Mapping enzyme activity in living systems by real-time mid-infrared photothermal imaging of nitrile chameleons.

Simultaneous spatial mapping of the activity of multiple enzymes in a living system can elucidate their functions in health and disease. However, methods based on monitoring fluorescent substrates are limited. Here, we report the development of nitrile (C≡N)-tagged enzyme activity reporters, named nitrile chameleons, for the peak shift between substrate and product. To image these reporters in real time, we developed a laser-scanning mid-infrared photothermal imaging system capable of imaging the enzymatic substrates and products at a resolution of 300 nm. We show that when combined, these tools can map the activity distribution of different enzymes and measure their relative catalytic efficiency in living systems such as cancer cells, Caenorhabditis elegans, and brain tissues, and can be used to directly visualize caspase-phosphatase interactions during apoptosis. Our method is generally applicable to a broad category of enzymes and will enable new analyses of enzymes in their native context.

Millimeter-deep micron-resolution vibrational imaging by shortwave infrared photothermal microscopy.

Deep-tissue chemical imaging plays a vital role in biological and medical applications. Here, we present a shortwave infrared photothermal (SWIP) microscope for millimeter-deep vibrational imaging with sub-micron lateral resolution and nanoparticle detection sensitivity. By pumping the overtone transition of carbon-hydrogen bonds and probing the subsequent photothermal lens with shortwave infrared light, SWIP can obtain chemical contrast from polymer particles located millimeter-deep in a highly scattering phantom. By fast digitization of the optically probed signal, the amplitude of the photothermal signal is shown to be 63 times larger than that of the photoacoustic signal, thus enabling highly sensitive detection of nanoscale objects. SWIP can resolve the intracellular lipids across an intact tumor spheroid and the layered structure in millimeter-thick liver, skin, brain, and breast tissues. Together, SWIP microscopy fills a gap in vibrational imaging with sub-cellular resolution and millimeter-level penetration, which heralds broad potential for life science and clinical applications.

Mapping Enzyme Activity in Living Systems by Real-Time Mid-Infrared Photothermal Imaging of Nitrile Chameleons.

Enzymes are vital components in a variety of physiological and biochemical processes. Participation of various enzyme species are required for many biological events and signaling networks. Thus, spatially mapping the activity of multiple enzymes in a living system is significant for elucidating enzymatic functions in health and connections to diseases. Here, we report the development of nitrile (C≡N)-tagged enzyme activity reporters, named nitrile chameleons for the shifted peak between substrate and product. By real-time mid-infrared photothermal imaging of the enzymatic substrates and products at 300 nm resolution, our approach can map the activity distribution of different enzymes and quantitate the relative catalytic efficiency in living cancer cells, C. elegans, and brain tissues. An important finding is the direct visualization of caspase-phosphatase cooperation during apoptosis. Our method is generally applicable to a broad category of enzymes and will advance the discovery of potential targets for diagnosis and drug development.

Prevalence and Differences of Depression, Anxiety, and Substance Use Between Chinese College-Age Students Studying in China and America During the Coronavirus Disease 2019 Pandemic.

Introduction: The coronavirus disease (COVID-19) swept the globe and harmfully influenced the mental health and behaviors of the college student population. This study aims to examine the prevalence and difference of mental health and the substance use problems of the Chinese college-age students studying in China and America (CSA) during the COVID-19 pandemic. Methods: One thousand five hundred four students participated in this study. A total of 42.12% of students are enrolled in Chinese colleges, and 57.78% of students are enrolled in American colleges, aged 17-23 years ( x ¯ ± s = 19.90 ± 1.50). Binary logistic regression and independent t-test were used in this study to find the predictor variables and association among mental health, substance use problems, and student population. Results: The two student groups had a statistical difference in General Anxiety Disorder-7 scale, alcohol, medicines, drinks, drugs and cigarettes (p < 0.01). The students suffering depression problems from the two groups have statistical significance with drinks (odds ratio = 0.89, 95% confidence interval = 0.81-0.97, p < 0.05; odds ratio = 1.11, 95% confidence interval = 1.04-1.19, p < 0.01). CSA experiencing anxiety problem had a significant association with alcohol, drinks, cigarette, and desserts (p < 0.05). Conclusion: This is the first cross-sectional study focusing on the comparison of the Chinese college-age students' mental health and substance use problems who are studying in China and America during the pandemic. Our study revealed severe mental health and substance use problems in both student groups, particularly in the CSA during the COVID-19 pandemic. The findings of our study also highlight the evidence to find more interventions and preventions to solve the different mental health and substance use problems for college students.

Effects of Lung Protective Ventilation on the Cognitive Function Level of Patients with Esophageal Cancer.

BACKGROUND: We intended to investigate the effects of lung protective ventilation on the cognitive function level of patients with esophageal cancer. METHODS: Overall, 132 patients with esophageal cancer admitted to Taian Central Hospital, Taian China from January 2013 to January 2017 were enrolled in the study. According to the random number table method, they were divided into observation group and control group, 66 cases each. All patients underwent general anesthesia for thoracoscopic esophageal cancer radical operation, and lung protective ventilation and conventional positive pressure ventilation were used respectively. The levels of SOD, NSE and MDA, MMSE score and WMS memory quotient in the blood of the elbow vein were compared between the two groups at different times. RESULTS: The levels of SOD and MMSE in the observation group at T2 and T3 were higher than those in the control group, and the NSE and MDA levels were lower than those in the control group (P=0.013, 0.033, 0.015, 0.044, 0.034, 0.029, 0.014, 0.017). The incidence of postoperative cognitive impairment was lower in the observation group than in the control group (P=0.007). The WMS memory quotient scores of the patients in the T2, T3, and T4 observation groups were higher than those in the control group (p=0.009, 0.032, 0.040). CONCLUSION: Lung protective ventilation can reduce the oxidative stress injury for patients and improve their postoperative cognitive function and memory ability.

The analyses of relationships among nucleotide, synonymous codon and amino acid usages for E2 gene of bovine viral diarrhea virus.

In this study, the systemic analyses of nucleotide, codon and amino acid usages for E2 gene of bovine viral diarrhea virus (BVDV) were carried out for estimating its genetic features. The nucleotide usage pattern at the first codon position was strongly influenced by the overall nucleotide composition, while the nucleotide usage patterns at the second and third codon positions seemed to have little link to the overall nucleotide composition. The result indicated that the mutation pressure from nucleotide composition constraint was not the single evolutionary force for genetic features of BVDV E2 gene. Just 18 out of 59 synonymous codons were similar with synonymous codon usage patterns for E2 gene between BVDV1 and BVDV2, while all synonymous codons which contain CpG dinucleotides were selected at the low level by E2 gene, suggesting that this gene suppressed the usages of codons containing CpG dinucleotides to regulate E2 gene replicate and transcript efficiently and avoid immune response from infected hosts. Amino acid usage patterns of E2 protein were generally different between BVDV1 and BVDV2. The patterns of synonymous codon and amino acid usages for E2 gene might be caused by the equilibrium of evolutionary forces from virus and host. Our work gave new investigations into the role of host origin in the formations of synonymous codon/amino acid usages and the evolutionary trend of BVDV E2 gene. The genetic characteristics that codon/amino acid usages of E2 gene adapted to the internal environment of individual animals might assist in understanding the changes of genetics and antigenicity for newly emerging BVDV.

Effects of propofol pretreatment on lung morphology and heme oxygenase-1 expression in oleic acid-induced acute lung injury in rats

Abstract Purpose: To investigate the effects of propofol pretreatment on lung morphology and heme oxygenase-1 expression in oleic acid -induced acute lung injury in rats. Methods: A total of 32 male Sprague-Dawley rats (250-300g) were randomly divided into the following four groups (n=8/group): group C, group OA, group OA+PR, and group OA+IX to compare related parameter changes. Results: PaO2, PCO2, and PaO2/FiO2 were significantly different among the four treatment groups (P<0.05 or P<0.01). Lung wet/dry weight ratio and HO-1 protein expression also significantly differed among the groups (P<0.01). Immunohistochemistry showed that the expression of HO-1 in group OA+PR was stronger than those in groups OA, OA+IX, and C. Light microscopy revealed that pathological changes in lung tissues in group OA+PR were milder than those in group OA and group OA+IX. Electron microscopy showed that alveolar type II epithelial cell ultrastructure in group OA was relatively irregular with cell degeneration and disintegration and cytoplasmic lamellar bodies were vacuolized. Changes in group OA+PR were milder than those in group OA; however, they were more severe in group OA+IX than in group OA. Conclusion: Propofol significantly increases the expression of HO-1 in the lung tissueand prevents changes in lung morphology due to ALI in rats.

In situ detection of TGF betas, TGF beta receptor II mRNA and telomerase activity in rat cholangiocarcinogenesis.

AIM: Initial report on the in situ examination of the mRNA expression of transforming growth factor betas (TGFbetas), TGFbeta type II receptor (TbetaRII) and telomerase activity in the experimental rat liver tissue during cholangiocarcinogenesis. METHODS: Rat liver cholangiocarcinogenesis was induced by 3'-methyl 4-dimethylazobenzene (3'Me-DAB). In situ hybridization was used to examine the TGFbetas) and TGFbeta type II receptor (TbetaRII) mRNA, in situ TRAP was used to check the telomerase activity in the tissue samples. RESULTS: There was no TGFbetas, TbetaRII mRNA expression or telomerase activity in the control rat cholangiocytes. The expression of TGFbeta1, TbetaRII was increased in regenerative, hyperplastic, dysplastic cholangiocytes and cholangiocarcinoma (CC) cells. The expression of TGFbeta2 mRNA was observed in only a part of hyperplastic, dysplastic cholangiocytes. TGFbeta3 expression was very weak, only in hyperplastic lesion. There was positive telomerase activity in the regenerative, hyperplastic, dysplastic cholangiocytes, and CC cells. Stroma fibroblasts of these lesions also showed positive TGFbetas, TbetaRII mRNA expression and telomerase activity. CONCLUSION: There were TGFbetas, TbetaRII expression and telomerase activity in hyperplastic, dysplastic cholangiocytes, cholangiocarcinoma cells as well as in stroma fibroblasts during cholangiocarcinogenesis. Their expression or activity is important in cholangiocarcinogenesis andstroma formation.