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Biomedical subjects

N Aoki

Publications and source records attributed to N Aoki.

At least 487 records · Page 27Linked to original sources

Percutaneous subdural tapping for the treatment of chronic subdural haematoma in adults.

Chronic subdural haematoma in adults has been treated by percutaneous subdural tapping using a subdural needle. In order to prevent recurrence, the procedure including replacement of the haematoma with oxygen, irrigation using relatively small amounts of saline, and additional drainage for one hour proved to be simple and reliable. The detailed technique is illustrated, and sequential computed tomography scans in six patients treated with this procedure are presented.

Aged↗

Chromosomal translocation and inverted duplication associated with integrated hepatitis B virus in hepatocellular carcinomas.

Integrated hepatitis B virus (HBV) DNA is found in hepatocellular carcinomas which develop in HBV carriers. Presented here are the results of analyses of four integrants that show chromosomal rearrangements associated with the integrated HBV DNA. Two clones (p4 and C15) were found to have large inverted repeating structures, each consisting of HBV genome along with flanking cellular sequences. The structure must have arisen by duplication of the primary integrant, including the flanking cellular DNA, followed by recombination within the viral DNA. One of the two viral arms in each clone joins to the other viral arm at the "cohesive end region." Two clones (DA2-2 and DA2-6) were found to have integrated HBV sequences, each flanked by cellular DNAs from different chromosomes (chromosome X joined to 17 and chromosome 5 joined to 9). They must be the products of cellular DNA translocations using the integrated HBV DNA as the switch point. The viral DNA in each clone is a continuous stretch of a single virus genome with one end in the cohesive end region. These complex structures seem to have been produced by activation of the cohesive end of an integrant viral genome, followed by its recombination with another chromosomal DNA.

Base Sequence↗

Communicating fourth ventricular hydrocephalus: case report.

The case of an infant with hydrocephalic enlargement of the 4th ventricle and dilatation of the basal cisterns is presented. Although the lateral ventricular shunt was proved to be functioning, the patient developed supratentorial hypertension marked by a tense fontanelle. Placement of a 4th ventricle-peritoneum shunt was followed by shrinkage of the 4th ventricle and resolution of the supratentorial hypertension. Work-up, including computed tomographic ventriculography and cisternography, demonstrated occlusion of the aqueduct of Sylvius and of subarachnoid spaces. This unique pathological process, differentiated from an isolated 4th ventricle, could be referred to as communicating 4th ventricular hydrocephalus.

Cerebral Ventricles↗

Projection of mortality from cerebrovascular disease, 1985 through 2000 A.D., in Japan.

Trends of mortality from cerebrovascular disease from 1985 to 2000 were projected by a semi-logarithmic linear regression analysis based on the deaths and population by sex and age from 1973 to 1982. Crude death rates from cerebrovascular disease and cerebral hemorrhage in particular will continue to decrease but the change in death rate from cerebral infarction will remain relatively small. In the period from 1985 to 2000, the death rate from cerebral hemorrhage will decline sharply, and the death rate from cerebral infarction also is expected to decline steadily in every age group. These declines will lead to the decrease in age-adjusted death rates from these cerebrovascular diseases. The average change in the number of the deaths from 1982 to 2000 is minus 3.7% per year for cerebral hemorrhage and plus 0.8% per year for cerebral infarction. The slight increase in deaths from cerebral infarction will be due primarily to an increase in the over 80 year old population. As a result, the proportion of the deaths from cerebral infarction among all types of cerebrovascular diseases will continue to increase in Japan. These future declining trends hopefully can be further modified by improvement in dietary habits and better treatment of high risk groups.

Adolescent↗

Sex-steroid-binding plasma protein (SBP), testosterone, oestradiol and dehydroepiandrosterone (DHEA) in prepuberty and puberty.

Measurement of sex-steroid-binding plasma protein in serum of healthy individuals in prepuberty and puberty (74 males and 94 females) was performed using a radioimmunoassay procedure. An age-related decrease of serum SBP was demonstrated during these ages in both sexes. In parallel studies, the serum level of testosterone, oestradiol and dehydroepiandrosterone was evaluated in subjects under 20 years of age. A rise of serum dehydroepiandrosterone levels in both sexes was observed to occur at approximately 8 years of age, being a little bit earlier than the ages for testosterone to rise in males and for oestradiol to rise in females, both of them being at about 10 years of age, respectively. When the testosterone/sex-steroid-binding plasma protein ratio was evaluated as an index of free testosterone concentration in serum, a sharp increase of the ratio was found to occur at 10 years of age and to continue during puberty in both sexes with more marked increment in males than in females. It was suggested that the decrease of SBP in puberty might be largely influenced by alteration in the hormonal balance of testosterone, oestradiol and dehydroepiandrosterone.

Adolescent↗

Monoclonal antibodies to discrete regions in alpha 2-plasmin inhibitor.

Three monoclonal antibodies to alpha 2-plasmin inhibitor (alpha 2PI) were characterized. The first, JTPI-1, was directed against the reative site of alpha 2PI and inhibited antiplasmin activity by interfering with the formation of alpha 2PI-plasmin complexes. The avidity of JTPI-1 to the preformed alpha 2PI-plasmin complex was markedly lower than that to free alpha 2PI, which made this antibody useful for measuring the free alpha 2PI in plasma. The second, JTPI-2, recognized an epitope in the C-terminal fragment of alpha 2PI (11,000 daltons [11 K]) that was cleaved from alpha 2PI by plasmin upon complex formation but remained noncovalently attached to the complex. However, binding of JTPI-2 to alpha 2PI was not inhibited by the C-terminal 26-residue peptide containing the plasminogen-binding site and had no effect on the function of alpha 2PI. These data suggested that JTPI-2 recognized an epitope between the C-terminal 26-residue peptide and the reactive site. The third, JTPI-3, bound the alpha 2PI-plasmin complex (150 K) as well as alpha 2PI. Binding was inhibited by the N-terminal 12-residue peptide of alpha 2PI, but factor XIII-catalyzed cross-linking of alpha 2PI to fibrin was not inhibited by JTPI-3. These results suggested that the antibody recognized an epitope near the N terminus. These three monoclonal antibodies were useful for analyzing the mechanism of interaction between alpha 2PI and plasmin.

Antibodies, Monoclonal↗

Breakpoints in Philadelphia chromosome (Ph1)-positive leukemias.

We studied chromosome 22 breakpoints in 24 Philadelphia (Ph1)-positive leukemias. Nineteen of 21 patients with chronic myelogenous leukemia (CML) possessed a chromosomal break within the 5.8 kilobase (kb) breakpoint cluster region (bcr). Furthermore, in one of three cases of acute lymphocytic leukemia (ALL), we found a chromosomal rearrangement in the bcr locus. No chromosomal rearrangements were found in two cases of CML and two cases of ALL using several restriction enzymes. The bcr rearrangement is highly specific for CML. Further analyses will be necessary to determine whether some cases without bcr rearrangement have another specific locus of rearrangement. Two of three cases of CML with blastic crisis had rearrangement of the immunoglobulin gene and T-cell receptor gene. One CML patient with blastic crisis, who achieved complete remission but relapsed thereafter, was found to have the same immunoglobulin gene rearrangement in the blastic crisis and relapse phases, suggesting that the same clone was involved in both crisis and relapse.

Bacterial Proteins↗

Enhancement of the B-cell response to Staphylococcus aureus Cowan strain 1 by natural human gamma interferon.

The effects of interferon (IFN) on the B-cell response to Staphylococcus aureus Cowan strain 1 (SAC) were studied comparatively with natural human IFN-alpha, IFN-beta, and IFN-gamma, employing equal units of their anti-viral activity. First, the response was investigated in peripheral mononuclear cells obtained from healthy individuals, and next, confirmed in cultures employing B-cell enriched populations derived from tonsils obtained at tonsillectomy from patients with chronic tonsillitis. B cells were purified by rosetting out T cells with sheep red cells followed by the removal of adherent cells on a plastic surface. The results show that the SAC-stimulated lymphoproliferative response was enhanced in the presence of IFN-gamma in a dose-related manner, at concentrations ranging from 10 to 1000 IU/ml, both in peripheral mononuclear cells and tonsillar B-cell enriched fractions. In contrast, IFN-alpha and IFN-beta did not enhance or suppress SAC-stimulated blastogenesis in either lymphocyte preparation. The enhancing effects specific to IFN-gamma were more remarkable in cultures stimulated with a suboptimal dose (0.002%) of SAC than when the optimal dose (0.005%) was employed.

Antigens, Bacterial↗