Microbial genome reduction and modification are important strategies for constructing cellular chassis used for synthetic biology. This article summarized the essential genes and the methods to identify them in microorganisms, compared various strategies for microbial genome reduction, and analyzed the characteristics of some microorganisms with the minimized genome. This review shows the important role of genome reduction in constructing cellular chassis.
Genes, Essential ; genetics ; Genetic Engineering ; Genome, Microbial ; genetics ; Synthetic Biology ; methods

The quality of sleep has a great relationship with health and working efficiency. The result of sleep stage classification is an important indicator to measure the quality of sleep, and it is also an important way to diagnose and treat sleep disorders. In this paper, the method of detrended cross-correlation analysis (DCCA) was used to analyze sleep stage classification, sleep electroencephalograph signals, which were extracted from the MIT-BIH Polysomno graphic Database randomly. The results showed that the average DCCA exponent of the awake period is smaller than that of the first stage of non-rapid eye movement (NREM) sleeps. It is well concluded that the method of studying the sleep electroencephalograph with this method is of great significance to improve the quality of sleep, to diagnose and to treat sleep disorders.
Electroencephalography ; Humans ; Signal Processing, Computer-Assisted ; Sleep Stages

When people are walking, they will produce gait signals and different people will produce different gait signals. The research of the gait signal complexity is really of great significance for medicine. By calculating people's gait signal complexity, we can assess a person's health status and thus timely detect and diagnose diseases. In this study, the Jensen-Shannon divergence (JSD), the method of complexity analysis, was used to calculate the complexity of gait signal in the healthy elderly, healthy young people and patients with Parkinson's disease. Then we detected the experimental data by variance detection. The results showed that the difference among the complexity of the three gait signals was great. Through this research, we have got gait signal complexity range of patients with Parkinson's disease, the healthy elderly and healthy young people, respectively, which would provide an important basis for clinical diagnosis.
Aged ; Gait ; Healthy Volunteers ; Humans ; Parkinson Disease ; physiopathology ; Reference Values ; Signal Processing, Computer-Assisted ; Walking

OBJECTVEThis study evaluates the expression of interleukin-18 (IL-18) and hypoxia-inducible factor (HIF)-lα in rat periodontitis model exposed to normoxia and chronic intermittent hypoxia (CIH) environments. The possible correlation between periodontitis and obstructive sleep apnea-hypopnea syndrome (OSAHS) was also investigated. Methods: Thirty-two Sprague-Dawley (SD) rats were randomly assigned into four groups: normoxia control, normoxia periodontitis, hypoxia control, and hypoxia periodontitis groups. The periodontitis models were established by ligating the bilateral maxillary second molars and employing high-carbohydrate diets. Rats in hypoxia control and hypoxia periodontitis groups were exposed to CIH treatment mimicking a moderately severe OSAHS condition. All animals were sacrificed after eight weeks, and the clinical periodontal indexes were detected. The levels of IL-18 and HIF-1α in serum and gingival tissues were determined using enzyme-linked immunosorbent assay (ELISA). The correlation between attachment loss (AL) and the levels of IL-18 and HIF-lα in hypoxia periodontitis group was evaluated.

RESULTSThe levels of IL-18 and HIF-lα in hypoxia periodontitis group were significantly higher than that in normoxia periodontitis and hypoxia control groups (P<0.05). Furthermore, the levels of IL-18 and HIF-lα in serum (r-0.792, r=0.753, P<0.05) and gingival tissues (r-0.817, r=0.779, P<0.05) were positively correlated with AL.

CONCLUSIONCIH could aggravate the destruction of periodontal tissues, which is correlated with IL-18 and HIF-lα levels.

Animals ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Gingiva ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit ; Interleukin-18 ; Periodontal Index ; Periodontitis ; Rats ; Rats, Sprague-Dawley ; Serum ; Sleep Apnea, Obstructive

BACKGROUND: The nano-hydroxyapatite (NHA) biomaterials compounded with secondary phase or multiphase materials have been widely used in the domain of stomatology, and there have been several reports regarding the application of compounded NHA with composite resin. OBJECTIVE: To analyze the application progress of NHA in the domain of stomatology, and to prospect the potential significance of NHA in the stomatology materials. METHODS: Databases of Pubmed, EBSCOhost and China Journal Full-text were retrieved to screen out the articles. Inclusion crteria: ①The articles possess originality and dependable point and evidence. ②The articles have conclusive viewpoint and allround analyses. ③The agents of articles contact with this review closely.Exclusion criteria:repetition research and independent literatures with this review. And 24 literatures in accordance with the standard were selected in this study. RESULTS AND CONCLUSION: Many clinical application and animal experiments indicate that NHA has been extensively used in the oral surgery, endodontic, implantation and the other aspects, with the deeply research for combination of NHA and composite resin, NHA hopefully displays greater effectiveness in the stomatology materials.

BACKGROUND: Fms-like tyrosine kinase-3 (FLT3) gene is one of the receptors for growth factors in early hematogenesis. By binding to its ligand (FL), FLT3 regulates the proliferation and differentiation of hematopoietic stem/pregenitor cells via cell signal transduction pathway. FLT3 juxtamembrane internal tandem duplication (ITD)mutation is correlated with leukemia onset, development and act as an independent factor for poor prognosis.OBJECTIVE: To explore the relationship between Flt-3/ITD mutation and acute leukemia (AL), and analyze its clinical implication.DESIGN: A repetitive measurement.SETTING: Department of Biochemistry and Molecular Biology, Shenyang Medical College.PARTICIPANTS: Totally 147 samples of leukemia patients were diagnosed by morphological bone marrow biopsy in Shenyang Central Hospitals affiliated to Shenyang Medical College from January 1999 to October 2004. They were 95 males and 52 females with the mean age of 14.5 years old (5-23 years old). According to FAB standard, there were 62 patients with acute leukemia [including 33 cases of acute myelocytic leukemia (AMLs, M1, M2), 3 cases of acute myelo-monocytic leukemia (AMMOLs, M4), 18 cases of acute monocytic leukemia (AMOLs, M5), 8 cases of acute megakaryocytic leukemia (AMKLs, M7)], 43 patients with acute lymphoblastic leukemia (ALLs), 13 patietns with juvenile chronic myelocytic leukemia (JCMLs) and 29 patients with myelodysplastic syndrome (MDSs). Informed contents were obtained from all the participants.METHOD: Flt-3/ITD was detected with polymerase chain reaction (PCR) sequence in the 147 leukemia patients.MArN OUTCOME MEASURES: The clinical manifestations and prognosis were observed in the ALL patients with Flt-3/ITD;The Flt-3 gene expression, Flt-3/ITD positive rate, duplication region and length were detected in all kinds of leukemia.to Flt-3 gene products, including 3 cases of AMLs (M1, M2), 1 case of AMMOL (M4), and 1 case of AMOL (M5). DNA sequencing and blast alignment revealed that ITDs existed in all samples with unusual products within exon 11, in various region and length (33-72 bp). Expression of Flt-3 in different levels was found in 43 cases of ALL, 29 cases of Flt-3/ITD all died short after the diagnosis, and the mean life span of was only 10.8 months.

The genetic diagnosis of hemophilia is a basic method for preventing the birth of hemophilia patients and a basic way for realizing the aim of aristogenesis.Direct and indirect genetic diagnosis is a basic strategy for screening of hemophilia;while in indirect genetic diagnosis,more attention should be paid on the information given by the intro-genetic sites combined with the extra-genetic sites.

Objective To observe dynamic changes of Nestin and Erythropoietin(EPO)expression after cerebral ischemia and investigate possible mechanism of intrinsic neurogenesis. Methods A total of 36 SpragueDawley rats were divided into a control group(n=4)and an experimental group(n=32)randomly.The experimental group were further divided into 8 subgroups corresponding to the observation time points of 3,6,12,24 hours and 3,7,14,and 21 days after reperfusion.The model of experimental ischemia was made by 4-VO.The specimens were made into paraffin section.The expression of Nestin and EPO were detected by immunohistochemistry method. Results (1)Nestin detection:No Nestin positive cells were observed in hippocampal zone,subventricular zone (SVZ)and contex in the control group.The expression of Nestin started at 3 h in SVZ but not in hippocampal zone and it started to increase at 6 h after cerebral ischemia and reach a peak at 14d after cerebral isehemia in the hippocampal zone,then decreased at 21 d.The difference of Nestin expression among different time points is statistically significant(P<0.05).(2)EPO detection:A few EPO positive cells were observed in hippocampal zone in the control group.The expression of EPO started to increase at 3 h after cerebral ischemia and reach a peak at 24 h after cerebral ischemia,then decreased with time.The difference of EPO expression among the different time points is statistically significant(P<0.05). Conclusion (1)The increased expression of EPO and Nestin after cerebral ischemia might be a beneficial protective response of cells to the ischemic injury.(2)The sequence of expression of EPO and Nestin after cerebral ischemia is relevant.EPO may promote proliferation of NSC.

Most academic information appears in the database and academic websites;in rencent years the blog and podcast also transmit academic information.Medical graduates need to check new information regularly after busy routine work,but how to effectively collect and manage academic information is a problem.This paper describes the new strategies and methods for them to use.

Energy metabolism varies in different periods during the lifetime or in different pathological states. Resting energy expenditure (REE) may increase in some patients with malignant tumors, but may also show no significant difference when compared with healthy people or patients with benign tumors. The alteration of REE may be related to tumor site, pathologic stage, methods of treatment, and/or laboratory tests. The efficacy of a certain therapy may also affect REE in patients with malignant tumors: when a therapy is effective, the value of REE can return normal; however, when the treatment fails, REE will not be improved or become even higher.Mechanism governing the abnormalities of REE in patients with malignant tumors may be associated with the abnormal nutrition metabolism and the regulations of relevant cytokines.