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Biomedical subjects

S Saeki

Publications and source records attributed to S Saeki.

At least 91 records · Page 5Linked to original sources
PubMed1994

[Effects of ketamine on somatosympathetic reflex discharges in cats].

Effects of ketamine on somatosympathetic reflex discharges induced from sympathetic trunk with electrical stimulation of superficial peroneal nerve were investigated in 51 cats under anesthesia with urethane and alpha chloralose. These reflex discharges through spinal cord and medulla oblongata consist of two components, A and C reflexes, which are derived from somatic myelinated and unmyelinated afferent fiber respectively. Amplitudes of both A and C reflex potentials were depressed significantly after intravenous injection of ketamine 10 mg.kg-1. The maximum depression was observed 5 min after administration. In decerebrated cats with surgical transection at the midbrain, both A and C reflexes were also depressed after administration of the same dosages, and the maximum level of the depression was more profound than that in brain intact cats. After intrathecal injection of ketamine 1 mg.kg-1 to the lumbar spinal region, a slight depression of C reflex was found, but, dosages of 10 mg.kg-1 significantly depressed both A and C reflexes to the similar levels as those in iv injection to brain intact cats. The maximum depression was observed 30 min after administration. The depressive effects on both reflexes of intravenous ketamine 10 mg.kg-1 were not antagonized by naloxone 0.06 mg.kg-1 in brain intact cats. These results suggest that the suppressive effects of ketamine on somatosympathetic reflexes are caused by direct inhibition of medulla oblongata and spinal cord, whereas supra-midbrain regions may be activated by ketamine, and the effect of ketamine is predominant on medulla oblongata in this situation rather than on the spinal cord.

Action Potentials↗
PubMed1993

Relevance of DT-diaphorase activity to mitomycin C (MMC) efficacy on human cancer cells: differences in in vitro and in vivo systems.

Using 4 human cancer cell lines, 4 tumors xenografted into nude mice, and 11 fresh tumor specimens removed at surgery, we investigated the relevance of NAD(P)H:quinone oxidoreductase (DT-diaphorase, DTD) activity (nmoles/min/mg protein) to mitomycin C (MMC)-induced cytotoxicity. In culture cell lines, KB cells had significantly higher levels of DTD activity (8260) than PH101 (1934), SH101 (1805) or K562 (1796), and the highest sensitivity to MMC. In contrast, the higher the DTD activity of xenografts, the greater their resistance to MMC, while the inhibition rate of relative tumor growth for MMC, as evaluated by the NCI protocol, was highest in SH-6, high in CH-5, lower in CH-4 and lowest in EH-6. The investigation using 11 fresh tumor specimens also showed an inverse relationship between IC50 values after a 30-min MMC treatment, as evaluated by ATP assay and DTD activities. Moreover, a non-toxic DTD inhibitor, dicoumarol (DIC), or flavin adenine dinucleotide (FAD), suppressed the efficacy of MMC in culture cells, but enhanced it in xenografts. Thus, we suggest that DTD may play an important role in MMC-induced cytotoxicity but MMC metabolism by DTD in solid tumors may differ from that in culture cells.

Animals↗
PubMed1993

Effect of trimebutine maleate on emptying of stomach and gallbladder and release of gut peptide following a solid meal in man.

We investigated the effect of orally administered trimebutine maleate on gastric and gallbladder emptying and on the release of gut peptide, pancreatic polypeptide (PP), and gastrin in humans for 120 min after ingestion of a solid meal. Gastric emptying was measured by a radionuclide technique. Gallbladder emptying was estimated by real-time ultrasonography. The oral administration of 200 mg of trimebutine maleate significantly shortened the lag time in starting gastric emptying (P < 0.05). Considering gallbladder emptying, trimebutine significantly inhibited the fasting emptying induced by neural reflex. Postprandially, there was a tendency toward an accelerated gallbladder emptying in the early phase. Neither the maximal percentage of gallbladder emptying nor the time of peak gallbladder emptying were affected. Trimebutine significantly blunted the post-prandial PP response in the cephalic and gastric phases, reflecting a vagal-cholinergic activity (P < 0.05). The PP response in the intestinal phase was also blunted. Gastrin release was significantly augmented only during the period of fasting after drug administration (P < 0.05). The major effect of trimebutine maleate appears to be a shortening of the lag time at the start of gastric emptying probably via its anticholinergic activity.

Administration, Oral↗
PubMed1993

Factors influencing return to work after stroke in Japan.

BACKGROUND AND PURPOSE: Few studies have identified factors that predict return to work after stroke in Japan. Our aim in this study was to determine the predictors of return to work after stroke in Japan. METHODS: We performed a retrospective cohort study on the association between patients' characteristics at admission and return to work in 230 first-stroke patients, adjusting for potential confounding factors. The patients were all aged younger than 65 years and were working, students, or housewives at the time of their stroke. Return to work was evaluated by a follow-up questionnaire. Data were analyzed using forward logistic regression analysis to compute odds ratios of return to work. RESULTS: The adjusted odds ratios (and 95% confidence intervals) for patients with normal muscle strength vs severe muscle weakness, without apraxia vs with apraxia, and with white-collar vs blue-collar occupation were 4.50 (1.04 to 19.42), 4.87 (1.28 to 18.54), and 3.33 (1.34 to 8.30), respectively. CONCLUSIONS: Significant predictors of return to work after stroke were no muscle weakness, absence of apraxia, and white-collar occupation.

Adolescent↗
PubMed1993

Suppression of nociceptive responses by spinal mu opioid agonists: effects of stimulus intensity and agonist efficacy.

To determine the influence of stimulation intensity on dose-response curves of three analgesics in halothane-anesthetized rats, continued immersion of the tail in 52.5 degrees C or 60 degrees C water for 15 s results first in a nociceptive reflex tail movement (tail flick = 2.8 +/- 0.4 s and 1.4 +/- 0.2 s, respectively), and a progressive increase in arterial blood pressure (delta BP = 21 +/- 1 and 24 +/- 1 mm Hg) and heart rate (delta HR = 27 +/- 2 and 32 +/- 2 beats/min). Intrathecally administered mu opioids, morphine (MOR), sufentanil (SUF), and [D-Ala2-N-Phe4,Gly-ol]-enkephalin (DAG), produced a dose-dependent inhibition of the tail flick and BP response with the relative activity being SUF = DAG > MOR. Although the magnitude of the response evoked by increasing stimulus intensity from 52.5 degrees C to 60 degrees C was increased only mildly (suggesting that both represented essentially supramaximal stimuli), this increase in stimulus intensity resulted in a significant rightward shift in the dose-response curves (decrease in apparent potency) of the three agonists, with the magnitude of the shift being MOR > SUF = DAG. Thus, the dose ratio (ED50 at 60 degrees C/ED50 at 52.5 degrees C) for these three analgesics given intrathecally on the tail flick and BP response was, respectively, 3.7 +/- 0.9 and 6500 +/- 465 for MOR; 0.5 +/- 0.9 and 2.4 +/- 0.9 for SUF; and 0.5 +/- 1.2 and 7.0 +/- 0.9 for DAG. Unlike SUF and DAG, with the 60 degrees C stimulus, the highest dose of MOR failed to abolish the BP and heart rate response. Previous work with an irreversible antagonist to define receptor occupancy requirements showed that the relative efficacy was SUF = DAG >> MOR. The present studies thus confirm the pharmacodynamically based prediction that for a given change in stimulus intensity, anesthetics with a high efficacy (DAG and SUF) show less shift in their dose response curves with a given increase in stimulus intensity than an agonist with low efficacy (MOR).

Animals↗
PubMed1993

[Two elderly cases of megacolon associated with cerebral infarction and diabetes mellitus].

The authors experienced two elderly patients of megacolon associated with cerebral infarction and diabetes mellitus. The first patient was a 66-year-old female who was admitted to our hospital for rehabilitation with a complaint of knee pain. She had suffered from diabetes mellitus since she was 30 years old and multiple cerebral infarction since age 62. Two months after admission, she had an episode of abdominal distension and obstructive symptoms. The roentgenograms of her abdomen showed diffuse dilatation of the colon. The second patient was a 78-year-old female admitted to our hospital with complaints of abdominal pain, distension of the abdomen and vomiting. Her abdomen was severely distended and plain roentgenograms of the abdomen, X-ray studies of the colon with the aid of contrast medium and CT scan of the abdomen showed striking dilatation of the colon. Megacolon may be congenital or acquired, and in acquired forms the conditions are secondary to organic diseases, smooth muscle atrophy, metabolic and neurological diseases, ulcerative colitis or psychogenic origin (idiopathic). The two patients in this series were suffered from cerebral infarction and diabetes mellitus. The mechanisms of megacolon seen in these two patients are not known, but involvement of the visceral autonomic innervation is presumed. Some elderly patients have chronic constipation, and dilatation of the colon may not be uncommon due to underlying diseases or drugs. Therefore, when examining elderly patients, careful attention should be paid to their bowel movement.

Aged↗
PubMed1993

[Mitomycin C and its bioreduction: relevance of NAD(P)H: quinone oxidoreductase activity to mitomycin C-induced DNA damage and cytotoxicity].

Using 4 human cancer cell lines, the relevance of NAD(P)H: quinone oxidoreductase (DT-diaphorase) activity to mitomycin C (MMC)-induced cytotoxicity was investigated. KB cells (oral epidermoid carcinoma) had more than 4 times higher DT-diaphorase activity than PH101 (pancreatic cancer), SH 101 (gastric cancer), or K562 (myelogenous leukemia) cells. The sensitivity to MMC was greatest in KB cells. Concentrations causing 50% inhibition of cell growth (IC50 value: microgram/ml) by 30 min treatment with MMC were 0.4 in KB, 1.1 in PH101, 1.6 in SH 101, and 1.9 in K 562. Treatment with 1.5 micrograms/ml of MMC induced DNA total cross links, and the indices were 0.18 in KB, 0.10 in SH101, 0.09 in SH101, and 0.06 in K 562. When DT-diaphorase activity was inhibited by non-toxic dicoumarol (50 microM), DNA damage and cytotoxic activity induced by MMC were decreased in all cells examined. Especially in KB cells, it was remarkable. Since it was shown that the level of cellular DT-diaphorase activities were correlated with the responses to MMC, we suggest that bioreduction by DT-diaphorase may activate MMC.

Carcinoma, Squamous Cell↗
PubMed1993

[Causes of idiopathic interstitial pneumonia (IIP): inhaled dust as environmental problem].

We have reported that patients with IIP can be roentgenologically grouped into two subtypes, typical (type-A) and atypical (type-B). The characteristic feature of X-ray findings in type-A is marked restriction of the lung, especially of the lower lobes, and in type-B is emphysematous changes in addition to the findings of type-A. In this study, to clarify the pathological findings of these two subtypes, 60 IIP patients in whom open lung biopsy and/or autopsy were performed were studied both clinically and pathologically. The following results were obtained. 1) Pathological features of type-A were alveolitis, marked restriction of the lung secondary to atelectasis and fibrosis of lung parenchyma, and honeycombing as a result of remodeling. 2) The features of type-B were intra-alveolar organization and secondary emphysema after intra-alveolar inflammation (pneumonia) overlapped the pathological changes of type-A. 3) Patients with a history of dust inhalation were much more frequently observed in type-B than in type-A (p < 0.01). These results suggest that inhaled dust may be a causative factor of IIP, especially of type-B.

Dust↗
PubMed1993

[Mitomycin C associated hemolytic uremic syndrome--a case report and review of the Japanese cases].

A 36-year-old man who developed hemolytic uremic syndrome (HUS) associated with mitomycin C (MMC) after the radical operation for early gastric cancer was reported. He was successfully treated with hemodialysis and transfusion of fresh frozen plasma. However, the pathogenesis and the effective treatment of this syndrome are still undetermined. The literature on MMC-induced HUS in Japan was reviewed, and the relationship between the prognosis and the patients conditions, such as sex, age, site of primary cancer, total dose of MMC, latent period from MMC administration, laboratory findings at the time of diagnosis and treatment with steroids or plasma exchange, were analysed. Patients less than 60 years old or treated with plasma exchange were found to be associated significantly with a favorable outcome. The most frequent cause of death was pulmonary edema or respiratory failure. In conclusion, early treatment with plasma exchange appeared to result in a better prognosis.

Adult↗
PubMed1993

[A case of liver dysfunction after isoflurane anesthesia].

A 72 year old female developed severe liver damage after intracranial surgery under isoflurane anesthesia. This patient showed a type of drug-induced liver dysfunction, and the result of delayed lymphocyte stimulation test was highly suggestive of isoflurane as the causative material, although influence of blood transfusion on the liver damage cannot be neglected completely.

Aged↗
PubMed1993

[Body composition (densitometry-hydrostatics), skinfold thickness, BMI and their relationships in junior high school girls].

A study was conducted to evaluate body composition (Hydrostatics = Under-Water Weighing), skinfold thickness, and BMI in 97 junior high school girls, aged 12 to 15, in Nagasaki City. Body density was measured by under-water weighing, and the two compartments--fat weight (Fat) and lean body mass (LBM, or fat free weight: FFW)--were calculated using the formulas of Brozek et al. The results were as follows; 1. Mean values of body density were 1.0501 in first grade girls, 1.0476 in the second grade, and 1.0466 in the third grade. 2. Mean values of percentage body fat (% Fat) were 21.1% in the first grade, 22.1% in the second and 22.5% in the third. 3. Lean body mass (LBM) and LBM/Height increased significantly with advance from the first to the third grade. 4. The correlation coefficient between percent body fat and the sum of two skinfold thicknesses, the sum of three skinfold thicknesses, or the sum of seven skinfold thicknesses were 0.81, 0.80, and 0.82 respectively and all statistically significant (p < 0.001). 5. The correlation coefficient between BMI and the sum of two skinfold thicknesses, the sum of three skinfold thicknesses (r = 0.841) or the sum of seven skinfold thicknesses were 0.85, 0.84, and 0.84 respectively, and all statistically significant (p < 0.001). 6. Mean values of BMI, WSR, ASR, and WHR in all subjects (n = 97) were 19.6, 0.72, 0.39 and 0.43 respectively.

Adolescent↗
PubMed1993

[Retrospective analysis of 15 cases with severe pulmonary embolism].

We evaluated retrospectively the clinical indicators for the treatment of 15 patients with severe pulmonary embolism. All patients had moderate or severe pulmonary hypertension with deteriorated oxygenation. Thrombolytic agents and catecholamines were administered and mechanical ventilation was performed so as to treat right heart failure and improve oxygenation. In 14 patients, the pulmonary artery pressure decreased gradually and PaO2 increased in response to these therapies. The 14 patients were discharged from ICU without any symptoms. One patient died of cerebral hemorrhage due to the side effects of tissue plasminogen activator. We conclude that the pulmonary artery pressure and PaO2 are useful indicators for the treatment of the early phase of severe pulmonary embolism. Moreover, timely use of cetecholamine is very important for the maintenance of pulmonary circulation and acceleration of thrombolysis.

Adolescent↗
PubMed1992

[A descriptive epidemiology on sudden death among workers].

A survey on sudden unexpected death, that is, death within 24 hours from acute onset, among Japanese workers was carried out. Questionnaires were sent to full-time occupational health physicians who were active members of the Japan Association of Industrial Health at the time of the survey. Though 241 doctors answered (response rate: 61.5%), only 53 of them who had had both sudden death cases and the desire to join in this research co-operated in this survey. During the 5 years of observation (from Jan. 1, 1986 to Dec. 31, 1990), 143 cases of sudden death, 141 males and 2 females, were reported. The mean age was 46.5 (S. D. 10.5) for males. The ages of the 2 females were 31 and 44. Onset took place most frequently at home (55%) and most often during sleep (26%). This may be due to the higher rate not only of onset but of death resulting from acute onset at home and during sleep. Similar to the previous findings, a small peak of incidence was found early in the morning (4:00 AM--9:00 AM), although this was not statistically significant. However, the weekly and seasonal variations were a little different from previous reports. In this study, sudden death tended to occur more on Monday, Thursday, Friday, and Saturday (not statistically significant), and as for the seasonal variation, more cases occurred in April, November, and December which were statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effects of isoflurane and halothane on the calcium ion-tension curve in rat myocardium.

In order to clarify the interaction of volatile anesthetics and extracellular calcium ion on the myocardial contraction, effects of both isoflurane (1.0%) and halothane (0.5%) on the extracellular calcium ion concentration ([Ca(2+)](O))-tension curve were studied. Increasing [Ca(2+)](O) enhanced the myocardial contraction response, and the maximal response was obtained at [Ca(2+)](O) of 3.0 mM. Halothane depressed the maximal value of the tension development in response to increasing [Ca(2+)](O), while isoflurane did not ( P < 0.01). The probit response of the developed tension to the changes in [Ca(2+)](O) indicated that isoflurane increased the median effective concentration (EC(50)) of [Ca(2+)](O) significantly from 0.484 +/- 0.051 (mean +/- SEM) to 0.870 +/- 0.056 mM ( P = 0.001), but halothane did not ( P = 0.018). Therefore, 1.0% isoflurane was concluded to move the [Ca(2+)](O)-tension curve to the right, while a downwards shift occurred with 0.5% halothane.

Journal Article↗
PubMed1992

Effectiveness of pressure support ventilation for mechanical ventilatory support in patients with status asthmaticus.

We compared the effects of pressure support ventilation (PSV) with those of assist control ventilation (ACV) on breathing patterns and blood gas exchange in six patients with status asthmaticus. Both PSV and ACV delivered adequate minute ventilation (PSV: 7.5 +/- 1.4 l/min/m2, ACV: 7.3 +/- 1.3 l/min/m2) to correct respiratory acidosis (pH = 7.33 +/- 0.12 during both PSV and ACV) and prevent hypoxia. Peak airway pressure during PSV was significantly lower with the same tidal volume than that during ACV (PSV: 30 +/- 10 cmH2O (2.9 +/- 1.0 kPa), ACV: 50 +/- 13 cmH2O (4.9 +/- 1.3 kPa)). The lower airway pressure during PSV was due to persistent inspiratory muscle activity. The oxygen cost of breathing estimated by oxygen consumption was equivalent in both modes. We conclude that PSV is effective in supplying tidal volumes adequate to improve hypercarbia at markedly lower airway pressures than ACV.

Adolescent↗
PubMed1992

Pericholangitis with ulcerative colitis following autoimmune hepatitis over 12 years.

A 35-year-old woman was diagnosed as autoimmune hepatitis 12 years ago by abnormal findings of liver tests including lupus erythematosus (LE) cell phenomenon and liver biopsy. She was admitted in May 1990 with a history of lower gastrointestinal bleeding. Colonoscopy with biopsy and barium enema revealed chronic ulcerative colitis along the entire colon. Since liver tests did not respond well to prednisolone treatment, liver biopsy was again performed and it revealed periductal inflammation with small duct proliferation, a finding compatible with pericholangitis. We herein report this patient who was initially diagnosed as autoimmune hepatitis and thereafter found to be pericholangitis associated with ulcerative colitis.

Adult↗