Raman and fluorescence micro-spectroscopy applied for the monitoring of sunitinib-loaded porous silicon nanocontainers in cardiac cells.

Nanomaterials are a central pillar in modern medicine. They are thought to optimize drug delivery, enhance therapeutic efficacy, and reduce side-effects. To foster this technology, analytical methods are needed to validate not only the localization and distribution of these nanomaterials, but also their compatibility with cells, drugs, and drug release. In the present work, we assessed nanoparticles based on porous silicon (pSiNPs) loaded with the clinically used tyrosine kinase inhibitor sunitinib for their effectiveness of drug delivery, release, and toxicity in colon cancer cells (HCT 116 cells) and cardiac myoblast cells (H9c2) using Raman micro-spectroscopy, high-resolution fluorescence microscopy, along with biological methods for toxicological effects. We produced pSiNPs with a size of about 100 nm by grinding mesoporous silicon layers. pSiNPs allowed an effective loading of sunitinib due to their high porosity. Photoluminescence properties of the nanoparticles within the visible spectrum allowed the visualization of their uptake in cardiac cells. Raman micro-spectroscopy allowed not only the detection of the uptake and distribution of pSiNPs within the cells via a characteristic silicon Raman band at about 518-520 cm-1, but also the localization of the drug based on its characteristic molecular fingerprints. Cytotoxicity studies by Western blot analyses of apoptotic marker proteins such as caspase-3, and the detection of apoptosis by subG1-positive cell fractions in HCT 116 and MTT analyses in H9c2 cells, suggest a sustained release of sunitinib from pSiNPs and delayed cytotoxicity of sunitinib in HCT 116 cells. The analyses in cardiac cells revealed that pSiNPs are well tolerated and that they may even protect from toxic effects in these cells to some extent. Analyses of the integrity of mitochondrial networks as an early indicator for apoptotic cellular effects seem to validate these observations. Our study suggests pSiNPs-based nanocontainers for efficient and safe drug delivery and Raman micro-spectroscopy as a reliable method for their detection and monitoring. Thus, the herein presented nanocontainers and analytical methods have the potential to allow an efficient advancement of nanoparticles for targeted and sustained intracellular drug release that is of need, e.g., in chronic diseases and for the prevention of cardiac toxicity.

Evaluating the effects of high-oil rapeseed cake or natural additives on methane emissions and performance of dairy cows.

We evaluated the potential of feeding high-oil rapeseed cake or natural additives as rumen modifiers on enteric methane (CH4) emissions, nutrient utilization, performance, and milk fatty acid (FA) profile of dairy cows. Eight Nordic Red dairy cows averaging (mean ± SD) 81 ± 21 d in milk and 41.0 ± 1.9 kg of milk yield at the beginning of the study were randomly assigned to a replicated 4 × 4 Latin square design with 21-d periods. Treatments comprised grass silage-based diets (45:55 forage to concentrate ratio on dry matter basis) including (1) control containing 19.3% rapeseed meal (CON), (2) CON with full replacement of rapeseed meal with rapeseed cake (RSC), (3) supplementation of CON with 50 g/d of yeast hydrolysate product plus coniferous resin acid-based compound (YHR), and (4) supplementation of CON with 20 g/d of combination of garlic-citrus extract and essential oils in a pellet (GCE). Apparent total-tract digestibility was measured using total collection of feces, and CH4 emissions were measured in respiratory chambers on 4 consecutive days. Data collected during d 17 and 21 in each period were used for ANOVA analysis using a mixed model. Treatments did not affect dry matter intake (DMI), whereas feeding RSC increased crude protein and ether extract digestibility compared with the other diets. Emissions of CH4 per day, per kilogram of DMI, and per kilogram of energy-corrected milk, and gross energy intake were lower for RSC compared with other diets. We found no effect of YHR on daily CH4 emissions, whereas CH4 yield (g of CH4/kg of DMI or as percentage of gross energy intake) decreased with GCE compared with CON. Treatments did not influence energy balance. Further, RSC reduced the proportion of N intake excreted in feces, and YHR improved N balance compared with CON diet. Feeding RSC resulted in greatest yields of milk and energy-corrected milk, and feed efficiency. Relative to the CON diet, RSC decreased saturated FA by 10% in milk fat by increasing cis-monounsaturated FA but also increased the proportion of trans FA. Proportion of odd- and branched-chain FA increased with GCE and YHR compared with CON. We conclude that replacing rapeseed meal by rapeseed cake decreased CH4 emissions, whereas YHR or GCE had no effect on CH4 emissions in this study.

Correction: Yes and Lyn play a role in nuclear translocation of the epidermal growth factor receptor.

In Figure 4C, it was identified that the Histone H3 and α-Tubulin purification control blots for YES and LYN overexpressing cells were duplicated. The original Histone H3 control blot was found and confirmed the published results, however, the α-Tubulin control blot was not found. This error was determined to not impact the scientific findings of this figure. The authors regret this error.

Profile of cabanossi made with exotic meats and olive oil.

The effect of olive oil inclusion on the chemical and sensory characteristics in cabanossi made with ostrich and warthog meat was investigated. Ostrich meat from soybean oilcake (SBOC) and cottonseed oilcake dietary inclusion levels (CSOC), and olive oil were included at three levels (0%, 1% and 2%) resulting in six treatments. The fat content in the cabanossi increased with increasing levels of oil inclusion but were all <10%, which allows it to be classified as a low fat meat product. Total monounsaturated fatty acids in the cabanossi increased whilst total saturated fatty acids and total polyunsaturated fatty acids decreased as olive oil increased. The SBOC cabanossi had a lower fat and higher crude protein content. The inclusion of olive oil at 2% resulted in a cabanossi with increased tenderness, juiciness and cured red meat colour, all factors that appeal to the consumer, while the overall flavour descriptors were not adversely affected by the inclusion of olive oil.

Perceived barriers and facilitators in the assessment of occupational diseases.

BACKGROUND: Information is collected worldwide on the diagnosis and assessment of occupational diseases (ODs) by occupational physicians (OPs). However, information on perceived facilitators and barriers to assessment is scarce. AIMS: To evaluate the perceived barriers and facilitators in the assessment of ODs by OPs. METHODS: We conducted a qualitative study, using interviews and focus groups. We held 12 interviews and two focus groups with Dutch OPs, to identify barriers and facilitators in the assessment of ODs. RESULTS: Case definition, exposure assessment, attribution to work, guidelines and decision tools, external expertise, individual motivation and consequences were identified as themes. Barriers and facilitators were mainly reported regarding assessing work attribution, e.g. how to assess multifactorial causes or the need for training, and individual motivation such as the perceived lack of usefulness or the need for monitoring suspected OD cases. Within the theme of consequences, only barriers to the assessment of ODs were reported, including the liability of employers. CONCLUSIONS: Perceived facilitators in the assessment of ODs were practical assessment tools, multifaceted education, ability to assess work exposures and professional independence. Perceived barriers were lack of usefulness, lack of urgency, complexity of assessment and concerns about liability issues.

Improving the assessment of occupational diseases by occupational physicians.

BACKGROUND: The prevention of occupational diseases is limited by a lack of insight into occupational exposure to risk. We developed a six-step approach to improve the diagnosis and reporting of occupational diseases and the selection of subsequent preventive actions by occupational physicians (OPs). AIMS: To evaluate the effect of the six-step approach on the transparency and quality of assessing occupational diseases and the usability of the six-step approach according to OPs and their satisfaction with it. METHODS: A randomized controlled trial. OPs in the control group used the standard information available. OPs in the intervention group used the six-step approach and accompanying educational materials. The actions and decisions of OPs in both groups were analysed using 17 performance indicators. To address the second issue, OPs used the six-step approach over 6 weeks and rated its usability and their satisfaction in relation to several aspects. RESULTS: The average score of the OPs in the intervention group (n = 110) was statistically significantly higher (11/17 performance indicators, 62% of the maximum score) than that of the OPs in the control group (n = 120, 5/17 performance indicators, 30% of the maximum score, P < 0.001). The usability aspects of the six-step approach had mean scores of 7 and 8. Mean satisfaction with the six-step approach was 8. CONCLUSIONS: The six-step approach resulted in better evidence-based and transparent decision-making about occupational diseases by OPs. Usability and satisfaction were rated as satisfactory by the OPs.

[Effectiveness of School-based Interventions to Prevent and/or Reduce Substance Use among Primary and Secondary School Pupils: A Review of Reviews]. / Wie wirksam sind schulbasierte Interventionen zur Prävention und/oder Reduktion von Substanzkonsum bei Schülern/-innen in Grund- und Sekundarschulen? Eine systematische Übersicht vorhandener Reviews.

OBJECTIVE: The aim of this study is to provide a current overview of the effectiveness of school-based interventions on prevention and/or reduction of substance use among children and adolescents aged 5-19 years. METHODS: A systematic literature search was conducted in PubMed, Cochrane Library, Campbell Collaboration, NICE and ERIC. Systematic reviews and meta-analyses published between 2007 and 2013 were included in the analysis. 2 reviewers assessed the quality of the identified review articles and extracted the data. RESULTS: 14 review articles of moderate to good quality fulfilled the a-priori defined inclusion criteria. Capacity-promoting interventions, e. g., those focusing on strengthening self-confidence and peer resistance, show promising evidence of effectiveness. Multi-component and multi-level interventions are more suitable for the prevention of alcohol and cannabis consumption. Findings on the prevention of tobacco consumption are inconsistent. The effectiveness of knowledge-based interventions is limited. The long-term effectiveness of smoke-free competitions cannot be conclusively evaluated as the findings are discrepant. CONCLUSIONS: School-based interventions should include capacity-promoting components and should address further levels beyond the individual, for example, organisational changes of the school setting. Further research is needed, in particular on the effectiveness of multi-component and multi-level interventions for the prevention of tobacco consumption.

[Prevention among migrants: Participation, migrant sensitive strategies and programme characteristics]. / Prävention bei Menschen mit Migrationshintergrund : Teilnahme, migrationssensible Strategien und Angebotscharakteristika.

Health promotion and prevention can contribute to a long, healthy life in populations both with and without migrant background. This paper provides an overview on migrant participation in prevention programmes in Germany. Furthermore, we describe migrant sensitive prevention strategies and characteristics of prevention programmes for migrants in Germany. With regard to participation in prevention programmes, lower vaccination rates are found among children and adolescents who migrated to Germany after birth. Among adults with a migrant background, we found lower participation in general health check-ups, oral health check-ups, cancer screening programs and influenza vaccination. Migrant sensitive prevention strategies address the visual style of the material, a target group specific risk communication, language requirements, a systematic involvement of the target group, and the recognition of deeply rooted sociocultural practices and beliefs. On analyzing a large database on prevention programs in Germany, we found only a few programmes that were exclusively targeted to migrant groups (0.6%). In 16.6% of the programs migrants were addressed as the target group among others. Compared to general population programs, programs for migrants were more often exclusively directed towards girls or women. Moreover, programs for migrants used community-based approaches more often and addressed different age groups. Although information on migrant participation in prevention programs and utilization of migrant sensitive strategies is still incomplete, we can assume that there is a need for diversity-oriented, migrant sensitive prevention.

[The effectiveness of primary prevention interventions promoting physical activity and healthy eating in preschool children: A review of reviews]. / Wie wirksam sind ernährungs- und bewegungsbezogene primärpräventive Interventionen im Setting Kita? : Ein Review von Reviews.

BACKGROUND: During their preschool years children establish nutritional and physical activity (PA) habits that may contribute to the development of overweight and obesity. OBJECTIVE: To examine the evidence for effective interventions promoting healthy eating and PA in childcare settings. METHODS: We searched PubMed, the Cochrane Library, and Campbell Collaboration for systematic reviews published between 2007 and 2014. Ten systematic reviews and three meta-analyses met the inclusion criteria, including a total of 22 intervention studies. Intervention studies were conducted in North America (N = 14), Europe (N = 5), Asia (N = 2), and Australia (N = 1). Half of these addressed ethnic minority groups or socially disadvantaged children. We extracted information about the effects regarding anthropometric measures, eating habits, and physical activity, as well as the characteristics of effective interventions, and summarized them narratively. RESULTS: Evidence for intervention effects on anthropometric measurements was inconclusive. Seven out of nine studies showed beneficial effects on diet-related outcomes. Only isolated effects were reported on improvements in PA. Reviews indicated that interventions which comprised (1) the development of skills and competencies, (2) medium to high parental involvement, and (3) information on behavior-health links for parents were more effective. CONCLUSION: Preschool-based interventions showed some early improvements in eating habits and PA. Evidence is limited by the small number of studies, a lack of methodological quality, and inconsistencies among outcome measures. Evidence regarding anthropometric measurements is still inconclusive.

Yes and Lyn play a role in nuclear translocation of the epidermal growth factor receptor.

The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR antibody that has been approved for use in oncology. Previously we investigated mechanisms of resistance to cetuximab using a model derived from the non-small cell lung cancer line NCI-H226. We demonstrated that cetuximab-resistant clones (Ctx(R)) had increased nuclear localization of the EGFR. This process was mediated by Src family kinases (SFKs), and nuclear EGFR had a role in resistance to cetuximab. To better understand SFK-mediated nuclear translocation of EGFR, we investigated which SFK member(s) controlled this process as well as the EGFR tyrosine residues that are involved. Analyses of mRNA and protein expression indicated upregulation of the SFK members Yes (v-Yes-1 yamaguchi sarcoma viral oncogene) and Lyn (v-yes-1 Yamaguchi sarcoma viral-related oncogene homolog) in all Ctx(R) clones. Further, immunoprecipitation analysis revealed that EGFR interacts with Yes and Lyn in Ctx(R) clones, but not in cetuximab-sensitive (Ctx(S)) parental cells. Using RNAi interference, we found that knockdown of either Yes or Lyn led to loss of EGFR translocation to the nucleus. Conversely, overexpression of Yes or Lyn in low nuclear EGFR-expressing Ctx(S) parental cells led to increased nuclear EGFR. Chromatin immunoprecipitation (ChIP) assays confirmed nuclear EGFR complexes associated with the promoter of the known EGFR target genes B-Myb and iNOS. Further, all Ctx(R) clones exhibited upregulation of B-Myb and iNOS at the mRNA and protein levels. siRNAs directed at Yes or Lyn led to decreased binding of EGFR complexes to the B-Myb and iNOS promoters based on ChIP analyses. SFKs have been shown to phosphorylate EGFR on tyrosines 845 and 1101 (Y845 and Y1101), and mutation of Y1101, but not Y845, impaired nuclear entry of the EGFR. Taken together, our findings demonstrate that Yes and Lyn phosphorylate EGFR at Y1101, which influences EGFR nuclear translocation in this model of cetuximab resistance.

The effects of work-related maternal risk factors on time to pregnancy, preterm birth and birth weight: the Generation R Study.

OBJECTIVE: To investigate the influence of maternal working conditions on fertility and pregnancy outcomes. METHODS: 8880 women were enrolled in a large prospective birth cohort during early (76%), mid (21%) or late pregnancy (3%) (61% participation). Complete questionnaire information was available for 6302 women (71% response). Outcomes were prolonged time to pregnancy (TTP) (> 6 months), preterm birth (< 37 weeks) and decreased birth weight (< 3000 g). Self-reported exposure to chemical agents was based on a limited list of chemicals. Physical load questions concerned manual materials handling, prolonged sitting and long periods of standing. A job-exposure matrix (JEM) linked reported job title to workplace chemical exposure within jobs according to expert judgement. Associations between maternal occupational exposure and fertility and pregnancy outcomes, adjusted for age, education, minority, parity, smoking and alcohol use, were studied using logistic regression analysis. RESULTS: Women in jobs with regular handling of loads ≥ 5 kg had better fertility and pregnancy outcomes. No self-reported exposure to chemicals was associated with any outcomes and self-assessments had very low reliability compared with JEM-based assessments. JEM-based maternal occupational exposure to phthalates was associated with prolonged TTP (OR 2.16, 95% CI 1.02 to 4.57) and exposure to pesticides was associated with decreased birth weight (OR 2.42, 95% CI 1.10 to 5.34). The population attributable fractions were small at 0.7% for phthalates and 0.7% for pesticides. CONCLUSION: This birth cohort study presents evidence of health-based selection into the workforce and adverse effects of maternal occupational exposure to phthalates and pesticides on fertility and pregnancy outcomes.

The effect of dietary fish oil rich in n-3 fatty acids on the organoleptic, fatty acid and physicochemical characteristics of ostrich meat.

The effect of different levels of unrefined fish oil in the diet on ostrich Musculus iliofibularis was evaluated in a completely randomised experimental design, where a supplementary energy rich feed, containing 6.7% fish oil, was fed at four different levels over a 7-month period. An increase in the amount of fish oil consumed was found to have had no significant effect on the sensory characteristics of ostrich meat, although there was a tendency towards an increase in fishiness, for both aroma and flavour. Increased concentrations of fish oil, however, did have a significant effect on the aroma and flavour of the abdominal fat pads. The muscle pH(f) and muscle lightness (L*) revealed a significant reduction, with increased energy intake. However, the increased energy intake had no effect on the chemical composition (moisture, protein, fat, and ash content) of the meat. The fatty acid profile of both adipose tissue and muscle was altered as a result of the consumption of fish oil. The SFA concentration increased, while the PUFA concentration decreased with increasing dietary levels. The MUFA concentration remained constant for all four groups.

Kasai portoenterostomy: differences related to race.

PURPOSE: The aim of this study was to evaluate the Kasai portoenterostomy in African-American and white children with respect to differences in presentation and outcome. METHODS: A retrospective review of all children with biliary atresia who underwent a portoenterostomy at our institution over the last 15 years (n = 63) was performed. Sex, age at the time of Kasai, preoperative laboratory tests, success rates (defined as postoperative total serum bilirubin < or = 2.0 mg/dL), and survival rate were recorded. Differences between African-American (AA; n = 30) and white (W; n = 33) children were analyzed. Long-term follow-up was available on 59 of 63 patients. RESULTS: Sixty-three percent of all patients (40 of 65) were girls, and 48% were AA (30 of 63). A higher percentage of AA children (73%) were girls than were white children (55%), although this difference did not achieve statistical significance. African-Americans underwent portoenterostomy at a later age, had higher alkaline phosphatase levels, and higher AST. These differences were statistically significant. Preoperative ALT, total bilirubin level, and GGTP levels all were greater in African-Americans, although these differences did not achieve statistical significance. There was a trend toward decreased success and survival rate, although these results also were not statistically significant. CONCLUSIONS: African-Americans underwent primary therapeutic intervention for biliary atresia at an older age than white children with a trend toward less favorable results. These differences related to race may be attributed to greater difficulty in diagnosing jaundice or poorer access to health care in this patient population. Increased effort at identifying biliary atresia in AA children may lead to earlier diagnosis and treatment and improved outcomes.

Chick CFC controls Lefty1 expression in the embryonic midline and nodal expression in the lateral plate.

Members of the EGF-CFC family of proteins have recently been implicated as essential cofactors for Nodal signaling. Here we report the isolation of chick CFC and describe its expression pattern, which appears to be similar to Cfc1 in mouse. During early gastrulation, chick CFC was asymmetrically expressed on the left side of Hensen's node as well as in the emerging notochord, prechordal plate, and lateral plate mesoderm. Subsequently, its expression became confined to the heart fields, notochord, and posterior mesoderm. Implantation experiments suggest that chick CFC expression in the lateral plate mesoderm is dependent on BMP signaling, while in the midline its expression depends on an Activin-like signal. The asymmetric expression domain within Hensen's node was not affected by application of FGF8, Noggin, or Shh antibody. Implantation of cells expressing human or mouse CFC2, or chick CFC on the right side of Hensen's node randomized heart looping without affecting expression of genes involved in left-right axis formation, including SnR, Nodal, Car, or Pitx2. Application of antisense oligodeoxynucleotides to the midline of Hamburger-Hamilton stage 4-5 embryos also randomized heart looping, but in contrast to the overexpression experiments, antisense oligodeoxynucleotide treatment resulted in bilateral expression of Nodal, Car, Pitx2, and NKX3.2, whereas Lefty1 expression in the midline was transiently lost. Application of the antisense oligodeoxynucleotides to the lateral plate mesoderm abolished Nodal expression. Thus, chick CFC seems to have a dual function in left-right axis formation by maintaining Nodal expression in the lateral plate mesoderm and controlling expression of Lefty1 expression in the midline territory.

Understanding patterns of failure in breast cancer treatment argues for a more thorough investigation of axillary lymph nodes in node negative patients.

BACKGROUND: An understanding of the patterns of failure after potentially curative treatment of breast cancer patients can lead to the development of improved methods of patient management. METHODS: We compared two groups of patients in whom breast cancer recurred after potentially curative treatment. Patients were assigned to their groups based on the status of their lymph nodes at the time of presentation. RESULTS: In all, 294 recurrences were analyzed to demonstrate that the patterns of failure for the two groups were identical. In the node-positive group, recurrence occurred sooner and their primary tumors were larger. CONCLUSION: The nearly identical patterns of treatment failure in lymph node negative and positive breast cancer patients suggests that metastasis in node negative patients occurs by a similar mechanism. The shorter time to recurrence and larger primary tumor may only reflect a lead time bias, in that node-positive patients have a greater tumor burden in their lymph nodes that facilitates identification by pathologists.

The homeobox gene NKX3.2 is a target of left-right signalling and is expressed on opposite sides in chick and mouse embryos.

Vertebrate internal organs display invariant left-right (L-R) asymmetry. A signalling cascade that sets up L-R asymmetry has recently been identified (reviewed in [1]). On the right side of Hensen's node, activin represses Sonic hedgehog (Shh) expression and induces expression of the genes for the activin receptor (ActRIIa) and fibroblast growth factor-8 (FGF8) [2] [3]. On the left side, Shh induces nodal expression in lateral plate mesoderm (LPM); nodal in turn upregulates left-sided expression of the bicoid-like homeobox gene Pitx2 [4] [5] [6]. Here, we found that the homeobox gene NKX3.2 is asymmetrically expressed in the anterior left LPM and in head mesoderm in the chick embryo. Misexpression of the normally left-sided signals Nodal, Lefty2 and Shh on the right side, or ectopic application of retinoic acid (RA), resulted in upregulation of NKX3.2 contralateral to its normal expression in left LPM. Ectopic application of FGF8 on the left side blocked NKX3.2 expression, whereas the FGF receptor-1 (FGFR-1) antagonist SU5402, implanted on the right side, resulted in bilateral NKX3.2 expression in the LPM, suggesting that FGF8 is an important negative determinant of asymmetric NKX3.2 expression. NKX3.2 expression was also found to be asymmetric in the mouse LPM but, unlike in the chick, it was expressed in the right LPM. In the inversion of embryonic turning (inv) mouse mutant, which has aberrant L-R development, NKX3.2 was expressed predominantly on the left side. Thus, NKX3.2 transcripts accumulate on opposite sides of mouse and chick embryos although, in both the mouse and chick, NKX3.2 expression is controlled by the L-R signalling pathways.

Protective immune responses to the E and NS1 proteins of Murray Valley encephalitis virus in hybrids of flavivirus-resistant mice.

The lack of an effective animal model has been a major obstacle in attempts to define the role of humoral and cellular immune responses in protection against flavivirus infection. We have used F1 hybrid mice (BALB/c x C3H/RV) that are heterozygous for the flavivirus resistance allele F1vr and show reduced virus replication in the brain after intracerebral inoculation. F1 hybrid mice challenged by intracerebral inoculation with Murray Valley encephalitis (MVE) virus developed encephalitis 2-3 days later than a genetically susceptible strain (BALB/c) but showed a similar mortality rate. This delay in the onset of disease provided more opportunity for virus clearance by primed immune responses. Using F1 hybrid mice we were able to demonstrate protective immunity induced by structural and non-structural proteins of MVE virus by immunization with pure NS1 protein or recombinant vaccinia viruses that expressed various regions of the MVE genome. These constructs included VV-STR (C-prM-E-NS1-NS2A), VV-delta C (prM-E-Ns1-NS2A) and VV-NS1 (NS1-NS2A). VV-delta C vaccinated mice were completely protected (100% survival)from challenge with 1000 infectious units of MVE virus, while mice inoculated with VV-STR, VV-NS1 or pure NS1 were partially protected (40%, 47% and 85% respectively). Analysis of prechallenge sera and in vivo depletion studies revealed that the solid protection induced by VV-delta C was mediated by neutralizing antibody to the E protein and did not require a CD8+ T cell response. The partial protection provided by VV-STR, VV-NS1 and pure NS1 occurred after induction of antibody to NS1. However, depletion of CD8+ cells prior to virus challenge ablated the protection provided by VV-NS1 indicating some requirement for class I restricted cytotoxic T cells.

[Cardiac gene expression after brief coronary occlusion]. / Kardiale Genexpression nach kurzen Koronarverschläussen.

In the pig short coronary occlusions induce molecular damage on the protein level in the myocardium, which elicit repair mechanisms by increased transcription and translation, including the activation of potential transcription factors (protooncogenes), genes involved in repair processes (heat shock genes) or calcium-binding genes. Additionally, some growth factors like insulin-like growth factor II show increased transcription in accordance with their function as trophic factors for reversibly injured myocardium. Changes in mRNA levels mostly are due to increased transcription rates and rarely due to prolonged half-life of the mRNA. However, at present our data do not allow us to conclude which genes are causative for myocardial stunning and/or ischemic preconditioning.

Altered expression of titin and contractile proteins in failing human myocardium.

Our own previous ultrastructural studies in human hearts with dilated cardiomyopathy and heart failure showed sarcomeric and cytoskeletal disarrangement. On the basis of these findings we tested the hypothesis that in cardiomyopathic failing hearts not only the sarcomere structure but also the organization and the amount of numerous contractile proteins are disturbed. Titin was included in this study because it is the elastic "third" filament of the sarcomere and also plays an important role as template for myosin and actin filaments in sarcomerogenesis. Human cardiac tissue obtained at the time of transplantation surgery was investigated using immunohistochemistry with monoclonal antibodies against titin, myosin, actin, tropomyosin, and troponin T. Additionally, isolated myocytes from rat or pig heart were used for the standardization of the localization pattern. In normal tissue, myosin and the thin filament complex showed a regular cross striation that was wider in myosin staining than for actin, troponin T, and tropomyosin corresponding with the different width of the A and I bands in the sarcomere. Titin localization in normal human and animal myocardium showed a regular cross striation pattern. In diseased cardiac tissue titin fluorescence intensity was reduced and frequently disorganization or almost complete loss of titin from many myocytes were present. Severe abnormalities of contractile proteins consisting of disarrangement or lack of filaments were also observed. Double staining procedures showed that in the same myocyte defects of the contractile apparatus were accompanied by a simultaneous reduction of titin indicating that the "third" sarcomeric filament system is involved in heart failure. Abnormalities of titin expression may be especially important because titin significantly influences sarcomeric elastic behaviour and is necessary as template for the organization of newly synthesized myosin and actin filaments. The loss of titin may contribute to the altered compliance in failing hearts. It is concluded that disorganization and loss of titin, myosin, and the thin filament complex are severe in the failing human heart because of dilated cardiomyopathy and that these changes may represent several of the most important components of the structural correlate of reduced cardiac function.