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Biomedical subjects

R Kurek

Publications and source records attributed to R Kurek.

At least 19 recordsLinked to original sources
PubMed2006

The critical path method to analyze and modify OR-workflow: integration of an image documentation system.

Intraoperative image documentation is becoming more and more important for quality management in medicine, in terms of forensic documentation, research and teaching. Up to now, no software-based OR-image-documentation system fits satisfactorily into an OR-workflow. The objective of this study is to transparently show system integration in a clinical workflow for evaluating demands on future system developments. An example of the OR-workflow is presented for the department of obstetrics and gynecology at the University of Tuebingen (Germany). Twelve representative gynecologic laparoscopic surgeries were analyzed by using the critical path method (CPM). CPM network diagrams are shown for an actual laparoscopic workflow and for a workflow including an OR-image-documentation system. With the objective not to increase the total time of actual workflow, the maximum system operation time can be calculated for each period of time. Before surgery the maximum system operation time is x(max) = 7,3 minutes. After surgery it has to be assumed that system operation will increase total workflow time. Using the CPM to analyze requirements for system integration in a medical workflow has not yet been investigated. It is an appropriate method to transparently show integration possibilities and to define workflow-based requirements for the development process of new systems.

Critical Pathways↗
PubMed2002

A multicenter survey of complications associated with 21,676 operative hysteroscopies.

OBJECTIVE: The following study analyses the hysteroscopic experience of multiple gynecologic centers throughout Germany in regard to the incidence of complications, the therapy of these complications and anesthesiological management during 21,676 hysteroscopic procedures. METHODS AND MATERIAL: Under the supervision of the German Society of Gynecology Endoscopy, 92 hysteroscopic centers were evaluated and the following information was collected: hysteroscopic experience in years, number of surgical hysteroscopies per year, total number of operative hysteroscopies, types of hysteroscopic procedures, intra- and post-operative complications. RESULTS AND CONCLUSION: The results of the study show that in most German centers, hysteroscopy is just being established. Nevertheless, the rate of complications such as perforation of the uterus, fluid-overload syndrome, infection and perioperative bleeding is small. This may be due to the high proportion of documented procedures performed by the more experienced centers.

Blood Loss, Surgical↗
PubMed2002

Detection of thyroid peroxidase mRNA in peripheral blood of patients with malignant and benign thyroid diseases.

The aim of this study was to evaluate thyroid peroxidase (TPO) mRNA expression in peripheral blood of patients with benign and malignant thyroid disease. Included were 120 thyroid cancer patients, 85 patients with goitre or Graves' disease (GD) and 54 healthy volunteers. TPO mRNA expression was analysed in peripheral blood by nested RT-PCR. In cancer patients, RT-PCR results were compared with staging, grading and serum thyroglobulin (TG) measurement. TPO transcripts were detected in 7/10 (70%) patients with known metastases of thyroid cancer and in 39 of 110 (36%) patients without metastases (P<0.05), in 15/44 (34%) patients with goitre, in 17/41 (41%) cases with GD and in 4/54 (7.4%) subjects in the control group (P<0.05, controls vs all patients with thyroid disease). Among cancer patients without metastatic disease, RT-PCR results correlated positively with lymph node status (P=0.05), grading (P=0.01) and elevated serum thyroglobulin levels (P=0.03). This is the largest study investigating the use of the TPO-RT-PCR assay. Positivity in TPO-RT-PCR correlates significantly with metastatic disease in cancer patients and with the presence of thyroid disease in general. To date, TPO-RT-PCR cannot substitute for standard techniques in the diagnosis of local recurrence or metastatic spread in thyroid cancer patients. However, as results of TPO-RT-PCR correlate significantly with lymph node status, grading and serum TG measurements in patients with non-metastatic disease, TPO seems to be an interesting molecular marker to look at in follow-up studies.

Adult↗
PubMed2001

Identification and characterization of neutral endopeptidase (EC 3. 4. 24. 11) from human prostasomes--localization in prostatic tissue and cell lines.

BACKGROUND: An antibody directed against a 100 kDa protein was immunoselected from a polyvalent antiserum against human prostasomes. The antibody as well as biochemical characteristics of the respective antigen were used to study the structural relationship of the latter with prostate membrane specific antigen (PMSA), another 100 kDa membrane protein of the prostate. METHODS: The isolated purified 100 kDa protein was characterized by tryptic degradation, aminoacid-sequencing and mass spectroscopy peptide-fingerprinting as well as mono-saccharide analysis and lectin binding and identified as a prostasomal neutral endopeptidase (NEP, EC 3.4.24.11). Immunohistochemistry, immunoelectron microscopy, in situ hybridization, and RT-PCR were performed to analyze the expression and distribution of the protein in normal and malignant human prostatic tissues and cell lines. RESULTS: Prostatic NEP, which has no relationship with PMSA, is a glycosylated, integral membrane protein type II. The prevalent glycosyl residues are NeuNAc, GlcNAc, GalNAc, Gal, Man, Fuc. NEP-mRNA is expressed in human prostatic epithelial and some stromal cells. NEP-immunoreactivity is strong in normal prostatic epithelium and confined to the apical plasma membrane. During apocrine secretion, the enzyme is released from the secretory cells, contributing to the formation of prostasomes. In prostate cancer specimens, immunoreactivity of apical plasma membranes is lost, while generalized cytoplasmic immunoreactivity develops. CONCLUSIONS: Prostatic secretory cells contain a membrane-bound, highly glycosylated neutral endopeptidase which is restricted to the apical plasma membrane. The enzyme is released from the cells in an apocrine fashion and contributes to the formation of prostasomes. In prostate cancer cells a preferential cytoplasmic localization is observed, pointing to alterations in intracellular targeting.

Amino Acid Sequence↗
PubMed2001

Long-term effects on the intelligence of children treated for acute lymphoblastic leukemia.

The purpose of this study was to investigate whether the intelligence quotient (IQ) in children treated for leukemia decreases in the years following whole brain irradiation. Twenty-seven leukemic children were assessed following a mean time lapse between radiotherapy and IQ measurement of 9 years. The IQ test used was the Hamburg Weschsler Intelligence Test for Adults. The IQ results did not differ significantly, p > 0.05, from the IQs of the general population. It was found that age and dose were not predictors of a decrease in IQ. The only predictor was time lapse between irradiation and IQ measurement, which we found to be indicative of an IQ decrease even after 9 years. Time lapse between irradiation is a useful predictor of IQ.

Adult↗
PubMed2000

3D interstitial HDR brachytherapy combined with 3D external beam radiotherapy and androgen deprivation for prostate cancer. Preliminary results.

BACKGROUND: Evaluation of feasibility, tolerance and efficiency for a new 3D interstitial HDR brachytherapy technique combined with 3D external beam radiotherapy and androgen deprivation for prostate cancer. PATIENTS AND METHODS: Between January 1997 and August 1998 we treated 35 patients with stage cT1-3 N0 M0 prostate cancer. Thirty-two patients with a follow-up of 12 to 28 months (median: 18 months) were evaluated. After ultrasound-guided transrectal implantation of 4 non-parallel needles, CT based 3D brachytherapy treatment planning ("Offenbach system") was performed. All patients received 4 fractions brachytherapy using a fractional dose of 5 or 7 Gy. Time between each fraction was 14 days. After brachytherapy 3D external irradiation followed up to 39.6 or 45.0 Gy. All patients received androgen deprivation, starting 2 to 19 months before brachytherapy, ending 3 months after 3D external radiotherapy. RESULTS: Posttreatment PSA levels dropped to < 1.5 ng/ml in 29/32 patients (91%). In 25 patients PSA levels were < 0.5 ng/ml, in 4 patients 0.5 to 1.5 ng/ml. In 2 patients we noted biochemical relapse. Transrectal implantation was very well tolerated. Grade 3 acute urinary toxicity occurred in 1 patient. We noted no Grade 2 or higher acute gastrointestinal toxicity. One patient developed a Grade 3 late urinary toxicity. No patient showed late gastrointestinal side effects. All 140 dose-volume histograms for 3D HDR brachytherapy were analyzed. CONCLUSIONS: The new 3D HDR brachytherapy technique, combined with 3D external irradiation and androgen deprivation, is a feasible, so far well-tolerated and effective treatment in the short-time follow-up of median 18 months.

Adenocarcinoma↗
PubMed2000

[Audiovisual telecommunication by multimedia technology in HNO medicine. ISDN--internet--ATM].

Telemedicine includes all medical activities in diagnosis, therapeutics, or social medicine undertaken by means of an electronic transfer medium, enabling the transmission of visual and acoustic information over long distances to doctors not personally present at the place of the requested consultation. Most experience with telemedicine applications has been gained in the field of diagnosis (teleconsultation, teleradiology, telepathology) and is expanding to quality control and quality assurance. Decisive for each form of application is its availability, practicability, cost, safety, and especially quality of audiovisual transmission. For telesurgical applications, particularly the use of minimally invasive techniques in otorhinolaryngology, head, and neck surgery, the high quality transmission of audiovisual data in real time is necessary. Rapid expansion and further developments in transmission technologies and networks in the last decade have created several technologies with increased quality and costs. In this paper, we tested different transmission media for audiovisual telecommunication--integrated services digital network (ISDN), Internet, and asynchronous transfer mode (ATM)--using real time video transmission of typical operations in otorhinolaryngology. Their applications, costs, and future perspectives are discussed.

Germany↗
PubMed2000

Molecular aspects of intron evolution in dynein encoding mega-genes on the heterochromatic Y chromosome of Drosophila sp.

Fertility genes on the heterochromatic Y chromosome of various Drosophila species are unique for several reasons. Most of them are megabase-sized. Their expression is restricted to premeiotic spermatocytes and often associated with unfolding of huge species-specific lampbrush loops. Molecular analysis of the orthologous dynein genes Dhc-Yh3, DhDhc7(Y) and DeDhc7(Y) on the Y chromosome of the three species D. melanogaster, D. hydei and D. eohydei, respectively, revealed that the megabase gene size as well as the species-specific morphology of the corresponding lampbrush loops kl-5, Threads and diffuse loops result from huge introns and their specific sequence composition, whereas the majority of all 20 introns in each of the three genes is in a size of 45-72 bp. The loop-specifying introns are extreme exceptions due to extended assemblies of degenerated transposable elements and/or large clusters of satellite DNAs. Here we use sequence information from the complete intron sets of three orthologous Y chromosomal dynein genes to deduce a scenario for an evolutionary pathway leading to the megabase-sized genes on the heterochromatic Y chromosome of Drosophila. The obvious bias between very small and species-specific mega introns is explained as the result of an autocatalytic mode of intron growth. An initial coincidental hit by a single transposable element extends the size of a 50 bp intron for about two orders of magnitude and determines it for preferential extension by similar insertion events. This phase of continuous moderate growth is followed by rapid size enlargements by repeating amplifications generating extended clusters of satellite DNA. Size control by recombination, on the other hand, is suppressed in Drosophila males by achiasmatic meiosis.

Animals↗
PubMed2000

The significance of serum levels of insulin-like growth factor-1 in patients with prostate cancer.

OBJECTIVES: To compare the serum levels of insulin-like growth factor-1 (IGF-1) in patients with prostate cancer and in control patients with no malignancy, and to evaluate any possible influence of testicular androgen withdrawal on the level of IGF-1 in patients with prostate cancer. PATIENTS AND METHODS: IGF-1 was measured in serum samples from 238 patients using both a chemiluminescence method and a radio-immunoassay. From a subgroup of 19 patients presenting with newly diagnosed carcinoma of the prostate, IGF-1 and testosterone values were measured before and during the course of testicular androgen withdrawal, achieved by the administration of luteinizing hormone-releasing hormone (LHRH) analogues combined with anti-androgens. RESULTS: There were no significant differences in the mean serum levels of IGF-1 patients with and without prostate cancer (158.6 and 159.1 ng/mL, respectively). There were no significant differences in mean IGF-1 levels before and after antiandrogen therapy; the mean (median, SD, range) levels of testosterone (microg/L) and IGF-1 (ng/mL) before androgen withdrawal were 4.81 (4.84, 1.26, 3.11-6.93) and 157.1 (152.5, 26.7, 122.8-195. 1). After androgen withdrawal the corresponding values were 0.303 (0. 218, 0.24, 0.13-0.81) and 169.7 (31.7, 168.6, 124.9-227.6). A linear regression analysis (P = 0.76) and Spearman rank order correlation test (correlation coefficient -0.0613, P = 0.64) showed no association between levels of testosterone and IGF-1. Freeze and thaw cycles applied to the samples had no effect on the IGF-1 values measured. CONCLUSIONS: There was no significant association between IGF-1 serum levels and prostate cancer. Short-term androgen withdrawal using LHRH analogues combined with anti-androgens had no effect on the levels of IGF-1.

Aged↗
PubMed2000

Molecular detection of thyroglobulin mRNA transcripts in peripheral blood of patients with thyroid disease by RT-PCR.

The sensitive detection of circulating tumour cells in patients with differentiated thyroid cancer may precede the detection of relapse by other diagnostic studies--such as serum thyroglobulin-and thus may have important therapeutic and prognostic implications. We performed reverse transcription-polymerase chain reaction (RT-PCR) on blood samples from patients diagnosed with thyroid disease using two different RT-PCR sensitivities. Additionally, tissue specificity of TG mRNA-expression was determined using RNA extracts from 27 different human tissues. The lower limit of detection was 50-100 TG mRNA producing cells/ml blood using a 'normal' RT-PCR sensitivity and 10-20 cells/ml blood using a 'high' sensitivity. With the normal sensitivity TG mRNA was detected in 9/13 patients with thyroid cancer and metastasis, 63/137 patients with a history of thyroid cancer and no metastasis, 21/85 with non-malignant thyroid disease and 9/50 controls. With the high sensitivity TG mRNA was detected in 11/13 patients with thyroid cancer and metastasis, 111/137 patients with a history of thyroid cancer and no metastasis, 61/85 with non-malignant thyroid disease and 41/50 controls. Interestingly, using the normal RT-PCR sensitivity TG mRNA transcripts are specific for thyroid tissue and detectable in the peripheral blood of controls and patients with thyroid disease, which correlates with a diagnosis of metastasized thyroid cancer. However, with a high RT-PCR sensitivity, TG mRNA expression was found not to be specific for thyroid tissue and was not correlated with a diagnosis of thyroid cancer in patients. As a consequence, to date TG mRNA detected by RT-PCR in the peripheral blood cannot be recommended as a tumour marker superior to TG serum-level.

Case-Control Studies↗
PubMed2000

Mega-introns in the dynein gene DhDhc7(Y) on the heterochromatic Y chromosome give rise to the giant threads loops in primary spermatocytes of Drosophila hydei.

The heterochromatic Y chromosomes of several Drosophila species harbor a small number of male fertility genes (fertility factors) with several unusual features. Expression of their megabase-sized loci is restricted to primary spermatocytes and correlates with the unfolding of species-specific lampbrush loop-like structures resulting from huge transcripts mainly derived from clusters of loop-specific Y chromosomal satellites. Otherwise, there is evidence from genetic mapping and biochemical experiments that at least two of these loops, Threads in Drosophila hydei and kl-5 in D. melanogaster, colocalize with the genes for the axonemal dynein beta heavy chain proteins DhDhc7(Y) and Dhc-Yh3, respectively. Here, we make use of particular Threads mutants with megabase-sized deletions for direct mapping of DhDhc7(Y)-specific exons among the large clusters of satellite DNA within the 5.1-Mb Threads transcription unit. PCR experiments with exon-specific primer pairs, in combination with hybridization experiments with exon- and satellite-specific probes on filters with large PFGE-generated DNA fragments, offer a simple solution for the long-lasting paradox between megabase-sized loops and protein-encoding transcription units; the lampbrush loops Threads and the DhDhc7(Y) gene are one and the same transcription unit, and the giant size of the DhDhc7(Y) gene as well as its appearance as a giant lampbrush loop are merely the result of transcription of huge clusters of satellite DNA within some of its 20 introns.

Animals↗
PubMed2000

Hysteroscopic surgery--complications and their prevention.

During the last few years, diagnostic hysteroscopy has become a standard procedure in the diagnosis of abnormal uterine bleeding, sonographically suspicious endometrial reflex and fertility disorders. At the same time the hysteroscopic treatment of intrauterine pathology is becoming more common. Today, hysteroscopic resection of uterine myomas, dissection of uterine septa, and endometrial ablation are standard procedures. Using monopolar cutting devices and saline-free distension media, hysteroscopic surgery bears specific risks. The knowledge of these risks is important to avoid typical complications of operative hysteroscopy. This article gives an overview about the most common procedures of operative hysteroscopy and the combined risks. Criteria for a safe procedure are defined in order to increase the quality management of operative hysteroscopy.

Endometrium↗
PubMed2000

The 'HysteroTrainer'--an in vitro simulator for hysteroscopy and falloposcopy. Experimental and clinical background and technical realisation including the development of organ modules for electrothermal treatment.

Hysteroscopy and falloposcopy are routine procedures in gynecological endoscopy. Injuries to the cervix or uterine perforations due to blind manipulation or wrong use of instruments are the most common complications associated with these procedures. In vitro simulators have been shown to be valuable tools in the laparoscopic training of physicians. Therefore we developed a simulator for hysteroscopy offering realistic anatomical and physiological training conditions. Additionally, we examined different polymer substances as basic materials for organ modules that allow the realistic application of electric instruments, e.g. resector blades and rollerball.

Equipment and Supplies↗
PubMed1999

Prostate specific membrane antigen (PSM) is expressed in various human tissues: implication for the use of PSM reverse transcription polymerase chain reaction to detect hematogenous prostate cancer spread.

Detection of prostate-specific membrane antigen (PSM)-mRNA expression in blood samples using reverse transcription polymerase chain reaction (RT-PCR) is discussed as a new diagnostic marker of circulating micrometastases in prostate cancer patients. We applied the RT-PCR technique to different human tissues and obtained positive signals for PSM transcripts in human genital and multiple extra-genital tissue sites. The cDNAs were prepared from different human tissues and prostatic cell lines. RT-PCR and nested RT-PCR for PSM was performed with primers derived from the published PSM cDNA. The RT-PCR fragments obtained were cloned and showed 100% sequence homology to PSM. Southern blot hybridization with labeled probes was used to confirm the specificity of the amplicons. In addition to the known PSM expression in the human brain, PSM-mRNA was detected in cDNA isolated from human testis, epididymis and seminal vesicles and in the PC-3 prostatic cancer cell line. Furthermore, we found PSM-mRNA in heart, liver, lung, kidney, spleen, and thyroid gland. The results indicate that PSM expression is not restricted to the prostate gland, but represents a more general component of genital and extra-genital human tissues. This must be considered when RT-PCR and nested RT-PCR screening for PSM expression is performed as a diagnostic measure in blood from prostate cancer patients.

Antigens, Surface↗
PubMed1999

New interstitial HDR brachytherapy technique for prostate cancer: CT based 3D planning after transrectal implantation.

We have developed a new interstitial HDR brachytherapy technique for the treatment of prostate cancer using CT based 3D planning after transrectal implantation of four non-parallel needles. CT based needle reconstruction, target definition, evaluation and documentation, including DVHs and 3D imaging, is a feasible, safe and well tolerated treatment concept.

Adenocarcinoma↗