Scanning electron microscopy in early human bladder neoplasia

Biopsies of healthy looking urothelium from 61 patients with transitional cell carcinoma (TCC) of bladder were examined by scanning electron microscopy (SEM) and light microscopy. A proportion (40 %) showed abnormal features on SEM, in particular pleomorphic microvilli (PMV) in at least one area. SEM appearances were graded into four categories depending upon divergence from normal. Patients were followed up at cystoscopy and one year later a strong correlation was noted between original abnormal SEM appearances and subsequent tumour recurrence. These early results suggest that SEM could be helpful in the diagnosis, assessment, and clinical management of the unstable urothelium.     

Scanning electron microscopy of normal, neoplastic and inflamed human bladder

Scanning electron microscopy (SEM) was used to compare the topographic fine structure of urothelium from normal, neoplastic and inflamed human bladders. The three groups of patients show different patterns. The normal bladder lining is characterized by regularly arranged large superficial cells with ridged surfaces. By contrast, the surface cells of a transitional cell carcinoma are rounded up and covered with microvilli. In some patients with cystitis or post inflammatory hyperplasia SEM appearances intermediate between normal and neoplastic patterns are encountered. However, except in extremely severe cystitis it is possible on SEM to differentiate between inflamed and neoplastic urothelium. Surface microvilli provide a useful malignant marker for transitional cell carcinoma. However, severe inflammation of the bladder, when diagnosed on cystoscopic examination, can and must be excluded by light microscopy before this marker is considered diagnostic for neoplasia.     

The 3D structure of the human urinary bladder mucosa: a scanning electron microscopy study

We performed a scanning electron microscopy study on the human urinary bladder tunica mucosa. Specimens from bladder biopsies were treated with OsO4 maceration and 1N NaOH maceration methods prior to SEM observation to disclose the three-dimensional organization of the lamina propria, basal lamina and urothelium. The lamina propria housed a well developed capillary plexus just below the basal lamina; the urothelium presented a typical three-layered organization with basal, intermediate and superficial cells. The intermediate cells appeared essentially similar to basal cells in their external features and stretched from the basal lamina up to the superficial layer. The most superficial cells appeared consistently flattened and interconnected by extensive junctional complexes. They showed a peculiar specialization, their apical plasmalemma being thickened with distinctive, stiff plaques, in contrast with the underlying globular or spindle-shaped cells whose plasmalemma was only covered by short microvillosities.     

Pancreatic carcinoma in infancy. An electron microscopic study.

A case of a malignant epithelial tumor of tail of the pancreas in a 3-year-old Japanese girl is presented. This is the fourth case reported with ultrastructural study. This type of pancreatic carcinoma of the infant has no endocrine granules or endocrine function. The ultrastructural study suggests that the tumor is derived from a primitive epithelial cell with differentiation toward acinar cell.     

Intraepithelial lumina in urothelial bladder neoplasms. A histochemical, immunohistochemical and electron microscopy study

Intraepithelial lumina observed in 12 urothelial bladder neoplasms were studied histochemically, immunohistochemically and ultrastructurally. Both intercellular and intracytoplasmic lumina could be demonstrated showing an alcianophilic margin and containing non-sulphated acid mucins. The presence of secretory component (SC) was identified in neoplastic urothelial cells around or adjacent to intercellular lumina as well as in cells with intracytoplasmic lumina. The cells surrounding intercellular lumina revealed ultrastructurally tight junctions, microvilli and a prominent glycocalyx while cellular remnants were found quite often within the lumen. As similar histochemical, immunohistochemical and ultrastructural characteristics are also expressed in surface umbrella cells of normal urothelium it is suggested that a focal differentiation of neoplastic urothelial cells towards surface umbrella-like cells takes place and that this process is intimately related to the formation of lumina.     

Megakaryoblastic transformation of chronic granulocytic leukaemia. An electron microscopy and cytochemial study.

Morphological, cytochemical, and ultrastructural electron microscopic (EM) studies were performed on blood and bone-marrow cells of case of Ph1-positive chronic ganulocytic leukaemia in megakaryocytic acute transformation. The entire leukaemic cell population was found to consist and of megakaryoblasts and megakaryocytes. Intermediate stages of maturation between blasts and micromegakaryocytes were observed at EM level.     

Frequency of intraendothelial `virus-like' particles: An electron microscopy study of 376 human renal biopsies

Intraendothelial `virus-like' particles were found in all cases requiring a renal biopsy: in 89% of patients with systemic lupus erythematosus (SLE), in 73% of those receiving renal transplants more than one year before, and in 24·5% of all other renal biopsies.     

A study by scanning electron microscopy of the bladder epithelium of the guinea pig

Under scanning electron microscopy (SEM) the surface cells of the guinea pig bladder have pentagonal or hexagonal outlines. Their borders are clearly defined since they are elevated. They possess a large reserve of surface membrane which is markedly folded and wrinkled when the bladder is empty. The folds disappear and the cells become flat during distension. The luminal surface is characterized by numerous reticular ridges which are a remarkably constant feature and persist even under acute artificial distension. A small proportion of the surface cells are small and have less than five sides. Since they show only sparse microvilli as a surface feature, they have a smooth appearance. These are believed to be young surface cells which have just emerged from the intermediate layer, and have not yet acquired the ridged pattern of mature cells.     

Light and electron microscopy of parathyroid carcinoma

Summary The morphology of three cases of parathyroid carcinoma is described, including the electron microscope findings in two of these cases. The clinical and morphologic points for the tentative diagnosis of parathyroid carcinoma are discussed. The malignancy of a parathyroid tumour is proved by lymphogenic or hematogenic metastases, by histological evidence of tumour infiltration into the surrounding tissues (including macroscopic adherence and sometimes vocal cord paralysis), and by cytologic evidence of mitoses. Nuclear atypism is often present but is neither a necessary nor an adequate proof of malignancy, because it is also seen in benign adenomas and in hyperplastic parathyroids. The ultrastructure of the carcinoma cells was also characterized by nuclear atypism and mitoses. In one carcinoma, the contents of cytoplasmic organelles varied in different cells, indicating various endocrine activity of the tumour cells. In another parathyroid carcinoma with low endocrine activity, copious cytoplasmic organelles and many secretory granules were found. There seem to be three possible causes of non-functioning parathyroid carcinomas: 1. lack of hormone synthesis, 2. impairment of cellular hormone secretion, 3. synthesis of a pathologic protein with defective endocrine activity.Supported by DFG, Sonderforschungsbereich 34 Endokrinologie.     

The vomeronasal organ in the frog, Rana esculenta. An electron microscopy study

The ultrastructure of the vomeronasal organ (Jacobson's VNO) of the frog, Rana esculenta, was studied under the transmission and scanning electron microscope. Four cell types were identified: ciliated, bipolar, glial-like, and basal. Ciliated cells are unique to the frog VNO and show morphological evidence of secretion; bipolar (neuronal) cells are arranged in columns and reach the free surface of the epithelium with knobs bearing microvilli. The latter are in contact with amorphous material not described previously. Glial-like cells wrap bipolar cells in the epithelium and poorly differentiated basal cells are found just over the basal lamina. The vascular pump described in mammal VNO is not present at all in the frog VNO. We conclude that in the frog the VNO is closer to the reptilian than the mammalian VNO, although the frog VNO shows some unique morphological characteristics.     

An electron microscopic study of intestinal metaplasia in human gallbladder.

Areas of intestinal metaplastic epithelium in gallbladders removed by cholecystectomies performed for gallstones were studied with the electron microscope. Three gallbladders contained areas of goblet cells and endocrine enterochromaffin-like cells and one gallbladder also Paneth cells. The goblet cells contained mucin granules of slightly variable size and shape and relatively great electron lucency. The intervening columnar epithelial cells contained various amounts of electron-lucent mucin granules. The round or oval enterochromaffin-like cells rested on the basement membrane, and in these cells the small, round, electron-opaque secretory granules were located in the infranuclear region. The supranuclear cytoplasm of the Paneth cells in the intestinalized epithelium contained typical large, round secretory granules. The fine structures of the various cells in the metaplastic epithelium bore resemblance to those of the cells in the intestinalized stomach mucosa.     

Light and electron microscopy study of capillaries in normal and inflammatory human synovial membrane.

Synovium aspirated from the knee joint by trochar was studied by light and electron microscopy in 40 cases of inflammatory arthritis and in 10 controls. The morphology of synovial capillaries, extravascular plasma diffusion, interendothelial vascular gaps, extracapillary blood cell migration, vascular congestion, endothelial hyperplasia, and obliteration of the capillary lumen by endothelial cells were compared in normal and inflammatory synovia. Inflammatory synovitis was characterised by the number and diversity of blood cells migrating through the interendothelial pathway out of the capillary lumen. Polymorphonuclear leucocytes were the blood cells most often seen at interendothelial junctions. No other capillary changes that might be related to synovial inflammation were found.     

Investigation of human chromosome polymorphisms by scanning electron microscopy.

Human chromosome polymorphisms were investigated by scanning electron microscopy (SEM). Centromeric heterochromatin was of a constricted morphology. The extent of the C banded region was demarcated by a prominent circumferential groove in G banded chromosomes. Circumferential grooves were observed within the heterochromatin of chromosome 9, and the number of grooves present reflected the size of the region. Three dimensional viewing of satellites and short arms of acrocentric chromosomes, from different angles in the SEM, provided the opportunity for accurate assessment of the size of satellites to be made. Also, small morphological variations were defined in the SEM when definition was uncertain in the light microscope (LM).     

Scanning electron microscopy of bacterial biofilms on indwelling bladder catheters

Fifty Foley bladder catheters that had been indwelling for periods ranging from 3 to 83 days (mean 35 days) were examined for the presence of bacterial biofilm. Scanning electron microscopy on freeze-dried cross-sections and fixed, critical point-dried longitudinal sections revealed biofilm formation on the luminal surfaces of 44 of the catheters. Culture of urine samples and sonicates from catheters revealed that the prevalence of bacteriuria was less than that of catheter colonization. A wide range of nosocomial species were found colonizing the catheters,Escherichia coli being most often isolated. The bacterial composition of the biofilms ranged from single species to mixed communities containing up to four species. There was no relationship between the length of time that the catheter had been in situ and the extent of biofilm formation. The biofilms varied in thickness from 3 to 490 µm and were visible as layers of bacterial cells up to about 400 cells deep, embedded in a matrix.