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V Weaver

Publications and source records attributed to V Weaver.

11 recordsLinked to original sources
PubMed2003

An assessment of water quality, physical habitat, and biological integrity of an urban stream in Wichita, Kansas, prior to restoration improvements (phase I).

Urban development alters the natural hydrological conditions of many streams and rivers often resulting in the degradation of water quality, physical habitat, and biotic integrity of lotic systems. Restoration projects attempt to improve and maintain the ecological integrity of urban streams; however, few projects have quantified improvements to stream ecology following implementation of restoration measures. This paper summarizes pre-restoration data collected as part of an urban stream restoration project on Gypsum Creek in Wichita, Kansas. Water quality monitoring revealed eutrophic conditions in the stream and the presence of pesticides. Channelization has led to changes in physical habitat including bank erosion, sedimentation, loss of substrate and channel diversity, elimination of in-stream aquatic habitat, removal of riparian vegetation, and decreased base flows. Benthic macroinvertebrate communities appear degraded with more than 90% of individuals collected described as tolerant to anthropogenic stressors. Fish communities were assessed with an Index of Biotic Integrity and were rated as poor to fair, with trophic structure dominated by generalists, no sensitive species present, and one-third of the species collected considered non-native. Overall, the data collected strongly suggest that site-specific restoration measures need to be implemented in order to improve and maintain the ecological condition of Gypsum Creek. Recommendations for improvements have been made to city managers, with implementation beginning in spring 2003 (dependent upon funding availability).

Animals↗
PubMed1999

Constitutive expression of Heregulin induces apoptosis in an erbB-2 overexpressing breast cancer cell line SKBr-3.

We have previously reported that Heregulin (HRG)/neu differentiation factor (NDF) induced growth arrest and cellular differentiation in breast cancer cells overexpressing erbB-2 receptor. To elucidate the cellular mechanisms underlying the growth inhibition by HRG, we developed an in vitro model by transfection of HRG cDNA into the erbB-2 overexpressing breast cancer cell line, SKBr-3. We showed that the enforced expression of HRG in SKBr-3 cells induces dramatic morphological changes and pronounced inhibition of anchorage-dependent and -independent growth. Most SKBr-3/HRG-transfected (SK/HRG) cells exhibited about 15-fold increase in size and persisted as multinucleated cells with extended flattened vacuole-filled cytoplasm with reduced cell attachment. The growth suppression of SK/HRG cells was accompanied by a reduction in S phase, the presence of a G2-M cell cycle delay, and an increase in DNA aneuploid components. In addition, DNA fragmentation assays showed that HRG induced apoptosis of SKBr-3 cells. In contrast, while HRG treatment of other erbB-2 overexpressing breast cancer cell lines led to growth arrest and cell detachment, it did not induce apoptotic features. Thus, this study demonstrates that while growth arrest and cell detachment are general effects of HRG towards erbB-2 overexpressing cells, the ability of HRG to induce apoptosis is a phenomenon confined to selective cells including SKBr-3 cells.

Apoptosis↗
PubMed1998

Revised Medicare Policies for Support Surfaces: a review.

Support surfaces have been used for many years to treat or prevent pressure ulcers. In early 1996, the availability, application, and reimbursement for use of these products in the home care setting changed dramatically with the implementation of a new Medicare Part B "Medical Policy for Support Surfaces." This article reviews definitions and characteristics of the products as outlined in this policy, clinical criteria for patient qualification, and documentation requirements. Products assigned to Group 2 of the Medical Policy (those designed to treat patients with advanced stage wounds) are emphasized. Additional issues concerning billing, product selection based on patient need, environmental factors, and related financial implications are also presented.

Beds↗
PubMed1997

Protein synthesis, DNA degradation, and morphological changes during programmed cell death in labial glands of Manduca sexta.

Labial glands of the tobacco hornworm Manduca sexta (Lepidoptera: Sphingiidae, homologues of Drosophila salivary glands, undergo programmed cell death (PCD) in a 4-day period during larva-to-pupa metamorphosis. The programmed death of the labial gland was examined by electron microscopy and measurement of protein synthesis as well as measurement of DNA synthesis, end-labeling of single strand breaks, and pulsed-field gel electrophoresis. One of the earliest changes observed is a sharp drop in synthesis of most proteins, coupled with synthesis of a glycine-rich protein, reminiscent of silk-like proteins. From a morphological standpoint, during the earliest phases the most prominent changes are the formation of small autophagic vacuoles containing ribosomes and an apparent focal dissolution of the membranes of the endoplasmic reticulum, whereas later changes include differing destruction at the lumenal and basal surfaces of the cell and erosion of the basement membrane. By the fourth day of metamorphosis, individual cells become rapidly vacuolated in a cell-independent manner. In the vacuolated cells on day 3, chromatin begins to coalesce. It is at this period that unequivocal nucleosomal ladders are seen and end-labeling in situ or electrophoretic techniques document single on double-strand breaks, respectively. DNA synthesis ceases shortly after the molt to the fifth instar, as detected by incorporation of tritiated thymidine and weak TUNEL labeling. Large size fragments of DNA are seen shortly after DNA synthesis ceases and thence throughout the instor, raising the possibility of potential limitations built into the cells before their final collapse.

Animals↗
PubMed1993

Fouling one's own nest revisited.

Transport of hazards from the workplace to the home by workers is a previously recognized but poorly addressed public health problem. Particularly disturbing are the childhood intoxications which may result from such paraoccupational exposure. Work clothes and shoes appear to be a common vehicle for hazard transport in recently reported cases as they were in the past, although other "markers" for potential paraoccupational exposure may be derived from case reviews. These include: poor workplace hygiene, occupational intoxications in adult workers, and the "cottage industry" phenomenon. These markers are reviewed in the context of recently reported cases and strategies are suggested to mitigate these easily preventable exposures.

Child↗
PubMed1991

Regulation of renal 25(OH)D3 1 alpha-hydroxylase: signal transduction pathways.

In vitro, activation of the cAMP signalling pathway stimulates, whereas activation of PKC inhibits, 1,25(OH)2D3 synthesis. Since PTH activates both pathways, the ultimate effect of PTH on 1 alpha-hydroxylation in vivo likely depends on other endocrine-autocrine factors that impinge onto these signal transduction cascades. For example, 1,25(OH)2D3, a known repressor of 1 alpha-hydroxylation, may increase renal PKC amount-activity, thereby enhancing the inhibitory arm and preventing PTH stimulation of the 1-OHASE. In contrast, studies with diabetic rats suggest that insulin may allow cAMP-mediated stimulation to override PKC-mediated inhibition of 1-OHASE activity. Analogous to models proposed for regulation of adrenal steroid hydroxylases, it is likely that regulation of renal vitamin D hydroxylation involves both acute (reversible phosphorylation) and chronic (modulation of gene expression) mechanisms. However, the molecular details of these regulatory mechanisms remain to be resolved.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1971

Serum bile acids in liver disease.

Serum bile acids have been measured in patients with a wide variety of liver diseases using a technique which separates the major individual conjugated and free bile acids. Total serum bile acids may be elevated up to 100 times the normal concentration in patients with liver disease and this increase consists largely of conjugated bile acids. The ratio of glycine-conjugated to taurine-conjugated bile salts is low in all types of liver disease and this is found particularly in the serum of patients with obstructive jaundice. There is a decrease in the ratio of trihydroxy:dihydroxy cholanic acid in patients with cirrhosis.

Adult↗
PubMedDate not supplied

Evaluation of the VIDAS Listeria (LIS) immunoassay for the detection of Listeria in foods using demi-Fraser and Fraser enrichment broths, as modification of AOAC Official Method 999.06 (AOAC Official Method 2004.06).

A multilaboratory study was conducted to compare the VIDAS LIS immunoassay with the standard cultural methods for the detection of Listeria in foods using an enrichment modification of AOAC Official Method 999.06. The modified enrichment protocol was implemented to harmonize the VIDAS LIS assay with the VIDAS LMO2 assay. Five food types--brie cheese, vanilla ice cream, frozen green beans, frozen raw tilapia fish, and cooked roast beef--at 3 inoculation levels, were analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study, 1206 test portions were tested, of which 1170 were used in the statistical analysis. There were 433 positive by the VIDAS LIS assay and 396 positive by the standard culture methods. A Chi-square analysis of each of the 5 food types, at the 3 inoculation levels tested, was performed. The resulting average Chi square analysis, 0.42, indicated that, overall, there are no statistical differences between the VIDAS LIS assay and the standard methods at the 5% level of significance.

Animals↗