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Biomedical subjects

T Taira

Publications and source records attributed to T Taira.

At least 109 records · Page 6Linked to original sources
PubMed1995

Variation in the primary structure of waxy proteins (granule-bound starch synthase) in diploid cereals.

The molecular weights of waxy proteins, by SDS-PAGE, and the N-terminal amino acid sequences of mature protein and of V8 protease-induced fragments were determined in diploid cereals. The homology of the primary structure was relatively high among cereals examined here, and there appeared to be a common sequence, V-F-V-G-A-E-M-A, in the vicinity of the N terminus. Based on the amino acid sequences, these cereals could be divided into two groups, including corn and rice in one and diploid wheat, four Aegilops species, rye, and barley in the other. In diploid wheat and Aegilops species there were substitutions of amino acids in the primary structure. Variations of this sort suggest that the primary structure of waxy proteins would provide clues to the phylogenetic relations in the wheat group.

Amino Acid Sequence↗
PubMed1994

The use of microsurgical planing to treat traumatic tattoos.

A traumatic tattoo results from an abrasion in which dirt, carbon, tar, asphalt, or other particles have become embedded beneath the superficial layer of the dermis. These embedded particles are difficult to remove completely. Under a microscope, rectangular epidermal and upper dermal grids including these pigments are made, and each section of the grid is removed. The microsurgical planing technique has the following advantages: it saves the maximum possible amount of normal skin, and the particles are completely removed. Twenty patients have been treated with this technique and have obtained excellent results.

Accidents, Traffic↗
PubMed1994

A novel DNA replication origin identified in the human heat shock protein 70 gene promoter.

A general and sensitive method for the mapping of initiation sites of DNA replication in vivo, developed by Vassilev and Johnson, has revealed replication origins in the region of simian virus 40 ori, in the regions upstream from the human c-myc gene and downstream from the Chinese hamster dihydrofolate reductase gene, and in the enhancer region of the mouse immunoglobulin heavy-chain gene. Here we report that the region containing the promoter of the human heat shock protein 70 (hsp70) gene was identified as a DNA replication origin in HeLa cells by this method. Several segments of the region were cloned into pUC19 and examined for autonomously replicating sequence (ARS) activity. The plasmids carrying the segments replicated episomally and semiconservatively when transfected into HeLa cells. The segments of ARS activity contained the sequences previously identified as binding sequences for a c-myc protein complex (T. Taira, Y. Negishi, F. Kihara, S. M. M. Iguchi-Ariga, and H. Ariga, Biochem. Biophys. Acta 1130:166-174, 1992). Mutations introduced within the c-myc protein complex binding sequences abolished the ARS activity. Moreover, the ARS plasmids stably replicated at episomal state for a long time in established cell lines. The results suggest that the promoter region of the human hsp70 gene plays a role in DNA replication as well as in transcription.

Base Sequence↗
PubMed1994

Extracellular alkaline transients mediated by glutamate receptors in the rat hippocampal slice are not due to a proton conductance.

1. The ionic mechanism of extracellular alkaline transients mediated by alpha-amino-3-hydroxy-5-methylisoxazolate-4-propionic acid (AMPA) receptor channels was studied in the rat hippocampal slice (area CA1) by means of H(+)-, Ca(2+)- and Na(+)-selective microelectrodes. 2. Alkaline transients mediated by selective synaptic activation of AMPA receptors were coupled to a transient fall in extracellular Ca2+ ([Ca2+]o). 3. Removal of [Ca2+]o blocked the alkaline transient evoked by microinjection of AMPA, but had little effect on the simultaneous tetrodotoxin-resistant fall in extracellular Na+ ([Na+]o). 4. Alkaline transients evoked by microinjection of gamma-aminobutyric acid (GABA) were not affected by removal of [Ca2+]o. GABA had no effect on [Na+]o. 5. The present results indicate that activity-induced glutamatergic alkaline transients in the hippocampal slice are due to an influx of Ca2+, and not to a conductive movement of H+ ions across glutamate-gated cation channels.

Acid-Base Equilibrium↗
PubMed1994

An image-guided stereotactic system for neurosurgical operations.

A new simulation system utilizing digital images (CT/MRI/SPECT) and an ultrasound/laser navigation system has been developed for image-guided surgery. Preoperative CT/MRI imaging does not always indicate the actual location of the lesion during intracranial operation, because the lesion may be displaced or distorted by operative procedures or CSF flowout. The authors developed an image integration system including an intraoperative ultrasonogram, which provides accurate information not only on the location of the deep-seated lesions but also surrounding anatomical structures during operation. The rationale of the system is to coordinate the three-dimensional axes of each image with the aid of a stereotactic subframe. Our simulation system has two ways. One simulation system works on a SUN workstation. At the preoperative simulation study: the entry point on the brain surface and the access route to the lesion are decided on from the three-dimensional CT/MRI images on the computer display. Then the configuration of the lesion from the operative view is displayed as an expected ultrasound image by reconstructing the CT and/or SPECT image. Another simulation system (HyperCAS) works on the HyperCard of a MacIntosh. The target point, the entry point and the trajectory are decided on and the three-dimensional location of these points is measured from serial CT images on the LCD display. At the time of operation, stereotactic craniotomy is performed using the laser navigator. The extent of the lesion at every depth in the surgical process is predicted from these images, and the access route to the lesion is easily corrected with the intraoperative ultrasound navigator.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Simulation↗
PubMed1994

Immunochemical study of epidermal growth factor in rats with mercuric chloride-induced acute renal failure.

Urine contains high concentrations of epidermal growth factor (EGF), and EGF is a potent growth promoter for proximal tubular cells. In the present study, urinary and whole-kidney EGF levels were investigated in rats with mercuric chloride (HgCl2)-induced acute renal failure (ARF) using a specific radioimmunoassay for rat EGF to clarify changes in EGF after toxic injury. Male Wistar rats were given HgCl2 (2 mg/kg, subcutaneously) or saline. Serum urea nitrogen and creatinine levels were measured for 4 days after toxin administration. Forty-eight hours after toxic injury, urinary immunoreactive EGF levels in HgCl2-treated rats decreased significantly compared with control rats (1.62 +/- 0.15 versus 3.78 +/- 0.21 ng/mg creatinine; p < 0.01). Urinary immunoreactive EGF was at its lowest level 96 h after toxic injury (0.64 +/- 0.06 ng/mg creatinine; p < 0.001). Twenty-four hours after toxic injury, renal immunoreactive EGF levels increased significantly compared with control rats (22.04 +/- 2.12 versus 4.84 +/- 0.70 ng/g wet weight tissue; p < 0.001), and the increase persisted for as long as 48 h (13.36 +/- 1.61 ng/g wet weight tissue; p < 0.05). In summary, urinary immunoreactive EGF levels decreased and renal EGF levels increased in rats with HgCl2-induced ARF. These findings suggest that there is an impairment in the excretion of EGF in rats with HgCl2-induced ARF and that local paracrine production of EGF continues in ARF.

Acute Kidney Injury↗
PubMed1994

[Intracavernous internal carotid artery aneurysm associated with persistent trigeminal artery variant: case report].

The authors report a case of an intracavernous internal carotid artery aneurysm associated with a persistent trigeminal artery variant (PTAV). A 47-year-old-woman developed a subarachnoid hemorrhage due to the rupture of aneurysm and underwent direct clipping operation. PTAV is basically an anomalous anastomosis between the internal carotid artery and the anterior inferior cerebellar artery. In this patient, the PTAV originated from the C4 portion of the right internal carotid artery and distributed in the territory of the hemispheric branch of the posterior inferior cerebellar artery. There have been only three reported cases of the internal carotid artery aneurysms arising from the crotch of PTAV. It is also unusual that rupture of such a small aneurysm in the cavernous sinus causes subarachnoid hemorrhage. Embryological development of PTAV and possible mechanism of subarachnoid hemorrhage from the intracavernous aneurysm are discussed.

Aneurysm, Ruptured↗
PubMed1993

Early postnatal treatment with muscimol transiently alters brain GABAA receptors and open-field behavior in rat.

The long-term effects of treatment with muscimol, a GABAA agonist, and with ethanol, also shown to have a GABAergic profile of action, on subsequent behavior and on the binding parameters of GABAA receptors were studied in Wistar rats. Rats were given two daily injections of muscimol (0.1 mg/kg M1 group of 0.2 mg/kg M2 group) or ethanol (1.5 g/kg) between the 1st and 21st postnatal days, with saline-treated animals serving as controls. At the age of one month, the activity of the M2 rats was decreased in the open-field arena. At the age of four months, ethanol-treated rats consumed less 10% ethanol solution in a free choice situation. No changes were seen in the elevated plus-maze test. Maximal GABA stimulation of [3H]flunitrazepam binding was decreased in the cerebellum and hippocampus in M2 rats at the age of one month but not four months. A significant positive correlation was found in all rats between maximal GABA-stimulated [3H]flunitrazepam binding in the cerebellum and ambulation in the open-field arena at the age of one month. Ethanol intake correlated negatively with maximal GABA stimulation of [3H]flunitrazepam binding in the cerebral cortex. None of the treatments affected the cerebellar binding of an imidazobenzodiazepine, [3H]Ro 15-4513. There was an age-dependent decline in the efficacy and potency (EC50) of the GABA enhancement of [3H]flunitrazepam binding in the cerebellum in all treatment groups. Basal binding of [3H]flunitrazepam to hippocampal and cerebellar membranes as well as binding of [3H]Ro 15-4513 to cerebellar membranes was also decreased as a function of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1993

Massive spinal cord necrosis associated with adult T-cell leukaemia caused by Aspergillus.

A man with adult T-cell leukaemia (ATL) underwent massive spinal cord necrosis caused by Aspergillus infection. Leukopenia due to anti-cancer chemotherapy resulted in pulmonary Aspergillus infection. The aspergilloma was reduced in size by anti-fungal chemotherapy, but paraplegia occurred. At autopsy, the pulmonary aspergilloma was encapsulated and showed no contiguous extension of the infection to the epidural or subdural spaces or spinal cord. However, at the T5 level of the spinal cord, there was marked necrosis with haemorrhage caused by Aspergillus infection, but without leukaemic cell infiltration of the spinal cord. Dichotomously branching Aspergillus hyphae filled the blood vessels of the T5 level of the spinal cord.

Aspergillosis↗
PubMed1993

Inhibition of intestinal motility and reversal of postlaparotomy ileus by selective alpha 2-adrenergic drugs in the rat.

BACKGROUND: The effects of selective alpha-agonist medetomidine and alpha 2-antagonist atipamezole on gastrointestinal motility were studied. METHODS: The passage of intragastrically administered Evans blue in the small bowel of unanesthetized rats was followed, and the stomachs were weighted after killing the rats. RESULTS: Subcutaneous medetomidine, 0.01-0.1 mg/kg, was found to delay small intestinal transit but not gastric emptying, with a maximal effect seen at 0.03 mg/kg. Atipamezole fully reversed the effect of 0.1 mg/kg of medetomidine with a dose of 2.5 mg/kg. Atipamezole alone did not affect small intestinal transit. Subcutaneous morphine, 6 mg/kg, delayed gastric emptying and small intestinal transit, whereas intraperitoneal morphine only delayed gastric emptying. Subcutaneous atipamezole, 0.06 mg/kg, was partially able to reverse the delayed intestinal transit but did not inhibit morphine-induced gastric retention. Subcutaneous atipamezole, 0.06 mg/kg, reversed laparotomy-induced ileus completely. CONCLUSIONS: Atipamezole may provide a useful treatment for postlaparotomy ileus.

Adrenergic alpha-Agonists↗
PubMed1993

Urinary epidermal growth factor levels in patients with acute renal failure.

To investigate the importance of epidermal growth factor (EGF) in patients with renal dysfunction, urinary human EGF (hEGF) levels were determined by radioimmunoassay in 16 patients with acute renal failure (ARF) and in 12 healthy controls. Seven patients with chronic renal failure also were studied. Urinary hEGF levels, corrected for urine creatinine concentrations, were significantly decreased in patients with ARF in the acute phase compared with normal control subjects (0.98 +/- 0.20 v 13.74 +/- 1.18 ng/mg creatinine, P < 0.001), and subsequently increased during the recovery phase (6.10 +/- 0.73 ng/mg creatinine, P < 0.001 v acute phase). A significant positive correlation existed between urinary hEGF levels and creatinine clearance in patients with ARF (r = 0.66, P < 0.001). Serum hEGF levels also were significantly lower in patients with ARF compared with normal control subjects (0.10 +/- 0.01 v 0.30 +/- 0.03 ng/mL, P < 0.001). No significant correlation was found between hEGF concentrations in serum and urine. In conclusion, measurement of urinary hEGF may be useful in the diagnosis of ARF and for following the recovery of the kidney after severe tubular injury.

Acute Kidney Injury↗
PubMed1993

Hybrid lethal systems in the Drosophila melanogaster species complex. I. The maternal hybrid rescue (mhr) gene of Drosophila simulans.

Hybrid females from Drosophila simulans females x Drosophila melanogaster males die as embryos while hybrid males from the reciprocal cross die as late larvae. The other two classes are sterile adults. Letting C, X, and Y designate egg cytoplasm, X, and Y chromosomes, respectively, and subscripts m and s stand for melanogaster and simulans, CmXmYs males are lethal in the larval stage and are rescued by the previously reported genes, Lhr (Lethal hybrid rescue) in simulans or Hmr (Hybrid male rescue) in melanogaster. We report here another rescue gene located on the second chromosome of simulans, mhr (maternal hybrid rescue) that, when present in the mother, rescues CsXmXs females from embryonic lethality. It has been postulated that the hybrids not carrying the Xs like CmXmYs males are larval lethal and that the hybrids carrying both the Cs and the Xm like CsXmXs females are embryonic lethal. According to these postulates CsXmYs males (obtained by mating attached-X simulans females to melanogaster males) should be doubly lethal, at both embryo and larval stages. When both rescuing genes are present, Hmr in the father and mhr in the mother, males of this genotype are fully viable, as predicted.

Animals↗
PubMed1993

Facial injuries from falling: age-dependent characteristics.

A retrospective analysis was undertaken of 108 patients with facial injuries from falling who presented at the Plastic Surgery Unit of the Toyo-oka Public Hospital from 1988 to 1990. Facial injuries from falling were common in little children, in those < 6 years of age comprising 45.4% of injuries. Age-dependent characteristic injury sites were found (i.e., in those < 2 years old, the forehead; in small children, the chin; in students, the lip; and in older persons, the cheek); this disparity can be explained by the mechanism of injury. The injury pattern also depended on age, varying activities, and tissue strength. In children of < 6 years of age, small lacerations on the forehead or chin were most common, but even conservative treatment could achieve good results. On the other hand, inadequate suturing by emergency room physicians brought on poor results. In adults, abrasions and traumatic tattoos occurring with late-night inebriation tended to develop some sequelae.

Accidental Falls↗
PubMed1993

Intrinsic proton modulation of excitatory transmission in rat hippocampal slices.

Recent work suggests that activity-induced alkaline transients within the interstitial space of nervous tissue are largely due to net fluxes of acid-base equivalents across postsynaptic receptor-gated ion channels. In view of the marked pH sensitivity of certain receptor channels, it has been frequently postulated that synaptically-evoked H+ shifts might play a neuromodulatory role. We provide here the first evidence to support the above hypothesis in showing that extracellularly recorded glutamatergic responses in area CA1 of rat hippocampal slices are potentiated upon inhibition of fast extracellular H+ buffering by a poorly-permeant carbonic anhydrase inhibitor, benzolamide (10 microM). Experiments with glutamate receptor antagonists and Mg(2+)-free solutions suggest that the action of benzolamide is mediated by the H+ sensitivity of N-methyl-D-aspartate (NMDA) receptor channels. In further agreement with an intrinsic neuromodulatory role for H+ in excitatory transmission, addition of the H+ buffer HEPES (20 mM) produced a selective attenuation of pharmacologically-isolated NMDA receptor-mediated responses.

2-Amino-5-phosphonovalerate↗
PubMed1993

Trajectory angle in stereotactic thalamotomy.

Most neurosurgeons use a frontal burr hole in stereotactic thalamotomy for movement disorders. However, the reports on this operation show a variation in trajectory with reference to the angles to the intercommissural line and the midsagittal plane. We studied the effect of the trajectory angles on operative results in 22 patients who underwent stereotactic thalamotomy for tremor control. The angle varied between 28 and 71 degrees (mean 44 +/- 10) in the sagittal plane, and between 0 and 25 (mean 11 +/- 7) in the coronal plane. There was linear correlation between the angles and the distances of a burr hole from the coronal suture and the midline. However, the angles did not show any correlation with the number of target corrections required, the size of the lesions made, tremor control and the incidence of complications. These findings indicate that the trajectory angle does not play an important role in stereotactic thalamotomy.

Adolescent↗
PubMed1993

A simple system for stereotactic volumetric resection.

Stereotactic volumetric resection of deep-seated intracerebral lesions is generally believed to require expensive and complex facilities. The authors report a simple system for stereotactic craniotomy, in which the software in the computed tomographic scanner and a personal computer are used for preoperative planning and intraoperative orientation.

Brain Neoplasms↗
PubMed1993

Evaluation of serum amyloid A protein as an acute-phase reactive protein in horses.

Serum amyloid A protein (SAA) was isolated from equine acute-phase serum by repeating Sephadex G-75 gel filtration 3 times. Quantitative measurement of equine SAA was performed by the single radial immunodiffusion technique with rabbit anti-equine SAA serum. In clinically normal horses, the SAA concentration remained relatively high from immediately after birth up to 1 week of age. After this the concentration showed periodic fluctiation in the range of approximately 13 to 30 micrograms/ml. The mean (+/- SD) concentration of SAA in foals (< or = 12 months old) and in adult horses (> or = 18 months old) was 19.37 +/- 9.41 and 21.53 +/- 9.81 micrograms/ml, respectively. In mares during the perinatal period, the SAA concentration remained stable and within the normal range for 4 months before parturition. After foaling, it increased quickly and reached a peak value of 136.78 +/- 56.74 micrograms/ml on day 3 postpartum, and then began to decrease at 2 weeks postpartum returning to within the normal range by 1 month postpartum. In horses with experimentally induced inflammation, the SAA concentration increased quickly, and reached the highest value, approximately 4 to 20 times higher than pre-treatment values, on day 2 after treatment. It then returned to the base line values within 10 days to 4 weeks, concurrent with the disappearance of local inflammatory signs. The SAA concentration was very high in most horses with clinical signs of inflammation. It was concluded from these data that equine SAA was a sensitive acute-phase reactive protein which increased in the early phase of various acute inflammations.

Acute-Phase Proteins↗