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Biomedical subjects

M C Poole

Publications and source records attributed to M C Poole.

3 recordsLinked to original sources

An image processing/stereological analysis system for transmission electron microscopy.

This study examines the feasibility of combining computer image digitization, image enhancement, and point counting stereological techniques to quantify video images from transmission electron microscopes (TEM). The essential hardware consists of an IBM PC/AT, a Matrox imaging board, a digitizing tablet, a high resolution black and white monitor, and a portable mass storage device. In addition a video camera must be mounted to the TEM. The software is written in three modules which have numerous routines for image acquisition, enhancement, and quantification. Quantification is achieved by selecting an electronic lattice and superimposing it on the cell image. A cursor is moved on the lattice (via the digitizing tablet) and the points are entered into a spreadsheet. One of the major limitations of the system was the reduced resolution inherent in the current hardware. However, sampling experiments showed that one could compensate for the reduced resolution by increasing the magnification of the digitized images, and the stereological values from digitized images compared favorably to those from electron micrographs. Furthermore, the system proved advantageous by eliminating the usual darkroom work, and in enhancing low contrast tissue. In spite of several hardware limitations, the concept of quantifying computer digitized TEM images appears promising.

Animals

Alteration of the mammotroph Golgi complex by the dopamine agonist 2 Br-alpha-ergocryptine (CB-154) in ovariectomized estrogen primed rats.

The present study examined the acute effects of 2 Br-alpha-ergocryptine (CB-154, a dopamine agonist) on mammotroph organelles during prolactin (PRL) suppression. Ovariectomized estrogen-primed rats received a single injection (sc) of 0.5 mg CB-154 and the animals were killed at intervals following injection. The anterior pituitary glands were fixed for electron microscopy and immunocytochemistry was used to confirm mammotroph identification. Serum PRL levels were determined by RIA. Following CB-154 administration, serum PRL was significantly (P less than 0.05) reduced within 15 minutes and was suppressed (P less than 0.01) to ovariectomized levels at 2 and 6 hours. A stereological analysis of mammotrophs in the central regions of the anterior pituitary showed that the Golgi complex volume was significantly (P less than 0.05) reduced at 2 hours after CB-154 treatment. However, the Golgi complex volume had recovered by 6 hours post CB-154 injection. In addition, the volumes of the mammotroph cells, the mature secretory granules, and the secondary lysosomes had significantly increased by 6 hours. There were no significant changes in any of the organelles following CB-154 in the mammotrophs from the peripheral regions of the gland. These studies show that the Golgi complex is especially susceptible to acute morphological changes induced by bromocryptine and that the mammotrophs in the central regions are more responsive to CB-154 than those in the peripheral regions.

Animals

A computer program for the morphometric analysis of cell profiles.

A computer program which yields values for the volumes, surface areas, and volume/surface area ratios of cell profiles is described for use on a desktop calculator (minicomputer). This program uses standard morphometric procedures, and incorporates data obtained from electron micrographs at two levels of sampling. The main program yields values for the 'average cell volume' at the tissue level of sampling. Two options at the cellular level of sampling are also included which yield values for the volumes, surface areas and volume/surface area ratios for the organelles. The first option allows an analysis of 'whole cells' containing equatorial profiles through the nucleus, while the second option permits a 'fractional' approach using segments of the cells. Finally, some of the advantages of the two options are discussed.

Cell Count