Long-term HEV carriers without antibody seroconversion among eligible immunocompetent blood donors.

Hepatitis E virus (HEV) is emerging as a potential threat to the safety of blood transfusions. In many countries and regions endemic for HEV, such as China, blood donors are not routinely tested for HEV infection. In this study, 11747 eligible blood donors were screened for anti-HEV immunoglobulin M (IgM)/immunoglobulin G (IgG) and HEV RNA and antigen in China. Twenty-four donors who were positive for both HEV antigen and RNA were followed for ≥ 70 days, and none of these donors reported clinical hepatitis or illness. At least 1 follow-up sample was provided by 17 donors, including 10 with viremia and/or antigenemia for ≥ 70 days and 3 with antigen and RNA positivity for >90 days. Fourteen of the 17 donors did not present with an obvious serologic response during the follow-up period. These results differed from previous reports, in which viremia lasted for 68 days and elicited an antibody response. These donors showed atypical HEV infection progression that differed from that of hepatitis E patients. The presence of these donors presents a challenge for transfusion transmission screening.

A different representation of natural T cells and natural killer cells between tumor-infiltrating and periphery lymphocytes in human hepatocellular carcinoma.

Natural T cells [cluster of differentiation (CD) 3+CD56+] and natural killer (NK) cells (CD3-CD56+) are particularly abundant in the human liver and serve an important role in immune responses in the liver. The aim of the present study was to extensively determine the phenotypic and functional characteristics of natural T and NK cells in human hepatocellular carcinoma (HCC). Tumorous and non-tumorous tissue infiltrating lymphocytes (TILs and NILs, respectively) and peripheral blood mononuclear cells (PBMCs) from patients with hepatocellular carcinoma (HCC) were obtained to determine the frequency and phenotype of natural T/NK cells by a multicolor fluorescence activated cell sorting analysis. The abundance of natural T cells and NK cells was decreased in TILs vs. NILs (natural T cells, 6.315±1.002 vs. 17.16±1.804; NK cells, 6.324±1.559 vs. 14.52±2.336, respectively). However such results were not observed in PBMCs from HCC patients vs. that of healthy donors. Notably, a substantial fraction of the natural T cells (21.96±5.283) in TILs acquired forkhead box P3 (FOXP3) expression, and the FOXP3+ natural T cells lost the expression of interferon-γ and perforin. Conversely, being similar to the conventional FOXP3+ regulatory T cells, the FOXP3+ natural T cells assumed a specific phenotype that was characteristic of CD25+, CD45RO+ and cytotoxic T-lymphocyte-associated protein 4+. Consistent with the phenotypic conversion, the present functional results indicate that FOXP3 expression in natural T cells contributes to the acquisition of a potent immunosuppressive capability. In conclusion, the present study describes a different representation of natural T cells and NK cells in local tumor tissues and in the periphery blood of patients with HCC, and identified a new type of FOXP3-expressing natural T cell spontaneously arising in the TILs of HCC.

[Characteristics Analysis of the Surface Ozone Concentration of China in 2015].

Surface ozone concentration data from 189 cities in China in 2015 were processed by ArcGIS software in order to obtain the characteristics of the surface ozone concentration, such as time and space, topographical features, temperature, etc. The trend for surface ozone concentration was a decrease followed by an increase in China in 2015. The concentrations during the four seasons followed the order:summer > autumn > spring > winter, and the maximum appeared in July. The ozone pollution of East China, South China, and North China were more serious than other regions in China. The variation of longitude had a small influence on the ozone concentration, while the influence of latitude is significant. According to the analysis contrasting three different topographies in the same latitude, the influence of topography on ozone concentration was negligible. Furthermore, the research found a significant positive correlation between surface ozone concentration and temperature.

[Prevalence of Parvovirus B19 Infection in Chinese Xiamen Area Blood Donors].

OBJECTIVE: To estimate the prevalence of parvovirus B19 infection in Chinese Xiamen area blood donors. METHODS: Blood samples from blood donors were tested for detection of parvovirus B19 DNA and antibody. The direct sequencing and genetype analysis of B19 DNA positive samples were performed. RESULTS: Six out of 10452 samples were B19 DNA positive. The viral loads of the 6 samples were between 3.59×102-1.07×104 IU/ml; the positive rate of B19-IgM was 4.64%(50/1078) and B19-IgG was 16.79%(181/1078). The positive rate of B19-IgG increased with ages, and was not related with the sex. CONCLUSION: The overall prevalence of parvovirus B19 infection in blood donors is lower in Chinese Xiamen area than that in other areas, however, there is still a certain percentage of viremia in donors and the attention should be paid to blood safety in the future work.

(18)F-fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma.

AIM: To compare (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma. METHODS: Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent (18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions, including FDG avidity, pattern (focal/diffuse), and intensity [maximal standard uptake value: (SUVmax)]. The correlation of SUVmax with gastric clinicopathological variables was investigated by χ(2) test, and receiver-operating characteristic (ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS: Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients (94.23%) with gastric lymphoma and 65 patients (89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type I and type II lesions, whereas gastric carcinoma patients mainly had type III lesions. The SUVmax (13.39 ± 9.24 vs 8.35 ± 5.80, P < 0.001) and SUVmax/THKmax (maximal thickness) (7.96 ± 4.02 vs 4.88 ± 3.32, P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone. CONCLUSION: PET/CT features differ between gastric lymphoma and carcinoma, which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.

PKC-δ activation in neutrophils promotes fungal clearance.

The C-type lectin receptor dectin-1 and the integrin Mac-1 have key roles in controlling fungal infection. Here, we demonstrate that dectin-1- and Mac-1-induced activation of protein kinase Cδ in neutrophils, independent of the Card9 adaptor, is required for reactive oxygen species production and for intracellular killing upon Candida albicans uptake. Protein kinase Cδ was also required for zymosan-induced cytokine generation in neutrophils. In macrophages, protein kinase Cδ deficiency prevented fungi-induced reactive oxygen species generation but had no effect on activation of TGF-ß-activated kinase-1, an effector of Card9, or nuclear factor κB activation, nor did it affect phagolysosomal maturation, autophagy, or intracellular C. albicans killing. In vivo, protein kinase Cδ-deficient mice were highly susceptible to C. albicans and Aspergillus fumigatus infection, which was partially rescued with adoptively transferred wild-type neutrophils. Thus, protein kinase Cδ activation downstream of dectin-1 and Mac-1 has an important role in neutrophil, but not macrophage, functions required for host defense against fungal pathogens.

Molecular characterization of multidrug-resistant Klebsiella pneumoniae isolates.

Klebsiella pneumoniae is an important cause of healthcare-associated infections worldwide. Selective pressure, the extensive use of antibiotics, and the conjugational transmission of antibiotic resistance genes across bacterial species and genera facilitate the emergence of multidrug-resistant (MDR) K. pneumoniae. Here, we examined the occurrence, phenotypes and genetic features of MDR K. pneumoniae isolated from patients in intensive care units (ICUs) at the First Affiliated Hospital of Xiamen University in Xiamen, China, from January to December 2011. Thirty-eight MDR K. pneumoniae strains were collected. These MDR K. pneumoniae isolates possessed at least seven antibiotic resistance determinants, which contribute to the high-level resistance of these bacteria to aminoglycosides, macrolides, quinolones and ß-lactams. Among these isolates, 24 strains were extended-spectrum ß-lactamase (ESBL) producers, 2 strains were AmpC producers, and 12 strains were both ESBL and AmpC producers. The 38 MDR isolates also contained class I (28/38) and class II integrons (10/38). All 28 class I-positive isolates contained aacC1, aacC4, orfX, orfX' and aadA1 genes. ß-lactam resistance was conferred through bla SHV (22/38), bla TEM (10/38), and bla CTX-M (7/38). The highly conserved bla KPC-2 (37/38) and bla OXA-23(1/38) alleles were responsible for carbapenem resistance, and a gyrAsite mutation (27/38) and the plasmid-mediated qnrB gene (13/38) were responsible for quinolone resistance. Repetitive-sequence-based PCR (REP-PCR) fingerprinting of these MDR strains revealed the presence of five groups and sixteen patterns. The MDR strains from unrelated groups showed different drug resistance patterns; however, some homologous strains also showed different drug resistance profiles. Therefore, REP-PCR-based analyses can provide information to evaluate the epidemic status of nosocomial infection caused by MDR K. pneumoniae; however, this test lacks the power to discriminate some isolates. Thus, we propose that both genotyping and REP-PCR typing should be used to distinguish genetic groups beyond the species level.

Molecular characterization of multidrug-resistant Klebsiella pneumoniae isolates

Klebsiella pneumoniae is an important cause of healthcare-associated infections worldwide. Selective pressure, the extensive use of antibiotics, and the conjugational transmission of antibiotic resistance genes across bacterial species and genera facilitate the emergence of multidrug-resistant (MDR) K. pneumoniae. Here, we examined the occurrence, phenotypes and genetic features of MDR K. pneumoniae isolated from patients in intensive care units (ICUs) at the First Affiliated Hospital of Xiamen University in Xiamen, China, from January to December 2011. Thirty-eight MDR K. pneumoniae strains were collected. These MDR K. pneumoniae isolates possessed at least seven antibiotic resistance determinants, which contribute to the high-level resistance of these bacteria to aminoglycosides, macrolides, quinolones and β-lactams. Among these isolates, 24 strains were extended-spectrum β-lactamase (ESBL) producers, 2 strains were AmpC producers, and 12 strains were both ESBL and AmpC producers. The 38 MDR isolates also contained class I (28/38) and class II integrons (10/38). All 28 class I-positive isolates contained aacC1, aacC4, orfX, orfX’ and aadA1 genes. β-lactam resistance was conferred through bla_SHV (22/38), bla_TEM (10/38), and bla_CTX-M (7/38). The highly conserved bla_KPC-2 (37/38) and bla_OXA-23(1/38) alleles were responsible for carbapenem resistance, and a gyrAsite mutation (27/38) and the plasmid-mediated qnrB gene (13/38) were responsible for quinolone resistance. Repetitive-sequence-based PCR (REP-PCR) fingerprinting of these MDR strains revealed the presence of five groups and sixteen patterns. ...

Molecular characterization of multidrug-resistant Klebsiella pneumoniae isolates

Klebsiella pneumoniae is an important cause of healthcare-associated infections worldwide. Selective pressure, the extensive use of antibiotics, and the conjugational transmission of antibiotic resistance genes across bacterial species and genera facilitate the emergence of multidrug-resistant (MDR) K. pneumoniae. Here, we examined the occurrence, phenotypes and genetic features of MDR K. pneumoniae isolated from patients in intensive care units (ICUs) at the First Affiliated Hospital of Xiamen University in Xiamen, China, from January to December 2011. Thirty-eight MDR K. pneumoniae strains were collected. These MDR K. pneumoniae isolates possessed at least seven antibiotic resistance determinants, which contribute to the high-level resistance of these bacteria to aminoglycosides, macrolides, quinolones and β-lactams. Among these isolates, 24 strains were extended-spectrum β-lactamase (ESBL) producers, 2 strains were AmpC producers, and 12 strains were both ESBL and AmpC producers. The 38 MDR isolates also contained class I (28/38) and class II integrons (10/38). All 28 class I-positive isolates contained aacC1, aacC4, orfX, orfX’ and aadA1 genes. β-lactam resistance was conferred through blaSHV (22/38), blaTEM (10/38), and blaCTX-M (7/38). The highly conserved blaKPC-2 (37/38) and blaOXA-23(1/38) alleles were responsible for carbapenem resistance, and a gyrAsite mutation (27/38) and the plasmid-mediated qnrB gene (13/38) were responsible for quinolone resistance. Repetitive-sequence-based PCR (REP-PCR) fingerprinting of these MDR strains revealed the presence of five groups and sixteen patterns. ...

ClpP affects biofilm formation of Streptococcus mutans differently in the presence of cariogenic carbohydrates through regulating gtfBC and ftf.

The abilities to form biofilms on teeth surface and to metabolize a wide range of carbohydrates are key virulence attributes of Streptococcus mutans. ClpP has been proved to play an important role in biofilm development in streptococci. Here we demonstrated that ClpP was involved in biofilm formation of S. mutans. ClpP inactivation resulted in enhanced biofilm formation or initial cell adherence in broth supplemented with sucrose, while reduced in broth supplemented with glucose or fructose. Our results also indicated that the enhanced capacities of biofilm formation and initial cell adherence were achieved through regulating the expression of a number of extracellular sucrose-metabolizing enzymes, such as glucosyltransferases (GTFB and GTFC) at early-exponential growth phase and fructosyltransferase at late-exponential growth phase in the presence of sucrose.

Comparison of the diagnostic performance of 18F-fluorothymidine versus 18F-fluorodeoxyglucose positron emission tomography on pulmonary lesions: A meta analysis.

A pulmonary lesion is an extremely common and clinically challenging disorder worldwide, and an accurate diagnosis of lung cancer is crucial for early treatment and management. The aim of the present study was to perform a comprehensive meta analysis to compare the diagnostic performance of 18F-fluorothymidine (18F-FLT) positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) PET in evaluating patients with pulmonary lesions. Relevant studies were identified using the PubMed, EMBASE and Cochrane library databases. The pooled estimated sensitivity, specificity, positive-likelihood ratio, negative-likelihood ratio, and diagnostic odds ratio (DOR) for 18F-FLT PET versus 18F-FDG PET were calculated as the main outcome measures. Summary receiver operating characteristic curves were also constructed by Meta-Disk 1.4 software using a Mose's constant of linear model. The meta analysis showed that 18F-FLT PET had a higher specificity (0.70; 95% CI, 0.61-0.77), but lower sensitivity (0.81; 95% CI, 0.74-0.87) compared to 18F-FDG PET (0.50; 95% CI, 0.41-0.58 for specificity; 0.92; 95% CI 0.86-0.95 for sensitivity). For DOR, 18F-FLT PET (12.58; 95% CI, 6.81-23.24) was higher compared to 18F-FDG PET (10.72; 95% CI, 5.51-20.87). The area under the curve was 0.8592 and 0.9240 for 18F-FLT PET and 18F-FDG PET, respectively (Z=0.976, P>0.05). In conclusion, 18F-FLT PET and 18F-FDG PET had good diagnostic performance for the overall assessment of pulmonary lesions, and 18F-FLT PET had a higher specificity compared to 18F-FDG PET, but was less sensitive than 18F-FDG PET. Therefore, 18F-FLT and 18F-FDG together could add diagnostic confidence for pulmonary lesions.

Contribution of ClpP to stress tolerance and virulence properties of Streptococcus mutans.

Abilities to tolerate environmental stresses and to form biofilms on teeth surface are key virulence attributes of Streptococcus mutans, the primary causative agent of human dental caries. ClpP, the chief intracellular protease of S. mutans, along with ATPases degrades altered proteins that might be toxic for bacteria, and thus plays important roles in stress response. To further understand the roles of ClpP in stress response of S. mutans, a ClpP deficient strain was constructed and used for general stress tolerance, autolysis, mutacins production, and virulence assays. Here, we demonstrated that inactivation of ClpP in S. mutans resulted in a sensitive phenotype to several environmental stresses, including acid, cold, thermal, and oxidative stresses. The ClpP deficient strain displayed slow growth rates, poor growth yields, formation of long chains, increased clumping in broth, and reduced capacity to form biofilms in presence of glucose. Mutacins production and autolysis of S. mutans were also impaired by mutation of clpP. Animals study showed that clpP mutation increased virulence of S. mutans but not significant. However, enhanced abilities to survive lethal acid and to form biofilm in sucrose were observed in ClpP deficient strain. Our findings revealed a broad impact of ClpP on several virulence properties of S. mutans and highlighted the relevance of ClpP proteolysis with progression of diseases caused by S. mutans.

[Value of dual-time-point (18)F-fluorodeoxyglucose integrated positron emission and computed tomography in differentiation of malignant from benign gastrointestinal diseases].

OBJECTIVE: To explore the value of dual-time-point (18)F-fluorodeoxyglucose integrated positron emission and computed tomography ((18)F-FDG PET-CT) in differentiation of malignant from benign gastrointestinal diseases. METHODS: Sixty five patients with suspected gastrointestinal lesions underwent dual-time-point (18)F-FDG PET-CT imaging. Standardized uptake value (SUV) was calculated for semi-quantitative assessment. The SUV of the two acquisitions were signed SUV(early) and SUV(delayed), respectively. Then the change of SUVmax (ΔSUVmax) was calculated. The ROC curves of the SUV(early), SUV(delayed) and ΔSUV were drawn to find the best cut-off point value for differential diagnosis, and then the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated, respectively. RESULTS: Of the malignant lesions, the SUVmax in delayed imaging were significantly higher than those in early imaging, while there were no significant differences of SUVmax between the two images of the benign lesions. The ΔSUVmax of the malignant lesions were significantly higher than that of the benign ones. Taking the SUVmax higher than 9.2 in early imaging as positive diagnostic criteria, the sensitivity was 72.7%, the specificity was 85.7%, the positive predictive value was 91.4%, the negative predictive value was 60.0%, and the accuracy was 76.9%. Taking the SUVmax higher than 10.9 in delayed imaging as positive diagnostic criteria, the sensitivity was 75.0%, the specificity was 90.5%, the positive predictive value was 94.3%, the negative predictive value was 63.3%, and the accuracy was 80.0%. Taking the ΔSUVmax higher than 5.1% as positive diagnostic criteria, the sensitivity was 95.5%, the specificity was 85.7%, the positive predictive value was 93.3%, the negative predictive value was 90.0%, and the accuracy was 92.3%. The accuracy of dual-time-point (18)F-FDG PET-CT imaging was significantly higher than that of single-time point (18)F-FDG PET-CT imaging. CONCLUSION: Dual-time-point (18)F-FDG PET-CT imaging is a useful method for differentiating malignant from benign gastrointestinal diseases, and it is superior to the single-time point (18)F-FDG PET-CT imaging.

[Clinical significance of (18)F-FDG PET/CT evaluation of response to treatment in T-cell lymphoma].

OBJECTIVE: To investigate the usefulness of (18)F-FDG PET/CT imaging in restaging, evaluating the treatment outcome, monitoring relapse and predicting prognosis of T-cell lymphoma. METHODS: Retrospective analysis of PET/CT image results of thirty-four patients with T-cell lymphoma, and to evaluate its clinical significance in restaging, treatment efficiency, relapse monitor and prognosis prediction. RESULTS: Clinical restaging among the 20 stage I and II patients, 6 were ascended, 9 descended and 5 unchanged. Restaging among the other 14 stage III and IV patients, 3 were ascended, 4 descended and 7 unchanged. There were 12 patients in complete remission (CR), 11 in partial remission (PR), 2 in stable disease (SD) and 9 in progressive disease (PD) among all the 34 patients. There is obvious statistical difference of the standardized uptake value (SUV) between the efficacy group and the inefficacy group after treatment of 6 courses at least in 25 patients among all the 34 patients (P = 0.009). There is obvious statistical difference of the SUV value before and after treatment in 8 patients among all the 34 patients (P = 0.000). There is obvious statistical difference in the survival time between the efficacy group and the inefficacy group after treatment of 6 courses at least in 25 patients among all the 34 patients (P = 0.015). CONCLUSIONS: (18)F-FDG PET/CT imaging plays an very important role in guiding clinical restaging, evaluating the treatment outcome, monitoring relapse and predicting prognosis of T-cell lymphoma. It is helpful to establish personalized treatment planning.

[Changes of dendritic cells and its subsets in peripheral blood of patients with Mycobacterium tuberculosis].

AIM: To analyze the changes of dendritic cells and its subsets in peripheral blood of patients with mycobacterium tuberculosis, and to explore its immune mechanism. METHODS: 32 patients with mycobacterium tuberculosis and 11 healthy controls were selected, who were diagnosed in our hospital from Nov. 2008 to Aug. 2009. The patients included 19 initial-treatment cases and 13 retreatment cases, and 19 lung tuberculosis patients with different sputum tests. Dendritic cells and its subsets in peripheral blood were detected by using flow cytometry. RESULTS: DC1 subset and Total DCs in experimental group were (0.28+/-0.13)%, (0.42+/-0.19)% respectively, which were significant lower than they were in control group (0.47+/-0.23)%, (0.65+/-0.22)% respectively (P<0.01); DC1 subset and Total DCs in sputum positive group were (0.16+/-0.04)%, (0.24+/-0.06)% respectively, which were significant lower than they were in sputum negative group(0.28+/-0.14)%, (0.43+/-0.12)% (P<0.05); There was no significance in Total DCs and its subsets between initial-treatment group and retreatment group (P>0.05). CONCLUSION: As its reflection of immune response to mycobacterium tuberculosis, DCs may be regarded as the indicator for screening reservoirs of MTB and evaluating anti-tuberculosis therapy.

[Growing characteristic of breast adenocarcinoma suicide gene cell line T47D-tk and construction of subcutaneous xenografts].

OBJECTIVE: To further identify the breast adenocarcinoma cell line T47D-tk stably expressing the suicide gene HSV1-tk, observe its growing characteristics, and establish an animal model of implanted breast adenocarcinoma. METHODS: Retroviral vector of HSV1-tk gene and breast carcinoma cell line T47D-tk stably expressing the HSV1-tk gene were established. Breast carcinoma cells of the lines T47D and T47D-tk were cultured, and observed by inverted microscope. Growth curve was drawn. Genomic DNA of T47D-tk cells was extracted, and amplified by PCR with HSV1-tk and HSV1-tk P2 as primers. Agarose gel electrophoresis was used to identify the HSV1tk gene. Suspensions of T47D and T47D-tk cells were inoculated subcutaneously at bilateral roots of foreleg of female BALB/c nude mice respectively. The growth of tumor was observed every day. RESULTS: PCR showed 1131 bp fragment in the T47D-tk genome, but not in the T47D genome. The numbers of growing T47D cells on days 3, and 7 were (10.00 +/- 1.30) x 10(3) and (19.25 +/- 0.66) x 10(3) respectively, not significantly different from those of the T47D-tk cells [(10.25 +/- 0.90) x 10(3) and (19.00 +/- 1.80) x 10(3) respectively, both P > 0.05]. The time needed for tumor formation after the inoculation of T47D cells was (9.67 +/- 0.33) d, not significantly different from that of the T47D-tk cells [(9.83 +/- 0.48) d, P > 0.05]. The tumor size 19 days after inoculation of the T47D cells was (72.17 +/- 25.88) mm(3), not significantly different from that of the T47D-tk cells [(70.66 +/- 22.16) mm(3), P > 0.05]. CONCLUSION: The T47D-tk cells have integrated the HSV1-tk gene without changing its growing characteristics. An animal model of implanted breast cancer has been successfully established. The T47D and T47D-tk subcutaneous xenografts offer the foundation for further study of gene imaging and gene therapy.

[Molecular imaging for PET-CT reporter gene in breast adenocarcinoma (HSV1-tk) of subcutaneous xenografts in living nude mice].

OBJECTIVE: To study the in vitro accumulation of (18)F-FHBG, its in vivo distribution and (18)F-FHBG PET-CT imaging for reporter gene (HSV1-tk) in nude mice with a xenograft of breast adenocarcinoma. METHODS: The in vitro uptake of (18)F-FHBG in tumor cells of T47D and T47D-tk and the distribution of (18)F-FHBG in normal Kunming mice and nude mice with breast adenocarcinoma xenograft were detected by well-type gamma counter. Reporter gene PET-CT imaging with (18)F-FHBG was performed in nude mice with a xenograft of breast adenocarcinoma. And the expression location of HSV1-tk gene could be monitored by observing the in vitro and in vivo accumulation of (18)F-FHBG. RESULTS: The in vitro uptake of (18)F-FHBG in T47D-tk cells (143.67 dpm/10(4) +/- 5.82 dpm/10(4) cells) was significantly higher than that in T47D cells (2.23 dpm/10(4) +/- 0.23 dpm/10(4) cells) at 60 and 120 min post-injection (P < 0.001) and reaches a plateau at 60 min. In normal Kunming mice, (18)F-FHBG was mainly distributed in liver, intestine, kidney and bladder while there was no obvious radioactive accumulation in brain. (18)F-FHBG accumulated at a significantly higher level in T47D-tk tumors than in T47D tumors and its accumulation yielded the best image effect at 2 h by PET-CT imaging in nude mice. CONCLUSION: The in vitro uptake of (18)F-FHBG in T47D-tk cells is significantly higher than that in T47D cells. (18)F-FHBG is mainly excreted by digestive tract and urinary tract in mice. It agrees with the expression pattern of HSV1-tk gene. (18)F-FHBG can determine the localization of HSV1-tk gene expression in an efficient way. This study will offer a monitoring method and scientific base for (18)F-FHBG reporter gene imaging and HSV1-tk gene therapy in tumors.