The insulin receptor-related receptor (Insrr) gene maps to mouse chromosome 3.
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Animals↗
Biomedical subjects
T Kunieda
Publications and source records attributed to T Kunieda.
[Definition, concept and pathophysiology of pulmonary hypertension].
Intravenous prostacyclin infusion has been introduced as breakthrough to the treatment of primary pulmonary hypertension(PPH) followed thus far inevitably by calamitous outcome and has recently promised a favorable outlook. Pulmonary hypertension (PH) is defined as pulmonary artery mean pressure exceeds 25 mmHg at rest in a lying position. The concept of PH was discussed historically down to date and has been usually used for the patient with sustained PH in vascular origin including PPH. Pathophysiology relating to the cause of PH has been focused on unexplained PH which is PH due to collagen, hepatoportal, congenital cardiac diseases, HIV infection and anorexigenics. Various intrinsic chemical mediators such as TXA2, ET-1, serotonin, eNOS, K channel and their antagonists give rise to PH. Genetics of PH was discussed around Gene PPH-1 disclosed by Genome Project. However, further attention should be paid for enormous pulmonary vascular reserve in normals, because PH occurs only when this reserve must be reduced to a critical level before medial muscular hypertrophy develops.
Epoprostenol↗
Physical aspects of a real-time tumor-tracking system for gated radiotherapy.
PURPOSE: To reduce uncertainty due to setup error and organ motion during radiotherapy of tumors in or near the lung, by means of real-time tumor tracking and gating of a linear accelerator. METHODS AND MATERIALS: The real-time tumor-tracking system consists of four sets of diagnostic X-ray television systems (two of which offer an unobstructed view of the patient at any time), an image processor unit, a gating control unit, and an image display unit. The system recognizes the position of a 2.0-mm gold marker in the human body 30 times per second using two X-ray television systems. The marker is inserted in or near the tumor using image guided implantation. The linear accelerator is gated to irradiate the tumor only when the marker is within a given tolerance from its planned coordinates relative to the isocenter. The accuracy of the system and the additional dose due to the diagnostic X-ray were examined in a phantom, and the geometric performance of the system was evaluated in 4 patients. RESULTS: The phantom experiment demonstrated that the geometric accuracy of the tumor-tracking system is better than 1.5 mm for moving targets up to a speed of 40 mm/s. The dose due to the diagnostic X-ray monitoring ranged from 0.01% to 1% of the target dose for a 2.0-Gy irradiation of a chest phantom. In 4 patients with lung cancer, the range of the coordinates of the tumor marker during irradiation was 2.5-5.3 mm, which would have been 9.6-38.4 mm without tracking. CONCLUSION: We successfully implemented and applied a tumor-tracking and gating system. The system significantly improves the accuracy of irradiation of targets in motion at the expense of an acceptable amount of diagnostic X-ray exposure.
Algorithms↗
A deletion of the paracellin-1 gene is responsible for renal tubular dysplasia in cattle.
Various hereditary diseases analogous to particular human heritable diseases have been identified in cattle. Investigation of these cattle diseases will provide useful information regarding the pathogenesis of the corresponding human diseases. Renal tubular dysplasia is an autosomal recessive disease of Japanese black cattle characterized by renal failure and growth retardation. We have previously mapped the locus responsible for the disease within a region on bovine chromosome 1. In the present study, we further typed additional markers in this region and found that a genomic segment of bovine chromosome 1 including the microsatellite marker BMS4009 was deleted in the affected animals. Construction of a physical map covering this region with BAC clones and comparison of the nucleotide sequences of this region between normal and affected animals revealed that a region of 37 kb including exons 1 to 4 of the bovine paracellin-1 gene was deleted in the affected animals. The paracellin-1 gene, which is the causative gene for human renal hypomagnesemia with hypercaciuria and nephrocalcinosis, encodes a tight junction protein of renal epithelial cells. Therefore, we concluded that deletion of the paracellin-1 gene is responsible for renal tubular dysplasia of cattle, and the cattle disease could be a good model for the human disease.
Amino Acid Sequence↗
Four-dimensional treatment planning and fluoroscopic real-time tumor tracking radiotherapy for moving tumor.
PURPOSE: To achieve precise three-dimensional (3D) conformal radiotherapy for mobile tumors, a new radiotherapy system and its treatment planning system were developed and used for clinical practice. METHODS AND MATERIALS: We developed a linear accelerator synchronized with a fluoroscopic real-time tumor tracking system by which 3D coordinates of a 2.0-mm gold marker in the tumor can be determined every 0.03 second. The 3D relationships between the marker and the tumor at different respiratory phases are evaluated using CT image at each respiratory phase, whereby the optimum phase can be selected to synchronize with irradiation (4D treatment planning). The linac is triggered to irradiate the tumor only when the marker is located within the region of the planned coordinates relative to the isocenter. RESULTS: The coordinates of the marker were detected with an accuracy of +/- 1 mm during radiotherapy in the phantom experiment. The time delay between recognition of the marker position and the start or stop of megavoltage X-ray irradiation was 0.03 second. Fourteen patients with various tumors were treated by conformal radiotherapy with a "tight" planning target volume (PTV) margin. They were surviving without relapse or complications with a median follow-up of 6 months. CONCLUSION: Fluoroscopic real-time tumor tracking radiotherapy following 4D treatment planning was developed and shown to be feasible to improve the accuracy of the radiotherapy for mobile tumors.
Computer Systems↗
Nonconvulsive focal inhibitory seizure: subdural recording from motor cortex.
The authors obtained an ictal electrocorticogram with chronically implanted subdural electrodes from a 30-year-old man with a low grade glioma in the right postcentral gyrus who had a focal inhibitory seizure of the left arm. During the ictal paresis, the authors observed epileptic discharges in the positive arm motor area of the right precentral gyrus and in its rostral area, but not in the negative motor area. The epileptic activity probably inhibited the spinal motoneuron pool without eliciting excitatory activity in the corticospinal pathway.
Adult↗
Autosomal dominant temporal lobe epilepsy in a Japanese family.
We described autosomal dominant familial temporal lobe epilepsy in a Japanese family in which three individuals (one man and his two children) were affected. Their seizures commonly consisted of auditory symptoms and infrequent nocturnal generalized seizures. Repeated EEGs did not provide confirmative epileptiform discharges, but cranial MRI in one patient showed mild left hippocampal atrophy, and decreased glucose metabolism in the left temporal area was demonstrated by 18F-deoxyglucose positron emission tomography (FDG-PET). A confirmative diagnosis in one of the patients by FDG-PET was helpful for diagnosis in other patients in the same family. Seizure onset was adolescent commonly among the three patients, but better seizure control was achieved in the father as compared with the two children.
Adult↗
Primary somatosensory cortex is actively involved in pain processing in human.
We recorded somatosensory evoked magnetic fields (SEFs) by a whole head magnetometer to elucidate cortical receptive areas involved in pain processing, focusing on the primary somatosensory cortex (SI), following painful CO(2) laser stimulation of the dorsum of the left hand in 12 healthy human subjects. In seven subjects, three spatially segregated cortical areas (contralateral SI and bilateral second (SII) somatosensory cortices) were simultaneously activated at around 210 ms after the stimulus, suggesting parallel processing of pain information in SI and SII. Equivalent current dipole (ECD) in SI pointed anteriorly in three subjects whereas posteriorly in the remaining four. We also recorded SEFs following electric stimulation of the left median nerve at wrist in three subjects. ECD of CO(2) laser stimulation was located medial-superior to that of electric stimulation in all three subjects. In addition, by direct recording of somatosensory evoked potentials (SEPs) from peri-Rolandic cortex by subdural electrodes in an epilepsy patient, we identified a response to the laser stimulation over the contralateral SI with the peak latency of 220 ms. Its distribution was similar to, but slightly wider than, that of P25 of electric SEPs. Taken together, it is postulated that the pain impulse is received in the crown of the postcentral gyrus in human.
Adult↗
Different activation of presupplementary motor area, supplementary motor area proper, and primary sensorimotor area, depending on the movement repetition rate in humans.
In order to clarify the functional role of the supplementary motor area (SMA) and its rostral part (pre-SMA) in relation to the rate of repetitive finger movements, we recorded movement-related cortical potentials (MRCPs) directly from the surface of the mesial frontal lobe by using subdural electrode grids implanted in four patients with intractable partial epilepsy. Two subregions in the SMA were identified based on the anatomical location and the different response to cortical stimulation. In three of the four subjects, we also recorded MRCPs from the surface of the lateral convexity covering the primary sensorimotor areas (SI-MI), which were defined by cortical stimulation and SEP recording. The subjects extended the middle finger or opposed the thumb against other fingers of the same hand at a self-paced rate of 0.2 Hz (slow) and 2 Hz (rapid), each in separate sessions. As a result, pre-and postmovement potentials were clearly seen at the SI-MI in both slow- and rapid-rate movements. By contrast, in the SMA, especially in the pre-SMA, premovement potentials were not seen and postmovement potentials were seldom seen in the rapid rate movement. In the slow-rate condition, pre- and postmovement potentials were clearly seen in both the pre-SMA and the SMA proper. In conclusion, the SMA, especially the pre-SMA, is less activated electrophysiologically in the rapid-rate movements, while the SI-MI remains active regardless of the movement rate.
Adolescent↗
Human presupplementary motor area is active before voluntary movement: subdural recording of Bereitschaftspotential from medial frontal cortex.
Bereitschaftspotential (BP) was recorded directly from the right supplementary motor area proper (SMA-proper) and its rostral part by chronically implanted subdural electrodes in three patients with intractable focal motor seizure. Cortical electrical stimulation of the SMA-proper revealed the somatotopy as previously reported, and the supplementary negative motor area (SNMA) was identified just anterior to the SMA-proper in two of three cases. In patient 1, eight kinds of simple movements, i.e., left and right middle finger extension, left arm abduction, left and right foot dorsiflexion, left knee extension, tongue protrusion and saccadic eye movement, were studied to record BP. In patient 2, three kinds of movements, i.e., left and right middle finger extension and left foot dorsiflexion, were adopted as movement tasks. In patient 3, four kinds of movements, i.e., left and right middle finger extension and left and right foot dorsiflexion, were adopted. In the SMA-proper, somatotopically distributed BP preceding movements were observed in all three patients. In the SNMA and its rostrally adjacent areas, "SNMA-plus" BPs were generated invariably regardless of the sites of movement. There was no significant difference in the onset time of BPs between the SMA-proper and the SNMA-plus. The present findings suggest that the SNMA-plus is more consistently involved in the preparation for various simple movements than the SMA-proper. This functionally independent region (SNMA-plus) just rostral to the SMA-proper most likely corresponds to a part of the presupplementary motor area which was originally defined in nonhuman primates. Since a part of this area elicited the inhibition of various movements by cortical stimulation, and since it generated BPs regardless of the sites of movement, it may play a higher role in the movement preparatory process than the SMA-proper.
Adult↗
Homozygosity mapping of the locus responsible for renal tubular dysplasia of cattle on bovine chromosome 1.
Renal tubular dysplasia is a hereditary disease of Japanese black cattle showing renal failure and growth retardation with an autosomal recessive trait. In the present study, we mapped the locus responsible for the disease (RTD) by linkage analysis with an inbred paternal half-sib pedigree obtained from commercial herds. By analyzing segregation of microsatellite markers in the half-sibs, significant linkage was observed between the RTD locus and markers on bovine Chromosome (Chr) 1 with the highest lod score of 11.4. Homozygosity mapping with the inbred pedigree further defined the localization of the RTD locus in a 4-cM region between microsatellite markers BMS4003 and INRA119. Mapping of the RTD locus on bovine Chr 1 will facilitate cloning and characterization of the gene responsible for this disease.
Animals↗
Electrocorticogram-electromyogram coherence during isometric contraction of hand muscle in human.
OBJECTIVE: To clarify how the primary sensorimotor and supplementary motor areas are involved in the generation of the rhythmicity of electromyogram (EMG) activity during continuous muscle contraction. METHOD: We analyzed the coherence between subdurally recorded cortical electroencephalograms (EEG) and EMGs of the contralateral wrist extensor muscle during continuous isometric contraction in 8 patients with medically intractable epilepsy. RESULTS: In all subjects, a significant coherence between the primary motor area (M1) and EMG was observed at the peak frequency of 15+/-3 Hz (means+/-SD). In the primary somatosensory area (S1) of 7 subjects and the supplementary motor area proper (SMA proper) of 4 subjects, significant coherence with EMG was observed at 12+/-5 and 15+/-4 Hz, respectively. The time lags revealed by cross-correlogram were 10+/-3, 7+/-1 and 22+/-8 ms in the M1, S1 and SMA proper, respectively, with the EMG lagging in all areas. CONCLUSION: These findings suggest that the rhythmic activity in the SMA proper, as well as in the S1 and M1, is related to the generation of the rhythmicity of EMG activity.
Electromyography↗
Localization of the locus responsible for Chediak-Higashi syndrome in cattle to bovine chromosome 28.
Chediak-Higashi syndrome in Japanese black cattle is a hereditary disease with prolonged bleeding time and partial albinism. In the present study, we mapped the locus responsible for the disease (CHS) by linkage analysis using microsatellite genotypes of paternal half-sib pedigrees obtained from commercial herds. Analysis revealed significant linkage between the CHS locus and marker loci on the proximal end of bovine chromosome 28. The CHS locus was mapped on the region incorporating the microsatellite markers BMC6020, BM2892, and RM016 with recombination fraction 0 and lod score 4.9-11.2. We also assigned the bovine CHS1/LYST, the homologue of the gene responsible for human Chediak-Higashi syndrome, to bovine chromosome 28 using a bovine/murine somatic cell hybrid panel. These findings suggest that a mutation in the CHS1/LYST gene is likely to be responsible for Chediak-Higashi syndrome in Japanese black cattle.
Animals↗
Movement-related change of electrocorticographic activity in human supplementary motor area proper.
We investigated movement-related change in the cortical EEG signal by simultaneous recording from the primary sensorimotor area (S1-M1) and the supplementary motor area proper (SMA proper) in four patients with intractable partial epilepsy. By the use of temporal spectral evolution (TSE) analysis, the change in background cortical activity in relation to self-paced finger/wrist extension was compared among the SMA proper, S1 and M1. All three areas showed a decrease in the amount of activity for the frequency range between 10 and 40 Hz before the onset of movement [event-related desynchronization (ERD)]. The SMA proper showed earlier onset of ERD for 18-22 Hz activity (-3.4 +/- 0.5 s, mean +/- standard deviation) than M1 (-1.7 +/- 0.7 s) and S1 (-1.4 +/- 0.5 s). The degree of ERD in S1 was greatest for 10-14 Hz and that in M1 for 18-22 Hz, whereas in the SMA proper ERD was observed throughout the frequency bands from 10 to 40 Hz. Neither the degree nor the onset time of ERD in the SMA proper was lateralized to either the ipsilateral or the contralateral side with respect to the movement. A transient increase in activity after movement [event-related synchronization (ERS)] was observed in all three areas. In the SMA proper, two out of four subjects showed ERS for frequency bands below 40 Hz with both ipsilateral and contralateral movements. By contrast, in S1 and M1, ERS was recorded for frequency bands between 20 and 90 Hz, and was predominantly associated with the contralateral movement. The present study suggests that the background cortical activity in the SMA proper has a specific temporal pattern with respect to self-paced movement, and that the SMA proper is involved in motor preparation earlier than S1-M1 in a bilaterally organized manner.
Adult↗
Role of primary sensorimotor cortices in generating inhibitory motor response in humans.
To clarify the mechanism by which inhibitory motor responses such as cortical negative myoclonus are generated in humans, three patients with medically intractable partial epilepsy (two with frontal lobe epilepsy and one with parietal lobe epilepsy) were studied by means of direct cortical stimulation with a single electric pulse through subdural electrodes. All underwent chronic long-term video/EEG monitoring, cortical mapping by 50 Hz electric cortical stimulation and recording of cortical somatosensory evoked potentials with chronically implanted subdural grid electrodes (3 mm in diameter and centre-to-centre distance of 1 cm) to map both epileptogenic and functional zones. After these clinical evaluations, cortical stimulation by single electric pulse (0.3 ms duration, 1 Hz) was carried out through pairs of subdural electrodes located at the primary sensorimotor area (MI-SI), pre-supplementary motor area (pre-SMA) and lateral negative motor area (lateral NMA), while surface EMG was recorded from the muscles of the contralateral hand. The results showed that (i) in all subjects, single pulse stimulation of MI-SI elicited a motor evoked potential (MEP) followed by a silent period (SP) in the contralateral distal hand muscles, the latter lasting 300 ms after the stimulus. The duration of SP was proportional to the size of the preceding MEP. In one subject, SP without any preceding MEP was elicited, and, in another subject, there was a short SP immediately before MEP in the contralateral thenar muscle. (ii) Following the stimulation of either pre-SMA or lateral NMA, no SP was observed. It is concluded that the inhibitory mechanism within the MI-SI, but probably not in the non-primary motor areas, either closely linked to or completely independent of excitation, most likely plays an important role in eliciting brief negative motor phenomena such as cortical negative myoclonus or SP.
Adult↗
Use of cavernous sinus EEG in the detection of seizure onset and spread in mesial temporal lobe epilepsy.
PURPOSE: The study goal was to evaluate the clinical usefulness of intravenous EEG recording by placing wire electrodes in the cavernous sinus (CS) and the superior petrosal sinus (SPS) in patients with intractable temporal lobe epilepsy (TLE), with special emphasis on the ictal recording. METHODS: We placed Seeker Lite-10 guide wire as electrodes in the bilateral CS, SPS, or both to simultaneously record both ictal and interictal EEGs with the scalp EEG in five patients with TLE. In addition, in one patient, we averaged interictal scalp and intravascular EEG time-locked to the epileptiform discharge recorded from the CS/SPS-EEG to further delineate the relationship of the spikes between scalp and intravenous recording. RESULTS: In four of five patients, clinically useful recording was obtained to determine ictal focus. We recorded habitual seizures in three patients, and the detailed characteristics of ictal epileptiform discharges were shown. The averaged waveform of interictal epileptiform discharges clarified the spike distribution in the scalp EEGs, which was otherwise undetectable in the single trace. All of the patients completed the intravenous EEG monitoring without any neurological or psychological problems. CONCLUSIONS: The CS/SPS-EEG is a relatively noninvasive method that is useful for the detection of ictal focus and its spreading pattern and thus for the selection of surgical candidate among patients with intractable TLE. Although the number of seizures detected during the short monitoring period may be limited, due to the advantages of its safety and simplicity, it is worth trying for potential surgical candidates before more invasive examinations are applied. A further study with a larger number of patients is needed to estimate its practical risk.
Adult↗
Sterically constrained 'roofed' 2-thiazolidinones as excellent chiral auxiliaries.
The "roofed" chiral 2-thiazolidinones, which are sterically congested and conformational rigid, and which are prepared by the [4+2] cycloaddition of 2-thiazolone to the cyclic dienes, dimethylanthracene and hexamethylcyclopentadiene, followed by optical resolution with (1S,2R)-2-methoxy-1-apocamphanecarbonic acid (MAC acid) are of considerable promise for use as chiral auxiliaries for the alkylation of enolates.
Magnetic Resonance Spectroscopy↗
[Efficient chiral control based on five-membered heterocyclic and related systems].
The synthetic potential of some simple five-membered heterocycles, including 2-oxazolone, 1,3-dihydro-2-imidazolone and 2-thiazolone as building blocks for chiral polyfunctional compounds as well as chiral heterocyclic auxiliaries for asymmetric synthesis is reviewed. The stereodefined introduction of easily replaceable groups to the 4,5-olefinic moiety of the 2-oxazolone ring to give versatile chiral synthons, followed by stereospecific and stepwise substitution, provides a working and versatile strategy for achieving a chiral synthesis, which leads to the preparation of a wide variety of 2-amino alcohols of biological interest. Sterically constrained chiral 2-oxazolidinones and the derived conformationally rigid amino alcohols, which are derived from cycloaddition reactions of the 2-oxazolone to cyclic dienes such as 9,10-dimethylanthracene and hexamethylcyclopentadiene, represent excellent chiral auxiliaries and chiral ligands which are of general use in asymmetric synthesis. The strategy developed using 2-oxazolone can also be used in the cases of the structurally similar 1,3-dihydro-2-imidazolone and 2-thiazolone derivatives.
Chemistry, Organic↗