Triterpenoids from the fruits of Melia toosendan Sieb. et Zucc. with α-glucosidase inhibitory activities.

Four previously unreported tirucallane-type triterpenoids (1-4), together with four known analogues (5-8), were isolated from the fruits of Melia toosendan Sieb. et Zucc. Their planar structures were comprehensively elucidated by detailed analyses of HRESIMS, 1D and 2D NMR spectra data. The relative configurations of 1-4 were determined by NOESY experiments. The comparison of experimental and calculated electronic circular dichroism (ECD) spectra led to the establishment of the absolute configurations of new compounds. All isolated triterpenoids were evaluated for their α-glucosidase inhibitory activities in vitro. Compounds 4 and 5 showed moderate α-glucosidase inhibitory activities with IC50 values of 120.3 ± 5.8 and 104.9 ± 7.1 µM, respectively.

Fusion protein of adenovirus E4orf4 and human epidermal growth factor inhibits tumor cell growth.

Adenovirus early region 4 open reading frame 4 (E4orf4) protein is a novel cell death factor that selectively induces apoptosis in cancer cells. This study evaluated tumor inhibitory effects of a protein made by fusion E4orf4 and human epidermal growth factor (EGF). EGF was used to ensure the selective targeting of EGF receptor (EGFR)-overexpressing tumor cells. Results showed that EGF-E4orf4 stimulated EGFR phosphorylation in a time- and dose-dependent manner. Confocal microscopy analysis showed both EGF-E4orf4 and EGF could be internalized via EGFR but they had different intercellular trafficking pathways. In vitro study showed that EGF-E4orf4 significantly inhibited the proliferation of BGC823 and in vivo study showed EGF-E4orf4 suppressed tumor growth in a dose-dependent fashion with an inhibition rate of 79% for MDA-MB-231 and 49% for BGC 823 (p < 0.05). No toxic effects were observed in the nude mice with a dose as high as 10 mg/kg of EGF-E4orf4. These results indicated that EGF-E4orf4 could be a potential drug for cancer therapy.

[Trafficking pathway and affectivity on extracellular signal-regulated kinase phosphorylation of anti-tumor fusion protein of epidermal growth factor-adenovirus early region 4 open reading frame 4 protein].

OBJECTIVE: To investigate the intracellular trafficking pathway of fusion protein epidermal growth factor-adenovirus early region 4 open reading frame 4 protein (EGF-E4orf4) internalized via epidermal growth factor (EGF) receptor and its affectivity on extracellular signal-regulated kinase (ERK) phosphorylation. METHODS: MDA-MB-231 and BGC823 cells were incubated with fluorescein isothiocyanate-EGF-E4orf4 or EGF at different time points. The specific molecular mark of early endosome or late lysosome was labeled by indirect immunofluorescence, and then colocalization staining was observed using confocal laser microscopy. The levels of ERK phosphorylation were detected by Western blot. RESULTS: The fluorescent signal of fusion protein EGF-E4orf4 accumulated within the cells and congregated to the perinuclear region. A nucleus localization of the fusion protein was only at MDA-MB-231 cell. Colocalization of EGF-E4orf4 with early endosome/late lysosome was observed. EGF-E4orf4 stimulated ERK phosphorylation, which was most obvious 10 minutes after stimulation, and then gradually attenuated, which was similar to EGF stimulation but with a less decrease. CONCLUSIONS: Internalized EGF-E4orf4 can be slowly degraded via endosome-lysosome pathway. The action features of EGF-E4orf4 are remarkably different between MDA-MB-231 and BGC823 cells, which may help explain the differences in its anti-tumor potency and in the special selectivity toward different tumor cells.

Review of tenofovir-emtricitabine.

Highly active antiretroviral therapy has significantly reduced HIV-related morbidity and mortality. Increasingly, fixed-dose antiretroviral combinations with equal or greater potency than traditional antiretrovirals, along with fewer side effects, reduced toxicity, and simplified dosing convenience are being utilized. Tenofovir-emtricitabine (TDF-FTC) represents one of the more recent fixed-dose combinations. In combination with either a ritonavir-boosted protease inhibitor or a non-nucleoside reverse transcriptase inhibitor, TDF-FTC is a preferred choice in recent treatment guidelines on the basis of demonstrated potency in randomized clinical trials, one-pill-a-day dosing convenience, and relatively low toxicity. In addition, the drug is active against hepatitis B virus. Caution must be exercised in patients with renal insufficiency, or when the drug is used with certain other drugs. This manuscript reviews the use of TDF-FTC in the treatment of HIV.

Mortality risk among new onset injection drug users.

AIMS: To characterize mortality experience among those who only recently started injection. DESIGN: Prospective study. SETTING: Independent study clinic within high drug use neighborhoods. PARTICIPANTS: In 1988-1989, we enrolled 256 adult injection drug users (IDUs) recruited through street outreach who had initiated injection within the prior 2 years. MEASUREMENTS: Consenting participants underwent venipuncture for HIV antibody testing and interviews. We prospectively ascertained date and cause of death through follow-up contact and registry linkages. Analyses included standardized mortality ratios (SMRs) with local, state and national mortality data, adjusted for age, gender and race. FINDINGS: Baseline median age was 30 years, 70% were male, 95% were African-American and 90% injected within the prior 6 months. We identified 69 deaths through October 2000; mortality rate was 3.3/100 person-years. The adjusted SMR with the USA (and Baltimore) as the reference for IDUs was 4.40 (2.43) for 1991-1992, which increased to 8.12 (4.13) by 1993-1994, decreased to 4.43 (2.13) by 1997-1998 and increased slightly to 5.35 (2.79) during 1999-2000. Excluding HIV-related mortality, SMRs remained elevated. Decline in SMRs was not linked to drug abuse treatment. CONCLUSIONS: These data demonstrate excess mortality among new-onset IDUs compared with demographically similar peers in the general population, indicating the need for interventions to prevent premature death among young IDUs.