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PubMed1996

Noninvasive quantification of regional myocardial metabolic rate of oxygen by 15O2 inhalation and positron emission tomography. Experimental validation.

BACKGROUND: The purpose of this study was to validate a novel method for noninvasive quantification of regional myocardial oxygen consumption (MMRO2, mL.min-1 x 100 g-1) and oxygen extraction fraction (OEF) by use of positron emission tomography (PET) and inhalation of 15O-labeled molecular oxygen gas (15O2). METHODS AND RESULTS: Twenty-four measurements were performed in eight closed-chest anesthetized greyhounds at baseline and during infusions of adenosine (100 to 200 micrograms.kg-1.min-1), isoproterenol (1 to 10 microgram/min), and propranolol (5 mg botus +0.2 to 1 mg/min) with morphine (5 mg slow infusion +0.2 to 0.5 mg/ min) to obtain a wide range of oxidative metabolism. The PET imaging protocol consisted of 15O2 emission (OEF and MMRO2), transmission, [15O]CO emission (blood pool), and [15O]CO2 emission (myocardial blood flow: MBF(pets) mL.min-1.g-1) scans. OEF was calculated from the PET data (OEFpet) by three different analytical techniques: steady-state, 5-minute, and 8-minute autoradiographic analyses. Reference measurements of MBF (MBFref) and OEF (OEFref) were obtained during 15O2 inhalation with radiolabeled microspheres and paired arterial and coronary sinus blood sampling, respectively. MMRO2 was calculated from the PET (MMRO2pet) and the reference (MMRO2ref) data as follows: MMRO2 = OEF x MBF x (O2 content of arterial blood). OEF measured by the steady-state PET method was well correlated with the reference data over the range 0.16 to 0.73 (OEFpet = 1.03 OEFref -0.01, r = .97), as was MMRO2 over the range 2.4 to 27.5 mL.min-1 x 100 g-1 (MMRO2pet = 0.98 MMRO2ref +0.91, r = .94). OEFpet calculated by use of the 5-minute and 8-minute autoradiographic analyses were equally well correlated with the reference measurements (r = .95 and r = .97, respectively). There were no significant differences between values of MMRO2pet calculated by use of the steady-state, 5-minute, and 8-minute autoradiographic analyses (P = NS by ANOVA). Regional values of MBFpet, OEFpet, and MMRO2pet were homogeneously distributed and similar to the whole-heart values both at baseline and during the various pharmacological interventions. CONCLUSIONS: Accurate quantification of OEF and MMRO2 is feasible with 15O2 inhalation and PET imaging using both the steady-state and autoradiographic analytical approaches. These studies suggest the applicability of this method for quantitative assessments of regional cardiac oxidative metabolism in clinical studies.

Adenosine↗
PubMed2002

Color velocity imaging quantification in the detection of intracranial collateral flow.

BACKGROUND AND PURPOSE: The development of intracranial collateral circulation is associated with a lower risk of stroke. A noninvasive technique that can reliably detect the presence of intracranial collaterals would be a valuable factor in the assessment of risk in patients with occlusive cerebrovascular disease. METHODS: Color velocity imaging quantification was used to measure the blood flow volume of the common carotid and vertebral arteries in 40 patients with carotid occlusive disease. The blood flow volumes in these arteries were correlated with angiographic evidence of collaterals to establish the best cutoffs for detecting intracranial collateral circulation. RESULTS: A blood flow volume of either > or =370 mL/min in the common carotid artery or > or =120 mL/min in the vertebral artery was indicative of the presence of intracranial collaterals. The sensitivity and specificity for the common carotid artery were 92.3% [95% confidence interval (CI), 62.1 to 99.6] and 92.1% (95% CI, 77.5 to 97.9), respectively. The sensitivity and specificity for the vertebral artery were 75.0% (95% CI, 35.6 to 95.5) and 87.5% (95% CI, 66.5 to 96.7), respectively. CONCLUSIONS: Color velocity imaging quantification offers a noninvasive, accurate method for detecting the presence of intracranial collateral circulation and quantifying its magnitude. This technique would be a useful adjunct in screening or continuous monitoring of patients with severe carotid occlusive disease.

Aged↗
PubMed2005

Volumetric quantification of global and regional left ventricular function from real-time three-dimensional echocardiographic images.

BACKGROUND: Real-time 3D echocardiographic (RT3DE) data sets contain dynamic volumetric information on cardiac function. However, quantification of left ventricular (LV) function from 3D echocardiographic data is performed on cut-planes extracted from the 3D data sets and thus does not fully exploit the volumetric information. Accordingly, we developed a volumetric analysis technique aimed at quantification of global and regional LV function. METHODS AND RESULTS: RT3DE images obtained in 30 patients (Philips 7500) were analyzed by use of custom software based on the level-set approach for semiautomated detection of LV endocardial surface throughout the cardiac cycle, from which global and regional LV volume (LVV)-time and wall motion (WM)-time curves were obtained. The study design included 3 protocols. In protocol 1, time curves obtained in 16 patients were compared point-by-point with MRI data (linear regression and Bland-Altman analyses). Global LVV correlated highly with MRI (r=0.98; y=0.99x+2.3) with minimal bias (1.4 mL) and narrow limits of agreement (+/-20 mL). WM correlated highly only in basal and midventricular segments (r=0.88; y=0.85x+0.7). In protocol 2, we tested the ability of this technique to differentiate populations with known differences in LV function by studying 9 patients with dilated cardiomyopathy and 9 normal subjects. All calculated indices of global and regional systolic and diastolic LV function were significantly different between the groups. In protocol 3, we tested the feasibility of automated detection of regional WM abnormalities in 11 patients. In each segment, abnormality was detected when regional shortening fraction was below a threshold obtained in normal subjects. The automated detection agreed with expert interpretation of 2D WM in 86% of segments. CONCLUSIONS: Volumetric analysis of RT3DE data is clinically feasible and allows fast, semiautomated, dynamic measurement of LVV and automated detection of regional WM abnormalities.

Adult↗
PubMed2001

Quantification of coronary artery lumen volume by digital angiography: in vivo validation.

BACKGROUND: Coronary artery lumen volume may potentially have several advantages over the commonly used variables, such as percent stenosis or minimal lumen diameter, in the assessment of coronary artery disease. The goal of this study is to validate a quantitative assessment of lumen volume using a video densitometry technique. METHODS AND RESULTS: Coronary arteriography was performed in 9 swine (body weight 20 to 55 kg) after power injection of contrast material (2 mL/s for 3 seconds) into the left main coronary artery. Phase-matched subtracted images were used to quantify regional lumen volume by a video densitometry technique. The in vivo volume measurements were validated by a polymer cast of the coronary arterial tree made at physiological pressure. The measured cast volume (V(C)) and video densitometric regional lumen volume (V(VD)) were related by V(VD)=1.06 V(C)-0.01 mL (r=0.99). The root mean square and systematic errors for these measurements were 17% and -3%, respectively. CONCLUSIONS: A video densitometry technique for quantification of coronary lumen volume was validated both in vitro and in vivo in a swine animal model. The present results demonstrated the feasibility and potential utility of the video densitometry technique for accurate measurement of regional lumen volume in vivo. This study contributes to the understanding of the angiographic methods used for the assessment of coronary artery disease and indicates that this technique can potentially be used for quantification of diffuse coronary artery disease during routine coronary arteriography.

Angiography, Digital Subtraction↗
PubMed2000

Quantification of periapical bone destruction in mice by micro-computed tomography.

Bacterial infections of the dental pulp result in tissue destruction and periapical bone resorption. The availability of genetically engineered mouse strains is a major advantage in the use of this model system for studies of periapical pathogenesis. The main limitation of the mouse model is its small size, and the necessity for laborious histologic analyses to quantify periapical bone destruction. In the present study, we evaluated the use of a new technology, high-resolution micro-computed tomography (micro-CT), for the rapid and non-invasive quantification of periapical bone destruction. Periapical lesions were induced in the lower first molars of mice by exposing the pulp to the oral environment. Mandibles were harvested on day 21 after pulp exposure, and were subjected to micro-CT analysis, with 17-microm-thick radiographic sections. Samples were then decalcified, embedded, and sectioned for histology. The cross-sectional area of periapical lesions was determined by image analysis of corresponding micro-CT and histologic sections. The results showed a highly significant correlation between micro-CT and histology (p < 0.0001), with mean differences of 4. 1% (range, 0.9 to 7.2%) between the two methods. The mean error associated with image analysis was 4.9% for images obtained by both micro-CT and histology. The variability of replicate (n = 5) independent micro-CT determinations was 3.4%, less than that associated with the image analysis error. These results demonstrate that micro-CT imaging is a rapid, reproducible, and non-invasive method, that gives results that are closely comparable with those obtained by histology. Micro-CT appears to have utility for the accurate quantification of changes in bone architecture in small biological specimens.

Animals↗
PubMed2001

Color subtractive-computer-assisted image analysis for quantification of cutaneous nerves in a diabetic mouse model.

Immunohistochemistry (IHC) is a valuable tool for labeling structures in tissue samples. Quantification of immunolabeled structures using traditional approaches has proved to be difficult. Manual counts of IHC-stained structures are inherently biased, require multiple observers, and generate qualitative data. Stereological methods provide accurate quantification but are complex and labor-intensive when staining must be compared among large numbers of samples. In an effort to quickly, objectively, and reproducibly quantify cutaneous innervation in a large number of counterstained tissue sections, we developed a color subtractive-computer-assisted image analysis (CS-CAIA) system. To develop and test the CS-CAIA method, tissue sections of diabetic (db/db) mouse skin and their wild-type (db/-) littermates were stained by IHC for the neural marker PGP 9.5. The brown-red PGP 9.5 peroxidase stain was colorimetrically isolated through a scripted process of color background removal. The remaining stain was thresholded and binarized for computer determination of nerve profile counts (number of stained regions), area fraction (total area of nerve profiles per unit area of tissue), and area density (total number of nerve profiles per unit area of tissue). Using CS-CAIA, epidermal nerve profile counts, area fraction, and area density were significantly lower in db/db compared to db/- mice.

Animals↗
PubMed1997

Application of photoshop-based image analysis to quantification of hormone receptor expression in breast cancer.

The benefit of quantifying estrogen receptor (ER) and progesterone receptor (PR) expression in breast cancer is well established. However, in routine breast cancer diagnosis, receptor expression is often quantified in arbitrary scores with high inter- and intraobserver variability. In this study we tested the validity of an image analysis system employing inexpensive, commercially available computer software on a personal computer. In a series of 28 invasive ductal breast cancers, immunohistochemical determinations of ER and PR were performed, along with biochemical analyses on fresh tumor homogenates, by the dextran-coated charcoal technique (DCC) and by enzyme immunoassay (EIA). From each immunohistochemical slide, three representative tumor fields (x20 objective) were captured and digitized with a Macintosh personal computer. Using the tools of Photoshop software, optical density plots of tumor cell nuclei were generated and, after background subtraction, were used as an index of immunostaining intensity. This immunostaining index showed a strong semilogarithmic correlation with biochemical receptor assessments of ER (DCC, r = 0.70, p < 0.001; EIA, r = 0.76, p < 0.001) and even better of PR (DCC, r = 0.86; p < 0.01; EIA, r = 0.80, p < 0.001). A strong linear correlation of ER and PR quantification was also seen between DCC and EIA techniques (ER, r = 0.62, p < 0.001; PR, r = 0.92, p < 0.001). This study demonstrates that a simple, inexpensive, commercially available software program can be accurately applied to the quantification of immunohistochemical hormone receptor studies.

Breast Neoplasms↗
PubMed1999

Quantification of protein A-gold staining for peroxisomal enzymes by confocal laser scanning microscopy.

The protein A-gold technique has been widely applied for visual localization and quantification of various antigens by electron microscopy. Observation of specimens stained by the protein A-gold technique with conventional light microscopy is difficult because of insufficient sensitivity of the staining. Light microscopic visualization and quantification of the reaction products were attempted employing a confocal laser scanning microscope (CLSM). Liver tissues of normal and peroxisome proliferator-treated rats were fixed and embedded in Lowicryl K4M resin. Ultrathin and thin sections were stained for catalase and a peroxisome-specific beta-oxidation enzyme by the protein A-gold technique. Ultrathin sections were observed by electron microscopy and the labeling density for each enzyme was analyzed with an image analyzer. Thin sections were observed with a CLSM in the reflection mode and the intensity of the light reflection was analyzed under the same conditions for all specimens. A comparison of these two observation procedures was also attempted using liver tissues stained with various concentrations of the antibody for catalase. The intensity of the reflection for each, as observed by CLSM, correlated well with the labeling density observed by electron microscopy. CLSM made it possible to quantify and to directly observe protein A-gold staining at the light microscopic level.(J Histochem Cytochem 47:1343-1349, 1999)

Animals↗
PubMedDate not supplied

Quantification of protein metabolism in vivo for skin, wound, and muscle in severe burn patients.

BACKGROUND: In response to injury, muscle catabolism can be extensive, and in theory, the wound consumes amino acids to support healing. The purpose of this study is to assess a technique by which in vivo protein kinetics of muscle, wound, and normal skin can be quantified in burn-injured patients. METHODS: Study protocol consisting of infusion of d5 phenylalanine; biopsies of skeletal muscle, skin, and donor-site wound on the leg; quantification of blood flow to total leg, wound, and skin; and sequential blood sampling from the femoral artery and vein. Five-compartment modeling was used to quantify the rates of protein synthesis, breakdown, and phenylalanine transport between muscle, wound, and skin. RESULTS: The study results demonstrated a net release of phenylalanine from muscle yet a net consumption of phenylalanine by the wound. Compared with skin, the wound had a substantially increased rate of protein synthesis and a reduced rate of protein breakdown (p < .01). Transport rates into and out of muscle were significantly higher than those for wound (p < .01). CONCLUSIONS: This novel methodology enables in vivo quantification of the integrated response of muscle, wound, and skin protein/amino acid metabolism and confirms the long-held theory of a net catabolism of muscle and a net anabolism of wound protein in patients after injury. This methodology can be used to assess the metabolic impact of such measures as nutrition, pharmacologic agents, and surgical procedures.

Adult↗
PubMedDate not supplied

A novel image probing system for precise quantification of angiogenesis.

The rapid development of clinical diagnostic imaging technology, in tandem with medical and angiogenesis research, has led to some major advances in healthcare. The chorioallantoic membrane assay is commonly used for studying normal angiogenesis as well as putative angiogenic and antiangiogenic substances. Despite the progress, it is generally recognized that a major problem is the lack of a suitable quantitative bioassay for angiogenesis. Image probing is a novel solution to this problem, which, together with its associated discipline of evaluating angiogenesis, is showing great potential not only for accurate measurement of even very small blood vessels but also for detailed three-dimensional quantification of blood vessels and surface characterization. This technique could be a helpful tool for quantification in angiogenesis research.

Animals↗
PubMed2004

Real-time PCR quantification of c-erbB-2 gene is an alternative for FISH in the clinical management of breast carcinoma patients.

Evaluation of gene amplification and protein expression of the c-erbB-2/neu in breast carcinomas has been an important task in breast cancer management. Although immunohistochemistry is widely applied, fluorescence in situ hybridization (FISH) technology shows its advantage in discriminating tumors in an objective manner. More recently, development of LightCycler technology permits evaluation of gene amplification with a small volume of DNA run in a 20 microL glass capillary. In this study, a series of 87 breast carcinomas were chosen for evaluation of c-erbB-2/neu gene amplification detected by both LightCycler technology and FISH. Real-time polymerase chain reaction (PCR) was performed in LightCycler capillaries with 10 ng sample DNA. By using LightCycler Relative Quantification Software version 1 (LightCycler, Roche, Mannheim, Germany), the amount of c-erbB-2 DNA was calculated as a ratio of c-erbB-2/reference gene quantity in a sample, and then the ratio was divided by the ratio of c-erbB-2 gene/reference gene quantities of a calibrator DNA (a standard DNA provided in the kit), which was run with each sample reaction in parallel. Dual-color FISH was performed on sections of the formalin-fixed, paraffin-embedded tissue array samples using the DAKO HER2 FISH pharmDX kit (DAKO A/S, Glostrup, Danmark) according to the manufacturer's instructions. Furthermore, immunohistochemistry was performed in parallel, with both the NCL-CB11 and HercepTest antibodies. Both the FISH technology and the LightCycler-PCR identified a similar percentage of tumors with c-erbB-2 gene amplification in our present study, 16% (14/87) and 15% (13/87), respectively, whereas immunohistochemistry demonstrated 32% and 34% c-erbB-2 overexpression with the NCL-CB11 and HercepTest antibodies, respectively. In addition, FISH and PCR were highly correlated in detecting tumors mainly with 3+++ c-erbB-2 protein expression by immunohistochemistry, indicating that LightCycler real-time quantification of c-erbB-2 gene may be an alternative to FISH in breast cancer clinical application.

Biomarkers, Tumor↗
PubMed2006

Quantification in echocardiography.

Until recently, more than 2200 Swan Ganz catheters were used annually in the operating rooms (OR) and intensive care unit (ICU) of the Catharina Hospital in Eindhoven, The Netherlands. After cardiologists who were specialists in echocardiography (ECHO) trained anesthesiologists in ECHO, the need for these catheters in cardiac and noncardiac surgery was reduced. Initially intended as a local teaching project, an ECHO teaching compact disk (CD) was produced during the training and distributed later worldwide, thanks to a positive review in a major anesthesiology publication. By reducing the number of Swan Ganz catheters, the hospital could finance and acquire two echocardiography machines for the OR and ICU. The availability of these machines resulted in a further reduction of the number of Swan Ganz catheters. However, the need for quantification (eg, measurements of cardiac output) remained. During the creation of the ECHO teaching CD, the idea was born to apply indicator-dilution principles on injected echo contrast. This study was performed in cooperation with the Signal Processing Department of the Eindhoven University of Technology. Advanced signal processing and modelling were used to develop algorithms to enable quantification of intrapulmonary blood volume, ejection-fraction, and flow from the transesophageal echocardiography approach. These quantitative measurements, which can be performed on an outpatient basis, may become a real asset in cardiology, anesthesiology, and intensive care.

Algorithms↗
PubMed1990

Computerized quantification of immunofluorescence-labeled axon terminals and analysis of co-localization of neurochemicals in axon terminals with a confocal scanning laser microscope.

The confocal scanning laser microscope (CSLM) offers improved optical resolution and contrast, high photometric precision, and the ability to make optical sections. These benefits were explored for use in quantitative analysis of immunofluorescence-labeled axon terminals. Guidelines were obtained for adjustments of the CSLM parameters. In the present applications, bleaching of the fluorescence did not represent a serious obstacle to analysis with the CSLM. A method was developed to distinguish the background fluorescence from the specific fluorescence labeling. This procedure made way for the development of automated quantification of immunolabeled axon terminals. The automated procedures substantially reduced the man-hour expenditure for analysis and provided highly reproducible quantifications compared with manual methods. The increased resolution and contrast of the CSLM allowed measurements of the fluorescence signal strength of individual axon terminals. The CSLM also allowed detection of co-localized neurochemicals in axon terminals.

Animals↗
PubMed2004

Quantification of Plasmodium malariae infection in mosquito vectors.

Plasmodium malariae occurs in various tropical regions throughout the world and causes low, yet significant, levels of morbidity in human populations. One means of studying the ecology and frequency of this parasite is by measuring sporozoite loads in the salivary glands of infected mosquitoes. An effective, species-specific test that can be used to detect the presence of sporozoites in mosquitoes is the circumsporozoite ELISA. The aim of the present study was to standardize the circumsporozoite ELISA for P.malariae, by setting quantification parameters using, as antigen, either a synthetic peptide or extracts of whole sporozoites. The standard quantification curves produced indicated that the assay had a lower threshold of sensitivity of 250 sporozoites in a 50-microl sample, equivalent to about 1250 sporozoites in a mosquito.

Animals↗
PubMed2005

An algorithm for the determination and quantification of components of nucleic acid mixtures based on single sequencing reactions.

BACKGROUND: Determination and quantification of nucleic acid components in a mixture is usually accomplished by microarray approaches, where the mixtures are hybridized against specific probes. As an alternative, we propose here that a single sequencing reaction from a mixture of nucleic acids holds enough information to potentially distinguish the different components, provided it is known which components can occur in the mixture. RESULTS: We describe an algorithm that is based on a set of linear equations which can be solved when the sequencing profiles of the individual components are known and when the number of sequenced nucleotides is larger than the number of components in the mixture. We have implemented the procedure for one type of sequencing approach, pyrosequencing, which produces a stepwise output of peaks that is particularly suitable for the procedure. As an example we use signature sequences from ribosomal RNA to distinguish and quantify several different species in a mixture. Using simulations, we show that the procedure may also be applicable for dideoxy sequencing on capillary sequencers, requiring only some instrument specific adaptations of protocols and software. CONCLUSION: The parallel sequencing approach described here may become a simple and cheap alternative to microarray experiments which aim at routine re-determination and quantification of known nucleic acid components from environmental samples or tissue samples.

Algorithms↗
PubMed2006

Highly sensitive real-time PCR for specific detection and quantification of Coxiella burnetii.

BACKGROUND: Coxiella burnetii, the bacterium causing Q fever, is an obligate intracellular biosafety level 3 agent. Detection and quantification of these bacteria with conventional methods is time consuming and dangerous. During the last years, several PCR based diagnostic assays were developed to detect C. burnetii DNA in cell cultures and clinical samples. We developed and evaluated TaqMan-based real-time PCR assays that targeted the singular icd (isocitrate dehydrogenase) gene and the transposase of the IS1111a element present in multiple copies in the C. burnetii genome. RESULTS: To evaluate the precision of the icd and IS1111 real-time PCR assays, we performed different PCR runs with independent DNA dilutions of the C. burnetii Nine Mile RSA493 strain. The results showed very low variability, indicating efficient reproducibility of both assays. Using probit analysis, we determined that the minimal number of genome equivalents per reaction that could be detected with a 95% probability was 10 for the icd marker and 6.5 for the IS marker. Plasmid standards with cloned icd and IS1111 fragments were used to establish standard curves which were linear over a range from 10 to 10(7) starting plasmid copy numbers. We were able to quantify cell numbers of a diluted, heat-inactivated Coxiella isolate with a detection limit of 17 C. burnetii particles per reaction. Real-time PCR targeting both markers was performed with DNA of 75 different C. burnetii isolates originating from all over the world. Using this approach, the number of IS1111 elements in the genome of the Nine Mile strain was determined to be 23, close to 20, the number revealed by genome sequencing. In other isolates, the number of IS1111 elements varied widely (between seven and 110) and seemed to be very high in some isolates. CONCLUSION: We validated TaqMan-based real-time PCR assays targeting the icd and IS1111 markers of C. burnetii. The assays were shown to be specific, highly sensitive and efficiently reproducible. Cell numbers in dilutions of a C. burnetii isolate were reliably quantified. PCR quantification suggested a high variability of the number of IS1111 elements in different C. burnetii isolates, which may be useful for further phylogenetic studies.

Coxiella burnetii↗
PubMed2006

Semi-automated segmentation and quantification of adipose tissue in calf and thigh by MRI: a preliminary study in patients with monogenic metabolic syndrome.

BACKGROUND: With the growing prevalence of obesity and metabolic syndrome, reliable quantitative imaging methods for adipose tissue are required. Monogenic forms of the metabolic syndrome include Dunnigan-variety familial partial lipodystrophy subtypes 2 and 3 (FPLD2 and FPLD3), which are characterized by the loss of subcutaneous fat in the extremities. Through magnetic resonance imaging (MRI) of FPLD patients, we have developed a method of quantifying the core FPLD anthropometric phenotype, namely adipose tissue in the mid-calf and mid-thigh regions. METHODS: Four female subjects, including an FPLD2 subject (LMNA R482Q), an FPLD3 subject (PPARG F388L), and two control subjects were selected for MRI and analysis. MRI scans of subjects were performed on a 1.5T GE MR Medical system, with 17 transaxial slices comprising a 51 mm section obtained in both the mid-calf and mid-thigh regions. Using ImageJ 1.34 n software, analysis of raw MR images involved the creation of a connectedness map of the subcutaneous adipose tissue contours within the lower limb segment from a user-defined seed point. Quantification of the adipose tissue was then obtained after thresholding the connected map and counting the voxels (volumetric pixels) present within the specified region. RESULTS: MR images revealed significant differences in the amounts of subcutaneous adipose tissue in lower limb segments of FPLD3 and FPLD2 subjects: respectively, mid-calf, 15.5% and 0%, and mid-thigh, 25.0% and 13.3%. In comparison, old and young healthy controls had values, respectively, of mid-calf, 32.5% and 26.2%, and mid-thigh, 52.2% and 36.1%. The FPLD2 patient had significantly reduced subcutaneous adipose tissue compared to FPLD3 patient. CONCLUSION: Thus, semi-automated quantification of adipose tissue of the lower extremity can detect differences between individuals of various lipodystrophy genotypes and represents a potentially useful tool for extended quantitative phenotypic analysis of other genetic metabolic disorders.

Journal Article↗
PubMed2005

Application of protein lysate microarrays to molecular marker verification and quantification.

This study presents the development and application of protein lysate microarray (LMA) technology for verification of presence and quantification of human tissue samples for protein biomarkers. Sub-picogram range sensitivity has been achieved on LMA using a non-enzymatic protein detection methodology. Results from a set of quality control experiments are presented and demonstrate the high sensitivity and reproducibility of the LMA methodology. The optimized LMA methodology has been applied for verification of the presence and quantification of disease markers for atherosclerosis. LMA were used to measure lipoprotein [a] and apolipoprotein B100 in 52 carotid endarterectomy samples. The data generated by LMA were validated by ELISA using the same protein lysates. The correlations of protein amounts estimated by LMA and ELISA were highly significant, with r2 > or = 0.98 (p < or = 0.001) for lipoprotein [a] and with r2 > or = 0.94 (p < or = 0.001) for apolipoprotein B100. This is the first report to compare data generated using proteins microarrays with ELISA, a standard technology for the verification of the presence of protein biomarkers. The sensitivity, reproducibility, and high-throughput quality of LMA technology make it a potentially powerful technology for profiling disease specific protein markers in clinical samples.

Journal Article↗