Dietary phytoestrogens and cancer: in vitro and in vivo studies

Thirty postmenopausal women (11 omnivores, 10 vegetarians and 9 apparently healthy women with surgically removed breast cancer) were investigated with regard to the association of their urinary excretion of estrogens, lignans and isoflavonoids (all diphenols) with plasma sex hormone binding globulin (SHBG). A statistically significant positive correlation between urinary total diphenol excretion and plasma SHBG was found which remained statistically significant after elimination of the confounding effect of body mass determined by body mass index (BMI). Furthermore we found a statistically significant negative correlation between plasma SHBG and urinary excretion of 16 alpha-hydroxyestrone and estriol which also remained significant after eliminating the effect of BMI. Furthermore we observed that enterolactone (Enl) stimulates the synthesis of SHBG by HepG2 liver cancer cells in culture acting synergistically with estradiol and at physiological concentrations. Enl was rapidly conjugated by the liver cells, mainly to its monosulfate. Several lignans and the isoflavonoids daidzein and equol were found to compete with estradiol for binding to the rat uterine type II estrogen binding site (the s.c. bioflavonoid receptor). It is suggested that lignans and isoflavonoids may affect uptake and metabolism of sex hormones by participating in the regulation of plasma SHBG levels and in this way influence their biological activity and that they may inhibit cancer cell growth like some flavonoids by competing with estradiol for the type II estrogen binding sites.

Induction of activated killer cells from human lymphocytes by medullasin (a serine protease in bone marrow cells)

Medullasin, a serine protease found in human bone marrow cells, has been shown to induce activated killer (AK) cells that lyse both natural killer (NK)-sensitive and -resistant cloned target cells from human lymphocytes. In addition to all the tested malignant cell lines, malignant cells obtained from all patients with acute myelocytic leukaemia, chronic lymphocytic leukaemia and lymphoblastic leukaemia were lysed by AK cells induced by medullasin. Maximum induction was achieved when lymphocytes were incubated at 37 degrees for 60 min in the presence of medullasin (20 micrograms/ml). The cytotoxicity of AK cells induced by medullasin treatment (200 micrograms/ml, 37 degrees for 60 min) was greater than that of lymphokine-activated killer (LAK) cells produced by 500 U/ml of interleukin-2 (IL-2). Cytokines such as IL-2 or interferon (IFN) are not considered to be involved in the medullasin induction of AK cells for the following reasons: (1) neither IL-2 nor IFN activity were detected in the supernatant of lymphocytes treated with medullasin; (2) the supernatant of lymphocytes treated with medullasin failed to induce AK cells; and (3) the presence of antibodies against IL-2 or IFN did not influence the effect of the protease. By employing monoclonal antibodies to the surface antigens of lymphocytes and a panning method using plastic dishes coated with anti-mouse IgG goat Fab', progenitor as well as effector cells were found to be CD16-positive cells.

Cloning and sequence analysis of cDNA encoding aspartate aminotransferase isozymes from Panicum miliaceum L., a C4 plant

The cytosolic and mitochondrial isozymes of aspartate aminotransferase (AspAT) function in the C4 dicarboxylate cycle of photosynthesis. We constructed a cDNA library from leaf tissues of Panicum miliaceum, an NAD-malic-enzyme-type C4 plant and screened the library for AspAT isozymes. A full-length cDNA clone for cytosolic AspAT was isolated. This clone contains an open reading frame that encodes 409 amino acids. We also isolated two cDNA clones for different precursors of mitochondrial AspAT. Comparing these two sequences in the coding regions, we found 12 amino acid substitutions out of 28 base substitutions. The encoded amino acid sequences predict that mitochondrial AspAT are synthesized as precursor proteins of 428 amino acid residues, which each consist of a mature enzyme of 400 amino acid residues and a 28-amino-acid presequence. This prediction coincides with the observation that the in vitro translation product of the mRNA for mitochondrial AspAT was substantially larger than the mature form. A comparison of the amino acid sequences of the AspAT isozymes from P. miliaceum with the published sequences for the enzymes from various animals and microorganisms reveals that functionally and/or structurally important residues are almost entirely conserved in all AspAT species.

Expression of Maize Ferredoxin cDNA in Escherichia coli: Comparison of Photosynthetic and Nonphotosynthetic Ferredoxin Isoproteins and their Chimeric Molecule

Maize (Zea mays L.) has two types of ferredoxin (Fd) differentially expressed in photosynthetic and nonphotosynthetic organs. A cDNA fragment encoding the mature polypeptide of Fd III, an Fd isoprotein of the nonphotosynthetic type, was expressed in Escherichia coli, and the Fd was synthesized as a holo-form assembled with the [2Fe-2S] cluster, which was completely identical with authentic Fd III prepared from maize roots. This expression system made it possible to prepare Fd present at fairly low levels in plants in amounts sufficient for functional and structural studies. Comparison of electron transfer activity of Fd III with that of Fd I, an Fd isoprotein of the photosynthetic type, showed that Fd III was superior as an electron acceptor from NADPH, and Fd I was superior as an electron donor for NADP(+), in reactions catalyzed by Fd-NADP(+) reductase from maize leaf. The circular dichronism spectra of the two Fds also indicated a subtle difference in the geometry of their iron-sulfur clusters. These results are consistent with the view that photosynthetic and nonphotosynthetic Fds may be functionally differentiated. An artificial chimeric Fd, Fd III/Fd I, whose amino-terminal and carboxylterminal halves are derived from the corresponding regions of Fd III and Fd I, respectively, showed an activity and CD spectrum significantly similar to those of Fd I. This suggests that 18 amino acid substitutions between Fd III and Fd III/Fd I alter the properties of Fd III so that they resemble those of Fd I.

Rolling-circle replication of the plasmid pKYM isolated from a gram-negative bacterium

Plasmid pKYM isolated from a Gram-negative bacterium encodes a Rep protein that is essential for plasmid replication. A comparison of Rep protein from pKYM to Rep proteins encoded by other plasmids shows that it has homology to Rep proteins of the pUB110 plasmid family from Gram-positive bacteria. These plasmids replicate by a rolling-circle mechanism in which a tyrosine residue in the Rep protein acts as the acceptor for the 5' end of the single-strand break introduced by the Rep protein. A Tyr----Phe substitution in the pKYM Rep protein abolishes its activity. Strand-specific single-stranded circular plasmid DNA can be recovered from the cells carrying pKYM and thus we propose that the plasmid pKYM replicates by a rolling-circle mechanism.

Plastid import and iron-sulfur cluster assembly of photosynthetic and nonphotosynthetic ferredoxin isoproteins in maize

We have previously isolated and characterized two cDNAs of maize (Zea mays) ferredoxin (Fd) isoproteins, which are differentially expressed in photosynthetic and nonphotosynthetic organs, and in response to illumination of the developing seedlings (Hase T, Kimata Y, Yonekura K, Matsumura T, Sakakibara H [1991] Plant Physiol 96: 77-83). To clarify the biosynthetic pathway of Fds present in the different organs, precursors of the two Fd isoproteins synthesized by in vitro transcription and translation were examined to determine whether they are imported to chloroplasts and etioplasts. Precursors for both Fd I and Fd III, a leaf-specific, photosynthetic isoprotein and a constitutive, nonphotosynthetic one, respectively, were imported into chloroplasts and processed to the mature size. Some of the mature-sized molecules inside the organelles were found to be assembled with an iron-sulfur cluster. The cluster assembly occurred without tight coupling to the translocation and processing steps of the protein import, and the process was time and temperature dependent and did not require light. Etioplasts were also capable of importing the precursor of Fd III and assembling the cluster. These combined data show that the constitutive, nonphotosynthetic Fd has the ability to become localized in plastids as a functional molecule.

The primary structure and elastinolytic activity of medullasin (a serine protease of bone marrow)

The amino acid sequence around the carboxyl terminal of medullasin was determined by digesting the protease with carboxypeptidase Y and measuring the rate of release of amino acids from the carboxyl terminal. By considering the structure of the protease's cDNA, we concluded that His-238 is the C-terminal residue of medullasin. Therefore, medullasin is composed of 238 amino acid residues with Ile as the amino terminal and His as the carboxyl terminal. Medullasin is essentially devoid of elastinolytic activity, because it failed to digest orcein-elastin.

Isotope dilution gas chromatographic-mass spectrometric method for the determination of lignans and isoflavonoids in human urine, including identification of genistein

We describe an isotope dilution gas chromatographic-mass spectrometric method for the quantitative determination of the lignans enterolactone, enterodiol and matairesinol and the isoflavonoids daidzein, equol, O-desmethylangolensin and genistein in urine. Furthermore we present the gas chromatographic/mass spectrometer identification of genistein. Urine samples were extracted on Sep-Pak cartridges, conjugated fractions were isolated by chromatography on the acetate form of DEAE-Sephadex and deuterated internal standards of all seven compounds were added to the samples before hydrolysis. The hydrolysate was extracted on a Sep-Pak cartridge and following chromatography on the acetate form of QAE-Sephadex two fractions were obtained: Fraction 1 contained equol, enterolactone, enterodiol, matairesinol and all estrogens and fraction 2 contained O-desmethylangolensin, daidzein and genistein. The latter was ready for gas chromatography/mass spectrometry, but the first one was further purified to eliminate the estrogens by chromatography on the carbonate form of QAE-Sephadex. Following silylation, the samples were analyzed by combined capillary column gas chromatography/mass spectrometry in the selective ion monitoring mode. The within-assay imprecision varied from 0.8-15.2% (mean 8.7%) and the between-assay imprecision from 4.1-13.9% (mean 9.3%), depending on compound and concentration level. The mean recovery of authentic standards added to urine extracts before hydrolysis varied from 96.6 to 105.5%. Values obtained from 10 Finnish omnivorous men are presented. Individual values for matairesinol (excretion range 3.3-59.9 nmol/24 h) and genistein (range 21.8-1180 nmol/24 h) in human urine have never been published before.

Growing and in-situ processing of cells on BEEM capsule caps for scanning electron microscopy

A simple technique for processing cells grown on BEEM capsule caps for scanning electron microscopic (SEM) observation is described. The cells adhere to a substratum on the inner surface of caps coated with either an egg white-polyvinylpyrrolidone solution or a polylysine solution in the case of eukaryotic cells and an agar solution in the case of bacteria. The adhering cells are cultured and then processed in situ for SEM observation. Electron micrographs revealed details of the shape of the cells growing on the surface of the substrate. The technique seems to be particularly well suited for observing sequential morphological changes of cells, bacteria, and protozoa cultured under a specified experimental condition as well as of interactions between cells and parasitic microorganisms.

Molecular cloning and differential expression of the maize ferredoxin gene family

In maize (Zea mays L.), four ferredoxin (Fd) isoproteins, Fd I to Fd IV, are differentially distributed in photosynthetic and nonphotosynthetic organs of young seedlings (Y Kimata, T Hase [1989] Plant Physiol 89: 1193-1197). To understand structural characteristics of the Fd isoproteins and molecular mechanism of the differential expression of their genes, we have cloned and characterized three different maize Fd cDNAs. DNA sequence analyses showed that two of the cDNAs encoded the entire precursor polypeptides of Fd I and Fd III, which were composed of 150 and 152 amino acid residues, respectively, and the other encoded a 135 amino acid precursor polypeptide of Fd not yet identified. High degrees of homologies were found in the deduced amino acid sequences of mature regions of these Fd isoproteins, but the transit peptide of Fd III differed considerably from those of other Fd isoproteins. Fd I and the unidentified Fd were encoded mainly with codons ending in C or G, but such strong codon bias was not seen in Fd III. Gene specific probes for each cDNA were used to probe Northern blots of RNA isolated from leaves, mesocotyls, and roots of maize seedlings. The gene transcripts for Fd I and the unidentified Fd were restricted to leaves and their levels increased markedly upon illumination of etiolated seedlings, whereas that for Fd III was detected in all organs and its accumulation was not light dependent. This organ specific accumulation of Fd mRNAs corresponds exactly to the distribution pattern of Fd isoproteins.

Molecular cloning and characterization of complementary DNA encoding for ferredoxin-dependent glutamate synthase in maize leaf

The sequence of ferredoxin-dependent glutamate synthase (EC 1.4.7.1) mRNA from maize has been determined. Complementary DNAs were isolated from a cDNA library of light-induced leaf poly(A)+ RNA constructed in an expression vector. An open reading frame beginning at an ATG codon at nucleotide 328 of the longest cDNA (5617-bases long) encoded 1616 amino acid residues. The amino terminus of the purified mature enzyme coincided with the cysteine residue at position 98 of the predicted sequence. This enzyme is homologous with the large subunit of Escherichia coli NADPH-dependent glutamate synthase having about 42% identical residues between the two proteins. The enzyme also contains a short region similar to a potential FMN-binding region of yeast flavocytochrome b2. The cDNA hybridizes to an RNA band about 5.5 kilobases whose steady-state level is markedly increased upon illumination of etiolated maize seedlings. Analysis of genomic DNA indicates the presence of a single-copy gene for ferredoxin glutamate synthase in maize.

Comparative study of mouse brains infected with Japanese encephalitis virus by intracerebral or intraperitoneal inoculation

The brains of mice infected with Japanese encephalitis (JE) virus by intracerebral inoculation (IC), intraperitoneal inoculation with sham intracerebral inoculation (IP+sIC), and intraperitoneal inoculation (IP) were studied by light and electron microscopy. The mortality rates and mean survival days were 100% and 4.8 days for the IC group, 92% and 9.0 days for the IP+sIC group, and 58% and 13.4 days for the IP group. Accordingly, the brain samples of sick mice were examined by light and electron microscopy 4 days post-inoculation (p.i.) for the IC group, 7 days p.i. for the IP+sIC group and 12 days p.i. for the IP group. In light microscopy, the mouse brains in the IC group showed little inflammatory change with only mild generalized glial-cell proliferation and mononuclear cell infiltration. In electron microscopy, however, a majority of neurons in the brain were seen to be infected with virus that replicated exclusively in the neuronal secretory system, including rough endoplasmic reticulum (RER) and the Golgi apparatus. In contrast, light microscopic observation of the brains from the IP+sIC and the IP groups showed prominent inflammatory changes with leucocytic infiltration and perivascular cuffing. Neuronal degeneration and neuronophagia were also prominent. In electron microscopy, neurons were infected in the same manner as in the IC group, but showed more advanced degenerative changes with marked cytoplasmic rarefaction and frequent neuronal disintegration. Mononuclear cells were frequently found in direct contact with degenerating and disintegrating neurons. The results showed that (a) the basic process of JE virus replication in brain neurons was present in the three groups of mice, (b) in the peripherally inoculated mice the process was accompanied by inflammatory reaction with resultant neuronal destruction, and (c) breach in the blood-brain barrier at the time of peripheral viral inoculation played an important role in the viral invasion of the CNS.

Structure of the [2Fe-2S] ferredoxin I from the blue-green alga Aphanothece sacrum at 2.2 A resolution

Crystals of a [2Fe-2S] ferredoxin (Fd) I with a relative molecular mass of 10,480 were obtained from the blue-green alga Aphanothece sacrum. Each asymmetric unit of the crystal contains four molecules. An electron density map calculated by the single isomorphous replacement method with the anomalous dispersion at 2.5 A resolution was refined by averaging the four molecules in the asymmetric unit. Positional and isotropic thermal parameters for the non-hydrogen atoms of the four molecules and 158 water molecules were refined to an R-factor (R = sigma[Fo-Fc[/sigma Fo) of 0.23 by the restrained least-squares method. The estimated root-mean-square (r.m.s.) error for the atomic positions is 0.3 A. The r.m.s. deviations of equivalent C alpha atoms of the asymmetric-unit molecules superposed by the least-squares method average 0.35 A. The Fd molecule has a structure like the beta-barrel in the molecule of the [2Fe-2S] Fd from Spirulina platensis. A [2Fe-2S] cluster is bonded covalently to the protein molecule by four Fe-S, in which three of the Fe-S bonds are in a loop segment from position 38 to 47. The hydrophobic core inside the beta-barrel is formed by seven conservative residues: Val15, Val18, Ile24, Leu51, Ile74, Ala79 and Ile87. The molecular surface around Tyr23, Tyr80 and the active center may interact with ferredoxin-NADP+ reductase. One of the two iron atoms of the [2Fe-2S] cluster should be more easily reduced than the other because of differences in the hydrogen-bonding scheme and the hydrophobicity around the atoms.

Entry and replication of Japanese encephalitis virus in cultured neurogenic cells

The entry mode and growth pattern of Japanese encephalitis (JE) virus in mouse neuroblastoma N18TG2 cells and mouse neuroblastoma x rat glioma NG108-15 hybrid cells were studied by electron microscopy. At two minutes after inoculation, JE virions adsorbed onto and directly penetrated through the plasma membrane of the hybrid cells, whereas virions did not adsorb nor entered the neuroblastoma cells. Correspondingly, the hybrid cells showed assembling progeny JE virions in the cisternae of rough endoplasmic reticulum (RER) 1 day postinoculation (p.i.) although virions were rarely found on the following days during the experiment. On the other hand, progeny virions did not assemble in the RER cisternae of the neuroblastoma cells throughout the experiment. The morphologic observations, therefore, suggest that (a) the hybrid cells express JE-virus receptors which facilitate the viral attachment onto and entry into the cells, while the neuroblastoma cells do not and (b) JE virus replicates very poorly after the entry into the hybrid cells while it does not replicate at all in the neuroblastoma cells. The virus titrations of the media of the neuroblastoma and hybrid cell cultures showed only titers indicative of residual virus of the inoculum that progressively decreased during the experiment. The present results show therefore that of the two neurogenic cell culture lines studied only the hybrid cell line can be used for the study of viral entry and replication, although it is not suited for virus production. Possible reasons for the poor replication of JE virus in the hybrid cells are discussed.

Effects of butenafine hydrochloride, a new benzylamine derivative, on experimental dermatophytosis in guinea pigs

Butenafine hydrochloride, N-4-tert-butylbenzyl-N-methyl-1-naphthalenemethylamine hydrochloride (butenafine), is a novel antifungal agent of the class of benzylamine derivatives. Butenafine was investigated for its activity against guinea pig dermatophytosis caused by Trichophyton mentagrophytes or Microsporum canis in comparison with those of naftifine, tolnaftate, clotrimazole, and bifonazole. Topical butenafine showed excellent efficacy against dermatophytosis when it was applied once daily, and the effect was superior to those of all four reference drugs. When applied once at 24 or 48 h before infection, the drug exhibited excellent prophylactic efficacy against experimental T. mentagrophytes infection. The concentrations of butenafine in animal skin at 24 and 48 h after application of 0.2 ml of a 1% solution were several hundred times higher than those required to kill T. mentagrophytes and M. canis. The good efficacy of butenafine against dermatophytosis may be attributable to its fungicidal activity and long retention in the skin after topical application.

[Identification and characterization of the two promoters of plasmid pKYM]

Plasmid pKYM is a multicopy plasmid isolated from Shigella sonnei and multiples stably in Escherichia coli. The plasmid encodes Rep protein which is essential for its multiplication and synthesizes cop ribonucleic acid (RNA) which is a short RNA complementary to the 5' region of rep m-RNA. This RNA controls the copy number and the incompatibility of the plasmid. The previous analysis located the promoters of rep m-RNA RNA (PR) and cop RNA (PL) in the inc region. This report confirmed the presence of these promoters by analyzing the RNAs isolated from the cells carrying pKYM and those synthesized in vitro. The initiation sites of these transcriptions were also determined. Analysis of in vivo RNA suggested that the quantity of cop RNA whose size was about 90 nucleotides was larger than that of rep m-RNA and these RNAs easily formed RNA-RNA hybrid. The analysis also suggested that the synthesis of rep m-RNA was repressed by cop RNA and Rep protein itself.

Ultrastructural changes of mouse brain neurons infected with Japanese encephalitis virus

Ultrastructural changes of mouse brain neurons infected intracerebrally with Japanese encephalitis (JE) virus were studied. JE virus selectively infected the neurons, causing ultrastructural changes in association with viral replication in the cellular secretory system, principally involving rough endoplasmic reticulum (RER) and the Golgi apparatus. In the early phase of infection, RER of infected neurons showed hypertrophic changes, containing assembling virions within its dilated cisternae. In the later phase, the RER became cystic and degenerative and dissolved into the cytoplasm. The Golgi apparatus also contained in its saccules multiple virions, presumably transported from the RER cisternae, which were then released into the cytoplasm within coated vesicles for secretory-type exocytosis. In the process, the Golgi apparatus also fragmented and degenerated through vesiculation, vacuolation, and dispersion. Thus, the JE virus infection of neurons resulted in obliteration of RER and the Golgi apparatus, leaving behind the rarefied cytoplasm devoid of these organelles. However, destruction of the neurons themselves was not prominent and infected neurons in the later phase of infection showed some regenerative changes of these membranous organelles. The cause of death of infected animals, therefore, appeared to be extensive neuronal dysfunction rather than neuronal destruction in the CNS.

[A hybrid artificial liver system composed of primary cultured canine hepatocytes]

The usefulness of newly device hybrid artificial liver system was evaluated in anhepatic dogs. The artificial liver module was composed of 60 to 80gm. primary cultured canine (Beagle) hepatocytes which were attached to 200 borocillicate glass plates. Total hepatectomy were done through cavo-caval and porto-caval shunt method using Anthron catheter to 14 dogs. Dogs were divided into following three groups. Group I; no treatment (n = 6) Group II; plasma perfusion (n = 4) Group III; treated with the artificial liver systems (n = 4) The survival times were 21.3 +/- 5.6, 27.8 +/- 4.0, and 55.0 +/- 11.3 hours in group I, II, and III, respectively. The longest survival time was 65 hours in one of group III dogs. APTT levels in group I and II increased more than 100 sec. within 24 hours. On the other hand it was maintained within 50 sec. during 54 hours treatment in group III. Ammonia levels in group I and II extremely increased over 2000ng/dl. In group III, it was less than 400ng/dl for 54 hours. Plasma amino acid levels in group I and II (Glutamine, Arginine, AAA) revealed significantly higher than in group III at 18 hours after operation. It is concluded that the newly device hybrid artificial liver system was useful for in vivo liver support.

Low molecular weight peptide inhibitors of medullasin: purification and structure

Two low molecular weight peptide inhibitors of medullasin were isolated from human bone marrow cells. Determination of their amino acid composition and amino acid sequence revealed that one inhibitor was composed of 36 amino acid residues and the other 34 amino acid residues which are identical with the C-terminal portions (Formula; see text) of the beta-chain of human hemoglobin. These two peptides when synthesized also showed the same degree of inhibitory effect on medullasin activity as the natural products. Neither the N-terminal portion of the inhibitor, composed of 21 amino residues, nor the C-terminal peptide, composed of 20 amino acids, inhibited medullasin activity. Medullasin was inhibited reversibly and non-competitively against by these inhibitors and was the most effectively inhibited serine protease among several tested.

Metabolism of antipyrine and m-xylene in rats after prolonged pretreatment with xylene alone or xylene with ethanol, phenobarbital or 3-methylcholanthrene

1. The metabolic disposition of antipyrine (AP) and m-xylene (XYL) has been studied in rats pretreated for a prolonged period with XYL, dosed alone or in combination with ethanol, phenobarbital (PB), or 3-methylcholanthrene (MC). 2. XYL inhalation exposure at 300 ppm in air (7 h/day, 4 days/week, for 1 or 4 weeks) did not alter the total 24-h recovery of AP and its major metabolites in urine, but the excretion profile changed compared with controls: 3-hydroxymethylantipyrine (3-HMA) increased (less than or equal to 14%, P less than 0.001), norantipyrine (NORA) (less than or equal to 23%, P less than 0.01) and AP (less than or equal to 53%, P less than 0.01) decreased. 4-Hydroxyantipyrine (4-OHA) was unchanged. 3. Oral dosage of XYL at 800 mg/kg per day (5 days/week, for 12 days) altered the metabolic disposition of AP similarly to inhalation. 4. XYL + ethanol did not alter the xylene-type effect on AP metabolism. This was at variance with the changes following XYL + PB and, to a greater extent, XYL + MC pretreatments: 4-OHA increased (53-74%, P less than 0.01), 3-HMA (11-42%, P less than 0.05) and AP (greater than or equal to 50%, P less than 0.05) decreased. The effect on NORA was less clear. 5. XYL pretreatment accelerated metabolic disposition of its major urinary metabolite, methylhippuric acid (MHA) and formation of thioethers. 6. Thioether excretion in 24 h urine was enhanced about 10-fold after XYL inhalation and 20-fold after oral administration. Only XYL + PB treatment enhanced further the excretion of xylene-derived thioethers (P less than 0.05). 7. Drug-metabolizing activity (phase I and II reactions) in liver, lung and kidney showed that the treatments resulted in marked and differential biochemical alterations. 8. In conclusion, m-xylene enhanced the rate of its own metabolism and induced differential changes on urinary AP metabolite profile depending on the pretreatment.

[Biological characteristics of plasmid carrying a repeated deoxyribonucleic acid sequence]

It was found that a plasmid which had a foreign deoxyribonucleic acid (DNA) between two repeated sequences did not multiply in E. coli recBCsbcB, even if it multiplied in wild-type E. coli, E. coli recBC or E. coli recBCsbcBrecF when the insert was longer than 351 base pair. The multiplication of these plasmids were, however, inhibited when a plasmid expressing recF gene was introduced into E. coli recBCsbcBrecF. The inviability of the plasmid carrying the repeated sequence in E. coli recBCsbcB was discussed by the mechanism of recombination, and the functions of recF, recBC and sbcB were speculated. When E. coli recBC was transformed with pDR1 which was a derivative of pBR322 carrying a directly repeated sequence between which a DNA fragment derived from plasmid R6K with its origin was inserted, the intramolecular recombinant appeared. The recombinant recovered was, however, only the plasmid which had the replication origin of pBR322. The result suggests that pBR322 is compatible with pDR1 but R6K is not. The replication origin of R6K seems to be preferrentially used by pDR1.

[In vitro replication of plasmid pKYM]

The crude extract (fraction II) prepared from E. coli could replicate plasmid pKYM, only when the extract contained the rep protein which was produced by the plasmid and essential for its multiplication in vivo. The intermediate of replication was accumulated when a dideoxynucleotide triphosphate was added to the reaction mixture. By analyzing the intermediate, the initiation site of the deoxyribonucleic acid replication and the direction of replication could be determined. The replication initiated inside the ori region of pKYM and the direction was unidirectional. The analysis also suggested that the synthesis of the lagging strand stopped at almost the same site as the initiation site.

Protein sorting between the outer and inner mitochondrial membranes: submitochondrial localization of cytochrome c1 whose presequence is replaced by the amino-terminal region of a 70 kDa outer membrane protein

The amino-terminal region of a 70 kDa mitochondrial outer membrane protein of yeast and the presequence of cytochrome c1, an inner membrane protein exposed to the intermembrane space, are thought to be responsible for localizing the proteins in their final destinations after synthesis in the cytosol. Gene fusion experiments were used to identify signals that are responsible for protein sorting between the outer and inner mitochondrial membranes. The submitochondrial localization of cytochrome c1 whose presequence was replaced by the amino-terminal region of the 70 kDa mitochondrial outer membrane protein has been investigated. We have also used an in vivo complementation assay to determine whether or not a 70k-cyt c1 fusion protein is functional. Both the first half and all of the presequence of cytochrome c1 can be replaced by the amino-terminal 12 or 29 residues of the 70 kDa protein for transport to the inner membrane and functional assembly into succinate-cytochrome c reductase. However, replacements by the amino-terminal 61 residues of the 70 kDa protein result in exclusive localization of the fusion proteins to the outer membrane, and the fusions cannot be assembled into the enzyme complex. These data indicate that a mitochondrial targeting signal alone is sufficient to direct cytochrome c1 of mature size to the inner membrane.

[Percutaneous transluminal coronary angioplasty for treatment of acute myocardial infarction: comparison with percutaneous transluminal coronary recanalization]

Percutaneous transluminal coronary angioplasty (PTCA) was evaluated as a means of reperfusion of the infarct-related coronary artery, and the results were compared with those of percutaneous transluminal coronary recanalization (PTCR). There were no difference in sex, age, infarct location and time from the onset to start of treatment between 135 patients with evolving acute myocardial infarction treated with PTCA (PTCA group) and 113 patients treated with PTCR alone (PTCR group). Fifty-nine patients in the PTCA group underwent PTCA following PTCR; the remaining 76 patients were without prior PTCR. Successful PTCA, defined as a 20% or more reduction in percent luminal stenosis diameter, was achieved in 123 (90%) of the 135 patients in the PTCA group. The reperfusion rate was 93% in the PTCA group and 77% in the PTCR group (p less than 0.01). Residual stenosis immediately after the treatment was 30 +/- 13% in the PTCA group and 70 +/- 16% in the PTCR group (p less than 0.01). In the PTCA group, three cases developed serious complications which were associated with angioplasty: coronary perforation, side branch occlusion resulting in cardiogenic shock and exacerbation of cardiogenic shock. The latter two patients died, however, there was no difference in hospital mortality rate: 6% in the PTCA group versus 11% in the PTCR group. At follow-up angiography performed four weeks after admission, reocclusion of the successfully recanalized arteries was observed in 3% of the PTCA group and in 14% of the PTCR group (p less than 0.01). Regional wall motion was evaluated by left ventriculography using a wall motion score system which consisted of six grades; from normal counted as 0, to dyskinesis counted as 5. There was no difference in the wall motion score between the successful PTCA group and the successful PTCR group (2.6 +/- 1.4 versus 2.8 +/- 1.4), but the scores of both groups were better than those of the non-recanalized group (3.4 +/- 1.0: p less than 0.01). In conclusion, PTCA and PTCR have the same effect on hospital mortality rate and regional wall motion, but PTCA has a higher reperfusion rate and a lower reocclusion rate than does PTCR. Although PTCA has a potential disadvantage inducing serious complications, it appears to be a useful treatment for acute myocardial infarction.

[Coronary arteriographic findings in the patients with atrial septal defect and pulmonary hypertension (ASD + PH)--compression of left main coronary artery by pulmonary trunk]

The characteristic narrowing of left main coronary artery (LMCA) was found in 44% of patients (pts) with atrial septal defect and pulmonary hypertension (ASD + PH). The cause of the narrowing is thought to be the compression by pulmonary trunk (PT). Cardiac catheterization and coronary arteriography (CAG) were performed in 38 pts with ASD ranging in age from 15 to 62 years. We defined abnormal narrowing as 50% or more stenosis of AHA classification. Sixteen pts (42%) had PH, and of these pts 7 show the abnormal narrowing of LMCA. (18% of all pts with ASD, 44% of pts with ASD + PH). They had no signs of syphilis or aortitis. Of the pts with PH, those with abnormal LMCA revealed higher pulmonary artery mean pressure than those with normal LMCA (43.6 +/- 17.3 and 27.1 +/- 5.5 mmHg respectively. p less than 0.01). Other parts of coronary arteries are intact in all pts. These findings suggest that the LMCA abnormality relates to PH. In all cases with LMCA abnormality the narrowing revealed some special features indicate the cause of narrowing is compression. First, the most severe part of narrowing was the coronary ostium, and severity reduced gradually as distal LMCA. Second, the narrowing was estimated most severely in the view of LAO 20, but almost normal in the view of RAO 30. This finding suggests the narrowing is ellipsoid. Third, the shape of LMCA changed in the different phase of cardiac cycle. In the systole, the cranial border of LMCA was convex, but in the diastole it was concave. This indicates LMCA was soft and compressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection and identification of the plant lignans lariciresinol, isolariciresinol and secoisolariciresinol in human urine

The mammalian lignans enterolactone and enterodiol are regular constituents of human urine and are excreted daily in mumol amounts. They are produced by metabolic action of intestinal bacteria from natural plant lignan precursors which are constituents of various food plants. However, natural plant lignans seem to occur very seldom in detectable amounts in human urine. The present investigation shows that only in 5% of the 150 diphenolic fractions extracted from the urine of women plant lignans other than the previously identified matairesinol could be found. The lignans lariciresinol, isolariciresinol and secoisolariciresinol were identified for the first time by comparison of their GC characteristics and mass spectra with the corresponding results of authentic synthesized reference compounds. Secoisolariciresinol is one natural precursor of the mammalian lignan enterodiol. Of the two other plant lignans, no animal or human metabolic products are known. The occurrence of chemically unchanged plant lignans in some cases in human urine could be a result of an insufficient metabolic capacity of intestinal bacteria, resulting in a decreased detoxification of phenolic plant products.

Aspartate aminotransferase from Panicum maximum Jacq. var. trichoglume Eyles, a C4 plant: purification, molecular properties, and preparation of antibody

Extracts of the leaf tissue of Panicum maximum Jacq. var. trichoglume Eyles (a phosphoenolpyruvate carboxykinase type of C4 plant) were examined and at least two isoforms of aspartate aminotransferase (EC 2.6.1.1), with different electrophoretic mobilities, were detected. The predominant isoform was purified to homogeneity from mesophyll cells. The purification procedure included fractionation with ammonium sulfate followed by chromatography on diethylaminoethyl-cellulose, Sephacryl S-300, and hydroxyapatite. The purified enzyme had specific activities of 182 and 165 mumol/min/mg protein, measured in terms of the synthesis of oxaloacetate and aspartate, respectively, at pH 8.0. The enzyme, with an apparent molecular size of 100 kDa, appears to be a dimer of a single polypeptide with a molecular size of 42 kDa. Mono specific polyclonal antibodies were raised against the 42-kDa polypeptide. Only a single stained band was detected in extracts of whole leaves by immunoblot analysis with this antibody after two-dimensional polyacrylamide electrophoresis. Furthermore, no difference in mobility was observed between the enzymes extracted from mesophyll and bundle sheath cells on native polyacrylamide gels. These findings are discussed in relation to the other isoform in the leaves of this species.

Localization of ferredoxin isoproteins in mesophyll and bundle sheath cells in maize leaf

Four ferredoxin isoproteins were identified in the C(4) plant Zea mays L. by analysis of extracts from leaves, mesocotyls, and roots of the young seedlings. The relative amounts of the isoproteins isolated from the photosynthetic and nonphotosynthetic organs were different. All the isoproteins were present in the leaves of green and etiolated plants, whereas two out of the four isoproteins were not detected in the roots or in the mesocotyls. During the greening of etiolated seedlings, the level of the two isoproteins unique to the leaf increased markedly. Analysis of the cellular and subcellular distribution of the two major leaf isoproteins showed that one isoprotein was present in the chloroplasts of both mesophyll and bundle sheath cells, whereas the other was only found in the chloroplasts of bundle sheath cells. This is the first report of the cell-specific expression of ferredoxin isoproteins in the leaves of a C(4) plant.

Flaviviruses can mediate fusion from without in Aedes albopictus mosquito cell cultures

Flavivirus-induced polykaryocytes were detected in monolayers of Aedes albopictus (clone C6/36) mosquito cells as early as 20 min after adsorbing virus to these cells. A high multiplicity of infection with dengue (DEN)-1, 2, 3, 4, Japanese encephalitis, and yellow fever viruses was required to demonstrate fusion from without (FFWO) with these flaviviruses. Optimal conditions for FFWO included exposure of adsorbed virus to pH 6.0 and an incubation temperature of 39 degrees C. DEN-2 monoclonal antibodies to the envelope E glycoprotein inhibited cell fusion, whereas monoclonal antibodies to the prM and NS1 proteins did not inhibit cell fusion. These results indicate that flaviviruses cause FFWO soon after adsorption to C6/36 mosquito cells and the process is most likely mediated by the virion envelope E glycoprotein.

Precise determination of the mitochondrial import signal contained in a 70 kDa protein of yeast mitochondrial outer membrane

A major 70 kDa protein of the yeast mitochondrial outer membrane is coded by a nuclear gene, synthesized on cytoplasmic ribosomes, and transported to the mitochondrial outer membrane. In order to investigate in detail the information necessary for localizing the 70 kDa protein at the outer membrane, we have examined the intracellular and intramitochondrial location of fusion proteins which consist of various lengths of the amino-terminal region of the 70 kDa protein with an enzymatically active beta-galactosidase. The results indicate that the extreme amino-terminal 12 amino acids of the 70 kDa protein function as a targeting sequence, whereas the subsequent uncharged region (up to residue 29) is necessary for "stop-transfer" and "anchoring" functions. Moreover, we have found that a fusion protein which contained the amino-terminal 19 amino acids of the 70 kDa protein is localized on the outer membrane as well as in the matrix space. Changes in the dual localization of this fusion protein accompanied its overproduction or expression in a respiration-deficient yeast mutant.

Flavivirus entry into cultured mosquito cells and human peripheral blood monocytes

The entry modes of Japanese encephalitis (JE) and dengue-2 (DEN-2) viruses into C6/36 mosquito cells and of DEN-2 virus into human peripheral blood monocytes in vitro were studied. Inoculation of either JE or DEN-2 virions into C6/36 cells resulted in direct penetration of the virions into the cytoplasm at the cell surface in 3 stages. At stage 1, virions attached to the plasma membrane of host cells by their envelope spikes; at stage 2, the virion envelopes approximated to and eventually overlapped the host plasma membrane, and in the process the plasma membrane at the attachment sites dissolved; and, at stage 3, virions penetrated into the cytoplasm through the plasma-membrane disruptions created at the adsorption sites. Virions themselves apparently disintegrated at or near the penetration sites, for no virions were seen in the deeper cytoplasm. Coated pits did not form at the virion attachment sites, and virion-containing vesicles were not found in the cytoplasm. In the entry of DEN-2 virus into human peripheral blood monocytes, virions were found, adsorbed onto the external surface of the plasma membrane and attached to the luminal surface of macropinocytic vacuolar membranes. The latter apparently occurred as the result of ruffling and macropinocytic activities of the cells. At both sites virions penetrated into the cytoplasm through the plasma or vacuolar membrane in the same manner as they did through the plasma membrane of C6/36 cells. No evidence of viral entry by receptor-mediated endocytosis was observed. Implications of the entry mode of the mosquito cell-generated DEN-2 virus into human peripheral blood monocytes to an early process of natural, mosquito-transmitted infection is discussed.

Transcription of a region downstream from lambda ori is required for replication of plasmids derived from coliphage lambda

DNA replication of lambda phage depends on transcriptional activation at or around the lambda ori region by RNA polymerase. To elucidate the function of the transcriptional activation, we constructed several plasmids carrying lambda ori and lacP, whose relative locations and directions were different from each other, and studied replication activity of these recombinant plasmids. Transcription in a region immediately downstream from lambda ori, but not in the lambda ori region, was found to be essential for plasmid replication. Transcription proceeding over a certain minimal length was required and only rightward-directed transcription was effective for the activation.

A comparative study of entry modes into C6/36 cells by Semliki Forest and Japanese encephalitis viruses

The entry modes of Semliki Forest virus and Japanese encephalitis virus into C6/36 cells were compared by electron microscopic observation. At physiological pH, the two viruses showed characteristically different entry modes. Following attachment to the plasma membrane, many SF virions appeared within plasma membrane invaginations and cytoplasmic vesicles; on the other hand, JE virions remained to be found exclusively at the cell surface, with no virions appearing within cytoplasmic vesicles. Electron microscopic observation, therefore, indicated that SF virus entered C6/36 cells by receptor-mediated endocytosis, while JE virus penetrated the cells at the surface and disintegrated at or near the adsorption sites. At pH 5.8, SF virus also entered C6/36 cells by direct penetration at the cell surface. On the basis of the present and other findings, the following working hypotheses are presented for future investigations: (a) at physiological pH, the fusion protein of SF virus is in an inactive state and needs to be activated by acidic pH within the endosome in order to act on the host-cell membrane, but that of JE virus is in an active state and is capable of dissolving the host plasma membrane at the cell surface immediately after the attachment; (b) the states of viral fusion proteins (inactive or active) at the time of viral attachment to the cell surface determine which of the two entry modes these viruses follow.

Sparsomycin analogs. VI. Synthesis and antitumor activity of octylsparsomycin analogs

Five sparsomycin analogs (9-13) were prepared and examined for their ability to inhibit deoxyribonucleic acid (DNA) synthesis in L5178Y lymphoma cells. All of the compounds showed significant activity in the DNA synthesis assay. The compounds having Rc configuration exhibited almost the same activities independently of the configuration at the sulfoxide sulfur atom. Among the Sc isomers, the Rs configuration was advantageous for the appearance of activity.

[Factors affecting the setting time of zinc oxide-eugenol impression materials--the influence of humidity and temperature to the reaction velocity]

Zinc oxide-eugenol paste are widely used in clinical dentistry, principally for impression of non-undercut edentulous ridges, or bite taking materials. However it has been realized by those who use these paste that different products, direction for mixing, or different conditions for mixing, have different characteristics. An experiment have been made to observe the influence of different conditions for mixing to the setting time. Zinc oxide-eugenol impression pastes were mixed in accordance with the manufacturer's instruction when supplied. The condition for mixing was at temperature of 15 +/- 1, 20 +/- 1, 25 +/- 1, 30 +/- 1 degrees C and at humidity of 40 +/- 5, 70 +/- 5, 90 +/- 5%. The setting time (a initial setting time, a final setting time) was defined in the A.D.A. specification No. 16. The following results were obtained. 1. A higher temperature and humidity shortened the initial setting time of all paste. 2. A higher temperature and humidity shortened slightly the time interval between a initial and a final setting time of all paste. 3. In clinical use, sample C is better than other ones, so that a setting time of the sample is property for impression making.

[Bactericidal action of lomefloxacin a new pyridonecarboxylic acid derivative]

Lomefloxacin (NY-198) [(+/-)-1-ethyl-6,8-difluoro-1,4-dihydro-7-(3-methyl-1-piperazinyl)-4-oxo -3- quinolinecarboxylic acid hydrochloride] strongly inhibited the growths of not only Gram-negative Escherichia coli but Gram-positive Staphylococcus aureus. In vivo and in vitro experiments showed deoxyribonucleic acid (DNA) synthesis was specifically inhibited by this drug in E. coli.

Identification of the phyto-oestrogen 3',7-dihydroxyisoflavan, an isomer of equol, in human urine and cow's milk

The isoflavonoid diphenol 3',7-dihydroxyisoflavan, an isomer of the known compound equol (4',7-dihydroxyisoflavan), has been identified in human urine and in cow's milk. The compound was isolated as the glucuronide, purified by column chromatography and identified after hydrolysis to the aglycon. The trimethylsilyl ether derivative was characterized by comparison of its mass spectrum and chromatographic properties with those of synthesized silylated isomers of equol.

Tertiary structure of Bacillus thermoproteolyticus [4Fe-4S] ferredoxin. Evolutionary implications for bacterial ferredoxins

The structure of a low-potential [4Fe-4S] ferredoxin from Bacillus thermoproteolyticus has been solved using anomalous scattering data from iron atoms in the diffraction data of native crystals and refined partially to a crystallographic R-factor of 0.33, with 2.3 A (1 A = 0.1 nm) resolution data. The least-squares refinement based on the Bijvoet differences has determined that the four iron atoms in the cluster are an equal distance, approximately 2.8 A, apart. The NH ... S hydrogen bonds between polypeptide nitrogen atoms, and both cysteine and inorganic sulfur atoms, are present, as in ferrodoxin from Peptococcus aerogenes. The polypeptide chain of the B. thermoproteolyticus ferredoxin has a fold closely similar to that of 2[4Fe-4S] ferredoxin from P. aerogenes. The structural correspondence indicates strongly that both types of ferredoxin evolved from a common ancestor. The second cluster-binding region in P. aerogenes ferredoxin corresponds to the alpha-helix in B. thermoproteolyticus ferredoxin. The secondary-structure predictions strongly suggest that the alpha-helix is generally present in the monocluster-type ferredoxins. The conformational change to alpha-helix, insertions of a loop and a protrusion, as well as the absence of the second cluster in B. thermoproteolyticus ferredoxin, result in the lack of 2-fold symmetry present in P. aerogenes ferredoxin. So, the track of gene duplication is no longer detectable in the tertiary structure alone. The evolutionary events that may have occurred in the ferredoxins with the [4Fe-4S] cluster are discussed.

Maturation process of Japanese encephalitis virus in cultured mosquito cells in vitro and mouse brain cells in vivo

The maturation process of Japanese encephalitis (JE) virus in C6/36 cells in vitro and in mouse brain cells in vivo was studied by electron microscopy. In the C6/36 cell infection, 500 to 2250 virions per cell were released into the medium during the period of study; yet, no virus budding process was observed at the host cell membranes. JE virions at various maturation stages appeared within the cisternae of rough endoplasmic reticulum (RER) of infected cells at 24 hours p.i.; and, although C6/36 cells did not show a well-developed Golgi apparatus, the virions appeared to be carried to the cell surface within host-cell secretory vesicles for extracellular release as early as 24 hours p.i. The occurrence of a secretory-type intracellular transport of maturing JE virus particles was well recognizable in brain cells of infected mice, in which JE virus particles were found almost exclusively in the cisternae of RER, in the Golgi apparatus, and in various vesicles, including coated vesicles, in the vicinity of the Golgi apparatus. Our previous study of dengue-2 virus morphogenesis and our present study of JE virus morphogenesis differed substantially at various stages of maturation. Possible mechanisms which explain these differences were discussed.

An electron and immunoelectron microscopic study of dengue-2 virus infection of cultured mosquito cells: maturation events

The maturation process of dengue-2 virus in C6/36 mosquito cells was studied by electron microscopy at 12, 16, 24, 48, and 78 hours postinoculation (p.i.) and by immunoelectron microscopy at 48 and 78 hours p.i. Maturing virions appeared within cytoplasmic vacuoles and on the surface of infected cells from 24 hours p.i. onward in close topographical relationship to the dense particles that occurred concurrently in the cytoplasm. The dense particles measured 25 to 35 nm in diameter; the mature virions measured 50 to 55 nm in diameter, with a dense core measuring 30 to 35 nm in diameter covered by a 10 nm-thick membrane envelope. The morphological observations indicated that the dense particles were dengue nucleocapsids assembled in the cytoplasm and that they apparently budded into the vacuolar lumens and the extracellular space at the vacuolar and plasma membranes, acquiring membrane envelopes and becoming mature virions in the process. The virions that budded into the vacuolar lumens were released extracellularly by exocytosis. In the samples tested with dengue-2 polyclonal antibodies, intense immunostaining occurred at the sites of virus budding on the cell surface; host cell membrane and cytoplasm adjacent to the budding virions stained less intensely. In the samples tested with a dengue-2 monoclonal antibody specific for the envelope glycoprotein, budding virions stained rather exclusively, with no staining occurring in adjacent host membrane or cytoplasm.