To determine the localization of increased vascular resistance in cirrhotic liver, blood pressures were measured by a direct cannulation method at several key points in the hepatic vascular pathway in normal and cirrhotic rats. Cirrhosis was produced by feeding a choline-deficient diet. Blood pressures in normal rats were 110 mm H2O in the portal vein, 68 mm H2O in the terminal portal venule, 28 mm H2O in the terminal hepatic venule and 20 mm H2O in the inferior vena cava. In cirrhotic rats, blood pressures in the portal vein and the terminal portal venule were 173 and 100 mm H2O, respectively, while those in the terminal hepatic venule and the inferior vena cava were elevated only slightly above normal. These hemodynamic data suggest that an increase in vascular resistance in cirrhotic liver is present in the intrahepatic portal vein and sinusoids, but not in intrahepatic hepatic vein. In cirrhotic liver, stenosis and distortion were found in peripheral branches of the portal vein, and sinusoidal stenoses and a decrease in sinusoidal space were recognized. Accordingly, it is suggested that the increase in vascular resistance in the intrahepatic portal vein and sinusoids correlate with these structural changes. Although severe stenoses and distortion were found in hepatic vein branches, it was thought that they do not contribute to portal hypertension because of lack of increase in vascular resistance in the intrahepatic hepatic vein.

Animals↗

PubMedDate not supplied

Prediction of operator-binding protein by discriminant analysis.

A number of operator-binding proteins contain similar sequence features to Cro and cI repressors of bacteriophage and CAP protein of Escherichia coli, such as conserved amino acids at constant positions. However, these sequence patterns also occur in proteins that are not operator-binding. We use sequence analogy information in conjunction with a pattern recognition algorithm. The functional and structural properties, e.g., distributions of hydrophobicity, hydrophilicity, charged amino acids, electrostatic free energy, and helical structures of protein are also considered. Within the framework of discriminant analysis, we calculate the above variables and search for a better combination of variables. To assess the discriminatory power of these variables, we allocated additional sequences and predict DNA-binding regions of regulatory proteins not included in the training set.

Algorithms↗

PubMedDate not supplied

Magnifying prismatic lenses for vitrectomy.

PURPOSE: Viewing the fundus at higher magnification during vitrectomy makes surgical procedures much safer; however, the scope of magnification of the peripheral fundus has been limited. For better visualization of the periphery of the fundus, we have developed two new contact lenses called magnifying prismatic lenses. METHODS: The magnifying 15 degrees and 30 degrees prismatic lenses are made of a glass with a high index of refraction (n = 1.883). The lenses have a convex upper surface to provide a magnified view of the peripheral fundus. RESULTS: These magnifying 15 degrees and 30 degrees prismatic lenses provide an approximately 2x magnified view of the peripheral fundus. They also provide a more extensive view of the peripheral fundus than a regular (plano-concave) prismatic lens when the eye is tilted. CONCLUSION: The magnifying prismatic lenses are useful for viewing into the peripheral fundus with higher magnification.

Fundus Oculi↗

PubMedDate not supplied

A new coastal marine ecosystem model study coupled with hydrodynamics and tidal flat ecosystem effect.

A new coastal marine ecosystem model was developed, which was composed of pelagic and benthic ecosystems, and was applied to Mikawa Bay, Japan. This model deals with variations of biochemical and physical interactions among dissolved oxygen and C-N-P species (composition formed out of carbon, nitrogen and phosphorus elements) so that it resolves the flux dynamics of carbon, nitrogen, phosphorus and oxygen elements. The physical and biochemical mechanism figured in this model is constructed for the purpose of simulating the estuarine lower trophic ecosystem, in areas where the sea was too deep for light to reach the sea-bottom. As a result of coupling the benthic with pelagic system, the effect of process of sedimentation and nutrient diffusion back to the pelagic system could be indicated. In addition, by implementing the tidal flat ecosystem model's calculation result, the integrated model can include the effect of water purification in tidal flats where the light can reach the sea-bottom, and where seaweed, sea grass and benthic algae exist. In this study, the model indicates that oxygen-depleted water exists at the sea-bottom especially in summer mainly caused by an increase of oxygen consumption in the benthic system and a decrease of the vertical mixing water process. Furthermore, by comparing the case--with the tidal flat ecosystem model and the case without it, the effect of water purification of tidal flat estuaries was indicated. From the viewpoint of a short time scale, the tidal flat has the potential to restrict red tide (rapid increase of phytoplankton), and from the viewpoint of a long time scale, it restricts the sedimentation of detritus. Restricting the sedimentation prevents oxygen-depleted water occurring in the coastal marine system of Mikawa Bay.

Ecosystem↗

PubMedDate not supplied

A numerical simulation of the seasonal cycle of temperature, salinity and velocity fields in Tokyo Bay.

To understand when oxygen-depleted waters occur, how they develop and when they dissipate in inner Tokyo Bay, realistic simulations were attempted with fine spatial and temporal resolution by applying realistic time dependent external forcing. A 3D hydrodynamic model was driven by time-dependent external forcing factors/parameters such as solar radiation, air temperature, relative humidity, wind velocity, and fluvial discharge, under the open boundary conditions of 1995. A simulated time series of salinity and temperature agreed fairly well with observed data, except in summer. The model failed to reproduce the development of the surface mixed layer in summer. Several sensitivity analyses on the external forcing parameters such as wind velocity and vertical diffusivity were conducted to reproduce the mixed layer. However, changing these parameter values did not improve the model results.

Humidity↗

PubMedDate not supplied

Development of the receptor database (RDB): application to the endocrine disruptor problem.

MOTIVATION: To represent various aspects of receptors effectively, we developed the receptor database (RDB), using an object-oriented database management system ACEDB and the Internet/WWW technology. RESULTS: RDB was constructed so that the system collects data items such as attributes of proteins from distributed data sources of the Internet, and so that it provides various viewing tools effectively, depending on different types of receptor data. Such sources include standard international biological databases such as the up-to-date database of PIR, Swiss Prot, PDB, GenBank and GDB. Application to the endocrine disruptor problem is presented. AVAILABILITY: RDB is available through the Internet at http://impact.nihs.go.jp/RDB.html.

Amino Acid Sequence↗