摘要:

Intranuclear microtubular-microfilamentous rod-like inclusions were investigated in chromaffin cells of the auricle of the heart of lungfishes. In conventional electron microscopy, these inclusions reveal a wide variety in appearance, depending on their orientation to the plane of sectioning. Whereas originally they were merely interpreted as a bundle of microfilaments, application of a goniometer stage showed the rod- or spindle-shaped intranuclear inclusions to have a basic substructure of parallel arranged microtubules among microfilaments, which are clearly connected to chromatin granules, occasionally penetrating dense areas of chromatin.The chemical nature and biological significance of these structures, which so far remain enigmatic, are discussed.

ISSN:1422-6405    

DOI:10.1159/000146636

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The present study has attempted to determine the volume, square measure as well as length, width and thickness of the individual muscles of facial expression by photogrammetry. 15 fresh male head specimens were employed for a careful dissection of muscle layers. The volume was measured using the immersion procedure. The mean values of each parameter together with the standard deviation were summarized. The results suggest that this novelty in the representation of the mimetic muscles will facilitate the planning of corrective interventions in plastic surgery. Moreover, photogrammetry offers additional information on the required size and measurements of donor muscles.

ISSN:1422-6405    

DOI:10.1159/000146637

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Three- and four-day-old chicken embryos show normally a defect in the epithelium of the cloacal wall. This defect is not seen in human embryos at a similar developmental stage. Its signification is unknown.

ISSN:1422-6405    

DOI:10.1159/000146638

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

A correspondence between the appearance of vaginal smears and the layers of the epithelium from which the cells had desquamated was established in untreated rats during the estrous cycle, in control ovariectomized rats and in spayed rats injected with either estrogen or progesterone. The technique for preparing and staining the smears (modified Shorr’s staining procedure) is outlined. A simplified.system of classification which allows the accurate identification of the various stages of the reproductive state in the rat is described. Standing estrus, as well as the influence of estrogen on spayed rats, is characterized by marked cornification of the cells and the disappearance of leukocytes. At the end of estrus, the cornified layer is sloughed off and invasion by leukocytes occurs. During diestrus, as well as in untreated ovariectomized rats, the vaginal contents consistently lack cornified cells whereas leukocytes are very plentiful. Proestrus follows diestrus: the vaginal smear is devoid of leukocytes and characterized by nucleated epithelial cells. Pregnancy, as well as the influence of progesterone on ovariectomized rats, is also characterized by epithelial growth and desquamation but at different rates, resulting in the presence of intermediate cells, and polymorphs and mucus forming a noticeable background to the smear. Since vaginal smears display cell pictures characteristic for each hormone after administration of estrogen or progesterone, exfoliate cytology is a good indicator of the stage of the reproductive state in the ra

ISSN:1422-6405    

DOI:10.1159/000146639

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In order to give a neuroanatomical evidence to the mechanism of shifting from sucking to biting, we investigated in prenatal, newborn and postnatal mice whether there is a time difference in the neurogenesis of the neurons relative to sucking and biting or in the histogenesis of their peripheral effector organs by the HRP labeling technique and electron microscopy.The results obtained are as follows. (1) At birth the facial motoneurons exceed the trigeminal motoneurons in cell area and development. (2) After birth, the trigeminal motoneurons grow rapidly and outstrip the growth of the facial motoneurons at the age of 6 days. (3) Thereafter, the cell area of both neuron types continues to increase gradually. (4)The initial sign of the alpha motor end plates is found in the orbicularis oris muscle innervated by the facial nerve in 17-day-old fetuses, while that of the trigeminal nerve is delayed in the masseter muscle of 18-day-old fetuses. (5)The initial sign of the muscle spindle appears with the sensory terminals in the masseter muscle of 17-day-old fetuses and the fundamental structure of the muscle spindle is formed in 4-day-old youngs. (6) Myelination of the facial nerve begins in 3-day-old youngs, while that of the trigeminal nerve becomes apparent in 4- or 5-day-old youngs. From these bases, it is obvious that the facial nerve elements related to sucking are firstly developed at birth and that the differentiation of the trigeminal nerve elements related to biting is rapidly accelerated after birth.

ISSN:1422-6405    

DOI:10.1159/000146640

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The discovery of the papaverine erection test by Virag in 1982 stimulated the interest of research workers in the physiology of the penis. Since then, the scheme of functioning proposed by Conti [Acta anat. 14:217–262,1952] in 1952 has been frequently cited in the literature, although its finalism is evident. It is based upon the presence of regulatory mechanisms along penile arteries, veins and arteriovenous anastomoses. In spite of the fact that these anastomoses were unanimously admitted, recently the presence of arterial and venous cushions has been controverted or even denied. Before attempting any functional explanation using nerves and chemical mediators, we made sure first of the concrete material reality of these anatomical structures.Thirty-five years after the main study, the present observations confirm the morphologic descriptions made in 1952.The contrary would have been astonishing. In fact, arterial and venous cushions were demonstrated by the School of Anatomy of Padova, the most ancient and venerable of all (Fallope, 1550), then by other institutes of morphology that dealt with these cushions in practically all the organs of the human body. It remains to establish their role in erection – whether it is null, complementary or primordial: that is the quest

ISSN:1422-6405    

DOI:10.1159/000146641

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

By using X-ray cinemographic techniques and biomechanical methods, the open-closing movement of the human temporomandibular joint was investigated in 14 living subjects. The theory of the instantaneous center of rotation (IRC) of the mandibular movement is strongly recommended and the position and the tendency of the IRC are also roughly determined. Moreover, a two-step model of the joint is put forward.

ISSN:1422-6405    

DOI:10.1159/000146642

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The comparison of the hypophyseal pars tuberalis in active and in hibernating hedgehogs reveals different cytological characteristics in the specific secretory cells. In active animals, these cells show oval nuclei and the cytoplasm contains numerous secretory granules near or attached to the cell membrane, suggesting exocytotic release. In hibernating animals, the specific secretory cells are characterized by irregularly shaped and often invaginated nuclei. Clusters of secretory granules lying within the cytoplasm are often joined by lysosomes. These areas are observed to be encircled by cisterns of the endoplasmic reticulum. Degenerative processes in the structures sequestered in this way are interpreted as signs of crinophagy which has no equivalent in the cell types of the pars distalis.

ISSN:1422-6405    

DOI:10.1159/000146643

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Vascular casts were made of the choriocapillaris (CC) of rabbits that received sodium iodate intravenously 6–28 days prior to examination, in order to augment studies of CC regeneration in sectioned material. Regeneration of CC was evident 6 days after administration of iodate where zones of spared CC bordered zones of atrophic CC. Venular as well as capillary sprouts created foci of regenerating CC at this border. These foci subsequently enlarged by continued capillary branching and extension, and joined with adjacent foci to create an extended capillary plexus similar to mature CC. The observations corroborate those obtained in sectioned material as regards the geography of the CC response and the origins of new CC during the sodium iodate retinopathy, and provide new information on the way in which CC regenerate

ISSN:1422-6405    

DOI:10.1159/000146644

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In the present study, in order to easily grasp whole images of somatostatin (D) cells, the isolated mucosa of the mouse gastrointestinal tract was immunohistochemically treated. The present study revealed that: (1) in the stomach, small-intestinal villi and colon, about 20% of the D cells extrude basal cytoplasmic processes, showing terminal expansions in many cases; on the other hand, in the crypts of the small intestine, few D cells possess basal processes, and (2) in the stomach, there is no determined tendency in the direction of the basal processes of the D cells; on the other hand, in the small-intestinal villi and colon, most D cell basal processes run toward the villus base and colon crypt bottoms. The direction of the basal processes of the D cells in the gastrointestinal tract seems to be mostly in favor of the migration pattern of epithelial cells described previously. It is likely that, if the targets of the D cells are near the D cells the basal process is not necessary for local secretion of somatostatin. During migration however, D cells might extrude basal processes to keep relationships with their targets.

ISSN:1422-6405    

DOI:10.1159/000146645

出版商:S. Karger AG    

年代:1988

数据来源: Karger