Optimization and evaluation of Atrina pectinata polysaccharides recovered by subcritical water extraction: A promising path to natural products.

In this study, the recovery of Atrina pectinata posterior adductor polysaccharides (APP-PS) using subcritical water extraction (SWE) was optimized by response surface methodology (RSM) and the physicochemical and biological properties of the recovered APP-PS were evaluated. The optimal extraction conditions, which resulted in a maximum yield of 55.58 ± 1.12 %, were temperature, 152.08 °C; extraction time, 10 min; solid-liquid ratio, 30 g/600 mL. The obtained APP-PS was found to be 88.05 ± 0.17 % total sugar. Fourier transform infrared (FT-IR) and Nuclear magnetic resonance (NMR) analyses confirmed the presence of the α-coordination of D-glucan in the polymer sample. The analysis of monosaccharide composition, along with thermogravimetric analysis, revealed the typical structure of the sample, composed of glucose alone. Total phenolic contents of APP-PS were measured as 5.47 ± 0.01 mg Gallic acid/g of dry sample and total flavonoids contents were determined to be 0.78 ± 0.06 mg Quercetin/g of dry sample. For biological activities, ABTS+, DPPH and FRAP antioxidant activities were measured to be 20.00 ± 0.71, 2.35 ± 0.05 and 4.02 ± 0.07 µg Trolox equivalent/100 g of dry sample, respectively. Additionally ACE inhibitory was confirmed to be 87.02 ± 0.47 %. These results showed that SWE is an effective method to recover biofunctional materials from marine organisms.

Exploring Bioactive Compounds in Brown Seaweeds Using Subcritical Water: A Comprehensive Analysis.

In this study, we characterized the bioactive properties of three important brown seaweed species, Sargassum thunbergii, Undaria pinnatifida, and Saccharina japonica, by subcritical water extraction (SWE), as these species are well known for their beneficial health effects. Their physiochemical properties, including potential antioxidant, antihypertensive, and α-glucosidase inhibitory activity, and the antibacterial activity of the hydroysates were also analyzed. The highest total phlorotannin, total sugar content, and reducing sugar content in the S. thunbergii hydrolysates were 38.82 ± 0.17 mg PGE/g, 116.66 ± 0.19 mg glucose/g dry sample, and 53.27 ± 1.57 mg glucose/g dry sample, respectively. The highest ABTS+ and DPPH antioxidant activities were obtained in the S. japonica hydrolysates (124.77 ± 2.47 and 46.35 ± 0.01 mg Trolox equivalent/g, respectively) and the highest FRAP activity was obtained in the S. thunbergii hydrolysates (34.47 ± 0.49 mg Trolox equivalent/g seaweed). In addition, the seaweed extracts showed antihypertensive (≤59.77 ± 0.14%) and α-glucosidase inhibitory activity (≤68.05 ± 1.15%), as well as activity against foodborne pathogens. The present findings provide evidence of the biological activity of brown seaweed extracts for potential application in the food, pharmaceutical, and cosmetic sectors.

Changing Patterns of Causative Pathogens over Time and Efficacy of Empirical Antibiotic Therapies in Acute Cholangitis with Bacteremia.

Background/Aims: To select appropriate empirical antibiotics, updates on the changes in pathogens are essential. We aimed to investigate the changes in pathogens and their antibiotic susceptibility in acute cholangitis (AC) with bacteremia over a period of 15 years. Furthermore, the efficacy of empirical antibiotic therapies and the risk factors predicting antibiotic-resistant pathogens (ARPs) were analyzed. Methods: A total of 568 patients with AC and bacteremia who were admitted to Daegu Catholic University Medical Center from January 2006 to December 2020 were included. Their medical records were retrospectively reviewed. In addition, the data were grouped and analyzed at 3-year intervals under the criteria of Tokyo Guideline 2018. Results: During the study period, 596 pathogens were isolated from blood cultures of 568 patients. The three most common pathogens were Escherichia coli (50.5%), Klebsiella species (24.5%), and Enterococcus species (8.1%). The proportion of vancomycin-resistant Enterococci (VRE) has increased since the mid-2010 (0.0% to 4.3%, p=0.007). There was emergence of carbapenem-resistant Enterobacteriaceae (CRE) in 2018 to 2020, albeit not statistically significant (1.3%, p=0.096). Risk factors predicting ARP were healthcare-associated infection, history of previous biliary intervention, and the severity of AC. For patients with these aforementioned risk factors, imipenem was the most effective antibiotic and piperacillin-tazobactam was also effective but to a lesser degree (susceptibility rates of 92.1% and 75.0%, respectively). Conclusions: The proportion of VRE has increased and CRE has emerged in AC. In addition, healthcare-associated infection, history of previous biliary intervention, and the severity of AC were independent risk factors predicting ARP. For patients with these risk factors, the administration of imipenem or piperacillin-tazobactam should be considered.

Malignant potential of small pancreatic neuroendocrine neoplasm and its risk factors: A multicenter nationwide study.

BACKGROUND: Pancreatic neuroendocrine neoplasms (PNENs) show heterogeneous biological behavior, and most small PNENs show indolent features. Consequently, selected cases can be considered for observation only, according to the National Comprehensive Cancer Network guideline, however, supporting clinical evidence is lacking. We investigated the clinical course of small PNENs and their risk factors for malignant potential. METHODS: A total of 158 patients with small pathologically confirmed PNENs ≤2 cm in initial imaging were retrospectively enrolled from 14 institutions. The primary outcome was any metastasis or recurrence event during follow-up. RESULTS: The median age was 57 years (range, 22-82 years), and 86 patients (54%) were female. The median tumor size at initial diagnosis was 13 mm (range, 7-20 mm). PNENs were pathologically confirmed by surgery in 137 patients and by EUS-guided fine needle aspiration biopsy (EUS-FNAB) in 21 patients. Eight patients underwent EUS-FNAB followed by surgical resection. The results of WHO grade were available in 150 patients, and revealed 123 grade 1, 25 grade 2, and 2 neuroendocrine carcinomas. A total of 145 patients (92%) underwent surgical resection, and three patients had regional lymph node metastasis. During the entire follow-up of median 45.6 months, 11 metastases or recurrences (7%) occurred. WHO grade 2 (HR 13.97, 95% CI 2.60-75.03, p = 0.002) was the only predictive factor for malignant potential in multivariable analysis. CONCLUSIONS: WHO grade is responsible for the malignant potential of small PNENs ≤2 cm. Thus, EUS-FNAB could be recommended in order to provide early treatment strategies of small PNENs.

Effect of biliary stenting combined with ursodeoxycholic acid and terpene treatment on retained common bile duct stones in elderly patients: a multicenter study.

OBJECTIVES: For frail, elderly patients with large impacted common bile duct (CBD) stones, long-term treatment with biliary stenting provides palliation. Biliary stenting with choleretic agents such as ursodeoxycholic acid (UDCA) and terpene preparations may promote CBD stone size reduction. We studied the effectiveness of biliary stenting combined with UDCA and a terpene preparation as a medical treatment for difficult-to-remove CBD stones in patients older than 65 years in this multicenter, prospective study. METHODS: A total of 28 elderly patients with CBD stones refractory to conventional endoscopic removal, including mechanical lithotripsy, underwent endoscopic placement of a straight 10-F plastic biliary stent. Each patient was administered 600 mg of UDCA and 300 mg of a terpene preparation daily for a mean of 6 months. After 6 months of medication following the initial endoscopic retrograde cholangiopancreatography (ERCP), a second ERCP was performed and endoscopic stone removal was again attempted. Differences in stone size and CBD diameter before and after biliary stenting and medication were compared. The complete stone removal rate after treatment was obtained. RESULTS: The mean size (transverse x longitudinal diameter) of the CBD stones was initially 21.6 x 29.5 mm, and it decreased significantly to 12.2 x 20.1 mm at the second ERCP (P<0.01). The mean CBD diameter measured initially at the cystic duct insertion level was 23.2 mm, and it decreased significantly to 19.5 mm at the second ERCP (P<0.01). After biliary stenting with medication, endoscopic stone removal was successful in 26 of 28 patients (92.8%), with a mean of 1.7 subsequent ERCP sessions. CONCLUSIONS: Endoscopic biliary stenting with a period of combined UDCA and terpene preparation administration seems to be a safe and effective method for retained CBD stones in elderly patients. A prospective study with randomization and a control group is required to confirm these results.