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N Yoshioka

Publications and source records attributed to N Yoshioka.

At least 55 records · Page 3Linked to original sources
PubMed1998

Platelet-activating factor is a key mediator of pulmonary vasoconstriction and bronchoconstriction after antigen challenge in the perfused sensitized rabbit lung.

Exposure of sensitized perfused rabbit lungs to human O-N type erythrocytes leads to pulmonary vasoconstriction and bronchoconstriction. To investigate whether platelet-activating factor (PAF) is a mediator of pulmonary vasoconstrictive and bronchoconstrictive responses after antigen challenge, we administered antigenic erythrocytes after the administration of PAF antagonist (.1 mg/kg; CV6209). Pulmonary arterial and airway pressures significantly increased after antigen challenge in the sensitized rabbit lungs, but not in the nonsensitized rabbit lungs. CV6209 significantly inhibited these pulmonary vasoconstrictive and bronchoconstrictive responses after antigen challenge. We concluded that PAF, at least in part, plays an important role in pulmonary vasoconstriction and bronchoconstriction after antigen challenge in rabbits.

Animals↗
PubMed1998

Isolation of an Arabidopsis thaliana mutant in which the multiplication of both cucumber mosaic virus and turnip crinkle virus is affected.

During the systemic infection of plants by viruses, host factors play an important role in supporting virus multiplication. To identify and characterize the host factors involved in this process, we isolated an Arabidopsis thaliana mutant named RB663, in which accumulation of the coat protein (CP) of cucumber mosaic virus (CMV) in upper uninoculated leaves was delayed. Genetic analyses suggested that the phenotype of delayed accumulation of CMV CP in RB663 plants was controlled by a monogenic, recessive mutation designated cum2-1, which is located on chromosome III and is distinct from the previously characterized cum1 mutation. Multiplication of CMV was delayed in inoculated leaves of RB663 plants, whereas the multiplication in RB663 protoplasts was similar to that in wild-type protoplasts. This suggests that the cum2-1 mutation affects the cell-to-cell movement of CMV rather than CMV replication within a single cell. In RB663 plants, the multiplication of turnip crinkle virus (TCV) was also delayed but that of tobacco mosaic virus was not affected. As observed with CMV, the multiplication of TCV was normal in protoplasts and delayed in inoculated leaves of RB663 plants compared to that in wild-type plants. Furthermore, the phenotype of delayed TCV multiplication cosegregated with the cum2-1 mutation as far as we examined. Therefore, the cum2-1 mutation is likely to affect the cell-to-cell movement of both CMV and TCV, implying a common aspect to the mechanisms of cell-to-cell movement in these two distinct viruses.

Arabidopsis↗
PubMed1998

Avulsion injury of cervical nerve roots: enhanced intradural nerve roots at MR imaging.

PURPOSE: To study the magnetic resonance (MR) imaging features of intradural nerve roots in avulsion injury of the cervical nerve roots. MATERIALS AND METHODS: Presurgical gadolinium-enhanced MR imaging was performed in 27 consecutive patients. The images were evaluated for enhancement of the intradural nerve roots and enhancement of the spinal cord surface at the root entry zone ("root stump" enhancement) by two radiologists, who were blinded to the clinical information. Intradural nerve roots were classified as enhanced, normal, or not visible. Root stumps were classified as enhanced or normal. The results were compared with the results of nerve root continuity studies (exploratory surgery with intraoperative recording of somatosensory evoked potentials or neurologic examination). RESULTS: At the 250 nerve levels (500 nerve roots) studied, 12 enhanced nerve roots and 42 enhanced root stumps were found. Seven enhanced nerve roots and 38 enhanced root stumps were related to preganglionic injury. Results of the kappa test for interobserver concordance on findings of intradural nerve roots and root stumps were 0.55 and 0.93, respectively. CONCLUSION: Although visualization of nerve roots is a problem, enhanced MR imaging is a noninvasive means of obtaining anatomic information and unique physiologic information on injured intradural nerve roots.

Adolescent↗
PubMed1998

Cerebral revascularization using muscle free flap for ischemic cerebrovascular disease in adult patients.

The efficacy of encephalo-myo-synangiosis (EMS) using muscle free flap was evaluated for the treatment of ischemic cerebrovascular disease in adult patients. Three patients with adult moyamoya disease and three patients with atherosclerotic ischemic cerebrovascular disease were treated. EMS used four latissimus dorsi muscles and two serratus anterior muscles. Postoperative selective angiography showed collateral circulation from the transferred muscle to the brain in four of the six patients. The other two patients showed patent nutrient artery of the transferred muscle flap. Cerebral blood flow study disclosed postoperative improvement of perfusion reserve capacity in all sides. One patient suffered a perioperative stroke by hemoconcentration due to poor control of diabetes mellitus. The mean follow-up period was 23 months. EMS using muscle free flap is a possible procedure in selected patients with impaired cerebral perfusion reserve capacity due to multiple stenosis or occlusion of cerebral arteries including moyamoya disease or who required cerebral blood flow augmentation in the anterior and/or posterior cerebral artery territories due to internal carotid artery occlusion.

Adult↗
PubMed1998

[Epidemiological study of suicide in Japan--is it possible to reduce committing suicide?].

It is reported that the annual number of suicides in Japan is more than 20,000, which is as twice as the number of death by traffic accidents. Nevertheless, few protective activities have been developed by government or society. This paper introduces the actual states of suicide in the past few years in Japan, expecting to start a movement for reducing suicidal number by government, society and family in Japan. The number of suicide was less than 15,000 in the late 1960s, but it increased to more than 20,000 in 1970s, which has not been reduced up to the present and the highest number 256,000 was recorded in 1986. The Ministry of Welfare reports that the prefectures showing higher rate of suicide have been Akita, Iwate and Niigata, whose suicide rates are 10 points higher than that of the national average. On the other hand, the prefectures such as Nara, Shiga, Shizuoka and Kanagawa have shown lower rate of suicide. In all the prefectures, the number of males is constantly much larger than that of females and, furthermore, the rate of suicide in the male and female aged group (over 65 years old) is much higher than that of the under-64-year-old group. As a background of suicide, psychiatric disorders account for 30-50% of all suicides in the younger and prime generations, but as a motive of suicide the pain of sickness amounts to 60-70% in the aged group. It is suspected by our epidemiological investigations that the pain of sickness is not a true motive for committing suicide. Sickness usually accompanies anxiety, pessimistic view of life, loss of an important part in his/her family and economical uneasiness. The most frequently used method for committing suicide in male and female especially in the aged group is hanging, and next to this are inhalation of car exhaust, drowning oneself and taking poisons. Firearms are quite rarely used in Japan. Aging, mental disorders and genetic factors are considered to be risk factors for suicide attempt. It should be pointed out that betterment of home life, mental independence, death education and forced intervention by psychiatrists are required to reduce the number of suicides.

Age Factors↗
PubMed1998

Velocity-coded color MR angiography.

We developed a method of velocity-coded color MR angiography using a color code from the data obtained from velocity-phase images of phase-contrast MR angiography in order to add flow direction information to MR angiograms. Phase-contrast MR angiography with reconstruction of velocity-phase images was performed in 30 patients. Two projection images from velocity-phase images of each phase-contrast MR angiogram were obtained and assigned color according to flow direction. We then superimposed the two color images onto the maximum intensity projection image of the MR angiogram. The velocity-coded color MR angiogram clearly showed flow direction from the data on the phase-contrast MR angiogram of the neck. Veins were readily distinguishable from arteries, and flow changes, such as a subclavian steal, were also identified.

Blood Flow Velocity↗
PubMed1997

Emergence of osteoblast-like cells in a neoplastic human salivary cancer cell line after treatment with 22-oxa-1alpha, 25-dihydroxyvitamin D3.

A neoplastic clonal cell line, which was prepared by 5-azacytidine treatment of a neoplastic human salivary intercalated duct cell line, was cultivated in the presence of 22-oxa-1alpha, 25-dihydroxyvitamin D3 and 3 mM beta-glycerophosphate. Major alterations, such as expression of type I collagen and alkaline phosphatase as well as of human osteopontin and osteonectin, were observed in these cells with a phenotype similar to osteoblasts. In addition, formation of bone nodule was observed in the cultured cells. The tumors produced by transplantation into nude mice of the clonal cells were treated with 22-oxa-1alpha, 25-dihydroxyvitamin D3 and examined for tumor growth and morphology. Consequently, growth of the treated tumor was significantly suppressed. Moreover, it was found that bone formation was induced in the treated tumor, in which the tumor cells around bone formation expressed human osteopontin and osteonectin mRNA as could be detected by in situ hybridization. The above findings indicate that the emergence of osteoblast-like cells in the human salivary cancer cells occurs in the presence of 22-oxa-1alpha, 25-dihydroxyvitamin D3 and beta-glycerophosphate.

Animals↗
PubMed1997

Flow characteristics of soft-tissue vascular anomalies evaluated by direct puncture scintigraphy.

Soft-tissue vascular anomalies such as haemangioma and vascular malformation are treated by surgical resection, arterial embolization or sclerotherapy. Because the effect of sclerotherapy, i.e. the percutaneous injection of sclerosing agents, depends on intralesional haemodynamics, estimation of flow characteristics of soft-tissue vascular anomalies is essential when determining appropriate patient management. However, lesions are at present divided into only two groups: high flow and low flow. We have developed a new method, direct puncture scintigraphy, to evaluate in detail the haemodynamics of vascular anomalies under conditions simulating sclerotherapy. Twenty-six soft-tissue vascular anomalies in 21 patients were studied. After 30 MBq of technetium-99m Sn colloid was injected percutaneously into the intravascular space of the lesion, dynamic imaging was performed for 5 min. A time-activity curve for the lesion was generated, with the infiltrated activity on injection subtracted. A monoexponential curve was fitted to the declining phase of the time-activity curve, and mean vascular transit time (MTT) was obtained. The lesions were classified into high-flow and low-flow lesions based on radionuclide angiography with intravenous injection of 99mTc-labelled red blood cells, and estimates of MTT in the two groups were compared. The imaging procedures were carried out with no major complications, and broad intralesional diffusion of 99mTc-Sn colloid was achieved in most lesions. The high-flow lesions (six lesions) had a short MTT, ranging from 1.6 to 3.4 s, while the low-flow lesions (20 lesions) had a longer MTT, with no overlap between the groups. MTT showed a wide range in low-flow lesions: it was less than 30 s in six lesions and more than 10 min in five other lesions. Direct puncture scintigraphy provides a quantitative indicator of the flow characteristics of soft-tissue vascular anomalies, and may aid in determining treatment strategies for patients with vascular anomalies.

Adolescent↗
PubMed1997

Technical report: coaxial catheter: a new technique for sequential spiral CT during arterial portography and hepatic arteriography.

PURPOSE: To evaluate a coaxial catheter method to sequentially acquire spiral-computed tomography (CT) during arterial portography (CTAP) and hepatic arteriography (CTA) at a single transfer. PATIENTS AND METHODS: Sixteen patients with malignant hepatic tumours (12 patients with hepatocellular carcinoma, four with metastases) were studied using spiral CT. Depending upon the vascular anatomy revealed by conventional coeliac and superior mesenteric arteriography, an outer and inner catheter were selectively placed to perform CTA and CTAP, respectively. CTAP images were obtained first, while injecting contrast material through an inner catheter followed by the acquisition of the CTA images during injection through an outer catheter. In three patients, the resected specimens were available for comparison with the imaging findings. RESULTS: In 12 patients with standard hepatic arterial anatomy, high quality images of CTAP and CTA were obtained. More lesions were detected by the combination of CTAP and CTA than by CTAP or CTA alone in five patients. In one patient with breast carcinoma and a left hepatic artery arising from the left gastric artery, numerous hepatic metastases were delineated on both sets of images. In three patients with replaced or accessory right hepatic arteries, evaluation of the whole liver was difficult on CTA. These procedures were well tolerated by all 16 patients and no complication or technical failure was experienced. CONCLUSION: These preliminary data support this new technique as a promising method of performing CTA and CTAP in patients with standard hepatic arterial anatomy with a single catheter insertion.

Aged↗
PubMed1997

Cerebral revascularization by omental free flap using contralateral superficial temporal vessels as recipient vessels: case report.

BACKGROUND: Although the most common technique of cerebral revascularization is superficial temporal artery to middle cerebral artery bypass, we occasionally encounter a situation in which the ipsilateral superficial temporal artery is not available. Treatment may require several techniques including long vein graft bypass. METHODS: A 54-year-old man experienced transient ischemic attacks, and cerebral angiography revealed occlusion of the right common carotid artery. Cerebral blood flow study revealed reduced perfusion reserve capacity of the right cerebral hemisphere. We applied an omental free flap to the brain surface using the contralateral superficial temporal vessels as recipient vessels. RESULTS: Cerebral blood flow study revealed improvement of perfusion reserve capacity. Cerebral angiography revealed good collateral circulation from the omentum to the brain. The patient has not experienced a transient ischemic attack, following additional ligation of the occipital artery 13 months after the first operation. CONCLUSIONS: Because an omental flap has a long pedicle and its circulation can be monitored easily, this method is safe and as effective as a long bypass graft in a patient such as ours in whom the ipsilateral superficial temporal artery is not available for anastomoses.

Anastomosis, Surgical↗
PubMed1997

First case of surgical treatment of Farber's disease.

Farber's disease (Farber's lipogranulomatosis), which is inherited as an autosomal recessive trait, was first reported by Farber in 1952. We report a case of Farber's disease in a 12-year-old female. Her younger brother was affected with Farber's disease and died of it at 2 years of age. When she first presented, our patient's main clinical features were a shrill voice; subcutaneous nodules; contracture of the joints throughout the body; and granulomas of the oral cavity, the pharynx, and the upper and lower eyelids. Serial radiographs disclosed deformation of the joints throughout the body. Due to the granulomas in her oral cavity, she could take little food orally and therefore was malnourished. We performed a granulectomy under general anesthesia, and her difficulty with feeding and upper airway obstruction improved. There is no specific treatment for Farber's disease, and most patients reported have died by 2 years of age. This is the first reported patient with Farber's disease who has been surgically treated.

Ceramides↗
PubMed1997

Arterialized occipitoparietal osteocutaneous flap.

We treated a case of postoperative osteomyelitis and epidural abscess in the left temporal and parietal region. The scalp and skull defect following debridement was reconstructed immediately with an arterialized occipitoparietal osteocutaneous flap that was supplied proximally by the occipital artery and distally by the superficial temporal artery. This method is one of the alternative methods for small to moderately sized skull and scalp defects in the temporal, parietal, and occipital areas without available superficial temporal artery.

Female↗
PubMed1997

Indonesian medicinal plants. XXI. Inhibitors of Na+/H+ exchanger from the bark of Erythrina variegata and the roots of Maclura cochinchinensis.

Through bioassay-guided separation of the methanol extracts of Indonesian medicinal plants, three inhibitors of the Na+/H+ exchange system, erythrinin B (2), euchrenone b10 (3), and 1,3,5-trihydroxy-4-(3-methylbut-2-enyl)xanthen-9-one (4), were isolated from the bark of Erythrina variegata (Fabaceae) (for 2) and the roots of Maclura cochinchinensis (Moraceae) (for 2, 3, 4). Compounds 2, 3, and 4 significantly inhibited the Na+/H+ exchange system of arterial smooth muscle cells, with minimum inhibitory concentrations of 1.25, 1.25, and 10 micrograms/ml, respectively. Three new prenylated xanthones named isocudraniaxanthones B (5) and A (7) and isoalvaxanthone (9) were also isolated from M. cochinchinensis and the chemical structures were elucidated on the bases of their chemical and physicochemical properties.

Animals↗
PubMed1997

Cerebral revascularization using latissimus dorsi muscle free flap transfer--technical note.

A method for cerebral revascularization using latissimus dorsi muscle free flap transfer is described. Latissimus dorsi muscle is harvested with thoracodorsal vessels after completion of craniotomy and exposure of superficial temporal vessels. The size of muscle belly which is harvested is dependent on the area where the revascularization is necessary. Microvascular anastomoses of superficial temporal vessels and thoracodorsal vessels are performed in end-to-end fashion. A 31-year-old male patient with moyamoya syndrome was treated by this method. Postoperative angiography demonstrated successful revascularization in the affected hemisphere, with improved perfusion reserve capacity shown by cerebral blood flow study. This type of encephalo-myo-synangiosis (with free muscle flap) is a possible method when vascular reconstruction of an extensive ischemic area which involves anterior and posterior cerebral artery territories is needed in a patient with moyamoya disease or other similar ischemic conditions.

Adult↗
PubMed1996

A case of aconitine poisoning with analysis of aconitine alkaloids by GC/SIM.

Described here is a fatal case of accidental aconitine poisoning following the ingestion of aconite, Torikabuto, mistaken for an edible grass, Momijigasa. A 61-year-old man developed symptoms of nausea, diarrhea, and discomfort of the body about 2 h after the ingestion and was taken to an emergency room. Resuscitation and antiarrhythmic drugs were ineffective, and ventricular tachycardia and fibrillation developed and lasted for 6 h. He was transferred to a coronary care unit and complete sinus rhythm was obtained on an electrocardiogram 30 h after his admission. The patient fell into a coma and died of brain edema diagnosed by CT on the 6th day. Consent for autopsy was denied by the family but was given for gas chromatography/selected ion monitoring (GC/SIM) to analyze the toxicity of aconitine alkaloids in the blood and the urine. Only a faint amount of jesaconitine was detected, while aconitine, mesaconitine and hypaconitine were not detectable in the blood 24 h after ingestion. On the other hand, aconitine and its related alkaloids such as mesaconitine, jesaconitine, and hypaconitine were clearly detected in the urine.

Aconitine↗
PubMed1996

Isolation of a novel gene down-regulated by v-src.

We have isolated a novel gene which was expressed in normal rat cells, but completely suppressed in cells transformed by v-src. The molecularly cloned cDNA was about 1.8 kb in size, containing an open reading frame composed of 464 amino acid residues. DNA sequence analysis showed that there was no corresponding gene in the data bases. Besides the suppression of gene expression in the v-src transformed cells, its expression was also strongly suppressed in cells transformed by other oncogenes such as v-abl, v-fps, v-mos, v-sis, v-K-ras, and polyomavirus middle T, but not affected in cells transformed by human papillomavirus type 16 E6E7 and polyomavirus large T. We named the gene drs for a gene down-regulated by v-src.

Amino Acid Sequence↗