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Biomedical subjects

M Shiba

Publications and source records attributed to M Shiba.

At least 37 records · Page 2Linked to original sources

Histological estimation of the efficacy of endoscopic laser coagulation therapy for diffuse antral vascular ectasia.

We present the case of a 72-year-old woman with successful control of repeated episodes of bleeding from diffuse antral vascular ectasia (DAVE) by laser coagulation therapy. In addition to DAVE, the patient also suffered from severe iron deficiency anaemia (due to recurrent bleeding), liver cirrhosis, and huge tumours of hepatocellular carcinoma (HCC). She was referred from another hospital after failure to stop her bleeding episodes. Endoscopic examination revealed diffuse speckled telangiectasia over most of the stomach (from antrum to the upper portion of the body) and large numbers of blood clots. The patient had received repeated blood transfusions, haemostatic drugs, and H2 receptor antagonists at the other hospital, without improvement of the repeated bleeding. She underwent three sessions of endoscopic laser coagulation therapy for the lesions at our hospital after the final diagnosis of DAVE had been made based on the characteristic histological findings of biopsied specimens. This treatment improved her general condition and stopped the bleeding from the gastrointestinal tract even without fasting. Unfortunately, however, her liver function gradually worsened due to HCC and previous massive bleeding, and she finally died of liver failure three months after the last laser session. Autopsied specimens obtained from the patient's stomach revealed that macroscopic diffuse speckled telangiectasia and microscopic typical vasodilatation in mucosal and submucosal layers of gastric tissue had disappeared in the treated areas but not all portions of the DAVE lesion. These histological findings for the treated areas, in addition to the clinical improvement of bleeding, suggest that endoscopic laser coagulation therapy may be useful and one of the first choices in treatment for DAVE.

Aged↗

Gamma-ray-irradiated red blood cells stored in mannitol-adenine-phosphate medium: rheological evaluation and susceptibility to oxidative stress.

BACKGROUND AND OBJECTIVES: To evaluate the rheological properties and the oxidative susceptibility of gamma-ray-irradiated red blood cells (RBCs). MATERIALS AND METHODS: RBCs in mannitol-adenine-phosphate (MAP) medium were irradiated with 35 Gy and stored at 4 degrees C for 4 weeks. The deformability of the RBCs was examined under shear flow in relation to the morphological and biochemical changes. The RBCs were further exposed to 1 mM FeSO(4) and 5 mM ascorbate to examine the oxidative susceptibility. RESULTS: The RBC deformability was decreased during storage, and the impairment was further enhanced by the irradiation, which promoted cell shrinkage and intracellular hemoglobin condensation accompanying potassium loss. Lipid peroxidation and protein aggregation of the RBC membrane as well as echinocytosis were not enhanced by the irradiation. The exposure to free iron did not stimulate the oxidation of the irradiated RBC membrane. CONCLUSION: The decreased deformability of gamma-ray-irradiated RBCs in MAP medium was mainly induced by dehydration due to potassium loss, and the membrane lipids and proteins were stably preserved against oxidative stress.

Adenine↗

Helicobacter pylori: criminal or innocent bystander?

Most patients with peptic ulcer disease are infected with Helicobacter pylori. However, the infection may not be always causative for the disease. The prevalence of H. pylori infection is about 50% in general. Therefore, half of the patients with peptic ulcer could be infected with this microorganism just by chance. In such cases, H. pylori may do nothing for the ulcer, although it causes chronic active gastritis. This could be the reason for the existence of both H. pylori-positive nonrecurring ulcers and ulcers that recur even after cure of H. pylori infection. H. pylori-positive non-recurring ulcers should be included in non-H. pylori ulcer disease in addition to H. pylori-negative ulcers. NSAIDs are the major cause of H. pylori-negative ulcers, especially H. pylori-negative gastric ulcers. However, more than 10% of ulcers recurred even after cure of H. pylori infection in nonusers of NSAIDs in a 7-year follow-up study. In the same study, 46% of ulcers did not recur in patients in whom eradication of H. pylori failed. There are few (<5%) H. pylori-negative ulcers; about 10% of ulcers recur after cure of H. pylori infection, and about 40% of H. pylori-positive ulcers do not recur. These are all non-H. pylori ulcers, and they represent 30% of all ulcers, which is the general prevalence rate for nonulcer subjects. Therefore, H. pylori may be an innocent bystander in approximately one third of all ulcer patients.

Anti-Inflammatory Agents, Non-Steroidal↗

Decreased deformability of the X-ray-irradiated red blood cells stored in mannitol-adenine-phosphate medium.

X-ray irradiation of blood is an effective way to prevent transfusion-associated graft-versus-host disease. Red blood cells (RBCs) from normal donors suspended in mannitol-adenine-phosphate (MAP) medium were irradiated with X-ray of 15 and 35 Gy in minimum dose. The change of deformability of the RBCs during storage at 4 degrees C for 4 weeks was examined under shear stress of 13-130 dyn/cm2 using a rheoscope, in relation to the hematological and biochemical properties. (1) The deformability of RBCs was decreased during the storage, and it was further decreased by the irradiation. In addition, the number of undeformable RBCs against a given shear stress increased after the irradiation. (2) The cell volume gradually decreased, while the intracellular hemoglobin concentration increased. These changes were accelerated by the irradiation. The echinocytic transformation during the storage was not accelerated by the irradiation. (3) The content of aggregated proteins reducible with beta-mercaptoethanol in RBC membrane increased during the storage, but was not increased by the irradiation. Membrane lipid peroxidation was not increased during the storage and by the irradiation. (4) Leakage of potassium ions from RBCs during the storage was accelerated by the irradiation. In conclusion, shear-induced deformation of RBCs stored in MAP medium was impaired by X-ray irradiation, mainly due to dehydration caused by excess leakage of potassium ions from RBCs.

Adenine↗

Effects of Sho-saiko-to, a Japanese herbal medicine, on hepatic fibrosis in rats.

It has been shown that lipid peroxidation is associated with hepatic fibrosis and stellate cell activation. Sho-saiko-to (TJ-9) is an herbal medicine, which is commonly used to treat chronic hepatitis in Japan, although the mechanism by which TJ-9 protects against hepatic fibrosis is not known. As a result, we assayed the preventive and therapeutic effects of TJ-9 on experimental hepatic fibrosis, induced in rats by dimethylnitrosamine (DMN) or pig serum (PS), and on rat stellate cells and hepatocytes in primary culture, and assessed the antioxidative activities and the active components of TJ-9. Male Wistar rats were given a single intraperitoneal injection of 40 mg/kg DMN or 0.5 mL PS twice weekly for 10 weeks. In each model, rats were fed a basal diet throughout, or the same diet, which also contained 1.5% TJ-9, for 2 weeks before treatment or for the last 2 weeks of treatment. TJ-9 suppressed the induction of hepatic fibrosis, increased hepatic retinoids, and reduced the hepatic levels of collagen and malondialdehyde (MDA), a production of lipid peroxidation. Immunohistochemical examination showed that TJ-9 reduced the deposition of type I collagen and the number of alpha-smooth muscle actin (alpha-SMA) positive-stellate cells in the liver and inhibited, not only lipid peroxidation in cultured rat hepatocytes that were undergoing oxidative stress, but also the production of type I collagen, alpha-SMA expression, cell proliferation, and oxidative burst in cultured rat stellate cells. In addition, TJ-9 inhibited Fe2+/adenosine 5'-diphosphate-induced lipid peroxidation in rat liver mitochondria in a dose-dependent manner and showed radical scavenging activity. Among the active components of TJ-9, baicalin and baicalein were found to be mainly responsible for the antioxidative activity. These findings suggest that Sho-saiko-to (TJ-9) functions as a potent antifibrosuppressant by inhibition of lipid peroxidation in hepatocytes and stellate cells in vivo.

Animals↗

Suppressive effects of estradiol on dimethylnitrosamine-induced fibrosis of the liver in rats.

As a model for the analysis of the fibrosuppressive role of estradiol, hepatic fibrosis was induced in male and female rats by the administration of a single dose of dimethylnitrosamine (DMN). The fibrotic response of the male liver after DMN treatment was significantly stronger than that of the female liver. In the male DMN model, estradiol reduced hepatic mRNA for type I and III procollagens and the tissue inhibitor of metalloproteinase-1 (TIMP-1), as well as deposition of type I and III collagen protein total hepatic collagen and malondialdehyde (MDA), a product of lipid peroxidation. Concomitant administration of a neutralizing antibody against rat estradiol enhanced fibrogenesis, as judged by the same parameters. Ovariectomy in the female model had a fibrogenic effect, inducing the hepatic expression of both types of procollagen and TIMP-1; in addition, the number of alpha-smooth muscle actin (alpha-SMA)-positive cells in the liver increased; estradiol replacement was fibrosuppressive in the castrated-female model. In rat hepatic stellate cells incubated in primary culture with estradiol, cell number, type I collagen production, and alpha-SMA expression were all reduced. These findings suggest that estradiol suppressed the induction of hepatic fibrosis, and may in part underlie the more rapid progression in males of hepatic fibrosis and its complications.

Animals↗

Pulmonary blastoma: report of a case.

A 30-year-old woman was admitted to our hospital for investigation of an abnormal shadow in the right pulmonary hilus on a chest X-ray film. A percutaneous needle biopsy was performed, which revealed pulmonary blastoma. A right upper lobectomy was performed and the pathological stage was confirmed to be IIIa (T3N0M0). An analysis of preoperative cytological specimens showed that epithelial tumor cells with thin cytoplasm were either tubular or papillary, while some mesenchymal tumor cells with elliptic and spindle-shaped nuclei were also found in the necrotic background. Thus, pulmonary blastoma should be considered when a two-cell pattern consisting of both epithelial and mesenchymal components is observed. DNA analysis was performed on previously identified areas of the epithelial or sarcomatous components, using a microdissection method. An analysis of the p53 gene by the single-strand conformation polymorphysm method showed an abnormal band with shifted mobility of exon 8 in only the sarcomatous component.

Adult↗

Prognostic factors in surgical treatment of solitary brain metastasis after resection of non-small-cell lung cancer.

Patients with brain metastasis after resection of non-small-cell lung cancer usually have poor prognosis. A few such patients, however, survive for long periods after surgical resection of brain metastases. To evaluate the prognostic factors in resection of solitary brain metastasis from non-small-cell lung cancer, we reviewed 24 cases undergoing resection of solitary brain metastasis after resection of the primary site from 1977 to 1993. The patient population consisted of 20 men and four women ranging in age from 40 to 75 years old (average, 57.8 years old). None of the patients had systemic metastasis except in the brain at the time of brain surgery. The overall survival rates were 12.5% at 3 years and 8.3% at 5 years after brain surgery. The longest survival periods were 11.5 years after brain surgery and 15.4 years after lung surgery. The interval between lung and brain surgery (< or =360 days vs. >360 days), differentiation of primary cancer (poor vs. moderate), size of primary site (< or =5.0 cm vs. >5.0 cm), and operation of primary site (lobectomy vs. pneumonectomy) significantly affected survival as shown by univariate analysis (P<0.05). Other clinical factors (age, gender, histology, T- and N-status, 'resectability with curative intent' of the primary site, location of the brain metastasis and postoperative radiation therapy) did not affect survival. Multivariate analysis using Cox's proportional hazards model indicated that an interval of more than 360 days between the two surgical procedures (hazard ratio = 0.2351, P = 0.0136) and lobectomy (hazard ratio = 0.5274, P = 0.0416) were independent prognostic factors. In conclusion, patients with solitary brain metastasis from non-small-cell lung cancer without other organ metastasis, in whom relapse in the brain occurred more than 1 year after resection of the primary site and in whom lobectomy was performed, should be treated surgically to maximize the chance of prolonged survival.

Adenocarcinoma↗

Endoscopic resection of two granular cell tumours of the oesophagus.

Granular cell tumour of the oesophagus is rare and usually single. It is diagnosed by endoscopic appearance, results of endosonography, and histological examination of biopsy specimens. Although histological examination is required for diagnosis, it is difficult occasionally to obtain tumour samples by forceps because granular cell tumour is usually located in the submucosal layer. We report the case of a Japanese man with two granular cell tumours of the oesophagus. One lesion was diagnosed as a granular cell tumour by histological examination of a biopsy specimen, but the other was not. Endoscopic resection was performed to obtain the diagnosis and treat the lesions since some granular cell tumours are potentially malignant. Both tumours were completely resected endoscopically, and the diagnosis of granular cell tumour could be established by histological examination of resected tissue. Endoscopic resection is thus useful in the diagnosis and treatment of granular cell tumour of the oesophagus.

Adenocarcinoma↗

Inhibitory effect of oestradiol on activation of rat hepatic stellate cells in vivo and in vitro.

BACKGROUND: Hepatic stellate cells play a key role in the pathogenesis of hepatic fibrosis. AIMS: To examine the inhibitory effect of oestradiol on stellate cell activation. METHODS: In vivo, hepatic fibrosis was induced in rats by dimethylnitrosamine or pig serum. In vitro, rat stellate cells were activated by contact with plastic dishes resulting in their transformation into myofibroblast-like cells. RESULTS: In the dimethylnitrosamine and pig serum models, treatment with oestradiol at gestation related doses resulted in a dose dependent suppression of hepatic fibrosis with restored content of hepatic retinyl palmitate, reduced collagen content, lower areas of stellate cells which express alpha smooth muscle actin (alpha-SMA) and desmin, and lower procollagen type I and III mRNA levels in the liver. In cultured stellate cells, oestradiol inhibited type I collagen production, alpha-SMA expression, and cell proliferation. These findings suggest that oestradiol is a potent inhibitor of stellate cell transformation. CONCLUSION: The antifibrogenic role of oestradiol in the liver may contribute to the sex associated differences in the progression from hepatic fibrosis to cirrhosis

Animals↗

Prevalence of dementia in the rural village of Hanazono-mura, Japan.

We studied the prevalence of dementing disorders in a rural municipality of Japan (Hanazono-mura), using a door-to-door two-phase design. In phase 1, the Hasegawa's Dementia Scale-Revised was applied as a screening test to all subjects aged 65 years and older (n = 201). Among subjects screened positive, 17 were diagnosed with dementia in phase 2. The prevalence (cases/100 aged 65 years and older) was 8.5 for all types of dementia, 3.5 for Alzheimer's disease, 3.0 for vascular dementia, and 2.0 for other dementia (including mixed dementia). The prevalence of dementia was slightly but consistently higher in men than women at all ages. The overall prevalence was higher in women for Alzheimer's disease and in men for vascular dementia.

Aged↗

Elevated levels of circulating plasma matrix metalloproteinase 9 in non-small cell lung cancer patients.

Elevated expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 have been implicated as playing important roles in tumor invasion and metastasis in various tissues. We investigated the relationship between circulating plasma MMP-9, its expression in tumor samples, and other clinical features in patients with non-small cell lung cancer (NSCLC). A series of 73 patients (45 men and 28 women) who underwent surgery for NSCLC was used in this study. Preoperative plasma concentrations of MMP-9 were examined using a one-step sandwich enzyme immunoassay. Expression levels of MMP-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 were measured in 24 tumor samples by immunohistochemistry. The plasma concentration of MMP-9 in NSCLC patients (71.0 +/- 60.2 ng/ml) was significantly elevated compared to that of healthy volunteers (P < 0.0001). MMP-9 concentrations were elevated in 33 of 73 cases (45.2%), compared with a cutoff value of the mean +/- 2 SD in healthy volunteers. There were statistically significant differences in MMP-9 concentration in adenocarcinoma versus squamous cell carcinoma (P = 0.014) and adenocarcinoma versus large cell carcinoma (P = 0.014). Five of 24 patients (20.8%) had positive immunohistochemical MMP staining of the tumor cell cytoplasm, and two cases had positive staining in the surrounding stromal cells. Plasma MMP-9 concentrations were elevated in 45.2% of NSCLC patients; however, this elevation did not seem to correlate with MMP-9 production by cancer and stromal cells. We concluded that the MMP-9 ELISA could be a beneficial adjunct for assessing the tumor burden of NSCLC, especially for types of squamous cell carcinoma and large cell carcinoma.

Aged↗

Allelic loss of chromosome 13q14.3 in human oral cancer: correlation with lymph node metastasis.

To evaluate the role of chromosome 13 deletions in oral squamous cell carcinoma (SCC) progression and to define the precise localization of putative tumor suppressor genes, we studied tumors from 34 unrelated patients with oral SCC by the polymerase chain reaction (PCR)-loss of heterozygosity (LOH) assay, using 18 different polymorphic loci. Chromosome 13q allelic losses (LOH) were observed in 67.6% at 1 or more loci. These results enabled the identification of a putative minimal region of deletion mapped at 13q14.3. The commonly deleted region is located close, but telomeric to the RB1 locus. We also examined the same samples for inactivation of the RB1 gene by immunohistochemical analysis of paraffin-embedded samples, but no significant variation in RB protein expression was detected. In addition, we also performed PCR-single-strand conformational polymorphism (SSCP) analysis to detect any mutation of the RB1 gene using 52 primer pairs, which covers all exons of this gene. We found no mutations of the RB1 gene in our samples. Interestingly, we found significant correlation between LOH of 13q14.3 and lymph node metastasis. Our results indicate that LOH of 13q is a common event in oncogenesis and/or progression of oral SCC, and also suggest the existence of a new suppressor gene near D13S273-D13S176 loci which may play a role in these events.

Carcinoma, Squamous Cell↗

Non-synchronous double adenoma of the parathyroid gland.

A 46-year-old female underwent an excision of a parathyroid adenoma diagnosed as recurrent primary hyperparathyroidism 24 years after the initial excision of a parathyroid adenoma. We report a case of non-synchronous double adenomas of the parathyroid glands documented histopathologically.

Adenoma↗

Repetitive ventricular responses induced by radiofrequency ablation for idiopathic ventricular tachycardia originating from the outflow tract of the right ventricle.

In 23 consecutive patients, radiofrequency (RF) ablation was used as treatment for idiopathic ventricular tachycardia (VT) originating from the outflow tract of the right ventricle. In this study, we focused on the repetitive ventricular response (> 5 consecutive QRS beats during RF application). The incidence and clinical implications of the repetitive ventricular response were examined through the results of endocardial mapping and RF ablation. VT origin was mapped as the earliest activation site during VT, and it was determined within 0.5 x 0.5 cm (narrow site) in 13 patients and wider than 0.5 x 0.5 cm (wide origin) in the other 10 patients. The repetitive ventricular response was induced during application of RF current in 14 of 23 patients (61%), and it was more frequently observed in VT from a wide origin (100%) than in the VT from a narrow site (31%). The QRS morphology of the repetitive ventricular response was identical to that of clinical VT. As RF application was continued and/or repeated, the RR interval of the repetitive ventricular response was gradually prolonged, the number of consecutive QRS complexes was decreased, and clinical VT was finally eliminated. The overall success rate of RF ablation was 96% (22/23 patients), and no complications were observed. In conclusion, a repetitive ventricular response was frequently observed in idiopathic right VT. The changing pattern of repetitive ventricular response, slowly and/or disappearing was consistent with successful RF ablation.

Adult↗

Frequency dependent shortening of conduction time through the reentrant pathway during transient entrainment of ventricular tachycardia.

In a patient with nonischemic ventricular tachycardia (VT), VT was entrained and the conduction time from the pacing site to the entrained local electrogram showed a rate dependent shortening and its degree affected by the pacing site. The QRS complex, which was entrained by the last pacing stimulus, was constant and identical to that of VT and no rate dependent facilitated conduction was observed when the heart was paced at similar paced cycle lengths during sinus rhythm. As the mechanism of the shortening of the conduction time through the reentrant circuit, a shift of the entrance seems most likely.

Aged↗

Expression of type I and type III collagens during the course of dimethylnitrosamine-induced hepatic fibrosis in rats.

AIMS/BACKGROUND: We wished to clarify the mechanisms that account for the increase in hepatic collagen accumulation during hepatic fibrosis. METHODS: The gene expression of type I and type III procollagens and matrix metalloproteinase-1 (MMP-1) was measured by Northern blot analysis; immunolocalization of both types of collagen was estimated by indirect immunohistochemical assay; and the hepatic content of collagen and malondialdehyde (MDA), a product of lipid peroxidation, were assayed in hepatic fibrosis induced in rats with a single dose of dimethylnitrosamine (DMN). RESULTS: During the experimental period, more type I procollagen mRNA was found than type III procollagen mRNA. The immunoreactive intensity of type I collagen was greater in necrotic areas near central veins 3 days after DMN treatment than it was on day 9, whereas the type III collagen immunodeposition for the latter period of the hepatic fibrosis was stronger than it was on day 3. As compared with controls, hepatic collagen content increased significantly after 3 days and continued, increasing gradually, as did type I and III procollagen mRNA levels. On day 14, fibrosis was greatest and both types of procollagen gene expression were at their highest, and type I and III procollagen mRNA levels and hepatic collagen content increased as the dosage of DMN was raised. MMP-1 mRNA levels increased early in hepatic fibrogenesis, and increased on day 14 when DMN dosages were low. Hepatic MDA levels increased rapidly for 3 days after DMN treatment, remaining significantly higher than control values and showing a significant increase even in response to low DMN doses on day 14. CONCLUSIONS: Our results suggested that fibrotic liver collagen content may make its first notable increase due in part to the balance between type I collagen and MMP-1 expression rates. Also, lipid peroxidation may be important in the mechanism of hepatofibrogenesis.

Animals↗