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Biomedical subjects

T Aoki

Publications and source records attributed to T Aoki.

At least 451 records · Page 25Linked to original sources
PubMed1997

Dedifferentiated liposarcoma with an inflammatory malignant fibrous histiocytoma-like component presenting a leukemoid reaction.

A rare case of dedifferentiated liposarcoma (well-differentiated liposarcoma with an inflammatory malignant fibrous histiocytoma (MFH)-like anaplastic component) occurring in a 69-year-old male is presented. The patient had noticed a dull pain in his left loin and thigh for about 1 month. Computed tomography examination revealed a low-density mass lesion, measuring about 6 cm in diameter, in the left iliopsoas muscle, and it was surgically removed. Grossly, the lesion was composed of an encapsulated, soft, whitish mass and an adjacent, well-demarcated, yellowish hard nodule, measuring about 2.5 cm in diameter. Microscopically, both lesions showed features of an inflammatory variant of MFH and a sclerosing type of well-differentiated liposarcoma, respectively. To our knowledge, only two cases of dedifferentiated liposarcoma combined with inflammatory MFH as a dedifferentiated component have been recorded in the literature. The salient feature of the present case is a systemic inflammatory reaction, as shown by prominent leukocytosis (up to 73,900/mm3) and the elevated serum value of C reactive protein (up to 26.0 mg/dL), which were transiently reduced after surgery. The inflammatory reaction was suggested to be induced by cytokines, such as granulocyte colony-stimulating factor and interleukin-6, which were probably produced by the tumor cells in the present case, because the elevated serum values of those cytokines were decreased after surgery.

Aged↗
PubMed1997

Scalp-recorded, ictal focal DC shift in a patient with tonic seizure.

PURPOSE: We recorded focal ictal DC shifts from scalp electrodes in a 9-year-old boy with intractable, clinically generalized tonic seizures. The patient had a high intensity signal abnormality of the left temporal cortex with thickening of the gyri on T2-weighted MRI. METHODS: Scalp digital EEGs were recorded using electrodes made of silver/silver chloride. The low frequency filter (LFF) was set at 0.016 Hz. Recorded seizures were subsequently analyzed with LFF settings of 1.0, 0.016 and 0.03 Hz. RESULTS: All recorded seizures initially showed diffuse, low voltage, high frequency activity (electrodecremental pattern) followed 10-20 s later by quasirhythmic activity over the left frontotemporal region. In two seizures, LFF of 0.016-0.03 Hz revealed a slow negative shift over the left frontotemporal area simultaneously with onset of the bilateral electrodecremental pattern. However, in the other seizures, this initial slow negative shift was obscured by artifacts. Subsequent electrocorticography (ECoG) delineated frequent epileptiform discharges in the left temporal as well as frontal cortex. CONCLUSIONS: Scalp-recorded ictal DC shifts may help identify focal epileptogenic brain area in patients with clinically generalized seizures although the technique is vulnerable to artifact.

Child↗
PubMed1997

[Report of questionnaire about enterohemorrhagic Escherichia coli cases caused in the area including Sakai City in 1996].

Many outbreaks of EHEC O157 were occurred in Japan in 1996. There was the biggest outbreak involving approximately 6000 victims in area of Sakai City. We conducted a questionnaire survey on the EHEC infection to the physicians who treated these patients and the microbiologists. For physicians we asked mainly clinical manifestation of patients they observed and treatment they did and their outcome (Answer A). Microbiologists were also required to answer the opinion about treatment (Answer B). Eighty-five of physicians replied about their 222 patients and 209 of microbiologists answered their opinions. In this report we summarized the data and obtained following results: 1) We observed higher frequency of HUS/TTA complication in female than male. 2) Higher HUS/TTP complication was accompanied with patients complained symptoms of fever, bloody diarrhea, and general fatigue. 3) The most patients (96%) were received antimicrobial agents, especially fosfomycin (84%), followed by new quinolon (17.8%) and Cefems (12.2%). Later starting of treatment with antimicrobial agents than 7 days from onset of symptoms increased HUS/TTP complication. 4) Anti-diarrhoeal agents seems to be one of risk factors for HUS/TTP complications.

Adolescent↗
PubMed1997

Host range phenotype induced by mutations in the internal ribosomal entry site of poliovirus RNA.

Most poliovirus strains infect only primates. The host range (HR) of poliovirus is thought to be primarily determined by a cell surface molecule that functions as poliovirus receptor (PVR), since it has been shown that transgenic mice are made poliovirus sensitive by introducing the human PVR gene into the genome. The relative levels of neurovirulence of polioviruses tested in these transgenic mice were shown to correlate well with the levels tested in monkeys (H. Horie et al., J. Virol. 68:681-688, 1994). Mutants of the virulent Mahoney strain of poliovirus have been generated by disruption of nucleotides 128 to 134, at stem-loop II within the 5' noncoding region, and four of these mutants multiplicated well in human HeLa cells but poorly in mouse TgSVA cells that had been established from the kidney of the poliovirus-sensitive transgenic mouse. Neurovirulence tests using the two animal models revealed that these mutants were strongly attenuated only in tests with the mouse model and were therefore HR mutants. The virus infection cycle in TgSVA cells was restricted by an internal ribosomal entry site (IRES)-dependent initiation process of translation. Viral protein synthesis and the associated block of cellular protein synthesis were not observed in TgSVA cells infected with three of four HR mutants and was evident at only a low level in the remaining mutant. The mutant RNAs were functional in a cell-free protein synthesis system from HeLa cells but not in those from TgSVA and mouse neuroblastoma NS20Y cells. These results suggest that host factor(s) affecting IRES-dependent translation of poliovirus differ between human and mouse cells and that the mutant IRES constructs detect species differences in such host factor(s). The IRES could potentially be a host range determinant for poliovirus infection.

Animals↗
PubMed1997

Hypogammaglobulinaemia in a patient with ring chromosome 21.

An 8 year old boy with ring chromosome 21 who was susceptible to sinorespiratory infections due to hypogammaglobulinaemia is reported. He presented with the characteristic features of monosomy 21 syndrome, such as psychomotor retardation, hypertonia, large saccular ears, prominent nasal bridge, micrognathia, thrombocytopenia, and patent ductus arteriosus. His serum IgG concentration was less than 1.5 g/l at 3 years and 6 months of age after repeated hospitalisations with pneumonia, otitis media, and convulsions. Regular replacement of intravenous gammaglobulin effectively reduced such infectious episodes. A predisposition to infection in patients with ring chromosome 21 may be explained by hypogammaglobulinaemia and merit treatment with gammaglobulin.

Agammaglobulinemia↗
PubMed1997

BAY K 8644 and ClO4- potentiate caffeine contracture without Ca2+ release channel activation.

Effects of perchlorate (ClO4-) and BAY K 8644 on caffeine contracture and Ca2+ release channel current were studied in frog skeletal muscle. Single fibers produced a small transient contracture on addition of 2.2 mM caffeine. ClO4 at 10 mM enhanced caffeine contracture 3.7-fold. This effect was inhibited by 10 microM nifedipine pretreatment. An increase in caffeine contracture was also obtained after exposure to 0.1 microM BAY K 8644 for 1 h. At 20 mM, external K+ potentiated caffeine contracture 2.2-fold. ClO4- (< 10 mM) and BAY K 8644 (0.1-1 microM) did not affect open probability (Po), unitary conductance, and open and closed time constants of the Ca2+ release channel current. BAY K 8644 at 0.1 microM did not further enhance the channel that had been activated by 2 mM caffeine. However, 20-30 mM ClO4 increased Po significantly and led the channel to a long open state by increasing the slow open time constant and decreasing the fast closed time constant. These results suggest that binding of ClO4 and BAY K 8644 to dihydropyridine receptors elicits a further increase in Ca2+ release from the sarcoplasmic reticulum.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1997

Role of CD18-ICAM-1 in the entrapment of stimulated leukocytes in alveolar capillaries of perfused rat lungs.

This study aimed to examine the behavior of stimulated leukocytes in the pulmonary microcirculation. The leukocyte-endothelium interaction was visualized under physiological shear rates in perfused rat lungs using high-speed confocal laser video microscopy. Leukocytes labeled with carboxyfluorescein were stimulated with cytokine-induced neutrophil chemoattractant (CINC/gro), which caused L-selectin shedding and inverse upregulation of CD18. Neither unstimulated nor stimulated leukocytes exhibited rolling in either pulmonary arterioles or venules, whereas both were sequestered in capillaries. Approximately 50% of stimulated leukocytes showed a transient cessation of movement in pulmonary capillaries. The CINC/ gro stimulation, which inhibited leukocyte rolling and adhesion to mesenteric venules, reduced leukocyte velocity and increased leukocytes in pulmonary capillaries. Pretreatment with monoclonal antibodies against intercellular adhesion molecule-1 (ICAM-1) or CD18 attenuated these changes. Confocal microfluorography revealed constitutive expression of ICAM-1 not only in venules but also abundantly in capillary networks. These results suggest that selectin-independent, CD18-ICAM-1-dependent capillary sequestration is one of the major mechanisms by which activated leukocytes accumulate in the lungs.

Animals↗
PubMed1997

Effect of hyperoxia on adhesion molecule expression in human endothelial cells and neutrophils.

To investigate the pathogenesis of pulmonary oxygen toxicity, we examined the effect of hyperoxia on adhesion molecule expression in cultured human pulmonary artery endothelial cells (HPAEC) and human umbilical vein endothelial cells (HUVEC). Endothelial cell monolayers were exposed to either hyperoxic (90% O(2)-5% CO(2)) or normoxic (21% O(2)-5% CO(2)) conditions for various periods. The level of intercellular adhesion molecule (ICAM)-1 expression had increased in hyperoxia-exposed HPAEC and HUVEC at 48 h (194 +/- 38 and 233 +/- 56%, respectively; P < 0.001) and at 72 h (200 +/- 43 and 223 +/- 52%, respectively; P < 0.001) compared with normoxic conditions. These hyperoxia-induced ICAM-1 expressions were dose dependently attenuated by a protein kinase C inhibitor (H-7). In contrast, the levels of P-selectin and E-selectin expression in HPAEC and HUVEC were unchanged. The levels of ICAM-1 mRNA and the numbers of adherent neutrophils were increased in HPAEC and HUVEC at 48 and 72 h of hyperoxia. On the other hand, hyperoxia caused neutrophil H(2)O(2) production without affecting the level of CD11/CD18 expression. These results suggest that increased ICAM-1 expression in endothelial cells plays an important role in neutrophil accumulation during hyperoxia.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1997

Effects of active vasoconstriction and total flow on perfusion distribution in the rabbit lung.

We analyzed the effects of hypoxic vasoconstriction and total flow on the distribution of pulmonary perfusion in 38 isolated left rabbit lungs perfused under zone 3 conditions. Lungs were suspended in an upright position, oriented to the apicobasal line. Distributions of regional perfusion rates (RPR) along the vertical and horizontal axes were determined using nonradioactive microspheres labeled with heavy metal elements, which were detectable with X-ray fluorescence spectrometry. Changing the O2 concentration of a respirator and an extracorporeal membrane oxygenator independently, respective influences of active vasoconstriction induced by alveolar hypoxia and pulmonary artery hypoxia (PA hypoxia) on the RPR distribution were examined at a flow rate of 0.4 ml x min(-1) x g wet lung tissue(-1). To analyze the effects of changes in total flow, we investigated the RPR distribution at a perfusion rate of 1.2 ml x min(-1) x g wet lung tissue(-1). The RPR distribution in the absence of hypoxia was inhomogeneous and was augmented in the lower lung fields, whereas alveolar hypoxia shifted the RPR upward and significantly diminished the RPR in the lung base. RPR distributions along the horizontal axes under alveolar hypoxia conditions demonstrated that remarkable hypoxic pulmonary vasoconstriction (HPV) takes place in medial regions at the lung base. PA hypoxia altered the RPR distribution in qualitatively the same manner as alveolar hypoxia. Increased flow rate augmented the RPR in the lung, except in the dorsobasal region. These results suggest that the occurrence of HPV and the vascular conductance are not uniform throughout the lung.

Animals↗
PubMed1997

ET-1-induced bronchoconstriction is mediated via ETB receptor in mice.

Endothelin (ET)-1 is one of the most potent agonists of airway smooth muscle and can act via two different ET receptor subtypes, i.e., ETA and ETB. To determine the effects of ET-1 on in vivo pulmonary function and which ET receptors are involved in murine lungs, we investigated 1) the effects of ET and sarafotoxin S6c (S6c), a selective ETB agonist, on pulmonary function and 2) the effects of BQ-123 and BQ-788, specific ETA- and ETB-receptor antagonists, on ET-1-induced bronchoconstriction. ICR mice were anesthetized and mechanically ventilated (frequency = 2.5 Hz, tidal volume = 8 ml/kg, positive end-expiratory pressure = 3 cmH2O). Intravenous ET-1, ET-2, and ET-3 increased lung resistance similarly and equipotently, whereas S6c elicited a greater degree of bronchoconstriction. Mice were then pretreated with saline (Sal), BQ-123 (0.2, 1, and 5 mg/kg), or BQ-788 (0.2, 1, and 5 mg/kg) before administration of ET-1 (10(-7) mol/kg iv). No dose of BQ-123 blocked ET-1-induced constriction, whereas pretreatment with each dose of BQ-788 significantly inhibited ET-1-induced responses. There were significant differences in morphometrically assessed airway constriction between Sal and BQ-788 and between BQ-123 and BQ-788, whereas no significant difference was observed between Sal and BQ-123. There were no significant morphometric differences in the airway wall area among the three groups. These observations suggest that the ETB- but not ETA-receptor subtype may mediate the changes in murine pulmonary function in response to ET-1. In addition, the ETB-receptor antagonist reduces ET-1-induced airway narrowing by affecting airway smooth muscle contraction in mice.

Animals↗
PubMed1997

Effect of phenylboronic acid groups in copolymers on endothelial cell differentiation into capillary structures.

Copolymers (IABb) composed of N-isopropylacrylamide (I), N-(3-dimethylaminopropyl)-acrylamide (A), 3-acrylamidophenylboronic acid (B), and a hydrophobic comonomer, n-butyl methacrylate (b), were synthesized as cell culture substrata since we previously learned that bovine aortic endothelial cells (BAECs) cultured on the phenylboronic acid-containing copolymer (IAB) differentiated into capillary structures after 26 days culture. The synthesized IABb copo ymers contained higher boron and amine moieties than the IAB copolymer. The results of the dynamic contact angle measurement revealed that IABb copolymer-coated surfaces showed a relatively hydrophobic nature, changing to hydrophilic in response to the aqueous environment. BAECs cultured on the copolymer substrata developed into capillary networks after 7 days. This is probably due to the enrichment of boron and amine segments in the vicinity of the hydrophilic copolymer surface, enhancing more pronounced interaction of boronates with cell membrane glycocalyx. The introduction of n-butyl methacrylate into the polymers might enhance the diffusion of the hydrophobic segments to the bulk polymers and the concentration of relatively hydrophilic segments at the outermost polymer surfaces by contact with water. A copolymer (IAP) without boronic acid groups was also prepared using N-phenylacrylamide (P) as a comonomer instead of 3-acrylamidophenylboronic acid in the IAB copolymer to investigate the effect of boronic acid moieties on the capillary formation of the cultured cells. Although the endothelial cells seeded on the copolymer without boronic acid groups adhered during the early culture period, these cells showed neither proliferation nor differentiation and detached from the surface after 13 days. These results strongly support the opinion that the phenylboronic acid groups in the copolymers are responsible for the specific induction of tissue formation of BAECs through the interaction with glycoconjugates on the cell membranes.

Acrylamides↗
PubMed1997

Biochemical and immunochemical properties of modified human neuron-specific enolase.

125I-Labeled recombinant human neuron-specific enolase (R-NSE) was inadequate for RIA as a labeled antigen. The binding activity of labeled R-NSE to the antibody was markedly decreased. To supplement this defect and facilitate purification, we constructed two R-NSE derivatives, Y-NSE (one tyrosine residue was added at the N-terminal of R-NSE) and Y-NSE.H6 (six histidine residues were further added at the C-terminal of Y-NSE). The biochemical and immunochemical characteristics of these R-NSE derivatives were essentially the same to those of R-NSE. These derivatives were useful not only as standards for enzyme immunoassay (EIA), but also as labeled antigens for RIA. These results clearly indicate that the reactivity of these modified NSEs to anti-NSE antibody is almost equivalent to that of human brain gammagamma-enolase (B-NSE), and that even if the modified NSEs are labeled, they retain their binding affinities to antibodies in contrast to R-NSE.

Base Sequence↗
PubMed1997

Evaluation of scratch movements by a new scratch-monitor to analyze nocturnal itching in atopic dermatitis.

Itching is very important in atopic dermatitis, but the details of itching or scratch movements, especially during sleep at night, have not yet been fully comprehended. We designed a new, simple device, the Scratch-Monitor (SM), to evaluate scratch movements at night and assessed the usefulness of this device by a comparison involving 26 patients and 17 healthy controls. The SM, a box weighing only 25 g with a pressure sensor on the bottom, is attached to the back of each hand under a cotton glove and records the number as scratch movements per minute in the case of more than three successive changes of pressure. The SM indicated that patients with atopic dermatitis scratched more frequently and suffered more severe sleep disturbance than healthy controls. Although the SM had several problems related to specificity and sensitivity, we conclude that the SM is a useful tool for evaluating nocturnal itching.

Adolescent↗
PubMed1997

Correlations for social support with depression in the chronic postsroke period.

This study examined correlations of social support with rated mood states, including depression, for 47 patients with cerebrovascular disease during the chronic poststroke period. After the Structured Clinical Interview for DSM-III-R, four psychological measures, the Zung Self-depression Scale, the Hamilton Depression Scale, Profile of Mood States, and Social Support Scale, were administered. The patients with cerebrovascular disease exhibited significantly more psychiatric disorders, including depression, and had poorer social support than healthy controls. The severity of depression was significantly related to poor social support and particularly to the presence of social support rather than just the perception of poor social support. Depressed patients may also rate their support as poor because they are depressed. For some patients with cerebrovascular disease during the chronic poststroke period, depression may be related to low social support.

Aged↗
PubMed1997

[Intracellular distribution of bovine serum albumin-conjugated doxorubicin and multidrug resistance].

The intracellular distribution of bovine serum albumin (BSA)-conjugated [14C] doxorubicin (DXR) was investigated in a rat hepatoma cell line (AH66P) and its anthracycline resistant subline (AH66DR). After the conjugate had been taken up into the cells by endocytosis and degraded in the lysomes, active adducts with a molecular mass of approximately 2 kDa were distributed to target organellae such as nuclei and mitochondria. Drug accumulation in the nuclear fraction was lower in AH66DR cells than in AH66P cells, but the level of drug radioactivity in the DNA fraction, which was extracted from the same nuclear fraction, was higher in the AH66DR cells than in AH66P cells. It is presumed from these results that the intercalated level of the drug into DNA was sufficient to exhibit cytotoxicity against AH66DR cells as well as AH66P cells. A part of the active adducts was effluxed from AH66DR cells by P glycoprotein (Pgp) in the same manner as DXR because the efflux of the adducts was suppressed by verapamil, an inhibitor of Pgp. The IC50 values of BSA DXR conjugate was decreased from 120 nM to 2 nM for AH66DR cells and from 3 nM to 0.6 nM for AH66P cells by the co-treatment with 5/M verapamil, respectively.

Animals↗
PubMed1997

[Surgical treatment of T4 lung cancer: combined resection of lung and heart or great vessels].

From 1980 to 1995, sixteen patients with T4 lung cancer underwent resection of left atrium (LA) or great vessels combined with pulmonary resection. For eight patients with lung cancer invading LA, LA was resected under simple clamp of LA in seven cases, and under extracorporeal circulation in one case. For three patients with lung cancer invading aorta, resection and reconstruction of aorta was performed under femoro-femoral bypass in one case, and under temporary bypass using a heparin-coated tube in two cases. For five patients with lung cancer invading superior vena cava (SVC), SVC was resected under partial clamp or simple clamp of SVC in each case. In remaining three patients, SVC was resected under internal bypass in one case, and under temporary bypass using a heparin-coated tube in two cases. Three were two operative deaths, one (SVC) died of acute heart failure, and the other (LA) died of acute respiratory distress syndrome. Four patients are alive without recurrence and three of them (one LA and two SVC) have been surviving more than five years after operation.

Aged↗