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At least 955 records · Page 53Linked to original sources
PubMed1999

[Effect of plasma-treatment on suppression of drug adsorption to the surface of plastic infusion bag].

Plastics has been widely used at the hospitals and dominates the field of the manufacture of infusion bag sets and packaging materials as a disposable product. Recently, it has been reported, however, that expected drug effects could not be obtained owing mainly to the drug adsorption to the surface of plastic bags observed when several injection drugs such as nitroglycerin, isosorbide dinitrate, diazepam, and insulin were injected mixedly into a certain plastic intravenous bags. And there is a possibility of the occurrence of chemical reactions between the added drugs and the surface of plastic bags. We also can not deny the possibility of the dissolution of softener from the plastic bags. On the other hand, we have been working on the nature of plasma treatment of polymer surfaces by irradiation of low temperature plasma and its pharmaceutical application studies. In this study, we obtained the data concerning the effect of plasma treatment on the reduction of adsorption of insulin to the surface of ethylene-vinylacetate (EVA) bag.

Adsorption↗
PubMed2006

Effect of plastic strain energy density on polymer optical fiber power losses.

We explore the dependence of power losses on average plastic energy densities as rays propagate along deformed polymer optical fibers (POFs). The variation of power losses in deformed POFs with different bend radii and elongations are measured and analyzed. Three-dimensional elastic-plastic finite-element models are used to calculate average plastic energy densities in deformed POFs. The results indicate that the average plastic energy density introduced in a deformed POF can be considered a key index with which to study the power loss. Based on the experimental results, a curve-fitted equation is proposed for estimating the power loss by using the average plastic energy density for various bend radii.

Journal Article↗
PubMed2001

Comparative in vivo lung delivery of hydrofluoroalkane-salbutamol formulation via metered-dose inhaler alone, with plastic spacer, or with cardboard tube.

STUDY OBJECTIVE: To compare the lung delivery of chlorofluorocarbon-free salbutamol via a pressurized metered-dose inhaler (pMDI) alone, a pMDI with a small-volume plastic spacer, and a pMDI with a cardboard tube. DESIGN: A randomized, single (investigator)-blind, three-way, crossover study. SETTING: The Asthma and Allergy Research Group, Ninewells Hospital, University of Dundee, Dundee, Scotland, UK. PARTICIPANTS: Twelve healthy volunteers aged 16 to 65 years. INTERVENTIONS: The subjects were administered 400 microg of salbutamol via a pMDI alone, via a pMDI plus a small-volume plastic spacer, or via a pMDI plus a cardboard tube. MEASUREMENTS AND RESULTS: Blood samples for plasma salbutamol concentrations were taken at 5 min, 10 min, and 20 min after inhalation, to measure lung bioavailability as a surrogate for relative lung dose. The addition of the plastic spacer resulted in a significantly higher maximal plasma salbutamol concentration (CMAX) and average plasma salbutamol concentration (CAV) than the pMDI used alone. This amounted to a 1.48-fold (32%) difference (95% confidence interval [CI], 1.03 to 2.13) for CMAX and a 1.42-fold (30%) difference (95% CI, 1.01 to 2.00) for CAV. There was no significant difference in the CMAX or CAV comparing the addition of the cardboard tube with the plastic spacer or the pMDI alone. CONCLUSIONS: Using a chlorofluorocarbon-free pMDI with a plastic spacer produced statistically, but not biologically, significant greater lung delivery of salbutamol. If a spacer is required for reasons other than increasing delivered drug dose, then the addition of a readily available cardboard tube will fulfill many of the required functions with no expense to the patient.

Administration, Inhalation↗
PubMed2005

Plasticity and tissue regenerative potential of bone marrow-derived cells.

Diverse in vivo studies have suggested that adult stem cells might have the ability to differentiate into cell types other than those of the tissues in which they reside or derive during embryonic development. This idea of stem cell "plasticity" has led investigators to hypothesize that, similar to embryonic stem cells, adult stem cells might have unlimited tissue regenerative potential in vivo, and therefore, broad and novel therapeutic applications. Since the beginning of these observations, our group has critically examined these exciting possibilities for mouse bone marrow-derived cells by taking advantage of well-characterized models of tissue regeneration, Cre/lox technology, and novel stem cell isolation protocols. Our experimental evidence does not support plasticity of hematopoietic stem cells as a frequent physiological event, but rather indicates that cell fusion could account for reported cases of hematopoietic stem cell plasticity or "transdifferentiation" in vivo. Our studies highlight the need for meticulous technical controls during the isolation, transplantation, tracking, and analysis of bone marrow-derived cells during in vivo studies on plasticity. Further studies will be necessary to better define experimental conditions and criteria to unequivocally prove or reject plasticity in vivo. In this review, we focus on results from several studies from our laboratory, and discuss their conclusions and implications.

Animals↗
PubMed2005

Stem cell plasticity and issues of stem cell therapy.

Today, there is much evidence suggesting that organ-specific stem cells need not rely completely on their own sources for maintenance and regeneration of an organism. In certain circumstances, mostly related to tissue damage, stem cell populations residing past the affected organ can contribute to its recovery--that means from different cell lines and also in tissues from another germ layer. The key factor in formation of self-renewing cellular clones is the presence of stem cells either from the tissue of origin or stem cells migrating from other areas and their successful settlement in an empty niche of the damaged tissue. Stem cell plasticity is the ability of adult tissue-specific stem cells to switch to new identities. The term plasticity also means stem cell phenotypic potential, which is broader than phenotypes of differentiated cells in their original tissues. Many laboratories have given evidence on stem cell plasticity; however, the presented results met with many objections from others. In the first part of our report we wish to refer to several issues associated with stem cell plasticity, transdifferentiation and fusion. Recent experimental results show that stem cells will play a key role in cell therapy. But there are still many questions to answer for scientists engaged in stem cell research. Is it possible to induce cells from one type of tissue to look and act as cells of another tissue? Do these changes occur naturally? Could plasticity be used in the treatment of fatal diseases? Cell therapy is one of the methods to treat damaged myocardial tissue. However, recent results with autologous bone marrow cells in the treatment of damaged myocardium show that this method has still many unanswered questions concerning cells, cytokines, microenvironment and other factors responsible for reparation. To date, there are many opinions either recommending or denying this method in different modifications. One question has not yet been definitely solved: What are the conditions for us to accept this method--its safety and efficacy? The future will show whether these our hopes and expectations will be fulfiled. Many experiments are needed before at least some of these questions may be answered and cell therapy become an important method for the benefit of our patients.

Cell Differentiation↗
PubMed2004

Limits to phenotypic plasticity: flow effects on barnacle feeding appendages.

Phenotypic plasticity, the capacity of a given genotype to produce differing morphologies in response to the environment, is widespread among marine organisms (1). For example, acorn barnacles feed by extending specialized appendages (the cirral legs) into flow, and the length of the cirri is plastic: the higher the velocity, the shorter the feeding legs (2,3). However, this effect has been explored only for flows less than 4.6 m/s, slow compared to typical flows measured at sites on wave-exposed shores. What happens at faster speeds? Leg lengths of Balanus glandula Darwin, 1854, an acorn barnacle, were measured at 15 sites in Monterey, California, across flows ranging from 0.5 to 14.0 m/s. Similar to previous findings, a plastic response in leg length was noted for the four sites with water velocities less than 3 m/s. However, no plastic response was present at the 11 sites exposed to faster velocities, despite a 4-fold variation in speed. We conclude that the velocity at which the plastic response occurs has an upper limit of 2-4 m/s, a velocity commonly exceeded within the typical habitat of this species.

Acclimatization↗
PubMed1981

Plasticity of dendritic spine formation: a state-dependent stochastic process.

This study proposes that plasticity of dendritic spine formation may be modeled as distribution patterns imbedded in a spine length-dependent and density-dependent stochastic process. Modeling the jewel fish tectal interneuron revealed a critical 10-36 micron region where spine length plasticity was predicted to be most detectable. This hypothesis was tested by comparing neurons sampled from jewel fish reared for 4 years in a crowded environment (1 fish/5.64 l) with uncrowded controls (1 fish/25 l). The interaction between fish groups and the location of spine length differences was significant (p less than 0.01) within the basal 10-30 micron dendritic segment. Spine head widths were also significantly smaller (p less than 0.01) in the crowded fish over the entire dendrite. These findings suggest two modes of neuronal plasticity: (1) plasticity of spine length during formation, and (2) plasticity in spine head width after the spine is formed.

Animals↗
PubMed1999

[Genetic differences in plastic responses to density between ecotypes of Arabidopsis thaliana].

One of the most promising directions in the study of phenotypic plasticity is its detailed analysis in organisms that are also well-studied in other aspects. Also, conclusions based on plasticity studies in environmental gradients that closely mimic natural variation are shown to be the most relevant. Following those directions, we conducted this study of phenotypic plasticity on the currently best available model system in flowering plants--Arabidopsis thaliana, and utilized one of the most common variations experienced in the wild--variation in density. Four Arabidopsis thaliana commonly used inbred lines (ecotypes) were grown in densities from one to seven plants per pot. Both phenotypic plasticity and its genetic variability were detected for almost all of 11 analyzed traits, with analyzed ecotypes responding strongly to density of just two plants per pot. Density had small effect on life history and moderate effect on size traits, while vegetative and reproductive traits responded strongly. Mortality of plants during the experiment was almost absent, showing that all densities corresponded to the medium density phase in which "carrying capacity" is not yet reached. Genetic variability for phenotypic plasticity was in most cases the result of profound deviation of only one ecotype from the response of others. In the case of reproductive output, however, G x E interaction was the result of greater between-ecotype variability at lower densities. If we reasonably assume that dense stands are more common in the wild, this difference between ecotypes (populations) closely resembles the cases of so-called potential variability within populations.

Arabidopsis↗
PubMed2003

Deciphering indented impressions on plastic.

The questioned document laboratory is often called upon to decipher writing that has been erased, obliterated, or that has faded. In cases like these, the original writing is no longer legible to the naked eye, but may be enhanced using various light sources. Certain remnants of the ink's components absorb into the substrate's fibers and can be visualized, usually as luminescence or absorbance. A case is described here that involved the theft of a credit card. An empty plastic credit card holder was found in the possession of a suspect, and as submitted for examination. Indented impressions could be discerned on its clear plastic window and presumably originated from the credit card that had been held in the envelope. These indented impressions were deciphered in the hope that they would reveal enough details from the credit card to establish a connection between the plastic envelope and the stolen credit card. With methods generally utilized in the toolmarks and materials laboratory and the photography laboratory of the Israel Police, most of the indented impressions on the plastic were deciphered and a connection between the plastic envelope and the stolen credit card was demonstrated.

Journal Article↗
PubMed2005

[Plasticity and application of marrow-derived stem cells].

OBJECTIVE: To investigate plasticity of marrow-derived stem cells, possible mechanisms and application. METHODS: The recent literature concerned plasticity of marrow-derived stem cells was extensively reviewed. RESULTS: Although stem cells plasticity has not been proven, there is more and more evidence to show that the stem cells may have the plasticity and at least four different mechanisms are explained. CONCLUSION: The extensive research will be required. If the plasticity is proven, adult stem cells can be used for more therapeutic purposes. For example, the use of stem cells from bone marrow may correct genetic or degenerative disorders of a second organ from which stem cells are more difficult to isolate.

Animals↗
PubMed2006

Genetic differences between populations and habitats in Lamium purpureum plastic response to conspecific density.

Plants from Open and Shade habitats in two natural populations (Vrsac and Avala) were grown in two densities (High and Low). As expected, density had significant effect on most of measured traits and that effect was concordant with Shade avoidance syndrome predictions. Genetic differences between populations both in mean trait values and in plastic responses to density were also detected. Number of leaves and flowers showed plasticity in Avala population only, while shoot weight was plastic in both populations but with greater plasticity in Avala population. Differences between habitats for plant height and number of internodes were present in Vrsac population only. Habitat difference in response to density was revealed for seed weight and it was due to lack of response in plants originated from Shade habitat in Vrsac population. This study showed that not only populations, but also subpopulations occupying different habitats can differ genetically in their plastic response to density, and that between habitat differences can be population-specific.

Genetic Variation↗
PubMed1990

[A new balloon-expandable plastic endoprosthesis. Initial report of experience with the malleable thermostent].

A new system of balloon-expandable stents for different purposes is presented. A special plastic material that can be shaped by a hot balloon technique or other internal or external heating modalities has been developed. The plastic material - a distant derivative of polyurethane - is caprolactone, which is soft from 52 degrees C to 70 degrees C. Using balloon techniques, the "thermo-stent" can be modeled to suit the form of the vessels, the bile ducts or the bronchial tree, as required. The balloon can be heated simply by means of a warm NaCl solution, electric matter in the balloon itself or microwaves. The plastic material can even be heated directly, which is especially beneficial if the stent needs to be thicker, e.g. in the bronchial tree, by an electric network within the plastic material, which heats the material to the necessary temperature by electric current. When the balloon is cooled after the dilatation the new form, the plastic has been modeled to is maintained exactly. The advantages of this thermo-stent will be the perfect adaptation to every individual situation in the intraluminal vessels, the bile ducts, and even the bronchi. The problems encountered hitherto with conventional metallic stents, e.g. high thrombogenicity, risk of metal intoxication or metallic rupture of filaments, have not be seen so far in animal experiments.

Animals↗
PubMed1989

A comparative study of morphometric measurements of nucleoli in uveal melanomas from electron micrographs and plastic-embedded and paraffin-embedded sections.

Morphometric measurements of nucleoli were done on uveal melanomas from surviving and nonsurviving patients. The melanomas were embedded in paraffin and plastic, and measurement data from Papanicolaou-stained paraffin-embedded sections, toluidine blue-stained plastic-embedded sections and scanning transmission electron micrographs (STEM) of plastic-embedded sections were compared. The results showed that one parameter, the coefficient of variation (CV) of nucleolar area, correctly classified 80% of the cases as to survival when plastic-embedded material was used and 70% of the cases when paraffin-embedded material or STEM micrographs were used. The inverse standard deviation of the nucleolar area was a better predictor of outcome than was the CV of nucleolar area only in the paraffin-embedded sections. The nucleolar measurements were most easily and rapidly performed in the plastic-embedded sections.

Humans↗
PubMed1979

[Intraoperative evaluation of the high pressure zone in anti-reflux plastic operations].

It has been done a manometric intraoperating study on 18 patients (7 acalasical megaoesophagi, 6 herniae of hiatus, 5 duodenal ulcers) who had undergone an operation of modified Dor's anti-reflux plastics. After Haller H.P.Z. pressure has gone down of 13 mmHg, and has gone up again of 5,5 mmHg after modified Dor; after plastics H.P.Z. average intraoperating pressure has been of 18 mmHg. The posterior plastics of hiatus and the reconstruction of His' angle for hernia of hiatus modify scarcely H.P.Z. pressure. During a superselective vagotomy we have recorded a modest reduction of H.P.Z. pressure, of which average intraoperating values after vagotomy and anti-reflux plastics have been of 16,5 mmHg. At a distance of 30 months from the operation it has been done a follow up on 70% of patients that had undergone an operation of anti-reflux plastics and also 18 patients that had had en intraoperating inspection. However it has been, a degradation of manometric values, the results have been satisfactory over 90% of cases. The authors insist on the utility of intraoperating manometry for a valuation of the completenes and the efficacy of the operation.

Adolescent↗
PubMed1980

Availability of diazepam from plastic containers.

The effect of plastic intravenous containers and volume-control administration sets on diazepam availability was studied. Solutions of diazepam in dextrose 5% in water and in 0.9% sodium chloride were prepared in plastic burette chambers and polyvinyl chloride (PVC) bags. Diazepam concentration was measured spectrophotometrically for (1) samples taken from the burette chamber and from the end of the administration set, (2) samples prepared in glass beakers and then infused through plastic administration sets with 0.5-micron filters, (3) samples prepared in PVC bags, and (4) sections of the PVC bags and volume-control sets in which diazepam solutions were prepared and infused. Two hours after admixture, diazepam concentration was significantly reduced in the burette chamber (p less than 0.05). Diazepam concentration was reduced by about 55% after infusion through administration sets (p less than 0.0005) and after two hours of storage in PVC bags. About 24% of the diazepam concentration was recovered from the volume-control set (none was detected in the filter) and 49-56% was recovered from the PVC bags. Admixture of diazepam solutions in plastic containers and administration through plastic administration sets will significantly reduce their diazepam concentrations.

Diazepam↗
PubMed2026

The global potential of freshwater microbes for plastic degradation.

Plastic pollution is becoming increasingly severe on a global scale, and the potential for biodegradation as a treatment method that is environmentally friendly merits greater attention. A significant number of genes that associated the degradation of plastic (PDAGs) have been identified, however, the distribution of these genes among microorganisms in global inland waters remains to be elucidated. A global-scale meta-analysis was conducted, incorporating approximately 1000 metagenome datasets of inland waters across seven continents. A total of 13,109 metagenome-assembled genomes (MAGs) were obtained by means of metagenomics binning, and 22,621 PDAGs were identified from these. Among these recognized PDAGs, phenylacetaldehyde dehydrogenase (PAD) was the most dominant (n = 16,664), followed by catalase (n = 5931). The predominant hosts for PAD and catalase were identified as Gamma-proteobacteria and Bacteroidia, respectively. The largest number of both PAD and catalase was found in MAGs from North America, while the average gene number in single MAG was highest in MAGs from Oceania. In accordance with the prediction of traits, PDAG-carrying MAGs from Europe demonstrated the fastest growth rate and the lowest optimal growth rate. Furthermore, 25 styrene monooxygenase (StyA) enzymes were identified, which were found to cluster into two distinct groups hosted by Alpha-proteobacteria and Gamma-proteobacteria, respectively. Moreover, 11 MAGs were observed to possess the complete pathway of polystyrene degradation. These results explored the potential of inland water microorganisms as a biological resource for plastic degradation and provided valuable microbial reference information that can be used to develop biological treatment technologies for mitigating plastics.

Plastics↗
PubMedDate not supplied

Improvements in histological quality and signal retention following in situ hybridization in early chick embryos using plastic resin and recolorization.

We describe a novel method that allows reliable detection of in situ hybridization signals in thin sections of plastic embedded embryos. Sections from plastic embedded embryos are thinner and have superior histological quality compared to paraffin, gelatin, agarose embedded sections or cryosections; however, plastic resin traditionally has not been used as an embedding medium following in situ hybridization because of loss of signal. When signal is detected with alkaline phosphatase and NBT/BCIP, the resulting colored precipitate is subject to fading when samples are exposed to organic compounds. The colored precipitate can be redeposited by repeating the NBT/BCIP reaction following plastic sectioning. This recolorization shows no loss of specificity, because signal is detected only where the anti-digoxigenin/alkaline phosphatase conjugated antibody is bound to the riboprobe. Strong signals can be detected without recolorization; however, weaker signals require the recolorization step. This novel method of re-depositing colored precipitate after processing and sectioning allows accurate determination of the location of gene expression and study of this expression in high quality histological sections of early chick embryos.

Alkaline Phosphatase↗
PubMedDate not supplied

Duration of anesthesia as an indicator of morbidity and mortality in office-based facial plastic surgery: a review of 1200 consecutive cases.

OBJECTIVE: To define whether duration of anesthesia is an indicator of patient morbidity and mortality in facial plastic surgery performed in an accredited office-based surgical facility. DESIGN: A prospective and retrospective outcomes analysis of 1200 consecutive patients who underwent facial plastic surgery from July 1995 to February 2005. Outcomes of patients who underwent surgery with anesthesia for less than 240 minutes were compared with those of patients who underwent surgery with anesthesia for more than 240 minutes. RESULTS: Of the 1200 cases analyzed, in 1032 (86%), duration of anesthesia was longer than 240 minutes. There were no deaths and no cases of myocardial infarction or pulmonary embolism in this study group. Morbidity in the 1200 cases was reported as follows: 1 case of respiratory failure, 1 case of central nervous system deficit, 1 case of adverse reaction to medication, and 1 case that required transfer to a hospital. There were 6 cases of prolonged recovery from anesthesia. Incidences of major morbidity in the group of 168 patients (14%) whose anesthesia lasted less than 240 minutes were the same as in the group whose anesthesia lasted more than 240 minutes. CONCLUSIONS: In an accredited office-based facial plastic surgery facility, anesthesia duration is not an indicator of patient morbidity and mortality. Combined facial plastic surgery procedures, using general anesthesia, can be accomplished safely in the office-based environment, and inpatient care would not have altered morbidity in this study group.

Adolescent↗