Biomedical subjects

T Himi

Publications and source records attributed to T Himi.

At least 91 records · Page 5Linked to original sources

PubMed1993

Adult T-cell leukaemia-lymphoma in Waldeyer's ring: a report of three cases.

Adult T-cell leukaemia-lymphoma (ATLL) is a new type of T-cell malignancy which has an adult onset, a rapidly progressive terminal course and a clustering at patients' birthplaces in southeast Japan and the Caribbean. We report the clinical features of three cases of ATLL in Waldeyer's ring, which has been rarely reported in the literature. The patients complained of throat pain and lump in the neck. They received combination chemotherapy, but all died within a year of first noticing the symptoms.

Adult↗

PubMed1993

[A case of tuberculosis of the thyroid gland].

A 49-year-old woman was admitted to our university hospital for examination of a neck mass. Computed tomography and ultrasonography revealed a nodule in her thyroid gland and a swollen cervical lymph node. They were removed surgically; a subsequent histological study revealed an epithelioid cell granuloma. A diagnosis of localized tuberculosis of the thyroid gland and a cervical lymph node was thus confirmed. The data of the present case were discussed with reference to the characteristics of thyroid tuberculosis described in the literature.

Female↗

PubMed1993

[Quantitation of regional myocardial blood flow using continuous inhalation of C15O2 and positron emission tomography].

A C15O2 continuous inhalation and a steady-state theory using positron emission tomography (PET) have been used to quantitate regional cerebral blood flow. We extended this method for quantitative regional myocardial blood flow (RMBF) measurement. Forty-three patients, involving 4 normal volunteers, 16 patients with coronary heart disease (CHD), 20 patients with hypertrophic cardiomyopathy (HCM), and 3 patients with dilated cardiomyopathy (DCM), were studied. 6 min-scan was recorded in the steady-state condition during C15O2 continuous inhalation. A C15O inhalation scan was required to obtain the blood pool image. The subtracted image showed myocardial perfusion image. These images demonstrated homogeneous accumulation in normal volunteers. Reduced accumulation were detected in patients with myocardial infarction. Hypertrophied myocardium was demonstrated in patients with HCM. Diffuse heterogeneous accumulation was demonstrated in patients with DCM. Fourteen patients with HCM, whose left ventricular myocardial thicknesses were more than 20 mm, were selected for the RMBF measurement to minimize errors due to the partial volume effect. The arterial blood activity was measured by assigning a region of interest to the left atrial cavity on PET images. RMBF was calculated using the steady-state theory. Calculated flow values ranged from 21.2 to 152.6 ml/min/100 g. The good correlation was obtained between RMBF using 13NH3 first pass method and RMBF using gas inhalation method in six patients. These results indicate that C15O2 PET has the potential capability for the noninvasive quantitation of RMBF.

Adult↗

PubMed1992

Involvement of glycine site associated with the NMDA receptor in hippocampal long-term potentiation and acquisition of spatial memory in rats.

The effects of 7-chlorokynurenic acid (7-Cl-Kyn), a selective antagonist at the glycine site associated with the N-methyl-D-aspartate (NMDA) receptor, on hippocampal long-term potentiation (LTP) and behavioral performances in a spatial learning task were investigated. Extracellular recordings of evoked potential (population spike) were made in rat hippocampal slices. Perfusion of 7-Cl-Kyn (10(-5) M) inhibited the induction of LTP following a tetanic stimulation (51 or 101 pulses at 100 Hz) both in the Schaffer/commissural-CA1 pyramidal cell synapses and in the perforant path-dentate granule cell synapses. Acquisition of a spatial memory in the Morris water maze was examined using rats chronically cannulated for application of drugs. The intact and vehicle-injected rats learned easily to escape onto a hidden platform with short latencies, while the rats given an injection of 7-Cl-Kyn (10(-8) mol/brain, i.c.v.) prior to every session took a longer time and a longer path to escape even after all 5 sessions of trials. Injection of 7-Cl-Kyn did not affect the swimming speed, an index of swimming ability. This is the first report providing direct evidence that endogenous glycine supports the processes of learning and memory.

Animals↗

PubMed1992

Immunologic characteristics of cytokines in otitis media with effusion.

Levels of cytokines, interleukin (IL)-1 alpha, IL-1 beta, tumor necrosis factor (TNF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) were investigated in samples of the middle ear effusions (MEEs) from 144 ears with otitis media with effusion (OME) by enzyme-linked immunosorbent assay, followed by cytologic analysis. Middle ear effusions of the acute purulent type contained a significantly higher concentration of cytokines compared with normal control sera (p < .001). Cytokines were observed at lower levels in MEE in adults than in children. Tests of children at the chronic stage of MEE showed higher levels of TNF than IL-1 and GM-CSF. Meanwhile, IL-1 beta showed significantly higher concentrations in acute purulent types than in serous and mucoid types (p < .01). In cytologic analysis, the mean level of IL-1 beta was significantly higher in the neutrophil-rich group than in other groups (p < .05). Cytokines possess several biologic properties, some of which are associated not only with acute otitis media but also with chronic otitis media. This study showed that cytokines, especially IL-1 beta, contribute to infiltration into the middle ear by inflammatory cells. This implies that the persistent presence of cytokines in MEE could be a factor in prolonged OME.

Acute Disease↗

PubMed1992

[Pulmonary kinetics of 13N-ammonia in smoking subjects--a quantitative study using dynamic PET].

To evaluate the effect of smoking on nonrespiratory function in the lung, a dynamic PET with 13NH3 in the lung was performed in 18 normal volunteers without lung disease nor congestion (9 non-smokers, 4 exsmokers, 5 smokers). After intravenous bolus injection of 13NH3, twenty serial 5.5-second scans followed by six 30-second scans were performed. Regions of interests were assigned on the ventral, lateral and dorsal part of the right lung and time-activity curves were generated through 26 images. The activity curve demonstrated a biexponential clearance from the lung with fast and slow component. The retention fraction (RF), fractional size of the slow component, was calculated, and the half-times (t 1/2) of both components were also evaluated. A significant increase of RF and prolongation of t 1/2 of slow component were observed in smokers compared to non-smokers and exsmokers. However, no significant difference of RF nor t 1/2 of both components was observed between non-smokers and exsmokers. These results suggest that long term smoking may modify the pulmonary kinetics of 13NH3, but the change is reversible after cessation of smoking for one year or longer.

Adult↗

PubMed1990

The effect of saccular ablation on vertical optokinetic after-nystagmus in squirrel monkeys.

The effect of bilateral saccular ablation on the asymmetry of vertical optokinetic after-nystagmus (OKAN) was studied in squirrel monkeys. No significant changes occurred in the initial slow-phase eye velocity (SPEV) or the time constant of the upward or downward OKAN first phase (OKAN-I) under various stimulus conditions. However, with a protracted downward stimulus, the maximum SPEV and the number of beats of the slow-phase-up OKAN second phase (OKAN-II) significantly increased. This increase should be the result from enhancement of the downward optokinetic input. In contrast, there was only minimal change in the slow-phase-down OKAN-II. Thus, the asymmetrical dominance of the vertical OKAN (dominance upward) remained the same after saccular deafferentation.

Animals↗

PubMed1990

Spider toxin (JSTX-3) inhibits the memory retrieval of passive avoidance tests.

The effect of a spider toxin (JSTX-3)--a specific blocker of quisqualate sensitive type of glutamate receptors--on learning and memory was studied in mice using passive avoidance tests (step-through and step-down tests) and the water maze test. JSTX-3 was injected into lateral ventricles of chronically cannulated mice at a dose of 22.2 pmol/brain, which did not produce any apparent behavioral changes. This chemical significantly impaired the retrieval of memory in the step-through test and showed a similar (though not statistically significant) tendency in the step-down test, but it had no effect on acquisition or consolidation of memory in both tests. In the water maze test, this chemical had no effect on escape latencies.

Animals↗

PubMed1990

Spider toxin (JSTX-3) inhibits the convulsions induced by glutamate agonists.

The effect of a spider toxin (JSTX-3)--a specific blocker of glutamate receptors--on the behavior of mice was studied using an intracerebroventricular (i.c.v.) injection technique. At higher doses (more than 12 nmol/brain), JSTX-3 increased motor activities and induced characteristic symptoms. JSTX-3 at a dose of 4.7 nmol/brain which per se did not produce any abnormal behavior, specifically antagonized quisqualate-induced convulsions but not NMDA- or kainate-induced convulsions. These results indicate that JSTX-3 is a selective antagonist of the quisqualate receptors in the mammalian central nervous system.

Animals↗

PubMed1990

Autonomic indexes during the vestibular-visual conflict exposure: a squirrel monkey study.

To assess the dynamic changes of the autonomic neural responses evoked by vestibular-visual conflict (VVC) in the squirrel monkey, we analyzed the changes of salivary amount and sodium concentration, and the coefficient of variance (CV) of R-R intervals (RRI) along the time course of VVC exposure given in pitch plane. The sodium concentration and the amount of saliva showed clear increases at the first and second 15 min stimulation periods. The CV of RRI was found to increase over the entire periods of stimulation, and there was a significant difference between the rest value and those in stimulated periods. The correlation between the CV of RRI, and amount of salivation was highly positive. These results indicate the existence of a common pattern of autonomic neural response during VVC, and suggest usefulness of these indexes for objectively monitoring the severity of motion sickness.

Animals↗

PubMed1990

[Measurement of myocardial blood flow using N-13 ammonia dynamic PET-theory and methodology].

Positron emission tomography (PET) offers the potential capability of noninvasive measurement of regional myocardial blood flow (RMBF) in man. Because N-13 ammonia exhibits properties which to some extent resemble those of the radioactive microsphere, we developed a first-pass flow method for noninvasive measurement of RMBF. In the present method, RMBF was determined by dividing myocardial activity at time T by arterial input integrated from the injection start to that time, where time T is the endpoint of first circulation of N-13 ammonia. Also in the present method a time-activity curve of left atrium was used as the arterial input function to make the procedure totally noninvasive. To validate the present method, we compared it with the compartment analysis. 5 patients with hypertrophic cardiomyopathy (HCM) and with a considerably thickened ventricular wall, were selected for the comparison between the first-pass flow method and the compartment analysis. The relationship of RMBFs by the two methods was y = 1.8 + 1.097x-0.002037x2 (n = 30, SEE = 5.5), where x (ml/min/100 g) was obtained by the compartment analysis, while y (ml/min/100 g) by the first-pass flow method. The result indicated that both were almost identical in physiological flow range (less than 100 ml/min/100 g), but that the first-pass flow method underestimated RMBF in the higher flow range due to venous leakage of N-13 ammonia. As the conclusion, we could at least measure RMBF of HCM patient in the physiological flow range by the present method. The future extension of the method was discussed.

Ammonia↗

PubMed1990

[PET assessment of myocardial viability with glucose loading and fasting FDG images].

Positron emission tomography (PET) offers the potential capability of evaluating tissue viability. We have studied the changes of myocardial F-18 deoxyglucose (FDG) uptake with glucose loading. In a fasting state (for at least 5 hours) and in a glucose loading state (50 g glucose orally one hour before the study) FDG (74-148 MBq) PET studies were performed for 50-60 minutes in 3 cases. 2 were subjects with anterior myocardial infarction (MI) including one with a ventricular aneurysm (case 1), one with a recent MI (case 2). One was a subject of aortic valvular disease without coronary lesions (case 3). Arterial input function (Ca(t)) and myocardial activity (Cm(t)) were derived from the regions of interest (ROI) on the left atrium and from multiple ROI's circumferentially about the myocardium. Net extraction, FU (Fractional Uptake) = Cm(T)/integral of T0 Ca(t)dt, were calculated. Normal segment (N) showed an increase in FU with glucose loading, but the ischemic segment showed no increase (case 1) or a lower increase (case 2) relative to N. This study shows that the increase in FU with glucose loading suggests the persistence of viable myocardium. In conclusion, myocardial viability may be evaluated by comparing FDG images in a glucose loading state with those in a fasting state.

Adult↗

PubMed1989

Retinobenzoic acids. 3. Structure-activity relationships of retinoidal azobenzene-4-carboxylic acids and stilbene-4-carboxylic acids.

Alkyl-substituted azobenzene-4-carboxylic acids are potent differentiation inducers of human promyelocytic leukemia cell line HL-60 to mature granulocytes. Their structure-activity relationships are very similar to those of other retinoidal benzoic acids which are generally represented by 4 and named retinobenzoic acids. The structure-activity relationships of azobenzenecarboxylic acids can also be applied to the known retinoid TTNPB (3). Thus, (E)-4-[2-(3,4-diisopropylphenyl)-1-propenyl]benzoic acid (St30 (28] and (E)-4-[2-(3-tert-butylphenyl)ethenyl]benzoic acid (St40 (29], the acyclic alkyl analogues of TTNPB, are nearly as active as retinoic acid. Among the oxidatively derived compounds (Az90, Ep series and Ox series) of azobenzene- or stilbenecarboxylic acids, Az90 (71) and Ep80 (61) have strong activities. However, all the bishydroxylated derivatives of TTNPB are inactive, while a diketo analogue Ox580 (69) has only weak potency. The activities of conformationally restricted compounds of TTNPB offer some information on the stereochemistry of the active form of these retinoidal compounds.

Benzoates↗

PubMed1989

Retinobenzoic acids. 4. Conformation of aromatic amides with retinoidal activity. Importance of trans-amide structure for the activity.

N-Methylation of two retinoidal amide compounds, 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]benz oic acid (3, Am80) and 4-[[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2- naphthalenyl)carbonyl]amino]benzoic acid (5, Am580), resulted in the disappearance of their potent differentiation-inducing activity on human promyelocytic leukemia cell line HL-60. Studies with 1H NMR and UV spectroscopy indicated that large conformational differences exist between the active secondary amides and the inactive N-methyl amides. From a comparison of the spectroscopic results of these amides with those of stilbene derivatives, the conformations of the active amides are expected to resemble that of (E)-stilbene, whereas the inactive amides resemble the Z isomer: 3 (Am80) and 5 (Am580) have a trans-amide bond and their whole structures are elongated, while the N-methylated compounds [4 (Am90) and 6 (Am590)] have a cis-amide bond, resulting in the folding of the two benzene rings. These structures in the crystals were related to those in solution by 13C NMR spectroscopic comparison between the two phases (solid and solution).

Amides↗

PubMed1989

Effect of ginseng saponins on the survival of cerebral cortex neurons in cell cultures.

The effects of nerve growth factor (NGF) and saponins isolated from Panax ginseng C.A. Mayer on the survival of chick and rat embryonic cerebral cortex neurons were examined. Ginsenoside Rg1 (GRg1) exerted a survival-promoting effect on both chick and rat cerebral cortex neurons in cell cultures. Ginsenoside Rb1 (GRb1) also had an effect in the rat and displayed some influence in the chick. NGF alone exerted no effect on both neurons, although it did potentiate the GRb1 effect on chick embryonic cerebral cortex neurons, but did not alter the GRb1 effect on rat embryonic cerebral cortex neurons. NGF did not alter the survival-promoting effect of GRg1 on either chick or rat embryonic cerebral cortex neurons. The other saponins alone or with NGF exerted no effect on the survival of cerebral cortex neurons in either the chick or rat.

Animals↗

PubMed1989

Second-phase optokinetic after-nystagmus and vestibular compensation.

To evaluate the direction-specific effect of optokinetic storage function on balance compensation after unilateral labyrinthectomy, squirrel monkeys (n = 12) were exposed to a prolonged (30 min) daily optokinetic stimulus (horizontal, constant speed-90 degrees/sec) for 14 days; either in the ipsilateral direction to the slow phase of spontaneous nystagmus, or in the contralateral direction, or without any optokinetic stimulus. The effect of optokinetic stimulus in ipsilateral direction (slow phase of OKAN-II in the opposite direction) was significantly more (p less than 0.001) in the vestibulo-oculomotor balance (static) regainment than the other two groups, but this group showed the severest gait deviation in the vestibulospinal balance function (p less than 0.05).

Adaptation, Physiological↗

PubMed1989

Measurement of regional myocardial blood flow in hypertrophic cardiomyopathy: application of the first-pass flow model using [13N]ammonia and PET.

Positron emission tomography (PET) has become an important tool in the study of regional myocardial blood flow. The purpose of the present study was to measure regional myocardial blood flow using dynamic [13N]ammonia PET and the first-pass flow model. Thirteen patients with hypertrophic cardiomyopathy, and with a considerably thickened ventricular wall (25 mm or greater), were selected for the study in order to minimize errors due to spillover of radioactivity from blood to the myocardium and to the underestimation of myocardial activity caused by the partial volume effect. Arterial input function was determined by assigning a region of interest to the left atrial cavity on the PET images. Using left atrial and myocardial time-activity curves, regional myocardial blood flow was calculated using the first-pass flow model. Mean myocardial blood flow ranged from 47.8 to 76.5 ml/min per 100 g (63.0 +/- 9.4). Regional myocardial blood flow in the septum was significantly lower than in the anterior and lateral walls of the left ventricle (P less than .01). These results indicate the potential usefulness of dynamic PET in the measurement of regional myocardial blood flow in man.

Adult↗

PubMed1988

Soluble immune complexes and squamous cell carcinoma-related antigens in patients with head and neck cancer.

Sera from 85 patients with head and neck cancer including laryngeal cancer, hypopharyngeal cancer, nasopharyngeal cancer, and maxillary cancer were assayed for immune complexes (IC) by solid-phase anti-C3 enzyme immunoassay and for squamous cell carcinoma-related (SCC) antigen by radioimmunoassay. The positive rates of IC and SCC antigen in head and neck cancer patients were 29.4% and 34.1%, respectively. Their serum levels and positive rates were found to be elevated according to the degree of advancement of the disease stage, showing their good clinical correlations. With individual patients there was no significant relationship between IC and SCC antigen.

Adolescent↗