Fluctuations of cell geometry and their nonequilibrium thermodynamics in living epithelial tissue.

We measure different contributions to entropy production in a living functional epithelial tissue. We do this by extracting the functional dynamics of development while at the same time quantifying fluctuations. Using the translucent Drosophila melanogaster pupal epithelium as an ideal tissue for high-resolution live imaging, we measure the entropy associated with the stochastic geometry of cells in the epithelium. This is done using a detailed analysis of the dynamics of the shape and orientation of individual cells which enables separation of local and global aspects of the tissue behavior. Intriguingly, we find that we can observe irreversible dynamics in the cell geometries but without a change in the entropy associated with those degrees of freedom, showing that there is a flow of energy into those degrees of freedom. Hence, the living system is controlling how the entropy is being produced and partitioned into its different parts.

Nuclear localization of v-Abl leads to complex formation with cyclic AMP response element (CRE)-binding protein and transactivation through CRE motifs.

Deregulated expression of v-abl and BCR/abl genes has been associated with myeloproliferative syndromes and myelodysplasia, both of which can progress to acute leukemia. These studies identify the localization of the oncogenic form of the abl gene product encoded by the Abelson murine leukemia virus in the nuclei of myeloid cells and the association of the v-Abl protein with the transcriptional regulator cyclic AMP response element-binding protein (CREB). We have mapped the specific domains within each of the proteins responsible for this interaction. We have shown that complex formation is a prerequisite for transcriptional potentiation of CREB. Transient overexpression of the homologous cellular protein c-Abl also results in the activation of promoters containing an intact CRE. These observations identify a novel function for v-Abl, that of a transcriptional activator that physically interacts with a transcription factor.

An analysis of signal processing algorithm performance for cortical intrinsic optical signal imaging and strategies for algorithm selection.

Intrinsic Optical Signal (IOS) imaging has been used extensively to examine activity-related changes within the cerebral cortex. A significant technical challenge with IOS imaging is the presence of large noise, artefact components and periodic interference. Signal processing is therefore important in obtaining quality IOS imaging results. Several signal processing techniques have been deployed, however, the performance of these approaches for IOS imaging has never been directly compared. The current study aims to compare signal processing techniques that can be used when quantifying stimuli-response IOS imaging data. Data were gathered from the somatosensory cortex of mice following piezoelectric stimulation of the hindlimb. The effectiveness of each technique to remove noise and extract the IOS signal was compared for both spatial and temporal responses. Careful analysis of the advantages and disadvantages of each method were carried out to inform the choice of signal processing for IOS imaging. We conclude that spatial Gaussian filtering is the most effective choices for improving the spatial IOS response, whilst temporal low pass and bandpass filtering produce the best results for producing temporal responses when periodic stimuli are an option. Global signal regression and truncated difference also work well and do not require periodic stimuli.

Vitamin E succinate inhibits proliferation of BT-20 human breast cancer cells: increased binding of cyclin A negatively regulates E2F transactivation activity.

Vitamin E succinate (VES) inhibited the proliferation of the estrogen receptor-negative human breast cancer cell line, BT-20, in the G1 phase of the cell cycle. The E2F proteins are integral transcriptional components in the regulation of cell growth. Overexpression of E2F-1 blocked the ability of VES to inhibit BT-20 cell growth, suggesting that VES regulation of E2F-1 activity leads to growth arrest of BT-20 cells. VES, although having little effect on E2F-1 steady-state protein levels, decreased E2F-1 phosphorylation and transactivation activity and increased cyclin A binding to E2F-1. GAL4-E2F-1 deletion mutant studies indicated that cyclin A negatively regulates E2F function. In VES-treated BT-20 cells, the cyclin A protein exhibited reduced kinase activity, which correlated with decreased steady-state levels and binding of cyclin-dependent kinase-2 to cyclin A and increased steady-state levels and binding of p21cip1 to cyclin A and cyclin-dependent kinase-2. The functional consequence of the negative regulatory effect of VES on E2F-1 function was shown by the ability of VES to inhibit the transcriptional activation of an E2F-1 responsive gene, c-myc. These studies show that VES induces growth inhibition of BT-20 cells through a mechanism that involves cyclin A-negative regulation of E2F-mediated transcription.

Vitamin E succinate induces Fas-mediated apoptosis in estrogen receptor-negative human breast cancer cells.

Vitamin E succinate (VES), a derivative of the fat-soluble vitamin D-alpha-tocopherol (vitamin E), inhibited growth and induced apoptotic cell death of estrogen receptor-negative human breast cancer cells. VES-induced apoptosis in MDA-MB-231 and SKBR-3 cells occurred through a Fas pathway. Total protein levels of the Fas receptor (Fas; APO-1/CD-95) and the Fas ligand (Fas-L) were increased following VES treatment. In addition, VES increased cell surface Fas expression. Fas-neutralizing antibodies and Fas-L antisense oligonucleotides blocked VES-induced apoptosis. The presence of Fas-L antisense oligonucleotides also completely blocked the VES-mediated increase in Fas-L protein expression. These data indicate a role for Fas signaling in VES-mediated apoptotic cell death of human breast cancer cells. These findings also suggest that VES may be of clinical use in the treatment of aggressive human breast cancers, particularly those that are refractory to antiestrogen therapy.

p120-v-Abl expression overcomes TGF-beta1 negative regulation of c-myc transcription but not cell growth.

Transformation of interleukin-3 dependent (IL-3) 32D-123 myeloid cells by p120-v-Abl produced the factor-independent 32D-abl cell line. In 32D-abl cells, myc expression was found to be significantly higher than in the parental cells and was correlated with increased E2F-1 protein expression and DNA binding ability. Surprisingly, in 32D-abl cells, TGF-beta1, a potent G1/S inhibitor of 32D-123 and 32D-abl cell growth, increased E2F transactivation as shown by increased c-myc promoter-CAT and GAL4-E2F-1 activity. In addition, TGF-beta1 was also found to increase E2F-1 protein levels but had no effect on steady-state retinoblastoma (RB) protein levels or phosphorylation state. In the absence of TGF-beta1, transient expression of RB in v-Abl expressing cells resulted in decreased c-myc transcription, inhibition of GAL4-E2F-1 driven transactivation and inhibition of cellular proliferation. RB and v-Abl were found to physically associate in vivo and in vitro via v-Abl's ATP binding region. In summary, these studies established that in myeloid cells: (1) v-Abl binds RB resulting in increased E2F-1-driven c-myc transcription, and (2) an alternative pathway exists for TGF-beta1-mediated growth inhibition of v-Abl-transformed cells, in which increased rather than decreased E2F-mediated c-myc transcription is observed.

An examination of proton translocation and energy conservation during heterotrophic nitrification.

Whether selected heterotrophic nitrifiers, as do the autotrophs, conserve energy during the oxidation of their nitrogenous substrates was studied. The examination of proton translocation of four different bacterial nitrifiers capable of pyruvic oxime [(PO), CH3-C(NOH)-COOH] nitrification and by an NH4+ oxidizing Arthrobacter sp. was initiated. Three of the PO nitrifying bacteria, all pseudomonads, oxidize hydroxylamine (NH2OH) at a greater rate than PO and yielded only stoichiometric protons when NH2OH was the reductant. The fourth bacterium, Alcaligenes faecalis ATCC 8750, an adept PO oxidizer, does not appreciably oxidize NH2OH. The bacterium displayed----H+NH2OH ratios far less than if NH2OH was stoichiometrically converted to nitrite. When given NH4+, the Arthrobacter sp. yielded proton translocation patterns which were inconsistent with the metabolic data collected concerning NH4+ oxidation. Thus no data was collected which supported energy conservation via proton translocation by these heterotrophic nitrifiers.

Use of a horror film in psychotherapy.

Modern improvements in the technology of cinematic special effects have ushered in a new genre of vivid and graphic horror film. The numerous sequels of these films attest to their popularity among adolescents and young adults. Considerable concern has arisen on the part of parents, professionals, and policymakers regarding adverse effects of these films upon children. The authors discuss the meaning of a horror film to a troubled 13-year-old boy and describe the use of the film in his psychotherapy. The modern horror film serves many of the same functions for the adolescent that the traditional fairy tale serves for the younger child.

Simultaneous closure of low cutaneous loop ureterostomies and excision of congenital ureterovesical junction strictures.

A case report of a child is presented in which double sectioing of the lower ureter was required to close simultaneously low cutaneous loop ureterostomies and to excise congenital ureterovesical junction strictures. One ureteroneocystostomy required revision. The vasculature of the ureteral segments was preserved by not mobilizing the ureter.

Transfer function measurement and analysis for a magnetic resonance imager.

The transfer function characteristics of a 1.5T imager have been determined. An edge response function (ERF) was obtained from a water/Plexiglas interface at various pixel widths ranging from 0.312 to 1.0 mm. An SE pulse sequence was used with a 5-mm transaxial slice. The ERF was smoothed, differentiated, and Fourier transformed to obtain MTF curves. The LSF was analyzed for skewness and kurtosis. The area under the MTF amplitude curves and the equivalent bandpass were calculated. All ERFs, LSFs, and MTFs were well behaved. The resulting LSF was Gaussian. All calculated MTFs had cutoff frequencies slightly less than the theoretical Nyquist limit. The MTF calculated from the theoretical Gaussian LSF is slightly superior to that calculated from experimental data and provides an upper limit to the MTF. Spatial resolution in our MR imager is dominated by the pixel size via the Nyquist sampling theorem. System performance is slightly less than theoretically predicted, possibly due to image processing algorithms during the reconstruction process.

Femoral neuropathy in renal transplantation.

Acute femoral neuropathy after renal transplantation is an uncommon and rarely recognized complication. Recovery of the nerve is usual. Although rare, five cases have come to our attention in the past twenty years. A detailed clinical and electrophysiological analysis with a six month follow-up is presented. A review of sixteen other reported cases is also provided. The possible pathophysiology including direct compression and nerve ischemia, is discussed. We believe that nerve ischemia, possibly caused by a steal phenomenon, occurs in all cases following the anastomosis of the graft renal artery to the internal iliac artery, with a superimposed component of compression in some cases. The severity of ischemia probably determines the degree of recovery.

Developing informatics as a discipline.

Informatics is developing in all of the disciplines related to healthcare. There are many aspects to informatics development which frequently appear to be unrelated and to lack cohesion. This paper builds on the development of a model for nursing informatics and proposes how the components of that model can interact to provide an outline for the development of informatics as a discipline. A understanding of the disciple allows us to organize the existing research and more importantly to understand the areas where research is lacking as the discipline is evolving.

Data mining: a strategy for knowledge development and structure in nursing practice.

Data mining is an emerging technique used more widely by the business world than the world of nursing and health care. However, this strategy can be helpful for improving the quality of decision making by clinicians and health care administrators. This paper addresses the concepts and techniques of data mining that could be useful for practicing nurses as well as nurse administrators. Data mining can be an important tool for the development of nursing knowledge and knowledge structures. An example of the use of the technique in an inpatient setting is provided and insights from the process are discussed.

Nursing decision making and the science of the concrete.

Information systems are going to change our understanding of nursing as a discipline and as a practice. The act of decision making will be the focus of the impact of information systems on nursing. The article models types of nursing knowledge, organizing them into concrete and abstract knowledge. Information systems will allow the inclusion of concrete science data, which has not been possible previously. Role performance is seen as a mechanism for the integration of the two sciences, and a new understanding for nursing decision making is proposed.

A framework for the transition from nursing records to a nursing information system.

The future of patient record keeping is being developed now. Critical aspects are in place with the development of computer communication standards for health care. The Institute of Medicine's report on the computerized patient record has galvanized many in the health care field to rethink their methods of record keeping. Nurses need to examine the history of the nursing record and look toward the development of a comprehensive nursing information system. Nurses, along with the other disciplines, must examine what they want the system of the future to encompass. A suggested framework for the information system has four major nursing components: (1) data storage component, (2) transaction log, (3) nursing decision support systems, and (4) an engine to link and combine the first three components and to present a consistent easy-to-use interface to the nurse. Done properly, this approach will reduce the amount of time nurses spend charting, add dimension to their notation, and increase the efficiency of data usage for clinical practice. The nursing information system must allow information availability in a manner that accentuates quality practice while releasing the nurse from time-consuming record keeping. These goals are possible to meet, but only if nurses plan for the design now, before it becomes a fait accompli.