Changes of Sleep Adaptation in Hospitalized Patients with Depression

Sleep adaptation in an unfamiliar environment, the so-called “first-night effect”, is known to occur in healthy individuals. To avoid the confounding effects of the “first-night effect”, the first-night sleep data are not used in most of sleep studies. In the present study, we examined changes of sleep adaptation in hospitalized patients with depression. Polysomnographic recordings were obtained for two consecutive nights from 14 patients, and sleep parameters were compared between both nights. Total sleep time, sleep latency, awakening times, movement awakening time, sleep efficiency, sleep architecture, rapid eye movement (REM) sleep latency, REM intensity, REM density, REM time, REM cycles, and other indicators showed no significant difference (p > 0.05) between the first and second nights. To conclude, hospitalized patients with depression have relatively less change in sleep adaptation, thus, the data from their first night do not need to be discarded.     

不同治疗方式在老年股骨粗隆间骨折中的对照分析

目的:比较分析不同治疗方式对老年股骨粗隆间骨折的治疗效果。方法:回顾性分析152例老年股骨粗隆间骨折患者的临床资料,保守治疗组24例;手术治疗组128例,其中人工股骨头置换23例、外固定架23例、髓内固定28例(包括股骨近端髓内钉(proximal femoral nail,PFN)、Gamma钉等)、动力髋螺钉(dynamic hip screw,DHS)26例、股骨近端锁定钢板(the locking compress plate,LCP)28例。对各种治疗方式的相关指标进行比较分析。结果:手术治疗组患者卧床时间和并发症发生率均显著优于保守治疗组(t=8.045,7.583,8.673,8.023,8.672,X2=9.124,4.809,6.603,4.276,14.444,P0.05);各手术组之间比较:各组卧床时间无显著差异(F=0.241,P0.05),外固定架组和LCP组手术时间、切口长度、出血量及术后引流量均显著优于其余各组(P0.05);保守组术后Harries评分低于手术组。结论:手术治疗老年股骨粗隆间骨折可获得满意疗效,且并发症较少;外固定架创伤较小,LCP和人工股骨头置换术后疗效较好,其中LCP可作为优先考虑方案。     

Electrophysiological Correlates of Major Depression Disorder with Anxious Distress in Patients of Different Age Groups

The electrophysiological correlates of major depression disorder with anxious distress in patients of different age groups have been investigated. The spectral characteristics of 19-channel background EEG were analyzed and the power spectra recorded with the eyes closed vs. eyes open in 64 patients with anxiety–depressive disorder and in 194 healthy subjects were compared. The subjects were divided into the two age groups: 18–39 and 40–76 years old. The spectral parameters were calculated for 5 main EEG frequency bands: θ (4–8 Hz), α (8–12 Hz), β₁ (12–20 Hz), β₂ (20–30 Hz), and γ (30–40 Hz). The most statistically significant differences between the groups were found in the α, β, and γ bands. Lower values of spectral power of the α rhythm in occipital areas and the higher values of spectral power of the β and γ rhythms in the frontocentral region were recorded in the group of 18-to-39-year-old patients with the eyes closed. Higher values of spectral power of the β rhythm in the fronto-central region and in the left temporal lobe were recorded in the group of 40-to-76-year-old patients with both the eyes closed and the eyes open. The higher β-activity in the fronto-central regions in both groups of patients may be caused by increased excitability of the cerebral cortex and decreased activity of inhibitory processes. Increased activation of the left temporal lobe in older subjects is probably associated with the severity of anxiety symptoms and may be a distinctive marker of mixed anxiety and depressive disorder. The lower values of α-power revealed only in the group of younger subjects are probably associated with age-related reorganization of EEG in older subjects.     

Effects of the Seasons and of Bright Light Administered at Different Times of Day on Sleep EEG and Mood in Patients with Seasonal Affective Disorder

The study examines objective characteristics of sleep in women (n=31) with and without seasonal affective disorder, winter type, before and after a week of light treatment (at either 0800-1000 h, 1600-1800 h or 1800-2000 h). Subsamples of 13 patients and 7 controls were studied additionally in summer, and, among these patients, 9 were also recorded in spring and fall. Ranking the results from the lowest to the largest degree of deviation of sleep structure in patients from the norm yields the sequence: spring -> summer -> winter after light treatment -> fall -> winter before light treatment. In winter before light treatment the total amounts and percentage of slow wave sleep were significantly lower in responders to light (n=13) compared to both nonresponders (n=8) and controls (n=10), while following light treatment the difference disappeared. The reduced amounts of slow wave sleep in the depressive state predicted higher reduction and low posttreatment scores on psychiatric scales. Light treatment and summer season showed similar effects on patients' sleep: they caused an increase of slow wave sleep and a decline of sleep stage 2. Our data do not suggest that time of light treatment is important to achieve an antidepressant effect. Moreover, phase shifting effects of light treatment and of changing season on sleep EEG were not considerable. At the same time, subjective ratings of arousal demonstrated an advance shift of the arousal rhythm after morning and a delay shift after afternoon LT. We did not find significant changes in total amounts and percentage of REM sleep over time. The data suggest that abnormally increased need for REM sleep results in the hypersomnia and may be considered as a trait marker of winter depression. An abnormal architecture of nonREM sleep appears to be a state marker of those patients who benefit from bright light administered during waking hours.     

Effects of the Seasons and of Bright Light Administered at Different Times of Day on Sleep EEG and Mood in Patients with Seasonal Affective Disorder

A brief account of the need for removing masking factors, either by protocol or calculation, is given. The strengths and weaknesses of both constant routine protocols and purification methods is outlined. It is concluded that each can contribute to the development of our knowledge of the endogenous component of circadian rhythms.     

不同麻醉方式对老年肺肿瘤患者术后早期认知功能的影响

目的:探讨不同麻醉选择对老年肺肿瘤术后患者早期认知功能的影响。方法:分析我院2011年3月至2013年3月老年肺肿瘤患者,分别有62例用全凭静脉麻醉和61例用静吸复合麻醉的麻醉方法,记录手术时间和麻醉时间,用MMSE量表进行认知功能评分,分别评定手术前1天和手术后出麻醉室时及1、3、5天患者的认知功能,并判断患者的POCD。结果:两组患者在手术时间和麻醉时间方面无统计学差异。与术前1天比较,全凭静脉麻醉组、静吸复合麻醉组出麻醉恢复室时、术后1 d时MMSE评分降低(P0.05);与术前1 d比较,两组在术后3天和7天时MMSE评分恢复正常(P0.05),两组患者之间的MMSE认知功能评分在术前、术后均无统计学差异(P0.05),出麻醉恢复室时,全凭静脉麻醉组发生POCD24例(39.34%),全凭静脉麻醉组发生25例(40.32%),两组发生率比较无统计学差异(P0.05);术后1天、3天、7天两组分别POCD的发生率比较均无统计学意义(P0.05)。结论:老年患者用全凭静脉麻醉、静吸复合麻醉不同麻醉方法对老年患者术后早期发生认知功能障碍的影响无统计学差异。     

Nitric Oxide-Related Biological Pathways in Patients with Major Depression

Background

Major depression is a well-known risk factor for cardiovascular diseases and increased mortality following myocardial infarction. However, biomarkers of depression and increased cardiovascular risk are still missing. The aim of this prospective study was to evaluate, whether nitric-oxide (NO) related factors for endothelial dysfunction, such as global arginine bioavailability, arginase activity, L-arginine/ADMA ratio and the arginine metabolites asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) might be biomarkers for depression-induced cardiovascular risk.

Methods

In 71 in-patients with major depression and 48 healthy controls the Global Arginine Bioavailability Ratio (GABR), arginase activity (arginine/ornithine ratio), the L-arginine/ADMA ratio, ADMA, and SDMA were determined by high-pressure liquid chromatography. Psychiatric and laboratory assessments were obtained at baseline at the time of in-patient admittance and at the time of hospital discharge.

Results

The ADMA concentrations in patients with major depression were significantly elevated and the SDMA concentrations were significantly decreased in comparison with the healthy controls. Even after a first improvement of depression, ADMA and SDMA levels remained nearly unchanged. In addition, after a first improvement of depression at the time of hospital discharge, a significant decrease in arginase activity, an increased L-arginine/ADMA ratio and a trend for increased global arginine bioavailability were observed.

Conclusions

Our study results are evidence that in patients with major depression ADMA and SDMA might be biomarkers to indicate an increased cardiovascular threat due to depression-triggered NO reduction. GABR, the L-arginine/ADMA ratio and arginase activity might be indicators of therapy success and increased NO production after remission.     

腹腔镜与开腹手术治疗不同类型阑尾炎患者的临床效果对比

目的:对比分析腹腔镜与开腹手术治疗不同类型阑尾炎患者的临床效果。方法:从我院2013年3月~2015年9月收治的各种类型的阑尾炎患者中随机抽取106例进行研究,随机分为对照组(53例,行开腹手术)和观察组(53例,行腹腔镜手术),对比两组手术基本指标、疗效及术后并发症的发生情况。结果:(1)观察组的总有效率为94.34%,明显高于对照组的60.38%,差异具有统计学意义(P0.01)。(2)观察组手术时间、住院时间及术中出血量均明显少于对照组,住院费用显著高于对照组,差异均具有统计学意义(P0.05)。(3)对照组总并发症发生率为16.98%,明显高于观察组的3.77%,差异有统计学意义(P0.05)。结论:与开腹手术相比,腹腔镜手术治疗不同类型阑尾炎患者的临床效果更加显著,具有手术创伤小、术后恢复快、安全性高的特点,但住院费用较高,需要根据患者的实际情况和意愿选择合适的手术方式。     

No Major Differences Found between the Effects of Microwave-Based and Conventional Heat Treatment Methods on Two Different Liquid Foods

Extension of shelf life and preservation of products are both very important for the food industry. However, just as with other processes, speed and higher manufacturing performance are also beneficial. Although microwave heating is utilized in a number of industrial processes, there are many unanswered questions about its effects on foods. Here we analyze whether the effects of microwave heating with continuous flow are equivalent to those of traditional heat transfer methods. In our study, the effects of heating of liquid foods by conventional and continuous flow microwave heating were studied. Among other properties, we compared the stability of the liquid foods between the two heat treatments. Our goal was to determine whether the continuous flow microwave heating and the conventional heating methods have the same effects on the liquid foods, and, therefore, whether microwave heat treatment can effectively replace conventional heat treatments. We have compared the colour, separation phenomena of the samples treated by different methods. For milk, we also monitored the total viable cell count, for orange juice, vitamin C contents in addition to the taste of the product by sensory analysis. The majority of the results indicate that the circulating coil microwave method used here is equivalent to the conventional heating method based on thermal conduction and convection. However, some results in the analysis of the milk samples show clear differences between heat transfer methods. According to our results, the colour parameters (lightness, red-green and blue-yellow values) of the microwave treated samples differed not only from the untreated control, but also from the traditional heat treated samples. The differences are visually undetectable, however, they become evident through analytical measurement with spectrophotometer. This finding suggests that besides thermal effects, microwave-based food treatment can alter product properties in other ways as well.     

Evaluation of Different Methods for Extracting Extracellular DNA from the Biofilm Matrix

The occurrence of high concentrations of extracellular DNA (eDNA) in the extracellular matrices of biofilms plays an important role in biofilm formation and development and possibly in horizontal gene transfer through natural transformation. Studies have been conducted to characterize the nature of eDNA and its potential function in biofilm development, but it is difficult to extract eDNA from the extracellular matrices of biofilms without any contamination from genomic DNA released by cell lysis during the extraction process. In this report, we compared several different extraction methods in order to obtain highly pure eDNA from different biofilm samples. After different extraction methods were explored, it was concluded that using chemical treatment or enzymatic treatment of biofilm samples may obtain larger amounts of eDNA than using the simple filtration method. There was no detectable cell lysis when the enzymatic treatment methods were used, but substantial cell lysis was observed when the chemical treatment methods were used. These data suggest that eDNA may bind to other extracellular polymers in the biofilm matrix and that enzymatic treatment methods are effective and favorable for extracting eDNA from biofilm samples. Moreover, randomly amplified polymorphic DNA analysis of eDNA in Acinetobacter sp. biofilms and Acinetobacter sp. genomic DNA and DNA sequencing analysis revealed that eDNA originated from genomic DNA but was not structurally identical to the genomic DNA.A biofilm is a well-organized community of microorganisms that adheres to surfaces and is embedded in the slimy extracellular polymeric substances (EPSs). EPSs are a complex mixture composed of high-molecular-mass polymers (>10,000 Da) generated by the bacterial cells, cell lysis and hydrolysis products, and organic matter adsorbed from the substrate. EPSs are involved in the establishment of stable arrangements of microorganisms in biofilms (40), and it recently was found that extracellular DNA (eDNA) is one of the major components of EPSs (7, 31). eDNA plays a very important role in biofilm development (39), and it is believed to be involved in providing substrates for sibling cells, maintaining the three-dimensional structure of biofilms, and enhancing the exchange of genetic materials (18, 31). eDNA has also been found to be accumulated in cultures of several bacterial species and has been postulated as being released by bacterial cells (11, 15, 21, 30). Although it is commonly accepted that eDNA is released mainly from cell lysis (11, 23, 24, 28, 34, 41), several studies have revealed that some other active secretion mechanisms may exist (1, 6, 11, 27). Recent evidence, however, indicates the possibility that eDNA is secreted actively via transport vesicles for the purpose of creating the biofilm matrix (39). Bockelmann et al. found that eDNA formed a defined, network-like spatial structure in the biofilm of an aquatic bacterium and identified that eDNA was not completely identical to genomic DNA by using randomly amplified polymorphic DNA (RAPD) and restriction endonuclease analyses (3). By using RAPD analysis, principal-components analysis, and terminal restriction fragment length polymorphism analysis, Steinberger and Holden (33) also characterized eDNA in single- and multiple-species unsaturated biofilm and found that it was different from genomic DNA. However, research is still needed to elucidate the role of eDNA in biofilm structures and in the development and origins of eDNA. In order to further investigate these questions, it is important to extract most of the eDNA of high purity in the biofilm matrix and separate eDNA from other components in the EPSs and from the genomic DNA released during the extraction process. Several methods, such as high-speed centrifugation (2, 33) and membrane filtration (3), have been used to isolate eDNA from biofilm samples. However, these methods may isolate only a portion of the eDNA from biofilm samples.EPSs are composed mainly of high-molecular-weight compounds, including polysaccharides, proteins, and amphiphilic polymers (19, 20), that are secreted by microorganisms into their environment (32). The majority of proteins in the EPSs are bridged by divalent ions, including Ca²⁺ and Mg²⁺, and a small fraction of carbohydrates and nucleic acids are linked to these divalent ions. Under neutral conditions, the carboxyl of protein would become ionized and negative. Through ion interaction, the divalent ions bridge the protein and the cells. In addition, eDNA may be physically or chemically associated with extracellular proteins, polysaccharides, and other polymers in the EPS matrix. The structural assemblage of proteins and polysaccharides in the complex matrix of the EPS might hinder the liberating eDNA from the EPS matrix. Therefore, it is difficult to release eDNA and other materials from the EPS matrix by only vortexing or homogenizing. Additionally, it is necessary to degrade certain components of EPSs in the biofilm matrix in order to release eDNAs that may bind to these compounds.In this study, the following extractants were chosen to treat biofilm samples for isolation of eDNA from Acinetobacter sp. strain AC811 biofilm: EDTA and cation-exchange resin (CER) (16), which both have the ability to remove cations from the EPS matrix; sodium dodecyl sulfate (SDS) and NaOH, which are strong denaturants and are used frequently for EPS extraction from various pure and mixed cultures (17, 29); and N-glycanase (glycoprotein degradation hydrolase) (35), dispersin B (biofilm-dispersing glycoside hydrolase) (25), and proteinase K (protein hydrolase). We evaluated the efficiencies of these treatments and their impacts on the quantity and quality of eDNA extracted, and we propose that eDNA may bind to other extracellular polymers in the Acinetobacter biofilm matrix, based on the release of eDNA from the biofilm matrix after such treatments.     

Network Redundancy Analysis of Effective Brain Networks; a Comparison of Healthy Controls and Patients with Major Depression

This study investigated electroencephalographic correlates in chronically depressed patients compared to healthy controls using intracutaneously applied electrical pain stimulus, to better understand the interaction between pain processing and depression. A close interaction between pain and depression is generally recognized although the precise mechanisms are not yet fully understood. The present study focuses on the hypothesis that effective brain connectivity in major depression patients is altered. Multifunctional interactions between brain regions represent a robust index of effective interactions within the brain, and can be quantified by network redundancy. Thus, structural network differences between 18 normal controls and 18 major depression patients before as well as during the processing of moderately painful intracutaneous electrical stimuli were investigated on the basis of network redundancy differences. In our sample, both patients and control subjects exhibit comparable network redundancies before stimulus application. Caused by the stimulus, there is a global increase of network redundancy in both groups. This increase is diminished in the group of major depression patients. We found clear differences between patients and controls during the stimulus processing, where the network redundancy in normal controls is larger in comparison to patients. The differences might be explained by the fact that major depression patients are more restricted to the affective component of the processing. The well-established biasing to affective processing might suppress the somatosensory processing resulting in a lower number of connections within the considered network. This might then lead to a reduction in network redundancy during stimulus processing.     

不同吸痰方法对机械通气患者气道影响及临床效应研究

目的:探讨密闭式和开放式吸痰方法对机械通气患者的影响及临床效应.方法:选择我院机械通气患者83例,随机分为密闭组和开放组,密闭组采用密闭式吸痰方法时机械通气患者进行吸痰,开放组采用开放式吸痰方法对机械通气患者进行吸痰.观察两组患者吸痰前后血氧饱和度(SpO2)的变化、呼吸道粘膜的损伤发生率及肺部感染发生率.结果:吸痰后密闭组呼吸道粘膜损伤发生率显著低于开放组(P＜0.01),肺部感染率显著低于开放组(P＜0.01).结论:密闭式吸痰在机械通气患者气道护理效果方面显著优于开放式吸痰,在机械通气气道护理工作中值得借鉴.     

Treatment of Sleep Disordered Breathing Liberates Obese Hypoxemic Patients from Oxygen

Background

Obese hypoxemic patients have a high prevalence of sleep disordered breathing (SDB). It is unclear to what extent treatment of SDB can improve daytime hypoxemia.

Methods

We performed a retrospective cohort study of obese hypoxemic individuals, all of whom underwent polysomnography, arterial blood gas analysis, and subsequent initiation of positive airway pressure (PAP) therapy for SDB. Patients were followed for one year for change in partial pressure of arterial oxygen and the need for supplemental oxygen.

Results

One hundred and seventeen patients were treated with nocturnal PAP and had follow-up available. Adherence to PAP was satisfactory in 60%, and was associated with a significant improvement in daytime hypoxemia and hypercapnea; 56% of these patients were able to discontinue supplemental oxygen. Adherence to PAP therapy and the baseline severity of OSA predicted improvement in hypoxemia, but only adherence to PAP therapy predicted liberation from supplemental oxygen.

Conclusions

The identification and treatment of SDB in obese hypoxemic patients improves daytime hypoxemia. It is important to identify SDB in these patients, since supplemental oxygen can frequently be discontinued following treatment with PAP therapy.     

睡眠纺锤波在植物状态病人预后判别中的价值研究

目的:探讨脑电图睡眠纺锤波在植物状态病人预后判别中的价值。方法:在长程脑电监测下观察植物状态病人的睡眠纺锤波,与其意识恢复进行相关性分析,并预测患者意识恢复的敏感性、特异性及准确性。结果:28例患者中,12例有纺锤波,其中9例意识恢复;16例无纺锤波患者中,14例未恢复意识。纺锤波的有无与患者意识恢复有相关性,P值<0.01。脑电图睡眠纺锤波对植物状态患者意识恢复判断的敏感性(83.25%)、特异性(81.82%)、准确性(82.14%)。结论:脑电图睡眠纺锤波可较准确预测植物状态患者的意识恢复能力,可作为临床评估植物状态患者意识恢复能力的辅助方法。     

不同方法修复Pilon骨折的临床疗效比较

目的:比较不同方法修复Pilon骨折的临床疗效。方法:选取我院收治的Pilon骨折患者156例为研究对象,根据手术方法不同,将患者分成研究组和对照组,每组78例。研究组给予分步延期切开复位内固定手术治疗,对照组给予有限内固定结合外固定的手术治疗。观察并比较两组患者的踝关节功能、术中出血量、骨折愈合时间、住院时间以及术后不良反应的发生情况等。结果:与术前比较,两组患者术后踝关节功能均获得改善,且研究组踝关节功能优秀率高于对照组,差异具有统计学意义(P0.05);研究组患者术中出血量、骨折愈合时间、住院时间均明显低于对照组,差异具有统计学意义(P0.05);研究组不良反应发生率低于对照组,差异具有统计学意义(P0.05)。结论:分步延期切开复位内固定手术治疗pilon骨折的临床效果显著,是临床治疗pilon骨折的理想方案。但在临床实践中,应根据患者病情选择合适的治疗方案。     

野生鸡枞菌种长期保存方法比较

野生鸡枞菌种质资源的有效保存是对野生鸡枞加以保护和利用的前提。以自行分离的5个野生鸡枞菌株作为研究对象,采用蒸馏水保藏法和-80°C冻结保藏法对野生鸡枞菌种长期保存的方法进行了实验研究,蒸馏水法分别保存于室温和4°C,-80°C冻结保藏同时采用程控降温法和泡沫盒降温法,保存20个月后对4种不同方法保存的5个菌株的保存效果进行比较。实验结果表明:蒸馏水室温保存法菌种存活率为100%,萌发期较短,为4-10 d,是一种简便、实用、有效而成本低廉的长期保存方法;-80°C冻结保藏法的存活率为56%-76%,萌发期7-16 d,泡沫盒降温法可以很好地控制降温速度,是一种简便有效的控温方法。     

不同治疗方案对原发免疫性血小板减少症患者外周血调节T细胞水平变化的影响及其意义分析(英文)

目的:探讨原发免疫性血小板减少症(immune thrombocytopenia,ITP)患者治疗前后外周血调节性T细胞(regulatory T cell,Treg)水平变化及其在ITP发病中的作用。方法:选取2010年6月至2013年7月间276例新诊断ITP患者,男114例、女162例,中位年龄40(18-70)岁。按治疗方案随机分为地塞米松组(90例):地塞米松40 mg/d第1~4天口服;泼尼松组(98例):泼尼松1.5 mg·kg-1·d-1口服;2泼尼松组(98例):泼尼松1.5 mg·kg-1·d-1口服;地塞米松+小剂量利妥昔单抗组(88例):地塞米松40 mg/d第1-4天口服,利妥昔单抗100 mg第7、14、21、28天静脉滴注。各组患者于治疗前、治疗后14 d和28 d分别采取外周静脉血,采用流式细胞术检测CD4+CD25+CD127-细胞水平。以60名健康体检者为正常对照组。结果:治疗后第28天,地塞米松组、泼尼松组、地塞米松+小剂量利妥昔单抗组的总有效率分别66.7%、69.4%、79.5%,差异无统计学意义;随访12个月,泼尼松组(37.8%)和地塞米松组(22.7%)之间差异无统计学意义,而与地塞米松+小剂量利妥昔单抗组持续有效率(66.7%),差异有统计学意义(P0.05)。所有ITP患者治疗前外周血CD4+CD25+CD127-细胞表达水平低于健康对照组[(1.66±0.69)%对(4.01±0.38)%,P0.05];地塞米松组、泼尼松组患者治疗后14d CD4+CD25high CD127low细胞水平均高于治疗前[(3.46±0.76)%对(1.68±0.72)%、(3.22±0.77)%对(1.69±0.74)%,P值均0.05];地塞米松+小剂量利妥昔单抗组治疗后14、28d CD4+CD25+CD127-细胞水平[(4.27±1.08)%、(4.43±0.62)%]均高于治疗前[(1.67±0.67)%],差异有统计学意义(P值均0.05);治疗后28 d,泼尼松组、地塞米松组患者CD4+CD25+CD127-细胞水平[(2.68±0.63)%、(2.58±0.66)%]与治疗前比较差异无统计学意义。结论:地塞米松联合小剂量利妥昔单抗在长期疗效及提升T细胞数量方面显著优于地塞米松和泼尼松,值得临床推广。     

刺五加多糖提取过程中不同脱蛋白方法的比较研究

研究比较了Sevag法、三氯乙酸法(TCA)-Sevag法、壳聚糖絮凝法和酶法四种方法对刺五加多糖的脱蛋白效果.结果表明:Sevag法、三氯乙酸法(TCA)-Sevag法、壳聚糖絮凝法和酶法的蛋白脱除率分别为28%、83%、93.1%、93.1%;多糖损失率分别为18%、43%、47%、7%.比较这四种脱蛋白方法,酶法具有良好的脱蛋白效果.     

红曲霉不同转化方法比较

为了研究红曲霉聚酮体途径,考察和比较了4种不同的转化方法以建立有效的红曲霉遗传转化系统。以潮霉素作为抗性筛选标记,pBC-Hygro作为转化载体,用基于原生质体的传统转化和电击转化、基于萌发孢子的电击转化以及REMI技术转化红曲霉。发现基于萌发孢子的电击转化由于转化率极低而不适于红曲霉转化。基于原生质体的传统转化和电击转化尽管每微克DNA分别能获得135个转化子和125个转化子,但因转化子稳定性差也适合红曲霉转化的转化。应用REMI技术,转化率提高约20倍,每微克DNA 2500个转化子,70%～75%的转化子的稳定,非常适合于红曲霉的转化。      

噬菌体浓缩方法的比较

目的：对不同噬菌体浓缩方法进行比较。方法：采用PEG沉淀、PEG反透析、阴阳离子结合树脂、超滤等5种方法对T4、T7、N4等3类噬菌体进行浓缩对比试验;在此基础上,用浓缩效果较好的方法对土壤和河道污水样本中的噬菌体进行浓缩,观察浓缩效果。结果：上述5种方法对3类噬菌体均有浓缩效果;超滤的浓缩效果最好,其次是PEG反透析,PEG沉淀没有很好的浓缩效果;河水样本中噬菌体的回收率比土壤样本高。结论：可通过PEG反透析、超滤或两者相结合的方法,得到高浓度的有活性的噬菌体。