[Analysis of transfusion effect of different platelet matching schemes in patients with platelet transfusion refractoriness]

Objective: To analyze the transfusion effect of different platelet matching schemes in patients with platelet transfusion refractoriness (PTR). Methods: A total of 94 patients with PTR received by Taiyuan Blood Center from January to December 2021 were retrospectively analyzed, including 26 males and 68 females, aged 53(34,66) years. Platelet antibody screening was performed by enzyme-linked immunosorbent assay (ELISA). For patients with positive human leukocyte antigen (HLA) class Ⅰ antibodies, Luminex platform liquid chip assay was used to identify the specificity of antibodies, and platelets with missing allelic expression antigen corresponding to their specific antibodies were found in the platelet donor gene database established in our laboratory. For patients with negative class HLA-Ⅰ antibody screening, medium and high-resolution HLA-A and B alleles were genotyped by polymerase chain reaction restriction sequence specific oligonucleotide (PCR-SSO), and the compatible platelets were searched from the platelet donor gene database by HLA cross-reactive group genotype matching scheme or directly selected by serological cross-matching. The PCI compliance rate and total transfusion effective rate of different mismatch site groups and different matching scheme groups were statistically analyzed. Results: Platelet antibody was detected in 39 of 94 PTR patients with a positive rate of 41.5%, and all of them were HLA-Ⅰ antibodies, and 1 case was accompanied by human platelet antigen (HPA) antibody. A total of 134 times of compatible platelets were supplied to 39 patients with HLA-Ⅰ antibody positive by using antibody avoidance matching method. And the total effective rate of transfusion was 97.8% (131/134); The PCI compliance rates of HLA-A antigen mismatch, HLA-B antigen mismatch and HLA-A and B antigen mismatch groups were 81.6% (31/38), 86.5% (32/37) and 78.6% (22/28), respectively. The total effective rate of transfusion was 97.4% (37/38), 94.6% (35/37) and 100% (28/28), respectively, with no statistical significance (all P>0.05). A total of 118 times of compatible platelets were provided by HLA antigen cross-reaction group genotype matching and serological cross-matching, 90 transfusion effects were collected during follow-up, and the total effective rate was 76.7% (69/90). Conclusion: The combination of different platelet matching schemes can improve the PCI compliance rate and the total effective rate of transfusion in PTR patients.

Machine learning based ischemia-specific stenosis prediction: A Chinese multicenter coronary CT angiography study

OBJECTIVES

To evaluate the performance of coronary computed tomography angiography (CCTA) derived characteristics including CT derived fractional flow reserve (CT-FFR) with FFR as a reference standard in identifying the lesion-specific ischemia by machine learning (ML) algorithms.

METHODS

The retrospective analysis enrolled 596 vessels in 462 patients (mean age, 61 years ± 11 [SD]; 71.4 % men) with suspected coronary artery disease who underwent CCTA and invasive FFR. The data were divided into training cohort, internal validation cohort, external validation cohorts 1 and 2 according to participating centers. All CCTA-derived parameters, which contained 10 qualitative and 33 quantitative plaque parameters, were collected to establish ML model. The Boruta and unsupervised clustering algorithm were implemented to select important and non-redundant parameters. Finally, the eight features with the highest mean importance were included for further ML model establishment and decision tree building. Five models were built to predict lesion-specific ischemia: stenosis degree from CCTA, CT-FFR, ΔCT-FFR, ML model and nested model.

RESULTS

Low-attenuation plaque, bend and lesion length were the main predictors of ischemia-specific lesions. Of 5 models, the ML model showed favorable discrimination for ischemia-specific lesions in the training and three validation sets (area under the curve [95 % confidence interval], 0.93 [0.90-0.96], 0.86 [0.79-0.94], 0.88 [0.83-0.94], and 0.90 [0.84-0.96], respectively). The nested model which combined the ML model and CT-FFR showed better diagnostic efficacy (AUC [95 %CI], 0.96 [0.94-0.99], 0.92 [0.86-0.99], 0.92 [0.86-0.99] and 0.94 [0.91-0.98], respectively; all P < 0.05), and net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were significantly higher than CT-FFR alone.

CONCLUSIONS

Comprehensive CCTA-derived multiparameter model could better predict the ischemia-specific lesions by ML algorithms compared to stenosis degree from CTA, CT-FFR and ΔCT-FFR. Decision tree can be used to predict myocardial ischemia effectively.

Optimal Measurement Sites of Coronary-Computed Tomography Angiography-derived Fractional Flow Reserve: The Insight From China CT-FFR Study

OBJECTIVES

To investigate the optimal measurement site of coronary-computed tomography angiography-derived fractional flow reserve (FFR CT ) for the assessment of coronary artery disease (CAD) in the whole clinical routine practice.

MATERIALS AND METHODS

This retrospective multicenter study included 396 CAD patients who underwent coronary-computed tomography angiography, FFR CT , and invasive FFR. FFR CT was measured at 1 cm (FFR CT -1 cm), 2 cm (FFR CT -2 cm), 3 cm (FFR CT -3 cm), and 4 cm (FFR CT -4 cm) distal to coronary stenosis, respectively. FFR CT and invasive FFR ≤0.80 were defined as lesion-specific ischemia. The diagnostic performance of FFR CT to detect ischemia was obtained using invasive FFR as the reference standard. Reduced invasive coronary angiography rate and revascularization efficiency were calculated. After a median follow-up of 35 months in 267 patients for major adverse cardiovascular events (MACE), Cox hazard proportional models were performed with FFR CT values at each measurement site.

RESULTS

For discriminating lesion-specific ischemia, the areas under the curve of FFR CT -1 cm (0.91) as well as FFR CT -2 cm (0.91) were higher than those of FFR CT -3 cm (0.89) and FFR CT -4 cm (0.88), respectively (all P <0.05). The higher reduced invasive coronary angiography rate (81.6%) was found at FFR CT -1 cm than FFR CT -2 cm (81.6% vs. 62.6%, P <0.05). Revascularization efficiency did not differ between FFR CT -1 cm and FFR CT -2 cm (80.8% vs. 65.5%, P =0.019). In 12.4% (33/267) MACE occurred and only values of FFR CT -2 cm were independently predictive of MACE (hazard ratio: 0.957 [95% CI: 0.925-0.989]; P =0.010).

CONCLUSIONS

This study indicates FFR CT -2 cm is the optimal measurement site with superior diagnostic performance and independent prognostic role.

Angell plot from the potential energy landscape perspective

Within the scenario of the potential energy landscape (PEL), a thermodynamic model has been developed to uncover the physics behind the Angell plot. In our model, by separating the barrier distribution in PELs into a Gaussian-like and a power-law form, we obtain a general relationship between the relaxation time and the temperature. The wide range of the experimental data in the Angell plot, as well as the molecular-dynamics data, can be excellently fitted by two characteristic parameters, the effective barrier (ω) and the effective width (σ) of a Gaussian-like distribution. More importantly, the fitted ω and σ^{2} for all glasses are found to have a simple linear relationship within a very narrow band, and fragile and strong glasses are well separated in the ω-σ^{2} plot, which indicates that glassy states appear only in a specific region of the PEL.

[Establish and application of scoring scale for trial of labor after cesarean section]

Objective: To establish a scoring scale for trial of labor after cesarean section (TOLAC), to explore the evaluation ability of this scoring scale for vaginal delivery after cesarean section (VBAC), and to improve the success rate of TOLAC. Methods: The delivery information of 661 TOLAC pregnant women admitted to Zhengzhou Central Hospital Affiliated to Zhengzhou University from 2014 to 2017 was retrospectively analyzed, and the TOLAC scoring scale was established by referring to relevant literatures. A prospective cohort study of pregnant women with TOLAC from January 2018 to December 2019 in Zhengzhou Central Hospital was conducted, including 440 pregnant women who were excluded from contraindications in trial labor. According to TOLAC scoring scale, pregnant women were divided into 3 groups, 0-6 group (94 cases), 7-9 group (234 cases) and 10-15 group (112 cases). The success rate of trial labor, failure reasons and incidence of maternal and neonatal complications were compared among the three groups. Results: (1) The overall success rate of TOLAC in 440 pregnant women was 75.0% (330/440). The success rates of 0-6, 7-9 and 10-15 groups were 53.2% (50/94), 76.9% (180/234) and 89.3% (100/112), respectively. The success rate of 10-15 group were significantly higher than those of 0-6 and 7-9 groups (all P<0.05). (2) Among the causes of trial labor failure, there were statistically significant differences between the three groups in terms of threatened uterine rupture and maternal abandonment (all P<0.05). Pairings showed that the incidences of threatened uterine rupture and maternal abandonment in 0-6 group was lower than those in 7-9 and 10-15 groups, and the differences were statistically significant (all P<0.05). (3) Maternal and neonatal complications mainly included postpartum hemorrhage and neonatal asphyxia, but there were no significant difference in the incidence of TOLAC success or failure among the three groups (all P>0.05). There was no uterine rupture in all groups. (4) The main factors affecting TOLAC score of pregnant women in the three groups included natural labor, estimated weight of the fetus at this time, Bishop score of the cervix at admission and gestational age, and the scores of the above indexes in 10-15 group were significantly higher than those in 0-6 group and 7-9 group (all P<0.05). Conclusions: TOLAC scoring scale has more accurate evaluation ability for VBAC, which could improve the success rate of TOLAC and maternal and child safety. The score of 0-6 is not recommended for vaginal trial labor, the score of 7-9 is recommended for vaginal trial labor, and the score of 10-15 is strongly recommended for vaginal trial labor.

[A study of the effectiveness of nucleos(t)ide analogues in the treatment of HBeAg- positive chronic hepatitis B with normal alanine aminotransferase and high level of HBV DNA]

Objective: To investigate the effectiveness of nucleos(t)ide analogues in the treatment of HBeAg-positive chronic hepatitis B with normal alanine aminotransferase and high level of HBV DNA. Methods: Treatment-naïve chronic hepatitis B patients who were followed up at the Center of Infectious Diseases, West China Hospital of Sichuan University from January 2019 to January 2020 were selected as subjects. Demographic characteristics, the results of laboratory examination before treatment and one year after treatment were retrospectively collected. Patients were divided into tenofovir dipivoxil (TDF) and propofol fumurate tenofovir (TAF) treatment group according to different types of medication. The changes of serum HBV DNA level, HBeAg serological conversion and HBsAg quantitative level were analyzed and compared between the two groups. Results: A total of 38 cases were enrolled. Among them, there were 16 and 22 cases in the TDF and TAF group, respectively. There was no statistically significant difference in demographic characteristics, baseline HBV DNA levels and HBsAg quantitative levels between the two groups. Virological response was achieved in 60.5% (23/38) of patients after one year of antiviral therapy. Serum HBV DNA levels below the lower limit of detection [68.2% (15/22) vs. 50.0% (8/16), P=0.258] and higher HBeAg seroconversion rate [18.2%] (4/22) vs. 6.3% (1/16), P=0.374] was obtained in TAF than TDF group; however, there was no statistically significant differences between the two. Serum HBsAg quantitative level was significantly reduced with TDF and TAF treatment. In addition, alanine aminotransferase elevation was reduced in TAF than TDF treated group. Multivariate logistic regression analysis showed that patient age was an independent predictor of a virological response to antiviral therapy. Conclusion: HBeAg-positive CHB patients with normal alanine aminotransferase, and high HBV DNA level can obtain better curative effect after TDF and TAF treatment.

[Diagnostic value of combined application of GATA3, SOX10 and p16 in triple negative breast carcinomas]

Objective: To investigate the expression of GATA3, SOX10, and p16 in triple-negative breast cancer (TNBC) and analyze their significance and correlation with clinicopathology. Methods: The expressions of GATA3, SOX10 and p16 in 53 cases of TNBC and 50 cases of non-TNBC were detected by immunohistochemical staining. Results: GATA3 and SOX10 were positive in 58.5%(31/53) and 75.5%(40/53) of TNBC, respectively. The expression of SOX10 was significantly higher than that in non-TNBC (P<0.05). SOX10 was positive in 17 of the 22 cases that lacked GATA3 expression (77.3%). The expression of p16 was significantly higher in the TNBC, and the co-expression with SOX10 was significantly increased (P<0.05). The sensitivity, specificity, and AUC under the ROC curve of SOX10 were higher than those of GATA3. The sensitivity of SOX10 was higher than that of p16, but the specificity was lower than that of p16. The AUC of SOX10 was higher than that of p16. AUC of combined detection of GATA3 and SOX10, SOX10 and p16 were higher than that of each antibody alone (P<0.05). The expression of GATA3, SOX10, and p16 had no significant correlation with age, tumor size, and lymph node metastasis. The expression of SOX10 and p16 in grade 3 and basal-like TNBC increased significantly, and their co-expression increased. Conclusions: The expressions of SOX10 and p16 in TNBC are significantly increased. SOX10 is a reliable marker for the diagnosis of TNBC and a supplement to GATA3. Whether p16 is a marker related to the prognosis of TNBC remains to be further studied.

Leveraging Radiobiology for Arrhythmia Management: A New Treatment Paradigm?

Radiation therapy is a well-established approach for safely and non-invasively treating solid tumours and benign diseases with high precision and accuracy. Cardiac radiation therapy has recently emerged as a non-invasive treatment option for the management of refractory ventricular tachycardia. Here we summarise existing clinical and preclinical literature surrounding cardiac radiobiology and discuss how these studies may inform basic and translational research, as well as clinical treatment paradigms in the management of arrhythmias.

[Surgical site infection after abdominal surgery in China: a multicenter cross-sectional study]

Objective: Surgical site infection (SSI) can markedly prolong postoperative hospital stay, aggravate the burden on patients and society, even endanger the life of patients. This study aims to investigate the national incidence of SSI following abdominal surgery and to analyze the related risk factors in order to provide reference for the control and prevention of SSI following abdominal surgery. Methods: A multicenter cross-sectional study was conducted. Clinical data of all the adult patients undergoing abdominal surgery in 68 hospitals across the country from June 1 to 30, 2020 were collected, including demographic characteristics, clinical parameters during the perioperative period, and the results of microbial culture of infected incisions. The primary outcome was the incidence of SSI within postoperative 30 days, and the secondary outcomes were ICU stay, postoperative hospital stay, cost of hospitalization and the mortality within postoperative 30-day. Multivariable logistic regression was used to analyze risk factors of SSI after abdominal surgery. Results: A total of 5560 patients undergoing abdominal surgery were included, and 163 cases (2.9%) developed SSI after surgery, including 98 cases (60.1%) with organ/space infections, 19 cases (11.7%) with deep incisional infections, and 46 cases (28.2%) with superficial incisional infections. The results from microbial culture showed that Escherichia coli was the main pathogen of SSI. Multivariate analysis revealed hypertension (OR=1.792, 95% CI: 1.194-2.687, P=0.005), small intestine as surgical site (OR=6.911, 95% CI: 1.846-25.878, P=0.004), surgical duration (OR=1.002, 95% CI: 1.001-1.003, P<0.001), and surgical incision grade (contaminated incision: OR=3.212, 95% CI: 1.495-6.903, P=0.003; Infection incision: OR=11.562, 95%CI: 3.777-35.391, P<0.001) were risk factors for SSI, while laparoscopic or robotic surgery (OR=0.564, 95%CI: 0.376-0.846, P=0.006) and increased preoperative albumin level (OR=0.920, 95%CI: 0.888-0.952, P<0.001) were protective factors for SSI. In addition, as compared to non-SSI patients, the SSI patients had significantly higher rate of ICU stay [26.4% (43/163) vs. 9.5% (514/5397), χ(2)=54.999, P<0.001] and mortality within postoperative 30-day [1.84% (3/163) vs.0.01% (5/5397), χ(2)=33.642, P<0.001], longer ICU stay (median: 0 vs. 0, U=518 414, P<0.001), postoperative hospital stay (median: 17 days vs. 7 days, U=656 386, P<0.001), and total duration of hospitalization (median: 25 days vs. 12 days, U=648 129, P<0.001), and higher hospitalization costs (median: 71 000 yuan vs. 39 000 yuan, U=557 966, P<0.001). Conclusions: The incidence of SSI after abdominal surgery is 2.9%. In order to reduce the incidence of postoperative SSI, hypoproteinemia should be corrected before surgery, laparoscopic or robotic surgery should be selected when feasible, and the operating time should be minimized. More attentions should be paid and nursing should be strengthened for those patients with hypertension, small bowel surgery and seriously contaminated incision during the perioperative period.

[Risk factors for surgical site infection after emergency abdominal surgery: a multicenter cross-sectional study in China]

Objective: Surgical site infection (SSI) is the most common infectious complication after emergency abdominal surgery (EAS). To a large extent, most SSI can be prevented, but there are few relevant studies in China. This study mainly investigated the current situation of SSI occurrence after EAS in China, and further explored risk factors for SSI occurrence. Methods: Multi-center cross-sectional study was conducted. Clinical data of patients undergoing EAS in 33 hospitals across China between May 1, 2019 and June 7, 2019 were prospectively collected, including perioperative data and microbial culture results from infected incisions. The primary outcome was the incidence of SSI after EAS, while the secondary outcomes were postoperative hospital stay, ICU occupancy rate, length of ICU stay, hospitalization cost, and mortality within postoperative 30 days. Univariate and multivariate logistic regression models were used to analyze the risk factors of SSI after EAS. Results: A total of 660 EAS patients aged (47.9±18.3) years were enrolled in this study, including 56.5% of males (373/660). Forty-nine (7.4%) patients developed postoperative SSI. The main pathogen of SSI was Escherichia coli [culture positive rate was 32.7% (16/49)]. As compared to patients without SSI, those with SSI were more likely to be older (median 56 years vs. 46 years, U=19 973.5, P<0.001), male [71.4% (35/49) vs. 56.1% (343/611), χ(2)=4.334, P=0.037] and diabetes [14.3% (7/49) vs. 5.1% (31/611), χ(2)=5.498, P=0.015]; with-lower preoperative hemoglobin (median: 122.0 g/L vs. 143.5 g/L, U=11 471.5, P=0.006) and albumin (median: 35.5 g/L vs. 40.8 g/L, U=9452.0, P<0.001), with higher blood glucose (median: 6.9 mmol/L vs. 6.0 mmol/L, U=17 754.5, P<0.001); with intestinal obstruction [32.7% (16/49) vs. 9.2% (56/611), χ(2)=25.749, P<0.001], with ASA score 3-4 [42.9% (21/49) vs. 13.9% (85/611), χ(2)=25.563, P<0.001] and with high surgical risk [49.0% (24/49) vs. 7.0% (43/611), χ(2)=105.301, P<0.001]. The main operative procedure resulting in SSI was laparotomy [81.6%(40/49) vs. 35.7%(218/611), χ(2)=40.232, P<0.001]. Patients with SSI experienced significantly longer operation time (median: 150 minutes vs. 75 minutes, U=25 183.5, P<0.001). In terms of clinical outcome, higher ICU occupancy rate [51.0% (25/49) vs. 19.5% (119/611), χ(2)=26.461, P<0.001], more hospitalization costs (median: 44 000 yuan vs. 15 000 yuan, U=24 660.0, P<0.001), longer postoperative hospital stay (median: 10 days vs. 5 days, U=23 100.0, P<0.001) and longer ICU occupancy time (median: 0 days vs. 0 days, U=19 541.5, P<0.001) were found in the SSI group. Multivariate logistic regression analysis showed that the elderly (OR=3.253, 95% CI: 1.178-8.985, P=0.023), colorectal surgery (OR=9.156, 95% CI: 3.655-22.937, P<0.001) and longer operation time (OR=15.912, 95% CI:6.858-36.916, P<0.001) were independent risk factors of SSI, while the laparoscopic surgery (OR=0.288, 95% CI: 0.119-0.694, P=0.006) was an independent protective factor for SSI. Conclusions: For patients undergoing EAS, attention should be paid to middle-aged and elderly patients and those of colorectal surgery. Laparoscopic surgery should be adopted when feasible and the operation time should be minimized, so as to reduce the incidence of SSI and to reduce the burden on patients and medical institutions.

The effect of coronary calcification on diagnostic performance of machine learning-based CT-FFR: a Chinese multicenter study

OBJECTIVE

To investigate the effect of coronary calcification morphology and severity on the diagnostic performance of machine learning (ML)-based coronary CT angiography (CCTA)-derived fractional flow reserve (CT-FFR) with FFR as a reference standard.

METHODS

A total of 442 patients (61.2 ± 9.1 years, 70% men) with 544 vessels who underwent CCTA, ML-based CT-FFR, and invasive FFR from China multicenter CT-FFR study were enrolled. The effect of calcification arc, calcification remodeling index (CRI), and Agatston score (AS) on the diagnostic performance of CT-FFR was investigated. CT-FFR ≤ 0.80 and lumen reduction ≥ 50% determined by CCTA were identified as vessel-specific ischemia with invasive FFR as a reference standard.

RESULTS

Compared with invasive FFR, ML-based CT-FFR yielded an overall sensitivity of 0.84, specificity of 0.94, and accuracy of 0.90 in a total of 344 calcification lesions. There was no statistical difference in diagnostic accuracy, sensitivity, or specificity of CT-FFR across different calcification arc, CRI, or AS levels. CT-FFR exhibited improved discrimination of ischemia compared with CCTA alone in lesions with mild-to-moderate calcification (AUC, 0.89 vs. 0.69, p < 0.001) and lesions with CRI ≥ 1 (AUC, 0.89 vs. 0.71, p < 0.001). The diagnostic accuracy and specificity of CT-FFR were higher than CCTA alone in patients and vessels with mid (100 to 299) or high (≥ 300) AS.

CONCLUSION

Coronary calcification morphology and severity did not influence diagnostic performance of CT-FFR in ischemia detection, and CT-FFR showed marked improved discrimination of ischemia compared with CCTA alone in the setting of calcification.

KEY POINTS

• CT-FFR provides superior diagnostic performance than CCTA alone regardless of coronary calcification. • No significant differences in the diagnostic performance of CT-FFR were observed in coronary arteries with different coronary calcification arcs and calcified remodeling indexes. • No significant differences in the diagnostic accuracy of CT-FFR were observed in coronary arteries with different coronary calcification score levels.

Retention Time and Ion Abundance Ratio of 8 Common Drugs （Poisons） by LC-MS/MS Qualitative Analysis

Objective To investigate the maximum allowable deviations of retention time and ion abundance ratio of the 8 common drugs （poisons） from 3 categories, poisons （methamphetamine, morphine, ketamine）, benzodiazepines （estazolam, midazolam, diazepam, clonazepam） and barbiturates （phenobarbital） in blood, by liquid chromatography-tandem mass spectrometry （LC-MS/MS） in forensic toxicology analysis. Methods The deviations of retention time and ion abundance ratio at 7 low mass concentrations, limit of detection （LOD）, 2LOD, limit of quantitation （LOQ）, 1.5LOQ, 2LOQ, 4LOQ and 6LOQ, were tested by LC-MS/MS after liquid-liquid extraction under the conditions of two chromatographic columns and three chromatographs. Results The deviation of absolute retention time of 98.11% of 8 drugs （poisons） in the blood samples was within the range of ±0.05 min, and that of the relative retention time of 96.21% was within the range of ±0.4%. The maximum deviation of the ion abundance ratio was highly correlated with the mass concentration. When the mass concentration of drugs （poisons） was LOQ or above, more than 95% of the absolute deviation and relative deviation of the ion abundance ratio were in the range of ±25% and ±40%, respectively; when the mass concentration was below LOQ, the range could be expanded to ±35% and ±50%, respectively. Conclusion It is recommended for the determination range of the absolute retention time deviation of 8 common drugs （poisons） to be ±0.1 min and that of the relative retention time deviation to be ±1.0%. The determination range of absolute deviation of the ion abundance ratio should be ±25% when the mass concentration is LOQ or above, and the relative deviation should be ±40%. When the mass concentration is below LOQ, the deviation determination range can be expanded to ±35% and ±50%, respectively.

[Effect of cognitive impairment on social function and quality of life in chronic schizophrenia]

Objective: To clarify the effect of cognitive impairment on social function and quality of life of chronic schizophrenia, and provide clinical cognitive strategies for improving the social function and quality of life of patients with schizophrenia. Methods: Atotal of 158 patients with chronic schizophrenia were selected from May 2017 to October 2017 in the Psychiatry Department of the Third Affiliated Hospital of Sun Yat-sen University received psychological assessments, such as, MATRICS Consensus Cognitive Battery(MCCB), the Brief Psychiatric Rating Scale(BPRS), the Personal and Social Performance scale(PSP), and Schizophrenia Quality of Life Scale(SQLS). We further explored the effects of neurocognitive and social cognitive functions on their individual and social performance and quality of life in patients with schizophrenia. Results: (1) The scores of SQLS in the group with impaired social cognitive function were higher than those with good social function(101±46 vs 76±40, P=0.002). (2) The digital sequence and continuous performance test of the socially functional group were higher than the defect group. (3) There was a significant correlation between the years of education(R(2)=0.334, F=25.542), continuous performance (R(2)=0.316, F=35.647), BPRS (R(2)=0.280, F=60.386) and social function (P<0.001). (4) BPRS (R(2)=0.486, F=228.28), and emotional management (MSCEIT) (R(2)=0.510, F=124.789), education (R(2)=0.531, F=90.161), age (R(2)=0.539, F=69.644) significantly affected the SQLS score of patients with schizophrenia(P<0.001). Conclusion: The social function and quality of life of patients with schizophrenia are significantly correlated with their years of education and disease severity. Continuous performance in neurocognition significantly affects the social function of patients with schizophrenia, and emotional management in social cognition significantly affects their quality of life. Socially functional schizophrenia patients have higher digital sequences (working memory) and continuous performance (attention/alertness) scores.

Ion Abundance Ratios of Qualitative Analysis by GC-MS of 4 Common Drugs （Poisons

Objective To investigate the maximum allowable deviation of ion abundance ratios of characteristic fragment ions in common drugs （poisons） in blood by gas chromatography-mass spectrometry （GC-MS） method. Methods Four common drugs （poisons） （dichlorvos, phorate, diazepam and estazolam） were detected by GC-MS full scan mode after liquid-liquid extraction in two laboratories and under three chromatographic conditions. The deviations of ion abundance ratios of the four common drugs （poisons） in marked blood samples with concentrations of 0.5, 1.0, 2.0, 5.0 and 10.0 μg/mL were analyzed. At the same time, the false negative rates of ion abundance ratios were analyzed when the mass concentration was limit of detection （LOD）, 2LOD, limit of quantitation （LOQ） and 2LOQ, and the false positive rates of ion abundance ratios were analyzed with blank blood samples. Results Under the two laboratories, four common drugs （poisons） and three kinds of chromatography conditions, the differences in deviations of the ion abundance ratios of marked blood samples were not statistically significant （P>0.05）. More than 95% of the absolute deviations of the ion abundance ratios of the marked blood samples were within the range of ±10%, and more than 95% of the relative deviations were within the range of ±25%. In cases of low concentration （concentration less than 2LOQ） or low signal to noise ratio （3-15）, the false negative rate was less than 5% and the false positive rate was 0% when the relative deviation was greater than 50%. Conclusion The absolute deviations of ion abundance ratios of four common drugs （poisons） in marked blood samples are advised to have a determination range within ±10%, and the determination range of relative deviations within ±25%.

Diagnostic Performance of Machine Learning Based CT-FFR in Detecting Ischemia in Myocardial Bridging and Concomitant Proximal Atherosclerotic Disease

BACKGROUND

The diagnostic performance of coronary computed tomography angiography-derived fractional flow reserve (CT-FFR) in detecting ischemia in myocardial bridging (MB) has not been investigated to date.

METHODS

This retrospective multicentre study included 104 patients with left anterior descending MBs. MB was classified as either superficial or deep, short, or long, whereas all MB vessels were further divided into <50%, 50% to 69%, and ≥70% groups, according to proximal lumen stenosis on invasive coronary angiography. Diagnostic performance and receiver operating characteristics (ROC) of CT-FFR to detect lesion-specific ischemia was assessed on a per-vessel level, using invasive FFR as reference standard. Intraclass correlation coefficient (ICC) and Bland-Altman plots were used for agreement measurement.

RESULTS

Forty-eight MB vessels (46.2%) showed ischemia by invasive FFR (≤0.80). Sensitivity, specificity, and accuracy of CT-FFR to detect functional ischemia were 0.96 (0.85 to 0.99), 0.84 (0.71 to 0.92), and 0.89 (0.81 to 0.94), respectively, in all MB vessels. There were no differences in diagnostic performance between superficial and deep MB or between short and long MB (all P > 0.05). The accuracy of CT-FFR was 0.96 (0.85 to 0.99) in ≥70% stenosis, 0.82 (0.67 to 0.91) in 50% to 69% stenosis, and 0.89 (0.51 to 0.99) in <50% stenosis (P = 0.081). Bland-Altman analysis showed a slight mean difference between CT-FFR and invasive FFR of 0.014 (95% limit of agreement, -0.117 to 0.145). The ICC was 0.775 (95% confidence interval, 0.685-0.842, P < 0.001).

CONCLUSIONS

CT-FFR demonstrated high diagnostic performance for identifying functional ischemia in vessels with MB and concomitant proximal atherosclerotic disease when compared with invasive FFR. However, the clinical use of CT-FFR in patients with MB needs further study for stronger and more robust results.

[The role of neutrophil in the pathogenesis of chronic rhinosinusitis]

SummaryChronic nasal-sinusitis is a chronic inflammatory disease characterized by persistent inflammation in the nasal and nasal mucosa. The pathogenesis of CRS is extremely complex and there is currently a lack of effective therapy. The reason for inaccurate diagnosis and invalid treatment of CRS is its sophisticated and unclear mechanism. The pathogenesis of CRS from Asian populations is neutrophil infiltration mediated by Th1/Th17 mixture. Consequently, exploring the function of neutrophil in the pathogenesis of CRS plays an important role in clinical diagnosis and treatment for CRS patients in China.

Response of AMP-activated protein kinase and lactate metabolism of largemouth bass (Micropterus salmoides) under acute hypoxic stress

To study adaptation of largemouth bass (Micropterus salmoides) to hypoxic stress, we investigated physiological responses and lactate metabolism of the fish under acute hypoxia. The objectives of this study were to (a) observe changes in glucose, glycogen, and lactate content; (b) detect the activity of lactate dehydrogenase (LDH) in serum, brain, heart, and liver tissues; and (c) quantify the dynamic gene expression of AMP activated protein kinase alpha (AMPKα), hypoxia-inducible factor-1 alpha (HIF-1α), monocarboxylate transporter 1 (MCT1), monocarboxylate transporter 4 (MCT4), and lactate dehydrogenase-a (LDHa) following exposure to hypoxia. The fish were subjected to two hypoxia stresses (dissolved oxygen [DO] 1.20 ± 0.2 mg/L and 3.50 ± 0.3 mg/L, respectively) for 24 h. Our results showed that hypoxic stress significantly increased the decomposition of liver glycogen and significantly increased the concentration of blood glucose; however, the muscle glycogen content was not significantly decreased, which indicates that liver glycogen was the main energy source under acute hypoxia. Moreover, hypoxia led to accumulation of a large amount of lactic acid in tissues, possibly due to the activity of lactic acid dehydrogenase, but this process was delayed in the heart and brain relative to the liver. Additionally, hypoxia induced the expression of AMPKα, HIF-1α, MCT1, MCT4, and LDHa, suggesting that glycometabolism had switched from aerobic to anaerobic. Our results contribute to a better understanding of the molecular mechanisms of the response to hypoxia in largemouth bass.

Retention Time of Four Common Poisons （Drugs） by GC-MS Qualitative Analysis

OBJECTIVES

To investigate the maximum allowable deviation of retention time （RT） or relative retention time （RRT） between the common poisons （drugs） and standard solvent by gas chromatography-mass spectrometry （GC-MS）.

METHODS

After pretreatment with liquid-liquid extraction, four common poisons （drugs）-dichlorvos, phorate, diazepam and estazolam-were detected by full scan mode GC-MS. RT and RRT were analyzed according to combined uncertainty and expanded uncertainty.

RESULTS

The expanded uncertainty of RT and RRT were 6.0×10^-4-14.1×10^-3 and 2.5×10^-6-5.9×10^-5 （k=3）, respectively. The RT of poisons （drugs） was relatively stable in blood samples with different mass concentrations. Among dichlorvos, phorate, diazepam and estazolam, the absolute deviation and relative deviation of RT were ≤0.03 min and ≤0.4%, respectively, and those of RRT were ≤0.003 min and ≤0.3%, respectively.

CONCLUSIONS

The maximum allowable deviations of RT and RRT for common poisons （drugs） in blood samples are recommended to be ±0.05 min and ±0.5%.

[The comparison of clinical features and laboratory indexes between flat descending hearing loss and total hearing loss]

Objective:To discuss similarities and differences in clinical features and laboratory indexes between patients with flat descending type sudden hearing loss and those with total hearing loss. Method:The clinical data of 123 patients with full frequencies hearing loss were retrospectively analyzed. The differences in clinical features and laboratory tests(platelet, coagulation series, D-dimer, blood lipids, hemorheology) between patients with flat descending hearing loss and those with total hearing loss were analyzed by gender, age and ear side, treatment time, concomitant symptom (tinnitus, dizziness), original underlying diseases (hypertension, diabetes), etc. Result:In the clinical features,among 51 flat descending cases, the ratio of male and female was 2.401:1; among 72 total hearing loss cases, the ratio of men and women ratio was 1.058:1 (P<0.05). Among two groups of patients,the majority received treatment within 7 days, among whom 66.7% were flat descending population, and 83.3% were total hearing loss population (P<0.05). Flat descending population with dizziness only accounted for 35.3% while this figure was up to 70.8% when it came to total hearing loss patients (P<0.01). Two groups showed no differences in age, ear side, tinnitus, the original underlying diseases (hypertension, diabetes). In the laboratory tests, the total hearing loss population overtopped the plat descending population in PLT and PCT (P<0.05), while falling below the plat descending population in APTT (P<0.01). Two groups showed no differences in other indicators of platelet and coagulation series and laboratory data of D-dimer, blood lipids, hemorheology. Conclusion:Compared with flat descending sudden hearing loss, sudden total hearing loss more frequently happened to females who also were accompanied by dizziness. The treatment rate within 7 days was high and the patients with hypercoagulable state accounted for a higher proportion.

[Confirming Indicators of Qualitative Results by Chromatography-mass Spectrometry in Biological Samples]

Because of the exist of complex matrix, the confirming indicators of qualitative results for toxic substances in biological samples by chromatography-mass spectrometry are different from that in non-biological samples. Even in biological samples, the confirming indicators are different in various application areas. This paper reviews the similarities and differences of confirming indicators for the analyte in biological samples by chromatography-mass spectrometry in the field of forensic toxicological analysis and other application areas. These confirming indicators include retention time （RT）, relative retention time （RRT）, signal to noise （S/N）, characteristic ions, relative abundance of characteristic ions, parent ion-daughter ion pair and abundance ratio of ion pair, etc.

[A prospective control study of Saccharomyces boulardii in prevention of antibiotic-associated diarrhea in the older inpatients]

Objective: To study the value of Saccharomyces boulardii for the prevention of antibiotic-associated diarrhea in older inpatients. Methods: A total of 163 older patients who were treated with wide-spectrum antibiotics at least three days during January 2014 to December 2015 were randomly divided into control and study group. In study group, 81 patients were administrated with oral Saccharomyces boulardii 500 mg twice a day for 21 days. The control group was of no intervention. Morbidity rate of antibiotic-associated diarrhea and Clostridium difficile-associated diarrhea, frequency and duration of diarrhea were recorded. Results: The incidence of antibiotic-associated diarrhea in study group was significantly lower than that in control group [14.8%(12/81) vs 28.0%(23/82), P<0.05], whereas no difference was seen in the incidence of Clostridium difficile-associated diarrhea [3.7%(3/81) vs 4.9%(4/82), P>0.05] in two groups. The frequency and duration of diarrhea in the study group were significantly lower and shorter than those in control group[(4.3±1.7) times/day vs (6.9±2.0) times/day; (3.0±1.1) days vs (5.7±1.8) days, both P<0.01]. Conclusion:Saccharomyces boulardii may reduce the incidence of antibiotic-associated diarrhea therefore improving the symptom of diarrhea in older inpatients.

Effect of a high-concentrate diet on milk components and mammary health in Holstein dairy cows

In order to evaluate the milk yield, milk quality, and health of dairy cows fed a high-concentrate (HC) diet, eight lactating Holstein dairy cattle were randomly assigned to HC or low-concentrate (LC) diet groups and fed for 50 days, and the auto-control studying before and after treatment with the two diets was used. During the experiment, plasma and milk samples were collected and measured. With regard to milk component, HC feeding led to higher milk production (P < 0.05), but significantly lower milk protein percentage (P < 0.05), milk protein yield (P < 0.05), and milk fat percentage (P < 0.05) throughout the five periods than LC feeding. Milk somatic cell count and N-acetyl-D-glucosaminidase activity (P < 0.01) were higher than those observed under LC feeding. mRNA expression levels of interleukin-8 (IL-8), C-C motif chemokine ligand (CCL5), and lactalbumin alpha (α-LA) were investigated by qPCR and found to be significantly lower (P < 0.01) in cattle fed the HC diet. The amino acid content was analyzed by high performance liquid chromatography (HPLC), and the content of Asp (P < 0.01), Gln (P < 0.01), Ala (P < 0.05), Leu (P < 0.05), Lys (P < 0.05), and Ile (P < 0.01) was significantly lower in the HC group, whereas the content of Arg (P < 0.05) and Phe (P < 0.01) was significantly higher. These results suggest that the HC diet might have an important influence on mammary health. The amino acid content was lower, suggesting that depletion of amino acids, resulting in depleted milk protein, affects milk quality.

Antisense expression of Gossypium hirsutum UDP-glucuronate decarboxylase in Arabidopsis leads to changes in cell wall components

UDP-glucuronate decarboxylase (UDP-xylose synthase; UXS, EC 4.1.1.35) is an essential enzyme of the non-cellulosic polysaccharide biosynthetic pathway. In the present study, using transient expression of fluorescently labeled Gossypium hirsutum UXS (GhUXS3) protein in onion epidermal cells, we observed that this protein was distributed in the cytoplasm. The GhUXS3 cDNA of cotton was expressed in an antisense orientation in Arabidopsis thaliana by Agrobacterium tumefaciens-mediated transformation. Homozygous plants showing down-regulation of UXS were analyzed with northern blots. Compared to the untransformed control, transgenic plant showed shorter roots, earlier blossom formation, and delayed senescence. Biochemical analysis indicated that levels of rhamnose, mannose, galactose, glucose, xylose, and cellulose were reduced in some of the down-regulated antisense plants. These results suggest that GhUXS3 regulates the conversion of non-cellulosic polysaccharides and modulates their composition in plant cell walls. We also discuss a possible cellular function for GhUXS in determining the quality of cotton fibers.

Colorimetric detection of DNA damage by using hemin-graphene nanocomposites

A colorimetric method for detection of DNA damage was developed by using hemin-graphene nanosheets (H-GNs). H-GNs were skillfully synthesized by adsorping of hemin on graphene through π-π interactions. The as-prepared H-GNs possessed both the ability of graphene to differentiate the damage DNA from intact DNA and the catalytic action of hemin. The damaged DNA made H-GNs coagulated to different degrees from the intact DNA because there were different amount of negative charge exposed on their surface, which made a great impact on the solubility of H-GNs. As a result, the corresponding centrifugal supernatant of H-GNs solution showed different color in the presence of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2, which could be discriminated by naked eyes or by ultraviolet (UV)-visible spectrometer. Based on this, the damaged effects of styrene oxide (SO), NaAsO2 and UV radiation on DNA were studied. Results showed that SO exerted most serious damage effect on DNA although all of them damaged DNA seriously. The new method for detection of DNA damage showed good prospect in the evaluation of genotoxicity of new compounds, the maximum limit of pesticide residue, food additives, and so on, which is important in the fields of food science, pharmaceutical science and pesticide science.

Excitons emissions and Raman scattering of ZnO nanoparticles embedded in BaF2 matrices by reactive magnetron sputtering

ZnO nanoparticles embedded in BaF2 matrix were fabricated by rf magnetic sputtering technology. The optical properties of high quality ZnO nanoparticles, thermally post treated in a N2 atmosphere, were investigated by temperature-dependence photoluminescence measurement. Free exciton and localized exciton were observed at the low temperature. Free exciton peak was at 3.374 eV and localized exciton peak was at 3.420 eV, dominating the PL spectrum at 77 K. Free exciton transition was observed at 3.310 eV at room temperature, whereas the localized exciton transition was at 3.378 eV. The multiple-phonon Raman scattering spectrum showed that ZnO nanoparticles embedded in BaF2 matrix had a large deformation energy originated from lattice mismatch between ZnO and BaF2 matrix. Analysis of the fitting results from the temperature dependence of FWHM of ZnO exciton illustrated that the large value of gamma(ph) was good qualitative agreement with the large deformation potential.

Electronic properties of edge-functionalized zigzag graphene nanoribbons on SiO2 substrate

Based on first-principles calculations, electronic properties of edge-functionalized zigzag graphene nanoribbons (ZGNRs) on SiO(2) substrate are presented. Metallic or semiconducting properties of ZGNRs are revealed due to various interactions between edge-hydrogenated ZGNRs and different SiO(2)(0001) surfaces. Bivalent functional groups decorating ZGNRs serve as the bridge between active edges of ZGNRs and SiO(2). These functional groups stabilize ZGNRs on the substrate, as well as modify the edge states of ZGNRs and further affect their electronic properties. Bandgaps are opened owing to edge state destruction and distorted lattice in ZGNRs.

The pharmacokinetics of antofloxacin in renally impaired rats

Our aim was to investigate whether renal impairment induced by cisplatin altered the pharmacokinetics of antofloxacin. Antofloxacin (7.5 mg kg−1, i.v.) was given to normal or renally impaired rats (induced by cisplatin). Concentrations of antofloxacin in plasma and urine were measured using HPLC. Pharmacokinetic parameters were estimated. The plasma concentrations of antofloxacin in the renally impaired rats were significantly higher than those in the normal rats, accompanied by significant increase of the area under the plasma concentration-time curve (AUC) (968.78 ± 259.39 μg min mL−1 versus 509.84 ± 46.19 μg min mL−1 in normal rats P &lt; 0.05). The system clearance (CL) and renal clearance (CLR) of antofloxacin decreased from 12.66 ± 1.15 mL kg−1 min−1 and 3.21 ± 1.80 mLkg−1 min−1 in normal rats, to 6.63 ± 2.82 mLkg−1 min−1 and 0.31 ± 0.15 mLkg−1 min−1, respectively. No differences between two treatments in half-life and mean residence time were found. We concluded that renal impairment induced by cisplatin significantly altered the pharmacokinetics of antofloxacin and resulted in decrease of the renal elimination.

Morphologies of fibroblast cells cultured on surfaces of PHB films implanted by hydroxyl ions

Polyhydroxybutyrate (PHB) films were implanted with 40 keV hydroxyl ions with fluences ranging from 1 x 10(12) to 1 x 10(15) ions/cm2, respectively. The as-implanted PHB films were characterized by scanning electron microscopy (SEM), electron spectroscopy for chemical analysis (ESCA) and water contact angle measurements. The surface structures and properties of the as-implanted PHB films were closely related with hydroxyl ion fluence. They were further investigated by inoculating 3T6 fibroblasts cells on their surfaces. Morphologies of the 3T6 fibroblast cells cultured on surfaces of the as-implanted PHB films were observed by SEM. Characterization of the cultural 3T6 cells was analyzed qualitatively. The preliminary experimental results reveal that the bioactivity of the PHB films modified by hydroxyl ion implantation was improved at different levels, and the fluence of 1 x 10(13) ions/cm2 is optimal for PHB film.

Investigation of recombinant Schistosoma japonicum paramyosin fragments for immunogenicity and vaccine efficacy in mice

Schistosoma japonicum paramyosin, a 97 kDa myofibrillar protein, is a recognized vaccine candidate against schistosomiasis. To improve its expression and to identify protective epitopic regions on paramyosin, the published Chinese Schistosoma japonicum paramyosin cDNA sequence was redesigned using Pichia codon usage and divided into four overlapping fragments (fragments 1, 2, 3, 4) of 747, 651, 669 and 678 bp, respectively. These gene fragments were synthesized and expressed in Pichia pastoris (fragments 2 and 3) or E. coli (fragments 1 and 4). The recombinant proteins were produced at high level and purified using a two-step process involving Ni-NTA affinity chromatography and gel filtration. BALB/c mice were immunized subcutaneously three times at 2-week-intervals with the purified proteins formulated in adjuvant Quil A. The protein fragments were highly immunogenic, inducing high, though variable, ELISA antibody titres, and each was shown to resemble native paramyosin in terms of its recognition by the anti-fragment antibodies in Western blotting. The immunized mice were subjected to cercarial challenge 2 weeks after the final injection and promising protective efficacy in terms of significant reductions in worm burdens, worm-pair numbers and liver eggs in the vaccinated mice resulted. There was no apparent correlation between the antibody titres generated and protective efficacy, as all fragments produced effective but similar levels of protection.

[Specific antibodies against recombinant MSP1 of Plasmodium falciparum strongly inhibit the parasite growth in vitro]

In order to produce large amounts of protein for vaccine trials, a synthetic msp1-42 gene was inserted into Pichia pastoris expression vector and the plasmid was introduced into Pichia pastoris SMD1168 by electroporation. The expressed MSP1-42 was secreted into the protein-free medium. To measure the conformational properties of MSP1-42,16 monoclonal antibodies (11 recognizing conformational epitopes) were allowed to interact with the Pichia-derived MSP1-42, and all antibodies specific for conserved and K1 protype interacted with the protein. Interestingly, three monoclonal antibodies (e.g. 9.8, 13.1 and 7.3), that were shown not to interact with CHO-derived MSP1, could interact with the Pichia-derived MSP1-42. Rabbits were immunized with recombinant MSP1-42 formulated with CFA adjuvant four times. The rabbits were bled on the day 3 after last immunization, and total IgG isolated by protein A column from the immunized rabbits was shown to strongly inhibit the parasite growth in vitro dose-dependently, whereas IgG from rabbit with adjuvant had no inhibition.

[Effects of losartan on renal ultrastructure in diabetic rats]

OBJECTIVE

To observe the effects of losartan on renal ultrastructure in streptozotocin diabetic rats.

METHODS

Male SD rats were randomly divided into 2 groups: normal control group (NC group) and diabetic group. Diabetic group was induced by streptozocin (65 mg.kg-1) abdominal injection. Four weeks later, diabetic rats were further divided into 2 groups: diabetic rats treated with losartan (DL group, 20 mg.kg-1.d-1, by gavage) and diabetic unteated control group (DC group). Renal ultrastructure of each group was observed before and after 12 weeks of treatment respectively.

RESULTS

The ultrastructure alterations in DL group including mesangial expansion and thickening of glomerular basement membrane (GBM), were lighter than those in DC group.

CONCLUSION

Losartan can prevent renal pathological progress in diabetic rats. It is suggested that losartan may have some renal protective effects.

Mutation of conserved aspartates affect maturation of presenilin 1 and presenilin 2 complexes

Presenilin (PS1 and PS2) holoproteins are transiently incorporated into low molecular weight (MW) complexes. During subsequent incorporation into a higher MW complex, they undergo endoproteolysis to generate stable N- and C-terminal fragments (NTF/CTF). Mutation of either of two conserved aspartate residues in transmembrane domains inhibits both presenilin-endoproteolysis and the proteolytic processing of APP and Notch. We show that aspartate-mutant holoprotein presenilins are not incorporated into the high molecular weight, NTF/CTF-containing complexes. Aspartate-mutant presenilin holoproteins also preclude entry of endogenous wild-type PS1/PS2 into the high molecular weight complexes, but do not affect the incorporation of wild-type holoproteins into lower molecular weight holoprotein complexes. These data suggest that the loss-of-function aspartate-mutants cause altered PS complex maturation, and argue that the functional presenilin moieties are contained in the high molecular weight presenilin NTF/CTF-containing complexes.

[Study of diphacinone in biological samples by high performance liquid chromatography/diode array detector]

An analytical approach has been developed for high performance liquid chromatographic determination of diphacinone extracted from liver, blood, urine and kidney of rabbit by solid phase extraction (SPE) cartridges (using SAX, CN or SILICA GEL) with coumarin as the internal standard. Diphacinone was separated by reversed-phase gradient chromatography with DAD detection at 286 nm. The Analytical column was Hypersil BDS C18(150 mm x 4.6 mm i.d., 5 microns) and the guard column was Phenomenex ODS(4 mm x 3.0 mm i.d.). The mobile phase was a gradient mixture of aqueous solution (A) and methanol solution (B) both containing 0.5% ion pair A. There was a good linear relationship between the concentration of diphacinone and the ratio of peak areas of diphacinone and coumarin (internal standard) (r = 0.9999). The linear range was 1 mg/L-100 mg/L, and the lower detection limit was 5 ng (S/N = 3). The average recoveries of diphacinone in urine, blood and liver were 88.4% (n = 3, RSD = 1.25%, SPE by CN column), 82.2% (n = 3, RSD = 1.67%, SPE by SAX column), 91.0% (n = 3, RSD = 2.77%, SPE by SILICA GEL column), respectively.

Pharmacological models for inner ear therapy with emphasis on nitric oxide

Nitric oxide (NO)-mediated neurotoxicity may be an appropriate pathophysiological model with which to explain a variety of inner ear diseases characterized by acute or progressive hearing loss, tinnitus and vertigo. The localization of NO synthase (NOS) isoforms was examined in the inner ear of the pigmented guinea pig after intratympanic injection of 1 mg lipopolysaccharide (LPS) or 5 mg gentamicin (GM) using an immunohistochemical method, revealing the expression of NOS II in the inner ear. Production of NO in the isolated organ of Corti and utricle or in the isolated vestibular and cochlear hair cells after stimulation with L-arginine, glutamate, GM and LPS was investigated using the fluorescence indicator 4,5-diaminofluorescein diacetate. The fluorescence intensity of the sensory cells was augmented by stimulation with L-arginine, glutamate, GM and LPS. A significant increase in NO production was also noted in the LPS-treated animals. These findings imply that NO from constitutive NOS may mediate ototoxicity in the early phase, whereas NO from NOS II may contribute to the late phase of tissue damage in the inner ear. Based on this hypothesis, reduction of glutamatergic excitotoxicity and inhibition of NOS, scavenging superoxide and scavenging peroxynitrite are thought to attenuate NO-mediated otoneurotoxicity.

Carboxyl-terminal fragments of Alzheimer beta-amyloid precursor protein accumulate in restricted and unpredicted intracellular compartments in presenilin 1-deficient cells

Absence of functional presenilin 1 (PS1) protein leads to loss of gamma-secretase cleavage of the amyloid precursor protein (betaAPP), resulting in a dramatic reduction in amyloid beta peptide (Abeta) production and accumulation of alpha- or beta-secretase-cleaved COOH-terminal fragments of betaAPP (alpha- or beta-CTFs). The major COOH-terminal fragment (CTF) in brain was identified as betaAPP-CTF-(11-98), which is consistent with the observation that cultured neurons generate primarily Abeta-(11-40). In PS1(-/-) murine neurons and fibroblasts expressing the loss-of-function PS1(D385A) mutant, CTFs accumulated in the endoplasmic reticulum, Golgi, and lysosomes, but not late endosomes. There were some subtle differences in the subcellular distribution of CTFs in PS1(-/-) neurons as compared with PS1(D385A) mutant fibroblasts. However, there was no obvious redistribution of full-length betaAPP or of markers of other organelles in either mutant. Blockade of endoplasmic reticulum-to-Golgi trafficking indicated that in PS1(-/-) neurons (as in normal cells) trafficking of betaAPP to the Golgi compartment is necessary before alpha- and beta-secretase cleavages occur. Thus, although we cannot exclude a specific role for PS1 in trafficking of CTFs, these data argue against a major role in general protein trafficking. These results are more compatible with a role for PS1 either as the actual gamma-secretase catalytic activity or in other functions indirectly related to gamma-secretase catalysis (e.g. an activator of gamma-secretase, a substrate adaptor for gamma-secretase, or delivery of gamma-secretase to betaAPP-containing compartments).

Mutation of the conserved N-terminal cysteine (Cys92) of human presenilin 1 causes increased A beta42 secretion in mammalian cells but impaired Notch/lin-12 signalling in C. elegans

The presenilin proteins are involved in the proteolytic processing of transmembrane proteins such as Notch/lin-12 and the beta-amyloid precursor protein (betaAPP). Mutation of a conserved cysteine (Cys60Ser) in the C. elegans presenilin sel-12 has a loss-of-function effect on Notch/lin-12 processing similar to that of null mutations in sel-12. In contrast, in mammalian cells, most missense mutations increase gamma-secretase cleavage of betaAPP. We report here that mutation of this conserved cysteine (Cys92Ser) in human presenilin 1 confers a loss-of-function effect in C. elegans, but causes increased A beta42 secretion in mammalian cells. These data suggest that the role of presenilins in Notch/lin-12 signalling and betaAPP processing are either separately regulated activities or independent activities of the presenilins.

Nicastrin modulates presenilin-mediated notch/glp-1 signal transduction and betaAPP processing

Nicastrin, a transmembrane glycoprotein, forms high molecular weight complexes with presenilin 1 and presenilin 2. Suppression of nicastrin expression in Caenorhabditis elegans embryos induces a subset of notch/glp-1 phenotypes similar to those induced by simultaneous null mutations in both presenilin homologues of C. elegans (sel-12 and hop-1). Nicastrin also binds carboxy-terminal derivatives of beta-amyloid precursor protein (betaAPP), and modulates the production of the amyloid beta-peptide (A beta) from these derivatives. Missense mutations in a conserved hydrophilic domain of nicastrin increase A beta42 and A beta40 peptide secretion. Deletions in this domain inhibit A beta production. Nicastrin and presenilins are therefore likely to be functional components of a multimeric complex necessary for the intramembranous proteolysis of proteins such as Notch/GLP-1 and betaAPP.

Mutation of conserved aspartates affects maturation of both aspartate mutant and endogenous presenilin 1 and presenilin 2 complexes

Presenilin (PS1 and PS2) holoproteins are transiently incorporated into low molecular weight (MW) complexes. During subsequent incorporation into a higher MW complex, they undergo endoproteolysis to generate stable N- and C-terminal fragments. Mutation of either of two conserved aspartate residues in transmembrane domains inhibits both presenilin-endoproteolysis and the proteolytic processing of beta-amyloid precursor protein and Notch. We show that although PS1/PS2 endoproteolysis is not required for inclusion into the higher MW N- and C-terminal fragment-containing complex, aspartate mutant holoprotein presenilins are not incorporated into the high MW complexes. Aspartate mutant presenilin holoproteins also preclude entry of endogenous wild type PS1/PS2 into the high MW complexes but do not affect the incorporation of wild type holoproteins into lower MW holoprotein complexes. These data suggest that the loss of function effects of the aspartate mutants result in altered PS complex maturation and argue that the functional presenilin moieties are contained in the high molecular weight complexes.

Limited genetic susceptibility to severe Graves' ophthalmopathy: no role for CTLA-4 but evidence for an environmental etiology

Graves' disease (GD) is an autoimmune thyroid disease (AITD) characterized by hyperthyroidism and by the occurrence of a distinctive ophthalmopathy (orbitopathy), which presents with varying degrees of severity. Graves' disease clusters in families but the importance of heredity in the pathogenesis of the associated ophthalmopathy is unclear. We have studied the family history of 114 consecutive, ethnically mixed patients with severe Graves' ophthalmopathy (GO). Patients were selected by unambiguous single ascertainment. Seventy-seven percent of patients were female and 59% smoked. The mean age at onset of their GD was 43 years (range 17-78 years). Forty-one patients (36%) had a family history of AITD, defined as a first- and/or a second-degree relative affected with either Graves' disease (GD) or Hashimoto's thyroiditis (HT). The segregation ratio for AITD in nuclear families in our ascertained Graves' ophthalmopathy families was 0.07 (0.12 in Caucasians only). Hence, the higher prevalence of AITD among relatives of Graves' ophthalmopathy patients agreed with the known genetic predisposition to AITD and this predisposition was stronger in women than in men. However, only 3 of the 114 patients had a family history of severe Graves' ophthalmopathy (all second-degree relatives) and the segregation ratio for GO was 0. These data did not support a major role for familial factors in the development of severe Graves' ophthalmopathy distinct from Graves' disease itself. In addition, we tested 4 candidate genes, human leukocyte antigen (HLA), tumor necrosis factor-beta (TNF-beta), CTLA-4 and the thyrotropin receptor (TSHR), for association with Graves' ophthalmopathy. These were negative except for the HLA and CTLA-4 genes, which were found to be weakly associated with GO giving similar relative risk (RR) as in GD patients without ophthalmopathy. These data suggested that environmental factors, rather than major genes, were likely to predispose certain individuals with AITD to severe Graves' ophthalmopathy. Smoking remains one example of such potential external insults.

Lipopolysaccharide-induced expression of inducible nitric oxide synthase in the guinea pig organ of Corti

The purpose of the investigation was to ascertain whether inoculation of bacterial lipopolysaccharide (LPS) into the cochlea of the guinea pig could elicit formation of inducible nitric oxide synthase (iNOS). Immunohistochemical study revealed that immunoreactivity to iNOS was seen below outer hair cells representing nerve fibers and synaptic nerve endings. iNOS-staining could also be observed in phalangeal dendrites of Deiter's cells pointing to the cuticular membrane, Hensen's cells and on stria vascularis 48 h after inoculation with LPS. Immunohistochemical investigation with a specific anti-nitrotyrosine antibody also revealed intense immunoreactivity identical to that of iNOS, suggesting formation of peroxynitrite in the organ of Corti by the reaction of NO with O(2)(-). On the basis of these findings, it can be concluded that NO together with O(2)(-), which form the more reactive peroxynitrite, are the most important pathogenic agents in LPS-induced damage of cochlea in the guinea pig.

Localization of soluble guanylate cyclase activity in the guinea pig inner ear

The aim of this study was to characterize the nitric oxide (NO) receptor soluble guanylate cyclase (sGC), to determine the cells targeted by NO and to elucidate the function of the NO/cGMP pathway in the inner ear. sGC activity in the inner ear was localized by immunohistochemical detection of NO-stimulated cGMP. Soluble guanylate cyclase activity in the cochlea was detected in the nerve endings underneath the outer and inner hair cells, supporting cells, stria vascularis and vessels. In the vestibular organs, sGC activity was detected in the cytoplasm of sensory cells, nerve fibres, dark cells and transitional cells and vessels. These findings suggest that the NO/cGMP pathway may be involved in regulatory processes in neurotransmission, blood flow and inner ear fluid homeostasis.

Presenilins interact with armadillo proteins including neural-specific plakophilin-related protein and beta-catenin

Missense substitutions in the presenilin 1 (PS1) and presenilin 2 (PS2) proteins are associated with early-onset familial Alzheimer's disease. We have used yeast-two-hybrid and coimmunoprecipitation methods to show that the large cytoplasmic loop domains of PS1 and PS2 interact specifically with three members of the armadillo protein family, including beta-catenin, p0071, and a novel neuronal-specific armadillo protein--neural plakophilin-related armadillo protein (NPRAP). The PS1:NPRAP interaction occurs between the arm repeats of NPRAP and residues 372-399 at the C-terminal end of the large cytoplasmic loop of PS1. The latter residues contain a single arm-like domain and are highly conserved in the presenilins, suggesting that they form a functional armadillo protein binding site for the presenilins.

Presenilin mutations associated with Alzheimer disease cause defective intracellular trafficking of beta-catenin, a component of the presenilin protein complex

The presenilin proteins are components of high-molecular-weight protein complexes in the endoplasmic reticulum and Golgi apparatus that also contain beta-catenin. We report here that presenilin mutations associated with familial Alzheimer disease (but not the non-pathogenic Glu318Gly polymorphism) alter the intracellular trafficking of beta-catenin after activation of the Wnt/beta-catenin signal transduction pathway. As with their effect on betaAPP processing, the effect of PS1 mutations on trafficking of beta-catenin arises from a dominant 'gain of aberrant function' activity. These results indicate that mistrafficking of selected presenilin ligands is a candidate mechanism for the genesis of Alzheimer disease associated with presenilin mutations, and that dysfunction in the presenilin-beta-catenin protein complexes is central to this process.

[Biological effects of space flight on purple nonsulfur photosynthetic bacteria]

OBJECTIVE

To study biological effects of space flight on purple nonsulfur photosynthetic bacteria.

METHODS

Two purple nonsulfur photosynthetic bacteria, Rhodopseudomonas palustris H3 and Rhodobacter sphaeroides ZGY, were carried on satellite for 15 days and some of their biological effects were studied after recovery.

RESULTS

In space condition, survival rate of bacteria was promoted. The purification of organic wastewater, removal of nitrite, degradation of phenol and decolorization of acid red B were enhanced, and the resistance of both strains to medicine was stable.

CONCLUSION

The major morphological and physiological characteristics of loaded strains H3-S and ZGY-S were not changed after space flight.

The presenilin 1 protein is a component of a high molecular weight intracellular complex that contains beta-catenin

The presenilin (PS) genes associated with Alzheimer disease encode polytopic transmembrane proteins which undergo physiologic endoproteolytic cleavage to generate stable NH2- and COOH-terminal fragments (NTF or CTF) which co-localize in intracellular membranes, but are tightly regulated in their stoichiometry and abundance. We have used linear glycerol velocity and discontinuous sucrose gradient analysis to investigate the distribution and native conformation of PS1 and PS2 during this regulated processing in cultured cells and in brain. The PS1 NTF and CTF co-localize in the endoplasmic reticulum (ER) and in the Golgi apparatus, where they are components of a approximately 250-kDa complex. This complex also contains beta-catenin but not beta-amyloid precursor protein (APP). In contrast, the PS1 holoprotein precursor is predominantly localized to the rough ER and smooth ER, where it is a component of a approximately 180-kDa native complex. PS2 forms similar but independent complexes. Restricted incorporation of the presenilin NTF and CTF along with a potentially functional ligand (beta-catenin) into a multimeric complex in the ER and Golgi apparatus may provide an explanation for the regulated accumulation of the NTF and CTF.