New method of measuring presampling MTF by fourier transform of square-wave chart image

We developed an easy method of measuring the presampling modulation transfer function (MTF) using the square wave chart in digital radiography. In this method, the presampling MTF is measured by Fourier transform of image data of the square wave chart. When Fourier analysis of the sampling data of a square wave is carried out, it is generally difficult to find the starting point and terminal point of the periodic data that should be extracted because of an insufficient number of data. To solve this problem, interpolated data were calculated by using a window function of the frequency domain. The aliasing error was avoided using a characteristic such that the square wave has discrete frequency components. The accuracy of this method was investigated by computer simulation study. Actual measurement of the presampling MTF by this method was also performed with a CR system. These studies indicated the effectiveness of our proposed method in terms of accuracy and ease of use.     

Right ventricular systolic and diastolic function at rest in patients with coronary artery disease. Assessment with equilibrium radionuclide ventriculography

Right ventricular systolic and diastolic function was studied in patients with ischemic heart disease using equilibrium radionuclide ventriculography. In patients with inferior myocardial infarction and proximal right coronary lesions, the right ventricular ejection fraction (0.43 +/- 0.06, n = 10, mean +/- SD) and peak filling rate (1.7 +/- 0.4 EDV/sec) were lower than normals (0.57 +/- 0.07 and 2.7 +/- 0.4 EDV/sec, n = 10, p less than 0.001, respectively). In these patients, the right ventricular time to peak filling rate was longer than in normals (225 +/- 36 msec vs 136 +/- 45 msec, p less than 0.001), while the left ventricular ejection fraction remained normal. In patients with inferior myocardial infarction and distal right coronary lesions, the right ventricular ejection fraction, peak filling rate and time to peak filling rate were not different from those in normals. Even in patients with proximal right coronary lesions, the right ventricular ejection fraction was normal unless they had an inferior myocardial infarction. A decreased left ventricular ejection fraction and abnormal motion of the ventricular septum did not affect the right ventricular ejection fraction. The present results suggest that patients with an inferior myocardial infarction and proximal right coronary lesion often develop right ventricular systolic and diastolic dysfunction.     

Adult transmesenteric hernia: report of two cases

Transmesenteric hernia is a rare cause of bowel obstruction in adults. We herein describe two cases that occurred in adult women, ages 27 and 19. Both cases presented with abdominal pain without muscular defense signs. Computed tomography of both cases showed features of small bowel obstruction by an internal hernia. A laparotomy showed mesenteric defects of the mesentery of the ileum in the former case and the mesentery of the transverse colon in the latter case, with a herniating ileum. The involved small bowel was viable in both cases, and the bowel was pulled out of the mesenteric defect without resection. The mesenteric defects were then successfully repaired.     

Recurrent mediastinal desmoid tumor treated by surgical resection ; report of a case

We report a rare case of mediastinal desmoid tumor in a 17-year-old man. The patient was a 17-year old man who had underwent surgery for mediastinal tumor at our hospital 2 years before. The tumor was diagnosed as a solitary fibrous tumor of the mediastinum. After 2 years, chest computed tomography(CT) and magnetic resonance imaging( MRI) showed a mass at the previously resected site. Surgery was performed again under the diagnosis of recurrent tumor. The tumor densely adhered to the superior vena cava, right innominate vein, pericardium, and the right lung. The tumor was completely resected with the aid of the partial extracorporeal circulation. Finally, both previously resected tumor and the recurrent tumor were diagnosed pathologically as desmoid tumors.     

Huge inflammatory pseudotumor of the spleen with postoperative portal vein thrombosis: report of a case

We report the rare case of a splenic inflammatory pseudotumor associated with massive splenomegaly, diagnosed after surgery. A 51-year-old woman was admitted to our hospital for investigation of anemia. Physical examination revealed a palpable left upper quadrant mass. Computed tomography and magnetic resonance imaging showed a splenic mass, 20 cm in diameter. We performed splenectomy for both diagnosis and treatment. The spleen weighed 2400 g, and histologic examination of the mass confirmed an inflammatory pseudotumor. Portal vein thrombosis (PVT) developed the day after surgery, but resolved with anticoagulation therapy. This case highlights that there is a risk of PVT after splenectomy in patients with massive splenomegaly, and that anticoagulant therapy should be initiated promptly.     

Significance of low-level DSA detected by solid-phase assay in association with acute and chronic antibody-mediated rejection

We sought to clarify the controversial issue of whether detecting low‐level anti‐donor‐specific HLA antibody (HLA‐DSA) by single‐antigen flow‐bead assay (SAFB) may have a potential role in reducing acute and chronic antibody‐mediated rejection (AMR). We retrospectively studied the preoperative serum of ABO‐compatible living kidney transplantation recipients transplanted between 2001 and 2004 by SAFB using a Luminex platform. HLA‐DSA was detected only by SAFB in 24 patients, although all of them showed negative T‐cell and B‐cell complement‐dependent cytotoxicity (CDC) crossmatches. The HLA‐DSA patients went on to have surprisingly high levels of acute and chronic AMR despite being only weakly sensitized (acute AMR, 33.3%; chronic AMR, 41.7%). After 2005, we implemented SAFB routinely and any patient having a positive HLA‐DSA was considered to be a desensitization candidate. The 52 patients found to have HLA‐DSA underwent kidney transplantation after prior treatment with a single dose of rituximab (RIT) and three or four sessions of double‐filtration plasmapheresis (DFPP) in addition to regimens commonly used between 2001 and 2004. After 2005, there was a significant reduction in the occurrence of acute and chronic AMR (acute AMR, 4.7%, P < 0.001; chronic AMR, 4.7%, P < 0.001). The 5‐year graft survival rate also improved after implementing SAFB (83.3–98.1%, P = 0.032). The RIT/DFPP‐induction protocol may improve graft survival even in patients with low‐level DSA.     

A model to evaluate toxic factors influencing islets during collagenase digestion: the role of serine protease inhibitor in the protection of islets

The recovery of all of the islets contained in a pancreas is the goal of islet isolation for transplantation. This study reveals an environment that injures the isolated islets during digestion and proposes a new model for optimal islet isolation. Islets were isolated from Wistar rat pancreases by stationary collagenase digestion while the digestion time was varied at 15, 30, 60, and 120 min. The digested pancreas and islets were analyzed histologically and adenosine nucleotides were measured. Overnight cultured islets (40 islets) were cocultured for 30 min with the supernatants obtained from pancreatic collagenase digestion at different digestion periods in order to assess the toxic environment. The peak yields of islets were obtained at 30 min of digestion. The histological study of digested pancreas showed that the exocrine cells lost their cellular integrity at 120 min of digestion, but the islet cells were left intact. Accordingly, the ATP levels of the pancreatic tissue decreased during the digestion period. The coculture experiment demonstrated that the islets cultured with the supernatants from the collagenase digestion showed digestion time-dependent disruption of the cellular integrity of islets in accordance with a rapid decrease of ATP levels in the islets. The addition of serine protease inhibitors into this coculture clearly showed protection of islets, which maintained high ATP levels in association with intact membrane integrity as assessed by AO/PI staining. Morphological deterioration of islets as well as a marked ATP decrease was evident in the entire digested pancreas as well as in islets cocultured in the supernatants from the collagenase digestion. Various factors toxic to the islets can therefore be analyzed in future experiments using this coculture model for obtaining a good yield of viable islets.     

Intraductal oncocytic papillary neoplasm of the extrahepatic bile duct: report of a case

We report a rare case of an intraductal oncocytic papillary neoplasm (IOPN) of the extrahepatic bile duct. A 66-year-old man was admitted to our hospital for investigation of right-sided back pain. Ultrasonography, computed tomography and magnetic resonance imaging showed a papillary lesion, 3?cm in diameter, in the middle bile duct, invaginating into the cystic duct. We made a provisional diagnosis of middle bile duct cancer and performed substomach-preserving pancreatoduodenectomy. Macroscopically, the middle bile duct contained a two-humped papillary tumor, one tip of which invaginated into the cystic duct. Microscopically, the tumor consisted of cuboidal cells with abundant eosinophilic cytoplasm resembling that of oncocytes and a fine fibrovascular core. The tumor cells were stained strongly with antimitochondria antibody. Based on these findings, the tumor was diagnosed histologically as IOPN of the extrahepatic bile duct. The patient died of prostate cancer 51?months after surgery, but without evidence of recurrence of the IOPN.     

Use of candesartan cilexetil decreases proteinuria in renal transplant patients with chronic allograft dysfunction

BACKGROUND: Posttransplant proteinuria and hypertension are difficult to treat after renal transplantation. Therefore, we examined whether candesartan cilexetil is effective in reducing urinary protein excretion or in controlling hypertension in patients with renal allograft dysfunction. METHODS: Sixty-two renal transplant recipients with proteinuria were enrolled in this study. They underwent kidney transplantation under cyclosporine or tacrolimus immunosuppression between February 1983 and December 1998. Causes of proteinuria were chronic rejection in 28, glomerulonephritis in 16, cyclosporine or tacrolimus nephrotoxicity in 9, and unknown in 9 recipients. The dose of candesartan cilexetil ranged from 4 to 12 mg/day. Eleven patients with proteinuria who had not been treated with candesartan cilexetil constituted a matched control population. RESULTS: Hypertension was well controlled by administration of candesartan cilexetil. Both systolic blood pressure and diastolic blood pressure significantly decreased from 141.7+/-14.8 mm Hg to 118.7+/-11.9 mm Hg and 121.2+/-11.6 mm Hg, and from 89.0+/-13.0 mm Hg to 72.0+/-10.4 mm Hg and 74.9+/-9.4 mm Hg, at 2 months and 1 year after administration, respectively. Urinary protein excretion was reduced from 0.93+/-1.2 g/day to 0.34+/-0.7 g/day and 0.43+/-1.2 g/day at 2 months and 1 year after administration, respectively. The levels of creatinine clearance were 55.7+/-28.9 mL/min before treatment, 50.9+/-24.8 mL/min at 2 months, and 52.6+/-24.8 mL/min at 1 year after treatment, respectively. There was no clinically significant difference between them. Regarding the calcineurin inhibitor levels, there was no significant difference between the levels before and 1 year after treatment. There was a significant difference in all examinations (systolic blood pressure, diastolic blood pressure, proteinuria, and renal function) between the patients with and without candesartan at 1 year after treatment. No significant adverse effects occurred. CONCLUSIONS: Candesartan cilexetil can effectively control hypertension and proteinuria without deterioration in renal allograft function. These data suggest that treatment with candesartan cilexetil may be useful for maintaining long-term renal allograft function.