Biomedical subjects

S Mizuno

Publications and source records attributed to S Mizuno.

At least 829 records · Page 46Linked to original sources

PubMedDate not supplied

Nonpathological focal enhancements on spiral CT hepatic angiography.

BACKGROUND: To assess the frequency and characteristics of nonpathological focal enhancements seen on spiral computed tomographic (CT) hepatic angiography (CTA). METHODS: Spiral CTA and spiral CT arterial portography (CTAP) were performed in 31 patients with suspected liver malignancy prior to potential liver resection. The CTA images were retrospectively reviewed for focal enhancements by two radiologists. After determining nonpathological focal enhancements on CTA images based on the other radiographic tests, surgical exploration including intraoperative sonography, follow-up imagings, the frequency, size, site, and shape of nonpathological focal enhancements with CTA were assessed. RESULTS: Thirty-six nonpathological focal enhancements with CTA from 4 to 23 (mean = 11. 4) mm were seen in 14 (45.2%) of 31 patients. Thirteen (36.1%) of 36 nonpathological focal enhancements with CTA were not depicted with CTAP. Nonpathological focal enhancements with CTA were frequent in Couinaud segments III (27.8%), V (22.2%), and VI (19.4%). Twenty-three (63.9%) of 36 nonpathological focal enhancements were located in the edge of the liver. Shapes of 36 nonpathological focal enhancements with CTA included circular (n = 16), worm (n = 7), irregular (n = 6), dot (n = 6), and wedge (n = 1). CONCLUSION: In nearly half of patients, spiral CTA shows various shapes of small nonpathological focal enhancements more frequently in the liver edge.

Aged↗

PubMedDate not supplied

Methodological assessment of combined spiral CT angiography and CT arterial portography.

BACKGROUND: To assess an optimal methodology of combined spiral computed tomographic (CT) angiography (CTA) and CT arterial portography (CTAP) for detection and characterization of liver tumors. METHODS: We performed spiral CTAP only in five patients with 30-32% contrast (subset A), CTAP combined with preceding spiral CTA using 30-32% contrast in 19 (subset B), and CTAP combined with preceding spiral CTA with 60-64% contrast in seven (subset C). The CT numbers of the aorta immediately before preceding CTA and subsequent CTAP and the CT numbers of malignant tumor and liver parenchyma with CTAP were measured. RESULTS: The differences of the CT number between the malignant tumor and liver parenchyma on CTAP were 61.1-161.8 (mean +/- SD, 114.5 +/- 39.3) HU, 50.7-164.8 (104.2 +/- 31.2) HU, and 101.2-368.3 (219.5 +/- 90.5) HU in subsets A, B, and C, respectively. Two cavernous hemangiomas showed pathognomonic findings with preceding CTA. CONCLUSION: Combination of preceding spiral CTA and subsequent spiral CTAP using 30% contrast with a 5-min interval is an optimal method for detection and characterization of liver tumors.

Aged↗

PubMedDate not supplied

Potential anti-depressive effects of thyrotropin releasing hormone (TRH) and its analogues.

The anti-depressive effects of thyrotropin releasing hormone (TRH) and its analogues (DN-1417: gamma-butyrolactone-gamma-carbonyl-histidyl-prolinamide citrate; MK-771: L-pyro-2-aminoadipyl-histidyl-thiazolidine-4-carboxamide) were examined in behavioral despair rats, an animal model of depression. TRH, DN-1417, MK-771, amitriptyline and diazepam were injected three times after the first forced swimming. One hr after the last injection, a 5-min swimming test was performed. Experimental animals were placed in a Hall's type open-field apparatus immediately before and after the 5-min test, and their locomotor activities were determined. No significant difference was noted in the locomotor activity immediately before the 5-min test among any group. In the 5-min swimming test, TRH, DN-1417 and MK-771 caused a dose-dependent decrease in immobility, showing an anti-depressive effect similar to amitriptyline. Diazepam showed no difference compared with the control group. After the swimming test, locomotor activity remarkably decreased in the control rats, while decreased locomotor activity was partially prevented in the TRH, DN-1417, MK-771 and amitriptyline treated rats which exhibited active movement not only during the swimming period but also after it. In terms of the minimum effective dose, TRH and DN-1417 seemed to be of similar potency, while MK-771 was 40-fold stronger than TRH. An examination of a possible correlation between the cross-reactivity of TRH analogues in a radioreceptor assay and the effects of the analogues on despair rats suggested that the structure-binding relationship was proportional to the structure-activity relationship.

Amitriptyline↗

PubMedDate not supplied

Chronic dihydroergotoxine administration sets on receptors for enkephalin and thyrotropin releasing hormone in the aged-rat brain.

Dihydroergotoxine (DHET) is comprised of equal part of the mesylates of dihydroergocristine, dihydroergocornine and dihydroergocryptine. In the standard radioreceptor assays, DHET components displaced the CNS-receptor binding of [3H]-enkephalin (ENK) and [3H]thyrotropin releasing hormone (TRH). The inhibitory effect of DHET on ENK binding was competitive, and an allosteric effect seems to be involved in the DHET inhibition of TRH binding to its receptor. Intraperitoneal injections of DHET (1 mg/kg/day) to aged rats for 14 days resulted in a significant increase of ENK and TRH binding in the cerebral cortex. Scatchard plots of saturation experiments indicate that the increase of ENK binding is due to the increased affinity of the binding sites, and the increase of TRH binding reflects an increase in numbers of binding sites. The results suggest that the therapeutic efficacy of DHET is derived initially from its effects on the ENK and TRH receptors especially in the cerebral cortex, which in turn influence the function of monoaminergic neurons.

Aging↗

PubMedDate not supplied

Evaluation of endoscopic ultrasonography in the pre-operative staging of carcinoma of the ampulla of Vater and common bile duct.

Endoscopic ultrasonography (EUS) was performed in 23 patients with carcinoma of the ampulla of Vater (ampulla) and in 16 patients with common bile duct (CBD) carcinoma. These patients all underwent surgery. The layered structures of the duodenum, ampulla, and CBD, and the pancreas, portal vein, and regional lymph nodes were clearly identified by EUS using a transduodenal approach. With this technique, ampullary carcinoma appeared as a hypoechoic mass in 22 of 23 patients, and the 1 remaining cancer was not detected because of its small size. Carcinoma of the CBD also appeared as a hypoechoic mass in 12 of 16 patients. However, the remaining four appeared as hyperechoic masses. For these tumors, EUS had a high tumor detection rate (96 to 100%). In this regard, EUS was comparable to ERCP and was better than ultrasonography (US), CT, and angiography. Using EUS, we were also able to stage the extent of these tumors according to the involvement of the duodenal or CBD walls, invasion of the pancreas and portal vein, and spread to regional lymph nodes. The accuracy rates of cancer extent by EUS were 78% for ampullary carcinoma and 81% for CBD carcinoma when compared with surgical findings. We conclude that EUS is a valuable method for the detection and staging of tumors of the ampulla and CBD.

Ampulla of Vater↗

PubMedDate not supplied

Perfusion of medium improves growth of human oral neomucosal tissue constructs.

Tissue engineering of the oral mucosa may be useful in congenital cleft palate repairs, defects following extirpative oncologic surgery, and periodontal disease. One of the limitations of in vitro growth of oral mucosal constructs is central necrosis of 3-dimensional tissues. We tested the hypothesis that medium perfusion would enhance oral mucosal histogenesis in vitro. Normal human oral keratinocytes were obtained from young to middle-aged adults. Porous 3-dimensional matrices were prepared from collagen and chondroitin sulfate with some crosslinked with glutaraldehyde. Each device was seeded with 5.0 x 10(5) human oral keratinocytes. The seeded matrices were cultured with or without perfusion of medium at 1.3 ml/min. Histologic analysis of samples cultured for 3, 7, or 14 days showed superior viability and proliferation when perfused. At day 7, the average number of cell layers of the neoepithelium of sponges in the perfused culture system (9.4 +/- 1.0) was 88% greater than for the nonperfused culture system (5.0 +/- 0.9, p<0.005). Glutaraldehyde crosslinking did not influence cellular proliferation or the extent of matrix's shrinkage in either culture system. This study shows that medium perfusion enhanced cell viability and proliferation of human oral keratinocytes cultured in porous 3-dimensional matrices.

Cell Division↗

PubMedDate not supplied

Analysis of cost and assessment of computerized patient record systems in Japan based on questionnaire survey.

PURPOSE: The purpose of this study was to clarify the implementation and maintenance costs of a computerized patient record (CPR) system by means of a questionnaire survey. Moreover, the benefits of CPR systems were evaluated to determine their contribution to enhancing the quality of medical care and hospital management. METHODS: Data were collected by a questionnaire survey mailed out to participants. RESULTS: The per-bed mean cost for implementation was 14,308 dollars (range: 3538-38,077 dollars). The mean annual maintenance cost for the CPR system was 457,615 dollars (range: 39,769-2,307,692 dollars). The multivariate analysis (Hayashi's Quantification Type I) revealed high partial correlation coefficients between implementation cost and the CPR system maker. In addition, the multiple correlation coefficient for four factors (CPR system maker, number of servers, institution type and implementation date) in predicting implementation cost was 0.798. Over 60% of respondents replied that their satisfaction with the CPR system was 'very high' or 'high.' Eighty-two percent of the hospitals responded positively that CPR systems improve the quality of medical care, and 70% felt that the systems help prevent medical errors. CONCLUSIONS: Our findings indicate that the maker of CPR system, number of servers, institution type and implementation date had a strong influence on per-bed implementation costs in that order. Finally, it was found that CPR systems were considered effective for hospital administration and medical examinations, based on the high assessments of the results of installing a CPR system.

Costs and Cost Analysis↗

PubMedDate not supplied

Identification of the sex of a wide range of Carinatae birds by PCR using primer sets selected from chicken EE0.6 and its related sequences.

A 0.6 kb EcoRI fragment (EE0.6), cloned from the W chromosome of chickens, is a nonrepetitive sequence and contains an exonlike sequence, ET15, which is likely a part of a pseudogene. The EE0.6 sequence is conserved in all species of birds examined both in Carinatae and Ratitae. A counterpart sequence of EE0.6 is present on the Z chromosome. The extent of diversity between the W- and Z-linked sequences are variable among species. The W- and Z-linked EE0.6 sequences, cloned from 12 different species, were compared and four forward and three reverse primers were selected to amplify parts of the EE0.6 sequence by polymerase chain reaction (PCR). By choosing a suitable combination of primers for EE0.6 and a set of primers for a Z/W-common sequence, as an internal control, the sex of 36 species belonging to 16 different orders of Carinatae could be determined clearly by PCR. The sex of two other species representing different orders could be determined by Southern blot hybridization using ET15 as a probe. For the two Ratitae species, emu and ostrich, EE0.6 sequences on W and Z chromosomes could not be distinguished either by PCR or Southern blotting.

Animals↗

PubMedDate not supplied

Variation of repetitive DNA and its phylogenetic relation in Hynobiidae (Caudata).

Middle repetitive (MR) DNA comprising about 35% of the genomic DNA of Hynobius retardatus was isolated and used as mixed probes. A 1.3-kb Bam HI fragment, the major repeating unit of the extensively amplified sequences in H. retardatus, was cloned, sequenced, and used as a probe. Dot blot hybridization under the conditions of probe excess revealed that the MR DNA sequences were shared among the three salamander genera belonging to the family Hynobiidae. However, a large difference in the amount of common sequences was found between Hynobius and Salamandrella, and large differences in both amounts and sequence similarity were found between Hynobius and Onychodactylus. Even among species belonging to the genus Hynobius, relative contents of sequences common to the H. retardatus MR DNA were 20% to 50%. Partially related sequences to the 1.3-kb sequence seemed to be present in all the species of Hynobius and Salamandrella, but the extensive amplification was found only in H. retardatus. Based on the relative contents of the common MR DNA and previously reported chromosomal banding characteristics, species in the genus Hynobius are classified into at least three groups. An evolutionary aspect of the emergence of the amplified sequence in H. retardatus is discussed.

Animals↗

PubMedDate not supplied

Performance of a new hybrid artificial liver support system using hepatocytes entrapped within a hydrogel.

To develop a hybrid artificial liver support system (ALSS), the authors constructed a rotating-disk type ALSS using hepatocytes entrapped within a calcium alginate hydrogel. This module was designed in imitation of the gas-liquid contactor that uses the same principle. Forty disks with film-shaped hydrogel were mounted to a horizontal rotating axis and were kept in contact with blood. The concentration of hepatocytes in the gel varied from 1.9 X 10(9) to 1.7 X 10(10) cells/L gel. Entrapping hepatocytes within hydrogel kept the hepatocytes viable, and results of in vitro experiments showed ammonium metabolism and urea synthesis. The results of ex vivo perfusion experiments using cats with acute hepatic insufficiency indicated that this module had the ability to replace liver function in vivo.

Ammonia↗

PubMedDate not supplied

Low-dose doxapram therapy in premature infants and its CSF and serum concentrations.

The efficacy of low-dose doxapram therapy (0.2 mg/kg/h) in combination with methylxanthines was evaluated in 20 premature infants with idiopathic apnea unresponsive to methylxanthines alone, and in 13 premature infants with secondary apnea. The serum concentrations of doxapram and, in some infants, the simultaneous cerebrospinal fluid and serum concentrations were measured, and the correlation between cerebrospinal fluid and serum concentrations in the postnatal period was determined. The following results were obtained: 1) In idiopathic apnea of prematurity, low-dose doxapram therapy was as effective as a dose of 1.0-2.5 mg/kg/h and the side effects were few, mild, and reversible. 2) In premature infants over seven days of age, serum concentrations of doxapram were almost stable but were significantly lower than in infants within the first six days of life. 3) The ratio of the cerebrospinal fluid to serum doxapram concentration was 0.48 +/- 0.13 (mean +/- SD). There was a good correlation between cerebrospinal fluid and serum concentrations (r = 0.933, p less than 0.001). The initial doxapram dose can be set as low as 0.2 mg/kg/h in very young premature infants with idiopathic apnea of prematurity unresponsive to methylxanthines.

Aminophylline↗

PubMedDate not supplied

Triple therapy with omeprazole, amoxicillin and clarithromycin is effective against Helicobacter pylori infection in gastric ulcer patients as well as in duodenal ulcer patients. Results of a randomized controlled trial in Japan.

BACKGROUND/AIMS: There have been few reliable published studies permitting assessment of therapeutic regimens for Helicobacter pylori infection in gastric ulcer (GU) patients. The aim of the present study was to evaluate the efficacy of omeprazole-based dual and triple therapy regimens, both including clarithromycin, for the cure of H. pylori infection in active GU and duodenal ulcer (DU) patients. The study was conducted in Japan, a country in which GU is more prevalent than DU. METHODS: Two hundred and thirty-four consecutive peptic ulcer patients (GU: n = 124; DU: n = 103; GDU: n = 7) suffering from H. pylori infection were randomly treated with either omeprazole 20 mg b.i.d. + amoxicillin 500 mg q.i.d. + clarithromycin 400 mg b.i.d. (OAC) or with omeprazole 20 mg b.i.d. + clarithromycin 400 mg b.i.d. (OC) for 14 days. H. pylori infection was evaluated by histology and culture from antral and corpus biopsies 6 weeks after completing antimicrobial therapy. RESULTS: Follow-up data were available in 202 patients. The cure rates of H. pylori infection in GU patients were 83.9% (47/56) with OAC and 59. 2% (29/49) with OC. Corresponding rates in DU patients were 91.5% (43/47) and 70.5% (31/44), respectively. The cure rates with OAC were significantly higher than those with OC (p < 0.001, chi2 test). The cure rates in GU patients were lower than those in DU patients for both regimens, but these differences were not statistically significant. Side effects were generally mild and did not interfere with compliance. One patient in the OAC group and 2 patients in the OC group complained of severe side effects that led to therapy discontinuation. CONCLUSIONS: Triple therapy with omeprazole, amoxicillin and clarithromycin is a safe and effective regimen for the cure of H. pylori infection in GU patients as well as in DU patients. We recommend this triple regimen as a first-line treatment in all patients with peptic ulcers associated with H. pylori infection in Japan.

Adolescent↗

PubMedDate not supplied

Effects on health of dietary supplementation with 100 mg d-alpha-tocopheryl acetate, daily for 6 years.

To evaluate the clinical antioxidant effects of vitamin E, 161 healthy volunteers aged 39 to 56 years, were given 100 or 3 mg of d-alpha-tocopheryl acetate orally daily for 6 years using a randomized, double-blind design. Among the 147 volunteers who qualified for the analysis, seven of the 73 volunteers receiving 3 mg d-alpha-tocopheryl acetate daily and none of the 74 volunteers receiving 100 mg had coronary disorders including myocardial damage (P < 0.02). ST or T wave abnormalities on electrocardiograms were considered to indicate coronary disorders (four volunteers). The mean serum total tocopherol (TOC) concentration in the 100-mg group was significantly higher than that in the 3-mg group 6 months after the start of the study, and this raised value was maintained throughout the study; the level in the 3-mg group did not change significantly from the baseline value. The low-density lipoprotein cholesterol/total TOC ratio, a parameter of the inhibition of peroxidation of low-density lipoprotein cholesterol, was the only serum lipid parameter that was significantly different, at baseline, in the volunteers with coronary disorders compared with the others. These findings indicate that long-term supplementation with 100 mg tocopheryl acetate daily may prevent the early stages of coronary atherosclerosis by decreasing peroxidation of low-density lipoprotein cholesterol.

Adult↗

PubMedDate not supplied

Perfusion enhances functions of bone marrow stromal cells in three-dimensional culture.

Perfusion of medium through three-dimensional (3D) collagen sponges enhanced viability and function of cocultivated marrow stromal and hematopoietic cell lines. Cells of the murine bone marrow stromal cell line GPIa were cultured in novel 3D collagen sponges, made from pepsin-digested bovine skin. Static cultures of sponges were maintained in dishes with media changes every other day. Perfused sponges were contained in a glass column with medium flow set at 1.3 mL/min. In some sponges, the 32D cl3 c-fms(m) (CRX-1) hematopoietic progenitor cell line was added 7 days after GPIa cells. At 7 and 16 days, light microscopic evaluation showed poor viability of cells in static sponge cultures. In perfused sponge cultures, there was greater cellularity throughout the sponge and abundant accumulation of metachromatic extracellular matrix surrounding GPIa cells. Chondroitin 6-sulfate and heparan sulfate were identified as components of the matrix by immunohistochemical methods. DNA synthesis was evaluated by 15-h exposure of cultures to bromodeoxyuridine (BrdU), with subsequent immunohistochemical localization with monoclonal anti-BrdU antibody. Cells positive for BrdU were identified at the outer surfaces of both static and perfused sponges; however, positive cells were also seen throughout the internal areas of the sponges that were perfused. These results suggest that better nutrient exchange occurred in perfused sponges. In static cocultures of GPIa and CRX-1 cells, there was no detectable viability of the IL-3-dependent CRX-1 cells; however, under perfused conditions, CRX-1 cells flourished within the sponges as documented by BrdU incorporation. Thus, medium perfusion enhanced GPIa stromal cell line viability and function in 3D collagen sponge cultures, as demonstrated by BrdU incorporation, matrix production, and support of CRX-1 cells. This novel culture system may be useful for examining the interactions of bone marrow stromal cells with extracellular matrix molecules, soluble and matrix-bound factors, and with other cell types.

Animals↗

PubMedDate not supplied

Leukemia and other malignancies among GH users.

The number of reported cases of leukemia developing in growth hormone (GH) users worldwide has reached 31. Twelve Japanese cases are briefly reviewed; five each of AML and ALL, and one each of CML and malignant histiocytosis. The underlying diseases of these patients consisted of 8 idiopathic disease, 3 tumors and one Fanconi's anemia. Leukemia occurred during GH treatment in 9 cases and after cessation of GH in 3. The longest interval from the cessation of GH therapy was 10 years. GH administration from a younger age tended to be linked to myeloid type. Risk factors and possible mechanisms of leukemogenesis by growth hormone are discussed, and proposals for the future have been made by the Foundation for Growth Science in Japan.

Acute Disease↗

PubMedDate not supplied

Defect in the development of thermotolerance and enhanced heat shock protein synthesis in the mouse temperature-sensitive mutant ts85 cells upon moderate hyperthermia.

The effect of exposure to moderate hyperthermia on the induction of thermotolerance and heat shock protein (HSP) synthesis was investigated using mouse FM3A cells and the temperature-sensitive mutant ts85 cells. The thermal sensitivity of the two cell lines was markedly different; the mutant ts85 cells were more sensitive than the parental wild-type FM3A cells to heating at 41 and 44 degrees C. The shift-up treatment of FM3A cells for 3 h at 39.5 degrees C from 33 degrees C induced thermotolerance development to subsequent heating at 44 degrees C, with little if any enhancement of major HSP synthesis. On the other hand, the similar treatment of ts85 cells at the non-permissive temperature of 39.5 degrees C induced significantly enhanced HSP synthesis, but could not induce thermotolerance. The exposure to 41 degrees C also induced thermotolerance in the wild-type cells, but failed to induce tolerance in the mutant ts85 cells. These results suggest that enhanced major-HSP synthesis is neither a sufficient or necessary condition for thermotolerance development upon moderate heat shock. The mechanism of thermotolerance is discussed by relating the observed defect in thermotolerance development to the known defect in ubiquitin-dependent protein degradation system of the mutant ts85 cells at non-permissive temperature.

Animals↗

PubMedDate not supplied

Possible involvement of ubiquitin function and ATP requirement in the development of thermotolerance in mammalian cells.

Thermotolerance under chronic exposure to moderate hyperthermia at 41 degrees C was hardly induced in the mouse temperature-sensitive mutant ts85 cells, in contrast to the parental wild-type FM3A cells. Thermotolerance was induced at a reduced level in the mutant cells compared with the wild-type cells by incubation at 33 degrees C (permissive temperature), but not at 39 degrees C (non-permissive temperature), after a brief exposure at 44 degrees C. Under conditions where protein synthesis was inhibited by cycloheximide at 41 degrees C, significant amounts of thermotolerance developed in FM3A cells. FM3A cells depleted of cellular ATP by treatment with 2.4-dinitrophenol and 2-deoxyglucose were not sensitized to thermal cell killing at 44 degrees C, when drug-treated cells were washed and exposed to hyperthermia in drug-free growth medium, where cellular ATP rapidly recovered. However, the cells deprived of ATP under the treatment at 41 degrees C failed to develop thermotolerance, indicating a requirement of ATP for thermotolerance development. The decay of thermotolerance was not affected by ATP levels after it was developed. The degradation of abnormal cellular proteins which contained amino acid analogues was promoted at 33 degrees C relative to normal protein degradation in FM3A and ts85 cells. Both normal and abnormal proteins were degraded at a reduced rate at 43 degrees C. Pretreatment of cells at 41 degrees C decreased the rate of degradation of abnormal proteins at 33 degrees C by 20% in FM3A cells and by about 100% in ts85 cells. Pretreatment of cells at 41 degrees C increased significantly the conjugation of 125I-labeled ubiquitin to cellular endogenous proteins in extracts of FM3A cells, but decreased the conjugation in extracts of ts85 cells. The data presented here, in conjunction with the observations by others that the ts85 cell is a mutant defective in the ubiquitination of cellular proteins at nonpermissive temperatures, suggest that the ATP-dependent ubiquitination may be crucial for the development of thermotolerance.

2,4-Dinitrophenol↗

PubMedDate not supplied

Sporostatin, a novel and specific inhibitor of EGF receptor kinase.

Sporostatin isolated from a fungus of Sporormiella sp.M5032 as an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase, was found to be a specific inhibitor of epidermal growth factor (EGF) receptor tyrosine kinase in vitro. Its IC50 values were 0.1 microgram/ml (0.38 microM) for EGF receptor kinase, 3 micrograms/ml (11 microM) for ErbB-2, and 100 micrograms/ml (380 microM) or more than that for other kinases including PDGF receptor, v-src and protein kinase C. Kinetic analyses revealed that inhibition of EGF receptor kinase by sporostatin was noncompetitive either with substrate or with ATP. Autophosphorylation of EGF receptor in A431 cells was also inhibited. These results show that sporostatin is a potent and specific inhibitor of EGF receptor kinase.

Angiotensin II↗