Morphological studies by light and electron microscopy of pancreatic acinar cells under the effect of Tityus serrulatus venom

1994 ◽  
Vol 278 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Maryann D. Fletcher ◽  
Lourival D. Possani ◽  
Paul L. Fletcher
1992 ◽  
Vol 73 (2) ◽  
pp. S10-S13 ◽  
Author(s):  
S. B. Doty ◽  
E. R. Morey-Holton ◽  
G. N. Durnova ◽  
A. S. Kaplansky

The Soviet biosatellite COSMOS 2044 carried adult rats on a spaceflight that lasted 13.8 days and was intended to repeat animal studies carried out on COSMOS 1887. Skeletal tissue and tendon from animals flown on COSMOS 2044 were studied by light and electron microscopy, histochemistry, and morphometric techniques. Studies were confined to the bone cells and vasculature from the weight-bearing tibias. Results indicated that vascular changes at the periosteal and subperiosteal region of the tibia were not apparent by light microscopy or histochemistry. However, electron microscopy indicated that vascular inclusions were present in bone samples from the flight animals. A unique combination of microscopy and histochemical techniques indicated that the endosteal osteoblasts from this same mid-diaphyseal region demonstrated a slight (but not statistically significant) reduction in bone cell activity. Electron-microscopic studies of the tendons from metatarsal bones showed a collagen fibril disorganization as a result of spaceflight. Thus changes described for COSMOS 1887 were present in COSMOS 2044, but the changes ascribed to spaceflight were not as evident.


1974 ◽  
Vol 11 (2) ◽  
pp. 165-171 ◽  
Author(s):  
F. W. Chandler ◽  
C. S. Callaway ◽  
S. R. Adams

A juvenile Rhesus monkey died suddenly while being conditioned for tissue culture studies. A diagnosis of necrotizing pancreatitis associated with adenovirus was made on the basis of the demonstration by electron microscopy of paracrystalline arrays of viral particles and granular and fibrillar inclusions in necrotic pancreatic acinar cells. This is the first description of necrotizing pancreatitis in a nonhuman primate. Adenovirus should be considered in the etiology of pancreatitis in nonhuman primates.


1984 ◽  
Vol 37 (3) ◽  
pp. 99 ◽  
Author(s):  
DL Obendorf

The bacterial population attached to the oesophageal lining in herbivorous macropods is described. This feature which occurs in both browsing and grazing macropodid species (Macropus, Seton ix, Thylogale and Wallabia) is demonstrated by light and electron microscopy. These studies have shown that the oesophagus may support a large and diverse population of bacterial forms, many of which have extracellular fibrous coats or homogeneous capsules. These coats and capsules appear to mediate the attachment of bacteria to the surface epithelium and to each other so that microcolonies or communities are formed. Such aggregations of bacteria are responsible for the greenish coloration of the oesophageal lining of these herbivorous species. Further examination of the bacterial association with oesophageal cells demonstrated that the bacteria did not invade the mucosa but merely colonized the superficial layer of cells. Cells with ruptured cell membranes were invaded by bacteria which appeared to digest the cytoplasmic contents. Sloughing of such cells provided a new surface for bacterial attachment and proliferation. The importance of this bacterial association is discussed in the light of the anatomical studies of the macropodid oesophagus and the known digestive processes of herbivorous macropods. It is proposed that this adaptation may have an important bearing on our knowledge of foregut fermentative digestion in macropods.


1969 ◽  
Vol 4 (1) ◽  
pp. 55-70
Author(s):  
R. L. TAPP

Watery vacuolation was induced in the acinar cells of the rat submandibular gland by allowing small pieces of tissue (2 mm3 to stand in suitable unoxygenated fluids at 20°C, and cells in various stages of vacuolation were examined by light and electron microscopy. No structural evidence for pinocytosis was found. Using basic solution (NaCl, 8.0 g/l.; CaCl2 0.2 g/l.; NaHCO3 1.0 g/l.) it was confirmed that vacuolation does not occur at 0°C, and that it is greatly reduced if Ca2+ is omitted. Vacuoles develop in pieces of tissue which have been separated from the animal for up to 2 h, provided that the pieces are then immersed in a suitable fluid. Vacuolation can occur in the absence of external Na+ or Cl-: cations substituted for Na+ allowed vacuolation in the order: Li+, full; Cs+, slight; K+ and Rb+, none. It can be prevented, however, if sufficient sucrose (> 210 m-osmoles) or glucose is added to the external fluid, but not by the same quantities of urea, glycerol, or propylene glycol. Metabolic poisons which block oxidative phosphorylation or glycolysis do not prevent vacuolation. It is concluded that vacuolation does not involve pinocytosis but represents the secondary segregation of fluid from an oedematous cytoplasm. The mechanism of secondary segregation and its possible relationship to secretion are discussed.


2000 ◽  
Vol 98 (2) ◽  
pp. 143-150 ◽  
Author(s):  
Aránzazu URUÑUELA ◽  
Manuel A. MANSO ◽  
Rosa M PINTO ◽  
Alberto ORFAO ◽  
Isabel DE DIOS

Trypsinogen and amylase content has been analysed by flow cytometry in individual pancreatic cells from rats with acute pancreatitis induced by pancreatic duct obstruction, from the earliest stages to 48 h after obstruction. Parallel morphological studies of the pancreas by electron microscopy and analysis of various parameters for the diagnosis of pancreatitis will allow research into the possible relationship between intracellular enzyme load and the severity of pancreatitis. Progressive increases in amylase activity in ascites and plasma, the volume of ascites, haematocrit, vacuolization, oedema and macrophage infiltration were observed between 1.5 h and 12 h after duct obstruction. A progressive increase in enzyme content was also observed in individual acinar cells at this stage. Interestingly, the larger increase was for trypsinogen, so that the trypsinogen/amylase ratio was significantly increased in all acinar cells by 12 h after duct obstruction. This represents a risk factor for the development of pancreatitis. Sections of pancreas taken from rats that had duct obstruction for 48 h showed massive dilatation and disorganization of the endoplasmic reticulum, focal apoptosis and necrosis. These severe alterations would affect enzyme synthesis, as reflected by the significant decrease in the intracellular enzyme load observed at this stage. However, not all acinar cells were affected equally by the damage induced by pancreatitis: R1 cells appeared to be more sensitive than R2 cells. In conclusion, intracellular accumulation of digestive enzymes occurs at early stages of pancreatitis, and this effect is proportionally greater for trypsinogen, a finding that could explain the degree of severity achieved in the course of pancreatitis.


Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).


Author(s):  
John H. L. Watson ◽  
John L. Swedo ◽  
M. Vrandecic

The ambient temperature and the nature of the storage fluids may well have significant effects upon the post-implantation behavior of venus autografts. A first step in the investigation of such effects is reported here. Experimental conditions have been set which approximate actual operating room procedures. Saphenous veins from dogs have been used as models in the experiments. After removal from the dogs the veins were kept for two hours under four different experimental conditions, viz at either 4°C or 23°C in either physiological saline or whole canine arterial blood. At the end of the two hours they were prepared for light and electron microscopy. Since no obvious changes or damage could be seen in the veins by light microscopy, even with the advantage of tissue specific stains, it was essential that the control of parameters for successful grafts be set by electron microscopy.


Author(s):  
Joseph M. Harb ◽  
James T. Casper ◽  
Vlcki Piaskowski

The application of tissue culture and the newer methodologies of direct cloning and colony formation of human tumor cells in soft agar hold promise as valuable modalities for a variety of diagnostic studies, which include morphological distinction between tumor types by electron microscopy (EM). We present here two cases in which cells in culture expressed distinct morphological features not apparent in the original biopsy specimen. Evaluation of the original biopsies by light and electron microscopy indicated both neoplasms to be undifferentiated sarcomas. Colonies of cells propagated in soft agar displayed features of rhabdomyoblasts in one case, and cultured cells of the second biopsy expressed features of Ewing's sarcoma.


Author(s):  
J.C.S. Kim ◽  
M.G. Jourden ◽  
E.S. Carlisle

Chronic exposure to nitrogen dioxide in rodents has shown that injury reaches a maximum after 24 hours, and a reparative adaptive phase follows (1). Damage occurring in the terminal bronchioles and proximal portions of the alveolar ducts in rats has been extensively studied by both light and electron microscopy (1).The present study was undertaken to compare the response of lung tissue to intermittent exposure to 10 ppm of nitrogen dioxide gas for 4 hours per week, while the hamsters were on a vitamin A deficient diet. Ultrastructural observations made from lung tissues obtained from non-gas exposed, hypovitaminosis A animals and gas exposed animals fed a regular commercially prepared diet have been compared to elucidate the specific effect of vitamin A on nitrogen dioxide gas exposure. The interaction occurring between vitamin A and nitrogen dioxide gas has not previously been investigated.


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