Radiofrequency volumetric tissue reduction for treatment of turbinate hypertrophy: a pilot study

BACKGROUND: Apoptosis maintains cell homeostasis. Altered apoptosis is involved in carcinogenesis. It was our aim to investigate whether reflux esophagitis may alter apoptosis in the esophageal mucosa and whether antireflux surgery may restore normal apoptosis. METHODS: Apoptosis was studied preoperatively and postoperatively in esophageal biopsies of 39 patients with various grades of reflux esophagitis and in Barrett's mucosa using the TUNEL method. Biopsies were also taken from lesions of the squamous epithelium adjacent to the Barrett's mucosa. RESULTS: Apoptosis increased with the severity of esophagitis. Apoptosis was low in Barrett's epithelium. Squamous epithelium adjacent to Barrett's mucosa showed increased apoptosis. After surgery apoptosis decreased in squamous epithelium, and it remained low in Barrett's epithelium. CONCLUSIONS: Apoptosis in reflux esophagitis may be protective against increased proliferation. Low apoptosis following antireflux surgery indicates that surgery is effective to prevent reflux-induced cell proliferation. Inhibition of apoptosis in Barrett's may promote carcinogenesis. This may not change following surgery.     

Turbo-coded optical recording channels with DVD minimum mark size

Recent work on turbo codes applied to partial response (PR) optical recording channels has focused on unconstrained channels. In this paper, we consider the application of turbo codes to a (1,7) constrained, PR-equalized optical recording channel with digital versatile disc (DVD) parameters. The addition of a (1,7) run-length-limited (RLL) constraint requires the use of a soft RLL decoder to communicate with the turbo code. Although soft RLL decoders were previously developed for use with iterative decoding, application to a practical optical channel has not been addressed until now. Here, results on both correlated noise and media noise optical recording channel models are given for two PR targets, 1+D and 1+D+D²+D ³. We achieved coding gains of 4 to 6.3 dB over a baseline RLL-coded system. We also evaluated system performance at smaller mark sizes, and found that density gains of 17% and 22% are achievable for the two targets, respectively     

Prostatic cryosurgery: use of MR imaging in evaluation of success and technical modifications

PURPOSE: To evaluate the usefulness of contrast material-enhanced magnetic resonance (MR) imaging in objective assessment of prostatic cryosurgery and the role of MR imaging in the modification of prostatic cryosurgical technique. MATERIALS AND METHODS: Thirty-eight consecutive patients with localized (T1-3, N0, M0) prostatic adenocarcinoma treated with prostatic cryosurgery underwent MR imaging without contrast enhancement before cryosurgery and unenhanced and gadolinium-enhanced MR imaging within 1-3 weeks after cryosurgery. The first 20 patients also underwent MR imaging at 3 months after cryosurgery. MR imaging findings were correlated with those from transrectal ultrasound-directed prostatic staging biopsy. RESULTS: Cryonecrotic prostate was identified as avascular regions characterized by absolute signal void on contrast-enhanced images. With progressive modification of cryosurgical technique, complete cryoablation of the prostate was achieved in the latter nine of the 38 patients. When cryoablation was considered complete according to MR imaging criteria, findings invariably correlated with those at biopsy, with no residual prostate tissue or tumor. CONCLUSION: Gadolinium-enhanced MR imaging of the prostate after cryosurgery provides a highly accurate means of monitoring success. Objective MR imaging findings allow modifications to the technology and technique, resulting in optimal therapeutic results with prostatic cryosurgery.     

Catheter-based radiotherapy to inhibit restenosis after coronary stenting

BACKGROUND: In animal models of coronary restenosis, intracoronary radiotherapy has been shown to reduce the intimal hyperplasia that is a part of restenosis. We studied the safety and efficacy of catheter-based intracoronary gamma radiation plus stenting to reduce coronary restenosis in patients with previous restenosis. METHODS: Patients with restenosis underwent coronary stenting, as required, and balloon dilation and were then randomly assigned to receive catheter-based irradiation with iridium-192 or placebo. Clinical follow-up was performed, with quantitative coronary angiographic and intravascular ultrasonographic measurements at six months. RESULTS: Fifty-five patients were enrolled; 26 were assigned to the iridium-192 group and 29 to the placebo group. Angiographic studies were performed in 53 patients (96 percent) at a mean (+/-SD) of 6.7+/-2.2 months. The mean minimal luminal diameter at follow-up was larger in the iridium-192 group than in the placebo group (2.43+/-0.78 mm vs. 1.85+/-0.89 mm, P=0.02). Late luminal loss was significantly lower in the iridium-192 group than in the placebo group (0.38+/-1.06 mm vs. 1.03+/-0.97 mm, P=0.03). Angiographically identified restenosis (stenosis of 50 percent or more of the luminal diameter at follow-up) occurred in 17 percent of the patients in the iridium-192 group, as compared with 54 percent of those in the placebo group (P= 0.01). There were no apparent complications of the treatment. CONCLUSIONS: In this preliminary, short-term study of patients with previous coronary restenosis, coronary stenting followed by catheter-based intracoronary radiotherapy substantially reduced the rate of subsequent restenosis.     

What Microsoft's identity metasystem means to developers

Every day we use a bevy of identity technologies to prove who we are to various systems, whether we are logging on to a virtual private network or buying from an online store. For users, this means an increasing number of passwords and routines, leading to security fatigue and occasional confusion. For developers, it means working with a hodgepodge of different identity technologies - a situation that doesn't help with maintenance, ongoing security risk analysis, or innovation. Microsoft's proposed answer to this problem is an identity metasystem - a framework that lets varying identity technologies communicate and interoperate using common standards.     

Mutations in purine nucleoside phosphorylase deficiency

PURPOSE: The aim of this study was to investigate the incidence of unexpected malignant uveal melanoma in the age of ultrasound diagnostics and to highlight the reasons for misdiagnosis. PATIENTS AND METHODS: All eyes were surgically removed and histologic examination was performed between 1981 and 1995. The eyes were investigated for the incidence of uveal melanoma, and the history of the unexpected malignant melanoma of the uvea or ciliary body highlighted. RESULTS: 225 (18.7%) eyes with malignant melanoma out of 2583 enucleated eyes were found. Eight (3.6%) of 225 were clinically unexpected. The clinical misdiagnoses were secondary angle closure or open angle glaucoma (6), retinal detachment (5), iritis (1), scleritis (1), cataract (4) and an intraocular mass that was believed to be a metastasis of a colon carcinoma. Seven of eight eyes were blind, and one eye had light perception only. The longest follow up before enucleation was 13 years. On three eyes diagnostic ultrasound was reportedly performed without specific diagnosis of uveal melanoma. Surgery was performed on four eyes for reasons of uncontrollable intraocular pressure or retinal detachment up to five years before enucleation. Histologic diagnoses were 3 epitheloid-type, 2 spindel-type and 3 necrotic melanoma of the uvea. Four eyes showed scleral invasion by tumor cells and one eye an invasion into the episcleral space. CONCLUSIONS: Even today the rate of unexpected uveal melanoma, according to our study is 3.6%. Therefore, all blind eyes without visualisation of the posterior pole should be examined with ultrasound in order to diagnose an uveal melanoma prior to enucleation.