Biomedical subjects

H Fukuda

Publications and source records attributed to H Fukuda.

At least 325 records · Page 18Linked to original sources

PubMed1998

Posteroinferior acromioclavicular dislocation with supraspinatus tear. A case report.

A 20-year-old man was treated for posteroinferior acromioclavicular dislocation. The diagnosis was based on standard radiographs and intraoperative findings. The distal end of the clavicle had impaled the supraspinatus muscle. Open reduction was performed 2 weeks after injury, followed by wire fixation of the acromioclavicular joint and repair of the torn superior acromioclavicular ligament and coracoclavicular ligaments. Two years after the procedure, standard radiographs revealed normal anatomic alignment of the acromioclavicular joint, with pain free range of motion. Active elevation in the scapular plane was 180 degrees, active external rotation was 80 degrees in the anatomic position, and passive internal rotation was to the T5 vertebra. The patient returned to playing baseball and tennis and was satisfied with the postoperative result.

Acromioclavicular Joint↗

PubMed1998

An image analyzing system using an artificial neural network for evaluating the parenchymal echo pattern of cirrhotic liver and chronic hepatitis.

To objectively evaluate the parenchymal echo pattern of cirrhotic liver and chronic hepatitis, we applied an image analyzing system (IAS) using a neural network. Autopsy specimens in a water tank (n = 13) were used to examine the relationship between the diameter of the regenerative nodule and the coarse score (CS) calculated by IAS. CS was significantly correlated with the diameter of the regenerative nodule (p < 0.0001, r = 0.966). CS is considered to be useful for evaluating the coarseness of the parenchymal echo pattern.

Hepatitis, Chronic↗

PubMed1998

Dose-related cardiovascular effects of amrinone and epinephrine in reversing bupivacaine-induced cardiovascular depression.

BACKGROUND: To ascertain the efficacy of amrinone and epinephrine in reversing bupivacaine-induced cardiovascular depression, we investigated the time course of recovery of cardiac function with 3 doses of both agents after bupivacaine administration. METHODS: In sevoflurane-anaesthetized dogs, bupivacaine was infused intravenously at 1 mg.kg-1.min-1 until mean arterial pressure fell to 60 mmHg or less. The 3 doses of amrinone (1, 2, and 4 mg.kg-1) or the 3 doses of epinephrine (2, 5, and 10 micrograms.kg-1) were administered as a bolus in randomized order in each dog. RESULTS: Amrinone improved maximum left ventricular dP/dt, a time constant of left ventricular isovolemic relaxation and cardiac index persistently and dose-relatedly. Amrinone increased heart rate and decreased left ventricular end-diastolic pressure and systemic vascular resistance index. Amrinone at 1 and 2 mg.kg-1 significantly increased mean arterial pressure, but amrinone at 4 mg.kg-1 did not. Epinephrine increased mean arterial pressure, maximum left ventricular dP/dt, and systemic vascular resistance dose-relatedly. The duration of action of epinephrine, peaking at 1 min and subsequently decreasing by 10 min after administration, did not differ among the groups. Epinephrine at all doses failed to improve a time constant of left ventricular isovolemic relaxation and cardiac index. ECG evidence of serious ventricular dysrhythmias was seen in 1 out of 6 dogs after administrating each dose of amrinone and in 3, 3 and 5 out of 6 dogs after administrating 2, 5 and 10 micrograms.kg-1 of epinephrine, respectively. CONCLUSION: Bolus amrinone may have a certain efficacy in reversing bupivacaine-induced cardiovascular depression, and improving cardiac contractility and relaxation dose-relatedly. In contrast to amrinone, bolus epinephrine remains indispensable for resuscitation, causing a rapid, massive, transient and dose-related rise in blood pressure. However, the use of amrinone may be limited predominantly by a decrease in systemic vascular resistance, while the use of epinephrine may be limited predominantly by the generation of serious ventricular dysrhythmias and lack of effectiveness on cardiac index and on cardiac relaxation.

Amrinone↗

PubMed1998

Regional cerebral blood flow abnormalities in late-life depression: relation to refractoriness and chronification.

We examined patterns of regional cerebral blood flow (rCBF) abnormalities in 18 patients with major depressive disorder in late life using single photon emission computed tomography (SPECT) and 99mTc-hexamethylpropylenamine oxime (99mTc-HMPAO). Compared with 13 age-matched controls, relative rCBF was significantly decreased bilaterally in the anterior cingulate gyrus, the prefrontal cortex, the temporal cortex, the parietal cortex, the hippocampus and the caudate nucleus. However, it was not correlated with the severity of depression or global cognitive dysfunction. In 10 patients with a prolonged depressive episode or prolonged residual symptoms (the refractory subgroup), robust and extensive decreases in rCBF were found compared with controls and the rCBF decreased significantly in the anterior cingulate gyrus and the prefrontal cortex compared with that in the non-refractory subgroup. In the non-refractory subgroup, rCBF decreased significantly in the caudate nucleus and tended to decrease in the anterior cingulate gyrus compared with controls. These findings indicate that dysfunction of the limbic system, the cerebral association cortex and the caudate nucleus may be implicated in late-life depression and that robust and extensive hypoperfusion, especially in the anterior cingulate and the prefrontal regions, may relate to refractoriness or chronification of depression.

Aged↗

PubMed1998

Alcohol effect on sleep electroencephalography by fast Fourier transformation.

The influence of alcohol (ethanol) on sleep was investigated in 10 men. Polysomnography (PS) was recorded on a baseline night (BL-N) and an ethanol (0.8 g/kg) night (Et-N). On visual score rapid eye movement (REM) sleep was reduced, REM latency was prolonged on Et-N as compared to BL-N. Using the fast Fourier transformation method, electroencephalographic power density of REM sleep in delta frequencies band and in the 10-12 Hz range of non-REM sleep were enhanced. REM sleep and non-REM sleep changes were prominent in the second-half and first-half of the night, respectively.

Adult↗

PubMed1998

A case of subwakefulness syndrome.

We report a patient, a 30-year-old male Japanese-Brazilian migrant construction worker, suffering from excessive daytime sleepiness for at least 6 months. Electroencephalogram recordings during his waking states showed that 10-Hz and 60-microV alpha activity was present prominently in the occipital regions. From the multiple sleep latency test, it was found that stages 1-2 NREM sleep episodes appeared repetitively without any REM episodes, and that the mean sleep latency was 10.2 min. These findings support the diagnosis that this patient suffers from subwakefulness syndrome.

Adult↗

PubMed1998

Inhibitory activities of gatifloxacin (AM-1155), a newly developed fluoroquinolone, against bacterial and mammalian type II topoisomerases.

We determined the inhibitory activities of gatifloxacin against Staphylococcus aureus topoisomerase IV, Escherichia coli DNA gyrase, and HeLa cell topoisomerase II and compared them with those of several quinolones. The inhibitory activities of quinolones against these type II topoisomerases significantly correlated with their antibacterial activities or cytotoxicities (correlation coefficient [r] = 0.926 for S. aureus, r = 0.972 for E. coli, and r = 0.648 for HeLa cells). Gatifloxacin possessed potent inhibitory activities against bacterial type II topoisomerases (50% inhibitory concentration [IC50] = 13.8 microg/ml for S. aureus topoisomerase IV; IC50 = 0.109 microg/ml for E. coli DNA gyrase) but the lowest activity against HeLa cell topoisomerase II (IC50 = 265 microg/ml) among the quinolones tested. There was also a significant correlation between the inhibitory activities of quinolones against S. aureus topoisomerase IV and those against E. coli DNA gyrase (r = 0.969). However, the inhibitory activity against HeLa cell topoisomerase II did not correlate with that against either bacterial enzyme. The IC50 of gatifloxacin for HeLa cell topoisomerase II was 19 and was more than 2,400 times higher than that for S. aureus topoisomerase IV and that for E. coli DNA gyrase. These ratios were higher than those for other quinolones, indicating that gatifloxacin possesses a higher selectivity for bacterial type II topoisomerases.

Anti-Infective Agents↗

PubMed1998

Antibacterial activity of gatifloxacin (AM-1155, CG5501, BMS-206584), a newly developed fluoroquinolone, against sequentially acquired quinolone-resistant mutants and the norA transformant of Staphylococcus aureus.

Alternate mutations in the grlA and gyrA genes were observed through the first- to fourth-step mutants which were obtained from four Staphylococcus aureus strains by sequential selection with several fluoroquinolones. The increases in the MICs of gatifloxacin accompanying those mutational steps suggest that primary targets of gatifloxacin in the wild type and the first-, second-, and third-step mutants are wild-type topoisomerase IV (topo IV), wild-type DNA gyrase, singly mutated topo IV, and singly mutated DNA gyrase, respectively. Gatifloxacin had activity equal to that of tosufloxacin and activity more potent than those of norfloxacin, ofloxacin, ciprofloxacin, and sparfloxacin against the second-step mutants (grlA gyrA; gatifloxacin MIC range, 1.56 to 3.13 microg/ml) and had the most potent activity against the third-step mutants (grlA gyrA grlA; gatifloxacin MIC range, 1.56 to 6.25 microg/ml), suggesting that gatifloxacin possesses the most potent inhibitory activity against singly mutated topo IV and singly mutated DNA gyrase among the quinolones tested. Moreover, gatifloxacin selected resistant mutants from wild-type and the second-step mutants at a low frequency. Gatifloxacin possessed potent activity (MIC, 0.39 microg/ml) against the NorA-overproducing strain S. aureus NY12, the norA transformant, which was slightly lower than that against the parent strain SA113. The increases in the MICs of the quinolones tested against NY12 were negatively correlated with the hydrophobicity of the quinolones (correlation coefficient, -0.93; P < 0.01). Therefore, this slight decrease in the activity of gatifloxacin is attributable to its high hydrophobicity. Those properties of gatifloxacin likely explain its good activity against quinolone-resistant clinical isolates of S. aureus harboring the grlA, gyrA, and/or norA mutations.

Anti-Infective Agents↗

PubMed1998

A neurokinin-1 receptor antagonist reduced hypersalivation and gastric contractility related to emesis in dogs.

The roles of tachykinin neurokinin-1 (NK1) receptors in the induction of fictive retching, hypersalivation, and gastric responses associated with emesis induced by abdominal vagal stimulation were studied in paralyzed, decerebrated dogs. Vagal stimulation induced gradual increases in salivary secretion and activity of the parasympathetic postganglionic fibers to the submandibular gland, relaxation of the gastric corpus and antrum, and fictive retching. However, hypersalivation and increased nerve activity were suppressed and antral contractility was enhanced during fictive retching. An NK1 receptor antagonist, GR-205171, abolished the enhancement of antral contractility and fictive retching but had no effect on corpus and antral relaxation. Hypersalivation and increased nerve activity were inhibited by GR-205171 but were not completely abolished. Reflex salivation by lingual nerve stimulation was unaffected. These results suggest that GR-205171 acts on the afferent pathway in the bulb and diminishes hypersalivation and antral contraction related to emesis as well as fictive retching but does not affect gastric relaxation or hypersalivation induced by the vagovagal, vagosalivary, and linguosalivary reflexes.

Animals↗

PubMed1998

PET study of pointing with visual feedback of moving hands.

This study was conducted to determine where in the human brain visual feedback of hand movements is processed to allow accurate pointing. Regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET) and H2 15O in nine normal volunteers while performing one control and two reaching tasks. In all tasks, visual stimuli were presented on a head mounted display (HMD). A target board was placed in front of the subjects bearing six red light-emitting diodes (LEDs) aligned on a circle with a green LED at its center. The center green LED and one of the six red LEDs, randomly selected, were repeatedly switched on and off, alternatively. In the control task, subjects were instructed to gaze at the lit LED. In the two reaching tasks, the reaching with visual feedback (RwithF) task and the reaching without visual feedback (RwithoutF) task, they had to point to the lit red LED with their right index fingers. In the RwithF task, their right hands were visible on the HMD before touching the target, whereas in the RwithoutF task, they were not visible. For each subject, subtraction images of each reaching task minus the control and the RwithF task minus the RwithoutF task were calculated after transformation of PET images into the standard brain shape with an adjustable computerized brain atlas. These subtraction rCBF images were then averaged among the subjects, and significant changes of rCBF were identified. Significant increases in rCBF not only in the RwithF task minus control image but also in the RwithF task minus the RwithoutF task image were observed in the supramarginal cortex, the premotor cortex and the posterior cingulate cortex of the left hemisphere, the caudate nucleus and the thalamus of the right hemisphere, and the right cerebellum and vermis. These results indicate that the supramarginal cortex, the premotor cortex, and the posterior cingulate cortex of the left hemisphere and the cerebellum are involved in integrating visual feedback of hand movements and execution of accurate pointing.

Adult↗

PubMed1998

Visualization of the information flow through human oculomotor cortical regions by transcranial magnetic stimulation.

We investigated the topography of human cortical activation during an antisaccade task by focal transcranial magnetic stimulation (TMS). We used a figure-eight shaped coil, with the stimulus intensity set just above the threshold for activation of the hand motor areas but weak enough not to elicit blinks. TMS was delivered at various time intervals (80, 100, and 120 ms) after target presentation over various sites on the scalp while the subjects performed the antisaccade task. It was possible to elicit a mild but significant delay in saccade onset over 1) the frontal regions (a region 2-4 cm anterior and 2-4 cm lateral to hand motor area) and 2) posterior parietal regions (6-8 cm posterior and 0-4 cm lateral to hand motor area) regardless of which hemisphere was stimulated. The frontal regions were assumed to correspond to a cortical region including the frontal eye fields (FEFs), whereas the parietal regions were assumed to represent a wide region that includes the posterior parietal cortices (PPCs). The regions inducing the delay shifted from the posterior parietal regions at an earlier interval (80 ms) to the frontal regions at a later interval (100 ms), which suggested an information flow from posterior to anterior cortical regions during the presaccadic period. At 120 ms, the effect of TMS over the frontal regions still persisted but was greatly diminished. Erroneous prosaccades to the presented target were elicited over a wide cortical region including the frontal and posterior parietal regions, which again showed a forward shift with time. However, the distribution of effective regions exhibited a clear contralateral predominance in terms of saccade direction. Our technique provides a useful method not only for detecting the topography of cortical regions active during saccadic eye movement, but also for constructing a physiological map to visualize the temporal evolution of functional activities in the relevant cortical regions.

Adult↗

PubMed1998

Lubrication mechanism of the larynx during phonation: an experiment in excised canine larynges.

To evaluate how the viscosity of the laryngeal mucus influences vocal fold vibration, two fluids of differing viscosity were applied separately to excised canine larynges and experimental phonation was induced. Vibration of the vocal folds was measured by use of a laryngostroboscope and an X-ray stroboscope. With the high viscosity fluid, the amplitude of vibration of the free edge and the peak glottal area was decreased while the open quotient was increased. Because the viscosity of this fluid affected the wave motion of the vocal fold mucosa, changes in viscosity of the mucus may be involved in causing such disorders as hoarseness, in the absence of apparent changes in the vocal folds themselves.

Animals↗

PubMed1998

Observations of laryngeal lesions with a rhinolarynx electronic videoendoscope system and digital image processing.

Laryngeal lesions were observed with the Olympus ENF-200 rhinolarynx electronic videoendoscope attached to the Olympus EVIS-200 system, an electronic videoendoscope system of Olympus Optical Co, Ltd. The electronic videoendoscope differs from conventional flexible fiberscopes in having a small light-sensitive charge-coupled device (CCD) chip built into the tip of the endoscope portion. This model has a small CCD chip in its 5-mm-outer diameter tip, and can be introduced into the laryngeal cavity by inserting it through the nasal passages. Dynamic color images obtained by this system were very clear and provided excellent resolution. This electronic videoendoscope system could also be connected to the Olympus EVIP-230 digital image processor, which was compatible with this system. Structure enhancement and color enhancement were performed by processing images. In this paper, the ordinary images and the processed images are described and discussed from the standpoint of diagnostic usefulness.

Equipment Design↗

PubMed1998

Prevalence of intellectual dysfunctioning and its correlates in a community-residing elderly population.

To examine the prevalence of intellectual dysfunctioning and its correlates in community-residing elderly people, a randomly selected sample of 1,405 people aged 65 and over living in Settsu, Osaka, were investigated in October 1992. Data for assessing intellectual dysfunctioning were obtained from 1,364 people (97.1%), excluding 21 clinically demented people (1.5%); 17.6/100, 5.6/100, and 3.3/100 of the population showed minor, moderate, and appreciable intellectual dysfunctioning, respectively, and the prevalence of intellectual dysfunctioning increased with age. By multivariate analyses using logistic regression, age over 75, poor general health, including current medical treatment, and psychosocial conditions such as no participation in social activities, no life worth living (no Ikigai), and anxiety about the future were independent risk factors for intellectual dysfunctioning. We conclude that intellectual dysfunctioning is closely associated with health and psychosocial conditions.

Aged↗

PubMed1998

Construction and validation of a practical prognostic index for patients with metastatic breast cancer.

PURPOSE: To identify the readily available prognostic factors most helpful in predicting survival and to construct and validate a prognostic index for metastatic breast cancer (MBC) patients. PATIENTS AND METHODS: Data from 233 MBC patients, accrued on a multiinstitutional randomized phase III trial (Japan Clinical Oncology Group [JCOG] study 8808), were analyzed to identify significant prognostic factors and a prognostic index was constructed by incorporating these prognostic factors. For validation of the prognostic index, another data set from 315 consecutive MBC patients, who had been treated with standard anthracycline-containing regimens, was analyzed. RESULTS: In multivariate regression analyses, history of adjuvant chemotherapy (ADJCT) (P = .0005), presence of distant lymph nodes (DLNs) (P = .0117) and liver (HEP) (P = .0099) metastases, elevation of serum lactate dehydrogenase (LDH) (P < .0001), and shorter disease-free interval (DFI) (P < .0001) significantly contributed to poorer survival. The prognostic index was constructed as follows: Prognostic Index = ADJCT (not received = 0, received = 1) + DLNs (absent = 0, present = 1) + HEP (absent = 0, present = 1) + LDH (< or = one times normal = 0, > one times normal = 1) + DFI (> or = 24 months = 0, < 24 months = 2). With this prognostic index, patients could be stratified into three risk groups. The median survival times (MSTs) of low-, intermediate- and high-risk groups were 45.5, 24.6, and 10.6 months, respectively (P < .0001). This prognostic index was applied to the validation patients. The respective MSTs for each risk group were 49.6,22.8, and 10.0 months (P < .0001). CONCLUSION: ADJCT, DLNs, HEP, LDH, and DFI were important prognostic factors for MBC patients. The prognostic index readily enables MBC patients to be stratified into three risk groups and is worth considering for future clinical trials.

Analysis of Variance↗

PubMed1998

Organogenic responses in tissue culture of srd mutants of Arabidopsis thaliana.

In Arabidopsis thaliana, shoot redifferentiation and root redifferentiation can be induced at high frequency from hypocotyl and root explants by a two-step culture method. Tissues are precultured on callus-inducing medium and then transferred onto shoot-inducing medium for shoot redifferentiation or onto root-inducing medium for root redifferentiation. In an attempt to dissect these organogenic processes genetically, we characterized the responses in tissue culture of srd1, srd2 and srd3 mutants that were originally isolated as temperature-sensitive strains with defects in shoot redifferentiation (Yasutani, I., Ozawa, S., Nishida, T., Sugiyama, M. and Komamine, A. (1994) Plant Physiol. 105, 815-822). These mutants exhibited temperature sensitivity at different steps of organogenesis, which allowed the identification of three states associated with organogenic competence: IC (incompetent); CR (competent with respect to root redifferentiation); and CSR (competent with respect to shoot and root redifferentiation). Hypocotyl explants were shown to be in the IC state at the initiation of culture and to enter the CSR state, via the CR state, during preculture on callus-inducing medium, whereas root explants seemed to be in the CR state at the initiation of culture. The transition from IC to CR and that from CR to CSR appeared to require the functions of SRD2 and SRD3, respectively. It appears that explants in the CSR state redifferentiate shoots with the aid of the products of SRD1 and SRD2 when transplanted onto shoot-inducing medium. Histological examination of the srd mutants revealed that the function of SRD2 is required not only for organogenesis but also for the reinitiation of cell proliferation in hypocotyl explants during culture on callus-inducing medium. Linkage analysis using RFLP markers indicated that SRD1, SRD2, and SRD3 are located at the lower region, the central region, and the upper region of chromosome 1, respectively.

Arabidopsis↗

PubMed1998

[Pharmacology of the GABA receptor functions in the central nervous systems].

gamma-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system. GABA receptors have been classified into at least two categories, GABA(A) receptors, which are heterogeneous multimeric ligand-gated Cl channels, and GABA(B) receptors, which are coupled to G-proteins. GABA(B) receptors have not only a physiological role in synaptic transmission, but also are important in pathological conditions associated with absence epilepsy, cognitive disorders and nociception. This review describes our current knowledge of the neuropharmacology and neurochemistry of GABA(B) receptors, including their heterogeneity as well as the therapeutic potential of the drugs which interact with these sites.

Animals↗

PubMed1998

A case of variant angina pectoris with similar findings on both rest and matched exercise thallium-201 studies.

A patient with variant angina showed similar findings on both the rest and matched exercise 201Thallium (201Tl) myocardial perfusion scintigrams. The 65-year old man was admitted to hospital because of rest angina. His electrocardiogram during the attack disclosed ST segment elevation on inferior leads. However, emergency coronary arteriogram showed no fixed stenosis. Intracoronary injection of acetylcholine induced a spasm on the distal right coronary artery, but not in the left coronary artery. In the rest 201Tl study, septal perfusion was low on the early image, although partial redistribution of this site was observed on the delayed image without the appearance of chest pain or electrocardiographic ischemic change. Similary, in the 201Tl exercise study undergone 2 weeks later, septal redistribution was diagnosed because the early image had decreased septal perfusion. Both the exercise 123I-metaiodobenzylguanidine study and the rest 123I-betamethyl-p-iodophenyl-pentadecanoic acid study showed inferior abnormalities on the early and delayed images. Although a coronary spasm was not induced in the left anterior descending artery with the acetylcholine test, septal redistribution was observed on the delayed image of both the rest and exercise 201Tl studies. The mechanism of the redistribution on the rest 201Tl study was unclear.

Aged↗