Use of transcriptomic profiling to identify candidate genes involved in Polyporus umbellatus sclerotial formation affected by oxalic acid.

Polyporus umbellatus is a precious medicinal fungus. Oxalic acid was observed to affect sclerotial formation and sclerotia possessed more medicinal compounds than mycelia. In this study, the transcriptome of P. umbellatus was analysed after the fungus was exposed to various concentrations of oxalic acid. The differentially expressed genes (DEGs) encoding a series of oxidases were upregulated, and reductases were downregulated, in the low-oxalic-acid (Low OA) group compared to the control (No OA) group, while the opposite phenomenon was observed in the high-oxalic-acid (High OA) group. The detection of reactive oxygen species (ROS) in P. umbellatus mycelia was performed visually, and Ca2+ and H2O2 fluxes were measured using non-invasive micro-test technology (NMT). The sclerotial biomass in the Low OA group increased by 66%, however, no sclerotia formed in the High OA group. The ROS fluorescence intensity increased significantly in the Low OA group but decreased considerably in the High OA group. Ca2+ and H2O2 influx significantly increased in the Low OA group, while H2O2 exhibited efflux in the High OA group. A higher level of oxidative stress formed in the Low OA group. Different concentrations of oxalic acid were determined to affect P. umbellatus sclerotial formation in different ways.

Quantitative Analysis Methods Using Histogram and Entropy for Detector Performance Evaluation According to the Sensitivity Change of the Automatic Exposure Control in Digital Radiography.

The purpose of this study is to evaluate detector performance using histogram and entropy analysis according to the sensitivity change of the automatic exposure control (AEC). The experiment was performed as follows: The sensitivity of the detector was analyzed through a normalized histogram with sensitivities of S200, S400, S800, and S1000 of the AEC; the entropy of the image was then analyzed, and the signal volume of the detector was evaluated according to the sensitivity change. As the sensitivity of the AEC was increased from S200 to S1000, the histogram showed underflow, quantization separation, and dynamic range discrepancy. In addition, entropy showed a decrease as sensitivity was set higher; in particular, entropy degradation was more prominent at sensitivities above S800. Through the histogram and entropy analysis, it was concluded that the detector does not reproduce the sensitivity and signal volume accurately when the sensitivity of the AEC is set high in performance evaluation.

Genetic Diversity and Dye-Decolorizing Spectrum of Schizophyllum commune Population.

Synthetic dyes are widely used in various industries and their wastage causes severe environmental problems while being hazardous to human health, leading to the need for eco-friendly degradation techniques. The split-gill fungus Schizophyllum commune, which is found worldwide, has the potential to degrade all components of the lignocellulosic biomass and is a candidate for the treatment of synthetic dyes. A systematic molecular analysis of 75 Korean and 6 foreign S. commune strains has revealed the high genetic diversity of this population and its important contribution to the total diversity of S. commune. We examined the dye decolorization ability of this population and revealed 5 excellent strains that strongly decolorized 3 dyes: Crystal Violet, Congo Red and Methylene Blue. Finally, comparison of dye decolorization ability and the phylogenetic identification of these strains generalized their genetic and physiological diversity. This study provides an initial resource for physiological and genetic research projects as well as the bioremediation of textile dyes.

In Vitro and In Vivo Medicinal Value of Culinary-Medicinal Lung Oyster Mushroom Pleurotus pulmonarius var. stechangii (Agaricomycetes).

Pleurotus pulmonarius var. stechangii is a culinary-medicinal mushroom commonly cultivated in subtropical countries in Asia. In this study, the in vitro antixanthine oxidase, antihyperglycemic, and in vivo anti-inflammatory activities of a methanol extract (ME) of P. pulmonarius var. stechangii fruiting bodies were evaluated. The xanthine oxidase inhibitory activity of the ME of P. pulmonarius var. stechangii was lower than that of allopurinol, a xanthine oxidase inhibitor used as a positive control. Eleven phenolic compounds were identified from the fruiting bodies of P. pulmonarius var. stechangii by HPLC analysis. The inhibitory effects of ME on α-amylase and α-glucosidase were moderate and lower than that of acarbose, a positive control. The ME inhibited the production of nitric oxide (NO) and nitric oxide synthases (iNOS) protein expression in lipopolysaccharide-induced RAW 264.7 macrophages. It also exhibited an inhibitory effect on carrageenan-induced hind paw edema in a rat model. Taken together, our experimental results demonstrated that the fruiting bodies of P. pulmonarius var. stechangii might be a good natural source to promote human health through its antixanthine oxidase, antihyperglycemia, and anti-inflammatory activities.

Antioxidant, Anti-Melanogenic and Anti-Wrinkle Effects of Phellinus vaninii.

In this study, the antioxidant, anti-xanthine oxidase, anti-melanogenic and anti-wrinkle effects of methanol (ME) and hot water (HE) extracts from the fruiting bodies of Phellinus vaninii were investigated. The 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging activity of 2.0 mg/mL HE (95.38%) was comparable to that of butylated hydroxytoluene (96.97%), the reference standard. The hydroxyl radical scavenging activities of ME (98.19%) and HE (97.55%) were higher than that of butylated hydroxytoluene (92.66%) at 2.0 mg/mL. Neither ME nor HE was cytotoxic to murine melanoma B16-F10 cells at 25-750 µg/mL. Although the xanthine oxidase (XO) inhibitory effects of ME and HE were significantly lower than that of allopurinol, the values were higher than 84 percent. The in vitro tyrosinase inhibitory activities of ME and HE were comparable to kojic acid at 2.0 mg/mL. The cellular tyrosinase and melanin synthetic activities of ME and HE on B16-F10 melanoma cells at 500 µg/mL were higher than arbutin, indicating that the inhibitory effects of arbutin on the tyrosinase and melanin synthesis were higher than those of ME and HE. The collagenase inhibitory activity of HE was comparable to EGCG at 2.0 mg/mL, however, the elastase inhibitory activity of ME and HE was lower than EGCG at the concentration tested. The study results demonstrated that the fruiting bodies of Ph. vaninii possessed good antioxidant, anti-xanthine oxidase, cell-free anti-tyrosinase, cellular anti-tyrosinase, anti-collagenase, and moderate anti-elastase activities, which might be used for the development of novel anti-gout, skin-whitening, and skin anti-wrinkle agents.

Hyperlipidemic Inhibitory Effects of Phellinus pini in Rats Fed with a High Fat and Cholesterol Diet.

This study evaluated the in vitro and in vivo hypolipidemic effects of the medicinal mushroom Phellinus pini. The methanol extract (ME) of the fruiting body of Ph. pini was active against pancreatic lipase and cholesterol esterase with 99.14% and 67.23% inhibited activity at 1.0 mg/mL, respectively. It also inhibited 81.81% and 55.33% of α-glucosidase and α-amylase activities, respectively, at 2.0 mg/mL. Hyperlipidemia as induced by feeding rats with a high fat and cholesterol diet (HFC). HFC supplemented with a 5% fruiting body powder of Ph. pini (HFC + PhP) significantly reduced plasma total cholesterol, low-density lipoprotein cholesterol, and triglycerides in rats compared with HFC. The reduced levels were comparable to rats fed the normal control diet (NC). The atherogenic index of HFC + PhP rats was significantly lower than that of the HFC rats. The excretion of fecal total lipid and cholesterol in the HFC + PhP rats was significantly higher than those in the NC and HFC rats. Histopathological examinations demonstrated scant deposition of lipids in the liver of rats fed HFC + PhP. The dietary supplementation with the fruiting body powder provided natural plasma lipid and glucose lowering effects in experimental rats without adverse effects on the plasma biochemical parameters and liver function related enzyme activities. Therefore, the hypolipidemic effects of Ph. pini may be due to the inhibitory effects on pancreatic lipase, cholesterol esterase, α-glucosidase, and α-amylase, and excretion of excess lipids and cholesterol in the feces.

Evaluation of Anticholinesterase and Inflammation Inhibitory Activity of Medicinal Mushroom Phellinus pini (Basidiomycetes) Fruiting Bodies.

Phellinus pini, a medicinal mushroom, has been used as folk medicine in Asian countries for treating ailments such as cancer and gastrointestinal diseases. In this study we evaluated in vitro the antidementia and anti-inflammatory activities of Ph. Pini fruiting bodies. Eleven phenol compounds were detected by high-performance liquid chromatography analysis. Acetylcholinesterase and butyrylcholinesterase inhibitory effects of a methanol extract and a hot water extract were moderate and comparable with those of galanthamine, the standard drug used to treat the early stages of Alzheimer's disease. The methanol extract had a neuroprotective effect against glutamate-induced cytotoxicity on PC-12 cells at concentration ranging from 20 to 40 µg/mL. The mushroom extracts also inhibited the production of nitric oxide and the expression of inducible nitric oxide synthase in lipopolysaccharide-induced RAW 264.7 macrophages, and they significantly inhibited in vivo carrageenan-induced hind-paw edema in rats. Therefore, it is suggested that Ph. Pini fruiting bodies possess anticholinesterase and anti-inflammatory effects.

Assessment of pupillary light reflex using a smartphone application.

In unconscious patients, pupillary light reflex is an indicator of brain damage. In the current study, a smartphone application was developed for the purpose of measuring pupillary light reflex with an aim to determine the agreement between pupillary light reflex measurements using a smartphone application (APP) and a penlight (PEN). The APP acquires five sequential photographs using the camera flash in order to stimulate the pupil. The initial image is captured prior to the flash, and the subsequent image is obtained while the flash is on. The remaining three images are captured whilst the flash is off. Pupillary right reflex was assessed in 30 healthy subjects using a PEN. After 10 min, the examiners inspected the images of light reflex acquired from the same subjects using the APP, and completed the corresponding questionnaire containing details of pupil size and degree of response. Agreement between the two assessment methods was determined by calculating bias, limits of agreement, and the intraclass correlation (ICC) coefficient. A statistically significant difference was not observed between the two methods regarding pupil size and degree of response. Bias was 0.1 mm and limits of agreement were ±1.5 mm, as compared with PEN. ICC was 0.93 (95% confidence interval, 0.89-0.96). Therefore, it may be concluded that the results of pupillary light reflex assessed by PEN and APP display no significant difference. Furthermore, the APP provides advantages such as portability, objectivity and the possibility of being used as objective medical evidence.

In Vitro Antioxidant, Anti-Diabetes, Anti-Dementia, and Inflammation Inhibitory Effect of Trametes pubescens Fruiting Body Extracts.

Trametes pubescens, white rot fungus, has been used for folk medicine in Asian countries to treat ailments such as cancer and gastrointestinal diseases. This study was initiated to evaluate the in vitro antioxidant, anti-diabetes, anti-dementia, and anti-inflammatory activities of T. pubescens fruiting bodies. The 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging activities of T. pubescens methanol (ME) and hot water (HWE) extracts (2.0 mg/mL) were comparable to butylated hydroxytoluene (BHT), the positive control. However, the chelating effects of ME and HWE were significantly higher than that of BHT. The HWE (6 mg/mL) also showed comparable reducing power to BHT. Eleven phenol compounds were detected by high performance liquid chromatography (HPLC) analysis. The α-amylase and α-glucosidase inhibitory activities of the ME and HWE of the mushroom were lower than Acarbose, the standard reference; however, the inhibitory effects of the mushroom extracts at 2.0 mg/mL were moderate. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory effects of ME and HWE were moderate and comparable with galanthamine, the standard drug to treat early stages of Alzheimer's disease (AD). The ME had a neuroprotective effect against glutamate-induced PC-12 cell cytotoxicity at the concentration range of 2-40 µg/mL. The mushroom extracts also showed inflammation inhibitory activities such as production of nitric oxide (NO) and expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-induced murine macrophage-like cell lines (RAW 264.7) and significantly suppressed the carrageenan-induced rat paw-edema. Therefore, fruiting body extracts of T. pubescens demonstrated antioxidant related anti-diabetes, anti-dementia and anti-inflammatory activities.

Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus.

Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously.

Evaluation of Antioxidant, Anti-cholinesterase, and Anti-inflammatory Effects of Culinary Mushroom Pleurotus pulmonarius.

Culinary mushroom Pleurotus pulmonarius has been popular in Asian countries. In this study, the anti-oxidant, cholinesterase, and inflammation inhibitory activities of methanol extract (ME) of fruiting bodies of P. pulmonarius were evaluted. The 1,1-diphenyl-2-picryl-hydrazy free radical scavenging activity of ME at 2.0 mg/mL was comparable to that of butylated hydroxytoluene, the standard reference. The ME exhibited significantly higher hydroxyl radical scavenging activity than butylated hydroxytoluene. ME showed slightly lower but moderate inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase than galantamine, a standard AChE inhibitor. It also exhibited protective effect against cytotoxicity to PC-12 cells induced by glutamate (10~100 µg/mL), inhibitory effect on nitric oxide (NO) production and inducible nitric oxide synthase protein expression in lipopolysaccharide-stimulated RAW 264.7 macrophages, and carrageenan-induced paw edema in a rat model. High-performance liquid chromatography analysis revealed the ME of P. pulmonarius contained at least 10 phenolic compounds and some of them were identified by the comparison with known standard phenolics. Taken together, our results demonstrate that fruiting bodies of P. pulmonarius possess antioxidant, anti-cholinesterase, and inflammation inhibitory activities.

Efficacy of postoperative mitomycin-C eye drops on the clinical outcome in endoscopic dacryocystorhinostomy.

PURPOSE: To evaluate the effect of postoperative topical mitomycin-C (MMC) eye drops in endoscopic (dacryocystorhinostomy) DCR and compare them with intraoperative MMC soaking. DESIGN: Retrospective, nonrandomized, interventional case series. METHODS: One hundred and sixty cases of endoscopic DCR with a single surgeon for primary nasolacrimal duct obstruction (NLDO) were included. Cases were divided into three groups. Group 1 was treated with intraoperative application of 0.02 % MMC for 5 min. Group 2 was treated with 0.02 % MMC eye drops for 5 days after surgery, without intraoperative application of MMC. Group 3 was the control group of cases without the use of MMC. Each group was evaluated for surgical success, presence of complications including granuloma, synechiae, and tube-induced inflammation, and the adverse effect of the MMC at least 6 months after the surgery. RESULTS: The success rate showed no significant difference among the three groups (P = .122, chi-square analysis). In the analysis between the two groups, although the success rate of Group 2 appeared not to be statistically different compared with that of Group 1 (P = .419, chi-square analysis), Group 2 had a statistically higher success rate for surgery than Group 3 (P = .041, chi-square analysis). The presence of granuloma was significantly lower in Group 1 than in the other two groups (P = .022, chi-square analysis). Synechiae and silicone tube-induced inflammation were not significantly different (P = .308, P = .881, chi-square analysis). There were no adverse effects associated with intraoperative or postoperative MMC application. CONCLUSION: Use of postoperative topical 0.02 % MMC is a safe and effective adjunctive modality to increase the success rate of endoscopic DCR.

Endoluminal Closure of Colon Perforation with Endoscopic Band Ligation: Technical Feasibility and Safety in an In Vivo Canine Model.

BACKGROUND/AIMS: Endoscopic band ligation (EBL) is an accepted method in the management of variceal bleeding; however, there is little evidence on the safety and feasibility of EBL for the closure of bowel perforation. In this study, we aimed to evaluate the technical feasibility and efficacy of EBL in iatrogenic colon perforation by using a canine model. METHODS: We established an iatrogenic colon perforation model by using seven beagle dogs. Longitudinal 1.5- to 1.7-cm colon perforations were created with a needle knife and an insulated-tip knife, and the perforation was subsequently closed with EBL. During a 2-week follow-up period, the animals were carefully monitored and then euthanized for pathologic examination. RESULTS: The EBL of iatrogenic colon perforations was successful in all dogs. The mean procedure time for EBL closure with one to three bands was 191.7 seconds, and there were no immediate complications. One animal was euthanized after 3 days because of peritonitis. There were no clinical and laboratory features of sepsis or peritonitis in the remaining six animals. On necropsy, we did not find any fecal peritonitis, pericolonic abscess formation, or transmural dehiscence at the perforation site. Histopathology demonstrated inflamed granulation tissue and scar lesions replaced by fibrosis. CONCLUSIONS: EBL might be a feasible and safe method for the management of iatrogenic colon perforations in an in vivo model.

Minimally invasive plate osteosynthesis using 3D printing for shaft fractures of clavicles: technical note.

This article describes a minimally invasive plate osteosynthesis technique for midshaft fractures of clavicles using intramedullary indirect reduction and prebent plates with 3D printing models. This technique allows for easy reduction of fractures with accurate prebent plates and minimal soft tissue injury around the fracture site.

Comparison of endoscopic band ligation and endoclip closure of colonic perforation: technical feasibility and efficacy in an ex vivo pig model.

BACKGROUND AND AIM: Recent reports have indicated several instances of successful treatment of bowel perforation by using endoscopic band ligation (EBL) when treatment with endoclipping is unsuccessful, but this salvage method has not been investigated in any prospective model. Herein we aimed to compare the technical feasibility and efficacy of EBL and endoclip use in intraluminal closure of colon perforation, in an ex vivo model. METHODS: Standardized colonic perforations were created using fresh porcine colon and subsequently closed by full-thickness interrupted sutures, endoclip (QuickClip2(TM)), or EBL. Each closure site was tested with compressed air by using a digital pressure monitor for evaluating leak pressure. RESULTS: No significant differences were noted between the endoclip and EBL in leak pressures. Mean (± SD) pressures for air leakage from the perforations closed using the different devices were as follows: normal colon samples, 52.0 ± 13.2 mmHg; perforations closed with hand-sewn sutures, 32.3 ± 8.3 mmHg; perforations closed with endoclipping, 53.5 ± 22.7 mmHg; and perforations closed with EBL, 50.4 ± 12.5 mmHg. Time taken for closure by EBL was significantly less than that for closure by endoclipping (3.2 ± 1.7 min vs 6.8 ± 1.3 min, P < 0.01). Further, the number of devices used to achieve complete closure in the EBL group was lower than that with endoclipping (1.6 ± 0.5 vs 3.7 ± 0.8, P < 0.01). CONCLUSION: Endoluminal closure of a 1.5-cm colon perforation with EBL decreased procedure time and was not inferior in leak pressure compared with endoclipping in this ex vivo porcine model.

Appraisal of antioxidant and anti-inflammatory activities of various extracts from the fruiting bodies of Pleurotus florida.

Pleurotus florida has been widely used for nutritional and medicinal purposes. The present study was conducted to evaluate the antioxidant and anti-inflammatory effects of the fruiting bodies of P. florida extracted with acetone, methanol, and hot water. The antioxidant activities of the acetone and methanol extracts of P. florida showed stronger inhibition of ß-carotene-linoleic acid compared to that of the hot water extract. The acetone extract (8 mg/mL) showed a high reducing power of 1.86. The acetone and methanol extracts showed more effective DPPH radical scavenging activities than the hot water extract. The chelating effect of the extracts at lower concentrations was significantly effective compared to that of the positive control. Thirteen phenolic compounds were detected from acetonitrile and hydrochloric acid solvent extracts. Nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in lipolysaccahride (LPS) stimulated RAW 264.7 cells, a murine macrophage cell line, were inhibited significantly by the mushroom extracts in a concentration dependent manner. The anti-inflammatory activity on carrageenan-induced edema in the rat hind-paw reduced significantly by the mushroom extracts. Therefore, we have demonstrated that P. florida fruiting bodies possess antioxidant and anti-inflammatory activites related to their inhibitory activities on NO production, iNOS protein expression, and carrageenan-induced paw edema in rats. The results suggest that the fruiting bodies of P. florida are a good source of natural antioxidant and anti-inflammatory agents.

A pilot study comparing 2 oxygen delivery methods for patients' comfort and administration of oxygen.

BACKGROUND: The traditional oxygen delivery methods for oxygen therapy are continuous flow oxygen (CFO) and demand oxygen delivery (DOD); however, oxygen waste is considerable in CFO, while DOD is uncomfortable for patients. Synchronized DOD (SDOD), which was designed to overcome the drawbacks of both CFO and DOD, supplies oxygen according to the patient's breathing pattern and the desired oxygen saving. This study was conducted to examine the overall performance of SDOD in terms of oxygen saturation (SpO2 ), patients' comfort, and oxygen saving ratio (SR). METHODS: Study subjects were patients who required oxygen for COPD or pneumonia. Patients received oxygen through nasal prongs by CFO and SDOD for 30 min each. SpO2 was measured every 10 min by pulse oximetry, and subjects recorded their level of comfort after 30 min. The flow of discharged oxygen was recorded to calculate SR. RESULTS: Ten subjects (median age, 68 y; range, 56-86 y) were enrolled. The SpO2 of patients during SDOD (97 ± 2%) was similar to that during CFO (96 ± 3%) with no statistically significant difference (P = .53). Subjects reported SDOD to be more comfortable than CFO. The comfort score of subjects treated with SDOD was 7.05 ± 2.07 (0: very uncomfortable, 10: very comfortable); this was significantly higher (P = .02) than the comfort score (5.20 ± 1.83) of subjects treated with CFO. The SR values set by clinicians were very similar to calculated SR values. CONCLUSIONS: SDOD appears to be more suitable for oxygen therapy than CFO when considering SpO2 , patients' comfort, and SR.

Curvature analysis of femoral shaft in total knee arthroplasty patient and control group.

For some patients with joint illnesses such as rheumarthritis or varus deformity, the total knee arthroplasty (TKA) procedures are performed. However, when inserting metal cutting guide for the procedures, due to the femoral shaft bowing, complications such as the cortex of the femoral shaft damages or secondary fractures can be caused. If the central coordinate value of the femoral shaft is known, the metal cutting guide could be inserted into the anatomical center, so such complications can be prevented. In this study, CT images of femoral shafts of 10 individuals in the experiment group who are in need of receiving the total knee arthroplasty procedures and those of 10 individuals in the control group without illness in the femoral shaft have been utilized to locate the 3-dimensional coordinate values. Then, Matlab was utilized to identify the central coordinate value in order to obtain a graph reflecting the anatomical shapes as well as to acquire the 3-dimensional curvature values by section. As a result, the average curvature range of femoral shafts of the experiment group was determined to be 631.2 mm whereas the average curvature range of femoral shafts of the control group was determined to be 1430.4 mm. The statistical significant of the measured results was verified through ANOVA analysis. Based on these results, it was verified that the level of curvature of the femoral shaft of the experiment group was higher. If the anatomical central points are located and analyzed using this methodology, it would be helpful in performing orthopedic operations such as the total knee arthroplasty.

A study on the artifacts generated by dental materials in PET/CT image.

PET/CT system reduces the scanning time and provides an anatomical image because it realizes a CT-based attenuation corrected image without using an isotope, such as 68 Ge or 137Cs, in the attenuation correcting method due to the recent technological development. On the other hand, artifacts are generated in a CT image by dental materials, which affect the attenuation corrected PET image. Against this backdrop, this study performed a clinical experiment and a phantom experiment. The clinical experiment targeted 40 patients without oral disease, including 20 patients who had metal prosthesis in their tooth and 20 patients who had a dental implant in tooth. In the phantom experiment, a dental cast was used for a PET/CT scan after the metal prosthesis and the dental implant was inserted in the original dental phantom to make a dental cast. According to the study results, when the patients had metal prosthesis, standard uptake value (SUV) decreased by approximately 19.6% in the dark streak artifact region and increased by approximately 90.1% in the bright streak artifact region, compared with the artifact free region. In the phantom with metal prosthesis, the SUV decreased by approximately 18.1% in the dark streak artifact region and increased by 18.0% in the bright streak artifact region, compared to the artifact free region. When the patients with dental implant, the SUV decreased by approximately 19.1% in the dark streak artifact region and increased by 96.6% in the bright streak artifact region, compared with the artifact free region. In the phantom with dental implant, the SUV decreased by approximately 14.4% in the dark streak artifact region and increased by 7.0% in the bright streak artifact region, compared to the artifact free region. Therefore, by considering these results, we can improve the diagnostic accuracy in oral and maxillofacial cancer.

Discussion on the alteration of 18F-FDG uptake by the breast according to the menstrual cycle in PET imaging.

18F-FDG PET/CT is a useful modality for identifying high-glucose-consuming cells, such as cancer cells by the glucose metabolism of FDG. FDG is taken up by cancer and inflammatory cells but occasionally, there is some FDG uptake on normal tissues as a result of their individual physiological characteristics. In particular, in fertile females, unusual FDG uptake in the breast changes according to the stages in the menstrual cycle, which can adversely affect a diagnosis. Therefore, this study examined the change in breast FDG uptake in the menstrual cycle on 18F-FDG PET/CT. One hundred and sixty females (34 ± 3.5 years old), who had not undergone a gynecologic anamnesis and had a regular menstrual cycle over the previous 6 months, were examined from March 2011 to February 2012. The subjects were divided into the following 4 groups (each with 40 patients): flow phase, proliferative phase, ovulatory phase and secretory phase using Pregnancy Calculator 0.14 and history taking. Discovery STE (GE Healthcare, USA) was used as the PET/CT. The SUVs on the accumulated region on the breast were analyzed, and 3 nuclear medicine specialists performed a blind test. The SUVs on the breast were the flow phase (1.64 ± 0.25), proliferative phase (0.93 ± 0.28), ovulatory phase (1.66 ± 0.26) and secretory phase (1.77 ± 0.28). Higher uptake values were observed in the secretory, flow phase and ovulatory phase (p< 0.05). The accumulation of the breast was divided into the following 3 grades compared to the lung and liver by gross analysis: the breast uptake was equal to the lung (Grade I); between the lung and liver (Grade II); and equal to or greater than the liver (Grade III). These results showed a high uptake value in the secretory, flow phase and ovulatory phase (p <0.05). In fertile females, the FDG uptake of the breast showed changes according to the menstrual cycle, which can be used to improve the diagnosis of breast disease. Therefore, the false-negative findings of breast disease can be reduced by performing an examination at the appropriate period through history taking and considering the individual menstrual cycle.