[Exploring the causality between intestinal flora and hyperplastic scars of human based on two-sample Mendelian randomization analysis]

Objective: To investigate the causality between intestinal flora and hypertrophic scars (HS) of human. Methods: This study was a study based on two-sample Mendelian randomization (TSMR) analysis. The data on intestinal flora (n=18 473) and HS (n=208 248) of human were obtained from the genome-wide association study database. Genetically variable genes at five levels (phylum, class, order, family, and genus) of known intestinal flora, i.e., single nucleotide polymorphisms (SNPs), were extracted as instrumental variables for linkage disequilibrium (LD) analysis. Human genotype-phenotype association analysis was performed using PhenoScanner V2 database to exclude SNPs unrelated to HS in intestinal flora and analyze whether the selected SNPs were weak instrumental variables. The causal relationship between intestinal flora SNPs and HS was analyzed through four methods of TSMR analysis, namely inverse variance weighted (IVW), MR-Egger regression, weighted median, and weighted mode. Scatter plots of significant results from the four aforementioned analysis methods were plotted to analyze the correlation between intestinal flora SNPs and HS. Both IVW test and MR-Egger regression test were used to assess the heterogeneity of intestinal flora SNPs, MR-Egger regression test and MR-PRESSO outlier test were used to assess the horizontal multiplicity of intestinal flora SNPs, and leave-one-out sensitivity analysis was used to determine whether HS was caused by a single SNP in the intestinal flora. Reverse TSMR analyses were performed for HS SNPs and genus Intestinimonas or genus Ruminococcus2, respectively, to detect whether there was reverse causality between them. Results: A total of 196 known intestinal flora, belonging to 9 phyla, 16 classes, 20 orders, 32 families, and 119 genera, were obtained, and multiple SNPs were obtained from each flora as instrumental variables. LD analysis showed that the SNPs of the intestinal flora were consistent with the hypothesis that genetic variation was strongly associated with exposure factors, except for rs1000888, rs12566247, and rs994794. Human genotype-phenotype association analysis showed that none of the selected SNPs after LD analysis was excluded and there were no weak instrumental variables. IVW, MR-Egger regression, weighted median, and weighted mode of TSMR analysis showed that both genus Intestinimonas and genus Ruminococcus2 were causally associated with HS. Among them, forest plots of IVW and MR-Egger regression analyses also showed that 16 SNPs (the same SNPs number of this genus below) of genus Intestinimonas and 15 SNPs (the same SNPs number of this genus below) of genus Ruminococcus2 were protective factors for HS. Further, IVW analysis showed that genus Intestinimonas SNPs (with odds ratio of 0.62, 95% confidence interval of 0.41-0.93, P<0.05) and genus Ruminococcus2 SNPs (with odds ratio of 0.62, 95% confidence interval of 0.40-0.97, P<0.05) were negatively correlated with the risk of HS. Scatter plots showed that SNPs of genus Intestinimonas and genus Ruminococcus2 were protective factors of HS. Both IVW test and MR-Egger regression test showed that SNPs of genus Intestinimonas (with Q values of 5.73 and 5.76, respectively, P>0.05) and genus Ruminococcus2 (with Q values of 13.67 and 15.61, respectively, P>0.05) were not heterogeneous. MR-Egger regression test showed that the SNPs of genus Intestinimonas and genus Ruminococcus2 had no horizontal multiplicity (with intercepts of 0.01 and 0.06, respectively, P>0.05); MR-PRESSO outlier test showed that the SNPs of genus Intestinimonas and genus Ruminococcus2 had no horizontal multiplicity (P>0.05). Leave-one-out sensitivity analysis showed that no single intestinal flora SNP drove the occurrence of HS. Reverse TSMR analysis showed no reverse causality between HS SNPs and genus Intestinimonas or genus Ruminococcus2 (with odds ratios of 1.01 and 0.99, respectively, 95% confidence intervals of 0.97-1.06 and 0.96-1.04, respectively, P>0.05). Conclusions: There is a causal relationship between intestinal flora and HS of human, in which genus Intestinimonas and genus Ruminococcus2 have a certain effect on inhibiting HS.

[Clinical features of patients with metastatic pheochromocytoma/paraganglioma]

Objective: To analyze the clinical features of patients with metastatic pheochromocytoma/paraganglioma (PPGL). Methods: A follow-up study. The clinical data of 250 patients with metastatic PPGL treated at Peking Union Medical College Hospital from January 2018 to August 2023 were retrospectively analyzed, including 124 males and 126 females. The clinical features and treatment status of patients with metastatic PPGL were summarized and analyzed. Kaplan-Meier survival curve was used to evaluate patients' prognosis. Results: The age of onset, age of diagnosis, and age of tumor metastasis in patients with metastatic PPGL were (33.1±14.2) years, (35.4±15.2) years, and (40.7±15.3) years, respectively. Metastasis occurred in 26.4%(66/250) of patients at the time of initial diagnosis. Among patients without metastases at the time of initial diagnosis, the time from primary tumor resection to metastasis[M(Q1, Q3)] was 5.0 (3.0, 9.0) years, among which 20.1%(37/184) of patients had metastases more than 10 years after surgery. Most patients showed increased 24-hour urinary norepinephrine and plasma normetanephrine, accounting for 78.2%(176/225) and 78.7%(85/108), respectively. 42.3%(69/163) of patients had increased neuron specific enolase (NSE)levels. Germline mutations were screened in 201 patients, of which 55.2%(111/201) had germline pathogenic mutations. In patients with gene mutations, 76.5%(85/111) had SDHB mutations. 52.0%(130/250) of metastatic PPGL patients had primary sites outside the adrenal gland, with the Ki-67 index of 5% (3%, 8%). There were 85.6%(214/250) patients had multisystem metastasis, with bone metastasis being the most common site of metastasis, accounting for 60.8%(152/250). In terms of treatment, 32.8%(75/229) of patients underwent two treatment regimens and 8.7%(20/229) of patients underwent three treatment regimens. Most patients had a good prognosis, with a 5-year and 10-year survival rate of 88.0% and 84.0%, respectively. However, some patients had rapid disease progression, and as of August 2023, 30 patients died, and the time from diagnosis to death in deceased patients was 2.0 (1.0, 4.0) years. Conclusions: Patients with metastatic PPGL have a high rate of germline mutations, especially those with SDHB mutations. The metastatic PPGL is usually multisystem metastasis with the characteristics of mostly paraganglioma, large lesion diameter and high Ki-67 index.

The environmental and socioeconomic effects of tuberculosis patients in the southwest of China: a population-based study

OBJECTIVE

The objective of this study was to assess the incidence of tuberculosis (TB) and find the risk factors of TB patients with a high burden of TB in socioeconomic level, the high level of TB incidence and the great changes of economic and social factors, explore the possible factors, construct scientific and robust prediction model, and analyse whether the task of stopping TB can be accomplished by the expected global deadline.

STUDY DESIGN

This was an ecological study.

METHODS

Descriptive analysis, spatial and space-time scan, correlation analysis, and regression analysis were carried out, based on cases of TB in Sichuan Province and ecological data from 2006 to 2017, to explore the characters of TB and ecological factors, using the transfer function-noise model to forecast the trend of TB until 2035.

RESULTS

Factors affecting the incidence of TB, increasing per capita green area, reporting status of TB among Tibetans and Yi minorities, comprehensive treatment management, total cost of TB per capita for urban residents, proportion of males with high school education, 20 to 20 h of 24-h accumulated precipitation, reducing HIV at the same time as AIDS deaths, the increase in the proportion of males in junior high school education, and the increase in the number of registered TB cases can reduce the incidence of TB.

CONCLUSIONS

There was concentration mainly on enhanced control of the environment and society measures, helpful in guiding government planning to control TB. Reinforcement is required to reduce the TB of population aged 15-24 and aged 25-64 in socioeconomic level by 2035.

Occupancy of orbitals and the quadrupole collectivity in 45Sc nucleus

In the present work, the Doppler Shift Attenuation method (DSAM) was used to analyze the observed lineshapes of transitions from excited states in ⁴⁵Sc, populated in the reaction ³⁶Ar + ¹²C at a beam energy of 145 MeV. The interpretation and comparison of the experimental results have been performed with large-scale shell model calculations, involving different interactions like: GX1A, GX1J, FPD6, KB3 and ZBM2. KB3 and FPD6 (present work) interactions in the negative parity states, and in positive parity states ZBM2 are most pre-eminent in reproducing the results, due to the large configuration space describing strong collective effects. Furthermore, the present work also looks at the details of the shell model helping in improving the understanding for the occupancy of orbitals. The present investigation suggests the observation of stronger collectivity for positive parity states over negative parity states with predicted enhanced collectivity of states in ⁴⁵Sc nucleus.

Hydrogen sulfide and nitric oxide regulate the adaptation to iron deficiency through affecting Fe homeostasis and thiol redox modification in Glycine max seedlings

Iron (Fe) is a vital microelement required for the growth and development of plants. Hydrogen sulfide (H₂S) and nitric oxide (NO), as messenger molecules, participated in the regulation of plant physiological processes. Here, we studied the interaction effects of H₂S and NO on the adaptation to Fe deficiency in Glycine max L. Physiological, biochemical and molecular approaches were conducted to analyze the role of H₂S and NO in regulating the adaptation to Fe deficiency in soybean. We found that H₂S and NO had obvious rescuing function on the Fe deficiency-induced the plant growth inhibition, which was significantly correlated with the increase in Fe content in the leaves, stems, and roots of soybean. Meanwhile, H⁺-flux, ferric chelate reductase (FCR) activity, and root apoplast Fe content were significantly affected by H₂S and NO. Under Fe deficiency conditions NO and H₂S regulated the expression of genes related to Fe homeostasis. Moreover, photosynthesis (Pn) and photosystem II (PSII) efficiency were enhanced by H₂S and NO, and thiol redox modification was important for regulating the adaptation of Fe deficiency. The aforementioned affirmative influences caused by H₂S and NO were also totally reversed by cPTIO (a NO scavenger). Our results suggested that H₂S might act upstream of NO in response to Fe deficiency by affecting the Fe homeostasis enzyme activities and gene expression, and by promoting Fe accumulation in plant tissues as well as by enhancing thiol redox modification and photosynthesis in soybean plants.

Interactions between hydrogen sulphide and rhizobia modulate the physiological and metabolism process during water deficiency-induced oxidative defense in soybean

Hydrogen sulphide (H₂ S), a new gas signal molecule, participates in the regulation of various abiotic stresses in plants. However, how the tandem working of H₂ S and rhizobia affects the adaptation of soybean to water deficiency is still unclear. In this study, we investigated the adaptation mechanism of H₂ S and rhizobia in soybean to water deficiency. Our results revealed that H₂ S and rhizobia jointly enhanced the leaf chlorophyll content and relative water content in plants, and caused an increase in the biomass of soybean seedlings under water deficiency. Besides, in the absence of water, H₂ S enhanced the biomass by affecting the number of nodules and nitrogenase activity during vegetative growth. The expression of nodulation marker genes including early nodulin 40 (GmENOD40), ERF required for nodulation (GmERN) and nodulation inception genes (GmNIN1a, GmNIN2a and GmNIN2b) were upregulated by H₂ S and rhizobia in the nodules. Moreover, the combined effect of H₂ S and rhizobia was proved to affect the enzyme activities and gene expression level of antioxidants, as well as osmotic protective substance content and related gene expression levels under water deficiency in soybean seedlings. In addition, the metabolomic results suggested that the combined effect of H₂ S and rhizobia remarkably promoted the contents of lipids and lipid-like molecules. Our results indicated that H₂ S and rhizobia synergistically reduced the oxidative damage caused by water deficiency through increasing the accumulation of metabolites and strengthening the plant antioxidant capacity.

Probing ^{93m}Mo Isomer Depletion with an Isomer Beam

The isomer depletion of ^{93m}Mo was recently reported [Chiara et al., Nature (London) 554, 216 (2018)NATUAS0028-083610.1038/nature25483] as the first direct observation of nuclear excitation by electron capture (NEEC). However, the measured excitation probability of 1.0(3)% is far beyond the theoretical expectation. In order to understand the inconsistency between theory and experiment, we produce the ^{93m}Mo nuclei using the ^{12}C(^{86}Kr,5n) reaction at a beam energy of 559 MeV and transport the reaction residues to a detection station far away from the target area employing a secondary beam line. The isomer depletion is expected to occur during the slowdown process of the ions in the stopping material. In such a low γ-ray background environment, the signature of isomer depletion is not observed, and an upper limit of 2×10^{-5} is estimated for the excitation probability. This is consistent with the theoretical expectation. Our findings shed doubt on the previously reported NEEC phenomenon and highlight the necessity and feasibility of further experimental investigations for reexamining the isomer depletion under low γ-ray background.

[Nonalcoholic fatty liver disease and liver transplantation]

The rising prevalence of nonalcoholic fatty liver disease (NAFLD) is now the second largest indication for liver transplantation in Western countries, but viral hepatitis B and end-stage alcohol-related liver disease are still the main indications in China. With the improvement of people's living standards, the prevalence of metabolic syndrome, and the number of NAFLD patients has also gradually increased. At the same time, with the hepatitis B vaccination popularization and the nucleos(t)ide analogues and other drugs uses, it is predicted that NAFLD-related end-stage liver disease may become one of the main indications for liver transplantation in our country in the future. This article reviews the research progress of NAFLD and liver transplantation.

[Study on clinical symptoms and influencing factors of influenza-associated severe acute respiratory illness in children younger than 5 years old in Suzhou of China, 2011-2017]

Objective: To study the influencing factors of influenza-associated severe acute respiratory illness (SARI) in children younger than 5 years of old in Suzhou, and to provide evidence to support the improvement of prevention and control strategies for influenza in children. Methods: We conducted a prospective influenza surveillance for hospitalized SARI and outpatient influenza-like illness (ILI) at Children's Hospital of Soochow University from April 2011 to March 2017. We compared the clinical and other characteristics of influenza-positive patients with SARI to those with ILI to find the differences and to identify influencing factors of influenza-associated SARI, using χ² test and unconditional logistic regression. Results: We found 786 cases of influenza-associated ILI and 413 cases of influenza-associated SARI during the study period. Cough, runny nose, shortness of breath, asthma or wheezing were more common in influenza-associated SARI than in influenza-associated ILI (P<0.01). Univariate and multivariate logistic regression showed that the influencing factors which significantly associated with increased risk of influenza-associated SARI were as follows: younger age (<6 months OR=3.6, 6-23 months aOR=2.5), respiratory infection history within 3 months (aOR=4.5), chronic lung disease history (OR=3.4), fever above 39.0 ℃ (39.0-39.9 ℃ aOR=2.4, ≥40.0 ℃ aOR=6.0), and the presence of A/H1N1 (aOR=2.3), A/H3N2 (aOR=1.9). Conclusion: Children younger than 2 years old, with a history of chronic lung disease, a history of respiratory infection within 3 months, or with a fever peak above 39.0 ℃ should seek medical advice as soon as possible or receive annual influenza vaccination to reduce the incidence of influenza-associated serious outcomes.

[The study on the detection method for mercury in blood with direct mercury analyzer]

Objective: To establish a method for determining mercury in blood with direct mercury analyzer. Methods: After the whole blood sample was extracted by solvent and removed by nitric acid, it was then measured by direct mercury analyzer. Results: After optimizing the conditions of the instrument, the linear range was 0.3-60.0 μg/L and the curve correlation coefficient was higher than 0.999. The lower limit of quantitations was 0.3 μg/L and the minimum quantitative concentration was 3.0 μg/L. The recovery and relative standard deviations (RSD) was 95.2%-97.6% and 1.4%-3.3%. Conclusion: The method is stable, reliable, easy to operate and has high sensitive. It can be used to determine mercury in blood.

[Complexity of Detecting CRISPR/Cas9-Mediated Homologous Recombination in Zebrafish]

Homology-directed (HD) genome modification offers an opportunity to precisely modify the genome. Despite reported successful cases, for many loci, precise genome editing remains challenging and inefficient in vivo. Here we report an effort to precisely knock-in a GFP reporter into gad locus mediated by CRISPR/Cas9 system in the zebrafish Danio rerio. PCR artifact was detected in testing for homologous recombination (HR), but was mitigated by optimizing PCR condition and decreasing the injected targeting plasmid concentration. Under this optimized condition, time course analysis revealed a decline of the HR-positive embryos at embryogenesis progressed. GFP signals also diminished at later developmental stages. The GFP signals were consistent with PCR detection, both of which suggested the loss of targeted insertion events at later stages. Such loss of insertion might be one underlying reason for the inability to obtain germ-line transgenic lines with GFP knocked into the gad locus. Our results suggest that the low HR efficiency associated with CRISPR-mediated knock-in is in part due to loss of insertion after targeted integration into the gad locus.

Hydrogen sulfide and rhizobia synergistically regulate nitrogen (N) assimilation and remobilization during N deficiency-induced senescence in soybean

Hydrogen sulfide (H2 S) is emerging as an important signalling molecule that regulates plant growth and abiotic stress responses. However, the roles of H2 S in symbiotic nitrogen (N) assimilation and remobilization have not been characterized. Therefore, we examined how H2 S influences the soybean (Glycine max)/rhizobia interaction in terms of symbiotic N fixation and mobilization during N deficiency-induced senescence. H2 S enhanced biomass accumulation and delayed leaf senescence through effects on nodule numbers, leaf chlorophyll contents, leaf N resorption efficiency, and the N contents in different tissues. Moreover, grain numbers and yield were regulated by H2 S and rhizobia, together with N accumulation in the organs, and N use efficiency. The synergistic effects of H2 S and rhizobia were also demonstrated by effects on the enzyme activities, protein abundances, and gene expressions associated with N metabolism, and senescence-associated genes (SAGs) expression in soybeans grown under conditions of N deficiency. Taken together, these results show that H2 S and rhizobia accelerate N assimilation and remobilization by regulation of the expression of SAGs during N deficiency-induced senescence. Thus, H2 S enhances the vegetative and reproductive growth of soybean, presumably through interactions with rhizobia under conditions of N deficiency.

[Hospitalization rates for influenza-associated severe acute respiratory illness in children younger than five years old in Suzhou of China, 2016-2018]

We analyzed the influenza surveillance data of Children's Hospital of Suzhou University from 2016 to 2018 and estimated the hospitalization burden of children under 5 years old due to influenza infection in Suzhou. The results showed that the influenza virus positive rate of 1 451 severe acute respiratory infection (SARI) cases in Children's Hospital of Suzhou University was 13.6% (95%CI: 11.8%-15.3%; 197 cases), among which the influenza pandemic intensity in 2017-2018 was relatively high, and A/H1N1 was the main pandemic virus. It was estimated that the hospitalization rate of influenza-related SARI in children under 5 years old in Suzhou was 6.9‰ (95%CI: 6.6‰-7.2‰), among which the hospitalization rate of children aged<6 months was higher, up to 11.4‰ (95%CI: 9.9‰-12.8‰).

New Isotope ^{220}Np: Probing the Robustness of the N=126 Shell Closure in Neptunium

A new short-lived neutron-deficient isotope ^{220}Np was synthesized in the fusion-evaporation reaction ^{185}Re(^{40}Ar,5n)^{220}Np at the gas-filled recoil separator SHANS. Based on the measurement of the correlated α-decay chains, the decay properties of ^{220}Np with E_{α}=10040(18)  keV and T_{1/2}=25_{-7}^{+14}  μs were determined, which are in good agreement with theoretical predictions. From the new experimental results coupled with the recently reported α-decay data of ^{219,223}Np, the α-decay systematics for Np isotopes around N=126 was established, which allows us for the first time to test the robustness of the N=126 shell closure in Z=93 Np isotopes. The results also indicate that, in the region of nuclei with Z≥83, the proton drip line has been reached for all odd-Z isotopes up to Np.

[Performance of matrix assisted laser desorption ionization time of flight biotyper system in clinical bacteria identification]

Objective: To evaluate the performance of MALDI Biotyper system in identification of clinically isolated pathogens so as to provide a new rapid identification method. Methods: Total 21 270 pathogens strains, isolated from the First Affiliated Hospital of Fujian Medical Universityduring Nov. 2015 to Dec. 2016, were identified by VITEK-Ⅱ, API and MALDI Biotyper system, respectively.The isolated strains were confirmed by DNA sequencing. Results: The identification of common bacteria with MALDI Biotyper and phenotypic system is highly consistent (>95% and >90%). Among 43 strains of anaerobic bacteria, MALDI Biotyper could identify 90.7% bacteria to species level and 97.7% bacteria to genus level with the statistical significance(χ(2)=6.76, P<0.01), while phenotypic system only identified 65.1% bacteria to species and 69.8% bacteria to genus. Also, no statistical significance was shown for Trichosporon and Candida(P>0.05). MALDI Biotyper could identify 76% filamentous fungi and all of Actinomycetes, Nocardia, Mycobacterium and Legionella to genus level. Conclusions: MALDI Biotyper is an easy-performed, sensitive method for the identification of clinically isolated pathogens. Additionally, the pretreatment and reference database has the effect on identification.

[Interactions between transforming growth factor beta and signal transducer and activator of transcription 3 in the development of liver fibrosis]

Liver fibrosis is a common pathological response in chronic liver injury. In the pathological process of hepatic injury, signaling pathways associated with hepatic fibrosis, which mediates the repair, proliferation and fibrosis of the liver secrete different cytokines. In these pathways, transforming growth factor beta (TGFβ) and signal transducer and activator of transcription 3 (STAT3) play key roles in the proliferation and activation of hepatic stellate cells (HSCs) and promote epithelial mesenchymal transition. In addition, it is also involved in the process of proliferation and transformation of collagen and extracellular matrix molecules into myofibroblasts. TGFβ and STAT3 molecular-related signaling pathways mediate the loss of epithelial phenotype and gene expression in mature epithelial cells, transforming them into mesenchymal cells, and producing anti-apoptosis to hepatocytes and promoting the proliferation of HSCs. However, the mechanisms by which STAT3 and TGFβ molecules are involved in the development and progression of liver fibrosis are not sound distinct. In this review, we attempt to know the mechanisms and interactions of TGFβ and STAT3 molecules that mediate potential liver fibrosis, and promote their role in promoting HSCs production and epithelial mesenchymal transition.

Correlation of androgen receptor and SRD5A2 gene mutations with pediatric hypospadias in 46, XY DSD children

We performed an exploratory study by analyzing the correlation of 46, XY disorders of sex development (46, XY DSD) with androgen receptor (AR) and steroid 5α-reductase-2 (SRD5A2) gene mutations and a safety analysis of dihydrotestosterone (DHT) gel treatment for pediatric micropenis. We collected samples from 76 pediatric patients with 46, XY DSD and 50 healthy adult men with normal fertility as the control group. The pediatric patients were treated with DHT gel (0.1-0.3 mg/kg/day) for three to six months. The extended penis length, testicular volume, and multiple blood parameters were collected before treatment and one, three, and six months after treatment. Of the 76 cases with 46, XY DSD, 31.58% had hypospadias with micropenis and 6.58% had male pseudohermaphroditism. Through AR gene screening, it was found that 14 patients had AR point mutations and 22 patients had SRD5A2 mutations. After treatment with DHT, the penis length of the patients significantly improved after one, three, and six months of treatment, with longer treatment times resulting in greater improvement. Before treatment with DHT, the average serum DHT value of patients with 46, XY DSD was 24.29 pg/mL. After one, three, and six months of treatment, this value increased to 430.71, 328.9, and 323.6 pg/mL, respectively. We conclude that for pediatric patients who have male hermaphroditism or hypospadias with micropenis, AR and SRD5A2 gene mutation detection should be performed. Local application of DHT gel can promote penis growth effectively without systemic adverse reactions.

Complete mitochondrial genomes reveal phylogeny relationship and evolutionary history of the family Felidae

Many mitochondrial DNA sequences are used to estimate phylogenetic relationships among animal taxa and perform molecular phylogenetic evolution analysis. With the continuous development of sequencing technology, numerous mitochondrial sequences have been released in public databases, especially complete mitochondrial DNA sequences. Using multiple sequences is better than using single sequences for phylogenetic analysis of animals because multiple sequences have sufficient information for evolutionary process reconstruction. Therefore, we performed phylogenetic analyses of 14 species of Felidae based on complete mitochondrial genome sequences, with Canis familiaris as an outgroup, using neighbor joining, maximum likelihood, maximum parsimony, and Bayesian inference methods. The consensus phylogenetic trees supported the monophyly of Felidae, and the family could be divided into 2 subfamilies, Felinae and Pantherinae. The genus Panthera and species tigris were also studied in detail. Meanwhile, the divergence of this family was estimated by phylogenetic analysis using the Bayesian method with a relaxed molecular clock, and the results shown were consistent with previous studies. In summary, the evolution of Felidae was reconstructed by phylogenetic analysis based on mitochondrial genome sequences. The described method may be broadly applicable for phylogenetic analyses of anima taxa.

Purification and characterization of an antimicrobial peptide, insect defensin, from immunized house fly (Diptera: Muscidae)

The house fly, Musca domestica L. (Diptera: Muscidae), is involved in phoretic movement of pathogenic agents, but it has a very efficient defense mechanism against infection. It is believed that antimicrobial peptides play a significant role in the defense system of the house fly. Here, we isolated a peptide from the immunized house fly pupae, measured its molecular mass (3987.6 Da) by matrix-assisted laser desorption ionization/time of flight-mass spectrometry, and determined its amino acid sequence by using the Procise Protein Sequencing System (Applied Biosystems, Foster City, CA). The peptide was confirmed as a member of the insect defensin family. It displayed high activity against gram-positive bacteria but lower activity against gram-negative bacteria and fungi. Reverse transcription-polymerase chain reaction showed that the house fly defensin gene was constitutively expressed in naive pupae and strongly up-regulated after immunization. House fly defensin is an amphiphilic peptide with a structure similar to that of the CSalphabeta scaffold of insect defensin A from the flesh fly, Phormia terraenovae Robineau-Desvoidy. To our knowledge, this is the first isolated and characterized house fly antimicrobial peptide, and our work may provide useful information for developing pharmacologically active antimicrobial agents.

Quantitative trait loci mapping of leaf angle and leaf orientation value in maize (Zea mays L.)

A major limiting factor for high productivity of maize (Zea mays L.) in dense planting is light penetration through the canopy. Plant architecture with a narrower leaf angle (LA) and an optimum leaf orientation value (LOV) is desirable to increase light capture for photosynthesis and production per unit area. However, the genetic control of the plant architecture traits remains poorly understood in maize. In this study, QTL for LA, LOV, and related traits were mapped using a set of 229 F(2:3) families derived from the cross between compact and expanded inbred lines, evaluated in three environments. Twenty-five QTL were detected in total. Three of the QTL explained 37.4% and five of the QTL explained 53.9% of the phenotypic variance for LA and LOV, respectively. Two key genome regions controlling leaf angle and leaf orientation were identified. qLA1 and qLOV1 at nearest marker umc2226 on chromosome 1.02 accounted for 20.4 and 23.2% of the phenotypic variance, respectively; qLA5 and qLOV5 at nearest bnlg1287 on chromosome 5 accounted for 9.7 and 9.8% of the phenotypic variance, respectively. These QTL could provide useful information for marker-assisted selection in improving performance of plant architecture with regard to leaf angle and orientation.

Methionine and selenium yeast supplementation of the maternal diets affects antioxidant activity of breeding eggs

Four hundred fifty 52-wk-old Langshan layer hens (dual-purpose type, an indigenous poultry breed of China) were randomly divided into 9 treatments with 5 replicates in each treatment. Birds were fed corn-soybean diets (0.13 mg of Se/kg) supplemented with 0, 0.30, and 0.60 mg/kg of Se from Se yeast and 3.2, 4.0, and 5.4 g of dl-Met/kg, respectively. Increasing Se yeast supplementation significantly increased Se concentration in the egg yolk (P < 0.01) and the Se concentration of the 3.2 g of Met/kg treatment was higher than those of the 4.0 and 5.4 g of Met/kg treatments. Adding 0.3 mg of Se/kg to the diet significantly increased glutathione peroxidase (GSH-Px) activity in the egg yolk compared with 0 and 0.6 mg of Se/kg (P < 0.01) and increasing Se yeast supplementation significantly increased the GSH-Px activity in the egg albumen (P < 0.01). Increasing Met supplementation significantly decreased the GSH-Px activity in both the yolk and the albumen of the eggs (P < 0.01). Methionine supplemented at 3.2 and 4.0 g/kg significantly increased glutathione concentration in the egg yolk compared with 5.4 g of Met/kg (P < 0.01) and increasing Met supplementation increased the glutathione concentration in the egg albumen. Increasing Met supplementation significantly decreased malondialdehyde concentration in the egg yolk (P < 0.01) and Se supplemented at 0 and 0.6 mg/kg increased the malondialdehyde concentrations in the egg yolk compared with 0.3 mg of Se/kg (P < 0.01). Methionine supplemented at 4.0 and 5.4 g/kg significantly decreased carbonyl concentration compared with 3.2 g of Met/kg. The conclusion was drawn that Se yeast and Met supplementation of the maternal diets could enhance antioxidant activity of breeding eggs.

Effects of disulfide bridges glycoprotein E1 on fusogenic activity of Rubella virus

Rubella virus (RUBV) infects cells via an acid-triggered membrane fusion process. RUBV virions contain two cysteine-rich glycoproteins, E2 and E1. The latter is believed to be involved in the membrane fusion. Using a recombinant plasmid containing RUBV E1 and E2, 11 of total 20 cysteines present in the ectodomain of wild type E1 were mutated to test their role in the fusion via the formation of disulfide bridges. The recombinant plasmids containing mutated E1 (Cys2-Cys20) or wild type (wt) E1 were expressed in BHK-21 cells. Their fusogenic and hemadsorption activities in addition to a potential of cell surface expression of E1 and E2 were assayed. The results showed that the fusogenic activity was lost in all tested mutants, while the hemadsorption activity and cell surface expression potential were affected differently in individual mutants. Since only the Cys5 and Cys8 mutations led to a reduction of both hemadsorption and cell surface expression, we assume that these mutations prevented the formation of the disulfide bridge, what led to a misfolding of E1 and consequently to a failure of recognition of E1 by E2. In conclusion, the disulfide bridges disrupted in all the tested mutants appear essential for the cell fusion, while only the disulfide bridge C(5)-C(8) seems to be crucial for the transport of E1 and E2 in the cell.

Novel method for correction of x-ray fluoroscopic image

X-ray fluoroscopic images have been widely used in orthopedic surgery. Unfortunately, the inherent distortion deteriorates the quality of fluoroscopic image. To avoid the discontinuities of local correction techniques and achieve good accuracy in present global correction method, a novel approach for distortion correction is proposed which allows good image quality in relatively acceptable time by combining both global and local methods, and a new local interpolation method is also proposed. Computer simulation and experimental test on fluoroscopic image have been carried out.

Simultaneous assessment of the intraluminal pressure and transit time of the colon using a telemetry technique

Colonic motility disorders are common conditions. However, our understanding of normal and pathological motor functions of the colon remains limited, mainly due to the technical difficulties in accessing this organ for study. To investigate colonic motility under normal physiological conditions, we have developed a novel monitoring system based on a telemetry technique. The system is capable of prolonged and noninvasive measurement of intraluminal pressure changes and transit time of intra-colonic contents. To test the in vivo performance of the monitoring system, 15 healthy volunteers and 15 patients with functional constipation (FC) participated in this study. A single-use telemetry capsule embedded with sensors was ingested by the subjects. The capsule is capable of transmitting colonic pressure and temperature wirelessly. The time of the telemetry capsule entering the segmental colon was detected by ultrasonic detection of the batteries in capsule. Pressure recordings confirmed in general a circadian behavior of colonic motility, as well as its response to waking and meals. In the FC patients, the contractile response to morning awakening and meal ingestion was significantly lower compared to the controls. The transit time measured using this method agreed with the time calculated from radiopaque markers (r = 0.89, p < 0.05). The clinical study proved both the reliability and the noninvasiveness of the system. This capsule-style manometric system may represent a useful tool for the study of physiology and pathology of colonic motor disorders.

[Expression of regulation protein of glial fibrillary acidic protein gene in hippocampus of epileptic rats induced by kainic acid]

AIM AND METHODS

The DNA binding protein from hippocampus of epileptic rats was investigated by southwestern blot, which regulated the expression of glial fibrillary acidic protein (GFAP) gene. Its expression pattern was also studied.

RESULTS

Southwestern blot showed that there were two specific DNA binding proteins that regulated the expression of GFAP gene, and their molecular weight were 39 kDa and 35.5 kDa, respectively. The expression of the DNA binding proteins was markedly increased in hippocampus of kainic acid (KA) + NS group at 5 d, reached the peak at 3 w, lasted for 3 m observed.

CONCLUSION

The results above suggest that KA may increase the expression of GFAP in hippocampus by upregulating the transcription factor that regulated the expression of GFAP gene, which may participate in the formation of epileptic seizures.

[Protective effect of hepatocyte growth factor on hepatocyte poisoning by carbon tetrachloride and related gene expression in rats]

Hepatocyte growth factor (HGF), as a pleiotropic factor, plays important roles in organ regeneration, organogenesis and morphogenesis, but few reports on protective effect of HGF on injured liver are available. The aim of this work was to investigate protective effects of recombinant human HGF (rhHGF) on intoxicated hepatocytes induced by carbon tetrachloride (CCl4). The results are as follows: (1) rhHGF (5 ng/ml) could significantly increase the viability of hepatocytes intoxicated by CCl4 (15 mmol/L), decrease the leakage of intracellular alanine transaminase (ALT) and potassium ions into the culture medium; (2) the combination of rhHGF (5 ng/ml) and epidermal growth factor (EGF) (50 ng/ml) could increase the viability further, decrease the leakage of intracellular ALT and potassium ions of hepatocytes; (3) high expression of HGF and its receptor/c-met gene in regenerating liver after partial hepatectomy and CCl4 (50%, 2.5 ml/kg bw) poisoning were examined respectively by reverse transcription-polymerase chain reaction in rats. The results showed that rhHGF could protect hepatocytes against CCl4 through preventing intracellular ALT and potassium ion leakage, thus suggesting a synergistic effect of rhHGF and EGF on cytoprotection, and high expression of HGF and its receptor/c-met mRNA in the liver treated with PH and CCl4 poisoning. The present study suggests that the expression of HGF and its receptor gene plays an important role in liver regeneration and repair.

[Effect of scorpion venom on the release of GABA in hippocampus of epileptic rats induced by kainic acid]

In the present study, the effect of scorpion venom (SV) on epileptic susceptibility and its neurochemical mechanisms were investigated. After SV or normal saline (NS) administration for three weeks in epileptic rats, epileptic seizures were much more decreased in kainic acid (KA) + SV group than those of KA + NS group. GABA immunocytochemistry showed that both (gamma-aminobutyric acid immunoreactivity (GABA-IR) density and the number of GABA positive neurons were markedly decreased in the ventral hippocampus, especially in hilus of KA + NS group as compared with NS + NS group. However, in the group treated with SV for three weeks, the number of GABA positive neurons and the density of GABA-IR were greater increased than those of both KA + NS group and the NS + NS group. The number of GABA positive neurons and the density of GABA-IR were unchanged in the dorsal hippocampus of all the four groups. The above results suggest that SV may selectively prevent loss of GABAergic interneurons in the ventral hippocampus of rats susceptible to epileptic seizures and increase the release of GABA as an antiepileptic mechanism.

The changes of AP-1 DNA binding activity and components in hippocampus of seizure-sensitive rat induced by kainate

Seizure-sensitive Fisher 344 rats were prepared 7 d after seizure episodes induced by a single subcutaneous administration of convulsive dose (7.5 mg/kg) of kainic acid. The activator protein-1 (AP-1) DNA binding activity and its components in the hippocampus of such rats were examined by Gel shift, Super-shift and Western blot assay. Gel shift assay showed that the basal level of AP-1 DNA binding activity was significantly higher than that of control rat hippocampus. Super-shift showed that only Fra and Jun D antibodies could super-shift AP-1 complex to a higher position. It suggested that the AP-1 complex was composed of Fra and Jun D in hippocampus of the seizure-sensitive rats. Western blot analysis further confirmed that Jun D proteins contained components of 43, 39 and 28 kDa. When secondary seizure stimulations were given to seizure-sensitive rats, the AP-1 DNA binding activity was attenuated and the components of AP-1 proteins changed transiently. In light of our results and those of literature, it appears that all the mentioned changes may play an important role in induction of long-lasting enhancement in seizure susceptibility.

Photon tunneling in a uniaxial crystal film

A method for studying photon tunneling in uniaxial crystal films is presented. The complex refractive index and the complex angle of refraction of the evanescent wave in a crystal are calculated for the most general case. The reflectance and transmittance resulting from the tunneling effect in crystal films are discussed, and the relations among these coefficients and the optical parameters of crystal are found. These relations provide a theoretical basis for characterizing crystal films by means of photon tunneling.

Kainic acid-induced sprouting of dynorphin- and enkephalin-containing mossy fibers in the dentate gyrus of the rat hippocampus

This study utilized Timm histochemistry and immunocytochemistry to determine the prolonged effects of kainic acid on the distribution of dynorphin- and enkephalin-containing mossy fibers in the rat dentate gyrus at progressive time points following kainic acid injection. Beginning 1-2 weeks after kainic acid administration, a progressive increase in the distribution and intensity of staining for supragranular zinc, dynorphin and enkephalin was observed in the dentate gyrus. The kainic acid-induced sprouting of mossy fibers containing dynorphin and enkephalin strongly resembles the pattern observed in the dentate gyrus of humans with temporal lobe epilepsy.

[The effects of single administration of kainic acid on cellular signal transmission pathway and susceptibility to seizure]

In this study, Sprague-Dawley (S.D.) rats were pretreated with kainic acid (KA, 10 mg/kg, i. sc.) 72 days before either deep prepyriform cortex (DPC) kindling or injection of the same dose of KA. The results showed that such pretreatment accelerated the process of kindling, and the KA-induced seizures appeared more severe in behaviours. c-Fos-immunoreactivity (c-Fos-ir) was used to demonstrate the neuronal activity in central nervous system during the provocative dose of KA-induced seizure, as comparing with the control which received normal saline of KA 72 days ago. The results indicated that, the transmission pathways in two groups were just the same; but the time courses of c-fos and c-jun expression in KA pretreated group were accelerated asynchronously; and the synthesis of the proenkephalin mRNA in the Ent was apparently up-regulated. It is suggested that, the long-lasting increase in susceptibility to seizure induced by a single administration of KA may be related to the acceleration of the expression of c-fos/jun and the early onset of the expression of proenkephalin mRNA.

[Chronic toxic effects of aluminum on nervous system in rabbits]

Twenty-one male rabbits were administered with alum (aluminum potassium sulfate) for 32 weeks to study the accumulative toxic effects of aluminum in food additives on central nervous system. Results showed aluminum levels in blood and brain tissue of the animals increased significantly with intake of alum (P < 0.01). Blood zinc levels, and activities of superoxide dismutase (SOD) and monoamine oxidase B (MAO-B) correlated negatively with aluminum levels in blood and brain, and SOD activity correlated negatively to accumulative aluminum deposit and positively to lipid oxide level in brain. Pathological examinations showed lesions in gyrus centralis anterior, gyrus hippocampi and spinal cord of the animals got more severely and extensively with aluminum intake and brain aluminum content, with disarrangement of neurofilaments and neurotubule, and deformation of synaptic structures.

Preliminary study on aluminum content of foods and aluminum intake of residents in Tianjin

Aluminum contents of 64 kinds mof foods in Tianjin were determined. The results showed that the aluminum levels in different kinds of foods varied greatly, and most foodstuffs from natural sources (including contamination from food processing) contained less than 10 mg/kg. Aluminum contents were higher in foodstuffs of plant origin, especially dry beans containing large amounts of aluminum naturally. Lower concentration of aluminum seemed to be present in foodstuffs of animal origin. It was estimated that the potential daily intake of aluminum per person from natural dietary sources in Tianjin was about 3.79 mg. This estimated figure of dietary aluminum intake was very close to the measured data from 24 daily diets of college students, which was 4.86 +/- 1.72 mg. Considering all the potential sources of natural aluminum in foods, water and the individual habitual food, it would appear that most residents in Tianjin would consume 3-10 mg aluminum daily from natural dietary sources.

Design and application of a bifocus lens

A method of designing a bifocus lens is presented. The authors explain how to use the ray-tracing formulas that were suggested in a previous paper [Appl. Opt. 31, 7328 (1992)]. The method of calculating physical quantities in formulas and sign rules is also presented. This method can also be applied to the design of other crystal elements. One useful application of a bifocus lens is as a bifocus interference surface profilometer.

General ray-tracing formulas for crystal

I develop a new method of ray tracing that can be used to analyze the refraction or reflection of rays by both uniaxial and biaxial crystals.

Apomorphine induction of AP-1 DNA binding in the rat striatum after dopamine depletion

The expression of AP-1 transcription factors was assessed in the dopamine-depleted rat striatum over a 1 week period of repeated apomorphine injections. A single injection of apomorphine increased the expression of a 35 kDa Fos-related antigen and Jun proteins and their expression continued to increase until day 3 of repeated apomorphine treatment in dopamine-depleted striata. Apomorphine induces AP-1 transcription factors which may be involved in modulating gene expression in the striatum.

A 35 kDa Fos-related antigen is co-localized with substance P and dynorphin in striatal neurons

The rat striatum after dopamine denervation followed by repeated apomorphine treatment was examined for the co-expression of c-fos and Fos-related antigens with dynorphin, substance P and [Met5]enkephalin using Western blot and immunohistochemical techniques. Administration of apomorphine, a dopamine agonist, elevated the level of 35 kDa Fos-related antigen which co-localized with dynorphin and substance P, but not enkephalin, in striatal neurons.

Decreased glutamate release correlates with elevated dynorphin content in the hippocampus of aged rats with spatial learning deficits

The effects of aging on extracellular glutamate and tissue dynorphin content in the hippocampus were examined in Fischer-344 rats. Young adult (4-month-old) and aged (24-month-old) rats were trained to find a hidden platform in the Morris water task. Aged rats were unable to acquire the spatial learning task as rapidly as young controls. Following behavioral testing, an in vivo microdialysis perfusion method was used to determine extracellular glutamate levels in the hippocampus. There was a 25-35% reduction in extracellular glutamate concentration in both dorsal and ventral hippocampus of aged rats compared to young rats, in the absence of any change in tissue glutamate levels. Radioimmunoassay showed an increase in dynorphin A(1-8)-like immunoreactivity [DYN-A(1-8)LI] in both dorsal and ventral hippocampus, but not striatum, of aged rats. Immunocytochemistry indicated that this increase was localized to the dentate granule cells and mossy fibers. Furthermore, among the aged rats the increase in DYN-A(1-8)LI was inversely correlated with the decrease in extracellular glutamate. These results suggest that the disregulation of dynorphin observed in cognitively impaired aged rats is related to reduced excitatory transmission within the hippocampal formation.