Protein oxidation at the air-lung interface

Summary. Whilst performing its normal functions the lung is required to deal with a range of toxic insults. Whether these are infectious agents, allergens or air pollutants they subject the lung to a range of direct and indirect oxidative stresses. In many instances these challenges lead to oxidative alterations of peptides and proteins within the lung. Measurement of protein oxidation products permits the degree of oxidative stress to be assessed and indicates that endogenous antioxidant defences are overwhelmed. The range of protein oxidation products observed is diverse and the nature and extent of specific oxidation products may inform us about the nature of the damaging ROS and NOS. Recently, there has been a significant shift away from the measurement of these oxidation products simply to establish the presence of oxidative stress, to a focus on identifying specific proteins sensitive to oxidation and establishing the functional consequences of these modifications. In addition the identification of specific enzyme systems to repair these oxidative modifications has lead to the belief that protein function may be regulated through these oxidation reactions. In this review we focus primarily on the soluble protein components of within the surface liquid layer in the lung and the consequence of their undue oxidation.     

不同消毒方式对硅橡胶类义齿软衬材料消毒效果的实验研究

目的 对比微波、紫外线和环氧乙烷对Silagum硅橡胶义齿软衬材料的消毒效果.方法 将高温消毒后的软衬硅橡胶试件染菌(白色念珠菌),分别进行不同时间的紫外线、微波、环氧乙烷消毒,消毒后的试件用无菌生理盐水冲洗,无菌玻璃平皿收集冲洗液,接种环将冲洗液接种于沙氏琼脂平板培养基,37℃恒温培养24～48 h观察,菌落计数,评价消毒效果.结果 环氧乙烷(EO浓度600 mg/L)肖毒60 min灭菌率为100％;紫外线(功率40 W、波长253.7 nm、距离1 m)照射40 min可杀灭99％的白色念珠菌、50 min可完全杀灭;微波(800 W V 100％)照射1 min灭菌率为93％,照射2 min灭菌率为100％.结论 三种消毒方法都具有消毒效果,且消毒时间越长消毒效果越好;环氧乙烷、紫外线、微波消毒口腔硅橡胶义齿软衬材料可与高温高压灭菌达到同样的效果,而且方便、有效,是良好的软衬材料的消毒方法.     

New organic-walled Foraminifera (Protista) from the ocean's deepest point, the Challenger Deep (western Pacific Ocean)

We describe four new species and a new genus of very small (< 500 µm) Foraminifera from the Challenger Deep, the deepest point in the world's oceans (10 896 m water depth). All have transparent, mainly organic test walls that incorporate some minute agglutinated mineral particles of various shapes and compositions. Nodellum aculeata sp. nov. has an elongate proloculus with a pointed proximal end followed by a long, tubular section. The genus Resigella is represented by two species: in R. laevis sp. nov. , the test comprises 3–4 elongate, oval to cylindrical chambers while R. bilocularis sp. nov. has an oval proloculus followed by a second, larger globular chamber. The fourth species, Conicotheca nigrans gen. et sp. nov. , is characterized by a tiny, elongate, conical test filled with dark stercomata. Except in C. nigrans, the test wall has a brownish tinge; energy-dispersive spectroscopy (EDS) suggests the presence of organically bound Fe in all species including C. nigrans. Scanning electron microscopy (SEM) combined with EDS reveals distinctive wall structures. In N. aculeata, the proloculus is strewn with tiny (< 0.7 µm), elongate grains. In this species and in R. laevis, the test surface (except for the proloculus) is covered with a carpet of minute (∼0.1 µm) finger-like projections, rather similar to the organic cement of agglutinated Foraminifera. In R. bilocularis, the larger second chamber often has a partial veneer of fine mineral grains of varying composition, as well as organic areas consisting of meshed strands. SEM images of these three species reveal flat, plate-like features that we interpret as clay particles. In C. nigrans, the wall is relatively featureless except where the surface is raised into hummocky mounds and scale-like features, again probably clay particles. We suggest that these species represent a distinctive group of ‘agglutinated’ Foraminifera in which the test is predominately organic. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 153 , 399–423.     

Evidence of coelomic substances inducing genital maturation inPerinereis cultrifera (annelida polychaeta)

Summary Two peptides (B₁ and B₂) have been isolated from the coelomic fluid ofPerinereis cultrifera. These peptides are absent in sexually undifferentiated animals. They appear and become abundant during the oocyte submaturity stage. When B₁ and B₂ are simultaneously injected into very young females, they stimulate an important biosynthesis of oocyte glycoconjugates (certical alveoli). Injected separately, B₁ or B₂ leads to an oocyte structure similar to that of an anhormonal state. The modes of these actions were discussed.     

Role of labial glands in nesting behaviour of Chalicodoma sicula (Hymenoptera; Megachilidae)

ABSTRACT. Chalicodoma sicula (Rossi) is a megachilid bee that constructs ball-shaped nests out of mud, which are usually attached to twigs or are built on the face of rocks. The nesting female collects sand from a nearby area while mixing it with secretion from labial glands in the head. Chemical analysis of labial glands by gas chromatography mass spectrometry reveal that the secretion is composed of long chain hydrocarbons, mainly hentriacontene and tritriacontene. Once the nest is completed it is covered entirely with a sand-labial gland mixture. In this form the nest is rendered hydrophobic and is not destroyed by rain for several years.     

Purification and function of two analgesic and anti-inflammatory peptides from coelomic fluid of the earthworm,Eisenia foetida

The potential application of anti-inflammatory and analgesic compounds in medication and therapeutic care have become of increasing interest. We purified and characterized two novel analgesic and anti-inflammatory peptides, VQ-5 and AQ-5, from the coelomic fluid of the earthworm (Eisenia foetida). Their primary structures were determined as VSSVQ and AMADQ, respectively. Both peptides, especially AQ-5, exhibited analgesic activity in mouse models of persistent neuropathic pain and inflammation. AQ-5 also inhibited tumor necrosis factor alpha and cyclooxygenase-2 production. The mitogen-activated protein kinase signaling pathway, which is involved in analgesic and anti-inflammatory functions, was inhibited by AQ-5. Thus, the analgesic and anti-inflammatory effects of these peptides, especially AQ-5, demonstrated their potential as candidates for the development of novel analgesic medicines.     

The cascade mechanism to explain ozone toxicity: The role of lipid ozonation products

Ozone is so reactive that it can be predicted to be entirely consumed as it passes through the first layer of tissue it contacts at the lung/air interface. This layer includes the lung lining fluid (tracheobronchial surface fluid and alveolar and small airway lining fluid) and, where the lung lining fluid is thin or absent, the membranes of the epithelial cells that line the airways. Therefore, the biochemical changes that follow the inhalation of ozone must be relayed into deeper tissue strata by a cascade of ozonation products. Lipid ozonation products (LOP) are suggested to be the most likely species to act as signal transduction molecules. This is because unsaturated fatty acids are present in the lipids in both the lung lining fluid and in pulmonary cell bilayers, and ozone reacts with unsaturated fatty acids to produce ozone-specific products. Further, lipid ozonation products are finite in number, have structures that are predictable from the Criegee ozonation mechanism, and are small, diffusible, stable (or metastable) molecules. Preliminary data show that individual LOP cause the activation of specific lipases, which trigger the release of endogenous mediators of inflammation.     

Airspace Surface Chemistry Mediates O3-Induced Lung Injury

Ozone (O₃) produces diverse pulmonary pathophysiologies but with marked heterogeneities relative to species, age, anatomic site, disease, and exposure history. These pronounced susceptibility variations have remained largely undefined. We have postulated that interactions between inhaled O₃ and the airspace surfaces appreciably govern the distribution and extent of lung injury. O₃ displays unique absorption properties wherein chemical reaction with the epithelial lining fluid (ELF) maintains the net flux from the gas phase and couples O₃ uptake with the generation of products that lead to cell injury. Diversities in respiratory tract geometry and interfacial physicochemical conditions leads to spatially heterogeneous rates of O₃ flux into the ELF which combine with the local production of bioactive species to dictate the local dose. We have observed that both the uptake and distribution of acute epithelial injury is principally localized to the conducting airways. O₃ preferentially reacts with ELF ascorbic (AH₂) and uric acids (UA) although reaction with GSH and unsaturated fatty acids (UFA) occur to a lesser extent. UFA reactions may not generate sufficient bioactive materials to account for acute cell injury. Reactions with AH₂ and GSH, but not UA or Trolox, form secondary oxidants that initiate oxidation of model membranes and in vitro cell damage. However, secondary oxidant production is antioxidant concentration-dependent with a hyperbolic-shaped dose/response curve. Acquisition of species-specific data characterizing the pharmacodynamics of ELF substrate turnover under both basal and exposure conditions are critical to further our understanding of how surface chemistry regulates the balance between quenching of inhaled O₃ and conditions that promote production of bioactive/cytotoxic species and, therefore, biological outcomes.