Prevalence of Permethrin Resistance in Culex Tarsalis Populations in Southern California.

In the western United States, Culex tarsalis is the most important vector of West Nile virus. Insecticides containing permethrin or other pyrethroid compounds are commonly used to control these mosquitoes. Because of the range of environments where Cx. tarsalis are found, this species is under insecticide pressure from both vector control and agricultural spraying. Mosquito populations may evolve resistance through mechanisms such as target site insensitivity, including the frequently identified knockdown resistance (kdr) mutations. Prevalence of permethrin resistance was determined for Cx. tarsalis from 5 southern California field sites representing 2 distinct valley regions (Coachella Valley and Inland Valley), which are geographically separated by the north-south-running Peninsular Mountain Ranges. These two valley regions are >100 km apart and vary considerably in their environmental and habitat characteristics. Permethrin resistance in mosquito populations was determined by the Centers for Disease Control and Prevention (CDC) bottle bioassay, using glass bottles coated with permethrin at 0.19 µg/cm2 of internal surface. Permethrin resistance was evident in Cx. tarsalis populations from the Coachella Valley field sites with all sites showing similar mortality in the bottle bioassay, while Cx. tarsalis from the Inland Valley field sites were largely susceptible to permethrin, with mortality rates that were similar to a susceptible lab strain of Cx. tarsalis.

Diversity and Biocontrol Potential of Endophytic Fungi and Bacteria Associated with Healthy Welsh Onion Leaves in Taiwan.

Foliar diseases caused by Stemphylium and Colletotrichum species are among the major biotic factors limiting Welsh onion production in Taiwan. Owing to concerns about the environment and the development of pathogen resistance to existing fungicides, biological control using endophytes is emerging as an eco-friendly alternative to chemical control. The aim of the present study was to isolate endophytes from healthy Welsh onion leaves and investigate their antagonistic potential against the major phytopathogenic fungi associated with Welsh onion plants in Taiwan. A total of 109 bacterial and 31 fungal strains were isolated from healthy Welsh onion leaves and assigned to 16 bacterial and nine fungal genera using morphological and molecular characterization based on DNA sequence data obtained from nuclear internal transcribed spacer (nrITS) (fungi) and 16S rRNA (bacteria). Evaluation of these endophytic isolates for biocontrol activity against leaf blight pathogens Colletotrichum spaethianum strain SX15-2 and Stemphylium vesicarium strain SX20-2 by dual culture assay and greenhouse experiments resulted in the identification of two bacterial isolates (GFB08 and LFB28) and two fungal isolates (GFF06 and GFF08) as promising antagonists to leaf blight pathogens. Among the four selected isolates, Bacillus strain GFB08 exhibited the highest disease control in the greenhouse study. Therefore, Bacillus strain GFB08 was further evaluated to understand the mechanism underlying its biocontrol efficacy. A phylogenetic analysis based on six genes identified Bacillus strain GFB08 as B. velezensis. The presence of antimicrobial peptide genes (baer, bamC, bmyB, dfnA, fenD, ituC, mlna, and srfAA) and the secretion of several cell wall degrading enzymes (CWDEs), including cellulase and protease, confirmed the antifungal nature of B. velezensis strain GFB08. Leaf blight disease suppression by preventive and curative assays indicated that B. velezensis strain GFB08 has preventive efficacy on C. spaethianum strain SX15-2 and both preventive and curative efficacy on S. vesicarium strain SX20-2. Overall, the current study revealed that healthy Welsh onion leaves harbour diverse bacterial and fungal endophytes, among which the endophytic bacterial strain, B. velezensis strain GFB08, could potentially be used as a biocontrol agent to manage the leaf blight diseases of Welsh onion in Taiwan.

Small RNA sequencing of field Culex mosquitoes identifies patterns of viral infection and the mosquito immune response.

Mosquito-borne disease remains a significant burden on global health. In the United States, the major threat posed by mosquitoes is transmission of arboviruses, including West Nile virus by mosquitoes of the Culex genus. Virus metagenomic analysis of mosquito small RNA using deep sequencing and advanced bioinformatic tools enables the rapid detection of viruses and other infecting organisms, both pathogenic and non-pathogenic to humans, without any precedent knowledge. In this study, we sequenced small RNA samples from over 60 pools of Culex mosquitoes from two major areas of Southern California from 2017 to 2019 to elucidate the virome and immune responses of Culex. Our results demonstrated that small RNAs not only allowed the detection of viruses but also revealed distinct patterns of viral infection based on location, Culex species, and time. We also identified miRNAs that are most likely involved in Culex immune responses to viruses and Wolbachia bacteria, and show the utility of using small RNA to detect antiviral immune pathways including piRNAs against some pathogens. Collectively, these findings show that deep sequencing of small RNA can be used for virus discovery and surveillance. One could also conceive that such work could be accomplished in various locations across the world and over time to better understand patterns of mosquito infection and immune response to many vector-borne diseases in field samples.

Satellite Rearing of Aedes Mosquito Eggs: Synchronized Empirical Test of a Novel Mass Rearing Model.

Mosquito suppression strategies based on "rear and release" of male mosquitoes are attracting renewed interest from governments, municipalities, and private businesses. These include irradiation-based sterile insect technique, Wolbachia-based technologies, and genetic modification. Each of these approaches requires the mass rearing and release of adult male mosquitoes, which typically is accomplished via a rearing facility near the release site. Although some release programs have relied on centralized rearing and shipment of adult males, adult male mosquitoes are relatively fragile, and their fitness can be diminished by temperature fluctuations, humidity, nutritional deficiencies, and other stresses that occur during shipment. Furthermore, expensive, expedited shipment is typically used to maximize the amount of adult lifetime in the field following the release. In contrast, Aedes aegypti and Ae. albopictus eggs can be desiccated and stored for long periods. They are small, and many millions of eggs can be shipped without specialized environmental conditions and using less expensive means. Here we examine a model in which mosquito eggs are centrally produced and then mailed to satellite rearing facilities. As a control, a replicate set of eggs was reared at the factory of origin. At each of the rearing sites, cloud-based software was used to track and compare rearing at the different locations. The results demonstrate similar rearing outcomes (i.e., egg hatch, immature development, and number of adult males) at each of the different sites for both species. We discuss the outcome in relation to downstream applications and potential future studies.

Efficacy of Limited Dose Modifications for Palbociclib-Related Grade 3 Neutropenia in Hormone Receptor–Positive Metastatic Breast Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Frequent neutropenia hinders uninterrupted palbociclib treatment in patients with hormone receptor (HR)–positive breast cancer. We compared the efficacy outcomes in multicenter cohorts of patients with metastatic breast cancer (mBC) receiving palbociclib following conventional dose modification or limited modified schemes for afebrile grade 3 neutropenia. @*Materials and Methods@#Patients with HR-positive, human epidermal growth factor receptor 2–negative mBC (n=434) receiving palbociclib with letrozole as first-line therapy were analyzed and classified based on neutropenia grade and afebrile grade 3 neutropenia management as follows: group 1 (maintained palbociclib dose, limited scheme), group 2 (dose delay or reduction, conventional scheme), group 3 (no afebrile grade 3 neutropenia event), and group 4 (grade 4 neutropenia event). The primary and secondary endpoints were progression-free survival (PFS) between groups 1 and 2 and PFS, overall survival, and safety profiles among all groups. @*Results@#During follow-up (median 23.7 months), group 1 (2-year PFS, 67.9%) showed significantly longer PFS than did group 2 (2-year PFS, 55.3%; p=0.036), maintained across all subgroups, and upon adjustment of the factors. Febrile neutropenia occurred in one and two patients of group 1 and group 2, respectively, without mortality. @*Conclusion@#Limited dose modification for palbociclib-related grade 3 neutropenia may lead to longer PFS, without increasing toxicity, than the conventional dose scheme.

Comparison of Programmed Cell Death Ligand 1Status between Core Needle Biopsy and Surgical Specimens of Triple-Negative Breast Cancer

Purpose@#Pembrolizumab is currently used to treat advanced triple-negative breast cancer (TNBC) and high-risk early TNBC with neoadjuvant chemotherapy (NAC). The tumor-infiltrating lymphocyte (TIL) level and programmed cell death ligand 1 (PDL1) status are predictors of response to NAC and immune checkpoint inhibitor treatment. We aimed to investigate whether the PD-L1 status in core needle biopsies (CNBs) could represent the whole tumor in TNBC. @*Materials and Methods@#A total of 49 patients diagnosed with TNBC who received upfront surgery without NAC between January 2018 and March 2021 were included. The PD-L1 expression (SP142 and 22C3 clones) and TIL were evaluated in paired CNBs and resected specimens. The concordance PD-L1 status and TIL levels between CNBs and resected specimens were analyzed. @*Results@#PD-L1 positivity was more frequently observed in resected specimens. The overall reliability of TIL level in the CNB was good [intraclass correlation coefficient (ICC)=0.847, p<0.001]. The agreements of PD-L1 status were good and fair, respectively (SP142, κ=0.503, p<0.001; 22C3, κ=0.380, p=0.010). As the core number of CNB increased, the reliability and agreement also improved, especially from five tumor cores (TIL, ICC=0.911, p<0.001; PD-L1 [22C3], κ=0.750, p=0.028). Regarding PD-L1 (SP142), no further improvement was observed with ≥5 tumor cores (κ=0.600, p=0.058). @*Conclusion@#CNBs with ≥5 tumor cores were sufficient to represent the TIL level and PD-L1 (22C3) status in TNBC.

St. Louis Encephalitis Virus in the Southwestern United States: A Phylogeographic Case for a Multi-Variant Introduction Event.

Since the reemergence of St. Louis Encephalitis (SLE) Virus (SLEV) in the Southwest United States, identified during the 2015 outbreak in Arizona, SLEV has been seasonally detected within Culex spp. populations throughout the Southwest United States. Previous work revealed the 2015 outbreak was caused by an importation of SLEV genotype III, which had only been detected previously in Argentina. However, little is known about when the importation occurred or the transmission and genetic dynamics since its arrival into the Southwest. In this study, we sought to determine whether the annual detection of SLEV in the Southwest is due to enzootic cycling or new importations. To address this question, we analyzed 174 SLEV genomes (142 sequenced as part of this study) using Bayesian phylogenetic analyses to estimate the date of arrival into the American Southwest and characterize the underlying population structure of SLEV. Phylogenetic clustering showed that SLEV variants circulating in Maricopa and Riverside counties form two distinct populations with little evidence of inter-county transmission since the onset of the outbreak. Alternatively, it appears that in 2019, Yuma and Clark counties experienced annual importations of SLEV that originated in Riverside and Maricopa counties. Finally, the earliest representatives of SLEV genotype III in the Southwest form a polytomy that includes both California and Arizona samples. We propose that the initial outbreak most likely resulted from the importation of a population of SLEV genotype III variants, perhaps in multiple birds, possibly multiple species, migrating north in 2013, rather than a single variant introduced by one bird.

Identification of Volatiles From Plants Infested With Honeydew-Producing Insects, and Attraction of House Flies (Diptera: Muscidae) to These Volatiles.

House flies (Musca domestica L.) are mechanical vectors of food-borne pathogens including Salmonella spp., Escherichia coli O157:H7, and Shigella spp., resulting in increased risk of diarrheal disease in areas where flies are abundant. Movement of house flies into food crops may be increased by the presence of honeydew-producing insects feeding on these crops. Using gas chromatography-electroantennogram detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS), volatile odors that elicited house fly antennal response were identified from naval orange (Osbeck) (Sapindales: Rutaceae) and Marsh grapefruit (Macfad.) (Sapindales: Rutaceae) leaves infested with whitefly (Hemiptera: Aleyrodidae) and from whole faba (L.) (Fabales: Fabaceae) bean plants infested with aphids (Hemiptera: Aphididae). Volatiles identified included benzaldehyde, butyl hexanoate, ß-caryophyllene, Δ3-carene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), (Z)-3-hexenyl acetate, myrcene, limonene, linalool, and naphthalene. This was followed by semifield bioassays of volatile blends and individual volatiles to determine house fly attraction to these volatiles. Although fly capture rates in the semifield setting were low, benzaldehyde and (Z)-3-hexenyl acetate were consistently attractive to house flies as individual compounds and as components of volatile blends.

Preparation of a Novel Flame Retardant Formulation for Cotton Fabric.

A novel halogen-free flame-retardant formulation was prepared and coated onto cotton fabrics. The structure of phosphorus compounds in the system was characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and nuclear magnetic resonance spectroscopy (1H-NMR). Results from the ATR-FTIR spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) analyses presented that the flame retardant was coated successfully onto a cotton surface. We investigated the thermal stability and fire-retardant behaviors of cotton fabrics using thermal gravimetric analysis (TGA) and the vertical flame test. We also discuss the mechanism of flame retardance of coated cotton fabrics.

Immune-related Adverse Events: Overview and Management Strategies for the Use of Immune Checkpoint Inhibitors

Recent studies on T cell immunology have been instrumental in developing therapies to overcome cancer immune escape, and immune checkpoint inhibitors have emerged as one of the most promising therapeutic tools in advanced cancer patients. Immune checkpoint inhibitors (ICPIs) are monoclonal antibodies that modulate the effects of immune checkpoints. These include cytotoxic T lymphocyte antigen 4 and programmed cell death protein 1, which are co-inhibitory signals responsible for immune suppression. Despite their clinical benefits, ICPIs behave as general immune activators, exerting to several toxic effects called immune-related adverse events attributed to organ-specific inflammation. Here, we review ICPI toxicities, highlighting the importance of their early identification and proper management.

Real-World Analysis of the Efficacy of Rebiopsy and EGFR Mutation Test of Tissue and Plasma Samples in Drug-Resistant Non-Small Cell Lung Cancer

PURPOSE: Standard treatment for cases of non-small cell lung cancer (NSCLC) exhibiting acquired drug resistance includes tumor rebiopsy, epidermal growth factor receptor (EGFR) mutation testing (e.g., for T790M mutations), and the subsequent administration of third-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs). However, rebiopsies are typically invasive, costly, and occasionally not feasible. Therefore, the present study aimed to assess rebiopsy procedures by analyzing real-world data collected by the ASTRIS study of patients with resistant NSCLC. MATERIALS AND METHODS: The present study used statistical models to evaluate data collected by the ASTRIS trial (NCT02474355) conducted at Yonsei Cancer Center, including the rebiopsy success rate, incidence of T790M mutations in collected tissue and plasma samples, and association of administered osimertinib treatment efficacy. RESULTS: In a total of 188 screened patients, 112 underwent rebiopsy. An adequate tumor specimen was obtained in 95 of these patients, the greatest majority of whom (43.8%) were subjected to bronchoscopy. T790M mutations were detected in 53.3% of successfully EGFR-tested rebiopsy samples. A total of 88 patients received osimertinib treatment, and the objective response rate and median progression-free survival time was 44.3% and 32.7 weeks, respectively, among the treated patients overall, but 57.8% and 45.0 weeks, and 35.2% and 20.4 weeks among patients who exhibited T790M-positive tissue (n=45) and plasma (n=54) samples, respectively. CONCLUSION: Approximately 60% of patients in the analyzed real-world cohort were eligible for tissue rebiopsy upon NSCLC progression. Osimertinib activity was higher in patients in whom T790M mutations were detected in tissues rather than in plasma samples.

Prognoses and Clinical Outcomes of Primary and Recurrent Uveal Melanoma / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Uveal melanoma has a very poor prognosis despite successful local primary tumor treatment. In this study, we investigated prognostic factors that more accurately reflected the likelihood of recurrence and survival and delineated a prognostic model that could effectively identify different risk groups based on initial clinical parameters. MATERIALS AND METHODS: Prognostic factors associated with distant recurrence, recurrence-free survival (RFS), progression-free survival, and overall survival from distant recurrence to death (OS2) were analyzed in 226 patients with stage I-III uveal melanoma who underwent primary local therapy. RESULTS: Forty-nine patients (21.7%) had distant recurrences, which occurred most frequently in the liver (87.7%). In a multivariate analysis, local radiotherapy improved RFS among patients with multiple recurrence risk factors relative to excision (not reached vs. 19.0 months, p=0.004). Patients with BRCA1-associated protein-1 (BAP1)–negative primary tumors showed a longer RFS duration after primary treatments, while those with BAP1-negative metastatic tissues had a shorter OS2 compared to those with BAP1-positive tumors, both not statistically insignificance (RFS: not reached vs. 82.0 months, p=0.258; OS2: 15.7 vs. 24.4 months, p=0.216). Male sex (hazard ratio [HR], 3.79; p=0.012), a short RFS (HR, 4.89; p=0.014), and a largest metastatic tumor linear diameter ≥ 45 mm (HR, 5.48; p=0.017) were found to correlate with worse post-recurrence survival. CONCLUSION: Risk factors could be used to classify uveal melanoma cases and subsequently direct individual treatment strategies. Furthermore, metastasectomy appears to contribute to improved survival outcomes.

Surface Characterization and Platelet Adhesion on Thin Hydrogel Films of Poly(vinyl ether).

Poly(vinyl ether), with short oxyethylene side chains which possess a simple and relatively polar structure, should be a unique candidate for a bioinert material thanks to its solubility in water. On the basis of living cationic copolymerization and subsequent ultraviolet light irradiation, thin films of poly(2-methoxyethyl vinyl ether) with different cross-linking densities were prepared on solid substrates. The films were thickened in water, and the extent was dependent on the cross-linking density. Although the surface chemistry and aggregation states were almost identical to one another, the stiffness, or the softness, of the outermost region in the film was strongly dependent on the cross-linking density. That is, the interface between polymer and water became thicker, or more diffused, with decreasing cross-linking density. The blood compatibility based on the platelet adhesion on to the hydrogel films was better for a more diffused interface.

Gelatin-Polyaniline Composite Nanofibers Enhanced Excitation-Contraction Coupling System Maturation in Myotubes.

In this study, composite gelatin-polyaniline (PANI) nanofibers doped with camphorsulfonic acid (CSA) were fabricated by electrospinning and used as substrates to culture C2C12 myoblast cells. We observed enhanced myotube formation on composite gelatin-PANI nanofibers compared to gelatin nanofibers, concomitantly with enhanced myotube maturation. Thus, in myotubes, intracellular organization, colocalization of the dihydropyridine receptor (DHPR) and ryanodine receptor (RyR), expression of genes correlated to the excitation-contraction (E-C) coupling apparatus, calcium transients, and myotube contractibility were increased. Such composite material scaffolds combining topographical and electrically conductive cues may be useful to direct skeletal muscle cell organization and to improve cellular maturation, functionality, and tissue formation.

Depth-resolved local conformation and thermal relaxation of polystyrene near substrate interface.

By means of sum-frequency generation spectroscopy, we report a depth-resolved measurement of the local conformation and chain relaxation of polystyrene (hPS) located at different distances from the quartz interface. To control the distance from the quartz interface, deuterated polystyrene (dPS) layers with thicknesses of 3.4, 7.5, and 20 nm were coated on the quartz substrates. The hPS chains in direct contact with the substrate surface predominantly orient their phenyl rings in a direction normal to the substrate. This conformation was found to be barely relaxed when the film was annealed for 24 h at 423 K, higher than the bulk glass transition temperature. In contrast, for the hPS chains supported on the dPS layer, the orientation of phenyl rings of hPS became weaker with the annealing and this trend was more significant with increasing distance from the quartz substrate. In particular, the orientation of phenyl rings of hPS after annealing vanished at a distance of 20 nm. These results might provide an important evidence of the difference in the relaxation dynamics of the PS chains located at different distances from the quartz interface.

House Fly (Musca domestica L.) Attraction to Insect Honeydew.

House flies are of major concern as vectors of food-borne pathogens to food crops. House flies are common pests on cattle feedlots and dairies, where they develop in and feed on animal waste. By contacting animal waste, house flies can acquire human pathogenic bacteria such as Escherichia coli and Salmonella spp., in addition to other bacteria, viruses, or parasites that may infect humans and animals. The subsequent dispersal of house flies from animal facilities to nearby agricultural fields containing food crops may lead to pre-harvest food contamination with these pathogens. We hypothesized that odors from honeydew, the sugary excreta produced by sucking insects feeding on crops, or molds and fungi growing on honeydew, may attract house flies, thereby increasing the risk of food crop contamination. House fly attraction to honeydew-contaminated plant material was evaluated using a laboratory bioassay. House flies were attracted to the following plant-pest-honeydew combinations: citrus mealybug on squash fruit, pea aphid on faba bean plants, whitefly on navel orange and grapefruit leaves, and combined citrus mealybug and cottony cushion scale on mandarin orange leaves. House flies were not attracted to field-collected samples of lerp psyllids on eucalyptus plants or aphids on crepe myrtle leaves. Fungi associated with field-collected honeydews were isolated and identified for further study as possible emitters of volatiles attractive to house flies. Two fungal species, Aureobasidium pullulans and Cladosporium cladosporioides, were repeatedly isolated from field-collected honeydew samples. Both fungal species were grown in potato dextrose enrichment broth and house fly attraction to volatiles from these fungal cultures was evaluated. House flies were attracted to odors from A. pullulans cultures but not to those of C. cladosporioides. Identification of specific honeydew odors that are attractive to house flies could be valuable for the development of improved house fly baits for management of this pest species.

Nano-palpation AFM and its quantitative mechanical property mapping.

We review nano-palpation atomic force microscopy, which offers quantitative mechanical property mapping especially for soft materials. The method measures force-deformation curves on the surfaces of soft materials. The emphasis is placed on how both Hertzian and Derjaguin-Muller-Toporov contact mechanics fail to reproduce the experimental curves and, alternatively, how the Johnson-Kendall-Roberts model does. We also describe the force-volume technique for obtaining a two-dimensional map of mechanical properties, such as the elastic modulus and adhesive energy, based on the above-mentioned analysis. Finally, we conclude with several counterpart measurements, which describe the viscoelastic nature of soft materials, and give examples, including vulcanized isoprene rubber and the current status of ISO standardization.

Comparison of Melanoma Subtypes among Korean Patients by Morphologic Features and Ultraviolet Exposure

BACKGROUND: Genetic alterations have been identified in melanomas according to different levels of sun exposure. Whereas the conventional morphology-based classification provides a clue for tumor growth and prognosis, the new classification by genetic alterations offers a basis for targeted therapy. OBJECTIVE: The purpose of this study is to demonstrate the biological behavior of melanoma subtypes and compare the two classifications in the Korean population. METHODS: A retrospective chart review was performed on patients found to have malignant melanoma in Severance Hospital from 2005 to 2012. Age, sex, location of the tumor, histologic subtype, tumor depth, ulceration, lymph node invasion, visceral organ metastasis, and overall survival were evaluated. RESULTS: Of the 206 cases, the most common type was acral melanoma (n=94, 45.6%), followed by nonchronic sun damage-induced melanoma (n=43, 20.9%), and mucosal melanoma (n=40, 19.4%). Twenty-one patients (10.2%) had the chronic sun-damaged type, whereas eight patients (3.9%) had tumors of unknown primary origin. Lentigo maligna melanoma was newly classified as the chronic sun-damaged type, and acral lentiginous melanoma as the acral type. More than half of the superficial spreading melanomas were newly grouped as nonchronic sun-damaged melanomas, whereas nodular melanoma was rather evenly distributed. CONCLUSION: The distribution of melanomas was largely similar in both the morphology-based and sun exposure-based classifications, and in both classifications, mucosal melanoma had the worst 5-year survival owing to its tumor thickness and advanced stage at the time of diagnosis.

Indirect effects of temperature on stink bug fitness, via maintenance of gut-associated symbionts.

Impacts of climate change on organisms are already apparent, with effects ranging from the individual to ecosystem scales. For organisms engaged in mutualisms, climate may affect population performance directly or indirectly through mediated effects on their mutualists. We tested this hypothesis for two stink bugs, Acrosternum hilare and Murgantia histrionica, and their gut-associated symbionts. We reared these species at two constant temperatures, 25 and 30 degrees C, and monitored population demographic parameters and the presence of gut-associated symbionts with diagnostic PCR primer sets. Both stink bugs lost their respective gut symbionts within two generations at 30 degrees C. In addition, the insect survivorship and reproductive rates of both A. hilare and M. histrionica at 30 degrees C were lower than at 25 degrees C. Other demographic parameters also indicated a decrease in overall insect fitness at the high temperature. Collectively our data showed that the decrease in host fitness was coupled with, and potentially mediated by, symbiont loss at 30 degrees C. This work illustrates the need to better understand the biology of animal-symbiont associations and the consequences of local climate for the dynamics of these interactions.

In vitro evaluation of the efficacy and safety of the intelliclean system: interproximal biofilm removal and dentin substrate wear.

The ability of a novel integrated power toothbrush and liquid-toothpaste dispensing system, the IntelliClean System from Sonicare and Crest, to remove interproximal biofilm while being gentle on dentin was studied using two in vitro models. Interproximal biofilm removal was assessed via a complex multispecies biofilm grown on hydroxyapatite disks and then placed interproximally in a typodont section modeling a typical oral environment. The power toothbrush in the prototype integrated system was compared to a traditional rotating/oscillating power toothbrush, the Oral-B ProfessionalCare 7000, and a nonbrushing control through a series of 3 experiments with a total of 36 replicates per arm. The amount of interproximal plaque biofilm removed by the integrated system toothbrush was significantly greater than that removed by the rotating/oscillating toothbrush and by the nonbrushing control (P < .05). In the second model, dentin substrate wear was measured using profilometry after the brushing of dentin sections (3 mm x 10 mm) for a period equivalent to 2 years of typical product use. Dentin wear associated with the use of the prototype integrated system with standard and whitening versions of the liquid toothpaste was compared to that of a rotating/oscillating power toothbrush and a manual toothbrush with the standard version of the prototype liquid toothpaste, with a total of 12 replicates per arm. The amount of dentin wear induced by the integrated system with either the standard or whitening liquid toothpaste was significantly less than the wear from the rotating/oscillating power toothbrush and the manual toothbrush with the standard liquid toothpaste (P < .05).