Comparative molecular dynamics simulations provided insights into the mechanisms of cold-adaption of alginate lyases from the PL7 family.

Alginate is an important polysaccharide that is abundant in the marine environments, including the Polar Regions, and bacterial alginate lyases play key roles in its degradation. Many reported alginate lyases show characteristics of cold-adapted enzymes, including relatively low temperature optimum of activities (Topt) and low thermal stabilities. However, the cold-adaption mechanisms of alginate lyases remain unclear. Here, we studied the cold-adaptation mechanisms of alginate lyases by comparing four members of the PL7 family from different environments: AlyC3 from the Arctic ocean (Psychromonas sp. C-3), AlyA1 from the temperate ocean (Zobellia galactanivorans), PA1167 from the human pathogen (Pseudomonas aeruginosa PAO1), and AlyQ from the tropic ocean (Persicobacter sp. CCB-QB2). Sequence comparison and comparative molecular dynamics (MD) simulations revealed two main strategies of cold adaptation. First, the Arctic AlyC3 and temperate AlyA1 increased the flexibility of the loops close to the catalytic center by introducing insertions at these loops. Second, the Arctic AlyC3 increased the electrostatic attractions with the negatively charged substrate by introducing a high portion of positively charged lysine at three of the insertions mentioned above. Furthermore, our study also revealed that the root mean square fluctuation (RMSF) increased greatly when the temperature was increased to Topt or higher, suggesting the RMSF increase temperature as a potential indicator of the cold adaptation level of the PL7 family. This study provided new insights into the cold-adaptation mechanisms of bacterial alginate lyases and the marine carbon cycling at low temperatures.

[Developments in Research on Salivary Biomarkers in the Diagnosis of Systemic Diseases].

Saliva, an important biological fluid secreted by oral glands, serves multiple functions. It performs cleaning and protective functions for oral tissues, safeguarding against biological, mechanical and chemical stimuli, while allowing for the sensory perception of taste and temperature. It is also responsible for the preliminary digestion of food. These functions and properties of saliva are attributed to the presence of electrolytes, buffers, proteins, glycoproteins, and lipids in saliva. Recent studies have found that saliva contains biomarkers that are closely connected with the pathophysiological status of the human body, suggesting that saliva makes an ideal biological fluid for drug monitoring and biomarker screening. Therefore, salivary biomarkers can be used as an instrument for physical monitoring and localization of the occurrence of diseases, thereby accomplishing early diagnosis of diseases and assessment of the overall health status of patients. However, the actual application of salivary biomarkers in the diagnosis and treatment of systemic diseases is still not widely available, and the establishment of evaluation criteria and the exploration of its mechanism are not sufficiently investigated. Herein, we reviewed the latest research findings on applying the salivary biomarkers in the diagnosis of systemic diseases.

[Latest Research Findings on Health Management Based on Saliva Testing].

Being one of the most important exocrine fluids of the human body, saliva can reflect the health status of the body. Soliva collection has various advantages--it is simple, painless, fast, and safe, and soliva can be collected multiple times a day. Therefore, it has been gradually applied in the exploration for biomarkers for disease detection, providing a basis for the monitoring of the course of diseases, medication monitoring, and efficacy evaluation. We should implement health management based on saliva testing, collect the medical data of the healthy and diseased individuals and monitor their whole life cycle health, perform clinical cohort study, aggregate the data on platforms for big data on health and medicine, manage and provide guidance for the health status of populations, pinpoint the high-risk factors for pathogenesis, and provide effective intervention, early warning, and assessment of the vital signs of individuals, thereby reinforcing health management of the whole life cycle and safeguarding people's health in an all-round way. In addition, it drives the development of the health industry and bears strategic significance for the promotion of national economic development. It is becoming a hot research topic promising great potential and impressive applicational prospects. Herein, we reviewed new techniques for clinical saliva testing and health management based on saliva testing.

The impact of obesity epidemic on type 2 diabetes in children and adolescents: A systematic review and meta-analysis.

AIM: To assess the impact of the obesity epidemic on type 2 diabetes (T2D), prediabetes and glycometabolic indices in children and adolescents. METHODS: We searched four electronic databases (PubMed, Embase, Cochrane and Web of Science). Cross-sectional or cohort studies that reported on obesity and the prevalence of T2D or prediabetes in children and adolescents were reviewed. The study design, sample size and clinical outcomes were extracted from each study. The prevalence of T2D and prediabetes from the studies were pooled using meta-analysis methods. RESULTS: Meta-analysis of 228184 participants showed that the prevalence of T2D was 1.3% (95% confidence interval (CI), 0.6-2.1%) in obese subjects, which was 13 times that in normal weight subjects (0.1%, 95% CI, 0.01-0.2%). The prevalence of prediabetes in obese subjects was 3 times that in normal subjects at 17.0% (13.0-22.0%) vs. 6.0% (0.01-11.0%). Moreover, BMI was positively correlated with the prevalence of T2D, prediabetes and glycometabolic indices in obese children and adolescents. CONCLUSION: The pooled results confirm that obesity in children and adolescents leads to statistically significant increases in the prevalence of T2D and prediabetes and in glycometabolic indicator levels.

Relationship between quality of life and adolescent glycolipid metabolism disorder: A cohort study.

BACKGROUND: The prevalence of glucolipid metabolic disorders (GLMDs) in children and adolescents has a recognized association with cardiovascular diseases and type 2 diabetes mellitus in adulthood. Therefore, it is important to enhance our under-standing of the risk factors for GLMD in childhood and adolescence. AIM: To explore the relationship between quality of life (QoL) and adolescent GLMD. METHODS: This study included 1956 samples in 2019 from a cohort study established in 2014. The QoL scale and glycolipid indexes were collected during follow-up; other covariates of perinatal factors, physical measures, and socioeconomic indicators were collected and adjusted. A generalized linear regression model and logistic regression model were used to analyse the correlation between QoL and GLMD. RESULTS: Higher scores of QoL activity opportunity, learning ability and attitude, attitude towards doing homework, and living convenience domains correlated negatively with insulin and homeostasis model assessment insulin resistance (IR) levels. Psychosocial factors, QoL satisfaction factors, and total QoL scores had significant protective effects on insulin and IR levels. Activity opportunity, learning ability and attitude, attitude towards doing homework domains of QoL, psychosocial factor, and total score of QoL correlated positively with high density lipoprotein. In addition, the attitude towards doing homework domain was a protective factor for dyslipidaemia, IR > 3, and increased fasting blood glucose; four factors, QoL and total QoL score correlated significantly negatively with IR > 3. In subgroup analyses of sex, more domains of QoL correlated with insulin and triglyceride levels, dyslipidaemia, and IR > 3 in females. Poor QoL was associated with an increased prevalence of GLMD, and the effect was more pronounced in males than in females. Measures to improve the QoL of adolescents are essential to reduce rates of GLMD. CONCLUSION: Our study revealed that QoL scores mainly correlate negatively with the prevalence of GLMD in adolescents of the healthy population. The independent relationship between QoL and GLMD can be illustrated by adjusting for multiple covariates that may be associated with glycaemic index. In addition, among females, more QoL domains are associated with glycaemic index.

Resistant mutants induced by adefovir dipivoxil in hepatitis B virus isolates.

AIM: To investigate the loci of adefovir dipivoxil (ADV)-induced resistance in hepatitis B virus (HBV) isolates and optimize the management of ADV-treated patients. METHODS: Between June 2008 and August 2010, a cross-sectional control study was conducted comprising 79 patients with chronic HBV infection-related liver disease who had been administered ADV monotherapy. Patients underwent liver imaging. Serum DNA extracts were analyzed for HBV DNA levels, genotypes, and serology markers, and deep sequencing of the HBV P gene was performed. RESULTS: ADV-resistant patients were found either with a single mutated locus, or with coexisting mutated loci. The most prevalent mutations were rtA181T, rtV214A, and rtN236T. Twenty-six patients had more than two mutated loci. The mutants were distributed among the patients without any significant affinity for gender, age, end-stage of liver disease, complications of non-alcoholic fatty liver disease, or HBV DNA levels. Patients with the rtA181T mutant were primarily infected with genotype C and e-antigen negative HBV, while patients with the rtN236T mutant were primarily infected by genotype B HBV (χ(2) = 6.004, 7.159; P = 0.023, 0.007). The duration of treatment with ADV was shorter in the single mutant group compared with the multi-mutant group (t = 2.426, P = 0.018). CONCLUSION: Drug-resistant HBV mutants are complex and diverse. Patients should receive the standard and first-line antiviral treatment, strictly comply with medication dosage, and avoid short-term withdrawal.

[Clinical analysis of hepatitis B virus mutations related to adefovir dipivoxil among patients with chronic hepatitis B virus infection in eastern Zhejiang province].

OBJECTIVE: To explore the clinical characteristics of hepatic B virus (HBV) mutations related to adefovir dipivoxil (ADV) among patients with chronic HBV infection in eastern Zhejiang province and provide some reference values on normative usage of antiviral drugs. METHODS: The data of chronic HBV-infected patients with HBV mutations related to ADV (n = 88) and non-mutation (n = 202) from June 2008 to August 2010 were analyzed retrospectively. The gene resistance mutations of HBV P region were analyzed by gene sequencing. And the HBV genotypes, HBV serum markers, HBV DNA levels and liver imaging findings were also analyzed. RESULTS: There were 9 cases with pre-existing mutations in 88 patients. The mutated sites were multiple and complicated. And the mutated sites related to other antiviral drugs were all accompanied by ADV-related mutations. The single mutated site was mostly at rtA181T (46.59%) and at rtV214A (11.36%). There were 27 cases (30.68%) with ≥ two mutated sites. The constituent ratios of males, end-stage liver diseases, complicated nonalcoholic fatty liver disease (NAFLD) and HBV genotype C infection in the mutation group were higher than those in the non-mutation group (P < 0.01, < 0.01, 0.019, 0.045). The average ages in the mutation group were also higher than those in the non-mutation group (P < 0.001). But the constituent ratios of HBeAg positivity and the levels of HBV DNA were lower (P = 0.002, 0.02). CONCLUSION: There may be some cases with pre-existing ADV-related mutations in ADV treatment-naive patients. The mutated sites occur at multiple loci, mostly at rtA181T and rtV214A. The male patients and those with a longer history of HBV infection, HBeAg negativity, HBV genotype C infection, illness progression and complicated NAFLD may be more susceptible to mutation. It is important for patients to accept and implement standardized regimens of antiviral drugs so as to prevent resistance and avoid salvage therapy.

Clinicopathologic features and molecular analysis of enterovirus 71 infection: report of an autopsy case from the epidemic of hand, foot and mouth disease in China.

A 15-month boy with fatal hand, foot, and mouth disease (HFMD) exhibited atypical symptoms and progressed rapidly to death. An autopsy was performed the next day and tissue sections were stained for histopathological examination. His intestinal samples were tested for enterovirus 71 (EV71), and the whole-genome sequence of EV71 was analyzed. An autopsy revealed that the central nervous system, lungs, and gut displayed severe meningitis and brainstem encephalitis, remarkable pulmonary congestion, edema, moderate inflammatory infiltration, and hemorrhage as well as intestinal mucosal congestion, epithelial necrosis, thinning intestinal wall, and submucosal lymphoid follicular hyperplasia. The heart showed myocardial interstitial congestion, myocardial edema, and some inflammatory infiltrates. There were no significant alterations in the architecture of other organs. EV71 antigen and apoptotic cells were detected in brain, lung and intestine by immunohistochemical staining and TUNEL (TdT-mediated dUTP nick-end labeling) respectively. Intestinal contents and intestinal autopsy samples of this case were positive for EV71, and the EV71 strain was classified as subgenogroup C4. In China, the severe forms of HFMD were mostly caused by EV71 subgenogroup C4 infection. Severe intestinal damages may relate to EV71 subgenogroup C4 infection. Thus, children with severe EV71 HFMD may have serious pathological changes in their central nervous system, lungs, and gut. Physicians should pay special attention to infants with atypical symptoms, particularly in EV71 epidemic areas for early diagnosis and treatment.