[Parmacognostical identification of Dodartia orientalis].
The descriptions, microsopical characters, UV of Dodartia orientalis L. were studied. It can provide a basis for the identification of D. orientalis.
Drugs, Chinese Herbal↗
Biomedical subjects
Y Cheng
Publications and source records attributed to Y Cheng.
[Morphological and histological studies of herba sedum aizoon].
The description characters of Herba Sedum aizoon were recounted. And the histological characters of the root, rhizome, stem, leaf and flower of the plant were reported. The characters of the isolated tissue and powder were also involved. These results provided valuable reference information for putting the medicinal resource to rational exploitage and use.
Crassulaceae↗
The three-dimensional map of microsomal glutathione transferase 1 at 6 A resolution.
Microsomal glutathione transferase 1 (MGST1) is representative of a superfamily of membrane proteins where different members display distinct or overlapping physiological functions, including detoxication of reactive electrophiles (glutathione transferase), reduction of lipid hydroperoxides (glutathione peroxidase), and production of leukotrienes and prostaglandin E. It follows that members of this superfamily constitute important drug targets regarding asthma, inflammation and the febrile response. Here we propose that this superfamily consists of a new class of membrane proteins built on a common left-handed four-helix bundle motif within the membrane, as determined by electron crystallography of MGST1 at 6 A resolution. Based on the 3D map and biochemical data we discuss a model for the membrane topology. The 3D structure differs significantly from that of soluble glutathione transferases, which display overlapping substrate specificity with MGST1.
Amino Acid Motifs↗
Protoplast preparation and regeneration from spores of the biocontrol fungus Pseudozyma flocculosa.
This paper describes a specific protocol for yielding and regenerating protoplasts from spores of the recently described powdery mildew biocontrol agent Pseudozyma flocculosa. With this protocol, a large quantity of protoplasts was obtained from beta-mercaptoethanol-pretreated spores in 3-day-old cultures of P. flocculosa grown in YMPD. Enzymatic digestion was optimal with 0.5% Novozym 234 and 5% Glucanex prepared in 0.6 M KCl in 0.1 M citrate buffer. All liberated protoplasts fluoresced in the presence of fluorescein diacetate indicating that viability was nearly 100%. The regeneration rate was equally outstanding reaching 75% when 0.8 M sucrose was used as osmotic stabilizer in the regeneration medium. This protocol will find useful applications in genetic studies of this poorly characterized and understood biocontrol agent.
Basidiomycota↗
Prolactin-induced cell proliferation in PC12 cells depends on JNK but not ERK activation.
The effects of pituitary and extrapituitary prolactin include cellular proliferation and differentiation. PC12 cells was used as a model to delineate respective signaling of prolactin. Prolactin acted as a mitogen for undifferentiated PC12 cells, as measured by significant increases in bromodeoxyuridine incorporation and in cell numbers, with an efficacy equal to epidermal growth factor. Both the long and short form of the prolactin receptor was expressed, yet only the long isoform was tyrosine-phosphorylated upon agonist binding. Functional prolactin receptor signaling was further demonstrated in the activation of JAK2 and phosphorylation activation of the transcription factors Stat1, -3, and -5a. Surprisingly, prolactin stimulated a sustained activation of Raf-B, without activation of the MAP kinases ERK1 or -2. Instead, in solid phase kinase assays using a glutathione S-transferase-c-Jun fusion protein (amino acids 1-79) as the substrate, a significant activation of the mitogen-activated protein Janus kinase (c-Jun N-terminal kinase; JNK) was observed. The prolactin-induced activation of JNK was prolonged and accompanied by a significant increase in c-Jun mRNA abundance and c-Jun protein synthesis. Moreover, analysis of bromodeoxyuridine incorporation at the single cell level revealed that epidermal growth factor-dependent incorporation was inhibited by PD98059 and independent of SB203580, whereas prolactin-induced incorporation was ERK and mitogen-activated protein kinase p38 independent but was abolished with JNK inhibition by 30 microm SB203580. Our studies suggest that prolactin may have a role in the growth of PC12 cells, where it stimulates concurrent mitogenic and differentiation-promoting signaling pathways.
Animals↗
Identification of a tetrameric hedgehog signaling complex.
Hedgehog (Hh) signal transduction requires a large cytoplasmic multi-protein complex that binds microtubules in an Hh-dependent manner. Here, we show that three members of this complex, Costal2 (Cos2), Fused (Fu), and Cubitus interruptus (Ci), bind each other directly to form a trimeric complex. We demonstrate that this trimeric signaling complex exists in Drosophila lacking Suppressor of Fused (Su(fu)), an extragenic suppressor of fu, indicating that Su(fu) is not required for the formation, or apparently function, of the Hh signaling complex. However, we subsequently show that Su(fu), although not a requisite component of this complex, does form a tetrameric complex with Fu, Cos2, and Ci. This additional Su(fu)-containing Hh signaling complex does not appear to be enriched on microtubules. Additionally, we demonstrate that in response to Hh Ci accumulates in the nucleus without its various cytoplasmic binding partners, including Su(fu). We discuss a model in which Su(fu) and Cos2 each bind to Fu and Ci to exert some redundant effect on Ci such as cytoplasmic retention. This model is consistent with genetic data demonstrating that Su(fu) is not required for Hh signal transduction proper and with the elaborate genetic interactions observed among Su(fu), fu, cos2, and ci.
Animals↗
Combinatorial diversification of indinavir: in vivo mixture dosing of an HIV protease inhibitor library.
An efficient combination solution-phase/solid-phase route enabling the diversification of the P1', P2', and P3 subsites of indinavir has been established. The synthetic sequence can facilitate the rapid generation of HIV protease inhibitors possessing more favorable pharmacokinetic properties as well as enhanced potencies. Multiple compound dosing in vivo may also accelerate the identification of potential drug candidates.
Animals↗
Chick sox10, a transcription factor expressed in both early neural crest cells and central nervous system.
Human SOX10 and mouse Sox10 have been cloned and shown to be expressed in the neural crest derivatives that contribute to formation of the peripheral nervous system during embryogenesis. Mutations in Sox10 have been identified as a cause of the Dominant megacolon mouse and Waardenburg-Shah syndrome in human, both of which include defects in the enteric nervous system and pigmentation (and in the latter, sometimes hearing). We have cloned a chick Sox10 ortholog (cSox10) in order to study its role in neural crest cell development. This cDNA reveals a 1383 bp open reading frame encoding 461 amino acids which is highly conserved with human SOX10 and mouse Sox10. In situ hybridization showed cSox10 is expressed in migrating neural crest cells just after the zinc finger transcription factor Slug, but is lost as cells undergo neuronal differentiation in ganglia of the peripheral nervous system. In addition, cSox10 is expressed in the developing otic vesicle, the developing central nervous system and pineal gland.
Animals↗
Disruption of synaptic transmission or clock-gene-product oscillations in circadian pacemaker cells of Drosophila cause abnormal behavioral rhythms.
To study the function of clock-gene-expressing neurons, the tetanus-toxin light chain (TeTxLC), which blocks chemical synaptic transmission, was expressed under the control of promoters of the clock genes period (per) and timeless (tim), each fused to GAL4-encoding sequences. Although TeTxLC did not affect cycling of a clock-gene product at the gross level, it disrupted the rhythmic behavior of adult Drosophila. In constant darkness, the proportion of rhythmic flies was reduced in flies expressing active TeTxLC compared to controls, including those expressing inactive toxin. The behavior of TeTxLC-expressing flies was less synchronized to light:dark cycles than that of controls. To determine which neurons are responsible for these effects on behavior, the toxin was also expressed in restricted subsets of per/tim-expressing, laterally located pacemaker neurons by expressing TeTxLC under the control of a driver in which GAL4-encoding sequences are fused to the promoter of the pigment dispersing factor (pdf) gene. pdf-gal4-driven TeTxLC expression had relatively little effect on behavioral rhythms, implying that per/tim neurons other than pdf-expressing lateral neurons participate in the generation of rhythmic behavior. In another set of experiments, period gene products were expressed under the control of per-gal4 or tim-gal4. This resulted in an increased level of PER protein in many brain cells and reduction of bioluminescence cycling reported by a per-luciferase transgene, especially in the case of per expression affected by tim-gal4. This indicates a disruption of the transcriptional feedback loop that is a part of the oscillatory mechanism underlying Drosophila's circadian rhythms. Consistent with this molecular defect, the proportion of rhythmic individuals in constant darkness was subnormal in flies expressing PER under the control of tim-gal4, and their behavior in light:dark cycles was abnormal.
Animals↗
Association between psychosocial work characteristics and health functioning in American women: prospective study.
OBJECTIVE: To examine prospectively the relation between psychosocial work characteristics and changes in health related quality of life over four years in a cohort of working women in the United States. DESIGN: Longitudinal cohort study. SETTING: United States. PARTICIPANTS: 21 290 female registered nurses who completed the Karasek's job content questionnaire and a modified version of the short form 36 questionnaire (SF-36) as used for a survey of health status by the medical outcomes study. MAIN OUTCOME MEASURES: Seven dimensions of health status: physical functioning, role limitations due to physical health problems, bodily pain, vitality, social functioning, role limitations due to emotional problems, and mental health. RESULTS: Examined separately low job control, high job demands, and low work related social support were associated with poor health status at baseline as well as greater functional declines over the four year follow up period. Examined in combination, women with low job control, high job demands, and low work related social support ("iso-strain" jobs) had the greatest functional declines. These associations could not be explained by age, body mass index, comorbid disease status, alcohol consumption, smoking status, education level, exercise level, employment status, marital status, or presence of a confidant. CONCLUSIONS: Adverse psychosocial work conditions are important predictors of poor functional status and its decline over time.
Adult↗
A redox reaction to synthesize nanocrystalline Cu2-xSe in aqueous solution.
Explore the source record for details and available documents.
Journal Article↗
Triapine (3-aminopyridine-2-carboxaldehyde- thiosemicarbazone): A potent inhibitor of ribonucleotide reductase activity with broad spectrum antitumor activity.
Previous studies from our laboratories have shown that (a) Triapine() is a potent inhibitor of ribonucleotide reductase activity and (b) hydroxyurea-resistant L1210 leukemia cells are fully sensitive to Triapine. In an analogous manner, Triapine was similarly active against the wild-type and a hydroxyurea-resistant subline of the human KB nasopharyngeal carcinoma. Triapine was active in vivo against the L1210 leukemia over a broad range of dosages and was curative for some mice. This agent also caused pronounced inhibition of the growth of the murine M109 lung carcinoma and human A2780 ovarian carcinoma xenografts in mice. Optimum anticancer activity required twice daily dosing due to the duration of inhibition of DNA synthesis which lasted about 10 hr in L1210 cells treated with Triapine in vivo. DNA synthesis in normal mouse tissues (i.e. duodenum and bone marrow) uniformly recovered faster than that in L1210 leukemia cells, demonstrating a pharmacological basis for the therapeutic index of this agent. Triapine was more potent than hydroxyurea in inhibiting DNA synthesis in L1210 cells in vivo, and the effects of Triapine were more pronounced. In addition, the duration of the inhibition of DNA synthesis in leukemia cells from mice treated with Triapine was considerably longer than in those from animals treated with hydroxyurea. Combination of Triapine with various classes of agents that damage DNA (e.g. etoposide, cisplatin, doxorubicin, and 1-acetyl-1,2-bis(methylsulfonyl)-2-(2-chloroethyl)hydrazine) resulted in synergistic inhibition of the L1210 leukemia, producing long-term survivors of tumor-bearing mice treated with several dosage levels of the combinations, whereas no enhancement of survival was found when Triapine was combined with gemcitabine or cytosine arabinoside. The findings demonstrate the superiority of Triapine over hydroxyurea as an anticancer agent and further suggest that prevention by Triapine of repair of DNA lesions created by agents that damage DNA may result in efficacious drug combinations for the treatment of cancer.
Animals↗
Seed plant phylogeny inferred from all three plant genomes: monophyly of extant gymnosperms and origin of Gnetales from conifers.
Phylogenetic relationships among the five groups of extant seed plants are presently quite unclear. For example, morphological studies consistently identify the Gnetales as the extant sister group to angiosperms (the so-called "anthophyte" hypothesis), whereas a number of molecular studies recover gymnosperm monophyly, and few agree with the morphology-based placement of Gnetales. To better resolve these and other unsettled issues, we have generated a new molecular data set of mitochondrial small subunit rRNA sequences, and have analyzed these data together with comparable data sets for the nuclear small subunit rRNA gene and the chloroplast rbcL gene. All nuclear analyses strongly ally Gnetales with a monophyletic conifers, whereas all mitochondrial analyses and those chloroplast analyses that take into account saturation of third-codon position transitions actually place Gnetales within conifers, as the sister group to the Pinaceae. Combined analyses of all three genes strongly support this latter relationship, which to our knowledge has never been suggested before. The combined analyses also strongly support monophyly of extant gymnosperms, with cycads identified as the basal-most group of gymnosperms, Ginkgo as the next basal, and all conifers except for Pinaceae as sister to the Gnetales + Pinaceae clade. According to these findings, the Gnetales may be viewed as extremely divergent conifers, and the many morphological similarities between angiosperms and Gnetales (e.g., double fertilization and flower-like reproductive structures) arose independently.
Cycadopsida↗
Role of endothelium in thapsigargin-induced arterial responses in rat aorta.
We assessed the role of endothelium in the arterial response to thapsigargin, the Ca(2+)-ATPase inhibitor of the endoplasmic reticulum, in rat isolated aortic rings. Thapsigargin induced an endothelium-dependent relaxation of phenylephrine-contracted aortic rings with an EC(50) of 2.6+/-0.4 nM and a 75% maximum relaxation, while it was less effective against 30 mM K(+)-induced contraction. Pretreatment of aortic rings with N(G)-nitro-L-arginine methyl ester (30 microM) or methylene blue (1 microM) reduced thapsigargin-induced relaxation by approximately 85%. Thapsigargin failed to relax the endothelium-denuded rings. L-Arginine (3 mM) partially, but significantly, antagonized the effect of 30 microM N(G)-nitro-L-arginine methyl ester. Pretreatment with indomethacin (3 microM), glibenclamide (1 microM) or iberiotoxin (100 nM) did not alter the thapsigargin-induced relaxation. In contrast, pretreatment with tetrapentylammonium ions (TPA(+), 1-3 microM) or with 300 microM Ba(2+) suppressed the relaxant response to thapsigargin. TPA(+) (3 microM) also attenuated acetylcholine-induced relaxation. Thapsigargin-induced endothelium-dependent relaxation was primarily dependent on the presence of extracellular Ca(2+). Interestingly, when the tissues were exposed to very low concentrations of thapsigargin (1-3 nM) the nitric oxide-dependent relaxation induced by acetylcholine or A23187 was markedly reduced. While thapsigargin (3 nM) did not influence the relaxation induced by endothelium-independent dilators, sodium nitroprusside and verapamil. These results indicate that thapsigargin produced complex vascular effects primarily by acting on the endothelial cells. Thapsigargin causes an endothelial nitric oxide-dependent relaxation; on the other hand, it inhibits nitric oxide-mediated relaxation at the similar concentrations. Activation of TPA(+)- and Ba(2+)-sensitive but not Ca(2+)-activated or ATP-sensitive K(+) channels may be also involved in thapsigargin-induced relaxation of rat isolated aortic rings.
Animals↗
Orally administrated cerium chloride induces the conformational changes of rat hemoglobin, the hydrolysis of 2,3-DPG and the oxidation of heme-Fe(II), leading to changes of oxygen affinity.
The structure and oxygen affinity of hemoglobin from erythrocytes of CeCl(3) fed Wistar rats in the dose range of 0.2-20.0 mg/kg body weight/day were investigated by means of various spectroscopic methods. The changes in oxygen saturation curves of hemoglobin are dependent upon both feeding dose and feeding time. After 40 days feeding with 20 mg CeCl(3)/kg body weight/day, the curve changed to a double sigmoid shape and the oxygen affinity in low oxygen pressure increases. It regained the sigmoid form after 80 days feeding, but the degree of oxygen saturation in higher oxygen pressure became higher than that in the control. These results indicate that CeCl(3) can increase the oxygen affinity of hemoglobin of rat erythrocytes. This effect is further demonstrated by the analysis of Mössbauer spectra of erythrocytes. Increase of hemoglobin content in erythrocytes was found in rats fed with CeCl(3). It might be the offset response to the poor oxygen-releasing capability of the hemoglobin. CD and FT-IR deconvoluted spectra indicate that secondary structures of hemoglobin have remarkable changes, characterized by a gradual decrease of alpha-helix content, in a dose- and feeding time-dependent fashion. Meanwhile, the 31P NMR spectra demonstrate that the level of 2,3-diphosphoglyceric acid (2,3-DPG) in erythrocytes, an allosteric regulator of oxygen release from hemoglobin, decreases due to its hydrolysis. In addition, the Mössbauer and ESR spectra show clearly that a fraction of the heme-iron changes from Fe (II) to Fe (III) in CeCl(3) fed rats. The results indicate that the oral administration of CeCl(3) leads to a microenvironment changes of heme in intracellular hemoglobin. Oxygen affinity changes might be attributed to a series of events triggered by the binding of Ce (III) to hemoglobin and 2,3-DPG, including conformational changes of hemoglobin and 2,3-DPG hydrolysis, respectively and also the partial transformation from heme-Fe (II) to heme-Fe (III).
2,3-Diphosphoglycerate↗
Physical activity and self-reported, physician-diagnosed osteoarthritis: is physical activity a risk factor?
This prospective study evaluated regular physical activity and self-reported physician-diagnosed osteoarthritis of the knee and/or hip joints among 16,961 people, ages 20-87, examined at the Cooper Clinic between 1970 and 1995. Among those aged 50 years and older, osteoarthritis incidence was higher among women (7.0 per 1000 person-years) than among men (4.9 per 1000 person-years, P = 0.001), while among those under 50 years of age, osteoarthritis incidence was similar between men (2.6) and women (2.7). High levels of physical activity (running 20 or more miles per week) were associated with osteoarthritis among men under age 50 after controlling for body mass index, smoking, and use of alcohol or caffeine (hazard ratio = 2.4, 95% CI: 1.5, 3.9), while no relationship was suggested among women or older men. These findings support the conclusion that high levels of physical activity may be a risk factor for symptomatic osteoarthritis among men under age 50.
Adult↗
[Effects of glutamate and glutamine on learning and memory of rats].
The effects of glutamate (Glu) and glutamine (Gln) on learning and memory of rats and the mechanism involved were examined. Three groups of rats were fed with stock diet (control group), and the diets supplemented with 2% Glu (Glu group) or 2% Gln (Gln group) respectively. Compared with control group, the active avoidance response rats of Gln group in shuttle box test was significantly elevated while the time of passive avoidance response shortened. The contents of brain free amino acids, such as Gln, Glu, aspartic acid and arginine, activity of brain nitric oxide synthase (NOS), Bmax of N-methyl-D-aspartate(NMDA) receptors in hippocampus of Gln group were all increased significantly. Such changes were not observed in Glu group. The results suggested that Gln could improve the learning ability and memory of rats, which might be related to the change of amino acids composition of brain, the synthesis of messenger nitric oxide and the binding capacity of NMDA receptor in hippocampus.
Animals↗
Serological and histological findings in infection and transmission of GBV-C/HGV to macaques.
Seven healthy macaques were inoculated with the GBV-C/HGV-RNA serum from a non-A-E hepatitis patient. The serology and pathology of the liver in the animals were observed. The results indicated that all inoculated animals were infected with a GBV-C/HGV-RNA viremia and had mildly abnormal alanine transaminase levels during the infectious period. The histology, immuno-histochemistry, and in situ hybridization in the liver tissues of the inoculated animals also showed that there was a very mild hepatitis with the positive antigenic expression and the genome of GBV-C/HGV-NS5 in hepatocytes. The pathological changes in the infected animals appeared to become normal whether or not GBV-C/HGV-RNA viremia persisted. There is a possibility that the mild virulence of the GBV-C/HGV to the host became harmless with time after inoculation. Infection and the transmission of the GBV-C/HGV virus in the macaques provides an appropriate animal model and new information about GBV-C/HGV infection in both humans and animals. It is possible that this virus is a mild and self-limited pathogenic agent to the hepatic cells of primates.
Alanine Transaminase↗