两种不同的静脉注射方法对血管的影响

目的：比较两种给药方法对血管损伤的程度。方法：采用自身对照法进行注射泵（实验组）和手推（对照组）静脉注射,指压止血,光镜下观察局部血管及周围组织的变化。结果：注射泵指压止血时间较短,静脉炎发生率低（P〈0.01）,差异具有高度显著性。结论：注射中血流动力学的改变可加重血管的损伤,使指压止血时间延长。     

痘苗病毒毒力测定及其免疫血清的制备

目的测试痘苗病毒毒力,制备痘苗病毒免疫血清,为药物评价和病毒检测奠定基础。方法鸡胚绒毛尿囊膜培养痘苗病毒,测定病毒的TCID50和小鼠毒力。将痘苗病毒悬液稀释成100TCID550,0．2％福尔马林灭活,分别在0、7、14d以腹腔注射的方式免疫BALB／c小鼠,用IFA、IEA、ELISA方法评价血清的敏感性和特异性。结果痘苗病毒TCID50／0．05mL=1．8×10^4,小鼠LD50／0．2mL=10^6.8;制备的免疫血清经IFA法测定效价为1：320,IEA法测血清效价为1：160,ELISA测血清效价1：6400。结论确定的细胞和小鼠毒力将为药物测定提供基础比对数据;制备的痘苗病毒免疫血清具有高度的敏感性和特异性,可作为测试对照血清使用。     

新生儿接种流感嗜血杆菌乙型肝炎偶联疫苗（COMVAX^TM）的安全性和免疫效果研究

将出生时接种过重组酵母乙肝疫苗的131名HBsAg阴性母亲的新生儿,随机分为两组,一组接种COMVAX^TM,另一组接种单价乙肝疫苗和单价流感嗜血杆菌偶联疫苗,出生时第一针乙肝疫苗接种后,应用2,4,13月程序免疫,在2,4月免疫后,接种COMVAX^TM组和对照组新生儿中无一例发生重度副反应,接种COMVAX^TM组新生第一针免疫前（2月）和二针免后一个月（5月）的抗－HBs阳转率分别为53．73％和95．00％,抗全GMT分别为104．10和56．29,均与接种单价组无显著差异,第二针免疫后一个月接种COMVAX^TM组96．00％新生儿抗－PRP抗体达到长期保护临界值（1.0ug/ml)水平,而接种单价流感嗜血杆菌疫苗组新生儿为95．20％,结果表明,对于健康母亲所生的新生儿,接种COMVAX^TM疫苗,抗－HBs和抗－PRP抗体阳转率及滴度均不低于接种单价疫苗组。     

Evaluation on masks with exhaust valves and with exhaust holes from physiological and subjective responses

The purpose of this study was to compare the effects of wearing different kinds of masks on the ear canal temperature, heart rate, clothing microclimate, and subjective perception of discomfort. Ten subjects performed intermittent exercise on a treadmill while wearing the protective masks in a climatic chamber controlled at an air temperature of 25 degrees C and a relative humidity of 70%. Two types of mask-mask A, with exhaust valves and mask B, with exhaust holes-were used in the study. The results of this study indicated: (1) The subjects had a tendency toward lower maximum heart rate when wearing mask A than when wearing mask B. (2) Temperatures and absolute humidities (the outer surface of mask, the microclimate inside the mask, the chest wall skin and microclimate) of mask A were significantly lower than those of mask B. (3) The ear canal temperature increased significantly in mask B as compared to that in mask A. (4) The ear canal temperature showed significant augmentation along with increased temperature and humidity inside the mask microclimate. The mask microclimate temperature also affected significantly the chest microclimate temperature. (5) Mask A was rated significantly lower for perception of humidity, heat, breath resistance, tightness, unfitness, odor, fatigue, and offered less overall discomfort than mask B. (6) Subjective preference for mask A was higher. (7) The ratings of subjective overall discomfort showed significant augmentation along with increased wetness and fatigue. We discuss how the ventilation properties of masks A and B induce significantly different temperature and humidity in the microclimates of the masks and the heat loss of the body, which have profound influences on heart rate, thermal stress, and subjective perception of discomfort.     

Binding of divalent and trivalent cations with crotoxin and with its phospholipase and its non-catalytic subunits: effects on enzymatic activity and on the interaction of phospholipase component with phospholipids

We have studied the interaction of divalent and trivalent with a potent phospholipase A(2) neurotoxin, crotoxin, from Crotalus durissus terrificus venom. The pharmacological action of crotoxin requires dissociation of its catalytic subunit (component B) and of its non-enzymatic chaperone subunit (component A), then the binding of the phospholipase subunit to target sites on cellular membranes and finally phospholipid hydrolysis. In this report, we show that the phospholipase A(2) activity of crotoxin and of component B required Ca2+ and that other divalent cations (Sr2+, Cd2+ and Ba2+) and trivalent lanthanide ions are inhibitors. The lowest phospholipase A(2) activity was observed in the presence of Ba2+, which proved to be a competitive inhibitor of Ca2+. The binding of divalent cations and trivalent lanthanide ions to crotoxin and to its subunits has been examined by equilibrium dialysis and by spectrofluorimetric methods. We found that crotoxin binds two divalent cations per mole with different affinities; the site presenting the highest affinity (K(d) in the mM range) in involved in the activation (or inhibition) of the phospholipase A(2) activity and must therefore be located on component B, the other site (K(d) higher than 10 mM) is probably localized on component A and does not play any role in the catalytic activity of crotoxin. We also observed that crotoxin component B binds to vesicular and micellar phospholipids, even in the absence of divalent cations. The affinity of this interaction either does not change or else increases by an order of magnitude in the presence of divalent cations.     

Sequential events in calmodulin on binding with calcium and interaction with target enzymes

khe conformational and functional events in calmodulin (CaM) are disproportionate to the mean saturation by Ca2+. The enhancement of intrinsic tyrosine fluorescence closely follows the appearance of species CaM X Can greater than or equal to 1; the exposure of the hydrophobic patch at the surface of CaM coincides with the appearance of CaM X Can greater than or equal to 2. For the activation of four different target enzymes, i.e., brain phosphodiesterase and adenylate cyclase, red blood cell Ca,Mg-ATPase, and skeletal muscle phosphorylase b kinase, CaM X Can greater than or equal to 3 is required. The different enzymes have the same affinity for the active species. The direct interaction of CaM with Ca2+ and phosphorylase b kinase has been analyzed according to the theory of energy coupling: whereas the first two stoichiometric calcium-binding constants in the complex are not significantly different from those of free CaM, the third Ca2+ binds with an affinity at least 10(6)-fold higher to enzyme-bound CaM than to free CaM, which corresponds to a free energy coupling of -7 kcal/mol CaM. The similarities in the activation mechanism of different enzymes suggest the existence of one unique CaM-binding domain. The characteristics of the interaction between CaM and melittin, a small amphiphatic cytotoxin, led us to propose melittin as a model for such a CaM-binding domain.     

Impact of Piriformospora indica on tomato growth and on interaction with fungal and viral pathogens

Piriformospora indica is a root endophytic fungus with plant-promoting properties in numerous plant species and induces resistance against root and shoot pathogens in barley, wheat, and Arabidopsis. A study over several years showed that the endophyte P. indica colonised the roots of the most consumed vegetable crop tomato. P. indica improved the growth of tomato resulting in increased biomass of leaves by up to 20%. Limitation of disease severity caused by Verticillium dahliae by more than 30% was observed on tomato plants colonised by the endophyte. Further experiments were carried out in hydroponic cultures which are commonly used for the indoor production of tomatoes in central Europe. After adaptation of inoculation techniques (inoculum density, plant stage), it was shown that P. indica influences the concentration of Pepino mosaic virus in tomato shoots. The outcome of the interaction seems to be affected by light intensity. Most importantly, the endophyte increases tomato fruit biomass in hydroponic culture concerning fresh weight (up to 100%) and dry matter content (up to 20%). Hence, P. indica represents a suitable growth promoting endophyte for tomato which can be applied in production systems of this important vegetable plant not only in soil, but also in hydroponic cultures.     

Comments on diffusive and electrostatic effects with immobilized enzymes

Shuler, Aris &; Tsuchiya (1972) have recently considered the combined effects of diffusive resistance and electrostatic field on the rate of reaction catalyzed by an enzyme immobilized on a non-porous surface. They employed a potential distribution for the electrical double layer which is asymptotically valid when surface potential is small.The complete Gouy-Chapman solution, which is valid for higher surface potential, is employed here. Numerical values of the effectiveness factor calculated with this potential distribution agree very closely with the results of Shuler et al. for most cases. It is shown that the effectiveness factor can (i) attain magnitudes much greater than unity in physically realizable systems, (ii) approach the solution for “infinite” surface potential at reasonable values of surface charge density, and (iii) pass through a maximum as bulk substrate concentration is varied. This behavior leads to the existence of an optimum surface concentration for enzyme immobilized on a highly charged non-porous support such that the most effective catalytic action on a charged substrate is ensured. Finally, it is established that significant electrical and/or diffusive effects result in non-linear Lineweaver-Burk plots of reciprocal observed reaction velocity against reciprocal bulk substrate concentration. These non-linear plots cannot be interpreted in the same way as linear plots obtained when enzyme is unbound.     

Observations on Strokes and Cerebral Edema with Intracranial Tumours

Four patients who suffered strokes were found at autopsy to have intracranial tumours remote from the region responsible for the stroke, but the relevant cerebral white matter was swollen, pale yellow, and manifestly edematous. It is inferred from these observations that strokes in the presence of cerebral tumours may be caused by rapid fluctuations in the extent and intensity of the edema surrounding the cerebral tumour.A fifth patient is reported with recurrent strokes associated with a glioblastoma multiforme. He showed many dramatic remissions associated with treatment with adrenocorticotrophic hormone and equally prompt relapses when treatment was stopped. Similar cases in the literature are referred to. It is suggested that these hormones decrease the cerebral edema and thus produce the remissions.