Functional and developmental morphology最新文献

An unusual case of spike antlers in male red deer is described in which the antler core apparently survived the partial mineralization of the cortex in the first rut and then in the next year supported a new, "antleroma-like" growth. On one side of the antler beam a "separation gap" developed between the living core and the dead cortex. On the opposite side a new growth of antler tissue was observed; this was made of spongious bone which in some areas partially resembled peruke-like growth and in others resembled antler "pearls". This new tissue, which developed probably in the second antler cycle, grew in the right antler from the base to the apex but in the left antler it was limited to the lower portion of the beam. This new tissue might still have been covered with velvet when the deer was shot. It is speculated that hypoandrogenism or partial lack of testosterone receptors was responsible for the survival of the antler core and the subsequent proliferation of new antler tissue in the following year.

Different cytochemical techniques at the electron microscopic level were used to investigate the presence of basic and acidic proteins during spermiogenesis in mice. Basic lysine rich proteins were demonstrated with an ethanolic solution of phosphotungstic acid, acidic agryrophilic proteins using two silver staining procedures applied en bloc and on the ultrathin lowicryl sections. Both types of proteins had very similar localization in the nucleoplasm and identical distribution within the postacrosomal dense lamina on the surface of late spermatid heads. The specificity of reactions is briefly discussed.

The ontogenetic development of the vascular bed was studied in the muscles of human fetuses after India ink and gelatine injections. By the 12th week of intrauterine life the architectural arrangement of the largest (primary) intra-muscular vessels is qualitatively comparable with that of the adult muscles. The smaller (secondary) vessels, as well as the microcirculatory bed, have very immature features in all fetal muscles studied. This part of the vascular bed develops gradually during further time from a primitive intramuscular capillary network. The basic architectural arrangement of the microcirculatory bed in adult muscles, and the development of the structure of the hilar vessels of the gastrocnemius muscle were described in the muscles of fetuses, newborns, and adults.

Lung damage caused by inhalation (single exposure for 60 min) of sublethal concentration of pure aerosols of dibenz(b,f)-1,4-oxazepine (CR) and 1-chloroacetophenone (CN) have been examined at different time intervals in rats. The damage was not severe with CR (2830 mg.m-3) but in the case of CN (60.26 mg.m-3) it was evident up to 30th day post exposure. Necrobiosis, attenuation of bronchiolar epithelium, edema in the air ways and also in the lumen of alveoli leading to substantial changes in the histoarchitecture of the lung were observed during CN exposure. On the other hand CR caused degenerative changes which disappeared on 30th day.

The pre-central, central and post-central arteries of 29 human brains were studied after the injection of Batson's resin. The purpose was to establish their position in relation to the central sulcus and nearby sulci and convolutions. With the Batson resin injection was observed that the pre-central, central and post-central arteries were coincident with the sulci in more than 75% of the cases and the central and post-central arteries when coincident to their sulci were deep inside in 75% of the hemispheres.

We have studied development of vertebral bodies with special regard to the area of contact of the vertebral body with the intervertebral disc. We have investigated complete serial sections of fetuses of the 2nd to 3rd month of intrauterine life, microscopic preparations from children, adolescents and young adults. The results of our studies and deductions from our findings are as follows: 1. Cartilaginous plates on contact surfaces of vertebral bodies with intervertebral discs are genetically parts of vertebral bodies, not of the discs. 2. During ontogenesis and growth period of life typical growth (epiphyseal) cartilages with all layers described on growth cartilages of long bones are formed on the surface of these cartilaginous plates facing the vertebral bodies. 3. From the point of view of its growth, the vertebral body should be considered to be a long bone. 4. Unlike other long bones of the skeleton, vertebral body epiphyses never ossify, and after the end of the growth period of life they are reduced into thin plates of hyaline cartilage which are situated between vertebral body and intervertebral disc. 5. We assume nucleus pulposus is not a persistent residuum of notochord. 6. According to our findings the link of sacral vertebral segments is from the very beginning of development typical synchondrosis with bipolar physes without formation of primordium of intervertebral disc.

This study describes the degenerating axonal termination and filamentous synaptic degeneration after 30 minutes spinal cord ischemia followed by 3 days survival using Hicks neurofibrillar impregnation. From laminoarchitectonic point of view a clear evidence was gained supporting the original description obtained by Nauta method. The majority of degenerated boutons revealed by Hicks method was found in the deep layers of the dorsal horn and then with increasing density in the intermediate zone and partly in the neuropil of the anterior horn. These results confirm the ability of Hicks method as a reliable tool in systematic research of the ischemically damaged synaptic contacts.

Observations in a wide selection of lower vertebrate embryos have confirmed classical descriptions concerning segmentation of the early head mesoderm. The premandibular (PM) segment is seen as the most rostral representative of a continuous rostro-caudal series of condensations in the paraxial mesoderm, luminisations within which are secondary and variable in occurrence and form. The premandibular condensations are typically in continuity across the midline; the confluence, which comes to lie behind Rathke's pouch, marks the site of first mesoderm formation behind the oral membrane. The underlying consistency of pre-otic segmental pattern throughout the vertebrates is frequently obscured by superimposed variation in morphological detail between species, reflecting the dynamic nature of the morphogenetic tissue processes. Luminisation is one such morphogenetic epiphenomenon. Variations in it account for the terminal (Platt's) vesicle and "proboscis pores": such structures cannot therefore be safely used to infer evolutionary homologies. Many previous difficulties facing segmentation theory are explained as the result of failure to take account of the dynamic nature of the responsible morphogenetic events.

The ultrastructure of human diaphragmatic, thoracic wall and visceral pleura was studied by scanning and transmission electron microscope. Human pleural stomata, which are usually round or oval in shape with about 6.2 microns in diameter, were present on the diaphragmatic pleura. They were never found on the thoracic or visceral wall. Majority of human pleural stomata were quite deep, forming channels which seemed to connect pleural cavity with underlying lymphatic lacunae. Some of them occurred as shallow pits exposing components of the underlying connective tissue. In some areas of the diaphragmatic pleura the pleural stomata were furnished with great microvilli of mesothelial cells surrounding their openings. These microvilli were always longer and had denser network of filaments in comparison with other on the surface of mesothelial cell. In this way the mesothelial cells formed valve-like cytoplasmic processes into the channels. The results of the present study suggested that the pleural stomata, as permanent structures, provided a rapid removal of fluid, particles and cells from the pleural cavity into the diaphragmatic lymphatics.