Michael Guschmann

Charité Universitätsmedizin Berlin, Berlin, Land Berlin, Germany

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Publications (5)9.37 Total impact

  • Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 09/2003; 22(8):823-7; quiz 828-9. · 1.40 Impact Factor
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    ABSTRACT: Chorioangiomas are benign tumors of the hemochorial placenta. They are malformations or hamartomas, formed as a result of defective angiogenesis. They are of clinical importance due to their association with premature placental release and pre-eclampsia. Since a link has been established in neoplasias between tumor growth and an increased expression of angiogenic growth factors, 136 samples of chorioangiomas and 136 samples of tumor-free placental tissue were examined in terms of proliferation rate and expression of the growth factors angiopoietin-1 and -2, the angiopoietin-receptor Tie-2, PDGF and the PDFG beta-receptor. The chorioangiomas exhibited differing proliferation rates, whereas tumor-free placental tissue barely proliferated at all. Angiopoietin expression was--morphologically--considerably higher within the chorioangiomas than in the comparison placentas; morphological amounts of the Tie-2 receptor were identical in all samples. Expression of PDGF and its receptor was the same for chorioangiomas and tumor-free placentas. According to this study and the current literature in the field of hamartomas and some neoplasia, we can assume that increased growth factor expression plays a role in the formation of chorioangiomas, since it stimulates proliferation in a wide variety of cell compartments.
    Journal of Perinatal Medicine 02/2003; 31(2):170-5. · 1.95 Impact Factor
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    ABSTRACT: Chorioangiomas are rare hamartomatous lesions. Possible correlations between their occurrence and the progression of a pregnancy have been objects of discussions for quite some time. In a retrospective study 22439 unselected placentas were examined for incidences of chorioangiomas, morphological features and accompanying clinical characteristics. Chorioangiomas occur in 0.61% of pregnancies, they are mainly microscopically small, and 55% of them are localized subchorial. The rate of their occurrence rises almost linearly with maternal age; chorioangiomas are found most often in women who are over 30 years old. Hypertension and diabetes are found more often in combination with chorioangiomas than they are in otherwise normal pregnancies. In 72% of all cases girls were born; in 33% we also observed malfunctions in the maturation processes of the placental parenchyma, in particular arrested and delayed maturation of the villi. Premature births occur approximately three times more often in chorioangioma pregnancies than in normal ones. Chorioangiomas are often found in primipara and twin pregnancies.
    Journal of Perinatal Medicine 02/2003; 31(2):163-9. · 1.95 Impact Factor
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    ABSTRACT: The authors report the case of a benign renal mesenchymal tumor in a baby boy detected by ultrasound scanning during prenatal diagnosis. Histologically, the tumor was diagnosed as a congenital mesoblastic nephroma (CMN) with myoid differentiation. The tumor normally is characterized by a fascicular proliferation of bland, spindle-shaped cells. CMN is the most common renal tumor in the neonatal period and presumedly results from a neoplastic transformation affecting the pluripotent mesodermal nephric blastema. In embryonic life, tumorigenic influences acting on the nephric blastema might result in selective overgrowth of its mesoblastic derivates. CMN must be differentiated from other spindle-shaped tumors, like Wilms' tumor, rhabdoid tumor of the kidney, clear cell sarcoma, nephrogenic adenofibroma, fibroma and fibrosarcoma, leiomyoma, metanephric stromal tumor, and, in this case especially, from tumors with myoid differentiation like infantile myofibromatosis. Numerical molecular abnormalities are observed frequently in renal mesenchymal tumors, especially in chromosome 11. Cytogenetic findings in our tumor after comparative genomic hybridization (CGH) showed full trisomies of chromosomes 20 and 22q, partial trisomies for the distal part of 11q and 1p, and an approximately full monosomy of chromosome 4 (4qter-4p15). The chromosomal imbalances of the tumor can be described as: rev ish enh(1p31pter,11q23qter,20,22), dim(4)(p15qter).
    Journal of Pediatric Surgery 09/2002; 37(8):E22. · 1.38 Impact Factor
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    ABSTRACT: The present report describes two fetuses, one female and one male, with thus far undescribed skeletal malformations. The mother was a gravida 2, para 0. Both pregnancies were terminated in the second trimester because of multiple congenital anomalies diagnosed ultrasonographically resembling a short rib-polydactyly syndrome. Both fetuses were found to have postaxial hexadactyly of the hands and feet, marked bilateral campomelia of the forearm and shank bones, and a Dandy–Walker cyst. In addition, the fourth ventricle was dilated in the first sibling and the second sibling had an inverse intestinal malrotation. A literature search failed to reveal similar observations. Copyright © 2001 John Wiley & Sons, Ltd.
    Prenatal Diagnosis 04/2001; 21(5):378 - 382. · 2.68 Impact Factor

Publication Stats

24 Citations
9.37 Total Impact Points

Institutions

  • 2003
    • Charité Universitätsmedizin Berlin
      • Department of Obstetrics
      Berlin, Land Berlin, Germany
  • 2001–2003
    • Humboldt-Universität zu Berlin
      • Department of Biology
      Berlín, Berlin, Germany