Relative Lung Weight Research Articles

Influenza H3N2 infection of the collaborative cross founder strains reveals highly divergent host responses and identifies a unique phenotype in CAST/EiJ mice.

BackgroundInfluenza A virus is a zoonotic pathogen that poses a major threat to human and animal health. The severe course of influenza infection is not only influenced by viral virulence factors but also by individual differences in the host response. To determine the extent to which the genetic background can modulate severity of an infection, we studied the host responses to influenza infections in the eight genetically highly diverse Collaborative Cross (CC) founder mouse strains.ResultsWe observed highly divergent host responses between the CC founder strains with respect to survival, body weight loss, hematological parameters in the blood, relative lung weight and viral load. Mouse strain was the main factor with highest effect size on body weight loss after infection, demonstrating that this phenotype was highly heritable. Sex represented another significant main effect, although it was less strong. Analysis of survival rates and mean time to death suggested three groups of susceptibility phenotypes: highly susceptible (A/J, CAST/EiJ, WSB/EiJ), intermediate susceptible (C57BL/6J, 129S1/SvImJ, NOD/ShiLtJ) and highly resistant strains (NZO/HlLtJ, PWK/PhJ). These three susceptibility groups were significantly different with respect to death/survival counts. Viral load was significantly different between susceptible and resistant strains but not between intermediate and highly susceptible strains. CAST/EiJ mice showed a unique phenotype. Despite high viral loads in their lungs, CAST/EiJ mice exhibited low counts of infiltrating granulocytes and showed increased numbers of macrophages in the lung. Histological studies of infected lungs and transcriptome analyses of peripheral blood cells and lungs confirmed an abnormal response in the leukocyte recruitment in CAST/EiJ mice.ConclusionsThe eight CC founder strains exhibited a large diversity in their response to influenza infections. Therefore, the CC will represent an ideal mouse genetic reference population to study the influence of genetic variation on the susceptibility and resistance to influenza infections which will be important to understand individual variations of disease severity in humans. The unique phenotype combination in the CAST/EiJ strain resembles human leukocyte adhesion deficiency and may thus represent a new mouse model to understand this and related abnormal immune responses to infections in humans.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2483-y) contains supplementary material, which is available to authorized users.

Protective effect of C4a against hyperoxic lung injury via a macrophage-dependent but not a neutrophil/lymphocyte-dependent signaling pathway.

Complement anaphylatoxins have been investigated extensively; however, the role of complement anaphylatoxin C4a in hyperoxic lung injury has yet to be investigated. To the best of our knowledge, the present study is the first to demonstrate the role of C4a in hyperoxic lung injury in vitro and in vivo. BALB/c mice were ventilated with 100% oxygen with or without C4a treatment for 36 h. The body weight and the relative lung weight of the mice were determined, along with any morphological changes in the lung. The expression levels of interleukin (IL)-1, IL-6 and tumor necrosis factor-α (TNF-α) were quantified in the lung tissue and bronchoalveolar lavage fluid (BALF) samples by enzyme-linked immunosorbent assay (ELISA) and western blot analysis. The total cell count and the number of macrophages, neutrophils and lymphocytes in the BALF were determined using cytocentrifuge slides and a hemocytometer. Histamine release from total cells in the BALF was also analyzed. The relative mRNA expression levels of CD68, F4/80, CD64, CD19 and CD3 in the murine lung tissue were assessed by reverse transcription-quantitative polymerase chain reaction. The results revealed that hyperoxia induced lung injury and morphological changes, and increased the expression levels of IL-1, IL-6 and TNF-α, histamine release, the number of inflammatory cells, and the expression levels of CD68, F4/80, CD64, CD19 and CD3. The hyperoxia-induced morphological changes and inflammatory reaction were significantly attenuated in mice treated with C4a. Treatment with C4a also attenuated the increase in the total cell count, decreased the number of macrophages in the BALF, and suppressed the elevated mRNA expression levels of CD68 and F4/80 in the lung tissue samples. Conversely, treatment with C4a did not affect the number of neutrophils or lymphocytes in the BALF or the mRNA expression of CD64, CD19 and CD3 in lung tissue. In conclusion, C4a attenuated hyperoxic lung injury via a macrophage-dependent but not a neutrophil/lymphocyte-dependent pathway.

Lung carcinogenicity of inhaled multi-walled carbon nanotube in rats

BackgroundMulti-walled carbon nanotubes (MWCNTs) constitute one of the most promising types of nanomaterials in industry today. With their increasing use, the potential toxicity and carcinogenicity of MWCNT needs to be evaluated in bioassay studies using rodents. Since humans are mainly exposed to MWCNT by inhalation, we performed a 104-week carcinogenicity study using whole-body inhalation exposure chambers with a fibrous straight type of MWCNT at concentrations of 0, 0.02, 0.2, and 2 mg/m3 using male and female F344 rats.ResultsLung carcinomas, mainly bronchiolo-alveolar carcinoma, and combined carcinomas and adenomas were significantly increased in males exposed to 0.2 and 2 mg/m3 MWNT-7 and in females exposed to 2 mg/m3 MWNT-7 compared to the clean air control group. However, no development of pleural mesothelioma was observed. Concentration-dependent toxic effects in the lung such as epithelial hyperplasia, granulomatous change, localized fibrosis, and alteration in BALF parameters were found in MWNT-7 treatment groups of both sexes. There were no MWNT-7-specific macroscopic findings in the other organs, including the pleura and peritoneum. Absolute and relative lung weights were significantly elevated in male rats exposed to 0.2 and 2 mg/m3 MWNT-7 and in all exposed female groups. The lung burdens of MWNT-7 were clearly increased in a concentration-dependent as well as a duration-dependent manner.ConclusionThere is clear evidence that MWNT-7 is carcinogenic to the lungs of male and female F344 rats, however no plural mesothelioma was observed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12989-016-0164-2) contains supplementary material, which is available to authorized users.

Antiproliferative and Chemopreventive effect of Annona muricata Linn. on Ehrlich ascites carcinoma and Benzo[a]pyrene induced lung carcinoma

Annona muricata Linn. also called “Soursop” or “Sharp Sharp” is traditionally used in treatment of cancer. There are many claims that Annona muricata L. can kill cancer cells, since its leaves, seeds and fruits contain active compound called annonaceous acetogenins. This research was aimed to evaluate the antiproliferative and chemopreventive effect of Annona muricata L. leaf extract against Ehrlich ascites carcinoma and benzo[a]pyrene induced lung carcinoma. In Ehrlich ascites carcinoma model, the tumor bearing mice treated with methanol extract of Annona muricata leaves 200 mg/kg and 400 mg/kg once daily orally started 24 h after inoculation significantly reduced the viable cell count. The dose level of 400 mg/kg showed a significant increase in non-viable count with a significant decrease in body weight of animals compared to EAC control animals. The haematological parameters were reverted to more or less normal levels in animals treated with extract 400 mg/kg. In benzo[a]pyrene induced lung cancer model, treatment with extract started 1 week before benzo[a]pyrene induction and continued once daily for 16 weeks, effectively suppressed lung cancer. There was a significant increase in weight gain during experimental period with a significant decrease in relative lung weight and serum cancer marker - carcinoembryonic antigen at the end of experimental period. Gross morphology of lung also appeared near normal to lung of normal animals. Moreover, with reference to lipid peroxidation and antioxidant system, Annona muricata leaf extract decreased the extent of lipid peroxidation with concomitant increase in activities of superoxide dismutase, catalase and reduced glutathione compared to lung cancer bearing untreated animals. It was observed that extract 400 mg/kg showed a significant protection against benzo[a]pyrene induced carcinogenesis. Histological examination of lung tissue too correlated with morphological and biochemical observations. Our data suggest that, the potential anti-proliferative and chemopreventive action of Annona muricata leaves might be due to cytotoxic mechanism against cancer cells in the pathway of apoptosis and inhibition of cell cycle. Furthermore, our in-vitro investigation on extract showed a potent free radical scavenging activity. An additional antioxidant property of Annona muricata leaves might be responsible for chemoprevention by stabilizing all the components of antioxidant defense which were disturbed during benzo[a]pyrene induced oxidative damage.

Comparative Study on the Pulmonary Toxicity of Indium Hydroxide, Indium-Tin Oxide, and Indium Oxide Following Intratracheal Instillations into the Lungs of Rats

ABSTRACTWe studied the pulmonary toxicity of indium hydroxide (In(OH)3), which is produced during a recycling process of indium-tin oxide (ITO), in comparison with that of ITO or indium oxide (In2O3), two raw materials of flat panel displays. One hundred and forty-four male Wistar rats were intratracheally given equivalent doses of 10 mg/kg indium as In(OH)3, ITO, or In2O3 particles, twice a week, for a total of 5 times for 2 weeks. Control rats were given distilled water as a vehicle. After 3 weeks, these rats were serially euthanized, and toxicological effects were determined. Body weight gain was significantly suppressed in the In(OH)3-treated rats compared to that in the control group, but not in the ITO- or In2O3-treated rats. Relative lung weights in all the indium-treated groups significantly increased compared to those in the control group throughout the observation period. Furthermore, lung weights in the In(OH)3 group were significantly higher than those in either the ITO or In2O3 group. Blood indium levels in the In(OH)3-treated rats were much higher, 70- to 200-fold, than those in the In2O3- or ITO-treated rats at each time point. Although the lung indium content decreased gradually during the observation periods, the content in the In(OH)3 group was significantly higher than that in either the ITO or In2O3 group. A histopathological analysis revealed foci indicating a slight to severe pulmonary inflammatory response, including exudation to alveolar spaces, were present in all the indium-treated groups. Interstitial fibrotic proliferation was seen only in the In(OH)3-treated rats. The severity of these lesions in the In(OH)3-treated rats was greater than that in either the ITO- or In2O3-treated rats.The results of our study clearly demonstrated that In(OH)3 particles caused severe pulmonary toxicity when repeated intratracheal instillations were performed in rats. Furthermore, the toxic potency of In(OH)3 in the lung was much higher than that of ITO and In2O3. Accordingly, the toxicity of In(OH)3 particles should be considered in addition to that of ITO and In2O3 particles when indium exposure occurs.

Natakalim improves post-infarction left ventricular remodeling by restoring the coordinated balance between endothelial function and cardiac hypertrophy.

Endothelial dysfunction can lead to congestive heart failure and the activation of endothelial ATP-sensitive potassium (KATP) channels may contribute to endothelial protection. Therefore, the present study was carried out to investigate the hypothesis that natakalim, a novel KATP channel opener, ameliorates post-infarction left ventricular remodeling and failure by correcting endothelial dysfunction. The effects of myocardial infarction were assessed 8 weeks following left anterior descending coronary artery occlusion in male Wistar rats. Depressed blood pressure, cardiac dysfunction, evidence of left ventricular remodeling and congestive heart failure were observed in the rats with myocardial infarction. Treatment with natakalim at daily oral doses of 1, 3 or 9 mg/kg/day for 8 weeks prevented these changes. Natakalim also prevented the progression to cardiac failure, which was demonstrated by the increase in right ventricular weight/body weight (RVW/BW) and relative lung weight, signs of cardiac dysfunction, as well as the overexpression of atrial and brain natriuretic peptide mRNAs. Our results also demonstrated that natakalim enhanced the downregulation of endothelium-derived nitric oxide, attenuated the upregulation of inducible nitric oxide synthase-derived nitric oxide (NO), inhibited the upregulated endothelin system and corrected the imbalance between prostacyclin and thromboxane A2. Overall, our findings suggest that natakalim prevents post-infarction hypertrophy and cardiac failure by restoring the coordinated balance between endothelial function and cardiac hypertrophy.

Targeting complement anaphylatoxin C5a receptor in hyperoxic lung injury in mice.

Receptor binding of complement anaphylatoxin C5a results in proinflammatory activation of numerous diseases, but the role of receptor-mediated action during hyperoxic lung injury has, to the best of our knowledge, not yet been investigated. The contribution of the C5a receptor (C5aR) to hyperoxic lung injury in mice was investigated in this study. The effect of C5aR on hyperoxic lung injury in Balb/c mice was examined employing a C5aR antagonist (C5aRA). The mice were ventilated with 100% oxygen for 36 h with or without the administration of C5aRA. C5aR expression levels in non-treated or 100% oxygen-treated mice were assessed by reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry. The body weight and the relative lung weight of the mice, and the morphological changes in the lung were then determined. The total cell counts and the number of macrophages, neutrophils and lymphocytes in bronchoalveolar lavage fluid (BALF) were determined using cytocentrifuge slides and a hemocytometer. The levels of interleukin-6 (IL-6), monocyte chemotactic protein (MCP-1) and tumor necrosis factor-α (TNF-α) in BALF and the myeloperoxidase (MPO) activity in the lung tissue were measured by enzyme-linked immunosorbent assay. The relative levels of CD68 and F4/80 messenger ribonucleic acid (mRNA) expression in the lung tissue were detected by RT-PCR. The TNF-α, IL-6 and MCP-1 protein expression levels in the lung tissue were assessed by western blot analysis. The results revealed hyperoxia-induced morphological changes, lung injury and increased expression levels of C5aR in lung tissue. The hyperoxia-induced increases in the total cell count and the number of macrophages, neutrophils and lymphocytes in the BALF were all significantly reduced in the mice receiving C5aRA. Treatment with C5aRA also attenuated the morphological changes and reduced MPO activity, and CD68 and F4/80 mRNA expression levels in the lung tissue, as well as the levels of IL-6, MCP-1 and TNF-α in BALF and lung tissue. In conclusion, C5a-C5aR action accelerated hyperoxia-induced lung injury, but this hyperoxic lung injury was attenuated by treatment with C5aRA.

Effects of dietary Crotalaria pallida seeds on the health and performance of laying hens and evaluation of residues in eggs

The effect of three dietary concentrations of Crotalaria pallida (C. pallida) seeds (0, 1, 2, and 3% w/w) of their normal diet were investigated in commercial laying hens during a 35 day feeding trial. All concentrations of C. pallida decreased body weight and feed intake (P < 0.05). Egg mass production and average egg weight were decreased by feeding of ≥2% C. pallida seeds (P < 0.05). All concentrations of C. pallida increased relative lung weight and serum activity of ALT, AST and LDH (P < 0.05); 3% C. pallida seeds decreased liver weight (P < 0.05). Analysis of the C. pallida seeds for dehydropyrrolizidine alkaloid content detected usaramine and its N-oxide at a total alkaloid concentration of 0.18% (dry weight). Usaramine was also detected in the eggs of all hens fed C. pallida seeds.

121 Anti-Pseudomonas aeruginosa antibodies and microbiological outcome in not chronically infected patients

Objectives: The present study explored the possible protective effect of IgY on PA lung infection in vivo. Methods: In vivo model of acute lung infection: Balb/c mice were anaesthetized with isoflurane and PAO1 vaccine strain ± specific (S-IgY) or control (C-IgY) was inoculated intranasally. Mice were sacrificed after 2, 6 and 24h and lungs removed aseptically, weighted and suspended in PBS. A blinded observer engaged a clinical scoring system (0−5) of the mice. Lungs were homogenized, serially diluted and cultured on Conradi-Drigalski medium for estimation of bacterial load. Results: Relative lung weight: Lung weights in the S-IgY treated group were significantly reduced 24h post-infection compared to PBS controls (p< 0.03). No significant difference between C-IgY and PBS groups were observed. Clinical symptom score: The clinical score was significantly lower in the S-IgY group compared to controls after 6h (C-IgY: p< 0.05, PBS: p< 0.05). After 24h the clinical score in the S-IgY was reduced additionally compared to controls (PBS: p< 0.002, C-IgY: p< 0.04). No significant difference between C-IgY and PBS groups were observed. Quantitative bacteriology: The bacterial load of S-IgY treated mice was significantly reduced 2h post-infection compared to PBS group (p< 0.02) and C-IgY (p< 0.03) and further reduced 6h post-infection compared to both control groups (PBS: p< 0.0001, C-IgY: p< 0.03). After 24h the lung bacteriology in S-IgY treated mice was reduced by 2 logs compared to PBS (p< 0.0001) and C-IgY (p< 0.0002) groups. Conclusion: The present results imply that anti-PA IgY antibodies protects against PA lung infection due to readily bacterial clearance in the airways.

A nonhuman primate toxicology and immunogenicity study evaluating aerosol delivery of AERAS-402/Ad35 vaccine

Bacille Calmette-Guérin (BCG), the only licensed vaccine for the prevention of tuberculosis (TB), provides only limited protection against certain forms of Mycobacterium tuberculosis (Mtb) infection. While infection with Mtb can be treated with antibiotics, the therapy is expensive, toxic, and requires several months for treatment. In addition, the emergence of drug resistant strains limits the impact of antibiotics and underlines the importance of developing a more effective vaccine to control this disease. Given that pulmonary TB is the most common form of the disease, a vaccine capable of inducing lung-resident immunity may be advantageous for combating this infection. New advances in pulmonary delivery make this route of vaccination feasible and affordable. Here, we evaluate the safety and immunogenicity of an aerosolized Ad35-based vaccine, AERAS-402, delivered to the lungs in nonhuman primates as part of a GLP acute and chronic toxicology and safety study. In this study, animals received three high doses (1 x 1011 vp) of AERAS-402 by inhalation via a nebulizer at 1-week intervals. Aerosol delivery of AERAS-402 resulted in an increase in relative lung weights as well as microscopic findings in the lungs, mediastinal lymph nodes, bronchus-associated lymphatic tissue, and the naso-oropharynx that were consistent with the induction of an immune response during the acute phase. These findings resolved by the chronic phase and were considered to be non-adverse. Furthermore, we observed transient vaccine-specific immune responses in the peripheral blood as well as sustained high-level polyfunctional CD4+ and CD8+ T cell responses in the bronchoalveolar lavage fluid of vaccinated nonhuman primates. The data suggest that pulmonary delivery of Ad35-based vaccines can be safe and can induce potent lung-resident immunity.

The Effects of 17-Methoxyl-7-Hydroxy-Benzene-Furanchalcone on the Pressure Overload-Induced Progression of Cardiac Hypertrophy to Cardiac Failure

We investigated the effects of 17-methoxyl-7-hydroxy-benzene-furanchalcone (MHBFC), which was isolated from the roots of Millettia pulchra (Benth.) Kurz var. Laxior (Dunn) Z.Wei (Papilionaceae) (MKL), on the progression of cardiac hypertrophy to failure in a rat model of abdominal aortic banding (AAB)-induced pressure overloading. Endothelial dysfunction is central to pressure overload-induced cardiac hypertrophy and failure. It would be useful to clarify whether MHBFC could prevent this dysfunction. The effects of pressure overload were assessed in male Sprague–Dawley rats 6 weeks after AAB using the progression of cardiac hypertrophy to heart failure as the endpoint. The AAB-treated rats exhibited a greater progression to heart failure and had significantly elevated blood pressure, systolic and diastolic cardiac dysfunction, and evidence of left ventricular hypertrophy (LVH). LVH was characterized by increases in the ratios of heart and left ventricular weights to body weight, increased myocyte cross-sectional areas, myocardial and perivascular fibrosis, and elevated cardiac hydroxyproline. These symptoms could be prevented by treatment with MHBFC at daily oral doses of 6 and 12 mg/kg for 6 weeks. The progression to cardiac failure, which was demonstrated by increases in relative lung and right ventricular weights, cardiac function disorders and overexpression of atrial natriuretic peptide (ANP) mRNA, could also be prevented. Furthermore, MHBFC partialy rescued the downregulated nitric oxide signaling system, whereas inhibited the upregulated endothelin signaling system, normalizing the balance between these two systems. MHBFC protected the endothelium and prevented the pressure overload-induced progression of cardiac hypertrophy to cardiac failure.

Temperature and CO2 during the hatching phase. I. Effects on chick quality and organ development

The objective of this study was to investigate the effect of eggshell temperature (EST) and carbon dioxide (CO2) concentration during only the hatching phase on embryonic development and chick quality. Three batches of eggs were incubated at an EST of 37.8°C until d of incubation (E) 19. From E19, embryos were incubated at low (36.7°C), normal (37.8°C), or high (38.9°C) EST and at low (0.2%) or high (1%) CO2 concentration. Organ growth and embryo and chick quality were measured at E19, internal pipping (IP), hatch, and 12 h after hatch. A few interactions between EST and CO2 were found at IP, hatch, and 12 h after hatch, but all of these interactions were temporary and in most cases weak. High EST resulted in a lower relative heart weight compared with low ( = 0.05) and normal EST ( = 0.06) at IP, compared with low ( = 0.11) and normal EST ( = 0.08) at hatch, and compared with low ( = 0.11) and normal EST ( = 0.08) at 12 h after hatch. At hatch, high EST resulted in a lower YFBM compared with low EST ( = 0.65). At 12 h after hatch, high EST resulted in a lower relative liver weight compared with low EST ( = 0.12). At low EST, greater relative intestinal weight was found compared with normal ( = 0.41) and high EST ( = 0.37). The effect of CO2 solely was found at 12 h after hatch at which a higher relative heart weight ( = 0.05) and a higher relative lung weight ( = 0.0542) was found at high CO2 compared with low CO2. High EST during only the hatching phase negatively affected chick development, mainly expressed by the lower relative heart weight at IP, hatch, and 12 h after hatch and lower YFBM at hatch. The resolving effect of CO2 demonstrates that CO2 only seem to have a temporary effect during the hatching phase.

Hypoinnervation is an early event in experimental myocardial remodelling induced by pressure overload

Structural and functional remodelling of cardiomyocytes, capillaries and cardiac innervation occurs in left ventricular hypertrophy (LVH) and heart failure (HF) in response to pressure-induced overload. However, the onset, time course and the extent of these morphological alterations remain controversial. In the present study, we tested the hypothesis that the progression from hypertrophy to HF is accompanied by changes in the innervation (hyper- or hypoinnervation). Left ventricles of wild-type murine hearts subjected to pressure overload-induced hypertrophy by transverse aortic constriction (TAC) were investigated by morphometric and design-based stereological methods at 1 and 4 weeks after TAC and compared with sham-operated mice. Mice developed compensated LVH at 1 week and typical signs of HF, such as left ventricular dilation, reduced ejection fraction and increased relative lung weight at 4 weeks post-TAC. At the (sub-)cellular level, cardiomyocyte myofibrillar and mitochondrial volume increased progressively in response to mechanical overload. The total length of capillaries was not significantly increased after TAC, indicating a misrelationship between the cardiomyocyte and the capillary compartment. The myocardial innervation decreased already during the development of LVH and did not significantly decrease further during the progression to HF. In conclusion, our study suggests that early loss of myocardial innervation density and increased heterogeneity occur during pressure overload-induced hypertrophy, and that these changes appear to be independent of cardiomyocyte and capillary remodelling.

Comparison of Biological Responses in Rats Under Various Cigarette Smoke Exposure Conditions

A variety of exposure regimens of cigarette smoke have been used in animal models of lung diseases. In this study, we compared biological responses of smoke exposure in rats, using different smoke concentrations (wet total particulate matter [WTPM]), daily exposure durations, and total days of exposure. As a range-finding acute study, we first compared pulmonary responses between SD and F344 strains after a single nose-only exposure to mainstream cigarette smoke or LPS. Secondly, F344 rats were exposed to cigarette smoke for 2 or 13 weeks under the comparable daily exposure dose (WTPM concentration x daily exposure duration; according to Haber’s rule) but at a different WTPM concentration or daily exposure duration. Blood carboxylhemoglobin was increased linearly to the WTPM concentration, while urinary nicotine plus cotinine value was higher for the longer daily exposure than the corresponding shorter exposure groups. Gamma glutamyl transferase activity in bronchoalveolar lavage fluid (BALF) was increased dose dependently after 2 and 13 weeks of cigarette smoke exposure, while the neutrophil content in BALF was not increased notably. Smoke-exposed groups showed reduced body weight gain and increased relative lung and heart weights. While BALF parameters and the relative lung weights suggest pulmonary responses, histopathological examination showed epithelial lesions mainly in the upper respiratory organs (nose and larynx). Collectively, the results indicate that, under the employed study design, the equivalent daily exposure dose (exposure concentration x duration) induces equivalent pulmonary responses in rats.

Long-term Pulmonary Responses to Quadweekly Intermittent Intratracheal Spray Instillations of Magnetite (Fe&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;) Nanoparticles for 52 Weeks in Fischer 344 Rats

Information about potential risks of iron nanomaterials is still limited, while a wide variety of applications are expected. We recently reported acute phase responses of male and female Fischer 344 rats after a single intratracheal spray instillation of Fe3O4 nanoparticles (magnetite), clearly showing dose-dependent pulmonary inflammatory changes (Tada et al., J Toxicol Pathol 25, 233–239, 2012). The present study assessed long-term responses of male and female Fischer 344 rats to multiple administrations of magnetite. Ten-week-old male and female Fischer 344 rats (n=20/group) were exposed to a total of 13 quadweekly intermittent intratracheal spray instillations of magnetite during the experimental period of 52 weeks, at doses of 0, 0.2 (low), 1.0 (medium) and 5.0 (high-dose) mg/kg body weight per administration. Absolute and relative lung weights of the high-dose group were significantly higher than those of the control group. Macroscopically, slight enlargement and scattered black patches were recognized in the lungs and the lung-associated lymph nodes of the high-dose group. Histopathologically, infiltration of macrophages phagocytosing magnetite (all dose groups) and of chronic inflammatory cells (medium- and high-dose males and high-dose females), alveolar bronchiolization and granuloma (high-dose group) were observed. In addition, alveolar hyperplasias were observed in some rats of the high-dose group, and cytoplasmic overexpression of β-catenin protein was immunohistochemically found in such lesions. The present results clearly show that instilled magnetite causes chronic inflammatory responses in the lung. These responses occur in a dose-dependent manner without apparent differences among sexes

Pulmonary vascular remodeling in broiler and Leghorn chickens after unilateral pulmonary artery occlusion

Morphological and physiological responses to unilateral pulmonary artery occlusion (PAO) were evaluated in male broiler (B) and Leghorn (L) chickens. All birds were fed a diet containing 3,200 kcal of ME/kg of feed and 23% CP. Broilers (18-21 d old; 507 ± 40 g of BW) and L (61-64 d old, 861 ± 87 g of BW) had surgical PAO (n = 40 each strain) or were sham-operated (SHAM; n = 40 each strain). Hematocrit (%, Hc), relative lung weight (wet right + left lung weight/BW × 100), right ventricle to total ventricle weight ratio (RV/TV), and resistance pulmonary arterioles (RPA) thickness were measured in 6 chickens per group one day presurgery, and at 7 and 14 d postsurgery. Data were analyzed using one-way ANOVA. Relative lung weight was higher in L-chickens than in B-chickens at all sampling times. There were no differences in Hc between B and L presurgery, but at d 7 and 14, L-PAO chickens had the highest Hc (35 ± 1.4 and 40 ± 1.9, respectively); the B-SHAM had a lower Hc (28 ± 1.2, and 29 ± 1.0) than the L-SHAM (32 ± 1.2 and 34 ± 1.1) and the B-PAO (32 ± 1.2 and 34 ± 2.0) chickens, with no differences between L-SHAM and B-PAO. The RV/TV ratio was highest in the B-PAO at d 7 and d 14, with no differences among the other groups. The B-PAO chickens had the thickest RPA at 7 d and 14 d postsurgery than the rest of the groups, whereas B had thicker RPA than L at presurgery. Broilers had a lower ventilation capacity than L, and after PAO they developed right ventricular hypertrophy and small arteriole remodeling, whereas the L-PAO showed a higher degree of hypoxemia (high Hct), but without changes in RV/TV ratios or small arterial remodeling, suggesting that L-chickens had a better pulmonary arterial vasodilation even after chronic increases in blood flow through a single lung.

Consecutive CT in vivo lung imaging as quantitative parameter of influenza vaccine efficacy in the ferret model

Preclinical vaccine efficacy studies are generally limited to certain read out parameters such as assessment of virus titers in swabs and organs, clinical signs, serum antibody titers, and pathological changes. These parameters are not always routinely applied and not always scheduled in a logical standardized way. We used computed tomography (CT) imaging as additional and novel read out parameter in a vaccine efficacy study by quantifying alterations in aerated lung volumes in ferrets challenged with the 2009 pandemic A/H1N1 influenza virus.Vaccination protected from marked variations in aerated lung volumes compared to naive controls. The vaccinated group showed a daily gradual mean reduction with a maximum of 7.8%, whereas the controls showed a maximum of 14.3% reduction. The pulmonary opacities evident on CT images were most pronounced in the placebo-treated controls, and corresponded to significantly increased relative lung weights at necropsy.This study shows that consecutive in vivo CT imaging allows for a day to day read out of vaccine efficacy by quantification of altered aerated lung volumes.

Comparison of Temporal and Spatial Dynamics of Seasonal H3N2, Pandemic H1N1 and Highly Pathogenic Avian Influenza H5N1 Virus Infections in Ferrets

Humans may be infected by different influenza A viruses—seasonal, pandemic, and zoonotic—which differ in presentation from mild upper respiratory tract disease to severe and sometimes fatal pneumonia with extra-respiratory spread. Differences in spatial and temporal dynamics of these infections are poorly understood. Therefore, we inoculated ferrets with seasonal H3N2, pandemic H1N1 (pH1N1), and highly pathogenic avian H5N1 influenza virus and performed detailed virological and pathological analyses at time points from 0.5 to 14 days post inoculation (dpi), as well as describing clinical signs and hematological parameters. H3N2 infection was restricted to the nose and peaked at 1 dpi. pH1N1 infection also peaked at 1 dpi, but occurred at similar levels throughout the respiratory tract. H5N1 infection occurred predominantly in the alveoli, where it peaked for a longer period, from 1 to 3 dpi. The associated lesions followed the same spatial distribution as virus infection, but their severity peaked between 1 and 6 days later. Neutrophil and monocyte counts in peripheral blood correlated with inflammatory cell influx in the alveoli. Of the different parameters used to measure lower respiratory tract disease, relative lung weight and affected lung tissue allowed the best quantitative distinction between the virus groups. There was extra-respiratory spread to more tissues—including the central nervous system—for H5N1 infection than for pH1N1 infection, and to none for H3N2 infection. This study shows that seasonal, pandemic, and zoonotic influenza viruses differ strongly in the spatial and temporal dynamics of infection in the respiratory tract and extra-respiratory tissues of ferrets.

Subacute Pulmonary Toxicity of Copper Indium Gallium Diselenide Following Intratracheal Instillations into the Lungs of Rats

The aim of this study was to clarify the pulmonary toxicity of copper indium gallium diselenide (CIGS) solar cells on 62 8-wk-old rats. Male Wistar rats were given 0.5, 5 or 50 mg/kg of CIGS particles, intratracheally, 3 times for a week. Control rats were given vehicle, distilled water, only. These rats were euthanized 0, 1 or 3 wk after the final instillation serially, and toxicological effects were determined. None of the CIGS-treated groups exhibited suppression of body weight gain compared with the control group. The relative lung weight in the CIGS 5 mg/kg-treated and 50 mg/kg-treated groups were significantly increased compared with that in the control group throughout the observation period. Although serum copper (Cu) and selenium (Se) concentrations were not affected by instillations of CIGS particles, the indium (In) levels increased with the passage of time in the CIGS 5 mg/kg-treated and 50 mg/kg-treated groups. However, the serum gallium (Ga) levels decreased in the CIGS 50 mg/kg-treated group from 0 to 3 wk. The content of each metal in the lung increased depending on the dose instilled and was constant during observation periods. Histopathologically, foci of slight to severe pulmonary inflammatory response and exudation were present among all the CIGS-treated groups, and the severity of these lesions worsened with the passage of time. The present results clearly demonstrate that CIGS particles caused subacute pulmonary toxicity and that dissolution of CIGS particles in the lung was considerably slow when repeated intratracheal instillations were given to rats.

Ventilator-induced Lung Injury Is Mediated by the NLRP3 Inflammasome

The innate immune response is important in ventilator-induced lung injury (VILI) but the exact pathways involved are not elucidated. The authors studied the role of the intracellular danger sensor NLRP3 inflammasome. NLRP3 inflammasome gene expression was analyzed in respiratory epithelial cells and alveolar macrophages obtained from ventilated patients (n = 40). In addition, wild-type and NLRP3 inflammasome deficient mice were randomized to low tidal volume (approximately 7.5 ml/kg) and high tidal volume (approximately 15 ml/kg) ventilation. The presence of uric acid in lung lavage, activation of caspase-1, and NLRP3 inflammasome gene expression in lung tissue were investigated. Moreover, mice were pretreated with interleukin-1 receptor antagonist, glibenclamide, or vehicle before start of mechanical ventilation. VILI endpoints were relative lung weights, total protein in lavage fluid, neutrophil influx, and pulmonary and systemic cytokine and chemokine concentrations. Data represent mean ± SD. Mechanical ventilation up-regulated messenger RNA expression levels of NLRP3 in alveolar macrophages (1.0 ± 0 vs. 1.70 ± 1.65, P less than 0.05). In mice, mechanical ventilation increased both NLRP3 and apoptosis-associated speck-like protein messenger RNA levels, respectively (1.08 ± 0.55 vs. 3.98 ± 2.89; P less than 0.001 and 0.95 ± 0.53 vs. 6.0 ± 3.55; P less than 0.001), activated caspase-1, and increased uric acid levels (6.36 ± 1.85 vs. 41.9 ± 32.0, P less than 0.001). NLRP3 inflammasome deficient mice displayed less VILI due to high tidal volume mechanical ventilation compared with wild-type mice. Furthermore, treatment with interleukin-1 receptor antagonist or glibenclamide reduced VILI. Mechanical ventilation induced a NLRP3 inflammasome dependent pulmonary inflammatory response. NLRP3 inflammasome deficiency partially protected mice from VILI.