Individual studies indicate that kidney transplantation is associated with lower mortality and improved quality of life compared with chronic dialysis treatment. We did a systematic review to ...summarize the benefits of transplantation, aiming to identify characteristics associated with especially large or small relative benefit. Results were not pooled because of expected diversity inherent to observational studies. Risk of bias was assessed using the Downs and Black checklist and items related to time‐to‐event analysis techniques. MEDLINE and EMBASE were searched up to February 2010. Cohort studies comparing adult chronic dialysis patients with kidney transplantation recipients for clinical outcomes were selected. We identified 110 eligible studies with a total of 1 922 300 participants. Most studies found significantly lower mortality associated with transplantation, and the relative magnitude of the benefit seemed to increase over time (p < 0.001). Most studies also found that the risk of cardiovascular events was significantly reduced among transplant recipients. Quality of life was significantly and substantially better among transplant recipients. Despite increases in the age and comorbidity of contemporary transplant recipients, the relative benefits of transplantation seem to be increasing over time. These findings validate current attempts to increase the number of people worldwide that benefit from kidney transplantation.
In a systematic review of kidney transplantation compared with dialysis, the authors find that the relative magnitude of the benefit due to transplantation appears to increase over time.
Vitamin D deficiency is associated with cardiovascular disease, the most common cause of mortality in hemodialysis patients. To investigate the relation between blood levels of 25-hydroxyvitamin D ...(25D) and 1,25-dihydroxyvitamin D (1,25D) with hemodialysis outcomes, we measured baseline vitamin D levels in a cross-sectional analysis of 825 consecutive patients from within a prospective cohort of incident US hemodialysis patients. Of these patients, 78% were considered vitamin D deficient with 18% considered severely deficient. Calcium, phosphorus, and parathyroid hormone levels correlated poorly with 25D and 1,25D concentrations. To test the association between baseline vitamin D levels and 90-day mortality, we selected the next 175 consecutive participants who died within 90 days and compared them to the 750 patients who survived in a nested case–control analysis. While low vitamin D levels were associated with increased mortality, significant interaction was noted between vitamin D levels, subsequent active vitamin D therapy, and survival. Compared to patients with the highest 25D or 1,25D levels who received therapy, untreated deficient patients were at significantly increased risk for early mortality. Our study shows that among incident hemodialysis patients, vitamin D deficiency is common, correlates poorly with other components of mineral metabolism and is associated with increased early mortality.
Summary
Objective
Multiple studies have explored the association between serum or plasma vitamin B12 status and obesity, in part because of the relationship between elevated homocysteine ...concentrations and atherosclerosis. This review will address the inconsistent finding of these studies with the objective of determining whether vitamin B12 concentrations are lower in people with higher body mass indices.
Design
MEDLINE and EMBASE were searched to February 2017. Observational studies in general and clinical populations comparing serum/plasma B12 concentrations across groups of different body mass indices were selected. We did network and pairwise meta‐analyses of serum/plasma B12, folate and homocysteine using frequentist techniques. Evidence‐based items potentially indicating risk of bias were assessed.
Results
Of 844 citations, we identified 19 eligible observational studies with 7,055 participants. The overall network, while showing no significant inconsistency between indirect and direct comparisons (P = 0.34), was qualitatively inconsistent. Based on the results of the meta‐regression, in an exploratory sub‐network meta‐analysis where obesity groups were combined, we excluded disease‐specific populations and studies with inadequate description of populations. The direction of the indirect and direct evidence was consistent. The pairwise results from this sub‐network showed lower levels of B12 in people with higher body mass indices: obesity versus control difference in means (MD) −56 pmol L−1 (95% CI −90, −23), obesity versus overweight MD −21 pmol L−1 (95% CI −37, −5) and overweight versus control MD −51 pmol L−1 (95% CI −51, −24). Heterogeneity remained very large for most comparisons, and all the studies carried a high risk for bias.
Conclusions
This review did not establish an inverse association (or J‐curve) between serum or plasma B12 concentrations and body mass index, but the direct pairwise evidence is consistent with an inverse association and supports further investigation.
The history of transgenesis is marked by milestones such as the development of cellular transdifferentiation, recombinant DNA, genetic modification of target cells, and finally, the generation of ...simpler genetically modified organisms (e.g. bacteria and mice). The first transgenic fish was developed in 1984, and since then, continuing technological advancements to improve gene transfer have led to more rapid, accurate, and efficient generation of transgenic animals. Among the established methods are microinjection, electroporation, lipofection, viral vectors, and gene targeting. Here, we review the history of animal transgenesis, with an emphasis on fish, in conjunction with major developments in genetic engineering over the past few decades. Importantly, spermatogonial stem cell modification and transplantation are two common techniques capable of revolutionizing the generation of transgenic fish. Furthermore, we discuss recent progress and future biotechnological prospects of fish transgenesis, which has strong applications for the aquaculture industry. Indeed, some transgenic fish are already available in the current market, validating continued efforts to improve economically important species with biotechnological advancements.
•A brief evolution history of transgenic animals and fish are presented•Primary fish gene delivery techniques were highlighted•Methods for site-specific genomic integration, host-independent transposable elements, and viruses were presented•Spermatogonial-stem-cell transplantation and transgenesis were depicted•And the biotechnological potential of transgenic fish were demonstrated
In the present work we report on the growth, spectroscopy and laser results of diode pumped Pr-doped LiYF(4), LiLuF(4) and LiGdF(4) fluoride, scheelite-type structure crystals. We measured the ...polarisation dependent absorption and emission properties as well as the decay time of the (3)P(0) level. Exploiting the (3)P(2) absorption around 444 nm, we obtained efficient laser emission under GaN laser diode pumping on several transitions from the green to the near infrared wavelength range.
The clinical efficacy and safety of bariatric surgery trials were systematically reviewed. MEDLINE, EMBASE, CENTRAL were searched to February 2009. A basic PubCrawler alert was run until March 2010. ...Trial registries, HTA websites and systematic reviews were searched. Manufacturers were contacted. Randomized trials comparing bariatric surgeries and/or standard care were selected. Evidence-based items potentially indicating risk of bias were assessed. Network meta-analysis was performed using Bayesian techniques. Of 1838 citations, 31 RCTs involving 2619 patients (mean age 30-48 y; mean BMI levels 42-58 kg/m²) met eligibility criteria. As compared with standard care, differences in BMI levels from baseline at year 1 (15 trials; 1103 participants) were as follows: jejunoileal bypass MD: −11.4 kg/m², mini-gastric bypass −11.3 kg/m², biliopancreatic diversion −11.2 kg/m², sleeve gastrectomy −10.1 kg/m², Roux-en-Y gastric bypass −9.0 kg/m², horizontal gastroplasty −5.0 kg/m², vertical banded gastroplasty −6.4 kg/m², and adjustable gastric banding −2.4 kg/m². Bariatric surgery appears efficacious compared to standard care in reducing BMI. Weight losses are greatest with diversionary procedures, intermediate with diversionary/restrictive procedures, and lowest with those that are purely restrictive. Compared with Roux-en-Y gastric bypass, adjustable gastric banding has lower weight loss efficacy, but also leads to fewer serious adverse effects.
Magnesium-based cement is one of the most interesting eco-sustainable alternatives to standard cementitious binders. The reasons for the interest towards this material are twofold: (i) its production ...process, using magnesium silicates, brine or seawater, dramatically reduces CO2 emissions with respect to Portland cement production, and (ii) it is very well suited to applications in radioactive waste encapsulation. In spite of its potential, assessment of the structural properties of its binder phase (magnesium silicate hydrate or M-S-H) is far from complete, especially because of its amorphous character. In this work, a comprehensive structural characterization of M-S-H was obtained using a multi-technique approach, including a detailed solid-state NMR investigation and, in particular, for the first time, quantitative (29)Si solid-state NMR data. M-S-H was prepared through room-temperature hydration of highly reactive MgO and silica fume and was monitored for 28 days. The results clearly evidenced the presence in M-S-H of "chrysotile-like" and "talc-like" sub-nanometric domains, which are approximately in a 1 : 1 molar ratio after long-time hydration. Both these kinds of domains have a high degree of condensation, corresponding to the presence of a small amount of silanols in the tetrahedral sheets. The decisive improvement obtained in the knowledge of M-S-H structure paves the way for tailoring the macroscopic properties of eco-sustainable cements by means of a bottom-up approach.
In recent years, significant progress has been made in organ transplantation, surgical reconstruction, and the use of artificial prostheses to treat the loss or failure of an organ or bone tissue. In ...recent years, considerable attention has been given to carbon nanotubes and collagen composite materials and their applications in the field of tissue engineering due to their minimal foreign-body reactions, an intrinsic antibacterial nature, biocompatibility, biodegradability, and the ability to be molded into various geometries and forms such as porous structures, suitable for cell ingrowth, proliferation, and differentiation. Recently, grafted collagen and some other natural and synthetic polymers with carbon nanotubes have been incorporated to increase the mechanical strength of these composites. Carbon nanotube composites are thus emerging as potential materials for artificial bone and bone regeneration in tissue engineering.
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