The first epidemiology of urolithiasis in Northern Vietnam: Urinary stone composition, age, gender, season, and clinical features study.

OBJECTIVES: The aim of this study is to analyze the compositions of urinary stones and investigate their distributions in different ages, genders, seasons, and clinical features of Northern Vietnamese patients. METHODS: A total of 231 patients with urinary stones from Northern Vietnam were collected and analyzed composition from 1/2021-12/2022. For all patients, age, sex, stone location, stone side, urine pH, and hospitalized date (month) were collected. RESULTS: Kidney stones are more frequently found in men than women with the male: female urinary stones ratio in this study being 1.96:1. The highest stone prevalence appeared between 60 and 69 years old. The most common stone composition was calcium oxalate, followed by calcium phosphate, uric acid, struvite, and cysteine. Mix stones of CaOx and CaP were more prevalent than pure stones. Males submitted more CaOx, CaP, and UA stones, whereas females were susceptible to infectious stones. Stones were more frequently found on the left side of the upper urinary tract (51.9%) than on the right side (27.3%) and lower urinary tract (7.8%). Cultural tendency leads to a smaller number of stones during the Lunar new year (February), and Ghost month (August).

High Solubility and Bioavailability of Lobster Shell-Derived Calcium for Significantly Proliferating Bone and Skin Cells In Vitro.

Shell wastes pose environmental and financial burdens to the shellfish industry. Utilizing these undervalued shells for commercial chitin production could minimize their adverse impacts while maximizing economic value. Shell chitin conventionally produced through harsh chemical processes is environmentally unfriendly and infeasible for recovering compatible proteins and minerals for value-added products. However, we recently developed a microwave-intensified biorefinery that efficiently produced chitin, proteins/peptides, and minerals from lobster shells. Lobster minerals have a calcium-rich composition and biologically originated calcium is more biofunctional for use as a functional, dietary, or nutraceutical ingredient in many commercial products. This has suggested a further investigation of lobster minerals for commercial applications. In this study, the nutritional attributes, functional properties, nutraceutical effects, and cytotoxicity of lobster minerals were analyzed using in vitro simulated gastrointestinal digestion combined with growing bone (MG-63), skin (HaCaT), and macrophage (THP-1) cells. The calcium from the lobster minerals was found to be comparable to that of a commercial calcium supplement (CCS, 139 vs. 148 mg/g). In addition, beef incorporated with lobster minerals (2%, w/w) retained water better than that of casein and commercial calcium lactate (CCL, 21.1 vs. 15.1 and 13.3%), and the lobster mineral had a considerably higher oil binding capacity than its rivals (casein and CCL, 2.5 vs. 1.5 and 1.0 mL/g). Notably, the lobster mineral and its calcium were far more soluble than the CCS (98.4 vs. 18.6% for the products and 64.0 vs. 8.5% for their calcium) while the in vitro bioavailability of lobster calcium was 5.9-fold higher compared to that of the commercial product (11.95 vs. 1.99%). Furthermore, supplementing lobster minerals in media at ratios of 15%, 25%, and 35% (v/v) when growing cells did not induce any detectable changes in cell morphology and apoptosis. However, it had significant effects on cell growth and proliferation. The responses of cells after three days of culture supplemented with the lobster minerals, compared to the CCS supplementation, were significantly better with the bone cells (MG-63) and competitively quick with the skin cells (HaCaT). The cell growth reached 49.9-61.6% for the MG-63 and 42.9-53.4% for the HaCaT. Furthermore, the MG-63 and HaCaT cells proliferated considerably after seven days of incubation, reaching 100.3% for MG-63 and 115.9% for HaCaT with a lobster mineral supplementation of 15%. Macrophages (THP-1 cells) treated for 24 h with lobster minerals at concentrations of 1.24-2.89 mg/mL had no detectable changes in cell morphology while their viability was over 82.2%, far above the cytotoxicity threshold (<70%). All these results indicate that lobster minerals could be used as a source of functional or nutraceutical calcium for commercial products.

Identification of Antioxidative Peptides Derived from Arthrospira maxima in the Biorefinery Process after Extraction of C-Phycocyanin and Lipids.

Arthrospira maxima has been identified as a sustainable source of rich proteins with diverse functionalities and bioactivities. After extracting C-phycocyanin (C-PC) and lipids in a biorefinery process, the spent biomass still contains a large proportion of proteins with potential for biopeptide production. In this study, the residue was digested using Papain, Alcalase, Trypsin, Protamex 1.6, and Alcalase 2.4 L at different time intervals. The resulting hydrolyzed product with the highest antioxidative activity, evaluated through their scavenging capability of hydroxyl radicals, superoxide anion, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), was selected for further fractionation and purification to isolate and identify biopeptides. Alcalase 2.4 L was found to produce the highest antioxidative hydrolysate product after four-hour hydrolysis. Fractionating this bioactive product using ultrafiltration obtained two fractions with different molecular weights (MW) and antioxidative activity. The low-molecular-weight fraction (LMWF) with MW <3 kDa had higher DPPH scavenging activity with the IC50 value of 2.97 ± 0.33 compared to 3.76 ± 0.15 mg/mL of the high-molecular-weight fraction (HMWF) with MW >3 kDa. Two stronger antioxidative fractions (F-A and F-B) with the respective significant lower IC50 values of 0.83 ± 0.22 and 1.52 ± 0.29 mg/mL were isolated from the LMWF using gel filtration with a Sephadex G-25 column. Based on LC-MS/MS analysis of the F-A, 230 peptides derived from 108 A. maxima proteins were determined. Notably, different antioxidative peptides possessing various bioactivities, including antioxidation, were detected with high predicted scores together with in silico analyses on their stability and toxicity. This study established knowledge and technology to further value-add to the spent A. maxima biomass by optimizing hydrolysis and fraction processes to produce antioxidative peptides with Alcalase 2.4 L after two products already produced in a biorefinery. These bioactive peptides have potential applications in food and nutraceutical products.

Fear of COVID-19, healthy eating behaviors, and health-related behavior changes as associated with anxiety and depression among medical students: An online survey.

Background: Medical students' health and wellbeing are highly concerned during the COVID-19 pandemic. This study examined the impacts of fear of COVID-19 (FCoV-19S), healthy eating behavior, and health-related behavior changes on anxiety and depression. Methods: We conducted an online survey at 8 medical universities in Vietnam from 7th April to 31st May 2020. Data of 5,765 medical students were collected regarding demographic characteristics, FCoV-19S, health-related behaviors, healthy eating score (HES), anxiety, and depression. Logistic regression analyses were used to explore associations. Results: A lower likelihood of anxiety and depression were found in students with a higher HES score (OR = 0.98; 95%CI = 0.96, 0.99; p = 0.042; OR = 0.98; 95%CI = 0.96, 0.99; p = 0.021), and in those unchanged or more physical activities during the pandemic (OR = 0.54; 95%CI = 0.44, 0.66; p < 0.001; OR = 0.44; 95%CI = 0.37, 0.52; p < 0.001) as compared to those with none/less physical activity, respectively. A higher likelihood of anxiety and depression were reported in students with a higher FCoV-19S score (OR = 1.09; 95%CI = 1.07, 1.12; p < 0.001; OR = 1.06; 95%CI = 1.04, 1.08; p < 0.001), and those smoked unchanged/more during the pandemic (OR = 6.67; 95%CI = 4.71, 9.43; p < 0.001; OR = 6.77; 95%CI = 4.89, 9.38; p < 0.001) as compared to those stopped/less smoke, respectively. In addition, male students had a lower likelihood of anxiety (OR = 0.79; 95%CI = 0.65, 0.98; p = 0.029) compared to female ones. Conclusions: During the pandemic, FCoV-19S and cigarette smoking had adverse impacts on medical students' psychological health. Conversely, staying physically active and having healthy eating behaviors could potentially prevent medical students from anxiety and depressive symptoms.

Proteomics Identification of Targets for Intervention in Pressure Ulcers.

Pressure ulcers (PUs) are chronic wounds that lead to amputations and death. Little is known about why PUs are recalcitrant to healing. Wound healing is mediated by matrix metalloproteinases (MMPs). The 24 MMPs in humans each exist in three forms, of which only one is catalytically competent. We analyzed human PU samples using an affinity resin that exclusively binds to the catalytically competent MMPs. We identified by mass spectrometry the active forms of MMP-1, MMP-8, MMP-9, and MMP-14. Concentrations of MMP-8, MMP-9, and MMP-14 were higher in human PUs compared to the healthy tissue, whereas those for MMP-1 did not change. Decreasing levels of active MMP-9 as the PU improved argued for a detrimental role for this enzyme. In a mouse model of PUs, a highly selective inhibitor for MMP-9 and MMP-14, (R)-ND-336, accelerated wound closure in parallel with significant amelioration of ulcer stage. (R)-ND-336 holds promise as a first-in-class treatment for PUs.

Metabolism of the Selective Matrix Metalloproteinase-9 Inhibitor (R)-ND-336.

(R)-ND-336-designated as compound (R)-5-is a highly selective inhibitor of matrix metalloproteinase (MMP)-9 with efficacy in accelerating diabetic wound healing in murine models. (R)-ND-336 belongs to the class of thiirane inhibitors of MMPs and it is currently undergoing Investigation New Drug (IND)-enabling studies. We investigated the in vitro metabolism of (R)-ND-336 using S9 fractions obtained from mice, rats, dogs, minipigs, monkeys, and humans in order to select the rodent and nonrodent species for toxicology studies. Three metabolites were observed. One metabolite, M3, was observed across all species. Metabolite M2 was found in rats, monkeys, and humans. Metabolite M1 was observed only in rats. The identities of the metabolites were suggested by liquid chromatography/tandem mass spectroscopy (LC/MS-MS) analyses, which were authenticated by comparison to synthetic samples. Metabolites M2 and M3 arise from oxidative deamination of (R)-ND-336 by monoamine oxidase to give the arylaldehyde as a transient (and unobserved) intermediate. Reductive metabolism of this aldehyde gives the alcohol metabolite M2, while further oxidative metabolism of the aldehyde produces the carboxylate metabolite M3. A minor route of metabolism, seen only in rats, is N-acetylation of (R)-ND-336 to give the acetamide M1. The metabolism of (R)-ND-336 is distinctly different from that of the prototype member of this thiirane class ((±)-1, lacking the 4-aminomethyl aryl substituent) which is metabolized primarily by oxidation α to the sulfone to lead to a benzenesulfinate metabolite. All three metabolites are poorer MMP-9 inhibitors, compared to (R)-ND-336 (MMP-9, K i = 19 nM): M3, MMP-9 IC50 > 100 µM; M2, K i = 390 nM; and M1, IC50 > 100 µM). The rat and the minipig were selected as the rodent and nonrodent species, respectively, for toxicology studies.

Strategy for Treatment of Infected Diabetic Foot Ulcers.

Diabetic foot ulcers (DFUs) are chronic wounds that develop in 30% of diabetic patients. In DFUs, the normal wound healing process consisting of inflammation, angiogenesis, and extracellular matrix (ECM) remodeling is dysregulated and stalled. Upon injury, neutrophils and monocytes arrive at the wound and secrete matrix metalloproteinase (MMP)-8 and reactive oxygen species (ROS). ROS activates nuclear factor kappa beta (NF-κB), which upregulates MMP-9. Monocytes become macrophages, secreting tumor growth factor (TGF)-ß1 and vascular endothelial growth factor (VEGF) for angiogenesis, resulting in remodeling of the ECM. MMP-9 cleaves laminin for keratinocyte migration. MMP-8 is beneficial for remodeling the ECM and healing the wound. In DFUs, the excess unregulated MMP-9 is detrimental, destroying the ECM and preventing the wound from healing. DFUs are typically infected, many with biofilm-producing bacteria that are resistant to antibiotics. Infection increases the time for wound healing and the likelihood for a lower-limb amputation. Despite the use of antibiotics, amputations occur in 24.5% of patients with DFUs. Clearly, new strategies for treatment of DFUs are needed. With the use of an affinity resin that binds exclusively to the active forms of MMPs and proteomics, we identified two proteinases, MMP-8 and MMP-9, in wounds of diabetic mice and diabetic humans. With the use of selective inhibitors, gene ablation of MMP-9, and exogenous application of MMP-8, we demonstrated that MMP-8 is beneficial to wound repair and that MMP-9 prevents the diabetic wound from healing. Our research has shown that infection increases active MMP-9, increasing inflammation and decreasing angiogenesis. As a result, infected diabetic wounds take a longer time to heal than uninfected ones. We found that active MMP-9 and NF-κB increased in human DFUs with wound severity and infection. The best strategy for treatment of DFUs is to selectively inhibit the detrimental proteinase MMP-9 without affecting the beneficial MMP-8 so that the body can repair the wound. Lead optimization of the thiirane class of inhibitors led to the discovery of (R)-ND-336, a potent (19 nM) and selective (450-fold) MMP-9 inhibitor. (R)-ND-336 accelerated wound healing in diabetic mice by decreasing ROS and NF-κB, lowering inflammation, and increasing angiogenesis. (R)-ND-336 in combination with the antibiotic linezolid improved wound healing in infected diabetic mice by inhibiting MMP-9, which mitigated macrophage infiltration and increased angiogenesis, thereby restoring the normal wound healing process.

Selective MMP-9 Inhibitor (R)-ND-336 Alone or in Combination with Linezolid Accelerates Wound Healing in Infected Diabetic Mice.

Diabetic foot ulcers (DFUs) are a common complication of diabetes that are recalcitrant to healing due to persistent inflammation. The majority of DFUs have bacterial biofilms, with Staphylococcus epidermidis as a predominant bacterium, requiring infection control with antibiotics before treatment of the wound. Matrix metalloproteinases (MMPs) play roles in the pathology and repair of DFUs. However, defining the roles of the 24 human MMPs has been challenging due to the presence of three forms for each MMP, of which only one is catalytically competent, and the lack of convenient methods to distinguish among the three forms of MMPs. Using an affinity resin that binds only to the active forms of MMPs, with identification and quantification by mass spectrometry, we found that infected wounds in mice had increased levels of active MMP-9 compared to uninfected ones, paralleling infected human DFUs. MMP-9 activity prevents diabetic wounds from healing. We evaluated the efficacy of the selective small-molecule MMP-9 inhibitor, (R)-ND-336, in the infected diabetic mouse model of wound healing and showed that (R)-ND-336 alone or in combination with the antibiotic linezolid improves wound healing by inhibiting the detrimental MMP-9, mitigating macrophage infiltration to diminish inflammation, and increasing angiogenesis to restore the normal wound healing process. An advantage of this strategy is the ability to administer (R)-ND-336 concurrently with an antibiotic.

Digital Healthy Diet Literacy and Self-Perceived Eating Behavior Change during COVID-19 Pandemic among Undergraduate Nursing and Medical Students: A Rapid Online Survey.

Assessing healthy diet literacy and eating behaviors is critical for identifying appropriate public health responses to the COVID-19 pandemic. We examined the psychometric properties of digital healthy diet literacy (DDL) and its association with eating behavior changes during the COVID-19 pandemic among nursing and medical students. We conducted a cross-sectional study from 7 April to 31 May 2020 at 10 public universities in Vietnam, in which 7616 undergraduate students aged 19-27 completed an online survey to assess socio-demographics, clinical parameters, health literacy (HL), DDL, and health-related behaviors. Four items of the DDL scale loaded on one component explained 71.32%, 67.12%, and 72.47% of the scale variances for the overall sample, nursing, and medical students, respectively. The DDL scale was found to have satisfactory item-scale convergent validity and criterion validity, high internal consistency reliability, and no floor or ceiling effect. Of all, 42.8% of students reported healthier eating behavior during the pandemic. A 10-index score increment of DDL was associated with 18%, 23%, and 17% increased likelihood of healthier eating behavior during the pandemic for the overall sample (OR, 1.18; 95%CI, 1.13, 1.24; p < 0.001), nursing students (OR, 1.23; 95%CI, 1.10, 1.35; p < 0.001), and medical students (OR, 1.17; 95%CI, 1.11, 1.24; p < 0.001), respectively. The DDL scale is a valid and reliable tool for the quick assessment of digital healthy diet literacy. Students with higher DDL scores had a higher likelihood of healthier eating behavior during the pandemic.

Protein Recovery from Underutilised Marine Bioresources for Product Development with Nutraceutical and Pharmaceutical Bioactivities.

The global demand for dietary proteins and protein-derived products are projected to dramatically increase which cannot be met using traditional protein sources. Seafood processing by-products (SPBs) and microalgae are promising resources that can fill the demand gap for proteins and protein derivatives. Globally, 32 million tonnes of SPBs are estimated to be produced annually which represents an inexpensive resource for protein recovery while technical advantages in microalgal biomass production would yield secure protein supplies with minimal competition for arable land and freshwater resources. Moreover, these biomaterials are a rich source of proteins with high nutritional quality while protein hydrolysates and biopeptides derived from these marine proteins possess several useful bioactivities for commercial applications in multiple industries. Efficient utilisation of these marine biomaterials for protein recovery would not only supplement global demand and save natural bioresources but would also successfully address the financial and environmental burdens of biowaste, paving the way for greener production and a circular economy. This comprehensive review analyses the potential of using SPBs and microalgae for protein recovery and production critically assessing the feasibility of current and emerging technologies used for the process development. Nutritional quality, functionalities, and bioactivities of the extracted proteins and derived products together with their potential applications for commercial product development are also systematically summarised and discussed.

Awareness, Practices, and Demands of Traditional Medicine Providers for Continuous Medical Education in District Hospitals of Vietnam.

Expanding traditional medicine (TM) coverage in health care is a priority in Vietnam. Continuous medical education (CME) plays an important role in ensuring the quality of TM. However, evidence about TM CME in TM practitioners in Vietnam is insufficient. This paper aimed to evaluate the awareness, practice, and demands on TM CME among TM providers in district hospitals of Vietnam. This cross-sectional descriptive study was performed at the district level at TM hospitals and TM departments of general hospitals in Thanh Hoa Province. Demographic characteristics, awareness, practice, and demand for TM CME were collected via face-to-face interviews. Descriptive statistics and multivariable logistic regression models were applied to examine the factors associated with awareness, practice, and demand for TM CME. The majority of the respondents had ever heard of TM CME (87.5%). Only 60% received TM training in the last five years. Most respondents had a demand for CME (86.8%). The non-Kinh ethnic group (OR = 0.2, 95% CI: 0.1-0.8) and people who had a temporary contract (OR = 0.2, 95% CI: 0.1-0.7) were less likely to be ever heard about TM CME. Higher levels of education (college, OR = 14.1, 95% CI = 1.0-195.9; undergraduate, OR = 9.1, 95% CI = 1.9-44.6) are more likely to be ever heard of TM CME than the vocational training group. Those who regularly update their knowledge are more likely to have heard about TM CME (OR = 7.7, 95% CI = 2.8-21.7) and are more likely to have demands on TM CME (OR = 3.7, 95% CI = 1.2-11.5). Those who had heard about TM CME were more likely to take these courses in the last five years (OR = 6.9, 95% CI = 2.5-18.8). However, this result was the opposite for people with more years of experience (OR = 0.9, 95% CI: 0.8-0.9). There were limited awareness and participation in TM CME but was a high need for CME among TM providers at district hospitals in Vietnam. Promoting lifelong learning and providing promptly supports would be potential to increase the TM CME demands and participation among TM providers.

Fear of COVID-19 Scale-Associations of Its Scores with Health Literacy and Health-Related Behaviors among Medical Students.

The coronavirus disease 2019 (COVID-19) pandemic causes fear, as its immediate consequences for the public have produced unprecedented challenges for the education and healthcare systems. We aimed to validate the fear of COVID-19 scale (FCoV-19S) and examine the association of its scores with health literacy and health-related behaviors among medical students. A cross-sectional study was conducted from 7 to 29 April 2020 on 5423 students at eight universities across Vietnam, including five universities in the North, one university in the Center, two universities in the South. An online survey questionnaire was used to collect data on participants' characteristics, health literacy, fear of COVID-19 using the FCoV-19S, and health-related behaviors. The results showed that seven items of the FCoV-19S strongly loaded on one component, explained 62.15% of the variance, with good item-scale convergent validity and high internal consistency (Cronbach's alpha = 0.90). Higher health literacy was associated with lower FCoV-19S scores (coefficient, B, -0.06; 95% confidence interval, 95%CI, -0.08, -0.04; p < 0.001). Older age or last academic years, being men, and being able to pay for medication were associated with lower FCoV-19S scores. Students with higher FCoV-19S scores more likely kept smoking (odds ratio, OR, 1.11; 95% CI, 1.08, 1.14; p < 0.001) or drinking alcohol (OR, 1.04; 95% CI, 1.02, 1.06; p < 0.001) at an unchanged or higher level during the pandemic, as compared to students with lower FCoV-19S scores. In conclusion, the FCoV-19S is valid and reliable in screening for fear of COVID-19. Health literacy was found to protect medical students from fear. Smoking and drinking appeared to have a negative impact on fear of COVID-19. Strategic public health approaches are required to reduce fear and promote healthy lifestyles during the pandemic.

Limitations of Knockout Mice and Other Tools in Assessment of the Involvement of Matrix Metalloproteinases in Wound Healing and the Means to Overcome Them.

Matrix metalloproteinases (MMPs) play important roles in wound healing, but attribution of their functions in repair of wounds has been challenging. Commonly used tools such as MMP-knockout mice and zymography often confound analysis, which is complicated further as these enzymes exist in three distinct forms with only one being catalytically competent. With the use of topical exogenously administered recombinant MMP-8 and MMP-13 to diabetic and nondiabetic mouse wounds, we show that these proteinases facilitate wound repair by upregulating IL-6 and increasing neutrophil trafficking with an early onset of inflammation. Furthermore, by spatiotemporal control in the use of a selective MMP-2 inhibitor, along with immunoprecipitation and Western blotting, we provide definitive demonstration that MMP-2 does not affect wound healing, contrary to reports. MMP-2 is found in wounds complexed with TIMPs, which is catalytically incompetent.

Physicochemical properties of Arenga pinnata Merr. endosperm and its antidiabetic activity for nutraceutical application.

This study aims to provide information on physicochemical properties of Arenga pinnata endosperm (APE) and its antidiabetic activity for utilization in the food and pharmaceutical industries. The antidiabetic effect of APE was studied through an observational experiment on the blood glucose level of rats. The physicochemical properties of APE were determined using a texturometer, X-ray powder diffraction, Brookfield viscometer, scanning electron microscopy, Fourier-transform infrared spectroscopy, and light microscope. The APE was categorized based on its texture into three groups. The crystal structure of APE is microspore and amorf while the hydrogel has a non-Newtonian property and is stable at 50°C. The viscosity index was increased in the increasing temperature with the order of high viscosity of APE being 1, 2, and 3. The hydrogel shape of APE 1 and 3 was lameral in the concentration of 1.25%. For antidiabetic study, the findings demonstrated that the APE could reduce the blood glucose level. The APE powders 1 and 2 with the respective weight of 50 and 200 mg have significant effects on reducing rat blood glucose level compared to the diabetic rats. Based on these properties, APE could potentially be used as a natural antidiabetic food without having any side effect and in the pharmaceutical industry for some purposes.

Hyperbaric oxygen therapy accelerates wound healing in diabetic mice by decreasing active matrix metalloproteinase-9.

Diabetic foot ulcers are characterized by hypoxia. For many patients, hyperbaric oxygen (HBO) therapy is the last recourse for saving the limb from amputation, for which the molecular basis is not understood. We previously identified the active form of matrix metalloproteinase-9 (MMP-9) as responsible for diabetic foot ulcer's recalcitrance to healing. Transcription of mmp-9 to the inactive zymogen is upregulated during hypoxia. Activation of the zymogen is promoted by proteases and reactive oxygen species (ROS). We hypothesized that the dynamics of these two events might lead to a lowering of active MMP-9 levels in the wounded tissue. We employed the full-thickness excisional db/db mouse model to study wound healing, and treated the mice to 3.0 atm of molecular oxygen for 90 minutes, 5 days per week for 10 days in an HBO research chamber. Treatment with HBO accelerated diabetic wound healing compared to untreated mice, with more completed and extended reepithelialization. We imaged the wounds for ROS in vivo with a luminol-based probe and found that HBO treatment actually decreases ROS levels. The levels of superoxide dismutase, catalase, and glutathione peroxidase-enzymes that turn over ROS-increased after HBO treatment, hence the observation of decreased ROS. Since ROS levels are lowered, we explored the effect that this would have on activation of MMP-9. Quantitative analysis with an affinity resin that binds and pulls down the active MMPs exclusively, coupled with proteomics, revealed that HBO treatment indeed reduces the active MMP-9 levels. This work for the first time demonstrates that diminution of active MMP-9 is a contributing factor and a mechanism for enhancement of diabetic wound healing by HBO therapy.

Targeting MMP-9 in Diabetic Foot Ulcers.

Diabetic foot ulcers (DFUs) are significant complications of diabetes and an unmet medical need. Matrix metalloproteinases (MMPs) play important roles in the pathology of wounds and in the wound healing process. However, because of the challenge in distinguishing active MMPs from the two catalytically inactive forms of MMPs and the clinical failure of broad-spectrum MMP inhibitors in cancer, MMPs have not been a target for treatment of DFUs until recently. This review covers the discovery of active MMP-9 as the biochemical culprit in the recalcitrance of diabetic wounds to healing and targeting this proteinase as a novel approach for the treatment of DFUs. Active MMP-8 and MMP-9 were observed in mouse and human diabetic wounds using a batimastat affinity resin and proteomics. MMP-9 was shown to play a detrimental role in diabetic wound healing, whereas MMP-8 was beneficial. A new class of selective MMP-9 inhibitors shows clinical promise for the treatment of DFUs.

Identifying miRNA-mRNA regulatory relationships in breast cancer with invariant causal prediction.

BACKGROUND: microRNAs (miRNAs) regulate gene expression at the post-transcriptional level and they play an important role in various biological processes in the human body. Therefore, identifying their regulation mechanisms is essential for the diagnostics and therapeutics for a wide range of diseases. There have been a large number of researches which use gene expression profiles to resolve this problem. However, the current methods have their own limitations. Some of them only identify the correlation of miRNA and mRNA expression levels instead of the causal or regulatory relationships while others infer the causality but with a high computational complexity. To overcome these issues, in this study, we propose a method to identify miRNA-mRNA regulatory relationships in breast cancer using the invariant causal prediction. The key idea of invariant causal prediction is that the cause miRNAs of their target mRNAs are the ones which have persistent causal relationships with the target mRNAs across different environments. RESULTS: In this research, we aim to find miRNA targets which are consistent across different breast cancer subtypes. Thus, first of all, we apply the Pam50 method to categorize BRCA samples into different "environment" groups based on different cancer subtypes. Then we use the invariant causal prediction method to find miRNA-mRNA regulatory relationships across subtypes. We validate the results with the miRNA-transfected experimental data and the results show that our method outperforms the state-of-the-art methods. In addition, we also integrate this new method with the Pearson correlation analysis method and Lasso in an ensemble method to take the advantages of these methods. We then validate the results of the ensemble method with the experimentally confirmed data and the ensemble method shows the best performance, even comparing to the proposed causal method. CONCLUSIONS: This research found miRNA targets which are consistent across different breast cancer subtypes. Further functional enrichment analysis shows that miRNAs involved in the regulatory relationships predicated by the proposed methods tend to synergistically regulate target genes, indicating the usefulness of these methods, and the identified miRNA targets could be used in the design of wet-lab experiments to discover the causes of breast cancer.

Direct biodiesel production from wet spent coffee grounds.

Utilization of waste spent coffee grounds (SCG) remains limited and requires pre-treatment before being discarded to avoid pollution to the environment. Lipids contained in SCG could be converted to biodiesel through an in situ transesterification method. Current in situ transesterification of wet SCG biomass, conducted at high reaction temperature to reduce the water effect and reduce reaction time, is energy intensive. A new approach, which combines simultaneous extraction-transesterification in a single step using soxhlet apparatus, was developed to produce biodiesel directly from wet SCG biomass. A homogeneous base catalyst at a concentration of 0.75 M showed better catalytic activity than acid, with hexane as a co-solvent on fatty acid (FA) extraction efficiency and FA to fatty acid methyl ester (FAME) conversion efficiency. Studying the factorial effect of ratio of methanol to hexane and reaction time led to the highest FA to FAME conversion efficiency of 97% at a ratio of 1 : 2 and 30 min reaction time. In addition, the catalyst could be used five times without losing its activity. In term of energy consumption, the reactive extraction soxhlet (RES) method could save 38-99% of energy compared to existing methods.

Validation of Matrix Metalloproteinase-9 (MMP-9) as a Novel Target for Treatment of Diabetic Foot Ulcers in Humans and Discovery of a Potent and Selective Small-Molecule MMP-9 Inhibitor That Accelerates Healing.

Diabetic foot ulcers (DFUs) are a significant health problem. A single existing FDA-approved drug for this ailment, becaplermin, is not standard-of-care. We previously demonstrated that upregulation of active matrix metalloproteinase (MMP)-9 is the reason that the diabetic wound in mice is recalcitrant to healing and that MMP-8 participates in wound repair. In the present study, we validate the target MMP-9 by identifying and quantifying active MMP-8 and MMP-9 in human diabetic wounds using an affinity resin that binds exclusively to the active forms of MMPs coupled with proteomics. Furthermore, we synthesize and evaluate enantiomerically pure ( R)- and ( S)-ND-336, as inhibitors of the detrimental MMP-9, and show that the ( R)-enantiomer has superior efficacy in wound healing over becaplermin. Our results reveal that the mechanisms of pathology and repair are similar in diabetic mice and diabetic humans and that ( R)-ND-336 holds promise for the treatment of DFUs as a first-in-class therapeutic.

Expression of active matrix metalloproteinase-9 as a likely contributor to the clinical failure of aclerastide in treatment of diabetic foot ulcers.

Chronic wounds are a complication of diabetes. Treatment for diabetic foot ulcers is complex with little clinical recourse, resulting in 108,000 lower-limb amputations annually in the United States alone. Matrix metalloproteinases (MMPs) play important roles in the pathology and in the repair of chronic wounds. We previously identified active MMP-8 and MMP-9 in wounds of diabetic mice and determined that MMP-8 accelerates wound repair, while MMP-9 is the culprit for the diabetic wound being refractory to healing. Aclerastide, a peptide analog of angiotensin II, recently failed in phase III clinical trials for treatment of diabetic foot ulcers. We demonstrate herein that treatment of wounds of diabetic mice with aclerastide results in elevated levels of reactive oxygen species and of active MMP-9, which is likely an important contributor to the failure of aclerastide in clinical trials.