A new nortriterpenoid from Rostrinucula dependens.
A new nortriterpenoid rostrinucin (1), together with five known compounds were isolated from Rostrinucula dependens. The structure of 1 was elucidated by spectroscopic evidence.
Biomedical subjects
Publications and source records attributed to Rui Li.
A new nortriterpenoid rostrinucin (1), together with five known compounds were isolated from Rostrinucula dependens. The structure of 1 was elucidated by spectroscopic evidence.
An efficient kinetic resolution of racemic Betti base with L-(+)-tartaric acid in acetone was developed based on a novel enantioselective N,O-deketalization, by which the enantiopure R- and S-enantiomers of Betti base were obtained as the corresponding N,O-ketal compound and salt with L-(+)-tartaric acid, respectively, in excellent yields with a practically foolproof operation.
Three types of 11-electron analytic effective core potentials (ECPs) and their corresponding double-zeta and single-zeta basis sets of gold are evaluated using density functional theory (DFT) calculations. We find that, compared with basis sets derived for use with Hatree-Fock-based Los Alamos (LANL1) and Ermler-Christiansen (EC) ECPs, the DFT-derived Troullier-Martins (TM) ECP together with a single-zeta basis set (TMSZ) is more suitable to describe not only the interaction between gold atoms with a benzene-1,4-dithiolate molecule but also the electronic structure of an infinite 1-dimensional monatomic gold chain. Hence, TMSZ is the best single-zeta basis set with an 11-electron ECP for gold available currently to be used in theoretical calculations on electrical properties of molecular electronic devices with DFT based Green's function method employing a finite analytic basis of local orbitals.
Estrogen provides neuroprotection against neurodegenerative diseases, including Parkinson's disease. Its effects may stem from interactions with neurons, astrocytes, and microglia. We demonstrate here in primary cultures of rat mesencephalic neurons that estrogen protects them from injury induced by conditioned medium obtained from lipopolysaccharide (LPS)-activated microglia. LPS-induced nitrite production and tumor necrosis factor-alpha up-regulation in microglia were blocked by estrogen pretreatment. Estrogen neuroprotection was related to microglial activation of estrogen receptors (ERs), insofar as the protective effect of the microglia-conditioned medium was overridden by pretreatment of microglia with the ER antagonist ICI 182,780. On the other hand, the specific ERalpha antagonist, MPP dihydrochloride, only partially blocked the effects of estrogen, suggesting that estrogen protection was mediated via both ERalpha and ERbeta. LPS treatment did not change ERalpha mRNA levels in microglia, astrocytes, and neurons, but it up-regulated ERbeta mRNA levels in microglia and astrocytes. Similarly, increased ERbeta protein levels were detected in LPS-activated microglia. More interesting was that immunocytochemical analysis revealed that ERbeta was localized in the cytoplasm of microglia and in the cell nucleus of astrocytes and neurons. In summary, our results support the notion that estrogen inhibits microglial activation and thus exhibits neuroprotective effects through both ERalpha and ERbeta activation. The cytoplasm location of microglial ERbeta suggests the possible involvement of nonclassical effects of estrogen on microglia. Changes in microglial ERbeta expression levels may modulate such effects of estrogen.
IkappaB kinases (IKKs), IKKalpha and IKKbeta, with a regulatory subunit IKKgamma/NEMO constitute a high molecular weight IKK complex that regulates NF-kappaB activity. Although IKKalpha and IKKbeta share structural and biochemical similarities, IKKalpha has been shown to have distinct biological roles. Here we show that IKKalpha plays a critical role in regulating cyclin D1 during the cell cycle. Analysis of IKKalpha-/- mouse embryo fibroblast cells showed that cyclin D1 is overexpressed and localized in the nucleus compared with parental mouse embryo fibroblasts. IKKalpha associates with and phosphorylates cyclin D1. Analysis on cyclin D1 mutants demonstrated that IKKalpha phosphorylates cyclin D1 at Thr286. Reconstitution of IKKalpha in knockout cells leads to nuclear export and increased degradation of cyclin D1. Further, RNAi-mediated knockdown of IKKalpha results in similar changes as observed in IKKalpha-/- cells. These results suggest a novel role of IKKalpha in regulating subcellular localization and proteolysis of cyclin D1 by phosphorylation of cyclin D1 at Thr286, the same residue earlier found to be a target for glycogen synthase kinase-3beta-induced phosphorylation.
Hepatocellular carcinoma (HCC) is one of the major malignancies worldwide. We have previously characterized global gene expression patterns in HCC using microarrays. Here, we report the analysis of genomic DNA copy number among 49 HCC samples using BAC array-based comparative genomic hybridization (CGH). We observed recurrent and characteristic chromosomal aberrations, including frequent DNA copy number gains of 1q, 6p, 8q and 20q, and losses of 4q, 8p, 13q, 16q and 17p. We correlated gene expression with array CGH data, and identified a set of genes whose expression levels correlated with common chromosomal aberrations in HCC. Especially, we noticed that high expression of Jab1 in HCC significantly correlated with DNA copy number gain at 8q. Quantitative microsatellite analysis further confirmed DNA copy number gain at the Jab1 locus. Overexpression of Jab1 in HCC was also validated using real-time RT-PCR, and Jab1 protein levels were studied by immunohistochemistry on tissue microarrays. Functional analysis in HCC cell lines demonstrated that Jab1 may regulate HCC cell proliferation, thereby having a potential role in HCC development. In conclusion, this study shows that array-based CGH provides high resolution mapping of chromosomal aberrations in HCC, and demonstrates the feasibility of correlating array CGH data with gene expression data to identify novel oncogenes and tumor suppressor genes.
OBJECTIVE: To study the effectiveness and clinical significance of transmaxillary approach for surgical removal of Al-Mefty type III clival chordomas. METHODS: Ten cases of Al-Mefty type III clival chordoma were treated via the transmaxillary approach and followed up for 34 months on average (10 approximately 56 months). RESULTS: Microscopic total removal of the tumors was achieved in 8 patients, and subtotal removal was achieved in the rest 2 patients. Three patients had tumor recurrence but still lived with tumors 26, 36, and 40 months after operation. The other 7 patients resumed their routine life without tumor. The postoperative complications included infection in 1 case that was cured by antibiotic therapy, postoperative obstructive dyspnoea in 1 case that required tracheostomy, and CSF leakage in 1 case that stopped spontaneously 3 weeks after operation. CONCLUSION: With better exposure, complete removal, and with less brain damages and satisfactory results, transmaxillary approach is effective for surgical treatment of Al-Mefty type III clival chordomas.
Hepatocellular carcinoma (HCC) is one of the major causes of cancer deaths worldwide. New diagnostic and therapeutic options are needed for more effective and early detection and treatment of this malignancy. We identified 703 genes that are highly expressed in HCC using DNA microarrays, and further characterized them in order to uncover novel tumor markers, oncogenes, and therapeutic targets for HCC. Using Gene Ontology annotations, genes with functions related to cell proliferation and cell cycle, chromatin, repair, and transcription were found to be significantly enriched in this list of highly expressed genes. We also identified a set of genes that encode secreted (e.g. GPC3, LCN2, and DKK1) or membrane-bound proteins (e.g. GPC3, IGSF1, and PSK-1), which may be attractive candidates for the diagnosis of HCC. A significant enrichment of genes highly expressed in HCC was found on chromosomes 1q, 6p, 8q, and 20q, and we also identified chromosomal clusters of genes highly expressed in HCC. The microarray analyses were validated by RT-PCR and PCR. This approach of integrating other biological information with gene expression in the analysis helps select aberrantly expressed genes in HCC that may be further studied for their diagnostic or therapeutic utility.
BACKGROUND: Microvascular Decompression (MVD) operation is the most reliable treatment for hemifacial spasm (HFS), but it causes many complications. The aim of this retrospective study was to investigate the factors relavent to the effects and postoperative complications of microvascular decompression on hemifacial spasm. METHODS: A total of 1200 HFS patients treated with MVD were studied retrospectively. The root exit zone (REZ) of the facial nerve was exposed through the infraflocculus approach, the offending vessels were identified and separated from the REZ, and a Teflon graft was interposed between the offending vessels and the brain stem. Brain stem auditory evoked potential (AEP) was monitored intraoperatively. RESULTS: The offending vessels can be identified in all patients. The anteroinferior cerebellar artery was the main offending vessel (42.6%). Patients with vertebral artery compression had a multiple vascular compression fashion. Follow-up for 2 - 10 years (mean 4.2 years) showed that 88.7% patients were cured and 5.6% relieved, with an effective rate of 94.3%. Recurrence rate was 3.2%, and the ineffective rate was 2.6%. The most frequent complication was hearing dysfunction (2.8%). CONCLUSIONS: MVD is the most definitive treatment method of HFS. The key procedures of this operation include adequate exposure of the REZ, identification of the offending vessels, and proper positioning of Teflon grafts. Complications can be reduced effectively by utilizing a real-time AEP monitoring during the operation.
Total syntheses of enantiopure alkaloidal natural products (2S,6R)-dihydropinidine (as hydrochloride) and (2S,6R)-isosolenopsins (as hydrochlorides) were achieved in four steps and in 80-82% total yields by using a synthetic strategy of the formation-cleavage of 1,3-oxazinane. (S)-Betti base was proved to be an excellent chiral auxiliary and a novel Pd/C catalyzed N-debenzylation straightforward to amine hydrochloride was developed in the presence of CH2Cl2.
CONTEXT: Contingency management interventions that provide tangible incentives based on objective indicators of drug abstinence are efficacious in improving outcomes in substance abusers, but these treatments have rarely been implemented in community-based settings. OBJECTIVE: To evaluate the efficacy of an abstinence-based contingency management intervention as an addition to usual care in community treatment settings. DESIGN: Random assignment to usual care or usual care plus abstinence-based incentives for 12 weeks. SETTING: Eight community-based outpatient psychosocial drug abuse treatment programs. PARTICIPANTS: A total of 415 cocaine or methamphetamine users beginning outpatient substance abuse treatment. INTERVENTION: All participants received standard care, and those assigned to the abstinence-based incentive condition also earned chances to win prizes for submitting substance-free urine samples; the chances of winning prizes increased with continuous time abstinent. MAIN OUTCOME MEASURES: Retention, counseling attendance, total number of substance-free samples provided, percentage of stimulant- and alcohol-free samples submitted, and longest duration of confirmed stimulant abstinence. RESULTS: Participants assigned to the abstinence-based incentive condition remained in treatment for a mean +/- SD of 8.0 +/- 4.2 weeks and attended a mean +/- SD of 19.2 +/- 16.8 counseling sessions compared with 6.9 +/- 4.4 weeks and 15.7 +/- 14.4 sessions for those assigned to the usual care condition (P<.02 for all). Participants in the abstinence-based incentive condition also submitted significantly more stimulant- and alcohol-free samples (P<.001). The abstinence-based incentive group was significantly more likely to achieve 4, 8, and 12 weeks of continuous abstinence than the control group, with odds ratios of 2.5, 2.7, and 4.5, respectively. However, the percentage of positive samples submitted was low overall and did not differ between conditions. CONCLUSION: The abstinence-based incentive procedure, which provided a mean of 203 dollars in prizes per participant, was efficacious in improving retention and associated abstinence outcomes.
We observed the clinical efficacy of topiramate for paroxysmal kinesigenic choreoathetosis (PKC). Topiramate was administered as a monotherapy with titrated dosages to 8 patients with PKC. Target daily dose of topiramate was 100 to 200 mg; the follow-up period ranged from 8 months to 2 years. All of the patients became attack-free, and side effects were mild. The results show that topiramate is effective as a monotherapy for treating patients with PKC. The response to topiramate indicates that the disease may be caused by an ion channel defect.
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can assess tumor perfusion, microvascular vessel wall permeability and extravascular-extracellular volume fraction. Analysis of DCE-MRI data is usually based on indicator dilution theory that requires knowledge of the concentration of the contrast agent in the blood plasma, the arterial input function (AIF). A method is presented that compares the tissues of interest (TOI) curve shape to that of a reference region (RR), thereby eliminating the need for direct AIF measurement. By assigning literature values for Ktrans (the blood perfusion-vessel permeability product) and v(e) (extravascular-extracellular volume fraction) in a reference tissue, it is possible to extract the Ktrans and v(e) values for a TOI without knowledge of the AIF. The operational RR equation for DCE-MRI analysis is derived, and its sensitivity to noise and incorrect assignment of the RR parameters is tested via simulations. The method is robust at noise levels of 10%, returning accurate (+/-20% in the worst case) and precise (+/-15% in the worst case) values. Errors in the TOI Ktrans and v(e) values scale approximately linearly with the errors in the assigned RR Ktrans and v(e) values. The methodology is then applied to a Lewis Lung Carcinoma mouse tumor model. A slowly enhancing TOI yielded Ktrans=0.039+/-0.002 min-1 and v(e)=0.46+/-0.01, while a rapidly enhancing region yielded Ktrans=0.35+/-0.05 min-1 and v(e)=0.31+/-0.01. Parametric Ktrans and v(e) mappings manifested a tumor periphery with elevated Ktrans (>0.30 min-1) and v(e) (>0.30) values. The main advantage of the RR approach is that it allows for quantitative assessment of tissue properties without having to obtain high temporal resolution images to characterize an AIF. This allows for acquiring images with higher spatial resolution and/or SNR, and therefore, increased ability to probe tissue heterogeneity.
There have been conflicting reports as to whether olanzapine produces lower occupancy of striatal dopamine D(2)/D(3) receptor than typical antipsychotic drugs and preferential occupancy of extrastriatal dopamine D(2)/D(3) receptors. We performed [(18)F] fallypride PET studies in six schizophrenic subjects treated with olanzapine and six schizophrenic subjects treated with haloperidol to examine the occupancy of striatal and extrastriatal dopamine receptors by these antipsychotic drugs. [(18)F] setoperone PET studies were performed in seven olanzapine-treated subjects to determine 5-HT(2A) receptor occupancy. Occupancy of dopamine D(2)/D(3) receptors by olanzapine was not significantly different from that seen with haloperidol in the putamen, ventral striatum, medial thalamus, amygdala, or temporal cortex, that is, 67.5-78.2% occupancy; olanzapine produced no preferential occupancy of dopamine D(2)/D(3) receptors in the ventral striatum, medial thalamus, amygdala, or temporal cortex. There was, however, significantly lower occupancy of substantia nigra/VTA dopamine D(2)/D(3) receptors in olanzapine-treated compared to haloperidol-treated subjects, that is, 40.2 vs 59.3% (p=0.0014, corrected for multiple comparisons); in olanzapine-treated subjects, the substantia nigra/VTA was the only region with significantly lower dopamine D(2)/D(3) receptor occupancy than the putamen, that is, 40.2 vs 69.2% (p<0.001, corrected for multiple comparison). Occupancy of 5-HT(2A) receptors was 85-93% in the olanzapine- treated subjects. The results of this study demonstrated that olanzapine does not produce preferential occupancy of extrastriatal dopamine D(2)/D(3) receptors but does spare substantia nigra/VTA receptors. Sparing of substantia nigra/VTA dopamine D(2)/D(3) receptor occupancy may contribute to the low incidence of extrapyramidal side effects in olanzapine-treated patients.
The presence of folic acid in enriched cereal grain products and the higher bioavailability of folic acid than food folate led to the expression of the 1998 folate RDA, 400 microg/d, as dietary folate equivalents (DFE). DFE are defined as: mug natural food folate + 1.7 x microg synthetic folic acid. The 1.7 multiplier was based on assumptions that added folic acid was 85% available and food folate was 50% available. The 85/50 ratio also inferred that the bioavailability of food folate was approximately 60% relative to added folic acid. The objective of this long-term controlled feeding study was to assess the dietary folate equivalency of folic acid. After a 2-wk period of folate restriction, women (n = 42, 18-45 y old) consumed either 400 or 800 microg DFE/d derived from various combinations of food folate and folic acid for 12 wk. Folic acid was converted to DFE using the 1.7 multiplier from the DFE calculation and was consumed with a meal throughout the treatment period. Folate status response to the various treatments was assessed during wk 12-14. Serum folate, RBC folate, and plasma total homocysteine did not differ among the 400 microg DFE/d groups or among the 800 microg DFE/d groups. In contrast, consumption of 800 microg DFE/d led to higher (P </= 0.05) serum and RBC folate than consumption of 400 microg DFE/d. These data support the validity of the 1.7 multiplier in the DFE equation and suggest that food folate bioavailability is approximately 60% that of added folic acid when consumed as part of a mixed diet.
Anti-parkinsonian agents, pramipexole (PPX) and ropinirole (ROP), have been reported to possess neuroprotective properties, both in vitro and in vivo. The mechanisms underlying neuroprotection afforded by the D3-preferring receptor agonists remain poorly understood. The present study demonstrates that incubation of primary mesencephalic cultures with PPX and ROP or the conditioned medium from PPX- or ROP-treated primary cultures induced a marked increase in the number of dopamine (DA) neurons in the cultures. Similar effects can be observed after incubating with the conditioned medium derived from PPX- and ROP-treated substantia nigra astroglia. Meanwhile, PPX and ROP can protect the primary cells from insult of 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of the neurotoxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). Furthermore, the neurotrophic effects of PPX and ROP on mesencephalic dopamine neurons could be significantly blocked by D3 receptor antagonist, but not by D2 receptor antagonist. Moreover, we found that the levels of glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) in the conditioned medium of mesencephalic cultures treated with PPX and ROP were significantly increased. Blocking GDNF and BDNF with the neutralizing antibodies, the neurotrophic effects of PPX and ROP were greatly diminished. These results suggest that D3 dopamine receptor-preferring agonists, PPX and ROP, exert neurotrophic effects on cultured DA neurons by modulating the production of endogenous GDNF and BDNF, which may participate in their neuroprotection.
The performance of medical groups is receiving increased attention. Relatively little conceptual or empirical work exists that examines the various dimensions of medical group performance. Using a national database of 693 medical groups, this article develops a scorecard approach to assessing group performance and presents a theory-driven framework for differentiating between high-performing versus low-performing medical groups. The clinical quality of care, financial performance, and organizational learning capability of medical groups are assessed in relation to environmental forces, resource acquisition and resource deployment factors, and a quality-centered culture. Findings support the utility of the performance scorecard approach and identification of a number of key factors differentiating high-performing from low-performing groups including, in particular, the importance of a quality-centered culture and the requirement of outside reporting from third party organizations. The findings hold a number of important implications for policy and practice, and the framework presented provides a foundation for future research.
OBJECTIVE: To investigate the prevalence and major risk factors of fatty liver among adult residents in Shanghai. METHODS: A cross-sectional survey with multiple-stage stratified cluster and random sampling was performed. All residents aged 16 and above were invited to participate in the survey; they came from four communities of Yangpu District and Pudong New District. Questionnaire, physical examination, serum lipid-profile, and 75 gram oral glucose tolerance test and ultrasonographic examination of liver were undertaken. Analysis of data was performed through SPSS 11.0 for Windows statistical package. RESULTS: A total of 3175 residents took part in the survey, which was 75% of adult residents of the investigated communities and 2.26/10 000 of Shanghai municipal residents. Of the 3175, 1218 were males and 1957 were females. The mean age of the participants was 52.4+/-15.1 years and ranged from 16 to 88 years. Fatty liver was detected with ultrasound examination in 661 participants (20.82%), among which 3.48% had alcoholic fatty liver, 4.08% had suspected alcoholic fatty liver, and 92.43% had nonalcoholic fatty liver. The age-adjusted, sex-adjusted prevalence of fatty liver in Shanghai adult residents was 17.29%, the prevalence of alcoholic fatty liver, suspicious alcoholic fatty liver, and nonalcoholic fatty liver in Shanghai adult residents were 0.79%, 1.15%, and 15.35%, respectively. The prevalence of fatty liver was increased with aging in males and in females. Among participants younger than 50 years old, the prevalence of fatty liver in males was significantly higher than that in females, but in participants older than 50 years the case was just the opposite, higher in females. The mean age (years), body mass index (BMI), waist circumference, blood pressure, fasting and two hour serum glucose level, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and the presence of obesity, diabetes mellitus, hypertension, dyslipidemia, and gallstones in the fatty liver group was significantly higher than those in the group without fatty liver, but the high-density lipoprotein cholesterol (HDL-C) level and the educational level were both lower in the fatty liver group. Logistic regression analysis demonstrated that the prevalence of fatty liver was only positively correlated to nine risk factors, including male sex, educational level, waist circumference, BMI, fasting glucose level, HDL-C, TG, hypertension and diabetes mellitus. In heavy drinkers, obesity increased the risk for fatty liver by 4.8-fold, but heavy drinking only increased the risk for fatty liver 1.5-fold (95% CI 0.9-2.6, P=0.1685). CONCLUSION: There is a high prevalence of fatty liver among adult residents in Shanghai, and nonalcoholic fatty liver is the major type. Metabolic disorders such as obesity and diabetes mellitus, hypertension and hyperlipidemia are more closely associated with fatty liver than heavy drinking in Shanghai.