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Biomedical subjects

S Hashimoto

Publications and source records attributed to S Hashimoto.

At least 91 records · Page 5Linked to original sources
PubMed1991

Early gastric cancer arising from localized Ménétrier's disease.

A case of early gastric cancer arising from Ménétrier's disease in the stomach is described. The patient was a 53-year-old man, who suffered from epigastralgia. Radiological and endoscopic examination demonstrated giant mucosal folds along the greater curvature of the stomach. On the distal margin, signet-ring cell carcinoma was demonstrated by biopsy. The coexistence of Ménétrier's disease and early gastric cancer has rarely been reported. Cases reported in the literature were reviewed and the increased malignant potential of Ménétrier's disease was discussed.

Adenocarcinoma↗
PubMed1991

Pallido-nigro-luysian atrophy, progressive supranuclear palsy and adult onset Hallervorden-Spatz disease: a case of akinesia as a predominant feature of parkinsonism.

Few parkinsonian patients present with 'pure akinesia' or with severe akinesia accompanied by only mild rigidity, tremor and other manifestations such as ophthalmoplegia. Pathological examinations of such cases have rarely been conducted and have revealed findings compatible with progressive supranuclear palsy (PSP), pallido-nigro-luysian atrophy (PNLA) or Parkinson's disease. We report a parkinsonian patient whose main clinical feature was akinesia. A postmortem study of this patient showed findings corresponding to PNLA and PSP. Histochemical properties of the pallidal pigment granules were equivalent to those of Hallervorden-Spatz disease (HSD) and striatonigral degeneration. In addition to iron-positive pigment granules, spheroids, severe neuronal loss and gliosis in the globus pallidus and substantia nigra, formation of Alzheimer's neurofibrillary tangle (NFT) in the brainstem shares characteristics with PSP, adult onset HSD and PNLA. We suggest that the underlying pathology of 'pure' akinesia is most often situated in the globus pallidus substantia nigra and subthalamus (Luys), and that PSP, PNLA and adult onset HSD may constitute a spectrum of one disease.

Atrophy↗
PubMed1991

Extensive proliferation of peripheral type myelin in necrotic spinal cord lesions of multiple sclerosis.

Peripheral type "remyelination" in the spinal cord was investigated in a 34-year-old woman with relapsing multiple sclerosis (MS) over 7 years following her initial presentation with myelopathy. Confined to the large necrotizing cord lesions involving the gray matter, there was prominent proliferation of peripheral type myelin, measuring up to one-third of the cross-sectional field of the cord. These nerve bundles with peripheral type myelin, which was devoid of glial fibrillary acidic protein immunoreactivity, consisted of relatively monotonous, small-caliber nerve fibers arranged in parallel along the long axis of the cord. The ratio of the myelin thickness to axonal diameter was not as small as that of the ordinary remyelination. Co-existing abundant neuroma formation indicated exuberant regenerative activity of the peripheral nerves. These findings suggest that the peripheral nerve fibers with their axons originating from nerve roots may enter the necrotic MS cord lesions in such a way as to manifest in spinal cord trauma. Relatively frequent occurrence of this extensive proliferation of peripheral type myelin in Japanese MS subjects appears to be related to the severity of tissue destruction experienced in Japanese as compared with that of occidental MS.

Adult↗
PubMed1991

Analysis of antitumor effects of OK-432 against syngeneic mouse fibrosarcoma: combination effect of OK-432 and recombinant lymphokines.

OK-432, a streptococcal preparation with potent biological response modifying activities, had the ability to cure mice bearing BAMC-1 (fibrosarcoma) ascites when it was injected intraperitoneally five times, 2, 4, 6, 8, and 10 days after the tumor inoculation. Previously, it was shown that the OK-432 injection on day 2 was indispensable since only a minimal antitumor effect was obtained when an inflammation-inducing agent such as thioglycolate instead of OK-432 was injected on day 2, followed by four OK-432 injections on days 4, 6, 8 and 10. In the present study, the injection of OK-432 on day 2 and a subsequent injection of either IL-2 or IFN-gamma on day 4 or 6 showed a significant antitumor effect, achieving a complete cure in approximately 50% of mice treated, although none of the mice could be cured by a single injection of either OK-432, IL-2, or IFN-gamma on day 2. Interestingly, however, the mice treated with an injection of a lymphokine (IL-2 or IFN-gamma) on day 2 followed by OK-432 on day 4 were not cured either. Peritoneal cells on day 12 in mice treated with OK-432 and either of the lymphokines contained pantropic killer cells, which were Thy-1+ and asialo GM1+ (AsGM1+). Moreover, the antitumor effect of the combined treatment was abolished when mice were pre-treated with anti-AsGM1. No significant antitumor effect was observed in athymic nu/nu mice. Together with our previous findings, these results indicate that lymphokines induced by OK-432 administration may account for some of its therapeutic effects and that these lymphokines may also facilitate the subsequent induction of specific killer cells. These results warrant further investigation on possible effective therapeutic protocols with the combined use of OK-432 and lymphokines.

Animals↗
PubMed1991

High dose rate intracavitary brachytherapy for recurrent cervical cancer of the vaginal stump following hysterectomy.

Forty-eight patients with recurrent cervical cancer of the vaginal stump following hysterectomy for cervical cancer, were treated with high dose rate intracavitary brachytherapy with or without external irradiation. The intervals between primary surgery and vaginal recurrences varied widely from 3 months to 36 years. Patients were classified into two groups, either with or without palpable tumor of the vaginal stump. Tumor size was determined by bimanual rectovaginal examination at the time of recurrence. Survival rates were 8% for the group with palpable tumors and 80% for those without, respectively. The survival rate of patients who did not have palpable masses and were treated with brachytherapy alone was not improved by combination with external irradiation. The time interval from the primary hysterectomy to the recurrence did not influence survival. These results suggest that the only significant prognostic factor for recurrent cervical cancer after hysterectomy is tumor size. The relationship between recurrent cervical cancer of the vaginal stump and second primary vaginal cancer is also discussed.

Adult↗
PubMed1991

Changes in 40 serum proteins of post-menopausal women.

Sera were sampled from 83 people (pre- and post-menopausal women and men). Climacteric symptoms of 23 women were treated with conjugated estrogen. Sera were sampled serially until the 21st day of estrogen administration. Serum concentrations of 40 protein components were measured by micro single radial immunodiffusion. The serum proteins were classified into 5 types according to changes after menopause and estrogen therapy, respectively. Type 1 (decreased after menopause and increased by estrogen; alpha 1-antitrypsin, alpha 2-HS - glycoprotein, beta 2-glycoprotein III, Gc-globulin, alpha 1-lipoprotein and alpha 2-AP-glycoprotein), type 2 (unchanged and increased; ceruloplasmin), type 3 (increased and decreased; alpha 1-acid glycoprotein, haptoglobin, serum amyloid P-component, Zn-alpha 2-glycoprotein, beta-lipoprotein and C1-components), type 4 (unchanged and decreased; hemopexin, antithrombin III, beta 2-glycoprotein I, prealbumin and retinol-binding-protein), type 5 (unchanged by estrogen; immunoglobulin M (IgM), IgG and others). Estrogen replacement therapy restored pre-menopausal levels of serum proteins, types 1 and 3. However, estrogen therapy was associated with significantly abnormal levels of proteins, types 2 and 4 in post-menopausal women. Serum levels of type 1 proteins and some type 5 proteins (IgM, alpha 1B-glycoprotein, C9-component and alpha 2-macroglobulin) were higher in pre-menopausal women than in men, whereas type 3 proteins were the opposite.

Adult↗
PubMed1991

The E1b oncogene of adenovirus confers cellular resistance to cytotoxicity of tumor necrosis factor and monoclonal anti-Fas antibody.

The cell lines KB8, 16, and 18 are KB cells which constitutively express adenovirus type 2 (Ad2) E1a, E1a plus E1b, and E1b genes, respectively. We show here that KB18 cells are completely resistant to cytolysis by tumor necrosis factor (TNF) or anti-Fas, although KB8 and KB or KB16 are highly and moderately sensitive, respectively. The levels of receptors for TNF and anti-Fas of KB18 were almost the same as compared with those of KB or other KB-cell lines. Expression of manganous superoxide dismutase (MnSOD) mRNA in KB18 was about 20-fold higher than that in KB or KB8 cells. KB, HT29, and A673 cells infected with dl337 (an Ad5 mutant defective in E1b function) are highly sensitive to TNF or anti-Fas, although wild-type Ad2-infected cells are resistant. Our results indicate that the E1b oncogene can confer cellular resistance to cytolysis by either TNF or anti-Fas in both KB cells and adenovirus-infected human cell lines through influencing intracellular events including regulation of MnSOD genes. Furthermore, we describe how anti-Fas mimics only the cytolytic activity of TNF, whereas TNF also has many other biological activities.

Adenoviruses, Human↗
PubMed1991

Mechanism of calcium ionophore and phorbol ester-induced T-cell activation. Accessory cell requirement for T-cell activation.

We examined the role of monocytes in T-cell activation induced by phorbol myristate acetate (PMA) and calcium ionophore ionomycin. Depletion of monocytes from peripheral blood mononuclear cells (PBMC) was associated with the loss of interleukin-2 (IL-2) production, IL-2 receptor (IL-2R) expression and proliferation, in response to either PMA or ionomycin. Addition of monocytes to highly purified T cells resulted in the complete reconstitution of IL-2 production, IL-2R expression and proliferation by PMA-stimulated lymphocytes. Exogenous IL-2, but not interleukin-1 (IL-1), could reconstitute the T-cell responsiveness. Addition of monocytes to highly purified T cells stimulated with ionomycin resulted in partial reconstitution of IL-2 production, IL-2R expression and proliferation. Similarly, the addition of exogenous IL-2 to ionomycin-stimulated T cells only partially reconstituted the response compared with PBMC. These results suggest that monocyte-T-cell interactions contribute to IL-2 production and IL-2R expression and are crucial events for PMA-induced T-cell proliferation. With ionomycin, monocytes play a role, in part, in inducing IL-2 production, IL-2R expression and proliferation. However, IL-2 is not a sufficient signal to induce T-cell proliferative response to ionomycin, suggesting that an IL-2-independent mechanism may exist in ionomycin-induced T-cell proliferation.

Cell Division↗
PubMed1991

Vacuoles and vesicles in the rat junctional epithelium: a study with serial ultrathin sections.

To investigate whether the electron-lucent structures resembling vesicles and vacuoles in the rat molar junctional epithelium (JE) are in fact intracellular or extracellular, a study using serial ultrathin sections was carried out. In one series of experiments, the animals were not treated before the tissues were conventionally fixed; in another, anesthetized animals were administered horseradish peroxidase 20 min before the tissues were fixed. A large number of electron-lucent structures resembling vesicles and vacuoles were detected in both the peripheral and central cytoplasm of the JE localized at enamel and connective tissue sites. These were 70 to 800 nm in diameter and had a lucency similar to that of the extracellular space in untreated specimens fixed with conventional fixative. Serial ultrathin sectioning revealed that the electron-lucent structures gradually became part of the extracellular space in the following sections. There were also found in the middle portion of the cytoplasm in specimens pretreated with horseradish peroxidase. Numerous vacuole-like structures containing peroxidase-positive materials were found to be contiguous with the extracellular space. A small number of vesicles, also containing peroxidase-positive materials, did not appear in the previous or following sections. These results indicate that almost all electron-lucent structures resembling vesicles and vacuoles in the JE are located at the end of a long infolding, and are still in contact with the extracellular space.

Animals↗
PubMed1991

Cholera enterotoxin production in Vibrio cholerae O1 strains isolated from the environment and from humans in Japan.

Vibrio cholerae O1 strains isolated from various sources in Japan over the years 1977 through 1987 were examined to confirm the presence or absence of the cholera enterotoxin (CT) gene and production of CT and to determine the kappa-phage type. The CT gene was detected in none of 225 isolates from natural waters but was present in all of the 10 isolates from environmental waters implicated in domestic cholera cases, in 64 strains (26.6%) of the 241 isolates from imported seafoods, in 43 strains (95.6%) of the 45 isolates from domestic cholera cases, and in 119 strains (93.7%) of the 127 isolates from imported cholera cases. The results suggest that the CT gene-positive strains of V. cholerae O1 have been imported into Japan through seafoods and/or by travelers. Sporadic cholera cases have resulted in contamination of the surrounding environment, but the CT gene-positive strains may not have persisted in natural waters to serve as a reservoir for epidemic cholera. The commercially available VET-RPLA kit (a latex agglutination kit for immunological detection of CT) detected production of CT in all of the CT gene-positive strains, indicating that there was no silent CT gene in the test strains. There was a strong correlation between the kappa-phage type and the presence or absence of the CT gene, suggesting a significant clonal difference between CT gene-positive and -negative strains. Five CT gene-negative strains isolated from imported cholera cases (travelers with mild diarrhea) induced a considerable amount of fluid accumulation in rabbit and/or suckling mouse intestines, indicating production of an enterotoxic factor(s) other than CT.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Fastidious human adenovirus type 40 can propagate efficiently and produce plaques on a human cell line, A549, derived from lung carcinoma.

Human adenovirus type 40 (Ad40) cannot propagate in conventional established human cell lines such as KB or HeLa cells. However, it has been shown that Ad40 DNA replicates in KB18 cells which express Ad2 E1B genes, suggesting that Ad40 is defective in the E1B gene function in KB or HeLa cells. We show here that Ad40 can propagate and produce plaques on A549 cells which do not contain Ad E1B genes. Our experiments show that the levels of replication of Ad40 DNA and production of infectious Ad40 virus in A549 cells are the same as or higher than those in 293 or KB18 cells. Dot blot analysis shows that the levels of Ad40 E1A and E1B mRNAs expressed in A549 cells at early to intermediate times postinfection are at least 10-fold higher than those in KB or KB18 cells. Northern (RNA) blot analysis shows that large E1B mRNA species (approximately 24S to 26S) are synthesized prior to the onset of DNA replication in A549 cells. No E1B mRNA species are synthesized in KB or KB18 cells at early times postinfection, and no differences in the expression of E1B mRNAs are seen between KB and KB18 cells. The experiment suggests that A549 cells have a cellular factor(s) which activates Ad40 E1B mRNA synthesis and that the E1B mRNA synthesis helps Ad40 propagation. In contrast, Ad40 can propagate in KB18 cells by using Ad2 E1B gene products that are constitutively expressed in this cell line. Furthermore, this result shows that Ad40 cannot propagate in KB cells because of the failure in the expression of E1B genes at early times postinfection.

Adenovirus Early Proteins↗
PubMed1991

Vascular viscoelasticity of perfused rat hindquarters.

To determine viscoelastic features of the rat hindquarters vasculature, we measured pressure-volume curves. Male Wistar rats were transected at the lumbar level, and the perfused hindquarters were oxygenated with a hollow fiber artificial lung. The blood volume was measured by counting 51Cr-labeled red cells led to a gamma counter through an extracorporeal circuit at a constant rate. With continuous monitoring of the venous pressure and circulating blood volume, saline was infused into the circuit from a venous branch for 5 min [1.2 +/- 0.3% (SD) of tissue weight] followed by a 10-min recovery phase. In the recovery phase, the venous pressure promptly declined to the preinfusion level, whereas the circulating blood volume decreased more slowly. This implied vascular stress relaxation of the hindquarters. Maxwell's viscoelastic model, consisting of a spring component and a viscous component, was applied to analyze the venous pressure-volume diagram. With a curve-fitting method, the calculated vascular compliance and relaxation time (a time constant of stress relaxation) were 1.31 +/- 0.14 ml.mmHg-1.kg-1 and 15.7 +/- 4.0 min (means +/- SE), respectively. The value of compliance of the hindquarters was smaller than those of visceral organs reported. In addition, the value for relaxation time suggests that the viscous response of the vasculature simultaneously overlaps change in blood volume due to extravascular fluid shift during the postinfusion period.

Animals↗
PubMed1991

Renal adaptation to dietary phosphate deprivation: role of proximal tubule brush-border membrane fluidity.

With dietary phosphate (Pi) restriction, fluidity of renal proximal tubule brush-border membranes (BBM) and Na-dependent Pi transport (Na-Pi) are increased, suggesting that changes in BBM fluidity are critical for adaptation to Pi restriction. To test this hypothesis, the temporal relationship between Na-Pi transport and changes in BBM fluidity was assessed after Pi deprivation in rats. Renal cortex was obtained from rats fed either a 0.03% (-P) or a 0.6% (+P) Pi diet for 4 h or 7 days, and BBM were prepared. Na-Pi uptake by BBM was measured by use of rapid filtration, and BBM fluidity was assessed by use of the fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH). After 4 h on the diets, Na-Pi uptake was 439 +/- 142 (SD) and 984 +/- 184 pmol.mg protein-1.5 s-1 in +P and -P, respectively (P less than 0.01, n, = 8). Na-dependent proline uptake was unchanged. DPH anisotropy and total cholesterol were similar between groups: 0.204 +/- 0.025 and 0.401 +/- 0.047 nmol/mg protein, respectively, in +P and 0.205 +/- 0.015 and 0.392 +/- 0.037 in -P (P greater than 0.05, n = 8-10). After 7 days, Na-Pi uptake was 841 +/- 291 in +P and 2,168 +/- 848 pmol.mg protein-1.5 s-1 in -P, P less than 0.01, n = 8. DPH anisotropy and BBM cholesterol were 0.175 +/- 0.019 and 443 +/- 132 nmol/mg protein, respectively, in +P and 0.162 +/- 0.020 (n = 8) and 341 +/- 128 (n = 3) in -P (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1991

[Systems analytical investigation of the effect of countermeasures against the AIDS epidemic among homosexuals].

In Japan, the AIDS (Acquired Immunodeficiency Syndrome) epidemic among haemophiliacs has been the most urgent issue, because of the large number of haemophiliacs with AIDS. However, after governmental approval of the production of heated coagulating agents in 1985 and 1986, the prime object of prevention against the AIDS epidemic shifted from transmission through coagulation agents to that through sexual contacts. In order to investigate the most appropriate countermeasures against the AIDS epidemic among homosexuals in Japan, the numbers of HIV (Human Immunodeficiency Virus)-infected cases and AIDS cases in the future were estimated, and changes of the future numbers of HIV-infected persons and AIDS cases by behavior of homosexuals were compared using a systems analytical method. The methods of estimation and comparison are similar to those of R. M. Anderson and others, using numerical analysis of a mathematical model consisting of differential equations. They assumed a closed homosexual group whose members seldom have contact with members of other homosexual groups, but we assumed an open homosexual group whose members are being infected by other groups, because this assumption was more appropriate to the situation of homosexual society in Japan. The results showed that the prevalence number of HIV-infected cases would be about 1,800, that the prevalence number of AIDS cases would be about 100 among 100,000 homosexuals at 20 years after the beginning of the AIDS epidemic, and that the most effective countermeasure was reducing the frequency of sexual contacts among members or taking prophylactic measures during sexual contacts. These prevalence numbers of HIV-infected cases and AIDS cases would be reduced to between 1/4 and 1/2 of the above-mentioned calculated values by promotion of that countermeasure.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Low-density lipoprotein uptake and cholesterol accumulation by cultured renal cells.

The uptake of low-density lipoprotein (LDL) and the accumulation of cholesterol were assessed in opossum kidney (OK) and Madin-Darby canine kidney (MDCK) cells. OK and MDCK cells were grown to confluency on Millicell well inserts. The uptake of human LDL across the apical and basolateral surfaces of OK and MDCK cells was assessed by the degradation of internalized (125I)LDL to trichloroacetic acid-soluble products. LDL uptake via the apical surface of OK cells increased linearly with LDL concentration, indicating nonreceptor-mediated uptake. In contrast, LDL uptake via the basolateral surface of OK cells and both apical and basolateral surfaces of MDCK cells followed a saturable pattern. In addition, (125I)LDL bound to the apical membrane of MDCK cells, but not to the apical membrane of OK cells, was displaced by heparin and by excess of unlabeled LDL. Exposure to LDL (100 mg/mL) resulted in an increase in total cholesterol content of OK and MDCK cells (23 and 18%, respectively). Most of the increase in total cholesterol content with LDL exposure resulted from increased free cholesterol content in MDCK cells and esterified cholesterol in OK cells. The differences in cholesteryl ester formation were consistent with the slower rates of (14C) oleate incorporation into cholesteryl ester and lower cholesterol esterifying activity observed in MDCK cells compared with that in OK cells. These results demonstrate that LDL uptake can be receptor or nonreceptor mediated, depending upon the renal cell type and the surface exposed to LDL, and that LDL exposure leads to increased cholesterol content in OK and MDCK cells.

Animals↗
PubMed1991

Regulation of vascular compliance and stress relaxation by the sympathetic nervous system.

We measured the changes in central venous pressure (CVP) and circulating blood volume (CBV) in dogs consequent to fluid infusion under halothane anesthesia, and compared the CVP and CBV responses to those obtained after blocking the autonomic nervous system by total spinal anesthesia (TSA) and stimulating the alpha receptor with methoxamine (MTX). Under TSA, the change in CVP consequent to fluid infusion was less than that under halothane anesthesia, while with MTX, the change in CVP was larger than that under halothane anesthesia. The recovery time of CVP response toward the baseline level after the end of fluid infusion was fastest under halothane anesthesia, while the recovery time of CVP was two times longer under TSA and MTX. Based on the relationship between changes in CVP and BV, we quantified effective vascular compliance and stress relaxation using mathematical analysis. The effective vascular compliance increased to 13.3 +/- 3.2 ml.mmHg-1.kg-1 under TSA as compared to 5.6 +/- 0.3 ml.mmHg-1.kg-1 under halothane anesthesia, and it decreased to 2.6 +/- 0.2 ml.mmHg-1.kg-1 with MTX. Stress relaxation was determined as the time constant in the unit response of CVP. The time constant for stress relaxation was 39 +/- 7 min under halothane, 74 +/- 12 min with TSA, and 92 +/- 25 min with MTX. These results suggest that the autonomic nervous system modifies cardiac preload by changing effective vascular compliance and stress relaxation.

Anesthesia, Spinal↗
PubMed1991

Strategy for the diagnosis of small acoustic neuromas.

Twenty small (extra-meatal size less than 15 mm) acoustic neuromas have been diagnosed since high-resolution (HR) magnetic resonance imaging (MRI) became available in our clinic. Among these tumors, 18 had sensorineural hearing loss and 16 enlarged internal auditory meatus in X-ray photo, but only 8 tumors out of 18 tested showed diminished caloric response. Auditory brainstem responses (ABR) has been believed as the most reliable test for the diagnosis of acoustic neuroma despite several reports of false-negatives. In our series, 4 tumors out of 18 tested had normal ABR. The false-negative rate was 22%, which is much higher than expected. In CT, only 11 tumors were recognized. Although the total number is not large, present results clearly suggest the limits of these examinations. At present, HR-MRI is the most reliable diagnostic method for acoustic neuromas with no false-negative reported; ordinary MRI may have false-negatives. For the effective use of MRI, the results of audiometry, X-ray photo, ABR and other examinations must be evaluated properly.

Audiometry↗