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Biomedical subjects

A Telser

Publications and source records attributed to A Telser.

At least 19 recordsLinked to original sources

Development of a measure of attitude toward nutrition in patient care.

BACKGROUND: Development of reliable measures of medical student and resident attitudes about nutrition in patient care is needed before the effects of educational interventions or clinical experience can be gauged. This report describes the systematic development of a measure of attitude toward nutrition in patient care. It presents evidence about scale reliability and the absence of response bias that endorses the trustworthiness of data from the measure. METHODS: An eight-step attitude scale development procedure was used to create the Nutrition In Patient care Survey (NIPS). Data from five samples of first- and second-year medical students and first-year medical residents were subjected to factor analysis (PA2, varimax rotation), reliability analyses, and statistical analyses to test for demographic bias in the attitude data. RESULTS: A 45-item attitude measure was developed that contains five subscales derived from the factor analysis: (1) nutrition in routine care (NRC, 8 items); (2) clinical behavior (CB, 20 items); (3) physician-patient relationship (PPR, 8 items); (4) patient behavior/motivation (PBM, 3 items); and (5) physician efficacy (PE, 6 items). Each subscale yields reliable data in terms of internal consistency (alpha coefficients) and stability (test-retest reliability). Medical student and resident demographic variables have negligible influence on attitude scores. DISCUSSION: The NIPS subscales yield reliable data that can be used to assess outcomes in evaluation research on educational or clinical interventions or to predict patient care practices. Systematic attitude scale development increases the likelihood that the resulting measures will produce useful, trustworthy data.

Adult↗

Regulation of vocal fold transepithelial water fluxes.

Vocal fold hydration is critical to phonation. We hypothesized that the vocal fold generates bidirectional water fluxes, which are regulated by activity of the Na(+)-K(+)- ATPase. Western blots and immunohistochemistry demonstrated the presence of the alpha-subunit Na(+)-K(+)-ATPase in the canine vocal fold (n = 11). Luminal cells, basal and adjacent one to two layers of suprabasal cells within stratified squamous epithelium, were immunopositive, as well as basolateral membranes of submucosal seromucous glands underlying transitional epithelia. Canine (n = 6) and ovine (n = 14) vocal fold mucosae exhibited transepithelial potential differences of 8.1 +/- 2.8 and 9.3 +/- 1.3 mV (lumen negative), respectively. The potential difference and short-circuit current (ovine = 31 +/- 4 microA/cm(2); canine = 41 +/- 10 microA/cm(2)) were substantially reduced by luminal administration of 75 microM acetylstrophanthidin (P < 0.05). Ovine (n = 7) transepithelial water fluxes decreased from 5.1 +/- 0.3 to 4.3 +/- 0.3 microl x min(-1) x cm(-2) from the basal to luminal chamber and from 5.2 +/- 0.2 to 3.9 +/- 0.3 microl x min(-1) x cm(-2) from the luminal to basal chamber by luminal acetylstrophanthidin (P < 0.05). The presence of the Na(+)-K(+)-ATPase in the vocal fold epithelium and the electrolyte transport derived from its activity provide the intrinsic mechanisms to regulate cell volume as well as vocal fold hydration.

Animals↗

Expression of retinoic acid receptors in non-neoplastic epithelial disorders of the vulva and normal vulvar skin.

Retinoids and their nuclear retinoic receptors (RARs) are important modulators of epidermal cell proliferation and terminal differentiation. Aberrant expression of RARs in the epidermis has been found to be associated with altered differentiation capacity of keratinocytes. In this study, the expression of the various types of RARs (RAR-alpha, RAR-beta, and RAR-gamma) was investigated in surgical specimens from 17 patients with vulvar lichen sclerosus, 12 patients with vulvar squamous cell hyperplasia, and 11 specimens of normal vulvar skin by nonradioactive in situ hybridization. The results demonstrate that RAR-alpha expression is significantly decreased in lichen sclerosus (p < 0.0001) and squamous cell hyperplasia (p = 0.007) compared with normal vulvar skin. Furthermore, in normal vulvar skin RAR-alpha mRNA is mainly located in the suprabasal epidermal cell layers, whereas in lichen sclerosus RAR-alpha is expressed predominantly in the basal cell layers. In squamous cell hyperplasia RAR-alpha expression occurs in all cell layers. Compared with normal vulvar skin, RAR-gamma expression is higher in lichen sclerosus (p = 0.026), but no statistically significant differences are seen in squamous cell hyperplasia. These results suggest that partial loss and abnormal localization of RAR-alpha expression as well as increased RAR-gamma expression may play a role in the etiology of non-neoplastic epithelial disorders of the vulva.

Epidermis↗

In situ localization of S1-labeled actin filaments in chick lens epithelial cells.

The actin filaments in the lens epithelial cells of three-day and eight-day post-hatched chicks have been labeled in situ with myosin subfragment 1 (S1). Labeling was accomplished by injuring the lens transcorneally with an ultramicroneedle 5 min or 24 hr before detergent treatment and incubation in S1. A band of filaments found at the epithelio-fiber junction in normal, uninjured chick lens is labeled in the 5 min and 24 hr injury. A subcapsular labeled band is found only in the 24 hr injury, and may be the result of a healing process.

Actins↗

A sodium dodecyl sulfate--polyacrylamide gel electrophoresis system that separates peptides and proteins in the molecular weight range of 2500 to 90,000.

A discontinuous sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis system is described which provides superior resolution of polypeptides with molecular weights from approximately 2500 to 90,000. The system utilizes a relatively low-mobility acetate ion in the stacking gel and high-mobility strong anions, sulfate and chloride, as leading and trailing ions in the separating gel. The entire system is run at pH 7.8. The separating gel contains 8 M urea, and can be used at acrylamide concentrations from 5 to 18%, all with 5% crosslinker concentrations. Using a number of protein standards, the calibration curves obtained with this system are linear over the molecular weight range from 2500 to 90,000, regardless of acrylamide concentration. These studies indicate that by providing good resolution of small peptides, this system greatly extends the utility of one-dimensional peptide mapping techniques.

Animals↗

A low-molecular-weight soluble protein from bovine lingual epithelium. II. Purification and characterization.

In an earlier study of rat lingual epithelium, we examined the total SDS-soluble protein from epithelia isolated at different states of development by polyacrylamide gel electrophoresis. In this study, rather than work with total SDS-soluble proteins, we have carried out a series of sequential extractions of bovine lingual epithelium. To separate epithelium from connective tissue, slices of dorsal tongue mucosa were incubated in a solution containing EDTA and 4 proteolytic enzyme inhibitors. We have isolated and partially characterized a low-molecular-weight (LMW) protein from the phosphate-buffered saline extract of bovine lingual epithelium. In the work reported here, we describe some of the biochemical and immunologic characteristics of this protein. The bovine lingual LMW protein has a molecular weight of 8700 +/- 450, an isoelectric point of 4.7 +/- 0.2 pH units, and a high content of the acidic amino acids aspartate and glutamate. We prepared an antibody to LMW protein and examined its specificity by a microenzyme-linked immunosorbant assay (ELISA). We found that the antibody to LMW protein reacts very strongly against LMW protein while it exhibits no cross-reactivity with low levels of an authentic keratin protein but moderate cross-reactivity at higher concentrations of this authentic keratin protein. In a previous publication we have reported the immunohistochemical localization and distribution of this LMW protein.

Animals↗

Immunohistochemical localization of a low molecular weight, soluble protein from bovine lingual epithelium.

A low molecular weight (LMW) protein was isolated from bovine tongue epithelium and an antiserum to this protein elicited in rabbits. The indirect peroxidase-antiperoxidase (PAP) technique was used to localize LMW protein in several tissues from six mammalian species: cow, rat, mouse, squirrel, rabbit, and man. Immunoreactivity was demonstrable in stratified squamous epithelia from skin, tongue, cheek, esophagus, vagina, and palate. Epidermal derivatives, such as hair follicles, sebaceous glands and ducts of certain glands were also positively stained. Cornea exhibited weak immunoreactivity as did rabbit bladder. Other types of epithelia including those seen in kidney, thyroid, intestine, trachea, liver, submandibular gland, pancreas and uterus, were not immunoreactive when tested with antiserum to LMW protein. The antiserum was rendered unreactive after absorption with LMW protein but, when absorbed with a keratin polypeptide, most of the immunoreactivity was preserved. It is concluded that the distribution of the soluble LMW protein is similar to that of the insoluble keratin proteins in stratified squamous epithelia but the former is not demonstrable in many simple epithelia that contain keratins.

Animals↗

A specific stain for sulfhydryl groups in proteins after separation by polyacrylamide gel electrophoresis.

A new method is described for specifically staining protein sulfhydryl groups after the proteins have been separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in slab gels. The stain will detect as little as 0.25 microgram of lysozyme and 1 microgram of most other proteins; the range of sensitivity for a specific protein depending on its sulfhydryl content. Proteins with no cysteine residues (type I collagen) and glycoproteins do not cause spurious staining.

Cysteine↗

Cultured neuroblastoma cells and halothane: effects on cell growth and macromolecular synthesis.

Cultured mouse neuroblastoma cells were grown in air-CO2 or air-CO2-halothane-gassed incubators. In the presence of halothane the growth rate of the cells was inhibited in a dose-dependent manner; 2 per cent halothane completely inhibited cell growth, while at 0.3 per cent halothane, the growth rate was 74 per cent of the control rate. The biosynthesis of protein and RNA in cells grown in the control atmosphere and that in cells grown in 1 per cent halothane were compared by several techniques. No significant difference between the rates of synthesis of these two macromolecules could be detected. Furthermore, a comparison of labeled protein and RNA by SDS-polyacrylamide gel electrophoresis revealed no qualitative difference. From this and previous work it is concluded that halothane affects the morphology and growth rate of cultured mouse neuroblastoma cells by disrupting cytoplasmic actin-like micro-filaments.

Animals↗

Developmental changes in the protein profile of cornifying lingual epithelium.

Epithelia from the tongue dorsum of 14- to 21-day embryos, 21-day embryos, 3-week-old, and adult rats were separated from their connective tissues by incubation in balanced salt solution containing EDTA. Aliquots from total extracts of these tissues were electrophoresed on sodium dodecyl sulfate-polyacrylamide gels. Scans of gels stained with fast green (FG) revealed more than 20 peaks. Ten major peaks ranging from apparent molecular weights (MW) of 120,000 to 14,000 daltons comprised about 70% of the total protein on each gel. This report focuses primarily on two pairs of peaks, arbitrarily numbered 2 and 3 (MWs 71,000 and 69,000) and 9 and 10 (MWs 17,500 and 14,000). Peaks 9 and 10 predominated in the 15-day embryos where they comprised about 30% of the total protein. As development proceeded, there was a gradual shift in the protein profile in favor of peaks 2 and 3 until on the 20th day the relative amounts of these peaks reached a maximum and peaks 9 and 10 decreased in relative amounts. The protein profile on the 20th fetal day resembled that of the 3-week-old rats and the adults. The rise in the relative amounts of peaks 2 and 3 coincided with the morphologic appearance of large numbers of tonofilaments and the onset of cornification. When the gel was stained by a procedure specific for sulfhydryl groups, peaks 9 and 10 were especially reactive after the 18th day; plainmetric analysis revealed that these had twice the relative affinity for this stain than for FG whereas other peaks had equal or less affinity. The incorporation of [3H]cystine into peaks 9 and 10 was relatively greater than into the other proteins.

Animals↗

Alternative developmental pathways determined by environmental conditions in the cellular slime mold Dictyostelium discoideum.

The cellular slime mold Dictyostelium discoideum grows in the soil as a population of independent, uninucleate amoebae. Upon entrance to the stationary phase, the amoebae collect in multicellular aggregates to form organized fruiting bodies composed of spores and stalk cells. Depending upon environmental conditions, the developing aggregate either constructs the fruiting body at the site of aggregation or transforms into a structure that can migrate to a more favorable location. Environmental conditions that favor migration are (i) the accumulation of metabolite(s) produced by the aggregate and (ii) a low ionic strength in the substratum. Conditions that prevent migration or that stop a migrating slug are (i) the presence of buffer and (ii) illumination by overhead light.

Amoeba↗