63 research outputs found
Label Differential Privacy via Aggregation
In many real-world applications, due to recent developments in the privacy
landscape, training data may be aggregated to preserve the privacy of sensitive
training labels. In the learning from label proportions (LLP) framework, the
dataset is partitioned into bags of feature-vectors which are available only
with the sum of the labels per bag. A further restriction, which we call
learning from bag aggregates (LBA) is where instead of individual
feature-vectors, only the (possibly weighted) sum of the feature-vectors per
bag is available. We study whether such aggregation techniques can provide
privacy guarantees under the notion of label differential privacy (label-DP)
previously studied in for e.g. [Chaudhuri-Hsu'11, Ghazi et al.'21, Esfandiari
et al.'22].
It is easily seen that naive LBA and LLP do not provide label-DP. Our main
result however, shows that weighted LBA using iid Gaussian weights with
randomly sampled disjoint -sized bags is in fact -label-DP for any with assuming a lower bound on the linear-mse regression
loss. Further, the -regressor which minimizes the loss on the
aggregated dataset has a loss within -factor of the
optimum on the original dataset w.p. . We
emphasize that no additive label noise is required.
The analogous weighted-LLP does not however admit label-DP. Nevertheless, we
show that if additive noise can be added to any constant fraction of
the instance labels, then the noisy weighted-LLP admits similar label-DP
guarantees without assumptions on the dataset, while preserving the utility of
Lipschitz-bounded neural mse-regression tasks.
Our work is the first to demonstrate that label-DP can be achieved by
randomly weighted aggregation for regression tasks, using no or little additive
noise
A non-randomized prospective study of the blood sparing effect of tranexamic acid in total knee replacement
Background: Several techniques are available to minimize the likelihood of blood transfusion following total knee arthroplasty. Tranexamic acid, an inhibitor of fibrinolysis that blocks the lysine-binding site of plasminogen to fibrin has been reported to reduce intraoperative and postoperative blood loss in patients undergoing total hip and total knee arthroplasties with or without cement. The objective of this study was to assess the efficacy of antifibrinolytic treatment along with other measures like saline adrenaline infusion, no drain, no tourniquet and hypotensive anaesthesia in reducing perioperative blood loss during total knee replacement.Methods: Between January 2011 to January 2016, seventy five consecutive patients who had given written informed consent, undergoing a TKR received tranexamic acid 15 mg/kg body weight intravenous 5 minutes before the skin incision and two doses afterwards (3 and 6 hours after the first dose respectively). TKR was performed in a routine fashion without tourniquet. The saline adrenaline (1:200000) was infiltrated into the skin subcutaneous tissue and capsule before skin incision. A routine closure was carried out without drain. Total blood loss including the hidden blood loss was calculated. All patients were monitored for anemia and postoperative thromboembolic complications.Results: The average total blood loss in study group is 433 ± 148 ml. This is much lesser than what other studies have reported. Mean reduction in hemoglobin levels (gm/dl) between preoperative and postoperative readings is 1.6 gm/dl. One patient had a postoperative DVT which was treated with rivaroxaban 20 mg OD for 6 weeks (oral anticoagulant). Conclusions: Antifibrinolytic agents like tranexamic acid used along with other measures reported in this study produces a significant decrease in blood loss in patients undergoing total knee replacement
A non-interventional, prospective, multicentric real life Indian study to assess safety and effectiveness of un-denatured type 2 collagen in management of osteoarthritis
Background: Osteoarthritis (OA) is the most common musculoskeletal condition affecting the quality of life. Undenatured collagen type II has emerged as one of the promising treatment options in treatment of OA. Despite being available in India, clinical safety and efficacy have not been evaluated. We performed a non-interventional, real-life study to determine its safety and efficacy in Indian population.Methods: A non-interventional, real-life study was performed in patients with OA of knee by 18 orthopaedicians in India. Patients enrolled were followed-up at day 30 (visit 2), day 60 (visit 3) and day 90 (visit 4). Efficacy was assessed by Western Ontario McMaster Osteoarthritis Index (WOMAC) and Visual Analogue scale (VAS) on each visit. Safety was assessed by incidence of suspected adverse events (AEs), and abnormal laboratory parameters.Results: Among 291 enrolled patients 226 patients completed the study. Mean age of the population was 56.2±8.7 years and 53.3% of them were females. In 291 patients included in safety analysis, at least one treatment emergent adverse event (TEAE) was seen in 4.47% patients. None of the AEs were serious or resulted in termination of patient from the study. Nausea (1.37%) and headache (1.03%) were the common AEs. Treatment with undenatured collagen type II was associated with significant reduction in WOMAC score (p<0.0001) and VAS scores (p<0.0001) from baseline to day 90.Conclusions: Undenatured collagen type II is safe and efficacious in Indian patients with OA. This can be considered early in the initial management of OA
Diabetes Causes Dysfunctional Dopamine Neurotransmission Favoring Nigrostriatal Degeneration in Mice
This article also appears in: Special Collection: COVID-19 Resources.[Background]: Numerous studies indicate an association between neurodegenerative and metabolic diseases. Although still a matter of debate, growing evidence from epidemiological and animal studies indicate that preexisting diabetes increases the risk to develop Parkinson's disease. However, the mechanisms of such an association are unknown.[Objectives]: We investigated whether diabetes alters striatal dopamine neurotransmission and assessed the vulnerability of nigrostriatal neurons to neurodegeneration.[Methods]: We used streptozotocinâtreated and genetically diabetic db/db mice. Expression of oxidative stress and nigrostriatal neuronal markers and levels of dopamine and its metabolites were monitored. Dopamine release and uptake were assessed using fastâscan cyclic voltammetry. 6âHydroxydopamine was unilaterally injected into the striatum using stereotaxic surgery. Motor performance was scored using specific tests.[Results]: Diabetes resulted in oxidative stress and decreased levels of dopamine and its metabolites in the striatum. Levels of proteins regulating dopamine release and uptake, including the dopamine transporter, the Girk2 potassium channel, the vesicular monoamine transporter 2, and the presynaptic vesicle protein synaptobrevinâ2, were decreased in diabetic mice. Electrically evoked levels of extracellular dopamine in the striatum were enhanced, and altered dopamine uptake was observed. Striatal microinjections of a subthreshold dose of the neurotoxin 6âhydroxydopamine in diabetic mice, insufficient to cause motor alterations in nondiabetic animals, resulted in motor impairment, higher loss of striatal dopaminergic axons, and decreased neuronal cell bodies in the substantia nigra.[Conclusions]: Our results indicate that diabetes promotes striatal oxidative stress, alters dopamine neurotransmission, and increases vulnerability to neurodegenerative damage leading to motor impairment.Funded by the Spanish Ministries of Economy and Competitiveness (grants BFU2014â52149âR and BFU2017â89336âR to M.V., SAF2016â78207âR and PCINâ2015â098 to R.M., and BFU2017â88393âP to E.D.M.) and of Health, Social Services and Equality (PNSDâ2016I033 to R.M.) and by the RamĂłn Areces Foundation (ref. 172275 to R.M.). Supported by Medical Research Council UK iCASE award (to S.J.C., R.A.), a Biotechnology and Biological Sciences Research Council UK studentship (to S.V.M.), and Parkinson's UK (Jâ1403 to S.J.C.). Partially supported by FEDER funds. CIBERDEM and CIBERNED are initiatives of the Instituto de Salud Carlos III. I.P.T. was supported by a fellowship from the Spanish Ministry of Education, Culture and Sports (FPU 14/04457).Peer reviewe
Analysis of Postoperative Clinical Outcomes in Cervical Myelopathy due to Ossification of Posterior Longitudinal Ligament Involving C2
Study Design Retrospective study. Purpose To investigate the radiological phenotype, patient and surgery-related risk factors influencing postoperative clinical outcome for cervical myelopathy caused by ossification of the posterior longitudinal ligament involving C2 following posterior instrumented laminectomy and fusion. Overview of Literature Ossified posterior longitudinal ligament (OPLL) is caused by ectopic ossification of the posterior longitudinal ligament. It can cause neurological impairment and severe disability. For multilevel cervical OPLL, studies have shown good neurological recovery following cord decompression via either an anterior or posterior approach. There is, however, a lacunae in the literature regarding the outcomes of patients with OPLL extending to C2 and above (C2 [+]). Methods We retrospectively studied 61 patients with C2 (+) OPLL who had posterior instrumented laminectomy and fusion at Ganga Hospital, Coimbatore between July 2011 and January 2021, with a minimum follow-up of 2 years. Data on demographics, clinical outcomes, radiology, and post-surgical outcomes were gathered. Results Among 61 patients, 56 were males and five were females. The OPLL pattern was mixed in 32 cases (52.5%), continuous in 26 cases (42.6%), segmental in two cases (3.3%), and circumscribed in one patient (1.6%). All of our patients showed signs of neurological improvement after a 24-month follow-up. The mean preoperative modified Japanese Orthopaedic Association (mJOA) score was 10.6 (range, 5â11) and the postoperative mJOA score was 15.8 (range, 12â18). The recovery rate was >75% in 27 patients (44.6%), >50% in 32 patients (52.5%), and >25% in two patients (3.3%). The average recovery rate was 71% (range, 33%â100%). The independent risk factor for predicting recovery rate is the preoperative mJOA score. Conclusions In C2 (+) OPLL, posterior instrumented decompression and fusion provide a relatively safe approach and satisfactory results
Striatal Dopamine Transporter Function Is Facilitated by Converging Biology of α-Synuclein and Cholesterol
Striatal dopamine transporters (DAT) powerfully regulate dopamine signaling, and can contribute risk to degeneration in Parkinsonâs disease (PD). DATs can interact with the neuronal protein α-synuclein, which is associated with the etiology and molecular pathology of idiopathic and familial PD. Here, we tested whether DAT function in governing dopamine (DA) uptake and release is modified in a human-α-synuclein-overexpressing (SNCA-OVX) transgenic mouse model of early PD. Using fast-scan cyclic voltammetry (FCV) in ex vivo acute striatal slices to detect DA release, and biochemical assays, we show that several aspects of DAT function are promoted in SNCA-OVX mice. Compared to background control α-synuclein-null mice (Snca-null), the SNCA-OVX mice have elevated DA uptake rates, and more pronounced effects of DAT inhibitors on evoked extracellular DA concentrations ([DA] ) and on short-term plasticity (STP) in DA release, indicating DATs play a greater role in limiting DA release and in driving STP. We found that DAT membrane levels and radioligand binding sites correlated with α-synuclein level. Furthermore, DAT function in Snca-null and SNCA-OVX mice could also be promoted by applying cholesterol, and using Tof-SIMS we found genotype-differences in striatal lipids, with lower striatal cholesterol in SNCA-OVX mice. An inhibitor of cholesterol efflux transporter ABCA1 or a cholesterol chelator in SNCA-OVX mice reduced the effects of DAT-inhibitors on evoked [DA] . Together these data indicate that human α-synuclein in a mouse model of PD promotes striatal DAT function, in a manner supported by extracellular cholesterol, suggesting converging biology of α-synuclein and cholesterol that regulates DAT function and could impact DA function and PD pathophysiology
City Know-How
Human health and planetary health are influenced by city lifestyles, city leadership, and city development. For both, worrying trends are leading to increasing concern and it is imperative that human health and environmental impacts become core foci in urban policy. Changing trajectory will require concerted action; the journal Cities & Health is dedicated to supporting the flow of knowledge, in all directions, to help make this happen. We wish to foster communication between researchers, practitioners, policy-makers, communities, and decision-makers in cities. This is the purpose of the City Know-how section of the journal. âResearch for city practiceâ disseminates lessons from research by explaining key messages for city leaders, communities, and the professions involved in city policy and practice. âCity shortsâ provide glimpses of what is being attempted or achieved âon the groundâ and âcase studiesâ are where you will find evaluations of interventions. Last, âCommentary and debateâ extends conversations we are having to develop and mobilize much needed new thinking. Join in these conversations. In order to strengthen the community of interest, we would like to include many and varied voices, including those from younger practitioners and researchers who are supporting health and health equity in everyday urban lives
Blockade of Fatty Acid Synthase Triggers Significant Apoptosis in Mantle Cell Lymphoma
Fatty acid synthase (FASN), a key player in the de novo synthetic pathway of long-chain fatty acids, has been shown to contribute to the tumorigenesis in various types of solid tumors. We here report that FASN is highly and consistently expressed in mantle cell lymphoma (MCL), an aggressive form of B-cell lymphoid malignancy. Specifically, the expression of FASN was detectable in all four MCL cell lines and 15 tumors examined. In contrast, benign lymphoid tissues and peripheral blood mononuclear cells from normal donors were negative. Treatment of MCL cell lines with orlistat, a FASN inhibitor, resulted in significant apoptosis. Knockdown of FASN expression using siRNA, which also significantly decreased the growth of MCL cells, led to a dramatic decrease in the cyclin D1 level. ÎČ-catenin, which has been previously reported to be upregulated in a subset of MCL tumors, contributed to the high level of FASN in MCL cells, Interesting, siRNA knock-down of FASN in turn down-regulated ÎČ-catenin. In conclusion, our data supports the concept that FASN contributes to the pathogenesis of MCL, by collaborating with ÎČ-catenin. In view of its high and consistent expression in MCL, FASN inhibitors may hold promises for treating MCL
Acute otitis externa: Consensus definition, diagnostic criteria and core outcome set development.
OBJECTIVE: Evidence for the management of acute otitis externa (AOE) is limited, with unclear diagnostic criteria and variably reported outcome measures that may not reflect key stakeholder priorities. We aimed to develop 1) a definition, 2) diagnostic criteria and 3) a core outcome set (COS) for AOE. STUDY DESIGN: COS development according to Core Outcome Measures in Effectiveness Trials (COMET) methodology and parallel consensus selection of diagnostic criteria/definition. SETTING: Stakeholders from the United Kingdom. SUBJECTS AND METHODS: Comprehensive literature review identified candidate items for the COS, definition and diagnostic criteria. Nine individuals with past AOE generated further patient-centred candidate items. Candidate items were rated for importance by patient and professional (ENT doctors, general practitioners, microbiologists, nurses, audiologists) stakeholders in a three-round online Delphi exercise. Consensus items were grouped to form the COS, diagnostic criteria, and definition. RESULTS: Candidate COS items from patients (n = 28) and literature (n = 25) were deduplicated and amalgamated to a final candidate list (n = 46). Patients emphasised quality-of-life and the impact on daily activities/work. Via the Delphi process, stakeholders agreed on 31 candidate items. The final COS covered six outcomes: pain; disease severity; impact on quality-of-life and daily activities; patient satisfaction; treatment-related outcome; and microbiology. 14 candidate diagnostic criteria were identified, 8 reaching inclusion consensus. The final definition for AOE was 'diffuse inflammation of the ear canal skin of less than 6 weeks duration'. CONCLUSION: The development and adoption of a consensus definition, diagnostic criteria and a COS will help to standardise future research in AOE, facilitating meta-analysis. Consulting former patients throughout development highlighted deficiencies in the outcomes adopted previously, in particular concerning the impact of AOE on daily life
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