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.

Omics for deciphering oral microecology.

The human oral microbiome harbors one of the most diverse microbial communities in the human body, playing critical roles in oral and systemic health. Recent technological innovations are propelling the characterization and manipulation of oral microbiota. High-throughput sequencing enables comprehensive taxonomic and functional profiling of oral microbiomes. New long-read platforms improve genome assembly from complex samples. Single-cell genomics provides insights into uncultured taxa. Advanced imaging modalities including fluorescence, mass spectrometry, and Raman spectroscopy have enabled the visualization of the spatial organization and interactions of oral microbes with increasing resolution. Fluorescence techniques link phylogenetic identity with localization. Mass spectrometry imaging reveals metabolic niches and activities while Raman spectroscopy generates rapid biomolecular fingerprints for classification. Culturomics facilitates the isolation and cultivation of novel fastidious oral taxa using high-throughput approaches. Ongoing integration of these technologies holds the promise of transforming our understanding of oral microbiome assembly, gene expression, metabolites, microenvironments, virulence mechanisms, and microbe-host interfaces in the context of health and disease. However, significant knowledge gaps persist regarding community origins, developmental trajectories, homeostasis versus dysbiosis triggers, functional biomarkers, and strategies to deliberately reshape the oral microbiome for therapeutic benefit. The convergence of sequencing, imaging, cultureomics, synthetic systems, and biomimetic models will provide unprecedented insights into the oral microbiome and offer opportunities to predict, prevent, diagnose, and treat associated oral diseases.

Artemisinins inhibit oral candidiasis caused by Candida albicans through the repression on its hyphal development.

Candida albicans is the most abundant fungal species in oral cavity. As a smart opportunistic pathogen, it increases the virulence by switching its forms from yeasts to hyphae and becomes the major pathogenic agent for oral candidiasis. However, the overuse of current clinical antifungals and lack of new types of drugs highlight the challenges in the antifungal treatments because of the drug resistance and side effects. Anti-virulence strategy is proved as a practical way to develop new types of anti-infective drugs. Here, seven artemisinins, including artemisinin, dihydroartemisinin, artemisinic acid, dihydroartemisinic acid, artesunate, artemether and arteether, were employed to target at the hyphal development, the most important virulence factor of C. albicans. Artemisinins failed to affect the growth, but significantly inhibited the hyphal development of C. albicans, including the clinical azole resistant isolates, and reduced their damage to oral epithelial cells, while arteether showed the strongest activities. The transcriptome suggested that arteether could affect the energy metabolism of C. albicans. Seven artemisinins were then proved to significantly inhibit the productions of ATP and cAMP, while reduced the hyphal inhibition on RAS1 overexpression strain indicating that artemisinins regulated the Ras1-cAMP-Efg1 pathway to inhibit the hyphal development. Importantly, arteether significantly inhibited the fungal burden and infections with no systemic toxicity in the murine oropharyngeal candidiasis models in vivo caused by both fluconazole sensitive and resistant strains. Our results for the first time indicated that artemisinins can be potential antifungal compounds against C. albicans infections by targeting at its hyphal development.

GmPLP1 negatively regulates soybean resistance to high light stress by modulating photosynthetic capacity and reactive oxygen species accumulation in a blue light-dependent manner.

High light stress is an important factor limiting crop yield. Light receptors play an important role in the response to high light stress, but their mechanisms are still poorly understood. Here, we found that the abundance of GmPLP1, a positive blue light receptor protein, was significantly inhibited by high light stress and mainly responded to high blue light. GmPLP1 RNA-interference soybean lines exhibited higher light energy utilization ability and less light damage and reactive oxygen species (ROS) accumulation in leaves under high light stress, while the phenotype of GmPLP1:GmPLP1-Flag overexpression soybean showed the opposite characteristics. Then, we identified a protein-protein interaction between GmPLP1 and GmVTC2, and the intensity of this interaction was primarily affected by sensing the intensity of blue light. More importantly, overexpression of GmVTC2b improved soybean tolerance to high light stress by enhancing the ROS scavenging capability through increasing the biosynthesis of ascorbic acid. This regulation was significantly enhanced after interfering with a GmPLP1-interference fragment in GmVTC2b-ox soybean leaves, but was weakened when GmPLP1 was transiently overexpressed. These findings demonstrate that GmPLP1 regulates the photosynthetic capacity and ROS accumulation of soybean to adapt to changes in light intensity by sensing blue light. In summary, this study discovered a new mechanism through which GmPLP1 participates in high light stress in soybean, which has great significance for improving soybean yield and the adaptability of soybean to high light.

The associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents: a prospective cohort study.

Uncontrolled pediatric hypertension may increase the risk of hypertension in adulthood. Several studies have reported an association between hematological parameters and blood pressure (BP) levels. However, epidemiologic evidence of this association in children and adolescents remains scarce. This study aims to explore the associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents. This longitudinal study was conducted with 1368 participants aged 6-8 years from baseline visit to follow-up visit. Compared with participants from the normal blood pressure (BP) group, participants from the elevated BP group had significantly higher baseline red blood cell (RBC) counts, hemoglobin (Hb) counts and hematocrit (Hct) levels (all P < 0.001). A multilevel linear mixed model was conducted to analyze the relationship between hematological parameters and BP levels. The results suggested that SBP, DBP and MAP increased significantly with a quartile increase of levels of hematological parameters (all P < 0.05). Furthermore, a multilevel mixed logistic regression model was used to analyze the risk of per interquartile range increase in hematological parameters on the incidence of prehypertension and hypertension. The risk of prehypertension and hypertension incidence increased by (1.34 (95%CIs: 1.20, 1.50)), (1.38 (95%CIs: 1.24,1.54)), (1.33 (95%CIs: 1.19,1.50)), (1.14 (95%CIs: 1.03,1.26)) fold with a one-quartile increase in levels of RBC, Hb, Hct and Fe, respectively (all P < 0.05). This longitudinal study showed that hematological parameters were positively associated with BP levels in healthy children and adolescents, which excluded the effect of antihypertensive drugs on BP levels that often appeared in adults.

[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.

The relationship of remnant cholesterol and abdominal obesity in children: A cross-sectional study.

Background: Previous studies found that remnant cholesterol (RC) is a risk factor for cardiovascular diseases and childhood obesity is associated with cardiometabolic diseases. This study aimed to explore the relationship between RC and abdominal obesity in children. Methods: A total of 5,959 children, aged 6-12 years old, were selected from a cross-sectional study in urban-rural areas of Chongqing, China. RC was calculated by total cholesterol (TC)-high-density lipoprotein (HDL-C) cholesterol-low-density lipoprotein (LDL-C) cholesterol and was divided into four groups by quartiles (Q1-Q4). Results: Compared to children with the lowest RC (Q1), children with higher RC had significantly higher odds of abdominal obesity (Q2: OR = 1.450, 95% CI: 1.131-1.859, p < 0.05; Q3: OR = 2.127, 95% CI: 1.632-2.772, p < 0.001; Q4: OR = 2.386, 95% CI: 1.819-3.130, p < 0.001). In the stratified analyses by urban-rural areas, the odds ratios were greater in rural areas (Q2: OR = 2.228, 95% CI: 1.572-3.160, p < 0.001; Q3: OR = 3.668, 95% CI: 2.191-6.140, p < 0.001; Q4: OR = 6.490, 95% CI: 2.271-18.551, p < 0.001) than in urban areas (Q2: OR = 1.644, 95% CI: 1.192-2.266, p < 0.05; Q3: OR = 2.266, 95% CI: 1.667-3.082, p < 0.001; Q4: OR = 2.711, 95% CI: 2.005-3.665, p < 0.001). Conclusions: Our study found that RC was positively correlated with abdominal obesity in children, and this association was higher for children living in rural areas.

Associations of self-reported residential noise exposure with obesity and hypertension in children and adolescents.

Background: Epidemiologic evidence linking environmental noise to obesity and hypertension remains scarce, especially in children, and the results remain inconclusive. This study aims to examine the cross-sectional associations of self-reported residential noise exposure with obesity and hypertension in children and adolescents. Methods: As an ongoing study, a representative sample of the children aged 6-9 years in Chongqing were selected in 2014. In 2019, self-reported residential noise (answer categories: "very quiet," "moderately quiet," "slightly quiet," and "not at all quiet") data were collected, and 3,412 participants with completed data were included in the analyses. Results: Participants living in a quieter area had a significantly lower risk of obesity than those living in a noisy area (very quiet: OR = 0.50, 95%CI: 0.29-0.88, P = 0.015; moderately quiet: OR = 0.61, 95%CI: 0.36-1.02, P = 0.059). Similar associations were observed for abdominal obesity, although did not reach statistical significance. Consistently, residential noise exposure was significantly associated with body mass index (BMI) and waist-to-height ratio. Self-reported residential noise exposure was positively associated with systolic blood pressure (ß = -1.808; 95%CI = -3.495, -0.110; P = 0.037). When sleep quality, study stress, BMI, and vegetable/fruits consumption were further adjusted, all effect estimates decreased, and no statistical association was observed between noise exposure and blood pressure. Furthermore, we found that the mediating effects of obesity on the associations of self-reported residential noise exposure with hypertension were 6.8% (% of total effect mediated = 0.068, 95%CI: -2.58, 3.99), although did not reach statistical significance. Conclusions: Self-reported residential noise exposure was associated with a higher risk of obesity or abdominal obesity. Also, self-reported residential noise exposure was positively associated with hypertension, and obesity may partially mediate this association, but did not reach statistical significance.

Effect of using diode laser on Enterococcus faecalis and its lipoteichoic acid (LTA) in chronic apical periodontitis.

The purpose of this study was to evaluate the effect of diode laser irradiation on Enterococcus faecalis (E. faecalis) and its lipoteichoic acid (LTA). Ninety-six freshly extracted single-rooted teeth were divided into six groups, n = 8 per group. Groups 1, 2, 3, and 4 as laser group (810 nm PILOT™ Diode Laser, 400 µm fiber diameter, continuous mode, 30 s time) with powers at 1.0 W, 1.5 W, 2.0 W, and 2.5 W respectively. Group 5 or positive control group (3 ml of 1% sodium hypochlorite (NaOCl) irrigation) and group 6 or negative control group (3 ml of normal saline (0.9% NaCl) irrigation). Root canal samples were collected before and after receiving laser irradiation and irrigation solution. Cultivable bacteria were determined by counting the colony (CFU/ml). Evaluation of temperature on the external root surface of teeth was done with K type thermocouple using laser at different powers. Enzyme-linked immunosorbant assay (ELISA) was performed to measure the LTA levels and the correlations between E. faecalis count, LTA levels, and rise in temperature were observed using Pearson's correlation test. E. faecalis LTA was subjected to laser irradiation and its structural damage was examined by thin layer chromatography (TLC). Compared with the control groups, all laser groups showed a decreased colony counts and decreased LTA levels with statistically significant difference (p Ë‚ 0.05). The bactericidal effect and LTA reduction of laser was better at 2.5 W power. Laser at 2.5 W power had temperature rise of more than 7 °C which is beyond the safe thermal threshold level. No statistically significant correlation was found between E. faecalis count, levels of LTA, and rise in external root surface temperature (p Ëƒ 0.05). TLC results showed a structural damage in the glycolipid moiety of E. faecalis LTA. Diode laser can effectively reduce the E. faecalis count and its LTA levels.

Active-target-based calibration of relative poses of mirrors in intraoral scanners.

This paper describes a practical method using an active target to calibrate relative poses of mirrors in intraoral scanners. Intraoral scanning is a fast-growing technology. Mirrors are widely used in intraoral scanners to increase the measuring area of a single view. The relative poses of these mirrors must be calibrated for accurate three-dimensional profiling. We present and analyze the geometric model of multiview mirrors. A calibration method for relative poses of mirrors is developed based on fringe projection. Vertical and horizontal fringes are displayed on an active target, and every pixel can be viewed as a calibration marker. This calibration method allows the mirrors to have a narrow common field of view. A cell phone display is chosen as the active target, and experimental results demonstrate the effectiveness of the proposed method compared to traditional methods.

A quantitative study of 3D-scanning frequency and Δd of tracking points on the tooth surface.

Micro-movement of human jaws in the resting state might influence the accuracy of direct three-dimensional (3D) measurement. Providing a reference for sampling frequency settings of intraoral scanning systems to overcome this influence is important. In this study, we measured micro-movement, or change in distance (∆d), as the change in position of a single tracking point from one sampling time point to another in five human subjects. ∆d of tracking points on incisors at 7 sampling frequencies was judged against the clinical accuracy requirement to select proper sampling frequency settings. The curve equation was then fit quantitatively between ∆d median and the sampling frequency to predict the trend of ∆d with increasing f. The difference of ∆d among the subjects and the difference between upper and lower incisor feature points of the same subject were analyzed by a non-parametric test (α = 0.05). Significant differences of incisor feature points were noted among different subjects and between upper and lower jaws of the same subject (P < 0.01). Overall, ∆d decreased with increasing frequency. When the frequency was 60 Hz, ∆d nearly reached the clinical accuracy requirement. Frequencies higher than 60 Hz did not significantly decrease Δd further.

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.

[Effect of siRNA-mediated silencing of Notch2 on proliferation of the HepG2 human hepatocellular carcinoma cells].

OBJECTIVE: To explore the effect of silencing the Notch2 gene by small interfering (si)RNA on the proliferation of the HepG2 human hepatocellular carcinoma (HCC) cells. METHODS: Notch2-siRNA was transfected as a liposomal formulation into HepG2 cells. The non-HCC cell lines SG07901 (gastric cancer) and SW620 (colon cancer) were used as controls. The mRNA expression of Notch2 and Hesl were detected by RTPCR, and the protein expression of Notch2 was detected by western blotting. The proliferation of transfected HepG2 cells was assessed by the cell counting kit-8 (CCK8) colorimetric assay. RESULTS: The untransfected HepG2 cells showed significantly upregulated transcript expression of Notch2, and not of Notch1, Notch3 or Notch4, compared to the other non-HCC cell lines. Following transfection of Noteh2-siRNA into HepG2 cells, the mRNA expression of Notch2 and Hes1 and the protein expression of Notch2 were significantly decreased. The rales of proliferation inhibition in HepG2 following transfection of Notch2-siRNA showed an increasing time-related trend, with 2.64% ± 1620% at 12 h, 38.34% ± 8.80% at 24 h, 70.05% ± 7.80% at 48 h, 70.78% ± 10.00% at 72 h, and 74.22% ± 4.80% at 96 h.The inhibition rate at 24 h of transfection was significantly different from that of the groups of control cells. CONCLUSION: Notch2 is upregulated in the common HCC cultured cell line HepG2. siRNA-mediated silencing of Notch2 exerts inhibition effects on HepG2 proliferation, suggesting the potential for this approach as targeted therapy for treating HCC.

[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.