Fluoride-fiber-based side-pump coupler for high-power fiber lasers at 2.8 µm.

A side-pump coupler made of fluoride fibers was fabricated and tested. The tested device had a coupling efficiency of 83% and was driven with an incident pump power of up to 83.5 W, demonstrating high-power operation. Stable laser output of 15 W at a wavelength of around 2.8 µm was achieved over 1 h when using an erbium-doped double-clad fiber as the active medium. To the best of our knowledge, this is the first time a fluoride-glass-fiber-based side-pump coupler has been developed. A test with two devices demonstrated further power scalability.

Two cases of calcified cysts of the spleen.

Presented in this paper are two cases of calcified cyst of the spleen. The first case is an epidermoid cyst of a 20-year-old male who visited our hospital because of vomiting and epigastric discomfort. The second case is a pseudocyst of a 38-year-old male who was referred to our hospital for evaluation of an abdominal mass. Both patients had no history of abdominal trauma. Linear or curvelinear calcification was revealed in the left epigastric region in the plain X-ray films of the abdomen. Ultrasonography, computed tomography and selective celiac angiography led to the diagnosis of a cyst of the spleen, and surgical operations were performed because the cysts were large and symptomatic. Splenic cyst is a relatively rare disease. However, the cases including asymptomatic cases with small cyst have been increasing in number with the improvement of diagnostic methods and the common use of ultrasonography and computed tomography. In Japanese literatures, 332 cases had been reported by 1983.

[The difficulty of distinguishing retroperitoneal schwannoma from liver tumor in the caudate lobe].

A 68-year-old woman was admitted to our hospital for the evaluation of an abdominal tumor. Both ultrasonography and computerized tomography revealed a mass at the caudate lobe of the liver. However, it was difficult to distinguish the mass from a liver tumor in the caudate lobe. The laboratory data showed only a slight elevation of the serum gamma-GTP level and ICG retention. The abdominal arteriography revealed a vascular tumor located in the retroperitoneal space, which was receiving its blood supply from the right inferior phrenic artery. When a laparotomy was performed, a yellowish solid mass (8 X 6 X 4.5 cm) was found behind the lateral segment of the left liver lobe. Histological examination showed interlacing bands of uniform spindle cells of which elongated nuclei were arranged in a palisading pattern. The tumor was diagnosed as schwannoma. Literatures on retroperitoneal schwannoma are reviewed, as this tumor is relatively rare.

[A case of Bartter-like syndrome with abdominal pain, paresis of the extremities and muscle weakness].

A 16-year-old woman was admitted to our hospital because of abdominal pain, paresis of extremities, and muscle weakness. Bartter's syndrome was suspected because of the features of the hypokalemia, hyperaldosteronism, hyperreninemia, increased concentration of plasma angiotensin I & II, the defect in distal fractional reabsorption of chloride and normotension. The concentrations of the plasma angiotensin II and aldosterone, however, were decreased to normal levels after admission probably due to a decrease in the salt intake because of the regular hospital diet. Furthermore, the hyperplasia of the juxtaglomerular apparatus was not found. Therefore, at first we thought we were dealing with another disease, that is pseudo-Bartter's syndrome, which is caused by different pathogenesis. Gill et al. reported that the defect in distal fractional reabsorption of chloride was a characteristic feature in the diagnosis of the Bartter's syndrome. Thus, we tried to explain the clinical symptoms and diagnosis of this case as the Bartter's syndrome according to the theory of Gill et al. If the defect of chloride reabsorption was the only pathogenesis of the Bartter's syndrome, other symptoms seen in our case could be thought of as secondary (or new) changes. Therefore, this case could be differentiated from the pseudo-Bartter's syndrome or the "true" Bartter's syndrome because of the clinical symptoms and the defect in chloride reabsorption.

Letterer-Siwe disease with lipid-containing vacuolated cells--an autopsy case.

A case of Letterer-Siwe disease of a 1-year-2-month-old boy, which clinicopathologically satisfied 7 out of the 8 characteristics of the disease by Siwe's criteria, excluding pathologic changes in the bone is reported. The vacuolated histiocytes appeared in the proliferating reticuloendothelial cells in this case; the cells were positive by general fat reaction; the fats consisted of cholesterol fats, phospholipids and neutral lipid. Electron microscopy showed the occurrence of lipid droplets with cholesterol crystals and atypical form of Langerhans cell granule. Granulomatous changes were found in the lymph nodes and spleen, and this case was also similar in part to chronic granulomatous disease; however, celoid and lipofuscin pigments were negative in the proliferating cells. Cytomegalic inclusion disease as a complication was found in the lungs and intestine, and bilirubin stones in the liver.