Biomedical subjects

M Asai

Publications and source records attributed to M Asai.

At least 145 records · Page 8Linked to original sources

PubMed1995

beta-Endorphin enhances phagocytosis of latex particles in mouse peritoneal macrophages.

The effects of beta-endorphin (beta End) on phagocytosis in peritoneal macrophages were examined by using flow cytometry (FCM). Beta End enhanced phagocytosis in a dose-dependent manner. Leucine-enkephalin (Leu-Enk), methionine-enkephalin (Met-Enk), alpha-endorphin (alpha End), gamma-endorphin (gamma End), alpha End (18-31) and beta End (28-31) had no such activity. Beta End (1-27) and beta End (6-31) enhanced phagocytosis less effectively than beta End did. Naloxone did not inhibit the enhancement of phagocytosis induced by beta End. Unstimulated control phagocytosis was partially suppressed in Ca2(+)-free EGTA-containing solution and even in this solution beta End enhanced phagocytosis. However, the enhancement was suppressed in the solution containing BAPTA-AM. The present study showed that beta End enhanced extracellular Ca2+ ([Ca2+]o)-dependent and -independent phagocytosis and that the enhancement is largely dependent on intracellular Ca2+ ([Ca2+]i). These results support the contention that beta End is one of the mediators that modulates the immune system.

Amino Acid Sequence↗

PubMed1995

Effectiveness of nilvadipine in two cases of chronic schizophrenia.

Nilvadipine is a calcium channel inhibitor used commonly for the treatment of cerebrovascular insufficiency. We observed two patients with schizophrenia whose psychiatric symptoms and tardive dyskinesia improved after the addition of nilvadipine to their antipsychotic drug regimen. The total score of the brief psychiatric rating scale (BPRS) in case 1 fell from 56 to 42 after 8 weeks on nilvadipine; while that of case 2 fell from 44 to 32. The total score of the abnormal involuntary movement scale (AIMS) in case 2 decreased from 12 to 7. No adverse effects occurred during treatment. Nilvadipine may thus offer a new approach to the adjunctive treatment of schizophrenia.

Calcium Channel Blockers↗

PubMed1995

Relationship of parental bonding to child abuse and dissociation in eating disorders in Japan.

Parental bonding patterns were studied in 52 female Japanese eating disorder outpatients with and without histories of sexual or physical abuse and with dissociation. Instruments included the Parental Bonding Instrument (PBI), the Dissociative Experiences Scale (DES) and the Dissociative Disorders Interview Schedule (DDIS). Those with physical abuse history, but not sexual abuse history, had significantly different parental bonding scores and higher DES scores compared with subjects without physical abuse. DES scores and PBI scores were not correlated. Although the PBI was useful in discriminating between those with and those without abuse histories, it did not detect differences in degree of dissociation. Lack of association of sexual abuse to PBI and DES scores may have been due to mild abuse.

Adolescent↗

PubMed1995

Effects of alcohol ingestion on vestibular function in postural control.

In order to define the acute effects of a moderate quantity of alcohol on balance, related to the vestibular function, vestibulo-ocular reflex (VOR) test, caloric test and dynamic posturography (EquiTest) were performed. Ten healthy male volunteers aged 19-27 average 22.8) years old imbibed 1.5 ml whisky (alcohol content 43%) per kilogram of body weight within 5 min. Blood alcohol level (BAL) was measured before administration and then after 30, 90, and 150 min. Equilibrium examinations were performed immediately after each blood sample was taken. At the highest alcohol level, significant reductions were found in VOR gain, in the maximum slow-phase velocity of the caloric test and in the equilibrium score of the sensory organization test in condition 5, when compared with those before drinking. In some typical cases, the subjects' response in all tests were most disturbed at the time when the highest alcohol level was measured. From our results, we conclude that a moderate quantity of alcohol affects not only the oculomotor system but also the vestibular system. Furthermore, it was suggested that one of the reasons for postural instability after drinking alcohol may be reduced vestibular function.

Adult↗

PubMed1995

Influence of a cold front upon the onset of Meniére's disease in Toyama, Japan.

In order to clarify the influence of a cold front (CF) upon the onset of Meniére's disease (MD), major CFs were defined by meteorological observations, and the influence of CFs on MD was evaluated by using the time n method. From our preliminary study it was seen that the onset of MD had its highest incidence exactly on days where a CF passed by. Out of the patients with MD, sudden deafness (SD) and Bell's palsy (BP) who visited our neurotological clinic of the Toyama Medical and Pharmaceutical University from 1987 to 1992, 67 MD patients, 70 SD patients and 70 BP patients could clearly define the date of the onset of their disease, and were therefore selected for this epidemiological study. Thirty-six our of the 67 MD patients had the first attack on the day when a CF passed by or on the next day. The results obtained from these studies were as follows. i) The onset of MD was influenced by the passing of a CF, and this influence was more specific in MD than in SD or BP. ii) In the 36 CF influence MD patients, the majority were over the forty years, and their hearing level was worse than that of the other 31 MD patients during the observation periods.

Adolescent↗

PubMed1995

[Changes in respiratory function before and after laryngectomy].

Many patients with head and neck cancer have a smoking history, and pulmonary complications frequently lead to post-operative death. Due to technical problems, spirometric pulmonary function tests are rarely performed in patients with laryngectomy. The purpose of this study is to evaluate respiratory function in patients with laryngectomy. We made a tracheal mask with a heat and moisture exchanging baseholder, and used it for spirometry. Eight patients with laryngectomy, including 5 with laryngeal cancer and 3 with hypopharyngeal cancer, were studied. Arterial blood gas analysis and pulmonary function measurements, such as VC, % VC, FEV1.0% and V25/height (V25/HT), were evaluated before and after laryngectomy. Statistical analysis of the data was performed with the Wilcoxon rank-sum test. The following results were obtained: 1) No statistically significant changes in arterial blood gases and FEV1.0% were found. 2) A statistically significant decrease in VC was found after total laryngectomy (p < 0.05). 3) A statistically significant decrease in V25/HT, which reflects small air way closure of the lung, was observed after total laryngectomy (p < 0.05). In all cases, the V25/HT value was below normal limits. We concluded that the decrease in VC was caused by a decrease in dead space in the upper airway, and that V25/HT may be a good parameter for evaluation of pulmonary function after laryngectomy.

Aged↗

PubMed1995

[Middle fossa acoustic neuroma surgery--indications and predictive factors for hearing restoration].

Between June 1990 and May 1993, 17 acoustic tumors were removed by the middle cranial fossa approach with attempted hearing preservation. Measurable hearing was restored in 13 patients (76.5%) and useful hearing (PTA < 50 dB, SDS > 50%) in 10 patients (58.8%). In addition, significant hearing improvement, greater than 10 dB in pure-tone average, was noted in 6 patients (35.3%). In the hearing improvement group, useful hearing was restored after tumor resection in two patients with poor preoperative hearing. These six patients with hearing improvement exhibited several findings in common: smaller tumors, sudden deterioration of hearing, trough type of audiogram, inferior vestubular nerve origin and short duration of hearing loss before surgery. Such signs suggested favorable preoperative prognostic factors for potential postoperative hearing improvement. Because there was no significant difference between postoperative facial nerve outcome in the middle cranial fossa approach and the translabyrinithine approach in our series of small tumors, we recommend the use of the middle cranial fossa approach for hearing preservation in patients with small tumors, even when their hearing is poor preoperatively.

Adult↗

PubMed1995

[Does aging influence effect of pirenzepine alone or combination of pirenzepine and famotidine on gastric secretion during anesthesia and surgery?].

Effect of pirenzepine alone or the combination of pirenzepine and famotidine on gastric secretion during anesthesia and surgery was evaluated in 52 elective surgical patients ranged in age from 17 to 68 years. These patients of each group were divided into two subgroups according to their age either 40 years and under or over. The patients underwent orthopedic, ophthalmic, ENT, plastic or non-abdominal general surgery under neuroleptanesthesia except 5 patients who had enflurane or isoflurane anesthesia. They received either pirenzepine 10 mg or the combination of pirenzepine 10 mg and famotidine 20 mg intravenously just before the induction of anesthesia. Volume and acidity of gastric juice were measured for 3 hours after the administration of these agents. Decrease in volume and acidity of gastric juice continued for more than 3 hours after the administration of pirenzepine alone or the combination of pirenzepine and famotidine, and it was more prominent in the combination group than in the pirenzepine group. There was no statistical difference in volume of gastric juice between the patients of 40 years and under in age and those over 40 years in each group. However, the intragastric pH tended to be lower in patients of 40 years and under in age than that in those over 40 years. A percentage of patients who had intragastric pH below 2.5 was larger in the pirenzepine administered patients of 40 years and under in age than that of the remaining patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

[Detection of lupus anticoagulant using a modified diluted Russell's viper venom time test].

Lupus anticoagulants (LA) are considered to be a significant risk factor in patients with unexplained thrombosis and are often present in women who have recurrent miscarriages. According to Petri et al, LA detectable using a diluted Russell's Viper Venom time (dRVVT) test are more closely linked with thrombosis in patients with systemic lupus erythematosus than are anticardiolipin antibodies. We evaluated a new simplified dRVVT test, that is, a combination of LUPO-TESTII and LUCOR, and found that the ratio of LUPO-TESTII/LUCOR values is a good indicator for detection of LA. The cut-off point of the ratio based on receiver-operating characteristic (ROC) analysis was set at 1.07. The sensitivity and specificity were 92.3% and 96.8%, respectively. The ratio of LUPO-TESTII/LUCOR values of 24 (92.3%) of 26 LA-positive patients was significantly higher than those of warfarin-treated patients, patients with hereditary clotting-factor deficiency and patients positive for specific clotting-factor inhibitors (p < 0.01). It was shown that the result was not influenced by warfarin and/or heparin treatment and the presence of specific clotting-factor inhibitors. The ratio of LUPO-TESTII/LUCOR values is regarded as a more useful indicator for the detection of LA than the platelet neutralization procedure test.

Female↗

PubMed1995

Involvement of interleukin-1 in immobilization stress-induced increase in plasma adrenocorticotropic hormone and in release of hypothalamic monoamines in the rat.

We investigated whether interleukin-1 (IL-1) activity in the rat hypothalamus was increased by immobilization stress (IS), and whether pretreatment with an interleukin-1 receptor antagonist (IL-1Ra) is capable of inhibiting IS-induced elevations of hypothalamic norepinephrine (NE), dopamine (DA), and serotonin (5-HT) and the levels of their metabolites as well as of plasma adrenocorticotropic hormone (ACTH). IL-1 activity was estimated with a bioassay using mouse thymocyte proliferation in the presence of concanavalin A. IL-1Ra was administered directly into the anterior hypothalamus, and monoamines were determined using a microdialysis technique and an HPLC system. First, we found that levels of IL-1 activity in the rat hypothalamus reached a maximum at 60 min after starting IS. Second, IL-1Ra (2 micrograms) significantly inhibited IS-induced increases in hypothalamic NE, DA, and 5-HT levels as well as the levels of their metabolites. In addition, IL-1Ra (2 micrograms) also inhibited the IS-induced elevation of plasma ACTH levels. Third, timing effects of IL-1Ra administration on the IS-induced monoamines or ACTH responses were examined. IL-1Ra (2 micrograms) administered at 5 or 60 min before the start of IS, but not at 5 or 60 min after IS had been started, exerted inhibitory effects on these responses, indicating that the effects of IL-1 occurred within 5 min after the initiation of IS. In summary, these results suggest that IS enhances biologically active IL-1 in the hypothalamus, and that hypothalamic IL-1 plays a role in the regulation of IS-induced responses including elevated monoamine release in the hypothalamus and activation of the hypothalamo-pituitary-adrenal axis. Moreover, since 5 min is too short a time for IS to induce production of IL-1, IS may augment the effects of preexisting IL-1 in the hypothalamus.

Adrenocorticotropic Hormone↗

PubMed1995

[Effect of ritodrine hydrochloride on fetal perfusion pressure in dually perfused human placenta].

Ritodrine hydrochloride is widely used in clinical obstetrics for the prevention of premature labor, but the knowledge of its effect on fetal circulation is limited. The purpose of this study was to elucidate changes in vascular resistance in the fetal placental circulation by using the dually perfused human placenta in vitro. The viability of the perfused placenta was maintained during the experiments because the production rate of hCG was constant. The transfer of ritodrine hydrochloride was observed and its concentration on the fetal side was about one third of maternal side at 120 min subsequent to the injection. The fetal perfusion pressure during the control period was 38.6 +/- 7.0 mmHg (mean +/- S.D., n=3). After the addition of ritodrine hydrochloride to the maternal circulation, the fetal perfusion pressure was decreased dose-dependently. The pressure was 95.4 +/- 1.8% at 80 ng/ml of ritodrine hydrochloride which was within the clinical concentration limits. It is concluded that ritodrine hydrochloride acts as a vasodilator on the fetal vasculature in the human placenta.

Adrenergic beta-Agonists↗

PubMed1995

[Validity of photographical dietary assessment; a preliminary analysis].

We estimated nutritional intake from color photographs taken of meals with a 35-mm camera, and compared them with the values calculated from the menu. Among 21 meals examined, the coefficient of correlation between the values by the photo method and those from examining the menu was appreciably high; 0.842 in energy, 0.828-0.931 in three major nutrients, and 0.745-0.940 in vitamins and minerals. The differences between the photo method and menu observation were 0-14.8% on average, and the coefficient of variation of the differences was 9.1-32.3%. Estimation of salt was, however, very poor, and the agreement was lower due to the cooking method used. Some differences were found among the dietitians in estimated values of several nutrients. The running cost was approximately 87-yen per meal, which may pose a problem for large-scale dietary surveys. Compared with the use of record, recall, and frequency questionnaire methods, the photo method was easily used by participants, especially those not used to cooking, and could be applied to eating out or for take-out food. Moreover, this method may provide not only quantitative data but also qualitative including eating atmosphere. When estimation is difficult due to the ingredients or recipe, combined use with record or recall methods can facilitate estimation. This photo method is thus considered to be a valid and feasible means of dietary assessment.

Food Analysis↗

PubMed1994

Longitudinal changes in symptoms and plasma homovanillic acid levels in chronically medicated schizophrenic patients.

A correlation has been noted between the changes in plasma homovanillic acid concentrations and changes in psychiatric symptoms induced by neuroleptic treatment. Our objective was to determine whether plasma homovanillic acid concentration changed in accordance with the changes in symptoms over time. Twenty-eight chronically medicated schizophrenic inpatients received the same treatment regimen for 1 year. Symptoms and plasma homovanillic acid concentrations were examined every month and whenever conditions deteriorated. Plasma homovanillic acid concentrations were significantly higher in the patients in the worst condition than in the patients in the best condition. Further, when comparing the best and worst conditions of both the positive and negative symptoms, the change in psychiatric rating of positive and negative symptoms was correlated significantly with the change in plasma homovanillic acid level. These results suggest that a change in plasma homovanillic acid concentration can be produced not only by neuroleptic-induced dopaminergic blocking but also by a change in positive and negative symptoms of schizophrenia.

Adult↗

PubMed1994

Valproic acid-induced rapid changes of met-enkephalin levels in rat brain. Probable association with abstinence behavior and anticonvulsant activity.

Valproic acid (VPA) induces abstinence behavior and analgesia and displays an anticonvulsant effect, but its exact mechanism of action is not yet clear. In order to view whether proenkephalin derived-peptides are involved in the mechanism of VPA-induced behavior, we analyzed immunoreactive-met-enkephalin (IR-ME) in rat striatum, midbrain, and amygdala 10, 20, and 45 min after i.p. injection of 200 mg/kg of VPA. VPA induced body shakes that peaked within 5 to 10 min. IR-ME increased in the striatum and decreased in the midbrain at 10, 20, and 45 min, reaching the highest and lowest levels at 10 and 20 min, respectively. No changes occurred in the amygdala. Gel filtration chromatography followed by HPLC of striatum extracts showed that the increased IR-ME levels corresponded to low molecular weight peptides, including ME. These results indicate that VPA produced rapid changes of IR-ME levels in rat brain and suggest peptide participation in the mechanisms of VPA-induced behavior. The anticonvulsant effect of VPA was tested in rats treated with pentylenetetrazol (70 mg/kg) 30 min after VPA (400 mg/kg) administration, and IR-ME was analyzed in striatum 15 min later. No changes in striatal IR-ME levels occurred in protected rats (no behavioral convulsions), compared with those treated only with VPA, but a significant decrease appeared in unprotected animals (clonic convulsions). These results suggest that striatal ME may participate in the mechanism of VPA-induced abstinence behavior and in the anticonvulsant effect. Otherwise, midbrain ME might be involved in other VPA behaviors such as analgesia.

Animals↗

PubMed1994

Analysis of the crystallization kinetics of lysozyme using a model with polynuclear growth mechanism.

A differential equation model with a polynuclear growth mechanism was formulated for a theoretical understanding of protein crystallization. The model equation contains two parameters characterizing nucleation and growth: the number of protein molecules constituting a critical nucleus and the order of growth kinetics. This model was applied successfully to explain the experimental data on the protein concentration changes due to nucleation and crystal growth of tetragonal and orthorhombic hen egg-white lysozyme. It was shown that the critical nucleus most probably consists of three or four molecules. The range and extent of the validity of the present model and analysis are discussed.

Animals↗

PubMed1994

Preoperative embolization for paraganglioma.

We have applied a new method of preoperative embolization to an intravagal and to carotid body paraganglioma, using estrogen dissolved in absolute alcohol and polyvinyl alcohol particles, which diffusely embolizes vessels from capillaries to main feeders. Total resection of the tumors after embolization was successively performed without postoperative complications; total blood loss was 205 and 130 ml, respectively, and the surgical time was approximately 3 hours in both cases. The technique, characteristics, and advantages of this method are discussed.

Angiography↗

PubMed1994

Inhibition by lithium of cyclic GMP formation without inhibition of nitric oxide generation in the mouse neuroblastoma cell (N1E-115).

We investigated the effects of lithium ion (Li+) on muscarinic receptor-mediated nitric oxide (NO) generation, and guanylate cyclase (GCase) activation using the mouse neuroblastoma clone, N1E-115. The levels of released NO were determined by measuring the levels of nitrite/nitrate in the incubation medium, and the activity of GCase was measured with an assay for cellular cyclic [3H] GMP levels. We determined that Li+ had no effects on muscarinic receptor-activated elevation of nitrite/nitrate levels, which were significantly inhibited by 100 microM L-NG-monomethylarginine, although it has been reported that Li+ inhibits muscarinic receptor-activated cyclic GMP formation in the cells. In addition, Li+ inhibited the cyclic GMP formation induced by an NO donor, sodium nitroprusside (SNP), in both intact cells and a crude cellular homogenate; thus, the inhibition by Li+ of muscarinic receptor-mediated cyclic GMP synthesis appeared to be at the level of GCase, but not NO synthase.

Animals↗

PubMed1994

Hearing improvement following removal of acoustic neuroma with preoperative sudden deafness.

We report three cases of small intracanalicular acoustic tumor with sudden hearing loss (SHL). The tumors were totally removed through the middle cranial fossa approach, preserving both the facial and cochlear nerves between one and four months after the onset of deafness. From one to three months postoperatively hearing has improved significantly. Hearing improvement in acoustic tumor surgery is a new aspect to be studied more in the future. Although the data are insufficient to draw broad conclusions, surgical removal of small acoustic tumors is rational to improve hearing, reduce or eliminate tinnitus and prevent recurrent attacks of deafness or vertigo. Factors relevant to postoperative hearing improvement are considered.

Audiometry↗