High-Sensitivity 2D MoS2/1D MWCNT Hybrid Dimensional Heterostructure Photodetector.

A photodetector based on a hybrid dimensional heterostructure of laterally aligned multiwall carbon nanotubes (MWCNTs) and multilayered MoS2 was prepared using the micro-nano fixed-point transfer technique. Thanks to the high mobility of carbon nanotubes and the efficient interband absorption of MoS2, broadband detection from visible to near-infrared (520-1060 nm) was achieved. The test results demonstrate that the MWCNT-MoS2 heterostructure-based photodetector device exhibits an exceptional responsivity, detectivity, and external quantum efficiency. Specifically, the device demonstrated a responsivity of 3.67 × 103 A/W (λ = 520 nm, Vds = 1 V) and 718 A/W (λ = 1060 nm, Vds = 1 V). Moreover, the detectivity (D*) of the device was found to be 1.2 × 1010 Jones (λ = 520 nm) and 1.5 × 109 Jones (λ = 1060 nm), respectively. The device also demonstrated external quantum efficiency (EQE) values of approximately 8.77 × 105% (λ = 520 nm) and 8.41 × 104% (λ = 1060 nm). This work achieves visible and infrared detection based on mixed-dimensional heterostructures and provides a new option for optoelectronic devices based on low-dimensional materials.

Therapeutic effects of internal fixation with support plates and cannulated screws via the posterolateral approach on supination external rotation stage IV ankle fracture.

OBJECTIVE: To evaluate the therapeutic effects of internal fixation with support plates and cannulated screws via the posterolateral approach on supination external rotation stage IV ankle fracture. METHODS: Eighty-five patients with SER-IV° ankle fracture and large posterior malleolar fracture treated from June 2016 to June 2018 in our hospital, were randomly divided into a support plate group (n=47) and a cannulated screw group (n=38). The treatment outcomes were compared regarding surgical time, amount of bleeding, time of fracture healing, postoperative complications, as well as the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score and excellent rate one year later. RESULTS: The surgical time and intraoperative blood loss of cannulated screw group were significantly lower than those of support plate group (P<0.05). There were four cases of posterior lateral incision redness complicated with obvious bloody exudation in support plate group on the postoperative 2nd day. One case developed into superficial incision infection subsequently, and one case suffered from deep infection. After dressing and treatment with sensitive antibiotics, stitch removal was delayed, and primary healing was obtained. In cannulated screw group, there were two cases of posterior lateral incision redness complicated with obvious bloody exudation on the postoperative 3rd day, without skin incision infection. One case had cannulated screw loosening two months after surgery, and the posterior malleolar fracture block was slightly displaced. The incidence of surgical complications in support plate and cannulated screw groups were 8.51% and 7.89%, respectively (P>0.05). The AOFAS scores of cannulated screw ((81.71 ± 12.39) points) and support plate groups ((86.62 ± 10.12) points) were significantly different (P<0.05). CONCLUSION: For patients with posterior malleolar fracture or osteoporosis, fixation using support plate is recommended. Cannulated screw fixation is suitable for for patients with poor conditions of skin soft tissues or basic diseases such as diabetes intolerant to long surgery.

LncRNA ANCR is positively correlated with transforming growth factor-ß1 in patients with osteoarthritis.

Transforming growth factor-ß (TGF-ß) signaling plays pivotal roles in the pathogenesis of osteoarthritis, while TGF-ß signaling in certain diseases models is regulated by the long noncoding RNA (lncRNA) antidifferentiation noncoding RNA (ANCR). Therefore, ANCR may also participate in osteoarthritis. In this study, the expression of ANCR and TGF-ß1 in the plasma of osteoarthritis patients and healthy controls was detected by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The diagnostic value of ANCR for osteoarthritis was evaluated by receiver operating characteristic receiver operating characteristic (ROC) curve analysis. The correlation between the plasma levels of ANCR and TGF-ß1 was analyzed by the Pearson correlation coefficient. The ANCR expression vector was transfected into cells of the human chondrocyte cell line CHON-001 (ATCC CRL-2846), and the effect on TGF-ß1 expression and cell proliferation was detected by Western blot and cell counting kit-8 assay, respectively. We observed that the plasma levels of ANCR were significantly lower, while the plasma levels of TGF-ß1 were significantly higher in osteoarthritis patients than those in healthy controls. Downregulation of ANCR effectively distinguished osteoarthritis patients from healthy controls. ANCR and TGF-ß1 expression was negatively correlated in osteoarthritis patients but not in healthy controls. ANCR overexpression promoted the proliferation of chondrocytes and inhibited TGF-ß1 expression. We concluded that ANCR might participate in osteoarthritis by downregulating TGF-ß1 and promote the proliferation of chondrocytes.

General Control Nonderepressible 2 (GCN2) Kinase Inhibits Target of Rapamycin Complex 1 in Response to Amino Acid Starvation in Saccharomyces cerevisiae.

In eukaryotic cells, two conserved protein kinases, Gcn2 and TOR complex 1 (TORC1), couple amino acid conditions to protein translation. Gcn2 functions as an amino acid sensor and is activated by uncharged tRNAs that accumulate when intracellular amino acids are limited. Activated Gcn2 phosphorylates and inhibits eukaryotic initiation factor-2α (eIF2α), resulting in repression of general protein synthesis. Like Gcn2, TORC1 is also involved in sensing amino acid conditions. However, the underlying mechanism remains unclear. In the present study, we show that TORC1 is a direct target of Gcn2 kinase in the yeast Saccharomyces cerevisiae In response to amino acid starvation, Gcn2 binds to TORC1 and phosphorylates Kog1, the unique regulatory subunit of TORC1, resulting in down-regulation of TORC1 kinase activity. In the absence of Gcn2, TORC1 signaling activity increases and becomes unresponsive to amino acid starvation. Our findings demonstrate that TORC1 is an effector of Gcn2 in amino acid signaling, hence defining a novel mechanism by which TORC1 senses amino acid starvation.

Effects of Taylor Spatial Frame on tumors and tumor-like lesions with pathological fractures of lower extremities.

OBJECTIVE: We aimed to evaluate the clinical effects of Taylor spatial frame (TSF) on tumors and tumor-like lesions complicated with pathological fractures of the lower extremities. METHODS: Eighty-two patients admitted from September 2013 to January 2015 were selected. Forty-two cases were included in Group-A to receive TSF fixation and forty were included in Group-B to receive locking plate fixation. The surgical time, intraoperative blood loss, postoperative healing rate of primary incision, incidence rate of complications, hospitalization stay length, and fracture healing time as well as rate of excellent and good Enneking scores one year after surgery were compared. RESULTS: The intraoperative blood losses of Group-A and Group-B were (150.0±6.5) ml and (201.9±7.4) ml respectively (P<0.05). The surgical times were (77.3±8.9) minutes and (96.5±5.9) minutes respectively (P<0.05). The postoperative rates of complications in the two groups (4.76% vs. 10.00%) were similar (P>0.05). The primary incision healing rates of Group-A and Group-B were 97.62% and 82.50% respectively. The hospitalization stays were (15.7±0.9) days and (15.2±0.7) days respectively (P>0.05). The fracture healing times were (30.1±2.1) weeks and (32.4±2.2) weeks respectively (P<0.05). The rate of excellent and good Enneking scores one year after surgery was 97.61% in Group-A and 95.00% in Group-B (P>0.05). CONCLUSIONS: Tumors and tumor-like lesions complicated with pathological fractures of the lower extremities can be effectively treated by TSF.

Tumor Suppressor Folliculin Regulates mTORC1 through Primary Cilia.

Folliculin (FLCN) is the tumor suppressor associated with Birt-Hogg-Dubé (BHD) syndrome that predisposes patients to incident of hamartomas and cysts in multiple organs. Its inactivation causes deregulation in the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway. However, the underlying mechanism is poorly defined. In this study, we show that FLCN is a ciliary protein that functions through primary cilia to regulate mTORC1. In response to flow stress, FLCN associates with LKB1 and recruits the kinase to primary cilia for activation of AMPK resided at basal bodies, which causes mTORC1 down-regulation. In cells depleted of FLCN, LKB1 fails to accumulate in primary cilia and AMPK at the basal bodies remains inactive, thus nullifying the inhibitory effect of flow stress on mTORC1 activity. Our results demonstrate that FLCN is part of a flow sensory mechanism that regulates mTORC1 through primary cilia.

Ubiquitin regulates TORC1 in yeast Saccharomyces cerevisiae.

In the yeast Saccharomyces cerevisiae the TOR complex 1 (TORC1) controls many growth-related cellular processes and is essential for cell growth and proliferation. Macrolide antibiotic rapamycin, in complex with a cytosol protein named FKBP12, specifically inhibits TORC1, causing growth arrest. The FKBP12-rapamycin complex interferes with TORC1 function by binding to the FRB domain of the TOR proteins. In an attempt to understand the role of the FRB domain in TOR function, we identified a single point mutation (Tor2(W2041R) ) in the FRB domain of Tor2 that renders yeast cells rapamycin resistant and temperature sensitive. At the permissive temperature, the Tor2 mutant protein is partially defective for binding with Kog1 and TORC1 is impaired for membrane association. At the restrictive temperature, Kog1 but not the Tor2 mutant protein, is rapidly degraded. Overexpression of ubiquitin stabilizes Kog1 and suppresses the growth defect associated with the tor2 mutant at the nonpremissive temperature. We find that ubiquitin binds non-covalently to Kog1, prevents Kog1 from degradation and stabilizes TORC1. Our data reveal a unique role for ubiquitin in regulation of TORC1 and suggest that Kog1 requires association with the Tor proteins for stabilization.

Hemiarthroplasty versus internal fixation in super-aged patients with undisplaced femoral neck fractures: a 5-year follow-up of randomized controlled trial.

INTRODUCTION: There were higher rates of revision, complication, non-union, delayed union, and poorer functional outcomes reported in super-aged patients of undisplaced femoral neck fractures treated with internal fixation. Therefore, we designed this randomized comparative study aiming to compare the effectiveness and long-term follow-up results of hemiarthroplasty (HA) with that of multiple cannulated screws (MCS). MATERIALS AND METHODS: Eligible participants were randomly assigned into two groups for different methods of operation (hemiarthroplasty group and internal fixation group). The related indexes and data of two groups were collected for comparative analysis during the average follow-up period of 38.68 ± 28.24 months. RESULTS: There were only two patients performed reoperation in HA group, and the reoperation rate of HA group (5.41%, 2/37) was significantly lower than that of IF group (21.4%, 9/41) (P value = 0.000). The comparison of survival curves for reoperation showed significant differences between two groups (P value = 0.031).The results of Cox proportional hazards model suggested that only operation method significantly affected the occurrence of reoperation (P value = 0.049). The results of survival analysis showed that there was no significant difference in survival time between two groups (P value = 0.682). And in the Cox proportional hazards model, only age significantly affected the occurrence of death (P value = 0.000). The average Harris scores of two groups were all above 75 points, and there was no significant difference in Harris scores between the two groups (P value greater than 0.05). But in the early term follow-up, the excellent and good rate of hip joint function in HA group was significantly higher than that in IF group (P value less than 0.05). CONCLUSIONS: Hemiarthroplasty with less postoperative complications, low reoperation rate and better function recovery in early stage provide a good choice for the treatment of super-aged patients with nondisplaced femoral neck fracture.

CCN1 enhances angiogenic potency of bone marrow transplantation in a rat model of hindlimb ischemia.

Implantation of autologous bone marrow mononuclear cells (BM-MNCs) has been performed in ischemic tissues, for stimulation of angiogenesis, but the limited number of BM-MNCs in patients with hindlimb ischemia disease may offset their overall therapeutic efficacy. CCN1 is a novel and essential regulator during angiogenesis. We evaluated whether CCN1 and BM-MNC are capable of promoting angiogenesis in hindlimb ischemia. In this study, we created the rat model of hindlimb ischemia, and then the rats were randomly divided into four groups: CCN1 infusion plus BM-MNC transplantation (CCN1 + BM-MNCs group), CCN1 infusion plus PBS injection (CCN1 group), vehicle infusion plus BM-MNC transplantation (BM-MNCs group) and vehicle infusion plus PBS injection (control group). The combination of CCN1 and BM-MNC therapy could increase blood perfusion, capillary/muscle fiber ratio and tissue oxygenation in ischemic hindlimb. Moreover, CCN1 could not only inhibit the apoptosis of BM-MNCs, but also enhance the adhesiveness of BM-MNCs to HUVEC. Taken together, CCN1 enhanced angiogenesis of BM-MNC transplantation, and combining CCN1 with BM-MNC transplantation is a useful alternative for ischemic limbs.

[Analyses of risk factors for deep vein thrombosis in lower extremities].

OBJECTIVE: To explore the risk factors of deep vein thrombosis (DVT) in lower extremities. METHODS: Retrospective data analyses were performed for a total of 1264 DVT patients at our department from January 2010 to December 2012. RESULTS: Among them, 984 cases (77.85%) were over 40 years old, no overt cause was found for 642 cases (50.79%), 142 cases (11.23%) had a clear history of trauma before onset (without surgery). Among 316 recurrent postoperative cases, there were the surgical histories of orthopedics (n = 142, 11.23%), gynecology (n = 90, 7.12%), general practice (n = 42, 3.32%), vascular (n = 23, 1.82%), urological (n = 12, 0.94%) and others (n = 7, 0.55%). Ten cases (0.79%) occurred after suffering bedridden chronic diseases. And 20 cases (1.58%) were caused by conditions during pregnancy or postpartum period.had Malignant tumors were found in 25 (1.98%) patients. After long-term uses of hormones, 10 patients (0.79%) of rheumatoid arthritis had a recurrence.Owing to varicose veins, 27 patients (2.14%) recurred. Eight patients (0.63%) had a history of drug abuse, 2 cases (0.16%) suffered depression and 62 cases (4.9%) were recurrent. CONCLUSION: There are many causative factors of DVT so that prevention is of great importance. We should pay more attention to the prevention and treatment of high-risk DVT patients.

[Endovascular therapy for traumatic arterial injury].

OBJECTIVE: To explore the clinical efficacies of endovascular therapy for traumatic arterial intima injury, arterial pseudoaneurysm and arteriovenous fistula. METHODS: From October 2009 to December 2011, 24 patients of arterial intima injury, arterial pseudoaneurysm and arteriovenous fistula underwent endovascular therapy including embolism and stent implantation, etc. RESULTS: Among them, 14 patients were punctured directly and another 10 were punctured after the exposure of arteries. The interventions included embolism (n = 3), embolism plus covered stent implantation (n = 2), covered stent implantation (n = 12) and bare stent implantation (n = 7). And the surgical success rate was 100%. After endoluminal treatment, arterial blood flow recovered, arterial pseudoaneurysm shrank, local pain relieved and venous blood pressure decreased. CONCLUSION: As an effective therapy for traumatic arterial intima injury, arterial pseudoaneurysm and arteriovenous fistula, endovascular therapy has minimal trauma, fewer complications and satisfactory outcomes.

1-Year Outcomes of a Multicenter Randomized Controlled Trial of the Ankura II Thoracic Endoprosthesis for the Endovascular Treatment of Stanford Type B Aortic Dissections.

Background: The Ankura II Thoracic Stent Graft System (Lifetech, Shenzhen, China) is an evolution of the Ankura stent graft. This study reports one-year outcomes of the Ankura II Thoracic Stent Graft System for endovascular treatment of Stanford type B aortic dissections. Methods: The Ankura II Thoracic Aortic Endovascular Trial was a randomized, single-blinded, clinical trial conducted at 12 Chinese institutes. The enrolled patients diagnosed with Stanford type B aortic dissections (TBADs) were randomly assigned to the Ankura group or Ankura II group. Standard follow-up examinations were performed at 1, 6, and 12 months. Safety and efficacy data were analyzed. Results: 132 patients with TBADs were enrolled. The outcomes for the primary safety end points revealed that the Ankura II stent graft was statistically non-inferior compared to the Ankura stent graft. The 1-month device-related major adverse events (1.6 vs. 0%; p = 0.48), 1-month all-cause mortality (1.7 vs. 4.5%; p = 0.621), 12-month survival rate (95.2 ± 2.7% vs. 94.1 ± 2.9%; p = 0.769), and major adverse event (MAE) rate (5.1 vs. 4.7% at 1 month; p = 0.73 and 5.8 vs. 8.9% at 12 months; p = 0.718) of Ankura II group are all comparable to Ankura group. The two groups showed similar primary effectiveness and true lumen expansion effect, and false lumen remodeling was improved in Ankura II group (-100.0 vs. -48.5%; p = 0.08). Conclusions: The one-year outcomes from this prospective, randomized, multicenter study demonstrate that Ankura II stent graft shows comparable results to Ankura for treating TBADs, resulting in low mortality rates, MAEs and reintervention rates. Clinical Trial Registration: ChiCTR-TRC-12002844.

[Clinical treatment of application of deep venous thrombosis by retrievable vena cava filter].

OBJECTIVE: To summarize the clinical experiences of treating deep venous thrombosis (DVT) with retrievable vena cava filter. METHODS: A total of 180 patients with DVT in unilateral lower extremity were recruited. There were 82 males and 98 females with an average age of 46 years old. After the diagnosis of vascular color Doppler ultrasound, retrievable vena cava filter was implanted through contralateral femoral vein. Simultaneously another 114 patients underwent femoral vein embolectomy. All cases received the post-operative therapies of anticoagulation, thrombolysis and vasodilation. RESULTS: The implantation of retrievable vena cava filter was successful in all cases. Among 142 cases of attempted extraction, 116 filters were extracted successfully at Days 12 - 24. The success rate was 81.69%. Filters captured thrombosis in 34 cases (29.31%). CONCLUSION: As a safe and efficacious method, the implantation of retrievable vena cava filter prevents the occurrence of pulmonary embolism in the patients with DVT in unilateral lower extremity. Its timely extraction may avoid the long-term complications.

3D in vivo optical coherence tomography based on a low-voltage, large-scan-range 2D MEMS mirror.

3D in vivo optical imaging on a mouse has been obtained using a 2D MEMS mirror for lateral scanning in a time-domain optical coherence tomography (OCT) system. The MEMS mirror aperture size is 1 x 1 mm(2), and the device footprint is 2 x 2 mm(2). The MEMS mirror scans +/- 30 degrees optical angles about both x and y-axis at only 5.5V DC voltage. An endoscopic probe with an outer diameter of 5.8 mm has been designed, manufactured and packaged. The probe scans an average transverse area of 2 mm x 2 mm. The imaging speed of the probe is about 2.5 frames per second, limited by the speed of the employed optical delay line.

Nobiletin suppresses IL-21/IL-21 receptor-mediated inflammatory response in MH7A fibroblast-like synoviocytes (FLS): An implication in rheumatoid arthritis.

The mechanisms driving the development and progression of Rheumatoid arthritis (RA) are complex, novel targeted therapies are gaining traction as potential methods to prevent or slow the progression of RA. Nobiletin is a derivative of citrus fruit that has been shown to attenuate the development of osteoarthritis and inhibit the expression of proinflammatory cytokines. However, the exact mechanisms by which nobiletin exerts these chondroprotective effects remain poorly understood. In the present study, we investigated the impact of nobiletin in mediating the effects of interleukin-21 (IL-21) in MH7A fibroblast-like synoviocytes (FLS), the main cell type found in the articular synovium. Firstly, we demonstrate that nobiletin (25 µM and 50 µM) reduced the expression of the IL-21 receptor by 29% and 51%, respectively, in FLS. Additionally, our findings demonstrate that nobiletin potently ameliorated IL-21-induced increased production of reactive oxygen species and 4-hydroxynonenal, increased expression of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and high-mobility group box 1 (HMGB1), and decreased mitochondrial membrane potential. We also demonstrate the ability of nobiletin to attenuate IL-21-induced expression of matrix metalloproteinases 3 and 13 (MMP-3, MMP-13), key degradative enzymes involved in RA-associated cartilage destruction. Finally, we show that the effects of nobiletin are mediated through the JAK1/STAT3 pathway, as nobiletin significantly reduced the phosphorylation of both JAK1 and STAT3. Taken together, our findings indicate that nobiletin may offer a safe and effective treatment against the development and progression of RA induced by the expression of IL-21 and its receptor.

Gradient-index lens rod based probe for office-based optical coherence tomography of the human larynx.

Optical coherence tomography (OCT) is an evolving noninvasive imaging modality that has been used to image the human larynx during surgical endoscopy. The design of a long gradient-index lens-based probe capable of capturing images of the human larynx by use of spectral domain OCT during a typical office-based laryngoscopy examination is presented. An optical-ballast-based 4f optical relay system is proposed to realize variable working distance with a constant optical delay. In-vivo OCT imaging of the human larynx is demonstrated. Office-based OCT is a promising imaging modality for early laryngeal cancer diagnosis.

In vivo diagnosis of oral dysplasia and malignancy using optical coherence tomography: preliminary studies in 50 patients.

BACKGROUND: In vivo, non-invasive optical coherence tomography (OCT) permits high-resolution imaging of tissue surfaces and subsurfaces, with the potential capability for detection and mapping of epithelial pathologies. PURPOSE: To evaluate the clinical capability of non-invasive in vivo OCT for diagnosing oral dysplasia and malignancy. EXPERIMENTAL DESIGN: In 50 patients with oral lesions, conventional clinical examination was followed by OCT imaging, then standard biopsy and histopathology. Two blinded, pre-standardized investigators separately diagnosed each lesion based on (1) OCT and (2) histopathology. RESULTS: Intra- and inter-observer agreement between diagnoses based on histopathology and imaging data was excellent, with lambda values between 0.844 and 0.896. Sensitivity and specificity were also very good. CONCLUSIONS: These data demonstrate the excellent capability of in vivo OCT for detecting and diagnosing oral premalignancy and malignancy in human subjects.

Prussian blue analogue-derived Ni and Co bimetallic oxide nanoplate arrays block-built from porous and hollow nanocubes for the efficient oxygen evolution reaction.

Effective oxygen evolution reaction (OER) catalysts composed of Earth-abundant transition metals are crucial for sustainable energy conversion and storage. Metal-organic frameworks (MOFs) with tunable compositions are promising precursors for the fabrication of hollow and porous electrocatalysts. However, pulverous MOFs usually suffer from agglomeration during pyrolysis, greatly reducing the activity of their derived catalysts. In this work, Prussian blue analogue (PBA) arrays with hierarchical multidimensional architecture were directly grown on nickel foam (NF) using a template-oriented method. The subsequent calcination in air allowed for obtaining NixCo3-xO4 nanoplate arrays consisting of porous and hollow nanocubes. The derived bimetallic NixCo3-xO4/NF required only an overpotential of 287 mV to achieve a current density of 10 mA cm-2 in 1.0 M KOH solution, which is much lower than that of the monometallic NiO and the RuO2 benchmark. The 3D intersectional architecture of the NixCo3-xO4 nanoplates and the porous and hollow nanocube subunits contributed to the large specific surface area and reduced charge-transfer resistance of the NixCo3-xO4/NF electrode. Density functional theory (DFT) calculations and post-OER characterization revealed that the incorporated Co was the active sites and electrochemical active CoOOH intermediates were in situ formed during the OER. Our study provides a facile and efficient strategy for the rational design of MOF-derived materials towards effective and low-cost electrocatalysis.

Topographical variations in the polarization sensitivity of articular cartilage as determined by polarization-sensitive optical coherence tomography and polarized light microscopy.

To understand the influence of topographical variations in collagen fibril orientation of articular cartilage on optical phase images of polarization-sensitive optical coherence tomography (PS-OCT), we use polarized light microscopy (PLM) to quantify the orientation and phase retardation of the collagen architecture in cartilage at the same locations imaged by PS-OCT. The PS-OCT experiments demonstrate that articular cartilage has normal variations in polarization sensitivity at different locations over an intact bovine tibial plateau. Articular cartilage is not polarization sensitive along the vertical axis on the medial edge and central areas of the joint surface, but becomes polarization sensitive on the lateral edge of the tibia. This difference in optical phase retardation, as demonstrated by PS-OCT, is verified by PLM to be caused by differences in collagen fibril orientation at different locations of the tibial plateau. This study demonstrates that normal topographical variations in the collagen architecture of articular cartilage within a joint have a profound influence on the optical phase retardation detected by PS-OCT imaging, and therefore must be understood and mapped for specific joints before PS-OCT imaging can be used for the evaluation of the health status of individual joint surfaces.

In vivo optical coherence tomography detection of differences in regional large airway smoke inhalation induced injury in a rabbit model.

Smoke inhalation injury causes acute airway injury that may result in airway compromise with significant morbidity and mortality. We investigate the ability of high resolution endobronchial optical coherence tomography (OCT) to obtain real-time images for quantitatively assessing regional differences between upper tracheal versus lower tracheal and bronchial airway injury responses to smoke inhalation in vivo using a prototype spectral domain (SLD)-OCT system we constructed, and flexible fiber optic probes. 33 New Zealand White rabbits are intubated and mechanically ventilated. The treatment groups are exposed to inhaled smoke. The OCT probe is introduced through the endotracheal tube and maintained in place for 5 to 6 h. Images of airway mucosa and submucosa are obtained at baseline and at specified intervals postexposure. Starting within less than 15 min after smoke inhalation, there is significant airway thickening in the smoke-exposed animals. This is maintained over 5 h of imaging studies. The lower tracheal airway changes, correlating closely with carboxyhemoglobin levels, are much greater than upper tracheal changes. Significant differences are seen in lower trachea and bronchi after acute smoke inhalation compared to upper trachea as measured in vivo by minimally invasive OCT. OCT is capable of quantitatively detecting regional changes in airway swelling following inhalation injury.