Low-iodine-dose computed tomography coupled with an artificial intelligence-based contrast-boosting technique in children: a retrospective study on comparison with conventional-iodine-dose computed tomography.

BACKGROUND: Low-iodine-dose computed tomography (CT) protocols have emerged to mitigate the risks associated with contrast injection, often resulting in decreased image quality. OBJECTIVE: To evaluate the image quality of low-iodine-dose CT combined with an artificial intelligence (AI)-based contrast-boosting technique in abdominal CT, compared to a standard-iodine-dose protocol in children. MATERIALS AND METHODS: This single-center retrospective study included 35 pediatric patients (mean age 9.2 years, range 1-17 years) who underwent sequential abdominal CT scans-one with a standard-iodine-dose protocol (standard-dose group, Iobitridol 350 mgI/mL) and another with a low-iodine-dose protocol (low-dose group, Iohexol 240 mgI/mL)-within a 4-month interval from January 2022 to July 2022. The low-iodine CT protocol was reconstructed using an AI-based contrast-boosting technique (contrast-boosted group). Quantitative and qualitative parameters were measured in the three groups. For qualitative parameters, interobserver agreement was assessed using the intraclass correlation coefficient, and mean values were employed for subsequent analyses. For quantitative analysis of the three groups, repeated measures one-way analysis of variance with post hoc pairwise analysis was used. For qualitative analysis, the Friedman test followed by post hoc pairwise analysis was used. Paired t-tests were employed to compare radiation dose and iodine uptake between the standard- and low-dose groups. RESULTS: The standard-dose group exhibited higher attenuation, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of organs and vessels compared to the low-dose group (all P-values < 0.05 except for liver SNR, P = 0.12). However, noise levels did not differ between the standard- and low-dose groups (P = 0.86). The contrast-boosted group had increased attenuation, CNR, and SNR of organs and vessels, and reduced noise compared with the low-dose group (all P < 0.05). The contrast-boosted group showed no differences in attenuation, CNR, and SNR of organs and vessels (all P > 0.05), and lower noise (P = 0.002), than the standard-dose group. In qualitative analysis, the contrast-boosted group did not differ regarding vessel enhancement and lesion conspicuity (P > 0.05) but had lower noise (P < 0.05) and higher organ enhancement and artifacts (all P < 0.05) than the standard-dose group. While iodine uptake was significantly reduced in low-iodine-dose CT (P < 0.001), there was no difference in radiation dose between standard- and low-iodine-dose CT (all P > 0.05). CONCLUSION: Low-iodine-dose abdominal CT, combined with an AI-based contrast-boosting technique exhibited comparable organ and vessel enhancement, as well as lesion conspicuity compared to standard-iodine-dose CT in children. Moreover, image noise decreased in the contrast-boosted group, albeit with an increase in artifacts.

Dual-photodiode radiometer design for simultaneous measurement of irradiance and centroid wavelength of light sources with finite spectral bandwidth.

We present the design of a radiometer that can simultaneously measure both centroid wavelength and irradiance of a light source without recording its spectrum, when the light source has a finite spectral bandwidth. It consists of two photodiodes separated with a beam splitter in its basic construction, which can be referred to as a dual-photodiode radiometer. This radiometer is calibrated by measuring the spectral responsivities of two photodiodes against the spectral irradiance at the input aperture. The concept of the simultaneous measurement is valid under the condition that the spectral responsivities are linear against wavelengths within the spectral bandwidth of the source to be tested. The feasibility and expected accuracy are analyzed by numerical simulations and experimentally tested for the realization of a UVA irradiance meter, which shows an agreement within 0.2 nm and 0.6% for centroid wavelength and irradiance, respectively, with other reference instruments.

20-O-ß-D-glucopyranosyl-20(S)-protopanaxadiol suppresses UV-Induced MMP-1 expression through AMPK-mediated mTOR inhibition as a downstream of the PKA-LKB1 pathway.

Various health effects have been attributed to the ginsenoside metabolite 20-O-ß-D-glucopyranosyl-20(S)-protopanaxadiol (GPD); however, its effect on ultraviolet (UV)-induced matrix metalloproteinase (MMP)-1 expression and the mechanism underlying this effect are unknown. We examined the inhibitory effect of GPD on UV-induced MMP-1 expression and its mechanisms in human dermal fibroblasts (HDFs). GPD attenuated UV-induced MMP-1 expression in HDFs and suppressed the UV-induced phosphorylation of mammalian target of rapamycin (mTOR) and p70(S6K) without inhibiting the activity of phosphatidylinositol 3-kinase and Akt, which are well-known upstream kinases of mTOR. GPD augmented the phosphorylation of liver kinase B1 (LKB1) and adenosine monophosphate-activated protein kinase (AMPK), which are inhibitors of mTOR, to a greater extent than UV treatment alone. Similar to GPD, 5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranosyl 5'-monophosphate (AICAR), an activator of AMPK, augmented UV-induced AMPK phosphorylation to a greater extent than UV treatment alone, resulting in the inhibition of MMP-1 expression. AICAR also decreased the phosphorylation of mTOR and p70(S6K). However, compound C, an antagonist of AMPK, increased MMP-1 expression. In HDF cells with AMPK knock-down using shRNA, MMP-1 expression was increased. These results indicate that AMPK activation plays a key role in MMP-1 suppression. Additionally, the cAMP-dependent protein kinase (PKA) inhibitor, H-89, antagonized GPD-mediated MMP-1 suppression via the inhibition of LKB1. Our results suggest that the suppressive activity of GPD on UV-induced MMP-1 expression is due to the activation of AMPK as a downstream of the PKA-LKB1 pathway.

Correlation between standardized uptake value of 18F-FDG PET/CT and conductivity with pathologic prognostic factors in breast cancer.

We investigated the correlation between standardized uptake value (SUV) of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and conductivity parameters in breast cancer and explored the feasibility of conductivity as an imaging biomarker. Both SUV and conductivity have the potential to reflect the tumors' heterogeneous characteristics, but their correlations have not been investigated until now. Forty four women diagnosed with breast cancer who underwent breast MRI and 18F-FDG PET/CT at the time of diagnosis were included. Among them, 17 women received neoadjuvant chemotherapy followed by surgery and 27 women underwent upfront surgery. For conductivity parameters, maximum and mean values of the tumor region-of-interests were examined. For SUV parameters, SUVmax, SUVmean, and SUVpeak of the tumor region-of-interests were examined. Correlations between conductivity and SUV were evaluated, and among them, the highest correlation was observed between mean conductivity and SUVpeak (Spearman's correlation coefficient = 0.381). In a subgroup analysis for 27 women with upfront surgery, tumors with lymphovascular invasion (LVI) showed higher mean conductivity than those without LVI (median: 0.49 S/m vs 0.06 S/m, p < 0.001). In conclusion, our study shows a low positive correlation between SUVpeak and mean conductivity in breast cancer. Furthermore, conductivity showed a potential to noninvasively predict LVI status.

Simultaneous production of 2'-fucosyllactose and difucosyllactose by engineered Escherichia coli with high secretion efficiency.

BACKGROUND AND AIM: Difucosyllactose (Di-FL) has strong antimicrobial activity against various pathogens, including group B Streptococcus, identified as the leading cause of neonatal sepsis. In this study, we sought to develop Escherichia coli as a microbial cell factory for efficiently producing Di-FL as well as 2'-fucosyllactose (2'-FL), the most abundant fucosylated oligosaccharide in human milk, by utilizing the salvage guanosine 5'-diphosphate (GDP)-l-fucose biosynthetic pathway. MAIN METHODS AND MAJOR RESULTS: The biosynthetic pathway for producing fucosylated oligosaccharides via the salvage pathway requires two enzymes, l-fucokinase/GDP-l-fucose phosphorylase (FKP) from Bacteroides fragilis and α-1,2-fucosyltransferase (FucT2) from Helicobacter pylori. To decrease the intracellular accumulation of 2'-FL while increasing substrate accessibility to FKP and FucT2, we evaluated whether extracellular secretion of FKP and FucT2 would enhance the production of fucosylated oligosaccharides. Among various engineered strains constructed in this study, the ΔLFAR-YA/FF+P-PLA2 strain expressing phospholipase A2 (PLA2 ) from Streptomyces violaceoruber, whose native signal peptide was replaced with the PelB signal peptide (P-PLA2 ), could secrete both FKP and FucT2 into the culture medium. Notably, it was observed that FKP and FucT2 present in the extracellular fraction could catalyze the synthesis of Di-FL from lactose and fucose. As a result, a batch fermentation with the ΔLFAR-YA/FF+P-PLA2 strain resulted in the production of 1.22 ± 0.01 g L-1 Di-FL and 0.47 ± 0.01 g L-1 2'-FL, whereas the control strain could only produce 0.65 ± 0.01 g L-1 2'-FL. CONCLUSIONS AND IMPLICATIONS: This study highlights the benefits of extracellular secretion of enzymes to improve biotransformation efficiency, as the transport of substrates and/or products across the cell membrane is limited.

Calcific tendinitis of the shoulder in the Korean population: demographics and its relation with coexisting rotator cuff tear.

BACKGROUND: To evaluate the demographics, clinical and radiographic features of calcific tendinitis of the shoulder in the Korean population, specifically focusing on the incidence of coexisting rotator cuff tear. METHODS: Between October 2014 and January 2015, we performed a prospective multicenter study with 506 patients from 11 training hospitals in Korea. We collected data of demographics and radiographic analysis based on simple radiographs, clinical assessments based on visual analog scale (VAS) and the American Shoulder Elbow Surgeons (ASES) score, and treatment modalities that are used currently. We also evaluated coexisting rotator cuff tear by ultrasonography (US) or magnetic resonance imaging (MRI) images. RESULTS: There were 402 female patients (79%) with mean age of 55 years (range, 31-87 years). Mean duration of symptoms was 16 months. Mean size of calcific materials was 11.4 mm (range, 0-35 mm). Mean value of VAS and ASES scores were 6.5 (range, 1-10) and 47 (range, 8-95), respectively. Of 383 patients (76%), 59 (15%) had rotator cuff tear including 15 full-thickness tears on US or MRI. Patients with rotator cuff tears were significantly associated with older age, recurrent symptoms, menstrual disorders in females, and having undergone calcification removal surgery and rotator cuff repair (all p<0.05). CONCLUSIONS: This study reported demographic, radiographic, and clinical features of calcific tendinitis of the shoulder in Korean population, which were not different from those of Western population. Coexisting rotator cuff tear was found with 15% incidence in this large series, suggesting that further radiographic study to evaluate rotator cuff tear might be needed in some calcific tendinitis patients of older age and presenting with recurrent symptoms.

Process specific differential metabolomes for industrial gochujang types (pepper paste) manufactured using white rice, brown rice, and wheat.

The metabolic perplexes for gochujang (GCJ) fermentative bioprocess, a traditional Korean pepper paste, has largely remain equivocal for preparative conditions and raw material (RM) additives exacerbating its commercial standardization. Herein, we outlined a differential non-targeted metabolite profiling for three GCJ (white rice-WR; brown rice-BR; wheat-WT) under varying processing steps (P1 - fermentation; P2 - meju addition; P3 - ripening; and P4 - red pepper addition). We correlated the process specific metabolomes with corresponding physicochemical factors, enzymatic phenotypes, and bioactivities for GCJ-types. The P1 was characterized by a uniform increase in the levels of RM-derived lysoPCs. In contrast, P2 was observed with proportionally higher levels of meju-released isoflavones and soyasaponins in WR-GCJ, followed by BR and WT-GCJ. The P3 involved a cumulative increase in primary metabolites in all GCJ samples except lower organic acid contents in WT-GCJ. The pepper derived flavonoids and alkaloids were selectively increased while P4 in all GCJ-types.

20-O-ß-d-glucopyranosyl-20(S)-protopanaxadiol, a metabolite of ginseng, inhibits colon cancer growth by targeting TRPC channel-mediated calcium influx.

Abnormal regulation of Ca(2+) mediates tumorigenesis and Ca(2+) channels are reportedly deregulated in cancers, indicating that regulating Ca(2+) signaling in cancer cells is considered as a promising strategy to treat cancer. However, little is known regarding the mechanism by which Ca(2+) affects cancer cell death. Here, we show that 20-O-ß-d-glucopyranosyl-20(S)-protopanaxadiol (20-GPPD), a metabolite of ginseng saponin, causes apoptosis of colon cancer cells through the induction of cytoplasmic Ca(2+). 20-GPPD decreased cell viability, increased annexin V-positive early apoptosis and induced sub-G1 accumulation and nuclear condensation of CT-26 murine colon cancer cells. Although 20-GPPD-induced activation of AMP-activated protein kinase (AMPK) played a key role in the apoptotic death of CT-26 cells, LKB1, a well-known upstream kinase of AMPK, was not involved in this activation. To identify the upstream target of 20-GPPD for activating AMPK, we examined the effect of Ca(2+) on apoptosis of CT-26 cells. A calcium chelator recovered 20-GPPD-induced AMPK phosphorylation and CT-26 cell death. Confocal microscopy showed that 20-GPPD increased Ca(2+) entry into CT-26 cells, whereas a transient receptor potential canonical (TRPC) blocker suppressed Ca(2+) entry. When cells were treated with a TRPC blocker plus an endoplasmic reticulum (ER) calcium blocker, 20-GPPD-induced calcium influx was completely inhibited, suggesting that the ER calcium store, as well as TRPC, was involved. In vivo mouse CT-26 allografts showed that 20-GPPD significantly suppressed tumor growth, volume and weight in a dose-dependent manner. Collectively, 20-GPPD exerts potent anticarcinogenic effects on colon carcinogenesis by increasing Ca(2+) influx, mainly through TRPC channels, and by targeting AMPK.

Ultrasonographic evaluation of the shoulder in elite wheelchair tennis players.

CONTEXT: Wheelchair tennis has been identified as a high-risk sport for shoulder injury, so understanding shoulder pathology in these athletes is important. OBJECTIVE: This study investigated the incidence and pattern of shoulder injuries in wheelchair tennis players using high-resolution ultrasonography. DESIGN: Descriptive study. SETTING: International Wheelchair Tennis Open. PARTICIPANTS: 33 elite-level wheelchair tennis players. OUTCOME MEASURES: Wheelchair tennis players completed a self-administered questionnaire, and shoulders of each athlete were investigated using high-resolution ultrasonography (linear probe 7.5 MHz). RESULTS: The most common pathology in the dominant shoulder was acromioclavicular pathology, in 21 players (63.6%). Full-thickness rotator-cuff tears involving the supraspinatus were found in 8 dominant shoulders and 6 nondominant shoulders. There were no correlations between identified shoulder pathology and the different variables studied, such as age, training time per day, length of wheelchair use, and length of career as a wheelchair tennis player. CONCLUSION: High prevalence of rotator-cuff and acromioclavicular pathology was found by ultrasonographic examination in the elite wheelchair tennis players in both dominant and nondominant shoulders. A high index of suspicion of these pathologies in wheelchair athletes is required.

Eating habits, obesity related behaviors, and effects of Danhak exercise in elderly Koreans.

The aims of this study were to evaluate obesity-related dietary behaviors and to determine long-term exercise effects on obesity and blood lipid profiles in elderly Korean subjects. A total of 120 subjects, aged 60-75 yr, were recruited, and obesity-related dietary behaviors were determined. An exercise intervention was conducted with 35 qualified elderly females for 6 months, and body composition and blood lipids were measured 6 times at 4 week intervals. At baseline, mean BMI (kg/m(2)) was 24.8 for males and 23.1 for females. The females had better eating habits than the males and were more concerned with reading nutrition labels on food products (P < 0.001); they also preferred convenience foods less than the male subjects (P < 0.05). Obese individuals were more likely than overweight or normal weight individuals to misperceive their weight (P < 0.001). Those with a high BMI responded feeling more depressed (P < 0.01), lacking self-confidence (P < 0.01), and feeling isolated (P < 0.01), as well as having more difficulty doing outdoor activities (P < 0.01). After exercise, body fat (%) and WHR were significantly reduced (P < 0.05), while body weight and BMI were also decreased without statistical significance. Total cholesterol and blood HDL were significantly improved (207.1 mg/dl vs. 182.6 mg/dl, HDL: 45.6 mg/dl vs. 50.6 mg/dl, P < 0.05). Other benefits obtained from exercise were improvements in self-confidence (26.4%), movement (22.6%), stress-relief (18.9%), and depression (13.2%). In conclusion, elderly females had better eating habits and were more concerned with nutrition information and healthy diets compared to elderly males. However, misperceptions of weight and obesity-related stress tended to be very high in females who were overweight and obese, which can be a barrier to maintain normal weight. Long-term Danhak practice, a traditional Korean exercise, was effective at reducing body fat (%) and abdominal obesity, and improved lipid profiles, self-confidence, and stress.

Synchrotron radiation-based irradiance calibration from 200 to 400 nm at the Synchrotron Ultraviolet Radiation Facility III.

A new facility for measuring irradiance in the UV was commissioned recently at the National Institute of Standards and Technology (NIST). The facility uses the calculable radiation from the Synchrotron Ultraviolet Radiation Facility as the primary standard. To measure the irradiance from a source under test, an integrating sphere spectrometer-detector system measures both the source under test and the synchrotron radiation sequentially, and the irradiance from the source under test can be determined. In particular, we discuss the calibration of deuterium lamps using this facility from 200 to 400 nm. This facility improves the current NIST UV irradiance scale to a relative measurement uncertainty of 1.2% (k=2).