Alice Brambilla

Don't spit in the soup: faecal avoidance in foraging wild Alpine ibex, Capra ibex

Faeces are a major vehicle for transmission of parasites among ungulate hosts. Avoiding feeding in proximity to faeces has been shown to be an antiparasitic strategy in experimental settings with domestic and semidomestic ungulates. However, few studies have tested the faecal avoidance hypothesis in wild herbivores. We tested the faecal avoidance hypothesis in a wild population of Alpine ibex by comparing the quantity of faeces in grazed and avoided areas. We counted faecal pellets within a plot around a grazing individual and a plot around a spot actively avoided by the same individual. As predicted, grazed plots had lower densities of faecal pellets than avoided plots. Fresh faeces were avoided more often than medium-aged and old faeces. We found consistent differences in the level of faecal avoidance among individuals, but this was not related to the level of gastrointestinal parasite infection or to the age of the host. Our results suggest that wild Alpine ibex actively avoid foraging near faeces but the antiparasitic value of this behaviour is not evident.

Direct and indirect causal effects of heterozygosity on fitness-related traits in Alpine ibex

Heterozygosity–fitness correlations (HFCs) are a useful tool to investigate the effects of inbreeding in wild populations, but are not informative in distinguishing between direct and indirect effects of heterozygosity on fitness-related traits. We tested HFCs in male Alpine ibex (Capra ibex) in a free-ranging population (which suffered a severe bottleneck at the end of the eighteenth century) and used confirmatory path analysis to disentangle the causal relationships between heterozygosity and fitness-related traits. We tested HFCs in 149 male individuals born between 1985 and 2009. We found that standardized multi-locus heterozygosity (MLH), calculated from 37 microsatellite loci, was related to body mass and horn growth, which are known to be important fitness-related traits, and to faecal egg counts (FECs) of nematode eggs, a proxy of parasite resistance. Then, using confirmatory path analysis, we were able to show that the effect of MLH on horn growth was not direct but mediated by body mass and FEC. HFCs do not necessarily imply direct genetic effects on fitness-related traits, which instead can be mediated by other traits in complex and unexpected ways.

Intra-sexual variability in feeding behaviour of a mountain ungulate: size matters

Many studies comparing the behaviour of individuals of different genders or species showed that animal body mass and forage quality/quantity are key elements of the foraging ecology of herbivores. Since body mass could also influence the animal’s sensitivity to predation risk, its vigilance behaviour should consequently be affected. Alpine ibex (Capra ibex) is characterised by a strong dimorphism among males of different ages, thus representing an ideal case study for testing the Jarman-Bell principle, avoiding possibly misleading effects resulting from the comparison between different species or genders. We analysed the fine-scale foraging behaviour of male ibex in order to assess the effect of body mass and the effects of vegetation quality/quantity on both foraging and vigilance behaviour. Our results showed that smaller males were more selective than larger ones, on account of their lower capability of digesting plant. Smaller males scanned the environment more frequently than larger ones. Male ibex grazed more selectively in sites with high quality forage and their bite rate increased as forage biomass decreased. Vigilance frequency increased with increasing forage biomass as, under these circumstances, ibex are able to prolong anti-predator vigilance while chewing bites that have already been cropped. Our findings highlight the effects of body mass per se on both foraging and anti-predator behaviours in herbivores, thus supporting the Jarman-Bell principle. Foraging can arguably be considered a very flexible behaviour with high evolutionary relevance as it enables herbivores to optimally adjust their total energy intake under varying conditions of food resources.

Assessment of climate change effects on mountain ecosystems through a cross-site analysis in the Alps and Apennines

Mountain ecosystems are sensitive and reliable indicators of climate change. Long-term studies may be extremely useful in assessing the responses of high-elevation ecosystems to climate change and other anthropogenic drivers from a broad ecological perspective. Mountain research sites within the LTER (Long-Term Ecological Research) network are representative of various types of ecosystems and span a wide bioclimatic and elevational range. Here, we present a synthesis and a review of the main results from ecological studies in mountain ecosystems at 20 LTER sites in Italy, Switzerland and Austria covering in most cases more than two decades of observations. We analyzed a set of key climate parameters, such as temperature and snow cover duration, in relation to vascular plant species composition, plant traits, abundance patterns, pedoclimate, nutrient dynamics in soils and water, phenology and composition of freshwater biota. The overall results highlight the rapid response of mountain ecosystems to climate change, with site-specific characteristics and rates. As temperatures increased, vegetation cover in alpine and subalpine summits increased as well. Years with limited snow cover duration caused an increase in soil temperature and microbial biomass during the growing season. Effects on freshwater ecosystems were also observed, in terms of increases in solutes, decreases in nitrates and changes in plankton phenology and benthos communities. This work highlights the importance of comparing and integrating long-term ecological data collected in different ecosystems for a more comprehensive overview of the ecological effects of climate change. Nevertheless, there is a need for (i) adopting co-located monitoring site networks to improve our ability to obtain sound results from cross-site analysis, (ii) carrying out further studies, in particular short-term analyses with fine spatial and temporal resolutions to improve our understanding of responses to extreme events, and (iii) increasing comparability and standardizing protocols across networks to distinguish local patterns from global patterns.

“Brucellupus” in a boy: challenging sle diagnosis in childhood

Systemic Lupus Erythematosus (SLE) is the prototype of systemic autoimmune disorders. Several infectious diseases can mimic autoimmune disorders , eg. Mycobacterium tubercolosis), Parvovirus B19), and Leishmania. Brucella infection has been rarely reported in such differential.

Attività fisica adattata: possibili benefici in bambini e adolescenti obesi

L’obesita infantile e una condizione patologica in continua crescita responsabile di gravi ripercussioni sulla salute degli affetti e in grado di determinare ingenti costi sanitari diretti e indiretti. La prevenzione e il trattamento dell’eccesso ponderale si basano primariamente su una dieta bilanciata e su una costante attivita fisica; i soggetti obesi tuttavia lamentano spesso difficolta fisiche e psichiche a partecipare ai corsi sportivi offerti alla popolazione generale. Il nostro studio ha proposto un programma di attivita controllato di 12 settimane a carattere ricreativo, adattato alle capacita funzionali dei soggetti obesi e basato su una strategia multistep. Un programma di attivita di questo tipo si e dimostrato efficace nel migliorare i parametri metabolici e funzionali dei partecipanti, favorendo la partecipazione all’esercizio e riducendo gli iniziali abbandoni.

Heterozygosity–fitness correlation at the major histocompatibility complex despite low variation in Alpine ibex (Capra ibex)

Crucial for the long‐term survival of wild populations is their ability to fight diseases. Disease outbreaks can lead to severe population size reductions, which makes endangered and reintroduced species especially vulnerable. In vertebrates, the major histocompatibility complex (MHC) plays an important role in determining the immune response. Species that went through severe bottlenecks often show very low levels of genetic diversity at the MHC. Due to the known link between the MHC and immune response, such species are expected to be at particular risk in case of disease outbreaks. However, so far, only few studies have shown that low MHC diversity is correlated with increased disease susceptibility in species after severe bottlenecks. We investigated genetic variation at the MHC and its correlations with disease resistance and other fitness‐related traits in Alpine ibex (Capra ibex), a wild goat species that underwent a strong bottleneck in the last century and that is known to have extremely low genetic variability, both genome‐wide and at the MHC. We studied MHC variation in male ibex of Gran Paradiso National Park, the population used as a source for all postbottleneck reintroductions. We found that individual MHC heterozygosity (based on six microsatellites) was not correlated with genome‐wide neutral heterozygosity. MHC heterozygosity, but not genome‐wide heterozygosity, was positively correlated with resistance to infectious keratoconjunctivitis and with body mass. Our results show that genetic variation at the MHC plays an important role in disease resistance and, hence, should be taken into account for successfully managing species conservation.

Espressione del recettore dell’ormone della crescita nelle malattie infiammatorie croniche

L’artrite idiopatica giovanile (AIG) e una malattia infiammatoria cronica dell’eta pediatrica che colpisce le articolazioni, caratterizzata da alti livelli circolanti di citochine infiammatorie. Poiche un ritardo di crescita e stato riscontrato in bambini affetti da tale patologia, sono stati valutati i fattori implicati in tale ritardo di crescita, analizzando i valori di alcune molecole coinvolte nell’asse GH/IGF, quali l’IGF-I, la GHBP e l’espressione genica del GHR sia al momento della diagnosi che due anni dopo l’inizio del trattamento della malattia. Sono stati quindi arruolati diciotto pazienti (12 maschi e 6 femmine) prepuberi che soddisfacevano i criteri diagnostici per la JIA. In tutti i soggetti sono stati inoltre valutati gli indici infiammatori (VES e PCR) e i valori sierici di IL-6. I risultati ottenuti mostrano come al secondo anno di follow up, l’altezza media e risultata essere aumentata anche se non significativamente, mentre risultavano ridotti gli indici infiammatori e i valori di IL-6. Il dato tuttavia piu interessante e stato l’aumento significativo dell’espressione dell’mRNA del GHR in tutti i pazienti al follow-up rispetto al valore basale e l’aumento significativo della media dei valori di IGF-I confrontata con i livelli all’esordio di malattia. I valori sierici di IGF-I e l’espressione genica del GHR monitorati durante il corso della terapia correlano quindi con il quadro clinico, suggerendo una stretta correlazione tra fattori di crescita e processo infiammatorio.

Cistoadenocarcinoma mucinoso del pancreas in una paziente con sindrome di Turner

La diagnosi di Cistoadenocarcinoma mucinoso del pancreas e, nella maggior parte dei casi, tardiva, in quanto negli stadi precoci di malattia non e presente sintomatologia. Descriviamo qui il caso di una paziente con sindrome di Turner che, dopo riscontro occasionale di massa pancreatica durante ecografia addominale di controllo, ha rifiutato per 18 anni l’intervento di asportazione. Si e potuto percio soltanto seguire ecograficamente l’evoluzione della massa che inizialmente ha mostrato un aumento progressivo delle dimensioni, seguito successivamente da modificazioni in senso maligno dell’aspetto ecografico. Infine e stato riscontrato anche aumento dei valori sierici dei markers tumorali.

ZnT8: può essere un marker precoce di T1DM in bambini con celiachia e/o tireopatie autoimmuni?

Diabete mellito di tipo 1, celiachia e tireopatie autoimmuni sono malattie frequenti in eta pediatrica e spesso associate tra di loro, probabilmente per un comune substrato genetico HLA-correlato. Nella maggior parte dei pazienti pediatrici affetti da T1DM e stata recentemente segnalata la positivita degli autoanticorpi diretti specificatamente contro l’isoforma 8 del trasportatore dello zinco (ZnT8). Lo scopo del nostro studio e stato quello di analizzare la prevalenza e il ruolo degli autoanticorpi anti-ZnT8 in bambini e adolescenti affetti da tireopatie autoimmuni (tiroidite di Hashimoto o malattia di Graves), da malattia celiaca o da entrambe le patologie. I dati pubblicati fino ad ora, infatti, riguardano soltanto la presenza e l’andamento di ZnT8 nelle condizioni di diabete all’esordio e nell’individuazione dei soggetti a rischio fra i familiari dei pazienti diabetici. Non ci sono studi in letteratura relativi alla possibilita di impiego di questo parametro nello screening di pazienti a rischio di diabete tipo 1 perche affetti da altre patologie autoimmuni.