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The use of multiple doses and pharmacodynamic system analysis to distinguish between dispositional delays and time-variant pharmacodynamics.

Pharmacokinetic-pharmacodynamic modeling algorithms, in general, rely on hysteresis minimization techniques that assume time-invariant pharmacodynamics (constant biophase concentration-effect relationships). When time-variant pharmacodynamics are observed, a specific model for tolerance or sensitization is required. However, with single dosing, hysteresis that results from a time-variant biophase concentration-effect relationship cannot be distinguished from hysteresis caused by dispositional delays. This can lead to the inappropriate minimization of hysteresis. As an approach to this problem, simulated and real kinetic-dynamic data were analyzed with the pharmacodynamic system analysis program ATTRACT. The use of a multiple dosing regimen and this hysteresis minimization algorithm resulted in a simple diagnostic test to distinguish between dispositional effects of acute tolerance and sensitization.

Dose-Response Relationship, Drug↗

Development of a topographic analysis system for manometric studies in the gastrointestinal tract.

BACKGROUND: Intraluminal pressures from the gastrointestinal tract are conventionally analyzed from a set of two-dimensional tracings. We hypothesized that more information could be extracted by considering spatial relationships of pressure data. METHODS: A system was developed for recording pressure from up to 21 sites and analyzing the results using two- and three-dimensional plotting methods connecting data in space as well as time. Esophageal pressures were measured in 10 volunteers. Data were displayed as three-dimensional contour plots, surface plots, or animated transformations of the pressure wave as it traveled axially in the direction of bolus movement. RESULTS: Subjects tolerated catheter placement, and all analysis methods (conventional and topographic) were successfully completed in each case. At least 80% of the esophageal body and one sphincter could be sampled with the catheter in either a proximal or distal recording position. CONCLUSIONS: A topographic analysis system is available for studying time and space relationships of pressure data. These novel techniques have the potential to provide greater insight into normal and abnormal gastrointestinal motor function than conventional manometric methods.

Adult↗

Automated image analysis system for detecting boundaries of live prostate cancer cells.

Image analysis provides a powerful tool for quantifying cell motility and has been used to correlate motility with metastatic potential in an animal model of prostate cancer. However, widespread use of this image analysis method has been limited because earlier methods of quantitative analysis required time-intensive and subjective manual tracing of cell contours. In this report, we describe a fully automated image segmentation algorithm for detection and morphometric description of prostatic cells. The segmentation system was tested on prostate cell images generated from Hoffman modulation contrast microscopy (47 cells at 64 time points = 3,008 images) and differential interference contrast microscopy (29 cells at 64 times points plus 1 cell at 62 time points = 1,918 images). Morphometric measurements were derived from computer-determined cell boundaries and compared with the same measurements derived from manually traced cell boundaries. Final correlation coefficients for area and perimeter measurements for Hoffman and differential interference contrast microscopy were (0.76, 0.62) and (0.93, 0.93), respectively. Results with our differential interference contrast images demonstrate that our segmentation algorithm reliably and efficiently replaces the need for manually traced cell boundaries in addition to eliminating intraobserver variation. Our automated segmentation process will have immediate utility in our motility analysis system that relates cell motility with metastatic potential of prostate cancer.

Adenocarcinoma↗

A systems analysis of a failure to test the effectiveness of waiting-list group therapy.

This nonexperimental effectiveness study attempted to evaluate the utility of a brief waiting-list group. The setting was a university clinic providing treatment for an inner-city population. Health delivery and staff dynamics made it difficult to conduct clinical research in this treatment-oriented setting. The nonrandom design allowed for patient choice, with few clients attending more than two group sessions, thus decreasing its impact. Managed-care pressures decreased staff cooperation with our research objectives, resulting in very low return rates in testing and follow-up data. A social systems analysis, highlighting staff and institutional ambivalence, is used to understand the failure to adequately test the effectiveness of waiting-list group therapy. Recommendations are offered to investigators who contemplate conducting clinical research with limited resources.

Health Maintenance Organizations↗

Comparison of cyclin A and MIB-1 expression in astrocytic tumors using image-based cell analysis system.

Traditional prognostic indicators for astrocytic tumors include tumor size, type, and histologic grade. Data suggest that tumor growth fraction assessed by MIB-1 is an important predicator of survival. Cyclin A, like MIB-1, is a recently described specific marker of proliferation, detectable primarily in S phase of the cell cycle as it undergoes progression to G2 phase. Thirty-seven cases of astrocytic tumors--14 cases of World Health Organization grade 1 and 2 (low grade tumors), 8 cases of grade 3 (anaplastic astrocytoma), and 15 cases of grade 4 (glioblastoma multiforme)--were simultaneously evaluated using routine paraffin immunohistochemical methods with commercial antibodies against MIB-1 and cyclin A. The results were quantitated using a Cell Analysis System (CAS) 200 image analyzer. The mean percentage positive nuclear area for MIB-1 was 3.32% in grade 1 and 2, 19.27% in grade 3, and 24.00% in grade 4 astrocytic tumors. Cyclin A showed a similar pattern of positivity in the same cases: 2.84% in grade 1 and 2, 16.27% in grade 3, and 24.88% in grade 4 astrocytic tumors. The data suggest that both proliferation markers correlated significantly with histologic grade. Cyclin A appears to be as good an indicator of brain tumor proliferation as MIB-1. Because cyclin A is detectable primarily in the S phase of the cell cycle, the fraction of cells positive for cyclin A should allow for a more accurate indicator of tumor progression.

Antigens, Nuclear↗

Cognitive-behavioral analysis system of psychotherapy: an interactional treatment approach for dysthymic disorder.

Dysthymic disorder, a troublesome problem for many young adults, can be effectively treated by focusing the client's attention on the interactional problems the person reports to the therapist. In therapy, interactional issues frequently take a backseat to the more obvious intrapersonal symptoms that many contemporary theories of depression emphasize. James Coyne (1976, 1982) has recently pointed out this oversight to workers in the field. The first part of the paper will discuss several aspects of current treatment approaches that deal with depression from an intrapersonal perspective. I will argue that a more realistic approach to treatment must involve accentuating the interactional predicament of the dysthymic. The Cognitive-Behavioral Analysis System, which will be introduced in the second part of the paper, approaches both the intrapersonal and interpersonal problems of the dysthymic from an interactional perspective. Four successful direct replication cases will be described, illustrating the efficacy of such an approach.

Adult↗

Locating the centric relation prematurity with a computerized occlusal analysis system.

Locating the first tooth contact that interferes with freedom of movement in and out of centric relation has been the diagnostic and treatment objective of most occlusal therapies. The centric relation prematurity can be located by various methods, which involve operator-guided mandibular positioning combined with the patient's subjective assessment of his or her perceived first tooth contact. The method known as bimanual manipulation has been widely recognized and accepted as a predictable method of determining and verifying the centric relation position. The first occlusal contact that results when the mandible is closed on a correct centric relation axis is known as the centric relation prematurity. An alternative procedure combines bimanual manipulation with the simultaneous recording of the sequence of resultant tooth contacts using a computerized occlusal analysis system. This alternative offers a significant improvement in the precision of locating the first tooth contact. This article describes a method of identifying the first tooth contact while not relying on the patient's subjective assessment of his or her perceived occlusal feel.

Adult↗

Quantitative nuclear morphometry, Markovian texture descriptors, and DNA content captured on a CAS-200 Image analysis system, combined with PCNA and HER-2/neu immunohistochemistry for prediction of prostate cancer progression.

One hundred and twenty-four localized prostate cancer patients operated on at Johns Hopkins Hospital (JHH) since 1975 were identified. The sample was optimized for evaluation of prostate cancer progression. Based upon accurate clinical histories, these radical prostatectomy patients included 50 progressors and 74 non-progressors using appearance of serum PSA as an indication of recurrence (mean follow-up = 8.6 +/- 1.8 years, range 7-15 years). All patients included in the study had no involvement of their seminal vesicles or lymph nodes at the time of prostatectomy. Average time to progression was 3.6 +/- 2 years, range of 1-8 years. Using paraffin-embedded specimens, several five micron sections were cut and placed on Probe-On slides; one slide was H&E-stained and the other was Feulgen-stained. The H&E and Feulgen-stained slides were screened and "dotted" by pathologists at JHH and CytoDynostics, Inc. A CAS-200 Image analysis system (Cell Image Systems, Elmhurst, IL) equipped with a Cell Measurement Program version 1.2 beta, was used to capture the Feulgen-stained images and to perform the calculations. From the "dotted" areas, 150 cancer cells were selected for measurement of DNA content and 27 nuclear morphometric shape and size factors, including 21 Markovian chromatin texture variables. Additional sections were used for immunochemistry staining with an alkaline phosphatase streptavidin-biotin complex stain to detect and quantitate cancer cells binding monoclonal antibodies directed against proliferating cell nuclear antigen (PCNA) and HER-2/neu antigen. All data were entered into a statistical program (STATA) for further analysis and univariate and multivariate statistical analysis was performed using logistic regression and its stepwise variant. The biomarkers of greatest utility to detect progressors when analyzed univariately included post-operative Gleason score (p = < 0.0001), HER-2/neu antigenicity (p = 0.0147), CAS-200 DNA ploidy (p = 0.008), and twelve Markovian nuclear texture and shape features (p = < 0.0001), whereas PCNA (p = 0.160) failed. The optimal set of nuclear morphometry progression tumor features were selected using backward stepwise logistic regression estimate analysis which drops variables due to collinearity. Although post-operative Gleason score is a strong univariate predictor of progression, DNA ploidy and HER-2/neu contributed significantly to further stratification of higher risk groups within the low Gleason score subpopulation. The best Markovian features combined with post-operative Gleason score generated sensitivity = 90%, specificity = 96%, positive predictive value = 94%, negative predictive value = 93% and the area under the receiver operator curve was 0.975.

Biomarkers, Tumor↗

[Total hematological analysis system as a screening test for hematological malignancy].

Measurement of complete blood cell count and white blood cell differentiation is an essential laboratory test and the most important screening test for hematological malignancy. Recently, several automated blood cell analyzers have been developed to improve accuracy and precision. When flag messages generated in the presence of morphological abnormalities of the samples are displayed, manual revision is necessary. In our laboratory, the manual revision rate has been 35-40%. Therefore blood cell analyzers are useful in screening for abnormalities as well as greatly reducing expensive and time-consuming manual differential procedures. In addition, automated blood cell analyzers can provide several types of useful information including the leukocyte distribution scattergram. However, most such information is not utilized in the clinical field. In the future, a total hematological analysis system will be constructed so that all information provided by automated blood cell analyzer and by manual methods are available.

Blood Cell Count↗

Miniature liquid flow sensor and feedback control of electroosmotic and pneumatic flows for a micro gas analysis system.

Accurate liquid flow control is important in most chemical analyses. In this work, the measurement of liquid flow in microliters per minute was performed, and feedback control of the flow rate was examined. The flow sensor was arranged on a channel made in a polydimethylsiloxane (PDMS) block. The center of the channel was cooled by a miniature Peltier device, and the change in temperature balance along the channel formed by the flow was measured by two temperature sensors. Using this flow sensor, feedback flow control was examined with two pumping methods. One was the electroosmotic flow method, made by applying a high voltage (HV) between the reagent and waste reservoirs; the other was the piezo valve method, in which a micro-valve-seat was fabricated in a PDMS cavity with a silicone diaphragm. The latter was adopted for a micro gas analysis system (microGAS) for measuring atmospheric H2S and SO2. The obtained baselines were stable, and better limits of detection were obtained.

Air Pollutants↗

Computer analysis system of blood oxygen saturation in an animal hypoxia model.

An experimental animal hypoxia model has been developed. It consists of two sensors (an in vitro and in vivo model), an experimental device and a computer signal processing system. This method can easily be applied to determine and analyse blood oxygen saturation at various hypoxia levels. It can also be used to evaluate the accuracy of pulse oximetry over a wide range of oxyhemoglobin desaturation levels. The DC and AC components of recorded red and infra-red signals, the dual-wavelength ratio R12 and the reading of a pulse oximeter (SpO2) can be automatically calculated and displayed on a computer screen. Preliminary results of the animal hypoxia test indicate that the measurements made by the instrument correlate well with the oxygen saturation readings of the automatic blood gas analyser AVL945. The computer analysis system is suitable for repeated estimations in the animal model.

Animals↗

Measurement of blood flow velocity in feeder vessels of choroidal neovascularization by a scanning laser ophthalmoscope and image analysis system.

PURPOSE: To measure the blood flow velocities in feeder vessels of patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration. METHODS: We examined the early images of indocyanine green videoangiography (v-ICGA) in 29 patients (29 eyes) with CNV, in whom feeder vessels could be identified by v-ICGA. The v-ICGA images were installed in a personal computer. With original software, optical density measurements were performed for the determination of dye-dilution curves. The flow velocity in a CNV feeder vessel was obtained by analyzing the dye-dilution curves. RESULTS: The mean flow velocity in feeder vessels was 33.8 +/- 32.5 mm/s. The flow velocity in feeder vessels of CNV with a diameter of 1.5 mm or larger was significantly higher than that in feeder vessels of CNV with a diameter smaller than 1.5 mm (P <.05, unpaired t-test). CONCLUSIONS: The flow velocity in CNV feeder vessels can be measured with v-ICGA and a computer-based image analysis system. This system would be useful in the evaluation of choroidal circulation.

Aged↗

A novel approach to the quantification of hepatic stellate cells in intravital fluorescence microscopy of the liver using a computerized image analysis system.

Hepatic stellate cells (HSC) are nonparenchymal liver cells which reside in the space of Disse within the hepatic microcirculatory unit. HSC can be distinguished using intravital fluorescent microscopy (IVFM) due to the autofluorescence from their intracellular vitamin A. Herein we report on a novel approach for the quantification of video-recorded rat HSC images acquired by IVFM (excitation 360 nm/emission 420 nm) by the combined use of the "Cell counting macro" and the "Measurement macros" in the NIH image software. The approach involved two major steps using (i) the "Cell counting macro" for automatic detection, threshold-setting, and generation of a binary image of the vitamin A autofluorescence in the HSC images and (ii) the "Compute percent black and white" command in the "Measurement macros" to automatically determine the HSC density (%), which was then expressed as percentage of the total area of vitamin A autofluorescence-associated sites per observation area. Comparing the vitamin A autofluorescence areas in the original and the binary fashion HSC images revealed that the "Cell counting macro" was an optimal option for the analysis of the low-magnification (x10 objective) HSC images, whereas this macro was not suitable for the analysis of the higher magnification (40x objective) HSC images unless modifications were made. Our analysis revealed that HSC represent approximately 4-5% of the total area of the liver surface. In analyzing the higher magnification HSC microfluorographs, the use of the original "Cell counting macro" resulted in a significant underestimation of HSC density (60% reduction, P < 0.01) when compared with those analyzed using our modified macro. This study represents the first report of an automatic and reliable approach to the intravital fluorescent microscopic quantification of HSC using a computer-NIH image analysis system.

Animals↗

Disease system analysis: basic disease progression models in degenerative disease.

PURPOSE: To describe the disease status of degenerative diseases (i.e., type 2 diabetes mellitus, Parkinson's disease) as function of disease process and treatment effects, a family of disease progression models is introduced. METHODS: Disease progression is described using a progression rate (Rdp) acting on the synthesis or elimination parameters of the indirect response model. Symptomatic effects act as disease-dependent or -independent effects on the synthesis or elimination parameters. Protective drug effects act as disease dependent or -independent effects on Rdp. RESULTS: Simulations with the ten disease models show distinctly different signature profiles of treatment effects on disease status. Symptomatic effects result in improvement of disease status with a subsequent deterioration. Treatment cessation results in a disease status equal to the situation where treatment had not been applied. Protective effects result in a lasting reduction, or even reversal, of the disease progression rate and the resulting disease status during the treatment period. After cessation of treatment the natural disease course will continue from the disease status at that point. CONCLUSION: Disease system analysis constitutes a scientific basis for the distinction between symptomatic versus protective drug effects in relation to specific disease processes as well as the identification of the exposure-response relationship during the time-course of disease.

Biomarkers↗

Evaluation of a personal computer-based quantitative coronary analysis system for rapid assessment of coronary stenoses.

Quantitative coronary analysis (QCA) is a technique that is rarely used because of the complexity and expense of existing systems. We studied a new personal computer-based QCA system that is capable of both geometric and densitometric analysis and compared it to a previously validated QCA system. Both systems performed extremely well in phantom analysis with 11 phantoms filmed in both 5-inch and 7-inch magnifications (R greater than 0.97 and SEE less than 0.33 mm for all modes). In 28 abnormal coronary angiograms analyzed at end diastole, stenosis and reference diameter correlations between the two systems were excellent (R = 0.90 and 0.96 and SEE = 0.43 and 0.33 mm for densitometric and geometric modes, respectively). Intraobserver and interobserver correlation was also excellent for both analysis modes. The new QCA system was able to perform analysis in approximately one third the time required by previously validated system and was much less expensive. We conclude that personal computer-based coronary analysis is an accurate, quick, and relatively inexpensive means for performing QCA that may help to make this technique feasible for nonresearch settings.

Constriction, Pathologic↗

An optically scanned EMS reporting form and analysis system for statewide use: development and five years' experience.

Analysis of emergency medical services (EMS) systems data is crucial to planning, education, research, and quality assurance programs. Currently, comparative analysis of EMS data between regions or states is virtually impossible due to wide variations in data collection and analysis methods. To devise a practical and uniform EMS reporting system, we referenced the minimum data set (MDS) established by the federal government in 1974 and surveyed 22 states known to be using uniform reporting systems. In developing our final data set, elements were added based on inclusion in the MDS, national survey results, a review of current EMS literature, and consensus of local EMS providers. This set of 48 elements then was incorporated into a reporting form using narrative and optically scanned formats, allowing automated data collection for computer analysis. After a pilot study, the system was improved to allow high-speed ink reading and large volume data storage and analysis using a microcomputer. This system has subsequently been adopted by seven states. The combined data base exceeds 250,000 cases. Error screening algorithms ensure data integrity and are also used for quality assurance. Customized output reports can be generated within minutes and have assisted in EMS quality assurance, planning, and research. We believe that the successful performance of this system supports the use of the suggested data elements as well as optical scanning and microcomputer analysis of EMS data.

Data Collection↗

[Measurement of flow velocity in feeder vessels of choroidal neovascularization with a scanning laser ophthalmoscope and image analysis system].

PURPOSE: To measure flow velocities in feeder vessels of choroidal neovascularization(CNV) secondary to age-related macular degeneration(AMD). METHODS: We examined early images of indocyanine green(ICG) angiography in 29 eyes with CNV secondary to AMD, in which feeder vessels could be identified. ICG videoangiographic images recorded at 30 frames per second with a scanning laser ophthalmoscope were installed in a personal computer. With original software, optical density measurements made with an image analyzer were performed on ICG videoangiograms for determination of dye-dilution curves. The time(T50) from the beginning of a dye-dilution curve to the ascending parts of the curve at 50% of the peak intensity was calculated. Flow velocity in a feeder vessel was obtained by dividing the distance between two points by the circulation time between T50 s at the two points on the feeder vessel. RESULTS: The mean flow velocity in feeder vessels was 33.8 +/- 32.5 (mean +/- standard deviation) mm/sec. The mean velocity in the feeder vessels of large CNV with greatest linear diameter of 1 disc diameter(DD) or larger was 43.4 +/- 30.6 mm/sec; the mean velocity in the feeder vessels of small CNV with greatest linear diameter smaller than 1DD was 20.3 +/- 20.2 mm/sec. There was a significant difference between them. CONCLUSION: The flow velocity in feeder vessels of CNV could be measured with ICG angiography and a computer-based image analysis system. This system would be useful in evaluation of choroidal circulation.

Aged↗

[Study of vocal function following partial laryngectomy with computer analysis system].

Vocal function of 28 patients following partial laryngectomy was studied with HGF-1 personal computer system. The system consists of spectrogram analysis of correlogram and sonogram. The result showed that different phonetic positions have different vocal functions. Vocal function of the patients who had new vocal cord and patients who received supraglottic hemilaryngectomy is nearly normal. Whereas vocal function of patients with supraglottic construction and speaking shunt is very poor. This system appears to be an objective and quantitative tool for vocal function study.

Aged↗