A new liver perfusion and preservation system for transplantation Research in large animals

A kidney perfusion machine, model MOX-100 (Waters Instruments, Ltd, Rochester, MN) was modified to allow continuous perfusion of the portal vein and pulsatile perfusion of the hepatic artery of the liver. Additional apparatus consists of a cooling system, a membrane oxygenator, a filter for foreign bodies, and bubble traps. This system not only allows hypothermic perfusion preservation of the liver graft, but furthermore enables investigation of ex vivo simulation of various circulatory circumstances in which physiological perfusion of the liver is studied. We have used this system to evaluate the viability of liver allografts preserved by cold storage. The liver was placed on the perfusion system and perfused with blood with a hematocrit of approximately 20% and maintained at 37°C for 3 h. The flows of the hepatic artery and portal vein were adjusted to 0.33 mL and 0.67 mL/g of liver tissue, respectively. Parameters of viability consisted of hourly bile output, oxygen consumption, liver enzymes, electrolytes, vascular resistance, and liver histology. This method of liver assessment in large animals will allow the objective evaluation of organ viability for transplantation and thereby improve the outcome of organ transplantation. Furthermore, this pump enables investigation into the pathophysiology of liver ischemia and preservation. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

Arbitrary Choice of Basic Variables in Density Functional Theory. II. Illustrative Applications

Our recent theory (Ref. 1) enables us to choose arbitrary quantities as the basic variables of the density functional theory. In this paper we apply it to several cases. In the case where the occupation matrix of localized orbitals is chosen as a basic variable, we can obtain the single-particle equation which is equivalent to that of the LDA+U method. The theory also leads to the Hartree-Fock-Kohn-Sham equation by letting the exchange energy be a basic variable. Furthermore, if the quantity associated with the density of states near the Fermi level is chosen as a basic variable, the resulting single-particle equation includes the additional potential which could mainly modify the energy-band structures near the Fermi level.Comment: 27 page

Propagation of Ultra-High Energy Cosmic Rays above 101910^{19} eV in a Structured Extragalactic Magnetic Field and Galactic Magnetic Field

We present numerical simulations on propagation of Ultra-High Energy Cosmic Rays (UHECRs) above $10^{19}$ eV in a structured extragalactic magnetic field (EGMF) and simulate their arrival distributions at the earth. We use the IRAS PSCz catalogue in order to construct a model of the EGMF and source models of UHECRs, both of which reproduce the local structures observed around the Milky Way. We also consider modifications of UHECR arrival directions by the galactic magnetic field. We follow an inverse process of their propagation from the earth and record the trajectories. This enables us to calculate only trajectories of UHECRs arriving at the earth, which saves the CPU time. From these trajectories and our source models, we construct arrival distributions of UHECRs and calculate the harmonic amplitudes and the two point correlation functions of them. We estimate number density of sources which reproduces the Akeno Ground Air Shower Array (AGASA) observation best. As a result, we find that the most appropriate number density of the sources is $\sim 5 \times 10^{-6}$ Mpc$^{-3}$. This constrains the source candidates of UHECRs. We also demonstrate skymaps of their arrival distribution with the event number expected by future experiments and examine how the EGMF affects their arrival distribution. A main result is diffusion of clustering events which are obtained from calculations in the absence of the EGMF. This tendency allows us to reproduce the observed two point correlation function better.Comment: 13 pages, 14 figures. Revised version, accepted for publication in the Astrophysical Journal. Higher resolution image of fig.5 will be in the published versio

Gastric variceal bleeding caused by an intrahepatic arterioportal fistula that formed after liver biopsy: a case report and review of the literature

An intrahepatic arterioportal fistula is a rare cause of portal hypertension and variceal bleeding. We report on a patient with an intrahepatic arterioportal fistula following liver biopsy who was successfully treated by hepatectomy after unsuccessful arterial embolization. We also review the literature on symptomatic intrahepatic arterioportal fistulas after liver biopsy. A 48-year-old male with bleeding gastric varices and hepatitis B virus-associated liver cirrhosis was transferred to our hospital; this patient previously underwent percutaneous liver biopsies 3 and 6 years ago. Abdominal examination revealed a bruit over the liver, tenderness in the right upper quadrant, and splenomegaly. Ultrasonographic examination, computed tomography, and angiography confirmed an arterioportal fistula between the right hepatic artery and the right portal vein with portal hypertension. After admission, the patient suffered a large hematemesis and developed shock. He was treated with emergency transarterial embolization using microcoils. Since some collateral vessels bypassed the obstructive coils and still fed the fistulous area, embolization was performed again. Despite the second embolization, the collateral vessels could not be completely controlled. Radical treatment involving resection of his right hepatic lobe was performed. For nearly 6 years postoperatively, this patient has had no further episodes of variceal bleeding

Nutrient-Regulated Antisense and Intragenic RNAs Modulate a Signal Transduction Pathway in Yeast

The budding yeast Saccharomyces cerevisiae alters its gene expression profile in response to a change in nutrient availability. The PHO system is a well-studied case in the transcriptional regulation responding to nutritional changes in which a set of genes (PHO genes) is expressed to activate inorganic phosphate (Pi) metabolism for adaptation to Pi starvation. Pi starvation triggers an inhibition of Pho85 kinase, leading to migration of unphosphorylated Pho4 transcriptional activator into the nucleus and enabling expression of PHO genes. When Pi is sufficient, the Pho85 kinase phosphorylates Pho4, thereby excluding it from the nucleus and resulting in repression (i.e., lack of transcription) of PHO genes. The Pho85 kinase has a role in various cellular functions other than regulation of the PHO system in that Pho85 monitors whether environmental conditions are adequate for cell growth and represses inadequate (untimely) responses in these cellular processes. In contrast, Pho4 appears to activate some genes involved in stress response and is required for G1 arrest caused by DNA damage. These facts suggest the antagonistic function of these two players on a more general scale when yeast cells must cope with stress conditions. To explore general involvement of Pho4 in stress response, we tried to identify Pho4-dependent genes by a genome-wide mapping of Pho4 and Rpo21 binding (Rpo21 being the largest subunit of RNA polymerase II) using a yeast tiling array. In the course of this study, we found Pi- and Pho4-regulated intragenic and antisense RNAs that could modulate the Pi signal transduction pathway. Low-Pi signal is transmitted via certain inositol polyphosphate (IP) species (IP7) that are synthesized by Vip1 IP6 kinase. We have shown that Pho4 activates the transcription of antisense and intragenic RNAs in the KCS1 locus to down-regulate the Kcs1 activity, another IP6 kinase, by producing truncated Kcs1 protein via hybrid formation with the KCS1 mRNA and translation of the intragenic RNA, thereby enabling Vip1 to utilize more IP6 to synthesize IP7 functioning in low-Pi signaling. Because Kcs1 also can phosphorylate these IP7 species to synthesize IP8, reduction in Kcs1 activity can ensure accumulation of the IP7 species, leading to further stimulation of low-Pi signaling (i.e., forming a positive feedback loop). We also report that genes apparently not involved in the PHO system are regulated by Pho4 either dependent upon or independent of the Pi conditions, and many of the latter genes are involved in stress response. In S. cerevisiae, a large-scale cDNA analysis and mapping of RNA polymerase II binding using a high-resolution tiling array have identified a large number of antisense RNA species whose functions are yet to be clarified. Here we have shown that nutrient-regulated antisense and intragenic RNAs as well as direct regulation of structural gene transcription function in the response to nutrient availability. Our findings also imply that Pho4 is present in the nucleus even under high-Pi conditions to activate or repress transcription, which challenges our current understanding of Pho4 regulation

A frameshift mutation of the chloroplast matK coding region is associated with chlorophyll deficiency in the Cryptomeria japonica virescent mutant Wogon-Sugi

Wogon-Sugi has been reported as a cytoplasmically inherited virescent mutant selected from a horticultural variety of Cryptomeria japonica. Although previous studies of plastid structure and inheritance indicated that at least some mutations are encoded by the chloroplast genome, the causative gene responsible for the primary chlorophyll deficiency in Wogon-Sugi, has not been identified. In this study, we identified this gene by genomic sequencing of chloroplast DNA and genetic analysis. Chloroplast DNA sequencing of 16 wild-type and 16 Wogon-Sugi plants showed a 19-bp insertional sequence in the matK coding region in the Wogon-Sugi. This insertion disrupted the matK reading frame. Although an indel mutation in the ycf1 and ycf2 coding region was detected in Wogon-Sugi, sequence variations similar to that of Wogon-Sugi were also detected in several wild-type lines, and they maintained the reading frame. Genetic analysis of the 19 bp insertional mutation in the matK coding region showed that it was found only in the chlorophyll-deficient sector of 125 full-sibling seedlings. Therefore, the 19-bp insertion in the matK coding region is the most likely candidate at present for a mutation underlying the Wogon-Sugi phenotype

Gene Knock-Outs of Inositol 1,4,5-Trisphosphate Receptors Types 1 and 2 Result in Perturbation of Cardiogenesis

Rs in cardiogenesis remain unclear.Rs mimicked the phenotype of the AV valve defect that result from the inhibition of calcineurin, and it could be rescued by constitutively active calcineurin.Rs in cardiogenesis in part through the regulation of calcineurin-NFAT signaling