Application of lung ultrasound in monitoring bronchopulmonary dysplasia and pulmonary arterial pressure in preterm infants.

OBJECTIVE: The aim of this study was to evaluate the application value of lung ultrasound in monitoring bronchopulmonary dysplasia (BPD) and pulmonary artery pressure in premature infants. PATIENTS AND METHODS: A total of 98 preterm infants diagnosed with BPD in the Fourth Hospital in Shijiazhuang were recruited, and their disease severity was classified as mild (n=32), moderate (n=33), or severe BPD (n=33) based on gestational age and oxygen concentration. Lung ultrasonography of the children was performed. The correlation between lung ventilation scores and disease severity was statistically analyzed, and the discrete optimization results were documented. The pulmonary hypertension indexes of the three groups of children were compared. RESULTS: Aberrant alterations of the pleural line were observed in all included children, and the B-line rose as the disease progressed. The duration of invasive ventilation, medication, and hospital stay increased with disease exacerbation (p<0.05). The three groups significantly differed in terms of ultrasound pulmonary ventilation scores and clinical severity (p<0.05). Only mild BDP was identified by lung ultrasound on the first day of birth (T1), and severe BDP was detectable during the first and second week (T2-T3) as well as the third and fourth week (T4-T5). Severe BPD was associated with significantly higher levels of pulmonary hypertension indices vs. mild and moderate BPD (p<0.05). CONCLUSIONS: Pulmonary ultrasonography demonstrates great potential to predict pulmonary hypertension in children and assesses the disease severity. Pulmonary ultrasound allows for dynamical real-time observation of the pulmonary lesions in children with pulmonary hypertension, thereby revealing the severity of pulmonary hypertension in premature children.

A two-dimensional Sb/InS van der Waals heterostructure for electronic and optical related applications.

Stable configurations with excellent optical adsorption are crucial for photovoltaics or photocatalysis. Two-dimensional materials with intrinsic electric fields have been proposed as suitable for electric and optical devices. Here, we have performed DFT calculations on the electronic and optical properties of a bilayer Sb/InS van der Waals heterostructure, which consists of Sb and InS monolayers, by studying the band structures, charge density difference and distribution. Interestingly, the Sb/InS bilayer exhibits typical type-II band alignment character with a direct energy gap of 0.44 eV, and the electrons and holes are separated on different surfaces. Furthermore, applying an external E-field and biaxial strain is proved to be an effective way to modify the energy gap, the same as the electronic and optical properties. These theoretical predictions pave the way for high performance electronic and optical devices based on new two-dimensional van der Waals structures.

[Effect of CASC19 on proliferation, apoptosis and radiation sensitivity of cervical cancer cells by regulating miR-449b-5p expression].

Objective: To investigate the effects of cancer susceptibility candidate gene 19 (CASC19) regulating the expression of microRNA-449b-5p (miR-449b-5p) on the proliferation, apoptosis and radiation sensitivity of cervical cancer cells. Methods: (1) HeLa cells of cervical cancer cell line were cultured. HeLa cells were irradiated with X-ray at different doses (0, 2, 4, 6, 8 Gy, respectively), then the expression level of CASC19 mRNA and miR-449b-5p were detected by real-time quantitative PCR. (2) HeLa cell proliferation, apoptosis, radiation sensitivity (expressed as a survival fraction) and its related protein expression included cyclin D1, cleaved-caspase-3, and histone variant H2AX (γ-H2AX) were examined after different treatment including silencing CASC19 expression, over-expressing miR-449b-5p, down-regulating miR-449b-5p and silencing CASC19 expression. (3) The dual luciferase reporter gene experiment and real-time quantitative PCR technology were used to verify the targeting relationship between CASC19 and miR-449b-5p. Results: (1) With the increase of X-ray irradiation different dose (0, 2, 4, 6, 8 Gy), the expression level of CASC19 mRNA in HeLa cells gradually increased (F=502.681, P=0.000), and the expression level of miR-449b-5p gradually decreased (F=202.936, P=0.000).(2) After silencing CASC19 expression or over-expressing miR-449b-5p, the survival rate of HeLa cells was significantly reduced (P<0.05), the apoptosis rate was significantly increased (P<0.05), the survival fraction was significantly reduced (P<0.05), the expression level of cyclin D1 protein was significantly reduced (P<0.05), and the expression levels of cleaved-caspase-3 and γ-H2AX protein were significantly increased (P<0.05). After down-regulating miR-449b-5p and silencing CASC19 expression, the survival rate of HeLa cells was significantly reduced (P<0.05), the apoptosis rate was significantly increased (P<0.05), the survival fraction was significantly reduced (P<0.05), the expression levels of cyclin D1 and γ-H2AX protein were significantly increased (P<0.05), and the expression level of cleaved-caspase-3 was significantly decreased (P<0.05). (3) Over expression of miR-449b-5p could significantly reduce the luciferase activity of CASC19 wild type (1.00±0.09 versus 0.37±0.05, P<0.01), but there were no significant effect on the luciferase activity of CASC19 mutant type (0.92±0.07 versus 0.94±0.05, P>0.05). After the expression of CASC19 was silenced, the expression level of miR-449b-5p in HeLa cells increased significantly (1.00±0.12 versus 4.84±0.49, P<0.05). After overexpression of CASC19, the expression level of miR-449b-5p in HeLa cells was significantly reduced (1.00±0.09 versus 0.38±0.04, P<0.05). Conclusion: CASC19 in HeLa cells negatively regulates the expression of miR-449b-5p, and down-regulating the expression of miR-449b-5p could partially reverse the effects of silencing CASC19 on HeLa cell proliferation, apoptosis and radiation sensitivity.

[Influence of celastrol on toll-like receptor 4-mediated signaling pathway in the free fatty acids-induced HepG2 cells].

Objective: To investigate the effect and mechanism of celastrol on free fatty acids (FFAs)-induced HepG2 cells. Methods: Cultured human HepG2 cells were transfected with toll-like receptor 4 (TLR4) siRNA, and the interference efficiencies were examined by real-time PCR. HepG2 cells were treated with FFAs and celastrol, and the untreated cells were used as a normal control (NC). Deposition of lipids in the HepG2 cells were visualized by Oil Red O staining. The protein expression of TLR4 and downstream inflammatory mediators [myeloid differentiation factor 88 (MyD88), nuclear factor (NF)-κBp65, interleukin (IL)-1ß and tumor necrosis factor α (TNF-α)] in the HepG2 cells were determined by Western blotting. The significance of the data obtained was evaluated using analysis of variance (ANOVA). Results: Red lipid droplets were extensively deposited in HepG2 cells after 0.5 mmol/L FFAs induction and significantly decreased in the celastrol-treated group. The protein expression of TLR4 and downstream inflammatory mediators (MyD88, NF-κBp65, IL-1ß and TNF-α) in the FFAs-induced HepG2 cells increased significantly compared with those of the NC group (all P<0.05), and were suppressed in TLR4 siRNA-treated and celastrol-treated group (TLR4: 0.69±0.14, 1.63±0.12 vs 2.46±0.23; MyD88: 1.21±0.12, 1.35±0.18 vs 1.62±0.19; NF-κBp65: 1.69±0.14, 1.54±0.36 vs 2.19±0.47; IL-1ß: 1.51±0.16, 1.45±0.38 vs 1.82±0.27; TNF-α: 1.60±0.14, 1.41±0.29 vs 1.88±0.19) (all P<0.01). Co-treatment with TLR4 siRNA and celastrol further reduced the expression of inflammation mediators compared with those of the TLR4 siRNA-treated group (MyD88: 1.09±0.23 vs 1.21±0.12; NF-κBp65: 1.24±0.20 vs 1.69±0.14; IL-1ß: 1.28±0.31 vs 1.51±0.16; TNF-α: 1.10±0.29 vs 1.60±0.14) (all P<0.01). Conclusion: Celastrol exerts its protective effect partly via inhibiting the TLR4-mediated signaling pathways in the steatotic HepG2 cells.

[Horizontal semicircular canalvideo head impulse test in normaladults:normal value and age distribution].

Objective:To study the parameters of video head impulse test (vHIT) for horizontal semicircular canal and explore its application when evaluating angular vestibular-ocular reflex (VOR) in adults.Method:vHIT were applied to 80 adults without prior vertigo or dizziness history.Parameters provided by the software included instantaneous gain(40 ms,60 ms,80 ms),regression gain,asymmetry value,corrective saccades(latency,peak velocity,occurrence rate).Result:The mean horizontal VOR velocity gain of normal subjects was 0.877±0.171,0.944±0.133,0.967±0.130 at 40 ms,60 ms,80 ms respectively.Regression gain of horizontal VOR is 0.944±0.090.The lower limit of normal horizontal VOR velocity gain was 0.73 at 60 ms and 0.80 as regression gain.All velocity gains declined by age,although there were no statistically significant difference(P>0.05).Asymmetry value was 5.60±3.46.Corrective saccades occurred in 28±15 of normal subjects,while latency and peak velocity was (200.87±0.34)ms and (97.7±40.1)°/s.Conclusion:The study found that horizontal VOR instantaneous gain value and regression gain value decreases slightly with age,which should be considered in clinical application.

Management and prevention of chylous leakage after laparoscopic lymphadenectomy.

OBJECTIVE: To investigate the development and management of chylous leakage after laparoscopic retroperitoneal lymphadenectomy. PATIENTS AND METHODS: From July 2006 to September 2013, 13 cases of chylous leakage after the laparoscopic lymphadenectomy (6 cases of renal cell carcinoma, 4 cases of gastric cancer, 2 cases of ovarian cancer, 1 case of endometrial cancer) were studied to analyze the occurrence, development and management of chylous leakage. RESULTS: In 3 cases (2 cases of renal cell carcinoma, 1 case of gastric cancer) massive amount of milky fluid drainage was be seen after the first two days post operation. Dietary intervention, TPN (total parenteral nutrition), somatostatin therapy, maintenance of continuous drainage helped to successfully manage the condition in about 1 month duration. In the remaining 10 cases, chylous leakage appeared after restoring normal diet. Managed with changes in diet and maintenance of unobstructed drainage, they were cured in about 2 weeks after treatment. There was significant reduction in drain output, ultrasonography did not reveal presence of free fluid collection in abdomen, and the patients were in good condition without signs and symptoms of infections. CONCLUSIONS: Chylous leakage is a rare complication of retroperitoneal lymph node dissection. Surgeons should be familiar with laparoscopic techniques, relevant anatomy and be aware of the fact that the effect of CO2 pressure and use of ultrasonic knife to occlude the lymphatic vessel can transiently block the leakage making the surgeon overlook them. Routine placement of indwelling drainage tube, immediate diagnosis, dietary modification, TPN, somatostatin and drainage are the modalities of conservative management.

[Effect of noise on human mental performance].

OBJECTIVE: To investigate the effect of moderate noise on human thinking performance. METHODS: During 2 h of exposure to 85, 90 dB(A), successive calculation, successive subtraction and determining figures according symbol were performed in 24 healthy young male subjects. RESULTS: After l h exposure to noise of 85 dB(A), there were no significant changes in the accurate rate, correct number and total number of successive calculation, but the correct number and total number of successive subtraction decreased significantly as compared with control (P< 0.05). At 30 and 120 min exposure to noise of 90 dB(A), the mean reaction time prolonged, performance of reaction time decrease significantly (P<0.01) in the test of determining figures according symbol as compared with control; its total performance had a tendency of decrease, but was not significant. When the subjects were divided into two group according to their E score of EPQ, significantly different performance of accurate rate and different total performance were demonstrated in the test of determining figures according to symbol at 2 h of exposure under 90 dB(A) noise. The performance of extrovert was higher than that of introvert. CONCLUSION: Moderate noise could affect performance of complex tasks with a higher workload and it had certain relationship with the personality of the subjects.

[Effects of anti-rhTNF alpha monoclonal antibody on oxygen extraction in endotoxemic rabbits].

The effects of anti-rhTNF alpha monoclonal antibody (McAb) on oxygen extraction in endotoxemia rabbits were observed by decreasing total oxygen delivery (DO2) with progressive hypoxia. The result showed that the DO2-VO2 relationship in anti-rhTNF alpha McAb group, like the control group, could be clearly divided into "independent" and "dependent" segment, while the non-correlated antibody group, like the endotoxemic group, never presented any plateau upon breathing the air. Critical oxygen delivery (DO2C) and pooled oxygen extraction rate (ER) in anti-rhTNF alpha McAb group were respectively 10.18 +/- 3.21 ml/(min.kg) and 0.690, not significantly different from those in the control group (10.18 +/- 1.69 and 0.730). The ER in non-correlated antibody group was 0.408, which was significantly lower than that in anti-rhTNF alpha McAb group (P < 0.05), while the plasma TNF alpha concentration was significantly higher (P < 0.01). It was concluded that the monoclonal antibody of recombinant human tumor necrosis factor could block or even reverse the pathologic process of oxygen extraction deficiency caused by endotoxemia.

Development of retinoblastoma in the absence of telomerase activity.

BACKGROUND: The length and stability of telomeres (essential functional structures at the end of eukaryotic chromosomes) have been implicated in the control of cell lifespan. Most somatic cells lack telomerase, the enzyme that synthesizes telomeric DNA, and their telomeres shorten with cell division. Cells immortalized in vitro, on the other hand, express telomerase and maintain their telomeres. Telomerase activity has also been detected in the large majority of tumors from a variety of cancers. These observations have suggested that telomere maintenance is required for unlimited cell proliferation and that telomerase is a marker for cell immortality in vitro and in vivo. PURPOSE: We investigated whether telomerase is activated during the development of retinoblastoma. This is a childhood eye cancer associated with a limited number of mutations in an embryonic tissue and thus likely to develop in cells that have long telomeres. The ease of detection of retinoblastoma makes it possible to screen relatively small tumors before extensive proliferation of the malignant cells. METHODS: We measured telomerase activity in 34 samples of retinoblastoma, four retinoblastoma-derived cell lines, and six cell lines derived from other cancers. Only three of the cell lines from other cancers expressed the retinoblastoma protein. Telomerase activity was assayed by a polymerase chain reaction protocol in extracts prepared from tumors or cell lines. The level of enzyme activity in cell extracts was quantified at several protein concentrations and expressed relative to that in a positive control, after normalization for the amount of protein. Telomere length was measured by Southern blot hybridization of genomic DNA with a telomere-specific probe. Average values of telomere length in telomerase-positive and telomerase-negative tumors and in cell lines were compared by two-sided, two-sample Student's t test. RESULTS: No telomerase activity was detected in 17 (50%) of 34 retinoblastomas. Assays of cell lines derived from other cancers revealed no association between the presence or the level of the enzyme activity and the expression of the retinoblastoma protein. Telomeres were significantly longer in telomerase-negative tumors than in telomerase-positive tumors (P = .0008). CONCLUSIONS: Our results indicate that retinoblastoma can develop when telomeres are still relatively long and in the absence of telomerase. Telomerase activity associated with short telomeres is, however, observed in 50% of the retinoblastomas and in retinoblastoma-derived cell lines. IMPLICATIONS: Telomerase may not be a marker for acquisition of the malignant phenotype in the case of tumors that are derived from cells with long telomeres and that are associated with a low number of mutations.

Estimation of respiratory mechanics in dogs with acute lung injury.

In mechanically ventilated anesthetized dogs with acute lung injury induced by intravenous infusion of oleic acid (OA), changes in airflow, lung volume, and tracheal (Pao), transpulmonary (Ptp) pressures were measured. Changes in lung mechanics were studied before and after OA infusion at intervals, during an observation period lasting 4-5 hours, by using the interrupter technique and identification technique, and by measuring the pressure-volume (PV) characteristics. The main results are listed as follows: (1) compliance and FRC showed a marked decrease, Pao and Ptp showed a marked increase within 2 hours after OA. (2) airflow resistance estimated by the identification technique showed a marked increase after OA. (3) static PV characteristics of both the lungs and total respiratory system showed similar changes 4 hours after OA, characterized by the presence of an inflexion on the inflation limb, increased hysteresis and a rightward and downward shift of the loop. (4) the trend of changes of dynamic PV characteristics obtained by changing the PEEP value in a stepwise manner, with the ventilation uninterrupted, was similar to that of the static PV curve. It is suggested that an on-line identification technique with one-compartment model to track the slow changes in combination with serial measurements of the dynamic PV characteristics of the total respiratory system would be more appropriate for monitoring lung mechanics of ventilated patients with ARDS.

Purification and kinetic study of glyoxalase-I from rat liver, erythrocytes, brain and kidney.

Glyoxalase-I (S-lactoyl-glutathione methylglyoxal-lyase (isomerizing), EC 4.4.1.5) was purified from rat liver, erythrocytes, brain and kidney using two different purification procedures. The similarities of the purification profiles, electrophoretic mobilities and kinetics suggest that a single major form of the enzyme exists in these tissues. The highest purification (9300-fold) of the erythrocyte enzyme gave nearly homogeneous protein, molecular weight 50 000, specific activity 2410 mumol/min per mg. Kinetic studies of the rat glyoxalase-I-catalyzed disproportionation of the hemimercaptals of GSH and aromatic or aliphatic alpha-ketoaldehydes revealed broad substrate specificity with V and Km values quite insensitive to the nature of the alpha-ketoaldehydes. Use of deuterated analogs of the alpha-ketoaldhydes methylglyoxal and phenylglyoxal showed that the intramolecular hydride migration is the rate-determining step.

Effects of pH and thiols on the kinetics of yeast glyoxalase I. An evaluation of the random pathway mechanism.

The disproportionation of alpha-ketoaldehydes, catalyzed by yeast glyoxalase I, has been reported to involve a random pathway mechanism where one branch utilizes the hemimercaptal of glutathione and the alpha-ketoaldehyde in a one-substrate pathway, and the other branch utilizes first glutathione and then the alpha-ketoaldehyde in an ordered two-substrate pathway. The relative importance of the two pathways has been evaluated at 5 degrees in the pH range 3-7, using methylglyoxal and phenylglyoxal as representative aliphatic and aromatic alpha-ketoaldehydes, by comparing initial rates of hemimercaptal formation in the absence of enzyme with initial rates of product formation in the presence of high enzyme concentrations. If the enzyme is not added last, the initial rates of product formation are the same as the initial rates of adduct formation even under conditions where it could be shown that dehydration of the hydrated alpha-ketoaldehyde is not entirely rate determining. If the enzyme is added after hemimercaptal formation, there is a "burst" of product formation equivalent to the amount of hemimercaptal, followed by a slower reaction, consistent with the one-substrate pathway. Additional support for this pathway was obtained from a study of the effects of added thiol reagents on the "burst" kinetics. The broad specificity of yeast glyoxalase I for both aliphatic and aromatic alpha-ketoaldehydes, reflected in Vmax values which are insensitive to the nature of the alpha-ketoaldehyde drops abruptly if the side chain of the alpha-ketoaldehyde is sterically crowded. The hemimercaptal of tert-butylglyoxal has a Vmax 300-fold smaller than Vmax for methylglyoxal; 2,4,6-trimethylphenylglyoxal is essentially inactive as a substrate even though the closely related compound 2,4-dimethylphenylglyoxal is a normal substrate. Analysis of the Vmax and Km (or Ki) values of these alpha-ketoaldehydes suggests that sterically crowded side chains affect both enzyme-substrate formation and the catalytic reaction.