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61.
As health care comes under mounting pressure to reduce costs, organizations are restructuring. Delivery systems are changing. As layoffs occur and changes are made in numbers and responsibilities of managers, supervisors find themselves in dramatically changing roles. Job security has become as illusory in health care as elsewhere. Morale among health workers is sagging, and motivational concerns are increasing. The supervisor has been put in the position of having to do more with less and to do it in the face of demoralized forces. The paradigms that were once operational are shifting, and the evolving role of the health care supervisor suggests that a completely new set of paradigms is taking over that suggests the supervisor's future security lies in the ability to learn new things and to shift and change with the environment.  相似文献   
62.
In these days of reengineering health care and downsizing many health organizations, a great deal of attention is given to means of reducing the work force. Not nearly as much attention is paid to the survivors of a staff reduction and the problems that arise in the wake of a generally demotivating activity. However, it is the survivors--those who remain after downsizing--that will have the greatest influence on the organization's future performance. Therefore, the survivors must be remotivated and reinvigorated. Such is the task of surviving supervisors and middle managers, and their primary tools are communication, education, and people-centered management.  相似文献   
63.
Summary As determined by a colorimetric assay measuring parent compounds plus ether-extractable, nitroso-containing metabolites, N,N-bis(2-chloroethyl)-N-nitrosourea (BCNU) disappeared more rapidly than N-(2-chloroethyl)-N cyclohexyl-N-nitrosourea (CCNU) and N-(2-chloroethyl)-N-(4-transmethylcyclohexyl)-N-nitrosourea (MeCCNU) and their products from the tissues of mice injected IV. Assay of selected samples by high-pressure liquid chromatography revealed that the colorimetric assay for BCNU was specific in that the two assays gave equivalent results. Following IV-injections of CCNU and MeCCNU, however, levels of the parent compounds decreased much more rapidly than the total, color-producing material.Of seven tissues, the largest Cxt values for BCNU, as determined by the colorimetric assay, were noted for blood (442 g-min/ml) and large intestine (285 g-min/g). Liver (29 g-min/g) had the lowest Cxt value, reflecting rapid metabolism of the compound by this organ. Color-producing material related to CCNU disappeared from the solid tissues of mice in a manner generally parallel to that for blood. Of the Cxt values for this compound and its products, those for lung (1753 g-equivalents-min/g), kidney (1633 g-equivalents-min/g), and small intestine (1557 g-equivalents-min/g) were highest. Consistent with its slower rate of metabolism, MeCCNU and its color-producing metabolites remained in most tissues of mice for 12 h following injection. Except for brain (1434 g-equivalents-min/g), Cxt values for this nitrosourea and its metabolites in tissues were higher than those of blood (5485 g-equivalents-min/ml), with kidney (15,324 g-equivalents-min/g), liver (12,921 g-equivalents-min/g), and large intestine (11,501 g-equivalents-min/g) being highest. For each nitrosourea, a fair correlation was observed between the Cxt values for tissues and the toxic and/or antitumor effects at those sites.  相似文献   
64.
Monolayers of dipalmitoyl phosphatidylcholine have been transferred from an air-water interface to single-crystal silicon wafers previously alkylated with octadecyltrichlorosilane. By using synchrotron radiation it has been found possible to observe diffraction by single-crystal regions of these monolayers with negligible background scattering from the solid substrate. In one series of experiments, diffraction signals at Bragg spacings of 0.4247 ± 0.0002 nm and 0.4253 ± 0.0002 nm were observed. The supported phospholipid monolayer crystals show remarkably high in-plane order: the positional coherence length is at least 500 nm and the orientational order is better than 0.01°. Preliminary temperature scans were carried out. The data reveal the existence of a phase transition at about 65°C.  相似文献   
65.
As a staff function, human resources is organized as a service activity. Service activities render no patient care; they do not advance the work of the organization. However, they support the performance of the organization's work and in a practical sense become necessary. For example, if a pure service, such as building maintenance, did not exist, the facility's physical plant would gradually self-destruct. Similarly, without human resources to see to the maintenance of the work force, the overall suitability and capability of that work force will steadily erode. Recognize human resources for what it is--an essential service function required to help the organization run as efficiently as possible. Learn what the HR department does, and especially learn why the department does what it does. Provide input to the human resource department. Forge a continuing working relationship with the HR department, making it clear that you expect service from this essential service department. Challenge the HR department to do more, to do better, and to continually improve service--and put the human resource department to work for you and your employees.  相似文献   
66.
The Workshop on Approaches to Evaluating the Toxicity and Carcinogenicity of Man-Made Fibers (MMF) was held in Durham, North Carolina, on November 11-13, 1991. The goal of the workshop was to reach a consensus, or to determine the extent to which a consensus existed, in two areas. Participants were asked to identify scientifically sound approaches for evaluating the toxicity and carcinogenicity of man-made fibers based on today's science and to determine research appropriate for study during the next 5 years that can provide an improved scientific basis for future revisions of approaches used to evaluate man-made fiber toxicity and carcinogenicity. During the first day, a series of "state of knowledge" presentations were made to provide all participants with a common data base from which to interact and discuss scientific issues. The workshop participants were assigned to one of four discussion groups, which met separately in three half-day sessions following the first day of presentations. All groups discussed the same topics: exposure assessment, hazard identification, and dose-response information needed to integrate to characterize risk in the first session; approaches to obtaining the needed information in the second session; and recommended approaches and guidelines for evaluating the toxicity and carcinogenicity of MMF and research needs in the third session. The workshop participants reconvened as a whole after each discussion session, and one member from each group reported the group's conclusions. A closure period was also included at the end of the workshop for review and discussion of items that had been considered during the workshop. The primary conclusions reached were the following: -All fiber types capable of depositing in the thorax are not alike in their pathogenic potential. -Only fiber samples with dimensions similar to those to which humans can inhale should be tested. -A complete characterization (i.e., dimensions, fiber number, mass, and aerodynamic diameter) of the fiber aerosol and retained dose is essential. -Appropriate aerosol generation methods must be used for inhalation studies in order to preserve fiber lengths. -A tiered approach to toxicity evaluation is recommended that includes: 1. In vitro screening for durability, surface properties, cytotoxicity, and similar properties, etc; 2. Short-term inhalation or other in vivo studies; 3. That chronic inhalation studies are the "gold standard" (i.e., provide most appropriate data for risk characterization). -The rat is the most appropriate species for inhalation studies. -In chronic inhalation studies, animals should be retained to at least 20% survival after 2-year exposure. -Serial lung burden analyses are an essential component of inhalation studies and are essential for understanding exposure-dose-response relationships. -Studies oriented to understanding mechanisms of toxicity and carcinogenicity are important adjuncts to traditional toxicity studies. -Histopathological analyses of tissues of the respiratory tract represent primary endpoints for evaluating effects of inhaled fibers. Major effects include pulmonary fibrosis, lung tumors, and mesotheliomas. Experimental tissues should be archived for future studies; wherever possible, handling and preservation of tissues should be done in a way that maximizes their future use in mechanistic studies. -Potential human exposures throughout the entire life-cycle of the fiber must be considered and fibrous material for toxicologic studies prepared accordingly. -Intracavity studies are inappropriate for risk characterization but can play a useful screening role in assessing fiber toxicity.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
67.
OBJECTIVE: Homozygosity for variants of the methylenetetrahydrofolate reductase (MTHFR) gene is associated with decreased risk for colorectal cancer. We have investigated the relationships between two variants of the MTHFR gene (C677T and A1298C) and blood folate, homocysteine, and genomic stability (strand breakage, misincorporated uracil, and global cytosine methylation in lymphocytes) in a study of 199 subjects. RESULTS: The frequencies of homozygosity for the C677T and A1298C variants of the MTHFR gene were 12.6% and 14.6%, respectively. Plasma homocysteine, folate, vitamin B12, 5-methyltetrahydrofolate, and RBC folate were determined in the C677T genotypes. Plasma folate was significantly lower (P < 0.001) in the homozygous variants (6.7 +/- 0.6 ng/mL) compared with wild-types (8.8 +/- 0.4 ng/mL) and heterozygotes (9.1 +/- 0.5 ng/mL). Homocysteine was significantly higher (P < 0.05) in homozygous variants (13.2 +/- 1.1 micromol/L) compared with homozygous subjects (10.9 +/- 0.4 micromol/L). Homozygous variants had significantly lower (P < 0.05) RBC folate (84.7 +/- 6.3 ng/mL) compared with wild-types (112.2 +/- 5.2 ng/mL) and heterozygous individuals (125.1 +/- 6.6 ng/mL). No significant difference in RBC folate was observed between wild-types and heterozygotes. The A1298C variant did not influence plasma homocysteine, folate, 5-methyltetrahydrofolate, vitamin B12, or RBC folate. Lymphocyte DNA stability biomarkers (strand breaks, misincorporated uracil, and global DNA methylation) were similar for all MTHFR C677T or A1298C variants. CONCLUSION: Data from this study do not support the hypothesis that polymorphisms in the MTHFR gene increase DNA stability by sequestering 5,10-methylenetetrahydrofolate for thymidine synthesis and reducing uracil misincorporation into DNA.  相似文献   
68.
69.
Objectives.Our aim was to study correlations between survival, disease recurrence, and p53 protein expression in a well defined population-based series of vulval squamous cell carcinoma and immediate adjacent epithelial skin changes.Methods.One hundred fifteen vulval squamous cell carcinoma were studied. Epithelial skin changes immediately adjacent to tumor were classified into nonneoplastic epithelial disorders (NNED) or vulval intraepithelial neoplasia (VIN). Archival specimens containing primary tumor and immediate adjacent skin were immunostained with a mouse monoclonal antibody to p53 protein.Results.p53 overexpression, defined as greater than 10% nuclear epithelial staining, was observed in 68% of tumors. Tumor immunostaining did not correlate with actuarial survival or disease-free interval. p53 overexpression was associated with a nonsignificant trend toward shorter disease-free interval in those tumors with nodal metastatic disease at diagnosis (P= 0.07). The only clinicopathological variable found to correlate with p53 expression was tumor grade (P= 0.002). Immediate adjacent abnormal skin changes were associated with p53 overexpression in 32% of cases. Adjacent normal skin did not immunostain for p53. p53 overexpression was most likely to occur in adjacent epithelial changes incorporating both NNED and high grade VIN (P= 0.005). Patterns of epithelial p53 overexpression in adjacent abnormal skin were either basal or full thickness. Full thickness epithelial p53 overexpression was most likely to occur in those disorders containing VIN (P< 0.0001). Positive immunostaining of adjacent skin abnormalities did not predict local tumor recurrence.Conclusions.This study demonstrates that although vulval squamous tumor p53 expression is not of prognostic significance, distinct immunostaining patterns can be observed in immediate adjacent skin. Vulval epithelial skin disorders displaying histological features of both NNED and VIN III may contain a profile of underlying molecular change which is of significance in subsequent tumor development.  相似文献   
70.
Yang  GY; Liao  J; Kim  K; Yurkow  EJ; Yang  CS 《Carcinogenesis》1998,19(4):611-616
In order to study the biological activities of tea preparations and purified tea polyphenols, their growth inhibitory effects were investigated using four human cancer cell lines. Growth inhibition was measured by [3H]thymidine incorporation after 48 h of treatment. The green tea catechins (-)-epigallocatechin-3-gallate (EGCG) and (-)- epigallocatechin (EGC) displayed strong growth inhibitory effects against lung tumor cell lines H661 and H1299, with estimated IC50 values of 22 microM, but were less effective against lung cancer cell line H441 and colon cancer cell line HT-29 with IC50 values 2- to 3- fold higher. (-)-Epicatechin-3-gallate, had lower activities, and (-)- epicatechin was even less effective. Preparations of green tea polyphenols and theaflavins had higher activities than extracts of green tea and decaffeinated green tea. The results suggest that the growth inhibitory activity of tea extracts is caused by the activities of different tea polyphenols. Exposure of H661 cells to 30 microM EGCG, EGC or theaflavins for 24 h led to the induction of apoptosis as determined by an annexin V apoptosis assay, showing apoptosis indices of 23, 26 and 8%, respectively; with 100 microM of these compounds, the apoptosis indices were 82, 76 and 78%, respectively. Incubation of H661 cells with EGCG also induced a dose-dependent formation of H2O2. Addition of H2O2 to H661 cells caused apoptosis in a manner similar to that caused by EGCG. The EGCG-induced apoptosis in H661 cells was completely inhibited by exogenously added catalase (50 units/ml). These results suggest that tea polyphenol-induced production of H2O2 may mediate apoptosis and that this may contribute to the growth inhibitory activities of tea polyphenols in vitro.   相似文献   
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