Malignant mesothelioma metastatic to the oral region and latest topics (Review).

Malignant mesothelioma (MM) is a rare neoplasm with poor prognosis that usually develops after exposure to asbestos, and is characterised by aggressive local invasion and metastatic spread. While metastasis to the oral cavity is very rare, a total of 23 cases of MM metastasising to the oral cavity were identifed. Among those, the tongue was the most common site of metastasis (39.1%), and frequently involved the epithelioid MM cell type. Recent studies have elucidated the mechanisms underlying the development of MM. Chronic inflammation has been implicated in promoting MM growth and was shown to play a key role by driving the release of high mobility group box protein 1 following asbestos deposition. Inherited heterozygous germline mutations in the deubiquitylase BRCA-associated protein 1 were shown to increase the incidence of MM in some families. Infection by the simian virus 40 was also found to be associated with the occurrence of MM. Moreover, the increasing incidence rates of MM, together with its propensity to metastasise to the oral cavity, indicate that clinicians and pathologists should be highly aware of this disease. Furthermore, identification of novel serum biomarkers would enable better screening and treatment of MM, and improve the survival outcomes.

Curcumin inhibits epithelial-mesenchymal transition in oral cancer cells via c-Met blockade.

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer. OSCC cells are highly invasive, a characteristic that involves epithelial-mesenchymal transition (EMT); the conversion of immotile epithelial cells into motile mesenchymal cells. EMT is involved in the progression of various types of cancer by promoting tumour cell scattering and conferring to these cells cancer stem cell (CSC)-like characteristics, such as self-renewal. Hepatocyte growth factor (HGF) signalling plays an important role in EMT induction and, therefore, contributes to cell invasion and metastasis in cancer. Due to its potential chemopreventative and anti-tumour activities, curcumin has attracted much interest and has been shown to act as a potent EMT inhibitor in various types of cancer. However, at present, the potential effects of curcumin on HGF-induced EMT in OSCC have not been investigated. Here, we demonstrated that HGF signalling could induce EMT in the HSC4 and Ca9-22 OSCC cell lines via the HGF receptor c-Met and downstream activation of the pro-survival ERK pathway. Notably, curcumin inhibited HGF-induced EMT and cell motility in HSC-4 and Ca9-22 cells via c-Met blockade. Therefore, these findings establish curcumin as a candidate drug for OSCC treatment. Furthermore, curcumin was able to effectively inhibit the HGF-induced increase in the levels of vimentin by downregulating the expression of phosphorylated c-Met, an ERK. In conclusion, the results of the present study demonstrated that curcumin was able to reverse HGF-induced EMT, possibly by inhibiting c-Met expression in oral cancer cells, providing a strong basis for the development of novel approaches for the treatment of oral cancer.

Cubic crystal protein inclusions in the neodermis of the pancreatic fluke, Eurytrema pancreaticum, and Eurytrema coelomaticum.

Light microscopy of Eurytrema pancreaticum and Eurytrema coelomaticum collected from cattle in Japan, China, Thailand, and Brazil showed many cubic crystal inclusions in the neodermis (tegument) of all flukes. The crystal inclusions were histochemically positive for protein. Scanning electron microscopy showed many cubic protrusions containing cubic crystal protein inclusions on the surface of the neodermis. Transmission electron microscopy showed that cubic crystal protein inclusions appeared in the perikarya of subtegumental parts, passed through the cytoplasmic bridge, moved into the syncytial neodermal cytoplasm, and then protruded from, and finally separated from, the neodermal cytoplasm. Cubic crystal protein inclusions were hexahedral with each side 2-18 microm long. High-resolution microscopy of ultrathin sections of crystal inclusions showed a lattice fringe at spacings of about 0.52 nm by using a filtering processing. Diffractograms were obtained by Fourier transform of the images. The lattice structure of the crystal protein inclusions was shown by inverse Fourier transform, indicating that the cubic crystal protein inclusions were single crystals. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis estimated the molecular weight of protein in the cubic crystal inclusion as 36.6 kDa. Energy-dispersive X-ray spectroscopy proved that the cubic crystal protein inclusions were composed of protein and sulfur.

Pulmonary complications of cystic echinococcosis in children in Uruguay.

Cystic echinococcal lesions surgically removed from 99 patients aged 1-15 years in Uruguay were histopathologically studied. The lesions were collected from the lungs, liver, peritoneum, omentum, pleura, ovary, appendix and perinephrium. All intact cysts were well-developed and unilocular. Pulmonary and hepatic fertile cysts in which protoscoleces were produced were in 75% and 47%, respectively, of all patients. Fertile cysts having many protoscoleces were in the lungs of a 1-year-old infant. Sixteen ruptured pulmonary cysts were found in the lungs of 13 patients and four ruptured hepatic cysts were found in the liver of three patients. Pulmonary complications were seen in patients having pulmonary echinococcal cysts. In lung tissue surrounding echinococcal cysts, pulmonary complications included chronic congestion, hemorrhage, bronchopneumonia, as well as interstitial pneumonia that included histological changes caused by bronchiolitis, organizing pneumonia and obstructive pneumonia. Liver tissue adjacent to echinococcal cysts showed atrophy of hepatic cells, proliferation of interstices, small focal hemorrhages, and infiltration of mononuclear cells. The present study shows that a close relationship exists between pulmonary echinococcosis and pneumonia. The term 'echinococcal pneumonia' is proposed for pneumonia accompanying pulmonary echinococcosis.

Testicular sparganosis in a child from Uruguay.

A patient 9 years old had a painless tumor in the left testicle. The left testicle measured about 5 cm long and about 3 cm wide and was stony hard in part. From an echographic image, the patient was diagnosed to have a hematoma in the left testicle. The left testicle was surgically removed. From histological observations, burrows were surrounded by numerous eosinophils in the testicle, epididymis and tunica vaginalis. Cross sections of spargana were in the burrows. Severe granulomatous orchitis and epididymitis were around the burrows. This case was the second one of human sparganosis in Uruguay.

Immunohistochemical observations on cellular response in unilocular hydatid lesions and lymph nodes of cattle.

As we believe the immunohistochemistry of the hydatid lesions and draining lymph nodes has never been studied, we collected them from the liver and lungs of cattle in Uruguay for such a study. Frozen sections of the tissues were immunohistochemically stained using monoclonal antibodies against surface markers CD2, CD4, CD5, CD8, B cell and granulocyte-monocyte/macrophage and antiserum against specific granules of bovine eosinophils. The adventitial layer of the cyst wall consists of a layer of epithelioid cells and connective tissue. The cells from the epithelioid cell layer were a kind of macrophage. In most cases having progressive hydatid cysts, CD8+ cells were predominant in the pericystic adventitia, and a relatively small number of CD4+ cells were in the same area. In the adventitial layer surrounding the regressive and involutional hydatid cysts, infiltrating lymphocytes were composed mostly of CD4+ cells. An eosinophil-mediated destruction of the laminated layer was recognized in the regressive and involuted hydatid cysts. The subpopulations of T cells in the local lymph nodes tended to be similar to T cells in the adventitial layer of hydatid lesions. From our findings, we consider that infiltration of eosinophils and the subpopulations of lymphocytes infiltrating the hydatid lesions in the liver and lungs are derived from cells in the draining lymph nodes of both organs.

Subcutaneous infection of Lagochilascaris minor in domestic cats from Uruguay.

The nematode Lagochilascaris minor was collected from subcutaneous abscesses on the face and neck of three female cats aged 8 months, and 1 and 2 years. These cats were born in the Department of Maldonado, Uruguay. Female and male nematodes were 10.1-14.4 and 10.0-14.3mm long, respectively. The lips were one dorsal lip and two subventral lips separated from the body by a deep post-labial groove, and were separated from each other by triangular interlabial projections. The width of the lips was almost equal to the width of the post-labial collar. The vulva was near the middle of the female body. The eggs were oval or spherical and measured 0.059-0.073 mm long and 0.045-0.065 mm wide. Irregular-shaped pits were on the egg surface; 20-32 pits were around the equator of the eggs. The male posterior region was ventrally curved. Each spicule was about three quarters of the ejaculator duct length. From these findings, the nematodes were identified as L. minor. We believe this is the first report of its infection in Uruguay.