Biomedical subjects

R Kügler

Publications and source records attributed to R Kügler.

4 recordsLinked to original sources

PubMed2005

Gold-nanoparticle-assisted oligonucleotide immobilisation for improved DNA detection.

Colloidal gold nanoparticles are investigated as a potential scaffold for the assisted immobilisation of probe oligonucleotides on silicon surfaces. A preliminary study is devoted to the examination of the immobilisation of DNA-modified gold nanoparticles as a function of time, concentration, salt and pH. The DNA-modified nanoparticles self-assembled onto solid surfaces in a three-dimensional self-assembled architecture. The functionalised surfaces are evaluated in diagnostic assays, where their potential to improve the efficiency of the hybridisation reaction is tested. The system utilising DNA-modified nanoparticles produced an enhancement in the hybridisation efficiency and the sensitivity limit by a factor 10 to 100 as compared to a conventional DNA immobilisation system on a planar surface.

Adsorption↗

PubMed2005

Evidence of a charge-density threshold for optimum efficiency of biocidal cationic surfaces.

The deposition of organic monolayers containing quaternary ammonium groups has been shown by many authors to confer biocidal properties on a large variety of solid surfaces. In a search for the controlling factors, the authors have grafted quaternized poly(vinylpyridine) chains on glass surfaces by two different methods and varied the charge density within the organic layer between 10(12) and 10(16) positive charges per cm2. The measurements show that this parameter has a large influence on the killing efficiency. Bacterial death occurs in less than 10 min in the quiescent state above a threshold value. The value is smaller for bacteria in the growth state. It also depends on the bacterial type. An electrostatic mechanism based on the exchange of counterions between the functionalized cationic surface and the bacterial membrane is proposed and appears consistent with the results.

Anti-Bacterial Agents↗

PubMed2002

Polyelectrolyte-supported lipid membranes.

In this work, we report the influence of the electrostatic interaction between lipid bilayer membranes and their solid polyelectrolyte multilayer support on the properties of the membrane. All involved sample preparation steps were carried out as convenient adsorption procedures from aqueous solutions. The lipid fluidity within the membrane as well as the surface coverage of the support could be tailored via the electrostatic interaction strength between the lipid bilayer and the supporting polyelectrolyte cushion.

Electrolytes↗

PubMed1997

[The results of primary radiotherapy in vaginal carcinoma].

BACKGROUND: Cancer of the vagina is the least frequent primary malignant tumor of the female genital tract except carcinoma of the fallopian tube. Radiation therapy is the preferred treatment in most cases. PATIENTS AND METHOD: Between 1965 and 1991, 39 patients (median age 66 years) with primary carcinoma of the vagina were treated with radiation therapy at our clinic. The mean observation period was 37 months. Classification according to the FIGO yielded a stage I in 43%, stage II in 24%, stage III in 22% and stage IV in 11%. Histological differentiation resulted in 35 squamous cell carcinomas and 4 adenocarcinomas. In 69%, the tumor was found on the posterior or lateral wall of the vagina, in 43% it arose from the upper third of the vagina. Standard therapy consisted of combined brachy- and teletherapy. Most of the brachytherapy applications were performed with a radium source. RESULTS: Median survival was 37 months, calculated according to the Kaplan-Meier method. The 5-year actuarial survival rate for all stages was 41% (stage 1: 62%, stage II: 44%, stage III: 25%). Sixty-eight percent of all patients achieved a complete remission, 19% a partial response. Significant prognostic factors were stage of disease and histological grading. CONCLUSION: Our results demonstrate the value of radiation therapy for the treatment of primary carcinoma of the vagina. Combined treatment with both external beam radiation and brachytherapy should be preferred.

Adenocarcinoma↗