G Brabant

Universitätsklinikum Schleswig - Holstein, Kiel, Schleswig-Holstein, Germany

Are you G Brabant?

Claim your profile

Publications (240)899.03 Total impact

  • B. Harbeck, A. Marxsen, G. Brabant
    [Show abstract] [Hide abstract]
    ABSTRACT: Funktionsveränderungen der mütterlichen Schilddrüse beeinflussen die frühe fetale Entwicklung. Die Schilddrüsenhormone Trijodthyronin (T3) und Thyroxin (T4) sind für die Entwicklung und das Aufrechterhalten physiologischer Prozesse zwingend erforderlich. Dies gilt insbesondere für das Zentralnervensystem (ZNS); hier sind Schilddrüsenhormone von erheblicher Bedeutung bei der Reifung des fetalen Gehirns während der Schwangerschaft. Neben Schilddrüsenerkrankungen kommt dem Jodmangel erhebliche Bedeutung zu. Während der Schwangerschaft steigt der Bedarf an Schilddrüsenhormonen und entsprechend an Jod um etwa 50 % an. Die gesunde Schilddrüse kann diesen Mehrbedarf decken, sofern eine ausreichende Jodversorgung gewährleistet ist. Der vorliegende Beitrag beschreibt die Vorgänge der fetalen und maternalen Schilddrüsenhormonproduktion und geht im Besonderen auf die physiologischen Veränderungen der mütterlichen Schilddrüsenparameter während der Schwangerschaft ein. Besondere Berücksichtigung finden Schilddrüsenfunktionsstörungen bei Mutter und Fetus. Abstract Functional alterations of maternal thyroid glands influence early fetal development. The thyroid gland hormones triiodothyronine (T3) and thyroxine (T4) are absolutely necessary for the development and maintenance of physiological processes. This is especially true for the central nervous system (CNS) where the thyroid gland hormones play an important role in maturation of the fetal brain during pregnancy. In addition to thyroid gland diseases, iodine deficiency is also extremely important. During pregnancy the requirements for thyroid gland hormones increase by approximately 50 % with a corresponding need for iodine. Healthy thyroid glands can cover these increased requirements as long as sufficient iodine is available. This article describes the processes of fetal and maternal thyroid hormone production and in particular the physiological alterations of maternal thyroid gland parameters during pregnancy. Particular attention is paid to disorders of thyroid gland function in the mother and fetus.
    Gynäkologische Endokrinologie 05/2014; 12(2):96-102.
  • H. Biersack, G. Brabant
    [Show abstract] [Hide abstract]
    ABSTRACT: Spätschäden einer Krebserkrankung sind durch die therapiebedingt verbesserten Überlebensraten ein rasch zunehmendes, aber bislang zu wenig wahrgenommenes Problem. Zu diesen Folgeerkrankungen, die definitionsgemäß Jahre nach der initialen Erkrankung auftreten, zählen nicht nur Zweittumoren, sondern auch eine Reihe nichtonkologischer internistischer Probleme. Diese kardiovaskulären, gastrointestinalen, renalen oder endokrinen Spätschäden wurden bislang unzureichend beachtet und müssen bei der häufig schleichenden Symptomatik gezielt adressiert werden.
    Der Internist 12/2013; 54(10). · 0.27 Impact Factor
  • H Biersack, G Brabant
    [Show abstract] [Hide abstract]
    ABSTRACT: Due to therapy-associated improvements in survival rates, delayed effects of cancer are a rapidly increasing but as yet only poorly recognized problem. These delayed sequelae, which by definition occur years after the primary disease, include secondary tumors and many non-oncological internal medical problems. Little attention has so far been paid to the cardiovascular, gastrointestinal, renal and endocrinal delayed side effects and must be specifically addressed due to the often slowly progressing symptoms.
    Der Internist 09/2013; · 0.27 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Headache is very common in pituitary disease and is reported to be present in more than a third of all patients with pituitary adenomas. Tumour size, cavernous sinus invasion, traction or displacement of intracranial pain-sensitive structures such as blood vessels, cranial nerves and dura mater, and hormonal hypersecretion are implicated causes. The present review attempts to systematically review the literature for any combination of headache and pituitary or hormone overproduction or deficiency. Most data available are retrospective and/or not based on the International Headache Society (IHS) classification. Whereas in pituitary apoplexy a mechanical component explains the almost universal association of the condition with headaches, this correlation is less clear in other forms of pituitary disease and a positive impact of surgery on headaches is not guaranteed. Similarly, invasion into the cavernous sinus or local inflammatory changes have been linked to headaches without convincing evidence. Some studies suggest that oversecretion of GH and prolactin may be important for the development of headaches and treatment, particularly with somatostatin analogues, has been shown to improve symptoms in these patients. Otherwise, treatment rests on general treatment options for headaches based an accurate clinical history and a precise classification which includes assessment of the patient's psychosocial risk factors. This article is protected by copyright. All rights reserved.
    Clinical Endocrinology 08/2013; · 3.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Direct measurement of arginine-vasopressin/antidiuretic hormone (AVP/ADH) concentrations is not included in the standard diagnostic procedures for paraneoplastic syndrome of inappropriate ADH secretion (SIADH). Here, we evaluate the potential of copeptin measurement as a surrogate marker of AVP/ADH secretion for the direct diagnosis of suspected SIADH in cancer patients. Forty-six unselected cancer patients with serum sodium concentrations permanently below 135 mmol/L were included in this study. We compared standard diagnostic criteria for SIADH to the measurement of plasma copeptin in relation to osmolality. Normative data for comparison were constructed from 24 healthy controls studied under basal conditions, experimental dehydration, and hypotonic hypervolemia as well as from 222 hospital patients with no suspicion of an altered ADH regulation. Log transformation of copeptin revealed a linear relationship to plasma osmolality in the controls (R = 0.495, p < 0.001). Compared to these normative data, copeptin levels in most cancer patients were inappropriately high for plasma osmolality and were not significantly correlated. These results, suggestive for paraneoplastic SIADH, could be confirmed by conventional diagnostic procedures for SIADH. Current strategies to diagnose SIADH are difficult to perform under outpatients conditions. Our approach allows screening from a single plasma sample for true paraneoplastic ADH oversecretion and thus rapid selection for a specific therapy with an AVP receptor antagonist.
    Endocrine 03/2013; · 3.53 Impact Factor
  • Experimental and Clinical Endocrinology & Diabetes 03/2013; 121(03). · 1.76 Impact Factor
  • Experimental and Clinical Endocrinology & Diabetes 03/2013; 121(03). · 1.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study is to examine potential implications of changes in the approach to adult growth hormone (GH) replacement (GHR) over the last 15 years. Therefore, we analysed the German KIMS database as one of the largest single country pharmacoepidemiological databases on adult GH deficiency (GHD). Based on the date of their first GH application patients were assigned to three intervals (1995-1999, 2000-2004, 2005-2009). A multivariate analysis of variance with interval and sex as independent variables was conducted. Differences were analysed with respect to IGF-I standard deviation score (SDS), quality of life, latency between GHD diagnosis and first GH dose, body mass index, waist-hip ratio, lipid profile, and GH dose. All analyses were conducted at baseline, 1 year, and 3 years of GHR. We detected significant associations between time interval and patient characteristics at baseline and with treatment effects. Recently, patients with less severe GHD (mean IGF-I SDS: -2.1, -1.6, -1.0 in the 1st, 2nd and 3rd interval; p = 0.000) are treated with lower GH starting doses (mean 0.30, 0.19, 0.21 mg/day in the 1st, 2nd and 3rd interval; p = 0.000). In the first time interval, IGF-I SDS was not normalized in females after 3 years of GHR. The results of our analysis demonstrate prominent changes in patient characteristics and handling of GHR. They highlight that approach to therapy and patient inclusion criteria change over time and may represent an important confounder for any analysis in epidemiological surveillance surveys.
    Pituitary 07/2012; · 2.22 Impact Factor
  • C Hubold, G Brabant
    [Show abstract] [Hide abstract]
    ABSTRACT: Ectopic hormone production is a rare complication in neuroendocrine tumors. Tumors producing corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) are most commonly observed, leading to the classical symptoms of Cushing’s syndrome. Additionally, a very low percentage of neuroendocrine tumors can produce growth hormone-releasing hormone (GHRH) leading to classical features of acromegaly. Moreover, ectopic antidiuretic hormone (ADH) secretion has been described in neuroendocrine tumors presenting as hyponatremia due to the syndrome of inappropriate ADH secretion. Other ectopic hormone secretions, such as paraneoplastic gonadotropin release are rarely observed. Ectopic hormone secretion is not usually associated with a detectable pituitary mass and diagnosis is based on the measurement of circulating peptides. This is frequently assisted by imaging techniques, such as somatostatin receptor scintigraphy. Therapeutically a curative approach is the primary goal but in advanced tumors palliative treatment aims to control symptoms with the help of specific antihormonal compounds, such as somatostatin analogues.
    Der Internist 02/2012; 53(2):145-51. · 0.27 Impact Factor
  • Dr. B. Harbeck, G. Brabant
    [Show abstract] [Hide abstract]
    ABSTRACT: Schilddrüsenfunktionsstörungen beeinflussen die Fertilität von Frauen wie auch von Männern. Wesentliche Pathomechanismen sind die durch eine Hypothyreose bedingte Hyperprolaktinämie sowie eine Änderung der Plasmabindungsaktivität des sexualhormonbindenden Globulins (SHBG). Bei Männern können klinisch insbesondere Erektionsstörungen und eine Verminderung der Spermienqualität auftreten, während bei Frauen Zyklusstörungen (Amenorrhö, Oligomenorrhö) im Vordergrund stehen. Es gibt deutliche Hinweise, dass schon eine subklinische Hypothyreose zu einer Störung der Fertilität führen kann, weshalb bei Vorliegen einer Infertilität die Schilddrüsenfunktion überprüft werden sollte. Obwohl die aktuelle Datenlage noch keine abschließenden Aussagen zulässt, erscheint die Substitutionstherapie mit dem Ziel eines optimalen Thyreotropin(TSH)-Spiegels von 1–2 mIE/l sinnvoll, da auf diese Weise in einzelnen Studien die Chance auf Fertilität und erfolgreiche Schwangerschaften erhöht wurde. Die Hyperthyreose führt über eine Stimulation von SHBG bei beiden Geschlechtern zu erhöhten Gesamttestosteron- und Östradiolspiegeln. Klinisch stehen bei der Frau auch hier Zyklusstörungen im Vordergrund. Auch wenn die Studienlage insgesamt unzureichend ist, gibt es bei Männern Hinweise auf eine erhöhte Prävalenz von Erektionsstörungen sowie eine verminderte Spermienzahl und -motilität. Die Prävalenz einer subklinischen oder manifesten Hyperthyreose beträgt bei infertilen Frauen 2,1% und ist somit vergleichbar zur Häufigkeit in einer fertilen Population.
    Gynäkologische Endokrinologie 02/2012; 10(1).
  • Endocrine Practice 01/2012; 18(3):325-34. · 2.59 Impact Factor
  • Annals of Oncology 12/2011; 22(12):2696. · 6.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The clinical picture of pituitary abscesses may resemble features of other pituitary pathologies including endocrine deficiencies. The characteristic radiological changes, namely the ring enhancement, may aid in the diagnostic work-up of this very rare condition. A 40-year-old patient with longstanding HIV infection presented with headache and fatigue. Testing for pituitary function confirmed panhypopitutarism. MRI scanning demonstrated an inhomogeneous pituitary gland with ring-like enhancement and sphenoid sinus mucosa thickening. Transsphenoidal surgery was performed. Histologically CD68 positive macrophages were found supporting the diagnosis of infectious hypophysitis. Under hormone replacement therapy and retroviral treatment the patient clinically normalized. A pituitary abscess due to infectious hypophysitis is a rare cause of pituitary failure. Diagnostic signs on imaging may help to rapidly distinguish the cause of pituitary deficiency in patients with HIV infection.
    Experimental and Clinical Endocrinology & Diabetes 09/2011; 119(10):633-5. · 1.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Radiotherapy is a central component in the treatment of many brain tumors, but long-term sequelae include GH deficiency and increased risk of secondary neoplasms. It is unclear whether replacement therapy with GH (GHRT) further increases this risk. The objective of the study was to assess the effect of GHRT on the incidence of secondary tumors and tumor recurrence after cranial irradiation. We conducted a retrospective matched-pairs analysis of previously irradiated patients, with and without GHRT, attending a tertiary center between 1994 and 2009. Patients: We reviewed the records for all patients undergoing GHRT at our institution over the study period. Patients were included if they had received cranial irradiation, GHRT for at least 12 months, and records of serial magnetic resonance imaging data and data for dose and fractionation of irradiation were available. GH-naïve control patients were selected from a radiotherapy database of patients attending the same hospital. Patients were matched for date of radiotherapy, age, site of primary diagnosis, radiation dose, and fractionation. The primary outcome measure was risk of tumor recurrence or secondary tumor. Matched controls were identified for 110 GH-treated patients. Median follow-up was 14.5 yr. No significant differences were apparent in the number of tumor recurrences (six vs. eight, GHRT vs. control group) or secondary tumors (five vs. three, respectively) between groups. Our study demonstrates no increased risk for recurrent or secondary neoplasms in patients receiving GHRT, thus supporting a high safety profile of GHRT after central nervous system irradiation.
    The Journal of Clinical Endocrinology and Metabolism 06/2011; 96(9):2756-61. · 6.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hypopituitarism is not a rare disease and its clinical signs and symptoms deserve the attention of the clinically practising neurologist. Next to the classical cause of hypopituitarism mediated by tumours of the hypothalamo-pituitary region, a number of recent articles have highlighted the high frequency of central endocrine disturbances in patients with brain damage, i. e. not only after traumatic brain injury and subarachnoid haemorrhage but also as a consequence of the treatment of childhood brain tumours. This article provides an overview of the clinical symptomatology and pathophysiology of hypopituitarism as well as the current knowledge about neuroendocrine disturbances in the adult patient suffering from the above-mentioned disorders.
    Fortschritte der Neurologie · Psychiatrie 04/2011; 79(4):213-20. · 0.85 Impact Factor
  • Das Gesundheitswesen 09/2010; 72(08/09). · 0.62 Impact Factor
  • G. Brabant
    Der Onkologe 07/2010; 16(7):643-643. · 0.13 Impact Factor
  • G Brabant
    MMW Fortschritte der Medizin 04/2010; 152(13):37-9.
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 57 yr old man presented to endocrinology clinic with a six year history of poorly controlled hypertension which was treated with Metoprolol 200 mg/day and Enalapril 20 mg/day. He was asymptomatic but incidentally hypokalaemia was detected while having cholecystectomy, two years prior to his clinic appointment. He had never been on diuretics or laxatives. He was started on potassium supplements (120 mmol/d) and advised to increase dietary potassium by the surgical team. A detailed personal history revealed ingestion of 300-500 g licorice per day. Physical examination was unremarkable apart from increased blood pressure of 180/105 mmHg. Following the initial visit, his serum electrolyes (K+3.7 mmol/l) were normal with potassium supplementation and as were morning cortisol, ACTH, 11-deoxycortisol and plasma metanephrines. 17 OH-P, DHEAS and androstenedione were normal but testosterone was low. Morning ambulant aldosterone was slightly increased at 801 pmol/L and renin activity was undetectable. Urinary 24 h aldosterone excretion was significantly increased at 162 ng/24 h with normal cortisol and catecholamine excretion. Four weeks following advice to stop licorice, serum potassium decreased to 3.4 mmol/L despite continuous supplementation. Morning plasma aldosterone increased to 1 449 pmol/ml, renin activity remained undetectable but 24 h urine aldosterone excretion increased to 434 ng/24 h with a reduction in urinary cortisol excretion. Interestingly 17 OH-P and androstenedione levels, although within the reference range, were slightly higher compared to the levels whilst on licorice. Testosterone level had significantly increased to be within normal range. Abdominal imaging with US and MRI showed a 2.7 cmx2.2 cmx1.7 cm left adrenal mass. He underwent laparoscopic left adrenalectomy and histology confirmed aldosterone producing adrenal adenoma. Post-operatively his aldosterone and serum potassium levels normalized and he became normotensive without any antihypertensive medication.
    Experimental and Clinical Endocrinology & Diabetes 03/2010; 118(4):250-3. · 1.76 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The incidence of water and electrolyte disturbances following traumatic brain injury (TBI) is considerable and has been attributed to a dysregulation of the hypothalamic peptide arginine-vasopressin (AVP). Copeptin, the C-terminal part of the AVP prohormone, reflects AVP activity. In 71 TBI patients we measured copeptin in serum by a sandwich immunoassay. Injury severity was assessed by Glasgow Coma Score (GCS) and computed tomography, and recovery by Glasgow Outcome Score (GOS). Neuroendocrine and osmoregulation regulation were examined on day 0, 3 and 7, and 24 months post-injury. Copeptin was highest on admission (40.0 +/- 72.3 pmol/l), stabilized on day 3 and 7 (21.2 +/- 18.3 resp. 20.3 +/- 17.1 pmol/l), and normalized at follow-up (4.2 +/- 1.7 pmol/l). On admission, there was a correlation between serum sodium and urine excretion (p = 0.003), but the correlation got lost on day 3 and 7. Copeptin did not reflect the individual 24 h urine excretion or serum sodium levels indicating an uncoupling of copeptin/AVP release and renal water excretion. High copeptin level on day 3 were correlated with a low GCS (p < 0.001), midline shift (p = 0.019), intracerebral hemorrhage (p = 0.026), SAPS score (p = 0.001), as well as with a low GOS (p = 0.031). Copeptin was significantly decreased following skullbase fracture (p = 0.016).Our data reveal a loss of hypothalamic osmoregulation following TBI. The measurement of Copeptin/AVP release reveals a significant predictive function for the severity of TBI.
    Acta neurochirurgica. Supplement 01/2010; 106:221-4. · 1.79 Impact Factor

Publication Stats

4k Citations
899.03 Total Impact Points

Institutions

  • 2012–2013
    • Universitätsklinikum Schleswig - Holstein
      Kiel, Schleswig-Holstein, Germany
    • Universität zu Lübeck
      Lübeck Hansestadt, Schleswig-Holstein, Germany
  • 2011
    • Universitätsklinikum Erlangen
      • Department of Neurosurgery
      Erlangen, Bavaria, Germany
  • 2010
    • Friedrich-Alexander Universität Erlangen-Nürnberg
      Erlangen, Bavaria, Germany
  • 1984–2010
    • Hannover Medical School
      • • Department of Gastroenterology, Hepatology and Endocrinology
      • • Department of Nuclear Medicine
      Hannover, Lower Saxony, Germany
  • 2009
    • The University of Manchester
      • School of Pharmacy and Pharmaceutical Sciences
      Manchester, ENG, United Kingdom
    • University of Greifswald
      • Institute of Clinical Chemistry and Laboratory Medicine
      Greifswald, Mecklenburg-Vorpommern, Germany
  • 2008
    • RWTH Aachen University
      • Department of Neurosurgery
      Aachen, North Rhine-Westphalia, Germany
  • 2005
    • Bielefeld University
      • CeBiTec - Center for Biotechnology
      Bielefeld, North Rhine-Westphalia, Germany
    • University of Leipzig
      Leipzig, Saxony, Germany
  • 2004
    • Philipps University of Marburg
      Marburg, Hesse, Germany
    • Universität Ulm
      • Department of Internal Medicine
      Ulm, Baden-Wuerttemberg, Germany
  • 2001–2003
    • Hochschule Hannover
      Hanover, Lower Saxony, Germany
    • Charité Universitätsmedizin Berlin
      • Department of Gastroenterology, Infectiology and Rheumatology
      Berlin, Land Berlin, Germany
  • 1999
    • The University of Warwick
      • Biological Sciences
      Warwick, ENG, United Kingdom
  • 1998
    • Academy of Sciences of the Czech Republic
      • Ústav informatiky
      Praha, Hlavni mesto Praha, Czech Republic
  • 1996–1998
    • Private Institute for Endocrinology, Reproductive and Preventive Medicine Dr. Verhoeven
      Düsseldorf, North Rhine-Westphalia, Germany
    • Martin Luther University of Halle-Wittenberg
      Halle-on-the-Saale, Saxony-Anhalt, Germany
  • 1995
    • Kyoto University
      • Graduate School of Medicine / Faculty of Medicine
      Kioto, Kyōto, Japan
    • Salk Institute
      La Jolla, California, United States
  • 1990–1994
    • University of Amsterdam
      • • Department of Endocrinology
      • • Department of Intensive Care
      Amsterdamo, North Holland, Netherlands
  • 1991
    • Free University of Brussels
      • Institute of Interdisciplinary Research (IRIBHM)
      Brussels, BRU, Belgium