Effects of Breathing Patterns on Amide Proton Transfer MRI in the Kidney: A Preliminary Comparative Study in Healthy Volunteers and Patients With Tumors

BACKGROUND

The amide proton transfer-weighted (APTw) imaging for kidney diseases is important. However, the breathing patterns on APTw imaging remains unexplored.

PURPOSE

This study aimed to investigate the effects of intermittent breath-hold (IBH) and free breathing (FB) on renal 3D-APTw imaging.

STUDY TYPE

Healthy volunteers were enrolled prospectively, and renal clear cell carcinoma (RCCC) patients were included retrospectively.

POPULATION

58 healthy volunteers and 10 RCCC patients.

FIELD STRENGTH/SEQUENCE

3-T, turbo spin echo, and fast field echo.

ASSESSMENT

3D-APTw imaging was scanned using the IBH and FB methods in volunteers and using the IBH method in RCCC patients. The image quality was evaluated by three observers according to the 5-point Likert scale. Optimal images rated at three points or higher were used to measure the APT values.

STATISTICAL ANALYSIS

The measurement repeatability was assessed using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. The APT values were analyzed using McNemar's test, one-way analysis of variance, and t test.

RESULTS

50 healthy volunteers and 8 RCCC patients were enrolled. Renal 3D-APTw imaging using the IBH method revealed a higher success rate (88% vs 78%). The ICCs were excellent in the IBH group (ICCs > 0.74) and were good in the FB group (ICCs < 0.74). No significant differences in the APT values among various zones using the IBH (P = 0.263) or FB method (P = 0.506). The mean APT value using the IBH method (2.091% ± 0.388%) was slightly lower than the FB method (2.176% ± 0.292%), but no significant difference (P = 0.233). The APT value of RCCC (4.832% ± 1.361%) was considerably higher than normal renal using the IBH method.

CONCLUSIONS

The study demonstrated that the IBH method substantially increased the image quality of renal 3D-APTw imaging. Furthermore, APT values may vary between normal and tumor tissues.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

[Progress in the application of laparoscopic and endoscopic cooperative surgery in gastrointestinal stromal tumors]

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor among gastrointestinal tumors, with an inherent potential for malignancy. The primary approach to addressing GIST remains surgical intervention. Laparoscopic and endoscopic cooperative surgery (LECS) has emerged as an innovative treatment approach for GIST. LECS includes various techniques, such as classic LECS, inverted LECS, and laparoscopic-assisted endoscopic full-thickness resection, all of which aim to combine the advantages of laparoscopy and endoscopy. This treatment offers benefits such as accurate localization, complete lesion removal, and a good prognosis. Generally, LECS can be used for GIST with a tumor diameter less than 50 mm, which cannot be completely removed through traditional endoscopic surgery. The clinical application of LECS deserves further exploration and expansion in the future, ultimately benefiting patients.

[Epidemiological investigation on the local epidemic situation in Zhengzhou High-Tech Zone caused by SARS-CoV-2 Delta variant]

This study collected epidemic data of COVID-19 in Zhengzhou from January 1 to January 20 in 2022. The epidemiological characteristics of the local epidemic in Zhengzhou High-tech Zone caused by the SARS-CoV-2 Delta variant were analyzed through epidemiological survey and big data analysis, which could provide a scientific basis for the prevention and control of the Delta variant. In detail, a total of 276 close contacts and 599 secondary close contacts were found in this study. The attack rate of close contacts and secondary close contacts was 5.43% (15/276) and 0.17% (1/599), respectively. There were 10 confirmed cases associated with the chain of transmission. Among them, the attack rates in close contacts of the first, second, third, fourth and fifth generation cases were 20.00% (5/25), 17.86% (5/28), 0.72% (1/139) and 14.81% (4/27), 0 (0/57), respectively. The attack rates in close contacts after sharing rooms/beds, having meals, having neighbor contacts, sharing vehicles with the patients, having same space contacts, and having work contacts were 26.67%, 9.10%, 8.33%, 4.55%, 1.43%, and 0 respectively. Collectively, the local epidemic situation in Zhengzhou High-tech Zone has an obvious family cluster. Prevention and control work should focus on decreasing family clusters of cases and community transmission.

[Determination of chlorobenzene metabolite-p-chlorophenol in urine by solid phase extraction-gas chromatography]

Objective: A method to determine chlorobenzene metabolite-p-chlorophenol in urine by solid phase extraction-gas chromatography was established. Methods: In May 2021, the urine sample was hydrolyzed at 100 ℃ for 1.5 h with 2 ml concentrated hydrochloric acid. After cooling and filtering, the sample was enriched and purified by Oasis(®)MAX 6cc SPE column. Drip washing with 0.01 mol/L hydrochloric acid solution and elution with acetonitrile, the eluent was volumized to 5 ml with acetonitrile and determined by gas chromatography, and quantify by standard curve method. Results: Calibration curve of the method was linear within the range of 1.61-80.30 μg/ml and showed good linearity with r=0.9997, the regression equation was y=1.51602x-0.10234. The determination limit was 0.17 μg/ml, and the limit of quantitation was 0.55 μg/ml. Recovery rates were between 89.3%-104.4%, the relative standard deviation (RSD) of intra-day measurements ranged from 4.3% to 6.7%, and the RSD of inter-day measurements ranged from 4.5% to 6.7%. Conclusion: This method could optimize sample pretreatment, and eliminate the interference of impurities, which is sensitive, efficient and accurate for the determination of chlorobenzene metabolite-p-chlorophenol in urine.

[Time to initial diagnosis of imported malaria and its influencing factors in Jiangsu Province]

OBJECTIVE

To investigate the health-seeking behaviors of imported malaria cases after returning to China, and to investigate the factors affecting the time to initial diagnosis, so as to provide the scientific evidence for early identification of imported malaria cases and prevention of severe cases development and secondary transmission.

METHODS

The individual demographic features, and the disease onset and the time to initial diagnosis of imported malaria cases in Jiangsu Province in 2019 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China. The characteristics of health-seeking behaviors and epidemiological features of imported malaria cases were descriptively analyzed, and the factors affecting the time to initial diagnosis of imported malaria cases after returning to China were identified using multivariate logistic regression analysis.

RESULTS

A total of 244 imported malaria cases were reported in Jiangsu Province in 2019, and the time to initial diagnosis of the cases were 1-12 days, with mean time of (1.53 ± 1.65) days, with median time of one day. The highest number of malaria cases seeking healthcare services were found on the day of developing primary symptoms (76 cases, 31.1%), followed by on the second day (68 cases, 27.9%), on the third day (46 cases, 18.9%), and 54 cases (22.1%) received initial diagnosis 3 days following presence of primary symptoms, including 3 cases with initial diagnosis at more than one week. High proportions of imported malaria cases with a delay in the time to initial diagnosis were seen in migrant workers who returned to China in January (14 cases, 5.7%) and December (13 cases, 5.3%) and those aged between 41 and 50 years (32 cases, 13.1%). Multivariate logistic regression analysis showed relative short time to initial diagnosis among imported malaria cases returning to China on March [odds ratio (OR) = 0.16, P = 0.03, 95% confidence interval (CI): (0.03, 0.85)] and those with a history of overseas malaria parasite infections [OR = 0.36, P = 0.001, 95% CI: (0.19, 0.67)].

CONCLUSIONS

Timely health-seeking behaviors should be improved among imported malaria cases in Jiangsu Province, patients with a history of overseas malaria infections require faster health-seeking activities.

[Clinical characteristics of paroxysmal nocturnal hemoglobinuria (PNH) complicated with ischemic bowel disease]

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired hematopoietic stem cell disease. Gastrointestinal involvement is rarely seen in PNH. This study aims to analyze the clinical features in PNH patients complicated with ischemic bowel disease. Clinical date of 6 patients were collected at Peking Union Medical College Hospital from January 2010 to December 2020. The clinical manifestations, laboratory tests,imaging, endoscopic,and histopathological features and treatment were analyzed.Five in 6 patients were men, with a median age of 31 years old at onset. Most of disease course were recurrent episodes of chronic disease, with abdominal pain (5/6) and gastrointestinal bleeding (5/6). Laboratory examinations showed pancytopenia, reticulocytosis, elevated serum lactate dehydrogenase, high D-dimer and C-reactive protein levels in all patients. Multiple segments of small intestine were the most commonly involved and colon was also affected. Abdominal CT scan showed thickening and roughness or exudation of the intestinal wall (6/6), increased mesenteric density or "comb sign"(4/6), and cholestasis or gallbladder stones (5/6). Endoscopic manifestations included irregular shallow ulcers in the annular cavity (5/6), swelling mucosa with well-defined margins (6/6). Pathological biopsy revealed chronic inflammation of mucosa. The efficacy of steroids combined with anticoagulant therapy was better than that of steroids alone. Ischemic bowel disease in PNH patients is different from typical ischemic enteritis. Young patients, involvement of intestine with multiple segments are common characteristics. The anticoagulant is an essential agent for these patients.

[Retrospective analysis of infliximab in the treatment of Kawasaki disease]

Objective: To investigate the efficacy and safety of infliximab (IFX) therapy for children with Kawasaki disease. Methods: Sixty-eight children with Kawasaki disease who received IFX therapy in Children's Hospital of Fudan University from January 2014 to April 2021 were enrolled. The indications for IFX administration, changes in laboratory parameters before and after IFX administration, response rate, drug adverse events and complications and outcomes of coronary artery aneurysms (CAA) were retrospectively analyzed. Comparisons between groups were performed with unpaired Student t test or Mann-Whitney U test or chi-square test. Results: Among 68 children with Kawasaki disease, 52 (76%) were males and 16 (24%) were females. The age of onset was 2.1 (0.5, 3.8) years. IFX was administered to: (1) 35 children (51%) with persistent fever who did not respond to intravenous immunoglobulin (IVIG) or steroids, 28 of the 35 children (80%) developed CAA before IFX therapy; (2) 32 children (47%) with continuous progression of CAA; (3) 1 child with persistent arthritis. In all cases, IFX was administered as an additional treatment (the time from the onset of illness to IFX therapy was 21 (15, 30) days) which consisted of second line therapy in 20 (29%), third line therapy in 20 (29%), and fourth (or more) line therapy in 28 (41%). C-reactive protein (8 (4, 15) vs. 16 (8, 43) mg/L, Z=-3.38, P=0.001), serum amyloid protein A (17 (10, 42) vs. 88 (11, 327) mg/L, Z=-2.36, P=0.018) and the percentage of neutrophils (0.39±0.20 vs. 0.49±0.21, t=2.63, P=0.010) decreased significantly after IFX administration. Fourteen children (21%) did not respond to IFX and received additional therapies mainly including steroids and cyclophosphamide. There was no significant difference in gender, age at IFX administration, time from the onset of illness to IFX administration, the maximum coronary Z value before IFX administration, and the incidence of systemic aneurysms between IFX-sensitive group and IFX-resistant group (all P>0.05). Infections occurred in 11 cases (16%) after IFX administration, including respiratory tract, digestive tract, urinary tract, skin and oral infections. One case had Calmette-Guérin bacillus-related adverse reactions 2 months after IFX administration. All of these adverse events were cured successfully. One child died of CAA rupture, 6 children were lost to follow up, the remaining 61 children were followed up for 6 (4, 15) months. No CAA occurred in 7 children before and after IFX treatment, while CAA occurred in 54 children before IFX treatment. CAA regressed in 23 (43%) children at the last follow-up, and the diameter of coronary artery recovered to normal in 10 children. Conclusion: IFX is an effective and safe therapeutic choice for children with Kawasaki disease who are refractory to IVIG or steroids therapy or with continuous progression of CAA.

[Epidemiological characteristics of imported Plasmodium ovale malaria in Jiangsu Province from 2012 to 2020]

OBJECTIVE

To analyze the epidemiological characteristics of imported cases with Plasmodium ovale infections in Jiangsu Province from 2012 to 2020, so as to provide insights into the development of the imported malaria control strategy in the province.

METHODS

All data pertaining to cases with definitive diagnosis of P. ovale malaria in Jiangsu Province from 2012 to 2020 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China, including the date of going abroad and returning to China, time of malaria infections overseas, date of malaria onset, initial diagnosis and definitive diagnosis. All data pertaining to epidemic status were descriptively analyzed.

RESULTS

A total of 347 cases of P. ovale malaria were reported in Jiangsu Province from 2012 to 2020, with the highest number seen in 2015 (71 cases). All cases were laboratory-confirmed overseas imported malaria cases, accounting for 14.32% of all reported malaria cases in Jiangsu Province during the period from 2012 to 2020. The 5 cities with the highest number of imported P. ovale malaria cases included Lianyungang City (53 cases, 15.27%), Nantong City (44 cases, 12.68%), Huai'an (44 cases, 12.68%), Taizhou City (44 cases, 12.68%) and Yangzhou City (36 cases, 10.37%). The highest number of imported P. ovale malaria cases was reported in October (39 cases, 11.24%), and the lowest number was seen in December (21 cases, 6.05%). P. ovale infections mainly occurred in were Equatorial Guinea (97 cases, 37.95%), Angola (60 cases, 17.29%) and Nigeria (40 cases, 11.53%). The median duration between returning to China and malaria onset was 64 (144) days, and 7.49% (26/347) of all cases developed malaria one year after returning to China. The initial diagnosis of P. ovale malaria was mainly made at county-level medical institutions (117 cases, 33.72%), and the definitive diagnosis was mainly made at city-level medical institutions (122 cases, 35.16%). The correct rate of initial diagnosis of P. ovale malaria increased from 0 in 2012 to 78.26% in 2020, appearing a tendency towards a rise year by year (χ² = 50.90, P < 0.01).

CONCLUSIONS

Imported P. ovale malaria cases were reported in Jiangsu Province each year from 2012 to 2020, and P. ovale infections predominantly occurred in Africa. Initial and definitive diagnoses of P. ovale malaria were mainly made at city- and county-level medical institutions. Training on the detection ability of malaria parasites is recommended among grassroots microscopists to improve the diagnostic ability of P. ovale malaria, and consolidate the achievements of malaria elimination in Jiangsu Province.

[Determination of chloroacetic acid in workplace air by silanization-gas chromatography]

Objective: A method to determine acrylic acid in workplace air was developed by silanization-gas chromatography. Methods: In March 2020, chloroacetic acid in air were absorbed by silica gel tube, the samples were dried, then were desorbed and silanized by acetonitrile: N, O-bis (trimethylsilane) trifluoroacetamide (2∶1, V/V) at room temperature, allowed quantitative analysis of chloroacetic acid as its silanization product by gas chromatography. Results: Calibration curve of the method was linear within the range 0-162.8 μg/ml and showed good linearity with linear equation: y=0.011 8x, r=0.999 7. The determination limit of the method was 0.8 μg/ml, and the minimum detection concentration was 0.05 mg/m(3) (collect 15 L air) . The relative standard deviation (RSD) was 0.5%-1.3% (n=5) . Recoveries were between 98.6%-101.2%. Conclusion: The results prove silanization-gas chromatography is an accurate, simple and high sensitive method for determining chloroacetic acid in workplace air.

[Epidemic situation of malaria in Jiangsu Province in 2019]

OBJECTIVE

To analyze the epidemic situation of malaria in Jiangsu Province in 2019, so as to provide the scientific basis for the development of the strategy for the prevention of re-introduction of imported malaria.

METHODS

The malaria case report information, epidemiological case investigation information, epidemic foci investigation and management report in Jiangsu Province in 2019 were collected, and all epidemiological data were descriptively analyzed.

RESULTS

A total of 244 malaria cases were reported in Jiangsu Province in 2019, and all cases were laboratory-confirmed overseas imported cases, including 4 cases with vivax malaria, 206 cases with falciparum malaria, 12 cases with malariae malaria and 22 cases with ovale malaria. In 2019, there were 12 malaria cases progressing into severe cases in Jiangsu Province, with one death. Nanjing, Nantong, Lianyungang, Taizhou and Changzhou cities contributed the largest number of malaria cases in 2019, with the number of malaria cases accounting for 59.84% of total cases in Jiangsu Province. The infections occurred in Papua New Guinea (2 cases), Pakistan (1 case) and 27 African countries (241 cases), including Angola, the Democratic Republic of the Congo, Nigeria, Equatorial Guinea, Cote d'Ivoire and so on. There were 77 cases (31.55%) with a visit to doctor on the day of onset, and 146 cases (59.84%) within 1 to 3 days after onset. In addition, there were 149 cases (61.06%) with definitive diagnosis at the first visit and 77 cases (31.55%) diagnosed within 1 to 3 days after the visit, and the mean duration from the visit to definitive diagnosis was (0.80 ± 1.59) d, which significantly shortened as compared to that (1.34 d ± 2.59 d) in 2018 (U = 2.53, P < 0.05).

CONCLUSIONS

Intensifying the surveillance and management of imported malaria and improving the diagnostic capability of imported malaria and the treatment of severe malaria cases are required to consolidate the achievements of malaria elimination in Jiangsu Province.

Construction of SNP-STR Multiplex Amplification System with Genetic Markers and Its Forensic Application

Abstract

Objective To select and develop a SNP-STR multiplex amplification system with genetic markers compatible with current STR databases. To understand its genetic polymorphisms in Sichuan Han population and its application value in DNA mixture analysis. Methods Based on the STR genetic markers in commercial kits, SNPs adjacent to these STR markers were selected to be SNP-STR genetic markers. A SNP-STR multiplex amplification system with genetic markers based on allele-specific amplification was constructed using allele-specific amplification primers. The genetic polymorphism of the system in the Sichuan Han population was investigated and the efficiency of systems with different numbers of loci to detect the two individual DNA mixture samples was evaluated. Results An allele-specific multiplex amplification system constituted of 13 SNP-STR genetic markers was selected and constructed. In Sichuan Han population, the heterozygosity of each locus ranged from 0.76 to 0.88, and the combined discrimination power reached 0.999 999 999 999 999 968. In the analysis of the two individual DNA mixture samples： for single-locus amplification, the genotype of the minor components can still be detected when the mixture ratio reaches 1 000∶1; for multiple loci multiplex amplification, the maximum mixture ratio can reach 500∶1. As the number of loci in the system increased, the detection efficiency of the minor components in the DNA mixture decreased. Conclusion SNP-STR genetic markers have a higher polymorphism than STR. The multiplex amplification system made of SNP-STR genetic markers has a better analysis efficiency for mixed samples than traditional STR multiplex amplification system.

[Epidemic situation of malaria in Jiangsu Province in 2018]

OBJECTIVE

To analyze the epidemic situation of malaria in Jiangsu Province in 2018, so as to provide scientific evidence for formulating post-elimination malaria surveillance schemes and technical measures in Jiangsu Province.

METHODS

The malaria case report cards, epidemiological individual investigation forms of malaria cases and foci data were collected from Jiangsu Province in 2018, and the epidemic situation of malaria was descriptively analyzed.

RESULTS

A total of 243 malaria cases were reported in Jiangsu Province in 2018, which increased by 1.67% in relative to in 2017 (239 cases), and these cases included 171 cases with falciparum malaria, 14 cases with vivax malaria, 15 cases with quartan malaria, 42 cases with ovale malaria and a case with mixed infection of P. vivax and P. ovale. All cases were overseas imported, and no local secondary cases were found. The malaria cases were predominantly workers (76.54%). Nantong City (48 cases), Yangzhou City (33 cases) and Taizhou City (22 cases) were the most 3 cities with the largest number of malaria cases across Jiangsu Province. The malaria infections predominantly occurred in African areas (96.30%), and the other 9 cases had infections in Asia (8 cases) and Central America (1 case). There were 125 cases (51.44%) and 91 cases (37.45%) with definitive diagnosis at the day of admission and within 1 to 3 days post-admission, respectively. The percentages of definitive diagnosis at initial diagnosis were 48.27%, 88.76% and 97.30% at township-, county- and city-level medical institutions, respectively, and the percentage of definitive diagnosis at initial diagnosis was significantly lower in township-level medical institutions than in county- (χ² = 21.47, P < 0.01) and city-level medical institutions (χ² = 32.86, P < 0.01).

CONCLUSIONS

There are no local malaria cases in Jiangsu Province; however, the number of overseas imported malaria cases remains high in China. In the future, improving the post-elimination malaria surveillance system, enhancing the awareness of malaria prevention and control knowledge among high-risk populations, increasing the diagnostic capability of malaria in medical institutions, and improving the management of imported malaria cases should be performed to consolidate the achievements of malaria elimination.

Distinct effects of antihypertensives on depression in the real-world setting: A retrospective cohort study

BACKGROUND

Evidence is increasing that pathways of antihypertensives may have a role in the pathogenesis of depression. However, how the class of antihypertensives affects depression risk remains unclear.

METHODS

The effects of different classes of antihypertensives on depression were explored using an insurance database in Beijing, China. Antihypertensives in our study included calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), beta-blockers (BBs), and diuretics (DIUs). Those initially treated with only one class of antihypertensives were included. Stratified analysis was conducted for demographic characteristics, comorbidities, and statin prescriptions.

RESULTS

In total, 181,709 newly detected hypertension patients were included. The median follow-up period was 4.33 years and 19,030 participants were with depression by the end. After adjusting for covariates, the incidence density (95% confidence interval, CI) of depression in the BB, ACEI, DIU, CCB, and ARB groups was 3.16 (2.98-3.33), 3.10 (2.91-3.29), 2.70 (2.45-2.94), 2.67 (2.53-2.81), and 2.30 (2.16-2.43) per 100 person-years, respectively. Compared with ARB group, the hazard ratio (95% CI) of depression for BB, ACEI, DIU, and CCB group was 1.37 (1.32-1.43), 1.35 (1.28-1.42), 1.17 (1.08-1.27), and 1.16 (1.12-1.21), respectively. Stratified analysis suggested the highest depression ID remained within the BB or ACEI group.

LIMITATIONS

Detailed clinical information was unavailable, which may introduce bias. Patients on monotherapy as initial treatment were included and caution is needed for extrapolation.

CONCLUSIONS

Compared with ARBs, there may be a class effect of other antihypertensives on the risk of depression.

Comprehensive transcriptome analysis of faba bean in response to vernalization

This study unravels the transcriptional response of a highly productive faba bean cultivar under vernalization treatment. Faba bean (Vicia faba L.) is a member of the Leguminosae family and an important food crop worldwide providing valuable nutrients for humans. However, genome-wide studies and comprehensive sequencing resources of faba bean remain limited. Vernalization is crucial for enhanced yields in a number of winter-sown crops. However, the effects of vernalization on faba bean remain unknown. In this study, we generated a high-quality transcriptome assembly and functional annotation source for vernalized faba bean (Vicia faba L.) cv. Tongxian-2, a domesticated cultivar from southern China. A total of 369.9 million clean Illumina paired-end RNA-Seq reads were generated, and the transcriptome was assembled into 68,683 unigene sequences, with an average length of 1018 bp and an N50 of 1652 bp. Comprehensive functional annotation provided putative functional descriptions for more than 70% of the faba bean transcripts. We annotated a total of 1560 faba bean transcripts encoding transcription factors (TFs) belonging to 55 distinct TF families. The bHLH (168 transcripts), ERF (123 transcripts) and WRKY (105 transcripts) contained the largest number of TFs in response to vernalization. Genome-wide transcript changes comparing vernalized and unvernalized seedlings were investigated using bioinformatics approaches, which revealed a strong repression of photosynthesis and carbon metabolism, while genes participating in 'response to stress' were significantly induced. We also specifically identified vernalization-induced twenty-two 'pollen-pistil interaction' genes. A detailed functional annotation and expression profile analyses unveiled a number of protein kinases, which were specifically induced in vernalized seedlings. We also identified a total of 6852 simple sequence repeats (SSRs) in 6552 transcripts, representing a valuable genomic molecular marker resource for faba bean. In summary, this study provides new insights into the vernalization process in this economically valuable crop. The transcriptome data obtained provides us with a valuable candidate gene resource for future functional and molecular breeding studies. These data will contribute to the genome annotation for ensuing genome projects.

Alternative splicing and translation play important roles in hypoxic germination in rice

Post-transcriptional mechanisms (PTMs), including alternative splicing (AS) and alternative translation initiation (ATI), may explain the diversity of proteins involved in plant development and stress responses. Transcriptional regulation is important during the hypoxic germination of rice seeds, but the potential roles of PTMs in this process have not been characterized. We used a combination of proteomics and RNA sequencing to discover how AS and ATI contribute to plant responses to hypoxia. In total, 10 253 intron-containing genes were identified. Of these, ~1741 differentially expressed AS (DAS) events from 811 genes were identified in hypoxia-treated seeds compared with controls. Over 95% of these were not present in the list of differentially expressed genes. In particular, regulatory pathways such as the spliceosome, ribosome, endoplasmic reticulum protein processing and export, proteasome, phagosome, oxidative phosphorylation, and mRNA surveillance showed substantial AS changes under hypoxia, suggesting that AS responses are largely independent of transcriptional regulation. Considerable AS changes were identified, including the preferential usage of some non-conventional splice sites and enrichment of splicing factors in the DAS data sets. Taken together, these results not only demonstrate that AS and ATI function during hypoxic germination but they have also allowed the identification of numerous novel proteins/peptides produced via ATI.

[A Meta-analysis on the relations between short-term exposure to PM(2.5) and both mortality and related emergency visits in China]

Objective: To carry out a quantitative estimate that related to the effects of short-term exposure to PM(2.5) on all-cause mortality and emergency visits in China by using the systematic review and Meta-analysis. Methods: We selected all the studies published before March 2018 from China National Knowledge Infrastructure, Wanfang database, PubMed and EMBASE and data on relative risk (RR), excess risk (ER) and their 95%CIs: appeared in these papers were extracted. According to the differences in the size or direction (heterogeneity) of the results, we computed summary estimates of the effect values using a random-effect or fixed effect model. We also conducted the subgroup analysis and Meta-analysis to have assessed the selected studies for the evidence of study bias. Results: A total of 33 original studies, indexed in databases, were identified. Among those studies, 39 sets of data on mortality and 4 sets of data on emergency were valid to show that within the daily concentration range from 47.7 to 176.7 μg/m(3), for 10 μg/m(3) increases in PM(2.5) concentrations, it would increase the daily numbers of deaths by 0.49% (95%CI: 0.39%-0.59%) and 0.30% (95%CI: 0.10%-0.51%) for all-cause deaths and all-cause emergency-room visits, respectively. For subgroup analysis, the combined effect of PM(2.5) in causing short-term all-cause deaths in the northern areas (ER=0.42%, 95%CI: 0.30%-0.54%) seemed lower than that in the southern areas (ER=0.63%, 95%CI: 0.44%-0.82%). The combined effect of PM(2.5) concentration below 75 μg/m(3) (ER=0.50%, 95%CI: 0.37%-0.62%) was higher than that of PM(2.5) concentration ≥75 μg/m(3) (ER=0.39%, 95%CI: 0.26%-0.52%). Conclusion: Within the concentration range from 47.7 to 176.7 μg/m(3), short-term exposure to current level of PM(2.5) might increase both the all-cause daily mortality and daily emergency visits in China.

Comparative performance of the BGISEQ-500 and Illumina HiSeq4000 sequencing platforms for transcriptome analysis in plants

BACKGROUND

The next-generation sequencing (NGS) technology has greatly facilitated genomic and transcriptomic studies, contributing significantly in expanding the current knowledge on genome and transcriptome. However, the continually evolving variety of sequencing platforms, protocols and analytical pipelines has led the research community to focus on cross-platform evaluation and standardization. As a NGS pioneer in China, the Beijing Genomics Institute (BGI) has announced its own NGS platform designated as BGISEQ-500, since 2016. The capability of this platform in large-scale DNA sequencing and small RNA analysis has been already evaluated. However, the comparative performance of BGISEQ-500 platform in transcriptome analysis remains yet to be elucidated. The Illumina series, a leading sequencing platform in China's sequencing market, would be a preferable reference to evaluate new platforms.

METHODS

To this end, we describe a cross-platform comparative study between BGISEQ-500 and Illumina HiSeq4000 for analysis of Arabidopsis thaliana WT (Col 0) transcriptome. The key parameters in RNA sequencing and transcriptomic data processing were assessed in biological replicate experiments, using aforesaid platforms.

RESULTS

The results from the two platforms BGISEQ-500 and Illumina HiSeq4000 shared high concordance in both inter- (correlation, 0.88-0.93) and intra-platform (correlation, 0.95-0.98) comparison for gene quantification, identification of differentially expressed genes and alternative splicing events. However, the two platforms yielded highly variable interpretation results for single nucleotide polymorphism and insertion-deletion analysis.

CONCLUSION

The present case study provides a comprehensive reference dataset to validate the capability of BGISEQ-500 enabling it to be established as a competitive and reliable platform in plant transcriptome analysis.

Natural variation in the promoter of rice calcineurin B-like protein10 (OsCBL10) affects flooding tolerance during seed germination among rice subspecies

Rice (Oryza sativa L.) has two ecotypes, upland and lowland rice, that have been observed to show different tolerance levels under flooding stress. In this study, two rice cultivars, upland (Up221, flooding-intolerant) and lowland (Low88, flooding-tolerant), were initially used to study their molecular mechanisms in response to flooding germination. We observed that variations in the OsCBL10 promoter sequences in these two cultivars might contribute to this divergence in flooding tolerance. Further analysis using another eight rice cultivars revealed that the OsCBL10 promoter could be classified as either a flooding-tolerant type (T-type) or a flooding-intolerant type (I-type). The OsCBL10 T-type promoter only existed in japonica lowland cultivars, whereas the OsCBL10 I-type promoter existed in japonica upland, indica upland and indica lowland cultivars. Flooding-tolerant rice cultivars containing the OsCBL10 T-type promoter have shown lower Ca²⁺ flow and higher α-amylase activities in comparison to those in flooding-intolerant cultivars. Furthermore, the OsCBL10 overexpression lines were sensitive to both flooding and hypoxic treatments during rice germination with enhanced Ca²⁺ flow in comparison to wild-type. Subsequent findings also indicate that OsCBL10 may affect OsCIPK15 protein abundance and its downstream pathways. In summary, our results suggest that the adaptation to flooding stress during rice germination is associated with two different OsCBL10 promoters, which in turn affect OsCBL10 expression in different cultivars and negatively affect OsCIPK15 protein accumulation and its downstream cascade.

[Cases diagnosis of imported malaria in Jiangsu province, 2014-2016]

Objective: To understand the situation related to health seeking and diagnosis of imported malaria and to provide practical measures for malaria elimination in Jiangsu province. Methods: Data on imported malaria cases in Jiangsu province was retrieved in CISDCP from 2014 to 2016. Relevant information on health seeking behavior, diagnosis and treatment of the disease was gathered. Results: A total of 1 068 imported cases were reported in Jiangsu province from 2014 to 2016. Except for one malaria case that was caused by blood transfusion, the rest patients were all recognized as 'imported'. Majority of the cases were migrant laborers working in African countries. The accurate rates on the diagnosis of ovale, vivax and quartan malaria and mixed infection were relatively low, as 79.3% (107/135), 29.5% (18/61), 52.9% (18/34) and 0.0% (0/2) at the primary health care settings, respectively. Rate of seeking health care on the same day of onset was more in 2015 than in 2014 and 2016 (χ(2)=18.6, P=0.001). While only 65.4% (699/1 068) of the patients were diagnosed correctly at the primary health care settings. There appeared no statistical difference in the 3-year-study period (χ(2)=5.4, P=0.246). Capacity on 'correct diagnosis' seemed stronger at the CDC than at the hospital levels (χ(2)=13.2, P=0.000; χ(2)=5.4, P=0.020). Totally, 72.7% (32/44) of the severe falciparum malaria cases did not immediately seek for health care when the symptoms started. Conclusions: Migrant workers returning from the high endemic malaria areas seemed to have poor awareness in seeking health care services. Capability on correct diagnosis for malaria at the primary health care settings remained unsatisfactory and staff from these settings needs to receive adequate training.

[Research advances in hepatocyte-like cells from human induced pluripotent stem cells and their application]

Induced pluripotent stem cells (iPSCs) have the potential of proliferation and differentiation into a variety of somatic cells, including hepatocyte-like cells (HLCs). HLCs from human iPSCs (hiPSC-HLCs) have similar features and functions as primary hepatocytes and are used as an efficient in vitro model of hepatocytes, which brings hope to studies on liver diseases and drug hepatotoxicity evaluation. This article reviews the research advances in hiPSC-HLCs and their application in the fields of disease model, drug hepatotoxicity evaluation, and cell transplantation and discusses the future perspectives of the application of hiPSC-HLCs.

[Effect of goal-directed haemodynamic management on the postoperative outcome in elderly patients with fragile cardiac function undergoing abdominal surgery]

Objective: To investigate the effect of goal-directed haemodynamic management based on stroke volume variation (SVV), cardiac index (CI) and mean arterial blood pressure (MAP) on the postoperative outcome in elderly patients with fragile cardiac function undergoing gastrointestinal surgery. Methods: Ninety patients with fragile cardiac function, aged 65-90 years old, ASAⅡ or Ⅲ, NYHA Ⅱor Ⅲ, scheduled for abdominal surgery were enrolled in this study.The patients were randomly assigned to two groups: Experience anesthesia group (group E, n=45) and goal-directed hemodynamic management group (G group, n=45). After anesthesia induction, in group G, the SVV and CI were monitored by Vigileo and according SVV (≤12%), CI (≥2.5 L·min^-1·m^-2) and MAP (maintain the base value of ±20%) to adjust the preloaded infusion fluid and give positive inotropic drugs and positive pressure drugs; in group E, fluid and vasoactive agent were used according to the experience of anesthesiologist.Multi-mode monitoring anesthesia management using BIS, TCI of propofol, low-tidal-volume lung protective ventilation management strategy, body temperature protection, and postoperative multimodal analgesia techniques was performed in the two groups.Values of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT) were recorded before operation, at the end of operation, and postoperative 24 h. The incidence of myocardial infarction/angina, heart failure, arrhythmia and cerebral infarction, renal failure, length of hospitalization, and complications in 30-days after surgery were recorded by telephone follow-up. Results: Crystal, colloid, total liquid of group E were (1 110.20±332.00), (536.65±72.25), (1 677.20±424.44) ml and these of group G were (708.72±240.85), (414.41±74.31), (878.51±199.13) ml, respectively.Compared with group E, the fluid infusion were reduced in group G (t=6.057, 2.701, 9.742, all P<0.05). The lactic acid value of 24 hours after surgery in group G was significantly lower than that in group E [(0.89±0.31) mmol/L vs (1.11±0.43) mmol/L, t=-2.848, P<0.05]. Arterial partial pressure of oxygen at 24 hours after surgery in group G was higher than that in group E [(78.77±6.86) mmHg vs (76.46±10.96) mmHg, t=-1.108, P<0.05]. The length of hospitalization of group G was shorter than that of group E [(12.21±2.20) d vs (13.16±3.84) d, t=-1.341, P<0.05]. The incidence of total complication in hospital and in 30-days after surgery of group G were 10.26% and 5.13%, while these of group E were 29.73% and 24.32%, (χ²=4.545, 4.520, all P<0.05). ΔNT-proBNP₁ (the base value of NT-proBNP's minus the value of NT-proBNP's at the end of the operation) and ΔNT-proBNP₂ (the base value of NT-proBNP's minus the value of NT-proBNP's 24 hours postoperatively) of group G were 12.0(-291.0, 1 517.0) and 0(-6 770.0, 291.0), both higher than these of group E [0(-440.0, 200.0) and -12.0(-7 200, 22.0), (Z=-2.412, -2.163, all P<0.05)]. Conclusion: Goal-directed haemodynamic management based on SVV, CI and MAP could improve the outcome of the elderly patients with fragile heart function undergoing abdominal surgery.

Proteogenomic analysis reveals alternative splicing and translation as part of the abscisic acid response in Arabidopsis seedlings

In eukaryotes, mechanisms such as alternative splicing (AS) and alternative translation initiation (ATI) contribute to organismal protein diversity. Specifically, splicing factors play crucial roles in responses to environment and development cues; however, the underlying mechanisms are not well investigated in plants. Here, we report the parallel employment of short-read RNA sequencing, single molecule long-read sequencing and proteomic identification to unravel AS isoforms and previously unannotated proteins in response to abscisic acid (ABA) treatment. Combining the data from the two sequencing methods, approximately 83.4% of intron-containing genes were alternatively spliced. Two AS types, which are referred to as alternative first exon (AFE) and alternative last exon (ALE), were more abundant than intron retention (IR); however, by contrast to AS events detected under normal conditions, differentially expressed AS isoforms were more likely to be translated. ABA extensively affects the AS pattern, indicated by the increasing number of non-conventional splicing sites. This work also identified thousands of unannotated peptides and proteins by ATI based on mass spectrometry and a virtual peptide library deduced from both strands of coding regions within the Arabidopsis genome. The results enhance our understanding of AS and alternative translation mechanisms under normal conditions, and in response to ABA treatment.

A Phylogenetically Informed Comparison of GH1 Hydrolases between Arabidopsis and Rice Response to Stressors

Glycoside hydrolases Family 1 (GH1) comprises enzymes that can hydrolyze β-O-glycosidic bond from a carbohydrate moiety. The plant GH1 hydrolases participate in a number of developmental processes and stress responses, including cell wall modification, plant hormone activation or deactivation and herbivore resistance. A large number of members has been observed in this family, suggesting their potential redundant functions in various biological processes. In this study, we have used 304 sequences of plant GH1 hydrolases to study the evolution of this gene family in plant lineage. Gene duplication was found to be a common phenomenon in this gene family. Although many members of GH1 hydrolases showed a high degree of similarity in Arabidopsis and rice, they showed substantial tissue specificity and differential responses to various stress treatments. This differential regulation implies each enzyme may play a distinct role in plants. Furthermore, some of salt-responsive Arabidopsis GH1 hydrolases were selected to test their genetic involvement in salt responses. The knockout mutants of AtBGLU1 and AtBGLU19 were observed to be less-sensitive during NaCl treatment in comparison to the wild type seedlings, indicating their participation in salt stress response. In summary, Arabidopsis and rice GH1 glycoside hydrolases showed distinct features in their evolutionary path, transcriptional regulation and genetic functions.

SWATH-MS Quantitative Analysis of Proteins in the Rice Inferior and Superior Spikelets during Grain Filling

Modern rice cultivars have large panicle but their yield potential is often not fully achieved due to poor grain-filling of late-flowering inferior spikelets (IS). Our earlier work suggested a broad transcriptional reprogramming during grain filling and showed a difference in gene expression between IS and earlier-flowering superior spikelets (SS). However, the links between the abundances of transcripts and their corresponding proteins are unclear. In this study, a SWATH-MS (sequential window acquisition of all theoretical spectra-mass spectrometry) -based quantitative proteomic analysis has been applied to investigate SS and IS proteomes. A total of 304 proteins of widely differing functionality were observed to be differentially expressed between IS and SS. Detailed gene ontology analysis indicated that several biological processes including photosynthesis, protein metabolism, and energy metabolism are differentially regulated. Further correlation analysis revealed that abundances of most of the differentially expressed proteins are not correlated to the respective transcript levels, indicating that an extra layer of gene regulation which may exist during rice grain filling. Our findings raised an intriguing possibility that these candidate proteins may be crucial in determining the poor grain-filling of IS. Therefore, we hypothesize that the regulation of proteome changes not only occurs at the transcriptional, but also at the post-transcriptional level, during grain filling in rice.

Genetic diversity and population structure of Fenneropenaeus penicillatus determined by mitochondrial DNA analyses

Fenneropenaeus penicillatus is a widely distributed economically and ecologically important shrimp species, which is endangered in China. Sequence analysis of 16s rRNA and control region (CR) fragments from mitochondrial DNA was conducted to obtain information on genetic diversity and population structure. Individuals from 12 wild F. penicillatus populations located along the southeast coast of China were used. Polymerase chain reaction (PCR) fragments of the CR gene revealed high genetic diversity among the 12 populations; however, PCR fragments of the 16s rRNA gene revealed very low genetic diversity in the Hainan (HN) and Ningde (ND) populations and high genetic diversity in the DS, BH, PT, XM, and SZ populations. Data obtained from the CR and 16s rRNA genes suggested that high genetic differentiation exists among the 12 populations, which is mainly due to the high genetic differentiation between HN and all other 11 populations. These results may be useful for further sustainable management and utilization of this species.

Development and characterization of microsatellite loci in Megalonibea fusca

Megalonibea fusca is a commercially important large edible fish. In this study, the first set of 10 polymorphic microsatellite loci for M. fusca was developed and characterized. The number of alleles per locus ranged from two to five, with the observed and expected heterozygosities ranging from 0.0667 to 0.7667, and from 0.0644 to 0.5828, respectively. Most of the loci were in Hardy-Weinberg equilibrium (P > 0.05), except for two loci (Mf25 and Mf30) after a Bonferroni's correction (P < 0.005). These informative microsatellite markers will be useful in further studies of the population and conservation genetics of this species.

Development of novel and polymorphic microsatellite DNA loci from Haliotis ovina

Twelve microsatellite loci were developed from Haliotis ovina by the magnetic bead hybridization method. Genetic variability was assessed using 30 individuals from 3 wild populations. The number of alleles per locus ranged from 2 to 5, and the polymorphism information content ranged from 0.1228 to 0.6542. Observed and expected heterozygosities ranged from 0.0000 to 0.7778 and 0.1288 to 0.6310, respectively. These loci should provide useful information for genetic studies such as genetic diversity, pedigree analysis, construction of genetic linkage maps, and marker-assisted selection breeding in H. ovina.

Characterization of new microsatellite markers of Siganus fuscescens (Siganidae)

Siganus fuscescens, which is a small commercially important marine fish, is wildly distributed in shallow waters throughout the tropical and subtropical Indo-Pacific and Eastern Mediterranean regions. It is part of a group known as rabbitfish. Fifteen new polymorphic microsatellite markers for S. fuscescens were identified, and 32 wild individuals were used to evaluate the degree of polymorphism of these markers. The number of alleles per locus ranged from 2 to 12, and the polymorphism information content ranged from 0.210 to 0.849. The observed and expected heterozygosities were 0.142-0.808 and 0.225-0.853, respectively. Although significant deviations from Hardy-Weinberg equilibrium were detected at 2 loci (Sf1-37-2 and Sf1-47), no significant deviations were detected at the other 13 loci. These microsatellite markers will provide a useful tool for studies on genetic diversity and differentiation of S. fuscescens.

Physical mechanism of surface roughening of the radial Ge-core/Si-shell nanowire heterostructure and thermodynamic prediction of surface stability of the InAs-core/GaAs-shell nanowire structure

As a promising and typical semiconductor heterostructure at the nanoscale, the radial Ge/Si NW heterostructure, that is, the Ge-core/Si-shell NW structure, has been widely investigated and used in various nanodevices such as solar cells, lasers, and sensors because of the strong changes in the band structure and increased charge carrier mobility. Therefore, to attain high quality radial semiconductor NW heterostructures, controllable and stable epitaxial growth of core-shell NW structures has become a major challenge for both experimental and theoretical evaluation. Surface roughening is usually undesirable for the epitaxial growth of high quality radial semiconductor NW heterostructures, because it would destroy the core-shell NW structures. For example, the surface of the Ge-core/Si-shell NWs always exhibits a periodic modulation with island-like morphologies, that is, surface roughening, during epitaxial growth. Therefore, the physical understanding of the surface roughening behavior during the epitaxial growth of core-shell NW structures is essential and urgent for theoretical design and experimentally controlling the growth of high quality radial semiconductor NW heterostructures. Here, we proposed a quantitative thermodynamic theory to address the physical process of epitaxial growth of core-shell NW structures and surface roughening. We showed that the transformation from the Frank-van der Merwe mode to the Stranski-Krastanow mode during the epitaxial growth of radial semiconductor NW heterostructures is the physical origin of surface roughening. We deduced the thermodynamic criterion for the formation of the surface roughening and the phase diagram of growth and showed that the radius of the NWs and the thickness of the shell layer can not only determine the formation of the surface roughening in a core-shell NW structure, but also control the periodicity and amplitude of the surface roughness. The agreement between the theoretical results and the experimental data of the Ge-core/Si-shell NW structure implied that the established approach could be applicable to the understanding and design of various semiconductor core-shell NW structures. Consequentially, we used the established theoretical model to study the epitaxial growth of the InAs-core/GaAs-shell NW structure and predict the surface roughening formation, as well as the periodicity and amplitude of the surface roughness, which provided useful information to theoretically design and experimentally control the epitaxial growth of the radial InAs-core/GaAs-shell NW structure.

Characterization of eight novel microsatellite markers in the green-lipped mussel Perna viridis (Mytilidae)

The green lipped mussel, also known as the Asian green mussel (Perna viridis) is a fast reproducing and valuable food source, but it is also considered an invasive species and can clog and damage pipes and marine equipment. Eight novel polymorphic microsatellite loci for P. viridis were isolated and characterized. Microsatellite polymorphism was evaluated in 30 individuals collected from Xiamen, China. The number of alleles per locus and the polymorphism information content ranged from 2 to 5 and from 0.3092 to 0.7031, respectively. The observed and expected heterozygosities were 0.1538-0.8400 and 0.1448-0.6833, respectively. The loci identified in this study could provide a useful tool for the genetic population structure analysis of P. viridis.

Isolation and characterization of new microsatellite markers in the pen shell Atrina pectinata (Pinnidae)

The pen shell, Atrina pectinata, is a commercially important bivalve species, widely consumed in the Asian Pacific region. We identified 16 new microsatellite makers for A. pectinata using a modified fast isolation by AFLP of sequences containing repeat protocols; 27 individuals were collected from Xiamen to evaluate the degree of polymorphism. The number of polymorphic alleles per locus ranged from 2 to 11. The observed and expected heterozygosities were 0.050-0.913 and 0.049-0.869, respectively. The loci identified in this study could provide a useful tool for research on genetic diversity and genetic differentiation of A. pectinata populations.

PTEN polymorphisms and the risk of esophageal carcinoma and gastric cardiac carcinoma in a high incidence region of China

PTEN, as a tumor suppressor gene, plays an important role in regulating cell growth, proliferation, and apoptosis. Two common polymorphisms, -9C/G and IVS4 (-/+), may alter susceptibility to the disease. To test the hypothesis that the genetic variations of PTEN play a role in the etiology of esophageal squamous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA), a population-based case-control study was conducted in 350 ESCC patients, 257 GCA patients, and 634 healthy controls from a high-incidence region of Hebei province, China. The PTEN polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP). The results showed that the family history of upper gastrointestinal cancer (UGIC) significantly increased the risk of developing ESCC and GCA (the age, gender and smoking status adjusted OR = 1.73 and 1.67; 95% CI = 1.29-2.32 and 1.28-2.19, respectively). The overall distribution of the PTEN -9C/G genotype was not significantly different between cancer patients and controls. Compared with the PTEN IVS4-/- genotype, the IVS4+/+ genotype significantly decreased the risk of ESCC and GCA development, the adjusted OR was 0.64 (95% CI = 0.44-0.94) and 0.63 (95% CI = 0.41-0.98), respectively. Stratification analysis by gender, age, smoking status and family history of UGIC showed that the PTEN IVS4-/+ genotype only reduced the risk of ESCC (adjusted OR = 0.55, 95%CI = 0.34-0.90) among subjects with family history of UGIC. While the IVS4+/+ genotype decreased the susceptibility to both ESCC and GCA (adjusted OR = 0.61 and 0.57, 95% CI = 0.37-0.98 and 0.34-0.98, respectively) among male subjects, the IVS4+/+ genotype only decreased the risk of ESCC development among subjects younger than 55 years (adjusted OR = 0.43, 95% CI = 0.21-0.85). In addition, the haplotype analysis found that the -9C/IVS4- haplotype increased the risk of developing ESCC and GCA (OR = 1.31 and 1.24, 95% CI = 1.08-1.58 and 1.001-1.53). Our results suggested that the PTEN IVS4+/+ homozygote may play a protective role in the development of ESCC and GCA, while the haplotype -9C/IVS4- might be the risk factor of the development of ESCC and GCA in the high incidence region population of Hebei province, China.

The genomic sequence and biological properties of Pennisetum mosaic virus, a novel monocot-infecting potyvirus

The complete nucleotide sequences of two isolates of Pennisetum mosaic virus (PenMV) were determined. The viral genome comprised 9,611 nucleotides (nt) excluding the 3'-terminal poly(A) sequence, with the capacity of encoding a single polyprotein of 3,065 amino acids. The large open reading frame is flanked by a 172-nt 5'-untranslated region (UTR) and a 244-nt 3'-UTR. Sequence comparisons and phylogenetic analyses of the complete genome and polyproteins suggest that PenMV is closely related to other monocot potyviruses such as Maize dwarf mosaic virus, Sorghum mosaic virus and Sugarcane mosaic virus (SCMV), and thus represents a distinct potyvirus within the SCMV subgroup. The host range of PenMV is limited to Gramineae, and the virus naturally infects maize, sorghum and some wild grasses, causing mosaic symptoms on the leaves. This virus could be transmitted by both mechanical inoculation and by at least four species of aphids.

Candida albicans THI13 disruption affects production of monocytic cytokines

INTRODUCTION

The Candida albicansTHI13 gene was identified by its homology to the Candida tropicalis CtNMT1 gene, which is involved in pyrimidine precursor biosynthesis.

METHODS

Disruption of THI13 revealed that this gene played a minor role in thiamin biosynthesis in C. albicans. Purified human monocytes were incubated with C. albicans at the optimal Candida: monocyte ratio of 0.5 and cytokines in the supernatants were measured by enzyme-linked immunosorbent assay.

RESULTS AND DISCUSSION

This experiment showed that the wild-type strain significantly induced interleukin-10 (IL-10) production but had little effect on IL-12 production, and that THI13 mutants had no significant effect on IL-10 production, though the IL-12 level was increased in the supernatants. These results suggest that THI13 is involved in the host effective immune response by regulating IL-10 and IL-12 production.

[Isolation and identification of two new secoiridoids of water-soluble chemical constituents from the fruits of Ligustrum lucidum Ait]

Two new secoiridoids named as specnuezhenide (I) and nuezhengalaside (II) were isolated from the water-soluble part of dry fruits of Ligustrum lucidum Ait. Their structures were established on the basis of chemical analysis and spectral data (UV, IR, 1H-NMR, NOEDS, HOMO-DEC, 13C-NMR, DEPT and MS).

Overall and internal dynamics of DNA as monitored by five-atom-tethered spin labels

Electron paramagnetic resonance (EPR) spectra of the two-atom-tethered six-membered ring thymidylate spin label (DUMTA) incorporated into duplexes of different sizes were found to display a helix length dependence and a local-order parameter S = 0.32 +/- 0.01 for B-DNA based on the dynamic cylinder model (Keyes, R. S., and A. M. Bobst. 1995. Detection of internal and overall dynamics of a two-atom-tethered spin-labeled DNA. Biochemistry. 34:9265-9276). This sensitivity to size, which reflects global tumbling, is now reported for the more flexible five-atom-tethered five-membered ring thymidylate spin label (DUAP) that can be readily incorporated enzymatically and sequence specifically into nucleic acids of different sizes. The DUAPs containing B-DNA systems were simulated with the same dynamic cylinder model, giving S = 0.20 +/- 0.01 for the more flexibly tethered spin label. This shows that S is dependent on tether length but not on global motion. An analysis with the same motional model of the B-Z transition in a (dG-dC)n polymer containing the five-atom-tethered six-membered ring cytidylate spin label (DCAT) (Strobel, O. K., R. S. Keyes, and A. M. Bobst. 1990b. Base dynamics of local Z-DNA conformations as detected by electron paramagnetic resonance with spin-labeled deoxycytidine analogues. Biochemistry. 29:8522-8528) revealed an increase in S from 0.15 +/- 0.01 to 0.26 +/- 0.01 in response to the B- to Z-DNA transition. This indicates that S is not only sensitive to tether length, but also to conformational changes in DNA. Both the DUAP- and the DCAT-labeled systems were also simulated with a base disk model. From the DUAP spectral series, the perpendicular component of the correlation time tau perpendicular describing the spin-labeled base diffusion was found to be sensitive to global tumbling, confirming earlier results obtained with DUMTA. The DCAT polymer results demonstrated that tau perpendicular monitors a conformational change from B- to Z-DNA, indicating that tau perpendicular is also sensitive to local base dynamics. These results confirm that the dynamics of five-atom-tethered nitroxides are coupled to the nucleic acid dynamics and, as with two-atom-tethered spin labels, can be characterized by S and tau perpendicular. The analyses of both spin-labeled systems provide good evidence for spin-labeled base motions within double-stranded DNA occurring on the nanosecond time scale, and establish that both labels can be used to monitor changes in global tumbling and local order parameter due to variations in DNA conformation and protein-DNA interactions.

Spin-labeled nucleotide mobility in the boundary of the EcoRI endonuclease binding site

A complex consisting of the EcoRI endonuclease site-specifically bound to spin-labeled DNA 26mers was prepared to provide a model system for studying possible conformational changes resulting from protein binding. EPR was used to monitor the mobility of the spin labels that were strategically placed in position 6, 9, or 11 with respect to the dyad axis of the 26mer. These positions are located within the flanking region on either side of the EcoRI hexamer binding site. This allows the monitoring of potential distal structural changes in the DNA helix caused by protein binding. The spectral line shapes indicate that the spin label closest to the EcoRI endonuclease binding site, i.e., in position 6, is most influenced by the binding event. The EPR data are analyzed according to a model that distinguishes between spectral effects due to a change in the hydrodynamic shape of the complex and those resulting from local variations in the spin-label mobility as characterized by a local order parameter S. S reflecting the motional restriction of the spin-labeled base is 0.20 +/- 0.01 for all three oligomers as well as for the two complexes with the label in position 9 or 11, while the position 6 labeled complex yields S = 0.25. To further evaluate the origin of the slightly larger EPR effect observed with position 6 labeled material, molecular dynamics (MD) simulations were used to explore the space accessible to the probes in positions 6, 9, and 11. MD results gave similar nitroxide trajectories for all three labeled 26mers in the absence or presence of EcoRI. Thus, the small position 6 effect is attributed to a structural distortion in the major groove of the DNA at this location possibly corresponding to a bend induced by protein binding. The observation that the spectral changes are small indicates the absence of any significant structural disruption being propagated along the helix as a result of protein binding. Also, the fact that the line shape of the 26mers did not change as expected from hydrodynamic theory in view of the significant increase in molecular volume upon protein binding suggests that there are additional relaxation processes involving the protein and nucleic acid.

Spectroscopic probe for the detection of local DNA bending at an AAA triplet

Spectroscopic evidence of a DNA bend in solution is presented by analyzing model 15-mer duplexes spin-labeled with the five-atom-tethered nitroxide DUAP located in the major groove. Three 15-mers containing AATT with DUAP enzymatically incorporated into three different positions yielded nearly identical line shapes while a fourth 15-mer containing AAATT produced an EPR spectrum with significant additional line broadening. These results are interpreted according to the dynamic cylinder model where the DNA dynamics are decoupled into overall and internal contributions. It is shown that the AAATT sequence induces a change in the internal dynamics characterized by local ordering of DUAP. The increase in ordering evident in 15-mers containing AAATT rather than AATT suggests that the former sequence gives rise to a bend toward the major groove resulting in spatial restriction of the probe.

[Dynamic studies of NK activity, IL-2 production and sIL-2R expression in primary hepatic carcinoma patients before and after operation]

The results of a dynamic study of NK activity, IL-2 production and sIL-2R expression before and after operation in 30 primary hepatic carcinoma patients are reported. The NK activity and IL-2 production of patients were significantly lower, sIL-2R expression was remarkably enhanced than those of controls. There was a period of immune suppression after operation. NK activity and IL-2 production of patients with recurrence were significantly lower and sIL-2R expression was significantly enhanced than than those of patients without recurrence. The period of immune suppression in patients with recurrence was longer than that of patients without recurrence. The results suggest that the changes of NK activity, IL-2 production and sIL-2R expression are closely related to the prognosis of patients with primary hepatic carcinoma.

Studies in monkeys of attenuated hepatitis A variants

Three HAV variants, H2M20(35 degrees C), H2M20(35 degrees C) and H2M20K5(32 degrees C), were developed by passage in different tissue culture cells and at different temperatures. Virulence for monkeys was assessed by inoculating each of the variants into four monkeys. Weekly bleeding through 16 weeks post-inoculation was assayed for anti-HAV titers and SGPT as well as LDH5 activities. And in some monkeys liver biopsies were also studied. Seroconversion was induced in all of the inoculated monkeys. The anti-HAV titers tested at 16 weeks post-inoculation were: 40-640 with H2M20(35 degrees C), 40-160 with H2M20(32 degrees C) and 20-40 with H2M20K5(32 degrees C). These variants showed different levels of virulence/attenuation for monkeys. Variant H2M20(35 degrees C) showed no evidence of attenuation, variant H2M20(32 degrees C) retained slight virulence and variant H2M20K5(32 degrees C) showed no evidence of virulence for monkeys. Criteria are proposed for assay of HAV virulence tested in monkeys.