摘要:

The electron microscopic study of the neuronal structures of the pallidum externum (Pa.e) and internum (Pa.i) in squirrel monkey (Saimiri sciureus) has revealed in both segments a frequent large type of nerve cell and a rare small one, probably an interneuron. With respect to the small cells, only one axosomatic synapse inserts on the slender rim of cytoplasm; the clear nucleus is always invaginated and contains a small nucleolus. Eight types of synapses can be differentiated in Pa.e and Pa.i. The axodendritic type I P with pleomorphic vesicles and an inconspicuous symmetric contact to a central dendrite, make up 65% of all synapses in Pa.e and 79% in Pa.i. These synapses are commonly arranged in a rosette pattern around the dendrite. Two subtypes of the type I P are found in both segments – the one with invaginated boutons (subtype I Piv) and the other (subtype I Pol) oligovesicular. The type III SR synapses are characterized by small round or slightly oval vesicles and a strongly asymmetric contact (12% in Pa.e and 8.1% in Pa.i). The predominantly axosomatic type II EF synapses are characterized by elongated vesicles as well as by encapsulation in thin astrocytic processes (5% in Pa.e, 8.5% in Pa.i). The boutons of type IV Sph characterized by large uniformly spherical vesicles undergo symmetric synaptic contacts (in Pa.e 6% and in Pa.i 0.5%). The type V Osl stiletto-shaped bouton with ovoid vesicles undergoes a symmetric contact with a dendrite (in Pa.e 5% and in Pa.i 1.1%). Two types of dendrodendritic and dendrosomatic synapses are found: the type VI DE containing sparsely distributed elongated vesicles suspended on neurofilaments, undergoing a symmetric contact, and the type VII DC with clustering mostly round vesicles near the presynaptic component of the asymmetric contact. The rare axodendritic type VIII My arising from a myelinated axon, exhibits small elongated vesicles and symmetric contact. The synaptic types I, III, IV, and VI are similar to the same types in the substantia nigra, whereas types II, V and VII resemble the equivalent types in the motor thalamic VA and ventro-oralis anterior nucle

ISSN:1422-6405    

DOI:10.1159/000145824

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

A hypothesis for contraction was suggested (molecular basis of the transmission of ciliary coordination) by means of the slipping and interdigitation of the microfilaments of one period with those of the adjacent periods, occurring at the level of the periodic band. The amplitude of the period is greater in the relaxed than in the contracted state, while the reverse is true with the periodic band amplitude. The microfilament length is constant, probably varying with the species. This hypothesis of the slipping and interdigitation of the microfilaments would be the basis of the ciliary coordination from cilium to cilium and from cell to cell, because of the anchoring of the bunches in the peribasal complexes and in the adherent connection complexes, respectively.

ISSN:1422-6405    

DOI:10.1159/000145825

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The autolytic ultrastructural changes of the human myocardium were studied in 25 specimens taken 30 min to 18 h post mortem. Damage to the mitochondrial membranes and the appearance of mitochondrial armorphous densities characterized the irreversible lesions of the autolytic myocardium. The development of these changes was observed in consecutive samples. At 30 min, few small densities were noticed inconsistently, and they progressively increased in size and number over the next 90 min. The development of these changes was unrelated to the cause of death. Comparison of the ischaemic heart lesions of animals with those of humans shows a similarity of the mitochondrial amorphous densities. The best analogy was found to exist between the autolytic changes of the human myocardium and the irreversible ischaemic heart lesions of dogs.

ISSN:1422-6405    

DOI:10.1159/000145826

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The three-dimensional development of the separated parts of the porcine placenta from 9 Danish Landrace sows at gestational stages from 20 to 100 days was studied. After cautious separation of the allantochorion and the endometrium in a 1 mM buffered ethylenediaminetetraacetic acid solution, the separated parts were processed for scanning electron microscopy by routine methods. The macroscopic enlargement resulted from primary and secondary circular folds or plicae, which were permanent on the maternal side, whereas they were mainly non-permanent on the fetal side. The areolar placenta and interareolar placenta with formation of permanent microscopic folding on both sides were described. The observations of the separated parts yielded new information on the development of surface enlargement during gestation and revealed a hitherto unknown regular architecture of the endometrium by the formation of parallel primary ridges or rugae with secondary ridges or rugae at their sides subdividing the maternal troughs or fossae. This configuration on the maternal side explains the transformation of the regular chorionic ridges from the 63-day stage into bulbous protrusions at the 100-day stage. Based on these observations the precise terminology used above was proposed.

ISSN:1422-6405    

DOI:10.1159/000145827

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

A human astrocytoma has been studied with the freeze-fracture technique. The astrocytic membrane presents many assemblies formed by aggregations of intramembranous particles (5.8–7.8 nm in diameter) in P-face arranged in a square, and complementary pit assemblies in E-face. In the interastrocytic gap junctions the connexions are packed in a crystalline arra

ISSN:1422-6405    

DOI:10.1159/000145828

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Mitoses, direct division or cell fusion are observed during symplasm formation in the rabbit uterus epithelium. These phenomenon are examined through transmission electron-microscopic studies. Two types of direct division are described: (1) nuclear scission after folding of the membrane and (2) nuclear scission by invagination of the membrane. The existence of amitoses has long been contested in mammals; the present study tends to show that direct division is not an accidental karyorrhexis but is organized at the cellular level.

ISSN:1422-6405    

DOI:10.1159/000145829

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Experimental liver injury was induced to test rats with a daily injection of thioacetamide (ThAA). The doses used for intraperitoneal administrations were 50 mg/kg body weight. The loss of body weight in the 3-week test period was 15%. In the liver there was seen progressive changes which displayed cell necrosis and regeneration. The influence of ThAA on rat blood and serum was checked using standard biochemical assays consisting of the percentage of blood obtainable and the serum/blood ratio and analysis of serum alanine transferase, serum alkaline phosphatase, serum creatinine, and hydroxyproline in the acute, subacute, chronic, and necrotic stage of liver injury. With ThAA injections, the stimulated rate of glycosaminoglycan synthesis had its association to the serum calcium content. It decreased continuously as function of traumatization time. In the 3-week test period, histological findings show in the alveolar bone, around the teeth, when under occlusal stress and ThAA traumatization, the distinct decrease in osteoblastic activity and less osteoids indicating thus the decreased formation of new bone. Conspicuous osteoclastic resorption was also seen in the same area.

ISSN:1422-6405    

DOI:10.1159/000145830

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

In children, the maxillary sinus is pyramidal in shape. The apex of the pyramid looks forward, and the base looks backwards. The maxillary sinus has three walls – the superior, the medial and the inferior. The superior wall establishes a relationship with the infraorbital groove and the infraorbital canal during the 4th year. During the first months of life, the maxillary sinus has no relationships with the inferior nasal meatus. At about 6th year, the maxillary sinus is at the height of the floor of the nasal cavity and thus a close relationship is established with the inferior nasal meatu

ISSN:1422-6405    

DOI:10.1159/000145831

出版商:S. Karger AG    

年代:1984

数据来源: Karger