[Carrier screening for 223 monogenic diseases in Chinese population: a multi-center study in 33 104 individuals].

OBJECTIVE: To investigate the epidemiological characteristics and mutation spectrum of monogenic diseases in Chinese population through a large-scale, multicenter carrier screening. METHODS: This study was conducted among a total of 33 104 participants (16 610 females) from 12 clinical centers across China.Carrier status for 223 genes was analyzed using high-throughput sequencing and different PCR methods. RESULTS: The overall combined carrier frequency was 55.58% for 197 autosomal genes and 1.84% for 26 X-linked genes in these participants.Among the 16 669 families, 874 at-risk couples (5.24%) were identified.Specifically, 584 couples (3.50%) were at risk for autosomal genes, 306(1.84%) for X-linked genes, and 16 for both autosomal and X-linked genes.The most frequently detected autosomal at-risk genes included GJB2(autosomal recessive deafness type 1A, 393 couples), HBA1/HBA2(α-thalassemia, 36 couples), PAH (phenylketonuria, 14 couples), and SMN1(spinal muscular atrophy, 14 couples).The most frequently detected X-linked at-risk genes were G6PD (G6PD deficiency, 236 couples), DMD (Duchenne muscular dystrophy, 23 couples), and FMR1(fragile X syndrome, 17 couples).After excluding GJB2 c.109G>A, the detection rate of at-risk couples was 3.91%(651/16 669), which was lowered to 1.72%(287/16 669) after further excluding G6PD.The theoretical incidence rate of severe monogenic birth defects was approximately 4.35‰(72.5/16 669).Screening for a battery of the top 22 most frequent genes in the at-risk couples could detect over 95% of at-risk couples, while screening for the top 54 genes further increased the detection rate to over 99%. CONCLUSION: This study reveals the carrier frequencies of 223 monogenic genetic disorders in the Chinese population and provides evidence for carrier screening strategy development and panel design tailored to the Chinese population.In carrier testing, genetic counseling for specific genes or gene variants can be challenging, and the couples need to be informed of these difficulties before testing and provided with options for not screening these genes or gene variants.

[Association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40-89 in selected areas of China].

Objective: To investigate the association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40 to 89 years in selected areas of China. Methods: The research was based on the survey of the impact of soil quality of agricultural land on human health in typical areas conducted in 2019-2020. A total of 5 600 middle-aged and older adults aged 40 to 89 years were included by using a multi-stage stratified random sampling method. Baseline characteristics of the subjects were collected and physical examinations were performed. Random midstream urine was collected to measure urinary cadmium and urinary creatinine and fasting venous blood was collected to measure the leukocyte count, neutrophil count, lymphocyte count, monocyte count and eosinophil count. The linear mixed effect model was used to analyse the association of urinary cadmium levels with leukocyte classification counts, and the dose-response relationship between them was analyzed by using the restricted cubic spline (RCS) function. Results: The age of the subjects was (63.17±12.02) years; 2 851 (50.91%) were males; and the M (Q1, Q3) of urinary creatinine-corrected urinary cadmium levels was 2.69 (1.52, 4.69) µg/g·creatinine. After adjusting for confounding factors, the results of linear mixed effects model analysis showed that for each 1-unit increase in urinary creatinine-corrected urinary cadmium level, the percentage change [% (95%CI)] of leukocyte count and lymphocyte count was -1.70% (-2.61%, -0.79%) and -1.57% (-2.86%, -0.26%), respectively. RCS function showed a negative linear relationship between urinary creatinine-corrected urinary cadmium levels and leukocyte counts and lymphocyte counts, respectively (all Pnon-linear>0.05). Conclusion: Urinary cadmium levels are negatively associated with leukocyte count and lymphocyte count among middle-aged and older adults aged 40 to 89 years in selected areas of China.

[Application of machine vision image processing technology in dental implant surgery].

Machine vision image processing technology is extensively employed in the medical realm, particularly in dynamic navigation and robotic systems for oral implantology. It plays a pivotal role in assisting clinicians with precise implant placements, enhancing the predictability of implant restorations. The fundamental principles of machine vision image processing technology utilized in dynamic navigation and robotic systems for oral implantology primarily encompass spatial positioning and registration. However, due to variations in technical principles among different systems, their workflows and technical nuances exhibit distinctive characteristics. Therefore, commencing from the principles of spatial positioning and registration in machine vision image processing technology. This article delves into the current application landscape of machine vision in dynamic navigation and robotics for oral implantology. Its objective is to furnish valuable insights for the clinical implementation of machine vision-assisted implant technology.

[Promoting the healthy development of the wound repair discipline system with local conditions and Chinese characteristics].

The construction of wound repair discipline system with Chinese characteristics is a process of continuous optimization and improvement. Due to the different conditions and the situations that vary widely from region to region and from hospital to hospital, various forms of wound repair specialty or consortium will exist within a period of time and to a extent plays a key role in promoting the construction of the wound repair discipline system with Chinese characteristics. This article introduced several kinds of construction modes of wound repair specialty or regional alliance of wound repair specialty in recent years. Their successful experience is worth learning and drawing lessons from.

In ovo injection of AZD6244 suppresses feather follicle development by the inhibition of ERK and Wnt/ß-catenin pathways in goose embryos (Anser cygnoides).

1. Feathers are an important product from poultry, and the state of feather growth and development plays an important role in their economic value.2. In total, 120 eggs were selected for immunoblotting and immunolocalisation experiments of ERK and ß-catenin proteins in different developmental stages of goose embryos. The ERK protein was highly expressed in the early stage of goose embryo development, while ß-catenin protein was highly expressed in the middle stage of embryo development.3. The 120 eggs were divided into four treatment groups, including an uninjected group (BLANK), a group injected with 100 µl of cosolvent (CK), a group injected with 100 µl of AZD6244 containing cosolvent in a dose of 5 mg/kg AZD6244 containing cosolvent (AZD5) and a group injected with 100 µl of AZD6244 containing cosolvent in a dose of 15 mg/kg AZD6244 containing cosolvent (AZD15). The eggs were injected on the ninth day of embryonic development (E9). Samples were collected at E21.5 to observe feather width, feather follicle diameter, ERK and Wnt/ß-catenin pathway protein expression.4. The AZD5 and AZD15 doses were within the embryonic safety range compared to the BLANK and CK groups and had no significant effect on the survival rate and weight at the inflection point, but significantly reduced the feather width and feather follicle diameter (p < 0.05). The AZD6244 treatment inhibited ERK protein phosphorylation levels and blocked the Wnt/ß-catenin pathway, which in turn significantly down-regulated the expression levels of FZD4, ß-catenin, TCF4 and LEF1 (p < 0.05), with an inhibitory effect in the AZD15 group being more significant. The immunohistochemical results of ß-catenin and p-ERK were consistent with Western blot results.5. The small molecule inhibitor AZD6244 regulated the growth and development of feather follicles in goose embryos by the ERK and Wnt/ß-catenin pathways.

[High-risk sexual behaviors of HIV/AIDS and related factors in young students in Guangzhou].

Objective: To explore high-risk sexual behaviors of HIV/AIDS and related factors in young students in Guangzhou. Methods: A cross-sectional survey was conducted in 5 different types of Guangzhou colleges by convenience sampling with minimum number of classes per grade and 600 samples per school from September to November 2021. The R 4.2.2 software was used to consolidate databases. Simultaneously, a logistic regression model and a decision tree algorithm model, stratifying by whether sexual behaviors had occurred before, were constructed. In each layer, the prediction performance of the two models was evaluated through area under receiver operating characteristic and the confusion matrix, and then the model with high prediction performance was retained. Results: A total of 7 346 students were surveyed. The proportion of the respondents reporting sexual experience were 9.08% (667/7 346), in whom 26.24% (175/667) had risky sexual activity in the past year. The decision tree algorithm model performs well in predicting whether high-risk sexual behaviors have occurred in the past year. When the complexity parameter value is 0.018, and nsplit reaches 4, which means there are 5 leaf nodes in the model, the cross error of the tree will be the smallest. The first best grouping variable in the decision tree was whether to use condoms throughout the first sexual behavior. If condoms were used at their sexual debut, but homosexual practices have occurred in the past year, the probability of risky sexual behavior will increase. If homosexual practices have not occurred in the past year, but the age of sexual debut was below 18 years old while the period of HIV education was after high school, the probability of risk sexual behavior will also increase. Conclusions: AIDS-related risky behaviors of young students still deserved attention. The experience of sexual debut and whether AIDS-related health education has been received before the sexual debut were significant predictors for the occurrence of high-risk sexual behavior. The decision tree algorithm model has particular applicability for predicting and screening potential risk populations.

[Perception of HIV-related behavior and influencing factors among young students in Guangzhou].

Objective: To investigate the risk perception for risky behavior of HIV/AIDS infection among young students and to analyze the related influencing factors. Methods: A cross-sectional survey was conducted in 5 different types of Guangzhou colleges from September to November 2021, in which convenience sampling and a minimum number of classes per grade and 600 samples per school were used according to the national unity program. Disordered multi-classification logistic regression was used to construct a risk perception model and analyze influencing factors in different risk perception levels. Results: A total of 7 346 young students were surveyed, and most rated themselves at low risk of HIV/AIDS infections (90.58%, 6 654/7 346). A total of 89.10% (6 545/7 346) of subjects' perception of their HIV/AIDS infection risk was consistent with their risk behavior, while 10.90% (801/7 346) was inconsistent. Among those inconsistent subjects, 19.10% (153/801) showed underestimating their risk , while 80.90% (648/801) seen overestimating their risk. Disordered multi-classification logistic regression analysis showed that, after controlling for other factors, compared with the non-sexual group, respondents whose first sex age under 18 had a higher rate of underestimating their risk of infection (OR=129.39, 95%CI: 73.28-228.48), as well as a higher rate of overestimated their risk of infection (OR=1.76, 95%CI: 1.04-2.99). First sexual intercourse at age 18 or older was a risk factor for underestimating risk (OR=70.56, 95%CI: 42.72-116.53), but was not statistically associated with overestimating risk. Being female, other school type, non-heterosexual orientation, and self-rated HIV-related knowledge as fair or no knowledge were risk factors for overestimating risk but were not statistically associated with underestimating risk. Conclusions: Overall, young students in universities of Guangzhou have a good risk perception of HIV/AIDS infection. Individual factors, education factors and sexual experience will influence students' risk perception of HIV/AIDS infection. Raising the awareness rate of HIV/AIDS knowledge and delaying the age of first sexual intercourse will improve the risk perception ability of young students.

[Research progress on the mechanism of action of mitophagy in the occurrence and development of liver cancer].

Mitophagy, as an important link in maintaining mitochondrial homeostasis and environmental homeostasis in the liver, can remove damaged mitochondria and provide energy through autophagy and other processes. Additionally, it plays a dual role in the occurrence and development of liver cancer and can affect the therapeutic effect of liver cancer through a variety of signaling pathways. This article reviews the relationship between mitophagy and hepatitis B virus infection, liver cancer occurrence and development, liver cancer stem cells, mitochondrial division and fusion, therapeutic resistance and invasiveness of liver cancer, and other aspects.

[Deep learning-assisted construction of three-dimensional face midsagittal plane based on point clouds].

Objective: To establish an intelligent registration algorithm under the framework of original-mirror alignment algorithm to construct three-dimensional(3D) facial midsagittal plane automatically. Dynamic Graph Registration Network (DGRNet) was established to realize the intelligent registration, in order to provide a reference for clinical digital design and analysis. Methods: Two hundred clinical patients without significant facial deformities were collected from October 2020 to October 2022 at Peking University School and Hospital of Stomatology. The DGRNet consists of constructing the feature vectors of key points in point original and mirror point clouds (X, Y), obtaining the correspondence of key points, and calculating the rotation and translation by singular value decomposition. Original and mirror point clouds were registrated and united. The principal component analysis (PCA) algorithm was used to obtain the DGRNet alignment midsagittal plane. The model was evaluated based on the coefficient of determination (R2) index for the translation and rotation matrix of test set. The angle error was evaluated on the 3D facial midsagittal plane constructed by the DGRNet alignment midsagittal plane and the iterative closet point(ICP) alignment midsagittal plane for 50 cases of clinical facial data. Results: The average angle error of the DGRNet alignment midsagittal plane and ICP alignment midsagittal plane was 1.05°±0.56°, and the minimum angle error was only 0.13°. The successful detection rate was 78%(39/50) within 1.50° and 90% (45/50)within 2.00°. Conclusions: This study proposes a new solution for the construction of 3D facial midsagittal plane based on the DGRNet alignment method with intelligent registration, which can improve the efficiency and effectiveness of treatment to some extent.

[Mitochondrial pyruvate carrier deficiency: 3 cases report and literature review].

Objective: To analyze the clinical and genetic features of patients with mitochondrial pyruvate carrier deficiency (MPYCD). Methods: This was a case series research. The clinical data, genetic characteristics, and glutamine treatment efficacy of 3 patients diagnosed with MPYCD at the Department of Neurology, Beijing Children's Hospital, Capital Medical University and Department of Pediatrics, Guizhou Provincial People's Hospital, from August 2019 to June 2023 were retrospectively collected. A literature search with "MPC1 gene" "MPC2 gene and" "mitochondrial pyruvate carrier deficiency" as keywords was conducted at the Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure (CNKI) and PubMed (up to June 2023). Clinical and genetic characteristics of patients with MPYCD were summarized. Results: Case 1 was a 3 years and 11 months old boy, while case 2 was a 4 years and 10 months old boy and case 3 was an 8 years and 9 months old girl. Case 2 and case 3 were siblings from one consanguineous family. All 3 patients presented with general developmental delay, growth failure and elevated serum lactate. Cranial magnetic resonance imaging (MRI) showed subtle bilateral symmetrical T2 signal hyperintensity in basal ganglia and thalamus in case 1, but normal in case 2 and 3. Trio-WES revealed case 1 harboring compound heterozygous missense variants c.208G>A (p.Ala70Thr) and c.290G>A (p.Arg97Gln) in MPC1 gene, while case 2 and 3 revealed a homozygous variant c.290G>A (p.Arg97Gln) in the same gene. All 3 cases were diagnosecl as MPYCD. Clinical symptoms including motor ability, cognition and activity endurance were improved in these 3 patients after taking glutamine for 2 years. A total of 5 articles published in English were reviewed, and no Chinese literature was found. Including these 3 cases, 15 cases were enrolled for analysis. Eleven patients carried MPC1 gene variants and 4 cases carried MPC2 gene variants. Except for 3 cases died during prenatal period, 9 of 12 enrolled born cases were onset before 6 months old. The most common clinical symptoms were mental and motor general developmental delay, microcephaly, growth failure and hypotonia. All patients had elevated blood lactate and pyruvate, but the ratio of lactate/pyruvate was normal. Seven patients performed cranial MRI, 3 exhibited non-specific changes, 2 showed bilateral symmetrical T2 signal hyperintensity in basal ganglia and thalamus, and 3 were normal. A total of 5 MPC1 gene missense variants and 2 MPC2 gene variants were identified in 15 cases. Conclusions: Onset age of patients with MPYCD is usually within 6 months. The main clinical characteristics are developmental delay, microcephaly and growth failure, accompanied by increased serum lactate and pyruvate. Glutamine supplement could lead to clinical improvements.

[Ten key points in the high-quality construction and development of the disciplinary system of wound repair with Chinese characteristics].

Phased major results with construction of the disciplinary system of wound repair with Chinese characteristics have been achieved in the past 30 years. However, some problems in institutional issues still affect the development of the discipline. In this paper, 10 aspects of the impact of discipline construction are put forward which may offer reference for high-quality construction of the disciplinary system of wound repair with Chinese characteristics.

[Research advances of stem cell-based tissue engineering repair materials in promoting the healing of chronic refractory wounds on the body surface].

Repairing chronic refractory wounds on the body surface is a complex medical problem involving all stages of wound healing. In recent years, stem cells (SCs) and tissue engineering (TE) have brought hope for repairing chronic refractory wounds. SCs have excellent regenerative and paracrine effects; various TE strategies have the potential to repair chronic refractory wounds on the body surface and also improve the delivery efficiency of SCs. This article reviews the pathological characteristics of chronic refractory wounds, SCs used to repair chronic refractory wounds, and SC-based TE wound repair strategies.

[Role and prospect of regenerative medicine in early treatment of combat trauma].

The regenerative medicine has made great breakthrough in the repair of combat trauma, showing broad prospects, while the method of regenerative medicine applied in the early treatment of combat trauma is not yet clear. The early treatment of combat trauma includes strict control of bleeding, a large amount of blood transfusion, alleviation of acidosis, and correction of hypothermia and improvement of coagulation dysfunction, etc. This paper focuses on the bio-engineered blood, research and development of homeostatic materials, control of inflammation/infection, regulation of immunity, protection of important organs, establishment of military medical model, research and development of biosensors and drugs, and preventive application of stem cell bank in regenerative and tissue engineering in defense medicine to summarize the role of regenerative medicine in the early treatment of combat trauma, hoping to improve the overall treatment level of combat trauma.

[Value of C-peptide-based insulin resistance index for evaluating correlation between insulin resistance and serum uric acid level in individuals undergoing health examination].

OBJECTIVE: To investigate the value of C-peptide-based insulin resistance index in evaluating the correlation between insulin resistance and serum uric acid (Ua) level in subjects undergoing health examination. METHODS: The data of 46 017 subjects undergoing health examination were retrospectively collected from the Second Medical Center of PLA General Hospital from January, 2017 to December, 2021. The subjects were divided into Ua≤420 µmol/L group and Ua>420 µmol/L group for comparison of HOMA insulin resistance index (HOMA2-IR) and HOMA insulin resistance-C peptide (HOMA2 IR-CP). The correlations of HOMA2-IR and HOMA2 IR-CP with Ua level were analyzed using Pearson correlation analysis and linear regression analysis. Hierarchical interaction analysis was conducted to assess the differences in the association between insulin resistance index and Ua level in different subgroups. The ROC curve was used to evaluate the predictive ability of insulin resistance index for an increased Ua level. RESULTS: The levels of HOMA2-IR and HOMA2 IR-CP were significantly lower in Ua≤420 µmol/L group than in Ua>420 µmol/L group. Univariate Pearson correlation analysis showed a weak correlation of HOMA2-IR with Ua (r=0.262, P<0.001) and moderate correlation of HOMA2 IR-CP with Ua (r=0.409, P<0.001). Multivariate linear regression analysis, after adjustment for confounding factors, demonstrated that HOMA2-IR (R2=0.445, P<0.001) and HOMA2 IR-CP (R2=0.461, P<0.001) were both factors affecting Ua level. Hierarchical interaction analysis showed that the association of insulin resistance index with Ua level varied significantly with gender, age, and glucose metabolism (P<0.001). ROC curve showed that the areas under the curve predicted an increased Ua level by HOMA2-IR and HOMA2 IR-CP were 0.662 and 0.722, respectively. CONCLUSIONS: HOMA2 IR-CP is a more accurate indicator for assessing the correlation between insulin resistance and Ua level.

Effect of antioxidant procyanidin b2 (pcb2) on ovine oocyte developmental potential in response to in vitro maturation (ivm) and vitrification stress.

BACKGROUND: It was demonstrated that external stress, such as in vitro maturation (IVM) and vitrification process can induce significantly reduced development capacity in oocytes. Previous studies indicated that antioxidants play a pivotal part in the acquisition of adaptation in changed conditions. At present, the role of the natural potent antioxidant PCB2 in response to IVM and vitrification during ovine oocyte manipulation has not been explored. OBJECTIVE: To investigate whether PCB2 treatment could improve the developmental potential of ovine oocytes under IVM and vitrification stimuli. MATERIALS AND METHODS: The experiment was divided into two parts. Firstly, the effect of PCB2 on the development of oocytes during IVM was evaluated. Un-supplemented and 5 ug per mL PCB2-supplemented in the IVM solution were considered as control and experimental groups (C + 5 ug per mL PCB2). The polar body extrusion (PBE) rate, mitochondrial membrane potential (MMP), ATP, reactive oxygen species (ROS) levels and early apoptosis of oocytes were measured after IVM. Secondly, we further determine whether PCB2 could improve oocyte quality under vitrification stress. The survival rate, PBE rate and early apoptosis of oocytes were compared between fresh group, vitrified group and 5 ug per mL PCB2-supplemented in the IVM solution after vitrification (V + 5 ug per mL PCB2). RESULTS: Compared to the control group, adding PCB2 significantly increased PBE rate (79.4% vs. 62.8%, P < 0.01) and MMP level (1.9 +/- 0.08 vs. 1.3 +/- 0.04, P < 0.01), and decreased ROS level (47.1 +/- 6.3 vs. 145.3 +/- 8.9, P < 0.01). However, there was no significant difference in ATP content and early apoptosis. Compared to the fresh group, vitrification significantly reduced oocytes viability (43.0% vs. 90.8%, P < 0.01) as well as PBE rate (24.2% vs. 60.6%, P < 0.05). However, 5 ug per mL PCB2-supplemention during maturation had no effect on survival, PBE or early apoptosis in vitrified oocytes. CONCLUSION: PCB2 could effectively antagonise the oxidative stress during IVM and promote oocyte development. DOI: 10.54680/fr23210110412.

Impact of shift work on dementia: a systematic review and dose-response meta-analysis.

OBJECTIVES: Although shift work has been reported as having a link to dementia, evidence remains inconsistent, and a comprehensive dose-response meta-analysis of the association is still lacking. We therefore conducted this meta-analysis to explore the association between shift work and the risk of dementia. STUDY DESIGN: Systematic review and dose-response meta-analysis. METHODS: PubMed, Embase, and Web of Science databases were systematically searched. Fixed or random-effects models were used to estimate the summary relative risks (RRs) and 95% confidence intervals (95% CIs). Generalized least squares regression was used to estimate dose-response associations, and restricted cubic splines were used to examine possible linear or non-linear associations. RESULTS: Five articles (10 studies) with 72,999 participants and 23,067 cases were eventually included in the meta-analysis. The summary RRs and 95% CIs of dementia risk with shift work and night shift work versus daytime work were 1.13 (95% CI: 1.05-1.21, I2 = 46.70%) and 1.13 (95% CI: 1.03-1.24, I2 = 9.20%), respectively. The risk of dementia increased by 1% (RR = 1.01, 95% CI: 1.01-1.02, I2 = 41.3%) with each 1-year increase in the duration of shift work. We found a non-linear dose-response association between the duration of shift work and the risk of dementia (Pnon-linearity = 0.006). Though the shape of the curve was steeper with the duration of shift work <7 years, the increase was more gradual after 7 years. CONCLUSION: Our findings suggest that shift work may be a risk factor for future dementia and that controlling the length of shift work is a feasible measure that may contribute to prevent dementia.

Effect of replacing corn straw by sweet sorghum silage or whole plant corn silage in sheep diets on rumen fermentation and bacterial flora.

Sweet sorghum silage (SS; Sorghum dochna 'Dochna') has been extensively studied in recent years as a supplementary forage-to-corn silage (CS; Zea mays L.), but there are still relatively few studies on its effects on the rumen environment of sheep. Determining the short-term impact of converting roughage from corn straws to SS compared to CS on rumen fermentation and bacterial population dynamics was the main goal of the current study. Twelve female thin-tailed Han sheep (29.8 ± 1.34 kg) were randomly divided into one of two treatments: concentrate supplemented with SS or CS, respectively. During the 15-day pretest period, concentrate was fed in two separate feedings at 0800 h and 1800 h, and ensure that the animals were all consumed within an hour of being fed. Thereafter, the animals had free access to corn straw. The feeding procedures during the pretest period were the same as during the measurement period. Rumen fluid was collected via sheep esophageal tube on the last day of adaptation phase (1-7 days) and stabilisation phase (8-30 days), respectively. The results showed that there was a similarity in the total concentration of VFA (volatile fatty acid) and the proportions of acetate, propionate, butyrate, and branched-chain VFA (P > 0.05) and microbial diversity indices (P > 0.05) between the two silage groups throughout the experimental period. The concentration of Ammonia nitrogen (P = 0.001) and proportion of valerate (P = 0.028) decreased in the CS and SS groups, respectively. The abundance and predicted function of rumen bacteria in the SS group did not differ significantly (P > 0.05) between the two measurement phases. However, the abundance of Prevotella_1 (P = 0.038) was higher in the CS group than in the SS group at 7 d. The abundances of Firmicutes (P = 0.005) and Ruminococcaceae_NK4A214_group (P = 0.002) increased, while the abundances of Bacteroidetes (P = 0.044), Proteobacteria (P = 0.046), and Prevotella_1 (P = 0.009) decreased in the CS group at 30 d. Genes related to pyruvate metabolism (P = 0.020) were significantly higher at 30 d than at 7 d, whereas purine metabolism (P = 0.007), pyrimidine metabolism (P = 0.007), and metabolic pathways (P = 0.010) were lower at 30 d in the CS group. In conclusion, this study indicated that SS maintained a steady rumen environment, while CS caused high fluctuations in bacterial abundance and predicted function for sheep.

[Analysis of fast-growing culturable bacteria and pathogenic bacteria in the surface water of the northeast coast of Hainan Island in China].

Objective: To obtain the diversity and abundance of fast-growing bacteria in the surface water of the northeast coast of Hainan Island in China, different cultivation methods were employed. This study also aims to provide a reference for isolating bacterial samples from seawater sources and preventing marine-derived pathogens. Methods: Based on the principles of taxonomic design, surface seawater samples were collected from six locations along the northeast coast of Hainan Island in China in March, June, October, and December 2021. Then, bacterial enrichment was performed based on traditional cultivation methods for Salmonella, Vibrio, Burkholderia pseudomallei, Actinomycetes, and general marine bacteria. After that, bacterial species identification was conducted by 16S rDNA amplicon sequencing and metagenomic sequencing. Results: A total of 1 151 fast-growing cultivable bacteria belonging to 66 genera and 213 species were identified using five different culture protocols. In different cultivation protocols, Bacillus and Klebsiella demonstrated extensive discriminatory advantages and ranked among the top genera in terms of abundance. Protocol 1 had Escherichia, Klebsiella, and Citrobacter as dominant genera. Pathogenic bacteria detected by protocol 1 included Klebsiella pneumoniae and Escherichia coli, with 37 and 29 strains respectively, while Salmonella enterica was uniquely detected with seven isolates. Proteus, Enterococcus, and Providencia were the dominant genera in protocol 2, and Proteus mirabilis was the most abundant pathogenic bacteria detected with 66 isolates. Vibrio cholerae was uniquely detected with six isolates at a higher abundance. Klebsiella, Escherichia, and Acinetobacter were the dominant genera in protocol 3, and Klebsiella pneumoniae was the most abundant pathogenic bacteria detected with 53 isolates, while Acinetobacter nosocomialis was uniquely detected with seven isolates. Vibrio and Pseudoalteromonas were the dominant genera in protocol 4, and they showed advantages in isolating and cultivating Marine-derived Vibrio. Exiguobacterium, Staphylococcus, and Bacillus were the dominant genera in protocol 5. Bacillus cereus and Lactococcus lactis were the most abundant pathogenic bacteria detected with 20 and 15 isolates, respectively, while Lactococcus lactis was uniquely detected at higher abundance. Metagenomic sequencing showed that Klebsiella pneumoniae was significantly dominant with a gene abundance of 51.11%, followed by Alcanivorax sp. at 12.57%. Conclusion: The surface water of the northeast coast of Hainan Island in China exhibits a rich diversity of bacteria, with Klebsiella pneumoniae being highly abundant in the studied area. Different cultivation methods demonstrate distinct selective advantages in culturing bacterial genera and pathogens. Therefore, it is necessary to optimize cultivation conditions for specific marine bacteria.

[Bioinformatics analysis and prokaryotic expression of Strongyloides stercoralis serine protease inhibitor 1].

OBJECTIVE: To predict the structure and antigenic epitope of the Strongyloides stercoralis serine protease inhibitor 1 (Ss-SRPN-1) protein using bioinformatics tools, and to construct prokaryotic expression plasmids for expression of recombinant Ss-SRPN-1 protein, so as to provide the basis for unraveling the function of the Ss-SRPN-1 protein. METHODS: The amino acid sequence of the Ss-SRPN-1 protein was downloaded from the NCBI database, and the physicochemical properties, structure and antigenic epitopes of the Ss-SRPN-1 protein were predicted using bioinformatics tools, including ExPASy, SWISS-MODEL and Protean. Primers were designed according to the nucleotide sequences of Ss-SRPN-1, and the Ss-SRPN-1 gene was amplified, cloned and sequenced with genomic DNA extracted from the infective third-stage larvae of S. stercoralis as a template. The Ss-SRPN-1 protein sequence was cloned into the pET28a (+) expression vector and transformed into Escherichia coli BL21 (DE) cells for induction of the recombinant Ss-SRPN-1 protein expression. The recombinant Ss-SRPN-1 protein was then purified and identified using Western blotting and mass spectrometry. RESULTS: Bioinformatics analysis showed that the Ss-SRPN-1 protein, which was composed of 372 amino acids and had a molecular formula of C1948H3046N488O575S16, was a stable hydrophilic protein, and the subcellular localization of the protein was predicted to be extracellular. The Ss-SRPN-1 protein was predicted to contain 11 dominant B-cell antigenic epitopes and 20 T-cell antigenic epitopes. The Ss-SRPN-1 gene with a length of 1 119 bp was successfully amplified, and the recombinant plasmid pET28a (+)/Ss-SRPN-1 was constructed and transformed into E. coli BL21(DE) cells. The expressed recombinant Ss-SRPN-1 protein had a molecular weight of approximately 43 kDa, and was characterized as a Ss-SRPN-1 protein. CONCLUSIONS: The recombinant Ss-SRPN-1 protein has been expressed successfully, and this recombinant protein may be a potential vaccine candidate against strongyloidiasis.

The influence of residual plural scattering after deconvolution in electron magnetic chiral dichroism.

This work investigated the existence and influence of residual plural scattering in electron magnetic chiral dichroism (EMCD) spectra. A series of low-loss, conventional core-loss, and q-resolved core-loss spectra at Fe-L2,3 edges were detected from areas of different thicknesses in a plane-view sample of Fe/MgO (001) thin film. It reveals by comparison that there remains noticeable plural scattering in q-resolved spectra acquired at two particular chiral positions after deconvolution, and the residual scattering is more significant in thicker areas than thinner ones. Accordingly, the orbital-to-spin moment ratio extracted from EMCD spectra, which is the difference between the two q-resolved spectra after deconvolution, would be in principle increased with increasing sample thickness. The randomly fluctuated moment ratios displayed in our experiments are greatly attributed to a slight and irregular variation of local diffraction conditions due to the bending effect and imperfect epitaxy in detected areas. We suggest EMCD spectra should be acquired from sufficiently thin samples to minimize the plural scattering effect in originally detected spectra before any deconvolution. In addition, great care should be taken for slight misorientation and imperfect epitaxy when performing EMCD investigation on epitaxial thin films using a nano beam.