Sensory endings in the intramural ganglia of the stomach. Light optical and electron microscopic study

Puppies and young dogs at the age of 3 days up to 2 months were used in the investigation. In total stomach preparations neuronal structures were stained with methylene blue after A. S. Dogel. Routine electron microscopic studies were carried out. Within the structure of intramuscular vegetative plexus of the stomach a sensory plexus was demonstrated, its terminals forming receptive bushy structures in all the tissues. Especially numerous the sensory endings were in neuronal cords and ganglia. The sensory endings innervated all the elements in ganglia. Ultrastructure of receptor terminals situated in the intramural ganglia of the stomach corresponded to that of terminals in tissue mechanoreceptors described for skin, auriculum, carotid sinus and trachea. Peculiar multilayer lamillar structures formed by cytoplasmic axonal processes of lemmocytes around lance-shaped, arranged in rosary fashion receptor varicosities were described. Contact of receptor terminals with the neuronal cell body was demonstrated. Functional nature of the tissue receptors described was discussed.     

High-dose irradiation in the pig small intestine. Histoenzymology and electron microscopic study.

The early and late effects of a single high-dose irradiation (100 rad) in the pig small intestine have been studied by histoenzymology and electron microscopy and related to some functional data. 1) The initial atrophy induced by the irradiation appears late (on the 6th day), compared to other species. This is due to the fairly long regeneration time of the villi epithelium in the pig. 2) The initial lesions are similar to those observed in different experimental models (nuclear alterations, karyolytic bodies, etc.). They particularly involve the crypts, and are specially focused in the undifferentiated cells of GS phase or mitosis, but also in goblet and Paneth's cells. 3) The villi regeneration, over on the 23rd day, is preceeded by an active mitotic phase which first renews the undifferentiated cells. This mitotic activity, reaching its highest value on the 16th day, goes on during the whole regeneration period itself. 4) At the beginning, this regeneration is denoted by the high esterase activity of the crypt collar. It appears in many goblet cells and also in some absorptive cells which show, at once, some of the enzymatic activities of the striated border. However, for a short period, lipid absorption is quantitatively reduced. This is connected with the temporary cell immaturity (up to the 20th day) and to the poorly developed rough endoplasmic reticulum and Golgi apparatus. 5) Further on, the persistence of a malabsorption syndrome (lipids, calcium) is not connected, for the main point, with modifications of the morphology or the cytology of the villi (in spite of the abnormally high number of goblet cells and the presence of few pathologic absorptive cells). It is, in fact, related to the persistence of an inflammatory state of the lamina propria associated with an exudative enteropathy. The meaning of this last finding is not clear: it could depend on a primary infectious state due to the modifications of the endoluminal intestinal flora, or, rather, on a secondary infection supported by the trophic epithelial disturbances induced by a continuous vascular dyshoria due to the irradiation.     

Light and electron microscopic studies of the ventricular wall

Summary Electron microscopic data confirm the results gained with rapid Golgi preparations of adult rodent brains that tanycytes occur in clusters along the lateral wall of the third ventricle. The cytoplasmic matrix of these cells is considerably denser than that of typical ependymal cells. They have filaments and microtubules throughout their cytoplasm along with mitochondria and polysomes. At the surface is a compact group of microvilli which suggest that tanycytes might selectively absorb material from the ventricle.The tanycytes are segregated from neuropil by other tanycyte processes, by neighboring ependymal cells and by astrocytes. Yet there are gaps in this sheath. At these points tanycytes either abut upon or surround nonglial components of the neural fabric.Their cytological features and relations with the neuropil suggest that tanycytes selectively absorb material from the ventricle and release it along the basal process, primarily affecting those segments of neurons immediately adjacent to the tanycyte.Supported by: NINDS Grants 5 R01 NS 09001-02 NEUA, 5T01 NB 5309, and GM 00958, and by the Eleanor Roosevelt Cancer Foundation Research Institute.Acknowledgements: This work was initiated in the Anatomy Department of the Harvard Medical School with facilities provided by Prof. S. L. Palay (U.S. Public Health Service Grant No. NB 05591). Dr. R. B. Wuerker kindly and patiently provided the instruction and orientation to electron microscopy. The major portion of the study was completed in the Neurology Department of the University of Utah with the extremely competent, challenging assistance of Dee Lerdahl, Nina Belgarian, Keith Johnson and Lynn Kendricks.     

Spinous leafy nerve endings in the feline stomach wall.

The Champy-Maillet ZIO technique has been applied to the study of the muscular tunic of the stomach. In the corpus and antrum pyloricum some nerve fibres end in non-capsulated expansions owning thorn-like protrusions. Their morphology is studied and a possibly functional sensory significance is proposed, on the basis of previous experimental results.     

Light and electron microscopic studies of crayfish hemocytes

Using light and electron microscopy, three hemocyte types are described in the hemolymph of the crayfish. The coagulocyte comprises 65% of the total hemocyte number and contains medium-sized cytoplasmic granules, abundant dilated rough endoplasmic reticulum, and a highly developed Golgi complex. It rapidly undergoes cytolysis in vitro and participates in coagulation by releasing the contents of its granules to the hemolymph. The granulocyte comprises 31% of the total hemocyte number and is capable of phagocytosis. It contains large, irregularly shaped cytoplasmic granules, a moderately developed Golgi complex, and moderate amounts of non-dilated rough endoplasmic reticulum. During coagulation in vitro, the cell attaches and spreads onto the substratum; this is followed by a slow intracellular granule breakdown and cytolysis. The amebocyte comprises 4% of the total hemocyte number and it is also capable of phagocytosis. It possesses small cytoplasmic granules, many vacuoles, a moderately developed Golgi complex, and large amounts of smooth endoplasmic reticulum. It is distinguished from the other two cell types by being stable and motile in vitro.     

Morphometric and electron microscopic study of the small intestine following total orthotopical auto- and allotransplantation]

Total orthotopic autotransplantation of the small intestine was performed in 22 dogs, allotransplantation--in 13 dogs. Changes in the wall of the graft resulted from the effect of both nonspecific (ischaemia, blockage of lymph outflow, denervation) and specific factors connected with the reaction of tissue incompatibility. Changes caused by the nonspecific factors are demonstrated as lymphostasis, edema of the wall in the graft, atrophy of the villi with epithelial flattening, hyperplasy of the intestinal gland, macrophagal and plasmocytic reaction in the mucous lamina propria, drop in villous-cryptic coefficient and reduction of the absorbing surface of the villi. At autotransplantation, structural-functional changes in the intestine undergo three stages: the stage of acute morphological changes and pronounced functional disturbances (up to 1,5 months); the stage of relative structural stabilization and gradual functional restoration (up to 6 months); the stage of atrophic-hyperplastic changes in the wall and decrease in functional activity of the intestinal graft (followed-up for 15 months). At allotransplantation, depending on the degree of cellular reaction and vascular changes, as well as on the localization of the process in the wall of the graft, a "graft versus host" reaction and a "recipient versus graft" reaction is demonstrated. Peculiar rosettes of plasmocytes have been described as a possible index of the reaction "graft versus host".     

Light and electron microscopic studies on the medial forebrain bundle in the rat. ii. nerve terminals from the medial hypothalamus.

After the surgical interruption of connections between the medial and lateral hypothalamus of the rat axonal (transient) and nerve terminal degeneration was shown in the medial forebrain bundle (MFB) with light and electron microscopy. Following 1 mm long parasagittal cuts at various rostro-caudal levels the degeneration pattern within the MFB indicated a certain territoral arrangement of terminating fibres from the medial hypothalamus. After a parasagittal cut through the lateral retrochiasmatic area, degeneration was observed in the full length of the MFB. This suggests that a number of axons connect the medial and lateral hypothalamus through this area. With the aid of a parasagittal cut separating totally the medial and lateral hypothalamus, the degeneration of dendrites in the middle portion of the lateral hypothalamus was also revealed. These proved to derive from cells of the ventromedial nucleus.     

Light and electron microscopic studies on experimental nocardia-toxicosis in mice

An exotoxin (HS-6) produced by Nocardia otitidiscaviarum isolated from certain lesions of cutaneous nocardiosis of a male 82-year-old patient induced severe injuries in the pancreas, liver, stomach, small intestine, heart, thymus and kidney of male ICR mice. Mice given Nocardia-free preparation of HS-6 at a dose of 1 mg/kg of body weight developed several autophagic vacuoles in the pancreas and liver within 20 min after the i.p. injection. Thereafter, the autophagic vacuoles increased in number and size with time. About 24 hr after the administration of HS-6, the liver showed marked accumulation of fat droplets in the cytoplasm of the hepatocytes. Although they contained abundant autophagic vacuoles in the regions of RER, there were no lipomatoses in the acinar cells of the pancreas, those of the chief cells and smooth muscle cells of the stomach, Paneth cells, goblet cells, smooth muscle cells of the small intestine, and plasma cells in the digestive tract. Biochemical examinations revealed that HS-6 had no significant effect on the protein synthesis of reticulocytes. Inoculation of the Nocardia into the mouse peritoneal cavities caused marked granulomatoses in the pancreas, liver and regional lymph nodes, but did not develop autophagic vacuoles in RER regions of these organs.     

Light and electron microscopic studies of nucleus-like formations of fragmented oocytes in rat ovary]

Oocytes in ovarian atretic follicles now and then show in their cytoplasm nucleuslike formations. The appearance of those pseudonuclei in the rat is described by light-and electron microscopy. Every pseudonucleus contains one or more Feulgen positive particles, and is surrounded by a membrane on its surface. The pseudonuclei are formed in the course of degeration of the oocyte during 1. und 2. meiotic metaphase from contracted chromosomes, probably with the involvement of the mixoplasma.     

Eosinophilic globule cells in mouse MFH-like sarcomas. Light and electron microscopic studies

Light and electron microscopic observations were made on eosinophilic globule (EG) cells found in 27 subcutaneous malignant fibrous histiocytoma (MFH)-like sarcomas in aged ICR mice. These tumors, which were composed of fibroblast-like cells as the major component, with small numbers of histiocyte-like cells and undifferentiated cells, showed one or more of five growth patterns: storiform, pleomorphic, fascicular, myxoid, and hemangiopericytoma-like. EG cells were interspersed among the tumor cells and were also present in metastatic lesions. They were pleomorphic in shape and contained various numbers of cytoplasmic globules, which were positive with the periodic acid-Schiff reaction and resistant to diastase digestion. Electron microscopic observation revealed that these cells had small finger-like and pseudopodia-like projections, and contained varied numbers of characteristic osmiophilic globules and glycogen particles in the cytoplasm which seemed to become more abundant as the cells differentiated. The osmiophilic globules consisted of a dense homogeneous core and a marginal area rich in small vesicular membranous structures. A small population of EG cells exhibited features suggesting differentiation to fibroblasts; these were characterized by an increased amount of rough endoplasmic reticulum. It is suggested that the EG cell is a neoplastic cell, perhaps derived from a primitive mesenchymal cell, although an inflammatory cell origin is also possible.     

Character of Auerbach's plexus receptors in the stomach and small intestine]

The motility of the stomach and jejunum in 8 fed dogs with the intact vagus nerves was registered by the balloon method. Subcutaneous injection of benzohexonium (0.125--0.5 ml of 2.5% soltuion) and atropine (0.12--0.25 ml of 0.1% solution) or metacine (0.125--0.25 ml of 0.1% solution) to 6 dogs proved to induce a transition from digestive motility to the periodic form after a transient depression of the digestive motility. The same effect followed injection of 0.5--1.0 ml of 0.1% atropine only in 2 dogs and 1.0 ml of 0.1% metacine in 1 dog. Since retention of periodic motility following food consumption was inherent for vagotomized dogs, a conclusion was drawn that the experimental dog had "pharmacologic vagotomy". It was suggested that the muscarine receptors on the Auerbach's plexus cells exceeded the nicotine receptor in number.     

Light, fluorescence and electron microscopic studies of rabbit subclavian glomera.

The subclavian glomera (aortic bodies) of young New Zealand white rabbits were studied with the light, fluorescence, and electron microscopes. Two cell types were identified: type I, granule-containing (chief) cells, and type II, agranular (sustentacular) cells. The type I cells possessed large nuclei, the normal complement of cytoplasmic organelles and numerous electron-opaque cytoplasmic granules. The type II cells were agranular with attenuated cytoplasmic processes which partially or completely ensheathed the type I cells. The glomera were well vascularized. Capillary endothelial cells contained numerous pinocytotic vesicles, but few fenestrae. Two profiles of nerve terminals were observed. One, apposing the type I cells, contained numerous electron-lucent vesicles, several dense-cored vesicles, mitochondria and possessed membrane specializations resembling those usually observed in synaptic zones. The other profile contained abundant mitochondria and a few electron-lucent and dense-cored vesicles. Structural specializations were not observed on the apposed membranes of these terminals or adjacent to type II cells. Fluorescence histochemistry revealed an intense yellow-green fluorescence in the glomera, which indicated the presence of biogenic amines, possibly primary catecholamines or an indolamine. The electron-opaque granules observed in the type I cells were believed to be the storage sites for these amines. The subclavian glomera were found to be morphologically similar to the carotid body which is a known chemoreceptor.