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Biomedical subjects

S Tsunoda

Publications and source records attributed to S Tsunoda.

At least 217 records · Page 12Linked to original sources
PubMed1989

[The effect of neodymium yttrium aluminum garment laser on the cerebral blood vessel and blood brain barrier].

The effect of the laser energy to the cerebral vascular reactivity and the blood brain barrier. A Nd:YAG laser with 20 watt impacts of 0.5, 1.0, 2.5 and 5.0 seconds duration time were irradiated through the cranial window made at the parietal regions of anesthetized adult cats. The disruption of the blood brain barrier was examined by checking the degree of the extravasation of Evans blue dye administrated in the vein. The cortical vessel reactivity was observed through the cranial window and evaluated using an intravital microscope and a videoangiometer. The extravasation of Evans blue dye was seen uniformly extending from the histologically changed area into the surrounding tissue in all experiments. The extent of the extravasation of dye was 1 to 1.5 mm larger than the extent of the histologically changed area produced by laser irradiation. Pial arteries in the area with histological changes dilated markedly and some of them lost their blood stream. Pial arteries in the area of Evans blue extravasation, but outside it histological changes also dilated markedly. Furthermore, pial arteries within a distance of 200 to 400 microns from the edge of the Evans blue extravasation area also dilated moderately. A statistical estimation showed that the degree of dilatation of arteries in the area outside the histological change improved significantly in the time course of five minutes.

Animals↗
PubMed1988

Microneurographic analysis of thyrotropin-releasing hormone effects on sympathetic outflow in human muscle nerves.

In order to clarify the human sympathetic response to thyrotropin-releasing hormone (TRH), microneurographic analysis was performed in 12 healthy subjects. Multi-unit vasoconstrictive impulses of muscle nerve sympathetic activity (MSA) were directly recorded from tibial nerve fascicles together with ECG and blood pressure. Subcutaneous injection of saline (1 ml) had no effect on blood pressure and neurograms of MSA. Following s.c. injection of TRH (0.5 mg, 1 ml), however, a significant increase in heart rate and blood pressure occurred 2 min after injection; the change was statistically correlated with increased MSA, and disappeared after about 10 min. The observation suggests that TRH-activated vasoconstrictive impulses of MSA increase the peripheral vascular resistance and elevate blood pressure. We speculate that TRH directly activates vasomotor centers or higher autonomic centers rather than peripheral organs, because the parallel increase of blood pressure and MSA after TRH injection counteracts the effect of baroreflex mechanism.

Adrenergic Fibers↗
PubMed1988

Karyotype evolution and multilineage involvement of Philadelphia chromosome-positive clones in blastic transformation of two patients with chronic myelocytic leukemia.

Simultaneous analysis of the cell morphology and karyotypes on single colonies was carried out in two patients with Philadelphia chromosome (Ph1)-positive chronic myelocytic leukemia in blastic transformation in order to clarify the origin of leukemic cells involved. Patient no. 1 was in a typical myeloblastic transformation and patient no. 2 in "basophilic transformation." Both patients exhibited karyotype evolution in blastic phase (BP), so that we could differentiate BP clones with additional chromosomal abnormalities from chronic phase (CP) clones with only Ph1 among single colonies. The number of single colonies yielding two or more analyzable metaphases was 18 in patient no. 1, and 19 in patient no. 2. Among these colonies, only three in patient no. 1 and none in patient no. 2 were from CP clones and 15 in patient no. 1 and 19 in patient no. 2 were from BP clones. Morphological examination revealed that not only blasts but also mature neutrophils, eosinophils, basophils, macrophages, and erythroblasts were derived from BP clones. These results suggested that (1) BP clones developed at the pluripotent stem cell level, (2) additional chromosomal abnormalities were not restricted to occur in a specific cell line representative in BP; and (3) BP clones, if not all, may retain capacity for maturation and differentiation.

Blast Crisis↗
PubMed1988

[Usefulness of radial artery graft bypass: two cases of internal carotid artery aneurysms].

Trapping and EC-IC bypass surgery was performed for two cases of internal carotid aneurysm using the radial artery as bypass material. Neither case has any permanent neurological deficit because of an adequate blood supply via the radial artery graft bypass. Although the radial artery graft has been in common use among cardiac surgeons, it is still rare in the neurosurgical field. The advantage of the radial artery is discussed with comparison to other graft materials such as saphenous vein and superficial temporal artery. In properly selected cases, the radial artery graft is efficient in preventing the ischemic damage caused by trapping of aneurysm at the main arterial trunk.

Anastomosis, Surgical↗
PubMed1987

[The clinical effect of low-dose Ara-C in patients with refractory acute nonlymphocytic leukemia and myelodysplastic syndrome].

Twenty-one patients with refractory acute nonlymphocytic leukemia (ANLL) and myelodysplastic syndrome were treated with low-dose cytosine arabinoside (LDARC). LDARC was administered by subcutaneous injection every 12 hours at a dose of 10 mg/m2 (regimen A) or at a dose of 20 mg/m2 by continuous intravenous infusion (CIV) or continuous subcutaneous injection (CSC) (regimen B). Among 22 courses, two elderly patients with ANLL (M4 and M5) and one M4 patient with myelofibrosis obtained complete remission (CR) and three elderly patients with ANLL (one M1 and two M2) and one patient with ANLL developed from RAEB in transformation obtained partial remission (PR). The overall remission rate (CR + PR) was 31.8%. The CR durations were 2.5, 5 and 2 months, respectively. The plasma concentration of Ara-C determined in regimen B was 8.26 +/- 4.12 ng/ml. There was no difference in the plasma concentration of Ara-C between CIV and CSC. We consider that the major mode of action of LDARC lies in its cytotoxic effect, since all patients who obtained remission exhibited pancytopenia and bone marrow hypoplasia. However, in several patients, we observed transient monocytosis and granulocytosis which were considered to be suggestive evidence of differentiation of leukemia cells.

Acute Disease↗
PubMed1986

Cerebral hemorrhagic infarction associated with anabolic steroid therapy for hypoplastic anemia.

A twenty-two-year-old student with hypoplastic anemia was treated with large doses of anabolic steroid hormone preparations for two months. Cerebral hemorrhagic infarction shown by CAT scan developed when his hematologic conditions were improving. In treating hypoplastic anemia with anabolic steroid hormone preparations, one should be aware of the possible development of cerebral hemorrhagic infarction at the time of hematologic improvement.

Adult↗
PubMed1986

[Clinical characteristics of contrast medium extravasation from intracranial aneurysms during cerebral angiography: studies on personal experience and review of the literature].

Angiography is essential to diagnosis and treatment for the patients with ruptured intracranial aneurysm in early stage, but on the other hand angiography always involves a risk that extravasation (EV) occurs from the aneurysm during angiography. Once EV occurs, the patient's outcome is poor and, in general, the patient tends to be regard as hopeless of recovery. Over the past 5 years, in 154 patients with ruptured intracranial aneurysm angiography was performed, and in 7 of them EV occurred. We performed neck clipping for ruptured aneurysm in 3 of 7 patients and were able to save the life of 2 patients. We investigated factors to cause EV and to decide outcome in 7 cases and 75 cases of literature, totally 82 cases. Following results were obtained. Occurrence of EV seems to be related to the causal factors of the time interval (within 6 hours) from SAH to angiography and the severity of disturbance of consciousness prior to angiography. It is considered that the patient's outcome is related to age, pre-angiographic severity of disturbance of consciousness, and also time interval from SAH to angiography, but the extent of EV and the number of past history of SAH are not important as the factors related to the outcome. Consequently, the utmost care must be taken for cerebral angiography particularly in patients within 6 hours after the onset of SAH, and in patients with severe disturbance of consciousness. Even if EV should occur, there is a fair chance for life-saving by an emergency surgery in cases with mild disturbance of cerebral function before angiography.

Adult↗
PubMed1986

[Carotid-ophthalmic aneurysms and visual abnormalities].

The direct neck clipping for carotid-ophthalmic aneurysm is hazardous and difficult as compared with other intracranial aneurysms because of its location adjacent to the anterior clinoid process, the optic nerve, and the cavernous sinus. The authors discuss the visual abnormalities accompanied by carotid-ophthalmic aneurysm on the basis of our experiences with 30 patients with 33 aneurysms. Ten patients (4 of 14 with ruptured aneurysms, 6 of 16 intact aneurysms) had preoperative visual abnormalities. Of our series of patients, visual acuity and visual field were impaired in one eye. The most common field abnormalities were unilateral inner or upper side defects. In the patients whose aneurysms were intact, visual abnormalities had been slowly progressive over many months. Otherwise, 2 cases with ruptured aneurysm experienced their first visual symptoms at the same time their hemorrhage. According to the projection of aneurysm with respect to internal carotid artery, superomedial and posteromedial projections were common in the patients with visual abnormalities. Seven patients with visual dysfunctions were operated on. Improvement of the visual symptoms was observed in 3 cases. In these cases, complete collapse of the aneurysm with good decompression of the optic nerve was obtained at operation. Two patients deteriorated following surgery; this occurred in relation to attempts to clip the aneurysm neck directly, and optic nerve was probably excessively manipulated. Two patients had no change in visual symptom: one was treated with trapping of internal carotid artery combined with STA-MCA anastomosis, another had direct hemorrhage into the ipsilateral optic nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗