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Biomedical subjects

T Koga

Publications and source records attributed to T Koga.

At least 541 records · Page 30Linked to original sources
PubMed1988

Purification and immunochemical studies of type b carbohydrate antigen of oral Streptococcus milleri.

The type-specific antigen of serotype b Streptococcus milleri was extracted with trichloroacetic acid from a purified cell wall preparation of the strain NCTC 10708 and then purified on a DEAE-Sephadex A-25 column, followed by a Sephadex G-100 column. The antigen was composed of rhamnose and glucose in a molar ratio of 1.7:1.0, with a trace of galactosamine (0.1). The quantitative precipitin inhibition test with various haptenic sugars showed that rhamnose gave the greatest inhibition, whereas glucose and its related carbohydrates were less effective. The major carbohydrate components of the Rantz-Randall extracts from cells of all four serotype b strains tested were also rhamnose and glucose. These results suggest that rhamnose is structurally involved in the immunodeterminant of the serotype b-specific antigen of oral S. milleri.

Amino Sugars↗
PubMed1988

Central and peripheral mechanisms of the enhanced hypertension following long-term salt loading in spontaneously hypertensive rats.

We evaluated whether or not increased sodium (Na) concentrations of cerebrospinal fluid (CSF) and stimulated activities of brain renin-angiotensin system (RAS) contribute to an enhanced hypertension by salt overload in spontaneously hypertensive rats (SHR). Long-term salt loading (1% NaCl solution as drinking fluid) accelerated the development of hypertension in SHR, but did not alter the blood pressure (BP) in normotensive Wistar-Kyoto rats (WKY). CSF Na concentration was elevated in uninephrectomized (Nx) group as compared to that in control SHR, while in WKY CSF Na was not influenced by the treatment. A fall in BP by intravenous AVP antagonist or hexamethonium was greater in salt-loaded SHR than in controls. This hypotensive response to the combined blockade of AVP and SNS correlated with CSF Na in SHR but not in WKY. Plasma concentration of AVP and epinephrine tended to increase in relation to the degree of salt loading in SHR but not in WKY. Pressor responses to intracerebroventricular (ICV) angiotensin II (AII) and NaCl were greater in SHR than in WKY, although these responses were not influenced by chronic salt load in either SHR or WKY. The enhanced hypertensive action of ICV NaCl in SHR was abolished by pretreatment with ICV AII antagonist. Chronic saline drinking enhanced the depressor effect of ICV captopril in SHR but not in WKY. These observations suggest that salt overload in SHR may cause an elevated CSF Na concentration and an enhanced activity of brain RAS, which may increase activity of SNS and release of AVP, resulting in an enhanced development of hypertension.

Animals↗
PubMed1988

Epitope specificity of antibody response against human type II collagen in the mouse susceptible to collagen-induced arthritis and patients with rheumatoid arthritis.

The presence of species-specific and species-non-specific (common) epitopes has been demonstrated on type II collagen (CII) using monoclonal antibodies. In this study, we investigated the role of antibody response to some species-specific and common epitopes in mice immunized with human CII for the induction of collagen-induced arthritis (CIA). Antibody responses to species-specific epitopes in arthritic mice appeared significantly higher than that in non-arthritic mice. However, no significant difference of antibody responses to common epitopes was found between arthritic and non-arthritic mice. Monoclonal antibody reactive with one of the common epitopes exhibited the ability to induce arthritis in mice previously given the primary injection of CII, indicating the involvement of this epitope in the induction of CIA. Finally, we investigated the epitope specificity of anti-human CII antibody present in serum samples of patients with rheumatoid arthritis and relapsing polychondritis, and found antibodies to some common epitopes.

Animals↗
PubMed1988

[Microbiological, pharmacokinetic and clinical studies of rokitamycin dry syrup in the pediatric field].

Rokitamycin (RKM), a newly developed macrolide antibiotic with a 16-membered ring, dissolves well under acidic conditions. It has been improved over other macrolides to minimize individual variations in its absorbability. We measured, using the GA-test, variations in gastric acidities of 43 children with ages between 1 to 14 years, and investigated the relationship between gastric acidities and pharmacokinetic values. Also activities (expressed in MICs) of antimicrobial agents were studied against clinically isolated 229 bacterial strains using an inoculum size of 10(6) cells/ml. Tested organisms included Streptococcus pyogenes (77 strains), Streptococcus agalactiae (29), Streptococcus pneumoniae (2), as Gram-positive cocci, and Haemophilus influenzae (1), Haemophilus parainfluenzae (1), Bordetella pertussis (12), Salmonella sp. (4) and Campylobacter jejuni (103) as Gram-negative bacilli. Against stock strains of bacteria, MICs of 10 drugs (RKM, erythromycin (EM), josamycin (JM), midecamycin (MDM), midecamycin acetate (MOM), clindamycin (CLDM), amoxicillin (AMPC), cefaclor (CCL), minocycline, ofloxacin (OFLX] were determined. Against isolates from patients who underwent treatment with RKM, MICs of only 4 drugs (RKM, EM, JM, MOM) were determined. Measurements were made on plasma and urinary concentrations of RKM and its urinary recovery rates after patients including 6 boys with ages between 5 years 1 month and 11 years 6 months were administered with RKM (dry syrup). Two groups of 6 boys were administered between meals with RKM at dose levels of 5 and 10 mg/kg, respectively. Clinical and bacteriological effects of RKM were evaluated for 175 patients including 5 cases of pharyngitis, 3 tonsillitis, 32 pneumonia, 17 mycoplasmal pneumonia, 34 atypical pneumonia, 28 streptococcal infections, 29 Campylobacter enteritis, 4 Salmonella gastroenteritis, and 23 enteritis due to unknown organisms. Five drop-out cases were excluded from the evaluations. In the evaluable cases, an average dose level used was 31.8 mg/kg/day, with a daily dose divided into 3 to 4 administrations and with an average treatment duration of 9 days. Adverse reactions of RKM and its effects on laboratory test values were investigated in these patients including the drop out cases. Obtained results of these studies are summarized below. 1. The GA-test produced pH values indicating that amounts of gastric acid were mostly either normal or high in 42 of the 43 subjects tested (97.7%), and only one low acid case (2.3%) was observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗
PubMed1988

[Pharmacokinetic, bacteriological and clinical studies of ceftizoxime in neonates and low birth weight infants].

Ceftizoxime (CZX), one of the fifth group in cephem-antibiotics classified by Fujii, was administrated intravenously with a one shot dose of 20 mg/kg to neonates and low birth weight infants with ages ranged 4-21 day old and plasma and urinary concentrations and urinary recovery rates of the drug were determined. Clinical, prophylactic and bacteriological effects of CZX were evaluated and adverse reactions and effects on laboratory test values due to this drug were studied in 22 neonates and low birth weight infants (0-76 day old) consisting of 16 cases with various bacterial infections including presumptive cases of bacterial infections and 6 cases with prophylactic administration against infectious diseases. An average CZX daily dose of 55.3 mg/kg was given once or divided into 2-4 times daily (twice: 16 cases, 3 times: 3 cases, 4 times: 2 cases) through intravenous one shot administration for 6 days on the average. The results obtained are summarized as follows. 1. Neonates and low birth weight infants were classified into 3 groups by age: 4-7, 8-14, 15-21 day old. Plasma peak levels of CZX were observed at an average of 5 minutes after administration in all 3 groups with mean values of 58.3, 74.9 and 76.9 micrograms/ml, respectively, and the 4-7 day old-group showed a lower value than with other 2 groups. Mean values of AUC were 218.9, 221.0 and 197.0 micrograms.hr/ml, respectively, and no notable difference was observed within each group. Mean values of half-lives of CZX were 3.61, 2.72 and 2.37 hours, respectively, and the younger group tended to have the longer value. 2. Urinary concentrations of CZX ranged 10.9-1.190 micrograms/ml in all of the 3 groups during 0-2, 2-4, 4-6, 6-8 hours after administration. Mean values of urinary recovery rates during 8 hours of the 3 age-groups were 60.1, 68.7, 56.7%, respectively. The oldest group showed the lowest mean value because one of the cases had the lowest value of 34.5% for an unknown reason. 3. Clinical effect of CZX in 16 cases with various bacterial infections and presumptive bacterial infections was evaluated with an efficacy rate of 87.5%. The prophylactic effect was recognized in all 6 cases that were given CZX to prevent infectious diseases. 4. The bacteriological effect was evaluated in only one case with an infection due to Escherichia coli, which was eradicated by the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗
PubMed1988

Immunocytochemical discovery of the 22- to 23-Kd subunit of cytochrome b558 at the surface of human peripheral phagocytes.

A monoclonal antibody raised against cytochrome b558 reacted specifically with the 22- to 23-Kd protein, the small subunit of this cytochrome. Cytochemical studies showed that the epitope was located on the surfaces of human neutrophils and monocytes. The small subunit of cytochrome b558, therefore, was expressed at least in part on the outer surface of these cells.

Antibodies, Monoclonal↗
PubMed1988

[Clinical studies of rokitamycin dry syrup on Chlamydia trachomatis infections in the neonate and infant].

A dry syrup preparation for infants and children of a newly developed 16-membered macrolide antibiotic, rokitamycin, was administered to 5 neonates and low birth weight infants of 6 to 25 days after births at a dose level of 10 mg/kg on an empty stomach then plasma drug levels were determined. The dry syrup preparation was also given to a total of 19 Chlamydia trachomatis infection cases of 7 days to 8 months old neonates, low birth weight infants and infants including 12 cases of pneumonia, 2 cases of conjunctivitis and 5 non-symptomatic carriers at an average daily dose level of 48.1 mg/kg in 2 to 4 doses for an average of 19 days and its clinical effects, bacteriological effectiveness, side effects and effects on laboratory test values were examined. The obtained results are summarized as follows. 1. Because the test subjects were neonates and premature infants, obtainable amounts of blood samples were limited, thus it was not possible to determine time courses of plasma drug levels to reach their peaks. Peak plasma levels, however, were speculated to be similar to those in children. Plasma half-lives of the drug were also not determinable, but they seemed to be somewhat longer than those in children. 2. Clinical efficacies were determinable in the 2 cases of conjunctivitis and 10 of the 12 cases of pneumonia, with excellent or good results in both cases of the former and with excellent or good results in 9 of the 10 determinable cases of the latter. Thus, the overall efficacy rate was high, 91.7%. 3. Bacteriological efficacies were determinable in 18 cases including non-symptomatic carriers. C. trachomatis was eradicated in 16 of the cases with an overall efficacy rate of 88.9%. 4. Diarrhea was observed in 2 cases, which were suspected as side effects of the drug. 5. No abnormalities were observed in the laboratory test results. Judging from the above results, this drug appears to be useful for the treatment of C. trachomatis infections of neonates, low birth weight infants and infants.

Chlamydia Infections↗
PubMed1988

[Clinical studies of rokitamycin dry syrup on skin and soft tissue infections in the pediatric fields].

Rokitamycin (RKM) dry syrup, a newly developed macrolide antibiotic, was administered to children with ages between 6 months and 15 years and 10 months suffering from skin and soft tissue infections including 41 cases of impetigo, one case of staphylococcal scalded skin syndrome (SSSS) and 2 cases of subcutaneous abscess totalling 44 cases. The average daily dose level used was 31.3 mg/kg divided into 3 or 4 doses, for an average of 6 days of treatment. MICs of 4 different macrolide antibiotics including RKM, erythromycin (EM), josamycin (JM) and midecamycin acetate (MDM acetate) were determined against 32 bacterial strains isolated from these cases including 30 strains of Staphylococcus aureus and 2 strains of Streptococcus pyogenes. The inoculum level used was 10(6) cells/ml. Among these strains of bacteria, 20 strains of S. aureus and 1 strain of S. pyogenes were also used, at the same inoculum size, for the determination of MICs of 4 beta-lactam antibiotics including 3 different penicillins such as ampicillin (ABPC), methicillin (DMPPC) and cloxacillin (MCIPC) and cefaclor (CCL), a cephem antibiotic. RKM was then evaluated through the above treatment for its clinical efficacy, bacteriological effects, side effects and effects on laboratory test values. Obtained results are summarized as follows. 1. Activities of drugs tested were compared to each other. MIC90 of RKM against S. aureus averaged 0.39 microgram/ml, and against no strains of S. aureus showed MIC values of higher than 25 micrograms/ml, thus, the antibacterial activity of RKM against S. aureus was the highest among the 8 drugs tested. The activity of MCIPC was next highest followed by that of DMPPC, MIC determination was done on only 2 strains, or, for some drugs, only one strain, of S. pyogenes, and RKM showed activities somewhat lower than ABPC and EM, and similar to JM and CCL within the limited testing. 2. Clinical efficacies of RKM determined by doctors in charge were 97.6% in the 41 cases of impetigo, with good or excellent efficacies were observed, 100% in the single case of SSSS and the 2 cases of subcutaneous abscess. Thus an overall efficacy on the 44 cases was rated very high, at 97.7%. 3. Clinical efficacy rating according to accumulated scores was determinable in 37 cases including all the 3 diseases on the third day of treatment with an efficacy rate of 89.2%. Ratings were determinable on the fifth and the seventh days of treatment in 24 and 21 cases, respectively, with all the cases judged good or excellent.(ABSTRACT TRUNCATED AT 400 WORDS)

Abscess↗
PubMed1988

[Pharmacokinetic and clinical studies of sultamicillin granule in the pediatric field].

Sultamicillin (SBTPC) is a combined drug of ampicillin (ABPC) and sulbactam (SBT) which is an inhibitor of beta-lactamase, in a clinical form of tosylate with equivalent molecules in ester linkages. A tablet form of this combined drug has been released since July, 1987 in Japan and now a granular form for pediatric patients has been developed. Hence, the granular form of SBTPC was administered to 6 boys (age: 8 years 5 months-11 years 5 months) to determine plasma and urinary concentrations of the drug and its urinary recovery-rates. The dose of 10 mg/kg or 15 mg/kg was given orally just after meal to 3 boys. To study clinical and bacteriological effects of this drug, a mean daily dose of 27.1 mg/kg divided 2-4 times a day was administered for 9 days on the average to a total of 57 cases with pharyngitis (5), tonsillitis (5), laryngitis (1), bronchitis (1), pneumonia (8), scarlet fever (1), typhoid fever (1), impetigo (16), furuncle (2), abscess (6), lymphadenitis (1) and urinary tract infection (10) except 2 cases which were unevaluable for clinical effects. MICs of 7 drugs (SBTPC, ABPC, SBT, methicillin (DMPPC), cloxacillin (MCIPC), cephalexin and cefaclor) against 12 of 22 strains isolated from patients with infections of skin and soft tissue were determined with inoculum-sizes of 10(8) and 10(8) CFU/ml to study beta-lactamase producing activities. Adverse reactions and abnormal effects on laboratory test values attributable to this drug were studied in patients including dropped-out cases. The results obtained are summarized as follows. 1. Mean plasma peak levels of ABPC and SBT were observed at 1 hour after administration in both of the 10 mg/kg and the 15 mg/kg groups with values of 2.34 and 5.57 micrograms/ml for ABPC and 1.87 and 4.66 micrograms/ml for SBT, respectively. Mean concentrations of SBT were lower than those of ABPC in both groups and individuals. Dose-responses in plasma levels and AUCs were observed in both groups. Mean half-life values of ABPC and SBT in the 2 groups were 1.93 and 1.12 hours for ABPC and 1.97 and 1.22 for SBT, respectively. Mean half-life values for ABPC and SBT were similar in each group and this tendency was also seen among individuals.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

Protective immunity to Listeria monocytogenes in neonatally thymectomized (NTx) mice: involvement of T cells distinct from those in sham-thymectomized mice.

Neonatally thymectomized (NTx) mice, whose ability to mount antigen-specific cell-mediated immunity is reported to be generally defective, were found to be capable of mounting a normal level of acquired cellular resistance (ACR) and delayed footpad reaction (DFR) to Listeria monocytogenes. The present study was done in order to determine the functional differences of T cells contributing to the protection against L. monocytogenes between NTx and sham-operated mice. In mice immunized with viable L. monocytogenes, the absolute number of splenic T cells was significantly lower in NTx mice compared with sham-operated mice. When the ability of immune T cells to transfer ACR and DFR was examined by passive transfer, lymphocytes from immune NTx mice conferred a higher level of ACR and DFR on naive recipient mice, despite the marked difference in total number of T cells compared with immune Sham mice. Antigen-specific proliferation and interleukin-2 (IL-2) production by splenic T cells from immune NTx mice were significantly lower than in those from immune Sham mice. The proliferative response of T cells to exogenous IL-2 was also lower in NTx group. These results suggest that the requirement for the IL-2-driven T-cell proliferation system is basically low in the generation of effector T cells specific for L. monocytogenes.

Animals↗
PubMed1988

[A case of squamous cell carcinoma of the breast].

A case of squamous cell breast carcinoma is presented. The patient was 31-year old woman with a complaint of a right breast mass. The tumor was found to measure 7.0 x 8.0 cm without any inflammatory signs, and was associated with a bloody nipple discharge. Lymph-node metastases of the ipsilateral axillary and supraclavicular nodes were noted, and metastasis to the fifth lumbar vertebrae also was seen. Because of a diagnosis graded T4bN3M1, stage IV, an extended radical mastectomy was performed. Histologically, the major portion of this tumor consisted of a squamous cell carcinoma with a minimal component of adenocarcinoma and accompanying keratinization. The patient died of this cancer 5 months after the operation.

Adult↗
PubMed1988

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

Following a one shot injection with ceftriaxone (CTRX) 10 mg/kg or 20 mg/kg into 23 neonates (1 to 24 days old) including premature infants, plasma levels of CTRX were measured up to 12 hours post-dose in some cases and up to 72 hours post-dose in others and also urinary levels and urinary recovery rates were determined up to 12 hours post-dose. Furthermore, clinical, bacteriological and infection-prophylactic effects of CTRX were evaluated by the intravenous administration with the mean dose of CTRX of 47.7 mg/kg once daily or half the dose twice daily for 9 days on the average into 46 infants (0 to 6 months old) including neonates and premature infants; i.e., 21 cases with actual or suspected bacterial infections for the evaluation of clinical and bacteriological effects and 25 without bacterial infection for the evaluation of prophylactic effects against bacterial infection. The safety of CTRX was evaluated in 53 cases including 7 which were omitted from the efficacy evaluation due to adverse reactions and also in some cases from clinical laboratory parameters. The following is a summary of the results obtained: 1. Following the administration with CTRX 10 mg/kg into each of the neonates 6, 12, 13 and 21 days old (the 21 old one was premature), plasma levels of CTRX in these subjects reached their peaks at 5 minutes post-dose at levels of 59.38, 53.13, 37.50 and 50.00 micrograms/ml, respectively. The peak levels were similar to each other with an exception of the rather low level in the 13 day-old neonate. The plasma half-life times of CTRX in these subjects were 9.762, 7.775, 7.330 and 8.149 hours, respectively: The younger the infant the longer the half-life tended to be except the premature cases. Similarly, the younger the infant the larger the AUC was except for the premature case with the AUC values of 511.169, 324.714, 236.346 and 326.825 micrograms.hr/ml, respectively. The Vds were 0.709, 1.004, 1.316 and 0.696 liters, respectively, and the value for 13 day-old neonate was the largest. Urinary levels of CTRX reached between 42.00 and 298.30 micrograms/ml at some time within 12 hours post-dose in any cases. Urinary recovery rates in 12 hours post-dose were 79.98, 52.00, 56.82 and 60.14%, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteria↗