141 research outputs found
Hypothyroidism Enhances Tumor Invasiveness and Metastasis Development
11 pages, 9 figures.[Background]: Whereas there is increasing evidence that loss of expression and/or function of the thyroid hormone receptors (TRs) could result in a selective advantage for tumor development, the relationship between thyroid hormone levels and human cancer is a controversial issue. It has been reported that hypothyroidism might be a possible risk factor for liver and breast cancer in humans, but a lower incidence of breast carcinoma has been also reported in hypothyroid patients
[Methodology/Principal Findings]: In this work we have analyzed the influence of hypothyroidism on tumor progression and metastasis development using xenografts of parental and TRβ1–expressing human hepatocarcinoma (SK-hep1) and breast cancer cells (MDA-MB-468). In agreement with our previous observations tumor invasiveness and metastasis formation was strongly repressed when TRβ–expressing cells were injected into euthyroid nude mice. Whereas tumor growth was retarded when cells were inoculated into hypothyroid hosts, tumors had a more mesenchymal phenotype, were more invasive and metastatic growth was enhanced. Increased aggressiveness and tumor growth retardation was also observed with parental cells that do not express TRs.
[Conclusions/Significance]: These results show that changes in the stromal cells secondary to host hypothyroidism can modulate tumor progression and metastatic growth independently of the presence of TRs on the tumor cells. On the other hand, the finding that hypothyroidism can affect differentially tumor growth and invasiveness can contribute to the explanation of the confounding reports on the influence of thyroidal status in human cancer.This work was supported by grants BFU2007-62402 from MEC; RD06/0020/0036 from FIS and from the EU Project CRESCENDO (FP6-018652.Peer reviewe
Local hyperthyroidism promotes pancreatic acinar cell proliferation during acute pancreatitis
Proliferation of pancreatic acinar cells is a critical process in the pathophysiology of pancreatic diseases, because limited or defective proliferation is associated with organ dysfunction and patient morbidity. In this context, elucidating the signalling pathways that trigger and sustain acinar proliferation is pivotal to develop therapeutic interventions promoting the regenerative process of the organ.In this study we used genetic and pharmacological approaches to manipulate both local and systemic levels of thyroid hormones to elucidate their role in acinar proliferation following caerulein‐mediated acute pancreatitis in mice. In addition, molecular mechanisms mediating the effects of thyroid hormones were identified by genetic and pharmacological inactivation of selected signalling pathways.In this study we demonstrated that levels of the thyroid hormone 3,3’,5‐triodo‐L‐thyronine (T3) transiently increased in the pancreas during acute pancreatitis. Moreover, by using genetic and pharmacological approaches to manipulate both local and systemic levels of thyroid hormones, we showed that T3 was required to promote proliferation of pancreatic acinar cells, without affecting the extent of tissue damage or inflammatory infiltration.Finally, upon genetic and pharmacological inactivation of selected signalling pathways, we demonstrated that T3 exerted its mitogenic effect on acinar cells via a tightly controlled action on different molecular effectors, including histone deacetylase, AKT, and TGFβ signalling.In conclusion, our data suggest that local availability of T3 in the pancreas is required to promote acinar cell proliferation and provide the rationale to exploit thyroid hormone signalling to enhance pancreatic regeneration
State of the Art Review: Emerging Therapies: The Use of Insulin Sensitizers in the Treatment of Adolescents with Polycystic Ovary Syndrome (PCOS)
PCOS, a heterogeneous disorder characterized by cystic ovarian morphology, androgen excess, and/or irregular periods, emerges during or shortly after puberty. Peri- and post-pubertal obesity, insulin resistance and consequent hyperinsulinemia are highly prevalent co-morbidities of PCOS and promote an ongoing state of excess androgen. Given the relationship of insulin to androgen excess, reduction of insulin secretion and/or improvement of its action at target tissues offer the possibility of improving the physical stigmata of androgen excess by correction of the reproductive dysfunction and preventing metabolic derangements from becoming entrenched. While lifestyle changes that concentrate on behavioral, dietary and exercise regimens should be considered as first line therapy for weight reduction and normalization of insulin levels in adolescents with PCOS, several therapeutic options are available and in wide use, including oral contraceptives, metformin, thiazolidenediones and spironolactone. Overwhelmingly, the data on the safety and efficacy of these medications derive from the adult PCOS literature. Despite the paucity of randomized control trials to adequately evaluate these modalities in adolescents, their use, particularly that of metformin, has gained popularity in the pediatric endocrine community. In this article, we present an overview of the use of insulin sensitizing medications in PCOS and review both the adult and (where available) adolescent literature, focusing specifically on the use of metformin in both mono- and combination therapy
ATHENA detector proposal - a totally hermetic electron nucleus apparatus proposed for IP6 at the Electron-Ion Collider
ATHENA has been designed as a general purpose detector capable of delivering the full scientific scope of the Electron-Ion Collider. Careful technology choices provide fine tracking and momentum resolution, high performance electromagnetic and hadronic calorimetry, hadron identification over a wide kinematic range, and near-complete hermeticity.This article describes the detector design and its expected performance in the most relevant physics channels. It includes an evaluation of detector technology choices, the technical challenges to realizing the detector and the R&D required to meet those challenges
Angiotensin-converting enzyme (ACE) haplotypes and cyclosporine A (CsA) response: a model of the complex relationship between ACE quantitative trait locus and pathological phenotypes
none9noneCATARSI P; RAVAZZO R; EMMA F; FRUCI D; L. FINOS; FRAU A; MORREALE G; CARREA A; GHIGGERI GMCatarsi, P; Ravazzo, R; Emma, F; Fruci, D; Finos, Livio; Frau, A; Morreale, G; Carrea, A; Ghiggeri, G
Structural brain MR imaging changes associated with obsessive-compulsive disorder in patients with multiple sclerosis.
BACKGROUND AND PURPOSE:
Psychiatric symptoms occur in approximately 30% of patients with MS. Such symptoms include OCD, which may interfere heavily with the patient's daily life. We hypothesized that the widespread involvement of both GM and WM, which characterizes MS, may be responsible for the occurrence of OCD when specific brain structures are affected. The aim of this study was to evaluate the relationship between GM and WM tissue damage and OCD in patients with MS.
MATERIALS AND METHODS:
We evaluated 16 patients with relapsing-remitting MS who had been diagnosed with OCD on the basis of the Diagnostic and Statistical Manual of Mental Disorders (4th edition) and 15 age- and sex-matched patients with relapsing-remitting MS with no psychiatric disorders as a CG. The MR study (1.5T) included 3D T1-weighted fast-field echo sequences, DTI (32 directions), and conventional MRI. Images were processed using SPM5, FSL, and Jim 5.0 software to evaluate VBM, TBSS, and global and regional LV, respectively.
RESULTS:
The VBM analysis revealed a set of clusters of reduced GM volume in the OCD group, compared with the CG, located in the right inferior and middle temporal gyri and in the inferior frontal gyrus. TBSS did not detect any differences in the FA values between the 2 groups; global and regional LV values also did not differ significantly between the 2 groups.
CONCLUSIONS:
Our study suggests that OCD in MS may be caused by damage in the right frontotemporal cortex
- …