Effects of lncRNA FEZF1-AS1 on proliferation,migration and invasion through regulating EZH2 of lung interstitial cells / 基础医学与临床

Objective To investigate the effects of long non-coding RNA FEZ family zinc finger 1 antisense RNA 1(lncRNA FEZF1-AS1)on enhancer of zeste homolog 2(EZH2)in regulation of proliferation,migration,invasion and epithelial-mesenchymal transition(EMT)of pulmonary interstitial cells and its mechanism.Methods The A549 cells human lung adenocarcinoma cell line were divided into control group and model group[model cells were induced into lung interstitial cells after being treated with transforming growth factor β1(TGF-β1)20 ng/mL for 48 h].The protein expression of E-cadherin,N-cadherin and vimentin in each group was detected by Western blot.The expression of lncRNA FEZF1-AS1 and EZH2 in the two groups was detected by RT-qPCR.Cells in the trans-fection group were divided into si NC group,lncRNA FEZF1-AS1+OE vector group and si lncRNA FEZF1-AS1+OE EZH2 group.Cell proliferation was examined by CCK-8 method,cell migration was detected by cell scratch,and cell invasion was detected by Transwell assays.The protein expression of E-cadherin,N-cadherin,vimentin and EZH2 in each group was detected by Western blot.The direct binding effect of FEZF1-AS1 and EZH2 was deter-mined by RNA immuno-precipitation(RIP).Results Compared with the control group,the protein expression level of E-cadherin in the model group was significantly decreased(P＜0.05),and the protein expression of N-cadherin and vimentin was significantly increased(P＜0.05).Compared with the control group,the expression level of lncRNA FEZF1-AS1 and EZH2 genes was significantly increased in the model group(P＜0.05).Compared with si NC group,the proliferation,migration and invasion ability of si lncRNA FEZF1-AS1+OE vector group were decreased,the ex-pression of E-cadherin protein was increased while the expression of N-cadherin,vimentin and EZH2 was decreased(P＜0.05).Compared with si lncRNA FEZF1-AS1+OE vector group,the proliferation,invasion and migration of si lncRNA FEZF1-AS1+OE EZH2 group were increased(P＜0.05).E-cadherin expression was decreased,while N-cad-herin,vimentin and EZH2 expressions were increased(P＜0.05).RIP experiment further confirmed that lncRNA FEZF1-AS1 had direct binding effect with EZH2.Conclusions LncRNA FEZF1-AS1 can promote the proliferation,invasion,metastasis and EMT process of pulmonary fibrosis cells by regulating EZH2.

The effect of lncRNA FEZF1-AS1 targeting regulation of miR-200c-3p on biological behaviors of human lung fibroblasts / 天津医药

Objective To investigate the effect of FEZ family zinc finger 1-antisense RNA 1(LncRNA FEZF1-AS1)targeting regulation of miR-200c-3p expression on biological behaviors of human lung fibroblasts(HLF).Methods Transforming growth factor β1(TGF-β1)was used to induce the transformation of HLF into myofibroblasts,which were divided into the Blank group and the model group(HLF+TGF-β1 group).According to different transfection plasmid,cells were divided into the Blank group,the TGF-β1+Si LncRNA FEZF1-AS1 NC group and the TGF-β1+Si LncRNA FEZF1-AS1 group.The protein expressions of α-SMA,Collagen Ⅰ and Vimentin were detected by Western blot assay.The expressions of LncRNA FEZF1-AS1 and miR-200c-3p were detected by quantitative real-time PCR(qRT-PCR).Cell proliferation ability was detected by CCK-8 method,migration ability was detected by cell scratch experiment and invasion ability was detected by Transwell assay.The targeting relationship between FEZF1-AS1 and miR-200c-3p was detected by dual-luciferase reporter assay.Results Compared with the Blank group,protein expressions of α-SMA,Collagen Ⅰ,Vimentin and the expression of LncRNA FEZF1-AS1 were increased in the HLF+TGF-β1 group(P＜0.05),and the expression of miR-200c-3p was decreased(P＜0.05).Compared with the TGF-β1+Si LncRNA FEZF1-AS1 NC group,cell proliferation,migration,invasion ability,LncRNA FEZF1-AS1 expression,protein expressions of α-SMA,Collagen Ⅰ and Vimentin were decreased in the TGF-β1+Si LncRNA FEZF1-AS1 group(P＜0.05),and the expression of miR-200c-3p was increased(P＜0.05).There were binding sites between miR-200c-3p and FEZF1-AS1 gene sequence.Conclusion LncRNA FEZF1-AS1 promotes the formation and progression of idiopathic pulmonary interstitial fibrosis by inhibiting miR-200c-3p.

Xenogeneic Humoral Immune Responses to Human Mesenchymal Stem Cells in Mice

Background and Objectives@#Many preclinical studies have been conducted using animal disease models to determine the effectiveness of human mesenchymal stem cells (hMSCs) for treating immune and inflammatory diseases based on the belief that hMSCs are not immunogenic across species. However, several researchers have suggested xenogeneic immune responses to hMSCs in animals, still without detailed features. This study aimed to investigate a xenogeneic humoral immune response to hMSCs in mice in detail. @*Methods@#and Results: Balb/c mice were intraperitoneally injected with adipose tissue-derived or Wharton’s jelly-derived hMSCs. Sera from these mice were titrated for each isotype. To confirm specificity of the antibodies, hMSCs were stained with the sera and subjected to a flow cytometic analysis. Spleens were immunostained for proliferating cell nuclear antigen to verify the germinal center formation. Additionally, splenocytes were subjected to a flow cytometric analysis for surface markers including GL-7, B220, CD4, CD8, CD44, and CD62L. Similar experiments were repeated in C57BL/6 mice. The results showed increased IgG 1 and IgG 2a titers in the sera from Balb/c mice injected with hMSCs, and the titers were much higher in the secondary sera than in the primary sera. These antibodies were specifically stained the hMSCs. Germinal centers were observed in the spleen, and flow cytometric analysis of the splenocytes showed higher frequencies of centroblasts (B220 ＋ GL7 ＋ ) and memory T cells (CD62L ＋ CD44 ＋ ) both in CD4 ＋ and CD8 ＋ subsets. Similar results were obtained for C57BL/6 mice. @*Conclusions@#hMSCs induced a humoral immune response in mice, with characters of T cell-dependent immunity

Vitamin C is taken up by human T cells via sodium-dependent vitamin C transporter 2 (SVCT2) and exerts inhibitory effects on the activation of these cells in vitro / 대한해부학회지

Vitamin C is an essential micronutrient that affects immune responses. T cells are one of the main players in acquired immunity and have been reported to be influenced by in vivo vitamin C supplementation. Yet, the way by which T cells uptake vitamin C and what direct effects vitamin C exerts on the cells are not known. To elucidate, we isolated human peripheral blood T cells and analyzed the expression of sodium-dependent vitamin C transporters (SVCT). T cells were activated in vitro in the absence or presence of vitamin C, before or after activation. As results, human T cells expressed SVCT2, but not SVCT1, and the expression level increased following activation. Vitamin C added in the culture media generally did not affect T-cell behaviors following activation, such as proliferation, apoptosis, expression of CD25 and CD69, and interleukin 2 secretion, regardless whether it was added before or after activation. However, exceptionally, high concentration vitamin C, when it was added before activation, but not after activation, did exert toxic effects on cell activation with respect to the above-mentioned parameters. In conclusion, we showed the expression of SVCT2 in human T cells for the first time. Vitamin C exerted toxic effects, at least in vitro, when the concentration was high and when it was given before activation. These toxic effects are not thought to be via anti-oxidant effects of vitamin C.

Ethanolic Extract of the Seed of Zizyphus jujuba var. spinosa Ameliorates Cognitive Impairment Induced by Cholinergic Blockade in Mice

In the present study, we investigated the effect of ethanolic extract of the seed of Zizyphus jujuba var. spinosa (EEZS) on cholinergic blockade-induced memory impairment in mice. Male ICR mice were treated with EEZS. The behavioral tests were conducted using the passive avoidance, the Y-maze, and the Morris water maze tasks. EEZS (100 or 200 mg/kg, p.o.) significantly ameliorated the scopolamine-induced cognitive impairment in our present behavioral tasks without changes of locomotor activity. The ameliorating effect of EEZS on scopolamine-induced memory impairment was significantly reversed by a sub-effective dose of MK-801 (0.0125 mg/kg, s.c.). In addition, single administration of EEZS in normal naive mouse enhanced latency time in the passive avoidance task. Western blot analysis was employed to confirm the mechanism of memory-ameliorating effect of EEZS. Administration of EEZS (200 mg/kg) increased the level of memory-related signaling molecules, including phosphorylation of extracellular signal-regulated kinase or cAMP response element-binding protein in the hippocampal region. Also, the time-dependent expression level of brain-derived neurotrophic factor by the administration of EEZS was markedly increased from 3 to 9 h. These results suggest that EEZS has memory-ameliorating effect on scopolamine-induced cognitive impairment, which is mediated by the enhancement of the cholinergic neurotransmitter system, in part, via NMDA receptor signaling, and that EEZS would be useful agent against cognitive dysfunction such as Alzheimer's disease.

Suppression of in vitro murine T cell proliferation by human adipose tissue-derived mesenchymal stem cells is dependent mainly on cyclooxygenase-2 expression / 대한해부학회지

Mesenchymal stem cells (MSCs) of human origin have been frequently applied to experimental animal models to evaluate their immunomodulatory functions. MSCs are known to be activated by cytokines from T cells, predominantly by interferon-gamma (IFN-gamma), in conjunction with other cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interlukin-1beta. Because IFN-gamma is not cross-reactive between human and mouse species, the manner in which human MSCs administered in experimental animals are activated and stimulated to function has been questioned. In the present study, we established MSCs from human adipose tissue. They successfully suppressed the proliferation of not only human peripheral blood mononuclear cells but also mouse splenic T cells. When these human MSCs were stimulated with a culture supernatant of mouse T cells or recombinant murine TNF-alpha, they expressed cyclooxygenase-2 (COX-2), but not indoleamine 2,3-dioxygenase. The dominant role of COX-2 in suppressing mouse T cell proliferation was validated by the addition of COX-2 inhibitor in the co-culture, wherein the suppressed proliferation was almost completely recovered. In conclusion, human MSCs in a murine environment were activated, at least in part, by TNF-alpha and mainly used COX-2 as a tool for the suppression of in vitro T cell proliferation. These results should be considered when interpreting results for human MSCs in experimental animals.

Correlation of resistance to peer pressure and risky decision-making with adolescent health risk behaviors / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore possible interrelationships among resistance to peer pressure, risky decision-making and health risk behaviors among young adolescents.</p><p><b>METHODS</b>Based on the cluster sampling method, the participants who were recruited from 5 junior middle schools in Guangzhou and 3 junior middle schools in Shenyang city on October, 2010, were administered to complete the questionnaire concerned with their experiences with drinking and smoking during the past 30 days preceding the survey, and the hours using computer daily both in weekdays and in weekend. The level of resistance to peer influence and risky decision-making were assessed by Resistance to peer influence scale (RPIS) and Youth decision-making questionnaire (YDMQ). Logistic regression was used to explore possible interrelationships among resistance to peer influence, risky decision-making and health risk behaviors among young adolescents.</p><p><b>RESULTS</b>A total of 1985 questionnaires were valid, including 1001(50.4%) boys and 984 (49.6%) girls. About 27.1% (537/1985) junior middle school students reported having health risk behaviors, boys' (30.7%, 307/1001) was higher than girls' (23.4%, 230/984) with significant gender difference (P < 0.05). The prevalence of smoking, drinking during the past 30 days before the survey and using computer over 3 hours daily in weekdays and in weekend were 5.1% (102/1985), 14.3% (284/1985), 3.5% (70/1985) and 13.7% (272/1985), respectively. The rate of drinking, using computer over 3 hours daily in weekdays and in weekend were higher in males (16.4% (164/1001), 4.5% (45/1001), 16.2% (162/1001)) than those in females (12.2% (120/984), 2.5% (25/984), 11.2% (110/984)) (P < 0.05). The scores of RPIS and YDMQ of the two cities adolescents were 2.82 ± 0.39 and 1.68 ± 0.62. The students reported smoking, drinking during the past 30 days before the survey and using computer over 3 hours daily in weekend gained lower RPIS scores (2.43 ± 0.40, 2.61 ± 0.41, 2.77 ± 0.40) than their counterparts who didn't report these kind of health risk behaviors (2.84 ± 0.38, 2.85 ± 0.38, 2.82 ± 0.39)(P < 0.05). And those reported smoking, drinking during the past 30 days before the survey and using computer over 3 hours daily in weekdays and in weekend gained higher YDMQ scores (2.38 ± 0.66, 2.06 ± 0.66, 1.97 ± 0.72, 1.84 ± 0.64, respectively) than their counterparts who didn't report these kind of health risk behaviors (1.64 ± 0.38, 1.61 ± 0.58, 1.67 ± 0.61, 1.65 ± 0.61, respectively) (P < 0.05). After adjusting gender, area, parental education degree, self-reported family economic condition, multi-variant logistic regression analysis indicated that the low and middle level of resistance to peer influence (low and middle level vs high level, had odds ratios of 2.97 (1.96 - 4.50) and 1.51 (1.05 - 2.16)), and also the middle and high level of risky decision-making (middle and high level vs low level, had odds ratios of 1.62 (1.19 - 2.22) and 3.43 (2.39 - 4.90)) were all the risk factors of adolescent health risk behaviors.</p><p><b>CONCLUSION</b>Adolescents with poor ability of resistance to peer pressure and high risky decision-making were both the risk factors of adolescent health risk behaviors.</p>

Sonohysterography-Guided Biopsy of Focal Endometrial Lesions: Value of Four-dimensional Ultrasonography

PURPOSE: To assess the usefulness of four-dimensional (4D) ultrasonographic guidance in sonohysterographyguided biopsy of focal endometrial lesions. MATERIALS AND METHODS: Endometrial biopsies were performed prospectively under 4D ultrasound guidance in 24 consecutive patients with focal endometrial lesions detected on baseline sonohysterography. A single slice view in three orthogonal planes, a sagittal surface-rendered image, and multislice views in the sagittal plane were used for real-time guidance during the procedure. We evaluated feasibility based on the technical success rates and the number of "diagnostic" specimens obtained for histological diagnosis, and we correlated the biopsy results with the pathological diagnosis determined through the surgical procedure. RESULTS: Four-dimensional sonohysterography-guided biopsy was successfully performed in 21 (87.5%) of 24 patients without any significant complication. The biopsy specimens were diagnostic in 19 (90.5%) of 21 patients. Thirteen of 19 patients (68.4%) patients underwent surgery, and the diagnoses obtained using cytology correlated well with the pathology. CONCLUSION: Four-dimensional ultrasonography-guided biopsy is technically feasible and may be useful in the diagnosis of focal endometrial lesions.

Characteristics of Non-typhoidal Salmonella Isolates from Human and Broiler-chickens in Southwestern Seoul, Korea

Non-typhoidal Salmonella (NTS) is an important commensal microorganism. The purpose of this study was to determine the epidemiological relation between NTS isolates from livestock and NTS isolates from human by analyzing antimicrobial susceptibilities and performing molecular typing. We determined the serotypes of 36 human clinical isolates and 64 livestock isolates, performed antimicrobial susceptibility testing against 8 antibiotics, and determined the molecular types of isolated NTS spp. by pulsed field gel electrophoresis (PFGE). In human isolates, S. enteritidis was the most common serotype (17 isolates; 47.2%) and S. typhimurium the second most (8 isolates; 22.2%). In livestock isolates, S. typhimurium was the most common serotype (15 isolates; 23.44%), and S. enteritidis was the second most (14 isolates; 21.88%). Ampicillin and tetracycline resistance were 50% (32/64 isolates) each among broiler-chicken NTS isolates. No human or livestock NTS isolates showed resistance to ciprofloxacin, TMP-SMX, or ceftriaxone. However, 19.4% (7/36) and 46.8% (30/64) of the human and livestock NTS isolates were resistant to nalidixic acid (MIC > or =16 mg/mL), respectively. The presence of the three identical PFGE molecular types from human and broiler-chicken NTS isolates suggests the possibility of transmission from livestock to humans.

Sonohysterography-Guided Biopsy of Focal Endometrial Abnormalities: Technical Feasibility and Diagnostic Accuracy

PURPOSE: To assess the feasibility and diagnostic accuracy of a sononohysterography-guided biopsy in an evaluation of focal endometrial lesions. MATERIALS AND METHODS: Sixty-five consecutive patients with focal endometrial lesions detected on baseline sonohysterography were enrolled prospectively. The biopsy was performed under real-time sonohysterography guidance, using a 3.1 mm Pipelle endometrial sampler as the primary biopsy device. The feasibility was evaluated from the technical success rates and the number of "diagnostic" specimen for the histological diagnosis. The diagnostic accuracy was assessed by comparing the biopsy results with the final pathological diagnosis obtained by the surgical procedure. RESULTS: Sonohysterography-guided biopsy was performed successfully in 59(90.8%) out of 65 patients. The reasons for failure in 6 patients were a failure to pass through the cervix (n=3); failure to target a focal lesion (n=2); and inadequate uterine distension (n=1). The biopsy specimen was "diagnostic" in 49 (83.1%) out of 50 patients, and "non-diagnostic" in 10 patients with insufficient tissue (n=6) and indeterminate cellular features for a histological diagnosis (n=4). The cytology results of the sonohysterographically-guided biopsy correlated well with the pathological diagnosis in 35 (92.1%) out of 38 patients who underwent subsequent surgical procedures. CONCLUSION: Sonohysterography-guided biopsy is technically feasible and can be an accurate method for diagnosing focal endometrial lesions. It could be considered to be a reliable office triage as an alternative to hysteroscopic biopsy in patients with focal endometrial abnormalities.

The Diagnostic Accuracy of Multidetector Row CT for Evaluating the Axillary Lymph Nodes in Patients with Breast Cancer

PURPOSE: We investigated the CT (computed tomography) findings of metastatic lymph nodes (LNs), and we analyzed the diagnostic performance of multidetector row CT (MDCT) for detecting axillary LN metastases in patients with breast cancer. MATERIALS AND METHODS: We investigated 59 patients who preoperatively underwent chest MDCT, and they underwent sentinel LN biopsy or whole axillary LN dissection. We analyzed the morphologic features, the degree of enhancement and the delayed enhancement pattern. We classified the patients into the non-metastatic LN group and the metastatic LN group, and we calculated the diagnostic performance of MDCT for detecting metastatic LNs. RESULTS: When both the morphologic and quantitative criteria were consistent, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 58.1%, 100%, 100% and 68.3%, respectively, and MDCT accurately detected metastatic LNs in 2 patients that were false negative on sentinel LN biopsy. When the morphologic and quantitative criteria were consistent, the sensitivity, specificity, PPV and NPV were 87.1%, 53.6%, 67.5% and 78.9%, respectively. However, MDCT could not detect metastatic LNs, including two micrometastases (a total of 8 micrometastases) that were in each of four patients. CONCLUSION: MDCT can be used to perform the morphology and quantitative analysis of axillary LNs, and this modality has excellent specificity and a PPV for detecting metastatic LNs when the both of the diagnostic criteria are consistent.

Analysis of the seroprevalence of bovine paratuberculosis and the application of modified absorbed ELISA to field sample testing in Korea

Paratuberculosis (PTB) is a major disease problem worldwide, and causes major economic losses in the dairy industry. Although PTB has been reported in Korea, no studies have been conducted to determine its prevalence and no program has been developed to control the disease. In this study, the sera of beef (n = 1,056) and dairy cattle (n = 1,105) from all provinces in Korea were tested to determine the prevalence of PTB using two different ELISA: an 'in house' modified absorbed ELISA (P-ELISA) based on sonicated antigen from Mycobacterium avium subsp. paratuberculosis ATCC 19698, and a commercial ELISA (C-ELISA). Receiver operating characteristic analysis was used to determine the cutoff point for P-ELISA. Based on C-ELISA results, the area under the curve for P-ELISA was 0.913 (95% CI, 0.883 to 0.943). Using a cutoff point of 0.100, P-ELISA showed a sensitivity of 62.0% and a specificity of 93.7%. The kappa value and the percent agreement between the two ELISAs were 0.322 and 92.5%, respectively. Both ELISAs showed a significant correlation between age and seropositivity (p < 0.01). According to C-ELISA, 71 of 2,161 sera (3.3%, 95 CI, 2.6% to 4.1%) were test-positive. The national true prevalence of PTB was estimated to be 7.1%. The findings suggest that a control program should be implemented to limit the spread of this disease, and that P-ELISA could be used as a screening test that produces results similar to C-ELISA.

Isolation and identification of Escherichia coli O157:H7 using different detection methods and molecular determination by multiplex PCR and RAPD

Escherichia coli O157:H7 is recognized as a significant food-borne pathogen, so rapid identification is important for food hygiene management and prompt epidemiological investigations. The limited prevalence data on Shiga toxin-producing E. coli (STEC) and E. coli O157:H7 in foods and animals in Korea made an assessment of the risks difficult, and the options for management and control unclear. The prevalence of the organisms was examined by newly developed kit-E. coli O157:H7 Rapid kit. For the isolation of E. coli O157:H7, conventional culture, immunomagnetic separation, and E. coli O157:H7 Rapid kit were applied, and multiplex PCR and randomly amplified polymorphic DNA (RAPD) were performed for the molecular determination. There was high molecular relatedness among 11 Korean isolates and 17 U.S. strains at 63% level. Additionally, distinct differentiation between pig and cattle isolates was determined. It implied that RAPD had a capacity to distinguish strains with different sources, however it could not discriminate among isolates according to their differences in the degree of virulence. In antimicrobial susceptibility tests, 45.5% of isolates showed antibiotic resistance to two or more antibiotics. Unlike the isolates from other countries, domestic isolates of E. coli O157:H7 was mainly resistant to ampicillin and tetracylines. In summary, the application of E. coli O157:H7 Rapid kit may be useful to detect E. coli O157:H7 due to its sensitivity and convenience. Moreover, combinational analysis of multiplex PCR together with RAPD can aid to survey the characteristics of isolates.

Clinical study on the severe hepatitis with nosocomial fungal infections and risk factors / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the nosocomial fungal infections in the patient with severe hepatitis and analyze of risk factor.</p><p><b>METHODS</b>All 115 severe hepatitis with fungal infections inpatients was studied prospectively.</p><p><b>RESULTS</b>We identified 115 cases with fungal infections, the mean age of patients was 37.2+/-21.5 years, male: 49 cases, female 66 cases. Infection of abdominal cavity accounted for 40.9%, infectious rate in respiratory tract and digestive tract were 26.9%, 21.8%, respectively. Candida albicans accounted for 67.6%. Use of broad-spectrum antibiotic and corticosteroids, neutropenia, severity of liver disease, improper medical manipulations as significant risk factors for fungal infection. Death rate of study group and control group was 59.1%, 34.8%, respectively (x2=36.0). In multivariate analysis, neutropenia, disseminated infection and severity of liver diseases were independent prognostic factors.</p><p><b>CONCLUSION</b>Identification of risk factors and predictors of a poor outcome in patients with severe hepatitis with fungal infections, it suggested that implications in prophylaxis of fungal infection, early diagnosis and appropriate therapy would be important for these patients.</p>

The Usefulness of MRI in Evaluating the Shoulder Injury / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to evaluate the accuracy and the usefulness of MRI in patients with shoulder injuries. MATERIALS AND METHODS: The sensitivity and the accuracy of MRI in the diagnosis of various lesion were evaluated in 20 patients with shoulder injuries. RESULTS: MRI enabled Bankart lesions and SLAP lesions to be accurately predicted with 100% sensitivity and 90% accuracy in both. However, for types of SLAP lesions, the sensitivity and the accuracy were 60% and 70%, respectively, and for full-thickness or partial-thickness tear of rotator cuff, the sensitivity and the accuracy were 75% in both. MRI was also effective at predicting rotator cuff tear with 100% sensitivity and 95% accuracy. Sensitivity and accuracy for the diagnosis of Hill-Sachs lesion were 91.7% and 90%, respectively. For all lesions except Hill-Sachs lesion, the negative prediction value was higher than the positive prediction value, which means MRI overestimated the lesions. CONCLUSION: MRI was accurate and useful in the prediction of prediction of rotator cuff tear, labral tear and Hill-Sachs lesions. However, for the identification of full-thickness or partial-thickness tear of rotator cuff, and types of SLAP lesions, it was less accurate and less useful.

Hemodynamic Responses and Oxygen Availability in Unanesthetized Dogs during Apnea / 대한마취과학회지

BACKGROUND: This study examined hemodynamic variables, oxygen delivery, extraction, and consumption in response to acute progressive hypoxia and hypercarbia in the setting of apnea. METHODS: Apnea was induced in 9 healthy mongrel dogs by disconnecting animals from mechanical ventilation of 30 minutes with pure oxygen. Hemodynamic variables, oxygen transport, extraction, and consumption were rapidly and repeatedly measured using pulmonary arterial and arterial catheters until cardiac output was undetectable. RESULTS: The baseline PaO2, PaCO2, pH, base excess were 318 +/- 137 mm Hg, 36 +/- 3.5 mm Hg, 7.30 +/- 0.06, 6.81 +/- 2.65 mmol/l respectively. Hypercarbia and hypoxemia (76 +/- 33 mm Hg) was first noted at 1 and 4 minute respectively. Base excess was not changed. Indices of preload (PCWP and CVP) were increased early in the time course (p<0.05). In contrast, indices of afterload (SVR) increased later, just before cardiac decompensation began (p<0.05). No significant reduction of cardiac output, oxygen delivery, extraction, and consumption was detected just until abrupt cardiac decompensation started, 5 minute. CONCLUSIONS: These data suggest that the early increase in preload was primarily due to hypercarbia whereas the late increase in afterload was due to hypoxemia, but the main cause of acute cardiac decompensation was a critical decrease in arterial oxygen tension with some contribution of increased preload and afterload.

The Appropriate Inflow Rates of Oxygen and Nitrous Oxide in Adult General Anesthesia / 대한마취과학회지

BACKGROUND: During adult general anesthesia, we used 3~5 L/min of fresh gas flow(FGF) but low FGF are employed, the amount of anesthetic consumption and air contamination can be reduced. The aim of this study was to determine the minimal appropriate inflow rate of oxygen and nitrous oxide during semiclosed circle technique. METHODS: We selected 40 patients, ASA group 1 or 2, scheduled for elective, nonabdominal surgery under general anesthesia with semiclosed circle system. Anesthesia was maintained with 50% oxygen, nitrous oxide and enflurane, controlled ventilation was used; rate of 10/min, tidal volume of 10 ml/kg. After induction and vital signs stabilized, FGF was changed to 4 L, 3 L, 2 L and 1L/min at interval of 30 minutes. We observed mean airway pressure and arterial blood gas tensions. RESULTS: The changes of mean airway pressure did not correlated with fresh gas inflow rate. In arterial blood gas analysis, PaO2 showed a decreasing tendency significantly according to decreasing fresh gas inflow rate(p<0.01) but there were no clinical hypoxemia in all patients. There were no significant changes in pH, PaCO2 and base excess. CONCLUSIONS: We consider that FGF of 1~2 L/min is appropriate during adult general anesthesia because of economic and ecological advantages. Also, we consider low flow technique with below 1L/min can be used safely and effectively under proper gas monitoring such as oxygen analyzer, capnometer.