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Biomedical subjects

H Higuchi

Publications and source records attributed to H Higuchi.

At least 73 records · Page 4Linked to original sources
PubMed2000

Effect of single intracerebroventricular injection of alpha-interferon on monoamine concentrations in the rat brain.

The effect of a single intracerebroventricular (i.c.v.) injection of alpha-IFN on levels of central monoamines and their metabolites in six brain regions (frontal cortex, striatum, hypothalamus, hippocampus, mid brain and medulla) of the rat was investigated. Wistar rats (n=10) were decapitated 2 h after i.c.v. injection of alpha-IFN. The brain tissues were homogenized, and monoamine concentrations were measured by high-performance liquid chromatography with an electrochemical detector. The levels of 5-hydroxytryptamine (5-HT) were significantly reduced in the frontal cortex in a dose-dependent manner, and the levels of both 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) were reduced in the mid brain and the striatum. The levels of noradrenaline (NA) were also significantly reduced in a dose-dependent manner in the frontal cortex. Some neurophysiological changes that affect activity of the noradrenergic or/and the serotonergic neuron system may occur during IFN therapy.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2000

Evaluation of the cardiovascular responses to fiberoptic orotracheal intubation with television monitoring: comparison with conventional direct laryngoscopy.

STUDY OBJECTIVE: To evaluate and compare cardiovascular responses to a new method of orotracheal intubation incorporating TV monitoring, with conventional orotracheal intubation via rigid blade laryngoscopy. DESIGN: Prospective single-blind study. SETTING: Operating room of a medical college hospital. PATIENTS: 90 ASA physical status I and II surgical patients requiring general anesthesia and orotracheal intubation. INTERVENTIONS: Patients were randomly allocated to two groups, one for the new intubation method and the other for conventional intubation using a rigid laryngoscope. In the new method, an anesthesiologist inserted an endotracheal tube alone into the trachea via TV monitoring through the bronchoscope, which was inserted by an assistant through the mouth to the middle larynx. The patient's trachea was intubated without extreme stretching of laryngeal tissues or deep insertion of the tip of the bronchoscope. In the conventional method, orotracheal intubation was performed with rigid direct laryngoscopy. MEASUREMENTS: Noninvasive blood pressure (BP) and heart rate (HR) were measured before arrival at the operating room, and before and after orotracheal intubation. MAIN RESULTS: Although this method was expected to be a minimally invasive fiberoptic intubation technique, the patients showed significant increases in BP and HR. No significant differences between the two groups were observed in cardiovascular responses immediately after intubation: the systolic BP, 169.5 +/- 28.3 versus 167.0 +/- 23.1 mmHg, and HR, 100.2 +/- 18.2 versus 98.8 +/- 16.6 bpm. CONCLUSIONS: Insertion of an endotracheal tube may itself be the most invasive stimulus during intubation procedures.

Adult↗
PubMed2000

Low dose carvedilol inhibits progression of heart failure in rats with dilated cardiomyopathy.

The cardioprotective properties of carvedilol (a vasodilating beta-adrenoceptor blocking agent) were studied in a rat model of dilated cardiomyopathy induced by autoimmune myocarditis. Twenty-eight days after immunization, surviving Lewis rats (32/43=74%) were divided into three groups to be given 2 mg kg(-1) day(-1) (Group-C2, n=10) or 20 mg kg(-1) day(-1) (Group-C20, n=10) of carvedilol, or vehicle (0.5% methylcellulose, Group-V, n=12). After oral administration for 2 months, body weight, heart weight (HW), heart rate (HR), rat alpha-atrial natriuretic peptide (r-ANP) in blood, central venous pressure (CVP), mean blood pressure (mean BP), peak left ventricular pressure (LVP), left ventricular end-diastolic pressure (LVEDP), +/-dP dt(-1) and area of myocardial fibrosis were measured. Values were compared with those for normal Lewis rats (Group-N, n=10). Two out of 12 (17%) rats in Group-V died from day 28 to day 42 after immunization. No rat died in Groups-C2, -C20 and -N. Although the CVP, mean BP, LVP and +/-dP dt(-1) did not differ among the three groups, the HW, HR and r-ANP in Group-C2 (1.14+/-0.03, 339+/-16 and 135+/-31) and Group-C20 (1.23+/-0.04, 305+/-8 and 156+/-24) were significantly lower than those in Group-V (1.36+/-0.04 g, 389+/-9 beats min(-1) and 375+/-31 pg ml(-1), respectively). The LVEDP in Group-C2 was significantly lower than that in Group-V (7.4+/-1.4 and 12.2+/-1.2 mmHg, respectively, P<0. 05). The area of myocardial fibrosis in Group-C2 was smaller than that in Group-V (12+/-1 and 31+/-2%, P<0.01). These results indicate that a low dose of carvedilol has beneficial effects on dilated cardiomyopathy.

Animals↗
PubMed2000

Analysis of the functional characteristics of L-selectin and its expression on normal and CD18-deficient bovine neutrophils.

In vivo responsiveness to epinephrine, expression of L-selectin on neutrophils, changes in intracellular calcium ([Ca2+]i), sulfatide-induced superoxide production and tyrosine phosphorylation in neutrophils were evaluated to elucidate the role of L-selectin-associated functions of normal and CD18-deficient bovine neutrophils. The number of neutrophils in peripheral blood was significantly increased (P < 0.05) in four normal calves at 5-20 min after in vivo administration of epinephrine; however, no significant increase of neutrophils was found in three calves with bovine leucocyte adhesion deficiency (BLAD). Expression of L-selectin on neutrophils from three calves with BLAD was 61-77% of that of normal calves. Pretreatment of neutrophils with phorbol myristate acetate caused a marked decrease in the expression of L-selectin on neutrophils from both normal and BLAD calves. The sulfatide-induced sustained phase of [Ca2+]i concentration in neutrophils from calves with BLAD was significantly (P < 0.05) decreased. Following stimulation with aggregated IgG, the transient phase of [Ca2+]i in neutrophils from normal and BLAD calves was increased; however, the sustained phase of [Ca2+]i in BLAD neutrophils was significantly lower (P < 0.05) than that of controls. Sulfatide-induced O2- production and chemiluminescent response in neutrophils from calves with BLAD were 48-51% of those of normal calves and were inhibited by genistein and wortmannin, respectively, in a dose-dependent manner. The amount of tyrosine phosphorylated 100 kDa protein in neutrophils from BLAD calves stimulated with sulfatides was 57% of that of controls. The degree of L-selectin expression on neutrophils was correlated with the intracellular signalling events and the related superoxide production.

Animals↗
PubMed2000

Compound A concentrations during low-flow sevoflurane anesthesia correlate directly with the concentration of monovalent bases in carbon dioxide absorbents.

UNLABELLED: Sevoflurane degrades to Compound A, which is nephrotoxic in rats. Potassium hydroxide (KOH) and sodium hydroxide (NaOH) are primary determinants of this degradation reaction. To address this, new carbon dioxide absorbents, such as Amsorb((R)) (A; Armstrong Medical, Coleraine, Northern Ireland), which contains neither KOH nor NaOH, Drägersorb 800 Plus((R)) (D; Dräger, Luebeck, Germany), and Medisorb((R)) (M; Datex-Ohmeda, Bromma, Sweden), which contain some NaOH (1% to 2%) and only trace amounts of KOH (0.003%), were recently developed. We compared Compound A concentrations using these three CO(2) absorbents during low-flow (1 L/min) sevoflurane anesthesia in surgical patients, with those using a conventional CO(2) absorbent, Drägersorb 800 (C). The mean Compound A concentrations +/- SD using C, A, D, and M were 18.7 +/- 2.5, 1.8 +/- 0.7, 13.3 +/- 3.5, and 11.2 +/- 2.6 ppm, respectively, with significant differences (P < 0.001; A versus C, A versus D, A versus M, C versus D, C versus M). Amsorb prevented the degradation of sevoflurane to Compound A, whereas Drägersorb 800 Plus and Medisorb decreased the degradation to Compound A. IMPLICATIONS: Sevoflurane degradation to Compound A is decreased by lowering the concentration of monovalent bases in the carbon dioxide absorbent (Drägersorb 800 Plus) [Dräger, Luebeck, Germany] and Medisorb) [Datex-Ohmeda, Bromma, Sweden]) and is virtually eliminated in the absence of these bases (Amsorb) [Armstrong Medical, Coleraine, Northern Ireland]).

Absorption↗
PubMed2000

Factors affecting long-term results after arthroscopic partial meniscectomy.

The purpose of this study was to determine functional and radiographic changes on long-term followup of knees with isolated meniscal tears. Sixty-seven patients were evaluated retrospectively with an average of 12.2 years' followup using the scale of Tapper and Hoover. The criteria for the radiographic results were the Fairbank's changes as the standard comparing the preoperative and the postoperative conditions of the affected knee with the contralateral knee. Seventy-nine percent of the patients had a satisfactory outcome in terms of function. The amount of meniscus removed and the Outerbridge classification of the articular cartilage at the time of the meniscectomy were determining factors for long-term functional results. Osteoarthritic deterioration was seen in 48% of patients after the surgery, but radiographic deterioration after arthroscopic partial meniscectomy was mild on long-term followup. Medial meniscectomy and the amount of meniscus removed were risk factors for postoperative radiographic change. Age, gender, and the degree of cartilage degeneration at the time of operation, in contrast, showed no significant association. Arthroscopic partial meniscectomy for isolated meniscal injury yields favorable functional results but leads to significantly increased osteoarthritic change in the long-term.

Adolescent↗
PubMed2000

Courtship song recognition in the Drosophila melanogaster complex: heterospecific songs make females receptive in D. melanogaster, but not in D. sechellia.

The courtship song emitted by male wing vibration has been regarded as one of the most important signals in sexual isolation in the species of the Drosophila melanogaster complex. Inter- and intraspecific crosses were observed using males whose wings were removed (mute) or females whose aristae were removed (deaf). Females of D. melanogaster, D. simulans, and D. mauritiana mated with heterospecific males in the song-present condition (cross between normal females and winged males) more often than in the no-song condition (cross between normal females and wingless males or between aristaless females and winged males) or they showed no preference between the two conditions. It is possible that in these females heterospecific courtship songs play a role as if they were conspecific. In contrast, the females of D. sechellia mated with D. melanogaster or D. simulans males in the no-song condition more often than in the song-present condition, suggesting that they reject males with heterospecific song. Female mate recognition depending on the courtship song in D. melanogaster, D. simulans, and D. mauritiana is considered to be relatively broader and that in D. sechellia narrower.

Animals↗
PubMed2000

Effects of epinephrine and lactate on the increase in oxygen consumption of nonexercising skeletal muscle after aerobic exercise.

The purpose of this study was to measure O2 consumption of nonexercising skeletal muscles (VO2nonex) at rest and after aerobic exercise and to investigate the stimulant factors of O2 consumption. In experiment 1, we measured the resting metabolic rate of the finger flexor muscles in seven healthy males by 31P-magnetic resonance spectroscopy during a 15 min arterial occlusion. In experiment 2, the VO2nonex of the finger flexor muscles was measured using near infrared continuous wave spectroscopy at rest, immediate postexercise, and 3, 5, 10, 15, and 20 min following a cycling exercise at a workload corresponding to 50% of peak pulmonary O2 uptake for 20 min. We also monitored deep tissue temperature in the VO2nonex measurement area and determined catecholamines and lactate concentrations in the blood at rest and immediate postexercise. VO2nonex at rest was 1.1 +/- 0.1 microM O2/S (mean +/- standard error) and VO2nonex after exercise increased 59.6 +/- 7.2% (p < 0.001) from the resting values. There were significant correlations between the increase in VO2nonex and the increase in epinephrine concentration (p < 0.01), and between the increase in VO2nonex and the increase in lactate concentration (p < 0.05). These results suggest that epinephrine and lactate concentrations are important VO2nonex stimulant factors.

Adult↗
PubMed2000

Quantification of ischemic muscle deoxygenation by near infrared time-resolved spectroscopy.

The purpose of this study was to quantify muscle deoxygenation in human skeletal muscles using near infrared time-resolved spectroscopy (NIRTRS) and compare NIRTRS indicators and blood saturation. The forearm muscles of five healthy males (aged 27-32 yrs.) were monitored for changes in hemoglobin saturation (SO2) during 12 min of arterial occlusion and recovery. SO2 was determined by measuring the temporal profile of photon diffusion at 780 and 830 nm using NIRTRS, and was defined as SO2-TRS. Venous blood samples were also obtained for measurements of SvO2, and PvO2. Interstitial PO2(PintO2) was monitored by placing an O2 electrode directly into the muscle tissue. Upon the initiation of occlusion, all parameters fell progressively until reaching a plateau in the latter half of occlusion. It was observed at the end of occlusion that SO2-TRS (24.1 +/- 5.6%) agreed with SvO2 (26.2 +/- 6.4) and that PintO2 (14.7 +/- 1.0 Torr) agreed with PvO2 (17.3 +/- 2.2 Torr). The resting O2 store (oxygenated hemoglobin) and O2 consumption rate were 290 microM and 0.82 microM s-1, respectively, values which reasonably agree with the reported results. These results indicate that there was no O2 gradient between vessels and interstisium at the end of occlusion.

Adult↗
PubMed2000

Systemic kappaAL amyloidosis associated with bovine leukocyte adhesion deficiency.

Histopathologic and immunohistochemical examinations were conducted on a 5-year-old Holstein-Friesian cow with systemic kappaAL amyloidosis associated with bovine leukocyte adhesion deficiency. Amyloid deposits were present in the perivascular and intercellular spaces of the visceral organs, such as the liver, kidneys, pancreas, adrenal glands, and upper alimentary tract. Amyloid was stained positively with Congo red with or without 5% potassium permanganate pretreatment and had green birefringence observed under polarized light. Immunohistochemically, amyloid reacted strongly against anti-bovine IgG (H+L) and anti-bovine kappa-light chain and reacted weakly against bovine X-light chain antibodies but was negative for anti-human amyloid AA antibody. This is the first description of AL amyloidosis immunohistochemically related to immunoglobulin kappa-light chains of precursor protein in cattle.

Amyloid↗
PubMed2000

Reliability and validity of the Japanese version of the Temperament and Character Inventory.

The Temperament and Character Inventory was translated into Japanese, and, to confirm the psychometric properties of the inventory, three samples were recruited from a nonpatient population. In nonpatient population A (N = 555), the full version (240 items) of the inventory with dichotomous measuring, along with the General Health Questionnaire and the Social Desirability Scale, were distributed to the subjects. Factor analyses of the subscales showed that the factor structure of the inventory was consistent with Cloninger's theory. Correlations of the scale scores with the General Health Questionnaire and the Social Desirability Scale scores were almost negligible, indicating that the scale is resistant to the current psychopathology and response bias. In this and the other two university student samples (ns = 395 and 377), Cronbach coefficients alpha of the scale scores were substantially high except for the short version (125 items) of the inventory with dichotomous measures. The Japanese version of the inventory appears to have internal reliability and content and construct validity in a Japanese population.

Adolescent↗
PubMed2000

[Dissecting aneurysm of the middle cerebral artery: case report].

We present a surgical case of a dissecting aneurysm of the right middle cerebral artery associated with subarachnoid hemorrhage and intracranial hemorrhage. A 61-year-old woman with consciousness disturbance and left hemiplegia was referred to our hospital. She had suffered severe headache for a week. CT scan showed a subarachnoid hemorrhage in the right Sylvian fissure and intracranial hemorrhage in the right putamen. The right carotid angiogram revealed string sign in M1 portion and occlusion at M2 lower branch of the right middle cerebral artery. On the 12th day, we undertook surgery to confirm whether it was a dissecting aneurysm or not. In the operation, it was reddish in the M1 portion corresponding to the "string sign" and dark-purplish in the lower M2 portion corresponding to an "aneurysm-like lesion". To prevent bleeding, the arterial wall in the M1 portion was coated using muscle. Though the left hemiplegia was unchanged, the postoperative course was uneventful. The patient was transferred to another hospital and underwent rehabilitation. There has been no reccurrence during the four years since surgery. The middle cerebral artery dissecting aneurysm is extremely rare. We presented this case with review of the literature.

Aortic Dissection↗
PubMed2000

Effects of vitamins A and E on superoxide production and intracellular signaling of neutrophils in Holstein calves.

The effects of vitamin A and vitamin E treatment on superoxide (O2-) production of neutrophils and their intracellular signaling, including intracellular Ca2+, protein kinase C (PKC), and tyrosine kinase (TK), were examined in Holstein calves. After treatment with vitamin A, heat-aggregated IgG (H-agg.IgG)-induced O2- production in neutrophils ranged from 3.7+/-0.4 to 4.3+/-0.9 nmol (mean +/- SD), and it was significantly (P<0.05) higher than that in the control calves. Opsonized zymosan (OPZ)-induced O2- production was similar with that of control calves. Intracellular signaling of neutrophils in vitamin A-treated calves was enhanced compared with that of control calves when stimulated with H-agg. IgG, but not with OPZ. After treatment with vitamin E, H-agg.IgG- and OPZ-induced O2- production of neutrophils ranged from 4.2+/-0.8 nmol to 5.4+/-0.5 nmol and from 7.8+/-0.6 nmol to 8.1+/-0.4 nmol (mean +/- SD), respectively, and they were significantly (P<0.05) higher than those in control calves. Intracellular signaling was also enhanced compared with that of control calves. These results suggested that the effects of vitamin A and E treatment on O2- production were correlated to changes in intracellular signaling of neutrophils in Holstein calves.

Animals↗
PubMed2000

[Whole-body oxygen consumption at different temperatures during cardiopulmonary bypass].

For evaluation of the adequacy of tissue perfusion during cardiopulmonary bypass (CPB), whole-body oxygen consumption rates at different body weights and temperatures are basic and important data. But few studies have analyzed the oxygen consumption estimated from real-time data during CPB in clinical situations. We analyzed retrospectively the oxygen consumption at different body weights (BW) during normothermia (VO2 37) and the oxygen consumption ratio at different body temperatures (BT; %VO2X; X = BT) from the CPB charts of 189 cases. From these charts, 877 data points for oxygen consumption during total CPB were calculated by Fick's law. By statistical analysis of these data, we derived the following formulae: VO2 37 (ml/kg/min) = 7.6481 x BW0.0679, R2 = 1.0 (BW < 8 kg) VO2 37 (ml/kg/min) = 32.394 x BW-0.625, R2 = 0.92 (BW > or = 8 kg) %VO2X (%) = 4 x 10(-5) x BT4.0777, R2 = 0.42. These formulae indicate that (1) the whole-body oxygen consumption during total CPB can be measured by subtracting the oxygen consumption associated with circulatory and respiratory processes from the oxygen consumption derived from the basal metabolism; and (2) although the change in oxygen consumption induced by hypothermia is variable depending on body weight, the rate of change shows no difference regardless of the patient's weight.

Body Weight↗
PubMed2000

[A case of neurocysticercosis presenting as focal seizure].

In Japan neurocysticercosis is a rare disease. We report a case of neurocysticercosis with a review of the literature. A 29-year-old man presented focal seizure on the left side. Physical and neurological findings on admission were unremarkable. CT and MRI showed a mass with ring-like enhancement and perifocal edema in the right frontal lobe, as well as multiple small masses with calcification. The main mass measuring 8 mm in diameter, was suspected as the eliptogenic focus, and was totally removed via the transcortical approach. Postsurgically seizures did not recur, and histological examination of the mass confirmed a cysticercus. A therapeutic course of albendazole and praziquantel administered postsurgically was effective for the multiple intraparenchymal masses.

Adult↗
PubMed2000

[The effect of propofol anesthesia on striatal dopamine of awake freely moving and anesthetized rats examined by in vivo microdialysis study].

We investigated the effect of propofol anesthesia on the level of interstitial dopamine in vivo awake free moving and anesthetized rats brain striatum using microdialysis techniques. Rats were implanted a microdialysis probe to right striatum of the brain and administered intravenously 20 mg.kg-1 of propofol for induction and followed by continuous infusion at 12.5, 25 and 50 mg.kg-1.hr-1 up to 1 hour. The microdialysis probe was perfused with artificial cerebrospinal fluid and dialysates from the probe were determined every 20 minutes by high performance liquid chromatography and electrochemical detection. Propofol anesthesia reduced the amount of dopamine derived from dialysate, but no prolonged increases of dopamine metabolites were observed, as we demonstrated in previous investigation for halothane, isoflurane or sevoflurane anesthesia. We hypothesize that the characteristics of propofol anesthesia for dopamine and its metabolites might contribute to low incidence of postoperative nausea and vomiting in its clinical use.

Anesthesia, Intravenous↗
PubMed1999

Mechanical and chemical properties of cysteine-modified kinesin molecules.

To probe the structural changes within kinesin molecules, we made the mutants of motor domains of two-headed kinesin (4-411 aa) in which either all the five cysteines or all except Cys45 were mutated. A residual cysteine (Cys45) of the kinesin mutant was labeled with an environment-sensitive fluorescent probe, acrylodan. ATPase activity, mechanical properties, and fluorescence intensity of the mutants were measured. Upon acrylodan-labeled kinesin binding to microtubules in the presence of 1 mM AMPPNP, the peak intensity was enhanced by 3.4-fold, indicating the structural change of the kinesin head by the binding. Substitution of cysteines decreased both the maximum microtubule-activated ATPase and the sliding velocity to the same extent. However, the maximum force and the step size were not affected; the force produced by a single molecule was 6-6.5 pN, and a step size due to the hydrolysis of one ATP molecule by kinesin molecules was about 10 nm for all kinesins. This step size was close to a unitary step size of 8 nm. Thus, the mechanical events of kinesin are tightly coupled with the chemical events.

2-Naphthylamine↗