Secondhand smoke exposure can increase the risk of first ischemic stroke: A 10.7-year prospective cohort study in China.

INTRODUCTION: Passive smoking is considered a major public health issue in China. Prospective evidence regarding the link between secondhand smoke (SHS) and ischemic stroke in China is scarce. METHODS: The China Kadoorie Biobank (CKB) study in Liuzhou City recruited 50,174 participants during 2004-2008. Of these 30,456 never-smokers were included in our study. The median follow-up period was 10.7 years. The incidence of ischemic stroke was obtained through the China Disease Surveillance Points (DSP) system and the Health Insurance (HI) database. Cox proportional risk models were used to evaluate the association between SHS exposure and ischemic stroke. RESULTS: During 320,678 person-years of follow-up, there were 2059 patients with ischemic stroke observed and the incidence of ischemic stroke was 6.42 per thousand person-years. Participants exposed to SHS daily faced a 21 % higher risk of ischemic stroke (HR = 1.21, 95 %CI: 1.09-1.34) compared to those exposed to SHS less than once a week. Subgroup analyses revealed that daily SHS exposure was linked to heightened risk of ischemic stroke among women, non-employed, and non-weekly tea drinkers. CONCLUSIONS: Daily SHS exposure was associated with higher risks of ischemic stroke. Proactive tobacco control strategies are necessary to decrease the risk of ischemic stroke in never smokers.

SPECT Imaging of Treatment-Related Tumor Necrosis Using Technetium-99m-Labeled Rhein.

PURPOSE: Noninvasive imaging of treatment-induced necrosis is important to distinguish early responders from patients resistant to the treatment plan, enabling the tailored-made therapeutic intervention. The purpose of this study was to explore the feasibility of [99mTc]EDDA-HYNIC-2C-rhein for early assessment of tumor response to treatment. PROCEDURES: In vitro necrosis avidity of [99mTc]EDDA-HYNIC-2C-rhein was evaluated in human lung cancer A549 cells treated with hyperthermia. Single photon emission-computed tomography/X-ray-computed tomography (SPECT/CT) imaging was performed in rats bearing subcutaneous W256 tumor treated with combretastatin A-4 disodium phosphate (CA4P) and rats bearing orthotopic liver W256 tumor treated with a single microwave ablation. All rats were euthanized immediately after the imaging session for biodistribution and histology studies. The mechanism of necrosis avidity for the tracer was further explored by in vivo blocking experiment and in vitro histochemistry and fluorescence staining. RESULTS: The uptake of [99mTc]EDDA-HYNIC-2C-rhein in necrotic cells was significantly higher than that in viable cells (p < 0.05). SPECT/CT imaging showed that an obvious "hot spot" was observed in the CA4P-treated tumor while not in the control tumor at 5 h after tracer injection. Ex vivo γ-counting revealed that the uptake of [99mTc]EDDA-HYNIC-2C-rhein in tumor was increased 3.5-fold in rats treated with CA4P compared with rats treated with vehicle. Autoradiography and corresponding H&E staining suggested that the higher overall radiotracer uptake in the treated tumors was attributed to the increased necrosis. Blocking with unlabeled HYNIC-2C-rhein demonstrated the specific binding of the radiotracer to necrotic tissues. The perfect match of autoradiograph and histochemistry staining and PI fluorescence staining revealed that necrosis avidity of the tracer may be attributable to intercalation with exposed DNA in necrotic tissues. CONCLUSION: [99mTc]EDDA-HYNIC-2C-rhein can image necrosis induced by anticancer therapy and holds potential for early assessment of treatment response.

First Evaluation of Radioiodinated Flavonoids as Necrosis-Avid Agents and Application in Early Assessment of Tumor Necrosis.

A rapid and accurate identification of necrotic tissues is of great importance to define disease severity, predict prognosis, and monitor responses to therapies. To seek necrosis-avid agents with clinically translational potential, we first evaluated the necrosis avidity of flavonoids in rodent models of muscular, myocardial, and tumoral necrosis. In this study, the necrosis avidity of eight radioiodinated 5,7-dihydroxyflavones was tested by ex vivo gamma counting, histochemical staining, and autoradiography in mouse models of ethanol-induced muscular necrosis. The necrosis avidity of a lead tracer, 131I-5, was further assessed in rat models of myocardial infarction and reperfusion. Therapy response was evaluated by 131I-5 single photon emission computed tomography/computed tomography imaging 24 h after combretastatin A-4 disodium phosphate (CA4P) therapy on rats bearing W256 breast carcinomas. The necrosis avidity mechanism for the tracers was studied by in vitro DNA binding experiments of 12 5,7-dihydroxyflavones and in vivo blocking experiments of 131I-5. In the results, all 131I-5,7-dihydroxyflavones showed intense uptake to necrotic muscles, and 131I-5 emerged as the most potential tracer among them. 131I-5 obtained a necrotic-viable myocardium ratio of 5.0 ± 0.9 in post-mortem biodistribution on reperfused myocardial infarction models and achieved necrosis imaging on CA4P-treated W256 tumors 4 h after tracer injection. DNA binding studies suggested that necrosis avidity was related to DNA binding to a certain extent. The uptake of 131I-5 in necrotic muscle was markedly blocked by excessive ethidium bromide and cold 5 with a 51.95% and 64.29% decline at 1 h after coinjection, respectively. In conclusion, flavonoids are necrosis-avid agents. Furthermore, 131I-5 can serve as a promising necrosis-avid diagnostic tracer for the rapid imaging of necrotic tissues, supporting the further molecular design of radiotracer based on 5.

[Expression of DNA-dependent protein kinase catalytic subunit in adult acute leukemia and its significance].

This study was aimed to explore the expression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in adult acute leukemia and its correlation with clinical characteristics, karyotype and prognosis. Indirect immunofluorescent cytometry was used to detect the expression of DNA-PKcs in bone marrow mononuclear cells of 105 patients with acute leukemia before chemotherapy and 41 of them after 2 cycles of chemotherapy. Cytogenetic data were obtained from 26 of them by R band karyotypic analysis. The results showed that the expression of DNA-PKcs was correlated with higher WBC count level in peripheral blood (p < 0.05), but was not obviously associated with median age, gender, percentage of bone marrow blasts, clinical classification, median hemoglobin level and median platelet count (p > 0.05). The middle and strong positive expression of DNA-Pkcs in non-remission group was significantly higher than that in remission group (p < 0.05). The positive rate of DNA-PKcs in abnormal chromosome group was significantly higher than that in chromosome normal group (p < 0.05). It is concluded that the DNA-PKcs expression level is closely related with the increased WBC count, and the expression of DNA-PKcs is correlated also with karyotype and clinical prognosis in adult acute leukemia.

[Screening and structure analysis of nucleic acid aptamers binding to surface of CD33(+)/CD34(+) cells from patients with acute myeloid leukemia subtype M2].

A little is known about the specific marker on the surface of acute leukemia cells, leading to the lack of the specific diagnosis method for acute leukemia. Therefore, in this study, cell-systematic evolution of ligands by exponential enrichment (cSELEX) was performed to screen the aptamers binding to CD33(+)/CD34(+) cells from the patients with acute myeloblastic leukemia (AML) of M(2) subtype (AML-M2) so as to provide the basis for finding the specific marker on the surface of AML-M(2) CD33(+)/CD34(+) cells. Firstly, AML-M2 CD33(+)/CD34(+) cells were sorted and used as targeted cells, and normal CD33(+)/CD34(+)cells were used as counter-targeted cells; the aptamers binding to CD33(+)/CD34(+) cells from patients with AML-M2 were screened from the single strand deoxyribonucleic acid (ssDNA) library by cSELEX. Subsequently, each aptamer structure was analyzed after cloning and sequencing. The results indicated that after 13 round of screenings, the enrichment of aptamers in the ssDNA library was ranged from 0.7% to 52.9%, and reached steady state at 13th round screening. Sequence analysis for 30 aptamers showed that most of the aptamers born one of the three conserved sequences of CCCCT, CTCTC, and CTCAC. Secondary structure analysis indicated that three different secondary structures existed in these aptamers. It is concluded that the aptamers binding to the AML-M(2) CD33(+)/CD34(+) cells are successfully screened, which lay the basis for further looking for the specific marker on the surface of AML-M2 CD33(+)/CD34(+) cells, and the molecular diagnosis of the AML-M2 leukemia.