Abdominal aortic aneurysm: a review of endoluminal treatment

Abdominal aortic aneurysm (AAA) carries a high mortality if left untreated. Until recently, most patients with AAA were treated with surgical repair. However, endoluminal graft treatment is rapidly becoming an alternative to surgical repair due to lower morbidity and comparable perioperative mortality rates. Despite this optimism patients and operators should keep in mind the palliative nature of these endovascular repairs and the lifelong need for surveillance, before embarking on these procedures. Endoleaks remain to be a significant problem leading to aneurysm expansion and occasionally rupture. Durability of the existing endograft devices remains to be seen. Careful patient selection is critical to success with these procedures. With future advancements in the endograft device technology, methods of patient surveillance, and patient care, there may be a shift from conventional surgical approaches to endovascular repair for the treatment of AAA.     

Humanized anti-CD20 monoclonal antibody (Rituximab) treatment for post-transplant lymphoproliferative disorder

INTRODUCTION: Post-transplant lymphoproliferative disorders (PTLD) is a consequence of Epstein-Barr virus (EBV) infection and is a B-cell hyperplasia with CD-20 positive lymphocytes. The treatment of PTLD includes reduction/withdrawal of immunosuppression and chemotherapy. This study reports our center experience with humanized monoclonal antibody against CD-20 (Rituximab) for the treatment of PTLD. MATERIAL AND METHODS: Eight cases of PTLD after solid organ transplantation [six kidney, one kidney/pancreas (KP) and one liver] occurred between September 1998 and October 2001. The mean time between transplant and the diagnosis of PTLD was 57.3 months (range 3 months to 10 yr). Five patients underwent cadaveric transplant, five males and six were Caucasians with mean age of 48 yr (range 20-67 yr). RESULTS: The clinical presentation was as follows: lymphadenopathy--5, gastrointestinal bleeding--2 and tonsillar enlargement--1. The diagnosis was made by a lymph node biopsy in five, a gastric ulcer biopsy in two and a tonsillar biopsy in one case. Six of them had polymorphous, two had monoclonal B-cell lymphoma, and all were positive for CD-20. Six were related to EBV, documented by latent membrane protein (LMP) or Epstein-Barr encoded RNA (EBER) staining. Immunosuppression at the time of PTLD diagnosis consisted of tacrolimus in six cases and cyclosporine A (CsA) in two with mycophenolate mofetil (MMF) and azathioprine--3 each and sirolimus--1. Rituximab was administered at a dose of 375 mg/m2 once a week for 4 wk. There were no side effects seen with this therapy. Immunosuppression was reduced in all patients. Complete remission was observed in seven cases (one required two courses). One patient who did not respond received chemotherapy. Patients were followed for a mean period of 22.5 months (range 10-45 months post-PTLD diagnosis. At the last follow-up all eight patients were alive, seven with a functioning graft and one on maintenance dialysis. Three of these patients had been in remission for more than 2.5 yr. CONCLUSION: Rituximab is an effective agent in the treatment of PTLD without the morbidity characteristic of chemotherapy. Chemotherapy should be reserved only for those refractory to Rituximab therapy.     

Chronic Active Hepatitis and Pregnancy: A Report of Two Cases in Adolescence

The course and outcome of pregnancy in two adolescents with chronic active hepatitis is described. Pregnancy was uneventful in both patients apart from mild biochemical deterioration in one patient. Both infants are entirely normal. One mother died 4 1/2 months after delivery from primary pulmonary hypertension, an extrahepatic manifestation of her chronic active hepatitis. The second patient is asymptomatic but bas evidence of ongoing liver disease 26 months postdelivery.     

The glycoprotein (mucus) content of tears from normals and dry eye patients

Tears were sampled by two different methods from patients with ocular pemphigoid, Stevens-Johnson's Syndrome and Sjögren's Syndrome, as well as from normals. The tear glycoprotein (mucus) content was determined by measuring hexosamine after hydrolysis. Also hexuronic acid and protein levels were determined, as well as tear flow rate in some instances. The level of glycoprotein (mucus) in tears was markedly reduced in pemphigoid and Stevens-Johnson, diseases which are characterized by early break-up of the tear film and decreased content of mucus-producing conjunctival goblet cells. Mucus has earlier been shown to be necessary for the wetting of epithelium, but it is questionable whether mucus is reduced enough in pemphigoid and Stevens-Johnson to explain tear film instability in these disease entities.     

Prediction of perceptible artifacts in JPEG2000 compressed abdomen CT images using a perceptual image quality metric

RATIONALE AND OBJECTIVES: To test a perceptual quality metric (high-dynamic range visual difference predictor, HDR-VDP) in predicting perceptible artifacts in Joint Photographic Experts Group 2000 compressed thin- and thick-section abdomen computed tomography images. MATERIALS AND METHODS: A total of 120 thin (0.67 mm) and corresponding thick (5 mm) sections were compressed to ratios from 4:1 to 15:1. Peak signal-to-noise ratio (PSNR), HDR-VDP results (paired t-tests), and five radiologists' pooled responses for the presence of artifacts (exact tests for paired proportions) were compared between the thin and thick sections. For three subsets of 120 thin- (subset A), 120 thick- (subset B), and 60 thin- and 60 thick-section compressed images (subset C), receiver operating curve analysis was performed to compare PSNR and HDR-VDP in predicting the radiologists' responses. Using the cutoff values where the sum of sensitivity and specificity was the maximum in subset C, visually lossless thresholds (VLTs) were estimated for the 240 original images and the estimation accuracy was compared (McNemar test). RESULTS: Thin sections showed more artifacts in terms of PSNR, HDR-VDP, and radiologists' responses (p < .0001). HDR-VDP outperformed PSNR for subset C (area under the curve: 0.97 versus 0.93, p = 0.03), whereas they did not differ significantly for subset A or B. Using the cutoff values, PSNR and HDR-VDP predicted the VLT accurately for 124 (51.7%) and 183 (76.3%) images, respectively (p < .0001). CONCLUSIONS: HDR-VDP can predict the perceptible compression artifacts, and therefore can be potentially used to estimate the VLT for such compressions.