Genetically modified pigs with CD163 point mutation are resistant to HP-PRRSV infection.

Porcine reproductive and respiratory syndrome (PRRS) is a globally prevalent contagious disease caused by the positive-strand RNA PRRS virus (PRRSV), resulting in substantial economic losses in the swine industry. Modifying the CD163 SRCR5 domain, either through deletion or substitution, can eff1ectively confer resistance to PRRSV infection in pigs. However, large fragment modifications in pigs inevitably raise concerns about potential adverse effects on growth performance. Reducing the impact of genetic modifications on normal physiological functions is a promising direction for developing PRRSV-resistant pigs. In the current study, we identified a specific functional amino acid in CD163 that influences PRRSV proliferation. Viral infection experiments conducted on Marc145 and PK-15 CD163 cells illustrated that the mE535G or corresponding pE529G mutations markedly inhibited highly pathogenic PRRSV (HP-PRRSV) proliferation by preventing viral binding and entry. Furthermore, individual viral challenge tests revealed that pigs with the E529G mutation had viral loads two orders of magnitude lower than wild-type (WT) pigs, confirming effective resistance to HP-PRRSV. Examination of the physiological indicators and scavenger function of CD163 verified no significant differences between the WT and E529G pigs. These findings suggest that E529G pigs can be used for breeding PRRSV-resistant pigs, providing novel insights into controlling future PRRSV outbreaks.

Effects of melatonin on testicular function in adult male mice under different photoperiods.

Photoperiod is an important environmental factor affecting animal physiological function. Melatonin is an endogenous hormone that plays an important role in circadian and seasonal (or cyclical) rhythms and seasonal reproduction in mammals. To investigate the effects of melatonin on the reproductive performance of adult male mice under different photoperiods, sixty mice were randomly allotted to six groups: control (Light Dark, 12 L:12 D), control plus melatonin (MLD, 12 L:12 D), 24-hour continuous light (LL, 24 L:0 D), 24-hour continuous light plus melatonin (MLL 24 L:0 D), constant darkness (DD, 0 L:24 D), and constant darkness plus melatonin (MDD, 0 L:24 D). Normal saline (100 µL) was injected into the LD, LL, and DD groups at noon each day; the MLD, MLL, and MDD groups were injected with melatonin (1 mg/mL; 2 mg/kg·body weigh). After 24 hours of prolonged light exposure, testis morphology decreased, convoluted seminiferous tubules became sparse, the diameter of convoluted seminiferous tubules decreased, and the level of sex hormones decreased. After the administration of exogenous melatonin, testicular morphology and sex hormone levels decreased in the MLD group under normal light conditions. In the MLL group, the testicular tissue morphology returned to normal, the diameter of convoluted tubules increased, the hormone levels of LH (Luteinizing hormone) and MTL (melatonin) significantly increased (P<0.05), and th0e gene expressions of LHß and Mtnr1A (Melatonin receptors 1A) increased. There was almost no difference in the MDD group under continuous darkness. In conclusion, melatonin can damage the reproductive performance of male mice under normal light conditions, while exogenous melatonin can alleviate and protect the testicular injury of male mice under continuous light conditions.

Peptide-Tethered Hydrogel Scaffold Promotes Recovery from Spinal Cord Transection via Synergism with Mesenchymal Stem Cells.

Spinal cord injury (SCI) is one of the most devastating injuries. Treatment strategies for SCI are required to overcome comprehensive issues. Implantation of biomaterial scaffolds and stem cells has been demonstrated to be a promising strategy. However, a comprehensive recovery effect is difficult to achieve. In the comprehensive treatment process, the specific roles of the implanted scaffolds and of stem cells in combined strategy are usually neglected. In this study, a peptide-modified scaffold is developed based on hyaluronic acid and an adhesive peptide PPFLMLLKGSTR. Synchrotron radiation micro computed tomography measurement provides insights to the three-dimensional inner topographical property and perspective porous structure of the scaffold. The modified scaffold significantly improves cellular survival and adhesive growth of mesenchymal stem cells during 3D culture in vitro. After implantation in transected spinal cord, the modified scaffold and mesenchymal stems are found to function in synergy to restore injured spinal cord tissue, with respective strengths. Hindlimb motor function scores exhibit the most significant impact of the composite implant at 2 weeks post injury, which is the time secondary injury factors begin to take hold. Investigation on the secondary injury factors including inflammatory response and astrocyte overactivity at 10 days post injury reveals the possible underlying reason. Implants of the scaffold, cells, and especially the combination of both elicit inhibitory effects on these adverse factors. The study develops a promising implant for spinal cord tissue engineering and reveals the roles of the scaffold and stem cells. More importantly, the results provide the first understanding of the bioactive peptide PPFLMLLKGSTR concerning its functions on mesenchymal stem cells and spinal cord tissue restoration.

[Clinical effect of triple therapy combined with Saccharomyces boulardii in the treatment of Helicobacter pylori infection in children].

OBJECTIVE: To evaluate the clinical effect of proton pump inhibitor-based triple therapy combined with Saccharomyces boulardii in the treatment of Helicobacter pylori (Hp) infection among children in terms of Hp eradication rate and incidence of adverse events. METHODS: A prospective randomised controlled study was conducted on 240 children with a confirmed diagnosis of Hp infection. These patients were randomized into triple therapy (n=120) and probiotics groups (n=120). The triple therapy group received amoxicillin [40 mg/(kg·d), Tid], clarithromycin [15 mg/(kg·d), Bid] and omeprazole [0.7-0.8 mg/(kg·d), Qd], while the probiotics group received Saccharomyces boulardii (250 mg, Bid) in addition to triple therapy. The course of treatment was 14 days in both groups. The adverse events in subjects were recorded by their parents during treatment. Hp eradiation was evaluated by (13)C breath test at 4 weeks after treatment, and the eradication rate and incidence of adverse events were compared between the two groups. RESULTS: The Hp eradication rates were 75.8% (91/120) in the triple therapy group and 85% (102/120) in the probiotics group (P>0.05). Compared with the triple therapy group, the probiotics group had nonsignificantly lower incidence of nausea, vomiting, and abdominal pain (P>0.05) and significantly lower incidence of stomatitis, constipation and diarrhea (P<0.05). CONCLUSIONS: Triple therapy combined with Saccharomyces boulardii cannot significantly increase Hp eradication rate, but can significantly reduce the incidence of stomatitis, constipation, and diarrhea during treatment.

[Clinical application of single-balloon enteroscopy in children with small intestinal bleeding].

OBJECTIVE: To investigate the diagnostic value and safety of single-balloon electronic enteroscopy in children with small intestinal bleeding. METHODS: Seventy children with clinically suspected small intestinal bleeding, including 38 males and 32 females aged 4-13 years, underwent single-balloon enteroscopy under general anesthesia. Twenty-six cases underwent the procedure through the mouth, 32 cases through the anus, and 12 cases through both. RESULTS: Of the 70 children, 58 (83%) had small bowel disease according to the single-balloon enteroscopy results, including 24 cases of non-specific inflammation, 12 cases of allergic purpura, 8 cases of Crohn's disease, 8 cases of Meckel's diverticulum, and 6 cases of Peutz-Jeghers syndrome. CONCLUSIONS: Single-balloon enteroscopy is a safe, effective means for the diagnosis of small intestinal bleeding among children.

Using ion-pair reversed-phase HPLC ICP-MS to simultaneously determine Cr(III) and Cr(VI) in urine of chromate workers.

Urinary chromium speciation analysis can provide available information of the individual exposure levels of Cr(VI) compounds. An analytical method based on ion-pair reversed-phase HPLC combined with ICP-MS to simultaneously determine Cr(III) and Cr(VI) in human urine has been developed for assessing the occupational exposure to chromate. The separation conditions of the method, including the pH value, the concentrations of ion-pair reagent and methanol in the mobile phase were studied. Specially, a high-speed polyetheretherketone (PEEK) column and a typical sample introduction method were employed to avoid the exogenous chromium contamination during the analysis. The separation of Cr(III) and Cr(VI) could be finished within 4min with the detection limits as low as 0.03microgL(-1) at 100microL injections for both of them, providing a convenient method for routine analysis of chromium species. The chromium species in urine of chromate workers were monitored using the developed method. The statistical analysis showed a significant relationship (n=32, p<0.01) between the urinary Cr(VI) and the individual airborne exposure levels, indicating that the urinary Cr(VI) could be used as a convenient and suitable monitor for high level Cr(VI) occupational exposure.

[Rapid molecular diagnosis of trisomy 21 using the PCR-STR-SSCP technique].

OBJECTIVE: Developing a PCR-based method to diagnose trisomy 21 directly by alternative detection of the SSCP profiles of the STR fragments amplified. METHODS: The DNA samples from 19 trisomy 21 patients, 3 at-risk fetuses of trisomy 21 and a total of 44 samples from their parents as controls were drawn for this study, in which the trisomy 21 was determined by G-band karytyping. Two polymorphic STR at D21S11 and D21S1411 served as the gene markers, and two separate PCR-amplified primers were designed.The STR-amplicons denatured were subjected to polyacrylamide gel electrophoresis for SSCP analysis. RESULTS: This assay can identify three STR fragments representing parents' chromosome 21 by detecting the electrophoresis separation profiles of PCR-amplified fragments. With the use of this assay, the authors analyzed the 22 cases of trisomy 21;accurate diagnoses were made except for one case in which the electrophoresis pattern at D21S11 site could not present the diagnostic information because of the homozygous state of this family. The 3 at-risk fetuses were found to be the trisomy 21 patients, followed by confirmation of the results by G-band karytyping of aborted samples. CONCLUSION: The present PCR-STR-SSCP assay can be applied as a simple, rapid and accurate method in the prenatal diagnosis and genetic screening of trisomy 21.