Progress in endogenous neural stem cells for neonatal brain injury / 国际儿科学杂志

Neonatal brain injury refers to the pathological damage of brain tissue caused by various factors in the perinatal period.The most common disorders are hypoxic-ischemic encephalopathy, periventricular-intraventricular hemorrhage, and periventricular leukomalacia.After a severe brain injury, the repair and reconstruction of the central nervous system (CNS) is crucial in restoring CNS architecture and function.The studies have shown that neural stem cells (NSC) have the potential for multidirectional differentiation and the ability to maintain self-renewal.Endogenous neural stem cells (eNSC) can proliferate, migrate to the lesion sites and finally differentiate into astrocytes, oligodendrocytes, and neurons, to provide new options for the treatment of neural regeneration.This paper aims to review the recent progress of eNSC in treating neonatal brain injury.

Analysis of clinical features and genetic variant in a neonate with Au-Kline syndrome due to a de novo variant of the HNRNPK gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical phenotype and genetic basis of a neonate with Au-Kline syndrome (AKS).@*METHODS@#Clinical data and result of genetic testing of a neonate with AKS who was admitted to the Affiliated Provincial Children's Hospital of Anhui Medical University in January 2021 were retrospectively analyzed. Relevant literature was searched from the Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure and PubMed databases using key words "Au Kline syndrome", "Au-Kline syndrome", "HNRNPK" and "AKS". The research period was set as from January 1, 2000 to December 31, 2020.@*RESULTS@#The male newborn has manifested feeding difficulties, hypotonia, absence of the upper jaw to the uvula and facial dysmorphism. Trio-whole exome sequencing revealed that he has harbored a frameshift c.478dupA (p.Ile160AsnfsTer7) variant of the HNRNPK gene, which was varified by Sanger sequencing to have a de novo origin. The variant has not been included in the databases. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was rated as pathogenic (PVS1+PS2+PM2_Supporting). Literature retrieval has identified 14 children with AKS and de novo mutations of the HNRNPK gene. Their clinical manifestations have included growth and motor retardation, various degree of mental retardation, facial dysmorphism and a high frequency of congenital heart malformations.@*CONCLUSION@#The AKS in this child may be attributed to the c478dupA frameshifting variant of the HNRNPK gene. Diagnosis of AKS should be suspected for children with mental retardation and multiple congenital malformation syndromes including Kabuki syndrome.

Different strategies of reducing non-viral nucleic acid of meta-virome in plasma: a comparative study / 中国输血杂志

【Objective】 To explore the influence of common methods of reducing non-viral nucleic acid on the abundance of plasma virus group. 【Methods】 Three kinds of library construction, five kinds of centrifugation conditions, two kinds of filters, four kinds of enzymes and four concentrations of chloroform were used to treat plasma samples added quantitatively 2.16 mL of pseudorabies virus(PRV) and 2.16 mL of porcine parvovirus(PPV). A total of 21.6 mL of plasma samples were processed, including 54 samples. Subsequently, nucleic acid was extracted, mitochondrial DNA(mtDNA) and two viruses were quantitated, the library of the next generation sequencing was constructed, Illumina NovaSeq 6000 was used for the next generation sequencing. The sequencing data were compared with Kraken Py 2.0 software, and the species annotation analysis was conducted. The corresponding species classification information of each segment was obtained to analyze the impact of different reducing non-viral nucleic acid methods on the relative abundance of microorganisms and two indicator viruses. 【Results】 After sequencing by Illumina NovaSeq 6000, 306.27 GB raw data and 193.17 GB clean data were obtained, with Q20>90%, Q30>85%, Error Rate of 0.03%, and average GC Content of 45.02%. The DNA library construction process significantly increased the proportion of microbial sequences and the PRV abundance [(91.8±0.5)%](P<0.05); RNA library construction and combined library construction can increase the abundance of Pestivirus, an RNA virus, and the PRV abundance was(17.7±3.3)% and(8.1±1.5)% respectively. The Ct value of mtDNA was increased and the proportion of human sequence decreased to less than(89.5±1)%, while the proportion of microbial sequence increased to (2.4±0.03)% after treatment of five centrifugation conditions(P<0.05); After centrifugation at 4℃, 100 g, 30 min, the PRV abundance was increased to (40.6±6)%, and centrifugation at 4℃, 4 000 g, 45 min reduced the PRV abundance to (4.1±0.01)%(P<0.05). Both of 0.22-μm filter and 0.45-μm filter increased the Ct value of mtDNA to above 25.56±0.13, decreased the proportion of human sequence to less than (86.1±0.6)%, increased the proportion of microbial sequence to (3.1±0.1)% and (3.4±0.2)%, and decreased the PRV abundance to (1.6±0.3)% and (4.1±0.7)%(P<0.05), while there was no statistical difference in the effect on PPV concentration and abundance. DNase Ⅰ and Benzonase increased the Ct value of PPV to 25.65±0.06 and 25.36±0.45, decreased the proportion of human sequence to (81.7±5.6)% and (72.8±6.7)%, and increased the proportion of microbial sequence and PRV abundance to (11.0±4.1)% and (16.1±4.7)%, (55.8±2.3)% and (39.0±8.9)%, respectively(P<0 05); After treatment with RNase A, the Ct value of PRV increased to 25.20±0.11, and the human sequence proportion decreased to (85.4±5.6)%(P<0 05); Lysozyme had no effect on removing non-viral nucleic acid. The chloroform of 1%, 5%, 10% and 20% increased Ct value of PRV and mtDNA to no less than 27.17±0.21 and 25.68±0.04; Only 10% chloroform increased the proportion of microbial sequences to (3.1±1.2)%(P<0.05); The abundance of PRV with 1% and 5% chloroform treatment was increased to (48.7±13.3)% and (42.1±5.5)%(P<0.05), while 10% and 20% chloroform reduced PRV abundance to (1.0±0.5)% and (3.4±2.8)%(P<0.05). There was no statistical difference in the effect of chloroform with four contents on PPV abundance. 【Conclusion】 Centrifugation at 4℃, 5 000 g, 10 min is suitable for increasing the overall abundance of virus, and centrifugation at 4℃, 100 g, 30 min is suitable for increasing the content of virus similar to PRV. 0.45-μm filter, DNase Ⅰ, Benzonase and low concentration chloroform can effectively reduce the proportion of non-viral nucleic acid sequence in plasma to increase the abundance of the indicated virus group. Thus, the enrichment effect of plasma meta-virome is closely related to the nature of the virus, and the appropriate virus enrichment method should be selected according to the research purpose to establish the corresponding enrichment strategy.

Detection of platelet bacteria based on cultomics and metagenomics / 中国输血杂志

【Objective】 To explore the composition of culturable bacteria in platelets through bacterial culturomics and verify the results of culturomics and metagenomics to improve the detection rate of bacteria in platelets. 【Methods】 Platelet samples from 6 healthy people were collected. Eight kinds of culture media were placed in aerobic conditions and 12 kinds of culture media were placed in anaerobic conditions for large-scale culture and isolation of bacteria in platelets. The isolated single colony was identified by 16S rRNA gene sequencing. The bacterial abundance of healthy human platelet microbiome was analyzed by metagenomic sequencing, and the cultivable bacterial species in platelets was confirmed based on metagenomic and culturomics results. 【Results】 A total of 90 strains of bacteria belonging to 3 phylums, 5 classes, 5 orders, 7 families, 9 genus and 23 species were isolated from 6 platelet samples by culturomics. Among them, the strains with more monoclonal clones at the species level were Brevundimonas aurantiaca (16.7%), Bacillus sp. Y1 (15.6%), Cutibacterium acnes (14.4%) and Brevibacillus brevis (13.3%). The platelet samples sequenced by mNGS showed that the abundance values of Proteobacteria, Firmicutes and Actinobacteria were high. The bacteria detected by both culturomics and metagenomic sequencing methods were as follows: Firmicutes: Bacillus sp. Y1, B. thuringiensis, B. cereus, B. mobilis, B. velezensis, Staphylococcus epidermidis, and Brevibacillus brevis; Actinobacteria: Cutibacterium acnes; Proteobacteria: Escherichia coli and Delftia tsuruhatensis. 【Conclusion】 The mutual validation of culturomics and metagenomics has identified some bacteria, proving that bacteria exist in platelets.

Clinical characteristics and genetic analysis of a neonate with Smith-Magenis syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genetic etiology for a neonate with Smith-Magenis syndrome (SMS).@*METHODS@#Copy number variation sequencing (CNV-seq) was applied to the neonate and his parents, and the genotype-phenotype correlation was analyzed.@*RESULTS@#On the second day after birth, the neonate had presented with pathological jaundice and immunodeficiency. Cranial MRI revealed ventricular enlargement and enlargement of cisterna magna. At 3 months, the infant has presented with square face, prominent forehead, deep-set eyes, hypertelorism, palpebral fissure upward and button noses. Genetic testing showed that he had carried a 2.9 Mb deletion in 17p11.2 region, seq[GRCh37] del(17)(p11.2)(chr17:16 836 379-19 880 992). The same deletion was not found in either parent.@*CONCLUSION@#SMS is mostly diagnosed in child and adulthood, but rarely in neonates. For neonates with SMS, the neurological and behavioral abnormalities have not been shown, but pathological jaundice, CNS abnormalities and immune deficiency may be the characteristics, which require attention of neonatal physicians.

Mechanisms of ferroptosis in microglial cell line BV-2 cells after lead acetate exposure / 环境与职业医学

Background Lead exposure induces microglial cell death, of which the mechanism is unclear. Ferroptosis is a new death form and its role in microglia death has not been reported. Objective To investigate the role of ferroptosis in microglia following lead exposure in order to provide a theoretical basis for the mechanism of lead neurotoxicity. Methods Microglial cell line BV-2 cells were co-cultured with 0, 10, 20 and 40 μmol·L−1 lead acetate for 24 h. The 40 μmol·L−1 lead acetate group with iron chelator (DFO) was named the 40+DFO group. Changes in BV-2 cell morphology after lead exposure were observed under an inverted microscope; tissue iron kit and glutathione kit were used to detect intracellular iron and glutathione (GSH) respectively; flow cytometry was applied to detect lipid reactive oxygen species (lipid ROS) immunofluorescence intensity. Western blotting and qPCR were adopted to detect the expressions of glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), transferrin receptor 1 (TFR-1), divalent metal transporter 1 (DMT1), ferroportin 1 (FPN1) protein and mRNA. Results Compared with the control group, the number of BV-2 cells decreased with increasing doses of lead and the cells showed a large, round amoeboid shape. The intracellular levels of iron of BV-2 cells were (1.08±0.04), (1.29±0.03), and (1.72±0.10) mg·g−1 (calculated by protein, thereafter) in the 10, 20, and 40 μmol·L−1 lead acetate groups, respectively, significantly higher than that in the control group (P<0.05), and the intracellular level of iron in the 40+DFO group, (1.34±0.10) mg·g−1, was lower than that in the 40 μmol·L−1 lead acetate group, (1.72±0.03) mg·g−1 (P<0.05). Compared with the control group, the TFR-1 and DMT1 protein and mRNA expressions were increased in BV-2 cells in the 10, 20, 40 μmol·L−1 lead acetate groups (P<0.05), especially in the 40 μmol·L−1 lead acetate group; the FPN1 protein expression did not change significantly, but the FPN1 mRNA expressions in BV-2 cells in the 10, 20, 40 μmol·L−1 lead acetate groups were significantly decreased (P<0.05). Compared with the control group, the intracellular GSH level decreased and the lipid ROS content increased in all three lead acetate groups; compared with the 40 μmol·L−1 lead acetate group, the GSH level increased by 12.30% and the lipid ROS content decreased by 13.00% in the 40+DFO group (P<0.05). The expressions of GPX4 protein were reduced to 50.00%, 35.00%, and 17.00% of that of the control group in the 10, 20, and 40 μmol·L−1 lead acetate groups respectively, while the expressions of GPX4 mRNA were also significantly reduced; the expressions of SLC7A11 protein and mRNA in the 20 and 40 μmol·L−1 lead acetate groups were lower than that in the control group, with the most significant decrease in the 40 μmol·L−1 lead acetate group (P<0.05). Conclusion Lead exposure could induce ferroptosis in BV-2 cells, in which iron transport imbalance and oxidative damage might be involved.

Modulation of Beta Oscillations for Implicit Motor Timing in Primate Sensorimotor Cortex during Movement Preparation / 神经科学通报·英文版

Motor timing is an important part of sensorimotor control. Previous studies have shown that beta oscillations embody the process of temporal perception in explicit timing tasks. In contrast, studies focusing on beta oscillations in implicit timing tasks are lacking. In this study, we set up an implicit motor timing task and found a modulation pattern of beta oscillations with temporal perception during movement preparation. We trained two macaques in a repetitive visually-guided reach-to-grasp task with different holding intervals. Spikes and local field potentials were recorded from microelectrode arrays in the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. We analyzed the association between beta oscillations and temporal interval in fixed-duration experiments (500 ms as the Short Group and 1500 ms as the Long Group) and random-duration experiments (500 ms to 1500 ms). The results showed that the peak beta frequencies in both experiments ranged from 15 Hz to 25 Hz. The beta power was higher during the hold period than the movement (reach and grasp) period. Further, in the fixed-duration experiments, the mean power as well as the maximum rate of change of beta power in the first 300 ms were higher in the Short Group than in the Long Group when aligned with the Center Hit event. In contrast, in the random-duration experiments, the corresponding values showed no statistical differences among groups. The peak latency of beta power was shorter in the Short Group than in the Long Group in the fixed-duration experiments, while no consistent modulation pattern was found in the random-duration experiments. These results indicate that beta oscillations can modulate with temporal interval in their power mode. The synchronization period of beta power could reflect the cognitive set maintaining working memory of the temporal structure and attention.

Minimal invasive microscopic tooth preparation in esthetic restoration: a specialist consensus / 国际口腔科学杂志·英文版

By removing a part of the structure, the tooth preparation provides restorative space, bonding surface, and finish line for various restorations on abutment. Preparation technique plays critical role in achieving the optimal result of tooth preparation. With successful application of microscope in endodontics for >30 years, there is a full expectation of microscopic dentistry. However, as relatively little progress has been made in the application of microscopic dentistry in prosthodontics, the following assumptions have been proposed: Is it suitable to choose the tooth preparation technique under the naked eye in the microscopic vision? Is there a more accurate preparation technology intended for the microscope? To obtain long-term stable therapeutic effects, is it much easier to achieve maximum tooth preservation and retinal protection and maintain periodontal tissue and oral function health under microscopic vision? Whether the microscopic prosthodontics is a gimmick or a breakthrough in obtaining an ideal tooth preparation should be resolved in microscopic tooth preparation. This article attempts to illustrate the concept, core elements, and indications of microscopic minimally invasive tooth preparation, physiological basis of dental pulp, periodontium and functions involved in tool preparation, position ergonomics and visual basis for dentists, comparison of tooth preparation by naked eyes and a microscope, and comparison of different designs of microscopic minimally invasive tooth preparation techniques. Furthermore, a clinical protocol for microscopic minimally invasive tooth preparation based on target restorative space guide plate has been put forward and new insights on the quantity and shape of microscopic minimally invasive tooth preparation has been provided.

Study on Synthesis and Identification of Rotundic Acid Esters Derivatives and in vitro Antitumor Activity / 中国药房

OBJECTIVE： To synthesize and identify rotundic acid esters derivatives， and to evaluate in vitro antitumor activity. METHODS： Using rotundic acid as raw material， rotundic acid esters derivatives were synthesized by 28-esterification， 3β and 23-position hydroxyl group combined with acid anhydride. The structure of rotundic acid esters derivatives were identified by HRMS， 1H-NMR， 13C-NMR and physicochemical properties. The in vitro antitumor activities were evaluated by MTT assay against paclitaxel （positive control）， rotundic acid and rotundic acid esters derivatives with human cervical cancer cells HeLa， human malignant melanoma cells A375， human lung adenocarcinoma cells SPC-A1 and human liver cancer cells HepG2 （take IC50 as an indicator）. RESULTS： Totally 6 kinds of rotundic acid esters derivatives were synthesized， i.e. rotundic acid methyl ester（compound 1）， 3， 23-O-di（acetyl） rotundic acid methyl ester（compound 2）， 3， 23-O-di（propionyl） rotundic acid methyl ester（compound 3）， 3， 23-O-di（butyryl） rotundic acid methyl ester（compound 4）， 3， 23-O-di（phthaloyl） rotundic acid methyl ester（compound 5） and 3， 23-O-di（succinyl） rotundic acid methyl ester（compound 6）. Compared with paclitaxel， the antitumor activity of compound 5 and compound 6 to Hela， A375， HepG2 and SPC-A1 was similar to it， and there was no significant difference between them （P＞0.05）； the IC50 of rotuntic acid and other compounds decreased with statistical significance （P＜0.05）. CONCLUSIONS： In the study， 6 kinds of rotundic acid esters derivatives are synthesized and compound 5 and compound 6 have significant antitumor activity in vitro， which can provide reference for further study.

γδ T cells and cancer immunotherapy / 中国医师进修杂志

γδ T cells have been well recognized as a unique cell population that is actively involved in both innate and adoptive immunity of bodies. The features of γδ T cells, such as their major histocompatibility complex independent antigen recognition and their cytotoxic effects to tumor cells, make them as promising candidates used for cancer immunotherapy. There is a strong interest in developing γδ T cell-based immunotherapy for clinical application in treating cancer patients. This review discusses the progress of recent studies related to the γδ T cells and cancer immunotherapy, with an emphasis on the main characteristics of γδ T cells in several types of gynecologic tumors.

Analysis on status and determinants of outpatient service utilization of rural floating population in Beijing at different residence time / 北京大学学报(医学版)

Objective: To study the status and identify the determinants of outpatient service utilization of rural floating population in Beijing who have different accumulated residence time.Methods: The survey data of rural floating population health and health care services in Beijing in 2014 were used, and the migrant population aged 18 years and above were taken as the research object.Whether to use outpatient service within two weeks was taken as dependent variable, gender, age, education level, self-assessment score of socioeconomic status, accumulated residence time in Beijing, health insurance, average household income, suffering from high blood pressure or diabetes as independent variables.Logistic regression model was used to analyze the influencing factors.Results: The average age of the research object was 36.7 years, with mostly secondary education.The average accumulated residence time in Beijing was 8.4 years.The two-week prevalence rate was 10.3%, the two-week visiting rate calculated by person-time was 6.0%.The Logistic regression model suggested that, socioeconomic status, accumulated residence time and suffering from high blood pressure or diabetes were statistically significant determinants of outpatient service utilization.Conclusion: The research object is a younger and less educated population, their health status is better and outpatient service utilization is lower.It is found that people who have longer accumulated residence time in Beijing have lower outpatient service utilization.This is because people with longer residence time have lower age-adjusted two-week prevalence rate.This is also because people with longer residence time have larger proportion of taking continuous measures under doctor's advice.It does not mean people with longer residence time have lower utilization of medical service.The residence time variable plays the role of proxy variable.It can solve the problem of variables' endoge-neity.At the same time, it can reflect the influence to outpatient services utilization of some determinants,which are not included in the model but varies with residence time.

Effects of neonatal hypoglycemia on temperament and neurobehavioral development of preschool children / 医学研究生学报

Objective Neonatal hypoglycemia is a common metabolic disease during neonatal period and a few children with neonatal hypoglycemiamay show a series of neurologic impairment.This study was to explore the neurobehavioral development of preschool children with neonatal hypoglycemia.Methods 37 children with neonatal hypoglycemia in Neonate Department of Anhui Provincal Children's Hospital from March 2009 to May 2013 were investigated by Chinese Preschool-Children Temperament Scale and Conners Symptoms Questionnaire for Parents, together with the information collection of perinatal period, clinical data and family environment.At the same time 50 controls were randomly chosed of the same period.Results The children of hypoglycemia group and control group were mainly with easy temperament and inclined easy temperament.In the nine dimensions of temperament, there was statistical difference in approach-withdraw between two groups (P<0.05).The incidence of behavioral problem in hypoglycemia group is 24%, involving learning problem and psychophysical problem, and there were statistical difference between two groups in this aspect (P<0.05).Conclusion Neonatal hypoglycemia affects the neurobehavioral development of preschool children.Individualized treatment and education intervention should be taken according to the children's temperament and neurobehavioral development.

Screening and Structure Characterization of Acetylcholinesterase Inhibitors from Total Alkaloids of Fibraurea recisa Pierre.by Target Molecule Affinity-Liquid Chromatography-Tandem Mass Spectrometry / 分析化学

A target molecule affinity-ultrafiltration liquid chromatography-electrospray ionization tandem mass spectrometric (LC-ESI-MSn) method was established for rapid screening acetylcholinesterase (AChE) inhibitors from total alkaloids of fibraurea recisa Pierre.A total of 12 potential inhibitors were screened from Fibraurea recisa Pierre.and 6 compounds were identified including palmatine,berberine,jatrorrhizine,palmatrubine,7,8-dihydro-8-hydroxyberberine and groenlandicine.The AChE inhibitory activity of these 6 compounds was validated in vitro.Palmatine showed the strongest inhibitory activity for AChE,which was stronger than that of donepezil hydrochloride,demonstrating the potential of palmatine as anti-Alzheimer's drug.This method is simple,rapid,and accurate for directly screening active ingredients which can inhibit AChE from complex extract of traditional Chinese medicines.

Binocular rivalry estimated objectively under face awareness and fusiform correlation analysis / 军事医学

Objective To study binocular rivalry (BR)objectively and the correlation between fusiform face area (FFA)and visual cortex.Methods Six subjects participated in this study,with one eye presented a normal face expres-sion picture flickered at 8.57 Hz,while the other presented a fearful face flickered at 12 Hz or 15 Hz,respectively.Electro-encephalogram(EEG)was recorded during this process.Steady state visual evoked potential(SSVEP)evoked by two flick-ering rates was analyzed by time-frequency analysis of short time fourier transformation(STFT).The time index of BR was estimated and the correlation coefficient between FFA and visual cortex compared.Results The total average time was (411.6 ±73.8)ms for the left eye and (547.6 ±126.7)ms for the right eye.The switch rate of the two groups was not different,but the left FFA was more sensitive than the right FFA in process of the fearful face.Neither side of FFA had any frequency preference to the flickered fearful face.Conclusion SSVEP can be used as a frequency tag of BR or as a tool to evaluate visual sensation under BR objectively.SSVEP combined with BR can be used in research of neural mechanisms of visual awareness.

Determination of the Main Content and Entrapment Efficiency in the Brucine Nanostructured Lipid Carrier by HPLC / 中国药房

OBJECTIVE:To establish a method for determining the main contents and entrapment efficiency in the bruc-ine nanostructured lipid carrier(NLC). METHODS:HPLC was adopted to determine the main content,sephadex gel filtration meth-od was employed to separate free drug in brucine NLC to determine the entrapment efficiency. The column was Dikma C18 with the mobile phase of mobile phase A(methanol)-mobile phase B [water-acetic acid-triethylamine(230∶2.4∶0.3,V/V/V)](30∶70,V/V)at the flow rate of 1 ml/min,the detection wavelength was 265 nm,volume was 10 μl and temperature was 30 ℃. RESULTS:The linear range of brucine was 4.00-80.00μg/ml(r=0.999 9);RSDs of precision,stability and reproducibility tests were≤1.67%;av-erage recoveries of content determination and sephadex gel filtration method were respectively 99.66%(RSD=0.45%,n=9) and 99.75%(RSD=1.74%,n=9);and the average entrapment efficiency was 69.92%. CONCLUSIONS:The method is simple,re-producible and efficient,and can be used for the determination of main contents and entrapment efficiency in brucine NLC.

Risk factors and prevention of neonatal hypoglycemia / 中国医师进修杂志

Objective To analyze the risk factors and prevention of non-diabetic mother neonatal hypoglycemia,in order to provide evidences for clinical diagnosis and avoid hypoglycemic brain injuries.Methods This was retrospective study using the method of case control.One hundred and eleven cases of non-diabetic mother neonatal hypoglycemia were enrolled in patients group,and 111 controls of normal blood glucose neonate at the same period were enrolled in control group.The risk factors of neonatal hypoglycemia and the results of neural development after hypoglycemia were analyzed.Results The risk factors of neonatal hypoglycemia were low-birth-weight infant(X2=4.066,P=0.044),small for gestation age infant (X2=21.125,P=0.000),congenital heart disease(X2=5.869,P=0.015),day-age≤3 days(X2=6.876,P=0.032),mother with pregnancy-induced hypertension(X2=6.618,P=0.010)or age<25 years old (X2=6.311,P=0.044).Full-term infants might be easier to show up hypogtycemic brain injuries than pre-term infants;the occurrence of hypoglycemic brain injuries correlated with the level of blood glucose and the lasting time of hypoglycemia.Conclusion Monitor blood glucose closely to the infant has risk factors of hypoglycemia,and discover and cure it on time,in order to avoid hypoglycemic brain injuries.

Genetic transformation of Nicotiana tabacum L. by Agrobacterium tumefaciens carrying genes in the melatonin biosynthesis pathway and the enhancement of antioxidative capability in transgenic plants / 生物工程学报

Arylalkylamine N-acetyltransferase (AANAT) and Hydroxyindole O-methyltransferase(HIOMT) are the key regulation enzymes in the melatonin biosynthesis pathway in mammals. The AANAT and HIOMT genes were constructed into a binary plant expression vector YXu55. Using leaf strips as the recipiences, we efficiently transformed tobacco (Nicotiana tabacum) variety qinyan 95 by the Agrobacterium mediated method. After gradient selection with gentamycin, a number of transgenic plants were regenerated. Southern blot and RT-PCR analyses showed that the AANAT-HIOMT genes were integrated into the genome of the transgenic plants and the target genes could express at the level of RNA transcription. By RP-HPLC, we measured the melatonin contents in transgenic plants. The results showed that the melatonin level in YXu55 (containing the gentamycin-resistance gene, the AANAT gene and HIOMT gene) transgenic plants were much higher than those in pZP122 (control containing only the gentamycin-resistance gene) transgenic plants and nontransgenic plants. The content of melatonin in pZP122 transgenic plants was nearly the same as that in nontransgenic plants. Physiological determination of antioxidative characteristics demonstrated that 1) the capacity of total antioxidation, 2) the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and 3) the content of glutathione (GSH) were increased in YXu55 transgenic plants containing the AANAT-HIOMT genes as compared to the control plants (pZP122 or nontransgenic plants). At the same time, malonaldehyde (MDA) content did not appear remarkably difference between transgenic plants and nontransgenic plants. The above mentioned facts indicate enhancement of melatonin levels in YXu55 transgenic plants might help to reduce damage by oxidative stress.