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Biomedical subjects

K Aoki

Publications and source records attributed to K Aoki.

At least 433 records · Page 24Linked to original sources
PubMed1995

[Postoperative abdominal lymph node recurrence of intrathoracic esophageal cancer with a long-term complete response to radiation and split CF therapy (CDDP and 5-FU)--a case report].

We experienced complete remission in a patient with postoperative abdominal lymph node recurrence of intrathoracic esophageal cancer after treatment with radiation (60Co: 30 Gy) and split CF therapy (CDDP: 20 mg/day + 5-FU: 1 g/day for 5 days). Since then, this patient has remained in complete remission for 43 months with intermittent split CF therapy one or two times a year.

Abdomen↗
PubMed1995

[The development of a tissue calcium-detecting apparatus].

Calcium phosphate is deposited in tissues with progression of aging and arteriosclerosis, causing impairments of organ functions. Localization and quantification of tissue calcium phosphate are important for elucidation of the cause of this calcium phosphate deposition. Tissue calcium phosphate has been detected by Von Kossa-Nishiyama staining using the heavy metal substitution technique. By this method, however, the reaction was weak because of the use of sunbeam as the light source, and consistent detection was difficult. Especially, fine calcium phosphate granules that appear in early stages of the pathological changes could not be detected. Therefore, we evaluated a method for preparation of tissue specimens, light source, filter, and staining conditions, and developed a more reliable method for detection and assay of tissue calcium phosphate. The human aortic tissue was fixed with formalin, embedded with paraffin, and cut to a thickness of 4 microns using a glass knife. Solax-XCA100B, an artificial sunbeam lamp with a spectrum nearly identical with that of the sun, was used as the light source. A B filter, which selectively filters out the wavelengths 290nm or less and 800-1,000nm, was used. The appearance of abnormal granules due to excessive reaction could be prevented by eliminating ultraviolet rays with wavelengths of 290nm or less, and burning of the tissue and the appearance of silver particles could be prevented by excluding infrared rays with wavelengths of 800nm or above. Distilled water was continuously dripped into the reaction solution to prevent an increase in the concentration due to evaporation. The reaction showed appreciable progression until after 40 minutes and stopped completely after 80 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1995

[Cataract epidemiology survey in the three climatically different areas in Japan--prevalence of cataracts and types of lens opacification].

A cataract epidemiology study of 1,615 subjects from three climatically different places in Japan, village S in Hokkaido, town M in Noto and village Y in Okinawa, was conducted by one study group. Cataract diagnosis and grading of cataracts were objectively done with a photo-documentation system. The percentages of cataracts of over grade I classified by the Japanese Cooperative Cataract Epidemiology Study Group were 46.6%, 64.6% and 38.0% in village S, town M, and village Y, respectively. Those in their 50s, 60s, and 70s in the above places were 24.3%, 51.1% and 71.4% (village S), 38.4%, 65.3% and 84.6% (town M), and 25.2%, 42.9% and 65.4% (village Y), respectively. Cortical cataract was the most common, followed by nuclear and subcapsular types. Although the highest percentage of nuclear cataracts was seen in the subjects of village Y, subcapsular cataract was seen almost equally in the three areas. Lens transparency changes were evaluated by the light scattering intensities in the lens layers through photographed images. Intensity increased with ageing either linearly or exponentially.

Adult↗
PubMed1995

[Progression of senile aortic valve calcification: echocardiographic and clinical assessment].

Factors involved in the progression of senile aortic valve calcification were evaluated by analyzing the clinical and echocardiographic characteristics of patients older than 69 years with senile aortic valve calcification. The patients were divided into three groups; group 1: 46 male and 40 female patients with calcification of one cusp and almost normal pliability of three cusps, group 2: 48 males and 55 female patients with calcification of two or three cusps, mildly reduced pliability of calcified cusps, and aortic valve area (AVA) > or = 2.0 cm2, group 3: 26 male and 31 female patients with calcification of two or three cusps, significantly reduced pliability of calcified cusps, and AVA < or = 1.5 cm2. There were no significant differences in age, weight, height, left ventricular dimension, or left ventricular wall thickness between these three groups. For male patients, the end-diastolic maximum left ventricular outflow tract dimensions (LVOT) in groups 1, 2, and 3 were 20 +/- 2 mm, 19 +/- 2 mm (p < 0.01 vs group 1), and 17 +/- 3 mm (p < 0.001 vs group 1, p < 0.01 vs group 2), respectively. For female patients, the LVOTs of groups 1, 2, and 3 were 18 +/- 2 mm, 16 +/- 2 mm (p < 0.001 vs group 1), and 16 +/- 2 mm (p < 0.001 vs group 1), respectively. Reduction in LVOT was not associated with left ventricular hypertrophy or decrease in dimension of aortic annulus. In female patients, the frequency of mitral annular calcification of group 3 was 61% [p < 0.05 vs group 1 (35%), p < 0.01 vs group 2 (25%)].(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Rapid diagnosis of adenoviral conjunctivitis by enzyme-linked immunosorbent assay (Adenoclone)].

We evaluated an enzyme-linked immunosorbent assay test (Adenoclone) for the rapid diagnosis of adenovirus infection in 589 cases of acute follicular conjunctivitis. Of 255 cases of adenoviral conjunctivitis proven by positive virus isolation. Adenoclone was positive in 51.0% by visual determination and 40.4% by spectrophotometry. Twenty-seven of 130 cases giving visually positive results were interpreted to be negative by spectrophotometry. In 334 adenovirus-negative cases, Adenoclone was negative in 99.1% and 99.4 by visual and spectrophotometric determination, respectively. Adenoclone was less sensitive in cases of adenovirus 3, 4 or 37, infections than in those of adenovirus 8, and also showed lower sensitivity in cases presenting mild conjunctivitis. Adenoclone is a rapid and easy test with high specificity but low sensitivity, and thus the test seems to be helpful in diagnosing adenoviral conjunctivitis.

Adenovirus Infections, Human↗
PubMed1995

[Histological evaluation of bronchial tissue from elderly individuals with bronchial asthma].

We studied morphologic and morphometric characteristics of the bronchial walls in lungs obtained at autopsy form elderly patients who had had bronchial asthma. Thirteen patients (age at time of death 57 to 98 years; average, 81 years) were divided into three groups: AS, died of severe asthma attack (n = 4); AC, admitted with asthma symptoms but died of other diseases (n = 6); and NA, died of other diseases and had had no asthma symptoms in the year before death (n = 3). Lungs from ten non-smokers with no history of bronchial asthma or other lung disorders were used as control. Transverse sections of segmental and subsegmental bronchi were prepared, and four quantities were analyzed: 1) the ratio of total bronchial gland area to total area of the bronchial wall (Yamanaka index), 2) the thickness of the basement membrane, 3) the thickness of the smooth muscle bundle, and 4) the ratio of luminal area to total area of the bronchial wall (bronchial dilation ratio). In the AS group, the Yamanaka index and the thickness of the smooth muscle bundles and of the basement membrane were significantly greater than those in the control group at both the segmental and subsegmental levels, with massive eosinophil infiltration into the bronchial walls. Furthermore the bronchial dilation ratio at the subsegmental level correlated closely with the Yamanaka index. Thickness of the smooth muscle bundle seemed to be most representative of the severity of asthma symptoms. In conclusion, morphometric findings of bronchial walls in elderly patients with asthma symptoms seem to be similar to those in their younger counterparts.

Age Factors↗
PubMed1995

Clear cell variants of intracranial tumors: meningioma and ependymoma.

We report two cases of rare histological types of intracranial clear cell tumor. Case 1: The tumor, on the left frontal convexity in a 64-year-old woman, consisted largely of polygonal cells with clear cytoplasm which were divided into lobules of uneven size by abundant fibrous connective tissue. Most of the tumor cells were immunopositive for epithelial membrane antigen and vimentin. Ultrastructurally, the tumor cells showed conspicuous interdigitations of their plasma membranes with frequent junctional complexes, and contained numerous glycogen granules in the cytoplasm and its processes. Occasionally, amianthoid collagen fibers were found in the fibrous stroma. Our diagnosis of this tumor was clear cell meningioma. Case 2: The tumor, in the right cerebellar hemisphere in a 64-year-old woman, consisted of round, clear cells with a honeycomb-like pattern. The tumor cells were positive for glial fibrillary acidic protein, vimentin and S-100 protein. Ultrastructurally, the tumor was composed of round cells arranged in a cell-to-cell pattern, and the adjacent cells often formed microrosettes containing microvilli in their lumina. There were scattered cells with accumulatios of glycogen granules in their cytoplasm. Our diagnosis of this tumor was clear cell ependymoma. From the light microscopic features of these tumors, it does not necessarily seem easy to discriminate them from other intracranial tumors composed of similar clear cells, such as oligodendroglioma, central neurocytoma, hemangioblastoma and metastic renal cell carcinoma. Ultrastructural examination is crucial in the identification of the clear cell variants of meningioma and ependymoma.

Brain Neoplasms↗
PubMed1994

Activation mechanism of NADPH oxidase by SDS in intact guinea pig neutrophils.

It is well known that sodium dodecyl sulfate (SDS) activates NADPH oxidase in a cell-free system independently of protein kinase C (PKC). However, in intact neutrophils, direct evidence has never been presented to show that O2- production by SDS is actually due to the NADPH oxidase activation observed in the cell-free system. So, in this paper, we investigated the activation mechanism by SDS in intact guinea pig neutrophils. We previously reported that hypotonic treatment reversibly enhanced O2- production stimulated by PKC activators in intact neutrophils (M. Hiura et al., 1991, Arch. Biochem. Biophys. 291, 31-37). In this paper, SDS also significantly stimulated O2- production in the intact cells under the hypotonic condition. This enhancement was gradual and was PKC inhibitor resistant. Furthermore, phosphorylation of the 46-kDa protein, one of cytosolic activation factors, was not detected by autoradiography of two-dimensional electrophoresis. Translocation of cytosolic activation factors was demonstrated by a decrease in the activity of the factors remained in the cytosol. In the presence of SDS, addition of 1-oleoyl-2-acetylglycerol, a PKC activator, further enhanced O2- production and translocation of the cytosolic activation factors. On the other hand, SDS remarkably increased membrane fluidity in intact neutrophils as well as in the cell-free system. These results indicate that activation of NADPH oxidase by SDS in intact neutrophils seems to be partly due to the same mechanism observed in cell-free activation, and that SDS alone slightly activates the oxidase and other stimulation, such as hypotonic and/or PKC activator treatments, is required for significant activation. The increase in the membrane fluidity may be one of the activation mechanisms of NADPH oxidase by SDS.

Animals↗
PubMed1994

Characteristic effects of activated human protein C on tissue thromboplastin-induced disseminated intravascular coagulation in rabbits.

Protein C (PC) is the zymogen of an anticoagulant serine protease and is converted to its active form (activated protein C: APC) by thrombin in the presence of thrombomodulin. APC plays an important role in regulating thrombosis and fibrinolysis by inhibiting not only blood coagulation factors Va and VIIIa but also type-1 plasminogen activator inhibitor (PAI-1). In the present study we examined the effects of human APC on tissue thromboplastin-induced disseminated intravascular coagulation (DIC) in rabbits and compared them with those of heparin. Both APC (300-3000 U/kg) and heparin (100-300 IU/kg) inhibited the decreases in platelet count and fibrinogen level equally. APC improved the prolonged bleeding time, but heparin aggravated bleeding with potent prolongation of activated partial thromboplastin time (APTT). Furthermore, in APC-treated animals, fibrin deposition in glomeruli was less than in heparin-treated animals. This result that APC accelerated local fibrinolysis by neutralizing PAI-1. From our findings, we concluded that APC can improve both coagulation and fibrinolysis in a DIC model and should be useful for the clinical remedy of DIC without having an adverse side effect like a bleeding tendency.

Animals↗
PubMed1994

Sodium benzylideneascorbate induces apoptosis in HIV-replicating U1 cells.

U1 cells, a subclone of U937 cells chronically infected with human immunodeficiency virus type 1 (HIV-1), produced HIV-1 only in the presence of inducers such as 12-O-tetradecanoxylphorbol 13-acetate (TPA) or tumor necrosis factor (TNF)-alpha. The expression of HIV-antigen on U1 cells induced by TPA or TNF-alpha was found to be prevented by sodium 5,6-benzylidene-L-ascorbate (SBA) in a concentration-dependent manner. Treatment of U1 cells with SBA in the presence of inducers resulted in cell death with cell shrinkage, chromatin condensation and DNA fragmentation into nucleosomal oligomers, characteristics of apoptosis. In contrast, SBA had scarcely any apoptotic effect on U1 cells in the absence of inducers. SBA did not also induce apoptosis in parental U937 cells in the presence or absence of inducers. These results suggest that HIV-replicating U1 cells selectively undergo apoptosis on treatment with SBA.

Antiviral Agents↗
PubMed1994

Nucleolar organizer regions in small nodular lesions representing early stages of human hepatocarcinogenesis.

BACKGROUND: It is believed that in the early stages of hepatocarcinogenesis, some adenomatous hyperplasias (AH) progress to early hepatocellular carcinoma (eHCC), and that many eHCC develop into overt hepatocellular carcinoma (HCC) through nodule-in-nodule formation. However, the proliferative activity of these small nodular lesions has not been fully investigated. METHODS: Cell proliferative activity was assessed by counting nucleolar organizer region-associated proteins (Ag-NOR) in paraffin sections of 12 AH nodules, 25 eHCC nodules, and 8 nodule-in-nodule lesions. In nodule-in-nodule lesions, an area of well-differentiated HCC corresponding to eHCC and a discrete inner nodule area composed of obvious HCC were examined. RESULTS: Mean Ag-NOR numbers of extranodular parenchyma, AH, and eHCC were 1.35, 1.35, and 1.75 (P < 0.01), respectively. With regard to the relative Ag-NOR number compared with that of parenchyma, there was no overlap between AH and eHCC with a border of 1.1-fold except in one specimen. In nodule-in-nodule lesions, the mean Ag-NOR number (2.53) in the inner nodular area was much higher (P < 0.01) than that of the area of eHCC (mean, 1.88). CONCLUSIONS: A stepwise increment of Ag-NOR number was demonstrated in accordance with the multistep of the AH to eHCC to nodule-in-nodule lesion sequence of hepatocarcinogenesis. Thus, it was proposed that the Ag-NOR count may be a practical and objective parameter for assessing the malignant potential of hepatocellular neoplasms histopathologically.

Aged↗
PubMed1994

Cultural transmission of a sign language when deafness is caused by recessive alleles at two independent loci.

Two unlinked autosomal loci are assumed to affect the ability to hear in such a way that homozygosity for the recessive allele at either locus causes deafness. The five deaf genotypes are subject to the same negative selection due to a lower likelihood of marriage, but unmarried deaf persons remain socially active and participate in the cultural transmission of sign languages. Marriages are assortative for deafness or for hearing, and mutation occurs irreversibly from the dominant to recessive allele at each locus at the same rate. At mutation-selection balance, the fully polymorphic equilibrium is symmetrical. Based on this genetic model, we consider the relative importance of various forms of cultural transmission as they affect the persistence of sign languages. Horizontal transmission is shown to be effective when deaf children are able to interact with many peers. This observation is especially pertinent if assortative meeting of deaf children occurs, for example, at schools for the deaf. Oblique transmission can also be effective, but the literature suggests that this kind of transmission plays only a minor role. It is necessary, however, that some form of cultural transmission occur between generations. Thus, vertical transmission is a critical factor, despite the fact that parent-child transmission is often interrupted due to the recessive inheritance of deafness. In particular, the contribution of vertical transmission is enhanced by assortative mating for deafness.

Child Development↗
PubMed1994

Phase advances of circadian rhythms in somatostatin depleted rats: effects of cysteamine on rhythms of locomotor activity and electrical discharge of the suprachiasmatic nucleus.

Somatostatin is synthesized in the suprachiasmatic nucleus (SCN), a circadian pacemaker in mammals. To explore the functional significance of somatostatin in the circadian system, we examined rhythms of rat locomotor activity and electrical firing rate of SCN neurons in the brain slice after temporal depletion of somatostatin levels in the SCN. Intraperitoneal administration of cysteamine (200 mg/kg), a somatostatin depletor, significantly reduced somatostatin level in the in vivo SCN 5 min after injection and kept low level as long as 3 to 4 days. This administration, on the other hand, induced significant phase advances of about 51 min in the subsequent free-running rhythm of locomotor activity of the rat. A marked phase advance in the circadian rhythm of firing rate in the SCN was also observed after administration of cysteamine in coronal hypothalamic slices. These persistent phase shifts after administration of a somatostatin depletor may suggest that the change of somatostatin level in the SCN have a feedback influence on the circadian pacemaker.

Animals↗
PubMed1994

Isolation and characterization of a novel mutant mouse cell line resistant to Newcastle disease virus: constitutive interferon production and enhanced interferon sensitivity.

In our attempt to isolate mutant cell lines resistant to Newcastle disease virus (NDV) we developed an improved procedure for enrichment of NDV-resistant cells from mouse FM3A cells and isolated a novel NDV-resistant mutant cell line, Had-2, with characteristics different from Had-1, a previously reported NDV-receptor-deficient mutant strain. Had-2 cells adsorbed NDV normally but the accumulation of viral mRNAs and proteins was inhibited. Had-2 cells had to be grown at higher cell densities in order to be NDV-resistant, and it was revealed that they did not exhibit NDV-resistance when grown at lower cell densities. A conditioned medium prepared from a culture of Had-2 cells grown at high cell density was able to make a low-density culture NDV-resistant. The activity of the conditioned medium to induce NDV-resistance was completely neutralized by addition of both anti interferon (IFN)-alpha and anti IFN-beta antibodies, indicating that Had-2 cells were constitutively releasing IFNs, though their levels were rather low. Had-2 cells were also characterized by an increased sensitivity to IFNs as compared with the parental FM3A cells, since the conditioned medium containing IFNs did not render FM3A cells resistant to NDV.

Animals↗
PubMed1994

Postoperative changes in plasma tissue-type plasminogen activator and type 1 plasminogen activator inhibitor.

To clarify the changes which occur postoperatively in intravascular fibrinolysis, plasma levels of tissue-type plasminogen activator (t-PA) antigen, the total plasminogen activator inhibitor type-1 (PAI-1) antigen, and the t-PA-PAI-1 complexes were assayed in this study. Blood samples were taken the morning before surgery, then at 0, 12, 24, 36, 60, 108, and 156 h postoperatively in ten patients who underwent radical surgery for thoracic esophageal cancer. The plasma levels of the t-PA and total PAI-1 antigens, and the t-PA-PAI-1 complexes were then measured by enzyme immunoassay. The plasma t-PA and total PAI-1 levels increased significantly in the immediate postoperative period, the percent increase of the latter being much greater than that of the former. Moreover, the calculated free t-PA antigen level was decreased throughout the postoperative period, suggesting postoperative hypofibrinolysis. The platelet count and neutrophil elastase level were significantly correlated with the free t-PA antigen level at r = 0.630, P < 0.001, and r = -0.447, P < 0.01, respectively. The results of this study indicated that post-operative hypofibrinolysis caused by the increased synthesis of PAI-1 may enhance postoperative hypercoagulability, and this may lead to the development of organ damage. Thus, the concentration of the PAI-1 antigen may be a potentially important index for the prediction of postoperative illness.

Aged↗