胚胎干细胞对博来霉素性小鼠肺损伤的治疗作用

目的：比较3种不同种类的胚胎干细胞（C57BL/6J、S8和人胚胎干细胞）对博莱霉素所致C57BL/6J小鼠肺损伤的治疗作用。方法： C57BL/6J雌性小鼠50只，随机分为5组：空白对照组、模型组、模型＋C57BL/6J-胚胎干细胞组、模型＋S8-胚胎干细胞组、模型+人胚胎干细胞组，每组10只。除空白对照组外，其余4组均经气管给予博莱霉素制作肺损伤模型，3组干细胞给予组在小鼠造模后1 h，分别经尾静脉移植1.0×109cells/L C57BL/6J胚胎干细胞、S8胚胎干细胞和人胚胎干细胞，模型组给予相同体积的生理盐水。观察小鼠的生存时间、肺组织病理变化、肺组织羟脯氨酸的含量和干细胞在肺内的定植情况。结果：3组胚胎干细胞（ESC）给予组小鼠第8 d死亡率明显低于模型组（模型组为50％，C57BL/6J-ESC组为38%，S8-ESC组为20%，人-ESC组为20%）；S8-ESC移植组，肺组织病理变化明显轻于模型组，其它干细胞移植组与模型组相似。S8-ESC移植组肺组织羟脯氨酸含量明显低于模型组(P<0.01)，人-ESC组与模型组比较,P<0.05, C57BL/6J-ESC组与模型组比较肺组织羟脯氨酸含量差别不明显(P>0.05)。3种胚胎干细胞移植后分别于1、3、12和24 h取材，均可检测到其在肺内停留的信号，但以3 h取材组信号最强。3 d后肺内所有干细胞信号消失。结论： S8胚胎干细胞可以有效地提高C57BL/6J小鼠肺组织对博莱霉素的耐受性，减轻博莱霉素引起的急性肺损伤。     

CEST MRI with distribution‐based analysis for assessment of early stage disease activity in a mouse model of multiple sclerosis: An initial study

Imaging biomarkers that can detect pathological changes at an early stage of multiple sclerosis (MS) may allow earlier therapeutic intervention with an improved outcome. Using a mouse model of MS, termed as experimental autoimmune encephalomyelitis (EAE), we performed chemical exchange saturation transfer (CEST) MRI at a very early stage before symptom onset (6 days post‐induction) for assessment of changes in tissues that appear “normal” with conventional MRI. The collected CEST Z‐spectra signals (S_sat/S₀) were analyzed using a histogram‐guided method to determine the contributions from various offset frequencies. Histogram analysis showed that EAE mice exhibit a more heterogeneous distribution with lower peak heights in the hindbrain compared with naïve mice at saturation offsets of 1 and 2 ppm. At these two offsets, both the mean S_sat/S₀ and the mean MTR_asym values in the cerebellum and brain stem are significantly different between EAE and naïve mice (P < 0.05). Immunofluorescent staining validated the presence of neuroinflammation, with IBA1‐positive cells detected throughout the hindbrain including the cerebellum and brain stem. Follow‐up MRI at the symptom onset (score = 1.5–2.5, 13 days post‐induction) confirmed gadolinium‐enhanced periventricular lesions. CEST Z‐spectra signals also changed by this time. The proposed three‐level histogram‐oriented analysis is simple to execute and robust for detecting subtle changes in Z‐spectra signals, which does not require a priori knowledge of damage locations or contributing offset components. CEST MRI signals at 1 and 2 ppm were sensitive to the subtle pathological changes at an early stage in EAE mice, and have potential as novel imaging biomarkers complementary to functional and physiological MRI measures.     

吉非替尼抑制博莱霉素诱导的小鼠肺纤维化

目的:观察吉非替尼对博莱霉素诱导的小鼠肺纤维化的抑制作用。方法:将40只SPF级雌性BALB/c小鼠分为4组:对照组(气管滴入生理盐水)、单纯口服吉非替尼组(吉非替尼灌胃200 mg/kg)、纤维化组(气管滴入博莱霉素3 mg/kg)、纤维化吉非替尼干预组(气管滴入博莱霉素+吉非替尼灌胃20 mg/kg)。实验第14 d杀鼠取肺,左肺石蜡切片行HE染色与Masson染色,免疫组化检测总表皮生长因子受体(EGFR)及磷酸化EG-FR;取右肺检测羟脯氨酸含量。结果:纤维化吉非替尼干预组肺病理损伤较纤维化组减轻,气道上皮下胶原沉积及肺羟脯氨酸含量减少(P0.05),气道上皮及肺间质细胞磷酸化EGFR表达评分下降(P0.05)。单纯口服吉非替尼组小鼠气道上皮下未见明显胶原沉积,肺羟脯氨酸含量及磷酸化EGFR表达评分与对照组相比无显著差异(P0.05)。结论:吉非替尼灌胃能显著抑制博莱霉素诱导的小鼠肺纤维化,大剂量(200 mg/kg)吉非替尼灌胃未引起明显肺纤维化。     

Time course of bleomycin-induced lung fibrosis

Intratracheal instillation (IT) of bleomycin is a widely used experimental model for lung fibrosis. In this study we describe the time-course of bleomycin-induced lung fibrosis in mice using computer-assisted morphometry. C57Bl/6J mice were treated with a single IT dose of bleomycin or control saline. Animals were killed 3, 6, 14 and 21 days post-IT. Lung injury was evaluated by analysis of bronchoalveolar lavage (BAL) fluid, hydroxyproline concentration in the lung, routine light microscopic examination resulting in a semiquantitative morphological index (SMI) of lung injury, and quantitative morphological measurements (fibrosis fraction and alveolar wall area fraction) aided by optimas image analysis software. Changes in BAL fluid attributed to bleomycin treatment include increased total cell count (days 14 and 21), and increased percentage of neutrophils (days 3 and 6) followed by a sustained increase in lymphocytes (days 6, 14 and 21). Hydroxyproline levels increased in bleomycin-treated mice on days 14 and 21. Median SMI grades were significantly elevated on days 3, 14 and 21. Computer-assisted morphometry demonstrated a 3-fold increase in fibrosis fraction and a 1.3-fold increase in wall area fraction in bleomycin-treated mice on day 14, with no further increase on day 21. These data also demonstrate that the most suitable time point for assessing lung fibrosis in this model is 14 days after IT instillation of bleomycin, based on the observation that at 14 days the animals developed extensive fibrosis, but had less variability in the fibrotic response and lower mortality than later at 21 days. Computer-assisted morphometry provides objective and quantitative measurements that are a useful tool for the evaluation of bleomycin-induced lung injury.     

Role of interleukin-6 in bleomycin-induced lung inflammatory changes in mice

Interleukin-6 (IL-6) is known to be involved in the pathogenesis of various inflammatory diseases, but its role in bleomycin (BLM)-induced lung injury and subsequent fibrotic changes remains to be determined. We evaluated the role of IL-6 in the lung inflammatory changes induced by BLM using wild-type (WT) and IL-6-deficient (IL-6(-/-)) mice. The mice were treated intratracheally with 1 mg/kg BLM and killed 2, 7, or 21 days later. Lung Inflammation in the acute phase (Days 2 and 7) was assessed by differential cell counts in bronchoalveolar lavage (BAL) fluid and cytokine levels in the lung. Lung fibrotic changes were evaluated on Day 21 by histopathology and collagen assay. On Day 2, BLM administration induced significant increases in the numbers of total cells, macrophages, and neutrophils in BAL fluid, which were attenuated in IL-6(-/-) mice (P < 0.05). Lung pathology also showed inflammatory cell accumulation, which was attenuated in the IL-6(-/-) mice compared with WT mice. In WT mice, elevated levels of TGF-beta(1) and CCL3 were observed 2 and 7 days after BLM challenge, respectively. On Day 7, BLM-induced inflammatory cell accumulation did not differ between the genotypes. Lung pathology 21 days after BLM challenge revealed significant fibrotic changes with increased collagen content, which was attenuated in IL-6(-/-) mice. Although the TGF-beta(1) level in the lung did not differ between the genotypes on Day 21, CCL3 was significantly lower in IL-6(-/-) mice. These results indicate that IL-6 may play an important role in the pathogenesis of BLM-induced lung injury and subsequent fibrotic changes.     

Inhibition of bleomycin lung toxicity by N-acetyl cysteine in the rat

N-acetyl cysteine (NAC) has recently been shown to have antioxidant properties, and since bleomycin produces pulmonary damage via free oxygen radical toxicity, the possible protective effect of NAC on bleomycin lung toxicity was investigated. Rats received saline (n = 7), NAC (n = 6), bleomycin (n = 7) or bleomycin and NAC (n = 6) by direct intratracheal injection. Seven days later the animals were killed and the lungs processed for histology or morphometry. All rats treated with bleomycin only had typical changes of bleomycin lung toxicity whereas the animals treated with bleomycin and NAC had minimal pathology. The control animals had normal lungs. These results were confirmed by morphometry which demonstrated significantly higher volume densities (p less than .01) of alveolar wall and free alveolar cells in the bleomycin group compared to the other 3 groups. It is concluded that NAC inhibits bleomycin lung toxicity when administered by direct intratracheal injection.     

Bleomycin injury of the lung in a mast-cell-deficient model

Lung mast cell hyperplasia and fibrosis is induced by bleomycin lung injury. The role of the mast cell in this process of injury and resultant fibrosis is unclear. Mutant mi/mi mice, profoundly mast-cell-deficient, were treated with intraperitoneal bleomycin and demonstrated minimal acute inflammatory and chronic fibrotic responses. Lung histamine values determined at 14 and 42 days after bleomycin injury in mi/mi mice were not increased compared to untreated mi/mi animals. However, lung histamine levels in normal mice demonstrate a 300% increase over controls on Day 14 after bleomycin injury, and then returned to baseline by Day 42. The mi/mi BAL cell recovery at 2 weeks after injury and lung hydroxyproline levels at 4 weeks after injury were not altered from baseline. The normal litter mates, in contrast, demonstrated significant increases compared to controls in both of these parameters (p<0.01,p<0.04). Although the mi/mi mouse is also deficient in basophils, natural killer cells and functional osteoclasts, there is no evidence of lowered pulmonary defense mechanism and neutrophils and alveolar macrophages are present in normal numbers. This investigation supports the hypothesis that the mast cell contributes to bleomycin-induced lung injury and fibrosis.     

Extracellular matrix powder protects against bleomycin-induced pulmonary fibrosis

Pulmonary fibrosis refers to a group of lung diseases characterized by inflammation, fibroblast proliferation, and excessive collagen deposition. Although the mechanisms underlying pulmonary fibrosis are poorly understood, current evidence suggests that epithelial injury contributes to the development of fibrosis. Regenerative medicine approaches using extracellular matrix (ECM) scaffolds have been shown to promote site-specific tissue remodeling. This led to the hypothesis that particulate ECM would promote normal tissue repair and attenuate bleomycin-induced pulmonary fibrosis. C57BL/6 mice were treated intratracheally with bleomycin or saline with or without a particulate form of ECM scaffold from porcine urinary bladder matrix (UBM-ECM) or enzymatically digested UBM-ECM. Mice were sacrificed 5 and 14 days after exposure. Compared to control mice, bleomycin-exposed mice had similar increases in inflammation in the bronchoalveolar lavage fluid regardless of UBM-ECM treatment. However, 14 days after exposure, lung histology and collagen levels revealed that mice treated with bleomycin and the particulate or digested UBM-ECM had negligible fibrosis, whereas mice given only bleomycin had marked fibrosis. Administration of the particulate UBM-ECM 24 h after bleomycin exposure also significantly protected against pulmonary injury. In vitro epithelial cell migration and wound healing assays revealed that particulate UBM-ECM promoted epithelial cell chemotaxis and migration. This suggests that promotion of epithelial wound repair may be one mechanism in which UBM-ECM limits pulmonary fibrosis.     

Cone-beam micro computed tomography dedicated to the breast

We developed a scanner for micro computed tomography dedicated to the breast (BµCT) with a high resolution flat-panel detector and a microfocus X-ray tube. We evaluated the system spatial resolution via the 3D modulation transfer function (MTF). In addition to conventional absorption-based X-ray imaging, such a prototype showed capabilities for propagation-based phase-contrast and related edge enhancement effects in 3D imaging. The system limiting spatial resolution is 6.2 mm⁻¹ (MTF at 10%) in the vertical direction and 3.8 mm⁻¹ in the radial direction, values which compare favorably with the spatial resolution reached by mini focus breast CT scanners of other groups. The BµCT scanner was able to detect both microcalcification clusters and masses in an anthropomorphic breast phantom at a dose comparable to that of two-view mammography. The use of a breast holder is proposed in order to have 1–2 min long scan times without breast motion artifacts.     

Dose-guided radiotherapy for lung tumors

The transit in vivo dosimetry performed by an electronic portal imaging device (EPID) is a very practical method to check error sources in radiotherapy. Recently, the present authors have developed an in vivo dosimetry method based on correlation functions, F (w, L), defined as the ratio between the transit signal, S _t (w, L), by the EPID and the mid-plane dose, D _m (w, L), in a solid water phantom as a function of the phantom thickness, w, and of the field dimensions, L. In particular, generalized correlation functions F (w, L) for 6, 10 and 15 MV X-ray beams supplied by a pilot Varian linac, are here used by other three linacs operating in two centers. This way the workload, due to measurements in solid water phantom, needed to implement the in vivo dosimetry method was avoided. This article reports a feasibility study on the potentiality of this procedure for the adaptive radiotherapy of lung tumors treated by 3D conformal radiotherapy techniques. In particular, the dose reconstruction at the isocenter point D _iso in the lung tumor has been used as dose-guided radiotherapy (DGRT), to detect the inter-fraction tumor anatomy variations that can require new CT scans and an adaptive plan. When a difference greater than 6% between the predicted dose by the treatment planning system (TPS), D _iso,TPS and the D _iso was observed, the clinical action started to detect possible anatomical lung tumor changes. Twelve over twenty patients examined presented in vivo dose discrepancies due to the tumor morphological changes during treatments, and these results were successively confirmed by new CT scans. In this work, for a patient that showed for all beams, D _iso values over the tolerance level, the new CT scan was used for an adaptive plan. The lung dose volume histogram for D _iso,TPS = 2 Gy per fraction suggested the adaptive plan. In particular, the lung volume included in 2 Gy increased from 350 cm³ of the original plan to 550 cm³ of the hybrid plan, while for the adaptive plan the lung volume included in 2 Gy decreased to 15 cm³. Moreover, the mean doses to the organs at risk were reduced to 70%. The results of this research show that the DGRT procedure by the D _iso reconstruction, integrated with radiological imaging, was feasible for periodic investigation on morphological lung tumor changes. This feasibility study takes into account the accuracy of two algorithms based on the pencil beam and collapsed cone convolution models for dose calculations where large density inhomogeneities are present.     

Increases in lung prolyl hydroxylase and superoxide dismutase activities during bleomycin-induced lung fibrosis in hamsters

Intratracheal administration of bleomycin causes pulmonary fibrosis in hamsters. Using this model the activities of lung prolyl hydroxylase and superoxide dismutase and the accumulation of neutral salt soluble and insoluble collagens have been determined. One unit of bleomycin was injected intratracheally to hamsters, whereas control animals received an equivalent volume of sterile saline by the same route. Total lung prolyl hydroxylase activity was significantly elevated at all times following bleomycin treatment. The activity was increased as early as 2 days, peaked to a maximum value of 400% of the control at 14 days, followed by a sharp decline to 235% and 180% of the control activity at 21 and 28 days after bleomycin treatment, respectively. Except for the earliest time (2 days), lung prolyl hydroxylase specific activity was also significantly elevated at all times after bleomycin treatment. A significant increase in both total and specific activities of lung superoxide dismutase was also observed at all times after bleomycin treatment. Total activity peaked to a maximum value of 315% of the control activity at 14 days and the specific activity to a maximum value of 190% of the control at 21 days after bleomycin treatment. Thereafter, both activities declined, but were still significantly elevated over the control at 28 days after the treatment. Lung proline pool size was significantly increased at all times and attained a maximum value of 372% of the control at 14 days after bleomycin treatment. Increases in the lung prolyl hydroxylase and superoxide dismutase activities and in the proline pool size preceded the significant increases in neutral salt soluble and insoluble collagens which occurred at 7 days after bleomycin treatment and continued to be significantly elevated for the remaining period of the study.     

Effects of injury and repair of the pulmonary endothelium on lung metastasis after bleomycin

Acute endothelial injury induced by bleomycin has been shown to enhance the localization and metastasis of circulating tumour cells. In the present study we wished to determine whether increased metastases to the lung is related to the degree of endothelial damage as indicated by morphology and protein leakage to alveoli and whether the progression to repair with pulmonary fibrosis also effects metastatic tumour growth. C57b1/6 mice were injected with a single intravenous dose of bleomycin (120 mg/kg). After 5 days, severe enothelial injury was demonstrated by morphology and by increased levels of protein in lung lavage fluid. When [131I]-iododeoxyuridine labeled syngeneic fibrosarcoma cells were injected intravenously at this time, a 9-fold increase in their localization was detected 24 h later in bleomycin-treated lungs compared with saline controls. By electron microscopy tumour cells were observed at sites of denuded vascular basement membrane. There was also a significant increase in the number of gross metastases which developed subsequently and in the percentage of lung occupied by tumour in the bleomycin group. Animals examined 10 days after bleomycin showed less endothelial damage and a smaller increase in tumour cell localization and metastases. At 21 days, when endothelial structure and alveolar protein levels had returned to normal, and at 6 weeks, when there was focal fibrosis, no increase in tumour cell localization or metastases was found. It is concluded that damage to the pulmonary endothelium is a key factor in enhancing the trapping of circulating tumour cells and increasing metastatic tumour growth after bleomycin.     

Thymosin β4 reduces IL-17-producing cells and IL-17 expression,and protects lungs from damage in bleomycin-treated mice

Thymosin β4 (Tβ4) is a highly conserved peptide with immunomodulatory properties. In this research we investigated the effects of Tβ4 on the bleomycin-induced lung damage in CD-1 mice and the changes in the number of IL-17-producing cells as well as the IL-17 expression in the lung. Male CD-1 mice were treated with bleomycin (1 mg/kg) in the absence or the presence of Tβ4 (6 mg/kg delivered intra-peritoneally on the day of bleomycin treatment and for 2 additional doses). After sacrifice one week later, lung histology, measurement of collagen content of the lung, Broncho Alveolar Lavage Fluid (BALF) analysis, evaluation of IL17-producing cells in the blood as well as RT-PCR and IHC in the lung tissue were performed.     

Protease inhibitors elicit anti‐inflammatory effects in CF mice with Pseudomonas aeruginosa acute lung infection

Pseudomonas aeruginosa is the major respiratory pathogen in patients with cystic fibrosis (CF). P. aeruginosa‐secreted proteases, in addition to host proteases, degrade lung tissue and interfere with immune processes. In this study, we aimed at evaluating the possible anti‐inflammatory effects of protease inhibitors Marimastat and Ilomastat in the treatment of P. aeruginosa infection. Lung infection with the P. aeruginosa PAO1 strain was established in wild‐type and cystic fibrosis transmembrane conductance regulator (CFTR) knock‐out C57BL/6 mice expressing a luciferase gene under control of bovine interleukin (IL)‐8 promoter. After intratracheal instillation with 150 µM Marimastat and Ilomastat, lung inflammation was monitored by in‐vivo bioluminescence imaging and bacterial load in the lungs was assessed. In vitro, the effects of protease inhibitors on PAO1 growth and viability were evaluated. Acute lung infection was established in both wild‐type and CFTR knock‐out mice. After 24 h, the infection induced IL‐8‐dependent bioluminescence emission, indicating lung inflammation. In infected mice with ongoing inflammation, intratracheal treatment with 150 µM Marimastat and Ilomastat reduced the bioluminescence signal in comparison to untreated, infected animals. Bacterial load in the lungs was not affected by the treatment, and in vitro the same dose of Marimastat and Ilomastat did not affect PAO1 growth and viability, confirming that these molecules have no additional anti‐bacterial activity. Our results show that inhibition of protease activity elicits anti‐inflammatory effects in cystic fibrosis (CF) mice with acute P. aeruginosa lung infection. Thus, Marimastat and Ilomastat represent candidate molecules for the treatment of CF patients, encouraging further studies on protease inhibitors and their application in inflammatory diseases.     

Role of the SDF-1/CXCR4 axis in the pathogenesis of lung injury and fibrosis

Stromal cell-derived factor-1 (SDF-1) participates in mobilizing bone marrow-derived stem cells, via its receptor CXCR4. We studied the role of the SDF-1/CXCR4 axis in a rodent model of bleomycin-induced lung injury in C57BL/6 wild-type and matrix metalloproteinase (MMP)-9 knockout mice. After intratracheal instillation of bleomycin, SDF-1 levels in serum and bronchial alveolar lavage fluid increased. These changes were accompanied by increased numbers of CXCR4(+) cells in the lung and a decrease in a population of CXCR4(+) cells in the bone marrow that did not occur in MMP-9(-)/(-) mice. Both SDF-1 and lung lysates from bleomycin-treated mice induced migration of bone marrow-derived stem cells in vitro that was blocked by a CXCR4 antagonist, TN14003. Treatment of mice with TN14003 with bleomycin-induced lung injury significantly attenuated lung fibrosis. Lung tissue from patients with idiopathic pulmonary fibrosis had higher numbers of cells expressing both SDF-1 and CXCR4 than did normal lungs. Our data suggest that the SDF-1/CXCR4 axis is important in the complex sequence of events triggered by bleomycin exposure that eventuates in lung repair. SDF-1 participates in mobilizing bone marrow-derived stem cells, via its receptor CXCR4.     

吉非替尼通过增加Foxo3a活性抑制肺纤维化小鼠上皮-间质转分化

 目的：研究吉非替尼对肺纤维化小鼠转录因子叉头框蛋白O3a(Foxo3a)活性、α-平滑肌肌动蛋白（α-SMA）水平及相关通路的影响,探讨吉非替尼抑制肺上皮-间质转分化的可能机制。方法：将30只SPF级雌性昆明小鼠随机分为3组：对照组（生理盐水气管内雾化）、博来霉素组（博来霉素3 mg/kg溶于100 μL生理盐水气管内雾化）和吉非替尼处理组（博来霉素气管内雾化后,每天吉非替尼20 mg/kg溶于100 μL生理盐水灌胃）。实验第14天收集样本,将小鼠肺组织置于10%中性甲醛固定,石蜡包埋切片后行HE与Masson染色;RT-PCR法检测Foxo3a和α-SMA mRNA表达水平;Western blotting法检测表皮生长因子受体（EGFR）、Akt、Foxo3a和α-SMA蛋白表达水平。结果：吉非替尼处理组小鼠肺组织病理损伤较博来霉素组明显减轻,胶原沉积明显减少,炎症损伤评分及纤维化评分明显下降（均P<0.01）,Foxo3a mRNA表达水平明显升高（P<0.05）,α-SMA mRNA表达水平明显下降（P<0.05）,总Foxo3a蛋白表达增加,但Foxo3a磷酸化水平显著下降(P<0.01),胞核Foxo3a蛋白明显增加（P<0.05）;同时,EGFR和Akt磷酸化水平也显著下降（P<0.01,P<0.05）,上皮-间质转分化标志蛋白α-SMA表达水平明显降低（P<0.05）。结论:吉非替尼抑制博来霉素诱导的肺纤维化,其机制可能与抑制EGFR/Akt通路活化、增强转录因子Foxo3a活性、从而抑制上皮-间质转分化密切相关。     

人脐带间充质干细胞对新生鼠肺纤维化的防治作用**

背景：间充质干细胞因具有自我增殖、多向分化潜能和旁分泌等功能,成为慢性肺部疾病细胞替代治疗的研究热点。 目的：探讨人脐带间充质干细胞对新生大鼠肺纤维化的防治作用及对正常肺发育的影响。 方法：将32只新生2 d SD大鼠随机数字表法均分为PBS对照组、人脐带间充质干细胞组、博来霉素对照组,博来霉素+人脐带间充质干细胞组,后两组腹腔注射博来霉素建立肺纤维化模型,2个细胞组于第7天腹腔注射人脐带间充质干细胞。 结果与结论：博来霉素对照组羟脯氨酸水平最高,肺纤维化最严重,与其他3组比较差异均有显著性意义(P < 0.05);博来霉素干预的两组辐射状肺泡计数和肺组织匀浆中的转化生长因子β1 mRNA表达均低于其他两组(P < 0.05),但血管内皮生长因子mRNA表达升高(P < 0.05),给予细胞治疗后,上述指标均有好转(P < 0.05)。说明人脐带间充质干细胞能过旁分泌增加血管内皮生长因子mRNA表达,下调转化生长因子β1 mRNA水平,对肺纤维化起保护作用。另外,正常鼠腹腔注射脐带间充质干细胞后辐射状肺泡计算无明显变化,证实其对新生鼠肺发育无明显影响。      

依那西普抑制博来霉素诱导的小鼠肺纤维化

 目的：观察肿瘤坏死因子 α(TNF-α)拮抗剂依那西普对博来霉素诱导的肺纤维化小鼠的抑制纤维化作用,并探讨依那西普治疗肺纤维化的可能机制。方法：将45只SPF级雌性昆明小鼠随机分为3组：对照组（气管内雾化生理盐水）、纤维化组（气管内博来霉素3 mg/kg溶于100 μL生理盐水内雾化）和依那西普干预组（气管内雾化博来霉素后,4 mg/kg依那西普溶于100 μL生理盐水内腹腔注射,每3 d注射1次）。处理后第28 d收集样本,小鼠左肺置于10%中性甲醛固定,石蜡包埋切片后行HE与Masson染色;右肺碱水解法检测组织羟脯氨酸(HYP)的含量;酶联免疫法检测血清TNF-α和转化生长因子 β（TGF-β）的含量;提取肺组织总蛋白,Western blotting 检测磷酸化ERK1/2、JNK和p38的表达。结果：依那西普干预组肺组织病理损伤及气道上皮下胶原沉积较纤维化组减轻,肺叶炎症损伤评分和纤维化评分明显下降（均P<0.01）,肺组织HYP含量显著降低（P<0.05）,血清TNF-α 和TGF-β的浓度明显减少（均P<0.01）,肺组织ERK1/2、JNK和p38蛋白的磷酸化水平也显著下降（P<0.01,P<0.05,P<0.01）。结论：依那西普能显著下调TNF-α 和TGF-β的水平,从而抑制ERK1/2、JNK和p38的活化,缓解博来霉素诱导的小鼠肺纤维化病变。     

基于相位衬度成像的小鼠肺肿瘤三维可视化研究

目的肿瘤的早期发现对患者意义重大。鉴于相位衬度成像对于如肺部这样的软组织成像效果显著,本文提出利用相位衬度成像技术,以微米尺度的空间分辨对肿瘤进行成像,并定量分析,早期发现肿瘤。方法在KM小鼠肺部原位接种人肺癌细胞,培育10d后取出肺组织,利用上海同步辐射光源进行相位衬度成像获取投影图像,拍摄结束后对样本进行切片、HE染色,并光学显微镜观察病理切片。然后利用滤波反投影对获取的投影图进行CT断层重建,并通过病理切片对比验证肿瘤位置,最后通过Amira软件进行三维模型的建立。结果重建出了清晰的三维模型,在模型上可以发现小肿瘤结节的存在,并测量得出该肿瘤体积为0．655mm3。结论相位衬度成像对软组织分辨率高,能发现体积较小的肿瘤．对肿瘤的早期发现有一定意义。     

Male sex hormones exacerbate lung function impairment after bleomycin-induced pulmonary fibrosis

The roles of sex hormones as modulators of lung function and disease have received significant attention as differential sex responses to various lung insults have been recently reported. The present study used a bleomycin-induced pulmonary fibrosis model in C57BL/6 mice to examine potential sex differences in physiological and pathological outcomes. Endpoints measured included invasive lung function assessment, immunological response, lung collagen deposition, and a quantitative histological analysis of pulmonary fibrosis. Male mice had significantly higher basal static lung compliance than female mice (P < 0.05) and a more pronounced decline in static compliance after bleomycin administration when expressed as overall change or percentage of baseline change (P < 0.05). In contrast, there were no significant differences between the sexes in immune cell infiltration into the lung or in total lung collagen content after bleomycin. Total lung histopathology scores measured using the Ashcroft method did not differ between the sexes, while a quantitative histopathology scoring system designed to determine where within the lung the fibrosis occurred indicated a tendency toward more fibrosis immediately adjacent to airways in bleomycin-treated male versus female mice. Furthermore, castrated male mice exhibited a female-like response to bleomycin while female mice given exogenous androgen exhibited a male-like response. These data indicate that androgens play an exacerbating role in decreased lung function after bleomycin administration, and traditional measures of fibrosis may miss critical differences in lung function between the sexes. Sex differences should be carefully considered when designing and interpreting experimental models of pulmonary fibrosis in mice.