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Biomedical subjects

Y Maeda

Publications and source records attributed to Y Maeda.

At least 559 records · Page 31Linked to original sources
PubMed1994

[A case of emergency carotid endarterectomy to cope with vertebrobasilar insufficiency].

This is a report of an emergency carotid endarterectomy preformed on a 59 year-old male. He had been suffering from TIA of vertebrobasilar insufficiency since 1 day prior to admission. Angiography revealed severe stenosis and ulceration of the left cervical carotid bifurcation and occlusion of the bilateral vertebral arteries. Six hours after angiography, he showed hemiparesis, decerebrated posture and consciousness disturbance. These neurological signs were considered to be derived from occlusion of the left carotid bifurcation and disappearance of the collateral circulation via the left posterior communicating artery. Emergency carotid endarterectomy was performed to prevent brain infarction of the anterior and posterior circulation. Postoperative angiography showed disappearance of the stenosis of the carotid bifurcation and the recanalization of the left vertebral artery, and of the atherosclerotic stenosis of the left intracranial vertebral artery. It was considered that the left vertebral artery had been occluded by growth of a local thrombosis at the left intracranial vertebral artery.

Arterial Occlusive Diseases↗
PubMed1994

Regulation of cell differentiation and pattern formation in Dictyostelium development.

Free-living cells of Dictyostelium discoideum aggregate to form a slug-shaped cell mass and differentiate into prestalk and prespore cells. The differentiation of prespore cells is characterized by expression of Dp87 gene, the earliest event of prespore differentiation. It encodes a protein which first appears in ER of aggregating cells in a precursor form, is then translocated to prespore vacuoles and modified to a mature form and finally exocytosed to constitute the sorus matrix. The transcription of Dp87 is regulated by the cis-acting region consisting of positive, prespore-specific, negative, non-prespore-specific and positive, cell-type-non-specific elements. Cells expressing Dp87 appear at random in early aggregation streams and centers and then sort out to the posterior part of the slug. Intercellular signals required for prestalk and prespore differentiation were investigated by incubation at a low cell density of disaggregated cells. cAMP is inhibitory at the first and second stages of prespore differentiation, while it is required at the third stage. The stalk differentiation is divided into four stages: cAMP is required at the second stage and differentiation inducing factor (DIF) at the third stage, where a low molecular weight secretory substance is also required. At the third stage, cAMP inhibits both ecmA and ecmB expression, while 8-Br-cAMP specifically induces ecmB and maturation of prestalk to stalk cells. The relationship between the differentiation tendency of preaggregative cells and the cell-cycle phase at the initiation of development was studied by the use of cells synchronized for growth by a temperature-shift method.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Detection of minimal residual disease using clonospecific primers for CDRIII in patients with acute B lymphocytic leukemia with or without Philadelphia chromosome: possibility of clinical application as a tool for improving prognosis.

We attempted to identify the minimal residual leukemic clone as related to the clinical course in patients with acute B lymphocytic leukemia (B-ALL). DNA was extracted from stored bone marrow slides, and the third complementarity determining region (CDRIII) was amplified by polymerase chain reaction (PCR) using primers with consensus sequences for VH and JH. After amplification of the CDRIII band, the DNA fragment of CDRIII was inserted into the cloning vector PUC118. After cloning, the DNA sequences for CDRIII were determined. Clonospecific DNA sequences in CDRIII were selected, and clonospecific primers for each patient were synthesized. Using the clonospecific primers, we carried out second-round PCR to detect minimal residual disease (MRD) during several stages of the clinical course. Basically, the sensitivity of detection for MRD was between 10(-4) and 10(-5) cells. Even when leukemic cells were not detected in the morphologic study, with this detection system, the MRD was identified as an amplified CDRIII band stained with ethidium bromide on agarose gel. After bone marrow transplantation (BMT), MRD was detected for at least 4 months. In this article, we discuss the difference in sensitivity of detection for MRD between the BCR-ABL fusion gene and CDRIII in Philadelphia chromosome-positive (Ph+) B-ALL, as well as the possible clinical application of this method to predict relapse and prognosis.

Adolescent↗
PubMed1994

[Special cloth futon-cover (Miroguard) as a protection against house dust mite exposure].

We studied the efficacy of a special cloth encasing (Microguard) in protecting against house dust mite exposure. We vaccumed dust from right or left half surface of a shiki-futon (Japanese style mattress). Then we encased the shiki-futon by a new special encasing, vaccumed dust from the other part of the shiki-futon and got a pair of dust samples. We had done the same of the same shiki-futon by a used special encasing (used for one and half years) for about 2 weeks later. We prepared 7 shiki-futons and collected 14 pair dust samples. We weighed the dust and measured the mite allergens with a monoclonal antibody to Dermatophagoides pteronissynius and Dermatophagoides farinae. The dust level was 1.0% of the control (no encasing) in the new encasing group and 2.0% of the control in the used encasing group. The Der I concentration was 2.5 micrograms/(g dust) in the new encasing group and 3.2 micrograms/(g dust) in the used encasing group. The Der II concentration was 1.6 micrograms/(g dust). The total amount of Der I was 0.1% of the control in the new encasing group and 0.5% of the control in the used encasing group. The total amount of Der II was 0.2% of the control in the new encasing group and 0.7% of the control in the used encasing group. We compared Der p and Der f levels in the dust samples which we assayed and found no significant differences either in Der I or in Der II allergen. We concluded that Microguard was a useful tool to avoid mite allergen exposure by reducing not only the concentration of mite allergens but also the amount of dust.

Allergens↗
PubMed1994

[Fundamental studies on the measurement of urinary leukotriene E4].

We undertook fundamental studies on the measurement of urinary leukotriene E4, a stable end-product of peptidoleukotrienes, and obtained the following results. 1) After addition of 3H-LTE4 to 2 ml of urine, LTE4 was extracted with a commercial C18 mini-column, and purified by high performance liquid chromatography and then LTE4 in the elute was measured with an enzyme immunoassay kit. 2) As total recovery of LTE4 was 35.3 +/- 0.9% (n = 76), the amount of LTE4 was calculated after correction of the recovery with 3H-LTE4. 3) Before extraction of LTE4 by C18 column, the column was washed by ethyl acetate to remove interfering substances. This procedure greatly facilitated the following high performance liquid chromatographic analysis. 4) The basal levels of urinary LTE4 of seven aspirin-sensitive asthmatics were elevated as compared with five asthmatics without aspirin sensitivity (358.9 +/- 114.0 versus 77.9 +/- 47.3 pg/mg.cr; p < 0.05). 5) In two asthmatic patients, improvement of their symptoms was accompanied with decrease in the LTE4 level in urine. This method enabled us to measure LTE4 concentrations in a small volume of urine (2 ml), and would be useful for evaluating the pathogenesis of bronchial asthma.

Aspirin↗
PubMed1994

[Peritoneal dissemination of cecal cancer disappearing in a patient taking 5'-DFUR for 3 years].

A 51-year-old woman presenting with a left ovarian tumor underwent left oophorectomy and hysterectomy with intraperitoneal administration of cisplatin, cyclophosphamide, and 5-fluorouracil on December 13, 1989. Microscopically the tumor was well-differentiated adenocarcinoma. Postoperatively cecal cancer was detected. Laparotomy revealed multiple peritoneal dissemination on March 23, 1990, when palliative ileocecal resection was performed. Microscopy revealed several of the nodules to be adenocarcinoma and the cecal lesion well differentiated adenocarcinoma. The patient was then placed on 5'-deoxy-5-fluorouridine (800 subsequently 600 mg/day). In November, 1991, bright red blood per rectum led to the discovery of rectal cancer. On January 26, 1993, laparotomy revealed rectal tumor invading the bladder but the metastatic nodules on the peritoneum had disappeared. Thus pelvic exenteration was performed. The tumor was well-differentiated adenocarcinoma. The ovarian lesion may have been a metastasis from the cecal cancer, a so-called Krukenberg tumor. The rectal cancer was most likely to be asynchronous cancer. 5'-DFUR seemed effective in remitting the peritoneal dissemination.

Adenocarcinoma↗
PubMed1994

Relationship between anti-aversive effects of salmon calcitonin and plasma levels of ACTH, beta-endorphin and prostaglandin E2 in mice.

We investigated whether the anti-aversive effects of salmon calcitonin (SCT) was induced by increasing ACTH and beta-endorphin and/or by decreasing of prostaglandin E2 (PGE2) levels in plasma of mice to elucidate the mechanisms responsible for the analgesic effects of SCT. Intracerebroventricular (i.c.v.) injections of SCT inhibited acetic acid-induced aversive behavior (writhing) in a U-shaped dose response curve, the most effective dose being 0.1 IU/mouse. Intraperitoneal (i.p.) injections of acetic acid increased, but not significantly, the levels of plasma ACTH and PGE2, but not beta-endorphin, which are considered to be psychoneuroendocrines correlated with pain. SCT (0.1 IU/mouse, i.c.v.) significantly increased plasma ACTH levels (p < 0.05) and tended to increase beta-endorphin levels (p = 0.052) in acetic acid-treated mice, whereas no change in PGE2 level was observed (p > 0.1). These results suggest that the anti-aversive effects of SCT may be mediated, at least in part, by the activation of ACTH.

Acetates↗
PubMed1994

An epidemiological study of leprosy infection by serology and polymerase chain reaction.

A population-based study has been carried out in two adjacent villages in a highly leprosy-endemic area of South Sulawesi, Indonesia. The prevalence of clinical leprosy was 10.0 per 1000 inhabitants. A total of 1015 serum samples and 1228 nasal swab specimens were collected. IgM antibodies in blood to phenolic glycolipid-I (PGL-I) of Mycobacterium leprae were demonstrated by the gelatin particle agglutination test (MLPA) and by indirect ELISA (IgM-PGL). IgG antibodies to PGL-I (IgG-PGL) and lipoarabinomannan-B (IgG-LAM) were measured by indirect ELISA. The presence of M. leprae in nasal swab specimens was established by a polymerase chain reaction (PCR). The seropositivity rates in the population were 32% for MLPA, 30.8% for IgM-PGL, 6.7% for IgG-PGL, and 11.6% for IgG-LAM. Seropositivity rates for MLPA and IgM-PGL were highest in the younger age groups. There was no difference in seropositivity in any of the tests between household contacts of leprosy patients and noncontacts. The seropositivity rates in the MLPA and IgM-PGL were not randomly distributed among all households. The presence of M. leprae by PCR was demonstrated in 7.8% of the nasal swab specimens. No correlation was found between the results of the PCR and serology. This study indicates that M. leprae is widespread in the population, and that in endemic areas many individuals carry M. leprae in their nasal cavities without having obvious symptoms of leprosy.

Adolescent↗
PubMed1994

A multimedia system for infection control education.

We developed a computer system for infection control education utilizing multimedia including video presentation. To evaluate the efficiency of the system, trial sessions were held among dental students attending final year of clinical courses. According to our results of comparison between pre and post assessment tests among these students, we concluded that this system has a great potential and advantages for achieving certain level of knowledge of infection control in limited amount of time.

Computer-Assisted Instruction↗
PubMed1994

Pregnancy complicated by liver dysfunction: possible pathogenesis of vasospasm.

BACKGROUND: Acute fatty liver of pregnancy, the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP), and severe preeclampsia form a disease spectrum. We report a case that showed a vasospastic phenomenon supported angiographically and hematologically. CASE: A 31-year-old Japanese woman presented at 37 weeks gestation with a 1-week history of nausea, vomiting and general fatigue. She underwent cesarean delivery for fetal distress. Liver dysfunction and disseminated intravascular coagulopathy were detected. The celiac angiogram showed vascular narrowing and irregularity of the vascular wall. Serum endothelin and the ratio of thromboxane B2 to 6-keto-prostaglandin F1 alpha were increased at the same time. The patient experienced rapid resolution of symptoms and laboratory abnormalities in the immediate postoperative period. CONCLUSION: A pregnancy complicated by liver dysfunction showed a vasospastic phenomenon, which may suggest the presence of a vasospastic syndrome.

Adult↗
PubMed1993

Induced resistance and susceptibility to cerebral ischemia in gerbil hippocampal neurons by prolonged but mild hypoperfusion.

Brief periods of non-lethal cerebral ischemia can induce resistance against subsequent lethal ischemia. In this study, asymptomatic gerbils after unilateral carotid artery ligation were subjected to 5 min of forebrain ischemia. The prolonged but mild hypoperfusion, by carotid occlusion, induced susceptibility at 1 day and tolerance at 30 days to lethal ischemia in the hippocampal neurons. The neuroprotective effect correlated well with induction of heat shock protein 72 in the hippocampal neurons. These results suggested that neuronal cells possess a cellular response to sublethal hypoperfusion and can survive forthcoming ischemic stress.

Animals↗
PubMed1993

Effects of an NK1 receptor antagonist, FK888, on constriction and plasma extravasation induced in guinea pig airway by neurokinins and capsaicin.

The effects of FK888, an NK1 receptor antagonist, on airway constriction and airway plasma extravasation induced by neurokinins and capsaicin were investigated in guinea pigs. FK888 inhibited substance P (10(-8) M)- and neurokinin A (10(-9) M)-induced contraction of isolated guinea pig trachea, with IC50 values of 3.2 x 10(-8) and 4.2 x 10(-6) M, respectively. FK888 given i.v. inhibited substance P (13.5 micrograms kg-1)-induced airway constriction with an ED50 value of 0.40 mg kg-1 but did not inhibit neurokinin A (1.1 micrograms kg-1)- and capsaicin (3.1 micrograms kg-1)-induced airway constriction at a dose of 1 mg kg-1. On the other hand, FK888 given i.v. inhibited airway plasma extravasation induced by substance P (1.3 micrograms kg-1), neurokinin A (11 micrograms kg-1) and capsaicin (100 micrograms kg-1) with equal potency and ED50 values of 0.011, 0.0063 and 0.019 mg kg-1, respectively. When FK888 was given locally (into the airway directly) inhibitory activities were more potent than following i.v. administration. In this case FK888 inhibited substance P-, neurokinin A- and capsaicin-induced airway constriction with ED50 values of 3.2, 190 and 550 micrograms kg-1, respectively, suggesting that an about 100 times higher dose is required to inhibit neurokinin A- and capsaicin-induced airway constriction than substance P-induced constriction. FK888 given orally was also effective in substance P-, neurokinin A- and capsaicin-induced airway plasma extravasation with ED50 values of 4.2, 5.9 and 9.5 mg kg-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Applications of biotinylated V3 loop peptides of human immunodeficiency virus type 1 to flow cytometric analyses and affinity chromatographic techniques.

A principal neutralizing determinant of human immunodeficiency virus type 1 (HIV-1) lies within the V3 loop of gp120, the external major envelope glycoprotein. V3 loop peptides derived from two HIV-1 strains, HTLV-III BH-10 (V3-BH10) and LAVELI (V3-ELI), were synthesized and biotinylated. The binding of both biotinylated V3-BH10 and V3-ELI to the surfaces of MOLT-4 clone 8 cells was demonstrated by flow cytometric analyses. Both the peptides (more than 2 microM) bound to the cells (2 x 10(5) in a dose-dependent manner. The binding of biotinylated V3-BH10 was specifically inhibited by a neutralizing monoclonal antibody (0.5 beta). The binding of both of the biotinylated V3 loop peptides was enhanced by the addition of unlabeled V3-BH10. In addition, the peptides were employed as ligands on affinity columns. A major V3 loop binding protein (V3BP) was purified from the membrane soluble fraction of MOLT-4 cells by successive application to two different V3 loop columns. V3BP consisted of two major polypeptides (32 and 33 kDa). The SDS-PAGE profile of V3BP did not change under non-reducing conditions, but only a single band was observed after analysis on native PAGE. The major peak of the eluate as determined by size exclusion chromatography was broad and the estimated relative molecular mass was much larger than 33 kDa, suggesting that V3BP comprises several subunits. Taken together, we confirmed that the V3 loop peptides are useful in the characterization of V3BP(s) of which they are conformational ligands.

Amino Acid Sequence↗
PubMed1993

Expression of GLUT4 glucose transporter mRNA and protein in skeletal muscle and adipose tissue from rats in late pregnancy.

We investigated the influence of pregnancy on the expression of insulin-regulated glucose transporter (GLUT4) mRNA and protein in skeletal muscle and adipose tissue. GLUT4 mRNA expression in quadriceps muscle from control and pregnant rats was similar in the fasted and fed states. When the level of expression was determined as the immunoreactive GLUT4 content per gram of tissue, the relative GLUT4 protein content of red quadriceps from pregnant rats was significantly higher than that for control rats in both the fed and fasted states. GLUT4 protein expression in white quadriceps from pregnant rats was significantly increased in the fed state compared to control rats, but there was no significant difference in the fasted state. In adipose tissue, the relative GLUT4 protein content was significantly lower in pregnant rats than control rats in the fasted state, but there was no significant decrease in the fed state. Although the expression of GLUT4 protein showed these variations in late pregnancy, there was no significant difference of GLUT4 mRNA expression between control and pregnant rats. These findings suggest that GLUT4 kinetics may differ between late pregnancy and the normal state, and these changes may be related to insulin resistance in pregnancy.

Adipose Tissue↗
PubMed1993

Mother-to-child transmission of human T-lymphotropic virus type I (HTLV-I): an extended follow-up study on children between 18 and 22-24 years old in Okinawa, Japan.

The significant difference observed between the seroprevalence of HTLV-I in adults and in children is as yet unexplained. To evaluate a hypothetical explanation of the existence of seroconversion cases of "seronegative carriers" for this phenomenon, 21 of 55 children who had been born to seropositive mothers and who remained seronegative until the age of 18 years were further followed up at the ages of 22 and/or 24 years. None of the 21 seronegative children born to seropositive mothers seroconverted, either at 22 years or at 24 years. In addition, the polymerase-chain-reaction (PCR) technique could not prove the existence of the HTLV-I provirus genome in peripheral mononuclear cells (PBMC) of 10 of these children. Our results fail to prove the possibility of viral latency of HTLV-I in mother-to-child transmission. Therefore, the hypothetical seroconversion of "seronegative carriers" after adulthood cannot be an explanation.

Adolescent↗