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Biomedical subjects

Y Higa

Publications and source records attributed to Y Higa.

At least 19 recordsLinked to original sources
PubMed2001

Evidence for a new sibling species of Anopheles minimus from the Ryukyu Archipelago, Japan.

The Anopheles minimus complex is known to comprise at least 2 sibling species (A and C) in Thailand and Vietnam. This study investigated the specific status of An. minimus on Ishigaki Island, the Ryukyu Archipelago, Japan using morphological and genetic analyses. Morphological studies revealed that almost all (99.5%) of the adult mosquitoes are characterized by the humeral pale spot on the costa of their wings, a character that partially differentiates species A and C elsewhere. A high frequency (81.4%) have a pale fringe spot at the tip of vein 1A, a character rarely observed in other An. minimus populations. Significant seasonal variation in the size of wild An. minimus mosquitoes on the island was observed, with the largest size in the winter. Scanning micrographs of the cibarial armature of females from Ishigaki Island revealed that over 90% had cone filaments clearly differing in shape from those of species A or C. The Giemsa-stained metaphase karyotypes of larval brain cells were somewhat similar to those of species A, with a few exceptions, but were very different from those reported for species C. Crossing experiments between species A (CM strain) from Thailand and the progeny of An. minimus from Ishigaki Island (ISG strain) revealed postzygotic genetic incompatibility, although no prezygotic isolation. Hybrid progeny were only obtained from CM female x ISG male. F2 hybrid progeny were not obtained, since the hybrid males were sterile or almost sterile with atrophied testes or abnormal spermatozoa, although the polytene chromosomes of hybrid larvae showed synapsis. The hybrid females backcrossed with either CM or ISG males laid eggs with significantly lowered fertility and viability. The sequence for the D3 region of the 28S gene of ribosomal DNA of the ISG strain differed from those of species A and C. In addition, sequence data from Vietnamese mosquitoes suggest that the An. minimus complex may contain additional species. The morphological, cytogenetic, molecular, and hybridization evidence together suggest the existence of another sibling species of the An. minimus complex on Ishigaki Island, which is provisionally designated An. minimus species E.

Animals↗
PubMed2001

Ambulatory monitoring of behavior in daily life by accelerometers set at both-near-sides of the joint.

In this paper we examined a new joint motion monitoring method by use of accelerometers to monitor subjects' detailed motion in daily activities. In this method two accelerometers are set at as near points of both sides around the joint as possible. The difference between these two sensors' outputs mainly depend on the joint angle because the centrifugal and the turning acceleration occurred by the rotation around the joint can be neglected. In the experiments we tried to monitor various subject's behaviors of his upper and lower extremities and whole body motion, and could show this method is useful for the ambulatory monitoring of behavior in daily life.

Acceleration↗
PubMed2000

Studies on thyroid function in rats subjected to repeated oral administration with kojic acid.

To elucidate the effects of kojic acid on thyroid function, the compound was given orally to male rats for 4 weeks at 0, 4, 15, 62.5, 250 and 1,000 mg/kg. In 1,000 mg/kg treatment of kojic acid, the rats showed a slight decrease in motility, inhibition of body weight gain, and a decrease in food consumption. An increase in thyroid weight and a morphological change, i.e., hypertrophy of epithelial cells of the thyroid gland follicles, were observed after 1 week of administration. In addition, the uptake of radioactive iodine from blood into the thyroid gland was enhanced and the TCA-precipitable radioactive iodine in the thyroid gland increased in those rats. However, the rates of the iodination in the thyroid gland did not change during the experiment period. Although serum T4 concentration was low in the rats treated with 1,000 mg/kg kojic acid, it was not observed in any changes in TSH concentration. None of these changes were found in the other groups. These observations suggest that massive administration of kojic acid may decrease blood T4 concentration and that thyroid function may be enhanced compensatorily. On the other hand, the absorption of kojic acid was rapid as manifested by the Tmax of blood concentrations of radioactivity, which was as short as 1.0 +/- 0.0 hr, and the t1/2 was 4.8 +/- 0.3 hr. Blood concentrations of radioactivity disappeared nearly completely at 24 hr after administration. This result indicates that the toxic effect observed on the thyroid gland treated with only the largest dosage of kojic acid may depend on a fast decrease following a transient increase of concentration of the compound in the blood.

Animals↗
PubMed1997

[Positive seroconversion syphilis in a patient with acute lymphocytic leukemia after allogeneic bone marrow transplantation].

An acute lymphocytic leukemia patient underwent allogeneic bone marrow transplantation (BMT) from a sibling who was serologically positive for syphilis. After the donor was administered antibiotic therapy, the titration of treponema pallidum hemagglutination (TPHA) decreased from x1260 to x320. Thereafter, the graft consisting of mononuclear cells was transplanted. TPHA of the recipient turned positive on day +63, but became negative 1.5 years after BMT. Although the cause of the seroconversion of TPHA seemed to be the contamination of treponema to the graft, the adoptive transfer could not be ruled out as an another possible cause.

Adult↗
PubMed1995

Astrocytoma linked to familial ataxia-telangiectasia.

A 7-year and 11 month-old girl with cerebellar astrocytoma linked to familial ataxia-telangiectasia (AT) is presented. She was born as the 7th girl of a woman with aortic arch syndrome. Two elder sisters of the patient have ataxia telangiectasia. She had immunodeficiency, and cerebellar ataxia, but had no oculocutaneous telangiectasia. The risk of cancer developing in AT patients is about 1,200 times greater than that in age-matched controls. With regard to central nervous system tumours, seven primary tumours have been reported, such as 3 cases of medulloblastoma and 4 cases of glioma. Members of AT families who were under the age of 45 had a risk of dying of a malignant neoplasm five times greater than in the general population. However, there were no reports of glioma in AT families. In this case, it is suggested that IgA deficiency linked to familial AT may have contributed to the development of astrocytoma.

Astrocytoma↗
PubMed1995

Aortic dissection after aortic valve replacement. Report of a case with an aortocameral fistula.

A 58-year-old Japanese woman who had a history of aortic valve replacement for congenital bicuspid valve, was admitted for investigation of facial edema and of pulselessness of the right leg. Physical examination disclosed the patient suffering from a superior vena cava syndrome. On auscultation, a continuous murmur was heard at the left lower sternal border. Computed tomographic scans revealed aortic dissection extending from the ascending aorta to the bifurcation. Echocardiography showed an intimal flap in the dilated ascending aorta, but not abnormal blood flow from the aorta to the right atrium was detected. Cardiac catheterization and aortography, however, allowed a correct diagnosis of aortic dissection with fistula to the right atrium and with obstruction of the right common iliac artery. The patient received emergency aortic root replacement and reconstruction of the coronary arteries and then recovered uneventfully.

Aortic Dissection↗
PubMed1995

Total aortic replacement in a patient with mega aorta syndrome--a case report.

A 64-year-old woman without manifestations of Marfan syndrome was referred for the close investigation of a pulsatile abdominal mass. Computed tomographic scans and magnetic resonance images revealed aneurysmal dilatation of the entire aorta, including the ascending aorta and extending to the bifurcation of the aorta, as well as tortuousness of the thoracoabdominal and abdominal aorta. Digital subtraction angiography also showed aneurysmal dilatation of the entire aorta and trivial aortic regurgitation. However, aortic annular dilatation was not found by echocardiography or aortography. The entire aorta was replaced in two stages. First, graft replacement of the ascending aorta, except for the sinus segment, and the aortic arch was performed using an elephant trunk technique under hypothermic cardiopulmonary bypass with selective cerebral perfusion. Twelve weeks later, the remaining aorta, including the descending aorta and extending to the common iliac artery on the right side, and to the common femoral artery on the left side, was replaced with a partial cardiopulmonary bypass using femoral artery and vein cannulation. We believe that patients with mega aorta syndrome are best treated by total aortic replacement. The results in the present case indicate that the elephant trunk technique is useful for extensive aortic replacement in stages, and greatly facilitates the second stage operative procedures.

Aorta↗
PubMed1994

Surgical treatment for acute aortic dissection and coexistent degenerative aortic aneurysm. Report of three cases.

Acute aortic dissection occurring in an aorta previously afflicted with degenerative, atherosclerotic is unusual. We report three cases with acute aortic dissection (DeBakey type III-b) occurring in an aorta which had a preexistent degenerative aortic aneurysm. Two of the three patients had acute aortic dissection originating from the distal end of the degenerative aneurysm, and the remaining one had the acute aortic dissection and degenerative aneurysm at different segments of the aorta. Since the risk of rupture is likely to be much higher in the patients with coexistence of acute aortic dissection and degenerative aortic aneurysm, compared with patients with DeBakey type III acute aortic dissection alone, we believe that a prompt and aggressive surgical approach is essential to prevent rupture, and that digital subtraction angiography (DSA) is more helpful in making a correct diagnosis and in helping to decide surgical procedures and supportive methods than other noninvasive diagnostic procedures.

Acute Disease↗
PubMed1993

Obstruction of the St. Jude Medical valve--diagnostic and therapeutic values of cineradiography.

Between 1984, and 1992, we observed 8 patients with an obstructed St. Jude Medical (SJM) valve. Of these, 1 had an obstructed SJM valve in the aortic position, 3 in the mitral position, and 4 in the tricuspid position. Diagnosis of obstruction of the SJM valve was made by cineradiography combined with echocardiography in all 8 patients. Restriction or absence of movement of the leaflet of the SJM valve was observed by cineradiography in all of the 8 patients. Normal range of leaflet mobility of the SJM valve was measured by conventional cineradiography in 70 patients with a normal SJM valve, and the results were compared with the leaflet mobility obtained from the 8 patients with an obstructed SJM valve. In this study, leaflet function in the obstructed SJM valve was strikingly abnormal, with both opening and closing angles, and leaflet motion clearly outside the normal range. Of the 8 patients, 4 underwent urgent prosthetic valve replacements after cineradiography and echocardiography were carried out. Thrombolysis using urokinase was performed in 4 patients, and this treatment was successful in 1 patient. Efficacy of thrombolytic therapy was evaluated by repeat cineradiography. Three of the 4 patients who received thrombolysis showed no significant improvement of leaflet mobility after at least 72 hours of thrombolytic therapy, and finally required surgical correction for the obstructed SJM valve. We believe that cineradiography combined with echocardiography is the optimal method for the diagnosis of obstruction of the SJM valve, and to follow the effect of thrombolytic therapy on prosthetic valve function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Human recombinant interleukin-1 beta-mediated growth inhibition of cultured malignant glioma cells.

The effect of human recombinant interleukin-1 beta (hrIL-1 beta) on tumor growth was studied in eight glioma cell lines. hrIL-1 beta inhibited growth in all cell lines, but to varying extents. Two cell lines were suppressed by 0.5 ng/ml hrIL-1 beta, and three cell lines required 20 ng/ml. hrIL-1 beta also induced morphological changes and increased F-actin contents. hrIL-1 beta-treated cells demonstrated multipolar shapes and numerous processes with a greater number of cell-cell contacts 24 hours after treatment. Fluorescence microscopy revealed that these processes contained a large amount of polymerized F-actin. These results suggest that hrIL-1 beta-mediated growth inhibition may be related to the differentiation of glioma cells.

Brain Neoplasms↗
PubMed1993

[Partial brachiocephalic perfusion in aortic arch replacement].

Twenty patients with aneurysm or dissection of the aortic arch underwent surgical treatment using partial brachiocephalic perfusion (PBP). The right subclavian artery (SA) and common femoral artery were separately cannulated and perfused by individual pump heads. The flow to SA was 4.5-11 (9.9 +/- 1.4) ml/min/kg. The mean distal stump pressure of the left superficial temporal arteries before beginning the CPB were 36-64 (50.6 +/- 8.3) mmHg. The rectal temperature during PBP was maintained at 20.1-25.0 degrees C. The PBP time ranged 32 to 157 min. We studied the oxygen saturation of left internal jugular vein (SjO2) and cerebral circulatory index (CCI) during the PBP. SjO2 ranged from 72.9 to 99.4% and CCI were maintained at more than twice the CCI measured before beginning the CPB. We applied this simplified method (PBP) to the 20 patients with aortic aneurysms. No neurological complication were seen in these 19 patients without one patient. These clinical studies suggest that the PBP under hypothermic CPB is a safe and reliable method of cerebral protection for replacement of the aortic arch.

Adult↗
PubMed1992

Lymphocytic adenohypophysitis with sudden onset of diabetes insipidus in menopausal female--case report.

A rare case of a postmenopausal (60-year-old) female with lymphocytic adenohypophysitis manifesting as a sudden onset of diabetes insipidus is reported. Magnetic resonance imaging with gadolinium-diethylene-triaminepentaacetic acid enhancement showed a spherical lesion, approximately 1 cm in diameter, in the sella turcica and a thickened, deviated pituitary stalk. The abnormal tissue was totally removed. Histological examination showed marked infiltration of lymphocytes and plasma cells. Postoperatively, the pituitary stalk became normal. Preoperative differentiation of lymphocytic adenohypophysitis from pituitary adenoma is extremely difficult, and biopsy is essential.

Adenoma↗
PubMed1992

Analysis of retained ventricular shunt catheters.

To identify the causes of ventricular shunt catheter retention, 42 shunt removals in 28 patients in our neurosurgical clinic from 1982 to 1991 were analyzed. The mean patient age was 13.8 years (2 mos-78 yrs), and mean shunt duration was 20.1 months (0.5-94 mos). There were nine retained ventricular catheters, including five with obstruction of the ventricular catheter. Shunt duration was significantly longer compared with the unretained group. Three retained ventricular catheters were stained by HE for histological examination. Light microscopy showed the inner lumen of catheters filled with granulomatous connective tissue and reactive glial tissue, and giant cell reaction to silicone material. Scanning electron microscopy of two catheters found peeling on the inner surface of the catheter, evidence of aging of the material. Granulomatous connective tissue and glial tissue reaction to aged silicone are suggested as the cause of catheter retention.

Adolescent↗
PubMed1992

[The motility of IL-2 activated lymphocytes into malignant glioma].

The effects of glioma culture supernatant (GCS) and interleukin-2(IL-2) on the motility of autologous stimulated lymphocytes (ASL) were studied by using collagen gel system, chemotaxic chamber system and flow cytometric analysis. GCS inhibited the migration of ASL into collagen gel. It enhanced the ASL motility and the expression of CD 26 antigen on the cell surface. IL-2 inhibited the migration of ASL into collagen gel and had no influence on the motility of ASL, but enhanced the expression of CD 26 antigen. On the other hand, a clinical glioma specimen showed limited depth of ASL migration when injected into the tumor cavity in addition to the formation of fibrin like membrane on its surface and a layer of degenerated ASL under it. To make ASL therapy more effective to malignant glioma, the following measures should be recommended; 1) inject adequate volume of IL-2 into tumor cavity, 2) reduce the frequency of ASL administration, 3) wash out of glioma secreting factors, degenerated ASL and glioma cells in addition to reduce the volume of tumor tissue.

Cell Movement↗
PubMed1992

[Arterial to end-tidal carbon dioxide difference during laparoscopy].

Arterial as well as end-tidal PCO2 (PaCO2, PetCO2), and arterial to end-tidal PCO2 difference (P(a-ET)CO2) were studied in 16 ASA-I patients anesthetized for laparoscopy under controlled ventilation. Using constant ventilation throughout the procedure, PaCO2 and PetCO2 increased significantly (P less than 0.01) to the maximum level (about 10 mmHg above the control level) within 22 min after CO2 insufflation, along with significant increase in mean arterial pressure and heart rate. There was a statistically significant correlation between PaCO2 and PetCO2 at the time of control (before surgery), at the time of maximum PetCO2 and 30 to 60 min after CO2 insufflation (P less than 0.01). Although mean P(a-ET)CO2 remained relatively constant during the procedure, a statistically significant correlation between PaCO2 and P(a-ET)CO2 was found at the time of maximum PetCO2 after CO2 insufflation (r = 0.71, P less than 0.01). These results suggest that when PvCO2 is increasing by CO2 insufflation, P(a-ET)CO2 depend on relative ventilation efficacy.

Adult↗
PubMed1991

Treatment of metastatic brain tumor from esophageal carcinoma--report of four cases.

Metastasis to the brain from esophageal carcinoma is rare. Recently we had four cases, all treated by tumor removal. Three received postoperative whole or local brain irradiation. Anticancer pellets were implanted in two. The postoperative 1-year survival rate was 37.5%, which suggests the prognosis is not worse than for other metastatic brain tumors.

Aged↗