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Thomas Strowitzki

Publications and source records attributed to Thomas Strowitzki.

23 records · Page 2Linked to original sources
PubMed2003

Glucose transporter proteins (GLUT) in human endometrium: expression, regulation, and function throughout the menstrual cycle and in early pregnancy.

An adequate endometrial glucose metabolism, mediated by facilitative glucose transporter molecules (GLUT), is an essential part of endometrial differentiation and decidualization to provide a nutritional and receptive milieu. In human endometrium, only the GLUT1 and GLUT3 isoforms are expressed, whereas glucose transporters, involved in insulin-dependent glucose uptake (GLUT2, GLUT4, GLUT8), could not be detected. Messenger RNA expression, analyzed by RNase protection assay, of both isoforms increased in total endometrium throughout the secretory phase and in decidua. Analysis of mRNA expression in isolated epithelial cells, stromal cells, and CD45 positive leukocytes revealed that increase of GLUT1 expression was due to increasing stromal expression, whereas increase of GLUT3 was due to its expression in CD45-positive immune cells. In vitro, GLUT1 and GLUT3 were not directly regulated by 17beta-estradiol, progesterone, or IL-1beta, IL-6, and leukemia inhibitory factor, but GLUT1 mRNA increased progressively in stromal cells, decidualized in vitro. Inhibition of glucose transporters by cytochalasin B reduced stromal glucose uptake and stromal decidualization. In idiopathic infertile patients, GLUT1 expression in midsecretory endometrium was suppressed. The suppression was caused by reduced stromal expression. Our results suggest stromal GLUT to play a role in the regulation of endometrial function and be compromised in the preparation of the endometrium for the implanting embryo.

Adult↗
PubMed2002

Role of integrins in invasion of endometrial cancer cell lines.

OBJECTIVE: The objective of this study was to determine whether there is a link between integrins and components of the plasminogen system, regarding tumor cell invasion to the artificial extracellular matrix. METHODS: Immunocytochemistry was performed with antibodies directed against integrins alpha2beta1, alpha4beta1, alpha5beta1, alpha6beta1, and alpha(nu)beta3 Cell adhesion was studied by cell attachment to matrix proteins. Integrin-mediated migration of cells into the artificial matrix was studied in an invasion assay. Last, immunoreactivity of the components of the plasminogen system was estimated by ELISA. RESULTS: HEC-1A, Ishikawa, and AN3CA cell lines express the alpha 4 beta 1, alpha 5 beta 1, and alpha 6 beta 1 integrins. Adhesion of cells to fibronectin and laminin was inhibited by monoclonal antibodies directed against appropriate integrin subunits. Migration into the matrigel was partially blocked with mAbs to alpha4beta1 as well as alpha5beta1, alpha6beta1 integrins and their combination. No differences in either uPA or PAI-1 immunoreactivity were found after addition of the mAbs. CONCLUSION: Alpha4beta1, alpha5beta1, and alpha6beta1 heterodimers mediate adhesion as well as migration into the artificial matrix matrigel of endometrial tumor cell lines. A cooperative signaling between these integrins and uPA or its inhibitor in modulation of in vitro cell invasion is rather unprobable.

Antibodies, Monoclonal↗
PubMed2002

Are zinc levels in seminal plasma associated with seminal leukocytes and other determinants of semen quality?

OBJECTIVE: To evaluate a potential association of zinc levels with seminal leukocytes, the outcome of semen cultures; and semen quality and sperm fertilizing capacity. DESIGN: Prospective study. SETTING: Outpatient infertility clinic of a university hospital. PATIENT(S): Two hundred fifty-six randomly chosen asymptomatic males from subfertile couples. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Determination of zinc in seminal plasma by flame atomic absorption spectroscopy. In aliquots of the same ejaculates the following tests were performed: immunocytochemical round cell differentiation to determine leukocyte counts and ratios, microbial screening, and comprehensive evaluation of semen quality (sperm analysis, biochemical parameters, antisperm antibody testing, and in vitro examination of sperm ability to penetrate cervical mucus). The patients underwent medical history, clinical examination, and postcoital testing. Subsequent fertility was determined (controlled for female infertility factors). RESULT(S): The concentration of zinc in seminal plasma did not correlate in a statistically significant way with leukocytes in semen, nor was it associated with bacterial colonization. There was no statistically significant relationship of zinc in seminal plasma or serum with semen quality parameters nor with local antisperm antibody testing of the IgG or IgA class. Zinc levels did not influence sperm capacity to penetrate cervical mucus in vitro or in vivo, and did not affect subsequent fertility. CONCLUSION(S): The zinc level in seminal fluid and serum is not associated with silent male genital tract infection (indicated by seminal leukocytes); nor is it related to semen cultures in asymptomatic individuals. The lack of association with other semen quality parameters indicates that the routine determination of zinc levels during infertility investigation is not recommended.

Adult↗
PubMed2002

Seminal antibodies to human 60kd heat shock protein (HSP 60) in male partners of subfertile couples.

BACKGROUND: Heat shock proteins (HSP) are essential mammalian and bacterial stress proteins. At the cellular level, they act as chaperones, have important regulatory functions, and are considered to be an essential factor for reproduction. Scarce information exists on the role of sensitization to HSP and the potential role in the aetiology of male infertility. METHODS: The potential association of immunoglobulin (Ig)A antibodies (Ab) to the human 60 kDa heat shock protein (HSP 60) with several parameters of subclinical male genital tract infection/inflammation and with semen quality and sperm fertilizing capacity was analysed in a prospective study. IgA Ab to human HSP 60 were determined in seminal plasma of 202 randomly chosen male partners of subfertile couples with a median duration of infertility of 4 years (range 1-15 years), who were asymptomatic for genital tract infection. After medical history and clinical examination, a comprehensive evaluation of semen quality, in aliquots of the same ejaculates used for HSP Ab determination, included: sperm analysis; local antisperm antibody (ASA) screening; standardized sperm-cervical mucus (CM) penetration testing; immunocytochemical round cell differentiation to determine seminal leukocyte counts; evaluation of complement fraction C(3) and of some pro-inflammatory cytokines; and microbial screening. Subsequent fertility was recorded after 6 months. RESULTS: The presence of HSP 60 IgA Ab in seminal fluid (total positive 6.9%) was significantly associated with leukocytospermia, the presence of C(3), and also with high interleukin (IL) levels in seminal plasma. HSP 60 Ab were not related to the bacterial colonization of ejaculates. There was no association of seminal IgA Ab to human HSP 60 with semen quality, determined with microscopical semen analysis, nor with local IgG- or IgA-class ASA. There was no relationship with sperm intrinsic motility and duration of motility in the sperm CM-penetration test, nor with sperm fertilizing capacity. CONCLUSIONS: The combined presence of IgA Ab to human 60 kDa HSP, leukocytes and other established infection/inflammation markers in semen might suggest a potential role of the immune response to heat shock proteins (HSP) in cases of silent male genital tract infection, but the results do not indicate a marked relationship of HSP 60 Ab in seminal fluid with standard parameters of semen quality.

Adult↗