1,720,975 research outputs found
Hyperprolactinemia after menopause: Diagnosis and management
No full textMost prolactinomas are diagnosed in women of reproductive age and are generally microadenomas. Prolactinomas diagnosed in postmenopausal women are less common and are not usually associated with the typical syndrome induced by prolactin excess, including infertility and oligo-amenorrhea. This implies that the diagnosis of prolactinomas after menopause may be delayed and require greater clinical effort. Limited data are available on the management and prognosis of prolactinomas in postmenopausal women. However, the physiologic decline of prolactin levels during menopause and the lack of fertility concerns, which represent specific indications for medical treatment with dopamine agonists, might require a careful reassessment of therapeutic management in such patients. Postmenopausal women with microprolactinoma may be successfully withdrawn from medical therapy with dopamine agonists, whereas in those with macroprolactinomas greater caution is advisable before dopamine agonists are discontinued, considering the potential, although rare, tumor enlargement. This review focuses on the diagnostic challenges and therapeutic management of prolactinomas in postmenopausal women
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Control of acromegaly in more than 90% of patients after 10 years of pegvisomant therapy: an European referral centre real-life experience
No full textPurpose: Pegvisomant (PEG) efficaciously controls IGF-I excess in acromegaly and possesses a positive impact on glucose metabolism. Data on very prolonged PEG treatment are still limited, therefore, we investigated the effects of 10-years PEG on disease control, maximal tumour diameter (MTD), and metabolic profile in consecutive patients resistant to somatostatin analogues (SRLs) followed in an European referral centre for acromegaly. Methods: Since the 2000s, we collected data on anthropometric, hormonal and metabolic parameters, and MTD of patients receiving PEG. In the current study, we included 45 patients (19 men, 26 women, 46.8 ± 11 years) treated for at least 5 years with PEG mono or combined therapy, analyzing data before, after 5- and 10-years PEG. Results: After10 years, 91% of patients showed full disease control and in 37% a significant decrease in MTD was found. Diabetes prevalence was slightly increased, whereas HbA1c remained stable over the decade. Transaminases remained stable and no case of cutaneous lipohypertrophy was recorded. A different metabolic impact between mono- or combined therapy was found. Patients in monotherapy showed significantly lower fasting glucose (p = 0.01), fasting insulin (p = 0.008), HbA1c (p = 0.007), HOMA-IR (p = 0.001), and significantly higher ISI0 (p = 0.002), whereas patients under combined therapy showed significantly lower total (p = 0.03), and LDL cholesterol (p = 0.007). Acromegaly duration before PEG was inversely related to ΔFG (r = - 0.46, p = 0.03) and ΔFI (r = - 0.54, p = 0.05). Conclusions: PEG is effective and safe in long term. In patients resistant to SRLs, early beginning of PEG allows a wider gluco-insulinemic improvement
The effects of hyperprolactinemia and its control on metabolic diseases
No full textIntroduction: Hyperprolactinaemia has been implicated in the pathogenesis of obesity and glucose intolerance and is reportedly associated with impaired metabolic profile and metabolic syndrome in approximately one third of patients. Area covered: Suppression of dopaminergic tone has been proposed as a potential mechanism responsible for weight gain and metabolic abnormalities in such patients. Dopamine receptor type 2 (D2R) is abundantly expressed on human pancreatic β-cell and adipocytes, suggesting a regulatory role for peripheral dopamine in insulin and adipose functions. Medical treatment with the dopamine-agonists bromocriptine and cabergoline has been shown to significantly improve gluco-insulinemic and lipid profile, also reducing the prevalence of metabolic syndrome. In patients with concomitant hypogonadism, simultaneous correction of both PRL excess and testosterone deficiency is mandatory to improve insulin resistance and metabolic abnormalities. Expert commentary: Hyperprolactinemia promotes metabolic alterations. Control of PRL excess by dopamine agonists is mandatory to induce weight loss and to improve metabolic profile, and replacement treatment for concomitant hypogonadism effectively ameliorates insulin resistance and metabolic syndrome
Resistance to Dopamine Agonists in Pituitary Tumors: Molecular Mechanisms
No full textPituitary neuroendocrine tumors (PitNET) are commonly benign tumors accounting for 10-25% of intracranial tumors. Prolactin-secreting adenomas represent the most predominant type of all PitNET and for this subtype of tumors, the medical therapy relies on the use of dopamine agonists (DAs). DAs yield an excellent therapeutic response in reducing tumor size and hormonal secretion targeting the dopamine receptor type 2 (D2DR) whose higher expression in prolactin-secreting adenomas compared to other PitNET is now well established. Moreover, although DAs therapy does not represent the first-line therapy for other PitNET, off-label use of DAs is considered in PitNET expressing D2DR. Nevertheless, DAs primary or secondary resistance, occurring in a subset of patients, may involve several molecular mechanisms, presently not fully elucidated. Dopamine receptors (DRs) expression is a prerequisite for a proper DA function in PitNET and several molecular events may negatively modify DR membrane expression, through the DRs down-regulation and intracellular trafficking, and DR signal transduction pathway. The current mini-review will summarise the presently known molecular events that underpin the unsuccessful therapy with DAs
Metabolic syndrome in the era of COVID-19 outbreak: impact of lockdown on cardiometabolic health
No full textPurpose: COVID-19 pandemics and cardiometabolic health are mutually interconnected. Chronic metabolic diseases are known risk factors for increased mortality after SARS-CoV-2 infection. In turn, COVID pandemics imposed sudden changes in lifestyle and social isolation with consequent potential cardiometabolic sequelae. The present study aimed at investigating the impact of changes in lifestyle and social life on metabolic profile in hyperprolactinemic or osteoporotic patients without pre-existing cardiometabolic diseases at the time of COVID-19. Methods: The primary study outcome measurement was the prevalence of obesity, arterial hypertension, impaired glucose tolerance (IGT) or diabetes mellitus (DM), dyslipidemia and metabolic syndrome after COVID-19 outbreak. Seventy-four patients (21 men and 53 women, aged 51.8 ± 17.8 years) were admitted to the outpatient clinic of the Neuroendocrine Disease Unit at University “Federico II” of Naples, Italy, as per their routine clinical practice because of tumoral and non-tumoral hyperprolactinemia in 52 patients (70.3%), and osteoporosis/osteopenia in 22 (29.7%). Among female patients, 25 (47.2%) were at menopausal age. Results: At the end of lockdown, prevalence of obesity (from 37.8% to 51.3%, p < 0.0001), dyslipidemia (from 28.4 to 48.6%, p = 0.003) and metabolic syndrome (from 14.9 to 27%, p < 0.0001) significantly increased compared to pre-COVID evaluation. No significant change was found in the prevalence of arterial hypertension and IGT/DM. Conclusion: SARS-CoV-2 outbreak has led to a rapid increase in the prevalence of metabolic syndrome, potentially contributing to the increased COVID-19 related mortality
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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