Question-based review for pharmaceutical development: An enhanced quality approach

Over the last years, the pharmaceutical industry has faced real challenges regarding quality assurance. In this context, the establishment of more holistic approaches to the pharmaceutical development has been encouraged. The emergence of the Quality by Design (QbD) paradigm as systematic, scientific and risk-based methodology introduced a new concept of pharmaceutical quality. In essence, QbD can be interpreted as a strategy to maximize time and cost savings. An in-depth understanding of the formulation and manufacturing process is demanded to optimize the safety, efficacy and quality of a drug product at all stages of development. This innovative approach streamlines the pharmaceutical Research and Development (R&D) process, provides greater manufacturing flexibility and reduces regulatory burden. To assist in QbD implementation, International Conference on Harmonisation (ICH), U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) organized and launched QbD principles in their guidance for industry, identifying key concepts and tools to design and develop a high-quality drug product. Despite the undeniable advantages of the QbD approach, and the widespread information on QbD regulatory expectations, its full implementation in the pharmaceutical field is still limited. The present review aims to establish a crosswise overview on the current application status of QbD within the framework of the ICH guidelines (ICH Q8(R2) - Q14 and ICH Q2(R2)). Moreover, it outlines the way information gathered from the QbD methodology is being harmonized in Marketing Authorization Applications (MAAs) for European market approval. This work also highlights the challenges that hinder the deployment of the QbD strategy as a standard practice.

A quality by design framework for developing nanocrystal bioenabling formulations

The present study aims to outline a rational framework for the design and development of a 1.0% (w/v) hydrocortisone nanocrystal-based formulation, resorting to a simple, efficient, and scalable nanonization methodology, based on the high-pressure homogenization (HPH) technique. Accordingly, the innovative product was comprehensively optimized following a Quality by Design (QbD) approach. The thorough selection of formulation composition was driven by a dual purpose: improving skin permeation and stability. In the early stage of development, a Failure Mode, Effects and Criticality Analysis (FMECA) diagram was employed to identify the most impactful variables for the critical quality attributes (CQAs). In this sense, a rotatable, three-factor and five-level circumscribed central composite design (CCCD) was applied to investigate how squalene concentration (x1), soluplus concentration (x2) and HPH-time (x3) influence physicochemical properties, performance and physical stability of the formulation. A robust Design Space (DS) was defined, establishing the optimal settings for the critical variables, whose combination meets the requirements set in the quality target product profile (QTPP). Morphological analysis revealed the cuboidal shape of hydrocortisone nanocrystals. In what concerns colloidal properties, the most promising formulation disclosed a small particle size (Dx(50) = 311.8 ± 1.5 nm), along with narrow size distribution (span value = 1.91 ± 0.17). Zeta potential results (-2.19 ± 0.15 mV--12.1 ± 0.4 mV) suggested a steric hindrance stabilization. FTIR spectra showed no chemical interactions between drug and formulation components. XRD diffractograms confirmed loss of crystallinity during the downsizing process. In vitro studies revealed an improvement on drug release rate (316 ± 21-516 ± 35 μg/cm2/√t), compared to the coarse suspension and commercial products, and a straight dependence on the stabilizer concentration and HPH time. The permeation flux across the skin (0.16 ± 0.02-1.2 ± 0.5 μg/cm2/h) appeared to be dependent on the drug physicochemical properties, in particular saturation solubility. Further characterization of the experimental formulations pointed out the role of the stabilizing component to prevent against physical instability phenomena. This organic solvent-free, and therefore "green" nanocrystal production technology offers great potential for pharmaceutical R&D and drug delivery by enabling the development of new forms of conventional drugs with optimal physicochemical properties and performance.

Cartoon diplomacy: visual strategies, imperial rivalries and the 1890 British Ultimatum to Portugal

This paper offers a novel interpretation of the 1890 British Ultimatum, by bringing to the front of the stage its techno-diplomatic dimension, often invisible in the canonical diplomatic and military narratives. Furthermore, we use an unconventional historical source to grasp the British-Portuguese imperial conflict over the African hinterland via the building of railways: the cartoons of the politically committed and polyvalent Portuguese artist and journalist Rafael Bordalo Pinheiro (1846-1905), published in his journal Ponto nos iis, from the end of 1889 and throughout 1890. We argue that the Ponto nos iis cartoons played a so far overlooked role in the unfolding of British-Portuguese affairs, as they shaped at a distance a diplomatic exchange with the British satirical journal Punch. Attacking and counterattacking his fellow cartoonists in Britain, Pinheiro surged into the role of informal diplomat. This cartoon visual and public diplomacy unfolded in the pages of both journals and was tied to the two countries' colonial conquests in Africa, where the Portuguese and British empires were competing to dominate the African hinterland through large technological systems. Hence the cartoons made visible to wider audiences the otherwise hidden role that technologies played in the two countries' affairs. In turn, the cartoons aimed at persuading the Portuguese public and ruling classes alike that only regime change, from monarchic to republican, would restore the wounded Portuguese national pride.

Designing a Nurse-Led Program for Self-Management of Substance Addiction Consequences: A Modified e-Delphi Study

Therapeutic interventions for people with problematic use of psychoactive substances can help tackle specific needs related to substance addiction consequences. This modified e-Delphi study aimed to establish consensus on a training program for self-management of substance addiction consequences. The study was conducted between February and April 2022, with an experts' sample of 28 participants in the first round and 24 in the second. A priori consensus criteria were defined for each round. The results revealed a very strong consensus was achieved on the structure of the program and on clinical areas, such as the problematic use of substances, general health knowledge, health-seeking behavior and adherence, self-knowledge and well-being, social role and personal dignity, and family process. Additionally, over 80% participant consensus was achieved on an extensive number of interventions categorized as psychoeducational, psychotherapeutic, socio therapeutic, brief interventions, social skills training, problem solving techniques, relaxation techniques, and counseling. These findings may be able to fulfill a gap concerning structured treatment approaches for people with problematic use of psychoactive substances. Supporting self-management of the consequences of substance addiction and its application can change nurses' interventions.

Structured programs for the self-management of substance addiction consequences in outpatient services: A scoping review

Structured intervention programs are an important resource for supporting people with substance addiction. Although evidence suggests that they improve health outcomes, such as specific symptoms, less is known about their impact on patients’ ability to self-manage the consequences of substance addiction. The aim of this review is to scope outpatient intervention programs focused on the self-management of substance addiction consequences. Approach. This review followed the Joanna Briggs Institute (JBI) methodology for scoping reviews. MEDLINE and CINAHL (through Ebsco), Psychology & Behavioral Sciences Collection (including PsycINFO) and Web of Science were screened to identify articles published in the last 10 years. Only primary research was included. Out of 891 records, 19 were eligible for this review—12 randomized controlled trials (RCT), 6 quasi-experimental study and 1 observational study. Those studies reported group interventions (10), individual interventions (8) and 1 mixed approach. The most common interventions were based on motivational strategies, relapse prevention and definition of active plans for risky situations. 10 studies reported positive effects. The identification of structured programs may support the development of new approaches focused on empowerment and quality of life of people with substance addiction. Programs to empower patients for self-management of substance addiction consequences are often complex and rely on health professionals’ commitment. Nevertheless, they are a feasible approach that seems to benefit patients managing chronic conditions associated with substance addiction.

Gastronomic Experience and Consumer Behavior: Analyzing the Influence on Destination Image

Gastronomy experiences are becoming a fundamental factor that influences the making of a decision regarding choosing a travel destination, as well as being a crucial factor in shaping tourists' satisfaction regarding their overall travel experience. The aim of the study is to identify and explain the simultaneous impact of the key factors that influence a gastronomic experience and their impact on tourists' satisfaction with a trip and the destination's brand. These issues were addressed within the context of Ukraine, as this is an overlooked area of academic research, and an online survey was conducted, targeting domestic and international tourists. Structural equation modeling was used to assess and reveal the proposed hypotheses in the model. The study contributed to the theoretical understanding of the key factors that increases the occurrence of a memorable gastronomic experience and the relationship between the experience of food and its role in the satisfaction of and the perceived brand of a destination. Moreover, the finding showed that past experience and prior knowledge have a positive influence on the gastronomy experience, while tourists' prior knowledge effects the perceived quality of a destination's cuisine, as well as the food activities in the destination. Linkages in the model were empirically supported by statistical analyses. Nonetheless, the various level of the tourists' involvement with gastronomy might be used as an input to examine and improve the memorable gastronomic experience on-site. The research simultaneously highlighted the importance of gastronomy to tourist destinations for positioning on international and domestic markets. The paper not only provides theoretical but also practical implications. The hospitality and tourism businesses benefit from acknowledging the importance of local food and the local food market. The findings of this study are also deemed to assist destination marketers who observe that tourists have become more demanding in search of unique experiences offered by destinations.

In the Shadow of the 1919 Total Solar Eclipse: The Two British Expeditions and the Politics of Invisibility

This paper addresses the legendary total solar eclipse of 29 May 1919. Two British teams confirmed the light bending prediction by Albert Einstein: Charles R. Davidson and Andrew C. C. Crommelin in Sobral, Brazil and Arthur S. Eddington and Edwin T. Cottingham on the African island of Príncipe, then part of the Portuguese empire. By jointly analyzing the two astronomical expeditions supported by written and visual sources, I show how, despite extensive scholarship on this famous historical episode and the historiographical emphasis on the plural dimensions of knowledge construction, many human and non-human actors have been kept in the shadow of the eclipse. I do so by focusing on what I call knowledge from the periphery together with knowledge from below, grounded literally on how localities (sites) affect choices and events, and growing outward to encompass a wide range of participants. I show how the geopolitical status of the two nations where the observational sites were located, and specifically Portugal's condition of colonial power, affected main decisions and events, while highlighting the active role of participants, ranging from experts from the peripheries and those involved in the travels to local elites and anonymous peoples, some of whom contributed to the observation of totality.

Programa de suporte medicamentoso com pessoas dependentes de substâncias: Satisfação com os cuidados de enfermagem

Contexto: Na saúde, a satisfação com os cuidados recebidos é um indicador relevante para a qualidade e é fundamental para a adesão terapêutica dos utentes. Objetivos: Caraterizar a satisfação com os cuidados de enfermagem numa população atendida por enfermeiros num programa de suporte medicamentoso para pessoas dependentes de substâncias. Métodos: Estudo quantitativo, observacional de corte transversal. Amostra de conveniência acedida em janeiro 2019. Elaborou-se um questionário para caraterização sociodemográfica e psicossocial, e utilizada a “Escala da satisfação dos utentes com os cuidados de enfermagem no centro de saúde”, com 22 itens [resposta entre 0-66], que avaliam a satisfação em 6 dimensões (Qualidade na assistência; Envolvimento do utente; Formalização da informação; Promoção de elo de ligação; Informação de recursos; Individualização da informação). Obteve-se o parecer positivo de uma comissão de ética. Resultados: Participaram 181 (n) pessoas. Obteve-se um Alpha de Cronbach da escala, de 0,892. A média apurada foi 59,36 dp=8,19 [23-66]. A subescala que revelou maior índice de satisfação foi “Individualização da informação” (itens relacionados com explicação da informação, de forma compreensível, por parte dos enfermeiros, assim como garantir que o utente percebeu a informação). Com menor índice de satisfação “Informação de recursos” (preocupação em envolver os familiares, informação sobre utilização de outros recursos disponíveis ou serviços de saúde). Conclusões: A satisfação é elevada, sendo a maior dificuldade apontada à inclusão de outros agentes no processo de acompanhamento e a informação de outros recursos disponíveis. Os resultados mantêm aberta a discussão sobre a melhor forma de fazer investigação sobre satisfação.

Rheology by Design: A Regulatory Tutorial for Analytical Method Validation

The increasing demand for product and process understanding as an active pursuit in the quality guideline Q8 and, more recently, on the draft guideline on quality and equivalence of topical products, has unveiled the tremendous potential of rheology methods as a tool for microstructure characterization of topical semisolid dosage forms. Accordingly, procedure standardization is a dire need. This work aimed at developing and validating a methodology tutorial for rheology analysis. A 1% hydrocortisone cream was used as model cream formulation. Through a risk assessment analysis, the impact of selected critical method variables (geometry, temperature and application mode) was estimated in a broad range of rheological critical analytical attributes-zero-shear viscosity, upper-shear thinning viscosity, lower-shear thinning viscosity, infinite-shear viscosity, rotational yield point, thixotropic relative area, linear viscoelastic region, oscillatory yield point, storage modulus, loss modulus, and loss tangent. The proposed validation of the approach included the rheometer qualification, followed by the validation of numerous operational critical parameters regarding a rheology profile acquisition. The thixotropic relative area, oscillatory yield point, flow point and viscosity related endpoints proved to be highly sensitive and discriminatory parameters. This rationale provided a standard framework for the development of a reliable and robust rheology profile acquisition.

[Urinary Tract Infections Caused by Community-Acquired Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in a Level III Hospital - A Retrospective Study]

INTRODUCTION

The emergence of β-lactamases producing bacteria is a problem worldwide, with increasing importance in communityacquired infections, especially in urinary tract infections. Data regarding the use of non-carbapenem antimicrobials in these infections are scarce. The aim of this study was to analyse the treatment and outcome of urinary tract infections caused by community-acquired β-lactamase-producing bacteria in children.

MATERIAL AND METHODS

Retrospective study performed in a level III paediatric hospital, between June 2007 and December 2017. All children with β-lactamase-producing Enterobacteriaceae identified in aseptically collected urine culture were included.

RESULTS

A total of 175 urinary infections caused by β-lactamases producing bacteria were diagnosed, 34 (19%) were community-acquired: 25 Escherichia coli (74%), 4 Klebsiella pneumoniae (12%), 4 Proteus mirabilis (12%) and 1 Proteus vulgaris (3%). In 30 (88%) cases, it was the first urinary infection. After identification of the microorganism and antimicrobial susceptibility, 33 (97%) children were re-evaluated and 24 (71%) had a repeat urine culture, which was positive in three (13%). In six (18%) cases, antibiotic treatment was modified. Four (12%) children had another UTI in the following month. In 30 (88%) children, imaging was carried out, with no nephrourological malformations detected.

DISCUSSION

In the last decade, about 20% of urinary infections caused by β-lactamase-producing Enterobacteriaceae were community-acquired with a relatively stable number of cases over the years. No nephro-urological malformations were identified in these children.

CONCLUSION

Although the number of cases is small, the clinical and microbiological outcomes showed that most were successfully treated with non-carbapenem antibiotics, with low recurrence of new episodes of urinary tract infections.

The multidimensionality of suicide risk factors and criteria in a nonclinical population: Replication across two countries and two languages

Across two countries and two languages, this research examined the multidimensional associations between suicidality (e.g., past ideation/attempts, communication of intent) and empirically important psychological risk factors (e.g., mental pain, perceived burdensomeness, thwarted belongingness). For samples of 228 Canadian and 331 Portuguese university undergraduates, four dimensions emerged in each sample with two of these, intrapersonal and interpersonal, demonstrating strong replicability across countries and languages. It was concluded that suicidality is a phenomenon that demonstrates some multidimensional similarities across cultures.

Developing Cream Formulations: Renewed Interest in an Old Problem

This work aimed at establishing a framework to screen and understand the product variability deeming from factors that affect the quality features of cream formulations. As per Quality by Design - based approach, cream quality target profile and critical quality attributes were identified, and a risk assessment analysis was conducted to qualitatively detect the most critical variables for cream design and development. A Plackett-Burman design was used to screen out unimportant factors, avoiding collecting large amounts of data. Accordingly, 2 designs of experiments (DoE-1 and DoE-2) were performed, and the effects of independent variables on the cream formulations responses were estimated. At different factor combinations, significant variability was observed in droplet size, consistency, hardness, compressibility, and adhesiveness with values ranging from 2.6 ± 0.9 to 10 ± 6 μm, 7.93 ± 0.05 to 13.53 ± 0.14 mm, 27.6 ± 0.3 to 58.4 ± 1.1 g, 38 ± 6 to 447 ± 37 g.s, and 25.7 ± 2.1 to 286 ± 33 g.s, respectively. The statistical analysis allowed determining the most influent factors. This study revealed the potential of Quality by Design methodology in understanding product variability, recognizing the most critical independent variables for the final product quality. This systematic approach in the pharmaceutical field will yield more robust products and processes, provisioning time and cost effective developments.

Psychological pain and suicidal ideation in undergraduates: The role of pain avoidance

In the present study, the first with a Western sample, we tested the relationship between three dimensions of psychological pain and suicidal ideation in a sample of 331 Portuguese college students. When controlling for the effect of depressive symptoms, the avoidance dimension, but not the cognitive and affective dimensions of psychological pain, made a significant contribution in predicting the three indicators of suicidal ideation. According to these results, psychotherapeutic action may focus either on enabling clients to tolerate mental pain or on providing more effective and adaptive strategies to cope with this pain.

A Tutorial for Developing a Topical Cream Formulation Based on the Quality by Design Approach

The pharmaceutical industry has entered in a new era, as there is a growing interest in increasing the quality standards of dosage forms, through the implementation of more structured development and manufacturing approaches. For many decades, the manufacturing of drug products was controlled by a regulatory framework to guarantee the quality of the final product through a fixed process and exhaustive testing. Limitations related to the Quality by Test system have been widely acknowledged. The emergence of Quality by Design (QbD) as a systematic and risk-based approach introduced a new quality concept based on a good understanding of how raw materials and process parameters influence the final quality profile. Although the QbD system has been recognized as a revolutionary approach to product development and manufacturing, its full implementation in the pharmaceutical field is still limited. This is particularly evident in the case of semisolid complex formulation development. The present review aims at establishing a practical QbD framework to describe all stages comprised in the pharmaceutical development of a conventional cream in a comprehensible manner.

Hospital centre performance dimensions and internal stakeholder valuation: a case study

Purpose

Hospital centres (HCs) are the result of a horizontal integration of two or more hospital units. The benefits of this integration have been presented in the literature. The purpose of this paper is to define the hospital performance dimensions most valued by HC internal stakeholders, and to evaluate if the importance given to each dimension is different when comparing professional groups.

Design/methodology/approach

An in-depth HC case study using a quantitative survey based on the Parsons’ social system action theory to achieve this goal was conducted which embraces the four major models of organizational performance. In the final version of the survey, 37 items were retained for analysis. An exploratory factor analysis was conducted for a final sample of 365 participants, through principal component analysis, with oblique rotation and the Kaiser criterion.

Findings

Four factors were retained: “Human resources development and Internal Processes”, “Attractiveness/Openness”, “Public service mission” and “Interpersonal relationships”. The means factor scores only reveal statistical differences between the attractiveness/openness factor and the remaining three factors. A shared view was found in this study among the three groups of internal stakeholders: physicians, caregivers and administrative staff.

Originality/value

The results of this study suggest that the HC performance concept should be expanded and performance measurement frameworks with a greater scope should be used. Interpersonal relationships, the human resources development and the public service are considered important dimensions for the performance measurement of the HC. Additionally, a consensual view regarding the most valued performance dimension could contribute to a beneficial and healthy working environment and improvements in HC performance.

Horticulture in Portugal 1850-1900: The role of science and public utility in shaping knowledge

In this paper, we address the emergence of horticultural practice, agents, spaces and institutions in the two urban settings of Lisbon and Porto, in Portugal, during the second half of the nineteenth century. We do so by following the networking activities of two players: the self-made horticulturist and entrepreneur José Marques Loureiro, who created, in Porto, a commercial horticultural establishment and founded the Journal of Practical Horticulture; and the agronomist Francisco Simões Margiochi, head of the gardens and green grounds department of the municipality, who created the first course on gardening and horticulture, and founded the Royal Horticultural Society, both in Lisbon. Their joint activities were aimed at establishing horticulture as an applied science and to cater simultaneously to an extended audience of citizens. They enable us to enrich the narratives on the emergence and development of horticulture in Europe by calling attention to the participation in circulatory extended networks of actors who are often absent from these accounts. Additionally, they allow a comparative assessment of the outcome of their actions at the national level, and to understand their results in terms consonant with recent historiographical trends on the co-construction of centres and peripheries.

ABBREVIATIONS

AML - Arquivo Municipal de Lisboa (Municipal Archive of Lisbon).; ANTT - Arquivo Nacional da Torre do Tombo (National Archives at Torre do Tombo).; AHCPL - Arquivo Histórico da Casa Pia de Lisboa (Historical Archive of the Casa Pia of Lisbon).; JHP - Jornal de Horticultura Practica (Journal of Practical Horticulture). Online at: http://www.fc.up.pt/fa/?p=nav&f=html.fbib-Periodico-oa&item=378 ; BSNHP - Boletim da Sociedade Nacional de Horticultura de Portugal (Bulletin of the National Society of Horticulture of Portugal).

Influence of bethanechol on salivary parameters in irradiated patients

BACKGROUND

Some studies have shown evidence that the prophylactic use of bethanechol chloride (BC) may be useful in preventing the incidence and/or severity of xerostomia (XT). However, the indication of BC in irradiated patients with XT needs to be better characterized. The study aimed to evaluate the influence of BC on XT, salivary flow rate, and salivary composition in patients previously submitted to head and neck radiotherapy.

MATERIAL AND METHODS

Forty five irradiated patients complaining of XT used 50 mg/day of BC for 3 months, and the salivary parameters were evaluated in 4 Phases (Before BC therapy, after one month of BC, 2 months of BC, and 3 months of BC). Biochemical analysis included buffering capacity; pH; total protein concentration (TP); amylase concentration (AM); catalase (CAT) and peroxidase (PX) activities. In addition, unstimulated and stimulated salivary flow rates were determined and XT was classified.

RESULTS

According to the XT grading system used, patients showed improvement in XT between Phase 1, and Phases 2, 3 and 4. In addition, some changes were observed in TP concentration (decreased); AM concentration (increased); and PX and CAT activities (decreased and increased, respectively) after Phase 2, for stimulated saliva collection (p<0.05).

CONCLUSIONS

Our results suggested that when BC was used to treat salivary gland dysfunction induced by head and neck radiotherapy, improvement in XT symptoms, and some changes in saliva composition were shown.

Lithium Induces Glycogen Accumulation in Salivary Glands of the Rat

Lithium is administered for the treatment of mood and bipolar disorder. The aim of this study was to verify whether treatment with different concentrations of lithium may affect the glycogen metabolism in the salivary glands of the rats when compared with the liver. Mobilization of glycogen in salivary glands is important for the process of secretion. Two sets of experiments were carried out, that is, in the first, the rats received drinking water supplemented with LiCl (38,25 and 12 mM of LiCl for 15 days) and the second experiment was carried out by intraperitoneal injection of LiCl solution (12 mg/kg and 45 mg LiCl/kg body weight) for 3 days. The active form of glycogen phosphorylase was not affected by treatment with LiCl considering the two experiments. The active form of glycogen synthase presented higher activity in the submandibular glands of rats treated with 25 and 38 mM LiCl and in the liver, with 25 mM LiCl. Glycogen level was higher than that of control in the submandibular glands of rats receiving 38 and 12 mM LiCl, in the parotid of rats receiving 25 and 38 mM, and in the liver of rats receiving 12 mM LiCl. The absolute value of glycogen for the submandibular treated with 25 mM LiCl, and the liver treated with 38 mM LiCl, was higher than the control value, although not statistically significant for these tissues. No statistically significant difference was found in the submandibular and parotid salivary glands for protein concentration when comparing experimental and control groups. We concluded that LiCl administered to rats influences the metabolism of glycogen in salivary glands.

STEP Matters: Historiographical Considerations

In this introduction, we revisit major discussions around historical themes and historiographical issues that took place during the fifteen-year life of STEP (Science and Technology at the European Periphery). We will attempt to draw the profile of STEP, and put forth some concrete proposals as to its prospects of collaboration with other groups and societies. We also elaborate on the rationale behind the selection of topics presented in this issue, analyse questions posed and challenges faced, and offer some historiographical comments on the potential of the STEP perspective in the context of international scholarship.

Ion release and mechanical properties of calcium silicate and calcium hydroxide materials used for pulp capping

AIM

To compare the ion release and mechanical properties of a calcium hydroxide (Dycal) and two calcium silicate (MTA Angelus and Biodentine) cements.

METHODOLOGY

Calcium and hydroxyl ion release in water from 24-h set cements were calculated from titration with HCl (n = 3). Calcium release after 7, 14, 21 and 28 days at pH 5.5 and 7.0 was measured using ICP-OES (n = 6). Flexural strength (FS) and modulus (E) were tested after 48-h storage, and compressive strength (CS) was tested after 48 h and 7 days (n = 10). Ion release and mechanical data were subjected to anova/Tukey and Kruskal-Wallis/Mann-Whitney tests, respectively (α = 0.05).

RESULTS

Titration curves revealed that Dycal released significantly fewer ions in solution than calcium silicates (P < 0.001). Calcium release remained constant at pH 7.0, whilst at pH 5.5, it dropped significantly by 24% after 21 days (P < 0.05). At pH 5.5, MTA Angelus released significantly more calcium than Dycal (P < 0.01), whilst Biodentine had superior ion release than Dycal at pH 7.0 (P < 0.01). Biodentine had superior flexural strength, flexural modulus and compressive strength than the other cements, whilst MTA Angelus had higher modulus than Dycal (P < 0.001).

CONCLUSIONS

Immediate calcium and hydroxyl ion release in solution was significantly lower for Dycal. In general, all materials released constant calcium levels over 28 days, but release from Dycal was significantly lower than Biodentine and MTA Angelus depending on pH conditions. Biodentine had substantially higher strength and modulus than MTA Angelus and Dycal, both of which demonstrated low stress-bearing capabilities.

Effect of Rheedia longifolia leaf extract and fractions on the P2X₇ receptor in vitro: novel antagonists?

Recently, the P2X(7) receptor has been reported to be associated with chronic inflammatory and neuropathic pain. Because Rheedia longifolia extract has analgesic and anti-inflammatory activity, we evaluated the in vitro inhibitory potential of methanol extract and fractions from its leaves on the P2X(7) purinergic receptor. The activity of P2X(7) was studied with a dye uptake assay and with the whole-cell patch clamp technique in mouse peritoneal macrophages treated with methanol extract of R. longifolia leaves and fractions. The dye uptake was evaluated by flow cytometry and fluorescence microscopy. The R. longifolia extract and some fractions showed an inhibitory effect on the P2X(7) purinergic receptor in a dose-dependent manner. The ethyl acetate fraction exhibited the most potent inhibitory effects. The methanol extract and the butanol fraction showed the same inhibitory effects, despite their lower potency compared with the other fractions. The R. longifolia extract and some of its fractions may be anti-inflammatory because of their inhibitory effect on the P2X(7) receptor. Further investigation is needed to determine the pattern of inhibition and selectivity. Chromatographic analysis indicated the presence of bisflavonoids in the methanol extract fractions. A member of this chemical family is the most probable active compound responsible for the P2X(7) inhibitory effects present in the R. Longifolia extract and fractions.

Perspectives on contemporary history of science in Portugal

The task of writing about historiography of science in a European periphery such as Portugal is particularly difficult due to the unavailability of a systematic inventory of sources for the history of science. In this paper we select a group of 20th-century sources, having in view the extended timeline available to the sorts of questions which can be posed to the historical material. We opted to analyze representative probes for four different categories of sources: a journal (1937-1951); the proceedings of a congress organized in the context of a commemorative event (1940); the works of two historians of science (1950s onward); and finally commemorative volumes celebrating the anniversary of the Academy of Sciences of Lisbon (1986, 1992). Besides briefly describing authors' profiles, professional backgrounds, historical periods and scientific areas covered, we discuss the type of historical account produced. We conclude with a brief overview of the state of the discipline in the past fifteen years bearing in mind historiographical orientations.

In between worlds: G.N. Lewis, the shared pair bond and its multifarious contexts

In this paper, I will look at the rather convoluted discovery process which gave birth to the concept of the shared electron pair bond as developed by G.N. Lewis, to be subsequently appropriated by the American founders of quantum chemistry, and highlight the complex relations between conceptual development and the different contexts in which ideas are created and presented. I will show how the successive installments of Lewis's model of the chemical bond were supported by and gained credence from an epistemological background in which Lewis explored the relations of chemistry to physics. Furthermore, they were shaped by the changing public contexts in which the successive metamorphoses of the ideas took place and their epistemological background was outlined and explored. The complexities which are always associated with a discovery process can therefore be illuminated if one pays attention to different interactive realms-the conceptual, epistemological, and the presentational one.

Pneumonia eosinofílica aguda com evolução para síndroma de dificuldade respiratória aguda: caso clínico

The Authors present a case of acute eosinophilic pneumonia (AEP) associated with severe acute respiratory distress syndrome in a previously healthy young adult, medicated with nitrofurantoin. AEP must be included in the differential diagnosis of community adquired pneumonia, as well as a cause of acute respiratory distress syndrome; its diagnosis is suggested by the presence of eosinophilic alveolitis in bronchoalveolar lavage fluid. The early diagnosis of AEP and corticosteroid therapy may be lifesaving.

Efeitos do carprofeno no ganho de força tênsil muscular e cutânea em ratas (Rattus norvegicus) submetidas à Laparorrafia mediana

O artigo não apresenta resumo.

Emprego de n-butil-cianoacrilato associado ou não à sutura na síntese de gastrotomias em ratos (Rattus norvegicus)

O artigo não apresenta resumo.

[Drowning: tematic review and casuistic analysis in the Intensive Care Medicine Service of University Hospital of Coimbra (1989-2002)]

Drowning is a major cause of accidental deaths, especially in childrens. In this review (part one) the definition, epidemiology, pathophysiology and treatments (with an enphasis on the ressuscitation) are discussed. From 1989 to 2002 part two) we recorded the clinical course of the 19 patients vitims of submersion admited to our ICU. We conclued that the majority of patients are young (mean = 37,3 years), mortality is high (26%), but the complete recovery is possible (63%). The cardio-respiratory arrest or Glasgow Coma Scale < or = 5 were related with poor prognosis, only with 3 survivors (1 without sequels). Trauma associated lesions were observed only in one patient.