Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “quantitative analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources
PubMed1994

[Quantitative analysis of glycosaminoglycans in tear fluids during corneal epithelial wound healing in rabbits].

We performed quantitative analyses of glycosaminoglycans in the tear fluids in a rabbit wound healing model. We ablated rabbit corneal epithelium with trephine and spatula, and sampled tear fluids before the epithelial ablation, and at 3, 24, 48, and 72 hours after it. After an instillation of 200 microliters saline solution in the conjunctival sac, as much tear fluid as possible was collected from the lower cul-del-sac. The glycosaminoglycans in the tears were then treated with chondoroitinase ABC to make fractions of disaccharides. The quantities of disaccharides were determined with high-performance liquid chromatography as weight per unit protein in the tears. The concentrations of delta Di-HA in the tear fluids at 3 and 24 hours were significantly higher than those before the treatment and returned to the initial value at 72 hours after making the epithelial wound. Among the disaccharides of chondroitin sulfate, delta Di-0S and delta Di-6S showed a significant increase at 3 hours after the treatment but delta Di-4S did not show any significant variation. The results suggest that the glycosaminoglycans in the rabbit tear fluids may play an important role in the corneal epithelial wound healing process.

Animals↗
PubMedDate not supplied

The inverted Z bunionectomy: quantitative analysis of the scarf and inverted scarf bunionectomy osteotomies in fresh cadaveric matched pair specimens.

Quantitative analyses of the Scarf/Z and inverted Scarf/Z bunionectomy osteotomy procedures utilizing two-screw fixation were performed in fresh cadaveric specimens. Eighteen trials (nine matched pair feet) were used for direct comparison. Ultimate strength and failure areas were examined. Trial results revealed a strong statistically significant positive effect. The inverted Z approach was found, on average, 1.6 times stronger in resisting simulated weightbearing forces on the capital fragment to failure than that of the traditional Z bunionectomy osteotomy.

Aged↗
PubMed1994

[Quantitative analysis of hepatitis C virus RNA by competitive nested PCR].

A method that allows the quantitation of hepatitis C virus (HCV) RNA is described. The RNA was extracted from serum sample and reverse transcribed. Target cDNA was then co-amplified by nested polymerase chain reaction with a known amount of competitive template at various concentrations. Since this internal control DNA uses the same primers as those of the target and is distinguishable from the target cDNA after amplification by size, the initial concentration of the target could be estimated by comparing the intensity of the two bands of amplified DNA fragment. That is, if the starting amount of the cDNA and the competitive template are equal, the intensity of the two bands should also be equal.

Genotype↗
PubMed1993

Quantitative analysis of anti-CEA antibody accumulation in human colorectal carcinomas.

In order to obtain quantitative data on intratumoral antibody accumulation we analyzed resected colorectal adenocarcinomas of 25 patients who had undergone immunoscintigraphy 4-14 days earlier. All had been injected with 0.5-1.0 mg intact anti-CEA antibody (BW 431/26) labelled with 70-80 MBq131I. Correlation of tissue radioactivity concentrations with tumor characteristics revealed significantly higher values in necrotic compared to viable as well as in CEA-positive compared to CEA-negative viable tumor tissue indicating action of both specific and unspecific uptake mechanisms. In contrast, diagnostic results of immunoscintigraphy were influenced by tumor size only. 11 of 12 false-negative findings were obtained in tumors < 4 cm in diameter. Since ex-vivo scintigraphy of resected specimens correctly visualized all but one of these lesions, it is concluded that technical limitations of scintigraphy are the main cause of negative results of radioimmunoimaging with 131I-labelled antibodies.

Adenocarcinoma↗
PubMed1986

Quantitative analysis of left ventricular function by cold pressor two-dimensional echocardiography in patients with coronary artery disease.

Quantitative assessment of left ventricular function in patients with coronary artery disease was made by computer analysis of two-dimensional echocardiography performed during a cold pressor test. Short-axis cross-sectional images of the left ventricle at the levels of the mitral valve and chordae tendineae were recorded by a phase array sector scanner in 12 patients with coronary artery disease and 11 normal controls. Endocardial outlines at end-diastole and end-systole were traced and analyzed by a computer system. The short-axis cross-sectional images were divided into octants and were analyzed. The segmental area and its changes during the cardiac cycle were measured and calculated for each octant. Regional function of the left ventricle was evaluated by percent changes of segmental area. The regional segmental area changes in patients with coronary artery disease were compared with those in normal controls. Similar increments were achieved in rate pressure product in the 2 groups. In relation to the perfusing coronary arteries, 8 segments were integrated arbitrarily into 3 walls (anteroseptal wall, lateral wall, and posterior wall and posterior septum). The cold pressor test induced wall motion abnormalities in 12 of 16 walls which were supplied by stenosed coronary arteries. In contrast, wall motion abnormalities were detected in only 5 of 38 walls which were supplied by coronary arteries without significant stenotic lesions. The sensitivity of cold pressor test-induced wall motion abnormalities in detecting coronary artery disease was 75% and the specificity was 87%. No serious complications were encountered in this study. In conclusion, computer-aided cold pressor two-dimensional echocardiography is a safe and sensitive method for the assessment of left ventricular function and diagnosis of coronary artery disease.

Adult↗
PubMed1999

Quantitative analysis of the functionality and efficiency of three surgical dissection techniques: a time-motion analysis.

The increasing technological complexity of surgery demands objective evaluation of surgical techniques. In particular, alternatives for laparoscopic ligation, such as monopolar coagulation and the relatively new bipolar scissors combining dissection with coagulation, should be analyzed and compared. This study tests the efficacy of quantitative time-motion analysis in evaluating and comparing the functionality and efficiency of dissection and ligation techniques in a clinical setting. Standard dissection with ligation of vessels, bipolar scissors, and monopolar coagulation were consecutively applied to dissect 4 of the small bowel mesentery of pigs, in random order. All actions performed were recorded and analyzed, using a standard action list. The efficiency of each technique was expressed in mean dissection time and number of actions, and the safety in occurrence of complications and severity of microscopic damage. Time-motion analysis evaluated the efficiency objectively and reproducibly (ICC 0.98). Bipolar scissors were significantly more efficient (time 7 +/- 2 min, actions 129 +/- 33) than the standard technique (28 +/- 6, 771 +/- 185) and monopolar coagulation (14 +/- 5, 368 +/- 32) (p < 0.01). Furthermore, bipolar coagulation needed significantly less recoagulation of an oozing vessel (0.5% of the total dissected vessels) than did monopolar coagulation (10.4%), and the damaged zone was significantly smaller (p < 0.05). Significantly less time was spent waiting or exchanging instruments with bipolar scissors than with the standard technique (p < 0.05). This time-motion analysis objectively compared the efficiency and functionality of three surgical dissection techniques during clinical use. Bipolar scissors were more efficient than were both other techniques, and they coagulated vessels more safely than did monopolar coagulation.

Animals↗
PubMed1983

The interaction of 125I-insulin with cultured 3T3-L1 adipocytes: quantitative analysis by the hypothetical grain method.

The murine 3T3-L1 fibroblast under appropriate incubation conditions differentiates into an adipocyte phenotype. This 3T3-L1 adipocyte exhibits many of the morphologic, biochemical, and insulin-responsive features of the normal rodent adipocyte. Using quantitative electron microscopic (EM) autoradiography we find that, when 125I-insulin is incubated with 3T3-L1 adipocytes, the ligand at early times of incubation localizes to the plasma membrane of the cell preferentially to microvilli and coated pits. When the incubation is continued at 37 degrees C, 125I-insulin is internalized by the cells and preferential binding to the villous surface is lost. With the internalization of the ligand, two intracellular structures become labeled, as determined by the method of hypothetical grain analysis. These include large clear, presumably endocytotic, vesicles and multivesicular bodies. Over the first hour of incubation the labeling of these structures increases in parallel, but in the second hour they diverge: the labeling of multivesicular bodies and other lysosomal forms continuing to increase and the labeling of large clear vesicles decreasing. At 3 hours limited but significant labeling occurs in small Golgi-related vesicles that have the typical distribution of GERL. The distinct morphologic features of this cell make it ideal for a quantitative morphologic analysis and allow for an unambiguous view of the sequence of events involved in receptor-mediated endocytosis of a polypeptide hormone. These events are likely to be representative of the processing of insulin by the mature rodent adipocyte.

Adipose Tissue↗
PubMedDate not supplied

Method for identification and quantitative analysis of protein lysine methylation using matrix-assisted laser desorption/ionization--time-of-flight mass spectrometry and amino acid analysis.

Protein methylation is a post-translational modification that might have important functional roles in cell regulation. We present a new technique with sufficient sensitivity (sub-pmol level) for analysis of methylation of proteins in abundances typically found on proteome maps produced by two-dimensional (2-D) gel electrophoresis. The method involves the identification and quantitation of lysine (Lys) methylation using Fmoc (9-fluorenylmethyl chloroformate)-based amino acid analysis (AAA). Tri- and monomethyl-Lys were baseline-separated from other amino acids using a modified buffer system. Trimethyl-Lys was quantitatively recovered after acid hydrolysis and AAA of two known methylated proteins - yeast cytochome c and human calmodulin. The methylated peptides from tryptic digestion of those two proteins were identified by high sensitivity matrix-assisted laser desorption/ionization - time-of-flight (MALDI-TOF) mass spectrometry (MS). An automated mass-screening approach is proposed for the study of various post-translational modifications to understand the distribution of those protein isoforms separated by two-dimensional polyacrylamide gel electrophoresis. It is concluded that the combination of AAA and MALDI-TOF-MS provides a high sensitivity quantitative tool for the analysis of protein post-translational methylation in the context of proteome studies.

Amino Acid Sequence↗
PubMed2002

Quantitative analysis of correlation between number of nuclear plasmids and gene expression activity after transfection with cationic liposomes.

PURPOSE: A quantitative understanding of the intracellular trafficking of plasmids delivered by nonviral vectors is essential for optimizing vector functions to increase their transfection efficiency. In this study, quantitative methods were developed to measure plasmids delivered to the nucleus, and the relationship between transfection activity and the number of plasmids in the nucleus were analyzed. METHODS: AH130 cells were transfected with plasmids in cationic liposomes at various doses. The nuclear fraction was isolated after NP-40 lysis. and the unincorporated plasmids were enzvmatically degraded and washed away. Intranuclear plasmids were amplified by quantitative PCR. and the number of plasmids was determined. Plasmid amounts in the nucleus were also measured by Southern analysis to confirm the quantification. RESULTS: Both methods led to similar results in measuring the nuclear plasmids within the same order of magnitude. A remarkable saturation was found for transfection activity vs. number of plasmids in the nucleus, whereas no saturation was observed in nuclear-delivered plasmids vs. dose. CONCLUSIONS: These results clearly demonstrate the importance of the quantitative measurement of intracellular trafficking of plasmids after transfection. The findings herein described suggest that efficient transgene expression as well as enhanced nuclear delivery is required in order to achieve the maximal transfection activity of nonviral vectors.

Animals↗
PubMed1982

Quantitative analysis of the cytokinetic response of KHT tumors in vivo to 1-beta-D-arabinofuranosylcytosine.

Quantitative estimates of cytokinetic perturbations induced over a 30-hr interval in KHT tumor cells in vivo by a single dose of 1-beta-D-arabinofuranosylcytosine (ara-C) were inferred from measurements of DNA distribution sequences, tritiated thymidine incorporation into tumor cell DNA, and radioactivity of cells labeled with tritiated thymidine prior to treatment with ara-C. These data were analyzed collectively to produce a mathematical model describing the effects of ara-C on tumor cell cycle kinetics. During analysis, we postulated that ara-C produced a transient block at the a G1-S-phase boundary, that ara-C killed all cells in S phase, and that the cells killed by ara-C did not cycle after treatment. The analysis showed that the duration of the G1-S-boundary block was 5.5 hr, that cells were recruited from G0 into cycle beginning 5.5 hr posttreatment, and that the G1, S, and G2M phase durations of the clonogenic cells which were initially 2, 11.5, and 2 hr, respectively, changed to 0.8, 4.6, and 0.8 hr at 14 hr posttreatment. Cells killed by ara-C were removed from the tumor beginning 10 hr posttreatment. We then used the mathematical model to predict clonogenic tumor cell survival following a second dose of ara-C administered at time intervals ranging from 1 to 30 hr after the first treatment. Clonogenic tumor cell survival following the second dose of ara-C was then experimentally determined and agreed well with the model predictions.

Animals↗
PubMed1989

Quantitative analysis of the effect of colony-stimulating factors on human marrow progenitor growth in liquid-suspension cultures: application of limiting dilution assay.

Proliferation of human marrow progenitors in liquid cultures can be quantitated by limiting dilution clonal analysis (LDA) of progenitors in microwells. In this study, we have used LDA to study the effect of purified native or recombinant granulocyte colony-stimulating factors (G-CSFs) and recombinant granulocyte-macrophage CSF (GM-CSF) on progenitor growth. These results were compared to those of simultaneous cultures in methylcellulose. In LDA, single-hit kinetics were obtained with up to 500 U/ml of the recombinant preparation. In LDA with recombinant GM-CSF, progenitor growth conformed to single-hit kinetics from 100 to 2000 U/ml with maximum progenitor frequency at 500 U/ml. In simultaneous methylcellulose cultures with recombinant GM-CSF, colony formation reached a plateau at 100 U/ml. In LDA, purified native G-CSF was shown to support progenitor growth with single-hit kinetics at 100 U/ml, but at greater concentrations (greater than 150 U/ml), it suppressed progenitor growth with almost complete inhibition at a concentration of 200 U/ml. However, this dose-response effect was not observed in either simultaneous methylcellulose culture with G-CSF or in LDA with a purified recombinant preparation of the corresponding G-CSF. In methylcellulose cultures, colony formation reached a maximum at 100 U/ml and maintained a plateau up to 1000 U/ml. Hence, liquid culture allowed detection of contaminating suppressive activity in the G-CSF preparation that was not detected by methylcellulose assay. LDA may be more sensitive than methylcellulose culture for screening factors regulating human hematopoietic cell growth.

Bone Marrow↗
PubMed2005

Methods of quantitative analysis of the nitric oxide metabolites nitrite and nitrate in human biological fluids.

In human organism, the gaseous radical molecule nitric oxide (NO) is produced in various cells from L-arginine by the catalytic action of NO synthases (NOS). The metabolic fate of NO includes oxidation to nitrate by oxyhaemoglobin in red blood cells and autoxidation in haemoglobin-free media to nitrite. Nitrate and nitrite circulate in blood and are excreted in urine. The concentration of these NO metabolites in the circulation and in the urine can be used to measure NO synthesis in vivo under standardized low-nitrate diet. Circulating nitrite reflects constitutive endothelial NOS activity, whereas excretory nitrate indicates systemic NO production. Today, nitrite and nitrate can be measured in plasma, serum and urine of humans by various analytical methods based on different analytical principles, such as colorimetry, spectrophotometry, fluorescence, chemiluminescence, gas and liquid chromatography, electrophoresis and mass spectrometry. The aim of the present article is to give an overview of the most significant currently used quantitative methods of analysis of nitrite and nitrate in human biological fluids, namely plasma and urine. With minor exception, measurement of nitrite and nitrate by these methods requires method-dependent chemical conversion of these anions. Therefore, the underlying mechanisms and principles of these methods are also discussed. Despite the chemical simplicity of nitrite and nitrate, accurate and interference-free quantification of nitrite and nitrate in biological fluids as indicators of NO synthesis may be difficult. Thus, problems associated with dietary and laboratory ubiquity of these anions and other preanalytical and analytical factors are addressed. Eventually, the important issue of quality control, the use of commercially available assay kits, and the value of the mass spectrometry methodology in this area are outlined.

Humans↗
PubMedDate not supplied

Quantitative analysis of proliferation, apoptosis, and angiogenesis in retinoblastoma and their association with the clinicopathologic parameters.

PURPOSE: Quantitative analyses of proliferation, apoptosis, and angiogenesis, which may be important for the prognosis of retinoblastoma, were performed and possible associations with some well-known clinicopathologic parameters were investigated. METHODS: Fifty-three pathology specimens (43 enucleations, 10 exenterations) were evaluated by immunohistochemical methods. The proliferative index was detected by Ki67 antibody staining. The apoptotic index was calculated by the in situ terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method, and angiogenesis was detected by CD34 antibody staining. RESULTS: The mean proliferative index was 37.63+/-11.12, the mean apoptotic index was 2.67+/-1.18, and the microvessel density and mean vascular area were determined as 3.14+/-1.4 and 38.73+/-12.70, respectively. Statistical analysis showed that the proliferative index was directly proportional to the tumor dimensions (P=.001). In addition, the tumor dimensions were larger in cases where the apoptotic index was below 2.4% (P=.011). In cases where the apoptotic index was over 2.4%, no metastasis was observed and also a lower proliferative index was found (P=.014). CONCLUSIONS: Proliferation appears to be more important than apoptosis and angiogenesis in determining the tumor dimensions. The apoptotic index may be an important predictor of metastasis, and may be useful in the follow-up of bilateral cases with 1 eye enucleated.

Apoptosis↗
PubMed2006

ST-segment depression in non-ST elevation acute coronary syndromes: quantitative analysis may not provide incremental prognostic value beyond comprehensive risk stratification.

BACKGROUND: It is unclear whether quantitative ST-segment assessment can improve risk stratification of unselected acute coronary syndrome (ACS) patients using the validated Global Registry of Acute Cardiac Events (GRACE) risk model. METHODS: In the prospective, multicenter, Canadian ACS Registry, the admission electrocardiogram was evaluated centrally at a blinded core laboratory. Patients with ST-elevation myocardial infarction and other electrocardiogram confounders were excluded. ST depression (ST down) was measured and summed in all leads except aVR. Patients with ST down were divided into 3 groups based on tertiles of cumulative ST down. A multivariable model was developed to examine the independent prognostic value of ST down severity after adjusting for other known prognosticators in the GRACE risk model. RESULTS: Among 2590 patients with non-ST-elevation ACS, more severe ST down was associated with advanced age, higher heart rate and Killip class, elevated creatinine, abnormal biomarkers, higher GRACE risk score, and higher 1-year mortality (all P < .001). After adjusting for these confounding prognosticators, the presence of any ST down remained independently associated with higher 1-year mortality (odds ratio 1.78, 95% CI 1.21-2.63, P = .004). However, the gradient of risk with increasing magnitude of ST down was no longer evident (adjusted odds ratios 1.77, 1.77, 1.81, for ascending tertiles of cumulative ST down, respectively). Moreover, quantitative ST down did not improve the model discrimination for 1-year mortality. The results were similar when the number of leads with ST down or the maximum magnitude of ST down was analyzed, after adjusting for tertiles of GRACE risk score or inhospital revascularization, or using the composite end point of death or myocardial (re)infarction at 1 year. CONCLUSIONS: Greater ST down is associated with other adverse prognosticators across the broad spectrum of non-ST-elevation ACS. Although the presence of any ST down is an independent predictor of 1-year mortality, its quantitative assessment is not as important as its mere presence when studied on the background of comprehensive clinical and biomarker evaluation in a nonclinical trial-based ACS population.

Aged↗
PubMed1980

A qualitative and quantitative analysis of tertiary amines in restorative resins.

Previous investigations have shown that the type and the quantity of tertiary amine influence the properties of restorative resins. It was the purpose of the present work to analyze qualitatively and quantitatively the amines in commercial restorative resins. The amines were extracted with hydrochloric acid from chloroform solutions of the monomers. For the qualitative analysis the acid amine solution was made alkaline, the amine extracted with methylenechloride and isolated. The method of analysis was NMR-spectroscopy. The quantitative determination was performed by means of UV-spectra of the acid amine solutions. Sixteen brands were investigated, and three species of amine were identified. The amount of amine varied between 0.3% and 4% by weight of the monomer. Iit is probable that the information obtained will lead to a better understanding of the nature of restorative resins.

Amines↗
PubMed1985

Quantitative analysis of visna virus replication in vivo.

Visna virus is the prototype of the lentivirus subfamily, a group of nontransforming retroviruses that cause slow infections in sheep and goats. In nature, virus is acquired primarily by the respiratory route and subsequently spreads to several organ systems. These viruses persist for years in their hosts despite a vigorous immune response because of a block in virus gene expression. This report continues the analysis of persistence in vivo, and specifically examines a gene dosage hypothesis that has been advanced as an explanation for the decrease in transcription and virus production in the cells in infected animals. For this analysis a new pulmonary model has been developed that, in conjunction with quantitative in situ hybridization, provides an opportunity to examine in animals the molecular events that occur in the course of the viral life cycle. We establish the feasibility of such a longitudinal analysis in vivo, document restriction in gene expression in alveolar macrophages and provide evidence that this restriction cannot be accounted for simply by gene dosage. The approach illustrated with visna should be of general applicability to other dynamic and molecular investigations of virus infection.

Animals↗
PubMed1996

Flow cytometric detection and quantitative analysis of the GM-CSF receptor in human granulocytes and comparison with the radioligand binding assay.

A flow cytometric method to quantify the Granulocyte-macrophage colony-stimulating factor receptor (GM-CSFr) on human cells is described. The number of GM-CSFr binding sites on human neutrophils was assessed by using different bead standards. Results were compared with those from conventional receptor quantification, which was performed by using the radioligand binding assay. A high degree of correlation was found between the two methods, although quantitative evaluation of GM-CSFr expression on neutrophils performed by flow cytometry revealed a somewhat higher number of receptor molecules per cell than with that determined by Scatchard analysis. By the flow quantitative approach, we measured the GM-CSFr on mobilized CD34-positive cells and obtained results similar to those of previously published data. Our data suggest that flow cytometric analysis is a simple and reproducible method to detect and quantify the presence of GM-CSFr per cell, thus allowing the study of receptor expression on different populations selected by gating on the basis of the scatter parameters and surface markers. This assay offers the possibility to quantify the presence of GM-CSFr on different subsets of normal and pathological cells even if samples are too small (such as CD34-positive progenitor cells) for measurement with the radioligand binding assay.

Antigens, CD34↗
PubMed2000

Colocalization of parvalbumin and somatostatin-like immunoreactivity in the mouse hippocampus: quantitative analysis with optical dissector.

The colocalization of parvalbumin (PV) and somatostatin (SS)-like immunoreactivity was studied quantitatively in the mouse hippocampus, with particular reference to their areal and dorsoventral differences. The optical disector method was applied by using a confocal laser scanning microscope with immunofluorescent double-labeling. In the present study, we found a particular subpopulation of hippocampal nonprincipal neurons that contained both PV and SS-like immunoreactivity, i.e., PV-immunoreactive (IR)/SS-like immunoreactive (LIR) neurons. In the CA1 region, PV-IR/SS-LIR neurons were restricted to the stratum oriens (SO). In the CA3 region, they were scattered in the SO, stratum pyramidale (SP), and stratum radiatum (SR). However, they were rarely seen in the dentate gyrus (DG). The proportion of PV-IR/SS-LIR neurons in the PV-IR neurons or SS-LIR neurons was about 10% in the CA1 region, 15-30% in the CA3 region, 0-5% in the DG, and 10-20% in total. Laminar analysis revealed that the proportions of PV-IR/SS-LIR neurons in the PV-IR neurons were high in the SO (about 25%) of the CA1 region, and in the SO (about 50%) and SR (30-45%) of the CA3 region. The proportion of PV-IR/SS-LIR neurons in the SS-LIR neurons was low in the SO of the CA1 region (about 10%), but high in the SO (35-65%) and SR (35-45%) of the CA3 region. Morphologically, medium-sized horizontal fusiform and multipolar PV-IR/SS-LIR neurons were frequently observed, and they showed weak immunoreactivity for PV. Large-sized vertical bitufted and triangular PV-IR neurons lacked SS-like immunoreactivity, and most of them showed moderate to intense immunoreactivity for PV. In addition, we provide direct evidence that some PV-IR/SS-LIR neurons projected to the medial septum by using retrograde labeling with Fluoro-Gold injection. These observations indicate that PV-IR/SS-LIR neurons constitute a particular subpopulation of hippocampal nonprincipal neurons.

Animals↗