Simultaneous detection of SO2 and viscosity in drug-induced inflammation in live cells and zebrafish.

The viscosity within cells is a crucial microenvironmental factor, and sulfur dioxide (SO2 ) has essential functions in regulating cellular apoptosis and inflammation. Some evidence has been confirmed that changes in viscosity and overexposure of SO2 within the cell may cause detrimental effects including, but not limited to, respiratory and cardiovascular illnesses, inflammation, fatty liver, and various types of cancer. Therefore, precise monitoring of SO2 and viscosity in biological entities holds immense practical importance. Therefore, in this research, we developed a versatile fluorescent TCF-Cou that enables the dual detection of SO2 and viscosity in the living system. Probe TCF-Cou possessed a response to viscosity and SO2 through red and green emissions. The alteration of SO2 and viscosity levels in live cells and zebrafish were also monitored using probe TCF-Cou. We hope that this fluorescent probe could be a potential tool for revealing the related pathological and physiological processes through monitoring the changes in SO2 and viscosity.

Fluorescent dyes based on rhodamine derivatives for bioimaging and therapeutics: recent progress, challenges, and prospects.

Since their inception, rhodamine dyes have been extensively applied in biotechnology as fluorescent markers or for the detection of biomolecules owing to their good optical physical properties. Accordingly, they have emerged as a powerful tool for the visualization of living systems. In addition to fluorescence bioimaging, the molecular design of rhodamine derivatives with disease therapeutic functions (e.g., cancer and bacterial infection) has recently attracted increased research attention, which is significantly important for the construction of molecular libraries for diagnostic and therapeutic integration. However, reviews focusing on integrated design strategies for rhodamine dye-based diagnosis and treatment and their wide application in disease treatment are extremely rare. In this review, first, a brief history of the development of rhodamine fluorescent dyes, the transformation of rhodamine fluorescent dyes from bioimaging to disease therapy, and the concept of optics-based diagnosis and treatment integration and its significance to human development are presented. Next, a systematic review of several excellent rhodamine-based derivatives for bioimaging, as well as for disease diagnosis and treatment, is presented. Finally, the challenges in practical integration of rhodamine-based diagnostic and treatment dyes and the future outlook of clinical translation are also discussed.

An ER-targeted, Viscosity-sensitive Hemicyanine Dye for the Diagnosis of Nonalcoholic Fatty Liver and Photodynamic Cancer Therapy by Activating Pyroptosis Pathway.

The concept of molecular design, integrating diagnostic and therapeutic functions, aligns with the general trend of modern medical advancement. Herein, we rationally designed the smart molecule ER-ZS for endoplasmic reticulum (ER)-targeted diagnosis and treatment in cell and animal models by combining hemicyanine dyes with ER-targeted functional groups (p-toluenesulfonamide). Owing to its ability to target the ER with a highly specific response to viscosity, ER-ZS demonstrated substantial fluorescence turn-on only after binding to the ER, independent of other physiological environments. In addition, ER-ZS, being a small molecule, allows for the diagnosis of nonalcoholic fatty liver disease (NAFLD) via liver imaging based on high ER stress. Importantly, ER-ZS is a type I photosensitizer, producing O2 ⋅- and ⋅OH under light irradiation. Thus, after irradiating for a certain period, the photodynamic therapy inflicted severe oxidative damage to the ER of tumor cells in hypoxic (2 % O2 ) conditions and activated the unique pyroptosis pathway, demonstrating excellent antitumor capacity in xenograft tumor models. Hence, the proposed strategy will likely shed new light on integrating molecular optics for NAFLD diagnosis and cancer therapy.

Reversible Chemical Protein Modification to Endogenous Glutathione and Its Utilities in the Manufacture of Transcellular Pro-Enzymes.

Proteins have been perceived as being an intriguing modality of therapeutics for the treatment of intractable diseases in view of their superlative precision and versatility. Nonetheless, proteins' intrinsic characters, particularly their being hydrophilic macromolecules with unmethodical charges, have imposed the exceeding challenge of seeking transcellular trafficking into cells' interiors. To circumvent this drawback, we have attempted to employ triple-functional amine-reactive 4-(2-((2-(((4-nitrophenoxy)carbonyl)oxy)ethyl)disulfaneyl)ethoxy)-4-oxobutanoic acid for the efficient incorporation of the anionic carboxyl moiety into amine-enriched enzymes, resulting in overall negatively charged pro-enzymes. The resulting pro-enzymes could be readily electrostatically assembled with cationic species [for instance: block copolymers of poly(ethylene glycol)-polylysine] into core-shell architectural delivery nanoparticles for their facilitated endocytosis into cells. Noteworthy is the aforementioned carboxylation chemistry designed to allow facile reversal of the pro-enzymes to the original amine groups due to the thiolysis of intermediate disulfide linkage for subsequent cascade reactions in response to the cytosol-enriched glutathione. Therefore, cytosol-selective structural disassembly for the liberation and activation of the pro-enzymes was accomplished. Our subsequent investigations utilizing ribonuclease A and catalase as the model enzymes demonstrated appreciable transcellular transportation of the active enzymes to the cell interiors, exerting overwhelming cytotoxic potencies and H2O2 scavenging capacities, respectively. Hence, we reported an unprecedented redox-stimulated charge reversal strategy in engineering cytosol-activatable pro-enzymes, manifesting a simple and efficient approach in the manufacture of transcellular proteinic therapeutics, which should be highlighted to promote their wide availability for use with diverse functional proteins as molecular biological tools and precision therapeutics.

Bioresorbable Depot for Sustained Release of Immunostimulatory Resiquimod in Suppressing Both Primary Triple-Negative Breast Tumors and Metastatic Occurrence.

In light of immune facilities trafficking toward the pathological sites along upward gradient of immunostimulatory cytokines, a localized resiquimod (Toll-like receptor 7/8 agonist) release depot was manufactured for pursuit of precision immunostimulation toward intractable triple-negative breast carcinoma. In principle, resiquimod/poly(lactic-co-glycolic acid) microspheres were fabricated and embedded into injectable and biodegradable poly(ethylene glycol) (PEG)-based hydrogel. The subsequent investigations approved persistent retention of immunostimulatory resiquimod in tumors upon peritumoral administration, which consequently led to localized and consistent secretion of immunostimulatory cytokines. Initially, not only innate tumor phagocytosis but also adaptive antitumor immunities were successfully cultivated for in situ suppression of the growth of primary solid tumors, more importantly, capable of inhibiting distant pulmonary metastasis, as evidenced by observation of enormous lymphocytes selectively gathering in the pulmonary artery. Hence, our presented study provided an important clinical indication of using immunostimulatory drugs to activate potent innate and adaptive antitumor immunities for precision antitumor therapy. Further immunomodulatory strategies, such as checkpoint blockage and tumor immunogenicity, could also be complementary for development of advanced antitumor immunotherapeutics in treatment of a number of intractable tumors.

Expression of a novel PSK-encoding gene from soybean improves seed growth and yield in transgenic plants.

MAIN CONCLUSION: Expression of GmPSKγ1 , a novel PSK-encoding gene from soybean, increases seed size and yield in transgenic plants by promoting cell expansion. Phytosulfokine-α (PSK-α), a sulfated pentapeptide hormone with the sequence YIYTQ, plays important roles in many aspects of plant growth and development. In this study, we identified a pair of putative precursor genes in soybean, GmPSKγ1 and -2, encoding a PSK-like peptide: PSK-γ. Similar to PSK-α in amino acid composition, the sequence of PSK-γ is YVYTQ, and the tyrosines undergo sulfonylation. Treatment of Arabidopsis seedlings with synthetic sulfated PSK-γ significantly enhanced root elongation, indicating that PSK-γ might be a functional analog of PSK-α. Expression pattern analysis revealed that the two GmPSKγ genes, especially GmPSKγ1, are primarily expressed in developing soybean seeds. Heterologous expression of GmPSKγ1 under the control of a seed-specific promoter markedly increased seed size and weight in Arabidopsis, and this promoting effect of PSK-γ on seed growth was further confirmed in transgenic tobacco constitutively expressing GmPSKγ1. Cytological analysis of transgenic Arabidopsis seeds revealed that PSK-γ promotes seed growth by inducing embryo cell expansion. In addition, expression analysis of downstream candidate genes suggested that PSK-γ signaling might regulate cell wall loosening to promote cell expansion in Arabidopsis seeds. Overall, our results shed light on the mechanism by which PSK-γ promotes seed growth, paving the way for the use of this new peptide for biotechnological improvement of crop seed/grain size and yield.

A Highly Selective Naphthalimide-Based Chemosensor: "Naked-Eye" Colorimetric and Fluorescent Turn-On Recognition of Al3+ and Its Application in Practical Samples, Test Paper and Logic Gate.

A novel naphthalimide-based colorimetric and fluorescent turn-on chemosensor for Al3+ was synthesized and characterized with spectroscopic techniques. In MeOH solution, BPAM showed high selectivity and sensitivity to Al3+ by a 60-fold fluorescence enhancement and blue-shift absorption with visible color changes attributed to the contribution of chelation enhanced fluorescence (CHEF) and inhibition of intramolecular charge transfer (ICT). A 1:1 BPAM-Al3+ complex confirmed by job's plot and HRMS with a binding constant of 6.37 × 104 M- 1, and the detection limit for Al3+ was as low as 1.59 × 10- 7 M. BPAM was successfully applied in real sample detection and assessing the existence of Al3+ by a colorimetric method on filter paper. Furthermore, the fluorescent signals of BPAM were designed to construct an INHIBIT molecular logic gate.

Two HSP90 genes in mandarin fish Siniperca chuatsi: identification, characterization and their specific expression profiles during embryogenesis and under stresses.

HSP90 plays important roles in multiple cellular stress responses. Here, two cytoplasmic HSP90 isoforms, ScHSP90α and ScHSP90ß, were identified from Siniperca chuatsi. Their cDNA and gDNA structures, amino acid sequence features, and sequence identities and phylogenetic analysis with other species were described. Their expression profiles during embryonic development in different tissues and under stressful conditions were analyzed using real-time quantitative PCR. During embryogenesis, transcripts of both genes were detected at low levels during the early developmental stages and were up-regulated from appearance of myomere for ScHSP90a and closure of blastopore for ScHSP90ß. ScHSP90α showed a tissue-specific variation with high expression in ovary and brain under non-stressed conditions, while ScHSP90ß was ubiquitously highly expressed in different tissues. Acute heat shock resulted in a strong up-regulation of ScHSP90α in heart, liver, and head kidney, while it only weakly induced ScHSP90ß in these tissues. ScHSP90α was also markedly induced in liver in a time-dependent manner under hypoxia, while the expression of ScHSP90ß was not affected by hypoxia. Additionally, Aeromonas hydrophila infection markedly augmented ScHSP90α in head kidney and spleen and mildly up-regulated ScHSP90ß in spleen, while suppressing ScHSP90ß in head kidney. These results suggest that ScHSP90α and ScHSP90ß are differently involved in embryogenesis and under different environmental conditions including high temperature, hypoxia, and bacterial infection. This study will benefit to further clarify the roles of fish HSP90 isoforms in embryogenesis and under stressful conditions and contribute to further study on enhancing stress tolerance and disease resistance of mandarin fish.

Effect of Intermittent Hypoxia and Rimonabant on Glucose Metabolism in Rats: Involvement of Expression of GLUT4 in Skeletal Muscle.

BACKGROUND: Obstructive sleep apnea (OSA) and its main feature, chronic intermit-tent hypoxia (IH) during sleep, is closely associated with insulin resistance (IR) and diabetes. Rimonabant can regulate glucose metabolism and improve IR. The present study aimed to assess the effect of IH and rimonabant on glucose metabolism and insulin sensitivity, and to explore the possible mechanisms. MATERIAL AND METHODS: Thirty-two rats were randomly assigned into 4 groups: Control group, subjected to intermittent air only; IH group, subjected to IH only; IH+NS group, subjected to IH and treated with normal saline; and IH+Rim group, subjected to IH and treated with 10 mg/kg/day of rimonabant. All rats were killed after 28 days of exposure. Then, the blood and skeletal muscle were collected. We measured fasting blood glucose levels, fasting blood insulin levels, and the expression of glucose transporter 4 (GLUT4) in both mRNA and protein levels in skeletal muscle. RESULTS: IH can slow weight gain, increase serum insulin level, and reduce insulin sensitivity in rats. The expressions of GLUT4 mRNA, total GLUT4, and plasma membrane protein of GLUT4 (PM GLUT4) in skeletal muscle were decreased. Rimonabant treatment was demonstrated to improve weight gain and insulin sensitivity of the rats induced by IH. Rimonabant significantly upregulated the expression of GLUT4 mRNA, PM GLUT4, and total GLUT4 in skeletal muscle. CONCLUSIONS: The present study demonstrates that IH can cause IR and reduced expression of GLUT4 in both mRNA and protein levels in skeletal muscle of rats. Rimonabant treatment can improve IH - induced IR, and the upregulation of GLUT4 expression may be involved in this process.

Gram-negative bacteria recognition and photodynamic elimination by Zn-DPA based sensitizers.

The abuse and overuse of antibiotics let drug-resistant bacteria emerges. Antibacterial photodynamic therapy (APDT) has shown outstanding merits to eliminate the drug-resistant bacteria via cytotoxic reactive oxygen species produced by irradiating photosensitizer. However, most of photosensitizers are not effective for Gram-negative bacteria elimination. Herein conjugates of NBS, a photosensitizer, linked with one (NBS-DPA-Zn) or two (NBS-2DPA-Zn) equivalents of zinc-dipicolylamine (Zn-DPA) have been designed to achieve the functional recognition of different bacteria. Due to the cationic character of NBS and metal transfer channel effect of Zn-DPA, NBS-DPA-Zn exhibited the first regent to distinguish P. aeruginosa from other Gram-negative bacteria. Whereas NBS-2DPA-Zn showed broad-spectrum antibacterial effect because the two arm of double Zn-DPA enhanced interactions with anionic membranes of bacteria, led the bacteria aggregation and thus provided the efficacy of APDT to bacteria and corresponding biofilm. In combination with a hydrogel of Pluronic, NBS-2DPA-Zn@gel shows promising clinical application in mixed bacterial diabetic mouse model infection. This might propose a new method that can realize functional identification and elimination of bacteria through intelligent regulation of Zn-DPA, and shows excellent potential for antibacterial application.

Choroidal Vascularity Index and Choroidal Structural Changes in Children With Nephrotic Syndrome.

Purpose: To investigate the choroidal vascularity index (CVI) and choroidal structural changes in children with nephrotic syndrome. Methods: This was a cross-sectional study involving 45 children with primary nephrotic syndrome and 40 normal controls. All participants underwent enhanced depth imaging-optical coherence tomography examinations. An automatic segmentation method based on deep learning was used to segment the choroidal vessels and stroma, and the choroidal volume (CV), vascular volume (VV), and CVI within a 4.5 mm diameter circular area centered around the macular fovea were obtained. Clinical data, including blood lipids, serum proteins, renal function, and renal injury indicators, were collected from the patients. Results: Compared with normal controls, children with nephrotic syndrome had a significant increase in CV (nephrotic syndrome: 4.132 ± 0.464 vs. normal controls: 3.873 ± 0.574; P = 0.024); no significant change in VV (nephrotic syndrome: 1.276 ± 0.173 vs. normal controls: 1.277 ± 0.165; P = 0.971); and a significant decrease in the CVI (nephrotic syndrome: 0.308 [range, 0.270-0.386] vs. normal controls: 0.330 [range, 0.288-0.387]; P < 0.001). In the correlation analysis, the CVI was positively correlated with serum total protein, serum albumin, serum prealbumin, ratio of serum albumin to globulin, and 24-hour urine volume and was negatively correlated with total cholesterol, low-density lipoprotein cholesterol, urinary protein concentration, and ratio of urinary transferrin to creatinine (all P < 0.05). Conclusions: The CVI is significantly reduced in children with nephrotic syndrome, and the decrease in the CVI parallels the severity of kidney disease, indicating choroidal involvement in the process of nephrotic syndrome. Translational Relevance: Our findings contribute to a deeper understanding of how nephrotic syndrome affects the choroid.

Mfn2 regulates mitochondria and mitochondria-associated endoplasmic reticulum membrane function in neurodegeneration induced by repeated sevoflurane exposure.

Repeated sevoflurane exposure in neonatal mice can leads to neuronal apoptosis and mitochondrial dysfunction. The mitochondria are responsible for energy production to maintain homeostasis in the central nervous system. The mitochondria-associated endoplasmic reticulum membrane (MAM) is located between the mitochondria and endoplasmic reticulum (ER), and it is critical for mitochondrial function and cell survival. MAM malfunction contributes to neurodegeneration, however, whether it is involved in sevoflurane-induced neurotoxicity remains unknown. Our study demonstrated that repeated sevoflurane exposure induced mitochondrial dysfunction and dampened the MAM structure. The upregulated ER-mitochondria tethering enhanced Ca2+ transition from the cytosol to the mitochondria. Overload of mitochondrial Ca2+ contributed to opening of the mitochondrial permeability transition pore (mPTP), which caused neuronal apoptosis. Mitofusin 2(Mfn2), a key regulator of ER-mitochondria contacts, was found to be suppressed after repeated sevoflurane exposure, while restoration of Mfn2 expression alleviated cognitive dysfunction due to repeated sevoflurane exposure in the adult mice. These evidences suggest that sevoflurane-induced MAM malfunction is vulnerable to Mfn2 suppression, and the enhanced ER-mitochondria contacts promotes mitochondrial Ca2+ overload, contributing to mPTP opening and neuronal apoptosis. This paper sheds light on a novel mechanism of sevoflurane-induced neurotoxicity. Furthermore, targeting Mfn2-mediated regulation of the MAM structure and mitochondrial function may provide a therapeutic advantage in sevoflurane-induced neurodegeneration.

A comprehensive whole genome database of ethnic minority populations.

China, is characterized by its remarkable ethnical diversity, which necessitates whole genome variation data from multiple populations as crucial tools for advancing population genetics and precision medical research. However, there has been a scarcity of research concentrating on the whole genome of ethnic minority groups. To fill this gap, we developed the Guizhou Multi-ethnic Genome Database (GMGD). It comprises whole genome sequencing data from 476 healthy unrelated individuals spanning 11 ethnic minorities groups in Guizhou Province, Southwest China, including Bouyei, Dong, Miao, Yi, Bai, Gelo, Zhuang, Tujia, Yao, Hui, and Sui. The GMGD database comprises more than 16.33 million variants in GRCh38 and 16.20 million variants in GRCh37. Among these, approximately 11.9% (1,956,322) of the variants in GRCh38 and 18.5% (3,009,431) of the variants in GRCh37 are entirely new and do not exist in the dbSNP database. These novel variants shed light on the genetic diversity landscape across these populations, providing valuable insights with an average coverage of 5.5 ×. This makes GMGD the largest genome-wide database encompassing the most diverse ethnic groups to date. The GMGD interactive interface facilitates researchers with multi-dimensional mutation search methods and displays population frequency differences among global populations. Furthermore, GMGD is equipped with a genotype-imputation function, enabling enhanced capabilities for low-depth genomic research or targeted region capture studies. GMGD offers unique insights into the genomic variation landscape of different ethnic groups, which are freely accessible at https://db.cngb.org/pop/gmgd/ .

Fluorescent protein-based detection of φC31 integrase activity in mammalian cells.

The enzyme φC31 integrase from Streptomyces phage has been documented as functional in mammalian cells and, therefore, has the potential to be a powerful gene manipulation tool. However, the activity of this enzyme is cell-type dependent. The more active mutant forms of φC31 integrase are required. Therefore, a rapid and effective method should be developed to detect the intracellular activity of φC31 integrase. We devised in this study an integrase-inversion cassette that contains the enhanced green fluorescent protein (EGFP) gene and the reverse complementary DsRed gene, which are flanked by attB and reverse complementary attP. This cassette can be inverted by φC31 integrase, thereby altering the fluorescent protein expression. Thus, φC31 integrase activity can be qualitatively or quantitatively evaluated based on the detected fluorescence. Furthermore, this cassette-based method was applied to several cell types, demonstrating that it is an efficient and reliable tool for measuring φC31 integrase activity in mammalian cells.

The Effect of Perceived Environmental Uncertainty on University Students' Anxiety, Academic Engagement, and Prosocial Behavior.

Uncertainty, as the predominant characteristic of the contemporary landscape, poses significant challenges and exerts profound influence on individual decision making and behaviors; however, there remains a limited understanding of its impact on university student behavior. Building upon the uncertainty management theory, this study presents a conceptual framework to investigate the impact of perceived environmental uncertainty on university students' anxiety levels and behaviors, including academic engagement and prosocial behavior. Additionally, our model proposes that the intolerance of uncertainty moderates a mediating effect on anxiety. These hypotheses are empirically tested using a sample of 221 Chinese university students. The results reveal a positive relationship between perceived environmental uncertainty and anxiety among university students; subsequently, anxiety exerts a negative influence on both academic engagement and prosocial behavior. Furthermore, we find that anxiety serves as a psychological mediator between perceived environmental uncertainty and both academic engagement and prosocial behavior. This research also underscores the significance of the intolerance of uncertainty in shaping university students' involvement in academic pursuits when confronted with anxiety stemming from perceived environmental uncertainty. Consequently, these findings have practical implications for facilitating university students' adaptive coping strategies in uncertain contexts and mitigating the negative effects of anxiety on their behavioral responses.

Association between vitamin D concentration and delirium in hospitalized patients: A meta-analysis.

BACKGROUND: Now the occurrence of delirium is more concerning to clinicians and psychiatrists. It has been reported that vitamin D deficiency may be a relevant factor in the development of delirium in hospitalized patients. STUDY OBJECTIVE: To investigate the association between vitamin D concentration and delirium in hospitalized patients. DESIGN: Meta-analysis. METHODS: A systematic literature search was conducted using PubMed, EMBASE, and the Cochrane Library. The primary outcome was the occurrence of delirium in the inpatient setting. Odds ratios (OR) were calculated with random or fixed effects models. RESULTS: In this article, we define the normal range of vitamin D concentrations as greater than 75 nmol / L, 50-75 nmol / L as vitamin D insufficiency, 25-50 nmol / L as vitamin D deficiency, and less than 25 nmol / L as vitamin D severe deficiency. The Results showed that severe vitamin D deficiency (OR: 1.98 [1.41-2.79], P<0.001) and vitamin D deficiency (OR: 1.50 [1.12-2.00], P = 0.006) were more likely to develop delirium than normal vitamin D levels. Subgroup analysis also revealed that low vitamin D concentrations were associated with a higher incidence of delirium, whether the cutoff point was 25 nmol/L (OR: 1.52 [1.40-1.64], P<0.001), 50 nmol/L (OR: 1.47 [1.19-1.82], P<0.001), or 75 nmol/L (OR: 1.54 [1.21-1.96], P<0.001). The included studies scored medium and high on the Newcastle-Ottawa quality assessment scale. CONCLUSION: Compared with normal vitamin D levels, severe vitamin D deficiency and vitamin D deficiency, but not vitamin D insufficiency, are associated with a higher incidence of delirium in hospitalized patients. TRIAL REGISTRATION: This review was registered in the PROSPERO database under identifier CRD42021271347. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021271347.

Prospects of coupled iron-based nanostructures in preclinical antibacterial therapy.

Bacterial infections can threaten human health. Drug-resistant bacteria have become a challenge because of the excessive use of drugs. We summarize the current metallic antibacterial materials, especially Fe-based materials, for efficiently killing bacteria. The possible antibacterial mechanisms of metallic antibacterial agents are classified into interactions with bacterial proteins, iron metabolism, catalytic activity, and combinations of magnetic, photodynamic, and photothermal effects. This review will inspire the development of novel Fe-based antibacterial agents for clinical settings.

Infrared Thermography: Clinical Value for Diagnosing Persistent Somatoform Pain Disorders?

BACKGROUND: Patients with persistent somatoform pain disorder (PSPD) are not uncommon. Still, the disease diagnosis relies primarily on structured interviews, with no objective indicators yet available to aid in the diagnosis. This has led to low diagnostic rates and overconsumption of health care resources for the disorder. Although there is a large body of research to improve the diagnosis of the condition, there are currently no objective indicators available for diagnosis. OBJECTIVES: The aim of this study is to investigate the clinical value of infrared thermography (IRT) for diagnosing PSPD. STUDY DESIGN: This is a retrospective study. SETTING: A single academic hospital, outpatient setting. METHODS: The clinical data of patients diagnosed with PSPD in the Pain Department of the First Affiliated Hospital of the Army Medical University from September 2020 to September 2022 were analyzed. The differences in IR thermograms between PSPD patients and healthy controls were analyzed, as well as the relationship between the Hamilton Depression Rating Scale, Hamilton Anxiety Scale, Pittsburgh Sleep Quality Index (PSQI) score, Patient Health Questionnaire-15, and Symptom Check List-90 and the differences in IR thermograms of PSPD patients. RESULTS: The mean squared error, structural similarity measure, different hash, contrast, entropy, inverse variance, and correlation values of the IR thermogram helped to determine PSPD with statistically significant differences (P < 0.05). Inverse variance values were weakly negatively correlated with PSQI scores of PSPD patients (r -0.4721, P < 0.05). LIMITATIONS: This study was limited by its sample size and retrospective observational design. CONCLUSIONS: IRT analysis is a useful objective method in diagnosis of PSPD, which also provides a new line of thought for studying the pathogenesis of PSPD. KEY WORDS: Persistent somatoform pain disorder, PSPD, thermal imaging, infrared thermography, IRT, image texture characteristics, psychometric variables, image analysis.