No abstract

No abstract

Small gastrointestinal stromal tumors (GISTs) (< 3 cm) occasionally are found in the stomach during endoscopy. There is no consensus about the surgical management of these small tumors, although this clinical issue is crucial because some of the tumors show unexpected malignant behavior. In this study, we evaluated the clinical management of patients with gastric GISTs who underwent surgical resection. Altogether, 31 patients with gastric GISTs were examined retrospectively. Surgical resection was fundamentally indicated for the patients with gastric GISTs suspected to be malignant by endoscopy or endoscopic ultrasonography (EUS). The malignant grade of the GISTs was evaluated by the mitotic rate, tumor size, and MIB-1 index. EUS was useful for differentiating benign from malignant GISTs; but by limiting the study to patients with small tumors (< 3 cm), the diagnostic value of EUS was not satisfactory for defining the surgical indication. Tumors that were < 50 mm were successfully treated by laparoscopic surgery. Of the 31 patients, 4 had a relapse of the disease, and 1 of those 4 patients had a small tumor (30 mm). All of the recurrences were classified in the high risk category. Surgery is indicated for gastric GISTs that are > or = 20 mm or are suspected to be malignant based on EUS findings. Laparoscopic resection is feasible and is recommended as the treatment of choice for patients with tumors < 50 mm. Risk assessment can be most useful for predicting recurrence.

Pyrroles fused with aromatic rings (isoindole derivatives) have been readily prepared by the reaction of aromatic nitro compounds with ethyl isocyanoacetate in the presence of DBU. The ease of this reaction depends on the aromaticity of the starting nitro aromatics. Polycyclic aromatic nitro compounds such as 1-nitroacenaphthylene or 9-nitrophenanthrene are more reactive than simple nitro aromatics such as nitrobenzene or nitronaphthalenes and give the corresponding pyrroles in good yields. Pyrroles prepared by this method have been converted into porphyrins fused with various aromatic rings by the reduction with LiAlH, followed by treatment with an acid catalyst and oxidation with chloranil or oxygen. Tetra-lY2-naphthoporphyrin has been prepared by the reaction of 2-nitro-3,4dihydronaphthalene or 1-nitronaphthalene with ethyl isocyanoacetate followed by reduction, tetramerization and oxidation. Thus, highly conjugated porphyrins are readily prepared starting from aromatic nitro compounds, and their electronic and optical properties can be controlled by choice of the starting aromatic nitro compound.

No abstract