An extremely compact all-fiber-optic scanning endomicroscopy system was developed for twophoton fluorescence (TPF) and second harmonic generation (SHG) imaging of biological samples. A conventional double-clad fiber (DCF) was employed in the endomicroscope for single-mode femtosecond pulse delivery, multimode nonlinear optical signals collection and fast two-dimensional scanning. A single photonic bandgap fiber (PBF) with negative group velocity dispersion at twophoton excitation wavelength (i.e. ~810 nm) was used for pulse prechirping in replacement of a bulky grating/lens-based pulse stretcher. The combined use of DCF and PBF in the endomicroscopy system made the endomicroscope basically a plug-and-play unit. The excellent imaging ability of the extremely compact all-fiber-optic nonlinear optical endomicroscopy system was demonstrated by SHG imaging of rat tail tendon and depth-resolved TPF imaging of epithelial tissues stained with acridine orange. The preliminary results suggested the promising potential of this extremely compact all-fiber-optic endomicroscopy system for real-time assessment of both epithelial and stromal structures in luminal organs.

We report on a new optics design for an optical coherence tomography (OCT) balloon imaging catheter. The design involves a miniature compound gradient-index (GRIN) rod lens, which consists of a fiber optic mode-field reducer and relay rod lenses to achieve predictable high lateral resolution at a desired large working distance. The compound lens design significantly simplifies the engineering process for an OCT catheter and enables 3-D full circumferential cross sectional imaging of large luminal organs such as human esophagus. An as-designed OCT catheter is developed and demonstrated for real-time in vivo swine esophagus imaging in a 3-D spiral fashion. Keywordsoptical coherence tomography; endomicroscopy; balloon catheter; internal organ imaging Optical coherence tomography (OCT) is a rapidly evolving noninvasive imaging technology that provides high-resolution cross sectional images of tissue microanatomy. 1 While initially applied to eye imaging, the development of miniature fiber optic catheters/endoscopes has enabled high-resolution OCT imaging of internal luminal organs in vivo. Most of the OCT catheters developed so far have a small diameter (e.g., ∼1 to 2 mm), a high lateral resolution (e.g., 15 to 40 µm), and a short working distance (e.g., 1 to 4 mm). 2-6 These catheters are well suited for imaging small lumens or for imaging only a small sector of large lumens when the probes are in direct contact with the tissue surface. The short working distance unfortunately precludes full circumferential imaging of large luminal organs such as human esophagus (which has a diameter of ∼ 18 to 25 mm when the natural esophageal folds are flattened e.g., by balloon inflation). There is an increasing clinical need for systematic imaging assessment of the entire esophagus for Barrett's esophagus surveillance and early cancer detection, 7,8 inspiring strong interest in developing a new type of OCT catheter-a balloon imaging catheter, which basically integrates a miniature OCT imaging probe within the inner lumen of a doublelumen balloon catheter with the balloon (when inflated) to flatten the natural folds of the esophagus. The concept of such an OCT balloon imaging catheter was introduced in 2000 and was recently demonstrated for imaging the entire esophagus. 9,10 A major challenge with the OCT imaging probe is achieving a small focused spot size (i.e., high transverse resolution) at a large working distance (e.g., 9 to 12 mm) while keeping the optical components small (e.g., NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript of a diameter 1 to 2 mm), so that the imaging probe would be able to pass through a small inner balloon tubing and shaft, while the entire balloon catheter can be delivered into the esophagus through a 2.8-to 3.4-mm accessory port of a standard gastrointestinal (GI) endoscope. The systematic OCT imaging of the entire esophagus can then be integrated with a routine endoscopy procedure.We present a new optics design for the OCT balloon imaging catheter. Different fr...

IntroductionIntra-abdominal hypertension (IAH) is known as a common, serious complication in critically ill patients. Bacterial translocation and permeability changes are considered the pathophysiological bases for IAH-induced enterogenic endotoxemia and subsequent multiorgan failure. Nevertheless, the effects of slightly elevated intra-abdominal pressures (IAPs) on the intestinal mucosa and the associated mechanisms remain unclear.MethodsTo investigate the acute effects of different nitrogen pneumoperitoneum grades on colonic mucosa, male Sprague-Dawley rats were assigned to six groups with different IAPs (0 [control], 4, 8, 12, 16, and 20 mmHg, n = 6/group). During 90 min of exposure, we dynamically monitored the heart rate and noninvasive hemodynamic parameters. After gradual decompression, arterial blood gas analyses were conducted. Thereafter, structural injuries to the colonic mucosa were identified using light microscopy. Colon permeability was determined using the expression of tight junction proteins, combined with fluorescein isothiocyanate dextran (FD-4) absorption. The pro-oxidant-antioxidant balance was determined based on the levels of malondialdehyde (MDA) and antioxidant enzymes.ResultsIAH significantly affected the histological scores of the colonic mucosa, tight junction protein expression, mucosal permeability, and pro-oxidant-antioxidant balance. Interestingly, elevations of IAP that were lower than the threshold for IAH also showed a similar, undesirable effect. In the 8 mmHg group, mild hyponatremia, hypocalcemia, and hypoxemia occurred, accompanied by reduced blood and abdominal perfusion pressures. Mild microscopic inflammatory infiltration and increased MDA levels were also detected. Moreover, an 8-mm Hg IAP markedly inhibited the expression of tight junction proteins, although no significant differences in FD-4 permeability were observed between the 0- and 8-mmHg groups.ConclusionsAcute exposure to slightly elevated IAP may result in adverse effects on intestinal permeability and the pro-oxidant-antioxidant balance. Therefore, in patients with critical illnesses, IAP should be dynamically monitored and corrected, as soon as possible, to prevent intestinal mucosal injury and subsequent gut-derived sepsis.

AIM:To investigate the efficacy and safety of ulinastatin for patients with acute lung injury (ALI) and those with acute respiratory distress syndrome (ARDS). METHODS:A systematic review of randomized controlled trials (RCTs) of ulinastatin for ALI/ARDS was conducted. Oxygenation index, mortality rate [intensive care unit (ICU) mortality rate, 28-d mortality rate] and length of ICU stay were compared between ulinastatin group and conventional therapy group. Meta-analysis was performed by using Rev Man 5.1. RESULTS:Twenty-nine RCTs with 1726 participants were totally included, the basic conditions of which were similar. No studies discussed adverse effect. Oxygenation index was reported in twenty-six studies (1552 patients). Ulinastatin had a significant effect in improving oxygenation [standard mean difference (SMD) = CONCLUSION: Ulinastatin seems to be effective for ALI and ARDS though most trials included were of poor quality and no information on safety was provided.© 2014 Baishideng Publishing Group Co., Limited. All rights reserved.Key words: Ulinastatin; Acute lung injury; Acute respiratory distress syndrome; Mortality; Oxygenation indexCore tip: Currently, many studies highlight the advantages of ulinastatin in lung protection, which is likely because acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) share a common pathogenesis with sepsis. We tried to provide more specific evidence on this practice by performing a meta-analysis. In our study (29 clinical trials included), we found that though all the studies were of low quality, ulinastatin might improve oxygenation and mortality and be truly effective in patients with ALI/ARDS.

Intra-abdominal hypertension (IAH) is a common and serious complication in critically ill patients for which there is no well-defined treatment strategy. Here, we explored the effect of IAH on multiple intestinal barriers and discussed whether the alteration in microflora provides clues to guide the rational therapeutic treatment of intestinal barriers during IAH. Using a rat model, we analysed the expression of tight junction proteins (TJs), mucins, chemotactic factors, and Toll-like receptor 4 (TLR4) by immunohistochemistry. We also analysed the microflora populations using 16S rRNA sequencing. We found that, in addition to enhanced permeability, acute IAH (20 mmHg for 90 min) resulted in significant disturbances to mucosal barriers. Dysbiosis of the intestinal microbiota was also induced, as represented by decreased Firmicutes (relative abundance), increased Proteobacteria and migration of Bacteroidetes from the colon to the jejunum. At the genus level, Lactobacillus species and Peptostreptococcaceae incertae sedis were decreased, whereas levels of lactococci remained unchanged. Our findings outline the characteristics of IAH-induced barrier changes, indicating that intestinal barriers might be treated to alleviate IAH, and the microflora may be an especially relevant target.