Clinical observation of extraction-site incisional hernia after laparoscopic colorectal surgery.

BACKGROUND: Laparoscopic colorectal cancer surgery increases the risk of incisional hernia (IH) at the tumor extraction site. AIM: To investigate the incidence of IH at extraction sites following laparoscopic colorectal cancer surgery and identify the risk factors for IH incidence. METHODS: This study retrospectively analyzed the data of 1614 patients who underwent laparoscopic radical colorectal cancer surgery with tumor extraction through the abdominal wall at our center between January 2017 and December 2022. Differences in the incidence of postoperative IH at different extraction sites and the risk factors for IH incidence were investigated. RESULTS: Among the 1614 patients who underwent laparoscopic radical colorectal cancer surgery, 303 (18.8%), 923 (57.2%), 171 (10.6%), and 217 (13.4%) tumors were extracted through supraumbilical midline, infraumbilical midline, umbilical, and off-midline incisions. Of these, 52 patients developed IH in the abdominal wall, with an incidence of 3.2%. The incidence of postoperative IH was significantly higher in the off-midline incision group (8.8%) than in the middle incision groups [the supraumbilical midline (2.6%), infraumbilical midline (2.2%), and umbilical incision (2.9%) groups] (χ2 = 24.985; P < 0.05). Univariate analysis showed that IH occurrence was associated with age, obesity, sex, chronic cough, incision infection, and combined diabetes, anemia, and hypoproteinemia (P < 0.05). Similarly, multivariate analysis showed that off-midline incision, age, sex (female), obesity, incision infection, combined chronic cough, and hypoproteinemia were independent risk factors for IH at the site of laparoscopic colorectal cancer surgery (P < 0.05). CONCLUSION: The incidence of postoperative IH differs between extraction sites for laparoscopic colorectal cancer surgery. The infraumbilical midline incision is associated with a lower hernia rate and is thus a suitable tumor extraction site.

Study on energy evolution and fractal characteristics of sandstone with different fracture dip angles under uniaxial compression.

In order to investigate the failure modes and instability mechanism of fractured rock. Uniaxial compression tests were conducted on sandstone specimens with different dip angles. Based on rock energy dissipation theory and fractal theory, the energy evolution characteristics and fragmentation fractal characteristics in the process of deformation and failure of specimens were analyzed. The results show that the peak strength and elastic modulus of fractured rock mass are lower than those of intact samples, and both show an exponential increase with the increase of fracture dip angle. The energy evolution laws of different fracture specimens are roughly similar and can be classified into four stages based on the stress-strain curve: pressure-tight, elastic, plastic, and post-destructive. The total strain energy, elastic strain energy, and dissipated strain energy of the specimen at the peak stress point increased exponentially with crack inclination, and the dissipated strain energy and compressive strength conformed to a power function growth relationship. The distribution of the fragments after the failure of the fracture sample has fractal characteristics, and the fractal dimension increases with the increase of the fracture dip angle. In addition, the higher the compressive strength of the specimen, the greater the energy dissipation, the more serious the degree of fragmentation, and the greater the fractal dimension. The data fitting further shows that there is a power function relationship between the dissipated strain energy and the fractal dimension. The research results can provide a theoretical basis for the stability of rock mass engineering and structural deformation control.

Novel MIP gene mutation causes autosomal-dominant congenital cataract.

AIM: To identify disease-causative mutations in families with congenital cataract. METHODS: Two Chinese families with autosomal-dominant congenital cataract (ADCC) were recruited and underwent comprehensive eye examinations. Gene panel next-generation sequencing of common pathogenic genes of congenital cataract was performed in the proband of each family. Sanger sequencing was used to valid the candidate gene mutations and sequence the other family members for co-segregation analysis. The effect of sequence changes on protein structure and function was predicted through bioinformatics analysis. Major intrinsic protein (MIP)-wildtype and MIP-G29R plasmids were constructed and microinjected into zebrafish single-cell stage embryos. Zebrafish embryonic lens phenotypes were screened using confocal microscopy. RESULTS: A novel heterozygous mutation (c.85G>A; p.G29R) in the MIP gene was identified in the proband of one family. A known heterozygous mutation (c.97C>T; p.R33C; rs864309693) in MIP was found in the proband of another family. In-silico prediction indicated that the novel mutation might affect the MIP protein function. Zebrafish embryonic lens was uniformly transparent in both wild-type PCS2+MIP and mutant PCS2+MIP. CONCLUSION: Two missense mutations in the MIP gene in Chinese cataract families are identified, and one of which is novel. These findings expand the genetic spectrum of MIP mutations associated with cataracts. The functional studies suggest that the novel MIP mutation might not be a gain-of-function but a loss-of-function mutation.