Hyponatremia, hypernatremia and impairment of functional, psychological and sexual domains

OBJECTIVE

To determine the influence of serum sodium on physical, psychologic and sexual function.

METHODS

This is a cross-sectional survey on 3340 community-dwelling men aged 40-79 years from a prospective cohort study in eight European countries, the European Male Ageing Study (EMAS). Participants filled-out the Short Form-36 (SF-36), the Physical Activity Scale for the Elderly (PASE), and the EMAS sexual function questionnaire. For all the analyses, serum sodium corrected for glycaemia ([Na+]G) was used.

RESULTS

The relationship between [Na+]G and SF-36 physical function score (F = 3.99; p = 0.01), SF-36 mental health score (F = 7.69; p < 0.001), and PASE score (F = 14.95; p < 0.001) were best described by a quadratic equation, with worse scores for [Na+]G in either the lowest or the highest ends of the range. After dividing the sample into [Na+]G < 136 mmol/L (n = 81), 136-147 mmol/L (n = 3223) and > 147 mmol/L (n = 36), linear regression analyses with linear spline functions adjusted for confounders did not confirm these relationships. Similarly, erectile dysfunction and [Na+]G, were in a quadratic relationship (F = 9.00; p < 0.001). After adjusting for confounders, the linear regression with spline functions denoted a significantly worsened erectile function for increases in serum [Na+]G > 147 mmol/L (B = 0.15 [0.04;0.26], p < 0.01) but no relationship with [Na+]G < 136 mmol/L. Likewise, the relationship of [Na+]G with concerns about sexual dysfunction was confirmed only for men with serum [Na+]G > 147 mmol/L.

CONCLUSIONS

This is the first study supporting an association between [Na+]G and sexual function. A worsening of erection and concerns about sexual function were observed for the highest values of [Na+]G, independently of other relevant factors.

Disease control of acromegaly does not prevent excess mortality in the long term: results of a nationwide survey in Italy

OBJECTIVE

This study aimed to assess the long-term outcome of patients with acromegaly.

DESIGN

This is a multicenter, retrospective, observational study which extends the mean observation period of a previously reported cohort of Italian patients with acromegaly to 15 years of follow-up.

METHODS

Only patients from the centers that provided information on the life status of at least 95% of their original cohorts were included. Life status information was collected either from clinical records or from the municipal registry offices. Standardized mortality ratios (SMRs) were computed comparing data with those of the general Italian population.

RESULTS

A total of 811 patients were included. There were 153 deaths, with 90 expected and an SMR of 1.7 (95% CI 1.4-2.0, p < 0.001). Death occurred after a median of 15 (women) or 16 (men) years from the diagnosis, without gender differences. Mortality remained elevated in the patients with control of disease (SMR 1.3, 95% CI 1.1-1.6). In the multivariable analysis, only older age and high IGF1 concentrations at last available follow-up visit were predictors of mortality. The oncological causes of death outweighed the cardiovascular ones, bordering on statistical significance with respect to the general population.

CONCLUSIONS

Mortality remains significantly high in patients with acromegaly, irrespectively of disease status, as long as the follow-up is sufficiently long with a low rate of patients lost to follow-up. Therapy strategy including radiotherapy does not have an impact on mortality. Oncological causes of death currently outweigh the cardiovascular causes.

The landscape of T cell antigens for cancer immunotherapy

The remarkable capacity of immunotherapies to induce durable regression in some patients with metastatic cancer relies heavily on T cell recognition of tumor-presented antigens. As checkpoint-blockade therapy has limited efficacy, tumor antigens have the potential to be exploited for complementary treatments, many of which are already in clinical trials. The surge of interest in this topic has led to the expansion of the tumor antigen landscape with the emergence of new antigen categories. Nonetheless, how different antigens compare in their ability to elicit efficient and safe clinical responses remains largely unknown. Here, we review known cancer peptide antigens, their attributes and the relevant clinical data and discuss future directions.

Hyponatremia-related liver steatofibrosis and impaired spermatogenesis: evidence from a mouse model of the syndrome of inappropriate antidiuresis

PURPOSE

Hyponatremia is the most frequent electrolytic disorder in clinical practice. In addition to neurological symptoms, hyponatremia, even when mild/moderate and chronic, has been related to other manifestations, such as bone demineralization and increased risk of fractures. To better elucidate tissue alterations associated with reduced serum sodium concentration [Na⁺], we developed an in vivo model of hyponatremia secondary to the Syndrome of Inappropriate Antidiuresis.

METHODS AND RESULTS

Hyponatremia was induced in Foxn1^nu/nu mice by subcutaneous infusion of the vasopressin analog 1-deamino [8-D-arginine] vasopressin (dDAVP) for 14 days via osmotic mini-pumps. Mice in the control group were infused with isotonic saline solution. Serum [Na⁺] progressively decreased, with a nadir of 123.4 ± 2.3 mEq/L (mean ± SD, dDAVP 0.3 ng/h) and 111.6 ± 4.7 mEq/L (mean ± SD, dDAVP 0.5 ng/h). Evident signs of liver steatofibrosis were observed at histology in hyponatremic mice. Accordingly, the expression of proteins involved in lipid metabolism (SREBP-1, PPARα and PPARγ) and in myofibroblast formation (αSMA and CTGF) significantly increased. Furthermore, heme oxygenase 1 expression was up-regulated in Kupffer and hepatic stellate cells in the liver of hyponatremic mice. Testis alterations were also observed. In particular, the thickness of the seminiferous epithelium appeared reduced. The expression levels of PCNA and PTMA, which are involved in DNA replication and germ cells maturation, were markedly reduced in the testis of hyponatremic mice.

CONCLUSION

Overall, these findings shed new light on the possible consequences of chronic hyponatremia and prompt a more thorough evaluation of hyponatremic patients.

Relationship between hyponatremia at hospital admission and cardiopulmonary profile at follow-up in patients with SARS-CoV-2 (COVID-19) infection

PURPOSE

Hyponatremia occurs in about 30% of patients with pneumonia, including those with SARS-CoV-2 (COVID-19) infection. Hyponatremia predicts a worse outcome in several pathologic conditions and in COVID-19 has been associated with a higher risk of non-invasive ventilation, ICU transfer and death. The main objective of this study was to determine whether early hyponatremia is also a predictor of long-term sequelae at follow-up.

METHODS

In this observational study, we collected 6-month follow-up data from 189 laboratory-confirmed COVID-19 patients previously admitted to a University Hospital. About 25% of the patients (n = 47) had hyponatremia at the time of hospital admission.

RESULTS

Serum [Na⁺] was significantly increased in the whole group of 189 patients at 6 months, compared to the value at hospital admission (141.4 ± 2.2 vs 137 ± 3.5 mEq/L, p < 0.001). In addition, IL-6 levels decreased and the PaO₂/FiO₂ increased. Accordingly, pulmonary involvement, evaluated at the chest X-ray by the RALE score, decreased. However, in patients with hyponatremia at hospital admission, higher levels of LDH, fibrinogen, troponin T and NT-ProBNP were detected at follow-up, compared to patients with normonatremia at admission. In addition, hyponatremia at admission was associated with worse echocardiography parameters related to right ventricular function, together with a higher RALE score.

CONCLUSION

These results suggest that early hyponatremia in COVID-19 patients is associated with the presence of laboratory and imaging parameters indicating a greater pulmonary and right-sided heart involvement at follow-up.

The V2 receptor antagonist tolvaptan counteracts proliferation and invasivity in human cancer cells

PURPOSE

Hyponatremia, the most frequent electrolyte alteration in clinical practice, has been associated with a worse prognosis in cancer patients. On the other hand, a better outcome has been related to serum sodium normalization. In vitro studies have shown that low extracellular sodium promotes cancer cells proliferation and invasiveness. Tolvaptan, a selective vasopressin receptor type 2 (V₂) antagonist, has been effectively used in the last decade for the treatment of hyponatremia secondary to the Syndrome of Inappropriate Antidiuresis. A few in vitro data suggested a direct role of tolvaptan in counteracting cancer progression, so far. The aim of this study was to evaluate the effect and the mechanism of action of tolvaptan in cell lines from different tumours [i.e. colon cancer (HCT-8), hepatocarcinoma (HepG2), neuroblastoma (SK-N-AS)].

METHODS AND RESULTS

First, we showed that these cell lines express the V₂ receptor. Tolvaptan significantly reduced cell proliferation with an IC₅₀ in the micromolar range. Accordingly, reduced levels of cAMP, of the catalytic α subunit of PKA, and a reduced pAKT/AKT ratio were observed. Tolvaptan effectively inhibited cell cycle progression, whereas it induced apoptotis. Furthermore, it reduced cell invasiveness. In particular, anchorage-independent growth and the activity of collagenases type IV were blunted in the three cell lines. Accordingly, tolvaptan counteracted the RhoA/ROCK1-2 pathway, which has a pivotal role in regulating cell movement.

CONCLUSIONS

Overall, these findings indicate that tolvaptan effectively inhibits tumour progression in vitro. Further studies should clarify whether the V₂ receptor might be considered a possible target in anti-cancer strategies in the future.

Combined presentation and immunogenicity analysis reveals a recurrent RAS.Q61K neoantigen in melanoma

Neoantigens are now recognized drivers of the antitumor immune response. Recurrent neoantigens, shared among groups of patients, have thus become increasingly coveted therapeutic targets. Here, we report on the data-driven identification of a robustly presented, immunogenic neoantigen that is derived from the combination of HLA-A*01:01 and RAS.Q61K. Analysis of large patient cohorts indicated that this combination applies to 3% of patients with melanoma. Using HLA peptidomics, we were able to demonstrate robust endogenous presentation of the neoantigen in 10 tumor samples. We detected specific reactivity to the mutated peptide within tumor-infiltrating lymphocytes (TILs) from 2 unrelated patients, thus confirming its natural immunogenicity. We further investigated the neoantigen-specific clones and their T cell receptors (TCRs) via a combination of TCR sequencing, TCR overexpression, functional assays, and single-cell transcriptomics. Our analysis revealed a diverse repertoire of neoantigen-specific clones with both intra- and interpatient TCR similarities. Moreover, 1 dominant clone proved to cross-react with the highly prevalent RAS.Q61R variant. Transcriptome analysis revealed a high association of TCR clones with specific T cell phenotypes in response to cognate melanoma, with neoantigen-specific cells showing an activated and dysfunctional phenotype. Identification of recurrent neoantigens and their reactive TCRs can promote "off-the-shelf" precision immunotherapies, alleviating limitations of personalized treatments.

Identification of presented SARS-CoV-2 HLA class I and HLA class II peptides using HLA peptidomics

The human leukocyte antigen (HLA)-bound viral antigens serve as an immunological signature that can be selectively recognized by T cells. As viruses evolve by acquiring mutations, it is essential to identify a range of presented viral antigens. Using HLA peptidomics, we are able to identify severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-derived peptides presented by highly prevalent HLA class I (HLA-I) molecules by using infected cells as well as overexpression of SARS-CoV-2 genes. We find 26 HLA-I peptides and 36 HLA class II (HLA-II) peptides. Among the identified peptides, some are shared between different cells and some are derived from out-of-frame open reading frames (ORFs). Seven of these peptides were previously shown to be immunogenic, and we identify two additional immunoreactive peptides by using HLA multimer staining. These results may aid the development of the next generation of SARS-CoV-2 vaccines based on presented viral-specific antigens that span several of the viral genes.

Identification of bacteria-derived HLA-bound peptides in melanoma

A variety of species of bacteria are known to colonize human tumours1-11, proliferate within them and modulate immune function, which ultimately affects the survival of patients with cancer and their responses to treatment12-14. However, it is not known whether antigens derived from intracellular bacteria are presented by the human leukocyte antigen class I and II (HLA-I and HLA-II, respectively) molecules of tumour cells, or whether such antigens elicit a tumour-infiltrating T cell immune response. Here we used 16S rRNA gene sequencing and HLA peptidomics to identify a peptide repertoire derived from intracellular bacteria that was presented on HLA-I and HLA-II molecules in melanoma tumours. Our analysis of 17 melanoma metastases (derived from 9 patients) revealed 248 and 35 unique HLA-I and HLA-II peptides, respectively, that were derived from 41 species of bacteria. We identified recurrent bacterial peptides in tumours from different patients, as well as in different tumours from the same patient. Our study reveals that peptides derived from intracellular bacteria can be presented by tumour cells and elicit immune reactivity, and thus provides insight into a mechanism by which bacteria influence activation of the immune system and responses to therapy.

Quality of life and psychopathology in candidates to bariatric surgery: relationship with BMI class

PURPOSE

This cross-sectional study aimed at comparing the quality of life (Qol), the prevalence of psychiatric diagnosis and pharmacological treatment in 104 candidates to bariatric surgery according to the degree of obesity (class 2 vs. class ≥ 3 obesity).

METHODS

All surgical candidates underwent a detailed psychiatric interview based on DSM-5 criteria, including sociodemographic, clinical, psychological and psychiatric data. Participants completed the Binge Eating Scale (BES) and the 12-Item Short Form Health Survey (SF-12).

RESULTS

Overall, bariatric candidates reported a significant impairment in the physical (PCS 38.8 [95% CI 36.2-41.5]) and mental (MCS 42.2 [95% CI 40.4-43.9]) components of Qol compared to population norms (p < 0.001 for both). Subjects with class 2 obesity scored significantly lower in the MCS compared to those with class 3 (38.7 (8.1) vs. 43.6 (8.4), p = 0.008). No other statistically significant differences were found between the two groups in terms of sociodemographic and clinical variables.

CONCLUSION

These data support the usefulness of Qol assessment in bariatric candidates as a sensible screening parameter, especially in patients with lower BMI, in whom MCS could identify the need for early psychosocial intervention.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

Oral microbiome and mucosal trauma as risk factors for oral cancer: beyond alcohol and tobacco. A literature review

Oral and oropharyngeal cancer represents the sixth more common type of cancer affecting the worldwide population. It has been estimated the number of 650,000 new cases per year globally and a greater prevalence has been registered among men. The main risk factors for oral cancer such as tobacco smoking and alcohol are uncontroversial and have been deeply investigated and evidenced in the scientific literature. Recently, viral infections related to Human Papilloma Virus (HPV), with the genotype 16 and 32, have shown a correlation mainly with oropharyngeal cancer (OPC) especially in the non-smoking and non-drinkers young adults. Its transmission is mainly related to sexually transmitted diseases (STDs) although its involvement in oral squamous cell carcinoma (OSCC) is still unclear. This review aims to explore the hypotheses of the OSCC etiology and other possible risk factors, such as chronic traumatisms, chronic periodontitis, and poor oral hygiene that affect directly the oral mucosa and might trigger the carcinogenesis process that should not be underestimated. Furthermore, in the last 10 years, the role of oral microbiome gained attention as a predicting biomarker, for a possible bacterial, viral, and fungal involvement in tumorigenesis.

A unique neuroendocrine cell model derived from the human foetal neural crest

PURPOSE

Nowadays, no human neuroendocrine cell models derived from the neural crest are available. In this study, we present non-transformed long-term primary Neural Crest Cells (NCCs) isolated from the trunk region of the neural crest at VIII-XII gestational weeks of human foetuses obtained from voluntary legal abortion.

METHODS AND RESULTS

In NCC, quantitative real-time RT PCR demonstrated the expression of neural crest specifier genes, such as Snail1, Snail2/SLUG, Sox10, FoxD3, c-Myc, and p75NTR. Moreover, these cell populations expressed stemness markers (such as Nanog and nestin), as well as markers of motility and invasion (TAGLN, MMP9, CXCR4, and CXCR7), and of neuronal/glial differentiation (MAP2, GFAP, SYP, and TAU). Functional analysis demonstrated that these cells not only possessed high migration properties, but most importantly, they expressed markers of sympatho-adrenal lineage, such as ASCL1 and tyrosine hydroxylase (TH). Moreover, the expression of TH increased after the induction with two different protocols of differentiation towards neuronal and sympatho-adrenal phenotypes. Finally, exposure to conditioned culture media from NCC induced a mature phenotype in a neuronal cell model (namely SH-SY5Y), suggesting that NCC may also act like Schwann precursors.

CONCLUSION

This unique human cell model provides a solid tool for future studies addressing the bases of human neural crest-derived neuroendocrine tumours.

Involving schoolchildren in radon surveys by means of the "RadonTest" online system

A 'citizen science' approach was evaluated as an approach to organize an extensive radon survey to be representative of the population of either single regions or a whole country. The "RadonTest" online system allowed schoolchildren to undertake and record short-term radon tests in their homes. Measurements were carried out in Israel using charcoal in miniature flacons and simple detectors with high sensitivity. Among other things, the "RadonTest" online system implements an alternative principle of building a radon map, allowing the display of radon tests more clearly than the traditional approach, while ensuring the confidentiality of test participants. Examples of public radon maps are presented, and the first test results are discussed. A scientifically based approach for the effective identification of buildings with a high radon concentration, based on the principle of radon regulation, is proposed.

Endocrine toxicity in cancer patients treated with nivolumab or pembrolizumab: results of a large multicentre study

INTRODUCTION

The immune checkpoint inhibitors (ICPIs) agents anti-T lymphocytes-associated antigen 4 (CTLA-4) and anti-programmed cell death protein-1 (PD-1) and its ligands (PD-L1/PD-L2) have opened a new scenario in the treatment of cancer. These agents can induce immuno-related adverse events (irAEs), which may affect the endocrine system.

PURPOSE

The aim of this study was to analyze the occurrence and the course of endocrine irAEs in cancer patients treated with anti-PD-1 immunotherapy.

METHODS

This was a retrospective, multicentre study, involving cancer patients treated with the PD-1 inhibitors nivolumab or pembrolizumab at reference Oncology Centres. One hundred and seventy-nine consecutive patients with different types of cancer (mostly non-small cell lung cancer, melanoma, kidney cancer) were included in the study. Patients had received nivolumab (70.9%) or pembrolizumab (29.1%) for 2-33 months. The study evaluated clinical data records until the established date of July 15, 2018. The primary end point was the assessment of endocrine toxicity and possible predictive factors.

RESULTS

Endocrine toxicity occurred in 54 out of 179 patients (30.2%) and was related to thyroid dysfunction, with the exception of one case of diabetes mellitus. Thyroid toxicity occurred mostly within 2 months from the initiation of immunotherapy (83% of cases). A pre-existing thyroid dysfunction was a significant predictor of disease flare.

CONCLUSIONS

Thyroid alterations are frequently associated with anti PD-1 treatment in cancer patients. Regular thyroid assessment should be performed, particularly in the first months of treatment and in patients with a pre-existing thyroid disease.

Toward the improvement of 3D-printed vessels' anatomical models for robotic surgery training

Multi-Detector Computed Tomography is nowadays the gold standard for the pre-operative imaging for several surgical interventions, thanks to its excellent morphological definition. As for vascular structures, only the blood flowing inside vessels can be highlighted, while vessels' wall remains mostly invisible. Image segmentation and three-dimensional-printing technology can be used to create physical replica of patient-specific anatomy, to be used for the training of novice surgeons in robotic surgery. To this aim, it is fundamental that the model correctly resembles the morphological properties of the structure of interest, especially concerning vessels on which crucial operations are performed during the intervention. To reach the goal, vessels' actual size must be restored, including information on their wall. Starting from the correlation between vessels' lumen diameter and their wall thickness, we developed a semi-automatic approach to compute the local vessels' wall, bringing the vascular structures as close as possible to their actual size. The optimized virtual models are suitable for manufacturing by means of three-dimensional-printing technology to build patient-specific phantoms for the surgical simulation of robotic abdominal interventions. The proposed approach can effectively lead to the generation of vascular models of optimized thickness wall. The feasibility of the approach is also tested on a selection of clinical cases in abdominal surgery, on which the robotic surgery is performed on the three-dimensional-printed replica before the actual intervention.

Breast Carcinoma Metastatic to the Ethmoid Sinus: A Case Report

We report a rare case of breast carcinoma metastatic to the ethmoid sinus. An 83-year-old female patient with an intraductal breast carcinoma presented the first symptoms of metastasis to the paranasal sinuses four years after radical mastectomy and axillary node dissection. A review of the literature revealed that only three such cases have been described so far. Symptoms and imaging results are not specific and usually similar to those of primary neoplasms in this region. This case underlines the importance of suspecting a metastasis in patients with a history of malignancy.

Hypothyroidism and hyponatremia: data from a series of patients with iatrogenic acute hypothyroidism undergoing radioactive iodine therapy after total thyroidectomy for thyroid cancer

PURPOSE

The aim of the present study was to evaluate the role of hypothyroidism as a cause of hyponatremia in a clinical model of iatrogenic acute hypothyroidism due to thyroid hormone withdrawal prior to ablative radioactive iodine (RAI) therapy after total thyroidectomy.

METHODS

The study group consisted of 101 differentiated thyroid cancer (DTC) patients (77 women and 24 men). Plasma concentration of thyroid-stimulating hormone ([TSH]) and sodium ([Na⁺]) was evaluated before total thyroidectomy (pre[TSH] and pre[Na⁺]) and on the day of RAI therapy (post[TSH] and post[Na⁺]).

RESULTS

The frequency of hypothyroidism-associated hyponatremia was 4 % (4/101). Pre[Na⁺] was significantly higher than post[Na⁺] (140.7 ± 1.6 vs 138.7 ± 2.3 mEq/L, p = 0.012). Moreover, a linear correlation was identified between pre[Na⁺] and post[Na⁺].

CONCLUSIONS

Iatrogenic acute hypothyroidism-related hyponatremia is uncommon. However, because of the significant reduction of [Na⁺] in the transition from euthyroidism to iatrogenic hypothyroidism, the value of pre[Na⁺] should be viewed as a parameter to be considered. Since it acts as an independent risk factor for the development of hyponatremia, patients with a pre[Na⁺] close to the lower limit of normal range may deserve a closer monitoring of [Na⁺].

Low extracellular sodium promotes adipogenic commitment of human mesenchymal stromal cells: a novel mechanism for chronic hyponatremia-induced bone loss

Hyponatremia represents an independent risk factor for osteoporosis and fractures, affecting both bone density and quality. A direct stimulation of bone resorption in the presence of reduced extracellular sodium concentrations ([Na(+)]) has been shown, but the effects of low [Na(+)] on osteoblasts have not been elucidated. We investigated the effects of a chronic reduction of extracellular [Na(+)], independently of osmotic stress, on human mesenchymal stromal cells (hMSC) from bone marrow, the common progenitor for osteoblasts and adipocytes. hMSC adhesion and viability were significantly inhibited by reduced [Na(+)], but their surface antigen profile and immuno-modulatory properties were not altered. In low [Na(+)], hMSC were able to commit toward both the osteogenic and the adipogenic phenotypes, as demonstrated by differentiation markers analysis. However, the dose-dependent increase in the number of adipocytes as a function of reduced [Na(+)] suggested a preferential commitment toward the adipogenic phenotype at the expense of osteogenesis. The amplified inhibitory effect on the expression of osteoblastic markers exerted by adipocytes-derived conditioned media in low [Na(+)] further supported this observation. The analysis of cytoskeleton showed that low [Na(+)] were associated with disruption of tubulin organization in hMSC-derived osteoblasts, thus suggesting a negative effect on bone quality. Finally, hMSC-derived osteoblasts increased their expression of factors stimulating osteoclast recruitment and activity. These findings confirm that hyponatremia should be carefully taken into account because of its negative effects on bone, in addition to the known neurological effects, and indicate for the first time that impaired osteogenesis may be involved.

Neuronal distress induced by low extracellular sodium in vitro is partially reverted by the return to normal sodium

BACKGROUND

Hyponatremia is associated with negative clinical outcomes even when chronic and mild. It is also known that hyponatremia treatment should be appropriately performed, to avoid dramatic consequences possibly leading to death. We have previously demonstrated that chronically low extracellular [Na(+)], independently of reduced osmolality, is associated with signs of neuronal cell distress, possibly involving oxidative stress.

AIM

The aim of the present study was to assess whether the return to normal extracellular [Na(+)] is able to revert neuronal cell damage.

METHODS

After exposing SH-SY5Y and SK-N-AS cells to low [Na(+)] and returning to normal [Na(+)], we analyzed cell viability by MTS assay, ROS accumulation by FASCan and expression of anti-apoptotic genes.

RESULTS

We found that the viability of cells was restored upon return to normal [Na(+)]. However, when more subtle signs of cell distress were assessed, such as the expression level of the anti-apoptotic genes Bcl-2 and DHCR24 or of the heme oxygenase 1 gene, a complete return to basal values was not observed, in particular in SK-N-AS, even when [Na(+)] was gradually increased. We also demonstrated that the amount of ROS significantly increased in low [Na(+)], thus confirming that oxidative stress appears to contribute to the effects of low [Na(+)] on cell homeostasis.

CONCLUSIONS

Overall, this study provided the first demonstration that the correction of chronically low extracellular [Na(+)] may not be able to revert all the cell alterations associated with reduced [Na(+)]. These results suggest that prompt hyponatremia treatment might prevent possible residual abnormalities.

Neuroprotective effects of estrogens: the role of cholesterol

INTRODUCTION

Experimental and clinical evidence suggests that estrogens have protective effects in the brain. Nevertheless, their potential role against neurodegenerative diseases, in particular Alzheimer's disease (AD), is still a matter of debate. The identification of the seladin-1 gene (for SELective Alzheimer's Disease INdicator-1), which appeared to be significantly less expressed in brain region affected in AD, opened a new scenario in the field of neuroprotective mechanisms. Seladin-1 was found to have neuroprotective properties through its anti-apoptotic activity. In addition, it was subsequently demonstrated that seladin-1 also has enzymatic activity, because it catalyzes the conversion of desmosterol into cholesterol. Several studies have shown that an appropriate amount of membrane cholesterol plays a pivotal role to protect nerve cells against β-amyloid toxicity in AD and to counteract the synthesis of β-amyloid.

METHODS AND RESULTS

We demonstrated that the expression of seladin-1, as well as the synthesis of cell cholesterol, is stimulated by estrogens in human neuronal precursor cells. Cholesterol enriched cells became more resistant against oxidative stress and β-amyloid toxicity. We thus hypothesized that seladin-1 might be a mediator of the neuroprotective effects of estrogens. Indeed, in cells in which seladin-1 gene expression had been silenced by siRNA the protective effects of estrogens were lost. This finding indicates that seladin-1 is a crucial mediator of the neuroprotective effects of these hormones, at least in our cell model.

CONCLUSIONS

In summary, these results establish a new link between estrogens and cholesterol, which is represented by the neuroprotective factor seladin-1.

Perivascular fibrosis and IgG4-related disease: a case report

Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized fibroinflammatory condition which can potentially involve any organ. Some characteristic histopathologic features with lymphoplasmacytic infiltrate, an increased number of IgG4+ cells, storiform fibrosis and obliterative phlebitis are the mainstay for diagnosis. Serum IgG4 levels often increase. We report the case of a patient with perivascular fibrotic lesions involving the aortic arch and the splenic hilum, with a surgical biopsy-proven diagnosis of IgG4-related disease. The patient is now undergoing a low-dose corticosteroid maintenance therapy without evidence of new localizations of the disease. This case highlights the need for increasing awareness and recognition of this new, emerging clinical condition.

Management of euvolemic hyponatremia attributed to SIADH in the hospital setting

Hyponatremia is the most frequent electrolyte disorder in hospitalized patients. Acute and severe hyponatremia can be a life-threatening condition, but recent evidence indicates that also mild and chronic hyponatremia is associated with neurological and extra-neurological signs, such as gait disturbances, attention deficits, falls and fracture occurrence, and bone loss. The syndrome of inappropriate ADH secretion (SIADH) is the most frequent cause of hyponatremia. Hyponatremia secondary to SIADH may result for instance from ectopic release of ADH in lung cancer, from diseases affecting the central nervous system, from pneumonia or other pneumopathies or as a side-effect of various drugs In SIADH, hyponatremia results from a pure disorder of water handling by the kidney, whereas external sodium balance is usually well regulated. Despite increased total body water, only minor changes of urine output and modest oedema are usually seen. Neurological impairment may range from subclinical to life-threatening, depending on the degree and mostly on the rate of serum sodium reduction. The management of hyponatremia secondary to SIADH is largely dependent on the symptomatology of the patient. This review briefly summarizes the main aspects related to hyponatremia and then discusses the available treatment options for the management of SIADH, including vaptans, which are vasopressin receptor antagonists targeted for the correction of euvolemic hyponatremia, such as that observed in SIADH.

Role of UGT1A1 and ADH gene polymorphisms in pegvisomant-induced liver toxicity in acromegalic patients

CONTEXT

Hepatotoxicity is one of the most serious adverse effects in acromegalic patients treated with pegvisomant (PEG-V). Recent studies have found an association between this adverse event and the UGT1A1 allele 28 polymorphism associated with Gilbert's syndrome.

OBJECTIVE

To determine whether UGT1A1*28 and alcohol dehydrogenase (ADH) polymorphisms influence liver toxicity during PEG-V treatment.

DESIGN AND SETTING

Multicenter observational retrospective study conducted in 13 tertiary care endocrinology units in Italy.

PATIENTS

A total of 112 patients with active disease resistant to somatostatin analogs (SSTa) and 108 controls were enrolled.

INTERVENTIONS

Clinical and biochemical data were recorded by electronic clinical reporting forms. Blood or DNA samples were sent to the coordinating center for genotyping.

RESULTS

No differences in genotypes between patients and controls were found. During PEG-V therapy liver function tests (LFT), abnormalities and overt hepatotoxicity developed in 17 and 4.5% of patients respectively. Logistic and linear regression analyses showed an association between LFT abnormalities during the follow-up visit and prior events of LFT abnormalities in medical history (odds ratio=1.25; P=0.04) and the number of concomitant medications, other than SSTa (B=3.9; P=0.03). No correlation between LFT alterations and UGT1A1 allele 28 as well as ADH1C and B polymorphisms was found.

CONCLUSIONS

UGT1A1 allele 28 and ADH1C and B polymorphisms do not predict increased risk of hepatotoxicity during PEG-V therapy. Conversely, patients with multi-therapies and with previous episodes of liver disease should be carefully managed, due to the observed association between these conditions and LFT abnormalities during PEG-V therapy.

Awareness and management of hyponatraemia: the Italian Hyponatraemia Survey

BACKGROUND

Hyponatraemia is the most frequent electrolyte disorder in hospitalized patients and has been associated with increased morbidity, mortality and length of hospital stay. There is evidence that also mild chronic hyponatraemia may have clinical consequences, such as gait disturbances, attention deficits, falls, increased risk of fractures and reduced bone mineral density. Nevertheless, this condition appears to be rather often not taken into consideration, or inappropriately managed and treated, thus negatively affecting patients' outcome.

AIM

The aim of this study was to investigate the awareness and management of hyponatraemia secondary to SIAD, a common cause of hyponatraemia, among Italian physicians (endocrinologists, nephrologists, internists) commonly involved as consultants.

METHODS

A questionnaire, covering definition, diagnosis, management, treatment and prognosis of hyponatraemia secondary to SIAD, was developed with the support of the Italian Society of Endocrinology.

RESULTS

Among the respondents (n=275), the majority was aware of the negative implications of hyponatraemia or of an inappropriate treatment. Nevertheless, the answers indicated that SIAD is still underdiagnosed and incorrectly managed in clinical practice. In particular, only 47% of respondents used the validated biochemical parameters to diagnose hyponatraemia secondary to SIAD. The survey also indicated a rather satisfactory knowledge of the therapeutic options, including the currently available vasopressin receptor antagonists.

CONCLUSIONS

One of the main findings of the survey was that the diagnostic work-up of hyponatraemia still represents a critical issue. Therefore, there is urgent need of educational programs in order to improve the management of this condition and reduce morbidity, mortality and costs.

Assessment of sleep apnea syndrome in treated acromegalic patients and correlation of its severity with clinical and laboratory parameters

BACKGROUND

Sleep apnea syndrome (SAS) is a frequent disorder in acromegalic patients and its frequency ranges from 45 to 87.5% of patients. Obstructive SAS is the prevailing form in acromegaly and its pathogenesis is based on craniofacial deformations and thickening of soft tissues and mucosas of upper airways and bronchi. Central and mixed types are less frequent. Respiratory complications, and SAS in particular, may contribute to the increased mortality observed in acromegaly.

AIM

Aim of the present study is to assess the presence of SAS in acromegalic patients, its features and to correlate the severity of SAS with factors such as disease duration, body mass index (BMI), smoking, GH/IGF-I serum levels, associated comorbidities.

SUBJECTS AND METHODS

Polygraphy (SOMNOcheck Effort Weinmann V2.05) was performed in 25 consecutive acromegalic patients (9 men and 16 women). Statistical analysis was performed with Mann-Whitney's test and Spearman coefficient.

RESULTS

Fourteen out of 25 patients (56%) were affected by SAS. The prevailing form was obstructive SAS (12/14 patients). Smoking, female gender, and presence of lung disease appear to lead to a more severe form. We also found that the prevalence of hypertension was significantly higher in the group of patients with SAS, whereas no correlation was proved among SAS and disease duration, GH/IGF-I serum levels, somatostatin analogs treatment, BMI, and associated comorbidities.

CONCLUSIONS

SAS is a frequent complication of acromegaly. Severe forms seem to be correlated with smoking and lung disease. Therefore, all acromegalic patients should be subjected to a polygraphic study for an early diagnosis and treatment and smoking should be discouraged.

Relationship between the neuroprotective effects of insulin-like growth factor-1 and 17β-oestradiol in human neuroblasts

Insulin-like growth factor-1 (IGF-1) and oestrogens interact with each other as neuroprotective factors. We have previously demonstrated that 17β-oestradiol protects against β-amyloid and oxidative stress toxicity and increases the amount of cell cholesterol in human foetal neuroblasts (FNC). The present study aimed: (i) to assess the protective effects of IGF-1 in FNC cells; (ii) to investigate the relationship between IGF-1 and 17β-oestradiol; and (iii) to determine whether cholesterol was a major mediator of the effects of IGF-1, similarly to 17β-oestradiol. We found that IGF-1 effectively exerts neuroprotective effects in FNC cells. We also demonstrated that the IGF-1 receptor (IGF-1R) pathway is needed to maintain oestrogen-mediated neuroprotection. Finally, we found that, opposite to 17β-oestradiol, IGF-1 did not cause a significant increase in cell cholesterol. These findings indicate that a cross-talk between IGF-1 and 17β-oestradiol occurs in FNC cells. In particular, the activation of the IGF-1R cascade appears to be fundamental to warrant 17β-oestradiol-mediated neuroprotection, even though cell cholesterol does not play a major role as an effector of this pathway.

Predictors of morbidity and mortality in acromegaly: an Italian survey

OBJECTIVE

To describe demographic and hormonal characteristics, comorbidities (diabetes mellitus and hypertension), therapeutic procedures and their effectiveness, as well as predictors of morbidity and mortality in a nationwide survey of Italian acromegalic patients.

DESIGN

Retrospective multicenter epidemiological study endorsed by the Italian Society of Endocrinology and performed in 24 tertiary referral Italian centers. The mean follow-up time was 120 months.

RESULTS

A total of 1512 patients, 41% male, mean age: 45±13 years, mean GH: 31±37 μg/l, IGF1: 744±318 ng/ml, were included. Diabetes mellitus was reported in 16% of cases and hypertension in 33%. Older age and higher IGF1 levels at diagnosis were significant predictors of diabetes and hypertension. At the last follow-up, 65% of patients had a controlled disease, of whom 55% were off medical therapy. Observed deaths were 61, with a standardized mortality ratio of 1.13 95% (confidence interval (CI): 0.87-1.46). Mortality was significantly higher in the patients with persistently active disease (1.93; 95% CI: 1.34-2.70). Main causes of death were vascular diseases and malignancies with similar prevalence. A multivariate analysis showed that older age, higher GH at the last follow-up, higher IGF1 levels at diagnosis, malignancy, and radiotherapy were independent predictors of mortality.

CONCLUSIONS

Pretreatment IGF1 levels are important predictors of morbidity and mortality in acromegaly. The full hormonal control of the disease, nowadays reached in the majority of patients with modern management, reduces greatly the disease-related mortality.

Androgens and estrogens prevent rosiglitazone-induced adipogenesis in human mesenchymal stem cells

Thiazolidinediones (TZD), a class of anti-diabetic drugs, determine bone loss and increase fractures particularly in post-menopausal women, thus suggesting a protective role of sex steroids. We have previously demonstrated that the TZD rosiglitazone (RGZ) negatively affects bone mass by inhibiting osteoblastogenesis, yet inducing adipogenesis, in bone marrow-derived human mesenchymal stem cells (hMSC). The aim of this study was to determine whether estrogens and androgens are able to revert the effects of RGZ on bone. hMSC express estrogen receptor α and β and the androgen receptor. We found that 17β-estradiol (10 nM), the phytoestrogen genistein (10 nM), testosterone (10 nM) and the non-aromatizable androgens dihydrotestosterone (10 nM) and methyltrienolone (10 nM) effectively counteracted the adipogenic effect of RGZ (1 μM) in hMSC induced to differentiate into adipocytes, as determined by evaluating the expression of the adipogenic marker peroxisome proliferator-activated receptor γ and the percentage of fat cells. Furthermore, when hMSC were induced to differentiate into osteoblasts, all the above-mentioned molecules and also quercetin, another phytoestrogen, significantly reverted the inhibitory effect of RGZ on the expression of the osteogenic marker osteocalcin and decreased the number of fat cells observed after RGZ exposure. Our study represents, to our knowledge, the first demonstration in hMSC that androgens, independently of their aromatization, and estrogens are able to counteract the negative effects of RGZ on bone. Our data, yet preliminary, suggest the possibility to try to prevent the negative effects of TZD on bone, using steroid receptor modulators, such as plant-derived phytoestrogens, which lack evident adverse effects.

Growth hormone receptor variants and response to pegvisomant in monotherapy or in combination with somatostatin analogs in acromegalic patients: a multicenter study

CONTEXT

The influence of full-length GH receptor (GHR) and exon 3-deleted GHR (d3GHR) on responsiveness to pegvisomant (PEG-V) in acromegalic patients is uncertain.

OBJECTIVE

The aim of the study was to assess the distribution of GHR genotypes in a large series of patients on PEG-V therapy and their influence on treatment efficacy and adverse effects.

DESIGN AND SETTING

A cross-sectional multicenter pharmacogenetic study was conducted in 16 Italian endocrinology centers of major universities and tertiary care hospitals.

PATIENTS

The study included 127 acromegalic patients enrolled from 2009 to 2010 not cured by previous surgery, radiotherapy, and long-acting somatostatin (SST) analogs, treated with PEG-V.

INTERVENTION AND MAIN OUTCOME MEASURE

Sixty-three of 127 patients received combined PEG-V + SST analog therapy. Clinical and hormonal data at diagnosis and before and during PEG-V therapy were inserted in a database. GHR exon 3 deletion and other polymorphisms were genotyped by the coordinator center. Differences in PEG-V dosage required for IGF-I normalization and occurrence of adverse effects between carriers and noncarriers of GHR variants were evaluated.

RESULTS

d3GHR variants were not in Hardy-Weinberg equilibrium (P = 0.008). No association of these variants with PEG-V dose required for IGF-I normalization, adverse effects occurrence, and tumor regrowth was found in patients on PEG-V and on PEG-V + SST analog treatment. Similar data were obtained considering the GHR variant rs6180.

CONCLUSIONS

This study did not confirm a better response of d3GHR to PEG-V treatment in acromegaly. Other studies are needed to determine whether deviation from Hardy-Weinberg equilibrium may indicate an association of d3GHR genotype with poor response to usual treatments.

Evaluation of the anterior pituitary function in the acute phase after spontaneous subarachnoid hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a potential cause of hypopituitarism. Most of the studies regarding the relationship between SAH and anterior pituitary function were retrospective and hormonal assessment was performed several months after SAH.

AIM

To prospectively evaluate the prevalence of anterior pituitary hormone deficiencies in the acute phase after spontaneous SAH and their possible correlation with clinical and radiological parameters.

METHODS

Pituitary function was tested in 60 patients within 72 h after spontaneous SAH.

RESULTS

56.9% of the patients showed at least one anterior pituitary hormone deficiency: gonadotropin and GH secretion failure represented the most prevalent hormonal deficiencies (33.3 and 22.0%, respectively), whereas ACTH and TSH deficiency was less frequent (7.1 and 1.8%, respectively). With the exception of secondary hypogonadism, the prevalence of other pituitary hormone deficiencies is in agreement with previous studies, which evaluated pituitary function on longterm follow up after SAH. No correlation was found between hypopituitarism and clinical status, as assessed with Hunt-Hess and Glascow Coma Scales. Moreover, no correlation was found between hypopituitarism and bleeding severity evaluated with Fisher's scale.

CONCLUSIONS

We demonstrated a high prevalence of anterior pituitary hormone deficiencies acutely after SAH. Although part of GH and gonadotropin deficiencies might be a consequence of functional alteration due to SAH itself, the finding of low cortisol levels in this stressful condition strongly suggests the presence of true hypocortisolism. Therefore, an evaluation of pituitary function shortly after SAH might be useful to identify a subset of patients who deserve a more accurate follow-up.

Membrane cholesterol as a mediator of the neuroprotective effects of estrogens

Alzheimer's disease (AD), the most common neurodegenerative disease associated with aging, is still an incurable condition. Although in vitro evidence strongly indicates that estrogens exert neurotrophic and neuroprotective effects, the role of this class of hormones in the treatment of AD is still a debated issue. In 2000 a new gene, named seladin-1 (for SELective Alzheimer's Disease INdicator-1), was identified and found to be down regulated in vulnerable brain regions in AD. Seladin-1 was considered a novel neuroprotective factor, because of its anti-apoptotic activity. Subsequently, it was demonstrated that seladin-1 has also enzymatic activity [3-β-hydroxysterol delta-24-reductase, (DHCR24)], which catalyzes the synthesis of cholesterol from desmosterol. The amount of membrane cholesterol may play an important role both in protecting neuronal cells against toxic insults and in inhibiting the production of β-amyloid. We demonstrated that seladin-1 overexpression increases the amount of membrane cholesterol and induces resistance against β-amyloid aggregates in neuroblastoma cells, whereas a specific inhibitor of DHCR24 increased cell vulnerability. We also hypothesized that seladin-1 might be a mediator of the neuroprotective effects of estrogens. We first demonstrated that, in human fetal neuroepithelial cells (FNC), 17β-estradiol, raloxifene, and tamoxifen exert protective effects against β-amyloid toxicity and oxidative stress. In addition, these molecules significantly increased the expression of seladin-1 and the amount of cell cholesterol. Then, we showed that, upon seladin-1 silencing, the protective effects of estrogens were abolished, thus indicating this factor as a fundamental mediator of estrogen-mediated neuroprotection, at least in FNC cells. Furthermore, we detected the presence of functionally active half-palindromic estrogen responsive elements upstream the coding region of the seladin-1 gene. Overall, our results indicate that seladin-1 may be viewed as a multi-faceted protein, which conjugates both the neuroprotective properties of estrogens and the important functions of cholesterol in maintaining brain homeostasis. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain.

An integrated suite of fast docking algorithms

The CAPRI experiment (Critical Assessment of Predicted Interactions) simulates realistic and diverse docking challenges, each case having specific properties that may be exploited by docking algorithms. Motivated by the different CAPRI challenges, we developed and implemented a comprehensive suite of docking algorithms. These were incorporated into a dynamic docking protocol, consisting of four main stages: (1) Biological and bioinformatics research aiming to predict the binding site residues, to define distance constraints between interface atoms and to analyze the flexibility of molecules; (2) Rigid or flexible docking, performed by the PatchDock or FlexDock method, which utilizes the information gathered in the previous step. Symmetric complexes are predicted by the SymmDock method; (3) Flexible refinement and reranking of the rigid docking solution candidates, performed by FiberDock; and finally, (4) clustering and filtering the results based on energy funnels. We analyzed the performance of our docking protocol on a large benchmark and on recent CAPRI targets. The analysis has demonstrated the importance of biological information gathering prior to docking, which significantly increased the docking success rate, and of the refinement and rescoring stage that significantly improved the ranking of the rigid docking solutions. Our failures were mostly a result of mishandling backbone flexibility, inaccurate homology modeling, or incorrect biological assumptions. Most of the methods are available at http://bioinfo3d.cs.tau.ac.il/.

Robotic-assisted laparoscopic donor nephrectomy with transvaginal extraction of the kidney

Transvaginal recovery of the kidney has recently been reported, in a donor who had previously undergone a hysterectomy, as a less-invasive approach to perform laparoscopic live-donor nephrectomy. Also, robotic-assisted laparoscopic kidney donation was suggested to enhance the surgeon's skills during renal dissection and to facilitate, in a different setting, the closure of the vaginal wall after a colpotomy. We report here the technique used for the first case of robotic-assisted laparoscopic live-donor nephrectomy with transvaginal extraction of the graft in a patient with the uterus in place. The procedure was carried out by a multidisciplinary team, including a gynecologist. Total operative time was 215 min with a robotic time of 95 min. Warm ischemia time was 3 min and 15 s. The kidney was pre-entrapped in a bag and extracted transvaginally. There was no intra- or postoperative complication. No infection was seen in the donor or in the recipient. The donor did not require postoperative analgesia and was discharged from the hospital 24 h after surgery. Our initial experience with the combination of robotic surgery and transvaginal extraction of the donated kidney appears to open a new opportunity to further minimize the trauma to selected donors.

Hyponatremia and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH)

The syndrome of inappropriate ADH secretion (SIADH), also recently referred to as the "syndrome of inappropriate antidiuresis", is an often underdiagnosed cause of hypotonic hyponatremia, resulting for instance from ectopic release of ADH in lung cancer or as a side-effect of various drugs. In SIADH, hyponatremia results from a pure disorder of water handling by the kidney, whereas external Na+ balance is usually well regulated. Despite increased total body water, only minor changes of urine output and modest edema are usually seen. Renal function and acid-base balance are often preserved, while neurological impairment may range from subclinical to life-threatening. Hypouricemia is a distinguishing feature. The major causes and clinical variants of SIADH are reviewed, with particular emphasis on iatrogenic complications and hospital-acquired hyponatremia. Effective treatment of SIADH with water restriction, aquaretics, or hypertonic saline + loop diuretics, as opposed to worsening of hyponatremia during parenteral isotonic fluid administration, underscores the importance of an early accurate diagnosis and careful follow-up of these patients.

A single-institution restrospective experience of brachytherapy in the treatment of pituitary tumors: transsphenoidal approach combined with (192)Ir-afterloading catheters

BACKGROUND AND AIM

Radiotherapy may be used as an adjuvant treatment of pituitary adenomas. The aim of our study was to present our experience of multimodal treatment of pituitary adenomas, consisting in temporary implantation of (192)Ir-labeled wires following transphenoidal surgery.

SUBJECTS AND METHODS

An observational investigation was performed on a series of 80 patients undergoing surgery (S) for pituitary adenomas between 1982 and 2000, some of whom received post-operative external beam radiotherapy (EBRT) (no.=19 between 1982 and 1990), brachytherapy (B) (no.=35, all after 1991), or both irradiation modalities (EBRT+B) (no.=14). The different treatments were compared in terms of hormonal normalization in the subgroup of patients with hypersecreting adenomas, tumor control, and side effects.

RESULTS

Hormonal normalization was obtained in 84% of S+B patients and in 61% of S+EBRT patients. Tumor control was obtained in 74.3% of S+B patients and in 63.1% of S+EBRT patients. Anterior pituitary hormones deficits ranged from 8.6-34% in S+B patients and from 15.8-47.4% in S+EBRT patients, after a mean follow-up of 14 yr. The latter group also showed a higher rate of multiple deficits (42.1% vs 22.8%). Diabetes insipidus and other major complications were rare events in all groups.

CONCLUSIONS

We presented one original experience regarding brachytherapy in the management of pituitary tumors, which turned out to be effective and safe. Additional prospective, and possibly randomized, studies should clarify whether in the era of 3-dimensional conformal radiotherapy and stereotactic radiotherapy this treatment modality may still have a role.

In vivo effects of rosiglitazone in a human neuroblastoma xenograft

BACKGROUND

Neuroblastoma (NB) is the most common extra-cranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. There is in vitro evidence that the peroxisome proliferator-activated receptor gamma (PPARgamma) might be a target for pharmacological intervention in NB. We have previously demonstrated that the PPARgamma agonist rosiglitazone (RGZ) exerts strong anti-tumoural effects in the human NB cell line, SK-N-AS. The aim of this study was to evaluate whether RGZ maintains its anti-tumoural effects against SK-N-AS NB cells in vivo.

METHODS AND RESULTS

For this purpose, tumour cells were subcutaneously implanted in nude mice, and RGZ (150 mg kg(-1)) was administered by gavage daily for 4 weeks. At the end of treatment, a significant tumour weight inhibition (70%) was observed in RGZ-treated mice compared with control mice. The inhibition of tumour growth was supported by a strong anti-angiogenic activity, as assessed by CD-31 immunostaining in tumour samples. The number of apoptotic cells, as determined by cleaved caspase-3 immunostaining, seemed lower in RGZ-treated animals at the end of the treatment period than in control mice, likely because of the large tumour size observed in the latter group.

CONCLUSIONS

To our knowledge, this is the first demonstration that RGZ effectively inhibits tumour growth in a human NB xenograft and our results suggest that PPARgamma agonists may have a role in anti-tumoural strategies against NB.

Intermittent high glucose concentrations reduce neuronal precursor survival by altering the IGF system: the involvement of the neuroprotective factor DHCR24 (Seladin-1)

The exposure of neurons to high glucose concentrations is considered a determinant of diabetic neuropathy, whereas members of the IGF system are neurotropic factors. Here, we investigated the effects of constant and intermittent high glucose concentrations on IGF1 and IGF-binding proteins (IGFBPs) in human neuroblast long-term cell cultures fetal neuroepithelial cells (FNC). These cells express the IGF1 receptor, and express and release in the culture medium IGFBP2, IGFBP4, and IGF1. The release of IGF1 was significantly increased by 17beta-estradiol (10 nM). IGF1 (100 nM) treatment determined a significant increase of IGFBP2 and a decrease of IGFBP4 release. In addition, IGF1 (1-100 nM) stimulated FNC cell proliferation in a dose-dependent manner. We hypothesized that this effect may be, at least partially, due to IGF1-induced up-regulation of the expression of the Alzheimer's disease related gene SELADIN-1 (now known as DHCR24 ), which acts as a pro-survival factor for neuronal cells. Conversely, the exposure to intermittent (20/10 mM), but not stable (20 mM), high glucose concentrations decreased the release of IGF1 and IGFBP2 in the culture medium and inhibited FNC growth by inducing apoptosis. The latter was prevented by the addition of IGF1 to the culture medium. Furthermore, high glucose concentrations reduced the expression of DHCR24. In conclusion, our results indicate for the first time that intermittent high glucose concentrations, similar to those observed in poorly controlled diabetic patients, may contribute to the development of diabetic neuropathy by interfering with the tropic effects exerted by the IGF system, and suggest the involvement of the neuroprotective factor DHCR24.

Thyroid hormones promote cell differentiation and up-regulate the expression of the seladin-1 gene in in vitro models of human neuronal precursors

Thyroid hormones (TH) play an important role in the development of human brain, by regulating the expression of specific genes. Selective Alzheimer's disease indicator-1 (seladin-1) is a recently discovered gene with neuroprotective properties, which has been found to be down-regulated in brain regions affected by Alzheimer's disease. Seladin-1 has anti-apoptotic properties mainly due to the inhibition of the activation of caspase 3. The aim of this study was to determine whether seladin-1 may be regarded as a new mediator of the effects of TH in the developing brain. In order to demonstrate this hypothesis, the effects of TH both on cell differentiation and on the expression of seladin-1 were assessed in two different cell models, i.e. fetal human neuroepithelial cells (FNC) and human mesenchymal stem cells (hMSC), which can be differentiated into neurons. 3,3',5-Triiodothyronine (T3) determined different biological responses (inhibition of cell adhesion, induction of migration, and increase in the expression of the neuronal marker neurofilament-M and Na+ and Ca2+ channel functionality) in both FNC and hMSC, which express TH receptors. Then, we showed that TH significantly increase the expression levels of seladin-1, and that T3 effectively prevents camptothecin-induced apoptosis. However, in hMSC-derived neurons the expression of seladin-1 was not affected by TH. Our results demonstrated for the first time that seladin-1 is a novel TH-regulated gene in neuronal precursors. In view of its anti-apoptotic activity, it might be hypothesized that one of the functions of the increased seladin-1 levels in the developing brain may be to protect neuronal precursor cells from death.

Seladin-1/DHCR24 protects neuroblastoma cells against Abeta toxicity by increasing membrane cholesterol content

The role of brain cholesterol in Alzheimer's disease (AD) is currently a matter of debate. Experimental evidence suggests that reducing circulating and brain cholesterol protects against AD, however recent data indicate that low membrane cholesterol results in neurode-generation and that the cholesterol synthesis catalyst seladin-1 is down-regulated in AD-affected brain regions. We previously reported a significant correlation between resistance to amyloid toxicity and content of membrane cholesterol in differing cultured cell types. Here we provide evidence that Abeta42 pre-fibrillar aggregates accumulate more slowly and in reduced amount at the plasma membrane of human SH-SY5Y neuroblastoma cells overexpressing seladin-1 or treated with PEG-cholesterol than at the membrane of control cells. The accumulation was significantly increased in cholesterol-depleted cells following treatment with the specific seladin-1 inhibitor 5,22E-cholestadien-3-ol or with methyl-beta-cyclodextrin. The resistance to amyloid toxicity and the early cytosolic Ca2+ rise following exposure to Abeta42 aggregates were increased and prevented, respectively, by increasing membrane cholesterol whereas the opposite effects were found in cholesterol-depleted cells. These results suggest that seladin-1-dependent cholesterol synthesis reduces membrane-aggregate interaction and cell damage associated to amyloid-induced imbalance of cytosolic Ca2+. Our findings extend recently reported data indicating that seladin-1 overexpression directly enhances the resistance to Abeta toxicity featuring seladin-1/DHCR 24 as a possible new susceptibility gene for sporadic AD.

Rosiglitazone stimulates adipogenesis and decreases osteoblastogenesis in human mesenchymal stem cells

Thiazolidinediones (TZD) are widely prescribed for the treatment of Type 2 diabetes. Increased loss of bone mass and a higher incidence of fractures have been associated with the use of this class of drugs in post-menopausal women. In vitro studies performed in rodent cell models indicated that rosiglitazone (RGZ), one of the TZD, inhibited osteoblastogenesis and induced adipogenesis in bone marrow progenitor cells. The objective of the present study was to determine for the first time the RGZ-dependent shift from osteoblastogenesis toward adipogenesis using a human cell model. To this purpose, bone marrow-derived mesenchymal stem cells were characterized and induced to differentiate along osteogenic and adipogenic lineages. We found that the exposure to RGZ potentiated adipogenic differentiation and shifted the differentiation toward an osteogenic phenotype into an adipogenic phenotype, as assessed by the appearance of lipid droplets. Accordingly, RGZ markedly increased the expression of the typical marker of adipogenesis fatty-acid binding protein 4, whereas it reduced the expression of Runx2, a marker of osteoblastogenesis. This is the first demonstration that RGZ counteracts osteoblastogenesis and induces a preferential differentiation into adipocytes in human mesenchymal stem cells.

Antineoplastic effects of rosiglitazone and PPARgamma transactivation in neuroblastoma cells

Neuroblastoma (NB) is the most common extracranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. In the present study, we evaluated the role of the peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone (RGZ) in two NB cell lines (SK-N-AS and SH-SY5Y), which express PPARγ. Rosiglitazone decreased cell proliferation and viability to a greater extent in SK-N-AS than in SH-SY5Y. Furthermore, 20 μM RGZ significantly inhibited cell adhesion, invasiveness and apoptosis in SK-N-AS, but not in SH-SY5Y. Because of the different response of SK-N-AS and SH-SY5Y cells to RGZ, the function of PPARγ as a transcriptional activator was assessed. Noticeably, transient transcription experiments with a PPARγ responsive element showed that RGZ induced a three-fold increase of the reporter activity in SK-N-AS, whereas no effect was observed in SH-SY5Y. The different PPARγ activity may be likely due to the markedly lower amount of phopshorylated (i.e. inactive) protein observed in SK-N-AS. To our knowledge, this is the first demonstration that the differential response of NB cells to RGZ may be related to differences in PPARγ transactivation. This finding indicates that PPARγ activity may be useful to select those patients, for whom PPARγ agonists may have a beneficial therapeutic effect.

Hyponatremia and pituitary adenoma: think twice about the etiopathogenesis

Pituitary adenomas may be the cause of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), although few cases have so far been reported. We described a case of hypotonic hyponatremia in a 76-yr-old man with a pituitary macroadenoma. He had a recent history of two syncopal attacks which had occurred in the last two months. Baseline assessment demonstrated a sodium serum level of 114 mEq/l. Clinically, the patient appeared euvolemic. Thyroid and adrenal function testing did not show any abnormality. Plasma and urinary osmolality (238 and 186 mOsm/kg, respectively) were in agreement with the diagnosis of SIADH. Accordingly, 3% hypertonic saline solution was started, followed by water intake restriction when natremia reached 126 mEq/l. A computed tomography (CT) scan of the chest revealed the presence of a 2-cm lesion in the azygos-esophageal recess. Because the nature of the lesion appeared uncertain, antibiotic therapy was initiated. After one month, a new CT scan did not show any evidence of the mediastinic mass. Sodium serum level was within the normal range (141 mEq/l) and remained stable thereafter, without fluid restriction. This case very well demonstrates that, in the presence of hyponatremia due to SIADH, more frequently associated co-morbidities (ie mediastinic diseases) have to be searched, even in the presence of a possible, yet rare, cause of this syndrome (ie pituitary adenoma).

Octreotide promotes apoptosis in human somatotroph tumor cells by activating somatostatin receptor type 2

Somatostatin analogs currently used in the treatment of acromegaly and other neuroendocrine tumors inhibit hormone secretion and cell proliferation by binding to somatostatin receptor type (SST) 2 and 5. The antiproliferative pathways coupled to these receptors have been only partially characterized. The aim of this study was to evaluate the effect of octreotide and super selective SST2 (BIM23120) and SST5 (BIM23206) analogs on apoptotic activity and apoptotic gene expression in human somatotroph tumor cells. Eight somatotroph tumors expressing similar levels of SST2 and SST5 evaluated by real-time PCR and western blot analyses were included in the study. In cultured cells obtained from these tumors, octreotide induced a dose-dependent increase of caspase-3 activity (160+/-20% vs basal at 10 nM) and cleaved cytokeratin 18 levels (172+/-25% vs basal) at concentrations higher than 0.1 nM. This effect was due to SST2 activation since BIM23120 elicited comparable responses, while BIM23206 was ineffective. BIM23120-stimulated apoptosis was dependent on phosphatases, since it was abrogated by the inhibitor orthovanadate, and independent from the induction of apoptosis-related genes, such as p53, p63, p73, Bcl-2, Bax, BID, BIK, TNFSF8, and FADD. In somatotroph tumors, both BIM23120 and BIM2306 caused growth arrest as indicated by the increase in p27 and decrease in cyclin D1 expression. In conclusion, the present study showed that octreotide-induced apoptosis in human somatotroph tumor cells by activating SST2. This effect, together with the cytostatic action exerted by both SST2 and SST5 analogs, might account for the tumor shrinkage observed in acromegalic patients treated with long-acting somatostatin analogs.

Specific features of differentiated thyroid carcinoma in patients over 70 years of age

BACKGROUND AND OBJECTIVES

Among the geriatric population, there is a lower incidence of thyroid carcinoma (TC), but it accounts for 30% of all thyroid disorders compared to 6-8% in younger subjects. Prognosis, moreover, is worse in the elderly, as demonstrated by the fact that 81% of deaths related to these tumors occur in patients over 55. The aim of this retrospective study was to identify the characteristics of differentiated thyroid carcinoma (DTC) peculiar to the elderly.

METHODS

Of 638 patients who underwent surgery for DTC over a period of 30 years, 46 were more than 70 years old. All the elderly patients had undergone radioioidine and TSH-suppression therapy following surgical resection.

RESULTS AND CONCLUSIONS

Despite these measures, the rate of recurrence was 26.5% at 5 years and 63.6% at 10 years. The 5- and 10-year disease-specific survival rates were 87.8% and 63.6%, respectively. On an average, survival was 55.1 months when death was disease-related, and with regard to histological type, it was longer in papillary carcinoma than in the follicular variant, and longest of all in occult sclerosing carcinoma. Survival was greatest in patients with tumors less than 2 cm in diameter, characterized by the absence of extraglandular spread and by lymph node metastasis.