Biomedical subjects

Karl Illmensee

Publications and source records attributed to Karl Illmensee.

8 recordsLinked to original sources

PubMed2006

Tissue perfusion-controlled guided biopsies are essential for the outcome of testicular sperm extraction.

OBJECTIVE: To determine if there are areas of major and minor perfusion in a single testicle, and if the quality and quantity of sperm are correlated with the level of perfusion, we collected testicular tissue from areas with different levels of perfusion. DESIGN: Controlled clinical study. SETTING: Consecutive patients with azoospermia. PATIENT(S): Patients with azoospermia undergoing testicular sperm extraction (TESE) biopsy for the retrieval of sperm to be used in an assisted reproduction program. INTERVENTION(S): Perfusion mapping was performed with the use of color Doppler ultrasound. Areas with different levels of perfusion were marked with needles. After incision with radiofrequency cutting, the exposed tissue was examined with a laser Doppler flowmeter, and biopsies were taken for TESE and histology. Sperm were analyzed using World Health Organization criteria, and prepared for intracytoplasmic sperm injection (ICSI). MAIN OUTCOME MEASURE(S): Correlation of sperm quality and quantity in testicular-tissue biopsies, with tissue-perfusion units (TPU) measured by laser Doppler flowmeter. RESULT(S): From 40 biopsies taken from 20 testicles of 12 patients, tissue was analyzed for sperm quality and quantity. Sperm quality was highest in areas of high tissue perfusion. In areas of 70 TPU, 72.3% progressive sperm were detected, whereas in areas of 10 TPU, only 13.3% progressive sperm and elevated numbers of precursor cells could be observed. The number of motile sperm isolated from tissue samples correlated well with the intensity of tissue perfusion. CONCLUSION(S): We have shown for the first time that in patients suffering from azoospermia, sperm quality and quantity depend on tissue perfusion within the testicle.

Adult↗

PubMed2006

In vitro blastocyst development from serially split mouse embryos and future implications for human assisted reproductive technologies.

OBJECTIVE: To assess the efficacy of serial splitting of mouse embryos with respect to blastocyst development. DESIGN: Prospective study. SETTING: Commercial research facility. ANIMAL(S): Commercially available mouse embryos from B6C3F-1 x B6D2F-1. INTERVENTION(S): One, two, and three blastomeres were biopsied from two-, four-, and six-cell embryos, respectively, and were inserted into empty zona pellucida recipients (first split). These embryos were cultured to reach their original cell number status and then were split again (second split). Once these embryos regained their original cell status, they were split yet again (third split). MAIN OUTCOME MEASURE(S): Blastocyst development of embryos split serially at the two-, four-, and six-cell stages. RESULT(S): The blastocyst development rate for two-, four-, and six-cell embryos subjected to a first split was 74.3%, 75.0%, and 66.6%, respectively, as compared with 71.8%, 62.6%, and 48.4% (second split) and 48.4%, 38.1%, and 10.6% (third split). CONCLUSION(S): First and second splitting of cleavage-stage embryos has yielded high efficiency rates for blastocyst development when compared with the third splitting, which did not provide any beneficial advantage for further embryo splitting and multiplication. This is the first study reporting on three serial embryo splittings in a mammalian species. Embryo splitting may have significant impact and applications in human assisted reproductive technology.

Animals↗

PubMed2006

Evaluation of the embryonic preimplantation potential of human adult somatic cells via an embryo interspecies bioassay using bovine oocytes.

OBJECTIVE: To examine the embryonic preimplantation potential of human adult somatic cells by creating interspecies embryos via somatic cell nuclear transfer (SCNT) using bovine oocytes. DESIGN: Prospective study. SETTING: Research facility of Reprogen. PATIENT(S): Infertile couples. INTERVENTION(S): Enucleated bovine oocytes were fused via SCNT with either human granulosa (HG) or fibroblast (HF) cells and cultured in vitro. Polymerase chain reaction (PCR) and DNA analysis were performed on the interspecies embryos. Parthenogenetically activated embryos served as controls. MAIN OUTCOME MEASURE(S): Embryonic preimplantation development after interspecies SCNT. RESULT(S): From enucleated bovine oocytes fused with HG cells (n = 48) and HF cells (n = 75), 15 HG- and 22 HF-derived embryos developed, some of which progressed to blastocysts (31.3% vs. 29.3%, respectively). The PCR and DNA analysis showed that the interspecies embryos contained human genomic DNA specific for the individual DNA profile of the HG or HF donor cells used for SCNT. In addition, both bovine- and human-specific mitochondrial DNA was detectable in the interspecies embryos up to the blastocyst stage. Parthenogenetic development was 46.8% and 64.9% for the HG and HF series, respectively. The SCNT efficiency index, defined as the ratio of SCNT and parthenogenetic success rate, was 66.8% for HG cells and 45.5% for HF cells. CONCLUSION(S): This interspecies bioassay can be utilized to determine and assess the embryonic preimplantation potential of different types of human adult somatic cells.

Animals↗

PubMed2004

Different proteome pattern of epidermal growth factor receptor-positive colorectal cancer cell lines that are responsive and nonresponsive to C225 antibody treatment.

The monoclonal antibody C225 directed against the epidermal growth factor receptor (EGFR) blocks downstream mitogenic signaling and is effective in patients with advanced colorectal cancer. Clinical data, however, suggest the presence of primary and secondary resistance mechanisms that are hardly understood. To define proteins involved in EGFR-triggered growth regulation and potential resistance mechanisms, we characterized the proteome profile of two colorectal cancer cell lines with a high expression of functional EGFR but a different response to treatment with C225. In Caco-2 and HRT-18, a complete saturation of EGFR was achieved after incubation with C225; whereas Caco-2 showed inhibition of proliferation, growth of HRT-18 was not suppressed. Using two-dimensional electrophoresis and subsequent mass spectrometry, we identified 14 proteins differentially expressed in both cell lines. All proteins are involved in metabolic pathways and malignant growth. Expression of enzymes such as ubiquitin carboxyl-terminal hydrolase isozyme 1, glutathione S-transferase P, and chloride intracellular channel protein 1 does not seem to interfere with the antiproliferative effect of anti-EGFR antibody. On the other hand, expression of proteins such as fatty acid binding protein and heat shock protein 27 might constitute strong antiapoptotic effects contributing to the nonresponse of HRT-18 to C225 treatment. Proteome-based investigations can help us better understand the complex protein interactions involved in EGFR signaling and its blockage by therapeutic monoclonal antibodies.

Antibodies, Monoclonal↗

PubMed2003

Calgranulins in cystic fluid and serum from patients with ovarian carcinomas.

Ovarian cancer remains still associated with poor prognosis because it is diagnosed predominantly at advanced stages. Ovarian-specific tumor markers do not yet exist for early detection of the disease. At the search of diagnostic markers for ovarian cancer, proteomic-based approaches have focused on novel investigations of neoplastic processes in tumor patients. Cystic fluids of malignant and benign ovarian tumors and serum from the corresponding patients were collected and processed for two-dimensional gel electrophoresis. Proteins were visualized on the gels by silver staining. At the low molecular mass level between 10 and 20 kDa, selected protein spots were additionally processed for nanospray mass spectrometry and partial amino acid sequencing. For protein identification, the sequencing results were compared with computer information from a protein data bank. Protein patterns from cystic fluids of ovarian carcinomas differed significantly from those of benign cysts and revealed additional polypeptides at low molecular mass level between 10 and 20 kDa. Protein patterns from serum of patients with malignant ovarian tumors also contained additional polypeptides between 10 and 20 kDa that were not detected in serum from patients with benign cysts. The additional proteins in serum were present in similar electrophoretic positions compared with those found in the cystic fluid of the corresponding ovarian carcinomas. Protein spots in the range of 10-20 kDa were selected for partial amino acid sequencing. Two protein spots were identified as calgranulin A and three spots as calgranulin B. Either both proteins or only calgranulin A or B were present in cystic fluid from ovarian carcinomas and serum of the corresponding patients. These two proteins were absent or not detectable in fluid from benign ovarian cysts and in serum from those patients. Our investigations concerning protein patterns in cystic fluid of malignant and benign ovarian tumors provide new information about alterations in protein synthesis linked to neoplastic events of the ovary. With the proteomic strategy, new tumor markers are characterized and may serve for diagnostic purposes of patients with ovarian cancer.

Adult↗

PubMed2002

Heterotopic pregnancy: report of three cases.

OBJECTIVE: Heterotopic pregnancy, defined as concomitant intrauterine and ectopic pregnancy, is a rare event. Assisted reproductive technologies have led to an increase in the number of heterotopic pregnancies. MATERIALS AND METHOD: From 1997 to 1999 three cases of heterotopic pregnancies were referred to the gynecological unit of the hospital of St. Pölten. The condition was diagnosed at 7, 8 and 12 weeks of gestation, respectively. Two patients had undergone assisted reproductive technologies and former pelvic surgery for tubal pregnancy. Two patients had intrauterine singleton pregnancies and one patient had an intrauterine twin pregnancy. In all cases the ectopic site presented as a ruptured tubal pregnancy and the treatment consisted of laparoscopic salpingectomy. RESULTS: In all patients the postoperative course was uneventful and the intrauterine pregnancy progressed. In one case recurrent preterm labor led to vaginal delivery at 33 weeks of pregnancy. In the case of twin pregnancy, a planned cesarean section was performed at 37 weeks of gestation. One patient delivered at term. All newborns were healthy. CONCLUSION: Knowledge of heterotopic pregnancy and understanding the epidemiological risk factors underlying this condition are important for early diagnosis with the aim of improving therapy and clinical outcome.

Adult↗

PubMed2002

Biotechnology in reproductive medicine.

In this review I am summarizing the past and current progress in the field of pharmaceutical, diagnostic, therapeutic, and reproductive cloning in mammals. Several human gene products can be pharmaceutically explored in transgenic farm animals and employed for medical applications. Preimplantation genetic diagnosis (PGD) is utilizing modern molecular cloning techniques to detect genetic and chromosomal aberrations in early embryos originating from patients with inborn errors at risk for hereditary diseases or age-related risk for abnormal karyotype. Stem cell engineering from early human embryos is creating new and promising but also controversial applications for therapeutic and regenerative medicine. Potential risk factors for reproductive cloning are presented and discussed in the context of possible developmental malformations, frequently observed after embryo culture and cloning in farm animals. Future extension of biotechnology to human reproductive cloning is currently under worldwide dispute.

Animals↗

PubMed1984

Illmensee responds.

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Biomedical Research↗