Phase I Trial of SPECT-Guided Liver-Directed Radiotherapy for Patients with Low Functional Liver Volume.

BACKGROUND: Traditional constraints specify that 700 cc of liver should be spared a hepatotoxic dose when delivering liver-directed radiotherapy to reduce the risk of inducing liver failure. We investigated the role of single photon emission computed tomography (SPECT) to identify and preferentially avoid functional liver during liver-directed radiation treatment planning in patients with preserved liver function but limited functional liver volume after receiving prior hepatotoxic chemotherapy or surgical resection. METHODS: This phase I trial with a 3 + 3 design evaluated the safety of liver-directed radiotherapy using escalating functional liver radiation dose constraints in patients with liver metastases. Dose limiting toxicities (DLTs) were assessed 6-8 weeks and 6 months after completing radiotherapy. RESULTS: All twelve patients had colorectal liver metastases and received prior hepatotoxic chemotherapy. Eight patients underwent prior liver resection. Median computed tomography (CT) anatomical non-tumor liver volume was 1,584 cc (range 764-2,699 cc). Median SPECT functional liver volume was 1,117 cc (range 570-1,928cc). Median non-target CT and SPECT liver volumes below the volumetric dose constraint were 997 cc (range 544-1,576 cc) and 684 cc (range 429-1,244 cc), respectively. The prescription dose was 67.5-75 Gy in 15 fractions or 75-100 Gy in 25 fractions. No DLTs were observed during follow-up. One-year in-field control was 57%. One-year overall survival was 73%. CONCLUSION: Liver-directed radiotherapy can be safely delivered to high doses when incorporating functional SPECT into the radiation treatment planning process which may enable sparing of lower volumes of liver than traditionally accepted in patients with preserved liver function. TRIAL REGISTRATION: NCT02626312.

Application of sodium alginate-based edible coating with citric acid to improve the safety and quality of fresh-cut melon (Cucumis melo L.) during cold storage.

The safety and quality of fresh-cut melons is reduced by a series of decay processes by enzymatic browning and microbial contamination. This study aimed to assess the impact of a 2% sodium alginate-based edible coating (ALC) combined with different concentrations of citric acid (CA; 0.5%, 1%, 2%, and 3%) on the microbial safety and physical quality of fresh-cut melons during a 7-day storage period at 10 °C. The findings revealed that the combination of ALC and 3% CA was successful in preventing the growth of pathogenic bacteria (Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus) and natural microflora on fresh-cut melons during storage. In addition, treating fresh-cut melons with ALC containing 3% CA improved their quality by reducing browning and softening during storage at 10 °C. Based on these findings, it can be concluded that using ALC with 3% CA is an effective method to improve the safety and quality of fresh-cut melons.

Treatment of Pelvic and Spinal Bone Metastases: Radiotherapy and Hyperthermia Alone vs. in Combination.

Painful pelvic and spinal bone metastases are a considerable challenge for doctors and patients. Conventional therapies include morphine-equivalent medication (MeM) and local radiotherapy (RT), but these interventions are not always successful. More recently, hyperthermia (HT) has been applied to complement RT and MeM, and this complex approach has shown promising synergistic results. The objective of our study was to present the results of RT combined with a special kind of HT (modulated electrohyperthermia, mEHT), in which some of the thermal effect is contributed by equivalent nonthermal components, drastically reducing the necessary power and energy. This retrospective study included 61 patients divided into three groups with pelvic and spinal bone metastases to compare the effects of RT and mEHT alone and in combination (RT + mEHT). A detailed evaluation of pain intensity, measured by the brief pain inventory score, MeM use, and breakthrough pain episodes, revealed no significant differences between RT and mEHT alone; thus, these individual methods were considered equivalent. However, RT + mEHT yielded significantly better results in terms of the above parameters. Clinically, mEHT has a lower risk of adverse thermal effects, and due to its efficacy, mEHT can be used to treat RT-resistant lesions.

Differences in the prevalence of NAFLD, MAFLD, and MASLD according to changes in the nomenclature in a health check-up using MRI-derived proton density fat fraction.

PURPOSE: International expert panels proposed new nomenclatures, metabolic dysfunction-associated fatty liver disease (MAFLD) in 2020 and metabolic dysfunction-associated steatotic liver disease (MASLD) in 2023, along with revised diagnostic criteria to replace non-alcoholic fatty liver disease (NAFLD). We aimed to investigate the differences in NAFLD, MAFLD, and MASLD prevalence with changing nomenclature in a health check-up using magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) to assess hepatic steatosis. We also examined the prevalence of the sub-classifications of steatotic liver disease (SLD) and the differences in characteristics among the sub-categories. METHODS: We included 844 participants who underwent liver MRI-PDFF at our health check-up clinic between January 2020 and November 2022. Hepatic steatosis was defined as MRI-PDFF ≥ 5%. Participants were categorized according to NAFLD, MAFLD, MASLD, and sub-classifications of SLD. RESULTS: The prevalence rates of NAFLD, MAFLD, and MASLD were 25.9%, 29.5%, and 25.2%, respectively. 30.5% of the participants was categorized as SLD. The prevalence rates of the SLD sub-categories were 25.2% for MASLD, 3.7% for MASLD and alcohol-associated liver disease (MetALD), 0.1% for alcohol-associated liver disease, 1.3% for specific etiology SLD, and 0.1% for cryptogenic SLD. Compared with patients in the MASLD group, those in the MetALD group were younger, predominantly male, and exhibited higher levels of serum aspartate aminotransferase, gamma-glutamyl transpeptidase, and triglycerides. CONCLUSION: The prevalences of NAFLD and MASLD assessed using MRI-PDFF were similar, with MASLD accounting for 97.3% of the patients with NAFLD. The separate MetALD sub-category may have clinical characteristics that differ from those of MASLD.

Metabolomic Profiles in Patients with Cervical Cancer Undergoing Cisplatin and Radiation Therapy.

This study was aimed to evaluate endogenous metabolic changes before and after cisplatin and radiation therapy in patients with cervical cancer via untargeted metabolomic analysis using plasma samples. A total of 13 cervical cancer patients were enrolled in this study. Plasma samples were collected from each patient on two occasions: approximately one week before therapy (P1) and after completion of cisplatin and radiation therapy (P2). Of the 13 patients, 12 patients received both cisplatin and radiation therapy, whereas one patient received radiation therapy alone. The samples were analyzed using the Ultimate 3000 coupled with Q ExactiveTM Focus Hybrid Quadrupole-OrbitrapTM mass spectrometry (Thermo Fisher Scientific, Waltham, MA, USA). Chromatographic separation utilized a Kinetex C18 column 2.1×100 mm (2.6 µm) (Phenomenex, Torrance, CA, USA), and the temperature was maintained at 40°C. Following P2, there were statistically significant increases in the concentrations of indoxyl sulfate, phenylacetylglutamine, Lysophosphatidyethanolamine (LysoPE) (18:1), and indole-3-acetic acid compared with the concentrations observed at P1. Specifically, in the human papillomavirus (HPV) noninfection group, indoxyl sulfate, LysoPE (18:1), and phenylacetylglutamine showed statistically significant increases at P2 compared with P1. No significant changes in metabolite concentrations were observed in the HPV infection group. Indoxyl sulfate, LysoPE (18:1), phenylacetylglutamine, and indole-3-acetic acid were significantly increased following cisplatin and radiation therapy.

Korean Nursing Students' Experiences of Virtual Simulation Programs Replacing In-Person Mental Health Nursing Practicum during the COVID-19 Pandemic.

This qualitative study explored the experiences of nursing students whose clinical practice in mental health nursing had been substituted with virtual simulation programs due to the COVID-19 pandemic. The participants were ten nursing students who had undergone a virtual simulation program-centered practice, replacing the traditional clinical practice in mental health nursing and previous clinical practice in mental health nursing. The data were collected through in-depth individual interviews from January to February 2021. Following Braun and Clarke's method, the thematic analysis identified five themes and ten sub-themes. The five themes included the following: (1) lack of vibrancy in the actual clinical setting, (2) limited direct and indirect practical experience, (3) performing diverse roles in a virtual setting, (4) learner-directed practicum, and (5) sense of relief due to a safe virtual practicum environment. The participants recognized the limitations of the practice, particularly regarding communication with patients with mental disorders in the virtual simulation program. However, their perception of nursing underwent a positive change through the indirect clinical practice experience. Accordingly, it is necessary to develop a platform for the mental health nursing practicum that can easily interact with clients and to establish a hybrid practice that combines the clinical practice and virtual simulation practice.

Plasma Growth Hormone as a Prognostic Biomarker to Durvalumab and Tremelimumab in Patients with Advanced Hepatocellular Carcinoma.

Introduction: In this study, we explored the potential of plasma growth hormone (GH) as a prognostic biomarker in patients with advanced HCC treated with durvalumab plus tremelimumab (D+T). Methods: In this study, we included 16 patients with advanced HCC who received D+T at MD Anderson Cancer Center between 2022 and 2023 and had plasma GH measurements recorded before treatment. Plasma GH levels were measured from prospectively collected blood samples and were correlated with progression-free survival (PFS) and overall survival (OS). The cutoff for normal GH levels in women and men was defined as ≤3.7 µg/L and ≤0.9 µg/L, respectively. The Kaplan-Meier method was employed to compute the median OS and PFS, while the Log rank test was applied to compare the survival outcomes between the GH-high and GH-low groups. Results: Sixteen patients were included in this analysis, two female and fourteen male, with a median age of 65.5 years. At the time of the analysis, the 6-month OS rate was 100% among GH-low patients (6 patients) and 30% among GH-high patients (10 patients). OS was significantly longer in GH-low patients (not evaluable) compared to GH-high patients (3.94 months) (p = 0.030). PFS was also significantly longer in GH-low patients (not evaluable) compared to the GH-high patients (1.87 months) (p = 0.036). Conclusion: Plasma GH is a prognostic biomarker in patients with advanced HCC treated with D+T. Given the relatively small patient cohort size, this finding should be further validated in larger randomized clinical trials in advanced HCC patients.

Comprehensive Immunogenomic Profiling of IDH1-/2-Altered Cholangiocarcinoma.

PURPOSE: Isocitrate dehydrogenase (IDH)1/2 genomic alterations (GA) occur in 20% of intrahepatic cholangiocarcinoma (iCCA); however, the immunogenomic landscape of IDH1-/2-mutated iCCA is largely unknown. METHODS: Comprehensive genomic profiling (CGP) was performed on 3,067 cases of advanced iCCA. Tumor mutational burden (TMB), PD-L1 expression (Dako 22C3), microsatellite instability (MSI), and genomic loss of heterozygosity (gLOH) as a surrogate marker for homologous recombination deficiency were examined. RNA sequencing of 73 patient samples was analyzed for differences in stromal/immune cell infiltration, immune marker expression, and T-cell inflammation. Tissue microarray arrays were subjected to multiplex immunohistochemistry and colocalization analysis in 100 surgical samples. Retrospective clinical data were collected for 501 patients with cholangiocarcinoma to examine median overall survival (mOS) in IDH1/2+ versus IDHwt. RESULTS: Of 3,067 iCCA cases subjected to CGP, 426 (14%) were IDH1+ and 125 (4%) were IDH2+. IDH1 GA included R132C (69%) and R132L/G/S/H/F (16%/7%/4%/3%/<1%). IDH2 GA occurred at R172 (94.4%) and R140 (6.6%). No significant difference was seen in median gLOH between IDH1+ versus IDHwt iCCA (P = .37), although patterns of comutations differed. MSI-High (P = .009), TMB ≥10 mut/Mb (P < .0001), and PD-L1 positivity were lower in IDH1/2+ versus IDHwt iCCA. Resting natural killer cell population, CD70, and programmed cell death 1 expression were significantly higher in non-IDH1-mutated cases, whereas V-set domain containing T-cell activation inhibitor 1 (B7-H4) expression was significantly higher in IDH1+. No significant difference in mOS was observed between IDH1/2+ versus IDHwt patients. CONCLUSION: Significant differences in GA and immune biomarkers are noted between IDH1/2+ and IDHwt iCCA. IDH1-/2-mutated tumors appear immunologically cold without gLOH. These immunogenomic data provide insight for precision targeting of iCCA with IDH alterations.

Prediction of tumor recurrence after surgical resection of ampullary adenocarcinoma using magnetic resonance imaging.

OBJECTIVES: To predict tumor recurrence in patients who underwent surgical resection of ampullary adenocarcinoma using preoperative magnetic resonance (MR) imaging findings combined with clinical findings. METHODS: In this multicenter study, a total of 113 patients (mean age, 62.9 ± 9.8 years; 58 men and 55 women) with ampullary adenocarcinoma who underwent preoperative MR imaging and surgery with margin-negative resection between 2006 and 2017 were retrospectively included. The MR imaging findings were evaluated by two radiologists. Preoperative clinical findings were obtained. Cox proportional regression analyses were used to identify the independent prognostic factors for recurrence-free survival (RFS). A nomogram was created based on the multivariable analysis and was internally validated. RESULTS: Multivariable analysis revealed that presence of infiltrative tumor margin (hazard ratio [HR]: 2.18, p = 0.019), adjacent organ invasion (HR: 3.31, p = 0.006), adjacent vessel invasion (HR: 5.42, p = 0.041), peripancreatic lymph node enlargement (HR: 2.1, p = 0.019), and jaundice (HR: 1.93, p = 0.043) were significantly associated with worse RFS of ampullary adenocarcinoma after surgical resection. These MR imaging and clinical findings were used to construct a nomogram. On internal validation, the calibration plots showed excellent agreement between the predicted probabilities and the actual rates of tumor recurrence, with Harrell's c-index of 0.746. CONCLUSIONS: Combination of preoperative MR imaging and clinical findings can be useful for predicting tumor recurrence after surgical resection of ampullary adenocarcinoma. Identifying these features before surgery may aid in better treatment planning and management of these patients. CLINICAL RELEVANCE STATEMENT: A predictive nomogram using preoperative MR imaging and clinical findings can be useful in estimating the recurrence-free survival after surgical resection of ampullary adenocarcinoma. KEY POINTS: • Presently, tumor size on imaging is the only non-invasive factor that correlates with recurrence-free survival from ampullary adenocarcinoma; other factors are obtained postoperatively. • Infiltrative tumor margin, adjacent organ invasion, adjacent vessel invasion, peripancreatic lymph node enlargement on MRI, and jaundice are significant predictors for recurrence. • A nomogram incorporating significant MR imaging and clinical findings showed good performance in predicting recurrence-free survival, which can help in treatment planning.

Microbiological quality and safety of fresh mushroom products at retail level in Korea.

Several investigations and recalls have demonstrated that Listeria monocytogenes can occur on mushrooms. This study aimed to assess the microbiological quality and safety of four types of edible mushrooms (Flammulina velutipes, Pleurotus ostreatus, Pleurotus eryngii, and Agaricus bisporus) available in the Korean market, and to evaluate the prevalence of Listeria spp., including L. monocytogenes. Results revealed that out of 100 samples tested, 16% (32/200) were positive for Listeria spp. Of the Listeria-positive samples, five strains of Listeria innocua were detected. The total microbial counts ranged from 0.79 to 5.84 log CFU/g, with F. velutipes exhibiting the highest microbial load (mean 5.03 log CFU/g). These findings provide significant data for risk assessment and emphasize the need for continued monitoring of the microbiological safety of edible mushrooms.

Genome-wide association study identifies high-impact susceptibility loci for HCC in North America.

BACKGROUND AND AIMS: Despite the substantial impact of environmental factors, individuals with a family history of liver cancer have an increased risk for HCC. However, genetic factors have not been studied systematically by genome-wide approaches in large numbers of individuals from European descent populations (EDP). APPROACH AND RESULTS: We conducted a 2-stage genome-wide association study (GWAS) on HCC not affected by HBV infections. A total of 1872 HCC cases and 2907 controls were included in the discovery stage, and 1200 HCC cases and 1832 controls in the validation. We analyzed the discovery and validation samples separately and then conducted a meta-analysis. All analyses were conducted in the presence and absence of HCV. The liability-scale heritability was 24.4% for overall HCC. Five regions with significant ORs (95% CI) were identified for nonviral HCC: 3p22.1, MOBP , rs9842969, (0.51, [0.40-0.65]); 5p15.33, TERT , rs2242652, (0.70, (0.62-0.79]); 19q13.11, TM6SF2 , rs58542926, (1.49, [1.29-1.72]); 19p13.11 MAU2 , rs58489806, (1.53, (1.33-1.75]); and 22q13.31, PNPLA3 , rs738409, (1.66, [1.51-1.83]). One region was identified for HCV-induced HCC: 6p21.31, human leukocyte antigen DQ beta 1, rs9275224, (0.79, [0.74-0.84]). A combination of homozygous variants of PNPLA3 and TERT showing a 6.5-fold higher risk for nonviral-related HCC compared to individuals lacking these genotypes. This observation suggests that gene-gene interactions may identify individuals at elevated risk for developing HCC. CONCLUSIONS: Our GWAS highlights novel genetic susceptibility of nonviral HCC among European descent populations from North America with substantial heritability. Selected genetic influences were observed for HCV-positive HCC. Our findings indicate the importance of genetic susceptibility to HCC development.

Comparison between the GastroPanel test and the serum pepsinogen assay interpreted with the ABC method-A prospective study.

BACKGROUND AND AIMS: This study aimed to validate Helicobacter pylori serological and pepsinogen (PG) assays for detecting infection and gastric neoplasm. METHODS: Individuals who underwent serum Chorus H. pylori and HBI PG assays were included from May to September 2023. The GastroPanel test was performed using the same blood sample. HBI assay findings were interpreted with the ABC method using the criteria of corpus atrophy (PG I ≤ 70 ng/mL & I/II ≤3) and advanced corpus atrophy (PG I ≤ 30 ng/mL & I/II ≤2). RESULTS: A total of 144 H. pylori-infected and 184 non-infected Koreans were analyzed. The Chorus test (sensitivity 97.2%, specificity 89.1%) showed higher area under the curve (0.993 vs. 0.972, p = 0.003) than the GastroPanel test (sensitivity 95.8%, specificity 86.4%). Using the GastroSoft application, the incidence of gastric neoplasms was highest in the corpus atrophy group (50%), followed by the low acid-output (25.8%), H. pylori infection (11.6%), and antral atrophy (9.1%) groups. There were no gastric neoplasms in the normal and high acid output groups. Using the ABC method, the incidence of gastric neoplasms was highest in the corpus atrophy groups (23.8% in Groups C and D), followed by Group B (12.3%) and Group A (2.4%). Corpus atrophy interpreted with the GastroSoft showed poor agreement (k = 0.225) with corpus atrophy interpreted with the ABC method, whereas it showed excellent agreement (k = 0.854) with advanced corpus atrophy. CONCLUSIONS: Although the Chorus test was more accurate than the GastroPanel test, both assays discriminated high-risk individuals by detecting atrophy or infection. There were no gastric neoplasms in the normal or high acid-output groups (GastroSoft application), and gastric neoplasm incidence was lowest in Group A (ABC method). Corpus atrophy determined by GastroSoft application is more consistent with advanced corpus atrophy determined by the ABC method than is corpus atrophy.

Structurally robust lithium-rich layered oxides for high-energy and long-lasting cathodes.

O2-type lithium-rich layered oxides, known for mitigating irreversible transition metal migration and voltage decay, provide suitable framework for exploring the inherent properties of oxygen redox. Here, we present a series of O2-type lithium-rich layered oxides exhibiting minimal structural disordering and stable voltage retention even with high anionic redox participation based on the nominal composition. Notably, we observe a distinct asymmetric lattice breathing phenomenon within the layered framework driven by excessive oxygen redox, which includes substantial particle-level mechanical stress and the microcracks formation during cycling. This chemo-mechanical degradation can be effectively mitigated by balancing the anionic and cationic redox capabilities, securing both high discharge voltage (~ 3.43 V vs. Li/Li+) and capacity (~ 200 mAh g-1) over extended cycles. The observed correlation between the oxygen redox capability and the structural evolution of the layered framework suggests the distinct intrinsic capacity fading mechanism that differs from the previously proposed voltage fading mode.

The impact of a modified microbiota-accessible carbohydrate diet on gut microbiome and clinical symptoms in colorectal cancer patients following surgical resection.

A high-fiber diet is widely recognized for its positive effects on the gut microbiome. However, the specific impact of a high-fiber diet on the gut microbiome and bowel habits of patients with colon cancer remains poorly understood. In this study, we aimed to assess the effects of a modified microbiota-accessible carbohydrate (mMAC) diet on gut microbiota composition and clinical symptoms in colon cancer patients who underwent surgical resection. To achieve this, we enrolled 40 patients in two groups: those who received adjuvant chemotherapy and those who did not. Fecal samples were collected before and after dietary interventions for microbial and metabolite analyses. Each group was randomized in a 1: 1 ratio to follow either a 3-week conventional diet followed by a 3-week mMAC diet, or the reverse sequence. Although there were no significant differences in the microbial diversity data before and after the mMAC diet in both the non-chemotherapy and chemotherapy groups, distinct differences in gut microbial composition were revealed after the mMAC diet. Specifically, the abundance of Prevotella, which is associated with high-fiber diets, was further elevated with increased concentrations of acetate and propionate after the mMAC diet. Additionally, patients who experienced improved diarrhea and constipation after the mMAC diet exhibited an enrichment of beneficial bacteria and notable changes in metabolites. In conclusion, this study provides valuable insights into the potential benefits of the mMAC diet, specifically its impact on the gut microbiome and clinical symptoms in postoperative colorectal cancer (CRC) patients. These findings emphasize the potential role of a high-fiber diet in influencing the gut microbiome, and the clinical symptoms warrant further investigation.

Importance, performance frequency, and predicted future importance of dietitians' jobs by practicing dietitians in Korea: a survey study.

PURPOSE: This study aimed to explore the perceptions held by practicing dietitians of the importance of their tasks performed in current work environments, the frequency at which those tasks are performed, and predictions about the importance of those tasks in future work environments. METHODS: This was a cross-sectional survey study. An online survey was administered to 350 practicing dietitians. They were asked to assess the importance, performance frequency, and predicted changes in the importance of 27 tasks using a 5-point scale. Descriptive statistics were calculated, and the means of the variables were compared across categorized work environments using analysis of variance. RESULTS: The importance scores of all surveyed tasks were higher than 3.0, except for the marketing management task. Self-development, nutrition education/counseling, menu planning, food safety management, and documentation/data management were all rated higher than 4.0. The highest performance frequency score was related to documentation/data management. The importance scores of all duties, except for professional development, differed significantly by workplace. As for predictions about the future importance of the tasks surveyed, dietitians responded that the importance of all 27 tasks would either remain at current levels or increase in the future. CONCLUSION: Twenty-seven tasks were confirmed to represent dietitians' job functions in various workplaces. These tasks can be used to improve the test specifications of the Korean Dietitian Licensing Examination and the curriculum of dietetic education programs.

Correction to: Toxigenic diversity of Bacillus cereus isolated from fresh produce and effects of various factors on the growth and the cytotoxicity of B. cereus.

[This corrects the article DOI: 10.1007/s10068-023-01330-0.].

Revisiting the Malignant Masquerade at the Liver Hilum: Have We Made Progress?

BACKGROUND: Distinguishing malignant from benign causes of obstruction at the liver hilum can pose a diagnostic dilemma. This study aimed to determine factors that predict benign causes of hilar obstruction and long-term outcomes after resection. METHODS: Consecutive patients who underwent surgery for hilar obstruction at a single institution between 1997 and 2022 were retrospectively analyzed. Median follow-up was 26 months (range 0-281 months). RESULTS: Among 182 patients who underwent surgery for hilar obstruction, 25 (14%) patients were found to have benign disease. Median CA19-9 level after normalization of serum bilirubin was 80 U/mL (range 1-5779) and 21 U/mL (range 1-681) among patients with malignant and benign strictures, respectively (p = 0.001). Cross-sectional imaging features associated with malignancy were lobar atrophy, soft tissue mass/infiltration, and vascular involvement (all p < 0.05). Factors not correlated with malignancy were jaundice upon presentation, peak serum bilirubin, sex, and race. Preoperative bile duct brushing or biopsy had sensitivity and specificity rates of 82% and 55%, respectively. Among patients who underwent resection with curative intent, grade 3-4 complications occurred in 55% and 29% of patients with malignant and benign strictures, respectively (p = 0.028). Postoperative long-term complications of chronic portal hypertension and recurrent cholangitis occurred in ≥ 10% of patients with both benign and malignant disease (p = non-significant). CONCLUSIONS: Strictures at the liver hilum continue to present diagnostic and management challenges. Postoperative complications and long-term sequelae of portal hypertension and recurrent cholangitis develop in a significant number of patients after resection of both benign and malignant strictures.

Effect of precursors and stress factors on yeast isolated from fermented maesil extract and their biogenic amine formation.

Biogenic amines are produced during fermentation and can act as harmful substances. Strains related to the fermentation of maesil extract were identified and Clavispora lusitaniae and Pichia kluyveri were selected to investigate the relationship between biogenic amines and precursors, NaCl or ethanol. Biogenic amines were analyzed by high-performance liquid chromatography. Among precursors added, arginine was most effective for the biogenic amines formation. After 24 h incubation, the content of total biogenic amines increased from 37.60 to 51.75 mL/L for C. lusitaniae and from 2.60 to 33.30 mL/L for P. kluyveri in arginine-added medium. The number of yeast decreased in both NaCl- and ethanol-YM broth added with arginine, but there was no correlation between the number of yeast and biogenic amines. These results suggested that the formation of biogenic amines by yeast was affected by various factors and their interactions rather than a single factor, such as decarboxylase activity and stress factor. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01328-8.

Toxigenic diversity of Bacillus cereus isolated from fresh produce and effects of various factors on the growth and the cytotoxicity of B. cereus.

This study analyzed the virulence, growth characteristics, and cytotoxicity of Bacillus cereus strains isolated from fresh produce, including romaine lettuce, sesame leaf, tomato, and cucumber grown by different methods. Polymerase chain reaction (PCR) was used to assess the toxigenic potential, and the cytotoxicity of B. cereus was estimated using cell-free supernatant in HEp-2 cells. The study found that hblD was the predominant diarrheal enterotoxin in the 59 isolated B. cereus strains, followed by nheB and hblC. The optimal temperatures for growth ranged from 42 to 44 °C, with the highest growth rates and shortest lag times. Cytotoxicity varied greatly depending on abiotic factors, including NaCl, pH, and medium, and was not always correlated with cell population. The study highlights the importance of establishing control measures to prevent B. cereus intoxication in fresh vegetables. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01330-0.