[Rapid method for determination of chlordimeform residue in honey]

In the present work. TLC was used as a rapid method for determination of chlordimeform in honey. Twenty gram of sample was extracted by n-hexane in alkali solution, re-extracted by acidic aqueous solution, then hydrolyzed in NaOH solution for 10 min on boiling water bath. The hydrolyzed products were extracted by methylene chloride. After passing through the Na2SO4 column for dehydration, the methylene chloride should be evaporated to less than 70 degrees C to 0.5 mL spot 50 microL sample solution on the silica gel plate, develop the plate about 8 cm from the surface of developing solvent V(benzene):V(chloroform):V(ethyl acetate) = 5:5:1. The plate was kept in the atmosphere (NaNO2 + HCl) for 10 min and 5% N-(1-naphthyl) ethylendiamine dihydrochloride was sprayed on it. Put it into a dark room for 20 min and then observe and estimate the amount of chlordimeform in the sample. The limit of determination is 10 ng. The experiment could be completed in 3 h for a sample without large equipment and special reagent.

The role of p38 MAP kinase in TGF-beta1-induced signal transduction in human neutrophils

Transforming growth factor-beta 1 (TGF-beta 1) is the strongest chemoattractant yet described for human neutrophils. It activates neither phospholipase C nor phospholipase D. It does not induce rises in intracellular calcium, degranulation, or superoxide production. The signaling pathways utilized by TGF-beta 1 are largely unknown. This report demonstrates that TGF-beta 1 activates p38 MAP kinase. The kinase inhibitor SB203580 blocks the chemotactic responses as well as actin polymerization induced by TGF-beta 1. Potential cellular targets of the p38 MAP kinase pathway which could mediate these function are discussed.

Promoting health: perspectives from ethnic elderly women

The purpose of this study was to investigate health-promoting measures used by ethnic elderly women. Within the context of this goal, two major research questions were asked: (a) What measures were used by the ethnic elderly women to promote their health? (b) What were the facilitators and barriers with respect to health promotion in this sample? A convenient and purposive sample consisted of 30 elderly women from three ethnic backgrounds--African American, Chinese American, and European American--who reside in an urban area of the northeastern part of the United States. Data were collected through in-depth interviews and survey questionnaires. Content and statistical analyses were employed. Participants identified measures, facilitators, and barriers in relation to promoting their health. These findings provide insight for community health nursing practice.

[Study on the adhesion of an endemic strain of Streptococcus mutans serotype C to acquired pellicle. II. Isolation and extraction of adhesins of an endemic strain of Streptococcus mutans serotype C]

Surface proteins of S. mutans WD9463 A(c) were separated by DEAE-Sephadex A25 Chromatography and Sepharose C1-6B Chromatography. The adhesins were distinguished by bacterial adhesin inhibition experiment and were identified by PAGE, SDS-PAGE, IEP-PAGE, immunol diffusion test, GTF activity test and annalization of the sorts of amino acid. The results showed P1, two proteins with molecular weight of 117 kD and 127 kD and two proteins with GTF activity could inhibit the adhesion effectively. On the other hand, another kind of GTF could improve the adhesion of the strain. These indicated that S. mutans may be many kinds of adhesins.

[Study on the adhesion of an endemic strain of Streptococcus mutans serotype C to acquired pellicle. I. A comparison of the methods to extract adhesins from Streptococcus mutans]

The adhesins of S. mutans serotype c endemic strain WD9463A were extracted from culture superant by cold ethol precipitation, or were extracted from cell surface by 0.5 mol/L phosphate buffer, 6 mol/L urea or 2% SDS solution. The composition and adhesive activities of the extracts were compared by SDS-PAGE and bacterial adhesion inhibition experiments. The results showed that the protein composition of the four extracts were similar, and all extracts inhibited the adhesion of the endemic strain dramatically. It indicates that four methods can be used to extract adhesins of S. mutans, but extracting adhesins from culture superant is better than the others.

Characterization of a Drosophila proximal-sequence-element-binding protein involved in transcription of small nuclear RNA genes

In a wide variety of eukaryotic organisms, transcription of small nuclear RNA (snRNA) genes is dependent upon a proximal sequence element (PSE) located upstream of position -40 relative to the transcription start site. There is little or no existent knowledge concerning the PSE-binding proteins of organisms other than human. Here, we report the purification of a fraction enriched in the Drosophila melanogaster PSE-binding protein (DmPBP). DmPBP forms a highly specific complex with the PSE. The protein stimulates transcription from the U1 gene promoter by RNA polymerase II and from the U6 gene promoter by RNA polymerase III in Drosophila nuclear extracts, and activation is dependent upon the presence of a PSE. The molecular mass of native DmPBP as measured by gel-filtration chromatography is 375 kDa. Two polypeptides (apparent molecular masses 59 kDa and 61 kDa) appear to be in close contact with the DNA in that they can be very efficiently and specifically crosslinked to the PSE sequence by ultraviolet irradiation.

LSP1 is the major substrate for mitogen-activated protein kinase-activated protein kinase 2 in human neutrophils

In intact cells, mitogen-activated protein kinase-activated protein (MAPKAP) kinase 2 is rapidly activated by various cytokines, stresses, and chemotactic factors. The small heat shock protein p27 has been shown to be a substrate for MAPKAP kinase 2. Recently, we identified a novel substrate, designated p60, for MAPKAP kinase 2 in human neutrophils (Zu, Y.-L., Ai, Y., Gilchrist, A., Labadia, M. E., Sha'afi, R. I., and Huang, C.-K. (1996) Blood 87, 5287-5296). To further understand the signaling pathway of MAPKAP kinase 2, we have purified p60 from a heat-treated neutrophil lysate by DEAE-cellulose chromatography and SDS-polyacrylamide gel electrophoresis. Microsequencing of five peptides derived from purified p60 indicates that p60 is lymphocyte-specific protein 1 (LSP1). Furthermore antibodies specific for human and mouse LSP1 react with human and mouse p60. The sequence of human LSP1 indicates two serine residues at positions 204 and 252 as potential phosphorylation sites. The amino acid sequences surrounding these two sites are in agreement with the consensus sequence (Xaa-Xaa-Hyd-Xaa-Arg-Xaa-Xaa-Ser-Xaa-Xaa) for phosphorylation by MAPKAP kinase 2. Both serine residues in human LSP1 and the corresponding conserved serine residues in mouse LSP1 are in the basic C-terminal F-actin binding domain. Various fusion proteins of wild type and truncated mouse LSP1 with glutathione S-transferase were tested for their capacity to be phosphorylated by MAPKAP kinase 2. The results indicate that LSP1 is a substrate for MAPKAP kinase 2 in vitro and that the phosphorylation sites are located in the basic C-terminal domain of LSP1. Because both the small heat shock proteins and LSP1 are F-actin binding proteins, these results suggest a role for MAPKAP kinase 2 in the regulation of cytoskeletal structure or function.

Escherichia coli RNase T functions in vivo as a dimer dependent on cysteine 168

It was shown that Cys-168 is required for RNase T function and thermostability and that its hydrophobic properties are important for this role (Li, Z., Zhan, L., and Deutscher, M. P. (1996) J. Biol Chem. 271, 1127-1132). To understand the molecular basis for these findings, further studies of Cys-168 and RNase T structure were carried out. Treatment of RNase T with the sulfhydryl-modifying agent 5,5'-dithiobis-(2-nitrobenzoic acid) leads not only to inactivation, but also to monomerization of the protein. Similarly, specifically converting Cys-168 to either serine or asparagine leads to loss of activity and to monomer formation at 37 degrees C. However, at 10 degrees C the serine mutant remains as a dimer and retains full RNase T activity, whereas the asparagine derivative shows only a low level of activity and of dimer formation. These data show a strong correlation between activity and the dimer form of RNase T. The importance of dimer formation was also shown in vivo using genetic studies. An inactive mutant of RNase T, termed HA2, which exists as a dimer at 37 degrees C in vitro, completely suppresses endogenous RNase T activity in vivo and in vitro when introduced into a RNase T+ cell on a multicopy phagemid, most likely as a consequence of inactive heterodimer formation. Introduction of the HA2 gene on a single-copy plasmid, as expected, leads to a proportionally smaller effect on endogenous activity. The dominant negative effect displayed by the HA2 protein can be relieved by an additional mutation in HA2 RNase T that abolishes its ability to dimerize. An inactive mutant asparagine derivative of Cys-168, which also does not dimerize, also shows little of the dominant negative phenotype. Thus, these data demonstrate that RNase T dimerizes in vivo, that the dimer form is required for RNase T activity, and that Cys-168 is needed for dimerization of the enzyme.

The role of individual cysteine residues in the activity of Escherichia coli RNase T

Escherichia coli RNase T, which is responsible for the 3' processing and end-turnover of tRNA and the maturation of 5 S RNA, is extremely sensitive to sulfhydryl reagents and to oxidation, suggesting a role for cysteine residues in its activity. Titration of homogeneous RNase T with 5,5'-dithiobis-(2-nitrobenzoic acid) revealed that the 4 cysteine residues present in each of the two protein subunits are in a reduced form and that 1 or 2 of them are important for activity. To identify these residue(s), each of the cysteines in RNase T was changed individually to either serine or alanine. The serine mutant at position 168 is greatly reduced in RNase T activity both in vivo and in vitro; likewise, the serine mutant at position 112 and the alanine mutants at positions 112 and 168 also display decreased RNase T activity. Mutations at the other cysteine positions show little or no change. Kinetic analyses of the mutant enzymes showed that the Km values of C168S and C168A are increased considerably, whereas their Vmax values are reduced only slightly compared to the wild type enzyme. The other mutant enzymes are little changed. Additional amino acid replacements at position 168 showed that the in vivo and in vitro activities of RNase T are in the order Cys approximately Val > Ala >> Ser >> Asn approximately Asp, which closely follows the relative hydrophobicity of these amino acid residues. However, the affinity for tRNA, determined by fluorescence quenching, is not altered in C168S, suggesting that Cys-168 is not directly involved in substrate binding. Interestingly, proteins altered at position 168 showed increased temperature sensitivity as the residue at that position became less hydrophobic. These data indicate that Cys-168 contributes a hydrophobic group that influences the structure and ultimately the catalytic activity of RNase T.

[Molecular cloning of the adherence gene cluster from uropathogenic Escherichia coli and preparation of its antisera]

A genomic library of the uropathogenic E. coli J96 was constructed by using cosmid pHC79 as cloning vector. Two positive recombination cosmids which could express the adherence characters were acquired. From both cosmids a EcoRI fragment was subcloned into the vector pACYC184 by shot-gun method. Three colonies were found which exhibited MRHA and production of P Pili. One of them, pCT10/E. coli K-12 P678-54, was about 14.6 kb and was used to prepare the antisera. After absorption with pACYC184/E. coli K-12 P678-54 for three times, the antisera were revealed specific against the adherence gene cluster of uropathogenic E. coli by the SDS-PAGE and Western blotting of the P pilus crude extracts and the hemagglutination inhibition test.

The development of an instrument to measure self-consistency

The maintenance of self-consistency is a task that engages elderly people, and it can be viewed as an indicator of how well a person can cope with stress in the ageing process. However, there is no reliable and valid instrument to date that measures this phenomenon. To help elderly people to accomplish the task warrants the necessity to develop an instrument to measure self-consistency. The purpose of this study was to develop an instrument to measure self-consistency in elderly people with chronic conditions. The Self-Consistency Scale (SCS) was designed and administered to hearing-impaired elderly people (n = 130) in the north-east part of the USA. Psychometric properties of the SCS were evaluated and the results indicated a promising psychometric integrity. The obtained alpha coefficient for the SCS total scale was 0.89, with a score range of 51-104 and a mean total score of 85.10 (SD = 11.04). Convergent validity of the SCS was established by correlating the SCS to a Visual Analogue Scale--A Sense of Self (VAS), r = 0.60 (P < 0.01). Divergent validity with the Geriatric Depression Scale (GDS) was established, r = -0.57 (P < 0.01). Maximum likelihood factor analysis with oblimin rotation resulted in a two-factor solution: Factor I, self-knowledge; and Factor II, stability of self-concept.

Quality of life: conceptual and measurement issues

Nursing as a human science is concerned with the experiences of human beings in relation to health and illness matters. Human experiences are shaped by history, relationships, politics, social structures, gender and culture. Nurses are concerned with how these perspectives shape the actions and reactions of human beings. Nursing seeks to maximize clients' strengths, assets and potential, and to contribute to their quality of life. The concept of quality of life will be discussed in this paper. The first section will present a historical perspective of the concept. The second part synthesizes conceptual and measurement issues from a review of the literature. Finally, dimensions of this concept are defined and approaches to operationalize this concept are suggested.