O-linked N-acetylglucosamine affects mitochondrial homeostasis by regulating Parkin-dependent mitophagy in hyperoxia-injured alveolar type II cells injury.

BACKGROUND: The level of linked N-acetylglucosamine (O-GlcNAc) has been proved to be a sensor of cell state, but its relationship with hyperoxia-induced alveolar type 2 epithelial cells injure and bronchopulmonary dysplasia (BPD) has not been clarified. In this study, we evaluated if these effects ultimately led to functional damage in hyperoxia-induced alveolar cells. METHODS: We treated RLE-6TN cells at 85% hyperoxia for 0, 24 and 48 h with Thiamet G (TG), an OGA inhibitor; OSMI-1 (OS), an OGT inhibitor; or with UDP-GlcNAc, which is involved in synthesis of O-GlcNAc as a donor. The metabolic rerouting, cell viability and apoptosis resulting from the changes in O-GlcNAc glycosyltransferase levels were evaluated in RLE-6TN cells after hyperoxia exposure. We constructed rat Park2 overexpression and knockdown plasmmids for in vitro verification and Co-immunoprecipitation corroborated the binding of Parkin and O-GlcNAc. Finally, we assessed morphological detection in neonatal BPD rats with TG and OS treatment. RESULTS: We found a decrease in O-GlcNAc content and levels of its metabolic enzymes in RLE-6TN cells under hyperoxia. However, the inhibition of OGT function with OSMI-1 ameliorated hyperoxia-induced lung epithelial cell injury, enhanced cell metabolism and viability, reduced apoptosis, and accelerated the cell proliferation. Mitochondrial homeostasis was affected by O-GlcNAc and regulated Parkin. CONCLUSION: The results revealed that the decreased O-GlcNAc levels and increased O-GlcNAcylation of Parkin might cause hyperoxia-induced alveolar type II cells injurys.

Protective Effects of 18ß-Glycyrrhetinic Acid on Neonatal Rats with Hyperoxia Exposure.

Bronchopulmonary dysplasia (BPD) is a common devastating pulmonary complication in preterm infants. Supplemental oxygen is a lifesaving therapeutic measure used for premature infants with pulmonary insufficiency. However, oxygen toxicity is a significant trigger for BPD. Oxidative stress disrupts lung development, accompanied by increased pro-inflammatory cytokines and chemokines expression and immune cells infiltration in lung tissue. Licorice, a typical traditional herbal medicine, is commonly used in the medicine and food industries. 18ß-Glycyrrhetinic acid (18ß-GA), a primary active ingredient of licorice, has powerful anti-oxidative and anti-inflammatory effects. This study aimed to determine whether 18ß-GA has a protective effect on neonatal rats with hyperoxia exposure. Newborn Sprague-Dawley rats were kept in either 21% (normoxia) or 80% O2 (hyperoxia) continuously from postnatal day (PN) 1 to 14. 18ß-GA was injected intragastrically at 50 or 100 mg/kg body weight once a day from PN 1 to 14. We examined the body weight and alveolar development and measured ROS level and the markers of pulmonary inflammation. Mature-IL-1ß and NF-κB pathway proteins, and the NLRP3 inflammasome, were assessed; concurrently, caspase-1 activity was measured. Our results indicated that hyperoxia resulted in alveolar simplification and decreased bodyweight of neonatal rats. Hyperoxia increased ROS level and pulmonary inflammation and activated NF-κB and the NLRP3 inflammasome. 18ß-GA treatment inhibited the activation of NF-κB and the NLRP3 inflammasome, decreased ROS level and pulmonary inflammation, improved alveolar development, and increased the bodyweight of neonatal rats with hyperoxia exposure. Our study demonstrates that 18ß-GA has a protective effect on neonatal rats with hyperoxia exposure.

The Specific Connexin 43-Inhibiting Peptide Gap26 Improved Alveolar Development of Neonatal Rats With Hyperoxia Exposure.

Bronchopulmonary dysplasia (BPD) is a common devastating pulmonary complication in preterm infants. Alveolar maldevelopment is the crucial pathological change of BPD highly associated with oxidative stress-mediated excessive apoptosis. Cellular injury can be propagated and amplified by gap junction (GJ)-mediated intercellular communication. Connexin 43 (Cx43) is the most ubiquitous and critical GJ protein. Gap26 is a specific Cx43 mimic peptide, playing as a Cx43-GJ inhibitor. We hypothesized that Cx43-GJ was involved in alveolar maldevelopment of BPD via amplifying oxidative stress signaling and inducing excessive apoptosis. Neonatal Sprague Dawley rats were kept in either normoxia (21% O2) or hyperoxia (85% O2) continuously from postnatal day (PN) 1 to 14 in the presence or absence of Gap26. Moreover, RLE-6TN cells (type II alveolar epithelial cells of rats) were cultured in vitro under normoxia (21% O2) or hyperoxia (85% O2). RLE-6TN cells were treated by N-acetyl cysteine (NAC) (a kind of reactive oxygen species (ROS) scavenger) or Gap26. Morphological properties of lung tissue are detected. Markers associated with Cx43 expression, ROS production, the activity of the ASK1-JNK/p38 signaling pathway, and apoptotic level are detected in vivo and in vitro, respectively. In vitro, the ability of GJ-mediated intercellular communication was examined by dye-coupling assay. In vitro, our results demonstrated ROS increased Cx43 expression and GJ-mediated intercellular communication and Gap26 treatment decreased ROS production, inhibited ASK1-JNK/p38 signaling, and decreased apoptosis. In vivo, we found that hyperoxia exposure resulted in increased ROS production and Cx43 expression, activated ASK1-JNK/p38 signaling, and induced excessive apoptosis. However, Gap26 treatment reversed these changes, thus improving alveolar development in neonatal rats with hyperoxia exposure. In summary, oxidative stress increased Cx43 expression and Cx43-GJ-mediated intercellular communication. And Cx43-GJ-mediated intercellular communication amplified oxidative stress signaling, inducing excessive apoptosis via the ASK1-JNK/p38 signaling pathway. The specific connexin 43-inhibiting peptide Gap26 was a novel therapeutic strategy to improve the alveolar development of BPD.

Effects of Hyperoxia on Mitochondrial Homeostasis: Are Mitochondria the Hub for Bronchopulmonary Dysplasia?

Mitochondria are involved in energy metabolism and redox reactions in the cell. Emerging data indicate that mitochondria play an essential role in physiological and pathological processes of neonatal lung development. Mitochondrial damage due to exposure to high concentrations of oxygen is an indeed important factor for simplification of lung structure and development of bronchopulmonary dysplasia (BPD), as reported in humans and rodent models. Here, we comprehensively review research that have determined the effects of oxygen environment on alveolar development and morphology, summarize changes in mitochondria under high oxygen concentrations, and discuss several mitochondrial mechanisms that may affect cell plasticity and their effects on BPD. Thus, the pathophysiological effects of mitochondria may provide insights into targeted mitochondrial and BPD therapy.

Involvement of ROS in intestinal epithelial cell ASK1 and P38 activation and expression in hyperoxia / 国际儿科学杂志

Objective:Hyperoxia is a necessary therapy in some neonatal diseases, and long-term therapeutic hyperoxia may induce severe damaging effects on intestinal epithelial cells.The aim of this study was to investigate whether hyperoxia could promote the expression of ASK1 and P38 in intestinal epithelial cells through ROS.Methods:The human colon adenocarcinoma cell line Caco-2 cells were treated with different concentrations of H 2O 2(100 μmol/L, 200 μmol/L and 400 μmol/L)and 85% oxygen in vitro.The expression of ASK1 was detected by immunofluorescence, and the expression of P38 and p-P38 were detected by Western Blot and Real-time PCR. Results:With the increase of H 2O 2 concentration, the fluorescence intensity of ASK1 increased.The fluorescence intensity of ASK1 in the hyperoxia group was significantly stronger than that of the control group and the H 2O 2 groups.With the increase of H 2O 2 concentration(100 μmol/L、200 μmol/L、400 μmol/L), the expression of P38 protein(0.21±0.02, 0.28±0.13, 0.44±0.07)and p-P38 protein(0.09±0.02, 0.19±0.03, 0.37±0.07)gradually increased.The expression of P38 mRNA in 200 μmol/L and 400 μmol/L H 2O 2 groups(4.03±0.68、3.94±0.71)was significantly higher than that in 100 μmol/L H 2O 2 group(3.05±0.47)( P<0.01). The expressions of P38 protein, p-P38 protein and P38 mRNA in the hyperoxia group were significantly higher than those in the H 2O 2 group( P<0.01). Compared with the control group, the expressions of P38 protein, p-P38 protein and p38 mRNA in the hyperoxia group and H 2O 2 groups increased significantly( P<0.01). Conclusion:The expression of ASK1 and P38 in intestinal epithelial cells increased significantly under hyperoxia, which indicated that hyperoxia might activate ASK1 and thereby regulate the expression of downstream P38 through ROS, resulting in intestinal epithelial cells damage.

Differential mRNA expression in C57BL/6 mice with bleomycin-induced pulmonary fibrosis and its association with LncRNA co-expression network / 南方医科大学学报

OBJECTIVE@#To study the changes in mRNA and long non-coding RNA (lncRNA) expression profiles in a mouse model of bleomycin-induced lung fibrosis and identify lung fibrosis-related mRNA for coding-noncoding coexpression (CNC) bioinformatics analysis of the differential lncRNAs.@*METHODS@#Lung fibrosis was induced by intratracheal injection of bleomycin in 10 C57BL/6 mice and another 10 mice with intratracheal injection of saline served as the control group. Lung tissues were harvested from the mice at 14 days after the injections and lung fibrosis was assessed using Masson and HE staining. LncRNA chip technology was used to screen the differentially expressed mRNAs and lncRNAs in mice with lung fibrosis, and GO and KEGG pathway analyses of the differential mRNAs were performed using NCBI database and UCSC database to identify possible fibrosis-related mRNAs, which were validated by qRT-PCR to construct a coding and non-coding co- expression network with the differential lncRNAs.@*RESULTS@#Compared with the control mice, the mice with intratracheal injection of bleomycin showed obvious lung fibrosis. The results of gene chip analysis showed that 127 mRNAs were upregulated and 184 mRNAs were down-regulated in the model group as compared with the control group. GO and pathway analysis suggested that the differentially expressed genes participated mainly in immune response, cell differentiation, and cytoskeletons; the involved signal pathways were associated mainly with cytokine and cytokine receptor interaction and chemokine signal transduction. Bioinformatics analysis identified a significant coexpression network between the fibrosisrelated mRNA and the differentially expressed lncRNA.@*CONCLUSIONS@#In mice with lung fibrosis, the differential expressions of fibrosis-related mRNAs in the lung tissues are closely correlated with the co- expressions of a large number of differential lncRNAs, which points to a new direction for investigation of the pathogenesis of pulmonary fibrosis.

Sensing volume of tissue dielectric property measurement with open-ended coaxial probe / 南方医科大学学报

OBJECTIVE@#To investigate the sensing volume of open-ended coaxial probe technique for measurement of dielectric characteristics.@*METHODS@#A measurement model combining macro- measurement device with a layer model of dielectric properties parameters was established for evaluating the sensing volume of open-ended coaxial probe technique. We defined sensing depth and sensing diameter to describe the distance that could be detected in vertical and horizontal direction. Using a variety of materials with different dielectric properties (Teflon, deionized water, ethanol, and gradient concentration sodium chloride solution), a layered model of dielectric properties differentiation was established. The total combined uncertainties (TCU) were calculated for different output power, and the output power was controlled to increase from -50 dBm to 15 dBm to calibrate the error range of the dielectric properties measurement system. The optimal output power range was determined based on the results of TCU test. In sensing volume measurement experiment, we set the control groups based on measurement parameters that potentially affect the sensing volume including output power (-10, -5, 0, 3, 6, and 9 dBm), frequency (1-500 MHz), Teflon, deionized water, and ethanol to form a dielectric constant difference between high and low contrast groups. Different concentrations of sodium chloride solution and Teflon were used to generate a conductivity difference between high and low contrast groups. These groups were tested in the sensing depth and sensing diameter measurement experiments.@*RESULTS@#The result of TCU test indicated that accurate and stable measurement results could be obtained when the output power was greater or equal to-10 dBm (TCU < 2%). Sensing volume measurement experiment revealed a positive correlation between the sensing depth and output power ( < 0.05). As the measured power increased, the sensing depth gradually increased in deionized water and ethanol, and the difference reached 70 μm. The sensing depth was negatively correlated frequency ( < 0.05). As the concentration of sodium chloride solution increased, the corresponding sensing depth gradually decreased, with a difference reaching 270 μm. The sensing depth of high dielectric materials was greater than that pf low dielectric materials. The results of sensing diameter measurement were not obviously affected by the measurement parameters, and the sensing diameter was stable in a fixed range (1.0 to 1.8 mm) between the diameter of the inner conductor and the diameter of the insulation layer, and was less than the diameter of the probe.@*CONCLUSIONS@#The sensing volume of open-ended coaxial probe technique is affected by measurement parameters and dielectric properties of materials, which significantly affect the sensing depth.

Discrimination of lung cancer and adjacent normal tissues based on permittivity by optimized probabilistic neural network / 南方医科大学学报

OBJECTIVE@#To propose a probabilistic neural network classification method optimized by simulated annealing algorithm (SA-PNN) to discriminate lung cancer and adjacent normal tissues based on permittivity.@*METHODS@#The permittivity of lung tumors and the adjacent normal tissues was measured by an open-ended coaxial probe, and the statistical dependency (SD) algorithm was used for frequency screening.The permittivity associated with the selected frequency points was taken as the characteristic variable, and SA-PNN was used to discriminate lung cancer and the adjacent normal tissues.@*RESULTS@#Three frequency points, namely 984 MHz, 2724 MHz and 2723 MHz, were selected by SD algorithm.SA-PNN was used to discriminate 200 samples with the permittivity at the 3 frequency points as the characteristic variable.After 10-fold cross-validation, the final discrimination accuracy was 92.50%, the sensitivity was 90.65%, and the specificity was 94.62%.@*CONCLUSIONS@#Compared with the traditional probabilistic neural network, BP neural network, RBF neural network and the classification discriminant analysis function (Classify) in MATLAB, the proposed SA-PNN has higher accuracy, sensitivity and specificity for discriminating lung cancer and the adjacent normal tissues based on permittivity.

Sensing volume of tissue dielectric property measurement with open-ended coaxial probe / 浙江大学学报·医学版

OBJECTIVE@#To investigate the sensing volume of open-ended coaxial probe technique for measurement of dielectric characteristics.@*METHODS@#A measurement model combining macro- measurement device with a layer model of dielectric properties parameters was established for evaluating the sensing volume of open-ended coaxial probe technique. We defined sensing depth and sensing diameter to describe the distance that could be detected in vertical and horizontal direction. Using a variety of materials with different dielectric properties (Teflon, deionized water, ethanol, and gradient concentration sodium chloride solution), a layered model of dielectric properties differentiation was established. The total combined uncertainties (TCU) were calculated for different output power, and the output power was controlled to increase from -50 dBm to 15 dBm to calibrate the error range of the dielectric properties measurement system. The optimal output power range was determined based on the results of TCU test. In sensing volume measurement experiment, we set the control groups based on measurement parameters that potentially affect the sensing volume including output power (-10, -5, 0, 3, 6, and 9 dBm), frequency (1-500 MHz), Teflon, deionized water, and ethanol to form a dielectric constant difference between high and low contrast groups. Different concentrations of sodium chloride solution and Teflon were used to generate a conductivity difference between high and low contrast groups. These groups were tested in the sensing depth and sensing diameter measurement experiments.@*RESULTS@#The result of TCU test indicated that accurate and stable measurement results could be obtained when the output power was greater or equal to-10 dBm (TCU < 2%). Sensing volume measurement experiment revealed a positive correlation between the sensing depth and output power ( < 0.05). As the measured power increased, the sensing depth gradually increased in deionized water and ethanol, and the difference reached 70 μm. The sensing depth was negatively correlated frequency ( < 0.05). As the concentration of sodium chloride solution increased, the corresponding sensing depth gradually decreased, with a difference reaching 270 μm. The sensing depth of high dielectric materials was greater than that pf low dielectric materials. The results of sensing diameter measurement were not obviously affected by the measurement parameters, and the sensing diameter was stable in a fixed range (1.0 to 1.8 mm) between the diameter of the inner conductor and the diameter of the insulation layer, and was less than the diameter of the probe.@*CONCLUSIONS@#The sensing volume of open-ended coaxial probe technique is affected by measurement parameters and dielectric properties of materials, which significantly affect the sensing depth.

Design of modulating intermediate frequency electrotherapy system based on microcontroller unit / 生物医学工程学杂志

This article is devoted to the design of a system for modulating intermediate frequency electrotherapy waveform output. Prescriptions with different output waveform combinations were produced using microcontroller unit (MCU). The rich output waveforms effectively improve tolerance of human adaptability and achieve a therapeutic effect.

A Modified Kernel-based Fuzzy C-Means Algorithm For Images Segmentation / 医疗卫生装备

Objective To segment brain magnetic resonance (MR) images corrupted by noises. Methods We presented a novel Fuzzy C-Means (FCM) algorithm for image segmentation. The algorithm was by modifying the objective function in the conventional FCM. Firstly,by using kernel method,the original Euclidean distance in the FCM was replaced by a kernel-induced distance. Then,a spatial penalty term was added to the objective function to compensate the influence of the neighboring pixels on the center pixel. Results Segmentation results on a four-class synthetic image corrupted by salt & pepper noise shows that the new algorithm is less speckled and smoother. The new algorithm is applied to simulation MR images and is shown to have less misclassification rate than the other FCM-based methods. Conclusion The results of experiments show that the proposed algorithm is more robust to noise than other FCM-based methods.

Development of Temperature Control System for Hyperthermia Based on PWM / 医疗卫生装备

Objective To develop a hyperthermia temperature control system for the treatment of pelvic inflammatory disease. Methods Temperature was controlled by using PWM method based on a single chip computer. The system was heated by using heating wire. In the whole cycle of T, the heating wire's work time was divided into three different stages according to different temperature of system: in the lower temperature, the duty cycle of the heating wire's work time was 100%; when the system temperature entered to a certain stage, a control variable was obtained through the PID algorithm which was used to compare the difference between the current temperature and the temperature requirements. The control variable determined the duty cycle of the heating wire's work time: the more close to the temperature required for the temperature of system, the duty cycle of the heating wire's work time was more close to 0; if the temperature exceeded a predetermined value, then the heating wire would not heat in the whole cycle. Results The accuracy of the temperature control system was ?0.2 ℃, the overshoot of the temperature control system was ?0.3 ℃, and the response time of the temperature control system was 500 seconds. Conclusion The temperature control method has high precision, small overshoot, and the right response time, which can meet the requirements of constant temperature of hyperthermia treatment. Besides, it is simple and cheap.

Development of a portable low-frequency electronic pulse analgesia apparatus based on single-chip microprocessor / 医疗卫生装备

In this paper, a novel portable low-frequency electronic pulse analgesia apparatus is introduced, which is based on a novel single-chip microprocessor, switching power supply without transformer and OTL power output amplifier. Through this apparatus, multi-group low-frequency electronic pulses can be produced to simulate the same effects as acupuncture. This apparatus has an observably curative effect for dysmenorrhea.

Nerve stimulator with single-phase constant-current pulse / 医疗卫生装备

M PU employed as control center,the nerve stimulator can produce different stimul ation modes easily.The high-quality constant-current pulse and the safety of th e patient are ensured through two-steps current stabilizer,pulse width monitor and the float to ground.Both needle electrode and surface electrode can be used to achieve supramaximal stimulation.

Design of Electric Stimulator of Cell Culture / 医疗卫生装备

Objective To design an instrument that can provide a series of pulse to stimulate cell by means of external electric field, the structure and function of organism can retrieve. Methods AVR MCU, produced by America ATMEL Co., is used as the core of the system. The program has been developed to adjust three pulse's parameters, including amplitude, frequency and pulse duration. The cooperation between DAC and OP completes the transformation from monopole pulse to bipolar pulse. The booster PB50 amplifies the current and voltage of the output. Results The Stimulator can provide bipolar pulse, amplitude: up to ?40V, frequency: 0.01Hz -10Hz, pulse duration: 0.4ms -24ms. Conclusion Cooperating with special electrode board, the instrument can provide effective electric field for cell simulating. At present the instrument has been used in the research of the endothelial progenitor cell.

Study on Experimental Platform Construction of BME Experimental Teaching Demonstration Center / 医疗卫生装备

According to the thoughts of experimental platform construction of the BME experimental teaching demonstration center,the education and institution construction relevant to concrete operating steps and methods are carried on.The engineering experimental platform featuring "Multiple-structure,Multiple-specialty,Integration,Open-type" are substantiated and perfected.A batch of advanced instruments for experimental teaching are purchased.The methods and measures for experimental teaching are improved.The scientific research is permeated into the student's experimental teaching for cultivation innovative talents.

Development of programming cardiac trigger apparatus and its application to myocardial contrast echocardiography / 医疗卫生装备

This paper introduces a programming cardiac trigger apparatus used for the study of quantitative measurement of myocardial blood flow with myocardial contrast echocardiography.The design of hardware circuit based on MCU and the scheme of software based on Keil C51 are mainly discussed.With stable and reliable working,this apparatus provides a kind of technical support for the study of quantitative measurement of myocardial blood flow with continuous intravenous injection of sonicated microbubbles.

Application of wireless transfer technology to medical instrument development / 医疗卫生装备

In many medical instrumentation systems, there exists a long distance between manipulation platform and host unit. Wireless data transferring between the platform and the host could be a feasible way to set parameters. This paper introduces wireless transmitter and receiver circuit based on encoder chip PT2262 and decoder chip PT22720, and presents some typical applications in medical instrument development.