A detailed morphometric study of normal human blood platelets is described. The purpose has been to evaluate the morphological characteristics of platelets exposed to minimal handling procedures in order to obtain an ...
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A detailed morphometric study of normal human blood platelets is described. The purpose has been to evaluate the morphological characteristics of platelets exposed to minimal handling procedures in order to obtain an optimal basis for the appraisal of platelets in disease. Blood from 10 healthy volunteers was collected directly into buffered glutaraldehyde and processed for electron microscopy. This platelet fixation procedure resulted in excellent preservation of resting platelet ultrastructure with one exception: the dense bodies. Compared to platelets fixed following washing procedures, our directly fixed platelets comprised fewer pseudopods and contained more glycogen. An unexpected feature of the open canalicular system was the apparent release of blisters interpreted as microvesicles. Employing a computerized image analyzer, 300 of the platelets were examined morphologically. The morphometric data thus obtained were analyzed statistically, resulting in a set of standard values for morphological characteristics of human platelets which we have found useful in subsequent evaluations of platelet morphology in disease. Significant inter-individual variance was, however, detected in two instances, in the section area of the alpha granules, as well as the area fraction of platelet sections occupied by channels of the open canalicular system (OCS). This should be taken into consideration when appraising platelet ultrastructure in health and disease.
We have developed, validated, and employed a technique of retrospective spatial alignment and integrated display of positron emission tomographic (PET) and high-resolution magnetic resonance (MR) brain images. The met...
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We have developed, validated, and employed a technique of retrospective spatial alignment and integrated display of positron emission tomographic (PET) and high-resolution magnetic resonance (MR) brain images. The method was designed to improve the anatomical evaluation of functional images obtained from single subjects. In the first computational step, alignment of PET and MR data sets is achieved by iteratively matching in three orthogonal views the outermost scalp contours derived from front-to-back projections of each data set. This procedure avoids true three-dimensional modeling, runs without user interaction, and tolerates missing parts of the head circumference in the image volume, as usually the case with PET. Thereafter, high-resolution MR sections corresponding to the PET slices are reconstructed from the spatially transformed MR data. In a phantom study of this method, PET/MR alignment of the phantom's surface was accurate with average residual misfits of 2.17 to 2.32 mm as determined in three orthogonal planes. In-plane alignment of the phantom's insertion holes was accurate with an average residual misfit of 2.30 mm. In vivo application in six subjects allowed the individual anatomical localization of regional CBF (rCBF) responses obtained during unilateral manual exploration. In each subject, the maxima of the rCBF activations in the hand area were precisely allocated to gray matter in the anterior or posterior wall of the central sulcus. The configuration of the rCBF responses closely followed the gyral structures. The technique provided a better topographical understanding of rCBF changes in subtraction images of PET activation studies. It opens the perspective for studies of structural-functional relationships in individual subjects.
Background. A monoclonal antibody, Ki-67, recognizes an antigen expressed in all phases of the cell cycle, except G0, and can be used as a simple histologic marker of cell proliferation. To assess the prognostic value...
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Background. A monoclonal antibody, Ki-67, recognizes an antigen expressed in all phases of the cell cycle, except G0, and can be used as a simple histologic marker of cell proliferation. To assess the prognostic value of the growth fraction in non-Hodgkin lymphoma of Waldeyer ring (W-NHL) and the nasal cavity (N-NHL), the authors applied Ki-67 immunostaining combined with image analysis on such lymphomas. Methods. The authors studied 29 patients (18 with W-NHL and 11 with N-NHL), applying Ki-67 to frozen sections. The number of Ki-67-positive cells in a unit area (0.044 mm2), as an indicator of proliferative activity, and the mean area per Ki-67-positive cell (mum2), as an indicator of DNA content, were measured by the imageprocessing system. Results. High-grade lymphomas showed a significantly larger number of Ki-67-positive cells than intermediate-grade lymphomas (102.5 +/- 21.6 in high-grade and 46.8 +/- 8.92 in intermediate-grade lymphomas, P = 0.03), even when analyzed separately by immunopheinotypes. A large mean area per Ki-67-positive cell was associated significantly with a T-cell phenotype (36.3 +/- 7.69 mum2 in T-cell lymphomas and 19.4 +/- 2.33 mum2 in B-cell lymphomas, P = 0.034) and an unfavorable clinical outcome. High proliferative activity, defined as nuclear Ki-67 expression in 2000 or more B-cell lymphoma cells and 1000 or more T-cell lymphoma cells in a 1-mm2 area, was found to be a strong predictor of poor survival among these patients (P = 0.048 and P = 0.009, respectively). Conclusions. Ki-67 immunostaining, combined with image analysis, is a novel method for determining a tumor proliferative index that provides useful clinical data regarding head and neck lymphomas.
To determine whether the increase in oxidative capacity after respiratory muscle training with chronic inspiratory loads in sheep is specific to a particular fiber type, we measured cytochrome c oxidase (COX) activity...
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To determine whether the increase in oxidative capacity after respiratory muscle training with chronic inspiratory loads in sheep is specific to a particular fiber type, we measured cytochrome c oxidase (COX) activity in type I and type II fibers. COX activity in individual fibers was examined histochemically and measured as relative optical density by use of an imageprocessing system. Fiber types were differentiated by the myosin adenosine-triphosphatase reaction. We found that COX activity was higher in both fiber types in the trained diaphragms than in the control diaphragms (P < 0.01). The increase with training was greater in type II (39%) than in type I fibers (21%), resulting in relatively homogeneous COX activity in all diaphragmatic fibers. The proportion of type I fibers increased from 43.4 +/- 5.4% in the control diaphragm to 53.1 +/- 2.9% in the trained diaphragm, whereas the proportion of type II fibers decreased (P < 0.001). We conclude that respiratory muscle training activates oxidative enzyme activity in both diaphragmatic fiber types;this activation is differentially more in type II fibers, which also decrease in proportion, and less in type I fibers, which increase in proportion.
A neural network simulator was used for the recognition of the presence and location of the peak of wave V of the brain stem auditory evoked potential (BAEP) test. Waveforms selected from BAEPs performed in the last 4...
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A technique is described which allows precise assessment of the topographical relationship between the estrogen receptor (ER) and the progesterone receptor (PR) in the same histological section. It is based on the ana...
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A technique is described which allows precise assessment of the topographical relationship between the estrogen receptor (ER) and the progesterone receptor (PR) in the same histological section. It is based on the analysis of the results of immunohistochemical double staining by computer-assisted image processing. Five human ductal breast cancers were examined. The simultaneous demonstration of both receptors consists in the following principal steps:
A microcomputer based imageprocessing system has been developed to analyze the density of immunohistochemical labeling within neural tissue. The system permits the tracing of anatomical regions seen on a digitized im...
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A microcomputer based imageprocessing system has been developed to analyze the density of immunohistochemical labeling within neural tissue. The system permits the tracing of anatomical regions seen on a digitized image and the determination of the area and the mean gray level of all pixels lying within each defined region. Corrections are made for uneven screen illumination and for nonlinearity of the video camera''s response to graduations in optical density. A standardization procedure ensures that the same level of incident illumination is used during each experiment. An example of an application of this system is described in which unilateral changes in immunohistochemical staining density were determined within the rodent spinal cord following partial spinal injury. This system provides a sensitive and objective means of analyzing such changes.
A computer-based video imageprocessing system is described that quantifies the binding of the neuroleptic drug, [3H]spiroperidol, to rat forebrain sections. Adjacent sections were incubated in buffer containing [3H]s...
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A computer-based video imageprocessing system is described that quantifies the binding of the neuroleptic drug, [3H]spiroperidol, to rat forebrain sections. Adjacent sections were incubated in buffer containing [3H]spiroperidol or [3H]spiroperidol plus 1 .mu.M (+)-butaclamol and exposed to [3H]-sensitive film to produce autoradiographs of total binding or non-butaclamol-displaced (non-specific) binding. The imageprocessing system digitized each autoradiograph, attenuated geometric distortion and unevenness of background illumination and reassigned the digitized image intensities (gray values) to be a linear function of fmol [3H]spiroperidol bound per mg protein by using a calibration curve generated from 3H-containing tissue standards. An image of butaclamol-displaced (specific) [3H]spiroperidol binding was produced by subtracting the linearized image of non-specific binding from the superimposed image of total binding. An image of percent specific [3H]spiroperidol binding was obtained by dividing the image of specific binding by the superimposed image of total binding. The computer-derived images, which could be displayed in gray tones or pseudocolor-coded, revealed that the greatest amounts of specific [3H]spiroperidol binding (1000-300 fmol/mg protein;60-80% specifically bound) were located in layers 5A and 5C of the neocortex, the claustrum and in the caudate-putamen, where a lateral-to-medial binding gradient occurred. [3H]Spiroperiodol was bound to a lesser extent (400-1000 fmol/mg protein;31-51% specifically bound) to the medial nucleus accumbens septi or olfactory tubercle and without measurable specificity to the lateral septum, anterior commissure, corpus callosum or superficial neocortex. These procedures are particularly useful for the quantitative and visual analysis of autoradiographs in which [3H]ligand binding is associated with more than a single site.
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