Search PubMed⌕ Search

Biomedical subjects

M Tomonaga

Publications and source records attributed to M Tomonaga.

At least 343 records · Page 19Linked to original sources
PubMed1988

K562 cells produce and respond to human erythroid-potentiating activity.

Human erythroid-potentiating activity (EPA) is a 28,000 mol wt glycoprotein that stimulates the growth of erythroid progenitors in vitro and enhances colony formation by the K562 human erythroleukemia cell line. EPA has potent protease inhibitory activity, and is also referred to as tissue inhibitor of metalloproteinases (TIMP). We observed that colony formation by K562 cells in semi-solid medium containing reduced fetal calf serum (FCS) is not directly proportional to the number of cells plated, suggesting production of autostimulatory factors by K562 cells. Using radioimmunoprecipitation and a bioassay for EPA, medium conditioned by K562 cells was found to contain high levels of biologically active EPA; Northern hybridization analysis confirmed the expression of EPA mRNA. Radiolabeled EPA was used to identify cell surface receptors on K562 cells. Together, these results suggest that EPA may act as an autocrine growth factor for K562 cells.

Affinity Labels↗
PubMed1988

Reclassification of leukemia among A-bomb survivors in Nagasaki using French-American-British (FAB) classification for acute leukemia.

The concordance rate for diagnoses of atomic bomb-related cases of leukemia in Nagasaki was determined using the French-American-British (FAB) classification for acute leukemias and myelodysplastic syndromes (MDS). Two Radiation Effects Research Foundation (RERF) hematologists and one of the members (JMB) of the FAB cooperative group reviewed independently the peripheral blood and/or bone marrow smears from 193 people with leukemia or a related disorder. There was 85% agreement in the identification of types and subtypes of acute leukemia. There was almost complete agreement for the diagnoses of non-FAB disorders (chronic myeloid leukemia (CML), adult T-cell leukemia (ATL) and others) resulting in overall concordance of 88.2%. The present study suggests that the previously established leukemia types for about a quarter of the cases of acute leukemia and related disorders except CML should be changed. Considerable numbers of cases of ATL and MDS were involved in this series. The frequency of the former disease was not high in the high-dose irradiated group, but that of the latter was considerably high. All subtypes of AML except M3 and M6 were present in the high-dose group. The striking difference in CML incidence between Nagasaki and Hiroshima may continue to be a problem in relation to biological response to radiation exposure.

Acute Disease↗
PubMed1988

[Benign osteoblastoma of the parietal bones].

Benign osteoblastoma accounts for less than 1% of the primary bone tumors and the calvarial lesion is extremely rare. There are only 12 reported cases in the literature as far as we could collect. We have presented a case of benign osteoblastoma originated from the parietal bone. This 9-year-old boy struck his head on the parietal region and noticed the bulging at the same site. A month later he visited to Fukuoka University Hospital because of persistent bulging of the same site. Neurological examinations were normal. Plain skull roentgenogram on Towne view showed radiolucent area in the midline of parietal bones with irregular margins and in tangential view the outer table revealed thinning and expanding. Coronal CT scan demonstrated same abnormality and intact inner table. The tumor was located within the dipole in the bilateral parietal bones and was removed by a simple curettage. The microscopic feature showed numerous osteoblasts, osteoblastic rimming and many multinucleated giant cells. These indicated a typical benign osteoblastoma. He has been doing well one year after the operation without any evidence of recurrence.

Child↗
PubMed1988

[A case of colloid cyst of the third ventricle].

Colloid cysts of the third ventricle are rare, accounting for less than 1% of all intracranial neoplasms. However, its incidence will increase with increased use of CT scan and MRI. The symptomatology is principally acute or chronic hydrocephalus obstructing the foramen of Monro, and the origin of this cyst is controversial, neuroepithelial or endodermal. We report a case of colloid cyst of the third ventricle, associated with cavum veli interpositi. The patient, a 46-years-old female, had suffered from headache, ataxic gait and tremor lasting 6 months. CT scan and homogenous high signal intensity by SR (2450/450) MR image, detected a small round mass in the anterior part of the third ventricle that was of homogenous high density, but without the effect of enhancement. The lateral ventricle was markedly dilated, and a large cavum veli interpositi was found between the third ventricle and the corpus callosum. The cyst was totally removed by transventricular approach, and the result was satisfactory. We reviewed literatures and discussed MRI findings of colloid cysts of the third ventricle. Because of the presence of microvilli covered with coating materials seen in electron microscopic study, we suggested that the colloid cyst was endodermal in origin.

Brain Diseases↗
PubMed1988

Growth and differentiation of circulating hemopoietic stem cells with atomic bomb irradiation-induced chromosome abnormalities.

The effects of atomic bomb irradiation on hemopoietic stem cells were studied cytogenetically using single colonies derived from hemopoietic progenitor cells. The subjects studied were 21 healthy atomic bomb survivors (10 males and 11 females) in the high dose exposure group (100+ rad) with a known high incidence (10% or more) of radiation-induced chromosome abnormalities in their peripheral blood lymphocytes (stimulated with phytohemagglutinin), and 11 nonexposed healthy controls (5 males and 6 females). Colony formation by circulating granulocyte-macrophage (GM-CFC) and erythroid (BFU-E) progenitor cells was made by the methylcellulose method using peripheral blood mononuclear cells. Chromosome specimens were prepared from single colonies by our micromethod. The total number of colonies analyzed in the exposed group was 131 for GM-CFC and 75 for BFU-E. Chromosome abnormalities were observed in 15 (11.5%) and 9 (12.0%) colonies, respectively. In the control group, the total number of colonies analyzed was 61 for GM-CFC and 41 for BFU-E. None of these colonies showed chromosome abnormalities. The difference in incidence of chromosome abnormalities was highly significant by an exact test; p = 0.003 for GM-CFC and 0.017 for BFU-E. The karyotypes of chromosome abnormalities obtained from the colonies in the exposed group were mostly translocations, but deletion and marker chromosomes were also observed. In two individuals, such karyotypic abnormalities as observed in the peripheral lymphocytes were also seen in the myeloid progenitor cells. This finding suggests that atomic bomb irradiation produced a chromosome aberration on multipotent hemopoietic stem cells common to myeloid and lymphoid lineages. These stem cells, although carrying chromosome defects, are likely to have survived for more than 30 years, continuously producing progenitor cells capable of normal-looking growth and differentiation.

Adult↗
PubMed1988

[Postoperative pulmonary embolism in neurosurgical practice: report of two cases].

Pulmonary embolism following postoperative deep venous thrombosis is a very serious complication with a high mortality rate. Though this disorder has been thought to be rare in Japanese, its occurrence seems to be increasing recently because of changes in eating habits, increase of average age and the frequent practice of venous catheterization. Two cases of the pulmonary embolism following deep venous thrombosis after surgery are reported, and possible causes of the deep venous thrombosis are discussed. Case 1: A 48 year-old obese female was operated on for a posterior fossa dural arteriovenous malformation. On the 4th postoperative day, she developed a pain and swelling in the left leg and low back pain. On the 18th postoperative day, she fell into a state of shock following the sudden onset of a severe back pain and respiratory distress. After diagnosis of the pulmonary embolism, she was immediately treated with urokinase, warfarin and aspirin. Her obesity was considered to be one of the risk factors of the postoperative deep venous thrombosis. Case 2: A 62 year-old female with a ruptured cerebral aneurysm could not get out of bed because of postoperative mental disturbance. A central venous pressure catheter was inserted into the right femoral vein for two weeks postoperatively. One month after surgery, she complained of swelling and a dull pain in the right leg without cardiorespiratory symptoms. Lung perfusion scintigraphy showed asymptomatic pulmonary embolism. She was treated immediately. Both long bed rest and femoral venous catheterization were considered as risk factors possibly leading to deep venous thrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1987

Potentiation of pressor response to angiotensin II at the preoptic area in spontaneously hypertensive rat.

Cardiovascular responses to angiotensin II(AII) at the preoptic area (POA) were compared between normotensive Wistar Kyoto rat (WKY) and spontaneously hypertensive rat(SHR) by measuring blood pressure and heart rate under unrestrained, conscious state via a catheter implanted chronically into the abdominal aorta and by injection of drugs into POA through a chronic guide cannula. AII injected into POA at doses of 0.3 ng and 1 ng produced a dose-dependent pressor response, accompanied with a slight decrease of heart rate, in both WKY and SHR. However, in SHR, the pressor response to AII was more than 2 times greater than that in WKY and was quick in onset and lasted about 30 min. When AII in combination with [Sar1, Ile8]-angiotensin II (0.5 microgram), an AII receptor antagonist, were simultaneously administered to POA, the pressor response to AII was strongly inhibited in both WKY and SHR. The results suggest that the pressor response to AII due to its receptor stimulation at POA is markedly potentiated in SHR.

Angiotensin II↗
PubMed1987

Loss of nerve growth factor receptors in sympathetic ganglia from aged mice.

[125I]-Nerve growth factor (NGF) binding was studied in superior cervical ganglia from mice 4-7 months and 24-27 months of age. Scatchard analysis demonstrated losses of both high and low affinity components of NGF receptor. These results indicate loss of NGF receptors may lead to the diminished responsiveness to NGF in aged sympathetic ganglion neurons.

Aging↗
PubMed1987

Neurofibrillary tangles in human upper cervical ganglia. Morphological study with immunohistochemistry and electron microscopy.

Neurofibrillary tangles (NFTs) are one of the main pathological hallmarks of Alzheimer's disease or senile dementia, and are seen in the cerebral cortex and some other nuclei in the central nervous system (CNS). No NFTs have been reported in the human peripheral nervous system, although NFTs were recognized in the dorsal root ganglion of the aged rodents. We report here the presence of NFTs in the upper cervical ganglia (UCGs), but not in the stellate nor in the celiac ganglia, of an elderly patient, who was not demented and had only minimal senile changes in the CNS. Immunohistochemically the antibodies to microtubule-associated protein 2, paired helical filaments and ubiquitin stained positively the NFTs in the UCGs. On electron microscopic examination a periodical twisted pattern of the filaments was identified; these findings suggest that the NFTs of the UCGs have just the same properties as those of the cerebral cortex. This is the first report of the demonstration of NFTs in the peripheral ganglia and might contribute to the study of mechanism of NFT production.

Aged↗
PubMed1987

Peculiar pattern of glial fibrillary acidic protein production in extracranial metastatic tumor cells of malignant astrocytoma.

An 83-year-old woman suffered from malignant astrocytoma originating in the temporal lobe. Autopsy revealed its extracranial metastasis to the liver, lung and bone marrow. The tumor tissue at the primary site was composed of plump, process-forming cells and small cells with scanty cytoplasm, and showed dural invasion. In the metastatic areas, most of the tumor cells were small cells, although proliferation of the plump cells in contact with perivascular connective tissue was marked, particularly in the liver. These plump cells were positively stained with antiserum to glial fibrillary acidic protein (GFAP), showing that the collagenous tissue was able to induce increased production of GFAP by the glial tumor cells.

Aged↗
PubMed1987

Effect of mannitol on cerebral blood flow and microcirculation during experimental middle cerebral artery occlusion.

Regional cerebral blood flow (rCBF) was measured during and after a 2-3 hour occlusion period of the middle cerebral artery (MCA) in cats with the hydrogen clearance technique. The effects of mannitol upon rCBF were studied. Transient hypotension during occlusion dropped the blood flow to near zero on the occluded side, leading to postischemic hypoperfusion. Mannitol failed to modify blood flow during the occlusion period, but was effective in preventing any further decrease of blood flow during hypotension. Animals receiving mannitol had an improved postischemic recovery of blood flow. The correlation of ischemic severity and postischemic brain damage and the effects of mannitol on these parameters are discussed.

Animals↗