OBJECTIVE: To examine the mechanism of action of tanshinone II A (Tan II A) in promoting chemosensitization of osteosarcoma cells to cisplatin (DDP). METHODS: The effects of different concentrations of Tan II A (0-80 µ mol/L) and DDP (0-2 µ mol/L) on the proliferation of osteosarcoma cell lines (U2R, U2OS, 143B, and HOS) at different times were examined using the cell counting kit-8 and colony formation assays. Migration and invasion of U2R and U2OS cells were detected after 24 h treatment with 30 µ mol/L Tan II A, 0.5 µ mol/L DDP alone, and a combination of 10 µ mol/L Tan II A and 0.25 µ mol/L DDP using the transwell assay. After 48 h of treatment of U2R and U2OS cells with predetermined concentrations of each group of drugs, the cell cycle was analyzed using a cell cycle detection kit and flow cytometry. After 48 h treatment, apoptosis of U2R and U2OS cells was detected using annexin V-FITC apoptosis detection kit and flow cytometry. U2R cells were inoculated into the unilateral axilla of nude mice and then the mice were randomly divided into 4 groups of 6 nude mice each. The 4 groups were treated with equal volume of Tan II A (15 mg/kg), DDP (3 mg/kg), Tan II A (7.5 mg/kg) + DDP (1.5 mg/kg), and normal saline, respectively. The body weight of the nude mice was weighed, and the tumor volume and weight were measured. Cell-related gene and signaling pathway expression were detected by RNA sequencing and Kyoto Encyclopedia of Genes and Genomes pathway analysis. p38 MAPK signaling pathway proteins and apoptotic protein expressions were detected by Western blot. RESULTS: In vitro studies have shown that Tan II A, DDP and the combination of Tan II A and DDP inhibit the proliferation, migration and invasion of osteosarcoma cells. The inhibitory effect was more pronounced in the Tan II A and DDP combined treatment group (P<0.05 or P<0.01). Osteosarcoma cells underwent significantly cell-cycle arrest and cell apoptosis by Tan II A-DDP combination treatment (P<0.05 or P<0.01). In vivo studies demonstrated that the Tan II A-DD combination treatment group significantly inhibited tumor growth compared to the Tan II A and DDP single drug group (P<0.01). Additionally, we found that the combination of Tan II A and DDP treatment enhanced the p38 MAPK signaling pathway. Western blot assays showed higher p-p38, cleaved caspase-3, and Bax and lower caspase-3, and Bcl-2 expressions with the combination of Tan II A and DDP treatment compared to the single drug treatment (P<0.01). CONCLUSION Tan II A synergizes with DDP by activating the p38/MAPK pathway to upregulate cleaved caspase-3 and Bax pro-apoptotic gene expressions, and downregulate caspase-3 and Bcl-2 inhibitory apoptotic gene expressions, thereby enhancing the chemosensitivity of osteosarcoma cells to DDP.
Abietanes/therapeutic use* ; Osteosarcoma/enzymology* ; Cisplatin/therapeutic use* ; Humans ; Cell Line, Tumor ; Animals ; Apoptosis/drug effects* ; Mice, Nude ; Cell Proliferation/drug effects* ; Cell Movement/drug effects* ; p38 Mitogen-Activated Protein Kinases/metabolism* ; MAP Kinase Signaling System/drug effects* ; Bone Neoplasms/enzymology* ; Cell Cycle/drug effects* ; Xenograft Model Antitumor Assays ; Mice ; Drug Resistance, Neoplasm/drug effects* ; Neoplasm Invasiveness ; Mice, Inbred BALB C

OBJECTIVE: To investigate the therapeutic potential of pseudolaric acid B (PAB) on non-alcoholic fatty liver disease (NAFLD) and its underlying molecular mechanism in vitro and in vivo. METHODS: Eight-week-old male C57BL/6J mice (n=32) were fed either a normal chow diet (NCD) or a high-fat diet (HFD) for 8 weeks. The HFD mice were divided into 3 groups according to a simple random method, including HFD, PAB low-dose [10 mg/(kg·d), PAB-L], and PAB high-dose [20 mg/(kg·d), PAB-H] groups. After 8 weeks of treatment, glucose metabolism and insulin resistance were assessed by oral glucose tolerance test (OGTT) and insulin tolerance test (ITT). Biochemical assays were used to measure the serum and cellular levels of total cholesterol (TC), triglycerides (TG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). White adipose tissue (WAT), brown adipose tissue (BAT) and liver tissue were subjected to hematoxylin and eosin (H&E) staining or Oil Red O staining to observe the alterations in adipose tissue and liver injury. PharmMapper and DisGeNet were used to predict the NAFLD-related PAB targets. Peroxisome proliferator-activated receptor alpha (PPARα) pathway involvement was suggested by Kyoto Encyclopedia of Genes and Genomes (KEGG) and search tool Retrieval of Interacting Genes (STRING) analyses. Luciferase reporter assay, cellular thermal shift assay (CETSA), and drug affinity responsive target stability assay (DARTS) were conducted to confirm direct binding of PAB with PPARα. Molecular dynamics simulations were applied to further validate target engagement. RT-qPCR and Western blot were performed to assess the downstream genes and proteins expression, and validated by PPARα inhibitor MK886. RESULTS: PAB significantly reduced serum TC, TG, LDL-C, AST, and ALT levels, and increased HDL-C level in HFD mice (P<0.01). Target prediction analysis indicated a significant correlation between PAB and PPARα pathway. PAB direct target binding with PPARα was confirmed through luciferase reporter assay, CETSA, and DARTS (P<0.05 or P<0.01). The target engagement between PAB and PPARα protein was further confirmed by molecular dynamics simulations and the top 3 amino acid residues, LEU321, MET355, and PHE273 showed the most significant changes in mutational energy. Subsequently, PAB upregulated the genes expressions involved in lipid metabolism and mitochondrial biogenesis downstream of PPARα (P<0.05 or P<0.01). Significantly, the PPARα inhibitor MK886 effectively reversed the lipid-lowering and PPARα activation properties of PAB (P<0.05 or P<0.01). CONCLUSION PAB mitigates lipid accumulation, ameliorates liver damage, and improves mitochondrial biogenesis by binding with PPARα, thus presenting a potential candidate for pharmaceutical development in the treatment of NAFLD.
Animals ; PPAR alpha/metabolism* ; Non-alcoholic Fatty Liver Disease/pathology* ; Male ; Mice, Inbred C57BL ; Lipid Metabolism/drug effects* ; Diterpenes/therapeutic use* ; Organelle Biogenesis ; Diet, High-Fat ; Humans ; Mice ; Liver/metabolism* ; Insulin Resistance ; Mitochondria/metabolism* ; Molecular Docking Simulation

OBJECTIVES: Oxaliplatin (OXA) and 5-fluorouracil (5-FU) are 2 commonly used chemotherapeutic agents for colorectal cancer (CRC). MicroRNAs (miRNAs, miRs) play crucial roles in the development of chemoresistance in various cancers. However, the role and mechanism of miR-224-5p in regulating CRC chemoresistance remain unclear. This study aims to investigate the function of miR-224-5p in chemoresistant CRC cells and the underlying mechanisms. METHODS: CRC datasets GSE28702 and GSE69657 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed miRNAs between drug-sensitive and resistant groups (OXA or 5-FU) were analyzed, and miR-224-5p was identified as the target miRNA. Chemoresistant cell lines HCT15-OXR, HCT15-5-FU, SW480-OXR, and SW480-5-FU were established. Transient transfections were performed using miR-224-5p mimics, inhibitors, and their respective negative controls (control mimic, control inhibitor) in these cell lines. Cells were treated with different concentrations of OXA or 5-FU post-transfection, and the half-maximal inhibitory concentration (IC₅₀) was determined using the cell counting kit-8 (CCK-8) assay. Cell proliferation was assessed by CCK-8 and colony formation assays. The expression levels of miR-224-5p, LC3, and P62 were measured by real-time polymerase chain reaction (real-time PCR) and/or Western blotting. Autophagic flux was assessed using a tandem fluorescent-tagged LC3 reporter assay. TargetScan 8.0, miRTarBase, miRPathDB, and HADb were used to predict B-cell lymphoma-2 (Bcl-2) as a potential miR-244-5p target, which was further validated by dual-luciferase reporter assays. RESULTS: Chemoresistant CRC cells exhibited down-regulated miR-224-5p expression, whereas up-regulation of miR-224-5p enhanced chemotherapy sensitivity. Exposure to OXA or 5-FU significantly increased autophagic activity in chemoresistant CRC cells, which was reversed by miR-224-5p overexpression. Dual-luciferase assays verified Bcl-2 as a direct target of miR-224-5p. CONCLUSIONS MiR-224-5p regulates chemoresistance in CRC by modulating autophagy through direct targeting of Bcl-2.
Humans ; MicroRNAs/physiology* ; Colorectal Neoplasms/drug therapy* ; Drug Resistance, Neoplasm/genetics* ; Autophagy/drug effects* ; Fluorouracil/pharmacology* ; Oxaliplatin ; Cell Line, Tumor ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Gene Expression Regulation, Neoplastic

Stathmin 1 (STMN1) is a microtubule-binding cytoplasmic phosphoprotein that promotes microtubule depolymerization or inhibits microtubule assembly, thereby regulating cytoskeletal organization and cell cycle progression. STMN1 is upregulated in a variety of malignant tumors, where it drives proliferation, invasion, metastasis, and angiogenesis through classic pathways such as nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and ferroptosis. STMN1 can also modulate the function of immune cells, thereby influencing antitumor immunity. Clinical data show that its high expression correlates positively with tumor drug resistance and poor prognosis, suggesting that STMN1 has potential as a tumor biomarker and therapeutic molecular target with important clinical significance.
Humans ; Stathmin/metabolism* ; Neoplasms/genetics* ; Biomarkers, Tumor/metabolism* ; NF-kappa B/metabolism* ; Cell Proliferation ; Drug Resistance, Neoplasm

Objective:Multi-drug resistant bacterial infection（MRSA） complications occurring in cochlear implant recipients is rare and of serious consequence. This paper aimed to summarize the treatment experience of a patient with MRSA infection after cochlear implantation. A patient with nasopharyngeal malignant tumor after radiotherapy developed to severe sensorineural deafness. She suffered MRSA infection nine days after cochlear implantation. Since the wound failed to heal after weeks of topical and systemic sensitive antibiotic therapy, the patient underwent surgery for wound debridement. The stimulator-receiver and the electrode of the implant was removed, negative pressure wound therapy was applied, and systemic anti-infection treatment with sensitive antibiotics for weeks, the patients recovered and was discharged from hospital 69 days after infection.
Humans ; Cochlear Implantation/adverse effects* ; Female ; Drug Resistance, Multiple, Bacterial ; Staphylococcal Infections/therapy* ; Methicillin-Resistant Staphylococcus aureus ; Cochlear Implants ; Anti-Bacterial Agents/therapeutic use* ; Postoperative Complications ; Middle Aged

Head and neck squamous cell carcinoma （HNSCC） is one of the ten most common cancers worldwide and is one of the refractory cancers with a poor prognosis in otorhinolaryngology-head and neck surgery. Cetuximab is widely used in the clinical treatment of HNSCC and has been approved by the FDA as a first-line chemotherapeutic agent. However, its efficacy varies significantly among different individuals. Therefore, exploring the resistance mechanisms of cetuximab in the treatment of HNSCC and screening for sensitive populations are essential for the precision treatment of head and neck cancer. This article summarizes the research progress on cetuximab resistance mechanisms in HNSCC, and the main aspects include: alterations in epidermal growth factor receptor （EGFR） and its ligands, changes in downstream effectors of EGFR, bypass activation and crosstalk, epithelial-mesenchymal transition, epigenetic modifications, and immunosuppression in the tumor microenvironment.
Humans ; Cetuximab/therapeutic use* ; Drug Resistance, Neoplasm ; Squamous Cell Carcinoma of Head and Neck/drug therapy* ; Head and Neck Neoplasms/drug therapy* ; ErbB Receptors/metabolism* ; Tumor Microenvironment ; Epithelial-Mesenchymal Transition ; Molecular Targeted Therapy ; Antineoplastic Agents, Immunological/therapeutic use*

BACKGROUND

Invasive candidiasis is defined by the growth of Candida species in the bloodstream or other internal organs. It is a global concern due to increasing multidrug resistance and high mortality rates. This study aimed to update prevalence data on Candida infections in the Philippines, analyzing demographic factors (age, sex), specimen sources, and associated risk factors. We compared antifungal resistance patterns against CLSI epidemiological cutoff values (ECVs) and clinical breakpoints and examined MIC variations by underlying disease to inform potential standardized empiric therapies.

We conducted a retrospective analytical cross-sectional study (SLMC-IERC approval, minimal risk) reviewing one year of Candida speciation and susceptibility results from January 2024 to December 2024 at a private tertiary hospital. All aseptically collected samples that tested positive for Candida species were included. Respiratory and wound specimens required a Gram stain demonstrating yeasts and hyphae prior to culture, while urine cultures were included only if they yielded ≥100,000 CFU/mL. Identification and susceptibility testing were performed using the VITEK 2 system, with results interpreted using CLSI breakpoints and ECVs.

Among 266 patients with Candida infections, invasive candidiasis predominated in those aged ≥60 years (66.4%). Candida albicans (21.7%) and Candida tropicalis (13.5%) were more frequent in females, while Candida parapsilosis (13.2%) and Candida glabrata (5.3%) were more common in males. Blood and CSF samples strongly correlated with invasive disease and underlying risk factors. C. albicans was linked to infection-related conditions (13.9%), malignancy (9.0%), and cardiovascular disease (6.8%). C. parapsilosis(23.3%) and C. tropicalis (20.7%) were frequently associated with infection, malignancy, and metabolic disorders. C. glabrata (7.5%), noted for antifungal resistance, was isolated in patients with direct infections (3.4%) and malignancies (1.9%). Among azoles, fluconazole demonstrated greater susceptibility against Candida species, requiring lower concentrations for inhibition, despite a higher resistance rate (13.22%) compared to voriconazole (8.95%). Among echinocandins, micafungin showed better susceptibility than caspofungin. Amphotericin B demonstrated the highest overall susceptibilit y (93 –10 0%), though MICs approached ECV limits. Most susceptible MIC values were fluconazole 0.5 μg/mL for C. albicans and C. parapsilosis, 1.0 μg/mL for C. tropicalis; voriconazole and caspofungin 0.12 μg/mL; micafungin 0.06 μg/mL; amphotericin B 0.5 μg/mL; and flucytosine

These findings support a species-specific, risk-adapted approach to antifungal therapy, incorporating demographic and clinical variables. Continuous surveillance of invasive candidiasis prevalence and antifungal MIC trends, with periodic breakpoint updates, is crucial to preserve therapeutic efficacy. Effective management of multidrug-resistant Candidainfections also requires close collaboration between clinicians and pharmacists, as well as the development of new dosing strategies based on pharmacokinetic/pharmacodynamic (PK/PD) principles.

OBJECTIVE

To determine the prevalence of rectal colonization with carbapenem-resistant organisms (CRO) among PGH neonatal intensive care unit (NICU) patients.

A prospective single-center observational study conducted over a 1-month period included all NICU 3 and cohort area patients admitted on April 24, 2024. Rectal swabs were collected for multidrug-resistant organism (MDRO) screening and repeated weekly for 1 month while admitted. Swabs were inoculated on chromogenic media, and isolates were identified and tested for antimicrobial sensitivity by disk diffusion. Clinical characteristics and outcomes were collected for 30 days from initial MDRO screening. Descriptive statistics were used to summarize the data.

The point prevalence of CRO colonization was 37% (14 of 38) at initial screening. There were 14 incident colonizations, hence the 4-week period prevalence of CRO colonization was 72.5% (29 of 40). The patients were mostly very preterm, very low birth weight neonates, majority were tested within the first 2 weeks of life, and half were exposed to meropenem at initial screening. Nosocomial infection developed in 29% and 64%, and 30-day mortality rate was 8% and 21% among initially non-CRO-colonized and CRO-colonized patients respectively. Despite high CRO colonization, no culture-proven CRO infection was observed. Surveillance screening documented persistent CRO colonization in 37%, but no decolonization. Escherichia coli, Klebsiella spp. and Serratia spp. were the most common colonizers.

The high prevalence of rectal CRO colonization in the NICU emphasizes the burden of antimicrobial resistance, but despite the high CRO colonization, no CRO infection was documented from the limited sample and study period.

BACKGROUND AND OBJECTIVE

Antimicrobial resistance (AMR) is a leading global public health concern as it resulted in more difficult-to-treat infections and fatalities. In the Philippines, drug-resistant E. coli, including multidrug-resistant (MDR), extended-spectrum beta-lactamase (ESBL)-producing, carbapenemase-producing carbapenem-resistant (CP-CR) E. coli, have been isolated from common food animals, increasing the risk of cross-contamination between humans, animals, and the environment. However, there is a lack of data on the distribution of E. coli in chicken meat in public wet markets. This study aims to describe the AMR profile of E. coli in raw chicken meat from retail stalls in a selected wet market in Manila City.

This quantitative descriptive study characterized the AMR profile of E. coli isolated from 25 raw chicken meat samples from a wet market in Manila City. Antimicrobial susceptibility was determined through disk diffusion method against 23 antimicrobial agents in 16 antimicrobial classes. MDR E. coli were identified based on the resistance patterns. ESBL- and carbapenemase-producing capacities of the bacteria were tested through double disk synergy test and modified carbapenem inactivation method, respectively.

Twenty-four out of 25 (96%) chicken samples contained E. coli isolates. Of these, 23 (96%) were classified as MDR. High resistance rates were observed against ampicillin (92%), tetracycline (88%), trimethoprim-sulfamethoxazole (83%), chloramphenicol (79%), ampicillin-sulbactam (75%), amoxicillin-clavulanic acid (67%), fosfomycin (67%), and streptomycin (54%). The majority of the E. coli isolates were still susceptible to a wide range of selected antimicrobial agents, including carbapenems (100%), ceftriaxone (100%), cefepime (100%), cefuroxime (96%), cefotaxime (96%), ceftazidime (96%), piperacillin-tazobactam (96%), aztreonam (96%), cefoxitin (92%), and nitrofurantoin (83%), among others. Meanwhile, none of the 24 isolated E. coli samples were classified as ESBL- and CP-CR E. coli.

Among the 25 chicken samples, 24 E. coli colonies were isolated that exhibited 0% to 92% resistance rates against selected antimicrobial agents. Most isolates were classified as MDR, but none were considered ESBLand CP-CR E. coli. This study suggests that chickens in wet markets can potentially serve as reservoir hosts for drugresistance genes, which could transfer to other bacteria and contaminate humans, animals, and the environment within the food production and supply chain. These findings emphasize the need for AMR surveillance and strategies to combat AMR in the Philippines through the One Health approach.

INTRODUCTION

Burn wound infection is a significant risk factor in the morbidity and mortality of burn wound patients. Previous studies in our institution showed bacterial colonization in burn patients seen beyond 24 hours post-injury. The microbiological profile of burn wounds seen within 24 hours, including the presence and risk factors for wound colonization, has not been determined in our Burn Center.

To identify the presence and risk factors for burn wound colonization in burn patients seen less than 24 hours after injury and determine the microbiological profile and antibiotic susceptibility patterns in colonized burn wounds.

One hundred eighty-nine burn patients who were seen at and admitted to the UP Philippine General Hospital ATR Burn Center within 24 hours of the burn injury from June 2021 until July 2023 were included in the study. Demographic and clinical data were collected upon admission. A total of 635 swab samples were collected from 189 patients and were sent for identification of aerobic organisms by standard culture methods and antibiotic sensitivity tests using the Kirby-Bauer disc diffusion method. Association of patient characteristics (area of injury, time received post-injury, previous hospital care, place of injury, percent burn injury, etiology, mode of transport, and type of dressing prior to admission) were determined using Chi square test of independence.

Out of 189 burn patients seen within 24 hours after injury included in the study, 58.73% (n = 111) of patients, and 49.29% (n = 313) of swabs showed bacterial colonization. Burn wound colonization was associated with area of injury/body region (χ2 5 = 16.29, p = .0061), time received post-injury (χ2 3 = 24.62, p < 0.0001, post hoc Fisher’s test for 6-12 hours vs. within the first 6 hours: p < 0.0001), place of burn injury (χ2 2 = 18.17, p = 0.0001, post hoc Fisher’s test work vs. home: p = 0.0006, work vs. outdoors: p = 0.0015), percent burn injury (χ2 4 = 21.40, p = 0.0003, post hoc Fisher’s test 25-49% vs. 0-9%: p = 0.004, 50-75% vs. 0-9%: p = 0.002), and etiology of burn injury (χ2 2 = 37.05, p < 0.0001, post hoc Fisher’s test scald vs. flame: p = 0.0012, electrical vs. flame: p < .0001). From 313 positive samples, 357 isolates were identified. Staphylococcus (58.8%) was the most common organism isolated. It was noted that out of the total isolates, 15 (4.2%) were identified to be methicillin-resistant S. aureus (MRSA) while 5 isolates (1.4%) were methicillin-resistant S. epidermidis (MRSE). Streptococcus (10.4%) and Acinetobacter (6.2%) were the second and third most common organisms, respectively. Other groups identified were Aeromonas, Bacillus, Enterobacter, Pseudomonas, Klebsiella, and diphtheroids. Frequency of bacterial isolates differed across body regions, time received post-injury, percent burn injury, and etiology of burn injury. Resistance to one antibiotic was observed in 36.84%, 6.25%, and 63.64% of Staphylococcus, Streptococcus, and Acinetobacter isolates tested, respectively. Resistance to more than 1 antibiotic was observed in 48.68% of Staphylococcus isolates and 50.0% of Streptococcus isolates tested. Among the 51 S. aureus isolates, 29.1% were methicillin-resistant S. aureus (MRSA).

In burn patients seen within 24 hours after injury, about half of burn wounds and more than half of patients showed the presence of microbial growth. Potential risk factors for positive microbial growth in a burn wound during this timeframe were area of injury/ body region, place of injury, time received post-injury, percent TBSA burn, and etiology of burn injury. The most common isolate was Staphylococcus spp. More than half of Staphylococcus isolates showed antibiotic resistance, with a significant number showing multidrug resistance. More than a quarter of S. aureus isolates were methicillin-resistant S. aureus (MRSA). These results suggest that bacterial isolates can colonize burn wounds even within 24 hours post-injury and may exhibit antibiotic resistance.