257 research outputs found
The Multimedia Multicasting Problem
No full textWe present the problems associated with multicast communication for multimedia group applications, such as video-conferencing. In particular, when these applications have continuous media I/O components (e.g., audio and video) which must be communicated to a group of receivers, unique problems arise. Perhaps the most fundamental problem is whether feedback should be used in dynamic control; we argue against such reactive control mechanisms and in favor of more proactive mechanisms. We discuss a number of issues, including routing, resource reservation, error control, heterogeneity, and hierarchical coding. Keywords: broadcast, routing, interactive group communication, continuous media, communication network architectures. #################################### Joseph Pasquale may be contacted at [email protected], +1-619-534-2673, +1-619-534-7029 (FAX). George Polyzos may be contacted at [email protected], 1+619-534-3508, +1-619-534-7029 (FAX). Vachaspathi Kompella may be contacted at..
Timing of implant placement after tooth extraction: immediate, immediate-delayed or delayed implants? Review.
No full textThis review is based on a Cochrane systematic review entitled ‘Interventions for replacing missing teeth: dental implants in fresh extraction sockets (immediate, immediate-delayed and delayed implants)' published in The Cochrane Library (see http://www.cochrane.org/ for information). Cochrane systematic reviews are regularly updated to include new research, and in response to comments and criticisms from readers. If you wish to comment on this review, please send your comments to the Cochrane website or to Marco Esposito. The Cochrane Library should be consulted for the most recent version of the review. The results of a Cochrane review can be interpreted differently, depending on people's perspectives and circumstances. Please consider the conclusions presented carefully. They are the opinions of the review authors, and are not necessarily shared by the Cochrane Collaboration.
PURPOSE: To evaluate success, complications, aesthetics and patient satisfaction among immediate, immediate-delayed and delayed implants in post-extractive sockets and whether and when augmentation procedures are necessary and which is the most effective augmentation technique.
MATERIALS AND METHODS: The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched up to the 2nd of June 2010 for randomised controlled clinical trials (RCTs) with a follow-up of at least 1 year in function comparing immediate, immediate-delayed and delayed implants, or comparing various bone augmentation procedures around the inserted implants. Outcome measures were prosthesis and implant failures, complications, patient satisfaction and preference including aesthetics, aesthetics evaluated by a dentist, peri-implant marginal bone level changes, etc. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. The statistical unit of the analysis was the patient. Results were expressed as fixed effects models using mean differences for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CIs).
RESULTS: Fourteen eligible RCTs were identified but only seven trials could be included. Four RCTs evaluated implant placement timing. Two RCTs compared immediate versus delayed implants in 126 patients and found no statistically significant differences. One RCT compared immediate-delayed versus delayed implants in 46 patients. After 2 years, patients in the immediate-delayed group perceived the time to functional loading significantly shorter, were more satisfied and an independent blinded assessor judged the level of the peri-implant marginal mucosa in relation to that of the adjacent teeth as more appropriate (RR = 1.68; 95% CI 1.04 to 2.72). These differences disappeared 5 years after loading, and significantly more complications occurred in the immediate-delayed group (RR = 4.20; 95% CI 1.01 to 17.43). One RCT compared immediate with immediately delayed implants in 16 patients for 2 years and found no differences. Three RCTs evaluated different techniques of bone grafting for implants immediately placed in extraction sockets. No statistically significant differences were observed when evaluating whether autogenous bone is needed in post-extractive sites (one trial with 26 patients) or which was the most effective augmentation technique (two trials with 56 patients).
CONCLUSIONS: There is insufficient evidence to determine the possible advantages or disadvantages of immediate, immediate-delayed or delayed implants, therefore these preliminary conclusions are based on few underpowered trials often judged to be at high risk of bias. There is a suggestion that immediate and immediate-delayed implants may be at a higher risk of implant failure and complications than delayed implants, on the other hand the aesthetic outcome might be better when placing implants just after tooth extraction. There is not enough reliable evidence supporting or refuting the need for augmentation procedures at immediate implants placed in fresh extraction sockets or whether any of the augmentation techniques is superior to the others
Timing of implant placement after tooth extraction: immediate, immediate-delayed or delayed implants? A Cochrane systematic review.
No full textThis review is based on a Cochrane systematic review entitled ‘Interventions for replacing missing teeth: dental implants in fresh extraction sockets (immediate, immediate-delayed and delayed implants)' published in The Cochrane Library (see http://www.cochrane.org/ for information). Cochrane systematic reviews are regularly updated to include new research, and in response to comments and criticisms from readers. If you wish to comment on this review, please send your comments to the Cochrane website or to Marco Esposito. The Cochrane Library should be consulted for the most recent version of the review. The results of a Cochrane review can be interpreted differently, depending on people's perspectives and circumstances. Please consider the conclusions presented carefully. They are the opinions of the review authors, and are not necessarily shared by the Cochrane Collaboration.
PURPOSE:
To evaluate success, complications, aesthetics and patient satisfaction among immediate, immediate-delayed and delayed implants in post-extractive sockets and whether and when augmentation procedures are necessary and which is the most effective augmentation technique.
MATERIALS AND METHODS:
The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched up to the 2nd of June 2010 for randomised controlled clinical trials (RCTs) with a follow-up of at least 1 year in function comparing immediate, immediate-delayed and delayed implants, or comparing various bone augmentation procedures around the inserted implants. Outcome measures were prosthesis and implant failures, complications, patient satisfaction and preference including aesthetics, aesthetics evaluated by a dentist, peri-implant marginal bone level changes, etc. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. The statistical unit of the analysis was the patient. Results were expressed as fixed effects models using mean differences for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CIs).
RESULTS:
Fourteen eligible RCTs were identified but only seven trials could be included. Four RCTs evaluated implant placement timing. Two RCTs compared immediate versus delayed implants in 126 patients and found no statistically significant differences. One RCT compared immediate-delayed versus delayed implants in 46 patients. After 2 years, patients in the immediate-delayed group perceived the time to functional loading significantly shorter, were more satisfied and an independent blinded assessor judged the level of the peri-implant marginal mucosa in relation to that of the adjacent teeth as more appropriate (RR = 1.68; 95% CI 1.04 to 2.72). These differences disappeared 5 years after loading, and significantly more complications occurred in the immediate-delayed group (RR = 4.20; 95% CI 1.01 to 17.43). One RCT compared immediate with immediately delayed implants in 16 patients for 2 years and found no differences. Three RCTs evaluated different techniques of bone grafting for implants immediately placed in extraction sockets. No statistically significant differences were observed when evaluating whether autogenous bone is needed in post-extractive sites (one trial with 26 patients) or which was the most effective augmentation technique (two trials with 56 patients).
CONCLUSIONS:
There is insufficient evidence to determine the possible advantages or disadvantages of immediate, immediate-delayed or delayed implants, therefore these preliminary conclusions are based on few underpowered trials often judged to be at high risk of bias. There is a suggestion that immediate and immediate-delayed implants may be at a higher risk of implant failure and complications than delayed implants, on the other hand the aesthetic outcome might be better when placing implants just after tooth extraction. There is not enough reliable evidence supporting or refuting the need for augmentation procedures at immediate implants placed in fresh extraction sockets or whether any of the augmentation techniques is superior to the others
Trimebutine maleate as a multidimensional-antibacterial agent against functional dyspepsia: A prospective multicenter randomized, double-blind controlled trial
No full text[No Abstract Available]Galenica A.E. Pharmaceutical Company, GreeceJ. Kountouras: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Modest; This work has been financially supported by Galenica A.E. Pharmaceutical Company, Greece. E. Gavalas: None. A. Papaefthymiou: None. I. Tsechelidis: None. S. Polyzos: None. S. Bor: None. M. Diculescu: None. A. Bochenek: None. K. Jadallah: None. J. Rozciecha: None. T. Karakan: None. P. Dabrowski: None. M. Tadeusz: None. Z. Spirchez: None. O. Sezgin: None. M. Gulten: None. N. Farsakh: None. M. Doulberis: None
The performance of the Elecsys® anti-Müllerian hormone assay in predicting extremes of ovarian response to corifollitropin alfa
No full textResearch question: What is the performance of anti-Müllerian hormone (AMH) as measured by the Elecsys® AMH assay in predicting ovarian response in women treated with 150 μg corifollitropin alfa (CFA)? Design: Multicentre, prospective study conducted between December 2015 and April 2018. Women were aged 18–43 years, had regular menstrual bleeding, a body mass index of 17–35 kg/m2 and weighed 60 kg or over. Exclusion criteria: previous oophorectomy, history of ovarian hyperstimulation syndrome, a previous IVF and intracytoplasmic sperm injection cycle producing over 30 follicles measuring 11 mm or wider, basal antral follicle count (AFC) over 20 or polycystic ovarian syndrome. All women were treated with 150 μg CFA followed by recombinant FSH (150–300 IU/day) in a fixed gonadotrophin releasing hormone antagonist protocol. Results: Of the 219 patients enrolled, 22.8% had low ovarian response (three or fewer oocytes), 66.2% had normal response and 11% had high ovarian response (15 or more oocytes). The AMH and AFC presented an area under the curve of 0.883 (95% CI 0.830 to 0.936) and 0.879 (95% CI 0.826 to 0.930), respectively, for low ovarian response; and an AUC of 0.865 (95% CI 0.793 to 0.935) and 0.822 (95% CI 0.734 to 0.909) for high ovarian response. An AMH cut-off of 1.0 ng/ml provided a sensitivity of 92.0% and a specificity of 66.9% in the prediction of low ovarian response; a cut-off of 2.25 ng/ml predicted high ovarian response with a sensitivity of 54.2% and a specificity of 91.8%. Conclusions: The automated Elecsys® AMH assay predicts ovarian response in a CFA antagonist protocol. The best predictors of ovarian response in CFA-treated patients were AMH and AFC
The interplay between lipoproteins, immunity and tryptophan metabolism in atherosclerosis
No full textAtherosclerotic cardiovascular disease (CVD) is the leading cause of mortality worldwide. Atherosclerosis is initiated by the infiltration and accumulation of low-density lipoprotein (LDL) cholesterol in the vascular wall, which activates the innate and adaptive arm of immunity, thereby causing chronic vascular inflammation. The LDL particle is immunogenic, as it not only activates lesional macrophages but is also recognized by T cells, and it elicits B cell-mediated antibody responses. Animal immunization studies suggest that anti-LDL antibodies inhibit atherosclerosis, but concerns exist about the potential proinflammatory role of lesional LDL-reactive T cells. In addition to lipoproteins, amino acids and their metabolites can shape immune cell responses, which has been the subject of intense research in the emerging field of immunometabolism. Current clinical practice guidelines on the prevention of CVD focus on controlling traditional risk factors, such as hypercholesterolemia, which indirectly influence inflammation in the vascular wall. Despite optimal management, however, residual inflammatory risk persists and underscores the need for novel therapeutics that directly target vascular inflammation.In Paper I, we generated mouse strains bearing T cell receptor (TCR) transgenic T cells that react to human LDL. Adoptive transfer of these autoreactive T cells or the intercross of TCR transgenic mice with animals expressing human apolipoprotein B-100 (apoB100) on the LDL receptor−/− (LDLR−/−) background led to reduced vascular inflammation and atherosclerosis. Interestingly, a significant proportion of LDL-reactive T cells differentiated into T follicular helper cells, which helped B cells produce anti-LDL antibodies that formed immune complexes with circulating LDL, thereby reducing plasma cholesterol. In Paper II, we employed dendritic cell (DC) based immunotherapy in an attempt to induce apoB100-specific regulatory T (Treg) cells that can exert anti-inflammatory functions in developing plaques. The vaccine was prepared using bone marrow-derived DCs, which were loaded with apoB100 in the presence of the anti-inflammatory cytokine transforming growth factor beta 2 (TGF-β2). Immunotherapy with these DCs promoted an immune response to apoB100 that favoured the accumulation of Treg cells in atherosclerotic plaques, increased vascular expression of the immunomodulatory enzyme indoleamine 2,3-dioxygenase 1 (IDO1), and ameliorated atherosclerosis. In vitro experiments suggested that the Treg molecule cytotoxic T-lymphocyte–associated antigen-4 (CTLA-4) regulates IDO1 expression in macrophages and vascular cells. In Paper III, we studied the role of IDO1-mediated tryptophan metabolism in atherosclerosis using an inhibitor of IDO1 enzyme, 1-methyl-tryptophan. In vivo and in vitro data indicated that IDO1 regulates vascular inflammation, particularly in smooth muscle cells, and inhibits atherosclerosis possibly via the generation of the metabolite 3-hydroxyanthranilic acid (3-HAA). In Paper IV, we investigated the effects of increased endogenous 3-HAA levels on plasma lipids and atherosclerosis using an inhibitor of the enzyme 3-hydroxyanthranilic acid 3,4-dioxygenase (HAAO). Our data suggested that 3-HAA can lower plasma lipids via inhibition of the sterol regulatory element binding protein-2 (SREBP-2) pathway in hepatocytes and suppress inflammation via inhibition of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in macrophages.The studies included in the present thesis illustrate the intricate interplay between metabolism and immunity in atherosclerosis. It is my belief that our findings will contribute to the development of effective immunomodulatory strategies directly targeting vascular inflammation and addressing the residual inflammatory cardiovascular risk.List of scientific papersI. Gisterå A, Klement ML, Polyzos KA, Mailer RK, Duhlin A, Karlsson MCI, Ketelhuth DFJ, Hansson GK. LDL-reactive T cells regulate plasma cholesterol levels and development of atherosclerosis in humanized hypercholesterolemic mice. Circulation. 2018;138:2513-2526. https://doi.org/10.1161/CIRCULATIONAHA.118.034076 II. Forteza MJ, Polyzos KA, Baumgartner R, Suur BE, Mussbacher M, Johansson DK, Hermansson A, Hansson GK, Ketelhuth DFJ. Activation of the regulatory T-cell/indoleamine 2,3-dioxygenase axis reduces vascular inflammation and atherosclerosis in hyperlipidemic mice. Front Immunol. 2018;9:950. https://doi.org/10.3389/fimmu.2018.00950 III. Polyzos KA, Ovchinnikova O, Berg M, Baumgartner R, Agardh H, Pirault J, Gisterå A, Assinger A, Laguna-Fernandez A, Bäck M, Hansson GK, Ketelhuth DFJ. Inhibition of indoleamine 2,3-dioxygenase promotes vascular inflammation and increases atherosclerosis in Apoe-/- mice. Cardiovasc Res. 2015;106:295-302. https://doi.org/10.1093/cvr/cvv100 IV. Berg M, Polyzos KA, Agardh H, Baumgartner R, Forteza MJ, Kareinen I, Gisterå A, Bottcher G, Hurt-Camejo E, Hansson GK, Ketelhuth DFJ. 3-hydroxyanthranilic acid metabolism controls the hepatic SREBP/lipoprotein axis, inhibits inflammasome activation in macrophages, and decreases atherosclerosis in LDLR-/- mice. [Manuscript]</p
Effect of periodontal disease treatment during pregnancy on preterm birth incidence : a metaanalysis of randomized trials
No full textWe conducted a metaanalysis of randomized controlled trials to determine whether periodontal disease treatment with scaling and/or root planing during pregnancy may reduce preterm birth (PTB) or low birthweight (LBW) infant incidence. Treatment resulted in significantly lower PTB (odds ratio [OR], 0.55; 95% confidence interval [CI], 0.35-0.86; P = .008) and borderline significantly lower LBW (OR, 0.48; 95% CI, 0.23-1.00; P = .049), whereas no difference was found for spontaneous abortion/stillbirth (OR, 0.73; 95% CI, 0.41-1.31; P = .292). Subgroup analysis suggested significant effect of treatment in the absence of history of PTB or LBW (OR, 0.48; 95% CI, 0.29-0.77; P = .003) and less severe periodontal disease as defined by probing depth (OR, 0.49; 95% CI, 0.28-0.87; P = .014) or bleeding on probing site (OR, 0.37; 95% CI, 0.14-0.95; P = .04). If ongoing large and well-designed randomized trials support our results, we might need to reassess current practice or at least be cautious prior to rejecting treatment of periodontal disease with scaling and/or root planing during pregnancy
Association between primary hypothyroidism and metabolic dysfunction-associated steatotic liver disease: an updated meta-analysis
No full textObjective: epidemiological studies have reported an association between primary hypothyroidism and metabolic dysfunction-associated steatotic liver disease (MASLD). However, the magnitude of the risk and whether this risk changes with the severity of MASLD remains uncertain. We performed a meta-analysis of observational studies to quantify the magnitude of the association between primary hypothyroidism and the risk of MASLD. Design: we systematically searched PubMed, Scopus and Web of Science from database inception to 31 January 2024, using predefined keywords to identify observational studies in which MASLD was diagnosed by liver biopsy, imaging or International Classification of Diseases codes. A meta-analysis was performed using random-effects modelling. Results: we identified 24 cross-sectional and 4 longitudinal studies with aggregate data on ∼76.5 million individuals. Primary hypothyroidism (defined as levothyroxine replacement treatment, subclinical hypothyroidism or overt hypothyroidism) was associated with an increased risk of prevalent MASLD (n=24 studies; random-effects OR 1.43, 95% CI 1.23 to 1.66; I 2=89%). Hypothyroidism was also associated with a substantially higher risk of metabolic dysfunction-associated steatohepatitis or advanced fibrosis (n=5 studies; random-effects OR 2.84, 95% CI 2.07 to 3.90; I 2=0%). Meta-analysis of data from four longitudinal studies showed that there was a marginally non-significant association between hypothyroidism and risk of developing MASLD over a median 4.5-year follow-up (random-effects HR 1.39, 95% CI 0.98 to 1.97; I 2=85%). Sensitivity analyses did not modify these findings. The funnel plot did not reveal any significant publication bias. Conclusion: this large and updated meta-analysis provides evidence that primary hypothyroidism is significantly associated with both an increased presence of and histological severity of MASLD.</p
Situation Awareness for Mobile Information Access in Heterogeneous Wireless Networks
No full textThe physical properties of the wireless communication channel imply a sharing
of the limited frequency spectrum among its users. Hence, the available
transportation capacity of wireless links is typically several orders of
magnitude below the capacity of comparable fixed wire connections. In
consequence, mobile users, accessing information by means of a hypertext
system, such as the world wide web, experience undesirable long waiting times
for requested documents.
This thesis' primary objective is the improvement of information access for
mobile users. The approach proposed and discussed in this thesis is partly
based on the assumption that mobile devices are increasingly equipped with
multiple wireless access technologies which facilitate the use of heterogeneous
wireless access networks, differing in parameters such as range, data-rate and
costs. Since some of these networks are deployed with partial coverage, a
user's mobility causes changes of the actual network conditions. Furthermore,
it is assumed that a particular user's scope of interest in information is
time-variant and depending on this user's actual situation. Advances in the
fields of ubiquitous and pervasive computing, particularly the work on context
sensors and observation of user interaction, render it feasible to derive
information on the user's context. In this thesis it is therefore proposed to
employ knowledge about the user's context and behavior, to pro-actively
transmit documents' data, especially during favorable network conditions, over
the wireless communication link, before the user requests the documents.
Human behavior, as observed from outside, is inherently probabilistic, despite
advances in sensor technology. Therefore a probabilistic model for the user
context is formulated. In order to distinguish this model from
non-probabilistic context models and context awareness, the terms ``situation
model'' and ``situation awareness'' are introduced. Since the concept of
situation awareness may as well be utilized for other applications, such as
handover decisions, pro-active computing or future user interfaces to search
engines, the situation model and its discussion is intentionally kept as
general as possible, in order to enable its application to various domains. The
properties of a situation model are analyzed from an information theoretic
viewpoint. This perspective is used later on to illustrate the selection of
suitable sensor data, based on metrics such as conditional entropy and mutual
information.
The task of obtaining and continuously adjusting suitable probabilities for the
model is formally treated as an estimation problem. Several estimators, such as
maximum likelihood (ML), minimum mean square error (MMSE), and maximum
a~posteriori (MAP) are discussed and related to Bayesian estimation.
Particularly, the temporal development of the estimation is investigated and
illustrated.
The concept of situation awareness is then applied to the prefetching of
documents in hypertext systems. A thorough analysis yields qualitative and
quantitative insights into the effects of situation aware prefetching on the
average waiting time and transported data volume. The necessity for the
assumption of a user policy is discussed and an optimum probability threshold
is derived.
The investigation of situation-aware prefetching is further extended by means
of simulations towards various mobile networking scenarios. For this purpose a
novel mobility model is developed and used in conjunction with models for
network topology and traffic to obtain insight into the influence of situation
aware prefetching in both heterogeneous and hybrid wireless networking
scenarios. Results of several simulations are discussed, showing the influence
of parameters such as document probabilities, probability thresholds or level
of network deployment. Simulation results show that significant reductions in
average waiting time are obtainable with the proposed concept.
Finally, implementation aspects of the proposed concept are addressed. A system
architecture for realizing situation-aware mobile information access in a
heterogeneous wireless access infrastructure is proposed. Integration aspects
as well as operational experiences obtained in an experimental testbed are
discussed.
The thesis concludes with a short summary of the achieved results and a brief
outlook to further research inspired by this work
<i>Helicobacter pylori</i>-Related Metabolic Parameters and Premalignant Gastric Mucosa Histological Lesions in Swiss Bariatric Patients
No full textObesity, as a major risk factor of metabolic syndrome (MetS), represents a pandemic, especially in Western societies, and is considered a risk factor for malignancies. Helicobacter pylori (Hp), is a definite carcinogen with global distribution. We aimed to investigate, for the first time in Switzerland, the main gastric mucosa premalignant histological lesions of bariatric patients in correlation with MetS components and Hp Infection (Hp-I). By reviewing retrospectively 94304 patient cases, a total of 116 eligible patients having undergone bariatric surgery were identified. The mean patient age was 48.66 years. Hp(+) patients were 24% (28/116). Presence of gastric mucosa atrophy was documented in 8/28 Hp(+) patients (29%) and (2/88) Hp(−) ones (2%) (p = 0.006). Gastric mucosa intestinal metaplasia was observed in 14/28 (50%) Hp(+) patients versus 3/88 (3.4%) of Hp(-) group (p Hp(+) patients exhibited statistically higher arterial hypertension (p = 0.033). The homeostatic model of assessment insulin resistance was also statistically significantly higher for the Hp(+) group (p p = 0.001). In conclusion, Hp-I is associated with premalignant gastric mucosa histologic lesions and MetS components, including arterial hypertension and IR. Further large-scale prospective studies are required to confirm these findings
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