44 research outputs found

    An updated view of hypothalamic-vascular-pituitary unit function and plasticity

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    The discoveries of novel functional adaptations of the hypothalamus and anterior pituitary gland for physiological regulation have transformed our understanding of their interaction. The activity of a small proportion of hypothalamic neurons can control complex hormonal signalling, which is disconnected from a simple stimulus and the subsequent hormone secretion relationship and is dependent on physiological status. The interrelationship of the terminals of hypothalamic neurons and pituitary cells with the vasculature has an important role in determining the pattern of neurohormone exposure. Cells in the pituitary gland form networks with distinct organizational motifs that are related to the duration and pattern of output, and modifications of these networks occur in different physiological states, can persist after cessation of demand and result in enhanced function. Consequently, the hypothalamus and pituitary can no longer be considered as having a simple stratified relationship: with the vasculature they form a tripartite system, which must function in concert for appropriate hypothalamic regulation of physiological processes, such as reproduction. An improved understanding of the mechanisms underlying these regulatory features has implications for current and future therapies that correct defects in hypothalamic–pituitary axes. In addition, recapitulating proper network organization will be an important challenge for regenerative stem cell treatment

    Recurrent desmoids determine outcome in patients with Gardner syndrome: a cohort study of three generations of an APC mutation-positive family across 30 years

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    PURPOSE: Screening of Gardner syndrome (GS) patients is tailored towards prevention of colorectal cancer (CRC). However, many patients suffer from desmoid tumors, which are challenging to treat due to invasive growth and local recurrence. The aims of our study were to determine the effectiveness of screening in GS and analyze outcome of desmoid tumors by treatment modality. METHODS: This was a cohort study of a family of 105 descendants with GS. All family members who agreed were screened by endoscopy, and colorectal resection was performed upon pending malignancy. Resectable desmoids were excised, whereas large tumors were treated by a combination of brachytherapy (BT) and radiotherapy (RT). Main outcome measures were the incidence of CRC and overall and disease-specific mortality (ClinicalTrial.gov ID NCT01286662). RESULTS: Thirty-seven of 105 family members have GS. Preventive colorectal resections were performed in 16 patients (15 %), with one death due to gastric cancer. In four patients who denied screening endoscopy, invasive tumors of the colon (three patients) and stomach developed. Of 33 desmoid tumors, 10 (30 %) were located in the mesentery, 17 (52 %) in the abdominal wall, and 6 (18 %) in extra-abdominal sites. Excision of 12 desmoids was performed in eight patients. Four desmoids were treated by BT and RT and showed full or partial remission. CONCLUSIONS: Provided adequate screening, good long-term control of colorectal tumors is achievable. However, desmoid tumors determine survival and quality of life in many patients. Our data suggest good local control using a combination of brachytherapy/radiotherapy in large desmoids unsuitable for surgical resection
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