Search PubMed⌕ Search

Biomedical subjects

S Ban

Publications and source records attributed to S Ban.

At least 145 records · Page 8Linked to original sources
PubMed1987

Lethal and mutagenic effects of 252Cf radiation in cultured human cells.

HeLa MR cells were exposed to radiation emitted from a man-made spontaneously fissioning isotope, californium-252. The neutron to gamma-ray ratio in the radiation dose was measured to be 2.0. The extrapolation number of the dose-survival curve was 1.3 and the Do was 200 cGy. A dose-dependent increase in mutation to 6-TGr (6-thioguanine resistant) was observed. The relative biological effectiveness (r.b.e.) for cell killing of the neutrons from 252Cf, calculated relative to high-dose-rate X-rays, was 2.6 at 50 per cent survival. The r.b.e. for mutation induction was 2.7 at a mutation frequency of 5 X 10(-5) per surviving cell.

Californium↗
PubMed1987

[Preoperative embolization with gelfoam powder for intracranial meningioma causing unusual peritumoral hemorrhage--with reference to the mechanism of hemorrhage].

Preoperative embolization for intracranial meningioma has been performed at many institutions and its effectiveness has been well recognized. The complications of embolization such as facial pain, fever and facial nerve palsy, et al, were mild and temporary except embolus migration into intracranial vessels, but a peritumoral hemorrhage due to preoperative embolization was extremely rare. Recently we have experienced such an unusual complication, then we describe this complication here and discuss the mechanism of hemorrhage briefly. A 73-year-old female who had the left falx meningioma underwent preoperative embolization with gelfoam powder through the transfemoral route. About 10 hours later, she developed disturbance of consciousness and right hemiplegia. At that time, CT scan showed peritumoral hemorrhage and an increase in midline shift. An emergency craniotomy was performed and total removal of the falx meningioma (Simpson grade II) and evacuation of the hematoma were done. The postoperative course was uneventful. We conclude that gelfoam powder (average particle size 40-60 mu) is a useful material for preoperative embolization but may at times cause peritumoral hemorrhage.

Aged↗
PubMed1986

[The relationship between cell kinetics and histological features of giant cell tumor of the bone].

This study was undertaken to clarify the relationship between the proliferative activity and histological findings of the giant cell tumor (GCT) of bone by means of an epi-illumination cytofluorometer (NIKON SPM-RF1-D). Fresh tissues of GCT were surgically obtained from two cases. In both cases, small pieces of tumor tissues were obtained from several different regions based on the macroscopic characteristics of the cut surface, and processed for single cell preparation using enzymatic method. These isolated cells were smeared and stained with acridine orange, and then analyzed cytofluorometrically to determine simultaneously DNA and RNA contents of the individual cells. The results showed that the proliferative activity of tumor cells was much higher in the regions composed of both many histiocytic stromal cells having polygonal or ovoid shape and many multinucleated giant cells, than either in the regions composed of fibrocytic stromal cells accompanying abundant collagen fibers or in the regions composed of foamy cells.

Adult↗
PubMed1986

[Unusual case of depressed fracture of the posterior cranial fossa associated with the syndrome of acute central cervical spinal cord injury].

Linear fractures through the occipital bone are common, whereas depressed fractures in the posterior cranial fossa are rare because the occipital bone is protected by the surrounding thick muscles. The authors describe an unusual case of depressed fracture localized in the posterior cranial fossa associated with the syndrome of acute central cervical spinal cord injury. A 50-year-old female struck her face against the table and fell backward, while drunk, resulting in the bruise over the occipital region. Three days after injury she was transferred to our hospital because of progressive disturbance of consciousness, brain stem dysfunction and tetraplegia. Neurological examination on admission showed that she was drowsy, had tetraplegia and could not speak. However, she could obey commands only by moving her eyes and the ocular movements were normal in all directions except for horizontal nystagmus. Plain skull x-ray revealed a conspicuously depressed fracture in the posterior cranial fossa, but cervical spine x-ray showed neither fracture nor dislocation. Immediately suboccipital craniectomy was done and there were a thin subdural hematoma on the cerebellar surface, cerebellar contusion, and subarachnoid hemorrhage around the cisterna magna. Soon after operation impaired consciousness and paraplegia were improved, but recovery of both arms was delayed. Five months after injury, she still had left IX, X and XI nerve paresis, bilateral arm weakness, dysarthria, swallowing disturbance and bilateral sensory disturbance below C4 level. These findings indicated that she had sustained brain stem and cerebellar compression by the depressed fracture and also had suffered an acute central cervical spinal cord injury.

Cranial Fossa, Posterior↗
PubMed1985

[Distal anterior cerebral artery aneurysm causing acute subdural hematoma: report of two cases].

We report two cases of distal anterior cerebral artery aneurysms (distal ACA-aneurysm) causing acute subdural hematomas, which were diagnosed preoperatively. Case 1: 56 y.o. female who presented with stupor and right hemiparesis, was operated on 8 hrs. post-ictus. Case 2: 51 y.o. female who presented with semi-coma, anisocoria and decerebrate posture was operated on 5 hrs. post-ictus. She is alive in fair condition at present. Incidence of acute subdural hematomas in association with ruptured cerebral aneurysms has been reported as variously as 0.5 to 7.9% (clinical cases), with their source of bleeding being either IC or MCA aneurysms. Acute subdural hematomas as complication of ruptured distal ACA aneurysms are rare, and to the authors' knowledge, only 6 cases have been reported so far. Review of the literature regarding mechanism of formation of subdural hematoma, clinical course and treatment of choice are also reported.

Acute Disease↗
PubMed1985

[DNA cytofluorometric analysis of nerve sheath tumors].

The present study was undertaken to clarify the ploidy patterns of peripheral nerve sheath tumors by determining nuclear DNA content of the individual tumor cells using PI-DNA cytofluorometry (NIKON SPM-RF1-D), and to investigate the relation between the ploidy patterns and histopathological findings. Most of the solitary neurilemmomas and neurofibromas studied were found to be associated with euploid-polyploidization, almost without DNA synthetic cells. It was also shown that the number of polyploid cells increased in accordance with an increase in the frequency of cells having large, atypical nuclei in histological picture, regardless of the natures of cellular arrangements. Malignant schwannomas, however, were composed of many polyploid and aneuploid cells with an increase of DNA synthetic cells, indicating their active cell proliferation. Thus, the ploidy patterns of nerve sheath tumors were remarkably different between benign and malignant ones. Furthermore, a case of multiple schwannoma suspected to be a variant of von Recklinghausen's disease, showed euploid-polyploidization with many DNA synthetic cells, indicating a ploidy pattern intermediate between benign and malignant tumors. This tumor thus appears to be a premalignant tumor or in the early stages of malignancy.

Adolescent↗
PubMed1984

Induced radioactivities in concrete constituents irradiated by high-energy particles.

The powdered concrete constituents of magnetite ore, pyrites ore, marble, gravel and Portland cement were prepared and irradiated by 12- GeV protons and secondary particles at the slow extracted beam line of the National Laboratory for High Energy Physics ( KEK ) 12- GeV proton synchrotron. The saturated activities for individual nuclides produced were calculated, and the time variation of photon exposure rate due to the residual activities was also evaluated for each sample. The exposure rates ranked in the following order: magnetite ore greater than pyrites ore greater than gravel greater than or equal to cement greater than marble. The levels of photon exposure rates from heavy, ordinary and marble concretes were also estimated on the basis of the results obtained for each constituent. It is suggested that the use of marble concrete in the inside wall of accelerator tunnels can reduce considerably the exposure to the accelerator maintenance workers, compared with heavy and ordinary concretes commonly used.

Construction Materials↗