INTRODUCTION: The rising rate of adolescent suicide, and the burden of self-harm and mental health disorders, pose significant threats to Singapore's future health outcomes and human potential. This study sought to examine the risk profile and healthcare utilisation patterns of Singaporean adolescents who presented to the emergency department (ED) for suicidal or self-harm behaviour. METHOD: A retrospective review of medical records for patients aged 10 to 19 years who visited Singapore's KK Women's and Children's Hospital ED for suicidal or self-harm attempts from January to December 2021 was conducted. RESULTS: A total of 221 patients were identified, with a predominance of female patients (85.5%) over males (14.5%). The mean age was 14.2 ± 1.4 years. Intentional drug overdose (52.0%) was the most commonly used method. Significantly more females presented for intentional paracetamol overdose (46.6% versus [vs] 28.1%, P=0.049), whereas jumping from a height was more common among males (18.8% vs 5.8%, P=0.022). The most frequently observed mental health challenges were stress-related and emotional coping difficulties (50.7%), followed by mood and anxiety symptoms (53.4%). A history of self-harm and suicidal behaviours were the most common psychosocial risk factors. Within the year prior to their ED presentation, 15.4% had accessed healthcare services for mild medical ailments, 19.5% for medically unexplained symptoms, and 17.2% for previous self-harm or suicide attempts. CONCLUSION Most cases involved psychosocial and emotional regulation difficulties, some of which displayed sex-specific patterns, rather than complex psychiatric disorders. The identified predictive factors can help inform Singapore's National Mental Health and Well-being Strategy, to guide targeted and transdiagnostic interventions in schools and community settings.
Humans ; Adolescent ; Singapore/epidemiology* ; Female ; Male ; Suicide, Attempted/psychology* ; Emergency Service, Hospital/statistics & numerical data* ; Self-Injurious Behavior/psychology* ; Retrospective Studies ; Child ; Young Adult ; Drug Overdose/epidemiology* ; Risk Factors ; Acetaminophen/poisoning* ; Patient Acceptance of Health Care/statistics & numerical data* ; Sex Factors

Parkinson's disease (PD) is a common neurodegenerative disorder mainly related to mitochondrial dysfunction of dopaminergic neurons in the midbrain substantia nigra. This study aimed to investigate the effects of exercise preconditioning on motor deficits and mitochondrial function in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model. Eight-week-old male C57BL/6J mice were randomly divided into four groups: sedentary + saline (SS), sedentary + MPTP (SM), exercise + saline (ES), and exercise + MPTP (EM) groups. Mice in the ES and EM groups received 4 weeks of treadmill training, and then SM and EM groups were treated with MPTP for 5 days. Motor function was assessed by behavioral tests, and morphological and functional changes in dopaminergic neurons and mitochondria in the substantia nigra of the midbrain were evaluated using immunohistochemistry, Western blot, and transmission electron microscopy technology. The results showed that, compared with the SM group, the EM group exhibited significantly improved motor ability, up-regulated protein expression levels of tyrosine hydroxylase (TH) and dopamine transporter (DAT) in the midbrain, and down-regulated protein expression of α-synuclein (α-Syn) in the mitochondria of substantia nigra. Compared with the SM group, the EM group showed up-regulated protein expression levels of mitochondrial fusion proteins, including optical atrophy protein 1 (OPA1) and mitofusin 2 (MFN2), and biogenesis-related proteins, including peroxisome proliferator activated receptor gamma coactivator 1α (PGC-1α) and mitochondrial transcription factor A (TFAM), while the protein expression levels of dynamin-related protein 1 (DRP1) and mitochondrial fission protein 1 (FIS1) were significantly down-regulated. Compared with the SM group, the EM group showed significantly reduced damage to substantia nigra mitochondria, restored mitochondrial membrane potential and ATP production, and decreased levels of reactive oxygen species (ROS). These results suggest that 4-week treadmill pre-training can alleviate MPTP-induced motor impairments in PD mice by improving mitochondrial function, providing a theoretical basis for early exercise-based prevention of PD.
Animals ; Male ; Physical Conditioning, Animal/physiology* ; Mice ; Mice, Inbred C57BL ; Mitochondria/physiology* ; Dopaminergic Neurons ; MPTP Poisoning/physiopathology* ; Substantia Nigra ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine

OBJECTIVES: To determine the neuroprotective effects of berberine hydrochloride (BBR) against lead-induced injuries on the hippocampus of rats. METHODS: Wistar rats were exposed orally to doses of 100 and 500 ppm lead acetate for 1 and 2 months to develop subchronic and chronic lead poisening models, respectively. For treatment, BBR (50 mg/kg daily) was injected intraperitoneally to rats poisoned with lead. At the end of the experiment, the spatial learning and memory of rats were assessed using the Morris water maze test. Hippocampal tissue changes were examined by hematoxylin and eosin staining. The activity of antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase, and malondialdehyde levels as parameters of oxidative stress and antioxidant status of the hippocampus were evaluated. RESULTS: BBR reduced cognitive impairment in rats exposed to lead (P<0.05 or P<0.01). The resulting biochemical changes included a decrease in the activity of antioxidants and an increase in lipid peroxidation of the hippocampus of lead-exposed rats (P<0.05 or P<0.01), which were significantly modified by BBR (P<0.05). BBR also increased the density of healthy cells in the hippocampus of leadexposed rats (P<0.05). Significant changes in tissue morphology and biochemical factors of the hippocampus were observed in rats that received lead for 2 months (P<0.05). Most of these changes were insignificant in rats that received lead for 1 month. CONCLUSION BBR can improve oxidative tissue changes and hippocampal dysfunction in lead-exposed rats, which may be due to the strong antioxidant potential of BBR.
Animals ; Hippocampus/pathology* ; Rats, Wistar ; Antioxidants/pharmacology* ; Berberine/therapeutic use* ; Cognition/drug effects* ; Male ; Lead Poisoning/metabolism* ; Chronic Disease ; Oxidative Stress/drug effects* ; Maze Learning/drug effects* ; Rats ; Lipid Peroxidation/drug effects* ; Malondialdehyde/metabolism*

OBJECTIVES: The neurotoxicity of carbon monoxide (CO) to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Our previous study found that retinoic acid (RA) can suppress the neurotoxic effects of CO. This study further explores, in vivo and in vitro, the molecular mechanisms by which RA alleviates CO-induced central nervous system damage. METHODS: A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO, and a DEACMP animal model was established in adult Kunming mice. Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin V/propidium iodide (PI) double staining. The transcriptional and protein expression of each gene was detected using real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Long noncoding RNA (lncRNA) SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes. In DEACMP mice, SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression. RESULTS: RA at 10 and 20 μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes, downregulation of SNHG15 and LINGO-1, and upregulation of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) (all P<0.05). Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity (all P<0.05). Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels (all P<0.05). Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP (all P<0.05). CONCLUSIONS RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes, thereby reducing central nervous system injury and exerting neuroprotective effects. LncRNA SNHG15 and LINGO-1 are key molecules mediating RA-induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway. These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
Animals ; RNA, Long Noncoding/physiology* ; Brain-Derived Neurotrophic Factor/genetics* ; Carbon Monoxide Poisoning/complications* ; Mice ; Tretinoin/pharmacology* ; Nerve Tissue Proteins/metabolism* ; Membrane Proteins/metabolism* ; Apoptosis/drug effects* ; Hippocampus/cytology* ; Receptor, trkB/metabolism* ; Neurons/drug effects* ; Male ; Brain Diseases/etiology* ; Oligodendroglia/drug effects* ; Signal Transduction ; Cell Line

Nitrogen narcosis is a neurological syndrome that manifests when humans or animals encounter hyperbaric nitrogen, resulting in a range of motor, emotional, and cognitive abnormalities. The anterior cingulate cortex (ACC) is known for its significant involvement in regulating motivation, cognition, and action. However, its specific contribution to nitrogen narcosis-induced hyperlocomotion and the underlying mechanisms remain poorly understood. Here we report that exposure to hyperbaric nitrogen notably increased the locomotor activity of mice in a pressure-dependent manner. Concurrently, this exposure induced heightened activation among neurons in both the ACC and dorsal medial striatum (DMS). Notably, chemogenetic inhibition of ACC neurons effectively suppressed hyperlocomotion. Conversely, chemogenetic excitation lowered the hyperbaric pressure threshold required to induce hyperlocomotion. Moreover, both chemogenetic inhibition and genetic ablation of activity-dependent neurons within the ACC reduced the hyperlocomotion. Further investigation revealed that ACC neurons project to the DMS, and chemogenetic inhibition of ACC-DMS projections resulted in a reduction in hyperlocomotion. Finally, nitrogen narcosis led to an increase in local field potentials in the theta frequency band and a decrease in the alpha frequency band in both the ACC and DMS. These results collectively suggest that excitatory neurons within the ACC, along with their projections to the DMS, play a pivotal role in regulating the hyperlocomotion induced by exposure to hyperbaric nitrogen.
Animals ; Gyrus Cinguli/drug effects* ; Male ; Mice, Inbred C57BL ; Locomotion/drug effects* ; Neurons/drug effects* ; Mice ; Nitrogen/toxicity* ; Inert Gas Narcosis/physiopathology* ; Corpus Striatum/physiopathology*

Acute carbon monoxide poisoning (ACMP) is one of the most common gas poisonings in the emergency department, with tens of thousands of people seeking medical attention for carbon monoxide (CO) poisoning each year. The severity of poisoning is dependent upon environmental and human factors, with hypoxia and oxidative stress being important mechanisms of cardiac toxicity induced by CO. Myocardial involvement is common in moderate to severe ACMP, including myocardial injury, myocardial infarction, arrhythmia, and sudden death, which are associated with a high risk of death. Ferroptosis is a cell death mechanism caused by iron-dependent lipid peroxidation (LPO), although ferroptosis has been shown to play a critical role in various cardiovascular diseases, the potential mechanism by which it contributes to ACMP-induced myocardial injury is unclear. This review discusses the established link between ferroptosis and cardiovascular disease and summarizes the potential role of ferroptosis in ACMP-induced myocardial injury and the detrimental effects of ACMP on the heart. Elucidating these mechanisms could guide the development of novel therapeutic strategies that target ferroptosis to mitigate ACMP-induced myocardial injury. This review aims to provide a theoretical foundation for future research on the potential use of ferroptosis as a therapeutic target for ACMP-induced myocardial injury.
Humans ; Carbon Monoxide Poisoning/complications* ; Ferroptosis ; Lipid Peroxidation ; Myocardium/pathology* ; Oxidative Stress

OBJECTIVE: To investigate whether auraptene (AUR) exerts a protective effect on acute diquat (DQ)-induced liver injury in mice and explore its underlying mechanisms. METHODS: Forty SPF-grade healthy male C57BL/6 mice were randomly divided into normal control group (Control group), DQ poisoning model group (DQ group), AUR treatment group (DQ+AUR group), and AUR control group (AUR group), with 10 mice in each group. The DQ poisoning model was established via a single intraperitoneal injection of 40 mg/kg DQ aqueous solution (0.5 mL); Control group and AUR group received an equal volume of pure water intraperitoneally. Four hours post-modeling, DQ+AUR group and AUR group were administered 0.5 mg/kg AUR aqueous solution (0.2 mL) by gavage once daily for 7 consecutive days, while Control group and DQ group received pure water. Blood and liver tissues were collected after anesthesia on day 7. Liver ultrastructure was observed by transmission electron microscopy. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured via enzyme-linked immunosorbent assay (ELISA). Hepatic glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were detected using WST-1, thiobarbituric acid (TBA), and enzymatic reaction methods, respectively. Protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues was analyzed by Western blotting. RESULTS: Transmission electron microscopy revealed that mitochondria in the Control group exhibited mild swelling, uneven distribution of matrix, and a small number of cristae fractures. In the AUR group, mitochondria showed mild swelling, with no obvious disruption of cristae structure. In the DQ group, mitochondria demonstrated marked swelling and increased volume, matrix dissolution, loss and fragmentation of cristae, and extensive vacuolization. In contrast, the DQ+AUR group showed significantly reduced mitochondrial swelling, volume increase, matrix dissolution, cristae loss and fragmentation, and vacuolization compared to the DQ group. Compared with the DQ group, the DQ+AUR group exhibited significantly lower serum AST levels (U/L: 173.45±23.60 vs. 255.33±41.51), ALT levels (U/L: 51.77±21.63 vs. 100.70±32.35), and hepatic MDA levels (μmol/g: 12.40±2.76 vs. 19.74±4.10), along with higher hepatic GSH levels (mmol/g: 37.65±14.95 vs. 20.58±8.52) and SOD levels (kU/g: 124.10±33.77 vs. 82.81±22.00), the differences were statistically significant (all P < 0.05). Western blotting showed upregulated Nrf2 expression (Nrf2/β-actin: 0.87±0.37 vs. 0.53±0.22) and HO-1 expression (HO-1/β-actin: 1.06±0.22 vs. 0.49±0.08), and downregulated Keap1 expression (Keap1/β-actin: 0.82±0.12 vs. 1.52±0.76) and activated caspase-9 expression (activated caspase-9/β-actin: 1.16±0.28 vs. 1.71±0.30) in the DQ+AUR group compared to the DQ group (all P < 0.05). CONCLUSION AUR attenuates DQ-induced acute liver injury in mice by activating the Keap1/Nrf2 signaling pathway.
Animals ; Male ; Mice ; Mice, Inbred C57BL ; Liver/pathology* ; Chemical and Drug Induced Liver Injury/drug therapy* ; Diquat/poisoning* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Apoptosis ; Coumarins

Sodium nitrite (SN, NaNO2) is a water-soluble, white-yellow crystalline powder with broad applications in food preservation, automotive maintenance, and animal control. It is a strong oxidizing agent that can oxidize hemoglobin iron (Fe) to its oxidized state, leading to methemoglobin formation. An increasing trend of suicide cases by SN ingestion has been reported globally following its popularization in online suicide forums providing detailed instructions of its use solely or as part of a “suicide kit.” We report a case of a 21-year-old male who was found continuously vomiting, with blood per orem and cyanosis of the mouth and digits. Within minutes of the onset of symptoms, the patient lost consciousness and was pronounced dead on arrival at the nearest emergency room. Autopsy findings showed lip erosions, hemorrhage, and perioral and peripheral cyanosis. Internal examination showed characteristic bright red muscle discoloration, dark brown arterial blood, red-brown congested visceral organs, and hyperemic esophageal and gastric mucosa. Methemoglobin studies from sampled arterial blood showed elevated levels (17.5%). Further investigation of the decedent’s belongings, social media posts, and recent online purchases reinforced the intentional sodium nitrite ingestion. While there are plenty of reported SN poisoning in suicide cases internationally, limited reports have been published locally. Death by SN poisoning is preventable with Methylene blue. The role of forensic pathologists through autopsy may be the last chance to detect such cases. The lack of systemic death investigation, experts, and local laboratories to reliably detect the signs of SN poisoning may have affected the low detection rate of cases locally. Further reporting of cases can raise the awareness of medical professionals that is fundamental to the ultimate saving of lives.

Acquired perforating collagenosis (APC) is a rare dermatological condition characterized by the spontaneous eruption of skin-colored or erythematous papules or nodules that eventually ulcerate and exude collagenous material. The exact etiology of APC remains unclear, although various triggers, including infections, medications, autoimmune diseases, and trauma, have been implicated.

This case report presents a 63-year-old female with a history of diabetes who developed erythematous papules and plaques topped with thick, yellowish, hyperkeratotic, adherent crusts on the upper back following an insect bite. Histopathological examination confirmed the diagnosis of APC, characterized by a cup-shaped invagination in the epidermis containing degenerated collagen bundles and basophilic material. Masson-trichrome staining showed transepidermal elimination of the collagen fibers. Patient was initially prescribed tretinoin 0.1% cream to be applied 2x a day. However, patient was not able to apply prescribed medications. Interestingly, without any specific treatment, the patient’s symptoms gradually improved over 3 months and eventually resolved completely.

This case report highlights the spontaneous resolution of APC in a patient following an insect bite. While most cases of APC require medical intervention, this case demonstrates the potential for spontaneous healing in certain individuals. Further research is needed to understand the factors that influence the course of APC and to identify potential predictors of spontaneous resolution.

Copper sulfate is a frequently used copper compound in laboratory settings, with instances of poisoning being uncommon. A study conducted by the American Association of Poison Control Centers' National Poison Data System found that only 140 individuals were exposed to copper compounds over the course of a year, with five cases being intentional (Gummin et al., 2023). Severe poisoning from copper sulfate can result in isolated gastrointestinal injury (Galust et al., 2023), intravascular hemolysis (Adline et al., 2024), rhabdomyolysis (Richards et al., 2020), and other symptoms documented in the literature. However, there have been no reports of long-term uncontrolled hyperglycemia in patients with copper sulfate poisoning. This case study documents the treatment approach for a patient with unexplained, long-term, uncontrolled hyperglycemia, alongside multiple organ dysfunction resulting from intentional ingestion of a large dose of copper sulfate. This case report details the long-term complications in a patient's recovery from acute copper sulfate, highlighting the significance of ongoing monitoring and intervention.
Humans ; Copper Sulfate/poisoning* ; Hyperglycemia/chemically induced* ; Multiple Organ Failure/therapy*