Melatonin receptor agonist neu-pll improves insulin resistance in T2DM rats / 中国药理学通报

Aim To study the effect of melatonin receptor agonist Neu-pl 1 on IR in T2DM rats and to predict its possible mechanism. Methods Long-term high-fat feeding plus low-dose streptozotocin (STZ, 30 mg • kg"1, IP) were used to induce an animal model of type 2 diabetes in female rats. After 4 weeks of intragastric administration, liver tissue was sacrificed. Hie mRNA expression levels of Sirtl, Nrf-1/2 and ERRa in rats were determined by RT-PCR. The relative expressions of PGC-la and Mfn2 were determined by Western blot. Rat INS was measured and HOME-IR and ISI were calculated. The liver ATP content and ATPase activity were measured. Results Compared with normal group, T2DM rats developed IR, PGC-la, Mfn2 protein expression increased, Sirtl and other mRNA expression decreased significantly, ERRa mRNA expression increased, ATP content decreased significantly, and ATPase activity decreased. Compared with model group, the Neu-pll low-dose group reduced INS in T2DM rats, improved IR in T2DM rats, up-regulated rat liver protein and mRNA expression, down-regulated ERRa mRNA expression, and increased rat liver ATP content and ATPase activity. Conclusions The melatonin receptor agonist Neu-pl 1 may improve IR by regulating the mitochondrial bal-ance-related factors in liver of T2DM rats and maintaining normal mitochondrial function.

Study on Preparation and Antitumor Activity of Adriamycin-loaded PLGA-PLL-PEG Nanoparticles / 中国药房

OBJECTIVE:To prepare adriamycin-loaded PLGA-PLL-PEG nanoparticles,and study its antitumor activity. METH-ODS:PLGA-PLL-PEG with the polymerization of PLGA-PLL and activated polyethylene glycol was used as carrier for adriamy-cin,and adriamycin-loaded PLGA-PLL-PEG nanoparticles were prepared. The shape size,particle size distribution,adriamycin con-tent of nanoparticles were detected,drug loading and encapsulation efficiency were calculated. Cumulative release rate (Q) of nanoparticles and adriamycin within 144 h and its proliferation inhibition rate on breast cancer HeLa cells were compared,and half inhibitory rate (IC50) was calculated. RESULTS:Prepared adriamycin-loaded PLGA-PLL-PEG nanoparticles were regular circular with good dispersion and no adhesion. The average particle size was (136.7 ± 9.3) nm (n=5),average encapsulation efficiency was(76.67±8.63)%,average drug loading was(3.86±0.55)%(n=3). Q12 h of adriamycin had reached 100%;Q12 h of adriamy-cin-loaded PLGA-PLL-PEG nanoparticles was 52.9%,Q144 h was 81.2%. The inhibitory rate of adriamycin-loaded PLGA-PLL-PEG nanoparticles on HeLa cells increased slowly than adriamycin;IC50 were 1.844,0.345 μg/mL,respectively. CONCLUSIONS:Adri-amycin-loaded PLGA-PLL-PEG nanoparticles are prepared successfully,showing good sustained-release effect and more significant inhibitory effect than adriamycin.

Prepraration of PLGA-PLL-PEG Nanoparticles Simultaneously Loaded with Daunorubicin and Tetrandrine / 中国药学杂志

OBJECTIVE: To prepare PLGA-PLL-PEG nanoparticles simultaneously loaded with daunorubicin (DNR) and tetrandrine (Tet).

Effect of Active Noise Cancelling Earphones on Preferred Listening Level When Listening to Portable Music Players in Noisy Environments / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Active noise cancelling (ANC) is a technology that can reduce external noise by producing a signal that is similar to noise but different in that it has an opposite phase to noise. Nowadays ANC has become an important technology in the field of hearing aids, but many studies have not focused on the effect of ANC of earphones when listening to portable music players. In this study, we aimed to evaluate whether ANC earphones can effectively reduce external noise and lower the preferred listening level. SUBJECTS AND METHOD: Three different earphones (Ear-canal, On-the-ear, Covering-the-ear) were tested in three different noise environments. Nine participants were tested in 10 experiments. First, through the real ear measurement (REM) system, we evaluated the differences in sound pressure level when the ANC was either turned on or off. Second, we evaluated the effects of ANC on Preferred Listening Level (PLL) for participants listening to the same song with different earphones. Through the REM system, we evaluate the level of sound pressure level when participants controlled the volume and felt most comfortable with the volume level. RESULTS: All three types of earphones showed statistically significant effects on noise reduction when ANC was turned on. The noise reduction effect was most prominent with the Ear-canal earphone. All three types of earphones also showed statistically significant effect on PLL reduction. CONCLUSION: ANC earphones may be helpful in noise reduction and preventing noise induced hearing loss when listening to music in noisy environments. Among the three types of earphones, Ear-canal earphone seems to be the most effective in noise reduction.

The Influence of PEG Modification on EGF-PLL Binding Capacities to EGFR / 生物化学与生物物理进展

Cationic polymers are being developed quickly as gene delivery vectors. For in vivo gene delivery, the cationic polymers are usually further modified by hydrophilic polymer grafting or ligand conjugation, which have been shown to increase the vector stability, gene delivery efficiency and specificity greatly. Some previous research had shown that modified hydrophilic polymer may partly shield the targeting ligand and result in poor delivery specificity. Developing a method to evaluate the influence of PEG modification on targeting delivery is particularly critical to cationic polymer design and gene therapy development. One of most commonly used cationic polymer polylysine (PLL) was chosen as a model. Targeting ligand epidermal growth factor(EGF)was conjugated with PLL to form PLL-EGF. Then hydrophilic polymer polyethylene glycol (PEG) with molecular mass 7 000 and 20 000 were used to modify PLL-EGF respectively to generate PEG7000-g-PLL-EGF and PEG20000-g-PLL-EGF. In BIAcore experiments, epidermal growth factor receptor (EGFR) was conjugated onto BIAcore chip and various PEG modified PLL-EGF solutions were flowed over the chip. By observing the change of RU value, the specific interaction of EGF to EGFR was compared. Compared with PLL-EGF, PEG modified PLL-EGF showed lower association rate and higher disassociation rate to EGFR. Furthermore, compared to PEG7000 modified PLL-EGF, PEG20000 modified PLL-EGF got lower association rate and higher disassociation rate to EGFR. The Scatchard analysis results showed that the interactions between EGFR and PLL-EGF or PEG-PLL-EGF are non-linear. It can be concluded that PEG modification indeed reduced the association rate and enhanced the dissociation rate of EGF to EGFR. The length of PEG chain was also a key factor to influence interaction between ligand and receptor. The results showed that it was critical important to evaluate the influence of PEG modification on delivery specificities. The BIAcore method developed in this paper can successfully evaluate the influence, which would be important for cationic polymer design and its application as potential non-viral gene delivery vectors.

Consistent and Specific Suppression of Mucin Release from Cultured Hamster Tracheal Surface Epithelial Cells by Poly-L-Lysine

Poly-L-lysine (PLL) was reported to suppress mucin release from airway goblet cells during 30 min treatment period. In this study, we investigated whether PLL consistently suppresses mucin release from cultured airway goblet cells during 24 h after 30 min treatment and also specifically suppresses the release of mucin without any effects on the other releasable glycoproteins. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with 3H-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of PLL to assess the effects on 3H-mucin release and on the total elution profile of the treated culture medium. The total mucin content during 24 h after 30 min treatment of PLL was assesed to investigate the consistency of effects. PLL did not affect the release of the other releasable glycoproteins whose molecular weights were less than mucin, and decreased the total mucin content during 24 h after 30 min treatment. We conclude that PLL can specifically suppress mucin release from cultured airway goblet cells and the suppression on mucin release is consistent. This finding suggests that PLL might be used as a specific airway mucin-regulating agent by directly acting on airway mucin-secreting cells.

Research and realization of ECG monitoring system against high-frequency interference by electrosurgical unit / 医疗卫生装备

In modern surgeries, ESU is an important electrosurgical equipment. However, the interference caused by ESU usually affects real-time monitoring of the patient. To solve these problems, the paper introduces some new ideas in analog circuits. To the problem of interference and base-line excursion, this paper proposes an adaptive comb filter with Phase-Locked Loop(PLL), besides digital comb filters. Following the frequency of power and sampling accordingly, this method could easily clear the interference, which could make the cost reduced.