Biomedical subjects

A Hartmann

Publications and source records attributed to A Hartmann.

At least 19 recordsLinked to original sources

PubMed2007

Genomic aberrations are rare in urothelial neoplasms of patients 19 years or younger.

Urothelial neoplasms in patients 19 years of age or younger are rare, and the data regarding clinical outcome are conflicting. Molecular data are not available. Urothelial tumours from 14 patients aged 4 to 19 years were analysed, including FGFR3 and TP53 mutation screening, comparative genomic hybridization (CGH), UroVysion FISH analysis, polymerase chain reaction for human papillomavirus (HPV), microsatellite analysis using the NIH consensus panel for detection of microsatellite instability (MSI) and six markers for loss of heterozygosity on chromosome arms 9p, 9q, and 17p and immunohistochemistry for TP53, Ki-67, CK20 and the mismatch repair proteins (MRPs) hMSH2, hMLH1, and hMSH6. Based on the 2004 WHO classification, one urothelial papilloma, seven papillary urothelial neoplasms of low malignant potential (PUNLMPs), five low-grade, and one high-grade papillary urothelial carcinoma were included. No multifocal tumours were found and recurrence was seen in only one patient with a urothelial papilloma. All patients were alive with no evidence of disease at a median follow-up of 3.0 years. We found no mutations in FGFR3, deletions of chromosome arms 9p, 9q or 17p, MSI or MRP loss, or HPV positivity in any of the patients. Three cases showed chromosome alterations in CGH analyses, urothelial dedifferentiation with CK20 overexpression, or aneuploidy, and one TP53 mutation with TP53 overexpression was found. Urothelial neoplasms in people younger than 20 years are predominantly low grade and are associated with a favourable clinical outcome. Genetic alterations frequently seen in older adults are extremely rare in young patients. Urothelial neoplasms in children and young adults appear to be biologically distinct and lack genetic instability in most cases.

Adolescent↗

PubMed2006

Routine coronary angiography in diabetic nephropathy patients before transplantation.

We evaluated the incidence of significant coronary artery stenoses (CAS), angina pectoris (AP), revascularization and associated risk factors in 155 consecutive diabetic nephropathy transplant candidates. Kidney and kidney-pancreas transplant candidates with diabetes for more than 10 years and/or retinopathy and/or biopsy verified diabetic nephropathy were included. The inclusion period was 1999-2004. Seventy-two percent of patients were male. Sixty-one percent had type 1 diabetes and 39% had type 2 diabetes and mean age was 46 years (+/-10) and 58 years (+/-11), respectively. History of heart disease was present in 34% of patients, 34% had cerebro-vascular and/or peripheral atherosclerotic disease, and 51% had neither. Fifty-five percent had a smoking history and 46% were on dialysis. Significant CAS was found in 45% of patients, of whom 17% had AP. No patients below 35 years of age had significant CAS (n = 11, p = 0.001). Revascularization was performed in 57% of patients with significant CAS. The only risk factor for significant CAS in multiple logistic regression was age (p = 0.046). Approximately half of the patients had significant CAS, and half of these underwent revascularization. Most patients with CAS did not have symptoms of myocardial ischemia. The data justify screening diabetic nephropathy transplant candidates with coronary angiography before transplantation.

Adult↗

PubMed2006

Inhibition of TEGDMA and HEMA-induced genotoxicity and cell cycle arrest by N-acetylcysteine.

OBJECTIVES: Dental resin monomers like triethylene glycol dimethacrylate (TEGDMA) and 2-hydroxyethyl methacrylate (HEMA) are able to cause an imbalance of the redox state in mammalian cells. The resulting oxidative stress originating from reactive oxygen species (ROS) has been associated with cytotoxicity. We hypothesized that ROS might contribute to the generation of genotoxicity by TEGDMA and HEMA as well. Therefore, we examined the formation of micronuclei in V79 cells by both resin monomers in the presence of the antioxidant N-acetylcysteine (NAC), which scavenges ROS. In addition, we analyzed the effects of TEGDMA and HEMA on the normal cell cycle in the presence of NAC. METHODS: V79 fibroblasts were exposed to increasing concentrations of TEGDMA and HEMA in the presence and absence of NAC for 24h. Genotoxicity was indicated by the formation of micronuclei. The modification of the normal cell cycle was analyzed by flow cytometry (FACS). RESULTS: A dose-related increase in the number of micronuclei in V79 cells-induced by TEGDMA and HEMA indicated genotoxicity of both chemicals. However, the formation of micronuclei was reduced in the presence of 10 mmol/L NAC, indicating its protective role. A cell cycle delay in G2 phase caused by TEGDMA was absent when cells were co-treated with NAC. Similarly, the presence of NAC led to a reversion of the cell cycle delay in HEMA-treated cell cultures. SIGNIFICANCE: Our results suggest that genotoxic effects and the modification of the cell cycle caused by TEGDMA and HEMA are mediated, at least in part, by oxidative stress.

Acetylcysteine↗

PubMed2006

Smoking and cancer-related gene expression in bronchial epithelium and non-small-cell lung cancers.

Tobacco smoking is the leading cause of lung cancer worldwide. Gene expression in surgically resected and microdissected samples of non-small-cell lung cancers (18 squamous cell carcinomas and nine adenocarcinomas), matched normal bronchial epithelium, and peripheral lung tissue from both smokers (n = 22) and non-smokers (n = 5) was studied using the Affymetrix U133A array. A subset of 15 differentially regulated genes was validated by real-time PCR or immunohistochemistry. Hierarchical cluster analysis clearly distinguished between benign and malignant tissue and between squamous cell carcinomas and adenocarcinomas. The bronchial epithelium and adenocarcinomas could be divided into the two subgroups of smokers and non-smokers. By comparison of the gene expression profiles in the bronchial epithelium of non-smokers, smokers, and matched cancer tissues, it was possible to identify a signature of 23 differentially expressed genes, which might reflect early cigarette smoke-induced and cancer-relevant molecular lesions in the central bronchial epithelium of smokers. Ten of these genes are involved in xenobiotic metabolism and redox stress (eg AKR1B10, AKR1C1, and MT1K). One gene is a tumour suppressor gene (HLF); two genes act as oncogenes (FGFR3 and LMO3); two genes are involved in matrix degradation (MMP12 and PTHLH); three genes are related to cell differentiation (SPRR1B, RTN1, and MUC7); and five genes have not been well characterized to date. By comparison of the tobacco-exposed peripheral alveolar lung tissue of smokers with non-smokers and with adenocarcinomas from smokers, it was possible to identify a signature of 27 other differentially expressed genes. These genes are involved in the metabolism of xenobiotics (eg GPX2 and FMO3) and may represent cigarette smoke-induced, cancer-related molecular targets that may be utilized to identify smokers with increased risk for lung cancer.

Adenocarcinoma↗

PubMed2006

[Clinical and immunohistochemical findings of intra- and extraoral angiosarcomas].

PURPOSE: A clinico-pathologic study of typical symptoms of intra- and extraoral angiosarcomas and clinical course under therapy is presented as well as an analysis of the immunohistochemical differential diagnosis of the tumour specific formed spaces. PATIENTS AND METHODS: Four male patients aged 63-78 years suffered from angiosarcomas of the maxillary sinus, the bucca (two patients) and the alveolar ridge of the lower jaw. HISTOPATHOLOGY: For comparative analysis paraffin embedded tissue of the initial biopsies was available. The slides were stained with standardized H&E, PAS and Gömörri. For standardized immunohistochemistry following primary antibodies were applied: monoclonal antibodies to pancytoceratin clones AE1/AE3, alpha-smooth-muscle-actin clone 1A4, CD31 clone JC/70A, factor-VIII-related antigen clone F/86, Fli-1 (polyclonal, Zymed, USA), tenascin-C: BC4 (Prof. L. Zardi), oncofetal glucosylated fibronectin clone FDC6 (ACCR), laminin-5: D4B5. Detection using AP-ChemMate and Autostainer (Dako, Denmark). RESULTS: While the benign appearance of the lesions resulted primarily in wrong diagnoses the histopathologic examination of the biopsies revealed the characteristic pattern of angiosarcomas. Wide surgical excision, radiotherapy and/or antiangiogenic chemotherapy could not prevent tumour progression and death within two and a half years after primary diagnosis. All angiosarcomas reacted partially positive for factor-VIII-related antigen and CD31. The tumour associated structural defect of vascular lamina with partial loss of pericytes/vascular smooth muscle cells was identified immunohistochemically by alpha-smooth-muscle-actin and for the first time by tenascin-C. CONCLUSIONS: (1.) The variable presentation and the benign appearance of oral and perioral angiosarcomas may often delay diagnosis. Oral and perioral angiosarcomas show poor prognosis despite of multimodal therapy. (2.) Cytoceratin and laminin-5-positivity as typical epithelial antigens don't exclude angiosarcoma. Factor-VIII-related antigen, CD31 as well as Fli-1 identify angiosarcoma. (3.) alpha-smooth-muscle-actin and the loss of the tenascin-C-matrix indicate immunohistochemically the characteristic sarcomatous defect of differentiation.

Aged↗

PubMed2006

Minimally invasive kidney transplantation: the first experience.

Minimally invasive procedures in recent years have gained widespread acceptance. Within the field of transplantation, laparoscopic living donor nephrectomy (LLDN), requiring a 6- to 10-cm incision, is now considered the optimal procedure. According to recent MEDLINE searches, no minimally invasive technique has been reported for kidney transplantation. Considering the rapid evolution of minimally invasive surgery during the last decade, there is little reason to believe that kidney transplantation in future will be excluded from this development. A novel minimally invasive technique for kidney transplantation (MIKT) is presented, restricted to a 7- to 9-cm incision and minimal dissection/tissue trauma. The kidney is meticulously prepared on the back table and placed in a fitted lateral, retroperitoneal pouch. All three anastomoses are performed with the kidney in its final "in situ" position, and ureter reimplantation is done by extravesical technique. Twenty-one patients have been transplanted by MIKT and followed in a prospective manner, along with a matched control group subjected to conventional kidney transplantation. Our results indicate that MIKT may be executed safely and quickly. Beneficial effects on postoperative pain/analgesia, recovery, and complications are suggested by this first MIKT experience. The technical solutions of MIKT are per se not unique. However, the incision is minimal and not larger than the one required for LLDN. Minimally invasive surgery seems particularly attractive in the immunosuppressed population, and even more so with the recent introduction of potent antiproliferative drugs.

Adult↗

PubMed2006

[Medical management of patients with atypical degenerative parkinsonian syndromes].

Atypical degenerative parkinsonian syndromes (progressive supranuclar palsy, multiple system atrophy, corticobasal degeneration, Lewy body dementia) are an important differential diagnosis to idiopathic Parkinson's disease. However, because these disorders are characterized by the degeneration of multiple neuronal populations, treatment approaches are much less specific than in Parkinson's disease, where dopamimetic drugs represent the mainstay of therapy. Thus, and because the progression of these disorders is usually more aggressive than Parkinson's disease, many physicians face a form of therapeutic resignation when confronted with patients suffering from atypical degenerative parkinsonian syndromes. However, in the present article, we wish to show that a symptom-by-symptom approach can substantially relieve the patients and their caregivers by providing an overview of pharmacologic and non-pharmacologic treatment options.

Antiparkinson Agents↗

PubMed2006

[Bulimia nervosa].

Bulimia nervosa is characterized by episodes of binge eating and compensatory behaviours (self-induced vomiting, laxative misuse, dietary restriction). It has a complex aetiology and is mostly found in young women. Bulimia leads to substantial physical and psychosocial morbidity. Bulimia nervosa needs specialized psychotherapeutic treatment. In most cases outpatient treatment is sufficient, but comorbidity with other psychiatric disturbances has to be taken into account. Additional psychopharmacological interventions might be helpful. After 5 to 10 years about 50% of the patients show complete remissions, 30% partial remissions and about 20% a chronic course of the illness. General practitioners, dentists and gynaecologists should be informed about typical signs of the disorder that is often hidden by the patients.

Bulimia↗

PubMed2006

[A 29-year-old man with Takayasu's arteritis].

We report on a 29-year-old male patient with collapse and recurrent vertigo. Physical examination showed a bruit of the left common carotid artery on auscultation and a pulselessness of both arms. The diagnosis of Takayasu's arteritis was based on the results of duplex sonography, MRI and angiography (stenosis and occlusion of extracranial arteries). Laboratory results did not reveal any specific changes. Combined treatment with prednisolone and azathioprine was initiated. After 12 days we saw an improvement of duplexsonographical and laboratory findings. Takayasu's disease should be considered as a differential diagnosis in patients with stenosis and occlusions of the aortic arch and its main branches (e.g. pulselessness). MRI is a valuable method in detection of wall abnormalities of the aorta, its branches and other large arteries.

Adult↗

PubMed2006

The impact of early-diagnosed new-onset post-transplantation diabetes mellitus on survival and major cardiac events.

The impact of early-diagnosed new-onset post-transplantation diabetes mellitus (PTDM) on cardiovascular (CV) disease is not well described. The objectives of the present prospective single-center observational study were to assess the long-term effects of early-diagnosed new-onset PTDM on major cardiac events (MCE; cardiac death or nonfatal acute myocardial infarction) and patient survival. Diabetic status and CV risk factors were assessed in 201 consecutive renal allograft recipients 3 months after transplantation (baseline) during a period of 16 months (1995-96). Follow-up data until January 1, 2004 were obtained from the Norwegian Renal Registry. The 8-year (range 7-9 years) cumulative incidence of MCEs was 7% (nine out of 138) in recipients without diabetes, 20% (seven out of 35) in patients with new-onset PTDM and 21% (six out of 28) in patients with diabetes mellitus before transplantation (DM). Proportional hazards regression analyses (forward stepwise regression) revealed that patients with PTDM had an approximately three-fold increased risk of MCEs as compared with nondiabetic patients (hazard ratio (HR)=3.27, 95% confidence interval (CI)=1.22-8.80, P=0.019). A total of 61 patients (30%) died. Eight-year patient survival was 80% in the nondiabetic group, 63% in the PTDM group and 29% in the DM group, respectively. Pretransplant diabetes (HR=5.09, 95% CI=2.60-9.96, P<0.001), age (HR=1.03, 95% CI=1.01-1.05, P=0.016), cytomegalovirus (CMV) infection (HR=2.66, 95% CI=1.27-5.53, P=0.009), and creatinine clearance (HR=0.98, 95% CI=0.96-1.00, P=0.046), but not PTDM (HR=1.20, 95% CI=0.58-2.49, P=0.621), were independent predictors of death in the multiple Cox regression model. Early-diagnosed PTDM is a predictor of MCEs, but not of all-cause mortality, the first 8 years after renal transplantation.

Adult↗

PubMed2006

Inosine monophosphate dehydrogenase activity in renal allograft recipients during mycophenolate treatment.

OBJECTIVE: Mycophenolic acid (MPA) exerts its immunosuppression by inhibiting inosine 5'-monophosphate dehydrogenase (IMPDH), depleting activated lymphocytes of guanine nucleotides and retarding their proliferation. An optimal strategy for monitoring has not been established for mycophenolate mofetil (MMF) in renal transplantation, and clinical investigations of the pharmacokinetic-pharmacodynamic relationship are warranted. MATERIAL AND METHODS: Mycophenolic acid pharmacokinetics and whole blood cell IMPDH activity were investigated in two separate groups of renal allograft recipients. One group was studied within the 12-h dose interval, while the second group was examined by pre-dose samples pre-transplant and then repeatedly during 8 weeks post-transplant. RESULTS: An inverse relationship between plasma MPA and IMPDH activity within the dose interval was demonstrated. Minimum IMPDH activity was a median 8 % of values pre-MMF dose, coinciding with the MPA peak. Six hours post-dose, IMPDH activity had returned to pre-dose values. Patients receiving MMF had a 4.5-fold higher pre-dose enzyme activity than transplanted patients without MMF. During the 8 weeks post-transplant, the median MPA trough concentration was fairly stable. Following an initial decrease during the first 4 days post-transplant, IMPDH activity gradually increased during the 40 days post-transplant, reaching 5-fold the pre-transplant values. CONCLUSIONS: Provided that the changes in IMPDH activity in whole blood cells predict the clinical effect, these pharmacokinetic-pharmacodynamic findings may prove useful in the attempts to identify optimal timing and range for the monitoring of mycophenolate in renal transplantation. The question of whether MPA concentrations or measurements of IMPDH activity per se will be the optimal way of monitoring this immunosuppressant remains open and will only be answered by prospective clinical testing.

Adult↗

PubMed2006

Calcineurin inhibitor-free immunosuppression in renal allograft recipients with thrombotic microangiopathy/hemolytic uremic syndrome.

Thrombotic microangiopathy (TMA) and hemolytic uremic syndrome (HUS) represent serious threats to kidney allograft recipients. During a 4-year period, among 850 kidney transplantations, seven recipients with primary HUS and seven recipients (eight transplants) with previous or de novo TMA/HUS were identified and given calcineurin inhibitor (CNI)-free immunosuppression by sirolimus (SRL), mycophenolate mofetil and steroids. Thirteen out of 15 transplantations were successful in the long term; resulting in a mean creatinine of 101 mumol/L (16.4 months follow-up). In patients maintained on CNI-free regimen, no TMA/HUS recurrences were observed. A high rate of acute rejections (53%) may indicate insufficient immunosuppressive power and/or a causative relationship between TMA/HUS and rejection. Wound-related complications were abundant (60%), and call for surgical/immunosuppressive countermeasures. Our experience supports the idea that CNI's are major offenders in TMA/HUS induction. Total CNI elimination seems essential, as the nephrotoxic combination CNI + SRL may promote TMA. Features of TMA/HUS should be carefully explored in recurrent 'high responders'.

Adult↗

PubMed2006

Multicolor fluorescence in situ hybridization (M-FISH) on cells from urine for the detection of bladder cancer.

Bladder cancer is the fifth most common cancer in adults. Because of the high recurrence rate (up to 70%) new tumor markers for urine are necessary for monitoring patients. In this study, we investigated the value of M-FISH on cells from urine for the detection of bladder cancer. Urine samples from 141 patients suspicious of bladder cancer were analyzed in this study. Cells were isolated from urine before surgical therapy. For FISH analysis, a commercial kit (UroVysion) containing hybridization probes for chromosomes 3, 7, 9p21 and 17, was used. Twenty-five cells were analyzed in each case by two observers. A FISH result was obtained in 121 cases. Overall, sensitivity was 60% and specificity reached 82.6%. Sensitivity and specificity by cytology were 24.1% and 90.5%, respectively. Analyzing results concerning T-category, sensitivity of FISH and cytology was 36.1% and 15% in pTa, 65.2 and 25.7% in pT1, 100% and 66.7% in pT2-3 tumors, respectively. Concerning tumor grade, similar results were obtained: sensitivity was 37% and 14% in G1, 65.4% and 40% in G2, 91.7% and 50% in G3 tumors, for FISH and cytology, respectively. In conclusion, FISH on cells from urine has been shown in all studies to be highly sensitive and specific for detection of bladder cancer. Sensitivity of FISH is higher than conventional cytology and can be used in routine diagnosis additionally to conventional cytology especially in doubtful or negative cases. FISH can detect recurrence earlier than other methods like cytology, cystoscopy or biopsy histological examination.

Cell Nucleus↗

PubMed2005

Different effects of a CD14 gene polymorphism on disease outcome in patients with alcoholic liver disease and chronic hepatitis C infection.

AIM: Clinical and experimental data suggest that gut-derived endotoxins are an important pathogenic factors for progression of chronic liver disease. Recently, a C-T (-159) polymorphism in the promoter region of the CD14 gene was detected and found to confer increased CD14 expression and to be associated with advanced alcoholic liver damage. Here, we investigated this polymorphism in patients with less advanced alcoholic liver disease (ALD) and chronic hepatitis C virus (HCV) infection. METHODS: CD14 genotyping was performed by PCR-RFLP analysis in (a) 121 HCV patients, (b) 62 patients with alcohol-associated cirrhosis (Alc-Ci), (c) 118 individuals with heavy alcohol abuse without evidence of advanced liver damage (Alc-w/o Ci), and (d) 247 healthy controls. Furthermore, serum levels of soluble CD14 (sCD14) and transaminases were determined. RESULTS: The TT genotype was significantly more frequent in Alc-Ci compared to Alc-w/o Ci or controls (40.3% vs 23.7% or 24.0%, respectively). In Alc-w/o Ci, serum levels of transaminases did not differ significantly between patients with different CD14 genotypes. In HCV patients, TT-homozygotes had significantly higher sCD14 levels and sCD14 serum levels were significantly higher in patients with advanced fibrosis or cirrhosis. However, no association was found between CD14 genotypes and histological staging or grading. CONCLUSION: Considering serum transaminases as surrogate markers for alcoholic liver damage, the CD14 polymorphism seems to exhibit different effects during the course of ALD. Differences in genotype distribution between cirrhotic HCV patients and alcoholics and the known functional impact of this polymorphism on CD14 expression levels further indicate differences in the pathophysiological role of CD14 and CD14-mediated lipopolysaccharides signal transduction with regard to the stage as well as the type of the underlying liver disease.

Adult↗

PubMed2005

Cleft lip/palate and CDH1/E-cadherin mutations in families with hereditary diffuse gastric cancer.

We report the association of CDH1/E-cadherin mutations with cleft lip, with or without cleft palate (CLP), in two families with hereditary diffuse gastric cancer (HDGC). In each family, the CDH1 mutation was a splicing mutation generating aberrant transcripts with an in-frame deletion, removing the extracellular cadherin repeat domains involved in cell-cell adhesion. Such transcripts might encode mutant proteins with trans-dominant negative effects. We found that CDH1 is highly expressed at 4 and 5 weeks in the frontonasal prominence, and at 6 weeks in the lateral and medial nasal prominences of human embryos, and is therefore expressed during the critical stages of lip and palate development. These findings suggest that alteration of the E-cadherin pathway can contribute to human clefting.

Adult↗

PubMed2005

[Blood pressure and the brain].

During acute cerebral infarction, autoregulation is abolished. Brain perfusion therefore directly depends on perfusion pressure and cardiac output. For this reason, in the early state of stroke, elevated blood pressure improves cerebral blood flow and only values of 210 mmHg systolic or above should be lowered. With the development of a vasogenic brain edema or a dysfunctional blood-brain barrier (usually on day 2 to 4 after infarction), blood pressure must be normalized in order to avoid hemorrhage and to minimize edema. In the presence of space occupying edema or intracranial hemorrhage, only those antihypertensive substances may be used which do not cause a dilatation of brain vessels. Direct vasodilators and calcium antagonists are not suitable in this situation. Furthermore, antihypertensive medication which causes bradycardia (e.g. beta blockers) should be avoided, because in acute stroke, brain perfusion also depends on the cardiac output. For primary and secondary stroke prevention normalization of blood pressure is essential. Efficacy is basically independent of the kind of antihypertensive medication used. Effective normalization of blood pressure probably helps to prevent vascular dementias of all kinds. Convincing studies however are still lacking for most sorts of antihypertensive medication.

Antihypertensive Agents↗

PubMed2005

Female patient with proximal myotonic myopathy and ventricular tachycardia.

A 68-year-old woman with known proximal myotonic myopathy was transferred to our hospital for further diagnostic and therapeutic evaluation after successful termination of an episode of sustained ventricular tachycardia. In 2001, the myopathy was diagnosed after symptomatic weakness of the hip flexors. A cardiomyopathy with slight reduction of systolic left ventricular function was found in 2002. Coronary angiography excluded relevant coronary artery disease. The electrophysiologic examination could provoke atrial flutter, but neither a ventricular tachycardia nor a delay in the AV conduction was found. ECG and Holter ECG did not reveal any abnormalities. A reduction of the left ventricular systolic function (EF 45%) with normal size of cardiac chambers was demonstrated by echocardiography. It is known that in the patient group with myotonic dystrophies cardiac involvement manifests itself as cardiomyopathy, conduction disturbance or arrhythmia. However, only a small percentage of all patients with myotonic myopathy actually suffer from cardiac involvement. Among the different types of cardiac involvement, conduction disturbances requiring pacemaker implantation are most frequent. Only some patients develop ventricular tachycardias, and even cases of sudden cardiac death have been described. As a result of the case reports in the literature and the findings in our patient an ICD system was implanted on March 4, 2004.

Aged↗

PubMed2005

Mycorrhizosphere responsiveness to atmospheric ozone and inoculation with Phytophthora citricola in a phytotron experiment with spruce/beech mixed cultures.

The aim was to analyze functional changes in the mycorrhizosphere (MR) of juvenile spruce and beech grown in a mixture under ambient and twice ambient ozone and inoculated with the root pathogen Phytophthora citricola. The phytotron experiment was performed over two vegetation periods, adding the pathogen at the end of the first growing season. Root biomass data suggest that the combined treatment affected spruce more than beech and that the negative influence of ozone on stress tolerance against the root pathogen P. citricola was greater for spruce than for beech. In contrast, beech was more affected when the pathogen was the sole stressor. The functional soil parameter chosen for studies of MR soil samples was activity of extracellular enzymes. After the first year of ozone exposure, MR soil samples of both species showed increased activity of almost all measured enzymes (acid phosphatase, chitinase, beta-glucosidase, cellobiohydrolase) in the O3 treatment. Species-specific differences were observed, with a stronger effect of P. citricola on beech MR and a stronger ozone effect on spruce MR. In the second year, the effects of the combined treatment (ozone and P. citricola) were a significant increase in the activity of most enzymes (except cellobiohydrolase) for both tree species. The results indicated that responsiveness of MR soils towards ozone and P. citricola was related to the severity of infection of the plants and the reduction of belowground biomass, suggesting a strong, direct influence of plant stress on MR soil enzyme activity. Additional research is needed using different species and combined stresses to determine the broader ecological relevance of shifts in rhizosphere enzymes.

Atmosphere↗