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Biomedical subjects

P Barsotti

Publications and source records attributed to P Barsotti.

54 records · Page 3Linked to original sources
PubMed1988

Carbohydrate histochemistry of human Brunner's glands.

Brunner's glands are known to produce neutral mucins. In order to achieve a better knowledge of their carbohydrate profile, we used five peroxidase-labeled lectins on surgical specimens of human duodenum. This method allowed us to identify at least two different types of neutral mucins in Brunner's glands secretion, thus demonstrating a heterogeneous mucin production. The structure of terminal oligosaccharidic chains in these glycoproteins has also been hypothesized.

Brunner Glands↗
PubMed1988

Ultrastructural histochemical investigations of "dense deposit disease". Pathogenetic approach to a special type of mesangiocapillary glomerulonephritis.

Dense deposit disease is characterized by the presence of intramembranous dense deposits; their constituents are unknown but immunological and biochemical studies have demonstrated that they contain no gamma-globulins or any other plasma protein. In order to clarify the nature of the dense deposits better, we investigated their most distinctive character, (marked electron-density) by means of ultrastructural histochemistry techniques using thin sections from Formaldehyde fixed, OsO4 postfixed and Epon embedded specimens collected for diagnostic electron microscopy. The dense deposits have a higher osmium affinity than the lamina densa of normal basement membranes, and the electron-density is strictly osmium-dependent suggesting the presence of a lipid component. Further data, obtained using an extraction method for lipids, seems to confirm our hypothesis.

Adolescent↗
PubMed1988

Ultrastructural localization of sulphate glycoconjugates in the human glomerular capillary wall using the high iron diamine method.

The distribution of fixed anionic sites within glomerular capillary walls has been studied in man by applying two ultrastructural histochemical methods--the high iron diamine and dialysed colloidal iron methods--to tissue chopper sections and to isolated glomeruli obtained from surgical fragments of renal tissue. By using the high iron diamine method we have been able to demonstrate that in man, too, there are sulphate (possibly heparan sulphate proteoglycan) sites preferentially located in the lamina rara esterna of the basement membrane and in the cell coat of the urinary surface of podocytes. Non-sulphate (high iron diamine-negative, dialysed colloidal iron-positive) anionic sites have been identified not only in the glycocalyx of the epithelial and endothelial cells but also in the laminae rarae of the basement membranes, where they show a more extensive distribution pattern than sulphate sites. The proposed methods seem particularly suitable for the study of human renal tissue; they could, in fact, provide useful information about the behaviour of the various anionic components of the glomerular capillary wall in pathological conditions.

Basement Membrane↗
PubMed1987

Solitary polypoid hamartoma of the oxyntic mucosa of the stomach.

A solitary pedunculated polyp of the oxyntic mucosa removed from a 66-year-old patient with atrophic gastritis and achlorhydria exhibited distinctive histological features consisting of submucosal, mostly oxyntic-type glands with a smooth muscular framework. Histochemical and immunohistochemical studies demonstrated that the glands were composed of well differentiated chief, parietal, and endocrine cells. Moreover, less frequent glands of the antro-pyloric type were also seen. The lesion was regarded as a previously unrecognized variety of gastric hamartoma.

Aged↗
PubMed1987

B- and T-cell non-Hodgkin's lymphomas with large multilobated cells: morphological, phenotypic and clinical heterogeneity.

Ten cases of non-Hodgkin's lymphomas, mainly composed of large multilobated cells, have been studied. Our results are consistent with the view that they represent a somewhat heterogeneous group of lymphoid tumours displaying different morphological, clinical and immunophenotypic features. In B-cell type the large multilobated cells were histologically characterized by prominent nucleoli and distinctly basophilic cytoplasm whereas in the T-cell type they had indistinct or small nucleoli and ill-defined weakly eosinophilic cytoplasm. These differential features between B- and T-cell type were confirmed by electron microscopy. From a clinical standpoint B-cell type was characterized by a constant involvement of lymphoid tissues (lymph nodes and/or Waldeyer's ring); T-cell type showed, on the contrary, a more frequent involvement of extra-lymphoid sites (mainly bone and subcutaneous tissues). Our study provides some morphological features that may be helpful for a correct differential diagnosis in this heterogeneous group of non-Hodgkin's lymphomas.

Adolescent↗
PubMed1986

Immunoreactivity for S-100 protein in dendritic and in lymphocyte-like cells in human lymphoid tissues.

S-100 protein is an immunohistochemical marker for a subset of dendritic cells, the interdigitating reticulum cells (IDRCs), which are mainly located in T-dependent areas of lymphoid tissues. In the present study we have investigated the distribution of S-100-positive cells in lymph nodes, spleen, thymus and peripheral blood of normal subjects. Immunoreactivity for S-100 protein was demonstrated in large cells with dendritic morphology and in small lymphocyte-like cells present in the lymph node paracortex, thymic medulla, splenic periarterial lymphatic sheaths (PALS) and in peripheral blood. S-100-positive lymphocyte-like cells were frequently detected around high endothelial venules (HEV) and were present in numbers comparable to those of S-100-positive IDRCs. Immunoelectron microscopy confirmed the existence of positive cells with lymphoid morphology and revealed that the intracellular distribution of the immunoreaction product was similar in lymphoid and dendritic cells. Further characterization of S-100-positive cells demonstrated that both lymphoid and dendritic cells were unreactive with a large panel of monocytic and macrophage markers.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1985

Visualization of the secretory canaliculi of human parietal cells with a peroxidase-labelled peanut lectin. Light- and electron-microscopic observations.

Peanut lectin reactivity was examined in normal fundic glands from human gastric samples, both at light- and electron-microscopic levels, using a peroxidase conjugate. Positive reaction was observed in the glycocalyx of parietal cell secretory canaliculi as well as in the mucous globules of mucous cells and in the luminal cell coat of chief cells. The presence of terminal galactose in the canalicular glycocalyx may be connected with the peculiar function of hydrochloric acid secretion. Peroxidase-labelled peanut lectin is proposed as a marker for visualizing the secretory canaliculus of parietal cells.

Galactose↗
PubMed1985

The Omenn's syndrome: histological, immunohistochemical and ultrastructural evidence for a partial T cell deficiency evolving in an abnormal proliferation of T lymphocytes and S-100 +/T-6 + Langerhans-like cells.

A 7 month old female infant was affected by a rapidly fatal familial disease highly reminiscent of Omenn's syndrome. She presented with widespread eczematous lesions, hepatosplenomegaly, superficial lymphadenopathy, peripheral blood lymphocytosis, eosinophilia and hyper-IgE. An axillary lymph node was involved by a marked proliferation of T-3 +/T-10-- lymphocytes admixed with S-100+/T-6+/Leu-3a+/Ia + reticular cells which lacked typical LC granules; cell suspension study revealed that 90%-96% of the lymph node cells were T-11+/T-3+ lymphocytes characterized by low expression of Leu-3a and T-8 antigens and by high expression of Ia antigens (52%). Peripheral blood T lymphocytes exhibited a similar distribution of surface phenotypes. The patient died of interstitial pneumonia and an autopsy was performed. The thymus was markedly atrophic and completely devoid of lymphocytes. The peri-arteriolar lymphoid sheets of the spleen were poorly developed and were mainly composed of T-8+ lymphocytes. The mediastinal nodes were rudimentary and were populated by T-3+/T-10+ lymphocytes with low expression of Leu-3a and T-8 antigens. Our results raise the possibility that Omenn's syndrome is a peculiar primary immunodeficiency in which, despite early thymic involution, some abnormal T lymphocytes still develop in the peripheral lymphoid organs. Antigenic triggering of these cells might result in prominent proliferations of T lymphocytes and Langerhans-like cells which lead to the clinical manifestation of the disease.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1985

Systemic lymphadenopathy (LAS) in intravenous drug abusers. Histology, immunohistochemistry and electron microscopy: pathogenic correlations.

In the present study we have evaluated the histological, immunohistochemical, ultrastructural and cell surface phenotypic features of lymph nodes from 19 intravenous drug abusers and two homosexual men with persistent lymphadenopathy syndrome and from six control patients. Our investigation has demonstrated that the lymphadenopathy of drug abusers is characterized by: (a) specific histological features with evidence of evolution from an initial hyperplastic-reactive to a late regressive-destructive stage; (b) T-cell surface phenotype distribution similar to that in the peripheral blood of homosexuals; (c) peculiar infiltration of the germinal centres by T8+ cells and by S-100+, T6+ interdigitating reticulum-like cells; (d) electron microscopic features indicating the presence of virus bodies in lymph node cells and in the intercellular spaces. These data suggest that the lymphadenopathy of drug abusers and homosexuals are similar pathological conditions with characteristic features which allow histological differentiation of this entity from those found in other viral infections.

Female↗
PubMed1984

Effects of sulindac and ibuprofen in patients with chronic glomerular disease. Evidence for the dependence of renal function on prostacyclin.

We investigated whether the glomerular synthesis of prostacyclin modulates the renal blood flow and glomerular filtration rate in chronic glomerular disease. The urinary excretion of 6-keto-prostaglandin F1 alpha, a stable breakdown product of prostacyclin, was significantly (P less than 0.01) reduced in 20 women with chronic glomerular disease, as compared with 19 controls, whereas excretion of urinary prostaglandin E2 was unchanged. In 10 patients randomly assigned to one week of treatment with ibuprofen, excretion of urinary 6-keto-prostaglandin F1 alpha and prostaglandin E2 was reduced by 80 per cent, the level of serum creatinine was increased by 40 per cent, and creatinine and para-aminohippurate clearances were reduced by 28 and 35 per cent, respectively. The reduction of both clearances was inversely related (P less than 0.01) to the basal urinary excretion of 6-keto-prostaglandin F1 alpha but not of prostaglandin E2. No functional changes were detected in five healthy women, despite a similar suppression of renal prostacyclin synthesis by ibuprofen. In contrast, one week of treatment with sulindac did not affect renal prostacyclin synthesis or renal function in the other 10 patients, despite a marked inhibition of extrarenal cyclooxygenase activity. We conclude that in patients with mild impairment of renal function, the renal blood flow and glomerular filtration rate are critically dependent on prostacyclin production. In such patients sulindac may be a safe substitute for other nonsteroidal antiinflammatory drugs.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

S-100+ lymph node neoplasm. Report of a case with histological AL and immunological features intermediate between T cell lymphoma and malignant histiocytosis.

A 16-yr-old white female was affected by continuous fever, pancytopenia with relative increase of T-8 lymphocytes, severe bone marrow hypoplasia, generalized lymphadenomegaly and splenomegaly. A first lymph node biopsy, obtained at the onset of the disease, was involved by a paracortical tumor with some S-100+ "lymphocyte-like" cells in the neoplastic areas; in the cell suspension, 70-80% of cells were E4+/E37+ lymphocytes with prevalent expression of the T-8 phenotype (52%). A second lymph node biopsy, obtained five months later, was involved by a diffuse proliferation of S-100+ cells with high mitotic activity; in the cell suspension, the majority of cells were E-/T-11+/T-3+/T-8+. At the TEM level, the neoplastic cells were characterized by regular or indented nuclei with finely dispersed chromatin and by regular or indented nuclei with finely dispersed chromatin and by irregular cytoplasmic profiles with thick pseudopodia-like projections. The possibility is discussed that this neoplasm may share some similarities with the T-gamma lymphoma being part of a poorly described group of tumors with intermediate features between T cell lymphoma and malignant histiocytosis.

Adolescent↗
PubMed1983

Adenosquamous carcinoma of the stomach: histological, histochemical and ultrastructural observations.

The histochemical and ultrastructural features of an adenosquamous carcinoma of the stomach have been studied. Both the adenomatous and the squamous component of the tumour showed malignant characteristics. Elements which were considered as undifferentiated cells on light microscopy showed ultrastructural features of poorly differentiated squamous cells. No intermediate cells, sharing squamous and glandular aspects, were found by electron microscopical examination. The adenomatous component exhibited histochemical and ultrastructural features of the intestinal type of gastric carcinoma and the mucosa surrounding the tumour showed a colonic type of intestinal metaplasia. A possible histogenesis from a totipotential undifferentiated cell is considered.

Adenocarcinoma↗
PubMed1980

Multiple myeloma and acute myelomonocytic leukemia: simultaneous occurrence without previous chemotherapy.

A patient with acute myelomonocytic leukemia was found to have IgG paraprotein on serum electrophoresis Bence Jones K proteinuria and increased plasma cells (30%) on marrow examination. The simultaneous occurrence of the two diseases was well documented by cytochemical immunological and electron-microscopic findings. Bone marrow chromosome investigations showed an abnormal karyotype: hypodiploidy was prevalent and marker chromosomes were present. A possible relationship between acute leukemia and multiple myeloma is discussed.

Aged↗
PubMedDate not supplied

Increased retinal endothelial cell monolayer permeability induced by the diabetic milieu: role of advanced non-enzymatic glycation and polyol pathway activation.

BACKGROUND: Increased vascular permeability could be involved in the pathogenesis of diabetic retinopathy. The present study was aimed at assessing whether high glucose concentrations can impair retinal endothelial cell barrier function directly, irrespective of changes in other determinants of permeability, and the role of non-enzymatic glycation and polyol pathway activation in these alterations. METHODS: Bovine retinal endothelial cells (BREC) were exposed for various periods to high glucose vs iso-osmolar mannitol and normal glucose containing media+/-agents mimicking or inhibiting advanced glycation end product (AGE) formation and polyol pathway activation. Monolayer permeability was assessed by measuring the transendothelial passage of (125)I-labeled proteins. RESULTS: Permeability increased significantly (up to +70%) in BREC exposed to high glucose, but not to mannitol, for 1-30 days, vs normal glucose control cells. Exposure to AGE-modified bovine serum albumin (BSA) (> or = 90%) and, to a lesser extent, sorbitol (+28%) mimicked the high glucose effect. The AGE formation and nitric oxide synthase (NOS) inhibitor aminoguanidine significantly reduced (by 60%) changes induced by 30-day exposure to high glucose, whereas methylguanidine, which inhibits only NOS activity, did not affect permeability. Aldose reductase or sorbitol dehydrogenase inhibitors decreased (by approximately 40%) the enhanced leakage produced by 1-day, but not 30-day, incubation in high glucose. CONCLUSIONS: The present results indicate that high glucose is capable of impairing retinal endothelial cell barrier function directly and that non-enzymatic glycation and polyol pathway activation may mediate these changes, with AGEs participating in the long-term alterations and increased flux through the sorbitol pathway in the short-term effect.

Animals↗
PubMedDate not supplied

Ultrastructural changes in HEp-2 cells treated with staphylococcal alpha-toxin.

The effect of highly purified staphylococcal alpha-toxin on HEp-2 neoplastic cells growing in culture was studied by electron microscopy. In addition to some nuclear modifications, the most significant morphological changes were in mitochondrial structure, alpha-toxin seems to induce a defined sequence of changes in mitochondrial configuration which can be summarized as an earlier phase of 'condensation' of mitochondrial structure and a later phase of mitochondrial swelling with an intermediate 'transitional' configuration. The significance of these findings is discussed in the light of the present state of knowledge of the biological characteristics of staphylococcal alpha-toxin.

Bacterial Toxins↗