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Biomedical subjects

H Tsuchiya

Publications and source records attributed to H Tsuchiya.

At least 127 records · Page 7Linked to original sources
PubMed1995

Electrophysiologic correlates of age effects on visuospatial attention shift.

The effects of age on the neural processes underlying shifts in visuospatial attention were studied by non-invasive recording of brain electrical activity. Event-related evoked potentials (ERPs) were recorded in young (age 28-36 years old) and elderly (59-74 years old) subjects during a target detection task. Targets were preceded by central or peripheral informative cues, which are hypothesized to provoke voluntary and reflexive shifts of spatial attention, respectively. There were no age-related differences in the effects of cue validity on reaction times. Elderly subjects had longer reaction times to both the valid and invalid targets. The ERP recordings demonstrated that attention shift-related negativities (ARNs) were generated over the hemisphere contralateral to the central cue direction with the same amplitude in young and elderly subjects. However, the onset latency was delayed for the elderly at anterior scalp sites. Peripheral cues enhanced the N1 component (140-200 ms post-cue) over the contralateral hemisphere comparably in the two age groups. The ARNs following N1 enhancement demonstrated delayed onset and restricted scalp distributions in the elderly group compared with the young group. These results suggest that resistance of cue validity effects to aging is consistent with existence of the N1 enhancement and ARNs, even in elderly subjects. Different age effects on ERPs generated by central and peripheral cues support the notion that voluntary and reflexive mechanisms of attention shift involve distinct neural systems with different vulnerability to aging.

Adult↗
PubMed1995

Fatal cytomegalovirus myocarditis in a seronegative ALL patient.

Fatal cytomegalovirus (CMV) myocarditis occurred in a 2 year old boy with acute lymphoblastic leukemia (ALL) in remission. The patient showed mild hepatic dysfunction and a rapid progress of pancytopenia after complete remission had been achieved. At the fifth week of complete remission, he presented signs of heart failure such as tachycardia, S4 gallop on auscultation and decreased ejection fraction on echocardiography. However, no significant electrocardiographic changes were recognized. In addition to the cardiac dysfunction, the patient presented a marked tachypnea and dyspnea associated with hypoxemia. These were dramatically improved by methylprednisolone pulse therapy (30 mg/kg per day, for 3 days) and CMV high titer immunoglobulin (400 mg/kg per day, for 3 days). On the sixth day after signs of respiratory failure were improved, the patient suddenly presented a paroxysmal atrial tachycardia followed by a fatal ventricular fibrillation. Although we could detect neither a specific IgM antibody, a significant increase of IgG antibody, nor CMV genome by DNA hybridization techniques during the course of the illness, microscopic examination of necropsy specimens of the heart showed a marked disruption and disintegration of muscle bands associated with cytomegalic inclusion bodies. Polymerase chain reaction (PCR) yielded a 305 bp amplification product in the heart and lung tissues, supporting the view that myocarditis was caused by CMV.

Antibodies, Viral↗
PubMed1995

Antibacterial activity of flavanostilbenes against methicillin-resistant Staphylococcus aureus.

Three phytochemical compounds (alopecurone A-C), flavanostilbenes which are produced by condensation between a hydroxyflavanone and a hydroxystilbene, were isolated as major components from the root of Sophora alopecuroides. They uniformly inhibited the growth of 21 strains of methicillin-resistant Staphylococcus aureus with minimum inhibitory concentrations of 3.13-6.25 micrograms ml-1.

Anti-Bacterial Agents↗
PubMed1995

c-Jun, c-Fos and their family members activate the transcription mediated by three 21-bp repetitive sequences in the HTLV-I long terminal repeat.

Transcription of human T-cell leukemia virus type I is regulated by a viral transactivatior Tax, through the 21-bp sequence in the long terminal repeat (LTR). We found that cellular transcription factor AP-1 (c-Jun/c-Fos heterocomplex) bound to the 21-bp sequence. The binding affinity of the complex increased in proportion to the number of the 21-bp sequence, and the transcriptional activation by AP-1 became evident only when the reporters had more than three 21-bp sequences. Thus, AP-1 may play a role in the viral transcription from the LTR with three 21-bp sequences in the absence of Tax, such as in the early stage of the virus infection.

Amino Acid Sequence↗
PubMed1995

A late-appearing Philadelphia chromosome in acute lymphoblastic leukemia confirmed by expression of BCR-ABL mRNA.

We report two cases of acute lymphoblastic leukemia (ALL) with a late-appearing Philadelphia chromosome (Ph1), confirmed by the expression of BCR-ABL mRNA, using the reverse transcriptase/polymerase chain reaction (RT/PCR) technique. The first patient was a 10-year-old boy with precursor B cell type ALL-L1 (FAB classification). At diagnosis, no metaphase cells were found by chromosome analysis and BCR-ABL mRNA was not observed. At the beginning of relapse, which occurred after 7 months of complete remission, a normal karyotype was observed. At the terminal stage, leukemic cells with Ph1 and BCR-ABL mRNA for the P190 variety were observed. The second patient was a 12-year-old boy with immature T cell type ALL-L1. The metaphase cells showed a 9p- chromosome at diagnosis and Ph1 appeared in addition to 9p- at relapse. Hybrid mRNA for the P210 variety was detected only when Ph1 had developed. The blast cells with Ph1 were derived from the original leukemic clone through clonal evolution, since the same clonal rearrangements of IGH or TCRB were detected in leukemic cells obtained both at diagnosis and relapse in both patients. Thus, in both cases, Ph1 was detected only in the course of ALL along with expression of BCR-ABL mRNA. This observation also confirmed that, as in de novo Ph1-positive ALL, both the P190 and P210 varieties of BCR-ABL mRNA are observed in ALL with late-appearing Ph1.

Base Sequence↗
PubMed1995

Shepherd's crook deformity with an intracapsular femoral neck fracture in fibrous dysplasia.

A shepherd's crook deformity with an intracapsular femoral neck fracture in the fibrous dysplasia of a 19-year-old woman is reported. The deformity and fracture were treated by bone grafting using a single fibula through the femoral neck to its head, and corrective valgus osteotomy. Blood flow measurement using electrochemically generated hydrogen clearance was useful in evaluating avascular necrosis of the femoral head affected by tumorous tissue. Osteosynthesis combined with a fibular graft, and corrective valgus osteotomy after proper evaluation of the blood flow in the femoral head, is a reliable procedure for the treatment of shepherd's crook deformity associated with an intracapsular femoral neck fracture.

Adult↗
PubMed1995

The antibody to plasminogen activator inhibitor-1 suppresses pulmonary metastases of human fibrosarcoma in athymic mice.

We studied the effects of the plasminogen activator inhibitor-1 (PAI-1), the urokinase-type plasminogen activator (uPA) and their antibodies on hematogeneous pulmonary metastases formation of human fibrosarcoma in athymic mice. We used a human fibrosarcoma cell line (HT-1 080) with low metastatic potential, and a subpopulation of HT-1 080 (HT-1 080-P4) with high metastatic potential which was selected by repeating injections into the tail veins of athymic mice. We examined the effects of these drugs on pulmonary metastases formation according to Wexler's method and the number of tumor cell emboli in the lung subsequent to an injection of radio-labeled tumor cells. Pulmonary metastases formation from HT-1 080 was not affected by any of the tested drugs. Pulmonary metastases from HT-1 080-P4 increased with uPA and anti-uPA antibody injections. PAI-1 slightly increased pulmonary metastases from HT-1 080-P4, and the anti-PAI-1 antibody decreased it (60.9 + 27.7% of control, p < 0.05). While none of the drugs altered the number of HT-1 080 cells in the lung at 24, 48 and 72 hours after the injection, PAI-1 increased the number of HT-1 080-P4 cells in the lung, whereas uPA and PAI-1 decreased it. The result that these drugs did not affect the metastatic potential of HT-1 080 but only that of HT-1 080-P4, indicates that fibrinolysis plays an important role in hematogenous pulmonary metastases formation of tumor cells with high metastatic potential. The effects of uPA suggest that uPA facilitates pulmonary metastasis formation probably due to an increase in the invasive ability of tumor cells. The effects of PAI-1 and its antibody of HT-1 080-P4 cells suggest that PAI-1 may facilitate tumor cell lodgement in vessels and the anti-PAI-1 antibody could be able to suppress pulmonary metastases of tumor cells with high metastatic potential by inhibition of tumor cell lodgement in vessels.

Animals↗
PubMed1994

The predisposing gene of the Eker rat inherited cancer syndrome is tightly linked to the tuberous sclerosis (TSC2) gene.

The Eker rat is a promising animal model of cancer predisposition syndromes. In this study, using 129 backcross animals, we have established a new conserved linkage group on rat 10q and human 16p13.3 whereby the Eker mutation was found to be tightly linked to the tuberous sclerosis (TSC2) gene. This will be the first step toward the positional cloning and identification of the predisposing Eker mutation.

Animals↗
PubMed1994

Inhibition of the growth of cariogenic bacteria in vitro by plant flavanones.

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified from Sophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 micrograms/ml.

Actinomyces↗
PubMed1994

Quantitation of urinary 1,2,3,4-tetrahydro-beta-carboline and 1-methyl-1,2,3,4-tetrahydro-beta-carboline by high-performance liquid chromatography.

A high-performance liquid chromatographic method was developed to quantify 1,2,3,4-tetrahydro-beta-carboline (TBC) and 1-methyl-1,2,3,4-tetrahydro-beta-carboline (MTBC) in human urine. Urine samples with added internal standard were subjected to a reaction with fluorescamine and solvent extractions to remove the precursor tryptamine, which readily condenses with aldehydes in samples and reagents. Such a pretreatment completely suppressed the artifactual formation of TBC and MTBC during analytical procedures. The purified original tetrahydro-beta-carbolines and the internal standard were separated by reversed-phase ion-pair chromatography with fluorescent detection. Their simultaneous separation was automatically completed in a short time (< 12 min). Both TBC and MTBC were quantified at ng/mL concentrations. The quantitative results revealed a wide variation in urinary levels of TBC and MTBC, possibly indicating that their considerable amounts excreted in the urine originate from dietary sources.

Adolescent↗
PubMed1994

Use of latissimus dorsi flap for reconstruction with prostheses after tumor resection.

Five latissimus dorsi musculocutaneous flaps (LD flap) were used for reconstruction with prostheses after resection of tumors between 1984 and 1991 in our hospital. Bony structures were reconstructed with prostheses and in three cases autoclaved autobone grafts were also needed. The prostheses and adjacent grafts were then wrapped by the LD flaps. Tumor sites included one humerus, two thighs, and two knees. All but one case healed primarily. The sole case of infection was successfully treated with debridement and irrigation. Due to the LD flaps' plentiful blood supply, we believe infection of the prosthetics can be avoided and good clinical results can be achieved using the flap with autoclaved autograft prosthetic composite reconstruction.

Adolescent↗
PubMed1994

Calcium concentration and fertilization by subzonal insemination of a single spermatozoon in mouse oocytes.

The effect of calcium concentration in culture medium on the fertilization of subzonally microinseminated mouse oocytes was examined. Oocytes were injected with a single spermatozoon so that the sperm head was forced to adhere onto the ooplasmic membrane with a micromanipulation technique. For the inseminations, epididymal spermatozoa preincubated in culture medium and those treated with ionophore A23187 were used. Inseminated oocytes were cultured using media with three different calcium concentrations of 1.71, 3.42, and 5.13 mM; 40.0%, 71.6%, and 47.9% of oocytes microinjected with preincubated sperm were fertilized after incubation with those media, respectively. When the oocytes inseminated with ionophore-treated sperm were incubated in media containing 1.71 and 3.42 mM calcium, their fertilization rates were 58.2% and 87.5%. Thus fertility of subzonally microinseminated oocytes was obviously enhanced when cultured in medium with 3.42 mM of calcium, irrespective of being inseminated with preincubated sperm (P < 0.01) or with ionophore-treated sperm (P < 0.005). Some of the microinseminations with preincubated sperm were performed without sperm adhered to the oolemma. In these cases, the incidence of fertilization was not improved by incubating the inseminated oocytes in medium containing 3.42 mM calcium (32.6%) as compared to those incubated in medium with 1.71 mM calcium (28.3%). These results suggest that the concentration of extracelluar calcium exerts an important effect on the progress of fertilization events subsequent to sperm adherence onto the ooplasmic membrane. Almost 80% of the zygotes fertilized via incubation in medium with 3.42 mM of calcium developed into blastocysts after culturing in vitro.

Animals↗
PubMed1994

Urinary excretion of the enantiomers of 1-methyl-1,2,3,4-tetrahydro-beta-carboline in unequal abundance implies enzymatic metabolism in man.

1-Methyl-1,2,3,4-tetrahydro-beta-carboline, a condensation product of tryptamine and acetaldehyde, is one of the neuropharmacologically active alkaloids in mammals. Its enantiomers excreted in human urine were independently analyzed by gas chromatography-negative ion chemical ionization mass spectrometry. Mass fragmentograms of the racemic 1-methyl-1,2,3,4-tetrahydro-beta-carboline offered two peaks with (S)-(-)- and (R)-(+)-configurations which were eluted in this retention order. When the racemic tetradeuterated 1-methyl-1,2,3,4-tetrahydro-beta-carboline was orally administered to a human subject, the urinary tetradeuterated enantiomers were found to be of unequal abundance. The deuterated (R)-(+)-1-methyl-1,2,3,4-tetrahydro-beta-carboline was predominantly excreted in human urine about 3-times over the deuterated (S)-(-)-one. The stereoselective difference in the urinary excretion of 1-methyl-1,2,3,4-tetrahydro-beta-carboline administered exogenously implies that it is enzymatically metabolized, but not that its biosynthesis is associated with an enzymatic reaction.

Administration, Oral↗
PubMed1994

Total en bloc spondylectomy for solitary spinal metastases.

We have developed a technique for total en bloc spondylectomy through a posterior approach and now report our experience of 20 patients with a solitary or localised metastasis in the thoracic or lumbar vertebrae. There are two steps: an en bloc laminectomy, followed by en bloc resection of the vertebral body with an oncological wide margin and the insertion of a vertebral prosthesis. Pain was relieved in the 17 patients who could be assessed; 11 of the 15 patients with a neurological deficit were much improved, impending paralysis being prevented in 5 patients. There have been no local recurrences. Nine patients are at present alive with a mean follow up of 17.4 months.

Adult↗
PubMed1994

Expression of matrix metalloproteinase 9 (92-kDa gelatinase/type IV collagenase) induced by tumour necrosis factor alpha correlates with metastatic ability in a human osteosarcoma cell line.

We have examined the correlation between matrix metalloproteinase (MMP) expression and metastatic properties of a low metastatic osteosarcoma cell line, osteosarcoma takase (OST), under stimulation by tumour necrosis factor alpha (TNF alpha). In vivo, OST cells exhibited significantly increased colonization in the lungs of nude mice in a dose-dependent manner when they were treated by TNF alpha prior to injection. In vitro, TNF alpha enhanced tumour cell invasion through the reconstituted basement membrane in a transwell chamber up to 2.5-fold. Gelatin zymography and sandwich enzyme immunoassays demonstrated marked production of MMP-9 [92-kDa gelatinase/type IV collagenase (gelatinase B)] but not MMP-2 [72-kDa gelatinase/type IV collagenase (gelatinase A)], MMP-3 (stromelysin-1) or MMP-7 (matrilysin). Motility of the tumour cells and adhesion to cultured endothelial cells were slightly increased by the TNF alpha treatment up to 1.6-fold and 1.4-fold, respectively, while the growth rate was decreased. These results suggest that upregulation of MMP-9 together with enhanced motility and endothelial adhesion contribute to the increased metastatic ability of OST cells induced by TNF alpha treatment.

Collagenases↗
PubMed1994

A family of selective immunodeficiency with normal immunoglobulins: possible autosomal dominant inheritance.

We report here our findings in two Japanese siblings who experienced recurrent bacterial and viral infections since early infancy. Recent symptoms included diarrhoea, conjunctivitis, rashes, headache, sore throat, joint pain, vomiting and vertigo, all similar to those seen in toxic shock syndrome, except for shock. These symptoms improved following gammaglobulin treatment. Staphylococcus aureus with coagulase type IV was continuously isolated from nasal smears producing toxic shock syndrome toxin-1 (TSST-1). Serum antibodies did not or only poorly responded to TSST-1, diphtheria toxoid, varicella virus and rubella virus, whereas total and subclass levels of serum immunoglobulin and in vitro DNA synthesis of lymphocytes stimulated by TSST-1, Staph. aureus, varicella vaccine and mitogens were normal. In the family, ten other members in three generations (five males: five females) including the mother had similar clinical symptoms. Thus, the disease may be inherited in an autosomal dominant fashion.

Antibodies, Bacterial↗
PubMed1994

Regeneration of mesenteric lymphatic vessels in a new experimental model of orthotopic intestinal transplantation in rats.

A new experimental model of orthotopic intestinal transplantation was performed using microsurgical techniques in rats; the physiological flow of blood, lymph, and food was reconstructed. Regeneration of mesenteric lymphatic vessels, which plays an extremely important role in lipid absorption of the transplanted intestine, was studied by mesenteric lymphangiography. Regeneration of mesenteric lymphatic vessels was first confirmed on the seventh postoperative day by mesenteric lymphangiography, and favorable regenerative patterns, without obstruction, were observed on the 32nd, 58th, and 93rd postoperative days.

Animals↗