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Biomedical subjects

S Iwata

Publications and source records attributed to S Iwata.

At least 271 records · Page 15Linked to original sources
PubMed1991

[Bacteriological and clinical studies of cefodizime in pediatrics].

Bacteriological and clinical studies on cefodizime (CDZM, THR-221), a new cephem developed by Hoechst AG and Roussel Uclaf, were carried out and the results are summarized below: 1. Against Gram-positive bacteria, Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae, antibacterial activities of CDZM were similar to those of cefotaxime (CTX), cefazolin, cefotiam and piperacillin. Against Escherichia coli, Klebsiella pneumoniae and Serratia sp., antibacterial activities of CDZM were similar to that of CTX, and superior to those of other tested antibiotics. Especially against Haemophilus influenzae and Branhamella catarrhalis, it showed an excellent antibacterial activity. 2. Although the clinical efficacy was poor in 1 patient with sepsis caused by Salmonella marcescens and in another with cervical lymphadenitis, in 5 patients with upper respiratory tract infection, 4 patients with bronchitis, 6 patients with bronchopneumonia, 18 patients with pneumonia, 5 patients with urinary tract infection and 1 patient with enteritis, the clinical efficacy was excellent or good and the efficacy rate was 95.1% (39/41) including excellent efficacies in 25 cases. 3. Bacteriologically, all identified causative bacteria were eradicated except for 1 case of Salmonella sp., thus the eradication rate was 97.4% (38/39). Especially S. pneumoniae in 10 cases, H. influenzae in 12 cases and B. catarrhalis in 3 cases were eradicated totally. 4. Adverse reactions were studied in 46 cases, and digestive symptoms were observed in 9 cases (diarrhea 5 cases, loose stools 4 cases). Eruption and vascular pain were observed in 1 case each. As digestive symptoms in 9 cases were mild, the treatment were not suspended. In laboratory test values, elevation of GOT, elevation of GPT, elevation of bilirubin, and eosinophilia were observed in 1 case each. Influences on blood coagulation parameters were studied. No change was observed between the beginning and the end of the treatment. From above results, we have concluded that CDZM is a useful and safe antibiotic in pediatrics, administered at a daily dose of 20 mg/kg divided into 3 or 4 doses and administered intravenously.

Adolescent↗
PubMed1991

[Influence of cefodizime on intestinal bacterial flora].

Effects of cefodizime (CDZM), a new injectable cephem antibiotic, on the intestinal bacterial flora were studied in tetra-contaminated mice and in pediatric patients. CDZM was intramuscularly administered at a dose of 100 mg/kg once a day for 5 consecutive days to mice contaminated with 4 different species of organisms: Escherichia coli, Enterococcus faecalis, Bacteroides fragilis and Bifidobacterium breve. For 3 species except E. faecalis, bacterial populations in feces were markedly reduced after the start of the treatment. Subjects in the pediatric study were 5 children with bacterial infections (4 boys and 1 girl) at ages from 7 months to 9 years 6 months and with their body weights ranging from 7.6 kg to 51.1 kg. CDZM was intravenously administered at a dose of 9.7 mg/kg to 23.0 mg/kg 4 times a day for 5 to 15 days. Although some variations in the fecal bacterial flora were noticed among these subjects during the treatment, populations of main aerobes and anaerobes such as Enterobacteriaceae, Enterococcus, Bacteroides, Bifidobacterium and Eubacterium decreased markedly in most cases. Glucose non-fermenting Gram-negative rods and fungi tended to increase during or after the administration of CDZM, and they were the most predominant species in some cases. Although these changes tended to return to predosing states after the cessation of the treatment with CDZM, attention must be paid to possible occurrences of diarrhea, superinfection or bleeding tendency when treatment with the drug is continued for long periods of time. Fecal concentrations of CDZM considered to be closely related to the changes of the intestinal bacterial flora showed pretty high values in all cases.

Animals↗
PubMed1991

[A new criterion for hCG administration in human IVF programs: importance of serum LH levels].

A new, simple criterion for hCG administration to induce ovulation for IVF is described. Serum LH levels were measured daily, and hCG was administered, independent of follicle size or estradiol levels, the night of the day when the LH level first exceeded the J level, defined as the minimum value + (the day 3 value-the minimum value) x 1/3. Based on this hCG criterion, the total and ongoing pregnancy percentages per cycle were 35% and 27%, respectively. It appears that the pregnancy rate decreases when hCG is administered one day before or one day after the criterion is met. Pregnancies resulting from hCG administration based on the criterion had a wide range both of dominant follicle diameter (14-21 mm) and estradiol level (229-2,050 pg/ml). The serum LH level is recommended as a useful parameter in timing hCG administration for IVF.

Chorionic Gonadotropin↗
PubMed1991

Crystallization of allosteric L-lactate dehydrogenase from Thermus caldophilus and preliminary crystallographic data.

L-Lactate dehydrogenase of Thermus caldophilus GK24 was purified from Escherichia coli containing an overexpression plasmid. The enzyme was crystallized from polyethylene glycol 6000 solutions without ligands by the hanging drop vapor diffusion method. Two forms of crystals were obtained. The crystals grown at pH 6.0 were characterized by means of an X-ray diffraction experiment, while those grown at pH 6.5 and 7.0 did not give detectable diffraction spots. The crystals grown at pH 6.0 belonged to monoclinic space group P2(1), the cell dimensions being a = 54.8 A, b = 138.2A, c = 86.1 A, and beta = 93.3 degrees. These crystals diffract to beyond 2.5 A spacing and are stable on X-ray irradiation.

Allosteric Regulation↗
PubMed1991

[The influence of cefpirome on intestinal bacterial flora].

Cefpirome (CPR, HR810), a new parenteral cephalosporin antibiotic, was studied for its effect on the intestinal bacterial flora in pediatric patients. The subjects were children admitted for infections (6 males and 3 females, 1 month to 5 years 1 month old, weighted 3.94 to 21.0 kg). CPR was intravenously administered at a dose between 19.0 to 40.0 mg/kg, 3 to 4 doses daily over 6 to 12 days. The feces from these children were collected before, during, and after administration, and bacteria were identified and counted. CPR concentration, beta-lactamase activity, and Clostridium difficile D-1 antigen were also assayed. Bacterial flora changes in feces during CPR administration showed some variance, but generally 5 cases out of the 9 showed a significant decrease in Enterobacteriaceae and Enterococcus faecalis among aerobic bacteria. The other 4 cases showed some transient decrease, but no significant change was observed. No significant changes were recognized for Enterococcus avium and Enterococcus faecium, and the total aerobic bacterial count decreased in a transient manner in only one patient. Regarding anaerobic bacteria, Bifidobacterium and Eubactrium revealed a significant decrease, a transient decrease or no change from case to case. Bacteroides showed little change in count. Consequently, the total anaerobic bacteria count did not reveal a large change aside from 1 case in which Bacteroides was not detected before administration and a significant decrease of other bacteria was noted. In no case, glucose nonfermentative Gram-negative bacilli or fungi were found dominant. Although C. difficile and C. difficile D-1 antigen were detected in 3 and 4 cases, respectively, there was no exact relationship between the number of C. difficile and the characteristics of the feces. CPR was detected in fecal samples from 6 cases during administration with concentrations ranging between 1.20 to 22.4 micrograms/g. High values of CPR tended to be found in specimens with low beta-lactamase activity in the feces. When drug sensitivities of the bacteria isolated from feces before and after administration were compared, higher levels of resistance were found in some bacteria such as Enterococci and Bacteroides during or after administration than before administration. The above results suggest that CPR is a drug with a relatively small influence on the intestinal bacterial flora in children, but a particular attention is required for diarrhea and microbial replacement during a continuous, long-term administration of the drug.

Bacteria↗
PubMed1991

[Pharmacokinetic and clinical studies on cefpirome in pediatrics].

Cefpirome (CPR, HR 810), a new parenteral cephalosporin antibiotic, was studied for its pharmacokinetics, bacteriological and clinical effects in the field of pediatrics. 1. CPR was very active against Staphylococcus aureus, Staphylococcus epidermidis, Coagulase-negative staphylococci, Streptococcus pneumoniae among Gram-positive cocci. Antibacterial activities of CPR were also strong against Branhamella catarrhalis, Haemophilus influenzae, Escherichia coli, Salmonella sp., Klebsiella oxytoca, Enterobacter cloacae, Pseudomonas aeruginosa among Gram-negative rods. 2. The plasma concentration 15 minutes after a bolus intravenous injection of 20 mg/kg was 80.4 micrograms/ml, and the T 1/2 (beta) was 1.03 hours. Plasma concentrations after intravenous drip infusion over 30 minutes of 20 mg/kg and 25 mg/kg were 48.3 and 117 micrograms/ml at the end of infusion, and T 1/2 (beta) for these dosage were 1.14 and 1.45 hours. 3. The urinary recovery rates over 6 hours after administration were 45.2-63.9% for CPR. 4. Clinical efficacies of CPR were excellent in 31 patients and good in 30 patients with an efficacy rate of 98.4%. In bacteriological examinations, causative organisms were eradicated with an eradication rate of 95.7%. 5. As side effects, diarrhea was observed in 5 patients and loose stool in 1 patient with an incidence of 8.2%. Abnormal values were found in some patients in clinical laboratory tests for eosinophilia, thrombocytosis and an elevation of GOT, GPT and triglyceride. These findings indicate that CPR will be useful against bacterial infections in pediatrics.

Adolescent↗
PubMed1990

Impaired polymorphonuclear leucocyte function in patients undergoing hepatectomy: adenylate energy charge and superoxide anion production in relation to hepatic mitochondrial redox state.

Patients undergoing hepatectomy have an increased susceptibility to infection. We therefore studied the energy metabolism of the polymorphonuclear leucocyte (PMN), focusing on energy charge and function, especially superoxide anion (O2-) generation, in relation to the hepatic mitochondrial redox state. By labelling the PMN adenine nucleotide pool with radioactive adenine and by superoxide dismutase-inhibitable reduction of ferricytochrome c, the energy charge and O2- production was measured in 18 patients with hepatoma (non-cirrhotic, seven; cirrhotic, 11) undergoing hepatectomy. Their arterial ketone body ratios (KBRs), reflecting the hepatic mitochondrial redox potential, were above 0.7 before operation. After surgery, the 18 patients were divided into two groups: group A, KBR greater than 0.7, n = 10; and group B, KBR less than 0.7, n = 8. The energy charge and O2- release in group B decreased significantly from preoperative values (P less than 0.001 and P less than 0.01 respectively) and when compared with group A (P less than 0.05 and P less than 0.01 respectively). These results suggest that impaired hepatic energy metabolism (KBR less than 0.7) in hepatectomized patients leads to impaired energy charge and O2- production in the PMNs.

Adenine Nucleotides↗
PubMed1990

The influence of the normal turbinate mucosa on nasal airflow.

In an attempt to determine the influence of the turbinate mucosa on nasal airflow resistance, we measured the nasal resistances in seven patients who had no lateral walls on one side of their nasal cavities because of unilateral operative removal of maxillary tumors. We compared resistances on the operated side with the normal unoperated side. No significant differences were found either on inspiration or expiration. Additionally, no significant influence of the turbinate mucosa on nasal airflow resistance was detected in sitting subjects.

Adult↗
PubMed1990

Hormonal stimulation of tyrosinase activity in human foreskin organ cultures.

A human foreskin organ culture system has been developed to study the response of human skin to hormonal stimulation. Foreskins are maintained in culture on floating plastic supports which allows the epidermal surface to be exposed to air while the dermis is bathed in nutrient medium. Both black and white human foreskins can be maintained in organ culture for at least 1 wk with no change in the tissue structure or cell viability as determined by histochemical staining and by dopa reaction staining. Tyrosinase activity in both black and white human foreskin cultures decays markedly during the first 2 d of culture to a new steady state level which remains stable throughout the culture period. Both black and white foreskin cultures consistently demonstrate 2- to 10-fold increases in tyrosinase activity when treated with theophylline (1 mM). Approximately 90% of all skin cultures examined showed an increase in enzyme activity when treated with this phosphodiesterase inhibitor. Dibutyryl cAMP (0.1 mM) and [Nle4, D-phe7]-alpha MSH (10(-8) M), were also found to markedly stimulate tyrosinase activity in some skin cultures, whereas alpha-MSH and prostaglandin E1 produced only an inconsistent and small increase in the activity of the enzyme. Histamine (1 microM), vitamin D3 (1 microM), and retinoic acid (1 microM) failed to stimulate tyrosinase activity in either white or black foreskin cultures. This hormone-responsive organ culture system can be utilized to characterize the molecular processes responsible for the regulation of tyrosinase and pigmentation in human skin.

Alprostadil↗
PubMed1990

Role of ATL-derived factor (ADF) in the normal and abnormal cellular activation: involvement of dithiol related reduction.

HTLV-I transformed T cells not only express a large number of interleukin-2 receptors (IL-2R/p55(Tac], but also produce an IL-2R/Tac inducer named ATL-derived factor (ADF). We have cloned the ADF cDNA and found that ADF production in human lymphocytes can be enhanced by cellular activators such as mitogens or phorbol esters. Recombinant ADF produced by E. coli was shown to have growth-promoting activity in combination with interleukin-2 or suboptimal mitogenic stimuli on several lymphoid cells including human PBMCs, besides the originally reported IL-2R/Tac inducing activity. Homology analysis revealed an unexpected structural relationship between ADF and dithiol-reducing enzyme, thioredoxin, which had been characterized originally in prokaryotic system. Recombinant ADF also has a reducing activity, suggesting the presence of still unknown features of ADF action in vivo. The requirement of dithiol reduction in the biological activities of ADF, together with the possible involvement of ADF production in the normal and abnormal activation of human cells are discussed.

Amino Acid Sequence↗
PubMed1990

The relationship between tyrosinase activity and skin color in human foreskins.

Tyrosinase activity was assayed in black and white human foreskin samples by measuring both the hydroxylation of tyrosine to dopa (tyrosine hydroxylase activity) and the conversion of [14C]tyrosine to [14C]melanin (melanin synthesis assay). Enzyme activity was found both in the particulate (75%) and soluble (25%) fractions of the cell. Membrane-bound tyrosinase was readily solubilized by either zwitter-ionic or nonionic detergents. The anionic detergent, sodium cholate, inhibited enzyme activity. Tyrosinase activity in black foreskin homogenates averaged almost three times that in white skin samples (33.8 pmols 3H2O/h/mg skin in black and 12.71 pmoles 3H2O/h/mg skin in white skin), although considerable overlap in activities existed among the two groups. Tyrosinase activities measured with two separate assays, tyrosine hydroxylase and [14C]melanin assays, were similar, suggesting that tyrosine hydroxylase activity is tightly coupled to melanin synthesis. Tyrosinase activity determined by either assay method generally correlated with skin melanin content. Kinetic analysis of tyrosinase from black and white foreskin revealed a Km for tyrosine of 2.5 X 10(-4) M in both skin types. Immunotitration experiments suggested that the difference in tyrosinase activities between white and black skin may be due, not only to different amounts of enzyme present in the melanocytes, but also possibly to differences in the catalytic activities of the enzyme found in melanocytes of black and white skin.

Black People↗
PubMed1990

[The influence of face masks and a nasal nozzle on nasal airflow].

In an attempt to detect the influence of various kinds of face masks and a nasal nozzle on nasal airflow, we made measurements of nasal resistance by a head-out body plethysmograph with or without the masks on the face or the nozzle to the nostril of the normal adult subjects. The mean values of nasal resistance with the masks differed from the mean values without the masks significantly. No significant difference between values with and without the nozzle was found. The coefficient variations of 40 consecutive measurements of nasal resistance with the masks or the nozzle had wider ranges than those without the apparatuses. But the variation due to the nozzle was the minimum in the apparatuses.

Adult↗
PubMed1990

[Serum concentration of laminin in transitional cell carcinoma].

The concentration of laminin in the serum was determined for 45 patients with urinary tract transitional cell carcinoma, and the clinical significance of the findings was considered. The difference between the serum laminin concentrations in the control group and the transitional cell carcinoma patient group was not statistically significant, but the serum laminin level was highest in the transitional cell carcinoma patients with metastatic foci. In many of the patients who had metastatic foci and showed clearly progressive disease, the serum laminin concentration was found to increase with the passage of time. When the transitional cell carcinoma tissues were stained by the fluorescent antibody technique, there was little distribution of laminin in the tumor tissues, contrary to our earlier-reported findings regarding the staining of laminin in renal cell carcinoma tissues. In renal cell carcinoma patients, the serum concentration of laminin had been found to be high even when there were no metastatic foci, and consideration of this fact strongly suggests the possibility that the mechanism for laminin synthesis in urinary tract transitional cell carcinoma is different from that in renal cell carcinoma. It was surmised that the serum laminin concentration has potential for use as a diagnostic indicator of metastasis in patients with urinary tract transitional cell carcinoma.

Carcinoma, Transitional Cell↗
PubMed1990

[A clinical study on cefdinir in pediatrics].

Clinical evaluations of cefdinir (CFDN, FK482) were carried out. The obtained results are summarized as follows. 1. Clinical responses to CFDN of 43 patients with pediatric infections were excellent in 23, good in 15, fair in 4 and poor in 1. The overall efficacy rate was 88%. 2. Bacteriologically, the eradication rate for 34 isolates presumed to be pathogens was evaluated and the eradication rate was 85.3%. 3. Side effects observed were diarrhea in 4 of 48 patients. The incidence was 8.3%. Abnormal laboratory findings were an elevation of GOT, an elevation of eosinophils and an increase in platelet counts. The results suggested that CFDN might be a very useful and safe drug for the treatment of pediatric infections.

Administration, Oral↗
PubMed1990

[Allergic individuals to Japanese cedar or orchard grass consist of two subgroups based on the sensitization to Dermatophagoides pteronyssinus].

One hundred and twenty-six allergic subjects were divided into three groups based on the RAST results for Dermatophagoides pteronyssinus (D.p) and Japanese cedar (J.C.). We compared sex, age of examination for RAST, serum IgE, family history of allergic diseases, prevalence rate of bronchial asthma (BA) and allergic rhinitis (AR), and onset of AR among three groups. No significant difference in the other variables except serum IgE and prevalence rate of BA was found between the group with D.p-positive and J.C.-positive RAST and the group with D.p-positive and J.C.-negative RAST. The group with positive RAST for D.p and J.C. showed lower age of the examination, higher serum IgE, higher incidence of allergic family history, higher prevalence rate of BA, and lower onset age of AR than the group with negative RAST for D.p and positive RAST for J.C. We suggested that in J.C. RAST-positive group there might be two different subgroups distinguished by RAST result for D.p Similar results were obtained from the assessment of RAST for Orchard grass instead of J.C.

Adolescent↗
PubMed1990

Anaphylaxis to grand keyhole limpet (abalone-like shellfish) and abalone.

We report five patients who developed moderate to severe anaphylactic reactions induced by the ingestion of grand keyhole limpet (GKL) and abalone. Specific IgE-mediated hypersensitivity to these shellfish was demonstrated by history, prick skin test, and RAST. RAST inhibition technique revealed the cross-antigenicity between GKL, abalone, and keyhole limpet hemocyanin.

Adult↗
PubMed1990

[Antibacterial activity of norfloxacin on methicillin-resistant Staphylococcus aureus. Comparison with oral antibacterial agents].

Minimum inhibitory concentrations (MIC) of norfloxacin (NFLX) to 133 strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from clinical patients were investigated and compared with those of minocycline (MINO), erythromycin (EM), amoxicillin (AMPC), cefaclor (CCL) and fosfomycin (FOM). MIC90 of these drugs were 3.13 micrograms/ml with NFLX, 0.39 micrograms/ml with MINO, greater than 100 micrograms/ml with EM, 50 micrograms/ml with AMPC, greater than 100 micrograms/ml with CCL and greater than 100 micrograms/ml with CCL and greater than 100 micrograms/ml with FOM. MIC distribution patterns with 2 peaks were recognized with EM and FOM. Of 55 strains resistant to all of EM, AMPC, CCL and FOM, 50 and 54 strains were well susceptible to NFLX and MINO, respectively. The present investigation demonstrated relatively potent antibiotic effect of NFLX against MRSA. Considering the safety of NFLX to children which have been confirmed and reported separately, it can be concluded that NFLX is a useful oral antimicrobial drug in the treatment of children with MRSA infections.

Administration, Oral↗