Mechanism of interaction of hydrocalumites (Ca/Al-LDH) with methyl orange and acidic scarlet GR

The development of new materials for water purification is of universal importance. Among these types of materials are layered double hydroxides (LDHs). Non-ionic materials pose a significant problem as pollutants. The interaction of methyl orange (MO) and acidic scarlet GR (GR) adsorption on hydrocalumite (Ca/Al-LDH-Cl) were studied by X-ray diffraction (XRD), infrared spectroscopy (MIR), scanning electron microscope (SEM) and near-infrared spectroscopy (NIR). The XRD results revealed that the basal spacing of Ca/Al-LDH-MO was expanded to 2.45 nm, and the MO molecules were intercalated with a inter-penetrating bilayer model in the gallery of LDH, with 49o tilting angle. Yet Ca/Al-LDH-GR was kept the same d-value as Ca/Al-LDH-Cl. The NIR spectrum for Ca/Al-LDH-MO showed a prominent band around 5994 cm-1, assigned to the combination result of the N-H stretching vibrations, which was considered as a mark to assess MO- ion intercalation into Ca/Al-LDH-Cl interlayers. From SEM images, the particle morphology of Ca/Al-LDH-MO mainly changed to irregular platelets, with a “honey-comb” like structure. Yet the Ca/Al-LDH-GR maintained regular hexagons platelets, which was similar to that of Ca/Al-LDH-Cl. All results indicated that MO- ion was intercalated into Ca/Al-LDH-Cl interlayers, and acidic scarlet GR was only adsorped upon Ca/Al-LDH-Cl surfaces

Perivascular epitheloid cell tumour (PEComa) of the retroperitoneum – a rare tumor with uncertain malignant behaviour: a case report

<p>Abstract</p> <p>Introduction</p> <p>Perivascular epitheloid cell tumours are rare mesenchymal neoplasms characterized by a proliferation of perivascular cells with an epitheloid phenotype and expression of myomelanocytic markers.</p> <p>Case presentation</p> <p>Here we present the case of a cystic perivascular epitheloid cell tumour of the retroperitoneum associated with multifocal lung lesions. A 27-year-old woman underwent laparotomy to remove a 10 × 6 × 4 cm sized retroperitoneal mass. The resected specimen was subjected to frozen and permanent histological sections with conventional and immunohistochemical stains, including antibodies against HMB45. The tumour displayed the typical morphological and immunohistochemical features of a perivascular epitheloid cell tumour. Focal necrosis and a proliferative index of 10% suggested a malignant potential. Moreover, postoperative computed tomography scans demonstrated multiple lung lesions, which were radiologically interpreted as being most likely compatible with lymphangioleiomyomatosis.</p> <p>Conclusion</p> <p>Since lymphangioleiomyomatosis, an otherwise benign condition, belongs to the family of perivascular epitheloid cell tumours, it cannot be excluded that the lung lesions in this case in fact represent metastases from the retroperitoneal perivascular epitheloid cell tumour rather than independent neoplasms. More experience with this new and unusual tumour entity is clearly needed in order to define reliable criteria for benign or malignant behaviour.</p

EXPRESSION OF ADHESION MOLECULES IN LANGERHANS CELL HISTIOCYTOSIS

Expression of adhesion molecules was investigated in six biopsy specimens of Langerhans' cell histiocytosis using immunocytochemistry. Cells with Langerhans' cell histiocytosis morphology were stained for ICAM-1, for the beta-1 integrins alpha-4 (VLA-4) and alpha- 5 (VLA-5), and for the beta-2 integrins 1,FA-1. MAC-1 and p150,95. This pattern of reactivity was different from that of epidermal Langerhans' cells of the normal skin which were not immunostained. A variable number of CD68+ multinucleated giant cells was present in five biopsies. They were less reactive than the cells of Langerhans' cell histiocytosis for alpha-4 (VLA-4) and LFA- 1, were positive for MAC-1 and p150,95 and were characterized by prominent expression of the beta-1 integrins alpha-2 (VLA-2), alpha- 3 (VLA-3) and of VnR (alpha-v/beta-3). The repertoire of adhesion molecules expressed by giant cells is indicative of profound cell-matrix interactions, whereas that of Langerhans' histiocytosis cells suggests particularly active cell-cell interactions. Blood vessels of the lesions were stained for beta-1 integrins, for vitronectin receptor and for molecules involved in adhesion and trans-endothelial migration of circulating leukocytes, such as ICAM-1, VCAM-1 and E-selectin. Additional findings were the observation of CD1a+ multinucleated giant cells in a single case, suggesting a possible lineage relationship with the histiocytosis cells, and the demonstration of some Ki-67 + Langerhans' cell histiocytosis cells and CD1a+ mitotic figures in four of six cases, indicating local proliferation of Langerhans' histiocytosis cells

Immunohistochemical demonstration of p24 HTLV III major core protein in different cell types within lymph nodes from patients with lymphadenopathy syndrome (LAS).

The p24 protein is the major core protein of LAV/HTLV III which is the putative agent of the lymphadenopathy syndrome. By the use of an anti-p24 monoclonal antibody we have studied the presence of LAV/HTLV III infected cells in 20 lymph nodes obtained from lymphadenopathy syndrome patients: 14 lymph nodes were characterized by prominent follicular hyperplasia consistent with the early phase of the syndrome and six lymph nodes presented marked regressive changes. Cells positive for p24 were detected in 8/14 lymph nodes with hyperplastic changes and in 1/6 lymph nodes with regressive changes. Positive cells were most often located in germinal centres and were mainly characterized by a lymphoid morphology. However, immunoreactivity for p24 protein was also occasionally observed in some histiocytic-like cells and in high endothelial cells of post-capillary venules, suggesting that these 'accessory cells' also play a role in the early phases of the lymphadenopathy syndrome