flexible-colonoscopy-mice-to-evaluate-severity-colitis-colorectal

Flexible Colonoscopy in Mice to Evaluate the Severity of Colitis and Colorectal Tumors Using a Validated Endoscopic Scoring System

The use of modern endoscopy for research purposes has greatly facilitated our understanding of gastrointestinal pathologies. In particular, experimental ...

Case Western Reserve University School of Medicine, Cleveland

We analyze the evolution of the polarization state of a signal in a recirculating loop with polarization-dependent loss. We show that the polarization-state evolution in experiments is in qualitative agreement with our analysis, and we discuss the relationship between the polarization-state evolution and the Q factor.

Polarization-state evolution in recirculating loops with polarization-dependent loss.

We have investigated the spectral properties of a band rejection filter made with a long-period fiber grating written in photonic crystal fiber that has interstitial air holes. Experiments showed that only one mode was coupled strongly to the fundamental core mode over a 600 nm spectral range. The central wavelength of the filter could be tuned over that range without being appreciably affected by any other mode. By using the multipole method, we found that the interstitial air holes of the photonic crystal fiber played a critical role in limiting the number of modes that could strongly interact with the fundamental mode and in obtaining well-separated resonance peaks. Excellent agreement between theory and experiment was obtained.

Impact of interstitial air holes on a wide-bandwidth rejection filter made from a photonic crystal fiber.

The internal mammary artery (IMA) and the radial artery (RA) are routinely used in coronary artery bypass grafting. However, RA grafts have a higher incidence of postoperative vasospasm and comparatively poor patency rates. The present study was undertaken to investigate the signaling pathways mediating contraction and relaxation in the IMA and RA with the aim of better understanding the mechanism underlying the propensity of RA grafts to spasm.

Thromboxane receptor stimulation suppresses guanylate cyclase-mediated relaxation of radial arteries.

We previously found that higher NADPH levels produced by glucose-6-phosphate dehydrogenase (G6PD) can enhance myocardial superoxide generation by NAD(P)H oxidase in a dog model of dilated cardiomyopathy. Therefore, we tested whether G6PD activity is elevated and enhances NADPH level and increases NAD(P)H oxidase-derived superoxide production in the myocardium from patients with heart failure from ischemic cardiomyopathy.

Upregulation of glucose-6-phosphate dehydrogenase and NAD(P)H oxidase activity increases oxidative stress in failing human heart.

We derive a recursion relation for the frequency autocorrelation function of the polarization dispersion vector for polarization mode dispersion emulators with rotators. The autocorrelation function has a nonzero background for an emulator with a fixed number of sections. This background diminishes slowly as the number of sections grows. Randomizing the section lengths removes the autocorrelation periodicity exhibited by an emulator with equal sections, but it does not remove the finite background.

Autocorrelation function for polarization mode dispersion emulators with rotators.

We calculate the pulse compression in a tapered microstructure optical fiber with four layers of holes. We show that the primary limitation on pulse compression is the loss due to mode leakage. As a fiber's diameter decreases due to the tapering, so does the air-hole diameter, and at a sufficiently small diameter the guided mode loss becomes unacceptably high. For the four-layer geometry we considered, a compression factor of 10 can be achieved by a pulse with an initial FWHM duration of 3 ps in a tapered fiber that is 28 m long. We find that there is little difference in the pulse compression between a linear taper profile and a Gaussian taper profile. More layers of air-holes allows the pitch to decrease considerably before losses become unacceptable, but only a moderate increase in the degree of pulse compression is obtained.

Pulse compression using a tapered microstructure optical fiber.

We determined the differential diagnosis of concomitant pathological conditions in men with overactive bladder symptoms.

Differential diagnosis of overactive bladder in men.

Reports in the literature of high recurrence rates after native tissue repair for pelvic organ prolapse led to the development of alternative techniques, such as those using synthetic mesh. Transvaginal mesh (TVM) delivery systems were implemented in search of better outcomes. Despite reported recurrence as low as 7.1 % after posterior colporrhaphy, mesh kits were developed to correct posterior compartment prolapse. There is a paucity of data to substantiate better results with TVM for rectocele repair. Three randomized controlled trials comparing native tissue repair to synthetic mesh reported posterior compartment outcomes and two of these failed to show a significant difference between groups. Complications of TVM placement are not insignificant and mesh extrusion was reported in up to 16.9 %. Based on currently available data, native tissue repairs have similar outcomes to synthetic mesh without the risks inherent in mesh use and remain the standard of care for the typical patient.

What is the gold standard for posterior vaginal wall prolapse repair: mesh or native tissue?

Prolonged percutaneous SNM testing does not cause infection-related explanation.

Since the introduction of the synthetic midurethral sling, several transvaginal mesh delivery systems have been developed for treating stress incontinence and pelvic organ prolapse. Widespread use of these "kits" has introduced a new dilemma of mesh-specific complications that female pelvic surgeons must manage. Differing treatment techniques have been described and controversy exists as to which method is preferred for vaginal mesh extrusion, mesh perforations, pelvic pain, and dyspareunia. This article addresses the differing management strategies for mesh complications after reconstructive surgery and highlights the available literature on the success of each option.

Article	Year
Polarization-state evolution in recirculating loops with polarization-dependent loss. Optics letters\| PubMed ID: 18033389	2002
Impact of interstitial air holes on a wide-bandwidth rejection filter made from a photonic crystal fiber. Optics letters\| PubMed ID: 16642057	2006
Thromboxane receptor stimulation suppresses guanylate cyclase-mediated relaxation of radial arteries. The Annals of thoracic surgery\| PubMed ID: 16731144	2006
Upregulation of glucose-6-phosphate dehydrogenase and NAD(P)H oxidase activity increases oxidative stress in failing human heart. Journal of cardiac failure\| PubMed ID: 17675065	2007
Autocorrelation function for polarization mode dispersion emulators with rotators. Optics letters\| PubMed ID: 18026390	2002
Pulse compression using a tapered microstructure optical fiber. Optics express\| PubMed ID: 19516549	2006
Differential diagnosis of overactive bladder in men. The Journal of urology\| PubMed ID: 19837417	2009
What is the gold standard for posterior vaginal wall prolapse repair: mesh or native tissue? Current urology reports\| PubMed ID: 22528115	2012
Prolonged percutaneous SNM testing does not cause infection-related explanation. BJU international\| PubMed ID: 22738360	2013
Controversies in the management of mesh-based complications: a urology perspective. The Urologic clinics of North America\| PubMed ID: 22877726	2012

Brian Marks

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