Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
298
result(s) for
"Kliesch, S."
Sort by:
Complementary information concerning the suspected interindividual transmission of GW1516, a substance prohibited in sport, through intimate contact: a case report
2024
Purpose
Inadvertent and/or unknowing exposure to drugs and drug residues has been frequently debated in situations of so-called adverse analytical finding (AAF) in the context of sports drug testing programs. Transfer of drug residues via unprotected intercourse is a conceivable scenario but scientific data and authentic case reports are scarce. Herein, investigations into two AAFs with the peroxisome proliferator-activated receptor delta (PPARδ) agonist GW1516 are reported and discussed.
Methods
To probe for a contamination scenario involving sexual intercourse, two assays were used to determine semenogelin in human urine, with one employing an immunochromatographic lateral flow approach and another based on liquid chromatography–tandem mass spectrometry. Further, drug-residue testing using patients’ ejaculate was conducted by utilizing liquid chromatography in conjunction with a triple quadrupole mass spectrometer, followed by re-analysis of suspect samples (i.e., samples indicating the presence of relevant compounds) using high resolution/high mass accuracy mass spectrometry.
Results
In one case, but not the other, the possibility of intimate contact as the source of the AAF was confirmed after a thorough investigation of potential contamination scenarios. Subsequent research revealed analytical evidence for the presence of seminal fluid in one of the female athlete’s doping control urine samples, and the analysis of clinical ejaculate specimens provided first data on an authentic concentration level of GW1516 and its metabolites in human seminal fluid.
Conclusions
The combined facts substantiate the possibility of an AAF caused by unprotected sexual intercourse and the plausibility of the case-related arguments.
Journal Article
Developmental Expression of the Pluripotency Factor Sal-Like Protein 4 in the Monkey, Human and Mouse Testis: Restriction to Premeiotic Germ Cells
by
Debowski, K.
,
Schlatt, S.
,
Schweyer, S.
in
Animals
,
Callithrix - physiology
,
Cell Nucleus - metabolism
2012
SALL4 (sal-like protein 4) is a pluripotency transcription factor, which is highly expressed in embryonic stem (ES) cells and which is essential for mouse preimplantation development. In adult mouse organs, Sall4 mRNA is highly expressed in the testis and ovary, while there is only little or no expression in other organs. There is also a high expression of SALL4 in human testicular germ cell tumors. However, there is as yet no detailed analysis of SALL4 expression during mammalian testicular development. We analyzed SALL4 expression in ES cells, preimplantation embryos, and the developing and adult testis of a nonhuman primate (NHP) species, the common marmoset monkey (Callithrix jacchus). Immunofluorescence revealed SALL4 in the nuclei of marmoset ES cells and preimplantation embryos. Marmoset SALL4 isoform analysis in ES cells and newborn and adult testis by RT- PCR and Western blotting showed two different isoforms, SALL4-A and SALL4-B. Immunohistochemistry localized this transcription factor to the nuclei of primordial germ cells and most gonocytes in the prenatal and early postnatal marmoset testis. In the pubertal and adult testis SALL4 was present in undifferentiated spermatogonia. In the developing and adult human and mouse testis SALL4 expression mimicked the pattern in the marmoset. Adult testes from additional NHP species, the treeshrew, the cat and the dog also exhibited SALL4 in undifferentiated spermatogonia, indicating a conserved expression in the mammalian testis. Taking into account the importance of SALL4 for mouse development, we conclude that SALL4 may play an important role during mammalian germ cell development and is involved in the regulation of spermatogonial proliferation in the adult testis.
Journal Article
Immunohistochemical characterization of the anti-Müllerian hormone receptor type 2 (AMHR-2) in human testes
2020
PurposeIn males, AMH is secreted by immature Sertoli cells; following exposure to endogenous androgens, Sertoli cells undergo a process of maturation which ultimately inhibits AMH expression to undetectable levels in the serum. However, expression of AMH receptor (AMHR-2) has never been studied in human testes, and high intratubular concentrations of AMH have been reported in recent literature. We therefore assessed expression of AMHR-2 in several testicular tissue samples by immunohistochemistry (IHC).MethodsThe IHC method was first validated on tissue samples from healthy human testis (n = 2) and from marmoset ovary (n = 1). The same method was then used for assessment on testicular histopathology specimens from patients with mixed atrophy (MA, n = 2), spermatogenetic arrest (SA, n = 2), Sertoli cell-only syndrome (SCO, n = 1), Klinefelter syndrome (KS, n = 1), and nonseminomatous germ cell tumors (NSGCT, n = 1). Tissue samples from two subjects at different pubertal stages (AndroProtect (AP), aged 5 and 14 years) with hematological malignancies were also retrieved.ResultsIn adult men, AMHR-2 was expressed on peritubular mesenchymal cells, with patterns closely mirroring α-smooth muscle actin expression. Similar patterns were preserved in almost all conditions; however, in nonseminomatous germ cell tumors the tissue architecture was lost, including AMHR-2 expression. More positive and diffuse staining was observed in tissue samples from prepubertal testes.ConclusionsIn specimens from both healthy and affected testes, AMHR-2 expression appears weaker in adult than in prepubertal tissue sections. The persistence of AMHR-2 expression seemingly hints at a possible effect of intratesticular AMH on the tubular walls.
Journal Article
Can germ cell neoplasia in situ be diagnosed by measuring serum levels of microRNA371a-3p?
2017
Purpose
Diagnosing germ cell neoplasia in situ (GCNis) can detect germ cell tumours (GCTs) at the pre-invasive stage. To date, testicular biopsy with the potential of surgical complications is the only way of safely diagnosing GCNis. Recently, microRNAs (miRs) 371-3, and miR 367 were shown to be valuable serum biomarkers of GCTs. We explored the usefulness of these candidate miRs as a marker for GCNis.
Methods
27 patients with GCNis and no concomitant GCT were enrolled. All patients underwent measuring serum levels of miR-371a-3p and miR-367-3p before treatment, 11 had repeat measurement after treatment, 2 also had testicular vein blood examinations. Serum levels were measured by quantitative PCR. In addition, four orchiectomy specimens of patients with GCT were examined immunohistochemically and by in situ hybridization (ISH) with a probe specific for miR-371a-3p to look for the presence of this miR in GCNis cells.
Results
The median serum level of miR-371a-3p was significantly higher in patients with GCNis than in controls, miR-367 levels were not elevated. Overall, 14 patients (51.9%) had elevated serum levels of miR-371a-3p. The highest levels were found in patients with bilateral GCNis. Levels in testicular vein serum were elevated in both of the cases. After treatment, all elevated levels dropped to normal. In two orchiectomy specimens, miR-371a-3p was detected by ISH in GCNis cells.
Conclusions
Measuring miR-371a-3p serum levels can replace control biopsies after treatment of GCNis. In addition, the test can guide clinical decision making regarding the need of testicular biopsy in cases suspicious of GCNis.
Journal Article
Andrology on the Internet: Most wanted, controversial and often primary source of information for patients
2018
The Internet is an important source of health information with relevant impact on the physician–patient relationship. The German urological associations host one of the most comprehensive platforms for patient information on urological diseases. The aim of the study was to characterise its users and their specific needs. We invited users of the website via pop‐up to complete a 26‐item online survey to evaluate health‐related behaviour, distress and decision‐making preferences. We received n = 551 complete responses. The most frequently requested topics were from the field of andrology (45.4%, n = 250). Of these, the most popular topics were circumcision (28.9%, n = 159) and erectile dysfunction (18.1%; n = 100). Overall, 216 users (39.2%) searched for information prior to their first doctor's appointment, and 89.3% (n = 492) preferred autonomous or shared decision‐making. Users seeking information on circumcision were less frequently under urological treatment (p < .001), and more self‐determined regarding healthcare decisions (p = .01). Circumcision was the only information on the website, which received relevant critical comments. Andrology was the most frequently requested urological topic. The vast majority of patients wanted to take self‐determined healthcare decisions and searched for information prior to a doctor's appointment. This might have an impact on the physician–patient relationship and causes a high demand for good‐quality health information websites.
Journal Article
Radiotherapy with 16 Gy may fail to eradicate testicular intraepithelial neoplasia: preliminary communication of a dose-reduction trial of the German Testicular Cancer Study Group
by
Classen, J
,
Kliesch, S
,
Dieckmann, K
in
Adult
,
Biological and medical sciences
,
Biomedical and Life Sciences
2003
Low-dose radiotherapy to the testis is effective in eradicating testicular intraepithelial neoplasia (TIN, carcinoma
in situ
of the testis) at the risk of androgenic deficiency. The present trial was designed to define the lowest dose effective to control TIN assuming a dose–response relation of radiation-induced endocrinological damage. Patients with TIN in a solitary testicle or with bilateral TIN were treated with 18 Gy (14 patients) and 16 Gy (26 patients) (5 × 2 Gy per week). Biopsies to ascertain clearance of TIN were performed after 6 and 24 months. The median time of follow-up is 20.5 months. There were three adverse events. In one patient, relapse of TIN along with microinvasive seminoma was observed 2 years after 16 Gy irradiation. In two other patients, persistent spermatogonia were observed with the 16 and 18 Gy regimen after 6 and 24 months, respectively. All other post-treatment biopsies showed the Sertoli cell-only pattern. These results confirm that TIN is a radiosensitive lesion efficiently controlled in most cases with doses below 20 Gy. However, sporadic failures may occur. A dose of 16 Gy is probably unsafe and should no longer be used. Future investigations should not only focus on total dosage of irradiation but also on fractionation schedules.
Journal Article
Current insights into the sulfatase pathway in human testis and cultured Sertoli cells
by
Bakhaus, K.
,
Wapelhorst, B.
,
Fietz, D.
in
Anatomy & physiology
,
Biochemistry
,
Biomedical and Life Sciences
2016
Within the human testis, large amounts of sulfated steroid hormones are produced. As shown in breast tissue and placenta, these might not only be excretion intermediates, but re-activated in target cells by steroid sulfatase (STS). This process is called sulfatase pathway and may play a pivotal role in para- and/or intracrine regulation by creating a local supply for steroid hormones. This requires a facilitated transport via uptake carriers and efflux transporters as these hydrophilic molecules cannot pass the cell membrane. Moreover, blood–testis barrier formation in the testis requires a transport through Sertoli cells (SCs) to reach germ cells (GCs). Sertoli cells are therefore expected to play a key role as gate-keepers for sulfatase pathway in human seminiferous epithelium. We analyzed the mRNA and protein expression of uptake carriers and efflux transporters like organic anion-transporting polypeptides (OATP2B1, OATP3A1) and multidrug resistance-related proteins (MRP1, MRP4) in testicular tissue and cultured Sertoli cells (FS1, HSEC). Additionally, expression pattern of STS as well as sulfonating enzymes (SULTs) were assessed. OATP2B1, OATP3A1 and STS were detected in SCs as well as GCs, whereas MRP1 is only expressed in SCs, and SULT1E1 only in Leydig cells, respectively. By transcellular transport of [H
3
]DHEAS in HSEC, we showed a functional transport of sulfated steroids in vitro. Our data indicate that steroid synthesis via sulfatase pathway in Sertoli cells in vivo and in vitro is possible and may contribute to paracrine and intracrine regulation employing the local supply of sulfated and free steroid hormones inside seminiferous tubules.
Journal Article
Seminal plasma (SP) induces a rapid transforming growth factor beta 1 (TGFβ1)—independent up-regulation of epithelial–mesenchymal transdifferentiation (EMT) and myofibroblastic metaplasia-markers in endometriotic (EM) and endometrial cells
by
Kiesel, L.
,
Schäfer, S.
,
Kliesch, S.
in
Ascitic Fluid - metabolism
,
Biomarkers - metabolism
,
Cell Proliferation
2019
Purpose
To study if short-term exposure (2 h and 6 h) of endometrial/endometriotic tissues and cells to 10% seminal plasma (SP) can induce EMT/metaplasia.
Methods
Basic research experimental study was carried out in a University hospital-based fertility center. Semen samples, peritoneal fluid (PF) from endometriosis patients, endometrial biopsy from premenopausal women, immortalized endometriotic epithelial cell line (12Z), and immortalized endometrial stromal cell line (St-T1b) were studied. Rapid stain identification test (RSID), TGFβ1 immunofluorescence of washed sperms, TGFβ1-ELISA of SP and PF, in vitro study (2 h and 6 h incubation) and real-time PCR of endometrial tissue and cell lines to analyze gene expression of EMT/metaplasia markers and mediators were done.
Results
SP is still detectable in washed semen. TGFβ1 was expressed on the plasma membrane of the sperms and was significantly more concentrated in SP (88.17 ng/ml) than PF. 10% SP induced an up-regulation of alpha smooth muscle actin expression in endometrial tissue (
p
= 0.008) and in 12Z cells (
p
= 0.05), mostly TGFβ1-independent. TWIST expression was persistently significantly down-regulated while Snail1 and 2 were up-regulated, though insignificant.
Conclusion
Our results provide novel evidence to support that even in semen washed twice, SP is still detectable. The changes in EMT/metaplasia markers and mediators give a new insight into a possible effect of SP on the pathogenesis of endometriosis.
Journal Article
Transfection of Sertoli cells with androgen receptor alters gene expression without androgen stimulation
2015
Background
Androgens play an important role for the development of male fertility and gained interest as growth and survival factors for certain types of cancer. Androgens act via the androgen receptor (AR/
Ar
), which is involved in various cell biological processes such as sex differentiation. To study the functional mechanisms of androgen action, cell culture systems and AR-transfected cell lines are needed. Transfection of AR into cell lines and subsequent gene expression analysis after androgen treatment is well established to investigate the molecular biology of target cells. However, it remains unclear how the transfection with AR itself can modulate the gene expression even without androgen stimulation. Therefore, we transfected
Ar
-deficient rat Sertoli cells 93RS2 by electroporation using a full length human AR.
Results
Transfection success was confirmed by Western Blotting, immunofluorescence and RT-PCR. AR transfection-related gene expression alterations were detected with microarray-based genome-wide expression profiling of transfected and non-transfected 93RS2 cells without androgen stimulation. Microarray analysis revealed 672 differentially regulated genes with 200 up- and 472 down-regulated genes. These genes could be assigned to four major biological categories (development, hormone response, immune response and metabolism). Microarray results were confirmed by quantitative RT-PCR analysis for 22 candidate genes.
Conclusion
We conclude from our data, that the transfection of
Ar
-deficient Sertoli cells with AR has a measurable effect on gene expression even without androgen stimulation and cause Sertoli cell damage. Studies using AR-transfected cells, subsequently stimulated, should consider alterations in AR-dependent gene expression as off-target effects of the AR transfection itself.
Journal Article
Androprotect and prospects for fertility treatment
by
Kliesch, S
in
Cryopreservation - methods
,
Evidence-Based Medicine
,
Fertility Preservation - methods
2016
Fertility protection is essential for men undergoing potentially gonadotoxic treatment. It is usually offered to adolescents and men in reproductive age by semen cryopreservation. In case of azoospermia, testicular sperm cryopreservation is an additional option. In prepubertal boys no sperm cryopreservation is possible. A purely experimental option is cryopreservation of spermatogonial stem cells in immature testis tissue.
Transplantation of either immature testis tissue or testicular stem cells or spermatogonia generated in vitro from stem cells are possible options for fertility preservation in boys.
In this article, the rationale for cryopreservation of gonadal stem cells and the experimental methods for refertilization are summarized. The current research, national and international clinical and research activities and possible perspectives of further development of fertility preservation are explained.
Journal Article