Establishment of public human tissue resource bank for research purposes with surgically removed tonsil tissue: potential scientific value and ethical problem.
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Ethics, Research↗
Biomedical subjects
N Tsuchihashi
Publications and source records attributed to N Tsuchihashi.
Radiographic diagnosis of congenital bony nasal stenosis.
Congenital bony nasal stenosis (CBNS) is a rare condition that causes respiratory distress in neonates. Between 1986 and 1996, we encountered 13 cases of CBNS. Recently, CT measurements have been used to evaluate the features of this type of stenosis, but no satisfactory investigation of the severity of bony nasal stenosis has been reported. We compared the nasal width (NW), facial width (FW), and interorbital distance (IOD) measured from occipitofrontal (Caldwell's) projections of plain radiographs in nine CBNS patients and nine normal infants. NW was significantly narrower in the CBNS patients than in the controls, and never exceeded the IOD in any of the CBNS patients. This measuring method can be used to diagnose CBNS, because NW in normal subjects of all age groups is always greater than IOD on Caldwell's view. We also investigated one patient radiographically, to determine how NW increased until the age of 4 years. However, there was no significant change in nasal width, although the FW increased significantly. This method seems useful for determining the severity of stenosis, and its simplicity makes it useful for routine investigation of breathing difficulty in neonates and infants. We review and discuss the CT images of CBNS reported in the literature.
Constriction, Pathologic↗
Dietary curdlan increases proliferation of bifidobacteria in the cecum of rats.
Significant increases in the amounts of short-chain fatty acids and lactate, and in numbers of bifidobacteria were observed in the cecum of curdlan (CD) -fed rats as compared with those of cellulose-fed ones. The in vitro proliferation of 5 species of bifidobacteria was markedly increased in the cultures containing the supernatant obtained from the cecal contents of CD-fed rats. These findings suggest that bifidus factors have been produced in the cecum of CD-fed rats.
Animals↗
Two YxxL segments of a single immunoreceptor tyrosine-based activation motif in the CD3zeta molecule differentially activate calcium mobilization and mitogen-activated protein kinase family pathways.
Immunoreceptor tyrosine-based activation motifs (ITAM), consisting of two YxxL segments, transmit signals leading to IL-2 gene activation in T cells. We investigated here the functional difference in signal transduction between these two YxxL segments in the CD3zeta membrane-proximal ITAM. N-terminal YxxL mutants failed to induce ZAP-70 phosphorylation, elevation of intracellular Ca2+ concentration ([Ca2+]i) or extracellular signal-regulated kinase (ERK) activation even in the presence of CD28 co-stimulation, whereas a mutant of the leucine residue at the C-terminal YxxL segment retained the ability to induce these events although this mutation abrogated the ability to induce IL-2 gene activation. In marked contrast to ERK activation, c-Jun N-terminal kinase (JNK) activation was observed in all mutants when co-stimulated with CD28. The mutant of the leucine residue at the C-terminal YxxL segment had a defect in the transcriptional activation at the NF-AT cis-element, which was restored to wild-type level by addition of a Ca2+ ionophore, suggesting that the intensity and/or duration of [Ca2+]i elevation defines the threshold of T cell activation in this mutant. Our data collectively indicate that the activation pathways of ERK, JNK and Ca2+ mobilization are differentially regulated through YxxL segments of an ITAM.
Amino Acid Sequence↗
Enhancement of nitroxide-reducing activity in rats after chronic administration of vitamin E, vitamin C, and idebenone examined by an in vivo electron spin resonance technique.
Rats were given vitamin E (Vit-E), idebenone (ID), or vitamin C (Vit-C) in their food for 2 or 4 weeks. After feeding, the ability of rats to reduce 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) in terms of the half-life of Tempol was examined as a specific marker. Tempol was repeatedly injected intravenously, and its half-life was serially evaluated by an in vivo electron spin resonance (ESR) technique. The radical-reducing ability in rats was enhanced differently by Vit-E, ID, and Vit-C, i.e., slow onset of the ability after Vit-E and ID (lipid-soluble antioxidants) and fast onset after Vit-C (a water-soluble antioxidant).
Animals↗
In vivo analysis of hydrogen peroxide and lipid radicals in the striatum of rats under long-term administration of a neuroleptic.
It has been hypothesized that free radicals play a causative role in tardive dyskinesia, which is an inveterate movement disorder caused by chronic administration of neuroleptics. To verify this hypothesis, rats were reared while being regularly treated with water containing a neuroleptic, haloperidol (HPD), for 1 year (HPD group). The changes in the striatal hydrogen peroxide content of the rats in the HPD and control groups were measured by using a Pt-disk microelectrode while the animals were in a freely moving state following intraperitoneal administration of HPD (HPD challenge). We also performed electron spin resonance (ESR) detection of lipid radicals in the striatum before the HPD challenge. HPD challenge led to significant elevation of the intrastriatal hydrogen peroxide in all animals, but the elevation in the HPD group was smaller than that in the control group. However, in the HPD group, marked ESR signals of intrastriatal lipid radicals were observed. We think that these results support the hypothesis on the role of free radicals in tardive dyskinesia.
Animals↗
In vivo electron spin resonance analysis of nitroxide radicals injected into a rat by a flexible surface-coil-type resonator as an endoscope- or a stethoscope-like device.
The flexible surface-coil-type resonator (FSCR) operating in a 700 MHz microwave electron spin resonance (ESR) system was applied to measure the nitroxide radicals at a specific area in rats. The FSCR was composed of a single-turn coil with a diameter of 5 mm and two flexible coaxial lines of 450 mm in length. For an endoscope-like application, the FSCR was inserted into the rectum of the rat and sequential changes in the ESR signals of the intravenously injected nitroxide radical (4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl; TEMPOL or 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy; carbamoyl-PROXYL) were measured. The ESR signal intensity of the nitroxide decreased according to first-order kinetics. For a stethoscope-like application, the FSCR was placed at several sites on the abdominal skin of the rats receiving a subcutaneous injection of carbamoyl-PROXYL, and diffusion and/or metabolism of the radical in the skin was observed.
Animals↗
A CT using longitudinally detected ESR (LODESR-CT) of intraperitoneally injected nitroxide radical in a rat's head.
We have developed an in vivo longitudinally detected ESR (LODESR) imaging system operating at 700 MHz based on a loop-gap resonator and a pair of saddle-type pickup coils. A good linear relationship between the LODESR signal intensity and the applied power in a range up to 15.8 W was obtained. The detection of LODESR signals was barely affected by variations in the resonant properties. The characteristic of LODESR is suitable for in vivo examination. Using this system, we succeeded in obtaining LODESR-CT images of the head region of a rat after the intraperitoneal injection of a nitroxide radical.
Animals↗
Hydrogen peroxide augmentation in a rat striatum after methamphetamine injection as monitored in vivo by a Pt-disk microelectrode.
We fabricated a Pt-disk microelectrode (diameter 30 microns) to conduct differential double-pulse amperometry (first step: 750 mV, 1 s; second step: 1,100 mV, 1 s) to detect hydrogen peroxide in the brain of a freely moving animal. This measurement determined hydrogen peroxide (detection limit, 0.03 microM) without any observable influence from other oxidizable species, such as dopamine (DA), ascorbic acid, or uric acid. The electrode was implanted into the right striatum of a rat. After intraperitoneal injection of methamphetamine (MAP), hydrogen peroxide concentrations were directly detected while the behavioral changes were monitored. MAP injection led to significant augmentation of hydrogen peroxide, the elevation of which depended on the dose of MAP. This is consistent with a previous report on the increase of DA-release caused by amphetamines and indirect evidence of the production of hydrogen peroxide via DA-metabolism.
Animals↗
Lingual cyst in infancy: importance of palpation for diagnosis.
Two infants, 5 and 12 weeks of age, with lingual cysts were presented. Histological findings were compatible with a salivary retention cyst in one and a thyroglossal duct cyst in the other. Both infants were admitted to our hospital because of severe stridor that had developed from one to two weeks of age. Their lingual cysts were easily recognizable by simple palpation and were confirmed by non-invasive imaging techniques, such as ultrasound sonography, computed tomography and magnetic resonance imaging. Lingual cyst in infancy may be large enough to cause stridor and dyspnea, and occasionally result in sudden infant death, although once diagnosis is made a radical operation can be easily performed. Therefore, it is important that palpation in the oral cavity should be performed with all infants with persistent stridor as a part of a physical examination.
Cysts↗
Delayed post-neonatal intensive care unit hearing disturbance.
Ten children, who developed hearing disturbance after discharge from the neonatal intensive care unit (NICU), are reported. All were born at full term, between November 1988 and November 1992, weighed at least 2500 g and had normal auditory brainstem response (ABR) at discharge from the NICU. All ten underwent thorough evaluation to determine the cause of the subsequent hearing loss. All had severe cardiovascular and/or pulmonary disorders at birth, and persistent pulmonary hypertension of the newborn (PPHN) was diagnosed in eight. A total of 25 PPHN cases were treated at our facility during the 1988-1992 period, the rate of hearing disturbance in PPHN patients being 32%. The 10 infants in this study were mechanically ventilated for, on average, 30 days. High frequency oxygenation (HFO) was required in five cases, extra corporeal membrane oxygenation (ECMO) in six. During this period, only eight ECMO-treated infants survived. The rate of hearing loss in surviving cases was therefore very high, 75% (6 8). All 10 of our cases were treated with an aminoglycoside, furosemide and a muscle relaxant. We recommend follow-up at 6 and 12 months of age, as these children are at very high risk of developing hearing disturbance.
Age of Onset↗
A spatiotemporal study on the distribution of intraperitoneally injected nitroxide radical in the rat head using an in vivo ESR imaging system.
We have developed a rapid-scan in vivo electron spin resonance (ESR) imaging system operating at 700 MHz based on an air-cored two-coil Helmholtz designed resistive magnet. Using this system, we performed ESR-CT for the intraperitoneally injected nitroxide radical, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl, in the rat head. The imaging data were collected over the time course range from 5 to 47 min after injection at an interval of 3 min and a series of ESR-CT images were reconstructed at the same slice plane (1 cm anterior to interaural line). The series of ESR-CT images thus obtained by rapid scans provided detailed spatiotemporal information on the distribution of the injected nitroxide radical in the rat head. The brain was imaged as a nitroxide-deficient area while the blood vessels and/or extracranium tissues as a nitroxide-rich area. During periods when high intensities of ESR signals were maintained, spots of nitroxide-accumulation were imaged at the central part of the brain. The spots were assigned to the middle sized blood vessels in the brain.
Animals↗
Electrocochleography during experimental cochlear ischemia of the guinea pig.
It has been postulated that impairment of cochlear blood flow (CoBF) is one of the most important causes of hearing loss occurring during acoustic neuroma (AN) surgery. However, it remains unclear how the degree of cochlear ischemia influences the evoked responses in electrocochleography. (ECochG) which has been used for monitoring cochlear functions. In the present study, we investigated alterations in ECochG during cochlear ischemia of varying degree in the guinea pig. In order to induce cochlear ischemia, the anterior inferior cerebellar artery (AICA) was mechanically compressed via the transclival approach. The compression of AICA resulted in the reduction of CoBF in 55 out of 70 guinea pigs. A constant reduction of CoBF was maintained during the compression of AICA in 44 (63%) guinea pigs. CoBF abruptly decreased upon compressing AICA, and promptly recovered after releasing the compression. N1 and N2 in ECochG were also altered by compression. During 3-min ischemia, N1 and N2 disappeared in 36% and 41% of the cases, respectively. The residual CoBF in cases whose N1 and N2 disappeared was significantly lower than that in other cases whose N1 and N2 were sustained during 3-min ischemia. In addition, there was a tendency that the lower the residual CoBF was, the shorter the survival time of N1 and N2. In cases whose N1 and N2 did not disappear, the prolongation of N1 and N2 latencies after 3-min ischemia was positively correlated to the residual CoBF. On the basis of these results, we discuss the mechanisms underlying the changes in CoBF and ECochG during cochlear ischemia, and conclude that the degree of cochlear ischemia during AN surgery can be estimated with ECochG.
Animals↗
Increase of central nitric oxide during pentylenetetrazol-induced seizures in rats.
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Animals↗
A surface-coil-type resonator for in vivo ESR measurements.
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Electron Spin Resonance Spectroscopy↗
Management of acute otitis media. Assessment of therapeutic strategy in Japan today.
Currently, myringotomy is widely used in the routine initial treatment of acute otitis media in Japan. In an attempt to evaluate the validity of this strategy, a number of issues that demand reassessment or clarification have been identified. These issues and factors contributing to the persisting uncertainty about myringotomy are examined.
Acute Disease↗
EPR and TREPR spectroscopic studies of antioxidant sesamolyl and related phenoxyl radicals.
Sesamolyl and related phenoxyl radicals were studied by conventional and time-resolved electron paramagnetic resonance (EPR) spectroscopic techniques. Continuous UV irradiation of sesamol in benzene produces two types of radicals. Based on the hyperfine coupling values obtained we determined that one is the neutral sesamolyl radical and the others are the dimer radicals. Comparison was made with related compounds, especially 3,4-dimethoxyphenol. We found that the 3,4-dimethoxyphenoxyl radical had a shorter lifetime than the neutral sesamolyl radical. The EPR results obtained suggest that a near perpendicular orientation of the oxygen p-orbitals with respect to the benzene ring of sesamol makes the radical more stable. This stability may be important for the antioxidant properties.
Antioxidants↗
Choanal atresia and congenital pharyngeal stenosis.
From 1980 to 1992, 8 patients with choanal atresia were treated in our facility. The female to male ratio was 5:3. One patient, a girl, had unilateral osseous obstruction with membranous closure of the opposite naris while the other 7 had bilateral osseous obstruction. Seven of the 8 had other congenital anomalies, CHARGE association (2 cases), Apert's syndrome (1 case), meningocele and banded fingers (1 case), omphalocele (1 case), subdural hematoma (1 case), and nasal fistula (1 case). Of the 7 patients who underwent endonasal surgical repair, 3 (40%) experienced reclosure. The remaining one patient, whose obstruction was of the bilateral osseous type, was successfully operated on via a transpalatal approach. Surgical correction is particularly difficult in those with craniofacial abnormalities, e.g. Apert's syndrome and maxillary hypoplasia. We treated 5 congenital pharyneal stenosis cases (CPS). Our CPS cases were divided into Types 1, 2 and 3, the latter being a new type not previously reported on. We consider Type 3 to be the result of fetal tissue remnants. We performed uvula splitting surgery in 4 cases and obtained good results in 3.
Abnormalities, Multiple↗