Biomedical subjects

E Ito

Publications and source records attributed to E Ito.

At least 109 records · Page 6Linked to original sources

PubMed1999

Physiological characterization of lip and tentacle nerves in Lymnaea stagnalis.

The lip and tentacle nerves of the pond snail, Lymnaea stagnalis, were characterized using electrophysiological techniques. When the activity of those nerves was induced in lip-tentacle preparations, aversive taste signals were transmitted through all the lip and tentacle nerves, but appetitive signals could be recorded only through the superior lip nerve. In the CNS immersed in high Mg2+ -high Ca2+ saline, electrical stimuli applied to any of the nerves failed to induce action potentials in one of the regulatory neurons (cerebral giant cell: CGC) involved in feeding responses, implying that the signals are polysynaptically transmitted to the CGC. Intracellular recordings revealed that the CGCs in semi-intact half-body preparations received both appetitive and aversive taste signals not only through the superior lip nerve but also through the median lip nerve. In addition, an osphradium was ruled out as a candidate for appetitive reception. The present results, together with our preceding data arrived at by the histochemical analyses, indicate that the appetitive taste transduction responsible for generating feeding responses is performed through the superior lip nerve with some contribution of the median lip nerve. The data showing that the CGC can receive various taste signals suggests that it may play a crucial role in feeding behavior as demonstrated in the study of conditioned taste-aversion.

Animals↗

PubMed1999

Primary malignant melanoma of the uterine cervix: a case report.

We report on a case of a malignant melanoma of the uterine cervix. Histological and immunohistological examinations of a postsurgical specimen revealed malignant melanoma. The junctional activities did not occur due to extensive superficial ulceration. Radical surgery was performed. The patient is doing well and free of symptoms at this time, 2 1/2 year later.

Aged↗

PubMed1999

Characterization of subclonal cell lines showing high motility derived from an undifferentiated human endometrial cancer cell line.

To examine the relationship between the morphology and the motility of cancer cells, we studied the difference between human endometrial undifferentiated cancer cell lines with different motilities, using light and electron microscopy, immunocytochemistry and RT-PCR. In a transplanted tumor of a cell line with high motility, many connective tissues and microvessels were observed and there were few intercellular spaces, which were ultrastructurally full of extracellular matrix. In the high-motility cell line only cytokeratin 19 was observed, and the level of cytokeratin 19 mRNA was elevated. Thus, motility is suggested to be related to the induction of connective tissues and cytoskeleton.

Animals↗

PubMed1999

Exercise-induced rise in arterial potassium in patients with chronic heart failure.

OBJECTIVES: In patients with chronic heart failure (CHF), exercise is frequently associated with skeletal muscle fatigue and breathlessness due to heightened ventilatory response. The exercise-induced rise in potassium, which is released from the exercising skeletal muscle, has been implicated in ventilatory control during exercise. The aim of the present study was to determine whether the exercise-induced rise in arterial potassium is altered in patients with CHF and to examine the relationship between increased exercise ventilation and exercise-induced hyperkalemia in patients with CHF. METHODS AND RESULTS: We evaluated 88 patients with CHF (25 patients were in class I, 35 in class II, and 28 in class III according to the New York Heart Association functional classification) and 14 normal subjects. Subjects performed symptom-limited ergometer exercise while expired gas, arterial blood gas, and arterial potassium were analyzed. The increases in ventilation (deltaV(E)), effective alveolar ventilation (deltaVA), and carbon dioxide output (deltaV(CO2)) from rest to peak exercise decreased as the severity of CHF advanced. The ratio of deltaV(E) to deltaV(CO2) was significantly elevated in class III patients, although there was no difference in the ratio of deltaVA to deltaV(CO2) among the four groups. Rest and exercise arterial P(CO2) did not differ among the four groups and was controlled within the normal range. The increase in arterial potassium (deltaK+) from rest to peak exercise was markedly reduced as the severity of CHF advanced: (mean +/- SD) 1.70+/-0.32 mmol/L in normal subjects; 1.46+/-0.27 mmol/L in class I patients; 1.15+/-0.24 mmol/L in class II patients; and 0.78+/-0.24 mmol/L in class III patients. The ratios of deltaVA or deltaV(CO2) to deltaK+ were not different among the four groups. The ratio of deltaV(E) to deltaK+, however, was significantly greater in patients in class III than in normal subjects or patients in class I or II. CONCLUSIONS: The deltaK+ from rest to peak exercise was markedly reduced as the severity of CHF advanced. The increased exercise ventilation due to increased physiologic dead space in severe CHF was not accompanied by the corresponding augmentation of exercise-induced hyperkalemia. Exercise-induced hyperkalemia does not contribute to the increased ventilatory drive to keep normal arterial P(CO2) during exercise in the presence of increased physiologic dead space in severe CHF.

Exercise↗

PubMed1999

Dynamics of astrocyte adhesion as analyzed by a combination of atomic force microscopy and immuno-cytochemistry: the involvement of actin filaments and connexin 43 in the early stage of adhesion.

We observed the time-dependent morphological alteration of astrocytes during their adhesion by atomic force microscopy (AFM) and investigated the relationships between this morphological alteration and the localization of actin filaments and connexin 43 by immunocytochemistry. The fine processes observed as fine ridge-like structures by AFM were closely concerned with actin filaments by immunocytochemistry. During the adhesion of astrocytes, actin filaments appeared to be aligned regularly beyond the borders among different cells. Detectable connexin immunoreactivity was changed in the following regions: 1) the tips of fine cell processes and the cell margin when astrocytes started to adhere; 2) the border of cells when astrocytes tightly adhered; and 3) non-specific sites when astrocytes became a cluster. In the former two cases, the immunopositive spots for connexin were observed to colocalize with the tips of cell processes with actin filaments. These results strongly suggest that connexin associated with actin filaments at the tip of cell processes plays an important role in the early stage of the adhesion of astrocytes. These observations afford valuable clues for understanding the glial communication.

Actin Cytoskeleton↗

PubMed1999

Nuclear localization of beta-catenin in normal and carcinogenic endometrium.

We have previously shown that the connexin (Cx) 26 and 32 genes are expressed during the secretory phase of the human endometrium and that their expression is downregulated during the proliferative phase, suggesting a role for intercellular transduction in cell growth control in human endometrium. To further study the possible role of cell-to-cell interaction in growth regulation, we immunohistochemically analyzed 80 endometrial samples (30 of normal endometrium, 20 of endometrial hyperplasia, and 30 of endometrial cancer) for the expression of E-cadherin; alpha-, beta-, and gamma-catenin; adenomatous polyposis coli (APC) protein, and sex-steroid hormone receptors at three points in the cells: the cell-to-cell border, the cytoplasm, and the nucleus. In this study, moderate or strong staining of beta-catenin in the nuclei was observed in 60.0% of endometrial hyperplasia samples and 30.0% of endometrial cancer samples, although the beta-catenin gene was mutated in only two of the nine samples that showed the intensive nuclear staining. Western blotting analysis showed that the samples that had intense nuclear staining of beta-catenin had much higher expression of beta-catenin than the samples that did not have nuclear staining. Furthermore, normal endometrium showed nuclear localization, especially in the mid- and late-proliferative and early-secreting phases of the menstrual cycle. The results suggest that the nuclear localization of beta-catenin observed in endometrial hyperplasia and endometrial cancer, as in other tumors, implies that beta-catenin/Wnt-1 signal transduction is highly activated in carcinogenesis of the endometrium as well as in normal physiological conditions.

Base Sequence↗

PubMed1999

Antifungal activity of human polymorphonuclear leucocytes against yeast cells of Paracoccidioides brasiliensis.

Human peripheral blood polymorphonuclear leucocytes (PMN) were examined in vitro for antifungal activity against yeast cells of Paracoccidioides brasiliensis. The yeast cell of this fungus was resistant to killing by PMN. However, PMN exhibited a fungistatic effect on the fungal isolates employed in a long-term ( approximately 72 h) assay. Lysates of PMN did not show a fungistatic or fungicidal effect, indicating that live PMN are necessary for the antifungal effect. Interferon-Gamma (IFN-Gamma) enhanced the antifungal activity of PMN. IFN-Gamma-treated PMN killed isolate Bt-4 within 2 h of coculture, and after 24 h a still greater killing effect was observed. By contrast, IFN-Gamma-treated PMN did not show a significant killing effect on isolate Tatu, but did exhibit an enhanced fungistatic effect on this isolate. In contrast, tumor necrosis factor-alpha and interleukin 8 had no effect on the antifungal activity of PMN. Scanning electron microscopy revealed that the surface structure of the fungal cell was apparently damaged by PMN within 24 h of cocultures. Based on these novel findings, we speculate that human PMN might play a role in host resistance in early infection with this fungus due to their antifungal activity.

Cell Division↗

PubMed1999

[Does the present medical care system satisfy patients with home oxygen therapy (HOT) and home therapy with assisted ventilation (HTAV) in Japan?: an answer from a questionnaire analysis].

The aim of this study was to determine whether the present Japanese medical care system for home oxygen therapy (HOT) and home therapy with assisted ventilation (HTAV) satisfies patients (HOT & HTAV Pts) who receive these therapies. To clarify this issue, we sent questionnaires to 807 patients with HOT and HTAV, 816 practitioners (DRs), and 110 nursing stations (NSs) in metropolitan Tokyo. Responses were eventually received from 79.9% of HOT & HTAV Pts, 32.7% of Drs and 60.9% of NSs. As a result, going to hospitals on regular basis itself (1.3 times a month) forces HOT & HTAV Pts to spend a lot of money and time at present (22.4% spent more than 5,000 yen, and 15.5% more than 60 minutes for a consultation). Although a majority of HOT & HTAV Pts now see a respiratory specialist in larger hospitals, HOT & HTAV Pts wish to see DRs, if the DRs have sufficient ability in HOT and HTAV management. On the other hand, both DRs (86.9%) and NSs (90.6%) consider that case conferences and lectures regarding HOT and HTAV on a regular basis are essential. These meetings are attended by respiratory specialists, DRs, NSs, medical equipment dealers, HOT & HTAV Pts's family members and so forth, because both DRs and NSs feel a certain anxiety about seeing HOT & HTAV Pts (68.3% DRs and 7.5% NSs do not want to see HOT & HTAV Pts). In summary, 1) a majority of HOT & HTAV Pts remain unsatisfied with the present medical care system, 2) a vague anxiety about seeing HOT & HTAV Pts makes DRs tend to avoid HOT & HTAV Pts consultations, 3) NSs frequently feel unsure how to recognize and respond properly to problems concerning HOT & HTAV Pts (62.3%). We therefore conclude that if we could succeed in organizing a better medical care system for HOT & HTAV Pts than the present one, we could turn substantially improve the quality of life of HOT & HTAV Pts in Japan.

Home Care Services, Hospital-Based↗

PubMed1998

Climate and vegetation history of the midcontinent from 75 to 25 ka: A speleothem record from crevice cave, missouri, USA

Four Missouri stalagmites yield consistent overlapping records of oxygen and carbon isotopic changes and provide a climate and vegetation history with submillennial resolution from 75 to 25 thousand years ago (ka). The thorium-230-dated records reveal that between 75 and 55 ka, the midcontinental climate oscillated on millennial time scales between cold and warm, and vegetation alternated among forest, savanna, and prairie. Temperatures were highest and prairie vegetation peaked between 59 and 55 ka. Climate cooled and forest replaced grassland at 55 ka, when global ice sheets began to build during the early part of Marine Oxygen Isotope Stage 3.

Journal Article↗

PubMed1998

Marginal benefit/disadvantage of granulocyte colony-stimulating factor therapy after autologous blood stem cell transplantation in children: results of a prospective randomized trial. The Japanese Cooperative Study Group of PBSCT.

In this prospective trial, a total of 74 children who were scheduled to undergo high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT) were prospectively randomized at diagnosis to evaluate the effectiveness of exogenous granulocyte colony-stimulating factor (G-CSF) treatment in accelerating hematopoietic recovery after PBSCT. The diagnosis included acute lymphoblastic leukemia (ALL) (n = 27), neuroblastoma (n = 29), and miscellaneous solid tumors (n = 18). Eligibility criteria included (1) primary PBSCT, (2) chemotherapy-responsive disease, and (3) collected cell number >1 x 10(5) colony-forming unit-granulocyte-macrophage (CFU-GM)/kg and >1 x 10(6) CD34(+) cells/kg patient's body weight. After applying the above criteria, 11 patients were excluded due to disease progression before PBSCT (n = 6) or a low number of harvested cells (n = 5), leaving 63 patients for analysis; 32 patients in the treatment group (300 microg/m2 of G-CSF intravenously over 1 hour from day 1 of PBSCT) and 31 in the control group without treatment. Two distinct disease-oriented high-dose regimens without total body irradiation consisted of the MCVAC regimen using ranimustine (MCNU, 450 mg/m2), cytosine arabinoside (16 g/m2), etoposide (1.6 g/m2), and cyclophosphamide (100 mg/kg) for patients with ALL, and the Hi-MEC regimen using melphalan (180 mg/m2), etoposide (1.6 g/m2), and carboplatinum (1.6 g/m2) for those with solid tumors. Five patients (two in the treatment group and three in the control group) were subsequently removed due to protocol violations. All patients survived PBSCT. The median numbers of transfused mononuclear cells (MNC), CD34(+) cells, and CFU-GM were, respectively, 4.5 (range, 1 to 19) x 10(8)/kg, 8.0 (1.1 to 25) x 10(6)/kg, and 3.7 (1.2 to 23) x 10(5)/kg in the treatment group (n = 30) and 2.9 (0.8 to 21) x 10(8)/kg, 6.3 (1.1 to 34) x 10(6)/kg, and 5.5 (1.3 to 37) x 10(5)/kg, respectively, in the control group (n = 28), with no significant difference. After PBSCT, the time to achieve an absolute neutrophil count (ANC) of >0.5 x 10(9)/L in the treatment group was less than that in the control group (median, 11 v 12 days; the log-rank test, P =.046), although the last day of red blood cell (RBC) transfusion (day 11 v day 10) and the duration of febrile days (>38 degrees C) after PBSCT (4 v 4 days) were identical in both groups. However, platelet recovery to >20 x 10(9)/L was significantly longer in treatment group than control group (26 v 16 days; P =.009) and >50 x 10(9)/L tended to take longer in the treatment group (29 v 26 days; P =.126), with significantly more platelet transfusion-dependent days (27 v 13 days; t-test, P =.037). When patients were divided into two different disease cohorts, ALL patients showed no difference in engraftment kinetics between the G-CSF treatment and control groups, while differences were seen in those with solid tumors. We concluded that the marginal clinical benefit of 1 day earlier recovery of granulocytes could be offset by the delayed recovery of platelets. We recommend that the routine application of costly G-CSF therapy in children undergoing PBSCT should be seriously reconsidered.

Adolescent↗

PubMed1998

Effect of percutaneous transvenous mitral commissurotomy on postexercise breathlessness as determined by ventilation during recovery from constant workload exercise.

We evaluated the effect of percutaneous transvenous mitral commissurotomy (PTMC) on ventilatory variables and dyspnea during recovery from a 6-minute submaximal constant workload exercise, and showed that the decrease in postexercise ventilation after PTMC was closely related to improvement in postexercise dyspnea after PTMC. Ventilation during recovery from submaximal constant workload exercise is related to postexercise breathlessness and can be used to assess the effectiveness of therapeutic interventions.

Adult↗

PubMed1998

Enhancement of cell death due to decrease in Mg2+ uptake by OmpC (cation-selective porin) deficiency in ribosome modulation factor-deficient mutant.

Ribosome modulation factor (RMF) is involved in stabilization of ribosomes during the transition from exponential growth to the stationary growth phase in Escherichia coli. A deficiency of RMF is known to reduce cell viability. Overaccumulation of spermidine also leads to a decrease in cell viability and to a decrease in the synthesis of RMF and of the cation-selective porin OmpC. Thus, a decrease in RMF levels may be involved in the decreased cell viability caused by excess spermidine. Because spermidine also influences the expression of OmpC, we examined whether OmpC deficiency enhances the cell death caused by RMF deficiency. The ompC mutant by itself did not affect protein synthesis or cell viability, but the double rmf ompC mutant produced a much larger decrease in protein synthesis and cell viability than did the single rmf mutant. There was also a decrease in the amount of ribosomes and in the Mg2+ content in the double rmf ompC mutant, and cell viability could be partially restored by the addition of Mg2+ to the growth medium. RMF deficiency was found to inhibit the synthesis of another cation-selective porin OmpF. Thus, the double rmf ompC mutant is deficient in both OmpC and OmpF, which probably accounts for the pronounced decrease in Mg2+ uptake in this mutant. The results indicate that both RMF and Mg2+, acting through stabilization of ribosomes, are important for cell viability at the stationary growth phase.

Bacterial Outer Membrane Proteins↗

PubMed1998

Sensory preconditioning for feeding response in the pond snail, Lymnaea stagnalis.

We demonstrated a sensory preconditioning in the pond snail, Lymnaea stagnalis. An appetitive sucrose solution (a conditioned stimulus: CS1) and weak vibration (another conditioned stimulus: CS2) were first associated, and then the CS2 and an aversive KCl solution (an unconditioned stimulus: UCS) were done. To build the conditioning, two different training procedures, spaced and massed, were examined. After the both training, the sensory preconditioning was built: significantly fewer feeding response to the CS1 became elicited; slower latency to the first bite to the CS1 was induced. No significant differences on the memory retention between these training procedures were found in the sensory preconditioning.

Animals↗

PubMed1998

Roles of A- and D-type K channels in EPSP integration at a model dendrite.

We examined the roles of A- and D-type K channels in the integration of EPSPs, particularly EPSP reduction, in a model dendrite using a computer simulation program (NEURON), instead of conventional electrophysiological methods which present technical difficulties. We obtained two important results: (1) KD channels play a crucial role in every synaptic input event, and (2) KA channels affect reduction of the second EPSP only when the second synaptic input is applied with a short interval (<100 ms). These results suggest that KD channels, which have not yet been analyzed experimentally, play a major role in synaptic integration in dendrites by altering their cable properties.

Animals↗

PubMed1998

The entropy generation in visual-pigment system by the absorption of light.

We first showed a general theory that reception of information from the outside in a receptor system is accompanied both by an inflow of entropy and by a generation of entropy depending on the reliability of the actual reception mechanism. Then, considering a case for the absorption of light by the visual-pigment system of visual cell, we calculated the time(t)-dependent change in the number N2(t) of excited visual-pigments to obtain the entropy increase. We thus arrived at the following four conclusions: (1) One or two photons can be detected with a reliability of at least 54%; (2) In compensation for this detection, entropy > 1.12 x log2 is generated; (3) An incident photon of frequency v from a ligh source of temperature Ts yields an entropy of hv/Ts; and (4) Depending on the characteristics of the visual-pigment system, another entropy being different from (2) is generated in proportion to N2(t).

Absorption↗

PubMed1998

Identification of the hydrophobic amino acid residues required for heme assembly in the rhizobial oxygen sensor protein FixL.

Rhizobial FixL is a novel heme protein, which senses environmental oxygen tension and directs signal transduction via protein phosphotransfer. To identify the essential residues for heme assembly in Rhizobium meliloti FixL, we individually replaced the 18 invariant hydrophobic amino acid residues (F, I, L, and V) in the heme-containing domain with alanine and histidine. Spectroscopic measurements of the soluble fractions from fixL recombinant Escherichia coli revealed that V152, F162, F170, I172, L185, F226, L230, and F243 as well as the proximal ligand H194 were indispensable for heme assembly. Autoxidation rates of purified I209H, I210A, and I210H were 65-fold, 15-fold, and 15-fold, respectively, faster than that of the wild type, although they retained heme in the protein. The absorption peak in the Soret region of the ferric I209H or I210H was red-shifted, suggesting that the ferric heme is a hexa-coordinate form in these mutants.

Amino Acid Sequence↗

PubMed1998

Promoter analysis of the human mismatch repair gene hMSH2.

The human DNA mismatch repair gene homologue hMSH2 is involved in hereditary nonpolyposis colorectal cancer. We isolated and characterized the 5' upstream region, about 4.4kbp, of the hMSH2 gene. This region contains CpG islands and a number of elements involved in constitutive expression, but there is no TATA-box nearby the transcription start points. This is the typical structure for many promoters of housekeeping genes. Alu sequences and mononucleotide repeats are clustered in this region and there are two transcription start points. Deletion analysis revealed that less than 300bp was sufficient to initiate transcription. Although no mutation that influences promoter activity of this region was found, a polymorphism was detected by PCR-RFLP analysis. Because informative cases (C/T heterozygous) were relatively high ( approximately 30%), this polymorphism is suitable for a marker to examine allelic losses.

Alleles↗

PubMed1998

Isolation and characterization of the 5' region of the human mismatch repair gene hPMS1.

The hPMS1 gene encodes a mutL homolog that is implicated in DNA mismatch repair and was found to be mutated in the germline of a patient with hereditary nonpolyposis colorectal cancer (HNPCC). To understand transcriptional regulation and to perform mutational analysis in the promoter region, we cloned and characterized the genomic sequence of the 5' region of the gene. hPMS1 has an intron upstream of the initiation codon. There were several transcripts with alternative splicing sites and multiple transcriptional start sites. The cloned 1.4-kbp fragment of the 5' region contains a CpG island but no TATA-boxes, typical for promoters of housekeeping genes. The promoter activity of the fragment was almost equal to that of the SV40 early promoter. Deletion analysis showed that about a 300-bp region was sufficient to initiate transcription. Although we searched for mutations in the hPMS1 promoter region in HNPCC kindreds, neither germline nor somatic mutations were detected. However, we found a highly informative polymorphism in the first exon that is useful for searching allelic losses because no polymorphic changes in hPMS1 have been reported previously.

Alleles↗