Objective The purpose of the present study is to compare the pharmacokinetic and biodistribution properties of 99Tcm N-mercaptopyridine-N-oxide (99 Tcm N-MPO) with 99 Tcm-sestamibi (99 Tcm-MIBI) in normal dogs, and to investigate the potential of 99TcmN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Methods Twelve healthy mongrel dogs were injected intravenously with 99TcmN-MPO (n = 6) or 99Tcm-MIBI (n = 6). Tracer kinetics in body fluids were determined by collecting blood of 1 ml via a femoral vein catheter at 30 s, 1,2,3,4,5, 10, 20, 30, 40, 60and 90 min post-injection (p. i.). The collected blood samples were weighed and counted for radioactivity in a γ-counter. Anterior and posterior planar γ-camera images were collected at 10, 20, 30, 60, 90, and 120 min after injection, with organ uptake quantified by region-of-interest (ROIs) analysis. For comparison, 99Tcm-MIBI was also evaluated in the same twelve dogs. Canine infarct models were set up by micro-invasive interventional embolization. SPECT images in the canine infarct model were collected 24 hours after myocardial infarction at 30 min and 60 min after the administration of 99Tcm N-MPO (n = 5) or 99Tcm-MIBI (n = 5). Results Both of 99Tcm N-MPO and 99Tcm-M1BI had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min [99TcmN-MPO: (35. 77 ± 6. 31)% ID/mg ,99Tcm-MIBI (34. 46 ± 6. 83) % ID/mg] and less than 5% at 30 min p. i. [99Tcm N-MPO(3. 11 ± 1.44) % ID/mg,99Tcm-MIBI (2.93 ±0. 39)% ID/mg] . After injection, 99TcmN-MPO showed significant accumulation in the myocardium and prolonged retention. This rapid liver clearance of 99TcmN-MPO led to favorable heart-to-liver ratios, reaching values of 0. 54 ±0. 06 at 10 min, 1.02 ±0. 06 at 30 min, and 1.38 ±0. 06 at 60 min p. i.In contrast, the heart/liver ratio of 99Tcm-MIBI remained low at all time points (0. 46 ± 0. 03 at 10 min,0. 63 ±0. 03 at 30 min, and 0. 62 ± 0. 12 at 60 min p. i.). SPECT imaging studies in canines with acute myocardial infarction indicated that good visualization of the left ventricular wall and perfusion defects could be achieved at 30 min after administration of 99TcmN-MPO, but not 99Tcm-MIBI. Conclusion The combination of high heart uptake and rapid liver clearance makes 99TcmN-MPO a promising new radiotracer for myocardial perfusion imaging.

Objective To investigate the effects of Saussurea involucrata extract pretreatment on the expression of the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) in focal cerebral ischemia/reperfusion in mice and its possible neuroprotective mechanism.Methods Seventy-two Kunming mice were randomly divided into four groups:sham operation,saline,Saussurea involucrata extract,and edaravone groups (n =18 in each group).Saussurea involucrata extract 0.8 g/kg was given intraperitoneally in the Saussurea involucrata extract group; edaravone 3 mg/kg was given in the edaravone group; and the same volume of saline was given in the saline group.A model of middle cerebral artery occlusion (MCAO) was induced after 7 days of continuous injection.Cerebral infarct volume was determined by 2,3,5-triphenyltetrazolium staining.Immunohistochemical staining was used to detect TLR4-positive cells in ischemic brain tissue.Reverse transcriptase polymerase chain reaction was used to detect the expression of TLR4/NF-κB mRNA.Results The cerebral infarct volume in mice in the saline,Saussurea involucrata extract and edaravone groups was 131.55± 28.25 mm3,84.10 ±13.92 mm3 and 65.10 ± 6.78 mm3,respectively.There were significant difference (F =10.158,P =0.012).The infarct volume in the Saussurea involucrata extract group (P =0.020) and edaravone group (P0.005) was significantly less than that in the saline group,and there was no significantly difference between the 2 groups.The numbers of cortex and TLR4 positive cells in hippocampus area at the ischemic sides in the saline group were significantly more than those in the sham operation group (all P ＜0.001).The numbers of positive cells of cortex and TLR4 in the Saussurea involucrata extract group and the edaravone group were significantly decreased compared to the saline group (all P ＜ 0.05),and there was no significant differences between the Saussurea involucrata extract group and the edaravone group.The expressions of TLR4,p50,and p65 mRNA in the saline group were significantly up-regulated compared to the sham operation group (all P =0.000).Saussurea involucrata extract could significantly down-regulate the expressions of TLR4,p50,and p65 mRNA at 24 hours after ischemia/reperfusion (all P =0.000).Edaravone could significantly down-regulate the expressions of TLR4 and p65 mRNA (all P =0.000) and it had a down-regulated trend for the expression of p50 mRNA (P =0.053); while there was no significant difference in the expressions of TLR4 and p65 mRNA between the Saussurea involucrata extract group and the edaravone group.Conclusions Saussurea involucrata extract pretreatment may significantly reduce the cerebral infarct volume,down-regulate the expressions of TLR4 and NF-κB subunit,and play a neuroprotective effect by inhibiting inflammatory response after ischemia.

OBJECTIVETo investigate the effects of fluoride on activities of tartrate-resistant acid phosphate (TRAP) and matrix metalloproteinase-9 (MMP-9) in rat osteoclasts cultured in vitro.

METHODSOsteoclast was isolated mechanically from long bones of neonatal rats and cultured in vitro. Histochemical stain was applied to detect the effects of fluoride on activities of TRAP and in-situ hybridization was used to study the expression of MMP-9 mRNA in rat osteoclasts in vitro.

RESULTSNumber of TRAP positive cells was 154.2, 160.0, 170.6, 179.0 and 180.0 per cm(2), respectively for the rats with varied doses of fluoride, in a dose-response pattern but without statistical significance. The expression of MMP-9 mRNA increased with elevating dose of fluoride, especially in the rats with 1.00, 2.00 and 4.00 mg/L of fluoride, to 94.50, 94.64 and 104.97, respectively, significantly different from those in control group.

CONCLUSIONSFluoride can enhance the MMP-9 mRNA expression in cultured osteoclasts of rats.

Acid Phosphatase ; metabolism ; Animals ; Animals, Newborn ; Biomarkers ; Cells, Cultured ; Dose-Response Relationship, Drug ; Fluorides ; pharmacology ; Isoenzymes ; metabolism ; Matrix Metalloproteinase 9 ; biosynthesis ; genetics ; Osteoclasts ; cytology ; drug effects ; enzymology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Tartrate-Resistant Acid Phosphatase

Antibody-drug conjugate (ADC) is a new class of therapeutics composed of a monoclonal antibody and small cytotoxin moieties conjugated through a chemical linker. ADC molecules bind to the target antigens expressed on the tumor cell surfaces guided by the monoclonal antibody component. The binding ADC molecules can be internalized and subsequently the toxin moieties can be released within the tumor cells via chemical and/or enzymatic reactions to kill the target cells. The conjugation combines the merits of both components, i.e., the high target specificity of the monoclonal antibody and the highly potent cell killing activity of the cytotoxin moieties. However, such complexities make the pharmacokinetic and metabolic studies of ADCs highly challenging. The major challenges should include characterization of absorption, distribution, metabolism and excretion, investigation of underlying mechanisms, assessment of pharmacokinetic- pharmacodynamic relationship, and analytical method development of ADC drugs. This review will discuss common pharmacokinetic issues and considerations, as well as tools and strategies that can be utilized to characterize the pharmacokinetic and metabolic properties of ADCs.
Antibodies, Monoclonal ; pharmacokinetics ; Cytotoxins ; pharmacokinetics ; Humans ; Immunoconjugates ; pharmacokinetics ; Neoplasms ; drug therapy

OBJECTIVE: To explore the expression of hypoxia inducible factor-1alpha (HIF-1alpha) and erythropoietin in the hippocampus of aging rats, and to investigate the role of HIF-1alpha and erythropoietin in the aging of nervous system. METHODS: The expression of Nissl body, HIF-1alpha, and erythropoietin in the CA1 region of the hippocampus in different months was observed by Nissl staining and immunohistochemical technique. RESULTS: Nerve cells became bigger and appeared sparse, and the Nissl bodies decreased with age. HIF-1alpha positive cells increased significantly with age in the CA1 region of the hippocampus (P<0.05). The expression of erythropoietin presented a parabola with aging in the CA1 region of the hippocampus. The increase from 3 to 18 months and the reduction from 18 to 30 months of erythropoietin positive cells had statistical significance (both P<0.05). CONCLUSION HIF-1alpha and erythropoietin are parallelly incremental before middle age, and are separated after middle age, suggesting decreased activity of HIF-1alpha and recession of protein synthesis function may be the main reasons for decreased expression of erythropoietin in the brain during aging. Strengthened endogenous HIF-1alpha activity and supply of exogenous erythropoietin may delay the aging of the nervous system.
Aging ; metabolism ; Animals ; Erythropoietin ; metabolism ; Hippocampus ; metabolism ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley

BACKGROUNDThe hematopoietic microenvironment (HM) plays a critical role in malignant cell growth, patient survival, and response to chemotherapy in hematologic malignancies. However, mechanisms associated with this environmental influence remain unclear. In this study, we investigated the role of bone marrow derived mesenchymal stem cells (MSCs) in U937 cell line, to find out the relations between leukemia drug resistance and the MSCs.

METHODSU937 cells were cultured in suspension or grew adherently with MSCs. The cell growth curve was drawn and the cell cycle was measured by flow cytometry. Apoptosis and sensitivity of U937 to daunoblastina (DNR) were quantified by DNA ladder detection and trypan blue exclusion assays, respectively. The gene expression profile chip technology was used to determine and analyze the changes in apoptosis-related gene expression after adherent culture and the expression of MDR1 mRNA was assessed by reverse transcriptional polymerase chain reaction (RT-PCR) at the same time.

RESULTSIn the adherent culture, the proliferation of the U937 cells was inhibited, the G0/G1 phase cells increased (F = 64.9726, P < 0.0001), G2/M phase cells were decreased (F = 98.1361, P < 0.0001) and the natural apoptosis rate was decreased (F = 24.0866, P < 0.0001) compared with those in the suspended culture. U937 cell viability was enhanced and cell apoptosis was blocked during DNR treatment in adherent culture with MSCs. Thirty-nine differently expressed genes were screened from the 487 apoptosis related genes in the adherent culture U937 cells. Among the 37 upregulated genes, Bcl-XL was upregulated most significantly. Two genes were downregulated. Adherent culture did not induce MDR1 mRNA expression in U937 cells.

CONCLUSIONSMSCs play a role in modulating the proliferation of U937 cells and response of U937 cells to DNR, and Bcl-XL apoptosis-inhibiting gene may be most important in determining the sensitivity of leukemic cells to treatment, which is not related to MDR1.

Apoptosis ; drug effects ; Bone Marrow Cells ; physiology ; Cell Proliferation ; Daunorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Genes, MDR ; Humans ; Immunophenotyping ; Mesenchymal Stromal Cells ; physiology ; U937 Cells ; drug effects

OBJECTIVETo compare apoptosis gene expression profiling of U937 cells in suspension culture with that cultivated with mesenchymal stem cells (MSCs), and find out the relationship between drug resistance of leukemia cells and hemopoietic microenvironment.

METHODSU937 cells were cultivated in adhesion culture with MSCs and in suspension culture for 48 hours. Cell cycle was determined by flow cytometry and gene expression profiling by cDNA microarray.

RESULTSCompared with that in suspension, G(0)/G(1) fraction of U937 cells increased in adhesion culture (45.3 +/- 3.1)% vs (32.6 +/- 2.1)%, respectively (P < 0.05), whereas G(2)/M fraction and apoptosis rate were decreased. After 48 h twenty-eight differential expression genes were screened out in 487 apoptosis-related genes, among which 27 were up-regulated and were mainly apoptosis-suppressor genes, apoptosis-promoter genes, cell cycle positive control genes and cell cycle negative control genes. But Bcl-XL was up-regulated most obviously. The only one gene down-regulated was an apoptosis promoter gene.

CONCLUSIONAdhesion culture with MSCs can lead to growth suppression and decrease natural apoptosis of U937 cells. The mechanism was multiple gene effects, but Bcl-XL may be of the most importance.

Apoptosis ; genetics ; Cell Adhesion ; Cell Cycle ; genetics ; Cells, Cultured ; Coculture Techniques ; Flow Cytometry ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; Humans ; Lymphoma, Large B-Cell, Diffuse ; genetics ; pathology ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Oligonucleotide Array Sequence Analysis ; U937 Cells

BACKGROUNDRNA interference using short hairpin RNA (shRNA) can mediate sequence-specific inhibition of gene expression in mammalian cells. A vector-based approach for synthesizing shRNA has been developed recently. Overexpression of P-glycoprotein (P-gp), the MDR1 gene product, confers multidrug resistance (MDR) to cancer cells. In this study, we reversed MDR using shRNA expression vectors in a multidrug-resistant human breast cancer cell line (MCF-7/AdrR).

METHODSThe two shRNA expression vectors were constructed and introduced into MCF-7/AdrR cells. Expression of MDR1 mRNA was assessed by RT-PCR, and P-gp expression was determined by Western Blot and immunocytochemistry. Apoptosis and sensitization of the breast cancer cells to doxorubicin were quantified by flow cytometry and methyl thiazolyl tetrazolium (MTT) assays, respectively. Cellular daunorubicin accumulation was assayed by laser confocal scanning microscopy (LCSM). Statistical significance of differences in mean values was evaluated by Student's t tests. P < 0.05 was considered statistically significant.

RESULTSIn MCF-7/AdrA cells transfected with MDR1-A and MDR1-B shRNA expression vectors, RT-PCR showed that MDR1 mRNA expression was reduced by 40.9% (P < 0.05), 30.1% (P < 0.01) (transient transfection) and 37.6% (P < 0.05), 28.0% (P < 0.01) (stable transfection), respectively. Western Blot and immunocytochemistry showed that P-gp expression was significantly and specifically inhibited. Resistance against doxorubicin was decreased from 162-fold to 109-fold (P < 0.05), 54-fold (P < 0.01) (transient transfection) and to 108-fold (P < 0.05), 50-fold (P < 0.01) (stable transfection). Furthermore, shRNA vectors significantly enhanced the cellular daunorubicin accumulation. The combination of shRNA vectors and doxorubicin significantly induced apoptosis in MCF-7/AdrR cells.

CONCLUSIONSshRNA expression vectors effectively reduce MDR expression in a sustained fashion and can restore the sensitivity of drug-resistant cancer cells to conventional chemotherapeutic agents.

ATP-Binding Cassette, Sub-Family B, Member 1 ; analysis ; antagonists & inhibitors ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Daunorubicin ; pharmacokinetics ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Flow Cytometry ; Genes, MDR ; Genetic Vectors ; Humans ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection

Naoxintong capsule has beneficial effects for activating blood circulation, dispersing blood stasis and dredging collateral. It is widely used in the treatment of coronary heart disease, angina pectoris, stroke and cardiovascular disease. However, the pharmacodynamic basis and possible mechanism of its preventive effects are not clear. In this study, 10 male and 10 female C57BL/6 mice were used, and were randomly divided into the control group (saline) and Naoxintong group. Adaptively fed for 7 days in common conditions, mice were given Naoxintong capsule or saline for 3 days via intragastric administration. Serum was collected from 6 mice in each group 1 h after the last administration. Serum proteins were prepared to do two-dimensional gel electrophoresis. Then image analysis and mass spectrometry detection were carried out to screen and identify the differentially expressed proteins and make bioinformatics analysis. It was found that 24 differentially expressed proteins between Naoxintong group and control group. Compared with the control group, 12 proteins were increased, and 12 were decreased. The proteins were involved in apoptosis signal pathway and vascular endothelial growth factor signal transduction pathway, in which vasohibin-1 is a negative feedback regulation factor in angiogenesis. Western blot showed that the expression of vasohibin-1 in Naoxintong group was reduced, which is consistent with the result in two-dimensional electrophoresis. Serum proteins expression is different between Naoxintong and control groups. The targets of these differentially expressed proteins include endothelial cells, inflammatory cells and platelets. The changes on proteins showed that Naoxintong capsule may ameliorate coronary heart disease and ischemic cerebrovascular disease, and provide potential biological markers to prevent ischemic disease.

Objective: To investigate the clinical features and long-term prognosis of primary biliary cholangitis (PBC) in patients with past hepatitis B virus (HBV) infection. Methods: 353 cases with PBC who visited the Liver Disease Center of Beijing Friendship Hospital Affiliated to Capital Medical University between January 2000 and January 2018 were retrospectively analyzed and were divided into the past HBV infection group (156 cases) and the no HBV infection group (197 cases). The two groups' baseline clinical features were compared. Ursodeoxycholic acid response rate after one year, GLOBE score, UK-PBC score, and long-term liver transplantation-free survival rate were compared through outpatient and telephone follow-up. Results: PBC with past HBV infection had a significantly reduced female proportion compared to the no HBV infection group (91.9% vs. 79.5%, P = 0.001). However, there were no statistically significant differences in age, biochemical indices, immunological indicators, platelet count, cirrhosis proportion, and others. Ursodeoxycholic acid biochemical response rate was reduced in patients with past HBV infection at the end of one year of treatment, but the difference was not statistically significant (65.8% vs. 78.2%, P = 0.068). In addition, there were no statistically significant differences between the GLOBE score (0.57 vs. 0.59, P = 0.26) and UK-PBC 5-year (2.87% vs. 2.87%, P = 0.38), 10-year (9.29% vs. 8.2%, P = 0.39) and 15-year liver transplantation rates (16.6% vs. 14.73%, P = 0.39). Lastly, the overall 5-year liver transplantation-free survival rate had no statistically significant difference between the two groups of patients (86.4% vs. 87.5%, P = 0.796). Conclusion: Primary biliary cholangitis had no discernible effect in terms of age at onset, biochemical indices, immunological indicators, cirrhosis proportion, ursodeoxycholic acid response rate after one year, GLOBE score, UK-PBC score, or overall liver transplantation-free survival rate in patients with past hepatitis B virus infections.