Epitope analysis of the CS3 fimbrial subunit of human enterotoxigenic Escherichia coli and the construction of novel CS3::ST and CS3::LT-B immunogens

Enterotoxigenic E. coli (ETEC) are the major cause of traveler's diarrhoea and the CS3 fimbriae/fibrillae are expressed by most strains bearing the colonization factor CFA/II. The cstAH gene cluster determining CS3 biosynthesis has been previously cloned and sequenced and it has been shown that cstH encodes the major fimbrial subunit and cstA-G encode an assembly cassette. In the work described here we have sought to define the surface exposed domains on CS3 and to manipulate them so that CS3 can be used as a means of expressing foreign antigenic determinants on the bacterial surface. Using a panel of 21 monoclonal antibodies, which we have used in western blotting, immunofluorescence microscopy and colony blotting, together with computer predictions, we have identified three domains within CstH. Two of these sites were permissive for insertion and we have introduced, in-frame, either an epitope from the B subunit of LT (heat labile toxin) or the entire coding sequence of mature ST (heat stable toxin) to construct hybrid proteins. These proteins could be assembled into hybrid fimbriae which could be recognized by antibodies to both CS3 and the foreign epitope as shown by immunofluorescence microscopy and colony blotting. The immunogenicity of the constructs has been evaluated following both oral and intraperitoneal immunization of mice with the attenuated Salmonella typhimurium strain G30 harbouring the hybrid cst operons. Although plasmid stability is currently a problem, these experiments showed that antibodies to both the carrier and the foreign epitope were generated.     

植物促生菌CS1·CS2和CC9对盐碱地种植水稻的促生效果

[目的]探讨植物促生菌CS1、CS2和CC9对盐碱地种植水稻的促生效果.[方法]分别以促生菌CS1、CS2、CC9以及CS1+CS2、CC9+CS2组合菌处理种植在盐碱地上的水稻,收获水稻时分别对水稻的穗长、穗重、穗粒数、秕子数、株高及水稻丛重进行了测量.[结果]菌株CS2和CC9能够有效促进水稻生长和籽粒形成,提高水稻产量.与对照相比,CS2、CC9和CS2+CC9处理的株高分别增加了6.28%、6.32%和7.90%,穗长分别增加9.80%、16.00%和8.40%.其中,单独使用CC9菌株处理的效果最好,与对照相比,穗长增加了15.85%,穗籽粒数增加了15.82%,穗重增加了50.67%,丛重增加了31.00%.[结论]为生产实践提供了理论依据.     

The influence of different freezing procedures and different cryoprotective agents on the immunological capacity of frozen-stored lymphocytes

The influence of a series of factors on the frozen storage of lymphocytes was investigated. The cells were frozen using different freezing programmes, using the cryoprotectants dimethyl sulphoxide and glycerol in different concentrations in the freezing medium, and with variations in the period of exposure of cells to cryoprotectants before freezing and after thawing. Cell viability was evaluated by quantitative measurements of the cell-mediated immune response after stimulation with phytohemagglutinin, pokeweed mitogen, concanavalin A, and allogenic cells in mixed lymphocyte cultures. The factors investigated were found to have an important effect on the immune response, so that careful investigation and exact specification of the freezing system are necessary before frozen cells are used in blast-transformation tests. The best freezing programme had a duration of approximately 40 min with a smooth progression through the temperature range where phase transition takes place. The optimum dimethyl sulphoxide concentration in this programme was 8--10%. Dimethyl sulphoxide had no toxic effect on the cells, and no equilibration period was necessary prior to freezing. An equilibration period of 15 min with 10% glycerol was even better than the optimum programme with dimethyl sulphoxide.     

Two siblings of type 3 GM1 gangliosidosis with different clinical features and different ages of onset

We experienced two siblings of type 3 GM1 gangliosidosis. A 33-year-old woman developed dysarthria, dysbasia and bradykinesia at around the age of 30. Her 28-year-old brother showed locomotor retardation and skeletal deformity in infancy. He lost the ability to stand walk at childhood, and developed progressive dystonia. The major neurologic manifestations were parkinsonian symptoms in the elder sister, and progressive dystonia in her brother. Both had markedly reduced beta-galactosidase activity in peripheral blood lymphocyte and were diagnosed as having type 3 GM1 gangliosidosis. Gene analysis revealed that these patients were homozygotes of the adult type mutant gene. The two siblings are unique in that the clinical manifestations and the age of onset of symptoms differed markedly between them despite the same mutant gene in both cases.     

Effects of mixed rare earth fertilizer on yield and nutrient quality of leafy vegetables during different seasons

Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons(spring and autumn), the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy vegetables were studied to provide a theoretical basis for the application of mixed rare earth fertilizer in agriculture. Results showed a seasonal difference in the nutrient quality of Chinese cabbage and rape. For crops planted in autumn, the soluble sugar and vitamin C content were higher, the titratable acid and nitrate content were lower, and the sugar acid ratio was higher relative to crops planted in spring. Mixed rare earth treatments promoted growth of both crops during both seasons. The plot yield, stem and leaf fresh and dry matter weight, and dry and fresh ratio increased. These increases for Chinese cabbage were greater in autumn than in spring while for rape, the increases were greater in spring than autumn. The soluble sugar content, titratable acid content and sugar acid ratio were increased and the nitrate content decreased, in autumn the effects were more obvious than in spring. In spring, the vitamin C content was increased, and the increase was greater for Chinese cabbage than rape. In autumn, the vitamin C content decreased, and the decrease was greater for rape than Chinese cabbage. At the same time, the content of heavy metals such as Cu, Zn, Cd, Pb and Ni in stems and leaves decreased. This decrease was greater in spring for Chinese cabbage and in autumn for rape.     

Effects of four different methods of sampling arterial blood and storage time on gas tensions and shunt calculation in the 100% oxygen test

At the present time, plastic syringes are most commonly used for collecting arterial blood. The oxygen tension of the arterial blood (Pa,O2) in these syringes may fall. We studied the effect of the type of syringe, metabolism, and storage time on the arterial oxygen pressures measured and on the pulmonary shunt calculated. In 10 patients, 2-3 h after aortacoronary bypass surgery, a 100% oxygen test was performed. Four arterial blood gas samples were withdrawn from each patient in random order, two in glass syringes and two in plastic syringes. One glass and one plastic syringe were stored at room temperature (RT), and the others were stored in ice-water (IW). Each sample was analysed as soon as possible, and repeated 15, 30, 60 and 120 min after sampling. The Pa,O2 measurement in blood in the glass syringe in IW measured as soon as possible after sampling was considered the "gold standard". Pulmonary shunt calculations were performed using the results of the various blood gas analyses. Compared with the "gold standard", all of the other methods showed significant deterioration in the Pa,O2 measurement. The effect due to diffusion was 0.05 kPa x min(-1), and that due to metabolism 0.11 kPa x min(-1). The Pa,O2 in the glass syringes stored in IW remained stable with time. The pulmonary shunt was significantly overestimated when the "gold standard" blood gas results were not used (range 0.8-9.9%). Glass (not plastic) syringes should be used in the 100% oxygen test. The syringe should be cooled immediately, even when the sample is analysed as soon as possible.     

Effect of different factors on the quality of raw pellets

Belgorod Branch of the Mekhanobchermet Institute. Lebedin Mining-Concentration Combine. Translated from Metallurg, No. 2, pp. 28–29, February, 1989.     

Effects of different ligands on luminescence properties of LaF3：Nd nanoparticles

A series of neodymium-doped lanthanum fluoride nanoparticles(NPs) were synthesized with hydrothermal method,and the effects of several ligands on the luminescence properties of the NPs were investigated.The X-ray diffraction(XRD) results indicated that the crystal phases of the modified NPs coincided with the standard spectrum.The transmission electron microscopy(TEM) showed that the samples were of similar size,shape and dispersibility.The infrared spectra suggested that the content of -OH groups as quenchers on the NPs surfaces decreased after modification.Compared with NPs modified by branched paraffin ligands,NPs conjugating ring-contained modifiers had less quenching effect and possessed stronger fluorescence intensity and longer fluorescence lifetime.     

菌式穿孔对毛管质量影响的研究

通过与曼氏穿孔机的对比，指出了菌式穿孔机轧辊形状及其空间布置的特点.通过试验研究和对穿孔过程的分析，论述了菌式穿孔对改善毛管内外表面质量、壁厚均匀性及提高高合金材料可穿性等优越性的机制，用轧卡试验的方法进行了验证.同时提出菌式穿孔温升对毛管质量的影响.     

Racial differences in incidence, outcome, and quality of life for African-Americans on hemodialysis

African-Americans are the fastest growing racial minority with end-stage renal disease (ESRD) in the United States. Although comprising < 15% of the US population, African-Americans comprise approximately 31% of the ESRD population. African-Americans are approximately 7 years younger than their white counterparts with ESRD. Surprisingly, although African-Americans systematically receive less dialysis than whites, their survival with ESRD is greatly improved. This improved survival with ESRD is accompanied by an improved quality of life for African-Americans. In this review, we will examine the reasons why African-Americans have an excessive incidence of selective diseases that culminate in ESRD. Furthermore, we will judge several hypotheses that may account for the improved survival enjoyed by African-Americans with ESRD. We contend that research targeted to clarify the basis for these differences between African-Americans and whites with ESRD will improve the outcomes for both populations.     

The World Health Organization WHOQOL-100: Tests of the universality of quality of life in 15 different cultural groups worldwide.

The World Health Organization Quality of Life assessment (WHOQOL-100) was developed simultaneously across 15 international field centers and includes 24 facets relating to quality of life, which are grouped into 4 larger domains: physical, psychological, social relationships, and environment. It also includes 1 facet examining overall quality of life and general health perceptions. This article examines the extent to which the WHOQOL-100 assesses quality of life perceptions in different cultures and whether it is structurally comparable in these cultures. Regression analysis showed all 4 domains to be important in assessing quality of life in each of the 15 centers. Structural equation modeling suggested further support for the proposal that there are universal facets and domains that are cross-culturally important in determining quality of life and suggested that the ordering of facets within domains is comparable across cultures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of hand dominance and sleep side preference on hemodialysis vascular access survival

We examined the effects of hand dominance and the patients' stated preference of the sleeping position on the survival of vascular accesses for hemodialysis in different locations. Analysis was made of vascular access survival times after 1, 126 vascular access surgeries performed between January 1, 1989, and December 31, 1994. We found that hand dominance and access site were not related to any survival differences in patients with autogenous fistulas, but thigh grafts on both sides had greater survival than arm grafts. The preferential side for sleeping similarly did not seem to affect access survival, but patients who stated a sleep preference on the side opposite their vascular graft tended to have longer access survival time.     

Effects of hypervolemia on interdialytic hemodynamics and blood pressure control in hemodialysis patients

The influence of hypervolemia on hemodynamics and interdialytic blood pressure, as well as in relation to vascular compliance, was investigated in 10 hemodialysis patients who were not receiving vasoactive medication. All subjects were studied during a relative normovolemic interdialytic period (from 1 kg below dry weight postdialytic until dry weight predialytic) and a hypervolemic interdialytic period (from 1 kg above dry weight postdialytic until 3 kg above dry weight predialytic). Interdialytic blood pressure was measured with an ambulatory blood pressure monitor. Cardiac output was echographically measured and total peripheral resistance calculated postdialytic, mid-interdialytic, and predialytic. At the same time, a blood sample was drawn for analyzing vasoactive hormones, sodium, and hematocrit. In all patients, ideal dry weight was estimated by echography of the caval vein. Arterial and venous compliance were measured with an ultrasound vessel wall movement detector system and a strain-gauge plethysmograph. After fluid load, an increase in intravascular volume, an increase in caval vein diameter and cardiac output, and a decrease in peripheral resistance was observed. No significant influence of a 3-L fluid load was found on interdialytic blood pressure course (153+/-24 mm Hg/90+/-19 mm Hg in the hypervolemic period and 146+/-27 mm Hg/89+/-22 mm Hg in the normovolemic period). Sodium and osmolality were similar in the hypervolemic and normovolemic interdialytic periods. After fluid load, a decrease in arginine vasopressin and angiotensin II was observed, which probably contributed to the decreased systemic vascular resistance. Catecholamines were not influenced by fluid load, but increased during the interdialytic period, suggesting accumulation after dialysis. Three of the 10 patients had higher systolic but not diastolic blood pressures after fluid load (159+/-13 mm Hg/81+/-22 mm Hg in the hypervolemic period and 135+/-16 mm Hg/81+/-22 mm Hg in the normovolemic period). No correlation could be found between arterial or venous compliance and blood pressure changes. We concluded that a 3-L interdialytic fluid load does not result in higher blood pressure in most hemodialysis patients.     

Effects of type of input and type of processing on recall hypermnesia.

120 undergraduates participated in 1 of 6 conditions representing 2 types of input (words, pictures) and 3 types of initial processing, including imagery (generate object imagery or real-world imagery), semantic (rate pleasantness or form a verbal association), and physical (rate complexity or judge the presence of a feature). After viewing 70 items, Ss attempted to recall them 4 times. Except for physical processing of words, the number of items correctly recalled improved over trials, demonstrating hypermnesia. Intrusions increased over trials in most conditions and appeared later within a trial for words than for pictures. Of 5 alternative accounts of hypermnesia, results favor the sensory/semantic model of memory coding. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of locus of control and differential analogue interview procedures on the perceived therapeutic relationship.

After administration of Rotter's Locus of Control Scale, 32 male college students were exposed to either a modified desensitization or a semistructured interview technique. The 2 male E-therapists participated in both conditions. Afterward each S completed the Leary Interpersonal Check List, indicating his perceptions of his E-therapist. Results show that E-therapists are perceived differently depending on the technique used, and that perceptual differences are related to locus of control. Findings are interpreted within a cognitive theoretical framework. (41 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of different storage temperatures, sample collection procedures and immunoassay methods on osteocalcin measurement

The apparent instability of measured osteocalcin has been reported as method-dependent and related to preanalytical variables such as storage temperature, and the use of anticoagulants and protease inhibitors. The aim of this study was to determine a sample collection procedure which minimised osteocalcin degradation. Blood samples from five normal individuals were collected with or without anticoagulants and protease inhibitors (heparin, EDTA, or heparin and aprotinin) and stored at 4 degrees C, -20 degrees C or -70 degrees C for up to 7 days, 28 days and 90 days respectively. Osteocalcin was measured by both a monoclonal EIA specific for intact osteocalcin and a bovine polyclonal RIA. Osteocalcin concentrations in serum and EDTA-treated samples significantly decreased by 40% (P < 0.001) with the ELISA and 72% (P < 0.001) with the RIA after 7 days storage at 4 degrees C. Similar falls were documented in these samples when stored at -20 degrees C and -70 degrees C and measured by the ELISA. Minimal changes in osteocalcin immunoreactivity were observed in either assay when heparin-treated plasma with or without aprotinin was stored at -20 degrees C or -70 degrees C for up to 90 days. The apparent instability of measured osteocalcin can be minimised using these conditions.     

添加剂对电锌表面质量的影响

研究动物胶、十二烷基磺酸钠、硫脲等作为添加剂对阴极锌表面质量的影响．通过目测和照片对其影响效果进行了评价．结果表明：动物胶和十二烷基磺酸钠的效果相似,硫脲具有抗氧化作用,起到了比较好的效果,有望成为锌电积中的新添加剂．     

Thermomechanical properties of molds based on different binders and casting quality

The thermomechanical properties of foundry sand are analyzed. The thermal and dynamic action of the melt on the mold wall during the casting and solidification of metal is considered, along with its role in the formation of surface defects. The influence of the heating time on the deformation of common types of foundry sand is determined by simulating industrial ingot casting. The deformability of the foundry sand is related to the defects that form on the ingots and the pliability of the sand. Measures are proposed to prevent surface defects. Scabs, gaps, and hot buildup on castings may be attributed to deformational changes and disintegration in the surface layers of the foundry sand. In terms of surface-defect prevention and environmental protection, sodium-silicate foundry sand and phosphate sands are the best.