Marginal Ulcer Incidence and the Population of Gastrin Producing G cells Retained in the Gastric Pouch after Roux-en-Y Gastric Bypass: Is There a Relationship?

INTRODUCTION: Marginal ulcers are the most prevalent endoscopic abnormality after RYGB. The etiology is still poorly understood; however, an increase in acid secretion has been strongly implicated as a causal agent. Although gastrin is the greatest stimulant of acid secretion, to date, the presence of gastrin producing G cells retained in the gastric pouch, related to the occurrence of marginal ulcers, has not been evaluated. OBJECTIVE: Evaluate the density of G cells and parietal cells in the gastric pouch of RYGB patients with a diagnosis of marginal ulcer on the post-op EGD. METHOD: We retrospectively evaluated 1104 gastric bypasses performed between 2010 and 2020. Patients with marginal ulcer who met the inclusion criteria and controls were selected from this same population. Endoscopic gastric pouch biopsies were evaluated using immunohistochemical study and HE staining to assess G cell and parietal cell density. RESULTS: In total, 572 (51.8%) of the patients performed endoscopic follow-up after RYGB. The incidence of marginal ulcer was 23/572 (4%), and 3 patients required revision surgery due to a recalcitrant ulcer. The mean time for ulcer identification was 24.3 months (2-62). G cell count per high-power field (× 400) was statistically higher in the ulcer group (p < 0.05). There was no statistical difference in parietal cell density between groups (p 0.251). CONCLUSION: Patients with a marginal ulcer after gastric bypass present a higher density of gastrin-producing G cells retained in the gastric pouch.

Kinin B1 receptor deficiency protects mice fed by cafeteria diet from abnormal glucose homeostasis.

The kallikrein-kinin system has been implicated in body weight and glucose homeostasis. Their major effectors act by binding to the kinin B2 and B1 receptors. It was assessed the role of the kinin B1 receptor in weight and glucose homeostasis in B1 receptor knockout mice (B1RKO) subjected to a cafeteria diet (CAF). Wild-type (WT) and B1RKO male mice (C57BL/6 background; 8 weeks old) were fed a standard diet (SD) or CAF for 14 weeks, ad libitum, and four groups were formed: WT-SD; B1RKO-SD; WT-CAF; B1RKO-CAF. Body weight and food intake were assessed weekly. It was performed glucose tolerance (GTT) and insulin tolerance tests (ITT), and HOMA-IR, HOMA-ß and HOMA-ß* 1/HOMA-IR were calculated. Islets from WT and B1RKO were isolated in order to measure the insulin secretion. Western blot was used to assess the hepatic AKT phosphorylation and qPCR to assess gene expression. CAF induced a higher body mass gain in B1RKO compared to WT mice. CAF diet increased epididymal fat depot mass, hepatic fat infiltration and hepatic AKT phosphorylation in both genotypes. However, B1RKO mice presented lower glycemic response during GTT when fed with CAF, and a lower glucose decrease in the ITT. This higher resistance was overcomed with higher insulin secretion when stimulated by high glucose, resulting in higher glucose uptake in the GTT when submitted to CAF, despite lower insulin sensitivity. Islets from B1RKO delivered 4 times more insulin in 3-month-old mice than islets from WT. The higher insulin disposition index and high insulin delivery of B1RKO can explain the decreased glucose excursion during GTT. In conclusion, CAF increased the ß-cell function in B1RKO mice, compensated by the diet-induced insulin resistance and resulting in a healthier glycemic response despite the higher weight gain.

Comparison of the operative time and presence of voids of incremental and bulk-filling techniques on Class II composite restorations.

OBJECTIVES: To compare the operative time and presence of air voids on Class II restorations fabricated by dental practitioners with 1 to 5 years of experience using incremental and bulk-filling techniques. METHOD AND MATERIALS: Four techniques were evaluated: incremental, bulk-filling, bulk-filling with heated composite, and snowplow technique. Standardized mandibular first molars with a MOD (mesial, occlusal, and distal) cavity were used. Voluntary operators made two restorations using each technique and the time required for each restoration was recorded. The restorations were scanned by micro-computed tomography to calculate the volume of the restoration occupied by air voids. The "operative time" and "volume of air voids" were analyzed individually by two-way ANOVA and Tukey HSD post hoc (α = .05) for the factors operator and insertion technique. A correlation between "operative time" and "volume of air voids" was evaluated using Pearson coefficient (α = .05). RESULTS: The incremental technique required significantly longer time, yet no differences were observed between the bulk-filling techniques. There were no significant differences between techniques regarding the volume of air voids. A significant, but weak, and inverse linear correlation (P = .0059; r = -.29; r2 = 8.41%) was found between the operative time and volume of air voids. CONCLUSION: There were no significant differences in the volume of air voids among the evaluated techniques, although bulk-filling techniques required a shorter operative time. Hence, implementing bulk-filling techniques by dental schools and restorative dental practitioners with different levels of expertise may reduce chair time and produce a volume of air voids similar to the incremental technique.

Identification of trailer heat zones and associated heat stress in weaner pigs transported by road in tropical climates.

Heat stress is major welfare concern during transport of pigs in tropical climates, which can also lead to direct production costs. This study evaluated the dynamics of heat zones through the load and their relationship with heat stress of weaner pigs during road transport in a tropical climate. Both environmental (e.g. temperature and relative humidity) and physiological (e.g. respiratory frequency and lactate) measures were recorded from four vehicle journeys (70 km distance, 216 weaner pigs within each trailer load) within Ceará, northeastern Brazil. Geostatistics and fluid dynamics simulation techniques were applied to understand the dynamics of heat zones and ventilation patterns the truckload. Statistics based on canonical discriminant analysis and ANOVA were performed to verify the relationship between heat zones and heat stress in pigs. The results showed that, during transport, the generation of heat zones occurred with different magnitudes along the load (P < 0.05), which was harmonized by the ventilation dynamics. There was a heat core with high energy content, in the front region of the lower deck (LD) of the trailer. In this zone, weaners pigs had higher rectal temperature (+1.8 °C temperature difference), respiratory frequency (LD = 94 ± 1.3 breaths/min; UD = 86 ± 1.3 breaths/min), and blood cortisol concentration (LD = 32.9 ± 0.8 ng/mL; UD = 30.18 ± 0.6 ng/mL) (all P < 0.05). Weaners pigs transported in the upper deck (UD) compartments had the highest skin temperature (LD = 38.13 ± 0.3 °C; UD = 38.9 ± 0.22 °C) and the highest mean values of blood lactate (LD = 65.5 ± 1.11 m/M; UD = 71.60 ± 1.19 m/M) and Creatine kinase (LD = 3891.23 ± 69U/L; UD = 4107.43 ± 62U/L) (P < 0.05). Weaners transported in compartments of the LD of trailer were more susceptible to heat stress, while weaners in the UD compartments were more susceptible to physical stress and muscle exhaustion. These results provide additional evidence of heat zones within trailer compartments and highlight the requirement for the planning of pig transport operations in tropical climates to mitigate risks of heat stress.

Influence of beam homogenization on bond strength of adhesives to dentin.

OBJECTIVE: This study evaluated the effect of beam homogeneity on the microtensile bond strength (µTBS) of two adhesive resins to dentin. METHODS: One polywave light-emitting-diode (LED) LCU (Bluephase Style, Ivoclar Vivadent AG) was used with two different light guides: a regular tip (RT, 1010 mW/cm2 emittance) and a homogenizer tip (HT, 946 mW/cm2 emittance). The emission spectra and beam profiles were measured from both light guides. Extracted third molars were prepared for µTBS evaluation using two adhesive systems: Excite F (EXF) and Adhese Universal (ADU). Bond strength was calculated for each specimen (n = 10) at locations that correlated with the output of the two LED chips emitting blue (455 nm) and the one chip that emitted violet light (409 nm) after 24-hs and after one-year water-storage. The µTBS was analyzed using a four-way analysis of variance (factors: adhesive system, light guide, LED wavelength, and storage time) and post-hoc Tukey test (α = 0.05). RESULTS: EXF always delivered a higher µTBS than ADU (p < 0.0001), with the µTBS of ADU being about 20% lower than EXF. The light guide (p = 0.0259) and storage time (p = 0.0009) significantly influenced the µTBS. The LED wavelengths had no influence on the µTBS (p > 0.05). SIGNIFICANCE: Homogeneity of the emitted light beam was associated with higher 24-h µTBS to dentin, regardless of the adhesive tested. Also, differences in the composition of adhesives can affect their compatibility with restorative composites and their ability to maintain bonding over one year.

Human urine metabolomic signature after ingestion of polyphenol-rich juice of purple grumixama (Eugenia brasiliensis Lam.).

Polyphenol intake has been associated with health promotion because of its interaction with several metabolic pathways. This study investigates changes in the urine metabolome following acute intake of polyphenol-rich juice, purple grumixama juice. Grumixama (Eugenia brasiliensis Lam.) is a cherry native to Brazil that is known to be a rich source of anthocyanins and ellagitannins. In this research 15 healthy subjects consumed a single dose of grumixama juice. Urine samples were collected before grumixama juice intake, 0-1, 1-2, 2-4 h, with fasting at 24 h after intake. Plasma samples were also collected before intake, 30' and at 1 h, 2 h and 4 h, with fasting at 24 h after juice intake. The urine primary metabolites were analysed by a metabolomic approach using gas chromatography mass spectrometry with methyl chloroformate derivatisation for amino acids and organic acids. Also, an oxygen radical absorbance capacity method was carried out to evaluate the plasma samples antioxidant capacity changes. Subjects showed increase in plasma antioxidant capacity after juice intake (p-values < .05). A total of 114 metabolites were assessed in urine (1-2 h and 2-4 h), including 17 amino acids, 47 organic acids and several other metabolites. Among the 114 metabolites, 25 were significantly changed during the first 4 h following juice intake, as shown by the Orthogonal Partial Least Squares Discriminant Analysis (0.5 > p(corr) > 0.3) and univariate analysis (p-values < .05). Some metabolites were related to mitochondrial metabolism, such as glyoxylic acid and oxalic acid. Metabolites related to amino acid metabolism were also changed, such as beta-alanine, l-phenylalanine and l-tyrosine. In conclusion, results suggest that acute intake of grumixama juice could affect amino acid metabolism and mitochondrial metabolism, but the related health implications should be explored in further studies using additional approaches.

Natural Ecosystem Surrounding a Conventional Banana Crop Improves Plant Health and Fruit Quality.

Natural ecosystems near agricultural landscapes may provide rich environments for growing crops. However, the effect of a natural ecosystem on crop health and fruit quality is poorly understood. In the present study, it was investigated whether the presence of a natural ecosystem surrounding a crop area influences banana plant health and fruit postharvest behavior. Plants from two conventional banana crop areas with identical planting time and cultural practices were used; the only difference between banana crop areas is that one area was surrounded by a natural forest (Atlantic forest) fragment (Near-NF), while the other area was inserted at the center of a conventional banana crop (Distant-NF). Results showed that bananas harvested from Near-NF showed higher greenlife and a more homogeneous profile during ripening compared to fruits harvested from Distant-NF. Differences in quality parameters including greenlife, carbohydrate profile, and pulp firmness between fruits harvested from Near-NF and Distant-NF are explained, at least partly, by differences in the balance of plant growth regulators (indole-3-acetic acid and abscisic acid) in bananas during ripening. Furthermore, plants from Near-NF showed a lower severity index of black leaf streak disease (BLSD) and higher levels of phenolic compounds in leaves compared to plants from Distant-NF. Together, the results provide additional evidence on how the maintenance of natural ecosystems near conventional crop areas could be a promising tool to improve plant health and fruit quality.

Quantifying intraclass correlations for count and time-to-event data.

The intraclass correlation is commonly used with clustered data. It is often estimated based on fitting a model to hierarchical data and it leads, in turn, to several concepts such as reliability, heritability, inter-rater agreement, etc. For data where linear models can be used, such measures can be defined as ratios of variance components. Matters are more difficult for non-Gaussian outcomes. The focus here is on count and time-to-event outcomes where so-called combined models are used, extending generalized linear mixed models, to describe the data. These models combine normal and gamma random effects to allow for both correlation due to data hierarchies as well as for overdispersion. Furthermore, because the models admit closed-form expressions for the means, variances, higher moments, and even the joint marginal distribution, it is demonstrated that closed forms of intraclass correlations exist. The proposed methodology is illustrated using data from agricultural and livestock studies.

Nitrogen requirements of white-lipped peccary (Mammalia, Tayassuidae).

A study was conducted to determine the protein requirement of the white-lipped peccary (Tayassu pecari) performing a nitrogen (N) balance digestion trial. In a 4 × 4 Latin square design, four adult captive male peccaries were fed four isoenergetic diets containing four different levels of N (13.3, 19.2, 28.7, and 37.1 g N/kg dry matter). After 15 days of adaptation, the total collection of feces and urine was carried out for five consecutive days. By regression analysis between N intake and N in feces and urine, the metabolic fecal nitrogen (MFN = 3.1 g/kg of dry matter intake) and daily endogenous urinary N (EUN = 91.0 mg/kg(0.75) ) were determined. Likewise, by regression analyses between consumption of nitrogen and the nitrogen balance [NBN consumed-(fecal N + Urine N)] we estimated the daily requirement of 336.5 mgN/kg(0.75) . Therefore, if food intake is unrestricted, white-lipped peccaries require a minimum content in their diet of about 4.5% crude protein as percentage of dry diet. These values are similar to those found in frugivorous wild ruminants, which reinforces the proposition that peccaries have a digestive physiology nearer to that of ruminants than of domestic pigs. Furthermore, the low nutritional maintenance requirements for white-lipped peccary may explain how this species thrive in the Neo-tropical region eating predominantly palm-fruits that normally have low crude protein contents.

Spatial distribution of cancer stem cells in head and neck squamous cell carcinomas.

BACKGROUND: CD44 and aldehyde dehydrogenase 1 (ALDH1) are considered putative markers of highly tumorigenic cells (i.e., cancer stem-like cells) in head and neck squamous cell carcinomas. This small subset of cells is believed to be the primary responsible for tumor initiation and progression. The objectives of this study were (i) to evaluate the patterns of CD44 and ALDH1 expression in the tumor center and in the invasive front, as well as in adjacent non-tumor epithelium, and (ii) to correlate these findings with clinical parameters. MATERIALS AND METHODS: The sample comprised 44 patients with primary head and neck squamous cell carcinomas. Hematoxylin and eosin (HE) staining was used for histopathological tumor grading and for morphological analysis of adjacent non-tumor epithelium. Semiquantitative analysis was performed in histological sections immunostained for CD44 and ALDH1. RESULTS: ALDH1 immunostaining in the invasive front showed positive association with tumor size, regional metastasis, tumor histopathological grading, and disease progression. Moreover, expression of this marker in both tumor invasive front and adjacent non-tumor epithelium was related with more aggressive tumors. CD44 immunostaining was heterogeneous in all areas evaluated and did not show association with clinical data. CONCLUSION: Collectively, these data suggest that ALDH1 immunostaining in the invasive front and in adjacent non-tumor epithelium may help identify tumors with a more aggressive behavior, potentially contributing to improving treatment customization and the monitoring of patients with head and neck cancer.

Phenotypic stability of hybrids of Gália melon in Rio Grande do Norte state, Brazil

The objectives of this study were to determine the importance of simple and complex components of the interaction genotype × environment and to evaluate the adaptability and stability of Gália melon hybrids. Nine hybrids were tested in twelve environments of Rio Grande Norte State from 2000 to 2001. The experiments were carried out in a randomized complete block design with three replications. The statistical methods of Toler and Burrows, Wricke and AMMI (Additive Main effect and Multiplicative Interaction) were used to study the adaptability and stability. The complex component is responsible for most of the genotype × environment interaction for the yield and content of solids soluble of fruits. The environments associated with Mossoró and Assu municipalities are the most suitable to evaluate melon hybrids in the state. The hybrid DRG 1537 was the most likely to be grown in the Agro-industrial Complex Mossoró-Assu due to its stability, high productivity and high content of soluble solids.

Os objetivos deste estudo foram determinar a importância das componentes simples e complexa da interação genótipo × ambiente e avaliar a adaptabilidade e estabilidade de híbridos de melão Gália. Nove híbridos foram testados em doze ambientes do Estado do Rio Grande Norte no período de 2000 a2001. Os experimentos foram conduzidos em blocos completos casualizados com três repetições. Os métodos estatísticos de Toler e Burrows, Wricke e AMMI (Additive Main effect and Multiplicative Interaction) foram usados para estudar a adaptabilidade e estabilidade. A componente complexa é responsável pela maior parte da interação genótipo × ambiente para a produtividade e teor de sólidos solúveis dos frutos. Os ambientes associados com Mossoró e Assu são os mais adequados para a avaliação de melão híbrido. O híbrido DRG1537 é o mais promissor para o cultivo no Complexo Agro-industrial Mossoró-Assu, devido à sua estabilidade, alta produtividade e alto teor de sólidos solúveis.

Phenotypic stability of hybrids of Gália melon in Rio Grande do Norte state, Brazil.

The objectives of this study were to determine the importance of simple and complex components of the interaction genotype × environment and to evaluate the adaptability and stability of Gália melon hybrids. Nine hybrids were tested in twelve environments of Rio Grande Norte State from 2000 to 2001. The experiments were carried out in a randomized complete block design with three replications. The statistical methods of Toler and Burrows, Wricke and AMMI (Additive Main effect and Multiplicative Interaction) were used to study the adaptability and stability. The complex component is responsible for most of the genotype × environment interaction for the yield and content of solids soluble of fruits. The environments associated with Mossoró and Assu municipalities are the most suitable to evaluate melon hybrids in the state. The hybrid DRG 1537 was the most likely to be grown in the Agro-industrial Complex Mossoró-Assu due to its stability, high productivity and high content of soluble solids.

Effect of endodontic sealer and resin luting strategies on pull-out bond strength of glass fiber posts to dentin

The aim of this study was to evaluate the influence of eugenolcontaining endodontic sealers and luting strategy on the pull-out bond strength of glass fiber posts to dentin. Sixty-four bovine incisors were randomly assigned into two groups of 32 specimens each for obturation procedure with gutta-percha only, or with Pulp Canal Sealer EWT. Subsequently, the roots were prepared for the fiber post Reforpost and all specimens of each endodontic sealing procedure were allocated to four groups (n=8), according to the strategies for post cementation: A) Single Bond 2 and RelyX ARC; B) All Bond 2 and C&B cement; C) All Bond 2 and RelyX ARC; D) Single Bond 2 and C&B Cement. The posts were cemented immediately after the endodontic treatment. The pull-out test was performed at a cross-head speed of 0.5 mm/min in a universal testing machine (EMIC). Data (Kgf) were submitted to a two-way ANOVA and Tukey test (p ≤ 0.05). The eugenol-based sealer did not influence the pull-out bond strength of fiber posts regardless of the luting strategy. RelyX ARC showed higher bond strength than C&B Cement when used with Single Bond 2 adhesive system, when the eugenol-based sealer was present. All Bond 2, when associated to all cements studied, promoted similar bond strength, regardless of the eugenol-containing endodontic sealer. In conclusion, eugenolcontaining sealer did not influence the pull-out bond strength values of the resin luting systems for glass fiber post cementation. The bond system and resin cement association from the same manufacturer had similar bond strength values for dentin.

O objetivo desse estudo foi avaliar a influencia de cimentos endodonticos a base de eugenol e estrategia de cimentacao resinosa na resistencia a tracao de pinos de fibra de vidro a dentina. Sessenta e quatro incisivos bovinos foram aleatoriamente divididos em dois grupos com 32 especimes para cada procedimento de obturacao, com o cimento a base de eugenol Pulp Canal Sealer EWT ou somente com guta percha pela tecnica termoplastificada. Apos, realizou-se o prepare do conduto radicular para o pino de fibra Reforpost e posteriormente, as amostras de cada procedimento obturador foram separadas em quarto grupos (n=8), considerando as estrategias para cimentacao do pino: A) Adper Single Bond 2 e RelyX ARC; B) All Bond 2 e C&B cement; C) All Bond 2 e RelyX ARC; D) Adper Single Bond 2 e C&B Cement. Os pinos foram imediatamente cimentados apos o tratamento endodontico. Dessa maneira, o teste de pull-out foi realizado a uma velocidade de 0.5 mm/min em maquina de ensaio universal (EMIC DL2000). Os dados (Kgf) A analise estatistica foi realizada pelos testes ANOVA de dois fatores e teste de Tukey (p ≤ 0.05). O cimento endodontico contend eugenol nao influenciou a resistencia de uniao a tracao (pull-out) dos pinos de fibra, independente da estrategia de cimentacao. O RelyX ARC ofereceu maior resistencia de uniao do pino a dentina, comparado ao C&B Cement quanto utilizado com o Adper Single Bond 2, na presenca do cimento endodontico contendo eugenol. O All Bond 2 quando associado a todos os cimentos estudados promoveram uma resistencia de uniao semelhante, independente do conteudo de eugenol na cimentacao endodontica. Em conclusao, o cimento endodontico a base de eugenol nao influenciou na resistencia a tracao de pinos de fibra a dentina. A associacao de sistema adesivo e cimento resinoso do mesmo fabricante apresentou valores de resistencia de uniao semelhantes na cimentacao de pinos de fibra.

Effect of endodontic sealer and resin luting strategies on pull-out bond strength of glass fiber posts to dentin.

The aim of this study was to evaluate the influence of eugenol-containing endodontic sealers and luting strategy on the pull-out bond strength of glass fiber posts to dentin. Sixty-four bovine incisors were randomly assigned into two groups of 32 specimens each for obturation procedure with gutta-percha only, or with Pulp Canal Sealer EWT Subsequently, the roots were prepared for the fiber post Reforpost and all specimens of each endodontic sealing procedure were allocated to four groups (n = 8), according to the strategies for post cementation: A) Single Bond 2 and RelyX ARC; B) All Bond 2 and C&B cement; C) All Bond 2 and RelyX ARC; D) Single Bond 2 and C&B Cement. The posts were cemented immediately after the endodontic treatment. The pull-out test was performed at a cross-head speed of 0.5 mm/min in a universal testing machine (EMIC). Data (Kgf) were submitted to a two-way ANOVA and Tukey test (p < or = 0.05). The eugenol-based sealer did not influence the pull-out bond strength of fiber posts regardless of the luting strategy. RelyX ARC showed higher bond strength than C&B Cement when used with Single Bond 2 adhesive system, when the eugenol-based sealer was present. All Bond 2, when associated to all cements studied, promoted similar bond strength, regardless of the eugenol-containing endodontic sealer In conclusion, eugenol-containing sealer did not influence the pull-out bond strength values of the resin luting systems for glass fiber post cementation. The bond system and resin cement association from the same manufacturer had similar bond strength values for dentin.

Parainfluenza virus 5 genomes are located in viral cytoplasmic bodies whilst the virus dismantles the interferon-induced antiviral state of cells.

Although the replication cycle of parainfluenza virus type 5 (PIV5) is initially severely impaired in cells in an interferon (IFN)-induced antiviral state, the virus still targets STAT1 for degradation. As a consequence, the cells can no longer respond to IFN and after 24-48 h, they go out of the antiviral state and normal virus replication is established. Following infection of cells in an IFN-induced antiviral state, viral nucleocapsid proteins are initially localized within small cytoplasmic bodies, and appearance of these cytoplasmic bodies correlates with the loss of STAT1 from infected cells. In situ hybridization, using probes specific for the NP and L genes, demonstrated the presence of virus genomes within these cytoplasmic bodies. These viral cytoplasmic bodies do not co-localize with cellular markers for stress granules, cytoplasmic P-bodies or autophagosomes. Furthermore, they are not large insoluble aggregates of viral proteins and/or nucleocapsids, as they can simply and easily be dispersed by 'cold-shocking' live cells, a process that disrupts the cytoskeleton. Given that during in vivo infections, PIV5 will inevitably infect cells in an IFN-induced antiviral state, we suggest that these cytoplasmic bodies are areas in which PIV5 genomes reside whilst the virus dismantles the antiviral state of the cells. Consequently, viral cytoplasmic bodies may play an important part in the strategy that PIV5 uses to circumvent the IFN system.

Catalytic turnover of STAT1 allows PIV5 to dismantle the interferon-induced anti-viral state of cells.

A dynamic model of STAT1 degradation by the V protein of parainfluenza virus 5 (PIV5; formerly SV5) has been proposed. In it, the V protein functions as a bipartite adaptor linking DDB1, a component of a cellular SCF-like ubiquitin E3 ligase complex, to STAT2, which in turn binds STAT1 and presents STAT1 to the E3 ligase complex for ubiquitination and subsequent degradation. Furthermore, it appears that loss of STAT1 from the complex results in decreased affinity of V for STAT2 such that STAT2 either dissociates from V or is displaced by STAT1/STAT2 complexes, facilitating the cycling of the DDB1/PIV5 V containing E3 complex for further rounds of STAT1 ubiquitination and degradation. By determining the approximate number of molecules of V, DDB1, STAT1 and STAT2 present in IFN-treated 2fTGH cells, we provide additional evidence for this dynamic model of STAT1 degradation. These results show that (i) in IFN-treated cells there is approximately 4-fold less STAT2 and 15-fold less DDB1 than STAT1 per cell and thus DDB1 and STAT2 must repeatedly acquire more STAT1 for degradation to go to completion, and (ii) approximately 600 molecules of V protein per cell can target as many as 120,000 molecules of STAT1 for degradation in the absence of either viral or cellular protein synthesis. The importance of this mechanism in terms of the ability of the virus to dismantle the IFN-induced anti-viral state of cells is discussed.

AGS and other tissue culture cells can unknowingly be persistently infected with PIV5; a virus that blocks interferon signalling by degrading STAT1.

Whilst screening various cell lines for their ability to respond to interferon (IFN), we noted that in comparison to other tissue culture cells AGS tumour cells, which are widely used in biomedical research, had very low levels of STAT1. Subsequent analysis showed that the reason for this is that AGS cells are persistently infected with parainfluenza virus type 5 (PIV5; formally known as SV5), a virus that blocks the interferon (IFN) response by targeting STAT1 for proteasome-mediated degradation. Virus protein expression in AGS is altered in comparison to the normal pattern of virus protein synthesis observed in acutely infected cells, suggesting that the AGS virus is defective. We discuss the relevance of these results in terms of the need to screen cell lines for persistent virus infections that can alter cellular functions.

Interferon-induced inhibition of parainfluenza virus type 5; the roles of MxA, PKR and oligo A synthetase/RNase L.

We have previously reported that the addition of interferon (IFN) to the culture medium of Vero cells (which cannot produce IFN) that were infected with the CPI- strain of parainfluenza virus 5 (PIV5, formally known as SV5), that fails to block IFN signaling, rapidly induces alterations in the relative levels of virus mRNA and protein synthesis. In addition, IFN treatment also caused a rapid redistribution of virus proteins and enhanced the formation of cytoplasmic viral inclusion bodies. The most studied IFN-induced genes with known anti-viral activity are MxA, PKR and the Oligo A synthetase/RNase L system. We therefore examined the effects of these proteins on the replication cycle of PIV5. These studies revealed that while these proteins had some anti-viral activity against PIV5 they were not primarily responsible for the very rapid alteration in virus protein synthesis observed following IFN treatment, nor for the IFN-induced formation of virus inclusion bodies, in CPI- infected cells.

Effect of the composite photoactivation mode on microtensile bond strength and Knoop microhardness.

OBJECTIVE: This study evaluated the effect of the composite photoactivation mode on microtensile bond strength and Knoop microhardness. METHODS: Standard class I cavities (3 x 4 x 3mm) were restored with two adhesives systems, Single Bond (SB) and Clearfil SE Bond (CE), and the TPH composite. The photoactivation of the composite was carried out using three modes: Conventional (CO: 400 mW/cm(2) x 40s), Soft-Start (SS: 100 mW/cm(2) x 10s+600 mW/cm(2) x 30s) and Pulse-Delay (PD: 100 mW/cm(2) x 3s+3 min wait+600 mW/cm(2) x 37s). For the microtensile test, beams obtained from the buccal wall bond interface were tested under tension at 0.5mm/min crosshead speed until failure. For the microhardness test, the restorations were sectioned in the mesio-distal direction and indentations were made on the internal composite surface of each half at three different depths. Data of two tests were analyzed using two-way ANOVA and LSMeans (alpha=0.05). RESULTS: In the microtensile test, SS presented the highest values. PD presented intermediate values without differing significantly from the other modes. For adhesives, SB presented the highest values. In the microhardness test, PD presented the highest values, differing significantly from SS. CO presented intermediate values but without any statistical difference from the others. The SS-CE interaction presented the lowest values with statistical differences from all the others. SIGNIFICANCE: By the SS technique, the highest bond strength was obtained. However, this technique made it possible for the adhesive system to intervene with the hardness of the composite.

Interferon-induced alterations in the pattern of parainfluenza virus 5 transcription and protein synthesis and the induction of virus inclusion bodies.

Although parainfluenza virus 5 (simian virus 5 [SV5]) circumvents the interferon (IFN) response by blocking IFN signaling and by reducing the amount of IFN released by infected cells, its ability to circumvent the IFN response is not absolute. The effects of IFN on SV5 infection were examined in Vero cells, which do not produce but can respond to IFN, using a strain of SV5 (CPI-) which does not block IFN signaling. Thus, by infecting Vero cells with CPI- and subsequently treating the cells with exogenous IFN, it was possible to observe the effects that IFN had on SV5 infection in the absence of virus countermeasures. IFN rapidly (within 6 h) induced alterations in the relative levels of virus mRNA and protein synthesis and caused a redistribution of virus proteins within infected cells that led to the enhanced formation of virus cytoplasmic inclusion bodies. IFN induced a steeper gradient of mRNA transcription from the 3' to the 5' end of the genome and the production of virus mRNAs with longer poly(A) tails, suggesting that the processivity of the virus polymerase was altered in cells in an IFN-induced antiviral state. Additional evidence is presented which suggests that these findings also apply to the replication of strains of SV5, parainfluenza virus type 2, and mumps virus that block IFN signaling when they infect cells that are already in an IFN-induced antiviral state.