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Biomedical subjects

N Aoki

Publications and source records attributed to N Aoki.

At least 433 records · Page 24Linked to original sources
PubMed1989

[Serial changes in lung injury produced by preformed immune complexes].

A previous study demonstrated increased levels of C5a des Arg and increased numbers of polymorphonuclear cells (PMNs) in bronchoalveolar lavage (BAL) fluids of acutely ill patients with summer type hypersensitivity pneumonitis (HP), suggesting the role of immune complexes (IC) in the early stage of HP. The present study was undertaken to compare the BAL findings in patients with acute HP and in animals which were injected intratracheally with preformed IC and to determine the correlation between the sequential BAL findings and the serial histology in animals. The results indicated that total cells recovered by BAL increased up to 24 hours. However, the most striking observation was that the increased number and percentage of PMNs in BAL cells shortly after the intratracheal injection, which the number of macrophages in BAL cells tended to be high, the increase was not statistically significant. Histological examinations revealed peribronchial and intraalveolar infiltration with PMNs at the early stage when intraalveolar infiltration were predominant, and the latest lesions consisted of infiltration with mononuclear cells in the alveolar walls. Furthermore, the cellular findings of BAL cells reflected the histological findings in involved lungs. The present study demonstrated that the sequential BAL changes of acutely ill patients with HP were similar to those of IC-injected animals, suggesting the possibility that IC formed in the airways is involved in the early stage of HP.

Alveolitis, Extrinsic Allergic↗
PubMed1989

[An adult case of moyamoya disease associated with marked advance of occlusive lesion in the bilateral carotid system].

We reported an adult case with moyamoya disease in which unilateral obstructive process proceeded to the bilateral lesion during a period of 45 months. A 30-year-old female was admitted to our institute due to frequent ischemic episodes since she was 25 years old. At the time of admission, she was asymptomatic with slightly disturbed psychogenic reactions. At the time of the initial cerebral angiography when she was 25 years old, the right cerebral angiography demonstrated stenosis of the right ICA terminal portion with moyamoya vessels in the basal area and leptomeningeal anastomosis at the right parietal area. The left cerebral angiography revealed normal ICA system with a lightly narrowing Al portion, without Moyamoya vessels. The second cerebral angiography, taken 45 months after the initial angiography, demonstrated progression stenosis of the right ICA terminal portion, with decreasing moyamoya vessels at the basal area, obstruction of the left ICA terminal portion, stenosis at the Al portion with newly developed moyamoya vessels in the left basal area. We concluded at this time that this case was a definite case of moyamoya disease. The third cerebral angiography after right SDP (synangio-dural plasty), 49 months after the initial angiography, revealed, in the right angiography, newly formed anastomotic vessels perfusing the middle cerebral artery region via the extracerebral arteries and in the left cerebral angiography, and an increased obstruction of the ICA terminal portion, transdural anastomosis via the extracerebral arterial system, and a decrease of moyamoya vessels in the basal area. This rare case provided us a good picture of the pathogenic mechanism of moyamoya disease.

Adult↗
PubMed1988

Characterization of an apparently lower molecular weight gamma-chain variant in fibrinogen Kyoto I. The replacement of gamma-asparagine 308 by lysine which causes accelerated cleavage of fragment D1 by plasmin and the generation of a new plasmin cleavage site.

Congenitally abnormal fibrinogen Kyoto I with impaired fibrin monomer polymerization contains a normal gamma-chain and a gamma-chain variant (gamma Kyoto I) that has an apparently lower Mr on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the Laemmli system (Laemmli, U. K. (1970) Nature 227, 680-685) but migrates with apparently normal Mr in the Weber and Osborn system (Weber, K., and Osborn, M. (1969) J. Biol. Chem. 244, 4406-4412). Reverse-phase high performance liquid chromatographic analyses of the cyanogen bromide or lysyl endopeptidase cleavage fragments of the purified gamma-chains of fibrinogen Kyoto I showed the presence of peptides not seen from normal fibrinogen. Amino acid sequence analysis of these peptides indicated that gamma Asn308 of the gamma-chain variant is replaced by lysine. Purified fragment D1 of fibrinogen Kyoto I also contains two types of D1 gamma-remnants: normal and apparently lower Mr types. Abnormal fragment D1 is cleaved faster to fragments D2 and D3 by plasmin in the presence of [ethylenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA) than normal fragment D1, as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by immunoblotting using anti-gamma-chain monoclonal antibody. Analysis of peptides released from fragment D1 by plasmin in the presence of EGTA demonstrated the cleavage of the gamma Lys308-Gly309 bond. Fragment D1 of fibrinogen Kyoto I has normal calcium binding properties. The data suggest that a region or conformation containing gamma Asn308 affects the polymerization of fibrin monomers and that the gamma Asn308----Lys replacement causes a conformational change in the gamma-chain which results in the accelerated cleavage of gamma Lys356-Ala357 and gamma Lys302-Phe303 bonds by plasmin and also results in the generation of a new plasmin cleavage site between Lys308 and Gly309 in the presence of EGTA. During these studies, we found that part of the gamma Lys212-Glu213 bond in fragment D1 is cleaved by plasmin in the presence of EGTA.

Amino Acid Sequence↗
PubMed1988

Cytotoxicity of 4-hydroperoxycyclophosphamide for the blast progenitors of acute myeloblastic leukemia.

The effects of 4-hydroperoxycyclophosphamide (4-HC), an analogue of cyclophosphamide, on the blast progenitors from eight acute myeloblastic leukemia patients were studied in methylcellulose and suspension cultures. Leukemic blast progenitors undergo terminal divisions in methylcellulose culture, making blast colonies. Cells in primary colonies can make secondary colonies after replating in fresh methylcellulose medium. Leukemic blast progenitors grow exponentially in suspension culture for periods of weeks. The ability to form secondary colonies and the exponential growth in suspension culture are considered to reflect the self-renewal of blast progenitors. 4-HC suppressed primary blast colonies in a dose-responsive manner. Secondary colonies were not significantly affected by 4-HC. Although the clonogenic cell recovery was suppressed by 4-HC, leukemic blast progenitors were less sensitive to 4-HC in suspension culture than in methylcellulose culture. The results suggest that 4-HC is effective in suppressing the terminal divisions of blast progenitors but not as effective against the self-renewal of blast progenitors.

Adult↗
PubMed1988

Effects of purified human native granulocyte colony-stimulating factor (G-CSF) on proliferation of blast progenitors in acute myeloblastic leukemia.

Blast progenitors in acute myeloblastic leukemia (AML) grow in methylcellulose and suspension cultures. Blast colony formation in methylcellulose culture reflects the terminal divisions of blast progenitors, while secondary colony formation, by replating in methylcellulose and recovering clonogenic cells in suspension culture, reflects the self-renewal of blast progenitors. To analyze the regulatory mechanisms of the proliferation of leukemic blast progenitors, the effects of highly purified native granulocyte colony-stimulating factor (G-CSF) obtained from human squamous cell carcinoma line (CHU-2) on blast progenitors in AML patients were studied in methylcellulose and suspension cultures. Purified G-CSF stimulated the growth of blast progenitors in both culture systems, although sensitivity to G-CSF varied from patient to patient. No obvious maturation of leukemic blasts was noted in suspension culture in the presence of G-CSF. The data suggest that a normal hemopoietic regulator may play a role in the growth of blast progenitors in AML patients.

Adult↗
PubMed1988

Undetectable bcr-abl rearrangements in some CML patients are due to a deletion mutation in the bcr gene.

Most patients with chronic myelogenous leukemia (CML) have Philadelphia (Ph) chromosome. Breakpoints on chromosome 22 in CML occur in a small region designated as the breakpoint cluster region (bcr). More than 90 percent of CML patients have breakpoints in the bcr; the remaining patients had no detectable rearrangement. In our study, a commercially available 1.2 kb HindIII-BglII (1.2 HBg) bcr probe was used to locate breakpoints in the bcr, which were found in 22 of 24 patients. Furthermore, using a probe upstream from the 1.2 HBg probe, rearranged bands were clearly detected in the two patients in whom no extra bands had been found with the 1.2 HBg probe. These results strongly suggest that these two patients carry a deletion at the acr-abl recombination point encompassing the area of the 1.2 HBg probe. Therefore, in our series, all CML patients eventually had breakpoints in the bcr, and the involvement of rearrangement was demonstrated to be highly specific for CML. Our data indicate that hybridization of CML cellular DNA with several bcr probes is important in examining accurately the frequency of bcr-abl rearrangements in CML, as some cases contain a deletion within the region.

Chromosome Aberrations↗
PubMed1988

Ventricular shunt functioning despite extraventricular location of the catheter tip as revealed by computed tomography.

Two cases of infantile hydrocephalus are reported, in which the ventricular shunt proved to function despite the catheter tip being located outside the ventricular system, as revealed by computed tomography. This condition could be erroneously diagnosed as arrested hydrocephalus or proximal shunt malfunction, with a resultant potential risk of inadequately removing the catheter.

Cerebrospinal Fluid Shunts↗
PubMed1988

Combined contralateral pterional and interhemispheric approach to a subchiasmal carotid-ophthalmic aneurysm.

A subchiasmal carotid-ophthalmic aneurysm was clipped through a combined contralateral pterional and interhemispheric approach. This combined approach seems very useful for some particular aneurysms of this portion because of no dead angle around the aneurysm and the minimum retraction required for the brain and optic nerve. Surgical approaches to subchiasmal carotidophthalmic aneurysms are discussed.

Adult↗
PubMed1988

Antithrombin III concentrate in the treatment of fulminant hepatic failure.

Twenty-six patients with fulminant hepatic failure were treated with daily infusions of antithrombin III concentrate until recovery of consciousness or death. Seven patients were alive (group A), 7 survived 17 to 47 days after treatment (group B), and 12 died within 9 days (group C). Decreased plasma antithrombin III levels increased on the day after treatment, irrespective of the pretreatment levels in all patients. Continuous or temporary normalization was seen in all patients in groups A and B, but in only 5 in group C patients whose bleeding was extensive (p less than 0.05). An abrupt drop in peripheral platelet counts occurred when plasma antithrombin III levels were below normal. General bleeding accompanied this drop. These results suggest that maintained normal plasma antithrombin III levels are beneficial for prolonged survival time in fulminant hepatic failure, probably through controlling intravascular coagulation, and that antithrombin III infusion may be useful for such treatment.

Antithrombin III↗
PubMed1988

Atlantoaxial dislocation presenting as sudden onset of quadriplegia in Down's syndrome.

A sudden onset of quadriplegia and dyspnea occurred in a 4-year-old girl with Down's syndrome, who had been noted to have atlantoaxial dislocation. She underwent cervical immobilization initially with a halo-vest and subsequently by posterior fusion, resulting in significant functional recovery. The catastrophic myelopathy that occurred in this patient emphasizes the necessity of treatment even for asymptomatic atlantoaxial instability in some individuals with Down's syndrome.

Atlanto-Axial Joint↗
PubMed1988

Acute subdural hematoma due to minor head trauma in patients with a lumboperitoneal shunt.

The cases of four patients treated with a lumboperitoneal shunt in whom acute subdural hematoma occurred after minor head trauma are presented. Three of the four patients had subdural fluid collection or widening of subarachnoid space observed on computed tomography scan after placement of the lumboperitoneal shunt. We report that patients with a lumboperitoneal shunt have the potential to develop acute subdural hematoma due to minor head trauma, and discuss its mechanism.

Acute Disease↗
PubMed1988

Effects of natural human interferon-alpha, -beta and -gamma on interleukin 2 production in human peripheral lymphocytes.

Effects of interferon (IFN) on PHA-induced interleukin 2 (IL-2) production by human peripheral mononuclear cells were studied comparatively with natural human IFN-alpha, IFN-beta and IFN-gamma, using an equivalent unit of their antiviral activity ranging from 10 to 1000 IU/ml. IL-2 activity was assessed in cultures with or without IFN by a standard bioassay using murine CTLL-2 cells. PHA-induced production of IL-2 in cultures of peripheral mononuclear cells was unaltered or slightly suppressed by the simultaneous presence of IFN-alpha and IFN-beta. The effect was the same, whether or not indomethacin was present in the cultures. In contrast, the addition of IFN-gamma to the PHA-stimulated cultures markedly enhanced IL-2 production, while IFN-gamma per se had no effect on IL-2 production in the absence of PHA. The enhancement of IL-2 production due to IFN-gamma was more marked in cultures which did not include indomethacin than in cultures which contained indomethacin (1 x 10(-6) M).

Humans↗