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Biomedical subjects

H Fukuda

Publications and source records attributed to H Fukuda.

At least 1,369 records · Page 76Linked to original sources
PubMedDate not supplied

Left ventricular volumes, ejection fraction, and regional wall motion calculated with gated technetium-99m tetrofosmin SPECT in reperfused acute myocardial infarction at super-acute phase: comparison with left ventriculography.

BACKGROUND: Noninvasive assessment of acute myocardial infarction (AMI) requires information about both myocardial perfusion and left ventricular (LV) function. The automated quantification of electrocardiographic-gated myocardial scintigraphy with technetium-99m tetrofosmin (QGS) can provide this information. METHODS AND RESULTS: Coronary arteriography, QGS, and left ventriculography (LVG) were performed in 229 patients with reperfused AMI within 2 days after onset. All infarcted vascular territories (229 segments) were visualized with scintigraphic perfusion images. The mean wall motion score (WMS) was 15.9+/-2.8 by means of QGS and 16.3+/-2.9 by means of LVG. The correlation between WMS obtained by means of QGS and that obtained by means of LVG was close (y = 0.913x + 1.016, r = 0.94, P<.001), but that obtained by means of QGS was significantly lower than that obtained by means of LVG (P<.0001). Total agreement for the assessment of regional wall motion reached 75 % (kappa, 0.66). Although the LV values obtained by means of QGS and LVG correlated well (end-diastolic volume, r = 0.67, P<.0001; end-systolic volume, r = 0.79, P<.0001; ejection fraction, r = 0.78, P<.0001), end-diastolic volume and ejection fraction tended to be underestimated with QGS. CONCLUSION: QGS data were considered to be useful in detecting infarcted vascular territory and LV function, even in AMI, within 2 days after onset.

Adult↗
PubMedDate not supplied

CT and MR appearances of splenic hamartoma.

The MR and CT appearances of two cases of splenic hamartoma are presented. Computed tomography showed a well demarcated low-density mass without calcification. Dense spreading enhancement was seen in one case on dynamic CT, and prolonged enhancement was noted in both. The masses were demonstrated as areas of isointensity on T1-weighted MR images and of high intensity on T2-weighted images. On gadolinium-enhanced T1-weighted images they were shown as areas of high intensity. Prolonged enhancement on postcontrast CT and MR imaging was a useful finding in differentiation of splenic hamartoma from malignant lesions of the spleen, especially from nodular lesions of malignant lymphoma.

Adult↗
PubMedDate not supplied

Measurement of arterial tracer concentrations from cardiac PET images.

OBJECTIVE: Cardiac PET imaging offers the potential capability for the noninvasive measurement of arterial input function. This capability is somewhat limited, however, because of partial volume and spillover effects. The purpose of this study was to validate arterial tracer concentration measurements using PET images by assigning a region of interest (ROI) to the left ventricle, left atrium (LA), and ascending aorta. MATERIALS AND METHODS: We selected [11C]CO and [13N]ammonia as tracers, because the activity of [11C]CO is primarily in the blood pool and that of [13N]ammonia primarily in myocardial tissue. Six [11C]CO and 11 [13N]ammonia PET scans were obtained in 17 subjects. Arterial tracer concentrations determined by PET were compared with those measured by well counting of arterial blood sampling obtained at the midpoint of each image acquisition. RESULTS: Arterial tracer concentrations as determined by LA-PET imaging correlated closely with those measured by blood sampling (r = 0.996, slope = 1.00 for [11C]CO; r = 0.841, slope = 0.974 for [13N]ammonia). Partial volume and spillover effects were minimized by assigning an ROI to the LA. CONCLUSION: Arterial tracer concentrations can be measured noninvasively with cardiac PET.

Adolescent↗
PubMedDate not supplied

Analysis of time-density curves of contrast media for improvement of chest dynamic incremental CT.

PURPOSE: The goal of this work was to analyze time-density curves (TDCs) of contrast media (CM) in the mediastinal vasculature to optimize chest dynamic incremental CT. METHOD: Forty-three patients were injected with nonionic CM into the forearm veins with injection rates (ml/s), durations (s), and total amounts (ml) of 2.0, 20, and 40 (protocol 1); 4.0, 20, and 80 (protocol 2); and 2.0, 40, and 80 (protocol 3). TDCs were obtained for the pulmonary trunk (PA) and ascending (AA) and descending (DA) aorta from dynamic scans. Areas under the curves (AUCs) of TDCs for imaginary 30 s scans were evaluated. RESULTS: AUC peaks were obtained after 10, 17, and 19 s (PA, AA and DA; protocol 1; 9, 16, and 18 s (protocol 2); and 18, 25, and 28 s (protocol 3) delay time. CONCLUSION: Better chest dynamic incremental CT would be expected with scan midpoints a little after the end of injection of CM.

Adult↗
PubMedDate not supplied

Effect of macular and peripheral retina coagulation on photosensitive epilepsy in the forebrain bisected baboon, Papio papio.

The effects of macular and peripheral retina coagulation were examined in photosensitive baboons, Papio papio (PP), with or without forebrain bisection. The temporal part of the macula and surrounding retina of the left eye were coagulated with an Argon laser and later confirmed histologically. In forebrain nonbisected baboons, intermittent light stimulation of the operated eye produced bisymmetrical and bisynchronous spikes and waves and self-sustained seizures. In forebrain-bisected baboons intermittent light stimulation of the operated eye produced spikes and waves and self-sustained seizures localized to the contralateral hemisphere. Subsequent stimulation of the nonoperated eye in the same animal produced spikes and waves and seizures either bilaterally or only in the opposite hemisphere when stimulation took place during the postictal silent period in the first hemisphere. In both cases, the tonic phase of the seizure was always bilateral but asymmetrical as shown by electromyographic recordings. Based on these data, it has been hypothesized that the tonic phase is mediated, in part, through crossed interreticular pathways, by one or both cerebral hemispheres. However, data are also compatible with a possible origin of the tonic phase of the seizure being partly localized in the medial frontal cortex. Results demonstrated (1) the usefulness of laser coagulation of the temporal portion of the macula and retina for the study of the functional independence between two cerebral hemispheres, (2) the critical role of the corpus callosum (CC) in bisynchronization and generalization of the intermittent light stimulation (ILS)-induced seizure, (3) independent excitability of each cerebral hemisphere by the ILS, and (4) the critical role of cortical visual afferents for inducing epileptic phenomena in this species.

Animals↗
PubMedDate not supplied

Relative biological effectiveness (RBE) of thermal neutron capture therapy of cultured B-16 melanoma cells preincubated with 10B-paraboronophenylalanine.

An experimental study of the relative biological effectiveness (RBE) of thermal neutron capture therapy (TNCT) for melanoma cell inactivation using 10B1-paraboronophenylalanine (10B1-BPA) was carried out to demonstrate a high therapeutic effect of TNCT, compared with that of fast neutron. Cells preincubated with or without 10B1-BPA at a concentration of 50 micrograms/ml for 20 h were irradiated with 60Co gamma-ray, fast neutron or thermal neutron. The absorbed dose of the cells from thermal neutron was calculated by Kobayashi's model. The D0 value of fast neutron was 1.07 Gy, and the D0S of thermal neutron radiation with or without preincubation of the cells with 10B1-BPA were 0.46 Gy or 0.67 Gy, respectively. The RBEs of fast neutron, thermal neutron beams, and neutron capture therapy relative to 60Co gamma-ray were calculated as 2.78, 4.18, and 6.15 at 0.1 surviving fraction, respectively. These results indicate radiologically that thermal neutron capture therapy using 10B1-BPA is an excellent radiation therapy for malignant melanoma.

Animals↗
PubMedDate not supplied

Review: biological effectiveness of thermal neutrons and 10B(n,alpha)7Li reaction on cultured cells.

There are only a few reports on the relative biological effectiveness (RBE) of thermal neutrons and 10B(n,alpha)7Li reactions either in vitro or in vivo. The data in this paper summarize almost all previously published in vitro data. Because only a few reactors are available for biomedical purposes, it is difficult to make a comparison of data from experiments using the same kind of radiation, and also to make a comparison of data from experiments using the different kinds of radiations. However, it is indispensable for boron neutron capture therapy to make a radiobiological analysis. More intensive study, including repair process and oxygen effect, is necessary for establishing the fundamental basis of the clinical application of boron neutron capture therapy.

Animals↗
PubMedDate not supplied

Estimation of absorbed dose in the covering skin of human melanoma treated by neutron capture therapy.

A patient with malignant melanoma was treated by thermal neutron capture therapy using 10B-paraboronophenylalanine. The compound was injected subcutaneously into ten locations in the tumor-surrounding skin, and the patient was then irradiated with thermal neutrons from the Musashi Reactor at reactor power of 100 KW and neutron flux of 1.2 X 10(9) n/cm2/s. Total absorbed dose to the skin was 11.7-12.5 Gy in the radiation field. The dose equivalents of these doses were estimated as 21.5 and 24.4 Sv, respectively. Early skin reaction after irradiation was checked from day 1 to day 60. The maximum and mean skin scores were 2.0 and 1.5, respectively, and the therapy was safely completed as far as skin reaction was concerned. Some factors influencing the absorbed dose and dose equivalent to the skin are discussed.

Aged↗
PubMedDate not supplied

Negative effect of transforming growth factor-beta-1 on intestinal anastomotic tissue regeneration.

To examine the involvement of transforming growth factor-beta(1 )(TGF-beta(1)) in intestinal anastomotic repair, we administered a TGF-beta(1)-neutralizing antibody to rats after operation, and then examined its influence on the healing process and interaction with other peptide growth factors. Thirty male Sprague-Dawley rats were subjected to primary anastomosis after transection of the small intestine (n = 30) and treated by intraperitoneal administration of IgG (n = 15) or the TGF-beta(1) neutralizing antibody (n = 15). Treatment with the antibody against TGF-beta(1) resulted in more definite mucosal growth and increased vascularity on day 5 after surgery. Augmented mRNA expression of epidermal growth factor and vascular endothelial growth factor, and an increased number of cells that expressed these peptides in granulation tissue were demonstrated by RT-PCR and immunohistochemical staining. Taken together it was indicated that TGF-beta(1) has negative effects on regeneration of the bowel wall mucosa and angiogenesis in the course of intestinal anastomotic wound healing.

Anastomosis, Surgical↗
PubMedDate not supplied

Microlaryngosurgery for benign posterior glottal lesions using a posterior glottis direct laryngoscope.

When endolaryngeal microscopic laryngosurgery (microlaryngosurgery) with a direct laryngoscope is used to remove lesions of the posterior glottal area under endotracheal general anesthesia, the endotracheal tube interferes with the surgical field. To overcome this problem, we developed a special direct laryngoscope with a concave groove on the upper portion of its distal tip. The concave groove is used to move the endotracheal tube anteriorly, making it possible to obtain a good surgical field in the posterior glottal area. This laryngoscope facilitates the removal of posterior glottal lesions. The utility of this microlaryngosurgical technique for the removal of benign posterior glottal lesions is described.

Adult↗
PubMedDate not supplied

Involvement of beta-adrenergic receptor kinase-1 in homologous desensitization of histamine H2 receptors in human gastric carcinoma cell line MKN-45.

The poorly differentiated human gastric carcinoma cell line MKN-45 possesses histamine H2 receptors which are homologously desensitized by histamine. In order to clone the cDNA of a receptor kinase specific for H2 receptors, we performed RT-PCR at a low annealing temperature using oligo-DNA primers bearing the conserved sequences of the kinase domain of the G protein-coupled receptor kinase (GRK) family. However, we were able to isolate only cDNAs for beta-adrenergic receptor kinase 1 (beta ARK1) and GRK6. Interestingly, treatment of MKN-45 cells with beta ARK1 antisense phosphorothioate oligo-DNA (PON) resulted in significant loss of desensitization of H2 receptors by histamine, whereas GRK6 antisense PON had no effect. Thus, beta ARK1 appears to be involved in the homologous desensitization of H2 receptors in MKN-45 cells.

Blotting, Northern↗
PubMedDate not supplied

Comparison of in vitro antimicrobial activity of AM-1155 with those of tosufloxacin and fleroxacin against clinical isolates of Neisseria gonorrhoeae harboring quinolone resistance alterations in GyrA and ParC.

The in vitro antimicrobial activities of AM-1155, a new fluoroquinolone, tosufloxacin and fleroxacin were tested against 55 clinical isolates of Neisseria gonorrhoeae using the agar dilution method. In our previous study, all the strains had been examined for mutations in the region corresponding to the quinolone-resistance determining region of the Escherichia coli gyrA gene and the analogous region of the parC gene, and tested for susceptibility to ciprofloxacin. In this study, the 55 isolates of N. gonorrhoeae were assigned to one of three categories based on the presence or absence of alterations in GyrA and ParC. In each category, the antimicrobial activity of AM-1155 against the isolates was compared with those of tosufloxacin and fleroxacin. The MICs of AM-1155 for 11 highly fluoroquinolone-resistant isolates with alterations in both GyrA and ParC ranged from 0.06 to 1.0 microgram/ml. The MICs inhibiting 50% (MIC50) and 90% (MIC90) of these isolates were 0.125 and 1.0 microgram/ml, respectively. The MICs of AM-1155 for 20 moderately fluoroquinolone-resistant isolates with alterations only in GyrA ranged from 0.03 to 0.25 microgram/ml (MIC50, 0.06 microgram/ml; MIC90m, 0.125 microgram/ml). The MICs of AM-1155 for 24 of the quinolone-susceptible isolates without alterations in either GyrA or ParC ranged from 0.004 to 0.03 microgram/ml (MIC50, 0.008 microgram/ml. MIC90, 0.015 microgram/ml). There were significant differences between the MIC distribution of AM-1155 and each corresponding MIC distribution of tosufloxacin and fleroxacin in these three categories to which the 55 isolates were assigned (p < 0.05). Based on the MIC90S of the tested fluoroquinolones, AM-1155 was two- and eightfold more active against the highly fluoroquinolone-resistant isolates than tosufloxacin and fleroxacin, respectively. Against the moderately fluoroquinolone-resistant isolates, AM-1155 was four- and sixteenfold more active than tosufloxacin and fleroxacin, respectively. Against the quinolone-susceptible strains, AM-1155 was also two- to fourfold more active than the other fluoroquinolones. Overall, AM-1155 exhibited more potent in vitro activity against both quinolone-resistant and quinolone-susceptible isolates of N. gonorrhoeae than tosufloxacin and fleroxacin. In ciprofloxacin treatment failures of gonorrhea at single doses of 500 mg. MICs for the causative organisms have ranged from 1.0 to 16.0 micrograms/ml. The MICs of AM-1155 for the isolates harboring quinolone resistance-associated genetic alterations, including strains exhibiting ciprofloxacin MICs of 2.0 and 8.0 micrograms/ml, still ranged from 0.03 to 1.0 microgram/mL A single-dose study in humans has demonstrated higher peak serum concentrations and longer half-lives of AM-1155, resulting in the AUC0-00 values of AM-1155, which are threefold greater than those of ciprofloxacin at the single doses of 400 and 600 mg. Because of its potent in vitro antimicrobial activity and advantageous pharmacokinetic behavior, AM-1155 may be a clinically useful agent for treating gonorrhea including that caused by quinolone-resistant strains.

Anti-Infective Agents↗
PubMedDate not supplied

Papillary adenocarcinoma possibly arising from an intraductal papilloma of the parotid gland.

We report a case of a 70-year-old female with a papillary adenocarcinoma which we believe to have originated from an intraductal papilloma of the parotid gland. A few cases of intraductal papilloma of a minor salivary gland have been reported; however, to our knowledge, intraductal papilloma and, hence, adenocarcinoma originating from an intraductal papilloma of the parotid gland, have never been described.

Adenocarcinoma, Papillary↗
PubMedDate not supplied

Isolated non-Hodgkin's malignant lymphoma of the larynx presenting as a large pedunculated tumor.

This paper presents a case of non-Hodgkin's lymphoma (NHL) of the larynx. The patient was an 86-year-old man who complained of foreign-body sensation and dysphagia. Laryngoendoscopic examination revealed a large pedunculated mass arising from the left aryepiglottic fold. A diffuse, large, B-cell-type NHL was diagnosed histopathologically. The patient was treated with combination chemotherapy, resulting in complete clinical remission. The clinicopathological features of this case have been described and compared with previously reported cases.

Aged↗
PubMedDate not supplied

Dilator naris muscle.

The human nose is an important organ of respiration which by virtue of its valvular influence becomes a significant effector of respiratory resistance over a wide range of ventilatory requirements. In man its effectiveness in this regard is related to its flow limiting segment (FLS) located at the limen nasi. Its passive valvular effect is additionally modified by active respiratory contractions of the dilator naris muscle (DNM) controlled through the VII cranial nerve by the brain stem respiratory center. Its behavior, quantitatively determined in human beings and experimental animals, is summarized. 1) In man, phasic DNM activity operates during eupneic nasal breathing and varies directly with ventilatory resistance. 2) The elimination of all measurable ventilatory resistance results in complete cessation of DNM activity. 3) Over time, reduced resistance produces difficulty in reestablishing dilator function once it is physiologically lost. 4) DNM respiratory activity is modified by pulmonary mechano- and pressure-receptors via afferent vagal pathways. The response of nasal dilators in valvular control, therefore, appears dependent on the physiologic integrity of the vagus nerves. It is our belief that nasal valvular control has not previously been appreciated in this context.

Animals↗
PubMedDate not supplied

Functional organization of the human primary motor area: an update on current concepts.

Studies on the functional mapping of the human primary motor cortex (MI) are reviewed. In human subjects, the MI has been generally recognized as the cortical executive locus for all voluntary movements. However, some investigators have reported that activity in the MI is related to ipsilateral distal limb movements, and that the MI hand area contains subregions which are related to preparatory activity and subregions which change their activity with the learning of new motor skills. These recent findings challenge the traditional concepts of the functional role of the MI.

Brain Mapping↗
PubMedDate not supplied

Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) associated with Ramsay Hunt syndrome: report of a case and review of the literature.

A case of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) associated with Ramsay Hunt syndrome is reported. A 59-year-old man was admitted to our department for treatment of left facial pain that had persisted for three days. A left renal tumor had been diagnosed and a radical nephrectomy had been performed two months earlier. On admission, vesicular lesions were found in the left external auditory canal and ear lobe. Additionally found were left facial nerve palsy and hearing loss. Acyclovir 5 mg/kg, three times per day, was started. Five days after admission, the patient became confused and disorientated. Further investigation revealed hyponatremia 118 mEq/l, low serum osmolality, high urine osmolality, normal renal function, normal adrenal and thyroid hormones, and high plasma vasopressin 30 pg/ml. Although cerebrospinal fluid (CSF) examination revealed a mild elevation in protein and cells, no malignant cells were present and bacterial examinations were negative. Antibodies to varicella-zoster virus (VZV) in both IgG and IgM were present in high titers not only in the serum but also in the CSF. Intravenous hypertonic saline and water restriction were started, and the patient's sensorium was improved in accordance with the increase in serum sodium concentration. These results indicate that the hyponatremia in this case was due to SIADH and that SIADH was caused by an increased release of vasopressin probably because of the infection of VZV in the central nervous system.

Antibodies, Viral↗