Anatomical Record最新文献

Calmodulin distribution in the chicken pineal organ was investigated by immunohistochemistry. Calmodulin immunoreactivity was detected in ependymocytes in the follicular zone and in interstitial cells in the parafollicular zone. No calmodulin immunoreactivity was detected in pinealocytes. Lack of calmodulin immunoreactivity in pinealocytes raises questions about its proposed function in melatonin synthesis as suggested by pharmacological studies using calmodulin antagonists. The calmodulin distribution was comparable to that of S100, a glial cell marker. Two other markers, calbindin-D28k and calretinin, which in neuroanatomical studies give excellent cytoarchitectonic staining, in the chick pineal permitted the detection of two subclasses of pinealocytes. One was darkly stained by calbindin-D28k and rare. The other was very abundant and calretinin positive. In the parafollicular zone, calbindin-D28k and/or calretinin antibodies allowed us to visualize cells presenting a neuron-like morphology. Calretinin immunoreactivity was detected in nearly all pinealocytes in which hydroxy-indol-O-methyl transferase was also located. Comparison between the lack of calmodulin and the presence of calretinin, belonging to the same calcium-binding protein family, in chick pinealocytes raises the hypothesis about a possible role of calretinin in melatonin synthesis.

High field proton magnetic resonance (MR) imaging has been applied to depict the MR appearance of the normal excised human cervicomedullary junction, based on which neuropathologic specimens can be described. More specifically, two normal cases and one case of Chiari deformity were imaged in the transverse, sagittal, and coronal dimensions using a 9.4 Tesla vertical bore magnet. The MR images of the normal specimens reveal most of the neuroanatomical microstructures described in literature. An accurate description of the Chiari deformity could be made by comparing the MR reference images with those of the pathologic specimen. All MR detected abnormalities were confirmed by histopathology, by which no additional lesions could be found.

Postnatal development and differentiation of the rat epididymis was studied in the rat from 15 to 120 days of life using stereological techniques. Both the relative volume (volume density) and absolute volume of the epithelial, interstitial, and luminal compartments in the initial segment, caput, corpus, and cauda epididymides were determined. In all segments the volume density of the epithelial compartment increased between days 15 and 30 before falling to adult values at 45 days in the initial segment (0.476 +/- 0.031), at 60 days in the caput (0.258 +/- 0.028) and at 90 days in the corpus (0.245 +/- 0.007) and cauda (0.140 +/- 0.004). The relative volume of the interstitium decreased, whilst that of the lumen increased over the same period with adult values being achieved earlier in the proximal segments than in the distal segments. In contrast to volume fraction the absolute volume of all compartments in all segments increased from day 15 to day 90. Between 90 and 120 days the absolute volumes of compartments in the initial segment and caput showed little volume change. All compartments in the corpus and cauda showed significant increases in volume over the same period. A similar pattern of development was observed with respect to the surface area of both the luminal and basement membrane aspects of the epithelium; surface area per unit volume (surface density) in all segments reached adult values at approximately 60 days, whilst the increase in absolute area of the surfaces ceased at 90 days in the initial segment and caput and continued to 120 days in the corpus and cauda.(ABSTRACT TRUNCATED AT 250 WORDS)

The vascular interrelationship of the well-established porcine placenta has previously been described from vascular casts and histology, but not its developmental stages. This study was performed using the same methods on 17 sows of well-known stages of gestation ranging from 9 1/2 to 43 days post coitum (p.c.). At the precontact stage, days 9 1/2 to 12 1/2 p.c., the subepithelial capillaries formed a wide open meshwork of variable diameter, 3-14 microns, without any difference between meso- and antimesometrial side. At the early contact and adhesion stages (days 13 to 18 p.c.), the first increase in vasculature was seen at the mesometrial side close to the embryonic disc of the very long blastocyst at day 15 p.c., 2 days after the first contact between trophoblast and maternal epithelium was seen. At day 18 p.c., the areas with dense capillaries increased markedly at the mesometrial side with the same parallel organization as seen at day 15 p.c., whereas the antimesometrial side still had a relative loose appearance comparable to the previous stages. At the early placental stages (days 20 1/2 to 23 p.c.), the capillary bed formed smooth folds, which in some areas at day 20 1/2 days developed into smaller folds or prerugae. Here the capillaries changed to convoluted forms with slightly bulbous dilations measuring about 30-35 microns in diameter. This developmental progress became more elaborate at day 23: capillaries of the low ridges of prerugae formed irregular dilations up to 50 microns in some areas. At this stage the parallel arrangement of the capillary meshwork characteristic of the previous stage was not longer discernable. By days 32-43 p.c., an increase in microscopic folding was present, and the maternal arterioles could be traced to the top of the ridges, creating the characteristic vascular architecture needed for an efficient exchange of oxygen, carbon dioxide, and nutrients of the basically developed porcine placenta.

Studies on the endometrial cycle depend upon the precise dating of the cycle stage. In the present paper the generally applied method of vaginal smear was carefully verified through the measurement of the hormones relevant to the endometrial cycle. From rats predated through vaginal smear cytology, the hormone levels of estradiol-17-beta (E2) and progesterone (P), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were measured. The values obtained were then compared to the standardized values of our reference curve. Animals with values that did not fit within the standard deviation of our reference curve were excluded from this investigation. Thus, for the first time exactly dated rat endometrial morphology was studied with electron microscopy. The morphology of the surface epithelium of rat endometrium from all four stages of the cycle is described in detail. In addition a semiquantitative morphometric analysis of the following parameters was performed: cell volume, nuclear volume, the volume density of secretory granules, digestive vacuoles, mitochondria, Golgi apparatus, rough endoplasmic reticulum, and lipid vacuoles as well as the size of lipid vacuoles. With the cellular content of lipid vacuoles and their diameter, it is possible to differentiate between proestrus/estrus and diestrus I/diestrus II, the latter possessing definitely more and larger lipid vacuoles. During estrus the greatest cytoplasmic volume develops. In addition to this, secretory granules are only present during estrus. Finally, diestrus I can be well differentiated from diestrus II, because diestrus I exhibits more digestive vacuoles and during diestrus II a high percentage of free ribosomes is present. On the basis of distinct morphological features, described in this paper, it is now clearly possible to distinguish between the four different cycle stages.

The purpose of this investigation was to test the hypothesis that activation of the immune system in rats will lead to changes in the density of innervation in lymph nodes. In order to reduce the variability between animals, the rats were reared under sterile conditions and immunostimulation was effected by subcutaneous application of bovine albumin in a region draining to the axillary lymph nodes of both sides. Control animals received an equivalent application of sterile physiological saline. The animals were sacrificed 10 days and 27 days and 4 months after immunostimulation. The nerves in the axillary lymph nodes were quantified by light microscopy in silver impregnated sections and at the ultrastructural level on ultrathin sections. The survival times were chosen so that the first group was in the ascending phase of antibody production, the second group at the peak, and the third group in the declining phase. Both at the light and ultrastructural levels, there were statistically significant differences in the density of innervation of medulla between the groups, with a particularly pronounced increase in the group 4 months after immunostimulation. At the ultrastructural level, there was also an increase in the density of incompletely ensheathed axonal profiles in the parenchyma of the medulla, while the nerves associated with blood vessels were not increased. We conclude that immunostimulation leads to morphological changes in the innervation of the medulla of axillary lymph nodes, that are consistent with the concept of functional activation of the autonomic nervous system through the immune system.

The facial nerve was unilaterally crushed at its exit from the stylomastoid foramen in three 3-month old male rats. After 10 days survival, before the regenerating axons had reinnervated their target muscles, the facial nucleus was examined to determine central patterns of response in material prepared to demonstrate the presence of GABA-like immunoreactivity with postembedding procedures using gold-labeled secondary antibody. The uninjured nucleus served as a control. In both control and injured nuclei, the GABAergic terminals synapse with all parts of the motor neurons, except the axon, and exhibit diverse morphologies. GABAergic axon terminals vary in their size and in the electron density of their axoplasm and the majority of the terminals contain pleomorphic vesicle profiles that display a range in their packing density and size. In both control and injured facial nuclei, only approximately 40% of the axon terminal profiles with pleomorphic vesicles exhibit GABA immunoreactivity. A morphometric analysis of the synaptic vesicle profiles in the GABA-positive terminals reveals that following axotomy there is no change in the mean number of synaptic vesicle profiles per GABAergic terminal profile. However, the mean size of the synaptic vesicle profiles in these terminals shows an axotomy-induced 50% increase, without change in the shapes of the enlarged vesicle profiles. Also, the numerical density of gold particles associated with the GABA-positive terminals is consistently greater in the injured than the control axon terminals. In the control animals quantitative analysis of the relative distribution of all axon terminal profiles in the neuropil categorized by the shape of their vesicle profiles as round, pleomorphic, or flat is 57:37:6. Ten days after axotomy the ratio of these categories in the injured nucleus has shifted to 35:60:5. This study demonstrates that the functional state of a postsynaptic target can influence the morphology of vesicle profiles in presynaptic elements as well as patterns of its afferent input.

Normal human dermis has been analyzed using stereological methods to estimate the quantitative modifications of collagen and elastic fibers in relation to age, sex, and body region. Forty-five skin biopsies from the trunk or the limbs of 26 males and 19 females of different age were fixed in glutaraldehyde and osmium tetroxide and embedded in epoxy resin. The relative volumes of collagen and elastic fibers were calculated by the point counting method on 1 micron semithin sections. Photographic sampling was performed on four consecutive dermis layers: the papillary layer and three consecutive layers of reticular dermis. The data were subjected to analysis of variance which showed that all the factors studied exert a significant influence on the relative amounts of collagen and elastic fibers. The fractional volume of collagen fibers is constant throughout all dermis layers analyzed and is always higher in females than in males, except for the second and third decades of life. Collagen fiber density increases with age in both sexes up to 30-40 years, when it starts decreasing. Both the relative volumes and the diameters of elastic fibers increase from papillary to deep reticular dermis. In reticular dermis of both sexes there is an increment of elastic fiber density in the first decade of life, followed by a drop particularly marked in males. After 20 years, the relative volume of elastic fibers displays a decreasing trend in females, whereas it increases in males, attaining the highest values beyond the 40s.

Esophageal atresia and tracheoesophageal fistula, common malformations of the respiratory and digestive tracts, are of unsettled pathogenesis. Part of the difficulty in understanding these abnormalities arises from the uncertainties about the normal developmental processes in the region. This study examined the development and fate of the tracheoesophageal septum. Normal human embryos from the Carnegie Embryological Collection and fetuses from the Hopkins Pathology Collection were examined, and reconstructions of selected specimens were made from photomicrographs of serial histologic sections. The results show that the lung bud appears in Carnegie stage 12, rapidly enlarges, and bends caudally, thereby producing a sulcus between the foregut and the respiratory system on its caudal aspect. The cranial aspect of this tracheoesophageal sulcus remains fixed at the levels of the first cervical vertebra throughout subsequent embryonic and fetal development. At the same time the trachea and esophagus elongate to bring those part of the respiratory and digestive systems into their definitive anatomic positions. Examination of the tracheoesophageal sulcus shows that its growth-limiting properties may be explained by its catenoidal configuration. Catenoidal, or saddle-shape, sulci have been shown to have similar regional growth-limiting properties in the embryonic heart. These regions contrast with outwardly convex regions in both the developing heart and lung where growth of the tissues occurs. The observations made here suggest that the origin of the tracheoesophageal malformations must be sought in a configurational abnormality in the area of the developing lung bud in Carnegie stage 12.

The anatomy of the hyo-lingual apparatus in the iguanid lizard Oplurus cuvieri has been studied by light microscopy and scanning electron microscopy. Four areas were observed on the dorsal lingual epithelium of the lizard. Tongue tips are covered with a smooth epithelium. Closely packed flattened and cylindriform papillae cover the foretongue. The surface of the midtongue bears an unpapillose epithelium. Short conical papillae are arranged on the two lateral posterior bundles of the tongue. At high magnification, microvilli and microridges are widely distributed over the surface of the papillae. The epithelium of the papillae is composed of cells filled with secretory granules. Each surface plays successive roles during food ingestion, intra-buccal transport, and swallowing. The mucous interpapillary spaces would serve the adherence between the tongue and the food, the smooth epithelium of the midtongue should facilitate movements of the prey toward the pharynx, and conical papillae of the hindtongue present a rough surface which should act on the prey during the swallowing phase. The intrinsic morphology of the tongue is rather similar to that previously described for iguanids, but fibers of M. verticalis encircles ventrally the lingual process. These fibers could act in tongue protrusion as previously suggested for agamids. The morphology and function of the extrinsic tongue musculature and the hyoid musculature, analysed by electrical stimulations, are similar to the previous descriptions in iguanids and agamids either for feeding or displaying functions.