Publications by authors named "Helena Kerp"

Article Synopsis
  • Thyroid hormones (THs) are important for heart health, but their effects on older mice with existing heart issues remain unclear, especially in the context of conditions like hypertension and aging.
  • A study found that manipulating TH levels in aged mice with heart damage (induced by transverse aortic constriction) showed minimal effects on heart function and structure, contrasting with significant changes seen in younger mice.
  • The researchers noted altered expressions of certain genes related to TH metabolism and action in older mice, which might explain the reduced responsiveness of their hearts to thyroid hormone levels.
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Background: Treatment of Epstein-Barr virus(EBV)-positive nasopharyngeal carcinoma (NPC) with cisplatin/5-fluorouracil (5-FU) induction chemotherapy, followed by radiochemotherapy and subsequent interferon‑β, has yielded high survival rates in children, adolescents, and young adults. A previous study has shown that reduction of radiation dose from 59.4 to 54.

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Hypothyroidism has been shown to reduce infarct size in rats, but the underlying mechanisms are unclear. We used isolated pressure-constant perfused hearts of control, hypothyroid and hyperthyroid mice and measured infarct size, functional parameters and phosphorylation of key molecules in cardioprotective signaling with matched heart rate. Compared with controls, hypothyroidism was cardioprotective, while hyperthyroidism was detrimental with enlarged infarct size.

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Article Synopsis
  • In animal studies, the thyroid hormone (TH) axis is often only evaluated by measuring circulating thyroid hormones (THs) and thyroid-stimulating hormone (TSH), without considering local mechanisms that influence TH effects.
  • Recent assays using the Sandell-Kolthoff reaction can evaluate the impact of chemicals on specific enzyme activities related to TH metabolism and also measure iodine levels in various biological samples.
  • This study measured deiodinase type 1 and iodotyrosine dehalogenase activities in both young and old hypo- and hyperthyroid mice, revealing organ-specific regulation which could inform future research and help develop a more integrated approach to testing and assessment of the TH system.
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Context: 3,5,3'-L-triiodothyronine (T3) is a potent inducer of hepatocyte proliferation via the Wnt/β-catenin signaling pathway. Previous studies suggested the involvement of rapid noncanonical thyroid hormone receptor (TR) β signaling, directly activating hepatic Wnt/β-catenin signaling independent from TRβ DNA binding. However, the mechanism by which T3 increases Wnt/β-catenin signaling in hepatocytes has not yet been determined.

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Thyroid hormones (TH) play a central role for cardiac function. TH influence heart rate and cardiac contractility, and altered thyroid function is associated with increased cardiovascular morbidity and mortality. The precise role of TH in onset and progression of heart failure still requires clarification.

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Thyroid hormone (TH) metabolism and cellular TH action are influenced by ageing. To investigate the response to thyroxine (T4) overtreatment, a kinetic study was conducted in young and aged mice with chronic hyperthyroidism and hormone withdrawal. Five and 22 months old male mice were treated with T4 or PBS over 5 weeks, followed by observation for up to 12 days.

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Context: Hypothyroidism impairs cardiovascular health and contributes to endothelial dysfunction with reduced vasodilation. How 3,5,3'-triiodothyronine (T3) and its receptors are involved in the regulation of vasomotion is not yet fully understood. In general, thyroid hormone receptors (TRs) either influence gene expression (canonical action) or rapidly activate intracellular signaling pathways (noncanonical action).

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Age and sex impact prevalence and clinical features of thyroid disease. Thyroid dysfunction occurs with a higher frequency in elderly patients and females. Moreover, age alters clinical presentation of hyper- and hypothyroidism and onset of thyroid hormone (TH) related co-morbidities leading to increased risk for underdiagnosis and maltreatment in the elderly.

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The aim of this study was to investigate in a longitudinal approach whether levothyroxine (LT4) substitution has a different impact on quality of life (QoL) and thyroid related QoL in younger (<40 years) and older subjects (>60 years) with elevated thyroid-stimulating hormone (TSH) concentrations. The study included male and female patients with newly diagnosed, untreated subclinical hypothyroidism defined by TSH>8 mU/l. Patients were recruited throughout Germany from 2013-2016 and evaluated by clinical assessment, blood sampling and questionnaires for health related QoL and thyroid-disease thyroid-related QoL (ThyPRO) at time of diagnosis and six months after initiation of LT4 treatment.

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Purpose: Thyroid hormones (TH) are important for brain development and central nervous system (CNS) function. Disturbances of thyroid function occur with higher prevalence in the ageing population and may negatively impact brain function.

Methods: We investigated the age impact on behavior in young adult and old male mice (5 vs.

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