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Biomedical subjects

J Yoshida

Publications and source records attributed to J Yoshida.

At least 361 records · Page 20Linked to original sources
PubMed1990

[Serorrhaphy prevents regeneration of vagus nerve fibers after proximal gastric vagotomy].

UNLABELLED: Spouting or regeneration of vagus fibers occurs after vagotomy. An axonal tracing method was used to see the long-term effect of serorrhaphy in the prevention of axonal regeneration after proximal gastric vagotomy (PGV) in ferrets. METHODS: A neurotracer, wheat-germ agglutinin-horseradish peroxidase (0.5 mg), was injected subserosally at the corpus of the anterior stomach (1) without PGV (n = 4), (2) immediately after PGV (n = 2), (3) one year after PGV with serorrhaphy (n = 3), and (4) one year after PGV without serorrhaphy (n = 3). The ferrets were killed by perfusion-fixation. The brainstem was processed histochemically. Numbers of labeled cells in the dorsal motor nucleus of the vagus were statistically analyzed using square-root transformation. RESULTS: Numbers of labeled cells were 348 for (1), 13 for (2), 2 for (3), and 43 for (4). Multiple comparisons revealed significant differences in (1) vs. (2), (3), (4) and (3) vs. (4). DISCUSSION: The number of preganglionic efferent vagus cells decreased acutely after PGV, which persisted one year. Regenerated vagus axons were less in the chronic group with serorrhaphy than in the group without one. Thus time factor did not influence the regeneration, but serorrhaphy was important in preventing vagal regeneration. CONCLUSION: Serorrhaphy during PGV prevents the regeneration of preganglionic efferent vagus fibers.

Animals↗
PubMed1989

Endoscopic sclerosis of the cardia affects gastroesophageal reflux.

Gastroesophageal reflux disease remains a disorder of unknown etiology associated with abnormal function of the lower esophageal sphincter (LES) and other physiological co-factors of the pathologic reflux. Effective operations for reflux are designed to reinforce the anti-reflux barrier and alter the tendency towards abnormal reflux. We have postulated that the most important component of these procedures is the prevention of distraction of the lowermost components of the LES at the onset of a potential reflux episode. Distraction of the LES causes shortening of the effective sphincter mechanism and can initiate experimental reflux events. In this study we used endoscopic sclerosis of the submucosal space at the cardia as a means of reducing distraction of the cardia in the hope that this would reduce abnormal reflux events. Canine gastroesophageal reflux was induced by intravenous atropine and monitored by continuous esophageal pH monitoring. Sclerosis of the cardia prevented gastroesophageal reflux, without measurable effect on the LES pressure or length. Endoscopic sclerosis of the cardia may be a useful technique in the control of human gastroesophageal reflux.

Animals↗
PubMed1989

Serum 2'-5'oligoadenylate synthetase as a monitoring marker of anti-viral effect during interferon therapy for chronic type B hepatitis.

We evaluated the usefulness of serum 2'-5'oligoadenylate synthetase (2-5AS) activity assay in monitoring the anti-viral activity of chronic type B hepatitis patients during IFN therapy. The serum 2-5AS activity was rapidly increased during the above therapy and was maintained at a medium-to-high level throughout the therapy period, although the capacity for increase reflected differences among individuals. The kinetics of serum 2-5AS activity during the therapy was almost consistent with that of the PBMCs 2-5AS activity. 2-5AS activity had an inverse correlation with DNA-P; i.e. DNA-P often disappeared from serum after interferon treatment in patients with a marked response in serum 2-5AS activity. The enhancement of serum 2-5AS activity during IFN therapy seemed to correlate with an increase in anti-viral activity. The results suggest that the serum 2-5AS activity assay is a useful probe for monitoring the anti-viral activity of chronic type B hepatitis patients during interferon therapy.

2',5'-Oligoadenylate Synthetase↗
PubMed1989

The important role of left ventricular relaxation and left atrial pressure in the left ventricular filling velocity profile.

To evaluate the determinants of left ventricular filling, left ventricular filling velocity was measured by pulsed Doppler flowmetry during catheterization of the right and left sides of the heart in 37 patients with cardiac disease before and during leg elevation. During leg elevation, despite no significant change in the time constant of isovolumic relaxation (T), the peak rapid filling velocity (PVRF) increased in association with an increase in pulmonary wedge pressure (PWP), but the peak atrial filling velocity was unchanged. The PVRF correlated with the pulmonary wedge V wave - left ventricular minimum pressure difference (r = 0.68) and in multivariate regression with both T and mean PWP (R = 0.73). These results indicate that left ventricular filling is determined by both left ventricular relaxation and left atrial pressure and that an increase in left atrial pressure changes the left ventricular filling velocity profile in a manner that mimics the pattern with normal diastolic function.

Adult↗
PubMed1989

Brain stem topography of vagus nerve to the greater curvature of the stomach.

If preganglionic vagus nerve fibers enter the stomach via all of its neurovascular bundles, then proximal gastric vagotomy that divides only the bundles along the lesser curvature of the stomach neglects a potential source of innervation to the parietal cells. To determine whether or not these bundles contained preganglionic efferent vagal nerve fibers, horseradish peroxidase was applied to the central cut end of selected neurovascular bundles along the greater curvature of the stomach in rats and ferrets. Cells in the dorsal motor nucleus of the vagus (dmnX) of the rat were labeled after horseradish peroxidase applications to the right gastroepiploic, the splenic, and the short gastric bundles. The ferrets had horseradish peroxidase applied to the right gastroepiploic bundle and they also had cellular labeling of the dmnX. The labeling in cells of the dorsal motor nucleus of the vagus had a distinct topographic, rostrocaudal distribution in both species, and was maximal in the vicinity of the obex. Cells of the bilateral dmnX were labeled after horseradish peroxidase applications at all bundles. This study showed (1) that the bundles along the greater curvature of the stomach contained preganglionic efferent vagus nerve fibers, (2) that the cells of origin of these fibers were represented in the localized rostrocaudal position of the dmnX, and (3) that these fibers had their origins in the bilateral dmnX. Such nerve fibers may account for incomplete vagal denervation of the parietal cells after proximal gastric vagotomy.

Animals↗
PubMed1989

Bilateral germ cell tumors involving the basal ganglia and thalamus.

Two cases of a human chorionic gonadotropin-producing germ cell tumor originating bilaterally in the basal ganglia and thalamus are reported. The biological behavior and clinical characteristics were similar to those of unilateral germinomas involving the basal ganglia and thalamus. Common clinical features were slowly progressive unilateral pyramidal signs and bilateral and/or unilateral extrapyramidal signs which occurred either concomitantly or sequentially. Bilateral symmetrical lesions were demonstrated by computed tomography and/or magnetic resonance imaging at an early stage of illness. Serum and cerebrospinal fluid human chorionic gonadotropin levels were elevated (116 and 141 mIU/ml, respectively) but decreased and remained within normal limits after radiation therapy alone. Radiosensitivity was confirmed by repeated computed tomographic scans and tumor marker measurements. Multiple concomitant germ cell tumors is a rare, but interesting lesion, especially considering its pathogenesis and oncogenesis.

Adolescent↗
PubMed1989

[Individual differences in PCA response in the guinea pig].

Experiments were carried out to determine the cause of individual differences in the passive cutaneous anaphylaxis (PCA) response in guinea pigs. The intensity of 4-h homologous PCA produced by anti-penicillin G serum was not markedly different among eight reactive sites on the back of a specified animal, whereas considerable individual differences were observed in the PCA response, even at a specified reactive site. PCA was significantly inhibited by an antihistaminic agent, promethazine, and the tissue histamine content was significantly reduced after PCA, suggesting histamine release as a mediator. The intensity of PCA in individual animals was highly correlated with that of the histamine-induced cutaneous reaction elicited at a site adjoining the PCA but was unrelated to skin histamine content. These results suggest that the difference in susceptibility to histamine has a considerable effect on individual differences in the PCA response in guinea pigs.

Animals↗
PubMed1989

[Antigenicity of penicillin G in the guinea pig].

Antigenicity of penicillin G (PCG) was studied in guinea pigs. PCG 5 mg, 10 mg or 25 mg with Freund's complete adjuvant each on days 0, 7 and 21 was injected to a guinea pig: intramuscularly into both thighs and intracutaneously into four locations on the back. A remarkable antigenicity was induced in animals immunized with 25 mg although only low antigenicity in 5 mg and 10 mg. A maximum serum level of the antibody was observed about 2 weeks after last immunization and all of animals immunized with 25 mg died in active systemic anaphylaxis test. As mentioned above, it has been firstly demonstrated that a remarkable antigenicity of PCG can be produced by immunizing with a high dose of 25 mg in the guinea pig model in which PCG itself is used as immunogen.

Anaphylaxis↗
PubMed1989

Penicillin G-induced cutaneous anaphylaxis in the guinea pig.

Allergic cutaneous responses were induced by intradermal injection of penicillin G (PCG) and PCG-bovine serum albumin (BSA) conjugates onto the back of guinea pig actively immunized with PCG potassium (25 mg/animal) incorporated in Freund's complete adjuvant. The PCG-induced response was characterized macroscopically by erythema and edema with a maximum level at 24 hrs after elicitation and microscopically by the infiltration with basophils, macrophages and lymphocytes following with neutrophils. In addition, intensity of macrophage-infiltration shared a similar time course change with those of erythema and edema. These suggest that this response is associated to a delayed type hypersensitivity of Jones-Mote type. On the other hand, in the PCG-BSA-induced response the edema with erythema at the early phase was a noticeable observation and this response disappeared within 12 hrs, although the erythema continued by 24 hrs. Microscopically, the degranulation of mast cells and severe infiltration with neutrophils in the early phase and the infiltration of eosinophils in the late phase accompanying the infiltration with monocytes, basophils and lymphocytes were characteristic findings, which suggest that PCG-BSA response is a similar hypersensitivity to an atopic dermatitis. As mentioned above, we confirmed two types of allergic cutaneous responses in the guinea pig immunized with PCG.

Animals↗
PubMed1989

Combination chemotherapy with cisplatin and etoposide for malignant intracranial germ-cell tumors. An experimental and clinical study.

Antitumor activity against intracranial malignant teratoma by combination chemotherapy with cisplatin and etoposide was evaluated in experimental and clinical studies. A human teratoma cell line (Tera 2) was exposed in vitro to cisplatin and/or etoposide, after which cell growth inhibition and alterations of deoxyribonucleic acid (DNA) histograms were observed. The results indicated that a synergistic cytotoxic effect was achieved by use of both agents in combination. Four cases of recurrent intracranial germ-cell tumor (three malignant teratomas and one germinoma) were treated with cisplatin and etoposide. With this combination therapy, regression of the tumor was observed in all four cases (three complete and one partial), for a total response rate of 100%. During a follow-up period of 9 to 22 months, no recurrence or progression has been noted in three of these cases.

Adolescent↗
PubMed1989

Liposomes coupled with monoclonal antibodies against glioma-associated antigen for targeting chemotherapy of glioma.

Liposomes have a variety of attributes as a drug delivery system. Targeting of liposomes to specific cells has been investigated by using appropriate cytophilic ligands such as monoclonal antibodies (MAb's). In the present study, liposomes with selective cytotoxicity toward glioma cells were obtained. An MAb which reacts with a glioma-associated antigen, G-22-MAb, was coupled with liposomes by the cross-linking reagent dipalmitoyl L-alpha-phosphatidylethanolamine 3-(2-pyridyldithio)propionate. Interaction of the liposomes with glioma cells was morphologically observed by fluorescence microscopy, and uptake of liposomal contents into glioma cells was analyzed by flow cytometry using carboxyfluorescein as a marker. It was demonstrated that G-22-MAb could be coupled with liposomes without altering its specificity toward glioma cells and that coupling with the MAb led to a significant increase in the uptake of liposomal contents into glioma cells. Liposomes containing an antitumor drug, methotrexate (MTX), were prepared and their cytotoxicity was examined by a colorimetric growth assay. Upon incorporation of MTX into the MAb-coupled liposomes, the cytotoxicity toward glioma cells was increased 100-fold as compared with free MTX. These results indicate that G-22-MAb-coupled liposomes containing MTX have selective cytotoxicity toward glioma cells and could be utilized for targeting the chemotherapy of gliomas.

Antibodies, Monoclonal↗
PubMed1989

A simplified method for purification of an antitumor acidic glycoprotein from Streptococcus pyogenes (Su strain) by immunoadsorbent chromatography.

A simplified method for purification of an antitumor acidic glycoprotein (SAGP) from Streptococcus pyogenes (Su strain) by immunoaffinity chromatography is described. A cell-free crude extract prepared from the cocci was applied to the anti-SAGP IgG coupled Sepharose column, and elution was conducted with an alkaline buffer. The material eluted was confirmed to be homogeneous and identical with SAGP as demonstrated by both relative mobility on the SDS-polyacrylamide gel column and the antigenicity on the double diffusion agar plate. The cell-growth inhibitory activity of SAGP prepared by the present method was almost the same as that of SAGP purified by the previous time-consuming method. Since this simplified method provides a higher yield of SAGP, it will be useful in further studies on the biological properties of SAGP.

Antineoplastic Agents↗
PubMed1989

[Allogeneic bone marrow transplantation after the treatment of alpha-IFN and high-dose SNMC in two cases of acute myeloblastic leukemia with post-transfusional non-A, non-B hepatitis].

Two patients of acute myeloblastic leukemia (M2) with post-transfusional hepatitis (non-A, non-B) were treated with alpha-IFN and high-dose SNMC before allogeneic bone marrow transplantation. Bone marrow transplantation from HLA identical and MLR negative sibling donor was carried out when their hepatic functions were almost normalized. In the early phase after bone marrow transplantation, the hepatic function in both two cases has been stable, thus indicating that this treatment should be tried for reducing hepatic dysfunction and for safety bone marrow transplantation.

Adult↗
PubMed1989

Antitumor activity of an extract of Cordyceps sinensis (Berk.) Sacc. against murine tumor cell lines.

A warm water-extract (ECS) prepared from dried Cordyceps sinensis (Berk.) Sacc., a Chinese traditional medicine, was tested for antitumor activity in vivo and in vitro. Ehrlich ascites carcinoma cells (EAC), allogeneic to ICR mice and Meth A fibrosarcoma (Meth A), syngeneic to BALB/c mice were used as the target tumor cell lines. Mice were inoculated i.p. with 1 x 10(6) EAC or 1 x 10(5) Meth A on Day 0, and ECS or saline (control) was injected i.p. to the mice from Day 1 to Day 4. ECS-treatment increased the median survival time of the allogeneic mice inoculated with EAC to 316% of the control. Eight of the 10 ECS-treated mice survived on the 60th day (Day 60) after EAC implantation. ECS-treatment also increased the median survival time of the syngeneic mice inoculated with Meth A to 312% of the control. Half of the ECS-treated mice survived on Day 60. On the other hand, no cytotoxic effect of ECS was found on either EAC or Meth A in vitro. The antitumor effect of ECS seen in the allogeneic mice was significantly reduced when the mice received whole body X-irradiation (5 Gy) before EAC implantation. These results suggest that the antitumor effect of ECS may be mediated through its immunomodulating action.

Animals↗
PubMed1989

[Twenty-eight day repeated dose toxicity testing of diphenylamine in F344 rats].

A twenty-eight day repeated dose toxicity test of diphenylamine (DPA) was carried out in male and female F344 rats at dose levels of 1000, 333, 111 or 0 mg/kg/day. Thirty-six animals of both sexes were divided into 6 groups of equal number, 4 groups being used for the 28 days dosing study and the remainder for investigation of recovery. Inhibition of body weight gain, increase of liver, spleen and kidney weights, and anemia were observed in the highest dose groups in both sexes. The same groups demonstrated mucosal hyperplasia in the forestomach, dilatation, degeneration or necrosis of renal tubules in the corticomedullary junction, and hyperplasia in the bone marrow histopathologically. Slight increase of spleen, liver and kidney weights as well as slight degeneration of renal tubules were evident in several animals receiving the dose level of 333 mg/kg/day. Repair of histopathological lesions and anemia occurred within 14-day resting period. Based on these findings, under the present experimental conditions, the no observable effect level of DPA was 111 mg/kg/day.

Administration, Oral↗