G-protein-coupled receptor kinase 5 polymorphism and Takotsubo cardiomyopathy.

BACKGROUND: Takotsubo cardiomyopathy (TTC) is an increasingly reported clinical syndrome that mimics acute myocardial infarction without obstructive coronary artery disease and is characterized by transient systolic dysfunction of the apical and/or mid-segments of the left ventricle. The syndrome mainly occurs in postmenopausal women with high adrenergic state conditions. Nowadays, the pathophysiology of TTC is not yet known and the possibility of a genetic predisposition is controversial. AIMS: The purpose of this study was to assess the genetic susceptibility to TTC through analysis of the L41Q polymorphism of the G-protein-coupled receptor kinase 5 (GRK5). METHODS AND RESULTS: In a cohort of 20 patients enrolled in two tertiary Italian centers with diagnosis of TTC, accordingly to the commonly accepted Mayo Clinic criteria and in 22 healthy individuals (control) we have evaluated the polymorphism in GRK5 gene. The TTC patients had a mean age of 65 ± 9 years and 19 of 20 were women. The presence of one or two L41 alleles of GRK5 was significantly more frequent in TTC group than in the control group (40 vs. 8%, P = 0.0372). CONCLUSION: In our study, we have found a significant difference in the frequency of GRK5 polymorphism between TTC patients and controls, supporting a genetic predisposition to this cardiac syndrome

Dopamine receptor expression and function in corticotroph pituitary tumors

The role of dopamine agonist treatment in corticotroph pituitary tumors is controversial. The aim of this study was to evaluate D(2) receptor expression in 20 corticotroph pituitary tumors and to correlate it to the in vitro effect of dopamine agonists on ACTH secretion and the in vivo effect of short-term cabergoline treatment on cortisol secretion. D(2) expression was evaluated by receptor-ligand binding, immunohistochemistry, and RT-PCR. A 50% or more decrease in daily urinary cortisol levels was considered a significant clinical response. At receptor-ligand binding, specific binding of [(125)I]epidepride was found in 80% of cases. At immunohistochemistry, specific D(2) immunostaining was found in 75% of cases. D(2) expression was found in 83.3% of cases (D(2long) in 40%, D(2short) in 20%, and both in 40%) by RT-PCR. Significant in vitro inhibition of ACTH secretion was found in 100% of D(2)-positive cases, but not in 100% of D(2)-negative cases by either bromocriptine or cabergoline. A significant in vivo inhibition of cortisol secretion after 3-month cabergoline treatment was found in 60%, although a normalization of cortisol secretion was found in 40% of cases. All cabergoline-responsive cases were associated with D(2) expression, whereas all noncabergoline-responsive cases but one were not associated with D(2) expression. In conclusion, functional D(2) receptors were expressed in approximately 80% of corticotroph pituitary tumors. The effectiveness of cabergoline in normalizing cortisol secretion in 40% of cases supports its therapeutic use in the management of Cushing's disease

Is the meiofauna a good indicator for climate change and anthropogenic impacts?

Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research

Is the meiofauna a good indicator for climate change and anthropogenic impacts?

Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research

Somatostatin, Somatostatin Analogs and Somatostatin Receptor Dynamics in The Biology of Cancer Progression

The pharmacological effects (i.e., inhibition of endocrine secretion and cell proliferation) mediated by the hormone somatostatin (SRIF) are derived from its universal high-affinity binding to five different G proteincoupled receptors (GPCRs), named sst1-5. However, SRIF has a half-life of less than 3 min, whereas the available mono- and bi-specific SRIF preferential analogs show prolonged half-life and increased potency. These compounds may control tumor development, cell proliferation and metastatization by direct actions, including cell division arrest in G0/G1 phase (i.e., induction of cyclin-dependent kinase inhibitor p27(kip1) or p21(Cip1)), induction of apoptosis (i.e., induction of p53 and Bax) and suppression of cell invasion. Along with these direct actions on the biology of cancer progression, in vivo SRIF analogs may also regulate tumor growth through indirect actions, by suppressing the secretion of growth-promoting hormones and growth factors and angiogenesis. Interestingly, when ssts are co-expressed, they may interact forming homo- or heterodimers, also with other GPCRs such as type 2 dopamine receptor and the \u3bc-opioid receptor 1, altering their original pharmacological and functional properties. Dimers can be not only constitutive, but perhaps also ligandpromoted: hence, compounds with high affinity for different ssts isoforms may be used to achieve effects elicited by specific dimers. Future developments in the knowledge of ssts dynamics upon SRIF and SRIF analogs binding in neoplastic tissues may allow the full elucidation of the pathophysiological role of this system and the exploitation of the therapeutic potential of its modulation

Canine pancreatic islet cell tumours secreting insulin-like growth factor type 2: A rare entity

Insulin-like growth factor type II (IGF-II) is the main cause of non-islet cell tumour hypoglycaemia (NICTH) and insulin is thought to be the only factor causing hypoglycaemia in insulinomas. However, two case reports of pancreatic neuroendocrine tumours (PNETs) producing IGF-II have been previously published: a human and a canine patient. In this study, we investigated clinical, histopathological, immunohistochemical and ultrastructural features, and biological behaviour of canine pancreatic IGF-II-omas, a subgroup of PNETs that has not been previously characterized. Case records of 58 dogs with confirmed PNETs and hypoglycaemia were reviewed: six patients were affected by IGF-II-omas. Surgery was performed in all cases and two dogs had metastases. Four patients remained alive and in remission at 370, 440, 560 and 890days post-diagnosis; two died of non-tumour-related causes. IGF-II-omas can be differentiated from insulinomas through hypoinsulinaemia, IGF-II positive and insulin negative immunostaining. The prevalence of this neoplasia is low, accounting for just 6% of PNETs

Biochemical diagnosis and assessment of disease activity in acromegaly: a two-decade experience.

The objective of this study is to assess the secretory pattern of GH after Oral Glucose Tolerance Test (OGTT) or day-curve (DC), in relation with IGF-I and to evaluate the influence of therapy on OGTT. A retrospective analysis in 279 OGTTs performed in 93 acromegalic patients in our unit from January 1988 to December 2005, in 77 patients also DC data were retrived. GH concentration was evaluated by 3 different systems (RIA, IRMA and chemiluminescence assays), and IGF-I by two RIAs. About 12% of OGTT samples were discordant with the baseline, while discordance between nadir and 120th minute was much lower (5%), with all discordant values, except one, near the cut-off lines. Correlation between DC and OGTT data was around 0.99 among all values, discordance rate between nadir and minimum DC was much lower than that with mean DC. In almost 80% of cases there was a complete concordance between OGTT and DC results, and in about 30% IGF-I was discordant with GH. Correlation analysis between IGF-I and GH was highest with DC data and lowest with OGTT baseline (T0). Considering different treatments discrepancy rates between GH and IGF-I were comparable. The best GH parameter is the minimum GH DC, although in the clinical practice the evaluation of OGTT GH in association with IGF-I is the most practical approach. In this case, the basal and T120 GH values can replace multiple sampling. Different treatment modalities do not influence the discordance rate between GH and IGF-I

Effect of environment on growth: auxological and hormonal parameters in African and Italian children

OBJECTIVE: Genetic factors are the most important determinant of final height in developed countries, while in underprivileged countries food intake is crucial. Nutrients, in turn, may importantly affect IGF-IGFBP system which is a critical regulator of growth. The aim of this study was to evaluate the influence of nutrition on IGF system components, as well as on growth by comparing these variables in two selected populations of children living either in poor or in privileged environmental conditions. DESIGN: Height and weight were recorded in 38 normal African children, living in a Catholique Mission in Ivory Coast, and in 93 normal Italian children. IGF-I, IGF-II, IGFBP-3 and ALS were evaluated in all subjects. RESULTS: A normal height in spite of markedly reduced IGF-I, IGFBP-3, ALS and BMI was observed in African children, while the ratio IGF-I/IGFBP-3 was comparable in the two populations. IGF-II was slightly but significantly higher in Africans than in Italians. CONCLUSIONS: In Africans a suboptimal nutritional condition may produce a dramatic reduction of IGF-I, ALS and IGFBP-3, although the final height results minimally affected. This suggests that only a small fraction of the circulating IGF-I is sufficient for growth and confirms what has been reported on liver IGF-I-deficient and ALS knock-out mice. The secular statural trend observed in developed countries is probably due to the increase of IGF-I consequent to the improved nutritional conditions