Objective:To explore the clinical treatment principles for tibial plateau fracture related infection (TPFRI).Methods:A retrospective study was used to analyze the clinical data of 47 patients with TPFRI who had been admitted to The Third Hospital of Hebei Medical University from May 2015 to May 2022. There were 33 males and 14 females, with an age of (49.3±9.5) years. By admission, 32 tibial plateau fractures got healed while 15 ones remained unhealed. According to the site of infection, TPFRI was classified into 3 categories: arthritic type (9 cases), adjacent articular type (28 cases), and distal articular type (10 cases). Individualized reconstruction plans were made according to fracture union, bone and soft tissue defects, and infection involvement of the knee joint. The knee function was assessed by the modified Hospital for Special Surgery (HSS) criteria at the final follow-up. The fracture union and complications were recorded.Results:All patients were followed up for (37.4±11.7) months. The infection was controlled and the fractures got united after (4.6±1.4) months in the 15 patients whose tibial plateau fractures remained unhealed by admission. In the 32 cases whose tibial plateau fractures got healed by admission (except for the 7 cases without bone defects, 1 case undergoing femoral condyle amputation and 1 case undergoing tibial flip amputation), respectively, Masquelet technique was used in 5 cases, Ilizarov bone transport in 3 cases, filling with an astrocnemius muscle flap or a myocutaneous flap in 5 cases, semi-open bone grafting in 1 case, open bone cement rod technique in 1 case, platelet-rich plasma combined with negative pressure drainage in 1 case, and knee arthrodesis in 7 cases to reconstruct their bone and soft tissue defects. At the final follow-up, the knee function was evaluated based on the modified HSS scoring as excellent in 28 cases, as good in 15 cases, as moderate in 3 cases and as poor in 1 case. The number of the patients with excellent or good knee function was significantly larger in the adjacent articular type and distal articular type than in the arthritic type ( P<0.05). The number of the patients with excellent or good knee function was significantly larger in those whose tibial plateau fractures remained unhealed by admission than in those whose tibial plateau fractures got healed by admission ( P<0.05). All patients did not experience such complications as open fat liquefaction, bone nonunion, lower limb deep vein thrombosis, or pulmonary embolism. Conclusions:In the treatment of TPFRI, individualized treatment plans should be made to improve infection control, accelerate functional recovery of the knee joint, and reduce incidence of complications, taking into consideration such factors as fracture union, bone and soft tissue defects, and infection involvement of the knee joint.

Objective To explore the polymorphism of tyrosinase (TYR) and melanocortin 1 receptor (MC1R) genes and their mRNA expression levels in relation to coat-color phenotypes in guinea pigs, providing genetic markers for locating dominant traits in guinea pigs. Methods A total of 57 self-bred ordinary-level guinea pigs were selected and divided into three groups based on coat color: white (n=22), variegated (n=22) and black (n=13). The guinea pigs were euthanized with an overdose of pentobarbital sodium via intraperitoneal injection. DNA was then extracted from the dorsal skin tissue. Polymorphism in the coding sequence (CDS) of the exons of the TYR and MC1R genes in each group was detected by cloning and sequencing. The mRNA expression of the two genes in skin tissues was detected by real-time fluorescent quantitative PCR to investigate the relationship between these genes and guinea pig coat color. Results A single nucleotide polymorphism (SNP) site was found in the CDS region of TYR exon Ⅰ, where the base A was replaced by G. All white guinea pigs had the G/G genotype for TYR, while no deep-colored (variegated and black) guinea pigs exhibited the G/G genotype for TYR. Most deep-colored guinea pigs had the A/A genotype, and a few had A/G genotype. The A/A genotype frequency in black guinea pigs was higher than in variegated guinea pigs. A 2 760 bp sequence deletion was identified in the exon of the MC1R gene, marked as the - gene, with non-deleted samples marked as N gene. Most white guinea pigs had the -/- genotype for MC1R, variegated guinea pigs mainly had the -/N genotype, and black guinea pigs mainly had the N/N genotype, with a few showing the -/N. The TYR gene expression level was higher in white guinea pigs, lower in variegated guinea pigs, and intermediate in black guinea pigs, but there was no significant difference among the three groups (P>0.05). The MC1R gene expression level in white guinea pigs was extremely low, while both variegated and black guinea pigs showed significantly higher levels than white guinea pigs (P<0.01). Black guinea pigs showed significantly higher levels than variegated guinea pigs (P<0.05). ConclusionThe TYR and MC1R genes synergistically regulate coat color of guinea pigs. The G-site mutation in the TYR gene may lead to albinism, and the change of N-site in the MC1R gene affects the depth of the coat color.

Objective:To explore the clinical treatment principles for tibial plateau fracture related infection (TPFRI).Methods:A retrospective study was used to analyze the clinical data of 47 patients with TPFRI who had been admitted to The Third Hospital of Hebei Medical University from May 2015 to May 2022. There were 33 males and 14 females, with an age of (49.3±9.5) years. By admission, 32 tibial plateau fractures got healed while 15 ones remained unhealed. According to the site of infection, TPFRI was classified into 3 categories: arthritic type (9 cases), adjacent articular type (28 cases), and distal articular type (10 cases). Individualized reconstruction plans were made according to fracture union, bone and soft tissue defects, and infection involvement of the knee joint. The knee function was assessed by the modified Hospital for Special Surgery (HSS) criteria at the final follow-up. The fracture union and complications were recorded.Results:All patients were followed up for (37.4±11.7) months. The infection was controlled and the fractures got united after (4.6±1.4) months in the 15 patients whose tibial plateau fractures remained unhealed by admission. In the 32 cases whose tibial plateau fractures got healed by admission (except for the 7 cases without bone defects, 1 case undergoing femoral condyle amputation and 1 case undergoing tibial flip amputation), respectively, Masquelet technique was used in 5 cases, Ilizarov bone transport in 3 cases, filling with an astrocnemius muscle flap or a myocutaneous flap in 5 cases, semi-open bone grafting in 1 case, open bone cement rod technique in 1 case, platelet-rich plasma combined with negative pressure drainage in 1 case, and knee arthrodesis in 7 cases to reconstruct their bone and soft tissue defects. At the final follow-up, the knee function was evaluated based on the modified HSS scoring as excellent in 28 cases, as good in 15 cases, as moderate in 3 cases and as poor in 1 case. The number of the patients with excellent or good knee function was significantly larger in the adjacent articular type and distal articular type than in the arthritic type ( P<0.05). The number of the patients with excellent or good knee function was significantly larger in those whose tibial plateau fractures remained unhealed by admission than in those whose tibial plateau fractures got healed by admission ( P<0.05). All patients did not experience such complications as open fat liquefaction, bone nonunion, lower limb deep vein thrombosis, or pulmonary embolism. Conclusions:In the treatment of TPFRI, individualized treatment plans should be made to improve infection control, accelerate functional recovery of the knee joint, and reduce incidence of complications, taking into consideration such factors as fracture union, bone and soft tissue defects, and infection involvement of the knee joint.

Objective To investigate the contamination status of cloth mouse pads in dental clinics,and provide theoretical basis for standardizing environmental surface disinfection and scientific intervention in dental clinics.Methods The contamination status of cloth mouse pads in 5 dental clinics were investigated by adenosine triphos-phate(ATP)fluorescence detection method,visual observation method,and bacterial culture method.Disinfection efficacy of ultraviolet disinfection method and wiping disinfection using two types of disinfectant wipes on cloth mouse pads and photovoltaic glass mouse pads was compared.Intervention measures(using photovoltaic glass mouse pads,regular cleaning and disinfecting)were taken,and contamination status of cloth mouse pads in different departments before and after intervention was compared.Results The baseline investigation found that the conta-mination status of mouse pads varied in different dental clinics.The qualified rate of bacterial culture of mouse pads in department of endodontics was the lowest(20.00％),followed by the department of periodontology(30.00％).There was statistically significant difference in ATP detection values between two types of disinfectant wipes before and after wiping and disinfecting photovoltaic glass mouse pads(both P＜0.001).After using photovoltaic glass mouse pads,the contamination of mouse pads in 5 dental clinics was alleviated,and the qualified rate of ATP detec-tion increased(＞80％),compared with qualified rate of ATP detection before intervention,differences were all sta-tistically significant(all P＜0.001).Conclusion The contamination of the cloth mouse pads in dental clinics is seri-ous,and the conventional cloth mouse pad is difficult to be cleaned and disinfected.It is suggested that medical in-stitutions use the mouse pad which is convenient for cleaning and disinfection,and specify the disinfection method and frequency to control the contamination of the mouse pads.

Objective To investigate the contamination status of cloth mouse pads in dental clinics,and provide theoretical basis for standardizing environmental surface disinfection and scientific intervention in dental clinics.Methods The contamination status of cloth mouse pads in 5 dental clinics were investigated by adenosine triphos-phate(ATP)fluorescence detection method,visual observation method,and bacterial culture method.Disinfection efficacy of ultraviolet disinfection method and wiping disinfection using two types of disinfectant wipes on cloth mouse pads and photovoltaic glass mouse pads was compared.Intervention measures(using photovoltaic glass mouse pads,regular cleaning and disinfecting)were taken,and contamination status of cloth mouse pads in different departments before and after intervention was compared.Results The baseline investigation found that the conta-mination status of mouse pads varied in different dental clinics.The qualified rate of bacterial culture of mouse pads in department of endodontics was the lowest(20.00％),followed by the department of periodontology(30.00％).There was statistically significant difference in ATP detection values between two types of disinfectant wipes before and after wiping and disinfecting photovoltaic glass mouse pads(both P＜0.001).After using photovoltaic glass mouse pads,the contamination of mouse pads in 5 dental clinics was alleviated,and the qualified rate of ATP detec-tion increased(＞80％),compared with qualified rate of ATP detection before intervention,differences were all sta-tistically significant(all P＜0.001).Conclusion The contamination of the cloth mouse pads in dental clinics is seri-ous,and the conventional cloth mouse pad is difficult to be cleaned and disinfected.It is suggested that medical in-stitutions use the mouse pad which is convenient for cleaning and disinfection,and specify the disinfection method and frequency to control the contamination of the mouse pads.

BACKGROUND:The traditional fixation method for femoral neck fractures is three hollow screws inverted triangle fixation,and the optimal fixation method for femoral neck fractures that have not achieved anatomical reduction is inconclusive. OBJECTIVE:To compare the biomechanical properties of cannulated screws internal fixation for sub-capitated femoral neck fracture with different reduction qualities based on finite element analysis. METHODS:The three-dimensional digital model was reconstructed using CT data of the proximal femur from a healthy male volunteer.The femur was modeled to sub-capitated femoral neck fractures.Fracture models were divided into anatomical reduction group,coxa vara group,and coxa valgus group.All fracture model groups were transferred using the standard group,screw depression group,and screw elevation group.A vertical downward stress of 1 400 N was applied to the femoral head at the top of the acetabulum.The displacement and stress distribution of the femur and internal fixator under different fixation methods were observed,and the maximum stress and displacement of the femur and fixator were compared. RESULTS AND CONCLUSION:(1)For anatomical reduction femoral neck fracture,the peak stress of fixation in the standard group,screw depression group and screw elevation group was 41.35,31.27 and 43.32 MPa,respectively.The maximum peak stress of the femur was found on the screw elevation group(28.58 MPa),and the standard group had the maximum peak displacement.(2)During hip varus,the stresses in the three subgroups were relatively dispersed and even.The peak stress of the femur in the standard group was the smallest,but the peak displacement was the largest.The stability of fixation might be poor.The peak displacement of the femur in the screw depression group was the smallest.(3)In the hip valgus,obvious screw stress concentration appeared in the screw depression group,and the peak displacement was the largest among the three subgroups,and an in-out-in phenomenon appeared.The peak stress of the screws in the screw elevation group was the largest among the three subgroups,but the peak displacement was the smallest.(4)It is concluded that for sub-capitated femoral neck fractures that are completely anatomically reduced,it is recommended to use standard inverted triangular nails for fixation.When the hip varus and hip valgus occur within the allowable range of the reduction standard,it is recommended to use the inverted triangle screw to fix it by rotating the corresponding angle in the same direction as the hip varus or valgus.

During the gene editing process mediated by CRISPR/Cas9, precise genome editing and gene knock-in can be achieved by the homologous recombination of double-stranded DNA (dsDNA) donor template. However, the low-efficiency of homologous recombination in eukaryotic cells hampers the development and application of this gene editing strategy. Here, we developed a novel CRISPR/Cas9-hLacI donor adapting system (DAS) to enhance the dsDNA-templated gene editing, taking the advantage of the specific binding of the LacI repressor protein and the LacO operator sequence derived for the Escherichia coli lactose operon. The codon-humanized LacI gene was fused as an adaptor to the Streptococcus pyogenes Cas9 (SpCas9) and Staphylococcus lugdunensis Cas9 (SlugCas9-HF) genes, and the LacO operator sequence was used as the aptamer and linked to the dsDNA donor template by PCR. The Cas9 nuclease activity after the fusion and the homology-directed repair (HDR) efficiency of the LacO-linked dsDNA template were firstly examined using surrogate reporter assays with the corresponding reporter vectors. The CRISPR/Cas9-hLacI DASs mediated genome precise editing were further checked, and we achieved a high efficiency up to 30.5% of precise editing at the VEGFA locus in HEK293T cells by using the CRISPR/SlugCas9-hLacI DAS. In summary, we developed a novel CRISPR/Cas9-hLacI DAS for dsDNA-templated gene editing, which enriches the CRISPR/Cas9-derived gene editing techniques and provides a novel tool for animal molecular design breeding researches.
Humans ; Animals ; Gene Editing ; CRISPR-Cas Systems/genetics* ; HEK293 Cells ; Homologous Recombination ; DNA

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare autosomal recessive hereditary mitochondrial disease, which is mainly characterized by gastrointestinal and neurological system involvement. This article reports a rare case of MNGIE which presented as chronic diarrhea. The purpose is to improve the understanding of MNGIE.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare autosomal recessive hereditary mitochondrial disease, which is mainly characterized by gastrointestinal and neurological system involvement. This article reports a rare case of MNGIE which presented as chronic diarrhea. The purpose is to improve the understanding of MNGIE.