Difunctionalization of Alkenes Using 1-Chloro-1,2-benziodoxol-3-(1H)-one.

Difunctionalization of alkenes with 1-chloro-1,2-benziodoxol-3-(1H)-one (1) was investigated. Various additional nucleophiles were tested, and oxychlorination, dichlorination, azidochlorination, chlorothiocyanation, and iodoesterfication were demonstrated. The oxychlorination product was obtained efficiently when the reaction was operated in water. Dichlorination occurred in the presence of a Lewis basic promoter, such as 4-phenylpyridine N-oxide, as an additive. The reaction with in situ-generated azido anion afforded azidochlorinated compounds with a chlorine atom at the terminal position, while the reaction with trimethylsilyl isothiocyanate produced chlorothiocyanation adducts with a chlorine atom at the benzylic position. On the other hand, when 1 was treated with tetra-n-butylammonium iodide prior to the addition of alkenes, only iodoesterification occurred selectively. These mild reactions enable convenient site-selective difunctionalizations of substrates having two alkene moieties. NMR experiments suggested that the electrophilic reactive species in each reaction varied depending on the nature of the added nucleophile.

Monochrome versus color softcopy displays for teleradiology: observer performance and visual search efficiency.

This study evaluated the potential clinical utility for teleradiology of a high-performance (3-mega-pixel) color softcopy display compared with two monochrome softcopy displays: one of comparable luminance (250 cd/m2) and one of higher luminance (450 cd/m2). Six radiologists viewed 50 chest images, half with nodules and half without, once on each display. Eye position was recorded on a subset of the images to characterize visual search efficiency. There was no statistically significant difference in diagnostic performance as a function of monitor (F=1.176, p=0.3127), although the higher luminance display yielded slightly better performance. In terms of total viewing time, there were no statistically significant differences between the three monitors (F=1.478, p=0.2298). The dwell times associated with true- and false-positive decisions were shortest for the high luminance monochrome display, longer for the low luminance monochrome, and longest for the low luminance color display. Dwells for the false-negative decisions were longest for the high luminance monochrome display, shorter for the low luminance monochrome, and shortest for the low luminance color display. The true negative dwells were not significantly different. The study suggests that high-performance color displays can be used for teleradiologic interpretation of diagnostic images without negatively impacting diagnostic accuracy or visual search efficiency to a significant degree.

[A case of pleural malignant lymphoma associated with chronic tuberculous pyothorax].

We report a case of pleural malignant lymphoma associated with chronic tuberculous pyothorax. A 67-year-old male was hospitalized because of left lateral chest swelling and pain. He had suffered from pulmonary tuberculosis at the age of six and tuberculous pleurisy at the age of 24. We made a histologic diagnosis of malignant lymphoma diffuse large B-cell type. He was medicated THP-COP (THP, CY, VCR, PSL) therapy and his chest pain and swelling has improved gradually. From the view point of molecular biology, we detected Epstein-Barr virus (EBV) infection in the pyothorax wall. In conclusion, we should be more careful about medical examination in patients with EBV positive tuberculous pyothorax considering the complication of malignant lymphoma.

[A case of pulmonary arteriovenous malformation treated by transcatheter embolization using coils].

The patient was a 21-year-old woman who, at 16 years old, had had no subjective symptoms. She was referred to our hospital because of abnormal shadows in the middle of the left lung that were seen on a chest radiograph during a school medical screening. In her first examination at our hospital, CT revealed tumor-like shadows with diameters of 2.0 cm in Lt-S6 and 0.5 cm in Rt-S5, together with arteries and veins. Lung ventilation and blood flow scintigraphy was used to obtain images of both kidneys and the head, and as a result, a pulmonary arteriovenous malformation (PAVM) was diagnosed. Because of a low shunt fraction of 10.8%, the patient was only kept under observation. However, at 21 years of age, she complained of dyspnea with exercise and was admitted to the hospital for further examination. Chest CT showed an increase in the diameter of the arteriovenous malformation (AVM) to 2.7 cm, and 3-D image reconstruction clearly revealed the position of the tumor in relation to the pulmonary artery and vein. The shunt fraction had increased to 18.3%. Coil embolization was therefore performed to A6b, the artery feeding the AVM (using interlocking detachable coils of 6 mm-10 cm and 8 mm-20 cm, and Trufill coils of two 7 mm-6 cm and 5 mm-4 cm). The patient had no serious postoperative complications. A decreased AVM diameter of 1.7 cm and an improved shunt fraction of 11% were observed, and she was discharged from the hospital. Since then, she has been well, without dyspnea, and her chest films show only coils and no aggravation of other AVMs. AVMs generally have no symptoms, but they can cause severe complications such as hypoxia from a right-to-left shunt, hemoptysis, hemothorax, and brain abscesses. Coil embolization should be considered more often for the treatment of AVM because it is safer, more effective and less invasive than traditional operations.