BACKGROUND

Curcumin has been investigated as a potential natural solution to prevent or even treat skeletal muscle decline. There are a number of externally sourced finished products (ie, those imported from other countries) containing curcumin, but high cost limits their usage. The emerging research and development of locally sourced curcumin is an opportunity to produce high-quality oral supplements comparable to existing imported products.

The primary purpose of this study is to determine the effects of oral administration of a local curcumin formulation on skeletal muscle using an animal model that similarly demonstrated the course of human sarcopenia.

Purpose-bred 11- to 12-week-old female Sprague Dawley (SD) rats will be used in this study. SD rats are extensively used in animal models of human diseases and conditions such as diabetes, obesity and sarcopenia. Female rats have been selected because they do not demonstrate more temperature or activity variance and have more stable behavior compared to males. To simulate sarcopenia in this animal model, the tail suspension (TS) method was utilized. The TS method involves decreased hind limb function by suspending the animal’s tail for the duration of treatment. The laboratory animals will be randomized to receive any of the four treatments: (1) low-dose curcumin + vehicle; (2) high-dose curcumin + vehicle; (3) vehicle only; and (4) control (distilled water). The interventions will be subdivided into two: 2-week treatment and 4-week treatment. The gastrocnemius muscles on both sides will be excised and weighed, and the muscle tissues subjected to rapid freezing in acetone-dry ice and sliced into 10 μm-thick sections for staining. Examination of muscle architecture and computation of atrophy factors will be performed. The presence of connective tissue, fat tissue and number of atrophic muscle cells will be determined. Accurate quantitative detection of the rat total AMP (adenosine monophosphate)-Activated Protein Kinase will be performed in the gastrocnemius muscle tissue utilizing the enzyme-linked immunosorbent assay kit.

BACKGROUND

Rabies remains to be a neglected tropical disease in the Philippines, with the country reporting a higher number of cases compared to its counterparts in Asia.

To describe the demographics, animal bite characteristics, and post-exposure prophylaxis of animal bite patients coming in for care at the Research Institute for Tropical Medicine (RITM), a large government referral center for infectious diseases, and animal bites.

Electronic patient records from January 1, 2018 to December 31, 2019 were obtained from the National Rabies Information System (NaRIS) database of the Department of Health, and summarized using applicable descriptive statistics.

A total of 14,614 patients were included over the two-year study period, and more than third of the patients were children below 15 years old, while more than half were adult males. Lower extremities were the most frequently affected area, while with children, more than a third of exposures were in the head and neck areas. Intradermal route was mostly used for the post-exposure prophylaxis, while WHO prequalified vaccines were utilized in more than 90% of the patients. Only 55.7% of patients completed the prophylaxis regimen at RITM.

These findings reflect the significant exposure of children from animal bites, and the non-compliance of patients to the prescribed post-exposure prophylaxis.

Animals, Wild ; Borneo ; Malaysia ; Biosurveillance

INTRODUCTION

Effective mosquito control is pivotal in the epidemiology of vector-borne diseases, but no successful preventive measures have been recorded for dengue vector control. Hence, possible alternatives to chemical larvicides have been explored, including plant alcoholic extracts. This study determined the larvicidal efficacy of Annona squamosa ethanolic leaf extracts against third instar larvae of Aedes aegypti.

Three replicates of varying concentrations of Annona squamosa ethanolic extract (i.e., 10%, 40%, and 70%) versus positive (Novaluron) and negative controls (tap water) were used to determine larval mortality.

Greatest larval mortality was noted using the 70% concentration (i.e., 24% versus the observed values of 20% and 8%, respectively for the 40% and 10% ethanolic concentrations). Relative to the controls, the mean differences in the mortality rates of the Aedes aegypti larvae across the leaf ethanolic concentrations were statistically significant (i.e., p-value < 0.05). There was increasing trend in larval mortality over time, but 50% lethal dose was not achieved. In conclusion, the different Annona squamosa ethanolic leaf extracts could be used as alternative botanical larvicides against Aedes species.

OBJECTIVE

Given that rabies remains endemic in the Philippines despite government interventions and the pandemicrelated restrictions have hampered its surveillance, this study aimed to estimate the effect of human population, anti-rabies vaccination efforts, and COVID-19 situation on the spread of rabies cases in the districts of Davao City, Philippines.

A retrospective study of the canine records at Davao City Veterinarians’ Office was done from January 2018 to June 2021. Monthly rabies cases were ascertained, and the effect of the human population, COVID-19 season, and vaccination ratio on rabies cases was estimated using panel regression models adjusting for confounding factors.

The reporting of rabies cases was lower during COVID-19 than during the non-COVID-19 season, with an IRR of 0.52 [95% confidence interval (CI): 0.33–0.82]. Furthermore, rabies cases increased by 2.23% (95% CI: 0.60–3.89) per 1% increase in vaccination ratio. Additionally, high-population districts recorded more rabies cases than low-population districts.

Consistency in monitoring rabies cases during the pandemic is suggested as a roadmap for future program initiatives. Vaccination efforts should be reinforced to increase rabies awareness and ensure early response to emerging diseases. Moreover, highpopulated districts should be prioritized in implementing rabies control interventions to gain optimal development.

BACKGROUND AND OBJECTIVE

Rabies continues to be a challenge in Davao City despite the efforts of the city’s local government to vaccinate primarily the non-stray dog population. Meanwhile, studies have shown that time-dependent vaccination strategy is considered a prime factor for a cost-effective rabies control strategy. Hence, this study aims to provide information that will determine the optimal vaccination strategy targeted to the stray dog population that minimizes the rabies-infected dog population and vaccination costs using optimal control theory (OCT).

OCT is used to identify the optimal level of key rabies control, i.e., vaccination. Here, OCT was applied to a modified Susceptible-Exposed-Infectious-Vaccinated (SEIV) compartmental model. The study's key parameters were derived from published articles on rabies in Davao City and similar regions, along with the city's rabies reports.

The findings revealed that while rabies remains endemic in the city, it is possible to reduce the number of cases through consistent implementation of vaccination programs to the exposed and susceptible dog populations. Nevertheless, the feasibility of these findings relies to the effective targeting of vaccine coverage for the dog population. From the simulations performed, the exposed dog population (i.e., pre-rabid dogs) was able to reach zero observation when the transmission rate (?) is 0.001 for all values of anti-rabies vaccine coverages for exposed (?) and susceptible (b) dog populations and ? = 0.01 only when ? = 0.7 and b = 0.7, ? = 0.7 and b = 0.5, and ? = 0.5 and b = 0.7. Consequently, the number of infectious dogs will thereby decrease. Moreover, a nonlinear correspondence was also observed in all scenarios between the vaccination rate and the number of rabies-exposed dogs such that the reduction in the incidence of rabies cases becomes apparent only when the vaccination rate is at least 0.9995.

In high rabies transmissibility scenarios, a time-dependent vaccination strategy demonstrated a reduction in the number of rabies-infected dogs. However, this approach involves a trade-off, limiting the period during which monthly vaccinations can be relaxed. Consequently, a robust and timely vaccination program for dogs is crucial to manage high rabies transmission rates. Lastly, the model simulation underscores the importance of initiating monthly vaccinations.

OBJECTIVE: To investigate the effects and underlying mechanisms of VX765 on osteoarthritis (OA) and chondrocytes inflammation in rats. METHODS: Chondrocytes were isolated from the knee joints of 4-week-old Sprague Dawley (SD) rats. The third-generation cells were subjected to cell counting kit 8 (CCK-8) analysis to assess the impact of various concentrations (0, 1, 5, 10, 20, 50, 100 μmol/L) of VX765 on rat chondrocyte activity. An in vitro lipopolysaccharide (LPS) induced cell inflammation model was employed, dividing cells into control group, LPS group, VX765 concentration 1 group and VX765 concentration 2 group without obvious cytotoxicity. Western blot, real-time fluorescence quantitative PCR, and ELISA were conducted to measure the expression levels of inflammatory factors-transforming growth factor β ₁ (TGF-β ₁), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α). Additionally, Western blot and immunofluorescence staining were employed to assess the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1). Thirty-two SD rats were randomly assigned to sham surgery group (group A), OA group (group B), OA+VX765 (50 mg/kg) group (group C), and OA+VX765 (100 mg/kg) group (group D), with 8 rats in each group. Group A underwent a sham operation with a medial incision, while groups B to D underwent additional transverse incisions to the medial collateral ligament and anterior cruciate ligament, with removal of the medial meniscus. One week post-surgery, groups C and D were orally administered 50 mg/kg and 100 mg/kg VX765, respectively, while groups A and B received an equivalent volume of saline. Histopathological examination using HE and safranin-fast green staining was performed, and Mankin scoring was utilized for evaluation. Immunohistochemical staining technique was employed to analyze the expressions of matrix metalloproteinase 13 (MMP-13) and collagen type Ⅱ. RESULTS: The CCK-8 assay indicated a significant decrease in cell viability at VX765 concentrations exceeding 10 μmol/L ( P<0.05), so 4 μmol/L and 8 μmol/L VX765 without obvious cytotoxicity were selected for subsequent experiments. Following LPS induction, the expressions of TGF-β ₁, IL-6, and TNF-α in cells significantly increased when compared with the control group ( P<0.05). However, intervention with 4 μmol/L and 8 μmol/L VX765 led to a significant decrease in expression compared to the LPS group ( P<0.05). Western blot and immunofluorescence staining demonstrated a significant upregulation of Nrf2 pathway-related molecules Nrf2 and HO-1 protein expressions by VX765 ( P<0.05), indicating Nrf2 pathway activation. Histopathological examination of rat knee joint tissues and immunohistochemical staining revealed that, compared to group B, treatment with VX765 in groups C and D improved joint structural damage in rat OA, alleviated inflammatory reactions, downregulated MMP-13 expression, and increased collagen type Ⅱ expression. CONCLUSION VX765 can improve rat OA and reduce chondrocyte inflammation, possibly through the activation of the Nrf2 pathway.
Rats ; Animals ; Chondrocytes/metabolism* ; Matrix Metalloproteinase 13/metabolism* ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha/metabolism* ; Collagen Type II/metabolism* ; Interleukin-6 ; Lipopolysaccharides/pharmacology* ; NF-E2-Related Factor 2/pharmacology* ; Inflammation/drug therapy* ; Osteoarthritis/metabolism* ; Transforming Growth Factor beta1/metabolism* ; Dipeptides ; para-Aminobenzoates

OBJECTIVE: To Investigate the effects of lithocholic acid (LCA) on the balance between osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). METHODS: Twelve 10-week-old SPF C57BL/6J female mice were randomly divided into an experimental group (undergoing bilateral ovariectomy) and a control group (only removing the same volume of adipose tissue around the ovaries), with 6 mice in each group. The body mass was measured every week after operation. After 4 weeks post-surgery, the weight of mouse uterus was measured, femur specimens of the mice were taken for micro-CT scanning and three-dimensional reconstruction to analyze changes in bone mass. Tibia specimens were taken for HE staining to calculate the number and area of bone marrow adipocytes in the marrow cavity area. ELISA was used to detect the expression of bone turnover markers in the serum. Liver samples were subjected to real-time fluorescence quantitative PCR (RT-qPCR) to detect the expression of key genes related to bile acid metabolism, including cyp7a1, cyp7b1, cyp8b1, and cyp27a1. BMSCs were isolated by centrifugation from 2 C57BL/6J female mice (10-week-old). The third-generation cells were exposed to 0, 1, 10, and 100 μmol/L LCA, following which cell viability was evaluated using the cell counting kit 8 assay. Subsequently, alkaline phosphatase (ALP) staining and oil red O staining were conducted after 7 days of osteogenic and adipogenic induction. RT-qPCR was employed to analyze the expressions of osteogenic-related genes, namely ALP, Runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), as well as adipogenic-related genes including Adiponectin (Adipoq), fatty acid binding protein 4 (FABP4), and peroxisome proliferator-activated receptor γ (PPARγ). RESULTS: Compared with the control group, the body mass of the mice in the experimental group increased, the uterus atrophied, the bone mass decreased, the bone marrow fat expanded, and the bone metabolism showed a high bone turnover state. RT-qPCR showed that the expressions of cyp7a1, cyp8b1, and cyp27a1, which were related to the key enzymes of bile acid metabolism in the liver, decreased significantly ( P<0.05), while the expression of cyp7b1 had no significant difference ( P>0.05). Intervention with LCA at concentrations of 1, 10, and 100 μmol/L did not demonstrate any apparent toxic effects on BMSCs. Furthermore, LCA inhibited the expressions of osteogenic-related genes (ALP, Runx2, and OCN) in a dose-dependent manner, resulting in a reduction in ALP staining positive area. Concurrently, LCA promoted the expressions of adipogenic-related genes (Adipoq, FABP4, and PPARγ), and an increase in oil red O staining positive area. CONCLUSION After menopause, the metabolism of bile acids is altered, and secondary bile acid LCA interferes with the balance of osteogenic and adipogenic differentiation of BMSCs, thereby affecting bone remodelling.
Female ; Mice ; Animals ; Core Binding Factor Alpha 1 Subunit/pharmacology* ; PPAR gamma/metabolism* ; Steroid 12-alpha-Hydroxylase/metabolism* ; Mice, Inbred C57BL ; Cell Differentiation ; Osteogenesis ; Mesenchymal Stem Cells ; Bile Acids and Salts/pharmacology* ; Bone Marrow Cells ; Cells, Cultured ; Azo Compounds

OBJECTIVE: To explore the effect of chitosan (CS) hydrogel loaded with tendon-derived stem cells (TDSCs; hereinafter referred to as TDSCs/CS hydrogel) on tendon-to-bone healing after rotator cuff repair in rabbits. METHODS: TDSCs were isolated from the rotator cuff tissue of 3 adult New Zealand white rabbits by Henderson step-by-step enzymatic digestion method and identified by multidirectional differentiation and flow cytometry. The 3rd generation TDSCs were encapsulated in CS to construct TDSCs/CS hydrogel. The cell counting kit 8 (CCK-8) assay was used to detect the proliferation of TDSCs in the hydrogel after 1-5 days of culture in vitro, and cell compatibility of TDSCs/CS hydrogel was evaluated by using TDSCs alone as control. Another 36 adult New Zealand white rabbits were randomly divided into 3 groups ( n=12): rotator cuff repair group (control group), rotator cuff repair+CS hydrogel injection group (CS group), and rotator cuff repair+TDSCs/CS hydrogel injection group (TDSCs/CS group). After establishing the rotator cuff repair models, the corresponding hydrogel was injected into the tendon-to-bone interface in the CS group and TDSCs/CS group, and no other treatment was performed in the control group. The general condition of the animals was observed after operation. At 4 and 8 weeks, real-time quantitative PCR (qPCR) was used to detect the relative expressions of tendon forming related genes (tenomodulin, scleraxis), chondrogenesis related genes (aggrecan, sex determining region Y-related high mobility group-box gene 9), and osteogenesis related genes (alkaline phosphatase, Runt-related transcription factor 2) at the tendon-to-bone interface. At 8 weeks, HE and Masson staining were used to observe the histological changes, and the biomechanical test was used to evaluate the ultimate load and the failure site of the repaired rotator cuff to evaluate the tendon-to-bone healing and biomechanical properties. RESULTS: CCK-8 assay showed that the CS hydrogel could promote the proliferation of TDSCs ( P<0.05). qPCR results showed that the expressions of tendon-to-bone interface related genes were significantly higher in the TDSCs/CS group than in the CS group and control group at 4 and 8 weeks after operation ( P<0.05). Moreover, the expressions of tendon-to-bone interface related genes at 8 weeks after operation were significantly higher than those at 4 weeks after operation in the TDSCs/CS group ( P<0.05). Histological staining showed the clear cartilage tissue and dense and orderly collagen formation at the tendon-to-bone interface in the TDSCs/CS group. The results of semi-quantitative analysis showed that compared with the control group, the number of cells, the proportion of collagen fiber orientation, and the histological score in the TDSCs/CS group increased, the vascularity decreased, showing significant differences ( P<0.05); compared with the CS group, the proportion of collagen fiber orientation and the histological score in the TDSCs/CS group significantly increased ( P<0.05), while there was no significant difference in the number of cells and vascularity ( P>0.05). All samples in biomechanical testing failed at the repair site during the testing process. The ultimate load of the TDSCs/CS group was significantly higher than that of the control group ( P<0.05), but there was no significant difference compared to the CS group ( P>0.05). CONCLUSION TDSCs/CS hydrogel can induce cartilage regeneration to promote rotator cuff tendon-to-bone healing.
Rabbits ; Animals ; Rotator Cuff/surgery* ; Chitosan ; Hydrogels ; Rotator Cuff Injuries/surgery* ; Wound Healing ; Tendons/surgery* ; Collagen ; Stem Cells ; Biomechanical Phenomena

OBJECTIVE: To summarize the progress of the roles and mechanisms of various types of stem cell-based treatments and their combination therapies in both animal studies and clinical trials of lymphedema. METHODS: The literature on stem cell-based treatments for lymphedema in recent years at home and abroad was extensively reviewed, and the animal studies and clinical trials on different types of stem cells for lymphedema were summarized. RESULTS: Various types of stem cells have shown certain effects in animal studies and clinical trials on the treatment of lymphedema, mainly through local differentiation into lymphoid endothelial cells and paracrine cytokines with different functions. Current research focuses on two cell types, adipose derived stem cells and bone marrow mesenchymal stem cells, both of which have their own advantages and disadvantages, mainly reflected in the therapeutic effect of stem cells, the difficulty of obtaining stem cells and the content in vivo. In addition, stem cells can also play a synergistic role in combination with other treatments, such as conservative treatment, surgical intervention, cytokines, biological scaffolds, and so on. However, it is still limited to the basic research stage, and only a small number of studies have completed clinical trials. CONCLUSION Stem cells have great transformation potential in the treatment of lymphedema, but there is no unified standard in the selection of cell types, the amount of transplanted cells, and the timing of transplantation.
Animals ; Endothelial Cells ; Lymphedema/therapy* ; Stem Cell Transplantation ; Cytokines