Nucleotide sequences of the helper component-proteinase genes of aphid transmissible and non-transmissible isolates of turnip mosaic virus

We have compared nucleotide sequences of the helper component-proteinase (HC-Pro) coding region of aphid transmissible (isolate 1) and non-transmissible (isolate 31) isolates of turnip mosaic virus (TuMV). HC-Pro coding regions of both TuMV isolates 1 and 31 were 1,374 nucleotide long. The nucleotide sequence homology between these isolates was 93.5%, with 89 nucleotides substitution. The nucleotides of HC-Pro regions of two isolates of TuMV genomes encoded 458 amino acids of M(r) 51,746 (isolate 1) and M(r) 51,764 (isolate 31). The deduced amino acid sequence homology between these isolates was 98.7% with six different amino acids. These amino acids appeared to regulate the activity of HC-Pro needed for aphid transmissibility of TuMV.

[Development of left atrial thrombus after excellent mitral valvuloplasty for chronic severe mitral regurgitation]

We report two cases with chronic severe mitral regurgitation and atrial fibrillation in whom left atrial thrombus was detected by transesophageal echocardiography after excellent mitral valvuloplasty. The reason why thrombus developed after valvuloplasty is that preoperative severe mitral regurgitation made the left atrial blood less stagnant than it was after surgery. Thus, even when mitral valvuloplasty achieves excellent results in patients with severe chronic mitral regurgitation and atrial fibrillation, anticoagulation and left atrial appendage ligation should also be considered.

Isozyme-specific modules on human aldolase A molecule. Isozyme group-specific sequences 1 and 4 are required for showing characteristics as aldolase A

Vertebrate aldolase molecules bear at least four stretches of isozyme group-specific sequences (referred to as IGS). The IGSs of the type A isozyme are known to endow the aldolase molecules with some characteristics typical of A. In order to locate the type A regions, 4 chimeric enzymes were constructed between human aldolases A and B and 5 mutant enzymes with single or double mutations in the IGS-1 region. Among engineered proteins, the chimeric enzymes bearing the type A IGS-1 to -4 (BABA34-108:306-363) and the IGS-1 and -4 (BABA34-55:306-363) exhibited similarities to isozyme A in many respects. On the other hand, neither chimeric enzyme bearing the type A IGS-1 to -3 (BAB34-108) nor that bearing the IGS-1 alone (BAB34-55) exhibited properties as isozyme A. Four mutant aldolases A (carrying single mutation in the IGS-1 region) maintained the original activity as A. Similarly, the BA306 chimera with the type B-->A substitution at positions 41 and 45 (BA306 N41K:R45S) failed to exhibit the A-like properties although the activities toward Fru-1,6-P2 and Fru-1-P significantly increased. Conclusively, the type A IGS-1, together with the IGS-4, act as indispensable modules in determining the characteristic properties of human aldolase A.

Saponin and sapogenol. XLVII. On the constituents of the roots of Glycyrrhiza uralensis Fischer from northeastern China. (1). Licorice-saponins A3, B2, and C2

From the air-dried root of Glycyrrhiza uralensis, collected in the northeastern part of China, ten new oleanane-type triterpene oligoglycosides were isolated together with glycyrrhizin (1) and several known flavonoids. Among the newly isolated triterpene oligoglycosides, the chemical structures of licorice-saponin A3 (2), licorice-saponin B2 (3), and licorice-saponin C2 (4) have been determined, on the basis of chemical and physicochemical evidence, to be expressed as 30-O-beta-D-glucopyranosylglycyrrhizin, 11-deoxo-glycyrrhizin, and 3-O-[beta-D-glucuronpyranosyl(1-->2)-beta-D-glucuronpyranosyl++ +]oleana- 11,13(18)-dien-30-oic acid, respectively. During the course of these studies, facile conversions from glycyrrhizin (1) to licorice-saponins A3 (2), B2 (3), and C2 (4) have been accomplished.

The etiology of damage to lucerne by the green mirid, Creontiades dilutus (Stal)

Green mirid [Creontiades dilutus (Stsl) (Miridae: HEM)] of all developmental stages was found in lucerne throughout December and January 1989-90 at sites near Adelaide, Australia. In the laboratory, they were unable to complete development when given foliage only, but 65% completed development when provided with flowers, from which they fed preferentially on the developing ovules. Only 25% developed from egg to third instar when cut pods were the sole food source but all survivors completed their development on pods thereafter. The insects were observed to make unsuccessful attempts to feed on spotted alfalfa aphid [Therioaphis trifolii (Monell) f. maculata Aphidae (HEM)]. When fifth instars were caged on entire plants, most of the insects were subsequently found near the tops of the plants. Ten adults caged on a head with 7 pods caused them to turn yellow in 5 days, brown in 6, and withered in 7. An adult caged with 2 flowers for 5 h caused both to drop the standard petal and to abort development within the subsequent 24 h. Feeding frequency of fifth instars when given flower heads ad libitum was estimated at 18 times, for a total of 169 minutes, over a 5-h observational period. The saliva contained a pectin, endopolygalacturonase, and its injection into developing ovules and seeds probably accounts for the etiology of damage. The insects' requirement of lucerne seeds and/or ovules to complete its development, its frequency of feeding, and the abscission of whole flowers due to feeding on the ovules probably accounts for the serious losses of seed production previously reported.

Correlation between HPV positivity and state of the p53 gene in cervical carcinoma cell lines

Human papillomavirus (HPV) infection is clearly associated with cervical carcinomas, yet it is also true that there are cervical carcinomas in which HPV DNA is absent. We examined eight established cell lines derived from cervical carcinomas for the presence of mutations of the p53 antioncogene in relation to the presence of HPV DNA sequences. Of these eight cell lines, seven were positive for HPV DNA and the remaining one was negative for HPV DNA. Single-strand conformation polymorphism analyses revealed a point mutation of the p53 gene in the cell line in which HPV DNA was absent. Sequencing analysis revealed a single-base mutation at codon 273 from CGT to CAT(Arg-->His) and immunocytochemical studies provided evidence that the p53 protein was overexpressed in this cell line. Our observations suggest that the loss of normal p53 gene function may be linked to the oncogenesis of cervical carcinoma.

Genetic predisposing factors in non-insulin dependent diabetes with persistent albuminuria

We designed this study to elucidate a possible involvement of genetic factors which influence the progression of renal dysfunction in patients with non-insulin dependent diabetes mellitus (NIDDM). A total of 328 patients was randomly selected in the Tokai University Hospital. They had been cared for in our hospital as NIDDM for the past five years, until April, 1989. Fifty-six patients with persistent albuminuria, and an equal number of patients without persistent albuminuria were included in this study. No significant differences were observed between the two groups in terms of age, estimated period of illness, blood pressure, body-mass index, HbAlc, blood glucose, total cholesterol, triglyceride level and mean blood pressure. The family histories obtained by questionnaires revealed that there might be some genetic predisposing factors leading to the onset of nephropathy in patients with NIDDM, especially in cases with paternal high blood pressure. It is suggested that paternal hypertension might be related to the development of nephropathy in patients with NIDDM.

Reversible left ventricular dysfunction induced by recurrent ventricular tachycardia

Two cases of transient LV dysfunction associated with VT are described. Both patients had a history of palpitations of several years' duration without symptoms of congestive heart failure. The reason for presentation was an increase in frequency and duration of palpitation. Decreased LV wall motion, observed by 2DE, normalized shortly after treatment of the VT. Diffusely decreased LV wall motion is associated with frequent episodes of VT and may mimic DCM except that signs and symptoms of heart failure are absent.

Enhanced monoamine release in the median preoptic area following reduced extracellular fluid volume in rats

The role of monoaminergic neural inputs to fluid regulatory systems in the median preoptic nucleus (MnPO) was investigated by examination of monoamine metabolism during reduction of systemic extracellular fluid volume in freely moving rats. Extracellular fluid volume was decreased iso-osmotically by subcutaneous polyethylene glycol (PEG), and extracellular noradrenaline (NA), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) were measured using intracerebral microdialysis techniques. PEG treatments significantly increased NA, DA and DOPAC release in the MnPO area. The results suggest that monoaminergic neural systems in the region of the MnPO are important in the control of extracellular fluid balance.

Inhibition by a novel azole antifungal agent with a geranyl group on lanosterol 14 alpha-demethylase of yeast

AFK-108 (1-[2-(2,4-dichlorophenyl)-2-((2E)-3,7-dimethylocta-2,6- dienyloxy)ethyl]-1H-imidazole) is a new imidazole derivative characterized by a geranyl substituent showing strong antifungal activity. Azole antifungal agents are known to be potent inhibitors of lanosterol 14 alpha-demethylase (P450(14)DM) of fungi. The role of the geranyl group of AFK-108 on interaction of AFK-108 with the target was studied by using Saccharomyces cerevisiae P450(14)DM as the model enzyme. AFK-108 and some of its derivatives bound to oxidized P450(14)DM with one-to-one stoichiometry and inhibited the demethylase activity. AFK-108 derivatives having the longer farnesyl or the shorter prenyl group showed lower affinity than AFK-108 for the enzyme. AFK-108 caused 100% inhibition at the equivalent concentration to P450(14)DM in the reaction mixture (0.07 microM), while the farnesyl derivative inhibited the activity by 60% at the same concentration. AFK-108 interfered with the binding of CO to the ferrous P450(14)DM. However, the interfering effect of the prenyl derivative was lower than that of AFK-108. Another AFK-108 derivative having the saturated 3,7-dimethyloctyl group was also a weaker inhibitor than AFK-108. These experiments suggest that the geranyl group of AFK-108 interacts with the substrate binding site of P450(14)DM that recognises the side chain of the substrate. AFK-108 is the first example of an azole derivative interacting with the side chain recognising region of the substrate binding site of P450(14)DM.

Gene structure and multiple mRNA species of Drosophila melanogaster aldolase generating three isozymes with different enzymatic properties

Genomic clones encoding the Drosophila aldolase gene were isolated and the organization of the gene was determined. The protein-coding region spanning nearly 3.5 kb consists of five coding exons (exon 2, 3, 4 alpha, 4 beta, and 4 gamma). The insect exon 2 corresponds to exons 2 to 7 of vertebrate aldolase genes and thus appears to have been formed by the fusion of these 6 exons into a single exon during evolution. The Drosophila aldolase gene is predicted to generate mRNAs for three isozymes (alpha-, beta-, and gamma-types) from the primary transcripts by alternative usage of the final three exons. The reverse transcriptase-PCR assay revealed the occurrence of mRNAs for the three isozymic forms at different developmental stages, and tissue-specific expression was also found to occur in adult flies. In addition to the usual type mRNA species for the alpha-, beta-, and gamma-isozymes, two novel forms of mRNAs, alpha beta- and beta gamma-type mRNAs, were detected tissue-specifically in adult flies, although their functions are unpredictable. The alpha beta-mRNA is an alpha-type mRNA in which exon 4 beta remains unspliced, while the beta gamma-mRNA is a beta-type mRNA with the exon 4 gamma remaining unspliced. Recombinant enzymes expressed in Escherichia coli were all active and exhibited different enzymatic properties.

Inhibition of ionotropic neurotransmitter receptors by antagonists: strategy to estimate the association and the dissociation rate constant of antagonists with very strong affinity to the receptors

Since binding of an agonist to an ionotropic neurotransmitter receptor causes not only channel opening, but also desensitization of the receptor, inhibition of the receptor by the antagonist sometimes becomes very complicated. The transient state kinetics of ligand association and dissociation, and desensitization of the receptor were considered on the basis of the minimal model proposed by Hess' group, and the following possibilities were proposed. 1) When an agonist is simultaneously applied to the receptor with an antagonist whose affinity to the receptor is extremely strong and different from that of the agonist, it is usually impossible to estimate the real inhibition constant exactly from the responses because desensitization of the receptor proceeds before the equilibrium of the ligand binding. Simultaneous addition of the antagonist with strong affinity to the receptor may apparently accelerate inactivation (desensitization) of the receptor. The association rate constant of the antagonist can be estimated by analyses of the rate of the inactivation in the presence and the absence of the antagonist. 2) A preincubated antagonist with a slow dissociation rate constant, i.e., a very effective inhibitor, may cause apparent noncompetitive inhibition of the receptor, since the receptor is desensitized by an agonist as soon as the antagonist dissociates from the receptor and the dissociation of the antagonist from the receptor becomes the rate-determining step. A nicotinic acetylcholine receptor (nAChR) was expressed in Xenopus oocytes by injecting mRNA prepared from Electrophorus electricus electroplax and used for the experiments on inhibition by an antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased monoamine turnover in the subfornical organ area following body fluid depletion

To clarify whether monoaminergic inputs to the subfornical organ (SFO) area participate in fluid regulatory systems, we examined the effects of body fluid depletion on monoamine turnover in the region of the SFO using microdialysis techniques in rats. An iso-osmotic reduction of fluid volume following subcutaneous treatment with polyethylene glycol (PEG) significantly increased dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in the SFO area. 5-hydroxytryptamine (5-HT) in the SFO area could be detected after the PEG treatment, while 5-HT was undetectable before the treatment. The data imply that both dopaminergic and serotonergic systems in the SFO area may be involved in controlling body fluid balance.

Mechanisms for appearance of no-flow areas in tumor microvascular bed

In order to elucidate the mechanism for appearance of no-flow areas (areas where tumor blood flow temporarily cease), we directly observed the process of tumor-induced neovascularization and measured pressure change in a feeding vessel (starting vessel) which supplies blood to the tumor vascular network. Total length of tumor vascular network from one starting vessel increased exponentially as the tumor increased in size exponentially. The pressure of the starting vessel increased from approximately 40 cmH2O to 120 cmH2O with enlargement of the tumor size. As soon as the pressure of the starting vessel reached a plateau, however, there was a rapid increase in low-flow or no-flow areas in places within the tumor. We considered that no-flow areas were produced by the imbalance between the pressure elevation of a starting vessel and the enlargement of the vascular network from that vessel.

Segmental asynergy of the left ventricle in a case of tight aortic stenosis associated with mild ischemic heart disease

Emergency aortic valve replacement with double aorto-coronary bypass surgery was performed to treat severe intractable congestive heart failure in an 82-year-old man. Mild circumflex and left anterior descending artery lesions were present and the pressure gradient across the aortic valve was 80 mmHg despite a low cardiac output. The preoperative anteroseptal akinesia seen by two-dimensional echocardiography was normalized after surgery. Thus, even in patients with segmental left ventricular dysfunction, tight aortic stenosis might be present when concomitant mild ischemic heart disease is present.

Altered structure and expression of the p53 gene in human neuroepithelial tumors

The p53 gene, located on chromosome 17p13.1, may be important in the pathogenesis of human neuroepithelial tumors, because it is a tumor suppressor gene and genetic alteration is essential for certain human cells to acquire the neoplastic phenotype. The structure and expression of the p53 gene were investigated in cultured human glioma cells and biopsied specimens of neuroepithelial tumors. Immunocytochemical examination of p53 gene expression revealed positive nuclear staining in six of seven glioma cell lines tested. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis demonstrated unequivocal heterogeneity of migration rate in p53 bands. Pulse-chase analysis clearly showed an increased half-life of p53 in cultured human glioma cells. These abnormalities are presumably due to genetic alterations in the p53 gene. Nucleotide substitutions in exon 5, 7, or 8 of the p53 gene could be detected by polymerase chain reaction-single strand conformational polymorphic analysis in four of seven (57%) human glioma cell lines, and nine of 29 (31%) biopsied specimens of neuroepithelial tumors examined. The present results indicate that genetic alterations in the p53 gene are responsible for the tumorigenesis of at least some human neuroepithelial tumors.

Actin-actin contact: inhibition of actin-polymerization by subdomain 4 peptide fragments

F-Actin was digested with alpha-chymotrypsin in 6 M urea, and two peptide fragments from subdomain 4 of actin molecule [Kabsch, W., Mannherz, H.G., Suck, D., Pai, E.F., & Holmes K.C. (1990) Nature 347, 37-44] were purified by reverse-phase HPLC and Sephadex G-50 gel filtration. The peptide fragments were identified as segments from Arg-177 to Tyr-198 (2.6-kDa peptide) and from Ser-199 to Tyr-279 (9.1-kDa peptide). Their effects on actin polymerization induced by 50 or 100 mM KCl were studied by measuring the increase in viscosity by the falling ball method. The 2.6-kDa peptide decreased the rate of actin polymerization and increased the critical concentration for the polymerization. Based on the atomic model of the actin filament [Holmes, K.C., Popp, D., Gebhard, W., & Kabsch, W. (1990) Nature 347, 44-49], the peptide is presumed to bind to the barbed end of the actin filament and inhibit the polymerization. By assuming that the peptide affected the rate of association of the actin monomer to the end of the actin filament, well-fitting curves for the polymerization kinetics were calculated. Computer-assisted results indicated that the dissociation constant of the 2.6-kDa peptide for F-actin is 200 to 260 microM. In contrast, the 9.1-kDa peptide only slightly inhibited actin polymerization. These results suggest that the actin-actin interface in the region between Arg-177 and Tyr-198 has a stronger interaction than those between Ser-199 and Tyr-279. The amino acid sequence L-T-D-Y-L present in the 2.6-kDa segment is homologous to a common sequence in the F-actin capping domain of various actin-binding proteins.

In vivo study of flow pattern at human carotid bifurcation with regard to aneurysm development

In order to investigate the developmental mechanism of cerebral aneurysms, the in vivo flow pattern around human cervical carotid bifurcations was studied by flow visualization using digital subtraction angiography with an isotonic contrast medium. The blood stream containing the medium impinged on the apex, then proceeded along the walls of the branches. After opacification of the whole lumen around the apex, most of the medium was carried away, while some remained for a few seconds at the carotid sinus. In the internal carotid artery, the blood struck the wall at an oblique angle near the tops of the arterial curvatures. In cases with atheromatous plaque or kinking of the branch, the blood passed through the stenosed segment and moved upstream, indicating turbulence. The study suggests that haemodynamic forces around the apex consist mainly of impingement on the apex and shear stress to the wall at and around the apex. In branches, high shear stress seems to exist. It might be possible that high shear stress causes degenerative changes in the endothelial layer, initiating the formation of saccular and fusiform cerebral aneurysms.

Indonesian medicinal plants. II. Chemical structures of Pongapinones A and B, two new phenylpropanoids from the bark of Pongamia pinnata (Papilionaceae)

Two new phenylpropanoids named pongapinone A (1) and pongapinone B (2) were isolated from the bark of Pongamia pinnata (Papilionaceae), an Indonesian medicinal plant, and their chemical structures have been elucidated on the basis of their physicochemical properties. Pongapinone A (1) was found to inhibit interleukin-1 production.

Effects of dihydroergotoxine on central cholinergic neuronal systems and discrimination learning test in aged rats

We evaluated changes in the cholinergic neuronal system and learning ability with aging. Choline acetyltransferase (ChAT) activity, a presynaptic index of the cholinergic system, was decreased in the cerebral cortex, hippocampus, striatum, and hypothalamus in the brain of aged rats compared with young adults. Muscarinic cholinergic binding sites (receptors, MCR), a postsynaptic index of the cholinergic system, were markedly decreased in all areas of the brain. However, intraperitoneal injection of 1 mg/kg of dihydroergotoxine (DHET) for 14 days normalized both ChAT and MCR in the cerebral cortex and hippocampus. In the striatum, ChAT was normalized, but MCR did not recover. Aged rats showed marked learning impairment in a 30-day operant type brightness discrimination learning test. Daily DHET administration restored the discrimination ability in the aged rats to nearly the young adult level. DHET had no effects on central cholinergic indices or learning test results in young adult rats. These findings suggest that learning is impaired in aged rats due to impairment in the central cholinergic neuronal system, and that DHET normalizes the decreased function in this system, restoring the learning ability.

Systemic and cutaneous plasmacytosis with multiple skin lesions and polyclonal hypergammaglobulinaemia: significant serum interleukin-6 levels

We report two patients who developed benign plasmacytosis with multiple skin lesions. The cases were characterized by hyperplasia of mature plasma cells, and polyclonal hypergammaglobulinaemia. One patient had hyperplasia of mature plasma cells not only in the skin, but also extensively in lymph nodes and the retroperitoneal areas around the ureters. The other had plasma cell hyperplasia limited to the skin. Extensive investigations failed to reveal any clinical or laboratory evidence suggesting the presence of any underlying disease accompanying the hypergammaglobulinaemia and/or plasma cell proliferation, such as chronic infectious disease, collagen disease or other chronic inflammatory disorder. Clinically and histologically, the first patient showed features compatible with a diagnosis of systemic plasmacytosis and the second with a diagnosis of cutaneous plasmacytosis. Significant serum interleukin-6 (IL-6) levels were detected in both patients, suggesting that IL-6 may be involved in the pathogenesis of these conditions.