Prevention of food allergy in infancy: the role of maternal interventions and exposures during pregnancy and lactation.

There is increased focus on the role of maternal interventions in the prevention of food allergy in infancy. There is no role for maternal dietary modifications during pregnancy or lactation, such as allergen avoidance, as a means of infant allergy prevention. Although exclusive breastfeeding is the recommended infant nutrition source globally, the effect of breastfeeding on infant allergy prevention remains unclear. There is emerging evidence that irregular cow's milk exposure (ie, infrequent formula supplementation) might increase the risk of cow's milk allergy. Although further studies are required, there is also emerging evidence that maternal peanut ingestion during breastfeeding along with early peanut introduction in infancy might have a preventive role. The effect of maternal dietary supplementation with vitamin D, omega-3, and prebiotics or probiotics remains unclear.

The effect of learning to drum on behavior and brain function in autistic adolescents.

This current study aimed to investigate the impact of drum training on behavior and brain function in autistic adolescents with no prior drumming experience. Thirty-six autistic adolescents were recruited and randomly assigned to one of two groups. The drum group received individual drum tuition (two lessons per week over an 8-wk period), while the control group did not. All participants attended a testing session before and after the 8-wk period. Each session included a drumming assessment, an MRI scan, and a parent completing questionnaires relating to the participants' behavioral difficulties. Results showed that improvements in drumming performance were associated with a significant reduction in hyperactivity and inattention difficulties in drummers compared to controls. The fMRI results demonstrated increased functional connectivity in brain areas responsible for inhibitory control, action outcomes monitoring, and self-regulation. In particular, seed-to-voxel analyses revealed an increased functional connectivity in the right inferior frontal gyrus and the right dorsolateral prefrontal cortex. A multivariate pattern analysis demonstrated significant changes in the medial frontal cortex, the left and right paracingulate cortex, the subcallosal cortex, the left frontal pole, the caudate, and the left nucleus accumbens. In conclusion, this study investigates the impact of a drum-based intervention on neural and behavioral outcomes in autistic adolescents. We hope that these findings will inform further research and trials into the potential use of drum-based interventions in benefitting clinical populations with inhibition-related disorders and emotional and behavioral difficulties.

Cost Utility of Lifelong Immunoglobulin Replacement Therapy vs Hematopoietic Stem Cell Transplant to Treat Agammaglobulinemia.

Importance: Lifelong immunoglobulin replacement therapy (IRT) is standard-of-care treatment for congenital agammaglobulinemia but accrues high annual costs ($30 000-$90 000 per year) and decrements to quality of life over patients' life spans. Hematopoietic stem cell transplant (HSCT) offers an alternative 1-time therapy, but has high morbidity and mortality. Objective: To evaluate the cost utility of IRT vs matched sibling donor (MSD) and matched unrelated donor (MUD) HSCT to treat patients with agammaglobulinemia in the US. Design, Setting, and Participants: This economic evaluation used Markov analysis to model the base-case scenario of a patient aged 12 months with congenital agammaglobulinemia receiving lifelong IRT vs MSD or MUD HSCT. Costs, probabilities, and quality-of-life measures were derived from the literature. Microsimulations estimated premature deaths for each strategy in a virtual cohort. One-way sensitivity and probabilistic sensitivity analyses evaluated uncertainty around parameter estimates performed from a societal perspective over a 100-year time horizon. The threshold for cost-effective care was set at $100 000 per quality-adjusted life-year (QALY). This study was conducted from 2020 across a 100-year time horizon. Exposures: Immunoglobulin replacement therapy vs MSD or MUD HSCT for treatment of congenital agammaglobulinemia. Main Outcomes and Measures: The primary outcomes were incremental cost-effectiveness ratio (ICER) expressed in 2020 US dollars per QALY gained and premature deaths associated with each strategy. Results: In this economic evaluation of patients with congenital agammaglobulinemia, lifelong IRT cost more than HSCT ($1 512 946 compared with $563 776 [MSD] and $637 036 [MUD]) and generated similar QALYs (20.61 vs 17.25 [MSD] and 17.18 [MUD]). Choosing IRT over MSD or MUD HSCT yielded ICERs of $282 166 per QALY gained over MSD and $255 633 per QALY gained over MUD HSCT, exceeding the US willingness-to-pay threshold of $100 000/QALY. However, IRT prevented at least 2488 premature deaths per 10 000 microsimulations compared with HSCT. When annual IRT price was reduced from $60 145 to below $29 469, IRT became the cost-effective strategy. Findings remained robust in sensitivity and probabilistic sensitivity analyses. Conclusions and Relevance: In the US, IRT is more expensive than HSCT for agammaglobulinemia treatment. The findings of this study suggest that IRT prevents more premature deaths but does not substantially increase quality of life relative to HSCT. Reducing US IRT cost by 51% to a value similar to IRT prices in countries implementing value-based pricing may render it the more cost-effective strategy.

Rhinitis 2020: A practice parameter update.

This comprehensive practice parameter for allergic rhinitis (AR) and nonallergic rhinitis (NAR) provides updated guidance on diagnosis, assessment, selection of monotherapy and combination pharmacologic options, and allergen immunotherapy for AR. Newer information about local AR is reviewed. Cough is emphasized as a common symptom in both AR and NAR. Food allergy testing is not recommended in the routine evaluation of rhinitis. Intranasal corticosteroids (INCS) remain the preferred monotherapy for persistent AR, but additional studies support the additive benefit of combination treatment with INCS and intranasal antihistamines in both AR and NAR. Either intranasal antihistamines or INCS may be offered as first-line monotherapy for NAR. Montelukast should only be used for AR if there has been an inadequate response or intolerance to alternative therapies. Depot parenteral corticosteroids are not recommended for treatment of AR due to potential risks. While intranasal decongestants generally should be limited to short-term use to prevent rebound congestion, in limited circumstances, patients receiving regimens that include an INCS may be offered, in addition, an intranasal decongestant for up to 4 weeks. Neither acupuncture nor herbal products have adequate studies to support their use for AR. Oral decongestants should be avoided during the first trimester of pregnancy. Recommendations for use of subcutaneous and sublingual tablet allergen immunotherapy in AR are provided. Algorithms based on a combination of evidence and expert opinion are provided to guide in the selection of pharmacologic options for intermittent and persistent AR and NAR.

Drum training induces long-term plasticity in the cerebellum and connected cortical thickness.

It is unclear to what extent cerebellar networks show long-term plasticity and accompanied changes in cortical structures. Using drumming as a demanding multimodal motor training, we compared cerebellar lobular volume and white matter microstructure, as well as cortical thickness of 15 healthy non-musicians before and after learning to drum, and 16 age matched novice control participants. After 8 weeks of group drumming instruction, 3 ×30 minutes per week, we observed the cerebellum significantly changing its grey (volume increase of left VIIIa, relative decrease of VIIIb and vermis Crus I volume) and white matter microstructure in the inferior cerebellar peduncle. These plastic cerebellar changes were complemented by changes in cortical thickness (increase in left paracentral, right precuneus and right but not left superior frontal thickness), suggesting an interplay of cerebellar learning with cortical structures enabled through cerebellar pathways.

Predictive Model for Delivery Efficiency: Erythrocyte Membrane-Camouflaged Magnetofluorescent Nanocarriers Study.

Delivery efficiencies of theranostic nanoparticles (NPs) based on passive tumor targeting strongly depend either on their blood circulation time or on appropriate modulations of the tumor microenvironment. Therefore, predicting the NP delivery efficiency before and after a tumor microenvironment modulation is highly desirable. Here, we present a new erythrocyte membrane-camouflaged magnetofluorescent nanocarrier (MMFn) with long blood circulation time (92 h) and high delivery efficiency (10% ID for Ehrlich murine tumor model). MMFns owe their magnetic and fluorescent properties to the incorporation of manganese ferrite nanoparticles (MnFe2O4 NPs) and IR-780 (a lipophilic indocyanine fluorescent dye), respectively, to their erythrocyte membrane-derived camouflage. MMFn composition, morphology, and size, as well as optical absorption, zeta potential, and fluorescent, magnetic, and magnetothermal properties, are thoroughly examined in vitro. We then present an analytical pharmacokinetic (PK) model capable of predicting the delivery efficiency (DE) and the time of peak tumor uptake (tmax), as well as changes in DE and tmax due to modulations of the tumor microenvironment, for potentially any nanocarrier. Experimental PK data sets (blood and tumor amounts of MMFns) are simultaneously fit to the model equations using the PK modeling software Monolix. We then validate our model analytical solutions with the numerical solutions provided by Monolix. We also demonstrate how our a priori nonmechanistic model for passive targeting relates to a previously reported mechanistic model for active targeting. All in vivo PK studies, as well as in vivo and ex vivo biodistribution studies, were conducted using two noninvasive techniques, namely, fluorescence molecular tomography (FMT) and alternating current biosusceptometry (ACB). Finally, histopathology corroborates our PK and biodistribution results.

Utilization of Complementary and Alternative Therapies in Youth with Developmental Disabilities.

Oxidative stress is understood to be involved in the ontology and maintenance of different developmental disabilities. Some complementary and alternative medicine (CAM) therapies have been proposed to modify this relationship by affecting oxidative stress pathways. However, it is unclear which of these CAM therapies are used among children with different developmental disabilities. This study examines the use of these therapies among 10,218 children between the ages of 4 and 17 using the 2012 Child Complementary and Alternative Medicine (CAM) Supplement of the National Health Interview Survey (NHIS) to highlight a potential avenue for intervention and prevention efforts. The results suggest that children with developmental disabilities are more likely to utilize particular CAM therapies that may alter oxidative stress pathways. Future work is needed to assess the potential moderating effect of these CAM therapies and oxidative stress levels among children with different developmental disabilities.

Triggered release of paclitaxel from magnetic solid lipid nanoparticles by magnetic hyperthermia.

We developed a magnetic solid lipid nanoparticles formulation of paclitaxel (PTX-loaded MSLNs) via emulsification-diffusion method. The physicochemical characterization of PTX-loaded MSLNs was performed by AFM, DLS, determination of entrapment efficiency (EE) and drug loading (DL), DSC, VSM, and physical stability. The in vitro effect of temperature and pulsed magnetic hyperthermia on drug release were studied. PTX-loaded MSLNs had a particle diameter around 250 nm with a narrow size distribution, spherical morphology, EE of 67.3 ±â€¯1.2% and a DL of 17.1 ±â€¯0.4 µg/mg. A decrease of the melting point of the lipid was observed following the preparation of the MSLNs. A threefold increase in the in vitro drug release rate was seen when temperature was raised from 25 to 43 °C. The lipid coating of MPs confer a temperature-dependent drug release and magnetic hyperthermia was used to trigger controlled PTX release from MSLNs.

Safety pharmacology investigations on the nervous system: An industry survey.

The Safety Pharmacology Society (SPS) conducted an industry survey in 2015 to identify industry practices as they relate to central, peripheral and autonomic nervous system ('CNS') drug safety testing. One hundred fifty-eight (158) participants from Asia (16%), Europe (20%) and North America (56%) responded to the survey. 52% of participants were from pharmaceutical companies (>1000 employees). Oncology (67%) and neurology/psychiatry (66%) were the most frequent target indications pursued by companies followed by inflammation (48%), cardiovascular (43%), metabolic (39%), infectious (37%), orphan (32%) and respiratory (29%) diseases. Seizures (67% of participants), gait abnormalities (67%), tremors (65%), emesis (56%), sedation (52%) and salivation (47%) were the most commonly encountered CNS issues in pre-clinical drug development while headache (65%), emesis/nausea (60%), fatigue (51%) and dizziness (49%) were the most frequent issues encountered in Phase I clinical trials. 54% of respondents reported that a standard battery of tests applied to screen drug candidates was the approach most commonly used to address non-clinical CNS safety testing. A minority (14% of all participants) reported using electroencephalography (EEG) screening prior to animal inclusion on toxicology studies. The most frequent group size was n=8 for functional observation battery (FOB), polysomnography and seizure liability studies. FOB evaluations were conducted in a dedicated room (78%) by blinded personnel (66%) with control for circadian cycle (55%) effects (e.g., dosing at a standardized time; balancing time of day across treatment groups). The rat was reported as the most common species used for seizure liability, nerve conduction and drug-abuse liability testing.

Mean-field and linear regime approach to magnetic hyperthermia of core-shell nanoparticles: can tiny nanostructures fight cancer?

The phenomenon of heat dissipation by magnetic materials interacting with an alternating magnetic field, known as magnetic hyperthermia, is an emergent and promising therapy for many diseases, mainly cancer. Here, a magnetic hyperthermia model for core-shell nanoparticles is developed. The theoretical calculation, different from previous models, highlights the importance of heterogeneity by identifying the role of surface and core spins on nanoparticle heat generation. We found that the most efficient nanoparticles should be obtained by selecting materials to reduce the surface to core damping factor ratio, increasing the interface exchange parameter and tuning the surface to core anisotropy ratio for each material combination. From our results we propose a novel heat-based hyperthermia strategy with the focus on improving the heating efficiency of small sized nanoparticles instead of larger ones. This approach might have important implications for cancer treatment and could help improving clinical efficacy.

EEG in non-clinical drug safety assessments: Current and emerging considerations.

Electroencephalogram (EEG) data in nonclinical species can play a critical role in the successful evaluation of a compound during drug development, particularly in the evaluation of seizure potential and for monitoring changes in sleep. Yet, while non-invasive electrocardiogram (ECG) monitoring is commonly included in preclinical safety studies, pre-dose or post-dose EEG assessments are not. Industry practices as they relate to preclinical seizure liability and sleep assessments are not well characterized and the extent of preclinical EEG testing varies between organizations. In the current paper, we discuss the various aspects of preclinical EEG to characterize drug-induced seizure risk and sleep disturbances, as well as describe the use of these data in a regulatory context. An overview of EEG technology-its correct application and its limitations, as well as best practices for setting up the animal models is presented. Sleep and seizure detection are discussed in detail. A regulatory perspective on the use of EEG data is provided and, tying together the previous topics is a discussion of the translational aspects of EEG.

Effect of magnetic dipolar interactions on nanoparticle heating efficiency: implications for cancer hyperthermia.

Nanostructured magnetic systems have many applications, including potential use in cancer therapy deriving from their ability to heat in alternating magnetic fields. In this work we explore the influence of particle chain formation on the normalized heating properties, or specific loss power (SLP) of both low- (spherical) and high- (parallelepiped) anisotropy ferrite-based magnetic fluids. Analysis of ferromagnetic resonance (FMR) data shows that high particle concentrations correlate with increasing chain length producing decreasing SLP. Monte Carlo simulations corroborate the FMR results. We propose a theoretical model describing dipole interactions valid for the linear response regime to explain the observed trends. This model predicts optimum particle sizes for hyperthermia to about 30% smaller than those previously predicted, depending on the nanoparticle parameters and chain size. Also, optimum chain lengths depended on nanoparticle surface-to-surface distance. Our results might have important implications to cancer treatment and could motivate new strategies to optimize magnetic hyperthermia.

Multimodality evaluation of patients with gastroesophageal reflux disease symptoms who have failed empiric proton pump inhibitor therapy.

Patients with symptoms suggestive of gastroesophageal reflux disease (GERD), such as chest pain, heartburn, regurgitation, and dysphagia, are typically treated initially with a course of proton pump inhibitors (PPIs). The evaluation of patients who have either not responded at all or partially and inadequately responded to such therapy requires a more detailed history and may involve an endoscopy and esophageal biopsies, followed by esophageal manometry, ambulatory esophageal pH monitoring, and gastric emptying scanning. To assess the merits of a multimodality 'structural' and 'functional' assessment of the esophagus in patients who have inadequately controlled GERD symptoms despite using empiric PPI, a retrospective cohort study of patients without any response or with poor symptomatic control to empiric PPI (>2 months duration) who were referred to an Esophageal Studies Unit was conducted. Patients were studied using symptom questionnaires, endoscopy (+ or - for erosive disease, or Barrett's metaplasia) and multilevel esophageal biopsies (eosinophilia, metaplasia), esophageal motility (aperistalsis, dysmotility), 24-hour ambulatory esophageal pH monitoring (+ if % total time pH < 4 > 5%), and gastric emptying scanning (+ if >10% retention at 4 hours and >70% at 2 hours). Over 3 years, 275 patients (147 men and 128 women) aged 16-89 years underwent complete multimodality testing. Forty percent (n= 109) had nonerosive reflux disease (esophagogastroduodenoscopy [EGD]-, biopsy-, pH+); 19.3% (n= 53) had erosive esophagitis (EGD+); 5.5% (n= 15) Barrett's esophagus (EGD+, metaplasia+); 5.5% (n= 15) eosinophilic esophagitis (biopsy+); 2.5% (n= 7) had achalasia and 5.8% (n= 16) other dysmotility (motility+, pH-); 16% (n= 44) had functional heartburn (EGD-, pH-), and 5.8% (n= 16) had gastroparesis (gastric scan+). Cumulative symptom scores for chest pain, heartburn, regurgitation, and dysphagia were similar among the groups (mean range 1.1-1.35 on a 0-3 scale). Multimodality evaluation changed the diagnosis of GERD in 34.5% of cases and led to or guided alternative therapies in 42%. Overlap diagnoses were frequent: 10/15 (67%) of patients with eosinophilic esophagitis, 12/16 (75%) of patients with gastroparesis, and 11/23 (48%) of patients with achalasia or dysmotility had concomitant pathologic acid reflux by pH studies. Patients with persistent GERD symptoms despite empiric PPI therapy benefit from multimodality evaluation that may change the diagnosis and guide therapy in more than one third of such cases. Because symptoms are not specific and overlap diagnoses are frequent and multifaceted, objective evidence-driven therapies should be considered in such patients.

A biomechanical comparison of periprosthetic femoral fracture fixation in normal and osteoporotic cadaveric bone.

Several techniques are described for fixation of Vancouver B1 femoral shaft fractures after total hip arthroplasty. Twenty-four femurs were scanned by dual x-ray absorptiometry scanned and matched for bone mineral density. Femurs were implanted with a cemented simulated total hip prosthesis with a simulated periprosthetic femur fracture distal to the stem. Fractures were fixed with Synthes (Paoli, Pa) 12-hole curved plates and 4 different constructs proximally. Each construct was loaded to failure in axial compression. Constructs with locking and nonlocking screws demonstrated equivalent loads at failure and were superior in load at failure compared with cables. Cable constructs failed proximally. No proximal failures occurred in specimens fixed with screws and cables. A combination of locked or nonlocked screws and supplemental cable fixation is recommended for the treatment of Vancouver B1 periprosthetic femur fractures.

Effects of a yoga breath intervention alone and in combination with an exposure therapy for post-traumatic stress disorder and depression in survivors of the 2004 South-East Asia tsunami.

OBJECTIVE: This study evaluated the effect of a yoga breath program alone and followed by a trauma reduction exposure technique on post-traumatic stress disorder and depression in survivors of the 2004 Asian tsunami. METHOD: In this non-randomized study, 183 tsunami survivors who scored 50 or above on the Post-traumatic Checklist-17 (PCL-17) were assigned by camps to one of three groups: yoga breath intervention, yoga breath intervention followed by 3-8 h of trauma reduction exposure technique or 6-week wait list. Measures for post-traumatic stress disorder (PCL-17) and depression (BDI-21) were performed at baseline and at 6, 12 and 24 weeks. Data were analyzed using anova and mixed effects regression. RESULTS: The effect of treatment vs. control was significant at 6 weeks (F(2,178) = 279.616, P < 0.001): mean PCL-17 declined by 42.5 +/- 10.0 SD with yoga breath, 39.2 +/- 17.2 with Yoga breath + exposure and 4.6 +/- 13.2 in the control. CONCLUSION: Yoga breath-based interventions may help relieve psychological distress following mass disasters.

Bleeding complications after oral surgery in outpatients with compromised haemostasis: incidence and management.

UNLABELLED: PURPOSE AND RESULTS: The aim of this prospective study was to determine the incidence of postoperative bleeding after oral surgery under local anaesthesia performed in outpatients with haemostatic disorders within a 5-year period (2003-2007). One hundred twenty one (70 males, 51 females) out of 2,056 outpatients with different haemostatic disorders (acquired or hereditary) were included in this study. The following data were recorded: medical history and general condition; medications; indication for the surgical procedure; specification of local anaesthesia; applied surgical techniques, considering the kind of haemostatic disorder; and peri- or postoperative bleeding complications. Postoperative bleeding was observed in 12 patients (9.9%). In three cases, inpatient treatment became necessary. The management of two patients with a haemostatic disorder (von Willebrand s disease and haemophilia A) is presented in short case reports. CONCLUSION: In a heterogeneous group of 121 outpatients with known haemostatic disorders, a combination of a few haemostatic agents with appropriate operative technique enables an effective wound management. In cases of failed local interventions after postoperative bleeding, further diagnostic investigations are required.

Evidence that oxidative stress is a risk factor for the development of squamous cell carcinoma in renal transplant patients.

Renal transplant patients are at a greatly increased risk of skin malignancy, particularly squamous cell carcinoma (SCC), a tumor closely associated with UV exposure. There is also significant interindividual skin cancer risk among transplant patients, with evidence suggesting that this derives from variation in response to oxidative stress. Our aim was to assess urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), by liquid chromatography-tandem mass spectrometry, in renal transplant patients with and without SCC. The relationships between SCC and urinary 8-oxodG were analyzed by conditional logistic regression and those between 8-oxodG and other candidate variables by linear regression, correcting for the effect of SCC. In SCC patients, urinary 8-oxodG was significantly elevated (p=0.03), both pre- and post-tumor development, compared to non-SCC transplant patients. Secondary analyses indicated that 8-oxodG was related to current heavy smoking (p=0.02) and darker skin type (p=0.02), but not measures of previous chronic sun exposure or current age and gender. Although subject numbers were limited, immunosuppression with azathioprine was positively associated with 8-oxodG in all patients combined (p=0.02). These results demonstrate, for the first time, that a subpopulation of renal transplant patients is under greater oxidative burden, and it is this population that is particularly predisposed to skin cancer.

Deoxycytidine glyoxal: lesion induction and evidence of repair following vitamin C supplementation in vivo.

Oxidative DNA damage is postulated to be involved in carcinogenesis, and as a consequence, dietary antioxidants have received much interest. A recent report indicates that vitamin C facilitates the decomposition of hydroperoxides in vitro, generating reactive aldehydes. We present evidence for the in vivo generation of glyoxal, an established product of lipid peroxidation, glucose/ascorbate autoxidation, or free radical attack of deoxyribose, following supplementation of volunteers with 400 mg/d vitamin C. Utilizing a monoclonal antibody to a deoxycytidine-glyoxal adduct (gdC), we measured DNA lesion levels in peripheral blood mononuclear cells. Supplementation resulted in significant (p =.001) increases in gdC levels at weeks 11, 16, and 21, with corresponding increases in plasma malondialdehyde levels and, coupled with previous findings, is strongly suggestive of a pro-oxidative effect. However, continued supplementation revealed a highly significant (p =.0001) reduction in gdC levels. Simultaneous analysis of cyclobutane thymine dimers revealed no increase upon supplementation but, as with gdC, levels decreased. Although no single mechanism is identified, our data demonstrate a pro-oxidant event in the generation of reactive aldehydes following vitamin C supplementation in vivo. These results are also consistent with our hypothesis for a role of vitamin C in an adaptive/repair response and indicate that nucleotide excision repair specifically may be affected.

Modulation of the degree and pattern of methyl-esterification of pectic homogalacturonan in plant cell walls. Implications for pectin methyl esterase action, matrix properties, and cell adhesion.

Homogalacturonan (HG) is a multifunctional pectic polysaccharide of the primary cell wall matrix of all land plants. HG is thought to be deposited in cell walls in a highly methyl-esterified form but can be subsequently de-esterified by wall-based pectin methyl esterases (PMEs) that have the capacity to remove methyl ester groups from HG. Plant PMEs typically occur in multigene families/isoforms, but the precise details of the functions of PMEs are far from clear. Most are thought to act in a processive or blockwise fashion resulting in domains of contiguous de-esterified galacturonic acid residues. Such de-esterified blocks of HG can be cross-linked by calcium resulting in gel formation and can contribute to intercellular adhesion. We demonstrate that, in addition to blockwise de-esterification, HG with a non-blockwise distribution of methyl esters is also an abundant feature of HG in primary plant cell walls. A partially methyl-esterified epitope of HG that is generated in greatest abundance by non-blockwise de-esterification is spatially regulated within the cell wall matrix and occurs at points of cell separation at intercellular spaces in parenchymatous tissues of pea and other angiosperms. Analysis of the properties of calcium-mediated gels formed from pectins containing HG domains with differing degrees and patterns of methyl-esterification indicated that HG with a non-blockwise pattern of methyl ester group distribution is likely to contribute distinct mechanical and porosity properties to the cell wall matrix. These findings have important implications for our understanding of both the action of pectin methyl esterases on matrix properties and mechanisms of intercellular adhesion and its loss in plants.