Universitätspublikationen
Filtern
Erscheinungsjahr
Dokumenttyp
- Dissertation (94) (entfernen)
Sprache
- Englisch (94) (entfernen)
Volltext vorhanden
- ja (94)
Gehört zur Bibliographie
- nein (94)
Schlagworte
- fMRI (2)
- ACKR (1)
- ADHD (1)
- ADHS (1)
- Akaike information criterion (AIC) (1)
- Allgemeinmedizin (1)
- Allosteric inhibition (1)
- Arbeitsgedächtnis (1)
- Audition (1)
- Aurora kinase (1)
Institut
- Medizin (94) (entfernen)
The Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) as well as the T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) are rare types of malignant lymphomas. Both NLPHL and THRLBCL are frequently observed in middle-aged men with THRLBCL presenting frequently with an advanced Ann-Arbor stage with B-symptoms and associated with more aggressive courses.3 However, due to the limited number of tumor cells in the tissue of both NLPHL and THRLBCL, limited numbers of studies have been conducted on these lymphomas and current results are mainly based on general molecular genetic studies.
In order to obtain a better understanding for these disease forms as well as possible changes in their nuclear and cytoplasmatic sizes, the following study relied on the comparison of the different NLPHL forms and THRLBCL in terms of nuclear size and nuclear volume. This was carried out using both 2D and 3D analysis. During the 2D analysis of nuclear size and nuclear volume no significant differences could be presented between those groups. However, the 3D analysis of NLPHL and THRLBCL pointed out a slightly enlarged nuclear volume in THRLBCL. Furthermore, the analysis indicated a significantly increased cytoplasmatic size of THRLBCL compared to NLPHL forms. Nevertheless, differences occurred not only between the tumor cells of both disease forms, but also the T cells presented a larger nuclear volume in THRLBCL. B cells, which were considered as the control group, did not demonstrate any significant differences between the different groups. The presented results suggest an increased activity of T cells in THRLBCL, which is most likely to be interpreted as a response against the surrounding tumor cells and probably limits the proliferation of the tumor cells. Based on these results, the importance of 3D analysis is also evident due to the fact that it is clearly superior to 2D analysis. For a better understanding of both disease forms, it is therefore recommended to use the 3D technique in combination with molecular genetic analysis in future research.
Aortic valve (AV) and root replacement with composite graft and re-implantation of coronary arteries described first by Bentall and de Bono in 1968, is considered as a standard operation for treatment of different pathologies of the AV and aortic root. In centres where aortic valve and root repair techniques and Ross operation are well established, generally severely diseased patients remain indicated for this procedure. The aim of this study was to evaluate the early and long-term outcomes after Bentall-De Bono (BD) procedures in high-risk population with complex pathologies and multiple comorbidities.
Between 2005 and 2018, a total of 273 consecutive patients (median age 66 years; 23 % female) underwent AV and root replacement with composite-graft in so called button technique. We divided our population in the following groups: 1. acute type A aortic dissection group (ATAAD) (n = 48), 2. endocarditis group (n = 99) and 3. all other pathologies group (n = 126). The surgery has been per- formed emergent/urgent in 131 patients (49 %) and in 109 cases (40%) as a reoperation. Concomitant surgery was required in 97 patients (58%) and 167 pa- tients (61%) received a biological composite-graft.
Follow-up was completed in 96% (10 patients lost to follow-up) with a mean of 8.6 years (range 0.1-15.7 years), counting a total of 1450 patient-years. Thirty- day mortality was 17% (46 patients). The overall estimated survival in 5 and 10 years was 64% ± 3%) and 46% ±4 %). Group comparison showed a significant difference in favour of patient from the dissection group (p = 0.008). Implantation of a biological valve graft was associated with lower survival probability (p < 0.001). There was no significant difference in the freedom of reoperation rate between the groups. The same applies for freedom of postoperative endocarditis, thromboembolic events, and aortic prosthesis dysfunction. According to the uni- variate and multivariate logistic regression analysis primarily postoperative neu- rological dysfunction (OR 5.45), hypertension (OR 4.8) peripheral artery disease (OR 4.4), re-exploration for bleeding (OR 3.37) and postoperative renal replace- ment therapy (OR 3.09) were identified as leading predictors of mortality.
In conclusion, the BD operation can be performed with acceptable short- and long-term results in high-risk patients with complex aortic pathologies in a centre with well-established AV repair and Ross operation program.
Recent data indicate that reactive oxygen species (ROS) are produced in the nociceptive system during persistent pain and contribute to pain sensitization. Aim of this study was to investigate potential antinociceptive effects of ROS scavengers in different animal models of pain. Intrathecal injection of ROS scavengers 1-Oxyl-2,2,6,6-tetramethyl -4-hydroxypiperidine (TEMPOL) or Phenyl-N-tert-butylnitrone (PBN) significantly inhibited formalin-induced nociceptive behavior in mice, suggesting that ROS released in the spinal cord are involved in nociceptive processing. Formalin-induced nociceptive behavior was also inhibited by intraperitoneal injection of a combination of vitamin C and vitamin E, but not of vitamin C or vitamin E alone. Moreover, the combination of vitamin C and E dose-dependently attenuated mechanical allodynia in the spared nerve injury (SNI) model of neuropathic pain. The SNI-induced mechanical allodynia was also reduced after intrathecal injection of the combination of vitamin C and E, and western blot analyses revealed that vitamin C and E treatment can ameliorate the activation of p38 MAPK in the spinal cord and in DRGs. These data suggest that a combination of vitamin C and E can inhibit the nociceptive behavior in animal models of pain, and points to a role of the spinal cord as an important area of ROS production during nociceptive processing.
Durch Implementierung eines effizienten Früherkennungsprogramms ist die Inzidenz des Zervixkarzinoms in Industrienationen seit 2005 auf konstant niedrigem Niveau. Ungeachtet dessen ist das Zervixkarzinom mit deutlich höheren Inzidenzraten und weniger als 50% Gesamtüberleben in den nicht industrialisierten Staaten die vierthäufigste Tumorentität der Frau weltweit.
Zur Behandlung des lokal fortgeschrittenen Zervixkarzinoms (FIGO Stadium IIb bis IVa bzw. Ib2/IIa2 mit mehreren histologischen Risikofaktoren) besteht nach aktueller Leitlinie (Stand 2014) und internationalem Konsens Indikation zur platinhaltigen Radiochemotherapie (RCT), subsequent gefolgt von einer (High Dose-Rate) Brachytherapie (HDR-BT). Unter diesen Umständen beträgt die lokale Kontrolle für Patientinnen mit lokal fortgeschrittenem Tumor zwischen 74% und 85%.
Dennoch stagnieren Gesamtüberleben und das spezifische Überleben bezogen auf verschiedene klinische Endpunkte, sodass die Entwicklung neuer Behandlungsstrategien und Therapieoptionen, insbesondere zur Behandlung rezidivierter und metastasierter Erkrankungsstadien, angezeigt ist. Darüber hinaus spielen im Gegensatz zu anderen Tumorentitäten molekulare Marker sowohl als prädiktive als auch als therapeutische Targets bei der Behandlung des Zervixkarzinoms eine bislang untergeordnete Rolle, während molekular-zielgerichtete Therapien in der modernen Krebstherapie einen immer größeren Stellenwert einnehmen.
Ziel der hier vorliegenden Arbeit ist es, neue Biomarker für das Zervixkarzinom und dessen Ansprechen auf simultane Radiochemotherapie und anschließende Brachytherapie zu identifizieren.
Zu diesem Zweck untersuchten wir in einem Patientenkollektiv von 74 Patientinnen mit histologisch gesichertem Zervixkarzinom (FIGO Ib - IVb) prätherapeutisch gewonnenes Biopsiegewebe. Mittels immunhistochemischer Methoden wurde die Expression von Polo-like Kinase 3 (PLK3) und phosphoT273 Caspase-8 erfasst und quantifiziert. Die Ergebnisse wurden anschließend mit klinischen bzw. histo-pathologischen Charakteristika, einschließlich der p16INK4a Expression und den klinischen Endpunkten lokales progressionsfreies- und Fernmetastasen-freies
Überleben bzw. dem tumorspezifischem und dem Gesamtüberleben nach kurativ intendierter Therapie korreliert.
Hierbei konnte zunächst eine signifikante Korrelation zwischen der PLK3 und pT273 Caspase-8 Expression beobachtet werden (p = 0.009). Darüber hinaus war PLK3 signifikant mit dem N-Status (p = 0.046), dem M-Status (0.026) und dem FIGO-Stadium (p = 0.001) assoziiert, wohingegen die pT273 Caspase8-Expression signifikant mit der Tumorgröße (T-Stadium) korreliert war. Bezogen auf univariate Überlebenszeitanalysen war eine erhöhte PLK3-Expression signifikant mit einer geringeren Rate an Fernmetastasen (DMFS p = 0.009) sowie einem signifikant verlängertem tumorspezifischen und Gesamtüberleben assoziiert (CSS p = 0.001, OS p = 0.003). Vergleichbare Ergebnisse konnten auch für die pT273-Caspase 8 Expression mit einer verringerten Metastasierungsrate (p=0.021) und verbessertem tumorspezifischem (p<0,001) sowie Gesamtüberleben (p=<0.001) gezeigt werden. In den multivariaten Analysen verblieb die pT273-Caspase 8-Expression mit einem signifikant verbesserten Gesamtüberleben (p=0.001).
Zusammenfassend belegen diese Daten erstmals eine signifikante Korrelation zwischen einer erhöhten prä-therapeutischen PLK3 und pT273 Caspase 8- Expression und einem zu favorisierenden klinischen Verlauf nach mit Radiochemotherapie behandeltem Zervixkarzinom.
Molecular oxygen (O2) is essential for numerous metabolic processes. Not surprisingly, hypoxia and the resulting adaptations play a pivotal role in pathophysiology, e.g., in cancer or in inflammatory diseases. Of note, myeloid cells are known to accumulate in hypoxic regions such as tumor cores or rheumatoid arthritis joints and may contribute to disease progression. While most studies so far concentrated on transcriptional adaptation by the hypoxia-inducible factors (HIF) 1 and 2 under short term hypoxia, prolonged oxygen deprivation and alternative post-transcriptional regulation are rather poorly investigated.
Consequently, the aim of the study was to generate a comprehensive overview of mRNA de novo synthesis and degradation and its contribution to total mRNA changes in monocytic cells in the course of hypoxia.
To this end, I used thiol-linked alkylation for the metabolic sequencing of RNA (SLAM-Seq) to characterize RNA dynamics under hypoxia. Specifically, I labeled monocytic THP-1 cells under normoxia (N), acute hypoxia (AH; 8 h 1% O2), or chronic hypoxia (CH; 72 h 1% O2) with 4-thiouridine (4sU), which allows for transcriptome-wide identification of de novo synthesized mRNAs and estimation of their half-lives. Total mRNA expression analyses revealed that most changes occurred under CH. Considering that HIF accumulation and resulting transcriptional regulation was shown to decline again under CH, I further analyzed the impact of RNA stability on gene expression. I observed a global reduction in RNA half-lives under hypoxia, indicative for the attenuation of energy-consuming protein synthesis upon oxygen deprivation. Moreover, I observed a subgroup of hypoxic destabilized transcripts with resulting decreased mRNA expression under CH, which consisted of 59 nuclear-encoded mitochondrial mRNAs. This might prevent futile production of new mitochondria under conditions, where mitochondria are even actively degraded to prevent production of detrimental reactive oxygen species.
While stability-regulated transcripts were mainly destabilized under hypoxia, the vast majority of differentially de novo synthesized transcripts were upregulated.
Functional analyses revealed not only hypoxia, but also cholesterol homeostasis and inflammatory response as top enriched terms, corroborating findings on total mRNA level. Focusing on hypoxia-altered cholesterol metabolism, I observed an 9 accumulation of early and a decrease in late cholesterol precursors, which are separated by several oxygen-dependent enzymatic steps. Although total cholesterol levels were only slightly reduced, my data indicate locally lowered endoplasmic reticulum (ER) cholesterol levels under hypoxia, which cause feedback activation of the ER cholesterol-sensing transcription factor sterol regulatory element-binding protein 2 (SREBP2) and induction of cholesterol biosynthesis enzymes. Interestingly, a broad range of interferon-stimulated genes (ISGs), mainly known for their antiviral function, was also induced under hypoxia with similar kinetics as SREBP2 targets, suggesting an immunometabolic crosstalk. While the availability of certain cholesterol biosynthesis intermediates as well as a direct involvement of SREBP2 seemed rather unlikely to cause hypoxic ISG induction, changes in intracellular cholesterol distribution appeared crucial for the hypoxic induction of chemokine-ISGs. Mechanistically, I found that MyD88-dependent toll-like receptor 4 (TLR4) signaling contributes to enhanced hypoxic ISG induction, likely sensitized by changes in cholesterol dynamics. Importantly, hypoxia amplified induction of chemokine-ISGs in monocytes upon treatment with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) spike protein via TLR4 similarly as after addition of infectious virus, which might contribute to systemic inflammation in hypoxemic patients with severe coronavirus disease-2019 (COVID-19).
Taken together, I comprehensively analyzed RNA dynamics in hypoxic monocytes. Specifically, I identified RNA stability as a modulating mechanism to limit production of mitochondria under oxygen-restricted conditions. Moreover, I characterized the immunometabolic crosstalk between disturbed cholesterol homeostasis and spontaneous induction of interferon (IFN)-signaling in hypoxic monocytes, which might contribute to systemic inflammation in severe cases of COVID-19.
Characteristics of critical incident reporting systems in primary care: an international survey
(2022)
Aim: The aim of the study was to support the development of future critical incident reporting systems (CIRS) in primary care by collecting information on existing systems. Our focus was on processes used to report and analyse incidents, as well as strategies used to overcome difficulties.
Methods: Based on literature from throughout the world, we identified existing CIRS in primary care. We developed a questionnaire and sent it to operators of a purposeful sample of 17 CIRS in primary care. We used cross-case analysis to compare the answers and pinpoint important similarities and differences in the CIRS in our sample.
Results: Ten CIRS operators filled out the questionnaire, and 9 systems met the inclusion criteria. The sample of CIRS came from 8 different countries and was rather heterogeneous. The reporting systems invited a broad range of professions to report, with some also including reports by patients. In most cases, reporting was voluntary and conducted via an online reporting form. Reports were analysed locally, centrally, or both. The various CIRS used interesting ideas to deal with barriers. Some, for example, used confidential reporting modes as a compromise between anonymity and the need for follow-up investigations, whereas others used smartphone applications and call centres to speed up the reporting process.
Conclusion: We found multiple CIRS that have operated in primary care for many years, have received a high number of reports and were largely developed in accordance with recommendations found in literature. Although primary care in Germany differs from other countries, these CIRS could serve as an inspiration for CIRS in German primary care.
The impact of the Covid-19 pandemic called for rapid responses in face of unprecedented challenges. In this context, earning more about the causative agent SARS-CoV-2 becomes imperative. Therefore, clinical virus isolates were studied with focus on infectivity, replication kinetic, and caspase activity.
Firstly, clinical specimens collected from patients were tested for infectivity in cell culture. Combined with polymerase chain reaction results, a formula predicting infectivity in cell culture based on abundance of viral RNA was developed. Additionally, analysis of different specimen types, sources, and material, elucidate the question of infectivity. Here, infectivity was demonstrated in specimens derived from different parts of the respiratory tract, including specimens collected from deceased persons. A protocol for virus isolation on human airway epithelium in air-liquid interface culture was established.
Secondly, replication kinetics of 20 clinical isolates were compared, including a subset of seven sequenced isolates. All isolates replicated in the colon epithelial cell culture model. Within the subset, differences between isolates carrying the D614G amino acid exchange and with original spike protein were observed.
Lastly, elevated caspase activity was demonstrated in two cell culture models including human airway epithelium in air-liquid interface culture.
Subsequently, caspase inhibition by small-molecule compound Emricasan and its effects on the cytopathic effect observed in cell culture were studied. Here, increased cell survival in a colon epithelial cell line was shown with unimpaired virus replication. Elevated caspase activity was identified as early marker of infection and validated by testing across 20 clinical virus isolates.
This study offers information on infectivity that can help shape the understanding of transmission risk. As such, parts of the data collected here were used for validation of rapid antigen tests. The insights gained by studying caspase activity contributed in part to the development of a drug screening method by Bojkova et al.,41 thus aiding routine laboratory workflow. It was demonstrated that Emricasan exhibits no antiviral effect, while the finding of increased cell survival in cell culture could give rise to further research on prevention of tissue damage.
Characterization of SPRTN, the first mammalian metalloprotease that repairs DNA-protein-crosslinks
(2019)
DNA is constantly exposed to various endogenous and exogenous sources causing different kinds of DNA damage. To overcome this threat, cells have evolved various repair mechanisms. Impairments of these repair mechanisms result in diverse diseases. Ruijs-Aalfs syndrome is a monogenic disease characterized by accelerated ageing and carcinogenesis, typical features of impaired DNA repair and was shown to be caused by germline mutations of SPRTN, a newly identified and only partially understood protein. A role of SPRTN in DNA damage response was previously shown and an involvement in translesion synthesis (TLS) proposed. However, later discoveries revealed an essential function of SPRTN, being indispensible for embryonic development of vertebrates and cellular survival, whereby this function is independent of SPRTN’s proposed function in TLS. The essential function of SPRTN was proposed to be contained in its protease domain but remained unclear.
In this study we identify SPRTN as the first mammalian metalloprotease that repairs DNA-protein-crosslinks (DPCs). DPCs represent a specific type of DNA-lesions with bulky protein adducts covalently linked to DNA thereby being highly toxic as they potentially stall replication forks and lead to double strand breaks and genomic instability. DPC-repair remains only partially understood despite their frequent appearance and toxicity. With this study we discover and characterize a new mechanism of DPC-repair in mammalian cells - a proteolytic cleavage of the protein adduct by the metalloprotease SPRTN. Accordingly, a proteolytic activity of SPRTN is demonstrated and s SPRTN-recruitment to DNA upon DPC-induction displayed. Furthermore, SPRTN exhibits degradation of different proteins covalently bound to DNA in form of DPCs, but not of unbound fractions of the same protein substrates. Consequently, mutations of SPRTN’s proteolytic core as well as a mislocalization or depletion of SPRTN result in impaired DPC-repair. The importance of SPRTN-mediated DPC-removal is confirmed by a severely compromised response to DPC-inducing agents for cells with impaired SPRTN function. Additionally to the discovery of SPRTN’s essential function this study further provides an explanation of the molecular mechanism underlying Ruijs-Aalfs syndrome (RJALS), the segmental progeroid syndrome resulting from SPRTN mutation. The effects of the identified clinical mutations on the DPC-repair function of SPRTN are explained and a DPC-accumulation in cells carrying clinical SPRTN-mutation displayed. The obtained data provides sufficient evidence that an impaired DPC-repair is the pathophysiologic cause of RJALS-syndrome, confirming the importance of SPRTN’s newly identified function. In conclusion, SPRTN is the first identified mammalian metalloprotease with a DPC-repairing function and the impairment of SPRTN-mediated DPC-removal is the underlying mechanism of RJALS syndrome.
One of the earliest and most striking observations made about HIV is the extensive genetic variation that the virus has within individual hosts, particularly in the hypervariable regions of the env gene which is divided into 5 variable regions (V1-V5) and 5 more constant (C1-C5) regions. HIV evolves at any time over the course of an individual’s infection and infected individuals harbours a population of genetically related but non-identical viruses that are under constant change and ready to adapt to changes in their environment. These genetically heterogeneous populations of closely related genomes are called quasispecies [65]. Tuberculosis or tubercle forming disease is an acute and/or chronic bacterial infection that primarily attacks the lungs, but which may also affect the kidneys, bones, lymph nodes, and brain. The disease is caused by Mycobacterium tuberculosis (MTB), a slow growing rod-shaped, acid fast bacterium. It is transmitted from person to person through inhalation of bacteria-carrying air droplets. Worldwide, one person out of three is infected with Mycobacterium tuberculosis – two billion people in total. TB currently holds the seventh place in the global ranking of causes of death [73]. In 2008, there were an estimated 9.4 (range, 8.9–9.9 million) million incident cases (equivalent to 139 cases per 100 000 population) of TB globally [75]. A complex biological interplay occurs between M. tuberculosis and HIV in coinfected host that results in the worsening of both pathologies. HIV promotes progression of M. tuberculosis either by endogenous reactivation or exogenous reinfection [77, 78] and, the course of HIV-1 infection is accelerated subsequent to the development of TB [80]. Active TB is associated with an increase in intra-patient HIV-1 diversity both systemically and at the infected lung sites [64,122]. The sustainability or reversal of the HIV-1 quasispecies heterogeneity after TB treatment is not known. Tetanus toxoid vaccinated HIV-1 infected patients developed a transient increase in HIV-1 heterogeneity which was reversed after few weeks [121]. Emergence of a heterogeneous HIV-1 population within a patient may be one of the mechanisms to escape strong immune or drug pressure [65,128]. The existence of better fitting and/or immune escape HIV-variants can lead to an increase in HIV-1 replication [129,130]. It might be that TB favourably selected HIV-1 variants which are sources for consistent HIV-1 replication. Understanding the mechanisms underlying the impacts of TB on HIV-1 is essential for the development of effective measures to reduce TB related morbidity and mortality in HIV-1 infected individuals. In the present study we studied whether the increase in HIV-1 quasispecies diversity during active TB is reversed or preserved throughout the course of antituberculous chemotherapy. For this purpose Two time point HIV-1 quasispecies were evaluated by comparing HIV-1 infected patients with active tuberculosis (HIV-1/TB) and HIV-1 infected patients without tuberculosis (HIV-1/non TB). Plasma samples were obtained from the Frankfurt HIV cohort and HIV-1 RNA was isolated. C2V5 env was amplified by PCR and molecular cloning was performed. Eight to twenty five clones were sequenced from each patient. Various phylogenetic analyses were performed including tree inferences, intra-patient viral diversity and divergence, selective pressure, co-receptor usage prediction and two time point identity of quasispecies comparison using Mantel’s test. We found out from this study that: 1) Active TB sustains HIV-1 quasispecies diversity for longer period 2. Active TB increases the rate of HIV-1 divergence 3) TB might slow down evolution of X4 variants And we concluded that active TB has an impact on HIV-1 viral diversity and divergence over time. The influence of active TB on longitudinal evolution of HIV- 1 may be predominant for R5 viruses. The use of CCR5-coreceptor inhibitors for HIV-1/TB patients as therapeutic approach needs further investigation.
Clinical application of transcranial Doppler for detection of cerebral emboli during cardiac surgery
(2010)
Objective: Neurologic injury is one of the most damaging complications for cardiac surgery. How to decrease neurologic impairment by improving perioperative monitoring remains a challenge for both cardiac surgeons and anesthetists. For this reason, transcranial doppler (TCD) has been widely used in cerebral monitoring during cardiac surgery. In this study, two experiments of clinical application of TCD for detection of cerebral emboli during cardiac surgery were to be done. One was “Solid and gaseous cerebral emboli during valvular surgery are significantly reduced with axillary artery cannulation”. The other was “Do intraoperative cerebral embolic signals differ between valvular surgery (VS) and CABG”. Methods: In experiment one, 20 valve and combined procedures with aortic cannulation (AoC group) were compared to 18 procedures with axillary cannulation (AxC group) in a prospective non-randomized study. In experiment two, 18 VS patients and 18 CABG patients were matched by extracorporeal circulation (ECC) time retrospectively. Intraoperative monitoring of both middle cerebral arteries was performed with TCD discriminating between solid and gaseous embolic signals (ES). Results: In experiment one, the AxC group had less solid ES than the AoC group (38±22 vs 55±25, P<0.05), but no significant difference was found in gaseous (501±271 vs 538±333, P>0.05) and total (539 ± 279 vs 593 ± 350, P>0.05) ES. The AxC group had less solid ES during arterial cannulation (2.1±1.5 vs 6.6±3.6, P<0.05) and during aortic cross-clamp time (4.4 ±3.1 vs 10.2 ± 5.1, P<0.05) than the AoC group. During ECC, gaseous ES was not significantly different between groups (398±210 vs 448±291, P>0.05). However, AxC showed less gaseous ES (85±68 vs 187±148, P<0.05) and less gaseous ES per minute (1.8±1.5 vs 4.5±3.2, P<0.05) during weaning off extracorporeal circulation than the AoC group. No significant difference in gaseous ES (313±163 vs 261±189, P>0.05) and gaseous ES per minute (3.1±2.2 vs 2.8±2.2, P>0.05) was found between groups from bypass start to aortic declamping. No neurologic complications occurred. In experiment two, no significant difference was found in solid (38±20 vs 40±26, P>0.05) or gaseous (457±263 vs 412±157, P>0.05) ES between the VS and CABG group during the whole recording time. During ECC, solid ES (20±10 vs 24±19, P>0.05) and gaseous ES (368±230 vs 317±157, P>0.05) were comparable between groups. Specifically, during weaning off ECC, the VS group had more gaseous ES/min (5.6±3.6 vs 3.1±1.2, P<0.05) than the CABG group. But this difference in gaseous ES/min was not significant during the period from bypass start to aortic declamping (2.5±1.8 vs 3.0±1.8, P>0.05). Conclusion: Cerebral embolization does occur during cardiac surgery. Through these two experiments, we demonstrated the feasibility and importance of clinical application of transcranial doppler for detection of cerebral emboli during cardiac surgery. Due to the diversity in clinical application of TCD, it is impossible to compare the number of ES between different research centers. More unified standards should be drawn in order to make wider clinical application possible. Up till now, no robust evidence shows the correlation between intraoperative ES and postoperative neurological impairment. The research on intraoperative ES and postoperative neurological impairment should rely on a complete concept.