Multidrug resistance (MDR), which significantly decreases the efficacy of anticancer drugs and causes tumor recurrence, has been a major challenge in clinical cancer treatment with chemotherapeutic drugs for decades. Several mechanisms of overcoming drug resistance have been postulated. Well known P-glycoprotein (P-gp) and other drug efflux transporters are considered to be critical in pumping anticancer drugs out of cells and causing chemotherapy failure. Innovative theranostic (therapeutic and diagnostic) strategies with nanoparticles are rapidly evolving and are anticipated to offer opportunities to overcome these limits. In this review, we discuss the mechanisms of drug efflux-mediated resistance and the application of multiple nanoparticle-based platforms to overcome chemoresistance and improve therapeutic outcome.
ATP Binding Cassette Transporter, Sub-Family B ; metabolism ; ATP-Binding Cassette Transporters ; metabolism ; Animals ; Antineoplastic Agents ; therapeutic use ; Drug Delivery Systems ; methods ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Humans ; Molecular Targeted Therapy ; Nanomedicine ; Nanoparticles ; therapeutic use ; Nanotechnology ; Neoplasms ; drug therapy ; metabolism

OBJECTIVETo explore the feasibility of inducing human umbilical cord mesenchymal stem cells (HuMSCs) to differentiate into Leydig cells through conditioned medium derived from Leydig cells.

METHODSHuMSCs and Leydig cells were obtained by tissue blocks culture attachment and enzymatic digestion respectively. HuMSCs were induced by conditioned medium of Leydig cells as an experiment group while those before induction were cultured as a control group. The expressions of LHR, 3β-HSD and StAR in the induced HuMSCs were determined by RT-PCR after 3, 7 and 10 days of culture; those of CYP11A1, CYP17A1 and 3β-HSD measured by immunofluorescence staining after 2 weeks; and that of 3β-HSD detected by Western blot after 4 weeks.

RESULTSThe experimental group showed positively expressed LHR, 3β-HSD and StAR at 3, 7 and 10 days, CYP11A1, CYP17A1 and 3β-HSD at 2 weeks, and 3β-HSD at 4 weeks, while the control group revealed negative expressions at all the time points.

CONCLUSIONInduced with conditioned culture medium derived from Leydig cells, HuMSCs are likely to differentiate into steroidogenic cells and eventually into Leydig cells.

Cell Differentiation ; Culture Media, Conditioned ; Humans ; Leydig Cells ; cytology ; Male ; Mesenchymal Stromal Cells ; cytology ; Umbilical Cord ; cytology

The chemical constituents of 95% ethanol extract of Melastoma dodecandrum were isolated and purified by chromatography on silica gel, Sephadex LH-20, and HPLC, to obtain thirteen compounds eventually. On the basis of their physico-chemical properties and spectroscopic data, these compounds were identified as quercetin (1), quercetin-3-O-β-D-glucopyranoside (2), quercetin-3-O-(6"-O-p-coumaroyl) -β-D-glucopyranoside (3), kaempferol (4), kaempferol-3-O-β-D-glucopyranoside (5), kaempferol-3-O- [2",6"-di-O-(E)-coumaroyl]-β-D-glucopyra-noside (6), luteolin (7), luteolin-7-O-(6"-p-coumaroyl) -β-D-glucopyranoside (8), apigenin (9), apigenin-7-(6"-acetyl-glucopyranoside) (10) , naringenin (11), isovitexin (12), and epicatechin-[8,7-e] -4β-(4-hydroxyphenyl)-3,4-dyhydroxyl-2(3H)-pyranone (13). Eight compounds(3,5,6,8-11 and 13) were obtained from M. dodecandrum for the first time.
Apigenin ; analysis ; Chromatography ; methods ; Chromatography, High Pressure Liquid ; Dextrans ; Flavanones ; analysis ; Flavonoids ; analysis ; chemistry ; Glycosides ; analysis ; chemistry ; Kaempferols ; analysis ; Luteolin ; analysis ; Magnoliopsida ; chemistry ; Plants, Medicinal ; chemistry ; Quercetin ; analysis ; Silica Gel

OBJECTIVETo observe the expression and clinical implication of receptor for activated C kinase 1 (RACK1) in mononuclear cells and coronary atherosclerotic plaques from patients with coronary artery disease.

METHODSmRNA and protein expressions of RACK1 were detected in mononuclear cells from 29 patients with stable angina pectoris (SAP), 41 patients with acute coronary syndrome (ACS) and 30 healthy volunteers. RACK1 protein expression was also detected by immunohistochemistry in 17 coronary atherosclerotic plaques and 6 normal autopsy coronary samples.

RESULTS(1) mRNA expression of RACK1 was significantly upregulated in mononuclear cells from patients with ACS compared with those from patients with SAP (18.71 ± 5.45 vs. 12.18 ± 4.14, P < 0.05), and the latter was also significantly higher than in healthy controls (12.18 ± 4.14 vs. 3.65 ± 1.57, P < 0.05). (2) Similar changes were observed for protein expression of RACK1 for the three groups. (3) Increased expression of RACK1 was found in atherosclerotic plaques, especially in unstable plaques, positive RACK1 stain was evidenced in foam cells, inflammatory cells, smooth muscle cells and endothelial cells.

CONCLUSIONSThe expression of RACK1 is significantly upregulated in mononuclear cells from patients with coronary artery disease, especially in patients with ACS, and in coronary atherosclerotic plaques, especially in unstable plaques. Our results thus suggest that RACK1 might play an important role in the development and progression of coronary artery disease.

Adult ; Aged ; Case-Control Studies ; Coronary Artery Disease ; blood ; genetics ; pathology ; Female ; Gene Expression ; Humans ; Leukocytes ; metabolism ; Male ; Middle Aged ; Receptors for Activated C Kinase ; Receptors, Cell Surface ; genetics ; metabolism

AIMTo investigate the changes of the brain NSE, S100 and ultrastructure and effect of ligustrazine in rats of chronic hypoxia and hypercapnia.

METHODSThirty rats were randomly divided into three groups: control group (A), hypoxia hypercapnia group (B), hypoxia hypercapnia added ligustrazine group (C). The brain NSE, S100 and ultrastructure were observed in rats using the technique of immunohistochemistry and electronic microscope.

RESULTS(1) The mPAP was significantly higher in rats of group B than that of group A and it was much lower in rats of group C than that of group B. Differences of mCAP were not significant in three groups. (2) Serum NO of group B was significantly lower than that of group A, Serum NO of group C was higher than that of group B. (3) Immunohistochemistry showed the average value of integral light density (LD) of NSE and S100 was significantly much lower in rats of group B than that of group A and it was higher in rats of group C than that of group B. (4) The neuron and astrocyte of group B showed vacuolar degeneration and the myelin sheath showed separate. Damage of neuron is alleviated in rats of group C.

CONCLUSIONThe hypoxia hypercapnia could induce damage of neuron and astrocyte in rats. The ligustrazine may be useful in protecting against hypoxia hypercapnia brain damage.

Animals ; Brain ; drug effects ; metabolism ; pathology ; Hypercapnia ; metabolism ; Hypoxia, Brain ; metabolism ; physiopathology ; Male ; Nitric Oxide ; blood ; Pyrazines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; S100 Proteins ; metabolism

OBJECTIVEThe expression of hepatic lipopolysaccharide (LPS) receptors in a rat nonalcoholic steatohepatitis (NASH) model was studied in order to explore the pathogenesis of NASH.

METHODSForty-five male SD rats were fed with a high fat diet. These rats were sacrificed after high fat feeding at 8, 12, 16, 24 weeks. Hepatic expressions of CD14 were observed by immunohistochemistry and expressions of TLR4 were detected by RT-PCR. Hepatic expressions and serum levels of TNFa were measured by RT-PCR and ELISA. Some rats fed with normal rat food served as controls.

RESULTSAt the 8th week fatty livers appeared, and hepatic expressions of CD14 (25.9+/-1.9) and TLR4mRNA (1.75+/-0.81) were upregulated compared to those in the control group (25.9+/-1.9 vs 12.4+/-0.7, 1.75+/-0.81 vs 0.98+/-0.33, P < 0.01, t > 2.756 and P < 0.05, t > 2.045). The hepatic expressions of the two kinds of receptors increased with the appearance of NASH at week 12 (61.8+/-1.9 and 1.88+/-0.72, P < 0.01, t > 2.756 and P < 0.05, t > 2.045), They reached to their peaks at week 16 (71.5+/-1.3 and 5.64+/-0.87, both P < 0.01 and t > 2.756), and decreased slightly at week 24 (67.7+/-6.6 and 4.98+/-0.72, both P < 0.01 and t > 2.756). Hepatic expressions and serum levels of TNFa also increased starting at week 8, and remained at that high level from week 8 to week 24.

CONCLUSIONThe hepatic expressions of CD14 and TLR4 were up-regulated gradually in the established rat NASH model. It may be one of the factors responsible for the increase of hepatic sensitivity to LPS injury of the NASH rats and may play an important role in the pathogenesis of NASH.

Animals ; Fatty Liver ; metabolism ; Lipopolysaccharide Receptors ; metabolism ; Liver ; metabolism ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; metabolism ; Up-Regulation

AIMTo study the effect of Safflower injection (a compound of Chinese Traditional medicine) on pulmonary hypertension in rat during chronic hypoxia and hypercapnia.

METHODSSprague-Dawley rats were randomly divided into normal control group (A), hypoxic hypercapnic group (B), hypoxic hypercapnia + Safflower injection group (C). The concentration of TXB2 and 6-keto-PGF18 in plasma and in lung homogenate were detected by the radioimmunoassay.

RESULTS(1) mPAP, weight ratio of right ventricle (RV) to left ventricle plus septum (LV + S) were much higher in rats of hypoxic hypercapnic group than those of control group. Differences of mCAP among the three groups were not significant. (2) The concentration of TXB2 and the ratio of TXB2/6-keto-PGF1a were significantly higher in rats of B group than those of A and C group. (3) The results examined by light microscopy showed that WA/TA (vessel wall area/total area), SMC (the density of medial smooth muscle cell) and PAMT (the thickness of medial smooth cell layer) were significantly higher in rats of B group than those of A and C group. (4) The results examined by electron microscopy showed proliferation of medial smooth muscle cells and collagen fibers of pulmonary arterioles in rats of B group, and Safflower injection could reverse the changes mentioned above.

CONCLUSIONSafflower injection may inhibit hypoxic hypercapnia pulmonary hypertension and pulmonary vessel remodeling by decreasing the ratio of TXB2/6-keto-PGF1a.

6-Ketoprostaglandin F1 alpha ; metabolism ; Animals ; Carthamus tinctorius ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; Hypercapnia ; metabolism ; pathology ; physiopathology ; Hypertension, Pulmonary ; prevention & control ; Hypoxia ; metabolism ; pathology ; physiopathology ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Thromboxane B2 ; metabolism

Animals ; Cytokines ; blood ; Endotoxins ; toxicity ; Fatty Liver ; chemically induced ; Liver Failure, Acute ; chemically induced ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo detect the level and dynamic change of severe acute respiratory syndrome (SARS)-coronavirus-specific IgG antibody in conavalescent SARS patients, and to provide information for prevention and vaccine development.

METHODSIgG antibody against coronavirus was detected by ELISA in the blood of 311 convalescent SARS patients for every 2 - 4 weeks. Stata 7.0 statistics software was used to analyse the results.

RESULTSIgG antibody was detected positive on each testing of all the convalescent patients and its peak appeared 35 days after recovery. IgG antibody level showed a 35.8% decrease within one year.

CONCLUSIONData showed that all the SARS convalescent patients had generated high level of specific IgG antibody against coronavirus in the early stage of recovery, but the antibody level declined along with the progress of convalescence, suggesting that the detection of the IgG antibody should go on until it disappeared.

Adolescent ; Adult ; Aged ; Antibodies, Viral ; blood ; Convalescence ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin G ; blood ; Male ; Middle Aged ; SARS Virus ; immunology ; Severe Acute Respiratory Syndrome ; immunology

OBJECTIVETo observe the effect of transcutaneous electrical acupoint stimulation (TEAS) on nausea and vomiting (N&V) induced by patient controlled intravenous analgesia (PCIA) with Tramadol.

METHODSSixty patients who were ready to receive scheduled operation for tumor in the head-neck region and post-operation PCIA, aged 39-65 years, with the physique grades I-II of ASA, were randomized into two groups, A and B, 30 in each group. The pre-operation medication, induction of analgesia and continuous anesthesia used in the two groups were the same. TEAS on bilateral Hegu (LI4) and Neiguan (PC6) points was intermittently applied to the patients in group A starting from 30 min before analgesia induction to 24 h after operation, and the incidence and score of nausea and vomiting, antiemetic used, visual analogue scores (VAS), and PCIA pressing times in 4 time segments (0-4, 4-8, 8-12 and 12-24 h after the operation was finished) were determined. The same management was applied to patients in Group B, with sham TEAS for control.

RESULTSThe incidence and degree of N&V, as well as the number of patients who needed remedial antiemetic in Group A were less than those in Group B. The VAS score and PCIA pressing time were lower in Group A than those in Group B in the corresponding time segments respectively.

CONCLUSIONTEAS could prevent N&V induced by PCIA with Tramadol.

Acupuncture Points ; Adult ; Aged ; Analgesia, Patient-Controlled ; Analgesics, Opioid ; adverse effects ; Female ; Humans ; Male ; Middle Aged ; Nausea ; prevention & control ; Tramadol ; adverse effects ; Transcutaneous Electric Nerve Stimulation ; Vomiting ; prevention & control