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For the first time, phytochemical constituents of the leaves of Heptapleurum ellipticum were investigated. One rare new 2,28-bidesmosidic lupane-type saponin, named heptaellipside A (1), along with four other lupane-type analogs (2-5) were purified by combining differently chromatographic methods. All of the separated compounds (1-5) were communicated for the first time from H. ellipticum. The structures of them were definitely illustrated following extensive and comprehensive UV/VIS, FTIR, HRMS/ESI, and NMR techniques. Further, all isolated compounds were evaluated for their α-glucosidase and α-amylase inhibition. As the results, compound 3 respectively exhibited stronger in both inhibitory activities against α-glucosidase and α-amylase (IC50 values of 15.53 and 26.93 µM), than the acarbose standard (IC50 values of 214.50 and 143.48 µM).
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BACKGROUND: Despite advancements in chronic myeloid leukemia (CML) therapy with tyrosine kinase inhibitors (TKIs), resistance and intolerance remain significant challenges. Leukemia stem cells (LSCs) and TKI-resistant cells rely on altered mitochondrial metabolism and oxidative phosphorylation. Targeting rewired energy metabolism and inducing non-apoptotic cell death, along with the release of damage-associated molecular patterns (DAMPs), can enhance therapeutic strategies and immunogenic therapies against CML and prevent the emergence of TKI-resistant cells and LSC persistence. METHODS: Transcriptomic analysis was conducted using datasets of CML patients' stem cells and healthy cells. DNA damage was evaluated by fluorescent microscopy and flow cytometry. Cell death was assessed by trypan blue exclusion test, fluorescent microscopy, flow cytometry, colony formation assay, and in vivo Zebrafish xenografts. Energy metabolism was determined by measuring NAD+ and NADH levels, ATP production rate by Seahorse analyzer, and intracellular ATP content. Mitochondrial fitness was estimated by measurements of mitochondrial membrane potential, ROS, and calcium accumulation by flow cytometry, and morphology was visualized by TEM. Bioinformatic analysis, real-time qPCR, western blotting, chemical reaction prediction, and molecular docking were utilized to identify the drug target. The immunogenic potential was assessed by high mobility group box (HMGB)1 ELISA assay, luciferase-based extracellular ATP assay, ectopic calreticulin expression by flow cytometry, and validated by phagocytosis assay, and in vivo vaccination assay using syngeneic C57BL/6 mice. RESULTS: Transcriptomic analysis identified metabolic alterations and DNA repair deficiency signatures in CML patients. CML patients exhibited enrichment in immune system, DNA repair, and metabolic pathways. The gene signature associated with BRCA mutated tumors was enriched in CML datasets, suggesting a deficiency in double-strand break repair pathways. Additionally, poly(ADP-ribose) polymerase (PARP)1 was significantly upregulated in CML patients' stem cells compared to healthy counterparts. Consistent with the CML patient DNA repair signature, treatment with the methylated indolequinone MAC681 induced DNA damage, mitochondrial dysfunction, calcium homeostasis disruption, metabolic catastrophe, and necroptotic-like cell death. In parallel, MAC681 led to PARP1 degradation that was prevented by 3-aminobenzamide. MAC681-treated myeloid leukemia cells released DAMPs and demonstrated the potential to generate an immunogenic vaccine in C57BL/6 mice. MAC681 and asciminib exhibited synergistic effects in killing both imatinib-sensitive and -resistant CML, opening new therapeutic opportunities. CONCLUSIONS: Overall, increasing the tumor mutational burden by PARP1 degradation and mitochondrial deregulation makes CML suitable for immunotherapy.
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BACKGROUND: During the COVID-19 pandemic, many community-based organizations serving Asian Americans pivoted to provide web-based care and social services. Asian American community leaders in the United States Pacific Northwest, including Asian Health & Service Center expressed that there are older immigrant adults who experienced backlash from discrimination, fear, and anxiety owing in part to anti-Asian hate and isolation, including from infection precautions. Pivoting supported staying safe from COVID-19 transmission and anti-Asian hate crimes. OBJECTIVE: This study aims to examine the readiness of diverse groups of older Asian American immigrant adults (Chinese, Koreans, and Vietnamese) to use a web-based senior center, including technology access and telehealth use, and to identify the psychosocial health impacts that a web-based senior center could be positioned to meet. METHODS: A community-based participatory research approach was used to conduct a cross-sectional survey study in an Asian-based health and service center in 2022. We selected surveys from the National Institutes of Health-supported PhenX Toolkit. Analyses were performed using R software. RESULTS: There was an 88.2% (216/245) response rate. Overall, 39.8% (86/216) of participants were Chinese, 25% (54/216) were Korean, and 24.5% (53/216) were Vietnamese. There were significant group differences in mobile data plans (P=.0005). Most had an unlimited mobile data plan (38/86, 44% Chinese; 39/54, 72% Koreans; 25/53, 47% Vietnamese). Significant group differences existed regarding whether they started using a new electronic device to communicate with friends or family after the COVID-19 outbreak (P=.0005); most were Korean participants (31/54, 57%). For written text and audio or video apps, most Chinese participants used WeChat (65/85, 76%; 57/84, 68%, respectively), most Koreans used KakaoTalk (49/54, 91%; 49/54, 91%, respectively), and most Vietnamese used Facebook Messenger for written text (32/50, 64%) and Apple Face Time (33/50, 66%) or Facebook Messenger (31/50, 62%) for audio or video. Significant group differences existed regarding whether to try telehealth (P=.0005); most Vietnamese expressed that they would never consider it (41/53, 77%). Significant group differences existed regarding how well they were able to concentrate (χ22=44.7; P<.0001); Chinese participants reported a greater inability (median 5, IQR 4-6). With regard to difficulties in life experiences (χ22=51; P<.0001), the median was 6 (IQR 5-7) for the Vietnamese group. Significant group differences existed in having had a family/household member's salary, hours, and contracts reduced (P=.0005) and having had a family/household member or friend fallen physically ill (P=.0005)-most Vietnamese (15/53, 28%) and Korean participants (10/53, 19%). CONCLUSIONS: To build an efficacious, web-based senior center with web-based care and social service options, more older adults need access to the internet and education about using technology-enabled communication devices. Addressing the unique psychosocial impacts of the COVID-19 pandemic on each group could improve health equity. The strength of the participating older adults was observed and honored.
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The effect of plasma-activated water (PAW) generated with a dielectric barrier discharge diffusor (DBDD) system on microbial load and organoleptic quality of cucamelons was investigated and compared to the established sanitizer, sodium hypochlorite (NaOCl). Pathogenic serotypes of Escherichia coli, Salmonella enterica, and Listeria monocytogenes were inoculated onto the surface of cucamelons (6.5 log CFU g-1) and into the wash water (6 log CFU mL-1). PAW treatment involved 2 min in situ with water activated at 1,500 Hz and 120 V and air as the feed gas; NaOCl treatment was a wash with 100 ppm total chlorine; control treatment was a wash with tap water. PAW treatment produced a 3-log CFU g-1 reduction of pathogens on the cucamelon surface without negatively impacting quality or shelf life. NaOCl treatment reduced the pathogenic bacteria on the cucamelon surface by 3 to 4 log CFU g-1; however, this treatment also reduced fruit shelf life and quality. Both systems reduced 6-log CFU mL-1 pathogens in the wash water to below detectable limits. The critical role of superoxide anion radical (·O2-) in the antimicrobial power of DBDD-PAW was demonstrated through a Tiron scavenger assay, and chemistry modeling confirmed that ·O2- generation readily occurs in DBDD-PAW generated with the employed settings. Modeling of the physical forces produced during plasma treatment showed that bacteria likely experience strong local electric fields and polarization. We hypothesize that these physical effects synergize with reactive chemical species to produce the acute antimicrobial activity seen with the in situ PAW system. IMPORTANCE Plasma-activated water (PAW) is an emerging sanitizer in the fresh food industry, where food safety must be achieved without a thermal kill step. Here, we demonstrate PAW generated in situ to be a competitive sanitizer technology, providing a significant reduction of pathogenic and spoilage microorganisms while maintaining the quality and shelf life of the produce item. Our experimental results are supported by modeling of the plasma chemistry and applied physical forces, which show that the system can generate highly reactive ·O2- and strong electric fields that combine to produce potent antimicrobial power. In situ PAW has promise in industrial applications as it requires only low power (12 W), tap water, and air. Moreover, it does not produce toxic by-products or hazardous effluent waste, making it a sustainable solution for fresh food safety.
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Antiinfecciosos , Desinfectantes , Salmonella enterica , Microbiología de Alimentos , Frutas/microbiología , Recuento de Colonia Microbiana , Manipulación de Alimentos/métodos , Desinfectantes/farmacologíaRESUMEN
A new pregnane steroid, jasminanthoside (1), together with three known compounds, telosmoside A7 (2), syringaresinol (3), and methyl 6-deoxy-3-O-methyl-ß-D-allopyranosyl-(1â4)-ß-D-oleandropyranoside (4) were isolated from the ethyl acetate extract of Jasminanthes tuyetanhiae roots collected in Vietnam. Their chemical structures were elucidated by NMR and MS spectroscopic data analysis along with the comparison of their data with the published ones in the literature. Although 4 was a known compound, its full NMR data were reported for the first time. All isolated compounds, evaluated for their α-glucosidase inhibition, showed activities stronger than the positive control acarbose. Among them, 1 was the best with the IC50 value of 7.41 ± 0.59 µM.
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Monometallic catalysts based on Fe, Ni and Pd, as well as bimetallic catalysts based on Fe-Pd and based on Ni-Pd supported on silica, were synthesized using a sol-gel cogelation process. These catalysts were tested in chlorobenzene hydrodechlorination at low conversion to consider a differential reactor. In all samples, the cogelation method allowed very small metallic nanoparticles of 2-3 nm to be dispersed inside the silica matrix. Nevertheless, the presence of some large particles of pure Pd was noted. The catalysts had specific surface areas between 100 and 400 m2/g. In view of the catalytic results obtained, the Pd-Ni catalysts are less active than the monometallic Pd catalyst (<6% of conversion) except for catalysts with a low proportion of Ni (9% of conversion) and for reaction temperatures above 240 °C. In this series of catalysts, increasing the Ni content increases the activity but leads to an amplification of the catalyst deactivation phenomenon compared to Pd alone. On the other hand, Pd-Fe catalysts are more active with a double conversion value compared to a Pd monometallic catalyst (13% vs. 6%). The difference in the results obtained for each of the catalysts in the Pd-Fe series could be explained by the greater presence of the Fe-Pd alloy in the catalyst. Fe would have a cooperative effect when associated with Pd. Although Fe is inactive alone for chlorobenzene hydrodechlorination, when Fe is coupled to another metal from the group VIIIb, such as Pd, it allows the phenomenon of Pd poisoning by HCl to be reduced.
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Mukbang is widely recognized as a new type of food video on user-generated content (UGC) platforms. The purpose of this study was to identify motivators to watch mukbangs and to examine the relationship between these motivators and the intention to watch mukbangs via attitudes toward mukbangs and para-social relationships. In addition, this study examined how the intention to watch mukbangs affected purchase intention. Interviews were conducted to determine the motivation factors for watching mukbangs by collecting data from mukbang viewers. The results of the interviews suggested that vicarious satisfaction, enjoyment, information, exposure, and attractiveness were motivators for watching mukbangs. Using a survey, this study collected data from 399 participants who watched mukbangs to test relationships. Using SmartPLS, structural equation modeling (SEM) was conducted. The outcomes of the SEM indicated that vicarious satisfaction, enjoyment, and information influenced the intention to watch mukbangs via attitudes toward mukbangs. The results also indicated that exposure and attractiveness had an impact on the intention to watch mukbangs via para-social relationships. Furthermore, the intention to watch mukbangs influenced the intention to purchase food items portrayed in the mukbang content. This study contributes to the literature by empirically confirming the effect of watching mukbang on purchase intention.
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BACKGROUND: Asian American (AA) community leaders, Native Hawaiian/Pacific Islander (NH/PI) community leaders, and allies in the United States Pacific Northwest expressed concern that there are families and children from AA communities and NH/PI communities who experience and witness acts of xenophobia and racism. This can cause racial trauma. The long-time practice of aggregating AA and NH/PI data contributes to erasure and makes it challenging to advance health equity, such as allocating resources. According to AAPI Data's long-awaited report in June 2022, there are over 24 million AAs and 1.6 million NHs/PIs in the United States, growing by 40% and 30%, respectively, between 2010 and 2020. Philanthropic investments have not kept up with this substantive increase. The National Academies of Sciences, Engineering, and Medicine emphasized the need for effective partnerships to advance the health and well-being of individuals and communities in antiracism and system-level research. OBJECTIVE: The aim of this community-based participatory research qualitative description study was to identify perceptions and experiences regarding racial discrimination, race-based stress, and racial trauma; intergenerational healing and resiliency; and sharing the body with science from key informants of an academic and community partnership to inform antiracism coalition work. This partnership includes academic researchers and community leaders from community-based organizations and a health care organization serving immigrant and marginalized communities, including AAs and NHs/PIs in the United States Pacific Northwest. METHODS: In total, 10 key informants joined 1 of 2 participatory group discussions via videoconference for 2 hours in 2022. We used a semistructured and open-ended group interview guide. A qualitative participatory group-level assessment was conducted with the key informants and transcribed. Interpretations and meanings of the main points and the main themes were reflected upon, clarified, and verified with the key informants in real time. The field note-based data transcripts were manually coded using conventional content analysis. Reflexivity was used. RESULTS: There were 6 main themes: prejudice plus power in racism definition and working in solidarity to counter lateral oppression/false sense of security, microaggression as multilayers, "not assimilationist by nature" and responding differently to white superiority, intergenerational- and identity-related trauma, what is healing among People of Color and through a lens of resiliency and intergenerational connection and knowledge, and mistrust and fear in the research and health care systems surrounding intentions of the body. CONCLUSIONS: The themes highlight the importance of internal and intergenerational healing from racial trauma and the need for solidarity among communities of color to combat white supremacy and colonization. This work was foundational in an ongoing effort to dismantle racism and uplift the community voice through a cross-sector academic and community partnership to inform antiracism coalition work.
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BACKGROUND: Most vascular events after stroke may be prevented by modifying vascular risk factors through medical and behavioral interventions. Stroke literacy-an understanding of stroke symptoms, risk factors, and treatment-likely contributes to vascular risk factor control and in turn stroke recurrence risk. Stroke literacy is the lowest among adults belonging to racial and ethnic minority populations in the United States. Video-based interventions targeting stroke literacy may help acute stroke survivors understand stroke and subsequently reduce the risk of stroke recurrence. However, the failure of prior stroke literacy interventions may be due in part to the fact that the interventions were not theory-driven. Intervention mapping (IM) provides a framework for use in the development, implementation, and evaluation of evidence-informed, health-related interventions. OBJECTIVE: We aimed to develop a video-based educational intervention to improve stroke literacy in hospitalized patients with acute stroke. METHODS: The 6-step iterative process of IM was used to develop a video-based educational intervention and related implementation and evaluation plans. The six steps included a needs assessment, the identification of outcomes and change objectives, the selection of theory- and video-based intervention methods and practical applications, the development of a video-based stroke educational intervention, plans for implementation, and evaluation strategies. RESULTS: A 5-minute video-based educational intervention was developed. The IM approach led to successful intervention development by emphasizing stakeholder involvement, generation and adoption, and information retainment in the planning phase of the intervention. A planned approach to video adoption, implementation, and evaluation was also developed. CONCLUSIONS: An IM approach guided the development of a 5-minute video-based educational intervention to promote stroke literacy among acute stroke survivors. Future studies are needed to assess the use of technology and digital media to support widespread access and participation in video-based health literacy interventions for populations with acute and chronic stroke. Studies are needed to assess the impact of video-based educational interventions that are paired with stroke systems of care optimization to reduce the risk of stroke recurrence. Furthermore, studies on culturally and linguistically sensitive video-based stroke literacy interventions are needed to address known racial and ethnic disparities in stroke literacy. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1371/journal.pone.0171952.
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Acute hepatopancreatic necrosis disease (AHPND) is a contagious disease for the shrimp cultivation, thus early detection of disease is an unmet need. This present study documented for the first time a simple lateral flow immunoassay (LFIA) strip using polyclonal antibodies was created for the rapid detection both of PirAvp and PirBvp protein simultaneously. LFIA method based on the principle of sandwich format. The label is the colloidal gold. The polyclonal antibody was conjugated with the colloidal gold acting as biorecognition element and coated onto the conjugate pad. The rabbit anti-Pirvp, anti-PirBvp antibodies, and goat anti-rabbit IgG antibody were separately sprayed onto a nitrocellulose membrane to form two test lines and one control line, respectively. The appearance of red bands at the control line and the test line indicated a positive result. A single coloured band at control area indicated a negative result. The limit of detection of LFIA was found to be 125 ng, which could be visually detected by naked eye within 15 min. There was no cross-reactivity observed with VPnon-AHPND. Furthermore, the sensitivity and specificity of LFIA were 94.0% and 98.0%, respectively. The developed test strip could be a game changer for early and in situ diagnosis of AHPND.
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Schwannomas are benign nerve sheath tumors that are generally encapsulated and commonly detected in the head, neck, and mediastinal regions. Schwannomas localizing in the pelvis are extremely rare and tend to be asymptomatic initially due to slow growth rate. Schwannomas may be misdiagnosed as urologic or gynecologic tumors. Pelvic schwannomas are typically solitary, large, and well-circumscribed masses in the retroperitoneum or presacral areas. Other imaging characteristics are cystic degeneration, repeated hemorrhages, and calcifications. Calcification patterns can be punctate, speckled, curvilinear, or along the walls of the masses. We report a young man with a pelvic schwannoma with typical imaging features.
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Lesiones Traumáticas del Encéfalo , Grupos Raciales , Australia , Humanos , Pueblos IndígenasRESUMEN
Background: Case-based surveillance of antimicrobial resistance (AMR) provides more actionable data than isolate- or sample-based surveillance. We developed A Clinically Oriented antimicrobial Resistance surveillance Network (ACORN) as a lightweight but comprehensive platform, in which we combine clinical data collection with diagnostic stewardship, microbiological data collection and visualisation of the linked clinical-microbiology dataset. Data are compatible with WHO GLASS surveillance and can be stratified by syndrome and other metadata. Summary metrics can be visualised and fed back directly for clinical decision-making and to inform local treatment guidelines and national policy. Methods: An ACORN pilot was implemented in three hospitals in Southeast Asia (1 paediatric, 2 general) to collect clinical and microbiological data from patients with community- or hospital-acquired pneumonia, sepsis, or meningitis. The implementation package included tools to capture site and laboratory capacity information, guidelines on diagnostic stewardship, and a web-based data visualisation and analysis platform. Results: Between December 2019 and October 2020, 2294 patients were enrolled with 2464 discrete infection episodes (1786 community-acquired, 518 healthcare-associated and 160 hospital-acquired). Overall, 28-day mortality was 8.7%. Third generation cephalosporin resistance was identified in 54.2% (39/72) of E. coli and 38.7% (12/31) of K. pneumoniae isolates . Almost a quarter of S. aureus isolates were methicillin resistant (23.0%, 14/61). 290/2464 episodes could be linked to a pathogen, highlighting the level of enrolment required to achieve an acceptable volume of isolate data. However, the combination with clinical metadata allowed for more nuanced interpretation and immediate feedback of results. Conclusions: ACORN was technically feasible to implement and acceptable at site level. With minor changes from lessons learned during the pilot ACORN is now being scaled up and implemented in 15 hospitals in 9 low- and middle-income countries to generate sufficient case-based data to determine incidence, outcomes, and susceptibility of target pathogens among patients with infectious syndromes.
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Cancer carries stigma, taboos, and shame including, for diverse communities, who can have difficulty understanding and communicating about family health history genetic cancer screening (GCS). The Oregon Health Authority ScreenWise Program reached out to our academic-community research team to explore Asians and Micronesian Islanders (MI) perceptions on public health education outreach on GCS due to having previously only worked with the Latinx community. The purpose of the qualitative description pilot study was to elicit perceptions, beliefs, experiences, and recommendations from Asian and MI community leaders and community members regarding family health history GCS outreach in communities. Twenty Asians (Chinese and Vietnamese) and Micronesian Islanders (Chuukese and Marshallese) were recruited from the US Pacific Northwest. Nineteen participants are immigrants with an average 21.4 and 18.5 years having lived in the USA, respectively. Individual in-depth interviews were conducted using a semi-structured, open-ended interview guide and analyzed using conventional content analysis. Three main transcultural themes were identified: (1) degree of knowing and understanding cancer screening versus family health history GCS, (2) needing culturally relevant outreach messaging on family health history GCS, and (3) communication and decision-making regarding discussing with family and health care providers about cancer screening and GCS. Culturally relevant messaging rather than generic messaging is needed for inclusive outreach. Healthcare providers are encouraged to assess a client's family health history routinely because Asian and MI clients may not understand the information requested, may be hesitant to offer, or unable to provide information about their personal or family history of cancer.
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Detección Precoz del Cáncer , Neoplasias , Pueblo Asiatico , Relaciones Comunidad-Institución , Humanos , Nativos de Hawái y Otras Islas del Pacífico , Neoplasias/diagnóstico , Neoplasias/genética , Proyectos PilotoRESUMEN
BACKGROUND: Acute hepatopancreatic necrosis disease (AHPND) is caused by toxin-producing strains of Vibrio parahaemolyticus which contain deadly binary toxins PirAvp and PirBvp encoded in pVA1 plasmid. The polyclonal antibodies against PirBvp protein could be used to develop immunochromatographic test strip for in-field diagnosis of AHPND. RESULTS: In this study, PirBvp gene was amplified, cloned, and expressed in E. coli. The expressed protein was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot probed with 6xHis antibodies. Then, the recombinant PirBvp (rPirBvp) was purified using Ni-Sepharose column. Rabbits were immunized with the purified rPirBvp, and produced antibodies were analyzed using Ouchterlony double immunodiffusion. The antibody titration and antibody purification were performed by ELISA and affinity chromatography, respectively. Finally, antibody specificity and sensitivity were evaluated by dot blotting. The present study showed a high titer of polyclonal antibodies in rabbit serum after immunization and the titer increased steadily during the immunization schedule. The highest titer of antibody reached up to 2,560,000 with LOD of 0.1 ng/mL. The purified antibodies showed no cross-reactivity with proteins from other Vibrio species, and the detection threshold ranged from 6.25 to 12.5 ng toxin/dot. CONCLUSION: This study highlights the production of high titer and specific polyclonal antibodies as an initial material towards the development of lateral-flow strip test.
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BACKGROUND: Genetic factors increase the risk of type 2 diabetes mellitus (T2DM). Thus, family history status may be a useful public health tool for disease prevention. This study compared the nutritional status, knowledge level, and T2DM risk among young adults with and without a family history of diabetes in Malaysia. METHODS: A total of 288 university students aged 18 to 29 years participated in this comparative cross-sectional study. We assessed dietary intake, level of physical activity, knowledge of diabetes and T2DM risk. RESULTS: Respondents with a family history of diabetes had significantly higher weight (P = 0.003), body mass index (P < 0.001), waist circumference (P < 0.001), diabetes knowledge level (P < 0.005) and T2DM risk (P < 0.001). Ethnicity, fibre intake, T2DM risk score and knowledge about diabetes were significant contributors toward family history of diabetes (P = 0.025, 0.034, < 0.001 and 0.004, respectively). CONCLUSION: Young adults with a family history of diabetes had suboptimal nutritional status. Despite being more knowledgeable about diabetes, they did not practice a healthy lifestyle. Family history status can be used to screen young adults at the risk of developing T2DM for primary disease prevention.
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Acute Hepatopancreatic Necrosis Disease (AHPND) is a newly emerging shrimp disease with mortality up to 100 percent caused by Vibrio parahaemolyticus which carries a plasmid encoding for two toxins, ToxA and ToxB. In 2013, the Global Aquaculture Alliance (GAA) estimated shrimp farming decline in Asia accounted for 1-billion US dollar lost. Currently, diagnosis using PCR method does not meet the demand of in situ detection, which is based on antigen-antibody interaction, has not been developed yet. In this present study, we proceeded to create the toxin and its antibody for lateral flow development. First, recombinant toxin ToxA was generated by gene manipulation. After that, purified ToxA was used to immunize rabbits. Finally, antisera from rabbits and protein-A purified antibodies were evaluated for titer, specificity, and detection threshold. Results showed that recombinant ToxA was overexpressed in soluble fraction at 37oC with 1mM IPTG. Purification by affinity chromatography was able to isolate recombinant ToxA with the purity up to 94.49%. In ELISA experiment, the immunized antisera reached a titer of up to 1/5,210,000 with 1µg/ml of antigen, and detection threshold was 100ng recombinant toxin. After purification, the detection threshold of purified polyclonal antibodies was 25ng toxin per dot. These results laid a groundwork for the development of AHPND detection kit based on antigen - antibody interactions.
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Listeria monocytogenes has caused outbreaks of foodborne illness from apples in the USA, and is also a major issue for regulatory compliance worldwide. Due to apple's significance as an important export product from New Zealand, we aimed to determine the effect of long-term, low-temperature sea-freight from New Zealand to the USA (July) and Europe (March-April), two key New Zealand markets, on the survival and/or growth of L. monocytogenes on fresh apples. Temperature and humidity values were recorded during a shipment to each market (USA and Europe), then the observed variations around the 0.5 °C target temperature were simulated in laboratory trials using open ('Scired') and closed ('Royal Gala' for the USA and 'Cripps Pink' for Europe) calyx cultivars of apples inoculated with a cocktail of 107-108 cells of seven strains of L. monocytogenes. Samples were analysed for L. monocytogenes quantification at various intervals during the simulation and on each occasion, an extra set was analysed after a subsequent 8 days at 20 °C. When both the sea-freight simulations concluded, L. monocytogenes showed 5 log reductions on the equatorial surface of skin of apples, but only about 2.5 log reduction for USA and about 3.3 log reduction for Europe in the calyx. Cultivar type had no significant effect on the survival of L. monocytogenes for both sea-freight simulations, either in the calyx or on the skin (P > 0.05). Most of the reduction in the culturable cells on the skin occurred during the initial 2 weeks of the long-term storage simulations. There was also no significant difference in the reduction of L. monocytogenes at 0.5 or 20 °C. No correlation was observed between firmness or total soluble solids and survival of L. monocytogenes. Because the inoculated bacterial log reduction was lower in the calyx than on the skin, it is speculated that the risk of causing illness is higher if contaminated apple cores are eaten. The result suggested that the international sea-freight transportation does not result in the growth of L. monocytogenes irrespective of time and temperature. The results of this study provide useful insights into the survival of L. monocytogenes on different apple cultivars that can be used to develop effective risk mitigation strategies for fresh apples during long-term, low-temperature international sea-freight transportation.
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Manipulación de Alimentos/métodos , Listeria monocytogenes/aislamiento & purificación , Malus/microbiología , Refrigeración/métodos , Carga Bacteriana , Frío , Recuento de Colonia Microbiana , Europa (Continente) , Microbiología de Alimentos/métodos , Enfermedades Transmitidas por los Alimentos/microbiología , Enfermedades Transmitidas por los Alimentos/prevención & control , Nueva ZelandaRESUMEN
Escherichia coli O157:H7 risk associated with the consumption of fresh cut-cos lettuce during Australian industrial practices was assessed. A probabilistic risk assessment model was developed and implemented in the @Risk software by using the Monte Carlo simulation technique with 1,000,000 iterations. Australian preharvest practices yielded predicted annual mean E. coli O157:H7 levels from 0.2 to -3.4 log CFU/g and prevalence values ranged from 2 to 6.4%. While exclusion of solar radiation from the baseline model yielded a significant increase in concentration of E. coli O157:H7 (-5.2 -log fold), drip irrigation usage, exclusion of manure amended soil and rainfall reduced E. coli O157:H7 levels by 7.4, 6.5, and 4.3-log fold, respectively. The microbial quality of irrigation water and irrigation type both had a significant effect on E. coli O157:H7 concentrations at harvest (p < 0.05). The probability of illness due to consumption of E. coli O157:H7 contaminated fresh cut-cos lettuce when water washing interventions were introduced into the processing module, was reduced by 1.4-2.7-log fold (p < 0.05). This study provides a robust basis for assessment of risk associated with E. coli O157:H7 contamination on fresh cut-cos lettuce for industrial practices and will assist the leafy green industry and food safety authorities in Australia to identify potential risk management strategies.