1,721,315 research outputs found
Updates on mechanism of action and clinical efficacy of risedronate in osteoporosis
Full text linkRisedronate is a heterocyclic orally active aminobisphosphonate and it belongs to the bisphosphonate category: these drugs are powerful bone resorption inhibitors, thanks to their affinity for hydroxyapatite crystals at bone mineral matrix level and to their inhibiting effects on osteoclast activity, using the ability of inhibiting enzyme FPPS. Recent observations have reported that risedronate can decrease resorption entity, not only of the trabecular bone, but also of the cortical bone, modifying therefore the (bone compact) thickness and the cortical porosity entity, which is largely responsible of femoral fracture especially among elderly patients. Various controlled studies have proved the efficacy of risedronate in reducing fragility fracture risk significantly. In particular, it is able to lower in a very significant way the incidence of vertebral, non-vertebral and femoral fractures, with precocity of effects after only six months of therapy. The extension of protocols, moreover, has marked its efficacy even after seven years of treatment. Under the metabolic profile, these studies have also shown that risedronate activity can reduce bone resorption markers and increase bone density values at lumbar and femoral level. Results emerged from a group of women aged over 80 are relevant: risedronate has proved capable of decreasing femoral fracture risk. Also in male and steroidal osteoporosis, clinical controlled studies have shown that risedronate is effective in decreasing vertebral fracture incidence. Lastly, tolerability: the main side effects concern the gastrointestinal tract and they are usually rare, of minor entity and can be solved by sospending the treatment. Acute phase reaction is rare, due to risedronate oral administration; it is also valid for osteonecrosis of the jaw and atypical fractures
Usefulness of QUS in follow-up
No full textAt present, there are few studies evaluating the effects of pharmacological treatments on QUS parameters. Some studies, by ourselves and others, reported that QUS parameters at the heel, and particularly the Stiffness, show similar patterns with respect to axial BMD in osteoporosis patients treated with antiresorptive drugs. For example, 4-year therapy with alendronate in osteoporotic women induced an increase in calcaneal Stiffness greater than the least significant change. QUS parameters at phalanxes seem to be less sensitive with respect to those at calcaneus in monitoring the effects of anticatabolic agents. We recently evaluated the effects of the anabolic agent teriparatide [hPTH(1-34)] on QUS parameters and we found that the parameters derived from graphic trace analysis at phalanxes (BTT and FWA) showed divergent patterns. In fact BTT showed a significant decrease whereas FWA showed the opposite pattern after only two months with teriparatide 20 microg daily. If the results are confirmed by further investigations QUS may represent an important non-invasive tool for a more comprehensive investigation of the skeletal effects of therapeutic interventions and particularly the anabolic agents
Methods for measuring whole-body adipose tissue: the usefulness of "total body" X-ray densitometry [Metodi di misura del tessuto adiposo nel corpo intero: utilità della densitometria "total body" a raggi x]
No full text"Total body" densitometry, which was first used to determine total-body mineral content, allows, above all in the most recent X-ray (DXA) version, an accurate study to be made of soft tissues in relation to both their adipose and nonadipose components. In addition to being used for overall evaluations, it is possible to use DXA for regional studies of body tissue distribution, thus allowing obesity to be analysed not only in quantitative but also qualitative or more specifically endocrine-metabolic terms. In comparison to other methods DXA is noninvasive, quick to use, low cost and risk free. Given its high accuracy rate it can also be used to monitor patients with demineralizing pathologies, obesity, thinness due to global and/or district edema receiving dietary and/or pharmacological treatment
Obesity and fracture risk
Full text linkObesity and osteoporosis are two common diseases with an increasing prevalence and a high impact on morbidity and mortality. Obese women have always been considered protected against osteoporosis and osteoporotic fractures. However, several recent studies have challenged the widespread belief that obesity is protective against fracture and have suggested that obesity is a risk factor for certain fractures. Fat and bone are linked by many pathways, which ultimately serve the function of providing a skeleton appropriate to the mass of adipose tissue it is carrying. Leptin, adiponectin, adipocytic estrogens and insulin/amylin are involved in this connection. However, excessive body fat, and particularly abdominal fat, produces inflammatory cytokines which may stimulate bone resorption and reduce bone strength. This review aimed to examine the literature data on the relationships of BMI and fat mass with factures in adult and elderly subjects. Even though the more recent studies have shown conflicting results, there is growing evidence that obesity, and particularly severe obesity, may be related to an increased risk of fracture at different skeletal sites which is partially independent from BMD. Moreover, the relationship between obesity and fracture appears to be markedly influenced by ethnicity, gender and fat distribution. Even though the incidence and the pathogenesis of fracture in obese individuals has not yet been clearly defined, the growing evidence that obesity may be related to an increased risk of fracture has important public health implications and emphasizes the need to develop effective strategies to reduce fracture risk in obese subject
Perspectives in the treatment and prevention of osteoporosis
No full textOsteoporosis is a chronic skeletal condition characterized by compromised bone strength. This disorder affects a substantial proportion of the elderly population and causes notable morbidity, deterioration in quality of life and mortality due to associated fragility fractures. Over the post two decodes the range of therapeutic options for the treatment of osteoporosis and fracture prevention has increased dramatically with the development of potent antiresorptive and anabolic agents. This review summarizes the effects of existing treatment options and of promising new therapies for osteoporosis prevention and treatment
Anemia in Cardio-Renal Syndrome: clinical impact and pathophysiologic mechanisms
Full text linkAnemia is a disease that is often associated with heart failure (HF) and renal insufficiency (RI). This unfavorable triad of conditions has been called Cardio-Renal-Anemia Syndrome (CRS). The association of HF, RI, and anemia is poorly reported in multicenter clinical trials, so the pathophysiologic mechanisms and treatment options need to be better defined. When CRS patients develop anemia, a "perfect storm" often occurs: HF and RI cause anemia which will worsen the first two conditions. Anemia appears to be the result of complex interactions between cardiac performance, bone marrow homeostasis, renal dysfunction, and various drug side effects. However, neurohormonal and inflammatory activities play a key role in the beginning and progression of the disease. As a consequence, endogenous erythropoietin activity dysfunction with inadequate production and tissue resistance occurs. Despite the advances of therapy in the neurohormonal activation blockade, mortality and hospitalization in HF still remain unacceptably high, suggesting that specific comorbidity treatments could have a significant positive prognostic impact. Anemia should be recognized as one of the novel targets in HF treatment. © 2011 Springer Science+Business Media, LLC
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
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