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Biomedical subjects

H Ochi

Publications and source records attributed to H Ochi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Mesenteric desmoid with uptake on gallium-67 citrate scintigraphy.

A 72-year-old man was hospitalized for further evaluation of a space-occupying lesion in the abdomen. Magnetic resonance imaging revealed a tumor 40 mm in diameter in the abdomen. Anterior Ga-67 citrate scintigraphy revealed a region of accumulation of radioactivity in the abdomen corresponding to the tumor. Mesenteric desmoid was diagnosed on the basis of histological findings for the excised tumor. These finding suggested that mesenteric desmoid may be one of the tumors which show high uptake of Ga-67.

Abdominal Pain↗
PubMed2001

A case of glucagonoma with high uptake on F-18 fluorodeoxyglucose positron emission tomography.

Glucagonomas are relatively rare, and can be difficult to differentiate from other pancreatic tumors. A 62-year-old woman who had suffered from diabetes mellitus was hospitalized for further evaluation of a space-occupying lesion in the head of the pancreas and tumors in the liver. F-18 fluorodeoxyglucose positron emission tomography revealed accumulation of isotope corresponding to a tumor of the pancreas with a standardized uptake value of 4.3, and tumors in the liver with standardized uptake values of 2.4 and 2.8. The serum glucagon level was high (1,170 pg/ml) and the secretin tolerance test was negative. She was diagnosed with glucagonoma with a high serum glucagon level and clinical findings. It is suggested that glucagonoma may be one of the tumors which show high uptake of F-18 fluorodeoxyglucose.

Biological Transport↗
PubMed2001

Accessory spleen in the pelvis diagnosed by Tc-99m phytate scintigraphy.

We report a 58-year-old woman with an accessory spleen in the left side of the pelvis. She visited our outpatient clinic complaining of lower abdominal discomfort. Abdominal ultrasonography revealed a tumor 4 cm in diameter in the left side of the pelvis. Color Doppler ultrasonography demonstrated plentiful pulsating blood flow. Magnetic resonance angiography revealed that the blood supply for the tumor was from a branch of the splenic artery. Scintigraphy with Tc-99m phytate revealed accumulation of radioactivity concordant with a mass in the left side of the pelvis, and the spleen was normally visualized. These findings suggested that this tumor was an accessory spleen, and the patient underwent no further invasive procedures.

Female↗
PubMed2001

Physiological FDG uptake in the palatine tonsils.

In clinical F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) studies of the head and neck region, remarkable symmetric tonsillar FDG uptake is sometimes observed. We determined the incidence and degree of tonsillar FDG uptake and investigated the significance of tonsillar FDG uptake. Between June 1998 and August 1998, we obtained informed consent from 17 patients who were scheduled to undergo a FDG-PET study for their own disease (11 men and 6 women; aged 22 to 77 yr) and who did not have head and neck disease to perform FDG-PET scanning of the head and neck region in addition to their target organs. The incidence and degree of tonsillar FDG uptake were determined. Remarkable tonsillar FDG uptake was found in 9 patients. The SUVs of these FDG uptakes ranged from 2.48 to 6.75, with a mean of 4.29 +/- 1.20 (SD). Tonsillar FDG uptakes in the remaining 8 patients were not remarkable, and their SUVs ranged from 1.93 to 3.31, with a mean of 2.46 +/- 0.45. Head and neck disease does not appear to have been responsible for the increase in tonsillar FDG uptake. Differences among tonsillar FDG uptake in these 17 patients without head and neck disease appear to reflect differences in activity of "physiological" inflammation of the palatine tonsils.

Adult↗
PubMed2001

Dose-dependent conjugation of sulfobromophthalein and hepatic transit time in bile fistula rats: role of the microtubule-dependent vesicle pathway.

Sulfobromophthalein (BSP) is selectively taken up by the liver and secreted into the bile as unconjugated and conjugated forms. Our previous study demonstrated that unconjugated BSP, but not conjugated BSP, caused the dissociation of biliary lipid secretion from that of bile acids, suggesting that the hepatic BSP conjugation rate partly regulated biliary lipid secretion. To evaluate the mechanisms through which biliary lipid secretion is regulated by exogenous organic anions, we intravenously administered BSP to male Sprague-Dawley rats at various doses either continuously or as a bolus. Then the relationship of the dose of BSP to its conjugation rate, hepatic transit time, and biliary lipid secretion was determined. BSP decreased biliary secretion of cholesterol and phospholipids in a dose-dependent manner without affecting bile acid secretion. In contrast, the proportion of conjugated BSP in bile was associated with the dose. Although the serum clearance of BSP after bolus infusion was constant regardless of the dose administered (50 or 200 nmol/100 g), BSP secretion was delayed with increasing doses: unconjugated BSP was secreted predominantly in the early phase (0-15 min after bolus injection), and conjugated BSP was the predominant form in the late phase (15-30 min). Pretreatment with colchicine reduced the conjugation rate and hepatic transit time of BSP, suggesting that the microtubule-dependent vesicle pathway plays a role in biliary excretion and conjugation of BSP. We conclude that biliary lipid secretion is influenced by organic anions with an affinity for bile acids such as BSP and that this effect is dependent upon the hepatic metabolic rate, i.e., conjugation rate. The hepatic transit time also plays a key role in this process by influencing metabolism.

Animals↗
PubMed2001

Modifying hepatic phospholipid synthesis associates with biliary phospholipid secretion rate in a transporter-independent manner in rats: relation to canalicular membrane fluidity.

Biliary phospholipid secretion is mediated by a multidrug resistance gene product, and its molecular subselection occurs at the site of secretion to modulates bile metastability. The aim of this study was to determine the effect of modifying hepatic phospholipid synthesis on canalicular phospholipid transporter expression and membrane fluidity. Bile-duct cannulation was performed in male Sprague-Dawley rats pretreated with or without intravenous infusion of dimethylethanolamine, an intermediate phospholipid metabolite along the pathway of phosphatidylcholine synthesis of phosphatidylethanolamine N-methylation (0.01 mg/min/100 g body wt) for 15 hr, followed by sodium taurocholate infusion (50 nmol/min/100 g body wt) with or without sulfobromophthalein (50 nmol/min/100 g body wt). Dimethylethanolamine enhanced biliary phospholipid secretion in association with a decrease in biliary phospholipid hydrophobicity. Dimethylethanolamine also increased canalicular membrane fluidity defined by 1,6-diphenyl-1,3,5-hexatriene fluorescence depolarization, whereas the expression of multidrug resistance gene product and multidrug resistance associated protein was unchanged. In contrast, a disproportionate reduction of biliary phospholipid secretion caused by sulfobromophthalein (uncoupling) was enhanced by under the treatment with dimethylethanolamine. In conclusion, the increase in biliary phospholipid secretion and canalicular membrane fluidity without a drastic change of its canalicular transporter by dimethylethanolamine suggests that such a canalicular membrane fluidity facilitates the transporter activity and/or phospholipid molecular movement from the canalicular outer membrane into the bile. A more drastic reduction in phospholipid secretion under sulfobromophthalein-caused uncoupling indicates the possibility of a preferential distribution of relatively hydrophilic phosphatidylcholine molecules to bile salt micelles since sulfobromophthalein is known to reduce the micellar capacity to extract membrane lipids for biliary secretion.

Animals↗
PubMed2001

Phospholipid alterations in hepatocyte membranes and transporter protein changes in cholestatic rat model.

Biliary components are transported by hepatic adenosine triphosphate-binding cassette (ABC) transporters that are located in canalicular membranes. Physiological transporter function is related to membrane fluidity, which is modulated by the phospholipid composition of the lipid bilayer. We hypothesized that cholestasis may alter transporter function by modifying phospholipid species to protect the cell from cholestatic damage. Therefore, we examined the expression of ABC transport proteins and their mRNA levels in canalicular membrane vesicles isolated from rat liver 6 hr or three days after bile duct ligation. Membrane lipid composition and membrane fluidity of both sinusoidal and canalicular membrane vesicles were also examined. By 6 hr after bile duct ligation, we found a clear increase of mdr2 and bsep mRNA. These changes were associated with an increase of mdr-Pgp and with a clear decrease of mrp2 protein, and small decrease of bsep protein. In addition, mdrlb mRNA showed a strong increase by three days after bile duct ligation. Canalicular membrane fluidity decreased in a marked time-dependent manner, whereas sinusoidal membranes showed biphasic changes: increased fluidity at 6 hr and a decrease at three days. These changes were closely related to the changes of membrane lipid constitution; the saturated/unsaturated fatty acid ratio increased for phosphatidylcholine in canalicular membrane and the reverse occurred in sinusoidal membrane, and those for sphingomyelin showed the opposite pattern. We conclude that cholestasis causes modulation of ABC transporters as well as that of the lipid constitution in lipid bilayer. These may confer cytoprotective resistance to hepatocytes against cholestatic stress.

ATP-Binding Cassette Transporters↗
PubMed2001

Differences between T-cell reactivities to major myelin protein-derived peptides in opticospinal and conventional forms of multiple sclerosis and healthy controls.

In Japanese, susceptibility to the conventional form of multiple sclerosis (C-MS) is associated with the HLA-DRB1*1501-DRB5*0101 haplotype while susceptibility to the opticospinal form of MS (OS-MS) is associated with HLA-DPA1*0202-DPB1*0501. To clarify the characteristics of T cells autoreactive to myelin proteins in each MS subtype, we established T-cell lines reactive to such myelin antigens as myelin basic protein (MBP), proteolipid protein (PLP) and myelin oligodendrocyte glycoprotein (MOG) from 5 of 10 OS-MS patients, 6 of 11 C-MS patients and 7 of 13 healthy controls (HCs), and T-cell epitopes and their restriction molecules were determined. We found that (a) intermolecular epitope spreading was found to be significantly more frequent in MS patients than in HCs (P=0.0128), (b) intramolecular epitope spreading also tended to occur more frequently in MS patients than in HCs (P=0.0584), (c) in OS-MS, HLA-DR-restricted and MOG-autoreactive T cells were more frequently established as compared with those reactive to MBP or PLP epitopes and (d) in C-MS, HLA-DQ-restricted and PLP-autoreactive T cells dominated those autoreactive to MBP or MOG epitopes. A DPB1*0501-restricted MBP-reactive T-cell clone from a patient with OS-MS provided evidence that the first HLA class II anchor amino acid of peptide bound to disease-susceptible DP5 molecule was distinct from that for the DR2 molecule. Taken together, these differences in specificities of myelin-autoreactive T cells between C-MS and OS-MS as well as the difference in the anchor motif of the binding peptides between each MS subtype-susceptible HLA class II molecule may contribute to the development of distinct clinical phenotypes.

Adult↗
PubMed2001

Effect of insulin, proinsulin, and amylin on renin release from perfused rat kidney.

To evaluate the possible role of insulin, proinsulin, and amylin in the renin-angiotensin system, the direct effect of these peptides on renin release was examined using perfused kidney of rats. Renin release was significantly increased from a basal value of 6.1 +/- 1.8 to a peak value of 10.1 +/- 2.3 ng angiotensin I (Ang I)/mL/h by 0.5 nmol insulin, from 6.0 +/- 1.7 to 16.7 +/- 4.5 ng Ang I/mL/h by 1 nmol insulin, and from 6.1 +/- 1.8 to 18.0 +/- 5.5 ng Ang I/mL/h by 8 nmol insulin. Renin release was not significantly changed by perfusion of 0.05 nmol proinsulin or amylin but significantly increased from a basal value of 6.1 +/- 1.7 to a peak value of 8.1 +/- 3.6 ng Ang I/mL/h by 1 nmol proinsulin, from 5.6 +/- 1.7 to 12.1 +/- 3.8 ng Ang I/mL/h by 8 nmol proinsulin, from 5.7 +/- 1.9 to 8.2 +/- 3.5 ng Ang I/mL/h by 1 nmol amylin, and from 5.2 +/- 2.0 to 12.4 +/- 3.3 ng Ang I/mL/h by 8 nmol amylin. The concentration of cyclic adenosine monophosphate in the effluent was significantly increased from a basal value of 5.1 +/- 1.6 to a peak value of 10.6 +/- 2.5 mmol/min by 8 nmol amylin but not altered by perfusion of insulin or proinsulin. The addition of 0.05 nmol proinsulin and 0.05 nmol of amylin on 0.5 nmol insulin significantly enhanced renin release. These results indicate that insulin may play an important physiologic role in the renin-angiotensin system and suggest that proinsulin and amylin may be involved in the genesis and development of hypertension through enhancement of insulin-stimulated renin release.

Amyloid↗
PubMed2001

Usefulness of positron emission tomography with fluorine-18-fluorodeoxyglucose for predicting outcome in patients with hepatocellular carcinoma.

OBJECTIVES: The present study was designed to assess the usefulness of positron emission tomography with fluorine-18-fluorodeoxyglucose (FDG-PET) for predicting outcome in patients with hepatocellular carcinoma. METHODS: FDG-PET was performed in 48 patients with hepatocellular carcinoma. For quantitative evaluation, a region of interest (ROI) was placed over the area of maximum activity within the lesion. A background ROI was then placed over the nontumor region of the liver. The average activity within each ROI was subsequently corrected for radioactive decay, and the standardized uptake value (SUV) was calculated by dividing the tissue activity by the injected dose of radioactivity per unit body weight. SUV ratio was expressed as the tumor-to-nontumor ratio of the SUV. RESULTS: The tumor-volume doubling time, as index of the growth rate of hepatocellular carcinoma, correlated significantly with SUV ratio but did not correlate with SUV. On the basis of the SUV ratio, the patients were divided into two groups of similar size: group A, SUV ratio of < or = 1.5; and group B, SUV ratio > 1.5. The cumulative survival rate was significantly lower in group B than in group A. On the basis of the SUV, the patients were divided into two groups of roughly equal size: group C, < or = SUV 2.6; and group D, > SUV 2.6. The cumulative survival rate was similar in these groups. On regression analysis with the Cox proportional hazards model, the SUV ratio and tumor number were significantly related to survival. CONCLUSIONS: These results suggest that FDG-PET is useful not only for the evaluation of the malignancy of hepatocellular carcinoma but also for the prediction of outcome in patients with hepatocellular carcinoma.

Adult↗
PubMed2001

Lysophosphatidylcholine inhibits T cell-specific CXC chemokines IP-10, MIG, and I-TAC expression induced by IFN-gamma in human endothelial cells.

Hypercholesterolemia is reported to be associated with a T helper (Th) 1 to Th2 switch in apoE-deficient mice. To explore the underlying mechanisms of such immune modulation, we investigated if lysophosphatidylcholine (Lyso-PC), enriched in oxidized LDL, affects cytokine-induced expression of Th1 cell-specific CXC chemokines, IFN-inducible protein of 10 kDa (IP-10), monokine induced by IFN-gamma (Mig), and IFN-inducible T cell a chemoattractant (1-TAC) in cultured endothelial cells. Lyso-PC inhibited IFN-gamma or IFN-gamma plus TNF-alpha-induced IP-10, Mig, and I-TAC mRNA expression but not that of the IRF-1 or IRF-1 dependent molecule, GBP. It also inhibited IP-10 protein secretion in conditioned media induced by IFN-gamma or IFN-y plus TNF-alpha Western analysis demonstrated that Lyso-PC inhibited IFN-gamma-induced STAT-1alpha protein expression, but not that of IRF-1. These results suggest that Lyso-PC selectively inhibits IP-10, Mig, and I-TAC expression through IRF-1-independent mechanisms. This inhibitory effect of Lyso-PC may be involved in the immune modulation by hypercholesterolemia.

Chemokine CXCL10↗
PubMed2001

Human Mast cell progenitors can be infected by macrophagetropic human immunodeficiency virus type 1 and retain virus with maturation in vitro.

Mast cells are critical components of innate and adaptive immunity that differentiate in tissues in situ from circulating committed progenitor cells. We now demonstrate that human cord blood-derived mast cell progenitors are susceptible to infection with macrophagetropic (M-tropic) and dualtropic human immunodeficiency virus type 1 (HIV-1) isolates but not with T-cell-tropic (T-tropic) strains. Mast cell progenitors (c-kit(+) CD13(+) cells with chloroacetate esterase activity) were purified from 4-week-old cultures of cord blood mononuclear cells maintained in stem cell factor, interleukin-6 (IL-6), and IL-10 using a CD14 depletion column. These progenitors expressed CCR3, CCR5, and CXCR4, as well as low levels of CD4. When infected in vitro with viruses pseudotyped with different HIV and simian immunodeficiency virus envelope glycoproteins, only M-tropic and dualtropic, but not T-tropic, viruses were able to enter mast cell progenitors. Both the CCR5-specific monoclonal antibody 2D7 and TAK-779, a nonpeptide inhibitor of CCR5-mediated viral entry, blocked HIV-1 strain ADA infection by >80%. Cultures infected with replication-competent virus produced progressively increasing amounts of virus for 21 days as indicated by p24 antigen detection. Mast cell progenitors that were exposed to an M-tropic, green fluorescent protein-expressing HIV-1 strain exhibited fluorescence indicative of viral entry and replication on a single-cell level and retained virus production during differentiation. The trafficking of mast cell progenitors to multiple tissues, combined with the long life span of mature mast cells, suggests that they could provide a widespread and persistent HIV reservoir in AIDS.

CD4 Antigens↗
PubMed2001

Juvenile muscular atrophy of the distal upper limb (Hirayama disease) associated with atopy.

Juvenile muscular atrophy of the distal upper limb (Hirayama disease) is a rare disease predominantly affecting the anterior horn cells of the cervical spinal cord in young men. Although the disease is considered to be a type of cervical myelopathy, the mechanism remains unknown. An immunological study of five consecutive patients with this disorder who were examined in the neurology clinic at Kyushu University Hospital during the past 2 years were performed. All developed distal muscular atrophy and weakness of one or both upper limbs in the second decade, and showed forward displacement of the dural sac and passive dilatation of the posterior venus plexus at the lower cervical portion on MRI during neck flexion. Four of the five patients had one or more coexistent airway allergies, such as allergic rhinitis, pollinosis, and asthma, and all five patients had a family history of atopic or allergic disorders in close relatives. Four of the five patients had mild eosinophilia. All five patients commonly had IgE specific to two mite antigens, Dermatophagoides pteronyssinus and Dermatophagoides farinae, whereas three of them also showed a raised total serum IgE concentration. The frequency of mite antigen specific IgE was significantly higher in the present patients with Hirayama disease than in 82 healthy controls (26/82, p<0.005). These findings suggest that atopy may be one of the contributing factors for Hirayama disease.

Adolescent↗
PubMed2001

Effects of smoking on myocardial injury in patients with conservatively treated acute myocardial infarction: a study with resting 123I-15-iodophenyl 3-methyl pentadecanoic acid/201Tl myocardial single photon emission computed tomography.

Many reports have demonstrated that smokers who have suffered an acute myocardial infarction (AMI) have a better prognosis than nonsmokers. The present study investigated the effects of current smoking on myocardial injury with resting 123I-15-iodophenyl 3-methyl pentadecanoic acid (BMIPP)/201Tl myocardial single photon emission computed tomography in 103 patients with conservatively treated AMI. The left ventricular myocardium was divided into 9 segments and BMIPP and 201Tl defects were scored using a 5-point grading system (0 = normal and 4 = no uptake). The sum of the defect scores was defined as the total defect score. There was no significant difference in either the baseline severity of the coronary artery disease or the total defect scores for BMIPP and 201Tl between the current smoker and nonsmoker groups. The difference between the total defect scores for BMIPP and 201Tl tended to be larger in the current smoker group than in the nonsmoker group (2.0 +/- 1.9 vs 1.3 +/- 1.6, p = 0.056). Forty-one (53%) of 77 patients in the current smoker group exhibited a BMIPP/201Tl mismatch, whereas only 8 (31%) of 26 patients in the nonsmoker group did (p = 0.047). In conclusion, current smokers had more likelihood of salvageable myocardium in areas at risk, as demonstrated by BMIPP/201Tl mismatch, in AMI than nonsmokers.

Adult↗