Analysis of Magnetic Resonance Imaging Perfusion Parameters for the Identification of Spinal Metastatic Tumors with Rich Blood Supply.

PURPOSE: To determine the reliability of dynamic magnetic resonance imaging (MRI) perfusion parameters for the evaluation of blood supply to spinal metastatic tumors. METHODS: A total of 36 patients with spinal metastasis who underwent dynamic contrast-enhanced magnetic resonance spinal perfusion imaging at Tianjin Hospital from December 2018 to December 2020 were reviewed. Subsequently, the patients underwent corresponding preoperative examination using digital subtraction angiography of the spine at the hospital and were divided into 2 groups accordingly. Differences in dynamic MRI perfusion parameters between the 2 groups were analyzed. RESULTS: There were statistically significant differences between the 2 groups in the quantitative dynamic contrast-enhanced MRI perfusion parameters vascular permeability and plasma volume, as well as semi-quantitative peak enhancement and blood flow ratio parameters. CONCLUSIONS: Dynamic MRI perfusion may distinguish spinal metastatic lesions with rich blood supply from those with poor blood supply and may help clinicians identify patients that can benefit from invasive spinal angiography and preoperative embolization. This technique may also provide guidance on decision taking for surgery basing on dynamic MRI perfusion parameters.

[Effects of Different Aeration Treatments on Bacterial Diversity, Metabolic Activity, and Function in Constructed Wetlands].

Bacteria play a key role in the removal of pollutants and nutrients in constructed wetlands. DNA and RNA high-throughput sequencing was used to investigate the diversity, metabolic activity, and function of bacteria in aquaculture wastewater and in constructed wetlands treated by different aeration levels. The results revealed that:① a total of 4042 operational taxonomic units (OTUs) were detected in aquaculture wastewater and constructed wetland treatment groups. α-Proteobacteria, γ-Proteobacteria, and Bacteroidia were the most diverse groups, and the constructed wetlands aeration treatment increased the bacterial diversity to a variable extent; ② α-Proteobacteria, γ-Proteobacteria, Bacteroidia, and Actinobacteria were the dominant groups both in the DNA and RNA sequencing results, and the metabolic activities of these four groups were significantly affected by the concentration of total nitrogen (TN) and nitrate nitrogen (NO3--N) in our study. ③ According to the FAPROTAX database, 56 bacterial functional groups were detected in our study, mainly including:chemoheterotrophy, aerobic chemoheterotrophy, fermentation, intracellular parasites, dark hydrogen oxidation, phototrophy, photoheterotrophy, and nitrate reduction. Functions related to the nitrogen cycle were observed in the results of function annotation, suggesting the important role of bacterial communities in the removal of nitrogen nutrients in constructed wetlands. These results will improve the understanding of bacterial community structures and functions during nutrient removal in aerated constructed wetlands.

Development and validation of a novel risk assessment model to estimate the probability of pulmonary embolism in postoperative patients.

Pulmonary embolism (PE) is a leading cause of mortality in postoperative patients. Numerous PE prevention clinical practice guidelines are available but not consistently implemented. This study aimed to develop and validate a novel risk assessment model to assess the risk of PE in postoperative patients. Patients who underwent Grade IV surgery between September 2012 and January 2020 (n = 26,536) at the Affiliated Dongyang Hospital of Wenzhou Medical University were enrolled in our study. PE was confirmed by an identified filling defect in the pulmonary artery system in CT pulmonary angiography. The PE incidence was evaluated before discharge. All preoperative data containing clinical and laboratory variables were extracted for each participant. A novel risk assessment model (RAM) for PE was developed with multivariate regression analysis. The discrimination ability of the RAM was evaluated by the area under the receiver operating characteristic curve, and model calibration was assessed by the Hosmer-Lemeshow statistic. We included 53 clinical and laboratory variables in this study. Among them, 296 postoperative patients developed PE before discharge, and the incidence rate was 1.04%. The distribution of variables between the training group and the validation group was balanced. After using multivariate stepwise regression, only variable age (OR 1.070 [1.054-1.087], P < 0.001), drinking (OR 0.477 [0.304-0.749], P = 0.001), malignant tumor (OR 2.552 [1.745-3.731], P < 0.001), anticoagulant (OR 3.719 [2.281-6.062], P < 0.001), lymphocyte percentage (OR 2.773 [2.342-3.285], P < 0.001), neutrophil percentage (OR 10.703 [8.337-13.739], P < 0.001), red blood cell (OR 1.872 [1.384-2.532], P < 0.001), total bilirubin (OR 1.038 [1.012-1.064], P < 0.001), direct bilirubin (OR 0.850 [0.779-0.928], P < 0.001), prothrombin time (OR 0.768 [0.636-0.926], P < 0.001) and fibrinogen (OR 0.772 [0.651-0.915], P < 0.001) were selected and significantly associated with PE. The final model included four variables: neutrophil percentage, age, malignant tumor and lymphocyte percentage. The AUC of the model was 0.949 (95% CI 0.932-0.966). The risk prediction model still showed good calibration, with reasonable agreement between the observed and predicted PE outcomes in the validation set (AUC 0.958). The information on sensitivity, specificity and predictive values according to cutoff points of the score in the training set suggested a threshold of 0.012 as the optimal cutoff value to define high-risk individuals. We developed a new approach to select hazard factors for PE in postoperative patients. This tool provided a consistent, accurate, and effective method for risk assessment. This finding may help decision-makers weigh the risk of PE and appropriately select PE prevention strategies.

Characterization and role of PGK from Litopenaeus vannamei in WSSV infection.

Phosphoglycerate kinase (EC 2.7.2.3, PGK) catalyses the reversible transfer of a phosphate group from 1,3-diphosphoglyceric acid and ADP to produce 3-phosphoglyceric acid and ATP, which represents the initial production of ATP during glycolysis; therefore, PGK is a key enzyme in the energy metabolism. To study the role of PGK in the resistance to WSSV infection in shrimp, the full-length cDNA of the PGK gene (LvPGK) from Litopenaeus vannamei was obtained by using homology cloning and RACE amplification. The tissue distribution of LvPGK and its expression changes in the main immune tissues after WSSV stimulation were obtained by quantitative real-time PCR. Furthermore, RNA interference (RNAi) was used to study the role of LvPGK in shrimp defending against WSSV infection. The results showed that the full-length cDNA sequence of LvPGK was 1855 bp, contained a 1248 bp open reading frame (ORF) encoding 415 amino acids, and included a conserved PGK domain. LvPGK presented ubiquitous expression in most examined tissues, with the most predominant expression in the muscle and the weakest expression in the intestine. LvPGK transcripts could be induced in the hemocytes and hepatopancreas by injection with WSSV. Both the replication of WSSV and the shrimp cumulative mortality decreased significantly after LvPGK knockdown (P < 0.01). After challenging LvPGK RNAi shrimp with WSSV, the concentration of glucose in the hepatopancreas and muscle tissue did not show significant change; however, the content of pyruvate and lactate decreased significantly (P < 0.05). Moreover, significant decreases in the expression levels of crustin, ALF1, ALF2 and ALF3 were also detected. The results suggested that LvPGK might be involved in WSSV replication by increasing host aerobic and anaerobic metabolism.

Glycogen phosphorylase of shrimp (Litopenaeus vannamei): Structure, expression and anti-WSSV function.

Glycogen phosphorylase (GP, EC 2.4.1.1) catalyze the rate-limiting step in glycogenolysis in animals, forming glucose-1-phosphate from the terminal alpha-1,4-glycosidic bond. Therefore, GP plays a crucial role in carbohydrate metabolism. In the present study, the full-length cDNA sequence of GP (LvGP) was cloned from shrimp, Litopenaeus vannamei. The obtained 3242-bp LvGP cDNA sequence included a 5'-terminal untranslated region (UTR) of 48 bp, an open reading frame (ORF) of 2559 bp encoding a polypeptide of 852 amino acids (aa) and a 3'-UTR of 635 bp. The predicted LvGP protein sequence contained a typical phosphorylase domain (113-829 aa) and shared 72%-97% identities with GP from other species. Phylogenetic analysis revealed that LvGP showed the closest relationship with GP from Marsupenaeus japonicus. Tissue expression profiles showed that LvGP existed in most examined tissues, with the most predominant expression in the brain, followed by the muscles and stomach. LvGP transcripts in hepatopancreas and hemocytes were up regulated after the WSSV challenge. Furthermore, the role of LvGP in shrimp defending against WSSV infection was investigated by RNA interference (RNAi). Our findings showed that WSSV proliferation and shrimp accumulative mortality increased significantly after LvGP RNAi (P < 0.01). The glycogen, glucose, and pyruvate content decreased in GP RNAi shrimp after WSSV injection, however, the lactate and ATP concentration enhanced. Moreover, lectin and anti-lipopolysaccharide factor2 (ALF2) were induced in LvGP silencing shrimp after WSSV infection, whereas the expression levels of crustin, ALF1 and ALF3 decreased. Our results suggested that the LvGP might play a crucial role in shrimp defending against WSSV infection by regulating metabolism and affecting the anti-infectious gene expression.

Nematicidal amide alkaloids from the seeds of Clausena lansium.

Five new amide alkaloids (1-3, 5-6) were isolated from the seeds of Clausena lansium together with one new natural product (4) and four known analogues (7-10). The structures of the new amide alkaloids were elucidated based on a comprehensive spectroscopic data analysis including 1D and 2D NMR as well as HRESIMS, and by comparison with the literature. The bioactivity results showed that compound 8 expressed potent nematicidal activity against Panagrellus redivevus, with IC50 value of 0.12 mM, while compounds 3 and 5 presented moderate nematicidal activity with IC50 values of 2.75 and 3.93 mM, respectively (abamectin as the positive control with IC50 value of 1.05 mM).

A retrospective study of female reproductive parameters in the Kunming dog.

The Kunming dog is the first and only working dog breed from China to be recognized worldwide. As a domestic working dog, its excellent working performance has been well established; however, its normal reproductive parameters are not well understood. Therefore, this study was conducted to document the main reproductive parameters of this purebred working dog in field breeding conditions. Data on 1004 heats (753 with mating) from 203 bitches between 2008 to 2014, were collected and analyzed. The pregnancy rate and whelping rate was 79.42% and 75.30%, respectively. Finally, for 567 litters (4298 puppies), the mean litter size was 7.19 ± 0.12 puppies (range 1-15). The mean gestation period and birth weight were approximately 61.64 ± 0.10 days and 407.25 ± 1.21 g. The mean sex ratio was 1.03 males to 1.00 female. Estrus occurred throughout the year with no significant differences between seasons and months (P > 0.05), which confirms that Kunming dogs are non-seasonal breeders; births occurred in every month of the year. Pregnant bitches exhibited significantly longer inter-estrus intervals than non-pregnant bitches (220.85 ± 2.05 vs. 180.19 ± 2.94 days, P < 0.05). Bitch parity influenced litter size, and the gestation length and birth weight of the puppies were negatively affected by litter size. This study helps elucidate the reproductive potential of this breed and provides reference values for reproductive performance in the Kunming dog.

Three new flavanoids from artificially induced dragon's blood of Dracaena cambodiana.

Three new flavanoids, (2R)-7,4'-dihydroxy-8-methylflavan (1), (2R)-7,4'-dihydroxy-6-methylflavan (2), and (3R)-7,3',4'-trihydroxyhomoisoflavan (3), together with seven known compounds (4-10), were isolated from artificially induced dragon's blood of Dracaena cambodiana, and their structures were determined based on HR-ESI-MS and extensive spectroscopic techniques (UV, IR, 1D-, and 2D-NMR). Compound 2 exhibited weak cytotoxicity against BEL-7402 cells line with the IC50 value of 39.2 µM. In addition, compound 3 showed significant acetylcholinesterase (AChE) inhibitory activity.

Flavonoids from artificially induced dragon's blood of Dracaena cambodiana.

Dragon's blood is a rare traditional medicine used in many countries. Because of its various therapeutic uses, its requirement is increasing dramatically, while formation of dragon's blood need at least several years, so many researchers tried to induce the formation of dragon's blood artificially, but the chemical constituents of artificially induced dragon's blood were rarely studied. In our research, twenty constituents, including three new ones, were isolated from artificially induced dragon's blood of Dracaena cambodiana, five of which are the same with those from natural dragon's blood. In addition, six compounds exhibited cytotoxic activities, and eleven compounds demonstrated antibacterial activities. Artificially induced dragon's blood is expected to be the substituent of natural dragon's blood.

Birth of puppies of predetermined sex after artificial insemination with a low number of sex-sorted, frozen-thawed spermatozoa in field conditions.

The aim of this study was to evaluate fertility and sex ratios after artificial insemination in dogs under field conditions. Semen was cryopreserved as unsorted (control) or was separated into X- and Y-chromosome-bearing sperm using a cell sorter. Sixty female dogs were inseminated with frozen-thawed spermatozoa of 100 × 106 unsorted (a dose in practice) and 4 × 106 sorted (X and Y group, respectively). A total of 20 dogs became pregnant and 126 puppies were born from the three groups. The percentage of parturition was similar for the X (5/20; 25.0%) and Y (4/20; 20.0%) group (P > 0.05), but lower than controls (11/20; 55.0%) (P < 0.05). Ultimately 28 out of the 32 puppies produced from X group were female (87.5%) and 19/22 (86.4%) puppies of Y group were male. In contrast, sex ratio (51.4% to 48.6%) in the control was significantly different from the X, Y group (P < 0.05). However, male and female puppies in the control had similar birth weights and weaning weights to those from the X and Y groups. This preliminary information indicated that normal puppies of predicted sex can be produced with low numbers of sorted cryopreserved dog spermatozoa at a farm level, making sperm-sexing technology potentially applicable for elite breeding units.