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At least 109 records · Page 6Linked to original sources
PubMed1991

Analysis of responses to endothelins 1, 2, and 3 and sarafotoxin 6b in airways of the cat.

Airway responses to endothelin (ET) 1, ET-2, ET-3, and sarafotoxin 6b (S6b) were investigated in paralyzed, anesthetized, mechanically ventilated cats. Intravenous injections of ET-1 (0.1-1 nmol/kg) increased transpulmonary pressure (Ptp) and lung resistance (RL) and decreased dynamic compliance (Cdyn) in a dose-related manner. Airway responses to ET-1 were decreased significantly by sodium meclofenamate, a cyclooxygenase inhibitor, and by SKF 96148, a thromboxane receptor blocking agent. In terms of relative bronchoconstrictor activity, the thromboxane mimic, U-46619, was threefold more potent than ET-1 on a molar basis in increasing Ptp. ET-1 and ET-3 had similar bronchoconstrictor activity, and these peptides were less potent than ET-2 and S6b. Bronchoconstrictor responses to ET-2, ET-3, and S6b were also decreased significantly by meclofenamate and by thromboxane receptor blocking agents. The ET-1 precursor ET-1-(1-38) (big ET-1) caused a significant slowly developing increase in Ptp, RL, and aortic pressure (PAO) and a decrease in Cdyn, whereas a monocyclic ET-1 analogue and ET-1-(16-21) hexapeptide fragment had little or no activity in the airways. The present data indicate that ET-1, ET-2, ET-3, and S6b have significant bronchoconstrictor activity in the cat and that responses are dependent in part on the release of arachidonic acid and the formation of thromboxane A2. These data also suggest that big ET-1 is converted into a mature peptide in the cat and that ET-1-(16-21) hexapeptide fragment and a monocyclic ET-1 analogue have little if any bronchoconstrictor activity in the anesthetized cat.

Airway Resistance↗
PubMed2000

[Saarland Growth Study: sampling design].

The use of reference data to evaluate the physical development of children and adolescents is part of the daily routine in the paediatric ambulance. The construction of such reference data is based on the collection of extensive reference data. There are different kinds of reference data: cross sectional references, which are based on data collected from a big representative cross-sectional sample of the population, longitudinal references, which are based on follow-up surveys of usually smaller samples of individuals from birth to maturity, and mixed longitudinal references, which are a combination of longitudinal and cross-sectional reference data. The advantages and disadvantages of the different methods of data collection and the resulting reference data are discussed. The Saarland Growth Study was conducted for several reasons: growth processes are subject to secular changes, there are no specific reference data for children and adolescents from this part of the country and the growth charts in use in the paediatric praxis are possibly not appropriate any more. Therefore, the Saarland Growth Study served two purposes a) to create actual regional reference data and b) to create a database for future studies on secular trends in growth processes of children and adolescents from Saarland. The present contribution focusses on general remarks on the sampling design of (cross-sectional) growth surveys and its inferences for the design of the present study.

Adolescent↗
PubMed1994

Response of the Muta mouse lacZ/galE- transgenic mutation assay to DMN: comparisons with the corresponding Big Blue (lacI) responses.

The lacZ Muta mouse transgenic mutation assay was recently adapted into a selective assay based on use of E. coli galE(-) bacteria and phenyl galactoside (p-gal). A preliminary assessment of this selective assay was undertaken using a single oral dose of 10 mg/kg of dimethyl nitrosamine (DMN). The livers of treated male mice were assessed for UDS 2 h after dosing, and for lacZ- mutations 7, 11 and 20 days after dosing. A strong UDS response was recorded and a clear mutagenic response was observed at each of the 3 timepoints. Comparison of these data with earlier data derived using the Big Blue (lacI) mutation assay reveals a marginally greater sensitivity to DMN of the selective Muta mouse assay, an effect probably related to a biochemical difference between the strains of animal, as evidenced by the larger UDS response seen in the Muta mouse system. The original Muta mouse assay protocol was impractical. The galE- adaption makes the assay emminently practical and cost-effective. We are continuing to assess the true role of both the Big Blue assay and the galE- Muta mouse assay in mutagenicity/carcinogenicity prediction. The former assay enables access to B6C3F1 mice and F344 rats, the latter enables the rapid acquisition of data.

Animals↗
PubMed1994

Radiation-induced point mutations, deletions and micronuclei in lacI transgenic mice.

Ionizing radiation induces gene mutations (point mutations, deletions and insertions) as well as chromosome damage in mammalian cells. Although these effects have been studied extensively in cells in culture, until recently it has not been possible to analyze the mutagenic potential of ionizing radiation in vivo, especially at the molecular level. The development of transgenic mutagenesis systems has now made it possible to study the effects of ionizing radiation at both the molecular and chromosomal levels in the same animal. In this report we present preliminary data on the response of Big Blue lacI transgenic mice to ionizing radiation as measured by lacI mutations and micronuclei. C57Bl/6 transgenic mice were irradiated with 137Cs gamma-rays at doses ranging from 0.1 to 14 Gy, and expression times ranging from 2 to 14 days. Dose-related increases in the mutant frequency were observed after irradiations with longer expression times. Mutant plaques were analyzed by restriction enzyme digestion to detect large structural changes in the target sequence. Of 34 gamma-ray-induced mutations analyzed, 4 were large-scale rearrangements. 3 of these rearrangements were deletions within the lacI gene characterized by the presence of short regions of homology at the breakpoint junctions. The fourth rearrangement was a deletion that extended from within the alpha lacZ gene into downstream sequences and that had 43 bp of homology at the junction. These data indicate that the Big Blue lacI transgenic mouse system in sensitive to the types of mutations induced by ionizing radiation. To determine whether the presence of the transgene affects micronucleus induction we compared the response of nontransgenic to hemizygous transgenic B6C3F1 mice and the response of nontransgenic to hemizygous and homozygous transgenic C57Bl/6 mice. The presence or absence of the lacI transgene had no effect on spontaneous micronucleus frequencies for either strain. However, radiation-induced micronucleus frequencies were significantly higher in hemizygous lacI B6C3F1 mice than in nontransgenic litter mates; the converse was true in C57Bl/6 mice. These data suggest that the lacI transgene does not cause chromosome instability as measured by spontaneous micronucleus levels. However, the response of these transgenic mice to a variety of clastogenic agents needs to be investigated before they are integrated into standard in vivo assays for chromosome damage.

Animals↗
PubMedDate not supplied

[An algorithm of computerized processing of molecular-genetic data for personality identification based on the outcome of events involving numerous victims].

Computerized systems of data processing are a high-efficiency tool for the storage and processing of big volumes of molecular genetic data as well as for the forensic medical identification of personality in events involving enormous unidentified bodies coming from zones of calamity or natural disaster. Described in the paper is a sequence of actions undertaken by the expert when the DNAdacto and mDNAbase soft tools are in use. The algorithm of computer-based expert analysis of typing of chromosome and mitochondrial DNA was tested at the 124th Central laboratory of medical-criminal identification of Russia's defense ministry; it was proven to be highly effective for identification made in events with numerous unidentified bodies.

Algorithms↗
PubMed2003

Application of the tracer-aerosol gradient interpretive technique to sulfur attribution for the big bend regional aerosol and visibility observational study.

A simple data analysis method called the Tracer-Aerosol Gradient Interpretive Technique (TAGIT) is used to attribute particulate S and SO2 at Big Bend National Park in Texas and nearby areas to local and regional sources. Particulate S at Big Bend is of concern because of its effects on atmospheric visibility. The analysis used particulate S, SO2, and perfluorocarbon tracer data from six 6-hr sampling sites in and near Big Bend National Park. The data were collected in support of the Big Bend Regional Aerosol and Visibility Observational (BRAVO) Study; the field portion was conducted from July through October 1999. Perfluorocarbon tracer was released continuously from a tower at Eagle Pass, TX, approximately 25 km northeast of two large coal-fired power plants (Carbon I and II) in Coahuila, Mexico, and approximately 270 km east-southeast of Big Bend National Park. The perfluorocarbon tracer did not properly represent the location of the emissions from the Carbon power plants for individual 6-hr sampling periods and attributed only 3% of the particulate S and 27% of the SO2 at the 6-hr sites in and near Big Bend to sources represented by the tracer. An alternative approach using SO2 to tag "local" sources such as the Carbon plants attributed 10% of the particulate S and 75% of the SO2 at the 6-hr sites to local sources. Based on these two approaches, most of the regional (65-86%) and a small fraction (19-31%) of the local SO2 was converted to particulate S. The analysis implies that substantial reductions in particulate S at Big Bend National Park cannot be achieved by only reducing emissions from the Carbon power plants; reduction of emissions from many sources over a regional area would be necessary.

Aerosols↗
PubMed1991

[A phenomenological study on mother-infant interacting behavior patterns relating to newborn infant feeding in Korea].

The purpose of this study was to describe mother-infant interacting behavior patterns related to newborn infant feeding and to explore the mother's cultural belief about their infant. The data collection was conducted by observation and interview. Twenty-five mothers and their newborn infants who were normally delivered and were also planned to breastfeed were comprised as the subjects of this study. All subjects were interviewed and observed individually at 1 to 5 days after the delivery at the hospital, mid-wife's clinic, Maternal Child Health Center and their home throughout the country from remote area to big city. The observation data were recorded with symbolic letter on a recording sheet newly developed as a result of preliminary study. The interview data were tape recorded and then recorded in narrative form. Mother-infant interaction behaviors in early-feeding period were analyzed based on 19 analytic sub-categories and their composing elements. Unit of analysis were mother, infant and mother-infant dyad. 8 analytic categories draw from the data. Each were preparation, instrument, interaction inducing, evaluation referred to mother's behavior, preparation, instrument, interaction inducing referred to infant's behavior and synchronic behaviors referred to mother-infant dyad. Frequencies of behavior items based on the categories were converted to percent. The result showed that in mother's preparation behavior, the breast condition of Korean mother can be an affecting factor for mother-infant interaction during feeding, and vocalization behavior was observed most frequently in interaction inducing behavior while the least frequent behavior observed was contacting. Subcultural characteristics of mother-infant interaction behaviors were analyzed for their relationships between groups of mothers who have lived in remote area vs urban area, and who were multipara vs primipara. Using a chi-square test, there were statistically significant relationships in the activity of psychological readiness in preparation behavior and the movement of extremities for the position of instrumental behavior in both groups. However, interaction inducing behaviors were not related with statistical significance in any set of groups. Accomplishment of marriage, bonding and emotional mediation of family members were the categories related to mother's cultural belief about the infant in aspect of functional values. Infant at birth is considered little more than a biological organism without social capabilities. Although the newborn infant is still be attached to his mother, he makes his mother extend her territoriality. The mother's interacting behavior toward her infant based on those beliefs appeared task oriented, separative behavioral series.(ABSTRACT TRUNCATED AT 400 WORDS)

Breast Feeding↗
PubMed1995

Measurement of C-terminal fragment of big endothelin-1: a novel method for assessing the generation of endothelin-1 in humans.

We developed a procedure for individual measurement of big endothelin-1 (big ET-1) and the two products of big ET-1 conversion (ET-1 and C-terminal fragment (CTF) of big ET-1 (big ET-1(22-38)), using selective solid-phase extraction and specific radioimmunoassays. These techniques were used to measure the levels of these peptides in extracts of human plasma after brachial artery infusions of big ET-1. Infusion of big ET-1 (50 pmol/min, n = 6) caused a decrease in forearm blood flow from 3.03 to 1.55 ml/dl/min after 60 min (p < 0.05). In agreement, the levels of plasma immunoreactive (IR) big ET-1, ET, and CTF were significantly increased from basal levels in the infused arm (from undetectable to 386 pM, 2.2-7.5 pM, and 0.17-37 pM, respectively; p < 0.05). In the presence of the metalloprotease inhibitor phosphoramidon (30 nmol/min), the increase in IR-ET and the associated vasoconstriction were abolished. However, IR-CTF was still detected, suggesting that either some conversion by phosphoramidon-insensitive endothelin-converting enzyme (ECE) was occurring and/or that CTF was being preserved from further proteolysis by phosphoramidon. These data confirm that exogenous big ET-1 is locally converted to ET-1 and CTF in the human forearm, at least in part by a phosphoramidon-sensitive ECE. Furthermore, because measurable levels of newly synthesized ET-1 are probably rapidly reduced as a result of receptor binding, the assay of IR-CTF may be a more sensitive measure of the overexpression of ET-1 in disease.

Adult↗
PubMed1984

[The heterogeneity of serum hPRL in a patient with a giant prolactinoma].

The heterogeneity of hPRL in the serum of a patient with a giant prolactinoma (hPRL 27 micrograms/ml) was studied employing gel chromatography, RIA and lymphoma cell bioassay. After gel filtration of serum sample on Sephadex G-100 (superfine) column, a few hPRL peaks were detected by RIA. Rechromatography of the second peak, which eluted between the void volume and the small third peak, revealed four hPRL peaks designated big-big hPRL, medium-big hPRL, big hPRL and little hPRL, with BA/RIA ratio 1.3 approximately 2.6, 0.8 approximately 1.2, 0.3 approximately 0.7 and 0.7 approximately 1.5, respectively. The molecular weight of medium-big hPRL was estimated as 80K approximately 90K daltons. Most of big-big, medium-big and big hPRL were converted to little hPRL after mercaptoethanol treatment. These data suggest that most of big-big, medium-big and big hPRL are aggregates of little hPRL.

Adult↗
PubMed2001

Functional magnetic resonance imaging of the pediatric swallow: imaging the cortex and the brainstem.

OBJECTIVE: To design and implement a functional magnetic resonance imaging (fMRI) protocol to investigate the cortical and brainstem patterns of activity in children with regard to the act of swallowing. STUDY DESIGN: Pilot study to assess the clinical feasibility of the project. METHODS: Using a 3T Bruker Biospec 30/60 MRI scanner, images were obtained using the Behavior Interleaved Gradient/Blood Oxygen Level Dependent (BIG-BOLD) image acquisition method. Initially, regions of interest (ROI) were developed to identify the mean time from the onset of a swallow to maximum cortical blood flow in the motor cortex. Using this data to design the BIG-BOLD acquisition method followed by postprocessing of the data, images from two volunteer adults and four volunteer children were obtained. RESULTS: The average time from the onset of a swallow to maximum cortical blood flow was 6 to 8 seconds. Regions of cortical activity include pre- and post-central gyrus (Brodmann's areas 3 and 4), superior motor cortex (B.A. 24), insula, inferior frontal cortex (B.A. 44 and 45), Heschl gyrus (B.A. 41 and 42), putamen, globus pallidus, and the superior temporal gyrus (B.A. 38). Of particular note is the first mapping of the functional activity of swallowing at the level of the brainstem; activity was seen in the region of the nucleus ambiguous. CONCLUSIONS: fMRI provides a novel means of studying the central processes of both normal swallowing and its various pathologic forms in children. Further understanding of how a child coordinates a swallow and how this coordination can be altered at the level of the brainstem and cortex may aid in the development of novel rehabilitative strategies.

Adolescent↗
PubMed2000

What is beyond the big five? Plenty!

In a recent analysis of personality data, Saucier and Goldberg (1998) sought to answer the question, What is beyond the Big Five? Those authors evaluated numerous clusters of English person-descriptive adjectives that have been suspected of referring to non-Big Five dimensions of personality. Their results led them to conclude that most, if not all, traits of personality can be adequately subsumed within the Big Five factor space. In contrast, our reanalysis of Saucier and Goldberg's own data, using a more realistic criterion for deciding on whether a variable does or does not fall within a particular factor space, contradicts their claim. We are led to the conclusion that there are plenty of dimensions of behavior beyond the Big Five.

Female↗
PubMed1995

Child survival in big cities: the disadvantages of migrants.

Data from 15 Demographic and Health Surveys are used to examine whether rural-urban migrants in developing countries experience higher child mortality after settling in towns and cities than do lifelong urban residents, and if so, what individual or household characteristics account for this. Findings indicate that children of female migrants from the countryside generally have much poorer survival chances than other urban children. This survival disadvantage is more pronounced in big cities than in smaller urban areas, among migrants who have lived in the city for many years than among recent migrants, and in urban Latin America than in urban North Africa and sub-Saharan Africa. Within big cities, higher child mortality among migrant women is clearly related to their concentration in low-quality housing, and in part to fertility patterns at early ages of children and mother's educational attainment at later ages. Excess child mortality among urban migrants may also result from factors associated with the migration process, that are outlined in this study but not included in the analysis. Evidence of moderately high levels of residential segregation of migrant women in big cities suggests that opportunities exist for urban health programs to direct interventions to this disadvantaged segment of city populations.

Adolescent↗
PubMed1986

Exclusion of spheres by agarose gels during agarose gel electrophoresis: dependence on the sphere's radius and the gel's concentration.

Agarose gel electrophoresis of spheres (radius = R) has been used to determine the effective radius (PE) of the pores of an agarose gel (percentage of agarose in a gel = A). The value of PE at a given A was taken to be the R of the largest sphere that enters the gel. When log PE is plotted as a function of log A, the results can be represented by: PE = 118A-0.74 for 0.2 less than or equal to A less than or equal to 4.0 (PE in nm). However, the data suggest significant nonlinearity in this plot, the magnitude of the exponent of the PE vs A relationship increasing by about 20% as A increases from 0.2 to 4.0. From these data, PE's as big as 1500 nm and as small as 36 nm can be achieved with agarose gels formed with unmodified, unadulterated agarose and usable for electrophoresis.

Electrophoresis↗