Biomedical subjects

I Sekine

Publications and source records attributed to I Sekine.

At least 145 records · Page 8Linked to original sources

PubMed1995

Childhood thyroid diseases around Chernobyl evaluated by ultrasound examination and fine needle aspiration cytology.

Screening by ultrasound examination and fine-needle aspiration cytological biopsy (FNA) was conducted in five regions in Belarus, Ukraine, and Russia to investigate the prevalence of childhood thyroid diseases around Chernobyl. Gomel, Zhitomir, Kiev, and the western area of Bryansk are the administrative regions where severe radioactive contamination occurred. The subjects from Mogilev, where contamination was relatively low, served as controls. Among 55,054 subjects (26,406 boys and 28,648 girls), the prevalence of ultrasonographic thyroid abnormalities such as nodule, cyst, and abnormal echogenity was significantly higher in the regions with severe contamination than in Mogilev. Of the 1,396 children showing echographic thyroid abnormalities 197 were selected for FNA, and a sample was successfully obtained for diagnosis from 171 (51 boys and 120 girls) of the 197 subjects. The aspirate was insufficient for diagnosis in the remaining 26 subjects. Thyroid cancer was encountered in four children (2.3%) from the contaminated regions, two children being from Gomel. The other thyroid diseases were follicular neoplasm, 6.4%; adenomatous goiter, 18.7%; chronic thyroiditis, 31.0%; and cyst, 24.0%, suggesting that a major cause of thyroid nodularity is nonneoplastic changes, mainly chronic thyroiditis and cysts. These results will serve as an important data base for further analyses and suggest that childhood thyroid diseases, including both neoplasms and immunological disorders, are consequences of radioactive fallout.

Adenocarcinoma, Follicular↗

PubMed1995

A limited sampling model for estimating pharmacokinetics of CPT-11 and its metabolite SN-38.

The objective of this study was to develop a limited sampling model (LSM) to estimate the area under the curve (AUC) of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) and that of 7-ethyl-10-hydroxycamptothecin (SN-38) as predictive pharmacokinetic variables for leukopenia and episodes of diarrhea induced by CPT-11 administration. The model was developed with a training set consisting of pharmacokinetic studies in 36 patients who received a 90-min i.v. infusion of CPT-11 at a dose of 100 mg/m2. A multiple regression analysis of CPT-11 or SN-38 concentrations observed at each time point in the training set was used to predict the AUC of CPT-11 or SN-38. The final sampling models using only two time points were: AUCCPT-11 = 3.7891*C2.5 + 14.0479*C13.5 + 1.5463 AUCSN-38 = 0.5319*C2.5 + 19.1468*C13.5 + 72.7349 where C2.5 and C13.5 are the plasma concentration of CPT-11 (micrograms/ml) or SN-38 (ng/ml) at 2.5 and 13.5 h after the initiation of CPT-11 infusion, respectively. The models were validated prospectively on a separate test data set of 12 patients receiving the same dose of CPT-11 investigated in a previous study. Validation of the final LSM on the test data set gave values of root mean square error (RMSE) of 12.72% and 5.97% for the AUC of CPT-11 and that of SN-38, respectively. The model can be used to monitor the AUCs of both CPT-11 and SN-38 for the early prediction of toxicities and to establish a pharmacokinetically based dose modification strategy for safe administration of CPT-11.

Adult↗

PubMed1995

Parathyroid hormone-related peptide expression in endocrine tumors.

Parathyroid hormone-related peptide (PTHrP) expression is associated with the histological type in pituitary tumor, but not in thyroid carcinoma. However invasive and metastatic tumors showed intense PTHrP staining in both pituitary and thyroid tumors. Analysis of the established metastatic rat pituitary tumor cell line showed that PTHrP plays a crucial role in in vivo cell proliferation closely related to worsening of malignant transformation and neovascularization in a paracrine fashion.

Animals↗

PubMed1994

Coronary atherosclerotic smooth muscle cells overexpress human parathyroid hormone-related peptides.

Parathyroid hormone-related peptide (PTHrP) was originally characterized as a tumor product responsible for hypercalcemia of malignancy and was subsequently found to be produced in many normal tissues. PTHrP is now suggested to play a critical role in the local modulation of vascular smooth muscle function. To elucidate the involvement of PTHrP in coronary atherosclerosis, we immunohistochemically examined coronary arteries obtained from 76 patients with various grades of atherosclerosis and compared the correlation between PTHrP staining and the percent stenosis. Smooth muscle cells at sites of coronary atherosclerosis overexpressed PTHrP, while cells from normal coronary arteries did not. The in situ hybridization using PTHrP riboprobe has also proven the overexpression of PTHrPmRNA in the affected lesions following atherectomy. The intensity of PTHrP expression by smooth muscle cells was significantly correlated with the degree of coronary artery stenosis. Coronary arterial PTHrP overexpression is closely related to the severity and/or progression of coronary atherosclerosis.

Adult↗

PubMed1994

Intravascular leiomyomatosis with uterine lipoleiomyoma.

A very rare case of uterine lipoleiomyomata with intravascular leiomyoma in a 48-year-old woman is described. Located in the corpus of the uterus, the lipoleiomyomata showed proliferation of leiomyocytes intermingling with mature adipocytes. Intravascular leiomyoma was present in the broad ligament. It exhibited only spindle cells, and was reactive for HHF35 actin, without adipocytes. No continuity was detected between these tumors. Immunohistochemical studies revealed that the same portion of the intravascular leiomyoma was positive for S-100 alpha protein, NSE, factor VIII-related antigen, and HHF35 actin. These findings suggest that the leiomyomatous tumor components arise from multipotent undifferentiated mesenchymal stem cells.

Adipose Tissue↗

PubMed1994

Effect of long-term cyclic mechanical load on protein synthesis and morphological changes in cultured myocardial cells from neonatal rat.

We studied the effect of prolonged cyclic mechanical stimulation on protein synthesis and morphological changes in cultured cardiac myocytes isolated from 3-day-old neonatal rats to develop an in vitro model for cardiac hypertrophy induced by a mechanical load. Myocardial cells were cultured on deformative culture plates with M-199 culture medium in the presence or absence of fetal calf serum (FCS), and a cyclic mechanical load was applied for 2 hours up to 15 days. Mechanical stimulation for 2 hours increased the 14C-phenylalanine incorporation rate of myocardial cells, both in the absence and presence of FCS or when the myocardial cells were either beating or arrested with tetrodotoxin. The incorporation rate always increased by mechanical stimulation during 15 days of cell culture as compared to cells that sustained no mechanical stress. The cell size and protein content, which increased gradually with mechanical stimulation and reached a maximum at 10 days, were even greater in the presence of FCS. Within 10 days myocardial cells had aligned in the direction of the maximal cyclic mechanical load. In these cells electron microscopy revealed an increase in the number of myofilaments associated with the development of mitochondria as recognized in the adult myocardial cells. These results indicate that long-term cyclic mechanical loading of cultured myocardial cells may be a good in vitro model for the study of cardiac hypertrophy.

Animals↗

PubMed1994

Different susceptibility of stress-induced gastric ulcer and the autonomic nervous function in the hereditary hypertensive rats.

Susceptibility of stress-induced ulcer by restraint water immersion (RWI) was examined in Wistar Kyoto rats (WKY), spontaneously hypertensive rats (SHR) and stroke-prone spontaneously hypertensive rats (SHRSP). Ulcer formation was slight in SHR, and very slight in SHRSP. The ulcer index and blood pressure showed a significant inverse correlation (P < 0.001). Acid secretion was lowest in SHRSP, and hypergastrinemia was present in SHRSP. Gastric motility was suppressed during RWI in SHR and SHRSP. The noradrenaline content of the gastric mucosa and muscle layer was significantly greater in these hypertensive strains, and histologically noradrenergic innervation in the mucosa was also denser in SHRSP and SHR. Choline acetyltransferase activity in the stomach was significantly lower in SHR and SHRSP than WKY (P < 0.01). These findings suggest that susceptibility of stress-induced ulcer is inversely correlated with systemic blood pressure and that the alteration of autonomic nervous function contributes to inhibition of stress ulcers by suppressing acid secretion and motility in the hereditary hypertensive rats.

Adrenergic Fibers↗

PubMed1994

Histologic activity of the liver in children with transfusion-associated chronic hepatitis C.

Adults with chronic hepatitis C develop cirrhosis over a period of 6 to 20 years, but there are few reports of this disorder in children. To determine the histologic activity of chronic hepatitis C in children, we examined 31 biopsy specimens from 25 children (age range 3-16 years) with this disease. All patients were seropositive for antibody to hepatitis C virus by second-generation testing, and for HCV-RNA by the polymerase chain reaction. All cases were transfusion-associated. Patients were divided into two groups according to underlying disease: malignant disease or aplastic anemia (Group A, 17 cases) and non-malignant disease (Group B, eight cases). All patients in Group A, but only one in Group B, had received multiple transfusions. All patients in Group A had received intensive courses of cytotoxic and immunosuppressive agents. The histologic diagnosis was made using the standard criteria and Knodell's histology activity index. Chronic persistent hepatitis was more common in Group B (six patients) than in Group A (three patients). Chronic aggressive hepatitis 2B was found only in Group A (five patients). The mean histology activity index score was higher in Group A than in Group B (8.5 vs. 5.7). Six patients (four in Group A and two in group B) subsequently had a liver biopsy. The pathological diagnosis did not change after the second biopsy in any patient in Group B, while two patients in Group A showed a rapid progression of hepatitis. In each category of the histology activity index, periportal necrosis and intralobular necrosis were more severe in Group A than in Group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Spontaneous pancreatitis in spontaneously hypertensive rats.

The pancreatic lesions in 6- to 36-week-old spontaneously hypertensive rats (SHR), stroke prone SHR (SHRSP) and Wistar-Kyoto rats (WKY) were examined histopathologically. Inflammatory cell infiltration with hemorrhage and stromal fibrosis became evident in 12-week-old SHR and SHRSP together with acinar atrophy and/or degeneration and ductular proliferation. These changes in SHR and SHRSP were even more prominent at the age of 24 weeks and extremely severe at 36 weeks. In addition, in SHR and SHRSP over 12 weeks of age, small necrosis of acinar cells was found occasionally together with fibrosis and arteriosclerosis. Pancreatic arteriosclerosis was marked in SHR and SHRSP over 24 weeks of age at the level of arterioles < 200 microns in diameter. Adrenergic nerve fibers stained by fluorescence histochemistry were present around the pancreatic arteries and ducts and within the parenchyma, and they were denser in SHR and SHRSP than in WKY, indicating hyperinnervation of the sympathetic nervous system in SHR and SHRSP. It is suggested that the pancreatic ischemia caused by arteriosclerosis due to facilitation of the sympathetic nervous system is an important factor in the pathogenesis of the spontaneous pancreatitis of SHR and SHRSP.

Animals↗

PubMed1994

Bone marrow transplantation for erythroleukemia: a case report.

A 2 year old girl was diagnosed as having erythroleukemia (EL; M6 according to the French-American-British classification). After one course of low-dose cytosine arabinoside (Ara-C), complete remission was obtained. After three courses of low-dose Ara-C for consolidation, allogeneic bone marrow transplantation was performed from HLA-identical sibling. The course of post-transplantation was uneventful. Two years after transplantation, she continues to have durable engraftment and remission. In children with EL, conventional chemotherapy appears to be inadequate for producing durable long-term disease-free survival. Bone marrow transplantation should be considered in children with EL, in cases where suitable donors are available.

Bone Marrow Transplantation↗

PubMed1994

Increased expression of human 63-kD heat shock protein gene in Kawasaki disease determined by quantitative reverse transcription-polymerase chain reaction.

To investigate the possible role of heat shock protein (HSP) in the pathogenesis of Kawasaki disease (KD), we determined the expression of 63-kD HSP (P1 protein) gene in the leukocytes from the peripheral blood of 20 patients with KD, 20 patients with various other febrile diseases, and 10 healthy children using the quantitative reverse transcription-polymerase chain reaction technique. Although a low but constitutive expression of HSP was observed in the control patients and healthy children, the expression of HSP63 mRNA was significantly higher during the acute phase of KD. Because mycobacterial HSP65, a cognate of human HSP63, is a common immunogen in bacterial species, and because the major immunopathologic feature of KD is reportedly an abnormally activated immune system, it suggests that an increased level of HSP63 gene transcription may be associated with the pathogenesis of KD.

Base Sequence↗

PubMed1994

Expression of parathyroid hormone-related peptide in relation to perturbations of gastric motility in the rat.

We studied the expression of PTH-related peptide (PTHrP) and its mRNA in rat gastric smooth muscle in relation to various gastric motility states. Male rats were divided into groups subjected to fasting, feeding ad libitum, cold restraint stress, pyloric ligation, and carbachol stimulation. Cold restraint stress induced abnormal contractions. Rhythmic and moderate contractions were produced by carbachol administration, and marked distension was induced by pyloric ligation. PTHrP mRNA expression was weak in the physiological fasting and feeding states, but was markedly increased by pyloric ligation and carbachol stimulation. PTHrP and its mRNA were localized to the proper muscle layer and muscularis mucosa, but not in the mucosa by immunohistochemistry and in situ hybridization. The gene expression of PTHrP receptor in the gastric tissue was confirmed by reverse transcription-polymerase chain reaction, but serum PTHrP levels did not increase in all groups. These findings suggest that PTHrP acts as an autocrine or paracrine factor in gastric smooth muscle that responds to muscle activity caused by distension and cholinergic stimulation. However, PTHrP gene expression was decreased by stress despite the presence of strong contractions, and the sufficient relaxation did not occur. PTHrP suppression by stress is caused by the increase in corticosterone, as pretreatment of metyrapone, an inhibitor of 11 beta-hydroxylation, enhanced PTHrP gene expression in association with serum corticosterone suppression. In conclusion, PTHrP might be an important gastrointestinal peptide that regulates gastric contractile activity and is influenced by the serum corticosterone level.

Animals↗

PubMed1994

Goblet cell carcinoid of the appendix.

A 47-year-old man was admitted with appendicitis, and appendectomy was performed. On microscopic examination of the resected specimen, the presence of goblet cell carcinoid in the tip of appendix was revealed. This tumor showed an aggressive nature with perineural and vascular invasion around the appendiceal serosa. The tumor was composed of two main cell populations: mucin-producing (goblet cell type) and silver-positive cells (endocrine differentiation). Additionally, a few cells were also positive for serotonin and lysozyme, but negative for gastrin and ACTH. These findings suggest that goblet cell carcinoid share some functional and histologic characteristics with carcinoid tumors and adenocarcinomas, although it is a distinct entity.

Appendectomy↗

PubMed1994

Gastric mucosal blood flow in relation to stress-induced hypercontraction in spontaneously hypertensive rats.

The spontaneously hypertensive rat (SHR) is a widely used animal model for essential hypertension, and is less susceptible to cold restraint stress in gastric ulcer formation. We previously reported that acid secretion is low in SHR due to sympathetic facilitation compared with normotensive Wistar-Kyoto rats (WKY). The purpose of this study was to evaluate the autonomic nervous function and the gastric mucosal blood flow related to gastric motility during cold restraint stress in SHR. Male SHR and WKY, 24-28 weeks old, were used in this study. Noradrenergic innervation, noradrenaline and dopamine contents in the muscle layer were significantly greater in SHR than in WKY, and tissue choline acetyltransferase activity was significantly lower in SHR. Gastric motility was markedly enhanced by cold restraint stress in WKY. By contrast, SHR maintained the rhythmic and low amplitude contractions regardless of hypothermia. Mucosal blood flow decreased markedly during hypothermia in WKY but was well sustained in SHR. In conclusion, the increase in gastric motility associated with cold restraint stress was suppressed in SHR by sympathetic facilitation in the muscle layer, and this may have contributed to the prevention of ulcer formation by maintaining mucosal blood flow in SHR.

Animals↗

PubMed1994

[Laboratory and clinical studies on combined effects of fosfomycin plus sulbactam/cefoperazone for mixed infections of MRSA and Pseudomonas aeruginosa].

The time-lag/sequential/step by step chemotherapy by fosfomycin plus sulbactam/cefoperazone including a short time small dose of steroid was done for 27 severely infected patients suffered from various cancer or other severe basal diseases. And the staggered "intensive" chemotherapy with added arbekacin or vancomycin to the previous staggered chemotherapy was done against 13 severely infected patients having MRSAs among their infecting pathogens. 1. Bacteriological effects Pseudomonas aeruginosa 6/8, Staphylococcus epidermidis 5/5, Enterococcus faecalis 3/6, Acinetobacter calcoaceticus 2/2, Klebsiella pneumoniae 2/2, MRSA 2/2, Xanthomonas maltophilia 2/3 and other 10/10 were eradicated (84.2%) by the staggered chemotherapy and MRSA 7/13, P. aeruginosa 3/4, E. faecalis 3/5, A. calcoaceticus 2/2, X. maltophilia 1/1 and others 2/2 were eradicated (53.8% in MRSA, 78.6% in others and 66.7% in total) and 3 of MRSAs were colonized. 2. Clinical effects 1) Staggered chemotherapy: Excellent 18/27, good 8/27, fair 1/27, poor 0/27 (96.3%). 2) Staggered "intensive" chemotherapy: Excellent 6/13, good 4/13, fair 2/13, poor 1/13 (76.9%) in total: excellent 60.0%, efficacy rate 90.0%.

Adult↗

PubMed1994

[Laboratory and clinical study on combined effects of fosfomycin plus sulbactam/cefoperazone for mixed infections of MRSA and Pseudomonas aeruginosa].

Pseudomonas aeruginosa has been a major bacterial partner when MRSA (Methicillin-resistant Staphylococcus aureus) is isolated clinically. Hence, we studied the in vitro combined effect of fosfomycin (FOM) plus sulbactam/cefoperazone (SBT/CPZ) against mixed infections of MRSA and P. aeruginosa. The combined effect of FOM plus SBT/CPZ was observed through an FIC index using the checkerboard method, log reduction of colony counts on the time killing curve, and morphological changes observed using scanning electron micrography. Under serum concentration at 3 hours after administration in consider of pharmacokinetics, the combination effect was also evaluated. Furthermore, we evaluated a time-lag combination therapy in which FOM is administered 60 minutes before SBT/CPZ administration for mixed infections. Synergistic effects of FOM plus SBT/CPZ were clearly observed against mixed infections of MRSA and P. aeruginosa. Log reduction of colony counts on the time killing curve seemed to be an appropriate indicator in the evaluation of synergistic effects.

Aged↗

PubMed1993

Noradrenergic and neuropeptide Y-immunoreactive nerves in the pancreatic islets of spontaneously hypertensive rats.

Innervation by noradrenergic (NA) and neuropeptide Y-immunoreactive (NPY-IR) nerves to the pancreatic islets and the arteries supplying the islets was studied by immunocytochemistry in 6- and 20-week-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Since both the NA and NPY-IR nerves follow the intra- and interlobular small arteries and innervate the islets, we examined mainly the innervation of intra- and interlobular small arteries by these nerves. The NA nerve density of the intralobular small arteries supplying the islets was significantly more extensive in 6-week-old SHR than in age-matched WKY (7.11 +/- 1.78 vs. 4.04 +/- 0.71 x 10(-2) micron/micron2, P < 0.001), and the NPY-IR nerve density of the intralobular small arteries was significantly more extensive in SHR than in WKY at 6 weeks of age (7.68 +/- 2.28 vs. 5.69 +/- 0.91 x 10(-2) micron/micron2, P < 0.05). The interlobular small arteries branching off the intralobular small arteries in SHR were also more innervated by NA (P < 0.05) and NPY-IR nerves (P < 0.001) than by those in WKY at 6 weeks of age. At 20 weeks of age, the NA and NPY-IR nerve densities of the intra- and interlobular small arteries were higher in SHR than in WKY, and showed an increase with age in both strains. In addition, the islet innervation by these nerves in cross-section appeared denser in SHR than in WKY.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Gastric motility and ischemic changes in occurrence of linear ulcer formation induced by restraint-water immersion stress in rat.

The pathogenesis of linear ulceration induced by restraint water-immersion (RWI) was investigated in view of gastric motility and early ischemic changes. After three hours of restraint-water immersion stress, the cross-sectioned gastric body was prepared for light microscopy. Most lesions (90.8%) were present in the mucosal folds projecting toward the cavity. Wedge-shaped degeneration in the crest of the folds was recognized as an ischemic lesion followed by hemorrhagic ulceration. Compressed arterioles were frequently encountered in the muscularis mucosae and circular muscle. Generally, mucosal folds appear merely with the reduction of gastric content, and run along with the elevation of the circular muscle as an anatomical structure, becoming tall and steep after RWI. Marked enhancement of contraction, observed with a strain gauge force transducer, was induced by RWI. This enhancement was suppressed by papaverine HCl pretreatment in accordance with suppression of the fold-related mucosal lesion even after 150 mM HCl perfusion into the stomach. In conclusion, gastric motility appears to play an important role in the pathogenesis of linear ulceration by causing ischemic change along the folds.

Animals↗