A PET/CT volumetric parameter predicts prognosis of non-small cell lung cancer treated using preoperative chemoradiotherapy and surgery: A retrospective case series study.

The purpose of the present study was to clarify whether positron emission tomography/computed tomography (PET/CT) volumetric parameters were prognostic predictors of non-small cell lung cancer (NSCLC) treatment in patients who had undergone preoperative concurrent chemoradiotherapy (CCRT) and surgery. In the present study, retrospectively surveyed the data of patients with NSCLC who underwent preoperative CCRT and surgery at Okayama University Hospital (Okayama, Japan) between April 2006 and March 2018. The maximum standardized uptake value (SUVmax) and volumetric parameters, including metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were calculated using PET/CT and the percentage decrease (Δ) in each parameter value post-CCRT. The SUVmax threshold for defining MTV was set at 2.5. Furthermore, the association between survival and PET parameter values was analyzed. A total of 52 patients were included in the present study. The median follow-up period was 50.65 months. In univariate analysis, ΔTLG was identified to be a significant predictor of progression-free survival (PFS; P=0.03). The 5-year PFS rates were 48.6 and 76.6% for patients with low ΔTLG and high ΔTLG, respectively. High ΔTLG was indicative of a higher overall survival rate (P=0.08). The present results suggest that ΔTLG calculated using PET/CT is a prognostic predictor of NSCLC treated using preoperative CCRT and surgery, and may help physicians determine treatment strategies.

Volumetric PET Parameters Predict Prognosis after Definitive Chemoradiotherapy with Cisplatin/Docetaxel for Stage III Non-Small Cell Lung Cancer.

The aim of this study was to investigate whether volumetric positron emission tomography (PET) parameters are prognostic predictors in stage III non-small cell lung cancer patients receiving definitive concurrent chemo-radiotherapy (CCRT) with cisplatin/docetaxel. Cases involving definitive CCRT were reviewed retrospectively, and the maximum standardized uptake value, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were calculated. The relationships between these PET parameters and prognosis were analyzed. MTV and TLG were significant predictors of distant metastasis-free survival (DMFS) (p = 0.0003 and 0.0005, respectively) and progression-free survival (PFS) (p = 0.001 and 0.0007, respectively). The three-year DMFS rates in patients with low and high MTV were 13.3% and 64.6%, respectively, and the corresponding values in those with low and high TLG were 13.3% and 65.2%, respectively. The three-year PFS rates in patients with low and high MTV were 13.3% and 57.8%, respectively, and the corresponding values in patients with low and high TLG were 13.3% and 57.8%, respectively. However, MTV and TLG were not predictors of local control or overall sur-vival. We demonstrated that volumetric PET parameters were predictors of patients receiving definitive CCRT. Our findings contradict the findings of previous reports and warrant further research to validate them.

Bone microarchitectural analysis using ultra-high-resolution CT in tiger vertebra and human tibia.

BACKGROUND: To reveal trends in bone microarchitectural parameters with increasing spatial resolution on ultra-high-resolution computed tomography (UHRCT) in vivo and to compare its performance with that of conventional-resolution CT (CRCT) and micro-CT ex vivo. METHODS: We retrospectively assessed 5 tiger vertebrae ex vivo and 16 human tibiae in vivo. Seven-pattern and four-pattern resolution imaging were performed on tiger vertebra using CRCT, UHRCT, and micro-CT, and on human tibiae using UHRCT. We measured six microarchitectural parameters: volumetric bone mineral density (vBMD), trabecular bone volume fraction (bone volume/total volume, BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), and connectivity density (ConnD). Comparisons between different imaging resolutions were performed using Tukey or Dunnett T3 test. RESULTS: The vBMD, BV/TV, Tb.N, and ConnD parameters showed an increasing trend, while Tb.Sp showed a decreasing trend both ex vivo and in vivo. Ex vivo, UHRCT at the two highest resolutions (1024- and 2048-matrix imaging with 0.25-mm slice thickness) and CRCT showed significant differences (p ≤ 0.047) in vBMD (51.4 mg/cm3 and 63.5 mg/cm3 versus 20.8 mg/cm3), BV/TV (26.5% and 29.5% versus 13.8 %), Tb.N (1.3 l/mm and 1.48 l/mm versus 0.47 l/mm), and ConnD (0.52 l/mm3 and 0.74 l/mm3 versus 0.02 l/mm3, respectively). In vivo, the 512- and 1024-matrix imaging with 0.25-mm slice thickness showed significant differences in Tb.N (0.38 l/mm versus 0.67 l/mm, respectively) and ConnD (0.06 l/mm3 versus 0.22 l/mm3, respectively). CONCLUSIONS: We observed characteristic trends in microarchitectural parameters and demonstrated the potential utility of applying UHRCT for microarchitectural analysis.

A rapid caliber change in the inferior vena cava during multiphasic contrast-enhanced computed tomography may signal an acute anaphylactic reaction to nonionic contrast medium.

Severe anaphylactic reactions to an intravenous nonionic iodine contrast medium (NICM) are uncommon but can result in permanent morbidity or death if not managed appropriately. An anaphylactic reaction to an NICM typically manifests as clinical symptoms that include an itchy nose, sneezing, and skin redness. To our knowledge, a rapid change in the caliber of the inferior vena cava (IVC) during multiphasic contrast-enhanced computed tomography (CT) has not been reported. Here, we report the computed tomographic findings in three cases of hypovolemic shock caused by an anaphylactic reaction to an NICM. We suspect that a decrease in caliber of the IVC during multiphasic contrast-enhanced CT may be a predictor of an allergic-like reaction to an NICM. Patients in whom physicians and radiographers detect a rapid caliber change in the IVC during multiphasic contrast-enhanced CT should be managed carefully.

Utility of second-generation single-energy metal artifact reduction in helical lung computed tomography for patients with pulmonary arteriovenous malformation after coil embolization.

PURPOSE: The quality of images acquired using single-energy metal artifact reduction (SEMAR) on helical lung computed tomography (CT) in patients with pulmonary arteriovenous malformation (PAVM) after coil embolization was retrospectively evaluated. MATERIALS AND METHODS: CT images were reconstructed with and without SEMAR. Twenty-seven lesions [20 patients (2 males, 18 females), mean age 61.2 ± 11.0 years; number of embolization coils, 9.8 ± 5.0] on contrast-enhanced CT and 18 lesions of non-enhanced lung CT concurrently performed were evaluated. Regions of interest were positioned around the coils and mean standard deviation value was compared as noise index. Two radiologists visually evaluated metallic coil artifacts using a four-point scale: 4 = minimal; 3 = mild; 2 = strong; 1 = extensive. RESULTS: Noise index was significantly improved with SEMAR versus without SEMAR (median [interquartile range]; 194.4 [161.6-211.9] Hounsfield units [HU] vs. 243.9 [220.4-286.0] HU; p < 0.001). Visual score was significantly improved with SEMAR versus without SEMAR (Reader 1, 3 [3] vs.1 [1]; Reader 2, 3 [3] vs.1 [1]; p < 0.001). Significant differences were similarly demonstrated on lung CT (p < 0.001). CONCLUSION: SEMAR provided clear chest CT images in patients who underwent PAVM coil embolization.

Evaluating Low-kV Dual-source CT Angiography by High-pitch Spiral Acquisition and Iterative Reconstruction in Pediatric Congenital Heart Disease Patients.

We retrospectively evaluated the qualities of pediatric cardiovascular dual-source computed tomography (DSCT) images reconstructed by sinogram-affirmed iterative reconstruction (SAFIRE) and filtered back projection (FBP). We analyzed the cases of 287 congenital heart disease (CHD) patients < 5 years old, referred to our department in August 2013-March 2015. We divided them into two groups according to tube voltage (70 kVp, n=147; 80 kVp, n=140). All images were acquired by a CARE kV system and reconstructed by FBP and SAFIRE. The attenuation, noise, and signal-to-noise ratio (SNR) at each region of the heart and great vessels were measured. The volume CT dose index and dose-length product values were recorded. Compared to FBP, reconstruction by SAFIRE showed that the attenuation volume was significantly lower by 0.4% except for the ascending aorta (p<0.05), the noise value was lower by about 20% (p<0.05), and the SNR was higher by approx. 25% (p<0.05). The radiation dose in the 70 kVp group was significantly lower than that in the 80 kVp group. No significant differences in SNR were observed between the patient groups. DSCT image acquisition with SAFIRE using the CARE kV system results in low image noise and radiation dose in pediatric patients with CHD.

Image Quality of Coronary Arteries on Non-electrocardiography-gated High-Pitch Dual-Source Computed Tomography in Children with Congenital Heart Disease.

This study aimed to evaluate image quality of coronary artery imaging on non-electrocardiography (ECG)-gated high-pitch dual-source computed tomography (DSCT) in children with congenital heart disease (CHD) and to assess factors affecting image quality. We retrospectively reviewed the records of 142 children with CHD who underwent non-ECG-gated high-pitch DSCT. The subjective image quality of the proximal coronary segments was graded using a five-point scale. A score <3 represented a non-diagnostic image. Age, body weight, and heart rate were compared between the two groups: patients with good diagnostic image quality in all four segments and patients with at least one segment with non-diagnostic image quality. Predictors of image quality were assessed by multivariate logistic regression, including age, body weight, and heart rate. Four-hundred-fifty-seven of the 568 segments (80.5%) had diagnostic image quality. Patients with non-diagnostic segments were significantly younger (21.6 ± 25.5 months), had lower body weight (7.82 ± 5.00 kg), and a faster heart rate (123 ± 23.7 beats/min) (each p < 0.05) than patients with diagnostic image quality in all four segments (30.6 ± 20.7 months, 10.3 ± 4.00 kg, and 113 ± 21.6 beats/min, respectively; each p < 0.05). The multivariate logistic regression revealed that body weight (odds ratio 1.228; p = 0.029) was a significant predictor of image quality. Non-ECG-gated high-pitch DSCT provided adequate image quality of the proximal coronary segments in children with CHD. Lower body weight was a factor that led to poorer image quality of the coronary arteries.

Imaging of the temporal bone in children using low-dose 320-row area detector computed tomography.

INTRODUCTION: The aim of this study was to compare the image quality obtained using low-dose and standard-dose 320-row temporal bone computed tomography (CT) in paediatric patients. METHODS: Thirteen low-dose CT (120 kV/50 mAs) and nine standard-dose CT (120 kV/100 mAs) images from children up to 5 years of age were compared for their image quality. The noise and signal-to-noise ratio for bone, fat and air were measured. Two observers assessed the overall image quality and ability to visualize 14 small anatomic structures using a 5-point scale, with a score of 3-5 indicating imaging of diagnostic quality. RESULTS: Noise was significantly higher and the signal-to-noise ratio was significantly lower with low-dose CT. Although the overall image quality and visibility of several structures on low-dose CT were significantly reduced when compared with standard-dose CT, all the image quality scores were 3 or >3. The dose-length products for low-dose CT and standard-dose CT were 59.6 mGy·cm and 119.3 mGy·cm, respectively. CONCLUSION: Low-dose CT of the temporal bone using 320-row CT provides images of diagnostic quality for assessment of middle and inner ear anatomy, similar to that provided by the standard-dose protocol, in spite of increased image noise.

Thallium-201 Uptake of Giant Cell Tumor: One Step Toward the Differential Diagnosis to Atypically Presenting Osteosarcoma.

OBJECTIVE: The radiologic differential diagnosis of giant cell tumors (GCTs) is challenging because there is a risk of misdiagnosis of GCTs as malignant lesions such as atypically presenting osteosarcomas (OSs). This study aims to assess the feasibility of 201Tl scintigraphy for the differential diagnosis of GCT and atypical OS. MATERIALS AND METHODS: Thallium-201 scintigraphy scans obtained between January 2006 and October 2015 of patients with histologically proven GCT (23 patients [male-to-female ratio, 15:8]; median age, 33.0 years; age range, 20-61 years) and patients with atypically presenting OS (20 patients [male-to-female ratio, 11:9]; median age, 30.0 years; age range, 12-69 years) were retrospectively reviewed. Morphologic classification of osseous lesions was performed on radiographs and CT scans. The 201Tl scintigraphy-based tumor-to-background contrast (TBC) and washout rate (WR) were calculated on early phase and delayed phase scans. The laboratory parameters lactate dehydrogenase (LDH), C-reactive protein (CRP), and alkaline phosphatase were obtained. Statistical significance was estimated using the Mann-Whitney U test. Cutoff values were calculated for early phase TBC and delayed phase TBC. RESULTS: Twenty-two of 23 GCTs were detected on the initial radiographs, whereas only six of 20 atypical OSs were detected on the initial radiographs. The early phase TBC was increased in GCT (median, 2.59; range, 0.51-12.26) compared with atypical OS (median, 1.68; range, 0.90-6.45) (p = 0.07). The delayed phase TBC was increased in GCT (median, 1.65; range, 0.22-5.26) compared with atypical OS (median, 0.96; range, 0.39-3.76) (p = 0.02). The median WR was not significantly decreased in GCT. The cutoff value for the early phase TBC was 3.90, and the cutoff value for the delayed phase TBC was 1.64; these cutoff values for early and delayed phase TBC yielded a sensitivity of 80.0% and a specificity of 47.8% and 52.2% respectively. Serum LDH (mean: atypical OS vs GCT, 215.5 vs 170.5 U/L, respectively; p = 0.01), alkaline phosphatase (median: 355.0 vs 252.0 U/L; p = 0.03), and CRP (median: 0.21 vs 0.09 mg/dL; p = 0.04) values were significantly increased in atypical OS compared with GCT. CONCLUSION: The intense 201Tl uptake of GCT in combination with laboratory OS biomarkers facilitate the differential diagnosis of GCT and atypically presenting OS.

A Case of Focal Bone Marrow Reconversion Mimicking Bone Metastasis: The Value of 111Indium Chloride.

We present a case of a 66-year-old man with esophageal carcinoma. 18Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for evaluating distant metastasis and staging revealed 18F-FDG uptake in the third lumbar vertebra and other vertebrae. Magnetic resonance imaging could not differentiate bone metastases from benign bone lesions. We considered the possibility of bone marrow reconversion. 111Indium chloride (111In-Cl3) scintigraphy with single-photon emission computed tomography/computed tomography (SPECT/CT) revealed erythroid bone marrow components in the bone lesions. The diagnosis of bone marrow reconversion was pathologically confirmed by a bone biopsy of the third lumbar vertebra. The patient underwent esophagectomy and has remained disease-free in the 2 years since. To the best of our knowledge, this is the first report to describe the usefulness of 111In-Cl3 with SPECT/CT for the diagnosis of bone marrow reconversion.

Image Quality of Coronary Computed Tomography Angiography with 320-Row Area Detector Computed Tomography in Children with Congenital Heart Disease.

The objective of this study was to assess factors affecting image quality of 320-row computed tomography angiography (CTA) of coronary arteries in children with congenital heart disease (CHD). We retrospectively reviewed 28 children up to 3 years of age with CHD who underwent prospective electrocardiography (ECG)-gated 320-row CTA with iterative reconstruction. We assessed image quality of proximal coronary artery segments using a five-point scale. Age, body weight, average heart rate, and heart rate variability were recorded and compared between two groups: patients with good diagnostic image quality in all four coronary artery segments and patients with at least one coronary artery segment with nondiagnostic image quality. Altogether, 96 of 112 segments (85.7 %) had diagnostic-quality images. Patients with nondiagnostic segments were significantly younger (10.0 ± 11.6 months) and had lower body weight (5.9 ± 2.9 kg) (each p < 0.05) than patients with diagnostic image quality of all four segments (20.6 ± 13.8 months and 8.4 ± 2.5 kg, respectively; each p < 0.05). Differences in heart rate and heart rate variability between the two imaging groups were not significant. Receiver operating characteristic analyses for predicting patients with nondiagnostic image quality revealed an optimal body weight cutoff of ≤5.6 kg and an optimal age cutoff of ≤12.5 months. Prospective ECG-gated 320-row CTA with iterative reconstruction provided feasible image quality of coronary arteries in children with CHD. Younger age and lower body weight were factors that led to poorer image quality of coronary arteries.

Diagnostic value of Thallium-201 scintigraphy in differentiating malignant bone tumors from benign bone lesions.

OBJECTIVE: This retrospective study aims to evaluate the diagnostic capacity of thallium-201 (201Tl) scintigraphy for differentiating malignant bone tumors from benign bone lesions. METHODS: Between January 2006 and December 2012, 279 patients with bone lesions (51 malignant and 228 benign) underwent 201Tl scintigraphy before treatment. To evaluate 201Tl uptake, we investigated tumor-to-background contrast (TBC) as well as TBC washout rate (WR). The differences of TBC on early and delayed images and WR were estimated by the Mann-Whitney U test. Receiver operating characteristic (ROC) analyses were used to determine the cut-off TBC values for differentiating malignant bone tumors from benign bone lesions. RESULTS: There were statistically significant differences in median TBC between malignant tumors and benign lesions. These differences occurred for early imaging (1.57 vs. 0.09, p < 0.001) as well as for delayed imaging (0.83 vs. 0.07, p < 0.001). However, there was no statistical difference in WR between malignant tumors and benign lesions (44 vs. 43 %, NS). The chosen TBC cut-off value was 0.68 for early imaging and 0.38 for delayed imaging. Using these cut-off values, the prediction of malignancy had a 77 % sensitivity, 74 % specificity, and 75 % accuracy for early imaging and an 80 % sensitivity, 76 % specificity, and 77 % accuracy for delayed imaging. CONCLUSIONS: 201Tl scintigraphy may have the ability to distinguish malignant bone tumors from benign bone lesions.

Phrenic nerve injury after radiofrequency ablation of lung tumors: retrospective evaluation of the incidence and risk factors.

PURPOSE: To retrospectively investigate the incidence of and risk factors for phrenic nerve injury after radiofrequency (RF) ablation of lung tumors. MATERIALS AND METHODS: The study included 814 RF ablation procedures of lung tumors. To evaluate the development of phrenic nerve injury, chest radiographs obtained before and after the procedure were examined. Phrenic nerve injury was assumed to have developed if the diaphragmatic level was elevated after the procedure. To identify risk factors for phrenic nerve injury, multiple variables were compared between cases of phrenic nerve injury and randomly selected controls by using univariate analyses. Multivariate analysis was then performed to identify independent risk factors. RESULTS: Evaluation of phrenic nerve injury from chest radiographs was possible after 786 procedures. Evidence of phrenic nerve injury developed after 10 cases (1.3%). Univariate analysis revealed that larger tumor size (≥ 20 mm; P = .014), proximity of the phrenic nerve to the tumor (< 10 mm; P < .001), the use of larger electrodes (array diameter or noninsulated tip length ≥ 3 cm; P = .001), and higher maximum power applied during ablation (≥ 100 W; P < .001) were significantly associated with the development of phrenic nerve injury. Multivariate analysis demonstrated that the proximity of the phrenic nerve to the tumor (< 10 mm; P < .001) was a significant independent risk factor. CONCLUSIONS: The incidence of phrenic nerve injury after RF ablation was 1.3%. The proximity of the phrenic nerve to the tumor was an independent risk factor for phrenic nerve injury.

Influence of radiofrequency ablation of lung cancer on pulmonary function.

PURPOSE: The purpose of this study was to evaluate altered pulmonary function retrospectively after RFA. METHODS: This retrospective study comprised 41 ablation sessions for 39 patients (22 men and 17 women; mean age, 64.8 years). Vital capacity (VC) and forced expiratory volume in 1 s (FEV(1)) at 1 and 3 months after RFA were compared with the baseline (i.e., values before RFA). To evaluate the factors that influenced impaired pulmonary function, univariate analysis was performed by using multiple variables. If two or more variables were indicated as statistically significant by univariate analysis, these variables were subjected to multivariate analysis to identify independent factors. RESULTS: The mean VC and FEV(1) before RFA and 1 and 3 months after RFA were 3.04 and 2.24 l, 2.79 and 2.11 l, and 2.85 and 2.13 l, respectively. The values at 1 and 3 months were significantly lower than the baseline. Severe pleuritis after RFA was identified as the independent factor influencing impaired VC at 1 month (P = 0.003). For impaired FEV(1) at 1 month, only severe pleuritis (P = 0.01) was statistically significant by univariate analysis. At 3 months, severe pleuritis (VC, P = 0.019; FEV(1), P = 0.003) and an ablated parenchymal volume ≥20 cm(3) (VC, P = 0.047; FEV(1), P = 0.038) were independent factors for impaired VC and FEV(1). CONCLUSIONS: Pulmonary function decreased after RFA. RFA-induced severe pleuritis and ablation of a large volume of marginal parenchyma were associated with impaired pulmonary function.

Relevance of the directionality of skin elasticity to aging and sagging of the face.

BACKGROUND: Forces acting in facial skin have been suggested to show directionality. Non-invasive methods of measuring this directionality may thus provide information related to aging processes. The Reviscometer(®) RVM600 device is capable of measuring directionality of forces on the skin. This device has not been used previously in a published study to evaluate changes in directionality of forces on facial skin with aging. AIM: The first objective of this pilot study was to investigate relationships between mechanical directionality using the Reviscometer(®) RVM600, the Cutometer(®) MPA580, and aging of the facial skin in a supine position. In addition, the study investigated relationships between mechanical directionality and 'skin sagging,' which may be caused by gravity. To validate this as a new measurement of mechanical directionality, we also performed double-blinded trials on two groups of subjects, with one group using a product containing an anti-aging substance and the other group using a placebo product without an anti-aging substance. METHODS: We examined 91 healthy Japanese women with a mean age of 48.5 years (range, 20-79 years) at the three sites on the face using the Reviscometer(®) RVM600 and the Cutometer(®) MPA580, and evaluation was performed for skin sagging in September and November 2008, and January 2009. The Reviscometer(®) RVM600 was used to measure resonance-running time (RRT) every 10° from 0° to 350°. Evaluation of skin sagging was undertaken by making marks on the face and using face photographs taken in both sitting and supine positions to calculate the sagging index. Usage testing was conducted on 38 healthy Japanese women in a double-blinded study with one group, using a preparation containing Yomogi AGEs Clearing (YAC) extract and another group using the same preparation without the YAC extract from October 2008 to April 2009. Mean age of these subjects was 44.0 years (range, 30-60 years). Measurements were taken at the three sites on the face using the Reviscometer(®) RVM600 and the Cutometer(®) MPA580 and sagging index. RESULTS: A significant correlation was identified between RRT parameters and subject age at all three measurement sites. Significant correlations between sagging index and RRT values were found for 110-170° and 290-350° only at the center of the cheek. Significant differences in RRT values were noted for 110-150° and 300-350° at this site between subjects with and without the use of YAC extract. A similar trend was found in sagging index for this site alone between subjects with and without YAC extract. CONCLUSION: The use of non-invasive procedures to measure skin mechanical parameters on the face in all directions may evaluate aging and effective preventive and restorative support.

Melanin and facial skin fluorescence as markers of yellowish discoloration with aging.

BACKGROUND: Although one clinical sign of aging and/or photoaging is a yellowish discoloration of the facial skin, little is known about the cause of this change. In addition to the increase in the epidermal melanin content, it has been suggested that advanced glycation end products (AGEs), which are known to accumulate in photoaged skin, may affect this discoloration. AIM: The objective of this pilot study was to non-invasively investigate the roles of melanin and AGEs in this yellowish discoloration of the facial skin. METHODS: We examined the spectral reflectance at the cheek in 40 healthy Japanese women of various ages (mean age, 38.1 years) using a reflectance spectrophotometer and a spectrofluorimeter. The degree of yellowish tint was evaluated in terms of b(*). The amount of melanin in the skin was evaluated by calculating the melanin index (MI) A(640)-A(670) [A(lambda): log(10) (1/reflectance) at a wavelength of lambda]. The amount of AGEs was roughly evaluated using the AGEs index, which is thought to linearly correlate with the amount of intrinsic fluorescence markers irrespective of the concentration of melanin and is defined as follows: AGEs index=I(5)/SQR (I(1)xI(2)). In this equation, the intensities of reflectance are I(1) at an excitation wavelength of 335 nm, I(2) at an emission wavelength of 390 nm and I(5) at 390 nm under an excitation wavelength of 335 nm. RESULTS: Both b(*) and the AGEs index were significantly correlated with subject age (r=0.34, P<0.05 and r=0.68, P<0.0001, respectively). Significant correlations were also observed between MI and b(*) (r=0.63, P<0.0001) and between the AGEs index and b(*) (r=0.53, P<0.0005). However, no significant correlations were seen between MI and the AGEs index. CONCLUSION: The AGEs index does not appear to be influenced by the amount of melanin and may be utilized as an indicator of the amount of AGEs in the skin. AGEs are likely to play a role in the yellowish discoloration of skin with aging.

Abscess formation of the round ligament of the liver: report of a case.

Abscess formation of the round ligament of the liver is very rare. We report a case of a 70-year-old female with abscess of the round ligament after an endoscopic papillotomy for choledocholithiasis. On the 21st day following papillotomy, abscess formation of the round ligament was found by ultrasonographic examination. Surgical treatment was performed because conservative therapy was not effective. The purulent fluid and necrotic tissue at the round ligament were completely removed. Cultures obtained from the abscess grew Staphylococcus epidermidis, but the mechanism of abscess formation in this case remains unclear.

A novel agent, methylophiopogonanone B, promotes Rho activation and tubulin depolymerization.

Cytoskeletal reorganization, including reconstruction of actin fibers and microtubules, is essential for various biological processes, such as cell migration, proliferation and dendrite formation. We show here that methylophiopogonanone B (MOPB) induces cell morphological change via melanocyte dendrite retraction and stress fiber formation. Since members of the Rho family of small GTP-binding proteins act as master regulators of dendrite formation and actin cytoskeletal reorganization, and activated Rho promotes dendrite retraction and stress fiber formation, we studied the effects of MOPB on the small GTPases using normal human epidermal melanocytes and HeLa cells. In in vitro binding assay, MOPB significantly increased GTP-Rho, but not GTP-Rac or GTP-CDC42. Furthermore, a Rho inhibitor, a Rho kinase inhibitor and a small GTPase inhibitor each blocked MOPB-induced stress fiber formation. The effect of MOPB on actin reorganization was blocked in a Rho dominant negative mutant. These results suggest MOPB acts via the Rho signaling pathway, and it may directly or indirectly activate Rho. Quantitative Western blot analysis indicated that MOPB also induced microtubule destabilization and tubulin depolymerization. Thus, MOPB appears to induce Rho activation, resulting in actin cytoskeletal reorganization, including dendrite retraction and stress fiber formation.

Centaureidin promotes dendrite retraction of melanocytes by activating Rho.

Melanosomes synthesized within melanocytes are transferred to keratinocytes through dendrites, resulting in a constant supply of melanin to the epidermis, and this process determines skin pigmentation. During screening for inhibitors of melanosome transfer, we found a novel reagent, centaureidin, that induces significant morphological changes in normal human epidermal melanocytes and inhibits melanocyte dendrite elongation, resulting in a reduction of melanosome transfer in an in vitro melanocyte-keratinocyte co-culture system. Since members of the Rho family of small GTP-binding proteins act as master regulators of dendrite formation, and activated Rho promotes dendrite retraction, we studied the effects of centaureidin on the small GTPases. In in vitro binding assay, centaureidin activated Rho and furthermore, a Rho inhibitor (C. botulinum C3 exoenzyme), a Rho kinase inhibitor (Y27632) and a small GTPase inhibitor (Toxin B) blocked dendrite retraction induced by centaureidin. These results suggest centaureidin could act via the Rho signaling pathway, and it may directly or indirectly activate Rho. Thus, centaureidin appears to inhibit dendrite outgrowth from melanocytes by activating Rho, resulting in the inhibition of melanosome transfer from melanocytes to keratinocytes.

Mitogen- and ultraviolet-B-induced signaling pathways in normal human melanocytes.

In normal human melanocytes various mitogens activate the mitogen-activated protein kinases ERK1/2 and the downstream transcription factor CREB (Ca2+/cAMP response element binding protein). Endothelin-1, basic fibroblast growth factor, and alpha-melanotropin interact synergistically to stimulate human melanocyte proliferation. The former two mitogens phosphorylated ERK1/2, its substrate p90rsk, and CREB. Alpha-melanotropin, forskolin, or dibutyryl cAMP failed to phosphorylate any of those targets, however. The concomitant presence of endothelin-1, basic fibroblast growth factor, and alpha-melanotropin significantly potentiated CREB phosphorylation. The mitogen-induced phosphorylation of p90rsk and CREB was dependent on ERK1/2 activation, and was mediated by intracellular calcium mobilization and by protein kinase C and tyrosine kinase activation, but not by activation of the cAMP-dependent protein kinase A. Exposure of melanocytes to ultraviolet radiation B resulted in the phosphorylation of the stress-induced mitogen- activated protein kinases p38 and JNK/SAPK, but not ERK1/2. Ultraviolet radiation B induced the phosphorylation of CREB via a pathway that was partially dependent on p38, but had no effect on p90rsk or ERK1/2. Therefore, in human melanocytes, CREB is a common downstream target for distinct effectors that are involved in either mitogenic signaling or stress signaling initiated by ultraviolet radiation B.