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Biomedical subjects

N Sakai

Publications and source records attributed to N Sakai.

At least 91 records · Page 5Linked to original sources

Analysis of the isoform of Xenopus euakryotic translation initiation factor 4E.

We have found two isoforms of the eukaryotic translation initiation factor 4E (eIF4E) in Xenopus laevis. These proteins differ in length by 18 amino acids. Overexpression of either of the two eIF4E proteins modestly increase translation in Xenopus oocytes. The results suggest that both of these two isoforms function in translation.

Amino Acid Motifs↗

Serum levels of KL-6 reflect disease activity of interstitial pneumonia associated with ANCA-related vasculitis.

OBJECTIVE: KL-6 is reported to be excreted from the lung alveolar and bronchial epithelial cells and may be a good marker for monitoring disease activity of interstitial pneumonia. This study was designed to ascertain the clinical significance of serum KL-6 levels in interstitial pneumonia associated with anti-neutrophil cytoplasmic antibody (ANCA)-related vasculitis. METHODS: Serum KL-6 levels were determined by an enzyme-linked immunosorbent assay. PATIENTS: We examined 20 healthy subjects, 13 patients with perinuclear (myeloperoxidase, MPO) ANCA-related vasculitis and 12 dermatomyositis (DM)/polymyositis (PM) patients as disease controls in this study. Six out of 13 patients with ANCA-related vasculitis had interstitial pneumonia. RESULTS: Serum levels of KL-6 in ANCA-positive patients with interstitial pneumonia were significantly elevated, while they remained as low as those of healthy subjects in ANCA-positive patients without interstitial pneumonia. Similarly, KL-6 levels in sera were higher in 12 dermatomyositis/polymyositis patients with interstitial pneumonia, while they remained low in DM/PM patients without interstitial pneumonia. Moreover, the elevated serum KL-6 level was reduced during the convalescence induced by glucocorticoid therapy and reflected the disease activity of interstitial pneumonia associated with ANCA-related vasculitis. CONCLUSION: These data suggest that the measurement of serum KL-6 levels may be a good monitoring system for the diagnosis and follow-up of interstitial pneumonia of patients with ANCA-related vasculitis.

Aged↗

Cerebral ischemic complications following intracranial bleeding in patients with moyamoya disease--three case reports.

Three patients with bleeding-type moyamoya disease suffered ischemic complications following their first episode of intracranial bleeding. The patients presented with intraventricular hemorrhage and suffered cerebral infarction on the 14th, 16th, and 11th days after the ictus, respectively. The clinical records revealed no obvious hypotension before progression to infarction and suggested that dehydration accelerated by the administration of hyperosmotic drugs was a contributing factor to the infarction. Two patients underwent superficial temporal artery-middle cerebral artery anastomoses in the chronic stages and have never experienced further ischemic complications. The other patient died despite receiving intensive care. Hemodynamic reserve may be severely impaired in patients with bleeding-type moyamoya disease. Adequate control of hydration is important to prevent cerebral infarction after intracranial bleeding in patients with moyamoya disease.

Adolescent↗

Enhancement of sweetness ratings of aspartame by a vanilla odor presented either by orthonasal or retronasal routes.

When taste stimuli are presented with specific odor stimuli, the perceived intensity of taste is enhanced, a phenomenon called odor-induced taste enhancement. There is a possibility, however, that the odor substances might have stimulated the taste receptors in the oral cavity as well as odor receptors in the nasal cavity because the odor substances were dissolved in the taste solutions in some preceding studies. Schifferstein and Verlegh (1996) found that the odor-induced taste enhancement effect was not found when the subjects wore a nose clip to prevent the olfactory perception. Thus, it was suggested that the odor-induced taste enhancement did not result from the stimulation of receptors in the oral cavity. To confirm and extend their study, we presented the odor stimuli simultaneously with, but not dissolved in, the taste stimuli with a more advanced approach to stimulus presentation. The participants reported enhancement of sweetness ratings for aspartame when the taste stimuli were presented with a vanilla odor. This odor induced taste enhancement was found when the gaseous odor stimuli were presented either by the retronasal route or by the orthonasal route. There was little possibility that the vanilla odor stimulated the taste receptors during the orthonasal stimulation because the odor stimuli were presented directly into the nasal cavity. Thus, we could show that the odor-induced taste enlancement is elicited by olfactory perception. These results also suggested that there is little functional difference between retronasal and orthonasal olfaction.

Administration, Oral↗

Contrast effect in evaluating palatability of beverages.

This study aimed to clarify the contextual effect in evaluation of the pleasantness of beverages. Participants were presented a test stimulus and were then asked to rate how much they liked it before and after presentation of a contextual stimulus. Specifically, after participants were exposed to a less palatable beverage, they evaluated the test beverage as being more palatable than when their judgment of a test drink occurred after presentation of a neutral or palatable beverage (a positive contrast effect). This contextual effect can be explained by the reasoning that participants were affectively adapted to the palatability (less palatable) of a less palatable stimulus after repeated exposure; thus, they evaluated the test stimulus as more palatable. This study suggests that the evaluated value of the contextual stimuli affects evaluation of the test stimulus. The authors also suggest that these context effects are probably found in everyday life.

Adult↗

Diagnostic and surgical strategies for intractable spontaneous intracranial hypotension. Case report.

The authors present the case of a 55-year-old man suffering from intractable spontaneous intracranial hypotension, in whom conservative treatment with 19 weeks of bed rest was not effective. In this period the patient twice underwent surgery for bilateral chronic subdural hematoma, a complication of spontaneous intracranial hypotension. Conventional radionuclide cisternography, magnetic resonance imaging, and computerized tomography myelography did not demonstrate cerebrospinal fluid (CSF) leakage. Repeated radionuclide cisternography with the patient in an upright position revealed leakage of the tracer at upper cervical levels. Computerized tomography myelography with breath holding also showed CSF leakage of the contrast medium bilaterally at upper cervical levels. The patient underwent surgery, and bilateral C-2 and C-3 spinal nerve root pouches were sealed off from the subarachnoid space with oxidized cellulose cotton and fibrin glue. Epiarachnoid spaces around the root sleeves were also sealed to ensure complete resolution of the CSF leakage. After the surgery, the patient was completely free of the disease. In the case of intractable persistent spontaneous intracranial hypotension, surgical treatment is preferable to long-term conservative management. To identify CSF leakage, radionuclide cisternography with the patient in the upright position is useful. When obvious leakage is encountered, surgical sealing of the lesion should be performed via a subarachnoid approach.

Cerebral Ventricles↗

[Effect of interferon therapy on hepatitis B virus related membranous nephropathy associated with focal segmental glomerulosclerosis].

We experienced a 24-year-old Japanese man, who was a hepatitis B virus carrier with nephrotic syndrome. Liver biopsy showed that he was suffering from chronic hepatitis (activity 2, fibrosis 2). Renal biopsy revealed membranous nephropathy(MN) with focal segmental glomerulosclerosis(FGS). Immunofluorescentic findings revealed the presence of HBe antigen along the glomerular capillaries as well as HBe antigenemia in circulation. Therefore, we diagnosed this case as HB virus-related membranous nephropathy associated with FGS lesions. He was treated with interferon(IFN) alpha-2b for over a month and angiotensin converting enzyme inhibitor. These therapies reduced urinary protein excretion from 4-6 g/day to 1-2 g/day, in accordance with a decrease in the titer of HBV DNA polymerase. The second renal biopsy revealed that the histological change from MN to membranoproliferative glomerulonephritis Type III after IFN therapy. These results suggest that IFN therapy might be effective for HB virus-related MN associated with FGS.

Adult↗

Enhancement of matrix metalloproteinase (MMP)-2 activity in gingival tissue and cultured fibroblasts from Down's syndrome patients.

OBJECTIVES: To identify one of the possible factors responsible for periodontal disease in Down's syndrome (trisomy 21) patients, we studied the enzyme activity and the mRNA expression pattern of matrix metalloproteinases (MMPs) of cultured gingival fibroblasts (GF) and fresh gingival tissues. MATERIALS AND METHODS: Gingival tissue was used as the cell source and was biopsied at the time of dental treatment from nine patients with Down's syndrome and nine non-Down's controls. GF were cultivated in serum-free media for analyses of their MMP activities at the transcription or the protein level. The MMP activities in the supernates were measured by gelatin impregnated zymography. Relative levels of MMP mRNA from the cultured GF or freshly isolated gingival tissues were determined using the reverse transcription polymerase chain reaction (RT-PCR). RESULT AND CONCLUSIONS: The production of the active type of MMP-2 in GF from Down's syndrome patients (D-GF) was found to be significantly higher (P < 0.05) than that of the control GF (C-GF) at the protein level. The mRNA expressions of membrane-type I MMP (MT1-MMP) and MMP-2 in D-GF were constitutively augmented when compared with those of C-GF. These findings suggest that specific increase of the active form of MMP-2 in D-GF may possibly be due to the concomitant expression of MT1-MMP in the cultured cells, and this could be related to the pathogenesis of gingivitis/periodontitis associated with Down's syndrome patients.

Adolescent↗

[Bilateral carotid stenting for radiation-induced arterial stenosis].

We report a case of bilateral radiation-induced internal carotid artery (ICA) stenosis treated with stenting. A 67-year-old man experienced transient left hemiparesis several times, and it was diagnosed as a bilateral ICA stenosis by magnetic resonance angiogram (MRA) and cervical ultrasound sonogram (US). Ten years before, the patient had received radiation therapy (66 Gy) and radical resection for a squamous cell carcinoma (SCC) in the right infrapharyngeal space. A cerebral angiogram showed bilateral severe ICA stenosis (right; 90%, left; 99%). We diagnosed this as radiation-induced ICA stenosis, and performed carotid angioplasty with a self-expanding stent. The post-operative course was uneventful and the patient was discharged without neurological deficits. Carotid endarterectomy (CEA) is difficult in the case of carotid artery stenosis due to radiation-induced arterial injury. Carotid stenting may be an alternative treatment for such a patient.

Aged↗

[Mannosidosis].

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Humans↗

[Sialidosis].

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Adolescent↗

[Stenting for proximal subclavian and brachiocephalic artery occlusion--preliminary results].

The authors report the initial results, between January 1998 and February 2001, of stenting utilizing the brachial approach in seven patients for total occlusions at the following locations: two right subclavian, one brachiocephalic, and five left subclavian arteries. All lesions were associated with subclavian steal syndrome. Indications for the treatment included ischemic symptoms in the affected arm (seven patients), and vertebrobasilar insufficiency (five patients). A total of eight stents were implanted in six occluded arteries, resulting in a 75% procedural success rate. Procedural complications encountered were two subintimal dissections by a 0.035-inch guide wire during recanalization, and one stent dislodgement with migration. There was no stroke, presumably because of the previously reported preventive effect of delayed reversal of a stealing vertebral artery. Follow-up over a mean duration of 11 months revealed no sign or symptom of recurrence in cases with initial technical success. The results of the current study, with a literature survey, indicated that percutaneous transluminal angioplasty with primary stent deployment in an occluded prevertebral segment of the subclavian or the brachiocephalic artery should be considered as an available choice for treatment. Further points, such as some remaining technical and clinical problems, will require more experience and consideration.

Adult↗

[A case of a persistent primitive proatlantal intersegmental artery with a ruptured basilar bifurcation aneurysm].

A case of persistent primitive proatlantal intersegmental artery (PPPIA) associated with a ruptured basilar bifurcation aneurysm was reported. A 44-year-old male with sudden headache was admitted to our hospital. CT scan revealed subarachnoid hemorrhage. Cerebral angiography revealed anomalous anastomosis between the internal carotid artery and the vertebral artery at the proatlantal region. This anastomosis branched off from the left internal carotid artery at the C4 level and joined the horizontal portion of the left vertebral artery. It was thought to be PPPIA. Angiography also revealed an aneurysm of the basilar bifurcation which was responsible for the patient's subarachnoid hemorrhage. The aneurysm was successfully treated by endovascular embolization with Guglielmi detachable coils in an acute stage, and resulted in good outcome. PPPIA with basilar bifurcation aneurysm has not been presented or reported in the literature to date. To our knowledge, this is the first report of such an association of vascular anomalies. The frequency of PPPIA combined with the intracranial aneurysm is relatively high, whereas the occurrence of PPPIA is extremely rare. Therefore, it was suggested that some congenital and/or hemodynamic factors changed by PPPIA may affect the pathogenesis of intracranial aneurysms.

Adult↗

[Problems involved in endovascular embolization of intracranial aneurysms with three-dimensional Guglielmi detachable coils].

We experienced nine cases of intracranial aneurysms which were treated with three-dimensional Guglielmi detachable coils (3D-GDC). 3D-GDC is useful in the construction of the initial frame for the embolization of aneurysms, but it also has certain disadvantages for achieving successful treatment. Nine patients with nine intracranial aneurysms were treated with 3D-GDC for initial framing from October, 1999 to September, 2000 at the National Cardio-Vascular Center, Japan. Angiographically complete and successful occlusion was performed in only three patients. Four patients developed parent artery stenosis due to small loops of the 3D-GDC protruding from the aneurysm. Two patients experienced incomplete occlusion because small loops of the 3D-GDC caused cells to form in the framing, and additional coils could not be inserted into some cells. 3D-GDC is useful as an initial framing coil, but we should be careful when placing additional coils into an aneurysm because we cannot predict the effect of the small loops of 3D-GDC on the embolization of aneurysms.

Aged↗

[A case of iatrogenic carotid artery dissection treated with radial artery graft].

A case of iatrogenic intracranial artery dissection is reported. A 52-year-old female developed severe headache and nausea. Brain CT showed diffuse subarachnoid hemorrhage. On admission, carotid angiography revealed an aneurysm in the right middle cerebral artery and the intact right internal carotid artery. The aneurysm was clipped successfully. Carotid angiography on day 7 revealed dissection in the right internal carotid artery. Repeated angiograms at 10 and 31 days showed progression of the carotid artery dissection. Findings of ECD-SPECT on day 31 (Balloon occlusion test) suggested low perfusion of the right internal carotid artery territory. The patient underwent surgical reconstruction of the right internal carotid artery using a radial artery. She presented with right abducens nerve palsy three days after the radial artery graft. The patency of the radial artery graft was proved by the post-operative angiography. Internal carotid artery dissection may occur spontaneously or as a result of trauma. An iatrogenic dissection is an uncommon complication of cerebral angiography. There are no evidence-based guidelines for the treatment although anticoagulation therapy is most commonly used. The present case emphasizes the usefulness of radial artery graft for traumatic carotid artery dissection.

Carotid Artery, Internal↗

Role of the diurnal variation of urinary pH and urinary calcium in urolithiasis: a study in outpatients.

BACKGROUND: We previously reported that the urinary excretion of calcium and the diurnal variation of urinary pH were important for stone formation in hospitalized inpatients with hospital standard diet. Because almost all urinary stones are formed in outpatients with ambulatory free diet, it is essential to investigate these factors in outpatients. METHODS: We examined the urinary excretion of calcium, oxalate, uric acid, phosphate and magnesium in 96 male outpatients and 142 male inpatients. We also studied the relationship between the stone composition and the diurnal variation of urinary pH in 32 male outpatients (five uric acid stones (UA), 13 pure calcium oxalate stones (CaOX) and 14 mixed calcium oxalate and calcium phosphate stones (CaOX-CaP)) and 53 male inpatients (nine UA, 15 CaOX and 29 CaOX-CaP). RESULTS: There was a significant difference in the urinary excretion of calcium among outpatients with UA, CaOX and CaOX-CaP (133 +/- 96 vs 219 +/- 97 vs 268 +/- 102 mg per day, P < 0.05). In outpatients with UA, urinary pH was constantly low throughout the entire day. In contrast, outpatients with CaOX and those with CaOX-CaP had diurnal variation of urinary pH that was low in the early morning, followed by elevation in the daytime and was lowered in the night. The pHs in the early morning, afternoon and night were significantly higher in outpatients with CaOX-CaP than in those with CaOX. CONCLUSION: The diurnal variation of urinary pH and the urinary calcium are important for stone formation.

Adult↗