[Temporal trend of antibiotic use among primary school children in Shanghai, 2017-2020].

To investigate the temporal trend of antibiotic use among children in Shanghai from 2017 to 2020. The stratified cluster sampling method was used to establish a dynamic cohort of healthy children based on primary schools in Changning District, Shanghai. In the cohort, there were 282 children from 2017, 287 children from 2018, 294 from 2019 and 301 from 2020. A total of 700 children aged 7-11 years were included in the study. The basic information and antibiotic use of children were investigated by questionnaire every year, and their height and weight were measured at the same time. Chi-square test was used to analyze the difference of antibiotic use rate in each year and generalized estimation equation was used to analyze the temporal trend of antibiotic use. The results showed that the use rates of all antibiotics, cephalosporins, azithromycin and other antibiotics (including penicillin, lincomycin, quinolones, etc.) of children between 2017 and 2020 were 15.6%, 10.5%, 2.7%, and 2.4%, respectively. In 2017, 2018, 2019, and 2020, there were significant differences for the use rates of total antibiotics and other antibiotics in children (P=0.033, P=0.040), and there were no significant differences for the use rates of cephalosporins and azithromycin (P=0.274, P=0.455). After adjusting for children's basic characteristics, the generalized estimation equation showed that the annual use rate of all antibiotics, cephalosporins, and other antibiotics decreased over time.

Prevalence of TTN mutations in patients with dilated cardiomyopathy : A meta-analysis.

A meta-analysis was performed to assess the prevalence of TTN mutations in patients with dilated cardiomyopathy (DCM). Prevalence point estimates and 95% confidence intervals were computed using the logit transformation formula. The prevalence of TTN mutations in patient with DCM, familial dilated cardiomyopathy (FDCM), and sporadic dilated cardiomyopathy (SDCM) was 0.17 (95% CI: 0.14-0.19), 0.23 (95% CI: 0.20-0.26), and 0.16 (95% CI: 0.12-0.21), respectively. No individual study had a marked influence on the pooled prevalence in the meta-analysis. Meta-regression analysis between the logit event for prevalence and sample size explained 32% of between-study variance (p < 0.05). Cumulative meta-analysis confirmed the influence of sample size on the reported prevalence among the different studies. In conclusion, the present analysis suggests that TTN mutations are familial in DCM patients. More attention should be paid to TTN mutations in clinical examinations.

Intratumoral IL17-producing cells infiltration correlate with antitumor immune contexture and improved response to adjuvant chemotherapy in gastric cancer.

BACKGROUND: Tumor IL17-producing (IL17A+) cells infiltration has different prognostic values among various cancers. The objective of this study was to assess the effect of IL17A+ cells in gastric cancer. PATIENTS AND METHODS: The study included two patient cohorts, the Cancer Genome Atlas cohort (TCGA, n = 351) and the Zhongshan Hospital cohort (ZSHC, n = 458). The TCGA and ZSHC were used for mRNA-related and cells infiltration-related analyses, respectively. The roles of IL17A mRNA and IL17A+ cells in overall survival (OS), response to adjuvant chemotherapy (ACT), and immune contexture were evaluated. Another independent cohort was included to identify the correlation between mRNA of IL17A and IL17A+ cells infiltration (the preliminary Zhongshan Hospital cohort, PZSHC, n = 21). RESULTS: The infiltration of IL17A+ cells was positively correlated with the expression of IL17A mRNA (Spearman's ρ = 0.811; P < 0.001). High IL17A mRNA expression and intratumoral IL17A+ cells were correlated with improved OS and remained to be significant after adjusted for confounders. Patients with TNM II/III disease whose tumor present higher intratumoral IL17A+ cells or lower peritumoral IL17A+ cells can benefit more from ACT. Elevated IL17A mRNA expression and increased intratumoral IL17A+ cells infiltration was associated with more antitumor mast cells and nature killer cells infiltration and less pro-tumor M2 macrophages infiltration. High IL17A mRNA expression represented a Th17 cells signature and immune response process and was correlated with increased cytotoxic GZMA, GZMB, IFNG, PRF1, and TNFSF11 expression. CONCLUSIONS: IL17A mRNA expression and intratumoral IL17A+ cells infiltration were correlated with antitumor immune contexture. IL17A+ cells infiltration could be used as an independent prognostic biomarker for OS and predictive biomarker for superior response to ACT, and further prospective validation needs to be conducted.

Risk factors associated with oral and maxillofacial benign tumors: A case-control study.

This study aimed to investigate the risk factors for oral and maxillofacial benign tumors (OMFBTs). A total of 138 patients diagnosed with OMFBTs between September 2010 and September 2015 were retrospectively analyzed. Clinical data including demographic characteristics, smoking and drinking status, dietary habit, oral hygiene and tumor related family history were collected and compared with 134 cases of healthy people who visited the hospital for physical examination during the same time. Logistic regression analysis was performed for multivariable regression analysis. OMFBTs was associated with smoking more than 20 cigarettes per day, accumulated cigarette consumption more than 30, accumulated cigarette package consumption more than 1000, present smoking and drinking, passive smoking before 18 years old, initial smoking age more than 20 years old and alcohol consumption more than 50 g/d (P < 0.05). Consumption of meat, fish, seafood, fruits and vitamin tablets were associated with lower risk of OMFBTs. Non-conditional logistic regression analyses indicated that the independent risk factors of OMFBTs included accumulated cigarette consumption, passive smoking before the age of 18, meat-free, fish-free, fruit-free, vitamin tablets-free, frequency of tooth brushing lower than once a day, not routinely attending oral examination, wearing denture and drinking alcohol (P < 0.05). Smoking and drinking should be discouraged in dental patients. Keeping a good dietary habit and routinely attending oral examination are highly encouraged.

Anodic aluminum oxide-epoxy composite acoustic matching layers for ultrasonic transducer application.

The goal of this work is to demonstrate the application of anodic aluminum oxide (AAO) template as matching layer of ultrasonic transducer. Quarter-wavelength acoustic matching layer is known as a vital component in medical ultrasonic transducers to compensate the acoustic impedance mismatch between piezoelectric element and human body. The AAO matching layer is made of anodic aluminum oxide template filled with epoxy resin, i.e. AAO-epoxy 1-3 composite. Using this composite as the first matching layer, a ∼12MHz ultrasonic transducer based on soft lead zirconate titanate piezoelectric ceramic is fabricated, and pulse-echo measurements show that the transducer exhibits very good performance with broad bandwidth of 68% (-6dB) and two-way insertion loss of -22.7dB. Wire phantom ultrasonic image is also used to evaluate the transducer's performance, and the results confirm the process feasibility and merit of AAO-epoxy composite as a new matching material for ultrasonic transducer application. This matching scheme provides a solution to address the problems existing in the conventional 0-3 composite matching layer and suggests another useful application of AAO template.

Tissue-specific pattern of angiotensin-converting enzyme 2 expression in rat pancreas.

Angiotensin-converting enzyme 2 (ACE2), a carboxypeptidase that is highly homologous to ACE, acts as a negative regulator for the renin-angiotensin system (RAS). Pancreatic RAS is thought to play important endocrine and exocrine roles in hormone secretion. Further exploration of this system is likely to offer new insights into the pathogenesis of pancreatic diseases such as diabetes mellitus. This study investigated the expression of ACE2 in rat pancreatic exocrine and endocrine tissue. Reverse transcription-polymerase chain reaction, immunoblotting and immunohistochemistry showed that ACE2 mRNA and protein were expressed in the pancreas. Immunoelectron microscopy demonstrated that ACE2 was expressed in both endocrine and exocrine pancreatic tissues. In the endocrine tissue, ACE2 was localized on the secretory granules. Double immunofluorescence labelling showed that ACE2 was co-localized with both insulin and somatostatin, while it was rarely co-localized with glucagon and pancreatic polypeptide. These findings suggest that ACE2 might play an important role in glucose homeostasis.

Long-term effects of fertilization on soil organic carbon changes in continuous corn of northeast China: RothC model simulations.

Soil organic C (SOC) content can increase by managing land use practices in which the rates of organic C input exceed those of organic C mineralization. Understanding the changes in SOC content of Black soils (mainly Typic Halpudoll) in northeast China is necessary for sustainable using of soil resources there. We used the RothC model to estimate SOC levels of Black soils under monoculture cropping corn in a long-term fertilization trial at Gongzhuling, Jilin Province, China. The model outputs for the changes in SOC were compared with measured data in this long-term fertilization/manure trial. The sound performance of model in simulating SOC changes suggests that RothC is feasible with Black soils in the temperate climatic region of northeast China. The modeled and measured results indicated that the treatment without fertilizer/farmyard manure (FYM) addition led to a continuous decline in SOC during the study period and N and NPK fertilization were inadequate to maintain the SOC levels in the plow layer (upper 20 cm) unless FYM was added under the current conventional management associated with no above-ground crop residues returning into the soil. Soil organic carbon could follow the same path of decline if the same management practices are maintained. Model results indicate that returning above-ground crop residues to the soil from 2002 to 2022 would increase SOC by 26% for the treatment without fertilization addition, 40% for N treatment, 45% for NPK treatment, and 38% and 46% for N and NPK treatments with FYM addition, compared to the levels in the corresponding treatments in 2002. The simulation results suggest that the RothC model is a feasible tool to assess SOC trend under different management practices, and returning above-ground crop residues into the soil would lead to a remarkable increase in SOC of Black soils in the region.

Significance of local electrostatic interactions in staphylococcal nuclease studied by site-directed mutagenesis.

In this paper, we show that amino acids Glu(73) and Asp(77) of staphylococcal nuclease cooperate unequally with Glu(75) to stabilize its structure located between the C-terminal helix and beta-barrel of the protein. Amino acid substitutions E73G and D77G cause losses of the catalytic efficiency of 24 and 16% and cause thermal stability losses of 22 and 26%, respectively, in comparison with the wild type (WT) protein. However, these changes do not significantly change global and local secondary structures, based on measurements of fluorescence and CD(222 nm). Furthermore, x-ray diffraction analysis of the E75G protein shows that the overall structure of mutant and WT proteins is similar. However, this mutation does cause a loss of essential hydrogen bonding and charge interactions between Glu(75) and Lys(9), Tyr(93), and His(121). In experiments using double point mutations, E73G/D77G, E73G/E75G, and E75G/D77G, significant changes are seen in all mutants in comparison with WT protein as measured by fluorescence and CD spectroscopy. The losses of thermal stability are 47, 59, and 58%, for E73G/D77G, E73G/E75G, and E75G/D77G, respectively. The triple mutant, E73G/E75G/D77G, results in fluorescence intensity and CD(222 nm) close to those of the denatured state and in a thermal stability loss of 65% relative to the WT protein. Based on these results, we propose a model in which significant electrostatic interactions result in the formation of a locally stable structure in staphylococcal nuclease.

[Effects of medium and culture conditions on polysaccharide synthesis by suspension cell culture of Gardenia jasminoides Eills].

The effects of medium and culture condition on polysaccharide synthesis by suspension culture of Gardenia jasminoides Eills were studied. The results show that B5 was the optimum medium, 5-10 days was suitable for subculture periods, and an inoculum of 80 g/L wet cell was better to cell growth and polysaccharide accumulation. For carbon source, it was better to use glucose than sucrose on cell growth, but due to the higher price of glucose, 45 g/L compound carbon source combined sucrose with glucose (1:1) was the optimum. The effect of different kinds of nitrogen source on cell growth and polysaccharide synthesis was not so big, and 40-50 mmol/L nitrogen was optimum, lower concentration of nitrogen source could inhibit the synthesis of polysaccharides. In addition, by controlling the harvest time of the polysaccharide in the suspension culture, the accumulation of yellow pigment could be prevented, which is easier to the polysaccharide purification.

Vesicle size, size distribution, stability, and rheological properties of liposomes coated with water-soluble chitosans of different molecular weights and concentrations.

The objectives of this study were to explore the effects of coating with water-soluble chitosans of different molecular weights and concentrations on vesicle size, size distribution, stability, and apparent viscosity of liposomes. The results indicate that the vesicle size of liposomes coated with different concentrations and different molecular weights of water-soluble chitosans decreased with increasing passes of microfluidizing treatment, then reached a constant value. Liposomes subjected to the same microfluidization treatment were larger for those coated with a higher concentration (of the same molecular weight chitosan) or coated with a lower molecular weight (at the same concentration) of water-soluble chitosans. The average particle size of liposomes coated with different molecular weights of water-soluble chitosans decreased with increasing number of passes of microfluidizing treatment. The apparent viscosity of liposomes coated with water-soluble chitosans decreased after the first pass, then reached a constant value after the third pass of microfluidizing treatment. Apparent viscosities of liposomes subjected to different passes of microfluidization treatment were larger for those coated with a higher concentration or a higher molecular weight of water-soluble chitosans. Liposomes coated with 0.5% of different molecular weights of water-soluble chitosans behaved as pseudoplastic fluids. At the same shear rate, the apparent viscosities of liposomes subjected to more passes of microfluidizing treatment were larger than those subjected to fewer passes of microfluidizing treatment. Liposomes coated with water-soluble chitosans are more stable than those without a coating.

Junceellolides E-G, new briarane diterpenes from the West Pacific Ocean gorgonian Junceella fragilis.

Three new diterpenes, junceellolides E-G (1-3), along with an unnamed known diterpene 4, possessing the briarane carbon skeleton, have been isolated from the gorgonian Junceella fragilis collected in Taiwanese tropical waters. The structures of the new metabolites 1-3 were elucidated by extensive spectral analyses. The six-membered rings in junceellolides E and F (1 and 2) were found to exist in boat conformations. The structure, including the relative configuration of junceellolide E (1) was further confirmed by a single-crystal X-ray analysis.

[Site-directed mutagenesis of melittin gene and its expression in Escherichia coli].

The cDNA encoding promelittin was obtained from the total RNA of bee poison gland by RT-PCR. Moreover, hydroxylamine clearage site was arranged before the melittin sequences by site-directed mutagenesis. The expression vector containing the mutagenic promelittin sequence with partial sequence of beta-galactosidase was constructed. The result of DNA sequence analysis demonstrated that the obtained cDNA sequence include the desired codon and the reading frame of fusion gene was correct. The induced protein was expressed in Escherichia coli.

[Studies on analysis of Belladonna alkaloids by capillary GC and GC-MSD].

A method for analyzing belladonna alkaloids--hyoscyamine, scopolamine, anisodamine and anisodine, by means of capillary GC and GC-MSD was described. The retention data and characteristic ions of the parent and TMS derivatives of these alkaloids are given and will be very useful for identification of unknown alkaloids. The derivatization of different silylation reagents was compared, and the derivatization with MSTFA was found to be better than with BSA and BSTFA. The method has been used for studying biotransformation of these alkaloids in biosynthesis. Analysis of anisodamine and anisodine by CGC and GC-MS has not been found in the literature. In addition, the advantages of TMS derivatization are also discussed.

[Studies on the analysis of stereoisomer of agarofurans by GC and GC-MS].

The method for separation and identification of three pairs of agarofuran epimers (alpha-and beta-dihydroagarofuran, alpha- and beta-baimuxinol, alpha- and beta-baimuxinol methyl ether) by HRGC and HRGC/MSD is described. The proportion of each pair of isomers was determined and the analytical procedure for isomers of sesquiterpenes was established. Thus, the correct synthetic route can be effectively guided and the study of agarofuran synthesis can be greatly accelerated. The method provides a reliable basis for identifying the products. MS data given in Table 2 may be useful for the identification of agarofuran derivatives.

[Studies on the analysis of beta-blocking agents].

A method for the separation and identification of 13 beta-blockers using GC/MS and GC/NPD are described. The TFA and TMS derivatives were prepared by adding TFAA, MSTFA and MBTFA to the standard drugs. The mixture was heated at 65 degrees C for 20 min and chromatographed on FS capillary columns (HP-5). Preliminary results show that the derivatization with MSTFA is better than that with TFAA or MBTFA. There is not much difference between TFAA and MBTFA derivatization. The method is reliable, rapid and simple and may be used to screen these drugs and further applied to the analysis of biological fluids such as plasma and urine.

Study on the doping control method for the detection of narcotic analgesics and beta-blockers.

The analytical method for doping control analysis has been studied. Twenty-nine drugs including eighteen narcotic analgesics, nine beta-blockers, one stimulant and one internal standard were analysed simultaneously by gas chromatograph equipped with a nitrogen-phosphorous detector and gas chromatograph combined with a mass selective detector after derivatization of the drugs.

[Studies on the analysis of anileridine, levorphanol, nalbuphine and ethamivan in urine].

The method for the analysis of anileridine, levorphanol, nalbuphine and ethamivan in urine by means of GC/NPD and GC/MSD is described. TFAA and MSTFA-MBTFA have been used in this procedure for TFA and TMS derivatization. The parent forms and the metabolites of the four drugs can be found by GC/NPD screening and GC/MSD confirmation. The method is reliable, fast and sensitive.

[Studies on chemical constituents of the essential oil of Cyclorhiza waltonii].

Essential oil from the rhizome of Cyclorhiza waltonii was obtained by steam distillation. The chemical components of the oil were examined by means of capillary gas chromatography and gas chromatography-mass selective detector with HP-5 and Carbowax 20M stationary phases. Fifteen constituents of the oil were identified. The content of each component identified was determined by area normalization method. Of these, the content of ten compounds was higher than 2%. They are: alpha-pinene, sabinene, alpha-therpinene, p-cymene, beta-phellandrene, gamma-terpinene, terpinolene, terpineo-4-ol, cis-caryophyllene, duryl aldehyde and isoduryl aldehyde. The oil was found to compose of almost all the types of volatile composition, i.e., not only monoterpenes and sesquiterpenes but also alcohols and aldehydes. Duryl aldehyde and isoduryl aldehyde are not common in volatile oils.