Inferior vena caval filters: an overview of current use

MTX-induced hepatic injury and liver enzyme elevations have been demonstrated after treatment of leukemia, gestational disease and during treatment of psoriasis and rheumatoid arthritis. A 40-year-old man with a long standing history of rheumatoid arthritis was treated with MTX over a 6 month period and developed an overwhelming hepatic necrosis. He was successfully transplanted.     

Two pleiotropic classes of daf-2 mutation affect larval arrest, adult behavior, reproduction and longevity in Caenorhabditis elegans

The nematode Caenorhabditis elegans responds to overcrowding and scarcity of food by arresting development as a dauer larva, a nonfeeding, long-lived, stress-resistant, alternative third-larval stage. Previous work has shown that mutations in the genes daf-2 (encoding a member of the insulin receptor family) and age-1 (encoding a PI 3-kinase) result in constitutive formation of dauer larvae (Daf-c), increased adult longevity (Age), and increased intrinsic thermotolerance (Itt). Some daf-2 mutants have additional developmental, behavioral, and reproductive defects. We have characterized in detail 15 temperature-sensitive and 1 nonconditional daf-2 allele to investigate the extent of daf-2 mutant defects and to examine whether specific mutant traits correlate with each other. The greatest longevity seen in daf-2 mutant adults was approximately three times that of wild type. The temperature-sensitive daf-2 mutants fell into two overlapping classes, including eight class 1 mutants, which are Daf-c, Age, and Itt, and exhibit low levels of L1 arrest at 25.5 degrees. Seven class 2 mutants also exhibit the class 1 defects as well as some or all of the following: reduced adult motility, abnormal adult body and gonad morphology, high levels of embryonic and L1 arrest, production of progeny late in life, and reduced brood size. The strengths of the Daf-c, Age, and Itt phenotypes largely correlated with each other but not with the strength of class 2-specific defects. This suggests that the DAF-2 receptor is bifunctional. Examination of the null phenotype revealed a maternally rescued egg, L1 lethal component, and a nonconditional Daf-c component. With respect to the Daf-c phenotype, the dauer-defective (Daf-d) mutation daf-12(m20) was epistatic to daf-2 class 1 alleles but not the severe class 2 alleles tested. All daf-2 mutant defects were suppressed by the daf-d mutation daf-16(m26). Our findings suggest a new model for daf-2, age-1, daf-12, and daf-16 interactions.     

Characterization of the interaction between manganese and tyrosine Z in acetate-inhibited photosystem II

When acetate-inhibited photosystem II (PSII) membranes are illuminated at temperatures above 250 K and quickly cooled to 77 K, a 240 G-wide electron paramagnetic resonance (EPR) signal is observed at 10 K. This EPR signal arises from a reciprocal interaction between the spin 1/2 ground state of the S2 state of the Mn4 cluster, for which a multiline EPR signal with shifted 55Mn hyperfine peaks is observed, and the oxidized tyrosine residue, YZ*, for which a broadened YZ* EPR spectrum is observed. The S2YZ* EPR signal in acetate-inhibited PSII is the first in which characteristic spectral features from both paramagnets can be observed. The observation of distinct EPR signals from each of the paramagnets together with the lack of a half-field EPR transition indicates that the exchange and dipolar couplings are weak. Below 20 K, the S2YZ* EPR signal in acetate-inhibited PSII is in the static limit. Above 20 K, the line width narrows dramatically as the broad low-temperature S2YZ* EPR signal is converted to a narrow YZ* EPR signal at room temperature. The line width narrowing is interpreted to be due to averaging of the exchange and dipolar interactions between YZ* and the S2 state of the Mn4 cluster by rapid spin-lattice relaxation of the Mn4 cluster as the temperature is increased. Decay of the S2YZ* intermediate at 200 K shows that the g = 4.1 form of the S2 state is formed and that a noninteracting S2-state multiline EPR signal is not observed as an intermediate in the decay. This result shows that a change in the redox state of YZ induces a spin-state change in the Mn4 cluster in acetate-inhibited PSII. The interconversion between spin states of the Mn4 cluster in acetate-inhibited PSII supports the idea that YZ oxidation or YZ* reduction is communicated to the Mn4 cluster through a direct hydrogen-bonding pathway, possibly involving a ligand bound to the Mn4 cluster.     

A conceptual foundation for human suffering in nursing care and research

Suffering is a significant, yet elusive, phenomenon in nursing and health care. Despite the importance and prevalence of suffering, there is only a small body of substantive literature on this topic. Some of the difficulty in expanding this knowledge base undoubtedly is related to the lack of a solid conceptual foundation for exploration of this phenomenon. Although there have been attempts to provide needed conceptual clarity, these efforts typically have not been based on systematic inquiry. In this study, the method of concept analysis was used to inductively generate a definition of the concept of suffering and to clarify various contextual aspects of the concept. Suffering is defined as an individualized, subjective, and complex experience that involves the assignment of an intensely negative meaning to an event or a perceived threat. Implications of these findings and additional contextual aspects of the concept for nursing practice and inquiry are presented. These results help to provide the conceptual foundation needed to enhance recognition and understanding of the human experience of suffering.     

Medical Information Bus usage for automated IV pump data acquisition: evaluation of usage patterns

SUMMARY: lymph node involvement in renal cell carcinoma is factor of very poor prognosis. In a series of 55 node-positive patients, 33 (60%) had simultaneous renal vein or vena cava invasion and 32 (58.2%) had metastases. Gross lymph node involvement was found in 39 patients (70.9%). Patients without venous invasion or metastasis may have a prolonged survival. In this group, those with microscopic nodal involvement can be cured, as the 10 and 15-year the actuarial survival rate is 54.5% Formal lymphadenectomy might have played a role in these results. Surgery can be performed when vein invasion is present without metastasis, but the prognosis is generally poor. Survival does not seem to be influenced by surgery when metastasis is present, regardless of the vein status.     

Quantitative measures of job variety: an experimental study-based on a psychophysical scaling technique

This paper presents some quantitative measures of job variety based on entropy statistics of information theory and on a modification of the Turner-Lawrence measure. By means of the psychophysical scaling technique of magnitude estimation, subjective judgements of variety for a number of different job situations were obtained from a total of 42 subjects. Power models or linear models between perceived variety and its physical correlates were found to explain up to 99% of the variation in perceived variety. Since job variety is generally considered to have a significant influence on motivation and job satisfaction, such quantitative models may possess practical utility for job design and for systematic programmes of job enlargement or enrichment.