Molecular mechanisms of severe acute respiratory syndrome (SARS)

Background

The mechanisms during the initial phase of oxygen toxicity leading to pulmonary tissue damage are incompletely known. Increase of tumour necrosis factor alpha (TNFalpha) represents one of the first pulmonary responses to hyperoxia. We hypothesised that, in the initial phase of hyperoxia, TNFalpha activates the caspase cascade in type II pneumocytes (TIIcells).

Methods

Lung sections or freshly isolated TIIcells of control and hyperoxic treated rats (48 hrs) were used for the determination of TNFalpha (ELISA), TNF-receptor 1 (Western blot) and activity of caspases 8, 3, and 9 (colorimetrically). NF-kappaB activation was determined by EMSA, by increase of the p65 subunit in the nuclear fraction, and by immunocytochemistry using a monoclonal anti-NF-kappaB-antibody which selectively stained the activated, nuclear form of NF-kappa B. Apoptotic markers in lung tissue sections (TUNEL) and in TIIcells (cell death detection ELISA, Bax, Bcl-2, mitochondrial membrane potential, and late and early apoptotic cells) were measured using commercially available kits.

Results

In vivo, hyperoxia activated NF-kappaB and increased the expression of TNFalpha, TNF-receptor 1 and the activity of caspase 8 and 3 in freshly isolated TIIcells. Intratracheal application of anti-TNFalpha antibodies prevented the increase of TNFRI and of caspase 3 activity. Under hyperoxia, there was neither a significant change of cytosolic cytochrome C or of caspase 9 activity, nor an increase in apoptosis of TIIcells. Hyperoxia-induced activation of caspase 3 gradually decreased over two days of normoxia without increasing apoptosis. Therefore, activation of caspase 3 is a temporary effect in sublethal hyperoxia and did not mark the "point of no return" in TIIcells.

Conclusion

In the initiation phase of pulmonary oxygen toxicity, an increase of TNFalpha and its receptor TNFR1 leads to the activation of caspase 8 and 3 in TIIcells. Together with the hyperoxic induced increase of Bax and the decrease of the mitochondrial membrane potential, activation of caspase 3 can be seen as sensitisation for apoptosis. Eliminating the TNFalpha effect in vivo by anti-TNFalpha antibodies prevents the pro-apoptotic sensitisation of TIIcells.     

肾综合征出血热病毒在恙螨体内增殖的动态观察

取饲养的小盾纤恙螨幼虫和若虫．每20d为一批制成无菌滤液接种Vero-E6细胞测定HFRSV滴度,动态观察HFRSV在螨体内的增殖情况,并用PCR技术检测恙螨幼虫和若虫体内HFRSV－RNA。结果如下：小盾纤恙螨幼虫期除60d一批外,其余各批均在不同时间内测出HFRSV滴度,3批若虫中亦有2批测出HFRSV滴度并检测到HFRSV－RNA。结果为小盾纤恙螨作为HFRS的传播媒介提供了进一步的证据。     

人多肽链延伸因子1α四个反转录假基因的鉴别与定位

人多肽链延伸因子1α基因EEF1A是一个在蛋白质合成过程中起重要作用的看家基因。通过对已有GenBank、GDB等数据库的综合分析,鉴别了4个人类多肽链延伸因子1α基因的反转录假基因,并分别将其精细定位于4q2 5、7p15-21、9q34和19q13上。 Abstract:The gene for human polypeptide chain elongation factor-1α(EEF1A)is a house-keeping gene which plays an important role in the process of protein synthesis.By means of comprehensive analysis in the database of Genbank,GDB and ect,we identify 4 retropseudogenes of EEF1A and finely localized to 4q25,7p15-21,9q34 and 19q13,respectively.     

A reference guide to drugs and dry mouth – 2nd edition

Xerostomia (dry mouth) is an uncomfortable and potentially harmful oral symptom which is usually caused by a decrease in the secretion rate of saliva (salivary gland hypofunction, or SGH). It is more prevalent in the elderly population, primarily due to their increased use of drugs and their susceptibility to disease. Many drugs and drug classes have been linked to xerostomia; the xerogenic effect increases when many drugs are taken concurrently. This Reference Guide to Drugs and Dry Mouth is designed to allow the reader to rapidly identify those pharmacologic agents which have the capacity to induce xerostomia and SGH. Xerogenic drugs can be found in 42 drug categories and 56 sub-categories. A guide to the management of drug-induced SGH and xerostomia is also provided.     

两种方法检测接种流行性出血热沙鼠肾细胞灭活疫苗后人体的中和抗体

本文应用空斑减少中和试验(PRNT)和细胞病变中和试验(cPENT)两种方法对出血热沙鼠肾细胞灭活疫苗扩大人体免疫后的血清进行中和抗体水平检测。根据两种方法对总计74人份的免疫后血清检测比较结果,两种方法检测的抗体阳转率和抗体水平(GMT)。CPENT法均高于PRNT法,经统计学处理均有显著性差异。不同免疫组的中和抗体水平比较结果,注射三针的阳转率(n=10,100％)高于两针组(n=10,20—30％);接种加氢氧化铝佐剂疫苗(n=13)较接种不加佐剂的两种疫苗(n=26)的抗体水平高,阳转率为92％—100％GMT为22—69;皮下途径(n=15)和肌肉途径(n=13)注射无明显差别,阳转率分别为87—93％和92—100％,GMT分别为29—46和22—61。以上结果进一步肯定沙鼠肾细胞疫苗的人体免疫性     

Finger-print patterns in parents of children with Down Syndrome

Finger-prints of the parents of thirty four Down children were compared with thirty four couples with two or more normal children without a family history of genetic problems. The parents with children affected by translocation Down Syndrome and those with mosaicism were excluded. A comparison of the figure distributions in each of the fingers of the two groups shows a different distribution. Parents of children affected by Down Syndrome occupy an intermediate position between the parents of normal children and the subjects affected by Down Syndrome. The total sum of values of A (arch), Lu (ulnar loop), Lt (radial loop) and W in each of the groups were also compared using a contingency table. A significant difference (p<0,05) was found between both groups. The differences are imputed to the variables A and L.     

Plant functional types – a strategic perspective

Abstract. This paper discusses the use of Plant Functional Types to describe vegetation types – from plant communities to formations – in order to understand the ecological constraints of plants and plant communities on a higher level of abstraction. The terminology around plant functional types, traits and strategies is in need of further clarification and unification. The use of the term plant functional type is recommended. We are in need of a total environmental framework in which, hierarchically or reticulately, plant functional types can be compared and interpreted.     

The role of infectious agents in sudden infant death syndrome

Abstract Epidemiological factors associated with susceptibility to respiratory infections are similar to those associated with Sudden Infant Death Syndrome. Here we review the evidence that respiratory pathogens might be involved in some cases of Sudden Infact Death Syndrome in the context of factors identified in epidemiological studies of cot deaths: the age range affected; mother's smoking; respiratory viral infections; immunisation status. Both laboratory and epidimiological evidence suggests that vulnerability of infants to infectious agents depends on interactions between genetic, developmental and environmental factors that contribute to colonisation by microorganisms, the inflammatory and specific immune responses and the infants' physiological responses to inflammatory mediators. A model is proposed to explain how microorganisms might trigger a series of events resulting in some of these unexpected deaths and discusses how the present recommendations regarding child care practices might help reduce the numbers of Sudden Infant Death Syndrome cases associated with infectious agents.     

一株广谱中和抗原性出血热病毒株的发现

一株分离自杭州市褐家鼠的出血热病毒Gou_3株的免疫血清对10株I型病毒的中和滴度除二株为160外均为320,而对4株Ⅱ型病毒的滴度为320—640,说明Gou_3株免疫血清对两型毒株中和效价大多数无差异或只差2倍,是一株中和抗原广谱的毒株。用I型和Ⅱ型毒株免疫血清对Gou_3株进行型别检定结果表明Gou_3株是Ⅱ型病毒。