Time-Sequential Monitoring of the Early Mesothelial Reaction in the Pleura after Cryoinjury.

(1) Background: An early mesothelial reaction of the pleura, leading to fibrosis, has been reported in animals after chemical or heavy metal exposure. However, the visual monitoring of early time-sequential mesothelial reaction-associated cryoinjury has not been fully investigated. Therefore, this study aimed to evaluate and visualize the early mesothelial reactions seen following cryoinjury using rabbit pleura. (2) Methods: We monitored the early mesothelial reaction in rabbit pleurae after cryoinjury using optical coherence tomography (OCT), in real-time, which was then compared with pathological images. Due to the penetration limit of OCT, we made a thoracic window to image the parietal and visceral pleurae in vivo. We also used an innovative technique for capturing the microstructure in vivo, employing a computer-controlled intermittent iso-pressure breath hold to reduce respiratory motion, increasing the resolution of OCT. We organized three sample groups: the normal group, the sham group with just a thoracic window, and the experimental group with a thoracic window and cryotherapy. In the experimental group, localized cryoinjury was performed. The mesothelial cells at the level of pleura of the cryotherapy-injured site were visualized by OCT within the first 30 min and then again after 2 days at the same site. (3) Results: In the experimental group, focal thickening of the parietal pleura was observed at the site of cryoinjury using OCT after the first injury, and it was then confirmed pathologically as focal mesothelial cell proliferation. Two days after cryoinjury, diffuse mesothelial cell proliferation in the parietal pleura was noted on the reverse side around the cryoinjured site in the same rabbit. In the sham group, no pleural reaction was found. The OCT and pathological examinations revealed different patterns of mesothelial cell reactions between the parietal and visceral pleurae: the focal proliferation of mesothelial cells was found in the parietal pleura, while only a morphological change from flat cells to cuboidal cells and a thickened monolayer without proliferation of mesothelial cells were found in the visceral pleural. (4) Conclusions: An early mesothelial reaction occurs following cryoinjury to the parietal and visceral pleurae.

Microbial metabolic responses and CO2 emissions differentiated by soil water content variation in subarctic tundra soils.

Recent rapid air temperature increases across the northern-latitude tundra have prolonged permafrost thawing and snow melting periods, resulting in increased soil temperature (Ts) and volumetric soil water content (SWC). Under prolonged soil warming at 8°C, Alaskan tundra soils were incubated in a microcosm system and examined for the SWC differential influence on the microbial decomposition activity of large molecular weight (MW) humic substances (HS). When one microcosm soil (AKC1-1) was incubated at a constant SWC of 41% for 90 days (T = 90) and then SWC was gradually decreased from 41% to 29% for another T = 90, the initial HS was partly depolymerized. In contrast, in AKC1-2 incubated at a gradually decreasing SWC from the initial 32% to 10% for T = 90 and then increasing to 27% for another T = 90, HS depolymerization was undetected. Overall, the microbial communities in AKC1-1 could maintain metabolic activity at sufficient and constant SWC during the initial T = 90 incubation. In contrast, AKC1-2 microbes may have been damaged by drought stress during the drying SWC regimen, possibly resulting in the loss of HS decomposition activity, which did not recover even after re-wetting to an optimal SWC range (20-40%). After T = 90, the CO2 production in both treatments was attributed to the increased decomposition of small-MW organic compounds (including aerobic HS-degradative products) within an optimal SWC range. We expect this study to provide new insights into the early effects of warming- and topography-induced SWC variations on the microbial contribution to CO2 emissions via HS decomposition in northern-latitude tundra soil.

Temporal Variations Rather than Long-Term Warming Control Extracellular Enzyme Activities and Microbial Community Structures in the High Arctic Soil.

In Arctic soils, warming accelerates decomposition of organic matter and increases emission of greenhouse gases (GHGs), contributing to a positive feedback to climate change. Although microorganisms play a key role in the processes between decomposition of organic matter and GHGs emission, the effects of warming on temporal responses of microbial activity are still elusive. In this study, treatments of warming and precipitation were conducted from 2012 to 2018 in Cambridge Bay, Canada. Soils of organic and mineral layers were collected monthly from June to September in 2018 and analyzed for extracellular enzyme activities and bacterial community structures. The activity of hydrolases was the highest in June and decreased thereafter over summer in both organic and mineral layers. Bacterial community structures changed gradually over summer, and the responses were distinct depending on soil layers and environmental factors; water content and soil temperature affected the shift of bacterial community structures in both layers, whereas bacterial abundance, dissolved organic carbon, and inorganic nitrogen did so in the organic layer only. The activity of hydrolases and bacterial community structures did not differ significantly among treatments but among months. Our results demonstrate that temporal variations may control extracellular enzyme activities and microbial community structure rather than the small effect of warming over a long period in high Arctic soil. Although the effects of the treatments on microbial activity were minor, our study provides insight that microbial activity may increase due to an increase in carbon availability, if the growing season is prolonged in the Arctic.

The relationships of present vegetation, bacteria, and soil properties with soil organic matter characteristics in moist acidic tundra in Alaska.

Soil organic matter (SOM) is related to vegetation, soil bacteria, and soil properties; however, not many studies link all these parameters simultaneously, particularly in tundra ecosystems vulnerable to climate change. Our aim was to describe the relationships between vegetation, bacteria, soil properties, and SOM composition in moist acidic tundra by integrating physical, chemical, and molecular methods. A total of 70 soil samples were collected at two different depths from 36 spots systematically arranged over an area of about 300 m × 50 m. Pyrolysis-gas chromatography/mass spectrometry and pyrosequencing of the 16S rRNA gene were used to identify the molecular compositions of the SOM and bacterial community, respectively. Vegetation and soil physicochemical properties were also measured. The sampling sites were grouped into three, based on their SOM compositions: Sphagnum moss-derived SOM, lipid-rich materials, and aromatic-rich materials. Our results show that SOM composition is spatially structured and linked to microtopography; however, the vegetation, soil properties, and bacterial community composition did not show overall spatial structuring. Simultaneously, soil properties and bacterial community composition were the main factors explaining SOM compositional variation, while vegetation had a residual effect. Verrucomicrobia and Acidobacteria were related to polysaccharides, and Chloroflexi was linked to aromatic compounds. These relationships were consistent across different hierarchical levels. Our results suggest that SOM composition at a local scale is closely linked with soil factors and the bacterial community. Comprehensive observation of ecosystem components is recommended to understand the in-situ function of bacteria and the fate of SOM in the moist acidic tundra.

Soil water content as a critical factor for stable bacterial community structure and degradative activity in maritime Antarctic soil.

Recent increases in air temperature across the Antarctic Peninsula may prolong the thawing period and directly affect the soil temperature (Ts) and volumetric soil water content (SWC) in maritime tundra. Under an 8°C soil warming scenario, two customized microcosm systems with maritime Antarctic soils were incubated to investigate the differential influence of SWC on the bacterial community and degradation activity of humic substances (HS), the largest constituent of soil organic carbon and a key component of the terrestrial ecosystem. When the microcosm soil (KS1-4Feb) was incubated for 90 days (T = 90) at a constant SWC of ~32%, the initial HS content (167.0 mg/g of dried soil) decreased to 156.0 mg (approximately 6.6% loss, p < 0.05). However, when another microcosm soil (KS1-4Apr) was incubated with SWCs that gradually decreased from 37% to 9% for T = 90, HS degradation was undetected. The low HS degradative activity persisted, even after the SWC was restored to 30% with water supply for an additional T = 30. Overall bacterial community structure remained relatively stable at a constant SWC setting (KS1-4Feb). In contrast, we saw marked shifts in the bacterial community structure with the changing SWC regimen (KS1-4Apr), suggesting that the soil bacterial communities are vulnerable to drying and re-wetting conditions. These microcosm experiments provide new information regarding the effects of constant SWC and higher Ts on bacterial communities for HS degradation in maritime Antarctic tundra soil.

Distinct Taxonomic and Functional Profiles of the Microbiome Associated With Different Soil Horizons of a Moist Tussock Tundra in Alaska.

Permafrost-underlain tundra soils in Northern Hemisphere are one of the largest reservoirs of terrestrial carbon, which are highly sensitive to microbial decomposition due to climate warming. However, knowledge about the taxonomy and functions of microbiome residing in different horizons of permafrost-underlain tundra soils is still limited. Here we compared the taxonomic and functional composition of microbiome between different horizons of soil cores from a moist tussock tundra ecosystem in Council, Alaska, using 16S rRNA gene and shotgun metagenomic sequencing. The composition, diversity, and functions of microbiome varied significantly between soil horizons, with top soil horizon harboring more diverse communities than sub-soil horizons. The vertical gradient in soil physico-chemical parameters were strongly associated with composition of microbial communities across permafrost soil horizons; however, a large fraction of the variation in microbial communities remained unexplained. The genes associated with carbon mineralization were more abundant in top soil horizon, while genes involved in acetogenesis, fermentation, methane metabolism (methanogenesis and methanotrophy), and N cycling were dominant in sub-soil horizons. The results of phylogenetic null modeling analysis showed that stochastic processes strongly influenced the composition of the microbiome in different soil horizons, except the bacterial community composition in top soil horizon, which was largely governed by homogeneous selection. Our study expands the knowledge on the structure and functional potential of microbiome associated with different horizons of permafrost soil, which could be useful in understanding the effects of environmental change on microbial responses in tundra ecosystems.

Serum Albumin and Disease Severity of Non-Cystic Fibrosis Bronchiectasis.

BACKGROUND: A clinical classification system has been developed to define the severity and predict the prognosis of subjects with non-cystic fibrosis (CF) bronchiectasis. We aimed to identify laboratory parameters that are correlated with the bronchiectasis severity index (BSI) and FACED score. METHODS: The medical records of 107 subjects with non-CF bronchiectasis for whom BSI and FACED scores could be calculated were retrospectively reviewed. The correlations between the laboratory parameters and BSI or FACED score were assessed, and multiple-linear regression analysis was performed to identify variables independently associated with BSI and FACED score. An additional subgroup analysis was performed according to sex. RESULTS: Among all of the enrolled subjects, 49 (45.8%) were male and 58 (54.2%) were female. The mean BSI and FACED scores were 9.43 ± 3.81 and 1.92 ± 1.59, respectively. The serum albumin level (r = -0.49), bilirubin level (r = -0.31), C-reactive protein level (r = 0.22), hemoglobin level (r = -0.2), and platelet/lymphocyte ratio (r = 0.31) were significantly correlated with BSI. Meanwhile, serum albumin (r = -0.37) and bilirubin level (r = -0.25) showed a significant correlation with the FACED score. Multiple-linear regression analysis showed that the serum bilirubin level was independently associated with BSI, and the serum albumin level was independently associated with both scoring systems. Subgroup analysis revealed that the level of uric acid was also a significant variable independently associated with the BSI in male bronchiectasis subjects. CONCLUSIONS: Several laboratory variables were identified as possible prognostic factors for non-CF bronchiectasis. Among them, the serum albumin level exhibited the strongest correlation and was identified as an independent variable associated with the BSI and FACED scores.

Neuron-specific enolase as a novel biomarker reflecting tuberculosis activity and treatment response.

BACKGROUND/AIMS: It is not clear which tests are indicative of the activity and severity of tuberculosis (TB). This study aimed to investigate the predictive value of neuron-specific enolase (NSE) and to determine the origin of NSE in TB patients. METHODS: A single-center retrospective analysis was conducted on newly diagnosed TB patients between January and December 2010. Patients were categorized into one of two disease groups (focal segmental or extensive) based on chest X-ray. Pre- and post-treatment NSE concentrations were evaluated. To determine the origin of serum NSE concentration, NSE staining was compared with macrophage-specific CD68 staining in lung tissues and with a tissue microarray using immunohistochemistry and immunofluorescence. RESULTS: A total of 60 newly diagnosed TB patients were analyzed. In TB patients, NSE serum concentration was significantly increased and NSE level decreased after treatment (p < 0.001). In proportion to serum high-sensitivity C-reactive protein concentration, the mean serum concentration of NSE in the extensive group (25.12 ng/mL) was significantly higher than that in the focal segmental group (20.23 ng/mL, p = 0.04). Immunohistochemical staining revealed a large number of macrophages that stained positively for both NSE and CD68 in TB tissues. In addition, NSE signals mostly co-localized with CD68 signals in the tissue microarray of TB patients. CONCLUSIONS: Our results suggest that NSE may be a practical parameter that can be used to monitor TB activity and treatment response. Elevated serum NSE level originates, at least in part, from macrophages in granulomatous lesions.

The successful treatment of refractory respiratory failure due to miliary tuberculosis: survival after prolonged extracorporeal membrane oxygenation support.

Acute respiratory distress syndrome (ARDS) has high morbidity and mortality. Although uncommon, pulmonary tuberculosis (TB) can cause ARDS in patients with extensive pulmonary parenchymal involvement. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is an accepted alternative option in refractory hypoxemic respiratory failure. It may normalize gas exchange and allow lung rest, avoiding ventilator induced lung injury. We report the case of a 44-year-old woman who developed ARDS secondary to pulmonary TB. Despite anti-TB treatment and mechanical ventilation, patient had persistent refractory hypoxemia. In order to prevent further lung injury, VV-ECMO support was performed for 73 days. Although the patient experienced several complications, patient was successfully managed on VV-ECMO. VV-ECMO support, in combination with anti-TB drugs, is a useful tool in the treatment of ARDS with refractory hypoxemia caused by miliary TB.

Multimodal imaging using optical coherence tomography and endolaryngeal ultrasonography in a new rabbit VX2 laryngeal cancer model.

BACKGROUND AND OBJECTIVE: Optical coherence tomography (OCT) provides ultrahigh-resolution imaging of tissues within a depth of a few millimeters, whereas ultrasonography provides good imaging further below the surface. We aimed to develop a minimally invasive rabbit model of VX2 laryngeal cancer, suitable for these two imaging modalities through a transoral approach. We also sought to study the utility of combined OCT and endolaryngeal ultrasonography (EUS) for evaluation of early and advanced laryngeal cancer, using this model. MATERIALS AND METHODS: VX2 tumor suspension was inoculated into the vocal folds of ten rabbits by injection through the trans-thyrohyoid membrane. The tumor model was characterized by rigid laryngoscopy and the tumor generation rate was 80% (8/10). Correlation between frequency-domain OCT and high-frequency EUS were used to visualize laryngeal tumors in the area of protruding mass formation in four rabbits, one week after injection (group A) and the remaining four rabbits two weeks after injection (group B). RESULTS: A small submucosal tumor was observed with rigid laryngoscopy in group A, and pathologic evaluation showed that the tumor was close to the basement membrane of the vocal fold mucosa, but had not invaded. OCT confirmed that the lining of the mucosa and basement membrane of the vocal fold was not broken, but the mucosa had thinned at the most elevated ridge. However, these lesions were not detected by EUS, and the overall shape of the tumor could not be clearly identified by EUS. A large tumor filling the laryngeal lumen was observed with rigid laryngoscopy in group B, and nearly the entire vocal fold, including the paraglottic space, was found to be involved on pathologic analysis. Distinguishing between normal structures and tumor was difficult using OCT; however, EUS confirmed the overall shape, size, and extent of the tumor, and the paraglottic space and thyroid cartilage were shown to be intact. CONCLUSIONS: This study is the first experimental trial, assessing the value of multimodal imaging using OCT and EUS in a rabbit VX2 laryngeal tumor model. Combining OCT and EUS helped to identify changes in laryngeal mucous membranes, and could potentially be used to identify laryngeal tumors and predict how tumors progress. This combined modality could help in determining tumor extent, assisting in diagnosis, and establishing a treatment plan for laryngeal cancer.

Bacterial community structure and soil properties of a subarctic tundra soil in Council, Alaska.

The subarctic region is highly responsive and vulnerable to climate change. Understanding the structure of subarctic soil microbial communities is essential for predicting the response of the subarctic soil environment to climate change. To determine the composition of the bacterial community and its relationship with soil properties, we investigated the bacterial community structure and properties of surface soil from the moist acidic tussock tundra in Council, Alaska. We collected 70 soil samples with 25-m intervals between sampling points from 0-10 cm to 10-20 cm depths. The bacterial community was analyzed by pyrosequencing of 16S rRNA genes, and the following soil properties were analyzed: soil moisture content (MC), pH, total carbon (TC), total nitrogen (TN), and inorganic nitrogen (NH4+ and NO3-). The community compositions of the two different depths showed that Alphaproteobacteria decreased with soil depth. Among the soil properties measured, soil pH was the most significant factor correlating with bacterial community in both upper and lower-layer soils. Bacterial community similarity based on jackknifed unweighted unifrac distance showed greater similarity across horizontal layers than through the vertical depth. This study showed that soil depth and pH were the most important soil properties determining bacterial community structure of the subarctic tundra soil in Council, Alaska.

Successful treatment of a tracheal squamous cell carcinoma with a combination of cryoablation and photodynamic therapy.

Malignant tumors of the trachea are rare, and account for less than 0.1% of all malignancies. Because there are no guidelines based on randomized clinical trials, the choice of treatment modalities and optimal sequences have not yet been established. In most cases of malignant airway obstruction, a single modality is chosen as the treatment of choice for management, but complete ablation becomes increasingly problematic with minimal residual lesions that require additional treatment. There were few case reports of the combined use of cryoablation and photodynamic therapy to treat tracheal cancer. Therefore, we present our experience of successful tracheal cancer treatment using this combination therapy. A bronchoscopic complete regression was obtained using these two modalities, and the procedures proved to be a safe and effective treatment option based on a one-year follow-up.

Respiratory review of 2012: bronchoscopic innovations and advances.

Recent advances in bronchoscopy have led to changes in clinical diagnostics and therapeutics in pulmonary medicine. In diagnostic bronchoscopy, there have also been new developments in endobronchial ultrasound technology which may be incorporated into clinical practice in the near future. Functional bronchoscopy, which evaluates information such as airway pressure, airflow, or gas exchange, suggests promising clinical advances in the near future. In therapeutic bronchoscopy, bronchoscopic volume reduction is a novel approach for the treatment of severe emphysema. In this review, seven recently published articles representing current advances in bronchoscopy are summarized and discussed.