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Biomedical subjects

T Hashimoto

Publications and source records attributed to T Hashimoto.

At least 73 records · Page 4Linked to original sources
PubMed1992

Receptor-coupled shortening of alpha-toxin-permeabilized single smooth muscle cells from the guinea-pig stomach.

1. Isolated single smooth muscle cells from the fundus of the guinea-pig stomach were permeabilized by use of Staphylococcus aureus alpha-toxin. Receptor-coupled shortening of individual cells was monitored under phase contrast microscopy. 2. Most of the isolated cells responded to 0.6 microM Ca2+, but not to 0.3 microM Ca2+, with a resulting maximal shortening to approximately 65% of the resting cell length. The contractile activity of these permeabilized cells lasted for several hours and repeated shortening was readily achieved after washing out. 3. Addition of acetylcholine (ACh) at a maximal concentration (10 microM) resulted in a marked decrease in the concentration of Ca2+ required to trigger a threshold response from 0.6 microM to 0.2 microM, and 1 mM guanosine 5'-diphosphate (GDP) blocked this decrease. Moreover, treatment with 100 microM guanosine 5'-triphosphate (GTP) mimicked the action of ACh. 4. Addition of 100 microM inositol 1,4,5-trisphosphate (InsP3) with 0.2 microM Ca2+ did not cause cell shortening, whereas 10 microM ACh with 0.2 microM Ca2+ did, suggesting that InsP3-induced Ca2+ release is not involved in ACh-operated cell shortening. 5. The present study demonstrates an alpha-toxin-permeabilized single smooth muscle cell preparation which retains its receptor function and also provides an insight into mechanisms leading to augmentation of Ca2+ sensitivity by stimulation of muscarinic receptors or GTP-binding proteins.

Acetylcholine↗
PubMed1992

Magnetic resonance imaging of the brain structures in the posterior fossa in retarded autistic children.

Midsagittal magnetic resonance images of the brains of retarded autistic children were compared to those of non-autistic mental retardation patients and controls. We found that the whole brain stem and particularly two of its components (the midbrain and medulla oblongata) were significantly smaller in retarded autistic children and mental retardation cases than in control children. The pons area was significantly smaller in mental retardation cases as compared to control children but did not differ between autistic and control children. Moreover, there was no difference in the brain stem between retarded autistic children and mental retardation cases. We also noted no difference in the cerebellar vermis area among retarded autistic children, mental retardation cases and control children. The ratio of the midbrain to posterior fossa area was significantly smaller only in autistic patients. Although the significance of these results is unknown, further examination of autistic children with a normal IQ is necessary.

Autistic Disorder↗
PubMed1992

Estimation of blood flow in the carotid artery and intraorbital ophthalmic artery by color pulse Doppler ultrasonography.

Blood flow velocity was estimated in the orbital part of the ophthalmic artery and in the carotid artery, by way of pulse Doppler ultrasonography. The equipment was a Toshiba SSA-270A machine. The material comprised 12 glaucoma patients (20 eyes, all with open angles) under satisfactory IOP control, mean age 52 years, and 28 healthy controls (mean age 40 years; 54 eyes). Systolic flow velocities of 46 cm/sec and 103 cm/sec, in the ophthalmic and carotid artery respectively, were found in the normal subjects. With mean values of 42 and 116 cm/sec in the glaucoma group there was no significant difference between groups. The same applied to the average flow velocities. A considerable interindividual variation was found.

Adult↗
PubMed1992

Identification of Pseudomonas aeruginosa by using a disk of phenanthroline and 9-chloro-9-[4-(diethylamino)phenyl]-9,10-dihydro-10-phenylacridine hydrochloride and by cell agglutination testing with monoclonal antibodies.

To establish a simple identification procedure for Pseudomonas aeruginosa, we developed a disk consisting of phenanthroline and 9-chloro-9-[4-(diethylamino)phenyl]-9,10-dihydro-10- phenylacridine hydrochloride (PC disk). Nine of 248 P. aeruginosa isolates and all other oxidase-positive gram-negative isolates (143 isolates) had clear inhibition zones around the PC disk. Of these nine P. aeruginosa isolates, seven produced a blue, blue-green, or green pigment on Mueller-Hinton agar after 24 h of incubation. The sensitivity and specificity of the PC disk susceptibility test in combination with pyocyanin production were 99 and 100%, respectively. Ten P. aeruginosa isolates showed no agglutination reactions with monoclonal antibodies against P. aeruginosa (96% sensitivity and 100% specificity).

Acridines↗
PubMed1992

Detection of serum Candida antigens by enzyme-linked immunosorbent assay and a latex agglutination test with anti-Candida albicans and anti-Candida krusei antibodies.

Serum samples from 197 patients with and without candidiasis were assayed for Candida albicans mannan and Candida krusei mannan by an enzyme-linked immunosorbent assay (ELISA) and a latex agglutination test (LA) and for D-arabinitol by the enzymatic fluorometric method. Of the 43 patients positive for C. albicans mannan (> or = 0.2 ng/ml), 34 were infected with C. albicans and 9 were infected with Candida tropicalis. C. krusei mannan (> or = 0.3 ng/ml) was detected in 10 patients infected with Candida parapsilosis, 2 patients infected with Candida guilliermondii, and 1 patient infected with C. krusei. With both anti-C. albicans antibodies and anti-C. krusei antibodies, the sensitivities of ELISA and LA for detection of invasive candidiasis (58 patients) were 74 and 38%, respectively. No false-positive reactions were observed by the ELISA or the LA. The sensitivity and specificity of the D-arabinitol/creatinine ratio (> or = 1.5 mumol/mg) to invasive candidiasis were 50 and 91%, respectively. The ELISA with antibodies against both C. albicans and C. krusei may be useful in diagnosing invasive candidiasis caused by medically important Candida strains excluding Candida glabrata.

Adult↗
PubMed1992

Enhanced growth-dependent expression of TGF beta 1 and hsp70 genes in aortic smooth muscle cells from spontaneously hypertensive rats.

Enhanced proliferation of vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) as compared with Wistar-Kyoto rats (WKY) persists in long-term culture and is characterized by an accelerated entry of these cells into the synthetic S phase of the cell cycle and a higher specific growth rate, particularly evident at high cell density. In the present study, we investigated by Northern blot experiments the expression of genes putatively involved in the regulation of VSMC growth. One of them is the transforming growth factor beta 1 gene (TGF beta 1), a bifunctional modulator of cell growth whose action is dependent on cell density. The accumulation of TGF beta 1 mRNA was enhanced in growing SHR cells at every density studied as early as 24 h after inoculation with a further increase at later times. Protooncogenes c-fos and c-myc, which have been implicated in G1/S phase transition, have also been investigated in VSMC by Northern blot analysis. At low cell density, calf serum stimulated c-fos and c-myc mRNA expression was comparable in WKY and SHR cells whereas at high cell density, c-fos induction was higher in VSMC from SHR. SHR VSMC respond more to mitogenic stimulation and to environmental (e.g., heat) stress, particularly when growing near saturation density. hsp70 constitutes a gene family responsive to environmental stimuli (heat) and to mitogenic stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Comparative study on the behavioral and EEG changes induced by diazepam, buspirone and a novel anxioselective anxiolytic, DN-2327, in the cat.

Behavioral and EEG effects of 2-(7-chloro-1,8-naphthyridin-2-yl)-3-[(1,4)-dioxa-8-(azas piro-[4.5]dec-8- yl)carbonylmethyl]isoindolin-1-one (DN-2327; 1, 5 and 20 mg/kg p.o.) were compared to those of diazepam (0.2 and 1 mg/kg p.o.) and buspirone (1 and 5 mg/kg p.o.) in freely moving cats. DN-2327 did not affect motor coordination or the relative percentages of the three sleep-wakefulness stages. Diazepam (1 mg/kg) increased wakefulness and non-REM sleep, and buspirone (5 mg/kg) also increased wakefulness and decreased REM sleep. In addition, diazepam (1 mg/kg) caused severe motor disturbance, but buspirone did not. The cortical EEG power density spectra during wakefulness were changed almost dose-dependently by DN-2327 (decreased: 2-7.75 Hz; increased: 20-49.75 Hz), and dose-dependently by diazepam (decreased: 2-7.75 Hz; increased 13-49.75 Hz) and buspirone (decreased: 4-9.75 and 13-19.75 Hz). The effect of DN-2327 on the cortical EEG varied with the sleep-wakefulness stage. The power of the 4- to 7.75-Hz frequency (theta) band of the hippocampal EEG during wakefulness was decreased by diazepam and buspirone but not by DN-2327, while the peak frequency of its spectra was decreased only by diazepam. On the other hand, during non-REM sleep, DN-2327 decreased the power of the theta band as did diazepam. These results indicate that the behavioral and EEG effects of DN-2327 differ completely from those of buspirone and considerably from those of diazepam and that the EEG effect of DN-2327 varies with the sleep-wakefulness stage.

Animals↗
PubMed1992

Induction of a BrdU-enhanceable fragile site-like lesion and sister chromatid exchanges at 11q23.1 in EBV-transformed lymphoblastoid cell lines.

We examined the expression of a fragile site-like lesion and induction of sister chromatid exchanges (SCEs) at 11q23.1 in EBV-transformed lymphoblastoid cell lines derived from carriers of distamycin A-inducible fragile sites and ataxia telangiectasia patients. The fragile site-like lesion at 11q23.1 was found to be BrdU-enhanceable in all cell lines examined, and the expression frequencies increased linearly with the rates of BrdU substitution in replicated DNA. In addition, an increased frequency of SCEs was observed at 11q23.1 on the expressed chromosome. Thus, the BrdU-enhanceable fragile site-like lesion at 11q23.1 is a "hot spot" for the formation of SCEs, as has been reported for other rare and common fragile sites.

Bromodeoxyuridine↗
PubMed1992

Increased Na-K transport in glomerular mesangial cell membrane from spontaneously hypertensive rats.

To investigate the differences in the Na-K transport of the mesangial cell (MC) membrane in hypertension versus normotension, the activity of the Na-K pump and the passive cation permeability were measured in serially passaged cultured MC obtained from both spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. When Na-K pump was active, Na-K pump activity, described as ouabain-sensitive 86Rb uptake, was significantly greater in the cultured MC from SHR than WKY rats. The outward Na-K cotransport, described as the washout rate constant of bumetanide-sensitive 86Rb washout, was also greater in SHR MC than in WKY rat MC. When Na-K pump was inhibited by 1 mM ouabain, overall intracellular Na uptake was significantly greater in SHR MC. A greater 5-(N,N-hexamethylene)amiloride-sensitive Na uptake in SHR MC accounted for this difference. There was no difference in the intracellular concentration of Na and K in the cultured MC from the 2 strains when Na-K pump was active. It is concluded that there is an increased activity of Na-K pump in the cultured MC from SHR, and that this abnormality may be innate to SHR cells. It is also suggested that an increase in Na-K cotransport and Na-H antiport may explain this difference, and that these abnormalities observed in the SHR kidney may be involved in the pathogenesis of hypertension in this model.

Animals↗
PubMed1992

Serum prostatic acid phosphatase, gamma-seminoprotein and prostatic specific antigen in hemodialysis patients.

Serum concentrations of prostatic acid phosphatase (PAP), gamma-seminoprotein (gamma-Sm) and prostatic specific antigen (PSA) were measured in 31 hemodialysis patients without clinical signs of malignant disease. PAP, gamma-Sm and PSA levels in serum were not significantly different between control and hemodialysis groups. A significant reduction in these tumor markers was not found after dialysis treatment. This indicates that the measurement of PAP, gamma-Sm and PSA in serum is useful for the detection of prostatic cancer in patients undergoing hemodialysis.

Acid Phosphatase↗
PubMed1992

Wilson's disease treatment by triethylene tetramine dihydrochloride (trientine, 2HCl): long-term observations.

Wilson's disease is an autosomal recessive disorder characterized by an accumulation of a toxic amount of copper in the body. Triethylene tetramine dihydrochloride (trientine, 2HCl) is a new chelating agent that may be effective in the removal of excess copper but long-term efficacy has not yet been investigated. Here we report the use of trientine over more than 8 years in 2 patients with Wilson's disease who could not tolerate D-penicillamine. We found no significant side effect, except a decreased serum iron concentration without clinical symptoms of anemia. In annual examinations at a steady state, the serum copper levels remained below 20 micrograms/100 ml. The 24-hour urinary copper excretion was less than that found using D-penicillamine, while the basal copper excretion, after 5 days abstinence from trientine, was maintained below 100 micrograms/day. Both hepatic and neurological manifestations except bulbar symptoms were recovered without any initial deterioration.

Adolescent↗
PubMed1992

Identification of three mutant alleles of the gene for mitochondrial acetoacetyl-coenzyme A thiolase. A complete analysis of two generations of a family with 3-ketothiolase deficiency.

3-Ketothiolase deficiency (3KTD) stems from a deficiency of mitochondrial acetoacetyl-coenzyme A thiolase (T2). We analyzed the molecular basis of 3KTD in two generations of a family. A boy (patient 2, GK04), his father (patient 1, GK05), his mother, and his brother were studied; three mutant alleles of T2 gene were identified. Patient 1 is a compound heterozygote: one allele has a point mutation of G to A at position 547 on his T2 cDNA, causing Gly150 to Arg substitution of the mature T2 subunit, and the other allele has GT to TT transition at the 5' splice site of intron 8, causing exon 8's skipping of the T2 cDNA. Patient 2 is also a compound heterozygote: one allele inherited from his mother has AG to CG transition at the 3' splice site of intron 10, causing exon 11's skipping of the T2 cDNA, and the other allele derived from patient 1 has the G to A mutation (Gly to Arg). The brother of patient 2 is an obligatory carrier with the mutant allele causing the exon 8 skipping. This report seems to be the first complete molecular definition of 3KTD at the gene level.

Acetyl-CoA C-Acetyltransferase↗
PubMed1992

Evaluation of a new systolic time interval, the Q-V peak: effects of heart rate, contractile state, and loading conditions in dogs.

The authors investigated the effects of alterations in heart rate, contractility, and loading conditions on a newly defined systolic time interval, the Q-V peak, in 46 anesthetized dogs. The Q-V peak was measured as the time from the beginning of the electrocardiographic Q wave to the moment at which the blood flow rate reached its peak in the ascending aorta as determined with an electromagnetic flowmeter. The Q-V peak did not change significantly as the heart rate was varied by atrial pacing between 70 and 110 beats/minute. The Q-V peak shortened when the contractility was augmented with dobutamine (p = 0.0001) and was prolonged when it was depressed with propranolol (p = 0.0001). However, the Q-V peak did not change significantly when the left ventricular end-diastolic pressure or the mean aortic blood pressure was increased to 130% or decreased to 70% of the baseline values. These findings suggest that one may also evaluate left ventricular performance by measuring the time to systole, which the authors define as the Q-V peak.

Animals↗
PubMed1992

Circadian rhythm in patients with hydranencephaly.

Circadian rhythm and sleep were studied in three hydranencephalic infants who were diagnosed on the basis of computed tomographic and/or magnetic resonance imaging scans and electrophysiologic findings. In all three cases, although the active sleep cycle was preserved, quiet sleep decreased and indeterminate sleep increased. The sleep-circadian rhythm was disturbed in all three cases. The hormone secretion rhythm was studied in two cases (cases 1 and 3). In both cases, cortisol secretion showed two or three peaks during the day. In one case (case 3), growth hormone secretion did not show sleep enhancement. Prolactin secretion showed an increase during sleep in both cases. The circadian rhythm of body temperature appeared at 6 months of age and disappeared after 1 year of age in case 1. Case 2 did not show a circadian rhythm of body temperature, but case 3 did at 2 years 6 months of age. However, it was thought that the circadian rhythm of body temperature in case 3 was a false one due to severe opisthotonus. Thus, it is suggested that the development of the circadian rhythm may require the rostral brain structure more than the midbrain and that there may be multiple oscillators in humans.

Brain Stem↗
PubMed1992

Different intracellular localization of peroxisomal proteins in fibroblasts from patients with aberrant peroxisome assembly.

We investigated intracellular localization of peroxisomal proteins in fibroblasts from patients with Zellweger syndrome and neonatal adrenoleukodystrophy in whom peroxisomes were morphologically deficient or severely decreased. Indirect immunofluorescence staining revealed that catalase was mainly detected in the cytosol of fibroblasts from these patients, but a small amount of catalase was detected in granular pattern in a small percentage of cells. Double immunofluorescence staining revealed that catalase-containing particles in these patients also contained acyl-CoA oxidase and nonspecific lipid transfer protein. However, a 70 kD integral membrane protein and 3-ketoacyl-CoA thiolase were detected in all cells in granular pattern. Subcellular fractionation using digitonin after cell labeling revealed that a small amount of acyl-CoA oxidase and about half of thiolase in the precursor form were detected in the particulate fraction. These data suggest that the mechanisms of the transport and processing of catalase, acyl-CoA oxidase and nonspecific lipid transfer protein are different from those of the 70 kD integral membrane protein and 3-ketoacyl-CoA thiolase.

Acyl-CoA Oxidase↗