Objective To explore the the detection of MMP-2,-7,-9,and-12 enzymatic activity using the CEACAM1-derived fluorescent peptide substrate Site 84,investigating the application of substrate Site 84 to distinguishing between MMP-2 and MMP-9 in the gelatinase spectrum of MMPs.Methods The fluorescent enzymatic method was employed to observe the detection of MMP-2,-7,-9,and-12 enzymatic activity using substrate Site 84;further observations were made on the sensitivity and specificity of substrate Site 84 to enzymatic activity of MMP-2 and MMP-9 within the gelatinase spectrum;the kinetic parameters(Km and Kcat)of the enzymatic reaction between substrate Site 84 and MMP-2 were obtained.Results Using Site 84 as a substrate,enzymic kinetics curves for MMP-12,-7,-2 were obtained,but no enzymatic activity curve for MMP-9 was observed.Furthermore,Site 84 specifically detected the enzymatic activity of MMP-2 within the gelatinase spectrum,capable of detecting low concentration(0.6 μM)of MMP-2 enzymatic activity,but no obvious enzymatic reaction was observed for high concentration(6 μM)of MMP-9;the kinetics parameters for the enzymatic reaction between Site 84 and MMP-2 were Km=315 μM,Kcat/Km=2 565/MS.Conclusion The CEACAM1-derived substrate Site 84 serves as a novel fluorescent peptide substrate,enabling the acquisition of enzymatic activity curves for MMP-12,-7 and-2,and specifically detecting the enzymatic activity of MMP-2 within the MMP gelatinase spectrum.

Objective:To observe any effect of bilateral high-frequency repetitive transcranial magnetic stimulation (rTMS) of the cerebellum on the swallowing of stroke survivors with dysphagia.Methods:Thirty-eight patients with post-stroke dysphagia were randomly divided into a cerebellar stimulation group of 20 and a sham group of 18. In addition to drug therapy and physical rehabilitation training, the cerebellar stimulation group received 500 pulses of rTMS of the cerebellum daily at 10Hz and 120% of the resting movement threshold lasting 1s at 9s intervals. The sham stimulation group was treated with sham rTMS (with the angle between the stimulation coil and the scalp at 90°). Twenty minutes later, both groups were given 30 minutes of routine swallowing training daily by the same speech therapist. The treatment was administered 5 times a week for 3 weeks. Before the treatment and afterward, both groups′ swallowing was evaluated y videofluoroscopic swallowing study (VFSS), using a functional dysphagia scale (FDS) and using the Rosenbek penetration aspiration scale (PAS). Oral transport time, swallowing response time, pharyngeal transport time, laryngeal vestibular closure time and upper esophageal sphincter opening duration were recorded, and the changes in swallowing function and swallowing time parameters before and after the treatment were compared between the two groups.Results:Before the stimulation there were no significant differences between the two groups. Afterward, the average PAS and FDS scores of both groups had improved significantly, but with significantly greater improvement in the cerebellar stimulation group than in the sham group. Average oral transit time and swallow response time had shortened significantly, but with significantly shorter time, on average, in the cerebellar stimulation group.Conclusion:Bilateral high-frequency rTMS of the cerebellum can improve the swallowing of persons with dysphagia, and shorten their oral transit time and swallow response time.

Immune checkpoint inhibitors(ICIs),including cytotoxic T-lymphocyte-associated protein 4(CTLA-4)inhibitors and programmed cell death receptor 1(PD-1)inhibitors and their ligand 1(PD-L1)inhibitors,have transformed the clinical outcomes of many patients with malignancies.programmed cell death receptor 1(PD-1)inhibitors and their ligand 1(PD-L1)inhibitors have changed the clinical outcomes of many patients with malignan-cies and have become the most important anti-tumor tools available.With the widespread use of immunotherapy,immune-related adverse events(irAEs)induced by ICIs have gradually attracted clinical attention,among which ICI-related colitis has become the most common adverse event in the gastrointestinal system.In this paper,we describe the epidemiology,pathogenesis and clinical management of ICI-related colitis,with the aim of providing reference for clinicians to identify and treat ICI-related colitis in a timely manner.

Objective To investigate the structure of deoxyhypusine synthase(DHS)in Saccharomyces cerevisiae(Dys1)and unravel the molecular mechanism of hypusine lysine modification,providing a theoretical basis for the treatment of highly proliferative diseases such as human immunodeficiency virus type 1(HIV-1)replication.Meth-ods Using the E.coli BL21 expression system,an in vitro expression vector was constructed and used to express the protein of Dys1.Dys1 protein samples were purified using methods such as affinity chromatography and molecu-lar sieving to achieve protein purification and isolation.The crystals of Dys1 were obtained using the crystallized so-lution containing 6％Polyethylene Glycol(PEG)8000,0.1 mol/L N-2-hydroxyethylpiperazine-N-ethane-sulphoni-cacid(Hepes)pH 6.5,and 8％ethylene glycol.The crystal structure of Dys1 was resolved at a resolution of 2.8 ? using X-ray crystallography.The structural analysis was performed with CCP4i and Coot software.Results The overall structure of Dys1 was a tetramer,each monomer containing a catalytic site and a cofactor NAD+binding site.The core region of the monomer adopted a Rossmann fold.The amino acid residues involved in the substrate binding sites were highly conserved among eukaryotes.Conclusion The crystal structure of Dys1 is being resolved for the first time.It reveals the binding mode of the cofactor NAD+to the enzyme and confirms that the enzyme functions as a tetramer,with the N-terminus serving as an essential modulator for its catalytic activity.

Objective:To investigate the application value of manual anastomosis of gastro-duodenum in totally laparoscopic distal gastrectomy.Methods:The retrospective cohort study was conducted. The clinicopathological data of 55 patients with gastric cancer who underwent totally laparoscopic distal gastrectomy combined with gastrointestinal anastomosis in the Tianjin Medical University Cancer Institute & Hospital from January 2020 to October 2022 were collected. There were 34 males and 21 females, aged 61(range, 29?75)years. Of 55 patients, 25 patients undergoing manual anastomosis of gastroduodenum were divided into the manual anastomosis group, 30 patients undergoing modified Delta anastomosis of gastroduodenum were divided into the modified Delta anastomosis group. Observation indicators: (1) surgical situations; (2) postoperative complications. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers, and comparison between groups was conducted using chi-square test or Fisher exact probility. Results:(1) Surgical situations. All 55 patients underwent surgery successfully, without conversion to laparotomy. The distance from the superior margin of tumor to the upper margin, anastomosis time, number of bookings used were (48±4)mm, (22.6±2.3)minutes, 3.2±0.5 in the manual anastomosis group, versus (41±4)mm, (14.0±1.4)minutes, 5.2±0.4 in the modified Delta anastomosis group, showing significant differences in the above indicators between the two groups ( t=5.04, 16.38, ?17.13, P<0.05). The location of tumor (antrum, gastric angle) was 18, 7 in the manual anastomosis group, versus 29, 1 in the modified Delta anastomosis group, showing a significant difference between the two groups ( P<0.05). (2) Postoperative complications. There was no patient undergoing anastomotic fistula in both of manual anastomosis group and modified Delta anastomosis group, and there was 1 patient undergoing anastomotic stenosis in the modified Delta anastomosis group. Conclusion:Compared with modi-fied Delta anastomosis of gastroduodenum,totally laparoscopic distal gastrectomy with manual anas-tomosis of gastroduodenum can remove more gastric tissue, and decrease the number of bookings used.

Objective:To observe any stimulatory effect of intermittent theta burst stimulation (iTBS) on the cerebral swallowing cortex and the cerebellar swallowing motor area and to explore the related mechanisms.Methods:Forty-four healthy right-handed subjects were divided at random into a dominant cerebellum group ( n=15), a non-dominant cerebellum group ( n=15) and a control group ( n=14). In the dominant cerebellum group, iTBS was administered to the cerebellum of the dominant hemisphere, and the other hemisphere was given sham stimulation. In the non-dominant cerebellum group, it was the opposite. The dominant cerebellum received the sham stimulation. In the control group both hemispheres received sham stimulation. Before and after the stimulation, single-pulse transcranial magnetic stimulation (TMS) was applied to the representative regions of suprahyoid muscles in bilateral brain and cerebellum to observe changes of the latency and amplitude of motor evoked potentials (MEPs). Results:After the intervention the MEP amplitude of the bilateral swallowing cortex and the stimulated cerebellum had increased in the non-dominant cerebellum group, with increased MEP amplitude only from the stimulated cerebellum of the dominant cerebellum group. Compared with the control group, the non-dominant cerebellum group showed the greatest improvement in MEP amplitude of the stimulated bilateral cerebral cortex and cerebellum. Improvement in the dominant cerebellum group was significantly smaller. However, there were no significant differences in MEP latency or the percentage change in MEP latency from baseline among the three groups.Conclusions:Applying iTBS to either the non-dominant or the dominant cerebellum excites the brain areas related to swallowing, but in different ways.

【Objective】 To develop an assay to determine β-lactam antibiotics using microcolumn gels and to study the β-lactam antibiotics present in the blood of patients and their clinical significances. 【Methods】 446 patients with a history of taking β-lactam antibiotics from January 2019 to June 2019 were randomly selected from Trauma Emergency Center, Department of Arthrosis, Department of Spine and Department of Bone Oncology of our hospital, and 4 mL(per capita) venous blood was collected. Irregular antibody screening, anti-globulin detection and drug antibody determination were performed by microcolumn gel method. The data of gender, age, disease, blood transfusion history and medication were collected. The test results and clinical data were retrospective analyzed. 【Results】 The yielding rate of antibody was 0.45%(2/446) in patients with a history of taking β -lactam antibiotics. 16.38%(73/446) of the samples were positive in direct antiglobulin test, and 64.38%(47/73) of them did not agglutinate with RBCs treated with drugs. The yielding rate of specific antibodies against drug was 4.93%(22/446), and the titer ranged from 2 to 128(8). 1 case of auto-IgM antibody, 1 case of blood group related antibody and 2 cases of non-specific protein adsorption were detected. The yielding rate of drug antibody in patients with blood transfusion history reached to 12.10 %(22/124), so it was also high in patients with bone tumor. 【Conclusion】 Direct antiglobulin assay is helpful for the detection of β-lactam antibodies. The negative results of antibody screening cannot completely exclude the presence of drug antibodies. The yielding rate of drug antibody can be greatly improved by specific drug antibody detection, and it was higher in transfused patients relative to non-transfused one.

The decrease of corneal stiffness is the key factor leading to keratoconus, and the corneal collagen fiber stiffness and fiber dispersion are closely related to the corneal biomechanical properties. In this paper, a finite element model of human cornea based on corneal microstructure, namely collagen fiber, was established before and after laser assisted in situ keratomileusis (LASIK). By simulating the Corvis ST process and comparing with the actual clinical results, the hyperelastic constitutive parameters and corneal collagen fiber stiffness modulus of the corneal material were determined before and after refractive surgery. After LASIK, the corneal collagen fiber stiffness modulus increased significantly, and was highly correlated with central corneal thickness (CCT). The predictive relationship between the corneal collagen fiber stiffness modulus and the corresponding CCT before and after surgery was: = exp(9.14 - 0.009CCT ), = exp(8.82 - 0.008CCT ). According to the results of this study, the central corneal thickness of the patient can be used to estimate the preoperative and postoperative collagen fiber stiffness modulus, and then a personalized corneal model that is more consistent with the actual situation of the patient can be established, providing a theoretical reference for more accurately predicting the safe surgical cutting amount of the cornea.
Biomechanical Phenomena ; Cornea ; Corneal Topography ; Finite Element Analysis ; Humans ; Keratomileusis, Laser In Situ ; Myopia

On February 11, 2019, a 37-year-old female patient with neuromyelitis optica spectrum disorders was admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine, and her acute osteomyelitis was caused by infection of multiple pressure ulcer wounds with Staphylococcus aureus. The patient was diagnosed and treated with multidisciplinary cooperation. The nurses focused on the strict observation of the syndrome of neuromyelitis optica spectrum disorders during hormone reduction therapy, guarded against the rebound of condition, implemented wound care in stages according to the diagnosis and treatment plan, maintained effective drainage, ensured appropriate negative pressure, and strengthened nutrition to promote wound healing. After active treatment and careful nursing care, the patient recovered and was discharged on the 39th day after admission.

It has been previously thought that calcification is a feature of the stability of atherosclerotic plaques. However, recent studies have shown that microcalcification in atherosclerotic plaques is significantly associated with plaque vulnerability. The relationship between atherosclerotic plaques and calcification is unclear, and the specific role of calcification in atherosclerotic plaques remains controversial.