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  1. Book ; Online: Cryptorchidism: Causes and Consequences

    Ivell, Richard / Spencer Barthold, Julia

    2019  

    Keywords Medicine ; Endocrinology ; Cryptorchidism ; congenital condition ; testicular dysgenesis syndrome (TDS) ; fetal
    Size 1 electronic resource (95 pages)
    Publisher Frontiers Media SA
    Document type Book ; Online
    Note English ; Open Access
    HBZ-ID HT021231257
    ISBN 9782889632848 ; 2889632849
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

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  2. Article: Proper Application of Antibodies for Immunohistochemical Detection: Antibody Crimes and How to Prevent Them

    Ivell, Richard

    Endocrinology, 155(3): 676-687

    2014  

    Abstract: For several decades antibodies raised against specific proteins, peptides, or peptide epitopes have proven to be versatile and very powerful tools to demonstrate molecular identity in cells and tissues. New techniques of immunohistochemistry and ... ...

    Institution Leibniz-Institut für Nutztierbiologie
    Abstract For several decades antibodies raised against specific proteins, peptides, or peptide epitopes have proven to be versatile and very powerful tools to demonstrate molecular identity in cells and tissues. New techniques of immunohistochemistry and immunofluorescence have improved both the optical resolution of such protein identification as well as its sensitivity, particularly through the use of amplification methodology. However, this improved sensitivity has also increased the risks of false-positive and false-negative staining and thereby raised the necessity for proper and adequate controls. In this review, the authors draw on many years of experience to illuminate many of the more common errors and problematic issues in immunohistochemistry, and how these may be avoided. A key factor in all of this is that techniques need to be properly documented and especially antibodies and procedures must be adequately described. Antibodies are a valuable and shared resource within the scientific community; it is essential therefore that mistakes involving antibodies and their controls are not perpetuated through inadequate reporting in the literature.
    Language English
    Document type Article
    Database Repository for Life Sciences

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  3. Article: Cryptorchidism in the Orl Rat Is Associated with Muscle Patterning Defects in the Fetal Gubernaculum and Altered Hormonal Signaling

    Anand-Ivell, Ravinder / Ivell, Richard

    Biology of reproduction, 91(2): 41

    2014  

    Abstract: Cryptorchidism, or undescended testis, is a common male genital anomaly of unclear etiology. Hormonal stimulation of the developing fetal gubernaculum by testicular androgens and insulin-like 3 (INSL3) is required for testicular descent. In studies of ... ...

    Institution Leibniz-Institut für Nutztierbiologie
    Abstract Cryptorchidism, or undescended testis, is a common male genital anomaly of unclear etiology. Hormonal stimulation of the developing fetal gubernaculum by testicular androgens and insulin-like 3 (INSL3) is required for testicular descent. In studies of the orl fetal rat, one of several reported strains with inherited cryptorchidism, we studied hormone levels, gene expression in intact and hormone-stimulated gubernaculum, and imaging of the developing cremaster muscle facilitated by a tissue clearing protocol to further characterize development of the orl gubernaculum. Abnormal localization of the inverted gubernaculum was visible soon after birth. In the orl fetus, testicular testosterone, gubernacular androgen-responsive transcript levels, and muscle-specific gene expression were reduced. However, the in vitro transcriptional response of the orl gubernaculum to androgen was largely comparable to wild type (wt). In contrast, increases in serum INSL3, gubernacular INSL3-responsive transcript levels, expression of the INSL3 receptor, Rxfp2, and the response of the orl gubernaculum to INSL3 in vitro all suggest enhanced activation of INSL3/RXFP2 signaling in the orl rat. However, DNA sequence analysis did not identify functional variants in orl Insl3. Finally, combined analysis of the present and previous studies of the orl transcriptome confirmed altered expression of muscle and cellular motility genes, and whole mount imaging revealed aberrant muscle pattern formation in the orl fetal gubernaculum. The nature and prevalence of developmental muscle defects in the orl gubernaculum are consistent with the cryptorchid phenotype in this strain. These data suggest impaired androgen and enhanced INSL3 signaling in the orl fetus accompanied by defective cremaster muscle development.
    Keywords cryptorchidism ; androgen receptor ; gubernaculum ; insulin-like 3 ; male reproductive tract
    Language English
    Document type Article
    Database Repository for Life Sciences

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  4. Article: Brief maternal exposure of rats to the xenobiotics dibutyl phthalate or diethylstilbestrol alters adult-type Leydig cell development in male offspring

    Ivell, Richard / Anand-Ivell, Ravinder

    Asian journal of andrology, 15(2):261-268

    2013  

    Abstract: Maternal exposure to estrogenic xenobiotics or phthalates has been implicated in the distortion of early male reproductive development, referred to in humans as the testicular dysgenesis syndrome. It is not known, however, whether such early gestational ... ...

    Institution Leibniz-Institut für Nutztierbiologie
    Abstract Maternal exposure to estrogenic xenobiotics or phthalates has been implicated in the distortion of early male reproductive development, referred to in humans as the testicular dysgenesis syndrome. It is not known, however, whether such early gestational and/or lactational exposure can influence the later adult-type Leydig cell phenotype. In this study, Sprague–Dawley rats were exposed to dibutyl phthalate (DBP; from gestational day (GD) 14.5 to postnatal day (PND) 6) or diethylstilbestrol (DES; from GD14.5 to GD16.5) during a short gestational/lactational window, and male offspring subsequently analysed for various postnatal testicular parameters. All offspring remained in good health throughout the study. Maternal xenobiotic treatment appeared to modify specific Leydig cell gene expression in male offspring, particularly during the dynamic phase of mid-puberty, with serum INSL3 concentrations showing that these compounds led to a faster attainment of peak values, and a modest acceleration of the pubertal trajectory. Part of this effect appeared to be due to a treatment-specific impact on Leydig cell proliferation during puberty for both xenobiotics. Taken together, these results support the notion that maternal exposure to certain xenobiotics can also influence the development of the adult-type Leydig cell population, possibly through an effect on the Leydig stem cell population.
    Keywords INSL3 ; Leydig cells ; dibutyl phthalate (DBP) ; diethylstilbestrol (DES) ; puberty ; testis
    Language English
    Document type Article
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  5. Article: Functional link between bone morphogenetic proteins and insulin-like peptide 3 signaling in modulating ovarian androgen production

    Ivell, Richard / Anand-Ivell, Ravinder

    Proceedings of the National Academy of Sciences of the United States of America, 10(15): E1426-E1435

    2013  

    Abstract: Bone morphogenetic proteins (BMPs) are firmly implicated as intra-ovarian regulators of follicle development and steroidogenesis. Here we report a microarray analysis showing that treatment of cultured bovine theca cells (TC) with BMP6 significantly (> ... ...

    Institution Leibniz-Institut für Nutztierbiologie
    Abstract Bone morphogenetic proteins (BMPs) are firmly implicated as intra-ovarian regulators of follicle development and steroidogenesis. Here we report a microarray analysis showing that treatment of cultured bovine theca cells (TC) with BMP6 significantly (>twofold; P < 0.01) up- or down-regulated expression of 445 genes. Insulin-like peptide 3 (INSL3) was the most heavily down-regulated gene (−43-fold) with cytochrome P450, subfamily XVII (CYP17A1) and other key steroidogenic transcripts including steroidogenic acute regulatory protein (STAR), cytochrome P450 family 11, subfamily A1 (CYP11A1) and 3 beta-hydroxysteroid dehydrogenase type 1 (HSD3B1) also down-regulated. BMP6 also reduced expression of nuclear receptor subfamily 5A1 (NR5A1) known to target the promoter regions of the aforementioned genes. Real-time PCR confirmed these findings and also revealed a marked reduction in expression of INSL3 receptor, relaxin/insulin-like family peptide receptor 2 (RXFP2). Secretion of INSL3 protein and androstenedione were also suppressed suggesting a functional link between BMP and INSL3 pathways in controlling androgen synthesis. RNAi-mediated knockdown of INSL3 reduced INSL3 mRNA (75%) and protein (94%) level and elicited a 77% reduction in CYP17A1 mRNA and 83% reduction in androstenedione secretion. Knockdown of RXFP2 also reduced CYP17A1 expression (81%) and androstenedione secretion (88%). Conversely, treatment with exogenous (human) INSL3 increased androstenedione secretion ∼twofold. The CYP17A1 inhibitor abiraterone abolished androgen secretion and reduced expression of both INSL3 and RXFP2. Collectively, these findings indicate a positive autoregulatory role for INSL3 signaling in maintaining thecal androgen production, and visa versa. Moreover, BMP6-induced suppression of thecal androgen synthesis may be mediated, at least in part, by reduced INSL3-RXFP2 signaling.
    Keywords growth factor ; ovary ; reproduction
    Language English
    Document type Article
    Database Repository for Life Sciences

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  6. Article: Models of in vitro spermatogenesis

    Anand-Ivell, Ravinder / Ivell, Richard

    Spermatogenesis, 2(1):32–43

    2012  

    Abstract: Understanding the mechanisms that lead to the differentiation of male germ cells from their spermatogonial stem cells through meiosis to give rise to mature haploid spermatozoa has been a major quest for many decades. Unlike most other cell types this ... ...

    Institution Leibniz-Institut für Nutztierbiologie
    Abstract Understanding the mechanisms that lead to the differentiation of male germ cells from their spermatogonial stem cells through meiosis to give rise to mature haploid spermatozoa has been a major quest for many decades. Unlike most other cell types this differentiation process is more or less completely dependent upon the cells being located within the strongly structured niche provided by mature Sertoli cells within an intact seminiferous epithelium. While much new information is currently being obtained through the application and description of relevant gene mutations, there is still a considerable need for in vitro models with which to explore the mechanisms involved. Not only are systems of in vitro spermatogenesis important for understanding the basic science, they have marked pragmatic value in offering ex vivo systems for the artificial maturation of immature germ cells from male infertility patients, as well as providing opportunities for the transgenic manipulation of male germ cells. In this review, we have summarized literature relating to simplistic culturing of germ cells, co-cultures of germ cells with other cell types, especially with Sertoli cells, cultures of seminiferous tubule fragments, and briefly mention the opportunities of xenografting larger testicular pieces. The majority of methods are successful in allowing the differentiation of small steps in the progress of spermatogonia to spermatozoa; few tolerate the chromosomal reduction division through meiosis, and even fewer seem able to complete the complex morphogenesis which results in freely swimming spermatozoa. However, recent progress with complex culture environments, such as 3-d matrices, suggest that possibly success is now not too far away.
    Language English
    Document type Article
    Database Repository for Life Sciences

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  7. Article: Phthalates and Perfluorooctanesulfonic Acid in Human Amniotic Fluid: Temporal Trends and Timing of Amniocentesis in Pregnancy

    Ivell, Richard / Anand-Ivell, Ravinder

    Environmental health perspectives, 120(6): 897-903

    2012  

    Abstract: BACKGROUND: Measures of prenatal environmental exposures are important, and amniotic fluid levels may directly reflect fetal exposures during hypothesized windows of vulnerability. OBJECTIVES: We aimed to detect various phthalate metabolites and ... ...

    Institution Leibniz-Institut für Nutztierbiologie
    Abstract BACKGROUND: Measures of prenatal environmental exposures are important, and amniotic fluid levels may directly reflect fetal exposures during hypothesized windows of vulnerability. OBJECTIVES: We aimed to detect various phthalate metabolites and perfluorooctanesulfonic acid (PFOS) in human amniotic fluid, to study temporal exposure trends, and to estimate potential associations with gestational week of amniocentesis and maternal age and parity at amniocentesis. METHODS: We studied 300 randomly selected second-trimester amniotic fluid samples from a Danish pregnancy-screening biobank covering 1980 through 1996. We used only samples from male offspring pregnancies. We assayed the environmental pollutants by liquid chromatography/triple quadrupole mass spectrometry and analyzed data using generalized linear regression models. RESULTS: We detected the di(2-ethylhexyl) phthalate (DEHP) metabolite mono(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP) at a median concentration of 0.27 ng/mL [interquartile range (IQR): 0.20–0.37 ng/mL], the diisononyl phthalate (DiNP) metabolite mono(4-methyl-7-carboxyheptyl) phthalate (7cx-MMeHP) at 0.07 ng/mL (IQR: 0.05–0.11 ng/mL), and PFOS at 1.1 ng/mL (IQR: 0.66–1.60 ng/mL). An increase of 1 calendar year was associated with 3.5% lower [95% confidence interval (CI): –4.8%, –2.1%] 5cx-MEPP levels and with 7.1% higher (95% CI: 5.3%, 9.0%) 7cx-MMeHP levels. For each later gestational week of amniocentesis, 5cx-MEPP was 9.9% higher (95% CI: 4.8%, 15.2%), 7cx-MMeHP was 8.6% higher (95: CI: 2.7%, 14.9%), and PFOS was 9.4% higher (95: CI: 3.3%, 15.9%). We observed no associations with maternal age or parity. CONCLUSIONS: Measured metabolite levels appeared to parallel decreasing DEHP exposure and increasing DiNP exposure during the study period. The environmental pollutant levels were positively associated with later gestational age at amniocentesis during pregnancy weeks 12–22.
    Keywords amniotic fluid ; amniocentesis ; biobank ; biomonitoring ; perfluorinated compounds ; phthalates ; pregnancy ; temporal trend
    Language English
    Document type Article
    Database Repository for Life Sciences

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  8. Article: INSL3 in the Ruminant: A Powerful Indicator of Gender- and Genetic-Specific Feto-Maternal Dialogue

    Anand-Ivell, Ravinder / Ivell, Richard

    PLOS ONE, 6(5): e19821

    2011  

    Abstract: The hormone Insulin-like peptide 3 (INSL3) is a major secretory product of the Leydig cells from both fetal and adult testes. Consequently, it is a major gender-specific circulating hormone in the male fetus, where it is responsible for the first phase ... ...

    Institution Leibniz-Institut für Nutztierbiologie
    Abstract The hormone Insulin-like peptide 3 (INSL3) is a major secretory product of the Leydig cells from both fetal and adult testes. Consequently, it is a major gender-specific circulating hormone in the male fetus, where it is responsible for the first phase of testicular descent, and in the adult male. In most female mammals, circulating levels are very low, corresponding to only a small production of INSL3 by the mature ovaries. Female ruminants are exceptional in exhibiting high INSL3 gene expression by the thecal cells of antral follicles and by the corpora lutea. We have developed a specific and sensitive immunoassay to measure ruminant INSL3 and show that, corresponding to the high ovarian gene expression, non-pregnant adult female sheep and cows have up to four times the levels observed in other female mammals. Significantly, this level declines during mid-pregnancy in cows carrying a female fetus, in which INSL3 is undetectable. However, in cows carrying a male fetus, circulating maternal INSL3 becomes elevated further, presumably due to the transplacental transfer of fetal INSL3 into the maternal circulation. Within male fetal blood, INSL3 is high in mid-pregnancy (day 153) corresponding to the first transabdominal phase of testicular descent, and shows a marked dependence on paternal genetics, with pure bred or hybrid male fetuses of Bos taurus (Angus) paternal genome having 30% higher INSL3 levels than those of Bos indicus (Brahman) paternity. Thus INSL3 provides the first example of a gender-specific fetal hormone with the potential to influence both placental and maternal physiology.
    Keywords Cattle ; Amniotic fluid ; Blood ; Genetics ; Fetuses ; Placenta ; Progesterone ; Ruminants
    Language English
    Document type Article
    Database Repository for Life Sciences

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  9. Article: The Physiology of Reproduction -

    Ivell, Richard / Anand-Ivell, Ravinder

    Frontiers in physiology

    2021  Volume 12, Page(s) 650550

    Abstract: The reproductive system in males and females reflects a highly dynamic underlying physiology. Yet our current understanding of this system is still largely based upon relatively simplistic snapshots of individual component cells and tissues. Gamete ... ...

    Abstract The reproductive system in males and females reflects a highly dynamic underlying physiology. Yet our current understanding of this system is still largely based upon relatively simplistic snapshots of individual component cells and tissues. Gamete production as well as gonadal hormone synthesis and its influence are the manifestations of dynamic and redundant informational networks and processes, whose qualitative and quantitative dimensions, especially through development from embryo through puberty and adulthood into ageing, are still largely uncharted. Whilst the recent huge advances in molecular science have helped to describe the components of the reproductive system in ever greater detail, how these interact and function in space and time dimensions is still largely obscure. Recent developments in microfluidics, stem cell biology, and the integration of single-cell transcriptomics with tissue dynamics are offering possible methodological solutions to this issue. Such knowledge is essential if we are to understand not only the normal healthy functioning of this system, but also how and why it is affected in disease or by external impacts such as those from environmental endocrine disruptors, or in ageing. Moreover, operating within a complex network of other physiological systems, its integrational capacity is much more than the generation of male and female gametes and their roles in fertility and infertility; rather, it represents the underpinning support for health and well-being across the lifespan, through pregnancy, puberty, and adulthood, into old age.
    Language English
    Publishing date 2021-03-30
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2564217-0
    ISSN 1664-042X
    ISSN 1664-042X
    DOI 10.3389/fphys.2021.650550
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Research in Reproduction: Challenges, Needs, and Opportunities.

    Ivell, Richard

    Frontiers in physiology

    2017  Volume 8, Page(s) 46

    Language English
    Publishing date 2017-02-08
    Publishing country Switzerland
    Document type Editorial
    ZDB-ID 2564217-0
    ISSN 1664-042X
    ISSN 1664-042X
    DOI 10.3389/fphys.2017.00046
    Database MEDical Literature Analysis and Retrieval System OnLINE

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