[Analysis on the cluster epidemic of coronavirus disease 2019 in Guangdong Province]

Objective: Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province. Methods: The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared. Results: A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M (P₂₅, P₇₅) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant (P=0.003). Conclusion: COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

Display of quintuple glucagon-like peptide 1 (28-36) nonapeptide on Bacillus subtilis spore for oral administration in the treatment of type 2 diabetes

AIMS

To develop an oral delivery system of glucagon-like peptide 1 (GLP-1) (28-36) for treating type-2 diabetes, B.S-GLP-1(28-36), a recombinant Bacillus subtilis spores transformed with a plasmid vector encoding five consecutive GLP-1 (28-36) nonapeptides with an enterokinase site was constructed.

METHODS AND RESULTS

GLP-1(28-36) nonapeptide was successfully expressed on the surface of B. subtilis spores and validated by Western blot and immunofluorescence. The therapeutic effect of oral administration of B.S-GLP-1(28-36) spores was evaluated in type 2 diabetic model mice. The efficacy of recombinant spores was examined for a period of 13 weeks after oral administration in diabetic mice. At the end of the sixth week, diabetic mice with oral administration of BS-GLP-1(28-36) spores showed decreased blood glucose levels from 2·4 × 10^{- 2}  mol l^-1 to 1·7 × 10^{- 2}  mol l^-1 . By the ninth week, the mean fasting blood glucose level in the experimental group was significantly lower than that in the control group 30 min after injection of pyruvate. At the end of the 10th week of oral administration, the blood glucose of the experimental group was significantly lower than that of the control group after intraperitoneal injection of glucose. By the 12th week, fasting blood glucose level and fasting insulin level were measured in all mice, the results showed that the recombinant spores increased the insulin sensitivity of mice.

CONCLUSIONS

The results of pathological observation showed that the recombinant spores also had a certain protective effect on the liver and islets of mice, and the content of GLP-1(28-36) in the pancreas of the experimental group was increased.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study revealed that GLP-1(28-36) nonapeptides can reduce blood glucose and play an important role in the treatment of type 2 diabetes.

Mechanoadaptive strain and functional osseointegration of dental implants in rats

Spatiotemporal implant-bone biomechanics and mechanoadaptive strains in peri-implant tissue are poorly understood. Physical and chemical characteristics of an implant-bone complex (IBC) were correlated in three-dimensional space (along the length and around a dental implant) to gather insights into time related integration of the implant with the cortical portion of a jaw bone in a rat. Rats (N = 9) were divided into three experimental groups with three rats per time point; 3-, 11-, and 24-day. All rats were fed crumbled hard pellets mixed with water (soft-food diet) for the first 3 days followed by a hard-food diet with intact hard-food pellets (groups of 11- and 24-day only). Biomechanics of the IBCs harvested from rats at each time point was evaluated by performing mechanical testing in situ in tandem with X-ray imaging. The effect of physical association (contact area) of a loaded implant with adapting peri-implant tissue, and resulting strain within was mapped by using digital volume correlation (DVC) technique. The IBC stiffness at respective time points was correlated with mechanical strain in peri-implant tissue. Results illustrated that IBC stiffness at 11-day was lower than that observed at 3-day. However, at 24-day, IBC stiffness recovered to that which was observed at 3-day. Correlative microscopy and spectroscopy illustrated that the lower IBC stiffness was constituted by softer and less mineralized peri-implant tissue that contained varying expressions of osteoconductive elements. Lower IBC stiffness observed at 11-day was constituted by less mineralized peri-implant tissue with osteoconductive elements that included phosphorus (P) which was co-localized with higher expression of zinc (Zn), and lower expression of calcium (Ca). Higher IBC stiffness at 24-day was constituted by mineralized peri-implant tissue with higher expressions of osteoconductive elements including Ca and P, and lower expressions of Zn. These spatiotemporal correlative maps of peri-implant tissue architecture, heterogeneous distribution of mineral density, and elemental colocalization underscore mechanoadaptive physicochemical properties of peri-implant tissue that facilitate functional osseointegration of an implant. These results provided insights into 1) plausible "prescription" of mechanical loads as an osteoinductive "therapeutic dose" to encourage osteoconductive elements in the peri-implant tissue that would facilitate functional osseointegration of the implant; 2) a "critical temporal window" between 3 and 11 days, and perhaps it is this acute phase during which key candidate regenerative molecules can be harnessed to accelerate osseointegration of an implant under load.

Severe cytomegalovirus gastritis after pembrolizumab in a patient with melanoma

Immunotherapy has emerged as a standard of cancer treatment, with an increasing number of indications. Recently, opportunistic infections have been reported in several cases in which immunotherapy has led to an increased susceptibility to infection. The present case is the first report of cytomegalovirus (cmv) gastritis occurring in a patient with melanoma during immunotherapy without immune-related adverse events (iraes) and without the use of immunosuppressant agents. A 43-year-old woman presented with stage iii malignant melanoma. She underwent wide excision of skin, with lymph node dissection, and she started immunotherapy with a 3-week cycle of pembrolizumab. The patient demonstrated stable disease response, and no iraes were observed during her initial treatment courses. However, after the 9th treatment cycle, she began to experience epigastric pain that worsened significantly, requiring a visit to the emergency centre. Imaging by computed tomography (ct) and integrated positron-emission tomography/ct revealed severe diffuse gastroduodenitis with acute pancreatitis. Esophagogastroduodenoscopy showed diffuse oozing, hemorrhagic, edematous, and exfoliative mucosa involving the entire gastric wall, defined as acute hemorrhagic gastritis. Biopsies of the gastric wall revealed cmv infection. Those findings were consistent with a diagnosis of cmv gastritis, and the patient received antiviral therapy with ganciclovir. After treatment, she recovered enough to resume immunotherapy. This case report presents a rare occurrence of cmv gastritis related to immunotherapy. As more patients are treated with immunotherapy, incidences of cmv infections are expected to increase; a high index of clinical suspicion is therefore needed in symptomatic patients.

Data on biomechanics and elemental maps of dental implant-bone complexes in rats

Implant-bone biomechanics and mechanoadaptation of peri‑implant tissue in space (around and along the length of an implant) and time (3-, 11-, and 24-day following implantation) are important for functional osseointegration of dental implants. Spatiotemporal shifts in biomechanics of implant-bone complex in rat maxillae were correlated with maximum (tensile) and minimum (compressive) principal strain profiles in peri‑implant tissue using a hybrid model; biomechanics in situ paired with digital volume correlation. Spatiotemporal changes in elemental counts and their association with mineral density of the peri‑implant tissue were mapped using electron dispersive X-ray and X-ray fluorescence microprobe techniques. Data provided within are related to biomechanical testing of an implant-bone complex in situ. Data also highlight the power of correlating elemental colocalization with tension and compression regions of the peri‑implant tissues to explain spatiotemporal mechanoadaptation of implant-bone complexes. Further interpretation of data is provided in "Mechanoadaptive Strain and Functional Osseointegration of Dental Implants in Rats [1]."

Commissioning and beam characterization of the first gantry-mounted accelerator pencil beam scanning proton system

PURPOSE

To present and discuss beam characteristics and commissioning process of the first gantry-mounted accelerator single room pencil beam scanning (PBS) proton system.

METHODS

The Mevion HYPERSCAN employs a design configuration with a synchrocyclotron mounted on the gantry to eliminate the traditional beamline and a nozzle that contains the dosimetry monitoring chambers, the energy modulator (Energy Selector (ES)), and an Adaptive Aperture (AA). To characterize the beam, we measured the integrated depth dose (IDDs) for 12 energies, from highest energy of 227 MeV down to 28 MeV with a range difference ~ 2 cm between the adjacent energies, using a large radius Bragg peak chamber; single-spot profiles in air at five locations along the beam central axis using radiochromic EBT3 film and cross compared with a scintillation detector; and determined the output using a densely packed spot map. To access the performance of AA, we measured interleaf leakage and the penumbra reduction effect. Monte Carlo simulation using TOPAS was performed to study spot size variation along the beam path, beam divergence, and energy spectrum.

RESULTS

This proton system is calibrated to deliver 1 Gy dose at 5 cm depth in water using the highest beam energy by delivering 1 MU/spot to a 10 × 10 cm² map with a 2.5 mm spot spacing. The spot size in air varies from 4 mm to 26 mm from 227 MeV to 28 MeV at the isocenter plane with the nozzle retracted 23.6 cm from isocenter. The beam divergence of 28 MeV beam is ~ 52.7 mrad, which is nearly 22 times that of 227 MeV proton beam. The binary design of the ES has resulted in shifts of the effective SSD toward the isocenter as the energy is modulated lower. The peaks of IDD curves have a constant 80%-80% width of 8.4 mm at all energies. The interleaf leakage of the AA is less than 1.5% at the highest energy; and the AA can reduce the penumbra by 2 mm to 13 mm for the 227 and 28 MeV energies at isocenter plane in air.

CONCLUSIONS

The unique design of the HYPERSCAN proton system has yielded beam characteristics significantly different from that of other proton systems in terms of the Bragg peak shapes, spot sizes, and the penumbra sharpening effect of the AA. The combination of the ES and AA has made PBS implementation possible without using beam transport line and range shifter devices. Different considerations may be required in treatment planning optimization to account for different design and beam characteristics.

Combined effects of acute exercise and hypoxia on memory

No previous studies have evaluated the potential combined effects of acute exercise and acute hypoxia exposure on memory function, which was the purpose of this study. Twenty-five participants (Mage = 21.2 years) completed two laboratory visits in a counterbalanced order, involving 1) acute exercise (a 20-min bout of moderate-intensity exercise) and then 30 min of exposure to hypoxia (FIO2 = 0.12), and 2) exposure to hypoxia alone (FIO2 = 0.12) for 30 min. Following this, participants completed a cued-recall and memory interference task (AB/AC paradigm), assessing cued-recall memory (recall 1 and recall 2) and memory interference (proactive and retroactive interference). For cued-recall memory, we observed a significant main effect for condition, with Exercise + Hypoxia condition having significantly greater cued-recall performance than Hypoxia alone. Memory interference did not differ as a function of the experimental condition. This experiment demonstrates that engaging in an acute bout of exercise prior to acute hypoxia exposure had an additive effect in enhancing cued-recall memory performance.

Short communication: Dietary bovine milk-derived exosomes improve bone health in an osteoporosis-induced mouse model

Osteoporosis is a systemic skeletal disease characterized by low bone mass and micro-architectural deterioration of bone tissue, with a consequent increase in bone fragility and fracture susceptibility. In an aged society with increased life expectancy, the incidence rate of osteoporosis is also rapidly increasing. Inadequate nutrition may negatively influence bone metabolism. Recently, many studies have investigated the functionality of milk-derived exosomes, which play important roles in cell-to-cell communication. However, there are few reports of how milk-derived exosomes influence osteoblast proliferation and differentiation. Here, we determined whether bovine colostrum-derived exosomes promote anti-osteoporosis in vitro and in vivo. Tartrate-resistant acid phosphatase-stained cells were significantly inhibited in Raw264.7 cells treated with exosomes, indicating reduced osteoclast differentiation. We induced osteoporosis in mice using glucocorticoid pellets after orally administering exosomes for 2 mo. Interestingly, the bone mineral density of exosome-fed mouse groups was significantly improved compared with the glucocorticoid-induced osteoporosis group without exosome treatment. In addition, Lactobacillus were decreased in the gut microbiota community of osteoporosis-induced mice, but the gut microbiota community composition was effectively restored by exosome intake. Taken together, we propose that exosomes isolated from bovine colostrum could be a potential candidate for osteoporosis prevention, bone remodeling improvement, and inhibition of bone resorption. To our knowledge, this is the first time that a protective effect of milk exosomes against osteoporosis has been demonstrated in vivo. Our results strongly suggest that bovine colostrum exosomes might be used as a prophylaxis to prevent the onset of osteoporosis. Indeed, our results offer promising alternative strategies in the nutritional management of age-related bone complications.

Adult mesenchymal stem cells and their exosomes: Sources, characteristics, and application in regenerative medicine

Human mesenchymal stem cells (MSCs) have become a hot topic in the development of cell therapies and bioengineering. All kinds of MSCs are genomic stable and have the self-renewal ability. Main sources of MSCs are bone marrow, adipose tissues, umbilical cord and placental tissues. MSCs can be cultured in many undifferentiated passages to grow into more specialized cells, produce secretory factors and also support trophic functions in the body. Exosomes, derived from MSCs also have great potential in regenerative medicine and tissue engineering. Exosomes are secreted by MSCs and have the same therapeutic potential as their parent cells. MSCs and their exosomes combined with biomaterials can also be more effective in promoting the regeneration of tissues and organs. However, for use of MSCs-exosomes as a clinical agent different MSCs-exosomes have been manufactured and their therapeutics effects demonstrated in clinical studies. But there are still many characteristics which are unknown and many barriers still need to be conquered. In this review, we not only highlighted the characteristics of human MSCs and their exosomes, but also provided their latest therapeutic strategies in regenerative medicine.

Nanorectenna spectrally-selective plasmonic hot electron response to visible-light lasers

Active metasurfaces with novel visible and infrared (vis/IR) functionalities represent an exciting, growing area of research. Rectification of vis/IR frequencies would produce needed direct current (DC) with no inherent frequency limitation (e.g. no semiconducting bandgap). However, controlling the materials and functionality of (nano)rectennas for rectifying 100 s of THz to the visible regime is a daunting challenge, because of the small features and simultaneously the need to scale up to large sizes in a scalable platform. An active metasurface of a planar array of nanoscale antennas on top of rectifying vertical diodes is a 'nanorectenna array' or 'microrectenna array' that rectifies very high frequencies in the infrared, or even higher frequencies up to the visible regime. We employ a novel strategy for forming optical nanorectenna arrays using scalable patterning of Au nanowires, demonstrate strong evidence for spectral-selective high-frequency rectification, characteristic of optical antennas. We discover a previously unreported out-of-equilibrium electron energy distribution, i.e. hot electrons arising from plasmonic resonance absorption in an optical antenna characterized by an effective temperature, and how this effect can significantly impact the observed rectification.

[Survey on the quadrivalent influenza vaccine intention and related factors of health care workers in the Pearl River Delta region from 2015 to 2017]

Objective: To analyze the quadrivalent influenza vaccine intention of 718 health care workers (HCWs) in the Pearl River Delta region from 2015 to 2017. Method: In May 2018, 718 HCWs from the department related to the diagnosis and treatment of influenza in 17 hospitals (6 tertiary hospitals, 5 secondary hospitals and 6 primary hospitals) from Guangzhou, Jiangmen, Zhuhai and Dongguan were selected by using stratified sampling method. Questionnaire survey and face-to-face interview were used to collect the information of influenza vaccination, the intention of the quadrivalent influenza vaccine, the acceptance of free and required vaccination policies, and recommendations for increasing influenza vaccination intentions from 2015 to 2017. The multivariate logistic regression was used to analyze factors associated with the vaccination intention. Results: A total of 718 HCWs were surveyed and 147 of them were interviewed face to face. Among them, the vaccination rate of primary hospitals [17.39%(40/230)] was higher than that of other hospitals (χ(2)=15.80, P<0.05). If the vaccine could be free, 84.82% (609/718) of HCWs would like to be vaccinated. The multivariate logistic regression showed that the factors, HCWs who were aged ≥50 years (OR=3.44, 95%CI:1.43-8.28), worked in department of prevention and health care (OR=2.35, 95%CI:1.16-4.75), learned about the quadrivalent influenza vaccine (OR=2.94, 95%CI:2.08-4.18), knowed that HCWs are priority (OR=2.33, 95%CI:1.56-3.48), and had a history of trivalent influenza vaccination from 2015 to 2017 (OR=4.70, 95%CI:3.08-7.15), were associated with the vaccination intention. Conclusion: HCWs in the Pearl River Delta region had weak inclination of getting quadrivalent influenza vaccine. HCWs who were age (≥50 years old), worked in department of prevention and health care, learned about the quadrivalent influenza vaccine, knowed that HCWs are priority, and had a history of trivalent influenza vaccination from 2015 to 2017 were factors positively associated with the vaccination intention.

[Analysis on epidemiological characteristics of enterovirus 71 cases of hand-foot-mouth disease based on the active monitoring in Guangdong Province in 2011-2015]

Objective: To analyze the hand-foot-mouth disease (HFMD) enterovirus 71 (EV-A71) infection epidemic characteristics of Guangdong Province from 2011 to 2015. Methods: We colleted data on common cases of hand-foot-mouth disease infected with EV-A71 reported from eight sentinel hospitals in Guangdong Province from January 2011 to December 2015, through the "Guangdong Province Acute Infectious Disease Surveillance Information Platform System" , including the age and incidence of cases. Time and etiological data, etc.We also collected data on the number of reported cases of HFMD disease and the number of laboratory-confirmed cases, through the "China Disease Prevention and Control Information System" , including data on common cases of HFMD disease, data on epidemics of severe cases and deaths, and the age, onset time, and pathogens of cases. Learning data, etc.The data from two sources were used to estimate the incidence of HFMD in EV-A71 and describe its distribution characteristics.Chi-square test was used to compare the positive rate of HF-A71 infection in hand-foot-mouth disease and the difference in estimated incidence among different age groups and months. Results: Eight sentinel hospitals from 2011 to 2015 reported a total of 1 855 common cases of EV-A71 infection, of which the highest was in 2014 (31.6%, 605/1 916) and the lowest was in 2015 (6.8%, 134/1 971) (χ(2)=521.85, P<0.001).According to the Disease Surveillance Reporting Information System, 1 772 516 cases of HFMD disease were reported from 2011 to 2015 in Guangdong Province, and 1 902 cases of severe and fatal cases of EV-A71 infection.The composition ratio of EV-A71 infected was 72.6% (1 775/2 444) and 97.0% (127/131) of severe HFMD disease in Guangdong province during 2011-2015.The average annual incidence of HF-A71 infection in all age groups showed a decreasing trend with age (χ(2trend)=990 273.20, P<0.001), and it was the highest in the 1-year-old group, which was 1 697.67/100 000, and the lowest in the 4-year-old group, which was 705.46/100 000. The difference of monthly average incidence of EV-A71 infection in HF-A71 in each month was statistically significant (χ(2)=401.23, P<0.001), the highest in May at 15.51 per 100 000, and the lowest in July at 9.42 per 100 000. Conclusion: EV-A71 infection rate of ordinary HFMD varies in different years. The most severe and death cases of HFMD were EV-A71 infected. 1 year old children were the high-risk group of infected with EV-A71 HFMD. April was the epidemic months of EV-A71 HFMD infection.

[Technical guidelines for seasonal influenza vaccination in China, 2018-2019]

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications. Currently, China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. In most parts of China, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients need to pay for it. To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC), Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" , based on most recent existing scientific evidences. The main updates include: epidemiology and disease burden of influenza, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, and, IIV3 and IIV4 vaccines'major immune responses, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The recommendations include: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥1 licensed, recommended, and appropriate products. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to pregnant during the influenza season. Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in previous influenza season, 1 dose is recommended. People ≥ 9 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for CDC members who are working on influenza control and prevention, PoVs members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and members of maternity and child care institutions at all levels.

[Technical guidelines for seasonal influenza vaccination in China (2018-2019)]

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and complications from infection. Currently, China has licensed trivalent inactivated influenza vaccine (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. Except for a few major cities, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients must pay for it. To strengthen the technical guidance for prevention and control of influenza and operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC) Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" . The main updates in this version include: epidemiology, disease burden, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, IIV3 and IIV4 immune response, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The influenza vaccine TWG provided the recommendations for influenza vaccination for the 2018-2019 influenza season based on existing scientific evidence. The recommendations described in this report include the following: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended, and appropriate product is available. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-59 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to become pregnant during the influenza season. Children aged 6 months through 8 years require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in 2017-2018 influenza season or a prior season, 1 dose is recommended. People more than 8 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. For the people unable to be vaccinated before the end of October, influenza vaccination will continue to be offered for the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for use by staff members of the Centers for Disease Control and Prevention at all levels who work on influenza control and prevention, PoVs staff members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and staff members of maternity and child care institutions at all levels.

[Epidemiological characteristics of influenza in Guangdong province, during winter of 2017-2018]

Objective: To understand the epidemiological characteristics of influenza in Guangdong province, during the winter of 2017-2018, to provide evidence for response to the diversity of influenza, in different seasonal patterns. Methods: Data on weekly influenza surveillance from January 2016 to April 2018, were collected in Guangdong. Information on patients with Influenza-like illness (ILI), on influenza virus positive rates and on outbreaks during the winter of 2017 to 2018, was analyzed and compared with those in spring of 2016 and summer of 2017. χ(2) test and Fisher exact test were used. Results: In the above said winter, the average percentage of visits for ILI in 28 hospitals where sentinel surveillance program had been set, was 4.99% (157 235/3 149 656), which was above the level of the same period in the previous five years. The positive rates of influenza virus among samples collected from ILI outpatients and hospitalized cases under severe acute respiratory infection (SARI) were 28.33% (2 137/7 543) and 14.93% (256/1 715), with the proportions of B (Yamagata) as 70.43% (1 505/2 137) and 73.05% (187/256) respectively. A total of 257 influenza outbreaks were reported in the winter period, with 82.49% (212/257) occurred in elementary schools. Cases aged 6-14 years occurred in winter and spring appeared of having higher positive rate than those seen in summer (P<0.05) whereas elderly cases aged 60 and above showed higher positive rate in summer than those in winter and spring two seasons (P<0.05). Conclusions: Epidemiological characteristics of influenza appeared in Guangdong province, during the winter from 2017 to 2018, were correlated to Influenza B (Yamagata). Capacity on the implementation of surveillance programs and on the coverage of vaccination should be improved and increased in order to control influenza in different epidemic seasons, in Guangzhou.

Pathogenesis of duck circovirus genotype 1 in experimentally infected Pekin ducks

Ducks infected with duck circovirus (DuCV) exhibit feathering disorder, growth retardation, and low body weight. The virus can induce immunosuppression and increase rates of infection caused by other pathogens. The purpose of the present study was to investigate the pathogenesis of DuCV in experimentally infected Pekin ducks. At postmortem examination, gross lesions were observed in the immune organs including bursa of Fabricius (BF), thymus, and spleen. Hemorrhage, lymphocytic depletion, necrosis, and degeneration were observed in the bursal tissues by histological examination. The TUNEL assay was performed with bursal tissue. There was a significant difference of the apoptosis rate between the negative and DuCV-infected ducks. The earliest time point for detection of DuCV DNA in sera, cloacal swabs, and organs was 1 wk post-infection (WPI). Viral shedding was persistent and detectable at the end of the experiment (10 WPI). The findings provide evidence that horizontal transmission and persistent infection are the characteristics of DuCV. The organ with the highest mean viral load was the spleen, followed by BF, cecal tonsil, lung, thymus, liver, and kidney. We successfully established an experimental DuCV genotype 1 (DuCV-1) infection in Pekin ducks and demonstrated the pathogenicity and persistence of DuCV-1. In conclusion, DuCV-1 caused extensive damage to the immune organs that may have resulted in immunosuppression. Pathobiological characteristics of DuCV-1 include systemic infection, persistent infection, and horizontal transmission. These features allow DuCV-1 to circulate more easily in farms and increase the susceptibility of ducks to other diseases.

Usefulness of Vessel Wall MR Imaging for Follow-Up after Stent-Assisted Coil Embolization of Intracranial Aneurysms

BACKGROUND AND PURPOSE

Follow-up with MRA for intracranial aneurysms after stent-assisted coiling is complicated by imaging artifacts. We evaluated the usefulness of an alternative method: vessel wall MR imaging.

MATERIALS AND METHODS

We conducted a single-center, retrospective review of medical records of 47 patients who underwent 3D TOF-MRA, vessel wall MRI, and DSA after stent-assisted coiling between March 2016 and January 2018. We evaluated the mean value of the signal intensity in the stented artery and the contralateral normal artery on vessel wall MRI. The quality of visualization was further compared between TOF-MRA and vessel wall MRI. Furthermore, we evaluated the diagnostic accuracy and concordance rate of TOF-MRA and vessel wall MRI for assessing the patency of the stented parent artery. DSA was used as a reference test.

RESULTS

The mean signal intensities of the stented and normal arteries on vessel wall MRI were not significantly different (P = .133). The mean scores for the visualization of the stented parent artery on vessel wall MRI were significantly superior to those of TOF-MRA images (P < .001). Vessel wall MRI reached an excellent positive predictive value (100%). However, TOF-MRA had a poor positive predictive value (11%; 95% CI, 9%-12%). The likelihood ratios of vessel wall MRI and TOF-MRA were 27.36 (P < .001) and 2.98 (P = .225), respectively. The concordance rate of vessel wall MRI and TOF-MRA with DSA for evaluating the state of the stented artery was 100% (κ = 1) and 28% (κ = 0.038), respectively.

CONCLUSIONS

Vessel wall MRI may be useful in evaluating the patency of stented arteries after stent-assisted coil embolization for intracranial aneurysms.

Globular adiponectin acts as a melanogenic signal in human epidermal melanocytes

BACKGROUND

Adiponectin is an adipocyte-derived cytokine that circulates as a full-length protein and a fragment containing the globular domain of adiponectin (gAd). A recent study has reported the antimelanogenic effects of full-length adiponectin.

OBJECTIVES

To examine the involvement of gAd in melanogenesis and its mechanisms of action.

METHODS

The effects of gAd on melanogenesis and its mechanisms of action were investigated in human epidermal melanocytes and reconstructed epidermis, including melanin content, cellular tyrosinase activity, cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) activity, expression and phosphorylation of signalling molecules.

RESULTS

Exogenous gAd increased melanin content, and the mRNA levels of microphthalmia-associated transcription factor (MITF) and its downstream genes TRP1, but not TRP2, were increased by gAd. However, cAMP production and PKA activity were not affected by gAd. Moreover, attempts to elucidate the underlying mechanism behind the gAd-mediated effect revealed that gAd could regulate melanogenesis by upregulating MITF through phosphorylation of the cAMP response element-binding protein (CREB). In addition, upregulation of MITF was mediated by activation of adenosine monophosphate-activated protein kinase (AMPK)-p38 mitogen-activated protein kinase (MAPK) signalling. Taken together, these findings indicate that promotion of melanogenesis by gAd occurs through increased expression of MITF, which is mediated by activation of the AMPK-p38 MAPK-CREB pathway.

CONCLUSIONS

These findings suggest that gAd contributes to epidermal homeostasis via its effect on melanocyte biology, and products of adipose tissue could affect epidermal biology.

[Eperythrozoonosis complicated with hemophagocytic syndrome: report of four cases and review of literature]

Objective: To analyze the clinical characteristics of eperythrozoonosis complicated with hemophagocytic syndrome (HPS) in 4 children. Methods: Four patients diagnosed with eperythrozoonosis complicated with HPS in the Children's Hospital Affiliated Capital Institute of Pediatrics during the period from June 2014 to July 2016 were enrolled. The clinical manifestations, laboratory examination data and therapeutic strategies were analyzed. A literature search (search terms included 'eperythrozoonosis' and 'hemophagocytic syndrome') was conducted using CNKI, Wanfang database, Chinese biomedical literature database and PubMed to include recently published studies (searched from the database establishment to January 2017). Results: Four patients were included in the study. One was boy and the other three were girls. The age range of the 4 patients was between 9 months and 17 years (9 months, 2 years and 17 years, 11 months respectively). All the patients presented with recurrent high fever. During the course of fever, 3 patients presented with rash, and 2 patients presented with joint pain and swelling, which mimicked systemic juvenile idiopathic arthritis. Only 1 patient had the contact history of infectious disease. All patients had normal or decreased white blood cell count ((0.80-13.12)×10⁹/L), suffered from varied degrees of anemia and showed the increased C reactive protein (13.0-84.7 mg/L) anderythrocyte sedimentation rate (13-72 mm/1 h). Examination of peripheral blood smears confirmed eperythrozoonosis. After fever continued about 1 month, all the 4 patients rapidly progressed. Among the 4 patients, 1 patient died for giving up further therapy, and the other 3 patients completely recovered after treatment, including azithromycin for the treatment of eperythrozoonosis, and high-dose intravenous methylprednisolone pulse therapy and human immunoglobulin for the treatment of HPS. For the disease not satisfactory, the hemophagocytic lymphohistiocytosis-2004 (HLH-2004) protocol is given. After the hospitalization of 1 to 2 months, the conditions improved and the children were discharged from hospital. Three patients were followed up for 8 months to 2 years, and their conditions were stable. In the PubMed database, no report was found. Nine cases of children with eperythrozoonosis were found in CNKI, Wanfang database and Chinese biomedical literature database, and 1 case was complicated with HPS. These findings, taken together our report, provided the data of 5 children with eperythrozoonosis complicated with HPS (4 cases were younger than 2 years old). A patient had contact history of infectious disease. Five patientss showed fever of unknown origin. All the patients had severe eperythrozoonosis, and 2 cases at younger age died. Conclusions: Children with eperythrozoonosis often present with the protracted fever of unknown origin, and clinical manifestations mimic those of juvenile idiopathic arthritis (systemic type). The patients with eperythrozoonosis of mild-to-moderate disease severity may have a good prognosis. Children with severe eperythrozoonosis, especially those HPS cases with early onset before 2 years old, may have high risk of mortality. Once the patient's condition aggravates in the course of fever, HPS should be highly suspected. For the patients with eperythrozoonosis complicated with HPS, early diagnosis and the combination of anti-infection with the treatment of HPS are crucial for a good prognosis. For the treatment of HPS, HLH-2004 protocol is recommended.

[Tocilizumab for refractory systemic juvenile idiopathic arthritis]

Objective: To evaluate the efficacy and side effects of tocilizumab for the treatment of systemic juvenile idiopathic arthritis. Method: In this prospective self case-control study, the children diagnosed with refractory systemic juvenile idiopathic arthritis admitted to Department of Rheumatism and Immunology of Children's Hospital Affiliated to Capital Institute of Pediatrics from December 2013 to June 2016 were enrolled and information before and after treatment of tocilizumab was analyzed. The tocilizumab was introvenously guttae in a dose of 8-12 mg/kg every 2 weeks. Complete blood count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were tested before and after the application of tocilizumab. Detailed clinical manifestations were recorded. All results were analyzed by χ(2) test and t test. Result: Forty patients with a median age of (6.6±3.7) years were enrolled, including 15 males and 25 females. All of the patients presented with fever and 38 patients got normal temperature 24-48 hours after treatment with tocilizumab. Symptoms disappeared in 13 and improved in 4 patients after treatment among the 17 patients who presented with arthritis. Within the 10 patients who manifested with rashes, 9 patients' rashes disappeared without relapse accompanied by the normalization of temperature after the treatment of tocilizumab. One patient got normal temperature but intermittently emerged rashes after symptoms of arthritis improved. In the 40 patients, 38 well tolerated tocilizumab while 2 showed rashes and chill which disappeared shortly after antianaphylaxis treatment. No severe treatment-related infection was found in any patients. According to the study, the white blood cell counts(×10(9)/L), CRP(mg/L) and ESR(mm/1h) tested 2 weeks after the treatment with tocilizumab were significantly lower than that before treatment(12.1±1.2 vs. 16.5±1.8, 47±8 vs. 67±9, 21±5 vs. 57±6, t=2.75, 3.98, 5.22, P=0.009, 0, 0, respectively). No significant changes were found in concentration of IL-6 and TNF-α (65(207) vs. 45(137) ng/L, and 14(6) vs. 17(19)ng/L, Z=-1.247 and-1.285, P=0.212 and 0.199 respectively). Conclusion: Tocilizumab is a treatment with good efficacy and safety for refractory systemic juvenile idiopathic arthritis. Adverse effects would be found in some patients.

[The effects of closure to live poultry markets on Avian influenza A (H7N9) epidemics in China]

Since March 2013, China had experienced five seasonal epidemics related to Avian influenza A (H7N9). An unprecedented outbreak of H7N9 epidemic started from September 2016, with 730 cases reported till June 30(th) 2017, in mainland China that caused profound influences on both social development and health of the people. As an emerging infectious disease, information on pathogenic characteristics, transmission patterns and other epidemiological features of H7N9 virus somehow remained unclear. Data from previous studies suggested that the live poultry market (LPM) seemed to have served as main places where H7N9 virus got originated, mutated, spread and thus infected the human beings. Hence, closure of LPMs was suggested a major measure to control and prevent H7N9 epidemics in China. However, the effectiveness of different ways of LPM closures on H7N9 epidemics had been controversial. This study systemically summarized the effects of different ways of LPM closures on H7N epidemics from previous studies, aiming to provide references for developing a better program on H7N9 control and prevention in the country.

Comparison of Validity of Mapping between Drug Indications and ICD-10

Background: Mapping of drug indications to ICD-10 was undertaken in Korea by a public and a private institution for their own purposes. A different mapping approach was used by each institution, which presented a good opportunity to compare the validity of the two approaches.

Objectives: This study was undertaken to compare the validity of a direct mapping approach and an indirect terminology based mapping approach of drug indications against the gold standard drawn from the results of the two mapping processes.

Methods: Three hundred and seventy-five cardiovascular reference drugs were selected from all listed cardiovascular drugs for the study. In the direct approach, two experienced nurse coders mapped the free text indications directly to ICD-10. In the indirect terminology based approach, the indications were extracted and coded in the Korean Standard Terminology of Medicine. These terminology coded indications were then manually mapped to ICD-10. The results of the two approaches were compared to the gold standard. A kappa statistic was calculated to see the compatibility of both mapping approaches. Recall, precision and F1 score of each mapping approach were calculated and analyzed using a paired t-test.

Results: The mean number of indications for the study drugs was 5.42. The mean number of ICD-10 codes that matched in direct approach was 46.32 and that of indirect terminology based approach was 56.94. The agreement of the mapping results between the two approaches were poor (kappa = 0.19). The indirect terminology based approach showed higher recall (86.78%) than direct approach (p < 0.001). However, there was no difference in precision and F1 score between the two approaches.

Conclusions: Considering no differences in the F1 scores, both approaches may be used in practice for mapping drug indications to ICD-10. However, in terms of consistency, time and manpower, better results are expected from the indirect terminology based approach.

Analysis on clinical characteristics and drug resistance of Candida parapsilosis bloodstream infections in West China Hospital, China, from 2012 to 2015

OBJECTIVE OF THE STUDY

Candida parapsilosis has emerged as an important cause of bloodstream infections (BSI) in the health care setting. We aimed to describe the clinical characteristics and drug resistance of C. parapsilosis BSI in West China Hospital of Sichuan University in China and provide the basis for prevention and treatment of this disease.

PATIENTS

We retrospectively collected and analyzed patients presented in our hospital reported with C. parapsilosis BSI from January 2012 to January 2015.

MATERIALS AND METHODS

Data regarding age, gender, the department distribution, the potential clinical risk factors and the result of clinical treatment and prognosis were retrospectively evaluated. As to the antifungal drugs susceptibility testing, we used Etest method for determining the minimum inhibitory concentrations (MICs) of amphotericin B, fluconazole, voriconazole, caspofungin and flucytosine for all the clinical isolates of C. parapsilosis. Standard quality strains were used as the controls.

RESULTS

Most of the patients with C. parapsilosis BSI were over 60-year-old (37.5%) or within 10years old (28.13%). Among patients, 78.13% came from an intensive care unit or had undergone surgery in the past several months. The major risk factors associated with an increased risk of infection included the use of broad-spectrum antibacterial drugs and deep vein indwelling. The overall mortality of patients with C. parapsilosis BSI was 31.25%. The drug sensitivity tests revealed that all isolates were sensitive to amphotericin B and flucytosine. Two and 1 isolates were found susceptible to fluconazole and voriconazole in a dose-dependent manner, respectively. Only 1 isolate was resistant to fluconazole. 4 isolates (12.5%) were medium sensitive to caspofungin, but no one showed drug resistance.

CONCLUSION

In summary, elders and newborns were more vulnerable to C. parapsilosis infections. C. parapsilosis was found frequently as pathogens leading to BSI in patients admitted to ICU and departments of surgery and often causing a high mortality rate. C. parapsilosis rarely showed drug resistance at present, so common antifungal drugs could be used for treatment. Recommendations for using of antifungal drugs focused on paying close attention to possible drug resistance trend.

Application of chitosan microparticles for mitigation of Salmonella in agricultural water

AIM

The activity of chitosan microparticles (CM) was examined using a matrix of conditions in order to assess the efficacy of CM as a mitigation against various strains of Salmonella enterica in agricultural water.

METHODS AND RESULTS

Different concentrations of CM (0, 0·01, 0·1, 0·2, 0·3% w/v) were examined for antimicrobial activity against log vs stationary phase cells of Salmonella and at different conditions of temperature, salinity and pH. Results showed greatest activity with 0·3% CM at pH 7, 25-37°C without additional of salt. Significant reductions in Salmonella levels were also achieved in natural pond water, although decreases were reduced compared to sterile water. All serotypes were sensitive to CM, with minimal inhibitory concentrations ranging from 0·0031 to 0·0250% w/v. Phylogenic analysis of Javiana strains showed increased resistance appeared in multiple genetic lineages.

CONCLUSION

Conditions demonstrating greatest CM activity were compatible with agricultural practices. Although sensitivity to CM varied among Salmonella strains, all strains were sensitive under conditions examined in this study.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research indicated that CM, a natural compound with minimal environmental impact, could be an effective alternative for mitigating Salmonella in agricultural water applications.

miR-33a inhibits cell proliferation and invasion by targeting CAND1 in lung cancer

BACKGROUND

Lung cancer continues to be one of the top five causes of cancer-related mortality. This study aims to identify down- and upregulated miRNAs and mRNA which can be used as potential biomarkers and/or therapeutic targets for lung cancer.

METHODS

Integrated analysis of differential expression profiles of miRNA and mRNA in lung cancer was performed by searching Gene Expression Omnibus datasets. Based on miRNA expression profiles, direct mRNA targets of miRNAs with experimental support were identified through miRTarBase. The levels of representative miRNAs and mRNAs were confirmed through qualitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR).

RESULTS

The miR-33a was decreased in non-small cell lung cancer (NSCLC) tissues compared with the para-carcinoma tissues, whereas its target mRNA of cullin-associated NEDD8-dissociated protein 1 (CAND1) was increased in NSCLC tissues. Further research has shown that miR-33a can inhibit lung cancer cell proliferation, cell cycle progression, and migration by targeting CAND1. Moreover, the CAND1 knockout lung cancer cells showed similar results as cells transfected with miR-33a mimic.

CONCLUSIONS

These results suggested that the data mining based on online databases was an effective method in finding novel target in cancer research, and the miR-33a and CAND1 played an important role in lung cancer proliferation and cell migration.

Soft nanostructured films for directing the assembly of functional materials

Lipids are a class of biological small molecules with hydrophilic and hydrophobic constituents forming the structural membranes in cells. Over the past century an extensive understanding of lipid biology and biophysics has been developed illuminating lipids as an intricate, highly tunable, and hierarchical soft-matter system. In addition to serving as cell membrane models, lipids have been investigated as microphase separated structures in aqueous solutions. In terms of applications lipids have been realized as powerful structural motifs for the encapsulation and cellular delivery of genetic material. More recently, lipids have also revealed promise as thin film materials, exhibiting long-range periodic nano-scale order and tunable orientation. In this review we summarize the pertinent understanding of lipid nanostructure development in bulk aqueous systems followed by the current and potential perturbations to these results induced by introduction of a substrate. These effects are punctuated by a summary of our published results in the field of lipid thin films with added nucleic acids and key results introducing hard materials into lipid nanostructured substrates.

Resistance trends among clinical isolates in China reported from CHINET surveillance of bacterial resistance, 2005-2014

With the aim of gathering temporal trends on bacterial epidemiology and resistance from multiple laboratories in China, the CHINET surveillance system was organized in 2005. Antimicrobial susceptibility testing was carried out according to a unified protocol using the Kirby-Bauer method or automated systems. Results were analyzed according to Clinical and Laboratory Standards Institute (CLSI) 2014 definitions. Between 2005 and 2014, the number of bacterial isolates ranged between 22,774 and 84,572 annually. Rates of extended-spectrum β-lactamase production among Escherichia coli isolates were stable, between 51.7 and 55.8%. Resistance of E. coli and Klebsiella pneumoniae to amikacin, ciprofloxacin, piperacillin/tazobactam and cefoperazone/sulbactam decreased with time. Carbapenem resistance among K. pneumoniae isolates increased from 2.4 to 13.4%. Resistance of Pseudomonas aeruginosa strains against all of antimicrobial agents tested including imipenem and meropenem decreased with time. On the contrary, resistance of Acinetobacter baumannii strains to carbapenems increased from 31 to 66.7%. A marked decrease of methicillin resistance from 69% in 2005 to 44.6% in 2014 was observed for Staphylococcus aureus. Carbapenem resistance rates in K. pneumoniae and A. baumannii in China are high. Our results indicate the importance of bacterial surveillance studies.

[Role of magnetic resonance imaging in the diagnosis of juvenile dermato-myositis and polymyositis in Chinese children]

Objective: To evaluate the utility of magnetic resonance imaging (MRI) in diagnosis of juvenile dermatomyositis and polymyositis (JDM-PM) in children. Method: Fifty-four patients with JDM-PM in the active stage were enrolled in the study group. Twelve patients with benign acute childhood myositis and forty patients with juvenile idiopathic arthritis (JIA) complicated with myositis were enrolled as controls. MRI imaging of thighs was performed in all patients, fast spin echo T1WI, T2WI, and STIR were obtained in all patients.Muscle biopsy was performed in 41/54 patients with JDM-PM. We compared the value of MRI in diagnosis of JDM-PM with muscle biopsy, electromyography and serum aspartate transaminase (AST), alanine transaminase (ALT), creatine kinase (CK), isoenzyme of creatine kinase (CKMB), lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH) levels. Continuous normally distributed variables were reported as means and continuous non-normally distributed variables as median. Chi-square test and Fisher exact test were used to test differences between MRI and other categorical variables. Result: A total of 54 patients were included. Twenty-seven patients were male and the others were female. Average age of the patients was (7.1±3.5) years (2-13 years); 45(83%) paitests were JDM cases and 9(17%) patients had JPM. All patients had MRI examination. Of the 54 patients, 53 had multiple myositis; 10 out of 50 (19%) patients received second MRI after treatment, 6 out of 10 patients had normal findings, 4 patients showed obviously improved images; 41 out of 54 patients underwent muscle biopsy; 22 out of 41 patients had inflammatory cells infiltration and muscle fiber degeneration. The results of the muscle enzyme tests are as follows: 27 (50%) patients had elevated AST, 24 (44%) patients had elevated ALT, 22 (41%) patients had elevated CK, 18(33%) patients had elevated CKMB, and LDH rose in 30 (56%) patients, HBDH rose in 28(52%) patients. These results suggested that muscle MRI was more sensitive than muscle biopsy and muscle enzyme tests in diagnosis of JDM-PM. Conclusion: Patients with JDM-PM showed diffuse patchy hyperintense signals on T2WI of their thighs. MRI may be a sensitive, reliable, and noninvasive tool for clinical diagnosis and theraputic evaluation of JDM-PM.