Jaw osteonecrosis in patients treated with bisphosphonates: an ultrastructural study.

Osteonecrosis of the jaw is a severe bone disorder traditionally associated with periodontal disease, local malignancy, chemotherapy, glucocorticoid therapy, or trauma. Recently a growing number of publications reported the occurrence of osteonecrosis of the jaw in patients undergoing treatment with bisphosphonates. The mechanism by which bisphosphonates might contribute to the development of osteonecrosis of the jaw is far from being fully elucidated. Suppression of bone turnover, infection, tissue hypoxia and cellular toxicity were proposed as possible mechanisms by which bisphosphonates may exert adverse effects on bone metabolism. Here, we studied 25 consecutive patients treated with bisphosphonates for osteoporosis or tumoral pathologies. We provide good evidence of hyperactive osteoclastic bone resorption and suggest a direct cytotoxic effect of bisphosphonates on bone tissue through induction of osteocyte cell death. We also demonstrate that bisphosphonates only have limited adverse effects on bone vascular network.

Pathological findings in subsynovial connective tissue in idiopathic carpal tunnel syndrome.

Recent studies suggest that in patients with carpal tunnel syndrome, pathological changes occur in the subsynovial connective tissue. Such changes are non-inflammatory synovial fibrosis and vascular proliferation. Thickening of the tendon sheet may cause an increase of canal pressure and damages to the median nerve in the wrist; however, the causes of such events still remain to be clarified. We examined synovial specimens from 26 patients operated on for idiopathic carpal tunnel syndrome. Analysis included histological, ultrastructural and immunohistochemical examination in order to establish a pathological underlying pattern. An explanation for the pathogenesis of the found changes suggested. Our data confirm the presence of a non-inflammatory fibrosis with irregular bundles of collagen. De novo blood vessel formation was also noted. Interestingly the neo-angiogenesis consists of anomalous vessels and may be triggered from various cell types secreting vascular endothelial growth factor (VEGF), including macrophage-like elements similar to endothelial progenitor cells. Therefore, we believe that in the future a non-surgical management of carpal tunnel syndrome might be conjecturable via anti-VEGF drugs.

Mast cell and eosinophil interaction in gastric carcinomas: ultrastructural observations.

BACKGROUND: An increase in the number of mastocytes has been described in some human neoplasms, mainly in gastric and colorectal cancer. MATERIALS AND METHODS: A case of diffuse-type gastric carcinoma, mainly infiltrated by eosinophils and mast cells, was studied using light and electron microscopy. RESULTS: Using light microscopy, cell clusters containing one mast cell and one to three eosinophils were found in the tumour stroma. Electron microscopy of this unusual stromal element revealed that mast cells established areas of junctions with eosinophils. Moreover, focal polarized exocytosis of mast cell granules was found in the areas of junctions with eosinophils. Eosinophils in contact with mast cells showed signs of important in situ activation, such as alterations in the size and number of granules, cytoplasmic vacuoles, and scattered extracellular granules. CONCLUSION: Our ultrastructural study provides morphological evidence of cross-talk between activated mast cells and eosinophils that may play an important role in the enhancement of host immunity against cancer cells.

Gastric hepatoid adenocarcinoma with autophagy-related necrosis-like tumor cell death: report of a case.

A case of hepatoid adenocarcinoma of the stomach is presented. The characteristic features of the tumor are summarized on the basis of the authors' experience and the literature. Ultrastructural examination revealed patchy condensations of chromatin throughout the nucleus suggestive of necrosis-like programmed cell death (PCD). These nuclear alterations were associated with the occurrence of vacuoles and lipofuscins, conferring an autophagic phenotype to this PCD. Thus, the case reported here provides an example of autophagic-related necrosis-like PCD. Alternative PCDs are reviewed and their morphologic distinction is discussed.

Tissue expression and serum levels of periostin during pregnancy: a new biomarker of embryo-endometrial cross talk at implantation.

OBJECTIVE: The molecular aspects involved in human implantation include many elements that were first discovered due to their role in cancer cell metastasis. Periostin, a cell adhesion protein that allows the maintenance of cancer stem cells, may influence implantation. The objective of this experimental case-control study was to investigate tissue and serum expression of periostin during pregnancy, and evaluate the potential role of periostin in endometrial receptivity and embryo implantation. STUDY DESIGN: Forty-five subjects were included in the final analysis: 15 women who had experienced spontaneous pregnancy loss were enrolled as cases, and 30 healthy pregnant women awaiting voluntary pregnancy termination were enrolled as controls. For both cases and controls, trophoblastic and decidual tissues were collected at 12 weeks of gestation. Periostin expression in decidual and trophoblastic tissues was evaluated by immunohistochemical staining and reverse transcription polymerase chain reaction in cases and controls, and periostin serum levels was analyzed by Western blotting assays in cases, controls and non-pregnant female volunteers. RESULTS: Periostin mRNA and protein levels were higher in decidual and trophoblastic tissues from women undergoing voluntary pregnancy termination compared with women who had experienced spontaneous pregnancy loss. This finding was also reflected at serum level. CONCLUSIONS: Periostin may be a serum marker of good endometrial receptivity and embryo quality, and predictive of pregnancy evolution.

Degranulation patterns of eosinophils in advanced gastric carcinoma: an electron microscopic study.

Recruitment and activation of eosinophils have been studied intensely in asthma and other allergic diseases. Less is known about the infiltration and degranulation patterns of eosinophils in the tumor stroma. Seven cases of advanced gastric carcinomas were found to be massively infiltrated by eosinophils and studied by light and electron microscopy. Gastric carcinomas, despite having similar numbers of tissue eosinophils, exhibited markedly different degranulation patterns. In 2 cases, resting nondegranulating eosinophils were found. Piecemeal degranulation was the predominant mode of secretion from eosinophils localized within the tumor stroma in 4 cases. Eosinophil exocytosis and cytolysis were rarely observed. In 1 case, crystals morphologically similar to Charcot-Leyden crystals were observed at the extracellular level as well as in phagosomes of tissue macrophages, confirming active sequestrations of eosinophil Charcot-Leyden protein by macrophages in vivo. In the same case, eosinophils showed characteristic features of early and late apoptotic changes, such as condensed chromatin, focal dilatation of nuclear envelope, and preserved plasma membrane. Morphological association between apoptotic eosinophils and deposition of granules in the tumor stroma was found. Extracellular deposition of intact granules from apoptotic eosinophils was distinct from eosinophilic (necrotic) cytolysis, and has reported previously in experimental studies in vitro. To the knowledge of the authors, this case represents the first report of late apoptotic eosinophils that release their granules within the tumor stroma in a human gastric carcinoma.