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Doped silica glass fibers analyzed for luminescence and other related characteristics. The results showed that dominant transitions found in the lowest excited level were step-by-step nonradiative relaxations. Intermediate radiative transmissions were observed to supply only limited amounts of energy.In addition, increased fiber length was seen to lengthen emission decay times.

Using a percutaneous transhepatic cholangioscopy (PTCS) catheter, sphincter of Oddi motility was measured in a patient with papillary stenosis secondary to bile duct stones. Prior to sphincterotomy, intramuscular injection of 20 micrograms caerulein did not inhibit pathological contraction waves of the sphincter of Oddi or relieve abdominal pain. Endoscopic sphincterotomy of the lower segment of the sphincter of Oddi resulted in recovery of the normal response to caerulein, i.e. relaxation of the sphincter of Oddi. This observation indicates that the pathological contraction and lack of relaxation to cholecystokinin in a patient with papillary stenosis is due to high common bile duct pressure. The measurement of motility of sphincter of Oddi via the PTCS route is useful in diagnosing motor disorders in the sphincter of Oddi and is helpful in deciding to perform endoscopic sphincterotomy. [ABSTRACT FROM AUTHOR]

Since July 1975, percutaneous transhepatic biliary drainage (PTBD) has been performed in 533 cases, and since April 1977 we have developed percutaneous transhepatic cholangioscopy (PTCS) as a diagnostic and therapeutic endoscopical tool in 198 cases of malignant disease and 195 benign cases. After dilating the sinus tract of PTBD using a 15-Fr catheter about 2 weeks after PTBD, PTCS was carried out through the sinus tract. PTCS has diagnostic advantages: the lesion can be accurately diagnosed histologically and the extent of cancer in the biliary tract can be assessed by taking biopsy specimens before the operation. PTCS has been applied for cholangioscopic lithotripsy in 145 cases of gallstone disease. In 44 cases, the Nd-YAG laser and/or electrohydraulic shock wave has been used to break up the stones. The PTCS morbidity was 6% and mortality was 0.3%. [ABSTRACT FROM AUTHOR]

A multicenter, randomized, prospective trial was conducted to determine the clinical efficacy of ticlopidine, an antiplatelet agent, in the prevention of graft occlusion following vascular reconstructive surgery of the lower extremity for arteriosclerosis obliterans. Ticlopidine was administered for two years to one group of patients (112 reconstructed arterial segments) while a control group received no antithrombotic therapy (108 segments). There was no significant difference between the treated and control groups in the overall cumulative patency rates for both suprainguinal and infrainguinal reconstructions. In the treated group, however, there was a significant reduction of occlusions in pa tients with rest pain or ischemic gangrene (p < 0.1) and in those with hyperlipi demia (p < 0.05). Ticlopidine-treated patients with infrainguinal arterial reconstructions developed more occlusions than controls between three and twelve months after surgery, but the controls had more occlusions both immedi ately after surgery and in the second postoperative year. It appeared, therefore, that ticlopidine reduced graft failure due to neointimal fibrous hyperplasia or progression of the underlying condition but caused an adverse effect by delaying graft healing. The clinical usefulness of antiplatelet therapy is limited, but it may be effective in the prevention of graft occlusion when administered to the selected patient groups above mentioned. Controversy about antiplatelet ther apy and future research on adjuvant drug therapy after arterial reconstruction are discussed. [ABSTRACT FROM PUBLISHER]

Describes the improvements in infrared upconversion devices generating blue and green light emission. Criteria for optimizing the upconversion efficiency of visible emission; Influence of the processes of visible emission generation; Effect of the size of luminescent material on conversion efficiency.