Effect of Calcium Hydroxide and Antioxidant Agents Filling the Pulp Chamber after Internal Bleaching

To evaluate the effect of calcium hydroxide (CH), sodium ascorbate (SA) and sodium thiosulfate (ST) filling the pulp chamber on color stability and longevity of teeth after internal bleaching. Crowns of bovine incisors were submitted to internal bleaching and divided into groups according the material used in the pulp chamber: Control, CH, SA, ST. Each group was divided into two subgroups according to the time to perform restorative procedures (7 or 15 days). Color measurement was performed with a spectrophotometer at nine periods. The darkening (ΔE) values were calculated. The Mann-Whitney test was used to statistically analyze the data (p ⟨ 0.05). After bleaching, ΔE values were higher than 3.5, showing that the procedure was effective. After 24 hours, no difference was observed between groups. After 7 days, SA showed higher ΔE than the control group (p ⟨ 0.05). CH and TS did not differ from the control group. In restorations performed after 7/15 days, SA group showed higher values of darkening after 1 and 4 months than the control group (p ⟨ 0.05). SA induced perceptible darkening after bleaching and should not be used to fill the pulp chamber. ST and CH show color stability and longevity after 12 months.

The Effect of Colloidal Silica and Glaze Coatings on the Adhesion of Zirconia with Various Ytrria Concentration

PURPOSE

This study evaluated the effect of coating traditional and translucent Y-TZP with an industrial nanometric colloidal silica or glaze before or after sintering on the adhesion of zirconia with various ytrria concentration.

MATERIALS AND METHODS

Specimens of Y-TZP with 3% and 5% yttria were subdivided into 5 groups (n=10), according to the coating applied and moment of application (before or after Y-TZP sintering): Control (no coating), Colloidal Silica/Sintering, Sintering/Colloidal Silica, Glaze/Sintering, Sintering/ Glaze. Lithium disilicate (LD) was used as positive control. Except for Y-TZP controls, groups were conditioned with silane before cementation with a self-adhesive resin cement. After 24 hours, the shear bond strength and failure analysis were performed. Also, analysis of specimens' surface was accomplished with SEM-EDX. Kruskal-Wallis and Dunn tests were applied to analyze differences between groups (p⟨0.05).

RESULTS

Overall, the worst and best values of shear bond strength test were control and glaze after sintering groups. Different morphological and chemical aspects were observed in SEM-EDX analysis.

CONCLUSIONS

Coating Y-TZP with colloidal silica showed unsatisfactory results. In 3Y-TZP, the surface treatment associated with the best adhesion values was the application of glaze after zirconia sintering. However, in 5Y-TZP, glaze application can be performed before or after the zirconia sintering to optimize clinical steps.

A deep learning platform to assess drug proarrhythmia risk

Drug safety initiatives have endorsed human iPSC-derived cardiomyocytes (hiPSC-CMs) as an in vitro model for predicting drug-induced cardiac arrhythmia. However, the extent to which human-defined features of in vitro arrhythmia predict actual clinical risk has been much debated. Here, we trained a convolutional neural network classifier (CNN) to learn features of in vitro action potential recordings of hiPSC-CMs that are associated with lethal Torsade de Pointes arrhythmia. The CNN classifier accurately predicted the risk of drug-induced arrhythmia in people. The risk profile of the test drugs was similar across hiPSC-CMs derived from different healthy donors. In contrast, pathogenic mutations that cause arrhythmogenic cardiomyopathies in patients significantly increased the proarrhythmic propensity to certain intermediate and high-risk drugs in the hiPSC-CMs. Thus, deep learning can identify in vitro arrhythmic features that correlate with clinical arrhythmia and discern the influence of patient genetics on the risk of drug-induced arrhythmia.

Modeling gait score of broiler chicken via production and behavioral data

Lameness in broilers may be associated with pain and is considered a major broiler production and welfare concern. Manual gait score assessment in commercial broiler houses is discrete, time-consuming, and laborious. As such, automatic methods for broiler gait score assessment are urgently needed. The objective of this study was to identify the relation of broiler gait score with several productions and behavioral metrics (bird BW, age, activity, and distribution), and establish three gait score prediction models for automatic gait score estimations in broiler farms with automatic weighing systems, camera systems, or both. Sixteen pens were used to rear Cobb 500 and Ross 708 broilers for eight and nine weeks, respectively (eight pens/strain, 12 birds/pen). The gait scores of all birds were assessed weekly by trained assessors following a six-point (0-5) scoring protocol from the third week. The pen's average BW was measured weekly. Top-view cameras were installed to continuously record videos of broilers in all 16 pens. Images were extracted from video clips (10 min/hour) during a 16-hour light period to determine the activity index and distribution index through image processing. The gait score was positively correlated with BW (R² = 0.97 for Cobb and R² = 0.96 for Ross), while negatively correlated with activity (R² = 0.78 for Cobb and R² = 0.73 for Ross). The three models showed high accuracies in predicting broiler gait score based on variables of BW, age, activity index, and distribution index (R² = 0.90-0.91, RMSE = 0.38-0.41). The findings of this study demonstrated the potential of estimating broiler gait score using bird BW, age, activity index, and distribution index. This information will assist in the development of automated gait score assessment systems in broiler production.

Abstract P2109: Elaborating Safety Margins To Predict Drug Proarrhythmia Using Deep Learning And Patient-derived IPSCs

Introduction: Drug-induced arrhythmias are a common cause for drug attrition during development and for restricted use or withdrawal from the market. Cell based assays to assess arrhythmia risk typically rely on the quantification of waveform features - e.g. action potential prolongation and after depolarizations - in the cells’ action potential. However, the predictive power of these approaches is limited.

Hypothesis: We hypothesize that deep learning can extract features relevant to discriminating input classes in a systematic and unbiased manner, effectively removing the need for human-defined metrics. This can lead to a new model to estimate torsadogenic risk of drugs and evaluate the influence of myopathic gene variants on drug-induced arrhythmia.

Methods: We optically recorded action potentials optically recorded for 40 drugs - characterized high, intermediate, and low or no torsadogenic risk in patients- at 8 concentrations in hiPSC-CMs from 3 healthy donors and 5 hiPSC-CMs isogenic lines carrying 5 gene variants that cause dilated and hypertrophic cardiomyopathies. We designed a convolutional neural network (CNN) to classify non-arrhythmic, arrhythmic and asystolic traces in hiPSC-CMs. Using the class probabilities measured by the CNN, we created torsadogenic and asystolic safety margins for each drug and cell line.

Results: The arrhythmic class probability computed by the CNN, provided a continuous, dose-dependent metric of the proarrhythmic risk of drugs in healthy and cardiomyopathic hiPSC-CMs. We used this metric to estimate safety margins for drug-induced arrhythmia and achieved a 0.942 AUC in classifying drugs of high-intermediate risk from safe ones. We used this approach to discern the contribution of putative genetic risk factors to arrhythmia susceptibility by comparing the risk profiles of the same drugs in healthy and isogenic hiPSC-CMs carrying causal HCM and DCM gene variants that are associated with arrhythmia in patients.

Conclusions: We conclude that deep learning algorithms can effectively evaluate proarrhythmic risk of small molecules. Moreover, they can also be used to discern heightened arrhythmic risk caused by genetic mutations that increase the propensity for drug-induced arrhythmia in patients.

Unfolded Protein Response as a Compensatory Mechanism and Potential Therapeutic Target in PLN R14del Cardiomyopathy

BACKGROUND

Phospholamban (PLN) is a critical regulator of calcium cycling and contractility in the heart. The loss of arginine at position 14 in PLN (R14del) is associated with dilated cardiomyopathy with a high prevalence of ventricular arrhythmias. How the R14 deletion causes dilated cardiomyopathy is poorly understood, and there are no disease-specific therapies.

METHODS

We used single-cell RNA sequencing to uncover PLN R14del disease mechanisms in human induced pluripotent stem cells (hiPSC-CMs). We used both 2-dimensional and 3-dimensional functional contractility assays to evaluate the impact of modulating disease-relevant pathways in PLN R14del hiPSC-CMs.

RESULTS

Modeling of the PLN R14del cardiomyopathy with isogenic pairs of hiPSC-CMs recapitulated the contractile deficit associated with the disease in vitro. Single-cell RNA sequencing revealed the induction of the unfolded protein response (UPR) pathway in PLN R14del compared with isogenic control hiPSC-CMs. The activation of UPR was also evident in the hearts from PLN R14del patients. Silencing of each of the 3 main UPR signaling branches (IRE1, ATF6, or PERK) by siRNA exacerbated the contractile dysfunction of PLN R14del hiPSC-CMs. We explored the therapeutic potential of activating the UPR with a small molecule activator, BiP (binding immunoglobulin protein) inducer X. PLN R14del hiPSC-CMs treated with BiP protein inducer X showed a dose-dependent amelioration of the contractility deficit in both 2-dimensional cultures and 3-dimensional engineered heart tissues without affecting calcium homeostasis.

CONCLUSIONS

Together, these findings suggest that the UPR exerts a protective effect in the setting of PLN R14del cardiomyopathy and that modulation of the UPR might be exploited therapeutically.

Cranial nerve involvement in typical and atypical chronic inflammatory demyelinating polyneuropathies

BACKGROUND AND PURPOSE

Cranial nerve palsy is occasionally present in patients with chronic inflammatory demyelinating polyneuropathy (CIDP), but its prevalence, characteristics and relations with the CIDP subtypes have rarely been investigated. The aim of this study was to systematically assess cranial nerve involvement in typical and atypical CIDP.

METHODS

Clinical data were reviewed in 132 consecutive patients with CIDP, including typical CIDP (n = 89), multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) (n = 31), distal acquired demyelinating symmetric (DADS) (n = 9) and others (n = 3).

RESULTS

The frequency of cranial nerve palsy was 11% in typical CIDP, 48% in MADSAM and 11% in DADS. Facial and bulbar palsy was most frequently present (9%), followed by ocular motor nerve palsy (5%). Bilateral involvement was seen in all typical CIDP and DADS patients, whereas 80% of MADSAM patients had unilateral palsy. The presence of cranial nerve involvement was associated with more severe limb muscle weakness in typical CIDP, but not in MADSAM. Cranial nerve palsy fully recovered in 90% of typical CIDP and in 67% of MADSAM patients.

CONCLUSION

Amongst the CIDP subtypes, cranial palsy is frequent and unilateral in MADSAM, and less frequent and bilateral in typical CIDP and DADS. In typical CIDP, facial and bulbar palsy reflects more severe and extensive inflammation.

Endogenous Retrovirus-Derived lncRNA BANCR Promotes Cardiomyocyte Migration in Humans and Non-human Primates

Transposable elements (TEs) comprise nearly half of the human genome and are often transcribed or exhibit cis-regulatory properties with unknown function in specific processes such as heart development. In the case of endogenous retroviruses (ERVs), a TE subclass, experimental interrogation is constrained as many are primate-specific or human-specific. Here, we use primate pluripotent stem-cell-derived cardiomyocytes that mimic fetal cardiomyocytes in vitro to discover hundreds of ERV transcripts from the primate-specific MER41 family, some of which are regulated by the cardiogenic transcription factor TBX5. The most significant of these are located within BANCR, a long non-coding RNA (lncRNA) exclusively expressed in primate fetal cardiomyocytes. Functional studies reveal that BANCR promotes cardiomyocyte migration in vitro and ventricular enlargement in vivo. We conclude that recently evolved TE loci such as BANCR may represent potent de novo developmental regulatory elements that can be interrogated with species-matching pluripotent stem cell models.

Pharmacological Silencing of MicroRNA-152 Prevents Pressure Overload-Induced Heart Failure

BACKGROUND

MicroRNAs are small, noncoding RNAs that play a key role in gene expression. Accumulating evidence suggests that aberrant microRNA expression contributes to the heart failure (HF) phenotype; however, the underlying molecular mechanisms are not well understood. A better understanding of the mechanisms of action of microRNAs could potentially lead to targeted therapies that could halt the progression or even reverse HF.

METHODS AND RESULTS

We found that microRNA-152 (miR-152) expression was upregulated in the failing human heart and experimental animal models of HF. Transgenic mice with cardiomyocyte-specific miR-152 overexpression developed systolic dysfunction (mean difference, -38.74% [95% CI, -45.73% to -31.74%]; P<0.001) and dilated cardiomyopathy. At the cellular level, miR-152 overexpression perturbed mitochondrial ultrastructure and dysregulated key genes involved in cardiomyocyte metabolism and inflammation. Mechanistically, we identified Glrx5 (glutaredoxin 5), a critical regulator of mitochondrial iron homeostasis and iron-sulfur cluster synthesis, as a direct miR-152 target. Finally, a proof-of-concept of the therapeutic efficacy of targeting miR-152 in vivo was obtained by utilizing a locked nucleic acid-based inhibitor of miR-152 (LNA 152) in a murine model of HF subjected to transverse aortic constriction. We demonstrated that animals treated with LNA-152 (n=10) showed preservation of systolic function when compared with locked nucleic acid-control treated animals (n=9; mean difference, 18.25% [95% CI, 25.10% to 11.39%]; P<0.001).

CONCLUSIONS

The upregulation of miR-152 expression in the failing myocardium contributes to HF pathophysiology. Preclinical evidence suggests that miR-152 inhibition preserves cardiac function in a model of pressure overload-induced HF. These findings offer new insights into the pathophysiology of HF and point to miR-152-Glrx5 axis as a potential novel therapeutic target.

Concise Review: Precision Matchmaking: Induced Pluripotent Stem Cells Meet Cardio-Oncology

As common chemotherapeutic agents are associated with an increased risk of acute and chronic cardiovascular complications, a new clinical discipline, cardio-oncology, has recently emerged. At the same time, the development of preclinical human stem cell-derived cardiovascular models holds promise as a more faithful platform to predict the cardiovascular toxicity of common cancer therapies and advance our understanding of the underlying mechanisms contributing to the cardiotoxicity. In this article, we review the recent advances in preclinical cancer-related cardiotoxicity testing, focusing on new technologies, such as human induced pluripotent stem cell-derived cardiomyocytes and tissue engineering. We further discuss some of the limitations of these technologies and present future directions. Stem Cells Translational Medicine 2019;8:758&767.

Effects of chelating agent and acids on Biodentine

BACKGROUND

To evaluate the effect of distilled water, ethylenediaminetetraacetic acid (EDTA), phosphoric acid and maleic acid on Biodentine regarding surface topography, microhardness and push-out bond strength (POBS).

METHODS

Fifty-two cylindrical shaped Biodentine specimens were divided into groups: control (distilled water); EDTA (17% EDTA); PA (37% phosphoric acid); and MA (7% maleic acid). Surfaces were evaluated by topographic analysis and Vickers microhardness test. Topographic changes were evaluated qualitatively and microhardness was statistically analyzed by Kruskal-Wallis test. Forty mandibular molars were used to simulate clinical conditions. The crowns were removed and a perforation was created at the furcal floor. The Biodentine was packed into the root perforations and the roots were divided into four groups (DW, EDTA, PA, MA). Samples were stored and subjected to interfacial analysis. POBS data were analyzed by Kruskal-Wallis and Dunn tests.

RESULTS

Ethylenediaminetetraacetic acid, MA and PA changed the morphology of the Biodentine surface. PA showed microhardness similar to distilled water (P > 0.05), while MA and EDTA demonstrated reduced values when compared with PA (P < 0.05). PA improved the POBS of Biodentine in comparison with the control.

CONCLUSIONS

Changes in the topography, microhardness and POBS of Biodentine are associated with irrigant agent used.

Comparação das peles de tilápia do nilo, pacu e tambaqui: histologia, composição e resistência

O objetivo deste trabalho foi comparar as peles de tilápia (Oreochromis niloticus), pacu (Piaractus mesopotamicus) e tambaqui (Co-lossoma macroporum) quanto à histologia, composição centesimal, características físico-química e físico-mecânica. Para tanto foram utilizados 10 kg de peles de cada espécie. Todas as peles seguiram a mesma metodologia de curtimento, sendo todas processadas em fulão. Foram realizadas análises histológicas e de composição nas peles in natura, e após o curtimento foram utilizados 20 couros de cada espécie para obtenção dos corpos-de-prova de cada tratamento para análises físico-química e físico-mecânica. A pele de tilápia do Nilo apresentou lamélulas maiores que as demais espécies analisadas, entretanto, a camada mais profunda da derme desta espécie apresenta feixes de fibras colágenas mais finas no sentido transversal a superfície da pele, enquanto nas peles de pacu e tambaqui observou-se fibras colágenas mais espessas no sentido longitudinal e grossos feixes de fibras colágenas no sentido transversal a superfície da pele. A pele de tilápia do Nilo apresentou maior teor de umidade (67,14 %), lipídeos (1,96 %) e cinzas (1,82 %), entretanto a pele dessa espécie foi a que apresentou menor teor de proteína bruta (29,08 %). Maior teor de proteína bruta foi encontrado nas peles de tambaquis (35,70 %). Os couros de tilápia do Nilo apresentaram menor espessura (0,68 mm), resistência à tração (11,86 N/mm2), rasgamento progressivo (40,18 N/mm), menor elasticidade (52,63 %) e menor força máxima (81,06 %) comparada aos couros de pacu e tambaqui. Sendo o couro de tambaqui, o de maior espessura (0,89 mm) e resistência para as variáveis analisadas (tração= 29,49 N/mm2, rasgamento progressivo= 80,01 N/mm e força máxima=224,25). Os couros de tilápia são menos resistentes que os de pacu e tambaqui; os couros de tambaqui, poderiam ser destinados à confecção de vestuários, e os couros das três espécies apresentam a espessura dentro do recomendado para confecção de luvas e vestimentas.

Influência do tempo do processo de curtimento na qualidade dos couros de coelhos (o. Cunniculus)

O experimento foi conduzido para avaliar a qualidade dos couros de coelhos em diferentes partes da superfície e orientações, submetidos a dois diferentes tempos de processamento. Foram utilizadas 40 peles de coelhos, da raça Nova Zelândia Branco, abatidos aos 70 dias de idade. Foi utilizado um delineamento inteiramente casualizado em esquema de parcelas subdivididas, tendo nas parcelas os tratamentos (T1= tempo normal; T2= tempo contínuo) e nas subparcelas as posições de corte no couro (P1= anterior longitudinal; P2 = anterior transversal; P3= posterior longitudinal e P4= posterior transversal), com dez repetições por tratamento. As etapas aplicadas no processo de curtimento foram: remolho, descarne, caleiro (3% de sulfeto de sódio e 4% de cal), desencalagem, purga, desengraxe, píquel, curtimento (6% de sais de cromo), neutralização, recurtimento (4% sais de cromo), tingimento, engraxe (6% de óleos sulfatados), secagem e amaciamento. A espessura dos couros foi maior (p

Acute physiological responses to different circuit training protocols

AIM

The purpose of present study was to compare the acute physiological responses to a circuit weight training with the responses to a combined circuit training (weight training and treadmill run).

METHODS

The sample consisted of 25 individuals at an average state of training, 10 men and 15 female, between 18 and 35 year old. There were selected 60 second sets of resistance exercises to the circuit weight training (CWT). Whereas in the combined circuit training (CCT), the subjects spent 30 seconds on the same resistance exercises and 30 seconds running on the treadmill. The rest intervals between the sets lasted 15 seconds. The analysis of variance (ANOVA) with 5% significance level was utilized to the statistical analysis of the results.

RESULTS

Comparing circuit training protocols, it was noted that CCT elicits a higher relative and absolute VO2 and energy expenditure values than CWT for both genders (P<0.05). Regarding inter-gender comparison, males showed higher absolute and relative VO2 and absolute energy expenditure values for both CWT and CCT than females (P<0.05). Females showed a significant greater %VO2max value for both CWT and CCT. Due to the experimental conditions used to state both circuit training bouts (CWT and CCT), the VO2 rate found was higher than the values reported by previous studies which used heavier weight lift.

CONCLUSION

CCT seems adequate to produce cardiovascular improvements and greater energy expenditure for both men and women, while CWT group classes are sufficient only for unfit women.

Addition of a short central extension to surface cemented tibial trays in primary TKA: an in vitro study of the effect on initial fixation stability and its relationship to supporting bone density

BACKGROUND

Short central extensions which do not enter the tibial medullary canal are incorporated to cemented tibial components to increase initial stability in primary total knee arthroplasty. Their role in tibiae of differing preoperative mechanical quality has been little studied.

METHODS

Twelve embalmed cadaveric tibiae were paired and divided into two groups, receiving a similar cemented tibial component with or without a non-cemented short central extension (10 mm diameter, 35 mm length). The specimens were subjected to 6000 cycles of a medially applied 1350 N load. Relative bone-tray displacements were measured and the evolution of inducible and permanent micromotions were computed. The apparent density of the cancellous bone under the tibial tray and at the area to support the extension was computed from computed tomography images of each specimen.

FINDINGS

No significant differences between groups were detected for any parameters. For the group with extension, a significant negative linear correlation (P = 0.009, r(2) = 0.849) was found between the inducible tilt of the tray and the bone density at the zone of the extension. Also a trend towards a negative linear relation (P = 0.07, r(2) = 0.59) was observed for the same group between maximum subsidence and apparent density at the zone of the extension.

INTERPRETATION

The study did not find that the addition of a non-cemented short central extension provides any overall improvement of the initial fixation stability. However, it was found that short extensions may enhance tilting stiffness of the bone-implant construct if bone of sufficient mechanical quality is located around its supporting area.

The influence of wire positioning upon the initial stability of scaphoid fractures fixed using Kirschner wires

A finite element model of the carpal scaphoid and its joints was developed to study how wire positioning affects the initial stability of the fixation of scaphoid waist fractures using Kirschner wires. A transverse fracture of the scaphoid waist was simulated along with its fixation using five different two-wire configurations. The resulting models were subjected to a load simulating a 200N force passing through the wrist. Friction between bony fragments was taken into account; as the friction coefficient of cancellous bone is unknown, three different values were analysed. For each of these friction coefficient values, the smallest transverse interfragmentary displacements, and consequently maximum initial stability, were obtained for the model that simulated the maximum gap between wires in the plane of fracture. Results also show that for a similar gap in the plane of fracture, more stable fixation can be achieved when wires cross each other not only in the frontal plane of the hand, but also perpendicularly to it.

Preliminary evaluation of a full-time falling monitor for the elderly

The article presents the early outcomes of the evaluation of an intelligent accelerometer unit (IAU) utilized for detecting the falling events of elderly people . The overall design of the monitor where the IAU is integrated is briefly exposed. The outcomes of a laboratory study carried out over 8 volunteers show that the device is able to distinguish true falling events from normal activities like fast walking or going up/downstairs. The influences of the subject and the environment have been taken into account profiting from the processing capacity of the monitor distributed architecture.

Non-conventional yeasts as hosts for heterologous protein production

Yeasts are an attractive group of lower eukaryotic microorganisms, some of which are used in several industrial processes that include brewing, baking and the production of a variety of biochemical compounds. More recently, yeasts have been developed as host organisms for the production of foreign (heterologous) proteins. Saccharomyces cerevisiae has usually been the yeast of choice, but an increasing number of alternative non-Saccharomyces yeasts has now become accessible for modern molecular genetics techniques. Some of them exhibit certain favourable traits such as high-level secretion or very strong and tightly regulated promoters, offering significant advantages over traditional bakers' yeast. In the present work, the current status of Kluyveromyces lactis, Yarrowia lipolytica, Hansenula polymorpha and Pichia pastoris (the best-known alternative yeast systems) is reviewed. The advantages and limitations of these systems are discussed in relation to S. cerevisiae.

[Epidemiological surveillance of trachoma in a school in a city of southeast Brazil]

INTRODUCTION

Epidemiological surveillance activities undertaken after the detection of an active trachoma case in the APAE-SP are described.

MATERIAL AND METHOD

A total of 1,009 pupils, employees and household contacts had an eye examination. Treatment control was carried out at the institution 4 times at 45 day-intervals.

RESULTS

The overall prevalence was of 5.9%, 5.1% being of follicular trachoma (TF), 0.3% of intense trachoma (TF/TI) and 0.5% of cicatricial trachoma (TS). At the first control exercise 45.5% of the trachoma cases had no signs of the disease and 40.0% underwent treatment. At the last control exercise 20% were found to have been cured with no vestigial scars. Non-attendance was of 38.2%. The distribution of secondary cases showed great dispersion, suggesting dissemination throughout Greater S. Paulo.

DISCUSSION AND CONCLUSIONS

The trachoma control activities do not show satisfactory results, perhaps due to the prolonged duration of the treatment and follow-up. The development of strategies of clinical intervention should be implemented for better control of the disease.

Cloning and sequencing of the URA5 gene from the yeast Yarrowia lipolytica

The URA5 gene of Yarrowia lipolytica encoding the orotate phosphoribosyl transferase (OPRTase, EC2.4.2.10) was isolated by target integration in a mutant strain originally named ura2.21. The nucleotide sequence of the gene predicts a protein with high similarities with the OPRTases from Saccharomyces cerevisiae, Podospora anserina and Escherichia coli and to a lesser extent with that of Dictyostelium discoideum. The transcription start point has been mapped by primer extension analysis and indicates the existence of a long leader sequence in the corresponding mRNA. Northern-blot hybridization revealed the URA5 transcript to be approximately 0.94 kb. Deletion of the URA5 gene in Y. lipolytica produced a leaky phenotype similar to the one described for the ura5 mutation in S. cerevisiae. The URA5 gene of Y. lipolytica was able to complement functionally the ura5 mutation of S. cerevisiae.

D-myo-inositol 1,2,6-trisphosphate blocks neuropeptide Y-induced facilitation of noradrenaline-evoked vasoconstriction of the mesenteric bed

Perfusion of the rat mesenteric bed with 0.1 or 10 nM neuropeptide Y potentiated the noradrenaline-induced increase in mesenteric pressure; the peptide did not modify basal perfusion pressure. While perfusion with 0.1 nM neuropeptide Y significantly increased the maximal noradrenaline-evoked vasoconstriction without modifying its EC50, 10 nM neuropeptide Y potentiated the maximal noradrenaline effect and significantly shifted its concentration-response curve to the left. Perfusion with 1-10 microM D-myo-inositol 1,2,6-trisphosphate (alpha-trinositol) reduced, in a concentration-dependent fashion, the neuropeptide Y-induced potentiation of the noradrenaline-evoked vasoconstriction without altering the potency or maximal response evoked by the catecholamine alone. Perfusion with 0.1 nM neuropeptide Y plus 1 microM alpha-trinositol completely abolished the neuropeptide Y-induced facilitation of the noradrenaline effect. alpha-Trinositol 1 microM in the presence of 10 nM neuropeptide Y caused a nonparallel rightward shift of the noradrenaline concentration-response curve as compared to that obtained in the presence of 10 nM neuropeptide Y alone. The alpha-trinositol blockade of the facilitatory action of neuropeptide Y was reversible.