ABSTRACT
Objective@#To assess the superiority of 99Tcm-3SPboroxime (99Tcm-3SP for short) as a fast-myocardial perfusion imaging (MPI) tracer in normal and acute myocardial infarction (AMI) mini-swine.@*Methods@#99Tcm-3SP and 99Tcm-Teboroxime (99Tcm-TEBO for short) were prepared. Approximately 370 MBq 99Tcm-3SP or 99Tcm-TEBO was injected intravenously in 2 healthy mini-swine separately. Dynamic planar images were acquired immediately after injection and continued for 20 min using a standard SPECT camera. The radioactivity uptakes in the heart, liver, and lungs were measured, and heart/liver and heart/lung ratios over time were calculated. Dynamic SPECT studies were performed in 4 normal swine and 1 AMI-swine using cadmium zinc telluride-SPECT (CZT-SPECT). List mode acquisitions were immediately started and continued for 15 min after intravenous injection of approximately 370 MBq 99Tcm-TEBO and 99Tcm-3SP. The injection of two radiotracers in the same swine was completed within 2 d. The radioactivity uptakes in heart and liver were measured, and heart/liver ratio was calculated. Image quality was also evaluated. Paired t test was used to analyze the data.@*Results@#The radiochemical purity of 99Tcm-TEBO or 99Tcm-3SP were both above 95%. The initial heart uptake of 99Tcm-3SP was very close to that of 99Tcm-TEBO (planar image, 2 min postinjection: 309.32×103 vs 314.13×103 counts/MBq; SPECT image, 2 min postinjection (corrected): 7.96±0.87 vs 8.24±1.53, t=0.277, P>0.05), but the myocardial retention time was much longer than that of 99Tcm-TEBO (planar image, 20 min postinjection: 218.67×103 vs 143.19×103 counts/MBq; SPECT image, 15 min postinjection (corrected): 6.76±0.45 vs 5.06±0.33, t=-12.412, P=0.001). The uptake of liver and heart/liver ratio between 99Tcm-TEBO and 99Tcm-3SP were similar (t values: -1.332-1.101, all P>0.05 within 15 min). SPECT MPI images demonstrated uniform tracer distribution with clearly visualizable myocardial boundary in normal myocardium and intense perfusion defect in infarct myocardium. High quality SPECT images could be obtained in any of the 5 min imaging windows over the first 15 min after injection of 99Tcm-3SP in normal swine and AMI-swine.@*Conclusion@#99Tcm-3SP is a promising 99Tcm-labeled radiotracer for fast-MPI considering its high heart uptake, long myocardial retention time (20 min postinjection) and superior SPECT image quality.
ABSTRACT
Objective To assess the superiority of 99Tcm-3SPboroxime (99Tcm-3SP for short) as a fast-myocardial perfusion imaging (MPI) tracer in normal and acute myocardial infarction (AMI) mini-swine.Methods 99Tcm-3SP and 99Tcm-Teboroxime (99Tcm-TEBO for short) were prepared.Approximately 370 MBq 99Tcm-3SP or 99Tcm-TEBO was injected intravenously in 2 healthy mini-swine separately.Dynamic planar images were acquired immediately after injection and continued for 20 min using a standard SPECT camera.The radioactivity uptakes in the heart,liver,and lungs were measured,and heart/liver and heart/lung ratios over time were calculated.Dynamic SPECT studies were performed in 4 normal swine and 1 AMI-swine using cadmium zinc telluride-SPECT (CZT-SPECT).List mode acquisitions were immediately started and continued for 15 min after intravenous injection of approximately 370 MBq 99Tcm-TEBO and 99Tcm-3SP.The injection of two radiotracers in the same swine was completed within 2 d.The radioactivity uptakes in heart and liver were measured,and heart/liver ratio was calculated.Image quality was also evaluated.Paired t test was used to analyze the data.Results The radiochemical purity of 99Tcm-TEBO or 99Tcm-3SP were both above 95％.The initial heart uptake of 99Tcm-3SP was very close to that of 99Tcm-TEBO (planar image,2 min postinjection:309.32× 103 vs 314.13 × 103 counts/MBq;SPECT image,2 min postinjection (corrected):7.96±0.87 vs 8.24± 1.53,t =0.277,P＞0.05),but the myocardial retention time was much longer than that of 99Tcm-TEBO (planar image,20 min postinjection:218.67× 103 vs 143.19× 103 counts/MBq;SPECT image,15 min postinjection (corrected):6.76±0.45 vs 5.06±0.33,t =-12.412,P =0.001).The uptake of liver and heart/liver ratio between 99Tcm-TEBO and 99Tcm-3SP were similar (t values:-1.332-1.101,all P＞0.05 within 15 min).SPECT MPI images demonstrated uniform tracer distribution with clearly visualizable myocardial boundary in normal myocardium and intense perfusion defect in infarct myocardium.High quality SPECT images could be obtained in any of the 5 min imaging windows over the first 15 min after injection of 99Tcm-3SP in normal swine and AMI-swine.Conclusion 99Tcm-3SP is a promising 99 Tcm-labeled radiotracer for fast-MPI considering its high heart uptake,long myocardial retention time (20 min postinjection) and superior SPECT image quality.
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The reversible covalent interaction between boronic acids and cis-diol-containing compounds provides unique affinity for recognition and separation of cis-diol-containing biomolecules such as glycoproteins and sugars. Herein, by using β-blockers and β-agonists as representative hydroxyethylamines, the interaction between phenylboronic acid and hydroxyethylamines was investigated through nuclear magnetic resonance ( NMR) and high performance liquid chromatography ( HPLC ) . The results showed that strong interaction between hydroxyethylamines and phenylboronic acid occurred at high pH value, while the interaction became much weaker and even disappeared at low pH value. This interaction was similar to boronate affinity interaction between boronic acids and cis-diol-containing compounds. However, unlike boronate affinity, the presence of an aprotic solvent disrupted the interaction. The above findings not only provided new insights for in-depth understanding boronate affinity interaction, but also paved the basis for the application of the interaction between boronic acid and hydroxyethylamines.
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Objective To explore the sensitivity and the molecular mechanism of cisplatinresistance ovarian cancer cell line C13 to proteasome inhibitors and the combination with cisplatin. Methods After different treatments, methyl thiazolyl tetrazolium (MTT) assay was applied to examine the cell viability, annexin-V/propidium iodide(PI) apoptosis detection kit was used to determine the apoptosis rate of different groups, western blot assay was introduced to evaluate the expression levels of Fas-associated death domain-like interleukin-1 beta converting enzyme inhibitory protein (cFLIPs), and the activity of caspase-8 was examined. Results MTT assay shown that the cell viability ratios of combination group at serial time points from 12, 24, 36, 48, 60, 72 hours were ( 56.0 ± 8.4 ) %, (44.7 ± 7.3 ) %, ( 33.7 ±11.2) %, (27.6 ± 8.0) %, (27. 6 ± 7.6) % and (28.1 ± 2.4) %, which were much lower than those of cisplatin group (P <0.05). After treated for 24 hours, apoptosis rates of cisplatin group, bortezomib group and combination group were ( 16.7 ± 1.7) %, (23.4 ± 2.1 ) % and (26.9 ± 1.6) %, respectively. The rate of combination group was much higher than that of non-treated group and that of cisplatin group or bortezomib group ( P < 0.05 ). Western blot assay showed the changes of expression levels of cFLIPs, which were downregulated seriously after cisplatin, bortezomib or combination treatment [ (43.2 ± 2.3 )% vs( 75.7 ± 3.0)%vs (67.9 ± 2.1 ) %, P < 0.05 ]. The caspase-8 activity of combination group was (5.6 ± 1.6) folds than that of non-treated group, which was higher than those of other two groups [ ( 2.3 ± 1.0) and (4.2 ± 0.9 ) folds,P < 0.05 ]. Conclusions The tumor cell lethal effect of cisplatin could be increase significantly by the combination application of proteasome inhibitors, bortezomib. And the cFLIPs/caspase-8 signaling pathway may be play an important role in the molecular mechanism of the combination treatment.
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Objective To investigate whether the proteasomes inhibitor MG262 exerts its anticancer function by inducing apoptosis in human ovarian cancer cells,and whether the extracellular signal regulated kinase (ERK) signaling pathway is involved in the regulation of apoptosis induction.Method Human ovarian cancer cell line SKOV3 was incubated with different concentrations of MG262 for 24 and 48 hours.Cell viability was evaluated with 3-(4,5-dimethyhhiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at different time points of culturing.Flow cytometry was used to detect cell apoptosis rate.The expression of vascular endothelial growth factor (VEGF) was evaluated with western blot and enzyme-linked immtmosorbent assay (ELISA).Western blot was used to detect the expression of phosphorylated ERK(pERK) .Results The viability of SKOV3 cells was decreased by MG262 in a concentration-dependent fashion(P＜0.05).After 24 h incubation with MG262 at 1,10,20,40,60 and 80 nmol/L,the viability rates of SKOV3 were (94.6±3.1)%,(92.7±3.7)%,(89.5±7.7)%,(84.2±5.1)%,(82.0±7.4)%and(76.8±11.0) % respectively,and after 48 h incubation,those figures were further decreased to (91.3±10.1)%,(86.8±4.5)%,(74.6±4.2)%,(56.8±2.1)%,(49.3±4.5)% and (37.4±5.4) %,respectively(P＜0.05).Apoptosis rate of SKOV3 cells induced by MG262,PD98059 or their combination was (30.7±4.3)%,(26.8±8.6)% and (50.3±10.6)%,respectively,which were significantly different compared with controls (P＜0.05).In contrast to SKOV3 cells,apoptosis rate of 293T ceils induced by MG262,PD98059 or their combination was (14.5±5.3) %,(16.2±7.5) % and (10.8±7.3)%,respectively,which were not significantly different compared with controls (P＞0.05).pERK expression decreased gradually in a time-dependent manner. And wild-type p53 expression was not significantly different.There was no significant difference between experimental and control 293T cells(P＜0.05).In addition,MG262 down-regulated VEGF secretion and expression in SKOV3 ceils (P＜0.05).Conclusions Proteasome inhibitors can induce apoptosis and inhibit cell proliferation and angiogenesis through ERK signal pathway in SKOV3 cells.
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Objective To explore the semitivity of ovarian cancer cell line SKOV3 to paclitaxel,oroteasome inhibitors,bortezomib,and their combination.Methods The methyl thiazolyl tetrazolitim (MTT)assay was applied to examine the cell viability after treatment.The annexin V-propidium iodide apoptosis detection kit was used to determine the apoptosis rate of different groups.Western blot assay was used to evaluate the expression levels of phosphorylated protein kinase B(AKT)and glycogen synthase kinase-3 beta(GSK-3β).Results In MTT assay,the cell viability ratios of the combination group at serial time points from 12,24,36,48 and 72 hours Were(65.2±5.8)%,(58.3±14.4)%,(35.3±5.0)%,(19.2±1.5)%,and(11.4 ±2.5)%,which were significantly lower than those of the paclitaxel group (P<0.05).After arug treatments,apoptosis rates of paclitaxel group,bortezomib group and the combination group were (14.7±0.5)%,(15.1±0.8)%and(20.5±0.7)%respectively.The rate of the combination group was significantly higher than that of non-treated group and paclitaxel group(P<0.05).Western blot assay showed the changes in expression levels of phosphorylated AKT and GSK-3β,which were decreased significantly after paclitaxd and bortezomib combination treatment [(3.2±0.8)%,(19.3±0.4)%;P<0.05].Conclusions The lethal effect of paclitaxel on tumor cells could be increased significantly by its combination with proteasome inhibitors,bertezomib.The AKT/GSK-3β signaling pathway plays an important role in the molecular mechanism of the combination treatment.
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Objective To investigate the reliability of using inhibitors including Phenylboronic acid (PBA)and Fqucloxacillin(FCC)in detecting derepressed hyperproduction and plasmid-mediated AmpC B-lactamases.Methods PBA and FCC were chosen as inhibitors and double-disk potentiation method and double-disk synergy method were used to detect positive and negative control strains of AmpC β-lactamases and 107 clinical isolates for AmpC β-lactamases production.The positive control strains included E.cloacae (029M),plasmid-mediated ACT-1 type of E.coli DH5a2919,MOX-1 type of k pheumoniae,LAT-2 type of E.coil.The negative control strains included E.cloacae 029(wild-type),E.coli SHV-1,E.coli SHV-2, E.coil SHV-5,E.coli TEM-1,E.coli TEM-3,k peumoniae SHV-18 and E.coli ATCC25922.We compared the results above with the three dimensional test(3-DT)to observe the accuracy in detecting AmpC-BLA.Results 3-DT together with PBA and FCC based inhibition tests showed the 4 positive control strains and the 9 negative control strains were determined as expected.AmpC-BILA was detected in 107 clinical isolates ofEnterobacteriaceaes.The positive rate of3-DTmethod is24.3%.The positive rates ofPBA.FCC double-disk potentiation method and double-disk synergy method are 30.8%(33/107),26.2%(28/107) and 23.4%(25/107),respectively.The conjugate results in two strains of P mirabilis and one strain of K.peumoniae were positive.They were all plasmid-mediated AmpC-Bi.A.There Was a higher false positive when using PBA and FCC-based double-disk potentiation method to detect the induction type of AmpC-BLA, but the accuracy of double-disk synergy method was high.Compared with the 3-DT,the coincidence rate using PBA and FCC-based double-disk synergy method is 99.1%.Conclusions Using PBA and FCC as inhibitors in the double-disk synergy test is a accurate and reliable method to detect AmpC-BLA regardless of derepressed hyperproduction type or plasmid-mediated type.