A magnetism/laser-auxiliary cascaded drug delivery to pulmonary carcinoma

Although high-efficiency targeted delivery is investigated for years, the efficiency of tumor targeting seems still a hard core to smash. To overcome this problem, we design a three-step delivery strategy based on streptavidin-biotin interaction with the help of c(RGDfK), magnetic fields and lasers. The ultrasmall superparamagnetic iron oxide nanoparticles (USIONPs) modified with c(RGDfK) and biotin are delivered at step 1, followed by streptavidin and the doxorubicin (Dox) loaded nanosystems conjugated with biotin at steps 2 and 3, respectively. The delivery systems were proved to be efficient on A549 cells. The co-localization of signal for each step revealed the targeting mechanism. The external magnetic field could further amplify the endocytosis of USPIONs based on c(RGDfK), and magnify the uptake distinctions among different test groups. Based on photoacoustic imaging, laser-heating treatment could enhance the permeability of tumor venous blood vessels and change the insufficient blood flow in cancer. Then, it was noticed that only three-step delivery with laser-heating and magnetic fields realized the highest tumor distribution of nanosystem. Finally, the magnetism/laser-auxiliary cascaded delivery exhibited the best antitumor efficacy. Generally, this study demonstrated the necessity of combining physical, biological and chemical means of targeting.

Construction of a new isovalerylspiramycin I producing strain by CRISPR-Cas9 system / 生物工程学报

Isovalerylspiramycin (ISP)Ⅰ, as a major component of bitespiramycin (BT), exhibits similar antimicrobial activities with BT and has advantages in quality control and dosage forms. It has been under preclinical studies. The existing ISPⅠ producing strain, undergoing three genetic modifications, carries two resistant gene markers. Thus, it is hard for further genetic manipulation. It is a time-consuming and unsuccessful work to construct a new ISPⅠ strain without resistant gene marker by means of the classical homologous recombination in our preliminary experiments. Fortunately, construction of the markerless ISPⅠ strain, in which the bsm4 (responsible for acylation at 3 of spiramycin) gene was replaced by the Isovaleryltansferase gene (ist) under control of the constitutive promoter ermEp*, was efficiently achieved by using the CRISPR-Cas9 gene editing system. The mutant of bsm4 deletion can only produce SPⅠ. Isovaleryltransferase coded by ist catalyzes the isovalerylation of the SPⅠat C-4" hydroxyl group to produce ISPⅠ. As anticipated, ISPⅠ was the sole ISP component of the resultant strain (ΔEI) when detected by HPLC and mass spectrometry. The ΔEI mutant is suitable for further genetic engineering to obtain improved strains by reusing CRISPR-Cas9 system.

Recent progress in drug delivery

Drug delivery systems (DDS) are defined as methods by which drugs are delivered to desired tissues, organs, cells and subcellular organs for drug release and absorption through a variety of drug carriers. Its usual purpose to improve the pharmacological activities of therapeutic drugs and to overcome problems such as limited solubility, drug aggregation, low bioavailability, poor biodistribution, lack of selectivity, or to reduce the side effects of therapeutic drugs. During 2015-2018, significant progress in the research on drug delivery systems has been achieved along with advances in related fields, such as pharmaceutical sciences, material sciences and biomedical sciences. This review provides a concise overview of current progress in this research area through its focus on the delivery strategies, construction techniques and specific examples. It is a valuable reference for pharmaceutical scientists who want to learn more about the design of drug delivery systems.

Silencing MR-1 attenuates atherosclerosis in ApoE(−/−) mice induced by angiotensin II through FAK-Akt–mTOR-NF-kappaB signaling pathway

Myofibrillogenesis regulator-1 (MR-1) is a novel protein involved in cellular proliferation, migration, inflammatory reaction and signal transduction. However, little information is available on the relationship between MR-1 expression and the progression of atherosclerosis. Here we report atheroprotective effects of silencing MR-1 in a model of Ang II-accelerated atherosclerosis, characterized by suppression focal adhesion kinase (FAK) and nuclear factor kappaB (NF-κB) signaling pathway, and atherosclerotic lesion macrophage content. In this model, administration of the siRNA-MR-1 substantially attenuated Ang II-accelerated atherosclerosis with stabilization of atherosclerotic plaques and inhibited FAK, Akt, mammalian target of rapamycin (mTOR) and NF-kB activation, which was associated with suppression of inflammatory factor and atherogenic gene expression in the artery. In vitro studies demonstrated similar changes in Ang II-treated vascular smooth muscle cells (VSMCs) and macrophages: siRNA-MR-1 inhibited the expression levels of proinflammatory factor. These studies uncover crucial proinflammatory mechanisms of Ang II and highlight actions of silencing MR-1 to inhibit Ang II signaling, which is atheroprotective.

Analyze of development strategy of Dongfang hospital the clinical medical college of Beijing university of Chinese medicine and the management mode about multi-hospital district / 国际中医中药杂志

Up to 2015, almost all of the Third-grade class-A TCM hospitals in Beijing set up multiple sub-hospitals, under the regional integrating of Beijing-Tianjin-Hebei region, in order to meet regional homogenization of medical and health care demand, to provide high-quality medical service for the patients, and to improve the hospital development in a certain stage. Taking Beijing university of traditional Chinese medicine affiliated Dongfang hospital for example, it creates "two sub-hospitals " a court layout of mode of "one hospital with multiple branches". This article analyzed the sub-hospitals organization structure reform, cost budget control, performance management & personnel training, information system construction, to draw lessons from practical manage experience, and explored the "multiple sub-hospitals " superior management mode for our hospital.

Analyze of development strategy of Dongfang hospital the clinical medical college of Beijing university of Chinese medicine and the management mode about multi-hospital district / 国际中医中药杂志

Up to 2015, almost all of the Third-grade class-A TCM hospitals in Beijing set up multiple sub-hospitals, under the regional integrating of Beijing-Tianjin-Hebei region, in order to meet regional homogenization of medical and health care demand, to provide high-quality medical service for the patients, and to improve the hospital development in a certain stage. Taking Beijing university of traditional Chinese medicine affiliated Dongfang hospital for example, it creates "two sub-hospitals " a court layout of mode of "one hospital with multiple branches". This article analyzed the sub-hospitals organization structure reform, cost budget control, performance management & personnel training, information system construction, to draw lessons from practical manage experience, and explored the "multiple sub-hospitals " superior management mode for our hospital.

Expression of 4"-O-isovaleryltransferase gene from Streptomyces thermotolerans in Streptomyces lividans TK24 / 生物工程学报

4"-O-isovaleryltransferase gene (ist) was regulated by positive regulatory genes of midecamycin 4"-O-propionyltransferase gene (mpt) in Streptomyces lividans TK24. A BamH I ~8.0 kb fragment from Streptomyces mycarofaciens 1748 was proved that it contained mpt gene and linked with two positive regulatory genes, orf27 and orf28. Orf of mpt was replaced by orf of ist and linked with two regulatory genes or orf27 single, and individually cloned into the vectors pKC1139 or pWHM3 (high copy number), and then transformed into S. lividans TK24. The levels of mpt and ist expression were evaluated by the bio-tramsformation efficacy of spiramycin into 4"-O-acylspiramycins in these transformants. The results showed that 4"-O-isovalerylspiramycins could be detected only in the transformants containing the plasmids constructed with pWHM3. The efficacy of bio-transformation of the transformants containing two regulatory genes was higher than that of orf27 single. So, the positive regulatory genes system of mpt gene could enhance ist gene expression.

Study on hepatitis C virus genotyping in guizhou area / 重庆医学

Objective To study the distribution of genotypes of hepatitis C virus in Guizhou and its relationship between infec-tious route of genotype and age ,gender was analyzed .Methods Serum specimens in this study were obtained from 198 patients , whose anti-HCV and HCV RNA were positive .A reverse transcriptase PCR(RT nested-PCR)assay using conserved primers de-duced from the core-envelope 1(C-E1)region of the hepatitis C virus(HCV)genome was employed to amplify a 474-nucleotide-long fragment .Phylogenetic analysis of the C-E1 sequences was conducted by direct sequencing of the RT-PCR products and alignment with published HCV subtypes in GenBank .Subtypes of the samples were determined by nucleotide sequencing followed by composi-tion of a phylogenetic tree .Results Among the 198 patients surveyed ,genotype 1a was detected in 4 cases(2 .0% ) ,genotype 1b in 71 cases(35 .9% ) ,genotype 2a in 9 cases(4 .6% ) ,genotype 3a in 29 cases(14 .7% ) ,genotype 3b in 47 cases(23 .7% ) ,genotype 6 a in 37 cases(18 .7% )and genotype 6d in 1 cases(0 .5% ) .Genotype distribution on gender had no statistical significance(P>0 .05) , and its distribution on people with different ages had statistical significance(P<0 .05) ,and its distribution on patients with different infectious routes was significantly different(P<0 .05) .Conclusion The major genotypes of HCV are 1b ,3b ,6a and 3a in Guizhou , and genotype 1a is predominant .Genotypes 1a ,2a and 6d exist too .Genotypes of patients infected with HCV are related to their in-fectious routes ,and the HCV genotypes are in a great variety .

Identification of tetracenomycin X from a marine-derived Saccharothrix sp. guided by genes sequence analysis / 药学学报

The crude extracts of the fermentation broth from a marine sediment-derived actinomycete strain, Saccharothrix sp. 10-10, showed significant antibacterial activities against drug-resistant pathogens. A genome-mining PCR-based experiment targeting the genes encoding key enzymes involved in the biosynthesis of secondary metabolites indicated that the strain 10-10 showed the potential to produce tetracenomycin-like compounds. Further chemical investigation of the cultures of this strain led to the identification of two antibiotics, including a tetracenomycin (Tcm) analogs, Tcm X (1), and a tomaymycin derivative, oxotomaymycin (2). Their structures were identified by spectroscopic data analysis, including UV, 1D-NMR, 2D-NMR and MS spectra. Tcm X (1) showed moderate antibacterial activities against a number of drug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) pathogens, with the MIC values in the range of 32-64 microg x mL(-1). In addition, 1 also displayed significant cytotoxic activities against human cancer cell lines, including HL60 (leukemia), HepG2 (liver), and MCF-7 (breast) with the IC 50 values of 5.1, 9.7 and 18.0 micromol x L(-1), respectively. Guided by the PCR-based gene sequence analysis, Tcm X (1) and oxotomaymycin (2) were identified from the genus of Saccharothrix and their 13C NMR data were correctly assigned on the basis of 2D NMR spectroscopic data analysis for the first time.

Halogenated natural products from the marine-derived actinobacteria and their halogenation mechanism / 药学学报

In the last decade, along with the development of taxonomy research in marine-derived actinobacteria, more and more halogenated natural products were discovered from marine actinobacteria. Most of them showed good biological activity and unique structure compared to those from land. The special halogenation mechanism in some compounds' biosynthesis has drawn great attention. So in this review, we focus on the halogenated natural products from marine actinobacteria and their halogenation mechanisms.

Rapid identification of elaiophylin from Streptomyces hygroscopicus 17997, a geldanamycin producer / 生物工程学报

To identify the anti-bacterial compound(s) from Streptomyces hygroscopicus 17997, a geldanamycin producer, silica gel thin layer chromatography (TLC) TLC was used to separate the secondary metabolites of S. hygroscopicus 17997. Compound(s) from the silica gel TLC with anti-Gram positive bacteria activity and becoming red upon color reaction by 2.0 mol/L NaOH was analyzed by HPLC. The UV absorption profile and the retention time of a peak of HPLC were identical to those of authentic elaiophylin. A conserved region of dTDP-glucose-4,6-dehydratase (Tgd) gene was amplified by PCR from the genomic DNA of Streptomyces hygroscopicus 17997. DNA sequence analysis of the amplified DNA fragment indicated that it should be the tgd gene of elaiophylin biosynthetic gene cluster. These results implied that the compound in the peak of HPLC was elaiophylin, a macrodiolide antibiotic. The compound was then confirmed to be elaiophylin by LC-(+)-ESI-MS, which revealed that Streptomyces hygroscopicus 17997 was an elaiophylin producer. At the same time, a fast procedure, which consisted of silica gel TLC, color reaction, HPLC, PCR detection and DNA sequence analysis of tgd gene, and LC-(+)-ESI-MS, was established for rapid identification of elaiophylin and its producer.

Analysis of geldanamycin analogues in trace amounts by LC-MS/MS / 生物工程学报

Ansamycins, such as rifamycin and ansamitocin, usually consist of a group of structural similar components. Geldanamycin, a benzenic ansamycin, has been found to consist of four structural similar components. We analyzed the geldanamycin (GDM) preparation from Streptomyces hygroscopicus 17997 by LC-ESI(+)-MS/MS, and discovered five novel and one known GDM analogues in trace amounts. Based on the ESI(+)-MS/MS spectra of these GDM analogues, and the present understanding of GDM biosynthesis, we proposed the possible chemical structures of these GDM analogues. Three novel GDM analogues, all having the same molecular formula of C29H42N2O10, were GDM biosynthetic derivatives with one of the three C-C double bonds between C2-C3, C4-C5 and C8-C9 in GDM changed to mono-hydroxylated C-C single bond. The other two novel GDM analogues, having the same molecular formula of C28H38N2O8, were 17(or 12, or 4)-desmethoxylgeldanamycin and 4,5-dihydro-10,11-dehydrate-17-desmethyl-17-hydroxylgeldanamycin, respectively. The known GDM analogue, having the molecular formula of C29H42N2O9, was 4, 5-dihydrogeldanamycin, an intermediate in GDM biosynthesis. The discovery of novel GDM analogues provided us new insights in understanding the biosynthetic details of GDM, and clues of obtaining GDM derivatives by gene-disruption and combinatorial biosynthesis.

Regulatory genes of geldanamycin biosynthesis / 生物工程学报

Two LAL family regulatory genes, gdmRI and gdmRII, were identified in the geldanamycin biosynthetic gene cluster of Streptomyces hygroscopicus 17997. Disruption of the two regulatory genes resulted in absolute elimination of geldanamycin biosynthesis. The complementation experiments using a single wild-type gene could restore geldanamycin production. These results indicated that both gdmRI and gdmRII were positive regulatory genes of the geldanamycin biosynthesis.

Roles of geldanamycin biosynthetic genes in Streptomyces hygroscopicus 17997 / 生物工程学报

Geldanamycin (Gdm), an inhibitor of heat shock protein 90 (Hsp90), shows antitumor and antivirus bioactivity. Most Geldanamycin biosynthetic genes have been cloned from the genome library of Streptomyces hygroscopicus 17997. In this report, polyketide synthase (pks) gene, mono-oxygenase (gdmM) gene and carbamoyltransferase gene (gdmN) were subjected to inactivation. Three gene disrupted mutants (deltapks, deltagdmM and deltagdmN) were obtained by double crossover. No Geldanamycin production was detected in three mutant strains cultured in fermentation broth. Gene complementation experiments excluded the possible polar effect of gene disruption on other genes. These results confirmed that pks, gdmM and gdmN genes were essential for Geldanamycin biosynthesis.

Acylation specificity of midecamycin 3-O-acyltransferase within Streptomyces spiramyceticus F21 / 生物工程学报

Spiramycin and midecamycin are 16-membered macrolide antibiotics with very similar chemical structures. Spiramycin has three components, namely spiramycin I, II and III. Spiramycin II and III are, respectively, the O-acetyl and propionyl derivatives at C3-hydroxyl group of spiramycin I. Midecamycin has four components, and the C3-hydroxyl group of midecamycin is all O-propionylated. The enzyme adding acyl group(s) at the C3-hydroxyl group during the biosynthesis of spiramycin and midecamycin is 3-O-acyltransferase. The 3-O-acyltransferases for spiramycin and midecamycin are also very similar, and presume to function when exchanged. To explore whether the 3-O-acyltransferase for midecamycin biosynthesis hold still the character of selective and efficient propionylation for spiramycin I at its C3-hydroxyl group, we inserted mdmB, the 3-O-acyltransferase gene from Streptomyces mycarofaciens ATCC 21454 for midecamycin biosynthesis, into a mutant strain of S. spiramyceticus F21, in which the 3-O-acyltransferase gene for spiramycin biosynthesis, sspA, was deleted; and the mdmB was integrated exactly into the chromosomal site where the sspA was deleted. We name this "hybrid" strain as SP-mdmB. HPLC analysis of the spiramycin produced by SP-mdmB showed that spiramycin I was still the major component, although the relative proportions of both spiramycin II and III increased significantly. We thus conclude that MdmB from Streptomyces mycarofaciens ATCC 21454 for midecamyicn biosynthesis do not hold the character of selective and efficient propionylation for spiramycin I within S. spiramyceticus F21, and this character is possibly limited in Streptomyces mycarofaciens ATCC 21454 for midecamycin biosynthesis.

Effects of Naotong oral solution on acute cerebral infarction in rats / 中国康复理论与实践

@# ObjectiveTo observe effects of Naotong(NT) oral solution on the somatosensory evoked potentials(SEP) of acute cerebral infarction rats and its curative experimental.Methods24 model rats were randomly divided into three groups and treated with NT oral solution,Naoxuekang(NXK) and normal saline(NS) respectively for 20 days,the SEP and neurologic grades of the rat models were evaluated before and after treatment.ResultsAll the latencies of SEP(P1,N2,P2) in NT group was shorter than that of the pre-treatment and NS control group(P<0.01).The neurologic grades of both NT and NXK groups were highly lowered compared with pre-treatment and NS control group(both P<0.05).The latencies of SEP in the model rats were highly correlated with the neurologic grades(r=0.97～0.99,P<0.05～0.01).ConclusionNT can accelerate the nervous function recovery of the rat models with acute cerebral infarction.SEP may be used as a powerful index of observation on curative effect of acute cerebral infarction.

Role of the rostral ventrolateral medulla in pressor response of lateral hypothalamus-perifornical region to glutamate in rats / 中国康复理论与实践

@#ObjectiveTo investigate the effect and mechanisms of rostral ventrolateral medulla (RVL) on the pressor response of lateral hypothalamus-perifornical region (LH/PF) in rats.Methods30 healthy Wistar rats were randomly divided into four groups: the phentolamine group; propranolol group; atropine group and glutamate diethyl ester group, saline was as the control in every group. After microinjection of Glu into LH/PF, the blood pressure and heart rate were observed. Then phentolamine, propranolol, atropine and glutamate diethyl ester were microinjected into RVL and the blood pressure and heart rate changes induced by microinjection of Glu were observed again.ResultsMicroinjection of Glu into LH/PF can cause the blood pressure elevating and heart rate accelerating. The pressor response of Glu to excited LH/PF could be attenuated after response of phentolamine, propranolol, atropine and glutamate diethyl ester microinjected into RVL. The blood pressures of phentolamine group; propranolol group; atropine group and glutamate diethyl ester group reduced significantly different from those in the saline control group (P<0.01).ConclusionThe α-,β-,M- and Glu-receptors in the RVL induce the pressor response of LH/PF region.

Effects of nerve growth factor on the nerve function and nitric oxide synthase to acute cerebral embolism in rats / 中国康复理论与实践

@# ObjectiveTo observe the curative effects of nerve growth factor (NGF) on experimental acute cerebral thromboemblia rats and study the mechanisms preliminarily.Methods24 model rats were randomly divided into three groups treated respectively with NGF, citicoline sodium (CS) and normal saline (NS) for 20 days, and the neurological grades of animals were observed before and after treatment. Then, 55 rats were randomly divided into three groups: the treated group (25 model rats, treated with NGF), control group (25 model rats, treated with NS) and normal group (5 normal rats, without treatment), the levels of nitric oxide synthase (NOS) of all animals were measured at 1 h, 3 h, 6 h, 12 h and 24 h after acute cerebral thromboemblia established.ResultsThe neurological grades of both NGF and CS treated groups were significantly lowered after treatment compared with NS control group ( P<0.05). NOS levels of cerebral thromboemblia areas were higher than that in the control group 1 hour, 3 hours after acute cerebral thromboemblia, the levels of NOS in NGF treatment group were obviously lower than that in the control group post-traumatic 1 hour, 3 hours and 6 hours.ConclusionNGF can accelerate the nervous function recovery of the rat with acute cerebral thromboemblia, the mechanisms is that NGF prohibits neurotoxicity of NOS.

The mechanism of resistance of Pseudomonas aeruginosa to beta-lactam antibiotics and clinical significance / 华中科技大学学报（医学）（英德文版）

To study the resistant mechanism and clinical significance of pseudomonas aeruginosa to beta-lactam antibiotics, the outer membrane permeability rate of 30 P. aeruginosa strains to 5 beta-lactam antibiotics was measured and their production of beta-lactamase and the beta-lactamase genes they carried detected. Furthermore, the relationship between the permeability, beta-lactamase and the clinical effects of beta-lactam antibiotics was observed. By using 14C-penicillin and liquid-scintillant isotope assay, the affinity of penicillin binding proteins (PBPS) was measured and their roles in the resistant mechanism studied. It was revealed that the permeability rate was higher in sensitive strains than in resistant ones (P < 0.05). All strains harbored 1-4 beta-lactamase genes and produced beta-lactamase. Higher permeability rate and higher degree of stability to beta-lactamase indicated better clinical therapeutic effects. The affinity of PBPs changed little without regard to the permeability and beta-lactamase. These results suggested that the permeability of outer membrane and beta-lactamase, but not PBPs, played important roles in the resistant mechanism of P. aeruginosa to beta-lactam antibiotics and affected the clinical therapeutic effectiveness of some patients.

The mechanism of resistance of Pseudomonas aeruginosa to beta-lactam antibiotics and clinical significance / 华中科技大学学报（医学）（英德文版）

To study the resistant mechanism and clinical significance of pseudomonas aeruginosa to beta-lactam antibiotics, the outer membrane permeability rate of 30 P. aeruginosa strains to 5 beta-lactam antibiotics was measured and their production of beta-lactamase and the beta-lactamase genes they carried detected. Furthermore, the relationship between the permeability, beta-lactamase and the clinical effects of beta-lactam antibiotics was observed. By using 14C-penicillin and liquid-scintillant isotope assay, the affinity of penicillin binding proteins (PBPS) was measured and their roles in the resistant mechanism studied. It was revealed that the permeability rate was higher in sensitive strains than in resistant ones (P < 0.05). All strains harbored 1-4 beta-lactamase genes and produced beta-lactamase. Higher permeability rate and higher degree of stability to beta-lactamase indicated better clinical therapeutic effects. The affinity of PBPs changed little without regard to the permeability and beta-lactamase. These results suggested that the permeability of outer membrane and beta-lactamase, but not PBPs, played important roles in the resistant mechanism of P. aeruginosa to beta-lactam antibiotics and affected the clinical therapeutic effectiveness of some patients.