[Clinical features and advanced progress of secondary BPPV]

BPPV is a disease provoked by abrupt head movements, results in short paroxysmal vertigo or nystagmus. These patients often can accurately describe the dizziness happened when they head move suddenly, especially when looking upward, turning over in bed, lying down, or bending over. BPPV is divided into idiopathic BPPV and secondary BPPV, in most cases. The underlying cause cannot be determined, which is called idiopathic; however, in 30% patients, BPPV may be attributed to a specific cause and is termed secondary BPPV. We reviewed the pathogenesis, mechanisms, clinical features, treatment and the latest progress of secondary BPPV.

Active yet extremely durable Co3O4 spheroids of different texture without/with Au deposition for CO oxidation

Co₃O₄ spheroids of different texture without/with Au deposition were highly active yet very durable at 60–90 °C for CO oxidation. The calcined Co₃O₄-based catalysts and the yolk–shell type one were even more durable. The catalysts encountered obvious enhancement in CO oxidation activity via in situ pretreatment.

Steroidal saponins from Dioscorea panthaica and their cytotoxic activity

A new steroidal saponin, dioscoreside E (1), and a known compound, protodioscin (2), were isolated from an ethanol extract of the rhizomes of Dioscorea panthaica. The structure of 1 was established as 3-O-[bis-alpha-L-rhamnopyranosyl-(1 --> 2 and 1 --> 4)-beta-D-glucopyranosyl]-26-O-beta-D-glucopyranosyl-20(R)-methoxy-25(R)-furosta-5,22(23)-diene-3beta,26-diol, on the basis of spectral and chemical evidence. Compounds 1 and 2 showed cytotoxic activity against a panel of tumor cell lines.

Two new steroidal saponins from the rhizomes of Dioscorea panthaica and their cytotoxic activity

Two new steroidal saponins, dioscoresides C (1) and D (2), along with a new natural product, pregnadienolone 3-O-beta-gracillimatriose (3), and two known compounds, pregnadienolone 3-O-beta-chacotrioside (4) and pseudoprotodioscin (5), were isolated from the rhizomes of Dioscorea panthaica Prain et Burkill. On the basis of extensive NMR studies and chemical evidence, dioscoresides C and D were determined to be 26-O-beta-D-glucopyranosyl-3 beta,26-dihydroxy-23(S)-methoxy-25(R)-furosta-5,20(22)-dien-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside and 26-O-beta-D-glucopyranosyl-3 beta,26-dihydroxy-20,22-seco-25(R)-furosta-5-en-20,22-dine-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1--> 4)]-beta-D-glucopyranoside. These compounds showed mild cytotoxicity against the cancer cell lines, A375, L929, and HeLa, in a dose-dependent manner.

Differential mercury volatilization by tobacco organs expressing a modified bacterial merA gene

Mercury pollution is a major environmental problem accompanying industrial activities. Most of the mercury released ends up and retained in the soil as complexes of the toxic ionic mercury (Hg2+), which then can be converted by microbes into the even more toxic methylmercury which tends to bioaccumulate. Mercury detoxification of the soil can also occur by microbes converting the ionic mercury into the least toxic metallic mercury (Hg0) form, which then evaporates. The remediation potential of transgenic plants carrying the MerA gene from E. coli encoding mercuric ion reductase could be evaluated. A modified version of the gene, optimized for plant codon preferences (merApe9, Rugh et al. 1996), was introduced into tobacco by Agrobacterium-mediated leaf disk transformation. Transgenic seeds were resistant to HgCl2 at 50 microM, and some of them (10-20% ) could germinate on media containing as much as 350 microM HgCl2, while the control plants were fully inhibited or died on 50 microM HgCl2. The rate of elemental mercury evolution from Hg2+ (added as HgCl2) was 5-8 times higher for transgenic plants than the control. Mercury volatilization by isolated organs standardized for fresh weight was higher (up to 5 times) in the roots than in shoots or the leaves. The data suggest that it is the root system of the transgenic plants that volatilizes most of the reduced mercury (Hg0). It also suggests that much of the mercury need not enter the vascular system to be transported to the leaves for volatilization. Transgenic plants with the merApe9 gene may be used to mercury detoxification for environmental improvement in mercury-contaminated regions more efficiently than it had been predicted based on data on volatilization of whole plants via the upper parts only (Rugh et al. 1996).

A new triterpenoidal saponin from Ixeris sonchifolia and its cytotoxic activity

A new triterpenoidal saponin, echinocystic acid 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranoside (1), was isolated from Ixeris sonchifolia. Its structure was elucidated on the basis of full spectral data analysis and chemical methods. The cytotoxic activity of compound 1 was evaluated using the tumor cell lines of A375, Hela, and L929 in vitro.

Conformation and rigidity of DNA microcircles containing waf1 response element for p53 regulatory protein

The tumor-suppressor activity of p53 is closely related to its DNA-binding properties. It binds a number of DNA response-elements and it is likely that these share a common structural feature. Here, we present a new, general method to determine the absolute twist of flexible DNA promoter sequences based on direct imaging of the topology of microcircles containing the sequences. We have used magnetically driven dynamic force microscopy ("MacMode" AFM) to observe, in solution, the conformation of 168 base-pair DNA microcircles, each containing four equally spaced copies of the waf1/cip1/p21 p53 response-element. Analysis of the images showed that the microcircles are markedly puckered with a small excess of negatively writhed molecules. The average measured values of writhe are 0.109+/-0.013 (for 60 positively writhed molecules) and -0.098+/-0.011 (for 65 negatively writhed molecules). These values lead directly to a difference in linking number for the positively and negatively writhed molecules prior to ligation, from which we derive a twist mismatch of 178 degrees (overtwist). This is 44.5 degrees for each 42-mer precursor containing a single waf1/cip1/p21 p53 response-element, in good agreement with the range of values deduced by indirect biochemical techniques. The two values of writhe may also be used to determine the ratio of the bending (B) to twisting (C) rigidity, yielding B/C=0.23. This is about one-third of the value for long, random-sequence DNA, suggesting that the waf1/cip1/p21 p53 response-element is extremely flexible, a result that is also consistent with indirect biochemical experiments. These results support the idea, proposed by us earlier, that torsional stress may play a role in the regulation of p53 binding through modulation of twist at the binding site.

Three new triterpenoids from Fuscoporia obliqua

Three new lanostane triterpenoids, fuscoporianol A (1), B (2), and C (3) were isolated from the petroleum ether extracts of Fuscoporia obliqua and their structures have been determined on the basis of chemical, spectroscopic methods and X-ray crystallographic analysis as 25-methoxy-21, 22-cyclolanosta-8-ene-3beta, 21alpha-diol(1), 3beta, 22alpha-dihydroxy-lanosta-8, 23E-diene-25-peroxide (2), 3beta, 22alpha, 25-trihydroxy-lanosta-8, 23E-diene (3).

A new sesquiterpene lactone glucoside from Ixeris sonchifolia

A new sesquiterpene lactone glucoside, Ixerin Z1 (1), was isolated from the whole plants of Ixeris sonchifolia (Bge.) Hance, along with 15 known compounds. The structure of 1 was elucidated as 1(10),3,11(13)-guaiatriene-12,6-olide-2-one-3-O-[6'-(p-hydroxyphenylacetyl)]-glucopyranoside by spectroscopic methods including 2D-NMR techniques.

Feigrisolides A, B, C and D, new lactones with antibacterial activities from Streptomyces griseus

Four new lactone compounds, named feigrisolides A to D (1 to 4), have been isolated from Streptomyces griseus. The chemical structures were determined by detail analysis of their spectroscopic data and chemical transformations. Structurally, the feigrisolides A (1) and B (2) are hepta-lactones, feigrisolide C (3) and D (4) are 16-membered macrodiolides. Biological studies showed that feigrisolide B (2) exhibited strong antibacterial, as well as medium cyctotoxic, and antiviral activities. Feigrisolides A (1), C (3) and D (4) are medium inhibitors of 3alpha-hydroxysteroid-dehydrogenase (3alpha-HSD) inhibiting activity.

New 1-O-acyl alpha-L-rhamnopyranosides and rhamnosylated lactones from Streptomyces sp., inhibitors of 3 alpha-hydroxysteroid-dehydrogenase (3alpha-HSD)

Chemical screening with extracts of Streptomyces sp. (strain GT 61150) resulted in the detection, isolation, and structure elucidation of two new acyl alpha-L-rhamnopyranosides (1 and 2) and three new rhamnosyllactones A, B1 and B2 (3 approximately 5). Rhamnosyllactones B1 and B2 were obtained as a 5:1 mixture. The structures were confirmed by spectroscopic analysis, especially 2D-NMR techniques. The rhamnosyltransferase of our strain is able to connect the sugar moiety to heteroaromatic carboxylic acids and enols. The metabolites 1 and 4/5 as well as previously reported acylrhamnosides 6 approximately 11 inhibit the enzyme 3alpha-hydroxysteroid-dehydrogenase (3alpha-HSD).

Conformational transition in DNA on a cold surface

The contour length of DNA fragments, deposited and imaged on mica under buffer, was measured as a function of deposition temperature. Extended DNA molecules (on Ni- and silane-treated surfaces) contract rapidly with falling temperature, approaching the contour length of A-DNA at 2 degrees C. The contraction is not unique to a specific sequence and does not occur in solution at 2 degrees C or on a surface at 25 degrees C, indicating that it arises from a combination of low temperature and surface contact. It is probably a consequence of reduced water activity at a cold surface.

Two new iridoids from hedyotis chrysotricha

Two new iridoid glycosides, asperulosidic acid ethyl ester (1) and 6'-acetyl deacetylasperuloside (2), were isolated from Hedyotis chrysotricha (Palib) Merr. Their structures were elucidated by spectroscopic means.

New guaianolides from Artemisia selengensis

A new guaianolide artselenin (1) and a new dimeric guaianolide artselenoid (2), along with 10 known compounds, were isolated from the aerial parts of Artemisia selengensis. Their structures were elucidated by spectroscopic methods. Two-dimensional NMR techniques were used to make complete assignments for the 1H- and 13C-NMR chemical shifts of the two new guaianolides.

[Chemical investigation of genus Hedyotis. II. Isolation and identification of iridoids from Hedyotis chrysotricha]

Many species of genus Hedyotis (Rubiaceae) were used as folk medicine for treatment of cold, inflammation, cancer and etc. in China. The alcoholic extract of the whole plant of H. chrysotricha showed good hepatoprotective effects. From the alcoholic extract ten iridoids were isolated and their structures were elucidated as: asperuloside (1), scandoside methyl ester (2), asperulosidic acid (3), deacetyl asperulosidic acid (4), loganin (5), deacetyl asperuloside (6), acetyl scandoside methyl ester (7), 6 beta-hydroxy-genipin (8) and two new compounds named hedyoside (9) and 6'-acetylasperuloside (10), by means of chemical and spectral methods.

New Indole Alkaloids from Amsonia sinensis

Fourteen indole alkaloids, Delta (14)-isoeburnamine ( 1), amsosinine ( 2), tabersonine, vincadifformine, lochnericine, tetrahydroalstonine, beta-yohimbine, isoeburnamine, minovicinine, picrinine, strictamine, rhazimine, vincanidine, and decarbomethoxytetrahydrosecamine, were isolated from AMSONIA SINENSIS. Delta (14)-isoeburnamine ( 1) and amsosinine ( 2) are new compounds, their structures have been established by spectral and chemical methods. A known sterol glycoside, daucosterol, has also been obtained. The structures of compounds 1 and 2 were finally confirmed by X-ray diffraction of single crystals.

Two Novel Protoilludane Norsesquiterpenoid Esters, Armillasin and Armillatin, from Armillaria mellea

Two novel protoilludane norsesquiterpenoid esters, named armillasin and armillatin, have been isolated from the artificially cultured mycelium of ARMILLARIA MELLEA (Tricholomataceae). Their structures have been assigned on the basis of a detailed study of their spectral data. Their relative configurations were established from the nuclear Overhauser effects.

Isolation and structure elucidation of armillaricin1

From the petroleum ether extracts of the artificially cultured mycelium of ARMILLARIA MELLEA, a novel sesquiterpenoid aromatic ester named armillaricin has been isolated by silica gel column chromatography. Its structure was deduced from spectral data and confirmed by single-crystal X-ray analysis.

Isolation and structures of two new sesquiterpenoid aromatic esters: armillarigin and armillarikin1

The continued investigation of the mycelial extract of ARMILLARIA MELLEA (Vahl.ex Fr.) Quel. (Tricholomelaceae) led to the isolation of two new sesquiterpenoid aromatic esters, named armillarigin ( 1) and armillarikin ( 2). Their structures were elucidated on the basis of spectral data and chemical transformation.

Experimental autoimmune arthritis in mice. I. Homologous type II collagen is responsible for self-perpetuating chronic polyarthritis

Immunisation with heterologous type II collagen (CII) induces arthritis in mice of the DBA/1 strain, which is genetically susceptible to this disease. To develop an experimental model of autoimmunity more adequate for the study of human rheumatoid arthritis (RA), DBA/1 mice were injected with 100 micrograms of native CII that had been purified from mouse xiphoid cartilage. About six weeks later the animals developed a chronic progressive polyarthritis involving the four paws but mainly confined to interphalangeal and metatarsophalangeal joints. The evolution of the disease fluctuated between remissions and exacerbations. The initial lesions assessed by clinical observations were more severe when the disease occurred early than in the case of late onset. Interestingly, the incidence of arthritis was clearly preponderant in males, and, moreover, the few female mice which developed arthritis had mild disease states with lower arthritic scores than the males. Varying levels of autoantibodies against mouse CII were found in the sera of immunised animals, regardless of the development of arthritis. These data indicate that the injection of homologous CII into mice caused a polyarthritis that is clinically closer to the human RA than the disease induced with heterologous CII and therefore will represent a useful tool for the study of the self-perpetuating mechanisms that characterise RA.

Aerosol lead and associated elements in Beijing, China

The relative importance of local and regional sources of lead and associated elements in fine and coarse aerosol particles of an urban atmosphere was assessed by means of a two-day study, July 20 and 30, 1980 in Beijing, China. Five near-ground locations were selected for aerosol sampling by cascade impactors and elemental analysis by proton induced X-ray emission (PIXE): the imperial palace courtyard, a park, near two streets, and a mid-street traffic island. These sites, ranked in order of increasing traffic intensity and fugitive surface dust, showed that concentrations of major dust constitutents, represented by coarse particle (>2 μm diameter) Si, Al, and Ca, increased correspondingly. Pb, as well as Zn, As, and Cu, were present mainly in fine (<2 μm) particles; their concentrations were unrelated to traffic, indicating they resulted mainly from regional combustion or other sources. However, these elements also were present in coarse particles at concentrations that varied with the major dust elements and were relatively enriched, compared to average earth crust rock material, by factors of more than 100 (Pb), 50 (Zn), and 10 (Cu). Nonurban Beijing shows much smaller coarse aerosol enrichments of Pb, Zn, and Cu, indicating urban contamination of surface dust. Published data from St. Louis, USA show both fine and coarse aerosol Pb and Zn. Compared with Beijing, fine and coarse concentrations in St. Louis are similar for Pb, but lower for Zn, Ca, and Fe. Both Pb and Zn are enriched relative to earth crust composition to a greater degree in St. Louis than Beijing in both fine and coarse particle size ranges. The results suggest that heavy metals from combustion occur in the air as fine particles and, after deposition on the surface, as reentrained coarse particles of fugitive dust. Both many contribute to human exposures of these heavy metals.

[Monomeric Indole Alkaloids from Kopsia officinalis.]

Ten monomeric indole alkaloids have been identified from the roots of KOPSIA OFFICINALIS. Four of them are known: (-)-kopsinine 1, (+)-5,22-dioxokopsane 2, (-)-tetrahydroalstonine 4, and (-)-quebrachamine 3; and six are new: (-)-isoeburnamine 5 (enantiomer of the known alkaloid (+)-isoeburnamine), (-)-N-methoxycarbonyl-12-methoxykopsinaline 7, (-)-N-methoxycarbonyl-11,12-methylenedioxy kopsinaline 8, (-)-N-methoxycarbonyl-11,12-dimethoxykopsinaline 9, (-)-11,12-methylenedioxykopsinaline 10, and (-)-12-methoxykopsinaline 11.

Monomeric Indole Alkaloids from Ervatamia hainanensis

Eleven monomeric indole alkaloids have been isolated from the roots of Ervatamia hainanensis. Nine of them are known: coronaridine 1, coronaridine hydroxyindolenine 2, heyneanine 3, vobasine 4, perivine 5, ibogamine 6, geissoschizol 7, 10-hydroxygeissoschizol 8 and 3-oxocoronaridine 9; and two are new: 10-hydroxyheyneanine 10 and 3-(beta-hydroxyethyl)-coronaridine 11.