Discussion The discovery of clozapine has given some hope to hith

Discussion The discovery of clozapine has given some hope to hitherto treatment-resistant psychosis and some other neuropsychiatric disorders. It has been shown to have a better efficacy and side-effect profile over other typical and atypical antipsychotic drugs. The risk of causing agranulocytosis is well established and estimated to be 1%, a reason responsible for its initial withdrawal from the market before its reintroduction. Other life-threatening side effects, such as cardiomyopathies, seizures, diabetes complications, constipation, oesophagitis, have also been reported although infrequently.

The possible mechanisms by which clozapine cause oesophagitis and invariably haematemesis are Inhibitors,research,lifescience,medical unclear but may not be unrelated to its anticholinergic side effect [Tomer et al. 2002; Van Soest et al. 2008], resulting in loss of oesophageal motility, increase in lower sphincter relaxation, and loss of lower oesophageal Inhibitors,research,lifescience,medical tone and pressure. Another mechanism was described by Praharaj and colleagues in which there is impairment of swallowing arising from the effect of clozapine on the

vagal regulation of oesophageal peristaltic movement as well as (apparent) hypersalivation [Praharaj et al. 2006]. Although reported cases of reflux oesophagitis are Inhibitors,research,lifescience,medical few, this is the the most common gastrointestinal complaint as a result of the use of clozapine [Laker and Cookson, 1997; Baker and Chengappa, 1998; Van Veggel et al. 2012]. To the best of our knowledge, this is the first case selleck chem report of a patient in subSaharan Africa without a previous history of upper gastrointestinal disease

such as peptic or duodenal ulcer. In a report Inhibitors,research,lifescience,medical by Laker and Cookson, 4 out of 36 (11%) patients treated with clozapine developed gastrointestinal symptoms suggestive of reflux oesophagitis within 6 weeks of starting Inhibitors,research,lifescience,medical clozapine with endoscopic evidence [Laker and Cookson 1997], 2 of which did not have a prior history of gastrointestinal disease as with this patient. newsletter subscribe Taylor and colleagues reported in a cross-sectional study that patients using clozapine were more likely to be on concomitant acid-suppressant medication compared Dacomitinib with those on those on other atypical antipsychotics [Taylor et al. 2010]. A temporal association between the use of clozapine and gastro-oesophageal reflux disease resulting in later use of acid-suppressant drugs was established in the study by Van Veggel and colleagues [Van Veggel et al. 2012]. Based on the Naranjo probability scale [Naranjo et al. 1981], clozapine is a probable cause of haematemesis in this patient (Naranjo probability score of 6). The evidence in support of this includes lack of prior history suggestive of a gastrointestinal disease, seizure or further haematemesis following discontinuation of clozapine. Furthermore, the patient was only on clozapine at the time of occurrence of the episodes of haematemesis.

However, a

series of cases of agranulocytosis5 led to a d

However, a

series of cases of agranulocytosis5 led to a delay in the further development of clozapine in the US. Based on a large RCT with prospective validation of treatment refractoriness demonstrating clozapine’s superiority over chlorpromazine in refractory schizophrenia,6 the FDA approved clozapine with the narrow indication for treatment resistant patients in 1990. Since then, clozapine’s singular role Inhibitors,research,lifescience,medical in treatment-refractory patients with schizophrenia has been confirmed7 and its role in the management of suicidality has also been established.8 Nevertheless, recent meta-analyses“ did not uniformly confirm clozapine’s superiority over other antipsychotics in schizophrenia. Again, several design issues need to be considered

when evaluating this inconsistency, including inappropriately low doses of clozapine9, as well as the lack of selection for truly resistant patients. Attention to first-episode schizophrenia Beginning in the Inhibitors,research,lifescience,medical mid 1980s increased attention to first episode patients seemed warranted to evaluate treatment outcomes that are unconfounded Inhibitors,research,lifescience,medical by the effects of prior treatment, multiple relapses, and chronic illness.11-13 Studies revealed cognitive and psychosocial deficits that were present at illness onset,14 a long duration of untreated psychosis prior to first mental health contact,15 increased sensitivity to medication side effects,16 but also a better treatment response

Inhibitors,research,lifescience,medical compared with more chronically ill patients.17 Exploring biological heterogeneity and treatment response at this phase has become an important focus. In addition, as part of the move toward the early treatment of schizophrenia, and the response to new FDA incentives, the selleck Bortezomib efficacy of antipsychotics has also demonstrated in adolescents with schizophrenia.18 In Inhibitors,research,lifescience,medical adolescents, appropriate selection criteria and trial design considerations are also critical. Comparative efficacy and effectiveness first-generation Cilengitide and second-generation antipsychotics With the Pacritinib Sigma introduction of second-generation antipsychotics, there were observations of lower extrapyramidal side-effect burden and tardive dyskinesia risk and expectations of superior efficacy for positive, negative, and cognitive symptoms.19 Initial efficacy studies seemed to confirm the superiority of second-generation antipsychotics, but the comparator consisted predominantly of haloperidol, used at moderate to high doses and often without anticholinergic cotreatment, which made early treatment discontinuation and secondary negative symptoms more likely in haloperidol treated patients.

g Alternaria alternate, Penicillium notatum, Aspergillus fumiga

g. Alternaria alternate, Penicillium notatum, Aspergillus fumigatus, and Cladosporium), dust mites, cockroaches, and animal dander.11 The considerable

role of aeroallergens as risk factors for allergic disorders was shown in 141 asthmatic patients in our study, which is in accordance with a similar study on 151 asthmatic patients in Saudi Arabia.16 Also, 23.6% of our allergic patients had sensitivity to weeds, which is comparable Inhibitors,research,lifescience,medical to a prevalence rate of 21% reported by a study in Zanjan (Iran).17 Among our asthmatic patients, positive SPT results for trees, weeds, and grasses were selleck closely similar to the results reported by Farhoudi et al.18 and Movahedi and Moin19 in Iran. Fereidouni et al.20 reported that weeds (81%) and grasses (62%) were the most prevalent allergens in 311 patients Inhibitors,research,lifescience,medical with allergic rhinitis. In our asthmatic patients, sensitivity to house dust mites (DP and DF) was 21% and 25%, respectively, which is parallel to the findings by Ceylan et al.15 This resemblance

could be due to the similar geographical characteristics of the two countries. Our results on the sensitivity to mites and trees are highly in agreement with the findings of Safari et al.21 insofar as they Inhibitors,research,lifescience,medical reported prevalence rates of 27.3% and 27.2% among patients sensitive to mites and trees respectively; nevertheless, the findings of our two studies are not consistent vis-à-vis the percentages of patients sensitive to grasses (9%) and cockroaches (27.2%). As was confirmed in our study, pollen levels are usually higher in spring and lower in autumn.22 Accordingly,

there are various manifestations of allergic symptoms in different seasons. selleck chemicals Cabozantinib Sensitization to the pollens of trees, grasses, and weeds Inhibitors,research,lifescience,medical is higher in spring, and sensitization to house dust mites is elevated in winter for DF and in summer for DP. In contrast, Akarcay et al.23 revealed a significant prevalence of sensitization to pollens and house dust mites, both in spring. Overall, the highest prevalence of asthmatic Inhibitors,research,lifescience,medical and allergic rhinitis patients suffering from all allergens (aero and food allergens) is seen in winter. It is thought that DF is more frequent in dry Drug_discovery climates, whereas DP is more prevalent in humid climates.23 Cat fur allergen induces rapid respiratory symptoms in individuals sensitized to cats.16 Sensitivity to cat fur allergen was found in 13% of our asthmatic patients. Studies in Iran18 and Spain24 have reported the prevalence rates of 15% and 15.5%, respectively, but studies in Baltimore25and Saudi Arabia16 have reported much higher frequencies. It seems that this difference is due to the genetic factors or lower exposure to cats in the Iranian population. Sensitivity to cat fur was found in 23% of our patients with allergic rhinitis, which is comparable to a study from South Africa.

The corpora cavernosa remain well supplied with oxygenated blood

The corpora cavernosa remain well supplied with oxygenated blood and penile tissues remain undamaged. Low-flow priapism is a urological emergency. In adults it occurs most frequently in men in their third and fourth decade. The most common risk factors are pharmacological in adults and haematological disorders in children (although in 40–50% of

all cases no cause is found) [Oweis, 2001; Sharma and Fleisher, 2009; Sood et al. 2008]. Several drugs have been associated with priapism. Some drugs commonly used in the management of cardiovascular and urological symptoms like prazosin, tamsulosin and doxazosin are α-adrenergic receptor antagonists [Spagnul et al. 2011]. Priapism is also Inhibitors,research,lifescience,medical a documented side effect of trazadone, an antidepressant

with Inhibitors,research,lifescience,medical α-adrenergic antagonist properties [Abber et al. 1987]. Anticoagulant medication, including warfarin and intravenous heparin, some antihypertensives such as nifedipine, β blockers such as selleck chemicals llc labetalol, corticosteroids, oral hypoglycaemic agents (tolbutamide) and other conditions such as pelvic trauma and pelvic tumours which may be associated with hyperviscosity states such as various haematological disorders and metabolic disorders (e.g. amyloidosis) can increase the risk of priapism [Brichart et al. 2008; Lapan et al. 1980]. Literature review It is estimated that between Inhibitors,research,lifescience,medical 15% and 26% of priapism cases are linked to the use of antipsychotic medication [Sharma and Fleisher, 2009], via α1- and α2-antagonist activity, which inhibits sympathetic activity [Andersohn et al. 2010; Sood et al. 2008]. It has also recently been proposed that the corpora cavernosa of some men may be more sensitive to the α-blocking effect of antipsychotic Inhibitors,research,lifescience,medical medication [Sharma and Fleisher, 2009]. Although, atypical Inhibitors,research,lifescience,medical antipsychotics were initially thought to be less likely to cause priapism than their typical counterparts,

all have now been associated with this side effect, including risperidone, olanzapine, aripiprazole, clozapine and quetiapine. Choua and colleagues did a literature search on PubMed/Medline (from 1994 to the third week of February 2007) and found 17 reported cases of priapism associated with risperidone, 11 with olanzapine (penile priapism only), 5 associated with quetiapine, 3 with ziprasidone and 2 with aripiprazole (both in Brefeldin_A monotherapy and in combination with other medications) [Choua et al. 2007]. In 2008 Sood and colleagues found 50 reports of priapism associated with atypical antipsychotics up to 2007, out of which 16 were associated with risperidone [Sood et al. 2008]. Building on this work, we searched PubMed and Ovid until 2011 with no time or language restrictions and found an additional 16 case reports of priapism involving risperidone (Table 1). Table 1. Literature review.

With this approach there is a high risk of anterior mitral valve

With this approach there is a high risk of anterior mitral valve leaflet injury, causing severe mitral regurgitation. Transfemoral retrograde approach has been shown to be safer and is now preferred.14–18 Patients are usually placed under general

anesthesia with endotracheal intubation, although sedation and analgesia may be sufficient. After crossing the AV, a balloon aortic valvuloplasty (BAV) is performed using standard techniques in order to pre-dilate the stenotic valve. Simultaneous rapid right ventricular pacing using a temporary selleck chemicals llc pacemaker (usually 180 beats/min), decreasing cardiac output, is Inhibitors,research,lifescience,medical used to stabilize the balloon during the inflation.19 Because of the large profile of the device, many patients with small or diseased iliofemoral arteries are not Inhibitors,research,lifescience,medical eligible for the procedure or are at risk for major vascular complications. An alternative transapical antegrade approach has been proposed; through a left anterolateral minithoracotomy, with the patient under general anesthesia,

the pericardium is opened over the apex. Temporary pacing wires are placed on the left ventricle (LV), the LV apex is punctured, and two pledgeted sutures are placed. A stiff wire is passed to the descending Inhibitors,research,lifescience,medical aorta, and BAV is performed. The percutaneous valve is then deployed. As the number of patients screened for TAVI increases, many are found with absolutely no option

Inhibitors,research,lifescience,medical for peripheral artery access. Therefore, Latsios et al. tested the safety and efficacy of the retrograde, minimally invasive, “transaortic” approach of transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve prosthesis (Medtronic, Minneapolis, MN, USA) as an alternative minimally invasive surgical access route.20 Two patients were carefully selected from a cohort of 580 patients: two women, aged 93 and 84 years, both Inhibitors,research,lifescience,medical with severe peripheral arterial occlusive disease. After a mini-sternotomy the ascending aorta was directly punctured. At the end, the access site was surgically sutured with the pre-positioned sutures. The patients were at all times off-pump and without intra-aortic balloon pump. The authors reported that TAVI was successful in both cases, leading to a fall in the transvalvular gradient with no cases of mortality, stroke, or myocardial infarction. The patients were extubated directly after the procedure, mobilized after 4 days, Batimastat and were inhibitor Bosutinib discharged home after 7 and 9 days thereafter. Hospitalization length was 34 days (patient #1) and 24 days (patient #2). These cases may support the notion that on rare occasions, where due to anatomical reasons transfemoral TAVI is not feasible, a minimally invasive “transaortic” approach, as described, provides an alternative option. This line of results follows the report by Bauernschmitt et al.

One hundred and seventy one (171) fractions of 250 ml each were c

One hundred and seventy one (171) fractions of 250 ml each were collected and combined on the basis of their thin layer chromatography (TLC) profiles to afford eight main fractions: F1 (1-59), F2 (60-122), F3 (123-124),

F4 (125-126), F5 (127-138), F6 (139-149), F7 (150-156) and F8 (157-171). These fractions were tested for their antidermatophytic activities. Fraction F2 () was purified on a silica gel 60 (0.063-, ) column (×) to give glucosterol (28 mg). Fraction F3 () was rechromatographed on a silica gel Inhibitors,research,lifescience,medical 60 (0.063-, ) column giving a mixture of sterols and fatty acids (32 mg). Identification of the Compounds The structure of the isolated compound was established on the basis of spectroscopic analysis (IR, UV, 1H NMR) and by comparison of the data with those reported in literature.6 The mixture of sterols and fatty acids was identified by Gas Chromatography-Mass Spectrometry Inhibitors,research,lifescience,medical (GC-MS) after saponification and methylation of fatty acids.7 The separated compounds were identified by comparisons of their mass spectra to those of compounds

registered in NIST 89 Inhibitors,research,lifescience,medical and Wiley 237 spectral libraries of GC-MS instrument. Micro-organisms The microorganisms used in this study included four strains of dermatophytes, namely: Trichophyton mentagrophytes E1425, Trichophyton terrestre E1501, Microsporum gypseum E1420 and Epidermophyton floccosum E1423 obtained from “Ecole nationale vétérinaire d’Aford” Inhibitors,research,lifescience,medical (France), and one clinical isolate of Microsporum Brefeldin A purchase audouinii characterized in our laboratory. These fungi were grown at room temperature (25±2°C) and maintained on sabouraud dextrose agar (SDA, Biomerieux). In Vitro Antidermatophytic Test The antidermatophytic activities of the crude CH2Cl2-MeOH (1:1 v/v) extract, fractions and pure compound from C. edulis were evaluated using the agar dilution concerning method as reported by Kuiate and co-workers.8 Stock solutions of the test samples (100 mg/ml) were prepared using a 10% solution of dimethylsulfoxide (DMSO, Mehr). From Inhibitors,research,lifescience,medical these stock solutions, dilutions (in melted Sabouraud Dextrose Agar, SDA, Biomerieux) were made to give serial two-fold dilutions with concentrations ranging

from 0.312 to 5 mg/ml. The Petri dishes ( diameters) were filled with samples containing SDA to a final volume AV-951 of 10 ml. The Petri dishes were then inoculated at their centre with a disk ( diameters) cut from the periphery of 10 days-old cultures. Negative control dishes contained a 10% final concentration of DMSO. Griseofulvin was used as a positive control. The test and the negative control Petri dishes were incubated at room temperature for 10 days. The radial growth of each fungus was recorded every day at the same time and the percentages of inhibition were calculated using the following formula: I%=dc-dtdc×100 Where dc was the diameter of colony of negative control culture and dt was the diameter of colony of test culture. Each assay was repeated trice.

Other treatment-related adverse events leading to regorafenib dis

Other treatment-related adverse events leading to regorafenib discontinuation included hypertension, fatigue, thrombocytopenia and diarrhea. Among 25 patients treated at 160 mg dose level, 6 patients permanently

discontinued due to treatment-related adverse events including hand-foot skin reaction, hypertension, fatigue, thrombocytopenia and duodenal ulcer. In efficacy evaluation, 27 evaluable patients achieved 74% disease control rate with partial response in 1 patient (4%) and stable disease in 19 patients (70%). Overall, regorafenib was well tolerated and adverse events were manageable (59). The multi-national phase III CORRECT trial enrolled mCRC patients who Inhibitors,research,lifescience,medical had received all locally-approved Inhibitors,research,lifescience,medical standard therapies and had progressed during or within 3 months after the last standard therapy (10). Patients were randomized in a 2:1 ratio to receive regorafenib

or placebo. 500 patients received regorafenib at 160 mg orally 21 days on 7 days off and 253 patients received placebo. Median OS was 6.4 months in the regorafenib group versus 5.0 months in the placebo group (HR 0.77; 95% CI: 0.64-0.94; one-sided P=0.0052). Similar clinical benefit was observed in patient with colon cancer and rectal. The most common treatment-related Grade 3 or worse adverse events were Inhibitors,research,lifescience,medical hand-foot skin reaction (17%), fatigue (10%), diarrhea (7%), hypertension (7%), and rash or skin desquamation (6%), consistent with that observed in earlier phase trials. These adverse events were mostly manageable with dose reduction or interruption. Conclusion Angiogenesis is now a validated therapeutic target in CRC patients with macroscopic metastases. Recent development added 2 new anti-angiogenic drugs to the CRC Inhibitors,research,lifescience,medical treatment armamentarium and confirmed the advantage of

continuing angiogenic suppression beyond first progression in metastatic CRC patients (60). Evidence so far supports the use of bevacizumab in both first- and second-line treatment of metastatic CRC patients. In comparison, the role of aflibercept Inhibitors,research,lifescience,medical in these settings remains unclear given the comparable efficacy but higher cost compared to bevacizumab. Aflibercept targets a broader set of pro-angiogenic growth factors than bevacizumab, and has the theoretical advantage of more effective angiogenic suppression and overcoming bevacizumab resistance. However, these hypotheses Dacomitinib are yet to be confirmed in clinical studies. As the chemotherapeutic options and supportive care improve, more metastatic CRC patients nowadays have good performance status by the time they exhausted all standard therapy. For them, regorafenib is a welcomed option in addition to participation in clinical trials. Looking back, the overall survival of patients with metastatic CRC has increased several folds when compared to decades ago even though, it seemed, each drug achieved only incremental improvement individually. However, it is clear more novel treatment approaches are needed to continue this trend.

29,30 The results were encouraging to enthusiasts, but neither th

29,30 The results were encouraging to enthusiasts, but neither the diagnosis nor the therapy became accepted practice for an extended period. CSM was not performed in many centres and was considered dangerous selleck product until the relatively benign complications incidence was reported. 19 Syncope recurrence was also considered to be a problem. That it was higher than in atrioventricular block should have been anticipated, as CSS is a form of reflex syncope involving – in every case – some degree of vasodepression. Results in the late 1980s, showing a 9% recurrence with dual chamber pacing and 18% with ventricular

pacing in 5 years gave a realistic picture at the time. 31 This was corroborated by Lopes et al in 2011, 32 using dominantly dual chamber pacing with 10.9% recurrence also in 5 years, but Brignole and Menozzi found 20% in their series over 5 years of follow-up. 33 Furthermore, in relation to current data, these figures are relatively acceptable with ∼20% in sinus node disease in 5.5 years 34 and 25% in 2 years in older vasovagal patients. 35 One randomized trial (RCT) was performed on 60 patients in 1992, with a highly significant benefit of pacing being shown (p < 0.002),

36 with a second RCT by another group in 2007 serving to confirm the earlier results. 37 CSS became fully accepted as having a strong indication for pacing and is classified as a Class 1 indication, level of evidence B in the current ESC Guidelines for Pacing. 1 The mode of pacing is advised

to be dual chamber for all those in sinus rhythm, reserving VVI pacing for those in permanent atrial fibrillation. 1 Recent earlier evidence suggests that, in both CSS and VVS, a positive tilt test implies a less positive outcome, in terms of recurrent syncope (Figure 3), from pacing, 2,38,39 which may be explained by the presence of a more potent vasodepressor component of the reflex. 40 It is in this regard that consideration of overlap between CSS and VVS is most important. Figure 3. Recurrence of syncope according to tilt-test results Figure reproduced with permission of Oxford University Press. From Solari et al. 2 CI = Cardioinhibitory. There is a case to be made for use of tilt-testing in CSS to risk stratify Drug_discovery cardioinhibitory or mixed patients in order to anticipate the likely recurrence of syncope and, perhaps, to go a step further and attempt prophylactic treatment of the vasodepressor component. However, since this treatment is less than satisfactory it may be prudent to await a first recurrence before embarking on therapy. Therapy of vasodepressor CSS Management of vasodepressor CSS has received relatively little attention. 41 Patients are advised to take increased volumes of fluid (2+litres/day) and, if safe, to increase salt consumption toward 6g/day. The principle difficulty in management is the frequent coincidence of hypertension.

In a similar way, studies are needed to understand why most sedat

In a similar way, studies are Temsirolimus msds needed to understand why most sedatives exacerbate disordered breathing during sleep, and to design countermeasures, or even drugs preventing, sleep apnea. As recently stressed by Mignot et al,13 the rapid growth of basic and clinical sleep research promises to lead to new and more targeted pharmacotherapy for sleep disorders. Thus, new drugs for therapeutic application in sleep disorder medicine arc clearly needed. For this purpose, objective assessments of drug effects with polysomnographic recordings, even in the very early phase of development in humans, are mandatory in Inhibitors,research,lifescience,medical a developmental plan for a new sleep-acting compound. In the present

paper, arguments for using sleep as a tool for the development of other drugs acting on the central http://www.selleckchem.com/products/CHIR-258.html nervous system (CNS) will be presented. In the following sections, we will discuss how the relationship between sleep physiology and neurotransmitter function could be used for the development of CNS-acting drugs. REM Inhibitors,research,lifescience,medical sleep pressure as a surrogate marker of a cognitive enhancer acting on cholinergic neurotransmission The cholinergic system is one of the most, important modulatory neurotransmitters in the brain and controls

many activities that depend on selective attention and conscious awareness. Drugs that antagonize muscarinic receptors induce hallucinations and reduce the level of consciousness, while Inhibitors,research,lifescience,medical the nicotinic receptor is implicated in the mode of action of general anesthetics.14 In degenerative diseases of the brain, such as Alzheimer’s disease, dementia with Lewy bodies, or Parkinson’s disease, alterations in consciousness, loss of memory, visual hallucinations, Inhibitors,research,lifescience,medical or rapid eye movement (REM) sleep abnormalities have been associated with regional deficits in the cholinergic system. In the following sections, we will briefly discuss the value of using REM sleep as a surrogate marker of compounds acting on cholinergic neurotransmission, and particularly in the development

of cognitive enhancers for Alzheimer’s disease. REM sleep REM Inhibitors,research,lifescience,medical sleep was first, described in 1953 by Aserinsky and Brefeldin_A Kleitman.15 At, regular 90- to 100-min intervals, they observed the spontaneous emergence of electroenccphalographic (EEG) desynchronization accompanied by clusters of rapid saccadic eye movements. When subjects were awakened during such an episode, they generally reported that they had been dreaming. REM sleep is also called paradoxical sleep because of the close resemblance to the EEG of active wakefulness combined with a “paradoxical” active inhibition of major muscle groups that, seems to reflect, deep sleep. Normal sleep is characterized in EEG terms as recurrent, cycles of nonREM and REM sleep of about, 90 min. Non -REM sleep is subdivided into stages 1 through 4, with stage 1 being the lightest and stage 4 being the deepest sleep.

2 ?Related WorksCurrently, many secure data aggregation schemes h

2.?Related WorksCurrently, many secure data aggregation schemes have been proposed. For symmetric schemes, Ozdemir et al. [9] integrated false data detection with data aggregation and confidentiality, and proposed an authentication protocol. In the scheme, every aggregator has some monitoring nodes which also perform data aggregation for data verification, and the integrity of the encrypted data is verified by the sensors between two consecutive aggregators. Its limitation is the rigorous topological constraints. Papadopoulos et al. [10] presented an exact aggregation scheme with integrity and confidentiality, named SIES. SIES combines the symmetric homomorphic encryption with secret sharing. A wide range of aggregates can be covered, and a small amount of bandwidth consumption is introduced in SIES. However, the data transmission efficiency is low due to the oversize space of secret keys. Based on Aggregation-Commit-Verify approach, Chan et al. [12] first proposed a provably secure hierarchical data aggregation scheme, where the adversary is forced to commit to its choice of aggregation results, then the sensors are allowed to verify whether their aggregation contributions are correct or not. The scheme can be used for multiple malicious nodes and arbitrary topologies, but it inherits the weakness of large amount of communication and computation overheads. To address this issue, Frikken et al. [13] improve Chan’s scheme by reducing the maximum communication per node from O(��log2n) to O(��logn), where n is the number of nodes in WSNs, and �� is the maximum degree of the aggregation tree.For asymmetric schemes, Zhu et al. [14] focused on preserving data integrity and proposed an efficient integrity-preserving data aggregation protocol named EIPDAP. The scheme is based on the modulo addition operation using ECC, and has the most optimal upper bound on solving the integrity-preserving problem for data aggregation. Niu et al. [15] proposed a secure identity-based lossy data aggregation scheme using homomorphic selleck inhibitor hashing and identity-based aggregate signature. In the scheme, the authenticity of aggregated data can be verified by both aggregators and BS. The computation and communication overheads could be significantly reduced because the BS can perform batch verification. However, the above two schemes may lead to the leakage of data privacy due to decryption at the aggregator. Based on PH, Westhoff et al. [16] and Girao et al. [17] proposed CDA methods to facilitate aggregation in encrypted data, where richer algebraic operations can be directly executed on encrypted data by aggregators. Mykletun et al. [18] adopted several public-key-based PH encryptions to achieve data concealment in WSNs. Furthermore, Girao et al. [8] proposed a novel scheme by extending the ELGamal PH encryption. However, the above schemes cannot resist node compromise attacks. Specific security analysis is presented in Section 5.3.