Legionella pollution in cooling tower water of air-conditioning systems in Shanghai, China

Aims:  To determine Legionella pollution prevalence, describe the amount of Legionellae with respect to temperature in Shanghai cooling tower water (CTWs) in various types of public sites.
Methods and Results:  Six urban districts were selected as the study fields, adopting multiple-phase sampling methods. Routine culture was used to identify Legionellae. Of the samples, 58·9% (189/321) were observed to be positive, 19·9% were isolated over 100 CFU ml⁻¹. Legionella pneumophila serogroup 1 was the most frequently isolated species (155/189, 82·0%), followed by Leg. micdadei that was at the second place (44/189, 23·3%). The mean CFU ml⁻¹ of Legionellae in CTWs reached its peak from July to September. Over all 15·4% of the samples exceeding 100 CFU ml⁻¹ were observed in a hospital setting.
Conclusions:  The prevalence of Legionella pollution in CTWs, especially in CTWs of subway stations and hospitals, is worrying, and the positive rate and CFU ml⁻¹ of Legionellae in CTWs have a close relationship with air temperature.
Significance and Impact of the Study:  The study demonstrates pollution prevalence rates in different types of sites and various seasons, and provides a proportion of different serogroups of Legionellae . It illuminates an urgent need for dealing with the potential risk of legionellosis in Shanghai, through improved control and prevention strategies.     

尼罗蓝在筛选PHB高产菌株中的应用研究

建立一种简便、高效、可靠的初筛方法是PHB高产菌株筛选的关键。以芽孢杆菌(BacillusP-9)为试验材料,对各种PHB产生菌筛选方法进行了比较,最终确定尼罗蓝染色法为一种最佳方法。并且对试验程序进行了优化,确定尼罗蓝染液的最佳浓度为0.225mg/L,菌株的最佳染色时间为培养后96h。进一步证实了尼罗蓝染色法为一种值得推广的PHB产生菌初筛方法。     

Breastfeeding in China: a review

This review aims to describe changes in breastfeeding and summarise the breastfeeding rates, duration and reasons of discontinuing 'any breastfeeding' or 'exclusive breastfeeding' in P.R. China. Breastfeeding rates in China fell during the 1970s when the use of breast milk substitutes became widespread, and reached the lowest point in the 1980s. As a result many efforts were introduced to promote breastfeeding. The breastfeeding rate in China started to increase in the 1990s, and since the mid-1990s 'any breastfeeding' rates in the majority of cities and provinces, including minority areas, have been above 80% at four months. But most cities and provinces did not reach the national target of 'exclusive breastfeeding' of 80%. The 'exclusive breastfeeding' rates in minority areas were relatively lower than comparable inland provinces. The mean duration of 'any breastfeeding' in the majority of cities or provinces was between seven and nine months. The common reasons for ceasing breastfeeding, or introducing water or other infant food before four months, were perceived breast milk insufficiency, mother going to work, maternal and child illness and breast problems. Incorrect traditional perceptions have a strong adverse influence on 'exclusive breastfeeding' in less developed areas or rural areas. China is a huge country, geographically and in population size, and there is considerable ethnic diversity. Therefore breastfeeding rates in different parts of China can vary considerably.     

Determination of propafenone hydrochloride by flow‐injection analysis coupled with resonance light scattering detection

A simple, sensitive and rapid flow injection analysis (FIA) method with resonance light scattering (RLS) was described for the determination of propafenone (PPF). The method was based on the ion‐association reaction of 12‐tungstophosphoric acid (TP) with propafenone. In pH 1.0 acidic medium, TP reacted with PPF to form an ion‐associate complex, which resulted in a significant enhancement of RLS intensity. The maximum scattering peak was located at 340 nm, the RLS intensity was proportional to the concentration of PPF in the range 0.003–9.0 µg/mL, and the detection limit (3σ) of 1.0 ng/mL was obtained at a sampling rate of 60 samples/h. The feasible reaction conditions and FIA parameters for the system were optimized. The method proposed in this paper shows satisfactory reproducibility with a relative standard deviation (RSD) of 2.1% for 10 successive determinations of 2.0 µg/mL PPF. The present method had been successfully applied to the determination of PPF in serum samples and pharmaceutical samples. The results obtained were in agreement with the method used in the Chinese Pharmacopoeia. Copyright © 2008 John Wiley & Sons, Ltd.     

The study of mitochondrial A3243G mutation in different samples

Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes syndrome (MELAS) is the most frequent syndromic manifestation of A3243G mutation in mitochondrial DNA. Detection of A3243G mutation in blood is less helpful for the diagnosis of MELAS and the carriers, and the mutation ratio in blood correlates only in a limited extent with the severity of the disease. Here we compared the ratio of A3243G mutation in four easily available samples (blood, urine, hair follicle and saliva) in patients with MELAS carrying A3243G mutation as well as their maternal relatives from 32 families, to find out the samples appropriate for the detection of the patients and carriers and useful for the evaluation of clinical severity from their mutation ratio. In MELAS patients and the carriers with minor symptoms or normal phenotype, A3243G mutation ratio was significantly higher in urine than in blood. A close correlation between A3243G mutation ratio in blood and that in urine, hair follicles and saliva was found in the probands and their relatives. Clinical features closely correlated with the mutation ratio in urine. Measurement of A3243G mutation ratio in urine is a non-invasive, convenient and rapid method with its diagnostic meaning superior to blood testing.     

文昌鱼GFP基因的鉴定及表达分析

近年在隶属头索动物亚门的文昌鱼体内发现有内源性绿色荧光蛋白存在,并发现文昌鱼荧光蛋白的发光现象在不同发育时期以及个体间有较大的差异。为了进一步揭示GFP基因在文昌鱼中的进化模式,探索其可能执行的功能,该文首先对白氏文昌鱼(Branchiostoma belcheri)GFP基因作了全面鉴定,并对其不同发育阶段胚胎及成体不同区域中的荧光信号进行了实时观察记录,进而对GFP基因在绿色荧光表达强烈的两个特定时期做了绝对定量检测。研究结果表明,文昌鱼基因组中至少有12个内源性GFP基因,在个体发育的不同时期,内源性荧光出现的位置有所变化,而且在变态后的个体之间出现荧光的情况差异较大,荧光蛋白基因的表达由多个GFP同源基因共同参与,这些基因在不同的发育时期表达量有较大的差异,提示不同的GFP基因在特定发育阶段可能行使各自的功能。     

几种经济作物根际拮抗细菌的多样性

采用抗菌谱测定以及BOXAIR-PCR、生理生化特征和16S rDNA序列分析等方法对分离自10种作物根际的55株拮抗细菌的多样性及主要拮抗菌类群进行了分析.结果表明： 根际拮抗细菌的拮抗作用具有丰富的多样性;BOXAIR-PCR分析中供试菌在721％相似性水平上可以聚为7个群,850%相似性水平上聚为25个群;所有供试根际拮抗菌分别属于芽孢杆菌属（Bacillus）芽孢杆菌属（Paenibacillus）、短芽孢杆菌属（Brevibacillus）、假单胞菌属（Pseudomonas）和产碱菌属（Alcaligenes）.作物根际拮抗菌具有丰富的遗传多样性和拮抗性能多样性.     

Challenge in pathologic diagnosis of Alport syndrome: evidence from correction of previous misdiagnosis

Background

Pathologic studies play an important role in evaluating patients with Alport syndrome besides genotyping. Difficulties still exist in diagnosing Alport syndrome (AS), and misdiagnosis is a not-so-rare event, even in adult patient evaluated with renal biopsy.

Methods

We used nested case–control study to investigate 52 patients previously misdiagnosed and 52 patients initially diagnosed in the China Alport Syndrome Treatments and Outcomes Registry e-system.

Results

We found mesangial proliferative glomerulonephritis (MsPGN, 26.9%) and focal and segmental glomerulosclerosis (FSGS, 19.2%) were the most common misdiagnosis. FSGS was the most frequent misdiagnosis in female X-linked AS (fXLAS) patients (34.8%), and MsPGN in male X-linked AS (mXLAS) patients (41.2%). Previous misdiagnosed mXLAS patients (13/17, 76.5%) and autosomal recessive AS (ARAS) patients (8/12, 66.7%) were corrected after a second renal biopsy. While misdiagnosed fXLAS patients (18/23, 78.3%) were corrected after a family member diagnosed (34.8%) or after rechecking electronic microscopy and/or collagen-IV alpha-chains immunofluresence study (COL-IF) (43.5%) during follow-up. With COL-IF as an additional criterion for AS diagnosis, we found that patients with less than 3 criteria reached have increased risk of misdiagnosis (3.29-fold for all misdiagnosed AS patients and 3.90-fold for fXLAS patients).

Conclusion

We emphasize timely and careful study of electronic microscopy and COL-IF in pathologic evaluation of AS patients. With renal and/or skin COL-IF as additional criterion, 3 diagnosis criteria reached are the cutoff for diagnosing AS pathologically.

     

Existence of memory in membrane channels: analysis of ion current through a voltage‐dependent potassium single channel

Ion current fluctuation of voltage‐dependent potassium channel in LβT2 cells has been investigated by autocorrelation function and DFA (detrended fluctuation analysis) methods. The calculation of the autocorrelation function exponent and DFA exponent of the sample was based on the digital signals or the 0–1 series corresponding to closing and opening of channels after routine evolution, rather than the sequence of sojourn times. The persistent character of the correlation of the time series was evident from the slow decay of the autocorrelation function. DFA exponent α was significantly greater than 0.5. The main outcome has been the demonstration of the existence of memory in this ion channel. Thus, the ion channel current fluctuation provided information about the kinetics of the channel protein. The result suggests the correlation character of the ion channel protein non‐linear kinetics indicates whether the channel is open or not.