[Establishment of a fluorescent recombinase-aided isothermal amplification assay for nucleic acid detection of Paraginiumus skrjabini and preliminary evaluation of its detection efficiency]

OBJECTIVE

To establish a nucleic acid assay for detection of Paragonimus skrjabini based on the recombinase-aided isothermal amplification (RAA) technique, and to preliminarily evaluate its detection efficiency.

METHODS

The metacercariae of P. skrjabini, P. westermani and Euparagonimus cenocopiosus were isolated from crabs, and genomic DNA was extracted for molecular characterization. The cytochrome coxidase 1 (cox1) gene sequence of P. skrjabini was selected as the target gene fragment, and the primers and probes were designed, screened and synthesized for RAA assay. The genomic DNA of P. skrjabini metacercariae from Jiyuan City and Yiyang County of Luoyang City, Henan Province were used as templates for verification of the fluorescent RAA assay. The fluorescent RAA assay was performed to detect different concentrations of plasmids containing target gene fragment and P. skrjabini metacercariae genomic DNA to determine the sensitivity. Fluorescent RAA assay was performed with recombinant plasmids containing P. skrjabini cox1 gene sequences at different concentrations and P. skrjabini genomic DNA as templates to evaluate its sensitivity, and the genomic DNA of P. westermani, E. cenocopiosus, Clonorchis sinensis and Schistosoma japonicum was detected with fluorescent RAA assay to evaluate its specificity.

RESULTS

P. skrjabini, P. westermani and E. cenocopiosus metacercariae were isolated from crabs, respectively. Molecular characterization and phylogenetic analysis confirmed their homology with the genes sequences of standard Paragonimus strains in GenBank. A fluorescent RAA assay was successfully established for nucleic acid detection of P. skrjabini, and the genomic DNA of P. skrjabini metacercariae from Jiyuan City and Yiyang County of Luoyang City, Henan Province was amplified using the fluorescent RAA assay within 5 min, while the negative control was not amplified. If the recombinant plasmid containing P. skrjabini cox1 gene sequences was used as templates, the fluorescent RAA assay showed the lowest detection limit of 10 copies/μL, and positive amplification was observed within 5 min. If genomic DNA was used as templates, the fluorescent RAA assay showed the lowest detection limit of 10 pg/μL, and all positive amplifications were found within 5 to 10 min. In addition, the fluorescent RAA assay was tested negative for P. westermani, E. cenocopiosus, C. sinensis and S. japonicum.

CONCLUSIONS

A rapid, sensitive and specific fluorescent RAA assay is successfully established for nucleic acid detection of P. skrjabini, which has potential values in rapid field detection and species identification in freshwater crabs in areas endemic for P. skrjabini.

Understanding charge storage in Nb2CTx MXene as an anode material for lithium ion batteries

MXenes represent an emerging family of two-dimensional materials of transition metal carbides/carbonitrides terminated with functional groups like -O, -OH, and -F on the chemically active surface of MX slabs. As a member of the family, Nb₂CT_x exhibits superior lithium storage capacity over most of the other MXenes as anode materials in lithium-ion batteries (LIBs). However, an in-depth understanding of the charge storage mechanism is still lacking so far. Here, through combining complementary experiments and density functional theory calculations, we provide insights into the (de)lithiation process. Specifically, Nb₂CT_x with dominant -O functional groups stores charge as a result of changes in the oxidation states of both transition metals Nb and O, which is supported by Bader charge analysis showing a significant change in the oxidation states of Nb and O upon lithiation. As monitored by ex situ X-ray diffraction, the interlayer spacing of Nb₂CT_x changes slightly upon lithium ion (de)intercalation, corresponding to a volume change of only 2.3% with a near zero-strain feature. By coupling with a LiFePO₄/C cathode, the full cell presents superior rate capability and cycling stability as well. The insights into the charge storage mechanism of Nb₂CT_x in this work provide useful guidance for the rational design of MXene-based anode materials for high-performance LIBs.

[Risk stratified management of cervical adenocarcinoma in situ based on cone margin state]

Objective: To investigate the hierarchical management scheme of cervical adenocarcinoma in situ (AIS) based on cervical conization margin state. Methods: All medical records of 249 patients diagnosed as AIS by loop electrosurgical excision procedure (LEEP) conization from Jan. 2010 to Dec. 2015 in Obstetrics and Gynecology Hospital of Fudan University were retrospectively reviewed, to explore the relationship between the status of the resection margin and the residual lesion after LEEP, and the multivariate logistic regression method was used to analyze the related factors that affect the residual lesion after LEEP in cervical AIS patients. Results: (1) The age of 249 cervical AIS patients was (40±8) years old (range: 23-71 years old). Of the 249 patients, 19 (7.6%, 19/249) had residual lesions; 69 cases were pathologically diagnosed as AIS after LEEP, and the residual lesion rate was 13.0% (9/69), which was significantly higher than that of AIS + high-grade squamous intraepithelial lesion [5.6% (10/180); χ²=3.968,P=0.046]; 33 cases were multifocal lesions, the residual rate of lesions was 21.2% (7/33), which was significantly higher than that of single focal lesions patients [5.6% (12/216); χ²=7.858, P=0.005]; 181 patients underwent endocervical curettage (ECC) before surgery, the residual rate of lesions in ECC-positive patients was 14.0% (14/100) , significantly higher than that of ECC-negative patients [4.9% (4/81); χ²=4.103, P=0.043]. (2) Among 249 cases of AIS patients, the positive rate of resection margins after LEEP was 35.3% (88/249); the residual rate of lesions in patients with positive resection margins (14.8%, 13/88) was significantly higher than those with negative margins [3.8%(6/156); χ²=9.355, P=0.002]. The age of patients underwent total hysterectomy after LEEP was (43±7) years old, which was significantly higher than that of patients who did not undergo total hysterectomy [(37±8) years old; t=6.518, P<0.01].Among the patients underwent total hysterectomy after LEEP, 3 cases (2.0%, 3/152) had fertility requirements, while 38 cases (39.2%, 38/97) did not underwent total hysterectomy, the difference between the two groups was statistically significant (χ²=59.579, P<0.01). Among the 152 patients who underwent total hysterectomy after LEEP, the residual rate of lesions was 11.8% (18/152); the residual rate of lesions in patients with positive resection margins was significantly higher than that of patients with negative resection margins [18.8% (12/64) vs 7.0% (6/86); χ²=4.861, P=0.028]. The median follow-up time of 97 patients who did not undergo total hysterectomy after LEEP was 32 months (range: 4-70 months). During the follow-up period, 3 cases of cervical AIS recurrence (3.1%, 3/97) and were followed by hysterectomy,no invasive adenocarcinoma were seen. (3) Multivariate logistic regression analysis showed that the positive resection margin (OR=4.098, 95%CI: 1.235-13.595, P=0.021), multifocal lesions (OR=5.464, 95%CI: 1.494-19.981, P=0.010) were independent risk factors that affected the residual lesions in patients with cervical AIS after LEEP. Conclusions: The cervical AIS patients after LEEP conization suggested be stratified by cone margin state as the first-line stratified index, age and fertility needs as the second-line stratified management index. The individualized management plan should be developed based on comprehensive assessment of high-risk factors of residual lesions.

[Susceptibility of Anopheles sinensis to insecticides in Puyang City, Henan Province]

OBJECTIVE

To investigate the susceptibility of Anopheles sinensis to malathion, deltamethrin and lambda-cyhalothrin in Puyang City, Henan Province, so as to provide the scientific basis for local malaria vector control.

METHODS

An. sinensis was captured from Puyang County, Puyang City of Henan Province in September 2018 and July 2020, and the susceptibility of field captured An. sinensis to malathion, deltamethrin and lambda-cyhalothrin was tested using the filter-paper bioassay recommended by WHO. The insecticide resistance level was assessed based on the WHO criteria.

RESULTS

In 2018 and 2010, the half knock-down times (KT₅₀) of malathion were 91.08 min and 40.95 min for An. sinensis, with knock-down rates of 37.50% and 60.87% 60 min post-exposure to malathion and 24-hour mortality rates of 90.91% and 100%, respectively, and the insecticide resistance levels were moderately resistant (M) and susceptible (S). The KT₅₀ of deltamethrin were 415.56 min and 341.19 min for An. sinensis in 2018 and 2020, with knock-down rates of 22.92% and 16.98% 60 min post-exposure to malathion and 24-hour mortality rates of 22.92% and 16.98%, and the insecticide resistance levels were all resistant (R). The KT₅₀ of lambda-cyhalothrin were 164.22 min and 236.22 min for An. sinensis in 2018 and 2020, with knock-down rates of 30.39% and 38.30% 60 min postexposure to malathion and 24 h mortality rates of 19.60% and 21.28%, respectively, and the insecticide resistance levels were all R.

CONCLUSIONS

An. sinensis is relatively susceptible to malathion but has developed high-level resistance to deltamethrin and lambda-cyhalothrin in Puyang City, Henan Province..

[Prevalence of intestinal protozoan infections among rural children in Henan Province from 2014 to 2015]

OBJECTIVE

To investigate the prevalence and influencing factors of intestinal protozoan infections among rural children in Henan Province.

METHODS

A total of 104 survey sites were sampled from 35 counties (cities) in Henan Province using the stratified cluster sampling method to investigate the prevalence of intestinal protozoan infections among rural children from 2014 to 2015. The trophozoites and cysts of intestinal protozoa were identified using the iodine staining method and the physiological saline direct smear method (one detection for one stool sample). The prevalence of intestinal protozoan infections was compared among rural children with different characteristics, and the factors affecting intestinal protozoan infections among rural children were identified.

RESULTS

The overall prevalence of intestinal protozoan infections was 0.60% (40/6 771) among rural children in Henan Province from 2014 to 2015. There were 7 species of intestinal protozoa identified, and there was no species-specific prevalence (χ² = 37.732, P = 0.000). No significant differences were found in prevalence of intestinal protozoan infections among rural children in terms of gender (χ² = 1.793, P = 0.181), age (χ² = 1.443, P = 0.486), occupation (χ² = 0.219, P = 0.896) or ecological region (χ² = 1.700, P = 0.637). In addition, terrain (χ² = 2.311, P = 0.510), economic level (χ² = 4.322, P = 0.229), source of drinking water (χ² = 0.731, P = 0.393), eating raw vegetables (χ² = 1.134, P = 0.287) and deworming (χ² = 1.089, P = 0.297) had no remarkable effects on the prevalence of intestinal protozoan infections among rural children in Henan Province; however, the prevalence of intestinal protozoan infections varied significantly among rural children living in regions with different coverage of non-harmless toilets (χ² = 10.050, P = 0.018).

CONCLUSIONS

The prevalence of intestinal protozoan infections is low among rural children in Henan Province.

Fabrication of Low Roughness Gradient Nanostructured Inner Surface on an AISI 304 Stainless Steel Pipe via Ultra-Sonic Rolling Treatment (USRT)

Gradient nanostructure (GNS) has drawn great attention, owing to the unique deformation and properties that are superior to nanostructure with uniform scale. GNS is commonly fabricated via surface plastic deformation with small tips (of balls or shots) so as to produce high deformation to refine the coarse grains, but unfortunately it suffers from the deterioration of surface quality which is hard to guarantee the reliable service. Although there are mirror-finishing techniques that can greatly enhance the surface quality, the induced slight deformation is commonly unable to produce GNS of reasonable thickness. Here, we propose a method to fabricate a GNS surface layer with a substantially enhanced surface quality via ultra-sonic rolling treatment (USRT), namely, surface rolling with a roller vibrated at a frequency of 20,000 Hz. It is found that 4-pass USRT is able to produce 20–30 µm thick GNS on AISI 304 stainless steel pipe inner surface, wherein the surface quality is enhanced by one order of magnitude from the starting Ra = 3.92 µm to 0.19 µm. Processing by a roller with a high-frequency vibration is necessary for both good surface quality and the effective accumulation of heavy deformation on the surface. The flattening mechanism as well as the microstructural evolution from millimeter- to nanometer-scale for AISI 304 stainless steel is discussed.

[Clinical and genetic studies on 76 patients with hydrocephalus caused by methylmalonic acidemia combined with homocysteinuria]

Objective: To analyze the clinical features, genetic characteristics, treatment and follow-up results of patients with hydrocephalus caused by methylmalonic acidemia combined with homocysteinuria, and to discuss the optimal strategies for assessing and treating such patients. Methods: From January 1998 to December 2020, 76 patients with hydrocephalus due to methylmalonic acidemia combined with homocysteinuria in the Department of Pediatrics in 11 hospitals including Peking University First Hospital were diagnosed by biochemical, genetic analysis and brain imaging examination. The patients were divided into operation-group and non-operation-group according to whether they underwent ventriculoperitoneal shunt. The clinical features, laboratory examinations, genotype, and follow-up data were retrospectively analyzed. Data were compared between the two groups using rank sum test, and categorical data were compared using χ² test. Results: Among the 76 patients (51 male, 25 female), 5 were detected by newborn screening, while 71 were diagnosed after clinical onset, 68 cases (96%) had early-onset, 3 cases (4%) had late-onset. The most common clinical manifestations of 74 cases with complete data were psychomotor retardation in 74 cases (100%), visual impairment in 74 cases (100%), epilepsy in 44 cases (59%), anemia in 31 cases (42%), hypotonia or hypertonia in 21 cases (28%), feeding difficulties in 19 cases (26%) and disturbance of consciousness in 17 cases (23%). Genetic analysis was performed in 76 cases, all of whom had MMACHC gene variations, including 30 homozygous variations of MMACHC c.609G>A. The most common variations were c.609G>A (94, 62.7%), followed by c.658_660del (18, 12.0%), c.567dupT (9, 6.0%) and c.217C>T (8, 5.3%). Therapy including cobalamin intramuscular injection, L-carnitine and betaine were initiated immediately after diagnosis. A ventriculoperitoneal shunt operation was performed in 41 cases (operation group), and 31 patients improved after metabolic intervention (non-operation group). There was no significant difference in the age of onset, the age of diagnosis, the blood total homocysteine, methionine, and urinary methylmalonic acid concentration between the two groups (all P>0.05). The symptoms of psychomotor development, epilepsy, and visual impairments improved gradually after a long-term follow-up in the operation group. Conclusions: Hydrocephalus is a severe complication of methylmalonic acidemia combined with homocysteinuria. The most common clinical manifestations are psychomotor retardation, visual impairment, and epilepsy. It usually occurs in early-onset patients. Early diagnosis and etiological treatment are very important. Hydrocephalus may improve after metabolic intervention in some patients. For patients with severe ventricular dilatation, prompt surgical intervention can improve the prognosis.

[A multi-center retrospective study of perioperative chemotherapy for gastric cancer based on real-world data]

Objective: To explore the effect of perioperative chemotherapy on the prognosis of gastric cancer patients under real-world condition. Methods: A retrospective cohort study was carried out. Real world data of gastric cancer patients receiving perioperative chemotherapy and surgery + adjuvant chemotherapy in 33 domestic hospitals from January 1, 2014 to January 31, 2016 were collected. Inclusion criteria: (1) gastric adenocarcinoma was confirmed by histopathology, and clinical stage was cT2-4aN0-3M0 (AJCC 8th edition); (2) D2 radical gastric cancer surgery was performed; (3) at least one cycle of neoadjuvant chemotherapy (NAC) was completed; (4) at least 4 cycles of adjuvant chemotherapy (AC) [SOX (S-1+oxaliplatin) or CapeOX (capecitabine + oxaliplatin)] were completed. Exclusion criteria: (1) complicated with other malignant tumors; (2) radiotherapy received; (3) patients with incomplete data. The enrolled patients who received neoadjuvant chemotherapy and adjuvant chemotherapy were included in the perioperative chemotherapy group, and those who received only postoperative adjuvant chemotherapy were included in the surgery + adjuvant chemotherapy group. Propensity score matching (PSM) method was used to control selection bias. The primary outcome were overall survival (OS) and progression-free survival (PFS) after PSM. OS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the last effective follow-up or death. PFS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the first imaging diagnosis of tumor progression or death. The Kaplan-Meier method was used to estimate the survival rate, and the Cox proportional hazards model was used to evaluate the independent effect of perioperative chemo therapy on OS and PFS. Results: 2 045 cases were included, including 1 293 cases in the surgery+adjuvant chemotherapy group and 752 cases in the perioperative chemotherapy group. After PSM, 492 pairs were included in the analysis. There were no statistically significant differences in gender, age, body mass index, tumor stage before treatment, and tumor location between the two groups (all P>0.05). Compared with the surgery + adjuvant chemotherapy group, patients in the perioperative chemotherapy group had higher proportion of total gastrectomy (χ(2)=40.526, P<0.001), smaller maximum tumor diameter (t=3.969, P<0.001), less number of metastatic lymph nodes (t=1.343, P<0.001), lower ratio of vessel invasion (χ(2)=11.897, P=0.001) and nerve invasion (χ(2)=12.338, P<0.001). In the perioperative chemotherapy group and surgery + adjuvant chemotherapy group, 24 cases (4.9%) and 17 cases (3.4%) developed postoperative complications, respectively, and no significant difference was found between two groups (χ(2)=0.815, P=0.367). The median OS of the perioperative chemotherapy group was longer than that of the surgery + adjuvant chemotherapy group (65 months vs. 45 months, HR: 0.74, 95% CI: 0.62-0.89, P=0.001); the median PFS of the perioperative chemotherapy group was also longer than that of the surgery+adjuvant chemotherapy group (56 months vs. 36 months, HR=0.72, 95% CI:0.61-0.85, P<0.001). The forest plot results of subgroup analysis showed that both men and women could benefit from perioperative chemotherapy (all P<0.05); patients over 45 years of age (P<0.05) and with normal body mass (P<0.01) could benefit significantly; patients with cTNM stage II and III presented a trend of benefit or could benefit significantly (P<0.05); patients with signet ring cell carcinoma benefited little (P>0.05); tumors in the gastric body and gastric antrum benefited more significantly (P<0.05). Conclusion: Perioperative chemotherapy can improve the prognosis of gastric cancer patients.

[Clinical features and gene mutations of 6 patients with carnitine palmitoyltransferase 1A deficiency]

The clinical and biochemical data and gene sequencing results of patients with carnitine palmitoyltransferase 1A deficiency were analyzed, in order to improve the understanding of the disease. Six patients (5 males and 1 female, aged from 1 to 8 years old) with carnitine palmitoyltransferase 1A deficiency from Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital between 2008 and 2019 were included. Two cases were detected by neonatal screening and had no clinical symptoms. The remaining 4 cases all showed seizures induced by fever, vomiting or diarrhea. All the 6 patients showed increased serum free carnitine (C0), decreased hexadecanoylcarnitine (C16) and octadecanoylcarnitine (C18), and increased C0/(C16+C18). Meanwhile, compound heterozygous mutations of CPT1A gene were detected in all 6 patients, of which 2 were reported mutations (c.281+1G>A and c.968-8C>T), and 10 were new mutations. The new mutations included 6 missense mutations, 1 nonsense mutation, 1 deletion mutation and 2 splicing mutations. Detection of free carnitine and acyl carnitine by tandem mass spectrometry is helpful for early screening and diagnosis of carnitine palmitoyltransferase 1A deficiency.

[Advances in the research of comorbidity of Blastocystis hominis infections and other diseases]

Blastocystis hominis is a common intestinal protozoan parasite. Most individuals with B. hominis infections have no apparent clinical symptoms; however, a few patients, notably those with co-infections or impaired immune system function may present abdominal pain, diarrhea, nausea, vomiting, and even death. This paper reviews the co-infections of B. hominis and other pathogens and comorbidity of B. hominis infections and other diseases, so as to provide insights into the management of B. hominis infections.

Delayed seroreversion of specifical antibody against HIV in HIV-exposed infants: A retrospective cohort study

OBJECTIVES

To investigate the seroreversion time in HIV-1-exposed but uninfected infants from two tertiary hospitals in China.

METHODS

This study retrospectively investigated the data of perinatal, HIV-1-exposed infants from hospitals in Beijing and Shenzhen. Maternal and infant medical records from both hospitals from January 2009 to December 2019 were reviewed, and the HIV antibody seroreversion times of infants were determined. From 2009 to 2019, a total of 485 HIV-1-exposed but uninfected infants were enrolled. The majority of infants were born at term with normal birth weight.

RESULTS

The seroreversion rates were 89.3%, 94.2% and 100% at 12, 18 and 24 months of age, respectively. There were no significant associations between seroreversion and several risk factors, such as gender, birth weight, gestational age, mode of delivery, postpartum prophylaxis and antiretroviral treatment duration. The mean value of HIV-specific immunoglobulin G concentration decreased from 15.4 at day 42 to 0.03 after 24 months in HIV-exposed, uninfected infants.

CONCLUSIONS

Clearance of HIV antibodies could take more than 18 months in a small number of perinatally exposed infants. Caution should be used in excluding or diagnosing perinatal HIV infection in children with long persistence of HIV antibodies.

[Epidemiological characteristics of malaria in Henan Province from 1950 to 2019]

OBJECTIVE

To analyze the epidemiological characteristics of malaria in Henan Province from 1950 to 2019, so as to provide the scientific evidence for consolidating malaria elimination achievements in the province.

METHODS

The epidemiological situation of malaria and demographic data in Henan Province from 1950 to 2019 were collected, and the statistical analyses were performed using a descriptive epidemiological method. The spatial temporal distribution of malaria cases was identified using the software ArcGIS version 10.3.

RESULTS

During the period from 1950 through 2019, the progress of malaria elimination was divided into 4 stages in Henan Province, including the baseline-survey and key-control stage, morbidity-control and incidence-reduction stage, basic-eradication and achievement-consolidation stage and elimination stage. The spatial distribution of malaria cases shifted from south of the Huai River and the plain regions between the Yellow River and Taihang Mountain to the Huang-Huai-Hai Plain and Nanyang Basin, then was concentrated in eastern part of southern Huai River where Anopheles anthropophagus was distributed, and finally was gradually under control following malaria outbreak in Eastern Henan Plain. In addition, the species of Plasmodium changed from P. vivax, P. falciparum and P. malariae co-endemics to a single P. vivax infection, and the current co-endemics of 5 invasive malaria parasites, and the malaria vectors shifted from co-existence of Anopheles sinensis and An. anthropophagus to An. sinensis alone.

CONCLUSIONS

There has been a large change in the epidemiological characteristics of malaria in Henan Province from 1950 to 2019. Although malaria has been eliminated in Henan Province, the consolidation of the malaria elimination achievements remain a great challenge due to overseas imported malaria.

[Diagnosis of imported malaria cases in Henan Province from 2015 to 2019]

OBJECTIVE

To analyze the diagnosis of imported malaria cases in Henan Province from 2015 to 2019, so as to provide the evidence for malaria surveillance during the post-elimination stage.

METHODS

The data pertaining to malaria cases in Henan Province from 2015 to 2019 were extracted via the web-based Chinese Information System for Infectious Diseases Control and Prevention and the Parasitic Diseases Information Reporting Management System (PDIRMS) of Chinese Center for Disease Control and Prevention, and the diagnostic methods, diagnostic institutions and diagnostic time of imported malaria cases were analyzed.

RESULTS

A total of 952 imported malaria cases were reported in Henan Province during the period from 2015 through 2019, and all cases were laboratory-confirmed. The positive rate of malaria rapid diagnostic tests (RDTs) was 98.61% (779/790), which was significantly greater than that (94.22%, 897/952) of microscopic examinations (χ² = 22.773, P < 0.05). The proportion of imported malaria cases diagnosed in medical institutions increased from 65.22% (120/184) in 2015 to 81.50% (185/227) in 2019. Among the 238 imported malaria cases diagnosed in centers for disease control and prevention (CDC), 71.01% (169/238) were diagnosed in county-level CDC, and among the 704 cases diagnosed in medical institutions, only 8.38% (59/704) were diagnosed at county-level medical institutions. The median time from onset to definitive diagnosis of malaria was 3 days, and the median duration between onset and initial diagnosis of malaria was 1 day. The duration between initial diagnosis and definitive diagnosis of malaria varied significantly among years (χ² = 24.956, P < 0.05), and the interquartile range from initial diagnosis to definitive diagnosis reduced from 4 days in 2016 to 2 days in 2019. In addition, the median time from initial diagnosis to definitive diagnosis was significantly longer in severe falciparum malaria cases than in non-severe falciparum malaria cases (2 days vs. 1 day; Z = 7.557, P < 0.05).

CONCLUSIONS

Medical institutions play a more and more important role in the identification and surveillance of malaria cases; however, the diagnostic capability of malaria remains low in county-level medical institutions. The diagnostic awareness and capability of county-level medical institutions requires to be improved, in order to play their roles as sentinel hospitals in the malaria surveillance during the post-elimination stage.

[Epidemic status of malaria and progress of malaria elimination in Henan Province, 2018]

OBJECTIVE

To understand the epidemic status of malaria and progress of malaria elimination in Henan Province in 2018, so as to provide the scientific evidence for formulating the control strategy of malaria.

METHODS

All data pertaining to the epidemic status of malaria and malaria case were captured from Henan Province in 2018, and the epidemic status of malaria and the diagnosis and treatment of malaria cases were analyzed using a descriptive epidemiological method.

RESULTS

A total of 174 malaria cases were reported in Henan Province in 2018, with a male-to-female ratio of 33.8∶1. The cases were predominantly found at 30- and 40- years, and farmer was the highest-risk population. All cases were imported for overseas countries and 96.55% (168/174) were from Africa. The cases were reported across 17 cities of the province, and 63.22% (110 cases) were detected in 4 cities of Zhengzhou, Luoyang, Xuchang and Puyang. Both the median duration from onset to initial admission and the median time from the initial admission to definitive diagnosis were 1 d. There were 6 cases (3.45%) with more than 7 days to visit a doctor, and there were 13 cases (7.47%) with definitive diagnosis of over 7 days (delay in definitive diagnosis). All malaria cases were reported within 24 h, and 98.28% (171/174) completed case investigations within 3 d. All 18 cities had achieved malaria elimination by December 2018.

CONCLUSIONS

All malaria cases reported in Henan Province in 2018 are imported from overseas countries. Intensifying malaria surveillance among returnees from Africa and Southeast Asia and timely identification and treatment of imported malaria cases are required to prevent the development of secondary malaria cases, so as to ensure the achievement of malaria elimination in Henan Province on schedule.

Twisted Magnon as a Magnetic Tweezer

Wave fields with spiral phase dislocations carrying orbital angular momentum (OAM) have been realized in many branches of physics, such as for photons, sound waves, electron beams, and neutrons. However, the OAM states of magnons (spin waves)-the building block of modern magnetism-and particularly their implications have yet to be addressed. Here, we theoretically investigate the twisted spin-wave generation and propagation in magnetic nanocylinders. The OAM nature of magnons is uncovered by showing that the spin-wave eigenmode is also the eigenstate of the OAM operator in the confined geometry. Inspired by optical tweezers, we predict an exotic "magnetic tweezer" effect by showing skyrmion gyrations under twisted magnons in the exchange-coupled nanocylinder-nanodisk heterostructure, as a practical demonstration of magnonic OAM transfer to manipulate topological spin defects. Our study paves the way for the emerging magnetic manipulations by harnessing the OAM degree of freedom of magnons.

High-order least-square-based finite-difference-finite-volume method for simulation of incompressible thermal flows on arbitrary grids

In this work, a high-order (HO) least-square-based finite difference-finite volume (LSFD-FV) method together with thermal lattice Boltzmann flux solver (TLBFS) is presented for simulation of two-dimensional (2D) incompressible thermal flows on arbitrary grids. In the present method, a HO polynomial based on Taylor series expansion is applied within each control cell, where the unknown spatial derivatives at each cell center are approximated by least-square-based finite difference (LSFD) scheme. Then the recently developed TLBFS is applied to evaluate the convective and diffusive fluxes simultaneously at the cell interface by local reconstruction of thermal lattice Boltzmann solutions of the density and internal energy distribution functions. The present HO LSFD-FV method is verified and validated by 2D incompressible heat transfer problems. Numerical results indicate that the present method can be effectively and flexibly applied to solve thermal flow problems with curved boundaries on arbitrary grids. Compared with the conventional low-order finite volume method, higher efficiency and lower memory cost make the present HO method more promising for practical thermal flow problems.

[Prevalence and influencing factors of intestinal parasitic diseases among rural children in Henan Province]

OBJECTIVE

To understand the epidemic status and influencing factors of intestinal parasitic diseases among rural children in Henan Province.

METHODS

According to the Scheme for The National Survey on Current Status of Major Human Parasitic Diseases in China, the survey counties were selected based on the ecological zones and economic levels in Henan Province between 2014 and 2015. Then, the included counties were stratified according to the topography and economic levels. A township was randomly sampled from each stratum, and a village was randomly sampled from each township as the study site. Finally, a total of 104 study sites from 35 counties were enrolled for the survey of intestinal parasitic diseases in children. At least 250 fresh stool samples were collected from each study site for detection of intestinal helminth eggs with the Kato-Katz technique, for the identification of Necator americanus and Ancylostoma duodenale with the fecal culture method, and for the detection of intestinal protozoa trophozoite and cyst with the physiological saline smear and iodine staining techniques. In addition, the Enterobius vermicularis and tapeworm eggs were detected in children aged 3 to 6 years using the adhesive cellophane-tape perianal swab method.

RESULTS

The overall prevalence of intestinal parasitic infections was 3.21% (214/6 671) among rural children in Henan Province, and the prevalence of intestinal helminthes (2.62%, 175/6 671) was higher than that of intestinal protozoa (0.60%, 40/6 671). A total of 12 species of intestinal parasites were found, including 4 nematodes species, one trematode species, and 7 protozoa species, and the highest infection was seen in E. vermicularis (2.47%, 161/6 671). Among the four ecological zones in Henan Province, the greatest prevalence of intestinal parasitic infections was detected among children in the Qinba Mountain Ecological Zone (5.85%, 90/1 538). There was no gender-specific difference in the prevalence of intestinal parasitic infections in children (P > 0.05); however, there were age- (χ² = 32.762, P < 0.05) and education level-specific differences in the prevalence of intestinal parasitic infections in children (χ² = 67.507, P < 0.05), with the greatest prevalence of E. vermicularis infection seen in all species of intestinal parasites in children at all age groups. Multivariate non-conditional logistic regression analysis showed that high education level, high coverage of harmless toilets, drinking tap water and deworming were protective factors for intestinal parasitic infections in children in Henan Province. The overall prevalence of intestinal parasitic infections appeared a tendency towards a gradual decline among children in Henan Province as compared to the previous two surveys.

CONCLUSIONS

The overall prevalence of intestinal parasitic infections shows a tendency towards a remarkable decline among children in Henan Province. E. vermicularis infection should be given a priority for future parasitic disease control activities among rural children in Henan Province.

Intracellular metabolism and potential cardiotoxicity of a β-D-2'-C-methyl-2,6-diaminopurine ribonucleoside phosphoramidate that inhibits hepatitis C virus replication

β-D-2'-C-Methyl-2,6-diaminopurine ribonucleoside (2'-C-Me-DAPN) phosphoramidate prodrug (DAPN-PD) is a selective hepatitis C virus inhibitor that is metabolized intracellularly into two active metabolites: 2'-C-Methyl-DAPN triphosphate (2'-C-Me-DAPN-TP) and 2'-C-methyl-guanosine 5'-triphosphate (2'-C-Me-GTP). BMS-986094 and IDX-184 are also bioconverted to 2'-C-Me-GTP. A phase IIb clinical trial with BMS-986094 was abruptly halted due to adverse cardiac and renal effects. Herein, we developed an efficient large scale synthesis of DAPN-PD and determined intracellular pharmacology of DAPN-PD in comparison with BMS-986094 and IDX-184, versus Huh-7, HepG2 and interspecies primary hepatocytes and human cardiomyocytes. Imaging data of drug treated human cardiomyocytes was found to be most useful in determining toxicity potential as no obvious beating rate change was observed for IDX-184 up to 50 µM up at 48 h. However, with BMS-986094 and DAPN-PD at 10 µM changes to both beat rate and rhythm were noted.

P3645Prognosis in relation to high-sensitivity C-reactive protein levels in patients with non-obstructive coronary artery disease

Background

It has been reported that coronary artery disease (CAD) is characterized by inflammation and non-obstructive CAD (NOCAD) increases the risk of cardiovascular events (CVEs) compared with ones with normal or near-normal coronary arteries (NNCA), even is similar to obstructive CAD (OCAD). We hypothesized that elevated high-sensitivity C-reactive protein (hs-CRP) may be linked to CVEs in those patients with NOCAD.

Purpose

To investigate the predictive role of hs-CRP in patients with NOCAD.

Methods

Of 7,746 consecutive patients with angina-like chest pain admissions, 4,662 eligible patients were enrolled who received coronary artery angiography (CAG) and followed up for the CVEs comprising all-cause mortality, myocardial infarction, stroke and late revascularization. According to the results of CAG, the patients were classified as NNCA group (<20% stenosis, n=698, 15.0%), NOCAD group (20–49% stenosis, n=639, 14.3%), and OCAD group (≥50% stenosis, n=3325, 70.7%). They were further subdivided into 3 groups according to baseline hs-CRP levels (<1, 1–3 and >3 mg/L). Proportional hazards models were used to assess the risk of CVEs in all patients enrolled.

Results

A total of 338 patients (7.3%) experienced CVEs during an average of 13403 person-years follow-up. Patients with NOCAD and OCAD had higher rates of CVEs compared to those with NNCA (p<0.05, respectively). In Cox's models after adjustment of confounders, the risk of CVEs elevated with the increasing degrees of CAD with hazard ratio of 2.01 [95% confidence interval (95% CI): 1.07–3.79, p=0.03] for patients with NOCAD and 2.81 (95% CI: 1.60–4.93, p<0.001) for patients with OCAD compared with the NNCA group. Moreover, elevated hs-CRP levels were associated with the severity of coronary lesions and an elevated increased risk of CVEs in patients with NOCAD and OCAD compared those with NNCA (p<0.05, respectively).

Conclusions

Patients with NOCAD had indeed worse outcomes and hs-CRP levels were positively in relation to the CVEs in those with NOCAD, which may help to the risk assessment in ones with NOCAD.

Acknowledgement/Funding

This study was partly supported by Capital Health Development Fund (201614035) and CAMS Innovation Fund for Medical Sciences (2016-I2M-1-011) awarded

Novel influenza polymerase PB2 inhibitors for the treatment of influenza A infection

Exploration of the chemical space of known influenza polymerase PB2 inhibitor Pimodivir, was performed by our group. We synthesized and identified compounds 16a and 16b, two novel thienopyrimidine derivatives displaying anti-influenza A activity in the single digit nanomolar range in cell culture. Binding of these unique compounds in the influenza polymerase PB2 pocket was also determined using molecular modeling.

[Relationship between plasma fibroblast growth factor-23 and subclinical cardiovascular damages in children with primary hypertension]

Objective: To examine the plasma fibroblast growth factor-23 (FGF-23) concentration in children with primary hypertension and to investigate the association between plasma FGF-23 and subclinical cardiovascular damages,and to identify its predictive value for diagnosis. Methods: With prospective study,77 patients (61 males and 16 females) who were diagnosed as primary hypertension with the average age of (11.8±2.2) years were enrolled with informed consent in Children's Hospital,Capital Institute of Pediatrics from October 2016 to December 2017. Carotid wall intima-media thickness (cIMT) measured by Doppler ultrasound and left ventricular hypertrophy (LVH) identified by echocardiography were assessed as parameters of subclinical cardiovascular damages. Patients were divided into increased cIMT group (n=18) and normal cIMT group (n=46) (64 patients with complete data of cIMT). According to left ventricular geometry,patients were divided into LVH group (n=27) and normal geometry group (n=50). Concentration of plasma FGF-23 was detected in all children by enzyme linked immunosorbent assay test. Mann-Whitney U test was used to compare plasma levels of FGF-23 between groups. Kendall's tau-b correlation coefficient was used to analyze the correlation between plasma FGF-23 and cIMT/LVH. Receiver operating characteristic (ROC) curve was used to analyze the value of plasma FGF-23 in the prediction of subclinical cardiovascular damage. Results: The concentration of plasma FGF-23 in the increased cIMT group was higher than that in the normal cIMT group (55.6 (46.2,63.5) vs. 48.6 (39.4, 57.3) ×10(3) RU/L, Z=-2.143, P=0.032) . Also, plasma FGF-23 showed positive correlation with cIMT(r=0.222, P=0.032). According to ROC curve analysis,the cutoff value of plasma FGF-23 for prediction of increased cIMT was 53.9×10(3) RU/L (55.6% sensitivity and 71.7% specificity). The concentration of plasma FGF-23 in the LVH group was significantly higher than that in normal geometry group (55.0 (46.8, 65.7) vs. 48.2 (39.5, 56.0)×10(3) RU/L, Z=-2.375, P=0.018). And,plasma FGF-23 was correlated positively with LVH (r=0.224, P=0.018). The concentration of plasma FGF-23 in patients with concentric remodeling (n=10) was significantly higher than that of the normal geometry group (56.9 (49.6, 66.3) vs. 48.2 (39.5,56.0) ×10(3) RU/L, Z=-2.093, P=0.036). According to ROC curve analysis,the cutoff value of plasma FGF-23 for prediction of LVH was 49.1×10(3) RU/L (70.4% sensitivity and 60.0% specificity). Conclusion: The concentration of plasma FGF-23 in children with primary hypertension was correlated positively with LVH and cIMT and had certain predictive value of diagnosis for subclinical cardiovascular damages.

[Application of modified Dix-Hallpike maneuver in the diagnosis of posterior semicircular canal benign paroxysmal positional vertigo]

Objective:To investigate the application of modified Dix-Hallpike maneuver in the diagnosis of posterior semicircular canal benign paroxysmal positional vertigo. Method:The modified Dix-Hallpike maneuver, supine roll maneuver and classical Dix-Hallpike maneuver were performed respectively. The sensitivity and specificity of modified and classical Dix-Hallpike maneuver in the diagnosis of posterior semicircular canal BPPV was compared. Result:Fifty-five posterior semicircular canal BPPV patients showed both modified and classical Dix-Hallpike maneuver positive result, including 12 cases of rotational nystagmus induced by ipsilateral supine roll maneuver. Conclusion:Modified Dix-Hallpike maneuver and classical Dix-Hallpike maneuver have the same effect on the diagnosis of posterior semicircular canal BPPV, but the former is easy to the operation, nystagmus observation and result judgment, and is conducive to the promotion of use..

Genetic mutation analysis of plasma circulating tumor DNA by ultra-deep sequencing in breast benign lesions and cancers

e14572

Background: Mammography screening for breast cancer results in large number of impalpable lesions without clear determination of the malignancy. Analysis of breast cancer related gene mutations in blood circulating tumor DNA (ctDNA) may provide clarification. This analysis aims to provide insights into the feasibility of the approach. Methods: The clinical trial was conducted at top tier teaching hospitals in China to recruit patients with breast diseases for surgery. Eligible patients were consented and the breast lesions were pathologically diagnosed. Peripheral blood was collected prior to surgical resection. For breast cancer patients, samples of resected tissue were also collected. The samples were analyzed using our proprietary NGS technique called systematic error correction sequencing (Sec-Seq) (detailed in Abstract ##e23057, ASCO 2018). Results: In total, 69 patients with breast lesions (57 malignant and 12 benign) were included in this analysis. Tumor gDNA and plasma ctDNA were analyzed by deep NGS sequencing using a panel of 62 breast cancer-associated genes. The average sequencing depth is 35000. After deduplication, the average number of unique reads is 1500. Detection limit for mutant allele frequency was set at 0.2% for ctDNA and 1% for tumor tissue. For ctDNA mutation detection, 2 out of 12 patients with benign diseases were found with mutations while 10 out of 55 breast cancer patients had no mutations, resulting in an overall sensitivity of 82% and specificity of 83%. By cancer stage, the two Stage 0 (carcinoma in situ) patients had no mutation, and the range of mutations detected is between 53% to 75% from Stage I to III. The tumor tissue samples have higher rate of mutations (only 2 cancer patients, 1 Stage 0 and 1 Stage 2, had no mutations). 15% patients have at least one common mutation detected in both the tumor tissue and ctDNA, and 27% patients have mutations in the same genes in the two matching samples. The concordance increases as the clinical stage advances. The most commonly mutated genes are previously reported breast cancer drivers of PIK3CA (79% of tumor and 18% of ctDNA samples), TP53 (56% and 39%), and BRCA1 (6% and 15%). Conclusions: In this hypothesis generating analysis, we showed the feasibility of plasma ctDNA sequencing for gene mutation detection in early stage breast cancer and differentiation from the benign breast diseases. Although with limited number of samples, the data encourage further improvement of the gene panel and the validation of ctDNA assay as a non-invasive approach to the cancer screening. Clinical trial information: ChiCTR1800017345.