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Biomedical subjects

J Yoshida

Publications and source records attributed to J Yoshida.

At least 271 records · Page 15Linked to original sources
PubMed1995

[An experimental study on the protective effect of hepatocyte growth factor (HGF) for the primary cultured hepatocytes obtained from iron-loaded rats].

Pathological iron deposition in liver is often found in various liver diseases. The deposited iron is thought to be one of the most important factor of liver cell injury, not only in hemochromotosis but also in cirrhosis following hepatitis virus B or C infection. To investigate the influence of the deposited iron on damage and regeneration of hepatocyte, primary cultured hepatocytes obtained from carbonyl iron-loaded rats were treated with carbon tetrachloride (CCl4) in the presence or absence of hepatocyte growth factor (HGF). Although the section of liver from carbonyl iron-loaded rats showed no necrosis and fibrosis, iron-loaded hepatocytes contained about twofold more iron than control. The damage of iron-loaded hepatocytes induced by CCl4 was more serious than that of control, and HGF decreased this injury only in iron-loaded hepatocytes but not in control. There is no difference in DNA synthesis stimulated by HGF between iron-loaded hepatocytes and control. These findings suggest that the pathological iron deposition induces the fragility of hepatocyte and that cytoprotective effect of HGF is induced by this pathological iron.

Animals↗
PubMed1995

Pulmonary metastasis of renal cell carcinoma resected sixteen years after nephrectomy.

A 50-year-old man underwent a left nephrectomy for renal cell carcinoma of the clear cell type in February, 1978. He was examined using computed tomography in September, 1993, and was found to have a small coin lesion in his right lung. A fine needle aspiration biopsy failed to disclose any tumor cells. He underwent a video-assisted thoracoscopic biopsy of the right lung in February, 1994, 16 years after his nephrectomy. The resected specimen contained a coin lesion measuring approximately 1 cm in diameter, and the lesion was microscopically diagnosed as a renal cell carcinoma of the clear cell type metastatic to the lung. The patient is doing well with no signs of re-recurrence six months after the resection of the metastatic lesion. To our knowledge, the time interval between his nephrectomy and resection of the metastatic lesion is the longest ever reported in Japan.

Biopsy↗
PubMed1995

Relationship between Helicobacter pylori infection, atrophic gastritis and gastric carcinoma in a Japanese population.

AIM: To evaluate the possible relationship between Helicobacter pylori infection and gastric carcinoma, and its precursor lesion, intestinal metaplasia, in a Japanese population. SUBJECTS AND METHODS: H. pylori infection was identified by the presence of anti-H. pylori immunoglobulin (Ig)G. The frequency of H. pylori infection was compared in 109 patients with gastric carcinoma, the same number of patients with atrophic gastritis and asymptomatic controls matched for age, sex and place of birth. To study the relation between H. pylori and intestinal metaplasia, sera and gastric antral and corpus mucosal biopsies were obtained from 58 asymptomatic controls, 92 patients with chronic gastritis and 80 patients with peptic ulcer. RESULTS: The presence of IgG antibody to H. pylori was significantly more frequent in those with gastric carcinoma than in asymptomatic controls (87.2 versus 74.3%; odds ratio 2.4; 95% confidence interval 1.2-4.8). The positive rates of H. pylori IgG antibody were 80.7% in patients with atrophic gastritis. Mean serum gastrin and pepsinogen II levels in H. pylori-positive patients were higher than those in H. pylori-negative patients. Serum gastrin and pepsinogen I levels were significantly higher in controls than gastric carcinoma patients (P < 0.01 and P < 0.05, respectively). Serum pepsinogen I:II ratios were significantly lower in controls than in gastric carcinoma patients (P < 0.01). Intestinal metaplasia was strongly associated with H. pylori infection, and was only found in patients with IgG antibodies to H. pylori. CONCLUSIONS: These results suggest that H. pylori infection is associated with the development of gastric cancer by providing a suitable environment for carcinogenesis of the gastric mucosa, such as gastric atrophy and intestinal metaplasia.

Enzyme-Linked Immunosorbent Assay↗
PubMed1995

[The effectiveness of interferon-beta against glioma cells and its augmentation of growth inhibitory effect by transfection of its gene].

The mortality and morbidity of patients with malignant glioma is not satisfactory, although the survival time is prolonged by several adjuvant therapies. In order to increase the survival time, various studies have been undertaken. In the present article, at first we discuss the effectiveness of the single and/or combined therapy of interferon-beta. Although a synergistic effects with radiation is noted in nitrosoureas and interferon-beta, and it is the most effective treatment for malignant glioma at present, it is still necessary to continue to search for an effective strategy to prolong survival of the patients. To improve the interferon-beta cytokine therapy, we have studied liposome mediated transfection of cytokine genes to control glioma cells. For this purpose, human beta-interferon gene entrapped in liposome was transfected into glioma cells and the growth inhibitory effect was observed. Successful secretion of interferon-beta and remarkable suppression effect to the glioma cells was demonstrated and this effect was enhanced by conjugating with monoclonal antibody G-22 on the surface of liposome. These results suggest that interferon-beta gene transfection by the use of liposome coupled with monoclonal antibody might become a useful technique for gene therapy of malignant glioma.

Antibodies, Monoclonal↗
PubMed1995

Radioimaging of human glioma by indium-111 labeled G-22 anti-glioma monoclonal antibody.

We previously have reported that indium-111 labeled anti-glioma monoclonal antibody G-22 (111In-G-22) exhibits diagnostic potential against human glioma xenografts in athymic mice. Herein, we report the selective tumor localization of 111In-G-22 in patients with glioma. Five patients were administered an average of 2.2 mCi of 111In-G-22 whole IgG intravenously. No immediate or delayed side effects were attributable to 111In-G-22 injection. Serial gamma scintigraphy and single photon emission computed tomography (SPECT) were performed, and the distribution in the brain and intratumoral accumulation of 111In-G-22 were evaluated. CT and/or magnetic resonance (MR) images were performed simultaneously and these images were compared. In the case of malignant glioma, tumor-imaging was successfully obtained beginning at 6 h following injection with a maximum uptake tumor/brain ratio at 48 h. The distribution of 111In was selective. It predominantly accumulated in the biologically active areas of the tumor. Furthermore, the tracer uptake appeared to correlate with the histologic tumor grade. This confirms the G-22 monoclonal antibody specifically binds to biologically active and malignant glioma tissue, and tumor-imaging using 111In-G-22 may give support to the diagnosis of malignant glioma.

Adolescent↗
PubMed1995

[Antitumor effect of intra-arterial tumor necrosis factor-alpha in rats with transplanted intracerebral glioma and its evaluation by MRI].

Recombinant human TNF-alpha was administrated intra-arterially to rats with transplanted intracerebral glioma. 1 x 10(6) of T9 rat glioma cells were transplanted into Fisher 344 rat brain stereotaxically and 1000 units of TNF-alpha was administrated at a rate of 100 microl/min. via an internal carotid artery 1 or 3 weeks after the transplantation. The effects of TNF-alpha were evaluated by MRI and histopathological examinations. Neurological symptoms, i.e. hemiparesis, appeared after 9.0 +/- 0.63 days and all rats died of tumor overloading 14.5 +/- 0.84 days after the transplantation. Single injection of TNF-alpha on 7th day after the transplantation induced regression of the tumor size in one of six rats. The tumors were detected 3 days after transplantation by MRI and they were revealed as low/iso intensity mass in T1WI, iso/high intensity in T2WI, and were enhanced by Gd-DTPA heterogeneously. On 7/14 days after the transplantation, the tumor grew approximately 7/10 mm in diameter. The single 1000 units of TNF-alpha were administrated via an internal carotid artery. 3 days after the administration of TNF-alpha, regression of the tumor size was seen in one of six rats and decrease of peritumoral edema was seen in three. These effects of TNF-alpha were, however, transient and they were not demonstrated on day 7. Single injection of TNF-alpha was not effective for large tumors more than 10 mm in diameter seen 14 days after the transplantation. These data suggest that intra-arterial TNF-alpha should be administrated at an early stage of the tumor growth and several injections are needed to cause regression in the size of the gliomas.

Animals↗
PubMed1994

Growth inhibition of subcutaneously transplanted human glioma by transfection-induced tumor necrosis factor-alpha and augmentation of the effect by gamma-interferon.

Using subcutaneous solid tumors produced by U251-MG human glioma cells, we studied the in vivo transfection of the cells with the tumor necrosis factor-alpha (TNF-alpha) gene delivered by means of liposomes. When the tumor had become 7 mm in diameter, liposomes with entrapped TNF-alpha gene were injected into the center of the subcutaneous tumor. We found that mRNA of transfection-induced TNF-alpha, which was expressed in the tumor tissue, was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) method and its protein was demonstrated by enzyme-linked immunoassay. Growth of the tumor was inhibited when the injection was carried out five times at every other day. The growth-inhibitory effect by transfection-induced TNF-alpha was much remarkable as compared with exogenous TNF-alpha and the effect was enhanced by the intraperitoneal injection of gamma-interferon (IFN-gamma) 12 h prior to intratumoral injection of the liposomes.

Animals↗
PubMed1994

Efficient transfection of human interferon-beta gene to human glioma cells by means of cationic multilamellar liposomes coupled with a monoclonal antibody [corrected].

We have been devoting our efforts to develop the useful liposomes that have high potentials of gene transfer and we aim human gene therapy for malignant glioma with cytokine genes. In our previous study, we prepared our original reverse-phase evaporation vesicles (REV) by an improved procedure of reverse-phase evaporation method. However, this procedure was very complicate. In this paper, a simple procedure for the preparation of cationic multilamellar vesicles (MLV) was introduced, and efficient expression and growth-inhibitory effect of MLV with entrapped human interferon-beta gene to glioma cells was comparable to that obtained with REV. Considering the present experiments, MLV seem to be more preferable for clinical application.

Brain Neoplasms↗
PubMed1994

Anti-(glioma surface antigen) monoclonal antibody G-22 recognizes overexpressed CD44 in glioma cells.

We raised an anti-glioma monoclonal antibody, named G-22, that specifically recognizes a human glioma-associated surface antigen. Proven to be useful for target imaging of malignant gliomas after radioisotope labeling and cerebrospinal fluid diagnosis by enzyme-linked immunospecific assay, G-22 was found to immunoprecipitate an 85-kDa glycoprotein of the human glioma U-251MG cell. We purified this antigen by G-22-coupled cyanogenbromide-activated Sepharose affinity chromatography, and sequence analysis demonstrated that the 54 amino acid residues were identical to positions 55-108 of human CD44. The results show that the smallest spliced form (85 kDa) of CD44 is strongly expressed in glioma cells.

Amino Acid Sequence↗
PubMed1994

Squamous cell carcinoma of the splenic flexure of the colon: report of a case.

A 51-year-old Japanese man underwent resection of a tumor in the splenic flexure of the colon, which proved to be squamous cell carcinoma. At the time of presentation, the liver was found to have multiple metastases. On the 39th postoperative day, the patient died of liver failure. An autopsy demonstrated metastatic nodules on the pleura and parenchyma of both lungs, as well as in the liver, but failed to show any other primary squamous cell carcinoma. We emphasize that a meticulous search to disprove adenosquamous carcinoma is mandatory before a diagnosis of squamous cell carcinoma of the colon can be confirmed.

Carcinoma, Squamous Cell↗
PubMed1994

Long-term follow-up results of 175 patients with malignant glioma: importance of radical tumour resection and postoperative adjuvant therapy with interferon, ACNU and radiation.

We analysed long-term follow-up results of 175 patients with malignant glioma (110 glioblastoma and 65 anaplastic astrocytoma) treated under five different regimes during the past two decades. The factors of age (less than 40), histology (anaplastic astrocytoma) and type of adjuvant therapy (radiation and chemotherapy) contributed to long survival. The other important factor was the response to adjuvant therapy. Cases of gross total removal or complete response (CR) of a residual tumour to an adjuvant therapy showed a better prognosis. The three and five year survival rate was 42% and 24%, respectively. The highest CR ratio (23%) was seen in patients treated by intravenous injection of interferon and ACNU in addition to radiotherapy (IAR therapy).

Adolescent↗
PubMed1994

Small PACS for digital medical images--reliability and security in a clinical setting.

Recently we introduced a small Picture Archiving Communication System (PACS) for handling CT and MRI data. Our experience with this system has been useful in identifying potential problems in a clinical setting. Since the use of PACS raises both medical and social concerns, it cannot be instituted without addressing concerns related to the reliability and security issues. Although PACS is useful in the management of medical images, there are concerns about their reliability and security in a clinical setting. Reliability encompassed image quality, timeliness of the reports, and the PACS to the Radiological Information System (RIS) interface including the retrieval of the previously obtained images. The security of the patient's medical data is also essential.

Computer Security↗
PubMed1994

Study on the carcinogenicity of tannic acid in F344 rats.

The carcinogenicity of tannic acid, a compound that is used as a food additive, a clarifying agent and a refining agent, was examined in F344 rats of both sexes. Tannic acid was dissolved in distilled water at concentrations of 0.25 and 0.5%. The doses were selected on the basis of results from a 13-wk subchronic study. Groups of 50 male and 50 female rats were given one of these solutions ad lib. as their drinking water for up to 2 yr. The mean body weights of the treated males were essentially comparable with those of the controls, whereas treated females had lower mean body weights than the control group. A variety of tumours developed in all groups, including the control group, but all the neoplasms were histologically similar to those known to occur spontaneously in this strain of rats, and no statistically significant increase in the incidence of any tumour was found in the treated groups of either sex. Thus, it is concluded that, under the conditions of the experiment, tannic acid has neither carcinogenic potential in F344 rats nor modifying effects on spontaneous tumour development.

Administration, Oral↗
PubMed1994

Duration and extent of antianginal effects of a sustained-release formulation of nifedipine in angina.

Twenty-four patients with chronic stable exertional angina pectoris were randomized in a double-blind, placebo-controlled, crossover trial to assess the efficacy and durability of a newly developed, sustained-release formulation of nifedipine (nifedipine CC) in a single 40-mg oral dose. Symptom-limited graded treadmill exercise tests were performed just before, and at 4, 7, and 24 h after a single administration of the drug or the placebo was given. Exercise tolerance at 4, 7, and 24 h after the drug were compared with the corresponding placebo values. Data could be analysed for 19 patients. Maximal exercise time, time to the onset of angina, and time to 1 mm ST segment placebo. The average maximal exercise time was significantly increased by 72, 76, and 37 s at 4, 7, and 24 h. Rate-pressure product at rest and at peak exercise showed significant changes only at 24 h compared with placebo (both P < 0.05). The maximal increase in exercise tolerance was most marked at 7 h nifedipine CC, at which time plasma drug concentration was 99.4 +/- 14.0 ng.ml-1. Thus, in patients with chronic stable exertional angina pectoris, nifedipine CC showed a prolonged improvement in exercise tolerance up to 24 h after a single oral administration.

Angina Pectoris↗
PubMed1994

Effects of body weight on responses of serum prolactin to metoclopramide and thyrotrophin-releasing hormone in secondary amenorrhoeic women.

The present study was designed to investigate the influence of body weight on the prolactin responsiveness to metoclopramide and thyrotrophin-releasing hormone (TRH) in secondary amenorrhoeic women. The responses of serum prolactin to metoclopramide and TRH were assessed in relation to body mass index (BMI). Doses of 10 mg of metoclopramide hydrochloride and 500 micrograms of TRH were administered i.v. to 42 secondary amenorrhoeic women and six women with primary ovarian failure. The increment of serum prolactin at 30 min after the administration of metoclopramide was significantly lower (P < 0.01, respectively) in amenorrhoeic women with a BMI of > or = 30 or < 19 than in amenorrhoeic women with a BMI of 19-24. A significant correlation ration (eta = 0.63; P < 0.01) was found between the BMI and the increment of serum prolactin at 30 min after metoclopramide administration in amenorrhoeic women. The increment of serum prolactin at 15 min after TRH administration was slightly lower in amenorrhoeic women with a BMI of > or = 30 or < 19 than in amenorrhoeic women with a BMI of 19-24, but these differences were not statistically significant. These results indicate that the body weight influences the responsiveness of serum prolactin to metoclopramide in secondary amenorrhoeic women.

Adult↗
PubMed1994

Transfection-induced tumor necrosis factor-alpha increases the susceptibility of human glioma cells to lysis by lymphokine-activated killer cells: continuous expression of intercellular adhesion molecule-1 on the glioma cells.

To develop more effective adoptive immunotherapy, we transfected the human tumor necrosis factor-alpha (TNF-alpha) gene into human glioma cells (U251-SP), which were used as target cells. TNF-alpha is known to increase both the expression of intercellular adhesion molecule-1 (ICAM-1) on the surface of glioma cells and the susceptibility of glioma cells to lymphokine-activated killer (LAK) cell cytolysis. We compared the expression of ICAM-1 induced by TNF-alpha generated by the TNF-alpha gene-transfected cells with that induced by exogenously added TNF-alpha. When the TNF-alpha gene was transfected into U251-SP cells, the expression of ICAM-1 was detected on the cell surface from 3 days after the transfection and continued until at least 9 days. In contrast, it was expressed only transiently in the case of exogenously added TNF-alpha. Also, the cytolytic activity of LAK cells induced by transfection-induced TNF-alpha was significantly stronger than that induced by exogenously added TNF-alpha. The increased susceptibility was quenched by anti-ICAM-1 monoclonal antibody. These data indicated that continuous expression of ICAM-1 induced by TNF-alpha gene transfection of glioma cells resulted in higher cytolytic activity of LAK cells.

Antibodies, Monoclonal↗
PubMed1994

Tenascin in cerebrospinal fluid is a useful biomarker for the diagnosis of brain tumour.

Tenascin, an extracellular matrix glycoprotein, has been reported to be expressed predominantly on glioma tissue in the CNS, both in a cell associated and an excreted form. Recently, a highly sensitive sandwich type enzyme immunoassay for quantitative determination of tenascin was developed. In the present study, the amount of tenascin in CSF was measured. An increase of tenascin in CSF (> 100 ng/ml) was found in patients with an astrocytic tumour. The concentration was significantly higher (> 300 ng/ml) in high grade astrocytoma (anaplastic astrocytoma and glioblastoma) and a further increase (> 1000 ng/ml) was found in cases of CSF dissemination of high grade astrocytoma. On the other hand, tenascin concentrations were less than 100 ng/ml in non-astrocytic tumours and non-neoplastic neurological diseases, except meningeal dissemination of tumour cells, meningeal stimulation by infection, and subarachnoid haemorrhage. In cases of treated astrocytomas in remission, tenascin was negligible (< 100 ng/ml) in the CSF. The measurement of tenascin in CSF is useful for differential diagnosis of brain tumours and monitoring of astrocytic tumours.

Biomarkers, Tumor↗