Positive effects of brisk walking and Tai Chi on cognitive function in older adults: An fNIRS study.

Exercise has shown to have beneficial effects on cognition in older adults. The purpose of this study was to investigate the cortical hemodynamic responses during the word-color Stroop test (WCST) prior and after acute walking and Tai Chi exercise by functional near-infrared spectroscopy (fNIRS). Twenty participants (9 males, mean age 62.8 ± 5.2), first underwent a baseline WCST test, after which they took three WCST tests in a randomized order, (a) after sitting rest (control), (b) after 6 minutes performing Tai Chi Quan, and (c) after a bout of 6 minutes brisk walking. During these four WCST tests cortical hemodynamic changes in the prefrontal area were monitored with fNIRS. Both brisk walking and Tai Chi enhanced hemodynamic activity during the Stroop incongruent tasks, leading to improved cognitive performance (quicker reaction time). Brisk walking induced a greater hemodynamic activity in the right dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex (VLPFC) area, whereas Tai Chi induced a greater bilateral hemodynamic activity in the DLPFC and VLPFC areas. The present study provided empirical evidence of enhanced hemodynamic response in task- specific regions of the brain that can be achieved by a mere six minutes of brisk walking or Tai Chi in older adults.

Prefrontal cortical hemodynamics and functional network organization during Tai Chi standing meditation: an fNIRS study.

Introduction: Tai Chi standing meditation (Zhan Zhuang, also called pile standing) is characterized by meditation, deep breathing, and mental focus based on theories of traditional Chinese medicine. The purpose of the present study was to explore prefrontal cortical hemodynamics and the functional network organization associated with Tai Chi standing meditation by using functional near-infrared spectroscopy (fNIRS). Methods: Twenty-four channel fNIRS signals were recorded from 24 male Tai Chi Quan practitioners (54.71 ± 8.04 years) while standing at rest and standing during Tai Chi meditation. The general linear model and the SPM method were used to analyze the fNIRS signals. Pearson correlation was calculated to determine the functional connectivity between the prefrontal cortical sub-regions. The small world properties of the FC networks were then further analyzed based on graph theory. Results: During Tai Chi standing meditation, significantly higher concentrations of oxygenated hemoglobin were observed in bilateral dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC), frontal eye field (FEF), and pre-motor cortex (PMC) compared with the values measured during standing rest (p < 0.05). Simultaneously, significant decreases in deoxygenated hemoglobin concentration were observed in left VLPFC, right PMC and DLPFC during Tai Chi standing meditation than during standing rest (p < 0.05). Functional connectivity between the left and right PFC was also significantly stronger during the Tai Chi standing meditation (p < 0.05). The functional brain networks exhibited small-world architecture, and more network hubs located in DLPFC and VLPFC were identified during Tai Chi standing meditation than during standing rest. Discussion: These findings suggest that Tai Chi standing meditation introduces significant changes in the cortical blood flow and the brain functional network organization.

Concentration Changes of Peripheral Blood Mesenchymal Stem Cells of Sprague Dawley Rats during Distraction Osteogenesis.

OBJECTIVES: To observe the changes in the concentrations of circulating peripheral blood mesenchymal stem cells (PBMSCs) in Sprague Dawley (SD) rats and explore the pattern of changes in PBMSCs during the process of distraction osteogenesis. METHODS: SD rats were randomly divided into the osteotomy with lengthening group (lengthening group), the osteotomy without lengthening group (osteotomy group), and the blank control group (control group). Each group included 24 rats. Percutaneous pinning with external fixation of the left femur was carried out in lengthening group and osteotomy group, but control group received no surgical treatment. On day 5 after operation, continuous traction was carried out at a rate of 0.25 mm/d in lengthening group, while no traction was carried out in osteotomy group. Peripheral blood was collected from all rats on days 1, 3, 7, and 16 after the start of traction. PBMSCs were isolated by density gradient centrifugation. CD105, CD34, and CD45 were selected as cell surface markers. The concentration of PBMSCs was detected by flow cytometry and compared between groups at different time points. X-ray films were taken during and after the operation to observe whether the osteotomy end was pulled and the growth and mineralization of the new bone in the osteogenic area of the femur. Color ultrasound was used to monitor the width of the distraction space, the formation of new bone, and the blood supply of soft tissue around the distraction. RESULTS: All rats were able to tolerate the operation well, and the external fixation was firm and reliable. X-ray showed that, in lengthening group, the distraction space of femur gradually widened and new bone gradually formed in the distraction space; after 8 weeks, the samples were taken out, which showed that the new bone tissue in the lengthened area healed well. In osteotomy group, the average healing time of osteotomy was (7.12 ± 0.78) weeks. Ultrasonic examination showed that after the end of traction, the high echo callus shadow was seen in the traction space, and the blood flow signal was obviously rich at an earlier stage. In lengthening group and osteotomy group, the average concentrations of PBMSCs (3.02% ± 0.87% vs 2.95% ± 0.74%, respectively) were significantly increased in the early stage after osteotomy, and the average concentrations of PBMSCs on days 3, 7, and 16 after the start of traction were 5.34% ± 1.13% vs 3.28% ± 1.22%; 6.41% ± 1.05% vs 3.16% ± 0.92%; and 5.94% ± 1.23% vs 1.48% ± 0.52%, respectively. The concentration of PBMSCs in peripheral blood of lengthening group and osteotomy group was the same at osteotomy stage, and the difference between the two groups was not statistically significant (P > 0.05). After that, compared with lengthening group, the concentration of PBMSCs in osteotomy group gradually decreased and maintained at a certain level; the difference between the two groups was statistically significant (P < 0.05). CONCLUSIONS: Distraction osteogenesis of femur can significantly increase PBMSCs in SD rats and participate in the process of bone formation.

Fluorodeoxyglucose uptake in laryngeal carcinoma is associated with the expression of glucose transporter-1 and hypoxia-inducible-factor-1α and the phosphoinositide 3-kinase/protein kinase B pathway.

High fluorodeoxyglucose (FDG) uptake by human carcinomas, including head and neck cancers, is associated with a poor prognosis. Glucose transporter-1 (Glut-1) is believed to be an intrinsic marker of hypoxia in malignant tumors. The expression of hypoxia-inducible factor-1α (HIF-1α) and correlated target genes, including Glut-1, is regulated by the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway. However, it remains unclear whether the PI3K/Akt signaling pathway is involved in regulating FDG uptake directly. In the present study, 24 consecutive patients with laryngeal carcinoma were examined pre-operatively and the standardized uptake values (SUV) of the laryngeal carcinomas were determined. Glut-1, HIF-1α, PI3K and phosphorylated-Akt (p-Akt) expression was detected by immunohistochemical staining of paraffin sections from the tumor specimens. Associations among SUVmax, Glut-1, HIF-1α, PI3K and p-Akt protein expression and the other clinical parameters were analyzed. The univariate analyses revealed a significantly shorter survival time along with higher HIF-1α (P=0.018) and PI3K (P=0.008) expression, but the survival time was not significantly correlated with Glut-1 or p-Akt expression. The multivariate analysis demonstrated that higher SUVmax (P=0.043) and PI3K expression (P=0.012) were significantly correlated with a poor survival time. Spearman's rank analysis showed significant correlations between SUVmax and HIF-1α (r=0.577; P=0.003), PI3K (r=1.0; P<0.0001) and p-Akt (r=0.577; P=0.003) expression. PI3K was associated with poorly- and moderately-differentiated laryngeal carcinoma (P=0.012). In conclusion, a high SUVmax indicates a poor prognosis for laryngeal carcinoma. Also, a high SUVmax may be associated with the increased expression of Glut-1, HIF-1α, PI3K and p-Akt.

Simple automated radiosynthesis of 10-[11C]methoxy-20(S)-camptothecin and biodistribution in normal mice.

10-[(11)C]methoxy-20(S)-camptothecin was synthesized automatically. The radiochemical yield was 30%-50% (all calculated at EOB, n=20) with [(11)C]methyl triflate as a methylating agent. The radiochemical purity was greater than 96%, and the specific activity was 8.72±2.18 GBq/µmoL at EOS. Biodistribution showed that 10-[(11)C]methoxy-20(S)-camptothecin is characterized by quick clearance from the blood and by significant uptake in the liver (5.72±1.92% ID/g at 15 min), intestines (2.43±0.38% ID/g at 15 min), and kidney (1.57±0.85% ID/g at 15 min). Micro-PET imaging clearly showed high radioactivity accumulation in liver, intestines and bladder, indicating that the primary modes of excretion of the radiotracer are through the hepatobiliary system and, to a lesser extent, through the renal system.

¹8F-fluorodeoxyglucose positron emission tomography/computed tomography as an effective diagnostic workup in cervical metastasis of carcinoma from an unknown primary tumor.

PURPOSE: The purpose of this study is to assess the potential of ¹8F-fluorodeoxyglucose (¹8FDG) positron emission tomography/computed tomography (PET/CT) imaging for the diagnosis of cervical metastasis of carcinoma of an unknown primary tumor (CUP) and to determine whether the maximum standardized uptake value (SUV(max)) is a prognostic factor. METHODS: Twenty-five consecutive patients with cervical metastasis of CUP were retrospectively analyzed by PET/CT between July 2007 and July 2011. RESULTS: FDG PET/CT suggested a primary tumor in 21 out of 25 patients (84.0%). The sensitivity of FDG PET/CT in detecting the primary tumor was 73.3% (11 of 15), and the positive predictive value was 52.4% (11 of 21). The median follow-up duration of survival patients was 10.4 months (range: 0-30 months). The estimated 2-year overall survival rate of all patients was 50.0%. Univariate analyses did not reveal a significant difference in overall survival between the group of 11 patients identified by pathology and the 14 patients not identified by pathology (overall survival was 57.1% and 49.1%, respectively; p=0.468). The median SUV(max) was 7.6. In the log-rank test, patients with a low SUV(max) (≤ 7.0) in cervical lymph nodes had a significantly higher survival rate at 2 years (87.5% vs. 21.2%; p=0.007) than patients with a high SUV(max) (>7.0). CONCLUSIONS: Although our study was inconclusive due to the small sample size, our results suggest that FDG PET/CT may be an effective diagnostic workup in the cervical metastasis of carcinoma from an unknown primary tumor (UPT). In the present study, SUV(max) of PET/CT in the cervical lymph node may serve as a prognostic factor of cervical metastasis of carcinoma from a UPT based on the limited number of patients. Further studies are needed to confirm these findings.

Elevated uptake of 18F-FDG in PET/CT imaging of a nocardial pleural nodule.

18-Fluoredeoxyglucose position emission tomography and computed tomography ((18)F-FDG PET/CT) scanning has been widely used in the assessment of malignancy. We report here an increased (18)F-FDG uptake in pleural nodules in the PET/CT scan images of a patient having recurrent fever and chest pain. Further studies with bacterial culture and histopathology of biopsy confirmed the lesions as nocardial infection. To our knowledge, it is the first report of PET /CT findings in pleural multiple irregular nodules with nocardial infection. Our study suggests that a combination of FDG-PET/CT scanning and pathological study may be considered in distinguishing uncommon benign lesions in the lung.

A meta-analysis of fluorodeoxyglucose-positron emission tomography versus scintigraphy in the evaluation of suspected osteomyelitis.

AIM: Functional nuclear medicine imaging techniques have become particularly important in the diagnosis of osteomyelitis. The aim of our study was to perform a meta-analysis to obtain a reliable estimate of the diagnostic performance of fluorodeoxyglucose-positron emission tomography (FDG-PET), three-phase bone scintigraphy, leukocyte scintigraphy, and monoclonal antigranulocyte antibody (MOAB) scintigraphy in the assessment of suspected osteomyelitis and to perform pairwise comparisons of the diagnostic accuracy between these different imaging modalities. PATIENTS AND METHODS: A total of 23 studies representing 851 examinations that were published from January 1980 to October 2010 were reviewed. These studies evaluated the role of FDG-PET, three-phase bone scintigraphy, leukocyte scintigraphy, and MOAB scintigraphy in the assessment of suspected osteomyelitis. Systematic methods were used to identify, select, and evaluate the methodological quality of the studies and to summarize the overall findings of sensitivity and specificity. Two-sample Z-tests were conducted to evaluate for differences in sensitivity, specificity, area under the curve (AUC), and the Q* index between any two diagnostic modalities. RESULTS: The FDG-PET had a pooled sensitivity of 0.923, specificity of 0.920, and AUC of 0.9666, whereas for bone scintigraphy, the corresponding values were 0.827, 0.446, and 0.6514, respectively, for leukocyte scintigraphy, the corresponding values were 0.742, 0.881, and 0.9139, respectively, and for MOAB, the corresponding values were 0.883, 0.705, and 0.8897, respectively. Our meta-analysis did not find statistically significant differences in the sensitivity, specificity, AUC, and Q* index between FDG-PET and leukocyte scintigraphy. CONCLUSION: Leukocyte scintigraphy can be used with satisfactory diagnostic accuracy for detecting osteomyelitis when positron emission tomography systems are not available. The FDG-PET appears to be superior in terms of accuracy compared with other radionuclide imaging modalities.

A meta-analysis of the value of fluorodeoxyglucose-PET/PET-CT in the evaluation of fever of unknown origin.

BACKGROUND AND PURPOSE: The diagnosis of patients with fever of unknown origin (FUO) remains a challenging medical problem for internal medicine. A reliable estimate of the diagnostic performance of FDG-PET and FDG-PET/CT in the assessment of FUO unidentified by conventional workup has never been systematically assessed, and present systematic review was aimed at this issue. METHODS: A systematic search for relevant studies was performed of the PubMed, Embase, and Cochrane databases. Methodological quality of each study was assessed. Sensitivity, specificity and area under the curve (AUC) were meta-analyzed. Subgroup analyses were performed if results of individual studies were heterogeneous. RESULTS: The inclusion criteria were met by nine studies. Overall, the studies had good methodological quality. Pooled sensitivity and specificity of FDG-PET for the detection of FUO were 0.826 (95% CI; 0.729-0.899) and 0.578 (95% CI; 0.488-0.665), respectively, and the AUC was 0.810. Heterogeneity among the results of FDG PET studies was present (QSE=12.40, I2=67.7%; QSp=35.98, I2=88.9%). Pooled sensitivity and specificity of FDG-PET/CT were 0.982 (95% CI; 0.936-0.998) and 0.859 (95% CI; 0.750-0.934), respectively, and the AUC was 0.947. We did not find any statistical differences in the AUC and Q* index between FDG-PET and FDG-PET/CT (Z=0.566, p>0.05). CONCLUSIONS: Although the FDG-PET studies that we examined were heterogeneous, FDG-PET appears to be a sensitive and promising diagnostic tool for the detection of the causes of FUO. FDG-PET/CT should be considered among the first diagnostic tools for patients with FUO in whom conventional diagnostics have been unsuccessful.

[Value of 18F-FDG-PET/CT in diagnosis of classic fever of unknown origin].

OBJECTIVE: To evaluate the application of (18)F-FDG PET/CT in diagnosis of classic fever of unknown origin. METHODS: A total of 27 consecutive patients with classic fever of unknown origin (FUO) (19 men, 8 women; aged 24-82 y) underwent (18)F-FDG PET/CT scans. The images were interpreted by visual inspection and semiquantitative analysis(standardized uptake value, SUV). Final diagnosis was based on histopathology or clinical follow-up. RESULTS: The cause of FUO was confirmed by followed investigations in 21 of 27 cases after PET/CT scan, including 10 cases of infection, 4 of noninfectious inflammation, 4 of malignancies and 3 of miscellaneous disorders; and remaining 6 cases were still confirmed FUO. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 100.0 %, 83.3%, 83.3%, 100.0% and 96.3%, respectively. CONCLUSION: For patients with fever of unknown origin, (18)F-FDG-PET/CT can be a sensitive, reliable imaging modality. It is suggested that (18)F-FDG-PET/CT should be considered earlier in detecting the causes of FUO, which is difficultly diagnosed by conventional modalities.

Value of 18F-FDG-PET/PET-CT in differentiated thyroid carcinoma with radioiodine-negative whole-body scan: a meta-analysis.

AIM: The aim of this study was to evaluate the diagnostic accuracy of 18F-fluorodeoxyglucose-PET (FDG-PET) and FDG-PET/computed tomography (CT) in the detection of recurrent or metastatic differentiated thyroid carcinoma (DTC) that was not identified by radioiodine whole-body scintigraphy (WBS). PATIENTS AND METHODS: A total of 25 studies (comprising 789 patients) that were published from January 1990 to September 2008 were reviewed. These studies evaluated the role of FDG-PET and FDG-PET/CT in the detection of recurrent or metastatic DTC that radioiodine WBS failed to detect. Systematic methods were used to identify, select, and evaluate the methodological quality of the studies and to summarize the overall findings of sensitivity and specificity. RESULTS: In total, 17 studies with 571 patients who had recurrent or metastatic DTC and a radioiodine-negative whole-body scan were collected, and the overall patient-based sensitivity and specificity of FDG-PET were 0.835 [95% confidence interval (CI): 0.791-0.873] and 0.843 (95% CI: 0.791-0.886), respectively. Of these studies, six included lesion-based data, totaling 237 lesions, and the pooled lesion-based sensitivity and specificity were 0.916 (95% CI: 0.863-0.953) and 0.775 (95% CI: 0.660-0.865), respectively. The pooled sensitivity and specificity in the DTC patients who presented with elevated serum thyroglobulin and negative 131I scan were 0.885 (95% CI: 0.828-0.929) and 0.847 (95% CI: 0.715-0.934), respectively. In the six studies where the 165 patients were diagnosed by using FDG-PET/CT, pooled sensitivity and specificity were 0.935 (95% CI: 0.870-0.973) and 0.839 (95% CI: 0.723-0.920), respectively. CONCLUSION: FDG-PET is especially effective in detecting patients with elevated thyroglobulin levels and normal radioiodine WBS; FDG-PET/CT is a more sensitive method in the follow-up of thyroid cancer recurrence or metastases, particularly in those with negative WBS.