Search PubMed⌕ Search

Biomedical subjects

E Ito

Publications and source records attributed to E Ito.

At least 91 records · Page 5Linked to original sources
PubMed2000

Clinical and pathophysiological features of amaurosis fugax in Japanese stroke patients.

OBJECTIVE: It has been emphasized that amaurosis fugax (AmF) is caused by thromboembolism due to atheromatous lesions of the extracranial carotid artery (EC-CA) in Caucasian populations. However, there have been few studies of AmF in Japan. We analyzed the clinical and pathophysiologic features of AmF in 43 Japanese AmF patients. SUBJECTS AND METHODS: Forty-three patients presented with AmF from a group of 2,056 Japanese patients with acute ischemic stroke. We investigated angiographic and transcranial Doppler findings, precipitating factors, medical treatment and prognosis, to elucidate the pathogenetic mechanism of AmF. RESULTS: Angiographic findings revealed an intracranial lesion in 22 patients (51%), extracranial lesion in 16 (37%), and no abnormality in 5 (12%). Blood flow in the ophthalmic artery (OA) examined by the transcranial Doppler ultrasonography (TCD) showed normal antegrade flow in 24 patients and reversed flow in 7. Precipitating factors for AmF were seen in 7 out of 43 patients. Regarding the pathogenesis of AmF, the micro-thromboembolism originated from the internal carotid artery (ICA) in 25 patients, the thromboembolism was via the external carotid artery (ECA) in 7, the hemodynamic retinal vascular insufficiency in 6 patients showed various atheromatous changes in the intracranial carotid artery (IC-CA) or EC-CA, and the cause was unknown in 5. CONCLUSION: In this series of patients, AmF was mainly caused by thromboembolism from IC-CA atheromatous lesions. Micro-thromboemboli from the ECA or hemodynamic retinal vascular insufficiency, although less frequent, should also be considered as possible etiologies for AmF.

Adolescent↗
PubMed2000

[Effects of oral 5-HT3 antagonists on chemotherapy-induced emesis in patients with gynecologic cancers].

The efficacy of an intravenous 5-HT3 antagonist (granisetron) and four oral 5-HT3 antagonists (granisetron, ondansetron, tropisetron and ramosetron) on chemotherapy-induced emesis were investigated in 21 gynecologic cancer patients (63 courses). The severity of emesis after chemotherapy was classified in 4 grades (0: none, 1: slight loss of appetite, 2: severe loss of appetite, but tolerable, and 3: untolerable). The effect of 5-HT3 antagonists was judged by both the score for the severity of the emesis and the frequency of vomiting. The four oral 5-HT3 antagonists were almost the same in efficacy for 5 days after chemotherapy. Oral 5-HT3 antagonists were almost equipotent to intravenous granisetron for JT (paclitaxel + carboplatin) therapy or T (paclitaxel) therapy for 5 days after chemotherapy. However, they were ineffective for CAP (cisplatin + adriamycin + cyclophosphamide) therapy. From these results, oral 5-HT3 antagonists were proved to have a sufficient anti emetic effect after chemotherapy in cases of JT or T therapy. However, in cases of CAP therapy, intravenous 5-HT3 antagonists were thought to be preferable for the control of emesis due to chemotherapy.

Administration, Oral↗
PubMed2000

Fatal Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis with clonal karyotype abnormality.

We report a case of Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH) with clonal karyotype abnormality. A 5-year-old boy was admitted to our hospital with persistent high-grade fever, hepatomegaly, and pancytopenia. Laboratory data disclosed a coagulation abnormality and severe liver damage. Clonal proliferation of EBV-infected cells was detected in the bone marrow by Southern hybridization, and bone marrow cells exhibited clonal chromosomal abnormality. Although the patient was treated with immunochemotherapy according to the HLH94 protocol, the disease recurred during the induction therapy, and the patient died of disseminated intravascular coagulopathy. Considering this aggressive and fatal clinical course, it is important to take intensive therapeutic measures if karyotype abnormality is noted in the treatment of EBV-HLH patients.

Bone Marrow Cells↗
PubMed2000

[Polysomnography].

Polysomnography(PSG) is essential for the diagnosis of all pathophysiologic conditions due to both any types of sleep disordered breathing and to any types of sleep disturbance. Since this issue's objection is to describe the outline of PSG, we will explain here about when PSG is needed, what type of measurements are necessary for PSG, and how it should be interpreted from the result of the PSG tracing for the diagnosis for sleep apnea syndrome, etc.

Diagnosis, Differential↗
PubMed2000

Radiofrequency induction heating for the treatment of aortic dissection in an animal model.

BACKGROUND: In this study, radiofrequency (RF) induction heating therapy using a self-expanding Gianturco metallic stent (G-EMS) to treat acute aortic dissection was evaluated. METHODS: We evaluated convergent RF induction heating of G-EMS in pigs. In group A (n=3), an aortic dissection was created to determine the natural course of this lesion. In group B (n=4), 0.40 mm stainless steel bare G-EMSs (2.5 cm, 10 bends) were placed in the aorta 5 to 7 days after dissection, and RF induction heating was performed for 30 (n=2) or 45 (n=2) minutes. In group C (n=6), G-EMSs with 0.10 mm ferro-chrome wire mounted on alternating stent legs were placed in the aorta 1 to 7 days after dissection, and RF induction heating was performed for 10 minutes. RESULTS: In group A, 2 pigs died from rupture of the false lumen. In group B, fusion of the dissection flap was confirmed histologically. However, all of the pigs died. In group C, all of the pigs tolerated the procedure, and fusion of the dissection flap was confirmed in all of the pigs. CONCLUSIONS: This experimental animal study suggested that RF induction heating combined with G-EMS, if properly applied, has a potential to treat acute aortic dissection.

Aortic Dissection↗
PubMed2000

[Objective evaluation of treatment for sleep apnea syndrome].

CPAP treatments for sleep apnea syndrome (SAS) are being established; however, there is no established evaluation method to scale the long-lasting effectiveness of the treatment. The only available method is to judge the results from each patient's subjective symptoms. We therefore tested a self-contained microcomputer with an acceleration sensor (Lifecorder) in an attempt to evaluate the effectiveness of treatments objectively. Fifteen patients with OSAS were the subjects. We keep the records of Lifecorders that were worn by the subjects a month before and a month after nasal CPAP treatment. We also assessed their daily physical activity levels; the number of steps taken, calories consumed, intensity of each activity along with improvement in their subjective symptoms. The number of steps taken in a day increased as did the calories consumed after treatment in 9 subjects. Moderate and intensive activities also increased among those 9 subjects. Our results indicate that evaluation with a Lifecorder, which is simple and inexpensive, can provide objective indicators to assess the effectiveness of treatments in patients' daily activities.

Adult↗
PubMed1999

Fluorescence correlation spectroscopy analysis of the hydrophobic interactions of protein 4.1 with phosphatidyl serine liposomes.

Fluorescence correlation spectroscopy (FCS) was applied to examine the interactions between a protein and a membrane lipid. The protein 4.1-phosphatidyl serine (PS) interactions served as the model system to demonstrate the membrane lipid-protein interactions. This protein was labeled with rhodamine and its interactions with PS-liposomes were measured by FCS. The present results clearly demonstrated that a small protein molecule, protein 4.1, interacts specifically with a large particle, a PS-liposome. This interaction appears to be hydrophobic and not electrostatic, since the bound protein 4.1 did not dissociate in solution and was specifically released from PS-liposomes by treatment with phospholipase A(2) (PLA(2)). In the present study, using FCS we could demonstrate that the serine residue of PS is required for protein 4.1 to bind to PS-liposomes and that the bound protein 4.1 is closely associated with the fatty acid of the PS molecule in the liposomes.

Journal Article↗
PubMed1999

Transcriptional coupling between the divergent promoters of a prototypic LysR-type regulatory system, the ilvYC operon of Escherichia coli.

The twin-domain model [Liu, L. F. & Wang, J. C. (1987) Proc. Natl. Acad. Sci. USA 84, 7024-7027] suggests that closely spaced, divergent, superhelically sensitive promoters can affect the transcriptional activity of one another by transcriptionally induced negative DNA supercoiling generated in the divergent promoter region. This gene arrangement is observed for many LysR-type-regulated operons in bacteria. We have examined the effects of divergent transcription in the prototypic LysR-type system, the ilvYC operon of Escherichia coli. Double-reporter constructs with the lacZ gene under transcriptional control of the ilvC promoter and the galK gene under control of the divergent ilvY promoter were used to demonstrate that a down-promoter mutation in the ilvY promoter severely decreases in vivo transcription from the ilvC promoter. However, a down-promoter mutation in the ilvC promoter only slightly affects transcription from the ilvY promoter. In vitro transcription assays with DNA topoisomers showed that transcription from the ilvC promoter increases over the entire range of physiological superhelical densities, whereas transcription initiation from the ilvY promoter exhibits a broad optimum at a midphysiological superhelical density. Evidence that this promoter coupling is DNA supercoiling-dependent is provided by the observation that a novobiocin-induced decrease in global negative superhelicity results in an increase in ilvY promoter activity and a decrease in ilvC promoter activity predicted by the in vitro data. We suggest that this transcriptional coupling is important for coordinating basal level expression of the ilvYC operon with the nutritional and environmental conditions of cell growth.

Bacterial Proteins↗
PubMed1999

The promoter region of human prepro-nociceptin gene and its regulation by cyclic AMP and steroid hormones.

The promoter and upstream regulatory region of the human prepro-nociceptin gene has been cloned from adaptor-ligated genomic DNA libraries by polymerase chain reaction. This 1.7 kb region contains several potential binding sites for transcription factors, among which are binding sites for TF-IID, cyclic AMP response element binding protein, glucocorticoid receptor and estrogen receptor. Multiple start points for the transcription of prepro-nociceptin are identified by an 'oligoribonucleotide-capping' method, but the major one is located at -558(G). Promoter activity assays using luciferase reporter gene constructions with the 1.7 kb fragment and a series of deletion mutations demonstrate that the core promoter is located in the region from -639 to -521 (a region surrounding the major transcription start point -558). A TATA-box motif displays weak promoter activity. An increase of cellular cyclic AMP levels by forskolin treatment up-regulates prepro-nociceptin transcription. Estrogen also up-regulates gene transcription whereas glucocorticoid down-regulates transcription, each through their corresponding receptor response elements. These regulatory effects can be blocked either by mutations of the potential cyclic AMP- or estrogen receptor response elements or by the application of antagonists for glucocorticoid and estrogen receptors. These findings provide a molecular basis for the regulatory mechanisms of human prepro-nociceptin gene expression.

Base Sequence↗
PubMed1999

Efficacy of the mobilization of peripheral blood stem cells by granulocyte colony-stimulating factor in pediatric donors.

The advantages/disadvantages of the use of peripheral blood stem cells (PBSCs) for allogeneic transplantation still need to be clarified, particularly in children. We compared the kinetics, efficacy, and safety of PBSC mobilization by granulocyte colony-stimulating factor (G-CSF) and collection by apheresis between healthy pediatric and adult donors. A total of 19 pediatric (median age, 6 years) and 25 adult healthy donors (median age, 37 years) were given 10 micro/kg/day of G-CSF for 5 consecutive days for PBSC mobilization, which were harvested by apheresis on days 5 and/or 6. All of the donors tolerated the whole procedures. Serum trough levels of G-CSF determined by ELISA were significantly lower in the 16 pediatric donors evaluated than in adults (n = 16) on days 3 and 4 (P < 0.05). Although the WBC counts on days 4 and 5 were significantly higher in adults than in children (P = 0.006 and 0.004, respectively), the numbers of circulating CD34+ cells/unit of blood were identical. The number of blood CD34+ cells collected per unit of blood processed was identical in both donor populations. We propose that PBSCs could be effectively mobilized and collected in small children so that they could be donors for adult patients.

Adolescent↗
PubMed1999

Optical detection of synaptically induced glutamate transport in hippocampal slices.

Although it has long been believed that glial cells play a major role in transmitter uptake at synapses in the CNS, the relative contribution of glial and neuronal cells to reuptake of synaptically released glutamate has been unclear. Recent identification of the diverse glutamate transporter subtypes provides an opportunity to examine this issue. To monitor glutamate transporter activity, we optically detected synaptically induced changes of membrane potential from hippocampal CA1 field in slice preparations using a voltage-sensitive dye, RH155. In the presence of ionotropic glutamate-receptor blockers, synaptic inputs gave rise to a slow depolarizing response (SDR) in the dendritic field. The amplitude of SDR correlated well with presynaptic activities, suggesting that it was related to transmitter release. The SDR was found to be caused by the activities of glutamate transporters because it was not affected by blockers for GABAA, nACh, 5-HT3, P2X, or metabotropic glutamate receptors but was greatly reduced by dihydrokainate (DHK), a specific blocker for GLT-1 transporter, and by D, L-threo-beta-hydroxyaspartate (THA), a blocker for EAAC, GLAST, and GLT-1 transporters. When SDR was detected with RH482 dye, which stains both glial and neuronal cells, 1 mM DHK and 1 mM THA were equally effective in suppressing SDR. The SDR was very small in GLT-1 knockout mice but was maintained in gerbil hippocampi in which postsynaptic neurons were absent because of ischemia. Because GLT-1 transporters are exclusively expressed in astrocytes, our results provide direct evidence that astrocytes play the dominant role in sequestering synaptically released glutamate.

ATP-Binding Cassette Transporters↗
PubMed1999

A core promoter and a frequent single-nucleotide polymorphism of the mismatch repair gene hMLH1.

The hMLH1 gene encodes a protein that is involved in the DNA mismatch repair system. The coding region of the hMLH1 gene has been known to be mutated in a subset of patients with hereditary nonpolyposis colorectal cancer (HNPCC). Our current research characterized the promoter region of the hMLH1 gene and searched for mutations correlating to HNPCC. Utilizing the oligo-capping method, major transcription start sites of the hMLH1 gene were mapped at two locations. The core promoter region of about 180 bp was determined by the luciferase assay of serial deletion mutants. Although we did not find any pathogenic mutation in the hMLH1 promoter region by PCR-SSCP, we found a single-nucleotide polymorphism at position -93 nt from the adenine residue of the start codon. By PCR-RFLP analysis with Pvu II for this polymorphism, we detected LOH in four tumors from three patients. An easy detection of this polymorphism with PCR-RFLP and high incidence ( approximately 50%) of informative cases make this polymorphism a suitable marker for the detection of hMLH1 allelic losses.

3T3 Cells↗
PubMed1999

Molecular cloning and functional characterization of a new Cap'n' collar family transcription factor Nrf3.

The NF-E2-binding sites or Maf recognition elements (MARE) are essential cis-acting elements in the regulatory regions of erythroid-specific genes recognized by the erythroid transcription factor NF-E2, composed of p45 and MafK. Recently, two p45-related factors Nrf1 and Nrf2 were isolated, and they are now collectively grouped as the Cap'n' collar (CNC) family. CNC factors bind to MARE through heterodimer formation with small Maf proteins. We report here the identification and characterization of a novel CNC factor, Nrf3, encoding a predicted 73-kDa protein with a basic region-leucine zipper domain highly homologous to those of other CNC proteins. In vitro and in vivo analyses showed that Nrf3 can heterodimerize with MafK and that this complex binds to the MARE in the chicken beta-globin enhancer and can activate transcription. Nrf3 mRNA is highly expressed in human placenta and B cell and monocyte lineage. Chromosomal localization of human Nrf3 is 7p14-15, which lies near the hoxA gene locus. As the genetic loci of p45, nrf1, and nrf2 have been mapped close to those of hoxC, hoxB, and hoxD, respectively, the present study strongly argues for the idea that a single ancestral gene for the CNC family members may have been localized near the ancestral Hox cluster and have diverged to give rise to four closely related CNC factors through chromosome duplication.

Amino Acid Sequence↗
PubMed1999

Two short sequences have positive effects on the human p27Kip1 gene transcription.

The cyclin-dependent kinase (Cdk) inhibitor p27Kip1 plays an important role in the progression from G1 to S phase in the cell cycle. To study the activities of its promoter and other regulatory elements, we have cloned and characterized the 5'-flanking region of the human p27Kip1 gene. This region, about 3kb in length, is GC-rich and shares homology with that of the mouse p27Kip1 gene. Transcription start points (tsp) determined by the oligo-capping method are mapped in two regions, the cluster I (-479 to -403) and cluster II (-280 to -273). The cluster I was the primary functional site in transcription initiation. The luciferase activities of serial deletion mutants indicated that two short sequences (-581 to -557 and -556 to -526) had positive effects on transcription. The gel shift assay showed that factors in HeLa nuclear extract bound to these sequences. Sp1 was the major binding factor to the sequence of -556 to -526, wheres yet unidentified positive factors bound to the sequence of -581 to -557.

Base Sequence↗
PubMed1999

Effects of electrical stimulation of the tentacular digits of a slug upon the frequency of electrical oscillations in the procerebral lobe.

To find the primary mechanism for the frequency changes of electrical oscillations in the procerebral (PC) lobe of a slug, we electrically stimulated the tip, middle and basal regions of the digits of the superior and inferior tentacles and recorded the local field potentials from the PC lobe. Stimuli to the middle and basal regions of the digits of the inferior tentacle significantly decreased the frequency of electrical oscillations in the PC lobe, whereas those to the tip regions of the digits of the inferior tentacle and all regions of the digits of the superior tentacle increased it. These findings suggest that the change in the frequency of electrical oscillations in the PC lobe depends on the excited region in the digits, providing the first presentation of the physiological difference in the olfactory function between the superior and inferior tentacles.

Animals↗
PubMed1999

Comparison of maitotoxin with thromboxane A2 in rabbit platelet activation.

Maitotoxin (MTX), a Ca2+ channel-activating marine toxin, caused shape change followed by aggregation in rabbit platelets, like U46619, a thromboxane A2 analogue. Although both drugs failed to cause aggregation in the absence of external Ca2+, U46619, but not maitotoxin, elicited shape change in the absence of external Ca2+. The observations of platelets with a scanning electron microscope showed that both drugs caused contraction of platelets and extension of pseudopodia (shape change) followed by aggregation with a clot in the presence of Ca2+. It is noteworthy that long term exposure to MTX caused the lysis of platelets in the presence of Ca2+. While U46619 transiently increased the internal Ca2+ concentration ([Ca2+]i), maitotoxin slowly but irreversibly increased [Ca2+]i in an external Ca2(+)-dependent manner. MTX-induced phosphoinositide hydrolysis was totally dependent on the presence of external Ca2+, but U46619-induced phosphoinositide hydrolysis was still observed in the absence of external Ca2+. MTX-induced phosphoinositide hydrolysis was partly inhibited by SK&F96365, a voltage-independent Ca2+ channel antagonist, or by genistein, a tyrosine kinase inhibitor. MTX caused phosphorylation of tyrosine residues of several proteins, like U46619. Thus, MTX is similar to U46619 in functions of Ca2+ mobilization, phosphoinositide hydrolysis and tyrosine phosphorylation, but MTX-induced actions are strictly dependent on the presence of external Ca2+.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1999

Histological characterization of lip and tentacle nerves in Lymnaea stagnalis.

The lip and tentacle nerves of the pond snail, Lymnaea stagnalis, were characterized using histological techniques. Anatomical drawings showed the detailed distributions of the superior lip, median lip, and tentacle nerves in the lip and tentacle; in particular it was found that the mouth is mainly innervated by the superior lip nerve. The tentacle nerve was clarified to form a zigzag structure along the extension direction in a shrinking tentacle. By backfilling of the superior lip nerve and/or the median lip nerve with fluorescent dyes, the neurons in the CNS made some clusters, whereas those stained from the tentacle nerve made other clusters. These stained neurons were not part of the central pattern generator or its regulatory neurons for feeding. The present results, therefore, suggest that the superior lip nerve may be employed as a principal factor in the chemosensory transduction from the mouth, and that no direct inputs occur through the lip and tentacle nerves to the central pattern generator or its regulatory neurons for feeding.

Animals↗