Linearity and bisimulation

Exploiting linear type structure, we introduce a new theory of weak bisimilarity for the π-calculus in which we abstract away not only τ-actions but also non-τ actions which do not affect well-typed observers. This gives a congruence far larger than the standard bisimilarity while retaining semantic soundness. The framework is smoothly extendible to other settings involving nondeterminism and state. As an application we develop a behavioural theory of secrecy in the π-calculus which ensures secure information flow for a strictly greater set of processes than the type-based approach, while still offering compositional verification techniques.     

A case suspected of early active pulmonary tuberculosis detected by CT with the onset of episcleritis

A 56-year-old female with the chief complaint of conjunctival injection was referred to our hospital after treatments with oral and topical corticosteroid under the diagnosis of episcleritis without any therapeutic efficacy. Possible causes of the episcleritis such as collagen vascular disease were not found, but a chest CT revealed centrilobular nodules, branching linear lesions and bronchial wall thickening which were not detected in a plain X-ray picture. We suspected pulmonary tuberculosis and tuberculous episcleritis based on these CT findings, strongly positive tuberculine skin test result and a history of contact with a smear positive tuberculosis patient. The pulmonary lesion disappeared and the episcleritis healed after the treatment with systemic antituberculous agents.     

A comparative study of transcranial Doppler sonography and near-infrared spectroscopy for the assessment of cerebrovascular CO2 reactivity

Oleanolic acid (1) was identified as an anti-HIV principle from several plants, including Rosa woodsii (leaves), Prosopis glandulosa (leaves and twigs), Phoradendron juniperinum (whole plant), Syzygium claviflorum (leaves), Hyptis capitata (whole plant), and Ternstromia gymnanthera (aerial part). It inhibited HIV-1 replication in acutely infected H9 cells with an EC50 value of 1.7 microg/mL, and inhibited H9 cell growth with an IC50 value of 21.8 microg/mL [therapeutic index (T. I.) 12.8]. Pomolic acid, isolated from R. woodsii and H. capitata, was also identified as an anti-HIV agent (EC50 1.4 microg/mL, T. I. 16.6). Although ursolic acid did show anti-HIV activity (EC50 2.0 microg/mL), it was slightly toxic (IC50 6.5 microg/mL, T. I. 3.3). A new triterpene (11) was also isolated from the CHCl3-soluble fraction of R. woodsii, though it showed no anti-HIV activity. The structure of 11 was determined to be 1beta-hydroxy-2-oxopomolic acid by spectral examination. Based on these results, we examined the anti-HIV activity of oleanolic acid- or pomolic acid-related triterpenes isolated from several plants. In addition, we previously demonstrated that derivatives of betulinic acid, isolated from the leaves of S. claviflorum as an anti-HIV principle, exhibited extremely potent anti-HIV activity. Accordingly, we prepared derivatives of oleanolic acid and evaluated their anti-HIV activity. Among the oleanolic acid derivatives, 18 demonstrated most potent anti-HIV activity, with an EC50 value of 0. 0005 microg/mL and a T. I. value of 22 400.     

Studies on bacillary dysentery cases of overseas travellers--during 1979 to 1995

A total of 36,780,440 overseas travellers during 1979-1995 (17 years) were quarantined at Osaka and Kansai Airport Quarantine Station, 84,777 travellers reported themselves suffer from diarrhoea. Stools from 29,587 persons were bacteriologically examined. Various enteropathogenic bacteria were isolated from 9,766 (33.0%) patients of the stools examined. Isolated species were as follows: Plesiomonas shigelloides (3,234 cases); Salmonella spp. (2,236 cases); enterotoxgenic Escherichia coli (1,621 cases); Vibrio parahaemolyticus (1,959 cases); and Shigella spp. (1,242 cases). 1,278 different Shigella strains were isolated from 1,242 cases who were thus diagnosed as bacillary dysentery patients. The suspected regions or countries for infection of these cases were analysed. The serovars and antibiotic-sensitivities of the isolated strains were examined. Colicine typing of S. sonnei strains were also done. The results can be summarized as follows. 1) The most cases (53.4%) were infected in India. 2) The percentage distribution of sub-species of the strains was as follows; S. sonnei (57.8%), S flexneri (29.8%), S. boydii (8.4%), and S. dysenteriae (4.0%), respectively. 3) The major colicine type of S. sonnei strains were type 6 and 0. 4) The percentage of Antibiotic-resistant strains of each sub-species was S. dysenteriae (92.2%), S. sonnei (89.4%), S. flexneri (87.1%), and S. boydii (84.9%), respectively. The percentage of Antibiotic-resistant strains of S. flexneri were increased annually.     

Studies of aqueous resins

Summary Polyesters were modified by introducing small amounts of sodium sulfonate groups as hydrophilic groups in their backbones. Stable aqueous dispersions of the polyesters could be obtained by using 2-butoxyethanol (BEA) as a cosolvent. To clarify the role of the cosolvent, they were separated into two layers, polymer and supernatant layers, byultracentrifugation. Cosolvent contents were found to be different in the former and latter layers; i.e., the contents of BEA in the former layer are low in the case of crystalline polyesters and high in the case of noncrystalline ones. Characteristics of the dispersions such as viscosity are strongly affected by the content of the cosolvent.     

Concentration of cadmium in rice and urinary indicators of renal dysfunction

OBJECTIVES: (1) To examine the relation between concentrations of cadmium (Cd) in rice and urinary concentrations of indicators of renal dysfunction and the prevalence of abnormalities in urine in areas polluted by Cd. (2) To establish the maximum allowable concentration of Cd in rice from these findings. METHODS: The target population consisted of 1703 inhabitants (832 men and 871 women) aged over 50 years who consumed home grown rice and had lived in the same hamlet in areas polluted by Cd in the Kakehashi River basin in Ishikawa Prefecture, Japan for at least 30 years. The correlation coefficients between concentrations of Cd in rice and several urinary substances, the prevalence of abnormalities in urine and sex in hamlets polluted by Cd were calculated. Finally, regression analysis was performed for significant indicators to calculate the maximum allowable concentration of Cd in rice based on values in a control group. CONCLUSIONS: Significant correlations between concentration of Cd in rice and concentrations of urinary beta 2-microglobulin, metallothionein, glucose, and aminonitrogen were established. Similarly, there were significant correlations between concentration of Cd in rice and the prevalence of beta 2-microglobulinuria, metallothioneinuria, glucosuria, proteinuria, proteinuria with glucosuria, and aminonitrogenuria. The highest maximum allowable concentration of Cd in rice calculated for these indicators was 0.34 ppm/l and 0.29 ppm/g creatinine. Both values are lower than 0.4 ppm, the tentative limit prescribed by the Japanese government.     

FDG uptake, GLUT-1 glucose transporter and cellularity in human pancreatic tumors

We previously reported that grading of GLUT-1 glucose transporter expression was related closely to FDG accumulation in FDG PET in human cancers. But in this strong GLUT-1 expression group, there was an enormous range of standardized uptake values (SUVs) within them. METHODS: To evaluate other factors determining the FDG PET uptake, FDG PET was performed in 36 preoperative patients (mean age 62.0 yr) suspected of having pancreatic tumors, including 33 malignant and 3 benign neoplastic tumors. FDG uptake at 50 min after injection of 185 MBq 18F-FDG with > 5 hr fasting condition was semiquantitatively analyzed as SUVs. The GLUT-1 expression was studied by immunohistochemistry of paraffin sections from these tumors after the operation using the antiGLUT-1 antibody. The number of tumor cells within a 5- x 5-mm square was counted manually using x200 magnification photographs and was graded immunohistochemically as strong, weak or negative. RESULTS: In all 36 cases there were 3 cases of GLUT-1 negative, 8 of GLUT-1 weak positive and 25 of GLUT-1 strong positive. In all cases, the total number of tumor cells had no significant value for SUVs. Among 33 GLUT-1 positive cases, the number of GLUT-1 positive tumor cells correlated significantly with SUVs (p < 0.01). Only in 25 strong grade cases, the number of GLUT-1 strong positive tumor cells had a more significant value for SUVs (p < 0.005). Computational multivariate analysis using multiple regression for SUVs was performed evaluating the five variables as follows: tumor size, GLUT-1 immunohistochemical grading, number of total tumor cells, number of total GLUT-1 positive tumor cells and number of GLUT-1 strong positive cells. This analysis revealed that only the variable, the number of GLUT-1 strong positive cells, had a significant regression coefficient for SUVs (standard regression coefficient = 0.855, p < 0.0001). CONCLUSION: These data indicate that GLUT-1 expression plays an essential role in higher FDG accumulation in pancreatic tumor FDG PET, and the cellularity has a significant influence on SUVs only in the condition of GLUT-1 strong positive expression.     

Regulation of rat hepatic 3beta-hydroxysterol delta7-reductase: substrate specificity, competitive and non-competitive inhibition, and phosphorylation/dephosphorylation

The mechanism for the catalytic reduction of the double bond at C-7, 8 in 7-dehydrocholesterol by 3beta-hydroxysterol Delta7-reductase was investigated by testing structurally related sterols as substrates and potential inhibitors. The hepatic smooth endoplasmic reticulum was identified as the site of enzyme activity. All putative substrates contained 27 carbons, but differed from 7-dehydrocholesterol by the addition of either an ethyl substituent at C-24 (7-dehydrositosterol), a double bond at C-22 with a methyl substituent at C-24 (ergosterol), epimerization of the hydroxyl from the 3beta- to 3alpha-configuration (7-dehydroepicholesterol), or a saturated double bond at C-5,6 (lathosterol). Two non-steroidal compounds that inhibit 3beta-hydroxysterol Delta7-reductase in vivo (AY 9944 and BM 15.766) were also tested. Ergosterol, 7-dehydrositosterol, and 7-dehydroepicholesterol were reduced at C-7, 8 to form brassicasterol, sitosterol, and epicholesterol, respectively, but 75% less efficiently than 7-dehydrocholesterol. Increasing concentrations of these sterols competitively inhibited 3beta-hydroxysterol Delta7-reductase activity. The double bond at C-7,8 in lathosterol was not reduced. AY 9944 and BM 15.766 inhibited 3beta-hydroxysterol Delta7-reductase activity non-competitively. 3beta-Hydroxysterol-Delta7-reductase activity declined after microsomes were exposed to alkaline phosphatase, and enzyme activity was increased by phosphorylation with Mg2+, and ATP. These results demonstrate that the reduction of the double bond at C-7,8 requires binding of the enzyme protein with the B-ring of the sterol substrate that contains a double bond at C-5,6. The reaction is hindered by substituents located on the apolar side-chain and epimerization of the hydroxyl group in ring A to a 3alpha-configuration. 3beta-Hydroxysterol Delta7-reductase exists in two forms: an active phosphorylated form and an inactive dephosphorylated form.