摘要:

A study on thyroid glands of Wistar rats of ages ranging from 1 to 120 days was carried out. The glands were serially sectioned and stained for calcitonin using the peroxidase antiperoxidase method. All the thyroids contained ultimobranchial follicles (UBF) located partially embedded among the usual follicles but in a 5-day-old rat this structure showed an unusual position in the interstitium of connective tissue between the cartilage of the trachea and the thyroid gland. We have observed in the wall of that UBF the presence not only of resting C cells but also mitotic figures of C cells. Furthermore, on the opposite side of the same UBF an active area of formation of thyroid follicles was found. These observations provided the first evidence of the contribution of the UBF in the formation of C cells during the postnatal life of the rat. Furthermore, it is suggested that some C cells may share a common origin with ultimobranchially derived follicular cells.

ISSN:1422-6405    

DOI:10.1159/000147290

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The sacroiliac ligamentous apparatus was examined as a part of a biomechanical pelvis-lower extremities system. The ligamentous apparatus of two pelves was freed, and the findings concerning the ligaments and their direction were drawn by a modular constructed, three-dimensional calculator model of the pelvic region. The ligamentous apparatus of the sacroiliac joint belongs to a functional system. Its task is to minimize every movement in this amphiarthrosis. The ligamentous apparatus shows an adaption to strong or long-time-acting stresses. The junction between the os sacrum, pelvis and the ligamentous apparatus of the sacroiliac joint can be described as self-tightening. Local stresses are also reduced by the ligaments. A loosening in this system, which has to fix the os sacrum to the pelvic girdle, leads to a static insufficiency. The consequence is pain due to an irritation of the lumbosacral trunk. The exact description of the structure allows a representation according to the laws of similarity mechanics. With such a representation one can build up a computer-aided biomechanical model of the pelvis-lower extremities region. Examples for such a model are biomechanical finite-element models. By observing the laws of similarity mechanics (an exact description of geometric, physical and functional conditions) an efficient biomechanical model can be constructed that also takes into consideration the complex functional circumstances, in contrast to previous models. In order to construct such a model, one has to feed the findings of the examination into a data bank, which has to be demanded.

ISSN:1422-6405    

DOI:10.1159/000147291

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Inbred female mice of the NMRI strain were treated subcutaneously with 5 µg diethylstilbestrol (DES) in olive oil or vehicle only for the first 5 days after birth. One group of DES-treated females was killed at the age of 8-12 weeks, and the uterine cervix and adjacent parts of the vagina and uterine horns prepared for histological studies. In all preparations, the cervical epithelial lining contained regions with heterotopic columnar epithelium (HCE) along 69-100% of the length of the common cervical canal. Ovaries from neonatally DES-treated females were grafted to 8-week-old ovariectomized control hosts and these hosts were mated to control males 2 weeks later. The hosts gave birth to normal-sized litters. The female offspring from these litters had a normal cervical epithelial lining and, in turn, gave birth to normal-sized litters. These results indicate that treatment of neonatal female mice with DES does not affect the female germ cells as far as concerns factors associated with the development of HCE or reduced fertility in the next generation

ISSN:1422-6405    

DOI:10.1159/000147292

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

A particular nerve bundle which may be called phrenicosuprascapular communication is, although only rarely, met with in various forms in man. By teasing, fibres of this communication are revealed to belong to the most anterior components of the brachial plexus, being closely associated with anterior nerves such as the phrenic, accessory phrenic, subclavius and even pectoralis. It is, therefore, obvious that the nervus suprascapularis conveys anterior fibres. It may be interpreted that the anteriormost nerve fibres may be separated from the main cord(s) and form an irregular network or plexus for themselves. It should be stressed that the n. suprascapularis consists of all the anterior components of the brachial plexus and that this is an anterior nerve.

ISSN:1422-6405    

DOI:10.1159/000147293

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The direct effects of ethanol and caffeine on embryogenesis were investigated using the whole rat embryo culture system. Compared to control embryos, the crown-rump length, number of somites, branchial bars, and morphological score were significantly reduced in embryos exposed to ethanol, caffeine, or both substances. Development of the craniofacial region, cardiac primordium and forelimb was delayed following ethanol treatment. Compared to the controls, the anterior neuropore lagged in development following caffeine treatment; closure of the posterior neuropore was significantly delayed in each of the treatment groups. The optic and olfactory primordia were not affected. The results indicate that alcohol and caffeine independently affect the embryo, but when combined their effects were not potentiated.

ISSN:1422-6405    

DOI:10.1159/000147294

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The paranasal or accessory nasal sinuses begin their development as evaginations of the mucosa during the 3rd and 4th fetal months, but undergo their major expansion afterbirth according to the development of the facial cranium and the teeth. While in the newborn the sphenoidal and frontal sinuses are still only pre-dispositioned, the ethmoidal labyrinth and particularly the maxillary sinus are of appreciable size. In the 4-year-old the frontal and sphenoidal sinuses are already developed and in the 12-year-old the paranasal sinuses reach their final form and a size equivalent to the adult.

ISSN:1422-6405    

DOI:10.1159/000147295

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

A morphoquantitative analysis was carried out to clarify the cytoarchitectural organization of the paramedian pontine reticular formation (PPRF) which is considered to be an important site in the control of eye movements. The study was carried out on the cat, using the Golgi staining method. The topographic position and detailed structure of the neurons were demonstrated using morphoquantitative methods. On the basis of their neuronal arborization, fusiform neurons and two types of multipolar cells were identified. Fusiform neurons show dendrites which are given off from the two poles of the small- to medium-sized cell body. The arborization generally runs caudorostrally, ending inside the PPRF. These neurons are ubiquitous. Type 1 multipolar neurons, the most frequent elements of the neuronal population (60%), have a small- to large-sized cell body from which 2 or 3 primary spiny dendrites and the axon emerge. Their dendritic field is oval and generally oriented in the vertical plane. These neurons are scattered everywhere in the PPRF. Type 2 multipolar cells are large neurons endowed with numerous primary spiny dendrites constituting a wide round dendritic field and with a thick axon. They are located almost exclusively at the boundaries of the PPRF and preferentially in the caudal region. The characteristics of the neurons suggest that the fusiform cells may play an interneuronal role, while the multipolar neurons could have both a projective function and an important receptive role for the afferent fibers to the PPRF. The lack of homogeneity found among the multipolar neurons is in agreement with the variety of projective elements shown by functional investigations. This study which describes the detailed pattern of the neuronal population provides the structural support for the many morphofunctional and physiological studies of the PPRF.

ISSN:1422-6405    

DOI:10.1159/000147296

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Morphological signs of severe ischaemic injury are well known. However, we still lack knowledge about how indices of milder injuries are related on a cellular level. In a previous study we have reported on the sequence of alterations across the border zone in cat hearts subjected to 3 h of coronary occlusion. In the present study, which elaborates that study, we have examined the relationship between morphological variables in serial sections of 220 myocytes within the border zone. In cells with intact sarcolemma and no chromatin changes, the fractional volume of cytoplasm has a bimodal distribution indicating cells with and without oedema. Whereas cells with focal disruptions of the sarcolemma have a moderate oedema, usually localized submembranously, cells with extensive sarcolemmal fragmentation have an extensive oedema. A mild oedema is seen before other signs of severe cell injury, even though more extensive oedema is closely associated with sarcolemmal fragmentation. The fractional volume of mitochondria was smaller, whereas the fractional volume of lipid droplets was larger in cells with oedema than in cells without oedema.

ISSN:1422-6405    

DOI:10.1159/000147297

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The anatomical basis for the application of neurovascular pedicled muscle transfers of the digastric and stylohyoid muscles in the treatment of velopharynx incompetence is described. The fact that the neurovascular pedicle is located in the cranial third of the muscle bellies provides the safety of the operative procedure. The muscles have to be dissected with respect to that. The direction in which the transferred muscles pull is described. The muscle transposition is combined with the classic Wardill-Kilner operation to lengthen the soft palate. The transferred muscles have to avoid scar contraction and shortening of the soft palate and to gain a muscular function of the soft palate. The clinical use is justified in rare cases as demonstrated in one case.

ISSN:1422-6405    

DOI:10.1159/000147298

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

In 30 human fetuses between 8 and 13 weeks of intrauterine life the lateral wall of the nasopharynx was examined by light microscopy and transmission am scanning electron microscopy. In the subjects between 8 and 9 weeks in utero the mucosa displays still an immature appearance, being mono- or bistratifiet and lacking the characteristic structures of the respiratory epithelium. Nevertheless, signs of differentiation are to be noticed, with the presence of two distinc cellular types that, in the later periods, will give rise to ciliated cells and microvillus-provided cells. An almost complete differentiation will be reached at 12–13 weeks in utero, even if goblet cells are still lacking in the examined zone during the considered period. Nonrespiratory types of epithelium, such as transitional or squamous, were never found in the studied subject

ISSN:1422-6405    

DOI:10.1159/000147299

出版商:S. Karger AG    

年代:1992

数据来源: Karger