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Biomedical subjects

S Sugimoto

Publications and source records attributed to S Sugimoto.

At least 19 recordsLinked to original sources
PubMed1998

DSIF, a novel transcription elongation factor that regulates RNA polymerase II processivity, is composed of human Spt4 and Spt5 homologs.

We report the identification of a transcription elongation factor from HeLa cell nuclear extracts that causes pausing of RNA polymerase II (Pol II) in conjunction with the transcription inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB). This factor, termed DRB sensitivity-inducing factor (DSIF), is also required for transcription inhibition by H8. DSIF has been purified and is composed of 160-kD (p160) and 14-kD (p14) subunits. Isolation of a cDNA encoding DSIF p160 shows it to be a homolog of the Saccharomyces cerevisiae transcription factor Spt5. Recombinant Supt4h protein, the human homolog of yeast Spt4, is functionally equivalent to DSIF p14, indicating that DSIF is composed of the human homologs of Spt4 and Spt5. In addition to its negative role in elongation, DSIF is able to stimulate the rate of elongation by RNA Pol II in a reaction containing limiting concentrations of ribonucleoside triphosphates. A role for DSIF in transcription elongation is further supported by the fact that p160 has a region homologous to the bacterial elongation factor NusG. The combination of biochemical studies on DSIF and genetic analysis of Spt4 and Spt5 in yeast, also in this issue, indicates that DSIF associates with RNA Pol II and regulates its processivity in vitro and in vivo.

Amino Acid Sequence↗
PubMed1998

Developmental changes in the NGF content in the brain of young, growing, low-birth-weight rats.

The NGF content in each region of the brain of four-week-old rats was ranked in the decreasing order of cerebral cortex, hippocampus, cerebellum, midbrain/diencephalon, and pons/medulla oblongata, and the NGF concentration, in the decreasing order of hippocampus, cerebral cortex, cerebellum, midbrain/diencephalon, and pons/medulla oblongata in both AFD and SFD groups. The NGF content and concentration in the cerebral cortex were about the same value at each age between those in the AFD and SFD groups. Those in the hippocampus were a little higher in the SFD group than in the AFD group at the ages of three and four weeks, unlike those in the other regions, where the values for the cerebellum, midbrain/diencephalon and pons/medulla oblongata tended to be somewhat higher in the AFD group than in the SFD group. The NGF concentrations in the hippocampus and cerebral cortex increased with growth: the concentration in the hippocampus at four weeks of age was about 4-fold of that at one week in the AFD group and about 5.7-fold of that at one week in the SFD group; and likewise the concentration in the cerebral cortex at four weeks of age was about 5.3-fold in the AFD group and about 7-fold in the SFD group. The NGF concentrations in the cerebellum decreased, and those in midbrain/diencephalon and pons/medulla oblongata hardly changed with growth in either AFD or SFD group. From these results NGF may have stronger implications for the neuronal growth in the hippocampus compared with those in the lower brain regions of the SFD rats.

Animals↗
PubMed1998

Cervical spinal epidural abscess following acupuncture: successful treatment with antibiotics.

A 67-year-old man with poorly controlled diabetes mellitus (DM) had acupuncture several times a month for chronic shoulder muscle stiffness. A few days after acupuncture in the posterior nuchal region, a low-grade fever and backache developed, and subacutely progressed. Finally he complained of gait disturbance, and then respiratory distress appeared. Magnetic resonance imaging (MRI) demonstrated high cervical epidural abscess with massive soft tissue inflammation and vertebral osteomyelitis. Conservative treatment with antibiotics was effective and it was well documented by following serial MRIs. This case suggested that needle acupuncture should be avoided for immunocompromised subjects such as patients with poorly controlled DM.

Abscess↗
PubMed1998

[An abnormality of facial nerve conduction velocity distribution (FNCVD) in Bell's palsy patients].

We studied bilateral facial nerve conduction velocity distribution (FNCVD) of 8 Bell's palsy patients in their paretic and recovered state and unilateral FNCVD of 13 normal control using collision method. Dual supramaximal stimuli were adapted to marginalis mandibulae branch of facial nerve and compound muscle action potential (CMAP) was recorded from the surface of mentalis muscles. Peak of FNCVD in normal control was present at 22-23 m/sec. In Bell's palsy patients, there was no significant change in FNCVD either at paretic or recovery state. Peak of involved side FNCVD of Bell's palsy patient was almost normal but its amplitude was low. However, in healthy side of Bell's palsy patient, peak of FNCVD was present at 18-19 m/sec. This finding shows that facial nerve diameter distribution in the healthy side of Bell's palsy patient has smaller peak than that of normal control.

Action Potentials↗
PubMed1998

[A case report of aortic valve replacement and ascending + hemi aortic arch replacement for congenital bicuspid aortic stenosis with poststenotic dilatation of ascending aorta].

The patient of 21-year-old female, who had undergone VSD closures at the age 5 and had been pointed out to have aortic valve stenosis at that time, was admitted to our hospital with complaints of palpitation and easy fatigability. Pressure gradient of 140 mmHg between left ventricle and ascending aorta, and poststenotic dilatation of max 55 mm in diameter from ascending aorta to hemi aortic arch was recognized by cardiac catheterization and aortogram. For fear of aortic dissection in late phase caused by dilatation of ascending aorta left over, graft replacement from ascending aorta to hemi aortic arch was carried out simultaneously adding to aortic valve replacement (AVR). We are of the opinion that not only AVR but also simultaneous graft replacement should be performed actively on the case with dilatation of ascending aorta of over 55 mm in diameter in order to prevent aortic dissection.

Adult↗
PubMed1998

[Removal of the left atrial myxoma combined with coronary artery bypass grafting in an elderly patient].

The case of simultaneous coronary artery bypass grafting with resection of the leat atrial myxoma is rarely reported. We surgically treated a 81-year-old woman who had been diagnosed as left atrial myxoma and unstable angina. At surgery we performed coronary artery bypass grafting prior to resection left atrial myxoma, because we thought it is the most important to protect myocardium by antegrade cardioplegia in the consequence of CABG. Postoperative course was excellent and uneventful. The patient is doing well now.

Aged↗
PubMed1998

[A case of a chronic traumatic thoracic aneurysm with compression of left main bronchus at the isthmus].

We report a case of traumatic thoracic aortic aneurysm found by occurrence of pulmonary atelectasis in the chronic phase. The patient, an 18-year-old female, was hospitalized with multiple trauma caused by a traffic accident. At the time of hospitalization, no thoracic trauma was found but a fracture of the pelvis and one leg was recognized. 45 days after the initial trauma, a pulmonary atelectasis on the left lung was found on a chest X-ray film. By chest CT and angiography, the pulmonary atelectasis was proved to be caused by compression of the left main bronchus by a traumatic aneurysm of the thoracic aorta. 55 days after the initial trauma, resection of the aneurysm and graft replacement was performed. Postoperative course was satisfactory. In conclusion, possibility of an injury to the thoracic aorta should be considered on the treatment for the patient with multiple trauma in the chronic phase as well as in the acute phase.

Adolescent↗
PubMed1997

Optical imaging of dynamic horizontal spread of excitation in rat auditory cortex slices.

Optical recordings using a voltage-sensitive dye (RH482) were conducted in brain slice preparations to investigate spatiotemporal patterns of excitation in the rat auditory cortex. Electrical stimulation of the border between the white matter and layer VI evoked vertical as well as horizontal spreading responses. While velocities of vertical and horizontal propagation of excitation were similar to those reported in non-disinhibited preparations, the horizontal propagation was widespread and strong especially in layers II/III in auditory cortex slices. This horizontal spread was blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) but not by D-2-amino-5-phosphonopentanoic acid (D-AP5). These results suggest that the horizontal responses, especially in layers II/III, are prominent and are mediated primarily by non-N-methyl-D-aspartic acid (NMDA) receptors in the auditory cortex.

2-Amino-5-phosphonovalerate↗
PubMed1997

Rhabdomyoma of the orbit in a child.

PURPOSE: To study a case of rhabdomyoma of the orbit in a 16-month-old boy. METHOD: The child had progressive right proptosis for 1 month. He underwent a computed tomographic scan, which showed an irregular right retrobulbar mass and partial resection. RESULTS: Histologic examination disclosed well-differentiated striated muscle cells with a mixture of collagen fibers and immature striated muscle cells with centrally placed nuclei. The specimen lacked nuclear atypia, indicating benign rhabdomyoma of the orbit. During the 1 1/2-year follow-up, the patient did not receive additional treatment, and no regrowth occurred. CONCLUSION: Rhabdomyoma can occur in the orbit of a child. Because of differences in treatment, rhabdomyoma must be distinguished from rhabdomyosarcoma.

Humans↗
PubMed1997

The columnar and layer-specific response properties of neurons in the primary auditory cortex of Mongolian gerbils.

The columnar and layer-specific response properties of neurons in the primary auditory cortex (AI) of Mongolian gerbils were studied using single-unit recordings of responses to tone-burst stimuli presented to the ear contralateral to the recording side. During near-radial microelectrode penetrations of the AI in 100-microm steps, the best frequency (BF), best threshold (BT), best amplitude (BA), latency, tuning curve and Q10dB were recorded. Neurons encountered during single penetrations showed similar BFs, indicating a columnar frequency organization, but their latencies and Q10dBs differed. The BAs and BTs recorded within single penetrations often showed a similar value in the middle cortical layers. The latencies and Q10dBs of these neurons exhibited a tendency toward a layer-specific distribution. The latencies of neurons located in layers I-V were longer than those located in layer VI. The Q10dBs of neurons located in layers III and IV were higher than those located in layers I and VI. These results are almost consistent with those of previous studies on frequency representation, and indicated the existence of an integrative mechanism of frequency processing in the AI. This is the first study in which a layer-specific, partially columnar organization for stimulus amplitude is described.

Acoustic Stimulation↗
PubMed1997

Correlation of middle latency auditory evoked potentials and cerebral blood flow changes.

The purpose of this study is to find the correlation between middle latency auditory evoked potentials (MLAEP) and sound activated single photon emission computed tomography (SPECT) studies. This study was performed on six normal right-handed volunteers with a mean age of 35.2 +/- 7.6 years, using the split-dose technique. First, a SPECT study was performed on subjects in blinded, awake and silent states. After bilateral ears were stimulated with a click sound, MLAEP and a second SPECT study were performed. Subtraction of the first SPECT from the second SPECT revealed a statistically significant increase of cerebral blood flow (CBF) in the bilateral superior temporal region. Bilateral Na amplitudes of MLAEP had a statistically significant and good correlation with the percentages of CBF changes in the bilateral superior temporal region. The superior temporal cerebral blood flow activation can be expressed by electrophysiological activation. Moreover, correlation during the left Na components and left frontal and occipital lobe are discussed.

Adult↗
PubMed1997

Is family history an independent risk factor for stroke?

OBJECTIVE: To estimate the influence of family history on the occurrence of stroke. METHODS: A case-control study was carried out from August 1992 to January 1994. The study population comprised 502 patients with a first stroke, aged between 20 and 70 years, who were treated at 48 affiliated hospitals. The same number of age and sex matched controls were selected from outpatients. Diagnoses were based on CT findings and clinical signs. There were 155 case-control pairs for subarachnoid haemorrhage, 158 for intracerebral haematoma, and 159 for cerebral infarction. Information about the patients and their families was obtained from a questionnaire which included the family histories of each subtype of stroke and other potential risk factors for stroke. The data were analysed focusing on the role of the family histories in the occurrence of stroke. RESULTS: In univariate analysis, the family histories of subarachnoid haemorrhage and intracerebral haematoma were positively associated with each of the subtypes of stroke (odds ratios 11.24 for subarachnoid haemorrhage, 2.39 for intracerebral haematoma), whereas family history of cerebral infarction was not a significant risk factor for its occurrence (odds ratio 1.41). Family history of intracerebral haematoma was correlated with a personal history of hypertension and habitual alcohol consumption. After adjustment for potential risk factors (hypertension, diabetes, hyperlipidaemia, obesity, alcohol consumption, and regular smoking), family history of subarachnoid haemorrhage still remained the most powerful risk factor for subarachnoid haemorrhage, whereas family history of intracerebral haematoma no longer showed a significant association with haematoma. CONCLUSION: Genetic factors play a major part in the pathogenesis of subarachnoid haemorrhage, and family history of subarachnoid haemorrhage is the strongest independent risk factor for the disease. On the other hand, family history of intracerebral haematoma was not an independent risk factor for haematoma, but it might be a good predictor, which indirectly influences the pathogenesis of intracerebral haematoma via certain hereditary components such as hypertension, and even lifestyle factors such as alcohol consumption. In cerebral infarction, genetic factors play a minor part in its pathogenesis.

Adult↗
PubMed1997

[A procedure for electroretinogram (ERG) recording in mice--effect of monoiodoacetic acid on the ERG in pigmented mice].

A procedure for recording the electroretinogram (ERG) in pigmented mice, C57BL, based on the ERG recording technique reported previously in albino mice, ICR, and giving careful consideration to the influence of anesthetics and dark-adaptation, was developed in order to examine retinal toxicity. Pigmented mice were given a single i.v. injection of monoiodoacetic acid (IAA), a known retinotoxic compound, via a tail vein at a dose of 30, 45 or 60 mg/kg, and the ERG was recorded periodically over the next 14 days. In addition, the retinas were examined histopathologically on day 15. The results were as follows. 1. The oscillatory potentials were not distinct in the ERGs from mice anesthetized with pentobarbital as compared to the ERGs from non-anesthetized mice. ERG waveforms obtained from mice anesthetized with a mixture of urethane, xylazine and ketamine or xylazine and ketamine were almost the same as those obtained from non-anesthetized mice. Therefore, the ERGs were recorded under mixed anesthesia, ketamine and xylazine, in the following study. Stable ERGs could be recorded after 40 min of dark-adaptation. 2. IAA at doses of 30 and 45 mg/kg caused slight depression of the amplitudes of the a-, b- and c-waves; however, these changes were no longer observed 7 days after dosing. At a dose of 60 mg/kg, the ERG waves were markedly depressed 1 day after dosing, and recovery was not observed until day 14. 3. Upon histopathologic examination of the retinas, a remarkable decrease in visual cells and thinning of the rod and cone layers and outer plexiform layer were observed with IAA at a dose of 60 mg/kg. 4. Using this newly developed recording technique, it was confirmed that stable ERGs could be recorded from pigmented mice repeatedly for 14 days, and the effects of IAA on the ERG could be detected. Histopathological abnormalities in the retinas correlated well with the changes in the ERGs. These results indicate that the newly developed ERG recording procedure is useful for evaluating retinal toxicity in pigmented mice.

Anesthesia↗
PubMed1997

[A case report of total aortic arch replacement for distal aortic arch aneurysm in an octogenarian].

A 81-year-old man was admitted to our hospital because of hoarseness. Chest CT scan and aortogram showed distal arch aneurysm measuring 7.5 cm in diameter. Under deep hypothermia and selective cerebral perfusion, the distal aortic arch aneurysm was completely replaced with a woven Dacron graft with three limbs for the arch vessels. After the aortic cross clamp was released, severe low output syndrome (LOS) continued because of perioperative myocardial infarction. Then, a coronary artery bypass grafting (CABG) to the left anterior descending artery (LAD) was performed, after which the cardiopulmonary bypass was easily weaned under intra-aortic balloon counterpulsation (IABP) assistance. The postoperative course was uneventful. The perioperative myocardial infarction was thought to be induced by left coronary spasm, as comparison of the preoperative and postoperative coronary arteriograms showed no change.

Aged↗
PubMed1997

[Three-stage operation for multifocal aortic aneurysms--a case report].

A 72-year-old man underwent a three-stage operation for aneurysms of the distal aortic arch, descending thoracic aorta, and infrarenal abdominal aorta. Graft replacement of the abdominal aortic aneurysm was performed as an emergency because of suspicion of impending rupture. Operations for the aneurysms of the thoracic descending aorta and distal aortic arch were performed 2 months and 4 months later, respectively. The patient was well 16 months after discharge from the hospital. This is the first report of the successful three-stage surgical treatment of three isolated aortic aneurysms. The therapeutic principles for multifocal aortic aneurysms remain controversial. The strategy of surgical treatment for multifocal aortic aneurysms is discussed and previous literature is reviewed.

Aged↗
PubMed1997

[Surgical treatment for endocardial cushion defect in an elderly patient with pulmonary hypertension].

We performed surgery for a partial endocardial cushion defect (ECD) in a 67-year-old female patient with pulmonary hypertension. The patient had grade 2 tricuspid regurgitation and pulmonary hypertension (Pp/Ps = 0.58, Rp = 8.4 Um2). The operative procedure involved patch closure of the ostium primum and tricuspid annuloplasty with a Carpentier ring. The postoperative course was uneventful and the pulmonary hypertension improved (Pp/Ps = 0.33). Surgery for partial ECD should be recommended even for elderly patients.

Aged↗
PubMed1996

Effects of eel neuropeptide Y on ion transport across the seawater eel intestine.

A neuropeptide Y (eNPY) was isolated from the intestinal extract of eels. This peptide enhanced significantly the serosa-negative transepithelial potential difference (PD) and short-circuit current (Isc) across the intestine of the seawater eel after pretreatment with isobutylmethylxanthine, serotonin and methacholine. The effects of eNPY on the Isc were concentration-dependent with a threshold concentration of 3 x 10(-9) M and a maximal effect at 3 x 10(-7) M. Similar concentration-response curve was obtained by porcine peptide YY (pPYY). Since 9 amino acid residues are replaced in the pPYY, this result indicates that these substitutions do not change the potency and the efficacy. These stimulatory actions of eNPY were not blocked by tetrodotoxin, an inhibitor of neural firing, or yohimbine, an alpha 2-adrenoceptor antagonist, indicating that eNPY acts without enteric neural firing or catecholamine release. When eNPY and adrenaline (AD) were applied simultaneously, the effects were additive only at lower dosage (3 x 10(-8) M for eNPY, 3 x 10(-8) M for AD), but not at high dosage (10(-6) M eNPY, 10(-7) M AD). The ceiling effect at high dosage suggests that these two regulators act through common signal transduction systems and affect the Na(+)-K(+)-Cl- cotransport system, since both effects were completely blocked by bumetanide, a specific inhibitor of Na(+)-K(+)-Cl- cotransporter.

Amino Acid Sequence↗