Roadmap For The Expression Of Canonical and Extended Endocannabinoid System Receptors and Proteins in Peripheral Organs of Preclinical Animal Models

The endocannabinoid system is widely expressed throughout the body and is comprised of receptors, ligands, and enzymes that maintain metabolic, immune, and reproductive homeostasis. Increasing interest in the endocannabinoid system has arisen due to these physiologic roles, policy changes leading to more widespread recreational use, and the therapeutic potential of Cannabis and phytocannabinoids. Rodents have been the primary preclinical model of focus due to their relative low cost, short gestational period, genetic manipulation strategies, and gold-standard behavioral tests. However, the potential for lack of clinical translation to non-human primates and humans is high as cross-species comparisons of the endocannabinoid system has not been evaluated. To bridge this gap in knowledge, we evaluate the relative gene expression of 14 canonical and extended endocannabinoid receptors in seven peripheral organs of C57/BL6 mice, Sprague-Dawley rats, and non-human primate rhesus macaques. Notably, we identify species- and organ-specific heterogeneity in endocannabinoid receptor distribution where there is surprisingly limited overlap among the preclinical models. Importantly, we determined there were only five receptors (CB2, GPR18, GPR55, TRPV2, and FAAH) that had identical expression patterns in mice, rats, and rhesus macaques. Our findings demonstrate a critical, yet previously unappreciated, contributor to challenges of rigor and reproducibility in the cannabinoid field, which has profound implications in hampering progress in understanding the complexity of the endocannabinoid system and development of cannabinoid-based therapies.

Compositional shifts within the denture-associated bacteriome in pneumonia - an analytical cross-sectional study

Introduction. Bacterial pneumonia is a common cause of morbidity and mortality in elderly individuals. While the incidence of edentulism is falling, approximately 19 % of the UK population wear a full or partial removable denture. Despite advances in denture biomaterials, the majority of dentures are fabricated using polymethyl-methacrylate. Growing evidence suggests that colonization of the oral cavity by putative respiratory pathogens predisposes individuals to respiratory infection, by translocation of these microorganisms along the respiratory tract.Hypothesis/Gap Statement. We hypothesized that denture surfaces provide a susceptible colonization site for putative respiratory pathogens, and thus could increase pneumonia risk in susceptible individuals.Aim. This study aimed to characterize the bacterial community composition of denture-wearers in respiratory health compared with individuals with a confirmed diagnosis of pneumonia.Methodology. This was an analytical cross-sectional study, comparing frail elderly individuals without respiratory infection (n=35) to hospitalized patients with pneumonia (n=26). The primary outcome was the relative abundance of putative respiratory pathogens identified by 16S rRNA metataxonomic sequencing, with quantitative PCR used to identified Streptococcus pneumoniae.Results. There was a statistically significant increase in the overall relative abundance of putative respiratory pathogens (P<0.0001), with a greater than 20-fold increase in the bioburden of these microorganisms. In keeping with these findings, there were significant shifts in bacterial community diversity (Chao index, P=0.0003) and richness (Inverse Simpson index P<0.0001) in the denture-associated microbiota of pneumonia patients compared with control subjects.Conclusion. Within the limitations of this study, our evidence supports the role of denture acrylic biomaterials as a potential colonization site for putative respiratory pathogens, which may lead to an increased risk of pneumonia in susceptible individuals. These findings support prior observational studies which have found denture-wearers to be at increased risk of respiratory infection. Further research is needed to confirm the sequence of colonization and translocation to examine potential causal relationships.

Network analysis of nitrate-sensitive oral microbiome reveals interactions with cognitive function and cardiovascular health across dietary interventions

Many oral bacteria reduce inorganic nitrate, a natural part of a vegetable-rich diet, into nitrite that acts as a precursor to nitric oxide, a regulator of vascular tone and neurotransmission. Aging is hallmarked by reduced nitric oxide production with associated detriments to cardiovascular and cognitive function. This study applied a systems-level bacterial co-occurrence network analysis across 10-day dietary nitrate and placebo interventions to test the stability of relationships between physiological and cognitive traits and clusters of co-occurring oral bacteria in older people. Relative abundances of Proteobacteria increased, while Bacteroidetes, Firmicutes and Fusobacteria decreased after nitrate supplementation. Two distinct microbiome modules of co-occurring bacteria, that were sensitive to nitrate supplementation, showed stable relationships with cardiovascular (Rothia-Streptococcus) and cognitive (Neisseria-Haemophilus) indices of health across both dietary conditions. A microbiome module (Prevotella-Veillonella) that has been associated with pro-inflammatory metabolism was diminished after nitrate supplementation, including a decrease in relative abundance of pathogenic Clostridium difficile. These nitrate-sensitive oral microbiome modules are proposed as potential pre- and probiotic targets to ameliorate age-induced impairments in cardiovascular and cognitive health.

NIDCD/VA Hearing Aid Clinical Trial and Follow-Up: Background

This report provides background regarding the Long Term Follow-Up of Patients in the NIDCD/VA Hearing Aid Clinical Trial study and serves as an introduction to the detailed reports that follow in this issue of Journal of the American Academy of Audiology. The authors investigated five- to seven-year benefit/satisfaction in participants from the original NIDCD/VA Hearing Aid Clinical Trial. The new study was designed to investigate current use of the original study hearing aids, to compare changes in selected audiological measures, and to assess possible predictors of long-term hearing aid use. The outcome measures included estimates of speech intelligibility in quiet and noise, self-reported patterns of hearing aid usage, self-reported estimates of activity limitations and quality-of-life issues, estimates of hearing aid satisfaction, and self-reported hearing aid benefit. Overall, the short-term benefits of hearing aid use observed during the original trial were noted to persist in the long term. Este reporte suministra información relacionada con el Seguimiento a Largo Plazo de los Pacientes del Estudio Clínico de Auxiliares Auditivos del NIDCD/VA, y sirve como una introducción de los reportes detallados que siguen a continuación en esta edición del Journal de la Academia Americana de Audiología. Los autores investigaron por cinco a siete años la satisfacción/beneficio en los participantes del Estudio Clínico de Auxiliares Auditivos del NIDCD/VA original. El nuevo estudio fue designado para investigar el uso actual de los auxiliares auditivos (AA) originales del estudio, para comparar cambios en las medidas audiológicas seleccionadas, y evaluar posibles elementos de predicción a largo plazo en el uso de AA. Las medidas de resultado incluyeron estimados de la inteligibilidad del lenguaje en silencio y en ruido, patrones auto-reportados de uso del AA, estimaciones auto-reportadas de limitación en la actividad y en asuntos de calidad de vida, estimaciones de satisfacción en el uso del AA y auto-reportes de beneficios con el AA. Globalmente, los beneficios a corto plazo del uso de auxiliares auditivos durante el estudio original persistieron en el largo plazo.

Subjective Measures of Hearing Aid Benefit and Satisfaction in the NIDCD/VA Follow-Up Study

Perceived benefit, satisfaction, and hearing aid use patterns were measured in a follow-up study to a large-scale multi-site clinical trial conducted in 1996–97. Measures included the Hearing Aid Status Questionnaire, the Profile of Hearing Aid Benefit, the Glasgow Hearing Aid Benefit Profile, the Satisfaction with Amplification in Daily Life, and the International Outcome Inventory for Hearing Aids. On the Profile of Hearing Aid Benefit, hearing aid users indicated more unaided difficulty in easy listening situations and less aided benefit in more difficult listening situations compared to the original study. Subjects who no longer used hearing aids indicated less difficulty in unaided situations. All measures indicated significant long-term subjective benefit and satisfaction with hearing aids. Although understanding speech in noise or in group situations continues to be problematic, subjects reported wearing their hearing aids almost all of the time in both easy and difficult listening situations. Se midió el beneficio y la satisfacción del paciente y los patrones de uso del auxiliar auditivo (AA) en un estudio de seguimiento de un estudio clínico, multicéntrico, a larga escala, conducido en 1996–97. Las mediciones incluyeron el Cuestionario del Estado de Uso del Auxiliar Auditivo, el Perfil de Beneficio del Auxiliar Auditivo, El Perfil de Glasgow de Beneficio del Auxiliar Auditivo, la Prueba de Satisfacción con la Amplificación en la Vida Diaria, y el Inventario Internacional de Resultados de Auxiliares Auditivos. En el Perfil de Beneficio de Auxiliares Auditivos, los usuarios de AA indicaron más dificultad sin amplificación en situaciones fáciles de escucha y menor beneficio con amplificación en situaciones difíciles de escucha, comparado con el estudio original. Los sujetos que no volvieron a usar sus AA indicaron menos dificultad en situaciones no amplificadas. Todas las medidas indicaron una satisfacción y un beneficio subjetivo y significativo a largo plazo, con los AA. Aunque entender el lenguaje en ruido o en situaciones grupales continúa siendo problemático, los sujetos reportaron la utilización de sus AA casi todo el tiempo, tanto en situaciones fáciles como difíciles de escucha.

Speech-Recognition Performance after Long-Term Hearing Aid Use

Larson et al (2000) reported the findings of a multicenter, NIDCD/VA clinical trial that compared hearing aid performance for three output limiting circuits in 360 adults with symmetrical sensorineural hearing loss. The current study was undertaken to examine long-term hearing aid benefit in this same group of participants following five to six years of hearing aid use. The speech-recognition portion of the follow-up study enrolled 108 participants from the original study, 85% of whom were current hearing aid users and 15% of whom had not worn hearing aids during the past month (nonusers). Recognition performance in sound field on the NU-6 (quiet at 62 dB SPL) and the CST (quiet at 74 dB SPL and with -3 and 3 dB signal-to-babble ratios [S/B] at 62 and 74 dB SPL) was measured unaided and aided whenever possible. Speech-recognition abilities decreased significantly since the original study. Speech-recognition decrements were observed regardless of the speech materials (NU-6 and CST), test condition (quiet and noise), S/B (-3 and 3 dB), or stimulus level (62 and 74 dB SPL). Despite decreases in speech recognition, hearing aid benefit remained largely unchanged since the original study; aided performance exceeded unaided performance regardless of presentation level or noise condition. As in the original study, the relations among stimulus level, S/B, and speech-recognition performance were complex. Larson y col. (2000) reportaron los hallazgos de un estudio clínicos multicéntrico del NIDCD/VA que comparó el desempeño en el uso de auxiliares auditivos (AA) con tres circuitos de limitación de la salida, en 360 adultos con pérdida auditiva sensorineural simétrica. El estudio actual fue conducido para examinar el beneficio a largo plazo del AA en el mismo grupo de participantes, luego de cinco a seis años de utilización del AA. La porción de reconocimiento de lenguaje del estudio de seguimiento involucró a 108 participantes del estudio original, 85% de los cuáles eran actuales usuarios de AA y 15% que no habían usado AA durante el mes anterior (no usuarios). El desempeño en reconocimiento del lenguaje en campo sonoro con el NU-6 (en silencio a 62 dB SPL) y con el CST (en silencio a 74 dB SPL, y con tasas de señal/balbuceo de -3 y +3 dB [S&B] a 62 y 74 dB SPL), fue medido con y sin amplificación cuando resultó posible. Las habilidades de reconocimiento del lenguaje habían disminuido significativamente desde el estudio original. Se observó reducción en el reconocimiento del lenguaje independientemente del material logoaudiométrico (NU-6 y CST), las condiciones de la prueba (en silencio o en ruido), S/B (-3 y +3 dB), o la intensidad del estímulo (62 y 74 dB SPL). A pesar de la disminución en el reconocimiento del lenguaje, el beneficio del AA permaneció sin cambios en relación al estudio original; el desempeño con amplificación superó el desempeño sin amplificación sin importar la intensidad de la presentación o las condiciones de ruido. Al igual que en el estudio original, las relaciones entre el nivel de estímulo, la S/B y el desempeño en el reconocimiento de lenguaje fueron complejas.

NIDCD/VA Hearing Aid Clinical Trial and Follow-Up: Coupler and Real-Ear Measurement

A total of 190 individuals participated in a clinical visit during the Cooperative Studies Program (CSP) 418-A Long Term Follow-Up Study. Of this cohort, 158 participants were considered current hearing aid users, and 32 were non–hearing aid users. Of the current hearing aid users, 81 were still using their original 418 study devices, and 77 had acquired new hearing aids. Coupler and real ear measurements were completed on all available hearing aids. Results showed that study aids had remained relatively stable over the six years between CSP 418 and CSP 418-A. On average, these hearing aid wearers preferred use gain settings that were 6–9 dB less than current NAL-RP insertion gain targets. Mean real ear insertion gain (REIG) was comparable to the mean real ear insertion gain of the same participants in the original study, and users did not tend to increase gain as hearing decreased. Real ear saturation responses (RESR) remained unchanged. Loudness discomfort levels (LDL) obtained during 418-A were significantly lower than LDLs obtained on those same participants at both the initial and final visits in the previous study. Un total de 190 individuos participaron de la visita clínica durante el Estudio de Seguimiento a Largo Plazo 418-A del Programa de Estudios Cooperativos (CSP). De esta cohorte, 158 participantes se consideraron usuarios actuales de auxiliares auditivos (AA), y 32 se consideraron no usuarios de AA. De los usuarios actuales de AA, 81 aún utilizaban sus dispositivos 418 del estudio, y 77 había adquiridos nuevos AA. Se completaron mediciones de acoplador y de oído real para todos los AA disponibles. Los resultados mostraron que los AA del estudio había permanecido relativamente estables en los seis años entre el CSP 418 y el CSP 418-A. En promedio, estos usuarios de AA prefirieron el uso de ajustes de ganancia que estaban 6-9 dB por debajo de las metas actuales de ganancia de inserción del NAL-RP. La ganancia media de inserción de oído real (REIG) fue comparable con la ganancia media de inserción de oído real de los mismos participantes en el estudio original, y los sujetos no tendieron a incrementar la ganancia conforme la audición se deterioró. Las respuestas de saturación de oído real (RESR) se mantuvieron sin cambio. Los niveles de incomodidad a la intensidad subjetiva (LDL) obtenidos durante el 419-A fueron significativamente más bajos que los LDL obtenidos en los mismos participantes, tanto en la visita inicial como final del estudio previo.

Indigenous Microbiota Protects against Inflammation-Induced Osteonecrosis

Medication-related osteonecrosis of the jaw (MRONJ) is a rare intraoral lesion that occurs in patients undergoing long-term and/or high-dose therapy with nitrogen-containing bisphosphonates, a RANKL inhibitor, antiangiogenic agents, or mTOR inhibitors. The presence of pathogenic bacteria is highly associated with advanced stages of MRONJ lesions; however, the exact role of indigenous microbes in MRONJ development is unknown. Here, we report that the normal oral flora in mice protects against inflammation-induced osteonecrosis. In mice that developed osteonecrosis following tooth extraction, there was increased bacterial infiltration when compared with healed controls. Antibiotic-mediated oral dysbiosis led to a local inhibition of bone resorption in the presence of ligature-induced periodontitis (LIP). There was no significant difference in empty lacunae, necrotic bone formation, osteoclast number, and surface area in antibiotic-treated as compared with conventionally colonized mice following extraction of healthy teeth after zoledronic acid infusions. However, extraction of LIP teeth led to increased empty lacunae, necrotic bone, and osteoclast surface area in antibiotic- and zoledronic acid-treated mice as compared with conventionally colonized mice. Our findings suggest that the presence of the indigenous microbiota protects against LIP-induced osteonecrosis.

Specimen Collection for Translational Studies in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder characterized by painful nodules, sinus tracts, and scars occurring predominantly in intertriginous regions. The prevalence of HS is currently 0.053-4%, with a predominance in African-American women and has been linked to low socioeconomic status. The majority of the reported literature is  retrospective, population based, epidemiologic studies. In this regard, there is a need to establish a repository of biospecimens, which represent appropriate gender and racial demographics amongst HS patients. These efforts will diminish knowledge gaps in understanding the disease pathophysiology. Hence, we sought to outline a step-by-step protocol detailing how we established our HS biobank to facilitate the formation of other HS tissue banks. Equipping researchers with carefully detailed processes for collection of HS specimens would accelerate the accumulation of well-organized human biological material. Over time, the scientific community will have access to a broad range of HS tissue biospecimens, ultimately leading to more rigorous basic and translational research. Moreover, an improved understanding of the pathophysiology is necessary for the discovery of novel therapies for this debilitating disease. We aim to provide high impact translational research methodology for cutaneous biology research and foster multidisciplinary collaboration and advancement of our understanding of cutaneous diseases.

Molecular community profiling of the bacterial microbiota associated with denture-related stomatitis

Denture-associated stomatitis (DS) affects over two-thirds of denture-wearers. DS presents as erythema of the palatal mucosa in areas where denture-surface associated polymicrobial biofilms containing the fungus Candida albicans exist. The contribution of the oral bacterial microbiota toward the infection is unknown. Therefore, this study characterised the bacterial microbiota of sites within the oral cavity to identify potential associations with occurrence of DS. Denture-wearing patients were recruited (denture stomatitis (DS) n = 8; non-denture stomatitis (NoDS) n = 11) and the oral bacterial microbiota of the tongue, palate and denture-fitting surface was characterised using next-generation sequencing. Operational taxonomic units (OTUs) were identified to bacterial genera and species, and presence/absence and relative abundances were examined. A significant (P = 0.007) decrease in the number of OTUs and thus, diversity of the microbiota was observed in tongue samples of DS patients (vs non-DS). The microbiota of denture-fitting surfaces and palatal mucosae were similar. Large differences in the abundance of bacterial genera and species were observed at each sample site, and unique presence/absence of bacteria was noted. Presence/absence and relative abundance of specific bacteria associated with DS warrants further in vitro and in vivo evaluation, particularly as our previous work has shown C. albicans virulence factor modulation by oral bacteria.

Modulation of Candida albicans virulence in in vitro biofilms by oral bacteria

Candida‐associated denture stomatitis presents as erythema of the palatal mucosa and is caused by biofilms containing the fungus Candida albicans that co‐reside with oral bacteria on the denture‐fitting surface. This study aimed to assess the effect of several frequently encountered oral bacteria on the expression of C. albicans virulence factors in in vitro polymicrobial biofilms. Biofilms containing C. albicans and selected bacterial species were grown on denture acrylic, and analysed by microscopy and by qPCR for expression of putative virulence genes. Candida albicans‐only biofilms showed limited hyphal production. Hyphal development was significantly (P < 0·001) increased when biofilms also contained four species of oral bacteria (Streptococcus sanguinis, Streptococcus gordonii, Actinomyces odontolyticus and Actinomyces viscosus), as was the expression of virulence genes (P < 0·05). Importantly, inclusion of Porphyromonas gingivalis in the biofilm consortium resulted in significant (P < 0·05) inhibition of virulence gene expression and production of hyphae. The in vitro expression of C. albicans virulence factors was modulated in polymicrobial biofilms. The complexity of this modulation was highlighted by the reversal of effects following introduction of a single bacterial species into a biofilm community.

Significance and Impact of the Study

The impact of individual bacterial species on Candida albicans virulence highlights both the complexity of predicting infection mediated by polymicrobial communities and the potential for management through pro‐ or prebiotic therapy. The possibility to selectively modulate microbial virulence by addition of, or treatment with pro‐ or prebiotics avoids the use of conventional antimicrobial compounds, thus reducing the contribution to potential drug resistance. Understanding which bacterial species modulate virulence, and the mechanisms by which this occurs, particularly in biofilms, provides excellent foundations for further research questions, and the potential for novel clinical interventions.

Nitrate-responsive oral microbiome modulates nitric oxide homeostasis and blood pressure in humans

Imbalances in the oral microbial community have been associated with reduced cardiovascular and metabolic health. A possible mechanism linking the oral microbiota to health is the nitrate (NO₃^-)-nitrite (NO₂^-)-nitric oxide (NO) pathway, which relies on oral bacteria to reduce NO₃^- to NO₂^-. NO (generated from both NO₂^- and L-arginine) regulates vascular endothelial function and therefore blood pressure (BP). By sequencing bacterial 16S rRNA genes we examined the relationships between the oral microbiome and physiological indices of NO bioavailability and possible changes in these variables following 10 days of NO₃^- (12 mmol/d) and placebo supplementation in young (18-22 yrs) and old (70-79 yrs) normotensive humans (n = 18). NO₃^- supplementation altered the salivary microbiome compared to placebo by increasing the relative abundance of Proteobacteria (+225%) and decreasing the relative abundance of Bacteroidetes (-46%; P < 0.05). After NO₃^-supplementation the relative abundances of Rothia (+127%) and Neisseria (+351%) were greater, and Prevotella (-60%) and Veillonella (-65%) were lower than in the placebo condition (all P < 0.05). NO₃^- supplementation increased plasma concentration of NO₂^- and reduced systemic blood pressure in old (70-79 yrs), but not young (18-22 yrs), participants. High abundances of Rothia and Neisseria and low abundances of Prevotella and Veillonella were correlated with greater increases in plasma [NO₂^-] in response to NO₃^- supplementation. The current findings indicate that the oral microbiome is malleable to change with increased dietary intake of inorganic NO₃^-, and that diet-induced changes in the oral microbial community are related to indices of NO homeostasis and vascular health in vivo.

Diagnosis and management of oral candidosis

Candida is a fungus (yeast) that is generally regarded as a normal and harmless member of the oral microbiome in humans. Should host defences against these commensals be compromised in any way then Candida can cause clinical signs and symptoms, which manifest as distinct forms of oral candidosis (candidiasis). Candida albicans is the most frequently isolated candidal species from the oral cavity, although a range of non-C. albicans Candida species are being increasingly encountered. The basic principle of the management of candidosis is to identify and eliminate any underlying host predisposing factor. However, in many cases, antifungal therapy will also be required as part of initial management. This article will provide an overview of the isolation, identification and pathogenicity of Candida species encountered within the mouth and relate these to clinical management of oral candidosis.

Denture-associated biofilm infection in three-dimensional oral mucosal tissue models

Purpose

In vitro analyses of virulence, pathogenicity and associated host cell responses are important components in the study of biofilm infections. The Candida-related infection, denture-associated oral candidosis, affects up to 60 % of denture wearers and manifests as inflammation of palatal tissues contacting the denture-fitting surface. Commercially available three-dimensional tissue models can be used to study infection, but their use is limited for many academic research institutions, primarily because of the substantial purchase costs. The aim of this study was to develop and evaluate the use of in vitro tissue models to assess infections by biofilms on acrylic surfaces through tissue damage and Candida albicans virulence gene expression.

Methodology

In vitro models were compared against commercially available tissue equivalents (keratinocyte-only, SkinEthic; full-thickness, MatTek Corporation). An in vitro keratinocyte-only tissue was produced using a cancer-derived cell line, TR146, and a full-thickness model incorporating primary fibroblasts and immortalised normal oral keratinocytes was also generated. The in vitro full-thickness tissues incorporated keratinocytes and fibroblasts, and have potential for future further development and analysis.

Results

Following polymicrobial infection with biofilms on acrylic surfaces, both in-house developed models were shown to provide equivalent results to the SkinEthic and MatTek models in terms of tissue damage: a significant (P<0.05) increase in LDH activity for mixed species biofilms compared to uninfected control, and no significant difference (P>0.05) in the expression of most C. albicans virulence genes when comparing tissue models of the same type.

Conclusion

Our results confirm the feasibility and suitability of using these alternative in vitro tissue models for such analyses.

Characterisation of the dimorphic Deladenus beddingi n. sp. and its associated woodwasp and fungus

A new dimorphic species of Deladenus isolated from Sirex californicus from Washington, USA, is described as D. beddingi n. sp. Evolutionary relationships of the new species with other Deladenus species were assessed using multilocus sequencing. Phylogenetic relationships derived from analyses of mtCO1 and ITS showed D. beddingi n. sp. to be genetically distinct from other North American Deladenus parasitising Sirex. Molecular analyses indicated that D. beddingi n. sp. is a member of the D. siricidicola species complex, which also includes undescribed native Deladenus from Sirex cyaneus and S. nitidus, and D. siricidicola from S. noctilio. Mycophagous adults were characterised by the position of the excretory pore, which was located 32 (22-52) and 48 (38-69) μm anterior to the hemizonid in mycophagous females and males, respectively. Typologically, the new species is most similar to D. siricidicola, D. proximus and D. nitobei, but can be distinguished from these species by several morphometric traits, including the value of ratios a, b, c of the mycophagous females and males, ratio b of the infective females, and the morphology of the tail of the mycophagous females, which is narrow and gradually tapering. This novel nematode species feeds on the fungus Amylostereum chailletii during its mycophagous phase. Experimental results showed very little reproduction by D. beddingi n. sp. when feeding on A. areolatum compared to robust reproduction when feeding on A. chailletii.

Industrial hemp as a potential bioenergy crop in comparison with kenaf, switchgrass and biomass sorghum

This study takes combined field trial, lab experiment, and economic analysis approaches to evaluate the potential of industrial hemp in comparison with kenaf, switchgrass and biomass sorghum. Agronomy data suggest that the per hectare yield (5437kg) of industrial hemp stem alone was at a similar level with switchgrass and sorghum; while the hemp plants require reduced inputs. Field trial also showed that ∼1230kg/ha hemp grain can be harvested in addition to stems. Results show a predicted ethanol yield of ∼82gallons/dry ton hemp stems, which is comparable to the other three tested feedstocks. A comparative cost analysis indicates that industrial hemp could generate higher per hectare gross profit than the other crops if both hemp grains and biofuels from hemp stem were counted. These combined evaluation results demonstrate that industrial hemp has great potential to become a promising regional commodity crop for producing both biofuels and value-added products.

Endotracheal tubes and fluid aspiration: an in vitro evaluation of new cuff technologies

BACKGROUND

Aspiration of subglottic secretions past the endotracheal tube (ETT) cuff is a prerequisite for developing ventilator-associated pneumonia (VAP). Subglottic secretion drainage (SSD) ETTs reduce aspiration of subglottic secretions and have demonstrated lower VAP rates. We compared the performance of seven SSD ETTs against a non-SSD ETT in preventing aspiration below inflated cuffs.

METHODS

ETTs were positioned vertically in 2 cm diameter cylinders. Four ml of a standard microbial suspension was added above inflated cuffs. After 1 h, aspiration was measured and ETTs demonstrating no leakage were subjected to rotational movement and evaluation over 24 h. Collected aspirated fluid was used to inoculate agar media and incubated aerobically at 37 °C for 24 h. The aspiration rate, volume and number of microorganisms that leaked past the cuff was measured. Experiments were repeated (×10) for each type of ETT, with new ETTs used for each repeat. Best performing ETTs were then tested in five different cylinder diameters (1.6, 1.8, 2.0, 2.2 and 2.4 cm). Experiments were repeated as above using sterile water. Volume and time taken for aspiration past the cuff was measured. Experiments were repeated (×10) for each type of ETT. Results were analysed using non-parametric tests for repeated measures.

RESULTS

The PneuX ETT prevented aspiration past the cuff in all experiments. All other ETTs allowed aspiration, with considerable variability in performance. The PneuX ETT was statistically superior in reducing aspiration compared to the SealGuard (p < 0.009), KimVent (p < 0.002), TaperGuard (p < 0.004), Lanz (p < 0.001), ISIS (p < 0.001), SACETT (p < 0.001) and Soft Seal (p < 0.001) ETTs. Of the 4 ETTs tested in differing cylinder sizes, the PneuX significantly reduced aspiration across the range of diameters compared to the SealGuard (p < 0.0001), TaperGuard (p < 0.0001) and KimVent (p < 0.0001) ETTs.

CONCLUSIONS

ETTs showed substantial variation in fluid aspiration, relating to cuff material and design. Variability in performance was likely due to the random manner in which involutional folds form in the inflated ETT cuff. The PneuX ETT was the only ETT able to consistently prevent aspiration past the cuff in all experiments.

Community analysis of dental plaque and endotracheal tube biofilms from mechanically ventilated patients

PURPOSE

Mechanically ventilated patients are at risk for developing ventilator-associated pneumonia, and it has been reported that dental plaque provides a reservoir of respiratory pathogens that may aspirate to the lungs and endotracheal tube (ETT) biofilms. For the first time, metataxonomics was used to simultaneously characterize the microbiome of dental plaque, ETTs, and non-directed bronchial lavages (NBLs) in mechanically ventilated patients to determine similarities in respective microbial communities and therefore likely associations.

MATERIAL AND METHODS

Bacterial 16S rRNA gene sequences from 34 samples of dental plaque, NBLs, and ETTs from 12 adult mechanically ventilated patients were analyzed.

RESULTS

No significant differences in the microbial communities of these samples were evident. Detected bacteria were primarily oral species (e.g., Fusobacterium nucleatum, Streptococcus salivarius, Prevotella melaninogenica) with respiratory pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcuspneumoniae, and Haemophilus influenzae) also in high abundance.

CONCLUSION

The high similarity between the microbiomes of dental plaque, NBLs, and ETTs suggests that the oral cavity is indeed an important site involved in microbial aspiration to the lower airway and ETT. As such, maintenance of good oral hygiene is likely to be highly important in limiting aspiration of bacteria in this vulnerable patient group.

Comparison of foam swabs and toothbrushes as oral hygiene interventions in mechanically ventilated patients: a randomised split mouth study

Introduction

During critical illness, dental plaque may serve as a reservoir of respiratory pathogens. This study compared the effectiveness of toothbrushing with a small-headed toothbrush or a foam-headed swab in mechanically ventilated patients.

Methods

This was a randomised, assessor-blinded, split-mouth trial, performed at a single critical care unit. Adult, orally intubated patients with >20 teeth, where >24 hours of mechanical ventilation was expected were included. Teeth were cleaned 12-hourly using a foam swab or toothbrush (each randomly assigned to one side of the mouth). Cleaning efficacy was based on plaque scores, gingival index and microbial plaque counts.

Results

High initial plaque (mean=2.1 (SD 0.45)) and gingival (mean=2.0 (SD 0.54)) scores were recorded for 21 patients. A significant reduction compared with initial plaque index occurred using both toothbrushes (mean change=−1.26, 95% CI −1.57 to −0.95; p<0.001) and foam swabs (mean change=−1.28, 95% CI −1.54 to −1.01; p<0.001). There was significant reduction in gingival index over time using toothbrushes (mean change=−0.92; 95% CI −1.19 to −0.64; p<0.001) and foam swabs (mean change=−0.85; 95% CI −1.10 to −0.61; p<0.001). Differences between cleaning methods were not statistically significant (p=0.12 for change in gingival index; p=0.24 for change in plaque index). There was no significant change in bacterial dental plaque counts between toothbrushing (mean change 3.7×10⁴ colony-forming units (CFUs); minimum to maximum (−2.5×10¹⁰ CFUs, 8.7×10⁷ CFUs)) and foam swabs (mean change 9×10⁴ CFUs; minimum to maximum (−3.1×10¹⁰ CFUs, 3.0×10⁷ CFUs)).

Conclusions

Patients admitted to adult intensive care had poor oral health, which improved after brushing with a toothbrush or foam swab. Both interventions were equally effective at removing plaque and reducing gingival inflammation.

Trial registration number

NCT01154257; Pre-results.

Respiratory pathogen colonization of dental plaque, the lower airways, and endotracheal tube biofilms during mechanical ventilation

PURPOSE

In mechanically ventilated patients, the endotracheal tube is an essential interface between the patient and ventilator, but inadvertently, it also facilitates the development of ventilator-associated pneumonia (VAP) by subverting pulmonary host defenses. A number of investigations suggest that bacteria colonizing the oral cavity may be important in the etiology of VAP. The present study evaluated microbial changes that occurred in dental plaque and lower airways of 107 critically ill mechanically ventilated patients.

MATERIALS AND METHODS

Dental plaque and lower airways fluid was collected during the course of mechanical ventilation, with additional samples of dental plaque obtained during the entirety of patients' hospital stay.

RESULTS

A "microbial shift" occurred in dental plaque, with colonization by potential VAP pathogens, namely, Staphylococcus aureus and Pseudomonas aeruginosa in 35 patients. Post-extubation analyses revealed that 70% and 55% of patients whose dental plaque included S aureus and P aeruginosa, respectively, reverted back to having a predominantly normal oral microbiota. Respiratory pathogens were also isolated from the lower airways and within the endotracheal tube biofilms.

CONCLUSIONS

To the best of our knowledge, this is the largest study to date exploring oral microbial changes during both mechanical ventilation and after recovery from critical illness. Based on these findings, it was apparent that during mechanical ventilation, dental plaque represents a source of potential VAP pathogens.

Modulation of Candida albicans virulence by bacterial biofilms on titanium surfaces

Whilst Candida albicans occurs in peri-implant biofilms, its role in peri-implantitis remains unclear. This study therefore examined the virulence of C. albicans in mixed-species biofilms on titanium surfaces. Biofilms of C. albicans (Ca), C. albicans with streptococci (Streptococcus sanguinis, S. mutans) (Ca-Ss-Sm) and those incorporating Porphyromonas gingivalis (Ca-Pg and Ca-Ss-Sm-Pg) were developed. Expression of C. albicans genes associated with adhesion (ALS1, ALS3, HWP1) and hydrolytic enzymes (SAP2, SAP4, SAP6, PLD1) was measured and hyphal production by C. albicans quantified. Compared with Ca biofilms, significant (p<0.05) up-regulation of ALS3, HWP1, SAP2 and SAP6, and hyphal production occurred in biofilms containing streptococci (Ca-Ss-Sm). In Ca-Pg biofilms, down-regulation of HWP1 and SAP4 expression, with reduced hyphal production occurred. Ca-Ss-Sm-Pg biofilms had increased hyphal proportions and up-regulation of ALS3, SAP2 and SAP6. In conclusion, C. albicans expressed virulence factors in biofilms that could contribute to peri-implantitis, but this was dependent on associated bacterial species.

Microbial profiling of dental plaque from mechanically ventilated patients

Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97 % gene similarity cut-off for bacterial species level identifications. A significant ‘microbial shift’ occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection.

A novel in vitro assay for assessing efficacy and toxicity of antifungals using human leukaemic cells infected with Candida albicans

AIMS

This study describes a novel in vitro assay that simultaneously determines antifungal efficiency and host cell toxicity using suspensions of human leukaemic cells (HL-60) infected with Candida albicans.

METHODS AND RESULTS

The effect of Candida infection on host cell viability was evaluated by the microscopy of trypan blue-stained cells and lactate dehydrogenase (LDH) activity. The in vitro 'drug potency assay' utilized the Cell Counting Kit-8 and measured post-antifungal treatment viability of Candida-infected HL-60 cells and the ability of the antifungal treatment to prevent infection. LDH activity showed that 42% ± 4·0 and 85·3% ± 7·40 of HL-60 cells were killed following Candida infection at the multiplicity of infection (MOI) of 1 : 1 and 1 : 5, respectively. The antifungal nystatin (0·78-25 μmol l(-1) ) was found to inhibit C. albicans infection as seen by the significantly increased viability of HL-60 cells. Cytotoxicity of nystatin towards infected HL-60 cells was evident at higher concentrations and this was also confirmed by propidium iodide staining.

CONCLUSIONS

An assay using undisturbed cell suspension conditions was successfully developed for assessing the selectivity of the antifungal therapy in the host-Candida environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

The assay employing Candida infection of host cell suspensions represents a promising method for testing interactions of antifungal compounds with both fungal and host cells.

Molecular Pac-Man and Tacos: layered Cu(ii) cages from ligands with high binding site concentrations

Sheet Metal: The deliberate in situ Schiff base condensation of two organic subunits (hydroxamic acid and phenolic aldehyde) leads to polydentate ligands capable of forming large Cu(ii) cages of nuclearities ranging from [Cu₁₀] to [Cu₃₀].

Reading outcomes of children and adolescents with attention-deficit/hyperactivity disorder and dyslexia following atomoxetine treatment

Abstract Objective: This study assessed the efficacy of atomoxetine on attention-deficit/hyperactivity disorder (ADHD) symptoms in children and adolescents having ADHD with comorbid dyslexia (ADHD+D) and the effects of the treatment on reading measures.

METHODS

The analyses in this report used data from a study designed to examine the effects of a nonstimulant pharmacological agent, atomoxetine, on reading in children with ADHD+D. Patients ages 10-16 years with ADHD or ADHD+D received open-label atomoxetine for 16 weeks. The ADHD Rating Scale (ADHD-RS) and reading subtests of the Kaufman Test of Educational Achievement (K-TEA) were assessed. Changes in ADHD symptoms and reading scores were also analyzed by ADHD subtype. Treatment effect sizes and correlations between changes in ADHDRS and K-TEA scores were calculated.

RESULTS

After atomoxetine treatment, both ADHD and ADHD+D patient groups showed significant reduction in ADHD symptom and improvements in K-TEA reading scores. The range of treatment effect sizes on K-TEA scores was 0.35-0.53 for the ADHD group and 0.50-0.62 for the ADHD+D group. Pearson's correlation coefficients revealed only a few weak correlations between changes in ADHD symptoms and reading scores, regardless of diagnostic group.

CONCLUSIONS

ADHD symptoms and K-TEA reading scores improved for both the ADHD and ADHD+D groups following atomoxetine treatment. Correlation analyses indicate that improvements in reading outcomes cannot be explained by a reduction of ADHD symptoms alone. These findings support further exploration of the potential effects of atomoxetine on reading in children with ADHD and dyslexia or dyslexia alone.

Novel Nystatin A₁ derivatives exhibiting low host cell toxicity and antifungal activity in an in vitro model of oral candidosis

Opportunistic oral infections caused by Candida albicans are frequent problems in immunocompromised patients. Management of such infections is limited due to the low number of antifungal drugs available, their relatively high toxicity and the emergence of antifungal resistance. Given these issues, our investigations have focused on novel derivatives of the antifungal antibiotic Nystatin A1, generated by modifications at the amino group of this molecule. The aims of this study were to evaluate the antifungal effectiveness and host cell toxicity of these new compounds using an in vitro model of oral candidosis based on a reconstituted human oral epithelium (RHOE). Initial studies employing broth microdilution, revealed that against planktonic C. albicans, Nystatin A1 had lower minimal inhibitory concentration than novel derivatives. However, Nystatin A1 was also markedly more toxic against human keratinocyte cells. Interestingly, using live/dead staining to assess C. albicans and tissue cell viability after RHOE infection, Nystatin A1 derivatives were more active against Candida with lower toxicity to epithelial cells than the parent drug. Lactate dehydrogenase activity released by the RHOE indicated a fourfold reduction in tissue damage when certain Nystatin derivatives were used compared with Nystatin A1. Furthermore, compared with Nystatin A1, colonisation of the oral epithelium by C. albicans was notably reduced by the new polyenes. In the absence of antifungal agents, confocal laser scanning microscopy showed that C. albicans extensively invaded the RHOE. However, the presence of the novel derivatives greatly reduced or totally prevented this fungal invasion.

Comparative adherence of Candida albicans and Candida dubliniensis to human buccal epithelial cells and extracellular matrix proteins

Candida albicans and Candida dubliniensis are very closely related pathogenic yeast species. Despite their close relationship, C. albicans is a far more successful colonizer and pathogen of humans. The purpose of this study was to determine if the disparity in the virulence of the two species is attributed to differences in their ability to adhere to human buccal epithelial cells (BECs) and/or extracellular matrix proteins. When grown overnight at 30°C in yeast extract peptone dextrose, genotype 1 C. dubliniensis isolates were found to be significantly more adherent to human BECs than C. albicans or C. dubliniensis genotypes 2-4 (P < 0.001). However, when the yeast cells were grown at 37°C, no significant difference between the adhesion of C. dubliniensis genotype 1 and C. albicans to human BECs was observed, and C. dubliniensis genotype 1 and C. albicans adhered to BECs in significantly greater numbers than the other C. dubliniensis genotypes (P < 0.001). Using surface plasmon resonance analysis, C. dubliniensis isolates were found to adhere in significantly greater numbers than C. albicans to type I and IV collagen, fibronectin, laminin, vitronectin, and proline-rich peptides. These data suggest that C. albicans is not more adherent to epithelial cells or matrix proteins than C. dubliniensis and therefore other factors must contribute to the greater levels of virulence exhibited by C. albicans.

Interactions of Candida albicans with host epithelial surfaces

Candida albicans is an opportunistic, fungal pathogen of humans that frequently causes superficial infections of oral and vaginal mucosal surfaces of debilitated and susceptible individuals. The organism is however, commonly encountered as a commensal in healthy individuals where it is a component of the normal microflora. The key determinant in the type of relationship that Candida has with its host is how it interacts with the epithelial surface it colonises. A delicate balance clearly exists between the potentially damaging effects of Candida virulence factors and the nature of the immune response elicited by the host. Frequently, it is changes in host factors that lead to Candida seemingly changing from a commensal to pathogenic existence. However, given the often reported heterogeneity in morphological and biochemical factors that exist between Candida species and indeed strains of C. albicans, it may also be the fact that colonising strains differ in the way they exploit resources to allow persistence at mucosal surfaces and as a consequence this too may affect the way Candida interacts with epithelial cells. The aim of this review is to provide an overview of some of the possible interactions that may occur between C. albicans and host epithelial surfaces that may in turn dictate whether Candida removal, its commensal persistence or infection follows.

Antimicrobial resistance and virulence traits of Enterococcus faecalis from primary endodontic infections

OBJECTIVES

To determine the phenotypic and molecular characteristics of Enterococcus faecalis recovered from primary endodontic infections in Brazilian patients.

METHODS

Twenty isolates of E. faecalis recovered from 43 Brazilian patients with primary endodontic infections were identified by biochemical profiling (API20Strep) and 16S rDNA sequencing. Antimicrobial susceptibility was ascertained by agar dilution, using the recommended protocol of the Clinical and Laboratory Standards Institute (CLSI). PCR with validated primers was used to detect genes associated with antibiotic resistance and specific virulence factors.

RESULTS

All isolates were deemed susceptible to penicillin G, erythromycin and vancomycin. However, nine isolates had a minimum inhibitory concentration of 4μg/mL to vancomycin (the resistance breakpoint). Fourteen isolates (70% of isolates) were also resistant to tetracycline with MICs of >64μg/mL. PCR products for tetracycline resistance genes were detected in test isolates, while erythromycin and vancomycin resistance genes were not evident. Gelatinase, aggregation substance and enteroccocal surface protein genes were detected in 20, 18 and 12 isolates, respectively.

CONCLUSIONS

Endodontic E. faecalis isolates exhibit high level of resistance to tetracycline, an antibiotic that has use in local treatment of dental infections. This opens up a much-needed debate on the role and efficacy of this antibiotic for oral infections. Furthermore, these isolates were shown to possess genes that could contribute to pathogenicity in the pulp cavity.

Lipopolysaccharide-induced M2 to M1 macrophage transformation for IL-12p70 production is blocked by Candida albicans mediated up-regulation of EBI3 expression

Macrophages are heterogeneous cell populations that are present in all tissues. Macrophages can be divided into classically activated inflammatory macrophages (M1) and alternatively activated anti-inflammatory macrophages (M2). It has been generally accepted that M1 macrophages are polarised in an inflammatory environment to produce pro-inflammatory cytokines, whilst M2 macrophages are involved in anti-inflammation and aid tissue repair in wound healing. Bacterial endotoxin (lipopolysaccharide; LPS) is a potent factor in infection, which induces M1 macrophages resulting in higher levels of iNOS, TNFα and IL-12p70 which dictate inflammatory T cell responses. M2 macrophages can be transformed into M1 macrophages following LPS stimulation to promote inflammation. Candida albicans is a commensal fungal microorganism, which has been suggested to induce immune tolerance; however, the mechanism of C. albicans-induced immune tolerance has not been investigated in detail. IL-35 is a recently identified anti-inflammatory cytokine which is a heterodimeric protein consisting of the Epstein-Barr virus-induced gene 3 (EBI3) and IL-12p35. IL-35 shares the protein subunit p35, with IL-12p70. IL-12p70 is the most potent cytokine to induce Th1 responses during inflammation. In this study, we demonstrate that heat-killed C. albicans (HKC) strongly suppressed LPS-induced IL-12p70 production in M2 macrophages. Candida albicans induced a high level of EBI3 expression in M2 macrophages, which served as a mechanism for IL-12p70 suppression by competitive binding of the common protein subunit (p35) of IL-35 and IL-12p70. To demonstrate that EBI3 expression had the ability to block IL-12p70 production intracellularly, a Chinese Hamster Ovary (CHO) cell line with biscistronic expression of IL-12p40 and p35 was constructed, followed by ectopic over-expression of EBI3. The over-expression of EBI3 in the IL-12p70 producing cell line effectively suppressed IL-12p70 production. IL-35 secretion was also detected in the cell line, with suppressed IL-12p70 production by immune-precipitation Western blotting. However, this secretion was not evident in M2 macrophages following stimulation by HKC. This can be explained by the constitutive expression of IL-35 receptors (gp130 and IL-12Rβ2) in M2 macrophages for cytokine consumption. Our results have indicated that C. albicans can suppress host inflammatory responses in mucosal skin by suppressing LPS-induced IL-12p70 production. Lower IL-12p70 production may avoid an unnecessary Th1 response in order to retain immune tolerance, which may be one of the mechanisms by which C. albicans achieves a successful commensal lifestyle without having a detrimental effect on the host’s health.

Pannexin1 hemichannels are critical for HIV infection of human primary CD4+ T lymphocytes

HIV is a major public health issue, and infection of CD4(+) T lymphocytes is one of its key features. Whereas several cellular proteins have been identified that facilitate viral infection and replication, the role of hemichannels in these processes has not been fully characterized. We now show that the HIV isolates, R5 and X4, induced a transient-early (5-30 min) and a later, persistent (48-120 h) opening of Panx1 hemichannels, which was dependent on the binding of HIV to CD4 and CCR5/CXCR4 receptors. Blocking Panx1 hemichannels by reducing their opening or protein expression inhibited HIV replication in CD4(+) T lymphocytes. Thus, our findings demonstrate that Panx1 hemichannels play an essential role in HIV infection.

Oral care and pulmonary infection - the importance of plaque scoring

Improving the quality of oral hygiene is recognised as an important counter measure for reducing the incidence of ventilator-associated pneumonia amongst critically ill patients. Toothbrushing physically disrupts the dental plaque that acts as a reservoir for pulmonary infection and therefore has the potential to reduce the incidence of ventilator-associated pneumonia. Gu and colleagues performed a systematic review and meta-analysis of oral hygiene with and without a toothbrush and found no difference in the incidence of pneumonia in mechanically ventilated patients. The diagnosis of ventilator-associated pneumonia is prone to bias and future studies of oral care interventions should focus on measures of oral cleanliness such as plaque and gingival scores. Once the optimal strategy for oral hygiene is defined in the critically ill, larger studies focussing on ventilator-associated pneumonia or mortality can be conducted.

Developmental origins and architecture of Drosophila leg motoneurons

Motoneurons are key points of convergence within motor networks, acting as the "output channels" that directly control sets of muscles to maintain posture and generate movement. Here we use genetic mosaic techniques to reveal the origins and architecture of the leg motoneurons of Drosophila. We show that a small number of leg motoneurons are born in the embryo but most are generated during larval life. These postembryonic leg motoneurons are produced by five neuroblasts per hemineuromere, and each lineage generates stereotyped lineage-specific projection patterns. Two of these postembryonic neuroblasts generate solely motoneurons that are the bulk of the leg motoneurons. Within the largest lineage, lineage 15, we see distinct birth-order differences in projection patterns. A comparison of the central projections of leg motoneurons and the muscles they innervate reveals a stereotyped architecture and the existence of a myotopic map. Timeline analysis of axonal outgrowth reveals that leg motoneurons reach their sites of terminal arborization in the leg at the time when their dendrites are elaborating their subtype-specific shapes. Our findings provide a comprehensive description of the origin, development, and architecture of leg motoneurons that will aid future studies exploring the link between the assembly and organization of connectivity within the leg motor system of Drosophila.

Comparison of scarab grub populations and associated pathogens and parasitoids in warm- or cool-season grasses used on transitional zone golf courses

Seven different turfgrass species or mixes used on golf courses in the United States' transitional climatic zone were maintained as randomized and replicated plots in separate stands mowed at fairway (1.6 cm) or rough (6.4 cm) cutting heights and sampled in autumn to assess the density and species composition of scarab grubs; incidence of disease and parasitism thereof; and extent of turf damage from foraging insectivorous skunks, Mephitis mephitis. Influence of grass species on parasitism by spring or autumn-active tiphiid wasps was further assessed on implanted grubs in open enclosures. Masked chafers (Cyclocephala spp.) were three-fold more abundant than Japanese beetle, Popillia japonica Newman, grubs in plots of Zoysia and Cynodon sp. mowed at fairway height, and P. japonica were five-fold more abundant than masked chafer grubs in cool-season turf plots mowed at rough height. Phyllophaga spp. accounted for <1% of grubs in the samples. Milky disease bacteria (Paenibacillus sp.) were the predominant pathogens of Cyclocephala spp., followed by Serratia sp. bacteria and gregarines (Stictospora cf. villani). Cyclocephala grub densities, milky disease incidence (25%), and parasitism by the native tiphiid Tiphia pygidialis Alien (10-12%) were especially high in zoysiagrass. Japanese beetle grubs were infected by Paenibacillus, Serratia, Stictospora, and microsporidia (Ovavesicula sp.), but incidence of individual pathogens was relatively low (<6%) and similar among grasses within each stand. Few nematode-infected grubs were found. Skunk damage was mainly in the cool-season fairway-height grasses, probably reflecting difficulty in foraging in the much tougher stolons and rhizomes of the warm season turfgrasses. The degree of natural suppression of scarab grubs provided by endemic pathogens or parasitoids is unlikely to be compromised by the grass species used on a particular site.

Bispecific antibody-mediated detection of the Staphylococcus aureus thermonuclease

We report a novel fluorescence-based immunoassay which enables qualitative detection of the Staphylococcus aureus Thermonuclease (TNase) enzyme, thus providing confirmation of the presence of the S. aureus bacterium in vitro. The biomedical problem of chronic wound healing and the continuing emergence of antibiotic-resistant species is addressed in the development of a detection system capable of the rapid, real-time assessment of bacterial load and diversity. The use of bispecific antibodies (BsAb) provides integration of the molecular detection and signal response components of a standard immunoassay due to steric hindrance-mediated release of prebound fluorescent reporter molecules upon specific binding of TNase to adjacent sites. Rhodamine and fluorescein-labeled hemocyanin from Megathura crenulata (KLH) were prepared as effective immunoconjugates containing a sensitive fluorescent reporter moiety. BsAb that both specifically quenched the fluorescence of the reporter conjugate and bound the TNase target antigen were produced using cell fusion techniques. Assays were then performed to analyze the properties attributable to the steric hindrance-mediated release of the fluorescent reporter molecules upon adjacent TNase binding. This was performed by monitoring the intensity of fluorescence emission of the immunogenic reporter conjugate released into an aqueous environment at 578 and 520 nm, respectively.

Metabolism of deoxypyrimidines and deoxypyrimidine antiviral analogs in isolated brain mitochondria

The goal of this project was to characterize deoxypyrimidine salvage pathways used to maintain deoxynucleoside triphosphate pools in isolated brain mitochondria and to determine the extent that antiviral pyrimidine analogs utilize or affect these pathways. Mitochondria from rat brains were incubated in media with labeled and unlabeled deoxynucleosides and deoxynucleoside analogs. Products were analyzed by HPLC coupled to an inline UV monitor and liquid scintillation counter. Isolated mitochondria transported thymidine and deoxycytidine into the matrix, and readily phosphorylated both of these to mono-, di-, and tri-phosphate nucleotides. Rates of phosphorylation were much higher than rates observed in mitochondria from heart and liver. Deoxyuridine was phosphorylated much more slowly than thymidine and only to dUMP. 3'-azido-3'-deoxythymidine, zidovudine (AZT), an antiviral thymidine analog, was phosphorylated to AZT-MP as readily as thymidine was phosphorylated to TMP, but little if any AZT-DP or AZT-TP was observed. AZT at 5.5 ± 1.7 μM was shown to inhibit thymidine phosphorylation by 50%, but was not observed to inhibit deoxycytidine phosphorylation except at levels > 100 μM. Stavudine and lamivudine were inert when incubated with isolated brain mitochondria. The kinetics of phosphorylation of thymidine, dC, and AZT were significantly different in brain mitochondria compared to mitochondria from liver and heart.

Differential cellular and microbial responses to nano-/micron-scale titanium surface roughness induced by hydrogen peroxide treatment

This study investigated the effects of combined titanium nano-/micron-scale roughness, induced by hydrogen peroxide pre-treatments, on bone marrow stromal cell responses and Porphyromonas gingivalis adherence in vitro. Untreated surfaces exhibited nano-scale features, while hydrogen peroxide treatments promoted increased nano-/micron-scale roughness. Bone marrow stromal cell attachment and proliferation were maintained with 6 h and 24 h treatments, but significantly decreased on 1-week and 4-week-treated surfaces. Bone marrow stromal cells on 6 h-4 week-treated titanium demonstrated enhanced osteogenic differentiation versus untreated surfaces. P. gingivalis adherence was significantly increased on 24 h-4 week surfaces. Results suggest that 6 h but less than 24 h treatments maintain or promote bone marrow stromal cell responses while minimizing microbial adherence, potentially enhancing titanium surface bio-activation for osseointegration.