Research progress of small-scale serial sections-based 3D reconstruction technologies / 国际生物医学工程杂志

3D reconstruction technologies have been widely used in medical diagnostic assist, surgical simulation, anatomy teaching, etc. The resolution of traditional imaging data such as computed tomography (CT) and magnetic resonance imaging (MRI) cannot meet the needs of life science research. Continuous sectioning technology can provide accurate and high-resolution information for the vast majority of tissues, which make it become a valuable method in the research and exploration of microstructures studies. With the development of microscopy and image processing techniques, significant advances have been made in the small-scale serial sections-based 3D reconstruction technologies. This enables the analysis of sample morphology and tissue function, as well as a more complete assessment of the structure of the tissue. Therefore, this technology has led to profound changes in the fields of cell and tissue biology. In this paper, the common small-scale serial sections-based 3D reconstruction technologies were compared and reviewed.

Immunohistochemical detection of axillary lymph node micrometastases in breast cancer patients: Increasing the accuracy of detection and decreasing labor intensive serial sectioning.

Background: The histological detection of axillary lymph node tumor metastases in cases of breast carcinoma is of major prognostic significance, but may be difficult when metastases are of microscopic size. The micrometastases can be detected either by immunohistochemistry (IHC) or serial sectioning. Aims: We investigated whether immunohistochemical techniques and serial sectioning can increase the accuracy of metastatic detection and compared the efficacy of both. Materials and Methods: Thirty cases of breast carcinoma were studied in all of whom the axillary lymph nodes had been reported as free of metastases. Blocks from these cases were serially sectioned and stained with hematoxylin and eosin and a single section was stained with monoclonal antibody to cytokeratin AE1/AE3 and epithelial membrane antigen. The positivity for micrometastases was correlated with size, number, grade and histological type of primary tumor, lymph node size and number. Results and Conclusion: In 5/30 previously unsuspected cases, micrometastases were revealed by IHC and in 1/30 by serial sectioning. These findings suggested that serial sectioning is a labor intensive, time consuming and impractical procedure. Micrometastases were more frequently detected with age of patient >50 years, Grade 2/3 tumor, tumor size >5 cm and more than one primary tumor. Immunohistochemical analysis can be recommended as a routine procedure or an adjunct to routine histological procedures for the correct staging of breast carcinoma and use of adjuvant chemotherapy, especially in the high risk group.

Methods for Serial Sectioning of the Brain Using a Meat Slicer and for Manufacture of the Permanent Specimens of Brain Slices / 대한해부학회지

It is important for the medical students to understand the horizontal planes of human normal brain. Particularly in recent decades, the popularization of magnetic resonance images has made the horizontal planes of brain more necessary. Color atlas of neuroanatomy or plastic models of brain have been widely used for this purpose. However, they are as nor realistic neither accurate as the human brain specimens. Thus, it is necessary to make educational tools of the human brain specimens. In most cases, brains are serially sectioned with 10 mm-thickness, but this is not sufficient for the close observation. Brains can be serially sectioned with 1 mm-thickness by using a polycut or cryomacrotome. However, those equipments cost high and the samples should be treated for a long period of time before serial sectioning. If the brain slices are preserved in the preservative solution, they can be easily damaged. In order to overcome this problem, the plastination method which allows plastic to penetrate into brain tissues was developed. However, this method costs high and requires the complex technique. Thus, we attempted to develop a rapid way to make the permanent specimens of brain slices with reasonable efforts using synthetic resin. A brain of 41 years old man cadaver was taken out and soaked in 10% formalin solution. The embedding box was made of acryl plate and acryl cylinder. An amount of 20% gelatin solution was poured into the embedding box and solidified to make gelatin bottom. The brain was put on the gelatin bottom, while the brain direction was adjusted for horizontal serial sectioning of the brain. 25% gelatin solution is poured and solidified to make gelatin cover. A brain block including brain, gelatin bottom and cover was extracted from the embedding box and the brain block was soaked in 10% formalin solution to make it suitably solid. The brain block was fixed on a meat slicer and serially sectioned at 5 mm-thickness to make 28 brain slices. The brain slices were dehydrated in glycerin solution, which was subsequently removed using paper towel. The permanent specimen molds were made of glass plate and acryl plates. An amount of synthetic resin mixture was poured into the permanent specimen mold and solidified to make synthetic resin bottom. Each brain slice was put on the resin bottom. Synthetic resin mixture was poured and solidified to make synthetic resin cover. Each permanent specimen including brain slice, synthetic resin bottom and cover is extracted from the permanent specimen mold. Margins of the permanent specimens of brain slices were trimmed using an electric acryl cutter and surfaces of the permanent specimens were grinded using an electric sandpaper machine and an electric polishing machine. Signs of the numbers and directions of brain slices were attached on the permanent specimens. Twenty eight horizontal brain slices were made; and each brain slice was processed to make a permanent specimen, so that 28 permanent specimens of brain slices were prepared. The permanent specimens showed the lean surfaces of brain slices with discrimination of the gray and white matters. Using the methods which have been developed in this research, the permanent specimens of brain slices can be made with relatively low cost and little time consuming, which will be practically helpful for neuroanatomy education.

SIMULTANEOUS DEMONSTRATION OF NEURONS AND NERVE FIBERS WITH SERIAL SECTIONING IN WHOLE CNS OF THE RAT / 解剖学报

Objective To explore a practicable method of serial sections of whole CNS in the rat, in which both neurons and nerve fibers were showed at the same section. Methods After perfused fixation and quick freezing, the tissues of whole CNS were cut into serial sections with cryostat followed by hematoxylin stain. Results The nerve fibers were stained in blue color while the neurons were showed black-blue and the background was light-yellow.Conclusion Our method was feasible to show both neurons and nerve fibers at the same section with quick freezing, freezing serial sectioning and improved hematoxylin staining.