Metabolic parameters of pretreatment 2-[18F]fluoro-D-glucose positron emission tomography for prognosis in patients with gallbladder adenocarcinoma: a cohort study.

Background: The incidence of gallbladder adenocarcinoma (GBA) is relatively low, yet it exhibits a high degree of malignancy and a significantly low 5-year survival rate. The aim of this study was to investigate the prognostic value of pretreatment 2-[18F]fluoro-D-glucose positron emission tomography {2-[18F]FDG PET} parameters in predicting outcomes for patients with GBA. Methods: In total, 67 patients with GBA who underwent 2-[18F]FDG PET/computed tomography (CT) before treatment were retrospectively analyzed at Chinese PLA General Hospital from January 2012 to June 2022. All patients were diagnosed by pathology, and their baseline characteristics and clinical data were collected. The metabolic PET parameters of the primary and metastatic lesions were measured, including the maximum and average standardized uptake values (SUVs), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The prognostic significance of metabolic parameters and other clinical variables was assessed using Cox proportional hazards regression models. Differences in progression-free survival (PFS) and overall survival (OS) in relation to metabolic parameters were examined using the Kaplan-Meier method. Results: During a median follow-up period of 14.2 months, 43 patients (64.2%) experienced tumor recurrence or progression, and 38 patients (56.7%) died of cancer. In the univariate Cox regression analysis, liver parenchymal invasion (P=0.001), lymph node metastasis (P=0.007), distant metastases (P=0.049), tumor differentiation (P=0.028), surgery (P=0.014), carcinoembryonic antigen (CEA) level (P=0.030), carbohydrate antigen 19-9 (CA19-9) level (P=0.003), TLG (P=0.005), MTV (P<0.001), sum of the TLGs of the primary and metastatic lesions (total TLG, tTLG) (P=0.001), and sum of the MTVs of the primary and metastatic lesions (total MTV, tMTV) (P<0.001) were significant predictors of PFS. In multivariate analysis, MTV was an independent predictor of PFS [hazard ratio (HR) =2.785; 95% confidence interval (CI): 1.204-6.441; P=0.017]. In the univariate Cox regression analysis, liver parenchymal invasion (P=0.001), lymph node metastasis (P=0.027), distant metastases (P=0.036), tumor differentiation (P=0.047), surgery (P=0.002), neutrophil-to-lymphocyte ratio (NLR) (P=0.011), CEA level (P=0.036), CA19-9 level (P<0.001), TLG (P=0.007), MTV (P<0.001), tTLG (P=0.003), and tMTV (P<0.001) were significant predictors of OS. In the multivariate analysis, higher CA19-9 levels >37 U/mL and a greater tMTV (HR =2.961; 95% CI: 1.092-8.024; P=0.033) were predictive of OS. Conclusions: Our study results suggest that pretreatment 2-[18F]FDG PET parameters can not only assist in the diagnosis of patients with GBA but may also serve as predictive factors for the prognosis of these patients and should thus be applied in their treatment.

Multiparameter diagnostic model based on 18F-FDG positron emission tomography and serological examination for differentiating focal autoimmune pancreatitis from pancreatic ductal adenocarcinoma.

Background: 18F-fluorodeoxyglucose positron emission tomography-computerized tomography (18F-FDG PET-CT) has demonstrated high sensitivity in the diagnosis of autoimmune pancreatitis (AIP) and pancreatic ductal adenocarcinoma (PDAC), while also exhibiting the ability to distinguish AIP from PDAC lesions. The objective of this investigation was to assess the efficacy of multiparametric 18F-FDG PET with serological examination for distinguishing focal AIP (f-AIP) from PDAC. Methods: A total of 127 patients (43 with f-AIP and 84 with PDAC) who received 18F-FDG PET-CT before treatment were retrospectively included in the cohort study conducted at two centers, Beijing Friendship Hospital and Chinese PLA General Hospital, from January 2015 to December 2021. The baseline characteristics and clinical data were collected. The metabolism parameters of 18F-FDG PET, including maximum standardized uptake value (SUVmax), tumor-to-normal liver SUV ratio (SUVR), mean SUV (SUVmean), total lesion glycolysis (TLG), and metabolic tumor volume (MTV) were evaluated. The area under the receiver operating characteristic (ROC) curve was used to evaluate the differential diagnostic efficacy. The diagnostic efficacy improvement was assessed through the integrated discriminatory improvement (IDI), net reclassification improvement (NRI), and DeLong test. Results: Serum immunoglobulin G4 (IgG4) >280 mg/dL, carbohydrate antigen 19-9 (CA19-9) <85 U/mL, and metabolic parameters differed significantly between patients with f-AID and PDAC. The ROC curve analysis of MTV showed the highest differentiating diagnostic value [sensitivity =0.814, 95% confidence interval (CI): 0.661-0.911; specificity =0.893, 95% CI: 0.802-0.947; area under the curve (AUC) =0.890, 95% CI: 0.820-0.957]. The combined diagnostics model of serum IgG4 >280 mg/dL, CA19-9 <85 U/mL, and MTV resulted in the highest AUC of 0.991 (95% CI: 0.978-1.000; sensitivity =0.953, 95% CI: 0.829-0.992; specificity =0.964, 95% CI: 0.892-0.991). Conclusions: The multiparameter diagnostic model based on 18F-FDG PET and serological examination has excellent clinical value in the differential diagnosis of f-AID and PDAC.

BMI-1 activates hepatic stellate cells to promote the epithelial-mesenchymal transition of colorectal cancer cells.

BACKGROUND: Activated hepatic stellate cells (aHSCs) are the major source of cancer-associated fibroblasts in the liver. Although the crosstalk between aHSCs and colorectal cancer (CRC) cells supports liver metastasis (LM), the mechanisms are largely unknown. AIM: To explore the role of BMI-1, a polycomb group protein family member, which is highly expressed in LM, and the interaction between aHSCs and CRC cells in promoting CRC liver metastasis (CRLM). METHODS: Immunohistochemistry was carried out to examine BMI-1 expression in LM and matched liver specimens of CRC. The expression levels of BMI-1 in mouse liver during CRLM (0, 7, 14, 21, and 28 d) were detected by Western blotting (WB) and the quantitative polymerase chain reaction (qPCR) assay. We overexpressed BMI-1 in HSCs (LX2) by lentivirus infection and tested the molecular markers of aHSCs by WB, qPCR, and the immunofluorescence assay. CRC cells (HCT116 and DLD1) were cultured in HSC-conditioned medium (LX2 NC CM or LX2 BMI-1 CM). CM-induced CRC cell proliferation, migration, epithelial-mesenchymal transition (EMT) phenotype, and transforming growth factor beta (TGF-ß)/SMAD pathway changes were investigated in vitro. A mouse subcutaneous xenotransplantation tumor model was established by co-implantation of HSCs (LX2 NC or LX2 BMI-1) and CRC cells to investigate the effects of HSCs on tumor growth and the EMT phenotype in vivo. RESULTS: Positive of BMI-1 expression in the liver of CRLM patients was 77.8%. The expression level of BMI-1 continued to increase during CRLM in mouse liver cells. LX2 overexpressed BMI-1 was activated, accompanied by increased expression level of alpha smooth muscle actin, fibronectin, TGF-ß1, matrix metalloproteinases, and interleukin 6. CRC cells cultured in BMI-1 CM exhibited enhanced proliferation and migration ability, EMT phenotype and activation of the TGF-ß/SMAD pathway. In addition, the TGF-ßR inhibitor SB-505124 diminished the effect of BMI-1 CM on SMAD2/3 phosphorylation in CRC cells. Furthermore, BMI-1 overexpressed LX2 HSCs promoted tumor growth and the EMT phenotype in vivo. CONCLUSION: High expression of BMI-1 in liver cells is associated with CRLM progression. BMI-1 activates HSCs to secrete factors to form a prometastatic environment in the liver, and aHSCs promote proliferation, migration, and the EMT in CRC cells partially through the TGF-ß/SMAD pathway.

Corrigendum: The role of 18F-FDG PET in predicting the pathological response and prognosis to unresectable HCC patients treated with lenvatinib and PD-1 inhibitors as a conversion therapy.

[This corrects the article DOI: 10.3389/fimmu.2023.1151967.].

The role of 18F-FDG PET in predicting the pathological response and prognosis to unresectable HCC patients treated with lenvatinib and PD-1 inhibitors as a conversion therapy.

Purpose: To investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET), as an imaging biomarker, for predicting pathological response and prognosis of unresectable hepatocellular carcinoma (HCC) patients treated with Lenvatinib and programmed cell death protein 1 (PD-1) inhibitors as a conversion therapy. Methods: A total of 28 unresectable HCC patients with BCLC stage B or C were treated with Lenvatinib and PD-1 inhibitors before surgery. The 18F-FDG PET/CT scans were acquired before pre- (scan-1) and post-conversion therapy (scan-2). The maximum standardized uptake value (SUVmax), TLR (tumor-to-normal liver standardized uptake value ratio), and the percentages of post-treatment changes in metabolic parameters (ΔSUVmax [%] and ΔTLR [%]) were calculated. Major pathological response (MPR) was identified based on the residual viable tumor in the resected primary tumor specimen (≤10%). Differences in the progression-free survival (PFS) and overall survival (OS) stratified by ΔTLR were examined by the Kaplan-Meier method. Results: 11 (11/28, 39.3%) patients were considered as MPR responders and 17 (17/28, 60.7%) patients as non-MPR responders after conversion therapy. ΔSUVmax (-70.0 [-78.8, -48.8] vs. -21.7 [-38.8, 5.7], respectively; P<0.001) and ΔTLR (-67.6 [-78.1, -56.8] vs. -18.6 [-27.9, 4.0], respectively; P<0.001) were reduced in the responder group than those in the non-responder group. According to the results of the receiver operating characteristic curve analysis, ΔTLR showed an excellent predictive value for the MPR of primary HCC lesions (area under curve=0.989, with the optimal diagnostic threshold of -46.15). When using ΔTLR of -21.36% as a threshold, patients with ΔTLR-based metabolic response had superior PFS (log-rank test, P=0.001) and OS (log-rank test, P=0.016) compared with those without ΔTLR-based metabolic response. Conclusion: 18F-FDG PET is a valuable tool for predicting pathological response and prognosis of unresectable HCC patients treated by Lenvatinib combined with PD-1 as a conversion therapy.

Can 18F-PSMA-7Q PET/CT replace prostate biopsy for the diagnosis of prostate cancer?-A single-center retrospective study.

Background: Of the currently available prostate-specific membrane antigen (PSMA) positron emission tomography (PET) tracers, although 68Ga-PSMA-11 and 18F-DCFPyL have been approved by the US Food and Drug Administration (FDA), both tracers are excreted rapidly through the urinary tract, resulting in strong accumulation in the bladder and blurring the prostate.18F-PSMA-7Q is a novel quinoline-containing PSMA PET tracer developed by our team, which is primarily excreted through the liver. It can reduce the incidence of urine-induced false-positives in the prostate. We aimed to explore the diagnostic efficacy of 18F-PSMA-7Q PET/computed tomography (CT), and when 18F-PSMA-7Q PET/CT can be used instead of prostate biopsy to diagnose prostate cancer. Methods: Patients who underwent 18F-PSMA-7Q PET/CT for prostate cancer staging or prostate biopsy guidance at our institution between July 2020 and December 2021 were retrospectively enrolled. Molecular imaging PSMA (miPSMA) scores were assigned for intra-prostatic lesions according to the Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE) criteria, and the diagnostic efficacy of 18F-PSMA-7Q PET/CT for different miPSMA scores was evaluated using pathological diagnosis as the gold standard. Results: Of the 125 enrolled patients, 101 had prostate cancer, and 24 had prostatic hyperplasia or prostatitis. miPSMA ≥2 was the optimal diagnostic threshold, and area under curve (AUC) was 0.948, the sensitivity and specificity were 91.1% and 83.0%. The prostate cancer detection rates of 18F-PSMA-7Q PET/CT were 14.3% (3/21), 60.0% (6/10), 96.7% (58/60), and 100% (34/34) for patients with miPSMA scores of 0, 1, 2, and 3, respectively. There was no significant difference in the detection rate of prostate cancer between groups with miPSMA scores of 2 and 3, but there were significant differences between any other 2 groups. Conclusions: The prostate cancer detection rate of 18F-PSMA-7Q PET/CT was high for lesions with greater miPSMA scores of 2 and 3. For patients with a high miPSMA score, particularly those with a miPSMA score of 3, prostate biopsy can be omitted and prostate cancer-related treatment can be considered.

Multiparameter diagnostic model based on 18F-FDG PET metabolic parameters and clinical variables can differentiate nonmetastatic gallbladder cancer and cholecystitis.

OBJECTIVE: To evaluate the diagnostic value of a multiparameter model based on 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) metabolic parameters and clinical variables in differentiating nonmetastatic gallbladder cancer (GBC) from cholecystitis. PATIENTS AND METHODS: In total, 122 patients (88 GBC nonmetastatic patients and 34 cholecystitis patients) with gallbladder space-occupying lesions who underwent 18F-FDG PET/CT were included. All patients received surgery and pathology, and baseline characteristics and clinical data were also collected. The metabolic parameters of 18F-FDG PET, including SUVmax (maximum standard uptake value), SUVmean (mean standard uptake value), SUVpeak (peak standard uptake value), MTV (metabolic tumour volume), TLG (total lesion glycolysis) and SUVR (tumour-to-normal liver standard uptake value ratio), were evaluated. The differential diagnostic efficacy of each independent parameter and multiparameter combination model was evaluated using the receiver operating characteristic (ROC) curve. The improvement in diagnostic efficacy using a combination of the above multiple parameters was evaluated by integrated discriminatory improvement (IDI), net reclassification improvement (NRI) and bootstrap test. Decision curve analysis (DCA) was used to evaluate clinical efficacy. RESULTS: The ROC curve showed that SUVR had the highest diagnostic ability among the 18F-FDG PET metabolic parameters (area under the curve [AUC] = 0.698; sensitivity = 0.341; specificity = 0.971; positive predictive value [PPV] = 0.968; negative predictive value [NPV] = 0.363). The combined diagnostic model of cholecystolithiasis, fever, CEA > 5 ng/ml and SUVR showed an AUC of 0.899 (sensitivity = 0.909, specificity = 0.735, PPV = 0.899, NPV = 0.758). The diagnostic efficiency of the model was improved significantly compared with SUVR. The clinical efficacy of the model was confirmed by DCA. CONCLUSIONS: The multiparameter diagnostic model composed of 18F-FDG PET metabolic parameters (SUVR) and clinical variables, including patient signs (fever), medical history (cholecystolithiasis) and laboratory examination (CEA > 5 ng/ml), has good diagnostic efficacy in the differential diagnosis of nonmetastatic GBC and cholecystitis.

A Preclinical Study of an 125I-Labeled PSMA Ligand for Prostate-Cancer Puncture.

PURPOSE: Prostate cancer (PCa) is characterized by high expression of prostate-specific 1membrane antigen (PSMA), a type II transmembrane protein. Prostate-specific membrane antigen positron emission tomography (PSMA PET) has high sensitivity and specificity and can therefore be potentially used to detect PCa. Exploiting the advantages of PSMA PET imaging, in this study, we aim to develop a novel radiopharmaceutical to facilitate biopsy punching of PCa. METHODS: We synthesized a high-affinity radiopharmaceutical of PSMA (125I-PSMA-7). We evaluated the properties of 125I-PSMA-7, including the purity, stability, affinity, partition coefficient, and toxicity. (PSMA+) 22Rv1 and (PSMA-) PC3 cell lines were used to evaluate 125I-PSMA-7 in vitro. BALB/c nude mice bearing 22Rv1 and PC3 xenografts were used for biodistribution and imaging. The uptake of the main organs was evaluated in vivo using single photon emission computed tomography (SPECT). RESULTS: 125I-PSMA-7 had a purity of 99.6% and remained stable for seven days and was therefore always safe to use. 125I-PSMA-7 had a Ki of 4.037 × 10-11 and a partition coefficient of -1.80. The results of in vitro cellular experiments showed a high uptake by 22Rv1 cells (ranging from 2.88 ± 0.14 IA%/106 at 5 min to 61.98 ± 3.43 IA%/106 at 24 h, where the internalization was 46.1% at 1 h and 88.06% at 24 h). However, the uptake of PC3 cells was very low (ranging from 0.34 ± 0.08 IA%/106 at 5 min to 1.60 ± 0.15 IA%/106 at 24 h). The tumors' uptake of 125I-PSMA-7 ranged from 9.02 ± 0.30 ID%/g at 1 h to 4.11 ± 1.04 ID%/g at 7 d and the tumor/muscle ratios and tumor/blood ratios increased over time. In addition, we used γ-counter to measure cpm per milligram of tumor and muscle on days 4 and 7. The background on day 4 is 42 cpm and the tumor is 1739 cpm/mg and the muscle is 45 cpm/mg, and the background on day 7 is 74 cpm and the tumor is 1404cpm/mg and the muscle is 32 cpm/mg. At 1 h post-injection, the high uptake of 125I-PSMA-7 resulted in clear delineation of 22Rv1-derived tumors upon imaging. By comparison, 22Rv1-blocking mice took up less 125I-PSMA-7. CONCLUSIONS: These results show that 125I-PSMA-7 is a promising radiotracer that could be used to puncture the prostate. 125I-PSMA-7 could be applied to targeted biopsy, reducing the need for saturated biopsy.

Pretreatment Metabolic Parameters Measured by 18F-FDG PET to Predict the Pathological Treatment Response of HCC Patients Treated With PD-1 Inhibitors and Lenvatinib as a Conversion Therapy in BCLC Stage C.

Objectives: This study aimed to assess the pretreatment 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) as a predictor of the pathological treatment response (PTR) of hepatocellular carcinoma (HCC) patients treated with PD-1 inhibitors and lenvatinib as a conversion therapy in BCLC stage C. Methods: All patients (n=20) underwent pretreatment 18F-FDG PET/CT and were treated with conversion therapy and surgery. Patients were categorized into responders (n=9) and non-responders (n=11) according to PTR. The parameters of PET/CT, including lesion size, SUVmean (mean standard uptake value), MTV (metabolic tumor volume), TLG (total lesion glycolysis), SUVpeak (peak standard uptake value), and TLR (tumor-to-normal liver standardized uptake value ratio), were calculated. The diagnostic efficacy was evaluated by receiver operating characteristic analysis (ROC). PTR was compared with pretreatment PET/CT parameters by using Spearman correlation analysis. The patients were followed up. Results: There was significant difference in TLR (5.59 ± 1.90 vs. 2.84 ± 1.70, respectively; P=0.003) between responders and non-responders, with the largest area under the curve (sensitivity=100%, specificity=72.7%, AUC=0.899, 95%CI: 0.759-1.000, optimal diagnostic threshold of 3.09). The relationship between 18F-FDG PET/CT parameters and PTR indicated TLR was moderately and positively correlated with pathological treatment response, with correlation coefficients (rs) of 0.69 (P<0.01). During the follow-up, no patients died, and tumor recurrence was found in one of the responders (11.1%). In all 11 non-responders, tumor recurrence was found in six patients (54.5%) and four patients (36.4%) died. Conclusions: TLR may be a powerful marker to predict PTR of HCC patients with BCLC stage C who were treated with conversion therapy.

Tumor angiogenesis at baseline identified by 18F-Alfatide II PET/CT may predict survival among patients with locally advanced non-small cell lung cancer treated with concurrent chemoradiotherapy.

BACKGROUND: The study investigated the predictive value of tumor angiogenesis observed by 18F-ALF-NOTA-PRGD2 II (denoted as 18F-Alfatide II) positron emission tomography (PET)/computed tomography (CT) before concurrent chemoradiotherapy (CCRT) for treatment response and survival among patients with locally advanced non-small cell lung cancer (LA-NSCLC). METHODS: Patients with unresectable stage IIIA or IIIB NSCLC (AJCC Cancer Staging 7th Edition) who received CCRT were included in this prospective study. All patients had undergone 18F-Alfatide PET/CT scanning before CCRT, and analyzed parameters included maximum uptake values (SUVmax) of primary tumor (SUVP) and metastatic lymph nodes (SUVLN) and mean uptake value of blood pool (SUVblood). Tumor-to-background ratios (TBRs) and changes in tumor diameter before and after CCRT (ΔD) were calculated. The ratios of SUVP to SUVblood, SUVLN to SUVblood, and SUVP to SUVLN were denoted as TBRP, TBRLN, and T/LN. Short-term treatment response, progression-free survival (PFS), and overall survival (OS) were evaluated. RESULTS: Of 38 enrolled patients, 28 completed CCRT. SUVP, SUVLN, TBRP, TBRLN and T/LN showed significant correlation with PFS (all P < 0.05). SUVP was negatively correlated with OS (P = 0.005). SUVP and TBRP were higher in non-responders than in responders (6.55 ± 2.74 vs. 4.61 ± 1.94, P = 0.039; 10.49 ± 7.58 vs. 7.73 ± 6.09, P = 0.023). ΔD was significantly greater in responders (2.78 ± 1.37) than in non-responders (-0.16 ± 1.33, P < 0.001). Exploratory receiver operating characteristic curve analysis identified TBRP (area under the curve [AUC] = 0.764, P = 0.018), with a cutoff value of 6.52, as the only parameter significantly predictive of the response to CCRT, with sensitivity, specificity, and accuracy values of 71.43%, 78.57%, and 75.00%, respectively. ROC curve analysis also identified SUVP (AUC = 0.942, P < 0.001, cutoff value 4.64) and TBRP (AUC = 0.895, P = 0.001, cutoff value 4.95) as predictive of OS with high sensitivity (84.21%, 93.75%), specificity (100.00%, 66.67%), and accuracy (89.29%, 82.14%). CONCLUSIONS: Evaluation of tumor angiogenesis by 18F-Alfatide II at baseline may be useful in predicting the short-term response to CCRT as well as PFS and OS in patients with LA-NSCLC.

18F-RGD PET/CT imaging reveals characteristics of angiogenesis in non-small cell lung cancer.

BACKGROUND: The objective of this study was to explore the benefit of 18F-AlF-NOTA-PRGD2 positron emission tomography/computed tomography (denoted as 18F-RGD PET/CT) imaging for determining the clinical pathologic features of non-small cell lung cancer (NSCLC). METHODS: Seventy-two patients with NSCLC (37 cases of adenocarcinoma and 35 cases of squamous carcinoma) were enrolled to receive 18F-RGD PET/CT scanning pretreatment. The peak standard uptake value (SUVpeak), mean standard uptake value (SUVmean), angiogenic tumor volume (ATV) and total lesion angiogenesis (TLA) of tumors were determined using an automated contouring program. Cases were classified according to the tumor, lymph node, metastasis (TNM) stage. RESULTS: Significant differences in ATV and TLA were observed among T1, T2, T3 and T4 cases (ATV, P=0.000; TLA, P=0.000). ATV and TLA also differed significantly among cases of clinical stage I, II, III and IV (ATV, P=0.002; TLA, P=0.011). However, no significant differences in any values were observed between stage III and IV NSCLC cases (SUVpeak, P=0.675; SUVmean, P=0.668; ATV, P=0.52; TLA, P=0.634). All assessed values were higher in squamous cell carcinoma cases than in adenocarcinoma cases (SUVpeak, P=0.045; SUVmean, P=0.014; ATV, P=0.003; TLA, P=0.001). For clinical stage III and IV cases specifically, SUVpeak, SUVmean, and TLA were higher for squamous cell carcinoma than for adenocarcinoma (SUVpeak, P=0.015; SUVmean, P=0.009; TLA, P=0.036).Conclusions: 18F-RGD PET/CT imaging revealed the presence of increased angiogenesis in the tumor microenvironment of NSCLC, especially squamous cell carcinoma, and thus may be valuable in planning therapeutic regimens for individual patients.

Scintillation index of an optical wave propagating through moderate-to-strong oceanic turbulence.

In this paper, based on the extended Rytov theory that combines modified large-scale and small-scale amplitude spatial-frequency filters, we theoretically derive the scintillation index (SI) of the plane and spherical waves by means of the approximate oceanic refractive-index spectrum with the variable eddy diffusivity ratio propagating through moderate-to-strong oceanic turbulence. The mean bit-error rate (BER) of the underwater optical wireless communication systems is analyzed by use of the predicted SI and the gamma-gamma distribution model. Numerical results show that the obtained SI models are in good agreement with the results in weak-fluctuation regions. Also, we find that in weak turbulence, the mean BER drops sharply with the increase in mean signal-to-noise ratio, while in moderate-to-strong turbulence, the situation is opposite. We also note that the mean BER differs between the cases of unity and the variable eddy diffusivity ratio.

Beam-wander analysis in turbulent ocean with the effect of the eddy diffusivity ratio and the outer scale.

In this paper, we theoretically analyze the beam wander variance for the Gaussian beam propagation through weak oceanic turbulence. Particularly, we consider the effect of the eddy diffusivity ratio of salinity to temperature as well as the outer scale on the beam wander. To get to the tractable theoretical results, we first develop an approximate oceanic refractive-index spectrum with the outer scale and variable eddy diffusivity ratio. Based on this spectrum in weak turbulence, we then derive the closed-form expression for the beam wander variance. We present numerical results to show that the beam wander is either overestimated or underestimated as compared to the previous analyses which set the eddy diffusivity ratio to one. In addition, the finite outer scale of turbulence can significantly reduce the beam wander for Gaussian beams.

Underwater optical communication performance under the influence of the eddy diffusivity ratio.

Generally, the eddy diffusivity ratio of salinity to temperature is not equal to one, especially in the upper and mid-to-high latitude ocean. In this paper, the performance of practical underwater optical communication (UOC) systems is investigated by considering the influence of the eddy diffusivity ratio other than one. Specifically, using the Rytov theory in weak turbulence, the aperture-averaged scintillation indices for the plane and spherical waves are derived. The typical performance criteria including the mean signal-to-noise ratio and bit error rate are further studied. It is found that the scintillation index and the associated UOC performance differ between the cases of the unity and variable eddy diffusivity ratio. Such a difference becomes smaller as the receiving aperture increases.

18F-alfatide PET/CT may predict short-term outcome of concurrent chemoradiotherapy in patients with advanced non-small cell lung cancer.

PURPOSE: The study aims to investigate the role of 18F-alfatide positron emission tomography/computed tomography (PET/CT) in predicting the short-term outcome of concurrent chemoradiotherapy (CCRT) in patients with advanced non-small cell lung cancer (NSCLC). METHODS: Eighteen patients with advanced NSCLC had undergone 18F-alfatide PET/CT scans before CCRT and PET/CT parameters including maximum and mean standard uptake values (SUVmax/SUVmean), peak standard uptake values (SUVpeak) and tumor volume (TVPET and TVCT) were obtained. The SUVmax of tumor and normal tissues (lung, blood pool and muscle) were measured, and their ratios were denoted as T/NT (T/NTlung, T/NTblood and T/NTmuscle). Statistical methods included the Two-example t test, Wilcoxon rank-sum test, Receiver-operating characteristic (ROC) curve analysis and logistic regression analyses. RESULTS: We found that SUVmax, SUVpeak, T/NTlung, T/NTblood and T/NTmuscle were higher in non-responders than in responders (P = 0.0024, P = 0.016, P < 0.001, P = 0.003, P = 0.004). According to ROC curve analysis, the thresholds of SUVmax, SUVpeak, T/NTlung, T/NTblood and T/NTmuscle were 5.65, 4.46, 7.11, 5.41, and 11.75, respectively. The five parameters had high sensitivity, specificity and accuracy in distinguishing non-responders and responders. Multivariate logistic regression analyses showed that T/NTlung was an independent predictor of the short-term outcome of CCRT in patients with advanced NSCLC (P = 0.032). CONCLUSIONS: 18F-alfatide PET/CT may be useful in predicting the short-term outcome of CCRT in patients with advanced NSCLC.

Association study of the polymorphisms in the KISS1 gene with central precocious puberty in Chinese girls.

OBJECTIVE: The kisspeptin/GPR54 pathway has been proven to be crucial in the process of puberty onset, yet the polymorphisms in the KISS1 gene and their relationships with central precocious puberty (CPP) have not been investigated. This study was performed to reveal the relationship between the gene and the disease. DESIGN AND METHODS: 272 Chinese Han girls diagnosed to be CPP patients were recruited as Case Group I, 43 unrelated African women as Case Group II, and 288 unrelated normal Chinese Han girls as Control Group. Polymorphism scans of the KISS1 gene were performed for the first time by bidirectional resequencing of the whole gene in a subset of the patients, and then by ligase detection reaction some of the polymorphisms identified were typed in the two groups and the respective haplotypes were constructed. The relationships of the typed polymorphisms and the haplotypes with CPP were evaluated by an association study between genotypes and phenotypes. RESULTS: By resequencing, eight polymorphisms were identified, five of which were typed forming 18 haplotypes. Although one novel nonsynonymous single nucleotide polymorphism substituting one amino acid in kisspeptin (P110T) was found to be statistically related to the disease (P = 0.025), no further supporting evidence has yet been found. The other polymorphisms and all the haplotypes were not found to be related. CONCLUSION: The polymorphism scanning and typing of KISS1 uncovered several potentially meaningful polymorphisms, but the conclusion was not solid and further studies are necessary for function validation of these polymorphisms.

Effects of additives on efficiency and specificity of ligase detection reaction.

Ligase detection reaction (LDR) is adaptable to a wide variety of applications ranging from scientific research to clinical diagnosis, especially in the field of nucleotide polymorphism discrimination and analysis. Efficiency and specificity of LDR are the most two important characteristics that influence its application. To improve the specificity or efficiency of ligase, optimization of the design of LDR probes and the reaction of LDR were investigated previously by most researchers. But the effects of additives on LDR have not been reported. In this study, the effects of additives (DMSO, Tween-20, glycerol, formamide, and PEG- 6000) on LDR efficiency and specificity were investigated. The results showed that all of these compounds, except for Tween-20, could improve the specificity of LDR. PEG-6000 was proved to be the best additive among the five tested with an optimal concentration of 5% at which the highest yield was obtained with a relatively improved specificity.

Association study of six activity SNPS in adrenal steroid hormone metabolism and IBM related genes with precocious puberty in Chinese girls.

OBJECTIVES: In order to investigate whether the variances in the candidate genes (Insulin receptor substrate IRS-1, beta3-adrenergic receptor ADRB3, 3 beta-hydro-xysteroid dehydrogenase HSD3B2, glucocorticoid receptor GRL and 21-hydroxylase CYP21) which affect the metabolism of adrenal steroids hormone and body composition, are associated with precocious puberty in Chinese girls. METHODS: PCR-RFLP analysis method was applied in the typing of six activity SNPs in five genes in two groups: 176 precocious puberty girls as case and 192 healthy girls as control. RESULTS: The typing results showed that the frequencies of the allele CYP21 L282 polymorphism were 32.7% and 32.6% in case and control groups (P=0.518), respectively. For IRS-1 R972, they were 0.6% in cases and 2.3% in controls (P=0.043), for ADRB3 R64, 13.6% in cases and 12% in controls (P=0. 378), and for GRL S363, 7.4% in cases and 5.73% in controls (P=0.335). No sample in the two groups carries the variation of CYP21 I172N and HSD3B2 L236S. CONCLUSION: Among these six activity SNPs in five candidate genes, IRS-1 972R was statistically associated with the onset time of puberty in Chinese girls. In order to confirm whether the candidate genes have any other activity SNPs that are associated with the onset time of puberty in Chinese girls, resequencing of these candidate genes is needed in following time.

A modified simple RFLP-PCR method for single nucleotide polymorphism (SNP) typing

We describe a modified single nucleotide polymorphism (SNP) typing method based on the restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). This is a simple, economical method without the need for special equipment. For most SNP loci, a common restriction endonuclease (Hind III, EcoR I or BamH I) recognizing site (RER) can be introduced into one allelic form, but not the other by two rounds of mismatched PCR. The flanking regions can be changed by as many as five bases after PCR amplification with specially designed mismatching primers so the genotypes can be distinguished after digestion of the PCR products with corresponding endonucleases.

Association study of four activity SNPs of CYP3A4 with the precocious puberty in Chinese girls.

CYP3A4 plays an important role in the metabolism of a variety of endogenous and exogenous compounds. Earlier studies revealed that a high-activity variation of the CYP3A4 gene, CYP3A4*1B is significantly associated with the precocious puberty in girls. Other three variations, CYP3A4*4, CYP3A4*5 and CYP3A4*6, which were found in a study carried out in a Chinese population in Taiwan, were reported to down-regulate the enzymatic activity of CYP3A4. The four activity SNPs were typed in our study in two groups of Chinese girls: 176 girls with precocious puberty as the case group, and 192 normal girls as the control group. No variations of CYP3A4*1B and CYP3A4*4 were found in all the cases and controls. Heterozygous of CYP3A4*5 was found in five subjects of the 192 controls but none in the cases, heterozygous of CYP3A4*6 was found in two subjects of the controls but none in the cases. Fisher's exact test showed that the variation of CYP3A4*5 was associated with the onset of puberty in Chinese girls (P-trend=0.038), while the variation of CYP3A4*6 was not associated with the onset of puberty in Chinese girls (P-trend=0.272). The result suggests that these mutations in the CYP3A4 gene have no contribution to the early onset of puberty in Chinese girls, but are related in some way with the puberty development in Chinese girls.