Cuticle network and orientation preference of photonic crystals in the scales of the weevil Lamprocyphus augustus.

This paper reports the structural and optical investigations of the structural colour of the weevil Lamprocyphusaugustus The photonic crystal structure within the weevil's scales was investigated using sequential focused ion-beam milling and scanning electron microscopy imaging. We carefully analysed the reconstructed three-dimensional structure to determine the unit cell of the photonic crystal. It was found that the cuticle network of the cubic unit cell perfectly matches the previously reported diamond-based network. However, different results were obtained for the crystal orientations of the small crystal domains that comprise the entire photonic crystal structure in the scales: <111> directions are highly preferred along the surface normal of the scale. This finding explains the fact that the scale is almost uniformly coloured despite the multi-domain structure. It is confirmed experimentally and theoretically that the wavelength range of the reflection band corresponds to the gap of the photonic band.

Hepatic peribiliary cysts: increases in size and number on computed tomography.

We report a 71-year-old male patient with multiple hepatic peribiliary cysts. The six-year follow-up through computed tomography (CT) imaging revealed increases in the size (from less than 10 mm to more than 38 mm) and number of the cysts.

MR staging of pelvic endometriosis: role of fat-suppression T1-weighted images.

We examined whether MR can determine the stage of endometriosis according to the scoring system established and revised by the American Fertility Society (r-AFS), a system which is widely used by gynecologists. We also studied the utility of fat suppression T1-weighted images in improving accuracy. Seventeen patients with endometriosis examined by conventional MR were included in this study. All the patients had surgically proved stage III or IV disease. We determined the stage by MR using the following criteria according to the r-AFS system: adnexal masses without normal ovarian tissue were considered deep ovarian lesions, while those with normal tissue were considered superficial. A lack of fat between the lesion and surrounding structures was considered a dense adhesion, and hyperintense spots were considered peritoneal implants. The MR scores of patients with and without fat suppression were correlated with the surgical scores. MR staging corresponded to surgical staging in 15 of the 17 patients. In eight patients, peritoneal implants of less than 1.5 cm were depicted only by fat-suppression images. However, these lesions did not change the score significantly. MR imaging could determine the stage in advanced endometriosis. Fat-suppression could highlight smaller implants. These tiny lesions had little clinical meaning in these advanced cases; however, the clinical value of this technique should be evaluated in milder disease.

Hepatobiliary cysts in patients with autosomal dominant polycystic kidney disease: prevalence and CT findings.

OBJECTIVE: Hepatobiliary (intrahepatic and peribiliary) cysts have been described for patients with autosomal dominant polycystic disease. The purpose of this study was to determine the prevalence of these cysts and to describe the wide variation in their appearance on CT scans. MATERIALS AND METHODS: We studied CT scans for 64 patients (31 men and 33 women) who either had known autosomal dominant polycystic kidney disease or had renal cysts and a family member with polycystic kidney disease. Contrast enhancement was used for 31 patients. CT scans were retrospectively evaluated by consensus by two experienced radiologists. The presence, number, and size of hepatobiliary cysts and the presence and appearance of the two variations, peribiliary and intrahepatic cysts, were analyzed. Peribiliary cysts were determined to be present when many small (< or = 10-mm) cysts were seen adjacent to the larger (up to the third order) portal triad. Cysts present in the hepatic parenchyma but not in contact with the larger portal triad were regarded as intrahepatic cysts. RESULTS: CT showed hepatobiliary cysts in 56 of the 64 patients (24 men and 32 women; 88%). Intrahepatic cysts were noted in all 56 patients; peribiliary cysts were definitely seen on CT scans for 22 patients and were probably seen (fewer than five cysts and/or cysts located only on one side of the portal vein) on CT scans for 19 patients (73% of all patients with hepatobiliary cysts). Peribiliary cysts appeared as discrete cysts in 31 patients, as a string of cysts in six patients, and as a tubular structure in four patients. Intrahepatic cysts generally were round but occasionally were polygonal. They were variable in number, size, and location. CONCLUSION: Hepatobiliary cysts were noted in 56 of 64 patients (intrahepatic cysts in all cases and peribiliary cysts in 73% of positive cases). Intrahepatic cysts varied widely in number, size, and location, whereas peribiliary cysts were small and appeared as discrete cysts, a string of cysts, or a tubular structure adjacent to the larger portal triad. It is important to be aware of the wide variety of findings for hepatobiliary cysts so that they are not confused with other abnormalities.

Hepatic peribiliary cysts: multiple tiny cysts within the larger portal tract, hepatic hilum, or both.

PURPOSE: To describe characteristic imaging features of hepatic peribiliary cysts. MATERIALS AND METHODS: Four patients with hepatic cysts in which the radiologic (n = 3) or histologic (n = 1) findings were consistent with peribiliary cysts of the liver (multiple small cysts seen exclusively in the larger portal tract, hepatic hilum, or both at gross examination and dilatations of extramural peribiliary gland at histologic examination) underwent computed tomography (CT) and ultrasound (US). In three patients, CT was performed after drip infusion of cholangiographic contrast material. RESULTS: Contrast material-enhanced CT clearly depicted many tiny cysts along the larger portal veins up to the third- or fourth-order branch (n = 3). US depicted multiple cysts in the echogenic portal tract definitely (n = 2) or equivocally (n = 2). On cholangiographic contrast-enhanced CT scans, cystic areas were located adjacent to or surrounding the bile ducts, and the possibility of biliary dilatation, communication, or both was disproved. CONCLUSION: Hepatic peribiliary cysts can be diagnosed with US and enhanced CT, especially with CT performed after administration of cholangiographic contrast material.

Metastatic tumors in irregular fatty liver mimicking focal sparing.

Two cases of hepatic metastatic tumor occurring in irregular fatty liver are reported. These metastatic tumors appeared as irregularly shaped hyperdense areas and were difficult to distinguish from focally spared areas of irregular fatty liver. Even if areas of focal sparing are irregular in shape, hepatic tumors should be carefully ruled out in patients at high risk for liver tumors.

Correlation between MR signal intensity and histologic findings in neurinomas and meningiomas of the brain.

The signal intensity of magnetic resonance imaging (MRI) was compared with the histologic findings in 20 cases of neurinoma and 18 cases of meningioma. The apparatus was a Hitachi G-10 unit (0.15 T). The pulse sequences were SR (500/32), SE (1200/60), IR (1400/400). The intensity of tumor signal, as compared with that of normal white matter signal, was divided into 9 grades. In neurinomas, the signal intensity appeared markedly low with IR and markedly high with SE sequence in the Antoni B type, while it was slightly low with IR and minimally to markedly high with SE sequence in the Antoni A type, and intermediate between Antoni A type and B type in the mixed type. In meningiomas, it appeared moderately to slightly low with IR and slightly to moderately high with SE sequence in the meningotheliomatous type, minimally low with IR and minimally to slightly high with SE sequence in the fibrous type, and intermediate as compared with the above two in the transitional type. The angiomatous type was characterized by a low intensity on SR and IR images and an iso to high intensity on SE images, while the psammomatous type showed a low intensity with all of the sequences used. We clarified that the signal intensity on MRI varied among different histologic types of neurinoma or meningioma, and correlated differences in the intensity of signals on MRI to that of histologic characteristics, such as size and shape of cells, intercellular material, intracellular biologic polymers, area of membrane surface, blood flow and calcified matter.

Reaction of nucleic acids bases and their derivatives with peroxodisulfate ion.

Reaction with peroxodisulfate ion was investigated, that is, reaction of 1,3-dimethyluracil, 1,3-dimethylthymine, and caffeine with carbon radicals formed from decarboxylation of carboxylic acids, oxidation of the methyl group at 5-position of thymines, and halogenation of nucleic acids bases and their derivatives with alkali halides.