Ultrastructural distribution of lectin-binding sites on gastric superficial mucus-secreting epithelial cells The role of Golgi apparatus in the initial glycosylation

<p>Normal human gastric epithelial cells were ex-amined by electron microscopy using each of five bi-otinylated lectins [Ulex europaeus agglutinin I (UEA-I), peanut agglutinin (PNA), wheat germ agglutinin (WGA), soybean agglutinin (SBA) and Dolichos biflorus agglutin-in (DBA)] as a probe. We employed 35 gastric surgical specimens removed from complicated peptic disease. The lectin-binding sites were revealed with streptavidin-col-loidal gold complex. All specimens were embedded in Spurr and LR White resins. In superficial foveolar epithe-lial cells, the lectins used were generally positive in all cell types (mainly UEA-1 and PNA) on the Golgi region and mucus cytoplasmic vacuoles, with many variations among cells in the same case. On the other hand, extracel-lular mucus was negative for WGA. Labelling with PNA revealed a biphasic pattern (peripheral positivity) on mu-cous droplets in surface and fove01ar cells. The cis side of the Golgi apparatus was labelled with SBA and PNA and rough endoplasmic reticulum with SBA (only five cases). Lectin-binding variability could be related to het-erogeneous composition of gastric mucus. Our results with SBA suggest initiation of O-glycosylation at the Golgi apparatus; however a role of the rough endoplas-mic reticulum cannot be excluded (N-glycosylation). We propose the following sequence of sugar addition to the carbohydrate side-chains of gastric glycoproteins: (1) GaNAc (Golgi apparatus cis-side), (2) GlcNAc (Golgi ap-paratus intermediate face), (3) GalNac or Gal, C~-L-fucose (Golgi apparatus trans-side).</p

Cell proliferation in skin tumors with ductal differentiation: patterns and diagnostic applications

<p>The kinetic features of skin tumors with ductal differentiation (TDD) remain mainly unknown. We selected 88 skin TDD (D-PAS-positive cuticles) classified according to Murphy and Elder's criteria. Tumors studied included 13 poromas, 12 nodular hidradenomas, 10 cylindromas, 6 spiradenomas, 9 syringomas, 9 chondroid syringomas, 7 porocarcinomas, 15 malignant nodular hidradenomas, and 7 not otherwise specified carcinomas. The same tumor areas were evaluated for mitotic figure counting (MFC) and proliferation rate (PR = MIB-1 index), screening 10 consecutive high-power fields (HPFs) in the most cellular areas. Results were recorded by HPF and tumor cellularity, considering both average and standard deviation. Differences were analyzed by Student's t-test and analysis of variance (ANOVA) and considered significant if p</p

Mixed cloacogenic carcinoma of male urethra

<p>Diagnostic features of poorly differentiated carcinoma with cloacogenic features of the male urethra.</p

Cutaneous ganglion cell choristoma. Report of a case

<p>We describe the histological, immunohistochemical, and ultrastructural findings of a cutaneous tumour composed of ganglion cells, without any other proliferating component. As ganglion cells are not normal components of the skin, we propose the term “ganglion cell choristoma” for this lesion. The differential diagnosis of related lesions such as cutaneous ganglioneuroma, well-differentiated metastases from neuroblastoma, autonomic ganglia entrapped by neuroflbroma, and reactive processes, and the possible histogenesis of ganglion cell choristoma are discussed.</p

Paragangliomas. Static cytometric studies of nuclear DNA patterns

<p>The biologic behavior of most paragangliomas cannot be predicted from their histologic appearance. Recently, cytometric studies have found an association between an aggressive clinical behavior and the presence of a hyperdiploid or tetraploid range in the DNA nuclear content.<br> The authors have studied morphometric (nuclear area and nuclear form factor) and DNA densitometric (integral optical density and DNA ploidy) features of 23 cases of paraganglioma by means of slide cytophotometry with the microTICAS system (University of Chicago, Chicago, IL). The samples were selected from paraffin-embedded tissue, and representative sections were stained with the Feulgen technique. The differences between groups (cervical versus extracervical paragangliomas) were investigated with the Mann-Whitney test and Fisher discriminant linear function.<br> The densitometric study showed aneuploid cell lines in 15 of 16 noncervical paragangliomas (with a DNA index within the tetraploid range), whereas 3 of 7 cervical paragangliomas were aneuploid and only 1 case did not have not a diploid cell line (with a DNA index within the peridiploid range). Mean ploidy (4.33 arbitrary units [AU] and 2.72 AU, respectively), nuclear area (58.74 microns 2 and 32.08 microns 2, respectively), the minor and major DNA indices (1.09-1.24 and 1.83-1.96, respectively), and DNA content variability (2c deviation indices [2cDI] of 8.62 and 1.88 AU, respectively) were higher in noncervical paragangliomas. With Fisher linear discriminant function, mean nuclear area (P = 0.0008), 2cDI (P = 0.0030), and the minor DNA index of each cell proliferation were correlated with location. None of the variables established statistically significant differences in comparisons of malignant and benign paragangliomas.<br> Karyometric and DNA densitometric parameters have limited value in determining the prognosis of paragangliomas, although they are correlated with tumoral location, which is still an indicator in establishing the prognosis of these neoplasms.</p

Nuclear DNA patterns in adrenal cortex proliferative lesions

<p>In cortical adrenal gland tumours there are discrepancies between morphological criteria for malignancy and biological behaviour. This makes it difficult to select the appropriate treatment. We have studied morphometric and DNA densitometric features of 24 adrenal proliferative lesions (hyperplasia, adenoma, and carcinoma) by means of slide cytometry. All variables have been correlated with pathological diagnosis. The samples were selected from paraffin-embedded tissue, and representative lesions were Feulgen stained. Densitometric study showed aneuploid cell lines in every carcinoma, 5 of 8 adenomas, and 5 of 10 hyperplastic lesions. Both DNA nuclear content (mean ploidy of 2.11 c, 2.41 c, and 3.05 c) mean nuclear area (average of 31.26 microns 2, 35.92 microns 2, and 42.39 microns 2) showed progressive increase from hyperplasia to adenoma, and carcinoma. Mean shape factors were lowest in adenomas (1.69) and highest in carcinomas (1.82). Those karyometric variables which showed statistically significant differences (p < 0.05) among diagnostic groups were included in a stepwise three-way discriminant analysis. Only three parameters, shape factor (p = 0.0008), mean ploidy (p = 0.0012), and adrenal weight (p = 0.0055) persisted as independent predictive factors. Using the three variables selected by discriminant analysis on our cases, 100% of the adenomas were correctly classified, 83% of the carcinomas, and 80% of the hyperplasias. Tumour weight and nuclear shape factor differentiated adrenal cortex adenoma from carcinoma, while mean ploidy distinguished adrenal cortical hyperplasia from carcinoma. Nuclear pleomorphism (shape factor) and DNA-ploidy are the most important nuclear features in predicting the biological course of proliferative adrenal cortex lesions, although by themselves they are not bona-fide discriminators.</p