Evaluation for Parkinsonian Bradykinesia by deep learning modeling of kinematic parameters.

A wearable sensor system is available for monitoring of bradykinesia in patients with Parkinson's disease (PD), however, it remains unclear whether kinematic parameters would reflect clinical severity of PD, or would help clinical diagnosis of physicians. The present study investigated whether the classification model using kinematic parameters from the wearable sensor may show accordance with clinical rating and diagnosis in PD patients. Using the Inertial Measurement Units (IMU) sensor, we measured the movement of finger tapping (FT), hand movements (HM), and rapid alternating movements (RA) in 25 PD patients and 21 healthy controls. Through the analysis of the measured signal, 11 objective features were derived. In addition, a clinician who specializes in movement disorders viewed the test video and evaluated each of the Unified Parkinson's Disease Rating Scale (UPDRS) scores. In all items of FT, HM, RA, the correlation between the linear regression score obtained through objective features (angle, period, coefficient variances for angle and period, change rates of angle and period, angular velocity, total angle, frequency, magnitude, and frequency × magnitude) and the clinician's UPDRS score was analyzed, and there was a significant correlation (rho > 0.7, p < 0.001). PD patients and controls were classified by deep learning using objective features. As a result, it showed a high performance with an area under the curve (AUC) about as high as 0.9 (FT Total = 0.950, HM Total = 0.889, RA Total = 0.888, ALL Total = 0.926. This showed similar performance to the classification result of binary logistic regression and neurologist, and significantly higher than that of family medicine specialists. Our results suggest that the deep learning model using objective features from the IMU sensor can be usefully used to identify and evaluate bradykinesia, especially for general physicians not specializing in neurology.

Limitations of dual-energy CT in the detection of monosodium urate deposition in dense liquid tophi and calcified tophi.

OBJECTIVE: Dual-energy CT (DECT) detection of monosodium urate (MSU) crystal deposition has demonstrated good sensitivity and specificity in patients with established gout. However, limitations have been reported with early disease and with low urate burden. We aimed to study the performance of DECT in the detection and quantification of MSU deposition in solid and liquid tophi. MATERIALS AND METHODS: Patient-derived solid and liquid tophi, suspensions of commercial synthetic, and in-house synthetic MSU crystals were prepared at varying concentrations. DECT was performed at 80 kVp and 150 kVp, and post-processed using Syngo Via gout software (Siemens) that color-coded urate and cortical bone as green and purple, respectively. DECT findings were correlated with ultrasound and microscopic findings. The protocol was reviewed by IRB and considered a non-human subject research. RESULTS: DECT did not detect urate deposition in either patient-derived liquid tophi or in-house synthetic crystals at any concentration. Lowering the post-processing minimum threshold increased the detection of in-house synthetic crystals but did not change the detection of patient-derived liquid tophi. Areas of calcium-rich purple color-coded regions, masking detection of urate, within the solid tophi and surrounding liquid tophi were noted on DECT. Histology showed co-presence of calcium along with MSU deposition in these. CONCLUSION: This study illustrates important limitations of DECT for liquid tophi due to subthreshold CT attenuation and for calcified tophi due to the obscuration of urate by calcium. Urate may be either undetectable or underestimated by DECT when these conditions are present.

JOURNAL CLUB: Value of Quantitative FDG PET/CT Volumetric Biomarkers in Recurrent Colorectal Cancer Patient Survival.

OBJECTIVE: The purpose of this study was to evaluate the impact of quantitative PET parameters in the overall survival of patients with recurrent colorectal cancer. MATERIALS AND METHODS: A total of 105 patients with a biopsy-proven recurrence of colorectal cancer who underwent PET/CT were included in the study. A gradient segmentation method was used to calculate maximum and peak standardized uptake values (SUVmax, SUVpeak), total lesion glycolysis (TLGtotal), and metabolic tumor volume (MTVtotal). These parameters were measured for each recurrent lesion at the primary, locoregional, and distant sites. The median follow-up time was 31.3 months. Overall survival (OS) was the primary outcome and was calculated using Kaplan-Meier survival plots and Cox regression analyses. RESULTS: The mean ± SD for SUVmax, SUVpeak, TLGtotal, and MTVtotal of the included patients was 7.3 ± 5.3, 5.3 ± 3.3, 280.8 ± 1181 g, and 79.8 ± 294 mL, respectively. The median OS for patients who were alive was 50 months in comparison with 23.4 months among patients who died. Age (p = 0.041), tumor grade (p = 0.010), median TLG (p = 0.031), and median MTV (p = 0.009) remained significantly associated with OS in the multivariate Cox regression analysis. Kaplan-Meier survival analysis performed on the basis of the median PET/CT parametric values showed that SUVmax (threshold, 5.63; hazard ratio [HR] = 1.7; 95% CI, 1-2.8; p = 0.02), MTVtotal (threshold, 13.85 mL; HR = 2.2; 95% CI, 1.3-3.9; p = 0.003), and TLGtotal (threshold, 36.14 g; HR = 1.9; 95% CI, 1.1-3.3; p = 0.01) were significant predictors of OS during follow-up. An integrated risk stratification model with SUVmax and MTVtotal into three subgroups predicted patient survival outcomes (HR = 1.8; 95% CI, 1.25-2.65; log-rank p = 0.003). CONCLUSION: SUVmax, MTVtotal, TLGtotal, and integrated score with FDG avidity and total tumor burden provide survival information for patients with biopsy-proven recurrent colorectal cancer.

Intratherapy or Posttherapy FDG PET or FDG PET/CT for Patients With Head and Neck Cancer: A Systematic Review and Meta-analysis of Prognostic Studies.

OBJECTIVE: The objective of this study was to determine the predictive value of intra-therapy or posttherapy FDG PET or FDG PET/CT with regard to overall survival (OS) and event-free survival (EFS) outcomes for patients with head and neck cancer (HNC). MATERIALS AND METHODS: A systematic search of the MEDLINE and EMBASE databases was performed. Studies in which PET/CT was performed during or after completion of primary therapy and for which survival outcomes were reported were included. OS and EFS were considered as outcomes. The pooled estimates of hazard ratios (HRs) and Mantel-Haenszel risk ratios (RRs) were generated for summary effects. RESULTS: Twenty-six studies were eligible for inclusion. The pooled HRs for OS (nine studies, 600 patients) and EFS (eight studies, 479 patients) were 3.55 (95% CI, 2.35-5.37) and 4.73 (95% CI, 2.61-8.56), respectively. Results from the RR analyses, including all 26 studies, showed that intratherapy or posttherapy PET/CT could significantly predict the 2-year and 3- to 5-year risk of death or disease progression. A positive PET result was associated with a more-than-sixfold increase in the risk of death within 2 years (2-year RR, 6.19 [95% CI, 3.04- 12.62]), which is attenuated--but remains significant--with longer follow-up (3- to 5-year RR, 2.42 [95% CI, 1.76-3.32]). The estimated pooled RRs for 2-year mortality were 8.31 (95% CI, 3.83-18.01) for posttherapy PET/CT versus 3.99 (95% CI, 1.43-11.10) for intratherapy PET/CT. CONCLUSION: Positive results of intratherapy or posttherapy PET/CT examinations strongly predict the risk of adverse events and death, particularly within 2 years but also up to 5 years, for patients with HNC.

A machine learning-based approach for predicting renal function recovery in general ward patients with acute kidney injury.

Background: Acute kidney injury (AKI) is a significant challenge in healthcare, imposing a significant social burden. While there are considerable researches dedicated to AKI and the recovery of AKI patients, a crucial factor in their prognosis, is often overlooked. Thus, our study aims to address this issue through the development of a machine learning-based approach to predict restoration of kidney function in patients with AKI. Methods: Our study encompassed data from 350,345 cases, derived from two hospitals. AKI was classified in accordance with the Kidney Disease: Improving Global Outcomes. Criteria for recovery were established as either a 33% decrease in serum creatinine levels at AKI onset or reduction to values lower than the baseline, which was initially employed for the diagnosis of AKI. We employed various machine learning models, selecting 43 pertinent features for analysis. Results: Our analysis contained 7,041 and 2,929 patients' data from internal cohort and external cohort respectively. The Categorical Boosting model demonstrated significant predictive accuracy, as evidenced by an internal area under the receiver operating characteristic curve (AUROC) of 0.7860, and an external AUROC score of 0.7316, thereby confirming its robustness in predictive performance. SHapley Additive exPlanations values were employed to explain key factors impacting recovery of renal function in AKI patients, highlighting factors such as elevated urine specific gravity, body temperature, and phosphorus levels. Conclusion: This study presented a novel machine learning framework for predicting renal function recovery in patients with AKI, offering a deeper understanding of the key variables affecting recovery. The clinical applicability of the model was assessed across distinct hospital settings, which revealed variations in its efficacy. Although the model exhibited favorable outcomes, the necessity for further enhancements and the incorporation of more diverse datasets is imperative for its application in real-world scenarios.

Adaptive statistical iterative reconstruction and Veo: assessment of image quality and diagnostic performance in CT colonography at various radiation doses.

OBJECTIVES: To evaluate the diagnostic performance of computed tomography (CT) colonography (CTC) reconstructed with different levels of adaptive statistical iterative reconstruction (ASiR, GE Healthcare) and Veo (model-based iterative reconstruction, GE Healthcare) at various tube currents in detection of polyps in porcine colon phantoms. METHODS: Five porcine colon phantoms with 46 simulated polyps were scanned at different radiation doses (10, 30, and 50 mA s) and were reconstructed using filtered back projection (FBP), ASiR (20%, 40%, and 60%) and Veo. Eleven data sets for each phantom (10-mA s FBP, 10-mA s 20% ASiR, 10-mA s 40% ASiR, 10-mA s 60% ASiR, 10-mA s Veo, 30-mA s FBP, 30-mA s 20% ASiR, 30-mA s 40% ASiR, 30-mA s 60% ASiR, 30-mA s Veo, and 50-mA s FBP) yielded a total of 55 data sets. Polyp detection sensitivity and confidence level of 2 independent observers were evaluated with the McNemar test, the Fisher exact test, and receiver operating characteristic curve analysis. Comparative analyses of overall image quality score, measured image noise, and interpretation time were also performed. RESULTS: Per-polyp detection sensitivities and specificities were highest in 10-mA s Veo, 30-mA s FBP, 30-mA s 60% ASiR, and 50-mA s FBP (sensitivity, 100%; specificity, 100%). The area-under-the-curve values for the overall performance of each data set was also highest (1.000) at 50-mA s FBP, 30-mA s FBP, 30-mA s 60% ASiR, and 10-mA s Veo. Images reconstructed with ASiR showed statistically significant improvement in per-polyp detection sensitivity as the percent level of per-polyp sensitivity increased (10-mA s FBP vs 10-mA s 20% ASiR, P = 0.011; 10-mA s FBP vs 10-mA s 40% ASiR, P = 0.000; 10-mA s FBP vs 10-mA s 60% ASiR, P = 0.000; 10-mA s 20% ASiR vs 40% ASiR, P = 0.034). Overall image quality score was highest at 30-mA s Veo and 50-mA s FBP. The quantitative measurement of the image noise was lowest at 30-mA s Veo and second lowest at 10-mA s Veo. There was a trend of decrease in time required for image interpretation as the percent level of ASiR increased, and ASiR or Veo was used instead of FBP. However, differences from comparative analyses of overall image quality score, measured image noise, and interpretation time did not reach statistical significance. CONCLUSION: ASiR and Veo showed improved diagnostic performance with excellent sensitivity and specificity with less image noise and good image quality compared with FBP reconstruction of same radiation dose. Our study confirmed feasibility of low-dose CTC with iterative reconstruction as a promising screening tool with excellent diagnostic performance similar to that of the standard-dose CTC with FBP.

Two-stage binary classifier for neuromuscular disorders using surface electromyography feature extraction and selection.

If surface electromyography (sEMG) can be used to determine neuromuscular disorders, it can diagnose conditions more easily than needle electromyography. In this study, sEMG during maximum voluntary isometric contraction and repetitive exercise was measured, and normal, myopathy, and neuropathy were classified with high accuracy using these signals. First, a two-stage binary classifier model was constructed to classify the patient group and the normal group and categorize the cases assigned to the patient group into myopathy and neuropathy groups. To this end, features related to muscle activity and muscle fatigue were extracted using activity analysis and frequency analysis of the sEMG signal. Since the features for high performance are different for each classifier, the features with statistical differences in the data of each class were selected for each classifier. The selected features and a two-stage binary classifier were distinguished with an accuracy of 86.9%. This shows an accuracy higher than 82.3%, which was found for the two-stage binary classifier without feature selection and 73.9% of the multi-classifier. Through this, the possibility of using sEMG to diagnose neuromuscular disorders was confirmed.

Virtual evaluation of selected cervical lymph nodes with three-dimensional ultrasound in thyroid cancer patients after thyroidectomy.

BACKGROUND: We evaluated the usefulness of three-dimensional (3D) ultrasound of cervical lymph nodes (LN), when two-dimensional (2D) ultrasound evaluation is not sufficient to clearly evaluate lymph node characteristics, in thyroid cancer patients being followed after thyroidectomy. METHODS: Two readers retrospectively analyzed 2D and 3D images of 147 LNs; LNs were categorized as normal, reactive, suspicious, or indeterminate, and confidence level was rated. Results were compared to cytological/clinical data. Inter-reader agreement was calculated. RESULTS: Addition of 3D ultrasound significantly increased specificity (0.787 with 2D ultrasound vs 0.905 with 2D + 3D ultrasound for reader 1, P = .009; 0.701 with 2D ultrasound vs 0.898 with 2D + 3D ultrasound for reader 2, P = .01). Addition of 3D ultrasound significantly increased confidence level of readers (P < .001). Inter-reader agreement in LN categorization was almost perfect with 2D + 3D ultrasound. CONCLUSION: 3D ultrasound of cervical LNs enables better demonstration of imaging features that are important in differentiating benign and malignant LNs. These improvements can potentially obviate the need for FNA in post thyroidectomy cancer patients.

In vitro and ex vivo activity of new derivatives of acetohydroxyacid synthase inhibitors against Mycobacterium tuberculosis and non-tuberculous mycobacteria.

Sulfometuron methyl (SM) is an inhibitor of acetohydroxyacid synthase (AHAS), the first common enzyme in the branched-chain amino acid biosynthetic pathway, and shows activity against Mycobacterium tuberculosis both in vitro and in vivo. To develop AHAS inhibitor derivatives with more potent activity, 100 sulfonylurea analogues were screened for antimycobacterial activity against M. tuberculosis and non-tuberculous mycobacteria (NTM), and then evaluated for intracellular activity using mouse macrophages. Three new compounds with antimycobacterial activity comparable with that of SM were identified. These compounds exhibit significant activity against intracellular M. tuberculosis (including the drug-resistant M. tuberculosis strains), and NTM Mycobacterium abscessus and Mycobacterium kansasii, respectively.

Validity and Reliability of the Newly Developed Surface Electromyography Device for Measuring Muscle Activity during Voluntary Isometric Contraction.

OBJECTIVE: The purpose of this study was to establish the validity and reliability of the newly developed surface electromyography (sEMG) device (PSL-EMG-Tr1) compared with a conventional sEMG device (BTS-FREEEMG1000). METHODS: In total, 20 healthy participants (10 males, age 30.3 ± 2.9 years; 10 females, age 22.3 ± 2.7 years) were recruited. EMG signals were recorded simultaneously on two devices during three different isometric contractions (maximal voluntary isometric contraction (MVIC, 40% MVIC, 80% MVIC)). Two trials were performed, and the same session was repeated after 1 week. EMG amplitude recorded from the dominant biceps brachii (BB) and rectus femoris (RF) muscles was analyzed for reliability using intrasession intraclass correlation coefficient (ICC). Concurrent validity of the two devices was determined using Pearson's correlation coefficient. RESULTS: Nonnormalized sEMG data showed moderate to very high reliability for all three contraction levels (ICC = 0.832-0.937 (BB); ICC = 0.814-0.957 (RF)). Normalized sEMG values showed no to high reliability (ICC = 0.030-0.831 (BB); ICC = 0.547-0.828 (RF)). sEMG signals recorded by the PSL-EMG-Tr1 showed good to excellent validity compared with the BTS-FREEEMG1000, at 40% MVIC (r = 0.943 (BB), r = 0.940 (RF)) and 80% MVIC (r = 0.983 (BB); r = 0.763 (RF)). CONCLUSIONS: The PSL-EMG-Tr1 was performed with acceptable validity. Furthermore, the high accessibility and portability of the device are useful in adjusting the type and intensity of exercise.

Highly Monodispersed PbS Quantum Dots for Outstanding Cascaded-Junction Solar Cells.

High-performance cascaded-junction quantum dot solar cells (CJQDSCs) are fabricated from as-prepared highly monodispersed lead sulfide QDs. The cells have a high power conversion of 9.05% and a short-circuit current density of 32.51 mA cm-2. A reliable and effective stratagem for fabricating high-quality lead sulfide quantum dots (QD) is explored through a "monomer" concentration-controlled experiment. Robust QDSC performances with different band gaps are demonstrated from the as-proposed synthesis and processing stratagems. Various potential CJQDSCs can be envisioned from the band edge evolution of the QDs as a function of size and ligands reported here.

¹8F-FDG PET/CT and Colorectal Cancer: Value of Fourth and Subsequent Posttherapy Follow-up Scans for Patient Management.

UNLABELLED: The purpose of this study was to evaluate the added value of a fourth and subsequent follow-up PET/CT scans to clinical assessment and impact on patient management in patients with colorectal cancer. METHODS: This was an institutional review board-approved, retrospective study. Eight hundred twenty-two patients with biopsy-proven colorectal cancer, who underwent (18)F-FDG PET/CT, were identified from 2000 to 2012. Among these, 73 (8.9%) patients underwent 4 or more follow-up PET/CT scans, with a total of 313 fourth and subsequent follow-up PET/CT scans. Median follow-up from the fourth follow-up PET/CT scan was 41.7 mo. The added value of each follow-up PET/CT scan, for clinical assessment and the treatment changes subsequent to each follow-up PET/CT scan, was established. Overall survival prediction was established using Kaplan-Meier plots with a Mantel-Cox log-rank test. RESULTS: Of the 313 fourth and subsequent follow-up PET/CT scans, 174 (55.6%) were interpreted as positive and 139 (44.4%) were interpreted as negative for recurrence or metastases. Thirty-four (46.6%) patients died during the study period. PET/CT identified recurrence or metastasis in 40.0% of scans obtained without prior clinical suspicion and ruled out disease in 23.6% of scans obtained with prior clinical suspicion. The PET/CT scan resulted in treatment change after 34.2% (107/313) of the scans. New treatment was initiated after 24.0% (75/313) of the scans, and treatment was changed after 8.0% (25/313) scans. There was a statistically significant difference in the overall survival between patients with a positive and all negative fourth and subsequent follow-up PET/CT scans at the patient level (log-rank, P = 0.001). CONCLUSION: The fourth and subsequent (18)F-FDG PET/CT scans obtained after primary treatment completion add value to clinical assessment and the management plan and provide prognostic information in patients with colorectal cancer.

Carbon monoxide poisoning-induced cardiomyopathy from charcoal at a barbecue restaurant: a case report.

OBJECTIVE: Acute carbon monoxide poisoning has important clinical value because it can cause severe adverse cardiovascular effects and sudden death. Acute carbon monoxide poisoning due to charcoal is well reported worldwide, and increased use of charcoal in the restaurant industry raises concern for an increase in occupational health problems. We present a case of carbon monoxide poisoning induced cardiomyopathy in a 47-year-old restaurant worker. MATERIALS AND METHODS: A male patient was brought to the emergency department to syncope and complained of left chest pain. Cardiac angiography and electrocardiography were performed to rule out acute ischemic heart disease, and cardiac markers were checked. After relief of the symptoms and stabilization of the cardiac markers, the patient was discharged without any complications. RESULTS: Electrocardiography was normal, but cardiac angiography showed up to a 40% midsegmental stenosis of the right coronary artery with thrombotic plaque. The level of cardiac markers was elevated at least 5 to 10 times higher than the normal value, and the carboxyhemoglobin concentration was 35% measured at one hour after syncope. Following the diagnosis of acute carbon monoxide poisoning induced cardiomyopathy, the patient's medical history and work exposure history were examined. He was found to have been exposed to burning charcoal constantly during his work hours. CONCLUSIONS: Severe exposure to carbon monoxide was evident in the patient because of high carboxyhemoglobin concentration and highly elevated cardiac enzymes. We concluded that this exposure led to subsequent cardiac injury. He was diagnosed with acute carbon monoxide poisoning-induced cardiomyopathy due to an unsafe working environment. According to the results, the risk of exposure to noxious chemicals such as carbon monoxide by workers in the food service industry is potentially high, and workers in this sector should be educated and monitored by the occupational health service to prevent adverse effects.

Intradermal nodular fasciitis of the face.

Nodular fasciitis represents reactive myofibroblastic proliferative lesions in the subcutaneous tissue, skeletal muscles, and fascia. Uncommon clinical and pathological variants of nodular fasciitis, such as intravascular, cranial, ossifying, and proliferative fasciitis, have been described. Six cases documenting a dermal location of nodular fasciitis have been reported in the English literature. Some authors have described that the histopathological features of intradermal nodular fasciitis are virtually identical to those of postoperative/posttraumatic spindle cell nodule of the skin. We herein report a 41-year-old Korean woman presenting with a 0.5 cm facial papule in which nodular fasciitis occurred in the dermis.

Comparison of image quality of shoulder CT arthrography conducted using 120 kVp and 140 kVp protocols.

OBJECTIVE: To compare the image quality of shoulder CT arthrography performed using 120 kVp and 140 kVp protocols. MATERIALS AND METHODS: Fifty-four CT examinations were prospectively included. CT scans were performed on each patient at 120 kVp and 140 kVp; other scanning parameters were kept constant. Image qualities were qualitatively and quantitatively compared with respect to noise, contrast, and diagnostic acceptability. Diagnostic acceptabilities were graded using a one to five scale as follows: 1, suboptimal; 2, below average; 3, acceptable; 4, above average; and 5, superior. Radiation doses were also compared. RESULTS: Contrast was better at 120 kVp, but noise was greater. No significant differences were observed between the 120 kVp and 140 kVp protocols in terms of diagnostic acceptability, signal-to-noise ratio, or contrast-to-noise ratio. Lowering tube voltage from 140 kVp to 120 kVp reduced the radiation dose by 33%. CONCLUSION: The use of 120 kVp during shoulder CT arthrography reduces radiation dose versus 140 kVp without significant loss of image quality.

Spinal cord glioblastoma induced by radiation therapy of nasopharyngeal rhabdomyosarcoma with MRI findings: case report.

Radiation-induced spinal cord gliomas are extremely rare. Since the first case was reported in 1980, only six additional cases have been reported.; The radiation-induced gliomas were related to the treatment of Hodgkin's lymphoma, thyroid cancer, and medullomyoblastoma, and to multiple chest fluoroscopic examinations in pulmonary tuberculosis patient. We report a case of radiation-induced spinal cord glioblastoma developed in a 17-year-old girl after a 13-year latency period following radiotherapy for nasopharyngeal rhabdomyosarcoma. MRI findings of our case are described.

Ultrasound and fluoroscopy-guided placement of central venous ports via internal jugular vein: retrospective analysis of 1254 port implantations at a single center.

OBJECTIVE: To assess the technical success and complication rates of the radiologic placement of central venous ports via the internal jugular vein. MATERIALS AND METHODS: We retrospectively reviewed 1254 central venous ports implanted at our institution between August 2002 and October 2009. All procedures were guided by using ultrasound and fluoroscopy. Catheter maintenance days, technical success rates, peri-procedural, as well as early and late complication rates were evaluated based on the interventional radiologic reports and patient medical records. RESULTS: A total of 433386 catheter maintenance days (mean, 350 days; range 0-1165 days) were recorded. The technical success rate was 99.9% and a total of 61 complications occurred (5%), resulting in a post-procedural complication rate of 0.129 of 1000 catheter days. Among them, peri-procedural complications within 24 hours occurred in five patients (0.4%). There were 56 post-procedural complications including 24 (1.9%, 0.055 of 1000 catheter days) early and 32 (2.6%, 0.074 of 1000 catheter days) late complications including, infection (0.6%, 0.018 of 10000 catheter days), thrombotic malfunction (1.4%, 0.040 of 1000 catheter days), nonthrombotic malfunction (0.9%, 0.025 of 1000 catheter days), venous thrombosis (0.5%, 0.014 of 1000 catheter days), as well as wound problems (1.1%, 0.032 of 1000 catheter days). Thirty six CVPs (3%) were removed due to complications. Bloodstream infections and venous thrombosis were the two main adverse events prolonging hospitalization (mean 13 days and 5 days, respectively). CONCLUSION: Radiologic placement of a central venous port via the internal jugular vein is safe and efficient as evidenced by its high technical success rate and a very low complication rate.

Histogram analysis of apparent diffusion coefficient map of standard and high B-value diffusion MR imaging in head and neck squamous cell carcinoma: a correlation study with histological grade.

RATIONALE AND OBJECTIVES: A histologic grade in head and neck squamous cell carcinoma (HNSCC) is clinically important because of its association with prognosis. The purpose of this study was to investigate the efficacy of histographic analysis of apparent diffusion coefficient (ADC) maps on the basis of the entire tumor volume in differentiating histologic grades in HNSCC at standard (b = 1000 s/mm(2)) and high (b = 2000 s/mm(2)) b values. MATERIALS AND METHODS: Fifty-four patients with HNSCC, including well-differentiated (WD; n = 35), moderately differentiated (MD; n = 13) and poorly differentiated (PD; n = 6) carcinomas, were retrospectively evaluated. ADC maps were obtained at two different b values (1000 and 2000 s/mm(2)) in each patient. Tumors were delineated on each slice of ADC maps, and data were collected to obtain a histogram for the entire tumor volume. Histographic parameters were calculated, including mean, standard deviation, kurtosis, skewness, and the ratio of the kurtosis measured at b values of 1000 and 2000 s/mm(2). These parameters were correlated with histologic grades. RESULTS: There was no significant correlation between tumor grades and histographic parameters obtained from ADC maps at b = 1000 s/mm(2). However, mean ADC at b = 2000 s/mm(2) was significantly higher in WD HNSCC (881 ± 131 × 10(-6) mm(2)/s) than in MD and PD HNSCC (770 ± 163 and 780 ± 158 × 10(-6) mm(2)/s, respectively) (P < .05). Kurtosis ratio was significantly higher in PD HNSCC (115 ± 10%) compared to WD and MD HNSCC (91 ± 21% and 86 ± 26%, respectively) (P < .05). Diagnostic accuracy was 100%, 76.9%, and 65.8% for PD, MD, and WD HNSCC, respectively. CONCLUSIONS: Histographic analysis of ADC maps on the basis of the entire tumor volume can be useful in differentiating histologic grades of HNSCC using mean ADC at b = 2000 s/mm(2) and kurtosis ratio.

Whitening effect of adipose-derived stem cells: a critical role of TGF-beta 1.

It has been demonstrated that adipose-derived stem cells (ADSCs) secrete cytokines and exhibit diverse pharmacological actions. The present study examined the unknown pharmacological action of ADSCs regarding whitening effects. A conditioned medium of ADSCs (ADSC-CM) was harvested and the whitening effect of ADSC-CM was studied in melanoma B16 cells. ADSC-CM treatment inhibited the synthesis of melanin and the activity of tyrosinase in a dose dependent manner. To clarify the underlying mechanisms of the whitening action of ADSCs, protein levels of melanogenic proteins were measured by Western blot. Although expressions of microphthalmia-associated transcription factor and tyrosinase-related protein 2 (TRP2) remained unchanged, those of tyrosinase and TRP1 were down-regulated. Transforming growth factor-beta1 (TGF-beta 1), a potent regulator of melanogenic proteins, was neutralized by the addition of a blocking antibody to ADSC-CM, and down-regulated expression of tyrosinase and TRP1 was almost reversed. Collectively, these results indicate that secretary factors of ADSC inhibit melanin synthesis by down-regulating the expression of tyrosinase and TRP1, which are mainly mediated by TGF-beta1.