摘要:

Both organ culture (chorioallantoic membrane) of striped muscle from mouse diapharagm and freeze-drying of myocardial cells presented very characteristic structures in mitochondria. The organ culture evidence ‘rod-like structures’ in the intracristal spaces of the cristae mitochondriales. It is believed that these structures are the central apparatus responsible for mitochondrial division. On the other hand, the freeze-dried mitochondria presented neither intracristal spaces nor a space in the outer mitochondrial membrane. Because these spaces appeared only after fixation and dehydration, it is discussed if they are really artifacts. The mitochondrial cristae appearing as united structures after the freeze-drying process have been compared to the rod-like structures appearing intracristally after organ culture and conventional preparation techniq

ISSN:1422-6405    

DOI:10.1159/000144992

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The number of the various cell categories of the exocrine pancreas of the rat was evaluated by morphometric methods in paraffin sections of glands from rats aged 2, 5,15, 20 and 33 days. The evolution of these cell types could be properly expressed by equations of the type y = a0 e k·x, where ÿ = cell number, and x = age in days. The time necessary for each cell type to duplicate was thus obtained. The percentages (y’) of acinar, intercalated duct and connective tissue cells also proved to be age-dependent and could be expressed by second-degree equati

ISSN:1422-6405    

DOI:10.1159/000144993

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The first mandibular molars of the Swiss albino mice, 1 through 4 days of age, were fixed in glutaraldehyde or Karnovsky’s fixative. The tissues were postfixed in Os04, dehydrated and embedded in Epon. The prepolarizing, polarizing and secretory odontoblasts were described. The prepolarizing cells, located in the vicinity of the cervical loop, were mesenchymal-like in morphology. The cells of the polarizing stage possessed organelles indicative of protein synthesis. The nucleus was located proximally. Aperiodic fibers were evident in the wide basement membrane. The secretory odontoblasts were long, slender, polarized cells closely adjoining one another. Each odontoblast possessed six morphologically discernible regions: (1) an infranuclear region, limited in size and containing few cellular organelles; (2) a nuclear region, housing the oval nucleus and a few associated lamellae of rough endoplasmic reticulum as well as a limited number of mitochondria; (3) a supranuclear rough endoplasmic reticulum region, possessing an abundance of these organelles as well as some mitochondria and secretory vesicles; (4) a Golgi region, occupying the middle third of the cell, housing the elements of an extensive Golgi apparatus which was surrounded by peripherally located profiles of rough endoplasmic reticulum; additionally, this region contained smooth endoplasmic reticulum, mitochondria, numerous secretory granules and vesicles and occasional intracellular collagen fibers; (5) an apical rough endoplasmic reticulum region, containing a rough endoplasmic reticulum component that was less extensive than its supranuclear counterpart; in addition, this region was the one richest in mitochondria and contained a plethora of secretory vesicles and granules; (6) the odontoblastic process, a region mostly void of organelles, containing various secretory products, some of which appeared to be in the process of being released extracellularly into the surrounding dentin matri

ISSN:1422-6405    

DOI:10.1159/000144994

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The distribution of the dopamine (DA) cell bodies was elucidated within the mouse arcuate nucleus by fluorescence histochemistry. The arcuate nucleus was divided into five regions; heterogeneity in distribution and different amounts of DA among the regional areas were demonstrated. The DA cell bodies containing a large amount of DA, observable even in the arcuate nucleus of the intact mice, distributed in the medial areas of the anterior-central and the middle-central regions and in the dorsal area of the posterior-central region. On the other hand, those containing probably a small amount of DA distributed in the medial area of the rostral region and in the ventral areas of the anterior-central and middle-central regions. They were not observed in the intact mice, but found in the mice treated with nialamide plus α-methyldopa. No DA cells were found in the caudal region

ISSN:1422-6405    

DOI:10.1159/000144995

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The authors studied the embryonic development of the pineal gland of the chicken with the electron microscope. The denomination of ‘pinealoblasts’ was given to the undifferentiated cells which form the primitive pineal outline. In the wall of the pineal cavities, the follicular and parafollicular zones were distinguished; these are formed by type A and type B pinealocytes, the B type being much more abundant. The degenerated cells are constant in the pineal throughout its embryonic development, but much more abundant in the early pha

ISSN:1422-6405    

DOI:10.1159/000144996

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Using histochemical methods, the presence of acidic glycosaminoglycans in the cell nuclei of 51 human irides and a series of monkey organs was demonstrated. In general, these substances are sensitive to testicular hyaluronidase and chondroitinase ABC and also to Streptomyces hyaluronidase, when using special staining methods. The specificity of testicular hyaluronidase was tested by. inhibition with heparin. By simultaneously staining with alcian blue and Feulgen, acidic glycosaminoglycans can be distinguished from the nucleic acids. Sporadically, hyaluronidase-resistant substances with a specific acidic glycosaminoglycan stainability occur. We assume the existence of various acidic glycosaminoglycans in the cell nuclei. Aging changes were not traceable with constancy.

ISSN:1422-6405    

DOI:10.1159/000144997

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The pars distalis of 1 girl and of 3 sexually mature women was studied. The glands were dissected out and fixed within a period of 30 min following death; in the aldehyde fixative, each gland was systematically divided into ten pieces. Before fixation in osmium tetroxide, each piece was again divided into several blocks. At least 60 blocks were obtained from each gland. Semi-thin sections obtained from all the blocks were stained and studied under the light microscope. Ultrathin sections were obtained from selected blocks. Under the light microscope, 6 types of secretory cells and 2 types of non-secretory cells were characterized. At the ultrastructural level, 7 types of granulated cells and 2 types of non-granulated cells were distinguished. The range of the granule size for each type of secretory cell was determined by applying a mathematical model and a computer program that corrected the size distribution curve in such a way that only the diameter of the equatorial sections of the granules, that is the real granule sizes, was recorded. By comparing the observations made in the ultrastructural study with those performed in adjacent semi-thin sections it was possible to correlate the cell types characterized ultra-structurally with those distinguished under the light microscope. In addition, the study of the semi-thin sections made it possible to quantitatively analyze the different cell types, while the ultrastructural characteristics suggested the probable functional role of each of these cell types.

ISSN:1422-6405    

DOI:10.1159/000144998

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

A new grinding machine for preparing thin undecalcified bone sections after methylmethacrylate embedding is described. About 20 rather small bone sections can be ground at the same time; bigger specimens, up to 8 cm of length, are allowed. Bone sections are mounted on a cylindrical specimen holder by an adhesive film. Then the final thickness of the sections is exactly adjusted by screwing three rubies out of the holder’s bottom. Now the prepared holder is set in a guide ring on a turntable carrying a rough ended glass plate. The desired thickness of the sections is reached as soon as the three rubies touch the glass surface. The variation in the thickness of the sections is less than ± 3 μm. The machine is simply constructed, easily to handle and rapidly to cl

ISSN:1422-6405    

DOI:10.1159/000144999

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The nerve elements in the urinary bladder of the cat were studied by electron microscopy. According to their ultrastructure, nerve cell somata can be classified into three types: the large cells with a cytoplasm rich in organelles, several processes and numerous synaptic contacts on their surface; the cytoplasm contained 80- to 120-nm granulated vesicles. The second type is poor in cytoplasmic organelles and has very few processes and virtually no synaptic contacts on the soma. The third type contains numerous large 160- to 220-nm ‘neurosecretory’ vesicles in the cytoplasm. According to the morphology of the vesicle population, four types of nerve processes could be distinguished: Type a, with a dominant population of small (40–60 nm) agranular vesicles. These are thought to be sacral parasympathetic fibres. Type b, with small (40–60 nm) granular vesicles, which may be the noradrenergic sympathetic fibres. Type c, with 80- to 120-nm granulated vesicles, probably of local origin. Type d, with large 160- to 220-nm ‘neurosecretory’ vesicles also of local origin. Different types of nerve fibres are converging on the local nerve cells. This suggests that the local circuits can play an important role in coordinating the function of the bladder. Therefore, ganglia may be considered as an elementary func

ISSN:1422-6405    

DOI:10.1159/000145000

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The digest of the pure epidermis preparation from Macaca mulatta demonstrated three types of dendritic cells i.e. (1) dopa-positive melanocytes, (2) dopa-negative Langerhans’ cells and (3) weakly dopa-positive intermediate cells of Billingham and Medawar. The last type of cell was found to have characteristics being intermediate between those of the melanocytes and of the Langerhans’ cell. A similar digest prepared from the epidermis of the rhesus monkey demonstrated isomorphous dendritic cells which were all dopa-negative. Here also the intermediate cells of Billingham and Medawar with characteristics intermediate between those of the melanocytes and of the Langerhans’ cells were ident

ISSN:1422-6405    

DOI:10.1159/000145001

出版商:S. Karger AG    

年代:1979

数据来源: Karger