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Biomedical subjects

K Hashi

Publications and source records attributed to K Hashi.

At least 127 records · Page 7Linked to original sources

Immunofluorescence demonstration of tubulin and actin in estrogen-induced rat prolactinoma cells in vitro. Alteration of their distribution after bromocriptine, colchicine and cytochalasin B treatments.

Cultured cells in vitro from estrogen-induced rat prolactin-secreting adenomas (prolactinomas) were examined by indirect immunofluorescence microscopy for the distribution of cytoskeletal proteins and alterations of cytoskeleton after treatment with bromocriptine, colchicine and cytochalasin B (CB). After 8 days in culture, prolactinoma cells were well expanded and developed cytoplasmic processes were seen. The cytoplasmic microtubules were observed as fine reticular networks radiating from perinuclear portions toward the cell periphery when decorated with an antibody against tubulin. On the other hand, the actin filaments showed diffuse and spotty distribution when detected with an anti-actin antibody. Contaminated fibroblasts showed a reticular distribution of microtubules and a parallel array of actin cables which corresponds to "stress fibers" throughout the cytoplasm. After treatment with bromocriptine, the reticular distribution of microtubules in prolactinoma cells changed into a coarse and sparse pattern, which was identical with the changes in the distribution of tubulin after treatment with colchicine. On the other hand, distribution of actin was not affected by bromocriptine. Bromocriptine treatment did not alter the distribution of microtubules and actin filaments in fibroblasts, whereas colchicine changed the distribution of microtubules in both prolactinoma cells and fibroblasts. CB treatment changed the localization of actin filaments in both kinds of cells. These in vitro studies indicated bromocriptine would selectively affect the cytoplasmic microtubular system of prolactinoma cells.

Actins↗

Giant cell tumor of the skull.

Two cases of giant cell tumor of the skull are reported. The first patient had a radical operation for a giant cell tumor of the temporal base followed by radiation therapy. The second patient had a partial removal of a giant cell tumor of the occipital bone followed by radiation therapy. The pertinent literature on giant cell tumors originating from the cranial bones other than the sphenoid bone is reviewed.

Adolescent↗

[Brain tissue damage in congenital hydrocephalus of the inbred rat, LEW/Jms--intracerebral cavity formation].

Brain tissue damage in congenital hydrocephalic rat (LEW/Jms) was studied in the aspects of the hydrocephalic brain edema and the changes of the vascular apparatus. The characteristic findings in this study were the changes of the small blood vessels and the intracerebral cavity formation. In the acute stage of hydrocephalus (2 to 5 days after birth), spongy appearance and necrosis of the brain edema were observed in the periventricular white matter. The stenotic or obstructive vascular changes were located in connection with the hydrocephalic brain tissue. In this stage, the intracerebral cavity was formed particularly in the periventricular edematous white matter resulting in a thinning of the occipital lobes. In the late stage of hydrocephalus (9 to 15 days after birth), the lateral ventricles were severely dilated, and a markedly dilatated intracerebral cavity was observed in the periventricular white matter. The edematous area was observed adjacent to the dilated lateral ventricles or the intracerebral cavity. In the late stage, the number of small vessels filled with carbon black decreased in the area of the CSF edema when compared to the acute stage, and many obstructive blood vessels were observed in the same area. Moreover, dilatated blood vessels without carbon black were observed in the border zone between the normal and the edematous area adjacent to the intracerebral cavity. These vascular changes may occur by the accumulation of the CSF as well as the mechanical compression, and consequently lead to the microcirculatory disturbance. These microcirculatory disturbances may contribute to the intracerebral cavity formation with the accumulation of the CSF in the extracellular space.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Clinical application of a sustained release anticancer pellet].

During a 6.5-year period from March 1978, 136 patients with brain tumors, which were diagnosed as gliomas or metastatic brain tumors during surgical operation, were treated by the application of sustained release anticancer pellets in seven institutes. Histological diagnosis disclosed that the majority of the tumors were malignant gliomas (61 cases), metastatic brain tumors (35 cases), and benign astrocytoma (17 cases). The anticancer agents (250 mg of 5FU, 1.5 mg of MMC, 250 mg of BUdR and 6,000 iu of urokinase) were sealed in a Silastic silicone tube of 6 mm in diameter, 0.25 mm in wall thickness, and 12 mm in length. The daily delivery of the drugs was (2-3)/10,000 of the original volume. This treatment was combined with surgical and irradiation therapy with or without general chemotherapy. The median survival time of patients with malignant gliomas was 545 days (18 months). The 1-year survival rate was 65.63%, and the 3-year survival rate 16.2%. On the other hand, in patients with benign astrocytomas, the median survival time was 1,500 days (4.1 years), 1-year survival rate 83.75%, and 3-year survival rate 42.84%. In those with metastatic brain tumors, the median survival time was 280 days, 1-year survival rate 43.87%, and 3-year survival rate 24.84%. The present findings revealed that the tube-type anticancer pellets cannot inhibit the growth of the brain tumors located 5 cm from the pellets.

Antineoplastic Agents↗

[Intracranial benign chondroblastoma. A case report and review of the literature].

A case of benign chondroblastoma extending from the nasal cavity to the frontal region, was reported. A 1-year and 9-month old girl was admitted to our hospital in April 1981 because of generalized convulsion. On admission, she was intact neurologically and had It. nasal obstruction and It. eye discharge. Her laboratory examinations, including serum electrolytes and A1-P, were all in normal range. Plain skull X-P showed marked calcification from midfrontal region to the nasal cavity, and destruction of the frontal base especially in It. side. Plain CT showed isodensity mass with spotty calcification in the nasal cavity and marked high density mass in the frontal region. By contrast enhancement, nasal mass was markedly enhanced and new enhanced mass appeared around the intracranial calcification. Lt. ext. CAG showed the enlarged middle meningeal artery which is the feeder of the tumor, fine tumor vessels and slight tumor stain. Lt. int. CAG only showed the mass effect. After three-stage operation of bifrontal craniotomy, sublabial transnasal approach and rhinotomy, all the tumor was removed and she was discharged with no neurological deficits. The tumor was well demarcated and consisted from solid, cystic and calcified region. The solid region was grayish and easy-hemorrhagic. Histological examination revealed characteristic features of benign chondroblastoma, such as diffuse proliferation of polygonal or round cells, foci of chondroid matrices, scattered polynuclear giant cells and some mitosis.

Brain Neoplasms↗

Secondary spinal canal stenosis associated with long-term ventriculoperitoneal shunting.

Secondary changes in the cervical spine were studied in 18 cases with long-term ventriculoperitoneal (VP) shunting. Significant decreases in the anteroposterior diameter of cervical spinal canal and interpedicular distance were noted in patients who had a VP shunt placed before 2 years of age and in whom sustained low intracranial pressure persisted for a long time, as evidenced by early closure of the cranial sutures or thickening of the cranial bones.

Adolescent↗

[Treatment of brain tumors with anticancer pellet--experimental and clinical study (author's transl)].

Eighty three patients suffering from brain tumors have been treated by anticancer pellets containing 5-FU, urokinase, mitomycin and BUdR in dimethylsiloxan (Silastic) for three years. Constant and prolonged release of the chemicals from the anticancer pellet had already been proved in vitro. The amount of daily release were 1-3/1,000 of original volume. Tissue concentration of 5-FU was measured by bioassay system using staphylococcus 209 P strain with plate dilution method. In spite of the rapid disappearance of serum 5-FU, the local high accumulation of 5-FU was demonstrated in vivo. In rat neurogenic tumor, 1.104 microgram/g was detected on 60 days after the application of anticancer pellet containing 500 mg of 5-FU. The growth of tumor was also suppressed. The clinical study consists of 83 patients, 30 of glioblastoma, 19 of metastatic brain tumor, 13 of astrocytoma, 7 of oligodendroglioma, 4 of ependymoblastoma, 4 of malignant lymphoma and 6 of others. The median survival time of gliblastoma was prolonged to 71.5 weeks by the implantation of anticancer pellet from 40 weeks of control group. However, the median survival time of astrocytoma and metastatic brain tumor were 24 and 6 months, respectively, which have no significant difference from control groups. In the patients of metastatic brain tumor, the regrowth of metastatic foci in the brain was completely suppressed. However, most of them were succumbed from the original tumors. The concentration of 5-FU in several human tissue was measured in ten patients with different time intervals after the implantation of the anticancer pellet. Although they have different histologic patterns, the concentrations of 5-FU in human brain tumors were ranged from 0.05 to 0.67 microgram/g by 14 months after the implantation of the anticancer pellet. The adjacent cystic fluids also contain from 0.62 to 4.9 microgram/ml of 5-FU for two years. These results mean that they are keeping higher level of 5-FU than the tumoricidal level of 5-FU (0.056 microgram/g) for more than two years. On the other hand, no respective accumulation was demonstrated in other tissues. None of the patients showed any adverse reactions except a continuous slight fever up to 38 degrees C.

Adult↗

Jugular foramen neurinomas.

Three patients with neurinomas of the jugular foramen are described. One of them had a small tumor confined within the jugular foramen and each of the other two had a tumor originating from the glossopharyngeal nerve. The common feature in all these patients was the presence of marked enlargement of the jugular foramen. Polytomography, jugular venography and bilateral retrograde vertebral arteriography were used to make the diagnosis. Total removal of their tumors was successfully accomplished using microsurgical technique. Forty-two other cases in the world literature are reviewed and analyzed.

Accessory Nerve↗

Middle meningeal--middle cerebral artery anastomosis for cerebral ischemia.

A new technique of anastomosing the middle meningeal artery to a cortical branch of the middle cerebral artery is described. A case is presented in which the operation was technically successful and the immediate clinical result was good. Long-range follow-up is necessary and a larger series will be needed for study before the merits of the technique can be judged adequately. The advantages and disadvantages of this technique are described, as well as possible indications and future studies.

Blood Vessel Prosthesis↗

Endothelial damage in microvascular anastomosis: to splint or not to splint?

When performing a microvascular anastomosis, some surgeons use a splint and others do not. We compared the difference in intravascular reactions observed in the carotid artery of the rat anastomosed with these two techniques by observation with a scanning electron microscope. Thrombus formation was more prominent in the artery anastomosed using a splint. The difference was most remarkable 20 minutes after anastomosis. With time, the difference became less remarkable and was no longer present by seven days. By fourteen days, the anastomotic site was covered with neoendothelium. It is concluded that there is little difference in the final outcome achieved by the two methods.

Animals↗

[Hydrocortisone for the treatment of cerebral vasopasm--(1) experiments in dogs (author's transl)].

The usefulness of hydrocortisone for the treatment of cerebral vasospasm was investigated using dogs by measuring changes in cerebral arterial diameter in angiograms as well as in other parameters such as blood pressure, intracranial pressure and CBF. The intrathecal (50-300 mg) or intravenous (100 mg/kg) injection of hydrocortisone resulted in a marked dilatation of cerebral arteries both in control animals and vasospastic animals after subarachnoid hemorrhage. The intrathecal injection caused a temporary rise in blood pressure immediately following the injection. Cerebrospinal fluid pressure was increased progressively. On the other hand, the intravenous injection resulted in a fall in blood pressure and a transient rise in cerebrospinal fluid pressure. CBF showed a tendency to increase both with intrathecal and intravenous injection. With intravenous injection a high CSF level of cortisol was found 1 and 2 hours after the injection and it was correlated to the degree of cerebral arterial dilatation, indicating that a significant amount of hydrocortisone could penetrate into the CSF and dilate the intracranial vessels by its direct pharmacological action.

Animals↗

The EEG in normal pressure hydrocephalus.

Fourteen patients with NPH were studied with special reference to associated EEG changes, one case being reported in detail. In 13 cases the EEG was abnormal, the abnormality most frequently observed being a of the rhythmic slow wave type, consisting of bursts of monorhythmic theta or delta waves seen in both hemispheres. This type of abnormality was present in 7 cases. In 4 of the 5 cases with serial EEG's the abnormality became more accentuated with the advance of the illness. In 4 of 5 cases in whom postoperative EEGs were obtained there was significant improvement of the EEG after the shunting procedure. There were stron correlations between the EEG abnormality described, demonstrable ventricular reflux on cisternography, and the effectiveness of the shunt operation. It was considered that serial EEGs are a useful diagnostic procedure in following up patients at risk of developing NPH.

Adult↗