Risk factors for postoperative adverse airway events in patients with primary oral cancer undergoing reconstruction without prophylactic tracheostomy.

OBJECTIVE: To identify risk factors associated with adverse airway events (AAEs) in primary oral cancer patients undergoing tumor ablation followed by free tissue transfer without prophylactic tracheostomy. METHODS: We retrospectively collected primary oral cancer patients who underwent tumor ablation surgery following free-tissue transfer without prophylactic tracheostomy during February 2017 to June 2019 in Chang Gung Memorial Hospital, Linkou Medical Center, Taiwan. 379 patients were included. Data were analysed from 2020 to 2021. Demographics, comorbidities, intraoperative variables and postoperative respiration profile were obtained from the medical record. Main outcome was postoperative AAEs, including requirement of endotracheal intubation after extubation and tracheostomy after prolonged intubation. RESULTS: Of the 379 patients, postoperative AAEs happened in 29 patients (7.6 %). In reintubation group, patients were older with more diabetes mellitus, hypertension and cerebrovascular disease. These patients had lower preoperative hemoglobin, creatinine, and albumin level with more intraoperative blood transfusion. In postoperative respiration profile, rapid shallow breathing index (RSBI) and PaO2/FiO2 (PF) ratio were poorer. On multivariate analysis, patient's age, tumor location, and cross-midline segmental mandibulectomy and a lower PF ratio were independent risk factors for postoperative AAEs. CONCLUSIONS: In head and neck cancer patients that underwent tumor ablation followed by free tissue transfer without prophylactic tracheostomy, patient's age, tumor location, cross-midline segmental mandibulectomy and P/F ratio are associated with postoperative AAEs.

Effect of body mass index on progressive bone mineral density in patients with cleft after secondary alveolar bone grafting.

BACKGROUND: Although childhood obesity matters, the association between body mass index (BMI) and bone mineral density (BMD) progression in grafted tissue after secondary alveolar bone grafting (ABG) for children with cleft alveolus is scarcely studied. Accordingly, this study explored the influence of BMI on BMD progression after ABG. METHODS: In total, 39 patients with cleft alveolus receiving ABG at the mixed dentition stage were enrolled. Patients were classified as underweight, normal weight, or overweight or obese according to age- and sex-adjusted BMI. BMD was measured in Hounsfield units (HU) from cone-beam computed tomography scans obtained 6 months (T1) and 2 years (T2) postoperatively. Adjusted BMD (HUgrafted tissue/HUpogonion, BMDa) was used for further analysis. RESULTS: For underweight, normal-weight, and overweight or obese patients, BMDaT1 values were 72.87%, 91.85%, and 92.89%, respectively (p = 0.727); BMDaT2 values were 111.49%, 112.57%, and 113.10% (p = 0.828); and density enhancement rates were 29.24%, 24.61%, and 22.14% (p = 0.936). No significant correlation was observed between BMI and BMDaT1, BMDaT2, or density enhancement rates (p = 0.223, 0.156, and 0.972, respectively). For patients with BMI < 17 and ≥ 17 kg/m2, BMDaT1 values were 89.80% and 92.89%, respectively (p = 0.496); BMDaT2 values were 111.49% and 113.10% (p = 0.216); and density enhancement rates were 23.06% and 26.39% (p = 0.573). CONCLUSION: Patients with different BMI values had similar outcomes (BMDaT1, BMDaT2, or density enhancement rate) after our ABG procedure in the 2-year postoperative follow-up.

Comparative assessment of orthodontic and aesthetic outcomes after orthognathic surgery with clear aligner or fixed appliance therapy.

BACKGROUND: Clear aligner therapy has an aesthetic advantage over fixed appliance therapy. However, to our knowledge, no study has objectively compared patient orthodontic and aesthetic outcomes between clear aligner and fixed appliance therapies administered after orthognathic surgery (OGS). METHODS: This study included patients with no history of congenital craniofacial deformities who underwent surgery-first OGS and received clear aligner or fixed appliance therapy. The patients' grades on the Dental Health Component (DHC) and Aesthetic Component (AC) of the Index of Orthodontic Treatment Need and scores on the Peer Assessment Rating (PAR) index were calculated before OGS (T0), after OGS (T1), and after orthodontic therapy (T2). RESULTS: This study included 33 patients (clear aligner therapy, 19; fixed appliance therapy, 14). No considerable between-group differences were noted in the DHC and AC grades at T0, T1, or T2. Furthermore, %reduction in the PAR index score was more significant in the clear aligner group (74.4%) than in the fixed appliance group (63.2%) from T0 to T1 (p = .035); however, no between-group differences were noted from T1 to T2 or from T0 to T2. Both groups exhibited substantially improved DHC grades, AC grades, and PAR index scores at T1 and T2. CONCLUSIONS: Patient outcomes were similar between the clear aligner and fixed appliance groups after orthodontic therapy. However, the former group exhibited more favorable immediate results after OGS than did the latter group. Thus, as an adjunct therapy for patients with malocclusion, clear aligner therapy may be more effective than fixed appliance therapy.

Three-dimensional comparative changes in the pharyngeal airway of patients with cleft after two-jaw orthognathic surgery.

BACKGROUND: The present study evaluated the three-dimensional changes of the pharyngeal airway after orthognathic surgery (OGS) in patients with unilateral and bilateral clefts, and in unilateral cleft patients with and without pharyngeal flap (PF). METHODS: Forty-five patients with unilateral or bilateral clefts receiving OGS were enrolled. Cone-beam computed tomography images were obtained before (T0) and after (T1) OGS. We measured the pharyngeal airway volumes, minimal cross-sectional area, and the horizontal displacement of facial landmarks. RESULTS: The patients with bilateral cleft exhibited smaller initial velopharyngeal volume (unilateral: 8623 mm 3; bilateral: 7781 mm 3; p = 0.211), while the velopharyngeal volume increased significantly with median of 744 mm 3 after OGS (p = 0.031). The median horizontal displacement of A point was 2.9 and 2.6 mm among the patients with unilateral and bilateral clefts, respectively (p = 0.276), and the median horizontal displacement of B point was -2.9 and -3.3 mm among patients with unilateral and bilateral clefts, respectively (p = 0.618). The unilateral cleft patients with PF exhibited lower initial velopharyngeal volume (PF+: 7582 mm 3; PF-: 8756 mm 3; p = 0.129) and a lower increase in velopharyngeal volume (PF+: 437 mm 3; PF-: 627 mm 3; p = 0.739) after OGS. CONCLUSIONS: Midface hypoplasia and the decrease in the velopharyngeal volume were more prominent among the bilateral cleft patients and the unilateral cleft patients with PF. After OGS, the velopharyngeal volume considerably increased among the bilateral cleft patients, but no considerable differences were noted among the unilateral cleft patients with PF.

Switching the Activity of CRISPR/Cas12a Using an Allosteric Inhibitory Aptamer for Biosensing.

The current CRISPR/Cas12a-based diagnostic techniques focus on designing the crRNA or substrate DNA elements to indirectly switch the trans-cleavage activity of Cas12a responsive to target information. Here, we propose the use of an allosteric DNA probe to directly regulate the trans-cleavage activity of Cas12a and present a method for sensing different types of analytes. An allosteric inhibitor probe is rationally designed to couple the target recognition sequence with the inhibitory aptamer of the CRISPR/Cas12a system and enables binding to a specific target to induce the change of conformation, which leads to the loss of its inhibitory function on Cas12a. As a result, the structure-switchable probe can regulate the degree of activity of Cas12a depending on the dose of target. Scalability of our strategy can be achieved by simply replacing the loop domain with different target recognition sequences. The proposed method was validated by detecting adenosine triphosphate and let-7a, giving the detection limits of 490 nM and 26 pM, respectively, and showing an excellent specificity. We believe that this work exploits a viable approach to use the inhibitory aptamer of Cas12a as a regulatory element for biosensing purposes, enriching the arsenal of CRISPR/Cas12a-based methods for molecular diagnostics and spurring further development and application of aptamers of the CRISPR/Cas system.

An Ultrasensitive, One-Pot RNA Detection Method Based on Rationally Engineered Cas9 Nickase-Assisted Isothermal Amplification Reaction.

RNA-guided clustered regularly interspaced short palindromic repeats (CRISPR) have revolutionized molecular diagnostics by offering versatile Cas effectors. We previously developed an isothermal amplification reaction method using Cas9 nickase (Cas9 nAR) to detect genomic DNA. However, slow dissociation of Cas9n from nicked double-stranded DNA (dsDNA) substrates dramatically hampers the cooperation between Cas9n and DNA polymerase, leading to low amplification efficiency. Here, we use structure-guided protein engineering to generate a Cas9n variant with faster kinetics and enhanced targeting specificity, and apply it to develop Cas9 nAR version 2 (Cas9 nAR-v2) by deftly merging reverse transcription with nicking-extension-displacement-based amplification for isothermal, one-pot RNA detection. This assay is validated by detecting Salmonella typhimurium 16S rRNA, Escherichia coli O157:H7 16S rRNA, synthetic SARS-CoV-2 genes, and HIV virus RNA, showing a quantitative analysis over a wide, linear range and a detection limit as low as fewer than ten copies of RNA molecules per reaction (20 µL volume). It also shows an excellent nucleotide-mutation discrimination capability in detecting SARS-CoV-2 variants. Furthermore, Cas9 nAR-v2 is compatible with low-cost point-of-care (POC) tests based on fluorescence and lateral-flow readouts. In summary, this method provides a new paradigm for sensitive, direct RNA detection and would spur the exploration of engineered Cas effectors with improved properties for a wide range of biological applications.

A programmable and sensitive CRISPR/Cas12a-based MicroRNA detection platform combined with hybridization chain reaction.

MicroRNAs (miRNAs) play an essential role in cancer diagnosis and prognosis. Developing a new method for sensitive detection of miRNA is constantly in demand. CRISPR/Cas12a system can nonspecifically cleave single-stranded DNA after specific recognition of target DNA, showing tremendous potential in molecular diagnostics. However, CRISPR-based detection methods require synthesizing different crRNAs for detecting different targets, which limit their widespread application. Herein, we design a versatile and sensitive miRNA detection platform based on CRISPR/Cas12a system combined with a hybridization chain reaction (HCR) circuit. In this design, the HCR circuit as the signal transducer converts each miRNA into multiple DNA duplexes, which act as the activators to activate the trans-cleavage activity of Cas12a for further signal amplification. More importantly, this platform can sensitively detect different miRNAs without changing the spacer sequence of crRNA due to the fixed activators formed by HCR. In addition, the consistency between the proposed platform and RT-qPCR in miRNA detection extracted from different cell lines validated its practicability, demonstrating the potential in clinical diagnosis of cancers and monitoring therapy.

Chemical Vapor Deposition-Fabricated Manganese-Doped and Potassium-Doped Hexagonal Tungsten Trioxide Nanowires with Enhanced Gas Sensing and Photocatalytic Properties.

Owing to its unique and variable lattice structure and stoichiometric ratio, tungsten oxide is suitable for material modification; for example, doping is expected to improve its catalytic properties. However, most of the doping experiments are conducted by hydrothermal or multi-step synthesis, which is not only time-consuming but also prone to solvent contamination, having little room for mass production. Here, without a catalyst, we report the formation of high-crystallinity manganese-doped and potassium-doped tungsten oxide nanowires through chemical vapor deposition (CVD) with interesting characterization, photocatalytic, and gas sensing properties. The structure and composition of the nanowires were characterized by transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS), respectively, while the morphology and chemical valence were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Electrical measurements showed that the single nanowires doped with manganese and potassium had resistivities of 1.81 × 0-5 Ω·m and 1.93 × 10-5 Ω·m, respectively. The doping contributed to the phase transition from monoclinic to metastable hexagonal for the tungsten oxide nanowires, the structure of which is known for its hexagonal electron channels. The hexagonal structure provided efficient charge transfer and enhanced the catalytic efficiency of the tungsten oxide nanowires, resulting in a catalytic efficiency of 98.5% for the manganese-doped tungsten oxide nanowires and 97.73% for the potassium-doped tungsten oxide nanowires after four hours of degradation of methylene blue. Additionally, the gas sensing response for 20 ppm of ethanol showed a positive dependence of doping with the manganese-doped and potassium-doped responses being 14.4% and 29.7%, respectively, higher than the pure response at 250 °C. The manganese-doped and potassium-doped tungsten oxide nanowires are attractive candidates in gas sensing, photocatalytic, and energy storage applications, including water splitting, photochromism, and rechargeable batteries.

An RNA-based catalytic hairpin assembly circuit coupled with CRISPR-Cas12a for one-step detection of microRNAs.

CRISPR-Cas nuclease-based nucleic acid detection has exhibited extraordinary value in the field of molecular diagnostics, but it usually involves two separate reaction steps of nucleic acid amplification and Cas-based endpoint detection, resulting in the use of multiple enzymes, inconvenient operation, and potential carry-over contamination. Here, we propose an RNA-based catalytic hairpin assembly (CHA) circuit coupled with CRISPR-Cas12a for one-step detection of microRNAs (miRNAs) at an isothermal condition. This method relies on the rational design of a spacer-blocking crRNA as a bridge between the two systems. The target miRNA can specifically trigger RNA-based CHA and induce a configurational change of the blocked crRNAs into precursor crRNAs (pre-crRNAs), which can be processed into mature crRNAs to function by leveraging the inherent RNase activities of Cas12a. In this way, the developed circuit achieves a femtomolar detection limit and shows an accurate detection of miRNA levels in different cell lines. Therefore, our method would provide a new paradigm to develop miRNA detection methods based on the CRISPR/Cas system.

Bifunctional Metal Oleate as an Alternative Method to Remove Surface Oxide and Passivate Surface Defects of Aminophosphine-Based InP Quantum Dots.

The optical properties of indium phosphide (InP) quantum dots (QDs) are significantly influenced by their surface native oxides, which are generally removed by treating InP cores with hydrofluoric acid (HF). Besides the harmful health effects of HF, its etching may cause over-etching or QD size broadening, and surface oxidation can also reoccur rapidly. In the present study, a safer bifunctional metal oleate treatment was developed to simultaneously remove the surface oxide layer and passivate the surface defects for aminophosphine-based InP QDs. Compared to conventional HF etching, the bifunctional metal oleate was able to more efficiently remove the surface oxide of InP cores and effectively preserve the oxide-free surface, leading to a 20% narrower photoluminescence (PL) bandwidth after growing a ZnSe/ZnS shell. The metal oleate treatment is thus considered a greener and safer post-synthetic method to remove InP surface oxide and provide additional passivation to improve the optical properties of aminophosphine-based InP QDs, which could have potential in industrial mass production.

Progressive Comparison of Density Assessment of Alveolar Bone Graft in Patients with Unilateral and Bilateral Cleft.

(1) Background: Continuing to observe the grafted bone mineral density (BMD) is essential to ensure the success of alveolar bone grafting (ABG) in patients with cleft lip and palate. This study elaborates on three methods that can be used to evaluate the progressive BMD. (2) Methods: Forty patients with unilateral or bilateral clefts receiving ABG were enrolled. Cone beam computed tomography (CBCT) scans were taken at 6 months (T1) and 2 years (T2) postoperatively. In CBCT, measurements were obtained on three different planes using the circle located 1 mm from the adjacent teeth (Method A), the largest circle within the defect (Method B), or the central circle with a diameter of 2 mm (Method C). The BMD was the average density of the three planes and was adjusted by pogonion density. Bland-Altman plots were used to evaluate the agreement of each method. Inter-rater reliability was confirmed by the intraclass correlation coefficient (ICC). (3) Results: For Method A, B, and C, the mean-adjusted BMD (BMD/pogonion density, BMDa) was 17.44%, 17.88%, and 17.69%, respectively, at T1 (p = 0.495), and 22.51%, 22.87%, and 22.74%, respectively, at T2 (p = 0.690); the density enhancement rates were 40.54%, 38.92%, and 43.15% (p = 0.382). Significant differences between the BMDa at T1 and T2 were observed (p < 0.001, <0.001, and 0.001, for Method A, B, and C, respectively). The volume of the grafted tissue remained stable during T1 and T2, and no significant correlation between density enhancement rate and volume loss was observed. (4) Conclusions: A significant increase in the BMD of grafted tissue was observed in the 2-year postoperative follow-up. The three methods for measuring BMDa via CBCT can be applied in post-ABG evaluations.

NLIP and HAD-like Domains of Pah1 and Lipin 1 Phosphatidate Phosphatases Are Essential for Their Catalytic Activities.

Saccharomyces cerevisiae Pah1 phosphatidate phosphatase (PAP) catalyzes the dephosphorylation of phosphatidate to yield diacylglycerol, controlling phospholipids and triacylglycerol metabolisms. Pah1 and human Lipin 1 are intrinsically disordered proteins with 56% and 43% unfolded regions, respectively. Truncation analysis of the conserved and non-conserved regions showed that N- and C-conserved regions are essential for the catalytic activity of Pah1. PAP activities can be detected in the conserved N-terminal Lipin (NLIP) domain and C-terminal Lipin (CLIP)/haloacid dehalogenase (HAD)-like domain of Pah1 and Lipin 1, suggesting that the evolutionarily conserved domains are essential for the catalytic activity. The removal of disordered hydrophilic regions drastically reduced the protein solubility of Pah1. Thioredoxin is an efficient fusion protein for production of soluble NLIP-HAD recombinant proteins in Escherichia coli.

A lateral flow strip combined with Cas9 nickase-triggered amplification reaction for dual food-borne pathogen detection.

Nucleic acid-based detection methods are accurate and rapid, which are widely-used in food-borne pathogen detection. However, traditional nucleic acid-based detection methods usually rely on special instruments, weakening their practicality for on-site tests in resource-limited locations. In this work, we developed a convenient and affordable method for food-borne pathogen detection based on a lateral flow strip combined with Cas9 nickase-triggered isothermal DNA amplification, which allows instrument-free and dual target detection. The genomic DNAs of two most common foodborne pathogens, Salmonella typhimurium and Escherichia coli, were simultaneously amplified in a one-pot reaction using specific sgRNAs and primers. The amplicons of genomic DNAs were double-labelled by digoxin/biotin and FITC/biotin tags, respectively, and directly visualized on a simple lateral flow strip. Our method exhibited a high specificity and sensitivity with a detection limit of 100 copies for genomic DNAs and 100 CFU/mL for bacteria. We believe that this method has potential to provide a convenient and low-cost point-of-care test for pathogen detection in the food quality surveillance.

Impact of the interval between neoadjuvant concurrent chemoradiotherapy and esophagectomy in the modern era: a population-based propensity-score-matched retrospective cohort study in Asia.

BACKGROUND: Neoadjuvant concurrent chemoradiotherapy (nCCRT) is one of the standard-of-care options for locally advanced esophageal squamous cell carcinoma (LA-ESqCC). The optimal interval between nCCRT and esophagectomy is unknown. METHODS: We constructed a propensity-score-matched [1:1 for long (8-12 weeks) vs short (4-7 weeks) intervals] cohort of LA-ESqCC patients who were diagnosed from 2011 to 2015 and treated with nCCRT via the Taiwan Cancer Registry and related databases. We compared the hazard ratios (HRs) of death using a robust variance estimator. We also evaluated alternative covariables, outcomes, and interval definitions. RESULTS: Our study population included 80 patients for each group; groups were balanced with respect to the observed covariables. There was no significant difference for the HR of death [1.22; 95% confidence interval 0.78-1.91, P = 0.39] when the long interval group was compared to the short interval group. There were also no significant differences when alternative covariables, outcomes, or interval definitions were evaluated. CONCLUSIONS: In this population-based study in modern Asia, we found that for LA-ESqCC patients treated with nCCRT and esophagectomy, overall survival was similar for either long or short intervals between nCCRT and esophagectomy. Randomized controlled trials are needed to verify this finding.

Evaluation of the necessity for chest drain placement following thoracoscopic wedge resection.

PURPOSE: To evaluate the outcomes of patients who underwent thoracoscopic wedge resection without chest drain placement. METHODS: The subjects of this retrospective study were 89 patients, who underwent thoracoscopic wedge resection at our hospital between January, 2013 and July, 2015. A total of 45 patients whose underlying condition did not meet the following criteria were assigned to the "chest drain placement group" (group A): peripheral lesions, healthy lung parenchyma, no intraoperative air leaks, hemorrhage or effusion accumulation, and no pleural adhesion. The other 44 patients whose underlying condition met the criteria were assigned to the "no chest drain placement group" (group B). Patient characteristics, specimen data, and postoperative conditions were analyzed and compared between the groups. RESULTS: Group A patients had poorer forced expiratory volume in one second (FEV1) values, less normal spirometric results, significantly higher resected lung volume, a greater maximum tumor-pleura distance, and a larger maximum tumor size. They also had a longer postoperative hospital stay. There was no difference between the two groups in postoperative complications. CONCLUSIONS: Avoiding chest drain placement after a thoracoscopic wedge resection appears to be safe and beneficial for patients who have small peripheral lesions and healthy lung parenchyma.

Impaired decision-making under risk is associated with gaming-specific inhibition deficits among college students with Internet gaming disorder.

A growing body of evidence indicates that both inhibition and decision-making deficits play essential roles in the development and maintenance of Internet gaming disorder (IGD). Clarifying whether impaired decision-making among individuals with IGD is related to poor inhibition will advance our understanding of IGD and contribute to intervention development. However, the relationship between these two functions remains unclear. In this study, we sought to systemically examine inhibitory processes, decision-making and the relationship between the two among individuals with IGD. Thirty-four individuals with IGD and 32 matched healthy controls (HCs) were recruited. In comparison to HCs, IGD subjects demonstrated inhibition deficits during performance of the gaming-related Go/No-Go task and impaired decision-making under risk. In addition, errors on No-Go trials during the gaming-related Go/No-Go task were positively associated with decision-making impairments under risk but not under ambiguity among IGD subjects. These results suggest individuals with IGD are impaired in some aspects of inhibition and decision-making functions, and that decision-making deficits under risk are linked to poor inhibition specifically related to gaming cues, which has implications for the development of novel intervention.

Extramedullary hematopoiesis (EMH) in laboratory animals: offering an insight into stem cell research.

Extramedullary hematopoiesis (EMH) is a pathological process secondary to underlying bone marrow (BM) insufficiency in adults. It is characterized by the emergence of multipotent hematopoietic progenitors scattered around the affected tissue, most likely in the spleen, liver, and lymph node, etc. EMH in patients frequently receives less medical attention and is neglected unless a compressive or obstructive hematopoietic mass appears to endanger the patient's life. However, on a biological basis, EMH reflects the alteration of relationships among hematopoietic stem and progenitor cells (HSPCs) and their original and new microenvironments. The ability of hematopoietic stem cells (HSCs) to mobilize from the bone marrow and to accommodate and function in extramedullary tissues is rather complicated and far from our current understanding. Fortunately, many reports from the studies of drugs and genetics using animals have incidentally found EMH to be involved. Thereby, the molecular basis of EMH could further be elucidated from those animals after cross-comparison. A deeper understanding of the extramedullary hematopoietic niche could help expand stem cells in vitro and establish a better treatment in patients for stem cell transplantation.

Decision-making for risky gains and losses among college students with Internet gaming disorder.

Individuals with Internet gaming disorder (IGD) tend to exhibit disadvantageous risky decision-making not only in their real life but also in laboratory tasks. Decision-making is a complex multifaceted function and different cognitive processes are involved in decision-making for gains and losses. However, the relationship between impaired decision-making and gain versus loss processing in the context of IGD is poorly understood. The main aim of the present study was to separately evaluate decision-making for risky gains and losses among college students with IGD using the Cups task. Additionally, we further examined the effects of outcome magnitude and probability level on decision-making related to risky gains and losses respectively. Sixty college students with IGD and 42 matched healthy controls (HCs) participated. Results indicated that IGD subjects exhibited generally greater risk taking tendencies than HCs. In comparison to HCs, IGD subjects made more disadvantageous risky choices in the loss domain (but not in the gain domain). Follow-up analyses indicated that the impairment was associated to insensitivity to changes in outcome magnitude and probability level for risky losses among IGD subjects. In addition, higher Internet addiction severity scores were associated with percentage of disadvantageous risky options in the loss domain. These findings emphasize the effect of insensitivity to losses on disadvantageous decisions under risk in the context of IGD, which has implications for future intervention studies.

Chylothorax following endovascular aortic repair with subclavian revascularization--a case report.

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) is becoming increasingly popular due to reduced perioperative morbidity and mortality compared with open surgical repair. However, complications can occur when the left subclavian artery is involved. When performing TEVAR with left carotid-subclavian artery bypass the stent graft will extend to the left common carotid artery. We herein present the case of a patient with a type B aortic dissection with an acute intramural hematoma. Chylothorax was noted after TEVAR with left carotid-subclavian artery bypass. CASE REPORT: A 66-year-old female with descending aortic dissection that was treated conservatively developed the sudden onset of back pain. Aortic computed tomography (CT) showed a type B intramural aortic dissection. TEVAR with left carotid-subclavian artery bypass was performed. Left chylothorax was noted after surgery with drainage of up to 1000 mL per day. Conservative management was ineffective. Thoracoscopic ligation of the thoracic duct was performed with resolution of the chyle leakage. CONCLUSION: Chylothorax can occur after TEVAR with carotid-subclavian artery bypass and likely results from thoracic duct injury. When conservative treatments fail, ligation of the thoracic duct cephalad to aortic hiatus can resolve the chyle leakage.

Overexpression of matrix metalloproteinases in lung tissue of patients with primary spontaneous pneumothorax.

BACKGROUND: Although blebs and bullae are frequently found in the apexes of lungs of patients with primary spontaneous pneumothorax (PSP), its pathogens remain unclear. OBJECTIVES: To examine the role of proteases [matrix metalloproteinase (MMP)-2, MMP-7 and MMP-9] and antiproteases [tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2, TIMP-3 and TIMP-4] in the pathogenesis of PSP. METHOD: Fifty consecutive PSP patients who received standard surgical care were enrolled in the study. Lung tissues from 20 patients with stage I non-small cell lung cancer were used as a control. Immunohistochemistry (IHC), reverse transcription-polymerase chain reaction (RT-PCR) and gelatin zymography were used to evaluate the expression of MMP and TIMP in the lung tissue of patients with PSP. RESULTS: Overexpression of MMP-2, MMP-7 and MMP-9 was found in the afflicted lung by IHC, zymography and RT-PCR. By IHC, higher expression of MMP-2 and MMP-9 in PSP patients was identified in alveolar macrophages and type II pneumocytes (88 and 92% of patients in macrophages, and 72 and 70% of patients in type II pneumocytes, respectively). MMP-2, MMP-7 and MMP-9 expression in patients was higher in mesothelial cells (66, 76 and 76%). Overexpression of TIMP-2 was detected in the extracellular matrix around bullae and blebs. Expression levels of TIMP-1, TIMP-3 and TIMP-4 were negligible (<10% of cells) in both PSP patients and controls. CONCLUSIONS: MMP-2, MMP-9, MMP-7 and TIMP-2 were upregulated in PSP lesions. These results suggest that an imbalance between the expression of proteases and antiproteases may be involved in the pathogeneses of PSP.