The hypothalamus–pituitary–thyroid feedback control is a dynamic, adaptive system. In situations of illness and deprivation of energy representing type 1 allostasis, the stress response operates to alter both its set point and peripheral transfer parameters. In contrast, type 2 allostatic load, typically effective in psychosocial stress, pregnancy, metabolic syndrome, and adaptation to cold, produces a nearly opposite phenotype of predictive plasticity. The non-thyroidal illness syndrome (NTIS) or thyroid allostasis in critical illness, tumors, uremia, and starvation (TACITUS), commonly observed in hospitalized patients, displays a historically well-studied pattern of allostatic thyroid response. This is characterized by decreased total and free thyroid hormone concentrations and varying levels of thyroid-stimulating hormone (TSH) ranging from decreased (in severe cases) to normal or even elevated (mainly in the recovery phase) TSH concentrations. An acute versus chronic stage (wasting syndrome) of TACITUS can be discerned. The two types differ in molecular mechanisms and prognosis. The acute adaptation of thyroid hormone metabolism to critical illness may prove beneficial to the organism, whereas the far more complex molecular alterations associated with chronic illness frequently lead to allostatic overload. The latter is associated with poor outcome, independently of the underlying disease. Adaptive responses of thyroid homeostasis extend to alterations in thyroid hormone concentrations during fetal life, periods of weight gain or loss, thermoregulation, physical exercise, and psychiatric diseases. The various forms of thyroid allostasis pose serious problems in differential diagnosis of thyroid disease. This review article provides an overview of physiological mechanisms as well as major diagnostic and therapeutic implications of thyroid allostasis under a variety of developmental and straining conditions.
Introduction In critically ill patients, the appearance of nucleated red blood cells (NRBCs) in blood is associated with a variety of severe diseases. Generally, when NRBCs are detected in the patients' blood, the prognosis is poor.
Transforming growth factor beta is one of the most abundant growth factors stored in bone. It is known as a potent regulator of osteoblast proliferation and differentiation as well as of production extracellular matrix. We established a highly specific RT-PCR in combination with HPLC for detection and quantification of TGFbeta1 and TGFbeta2 mRNA expression in 89 human bone samples. Levels of TGFbeta1 protein ranged between 27 and 580 ng/g bone (mean 188 +/- 15 ng/g; n=75) and for TGFbeta2 between 7.2 and 35 ng/g bone (mean 14.3 +/- 2.1 ng/g; n=57). TGFbeta1 and TGFbeta2 protein concentrations and TGFbeta isoform mRNA expression in bone were not significantly different between the sexes. TGFbeta isoform mRNA expression as well as protein content in bone declined age dependently. TGFbeta1 and TGFbeta2 protein and mRNA expression were different in bone samples from different sites of the skeleton indicating in part the regulation by mechanical stimuli. In contrast to TGFbeta1, TGFbeta2 mRNA expression was significantly enhanced in osteoarthritic bone compared to unaffected bone. These data are in concordance to previous results concerning the expression of TGFbeta3 in bone. In conclusion, the data suggest distinct patterns' of expression of the TGFbeta isoforms under physiological and pathological conditions in bone.
BackgroundNon-thyroidal illness syndrome (NTIS) is a characteristic functional constellation of thyrotropic feedback control that frequently occurs in critically ill patients. Although this condition is associated with significantly increased morbidity and mortality, there is still controversy on whether NTIS is caused by artefacts, is a form of beneficial adaptation, or is a disorder requiring treatment. Trials investigating substitution therapy of NTIS revealed contradictory results. The comparison of heterogeneous patient cohorts may be the cause for those inconsistencies.ObjectivesPrimary objective of this study is the identification and differentiation of different functional states of thyrotropic feedback control in order to define relevant evaluation criteria for the prognosis of affected patients. Furthermore, we intend to assess the significance of an innovative physiological index approach (SPINA) in differential diagnosis between NTIS and latent (so-called "sub-clinical") thyrotoxicosis.Secondary objective is observation of variables that quantify distinct components of NTIS in the context of independent predictors of evolution, survival or pathophysiological condition and influencing or disturbing factors like medication.DesignThe approach to a quantitative follow-up of non-thyroidal illness syndrome (AQUA FONTIS study) is designed as both a cross-sectional and prospective longitudinal observation trial in critically ill patients. Patients are observed in at least two evaluation points with consecutive assessments of thyroid status, physiological and clinical data in additional weekly observations up to discharge. A second part of the study investigates the neuropsychological impact of NTIS and medium-term outcomes.The study design incorporates a two-module structure that covers a reduced protocol in form of an observation trial before patients give informed consent. Additional investigations are performed if and after patients agree in participation.Trial RegistrationClinicalTrials.gov NCT00591032
We show that a general risk score for medical intensive care patients on admission based solely on routine laboratory parameters is feasible. The quality of risk estimation using CREEK is comparable to established risk models. Furthermore, this new score is based on quality controlled low-cost laboratory parameters that are routinely measured on admission to the intensive care unit. Therefore, no additional costs are involved.
Germany). Abnormal thyroid function is common in takotsubo syndrome and depends on two distinct mechanisms: results of a multicentre observational study.
BackgroundIpilimumab is a cytotoxic T-lymphocyte-associated protein 4 receptor antibody used for immunotherapy in cancer. Several immune-related adverse events are known. Steroid responsive encephalopathy associated with autoimmune thyroiditis is an autoimmune encephalopathy associated with Hashimoto’s Disease and elevated serum levels of the related antibodies (anti-thyroid-peroxidase antibody or anti-thyroglobulin antibody). Our case implies that steroid responsive encephalopathy associated with autoimmune thyroiditis may be another previously unreported side effect of ipilimumab therapy.Case presentationWe report the case of a 64 years old caucasian patient with prostatic cancer who received ipilimumab therapy in a clinical trial. He presented with aphasia, tremor and ataxia, myocloni, hallucinations, anxiety and agitation in turns with somnolence. Cranial nerves, deep tendon reflexes, motor and sensory functions were normal. Electroencephalography showed background slowing but no epileptic discharges. Brain magnetic resonance imaging was normal and showed no signs of hypophysitis. Cerebrospinal fluid findings ruled out infection and neoplastic meningitis. Anti-thyroid antibodies (anti-thyroid-peroxidase antibody and anti-thyroglobulin antibody) were heavily increased. Assuming steroid responsive encephalopathy associated with autoimmune thyroiditis the patient was treated with 1,000 mg methylprednisolone i.v. for 3 days and continued with 1 mg/kg orally. On the 3rd day of treatment the patient’s condition started to improve. Within the next few days he gradually returned to his previous state, and electroencephalography eventually showed only slight slowing. Seven months later the patient’s condition was stable, and anti-thyroid antibodies were no more detectable.ConclusionSteroid responsive encephalopathy associated with autoimmune thyroiditis may be a hitherto unrecognized complication of ipililumab treatment and should be taken into consideration in patients developing central nervous symptoms undergoing this treatment.
Recent data indicate that TGFbeta3, one member of the TGFbeta-isoforms, has an important role in bone remodeling. Up to date little is known about the expression and regulation of TGFbeta3 in man. We established a highly specific ELISA for quantitative measurement of TGFbeta3 in bone and blood samples and a RT-PCR in combination with HPLC for detection and quantification of TGFbeta3 mRNA in 89 human bone samples. Levels of TGFbeta3 protein ranged between 30 and 66 pg/mg bone (mean 36,6 +/-1,03 pg/mg) and between 30 and 1910 pg/ml in serum (mean 128.9+/-38.9 pg/ml). TGFbeta3 mRNA expression as well as protein levels in serum and in bone declined age dependently. No specific load- or site-specific distribution of TGFbeta3 mRNA expression or protein content was detected at different sites indicating an absence of mechanical regulation. Protein levels of TGFbeta3 in serum correlated with TGFbeta3 mRNA expression in bone (p= 0.0027; r=0.49). By contrast, TGFbeta3 protein levels stored in the bone matrix were not related to TGFbeta3 mRNA reflecting the long term process of TGFbeta3 deposition during bone remodeling. Notably TGFbeta3 serum levels were highly correlated with IGF-I and osteocalcin levels in serum. We conclude that TGFbeta3 in man circulates in significant amounts which appears to be representative for TGFbeta3 expression in bone tissue and may be in part derived from bone. The high correlation of TGFbeta3 with IGF-I suggests parallel systemic principles of regulation.
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