Region specific Raman spectroscopy analysis of the femoral head reveals that trabecular bone is unlikely to contribute to non-traumatic osteonecrosis.

Non-traumatic osteonecrosis (ON) of the femoral head is a common disease affecting a young population as the peak age of diagnosis is in the 40 s. The natural history of non-traumatic ON leads to a collapse of the femoral head requiring prosthetic replacement in a 60% of cases. Although trabecular bone involvement in the collapse is suspected, the underlying modifications induced at a molecular level have not been explored in humans. Here, we examine changes in the molecular composition and structure of bone as evaluated by Raman spectroscopy in human end-stage ON. Comparing samples from femoral heads harvested from 11 patients and 11 cadaveric controls, we show that the mineral and organic chemical composition of trabecular bone in ON is not modified apart from age-related differences. We also show that the molecular composition in the necrotic part of the femoral head is not different from the composition of the remaining 'healthy' trabecular bone of the femoral head. These findings support that quality of trabecular bone is not modified during ON despite extensive bone marrow necrosis and osteocyte death observed even in the 'healthy' zones on histological examination.

Laparoscopic resection of small bowel lipoma causing obscure gastrointestinal bleeding.

Small bowel lipomas are rare gastrointestinal benign neoplasms, whose signs and symptoms are often obscure. When symptoms are clinically present, one of the most common is usually gastrointestinal (GI) bleeding. It is very difficult to make a precise preoperative diagnosis in the absence of evident signs. Definitive diagnosis can only be made through histopathological examination, after the surgical resection. We report a case of obscure and persistent GI bleeding in a 78-year-old woman. Through the combination of endoscopy and computed tomography (CT), it was possible to identify a small bowel lesion, being its direct cause. CT showed a certain fat component within the mass pinpointing the hypothesis of a lipoma. We then performed a laparoscopic resection of 21 cm of the middle jejunum, including the mass and an intussusception. The results of the subsequent histopathological examination of the resected specimen allowed us to conclude that the lesion was an intestinal lipoma. Surgical resection appears to be the most successful approach as good short- and long-term results are achieved.

Interaction between DMBT1 and galectin 3 is modulated by the structure of the oligosaccharides carried by DMBT1.

DMBT1 (deleted in malignant brain tumor 1), a human mucin-like glycoprotein, belonging to the scavenger receptor cysteine-rich (SRCR) superfamily, is mainly secreted from mucosal epithelia. It has been shown previously that interaction of hensin, the rabbit ortholog of DMBT1, with galectin 3, a ß-galactoside-binding lectin, induces a terminal differentiation of epithelial cells. In this paper, we have used surface plasmon resonance (SPR), to analyse the binding of galectin 3 to two purified samples of human DMBT1:recombinant DMBT1 produced in CHO cells and DMBT1 isolated from intestinal tissues. Characterization of their glycosylation profile by nano-ESI-Q-TOF tandem mass spectrometry showed significant differences in O-glycans between the two DMBT1 samples. Results obtained by SPR demonstrated that the oligosaccharide side chains of DMBT1 are recognized by the carbohydrate-recognition domain (CRD) of galectin 3 and modification in the pattern of oligosaccharides modulates the binding parameters of DMBT1 with galectin 3. Moreover, using immunohistochemistry on paraffin-embedded colonic tissue sections, we could show a co-localisation of DMBT1 and galectin 3 in human intestine, suggesting a potential physiological interaction.

Schwannoma of the sinonasal tract: a clinicopathologic and immunohistochemical study of 5 cases.

CONTEXT: Peripheral nerve sheath tumors are soft tissue neoplasms rarely encountered in the nasal cavity and paranasal sinuses. OBJECTIVE: To describe the clinicopathologic and immunohistochemical features of a series of schwannomas of the sinonasal tract. DESIGN: Surgical pathology files were searched for the diagnosis "sinonasal schwannoma." All histologic documents and clinical data were reviewed. Immunohistochemistry was performed on paraffin-embedded tissue with antibodies to S100 protein, epithelial membrane antigen, CD34, and MIB-1. RESULSTS: Five cases of sinonasal schwannoma were retrieved; patients included 3 women and 2 men, aged 20 to 56 years. Three cases were located in the ethmoid sinus. Clinical symptoms were nonspecific (nasal obstruction, epistaxis, and anosmia). All tumors were treated with conservative surgical resection. Pathologic examination showed a spindle cell proliferation without encapsulation in all cases. No cytologic atypia was seen, and the mitotic activity was low (<3 mitotic figures/10 high-power fields). Immunohistochemistry showed diffuse positivity with S100 protein and negativity with CD34 and epithelial membrane antigen. MIB-1 staining was low (1%-5% of tumor cell nuclei stained). During the follow-up (median, 6 years), no recurrence or metastasis was observed. CONCLUSIONS: Schwannoma is a very unusual tumor of the sinonasal tract and is associated with nonspecific symptoms. Histologically, sinonasal schwannomas differ from schwannomas of other locations by their lack of a peripheral capsule and possible ulceration of the epithelial covering. Sinonasal schwannomas are treated with conservative surgical resection and have an excellent prognosis.