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Biomedical subjects

K Otsuka

Publications and source records attributed to K Otsuka.

At least 199 records · Page 11Linked to original sources
PubMed1995

[Bacteriological and clinical evaluation tazobactam/piperacillin in infectious diseases in surgical field].

We carried out bacteriological and clinical studies on tazobactam/piperacillin (TAZ/PIPC), a combination drug of piperacillin with the new beta-lactamase inhibitor tazobactam, in various infectious diseases in surgical field such as intra-abdominal infections (peritonitis and intra-abdominal abscess), hepatobiliary infections (cholecystitis, cholangitis and hepatic abscess) and secondary infections in wound, etc. The total number of cases treated with the combination drug was 164. Of these cases, 141 cases were assessable for clinical responses including 60 cases with intra-abdominal infections, 38 cases with hepatobiliary infections, and 43 cases with secondary infections. Clinical efficacy rates of the drug were 83.3% in cases with intra-abdominal infections, 86.8% in cases with hepatobiliary infections, and 95.3% in those with secondary infections, hence the overall efficacy rate was 87.9%. In the cases from which beta-lactamase producing strains were isolated, clinical efficacy rates were 84.8% in cases with intra-abdominal infections, 84.6% in those with hepatobiliary infections, and 96.2% in those with secondary infections, hence the overall efficacy rate was 88.9%. Bacteriological efficacy rates were 92.9% in cases with Gram-positive bacterial infections, 64.3% in those with Gram-negative bacterial infections, and 100% in those with anaerobic bacterial infections. Bacteriological efficacy rates were 84.2% in cases with single bacterial infections and 56.5% in those with multi-bacterial infections, and the overall bacteriological efficacy rate was 69.0%. In the cases of infections with beta-lactamase producing strains, bacteriological efficacy rates were 80.0% in cases with Gram-positive bacterial infections, 75.0% in those with Gram-negative bacterial infections, and 100% in those with anaerobic bacterial infections. They were 82.6% in cases with single bacterial infections and 57.9% in those with multi-bacterial infections; the overall bacteriological efficacy rate was 67.2%. The bacterial eradication rate was 79.9% against all the isolates, and it was 79.2% against beta-lactamase producing isolates. In addition, we compared the sensitivity distribution of the isolates to TAZ/PIPC with those to control drugs piperacillin (PIPC), cefotiam (CTM), ceftazidime (CAZ), sulbactam/cefoperazone (SBT/CPZ). The MIC50 and MIC90 values of TAZ/PIPC against all strains were 3.13 micrograms/ml and 50 micrograms/ml, respectively. MIC50 values show that TAZ/PIPC was two times less effective than CAZ and SBT/CPZ but four times more effective than CTM; furthermore, from the MIC90 values, TAZ/PIPC was four times more effective than PIPC, CTM and CAZ. The MIC50 and MIC90 values of TAZ/PIPC against beta-lactamase producing strains were 3.13 micrograms/ml and 50 micrograms/ml, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Abdominal Abscess↗
PubMed1995

[Motion discrimination as as test for visual motion perception].

Recent neurophysiological studies have indicated that there are two parallel pathways in vision processing independently shape and motion. There are many methods for examining perception of color and shape, but none for examining visual motion perception. In this study, we devised a "motion discrimination task (MDT)" for evaluating motion perception, which was displayed on a computer monitor, and recorded normal responses to the MDT in 90 normal subjects. Responses to MDT were not affected by visual acuity, but were affected by dot speed of the MDT. There was little trial-to-trial or subject variability in the MDT. These findings indicate that our MDT is a good clinical test for evaluating motion perception in human subjects.

Adolescent↗
PubMed1994

Optical resolution of amino acid derivatives by micellar electrokinetic chromatography with N-dodecanoyl-L-serine.

Optical resolution by micellar electrokinetic chromatography with N-dodecanoyl-L-serine (DSer) was investigated. Similarly to the use of sodium N-dodecanoyl-L-valinate or sodium N-dodecanoyl-L-glutamate, addition of sodium dodecyl sulfate (SDS), urea and organic modifiers such as methanol and 2-propanol (IPA) to DSer micellar solutions could give improved peak shapes and enhance the enantioselectivity. With a DSer-SDS-urea-methanol solution, six phenylthiohydantoin (PTH)DL-amino acids were separated and each enantiomeric pair was optically resolved. By using a DSer-SDS-urea-IPA solution, the same PTH-DL-amino acids were partially resolved, while PTH-DL-Thr was resolved only in this system. N-Dodecanoyl-L-aspartic acid and sodium N-tetradecanoyl-L-glutamate were also investigated, but satisfactory results were not obtained.

Amino Acids↗
PubMed1994

T cell activation-associated hepatic injury: mediation by tumor necrosis factors and protection by interleukin 6.

This study investigates the molecular mechanisms underlying the induction of and protection from T cell activation-associated hepatic injury. When BALB/c mice were given a single intravenous injection of concanavalin A (Con A) (> or = 0.3 mg/mouse), they developed acute hepatic injury as assessed by a striking increase in plasma transaminase levels within 24 h. Histopathologically, only the liver was injured while moderate infiltration of T cells and polymorphonuclear cells occurred in the portal areas and around the central veins. The induction of hepatic injury was dependent on the existence as well as the activation of T cells, as untreated BALB/c nu/nu mice or BALB/c mice pretreated with a T cell-specific immunosuppressive drug, FK506, failed to develop disease. Significant increases in the levels of various cytokines in the plasma were detected before an increase in plasma transaminase levels. Within 1 h after Con A injection, tumor necrosis factor (TNF) levels peaked, this being followed by production of two other inflammatory cytokines, interleukin 6 (IL-6) and IL-1. Passive immunization with anti-TNF but not with anti-IL-1 or anti-IL-6 antibody, conferred significant levels of protection. Moreover, administration of rIL-6 before Con A injection resulted in an IL-6 dose-dependent protection. A single administration of a given dose of rIL-6 completely inhibited the release of transaminases, whereas the same regimen induced only 40-50% inhibition of TNF production. More than 80% inhibition of TNF production required four consecutive rIL-6 injections. These results indicate that: (a) TNFs are critical cytokines for inducing T cell activation-associated (Con A-induced) hepatitis; (b) the induction of hepatitis is almost completely controlled by rIL-6; and (c) rIL-6 exerts its protective effect through multiple mechanisms including the reduction of TNF production.

Animals↗
PubMed1994

Separation of lipophilic compounds by micellar electrokinetic chromatography with organic modifiers.

Separation of lipophilic compounds such as polyaromatic hydrocarbons (PAH) by micellar electrokinetic chromatography (MEKC) with organic modifiers was investigated. Dimethyl sulfoxide (DMSO) and acetone were used as organic modifiers, and sodium dodecyl sulfate (SDS) as a surfactant or a micelle forming reagent. By using 25 mM SDS (pH 7.0), containing 50% v/v DMSO, 8 PAHs were separated. Similarly, with 25 mM SDS, containing 30% acetone, 13 PAHs were successfully separated. For the calculation of thermodynamic quantities, critical micelle concentrations of SDS in buffers containing DMSO or acetone were measured.

Acetone↗
PubMed1994

Telehygiene system for preventive chronopharmacology in space.

A remote computerized health care (telehygiene) system for space travel includes monitoring devices and pharmaceuticals aimed at the optimization of health and the environment. Early risk indicators are provided by dynamic characteristics of rhythms of several frequencies describing variation inside the physiologic range. These rhythm characteristics, assessed as one goes, can be updated and compacted as data accumulate by the use of chronobiologic software that resolves anticipated components of lower and lower frequency, thus providing summaries of data at intervals of differing length. At any time, harbingers of risk, including characteristics of circannual rhythms, can be retrieved in an instant. On their basis, early preventive action can be instituted for risk lowering and for delivery of timed treatment when needed. Preventive or curative health care in space and terrestrial spin-offs are the more effective the more of the chronome (time-structure) is resolved.

Aerospace Medicine↗
PubMed1994

A complete culture system for avian transgenesis, supporting quail embryos from the single-cell stage to hatching.

We report here a method to produce quail hatchlings by culture in vitro from the single-cell stage. The culture is composed of three steps. In the first step, the fertilized ovum surrounded by thick albumen obtained from the magnum is cultured for 24 hr at 41.5 degrees C in a tightly sealed 20-ml plastic cup with chicken thin albumen added to the equator level of the ovum (System Q1). In the second step, a quail egg shell, cut horizontally and emptied, is used as a bed shell. After the thick albumen is removed, the embryo with egg yolk is transferred to the bed shell and thin albumen from chicken eggs is added to fill the shell. Then, the embryo is cultured for an additional 52 hr at 37.5 degrees C while being rocked at an angle of 90 degrees at 30-min intervals (System Q2). The embryo is transferred again to a chicken bed shell and cultured at 37.5 degrees C with rocking at a 30-degree angle (System Q3). Just before hatching, the rocking of embryos is stopped. The procedure yielded a hatchability of 25%. For transgenesis, a plasmid construct containing a beta-actin-lacZ hybrid gene (pMiwZ) is microinjected into the ovum at the single-cell stage, which is cultured in vitro for 85-90 hr using Systems Q1 and Q2 consecutively. Seven out of 17 surviving embryos exhibited lacZ gene expression in embryonic tissues as detected by histochemistry. The procedure described here should be highly applicable for the production of transgenic birds.

Actins↗
PubMed1994

Hepatic metastasis after laparoscopic cholecystectomy for polypoid gallbladder cancer followed by radical surgery.

While laparoscopic cholecystectomy is being increasingly performed on patients with gallbladder disease, this approach in cases of polypoid lesions in the gallbladder may not always be justified. We report here a case of early development of intrahepatic metastasis after laparoscopic cholecystectomy for polypoid gallbladder cancer; wedge resection of the gallbladder bed and dissection of regional lymph nodes had to be done. When a malignancy of the gallbladder is suspected during preoperative examinations, open cholecystectomy should be done.

Adenocarcinoma, Papillary↗
PubMed1994

Interleukin-1 beta stimulates collagenase production by cultured human periodontal ligament fibroblasts.

To examine the effects of interleukin-1 beta (IL-1 beta) on collagenase production by human periodontal ligament fibroblasts (PLF) and gingival fibroblasts (GF) in culture, collagenase activity in conditioned media was determined using a novel procedure that circumvented interference by enzyme inhibitors. Fibroblasts obtained from five paired periodontal ligament and gingival tissues were cultured for two weeks, and then incubated for a further 72 h in alpha-MEM supplemented with various concentrations of IL-1 beta (0 to 1250 pg/ml). The conditioned media from individual cultures were harvested and treated with dithiothreitol to inactivate TIMPs, and then with APMA, to activate the latent collagenase. Collagenase activity was measured fluorometrically using FITC-collagen as a substrate. IL-1 beta induced a approximately 2.4 to 5.2-fold increase in collagenase activity in PLF compared to a approximately 1.4 to 2.2-fold increase in GF. These results are in contrast to previous studies in which collagenase activity was measured in the presence of TIMPs, and indicate that PLF are more sensitive to IL-1 beta than GF. Since both PLF and GF are present in periodontal lesions, it is possible that collagenase secretion stimulated by exposure to inflammatory cell products such as IL-1 beta may participate in the destruction of collagen fibers involved in periodontal attachment.

Cells, Cultured↗
PubMed1994

[Circadian profiles of blood pressure with respect to age].

UNLABELLED: The effects of ageing on nocturnal blood pressure (BP) and the circadian rhythm of BP were studied. Ambulatory BP and heart rate (HR) were monitored at 30-minute intervals for 24 hours, in 326 normotensive volunteers aged 15-83. The following groups were monitored: young: < 40 yrs, n = 177; middle: 40 yrs < or = - < 60 years, n = 100; old: 60 yrs < or =, n = 49 Firstly, the ratio of nocturnal fall (RONF) of BP (or HR) was calculated as follows: [(average day time BP (or HR)-average night time BR (or HR)]/averaged whole day BP (or HR) x 100. Then we calculated 2 measurements: 1. The dipper (RONF of BP (or HR) > or = 10% 2. The non-dipper. (RONF of BP (or HR) < 10%. A cosine fitting technique using the least-squares method was employed to find the circadian rhythm of BP and HR. The results of the study showed that the incidence of the non-dipper on systolic BP (SBP) was higher for old subjects than for young subjects. In addition, the nocturnal BP and HR were higher for old subjects than for young subjects. The circadian amplitude of HR was lower in old subjects. The circadian midline estimating statistic of rhythm (MESOR) or SBP increased with age. The circadian acrophase of BP and HR increased with age. CONCLUSION: non-dippers of BP and HR were observed in any age groups. The frequency of BP and HR non-dipper was greater for old subjects than young subjects. This result may suggest the clinical significance of nocturnal BP and HR for the evaluation of hypertensive subjects.

Adolescent↗
PubMed1994

Circadian profiles of blood pressure and heart rate of apparently healthy metropolitan Japanese.

The circadian waveform in blood pressure (BP) and heart rate (HR) was explored in metropolitan Japanese. Clinically healthy subjects (50 women and 50 men, aged 40-59 years) were selected for the study of computing a peer-group reference standard. Hypertensive subjects diagnosed by conventional criteria (systolic(S)BP/diastolic(D)BP > or = 160/90 mmHg) also volunteered for this study. Each was to provide measurements of SBP, DBP, and HR at 15 min intervals over 48 h by using an ambulatory monitor ABPM-630 (Colin Medical, Komaki, Japan). Reference limits were computed as 90% prediction limits specified by the circadian stage. Data in intervals of 30 min, displaced by 15 min, were used for the computation of these limits. Those time-qualified reference limits were reconstructed as 'three-component chronodesms' with the two harmonics (12 h and 8 h) in conjunction with the fundamental period (24 h). The coefficient of harmonics needed was determined by discrete Fourier transform (DFT). A diagnosis based on office BP readings was confirmed chronobiologically. As a result, the circadian BP profiles did not exceed the upper limit in 27/107 hypertensives for SBP and in 30/107 hypertensives for DBP. In conclusion, chronobiologic approaches improve the sensitivity and the reliability of diagnosis.

Adult↗
PubMed1994

Computer analysis of Holter electrocardiogram.

Computer analysis is indispensable for the interpretation of Holter ECG, because it includes a large quantity of data. Computer analysis of Holter ECG is similar to that of conventional ECG, however, in computer analysis of Holter ECG, there are some difficulties such as many noise, limited analyzing time and voluminous data. The main topics in computer analysis of Holter ECG will be arrhythmias, ST-T changes, heart rate variability, QT interval, late potential and construction of database. Although many papers have been published on the computer analysis of Holter ECG, some of the papers was reviewed briefly in the present paper. We have studied on computer analysis of VPCs, ST-T changes, heart rate variability, QT interval and Cheyne-Stokes respiration during 24-hour ambulatory ECG monitoring. Further, we have studied on ambulatory palmar sweating for the evaluation of mental stress during a day. In future, the development of "the integrated Holter system", which enables the evaluation of ventricular vulnerability and modulating factor such as psychoneural hypersensitivity may be important.

Diagnosis, Computer-Assisted↗
PubMed1993

Optical resolution by high-performance capillary electrophoresis. Micellar electrokinetic chromatography with sodium N-dodecanoyl-L-glutamate and digitonin.

Optical resolution by micellar electrokinetic chromatography with sodium N-dodecanoyl-L-glutamate (SDGlu) and with digitonin-sodium taurodeoxycholate (STDC) mixed micelles was investigated. Addition of sodium dodecyl sulphate, urea and methanol to SDGlu micellar solutions could give improved peak shapes and resolution. With SDGlu, phenylthiohydantoin (PTH) derivatives of five DL-amino acids (alpha-aminobutyric acid, methionine, norvaline, tryptophan and norleucine) were separated from each other and each pair of enantiomers was optically resolved. On the other hand, three PTH-DL-amino acids (norvaline, valine and alpha-aminobutyric acid) were also successfully resolved with a digitonin-STDC-urea solution (pH 2.5).

Amino Acids↗
PubMed1993

Long-term nasal continuous positive airway pressure administration can normalize hypertension in obstructive sleep apnea patients.

We investigated the way in which nasal continuous positive airway pressure (CPAP) affects the circadian profiles of blood pressure (BP) and heart rate (HR) in obstructive sleep apnea syndrome (OSAS) patients. Nine patients with OSAS, confirmed by nocturnal polysomnography, were studied with ambulatory blood pressure monitoring (Colin ABPM-630) during two 48-hour periods, before and during nasal CPAP treatment, at the Stanford University Sleep Disorders Clinic. During each 48-hour monitoring period, blood pressure measurements were taken by the ambulatory device every 30 minutes. During the ambulatory blood pressure recordings, nocturnal sleep time was defined as the period between 0000 hours to 0600 hours and active daytime was defined as the period between 1000 hours and 2000 hours. An average systolic blood pressure > 135 mm Hg during the 48-hour baseline recording was defined as hypertensive. Using these criteria, we selected four hypertensive and five normotensive patients. Average BP (systolic/diastolic) and HR during the 48-hour periods decreased significantly from 148.6/88.2 mm Hg to 138.7/81.4 mm Hg, and from 77.9 beats per minute (bpm) to 67.2 bpm in hypertensives during CPAP treatment (p = 0.04), but there were no significant changes observed in normotensives. Average BP, during the day and at night, decreased from 152.3/91.8 mm Hg to 141.2/85.1 mm Hg and from 133.9/76.8 mm Hg to 125.9/73.7 mm Hg, respectively, in the hypertensives during CPAP, but such changes were not observed in normotensives. Average HR during the day and at night decreased significantly from 85.2 bpm to 72.6 bpm and from 69.8 bpm to 56.5 bpm in the hypertensives (p = 0.04), but not in normotensives.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗