On the establishment of reference values of clouds of electromyography interference pattern by linear regression method and percentile method and comparison of sensitivity and specificity of both methods.

Objective: Turn-amplitude clouds were widely used in automatic electromyography (EMG) interference pattern analysis. Earlier works employed the intercept ± 2SD (standard deviation) of the linear regression equation as the upper and lower boundaries of the clouds. The goal of this study was to employ the linear regression method and percentile method to calculate the reference value of turn-amplitude clouds, identify the determining criteria in accordance with the receiver operator characteristic curve (ROC), and analyze the sensitivity and specificity of the linear regression cloud, percentile cloud, and quantitative assessment of the motor unit potential (QMUP). Methods: First, we explore what factors affect the number of turns per second and the mean amplitude. Then, their logarithms were taken for the normal test. All muscle data were used to calculate the reference values of percentile clouds. However, the reference values of the linear regression clouds were obtained for the muscles with a bivariate normal distribution, homogeneous variances and a linear correlation. We calculated the prediction interval with the standard errors of the intercept and slope of the linear regression equation, which can determine the upper and lower boundaries of the linear regression clouds. Furthermore, we obtained ROCs of these clouds, which were used as the determining criteria to determine the optimum cut-off values. Finally, our study analyzed the sensitivity and specificity of the linear regression cloud, percentile cloud, and QMUP. Results: We here presented the reference values and ROCs of the linear regression clouds and percentile clouds. We suggest the determining criteria be based on ROCs. The areas under the curve (AUC) of both clouds are larger than 0.8, revealing that they have significant diagnostic value. Our results display that the specificities of the linear regression clouds, percentile clouds, and QMUP are almost identical to each other, whereas the sensitivity of percentile cloud is higher than those of QMUP and linear regression clouds. Conclusion: According to ROCs, the researchers determine the determining criteria of the linear regression clouds and percentile clouds. Our findings suggest that the percentile clouds possess a wide application range and significant diagnostic value, therefore it may be the optimum for automatic EMG interference pattern analysis.

Dynamic profile and clinical implications of hematological parameters in hospitalized patients with coronavirus disease 2019.

Objectives As people across the world suffer from coronavirus disease 2019 (COVID-19), further studies are needed to facilitate evaluating the severity and prognosis of COVID-19 patients. In the study, we aimed to dissect the dynamic profile and clinical implications of hematological findings in hospitalized patients with COVID-19. Methods We retrospectively analyzed the hematological findings of 72 patients with COVID-19 admitted from January 21 to February 17, 2020. The final date of follow-up was March 20, 2020. Dynamic profile of vital hematological parameters in severe and non-severe patients was presented at different time points (day 1, 5, 7, 9, 11, 13, 15 after admission), and the correlation of hematological parameters with hospitalization time was indicated. Results Of 72 patients with COVID-19, lymphopenia and leukopenia occurred in 39 (54.2%) and 20 (27.8%) patients with COVID-19, respectively. Fifteen (20.8%) patients were defined as severe cases and 57 (79.2%) were non-severe cases. Compared to non-severe patients, leukocyte count, neutrophil count and neutrophil-to-lymphocyte ratio (NLR) were significantly higher, whereas lymphocyte count was declined in severe patients at each time point. A growing trend in platelet count was found in non-severe patients over the follow-up period. In addition, a positive correlation of NLR with hospitalization time was detected from day 5 after admission. Conclusions Dynamic changes in vital hematological parameters from severe and non-severe patients had been characterized in the course of hospitalization. During hospitalization, NLR was found to have certain relevance to the hospitalization days and a role in forecasting disease prognosis for patients with COVID-19.

Sestrin2 is involved in asthma: a case-control study.

BACKGROUND: Asthma is a chronic disease that seriously harms the health of patients. Oxidative stress is involved in asthma. As an oxidative stress-inducible protein, sestrin2 is elevated in oxidative stress-related diseases. We aimed to explore whether sestrin2 was involved in asthma. METHODS: Seventy-six subjects (44 in the asthma group, 32 in the control group) were recruited in this study. Plasma sestrin2 levels, peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV1) % predicted, forced vital capacity (FVC) % predicted and FEV1/FVC ratio were measured in controls and in asthmatics both during an exacerbation and when controlled after the exacerbation. RESULTS: The asthma group had a significant higher sestrin2 level than the control group (asthmatics during exacerbation, 1.75 ± 0.53 ng/mL vs. 1.32 ± 0.48 ng/mL, p < 0.001; asthmatics when controlled after the exacerbation, 1.56 ± 0.46 ng/mL vs. 1.32 ± 0.48 ng/mL, p = 0.021, respectively). In addition, sestrin2 was negatively correlated with FEV1% predicted and FEV1/FVC ratio in asthmatics during exacerbation (r = - 0.393, p = 0.008; r = - 0.379, p = 0.011; respectively). Moreover, negative correlations between sestrin2 and FEV1% predicted and FEV1/FVC ratio also existed in asthmatics when controlled after the exacerbation (r = - 0.543, p < 0.001; r = - 0.433, p = 0.003 respectively). More importantly, multiple linear regression analysis demonstrated that FEV1% predicted was independently associated with sestrin2 in asthmatics both during exacerbation and when controlled after the exacerbation. CONCLUSIONS: Sestrin2 is involved in asthma. Sestrin2 levels increase in asthmatics both during exacerbation and when controlled after the exacerbation. In addition, sestrin2 is independently associated with FEV1% predicted.

Causative agents and outcome of spontaneous bacterial peritonitis in cirrhotic patients: community-acquired versus nosocomial infections.

BACKGROUND: Spontaneous bacterial peritonitis (SBP) is a serious complication and common cause of death in patients with liver cirrhosis. This study was conducted to compare the microbiological characteristics, drug resistance, and treatment outcomes for nosocomial SBP and community-acquired SBP. METHODS: A retrospective study was performed on 334 patients with culture-positive SBP at Beijing Youan Hospital, China, between January 2012 and December 2016. The medical records for these patients were reviewed, and their clinical and laboratory data were analyzed. RESULTS: A total of 155 (46.4%) patients with nosocomial SBP and 179 (53.6%) with community-acquired SBP were included in this study. From the patients' ascitic fluids, 334 pathogenic strains, including 178 Gram-negative bacterial strains, 138 Gram-positive bacterial strains and 18 other microbial strains were isolated. E. coli was the major pathogen (24.3%), followed by Klebsiella pneumoniae (12.0%) and Enterococcus faecium (10.5%). The proportion of Enterococcus was significantly higher in the patients with nosocomial SBP (6.1% vs. 27.7%, P < 0.001) than in the patients with community-acquired SBP. The main pathogens isolated from the nosocomial infections were significantly more resistant to the first-line recommended drug. Compared with community-acquired SBP, nosocomial SBP had a poorer outcome (36.8% vs. 24.6%; P = 0.016). The independent predictors for 30-day mortality included nosocomial infection, Child-Pugh classification, hepatocellular carcinoma, renal failure and hepatic encephalopathy. CONCLUSION: Gram-negative bacteria were the major pathogens involved in SBP in the cirrhotic patients. The strains isolated from the patients with nosocomial SBP displayed higher drug resistance than those isolated from patients with community-acquired SBP. Compared with community-acquired SBP, nosocomial SBP had a poorer outcome. When choosing drug treatments, the acquisition site of infection and the local epidemiological situation should be taken into account.

Bacteremia due to Gordonia polyisoprenivorans: case report and review of literature.

BACKGROUND: Gordonia polyisoprenivorans is a ubiquitous aerobic actinomycetes bacterium that rarely cause infections in humans. Here, we report a case of G. polyisoprenivorans catheter-related bacteremia in an AIDS patient. CASE PRESENTATION: A 37-year-old man with a past medical history of AIDS-related lymphoma suffered bacteremia caused by a Gram-positive corynebacterium. The strain was identified as a Gordonia species by matrix-assisted laser desorption ionization-time of flight mass spectrometry and confirmed to G. polyisoprenivorans by 16S rRNA combined with gyrB gene sequencing analyses. The patient was treated with imipenem and had a good outcome. CONCLUSIONS: The findings from our case and previously reported cases indicate that malignant hematologic disease, immunosuppression, and indwelling catheter heighten the risk for G. polyisoprenivorans infection. Molecular methods should be employed for proper identification of G. polyisoprenivorans to the species level.

Deletion of meso-2,3-butanediol dehydrogenase gene budC for enhanced D-2,3-butanediol production in Bacillus licheniformis.

BACKGROUND: D-2,3-butanediol has many industrial applications such as chiral reagents, solvents, anti-freeze agents, and low freezing point fuels. Traditional D-2,3-butanediol producing microorganisms, such as Klebsiella pneumonia and K. xoytoca, are pathogenic and not capable of producing D-2,3-butanediol at high optical purity. Bacillus licheniformis is a potential 2,3-butanediol producer but the wild type strain (WX-02) produces a mix of D- and meso-type isomers. BudC in B. licheniformis is annotated as 2,3-butanediol dehydrogenase or acetoin reductase, but no pervious experiment was performed to verify this hypothesis. RESULTS: We developed a genetically modified strain of B. licheniformis (WX-02 ΔbudC) as a D-2,3-butanediol producer with high optimal purity. A marker-less gene deletion protocol based on a temperature sensitive knock-out plasmid T2-Ori was used to knock out the budC gene in B. licheniformis WX-02. The budC knock-out strain successfully abolished meso-2,3-butanediol production with enhanced D-2,3-butanediol production. No meso-BDH activity was detectable in cells of this strain. On the other hand, the complementary strain restored the characteristics of wild strain, and produced meso-2,3-butanediol and possessed meso-BDH activity. All of these data suggested that budC encoded the major meso-BDH catalyzing the reversible reaction from acetoin to meso-2,3-butanediol in B. licheniformis. The budC knock-out strain produced D-2,3-butanediol isomer only with a high yield of 30.76 g/L and a productivity of 1.28 g/L-h. CONCLUSIONS: We confirmed the hypothesis that budC gene is responsible to reversibly transfer acetoin to meso-2,3-butanediol in B. licheniformis. A mutant strain of B. licheniformis with depleted budC gene was successfully developed and produced high level of the D-2,3-butanediol with high optimal purity.

Synthesis, characterization and fluorescence properties of boron difluoride pyridyl-ß-diketonate derivatives.

Five pyridyl-ß-diketones were synthesized by Claisen condensation of ethyl nicotinate with various aryl methyl ketones in benzene in the presence of sodium amide as the base, and then reacted with boron trifluoride diethyl etherate in dichloromethane to afford some new boron difluoride pyridyl-ß-diketonate derivatives. The compounds obtained were characterized using FTIR, (1)H NMR, elemental analysis and mass spectrometry. Their optical properties were studied in DMF by UV-vis absorption and fluorescence spectroscopy. The results showed that these boron complexes exhibited intense fluorescence in the blue-green region (420-490 nm) under UV radiation with a relatively high quantum yield. Especially, compounds 4b and 5b displayed much higher quantum yield as compared to compounds 1b, 2b and 3b.

[Serum GP73 were increased in patients with fatty liver disease].

OBJECTIVE: To explore the levels of serum GP73 in patients with fatty liver disease. METHODS: The sera GP73 were determined by ELISA in 178 patients with fatty liver disease and 100 healthy controls. RESULTS: Serum GP73 levels were significantly increased in patients with various fatty liver diseases(70.62 +/- 60.60 ng/ml), compared with those of control population (35.61 +/- 12.22 ng/ml). In patients with alcoholic fatty liver disease, acute liver injury, chronic hepatitis B, and non-alcoholic fatty liver disease, their serum GP73 concentration were 81.86 +/- 47.82 ng/ml, 82.77 +/- 77.73 ng/ml, 63.84 +/- 50.62 ng/ml, and 65.75 +/- 62.20 ng/ml, respectively. But no significant difference was found between these groups (P > 0.05). In 68 patients with F > or = 1.0 (71.46 +/- 66.48 ng/ml), 75 patients with F> or = 2.0 (69.58 +/- 62.31 ng/ml), and 34 patients with F3-F4 (71.65 +/- 43.89 ng/ml), there were also no marked differences was observed between these fatty groups (F = 0.02, P = 0.98). CONCLUSION: Serum GP73 levels were increased in patients with different liver diseases, but its concentrations were seems not related with degree of fatty injury.