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Biomedical subjects

K Dreikorn

Publications and source records attributed to K Dreikorn.

At least 19 recordsLinked to original sources
PubMed2005

[Phytotherapy for BPS. Which products can still be prescribed?].

For decades, plant extracts have been amongst to the most popular drugs for lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH)/benign prostatic enlargement (BPE). Only a few of the many published studies meet the criteria of the WHO-BPH consensus conference. The few placebo-controlled, long-term (>/=6 months) studies suggest a positive effect of some extracts (saw palmetto, beta-sitosterol, urtica, rye-grass, saw palmetto/urtica combination) on LUTS; an effect on uroflow, post-void residual volume, prostate volume and PSA was not consistently demonstrable. Randomised trials against an active comparator (alpha1-blocker, 5alpha-reductase inhibitors) are difficult to interpret. Due to the lack of prospective studies, several meta-analyses have been published that can not, however, replace prospective studies. None of the BPH-guidelines currently recommend plant extracts, yet universally conclude that this is an interesting approach. Further prospective studies using WHO standards are required to reliably determine the role of such extracts in the management of elderly men with LUTS due to BPH/BPE.

Clinical Trials as Topic↗
PubMed2005

Risk factors for disease progression in patients with lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH): a systematic analysis of expert opinion.

Disease progression has become an important issue for the management of lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH). Although several risk factors have been identified, no specific patient risk profiles have been established that can be useful in the day-to-day management of LUTS/BPH. In this study, an international panel of urologists developed a risk classification based on the attribution of a risk score to 243 unique patient profiles. From the perspective of clinical decision making, it was concluded that postvoid residual, symptom severity and maximum flow rate are the most relevant determinants of the risk of disease progression.

Disease Progression↗
PubMed2005

Integrating risk profiles for disease progression in the treatment choice for patients with lower urinary tract symptoms/benign prostatic hyperplasia: a combined analysis of external evidence and clinical expertise.

The RAND appropriateness method was used to explore the relevance of risk factors for disease progression in the treatment choice for patients with lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH). A total of, 12 international experts assessed the appropriateness of various treatments for 243 risk profiles. Highest appropriateness rates were found for alpha1-adrenoceptor antagonists (68% of profiles) and combination therapy (46%). A large prostate volume was the dominant argument in favour of 5alpha-reductase inhibitors and combination therapy, but was irrelevant for the choice of surgery. Considerable postvoid residual, severe symptoms and poor maximum flow rate were the most important factors in favour of surgery.

Disease Progression↗
PubMed2002

[Phytotherapy of benign prostatic hyperplasia. Current evidence-based evaluation].

Despite its popularity as a medication in various European countries or as a nutritional supplement in the United States, the role of plant extracts for the treatment of LUTS due to BPH remains controversial. Only a few randomized clinical trials that meet standard criteria of evidence-based medicine but with relatively short follow-up times and some meta-analyses mainly regarding Serenoa repens and Pygeum Africanum as well as more recent studies on pumpkin seeds have shown clinical effects and good tolerability. To better judge the therapeutic potential of these plant extracts, additional randomized placebo-controlled clinical trials with sufficient follow-up are needed.

Evidence-Based Medicine↗
PubMed2000

Phytotherapeutic agents in the treatment of benign prostatic hyperplasia.

The rationale and efficacy of phytotherapeutic agents in the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH) are continuously debated. While plant extracts are prescribed and reimbursable treatment options in Europe, they are officially classified merely as dietary supplements in the United States. The most commonly used preparations originate from the species Serenoa repens, Pygeum africanum, hypoxis rooperi, pinus, picea, urtica dioica, and secale cereale. Combination extracts derived from two or more plants are also used. Various components have been suggested to be active, and different mechanisms of action are being supposed. Open trials and some short-term randomized studies, suggesting safety and efficacy, have been reported. However, if stringent criteria of evidence-based medicine are applied, the data are inconclusive. Therefore, the 4th International Consultation on BPH and the recent German guidelines have not (yet) recommended phytotherapy for the management of symptomatic BPH.

Humans↗
PubMed2000

Gender-specific effects of NAT2 and GSTM1 in bladder cancer.

One approach for risk assessment of cancer is the evaluation of polymorphic enzymes involved in cancer using molecular tools. Phase II enzymes are involved in the detoxification of several drugs, environmental substances and carcinogenic compounds. Here, we analyzed enzymes for their putative relevance in urinary bladder cancer. The hereditable enzyme polymorphism of arylamine N-acetyltransferase 2 (NAT2) and glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) was studied in 157 hospital-based patients and in 223 control subjects. Slow acetylation was not observed to be a significant risk factor of developing bladder cancer (OR: 1.33; 95% CI 0.85-2.09). One genotype responsible for slow acetylation (NAT2*5B/*6A) was observed significantly more frequently in bladder cancer patients compared with control subjects (OR: 1.63; 95% CI 1.03-2.58). Gender-specific effects were observed when patients were divided into subgroups. In male patients, slow acetylators were identified as carrying a significant increased risk of developing bladder cancer, in particular when the genotype NAT2*5B/*6A was combined with the GSTM1 null genotype (OR: 4.39; 95% CI 1.98-9.74). By contrast, the same genotype combination significantly protected female patients from bladder cancer (OR: 0.21; 95% CI 0.06-0.80).

Adult↗
PubMed2000

Susceptibility genes: GSTM1 and GSTM3 as genetic risk factors in bladder cancer.

Glutathione S-transferase (GST, E.C. 2.5.1.18) comprises a family of isoenzymes that play a key role in the detoxification of such exogenous substrates as xenobiotics, environmental substances, and carcinogenic compounds. At least five mammalian GST gene families have been identified to be polymorphic, and mutations or deletions of these genes contribute to the predisposition for several diseases, including cancer. The gene cluster of GSTM1-GSTM5 has been reported to be localized on chromosome 1p and spans a length of nearly 100 kb. One mutation of the GSTM3 gene generates a recognition site for the transcription factor yin yang 1. As a result of this mutation, the expression of GSTM3 can be influenced. The mutated GSTM3 gene has been reported to be involved in increased susceptibility for the development of cancer, but no information is available concerning its role in bladder cancer. We have identified patients with a heterozygous GSTM3 geno- type who carry a significantly increased risk for the development of bladder cancer. Here we report that the mutation of intron 6 of GSTM3 increases the risk for bladder cancer (odds ratio: 2.31; 95% confidence interval [CI], 1.79-2.82). We developed a procedure to identify heterozygous or homozygous carriers of the GSTM1 alleles. Heterozygous carriers of the GSTM1 null genotype have a significantly elevated risk of developing bladder cancer. We calculated an odds ratio of 3.54 (95% CI, 2.99-4.11) for this genotype. These observations lead to the assumption that the lack of detoxification by glutathione conjugation predispose to bladder cancer when at least one of two alleles is affected. Furthermore, individuals presenting the homozygous wild type of GSTM1 and GSTM3 are significantly protected against bladder cancer.

Aged↗
PubMed1999

Efficacy and safety of propiverine in SCI-patients suffering from detrusor hyperreflexia--a double-blind, placebo-controlled clinical trial.

AIMS OF THE STUDY: The aim of this double-blind, randomised, prospective, multicentre trial was to evaluate the efficacy of propiverine in patients suffering from detrusor hyperreflexia caused by spinal cord injury in comparison to placebo. STUDY DESIGN: The treatment period of 14 days comprised visits at baseline (V1) and after 14 days treatment (V2). Fifteen mg propiverine t.i.d. or placebo t.i.d. were administered as medication. The following efficacy parameters were adopted: the urodynamic parameters maximal cystometric bladder capacity, bladder volume on onset of the first as well as duration and amplitude of the maximum detrusor contraction, bladder compliance and residual urine, and subjective assessment of efficacy by physicians. For the evaluation of the safety of propiverine the incidence rate of adverse events by directly questioning as well as laboratory parameters were investigated. For biometrical evaluation t-test for independent groups was applied. RESULTS: One hundred and thirteen patients were investigated. The maximal cystometric bladder capacity increased significantly in the propiverine group, on average by 104 ml (V1: 262+/-132 ml. V2: 366+/-143 ml, P<0.001). The changes in bladder capacity during the first contraction and the maximum detrusor contraction in the verum group were both statistically significant. The bladder compliance documented a more pronounced increase under propiverine in comparison to placebo. Residual urine increased by 37+/-71 ml in the propiverine group, significantly more than in the placebo group (P=0.01). Sixty-three per cent of the patients expressed subjectively an improvement under propiverine in comparison with 23% of the placebo group. Expected anticholinergic adverse events occurred: dryness of the mouth (37% in the verum and 8% in the placebo group), accommodation disorders (28% and 2% respectively). Nausea, constipation, headache, dizziness, tiredness and palpitations were reported in almost comparable incidence rates between 3 and 13% in both treatment groups. Eight drop-outs were registered in the propiverine group (five due to adverse events) and three in the placebo group (one due to adverse events). The laboratory parameters revealed no changes. CONCLUSION: Propiverine proved its efficacy in detrusor hyperreflexia with regard to the urodynamic parameters of the maximal cystometric bladder capacity and detrusor contractility. Anticholinergic adverse events such as dryness of the mouth and accommodation disorders were considered being tolerable. The increase in residual urine reflects the therapeutically desired effect of detrusor relaxation because the majority of patients normally practise intermittent catheterisation for bladder emptying.

Adult↗
PubMed1998

Review of recent placebo-controlled trials utilizing phytotherapeutic agents for treatment of BPH.

BACKGROUND: In order to assess the efficacy of phytotherapeutic agents for the treatment of benign prostatic hyperplasia (BPH), a review of recently published double-blind placebo-controlled trials was undertaken. METHODS: Only those studies reviewed by the Other Medical Therapies Committee of the Fourth International Consultation on BPH were included. RESULTS: These studies suggest a possible benefit for the use of phytotherapeutic preparations in the treatment of BPH. CONCLUSIONS: These studies need to be confirmed in larger long-term placebo-controlled studies in order to ascertain the true efficacy of these agents.

Anti-Bacterial Agents↗
PubMed1998

[Technique of multiple organ procurement. Is involvement of urology indicated?].

Today the organ donor operation in brain dead donors is mostly projected as multiple organ procurement (MOP). Not only the kidneys, but heart and liver or additionally lungs and pancreas are removed in MOP. A good synchronization between the collaborating transplantation groups (thoracic and abdominal surgeon, urologist) is essential to prevent loss of an organ because of technical problems. In Germany urologists perform more than 40% of kidney transplantations. These urologic institutions perform the cadaver kidney retrievals and participate on MOP. If possible, an urologist experienced in renal transplantation should contribute to the care for quality of the kidneys. Since 1987 the transplant center of Bremen obtained 390 donor registrations. 202 organ donor operations have been performed (106 MOP and 96 exclusive kidney retrievals). 398 donor kidneys have been collected and 382 could be transplanted.

Adolescent↗
PubMed1998

Genotyping of the polymorphic N-acetyltransferase (NAT2) and loss of heterozygosity in bladder cancer patients.

Acetylation is one of the major routes in metabolism and detoxification of a large number of drugs, chemicals and carcinogens. Slow acetylators are said to be more susceptible to developing bladder cancer and because of investigations about tumor risk based on phenotyping procedures, it was our aim to study the distribution of allelic constellations of the N-acetyltransferase (NAT2) by genotyping patients with bladder cancer. We analysed NAT2 gene of blood and tumor DNA from 60 patients with primary bladder cancer and DNA of blood samples from 154 healthy individuals. Using ASO-PCR/RFLP techniques we identified 70% of patients with bladder cancer (n = 42) to be slow acetylators while genotyping of controls resulted in 61% with slow acetylators (n = 94). In addition, dividing bladder cancer patients in males and females the genotype NAT2*5B/NAT2*6A occured with much higher frequencies in males (OR = 4, 95%); CI = 1.8-8.9). Furthermore, investigating bladder cancer tissues we could detect loss of heterozygosity (LOH) in slow and rapid acetylator genotypes. In eleven out of 60 tumor samples (18.3%) we observed allelic loss at the NAT2 locus while in control DNA of blood from the same patients both alleles were still detectable.

Acetylation↗