摘要:

The distribution of actin in spermatids and epididymal spermatozoa of the mouse was examined by electron microscopy with immunogold procedures using two monoclonal antiactin antibodies. Actin was identified by immunoblotting of proteins extracted from either whole spermatozoa or tail fractions. In round spermatids, actin immunolabeling was detected in the subacrosomal space. Labeling increased during the elongation phase, and then decreased and completely disappeared before spermiation. No labeling was found in epididymal spermatozoa and residual bodies. Our results suggest actin redistribution or the absence of G-actin from the head to the flagellum in mature murine spermatids, as previously shown in other studies in various mammals.

ISSN:1422-6405    

DOI:10.1159/000147493

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

An infant with congenital absence of the nostrils, incomplete prolabium, incomplete premaxilla, nasal cavity without septum, and cleft palate is presented. To clarify the embryological development of the nostril, serial sections of many embryos and fetuses of various stages were examined. Recanalization of the nostril, resulting from resorption of the temporary nasal epithelial plug, was observed in a 13- to 15-week fetus. Although textbooks of human embryology describe its occurrence in the 6th month or 24th week of fetal life. This finding suggests that the embryological cause of congenital nostril atresia, in the present case, may have been persistence of the plug.

ISSN:1422-6405    

DOI:10.1159/000147494

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The occurrence and fine structure of Merkel cells with melanosomes in the labial epithelium of the dog and cat were studied by electron microscopy. These melanosomes were polarized in the Merkel cell cytoplasm opposite to the major aggregation of dense-cored granules and the closely abutting nerve terminal. None of melanosomes was found in the Golgi complex region where a few immature dense-cored granules were observed. This may suggest that the melanosomes are not produced in the Merkel cell, but are taken from the melanocytes like in keratinocytes. The possible phagocytotic ability of Merkel cells is discussed.

ISSN:1422-6405    

DOI:10.1159/000147495

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Linear structures were occasionally found on the lingual surface of the cementum of infant rat incisors along the long axis of the incisors, which are teeth that grow continuously from a persistent odontogenic organ. The observations strongly suggest that these linear structures on the junctional line of Hertwig’s epithelial ‘root’ sheaths correspond to the seams on the multirooted molar teeth of

ISSN:1422-6405    

DOI:10.1159/000147496

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The ultrastructure of parathyroid glands of hypophysectomized rats in normo- and hypocalcaemic conditions was qualitatively and quantitatively analysed. Parathyroid glands of both intact and hypophysectomized rats comprised cells of similar shape and staining intensity and of an equal number of cells in mitosis. Cell volume was not affected but the surface area of plasma membrane, RER and Golgi complex was increased in parathyroid cells after hypophysectomy. Parathyroid cells of both intact and hypophysectomized rats responded to hypocalcaemia by a drastic increase in surface area of the plasma membrane and a decrease in surface area of the Golgi complex. Since RER, Golgi complex and plasma membrane are concerned with secretion of parathyroid hormone, the data suggest that (1) the pituitary has either no effect on parathyroid cells, or a possibly stimulating effect can be compensated after hypophysectomy, or the pituitary even has a suppressive effect on parathyroid cells, and (2) the responsiveness of parathyroid cells to changes in serum calcium is unimpaired after hypophysectomy.

ISSN:1422-6405    

DOI:10.1159/000147497

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Elastic fibers are important components of the connective tissue that attaches the articular disk of the craniomandibular joint (CMJ) to the skull and mandible. Biopsies of the articular disk proper and bilaminar zone (BZ) tissues from patients with anterior disk displacement (ADD) have shown previously that there is a marked loss of elastic fibers. In the present study, the effects of inducing ADD on the elastic fibers in the rabbit CMJ disk proper, BZ and condylar cartilage were investigated. The right CMJ was exposed surgically and the discal attachments were severed except for the BZ attachments. Then, the disk was displaced anteriorly and sutured to the zygomatic arch. The CMJs were removed after 1 2 or 6 weeks and processed for histochemical demonstration of elastic fibers. The results showed osteoarthritic changes following ADD, and a significant decrease in the number of the elastic fibers in the disk proper and BZ. The remaining elastic fibers were abnormal in their appearance and orientation. In addition, ADD led to the appearance of fine elastic fibers among the chondrocytes in the hyaline cartilage of the condyle that were not present in the cartilage of the control condyle. We conclude that induced ADD can lead to a significant loss of elastic fibers in the articular disk, and result in the appearance of elastic fibers within the cartilage of the mandibular condyle.

ISSN:1422-6405    

DOI:10.1159/000147498

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Non-obese diabetic mice were administered 150 mg/kg body weight of Cronassial daily from the 5th to the 11th week of life. Animals were killed either at the end of the treatment with Cronassial (week 11) or at week 21. The results obtained demonstrated that the appearance of the insulitis in control and treated animals at 11 and 21 weeks did not show a significant difference. The only effect of ganglioside treatment was to slow the rate of rise in glycaemia and the progression of the islet cyto-architectural derangement. In our opinion, this is not sufficient to prove the effectiveness of this drug in reducing the final diabetes incidence.

ISSN:1422-6405    

DOI:10.1159/000147499

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Harderian glands of female and male Siberian hamsters (Phodopus sungorus) were studied after a subcutaneous injection of 3H-dihydroxycholecalciferol (vitamin D, soltriol). Autoradiograms revealed the presence of nuclear concentration of the hormone in certain alveolar cells and in myoepithehal cells. The proportion of labeled cells varied between 5.5 and 19% of the total cell number, with an average of 9.5% in female and 12.4% in male hamsters. The data suggest that the functions of the Harderian gland could undergo seasonal changes under the control of vitamin D.

ISSN:1422-6405    

DOI:10.1159/000147500

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

This study performed by intraneuronal tracing directly demonstrates the presence of sympathetic postganglionic fibers in the cranial vault of the rat. Superior cervical sympathetic ganglia were injected with horseradish peroxidase (HRP), and after a 48-hour period, to permit anterograde axonal transport, the animals were sacrificed after in situ perfusion. An area of the calvaria that included portions of the frontal and parietal bones was fixed, decalcified and sectioned. HRP-containing axons were localized in the developing frontal and parietal bones of the calvaria. Adrenergic innervation was not demonstrated in sutural tissue (superior sagittal, coronal or metopic) by this technique. To our knowledge, this study is the first to trace sympathetic nerve fibers in the rat calvaria by intra-axonal transport of HRP.

ISSN:1422-6405    

DOI:10.1159/000147501

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The catecholaminergic innervation of neurons that contain oxytocin in the paraventricular nucleus (PVN) of the rat hypothalamus was examined by a combination of methods in the same tissue sections at the electron-microscopic level as follows: (1) Rats were treated with 5-hydroxydopamine (5-OHDA) with peroxidase-antiperoxidase (PAP) staining of sections for oxytocin prior to embedding. (2) Preembedding immunoperoxidase staining with avidin-biotin complexes was used to demonstrate tyrosine hydroxylase (TH) activity, with postembedding staining with immunocolloidal gold for visualization of oxytocin. (3) Prior to embedding, a double-staining technique was used that was based on consecutive staining with silver-gold-intensified PAP complex and 3,3’-diaminobenzidine. We used an antiserum against oxytocin and an antiserum against dopamine-β-hydroxylase (DBH) for localization of antigens. We found that TH- and DBH-like immunoreactive terminals were distributed throughout the rat hypothalamus and were abundant in all parts of the PVN. Ultrastructural observations revealed 5-OHDA-labeled, TH- or DBH-like immunoreactive axon terminals that contained granular vesicles (70-80 nm in diameter) and small clear synaptic vesicles (30-50 nm in diameter). The terminals appeared at times to be making synapses with cell bodies and with the processes of oxytocin-containing neurosecretory neurons in the PVN. These findings provide morphological evidence for a direct synaptic influence of catecholaminergic elements on the secretory activity of oxytocin-containing neurosecretory neurons in the rat hypothalamic P

ISSN:1422-6405    

DOI:10.1159/000147502

出版商:S. Karger AG    

年代:1993

数据来源: Karger