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M Grimm

Publications and source records attributed to M Grimm.

At least 19 recordsLinked to original sources
PubMed2006

Charging mechanisms of trapped element-selectively excited nanoparticles exposed to soft x rays.

Charging mechanisms of trapped, element-selectively excited free SiO2 nanoparticles by soft x rays are reported. The absolute charge state of the particles is measured and the electron emission probability is derived. Changes in electron emission processes as a function of photon energy and particle charge are obtained from the charging current. This allows us to distinguish contributions from primary photoelectrons, Auger electrons, and secondary electrons. Processes leading to no change in charge state after absorption of x-ray photons are identified. O 1s-excited SiO2 particles of low charge state indicate that the charging current follows the inner-shell absorption. In contrast, highly charged SiO2 nanoparticles are efficiently charged by resonant Auger processes, whereas direct photoemission and normal Auger processes do not contribute to changes in particle charge. These results are discussed in terms of an electrostatic model.

Journal Article↗
PubMed2006

Recovery from giant cell myocarditis with ECMO support and utilisation of polyclonal antithymocyte globulin: a case report.

Giant cell myocarditis (GCM) is a rare and frequently fatal disorder. Patients suffer of ventricular arrhythmias or congestive heart failure. Here we describe a patient with cardiogenic shock and histological verified GCM. The patient was saved by implantation of extracorporeal membrane oxygeneation (ECMO) device and concomitant application of Rabbit antithymocyte globuline (rATG, Thymoglobulin, Sangstat), cyclosporine, and steroids in the acute event. 12 months after the crisis the patient evidences NYHA class I heart function and only a moderate impairment of heart function (EF 55%). The novel utilisation of ECMO in GCM related cardiogenic shock and application of rATG have prooven life-saving in this patient. Studies utilizing rATG in the treatment of GCM are warrented.

Antilymphocyte Serum↗
PubMed2006

Treatment of an acute type B dissection with an intramural haematoma in the ascending aorta by percutaneous endovascular stent-graft placement.

Acute type B dissections accompanied by an intramural haematoma in the ascending aorta are rare. However, progression of the intramural haematoma in the ascending aorta poses risks for the patients, which are similar to those of type A dissections, including pericardial effusions and consecutive tamponade. To date, no clear treatment guidelines exist for these patients. We report on successful percutaneous endovascular stent-graft treatment of an acute type B dissection accompanied by an intramural haematoma in the ascending aorta as primary and sole form of treatment.

Aged↗
PubMed2006

Superior prevention of acute rejection by tacrolimus vs. cyclosporine in heart transplant recipients--a large European trial.

We compared efficacy and safety of tacrolimus (Tac)-based vs. cyclosporine (CyA) microemulsion-based immunosuppression in combination with azathioprine (Aza) and corticosteroids in heart transplant recipients. During antibody induction, patients were randomized (1:1) to oral treatment with Tac or CyA. Episodes of acute rejection were assessed by protocol biopsies, which underwent local and blinded central evaluation. The full analysis set comprised 157 patients per group. Patient/graft survival was 92.9% for Tac and 89.8% for CyA at 18 months. The primary end point, incidence of first biopsy proven acute rejection (BPAR) of grade >/= 1B at month 6, was 54.0% for Tac vs. 66.4% for CyA (p = 0.029) according to central assessment. Also, incidence of first BPAR of grade >/= 3A at month 6 was significantly lower for Tac vs. CyA; 28.0% vs. 42.0%, respectively (p = 0.013). Significant differences (p < 0.05) emerged between groups for these clinically relevant adverse events: new-onset diabetes mellitus (20.3% vs. 10.5%); post-transplant arterial hypertension (65.6% vs. 77.7%); and dyslipidemia (28.7% vs. 40.1%) for Tac vs. CyA, respectively. Incidence and pattern of infections over 18 months were comparable between groups, as was renal function. Primary use of Tac during antibody induction resulted in superior prevention of acute rejection without an associated increase in infections.

Acute Disease↗
PubMed2005

Mid-term results of conservative, conventional and endovascular treatment for acute traumatic aortic lesions.

BACKGROUND: To analyze our results after conservative, conventional and endovascular treatment for acute traumatic aortic lesions during the last decade. METHODS: From June 1993 to September 2004, a total of 19 patients with traumatic aortic lesions were referred to our department. All patients sustained injuries from blunt deceleration trauma. In hemodynamically stable patients, initial evaluation was by multi-slice CT scan. The diagnosis of traumatic aortic injury was confirmed and an individual treatment strategy was determined. In hemodynamically unstable patients, emergency thoracotomy was performed. RESULTS: An emergency thoracotomy was performed in seven (37%) patients. Mortality in this group was 100%. In the remaining group of 12 (63%) patients without hemodynamic instability at time of admission, in-hospital mortality was 0%. Treatment was surgical in five patients (26%), endovascular in five (26%) and conservative in two patients (11%). Mean follow-up was 63 months (5-108 months). No patient died during follow-up. In patients treated by endovascular stent-graft placement no signs of endoleaks could be detected. CONCLUSIONS: Hemodynamic stability and an individual treatment strategy are prerequisites for survival of acute traumatic aortic lesions. Endovascular stent-graft placement has emerged as an innovative and minimally invasive therapeutic option in this polytraumatic high-risk patient cohort.

Adult↗
PubMed2004

Limb-salvage by femoro-distal bypass and free muscle flap transfer.

OBJECTIVES: To evaluate the feasibility and long-term outcome of distal arterial reconstruction combined with free muscle flap transfer for patients who would otherwise have undergone major amputation. METHODS: Between 1996 and 2001, 27 reconstructions using autologous vein were performed in 25 patients. Seventeen of these patients had diabetes mellitus. Gracilis, rectus abdominis and latissimus dorsi muscles were used as free flaps, covered with split-thickness skin grafts. RESULTS: Eighty-five percent of patients had a patent graft and viable muscle flap after 1-month. Mean follow-up was 51 months (4-72 months). At the time of follow-up 77% of reconstructions were patent and 70% of patients regained full functional capacity of their lower extremities. CONCLUSION: Limb-salvage by distal arterial reconstruction and free muscle flap transfer, is feasible with low mortality and morbidity and provides excellent long-term results with regard to graft patency and functional status.

Arteriovenous Shunt, Surgical↗
PubMed2004

Perfusion temperature during cardiopulmonary bypass does not affect serum S-100beta release.

BACKGROUND: The potentially harmful effects of normothermia on neurological outcome during cardiopulmonary bypass (CPB) are controversial. METHODS: In this study, we compared the early and late release patterns of S-100beta, a marker of cerebral injury, after normothermic and moderately hypothermic CPB. Forty-eight patients undergoing coronary artery bypass grafting were randomly assigned to either the normothermia (37 degrees C) or the hypothermia (32 degrees C) group. Serum S-100beta levels were measured until 24 h after CPB. Neurological examination was performed before and after surgery. RESULTS: With the exception of intraoperative blood glucose levels, there were no differences between groups. This also applied to peak S-100beta values (Gr-N: 3.5 +/- 1.9 microg/l; Gr-H: 3.5 +/- 3.4 microg/l) and values after 24 h (Gr-N: 0.32 +/- 0.16 microg/l; Gr-H: 0.35 +/- 0.28 microg/l). CONCLUSIONS: The similar pattern of S-100beta release without evident neurological complications in the normothermia group does not suggest an increase in cerebral injury during normothermic CPB.

Aged↗
PubMed2003

Rapamycin as rescue therapy in a patient supported by biventricular assist device to heart transplantation with consecutive ongoing rejection.

Rapamycin is a new immunosuppressive agent that has been shown to be effective in acute heart allograft rejection. This case documents a patient suffering from cardiac sarcoidosis who was bridged to transplantation for 90 days with ongoing rejection after allograft implantation. Rejection did not abate despite treatment with antithymocyte globulin (ATG), FK506, a mycophenolate switch and courses of multiple apheresis. Initiation of rapamycin treatment resulted in a rapid resolution of cardiac rejection and reduction of concomitant immunosuppressive agents with few side-effects. Most notably was the reduction of panel reactive antibodies within a few weeks after the rapamycin initiation. This case illustrates that the utilization of rapamycin ceased ongoing rejection in a patient with a clear hyperimmune state despite prior extensive utilization of a variety of immunosuppressive strategies after heart transplantation.

Adult↗
PubMed2003

Predictors of perioperative mortality after coronary artery bypass grafting in the elderly.

BACKGROUND: Coronary artery bypass grafting (CABG) is associated with higher operative risk in the elderly compared to younger patients. The aim of this study was to evaluate risk factors for perioperative mortality after CABG in the elderly. METHODS: We investigated 325 consecutive patients aged 75 or over undergoing isolated CABG at our institution. We analyzed the patients' characteristics and perioperative outcome. Patients were divided into survivors and non-survivors; risk factors and complications were compared. Based on this, we performed a multivariate logistic regression analysis to determine independent risk factors for perioperative mortality. RESULTS: Non-survivors of CABG more often suffered from concomitant extracardiac atherosclerosis (non-survivors, 62.2 %; survivors, 40.6 %; p = 0.013) as well as from renal insufficiency preoperatively (non-survivors, 35.1 %; survivors 8.0 %; p < 0.0001). A trend towards higher incidences of impaired left ventricular function (non-survivors, 37.8 %; survivors, 29.9 %; p = 0.105) and a history of recent myocardial infarction (non-survivors, 29.7 %; survivors, 17.0 %; p = 0.061) were found in non-survivors compared to survivors. Furthermore, non-survivors more often underwent CABG with cardiopulmonary bypass (CPB non-survivors, 96.1 %; survivors 70.6 %; p = 0.0005). Multivariate logistic regression analysis revealed that preoperatively impaired renal function (OR: 2.857, p < 0.0001), use of CPB (OR: 5.952, p = 0.0175), extracardiac atherosclerosis (OR: 1.581, p = 0.0228), and recent myocardial infarction (OR: 1.574, p = 0.0405) were independent risk factors for perioperative mortality. Comparison of patients undergoing CABG with or without CPB reveals that patients operated without CPB had a higher preoperative risk than patients undergoing CABG with CPB. CONCLUSION: These results show that besides impaired renal function, extracardiac atherosclerosis, and history of recent myocardial infarction, the use of CPB is a major risk factor for CABG in the elderly. Perioperative mortality and morbidity can be significantly reduced if CPB is avoided.

Aged↗
PubMed2002

The impact of diabetes mellitus at the time of heart transplantation on long-term survival.

AIMS/HYPOTHESIS: To analyse the impact of diabetes mellitus (DM) at the time of heart transplantation on long-term survival and incidence of transplant coronary artery disease (TxCAD). METHODS: We analysed 773 consecutive adult heart transplant recipients who underwent primary heart transplantation from May 1986 until December 2000. The cohort consisted of 140 patients with diabetes mellitus (with DM, men 82%) and 633 patients without (wo DM, men 84%) diabetes mellitus at the time of transplantation. The patients were documented as to survival and incidence of TxCAD. RESULTS: Patients with diabetes mellitus were older compared to those without diabetes mellitus (with DM 54.9+/-6.8a vs wo DM 49.7+/-10.8a; p=0.0001), they had a higher incidence of ischaemic cardiomyopathy prior to transplantation (with DM 52% vs wo DM 30%; p=0.0001), but reduced long-term survival (10 year survival: with DM 40% vs wo DM 58%; log-rank=0.025). Surprisingly, the incidence of transplant coronary artery disease (TxCAD) was comparable at 10 years (with DM 28% vs wo DM 22%; log-rank=0.625). In multivariate Cox proportional hazard analysis, diabetes mellitus present at the time of heart transplantation (HR 1.594; 95%CI 1.009-2.518; p=0.045), but not age (HR 0.990; 95%CI 0.965-1.014; p=0.404) was an independent predictor affecting long-term survival. CONCLUSION/INTERPRETATION: The presence of diabetes mellitus at the time of heart transplantation adversely affects long-term patient survival, but does not predict the occurrence of transplant coronary artery disease. The definite mechanisms of adverse survival primarily seem to relate to generally impaired global organ function. Despite a less favourable long-term outcome, our data still justify heart transplantation in end-stage heart failure patients with diabetes mellitus.

Adult↗
PubMed2002

[Survival, clinical data and quality of life 10 years after heart transplantation: a prospective study].

AIM: To study prospectively patients after heart transplantation with respect to quality of life, mortality, morbidity, and clinical parameters before and up to 10 years after the operation. METHODS: Sixty patients (47.9 +/- 10.9 years, 57 men, 3 women) were transplanted at the University of Vienna Hospital, Department for Heart and Thorax Surgery and were included in this study. They were assessed when set on the waiting list, then exactly one, 5 and 10 years after the transplantation. The variables evaluated included physical and emotional complaints, well-being, mortality and morbidity. In the sample of patients who survived 10 years (n = 23), morbidity (infections, malignancies, graft arteriosclerosis, and rejection episodes) as well as quality of life were evaluated. RESULTS: Actuarial survival rates were 83.3, 66.7, 48.3% at 1, 5, and 10 years after transplantation, respectively. During the first year, infections were the most important reasons for premature death. As a cause of mortality, malignancies were found between years 1 and 5, and graft arteriosclerosis between years 5 and 10. Physical complaints diminished significantly after the operation, but grew significantly during the period from 5 to 10 years (p < 0.001). However, trembling (p < 0.05) and paraesthesies (p < 0.01) diminished continuously. Emotional complaints such as depression and dysphoria (both p < 0.05) increased until the tenth year after their nadir at year 1. In long-time survivors, 3 malignancies (lung, skin, thyroidea) were diagnosed 6 to 9 years postoperatively. Three patients (13%) had signs of graft arteriosclerosis at year 10; 9 (40%) patients suffered from rejection episodes during the course of 10 years. There were no serious rejection episodes deserving immediate therapy. Quality of life at 10 years is good in these patients. CONCLUSIONS: Heart transplantation is a successful therapy for patients with terminal heart disease. Long-term survivors feel well after 10 years and report a good quality of life.

Actuarial Analysis↗
PubMed2001

Misreading of termination codons in eukaryotes by natural nonsense suppressor tRNAs.

Translational stop codon readthrough provides a regulatory mechanism of gene expression that is extensively utilised by positive-sense ssRNA viruses. The misreading of termination codons is achieved by a variety of naturally occurring suppressor tRNAs whose structure and function is the subject of this survey. All of the nonsense suppressors characterised to date (with the exception of selenocysteine tRNA) are normal cellular tRNAs that are primarily needed for reading their cognate sense codons. As a consequence, recognition of stop codons by natural suppressor tRNAs necessitates unconventional base pairings in anticodon-codon interactions. A number of intrinsic features of the suppressor tRNA contributes to the ability to read non-cognate codons. Apart from anticodon-codon affinity, the extent of base modifications within or 3' of the anticodon may up- or down-regulate the efficiency of suppression. In order to out-compete the polypeptide chain release factor an absolute prerequisite for the action of natural suppressor tRNAs is a suitable nucleotide context, preferentially at the 3' side of the suppressed stop codon. Three major types of viral readthrough sites, based on similar sequences neighbouring the leaky stop codon, can be defined. It is discussed that not only RNA viruses, but also the eukaryotic host organism might gain some profit from cellular suppressor tRNAs.

Animals↗
PubMed2001

Survival benefit of the implantable cardioverter-defibrillator in patients on the waiting list for cardiac transplantation.

BACKGROUND: The implantable cardioverter-defibrillator (ICD) effectively reduces sudden cardiac death in patients with severe LV dysfunction. Effect of ICD therapy on total mortality in patients on the waiting list for cardiac transplantation is still uncertain. METHODS AND RESULTS: We retrospectively analyzed 854 unselected consecutive patients (ICD therapy, n=102; 11.9%) on the waiting list for cardiac transplantation between January 1992 and March 2000. Actuarial 12-month total mortality rate on the waiting list was 24.2%; sudden cardiac death was the predominant mode of death (66.7% of total deaths). Kaplan-Meier analysis revealed improved survival for ICD (total mortality, 13.2%) compared with non-ICD (total mortality, 25.8%) patients (log rank, P=0.03). No event of sudden death occurred in ICD patients, whereas in non-ICD patients, 12-month sudden death rate was 20.1% (P=0.0001). Nonsudden death rates did not differ between ICD and non-ICD patients (P=0.16). A Cox proportional hazards model demonstrated that absence of an ICD was a powerful independent predictor of total mortality (P=0.02; relative risk, 2.22; 95% confidence interval, 1.16 to 4.17) and sudden cardiac death (P<0.0001; infinite relative risk) on the waiting list. CONCLUSIONS: ICD therapy, because it prevents sudden cardiac death, significantly improves survival on the waiting list for cardiac transplantation. The present study supports the use of ICDs as a bridge to transplantation in patients who are at risk of sudden cardiac death. Prospective randomized trials are needed to evaluate the potential benefit of prophylactic ICD therapy as a bridge to transplantation in all patients on cardiac transplant waiting lists.

Comorbidity↗
PubMed2001

The long-term effect of simultaneous heart and kidney transplantation on native renal function.

BACKGROUND: It is unclear whether patients with heart failure and renal insufficiency should receive a simultaneous heart and kidney transplant or whether a single heart transplantation is sufficient to restore native renal function. METHODS: We analyzed the renal plasma flow and glomerular filtration of the native and transplant kidneys in eight patients long term after simultaneous heart and kidney transplantation using a dynamic MAG3 radioisotope scan and serum creatinine determinations. All subjects had been hemodialysis dependent before transplantation. Seven patients suffered from an intrinsic renal disease that were diabetic nephropathy in three cases, small fibrotic kidneys of undetermined origin in two cases, one lupus nephritis, and cyclosporine nephrotoxicity in one patient who had a previous heart transplant. In one patient renal insufficiency was considered to be solely due to renal hypoperfusion because no intrinsic renal disease could be detected. RESULTS: All patients were on cyclosporine-based triple immunosuppression, transplanted for 4 to 10 years, exhibited cardiac ejection fractions of more than 50% and had normal serum creatinine values. Radioisotopic scan showed no function of the native kidneys in all seven patients with intrinsic renal disease but exhibited normal function of the native kidneys as well as the renal transplant in the patient without intrinsic kidney disease before transplantation. CONCLUSIONS: These data suggest that a simultaneous heart and kidney transplantation is necessary in patients with cardiomyopathy and renal insufficiency due to primary kidney disease, but not in those with hemodynamically mediated renal failure, even if an immunosuppressive regimen with calcineurin inhibitors is used.

Aged↗
PubMed2001

Target vessel revascularization without cardiopulmonary bypass in elderly high-risk patients.

BACKGROUND: Coronary artery bypass grafting in patients over 75 years is associated with high operative risk. Target vessel revascularization without cardiopulmonary bypass is a promising option for highly selected, older patients. However, the outcome remains uncertain. METHODS: We investigated 44 patients over 75 years, matched for preoperative risk and left ventricular function, who underwent coronary artery bypass grafting either with or without cardiopulmonary bypass (CPB). We analyzed patients characteristics, Parsonnet score, EuroSCORE, short as well as midterm outcome and quality of life (freedom from recurrence of angina, anti-anginal therapy, sf36 test). RESULTS: Perioperative mortality was higher in the patient group operated with CPB (15.9) as compared to patients operated without CPB (4.5%, p = 0.0226). Patients operated with cardiopulmonary bypass received more grafts (3.1 +/- 0.1) than patients operated without cardiopulmonary bypass (1.6 +/- 0.1, p = 0.0001) and and were more likely to undergo complete revascularization (with CPB 100%, without CPB 63.6%, p = 0.0010). Perioperative complications were more frequent and midterm survival was worse in the patient group operated with CPB (log rank p = 0.0228). Quality of life was comparable in both groups. CONCLUSIONS: The concept of incomplete target vessel revascularization of the culprit lesion seems to be a promising option for selected high-risk patients, predominantly due to lower perioperative mortality.

Aged↗