Second-generation antipsychotic quetiapine blocks voltage-dependent potassium channels in coronary arterial smooth muscle cells.

Voltage-dependent K+ (Kv) channels play an important role in restoring the membrane potential to its resting state, thereby maintaining vascular tone. In this study, native smooth muscle cells from rabbit coronary arteries were used to investigate the inhibitory effect of quetiapine, an atypical antipsychotic agent, on Kv channels. Quetiapine showed a concentration-dependent inhibition of Kv channels, with an IC50 of 47.98 ± 9.46 µM. Although quetiapine (50 µM) did not alter the steady-state activation curve, it caused a negative shift in the steady-state inactivation curve. The application of 1 and 2 Hz train steps in the presence of quetiapine significantly increased the inhibition of Kv current. Moreover, the recovery time constants from inactivation were prolonged in the presence of quetiapine, suggesting that its inhibitory action on Kv channels is use (state)-dependent. The inhibitory effects of quetiapine were not significantly affected by pretreatment with Kv1.5, Kv2.1, and Kv7 subtype inhibitors. Based on these findings, we conclude that quetiapine inhibits Kv channels in both a concentration- and use (state)-dependent manner. Given the physiological significance of Kv channels, caution is advised in the use of quetiapine as an antipsychotic due to its potential side effects on cardiovascular Kv channels.

Drug Repositioning via Graph Neural Networks: Identifying Novel JAK2 Inhibitors from FDA-Approved Drugs through Molecular Docking and Biological Validation.

The increasing utilization of artificial intelligence algorithms in drug development has proven to be highly efficient and effective. One area where deep learning-based approaches have made significant contributions is in drug repositioning, enabling the identification of new therapeutic applications for existing drugs. In the present study, a trained deep-learning model was employed to screen a library of FDA-approved drugs to discover novel inhibitors targeting JAK2. To accomplish this, reference datasets containing active and decoy compounds specific to JAK2 were obtained from the DUD-E database. RDKit, a cheminformatic toolkit, was utilized to extract molecular features from the compounds. The DeepChem framework's GraphConvMol, based on graph convolutional network models, was applied to build a predictive model using the DUD-E datasets. Subsequently, the trained deep-learning model was used to predict the JAK2 inhibitory potential of FDA-approved drugs. Based on these predictions, ribociclib, topiroxostat, amodiaquine, and gefitinib were identified as potential JAK2 inhibitors. Notably, several known JAK2 inhibitors demonstrated high potential according to the prediction results, validating the reliability of our prediction model. To further validate these findings and confirm their JAK2 inhibitory activity, molecular docking experiments were conducted using tofacitinib-an FDA-approved drug for JAK2 inhibition. Experimental validation successfully confirmed our computational analysis results by demonstrating that these novel drugs exhibited comparable inhibitory activity against JAK2 compared to tofacitinib. In conclusion, our study highlights how deep learning models can significantly enhance virtual screening efforts in drug discovery by efficiently identifying potential candidates for specific targets such as JAK2. These newly discovered drugs hold promises as novel JAK2 inhibitors deserving further exploration and investigation.

A systematic review of the use of in-vehicle telematics in monitoring driving behaviours.

BACKGROUND: Road traffic deaths are increasing globally, and preventable driving behaviours are a significant cause of these deaths. In-vehicle telematics has been seen as technology that can improve driving behaviour. The technology has been adopted by many insurance companies to track the behaviours of their consumers. This systematic review presents a summary of the ways that in-vehicle telematics has been modelled and analysed. METHODOLOGY: Electronic searches were conducted on Scopus and Web of Science. Studies were only included if they had a sample size of 10 or more participants, collected their data over at least multiple days, and were published during or after 2010. 45 relevant papers were included in the review. 27 of these articles received a rating of "good" in the quality assessment. RESULTS: We found a divide in the literature regarding the use of in-vehicle telematics. Some articles were interested in the utility of in-vehicle telematics for insurance purposes, while others were interested in determining the influence that in-vehicle telematics has on driving behaviour. Machine learning analyses were the most common forms of analysis seen throughout the review, being especially common in articles with insurance-based outcomes. Acceleration, braking, and speed were the most common variables identified in the review. CONCLUSION: We recommend that future studies provide the demographical information of their sample so that the influence of in-vehicle telematics on the driving behaviours of different groups can be understood. It is also recommended that future studies use multi-level models to account for the hierarchical structure of the telematics data. This hierarchical structure refers to the individual trips for each driver.

Biocompatibility and sub-chronic toxicity studies of phlorotannin/polycaprolactone coated trachea tube for advancing medical device applications.

The phlorotannin-polycaprolactone-coated endotracheal tube (PP tube) has been developed with the aim of preventing tracheal stenosis that can result from endotracheal intubation, a factor that can lead to a serious airway obstruction. Its preventive efficacy has been assessed through both in vitro and in vivo investigations. However, there is a lack of studies concerning its biocompatibility and sub-chronic toxicity in animal models, a crucial factor to ensure the safety of its usage as a functional endotracheal tube. Thus, this study aimed to evaluate the biocompatibility and sub-chronic (13 weeks) toxicity of the PP tube through L929 cell line and diverse in vivo models. The cytotoxicity testing was performed using the extracts of PP tube on L929 cells for 72 h. Furthermore, other tests conducted on animal models, including ICR mice (acute systemic toxicity), New Zealand white rabbit (intradermal reactivity and pyrogen tests), guinea pig (maximization sensitization), and Sprague Dawley rats (sub-chronic toxicity). In both biocompatibility and sub-chronic toxicity analyses, no significant adverse effects are observed in the groups exposed to the PP tube, when compared to control group. Altogether, the findings suggested that the PP tube exhibits relative non-toxic and safety, supporting its suitability for clinical usage. However, extended periods of intubation may produce mild irritant responses, highlighting the clinical caution of limiting intubation duration to less than 13 weeks.

Trends in blood pressure changes and hypertension prevalence in Australian adults before and during the COVID-19 pandemic.

Efforts to limit the impact of the coronavirus disease (COVID-19) pandemic led to the implementation of public health measures and reallocation of health resources. To investigate trends in blood pressure (BP), hypertension and BMI in the Australian population during the COVID-19 pandemic, data from publicly accessible health stations were analyzed. Average BP and BMI measured by the SiSU Health Station network in Australia in over 1.6 million health screenings were compared between the years 2018 and 2021. Additionally, paired trajectories for BP and BMI development before and during the COVID-19 pandemic were calculated. Comparisons between pre-COVID years and post-COVID years of 2018 versus 2020, 2019 versus 2020, 2018 versus 2021, and 2019 versus 2021 showed increases in average adjusted systolic BP of 2.0, 1.7, 2.6, and 2.3 mmHg, respectively. Paired analysis of longitudinal data showed an overall increase in the trajectory of systolic BP of 3.2 mmHg between pre- and post-COVID years. The prevalence of hypertension in users of the health stations increased by approximately 25% in the years 2020-2021. Similar trends were seen for BMI. Data from public Australian health stations indicated a strong trend toward higher BP during the COVID-19 pandemic. At the population level, BP increments have been shown to markedly increase cardiovascular disease risk. Anti-pandemic measures need to be carefully evaluated in terms of secondary public health effects and health support systems extended to effectively target cardiovascular risk.

Inhibition of voltage-gated potassium channel by aripiprazole in rabbit coronary arterial smooth muscle cells.

Aripiprazole, a third-generation antipsychotic, has been widely used to treat schizophrenia. In this study, we evaluated the effect of aripiprazole on voltage-gated potassium (Kv) channels in rabbit coronary arterial smooth muscle cells using the patch clamp technique. Aripiprazole reduced the Kv current in a concentration-dependent manner with a half-maximal inhibitory concentration of 0.89 ± 0.20 µM and a Hill coefficient of 1.30 ± 0.25. The inhibitory effect of aripiprazole on Kv channels was voltage-dependent, and an additional aripiprazole-induced decrease in the Kv current was observed in the voltage range of full channel activation. The decay rate of Kv channel inactivation was accelerated by aripiprazole. Aripiprazole shifted the steady-state activation curve to the right and the inactivation curve to the left. Application of a repetitive train of pulses (1 and 2 Hz) promoted inhibition of the Kv current by aripiprazole. Furthermore, the recovery time constant from inactivation increased in the presence of aripiprazole. Pretreatment of Kv1.5 subtype inhibitor reduced the inhibitory effect of aripiprazole. However, pretreatment with Kv 7 and Kv2.1 subtype inhibitors did not change the degree of aripiprazole-induced inhibition of the Kv current. We conclude that aripiprazole inhibits Kv channels in a concentration-, voltage-, time-, and use (state)-dependent manner by affecting the gating properties of the channels.

Multifunctional hydrogel dressing based on fish gelatin/oxidized hyaluronate for promoting diabetic wound healing.

Non-healing chronic diabetic wound treatment remains an unsolved healthcare challenge and still threatens patients' lives. Recently, hydrogel dressings based on natural biomaterials have been widely investigated to accelerate the healing of diabetic wounds. In this study, we introduce a bioactive hydrogel based on fish gelatin (FG) as a candidate for diabetic wound treatments, which is a recently emerged substitute for mammalian derived gelatin. The composite hydrogel simply fabricated with FG and oxidized hyaluronate (OHy) through Schiff base reaction could successfully accelerate wound healing due to their adequate mechanical stability and self-healing ability. In vitro studies showed that the fabricated hydrogels exhibited cytocompatibility and could reduce pro-inflammatory cytokine expression such as NO, IL-1ß, TNF-α, and PGE2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. In addition, the production of reactive oxygen species (ROS), a key marker of free radicals producing oxidative stress, was also reduced by fabricated hydrogels. Furthermore, in vivo experiments demonstrated that the hydrogel could promote wound closure, re-epithelialization, collagen deposition, and protein expression of CD31, CD206, and Arg1 in diabetic mice models. Our study highlights the advanced potential of FG as a promising alternative material and indicates that FOHI can be successfully used for diabetic wound healing applications.

The antidiabetic drug ipragliflozin induces vasorelaxation of rabbit femoral artery by activating a Kv channel, the SERCA pump, and the PKA signaling pathway.

We explored the vasorelaxant effects of ipragliflozin, a sodium-glucose cotransporter-2 inhibitor, on rabbit femoral arterial rings. Ipragliflozin relaxed phenylephrine-induced pre-contracted rings in a dose-dependent manner. Pre-treatment with the ATP-sensitive K+ channel inhibitor glibenclamide (10 µM), the inwardly rectifying K+ channel inhibitor Ba2+ (50 µM), or the Ca2+-sensitive K+ channel inhibitor paxilline (10 µM) did not influence the vasorelaxant effect. However, the voltage-dependent K+ (Kv) channel inhibitor 4-aminopyridine (3 mM) reduced the vasorelaxant effect. Specifically, the vasorelaxant response to ipragliflozin was significantly attenuated by pretreatment with the Kv7.X channel inhibitors linopirdine (10 µM) and XE991 (10 µM), the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) pump inhibitors thapsigargin (1 µM) and cyclopiazonic acid (10 µM), and the cAMP/protein kinase A (PKA)-associated signaling pathway inhibitors SQ22536 (50 µM) and KT5720 (1 µM). Neither the cGMP/protein kinase G (PKG)-associated signaling pathway nor the endothelium was involved in ipragliflozin-induced vasorelaxation. We conclude that ipragliflozin induced vasorelaxation of rabbit femoral arteries by activating Kv channels (principally the Kv7.X channel), the SERCA pump, and the cAMP/PKA-associated signaling pathway independent of other K+ (ATP-sensitive K+, inwardly rectifying K+, and Ca2+-sensitive K+) channels, cGMP/PKG-associated signaling, and the endothelium.

Vasorelaxant mechanisms of the antidiabetic anagliptin in rabbit aorta: roles of Kv channels and SERCA pump.

AIMS: The present study investigated the vasorelaxant mechanisms of an oral antidiabetic drug, anagliptin, using phenylephrine (Phe)-induced pre-contracted rabbit aortic rings. METHODS: Arterial tone measurement was performed in rabbit thoracic aortic rings. RESULTS: Anagliptin induced vasorelaxation in a dose-dependent manner. Pre-treatment with the classical voltagedependent K+ (Kv) channel inhibitors 4-aminopyridine and tetraethylammonium significantly decreased the vasorelaxant effect of anagliptin, whereas pre-treatment with the inwardly rectifying K+ (Kir) channel inhibitor Ba2+, the ATP-sensitive K+ (KATP) channel inhibitor glibenclamide, and the large-conductance Ca2+-activated K+ (BKCa) channel inhibitor paxilline did not attenuate the vasorelaxant effect. Furthermore, the vasorelaxant response of anagliptin was effectively inhibited by pre-treatment with the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump inhibitors thapsigargin and cyclopiazonic acid. Neither cAMP/protein kinase A (PKA)-related signaling pathway inhibitors (adenylyl cyclase inhibitor SQ 22536 and PKA inhibitor KT 5720) nor cGMP/protein kinase G (PKG)-related signaling pathway inhibitors (guanylyl cyclase inhibitor ODQ and PKG inhibitor KT 5823) reduced the vasorelaxant effect of anagliptin. Similarly, the anagliptin-induced vasorelaxation was independent of the endothelium. CONCLUSIONS: Based on these results, we suggest that anagliptin-induced vasorelaxation in rabbit aortic smooth muscle occurs by activating Kv channels and the SERCA pump, independent of other vascular K+ channels, cAMP/PKA- or cGMP/PKG-related signaling pathways, and the endothelium.

Characterization of merozoite-specific thrombospondin-related anonymous protein (MTRAP) in Plasmodium vivax and P. knowlesi parasites.

Plasmodium vivax, the most widespread human malaria parasite, and P. knowlesi, an emerging Plasmodium that infects humans, are the phylogenetically closest malarial species that infect humans, which may induce cross-species reactivity across most co-endemic areas in Southeast Asia. The thrombospondin-related anonymous protein (TRAP) family is indispensable for motility and host cell invasion in the growth and development of Plasmodium parasites. The merozoite-specific TRAP (MTRAP), expressed in blood-stage merozoites, is supposed to be essential for human erythrocyte invasion. We aimed to characterize MTRAPs in blood-stage P. vivax and P. knowlesi parasites and ascertain their cross-species immunoreactivity. Recombinant P. vivax and P. knowlesi MTRAPs of full-length ectodomains were expressed in a mammalian expression system. The MTRAP-specific immunoglobulin G, obtained from immune animals, was used in an immunofluorescence assay for subcellular localization and invasion inhibitory activity in blood-stage parasites was determined. The cross-species humoral immune responses were analyzed in the sera of patients with P. vivax or P. knowlesi infections. The MTRAPs of P. vivax (PvMTRAP) and P. knowlesi (PkMTRAP) were localized on the rhoptry body of merozoites in blood-stage parasites. Both anti-PvMTRAP and anti-PkMTRAP antibodies inhibited erythrocyte invasion of blood-stage P. knowlesi parasites. The humoral immune response to PvMTRAP showed high immunogenicity, longevity, and cross-species immunoreactivity with P. knowlesi. MTRAPs are promising candidates for development of vaccines and therapeutics against vivax and knowlesi malaria.

Enhancing malaria detection in resource-limited areas: A high-performance colorimetric LAMP assay for Plasmodium falciparum screening.

Malaria eradication efforts in resource-limited areas require a rapid, economical, and accurate tool for detecting of the low parasitemia. The malaria rapid diagnostic test (mRDT) is the most suitable for on-site detection of the deadliest form of malaria, Plasmodium falciparum. However, the deletions of histidine rich protein 2 and 3 genes are known to compromise the effectiveness of mRDT. One of the approaches that have been explored intensively for on-site diagnostics is the loop-mediated isothermal amplification (LAMP). LAMP is a one-step amplification that allows the detection of Plasmodium species in less than an hour. Thus, this study aims to present a new primer set to enhance the performance of a colorimetric LAMP (cLAMP) for field application. The primer binding regions were selected within the A-type of P. falciparum 18S rRNA genes, which presents a dual gene locus in the genome. The test result of the newly designed primer indicates that the optimal reaction condition for cLAMP was 30 minutes incubation at 65°C, a shorter incubation time compared to previous LAMP detection methods that typically takes 45 to 60 minutes. The limit of detection (LoD) for the cLAMP using our designed primers and laboratory-grown P. falciparum (3D7) was estimated to be 0.21 parasites/µL which was 1,000-fold higher than referencing primers. Under optimal reaction condition, the new primer sets showed the sensitivity (100%, 95% CI: 80.49-100%) and specificity (100%, 95% CI: 94.64-100%) with 100% (95% CI: 95.70-100%) accuracy on the detection of dried blood spots from Malawi (n = 84). Briefly, the newly designed primer set for P. falciparum detection exhibited high sensitivity and specificity compared to referenced primers. One great advantage of this tool is its ability to be detected by the naked eye, enhancing field approaches. Thus, this tool has the potential to be effective for accurate early parasite detection in resource-limited endemic areas.

Merozoite surface protein 1 paralog is involved in the human erythrocyte invasion of a zoonotic malaria, Plasmodium knowlesi.

The zoonotic malaria parasite Plasmodium knowlesi is an important public health concern in Southeast Asia. Invasion of host erythrocytes is essential for parasite growth, and thus, understanding the repertoire of parasite proteins that enable this process is vital for identifying vaccine candidates and how some species are able to cause zoonotic infection. Merozoite surface protein 1 (MSP1) is found in all malaria parasite species and is perhaps the most well-studied as a potential vaccine candidate. While MSP1 is encoded by a single gene in P. falciparum, all other human infective species (P. vivax, P. knowlesi, P. ovale, and P. malariae) additionally encode a divergent paralogue known as MSP1P, and little is known about its role or potential functional redundancy with MSP1. We, therefore, studied the function of P. knowlesi merozoite surface protein 1 paralog (PkMSP1P), using both recombinant protein and CRISPR-Cas9 genome editing. The recombinant 19-kDa C-terminus of PkMSP1P (PkMSP1P-19) was shown to bind specifically to human reticulocytes. However, immunoblotting data suggested that PkMSP1P-19-induced antibodies can recognize PkMSP1-19 and vice versa, confounding our ability to separate the properties of these two proteins. Targeted disruption of the pkmsp1p gene profoundly impacts parasite growth, demonstrating for the first time that PkMSP1P is important in in vitro growth of P. knowlesi and likely plays a distinct role from PkMSP1. Importantly, the MSP1P KO also enabled functional characterization of the PkMSP1P-19 antibodies, revealing clear immune cross-reactivity between the two paralogues, highlighting the vital importance of genetic studies in contextualizing recombinant protein studies.

CD40 Agonists Alter the Pancreatic Cancer Microenvironment by Shifting the Macrophage Phenotype toward M1 and Suppress Human Pancreatic Cancer in Organotypic Slice Cultures

Background/Aims@#CD40 agonists are thought to generate antitumor effects on pancreatic cancer via macrophages and T cells. We aimed to investigate the role of CD40 agonists in the differentiation of macrophages and treatment of human pancreatic adenocarcinoma. @*Methods@#Immunohistochemistry was performed on paraffin-embedded surgical blocks from patients with pancreatic cancers to evaluate macrophage phenotypes and their relationship with survival. The effects of CD40 agonists on macrophage phenotypes and human pancreatic cancer were evaluated utilizing cell cocultures and organotypic slice cultures. @*Results@#CD163 + (predominant in M2 macrophages) and FOXP3 + (predominant in regulatory T cells) expression levels in the tumors were significantly lower in patients with stage IB pancreatic cancer than in those with stage II or III disease (p=0.002 and p=0.003, respectively). Patients with high CD163 + expression had shorter overall survival than those with low CD163 + expression (p=0.002). In vitro treatment of THP-1 macrophages with a CD40 agonist led to an increase in HLA-DR + (predominant in M1 macrophages) and a decrease in CD163 + expression in THP-1 cells. Cell cocultures showed that CD40 agonists facilitate the suppression of PANC-1 human pancreatic cancer cells by THP-1 macrophages. Organotypic slice cultures showed that CD40 agonists alter the pancreatic cancer microenvironment by shifting the macrophage phenotype toward M1 (increase HLA-DR + and decrease CD163 + expression), decreasing the abundance of regulatory T cells, and increasing tumor cell apoptosis. @*Conclusions@#CD163 is related to advanced human pancreatic cancer stages and shorter overall survival. CD40 agonists alter macrophage phenotype polarization to favor the M1 phenotype and suppress human pancreatic cancer.

Inhibitory effects of the atypical antipsychotic, clozapine, on voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells

To investigate the adverse effects of clozapine on cardiovascular ion channels, we examined the inhibitory effect of clozapine on voltage-dependent K+(Kv) channels in rabbit coronary arterial smooth muscle cells. Clozapine-induced inhibition of Kv channels occurred in a concentration-dependent manner with an halfinhibitory concentration value of 7.84 ± 4.86 µM and a Hill coefficient of 0.47 ± 0.06.Clozapine did not shift the steady-state activation or inactivation curves, suggesting that it inhibited Kv channels regardless of gating properties. Application of train pulses (1 and 2 Hz) progressively augmented the clozapine-induced inhibition of Kv channels in the presence of the drug. Furthermore, the recovery time constant from inactivation was increased in the presence of clozapine, suggesting that clozapineinduced inhibition of Kv channels is use (state)-dependent. Pretreatment of a Kv1.5 subtype inhibitor decreased the Kv current amplitudes, but additional application of clozapine did not further inhibit the Kv current. Pretreatment with Kv2.1 or Kv7 subtype inhibitors partially blocked the inhibitory effect of clozapine. Based on these results, we conclude that clozapine inhibits arterial Kv channels in a concentrationand use (state)-dependent manner. Kv1.5 is the major subtype involved in clozapineinduced inhibition of Kv channels, and Kv2.1 and Kv7 subtypes are partially involved.

Performance Evaluation of Biozentech Malaria Scanner in Plasmodium knowlesi and P. falciparum as a New Diagnostic Tool

The computer vision diagnostic approach currently generates several malaria diagnostic tools. It enhances the accessible and straightforward diagnostics that necessary for clinics and health centers in malaria-endemic areas. A new computer malaria diagnostics tool called the malaria scanner was used to investigate living malaria parasites with easy sample preparation, fast and user-friendly. The cultured Plasmodium parasites were used to confirm the sensitivity of this technique then compared to fluorescence-activated cell sorting (FACS) analysis and light microscopic examination. The measured percentage of parasitemia by the malaria scanner revealed higher precision than microscopy and was similar to FACS. The coefficients of variation of this technique were 1.2-6.7% for Plasmodium knowlesi and 0.3-4.8% for P. falciparum. It allowed determining parasitemia levels of 0.1% or higher, with coefficient of variation smaller than 10%. In terms of the precision range of parasitemia, both high and low ranges showed similar precision results. Pearson’s correlation test was used to evaluate the correlation data coming from all methods. A strong correlation of measured parasitemia (r2=0.99, P<0.05) was observed between each method. The parasitemia analysis using this new diagnostic tool needs technical improvement, particularly in the differentiation of malaria species.

Performance Evaluation of Biozentech Malaria Scanner in Plasmodium knowlesi and P. falciparum as a New Diagnostic Tool

The computer vision diagnostic approach currently generates several malaria diagnostic tools. It enhances the accessible and straightforward diagnostics that necessary for clinics and health centers in malaria-endemic areas. A new computer malaria diagnostics tool called the malaria scanner was used to investigate living malaria parasites with easy sample preparation, fast and user-friendly. The cultured Plasmodium parasites were used to confirm the sensitivity of this technique then compared to fluorescence-activated cell sorting (FACS) analysis and light microscopic examination. The measured percentage of parasitemia by the malaria scanner revealed higher precision than microscopy and was similar to FACS. The coefficients of variation of this technique were 1.2-6.7% for Plasmodium knowlesi and 0.3-4.8% for P. falciparum. It allowed determining parasitemia levels of 0.1% or higher, with coefficient of variation smaller than 10%. In terms of the precision range of parasitemia, both high and low ranges showed similar precision results. Pearson’s correlation test was used to evaluate the correlation data coming from all methods. A strong correlation of measured parasitemia (r2=0.99, P<0.05) was observed between each method. The parasitemia analysis using this new diagnostic tool needs technical improvement, particularly in the differentiation of malaria species.

Surveillance on the Vivax Malaria in Endemic Areas in the Republic of Korea Based on Molecular and Serological Analyses

Plasmodium vivax reemerged in 1993. It has been sustained for more than 25 years and become one of the important indigenous parasitic diseases in northern and western parts of the Republic of Korea near the demilitarized zone. In particular, relapse is a significant concern for the control of malaria, as short- and long-term incubation periods vary among those infected in Korea. In this study, the prevalence of asymptomatic carriers was examined among residents of high endemic areas of vivax malaria during nonseasonal transmission of mosquitoes. Blood samples from 3 endemic regions in northwestern Korea were evaluated by microscopic examination, rapid diagnostic testing, and nested PCR to identify asymptomatic patients carrying malaria parasites in the community. However, no positive malaria case among residents of endemic areas was detected. Additionally, serological analysis was carried out to measure antibodies against 3 antigenic recombinant proteins of P. vivax, merozoite surface protein 1-19, circumsporozoite surface protein-VK210, and liver-stage antigen (PvLSA-N), by the protein array method. Interestingly, seropositivity of sera between previous exposure and samples without exposure to malaria was significantly higher using the PvLSA-N antigen than the other antigens, suggesting that PvLSA-N can be used as a serological marker to analyze the degree of exposure for malaria transmission in endemic areas. This indicates a very low asymptomatic carrier prevalence during the nonmalaria season in the endemic areas of Korea.

Surveillance on the Vivax Malaria in Endemic Areas in the Republic of Korea Based on Molecular and Serological Analyses

Plasmodium vivax reemerged in 1993. It has been sustained for more than 25 years and become one of the important indigenous parasitic diseases in northern and western parts of the Republic of Korea near the demilitarized zone. In particular, relapse is a significant concern for the control of malaria, as short- and long-term incubation periods vary among those infected in Korea. In this study, the prevalence of asymptomatic carriers was examined among residents of high endemic areas of vivax malaria during nonseasonal transmission of mosquitoes. Blood samples from 3 endemic regions in northwestern Korea were evaluated by microscopic examination, rapid diagnostic testing, and nested PCR to identify asymptomatic patients carrying malaria parasites in the community. However, no positive malaria case among residents of endemic areas was detected. Additionally, serological analysis was carried out to measure antibodies against 3 antigenic recombinant proteins of P. vivax, merozoite surface protein 1-19, circumsporozoite surface protein-VK210, and liver-stage antigen (PvLSA-N), by the protein array method. Interestingly, seropositivity of sera between previous exposure and samples without exposure to malaria was significantly higher using the PvLSA-N antigen than the other antigens, suggesting that PvLSA-N can be used as a serological marker to analyze the degree of exposure for malaria transmission in endemic areas. This indicates a very low asymptomatic carrier prevalence during the nonmalaria season in the endemic areas of Korea.

Effects of Low-carbohydrate and High-fat Diet Supplemented with Ketogenic Drink on Cognitive Function and Physical Performance in the Elderly at High Risk for Dementia / 대한지역사회영양학회지

OBJECTIVES: Reduced glucose utilization in the main parts of the brain involved in memory is a major cause of Alzheimer's disease, in which ketone bodies are used as the only and effective alternative energy source of glucose. This study examined the effects of a low-carbohydrate and high-fat (LCHF) diet supplemented with a ketogenic nutrition drink on cognitive function and physical activity in the elderly at high risk for dementia.METHODS: The participants of this study were 28 healthy elderly aged 60-91 years showing a high risk factor of dementia or whose Korean Mini-Mental State Examination (K-MMSE) score was less than 24 points. Over 3 weeks, the case group was given an LCHF diet with nutrition drinks consisting of a ketone/non-ketone ratio of 1.73:1, whereas the control group consumed well-balanced nutrition drinks while maintaining a normal diet. After 3 weeks, K-MMSE, body composition, urine ketone bodies, and physical ability were all evaluated.RESULTS: Urine ketone bodies of all case group subjects were positive, and K-MMSE score was significantly elevated in the case group only (p=0.021). Weight and BMI were elevated in the control group only (p<0.05). Grip strength was elevated in all subjects (p<0.01), and measurements of gait speed and one leg balance were improved only in the case group (p<0.05).CONCLUSIONS: We suggest that adherence to the LCHF diet supplemented with a ketogenic drink could possibly influence cognitive and physical function in the elderly with a high risk factor for dementia. Further, we confirmed the applicability of this dietary intervention in the elderly based on its lack of any side effects or changes in nutritional status.

Perivascular Cells and NADPH Oxidase Inhibition Partially Restore Hyperglycemia-Induced Alterations in Hematopoietic Stem Cell and Myeloid-Derived Suppressor Cell Populations in the Bone Marrow

BACKGROUND AND OBJECTIVES: Patients suffer from long-term diabetes can result in severe complications in multiple organs through induction of vascular dysfunctions. However, the effects of chronic hyperglycemic conditions on hematopoiesis and the microenvironment in the bone marrow (BM) are not yet well understood. METHODS: BM cells were harvested from femurs of mice and analyzed using flow cytometry. Human PVCs were cultured in serum-free α-MEM. After 24hrs, PVC-CM was collected and filtered through a 0.22 μm filter. RESULTS: In this study, we showed that hyperglycemia alters hematopoietic composition in the BM, which can partially be restored via paracrine mechanisms, including perivascular cells (PVCs) and NADPH oxidase (NOX) inhibition in mice with streptozotocin-induced diabetes. Prolonged hyperglycemic conditions resulted in an increase in the frequency and number of long-term hematopoietic stem cells as well as the number of total BM cells. The altered hematopoiesis in the BM was partially recovered by treatment with PVC-derived conditioned medium (CM). Long-term diabetes also increased the number of myeloid-derived suppressor cells in the BM, which was partially restored by the administration of PVC-CM and diphenyleneiodonium (DPI), a NOX inhibitor. We further showed the downregulation of ERK and p38 phosphorylation in BM cells of diabetic mice treated with PVC-CM and DPI. This may be associated with dysfunction of hematopoietic cells and promotion of subsequent diabetic complications. CONCLUSIONS: Our data suggested that alterations in BM hematopoietic composition due to prolonged hyperglycemic conditions might be restored by improvement of the hematopoietic microenvironment and modulation of NOX activity.