摘要:

The otic capsules of several species were examined morphometrically and compared with the otic capsule of man. Area, perimeter and diameter of vessels, radius of tissue cylinder, circumscribing hexagon, intervascular distance, and O2 exchange area were evaluated. A correlation between occurrence and expansion of the interglobular spaces (‘Jnterglobularräume’) on the one hand and vascularization of the endochondral layer on the other hand was found. This corresponds to results of other authors concerning the persistence of cartilage observed in tissue cultures and long b

ISSN:1422-6405    

DOI:10.1159/000145126

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Differences in neurocranium growth at puberty were studied in rats of both sexes thymectomized and sham-thymectomized at 2, 4, 6, 8, 10, 12 and 14 days of age and in controls of matched age and sex; skull length, width and height, and skull base length and face length were measured. The neurocranium of the thymectomized rats was significantly smaller than that of the sham-thymectomized and control rats of both sexes and in all age-groups.

ISSN:1422-6405    

DOI:10.1159/000145127

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

A study of the median artery has been done on 40 forearms, using anatomical and radiological methods. Of the points studied, the following are of particular interest: the mode of origin and the systematization of the various types.

ISSN:1422-6405    

DOI:10.1159/000145128

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The effects of a maternal injection of trypan blue on primitive streak mouse embryos were studied with electron microscopy. Commercial trypan blue was purified by descending paper chromatography, and pregnant females received an intraperitoneal injection of the collected blue fraction on the evening of the 7th day of gestation. Ultrastructurally, the changes in the visceral endoderm were apparent 10 min after the injection and included an increase in the number of fuzzy-coated vesicles in the apical cytoplasm. By 20 min the apical cytoplasm of the extraembryonic visceral endodermal cells was filled with many fuzzy-coated vesicles and numerous vacuoles of various size and electron density. 30 min after the injection, the extraembryonic visceral endodermal cells were relatively smooth lacking a microvillous border and evidence of endocytic activity was rare. Many embryonic visceral endodermal cells were observed in various stages of degeneration although the underlying embryonic ectoderm appeared unaffected. Morphologically, it appears that trypan blue exerts its first effect by altering the endocytic activity of the visceral endoderm.

ISSN:1422-6405    

DOI:10.1159/000145129

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

In a series of 21 human fetal thyroid glands examined histologically in serial sections, seven ultimobranchial body cysts were found. The position of these cysts correlated well with the distribution of calcitonin-containing cells found by previous investigators in the adult thyroid gland. Ultimobranchial body cysts found external to the thyroid lobes may offer a developmental explanation for the paucity of calcitonin found in some adult thyroid glands. The close developmental relationship between the parathyroid gland and the ultimobranchial body could explain the presence of calcitonin found in these glands in some adults.

ISSN:1422-6405    

DOI:10.1159/000145130

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Electron microscopy revealed the presence of nonviral nuclear inclusions in human nontumorous as well as adenomatous adenohypophysiocytes, regardless of cell type. Based on ultrastructural appearances, the inclusions have been classified as simple bodies, complex bodies and filamentous aggregates. Many transitional forms were noted between the simple and complex bodies, however, no relationship between the nuclear bodies and filamentous aggregates was found. It can be concluded that the three types of inclusions are normal nuclear constituents. Since no accumulation of these structures was observed in cells associated with enhanced secretion it appears that they are not related to hormonal hyperactivity in the human adenohypophysis.

ISSN:1422-6405    

DOI:10.1159/000145131

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The electromyographic study of the subclavius muscle (SM) was performed in 31 different movements, in 12 subjects (10 male and 2 female) aged from 17 to 28 years. The action potentials were obtained with an electromyograph Teca TE 4. Our findings suggest that the SM acts mainly on the stability of the sternoclavicular joint; with more or less intensity according to the degree of the clavicular interaction with the movements of the peripheral parts of the superior limb. The SM seems to act as a substitute for the ligaments of the sternoclavicular joint.

ISSN:1422-6405    

DOI:10.1159/000145132

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

In mouse fetuses aged 12, 14, 16, 18 and 20 days, the cervical dorsal root ganglion was studied quantitatively. The main growth in volume of the interneuroblastic spaces was between the 12th and 16th day of pre-natal life while the main increase in volume of its neuroblasts occurred in the subsequent 4 days. Thus, it was postulated that the growth and branching of the neuroblastic dendrites, growth of the neuroglial elements and the vascular ramifications inside the ganglion occurred mainly between the 12th and 16th day of pre-natal life. Different modalities in the spatial relationship between the dorsal root ganglion and the different components of the spinal nerve were met with. At times, the trunk of the spinal nerve was located inside the ganglion. At that site, the posterior primary ramus emerged from it and appeared as a branch of the ganglion. The ventral root sometimes passed close to the fibrous capsule of the ganglion. In other cases, it passed inside the ganglion, dividing the ganglionic neuroblasts into dorsal and ventral groups. These either remained ensheathed by one fibrous capsule or became divided into two separate masses that remained connected to each other by the fibrous dural sheath.

ISSN:1422-6405    

DOI:10.1159/000145133

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Various doses of estriol (E3) were given to mice intraperitoneally, immediately after lethal irradiation and marrow reconstitution. The assessment of the plaque-forming cell (PFC) response to sheep erythrocytes in the spleen and the histological assessment of lymphoid tissues were carried out 30 days later. The effects appeared to be dose-dependent and resulted in a marked suppression of the PFC response. The depletion of lymphocytes was dramatic and dose-dependent in the thymus, and in the thymus-dependent and in the thymus-indepen-dent areas of the peripheral lymphoid tissues. These results suggest that E3 acts on the differentiation of stem or precursor cells toward both the populations of T and B lymphocytes. Although E3, given on day 7 after irradiation and marrow reconstitution, suppressed the lymphoid regeneration and PFC response markedly, E3 given on day 14 had no effect. On day 7 the majority of regenerating lymphoid tissues were large pyroninophilic cells and on day 14, small lymphocytes. These results suggest that the precursor or immature lymphocytes are sensitive to E3, while mature lymphocytes are resistant. Lymphoid regeneration and PFC response were retarded in mice irradiated and reconstituted with bone marrow cells from donors pretreated with E3. These results suggest that E3 acts on the stem or precursor cells capable to differentiate in the direction of lymphoid populations and reduce their number in the bone marrow.

ISSN:1422-6405    

DOI:10.1159/000145134

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Desmosomes entirely similar to those of the deeper layers of ruminal epithelium are seen in the luminal layers of the early fetal ruminal epithelium. In the older fetuses, these desmosomes have morphological features that reveal to some extent the occurrence of processes of keratinization. This could indicate that the basis for cell keratinization is already present in the fetus and that postnatal keratinization corresponds mainly to the full development or the prenatally existing pattern of differentiation.

ISSN:1422-6405    

DOI:10.1159/000145135

出版商:S. Karger AG    

年代:1979

数据来源: Karger