Biomedical subjects

M Takeda

Publications and source records attributed to M Takeda.

At least 613 records · Page 34Linked to original sources

PubMed1993

Value of urinary endothelin-1 in patients with primary vesicoureteral reflux.

By using a radioimmunoassay specific for endothelin-1 (ET-1), we measured urinary excretion of ET-1-like immunoreactivity (LI) in 63 spot urine samples of 48 patients with primary vesicoureteral reflux (VUR). And also, urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin (beta-2-MG), microalbumin (Alb) and creatinine (Cr) were measured. There was no significant correlation in any of the pairs ET-1 and NAG, ET-1 and beta 2-MG, and ET-1 and Alb. Comparing the grade of reflux according to the International Classification with urinary ET-1, urinary ET-1/Cr levels in patients with grade 2, 3 and 4 VUR were higher than normal, and the ratio of more than normal urinary ET-1/Cr increased in proportion to the grade of reflux, but it conversely decreased in grade 5. In conclusion, urinary ET-1 may be an indicator of renal tubular injury in patients with primary VUR, and its meaning may be different from conventional urinary parameters.

Acetylglucosaminidase↗

PubMed1993

Purification of a trypsin-type protease from human umbilical vein endothelial cells which is highly sensitive to the Kunitz inhibitor domain peptide of Alzheimer's disease amyloid protein precursor.

A trypsin-type protease was purified to enzymatic homogeneity from human umbilical vein endothelial cells by sequential affinity chromatographies. The enzyme specifically hydrolyzed dibasic substrates with leucine at the P3 positions, but scarcely hydrolyzed the other substrates tested. The enzyme was strongly inhibited by the Kunitz inhibitor domain peptide of Alzheimer's disease amyloid protein precursor (Ki value, 0.35 nM) and by the microbial inhibitors leupeptin and anti-pain. These results, together with a previous finding of a significant increase in the expression of Alzheimer's amyloid protein precursors (beta APPs) with the Kunitz inhibitor domain in Alzheimer's disease, suggest that the activity of the trypsin-type protease is suppressed by an increase of beta APPs with inhibitor activity in Alzheimer's disease, resulting in aberrant intracellular protein catabolism including degradation of beta APPs and beta-protein deposition.

Amino Acid Sequence↗

PubMed1993

Evaluation of upper urinary tract dynamics by diuresis renography in patients receiving urinary reservoir operation. Comparison of full and empty reservoir.

Upper urinary tract dynamics was evaluated using diuresis renography during full and empty reservoir in 14 patients (11 men, 3 women, 13-70 years old) with intestinal urinary reservoir or intestinal bladder augmentation. Types of operation were Mainz pouch urinary diversion 5, Mainz neobladder to urethra, 5, Kock pouch urinary diversion 2, and Mainz bladder augmentation 2. Diuresis renography was performed using 99mTc-DTPA and furosemide during full and empty reservoir, and several parameters (Tmax, T75, T50, GFR) in addition to the patterns of renogram were evaluated. In the normal control, none of the parameters of the diuresis renogram with full bladder differed from those with empty bladder. In 5 of 14 patients, abnormal waves on cystometry (CMG) were found, and in 4 of these 5 patients, the patterns of diuresis renogram of full reservoir were worse than those of empty reservoir. However, the patterns of diuresis renogram of full reservoir were not different from those of empty reservoir in 9 patients without abnormal waves on CMG. In conclusion, renal injury may easily occur in patients with intestinal reservoir and abnormal waves on CMG.

Adolescent↗

PubMed1993

Successful fibrinolytic therapy using tissue plasminogen activator in acute renal failure due to acute thrombosis of bilateral renal arteries.

A 46-year-old housewife with regurgitation of mitral valve developed acute renal failure due to acute thrombosis of bilateral renal arteries after cardiac catheterization. A regional fibrinolytic therapy using transarterial infusion of tissue plasminogen activator (t-PA) was performed at 8 h after the onset, and was successful. She could be taken off hemodialysis 2 weeks after the fibrinolytic therapy, and could be successfully operated on with mitral valve replacement 7 months after that. Three years after mitral valve replacement, her serum creatinine was 148 mumol/l. This is the longest follow-up case after regional transarterial fibrinolysis of acute thrombosis of renal artery using t-PA, and this therapy is a safe and good one for acute thrombosis of renal artery.

Acute Disease↗

PubMed1993

Neuropathologic changes in the gerbil brain after chronic hypoperfusion.

BACKGROUND AND PURPOSE: An animal model has been developed to elucidate the pathological changes in brain cytoskeletal proteins during chronic hypoperfusion. METHODS: Newly designed coiled clips were placed around both carotid arteries of Mongolian gerbils (n = 10) to cause stenosis without occlusion. Those gerbils showing impaired learning ability by the passive avoidance paradigm were killed for neuropathologic study after 12 weeks. RESULTS: The brains showed ventricular dilatation, cortical atrophy, and rarefaction of the white matter. Immunoreactivity to anti-microtubule-associated protein 2 antibody in the cerebral cortex and the hippocampus was diminished, indicating dendritic changes of neurons. In the thalamic axonal regions, staining with anti-neurofilament 200K protein antibody was increased, suggesting increased amounts of neurofilament proteins or increased phosphorylation of the protein. Increased immunoreactivity to anti-glial fibrillary acidic protein antibody was observed in a wedge-shaped configuration, corresponding to the border zone of perfusion by small vessels. CONCLUSIONS: These findings suggest that changes in the cytoskeletal proteins in dendrites, axons, and glial cells may cause neuronal death under conditions of chronic cerebral hypoperfusion.

Animals↗

PubMed1993

Cellular heterogeneity of ammonium ion transport across the basolateral membrane of the hamster medullary thick ascending limb of Henle's loop.

The epithelia of the medullary thick ascending limb (MAL) consists of two cell types, high (HBC) and low basolateral conductance (LBC) cell, depending on the K+ conductance of the basolateral membrane. The NH4+ conductance distinct from the K+ conductance has been suggested to exist in the proximal tubule, MAL cell, and Xenopus oocyte. The present study was designed to examine whether there is a conductive NH4+ transport system distinct from K+ conductance in two different cell types of the hamster MAL perfused in vitro. The basolateral membrane voltage (VB) was measured by impaling cells with conventional microelectrodes. Addition of NH4+ to the bath depolarized VB in a dose-dependent manner in both cell types. The response was maintained in the absence of HCO3-. When the VB deflection elicited upon 50 mM KCl or NH4Cl in the bath (delta VBK+ or delta VBNH4+) were compared, delta VBNH4+ was almost the same as delta VBK+ in the HBC cell, whereas the former was greater than the latter in the LBC. In the HBC cell, 10 mM Ba2+ in the bath equally suppressed both delta VBK+ and delta VBNH4+, whereas in the LBC cell it suppressed delta VBK+ with a small effect on delta VBNH4+, indicating that NH4+ is transported via a pathway distinct from Ba(2+)-sensitive K+ conductance. The VB deflection by NH4+ was unaffected by addition of 0.1 mM ouabain or 10 microM 5-nitro-2-(3-phenylpropylamino)-benzoate (a Cl- channel blocker) to the bath, excluding the contribution of the Na+, K+ pump or Cl- channel. An abrupt reduction of Na+ in the bath from 200 to 20 mM did not cause any changes in VB, suggesting that a nonselective cation channel may not account for the NH4+ transport. Amiloride at 10 microM inhibited delta VBNH4+ with a higher efficacy in the LBC cell. We conclude that a rheogenic NH4+ transport system independent from the K+ conductance exists in the basolateral membrane of the LBC cell of the hamster MAL, and may play some roles in the regulation of NH4+ transport.

Ammonia↗

PubMed1993

Selective beta 1-adrenoceptor agonist activity of denopamine and its derivatives in dogs.

Cardiovascular effects of intravenously administered denopamine and its derivatives were investigated in anesthetized dogs and their positive inotropic and hypotensive effects were compared. Structure-activity relationships were examined by modifying the methoxy group in ring B and the hydroxy group in ring A in structure II, a ring-fissioned product of trimetoquinol. Almost all test compounds demonstrated positive inotropic and chronotropic effects as well as hypotensive effects which were mediated by beta-adrenoceptors. With modification of the methoxy group in ring B, only 3,4-dimethoxy, 2,3,4-trimethoxy and 3,4,5-trimethoxy derivatives exhibited beta 1-adrenoceptor selectivity. The 3,4-dimethoxy derivative showed the most potent positive inotropic effect and the highest selectivity to beta 1-adrenoceptor. By structural modification of the hydroxyl group in ring A of the 3,4-dimethoxy derivatives, the potency of positive inotropic effect was affected, while beta 1-adrenoceptor selectivity of the derivatives with 3,5-dihydroxy, 3- and 4-monohydroxy groups were essentially maintained. Among beta 1-adrenoceptor selective compounds, the dose ratios between intravenous and intraduodenal administrations of catechol derivatives like isoproterenol were higher than those of non-catechol derivatives. The 4-monohydroxy derivative (racemic denopamine) exhibited the smallest dose ratio with a long-lasting action. Thus, we could identify selective beta 1-adrenoceptor agonists by the structural modification of a selective beta 2-adrenoceptor agonist, trimetoquinol. In this group of compounds, beta-hydroxy moiety was suggested to be requisite to potent beta-adrenoceptor stimulating action and 3,4-dimethoxyphenethyl structure was important for manifestation of beta 1-adrenoceptor selectivity.

Adrenergic beta-Agonists↗

PubMed1993

Antisecretory effects of a novel and long-lasting histamine H2-receptor antagonist, YM-14471, in rats and dogs.

We investigated some properties of YM-14471 (2-2(-[2-(diaminomethyleneamino)thiazol-4-yl]methylthio)ethy l-5-[3- (diethylamino)propyl]-6-methyl-pyrimidine-4-one trihydrochloride), a new H2-receptor antagonist, in comparison with those of famotidine, cimetidine and omeprazole. In guinea pig atria, famotidine and cimetidine produced a competitive dose-dependent displacement of histamine-induced tachycardia. In contrast, low concentrations of YM-14471 showed competitive inhibition of tachycardia, whereas high concentrations were irreversible or slowly dissociable. In pylorus-ligated rats, intravenous YM-14471, famotidine and cimetidine dose-dependently inhibited basal gastric secretion with ED50 values of 0.04, 0.43 and 31.2 mg/kg, respectively. ED50 values for oral YM-14471, famotidine, cimetidine and omeprazole were 0.81, 0.42, 28.9 and 7.7 mg/kg when given at 1 hr before ligation, and 5.7, 26.7, 1639.5 and 18.6 mg/kg at 5 hr before ligation. In anesthetized dogs, intravenous YM-14471, famotidine, cimetidine and omeprazole also dose-dependently inhibited histamine (160 micrograms/kg.hr)-induced acid secretion with ED50 values of 13.7, 8.7, 333.3 and 65.3 micrograms/kg, respectively. In Heidenhain pouch dogs, YM-14471 inhibited histamine (40 micrograms/kg.hr)-induced acid secretion by both intravenous (0.02 mg/kg) and oral administration (0.3 mg/kg). Moreover, the inhibitory effect of YM-14471 was more prolonged than those of famotidine and cimetidine by either route, and it was as long as that of omeprazole dosed orally. These results suggest that YM-14471 is an irreversible or slowly dissociable H2-receptor antagonist, and has long antisecretory effect.

Animals↗

PubMed1993

Histamine H2-receptor plays only a minor role in histamine-induced wheal response in the squirrel monkey and guinea pig.

We examined the contribution of the histamine H2-receptor to the histamine-induced wheal response in squirrel monkeys and guinea pigs. Intradermal injection of histamine, 2-pyridylethylamine (a selective H1-agonist), and dimaprit (a selective H2-agonist) dose-dependently induced the wheal response in squirrel monkeys and guinea pigs, although the reaction to dimaprit was much weaker than that to the other agonists. Chlorpheniramine dose-dependently depressed the wheal response in squirrel monkeys and guinea pigs at doses of 0.03-1 mg/kg and 0.03-3 mg/kg, p.o., respectively. However, famotidine, ranitidine and cimetidine had no effect at doses up to 30, 100 and 300 mg/kg, p.o. in guinea pigs and up to 1, 10 and 400 mg/kg, p.o. in squirrel monkeys, respectively. Cimetidine (3-300 mg/kg, p.o.) dose-dependently potentiated the inhibitory effects of chlorpheniramine (0.1 mg/kg, p.o.) in guinea pigs, but had no effects in squirrel monkeys. Famotidine and ranitidine did not alter the response to chlorpheniramine in either animal. These results suggest that the histamine H2-receptor plays only a minor role in the histamine-induced wheal response in squirrel monkeys and guinea pigs.

Animals↗

PubMed1993

Transmissibility of the D variant of encephalomyocarditis virus (EMC-D) in mice.

Transmissibility of the D variant of encephalomyocarditis virus (EMC-D) was examined. Eight-week-old ICR:CD-1 male mice inoculated with 10(5) plaque forming units (PFU)/animal of EMC-D intranasally, orally or intraperitoneally showed marked viraemia and prominent pancreatic lesions at 2 days after inoculation (2 DAI), and excreted virus in faeces from 2 to 8 DAI (virus titre: 10(3)-10(5) PFU/g). Only a small proportion of control mice housed with EMC-D-inoculated mice for 10 days developed viraemia and pancreatic lesions.

Animals↗

PubMed1993

The disturbance of water-maze task performance in mice with EMC-D virus infection.

The present study was performed to examine the influence of EMC-D virus on water-maze task performance in DBA/2 mice inoculated with 10(3) PFU/ml and BALB/c mice inoculated with 10(5) PFU/ml of EMC-D virus. In both strains, the latency to accomplish the task was shortened during successive 8 days of testing. However, the shortening of latency in the inoculated group was significantly smaller than that in the control group. Pathological studies showed that in both studies St. pyramidale hippocampi was commonly degenerated, but the degeneration of the spinal cord was shown only in DBA/2 mice. Therefore, the disturbance of water-maze task performance in mice infected with EMC-D virus might be partially due to the dysfunction of memory for working process or cognition of orientation other than underlying decreased ability in locomotion.

Animals↗

PubMed1993

Concentration of gadolinium-diethylene triamine pentaacetic acid in human kidney--study on proper time for dynamic magnetic resonance imaging of the human kidney on low and high magnetic fields.

Although Gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) has been used as a contrast material in magnetic resonance imaging, it is known that contrast enhancement effect disappears if the concentration of Gd-DPTA increases beyond some levels. In this study, to evaluate the proper pulse sequences for dynamic magnetic resonance imaging (MRI) in the human kidney, the concentration of Gd-DTPA was quantitatively measured by inductively coupled plasma (ICP) emission spectrometry in human biological samples after administration of Gd-DTPA, and the signal intensity of MRI is the solutions of several concentrations of Gd-DTPA was measured. The results were; 1. In using a low magnetic field apparatus, signal intensity linearly correlated with the concentration of Gd-DTPA between 0 and 2.0 mumol/g under saturation recovery sequences (flip angle was 60 degrees or 90 degrees). Using a high magnetic field apparatus, signal intensity linearly correlated with the concentration of Gd-DTPA between 0 and 2.0 or 3.0 mumol/g under spin echo or gradient-echo sequences. 2. Gd-DTPA concentration of the renal cortex ranged from 0.132 to 0.152 mumol/g tissue at 5 min after intravenous injection of Gd-DTPA 0.05 mmol/kg body weight in 7 patients with adrenal tumor or renal cell cancer, and 1 patient with both urinary bladder cancer and prostatic cancer. Seven of them showed normal renal function and the other had renal insufficiency (GFR 25 ml/min/1.48 m2). Gd-DTPA concentrations of renal medulla and renal cell cancer tissue were 0.123 and 0.108 mumol/g tissue, respectively, at 5 min after intravenous injection of Gd-DTPA 0.05 mmol/kg body weight. These results suggest that the signal intensity of renal cortex, renal medulla, and renal cell cancer tissue may linearly correlate with Gd-DTPA concentration of tissues at 5 min after intravenous injection of Gd-DTPA 0.5 mmol/kg body weight.

Adult↗

PubMed1993

Brachytherapy for non-metastatic squamous cell carcinoma of the buccal mucosa. An analysis of forty-five cases treated with permanent implants.

An analysis has been undertaken of 45 patients with non-metastatic squamous cell carcinoma of the buccal mucosa treated by permanent 198Au or 222Rn implants and in most cases supplementary external irradiation. Eight patients had T1, 30 had T2, and 7 T3 disease. Of the lesions 21 were located in the buccal mucosal surface, 14 in the retromolar region, and 10 in the bucco-alveolar sulci. Seven of the 45 (16%) died of the disease and the actuarial 5-year survival rate was 81%. No obvious differences were noted in survival rate between different stages of the disease or between different subsites of the primary lesion. There were 6 local recurrences occurring from 3 to 33 months after treatment, and only one of these was salvageable by further radiation therapy. Neck node metastasis occurred in 11 cases from 2 to 34 months after treatment, and 8 of these cases responded successfully to a radical neck dissection or radiotherapy.

Adult↗

PubMed1993

[Multimodal evoked potentials in patients with dementia].

The event-related potential (ERP), somatosensory evoked potential (SEP) and visual evoked potential (VEP) were studied in 15 patients with Alzheimer's disease (AD), 16 patients with Parkinson's disease with dementia (PD), 7 patients with Binswanger's disease (BD) and 15 normal controls. ERP was recorded during auditory discriminative tasks. SEP evoked by median nerve stimulation was recorded from the second cervical vertebra and contralateral primary somatosensory cortex with a midfrontal reference. VEP was recorded during pattern reversal stimulation. All three groups with dementia showed significant prolongation of the N200 and P300 latencies of ERP compared with the normal controls. In addition, patients with AD showed significant prolongation of the P200 latency. There was a significant correlation between the P300 latency of ERP and MMSE scores in AD patients. Patients with AD and PD showed significant prolongation of the interpeak latency between N13 and P40 (N13-P40) and N20-P40 of SEP compared with the normal controls. Patients with BD showed significant prolongation of the N13-N20, N13-N33, N13-P40 and N20-P40. These results suggest that there is impairment of the ascending somatosensory pathway in patients with dementia. Patients with PD showed significant prolongation of the P100 latency of VEP compared with normal controls. There was a significant correlation between the N200 latency of ERP and the P100 latency of VEP in PD patients. The VEP results suggest that dysfunction in the central visual system plays a role in abnormal pattern VEP in PD. In conclusion, the present results show that these three dementing diseases have different electrophysiological features, which may be related to the underlying pathogenic mechanisms. Additionally, the measurement of multimodal evoked potentials may be helpful in the differential diagnosis of patients with dementia.

Aged↗

PubMed1993

[Event-related potential and visual evoked potential in patients with Parkinson's disease].

The event-related potential (ERP) and visual evoked potential (VEP) were recorded in 28 patients with Parkinson's disease (PD) and 28 normal subjects. Nine of the PD patients had dementia and 19 did not. Dementia was evaluated according to the criteria for dementia assigned by the DSM III-R, and mental faculties were estimated using the Mini-Mental State Examination (MMSE). ERP was recorded during auditory discriminative tasks. The latencies of N100, P200, N200 and P300 from the Pz region were measured. VEP was recorded during pattern reversal stimulation. The latency of P100 was measured for each eye stimulated. PD patients with dementia showed significant prolongation of the N200 and P300 latencies of ERP and of the P100 latency of VEP compared with the values in normal subjects and in PD patients without dementia. There was a significant correlation between the N200 latency of ERP and the P100 latency of VEP in PD patients with dementia. The findings indicate that the N200 and P300 latencies of ERP are related to cognitive information processing and also suggest that dysfunction in the central visual system plays a role in abnormal pattern VEP in patients with dementia. Furthermore, the disturbance of early sensory processing in response to visual stimuli may roughly parallel the impairment of cognitive information processing in terms of ERP in PD patients with dementia.

Aged↗

PubMed1993

[Two cases of hepatic encephalopathy associated with a high-intensity area in the basal ganglia on T1-weighted MR images].

The authors report two cases of hepatic encephalopathy with chronic hepatic failure. Case 1 was a 78-year-old woman with liver cirrhosis, admitted because of general fatigue and loss of appetite. Her electroencephalogram showed frequent slow waves in the theta range with intermittent triphasic waves T1-weighted MR images showed increased signal intensity in the globus pallidus and the putamen. Case 2 was a 71-year-old woman with chronic hepatitis, admitted because of depression. Her electroencephalogram showed frequent slow wave activities in the theta-delta range with intermittent trisphasic waves. Her serum ammonia level was 84 micrograms/dl (normal 12-54 micrograms/dl). T1-weighted MR images showed increased signal intensity in the globus pallidus, the putamen and the hypothalamus. On the basis of these findings, both patients were diagnosed as having hepatic encephalopathy, although disturbance of consciousness was not obvious. The observed MR image abnormalities might be due to the metabolic and pathological changes of chronic hepatic failure. Such MRI findings may be useful for the diagnosis of hepatic encephalopathy.

Aged↗

PubMed1993

[Treatment of urinary tract anomalies detected by prenatal ultrasonography].

Twelve pediatric patients with antenatal diagnosed urinary tract anomalies from 1988 to 1992 in Niigata University Hospital were clinically examined. 1: All patients were diagnosed by ultrasonography. Eleven cases did not have any abnormal pregnancy and other had oligohydramnious. 2: Postnatal surgical treatments were performed in 11 cases, but antenatal therapy was not performed in any case. 3: Temporary percutaneous nephrostomy (PNS) were carried out on 7 kidneys in 6 cases during infantile period seems to be effective in preserving function of congenital obstructed kidneys.

Female↗

PubMed1993

[Experimental reconstruction of the urinary bladder using atelocollagen sponge].

An experimental reconstruction of the urinary bladder using specially designed bovine cross linked atelocollagen sponge was performed after partial cystectomy in 12 male rabbits. Bladder reconstruction with hybrid type biomaterials using both atelocollage sponge and cultured autologous cells were performed in 5 rabbits (the 1st group). The autologous cells were collected from the mucosa and muscular layer of the urinary bladder and were seeded on the atelocollagen sponge before reconstruction. Reconstruction using atelocollagen sponge without autologous cells were performed in the other 7 rabbits (the 2nd group). In 9 of these 12 rabbits, atelocollagen sponge was successfully implanted in the native urinary bladder. Histopathological findings revealed that seeded autologous cells and growth of surrounding host cells could be seen similarly in the atelocollagen sponge but these could not be differentiated by these could not be differentiated by routine histopathological techniques. In conclusion, these results showed a possibility of construction of artificial urinary tract using both atelocollagen sponge and autologous cells.

Animals↗