Comprehensive evaluation of serum hepatic proteins in predicting prognosis among cancer patients with cachexia: an observational cohort study.

BACKGROUND: Hepatic proteins, including albumin, prealbumin, and transferrin have been confirmed to be prognostic predictors in various cancers. This study aimed to comprehensively assess the prognostic value of these three serum markers in patients with cancer cachexia. METHODS: This multicenter prospective cohort study included 1303 cancer cachexia patients, among whom 592 deaths occurred during a median follow-up of 20.23 months. The definition of cachexia was based on the 2011 international consensus. Concordance index (C-index) and receiver operating characteristic (ROC) curves were applied to compare the prognostic performance. The primary outcome was overall survival, which was calculated using the Kaplan-Meier method generated by log-rank test. A Cox proportional hazard regression model was used to identify independent predictors associated with survival. The secondary outcomes included 90-days mortality and quality of life (QoL). RESULTS: C-index and ROC curves showed that albumin had the most accurate predictive capacity for survival, followed by transferrin and prealbumin. Multivariate Cox analysis confirmed that low albumin (hazard ratio [HR] = 1.51, 95% confidence interval [95%CI] = 1.28-1.80, P < 0.001), prealbumin (HR = 1.42, 95%CI = 1.19-1.69, P < 0.001), and transferrin (HR = 1.50, 95%CI = 1.25-1.80, P < 0.001) were independent risk factors for long-term survival in cancer patients with cachexia. In subgroup analysis, the prognostic value of low albumin was significant in patients with upper gastrointestinal, hepatobiliary and pancreatic, and colorectal cancers; low prealbumin was significant in colorectal cancer; and low transferrin was significant in patients with upper gastrointestinal and colorectal cancer. All three hepatic proteins were valuable as prognostic predictors for patients with advanced (Stage III and IV) cancer with cachexia. The risks of 90-days mortality and impaired QoL were higher in cachexia patients with low albumin, prealbumin, and transferrin levels. CONCLUSION: Low albumin, prealbumin, and transferrin levels were all independent prognostic factors affecting patients with cancer cachexia, especially in patients in the advanced stages. These results highlight the value of routinely checking serum hepatic proteins in clinical practice to predict the prognosis of patients with cancer cachexia.

Association Between Sarcopenia, Clinical Outcomes, and Survival in Patients with Extensive-Stage Small Cell Lung Cancer Treated with First-Line Immunochemotherapy: A Prospective Cohort Study.

OBJECTIVE: To investigate the association between sarcopenia, short-term efficacy, and long-term survival in patients with extensive small-cell lung cancer (SCLC) treated with standard first-line immunochemotherapy. METHODS: A total of 63 patients initially diagnosed with extensive-stage small cell lung cancer were enrolled in the prospective study from December 1, 2020 to December 31, 2022. The clinical characteristics, body composition, blood test results, and image data were obtained before treatment. Patients were divided into sarcopenia and non-sarcopenia groups according to the diagnostic criteria of the Asian Sarcopenia Working Group 2019. The primary outcome was overall survival (OS) and comprehensive survival analyses were performed. Secondary outcomes included short-term efficacy and adverse events associated with first-line immunochemotherapy. RESULTS: The median age of the 63 patients enrolled in our study was 63.0 years (40-80 years). The incidence of sarcopenia was 19.0% (12/63) in patients with extensive SCLC. Compared with non-sarcopenia patients, extensive-stage SCLC patients with sarcopenia were significantly older (69.0 vs. 62.0, P = 0.017), and had lower body mass index (BMI) (20.29 vs. 24.27, P < 0.001), hand grip strength (HGS) (20.42 vs. 30.75, P < 0.001), and albumin (35.9 vs. 41.40, P < 0.001). The objective response rate after two cycles of standard first-line immunochemotherapy in the sarcopenia group was lower than in the non-sarcopenia group (30.0 vs. 78.9%, P = 0.012). There was no significant difference in chemotherapy-related hematological toxicity between the two groups. During a median follow-up of 15 months (3-33 months), patients with extensive SCLC had a median OS of 24 months, with 1-year survival of 75% and 2-year survival of 52%, respectively. Compared to non-sarcopenia patients, the median OS in the sarcopenia group was significantly shorter (9 vs. 24 months, P = 0.0014). Multivariate Cox analysis showed that sarcopenia was an independent risk factor for OS in patients with extensive SCLC (HR = 4.993, 95%CI = 1.106-22.538, P = 0.037). CONCLUSIONS: Patients with Extensive SCLC and sarcopenia had worse clinical outcomes and shorter OS. Sarcopenia is a prognostic factor affecting first-line treatment efficacy and long-term survival of patients with SCLC in the era of immunotherapy.

Geriatric Nutritional Risk Index Combined with Calf Circumference Can be a Good Predictor of Prognosis in Patients Undergoing Surgery for Gastric or Colorectal Cancer.

OBJECTIVES: To explore the effect of combined hematological and physical measurement indicators on the prognosis of patients undergoing surgery for gastric or colorectal cancer and to screen for the best prognostic indicators. INTRODUCTION: Gastric and colorectal cancer is a widespread health concern worldwide and one of the major contributors to cancer-related death. The hematological and physical measurement indicators have been shown to associate with the prognosis of patients undergoing surgery for gastric or colorectal cancer, respectively, but it is still unclear whether the combination of the two can reflect the prognosis more effectively. METHODS: Thirteen hematological indicators and 5 physical measurement indicators were selected in this study, and the most promising ones were screened using LASSO regression. Then, the best prognostic indicators were selected by time-ROC curves. Survival curves were constructed using the Kaplan-Meier method, and the effects of hematological and physical measurement indicators on the prognosis of patients undergoing surgery for gastric or colorectal cancers were evaluated by Cox proportional risk regression analysis. In addition, the relationship between hematological and physical measurement indicators on secondary outcomes, including length of stay, hospitalization costs, intensive care unit (ICU) admission, and patients' subjective global assessment scores (PGSGA), was explored. RESULTS: After initial screening, among the hematological indicators, the geriatric nutritional risk index (GNRI) showed the highest mean area under the curve (AUC) values. Among body measures, calf circumference (CC) showed the highest mean AUC value. Further analyses showed that the combination of combined nutritional prognostic index (GNRI) and calf circumference (CC) (GNRI-CC) had the best performance in predicting the prognosis of patients undergoing surgery for gastric or colorectal cancers. Low GNRI, low CC, and low GNRI-low CC increased the risk of death by 44%, 48%, and 104%, respectively. Sensitivity analyses showed the same trend. In addition, low GNRI-low CC increased the risk of malnutrition by 17%. CONCLUSION: This study emphasizes that a combination of blood measures and body measures is essential to accurately assess the prognosis of patients undergoing surgery for gastric or colorectal cancers. The GNRI-CC is a good prognostic indicator and can also assess the risk of possible malnutrition.

Pressure-Modulated Interface Engineering toward Realizing Core@Shell Configuration Transition.

The strained interface of core@shell nanocrystals (NCs) can effectively modulate the energy level alignment, thereby significantly affecting the optical properties. Herein, the unique photoluminescence (PL) response of doped Mn ions is introduced as a robust probe to detect the targeted pressure-strain relation of CdS@ZnS NCs. Results show that the core experiences actually less pressure than the applied external pressure, attributed to the pressure-induced optimized interface that reduces the compressive strain on core. The pressure difference between core and shell increases the conduction band and valence band offsets and further achieves the core@shell configuration transition from quasi type II to type I. Accordingly, the PL intensity of CdS@ZnS NCs slightly increases, along with a faster blue-shift rate of PL peak under low pressure. This study elucidates the interplay between external physical pressure and interfacial chemical stress for core@shell NCs, leading to precise construction of interface engineering for practical applications.

A comprehensive analysis of the association between anemia and systemic inflammation in older patients with cancer.

PURPOSE: Our study aimed to comprehensively analyze the association between anemia and systemic inflammation in older patients with cancer. METHODS: This multicenter prospective cohort study included 4955 older patients with cancer between 2013 and 2020. Logistic regression analysis was performed to investigate risk factors of anemia, reporting odds ratios (ORs), and 95% confidence intervals (CIs). Comprehensive survival analyses, including Kaplan-Meier curve, Cox proportional risk model, and subgroup analysis, were performed. RESULTS: The participants' median age was 70.0 (interquartile range [IQR]=67.0-74.0) years, with 3293 (66.5%) males and 1662 (33.5%) females. There were 1717 (34.7%) older patients with cancer diagnosed with anemia. High neutrophil-to-lymphocyte ratio (NLR) was an independent risk factor associated with anemia (adjusted OR=1.97, 95%CI=1.73-2.24, P<0.001). In older patients with cancer and different anemia levels, the median overall survival was significantly shorter in those with a high NLR. In multivariate Cox analysis, high NLR served as a negative factor, independently affecting survival. The anemia-inflammation prognostic grading system showed a significant survival discriminative performance in older patients with cancer. After adjusting for confounders, high grades were independent risk factors for survival (grade 2: hazard ratio [HR] = 1.38, 95%CI = 1.26-1.52, P<0.001; grade 3: HR=1.82 95%CI = 1.59-2.09, P<0.001). This grading system was beneficial in determining survival in patients with lung, digestive tract, and urogenital cancers. CONCLUSIONS: Increased systemic inflammation is an independent risk factor for anemia. A high inflammatory status is also associated with poor survival in older cancer patients at different anemia levels. The anemia-inflammation grading system is beneficial for determining the prognosis in older patients with cancer.

Prognostic importance of systemic inflammation and insulin resistance in patients with cancer: a prospective multicenter study.

BACKGROUND: Systemic inflammation and insulin resistance (IR) are often associated with poor prognosis in cancer. This study aimed to investigate the prognostic value of surrogate systemic inflammation and IR indices in patients with cancer. METHODS: This multicenter prospective study included 5,221 patients with cancer, with a mean age of 59.41±11.15 years, of whom 3,061 (58.6%) were male. The surrogate IR indices included low-density lipoprotein cholesterol to high-density lipoprotein cholesterol (LHR) ratio, total cholesterol to high-density lipoprotein cholesterol (TC/ HDL-c) ratio, triglyceride to high-density lipoprotein cholesterol (TG/HDL-c) ratio, and fasting triglyceride glucose (TyG). Prognostic receiver operator characteristic (ROC) curves and C-indices were used to select a better surrogate IR index in patients with cancer. The prognostic value of the indicators was evaluated using univariate and multivariate survival analyses. RESULTS: In this study, the median survival time of patients was 44.5 (40.5-51.4) months, and the overall mortality in the 12-month period was 1,115 (53.7%), with 196 mortality events per 1,000 patient-years of patients' follow-up. The prognostic ROC curve and C-index suggested that the prognostic value of LHR was better than that of the other IR indices. The multivariate-adjusted hazard ratios (HRs) for overall survival (OS) were higher in patients with high C-reactive protein (CRP) (HR, 1.51; 95% confidence interval [CI]: 1.38-1.65) and high LHR (HR, 1.20; 95% CI: 1.06-1.37), respectively. The mortality rate of patients with both high CRP and LHR was 1.75-fold higher than that of patients with both low CRP and LHR. CONCLUSION: Both CRP and LHR showed good survival predictions in patients with cancer. CRP combined with LHR can improve the predictive power of patients with cancer.

Design, 3D printing, and evaluation of full-contact dental models for denture tests.

AIM: The full-contact model has been widely used in tooth preparation and prosthesis fabrication. However, it is rarely used in denture tests. The purpose of the present study was to design a suitable full-contact dental model for denture tests. MATERIALS AND METHODS: A standard dental model with the complete tooth morphology was raster scanned and 3D reconstructed. Then, the positioning and fixing surfaces of the dental model were reshaped. The dental model was digitally trimmed into two parts: a fundamental part and a replaceable part. The modular design was presented according to dentition defects around the first molar. The prepared tooth replicas were designed through preparation/scanning/registration/separation sequences. The dental model was fabricated by stereolithography (SLA) 3D-printing rapid prototype technology. The static fracture force of the dental model was predicted using the finite element method. The effects of the four design methods on the suitability of the five testing operations (abutment fabrication, prosthesis fabrication, assembling, loading, and observation) were quantitatively analyzed. The static tests of three fixed partial dentures (FPDs), including tooth-supported, implant-supported, and tooth-tooth-supported prostheses, were conducted to investigate the fracture feature. The dynamic test of a removable partial denture (RPD) was undertaken to study the wear characteristic. RESULTS: The dental model could bear the maximum fracture strength of 4268.3 N. Seven positive and two negative effects of the design methods were produced. The maximum fracture strength of the FPDs were 1331.2 N, 1356.7 N, and 1987.7 N. The wear facets of the RPD in the dynamic denture test were distributed in three regions. CONCLUSIONS: The force capacity of the full-contact dental model allows the application of static denture tests. The dental model provides improvements in fixture design, removable design, and replica design for the testing operations. The dental model is recommended more in the dynamic test than in the static test.

Prying reduction with mosquito forceps versus limited open reduction for irreducible distal radius-ulna fractures in older children: a retrospective study.

BACKGROUND: There are disputes about which reduction technique should be adopted in treatment of distal radius-ulna fractures in older children who failed to achieve manual reduction. This study compared clinical effects between prying reduction with mosquito forceps (PRMF) and limited open reduction (LOR) of treating irreducible distal radius-ulna fractures in older children. METHODS: One hundred ten children with irreducible distal radius-ulna fractures were selected from January 2015 to December 2017 in Xi'an Hong Hui hospital. Retrospective analysis was performed. According to different reduction techniques, these children were divided into PRMF group (59 cases) and LOR group (51 cases). All children were treated with percutaneous Kirschner wire fixation and external fixation with plaster. Operation indexes, complications and wrist joint functions were compared between the two groups. RESULTS: Operation time of PRMF group was shorter than that of LOR group (P < 0.05). Incision length in PRMF group was less than that in LOR group (P < 0.05). Bleeding volume of PRMF group was less than that of LOR group (P < 0.05). Incidence of complications in PRMF group was lower than that in LOR group. CONCLUSIONS: Compared with limited open reduction, it has better clinical effects of prying reduction with mosquito forceps in treatment of irreducible distal radius-ulna fractures in older children. This technique has the advantages of simple operation, less trauma, less bleeding and fewer complications, which is worthy of clinical promotion.

Ammonia nitrogen exposure caused structural damages to gill mitochondria of clam Ruditapes philippinarum.

Ammonia nitrogen has been one of the key pollution indicators along the Chinese coastline for quite a few years. Our previous studies have proved that ammonia nitrogen is harmful for Ruditapes philippinarum clam in several aspects. Environmental concentrations of ammonia nitrogen were found to significantly decrease ATP contents and disturb ATP metabolism, in addition to reducing the potential across the mitochondrial membrane in clam gill tissues. Accordingly, mitochondrion is considered as one of the target organelles of ammonia nitrogen toxicity in clams. However, there is a lack of direct evidence to prove it. In order to reveal detail information of ammonia nitrogen toxicity on clam mitochondria and screen the related biomarker to indicate ammonia nitrogen pollution, mitochondrial parameters in gill tissues including swelling, mtDNA copy number and marker enzyme (succinic dehydrogenase, SDH) activity were measured after the clams were exposed to 0.1 mg/L and 0.5 mg/L ammonia nitrogen for 3 days and 21 days, respectively. Moreover, adverse effects of ammonia nitrogen exposure on clam mitochondrial ultra-structures, mitochondrial swelling and division were also discriminated under transmission electron microscope (TEM). Final results showed that ammonia nitrogen exposure to both concentrations significantly induced mitochondrial swelling, reduced the number of mitochondria and messed their normal structure, decreased the number of mtDNA copies and down-regulated SDH activity, all in a concentration and duration dependent manner. So, the present study helps us to better understand the structural damage of ammonia nitrogen on mitochondria in clam gill cells and provides fundamental data for ammonia nitrogen control in aquaculture.

Serology characteristics of SARS-CoV-2 infection after exposure and post-symptom onset.

BACKGROUND: Timely diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a prerequisite for treatment and prevention. The serology characteristics and complement diagnosis value of the antibody test to RNA test need to be demonstrated. METHOD: Serial sera of 80 patients with PCR-confirmed coronavirus disease 2019 (COVID-19) were collected at the First Affiliated Hospital of Zhejiang University, Hangzhou, China. Total antibody (Ab), IgM and IgG antibodies against SARS-CoV-2 were detected, and the antibody dynamics during the infection were described. RESULTS: The seroconversion rates for Ab, IgM and IgG were 98.8%, 93.8% and 93.8%, respectively. The first detectible serology marker was Ab, followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20 days post exposure (d.p.e.) or 9, 10 and 12 days post onset (d.p.o.), respectively. The antibody levels increased rapidly beginning at 6 d.p.o. and were accompanied by a decline in viral load. For patients in the early stage of illness (0-7 d.p.o), Ab showed the highest sensitivity (64.1%) compared with IgM and IgG (33.3% for both; p<0.001). The sensitivities of Ab, IgM and IgG increased to 100%, 96.7% and 93.3%, respectively, 2 weeks later. When the same antibody type was detected, no significant difference was observed between enzyme-linked immunosorbent assays and other forms of immunoassays. CONCLUSIONS: A typical acute antibody response is induced during SARS-CoV-2 infection. Serology testing provides an important complement to RNA testing in the later stages of illness for pathogenic-specific diagnosis and helpful information to evaluate the adapted immunity status of patients.

Genome-wide transcriptome and proteome profiles indicate an active role of alternative splicing during de-etiolation of maize seedlings.

MAIN CONCLUSION: AS events affect genes encoding protein domain composition and make the single gene produce more proteins with a certain number of genes to satisfy the establishment of photosynthesis during de-etiolation. The drastic switch from skotomorphogenic to photomorphogenic development is an excellent system to elucidate rapid developmental responses to environmental stimuli in plants. To decipher the effects of different light wavelengths on de-etiolation, we illuminated etiolated maize seedlings with blue, red, blue-red mixed and white light, respectively. We found that blue light alone has the strongest effect on photomorphogenesis and that this effect can be attributed to the higher number and expression levels of photosynthesis and chlorosynthesis proteins. Deep sequencing-based transcriptome analysis revealed gene expression changes under different light treatments and a genome-wide alteration in alternative splicing (AS) profiles. We discovered 41,188 novel transcript isoforms for annotated genes, which increases the percentage of multi-exon genes with AS to 63% in maize. We provide peptide support for all defined types of AS, especially retained introns. Further in silico prediction revealed that 58.2% of retained introns have changes in domains compared with their most similar annotated protein isoform. This suggests that AS acts as a protein function switch allowing rapid light response through the addition or removal of functional domains. The richness of novel transcripts and protein isoforms also demonstrates the potential and importance of integrating proteomics into genome annotation in maize.

A novel putative betapartitivirus isolated from the plant-pathogenic fungus Rhizoctonia solani.

In this study, we describe the genome sequence of a novel double-stranded RNA (dsRNA) mycovirus, designated as "Rhizoctonia solani partitivirus 15" (RsPV15), from the phytopathogenic fungus Rhizoctonia solani. RsPV15 consists of two genomic double-stranded RNA segments, dsRNA-1 and dsRNA-2, which are 2433 bp and 2350 bp long, respectively. Each of the dsRNA segments contains a single open reading frame, encoding the putative RNA-dependent RNA polymerase and coat protein, respectively. Homology searches and phylogenetic analysis suggested that RsPV15 is a new member of the genus Betapartitivirus within the family Partitiviridae.

Survey and analysis of the nutritional status in hospitalized patients with malignant gastric tumors and its influence on the quality of life.

BACKGROUND/OBJECTIVES: The assessment of nutritional status and the quality of life in patients with gastric cancer has become one of the important goals of current clinical treatment. The purpose of this study was to assess the nutritional status in hospitalized gastric cancer patients by using patient-generated subjective global assessment (PG-SGA) and to analyze the influence of nutritional status on the patients' quality of life (QOL). METHODS: We reviewed the pathological diagnosis of gastric cancer for 2322 hospitalized patients using PG-SGA to assess their nutritional status and collected data on clinical symptoms, the anthropometric parameters (height, weight, body mass index (BMI), mid-arm circumference (MAC), triceps skin-fold thickness (TSF), and hand-grip strength (HGS). We also collected laboratory data (prealbumin, albumin, hemoglobin) within 48 h after the patient was admitted to the hospital. The 30-item European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30) was used for QOL assessment in all patients. RESULTS: By using PG-SGA, we found 80.4% of the patients were malnourished (score ≥ 4) and 45.1% of the patients required urgent nutritional support (score ≥ 9). In univariate analysis, old age (> 65 years, p < 0.001), female (p = 0.007), residence in a village (p = 0.004), a lower level of education (p < 0.001), and self-paying (p < 0.001) were indicated as risk factors of patients with gastric cancer to be suffering from severe malnutrition. There was a negative correlation between PG-SGA and various nutritional parameters (p < 0.05). The quality of life was significantly different in gastric cancer patients with different nutritional status (p < 0.01). CONCLUSION: Malnutrition of hospitalized patients with gastric cancer in China is common and seriously affects the patients' quality of life. The nutritional status should be evaluated in a timely manner and reasonable nutritional intervention should be provided as soon as possible. The PG-SGA was fit for using as a clinical nutrition assessment method, being worthy of clinical application.

[Design and performance analysis of elastic temporomandibular joint structure of biomimetic masticatory robot].

Masticatory robots have a broad application prospect in the field of denture material tests and mandible rehabilitation. Mechanism type of temporomandibular joint structure is an important factor influencing the performance of the masticatory robot. In view of the wide application of elastic components in the field of the biomimetic robot, an elastic component was adopted to simulate the buffering characteristics of the temporomandibular joint disc and formed the elastic temporomandibular joint structure on the basis of point-contact high pair. Secondly, the influences of the elastic temporomandibular joint structure (on mechanism degree, kinematics, dynamics, etc.) were discussed. The position and velocity of the temporomandibular joint were analyzed based on geometric constraints of the joint surface, and the dynamic analysis based on the Lagrange equation was carried out. Finally, the influence of the preload and stiffness of the elastic component was analyzed by the response surface method. The results showed that the elastic temporomandibular joint structure could effectively guarantee the flexible movement and stable force of the joint. The elastic joint structure proposed in this paper further improves the biomimetic behavior of masticatory robots. It provides new ideas for the biomimetic design of viscoelastic joint discs.

[Stress analysis of the molar with the all-ceramic crown prosthesis based on centric occlusal optimization].

Stress distribution of denture is an important criterion to evaluate the reasonableness of technological parameters, and the bite force derived from the antagonist is the critical load condition for the calculation of stress distribution. In order to improve the accuracy of stress distribution as much as possible, all-ceramic crown of the mandibular first molar with centric occlusion was taken as the research object, and a bite force loading method reflecting the actual occlusal situation was adopted. Firstly, raster scanning and three dimensional reconstruction of the occlusal surface of molars in the standard dental model were carried out. Meanwhile, the surface modeling of the bonding surface was carried out according to the preparation process. Secondly, the parametric occlusal analysis program was developed with the help of OFA function library, and the genetic algorithm was used to optimize the mandibular centric position. Finally, both the optimized case of the mesh model based on the results of occlusal optimization and the referenced case according to the cusp-fossa contact characteristics were designed. The stress distribution was analyzed and compared by using Abaqus software. The results showed that the genetic algorithm was suitable for solving the occlusal optimization problem. Compared with the reference case, the optimized case had smaller maximum stress and more uniform stress distribution characteristics. The proposed method further improves the stress accuracy of the prosthesis in the finite element model. Also, it provides a new idea for stress analysis of other joints in human body.

[Equivalent modeling and evaluation of molars using point-contact higher kinematic pair based on occlusal dynamic analysis].

As a representative part of the oral system and masticatory robot system, the modeling method of the dental model is an important factor influencing the accuracy of the multi-body dynamic model. Taking the right first molars of the masticatory robot as the research object, an equivalent model, point-contact higher kinematic pair composed of v-shaped surface and sphere surface, was proposed. Firstly, the finite element method was used to analyze the occlusal dynamics of the original model in three static contact cases (intrusive contact, centric occlusion, and extrusive contact) and one dynamic chewing case, and the expected bite force was obtained. Secondly, the Hertz contact model was adopted to establish the analytical expression of the bite force of the equivalent model in three static contact cases. The normal vectors and contact stiffness in the expression were designed according to the expected bite force. Finally, the bite force performance of the equivalent model in three static contact cases and one dynamic chewing case was evaluated. The results showed that the equivalent model could achieve the equivalent bite force of 8 expected items in the static contact cases. Meanwhile, the bite force in the early and late stages of the dynamic chewing case coincides well with the original model. In the middle stage, a certain degree of impact is introduced, but it can be weakened by subsequent trajectory planning. The equivalent modeling scheme of the dental model proposed in this paper further improves the accuracy of the dynamic model of the multi-body system. It provides a new idea for the dynamic modeling of other complex human contacts.

Tissue distribution and functional characterization of mytimacin-4 in Mytilus galloprovincialis.

Antimicrobial peptides (AMPs) play fundamental roles in the innate immunity of invertebrates. Mytimacin-4 is a kind of AMP gene previously sequenced from Mytilus galloprovincialis based on an identified EST sequence in our lab. In the present study, the tissue distribution and antimicrobial activities of mytimacin-4 were further investigated. A qRT-PCR analysis revealed that mytimacin-4 transcripts were constitutively expressed in all of the tested tissues of M. galloprovincialis, with the highest expression level in the posterior adductor muscle. After challenge by Vibrio anguillarum, the expression level of mytimacin-4 gene was significantly increased at 24 h (P < 0.05) in the mantle and increased at 48 h (P < 0.05) in the posterior adductor muscle. This finding suggested that mytimacin-4 transcripts were inducible upon pathogen infection. A minimal inhibitory concentration (MIC) assay indicated that recombinant mytimacin-4 protein had potent antimicrobial activities against gram-positive and gram-negative bacteria. Among the tested microorganisms, mytimacin-4 protein exhibited strong inhibition activities against Bacillus subtilis and Vibrio parahaemolyticus with MICs of 0.315 µM and 0.62 µM, respectively. This study provides for the first time direct evidence of antimicrobial action of mytimacin-4 in M. galloprovincialis.

Digital gene expression analysis in the gills of Ruditapes philippinarum after nitrite exposure.

Due to the overload of pollutants from highly intensive anthropic activities, nitrite accumulates in offshore seawater and has been a long-lasting pollutant to the healthy aquaculture of the mollusk. In the present study, Ruditapes philippinarum was used as the target bivalve to receive nitrite exposure at environmental concentration for 1 and 7 days. Differentially expressed genes (DEGs) were detected and analyzed by a digital gene expression (DGE) approach to describe the toxicity of nitrite on the bivalve at the gene level. In the N1 group, 185 DEGs were generated and enriched in six Gene Ontology (GO) terms, including oxidoreductase activity, heme binding, tetrapyrrole binding, iron ion binding, metal binding and cation binding. The DEGs in the N1 group were also enriched in two Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, e.g., arachidonic acid metabolism and ovarian steroidogenesis. In the N7 group, 81 DEGs were generated without any GO enrichment but were enriched in five KEGG pathways, including protein processing in the endoplasmic reticulum, protein export, prion diseases, thyroid hormone synthesis and arachidonic acid metabolism. This suggested that nitrite exposure might cause adverse effects to the clams in several aspects, including oxidative damage, depressed immunity, and disorders in cell proliferation, hormone metabolism and tissue regeneration. Evaluation of oxidative stress indicated that nitrite exposure actually induced redox state imbalance by enhancing the contents of thiobarbituric acid reactive substances (TBARSs) and glutathione (GSH), and the activity of glutathione peroxidase (GSH-PX) but not superoxide dismutase (SOD). These results will provide valuable gene references for further study on the toxicology mechanism of bivalves under environmental nitrite stress.

Low ketolytic enzyme levels in tumors predict ketogenic diet responses in cancer cell lines in vitro and in vivo.

The ketogenic diet (KD) is a high-fat, very-low-carbohydrate diet that triggers a fasting state by decreasing glucose and increasing ketone bodies, such as ß-hydroxybutyrate (ßHB). In experimental models and clinical trials, the KD has shown anti-tumor effects, possibly by reducing energy supplies to cells, which damage the tumor microenvironment and inhibit tumor growth. Here, we determined expression levels of genes encoding the ketolytic enzymes 3-hydroxybutyrate dehydrogenase 1 (BDH1) and succinyl-CoA: 3-oxoacid CoA transferase 1 (OXCT1) in 33 human cancer cell lines. We then selected two representative lines, HeLa and PANC-1, for in vivo examination of KD sensitivity in tumors with high or low expression, respectively, of these two enzymes. In mice with HeLa xenografts, the KD increased tumor growth and mouse survival decreased, possibly because these tumors actively consumed ketone bodies as an energy source. Conversely, the KD significantly inhibited growth of PANC-1 xenograft tumors. ßHB added to each cell culture significantly increased proliferation of HeLa cells, but not PANCI-1 cells. Downregulation of both BDH1 and OXCT1 rendered HeLa cells sensitive to the KD in vitro and in vivo. Tumors with low ketolytic enzyme expression may be unable to metabolize ketone bodies, thus predicting a better response to KD therapy.

A defensin-like antimicrobial peptide from the manila clam Ruditapes philippinarum: Investigation of the antibacterial activities and mode of action.

Defensins are small cysteine-rich cationic proteins that are ubiquitously present in both vertebrates and invertebrates and constitute the front line of host innate immunity. In the present study, a defensin-like antimicrobial peptide (designed as RpdefB) was identified and characterized from the manila clam Ruditapes philippinarum. The open reading frame of RpdefB encoded a 70-amino acid polypeptide with a calculated molecular mass of 7.5 kDa and isoelectric point of 8.16. Multiple alignments and phylogenetic analysis strongly suggested that RpdefB was a new member of the defensin family. In non-stimulated clams, RpdefB transcripts were constitutively expressed in all five tested tissues, especially in the hepatopancreas. After Vibrio anguillarum challenge, expression of RpdefB mRNA in hemocytes was significantly up-regulated at 6 h, 12 h and 72 h. The synthetic peptide RpdefB showed high antibacterial activity against the Gram-negative bacterium Vibrio splendidus. Moreover, membrane integrity analysis revealed that RpdefB increased the membrane permeability of Escherichia coli and then resulted in cell death. Overall, our results suggested that RpdefB played an important role in the elimination of invading bacterium, perhaps through membrane-disruptive activity.