Molecular characterization and histochemical demonstration of salmon olfactory marker protein in the olfactory epithelium of lacustrine sockeye salmon (Oncorhynchus nerka)

Despite the importance of olfactory receptor neurons (ORNs) for homing migration, the expression of olfactory marker protein (OMP) is not well understood in ORNs of Pacific salmon (genus Oncorhynchus). In this study, salmon OMP was characterized in the olfactory epithelia of lacustrine sockeye salmon (O. nerka) by molecular biological and histochemical techniques. Two cDNAs encoding salmon OMP were isolated and sequenced. These cDNAs both contained a coding region encoding 173 amino acid residues, and the molecular mass of the two proteins was calculated to be 19,581.17 and 19,387.11Da, respectively. Both amino acid sequences showed marked homology (90%). The protein and nucleotide sequencing demonstrates the existence of high-level homology between salmon OMPs and those of other teleosts. By in situ hybridization using a digoxigenin-labeled salmon OMP cRNA probe, signals for salmon OMP mRNA were observed preferentially in the perinuclear regions of the ORNs. By immunohistochemistry using a specific antibody to salmon OMP, OMP-immunoreactivities were noted in the cytosol of those neurons. The present study is the first to describe cDNA cloning of OMP in salmon olfactory epithelium, and indicate that OMP is a useful molecular marker for the detection of the ORNs in Pacific salmon.

OmpC and OmpF are required for growth under hyperosmotic stress above pH 8 in Escherichia coli

AIMS

To investigate the requirement of outer membrane porins for osmotic adaptation at alkaline pH in Escherichia coli.

METHODS AND RESULTS

Escherichia coli mutants deficient in ompC, ompF and both genes were constructed and the growth of these mutants was observed at alkaline pH. The growth rate of the mutant deficient in both ompC and ompF was slower than that of the wild type and mutants deficient in one of these genes under hyperosmotic stress at pHs above 8.0. The decreased rate was recovered when a cloned ompC was introduced to the mutant, but the growth recovery with a cloned ompF was partial. Such growth diminution was not observed at pHs below 8.0.

CONCLUSION

OmpC and OmpF were shown to participate in hyperosmotic adaptation at alkaline pH in E. coli.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first report to demonstrate that OmpC and OmpF are required for hyperosmotic adaptation at pHs above 8.0, but not below 8.0.

Effects of gonadotropin-releasing hormone analog on expression of genes encoding the growth hormone/prolactin/somatolactin family and a pituitary-specific transcription factor in the pituitaries of prespawning sockeye salmon

Gonadotropin-releasing hormone (GnRH) is a possible secretagogue of growth hormone (GH) and somatolactin (SL) in teleosts. Effects of GnRH on the levels of pituitary mRNAs encoding GH, prolactin (PRL), and SL were therefore examined in prespawning sockeye salmon (Oncorhynchus nerka). A capsule of GnRH analog (GnRHa) was implanted into the dorsal muscle of maturing sockeye salmon for 3 weeks. The levels of hormonal mRNAs were then determined by a quantitative dot blot analysis using single-stranded sense DNA of the same sequence of mRNA as the standard. Further, we analyzed effects of GnRHa on expression of the genes encoding pituitary-specific transcription factor (Pit-1/GHF-1). Relative levels of Pit-1/GHF-1 mRNAs were estimated by Northern blot analysis, which showed specific 2- and 3-kb bands of mRNAs. GnRHa significantly increased the level of SL mRNA in the males, but not in the females, compared to the control fish. It did not induce significant increases in the levels of GH and PRL mRNAs in both the males and the females. The levels of Pit-1/GHF-1 mRNAs in the control males tended to be higher than those in the initial controls, so that GnRHa might not be effective in enhancing expression of Pit-1/GHF-1 gene, except for the level of 3-kb Pit-1/GHF-1 mRNA in the females treated with 150 microg GnRHa. The pattern of changes in the levels of Pit-1/GHF-1 mRNAs were similar to those of GH and PRL mRNAs in both the males and the females and to that of SL mRNA in the females. These results indicate that, in prespawning sockeye salmon, GnRH can stimulate SL gene expression, but probably not through the Pit-1/GHF-1-dependent system.

Lacustrine sockeye salmon return straight to their natal area from open water using both visual and olfactory cues

Mechanisms of the amazing ability of salmon to migrate a long distance from open water to natal streams for spawning are still unknown. Lacustrine sockeye salmon (Oncorhynchus nerka) in Lake Toya offers an excellent model system for studying the orientation mechanism in open water, because mature fish return to the natal area with a high degree of accuracy. First we examined the percentage of fish returning to the natal area after they were released 7 km south of the natal area. Forty percent of control male mature fish and 25% of the fish blinded by injection of a mixture of carbon toner and corn oil into the eyeball were captured in the natal area within 5 days. Forty-four percent of fish with brass rings (control) and 31% of fish with NdFe magnetic rings which interfere with the magnetic cue were captured in the natal area within 3 days. These experiments suggested that, although the number of blinded fish captured in the natal area was less than that of the controls, the difference was not statistically significant. In the fish captured in the natal area within 3 or 5 days, fish which found the natal area using their olfactory cue after random swimming for a long time and returned to that area may be included. Hence we tracked fish telemetrically using an ultrasonic tracking system, and found that mature males released at a long distance (3.6 or 6.8 km) from the natal area swam straight to the vicinity of the natal area. Interference of the magnetic cue by the attachment of a magnetic ring did not affect their direct return. Blockage of the visual cue caused them to move randomly. These data suggest that lacustrine sockeye salmon return straight to the vicinity of the natal area using their visual cue and finally reach the exact homing point using their olfactory cue.

Characterization of species-specifically amplified SINEs in three salmonid species--chum salmon, pink salmon, and kokanee: the local environment of the genome may be important for the generation of a dominant source gene at a newly retroposed locus

Short interspersed repetitive elements (SINEs), known as the HpaI family, are present in the genomes of all salmonid species (Kido et al., Proc. Natl. Acad. Sci. USA 1991, 88: 2326-2330). Recently, we showed that the retropositional efficiency of the SINE family in the lineage of chum salmon is extraordinarily high in comparison with that in other salmonid lineages. (Takasaki et al., Proc. Natl. Acad. Sci. USA 1994, 91: 10153-10157). To investigate the reason for this high efficiency, we searched for members of the HpaI SINE family that have been amplified species-specifically in pink salmon. Since the efficiency of the species-specific amplification in pink salmon is not high and since other members of the same subfamily of SINEs were also amplified species-specifically in pink salmon, the actual sequence of this subfamily might not be the cause of the high retropositional efficiency of SINEs in chum salmon. Rather, it appears that a highly dominant source gene for the subfamily may have been newly created by retroposition, and some aspect of the local environment around the site of retroposition may have been responsible for the creation of this dominant source gene in chum salmon. Furthermore, a total of 11 sequences of HpaI SINEs that have been amplified species-specifically in three salmon lineages was compiled and characterized. Judging from the distribution of members of the same-sequence subfamily of SINEs in different lineages and from the distribution of the different-sequence subfamilies in the same lineage, we have concluded that multiple dispersed loci are responsible for the amplification of SINEs. We also discuss the additional possibility of horizontal transmission of SINEs between species. The availability of the sets of primers used for the detection of the species-specific amplifications of the SINEs provides a convenient and reliable method for identification of these salmonid species.

Methicillin-resistant Staphylococcus aureus empyema in children

Over a 14 year period, there were 20 patients who presented with staphylococcal empyema from whom methicillin-resistant Staphylococcus aureus (MRSA) was isolated. Twelve cases were community-acquired and 8 were hospital-acquired infections. Patients were treated with penicillinase-resistant penicillin, cephalosporin or carbapenem in combination with or without aminoglycoside. They were also treated with drainage or thoracentesis. However, they were refractory to treatment and 7 patients, 6 of whom were suffering from bacteremia, died. One bacteremic patient was treated with vancomycin and was cured. In an area of endemic MRSA, vancomycin may be the first choice in the initial treatment of staphylococcal empyema until antimicrobial susceptibility can be determined.

K1 antigen, serotype and antibiotic susceptibility of Escherichia coli isolated from cerebrospinal fluid, blood and other specimens from Japanese infants

K1 antigens, serotypes and antibiotic susceptibilities of Escherichia coli isolates from neonates and infants were investigated. The presence of K1 antigen was tested by the K1-specific phage method. The number of K1 positive strains was 27 (84%) of 32 isolates from cerebrospinal fluid, 11 (25%) of 44 from blood and 4 (22%) of 18 from other specimens. Fourteen (33%) of the K1 positive strains were serotyped as O16:H6, and 8, 7 and 5 were serotyped as O18ac:H7, O1:H7 and O7:H-, respectively. One of 5 of the K1 negative strains were distributed into 30 different combinations of O and H antigens. The ampicillin resistance rates were 19% in K1 positive strains and 45% in K1 negative ones. The incidence of chloramphenicol resistance was the same in K1 positive and negative strains (21%). Ampicillin resistance was not noted in O16:H6 strains, but the incidence of antibiotic resistance was high (65% to ampicillin and 53% to chloramphenicol) in the rough-type strains.

Septicemia in immunocompromised children and their intestinal flora

Quantitative fecal bacteriology was performed in eight immunocompromised children with septicemia. The most marked change observed was suppression of the anaerobic bacteria. In seven patients, the predominant organisms were aerobic gram-negative bacilli (GNB), and in six of these were the same as the causative organism of the septicemia. Thus, overgrowth of GNB in the gastrointestinal tract may result in invasion of the blood stream and septicemia in immunocompromised patients. To prevent this complication it is necessary to allow the normal intestinal flora to be maintained in these patients as long as possible. Antibiotics should therefore be prescribed with caution. For the same reason, use of immunosuppressive drugs should be kept to a minimum. Bacteriological examination of the stool and pharynx is useful in the management of immunocompromised patients.

[Clinical and pharmacokinetic evaluation of aztreonam in neonates]

Nine neonates were treated with aztreonam (AZT) and its clinical efficacy and side effects were evaluated. Six of the patients were treated with a combination of AZT and ampicillin. Ages of the patients ranged from 0 to 24 days, and their body weights ranged from 2,290 to 4,260 g. Doses of AZT ranged 18.8 to 23.7 mg/kg every 8 to 12 hours for 3 to 7 days. Three patients with infections including urinary tract infection, cervical abscess, and suspicion of sepsis, appeared to respond to the treatment of AZT alone. Among them, clinical results were excellent in 1, good in 2 patients. Those patients subjected to the combination therapy showed excellent response in 1 and good in 5. The drug was well tolerated, but 1 had diarrhea. The pharmacokinetics of AZT was studied in 9 patients. Their ages ranged from 0 to 30 days, and body weights ranged from 2,000 to 4,000 g. Serum concentrations of AZT were 27.2 to 48.3 micrograms/ml at 1 hour after single 20 mg/kg intravenous bolus injection, and the levels were 3.4 to 15.5 micrograms/ml at 6 hours in 5 infants heavier than 2,500 g. Elimination half-lives of AZT ranged from 1.57 to 3.72 hours (mean 2.72 hours). Serum concentrations of AZT were 21.6 to 41.8 micrograms/ml at 1 hour after single 20 mg/kg intravenous bolus injection, and the levels were 10.2 to 17.0 micrograms/ml at 6 hours in 3 infants lighter than 2,500 g. The elimination half-lives of AZT were 3.63 to 4.86 hours (mean 4.31 hours).(ABSTRACT TRUNCATED AT 250 WORDS)

[Pharmacokinetics and clinical studies on aztreonam in neonates and premature infants (the second report). Study on effectiveness and safety in combination therapy using aztreonam and ampicillin. A study of aztreonam in the Perinatal Co-research Group]

Pharmacokinetics and clinical effects were studied in a combination therapy with aztreonam (AZT) and ampicillin (ABPC) in neonates and premature infants. The results obtained are summarized as follows. 1. Pharmacokinetics (1) Average serum concentrations at 30 minutes after one-shot intravenous injection of AZT 20 mg/kg and ABPC 25 mg/kg to a 4-7 days age-group of neonates were 41.3 (AZT) and 30.5 (ABPC) micrograms/ml, respectively. They gradually decreased to 14.7 and 2.7 micrograms/ml at 6 hours after the administration, but the concentration of AZT was always higher than that of ABPC. (2) Serum half-lives (T1/2) in the 4-7 days age-group were 3.61 hours for AZT and 1.42 hours for ABPC, thus T1/2 of AZT was longer. However, T1/2 of AZT was scarcely affected in the concomitant administration of ABPC. (3) Urinary excretion of AZT in the concomitant administration to the 4-7 days age-group was 52.7%, which was the same or a little higher comparing to that in AZT alone administration. 2. Clinical studies (1) AZT and ABPC were concomitantly administered to 160 cases and 133 cases were evaluated for efficacy. Pathogenic organisms were identified in 29 cases (Group A) and the efficacy rate was 86.2% (25/29). The number of cases in which pathogenic organisms were not identified (Group B) was 50 and in this group, the efficacy rate was excellent, 94.0% (47/50). AZT and ABPC were concomitantly administered to 54 cases for prophylaxis and in all the cases the administrations showed prophylactic effect. (2) Bacterial changes were confirmed in 21 of the 29 cases in which pathogenic organisms were identified initially and all of these 21 cases showed bacterial eradication, i.e., the bacterial eradication rate in the treatment was 100%. (3) There were 2 cases in which side-effects were observed among the analyzed 152 cases (1.3%). The side effects found were 1 case each of diarrhea and eruption. Abnormal laboratory values were found in 23 cases (15.9%), i.e., eosinophilia (9 cases), platelet-increase (4), elevation of GOT (4), elevation of GOT and GPT (3) and others (3). From the above pharmacokinetics and clinical results, the combination therapy of AZT and ABPC is considered to be one of the useful empiric antibiotic-therapies when pathogenic organisms are unknown in the infections of neonates and premature infants.

[Pharmacokinetics and clinical studies on aztreonam in neonates and premature infants (the first report). Study on effectiveness and safety in mono-therapy with aztreonam. A study of aztreonam in the Perinatal Co-research Group]

Pharmacokinetics and clinical study of aztreonam (AZT) in neonates and premature infants were conducted with the following results: 1. Pharmacokinetics (1) Serum concentrations of AZT at 30 minutes after one-shot intravenous injection of 10 mg/kg and 20 mg/kg to neonates including premature infants were 20.6-26.6 micrograms/ml and 38.5-46.4 micrograms/ml, respectively, and decreased thereafter. A dose response was observed in the serum concentrations with administration of AZT 10 mg/kg and 20 mg/kg. (2) Serum half-lives (T1/2) tended to be shorter in both mature and premature infants as their day-ages increased and T1/2 tended to be prolonged in premature infants compared with mature infants. (3) Changes in serum concentration upon one-hour intravenous drip infusion of AZT 20 mg/kg were very similar to those upon one-shot intravenous injection. (4) Urinary excretions in the first 6 hours after one-shot intravenous injection of AZT 10 mg/kg or 20 mg/kg tended to increase in mature infants as they grew and showed excretion rate of 26.2-54.3% but those in premature infants did not show any specific tendency with rate of 17.5-45.1%. Urinary excretions upon intravenous drip-infusion showed a tendency very similar to those upon intravenous injection. 2. Clinical studies (1) Clinically evaluable cases of AZT treatment were 88 cases (91 diseases), in which pathogenic organisms were identified in 56 cases (Group A), i.e., sepsis 9, purulent meningitis 2, pneumonia 8, urinary tract infection (UTI) 33 and others. Total efficacy rate was 98.2% including "excellent" (39), "good" (16) and "fair" (1). Number of cases in which pathogenic organisms were unknown (Group B) was 11, i.e., suspected sepsis (4), pneumonia (3) and intrauterine infection (4) and the efficacy rate was 100% with "excellent" (4) and "good" (7). Thus, both group A and B showed excellent results. AZT was also given to 24 cases for prophylaxis and all the cases showed prophylactic effect of AZT.4+ Bacteriologically AZT was deemed effective in 53 cases out of 56 (Group A) with identified pathogens "eradicated" and "unchanged" (2), thus the bacterial eradication rate was 96.2%. (3) A minor degree of loose feces was observed in 1 (1.3%) of 80 cases as a side effect. Abnormal laboratory test values found were eosinophilia (3 cases), elevation of GOT and GPT (2), platelet-increase (1), elevation of GOT (1), and thrombocytopenia.elevation of GOT.GPT.LDH (1). Every one of these was of a minor degree and transient. From the above pharmacokinetics and clinical results, standard dosage of AZT to neonates and premature infants should be in a unit dose of 20 mg/kg, twice daily to those with ages between 0 and 3 days, and 2 to 3 times daily to those with ages 4 days and above, by intravenous injection or intravenous drip infusion.

[Clinical and pharmacokinetic evaluation of cefmenoxime in neonates and young infants]

Twenty-three newborn and young infants, including 13 low-birth-weight infants, were treated with cefmenoxime (CMX) and the clinical efficacy and side effects were evaluated. The ages of the patients ranged from 1 to 102 days, and their weights ranged from 0.83 to 4.19 kg. Doses given were 18-42 mg/kg every 6 to 12 hours for 2 to 16 days. Among 12 infants with bacterial meningitis and sepsis, the results were excellent in 2, good in 7 and fair in 3 patients. The drug was well tolerated and no adverse effects were observed in the 23 patients. Pharmacokinetic studies of CMX were done in 5 infants whose mean body weight was 3.03 kg (range 2.4 to 4.2 kg). Serum concentrations at 15 minutes after 10 mg/kg intravenous bolus injections were 35.6 and 55.7 micrograms/ml in two 12- and 18-day-old patients. In 3 patients with ages of 7, 7 and 24 days, serum concentrations were 54.6, 102 and 100 micrograms/ml, respectively, at 15 minutes after 20 mg/kg doses. Elimination half-lives of the drug were 1.3 to 1.5 (mean 1.4) hours in these patients. Excretion rates into urine in the first 8 hours were 30.3, 74.2, 77.6 and 85.6% in four patients given 10 or 20 mg/kg doses. The cerebrospinal fluid level at 3 hours after the dose was 0.4 micrograms/ml on 15th day of treatment in 1 patient with bacterial meningitis given 20 mg/kg every 6 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical and pharmacokinetic evaluation of imipenem/cilastatin sodium in neonates and young infants]

Twenty three neonates and young infants were treated with imipenem/cilastatin sodium (IPM/CS) and its clinical efficacy and side effects were evaluated. Ages of the patients ranged from 0 to 83 days, and their body weights ranged from 750 to 4,760 g. Doses of IPM/CS ranged from 17.4 to 21.5 mg/kg as IPM every 6 to 12 hours for 3 to 12 days. Sixteen patients with infections including sepsis, meningitis and pneumonia, appeared to have responded to the IPM/CS treatment. Among them, clinical results were excellent in 2, good in 12 and fair in 2 patients. The drug was well tolerated, but 1 patient had diarrhea, 1 had redness of body during infusion, 1 had elevated GOT and GPT, and 2 patients showed only elevated values of GOT only among the 23 patients. The pharmacokinetics of IPM/CS were studied in 7 patients. Their ages ranged from 0 to 9 days, and body weights ranged from 2.5 to 4.0 kg. Serum concentrations of IPM were between 18.0 and 96.9 micrograms/ml and those of CS ranged 31.7 and 144.5 micrograms/ml in 6 patients at the end of intravenous drip infusion 20 mg/20 mg/kg during 30 or 60 minutes. Elimination half-lives of IPM ranged from 1.2 to 2.0 hours, and those of CS ranged from 1.4 to 2.7 hours. Serum concentrations of IPM was 14.7 micrograms/ml and that of CS was 32.4 micrograms/ml in 1 patient at the end of 30 minute-drip infusion 10 mg/10 mg/kg. The elimination half-lives of IPM was 1.5 hours, and that of CS was 2.9 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical efficacy and pharmacokinetic evaluation of ceftizoxime in neonates and young infants]

Thirteen neonates and young infants, including 5 infants with very low birth weight, were treated with ceftizoxime (CZX) and its clinical efficacy and side effects were evaluated. The ages of the patients ranged from 0 to 96 days, and their body weights ranged from 580 to 5,050 g. Doses given were 20-54 mg/kg every 6 to 12 hours for 2.5 to 7.5 days. Two infants with sepsis, one with urinary tract infection, one with sepsis and urinary tract infection, and 1 with fetal infection were considered to have responded satisfactorily to the CZX treatment. The drug was well tolerated and side effects was not apparent. Pharmacokinetic studies were done on CZX in 8 patients including 4 infants with very low birth weight. Their ages ranged from 2 to 91 days, and body weights from 545 to 5,050 g. Serum concentrations at 2 hours after single 20 mg/kg intravenous bolus injections were 19.2 to 44.2 micrograms/ml and the levels were 2.11 to 26.3 micrograms/ml at 8 hours. Elimination half-lives of CZX ranged 1.90 to 9.57 hours in these patients. In 2 infants with very low birth weights with ages 7 and 91 days, half-lives were as long as 9.57 and 8.24 hours, respectively. Urinary recovery in 6 hours was 31.9-66.9% in 5 patients. Urine concentrations of the drug in 24 samples collected at various time from the 7 patients ranged from 130 to 3,219 micrograms/ml. Influence of CZX on the fecal flora was studied in 1 patient given 20 mg/kg X 4/day of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

[Ceftriaxone in neonates and young infants; clinical efficacy, pharmacokinetic evaluation and effect on intestinal bacterial flora]

Twenty-two newborn and young infants, including 13 premature infants, were treated with ceftriaxone (CTRX) and the clinical efficacy and side effects were evaluated. Ages of the patients ranged from 0 to 106 days, and their body weights from 1.19 to 3.92 kg. Dose levels were 15 to 23 mg/kg every 12 to 24 hours for 2 to 13.5 days. Eighteen infants with sepsis and 1 infant with purulent coxitis were considered to have responded to the CTRX treatment. The results were excellent in 13 and good in 6 patients. The drug was well tolerated, although diarrhea occurred in 2 patients, eosinophilia in 6 patients, slightly elevated serum concentrations of transaminases in 2 patients and thrombocytosis in 1 among the 22 patients. The pharmacokinetic studies on CTRX were done in 8 patients including 3 premature infants. The ages ranged from 3 to 50 days, and body weight from 2.20 to 3.94 kg. Plasma concentrations 30 minutes after single 10 mg/kg intravenous bolus injection in two 4- to 5-day-old premature neonates were 48.4 and 50.0 micrograms/ml and those at 6 hours were 22.7 and 23.4 micrograms/ml, respectively. In 2 mature neonates, plasma levels were 42.2 and 39.1 micrograms/ml at 30 minutes and 23.4 and 26.6 micrograms/ml at 6 hours after single 20 mg/kg doses. In four 12- to 50-day-old patients, plasma concentrations ranged from 35.9 to 175.0 micrograms/ml at 30 minutes and from 21.9 to 32.8 micrograms/ml at 6 hours after multiple doses of 20 mg/kg intravenous bolus injection. The plasma half-lives of the drug ranged from 6.6 to 16.8 hours in these 8 patients. Excretion rates of this drug into urine within 12 hours were 21.4 to 63.4% in 7 patients. Urine concentrations of the drug in 34 samples collected at various times from the 7 patients ranged from 28.3 to 469.0 micrograms/ml. The cerebrospinal fluid level at 2 hours after a dose was 3.33 micrograms/ml on the 5th day of treatment in 1 patient with sepsis receiving 18 mg/kg of the drug every 12 hours. Its level at 3 hours after a dose was 6.07 micrograms/ml on the 6th day of treatment in another patient with aseptic meningitis receiving 20 mg/kg every 12 hours. The influence of CTRX on the fecal flora was studied in 3 patients receiving 20 mg/kg X 2/day. The characteristic pattern observed during the drug administration was the disappearance of Bifidobacterium and Enterobacteriaceae, the preservation of Streptococcus and Staphylococcus, and the increase in Candida.(ABSTRACT TRUNCATED AT 400 WORDS)

[Clinical and pharmacokinetic evaluation of cefotiam in neonates and young infants]

Seven neonates and young infants were treated with cefotiam (CTM) in doses ranging from 8-25.6 mg/kg every 6 to 24 hours for 1 to 14 days, and the clinical efficacy and side effects were evaluated. Among 5 infants with bacterial infections including bacteremia, perianal abscess, pneumonia, urinary tract infection and probable sepsis and meningitis, clinical responses were excellent in 1 and good in 4 patients. In the 7 patients, no side effect attributable to CTM was observed. Serum concentrations of CTM were measured in 5 patients administered with 10 to 20 mg/kg of CTM by bolus intravenous injection. Peak serum concentrations of 21.9 to 38.0 micrograms/ml were noted in samples taken at 15 minutes after injection. Serum half-lives of the drug were 2.35 hours in 2 day-old neonate, 0.72 to 0.85 hours in 3 infants of 25 to 37 days, and 8.46 hours in an 18 day-old neonate with renal insufficiency.

[A pharmacokinetic and clinical evaluation of ceftazidime in neonates and premature infants. A study of ceftazidime in the perinatal co-research group]

Ceftazidime (CAZ) was evaluated for its pharmacokinetics and clinical usefulness in neonates and premature infants. The results obtained were summarized below. Following intravenous injection of CAZ 10 or 20 mg/kg to neonates and premature infants, dose response was observed in serum concentrations ranging from 5.1 to 21.9 micrograms/ml at 6 hours after the injection. The serum half-life tended to be longer in premature infants than in neonates; the half-life being longer for an infant with lower day-age. Urinary recovery rates during the first 6 hours after single administrations of 10 mg/kg of CAZ tended to be higher in neonates than in premature infants, and higher rates were observed in older infants. However, no noticeable difference was observed after the administration of CAZ 20 mg/kg. Clinical efficacy was evaluated in 99 neonates and 55 premature infants (156 infections), daily doses ranging from 21.1 to 246.4 mg/kg. Out of 105 cases of common infections, mainly 44 cases with causative organisms identified (including 17 of sepsis, 7 of pneumonia, 4 of purulent meningitis, 11 of urinary tract infections) were examined for the clinical efficacy. The efficacy of CAZ was excellent in 21, good in 18, fair in 1 and poor in 4, with the efficacy rate of 88.6%. In the remaining 61 cases, i.e., 37 with causative organisms unknown and 24 with signs of intrauterine infections, the efficacy rate was 95.1%. Other than these cases, additional 51 cases were given CAZ solely for prophylaxis of infections, and the results were found satisfactory. On the whole, clinical efficacy rate of CAZ was 94.9% in 156 cases. Out of the 44 cases examined for bacteriological responses, 38 were evaluated as 'eradicated', 3 'persisted' and 3 'unknown' with eradication rate of 92.7%. Replacement of organisms (superinfection) was observed in 3 cases. Out of 179 cases in which adverse effects were assessable, adverse effects were observed in a total of 4 cases (2.2%), i.e., 3 cases of diarrhea (1.7%) and 1 case of rash (0.6%), and abnormal laboratory findings were observed in a total of 14 cases (7.8%), i.e., increase in eosinophiles count in 8 (4.5%), elevation of GOT in 3 (1.7%), increase in platelet, elevation of GOT . GPT, and elevation of GOT . GPT . BUN in 1 case each (0.6%). None of them were severe and they were transient. Elevations of bilirubin and cases of positive PIVKA II associated with CAZ were not observed.(ABSTRACT TRUNCATED AT 400 WORDS)

[Clinical and pharmacokinetic evaluation of ceftazidime in neonates and young infants]

Seventeen newborn and young infants including 6 premature infants were treated with ceftazidime (CAZ) and the clinical efficacy and side effects were evaluated. Ages of the patients ranged from zero to 55 days, and their body weights ranged from 1.35 to 3.87 kg. Doses of CAZ ranged 10-50 mg/kg every 6 to 12 hours for 3 to 14 days. Twelve infants with infections including meningitis, sepsis, pneumonia and urinary tract infections, were considered to have responded to the CAZ treatment. Among them, results were excellent in 2, good in 9 and fair in 1 patient. The drug was well tolerated, but 1 had diarrhea and 3 patients had eosinophilia among the 17 patients. The pharmacokinetics of CAZ was studied in 22 patients including 11 premature infants. Their ages ranged from 1 to 60 days, and body weights ranged from 0.85 to 3.96 kg. Serum concentrations in 7 patients ranged from 24.2-38.5 micrograms/ml at 30 minutes after single doses of 10 mg/kg intravenous bolus injections and 4.36-12.4 micrograms/ml at 6 hours. Mean elimination half-lives of the drug were 3.20 hours in 2 patients under 7 days of age and 2.31 hours in 5 patients from 7 days of age or older. In 8 patients, serum concentrations ranged 32.6-57.9 micrograms/ml at 30 minutes and 8.10-20.7 micrograms/ml at 6 hours after single doses of 20 mg/kg. Elimination half-lives were 3.53 hours in 4 patients under 7 days of age and 2.79 hours in 4 patients from 7 days of age or older.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasonographic diagnosis of uriniferous perirenal pseudocyst

A child with a traumatic uriniferous perirenal pseudocyst was presented. The diagnosis was not made by routine radiological studies, but ultrasound examination demonstrated a perirenal fluid accumulation clearly. The usefulness of the ultrasound examination in the diagnosis of this condition was emphasized. The characteristic finding in ultrasonogram consists of a hydronephrotic kidney and its invagination into the echolucent mass. When perirenal cystic lesions are demonstrated by ultrasound, the junctional zone between the cyst and kidney should be carefully checked for signs of invagination of the kidney into the cyst.