[Diaphragmatic dysfunction post-COVID-19 infection: report of two cases].

Following the global outbreak of COVID-19, many patients have suffered from multi-system complications and long-term sequelae caused by the virus. Diaphragm dysfunction is an obscure post-COVID-19 symptom. Although a few cases of diaphragm dysfunction caused by COVID-19 infection have been reported abroad, there are no relevant reports in China. Herein, we present two cases of patients with respiratory distress after COVID-19 infection. On admission, dynamic chest radiographs revealed diaphragm dysfunction in these patients. Further investigations including diaphragm ultrasound, neurophysiological examinations, transdiaphragmatic pressure measurements cranial MRI, and antibody testing for autoimmune diseases, were conducted. The final diagnoses were severe myasthenia gravis induced by COVID-19 infection and diaphragmatic nerve and muscle involvement caused by COVID-19 infection. Both patients showed improvement in symptoms after treatment. Therefore, we summarized our case, with a review of the relevant literature to improve the understanding of the disease and to provide clinical evidence for future diagnosis and treatment.

[A cross-sectional survey on the types of antiviral treatment plans for patients with chronic hepatitis B].

Objective: To understand the current antiviral treatment status and various clinical types of treatment plans in Xiamen City so as to explore ways to improve and optimize the diagnosis and treatment standards for chronic hepatitis B. Methods: A cross-sectional survey method was used to study the antiviral treatment status and treatment plans for chronic hepatitis B patients who visited and were diagnosed in the Department of Infectious Diseases and Hepatology of all tertiary hospitals in Xiamen City at 0:00~23:59 on May 25, 2022. Results: A total of 665 cases were surveyed in this study, with an antiviral treatment rate of 81.2%(540/665). The antiviral treatment rate of patients who accorded with the current guidelines for antiviral treatment indications was 85.8%(507/591). The antiviral treatment rate for 362 outpatients was 72.9%(264/362). Among them, the antiviral treatment rates were 80.1%, 89.3%, and 25.0%(226/282, 25/28, 13/52), respectively, for patients diagnosed with chronic hepatitis B, hepatitis B cirrhosis, and hepatitis B surface antigen-carrying status. The treatment plan for all outpatient patients was mainly oral nucleos(t)ide analogues, accounting for 59.1%(214/362). The antiviral treatment rate for 303 inpatients was 91.1%(276/303). The various clinical types of antiviral therapy rates among all patients were 70%~95%. The antiviral treatment plan for inpatients was mainly based on pegylated interferon alpha treatment, accounting for 72.6%(220/303). Conclusion: Antiviral treatment for chronic hepatitis B in Xiamen City can still be strengthened to meet the current demand for expanding antiviral treatment indications. Antiviral treatment rates and various types of treatment plans differ between outpatients and inpatients; thus, further awareness and acceptance of the goal of improving antiviral therapy, especially in outpatients, and the possibility for a clinical cure based on pegylated interferon alpha treatment are needed to maximize the benefit to more patients.

[A meta-analysis on prevalence of primary angle-closure glaucoma in the middle-aged and elderly chinese population].

Objective: To evaluate the prevalence and relevant factors of primary angle-closure glaucoma (PACG) in the middle-aged and elderly (40 years old and above) Chinese population. Methods: Epidemiological literature (of English and/or Chinese language) on prevalence of PACG in China between 2000 and 2022 were retrieved from PubMed, Embase, Web of Science, CNKI, and Wanfang database. Two researchers conducted the process of document retrieval, inclusion, quality assessment and data extraction independently based on inclusion and exclusion criteria. Disagreement was resolved by consensus with a third researcher. The heterogeneity among studies was assessed by using the I2 statistics, and a corresponding model was used for the meta-analysis. Subgroup analysis (gender, age, survey date, place of residence, diagnostic criteria, and temperature zone), as well as sensitivity analysis and publication bias analysis, were conducted. Results: Twenty-three studies were included in this research. Among them, eight were of high-quality and fifteen were of middle-quality. In the past 20 years, the PACG prevalence in middle-aged and elderly (40 years and older) Chinese population was 1.35% (95%CI:1.08% to 1.61%). Chinese women (1.40%) were more likely to have PACG than men (0.96%, P<0.01). The PACG prevalence had a positive correlation with age (P<0.01). The prevalence was similar between urban (1.3%) and rural (1.2%, P=0.61) areas. The PACG prevalence from studies in which the diagnostic criteria of PACG requested the symptom of vision or optic nerve damage (1.1%) was lower than that those without such requirement (1.7%, P<0.01). In mid-temperate zone, the prevalence was higher (1.7%, P=0.02). Conclusions: The PACG prevalence in middle-aged and elderly (40 years old and above) Chinese population was 1.35% in the last 20 years. The prevalence of PACG varies across age, regions, and other variations. This risk is higher in the elderly, women, and people in cold regions among Chinese population.

[Research progress on hepatotoxicity of acetaminophen].

Acetaminophen (APAP) is a widely used antipyretic and analgesic drug that is safe and effective in the therapeutic doses, but overdose may cause hepatotoxicity and even acute liver failure (ALF). Finding reliable biomarkers for APAP toxicity is not only a hot spot of current research, but also a problem that needs to be solved urgently. Clinicians should consider the existence of APAP hepatotoxicity when using APAP treatment, and explain that APAP may have a certain degree of dose dependence. This paper reviews the most promising biomarkers currently being evaluated, and expounds their application in the field of APAP hepatotoxicity, as well as the mechanism of mitochondrial damage and mitochondrial autophagy, thereby contributing to the diagnosis, prognosis, mechanism and research progress of therapeutic targets of APAP hepatotoxicity.

[Evaluation of contrast-enhanced ultrasound in the differential diagnosis of benign and malignant lateral cervical lymph nodes].

Objective: To investigate the value of contrast-enhanced ultrasound (CEUS) in the diagnosis of benign and malignant lateral cervical lymph nodes. Methods: One hundred and fifteen cases of suspected lymph nodes disease, 60 males, 55 females, between November 2018 and June 2019 from clinic and inpatient in Fujian Cancer Hospital were collected. Routine ultrasound and CEUS were performed in 115 cases of lateral cervical lymph nodes. All cases underwent ultrasound-guided biopsy, and were divided into two groups of benign and malignant lymph nodes according to pathological results. The differences between the two groups were analyzed and statistically analyzed. The rate and frequency were used to qualitatively describe the ultrasound performance and observed lymph node morphology between the two groups of routine ultrasound and CEUS. The sensitivity, specificity, accuracy, negative predictive value and positive predictive value were used to evaluate the efficacy of routine ultrasound and CEUS. Results: There were 37 cases of benign lymph nodes and 78 cases of malignant lymph nodes. In benign lymph nodes, 51.4% (19/37) showed uniform high enhancement, and 48.6% (18/37) showed uneven or circular enhancement with clear boundaries and no focal enhancement area. In malignant lymph nodes, 94.9% (74/78) showed uneven enhancement, and only 5.1% (4/78) showed uniform enhancement. The difference of ultrasonic contrast medium uniformities in differentiating benign from malignant was statistically significant (P<0.001). The sensitivity, accuracy, negative predictive value and positive predictive value of routine ultrasound to differentiate benign and malignant lymph nodes were 64.1%, 65.2%, 47.2%, and 66.7%, respectively, while the corresponding values of CEUS were 93.6%, 75.7%, 73.7% and 83.9%. Conclusion: CEUS may provide a valuable basis for the differential diagnosis of benign and malignant lateral cervical lymph nodes.

[Temporary acceleration of interstitial fluid drainage in excited brain region induced by movement].

OBJECTIVE: To investigate the changes of brain interstitial fluid (ISF) induced by movement. METHODS: Twenty mature male Sprague-Dawley rats were randomly divided into two groups: control group and movement group. Electrophysiological neurons in caudate nuclear of additional five rats were recorded and the differences analyzed between under anesthesia and by movement. In the control group, the rats were anesthetized using isoflurane continuously during the experiment process. In the meantime the magnetic tracer was injected into the center of the caudate nucleus and multi-period magnetic resonance scanning was performed at several time points until high signal intensity invisible in the images. In the movement group, the rats were anesthetized for the injection of the tracer, and the first post-injection magnetic resonance scanning was performed. Then the rats were waken and allowed moving voluntarily for 20 minutes. The rats were anesthetized again and multi-period magnetic resonance scanning was performed until the experiment ended. NanoDetect system (Version 1.2, MRI lab, Beijing, China) was used to measure the parameters on ISF, which included the weighed signal intensity (weighed ΔSI) , the term predicting the amount of the tracer, and half-time of the tracer. In movement group, the weighed ΔSI at the time points of pre-movement and 10, 40, 70, 130, and 190 minutes after movement were calculated respectively. In control group, the weighed ΔSI at the same time points also were measured. The weighed ΔSI and half-time were compared between the two groups. RESULTS: The electrophysiological recording and data analysis showed significant difference in the local field potential of Caudate Nucleus between under anesthesia and by movement. The weighed ΔSI (unit: ΔSI×mm3) values of the two groups, presented by movement group vs. control group, were as followings, 60 257.1±23 069.2 vs. 61 072.0±19 547.3 at pre-move, 83 624.3±21 475.7 vs. 71 218.1±12 586.5 at 10 min after movement, 57 336.0±36 243.4 vs. 69 756.1±13 306.0 at 40 min after movement, 43 705.9±10 246.3 vs. 55 443.2±20 733.3 at 70 min after movement, 7 734.9±2 645.2 vs. 8 967.6±2 007.3 at 130 min after movement and 2 497.3±987.5 vs. 3 013.2±1 760.8 at 190 min after movement. Moreover, at 40 min after movement, the weighed ΔSI of movement group was significantly reduced compared with control group (P<0.05). The half-time was not significantly different [(104.3±54.1) min vs. (113.4±47.3) min, P>0.05]. CONCLUSION: ISF drainage of caudate nuclear can be acclerated temporarily by movement.

[Application and influencing factors of endorectal ultrasound in T-stage restaging of rectal cancer following neoadjuvant therapy].

Objective: To evaluate the accuracy and influencing factors of T-stage restaging of rectal cancer following neoadjuvant therapy with endorectal ultrasonography (ERUS). Methods: In a retrospective study, endorectal ultrasound was performed in 86 patients with rectal cancer following neoadjuvant therapy. The imaging results were compared with postoperative pathological T-stage. Results: The accuracy of overall T-stage restaging with ERUS was 67.4% (58/86). Additionally, the accuracy of restaging in middle and high rectal cancer was higher, with an accuracy of 76.1%(35/46)and 100%(4/4) respectively. Univariate analysis showed that the location of tumors was an independent factor affecting the accuracy of ERUS(P=0.033). Conclusion: ERUS is an effective method to restage T-stage of rectal cancer following neoadjuvant therapy.

[Value of dual contrast-enhanced ultrasound in the preoperative T staging of rectal carcinoma].

Objective: To explore the value of dual contrast-enhanced ultrasound in preoperative T staging of rectal carcinoma. Methods: Dual contrast-enhanced ultrasound examinations were performed on 72 patients with rectal carcinoma via transrectal infusion and intravenous injection. The accordance of preoperative dual contrast-enhanced ultrasound results and postoperative pathologic results was evaluated retrospectively. Results: The overall accordance rate of preoperative T staging was 73.6% (53/72). And accordance rate was 100.0% (3/3), 100.0% (5/5), 68.4% (13/19), 71.4% (25/35)and 70.0% (7/10) for Tis , T1, T2, T3 and T4, respectively. The consistency was good (κ=0.607, χ(2) =8.363, P<0.01). The accordance rate of middle/lower vs high rectal carcinoma was 68.7% and 85.7%. Conclusion: Dual contrast-enhanced ultrasound can provide reference for preoperative T staging for patients with rectal carcinoma.

[Application of three-dimensional printing personalized acetabular wing-plate in treatment of complex acetabular fractures via lateral-rectus approach].

Objective: To investigate reduction and fixation of complex acetabular fractures using three-dimensional (3D) printing technique and personalized acetabular wing-plate via lateral-rectus approach. Methods: From March to July 2016, 8 patients with complex acetabular fractures were surgically managed through 3D printing personalized acetabular wing-plate via lateral-rectus approach at Department of Orthopedics, the Third Affiliated Hospital of Southern Medical University. There were 4 male patients and 4 female patients, with an average age of 57 years (ranging from 31 to 76 years). According to Letournel-Judet classification, there were 2 anterior+ posterior hemitransverse fractures and 6 both-column fractures, without posterior wall fracture or contralateral pelvic fracture. The CT data files of acetabular fracture were imported into the computer and 3D printing technique was used to print the fractures models after reduction by digital orthopedic technique. The acetabular wing-plate was designed and printed with titanium. All fractures were treated via the lateral-rectus approach in a horizontal position after general anesthesia. The anterior column and the quadrilateral surface fractures were fixed by 3D printing personalized acetabular wing-plate, and the posterior column fractures were reduction and fixed by antegrade lag screws under direct vision. Results: All the 8 cases underwent the operation successfully. Postoperative X-ray and CT examination showed excellent or good reduction of anterior and posterior column, without any operation complications. Only 1 case with 75 years old was found screw loosening in the pubic bone with osteoporosis after 1 month's follow-up, who didn't accept any treatment because the patient didn't feel discomfort. According to the Matta radiological evaluation, the reduction of the acetabular fracture was rated as excellent in 3 cases, good in 4 cases and fair in 1 case. All patients were followed up for 3 to 6 months and all patients had achieved bone union. According to the modified Merle D'Aubigné and Postel scoring system, 5 cases were excellent, 2 cases were good, 1 case was fair. Conclusions: Surgical management of complex acetabular fracture via lateral-rectus approach combine with 3D printing personalized acetabular wing-plate can effectively improve reduction quality and fixation effect. It will be truly accurate, personalized and minimally invasive.

[Forensic Analysis of 20 Dead Cases Related to Heroin Abuse].

OBJECTIVES: To perform retrospective analysis on 20 dead cases related to heroin abuse, and to provide references for the forensic assessment of correlative cases. METHODS: Among 20 dead cases related to heroin abuse, general situation, using method of drug, cause of death and result of forensic examination were analyzed by statistical analysis for summarizing the cause of death and pathologic changes. RESULTS: The dead were mostly young adults, with more male than female. The results of histopathological examinations showed non-specific pathological changes. There were four leading causes of death, including acute poisoning of heroin abuse or leakage （13 cases, 65%）, concurrent diseases caused by heroin abuse （3 cases, 15%）, inspiratory asphyxia caused by taking heroin （2 cases, 10%）, and heroin withdrawal syndrome （2 cases, 10%）. CONCLUSIONS: The forensic identification on dead related to heroin abuse must base on the comprehensive autopsy, and combine with the qualitative and quantitative analysis of heroin and its metabolites in death and the case information, as well as the scene investigation.

Dexmedetomidine reduces intestinal and hepatic injury after hepatectomy with inflow occlusion under general anaesthesia: a randomized controlled trial.

BACKGROUND: We compared intestinal, hepatic, and other organ function after hepatic portal occlusion with or without dexmedetomidine administration under general anaesthesia. METHODS: In this prospective, randomized double-blind investigation, 44 patients undergoing elective hepatectomy with inflow occlusion were randomized into a dexmedetomidine group or a control group. The dexmedetomidine group received an initial dexmedetomidine loading dose of 1 µg kg(-1) over 10 min followed by a maintenance dose of 0.3 µg kg(-1) h(-1). In the control group, 0.9% sodium chloride was administered. The primary outcome was serum diamine oxidase (DAO) activity reflecting intestinal injury. The secondary outcomes included variables reflecting intestinal, hepatic, kidney, and cardiopulmonary function, and biomarkers of oxidative stress and systemic inflammatory response. RESULTS: DAO activity was lower in the dexmedetomidine group than in the control group at 6 and 24 h after liver reperfusion [9.77 (1.07) vs14.29 (1.43) units ml(-1), P=0.021; 9.67 (0.98) vs 13.97 (1.31) units ml(-1), P=0.017]. d-lactate acid levels were lower during 1-72 h after liver reperfusion compared with the control group (all P<0.05). Also, the intestinal injury severity grade was decreased by dexmedetomidine (P=0.038). The biomarkers reflecting liver injury increased over time, but were lower in the dexmedetomidine group (all P<0.05), while the variables reflecting cardiopulmonary and renal function showed no differences between the groups (all P>0.05). CONCLUSIONS: Dexmedetomidine administered perioperatively attenuates intestinal and hepatic injury in patients undergoing elective liver resection with inflow occlusion without any potential risk. CLINICAL TRIAL REGISTRATION: ChiCTR-TRC-11001530, September 2011.

[Effects and clinical significance of NLRP3 inflammasome activated by IL-17A in CRSwNP].

Objective: To investigate the effects and clinical significance of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activated by interleukin (IL)-17A in chronic rhinosinusitis with nasal polyps (CRSwNP). Methods: Patients underwent nasal endoscopic surgery in the Third Affiliated Hospital of Sun Yat-sen University from January 2020 to December 2021 were collected, including 28 CRSwNP (including 19 males and 9 females, aged 19 to 67 years), 22 chronic rhinosinusitis without nasal polyps (CRSsNP) and 22 controls. qRT-PCR was used to detect the expressions of IL-17A, NLRP3, IL-1ß and IL-18 in the three groups, and their correlations were analyzed. The positions of IL-17A, NLRP3 and IL-18 in nasal polys were analyzed by immunofluorescence. Western Blotting and ELISA were employed to detect the expression of NLRP3, IL-1ß and IL-18 in the human nasal epithelial cells after using IL-17A stimulation or IL-17A receptor inhibitor. Immunofluorescence was used to observe the NLRP3, IL-1ß, and IL-18 protein expression after IL-17A stimulating human nasal epithelial cells, and after the use of IL-17A receptor inhibitor and NLRP3 inhibitor MCC950. The correlations between NLRP3, IL-1ß, IL-18 and CT scores, nasal endoscopic scores, visual analogue scale (VAS) scores, and sino-nasal outcome test (SNOT) 22 scores of CRSwNP patients were analyzed. SPSS 20.0 software was used for statistical analysis. Results: The expressions of IL-17A, NLRP3, IL-1ß and IL-18 in the tissues of CRSwNP patients were significantly higher than those in CRSsNP group(P=0.018,P<0.001,P=0.005, P=0.016) and the control group(all P<0.001). IL-17A was positively correlated with the expression of NLRP3, IL-1ß, and IL-18(r ralue was 0.643,0.650,0.629,respectively, all P<0.05). IL-17A, NLRP3, and IL-18 were co-localized in the epithelial propria of polyp tissue. IL-17A stimulated the expressions of NLRP3, IL-1ß, and IL-18 in human nasal epithelial cells. After the use of IL-17A receptor inhibitor, the expressions of NLRP3, IL-1ß, and IL-18 were significantly down-regulated. After the use of NLRP3 inhibitor MCC950, IL-17A was significantly down-regulated to promote the expression of NLRP3, IL-1ß, and IL-18. The expressions of NLRP3, IL-1ß and IL-18 were positively correlated with CT, nasal endoscopy, VAS, and SNOT22 scores in patients with CRSwNP. Conclusions: IL-17A promotes the release of IL-1ß and IL-18 by activating the NLRP3 inflammasome and aggravates the severity of the disease in CRSwNP.

Single sevoflurane exposure decreases neuronal nitric oxide synthase levels in the hippocampus of developing rats.

BACKGROUND: The use of general anaesthetics in young children and infants has raised concerns regarding the adverse effects of these drugs on brain development. Sevoflurane might have harmful effects on the developing brain; however, these effects have not been well investigated. METHODS: Postnatal day 7 (P7) Sprague-Dawley rats were continuously exposed to 2.3% sevoflurane for 6 h. We used the Fox battery test and Morris water maze (MWM) to examine subsequent neurobehavioural performance. Cleaved caspase-3 and neuronal nitric oxide synthase (nNOS) were quantified by immunoblotting, and the Nissl staining was used to observe the histopathological changes in the hippocampus. RESULTS: A single 6 h sevoflurane exposure at P7 rats resulted in increased cleaved caspase-3 expression and decreased nNOS levels in the hippocampus, and induced the loss of pyramidal neurones in the CA1 and CA3 subfields of the hippocampus at P7-8. These changes were accompanied by temporal retardation of sensorimotor reflexes. However, neither the Fox battery test at P1-21 nor the MWM test at P28-32 showed differences between the air- and sevoflurane-treated groups. CONCLUSIONS: Although early exposure to sevoflurane increases activated caspase-3 expression and neuronal loss and decreases nNOS in the neonatal hippocampus, it does not affect subsequent neurobehavioural performances in juvenile rats.

[The expression profile and potential regulatory mechanism of ACE2 in chronic rhinosinusitis with nasal polyps].

Objective: To preliminarily analyze the expression of angiotensin-converting enzyme 2 (ACE2) and to investigate its potential regulatory mechanism in chronic rhinosinusitis with nasal polyps (CRSwNP). Methods: Patients underwent nasal endoscopic surgery in the Third Affiliated Hospital of Sun Yat-sen University from February 2020 to May 2021 were selected, including 17 males and 6 females, aging from 23 to 66 years old. Expression of ACE2 was evaluated via immunohistochemical staining in controls with non-chronic rhinosinusitis, non-eosinophilic CRSwNP (non-ECRSwNP), and eosinophilic CRSwNP (ECRSwNP) tissue, respectively. Correlations between ACE2 and the indicated Th1/Th2-related cytokines (IFN-γ, IL-4, IL-5, IL-13, IL-25, IL-33, TSLP and periostin) were analyzed based on GSE72713 dataset. Protein-protein interaction (PPI) network was constructed via string database, immune infiltration of GSE72713 dataset was evaluated using cibersort algorithm. ACE2 was comprehensively analyzed by microRNA regulatory network, gene set enrichment analysis (GSEA) and pharmacological analysis. Statistical analysis was performed using GraphPad 7.0 and SPSS 20.0 software. Results: ACE2 was up-regulated in non-ECRSwNP compared with ECRSwNP. Microarray analysis showed that ACE2 was positively correlated with IFN-γ while inversely correlated with IL-5, IL-13 and periostin significantly. Analysis of immune infiltration suggested that ACE2 expression correlated positively with the number of M1 macrophage while negatively with M2 macrophage. GSEA demonstrated that interferon-related signaling pathways were up-regulated in non-ECRSwNP, and miRNA-200B/miRNA-200C/miRNA-429 pathways targeting ACE2 were enriched in ECRSwNP. Results of pharmacological analysis indicated that ampicillin was able to promote the expression of ACE2 whereas acetaminophen could down regulated the expression of ACE2. Conclusion: Expression pattern of ACE2 is varied in non-ECRSwNP and ECRSwNP, which may be related to the different infiltration of indicated cytokines and different regulatory pathways of miRNA.

[Clinical application of self-made drainage tubes in different layers of soft tissue for negative-pressure wound therapy in 33 patients].

From January 2014 to June 2018, 28 patients with different types of deep soft tissue injury or infection were admitted to the Affiliated Jiangyin Hospital of Medical College of Southeast University; 5 patients were admitted to the Zhengzhou First People's Hospital. There were 24 males and 9 females, aged 18-89 (40±20) years. Disposable suction tubes with holes cut on side walls were used as self-made drainage tubes. The authors placed the self-made drainage tubes on different deep soft tissue layers and wound surfaces after debridement. The effective drainage sections of the wound surface drainage tubes were wrapped with silver ion antimicrobial functional active dressings. Bio-permeable membrane was used to close the operative area. The drainage tubes in the deep layer of wound and wound surface were connected in parallel by a tee and connected to wall-hanging medical negative-pressure suction device to conduct negative-pressure wound treatment at -20.0 to -10.6 kPa. The deep drainage tubes were usually removed or changed 4 or 5 days after surgery.The drainage tubes in the wound surface were synchronously replaced when removing or replacing he drainage tubes in the deep layer of wound. On 4 to 15 days after surgery, the deep drainage tubes were removed. On 8 to 25 days after surgery, the wound surface drainage tubes were removed. Then the treatment was changed to a conventional dressing change until the wounds were completely healed or the wound bed was ready for skin grafts or tissue flaps. The indwelling time of deep drainage tubes in this group of patients was (6.2±2.8) days, and the indwelling time of wound surface drainage tubes was (12.0±3.0) days. The wound healing time was (22±5) days, the hospital stay time was (29±7) days, and wound bacteria were reduced from 6 species and 11 strains before treatment to 3 species and 4 strains after treatment. No adverse events such as wound bleeding, irritative pain, and chronic sinus occurred during treatment. Twenty-three patients were followed up for 13 to 28 months, no treatment-related complications were observed.

[Effect of peripheral bloodgenomic DNA methylation on the relationship between methyl donor status and risk of breast cancer].

Objective: To explore the effect of peripheral blood genomic DNA methylation on the relationship between methyl donor status and risk of breast cancer. Methods: A case-control study was conducted. Each three hundred breast cancer cases and controls were consecutively recruited. Food frequency questionnaire was used to collect dietary information. Amounts on folate, methionine, choline and betaine intake were calculated. Blood samples were collected for DNA extraction. Peripheral blood genomic DNA methylation was measured by using the Methyl Flash(TM) Methylated DNA Quantification Kit. Pathway analysis was used to examine the effect of genomic DNA methylation on the relations between methyl donor status and risk of breast cancer. Results: The genome DNA methylation rates were 0.46%±0.25% and 0.53%±0.34%, respectively on both cases and controls, with differences statistically significant (P<0.01). Results from the pathway analysis, results showed that methionine consumption was related to genomic DNA methylation (ß=0.065, P<0.05) while genomic DNA methylation was related to the risk of breast cancerk (ß=-0.027, P<0.05), respectively. Conclusions: The level of peripheral blood genomic DNA methylation in breast cancer cases was significantly lower than that in the controls. Genomic DNA methylation seemed to have played a mediated role between methionine and the risk of breast cancer.

Bone marrow endothelial cells secrete thymosin beta4 and AcSDKP.

Bone marrow endothelial cells are the essential component of the bone marrow microenvironment. They produce many kinds of cytokines, including stimulators and inhibitors. Many researchers have suggested that in the presence of endothelial cell layer, CD34+CD38- cells are capable of expansion. The ability of the endothelial cell layer to protect hematopoietic stem cells from extensive differentiation may be related to the inhibitors derived from endothelial cells. The aim of the present study was to determine whether the inhibitors thymosin beta4 and AcSDKP are elaborated by murine bone marrow endothelial cells. Murine bone marrow endothelial cells (mBMECs) were cultured in serum-free conditioned medium. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to analyze the differential expression of the thymosin-beta gene, and reverse phase high-performance chromatography (HPLC) and mass spectroscopy were used to determine the concentration of thymosin beta4 (Tbeta4) and AcSDKP in EC lysate and in the medium (mBMEC-CM). Colony-forming unit granulocyte-macrophage (CFU-GM) colony assays were used to examine the effect of components (mw 3-10 kD, <3 kD) of mBMEC-CM, thymosin beta4, and AcSDKP on the proliferation of hematopoietic cells.mBMECs expressed Tbeta4 mRNA. In EC lysate and mBMEC-CM, Tbeta4 and AcSDKP were detected. After adding protease inhibitors, the concentration of Tbeta4 in EC lysate increased significantly, while the concentration of AcSDKP decreased. mBMEC-CM (mw 3-10 kD) had no effect on the formation of CFU-GM. However, mBMEC-CM (mw <3 kD) could inhibit the growth of CFU-GM. Tbeta4 (10(-11) approximately 10(-7)mol/L) and AcSDKP (10(-11) approximately 10(-5)mol/L) had dose-dependent inhibitory effects on the growth of CFU-GM. Angiotensin converting enzyme (ACE), the enzyme degrading AcSDKP, could partially eliminate the inhibitory effect of mBMEC-CM (mw <3 kD) on CFU-GM.BMECs express and secrete Tbeta4 and AcSDKP. Tbeta4 exists in the 3-10 kD component of mBMEC-CM, while AcSDKP exists in the <3 kD component of ECCM. Both components exert inhibitory effects on the proliferation of hematopoietic progenitors.