?In situ? determinations of apparent K m and V max of brush border disaccharidases along the villi of normal human jejunal biopsy specimens

1981 ◽  
Vol 71 (3) ◽  
pp. 451-462 ◽  
Author(s):  
S. Gutschmidt
1979 ◽  
Vol 57 (2) ◽  
pp. 181-185 ◽  
Author(s):  
B. T. Cooper ◽  
D. C. A. Candy ◽  
J. T. Harries ◽  
T. J. Peters

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.


1978 ◽  
Vol 55 (3) ◽  
pp. 285-292 ◽  
Author(s):  
T. J. Peters ◽  
P. E. Jones ◽  
G. Wells

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.


1979 ◽  
Vol 56 (5) ◽  
pp. 479-486 ◽  
Author(s):  
T. J. Peters ◽  
P. E. Jones ◽  
G. Wells ◽  
G. G. Cook

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.


Author(s):  
John H. L. Watson ◽  
C. N. Sun

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.


Gut ◽  
1998 ◽  
Vol 42 (1) ◽  
pp. 135-138 ◽  
Author(s):  
M P Buisine ◽  
J F Colombel ◽  
M Lecomte-Houcke ◽  
P Gower ◽  
J P Aubert ◽  
...  

Background—Cap polyposis is a rare disease characterised by mucoid and bloody diarrhoea, with polyps covered by a cap of mucoid and fibrinopurulent exudate. The pathogenesis is not known.Aims—To pour some light on cap polyposis pathogenesis, by examining the mucus of patients and analysing the expression of five mucin genes, MUC2, MUC3,MUC4, MUC5AC, and MUC5B.Patient and methods—The study was performed on biopsy specimens taken from a patient with recurrent cap polyposis. Histochemical examination, electron microscopy, and mRNA in situ hybridisation were used.Results—The mucus of cap polyposis differed in three respects from that of normal adult colon: abnormal ultrastructure of the mucus in the goblet cells, predominance of non-sulphated mucins, abnormal expression of the MUC4, MUC3, andMUC5AC genes.Conclusions—Most of these abnormalities have been reported for other pathological situations, suggesting that the abnormalities observed in the mucus of this patient with cap polyposis are probably secondary phenomena rather than primary. However, the mucin abnormalities detected, which reflect deregulation of the expression of three apomucin genes, abnormal glycosylation, and abnormalities of the secretion process, are also probably involved in the clinical manifestations of cap polyposis.


2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Prajwal Boddu ◽  
C. Cameron Yin ◽  
Rashmi Kanagal-Shamanna ◽  
Guillin Tang ◽  
Beenu Thakral ◽  
...  

While rare, cases of isolated extramedullary disease of B-cell Lymphoblastic Lymphoma (B-LBL) without morphologic bone marrow involvement have been described. In this report, we illustrate the case of an elderly gentleman who presented with isolated testicular and vertebral LBL involvement but had no morphologic bone marrow involvement. The initial plan of treatment was to treat along the lines of Philadelphia negative B-ALL/LBL. During this time, fluorescence in situ hybridization (FISH) and PCR testing for BCR-ABL1 rearrangements were being performed on the marrow specimens as a part of routine diagnostic workup. While the FISH returned negative, PCR testing unexpectedly detected BCR-ABL1 fusion transcripts at a low level of 0.48%. Given their presence, we performed FISH for BCR/ABL1 rearrangement in both testicular and L5 vertebral specimens which were 80–90% positive. He subsequently received rituximab, hyper-CVAD, and dasatinib, along with prophylactic intrathecal prophylactic chemotherapy. The patient achieved a prolonged remission but eventually relapsed, 4 years later. Had it not been for this fortuitous discovery, the patient would not have been treated with tyrosine kinase inhibitors. We emphasize that FISH and PCR testing for BCR-ABL1 rearrangement are integral to arriving at an accurate diagnosis and should be routinely tested on B-LBL biopsy specimens.


2016 ◽  
Vol 40 (8) ◽  
pp. 1090-1099 ◽  
Author(s):  
Christopher J. VandenBussche ◽  
Ashley Cimino-Mathews ◽  
Ben Ho Park ◽  
Leisha A. Emens ◽  
Theodore N. Tsangaris ◽  
...  

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