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Biomedical subjects

Y Sakamoto

Publications and source records attributed to Y Sakamoto.

At least 91 records · Page 5Linked to original sources
PubMed2000

Ischemic hepatitis induced by mesenteric volvulus in a patient with chronic obstructive lung disease.

A 66-year-old man with chronic obstructive lung disease was admitted to our hospital, presenting with mesenteric volvulus and mild liver injury. A superior mesenteric angiogram revealed that the arteries supplying the small intestine were twisted in the arterial phase, while the portal vein was not visualized in the late phase. A celiac angiogram demonstrated that portal blood flow from the splenic venous return was maintained. The patient's symptoms had almost resolved the day after admission, and his serum transaminases level had gradually decreased to normal with conservative therapy. A superior mesenteric angiogram on the 13th hospital day showed a normal arteriogram and the portal vein demonstrated blood flow from the superior mesenteric vein. Liver biopsy revealed hemorrhagic necrosis around the central veins, which was compatible with ischemic hepatitis. Since the patient's O2 saturation level on admission was not low enough to have caused ischemic hepatitis by itself, we suspect that a sudden decrease in portal blood flow was the additional factor that allowed the threshold for the initiation of ischemic liver damage to be reached.

Aged↗
PubMed2000

Therapeutic effect of clarithromycin for respiratory-tract infections in children caused by Chlamydia pneumoniae. Research Group of Sapporo for Pediatric Chlamydial Infections.

Children infected with Chlamydia pneumoniae sometimes experience lower respiratory tract infections such as pneumonia and bronchitis. Although numerous anti-microbial compounds have been reported to be active against the organism, most of them have not been in a clinical trial in infants and children with C. pneumoniae infection. Clarithromycin has been shown to express anti-chlamydial effects in vitro. In this study, we evaluated the clinical anti-C. pneumoniae properties of clarithromycin in children with mainly lower respiratory tract infection. We administered clarithromycin orally to 21 infants and children at a dose of 10-15 mg/kg/day divided into two or three doses for 4-21 days. Clinical symptoms, roentgenographic and laboratory abnormal findings improved. The overall clinical efficacy rate was 85.7% (18 of 21 cases). Administration of clarithromycin was considered to be a suitable treatment for improving lower respiratory infections in infants and children caused by C. pneumoniae.

Administration, Oral↗
PubMed2000

Physicochemical properties of amorphous precipitates of cimetidine-indomethacin binary system.

We have found that the binary system, consisting of a precipitate of cimetidine and naproxen, became amorphous due to intermolecular interaction. In order to clarify the interaction between cimetidine and other drugs, the physicochemical properties of binary systems consisting of cimetidine and drugs, phenacetin, salicylamide or indomethacin, were investigated. X-ray powder diffraction patterns and thermal analysis findings for the precipitates indicated that the cimetidine-indomethacin system has an amorphous structure, whereas the cimetidine-phenacetin and cimetidine-salicylamide systems do not. Fourier-transform infra-red (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy findings suggested that there is an intermolecular interaction between a proton in the imidazole ring of cimetidine and the C=O in the COOH of indomethacin. Since an interaction by the hydrogen bond between cimetidine and indomethacin would prevent three-dimensional arrangements of the molecules, the precipitate would be amorphous. In the cimetidine-indomethacin system, decarboxylation of indomethacin occurred below the melting temperature, indicating that the chemical stability decreased upon precipitation. Cimetidine was found to interact with drugs with a carboxyl group. The interaction would be applicable to make the amorphous system of the drugs and increase the solubility of the drugs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Serum thioredoxin levels as an indicator of oxidative stress in patients with hepatitis C virus infection.

BACKGROUND/AIM: It has recently been suggested that oxidative stress may be associated with hepatitis C virus (HCV) infection. Thioredoxin (TRX) is a stress-inducible thiol-containing protein. The aim of this study was to evaluate the clinical significance of serum TRX levels in patients with HCV-related chronic liver diseases. METHODS: Serum TRX levels were determined with a sandwich enzyme-linked immunosorbent assay kit in 174 serum HCV-RNA positive patients, including 6 asymptomatic carriers, 124 chronic hepatitis, 20 liver cirrhosis, and 24 hepatocellular carcinoma, and in 15 healthy volunteers. RESULTS: The serum TRX levels (medians and [ranges], ng/ml) were significantly elevated in the HCV-infected patients; 30.9 [20.7-37.7] in asymptomatic carriers, 34.5 [8.6-135.6]* in chronic hepatitis, 42.5 [21.4-97.2]* in liver cirrhosis, and 43.9 [11.7-180.3]** in hepatocellular carcinoma (*p<0.05, **p<0.001, vs. 24.9 [1.3-50.7] in healthy controls). Serum TRX levels were significantly correlated with the serum levels of ferritin and fibrogenesis markers, and with the histological stage of hepatic fibrosis. The serum TRX levels before interferon treatment of patients whose serum HCV-RNA was still positive on day 14 following interferon treatment (42.6 [20.1-90.0]) were significantly higher than those of patients whose serum HCV-RNA was negative on day 14 following interferon treatment (25.8 [7.4-59.8], p<0.05). CONCLUSIONS: The serum TRX levels of patients with HCV infection increased with their serum ferritin levels and the progression of liver fibrosis. Patients with higher serum TRX levels exhibited resistance to interferon therapy. Oxidative stress may therefore be responsible for the pathological mechanism of HCV-related liver diseases and be one of the impediments to eradication of HCV during interferon treatment.

Adult↗
PubMed2000

Hydrogen peroxide augments eosinophil adhesion via beta2 integrin.

During eosinophil (EOS) accumulation at sites of allergic inflammation, an initial step is the binding of EOS to adhesion molecules expressed on vascular endothelial cells (EC). We have previously observed that adhesion of peripheral blood EOS to recombinant human vascular cell adhesion molecule-1 (rh-VCAM-1) stimulates the respiratory burst of EOS. Although the biological consequence of this activation remains to be elucidated, reactive oxygen species such as hydrogen peroxide (H2O2) may modify the adhesive property of EOS. In the present study, we examined whether H2O2 modifies the adhesive property of EOS. EOS were isolated from the peripheral blood of healthy subjects. Adhesion of the EOS to paraformaldehyde-fixed human umbilical vein EC (HUVEC), stimulated or not stimulated with tumour necrosis factor-alpha (TNF-alpha; 100 pM for 24 hr), was examined in the presence or absence of H2O2. H2O2 significantly enhanced adhesion of EOS to both resting and TNF-alpha-stimulated fixed HUVEC (P < 0.01, respectively). Such enhancing effects were inhibited by anti-beta2 integrin antibody or anti-CD11b antibody, but not by anti-CD11a or anti-alpha4 integrin antibody. H2O2 also enhanced EOS adhesion to rh-intracellular cell adhesion molecule-1 (ICAM-1) but not to rh-VCAM-1. Finally, H2O2 enhanced the expression of both CD11b and CD18 on EOS. These results indicate that H2O2 directly augments the adhesive property of EOS through beta2 integrin.

Adult↗
PubMed2000

Structure of a major oligosaccharide of PASII/PMP22 glycoprotein in bovine peripheral nerve myelin.

The amino acid sequence of the glycopeptide obtained from bovine PASII/PMP22 protein in the PNS myelin was determined to be Gln-Asn-Cys-Ser-Thr, where the asparagine was glycosylated. To eliminate all the contaminated P(o) glycopeptides from the PASII/PMP22 glycopeptide preparation, we used a fluorescent probe, N-[2-(2-pyridylamino)ethyl]maleimide, which reacts with the cysteine of the PASII/PMP22 glycopeptides. The labeled PASII/PMP22 glycopeptides were isolated by HPLC and were digested further with glycopeptidase A. The resultant oligosaccharides were conjugated with 2-aminopyridine (PA) as a fluorescent tag. One major PA-oligosaccharide, OPPE1, was purified by HPLC. The structure of OPPE1 was elucidated by fast atom bombardment mass spectrometry and (1)H-NMR studies and comparing the derivatives of PA-OPPE1 and PA-oligosaccharides of gamma-globulin on HPLC. The structure, SO(4)-3GlcAbeta1-3Galbeta1-4GlcNAcbeta1-2Manalpha1+ ++-6(GlcNAcbeta1-4) (GlcNAcbeta1-2Manalpha1-3)Manbeta1-4GlcNAcbeta1- 4(Fucalpha1-6)GlcNAc- PA, was identical to the pyridylaminated form of the major oligosaccharide D8 of bovine P(o) previously reported.

Amino Acid Sequence↗
PubMed2000

Acidotic pH augments glucagon secretion and gluconeogenesis in the isolated perfused rat pancreas and liver.

To study effects of acidosis on glucagon secretion and gluconeogenetic action of glucagon, rat pancreas and liver were perfused with media of pH 6.4, 6.9, 7.4 and 7.9. Glucagon secretion from the pancreas during glucopenic perfusion (1 mmol/l) was blunted at alkalotic pH, and was augmented at acidotic pH; 0.28+/-0.18 at pH 7.9 (P<0.01), 3.57+/-0.94 at pH 6.9 (P<0.01) and 1.72+/-0.36 at pH 6.4 (P<0.01), vs. 0.66+/-0.25 pmol for 15 min at pH 7.4. Incorporation rate of 14C of lactate-U-14C into glucose carbon one was decreased at pH 7.9 (1.2+/-0.2% for 15 min, P<0.05) and was increased at pH 6.9 (2.8+/-0.5%, P<0.05) compared to that at pH 7.4 (1.9+/-0.3%). Percent increasing rate of lactate gluconeogenesis by 1 nmol/l glucagon was not different within a range of pH 6.4-7.9. Thus, glucagon-stimulated gluconeogenesis from lactate was smaller at pH 7.9 (2.2+/-0.6%) and was significantly greater at pH 6.9 (4.9+/-0.9%, P<0.05) than that at pH 7.4 (3.2+/-0.6%). These results suggest that the pancreatic glucagon secretion and the glucagon-stimulated hepatic gluconeogenesis play more important roles in the maintainance of blood glucose level in the stress states associated with acidosis than without acidosis.

Acidosis↗
PubMed2000

Gastric cancer presenting with extremely rapid growth: unprecedented morphologic change in a short time and endoscopic estimation of its doubling time.

We encountered a case of gastric cancer that was initially detected as a deep hemorrhagic ulcer without surrounding irregular elevation, followed by rapid protrusion in less than 1 month. Using endoscopic images in the follow-up study, we estimated the doubling time (DT) of this unusual tumor as 9.2 days. Since the doubling time of gastric cancer is generally fairly long due to exfoliation of many cancer cells into the gastric lumen, this cancer presented with extremely rapid growth. Besides, this case reinforces that follow-up study is important in terms of clinical management of ulcerative lesions.

Aged↗
PubMed2000

Tracheoesophageal fistula after blunt chest trauma: successful diagnosis by computed tomography.

A case of tracheoesophageal fistula after blunt trauma is reported. A 27-year-old man who suffered from an automobile traffic accident complained of strong choking after drinking water. Computed tomography demonstrated a defect between the esophagus and the trachea just above the carina. Acquired tracheoesophageal fistula was suspected and promptly confirmed by contrast esophagogram. The defects of the trachea and esophagus was repaired by primary suture and buttressed using a pedicled intercostal flap. The postoperative course was uneventful.

Accidents, Traffic↗
PubMed2000

Anatomical segmentectomy of the head of the pancreas along the embryological fusion plane: a feasible procedure?

BACKGROUND: Less extensive resection of the head of the pancreas has been the procedure of choice recently for low-grade malignant neoplasms. The anatomical detail of the head of the pancreas is currently insufficient for segmental resection along the embryological fusion plane. METHODS: The anatomy of the head of the pancreas was analyzed in 31 consecutive autopsy specimens. An anterior (n = 10) or posterior (n = 10) segmentectomy of the head of each pancreas was performed along the macroscopically found fusion plane. The pancreatic arteries, the portal vein, the bile duct, and the pancreatic duct were visualized by injecting 3 silicon dyes of different colors. Another 11 specimens were examined by pancreatography before and after anterior (n = 5) or posterior (n = 6) segmentectomy. Eight of these 11 specimens were stained immunohistochemically to reveal the distribution of pancreatic polypeptide cells after segmentectomy. RESULTS: The cleavage between the anterior and posterior segments was discovered at the anterior inferior edge or at the posterior superior edge of the head of the pancreas. Anterior segmentectomy was accomplished while preserving the anterior and posterior pancreaticoduodenal arcades and the lower bile duct in the posterior segment. Posterior segmentectomy involved the removal of the lower bile duct and the posterior pancreaticoduodenal arcades. Pancreatography after segmentectomy showed the division of the ducts of Wirsung and Santorini with the peripheral branches. The immunohistochemical boundary of pancreatic polypeptide cells coincided with the surgical plane. These results showed the anterior and posterior segments were originated from the embryologically dorsal and ventral primordia, respectively. CONCLUSIONS: The current anterior or posterior segmentectomy of the head of the pancreas corresponded to the resection of the embryologically dorsal or ventral primordium, respectively. Anterior segmentectomy of the head of the pancreas might be a clinically applicable procedure; however, posterior segmentectomy involving the resection of the lower bile duct may be impractical.

Adult↗
PubMed2000

Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index.

BACKGROUND: Although international interest in classifying subject health status according to adiposity is increasing, no accepted published ranges of percentage body fat currently exist. Empirically identified limits, population percentiles, and z scores have all been suggested as means of setting percentage body fat guidelines, although each has major limitations. OBJECTIVE: The aim of this study was to examine a potential new approach for developing percentage body fat ranges. The approach taken was to link healthy body mass index (BMI; in kg/m(2)) guidelines established by the National Institutes of Health and the World Health Organization with predicted percentage body fat. DESIGN: Body fat was measured in subjects from 3 ethnic groups (white, African American, and Asian) who were screened and evaluated at 3 universities [Cambridge (United Kingdom), Columbia (United States), and Jikei (Japan)] with use of reference body-composition methods [4-compartment model (4C) at 2 laboratories and dual-energy X-ray absorptiometry (DXA) at all 3 laboratories]. Percentage body fat prediction equations were developed based on BMI and other independent variables. RESULTS: A convenient sample of 1626 adults with BMIs < or =35 was evaluated. Independent percentage body fat predictor variables in multiple regression models included 1/BMI, sex, age, and ethnic group (R: values from 0.74 to 0.92 and SEEs from 2.8 to 5.4% fat). The prediction formulas were then used to prepare provisional healthy percentage body fat ranges based on published BMI limits for underweight (<18.5), overweight (> or =25), and obesity (> or =30). CONCLUSION: This proposed approach and initial findings provide the groundwork and stimulus for establishing international healthy body fat ranges.

Absorptiometry, Photon↗
PubMed2000

Molecular cloning and characterization of SRAM, a novel insect rel/ankyrin-family protein present in nuclei.

Previously, we purified a 59-kDa protein that binds to the kappaB motif of the Sarcophaga lectin gene. Here we report its cDNA cloning and some of its characteristics as a novel member of the Rel/Ankyrin-family. This protein, named SRAM, contained a Rel homology domain, a nuclear localization signal and 4 ankyrin repeats, but lacked the Ser-rich domain and PEST sequence that Relish contained. We found that SRAM was localized in the nuclei of NIH-Sape-4 cells, which are an embryonic cell line of Sarcophaga. The Sarcophaga lectin gene promoter containing tandem repeats of the kappaB motifs was activated in NIH-Sape-4 cells. In Drosophila mbn-2 cells, Dif alone activated this reporter gene and a cooperative effect was detected when SRAM and Dif were co-transfected, although SRAM alone did not activate it. This is the first report of a Rel/Ankyrin molecule that exists in the nuclei.

Amino Acid Sequence↗
PubMed2000

High hurdle of clinical trials to demonstrate efficacy of anticataractogenic drugs.

Recently, the rapid progression of cataract surgical technique has led cataract patients in industrialized countries to ignore the possibilities of drug therapy. Globally, however, it will be impossible in the near future to treat cataract by surgery alone, mainly due to medicoeconomic reasons. Preventative measures must be sought. As one of the these measures, the development of anticataractogenic drugs has reemerged as a focus in the lens research field. Although clinical trials of newly developed drugs are absolutely necessary before they enter the market, they have been considered to be a rather easy task. However, in order to gain accurate and reproducible data from trials, the trial program must be carefully prepared. The numbers of participants to the trial, the selection criteria of the subjects, the objective judgment of cataractous changes, follow-up period, a high technical level for cataract documentation and image analysis are proposed. Although there still remain some difficulties concerning the methods for objective judgment, a scientifically acceptable examination must be conducted.

Animals↗
PubMed2000

Thrombin stimulates pertussis toxin-sensitive and -insensitive GTPase activities and ADP-ribosylation of G(i) in human neuroblastoma SH-EP.

Kinetic interaction between thrombin receptor and G proteins was investigated in human epithelial neuroblastoma cell line, SH-EP. In these cells, both alpha-thrombin and SFLLRNP (one-letter amino-acid code) stimulated GTPase activity and enhanced cholera toxin-catalyzed ADP-ribosylation of G(i2) in a concentration-dependent manner. Basal GTPase activity was attenuated by pertussis toxin treatment by 35%, however, agonist stimulation was preserved significantly. These results together indicated that thrombin receptor simultaneously activates G(i2) and PTX-insensitive G protein(s).

Adenosine Diphosphate Ribose↗
PubMed2000

Eosinophil-adhesion-inducing activity produced by antigen-stimulated mononuclear cells involves GM-CSF.

BACKGROUND: The initial step of eosinophil accumulation in allergic inflammation is adhesion of circulating eosinophils to vascular endothelial cells (EC). There is evidence that the adhesive property of circulating eosinophils is upregulated following antigen exposure. Although the exact mechanism remains to be established, cytokine(s) produced by antigen-stimulated mononuclear cells is (are) likely key factor(s). OBJECTIVE: The objective of this study was to examine the factor(s) responsible for eosinophil adhesion and migration induced by the antigen-stimulated mononuclear cells obtained from atopic asthmatics. METHODS: Peripheral blood mononuclear cells (PBMC) isolated from house-dust-mite-sensitive bronchial asthmatics were cultured for 96 h in the presence or absence of 1 microg/ml Dermatophagoides farinae (Df) antigen. Eosinophils were isolated from peripheral blood of healthy subjects. Eosinophil-adhesion-inducing activity in the culture supernatants of PBMC was examined by the ability to modify the adhesion of eosinophils to human pulmonary microvascular endothelial cells (HPMEC) in the presence or absence of anti-cytokine/chemokine antibodies. Eosinophil migration induced by the supernatants was also examined. RESULTS: Eosinophil adhesion to HPMEC was significantly augmented by the supernatants of Df-stimulated PBMC, which was significantly inhibited by anti-GM-CSF, but not by anti-IL-5, anti-RANTES, or isotype-matched controls. On the other hand, eosinophil migration induced by the supernatants was inhibited by anti-GM-CSF and partly by anti-RANTES. CONCLUSION: Both eosinophil adhesion and migration induced by the antigen-stimulated PBMC involve GM-CSF. In contrast, RANTES is involved only in the eosinophil migration. These molecules may participate in the development of eosinophil accumulation at the allergic inflammation sites.

Antigens↗