Persistent Primary Cytomegalovirus Infection After Deceased Donor Kidney Transplant: Ganciclovir Susceptibility of Human Cytomegalovirus With UL97 D605E Mutation: A Case Report.

BACKGROUND: Cytomegalovirus (CMV) could cause rejection in immunocompromised patients during early post-renal transplant stage. The American Transplant Society guidelines recommend prophylactic therapy with ganciclovir (GCV) for 3 to 6 months to prevent CMV infections in adult renal transplant patients. However, there is no recommended CMV treatment regimen for pediatric patients. MAIN FINDINGS: We performed deceased donor kidney transplant from an anti-CMV antibody-positive donor to an anti-CMV antibody-negative 15-year-old female recipient with end-stage renal disease caused by bilateral renal hypoplasia. One month after transplant, increase in positive cells in the CMV antigenemia assay indicated a primary CMV infection in the patient, who immediately received GCV. She was switched to foscarnet after 4 months of anti-CMV therapy because of clinical GCV resistance. CMV was isolated from the peripheral blood mononuclear cells but neutralizing antibody was not detected. Isolated CMV was susceptible to GCV and foscarnet, although it carried the UL97 D605E mutation, assumed to be associated with GCV resistance. CONCLUSIONS: The primary CMV infection presented a phenotypic clinical drug resistance, but all recovered CMV isolates were drug-susceptible even if isolated after prolonged anti-CMV therapy, indicating that immune status was more important for recovery from primary CMV infection than anti-CMV therapy.

An inferior mesenteric-caval shunt via the internal iliac vein with portosystemic encephalopathy.

We report here a case of an unusual extrahepatic portosystemic venous shunt in a 37-year-old woman without liver cirrhosis or portal hypertension, who developed portal systemic encephalopathy. Angiography demonstrated an inferior mesenteric-caval shunt characterized by the presence of direct communication of the inferior mesenteric vein with the left internal iliac vein. After the treatment with percutaneous transcatheter embolization of the shunt via a femoral vein approach using coils, she had no episode of portal systemic encephalopathy.

[Nutritional consideration for changes in dietary habit and health promotion practices in community health care; from the view point of selenium].

The Japanese recommended dietary allowances (RDA) for major and some minor nutrients were revised in 1999, and included those for trace elements such as selenium. The requirement of selenium in animals was first recognized in 1957. It has been shown that cellular glutathione peroxidase (GPx) contains selenium but it was subsequently revealed that selenium has diverse biochemical effects, rather than simply functioning in the enzyme. At least twelve different selenoproteins have been identified. The role of selenium has been known as antioxidant, and non-antioxidant mediated through these enzymes. Now, selenium is well recognized as a preventive factor for cancer and cardiovascular diseases. Several dietary studies have shown that the selenium intake in Japan is adequate. One study estimated daily selenium intake to be 104.2 micrograms/day for adults. This value was 2 or 3 times higher than the lower limit of the safe range of dietary selenium (40 micrograms/day for men and 30 micrograms/day for women) estimated by WHO, and also exceeded the newly established RDA of 55-60 micrograms/day for men and 45 micrograms/day for women by the Japanese Public Health Council. However, the established RDA for selenium is tentative because of a lack of information on the 1) chemical forms of selenium in food, 2) differences in absorption rate and bio-availability in the chemical forms, and 3) interactions with other metals and trace elements. There are two potential problems concerning selenium nutrition in Japan. The first problem is that rice, which is the Japanese staple food, contains less than 0.05 microgram/g selenium whereas U.S. rice contains more than 0.3 microgram/g, probably due to differences in soil chemistry. The second problem is that although studies have shown that seafood, fish, shellfish and oysters, contain high levels of selenium (0.4-0.5 microgram/g), these being the main selenium source for Japanese, the bio-availability in fish is low. Thus, it is likely that the selenium status of those Japanese who eat an imbalanced diet is not sufficient or is not optimal even if the intake exceeds the RDA. Further studies are needed so that community health care specialists have available appropriate knowledge on the role of trace nutrients, including selenium, in human nutrition and health, to promote proper nutritional practices in the community.

CDNA cloning of radish (Raphanus sativus) myrosinase and tissue-specific expression in root.

Two cDNA clones of myrosinase (thioglucoside glucohydrolase, EC 3.2.3.1) were isolated from radish (Raphanus sativus) seedlings. Both clones were identified as MB (B type myrosinase) from their sequence homology at the amino acid level to MBs cloned from other Brassicaceae species. The tissue distribution of gene expression and enzyme activity of myrosinase corresponded well to the site of glucosinolate accumulation in different tissues of radish. The myrosinase-glucosinolate system was localized in the cotyledons in the seedlings and in the peel of the root in the mature plant. Tissue printing analysis showed that myrosinase mRNA and activity were localized in the epidermis and vascular cambium that were present in the peripheral part of the root but few signals were detected in the parenchyma inside of the vascular cambium. Since the myrosinase-glucosinolate system is known to be a defense system in higher plants, the localization of the myrosinase-glucosinolate system in the peel of the root may act to protect the sink organ from the attack of herbivores or pathogens in soil.

Serum thrombopoietin levels in patients with chronic hepatitis and liver cirrhosis.

OBJECTIVE: Thrombocytopenia is a common manifestation of cirrhosis. The aim of this study was to examine the relationship between serum thrombopoietin concentrations, circulating platelet levels, and the stage of hepatic fibrosis in patients with chronic viral hepatitis. METHODS: The study included 48 patients with chronic viral hepatitis (14 with stage 1 fibrosis; five with stage 2 fibrosis; three with stage 3 fibrosis; 26 with cirrhosis) and 30 healthy volunteers. Serum thrombopoietin levels were measured using an enzyme-linked immunosorbent assay. Spleen size, platelet counts, and prothrombin time were measured. RESULTS: Thrombopoietin levels of patients with fibrosis stage 1 (2.50 +/- 1.60 fmol/ml) or stage 2 (1.89 +/- 0.65) were significantly higher than those in patients with cirrhosis (1.21 +/- 0.55) or healthy volunteers (1.26 +/- 0.74). Mean platelet counts of patients with cirrhosis (8.0 +/- 4.6 x 10(4)/microl) were significantly lower than those with fibrosis stage 1 (18.6 +/- 3.9) or stage 2 (16.0 +/- 5.8), or healthy volunteers (24.5 +/- 7.3). Patients with cirrhosis had larger spleens (30.9 +/- 18.4 cm2) than those with fibrosis stage 1 (18.2 +/- 6.4). Platelet counts showed a significant inverse relationship to spleen size (p = -0.51, p < 0.0005) and a significant positive relationship with thrombopoietin levels (p = 0.34, p < 0.02). Thrombopoietin levels were significantly correlated to prothrombin time (p = 0.45, p < 0.005). CONCLUSIONS: Serum thrombopoietin levels are elevated in patients with an early stage of chronic viral hepatitis. As the disease progresses from mild fibrosis to cirrhosis, decreased production of thrombopoietin may contribute to the further development of thrombocytopenia in cirrhosis.

Varicella pneumonia in a healthy adult presenting with severe respiratory failure.

We describe a case of varicella pneumonia in a 24-year-old healthy man presenting with severe respiratory failure. A chest radiograph showed diffuse, bilateral airspace consolidation; additional complications included liver dysfunction and thrombocytopenia. However, treatment with intravenous acyclovir and gamma-globulin improved his clinical symptoms and signs. A greater than four-fold change in paired titers of the varicella-zoster virus antibody was observed. Bronchoalveolar lavage performed during the recovery phase revealed increased total cell and lymphocyte counts and a decreased CD4:CD8 ratio of T lymphocytes. Transbronchial lung biopsy findings were compatible with a diagnosis of interstitial pneumonia.

[Synthesis of new antirusty disinfectants. I].

New quaternary ammonium salts [N-alkyl-N-2-hydroxyethyl-N,N-dimethylammonium ethyl phosphate (21, 22), isopropyl phosphate (23), n-butyl phosphate (24) and N-alkyl-N-2-hydroxy-3-phenoxypropyl-N,N-dimethylammonium ethyl phosphate (25, 26), isopropyl phosphate (27), n-butyl phosphate (28) and bis(N-alkyl-N-2-hydroxy-3-phenoxypropyl-N,N-dimethylammonium) malate (29), fumarate (30), succinate (31), adipate (32) and N-alkyl-N-2-hydroxy-3-phenoxypropyl-N,N-dimethylammonium tartrate (33)] were synthesized by alkylation of the corresponding trialkylammonium salts with various epoxy compounds. The new quaternary ammonium salts showed much greater bactericidal activities and antirusting effects than those of benzalkonium chloride. They had also good compatibilities since no precipitate was observed if the solution of any anionic surface active agents were added to the solution of these new quaternary ammonium salts. This property is the same as that of amphoteric surface active agents.

X-ray study of baker's yeast lipoamide dehydrogenase at 4.5 A resolution by molecular replacement method.

The molecular structure of lipoamide dehydrogenase from baker's yeast has been determined at 4.5 A resolution by molecular replacement techniques using the known structure of human erythrocyte glutathione reductase as a starting model. The enzyme crystallizes in the space group P2(1)2(1)2(1) with a = 98.6(2), b = 162.0(2), c = 69.4(2) A. There is one molecule per asymmetric unit. The enzyme is a dimeric protein of identical subunits related by a local two-fold symmetry. Comparison of the tertiary structures between glutathione reductase and the present enzyme shows that the folding is almost the same except for the N and C termini, although some slight shortening or shifting of alpha-helices was found in the electron density map. FAD molecules are found at similar positions to those of glutathione reductase. Since the amino acid residues around FAD and NAD binding sites and at the reaction centers of the two enzymes are strongly conserved, the lipoamide dehydrogenase may catalyze the opposite reaction through a similar mechanism to that proposed for glutathione reductase. The newly found C terminus is located near the edge of a deep cave at the interface between the two subunits. These additional 18 residues form a narrow entrance to the cave, in which the long chain of the dihydrolipoyl moiety of lipoate acetyltransferase will be bound.

Studies of protein-nucleic acid interactions using model crystals.

For the mutual recognition between protein and nucleic acid, specific interactions between the components of both polymers should be properly combined in a fitting scheme of secondary or tertiary structures. We call these combinations elementary interactions between protein and nucleic acid. The interactions were investigated using the model crystals that contain side chains of amino acid and a nucleic acid base. Taking C, T, U, A, and G as base and hydroxyl, carboxyl, carbamoyl, imidazolyl, phenyl, hydroxyphenyl, and indolyl groups as side chains of amino acid, several combinations were extensively studied. Interaction patterns between complementary base pairs and amino acids were also examined using ternary model systems. Several characteristics are observed in the model crystals, for instance, stabilization of stacking between the bases and histidine by the protonation of the latter, common hydrogen bonding patterns between bases and a hydroxyl or carboxyl group by reversal of donor-acceptor relationship or ionization. UV, NMR experiments and calculation by molecular orbital methods revealed energetic aspects of these interactions. A structural constraint is derived between the hydrogen bonds and the secondary structural fitting of an alpha-helical segment into the major groove of B-DNA. In terms of elementary interactions, stereochemical interpretations are given for the selectivity and enzymatic reaction of RNAase, binding of cro repressor to operator and initiation and elongation in the assembly of tobacco mosaic virus.

Model for interactions of amino acid side chains with Watson-Crick base pair of guanine and cytosine: crystal structure of 9-(2-carbamoylethyl)guanine and 1-methylcytosine complex.

As a model of interaction between the guanine-cytosine base pair and carbamoyl group, the crystal structure of 9-(2-carbamoylethyl)guanine-1-methylcytosine complex has been studied by X-ray method. The crystal data are a = 8.540 (1) A, b = 12.693 (3) A, c = 14.249 (2) A, beta = 94.02 (1) degrees, space group P21/c, Z = 4, dm = 1.50, dc = 1.49 g cm-3, and R = 0.10 for 1035 reflections. The bases form a Watson-Crick pair, and the carbamoyl group is hydrogen bonded with O(6) of guanine and N(4) of cytosine in the adjacent pairs. A structural correlation has been found between the hydrogen-bonding pattern and the secondary structural fitting of alpha-helical segment with B-form DNA.

Crystal structure of 3-(adenin-9-yl)propionhistamide hydrochloride monohydrate and the role of protonation in protein-nucleic acid interactions.

The three-dimensional structure of 3-(adenin-9-yl)propionhistamide hydrochloride, as a model of interactions between the protonated imidazolyl group and adenine moiety, has been determined by X-ray crystallography. The crystal data are a = 10.314 (1), b = 7.854 (1), c = 20.780 (1) A, beta = 92.765 (4), Z = 4, Dm = 1.32 g X cm-3, space group P2(1)/n. The imidazolium group interacts with adenine moiety by stacking. A comparison with the related neutral derivatives leads to a hypothesis that adenine stacks with the protonated, but not with the neutral, imidazolyl group. Such a characteristic behaviour of the imidazolyl group depending on protonation was shown by ultraviolet and NMR spectroscopy, and by polarographic experiments in solution. We note that a role of the essential histidine in RNAase reaction is a switch between capture and ejection of the substrate, which depends upon proton uptake and its release, respectively.

A role of elementary interactions between nucleic-acid base and amino-acid side chains in specificity of ribonuclease.

Several X-ray structures of model crystals that contain hydroxyl group and nucleic-acid bases suggest that hydroxyl group interacts preferentially with pyrimidines than with purines through hydrogen bonds. This explains a role of Thr 45 and Ser 123 at the B1 site of RNAase A. The stacking energies of nucleic-acid bases with the protonated imidazolyl group are estimated to be in the order of C greater than A greater than G greater than U from 1H-NMR spectra and CNDO/2 calculations. Such interactions, in addition to hydrogen bondings, would stabilize the binding of substrates at the B2 site.

Conformations of fortimicins and three-dimensional structure-activity relationship in the aminoglycoside antibiotics.

The fortimicins are pseudodisaccharide antibiotics consisting of purpurosamine and fortamine moieties which are connected through an alpha-linkage. NMR spectra indicate that the fortamine ring in fortimicin A takes a chair conformation which corresponds to an inverted one in the conformation of fortimicin B free base. Fortimicin A is unstable in solution, and we were unable to obtain any crystals of it. To elucidate the structure of fortimicin A and to clarify the stereochemistry of fortimicins, we have undertaken to calculate their empirical force-fields starting from the X-ray structures of fortamines and fortimicin B free base. Nuclear Overhauser enhancement data were also employed to confirm the calculated relative orientation of the two rings around the glycosidic linkage. The 3-dimensional structure-activity relationship of aminoglycoside antibiotics is discussed on the basis of these results.

Synthesis and immunological activity of 5,6,6a,8,9,11a-hexahydronaphth[1',2':4,5]imidazo[2,1-b]thiazoles and 5,6,6a,9,10,11a-hexahydroanaphth[2',1':4,5]imidazo[2,1-b]thiazoles.

A series of 5,6,6a,8,9,11a-hexahydroanaphth[1',2':4,5]imidazo[2,q-b]thiazoles (17 and 20) and 5,6,6a,9,10,11a-hexahydronaphth[2',1':4,5]imidazo[2,1-b]thiazoles has been synthesized with cis- and/or trans-1,2-diamino-1,2,3,4-tetrahydronaphthalenes as the key intermediates and subsequently evaluated for immunological activity (effects on antibody formation and delayed-type hypersensitivity reaction). Among the compounds tested trans-5,6,6a,8,9,11a-hexahydronaphth[1',2':4,5]imidazo[2,1-b]thiazole (trans-17a) and (+/-)-5,6,6a beta,8,9,11a alpha-hexahydro-8 beta-hydroxy-9 beta-methyl-8 alpha-phenylnaphth[1',2':4,5]imidazo[2,1-b]thiazole (20a) showed the largest immunological activity in mice with a magnitude comparable to that of levamisole and were found to be considerably less toxic than levamisole in acute toxicological study. The structures of 18a and 20a were determined by X-ray crystallography.

X-ray analysis of Co-C bond cleavage in the crystalline state.

During serial structure analysis of cobaloxime derivatives, aimed at interpreting the catalytic capability of the asymmetric hydrogenation, we have found that the crystal of R-alpha-cyanoethyl (S-alpha-methylbenzylamine)-cobaloxime changes its unit cell dimensions by X-ray exposure without degradation of a single crystal form. The rate of the change was so slow that it was possible to collect the intensity data for several intermediate stages. We have proved, by calculating electron density in each stage, that the change reflects the racemisation of the cyanoethyl group.