 2 and epsilon 3 subunits, have been identified by cloning and expression of complementary DNAs. The heteromeric epsilon 1/zeta 1, epsilon 2/zeta 1 and epsilon 3/zeta 1 NMDA receptor channels exhibit distinct functional properties in affinities for agonists and sensitivities to competitive antagonists and Mg2+ block. In contrast to the wide distribution of the epsilon 1 and zeta 1 subunit messenger RNAs in the brain, the epsilon 2 subunit mRNA is expressed only in the forebrain and the epsilon 3 subunit mRNA is found predominantly in the cerebellum. The epsilon 1/zeta 1 and epsilon 2/zeta 1 channels expressed in Xenopus oocytes, but not the epsilon 3/zeta 1 channel, are activated by treatment with 12-O-tetradecanoylphorbol 13-acetate. These findings suggest that the molecular diversity of the epsilon subunit family underlies the functional heterogeneity of the NMDA receptor channel.

Amino Acid Sequence↗