利用气液界面无血清培养原代兔气管上皮细胞的研究

用低温酶消化法分离兔气管上皮细胞,具有细胞损伤小,活力及纯度高的优点,成纤维细胞污染极低。人胎盘胶原提高了气管上皮细胞贴壁性。无血清培养基能促进细胞增殖,分化和成熟。气液界面培养方式更好地模拟了气管上皮细胞的天然生长环境,在膜上呈复层生长,有利于细胞的分化成熟及功能表达。光镜下细胞形态及免疫组化细胞角蛋白染色阳性证实培养细胞为气管上皮细胞。本文所建立的兔气管上皮细胞体外气液界面无血清培养方法为研究气 管上皮细胞的生理和病理提供了一个十分有用的模型。     

气囊面罩联合气管插管通气救治对急诊心肺复苏患者动脉血气指标及预后的影响

摘要 目的：观察气囊面罩联合气管插管通气救治对急诊心肺复苏患者动脉血气指标及预后的影响。方法：选取中国人民解放军联勤保障部队第九四〇医院2020年4月-2022年10月期间收治的急诊心肺复苏患者86例作为研究对象。根据通气方式的不同将患者分为A组（n=41,常规气管插管通气救治）和B组（n=45,气囊面罩联合气管插管通气救治）。对比两组临床指征、急性生理与慢性健康评分（APACHEⅡ）、血气指标[二氧化碳分压（PCO2）、实际碳酸氢根（AB）、氧分压（PO₂）、二氧化碳总量（TCO₂）]、复苏成功率、格拉斯哥昏迷评分（GCS）、6个月存活率。结果：与A组相比,B组的自主呼吸恢复时间、心跳恢复时间、气道开放时间、意识恢复时间更短（P<0.05）。治疗后B组AB、TCO₂、PCO₂低于A组,PO₂高于A组（P<0.05）。治疗后B组APACHEⅡ评分低于A组,GCS高于A组（P<0.05）。B组的复苏成功率、6个月存活率高于A组（P<0.05）。结论：急诊心肺复苏患者使用气囊面罩联合气管插管通气救治,患者的临床指征、动脉血气指标均得到显著改善,且预后良好。     

The tympanal hearing organ of a fly: phylogenetic analysis of its morphological origins

A key adaptation for any parasitoid insect is the sensory modality that it uses to locate its host insect. All members of the speciose family Tachinidae (Diptera) are parasitoids, but only flies of the tribe Orminini use acoustic cues to find their hosts. Ormiine flies are parasitoids of various genera of crickets and katydids. Gravid females of one ormiine species, Ormia ochracea, hear the reproductive calling song of male field crickets and home in on those calls to locate their hosts. While many flies possess various kinds of ears to detect airborne sounds, only ormiine flies have been reported to possess true tympanal hearing organs. Such organs are wellknown to occur in their cricket and katydid hosts. The ormiine ear is an evolutionary innovation within Diptera. Our objective was to trace the phylogenetic origins of the tympanal hearing organ among higher flies. Since the ormiine hearing organ is a complex organ within the prothorax, we examined possible precursor structures in the prothoraces of selected Diptera. We have uncovered a suite of characters that define the ormiine ear. These characters in the prothorax include a pair of prosternal tympanal membranes, a pair of chordotonal sensory organs, and modifications of the tracheal system. We have been able to identify and trace the presumptive homologs of these ormiine characters through selected species of related Diptera, using the method of outgroup comparison.Dedicated to the memory of Dr. Edmund A. ArbasThis work was supported by grants from NIH (5RO1 DC 00103), NIMH (IKOS MH01148-01), NSF (240-1879A) and Hatch (NYC-191403) to R.R.H. and the Swiss Science Foundation and the Janggen-Pöhn Foundation to D.R.     

Typology of ephemerid chloride cells

Summary The tracheal gills of 16 species of mayfly larvae were studied with regard to the chloride cells. The ephemerid chloride cells occur as two main types: single cells and cell complexes. The single chloride cells are characterized by deep tubular or slit-like infoldings of the apical cell membrane, whereas the chloride cell complexes show numerous intercellular channels resulting from cellular interdigitation at the basolateral side. According to the structural organization of the apices, the ephemerid chloride cells may be classified into caviform, coniform, bulbiform and filiform types. In the caviform type (single chloride cell), the apex retracts to form an apical cavity similar to teleost chloride cells. In the other types (chloride cell complexes), there is a progressive extension of the central cell apex into or beyond the cuticle in the form of cones, bulbs or filaments. The common feature of all types is the differentiation of the cuticle into thin porous plates or envelopes covering or surrounding the various forms of apices.Histochemical precipitation of sodium and chloride in the apical region suggests that all types have basically the same function of salt absorption. The population of the various types differs with the species. However, there seem to be some taxonomic regularities with respect to the families. No relation was found between the types of chloride cells and habitat of the species.Supported by the National Science Foundation.     

A numerical and experimental study of compliance and collapsibility of preterm lamb tracheae

Knowledge of the mechanical behaviour of immature tracheae is crucial in order to understand the effects exerted on central airways by ventilatory treatments, particularly of Total Liquid Ventilation. In this study, a combined experimental and computational approach was adopted to investigate the compliance and particularly collapsibility of preterm lamb tracheae in the range of pressure likely applied during Total Liquid Ventilation (−30 to 30 cmH₂O). Tracheal samples of preterm lambs (n=5; gestational age 120–130 days) were tested by altering transmural pressure from −30 to 30 cmH₂O. Inflation (S_i) and collapsing (S_c) compliance values were calculated in the ranges 0 to 10 cmH₂O and –10 to 0 cmH₂O, respectively. During the tests, an asymmetric behaviour of the ΔV/V₀ vs. P curves at positive and negative pressure was observed, with mean S_i=0.013 cmH₂O⁻¹ and S_c=0.053 cmH₂O⁻¹. A different deformed configuration of the sample regions was observed, depending on the posterior shape of cartilaginous ring. A three-dimensional finite-element structural model of a single tracheal ring, based on histology measurements of the tested samples was developed. The model was parameterised in order to represent rings belonging to three different tracheal regions (craniad, median, caudal) and numerical analyses replicating the collapse test conditions were performed to evaluate the ring collapsibility at pressures between 0 and −30 cmH₂O. Simulation results were compared to experimental data to verify the model's reliability. The best model predictions occurred at pressures −30 to −10 cmH₂O. In this range, a model composed of median rings best interpreted the experimental data, with a maximum error of 2.7%; a model composed of an equal combination of all rings yielded an error of 12.6%.     

Formin3 is required for assembly of the F-actin structure that mediates tracheal fusion in Drosophila

During tracheal development in Drosophila, some branches join to form a continuous luminal network. Specialized cells at the branch tip, called fusion cells, extend filopodia to make contact and become doughnut shaped to allow passage of the lumen. These morphogenetic processes accompany the highly regulated cytoskeletal reorganization of fusion cells. We identified the Drosophila formin3 (form3) gene that encodes a novel formin and plays a role in tracheal fusion. Formins are a family of proteins characterized by highly conserved formin homology (FH) domains. The formin family functions in various actin-based processes, including cytokinesis and cell polarity. During embryogenesis, form3 mRNA is expressed mainly in the tracheal system. In form3 mutant embryos, the tracheal fusion does not occur at some points. This phenotype is rescued by the forced expression of form3 in the trachea. We used live imaging of GFP-moesin during tracheal fusion to show that an F-actin structure that spans the adjoining fusion cells and mediates the luminal connection does not form at abnormal anastomosis sites in form3 mutants. These results suggested that Form3 plays a role in the F-actin assembly, which is essential for cellular rearrangement during tracheal fusion.     

Metabolic rates during rest and activity in differently tracheated spiders (Arachnida,Araneae):<Emphasis Type="Italic"> Pardosa lugubris</Emphasis> (Lycosidae) and<Emphasis Type="Italic"> Marpissa muscosa</Emphasis> (Salticidae)

With flow-through respirometry under video tracking, the CO₂ release of adult male and female Pardosa lugubris (wolf spider) and Marpissa muscosa (jumping spider) was measured during rest and activity. Activity metabolism was measured in phases in which the animals were spontaneously active and during forced exercise. Standard metabolic rates (V_CO2/t) were 1.43 nmol s^–1 g^–1 in M. muscosa and 1.7–1.8 nmol s^–1 g^–1 in P. lugubris. Egg production caused higher resting rates in females compared with the males in P. lugubris. Maximum mass-specific CO₂ release, the additional amount of CO₂ released after activity and the factorial aerobic scope were higher in M. muscosa. Additionally, half-time recovery and the lag between end of activity and maximum CO₂ release were lower in the jumping spider. The results are consistent with the hypothesis that the well-developed tracheal system in jumping spiders increases the efficiency of the respiratory system in comparison with wolf spiders, which possess similarly developed lungs but only a simple tracheal system that is restricted to the opisthosoma.Communicated by G. Heldmaier     

Inhibition of AMPK expression in skeletal muscle by systemic inflammation in COPD rats

Background

Analysis of exhaled breath condensates (EBC) is a non-invasive technique to evaluate biomarkers such as antioxidants in the pediatric population, but limited data exists of its use in intubated patients, particularly newborns. Currently, tracheal aspirate (TA) serves as the gold standard collection modality in critically ill newborns, but this method remains invasive. We tested the hypothesis that glutathione status would positively correlate between EBC and TA collections in intubated newborns in the Newborn Intensive Care Unit (NICU). We also hypothesized that these measurements would be associated with alveolar macrophage (AM) glutathione status in the newborn lung.

Methods

Reduced glutathione (rGSH), glutathione disulfide (GSSG), and total GSH (rGSH + (2 X GSSG)) were measured in sequential EBC and TA samples from 26 intubated newborns via high performance liquid chromatography (HPLC). Additionally, AM glutathione was evaluated via immunofluorescence. Pearson’s correlation coefficient and associated 95% confidence intervals were used to quantify the associations between raw and urea-corrected concentrations in EBC and TA samples and AM staining. Statistical significance was defined as p ≤ 0.05 using two-tailed tests. The sample size was projected to allow for a correlation coefficient of 0.5, with 0.8 power and alpha of 0.05.

Results

EBC was obtainable from intubated newborns without adverse clinical events. EBC samples demonstrated moderate to strong positive correlations with TA samples in terms of rGSH, GSSG and total GSH. Positive correlations between the two sampling sites were observed in both raw and urea-corrected concentrations of rGSH, GSSG and total GSH. AM glutathione staining moderately correlated with GSSG and total GSH status in both the TA and EBC.

Conclusions

GSH status in EBC samples of intubated newborns significantly correlated with the GSH status of the TA sample and was reflective of cellular GSH status in this cohort of neonatal patients. Non-invasive EBC sampling of intubated newborns holds promise for monitoring antioxidant status such as GSH in the premature lung. Further studies are necessary to evaluate the potential relationships between EBC biomarkers in the intubated premature newborn and respiratory morbidities.     

Spiracle activity in moth pupae—The role of oxygen and carbon dioxide revisited

After decades of intensive research, the actual mechanism behind discontinuous gas exchange in insects has not been fully understood. One open question concerns the actual way (closed, flutter, and open) of how spiracles respond to tracheal gas concentrations. As the results of a classic paper [Burkett, B.N., Schneiderman, H.A., 1974. Roles of oxygen and carbon dioxide in the control of spiracular function in cecropia pupae. Biological Bulletin 147, 274-293] allow ambiguous interpretation, we thus reexamined the behavior of the spiracles in response to fixed, controlled endotracheal gas concentrations.The tracheal system of diapausing pupae of Attacus atlas (Saturniidae, Lepidoptera) was flushed with gas mixtures varying in PO₂ and PCO₂ while the behavior of the spiracles was monitored using changes in the pressure signal. This novel pressure based technique proved to be superior to classic visual observation of single spiracles. A two-dimensional map of the spiracle behavior in response to endotracheal PO₂ and PCO₂ was established. Typically, it contained two distinct regions only, corresponding to “closed” and “open” spiracles. A separate “flutter” region was missing. Because fluttering is commonly observed in moth pupae, we suggest that the intermittent spiracle opening during a flutter phase is an effect of non-steady-state conditions within the tracheal system. For low PCO₂ the minimum PO₂ resulting in open spiracles was linearly dependent upon PCO₂. Above a threshold of 1-1.5 kPa CO₂ the spiracles were open irrespective of PO₂. We propose a hypothetical spiracular control model, which is simple and explains the time course of endotracheal partial pressures during all phases of discontinuous gas exchange.     

Tracheal cancer: Role of radiation therapy

Purpose

To assess the results of tracheal cancer patients treatment and factors influencing prognosis.

Background

Primary malignant neoplasms of the trachea are rare. The treatment of choice for tracheal carcinomas is resection. Radiation therapy is recommended as a part of radical treatment or for palliation of symptoms.

Materials and methods

Between 1962 and 2006, 50 patients diagnosed with tracheal cancer were treated at the Centre of Oncology in Krakow. The analysis focused on locoregional recurrence-free survival (LRRFS), disease free survival (DFS) and overall survival (OS). Survival rates, univariate and multivariate analyses of prognostic factors were performed using the Kaplan–Meier method, the log rank test and Cox''s proportional hazard method, respectively.For over 40 years, patients were treated using different modalities: surgery followed by radiotherapy (6%), radiotherapy (78%), chemoradiotherapy (8%), and symptomatic treatment (8%).

Results

The 5-year LRRFS was 18%, DFS was 15% and OS was 17%. gender (favoured females) was the only prognostic factor for LRRFS. For OS, the independent prognostic factors were performance status (favoured Karnofsky higher than 80), stage and year of start of the treatment (later than 1988 vs. earlier – 5-year OS 20% vs. 12%).5-year OS in the following (strongly differentiated over the time) treatment modalities were: surgery followed by radiotherapy (66%), radiotherapy (16%), chemoradiotherapy (0%), and symptomatic treatment (0%).Of 44 patients treated with radiotherapy symptomatic partial response was observed in 32 patients and follow-up imaging studies revealed complete response in 5 patients, partial response in 25, stable disease in 4 or progressive disease in 4.

Conclusions

Radical treatment in patients in early stage and good performance status seems to be correlated with the improvement of survival. However, despite the fact that results of treatment are poor, radiotherapy offers symptomatic improvement.