Subcellular Fractionation Studies of the Intestinal Mucosa in Congenital Sucrase—Isomaltase Deficiency

1979 ◽  
Vol 57 (2) ◽  
pp. 181-185 ◽  
Author(s):  
B. T. Cooper ◽  
D. C. A. Candy ◽  
J. T. Harries ◽  
T. J. Peters
Keyword(s):  
Electron Microscopy ◽  
Intestinal Mucosa ◽  
Brush Border ◽  
Enzyme Activities ◽  
Subcellular Fractionation ◽  
The Other ◽  
Marker Enzyme ◽  
Jejunal Biopsy ◽  
Biopsy Specimens ◽  
Highly Sensitive

1. Jejunal biopsy specimens from three children with congenital sucrase—isomaltase deficiency were assayed for disaccharidase activity and were subjected to analytical subcellular fractionation with enzymic microanalysis. 2. By use of the highly sensitive fluorigenic modification of the disaccharidase assay, brush-border sucrase and isomaltase activities were depressed but nevertheless detectable in each child. 3. Apart from the expected decrease in brush-border α-glucosidase activity, the other enterocyte marker-enzyme activities were normal. 4. There were no abnormalities in the enterocytes of any child on analytical subcellular fractionation or on electron microscopy.

Analytical Subcellular Fractionation of Jejunal Biopsy Specimens: Enzyme Activities, Organelle Pathology and Response to Gluten Withdrawal in Patients with Coeliac Disease

1978 ◽  
Vol 55 (3) ◽  
pp. 285-292 ◽  
Author(s):  
T. J. Peters ◽  
P. E. Jones ◽  
G. Wells
Keyword(s):  
Endoplasmic Reticulum ◽  
Coeliac Disease ◽  
Brush Border ◽  
Enzyme Activities ◽  
Subcellular Fractionation ◽  
Density Gradients ◽  
Marker Enzymes ◽  
Jejunal Biopsy ◽  
Essentially Normal ◽  
Biopsy Specimens

1. Portions of jejunal biopsy specimens from patients with coeliac disease were homogenized in isotonic sucrose solution and subjected to analytical subcellular fractionation by sucrose-density-gradient centrifugation. 2. The activities and distribution of marker enzymes for the principal subcellular organelles were determined by highly sensitive enzymic micro-assays employing fluorigenic and radiolabelled substrates. 3. In untreated coeliac disease the brush border showed decreased activities of five marker enzymes, which were reduced to up to one-eighth of control values. On sucrose density gradients the distinct brush-border peak at density 1.21 was replaced by a broad peak at density 1.16. 4. Two out of three lysosomal enzymes showed increased activities and there was evidence of enhanced fragility of both lysosomes and peroxisomes. 5. There were reduced activities of both mitochondrial and cytosol malate dehydrogenase, with increased activities of cytosol lactate dehydrogenase. 6. The endoplasmic reticulum and basal-lateral membranes were relatively unaffected except that the equilibrium densities were slightly increased and decreased respectively. 7. The patients were treated by gluten withdrawal and subsequent biopsies examined as above. Biopsies from patients treated for 2–4 weeks and who had not yet achieved a morphological improvement showed a partial return to normal of the pathological organelles. 8. Treated patients with partial villus atrophy showed progressively improved enzyme activities and a partial reappearance of the brush-border peak on the sucrose density gradients. 9. Patients whose intestinal mucosa had returned to morphological normality after prolonged gluten withdrawal showed a persistent defect in the brush-border enzyme activities. This was particularly striking for β-glucosidase, which was persistently deficient from the brush-border although approximately one-third of the total activity of this enzyme is normally found in this organelle. 10. The properties and enzyme activities of lysosomes, peroxisomes, endoplasmic reticulum, mitochondria and cytosol were essentially normal in the biopsies from fully treated patients.

Sequential Enzyme and Subcellular Fractionation Studies on Jejunal Biopsy Specimens from Patients with Post-Infective Tropical Malabsorption

1979 ◽  
Vol 56 (5) ◽  
pp. 479-486 ◽  
Author(s):  
T. J. Peters ◽  
P. E. Jones ◽  
G. Wells ◽  
G. G. Cook
Keyword(s):  
Brush Border ◽  
Giardia Lamblia ◽  
Gradient Centrifugation ◽  
Selective Reduction ◽  
Subcellular Fractionation ◽  
Equilibrium Density ◽  
Marker Enzyme ◽  
Jejunal Biopsy ◽  
Biopsy Specimens ◽  
Glutamyl Transferase

1. Jejunal biopsy specimens were obtained from seven patients with post-infective tropical malabsorption, four of whom were infected with Giardia lamblia. 2. Enzymic analysis of the biopsy homogenates revealed a selective reduction of certain enzymes (alkaline phosphatase, γ-glutamyl transferase) localized at least in part to the brush border. Other enzymes (leucyl-2-naphthylamidase, α-glucosidase) were unaffected. 3. Density gradient centrifugation confirmed the selective decrease in the brush-border activity but the equilibrium density of the organelle was normal. Homogenization studies revealed that the brush border was unusually fragile. 4. Apart from reduced activities of the basal—lateral marker enzyme 5′-nucleotidase and enhanced lysosomal fragility, other organelles showed normal properties. There were no significant differences in any of these parameters in the patients with or without giardiasis. 5. The patients were restudied after their jejunal morphology and clinical features had returned to normal. All these parameters, apart from a persistently reduced activity of 5′-nucleotidase, returned to normal. 6. It is suggested that the principal lesion in patients with post-infective tropical malabsorption affects the cell membrane, specifically affecting the absorptive—digestive capacity of the enterocyte. These findings suggest that there is direct brush-border damage rather than mucosal invasion by bacteria, viruses or Giardia lamblia.

Gilbert's Syndrome: Analytical Subcellular Fractionation of Liver Biopsy Specimens. Enzyme Activities, Organelle Pathology and Evidence for Subpopulations of the Syndrome

1979 ◽  
Vol 57 (6) ◽  
pp. 491-497 ◽  
Author(s):  
J. Dawson ◽  
C. A. Seymour ◽  
T. J. Peters
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Liver Biopsy ◽  
Enzyme Activities ◽  
Subcellular Fractionation ◽  
Equilibrium Density ◽  
Marker Enzyme ◽  
Gilbert’S Syndrome ◽  
Gilbert's Syndrome ◽  
Glutamyl Transferase

1. The hepatic organelle pathology of 12 patients with Gilbert's syndrome was studied by analytical subcellular fractionation in combination with enzymic microanalysis of liver biopsy material. 2. All patients showed increased activities of the endoplasmic reticulum marker enzyme, neutral α-glucosidase. Seven patients showed a decrease in the modal density of the endoplasmic reticulum, from 1·20 to 1·15 g/ml. These patients also showed striking hypertrophy of the hepatocyte smooth endoplasmic reticulum on electron microscopy. The remaining five patients showed normal endoplasmic reticulum density distribution with a peak at 1·20 g/ml, and had normal appearance of the endoplasmic reticulum on electron microscopy. 3. All patients showed increased activity of three lysosomal marker enzymes: N-acetyl-β-glucosaminidase, acid phosphatase and β-glucuronidase. The distribution of these enzymes in the sucrose gradients showed less enzyme in the high-density region of the gradients, indicating a reduced equilibrium density of the lysosomes. Assays of latent and sedimentable N-acetyl-β-glucosaminidase, a measure of lysosomal integrity, were normal. 4. Marker enzyme activities and density gradient distribution of other organelles, including plasma membrane (5′-nucleotidase), mitochondria (malate dehydrogenase), biliary canaliculi (γ-glutamyl transferase) and cytosol (lactate dehydrogenase) were normal. Increased catalase activities were noted.

Mucosal Peptide Hydrolase and Brush-Border Marker Enzyme Activities in Three Regions of the Small Intestine of Rats with Experimental Uraemia

1990 ◽  
Vol 79 (6) ◽  
pp. 663-668 ◽  
Author(s):  
D. J. Haines ◽  
C. H. J. Swan ◽  
J. R. B. Green ◽  
J. F. Woodley
Keyword(s):  
Enzyme Activity ◽  
Small Intestine ◽  
Intestinal Mucosa ◽  
Brush Border ◽  
Enzyme Activities ◽  
Small Intestinal Mucosa ◽  
Marker Enzyme ◽  
Small Intestinal Transit ◽  
Proximal Small Intestine ◽  
Small Intestinal

1. The activities of nine peptide hydrolases and three non-peptidase brush-border marker enzymes have been quantified in crude homogenates prepared from the proximal, mid and distal regions of small-intestinal mucosa for sham-operated (n = 9) and uraemic (n = 14) rats. Abnormalities in enzyme activities were observed in all regions studied in the uraemic group, although no reduction in food intake occurred. 2. The proximal region of the small intestine from uraemic rats showed a general fall in enzyme activities associated with the brush-border. This fall was combined with a decline in mucosal protein content. In contrast, the mid and distal regions showed increased activity against the dipeptide tyrosyl-glycine. 3. It is proposed that the fall in brush-border enzyme activities in the proximal small intestine of uraemic rats is a response to the increased water intake associated with this, and presumably other, rat models of uraemia. The increased enzyme activity against tyrosyl-glycine found in the mid and distal regions of the small intestine of uraemic rats may be caused by an increased small-intestinal transit rate, but could be an attempt to maximize tyrosine absorption in response to decreased plasma tyrosine levels. 4. This study casts doubt on specific activities being the most useful units of enzyme activity, when measured in crude homogenates prepared from the proximal small intestine of uraemic rats. It also demonstrates that enzyme activities measured at a single site in the small intestine of uraemic rats may not be representative of the enzymatic changes occurring in the small-intestinal mucosa as a whole.

Scanning Electron Microscopy of Human Jejunum in Whipple's Disease

1977 ◽  
Vol 35 ◽  
pp. 354-355
Author(s):  
John H. L. Watson ◽  
C. N. Sun
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Basement Membrane ◽  
Lamina Propria ◽  
Brush Border ◽  
Whipple’S Disease ◽  
Whipple's Disease ◽  
Biopsy Specimens ◽  
Brush Borders ◽  
Scanning Electron

That the etiology of Whipple's disease could be bacterial was first suggested from electron micrographs in 1960. Evidence for binary fission of the bacteria, their phagocytosis by histiocytes in the lamina propria, their occurrence between and within the cells of the epithelium and on the brush border of the lumen were reported later. Scanning electron microscopy has been applied by us in an attempt to confirm the earlier observations by the new technique and to describe the bacterium further. Both transmission and scanning electron microscopy have been used concurrently to study the same biopsy specimens, and transmission observations have been used to confirm those made by scanning.The locations of the brush borders, the columnar epithelial cells, the basement membrane and the lamina propria beneath it were each easily identified by scanning electron microscopy. The lamina propria was completely filled with the wiener-shaped bacteria, Fig. 1.

scholarly journals Use of electron microscopy in examination of faeces and rectal and jejunal biopsy specimens.

1991 ◽  
Vol 44 (4) ◽  
pp. 313-316 ◽  
Author(s):  
G M Connolly ◽  
D S Ellis ◽  
J E Williams ◽  
G Tovey ◽  
B G Gazzard
Keyword(s):  
Electron Microscopy ◽  
Jejunal Biopsy ◽  
Biopsy Specimens

Timed Sequential Ultrastructural Changes of Canine Kidneys Unflushed and After Flushing with Plasma

1971 ◽  
Vol 29 ◽  
pp. 314-315
Author(s):  
D. G. Osborne ◽  
M. O. Magnusson ◽  
W. S. Kiser ◽  
W. A. Hawk
Keyword(s):  
Electron Microscopy ◽  
Cold Plasma ◽  
The Other ◽  
Ultrastructural Changes ◽  
Biopsy Specimens ◽  
Ringer’S Lactate

Several methods and solutions have been used to preserve kidneys for transplantation. Among these are Collins C4; Ringer's Lactate and by perfusion by the (Belzer) LI-400 preservation system using plasma. In this experiment we hope to demonstrate ultrastructural changes of kidneys which were flushed with plasma, compared to kidneys which were unflushed.Eight dogs were used in our experiments. Each dog was anesthesized, the kidneys exposed, biopsied and then removed. Four dogs were sacrificed. One kidney from each dog was flushed with 150 ml of cold plasma, the other was left unflushed. They were then immersed in iced saline and kept at 0° to 4°C for the duration of the experiment. Biopsy times were 0, 1/2, 1, 2, 4, 8, 16 and 24 hours. The kidneys of the four remaining dogs were autografted at various intervals to compare ultrastructural changes with viability. All biopsy specimens were prepared for electron microscopy.

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