Primary osteosarcoma of the skull

Primary osteogenic sarcoma of the skull is an exceedingly rare condition. An adult male patient is described, who had a painless swelling in the right forehead that had rapidly enlarged in the previous 6 months. Radiological investigations showed a large destructive mass lesion involving the right side of the frontal bone with extension into the frontal sinus, causing marked extradural compression of brain parenchyma. Histopathological examination confirmed the lesion to be primary osteogenic sarcoma.     

Expression of differential nitric oxide synthase isoforms in human normal gastric mucosa and gastric cancer tissue

The present study investigated the expression and distribution of three isoforms of nitric oxide synthase (NOS) in different anatomical regions of the human stomach and in gastric neoplastic tissues by immunohistochemistry using specific antibodies. Intracellular localization of individual isoenzymes of NOS was detected in normal gastric mucosa. Gastric cancer tissues had a marked reduction of all three NOS isoforms expression. The expression of the endothelial NOS, neuronal NOS and inducible NOS in the tumor tissue was significantly lower than in normal gastric mucosa (P = 0.01, P = 0.02, P < 0.01, respectively). In the tumor tissue the expression of inducible NOS was significantly lower than the expression of both constitutive forms of NOS (P < 0.01). There was a tendency to higher expression of both constitutive forms of NOS in earlier stages T2 of the tumor compared to advanced T4 tumor. In contrast, the expression of inducible NOS was higher than in the advanced T4 tumor than in the earlier stages T2 of the tumor. The mapping of the expression of endothelial NOS, neuronal NOS and inducible NOS in human stomach showed higher expression of NOS isoforms in the distal third than in the proximal third of the stomach (P = 0.03, P = 0.04, P = 0.01, respectively). We conclude that there is greater expression of NOS in the stomach corpus and in antrum than in the proximal third of the normal human stomach mirroring the anatomical predilection of common pathological changes in this part of the human stomach. Furthermore, there was loss of the expression of individual isoenzymes in gastric neoplasms.      

Methylene blue reverts multidrug resistance: sensitivity of multidrug resistant cells to this dye and its photodynamic action

Photodynamic action has been advocated as an alternative treatment of tumors but the most common used dyes, hematoporphyrin derivatives, are substrate for P-glycoprotein. This study investigated the MDR-reverting properties of methylene blue (MB) and compared the sensitivity to its photodynamic action (PDA) in five cell lines that either express or do not express the MDR phenotype. MB was able to revert the MDR phenotype and there was no difference in sensitivity to MB-PDA between MDR and non-MDR cells, suggesting that MB has the advantage of being used simultaneously as a MDR reverser and a photodynamic agent.     

Interferon alpha-2B and liver resection to treat multifocal hepatic epithelioid hemangioendothelioma: a relevant approach to avoid liver transplantation

BACKGROUND: Hepatic epithelioid hemangioendothelioma is a rare malignant tumor of vascular origin with frequent multifocal appearance. Liver resection may cause tumor spread. Liver transplantation has been indicated for unresectable nodules. We hypothesized that adjuvant interferon treatment is effective to prevent metastasis after liver resection. We report a case of multifocal hepatic epithelioid hemangioendothelioma successfully treated with interferon pulse therapy and bilobar hepatic resection. METHODOLOGY: CT scan and magnetic resonance imaging diagnosed three nodules in the liver (segments IV, VI and VII). Histopathology and specific immunostaining of a percutaneous nodule biopsy confirmed the diagnosis of hepatic epithelioid hemangioendothelioma. The treatment protocol included daily interferon alpha 2b 9 weeks before and 1 week after resection of liver segments IV, VI and VII. RESULTS: The postoperative outcome was complicated by a self-limited biliary fistula. The patient remains tumor free at 3 years after liver resection and currently enjoys excellent health. CONCLUSION: Interferon pulse therapy and hepatic resection was a good option to treat multifocal bilobar hepatic epithelioid hemangioendothelioma; it may prevent metastasis dissemination.     

Investigation of red blood cell antigens with highly fluorescent and stable semiconductor quantum dots

We report a new methodology for red blood cell antigen expression determination by a simple labeling procedure employing luminescent semiconductor quantum dots. Highly luminescent and stable core shell cadmium sulfide/cadmium hydroxide colloidal particles are obtained, with a predominant size of 9 nm. The core-shell quantum dots are functionalized with glutaraldehyde and conjugated to a monoclonal anti-A antibody to target antigen-A in red blood cell membranes. Erythrocyte samples of blood groups A+, A2+, and O+ are used for this purpose. Confocal microscopy images show that after 30 min of conjugation time, type A+ and A2+ erythrocytes present bright emission, whereas the O+ group cells show no emission. Fluorescence intensity maps show different antigen expressions for the distinct erythrocyte types. The results obtained strongly suggest that this simple labeling procedure may be employed as an efficient tool to investigate quantitatively the distribution and expression of antigens in red blood cell membranes.