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Biomedical subjects

M Nagase

Publications and source records attributed to M Nagase.

At least 91 records · Page 5Linked to original sources
PubMed1995

Comparison of behavioural effects of repeated treatment with methamphetamine plus scopolamine and methamphetamine alone on behavioural sensitization and conditioned response.

We investigated how repeated treatments with methamphetamine (4.0 mg kg-1, i.p.) plus scopolamine (0.5 mg kg-1, i.p.) and methamphetamine alone effected behavioural sensitization and conditioned response in rats. Repeated methamphetamine plus scopolamine treatment induced a more progressive and enduring enhancement of focused stereotyped behaviour than repeated methamphetamine treatment. Stereotyped behaviour induced by methamphetamine plus scopolamine was reproduced by challenge injections of methamphetamine plus scopolamine, methamphetamine, and to a lesser extent by scopolamine challenges. The methamphetamine plus scopolamine-sensitized rats were conditioned to a low frequency tone (300 Hz, 100 dB) associated with the drug state. They exhibited a conditioned response to pairings of the tone (conditioned stimulus) and placebo injections. However, they did not respond to the tone alone or the placebo injections alone. The methamphetamine-sensitized rats failed to demonstrate any conditioning; only the repeated methamphetamine plus scopolamine treatment induced sensitization to the drug-associated tone. Pairings of exteroceptive conditioned stimulus-interoceptive unconditioned stimulus associations may provide an important source for conditioning to the tone associated with the drug state. We conclude that behavioural sensitization may operate via a reciprocal balance between the dopaminergic and cholinergic inhibitory systems, in favour of a dopaminergic dominance. Conditioning to the drug-associated tone may be mediated via a reciprocal balance between the two transmitter systems.

Animals↗
PubMed1995

Effect of particle size on alumina-induced production of reactive oxygen metabolites by human leukocytes.

To assess the role of crystal size in the biologic response, we quantitated the generation of reactive oxygen metabolites in human polymorphonuclear leukocytes (PMNs) or mononuclear leukocytes (MNs) with a chemiluminescence assay using 6 alpha-alumina preparations with average diameters of 0.6, 0.8, 3.2, 7.5, 28 and 68 microns on the basis of equal weights (1 mg/ml), and also on the basis of surface areas (100 cm2/ml). On an equal weight alumina particles induced PMN chemiluminescence in the following order of magnitude: 3.2 microns > 7.5 microns, 0.8 micron > 0.6 micron > 28 microns, 68 microns. The particulates induced MN chemiluminescence: 3.2 microns > 0.8 micron > 0.6 micron > 7.5 microns > 28 microns, 68 microns. On the basis of identical surface areas, alumina elicited PMN chemiluminescence: 3.2 microns > 7.5 microns, 0.8 micron > 0.6 micron, 28 microns, 68 microns. The particulates induced MN chemiluminescence: 3.2 microns > 0.8 micron > 0.6 micron, 7.5 microns > 28 microns, 68 microns. The maximal effect of particle size on the alumina-induced production of reactive oxygen metabolites by human leukocytes was seen at around 3 microns.

Aluminum Oxide↗
PubMed1995

[Anesthesia for SUMO wrestlers].

We anesthetized 34 sumo wrestlers. All patients were male. Average age was 21.1. Their height was 181.9 +/- 4.5 (mean +/- SD) cm, and they weighted 135.2 +/- 16.9 kg. Anesthetic methods used were spinal anesthesia alone in 17 patients, general anesthesia alone in 9, general anesthesia + epidural anesthesia/or spinal anesthesia/or axillary block in 8. The preoperative data showed findings common to obese patients; liver dysfunction, abnormal blood sugar, and abnormal ECG such as ST depression or left ventricular hypertrophy. For intubation, fiberscopy was required in one patient, and almost all patients required high FIO2, otherwise SaO2 decreased. For spinal anesthesia or epidural anesthesia, we needed long needles of 8 to 15 cm.

Adult↗
PubMed1995

[Postoperative pain relief by patient controlled analgesia using intravenous pentazocine].

Patient controlled analgesia (PCA) by intravenous pentazocine was performed to determine its efficacy and the dose required for the pain relief after gynecological or obstetric operations. After obtaining informed consent, studies were performed on 28 female patients (ASA I, II: Mean age 38.1 years: Mean weight, 53.8 kg) who had received gynecological or obstetric operations with lower abdominal incision. Anesthesia given was nitrous oxide and isoflurane combined with epidural anesthesia with 1% mepivacaine used only during the operation. Six patients had cesarian section under spinal anesthesia. No patients received opioid during anesthesia. PCA was performed with a Graseby PCA pump. Lockout time was 8 minutes and the bolus dose was 3 mg. In all the patients, satisfactory pain relief was obtained and no other analgesic was necessary. Mean initial dose was 169.4 micrograms.kg-1 and the mean doses used for following each 6 hours until 24 hours were 409.7, 368.6, 279.3 and 211.1 micrograms.kg-1 respectively. Evaluation of PCA by the patients after the procedure showed excellent (13 patients) good (12) and passable (3) analgesia. No significant complication was observed except temporary nausea in two patients. Satisfactory postoperative pain relief could be obtained by relatively small doses of pentazocine and adverse reactions related especially to sigma receptor could be avoided.

Adult↗
PubMed1994

Priming effect of hydroxyapatite on the chemiluminescence response in human polymorphonuclear leukocytes.

In order to determine whether hydroxyapatite modulates the response of polymorphonuclear leukocyte (PMN) to oxidative stimuli, human PMNs were incubated with a non-activating concentration (1 or 10 micrograms/ml) of hydroxyapatite prior to stimulation with N-formyl-methionyl-leucyl-phenylalanine (FMLP; 0.1 or 1 microM), phorbol 12-myristate 13-acetate (PMA; 100 pg/ml), sodium fluoride (50 microM), zymosan (1 microgram/ml), or the calcium ionophore A23187 (0.1 microM). Chemiluminescence was measured with an automatic microcomputer-controlled luminescence analyzer at 37 degrees C. Hydroxyapatite alone did not stimulate chemiluminescence at concentrations below 10 micrograms/ml. Levels 300-400% higher than 'stimulus only' controls without preincubation with hydroxyapatite have been recorded. This synergism between hydroxyapatite and subsequent stimuli reveals a new activity of hydroxyapatite and suggests that particulate material may prepare PMNs for an exaggerated inflammatory response to other phlogistic mediators. This is the first report demonstrating PMNs primed with particulate material.

Calcimycin↗
PubMed1994

Salt sensitivity of blood pressure in patients with 17 alpha-hydroxylase deficiency.

To clarify the salt sensitivity of blood pressure in 17 alpha-hydroxylase deficiency (17 alpha-HD), a mineralocorticoid-induced hypertension, we examined the responses of blood pressure to salt loading (250 mEq/day for 6 days) after salt restriction (25 mEq/day for 3 days) in two 17 alpha-HD patients who had markedly high plasma deoxycorticosterone (DOC) (5.27 and 6.59 ng/mL; normal, 0.08 to 0.28) and corticosterone (B) (93 and 357 ng/mL; normal, 0.35 to 8.42). In case 1, moreover, the same study was repeated when plasma DOC and B restored to almost normal with the dexamethasone treatment (1 mg/day) (0.34 and 0.45 ng/mL). Salt loading elevated mean blood pressure markedly in both patients (14% and 20%), associated with cumulative sodium retention and body weight gain. Hemodynamic study showed marked increases in cardiac output (25% and 69%), but only slight decreases in systemic vascular resistance with salt loading. On the other hand, the treatment with dexamethasone could attenuate the salt-induced increase in blood pressure (2%), accompanied by lesser sodium retention, body weight gain, and elevation of cardiac output (7%) in case 1. The slope of the renal function curve for sodium excretion was decreased in these patients, and was restored toward normal by dexamethasone in case 1. We conclude that the patients with 17 alpha-HD showed salt-sensitive hypertension due to excessive DOC and B, through the impaired renal function for sodium excretion, disproportionate increase in cardiac output, and inadequate vasodilation.

Adrenal Hyperplasia, Congenital↗
PubMed1994

Post-prandial triglyceride-rich lipoprotein metabolism: possible role of sialilated apolipoprotein E isoproteins.

While serum concentrations of triglyceride (TG) and apolipoprotein (apo) E decreased significantly after 75 g glucose load, serum triglyceride concentration increased markedly and apoB concentration decreased significantly after 100 g fat load in 10 healthy men. Chylomicrons and very low density lipoproteins (VLDL) increased after the fat load but decreased after the glucose load. ApoB-100/B-48 ratio in VLDL fraction decreased slightly at 30 min and increased markedly at 60 min after the glucose load. On the other hand, the ratio decreased definitely at 30 min and then increased until 90 min after the fat load. Isoelectric focusing (IEF) and two-dimensional gel electrophoresis revealed that the relative concentration of sialilated apoE in VLDL fraction decreased after the glucose load and increased after the fat load. In hypertriglyceridaemic patients, apoE3S1/E3 ratio in VLDL fraction was significantly higher than that in normal and hypercholesterolaemic patients. The results suggest that some structural changes in apoE, due probably to sialilation, may exert an influence on the hepatic uptake of the lipoproteins.

Administration, Oral↗
PubMed1994

Sequencing and expression of sheep angiotensinogen cDNA.

A sheep liver cDNA library was screened with a BstEII fragment of human angiotensinogen cDNA to obtain sheep angiotensinogen cDNA. The cDNA sequence showed that preangiotensinogen consisted of 452 amino acid residues (49 kDa) of angiotensinogen and 24 residues of a signal peptide. Recombinant sheep angiotensinogen (56 kDa) was expressed in COS-7 cells.

Amino Acid Sequence↗
PubMed1994

Correlation between histologic features and glomerular permeability in membranous nephropathy and immunoglobulin A nephropathy.

We evaluated the correlation between histologic features and glomerular permselectivity based on fractional clearances of dextrans relative to inulin (FCsDex). The subjects consisted of 12 healthy volunteers, 18 patients with membranous nephropathy, and 20 patients with immunoglobulin A nephropathy. In membranous nephropathy, FCsDex measured with large dextrans (radii larger than 56 A) increased as the capillary lesion progressed. Histologic examination showed that glomerular capillary alteration was the factor most closely linked to changes in FCsDex in membranous nephropathy. Proteinuria (normalized to glomerular filtration rate) did not correlate with FCsDex. Increased FCsDex tended to normalize during prednisolone treatment in membranous nephropathy. In immunoglobulin A nephropathy, the impairment of glomerular size selectivity depended on the degree of mesangial sclerosis and tubulointerstitial injury. FCs of dextrans of 59 A were correlated with the mesangial sclerosis index (r = 0.573, p = 0.050) and the tubulointerstitial injury index (r = 0.707, p = 0.003). Proteinuria (again normalized to glomerular filtration rate) was significantly correlated with FCs of large dextrans in immunoglobulin A nephropathy (r = 0.668, p = 0.008). We conclude that glomerular size-selective barriers were impaired both in membranous nephropathy and immunoglobulin A nephropathy. However, the mechanisms of impaired size selectivity might differ, at least in part, between these nephropathies. The predominant factors responsible for the size-selective defect seemed to be glomerular capillary wall lesions in membranous nephropathy but mesangial sclerosis or tubulointerstitial damages (or both) in immunoglobulin A nephropathy.

Adolescent↗
PubMed1994

[Effects of hyperventilation upon the spinal pain modulating system (third report)].

The purpose of this study is to investigate the mechanisms of the effect of hyperventilation on the spinal pain modulating system by using phentolamine. Under enflurane anaesthesia, cats received mid-collicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells, responding primarily to noxious peripheral stimuli, were sampled with a microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period, ventilation was changed to induce hypocapnia of PCO2 20-25 mmHg. After activities were well suppressed, phentolamine 0.5 mg with normal saline 1.0 ml was injected on the spinal cord. Changes of firings were investigated. When normocapnia was resumed, recovery followed. Hypocapnia of PCO2 20-25 mmHg significantly suppressed the activities of WDR cells. Phentolamine significantly antagonized the suppressive effects of hyperventilation upon the activities of WDR cells. Our results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell and the mechanisms of those suppressive effects are related to adrenergic pain modulating system.

Action Potentials↗
PubMed1994

[A case of acute renal failure in neuroleptic malignant syndrome associated with rhabdomyolysis--possible contributing role of hyperreninemia].

A schizophrenic woman, aged 45, was admitted complaining of high fever, oliguria, blackish urine, muscle swelling and pain. She had been treated for the past 3 years with haloperidol (8 mg), levomepromazine (150 mg), chlorpromazine (75 mg), lithium carbonate (600 mg), bromocriptine mesilate (7.5 mg), etizolam (1 mg), and flunitrazepam (2 mg), Physical examination revealed her to be an obese and uncommunicatable woman with swelling and weakness of the extremities and abdominal distension without borborygmus. Urine was dark brown and (+) for protein and occult blood. Blood chemistry analysis revealed BUN 71 mg/dl, creatinine 6.8 mg/dl, CPK 143,850 IU and myoglobin 3,980 ng/ml. PRA on the 11th hospital day was 96 ng/ml/hour. This patient fulfilled the Levenson's diagnostic criteria for manifestations of neuroleptic malignant syndrome (NMS). High PRA did not decrease after cessation of the diuretics. After treatment with dantrolene sodium and 10 treatments with hemodialysis, azotemia disappeared with the start of diuresis. The PRA also decreased to the normal level. Characteristic acceleration of the central sympathetic stimuli in NMS seemed to have induced hyperreninemia, which together with rhabdomyolysis, might have contributed to the development of acute renal failure.

Acute Kidney Injury↗
PubMed1994

[Effects of inorganic fluoride, inhalation time and dosage of sevoflurane on renal function during sevoflurane anesthesia of long duration].

In sevoflurane anesthesia of long duration, we studied correlations with renal function of the area under the curve (AUC), rate of decrease and maximum level of serum inorganic fluoride (F), sevoflurane dosage, and duration of administration. In 15 neurosurgical patients, we measured serum and urine levels of F, blood urea nitrogen (BUN), creatinine, serum and urine beta 2-microglobulin (BMG), and urine N-acetyl-beta-D-glucosaminidase (NAG). AUC and the rate of decrease of serum F were calculated. There were no correlations among the maximum level, AUC, the rate of decrease of serum F, sevoflurane dosage, duration of administration, BUN, creatinine, BMG, and NAG. It is concluded that in sevoflurane anesthesia of long duration, F, sevoflurane dosage and duration of administration do not affect renal function.

Adult↗