235 research outputs found
Analisi della struttura genetica di <i>Hediste diversicolor</i> (Polychaeta, Nereididae) nel Mediterraneo occidentale mediante marcatori ISSR
La struttura genetica del polichete Hediste diversicolor del Mediterraneo occidentale è stata studiata utilizzando gli ISSR (Inter Simple Sequence Repeats) come marcatori genetici. Sono stati raccolti 30 individui in ciascuna delle seguenti località : Stagno di Calich (Sardegna N-O), Baia di Figari (Corsica S-O), Migliacciaru (Corsica E), Fiume Morto (Toscana N-O) e Coltano (Toscana N-O). L'MDS applicato alle distanze genetiche individuali ha mostrato elevata diversità tra gli individui, ma non ha messo in evidenza alcuna sottostrutturazione genetica nelle popolazioni. Un forte segnale della divergenza genetica tra le popolazioni è dato dal fatto che il 37% del numero totale di bande rilevato è costituito da bande private, cioè esclusive di una popolazione. La varianza genetica, analizzata mediante AMOVA, è risultata equamente ripartita nelle componenti intra- e inter-popolazione (rispettivamente 46.9% e 53.1%). La Φ-statistica ha evidenziato la divergenza genetica tra le popolazioni (Φst = 0.469, P<0.001). La notevole divergenza genetica tra le popolazioni di H. diversicolor è determinata in primo luogo dalla frammentazione naturale dell'habitat che produce isolamento con virtuale assenza di flusso genico tra le popolazioni. L'assenza di sottostrutturazione delle popolazioni, invece, conferma le osservazioni fatte in passato sulla dispersione degli adulti e delle postlarve all'interno dei singoli biotopi
Mitochondrial DNA reveals genetic structuring of <i>Pinna nobilis</i> across the Mediterranean Sea
Pinna nobilis is the largest endemic Mediterranean marine bivalve. During past centuries, various human activities have promoted the regression of its populations. As a consequence of stringent standards of protection, demographic expansions are currently reported in many sites. The aim of this study was to provide the first large broad-scale insight into the genetic variability of P. nobilis in the area that encompasses the western Mediterranean, Ionian Sea, and Adriatic Sea marine ecoregions. To accomplish this objective twenty-five populations from this area were surveyed using two mitochondrial DNA markers (COI and 16S). Our dataset was then merged with those obtained in other studies for the Aegean and Tunisian populations (eastern Mediterranean), and statistical analyses (Bayesian model-based clustering, median-joining network, AMOVA, mismatch distribution, Tajima’s and Fu’s neutrality tests and Bayesian skyline plots) were performed. The results revealed genetic divergence among three distinguishable areas: (1) western Mediterranean and Ionian Sea; (2) Adriatic Sea; and (3) Aegean Sea and Tunisian coastal areas. From a conservational point of view, populations from the three genetically divergent groups found may be considered as different management units
Leptin levels predict the development of left ventricular hypertrophy in a sample of adult men: the Olivetti Heart Study
A higher leptin (LPT) is associated with a greater cardiometabolic risk. Some studies also showed a positive association between LPT and cardiovascular organ damage but no consistent data are available about a predictive role of LPT on cardiac remodelling. Hence, the aim of this study was to evaluate the potential role of LPT on the incidence of left ventricular hypertrophy (LVH) in a sample of adult men
La Biodiversità degli invertebrati marini è sottostimata? Il caso di <i>Ophelia bicornis</i> e <i>Ophelia barquii</i> (Annelida, Polychaeta)
Negli ultimi anni gli studi molecolari condotti su invertebrati marini hanno contribuito fortemente alla valutazione della biodiversità locale mediante la risoluzione di complessi casi di tassonomia. Ophelia bicornis s.l. è un polichete che vive in habitat intertidali sabbiosi delle coste mediterranee ed europee atlantiche, la cui sistematica è ancora in fase di definizione. Un nostro precedente studio effettuato tramite alloenzimi ha suggerito che O. bicornis s.l. è costituita da due specie: O. bicornis s.s. e O. barquii, rispettivamente riconducibili a morfotipi con 6 e 5 paia di nefridiopori. Nel presente lavoro è stata abbinata l'analisi morfologica (conteggio dei nefridiopori) con quella genetica (genotipizzazione tramite ISSR). Sono stati analizzati 6 campioni (n=50) di O. bicornis s.l. provenienti da 3 località sarde e 3 siciliane. I dati morfologici indicano una diversa distribuzione dei due morfotipi, che sono stati rilevati in simpatria, sia in località sarde che siciliane. L'analisi genetica effettuata tramite gli ISSR ripropone la distinzione tra individui con 6 e 5 paia di nefridiopori, confermando la precedente separazione di O. bicornis s.l. in due specie distinte. Il presente lavoro i) rappresenta un'ulteriore conferma del fatto che i livelli di biodiversità negli invertebrati marini sono attualmente sottostimati e ii) pone le basi per uno studio più accurato delle caratteristiche dell'habitat di queste specie
Altered renal sodium handling and risk of incident hypertension : results of the Olivetti Heart Study
Renal tubular sodium (Na) handling plays a key role in blood pressure (BP) regulation. Several cross-sectional studies reported a positive association between higher proximal tubule fractional reabsorption of Na and BP, but no prospective investigation has been reported of this possible association. Hence, the purpose of this study was to estimate the predictive role of renal Na handling on the risk of incident hypertension and the changes in BP occurring in the 8-year follow-up observation of a sample of initially normotensive men (The Olivetti Heart Study). The study included 294 untreated normotensive non-diabetic men with normal renal function examined twice (1994–95 and 2002–04). Renal tubular Na handling was estimated by exogenous lithium clearance. Fractional reabsorption of Na in proximal and distal tubules was calculated and included in the analysis. At baseline, there was no association between BP and either proximal or distal fractional reabsorption of Na. At the end of the 8-year follow-up, direct associations were observed between baseline proximal (but not distal) Na fractional reabsorption and the changes occurred in systolic and diastolic BP over time (+2.79 and +1.53 mmHg, respectively, per 1SD difference in proximal Na-FR; p<0.01). Also multivariable analysis showed a direct association between baseline proximal Na fractional reabsorption and risk of incident hypertension, independently of potential confounders (OR: 1.34, 95%CI:1.06–1.70). The results of this prospective investigation strongly suggest a causal relationship between an enhanced rate of Na reabsorption in the proximal tubule and the risk of incident hypertension in initially normotensive men
A complex species complex: The controversial role of ecology and biogeography in the evolutionary history of Syllis gracilis Grube, 1840 (Annelida, Syllidae)
The cryptic diversity in the polychaete Syllis gracilis Grube, 1840, in the Mediterranean Sea was examined with an integrative morpho-molecular approach. Individuals of S. gracilis were collected at eleven Mediterranean localities to provide an insight into the role of brackish environments in inducing cryptic speciation. The examination of morphological features combined with a molecular genetic analysis based on a partial sequence of the 16S rRNA gene highlighted discrepancies between morphological and molecular diversity. Morphological data allowed to identify a morphotype with short appendages occurring in coralline algae communities and another one with long appendages observed in brackish-water environments and Sabellaria reefs. Multivariate analyses showed that sampling localities were the greatest source of morphological divergence, suggesting that phenotypic plasticity may play a role in local adaptations of S. gracilis populations. Molecular data showed the occurrence of four divergent lineages not corresponding to morphological clusters. Different species delimitation tests gave conflicting results, retrieving, however, at least four separated entities. Some lineages occurred in sympatry and were equally distributed in marine and brackish-water environments, excluding a biogeographic or ecological explanation of the observed pattern and suggesting instead ancient separation between lineages and secondary contact. The co-occurrence of different lineages hindered the identification of the lineage corresponding to S. gracilis sensu stricto. The discrepancy between morphological and molecular diversity suggests that different environmental and biogeographic features may interact in a complex and unpredictable way in shaping diversity patterns. An integrative approach is needed to provide a satisfactory insight on evolutionary processes in marine invertebrates
Tumor induced osteomalacia: a systematic review and individual patient's data analysis
Context: Tumor induced osteomalacia (TIO) is a rare paraneoplastic syndrome, usually caused by small, benign and slow-growing phosphaturic mesenchymal tumors. Clinically, TIO is characterized by renal phosphate leak, causing hypophosphatemia and osteomalacia. This review was performed to assess the clinical characteristics of TIO patients described worldwide so far. Evidence acquisition: On 06/26/2021, a systematic search was performed in Medline, Google Scholar, Google book, and Cochrane Library using the terms: "tumor induced osteomalacia", "oncogenic osteomalacia", "hypophosphatemia". There were no language restrictions. This review was performed according to PRISMA criteria. Evidence results: Overall, 1725 TIO cases were collected. TIO was more frequent in adult men, who showed a higher incidence of fractures compared to TIO women. The TIO causing neoplasms were identified in 1493 patients. The somatostatin receptor-based imaging modalities have the highest sensitivity for the identification of TIO-causing neoplasms. TIO causing neoplasms were equally located in bone and soft tissues; these latter showed a higher prevalence of fractures and deformities. The surgery is the preferred TIO definitive treatment (successful in >90% of patients). Promising non-surgical therapies are treatments with burosumab in TIO patients with elevated Fibroblast Growth Factor-23 levels, and with radiolabeled somatostatin analogs in patients with TIO-causing neoplasm identified by somatostatin receptor-based imaging techniques. Conclusion: TIO occurs preferentially in adult men. The TIO clinical expressiveness is more severe in men as well as in patients with TIO-causing neoplasms located to soft tissues. Treatments with burosumab and with radiolabeled somatostatin analogs are the most promising non-surgical therapies
Circulating leptin is associated with serum uric acid level and its tubular reabsorption in a sample of adult middle-aged men
Purpose
Leptin is associated with cardiovascular risk factors (e.g. hypertension, insulin resistance, kidney disease and excess body weight). Experimental studies showed that leptin might affect serum uric acid, by modulation of the uric acid excretion. However, there are few observational data on the relationship between leptin and uric acid in the general population. Therefore, the aim of the present study was to evaluate the relationship between leptin and uric acid and its excretion in a large middle-aged male general population.
Methods
A sample of 930 adult male individuals (mean age: 52 years) without therapy for high uric acid was included in the analysis (the Olivetti Heart Study).
Results
Uric acid was significantly and positively associated with blood pressure, BMI, waist circumference, insulin resistance, C-reactive protein and leptin (p < 0.01), while inversely with renal function (p = 0.01). The multivariate analysis confirmed the association between leptin and uric acid after adjustment for potential confounders (p < 0.01). After division for adiposity, this trend was confirmed separately for normal weight and excess body weight participants. Moreover, leptin was inversely associated with excretion of uric acid (p < 0.01), also in multivariate analysis (p = 0.03).
Conclusion
The results of this study indicate a positive association between circulating leptin levels and uric acid, independently of potential confounders, both in normal and excess body weight men. Furthermore, an inverse association between leptin and uric acid excretion was detected
Dietary potassium intake and risk of diabetes : a systematic review and meta-analysis of prospective studies
(1) Background: Dietary potassium intake is positively associated with reduction of cardiovascular risk. Several data are available on the relationship between dietary potassium intake, diabetes risk and glucose metabolism, but with inconsistent results. Therefore, we performed a meta-analysis of the prospective studies that explored the effect of dietary potassium intake on the risk of diabetes to overcome these limitations. (2) Methods: A random-effects dose–response meta-analysis was carried out for prospective studies. A potential non-linear relation was investigated using restricted cubic splines. (3) Results: A total of seven prospective studies met the inclusion criteria. Dose–response analysis detected a non-linear relationship between dietary potassium intake and diabetes risk, with significant inverse association starting from 2900 mg/day by questionnaire and between 2000 and 5000 mg/day by urinary excretion. There was high heterogeneity among studies, but no evidence of publication bias was found. (4) Conclusions: The results of this meta-analysis indicate that habitual dietary potassium consumption is associated with risk of diabetes by a non-linear dose–response relationship. The beneficial threshold found supports the campaigns in favour of an increase in dietary potassium intake to reduce the risk of morbidity and mortality. Further studies should be carried out to explore this topic
Increased Microalbuminuria Risk in Male Cigarette Smokers: Results from the “Olivetti Heart Study” after 8 Years Follow-Up
Background/Aims: Association between cigarette smoke and albuminuria (UA) was already demonstrated in cross-sectional studies and in selected population samples (i.e diabetic patients). This study aims to evaluate, prospectively, the relationship between cigarette smoke and UA in a male adult population sample, with basal normal kidney function, participating in the Olivetti Heart Study (OHS). Methods: Among 994 participants, examined in both 1994-95 and 2002-04, were selected those resulted in both visits smokers (n=221) and non-smokers (n=416) and with basal normal kidney function (GFR> 60 mL/min) and basal albumin/creatinine ratio (ACR< 30 mg/g). Results: At baseline, the prevalence of hypertension was 41%, diabetes affected 6.3% and obesity 17% of the whole sample. Smokers showed statistically significant lower levels of systolic (SBP) and diastolic blood pressure (DBP) and BMI (p< 0.001) compared to non-smokers. There were not basal differences in UA, GFR and metabolic profile. However, at follow-up examination, smokers showed a statistically significant increase in SBP and DBP (p< 0.05), but not in GFR and BMI. Moreover, smokers showed a higher risk compared to non-smokers to be in the higher median levels group of UA (OR: 2.17, C.I.95%: 1.51-3.13; p < 0.001), even after correction for major confounding factors. Further adjustment for basal antihypertensive and hypoglycemic treatment did not change these patterns of association. Conclusion: In a selected male adult population sample, cigarette smoke was independently associated with the development of higher levels of albuminuria over time
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