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Biomedical subjects

M Ohno

Publications and source records attributed to M Ohno.

At least 145 records · Page 8Linked to original sources

Enhanced N-methyl-D-aspartate function reverses working memory failure induced by blockade of group I metabotropic glutamate receptors in the rat hippocampus.

Intrahippocampal administration of (R,S)-1-aminoindan-1, 5-dicarboxylic acid (AIDA), a potent and selective antagonist of the group I metabotropic glutamate receptor (mGluR), at doses of 0.32-3.2 microg/side dose-dependently increased the number of errors (attempts to pass through two incorrect panels of the three panel-gates at four choice points) in the working memory task with a three-panel runway setup. The increase in working memory errors induced by intrahippocampal 3.2 microg/side AIDA was significantly reduced by concurrent infusion of 10 microg/side D-cycloserine, a partial agonist at the glycine binding site on the N-methyl-D-aspartate (NMDA) receptor/channel complex. These results suggest that positive modulation of the NMDA receptor/ channel through activation of the glycine site can compensate for deficiency of hippocampal group I mGluR-mediated neurotransmission involved in working memory function.

Animals↗

Novel guide catheter for left coronary intervention via a right upper limb approach.

We designed a novel guide catheter specifically for interventions to the left coronary artery via a right upper limb approach. The catheter has a novel first loop design which utilizes the angle between the right subclavian and innominate arteries for support. The first loop introduces the catheter into the correct position and generates powerful and coaxial back-up power. We report successful implantation of Palmaz-Schatz stents in five cases using this 6 Fr. catheter.

Aged↗

The application of radio-opaque markers prior to ileostomy in an infant with chronic intestinal pseudo-obstruction: report of a case.

We report the case of a 6-month-old boy who developed chronic intestinal pseudo-obstruction soon after birth. A rectal biopsy demonstrated immaturity of the neuronal cells in the enteral ganglion. His clinical course was stressful, with remission and exacerbation despite conservative treatment with daily bowel irrigation, prokinetic agents, and parenteral nutrition. Since the infant developed serious enterocolitis associated with the increased severity of his bowel obstruction, and no substantial gain in body weight was observed, a loop-ileostomy was performed based on X-ray findings with radio-opaque markers, which were employed to evaluate the whole gut transit time. The radio-opaque markers proved extremely useful for determining which loop of the ileum should be utilized for the ileostomy.

Barium Sulfate↗

Manual reduction with the index finger for infantile intussusception. A modification of Hutchinson's maneuver.

Manual reduction with the index finger (modified Hutchinson's maneuver) enabling simple and safe manual reduction of infantile intussusception is described. The procedure was used in four patients, two boys and two girls, ranging in age from 2 to 15 months, as greater than normal compression was necessary and/or serosal splitting occurred during conventional reduction. The technique is as follows: in addition to the proximal bowel compression with Hutchinson's maneuver, the surgeon inserts his index finger into the intussusceptum via its neck. The finger enables the surgeon to sound a wider space between the intussusceptum and intussuscipiens, which is most likely to be responsive to bowel compression. Although the intussusceptions in the four patients were categorized as ileo-ileo-colic (three cases) and ileo-ileal (one case) types, this manual reduction technique was successful in all cases, no bowel rupture occurred, and hospitalization was no longer than with the conventional procedure. We conclude that this modified Hutchinson's maneuver may contribute to successful surgical reduction of infantile intussusception.

Female↗

Colonic obstruction induced by plasma cell granuloma of the transverse colon: report of a case.

Plasma cell granuloma is mainly composed of reactive plasma cell proliferation, the origin of which is uncertain. Immunohistochemically, the plasma cells are characterized by a polyclonal nature, and must be distinguished from plasmacytoma which displays a monoclonal nature. This tumor is most commonly found in the lung and bronchus, but has rarely been described in the alimentary tract. We report herein a case of plasma cell granuloma of the transverse colon. A 71-year-old woman was admitted for lower abdominal pain with severe inflammation and anemia. Ultrasound examination and computed tomography showed an abdominal tumor. Barium enema revealed the tumor to be located in the transverse colon causing colonic obstruction. The resected tumor was spherical and mainly spread in the submucosal layer. Microscopically, the tumor consisted of severe infiltration of mature plasma cells within the spindle-shaped myofibroblasts. Immunohistochemical studies showed IgA, IgG, IgM, and kappa and lambda chains, and revealed a polyclonal nature of the plasma cells. Thus, a pathological diagnosis of plasma cell granuloma affecting the transverse colon was made. To the best of our knowledge, this is the first report of successful surgical resection of plasma cell granuloma of the colon.

Aged↗

Retrotransposable CR1-like elements in crotalinae snake genomes.

A part of the 3'-flanking region of BP-II gene, which is one of Trimeresurus flavoviridis venom gland phospholopase A2 (PLA2) isozyme genes, has a region homologous to avian chicken repeat 1 (CR1)-element. In the present study, ten CR1-like elements were further identified in T. gramineus venom gland PLA2 isozyme genes, T. flavoviridis PLA2 inhibitor (PLI) genes, and T. flavoviridis and T. gramineus TATA-box binding protein (TBP) genes. Southern blot analysis using a probe for CR1 showed that Crotalinae snake genomes contain a number of CR1-like elements.

Amino Acid Sequence↗

Molecular evolution of snake toxins: is the functional diversity of snake toxins associated with a mechanism of accelerated evolution?

Recent studies revealed that animal toxins with unrelated biological functions often possess a similar architecture. To tentatively understand the evolutionary mechanisms that may govern this principle of functional prodigality associated with a structural economy, two complementary approaches were considered. One of them consisted of investigating the rates of mutations that occur in cDNAs and/or genes that encode a variety of toxins with the same fold. This approach was largely adopted with phospholipases A2 from Viperidae and to a lesser extent with three-fingered toxins from Elapidae and Hydrophiidae. Another approach consisted of investigating how a given fold can accommodate distinct functional topographies. Thus, a number of topologies by which three-fingered toxins exert distinct functions were investigated either by making chemical modifications and/or mutational analyses or by studying the three-dimensional structure of toxin-target complexes. This review shows that, although the two approaches are different, they commonly indicate that most if not all the surface of a snake toxin fold undergoes natural engineering, which may be associated with an accelerated rate of evolution. The biochemical process by which this phenomenon occurs remains unknown.

Amino Acid Sequence↗

Relations of nm23 expression to clinicopathologic variables and proliferative activity of gastric cancer lesions.

Relationships of nm23 expression and 12 clinicopathologic variables and proliferative activity of cancer cells were examined in 55 gastric cancer patients to clarify the effects of nm23 expression on the factors and activity in gastric cancer. Expression of nm23 was determined by immunohistochemically stained sections using a monoclonal antibody, nm23H-1. Proliferative activity was immunohistochemically evaluated by proliferating cell nuclear antigen (PCNA) labeling index (LI) using a monoclonal antibody PC10. Expression of nm23 was found in 24 lesions (positive group) but not in 31 lesions (negative group). With regard to clinicopathologic variables, a significant (p < 0.05) difference between the positive and negative groups was found in 1 of the 12 factors, depth of cancer invasion. PCNA LI (48.9 +/- 11.6%) of the former group was significantly (p < 0.05) higher than that (40.3 +/- 12.6%) ot the latter, although multiple regression analysis showed that nm23 expression was not one of the most influencing variables for PCNA LI. The results may suggest that expression of nm23 in gastric cancer lesions is correlated to tumor progression and/or proliferation rather than suppression of metastasis.

Aged↗

Hypertension in Leigh syndrome--a case report.

A female patient, who was diagnosed with Leigh syndrome at 15 months of age, developed fulminating severe hypertension and died at 8 years of age. Hypertension has not been reported as an important clinical symptom in Leigh syndrome. Laboratory findings indicated that it was not associated with endocrinopathic diseases such as pheochromocytoma and aldosteronism, or renal diseases. Brain MRI scan showed symmetrical lesions in the basal ganglia and medulla oblongata including the nucleus tractus solitarius. This nucleus is known to play an important role in maintaining blood pressure. Since the medulla oblongata is a vulnerable site, potential development of hypertension should be taken into consideration when managing Leigh syndrome.

3-Iodobenzylguanidine↗

Tyrosine phosphorylation of platelet derived growth factor beta receptors in coronary artery lesions: implications for vascular remodelling after directional coronary atherectomy and unstable angina pectoris.

BACKGROUND: Growth factors such as platelet derived growth factor (PDGF) have been postulated to be important mediators of neointimal proliferation observed in atherosclerotic plaques and restenotic lesions following coronary interventions. Binding of PDGF to its receptor results in intrinsic receptor tyrosine kinase activation and subsequent cellular migration, proliferation, and vascular contraction. AIMS: To investigate whether the concentration of PDGF beta receptor tyrosine phosphorylation obtained from directional coronary atherectomy (DCA) samples correlate with atherosclerotic plaque burden, the ability of diseased vessels to remodel, coronary risk factors, and clinical events. METHODS: DCA samples from 59 patients and 15 non-atherosclerotic left internal thoracic arteries (LITA) were analysed for PDGF beta receptor tyrosine phosphorylation content by receptor immunoprecipitation and antiphosphotyrosine western blot. The amount of PDGF beta receptor phosphorylation was analysed in relation to angiographic follow up data and clinical variables. RESULTS: PDGF beta receptor tyrosine phosphorylation in the 59 DCA samples was greater than in the 15 non-atherosclerotic LITA (mean (SD) 0.84 (0.67) v 0.17 (0.08) over a control standard, p < 0.0001). As evaluated by stepwise regression analysis, incorporation of both PDGF beta receptor tyrosine phosphorylation and immediate gain correlated strongly (adjusted r2 = 0.579) with late loss, although PDGF beta receptor tyramine phosphorylation alone correlated poorly with late loss. Multivariate regression analysis of coronary risk factors and clinical events revealed unstable angina as the most significant correlate of PDGF beta receptor tyrosine phosphorylation (F value 20.009, p < 0.0001). CONCLUSIONS: PDGF beta receptor tyrosine phosphorylation in atherosclerotic lesions is increased compared with non-atherosclerotic arterial tissues. The association of PDGF beta receptor tyrosine phosphorylation with immediate gain strongly correlates with vascular remodelling. PDGF beta receptor tyrosine phosphorylation correlates with unstable angina pectoris.

Angina, Unstable↗

Crossroads of the effects of cyclophosphamide pulse therapy for lupus nephritis--experience of 11 cases.

In this study time for initial assessment of monthly intravenous cyclophosphamide (CP) pulse therapy is discussed for a better outcome with less complications. Eleven patients with lupus nephritis (LN) resistant to conventional therapy (serum creatinine level < or = 2.7 mg/dl) were given 500 mg/m2 of CP 7-9 times with an interval of one month. Urinary protein (Up) decreased in all patients after 3 courses of CP pulse therapy and kept similar levels thereafter. In one group of patients (n = 7), Up decreased to < 2 g/day after 3 courses, while in the other group (n = 4), it did not decrease to < 4 g/day. Creatinine clearance increased by 0-100% in the former group, while it decreased by 5-20% in the latter group after 6-9 courses. Renal function of the patients with insufficient response after 3 courses tended to show no further improvement or worsened thereafter, although Up decreased during CP pulse therapy. A relatively small dose of CP (500 mg/m2) pulse therapy was useful in most LN patients regardless of the renal histology and it was thought important to assess its effects after 3 courses for a prediction of the clinical course. Modification of the protocol at that time might be necessary in regard to dose or interval of CP administration especially for patients with insufficient outcome.

Adult↗

Comparison of antiplatelet effects of two nitric oxide-donating agents, FR146801 and FK409.

In the present study, we examined the antiplatelet effects of the two nitric oxide (NO)-donating agents, (+/-)-N-[(E)-4-ethyl-3-[(Z)-hydroxyimino]-6-methyl-5-nitro-3-he ptenyl]-3-pyridinecarboxamide (FR146801). a more stable analog of FK409 ((+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide ), and FK409 in in vitro and in vivo experiments. FR146801 and FK409 inhibited ADP- and collagen-induced platelet aggregation in human and rat platelet-rich plasma in a concentration-dependent manner, however, the inhibitory effect of FR146801 was weaker than that of FK409. In human washed platelets (WP), FR146801 and FK409 inhibited collagen-induced platelet aggregation in a concentration-dependent manner. The inhibitory effects of FR146801 and FK409 on platelet aggregation were closely reflected by the increase in the intraplatelet cGMP level. This intensely suggests that the antiplatelet activities of FR146801 and FK409 are due to NO-released from them. In the rat extracorporeal shunt model, FR146801 inhibited thrombus formation dose-dependently and its inhibition was significant at 10 mg/kg, p.o. FK409 suppressed thrombus formation significantly at 1.0 mg/kg, p.o., at which it induced significant hypotension, whereas FR146801 did not show any significant hypotensive effect even at 10 mg/kg, p.o. These results suggest that FR146801 has desirable antiplatelet effects both in vitro and in vivo and that its in vivo antiplatelet effect is more selective than its hypotensive effect, while FK409 does not show a selective antiplatelet effect in vivo.

Animals↗

[Participation of apoptosis in renal amyloidosis].

Renal amyloidosis shows symptoms of renal dysfunction due to the deposition of amyloid protein in the kidney. Recently, it was reported that apoptosis plays an important role in the pathogenesis of type-2 diabetes mellitus and Alzheimer's disease of which amyloid deposition is seen in the tissue. We investigated whether or not apoptosis and related factors are observed in renal amyloidosis. In situ nick end labeling (TUNEL) was performed in seven autopsied renal tissues with primary and secondary amyloidosis and 10 autopsied renal tissues without renal disease as the control. The number of TUNEL-positive cells was significantly increased in both the glomeruli and tubulus of the kidney with amyloidosis than in the control. Electron microscopic analysis was performed on one biopsied renal tissue with amyloidosis and six biopsied renal tissues with minor abnormalities as the control. Typical apoptotic cells were observed only in the former. Bax product, an inducer of apoptosis, and Bcl-2 protein, an inhibitor of apoptosis, were examined immunohistochemically in the seven autopsied renal tissues with amyloidosis and 10 autopsied control tissues. Bax was overexpressed in the tubulus and glomeruli of subjects with renal amyloidosis, compared to the normal controls. However, Bcl-2 protein was not detected in the glomeruli in any of the subjects examined. These results indicate that apoptotic cells are increased in number in renal amyloidosis and Bax overexpression may play an important role in this increase.

Aged↗

Recent aspects of gestational trophoblastic disease in Japan.

The regional registration in 11 prefectures and one area covering 34% of total Japanese population started in 1974, increasing gradually to 21 prefectures and one area in 1993 covering 48.5% of total Japanese populations, by the Japan Trophoblastic Disease Committee under the auspices of Japan Society of Obstetrics and Gynecology. The results showed marked decreasing trend in incidence of molar pregnancy and choriocarcinoma in Japan. The most frequent antecedent pregnancies of choriocarcinoma has shifted from molar pregnancy in 1974 to term pregnancy in 1993. The Choriocarcinoma Risk Score Table that is in use and of practical significance, differentiating choriocarcinoma from invasive or metastatic mole by reference to simple 8 clinical items with the probability of more than 90% when compared with the histological diagnoses, is also presented.

Choriocarcinoma↗

Concurrent blockade of beta-adrenergic and muscarinic receptors suppresses synergistically long-term potentiation of population spikes in the rat hippocampal CA1 region.

The muscarinic acetylcholine receptor antagonist scopolamine, but not the beta-adrenoceptor antagonist propranolol or atenolol, suppressed tetanus-induced long-term potentiation (LTP) of population spikes in the rat hippocampal CA1 region. When scopolamine was coapplied with propranolol or atenolol, a synergistic effect in preventing LTP generation was observed. On the other hand, the coapplication of scopolamine and atenolol failed to affect tetanus-induced LTP of field EPSP. These findings suggest that cooperative mechanisms via muscarinic and beta-adrenergic receptor activation might contribute to LTP induction in terms of the EPSP-spike potentiation, i.e., an increase in the excitability of hippocampal CA1 pyramidal cells after tetanic stimulation, but are independent of the tetanus-evoked potentiation of a synaptic component.

Acetylcholine↗