[Changes in the expression of genes related to intestinal fatty acid oxidation and carnitine metabolism in patients with ulcerative colitis].

Objective: To investigate the changes in gene expression related to intestinal fatty acid oxidation and carnitine metabolism in patients with ulcerative colitis (UC). Methods: A retrospective study was conducted involving patients with UC (UC group) and non-UC controls (control group) who underwent routine colonoscopy to exclude polyps at Peking Union Medical College Hospital between January 1, 2018, to December 31, 2023. Colon tissue samples were collected from both groups and RNA was extracted. Real-time fluorescence quantitative polymerase chain reaction technology was used to detect the mRNA expression levels of genes related to fatty acid oxidation and carnitine metabolism and to analyze their correlation with inflammatory gene expression. The expression of genes linked to fatty acid oxidation and carnitine metabolism was analyzed by analyzing the colonic mucosal transcriptome data of UC patients and controls in high-throughput gene expression database (GEO). Immunohistochemistry was used to examine the expression of the carnitine transporter SLC6A14 in the intestinal tissues of both groups at the protein level. Eight-week-old male C57BL/6 mice were selected and divided into a drinking water group (drinkind daily water) and a dextran sodium sulfate (DSS) group (drinking 2.5% DSS solution) with 4 mice in each group. DSS was used to induce an acute colitis model in mice and detect the difference in mRNA expression levels of SLC6A14 and interleukin-6 (IL-6) in the intestinal tissues of the both groups of mice. Results: A total of 22 patients were included in the UC group, with 12 males and 10 females, aged 16-64 (40±12) years. The control group consisted of 10 patients, with 3 males and 7 females, aged 43-72 (64±8) years. The UC group had lower mRNA expression levels of genes related to fatty acid oxidation and transport in the intestine compared to those in the control group, such as CD36 [0.40 (0.27, 0.55) vs 0.93 (0.39, 2.93)], CPT1A [0.39 (0.07, 0.54) vs 0.93 (0.41, 1.71)], CPT1B (0.37±0.36 vs 1.37±0.89), CPT2 [0.36 (0.30, 0.43) vs 1.14 (0.68, 1.34)], CRAT [0.31 (0.25, 0.41) vs 1.06 (0.64, 1.73)], CROT [0.14 (0.10, 0.21) vs 0.95 (0.77, 1.27)] (all P<0.05). The mRNA expression levels of genes related to carnitine transport in the UC group were lower than those in the control group, such as OCTN1 [0.18 (0.10, 0.41) vs 0.83 (0.41, 1.47)], OCTN2 [0.01 (0.00, 0.01) vs 0.47 (0.35, 2.15)] (both P<0.05). The mRNA expression levels of the carnitine transporter gene SLC6A14 in the intestine of UC patients was higher than that of the control group [11.31 (5.34, 23.50) vs 0.78 (0.07, 3.70), P<0.001], and showed a positive correlation with the inflammatory gene IL-6 (r=0.425, 95%CI: 0.076-0.681, P=0.019). Analysis of the GEO database revealed lower expression levels of CD36, CPT1A, CPT2, CRAT and CROT in UC group compared to controls (all P<0.05), while the expression levels of SLC6A14 were higher than those in control group (P<0.05). The protein expression level of SLC6A14 in colon tissue of UC group was higher than that of control group (0.45±0.07 vs 0.30±0.01, P=0.019). The mRNA expression of SLC6A14 in the intestine of DSS group was higher compared to that in the drinking water group (1.83±0.90 vs 0.60±0.10, P=0.035). Conclusion: The expression levels of genes associated with intestinal fatty acid oxidation and carnitine metabolism (CD36, CPT1A, CPT1B, CPT2, CRAT, CROT, OCTN1, and OCTN2) are decreased in UC patients, while the expression level of SLC6A14, a gene capable of transporting both amino acids and carnitine, is increased.

[Molecular epidemiological characterization of hypervirulent carbapenem-resistant Klebsiella pneumoniae in a hospital in Henan Province from 2020 to 2022].

Objective: The study investigated the clinical distribution, antimicrobial resistance and epidemiologic characteristics of hypervirulent Carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) in a hospital in Henan Province to provide a scientific basis for antibiotic use and nosocomial infection prevention and control. Methods: A retrospective analysis of the clinical data from the cases was carried out in this study. Clinical data of patients infected with the CRKP strain isolated from the clinical microbiology laboratory of Henan Provincial Hospital of Traditional Chinese Medicine from January 2020 to December 2022 were retrospectively analyzed. A string test, virulence gene screening, serum killing, and a G. mellonella infection model were used to screen hv-CRKP isolates. The clinical characteristics of hv-CRKP and the drug resistance rate of hv-CRKP to twenty-five antibiotics were analyzed using WHONET 5.6. Carbapenemase phenotypic characterization of the hv-CRKP was performed by colloidal gold immunochromatographic assay, and Carbapenemase genotyping, multi-locus sequence typing (MLST) and capsular serotyping of hv-CRKP isolates were performed by PCR and Sanger sequencing. Results: A total of non-duplicate 264 CRKP clinical isolates were detected in the hospital from 2020 to 2022, and 23 hv-CRKP isolates were detected, so the corresponding detection rate of hv-CRKP was 8.71% (23/264). The hv-CRKP isolates in this study were mainly from the intensive care unit (10/23) and neurosurgery department (8/23), and the main sources of hv-CRKP isolates were sputum (10/23) and bronchoalveolar lavage fluid (6/23). The hv-CRKP isolates in this study were highly resistant to ß-lactam antibiotics, fluoroquinolones and aminoglycosides, and were only susceptible to colistin, tigecycline and ceftazidime/avibactam. The detection rate of the blaKPC-2 among 23 hv-CRKP isolates was 91.30% (21/23) and none of the class B and class D carbapenemases were detected. Results of MLST and capsular serotypes showed that ST11 type hv-CRKP was the dominant strain in the hospital, accounting for 56.52% (13/23), and K64 (9/13) and KL47 (4/13) were the major capsular serotypes. Conclusion: The hv-CRKP isolates from the hospital are mainly from lower respiratory tract specimens from patients admitted to the intensive care department and the drug resistance is relatively severe. The predominant strains with certain polymorphisms are mainly composed of the KPC-2-producing ST11-K64 and ST11-KL47 hv-CRKP isolates in the hospital.

[Constructions and advances of animal models of Pseudomonas aeruginosa infection].

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogenic bacterium with complex pathogenesis and drug resistance mechanisms. It has high morbidity and mortality and can cause acute and chronic infections in immunocompromised individuals, with lung infections, wound infections, and bloodstream infections being the most common. The animal infection model of P. aeruginosa is of great value for in-depth research on the pathogenicity, drug resistance, and therapeutic measures of P. aeruginosa by simulating the pathways of human bacterial infections. This article firstly summarizes the selection, anesthesia, and disposal of experimental animals in the construction of animal models of P. aeruginosa infection, and then reviews the methods of construction, model evaluation, and applications of animal models of P. aeruginosa pulmonary infection, wound infection, and bloodstream infection, in order to provide a reference for scientific research related to P. aeruginosa infectious diseases.

[Sensitization characteristics of Juniperus chinensis pollen in Beijing area].

Objective: To investigate the sensitization characteristics of Juniperus chinensis pollen in patients with allergic rhinitis and/or allergic asthma in Beijing area, and to explore the characteristics of Juniper chinensis pollen sensitized population. Methods: Patients with suspected allergic rhinitis and/or asthma from January 2017 to December 2019 in the outpatient department of Allergy Department of Beijing Shijitan Hospital were selected in this study. Skin prick test (SPT) was performed with Juniper chinensis pollen allergen reagent to compare different age and disease allergen distribution, and to observe the sensitization characteristics of its population. All of the analyses were performed using SAS software version 9.4. Results: A total of 8 380 patients were enrolled in the end. The total positive rate of Juniper chinensis pollen SPT reached 49.92% (4 183/8 380). The positive rate of Juniper chinensis pollen SPT was highest in the 10-14 age group, reaching 60.99% (283/464). Compared with other age groups, there was a statistical difference (χ²=266.77, P<0.01). The SPT positive rate of patients aged less than 10 years increased with the increase of age, while the SPT positive rate of patients aged over 40 years decreased with the increase of age. Single Juniper chinensis pollen was less allergenic, accounting for about 25.05% (1 048/4 183), and the patients' age was (35.21±12.39) years. Regardless of single Juniper chinensis pollen or other pollen allergies, allergic rhinitis was the main disease. Among the patients with SPT positive Juniper chinensis pollen combined with other inhaled pollen allergens, willow pollen accounted for the first (74.99%). The positive rate of Juniper chinensis pollen was the highest in patients with single allergic rhinitis, accounting for 52.05% (3 797/7 295), and the rate in patients with single allergic asthma was the lowest, accounting for 17.49% (53/303), with statistically difference (χ²=138.99, P<0.01). Conclusions: Juniper chinensis pollen is highly sensitized in patients with allergic rhinitis and/or allergic asthma in Beijing . The positive rate of SPT is highest among 10-14 age group, most of which showed strong positive reaction, and allergic rhinitis is more common in Juniper chinensis pollen sensitization diseases.

[Research progress on virulence factors of hypervirulent Klebsiella pneumoniae].

Hypervirulent Klebsiella pneumoniae, short for hvKP, is a hypervirulent variant of classical Klebsiella pneumoniae, which accounts for serious infection in healthy people, exhibits strong pathogenicity, high mortality and poor prognosis. At present, hvkp is of high prevalence all over the world, and the infection rate shows a continuous upward trend, which brings great challenges to public health security and clinical treatment. This paper summarized the research progress on virulence factors of hvkp, such as capsular polysaccharides, siderophore, lipopolysaccharide, adhesins and recently discovered Type Ⅵ secreting system, and aimed to deepen the understanding and recognition of hvKP.

[The 489th case: acute kidney injury, gross hematuria, nephrotic syndrome].

Onset with fever and back pain, an 81-year-old man had sudden oliguria and progressively elevated serum creatine from normal range to 660 µmol/L within 1 week after receiving contrast agents, various antibiotics, and several nonsteroidal anti-inflammation drugs. Urine output recovered after supportive treatment. However, his serum creatinine level rose again soon after a temporary decline accompanied by gross hematuria with almost normal morphology, nephrotic proteinuria, and hypoalbuminemia. Renal biopsy revealed necrotizing glomerulonephritis. Methylprednisolone was intravenously administrated 500 mg per day for 3 days, followed by oral glucocorticoids and cyclophosphamide. Gradually the patient's serum creatinine descended to 144 µmol/L.

[Reoperation rate and related factors in patients with Crohn's disease].

Objective: To analyze the cumulative reoperation rate of postoperative Crohn's disease (CD) patients and investigate the operation reasons and the effects of drugs on surgical recurrence. Method: Patients with Crohn's disease who had undergone intestinal resection from January 2000 to March 2020 in Peking Union Medical College Hospital were enrolled. Patients were divided into reoperation and non-reoperation group according to whether they had a second operation. And the basic characteristics and the reasons for the primary and second operation were retrospectively analyzed. Meanwhile, patients were divided into low-risk reoperation group and high-risk group based on risk stratification. Kaplan-Meier methods were performed to analyze the cumulative surgical recurrence rate and to compare the recurrence rate in different risk stratification and chi-square tests was used to analyze the effects of different maintenance drugs on reoperation. Result: A total of 160 patients were enrolled in the study. There were 110 males and 50 females, and the age at first operation was (35.6±14.1) years old. There were 40 patients in the reoperation group and 120 patients in the non-reoperation group. According to univariate analysis, the proportion of male gender(P=0.030), penetrating phenotype(P<0.001), history of appendectomy before the primary surgery(P=0.035) and no postoperative maintenance therapy (P<0.001) were higher in surgical recurrence group. In terms of the operation reasons, intestinal obstruction accounted for the highest proportion in the primary operation (26.9%, 43/160), while the intestinal fistula was the most common reason for reoperation (42.5%, 17/40). After the primary surgery, the cumulative reoperation rates at 1, 3, 5 and 10 years were 5.9% (9 cases), 12.3% (17 cases), 21.8% (25 cases) and 37.6% (34 cases), respectively. The ten years cumulative reoperation rate of the high-risk group was 42.8% (31 cases), which was much higher than that of low-risk group (19.8%, 3 cases), and the difference was statistically significant (P=0.006). There was no statistically significant difference in the surgical recurrence rate of low-risk group patients(P=0.076)whether maintenance therapies were added or not, while the recurrence rate of high-risk group patients who did not receive maintenance therapy was higher than those who received immunosuppressant with or without (±) 5-aminosalicylic acid (ASA) (P=0.001) and biological agent±5-ASA (P=0.001), and the difference was statistically significant. Conclusion: Patients with CD are still at risk of reoperation after surgery. Immunosuppressive agents and biologics can prevent patients from reoperation in high-risk groups.

[Research progress on the regulation mechanism of Pseudomonas aeruginosa biofilm].

Pseudomonas aeruginosa is one of the common multidrug-resistant bacteria in the clinic. Because it can produce a "protective" biofilm, it can affect the penetration and killing efficacy of antibacterial drugs, leading to the formation of a persistent and persistent chronic infection in the host. Biofilms make Pseudomonas aeruginosa resistant to antibacterials and evasive to the host's immune system. Therefore, traditional conventional antibacterials are difficult to achieve effective bactericidal treatment. Understanding the process of P. aeruginosa biofilm formation and the regulatory mechanisms that affect biofilms can provide ideas and methods for our future research on new antibacterial drugs.

[Analysis on clinical features of patients with ulcerative colitis associated colorectal cancer].

Objective: To analyze the clinical features of ulcerative colitis associated colorectal cancer (UC-CRC). Methods: A total of 869 inpatients with Ulcerative Colitis (UC) in Peking Union Medical Hospital from January 1998 to January 2018 were continuously enrolled. Clinical data and the outcome of colorectal cancer (CRC) were collected via medical records and telephone follow-up. Chi-square test and logistic regression model were used to analyze the data. Results: There were 16 patients in 869 UC inpatients who were diagnosed with CRC during a period of 7 548 person years and the incidence rate of UC-CRC was 1.84%. Compared to UC inpatients without CRC, a longer course of disease (OR=1.087, 95% CI:1.046-1.129) , a lower usage rate of 5-Aminosalicylic Acid(5-ASA) (OR=0.218, 95% CI:0.052-0.915) and a higher incidence rate of intestinal stenosis (OR=16.533, 95% CI:3.824-71.478) were found in UC inpatients with CRC. Conclusions: A long disease course is a risk factor for UC patients developing CRC, while 5-ASA therapy can reduce the risk of suffering from CRC. For UC patients with intestinal stenosis, CRC should be warned for occurring.