Multinational evaluation of genetic diversity indicators for the Kunming-Montreal Global Biodiversity Framework.

Under the recently adopted Kunming-Montreal Global Biodiversity Framework, 196 Parties committed to reporting the status of genetic diversity for all species. To facilitate reporting, three genetic diversity indicators were developed, two of which focus on processes contributing to genetic diversity conservation: maintaining genetically distinct populations and ensuring populations are large enough to maintain genetic diversity. The major advantage of these indicators is that they can be estimated with or without DNA-based data. However, demonstrating their feasibility requires addressing the methodological challenges of using data gathered from diverse sources, across diverse taxonomic groups, and for countries of varying socio-economic status and biodiversity levels. Here, we assess the genetic indicators for 919 taxa, representing 5271 populations across nine countries, including megadiverse countries and developing economies. Eighty-three percent of the taxa assessed had data available to calculate at least one indicator. Our results show that although the majority of species maintain most populations, 58% of species have populations too small to maintain genetic diversity. Moreover, genetic indicator values suggest that IUCN Red List status and other initiatives fail to assess genetic status, highlighting the critical importance of genetic indicators.

Obtention of fatty acids and phenolic compounds from Colombian cashew (Anacardium occidentale) nut shells using pyrolysis: towards a sustainable biodiesel production.

Sustainable management of non-edible agricultural residues of cashew nut production is a concern in Colombia. Therefore, this study aimed to study the fatty acid content of a pyrolytic liquid obtained from cashew nut shells (CNSs) from the Vichada region in Colombia. Transesterification of pyrolytic liquid was conducted to obtain biodiesel at the micro-scale as the first approach for this valorization route. Proximal analysis of samples was carried out using advanced analytical techniques (UHPLC-MS and CG-MS) whereas phenolic content and antioxidant activity were determined. The production yield of pyrolytic liquid was 69.15 ± 5.07% weight (wt.), at 550 °C and 2h of pyrolysis and the liquid was rich in fatty acids (∼70% wt.) and long-chain phenols (∼18% wt.). Among the phenolic compounds in liquid, mainly unsaturated C15:4 cardanol was identified (82.1 ± 5.5 mg/g), whereas the antioxidant activity of pyrolytic liquid was 0.714 ± 0.030 TE/g. Moreover, the biodiesel yield was 81% using catalyst sodium methoxide (12% v), and 50 °C and 26 min for the reaction. The obtained biodiesel in the hexane fraction was rich in methyl trans-8-octadecanoate (20.9 % wt.) and methyl palmitate (14.3 % wt.), being the representative compounds in the biodiesel. Therefore, the results indicated that thermal conversion of CNSs for obtaining biodiesel on a one-step process is a suitable strategy for the management of toxic and non-edible cashew residues. Finally, this is the first work of its kind that propose in detail the composition of pyrolytic liquid obtained from Colombian cashew nut residues under the proximate analysis approach and using advanced analytical techniques.

Changes in liver enzymes are associated with changes in insulin resistance, inflammatory biomarkers and leptin in prepubertal children with obesity.

BACKGROUND: Non-alcoholic fatty liver disease is associated with obesity. A subclinical inflammation state, endothelial dysfunction, and parameters related to metabolic syndrome (MetS), have been documented in children with obesity. We aimed to determine the changes that occur in liver enzymes levels in response to the standard treatment of childhood obesity, also assessing any associations with liver enzyme levels, leptin, and markers of insulin resistance (IR), inflammation, and parameters related to MetS in prepubertal children. METHODS: We carried out a longitudinal study in prepubertal children (aged 6-9 years) of both sexes with obesity; a total of 63 participants were recruited. Liver enzymes, C-reactive protein (CRP), interleukin-6, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), soluble intercellular adhesion molecule-1 (sICAM-1), leptin, homeostasis model assessment for IR (HOMA-IR), and parameters related to MetS were measured. RESULTS: After standard treatment for 9 months, children who lowered their standardised body mass index (SDS-BMI) had significantly lower systolic blood pressure (p = 0.0242), diastolic blood pressure (p = 0.0002), HOMA-IR (p = 0.0061), and levels of alanine aminotransferase (ALT) (p = 0.0048), CRP (p = 0.0001), sICAM-1 (p = 0.0460), and IL-6 (p = 0.0438). There was a significant association between the changes that occur with treatment, in the ALT levels, and changes in leptin (p = 0.0096), inflammation biomarkers [CRP (p = 0.0061), IL-6 (p = 0.0337), NLR (p = 0.0458), PLR (p = 0.0134)], and HOMA-IR (p = 0.0322). CONCLUSION: Our results showed that a decrease in ALT levels after the standard treatment for 9 months was associated with favourable changes in IR markers (HOMA-IR) and inflammation (IL-6, CRP, NLR, and PLR).

Chemical composition and bioactive compounds of cashew (Anacardium occidentale) apple juice and bagasse from Colombian varieties.

Cashew nut production generates large amounts of cashew apple as residue. In Colombia, cashew cultivation is increasing together with the concerns on residue management. The objective of this study was to provide the first chemical, physical and thermal decomposition characterization of cashew apple from Colombian varieties harvested in Vichada, Colombia. This characterization was focused to identify the important bioactive and natural compounds that can be further valorized in the formulation of food, nutraceuticals, and pharmacological products. The results obtained in this study are helpful to portray the cashew apple as a potential by-product due to its renewable nature and valuable composition, instead of seeing it just as an agricultural residue. For that, cashew apples of Regional 8315 and Mapiria varieties were studied. The natural juice (cashew apple juice) that was extracted from the cashew apples and the remanent solids (cashew apple bagasse) were separately analyzed. The HPLC analytical technique was used to determine the concentration of bioactive compounds, structural carbohydrates, and soluble sugars that constitute this biomass. Spectrophotometric techniques were used to determine the concentration of tannins, carotenoids, and total polyphenols. Mineral content and antioxidant activity (DPPH and ABTS assays) were determined in the biomass. Also, the thermal decomposition under an inert atmosphere or pyrolysis was performed on cashew apple bagasse. The varieties of cashew apple studied in this work showed similar content of bioactive compounds, total phenolic content, and structural carbohydrates. However, the Mapiria variety showed values slightly higher than the Regional 8315. Regarding cashew apple juice, it is rich in tannins and ascorbic acid with values of 191 mg/100 mL and 70 mg/100 mL, respectively, for Mapiria variety. Additionally, the principal reservoir of bioactive compounds and constitutive carbohydrates was the cashew apple bagasse. About 50 wt.% of it was composed of cellulose and hemicellulose. Also, in the bagasse, the ascorbic acid content was in a range of 180-200 mg/100 g, which is higher than other fruits and vegetables. Moreover, alkaloids were identified in cashew apples. The maximum value of antioxidant activity (DPPH assay: 405 TEs/g) was observed in the bagasse of Mapiria variety. The bagasse thermal decomposition started around 150 °C when the structural carbohydrates and other constitutive substances started to degrade. After thermogravimetric analysis, a remanent of 20% of the initial weight suggested the formation of a rich-carbon solid, which could correspond to biochar. Therefore, the cashew apple harvested in Vichada is a valuable reservoir of a wide range of biomolecules that potentially could be valorized into energy, foods, and pharmacologic applications. Nevertheless, future work is necessary to describe the complex compounds of this residual biomass that are still unknown.

Humans Share More Preferences for Floral Phenotypes With Pollinators Than With Pests.

Studies on the selection of floral traits usually consider pollinators and sometimes herbivores. However, humans also exert selection on floral traits of ornamental plants. We compared the preferences of bumblebees (Bombus terrestris), thrips (Frankliniella occidentalis), and humans for flowers of snapdragon. From a cross of two species, Antirrhinum majus and Antirrhinum linkianum, we selected four Recombinant Inbred Lines (RILs). We characterised scent emission from whole flowers and stamens, pollen content and viability, trichome density, floral shape, size and colour of floral parts. We tested the preferences of bumblebees, thrips, and humans for whole flowers, floral scent bouquets, stamen scent, and individual scent compounds. Humans and bumblebees showed preferences for parental species, whereas thrips preferred RILs. Colour and floral scent, in combination with other floral traits, seem relevant phenotypes for all organisms. Remarkably, visual traits override scent cues for bumblebees, although, scent is an important trait when bumblebees cannot see the flowers, and methyl benzoate was identified as a key attractant for them. The evolutionary trajectory of flowers is the result of multiple floral traits interacting with different organisms with different habits and modes of interaction.

Patients with Axial Spondyloarthritis Show an Altered Flexion/Relaxation Phenomenon.

Axial spondyloarthritis (axSpA) is a chronic rheumatic disease characterized by the presence of inflammatory back pain. In patients with chronic low back pain, the lumbar flexion relaxation phenomenon measured by surface electromyography (sEMG) differs from that in healthy individuals. However, sEMG activity in axSpA patients has not been studied. The purpose of this study was to analyze the flexion relaxation phenomenon in axSpA patients. A study evaluating 39 axSpA patients and 35 healthy controls was conducted. sEMG activity at the erector spinae muscles was measured during lumbar full flexion movements. sEMG activity was compared between axSpA patients and the controls, as well as between active (BASDAI ≥ 4) and non-active (BASDAI < 4) patients. The reliability (using intraclass correlation coefficients (ICC)), criterion validity and discriminant validity using the area Under the curve (AUC) for the inverse flexion/relaxation ratio (1/FRR) were evaluated. Significant differences (p < 0.05) were observed between axSpA patients and the control group in lumbar electric activity, especially during flexion, relaxation, and extension and in FRR and 1/FRR (0.66 ± 0.39 vs. 0.25 ± 0.19, respectively). In addition, significant differences were found between active and non-active but also between non-active and healthy subjects. The sEMG showed good reliability (ICC > 0.8 for 1/FRR) and criterion validity. ROC analysis showed good discriminant validity for axSpA patients (AUC = 0.835) vs. the control group using 1/FRR. An abnormal flexion/relaxation phenomenon exists in axSpA patients compared with controls. sEMG could be an additional objective tool in the evaluation of patient function and disease activity status.

Liver Enzymes Correlate With Metabolic Syndrome, Inflammation, and Endothelial Dysfunction in Prepubertal Children With Obesity.

Background: Metabolic syndrome (MetS) can start in children with obesity at very young ages. Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic component of metabolic syndrome. If left untreated, the clinical course of NAFLD can be progressive and can become chronic if not detected at an early stage. Objective: We aimed to quantify the differences in liver enzymes between prepubertal children with obesity and children with normal weight to determine any associations between them and parameters related to MetS, adipokines, or markers of endothelial dysfunction and inflammation. Methods: This cross-sectional study included 54 prepuberal children with obesity (aged 6-9 years) and 54 children with normal weight, matched by age and sex. Liver enzymes, C-reactive protein (CRP), interleukin-6, soluble intercellular adhesion molecule-1 (sICAM-1), adipokines, and parameters related to metabolic syndrome (MetS) were all measured. Results: Alanine aminotransferase (ALT) levels, serum butyryl cholinesterase (BChE), leptin, CRP, sICAM-1, triglycerides, blood pressure, and homeostasis model assessment for insulin resistance were significantly higher in children with obesity, while Apolipoprotein A-1, HDL-cholesterol, and adiponectin were significantly lower. In the children with obesity group, ALT and BChE levels correlated with anthropometric measurements, insulin resistance, and lipid parameters, leptin, interleukin-6, CRP, and sICAM-1 while BChE levels negatively correlated with adiponectin. Conclusions: Compared to children with normal weight, prepubertal children with obesity had elevated values for liver enzymes, leptin, markers of insulin resistance, inflammation, and endothelial dysfunction, and variables associated with MetS. There was also a correlation between these disorders and liver enzyme levels.

Effects of growth hormone therapy on metabolic parameters, adipokine and endothelial dysfunction in prepuberal children.

AIM: To determine whether non-obese prepubertal children with growth hormone deficiency (GHD) present changes in lipid metabolism, and adipokines, and to assess the short-term effects of growth hormone (GH) treatment on these parameters. METHODS: Prospective observational follow-up and case-control (36 GHD children and 38 healthy children) study lasted for six months. Means of values from groups were compared, control group versus GHD baseline group, and GHD baseline group versus GHD after six months of GH replacement therapy. Lipid profile, glucose, insulin, homeostatic model assessment - insulin resistance (HOMA-IR), leptin, adiponectin and soluble intercellular adhesion molecule-1 (sICAM-1) were all analysed. RESULTS: Growth hormone deficiency children show higher baseline levels of total cholesterol, LDL cholesterol, triglycerides, Apo B and sICAM-1, but lower levels of free fatty acids, insulin and HOMA-IR. After six months of treatment, cholesterol, LDL cholesterol, Apo B, T cholesterol/HDL cholesterol, insulin, HOMA-IR and leptin levels decreased. The changes in insulin and HOMA-IR levels correlated inversely with the changes in HDL cholesterol and Apo A1 levels. A correlation was also observed between the changes in adiponectin levels and the changes in HDL cholesterol and Apo A1 levels. Variations in leptin levels were correlated with changes in triglycerides. CONCLUSION: Prepubertal non-obese GHD children present altered lipid profiles and adipokine levels. Replacement therapy with GH improves these variables.

BIM-23A760 influences key functional endpoints in pituitary adenomas and normal pituitaries: molecular mechanisms underlying the differential response in adenomas.

Chimeric somatostatin/dopamine compounds such as BIM-23A760, an sst2/sst5/D2 receptors-agonist, have emerged as promising new approaches to treat pituitary adenomas. However, information on direct in vitro effects of BIM-23A760 in normal and tumoral pituitaries remains incomplete. The objective of this study was to analyze BIM-23A760 effects on functional parameters (Ca2+ signaling, hormone expression/secretion, cell viability and apoptosis) in pituitary adenomas (n = 74), and to compare with the responses of normal primate and human pituitaries (n = 3-5). Primate and human normal pituitaries exhibited similar sst2/sst5/D2 expression patterns, wherein BIM-23A760 inhibited the expression/secretion of several pituitary hormones (specially GH/PRL), which was accompanied by increased sst2/sst5/D2 expression in primates and decreased Ca2+ concentration in human cells. In tumoral pituitaries, BIM-23A760 also inhibited Ca2+ concentration, hormone secretion/expression and proliferation. However, BIM-23A760 elicited stimulatory effects in a subset of GHomas, ACTHomas and NFPAs in terms of Ca2+ signaling and/or hormone secretion, which was associated with the relative somatostatin/dopamine-receptors levels, especially sst5 and sst5TMD4. The chimeric sst2/sst5/D2 compound BIM-23A760 affects multiple, clinically relevant parameters on pituitary adenomas and may represent a valuable therapeutic tool. The relative ssts/D2 expression profile, particularly sst5 and/or sst5TMD4 levels, might represent useful molecular markers to predict the ultimate response of pituitary adenomas to BIM-23A760.

Octreotide and pasireotide (dis)similarly inhibit pituitary tumor cells in vitro.

Somatostatin analogs (SSA) are the mainstay of pharmacological treatment for pituitary adenomas. However, some patients escape from therapy with octreotide, a somatostatin receptor 2 (sst2)-preferring SSA, and pasireotide, a novel multi-sst-preferring SSA, may help to overcome this problem. It has been proposed that correspondence between sst1-sst5 expression pattern and SSA-binding profile could predict patient's response. To explore the cellular/molecular features associated with octreotide/pasireotide response, we performed a parallel comparison of their in vitro effects, evaluating sst1-sst5 expression, intracellular Ca2+ signaling ([Ca2+]i), hormone secretion and cell viability, in a series of 85 pituitary samples. Somatotropinomas expressed sst5>sst2, yet octreotide reduced [Ca2+]i more efficiently than pasireotide, while both SSA similarly decreased growth hormone release/expression and viability. Corticotropinomas predominantly expressed sst5, but displayed limited response to pasireotide, while octreotide reduced functional endpoints. Non-functioning adenomas preferentially expressed sst3 but, surprisingly, both SSA increased cell viability. Prolactinomas mainly expressed sst1 but were virtually unresponsive to SSA. Finally, both SSA decreased [Ca2+]i in normal pituitaries. In conclusion, both SSA act in vitro on pituitary adenomas exerting both similar and distinct effects; however, no evident correspondence was found with the sst1-sst5 profile. Thus, it seems plausible that additional factors, besides the simple abundance of a given sst, critically influence the SSA response.

Histological Changes in Skeletal Muscle During Death by Drowning: An Experimental Study.

A diagnosis of drowning is a challenge in legal medicine as there is generally a lack of pathognomonic findings indicative of drowning. This article investigates whether the skeletal muscle undergoes structural changes during death by drowning. Eighteen Wistar rats were divided into 3 equal groups according to the cause of death: drowning, exsanguination, and cervical dislocation. Immediately after death, samples of the masseter, sternohyoid, diaphragm, anterior tibial, soleus, and extensor digitorum longus muscles were obtained and examined by light and electron microscopy.In the drowning group, all muscles except the masseter displayed scattered evidence of fiber degeneration, and modified Gomori trichrome staining revealed structural changes in the form of abnormal clumps of red material and ragged red fibers. Under the electron microscope, there was myofibrillar disruption and large masses of abnormal mitochondria. In the exsanguination group, modified Gomori trichrome staining disclosed structural changes and mitochondrial abnormalities were apparent under light microscopy; however, there was no evidence of degeneration. No alterations were observed in the cervical dislocation group.As far as we know, this is the first time that these histological findings are described in death by drowning and are consistent with rhabdomyolysis and intense anoxia of skeletal muscle.

Aggregation Behavior of 6-Isocassine and N-Methyl-6-Isocassine: Insights into the Biological Mode of Action of Lipid Alkaloids.

The aggregation behavior of 6-isocassine and N-methyl-6-isocassine, two piperidin-3-ol alkaloids isolated respectively from the barks of Prosopis nigra and P. affinis, was investigated using a combination of NOE experiments and diffusion measurements in solvents of varying polarity and hydrogen bonding capacity. While the NOE enhancements for N-methyl-6-isocassine are positive, regardless of the solvent, those for 6-isocassine shift from negative to positive when going from chloroform-d to methanol-d(4) solution. In addition, despite the self-diffusion coefficients of both compounds being virtually identical in methanol-d4, N-methyl-6-isocassine diffuses nearly twice as fast as the non-methylated alkaloid in chloroform-d. The changes in rotational and translational dynamics observed between solvents for 6-isocassine suggest that the molecule forms dimeric head-to-head aggregates in non-polar aprotic environments, a behavior that could help explain the biological mode of action that has been proposed for this type of alkaloids.

Métodos de evaluación de las competencias transversales / Assessment methods of generic/transversal competences

El RD 1393/2007 sobre la ordenación de las enseñanzas universitarias oficiales establece que las competencias propuestas tienen que ser evaluables, y la Guía ANECA para la elaboración de los documentos VERIFICA exige garantías de que los titulados hayan adquirido las competencias generales que determina el MECES. Por estos motivos todos los títulos de grado incluyen competencias generales/transversales. En este artículo se presenta la experiencia de una asignatura del grado de Medicina de Córdoba para el aprendizaje y evaluación de competencias transversales (25), las razones que llevaron a plantear este tipo de asignatura, la implicación de profesorado de seis áreas de conocimiento, el diseño de esta asignatura, la metodología de actuación mediante el uso de casos clínicos, el seguimiento del trabajo propuesto y los métodos de evaluación. De las 25 competencias transversales, 6 son evaluadas por profesorado, 12 son evaluadas por profesorado y alumnado y 7 son evaluadas por alumnado. Finalmente, se propone que el aprendizaje y evaluación de las competencias transversales podría realizarse en dos momentos diferentes y en dos formatos distintos. En los primeros cursos de grado, las competencias transversales se abordarían de manera formal y explícita en el contexto de una única asignatura, y de manera implícita durante el desarrollo de otras asignaturas en los últimos cursos del grado

The rule 1393/2007 on the management of official university teaching states that the generic/transversal competences must be evaluated, and the ANECA guide for the preparation of VERIFICA documents requires that the graduates have fulfilled the generic/transversal competences required by the MECES. For these reasons all undergraduate degrees include generic/transversal competences. This article describes: the experience of a subject of Medicine's degree in Cordoba for learning and assessment of generic/transversal competences (25); the reasons behind this subject; the involvement of professors from six areas of knowledge; the design of this subject; the methodology of teaching by the use of clinical cases; follow up of the assignments; and evaluation METHODS: Of the twenty-five generic/transversal competences, six are evaluated by teachers, twelve are assessed by teachers and students and seven are evaluated by estudents. Finally, it is proposed that learning and assessment of generic competences could take place in two different times, and in two different formats. In the first degree courses, generic/transversal competences are addressed explicitly in the context of a single subject, while in the last degree courses it should be done implicitly during the development of other subjects

Somatotropinomas, but not nonfunctioning pituitary adenomas, maintain a functional apoptotic RET/Pit1/ARF/p53 pathway that is blocked by excess GDNF.

Acromegaly is caused by somatotroph cell adenomas (somatotropinomas [ACROs]), which secrete GH. Human and rodent somatotroph cells express the RET receptor. In rodents, when normal somatotrophs are deprived of the RET ligand, GDNF (Glial Cell Derived Neurotrophic Factor), RET is processed intracellularly to induce overexpression of Pit1 [Transcription factor (gene : POUF1) essential for transcription of Pituitary hormones GH, PRL and TSHb], which in turn leads to p19Arf/p53-dependent apoptosis. Our purpose was to ascertain whether human ACROs maintain the RET/Pit1/p14ARF/p53/apoptosis pathway, relative to nonfunctioning pituitary adenomas (NFPAs). Apoptosis in the absence and presence of GDNF was studied in primary cultures of 8 ACROs and 3 NFPAs. Parallel protein extracts were analyzed for expression of RET, Pit1, p19Arf, p53, and phospho-Akt. When GDNF deprived, ACRO cells, but not NFPAs, presented marked level of apoptosis that was prevented in the presence of GDNF. Apoptosis was accompanied by RET processing, Pit1 accumulation, and p14ARF and p53 induction. GDNF prevented all these effects via activation of phospho-AKT. Overexpression of human Pit1 (hPit1) directly induced p19Arf/p53 and apoptosis in a pituitary cell line. Using in silico studies, 2 CCAAT/enhancer binding protein alpha (cEBPα) consensus-binding sites were found to be 100% conserved in mouse, rat, and hPit1 promoters. Deletion of 1 cEBPα site prevented the RET-induced increase in hPit1 promoter expression. TaqMan qRT-PCR (real time RT-PCR) for RET, Pit1, Arf, TP53, GDNF, steroidogenic factor 1, and GH was performed in RNA from whole ACRO and NFPA tumors. ACRO but not NFPA adenomas express RET and Pit1. GDNF expression in the tumors was positively correlated with RET and negatively correlated with p53. In conclusion, ACROs maintain an active RET/Pit1/p14Arf/p53/apoptosis pathway that is inhibited by GDNF. Disruption of GDNF's survival function might constitute a new therapeutic route in acromegaly.

Experimental muscle injury: correlation between ultrasound and histological findings.

INTRODUCTION: In this study we correlated ultrasound findings with histological changes taking place during experimentally induced degeneration-regeneration in rat skeletal muscle. METHODS: Gastrocnemius muscles were injected with mepivacaine, and the progress of the muscle injury was monitored by ultrasound from day 1 to day 20. Muscles were extracted on the same days for histological examination. RESULTS: The degenerative phase was characterized by increased echogenicity in the injured area; thereafter, echogenicity gradually diminished during the regenerative phase, attaining normal levels by 20 days postinjection. By this stage, histological examination revealed that regeneration was complete. The heteroechoic texture observed from day 4 to day 10 appeared to reflect the coexistence of degenerative and regenerative processes. CONCLUSIONS: The results suggest that the degenerative and regenerative phases of muscle injury may be distinguished sonographically through differences in echogenicity and echotexture and, using Doppler ultrasound, differences in the degree of vascularization.

Expression of functional KISS1 and KISS1R system is altered in human pituitary adenomas: evidence for apoptotic action of kisspeptin-10.

CONTEXT: KISS1 was originally identified as a metastasis-suppressor gene able to inhibit tumor progression. KISS1 gene products, the kisspeptins, bind to a G-protein-coupled receptor (KISS1R, formerly GPR54), which is highly expressed in placenta, pituitary, and pancreas, whereas KISS1 mRNA is mainly expressed in placenta, hypothalamus, striatum, and pituitary. OBJECTIVE AND DESIGN: KISS1/KISS1R pituitary expression profile, coupled to their anti-tumoral capacities, led us to hypothesize that this system may be involved in the biology of pituitary tumors. To explore this notion, expression levels of KISS1R and KISS1 were evaluated in normal and adenomatous pituitaries. Additionally, functionality of this system was assessed by treating dispersed pituitary adenoma cells in primary culture with kisspeptin-10 and evaluating intracellular calcium kinetics and apoptotic rate. RESULTS: Both KISS1 and KISS1R were expressed in normal pituitary, whereas this simultaneous expression was frequently lost in pituitary tumors, where diverse patterns of KISS1/KISS1R expression were observed that differed among distinct types of pituitary adenomas. Measurement of calcium kinetics revealed that kisspeptin-10 elicits a remarkable increase in [Ca(2+)](i) in individual cells from four out of the five GH-producing adenomas studied, whereas cells derived from non-functioning pituitary adenomas (NFPA, n=45) did not respond. In contrast, kisspeptin-10 treatment increased the apoptotic rate in cells derived from both GH-producing and NFPA. CONCLUSIONS: These results provide primary evidence that KISS1 and KISS1R expression can be differentially lost in pituitary tumor subtypes, where this system can exert functional, proapoptotic actions, and thereby offer novel insights to investigate the biology and therapeutic options to treat these tumors.

Antagonism between Ghrelin / GH secretagogues and somatostatin inarcuate and periventricular nuclei inprepubertal female rats

Combined growth hormone-releasing hormone (GHRH) and growth hormone secretogogues (GHS) have been used alone or in combination with somatostatin (SRIF) to study the pituitary growth hormone (GH) reserve in adults with GH deficiency, but not in children, owing to the possible adverse effects of these treatments. The study aimed to assess the response of the arcuate and periventricular hypothalamic nuclei, using Fos protein as a marker of neuron activity, and to compare that response with the GH response to different stimuli in the presence or absence of SRIF in prepubertal female rats. Rats received the following intraperitoneal stimuli: GHRH (1?g/kg), GHRP-6 (1 ?g/kg), ghrelin (1 ?g/kg), and GHRH combined with either GHRP-6 or ghrelin, with or without SRIF pretreatment 90 minutes prior to stimulus. The animals were decapitated at different intervals; trunk blood was obtained for the measurement of GH levels using a radioimmunoassay technique, and hypothalamic sections were processed for immunochemical determination of Fos protein expression. In the arcuate nucleus, except for GHRP-6 all stimuli increased Fos protein activity in the absence of SRIF pretreatment; the same effect was achieved by pretreatment with SRIF, although this pretreatment prevented the increase in neuronal activity following all stimuli, except that with GHRH + GHRP-6. In the periventricular nucleus, stimulus with GHRH, GHRP-6, ghrelin and GHRH+ghrelin caused a decline in Fos protein expression in the absence of SRIF, whereas SRIF pretreatment prompted a decrease in Fos protein expression that was counteracted by GHRP6 and GHRH + ghrelin. Peak serum GH values were recorded 15 minutes after the administration of GHRH+ghrelin and GHRH + GHRP-6. SRIH pretreatment inhibited GH release, with a subsequent «escape» and lack of response to stimulation which lasted at least 30 minutes, except following the administration of GHRH. The results suggest that all these actions may be due to functional antagonism between ghrelin/ GH secretagogues and somatostatin (AU)

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Rab18 is reduced in pituitary tumors causing acromegaly and its overexpression reverts growth hormone hypersecretion.

CONTEXT: Rab proteins regulate the sequential steps of intracellular membrane transport. Alterations of these GTPases and their associated proteins are emerging as the underlying cause for several human diseases involving dysregulated secretory activities. OBJECTIVE: Herein we investigated the role of Rab18, which negatively regulates hormone secretion by interacting with secretory granules, in relation to the altered functioning of tumoral pituitary somatotropes causing acromegaly. PATIENTS: A total of 18 patients diagnosed with pituitary tumors causing acromegaly (nine patients) or nonfunctioning adenomas (nine patients) underwent endoscopic transsphenoidal surgery. Adenomas were subsequently processed to evaluate Rab18 production in relation to GH secretion. RESULTS: We found that somatotropinoma cells are characterized by a high secretory activity concomitantly with a remarkably reduced Rab18 expression (15%) and protein content levels (30%), as compared with cells from nonfunctioning pituitary adenomas derived from patients with normal or reduced GH plasma levels (100%). Furthermore, immunoelectron microscopy revealed that Rab18 association with the surface of GH-containing secretory granules was significantly lower in somatotropes from acromegalies than nonfunctioning pituitary adenomas. Finally, we provide evidence that modulation of Rab18 gene expression can revert substantially the hypersecretory activity of cells because Rab18 overexpression reduced by 40% the capacity of cells from acromegalies to respond to GHRH stimulation. CONCLUSION: These results suggest that molecular alterations affecting individual components of the secretory granule traffic machinery can contribute to maintain a high level of GH in plasma. Accordingly, Rab18 constitutes a valuable target as a diagnostic, prognostic, and/or therapeutic tool for human acromegaly.

Ghrelin is produced by and directly activates corticotrope cells from adrenocorticotropin-secreting adenomas.

CONTEXT: In Cushing's disease, ACTH hypersecretion by pituitary corticotrope adenoma cells and resulting hypercortisolism is accompanied by a severely blunted GH secretory response. Interestingly, in Cushing's disease, ghrelin markedly increases plasma ACTH, whereas its stimulatory action on GH secretion is reduced. Although the reported expression of ghrelin receptors (GHS-R) in corticotrope tumors offers a potential mechanism for ghrelin-induced ACTH hypersecretion, studies on the direct effects of synthetic GH secretagogues on corticotropinoma cells offered contradictory results. OBJECTIVE AND DESIGN: To evaluate the direct action of ghrelin on corticotropinoma cells from two patients with Cushing's disease, we measured its effect on free cytosolic calcium concentration ([Ca(2+)](i)). Additionally, expression of GHS-R and its ligand ghrelin was examined in these cells and in five additional corticotropinomas. RESULTS: Ghrelin (10(-6) m) induced a marked [Ca(2+)](i) increase in 89.5% (case 1; n = 19 cells) and 85% (case 2; n = 13 cells) of corticotropinoma cells. Moreover, RT-PCR showed that expression of GHS-R isoforms is accompanied by that of ghrelin in all seven corticotrope adenomas examined. Importantly, double immunogold electron microscopy revealed that ghrelin is costored within ACTH secretory vesicles in densely granulated adenomatous corticotropes. CONCLUSIONS: These results constitute the first demonstration that ghrelin acts directly on corticotrope tumor cells derived from patients with Cushing's disease. The presence of ghrelin and GHS-R suggests that pituitary ghrelin may play an autocrine/paracrine role in regulating ACTH release in Cushing's disease. Our findings provide a plausible cellular basis for the exaggerated ACTH response to ghrelin in Cushing's disease and suggest novel research strategies to develop medical treatments for this disease.