摘要:

Lung alveolar macrophages (LAM), obtained by bronchoalveolar lavage of healthy donors, were separated into four subfractions on discontinuous gradients of Percoll and subjected to light micro-scopic, transmission (TEM) and scanning electron microscopic (SEM) studies. Alveolar macrophage morphometric analysis was performed on cytocen-trifuged preparations. TEM of subpopulations revealed considerable morphologic heterogeneity. By SEM, cells of the most dense (D) subtraction were small, round, and, typically, the surface was highly ruffled with small membrane pseudopods. Cells of the least dense subtraction (A) showed a low degree of membrane folding or filopodia and were often totally disorganized.In smokers, macrophages of fraction A had a greater area and perimeter compared with non-smokers, whereas the inverse relationship was observed for C and D cells. Also, the number of electron-dense inclusions and the level of acid phosphatase were higher in smokers than in non-smokers. Coupled with functional heterogeneity the morphologic differences described in this paper suggest that density-separated subpopulations of LAM may represent different stages of differentiation or maturation.

ISSN:0191-3123    

DOI:10.3109/01913128909051155

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

We describe a case of pancreatic tumor in a 65-year-old woman with typical glucagonoma syndrome. Plasma glucagon (GL) and pancreatic polypeptide (PP) were markedly elevated up to 1404 and 1 200 pg/ml, respectively. Histologic examination of the metastatic tumors in liver and lymph nodes showed endocrine-type tumors composed of GL-positive cells some of which coexpressed PP immunoreactivity. Electron microscopy revealed the tumor cells with single-type secretory granules similar to normal A cell granules. Double immunogold staining demonstrated both GL and PP immuno-reactivities in the same secretory granules. Biologic and diagnostic significance of coexpression of PP and GL in a single secretory granules of pancreatic endocrine tumors is discussed briefly.

ISSN:0191-3123    

DOI:10.3109/01913128909051156

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

We report an exceptional case of melanotic neuro-ectodermal tumor of infancy (MNTI) occurring in the soft tissue of the left thigh of a 6-month-old female infant. The tumor consisted mainly of small round cells (neuroblasts) arranged in cords and nests that were separated by broad fibrovascular areas. In addition, there were a few medium-sized tumor cells containing melanin pigment (melano-cytic cells) that in electron microscopy contained melanosomes as well as tonofilaments. Both tumor cell types immunostained for neuron-specific enolase (NSE) and vimentin, and the melanocytic cells reacted additionally with the antikeratin antibody KL1. Within the tumor stroma, neurofilament- and S-100-protein-positive neural cells and vimentin- and desmin-positive myofibroblasts were seen. Although densecore granules were demonstrated ultrastructurally in some neuroblasts, no immunostaining for chromogranin A, Leu-7, serotonin, or regulatory peptides was found. MNTI located in an extremity can be confused with malignant small round and blue cell tumors of childhood. The distinction between MNTI and these tumors is of clinical significance because MNTI, in most cases, is a benign tumor that, in contrast to the latter, can be cured by complete excision. The presence of a biphasic cell population with neuroblasts and melanocytic cells must be considered the main diagnostic feature of MNTI.

ISSN:0191-3123    

DOI:10.3109/01913128909051157

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

The characteristics of clear cells of an ependy-moma of the foramen of Monro have been studied by electron microscopy to precisely define its or-ganellar composition and to establish the tumor histogenesis. Our data confirm that the once-thought oligodendroglial is, in fact, an ependymal tumor. Both the scarce number of organelles, owing to the low degree of differentiation, and the abun-dance of hyaloplasmic lipid vacuoles can account for the clear appearance of these tumor cells.

ISSN:0191-3123    

DOI:10.3109/01913128909051158

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

We studied the fine structure of benign, premalignant and malignant melanocytic lesions induced in Dunkin—Hartley guinea pigs by means of topical application of 7,1 2-dimethyl-benzanthracene (DMBAI. The most noteworthy characteristics of the atypical melanocytes (melanocytic dysplasia and melanomas) were the variable morphology and structure, and, in particular, the aberrant character of the melanosomes. The melanocytes presented irregularity of nuclear outlines with requent lobulation. The heterochromatin was usually found in thick clumps reinforcing the nuclear membrane, and the nucleoli were usually multiple. The melanosomes were ellipsoidal and spherical with a pattern that was lamellar, concentric, incomplete, and even microgranular and microvesicular. The melanization was usually in thick, irregular clumps. Melanosome complexes were always present.

ISSN:0191-3123    

DOI:10.3109/01913128909051159

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Synaptophysin is a membrane glycoprotein (Mr38,000) found in small vesicles with clear content. It is present in neurons and in a variety of neuroen-docrine cells and neoplasms, including the neuroen-docrine carcinoma of the skin (Merkel cell tumor). We report the presence of synaptophysinlike immu-noreactivity in normal Merkel cells of the pig-snout epidermis and vibrissae. The immunostaining was primarily localized in the Merkel cell side opposite to the nerve terminal. This fact suggests that in Merkel cells, as well as in other neuroendocrine cells, synaptophysin could occur in small clear vesi-cles (accumulated in Merkel cells in the side oppo-site to the neurite) and not in the secretory gran-ules themselves (which are concentrated in the cellular side apposed to the neurite).

ISSN:0191-3123    

DOI:10.3109/01913128909051160

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Hematuria (HU) of tubular origin is described on the basis of ultrastructural investigations of two rejected human renal allografts. The red blood cells IRBC) got into the interstitium through the walls of the damaged intertubular capillaries, and, via ruptures of the tubular basement membrane (BM), they may pass from the interstitium into the tubular lumen, causing HU. Rupture of the tubular BM may develop owing to the enzymes released by interstitial inflammatory cells or to the difference in the interstitial and intratubular pressures. Some of the RBC already in the tubular lumen may penetrate between the epithelial cells and even between the epithelium and the BM, probably because of the locally increased intraluminal pressure. If the RBC reach the BM, the epithelial cells produce a new, thin BM above them, with disintegration of the outer older one, and, thus, the RBC may pass into the interstitium again. This phenomenon is called the tubulointerstitialis circulation of RBC.

ISSN:0191-3123    

DOI:10.3109/01913128909051161

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

We report a rare case of malignant oncocytic carci-noid of the pancreas including the diagnostic immu-nocytochemical and electron microscopic findings. In addition the tumor shows some unusual ultra-structural features: lamelliform cristae and cyto-plasmic and nuclear crystalline structures.

ISSN:0191-3123    

DOI:10.3109/01913128909051162

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0191-3123    

DOI:10.3109/01913128909051163

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0191-3123    

DOI:10.3109/01913128909051164

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor