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

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

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

ObjectiveTo investigate whether brain microbleeds is associated with antiplatelet-related intracranial hemorrhage (ICH). MethodsForty-three patients with antiplatelet-related ICH treated in our hospital from Jun 2005 to Jun 2010 were investigated in this study.Age, sex and hypertension matched controls with non-antiplatelet-related ICH; and without history of ICH on antiplatelet therapy were selected. ResultsMicrobleeds was more frequent in antiplatelet users with ICH than in matched antiplatelet users without ICH(31/43(72. 1％ ) vs 12/57(21.1％ ), x2 =6. 731, P =0. 011 ) and was more frequent in IHC patients with antiplatelet treatment than those with non-antiplatelet treatment (31/43 (72. 1％ ) vs 17/48 (35.4％), P =0. 030). The frequency of lobar microbleeds(27/43, 62. 8％ ) was significant high in antiplatelet-related ICH than that in non antiplatelet-related ICH (19/48, 39. 6％, x2 =4. 019, P =0. 042). The number of microbleeds was associated with the risk of antiplate-related ICH ( OR =1.38 per additional microbleed, 95％ CI 1.07-1.71, t =0. 806, P =0. 021 ). ConclusionBrain microbleeds are associated with antiplatelet-related ICH.

This research adopts both quantitative and qualitative analytical methods to analyze high-frequency medical words, morphemes and clusters, with the aid of corpora and statistical measures. The result of this research can help teachers arrange their teaching according to the difficulty and frequency of the words, morphemes and clusters.For students, they can put more time and effort on these frequently used words, morphemes and clusters, and thus improve learning efficiency.

Objective To compare the value of prostatic specific antigen(PSA),prostate volume (PV)and PSA density(PSAD)in healthy Chinese males between Uygur and Han and to analyze the relationship between age and above indexes.Methods Serum PSA of 1278 healthy Chinese men over than 40 years was measured by enzyme linked immunosorbent assay.The group composed of 555 Uygur males and 723 Han males was divided into four different age groups based on every ten years.40-49 year group: 395 (Uygur: 175,Han: 220);50-59 year group: 325(Uygur: 143,Han: 182);60-69 year group: 281(Uygur: 131,Han: 150);over than 70 year group: 277(Uygur: 106,Han: 171).The length,width and height of the prostate were measured by trans-abdominal ultrasound.The value of PSA,PV and PSAD were correlated with age using the correlation analysis.Results PSA and PV of Uygur were as follows,40 year group:(0.69 ± 0.50)μg/L,(22.83 ± 8.20)ml;50 year group:(0.87 ± 0.52)μg/L,(25.30 ± 9.27)ml;60 year group:(1.08 ±0.56)μg/L,(27.68 ±13.10)ml;70 year group:(2.39 ±0.99)μg/L,(36.36 ± 18.71)ml.PSA and PV of Han were as follows,40 year group:(1.01 ± 0.83)μg/L,(23.01 ±7.57)ml;50 year group:(1.26 ±0.80)μg/L,(27.23 ±10.24)ml;60 year group:(1.66 ±0.79)μg/L,(33.88±17.59)ml;70 year group:(2.51 ±1.11)μg/L,(43.98 ±20.21)ml.The value of PSA and PV of Uygur were less than those of Han in each age group and there were significant differences(P ＜ 0.05).PSAD of Uygur and Han in different age group were as follows: 40 year group:0.041 ± 0.022,0.042 ± 0.027;50 year group: 0.039 ± 0.027,0.040 ± 0.031;60 year group: 0.040 ±0.021,0.041 ±0.025;70 year group: 0.039 ± 0.020,0.040 ± 0.029.The PSAD showed no difference between two nationalities or any age group.With the increasing age,the value of PSA and PV gradually increased and the positive correlation was found among age,PSA and PV in both Uygar and Han nationalities.Conclusions The value of PSA and PV are affected by nationality and age.PSAD between different nationalities and age groups has no difference.

Objective To observe and investigate the correlation of hemodynamic change of cerebral vessels and functional disturbance in cerebral infarction patient.Methods To investigate hemodynamic characters of cerebral vessels in every type and every group patients via comparing cerebral infarction group(observe group)with control group,comparing stage of recovery with early stage, sever, moderate, mild degree in observe group.Results Apparent hemodynamic change was observed in above 94.10% cerebral infarction patients. The more apparent the hemodynamic change,the severer the functional disturbance.Conclusion The hemodynamic change of cerebral vessels is the predictive index of state of illness and prognosis of cerebral infarction patient.Clinical doctor should pay enough attention to modify it in treatment.

Bradykinin (BK) is a calcium/calmodulin dependent protein kinase Ⅱ (CaMKⅡ) specific activator, and Cyclosporin A (CSA) is reported to suppress protein phosphotase (PP)-2B activity. In vitro studies have shown that CaMKⅡ and PP-2B play an important role in Alzheimer-like phosphorylation of microtube-associated protein tau. To reconstitute an animal model based on the imbalance of protein kinase (s) and protein phosphatase (s) seen in Alzheimer brain, we injected BK and/or CSA into rat hippocampus. The results from behavioral study showed that an obvious disturbance in learning and memory was seen with BK or BK plus CSA injected rats. Moreover, the behavior abnormality appeared earlier in aged rats than young adults of the same kind after the injection. On the other hand, no obvious dysfunction in living and behavior was observed with CSA alone injected rats. The results obtained by immunohistochemical assay indicated that the staining for M4\, 12E8\, PHF-1 and CaMKⅡ was stronger, and for Tau-1 was weaker in BK injected rats compared with Control group. It was also found that the binding of M4 and PHF-1 but not 12E8 to tau was significantly increased in CSA injected rats. As the same as BK injection, binding of Tau-1 to tau was decreased after CSA injection. The immunostaining for 12E8\,PHF-1 and CaMKⅡ was increased, whereas for Tau-1\, M4\, and GSK-3 was decreased after combination injection of BK and CSA. In addition, the staining of PP-2B decreased in all the three models. To our knowledge, this is the first data shown in vivo that the activation of CaMKⅡ induces both Alzheimer-like tau phosphorylation and behavioral disturbance.

Objective To explore the effect of NO on secondary spinal cord injury. Method L - arginine{L - Arg} and N - nitric-Larginine methylester{L - NAME} were infused into subarachnoid space of rats 30 min before spinal cord injury(SCI) . Spinal cord blood flow (SCBF) at trauma sites was monitored. After SCI by a Laser - Doppler flowmetry and neurological function was evaluated. Result The result showed that L - arg increased SCBF at trauma sites, but exaggerated the SCI. The proper dose of L - NAME decreased early SCBF at trauma sites, but ameliorated neural function. Large dose of L - NAME restricted NO production for a long time and resulted in spinal cord isehemia, thus exacerbating SCI. Conclusion That over - production or over - restriction of NO worsen SCI.

A new method for simultaneous spectrophotometric determination of Zn, Cd and Hg using 2-(5-Br-2-pyridylazo)-5-diethylaminophenol as the color developing reagent was proposed. The absorption spectra of these three complexes have similar features with severe overlap in visible spectral range. For resolving these spectra, hybrid linear analysis was used, and the pure spectrum of each component was obtained from the calibration mixtures by least squares method. The effects of reaction condition, selection of wavelengths, determination of pure spectrum and additivity of absorbances etc. on the determination were discussed. The proposed method offers the advantages of simple, rapid, and accuracy. It has been successfully applied to the simultaneous determination of Zn, Cd and Hg in synthetic sample. A comparison was also made with the partial least squares method.