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Results for “Experimental validation”

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At least 361 records · Page 20Linked to original sources
PubMedDate not supplied

[An experimental validation of the transplantation of an orthotopic allograft together with tooth roots for the replacement of mandibular defects].

The results of transplantation of surface-demineralized, lyophilized, and formalin-treated orthotopic allotransplants, including dental roots, to 40 dogs [correction of rats] are analyzed. Clinical, x-ray, and morphologic studies have demonstrated that formalin-treated allotransplants are the optimal plastic material, providing restoration of bone intactness, preservation of dental roots, and the osteoid type of dental root join with the bone regenerate. Dental roots within surface-demineralized and lyophilized allotransplants are resolved in the course of their replacement with newly developing bone tissue.

Animals↗
PubMedDate not supplied

[An experimental validation of immunotherapy with purified staphylococcal anatoxin].

Inbred mice have proved to be a promising model for the evaluation of antigen-specific and antigen-nonspecific immunomodulating activity of purified staphylococcal toxoid in humans. This toxoid induces the formation of pronounced humoral response to homologous and heterologous infections in humans and mice. In animal experiments purified staphylococcal toxoid has shown its capacity for the correction of secondary immune deficiency of different origin; when introduced into humans having secondary immunodeficiency associated with bacterial infections of different etiology, the preparation reproduces this effect.

Acute Disease↗
PubMed1994

[The clinico-hygienic and experimental validation of the nosology of laser-induced disease].

Analysis of literature and the authors' own data suggest that laser-induced occupational disease may be diagnosed in following disorders on the part of: vision--deterioration of light and colour perception, pain and feeling of burning in the eyes; central nervous system--vegetative dysfunction, hypo- or hypertonic neuro-asthenic syndrome manifesting in weakness and fatiguability; cardiovascular system--cardialgias, hypo- or hypertonic neurocirculatory dystonia, hypertonic disease, general weakness, headache; blood--reticulocytosis; enzymes--increase of base phosphatase activity in blood. The whole complex of aforementioned disorders is quite rate (1.5-2% of cases). As a rule, only some of them are evident while sight disorders, vegetative dysfunction and increased activity of base phosphatase predominate.

Animals↗
PubMed1993

[Intravascular echographic imaging: experimental validations and limits. An in vitro study].

Intravascular ultrasound is a new method of visualizing details of vascular pathology, providing (real time) high resolution images of vascular walls. Most of the research on the technique has explored its qualitative and quantitative capabilities to improve the assessment of atherosclerotic vascular disease in vivo. Intravascular ultrasound differs from angiography and angioscopy in its ability to penetrate below the surface of the vessel lumen, demonstrating specific appearances of the distribution and composition of plaque. Image analysis is operator dependent. Although this technology is very promising limitations such as artefacts and loss of image quality in heavily calcified vessels hinder its use. There is hope that this imaging technique may ultimately improve the results of endovascular interventions.

Arteries↗
PubMed1994

[Experimental validation of the efficacy of laser-magnetic therapy for chronic placental insufficiency].

A new pathogenetically based non-medicamentous method for correction of uteroplacental bloodflow disturbances has been developed on the model of chronic placental insufficiency in rats. A single 5 min laser-magnetic exposure on day 21 of normal pregnancy resulted in a vasodilating effect with reduction of the peripheral resistance in the uterine horn vessels and with improvement of their blood supply. A new LAMA laser magneto-therapeutic device was employed. Daily 5 min sessions of laser magnetic therapy administered to rats with chronic placental insufficiency from pregnancy days 15-16 to 21 normalized uterine horn contractility and resulted in positive morphofunctional changes in the components of the uterine horns and placenta, being associated with a noticeable improvement of fetal functions. Hence, laser magnetic therapy may be regarded as an effective non-drug method for therapy of chronic placental insufficiency.

Animals↗
PubMedDate not supplied

[Experimental validation of the administration into the body of the lipids from therapeutic muds by means of vibration].

Infrared and ultraviolet spectroscopy were used to study the ability of therapeutic mud lipids to penetrate through the animal skin when compress or vibration were used. Vibrophoresis appeared to be 1.5-fold more effective compared to compress in improving skin permeability. It promotes entering the body for biologically active compounds containing heteroatoms: oxygen, nitrogen, sulfur, phosphorus, high-molecular acids, spirits, ethers, chlorophils, sulpho- and phospholipids.

Administration, Cutaneous↗
PubMed1996

[The experimental validation of the potential use of hydroxyapatite-containing preparations for the obturation of the dentin tubules in prepared teeth].

Ultramicroscopic hydroxyapatite (UMHA) was used for obturation of dentine tubules of prepared teeth in dog experiments. Scanning electron microscopy showed that amorphous layer on the tooth surface prevents the penetration of UMHA in the tubules. This layer is not removed by the traditional treatment with alcohol and ether. Exposure of dentin to primer sintac altered the amorphous layer, but did not completely remove it. Solutions consisting of 10% citric acid and 3% iron chloride or 10% EDTA completely removed the amorphous layer in 1 min and permitted hydroxyapatite penetrate in the dentin canaliculi and obturate them. The agent more effectively penetrates in the dentin tubules of vital teeth than of pulp-free ones.

Animals↗
PubMedDate not supplied

[Experimental validation of the use of betamecil in ophthalmology].

Wound-healing activity of 2% betamicil ointment in comparison with the traditional stimulants of corneal repair regeneration (methyluracyl and solcoseril) was studied in experiments. The rate of epithelialization of a standard trephination wound in rabbit cornea (28 animals), mitotic activity of the anterior corneal epithelium, and strength of the regenerated tissue were assessed after use of different stimulants and in control. A maximal positive effect of local betamicil (2% ointment) was observed: the wounds epithelialized 57% sooner than in control, but there was no reliable difference from solcoseril; the regenerate of linear corneal wound was 1.5 times stronger. Use of this ointment in ophthalmology is validated.

Animals↗
PubMed1997

[A clinical and experimental validation of the use of Stimuloss in patients with chronic generalized periodontitis].

The pharmacological effect of hydroxyapatite and a composition based on it in the form of Stimulos sponge has been studied in human osteogenic tissue culture. Hydroxyapatite stimulated the biosynthetic processes in the cells. Addition of chlorohexidine and thymogen to the composition in order to increase its antibacterial activity did not decrease the osteoinductive properties of the drug. Trials of Stimulos in 66 patients with chronic generalized periodontitis demonstrated its high efficacy, particularly of the compositions containing immunostimulants: inflammation disappeared and the height of alveolar osseous tissue increased, as did bone compactness.

Adjuvants, Immunologic↗
PubMedDate not supplied

[A new theoretical and experimental validation of the treatment and prevention of cholelithiasis].

Approaches are proposed, new in principle, toward breaking biliary calculi into pieces, as well as toward prophylaxis of cholelithiasis. Exposure of the concrements to ultrasound with varying resonance frequency in a contact medium containing litholytic substances permits bringing about their reduction to fragments being safe for their evacuation from the biliary system. Prevention of cholelithiasis involves identification of precalculous period and exposure of the gallbladder region to vibration along with adopting conventional therapy.

Bile↗
PubMedDate not supplied

[The methodology for the rapid experimental validation of hygienic standards for xenobiotics in different environments].

Correlation- and regression analyses were carried out of relatedness of industrial chemical substances and pesticides LD50 (LC50) to their maximum allowable concentration in the air of the working environment and permissible diurnal doses in enteral route (according to the standard basis of the nineties). Highly reliable regression equations have been derived, which can be made use of in practice provided acute and subacute experiments aimed at determining LD50 (LC50) and complex (qualimetric) assessment of cumulative properties of the studied substances will be carried out.

Animals↗
PubMedDate not supplied

[The methodology for the rapid experimental validation of hygienic standards for xenobiotics in different environments (2)].

Based on standards set up in the 1990s correlation and regression analyses were performed of relationship between maximum permissible concentration (MPC) of xenobiotics in the air of the working environment and their MPCs in the atmospheric air, water bodies (with these being recognized as health hazard from hygienic-and-toxicological standpoints) or allowable diurnal dose. Highly reliable equations of regression were obtained that rely on preliminary determination of safe level of exposure in the air of the working environment and oral-and-inhalation coefficient on the level of standards set up by results of acute and subacute experiments.

Air Pollutants, Occupational↗
PubMed2007

Assessment of endoleak significance after endovascular repair of abdominal aortic aneurysms: a lumped parameter model.

The outcome of endovascular repair of abdominal aortic aneurysms (AAAs) is greatly compromised by the possible occurrence of endoleak. Previously, the causes and effects of endoleak on a patient-specific basis have mainly been investigated in experimental studies. In order to both reconcile and physically substantiate the various experimental findings, a lumped parameter model of an incompletely excluded AAA was developed. After experimental validation, the model was applied to study the effects on the intrasac pressure of the degree of endoleak, the degree of stent-graft compliance, and the resistance of a possible outflow tract formed by a branching vessel. It is concluded that the presence of endoleak leads to elevated intrasac pressure, the mean of which is mainly governed by the outflow tract resistance, while the pulse pressure is governed by both the endoleak resistance and the stent-graft compliance. Based on the agreement of the current results with previous findings, it is further concluded that the lumped parameter modelling method provides a useful numerical tool for validating experimental endoleak studies.

Algorithms↗
PubMed2004

A comparison of methods for characterizing the event-related BOLD timeseries in rapid fMRI.

Information about the shape and temporal duration of the blood oxygenation level dependent (BOLD) response can inform both functional neuroanatomy and psychological theory. However, the BOLD response evolves over 20 s or more, making it difficult to distinguish the unique characteristics of the response evoked by temporally adjacent stimuli. Fortunately, event-related BOLD signals can be extracted given that there is adequate variance in the distribution of inter-stimulus intervals (ISI). Unfortunately, the ISI distribution that yields the highest statistical efficiency is not always optimal from a psychological perspective; variability in the stimulus timing may complicate the interpretation of neuroimaging data in terms of underlying cognitive operations. In the present paper, Monte Carlo simulations are used to evaluate two techniques for estimating the event-related BOLD timeseries-event-related averaging and deconvolution using the Ordinary Least Squares estimate -with respect to maintaining acceptable levels of statistical power and experimental validity. While the unbiased deconvolution technique more robustly estimates the shape of the BOLD response functions, both methods succeed in accurately re-producing known differences between evoked BOLD responses when the stimulus ordering is randomized. However, the deconvolution method is more effective at preserving differences when there are sequential dependencies in the stimulus presentation order and restricted ISI distributions are used; particularly if the second of two sequentially dependent stimuli is omitted on some portion of the trials. Importantly, the successful re-production of the evoked BOLD response using restricted ISI distributions often maximizes the ability to make psychologically valid experimental conclusions.

Brain↗
PubMed2005

Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data.

BACKGROUND: We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. RESULTS: Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. CONCLUSION: Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer.

Biomarkers, Tumor↗