Evaluation of the dose-response and fate in the lung and pleura of chrysotile-containing brake dust compared to TiO2, chrysotile, crocidolite or amosite asbestos in a 90-day quantitative inhalation toxicology study - Interim results Part 2: Histopathological examination, Confocal microscopy and collagen quantification of the lung and pleural cavity.

The interim results from this 90-day multi-dose, inhalation toxicology study with life-time post-exposure observation has shown an important fundamental difference in persistence and pathological response in the lung between brake dust derived from brake-pads manufactured with chrysotile, TiO2 or chrysotile alone in comparison to the amphiboles, crocidolite and amosite asbestos. In the brake dust exposure groups no significant pathological response was observed at any time. Slight macrophage accumulation of particles was noted. Wagner-scores, were from 1 to 2 (1 = air-control group) and were similar to the TiO2 group. Chrysotile being biodegradable, shows a weakening of its matrix and breaking into short fibers & particles that can be cleared by alveolar macrophages and continued dissolution. In the chrysotile exposure groups, particle laden macrophage accumulation was noted leading to a slight interstitial inflammatory response (Wagner-score 1-3). There was no peribronchiolar inflammation and occasional very slight interstitial fibrosis. The histopathology and the confocal analyses clearly differentiate the pathological response from amphibole asbestos, crocidolite and amosite, compared to that from the brake dust and chrysotile. Both crocidolite and amosite induced persistent inflammation, microgranulomas, and fibrosis (Wagner-scores 4), which persisted through the post exposure period. The confocal microscopy of the lung and snap-frozen chestwalls quantified the extensive inflammatory response and collagen development in the lung and on the visceral and parietal surfaces. The interim results reported here, provide a clear basis for differentiating the effects from brake dust exposure from those following amphibole asbestos exposure. The subsequent results through life-time post-exposure will follow.

Evaluation of the exposure, dose-response and fate in the lung and pleura of chrysotile-containing brake dust compared to TiO2, chrysotile, crocidolite or amosite asbestos in a 90-day quantitative inhalation toxicology study - Interim results Part 1: Experimental design, aerosol exposure, lung burdens and BAL.

This 90-day repeated-dose inhalation toxicology study of brake-dust (BD) (brakes manufactured with chrysotile) in rats provides a comprehensive understanding of the biokinetics and potential toxicology in the lung and pleura. Exposure was 6 h/d, 5d/wk., 13wks followed by lifetime observation (~20 % survival). Control groups included a particle control (TiO2), chrysotile, commercial crocidolite and amosite asbestos. Aerosol fiber distributions of the chrysotile, crocidolite and amosite were similar (fibers L > 20 µm/cm3: chrysotile-Low/High 29/72; crocidolite 24; amosite 47 fibers/cm3; WHO-fibers/cm3: chrysotile-Low/High 119/233; crocidolite 181; amosite 281 fibers/cm3). The number of particles/cm3 in the BD was similar to that in the chrysotile, crocidolite & amosite exposures (BD 470-715; chrysotile 495-614; crocidolite 415; amosite 417 particles/cm3). In the BD groups, few fibers L > 20 µm were observed in the lungs at the end of exposure and no fibers L > 20 µm at 90d post exposure. In the chrysotile groups, means of 204,000 and 290,000 fibers(L > 20 µm)/lung were measured at 89d. By 180d, means of 1 and 3.9 fibers were counted on the filter corresponding to 14,000 and 55,000 fibers(L > 20 µm)/lung. In the crocidolite and amosite groups mean lung concentrations were 9,055,000 and 11,645,000 fibers(L > 20 µm)/lung at 89d. At 180d the means remained similar with 8,026,000 and 11,591,000 fibers(L > 20 µm)/lung representing 10-13% of the total lung fibers. BAL determined the total number of macrophages, lymphocytes, neutrophils, eosinophils, epithelial-cells and IL-1 beta, TNF-alpha and TGF-beta. At the moderate aerosol concentrations used in this study, neutrophil counts increased ~5 fold in the amphibole asbestos exposure groups. All other groups and parameters showed no important differences at these exposure concentrations. The exposure and lung burden results provide a sound basis for assessing the potential toxicity of the brake dust in comparison to the TiO2 particle control and the chrysotile, crocidolite and amosite asbestos control groups. The BAL results provide an initial indication of the differential response. Part 2 presents the presentation and discussion of the histopathological and confocal microscopy findings in this study through 90 days post exposure.

Retraction notice to "Haemodynamic effects of the phosphodiesterase inhibitor enoximone in comparison with dobutamine in esmolol-treated cardiac surgery patients" [Br J Anaesth 64 (1990) 611-6].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief, Professor Hugh Hemmings, based on the recommendations of Justus-Liebig-University Giessen following an internal review of research conducted by Joachim Boldt at the University. This is further described in 'Further Retractions of Articles by Joachim Boldt', https://doi.org/10.1016/j.bja.2020.02.024.

Blueberries as an additive to increase the survival of Lactobacillus johnsonii N6.2 to lyophilisation.

Effective cultivation methods, total cost, and biomass preservation are key factors that have a significant impact on the commercialisation and effectiveness of probiotics, such as Lactobacillus. Sugar polymers, milk and whey proteins have been suggested as good additives for industrial preparations. Alternative compounds, such as phytophenols, are a more attractive option, given their potential benefits to human health. The overall goal of this study was to determine if the addition of blueberry phytophenols improves the survival of Lactobacillus johnsonii N6.2 during the freeze-drying process. The addition of blueberry aqueous extract (BAE) stimulated the growth of L. johnsonii under aerobic conditions and improved the stationary phase survival of the bacteria. Furthermore, the addition of BAE to the culture media improved the endurance of L. johnsonii N6.2 to freeze-drying stress, as well as to storage at 4 °C for up to 21 weeks. Moreover, blueberry extract performed more effectively as a lyophilising additive compared to skim milk and microencapsulation with whey protein/sodium alginate. In sum, this study demonstrates that BAE is an effective additive to increase the growth and survival of L. johnsonii N6.2 when added to the culture medium and/or used as a lyophilising preservative. Moreover, BAE or other polyphenols sources might likely enhance growth and increase survival of more probiotic lactic acid bacterial strains.

Raised plasma soluble P-selectin in peripheral arterial occlusive disease enhances leukocyte adhesion.

Raised levels of soluble P-selectin (sP-selectin) have been reported in the plasma of patients with vascular diseases; however, the functional importance of this ligand remains unclear. In this study we have examined a potential role for plasma sP-selectin in regulating neutrophil adhesion in patients with peripheral arterial occlusive disease (PAOD). Patients with PAOD had significantly higher levels of sP-selectin (mean+/-SD: 73.3+/-13.0 versus 16.7+/-6.4 ng/mL) and enhanced whole blood leukocyte adhesion to platelets under shear. To examine whether the raised sP-selectin levels can directly influence leukocyte adhesion, isolated neutrophils were incubated with plasma from PAOD patients before and after immunodepletion of sP-selectin. Neutrophil adhesion to fibrinogen increased 2-fold following incubation with PAOD plasma, which was abrogated on sP-selectin immunodepletion. We subsequently demonstrated that recombinant sP-selectin dose-dependently (75 to 250 ng/mL) increased leukocyte adhesion to fibrinogen and platelet monolayers. This increase was PSGL-1 and Src kinase-dependent and correlated with an increase in sP-selectin-mediated Mac-1 activation. sP-selectin-stimulated neutrophil adhesion to platelet monolayers was inversely correlated with shear, such that at low shear (50 s(-1)) a 92.7%+/-15.7 increase in adhesion was observed decreasing to 38.5%+/-11.9 at 150 s(-1) and 10.1%+/-7.4 at 300 s(-1). These studies suggest a potentially important role for sP-selectin in modulating neutrophil adhesion in patients with PAOD, particularly at sites of low shear, where it raises the possibility that raised plasma sP-selectin levels may enhance leukocyte recruitment to vascular injury and promote disease progression.

Lactobacillus johnsonii N6.2 diminishes caspase-1 maturation in the gastrointestinal system of diabetes prone rats.

The cells of the gastrointestinal (GI) epithelium are the first to contact the microbiota and food components. As a direct consequence of this, these cells are the first line of defence and key players in priming the immune response. One of the first responses against GI insults is the formation of the inflammasome, a multiprotein complex assembled in response to environmental threats. The formation of the inflammasome regulates caspase-1 by cleaving it into its active form. Once activated, caspase-1 can cleave interleukin-1ß (IL-1ß), which promotes adaptive and humoral immunity. Some strains, like Lactobacillus johnsonii N6.2, are able to modulate the biosynthesis of important host metabolites mediating inflammation. Of these metabolites are the pro-inflammatory kynurenines. L. johnsonii N6.2 is able to downregulate kynurenines biosynthesis via a redox active mechanism negatively affecting indoleamine 2,3-dioxygenase activity. In this study, we evaluated the effects of L. johnsonii N6.2 combined with the natural antioxidant and anti-inflammatory molecule rosmarinic acid (RA). Inflammasome assembly and the kynurenine pathway were evaluated in GI samples of BioBreeding diabetes-prone (BB-DP) rats. In this work, BB-DP rats were fed daily with RA, L. johnsonii N6.2; or both combined. The transcriptional rate and proteins levels of inflammasome and kynurenine pathway components in ileum tissue were evaluated. Elevated levels of pro-caspase-1 were observed in rats fed with L. johnsonii, while RA had no effect on pro-caspase-1 expression. Western blot assays demonstrated that L. johnsonii fed rats showed lower levels of mature caspase-1, when compared to the other treatments. Furthermore, IL-1ß maturation followed a similar pattern across the treatments. Differences were also observed between treatments in expression levels of key enzymes in the kynurenine pathway. These findings support the role of L. johnsonii in modulating the assembly of the inflammasome as well as some steps of the pro-inflammatory kynurenine pathway.

Study of the pharmacokinetic interaction between simvastatin and prescription omega-3-acid ethyl esters.

The coadministration of prescription omega-3-acid ethyl esters (P-OM3) with a statin may present a treatment option for patients with mixed hyperlipidemia. This open-label, randomized, 2-way crossover, drug-drug interaction study evaluated the impact of P-OM3 capsules on plasma simvastatin pharmacokinetics in 24 healthy volunteers. Under fasted conditions, 80 mg simvastatin was administered with or without 4 g P-OM3 for two 14-day periods. After 14 days of dosing to achieve steady state, no significant differences were found in either the extent (AUC(tau)) or rate (Cmax) of exposure to simvastatin or its major beta-hydroxy metabolite after coadministration of P-OM3 with simvastatin compared with administration of simvastatin alone. At steady state, the coadministration of P-OM3 capsules did not appear to affect the pharmacokinetics of simvastatin tablets. The combination of P-OM3 capsules and simvastatin appeared to be well tolerated.

High-resolution intravascular magnetic resonance imaging: monitoring of plaque formation in heritable hyperlipidemic rabbits.

BACKGROUND: The individual makeup of atherosclerotic plaque has been identified as a dominant prognostic factor. With the use of an intravascular magnetic resonance (MR) catheter coil, we evaluated the effectiveness of high-resolution MR in the study of the development of atherosclerotic lesions in heritable hyperlipidemic rabbits. METHODS AND RESULTS: Sixteen hyperlipidemic rabbits were investigated at the ages of 6, 12, 24, and 36 months. The aorta was studied with digital subtraction angiography and high-resolution MR with the use of a surface coil and an intravascular coil that consisted of a single-loop copper wire integrated in a 5F balloon catheter. Images were correlated with histological sections regarding wall thickness, plaque area, and plaque components. Digital subtraction angiography revealed no abnormalities in the 6- and 12-month-old rabbits and only mild stenoses in the 24- and 36-month-old rabbits. High-resolution imaging with surface coils resulted in an in-plane resolution of 234x468 microm. Delineation of the vessel wall was not possible in younger rabbits and correlated only poorly with microscopic measurements in the 36-month-old rabbits. Intravascular images achieved an in-plane resolution of 117x156 microm. Increasing thickness of the aortic wall and plaque area was observed with increasing age. In the 24- and 36-month-old animals, calcification could be differentiated from fibrous and fatty tissue on the basis of the T2-fast spin echo images, as confirmed by histological correlation. CONCLUSIONS: Atherosclerotic evolution of hyperlipidemic rabbits can be monitored with high-resolution intravascular MR imaging. Image quality is sufficient to determine wall thickness and plaque area and to differentiate plaque components.

Nitrofen induces a redox-dependent apoptosis associated with increased p38 activity in P19 teratocarcinoma cells.

Nitrofen is a diphenyl ether herbicide that produces a spectrum of fetal abnormalities in rodents. To characterize the molecular mechanisms of nitrofen-mediated birth defects at the cellular level, we explored its effects on undifferentiated P19 teratocarcinoma cells. Nitrofen induces a time-dependent cell death of P19 cells that is associated with increases in TUNEL-positivity and caspase-3 cleavage suggesting that nitrofen induces P19 cell apoptosis. In addition, the increase in TUNEL-positive cells was inhibited with zVAD-fmk, suggesting that nitrofen induces a caspase-dependent apoptosis. Nitrofen treatment was associated with increased p38 MAP kinase activity, though pretreatment of cells with multiple p38 inhibitors did not affect nitrofen-mediated caspase-3 cleavage, suggesting caspase-3 cleavage is p38-independent. Nitrofen induced a dose-dependent increase in reactive oxygen species (ROS), which was accompanied by a decrease in the ratio of reduced/oxidized glutathione, indicating that nitrofen alters the cellular redox state of these cells. Furthermore, pretreatment of cells with N-acetyl cysteine gave a dose- and time-dependent reduction of caspase-3 cleavage, supporting the observations that caspase-3 cleavage is cell-redox-dependent. Therefore, nitrofen induces P19 cell apoptosis that is cell-redox-dependent and is associated with increases in p38 activity and ROS and may play a role in nitrofen-mediated birth defects.

Human napsin A: expression, immunochemical detection, and tissue localization.

A novel aspartic proteinase, called napsin, has recently been found in human and mouse. Due to high similarity with cathepsin D a structural model of human napsin A could be built. Based on this model a potential epitope SFYLNRDPEEPDGGE has been identified, which was used to immunize rabbits. The resulting antibody was employed in monitoring the expression of recombinant human napsin A in HEK293 cell line. Western blot analysis confirmed the specificity of the antibody and showed that human napsin A is expressed as a single chain protein with the molecular weight of approximately 38 kDa. Immunohistochemical studies revealed high expression levels of napsin A in human kidney and lung but low expression in spleen.

Recruitment and dynamics of leukocytes in the formation of arterial intimal thickening--a comparative study with normo- and hypercholesterolemic rabbits.

Leukocyte involvement in intimal thickening was investigated as a function of time and diet. Fibromuscular or foam cell-rich thickings were induced by electrical stimulation (ES) of carotid arteries in rabbits either on a normal or a high (1%) cholesterol diet. Under both dietary conditions granulocytes (predominantly neutrophils), monocytes and lymphocytes migrated through and accumulated beneath a continuous, yet structurally altered endothelium already after 1 day of ES. This preceded the occurrence of smooth muscle cells (SMCs) in the intima. Under normocholesterolemia, leukocyte attachment to the endothelium decreased with continued ES, which coincided with the re-establishment of a normal endothelial cell pattern. Neutrophils ceased to invade the stimulated intima and disappeared from the lesion after 14 days. The proportion of mononuclear leukocytes was also reduced in the thickened intima, finally amounting to 5.5 +/- 5.9% in the 4-week-old fibromuscular lesion where SMCs prevailed. Hypercholesterolemia did not affect neutrophil involvement in response to ES. However, it provoked lipid deposition first in macrophages, then in SMCs and resulted in elevated amounts of mononuclear leukocytes both within the foam cell-rich thickening and in association with the overlying endothelium. These data indicate adaptive behavior of leukocytic infiltration in the development of fibromuscular thickening, and a shift to a chronic inflammatory response under additional hypercholesterolemia.

A combined ELISA-immunoelectron microscopic approach for topological mapping of membrane protein epitopes: application to the nicotinic acetylcholine receptor.

Identification of epitope localization on either side of the lipid membrane by immunoelectron microscopy constitutes an intrinsic powerful method of structure determination for membrane proteins. We have developed a method allowing measurement and observation, under almost identical experimental conditions, of the binding of monoclonal antibodies (MAb) to membrane-bound acetylcholine receptor from Torpedo marmorata electric tissue. This method, based on ELISA and electron microscopy of negatively stained specimens, was developed with MAb of known epitope specificity. With native membrane fragments, we found that MAb bound to extracellular epitopes in a stoichiometric manner, whereas almost no binding was detected for intracellular epitopes. The treatment based on tissue homogenization in the presence of Zn2+ ions and sucrose resulted in the formation of large, stable openings, rendering accessible about 25% of intracellular epitopes. Electron microscopic observations showed a clear distinction between antibody binding to either intracellular or extracellular epitopes, both with native and Zn(2+)-treated membranes. In addition, the binding of one antibody directed against an extracellular epitope was strikingly dependent on the packing density of acetylcholine receptor molecules, thus enabling us to further distinguish between two levels of accessibility for extracellular epitopes. The method presented here is of general application for studies of epitope mapping in membrane proteins.

Myocardial temperature during cardiac operations: influence on right ventricular function.

Maintenance of right heart integrity is frequently neglected during coronary operations. Right ventricular dysfunction sometimes limits the success of the surgical procedure, however. In addition to the use of cardioplegic solutions, myocardial hypothermia during ischemic cardiac arrest seems to be an important factor for guaranteeing right ventricular performance thereafter. This study was designed to measure myocardial temperature in patients with coronary artery disease who have significant stenosis of the right coronary artery in comparison with those who do not have stenosis of the right coronary artery and to evaluate the influence of myocardial temperature on right ventricular hemodynamics after cardiopulmonary bypass. Right ventricular function was assessed by thermodilution technique, which allows measurement of right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume. Right ventricular temperature differed significantly between the two groups, with the lowest value of 15.1 degrees +/- 1.8 degrees C in the group without stenosis of the right coronary artery and a value of 22.2 degrees +/- 2.1 degrees C in the group with stenosis of the right coronary artery. Left ventricular and septal temperatures were without group differences within the investigation period. Right ventricular hemodynamics were impaired only in the group with stenosis of the right coronary artery with a decrease in right ventricular ejection fraction from 44.2% to 34.1% immediately after termination of bypass and an increase in right ventricular end-diastolic volume index (+38%) and right ventricular end-systolic volume index (+70%). Cardiac index decreased only in this group, too (-22.5%). Analysis of covariance revealed a significant correlation only between changes in right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume and the course of right myocardial temperature. It is concluded that right ventricular hypothermia is more difficult to achieve in patients with a diseased right coronary artery. Constant myocardial hypothermia, however, seems to be important in guaranteeing right ventricular function, which easily can be evaluated by the thermodilution technique.

Influence of PEEP ventilation immediately after cardiopulmonary bypass on right ventricular function.

Ventilation with positive end-expiratory pressure (PEEP) is often the appropriate therapy for treating patients with impaired pulmonary function after cardiac surgery procedures. Circulatory depression, however, sometimes limits the level of PEEP. This study was conducted to investigate the effects of PEEP ventilation (+15 cmH2O) immediately after weaning from cardiopulmonary bypass 1) period of PEEP application and 45 min thereafter; 2) period of PEEP application on right ventricular hemodynamics using a new thermodilution technique for measuring right ventricular ejection fraction (RVEF), right ventricular end-diastolic and end-systolic volumes (RVEDV, RVESV). Forty patients undergoing aortocoronary bypass grafting were retrospectively divided into two groups: group 1 (n = 24) in which RVEF was reduced significantly (40----28 percent), and group 2 (n = 16) in which RVEF remained almost unchanged. In patients in group 1, stenosis of the right coronary artery (RCA) was significantly more pronounced in comparison to the others and was detected to be responsible for the different reaction of RVEF (analysis of co-variance). Application of PEEP immediately after weaning from CPB was followed by an increase in RVESV (+4 percent; RVEDV -1 percent) in group 1, whereas patients of group 2 differed significantly (RVESV -14 percent; RVEDV -15 percent). Cardiac index was decreased only in group 1 (-32 percent). During the second period of PEEP application, no further difference could be observed between the groups. We conclude that hemodynamic changes related to PEEP ventilation are minimal in the intact right ventricle. Abnormalities in right ventricular function due to stenosis of the RCA, however, have had marked clinical influence on the circulatory response. Monitoring of right ventricular function seems to be of benefit for cardiac surgery patients in this situation.

Age and cardiac surgery. Influence on extravascular lung water.

This study was designed in order to evaluate the influence of advanced age on extravascular lung water (EVLW) content. Forty patients undergoing aortocoronary bypass grafting were prospectively divided into two groups according to age below 45 years (group 1; n = 20) and above 65 years (group 2; n = 20). The EVLW was measured using the double indicator dilution technique with indocyanine green as the nondiffusible indicator. Starting from similar baseline values before extracorporeal circulation (ECC), EVLW significantly increased after ECC only in the elderly patients (max + 1.51 ml/kg), whereas lung water content in the other group remained almost unchanged. No significant differences in left ventricular filling pressure (PCP) could be observed. Regression analysis revealed a strong positive correlation between age and increase in EVLW after ECC. Simultaneously, PaO2 was decreased (-114 mm Hg) and intrapulmonary shunt fraction (Qs/Qt) was increased only in this group. Within the next five hours after ECC, lung water returned nearly to baseline values and pulmonary function was normalized. It is concluded that increasing age was associated with a transient increase in EVLW after ECC due to a more pronounced fragility of the pulmonary endothelial membrane or/and to depressed left ventricular performance.